Request for Declaratory Ruling on the Use of Digital Modulation by Multipoint Distribution Service and Instructional Television Fixed Service Stations
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FCC Declaratory Rulings › Request for Declaratory Ruling on the Use of Digital Modulation by Multipoint Distribution Service and Instructional Television Fixed Service Stations
Text
Federal Communications Commission FCC 96-304
Before the
Federal Communications Commission
Washington, D.C. 20554
In the Matter of . )
) Request For Declaratory Ruling on the Use ) DA 95-1854
of Digital Modulation by Multipoint )
Distribution Service and Instructional )
Television Fixed Service Stations )
DECLARATORY RULING AND ORDER
Adopted: July 9, 1996 Released: July 10,1996
By the Commission:
Table of Contents
Paragraph
I. INTRODUCTION ......................................... 1
II. BACKGROUND .......................................... 3
III. DISCUSSION ............................................ 9
A. Commission Rules and Cases in Support of Authorization
of Digital Modulation ................................. 9
B. Modulation Methods ................................. 13
C. Interference Considerations ............................. 16
1. Test Procedures ................................ 17
2. Interference Protection Ratios and Out-of-Band
Emissions Limitations ........................... 20
3. Digital Power and Related Considerations .............. 26
4. Frequency Tolerance and Use of Frequency Offset Techniques 31
5. Responsibility and Procedures for Alleviating
Potential and Actual Interference .................... 33
D. Application of Other MDS and ITFS Technical Rules
in a Digital Environment .............................. 38
1. Equipment Approval ............................ 39
2. Emission Designators ............................ 42
3. Transmission Standards .......................... 44
4. Equipment Standards, Modulation Limits and
Aural Power Limitations ......................... 47
5. Transmission of ITFS Call Signs .................... 48
E. Application Procedures ................................ 52
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Federal Communications Commission FCC 96-304
F. ITFS Programming Requirements ........................ 58
IV. ORDERING CLAUSES .................................... 59
I. INTRODUCTION
1
rds, Modulation Limits and
Aural Power Limitations ......................... 47
5. Transmission of ITFS Call Signs .................... 48
E. Application Procedures ................................ 52
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Federal Communications Commission FCC 96-304
F. ITFS Programming Requirements ........................ 58
IV. ORDERING CLAUSES .................................... 59
I. INTRODUCTION
1. The Commission has before it a request for declaratory ruling1 filed by a coalition of
99 parties with interests in the wireless cable industry (collectively, "Petitioners"),2 pursuant to
Section 1.2 of the Commission's Rules, 47 C.F.R. � 1.2.3 Petitioners seek a declaratory ruling
on their proposed "interim approach"4 to the use of digital modulation in MDS and ITFS upon
application by individual MDS or ITFS entities. Petitioners request that the Commission, based
on some uniform rule clarifications and waivers, avoid the need for developmental authorizations
and "routinely grant"5 MDS and ITFS applications proposing the use of digital modulation on a
non-interference basis, subject to further research and testing by the industry and the provisions
of any subsequent MDS and ITFS rulemaking on digital technology. Except as noted herein, for
the reasons discussed below, we grant Petitioners' request.
2. The ruling we now adopt will provide a quick and easy framework for wireless cable
operators and MDS or ITFS licensees to increase their channel capacity and service offerings
through the use of digital compression techniques. It will additionally enable the industry to gain
experience with a broad array of digital technology and to perform further testing in order to fine
tune performance measures for use of this technology hi wireless cable systems. By this action,
wireless cable becomes the first over-the-air terrestrial video programming service that we
authorize to utilize digital transmissions
techniques. It will additionally enable the industry to gain
experience with a broad array of digital technology and to perform further testing in order to fine
tune performance measures for use of this technology hi wireless cable systems. By this action,
wireless cable becomes the first over-the-air terrestrial video programming service that we
authorize to utilize digital transmissions. Thus, we accelerate the development of wireless cable
services and advance Congress' goal of "promotfing] competition ... hi order to secure lower
prices and higher quality services for American telecommunications consumers."6 We also seek
to promote the use of digital technology, along with its attendant benefits, by the educational
community.
1 Petition for Declaratory Ruling (hereinafter "Petition"), July 13, 1995.
* See Appendix A for a list of the parties.
3 "Wireless cable" is a service permitting delivery of video programming to subscribers utilizing spectrum
allocated to the Multipoint Distribution Service and the Multichannel Multipoint Distribution Service (collectively
referred to as "MDS"), as well as leased channels from the Instructional Television Fixed Service ("ITFS"). Wireless
cable resembles cable television, but instead of coaxial or fiber optic cable, wireless cable uses over-the-air
microwave radio channels to deliver programming to subscribers. Our use of the term "wireless cable" does not
imply that it constitutes cable television for statutory or regulatory purposes.
4 Petition at 11.
5 Id. at 13 n.24.
6 Telecommunications Act of 1996, Pub. L. No. 104-104, 110 Stat 56 (1996).
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Federal Communications Commission FCC 96-304
H. BACKGROUND
3
le uses over-the-air
microwave radio channels to deliver programming to subscribers. Our use of the term "wireless cable" does not
imply that it constitutes cable television for statutory or regulatory purposes.
4 Petition at 11.
5 Id. at 13 n.24.
6 Telecommunications Act of 1996, Pub. L. No. 104-104, 110 Stat 56 (1996).
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Federal Communications Commission FCC 96-304
H. BACKGROUND
3. The Commission has taken several actions in recent years to enhance the viability of
the wireless cable service and foster its competitiveness with wired cable and other multichannel
video programming distributors ("MVPDs").7 We have explained our reasons for taking such
actions:
[I]n providing communications services, the public interest is better served by
competition. A competitive industry framework promotes lower prices for
services, provides incentives for operators to improve those services and stimulates
economic growth. An essential component of competition is choice. As we
recognized in our recent report to Congress, consumers hi the market for video
programming do not have enough choices. Although competing technologies have
made major strides ... the cable television market remains largely
noncompetitive.8
Amendment of Parts 21 and 74 of the Commission's Rules With Regard to Filing Procedures in
the Multipoint Distribution Service and in the Instructional Television Fixed Service and
Implementation of Section 3090') of the Communications Act Competitive Bidding, Notice of
7 See Amendment of Parts 21, 43, 74, 78, and 94 of the Commission's Rules Governing Use of the
Frequencies in the 2.1 and 2.5 GHz Bands Affecting: Private Operational-Fixed Microwave Service, Multipoint
Distribution Service, Multichannel Multipoint Distribution Service, Instructional Television Fixed Service, & Cable
Television Relay Service, Second Order on Reconsideration, 10 FCC Red 7074 (1995) (hereinafter Second Wireless
Cable Reconsideration Order), ajfd, Third Order on Reconsideration and Order t
2.1 and 2.5 GHz Bands Affecting: Private Operational-Fixed Microwave Service, Multipoint
Distribution Service, Multichannel Multipoint Distribution Service, Instructional Television Fixed Service, & Cable
Television Relay Service, Second Order on Reconsideration, 10 FCC Red 7074 (1995) (hereinafter Second Wireless
Cable Reconsideration Order), ajfd, Third Order on Reconsideration and Order to Clarify in Gen. Docket Nos. 90-
54 and 80-113, MM Docket No. 94-131, and PP Docket No. 93-253, FCC 96-130 (released April 1, 1996)
(hereinafter Third Wireless Cable Reconsideration Order) (expanding the protected service area of MDS stations);
Amendment of Parts 21 and 74 of the Commission's Rules With Regard to Filing Procedures in the Multipoint
Distribution Service and in the Instructional Television Fixed Service and Implementation of Section 309(j) of the
Communications Act - Competitive Bidding, Report and Order, 10 FCC Red 9589 (1995) (hereinafter MDS Auction
Order) (adopting competitive bidding procedures to distribute unused MDS spectrum and streamlined measures to
process new MDS applications); Order on Reconsideration, 10 FCC Red 13821 (1995) (hereinafter MDS Auction
Reconsideration Order) (clarifying and enhancing the protected service area of ITFS channels). See also
Implementation of Section 19 of the Cable Television Consumer Protection and Competition Act of 1992: Annual
Assessment of the Status of Competition in the Market for the Delivery of Video Programming, First Report, 9 FCC
Red 7442, 7486 n.241 (1994) (hereinafter First Competition Report) (summarizing other significant Commission
actions taken in 1994 to promote the wireless cable service).
8 More recently, the Commission similarly concluded that the market for the distribution of video
programming is not yet competitive. See Annual Assessment of the Status of Competition in the Market for the
Delivery of Video Programming, Second Annual Report, 11 FCC Red 2060 (1995) (hereinafter Second Competition
Report)
ission
actions taken in 1994 to promote the wireless cable service).
8 More recently, the Commission similarly concluded that the market for the distribution of video
programming is not yet competitive. See Annual Assessment of the Status of Competition in the Market for the
Delivery of Video Programming, Second Annual Report, 11 FCC Red 2060 (1995) (hereinafter Second Competition
Report).
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Federal Communications Commission FCC 96-304
ProposedRulemaking, 9 FCC Red 7665,7666 (1994) (hereinafter MDSAuction NPRM) (footnote
omitted).
4. Various factors, including insufficient channel capacity, have been blamed for the
relatively low penetration of wireless cable systems, and the difficulties such systems have
experienced in competing with cable television systems.9 In addition, wireless cable operators
have been contending with increased competition from DBS providers,10 who are the first MVPDs
to implement digital technology on a wide scale. 11 Cable operators also plan to introduce digital
technology into their major markets this year or next year. 12
5. While we have recognized that "the difficulty of accumulating sufficient channel
capacity remains a major obstacle to many wireless cable operators," we have expressed hope that
"the combination of administrative improvements in wireless cable licensing and the use of digital
compression should help to alleviate this problem in the future." MDS Auction NPRM, 9 FCC
Red at 7666-67 (footnote omitted); see First Competition Report, 9 FCC Red at 7488. We expect
that the introduction of digital technology will enhance the service of wireless cable operators by
allowing opportunities for increased channel capacity and programming choices available to
consumers, sharper television pictures, a broader coverage area, and the provision of video, voice
and data services that cannot be offered currently.13 We have additionally concluded that
9 Second Competition Report, 1 1 FCC Red at 2096
chnology will enhance the service of wireless cable operators by
allowing opportunities for increased channel capacity and programming choices available to
consumers, sharper television pictures, a broader coverage area, and the provision of video, voice
and data services that cannot be offered currently.13 We have additionally concluded that
9 Second Competition Report, 1 1 FCC Red at 2096. Using NTSC analog transmission, there are a maximum
of 33 microwave channels available for wireless cable systems. This includes 13 MDS channels (Channels 1, 2 or
2A, E1-E4, F1-F4 and H1-H3) and the excess capacity on the 20ITFS channels (Channels A1-A4, B1-B4, C1-C4,
D1-D4 and G1-G4). Thus, wireless cable operators utilising traditional analog technology are unable to offer
potential subscribers as many channels as are typically offered by cable television systems or direct broadcast satellite ("DBS")-
10 Id.
11 Id. at 2147. Digitization is the process by which analog signals are digitized (converted to streams of " 1 "s
and "0"s) using an encoding process that extracts the information necessary for reconstruction of the input signal at
its destination. By transporting only essential information, the amount of bandwidth the signal occupies is
dramatically reduced. The ratio of compression determines the effective digital rate. For example, a highly
compressed ratio permits the operator to offer six program channels over one 6 MHz channel that would
accommodate only one program if the ratio of compression is less..
12 Id. at 2148.
13 Second Competition Report, 11 FCC Red at 2065-66. The Second Competition Report also described how
"[i]n anticipation of emerging competition in markets for the delivery of video services, many MVPDs are apparently
planning [to] enhance their standard services and expand their offerings to include . . . interactive services." Id. at
2144 (footnote omitted)
sion is less..
12 Id. at 2148.
13 Second Competition Report, 11 FCC Red at 2065-66. The Second Competition Report also described how
"[i]n anticipation of emerging competition in markets for the delivery of video services, many MVPDs are apparently
planning [to] enhance their standard services and expand their offerings to include . . . interactive services." Id. at
2144 (footnote omitted). Such efforts require increased bandwidth and two-way network capabilities, and MVPDs
using wireless distribution methods are focusing primarily on digital compression as their strategy to achieve these
technical objectives. Id.
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Federal Communications Commission FCC 96-304
advances in digital technology "have the potential to exert a major influence on the structure of
the market for the delivery of video programming." Second Competition Report, 11 FCC Red
at 2143. By this ruling, we intend to permit the benefits of digital technology to be realized by
ITFS licensees and their educational communities. 14 We note that several ITFS licensees that do
not lease excess channel capacity are interested in quickly implementing digital technology. See
Petition at iii. Thus, the Commission's interests in fostering competition in the video
programming services market and promoting the use of ITFS spectrum for educational
programming will clearly be advanced by authorizing wireless cable operators to employ digital
technologies. In adopting new procedures for the filing of applications for new MDS stations,
we stated:
The filing system and procedures we adopt herein are expected to ... afford
wireless cable operators the flexibility to ... implement digital technologies. . .
. We believe that our rules will facilitate the transition to digital transmissions
If modification of our rules becomefs] necessary, we will act promptly to ensure
that our rules in no way impede the digital future.
MDS Auction Order, 10 FCC Red at 9606
rocedures we adopt herein are expected to ... afford
wireless cable operators the flexibility to ... implement digital technologies. . .
. We believe that our rules will facilitate the transition to digital transmissions
If modification of our rules becomefs] necessary, we will act promptly to ensure
that our rules in no way impede the digital future.
MDS Auction Order, 10 FCC Red at 9606. See also Second Wireless Cable Reconsideration
Order, 10 FCC Red at 7093 (discussing "the imminent transition from analog to digital
transmissions for MDS stations").
6. In light of the public interest in a competitive video programming services market, it
is important to authorize wireless cable operators to use digital transmissions. We agree with
Petitioners that a rulemaking proceeding for developing permanent standards for use of digital
technology would be lengthy, and would be delayed by a dependence upon additional testing that
has not yet been completed, thus putting the wireless cable industry at a further competitive
disadvantage with respect to other video programming services, which either have already
implemented digital technology or will have done so by the completion of such a proceeding.
Moreover, the Petitioners requesting this ruling are comprised of MDS and ITFS licensees,
wireless cable operators, equipment manufacturers, industry engineers, the Wireless Cable
Association International, Inc. and other industry groups, representing a strong and rare consensus
amongst significant industry participants, who often have divergent interests. Accordingly, we
14 See Amendment of Part 74 of the Commission's Pules Governing Use of the Frequencies in the Instructional
Television Fixed Service, Notice of Proposed Rule Making, 8 FCC Red 2828,2831 (1993) (hereinafter ITFS Channel
Loading NPRM) ("We also believe . . . [that] the ITFS service will be deeply affected by the arrival of digital
compression technology.")
divergent interests. Accordingly, we
14 See Amendment of Part 74 of the Commission's Pules Governing Use of the Frequencies in the Instructional
Television Fixed Service, Notice of Proposed Rule Making, 8 FCC Red 2828,2831 (1993) (hereinafter ITFS Channel
Loading NPRM) ("We also believe . . . [that] the ITFS service will be deeply affected by the arrival of digital
compression technology.").
