C. Technical Overview of LPFM Services
22. We are tentatively persuaded that the different visions and service demands for low power radio could not be well accommodated by a single class of LPFM service. Therefore, we propose two distinct classes of service: (1) a primary LPFM service class with an ERP limit of 1,000 watts (designated "LP1000") and (2) a secondary class with an ERP limit of 100 watts (designated "LP100"). We also seek comment on the advisability of establishing a very low power secondary "microradio" service with ERP limit of one to ten watts. We first give a technical overview of these services and then focus on key technical and nontechnical issues for the proposed LPFM services.
1. 1000-Watt Primary Service ("LP1000")
23. We propose LP1000 stations that would operate at a maximum effective radiated power ("ERP") of 1000 watts at an antenna height above average terrain ("HAAT") of 60 meters (197 feet). 35 In order to give station operators maximum flexibility to make use of available sites consistent with our interference protection criteria, we do not propose a minimum HAAT. These appear to be reasonable limits for such a service. We propose to protect the 1 mV/m (60 dBu) signal contour of LP1000 stations operating at the maximum ERP and HAAT levels. The minimum separation distances to other stations would be derived on this basis. We note that 60 dBu is the protected contour for Class A stations, the next highest class of FM station. We believe this value would work well with the proposed power and height limits and provides a reasonable compromise between the size of LP1000 service areas and the preclusion of other radio services. For example, an LP1000 station would preclude authorization of another LP1000 station on the same channel within 65 kilometers (40 miles). See Appendix B.
24. The proposed power/height combination would produce a 60 dBu signal contour at a distance of 14.2 kilometers (8.8 miles) from the station, or approximately one half the distance to the protected 60 dBu contour of a Class A station using maximum facilities. 36 Such a service contour could cover a significant portion of many urban or suburban areas, and most medium-size or small rural communities. Depending on population density, terrain and other relevant factors, such a station could reach a substantial number of listeners. We seek comment on whether this service should be restricted to noncommercial applicants, open to commercial service, or both. We also seek comment on whether the population in these service areas could be large enough to sustain an advertising base.
25. A signal range of more than 8 miles should enable service to mobile listeners and to people living on farms or ranches in the vicinity of small rural communities. However, we ask whether the type of service envisioned for LP1000 stations could be met with lower power levels and/or antenna heights. We do not believe that a higher power or antenna height, such as the 3000 watt/100 meter limit proposed by Skinner, which surpasses many current radio facilities, would be necessary to achieve the goals we have set forth. We are concerned that the greater interference protection requirements for stations operating at Skinner's proposed power and height limits would sharply restrict opportunities for new stations in most mid-sized and larger markets. The need for larger facilities could be met by Class A FM stations, which operate at ERP levels up to 6 kilowatts. Thus, the upper limits of 1000 watts and 60 meters are being proposed because, we believe, they represent a good compromise between achieving a moderate service area and permitting reasonably closely spaced LP1000 stations on the same or adjacent channels. We note that a 60 meter antenna height would not require FAA clearance at many locations. This height should also be likely to provide a clear signal path within many areas to be served. We seek comment on the above parameters and assumptions, as well as on any reasonable alternatives.
26. In paragraph 0, below, we propose minimum distance separations between stations as interference protection criteria for LPFM stations. These separations would be based on LPFM stations operating at their maximum permitted ERP and HAAT. Thus, LPFM stations operating below the maximum levels would preclude other FM service on the basis of the upper ERP and HAAT limits. While we believe LPFM stations should have some flexibility to operate below maximum levels, we believe there should also be a lower ERP limit in the interest of efficient use of the radio spectrum. For this purpose, we propose a minimum ERP of 500 watts which, with a HAAT of 60 meters, would produce a 60 dBu service contour at a distance of 12 kilometers (7.5 miles). We do not propose a minimum value for HAAT. Applicants seeking to operate smaller facilities could apply for LP100 stations. We invite comment on the issue of minimum power and height levels of LP1000 stations and whether different levels would be more appropriate either in general, or in specific circumstances such as to meet distance separation requirements or in order to accommodate a negotiated settlement agreement.
27. Primary stations 37 operating in the FM service are required to protect all other primary stations. 38 We propose to extend such primary status to LP1000 stations, which we believe could strengthen this class's ability to serve as an entry-level radio service. Because LP1000 stations would cost more to construct and operate than LP100 stations, secondary status might discourage potential new entrants from investing their time and money into this service, thereby frustrating its purpose.
28. These stations would operate under the majority of the service rules and obligations applicable to primary stations generally