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Federal Communications Commission FCC 96-304
believe that a declaratory ruling on an interim approach to the employment of digital technology
in the MDS and ITFS services is the appropriate measure at this juncture. 15
7. The following eight parties filed timely comments on this request for declaratory
ruling: 16 Bell Atlantic; 17 NYNEX Corporation (NYNEX); Hammett & Edison, Inc. (Hammett),
consulting engineers; ITS Corporation (ITS), an equipment manufacturer and co-signor of the
Petition; Kraskin & Lessee, on behalf of several independent telephone companies;18 the Rural
Wireless Cable Coalition (Rural Coalition);19 SR Telecom Inc. (SR Telecom), an equipment
manufacturer; and Tarrant County Junior College District, Education Service Center Region 10
and Richardson Independent School District (Tarrant County), ITFS licensees in the Dallas-Fort
Worth area. Petitioners filed a timely reply.
15 Cf. Amendment of Parts 21, 43, 74, 78, and 94 of the Commission's Rules Governing Use of the Frequencies
in the 2.1 and 2.5 GHz Bands Affecting: Private Operational-Fixed Microwave Service, Multipoint Distribution
Service, Multichannel Multipoint Distribution Service, Instructional Television Fixed Service, and Cable Television
Relay Service, Report and Order, 5 FCC Red 6410 (1990) (hereinafter Wireless Cable Order). In the Wireless Cable
Order, the Commission encouraged MDS and ITFS licensees to apply for authorization to use Comband analog
compression technology, which would expand wireless cable channel capacity
channel Multipoint Distribution Service, Instructional Television Fixed Service, and Cable Television
Relay Service, Report and Order, 5 FCC Red 6410 (1990) (hereinafter Wireless Cable Order). In the Wireless Cable
Order, the Commission encouraged MDS and ITFS licensees to apply for authorization to use Comband analog
compression technology, which would expand wireless cable channel capacity. The Commission, however, declined
to conduct a rulemaking proceeding: "Because Comband and other such technologies are still hi development, we
will not make specific rule modifications at this time." Id. at 6417. Similarly, Petitioners liken their request to the
initial requests to use digital modulation in the DBS service, where the Mass Media Bureau also avoided a lengthy
rulemaking proceeding and authorized digital transmission on the basis of minor license modification applications.
See United States Satellite Broadcasting Company, Inc., 1 FCC Red 7247, 7249 (Vid. Serv. Div. 1992) (hereinafter
USSB); Hughes Communications Galaxy, Inc., 8 FCC Red 8116, 8117 (Vid. Serv. Div. 1993) (hereinafter Hughes).
16 See Public Notice, Pleading Cycle Established for Comments on Request for Declaratory Ruling on the Use
of Digital Modulation by Multipoint Distribution Service and Instructional Television Fixed Service Stations, 10 FCC
Red 10915 (Mass Media Bur. 1995).
17 The Bell Atlantic telephone companies are Bell Atlantic-Delaware, Inc., Bell Atlantic-Maryland, Inc., Bell
Atlantic-New Jersey, Inc., Bell Atlantic-Pennsylvania, Inc., Bell Atlantic-Virginia, Inc., Bell Atlantic-Washington,
D.C., Inc. and Bell Atlantic-West Virginia, Inc. Bell Atlantic and NYNEX Corporation recently made a substantial
investment in CAI Wireless Systems, Inc., an existing wireless cable operator
lephone companies are Bell Atlantic-Delaware, Inc., Bell Atlantic-Maryland, Inc., Bell
Atlantic-New Jersey, Inc., Bell Atlantic-Pennsylvania, Inc., Bell Atlantic-Virginia, Inc., Bell Atlantic-Washington,
D.C., Inc. and Bell Atlantic-West Virginia, Inc. Bell Atlantic and NYNEX Corporation recently made a substantial
investment in CAI Wireless Systems, Inc., an existing wireless cable operator.
18 Alenco Communications, Inc., Brazoria Telephone Company, Cap Rock Telephone Cooperative, Inc., Coastal
Utilities, Inc., Coleman County Broadcasting, Inc., Farmers Telephone Cooperative, Inc., Horry Telephone
Cooperative, Inc., Reserve Telephone Company, Inc., Tohono O'odham Utility Authority and XIT
Telecommunication and Technology, Inc.
19 The members of the Rural Coalition, Central Texas Wireless TV, Inc., Leaco Rural Telephone Cooperative,
Inc. and Adams Telecom, Inc., provide wireless cable service hi Texas, New Mexico and Illinois.
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Federal Communications Commission FCC 96-304
8. The commenters generally support the Petition and the Commission's efforts to
facilitate the transition of wireless cable to digital technology.20 Most of the commenters believe
that the transitional approach outlined in the requested ruling will increase the competitive
viability of wireless cable in the MVPD marketplace by allowing operators to offer a competitive
number of channels, without causing harmful interference to existing analog systems, and without
the unnecessary regulatory delay of a rulemaking proceeding.21
ffl. DISCUSSION
A. Commission Rules and Cases in Support of Authorization of Digital Modulation
9
uling will increase the competitive
viability of wireless cable in the MVPD marketplace by allowing operators to offer a competitive
number of channels, without causing harmful interference to existing analog systems, and without
the unnecessary regulatory delay of a rulemaking proceeding.21
ffl. DISCUSSION
A. Commission Rules and Cases in Support of Authorization of Digital Modulation
9. Petitioners recognize that the MDS and ITFS rules contained in Parts 21 and 74 are
oriented toward transmission of NTSC analog video programming signals, but they nonetheless
maintain that the rules allow for a variety of modulation schemes, and that the Commission has
interpreted the rules to promote such flexibility where no cochannel or adjacent channel
interference will result. Petition at 3-4. See, e.g., General Electric Co., 60 RR 2d 1665 (Comm.
Car. Bur. 1986) (hereinafter Combandl); General Electric Co., 61 RR 2d 143 (Mass Media Bur.
1986) (hereinafter Comband II). In particular, Petitioners refer to the similar language describing
emissions in Sections 21.905 and 74.936 of the Commission's Rules. Both of these rules provide
that MDS or ITFS stations will "normally" employ amplitude modulation for the transmission of
the visual signal and frequency modulation for the aural signal. 47 C.F.R. �� 21.905(a) and
74.936(a). Petitioners suggest that the use of the term "normally" in both rules reflects a
recognition by the Commission that modulation schemes other than NTSC may be appropriate
for MDS and ITFS. Petition at 12-13 n.23. Petitioners further point out that Section 21.905(b)
specifically contemplates that "[fjor purposes other than standard television transmission, different
types of emissions may be authorized . . . ." See Petition at 3 n.4
rm "normally" in both rules reflects a
recognition by the Commission that modulation schemes other than NTSC may be appropriate
for MDS and ITFS. Petition at 12-13 n.23. Petitioners further point out that Section 21.905(b)
specifically contemplates that "[fjor purposes other than standard television transmission, different
types of emissions may be authorized . . . ." See Petition at 3 n.4. In promulgating the initial
rules governing the MDS service, including Section 21.90S,22 the Commission expressed
confidence that MDS licensees "will imaginatively exploit the technical possibilities of MDS."
Amendment of Parts 1, 2, 21, and 43 of the Commission's Rules and Regulations to Provide for
Licensing and Regulation of Common Carrier Radio Stations in the Multipoint Distribution
Service, 45 FCC 2d 616, 619 (1974) (hereinafter MDS Allocation Order). Moreover, nothing in
20 Petitioners emphasize that not one commenting party has opposed a grant of the requested ruling. Reply
at 2.
21 See, e.g., Comments of Bell Atlantic at 2-4 (For comparative purposes, Bell Atlantic states that a competing
MVPD system, DIRECTV, Inc., offers approximately 175 channels on a digital basis through DBS service.); NYNEX
at 3-6; Hammett at 1-2; Kraskin & Lessee at 1-2; Rural Coalition at 1-2.
22 Section 21.905(a) and (b) has remained essentially unchanged since its inception.
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Federal Communications Commission FCC 96-304
the original implementation of Section T4.93623 controverts Petitioners' interpretation of that
rule.24 Thus, we agree with Petitioners' reading of Sections 21.905 and 74.936 as allowing
sufficient latitude for authorization of digital transmissions over MDS and ITFS stations.
10. Other rules applicable to MDS and ITFS in Parts 21 and 74 also permit authorization
of the use of digital technology. Section 21.907(c) provides in part that "[i]n addition to the
standard television transmission service ..
agree with Petitioners' reading of Sections 21.905 and 74.936 as allowing
sufficient latitude for authorization of digital transmissions over MDS and ITFS stations.
10. Other rules applicable to MDS and ITFS in Parts 21 and 74 also permit authorization
of the use of digital technology. Section 21.907(c) provides in part that "[i]n addition to the
standard television transmission service ... the licensee may offer a television service not
meeting such standards if the tariff or contract clearly describes the type and quality of the
service and distinguishes it from the standard service . . . ." 47 C.F.R. � 21.907(c). As was
explained nearly 10 years ago hi a declaratory ruling authorizing the use of Comband analog
compression technology for MDS transmissions, "Section (c) of 21.907 was specifically added
to enable MDS carriers to use non-standard transmitters and to encourage developments such as
Comband." Comband I, 60 RR 2d at 1669; see also MDS Allocation Order, 45 FCC 2d at 623-
24.^ Furthermore, in amending Section 74.938, the Commission elaborated that "we are
persuaded that ITFS operators should not be restricted to NTSC format. . . when other video
standards may be better suited to their needs.. . . For these reasons, we are amending our rules
to relax the technical standards for ITFS transmissions." Amendment of Part 74 of the
Commission's Rides and Regulations in regard to the Instructional Television Fixed Service, 98
FCC 2d 925, 928 (1984) (hereinafter ITFS Technical Order).
11. Petitioners also cite several cases to support authorization of digital transmission
under the current rules
ese reasons, we are amending our rules
to relax the technical standards for ITFS transmissions." Amendment of Part 74 of the
Commission's Rides and Regulations in regard to the Instructional Television Fixed Service, 98
FCC 2d 925, 928 (1984) (hereinafter ITFS Technical Order).
11. Petitioners also cite several cases to support authorization of digital transmission
under the current rules. In Comband I and Comband II, the Common Carrier Bureau26 and Mass
23 See Amendment of Parts 2 and 4 of the Commission's Rules and Regulations to Establish a New Class of
Educational Television Service for the Transmission of Instructional and Cultural Material to Multiple Receiving
Locations on Channels in the 1990-2110 Mc/s or 2500-2690 Mc/s Frequency Band, 39 FCC 846 (1963) (hereinafter
ITFS Allocation Order). Section 74.936 was originally codified as Section 4.936.
24 The Mass Media Bureau has held that while Section 74.936, among other rules dealing with ITFS technical
standards, is predicated on the assumption that NTSC transmission will be utilized, other transmission formats may
be considered where, as here, actual experimental test results are submitted for evaluation to insure that acceptable
performance standards are achieved. See Comband II, 61 RR 2d at 145-46, where the Bureau concluded that the
use of Comband analog compression technology is consistent with the ITFS technical standards in Part 74 of the
Commission's Rules.
25 While Section 21.907 was revised in 1987 in the context of a rulemaking permitting MDS licensees to
provide service on a non-common carrier basis, the rule was not changed substantively with respect to the provisions
discussed supra and infra.
26 Until June, 1994, when we centralized the processing and regulatory jurisdiction over wireless cable in the
Mass Media Bureau, the Common Carrier Bureau had responsibility for MDS
in 1987 in the context of a rulemaking permitting MDS licensees to
provide service on a non-common carrier basis, the rule was not changed substantively with respect to the provisions
discussed supra and infra.
26 Until June, 1994, when we centralized the processing and regulatory jurisdiction over wireless cable in the
Mass Media Bureau, the Common Carrier Bureau had responsibility for MDS. See Amendment of Parts 0 and 1 of
the Commission's Rules to Reflect a Reorganization of Multipoint and Multichannel Multipoint Distribution Service
Regulation, 9 FCC Red 3661 (1994).
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Federal Communications Commission FCC 96-304
Media Bureau, respectively, authorized for MDS and ITFS licensees use of Comband analog
compression technology, which allows for transmission of two analog video signals on a single
6 MHz channel. The Bureaus concluded that the Comband system is consistent with Parts 21 and
74 of the Commission's Rules and approved the use of Comband, subject to application to the
Commission in individual cases, where the applicant could demonstrate non-interference and
where the applicant specified a type accepted Comband transmitter. The Commission later
confirmed that "[tjhere is nothing in our current rules to restrict use of Comband transmission by
MDS or ITFS licensees, and we do intend, when possible, to accommodate the widest possible
voluntary usage of this or any other technology that can achieve spectrum efficiencies of this
nature." Wireless Cable Order, 5 FCC Red at 6417.27 These cases further confirm our finding
that the regulatory framework in Parts 21 and 74 of the Commission's Rules governing MDS and
ITFS28 can accommodate the use of transmission formats other than NTSC analog, including the
use of digital modulation techniques.
12. SR Telecom supports the Petition provided that any subsequent rule changes facilitate,
rather than impede, the provision over the MDS spectrum of digital wireless loop service, a two-
way communications service
4 of the Commission's Rules governing MDS and
ITFS28 can accommodate the use of transmission formats other than NTSC analog, including the
use of digital modulation techniques.
12. SR Telecom supports the Petition provided that any subsequent rule changes facilitate,
rather than impede, the provision over the MDS spectrum of digital wireless loop service, a two-
way communications service. SR Telecom Comments at 4-5. In response to SR Telecom's
comments, Petitioners explain that the testing underlying the Petition did not evaluate any two-
way transmissions, and involved the use of modulation methods that differ significantly from the
method proposed by SR Telecom. "Thus, the record is inadequate to permit a reasoned
discussion of the merits of SR's wireless local loop system," Reply at 2 n.2. Petitioners suggest
that the Commission invite SR Telecom to submit a detailed petition which should include test
data and proposed interference standards. Id The Commission recently reiterated that "[w]e will
allow alternative uses other than wireless cable video transmission if the applicant can satisfy
MDS technical rules or adequately support waivers of those rules." MDS Auction
Reconsideration Order, 10 FCC Red at 13825. However, as Petitioners indicate, no data was
submitted here for consideration of the merits of SR Telecom's proposal. Therefore, we find
clarification of the use of digital wireless loop technology on MDS frequencies beyond the scope
of this ruling.29
27 Similarly, in USSB, Hughes' DBS application to employ digital modulation was granted on the condition
that the use of digital modulation would require no more interference protection than the system used for planning
purposes in applicable international agreements. 7 FCC Red at 7249
ation of the use of digital wireless loop technology on MDS frequencies beyond the scope
of this ruling.29
27 Similarly, in USSB, Hughes' DBS application to employ digital modulation was granted on the condition
that the use of digital modulation would require no more interference protection than the system used for planning
purposes in applicable international agreements. 7 FCC Red at 7249. The Video Services Division later determined
that the use of digital transmission as proposed by Hughes would not cause greater interference than that caused by
the system used for planning purposes, and the condition was removed from the authorization. Hughes, 8 FCC Red
at 8117. While DBS is not governed by Parts 21 or 74 of the Commission's Rules, USSB and Hughes are illustrative
of other instances where digital video transmission authority has been granted on the condition of meeting existing
interference criteria.
28 See paras. 9-10, supra.
29 Our action is without prejudice to any subsequent filing by SR Telecom.
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Federal Communications Commission FCC 96-304
B. Modulation Methods
13. Petitioners request interim authorization of two types of digital modulation:
Quadrature Amplitude Modulation ("QAM") and Vestigial Sideband ("VSB"). While the test data
submitted in support of the Petition focuses on the specific densities of 64-QAM and 8-VSB,
Petitioners also seek Commission authorization for the use of both higher and lower modulation
densities of QAM and VSB, to gain experience with "a wider array of... modulation densities
. . . before permanent rules can be adopted." Petition at 9.30 While supporting the Petition,
NYNEX questions Petitioners' commitment to "conform . . . operation to whatever permanent
rules the Commission may adopt in the future to govern digital modulation...." Petition at 1-2;
see NYNEX Comments at 7-8
ties of QAM and VSB, to gain experience with "a wider array of... modulation densities
. . . before permanent rules can be adopted." Petition at 9.30 While supporting the Petition,
NYNEX questions Petitioners' commitment to "conform . . . operation to whatever permanent
rules the Commission may adopt in the future to govern digital modulation...." Petition at 1-2;
see NYNEX Comments at 7-8. NYNEX argues that licensees should avoid interference with
other licensees as may be required by current and future rules, but should not be required to
commit to a subsequent changeout in the digital technology deployed merely because the
Commission adopts a different "standard" modulation technology. NYNEX explains that "[tjhere
are currently two competing methods of digital modulation (QAM and VSB), with perhaps others
in development, which should be authorized by the Commission. Thereafter, each provider will
make an election of technology by market .. . There is no reason for the Commission to chose
[sic] among competing technologies or to specify a 'standard' technology." NYNEX Comments
at 8 (footnote omitted). NYNEX observes that while a licensee is likely to use a single
technology for each market, which would make a subsequent changeout hi technology particularly
costly and challenging, the Commission should allow different digital modulation technologies
to be deployed by different licensees in the same market, or by the same licensee in different
markets. Id. at 8-9. Petitioners did not reply to these comments.
14. Though Petitioners request authorization of the use of QAM and VSB modulation,
they do not ask for adoption of a "standard" technology or the exclusion of other modulation
methods. In fact, Petitioners specify that they do not "mean to suggest that other modulation
methods . . . cannot be employed under appropriate circumstances." Petition at 15 n.27
ers did not reply to these comments.
14. Though Petitioners request authorization of the use of QAM and VSB modulation,
they do not ask for adoption of a "standard" technology or the exclusion of other modulation
methods. In fact, Petitioners specify that they do not "mean to suggest that other modulation
methods . . . cannot be employed under appropriate circumstances." Petition at 15 n.27.
Petitioners add that if the proponent of another digital modulation method can demonstrate that
its proposal will not cause harmful interference, there is no reason not to issue a declaratory
ruling similar to that requested by Petitioners. Id.31 We are not now proposing to adopt one or
30 Petitioners also report that other test results for 32-QAM modulation, obtained at the Advanced Television
Testing Center in connection with our Digital Television proceeding, "are very consistent with" the test results
produced in support of the Petition. Id. at 24 nJ9.
31 We will consider future requests for declaratory ruling where the requesters can demonstrate that their
proposals satisfy MDS and FTPS technical rules or adequately support waivers of those rules. In particular,
requesters would need to show that other modulation techniques could be used in a manner that would not interfere
with MDS and ITFS analog and digital operations. See Comband II, 61 RR 2d at 145-46 ("When other formats .
. . are considered ... we believe that it is appropriate to rely upon actual experimental test results to insure mat
acceptable performance standards are achieved.").
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Federal Communications Commission FCC 96-304
more "standard" digital technologies. This ruling is limited to QAM and VSB. We interpret
Sections 21.905, 21.907(c), 74.936, and 74.938 of the Commission's Rules as enabling us to
authorize use of these digital modulation formats over MDS and ITFS stations, provided that such
use will not result in harmful interference. See paras. 9-10, supra and para
l Communications Commission FCC 96-304
more "standard" digital technologies. This ruling is limited to QAM and VSB. We interpret
Sections 21.905, 21.907(c), 74.936, and 74.938 of the Commission's Rules as enabling us to
authorize use of these digital modulation formats over MDS and ITFS stations, provided that such
use will not result in harmful interference. See paras. 9-10, supra and para. 52, infra?1 As set
forth below, based on the test results submitted by Petitioners, we agree with Petitioners that use
of the VSB and QAM modulation formats up to the densities of 8-VSB and 64-QAM, together
with the current MDS and ITFS interference protection criteria,33 would not be likely to cause
harmful interference to MDS and ITFS service.
15. Petitioners also argue that using QAM and VSB "will ensure excellent interference
protection no matter what densities of VSB or QAM are employed for the digital signals."
Petition at 24-25; see para. 20, infra. We are persuaded that the wireless cable industry also
should have an opportunity to gain practical experience with higher modulation densities, those
up to 16-VSB and 256-QAM. This is consistent with our interpretation of the rules for emission
types, as discussed above. However, we wish to ensure that use of higher densities will not
present an increased likelihood of causing harmful interference to MDS or ITFS service.
Therefore, MDS and ITFS licensees may utilize such densities provided, in their applications,
they submit supplemental measurement data specific to these higher modulation levels, akin to
the data provided by Petitioners in support of the Petition. See Petition at Appendix B, Rationale
for Interim Implementation of Wireless Cable Digital Transmission (hereinafter Interim
Implementation Report); Report on Wireless Cable Interference Testing, April 27-May 4, 1995
(hereinafter Interference Testing Report). But see para. 19, infra
ific to these higher modulation levels, akin to
the data provided by Petitioners in support of the Petition. See Petition at Appendix B, Rationale
for Interim Implementation of Wireless Cable Digital Transmission (hereinafter Interim
Implementation Report); Report on Wireless Cable Interference Testing, April 27-May 4, 1995
(hereinafter Interference Testing Report). But see para. 19, infra. We will provide additional
flexibility by not prohibiting the simultaneous deployment of different authorized digital
technologies in the same market by different licensees.34 Further, pursuant to Sections 21.905,
21.907(c), and 74.936 of the Commission's Rules, which provide for use of more than one
emission type,35 during this interim period, licensees may alternate between analog and digital
transmission systems, in order to compare their effects and make full use of available transmitting
and receiving facilities.36
32 See also Comband I, 60 RR 2d at 1670; Comband II, 61 RR 2d at 146.
33 See para. 22, infra.
34 As described in para. 52, infra, we will accept modification applications or amendments to use digital
technology pursuant to this ruling on a per station basis. Therefore, we will not require a licensee to use the same
modulation in different markets.
35 See paras. 9-10, supra.
36 See paras. 45-46, infra. See also Tarrant County Comments at 4.
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Federal Communications Commission FCC 96-304
C. Interference Considerations
16. As the cornerstone of their interim proposals for digital wireless cable, Petitioners
emphasize that the Commission must assure that use of digital modulation will not cause harmful
electromagnetic interference to nearby analog or digital stations. See Petition at 16
See also Tarrant County Comments at 4.
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Federal Communications Commission FCC 96-304
C. Interference Considerations
16. As the cornerstone of their interim proposals for digital wireless cable, Petitioners
emphasize that the Commission must assure that use of digital modulation will not cause harmful
electromagnetic interference to nearby analog or digital stations. See Petition at 16. Based on
industry test results, Petitioners submit that use of the existing interference protection ratios for
analog MDS and ITFS stations, together with a small relaxation in the currently permitted levels
of out-of-channel emissions, is a conservative approach that would provide more than adequate
interference protection to such stations. See id. at 21-22 and 27-28.
1. Test Procedures
17. The Petition appends a report of the findings of extensive tests that have been
conducted with 64-QAM and 8-VSB modulation in a closed laboratory setting using actual
wireless cable equipment, as well as ITFS equipment and receiving configurations.37 Two basic
receive installations were employed in the tests, one replicating a typical wireless cable subscriber
installation and the other simulating an ITFS receive site that is not part of a wireless cable
system. With each configuration, several television receivers were used, and for each
combination of equipment and transmission mode, the thresholds of perceptibility of interference
to pictures and sound were measured, as well as the signal ratios producing a CCIR grade 4 level
of television picture impairment. Petitioners explain that CCIR grade 4 was employed for these
tests to provide a conservative safety margin of interference protection.38 Accordingly, Petitioners
conclude that the interference results discussed in the Interim Implementation Report demonstrate
a level of interference protection to existing NTSC analog facilities better than the current analog-
to-analog protection.39 Petition at 20-21
explain that CCIR grade 4 was employed for these
tests to provide a conservative safety margin of interference protection.38 Accordingly, Petitioners
conclude that the interference results discussed in the Interim Implementation Report demonstrate
a level of interference protection to existing NTSC analog facilities better than the current analog-
to-analog protection.39 Petition at 20-21. Petitioners emphasize that the tests analyzed only the
susceptibility of analog MDS/ITFS reception to cochannel and adjacent channel interference
37 Petitioners state that 2,337 subjective evaluations and measurements were conducted. These tests are
described generally in the Petition at 18-22. A full description of the test procedures and results is given in the
Interim Implementation Report.
38 The CCIR impairment scale grades are: 5 - Imperceptible; 4 - Perceptible, but not annoying; 3 - Slightly
annoying; 2 - Annoying; and 1 - Very annoying. Petition at 20 n.35.
39 The current 45 dB cochannel desired-to-undesired (D/U) signal strength ratio is based on TASO grade 3
picture quality, which is defined as "passable." Report of the Television Allocations Study Organization to the
Federal Communications Commission (March, 1959). We agree with Petitioners that digital-to-analog protection
standards based on a CCIR grade 4 result offer greater protection than do the current analog standards. We further
agree with Petitioners that CCIR grade 4 quality should be treated as an interim measure, to be reexamined when
more information becomes available on the performance of digital technology. See Petition at 21 n.36.
18850
Federal Communications Commission FCC 96-304
caused by digital signals.40 Because digital signals are "more robust to interference" than are
analog signals, application of the digital-to-analog protection ratios to digital-to-digital reception
will even further limit the likelihood of interference. Petition at 21-22; see Interim
Implementation Report at 3.
18
e Petition at 21 n.36.
18850
Federal Communications Commission FCC 96-304
caused by digital signals.40 Because digital signals are "more robust to interference" than are
analog signals, application of the digital-to-analog protection ratios to digital-to-digital reception
will even further limit the likelihood of interference. Petition at 21-22; see Interim
Implementation Report at 3.
18. Based on the results of these tests, Petitioners conclude that under their requested
interim parameters and rule waivers, QAM and VSB digital modulation can be implemented
without causing interference to analog systems or other digital systems. Petition at 17.
Petitioners maintain that following the technical proposals described below will enable the
Commission to authorize the use of digital modulation techniques without requiring applicants
to present information beyond the standard interference studies now required by 47 C.F.R.
�� 21.902 and 74.903, and without the staff conducting any materially different engineering
analysis than is now used to process MDS and ITFS applications. Petition at 18. Petitioners also
state that the Commission should rapidly grant applications to use digital technology based on
the consent of all neighboring stations, where such consent is obtained. Petition at 16.
19. Petitioners concede that as the modulation densities are increased, the susceptibility
of digital receivers to interference likewise increases. Thus, Petitioners encourage the continued
use of the current conservative 45 dB cochannel and 0 dB adjacent channel interference protection
criteria in order to accommodate use of high modulation densities, until further testing can be
completed to establish optimum digital interference criteria. Petition at 22 n.38; see para. 20,
infra
digital receivers to interference likewise increases. Thus, Petitioners encourage the continued
use of the current conservative 45 dB cochannel and 0 dB adjacent channel interference protection
criteria in order to accommodate use of high modulation densities, until further testing can be
completed to establish optimum digital interference criteria. Petition at 22 n.38; see para. 20,
infra. While we believe that the current interference protection criteria are sufficiently
conservative, we specify that we will not provide additional interference protection for digital
systems with higher modulation densities.
2. Interference Protection Ratios and Out-of-Band Emissions Limitations
20. Petitioners first propose the continued employment of the current 45 dB cochannel
and 0 dB adjacent channel41 D/U signal strength ratios as interim interference protection criteria,
while awaiting the results of further testing from which to develop recommendations for
permanent protection ratios. Petitioners assert that the tests conducted verify that these
interference criteria, when applied to a digital-to-analog interference situation, will yield a picture
40 All interference results submitted with the Petition reflected the relationship between the peak power of
NTSC analog signals and the average power of digital signals. Id. at 19-20 n.32; see paras. 26-27, infra.
41 See Sections 21.902(b) and 74.903(a) of the Commission's Rules. Under Section 74.903(aX2), ITFS stations
constructed before May 26, 1983 are entitled to at least 10 dB adjacent channel desired-to-undesired ("D/U")
protection, unless the receive site under consideration has been subsequently upgraded to utilize more modem
equipment. This ruling will refer to the 0 dB standard that is applicable to MDS stations and to most ITFS receive
sites, but does not modify the additional measure of D/U protection accorded ITFS stations constructed before May
26, 1983
adjacent channel desired-to-undesired ("D/U")
protection, unless the receive site under consideration has been subsequently upgraded to utilize more modem
equipment. This ruling will refer to the 0 dB standard that is applicable to MDS stations and to most ITFS receive
sites, but does not modify the additional measure of D/U protection accorded ITFS stations constructed before May
26, 1983.
18851
Federal Communications Commission FCC 96-304
quality better than the picture currently delivered when these criteria are applied to an analog-to-
analog interference situation. Petition at 24.42 The tests also showed that the degradation in aural
distortion and stereo separation caused by 0 dB adjacent channel operation is "insignificant" in
a digital-to-analog interference situation. Id. Petitioners additionally maintain that adhering to
the current interference criteria as an interim step will allow an easy fall-back to analog
transmission if such a change becomes necessary. Id.
21. Petitioners further request relaxation of the limitations on out-of-band emissions
(spectral mask), found in Sections 21.908(b) and 74.936(b) of the Commission's Rules, as these
limitations relate to digital emissions. Specifically, Petitioners seek out-of-band emission
limitations of:
38 dB attenuation relative to the licensed average power level43 at the channel
edges, constant slope attenuation from that level to 60 dB attenuation at 3 MHz
above the upper and below the lower channel edge, and 60 dB attenuation below
the licensed average power level at all other frequencies.44
Petition at 26. Petitioners contend that application of the current analog spectral mask to digital
use during the interim period both would be unnecessarily restrictive and could be very costly
to wireless cable operators; for example, requiring the use of expensive filtering
ow the lower channel edge, and 60 dB attenuation below
the licensed average power level at all other frequencies.44
Petition at 26. Petitioners contend that application of the current analog spectral mask to digital
use during the interim period both would be unnecessarily restrictive and could be very costly
to wireless cable operators; for example, requiring the use of expensive filtering. Petitioners
report that the tests underlying the Petition demonstrate that even when the spectral mask is
loosened, as proposed, a digital station is less likely to cause adjacent channel interference than
42 The test results show that cochannel and adjacent channel protection ratios of 45 dB and 0 dB, respectively,
yield a picture quality between CCIR grade 4, where interference is "perceptible, but not annoying," and the threshold
of visibility ("TOY"), where the effects of the interfering, undesired signal first become visible in the picture of the
desired signal. For example, in the case of a scrambled, desired analog signal, for 64 QAM modulation of the
undesired signal, the mean cochannel D/U ratios for all receivers tested are 46.9 dB for TOY and 40.5 dB for a
CCIR grade 4 picture quality; for 8-VSB digital modulation, the corresponding mean values are 45.6 dB for TOY
and 39.1 dB for CCIR grade 4. Petition at 19, 23-24; see Interference Testing Report at 4, 7.5-26. The 45 dB
protection ratio now applied between stations with analog transmissions yields a "passable" TASO grade 3 picture
quality. See note 39, supra
43 See para. 27, infra.
44 Sections 21.908(b) and 74.936(b) both currently provide for out-of-band emissions limitations of:
38 dB relative to the peak visual carrier at the channel edges and constant slope attenuation from
this level to 60 dB ... at / MHz below the lower band edge and 0.5 MHz above the upper band
edge. All out-of-band emissions extending beyond these frequencies shall be attenuated at least
60 dB below the peak visual carrier power.
47 C.F.R
tly provide for out-of-band emissions limitations of:
38 dB relative to the peak visual carrier at the channel edges and constant slope attenuation from
this level to 60 dB ... at / MHz below the lower band edge and 0.5 MHz above the upper band
edge. All out-of-band emissions extending beyond these frequencies shall be attenuated at least
60 dB below the peak visual carrier power.
47 C.F.R. �� 21.908(b) and 74.936(b) (emphasis added).
18852
Federal Communications Commission FCC 96-304
an analog station meeting the existing mask. Id. at 27.45 Therefore, Petitioners assert that a
"blanket waiver" of Sections 21.908(b) and 74.936(b) for digital transmitters will benefit the
"public interest in rapid, low-cost introduction of digital technology" in that it "will allow much
of the installed base of analog transmission equipment to be converted rapidly and inexpensively
to digital usage without sacrificing interference protection standards." Id. at 27-28.
22. We have reviewed the test results submitted with the Petition and are satisfied that
retaining the current 45 dB cochannel and 0 dB adjacent channel D/U signal strength protection
ratios will enable us as an interim step to authorize the use of the QAM and VSB digital
modulation formats requested by Petitioners without harmful interference to analog MDS and
ITFS service. See paras. 14-15 and note 39, supra. In view of the results obtained in connection
with the Commission's Digital Television proceeding, we are also confident that harmful
interference will not occur among digital MDS and ITFS stations. See Final Report and
Recommendations of the Advisory Committee on Advanced Television Service (November 28,
1995).
23. Generally, unless there is an interference agreement between the affected parties,
applicants must protect the 56.33 km (35 mile) service areas of MDS "incumbent" stations, those
authorized or proposed on or before September 18,1995
ur among digital MDS and ITFS stations. See Final Report and
Recommendations of the Advisory Committee on Advanced Television Service (November 28,
1995).
23. Generally, unless there is an interference agreement between the affected parties,
applicants must protect the 56.33 km (35 mile) service areas of MDS "incumbent" stations, those
authorized or proposed on or before September 18,1995. Such interference protection must also
be afforded to previously authorized or proposed service areas of ITFS stations. In expanding
the protected service areas of ITFS stations and MDS incumbent stations, we recognized that
there would be situations hi which two expanded service areas would overlap. Accordingly, we
adopted a limited exception to the 56.33 km (35 mile) protected service area definition to govern
modification applications of MDS incumbents, where two protected service areas overlap. See
Second Wireless Cable Reconsideration Order, 10 FCC Red at 7083-84. In such cases, applicants
are allowed to request waiver of the protection criteria in Section 21.902 of the Commission's
Rules. The waiver submission must demonstrate that the facilities proposed hi the modification
application will not increase the size of the geographic area predicted to receive interference, nor
be predicted to cause harmful interference to any new portion of the other station's protected
area.
24. Consistent with use of our existing interference criteria, the limited exception
described in para, 23, supra, will also apply to modification applications of MDS incumbents
seeking use of digital technology. We note that the same physical situation will be encountered
by "ITFS incumbents" whose facilities were either authorized or proposed on or before September
18,1995. The vast majority of these licensees are part of wireless cable systems, having identical
facilities to those of the MDS licensees in the same systems
ification applications of MDS incumbents
seeking use of digital technology. We note that the same physical situation will be encountered
by "ITFS incumbents" whose facilities were either authorized or proposed on or before September
18,1995. The vast majority of these licensees are part of wireless cable systems, having identical
facilities to those of the MDS licensees in the same systems. Therefore, in order to facilitate the
introduction of digital technology on all of the channels hi a wireless cable system, during the
45 A sensitivity analysis was performed on the proposed spectral mask. This analysis demonstrated that the
proposed mask provides more protection than the current analog mask. See Interference Testing Report at 27-34.
18853
Federal Communications Commission FCC 96-304
interim period, ITFS incumbent licensees applying for digital authority may, when applicable,
request waiver of the interference criteria in Section 74.903 of the Commission's Rules based on
the limited exception described above. This will further our goal of "enhancing the compatibility
for the wireless cable operator who uses ITFS and MDS channels." Second Wireless Cable
Reconsideration Order, 10 FCC Red at 7079. This matter will be revisited in a future rulemaking
proceeding on use of digital technology in the MDS and ITFS services.
25. We are also persuaded by Petitioners' arguments for interim waiver of the emissions
limitations of Sections 21.908(b) and 74.936(b). When we considered the MDS and ITFS
spectral mask in 1990, we originally proposed a constant slope attenuation from the emission
level at the channel edges to 60 dB attenuation at 3 MHz above the upper and below the lower
channel edge,46 and Petitioners essentially reiterate that proposal here. While we eventually
adopted the more restrictive current spectral mask,47 we did so, as Petitioners point out,4* based
on tests utilizing NTSC analog transmissions
nally proposed a constant slope attenuation from the emission
level at the channel edges to 60 dB attenuation at 3 MHz above the upper and below the lower
channel edge,46 and Petitioners essentially reiterate that proposal here. While we eventually
adopted the more restrictive current spectral mask,47 we did so, as Petitioners point out,4* based
on tests utilizing NTSC analog transmissions. We find, based on the digital test results submitted
by Petitioners, that we may allow Petitioners' proposed spectral mask as an interim measure
without sacrificing adjacent channel interference protection. Acceptable levels of out-of-band
emissions shall reference the average transmitter output power. See para. 27 and note 54, infra.
We also clarify that the relative power of out-of-band emissions shall be measured with 100 kHz
resolution bandwidth. As we have recently articulated, "[t]o maximize spectrum efficiency . . .
the shape of the emission mask [must] be designed to permit reasonable and practical information
transfer without excessively expensive filtering requirements. At the same time, out-of-band
emission limits must be judiciously selected to provide acceptable adjacent channel protection."
Replacement of Part 90 by Part 88 to Revise the Private Land Mobile Radio Services and Modify
the Policies Governing Them and Examination of Exclusivity and Frequency Assignment Policies
of the Private Land Mobile Radio Services, 10 FCC Red 10076, 10117 (1995).49 Petitioners'
proposed interim spectral mask will facilitate the swift, low-cost introduction of digital technology
to wireless cable, by allowing the use of existing transmission equipment without the significant
44 See Amendment of Parts 21, 43, 74, 78, and 94 of the Commission's Rules, Pertaining to Rules Governing
Use of the Frequencies in the 2.1 and 2.5 GHz Bands Affecting: Private Operational-Fixed Microwave Service,
Multipoint Distribution Service, Multichannel Multipoint Distribution Service, Instructional Television Fixe
owing the use of existing transmission equipment without the significant
44 See Amendment of Parts 21, 43, 74, 78, and 94 of the Commission's Rules, Pertaining to Rules Governing
Use of the Frequencies in the 2.1 and 2.5 GHz Bands Affecting: Private Operational-Fixed Microwave Service,
Multipoint Distribution Service, Multichannel Multipoint Distribution Service, Instructional Television Fixed Service,
and Cable Television Relay Service, Notice of Proposed Rule Making and Notice of Inquiry, 5 FCC Red 971, 977
(1990) (hereinafter Wireless Cable NPRM).
47 See Wireless Cable Order, 5 FCC Red al 6421.
48 See Petition at 27.
49 In the Private Land Mobile Radio Services order, we approved a less restrictive spectral mask where, as
here, it provided acceptable adjacent channel interference protection. Our decision also rested on our finding that
"[e]xisting equipment would require redesign and the necessary modifications would not only be expensive but would
delay the use of 12.5 kHz bandwidth equipment in the marketplace." Id. at 10119.
18854
Federal Communications Commission FCC 96-304
costs and delays associated with equipment upgrades. In this manner, the public interest is
fulfilled, while at the same time, adequate adjacent channel interference protection is provided.
3. Digital Power and Related Considerations
26. A major difference between analog and digital transmission systems is the measure
used to describe the transmitted power. For NTSC analog signals, the chosen measure is the
envelope power at the peak of the synchronizing pulses of the television video signal ("peak
visual power"), which does not change appreciably during the course of normal station operations.
NTSC peak visual power is commonly thought of as a transmitter parameter; however, it also
determines the power radiated from a transmitting antenna, one measure of which is the effective
isotropically radiated power ("EIRP"). Digital signals based on VSB or QAM modulation are
different from NTSC signals
r"), which does not change appreciably during the course of normal station operations.
NTSC peak visual power is commonly thought of as a transmitter parameter; however, it also
determines the power radiated from a transmitting antenna, one measure of which is the effective
isotropically radiated power ("EIRP"). Digital signals based on VSB or QAM modulation are
different from NTSC signals. Except for a pilot carrier frequency in the VSB format,50 the digital
signal waveform resembles random electrical noise, with many closely spaced irregular peaks at
different levels evenly distributed above and below some average value, a value generally not
affected by the modulating video signal. Therefore, digital signals are normally characterized by
the "average" power in a 6 MHz digital channel, and calculations and/or measurements are made
of average transmitter power, average EIRP, and average signal strength. In MDS and ITFS
interference studies, a station's EIRP is entered into the free space propagation formula to predict
levels of desired and undesired signal strengths, which in turn comprise the D/U interference
protection ratios. The interim D/U protection ratios proposed by Petitioners are based on
measurements of the peak NTSC visual power of the "desired" analog signal and the average
power of the "undesired" digital signal, an established practice according to Petitioners:
This results in comparing "apples and oranges.' So long as the measurements are
always made in the same way and the degree of acceptable interference is
established using corresponding values, this is not a problem. Thus acceptable
interference from digital-into-analog or from analog-into-digital is expressed in
decibels based upon the peak of one and the average of the other. This is the
industry norm for describing such relationships.
Interim Implementation-Report at 2
ys made in the same way and the degree of acceptable interference is
established using corresponding values, this is not a problem. Thus acceptable
interference from digital-into-analog or from analog-into-digital is expressed in
decibels based upon the peak of one and the average of the other. This is the
industry norm for describing such relationships.
Interim Implementation-Report at 2. Accordingly, Petitioners ask the Commission to clarify that
all digital power measurements and values in the MDS and ITFS services be defined as average
power levels. Petition at 20 n.32.
27. We agree that average power, as described above, is a suitable measure for digital
transmissions, and is the most suitable for purposes of this interim ruling, in that it was a
measured variable in the testing in support of the Petitioner's interference protection proposals.
50 See paras. 30 and 32, infra.
18855
Federal Communications Commission FCC 96-304
Thus, we determine here that interim digital authorizations for MDS and ITFS stations will
specify average values for EIRP, and that emissions in the spectral mask will reference the
average power51 in a 6 MHz bandwidth measured at the output of the digital transmitter.
Moreover, for purposes of this ruling, all other relevant signal propagation measures and
parameters for digitally transmitted signals will reflect the use of average power; e.g., power flux
density, received power, and electric field strength. As suggested in the Interim Implementation
Report,52 we will authorize digital transmissions with an average power level (EIRP) equal to the
peak visual power (EIRP) of analog transmissions from the same facility. Generally, applicants
may seek an EIRP for their digital facilities up to the EIRP limits now permitted in our rules for
analog transmissions
power, and electric field strength. As suggested in the Interim Implementation
Report,52 we will authorize digital transmissions with an average power level (EIRP) equal to the
peak visual power (EIRP) of analog transmissions from the same facility. Generally, applicants
may seek an EIRP for their digital facilities up to the EIRP limits now permitted in our rules for
analog transmissions. An MDS or ITFS applicant proposing to use an omni-directional
transmitting antenna may request authority to operate digitally with an EIRP (average) of up to
2,000 watts, based on compliance with the interim standards and procedures for interference
protection, spectral mask, and spectral energy dispersion. See para, 30, infra. This policy will
facilitate the use of existing equipment (e.g., portions of an analog transmitter) and the rapid
introduction of digital wireless cable systems into the competitive marketplace.
28. As a practical matter, in order to control the undesired effects of large amplitude
peaks in a digital signal, "it will be necessary to 'back off the power output by as much as 6-7
dB (to a level of 20-25 per cent of the rated analog power output)." Interim Implementation
Report at 14. According to Petitioners, some stations may find it necessary to temporarily
operate with reduced power until they begin to operate with fully digital transmitters; thus,
Petitioners request that the Commission permit licensees to operate at less than authorized power
during the interim period. Section 21.107(c) provides that transmitter power must be maintained
"as near as practicable" to the power specified hi the station authorization, and Section 74.95 l(f)
states that a formal application is required for a change in operating power. 47 C.F.R.
�� 21.107(c) and 74.591(f). Petitioners explain that a licensee may need to operate at reduced
power: (1) to eliminate distortion otherwise caused by irregular power peaks in the digital signal;
tained
"as near as practicable" to the power specified hi the station authorization, and Section 74.95 l(f)
states that a formal application is required for a change in operating power. 47 C.F.R.
�� 21.107(c) and 74.591(f). Petitioners explain that a licensee may need to operate at reduced
power: (1) to eliminate distortion otherwise caused by irregular power peaks in the digital signal;
(2) to achieve the required 45 dB D/U protection ratio with respect to a closely-spaced station
that had been licensed through consent or through the use of frequency offset techniques;53 or (3)
because its existing transmitter equipment is incapable of meeting even the relaxed limitations
51 See para. 25, supra.
52 Interim Implementation Report at 14.
53 Frequency offset is a deviation in frequency from the nominal position of a carrier frequency in a given
channel. This deviation makes the two signals with certain differences in frequencies less susceptible to interference
from each other. Petitioners contend that frequency offset techniques are of no utility in reducing interference caused
by a station utilizing digital modulation, because the digital signal is spread uniformly across the channel bandwidth.
Therefore, Petitioners Tnaintain that absent successful coordination among the affected parties, a station now providing
less than 45 dB D/U cochannel interference protection must reduce power in order to convert to use of digital
technology. Petition at 29 n.53. See paras. 33-34, infra.
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Federal Communications Commission FCC 96-304
on out-of-band emissions proposed by Petitioners. Petition at 28-29. Generally permitting
licensees converting to digital technology to operate at reduced power on an interim basis will,
Petitioners assert, avert a flood of individual requests for special temporary authority. This, hi
turn, will add an element of certainty, reduce Commission staff workload, and expedite the
deployment of digital technology hi the wireless cable industry
. Petition at 28-29. Generally permitting
licensees converting to digital technology to operate at reduced power on an interim basis will,
Petitioners assert, avert a flood of individual requests for special temporary authority. This, hi
turn, will add an element of certainty, reduce Commission staff workload, and expedite the
deployment of digital technology hi the wireless cable industry. Petition at 30.
29. We are persuaded by Petitioners' justification of their request for operation at reduced
power by licensees employing digital modulation during this interim period. We note that our
rules- contemplate operation at reduced power where necessary to avoid harmful interference. See,
e.g., 47 C.F.R. � 74.903(a) ("Interference may also be controlled through ... use of the
minimum power required to provide the needed service."). See also Second Wireless Cable
Reconsideration Order, 10 FCC Red at 7084 ("There are a number of engineering techniques
which can be used [by an MDS applicant], singularly or in combination, to avoid or eliminate
the potential for harmful interference. Examples of such techniques include . . . decrease of
transmitter power . . . ."). Interpreting Sections 21.107(c) and 74.951(f) to the extent of
permitting, without application to the Commission, operation at less than authorized power will
expedite introduction of digital technology hi the wireless cable industry, as described by
Petitioners. Although MDS licensees may operate with reduced power without notifying the
Commission, licensees are cautioned that interference protection will be based on the authorized
EIRP.
30. While we agree with the specification of average power for digital transmissions, we
are concerned that the power spectrum of digital signals be properly shaped to produce an
average power that is meaningful for controlling interference; i.e., that the power spectral density
be uniform across the digital channel
tioned that interference protection will be based on the authorized
EIRP.
30. While we agree with the specification of average power for digital transmissions, we
are concerned that the power spectrum of digital signals be properly shaped to produce an
average power that is meaningful for controlling interference; i.e., that the power spectral density
be uniform across the digital channel. To achieve this uniformity, the digital signal input must
be suitably randomized before being modulated, hi order to avoid "symbol patterns" (clustering
of high energy symbols) that cause significant power peaks hi the digital spectral waveform,
which hi turn increases the potential for cochannel interference. Accordingly, we believe it is
necessary to stipulate interim measures for ensuring that adequate energy dispersal will be
provided at all times for digitally modulated signals, including times when no data (input signal)
is applied to the transmitter. The means of energy dispersal shall insure substantially uniform
power spectral density across the occupied bandwidth (within the 3 dB power points) of the
signal, except for the spectral region of any system pilot carrier used, when averaged over both
relatively long and short periods. Such energy dispersal may be accomplished through the use
of data randomization by scrambling the digital signal input with a pseudo random binary
sequence ("PRBS") generated from a polynomial randomizer. Other methods of energy dispersal
are possible. However, no segment of the bandwidth of the transmitter output signal, other than
18857
Federal Communications Commission FCC 96-304
at the pilot frequency, shall be above the energy level expected for uniform dispersal.54 When
transmitting a VSB signal, a small in-phase pilot carrier may be added to the data signal. As
another safeguard against interference, we stipulate that the level of the pilot carrier be at least
11.3 dB below the average signal power
other than
18857
Federal Communications Commission FCC 96-304
at the pilot frequency, shall be above the energy level expected for uniform dispersal.54 When
transmitting a VSB signal, a small in-phase pilot carrier may be added to the data signal. As
another safeguard against interference, we stipulate that the level of the pilot carrier be at least
11.3 dB below the average signal power. We believe that these additional measures are necessary
during the interim period covered by this ruling; particularly, in view of our permitted use of
transmission equipment that has not been type accepted for digital operation.55 In this regard, we
will require licensees of stations that will operate transmitters not type accepted for digital use
to test the in-channel power dispersal, pilot carrier level and level of out-of-band emissions, and
certify compliance with the above provisions. Testing of the power dispersion at the output of
such transmitters shall be made both with and without the presence of a digital input signal to
the transmitter. A statement certifying compliance with the above provisions, accompanying the
licensee's certification or notification to the Commission that construction of the station has been
completed, will be a necessary condition for obtaining digital operating authority. See para. 41,
infra.
4. Use of Frequency Offset Techniques and Frequency Tolerance
31. With respect to frequency tolerance, Petitioners state that 47 C.F.R. ��21.101 and
74.961 can and should continue to apply, but that for some types of digital signals, there is no
carrier frequency to measure. Petition at 33
pleted, will be a necessary condition for obtaining digital operating authority. See para. 41,
infra.
4. Use of Frequency Offset Techniques and Frequency Tolerance
31. With respect to frequency tolerance, Petitioners state that 47 C.F.R. ��21.101 and
74.961 can and should continue to apply, but that for some types of digital signals, there is no
carrier frequency to measure. Petition at 33. Petitioners additionally maintain that frequency
offset techniques are of no utility in reducing interference caused by a station employing digital
modulation.56 Petitioners cite our recent acknowledgement that:
We are especially concerned about the imminent transition from analog to digital
transmissions for MDS stations and the effect of frequency offset transmitters on
that transition. . . . [I]t is possible that our authorization of an involuntary
frequency offset may frustrate the subsequent conversion of [a] particular MDS
station to digital compression technology. This is not a desirable result.
Second Wireless Cable Reconsideration Order, 10 FCC Red at 7093; see Petition at 29 n.53.
Thus, Petitioners request that the Commission "reiterate" that it will not mandate frequency offset
54 The expected power level for any segment of a uniformly dispersed signal is expressed as 10 log,0
(frequency segment in kHz / frequency pass-band in kHz) dB below the power level for the total signal. For
licensees using existing equipment modified for digital transmissions, see para. 40, infra, the average digital
transmitter output power will be considered to be the rated peak visual output power of the analog transmitter. In
the case of a new digital transmitter design, the average digital transmitter output power will be the manufacturer's
rated power.
55 See paras. 39-41, infra.
56 See note 53, supra
existing equipment modified for digital transmissions, see para. 40, infra, the average digital
transmitter output power will be considered to be the rated peak visual output power of the analog transmitter. In
the case of a new digital transmitter design, the average digital transmitter output power will be the manufacturer's
rated power.
55 See paras. 39-41, infra.
56 See note 53, supra.
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Federal Communications Commission FCC 96-304
operations for stations utilizing digital modulation, despite the provisions of Sections 21.905(c)
and 74.96l(c) of the Commission's Rules that MDS or ITFS licensees may be required to use
frequency offset to avoid or minimize interference. Petition at 29 n.53.
32. We concur that frequency tolerance is not relevant to the digital modulation systems
involved herein, with the exception of the pilot carrier frequency in VSB systems. Testing of the
8-VSB modulation in connection with our advanced digital television proceeding has discovered
that the "beating" of the pilot carrier and visual carrier frequency of a lower adjacent NTSC
channel can introduce interference in the adjacent NTSC channel. This effect can be mitigated
by precisely controlling the difference (offset) between the two frequencies. Accordingly, we
believe that there may be some utility in frequency offset operation involving VSB digital
transmissions. However, in this ruling, we will not mandate either a frequency offset or a
tolerance for the 8-VSB pilot carrier. In view of the nature of the collocated adjacent channel
stations that comprise wireless cable systems, this is a matter best left for now to the control of
system operators
lieve that there may be some utility in frequency offset operation involving VSB digital
transmissions. However, in this ruling, we will not mandate either a frequency offset or a
tolerance for the 8-VSB pilot carrier. In view of the nature of the collocated adjacent channel
stations that comprise wireless cable systems, this is a matter best left for now to the control of
system operators. Thus, also keeping in mind our pronounced concerns that involuntary
frequency offset may in fact frustrate the ability of an MDS or ITFS station to convert to digital
transmissions, we grant, on an interim basis, Petitioners' request that we not mandate frequency
offset operations for stations utilizing digital modulation,57 subject to the outcome of any future
rulemaking proceeding. See Second Wireless Cable Reconsideration Order, 10 FCC Red at 7093.
Nonetheless, we encourage the inclusion of pilot carrier offset studies in the additional program
of testing to be conducted by those in the wireless cable industry, looking toward the adoption
of permanent rules for digital systems.
5. Responsibility and Procedures for Alleviating Potential and Actual Interference
33. While Hammett generally supports the Petition, it raises as an issue Petitioners'
treatment of existing wireless cable stations that have engineered their systems, on the basis of
frequency offsets, to allow cochannel D/U signal ratios of less than the 45 dB which is required
for nonoffset operation. Specifically, Hammett is concerned about the statement that "a station
that provides less than 45 dB D/U to a co-channel station will have to reduce power in order to
convert to digital technology, absent successful coordination." Petition at 29 n.53. Hammett
requests that Petitioners clarify which station, the analog station or the station electing to switch
to digital modulation, would be the candidate for a power reduction. See Hammett Comments
at 2
tion
that provides less than 45 dB D/U to a co-channel station will have to reduce power in order to
convert to digital technology, absent successful coordination." Petition at 29 n.53. Hammett
requests that Petitioners clarify which station, the analog station or the station electing to switch
to digital modulation, would be the candidate for a power reduction. See Hammett Comments
at 2. Moreover, in a case where two cochannel analog stations have engineered their systems to
less than 45 dB D/U ratios through frequency offsets and both wish to convert to digital
operations, mutual reductions hi power would not be helpful, because that would leave the D/U
57 We note, however, that by requesting that we "reiterate" that we will not mandate use of frequency offset
by such stations, Petitioners may have misinterpreted our recent statements regarding mandatory frequency offset.
We stated that we will continue to evaluate involuntary MDS frequency offset proposals for analog transmissions
on a case by case basis. See Second Wireless Cable Reconsideration Order, 10 FCC Red at 7093 n.14.
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Federal Communications Commission FCC 96-304
ratio unchanged. Hammett again questions which station should be the one to reduce power, and
states that apparently, "the only solution in such cases would be for each licensee to give up half
of its channels, so that the remaining channels can be afforded D/U ratios of 45 dB or better."
Hammett Comments at 2-3. Assuming these two interference concerns can be adequately
addressed, Hammett fully supports the Petition.
34. In their reply, Petitioners indicate that the language referenced by Hammett is not
intended to force a station that is remaining analog to reduce power. Reply at 4-5
s channels, so that the remaining channels can be afforded D/U ratios of 45 dB or better."
Hammett Comments at 2-3. Assuming these two interference concerns can be adequately
addressed, Hammett fully supports the Petition.
34. In their reply, Petitioners indicate that the language referenced by Hammett is not
intended to force a station that is remaining analog to reduce power. Reply at 4-5. Instead, they
affirm that under their proposed interim standards, "it is the station that desires to convert to
digital technology that will have to reduce power to provide a 45 dB D/U [ratio] to the existing
analog facility, absent agreement among the parties." Id. at 5. In response to Hammett's second
situation where two closely-spaced stations both wish to convert to digital operations, Petitioners
state that Hammett's solution is one possible approach, but suggest that "the parties could also
logically agree to convert to digital technology in tandem and retain their existing power levels."
Id. Petitioners also maintain that the Commission should permit licensees to mutually agree to
convert to digital technology, even if the 45 dB D/U standard cannot be met. Id. at 6.5* As
acknowledged by Petitioners, in the absence of an agreement between the parties in such
situations, resolution of the issue would depend upon the final digital-to-digital interference
protection standards to be developed hi a future rulemaking proceeding. Although Petitioners
believe that "closely-spaced digital systems will be able to operate with D/U ratios below 45 dB
and still provide subscribers with signal quality no worse than that afforded in an analog
environment under the 45 dB D/U standard," Petitioners reiterate that further testing, at higher
modulation densities, will be required before the Commission can adopt the final interference
protection standards. Id. at 5-6.
35
aced digital systems will be able to operate with D/U ratios below 45 dB
and still provide subscribers with signal quality no worse than that afforded in an analog
environment under the 45 dB D/U standard," Petitioners reiterate that further testing, at higher
modulation densities, will be required before the Commission can adopt the final interference
protection standards. Id. at 5-6.
35. Similar to Hammett, Tarrant County generally supports the Petition, but it urges the
Commission to establish a mechanism to ensure that ITFS and MDS licensees are protected from
actual interference caused by digital transmissions. Tarrant County asserts that where actual
interference occurs, the digital operator must be required to remove the interference immediately,
at its own cost. See Tarrant County Comments at 2-3. In its reply, Petitioners contend that the
Commission should apply its current policies regarding actual interference to ITFS and MDS
signals, whether the interfering signal is from analog or digital transmissions, because digital
transmissions are no more likely to cause harmful interference than analog transmissions.
Petitioners add that Tarrant County has given no reason to believe that the Commission's current
policies in this regard are inadequate. See Reply at 7 n.14.
58 Cf. Section 21.937 of the Commission's Rules (providing in pertinent part that n[t]he level of acceptable
electromagnetic interference that occurs . . . can be negotiated and established by an agreement between the
appropriate parties," if the parties to the agreement file with die Commission a statement of no objection to the lesser
level of interference protection). MDS Auction Order, 10 FCC Red at 9695-96.
18860
Federal Communications Commission FCC 96-304
36. We believe that our current rules provide adequate mechanisms to deal with the
potential for harmful interference, as well as actual interference
priate parties," if the parties to the agreement file with die Commission a statement of no objection to the lesser
level of interference protection). MDS Auction Order, 10 FCC Red at 9695-96.
18860
Federal Communications Commission FCC 96-304
36. We believe that our current rules provide adequate mechanisms to deal with the
potential for harmful interference, as well as actual interference. Section 21.902 of the
Commission's Rules provides that MDS applicants, conditional licensees and licensees are
expected to "cooperate fully" in attempting to resolve problems of potential interference before
bringing them to the attention of the Commission, and are required to "[c]ooperate fully and hi
good faith" to resolve interference problems. 47 C.F.R. � 21.902(a) and (b)(2).59 Section 74.903
likewise provides that existing licensees and prospective applicants are expected to "cooperate
fully" in attempting to resolve problems of potential interference before bringing them to the
attention of the Commission. 47 C.F.R. � 74.903(c); see 47 C.F.R. � 74.903(d) and (e). As
Petitioners articulate, "given the paucity of complaints of actual interference that the Commission
has been called upon to resolve over the years, it appears that the existing policies work well."
Reply at 7 n.14. In addition, we have declared with respect to MDS stations and ITFS facilities
being leased or used for non-ITFS purposes, that if a station causes harmful interference within
the protected service area of another existing station and the interference is not de minimis, "we
will require the offending station to cease operations until the interference is eradicated
k well."
Reply at 7 n.14. In addition, we have declared with respect to MDS stations and ITFS facilities
being leased or used for non-ITFS purposes, that if a station causes harmful interference within
the protected service area of another existing station and the interference is not de minimis, "we
will require the offending station to cease operations until the interference is eradicated. The
station alleging that it is being interfered with will be required to make a clear and convincing
showing that the interference is occurring." Amendment of Parts 21, 74 and 94 of the
Commission's Rules and Regulations with regard to the technical requirements applicable to the
Multipoint Distribution Service, the Instructional Fixed Television Service and the Private
Operational-Fixed Microwave Service (OFS), 98 FCC 2d 68, 93 (1984). See id. at 92-93.
37. Thus, we find that Petitioners present satisfactory approaches for resolving Hammett's
first concern and those concerns expressed by Tarrant County. As for the situation where two
closely-spaced stations, which operate on the basis of frequency offset, both seek to convert to
digital operations, Hammett and Petitioners have proposed three solutions involving agreement
between the two parties. We believe, in the interest of fostering a clear, market-based solution,
that for the interim period governed by this ruling, any conflict resulting from this type of
situation must be resolved by agreement between the two parties, or we will grant neither party
the authority to modify its operations to employ digital technology. This approach will maintain
an environment free of harmful interference until we have the opportunity to adopt the final
59 Newly-adopted Section 21.938(a) of the Commission's Rules similarly provides that Basic Trading Area
(BTA) or partitioned service area (PSA) authorization holders "are expected to cooperate with one another" to protect
service in adjoining BTAs and PSAs. See MDS Auction Order, 10 FCC Red at 9696
an environment free of harmful interference until we have the opportunity to adopt the final
59 Newly-adopted Section 21.938(a) of the Commission's Rules similarly provides that Basic Trading Area
(BTA) or partitioned service area (PSA) authorization holders "are expected to cooperate with one another" to protect
service in adjoining BTAs and PSAs. See MDS Auction Order, 10 FCC Red at 9696. The newly-adopted MDS rules
also contain specific provisions for cure of actual interference. For instance, Section 21.938(d) provides that it is
the responsibility of a BTA or PSA authorization holder "to correct at its expense any condition of harmful
electromagnetic interference caused to authorized MDS service at locations within other BTAs or PSAs or within
the ... protected service areas of authorized or previously proposed ITFS and MDS stations (incumbents), or at
authorized or previously proposed ITFS receive sites." MDS Auction Reconsideration Order, 10 FCC Red at 13839.
Section 21.939 also provides that Commission staff may require an MDS conditional licensee or licensee to employ
any one of several enumerated interference abatement techniques, in the event "harmful interference occurs or appears
to occur." MDS Auction Order, 10 FCC Red at 9697.
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Federal Communications Commission FCC 96-304
interference protection standards applicable to the use of digital technology in the MDS and ITFS
services.
D. Application of Other MDS and ITFS Technical Rules in a Digital Environment
38. Petitioners argue that while there is flexibility in our current rules for authorization
of the use of digital technology,60 the rules nevertheless remain focused on NTSC transmissions,
and there are instances where the use of digital technology does not comport with these rules
in the MDS and ITFS
services.
D. Application of Other MDS and ITFS Technical Rules in a Digital Environment
38. Petitioners argue that while there is flexibility in our current rules for authorization
of the use of digital technology,60 the rules nevertheless remain focused on NTSC transmissions,
and there are instances where the use of digital technology does not comport with these rules.
Consequently, Petitioners maintain that the Commission should clarify how it will apply certain
of these rules in the digital environment, and permit "deviations" from any rules designed solely
to address NTSC issues, which are "inherently unsuitable for application to the use of digital
technology." Petition at 30.
1. Equipment Approval
39. Petitioners request that the Commission provide manufacturers an opportunity to
secure type acceptance for digital transmitters that comply with the relaxed out-of-band emissions
limitations proposed by Petitioners. They also request that manufacturers be offered the option
of obtaining digital type acceptance for "earlier designs that are already installed in analog
systems," but where a manufacturer does not do so, the Commission should afford the affected
MDS or ITFS licensee a vehicle for utilizing its existing transmitters, without meeting the type
acceptance requirement under 47 C.F.R. � 21.907(c). Petition at 32. Petitioners propose that rne
Commission allow use of existing analog transmitters adapted for digital transmission, but that
have not received digital type acceptance, to operate at reduced power and/or with appropriate
filtering, if necessary, in order to comply with the interim spectral mask sought by Petitioners.61
Petitioners further suggest that absent type acceptance, the licensee should be required to submit
a "proof-of-performance at the time of construction" of the digital system, demonstrating
compliance with the interim spectral mask. Petition at 32-33.
40
reduced power and/or with appropriate
filtering, if necessary, in order to comply with the interim spectral mask sought by Petitioners.61
Petitioners further suggest that absent type acceptance, the licensee should be required to submit
a "proof-of-performance at the time of construction" of the digital system, demonstrating
compliance with the interim spectral mask. Petition at 32-33.
40. Parts 21 and 74 of the Commission's Rules require that all MDS and ITFS
transmitters be type accepted. See 47 C.F.R. �� 21.120, 21.907(c), 74.938 and 74.952. For
manufacturers who- seek to secure digital type acceptance for newly-designed or modified
transmitters that comply with the interim spectral mask approved above, upon an appropriate
showing the Commission will grant type acceptance based on the conditions of waiver described
in this ruling. See 47 C.F.R. � 2.915(a) and (b). We intend to reevaluate digital type acceptance
issues in a future rulemaking proceeding on digital modulation for the MDS and ITFS services.
At the present time, given the public and industry interest in expediting the employment of digital
60 See paras. 9-11, supra.
61 See paras. 28-29, supra.
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Federal Communications Commission FCC 96-304
technology, notwithstanding the type acceptance requirements in Parts 21 and 74, we also will
allow MDS and ITFS licensees to use existing analog equipment modified for digital
transmissions that comply with the interim spectral mask approved above, without obtaining
digital type acceptance, subject to certain conditions incorporating Petitioners' "proof-of-
performance" proposal. Approval of the use of newly-designed digital transmitting equipment
will still be subject to type acceptance procedures pursuant to Parts 2, 21 and 74 of the
Commission's Rules.
41
transmissions that comply with the interim spectral mask approved above, without obtaining
digital type acceptance, subject to certain conditions incorporating Petitioners' "proof-of-
performance" proposal. Approval of the use of newly-designed digital transmitting equipment
will still be subject to type acceptance procedures pursuant to Parts 2, 21 and 74 of the
Commission's Rules.
41. Under this scheme, after the Commission staff grants a licensee's application to
employ digital technology, the licensee will incorporate a digital component (e.g., modulator or
exciter) into its existing base of transmission equipment, and perform on-site tests (measurements)
at the transmitter output to determine compliance with the interim spectral mask, as well as power
level and energy dispersal strictures discussed above. See paras. 21, 25 and 27-30, supra. The
licensee may rely on tests performed by the equipment manufacturer or by a test laboratory
confirming compliance with the interim spectral mask for a specific combination of digital
modulator and amplifiers. The licensee will then certify to the Commission, at the time it
certifies or notifies the Commission that construction of the station has been completed,62 that
these tests have been performed, the transmissions meet the interim spectral mask, the maximum
EIRP of its facility does not exceed the authorized EIRP, and the transmissions comply with the
spectral energy dispersal requirements. Test results must be furnished to the Commission upon
request. Thus, in furtherance only of the scheme delineated herein, we waive the requirements,
contained hi Subpart J of Part 2 of the Commission's Rules,63 pertaining to issuance of equipment
authorizations prior to operation, though we will allow manufacturers to seek type acceptance of
existing analog equipment modified for digital transmissions under the technical guidelines
described above in this ruling
rtherance only of the scheme delineated herein, we waive the requirements,
contained hi Subpart J of Part 2 of the Commission's Rules,63 pertaining to issuance of equipment
authorizations prior to operation, though we will allow manufacturers to seek type acceptance of
existing analog equipment modified for digital transmissions under the technical guidelines
described above in this ruling. Furthermore, any other rules in Parts 2, 21 and 74 containing
requirements for type acceptance and applicable to analog MDS or ITFS transmissions are waived
for existing analog equipment modified for digital transmissions. These waivers, as well as the
testing and statement-of-perfonnance process set forth above and additionally described below,
will be effective until final rules are adopted in the future.
2. Emission Designators
42. Petitioners state that MDS and ITFS stations using digital modulation "will Likely
employ" emission designators of 6MOOD7W for QAM and 6MOOC7W for VSB. Petition at 13
n.23. ITS believes that both applicants and equipment manufacturers who must seek type
acceptance of transmitting equipment would benefit from standardized emission designators, and
posits that 6MOOD1W for QAM and 6MOOC1W for VSB may be more accurate. ITS suggests
62 See para. 54, infra, for a specific description of these procedures.
63 47C.F.R. ��2.901 et seq.
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Federal Communications Commission FCC 96-304
that a "1," signifying a single channel of digital information, would be more correct than a "7,"
which is generally reserved for multiple channels of unrelated digital information
or QAM and 6MOOC1W for VSB may be more accurate. ITS suggests
62 See para. 54, infra, for a specific description of these procedures.
63 47C.F.R. ��2.901 et seq.
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Federal Communications Commission FCC 96-304
that a "1," signifying a single channel of digital information, would be more correct than a "7,"
which is generally reserved for multiple channels of unrelated digital information. ITS Comments
at 1-2.64 In its reply, Petitioners agree with ITS that it would be beneficial for the Commission
to clarify its policy regarding emission designators and to apply that policy uniformly.65
However, Petitioners contend that the issue of which emission designator is appropriate to QAM
and VSB systems has no bearing on the issues addressed in the Petition, and that the results of
the testing conducted for the Petition and the conclusions from that testing remain valid. See
Reply at 3-4.
43. We agree with ITS and Petitioners that standardization of emission designators would
be beneficial in eliminating confusion. Emission designators are governed by Section 2.201 of
the Commission's Rules, 47 C.F.R. � 2.201. Section 2.20l(d) provides that use of a "1," as
suggested by ITS, indicates that the signal modulating the carrier is a "single channel containing
quantized or digital information without the use of a modulating sub-carrier, excluding time-
division multiplex." 47 C.F.R. � 2.201 (d) (emphasis added). We envision that the modulating
signal will contain a time division multiplex of video, audio, and data signals from two or more
sources. Therefore, the more appropriate emission designators are 6MOOD7W for QAM and
6MOOC7W for VSB. Where necessary, applications may be amended to change the emission
designator to bring it into confonnance with those specified herein, and we will treat these
changes as minor amendments. See paras. 55-57, infra.
3. Transmission standards
44. Petitioners request that despite the mandates of 47 C.F.R
efore, the more appropriate emission designators are 6MOOD7W for QAM and
6MOOC7W for VSB. Where necessary, applications may be amended to change the emission
designator to bring it into confonnance with those specified herein, and we will treat these
changes as minor amendments. See paras. 55-57, infra.
3. Transmission standards
44. Petitioners request that despite the mandates of 47 C.F.R. � 21.907 that all MDS
licensees equip their facilities for NTSC transmission capability, the Commission not require
MDS licensees to offer NTSC service if the operator using the station elects and receives
authorization to transmit digitally. Petition at 31. When the Commission promulgated this rule
as part of the original rules governing MDS, NTSC transmission capability was retained as a
safeguard against other transmission standards that might prove lacking in quality. See MDS
Allocation Order, 45 FCC 2d at 624. We acknowledge that the technology upon which the
standards adopted in 1974 were based has changed substantially, and we recognize that digital
will likely be the primary transmission method for video programming for the foreseeable future.
64 ITS is one of the Petitioners and otherwise supports the Petition.
65 Petitioners note that there are several applications pending at the Commission which specify the same
emission designator as that referenced hi the Petition. If the Commission determines that a different emission
designator is proper for digital wireless cable, Petitioners request that the Commission permit amendments to those
applications. Petitioners further request that the Commission treat those amendments as minor amendments, though
emission designator changes are normally treated as major amendments under MDS rules. Petitioners reason that
there would be no actual change to the modulating signal itself and hence no threat of increased interference. See
Reply at 3-4 n.8
Commission permit amendments to those
applications. Petitioners further request that the Commission treat those amendments as minor amendments, though
emission designator changes are normally treated as major amendments under MDS rules. Petitioners reason that
there would be no actual change to the modulating signal itself and hence no threat of increased interference. See
Reply at 3-4 n.8.
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Federal Communications Commission FCC 96-304
In further recognition of the tested and proven quality of the digital modulation formats which
Petitioners seek to utilize,66 we find that waiver of Section 21.907 does not undermine the rule's
purpose. In addition, compliance with Section 21.907 for licensees who transmit digitally places
unnecessary burdens on such licensees. Cf. note 77, infra (MDS station identification
requirements removed where burdens on licensees outweighed benefits). Accordingly, we will
not require MDS licensees who utilize digital transmissions to equip their facilities for NTSC
transmission capability. Section 21.907 is hereby waived to the extent indicated in this
paragraph. For the same reasons, we also waive Section 74.950(f)(l) to the extent it requires
ITFS translators and boosters relaying digital signals to be designed so that the electrical
characteristics of an NTSC signal introduced into the input terminals will not be significantly
altered, except as to frequency and amplitude, by passage through the translator or booster. 47
C.F.R. � 74.950(f)(l).67
45
the same reasons, we also waive Section 74.950(f)(l) to the extent it requires
ITFS translators and boosters relaying digital signals to be designed so that the electrical
characteristics of an NTSC signal introduced into the input terminals will not be significantly
altered, except as to frequency and amplitude, by passage through the translator or booster. 47
C.F.R. � 74.950(f)(l).67
45. Tarrant County maintains that "for at least the near term" licensees should be
permitted to (1) flexibly employ digital operations on one or more, but not necessarily all, of their
authorized channels; (2) freely switch from analog to digital and digital to analog modulation
among channels and on the same channel; and (3) freely utilize digital technology to transmit
other modulations in addition to those advanced in the Petition, such as '"high definition'" or
"digital data broadcasting in the NTSC blanking intervals." Tarrant County Comments at 3-4.
Petitioners agree that the flexibility sought by Tarrant County is appropriate at least for the time
being, and they assert that the Petition contemplated that sort of flexibility. See Reply at 7.
However, Petitioners note that to the extent the technologies mentioned by Tarrant County do not
employ QAM or VSB, Tarrant County "should be required to demonstrate that its digital proposal
will not cause harmful electromagnetic interference to nearby stations." Id at n.15.
46. We fully support the flexibility sought by Tarrant County in its first two proposals.
Such flexibility could benefit both existing licensees and new applicants alike. However, as with
SR Telecom's request for consideration of the use of wireless loop technology on MDS
frequencies,68 no data was submitted here for evaluation of the merits of Tarrant County's third
proposal regarding transmission of other digital modulations
ought by Tarrant County in its first two proposals.
Such flexibility could benefit both existing licensees and new applicants alike. However, as with
SR Telecom's request for consideration of the use of wireless loop technology on MDS
frequencies,68 no data was submitted here for evaluation of the merits of Tarrant County's third
proposal regarding transmission of other digital modulations. Therefore, we find clarification of
the use of other digital modulation techniques beyond the scope of this ruling.69 We intend, in
66 See, e.g., Advanced Television Systems and Their Impact Upon the Existing Television Broadcast Service,
Fifth Further Notice of Proposed Rule Making in MM Docket No. 87-268, FCC 96-207 (released May 20, 1996).
67 Section 74.950(f)(l) was adopted in 1971. See Amendment of Part 74, Subpartl of the Commission's Rules
and Regulations Governing Instructional Television Fixed Stations to Provide for the Operation of Low Power Relay
Stations (Translators or Boosters), 29 FCC 2d 192, 196 (1971).
68 See para. 12, supra.
69 Our action is without prejudice to any subsequent filing by Tarrant County.
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Federal Communications Commission FCC 96-304
a future rulemaking proceeding, to approach the issue of alternative uses of MDS and ITFS
spectrum in a digital environment.
4. Equipment standards. Modulation Limits and Aural Power Limitations
47. Petitioners contend that the transmission equipment requirements imposed by 47
C.F.R. �� 21.908(a) and 74.950(a) pertaining to NTSC signal waveform and transmitter
performance characteristics are "[b]y their very nature" incompatible with digital transmissions,
and "should be inapplicable" in the digital environment. Petition at 31. Similarly, Petitioners
maintain that the Commission should not apply 47 C.F.R � 74.970 to a station utilizing digital
transmissions because the modulation parameters specified in that rule are specific to analog
transmissions. Petition at 33
ristics are "[b]y their very nature" incompatible with digital transmissions,
and "should be inapplicable" in the digital environment. Petition at 31. Similarly, Petitioners
maintain that the Commission should not apply 47 C.F.R � 74.970 to a station utilizing digital
transmissions because the modulation parameters specified in that rule are specific to analog
transmissions. Petition at 33. Petitioners likewise assert that Sections 21.904(d) and 74.935(d)
of the Commission's Rules regarding aural signal power are inapplicable hi the digital
environment, where there are no separate aural and visual carriers.70 Moreover, waiving Sections
21.904(d) and 74.935(d) when digital modulation is employed is consistent with the rules'
purpose, namely the reduction of the potential for harmful adjacent channel interference,71 because
Petitioners' proposal will result in improved adjacent channel performance.72 Petition at 34. To
the extent that Sections 21.904(d), 21.908(a), 74.935(d), 74.950(a) and 74.970 are incompatible
with digital transmissions or the provisions of this ruling, those rules are hereby waived.
5. Transmission of ITFS Call Signs
48. Section 74.982(b)-(f) requires ITFS licensees to transmit their call signs periodically.73
47 C.F.R. � 74.982(b)-(f). Petitioners argue that compliance with this rule, once an ITFS station
commences digital transmission, will be costly and will provide little, if any, public benefit.
Petitioners therefore request that until permanent rules regulating the use of digital in MDS and
ITFS are adopted, "the Commission should spare licensees the cost of compliance ... by not
applying the requirements of Sections 74.982(b)-(f) to ITFS facilities operating in a digital
mode." Petition at 35
s digital transmission, will be costly and will provide little, if any, public benefit.
Petitioners therefore request that until permanent rules regulating the use of digital in MDS and
ITFS are adopted, "the Commission should spare licensees the cost of compliance ... by not
applying the requirements of Sections 74.982(b)-(f) to ITFS facilities operating in a digital
mode." Petition at 35. In the alternative, Petitioners seek clarification of whether the
Commission intends for the call signs to be transmitted in analog format or digital format, and
if in digital format, whether such transmission must be made over one channel or all of the
channels created through use of compression. Petition at 34-35.
70 Sections 21.904(d) and 74.93 5(d) identically provide that the peak power of the aural signal may not exceed
10 percent of the peak visual power of the transmitter, and that the Commission may order a reduction in aural signal
power to diminish the potential for harmful interference. 47 C.F.R. �� 21.904(d) and 74.935(d).
71 See Wireless Cable Order, 5 FCC Red at 6421.
72 See paras. 17 and 20, supra.
73 Part 21 of the Commission's Rules does not impose a corresponding obligation on MDS licensees.
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Federal Communications Commission FCC 96-304
49. In establishing the station identification requirements of Section 74.982, the
Commission described their primary purpose as showing that the operation is licensed. FTPS
Allocation Order, 39 FCC at 860.74 The importance of showing that the station is licensed was
further explained in another context as protecting stations against accusations of wrongdoing,
because there was a "strong suspicion" that signals originated from an unlicensed transmitter
where signals were observed but call signs were not transmitted. See Amendment of Section
74.682 of the Commission's Rules and Regulations Concerning Station Identification of Television
Auxiliary Broadcast Stations, 5 FCC 2d 767, 769 (1966)
s protecting stations against accusations of wrongdoing,
because there was a "strong suspicion" that signals originated from an unlicensed transmitter
where signals were observed but call signs were not transmitted. See Amendment of Section
74.682 of the Commission's Rules and Regulations Concerning Station Identification of Television
Auxiliary Broadcast Stations, 5 FCC 2d 767, 769 (1966). In the television auxiliary broadcast
station identification order, the Commission emphasized that adequate station identification
"assurefs] proper enforcement of our rules and prompt relief from disruptive interference should
such occur." Id. at 771. Call sign transmission also keeps the public aware of a station's identity
and facilitates the reporting by members of the public of infractions, though the reporting of
infractions by the public "is not the primary purpose of station identification." Id. at 769.
50. The Commission's rules currently require public services such as ITFS, low power
TV75 and AM-FM-TV broadcast services76 - to broadcast station identifications, while private
services such as MDS77 and Private Operational-Fixed Microwave Service78 are exempt from this
requirement. Although requiring transmission of station identifications may continue to benefit
the enforcement process, it appears that such requirements create some burdens on licensees.79
In this regard, Petitioners complain about the potential costs of complying with the call sign
transmission requirement once an ITFS station commences digital transmission, and they argue
74 Section 74.982 was originally codified as Section 4.982. Id. The ITFS station identification rules remain
essentially unchanged from those originally promulgated in 1963, except for added provisions covering low power
ITFS relay stations and temporary fixed ITFS stations.
75 See 47 C.F.R. � 74.783.
76 See 47 C.F.R. � 73.1201
an ITFS station commences digital transmission, and they argue
74 Section 74.982 was originally codified as Section 4.982. Id. The ITFS station identification rules remain
essentially unchanged from those originally promulgated in 1963, except for added provisions covering low power
ITFS relay stations and temporary fixed ITFS stations.
75 See 47 C.F.R. � 74.783.
76 See 47 C.F.R. � 73.1201.
77 Call sign transmission was required for MDS stations until these station identification requirements were
removed in 1987. In so doing, we concluded that the station identification requirements, among others, "have been
a burden without corresponding benefits to licensees." Revision of Part 21 of the Commission's Rules, Report and
Order, 2 FCC Red 5713, 5727 (1987).
78 See 47 C.F.R. � 94.105. We recently consolidated the fixed microwave rules into a new Part 101, and
Section 94.105 will be recodified as Section 101213. Reorganization and Revision of Parts 1, 2, 21, and 94 of the
Rules to Establish a New Part 101 Governing Terrestrial Microwave Fixed Radio Services, Report and Order, FCC
96-51 (released February 29, 1996).
79 See note 77, supra. For instance, the justification of protecting stations from false accusations of
wrongdoing, see para. 49, supra, while well-intentioned as a protective benefit to licensees, may in reality constitute
more of a burden than a benefit.
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Federal Communications Commission FCC 96-304
that "there is no evidence that the transmission of call signs by ITFS licensees has resulted in any
better operating environment than is the case with respect to the MDS. It is a relatively simple
matter to determine any source of harmful electrical interference without reference to a call sign."
Petition at 34 n.62. In addition, keeping the public aware of a station's identity may be
particularly less important with respect to the channels that are leased to a wireless cable operator,
because the subscriber will know the identity of the wireless cable operator
s a relatively simple
matter to determine any source of harmful electrical interference without reference to a call sign."
Petition at 34 n.62. In addition, keeping the public aware of a station's identity may be
particularly less important with respect to the channels that are leased to a wireless cable operator,
because the subscriber will know the identity of the wireless cable operator.
51. Section 74.982 was last amended in 1984,80 prior to adoption of most of the rules
encouraging the use of excess ITFS spectrum for wireless cable video programming services.
The ITFS channels that are leased to wireless cable operators arguably function as private, rather
than public, services. Moreover, the burdens of requiring ITFS licensees to transmit call signs
may outweigh the benefits, especially where the channels are leased to a wireless cable operator,
whose identity is readily discernible and whose licensing status is readily ascertainable. For these
reasons, we plan to address the wisdom of continued ITFS call sign transmission requirements
in a future rulemaking proceeding. Until that time, however, we do not find a waiver of these
requirements for ITFS stations employing digital technology to be appropriate. In response to
Petitioners' alternative request that we clarify our ITFS call sign transmission requirements as
they apply to stations utilising digital technology, we will interpret Section 74.982(b),81 for the
interim period governed by this ruling, as requiring ITFS stations to transmit call signs only on
channels reserved for ITFS programming during the hours reserved for such programming.82
Until we undertake a future rulemaking on the issue, the interpretation of Section 74.982(b) set
forth herein will apply, regardless of whether the ITFS station is transmitting in analog or digital.
Furthermore, the call sign should be transmitted in the same modulation in which the ITFS
programming is transmitted. Cf. paras
TFS programming during the hours reserved for such programming.82
Until we undertake a future rulemaking on the issue, the interpretation of Section 74.982(b) set
forth herein will apply, regardless of whether the ITFS station is transmitting in analog or digital.
Furthermore, the call sign should be transmitted in the same modulation in which the ITFS
programming is transmitted. Cf. paras. 45-46, supra (authorizing ITFS and MDS licensees to
flexibly switch from analog to digital and digital to analog modulation among channels and on
the same channel).
E. Application Procedures
52. This Declaratory Ruling and Order clarifies the Commission's interim policies, rules
and procedures pertaining to MDS licensees, conditional licensees and applicants with pending
applications, as well as ITFS licensees, permittees and applicants with pending applications, who
elect to transmit a QAM or VSB digital signal. It also governs the new station applications filed
80 See ITFS Technical Order, 98 FCC 2d at 941, adding Section 74.982(f) dealing with temporary fixed ITFS
stations.
81 Section 74.982(b) provides in pertinent part that "each instructional television fixed station shall transmit
its call sign."
82 See para. 58, infra, for discussion of ITFS programming requirements.
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Federal Communications Commission FCC 96-304
by MDS auction winners or BTA authorization holders, or filed for ITFS licenses in a filing
window,83 seeking authority to transmit digitally. This ruling makes clear that each party desirous
of utilizing digital transmissions must apply for such authority by filing a formal application or
application amendment, and receive such authority from the Commission, prior to installing and
operating digital transmission equipment. A separate application or amendment must be filed for
each station for which digital authority is sought
y. This ruling makes clear that each party desirous
of utilizing digital transmissions must apply for such authority by filing a formal application or
application amendment, and receive such authority from the Commission, prior to installing and
operating digital transmission equipment. A separate application or amendment must be filed for
each station for which digital authority is sought. These applications or amendments must specify
use of either a type accepted digital transmitter or a digital transmitter to be approved through
the testing and statement-of-performance process described above. See paras. 40-41, supra. As
discussed in paras. 14-15, supra, we will grant authority to utilize such transmitters for
transmission in QAM with modulation densities up to 256 or VSB modulation with densities up
to 16. Digital signals must be transmitted on a non-interference basis, subject to meeting the
interim spectral mask and other interim technical specifications described above.
53. To assist Commission staff hi expediting the processing of these applications and
amendments, each application or amendment should include a cover letter clearly indicating that
the attached application or amendment requests authority to utilize digital transmissions. MDS
licensees, conditional licensees or applicants must file a formal application to specify digital
emissions on FCC Form 304, while ITFS licensees, permittees or applicants must do so using
FCC Form 330. Pending applications in either service must be amended to specify a digital
emission designator
the attached application or amendment requests authority to utilize digital transmissions. MDS
licensees, conditional licensees or applicants must file a formal application to specify digital
emissions on FCC Form 304, while ITFS licensees, permittees or applicants must do so using
FCC Form 330. Pending applications in either service must be amended to specify a digital
emission designator. In either case, the MDS applicant for interim digital transmission authority
must, in addition to meeting all other pertinent application requirements, prepare a new or
amended interference showing to demonstrate non-interference to others by the new or amended
application for digital operations, and serve the showing and/or copy of the application on
potentially affected parties, in accordance with Sections 21.902 and recently added 21.938(g) of
the Commission's Rules, hi the same manner that these rules relate to applications for analog
transmissions.84 MDS applicants generally are not required to include the interference studies
with their applications; nevertheless, applicants for interim digital transmission authority may
wish to submit these studies or any other information which they feel may be helpful to the
processing of their applications. While applicants for minor changes to ITFS applications or
facilities85 normally are not required to prepare or serve interference showings, we will require
during the interim period that ITFS applicants for digital authority follow the same procedures
as those that we have mandated for MDS applicants, as discussed above. We will use the same
83 See Amendment of Part 74 of the Commission's Rules With Regard to the Instructional Television Fixed
Service, 10 FCC Red 2907 (1995) (hereinafter ITFS Window Filing Order)
ence showings, we will require
during the interim period that ITFS applicants for digital authority follow the same procedures
as those that we have mandated for MDS applicants, as discussed above. We will use the same
83 See Amendment of Part 74 of the Commission's Rules With Regard to the Instructional Television Fixed
Service, 10 FCC Red 2907 (1995) (hereinafter ITFS Window Filing Order).
84 See MDS Auction Order, 10 FCC Red at 9685-88,9697; MDS Auction Reconsideration Order, 10 FCC Red
at 13838,13839; Second Wireless Cable Reconsideration Order, 10 FCC Red at 7098-99; and Third Wireless Cable
Reconsideration Order at 17.
85 See paras. 55-56, infra.
18869
Federal Communications Commission FCC 96-304
approach for MDS and ITFS applicants in light of the newness of digital operations in wireless
cable, as well as the fact that most ITFS stations are part of wireless cable systems.86 We hold
that all of the waivers in this ruling, which are granted in the public interest, are conditioned
upon applicants for interim digital authority complying with these interference showing
requirements. In lieu of an interference showing, MDS or ITFS applicants for interim digital
transmission authority may submit with their applications written statements of "no objection"
from all potentially affected licensees, conditional licensees, permittees, or applicants for
previously proposed stations, stating that these parties do not object to the digital operation of the
MDS or ITFS station, hi accordance with Sections 21.902 and 74.903 of the Commission's Rules,
as applicable.
54. Upon grant of the modified, amended or new application, a conditional licensee or
licensee who specifies use of a type accepted digital transmitter may install and test the
transmitter
y proposed stations, stating that these parties do not object to the digital operation of the
MDS or ITFS station, hi accordance with Sections 21.902 and 74.903 of the Commission's Rules,
as applicable.
54. Upon grant of the modified, amended or new application, a conditional licensee or
licensee who specifies use of a type accepted digital transmitter may install and test the
transmitter. An ITFS licensee may immediately begin to operate the transmitter upon completion
of construction, while an MDS conditional licensee may begin regular operation of the transmitter
upon proper submission of the FCC Form 304A, described below. Conditional licensees or
licensees who specify transmitters that are not type accepted for digital transmission may activate
their digital transmitters for the purpose of testing, as described in paras. 30 and 41, supra. After
installation or activation of the digital transmitter, whether type accepted or not, completion of
other necessary construction, and completion of any necessary testing, the MDS conditional
licensee will certify completion of construction on FCC Form 304A, and the ITFS licensee will
submit a letter notifying the Commission that construction has been completed.87 In conjunction
with the filing of the FCC Form 304A or the submission of the ITFS construction notification,
conditional licensees or licensees who specify a digital transmitter that is not type accepted must
also provide a statement certifying that the aforementioned tests have been performed, the
transmissions meet the interim spectral mask, the authorized value of EIRP is not exceeded, and
the transmissions comply with the spectral energy dispersal requirements. The statement
accompanying the FCC Form 304A or ITFS construction notification must also identify the name,
address, telephone number, and firm or company name of the person who performed the tests.
" Approximately 95 percent of all new ITFS applicants lease excess capacity to wireless cable operators
ot exceeded, and
the transmissions comply with the spectral energy dispersal requirements. The statement
accompanying the FCC Form 304A or ITFS construction notification must also identify the name,
address, telephone number, and firm or company name of the person who performed the tests.
" Approximately 95 percent of all new ITFS applicants lease excess capacity to wireless cable operators. See
MDS Auction Order, 10 FCC Red at 9594.
87 The ITFS service has a "one-step" licensing process whereby a successful applicant is awarded, as part of
the same authorization, both an implied construction permit and a license which is conditioned upon construction.
See ITFS Technical Order, 98 FCC 2d at 934-35. While no formal mechanism exists for the ITFS licensee to notify
the Commission that construction has been completed, this is customarily done in a letter sent by the licensee to the
Commission. See Amendment of Part 74 of the Commission's Rules and Regulations in Regard to the Instructional
Television Fixed Service, 59 RR 2d 1355, 1381 n.46 (1986) ("[T]he one-step licensing process . . . requires
notification of the completion of construction.").
18870
Federal Communications Commission FCC 96-304
55. Amendments to pending ITFS applications and applications to modify ITFS facilities
are governed by Section 74.911 of the Commission's Rules, 47 C.F.R. � 74.911. Section
74.91 l(a) states that an application will be considered to be one for a major change if it involves
adding or changing channels, changing polarization, increasing power or transmitting antenna
height by certain amounts, or relocating a facility's transmitter site by at least 10 miles. See ITFS
Window Filing Order, 10 FCC Red at 2923-24. Applications for any other changes normally are
considered to be for minor changes.
56. We do not believe that proposals to use digital transmitters need to be considered
major changes under Part 74 of the Commission's Rules
transmitting antenna
height by certain amounts, or relocating a facility's transmitter site by at least 10 miles. See ITFS
Window Filing Order, 10 FCC Red at 2923-24. Applications for any other changes normally are
considered to be for minor changes.
56. We do not believe that proposals to use digital transmitters need to be considered
major changes under Part 74 of the Commission's Rules. Classifying such proposals as major
changes would restrict their filing to filing windows. See ITFS Window Filing Order, 10 FCC
Red at 2907-11. In addition, the proposed use of digital compression does not give an applicant
for interim digital authority the right to add any new ITFS channels, as contemplated by the
major change provisions of Section 74.911 (a). See note 11, supra; cf. Comband II, 61 RR 2d
at 146 (use of Comband analog compression does not increase the number of channels utilized).
Furthermore, while a major change triggers a petition to deny period under Section 74.91 l(c),
interested parties are provided adequate announcement of a minor change through its listing on
public notice, and they may file objections pursuant to 47 C.F.R. �� 74.910 and 73.3587.
Commission staff also retains the flexibility under Section 74.911 to reclassify any application
as a major change should the circumstances warrant Therefore, ITFS applications proposing
substitution of a digital transmitter, which are filed in accordance with the procedures described
above, will normally be regarded as minor changes. Cf. Comband II, 61 RR 2d at 146
(considering substitution of a Comband analog compression transmitter to be a minor change
under Section 74.911). Such applications may be filed at any time and are not subject to window
filing procedures. However, we still are as concerned about interference avoidance with ITFS
digital operations as we are with MDS digital operations, so we are requiring performance of
interference studies by ITFS applicants for interim digital transmission authority
mitter to be a minor change
under Section 74.911). Such applications may be filed at any time and are not subject to window
filing procedures. However, we still are as concerned about interference avoidance with ITFS
digital operations as we are with MDS digital operations, so we are requiring performance of
interference studies by ITFS applicants for interim digital transmission authority. See para. 53,
supra. We intend to reexamine the classification of such applications in a future rulemaking
proceeding.
57. An MDS application amendment to change the type of transmitter emission is
normally considered to be a major amendment under 47 C.F.R. � 21.23(c)(2)(iii). However, for
purposes of this interim ruling, pursuant to 47 C.F.R. � 1.3, we waive Section 21.23(c)(2)(iii) on
our own motion and will consider amendments to change to digital transmission to be minor.88
Modifications to MDS facilities to change to digital transmission are governed by 47 C.F.R.
88 When completing FCC Form 304, MDS applicants filing amendments to change to digital transmission shall
check "Minor amendment to pending application" for Question 3.
18871
Federal Communications Commission FCC 96-304
� 21.40(a).89 Pursuant to 47 C.F.R. � 21.27(a)(l) and (5), as applicable, public notice will be
given of the filing of either a formal application by a licensee or conditional licensee proposing
to add or switch to digital transmission, or an amendment to a pending application for this
purpose. For purposes of this interim ruling, we also waive 47 C.F.R. � 21.27(c) to the extent
it requires a thirty day waiting period following the issuance of a public notice listing an
application to modify an MDS facility for digital operations. MDS and ITFS parties in interest
will be given an opportunity to comment and to raise interference objections hi accordance with
Section 21.300)) of the Commission's Rules, 47 C.F.R. � 21.30(b)
so waive 47 C.F.R. � 21.27(c) to the extent
it requires a thirty day waiting period following the issuance of a public notice listing an
application to modify an MDS facility for digital operations. MDS and ITFS parties in interest
will be given an opportunity to comment and to raise interference objections hi accordance with
Section 21.300)) of the Commission's Rules, 47 C.F.R. � 21.30(b). These rule waivers will
expedite the introduction of digital technology to wireless cable under interim authority, and bring
the procedures for processing such applications into conformance with the procedures pertaining
to ITFS applications for interim digital authority. Moreover, there will be no detriment to the
public interest resulting from these waivers, because MDS applicants for interim digital authority
must comply with all interference protection and study requirements normally relevant to MDS
applicants, and the testing and statement-of-performance process described above will provide
further safeguards against harmful interference.
F. ITFS Programming Requirements
58. Section 74.931 of the Commission's Rules describes the purpose and permissible
service of ITFS stations, and also sets forth the minimum ITFS programming requirements for
ITFS licensees. See 47 C.F.R. � 74.931. Section 74.93 l(e)(9), which allows an ITFS licensee
to shift its required educational programming onto fewer than its authorized number of channels
via channel loading or channel mapping, specifies that an ITFS licensee who leases excess
channel capacity to a wireless cable operator must provide a total average of at least 20 hours per
channel per week of ITFS programming on its authorized channels. ITFS licensees in such lease
arrangements also retain the right to recapture "an average of an additional 20 hours per channel
per week for simultaneous programming on the number of channels for which it is authorized."
47 C.F.R. � 74.93 l(e)(9)
o a wireless cable operator must provide a total average of at least 20 hours per
channel per week of ITFS programming on its authorized channels. ITFS licensees in such lease
arrangements also retain the right to recapture "an average of an additional 20 hours per channel
per week for simultaneous programming on the number of channels for which it is authorized."
47 C.F.R. � 74.93 l(e)(9). Petitioners ask the Commission to confirm that, at least during the
interim period governed by this ruling, we will not require additional ITFS programming by
licensees who expand their spectrum capacity by utilizing digital compression technology. See
Petition at 35. Petitioners particularly rely on the Mass Media Bureau's decision hi Comband
II and urge the Commission to retain the policy announced in that case. Petitioners suggest that
any interim ruling would be without prejudice to any rules that may ultimately be adopted
establishing the recapture rights of ITFS licensees with respect to the increased capacity made
89 We will classify such filings as modifications of station licenses under Section 21.40(a). Although we
believe the terms "major" and "minor" are not precisely pertinent, the MDS applicant for interim authority to modify
its facilities for digital operations nevertheless shall check "Major change to authorized station" for Question 3 when
completing FCC Form 304. Likewise, the MDS applicant for such modifications shall remit the fee prescribed in
47 C.F.R. � 1.1105(7Xb) when filing the FCC Form 304.
18872
Federal Communications Commission FCC 96-304
available by digital compression. See Petition at 37.90 We decline in the context of this petition
for declaratory ruling to impose any changes in ITFS programming requirements. Those
requirements remain the same regardless of the modulation technology. We will defer
consideration of any changes to our ITFS programming requirements to a future rulemaking.
IV. ORDERING CLAUSES
59
CC 96-304
available by digital compression. See Petition at 37.90 We decline in the context of this petition
for declaratory ruling to impose any changes in ITFS programming requirements. Those
requirements remain the same regardless of the modulation technology. We will defer
consideration of any changes to our ITFS programming requirements to a future rulemaking.
IV. ORDERING CLAUSES
59. Accordingly, IT IS ORDERED that under the authority contained hi Section 4(i) of
the Communications Act of 1934, as amended, 47 U.S.C. � 154(i), and Section 554(e) of the
Administrative Procedure Act, 5 U.S.C. � 554(e), the Petition For Declaratory Ruling, on the use
of digital modulation by Multipoint Distribution Service and Instructional Television Fixed
Service Stations, IS GRANTED to the extent specified above. This Declaratory Ruling and
Order shall be effective upon its release and shall remain effective until adoption of rules
governing digital transmissions in MDS and ITFS in a future rulemaking proceeding. See 47
C.F.R. �� 1.4(b)(2) and 1.103. Nothing in this Declaratory Ruling and Order shall prejudice the
outcome of such a rulemaking proceeding.
60. IT IS FURTHER ORDERED that Subpart J of Part 2 of the Commission's Rules
(Sections 2.901 et seg.) pertaining to issuance of equipment authorizations prior to operation, and
Sections 21.120, 21.907(c), 74.938, 74.952, and any other of the Commission's Rules in Parts
2, 21 and 74 containing requirements for type acceptance of equipment and applicable to analog
MDS or ITFS transmissions, ARE WAIVED for existing analog equipment modified for digital
transmissions, to the extent specified above, subject to such conditions set forth in paras. 41 and
53 in the foregoing order.
61. IT IS FURTHER ORDERED that Sections 21.23(c)(2)(iii), 21.27(c), 21.904(d),
21.907,21.908(a) and (b), 74.935(d), 74.936(b), 74.950(a) and (f)(l), and 74.970 ARE WAIVED
to the extent specified above, subject to such conditions set forth in para
ified for digital
transmissions, to the extent specified above, subject to such conditions set forth in paras. 41 and
53 in the foregoing order.
61. IT IS FURTHER ORDERED that Sections 21.23(c)(2)(iii), 21.27(c), 21.904(d),
21.907,21.908(a) and (b), 74.935(d), 74.936(b), 74.950(a) and (f)(l), and 74.970 ARE WAIVED
to the extent specified above, subject to such conditions set forth in para. 53 in the foregoing
order.
90 In their comments, both Kraskin & Lessee and the Rural Coalition reiterate Petitioners' request with regard
to ITFS programming requirements. See Kraskin & Lessee Comments at 2; Rural Coalition Comments at 3.
18873
Federal Communications Commission FCC 96-304
62. IT IS FURTHER ORDERED that the staff of the Mass Media Bureau shall send
copies of this declaratory ruling to the parties filing formal comments by certified mail, return
receipt requested.
FEDERAL COMMUNICATIONS COMMISSION
William F. Caton
Acting Secretary
18874
APPENDIX A
PETITIONERS
Wireless Cable Association
International, Inc.
Wireless Cable Digital Research
Wireless Cable Research &
Development Center
ACS Enterprises, Inc.
Aims Community College
Alda Wireless Holdings, Inc.
Alliance for Higher Education
American Telecasting, Inc.
American Wireless Systems, Inc.
Andrew Corp.
Applied Video Technologies, Inc.
Arizona Board of Regents for
Benefit of the University of
Arizona
Atlanta MDS Inc.
Broadcast Cable Bloomington, Inc.
Broadcast Data Corporation
Block & Associates
Cablemaxx, Inc.
CAI Wireless Systems, Inc.
California Amplifier, Inc.
CFW Cable, Inc.
Chicago MDS Company
Communication Microwave Corp.
Colorado State University
Cross Country Wireless, Inc.
Decathlon Communications, Inc.
DeLawder Communications, Inc.
Denver Public Schools
Diocese of Orlando
EMCEE Broadcast Products
Evans Microwave, Inc.
Fresno City College
G & S Television Network, Inc.
General Instrument Corp
California Amplifier, Inc.
CFW Cable, Inc.
Chicago MDS Company
Communication Microwave Corp.
Colorado State University
Cross Country Wireless, Inc.
Decathlon Communications, Inc.
DeLawder Communications, Inc.
Denver Public Schools
Diocese of Orlando
EMCEE Broadcast Products
Evans Microwave, Inc.
Fresno City College
G & S Television Network, Inc.
General Instrument Corp.
Greater Dayton Public Television
Heartland Wireless Communications
Hispanic Information &
Telecommunications Network, Inc.
Indiana Higher Education
Telecommunications System
Indio Wireless Partnership
Instructional Opportunities, Inc.
ITS Corporation
KCTS Television
Kessler and Gehman Associates, Inc.
Lakeland BDC - MMDS Company
Lance Industries
Libmot Communications Partnership
Los Angeles MDS Company
Madison Communications, Inc.
Magellan University
Mariposa County Schools
McConnell Communications, Inc.
Microwave Filter Corp.
Milwaukee MDS Company
Minneapolis MDS Company
Robert S. Moore
Multimedia Development Corp.
National Wireless Holdings, Inc.
Network for Instructional TV, Inc.
New York MDS, Inc.
Orlando BDC - MMDS Company
Omni Microwave, Ltd.
Oregon Public Broadcasting
Orion Broadcasting Systems, Inc.
Pacific Monolithics, Inc.
People's Choice TV Corp.
Phoenix MDS Company
Pikes Peak Community College
Polk Community College
Portland Community College
Poudre School District - Rl
18875
Preferred Entertainment, Inc.
Pueblo Community College
Radio Training Network
Rapid Choice TV, Inc.
Regents of the University of
Minnesota
Region IV Education Service Center
Sacramento Wireless Company
San Diego MDS Company
South Carolina Educational Television
Commission
Southeastern College of the
Assemblies of God
Specchio Developers Ltd.
St. Louis MDS Company
St. Louis Regional Educational and
Public Television Commission
State of Wisconsin Educational and
Communications Board
Superchannels of Las Vegas, Inc
gion IV Education Service Center
Sacramento Wireless Company
San Diego MDS Company
South Carolina Educational Television
Commission
Southeastern College of the
Assemblies of God
Specchio Developers Ltd.
St. Louis MDS Company
St. Louis Regional Educational and
Public Television Commission
State of Wisconsin Educational and
Communications Board
Superchannels of Las Vegas, Inc.
Terres Associates
Teton Wireless Television
Thompson School District - R2J
University of Colorado at Colorado
Springs
University of Southern Colorado
University System of the Ana G.
Mendez Educational Foundation
Washington MDS Company
Weld County Schools
Weld County School District - 1
Weld County Schools - RE4
Wireless Broadcasting Systems of
America, Inc.
Wireless Cable of Atlanta, Inc.
Wireless Holdings, Inc.
Wireless One, Inc.
Zenith Electronics Corporation
18876
This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.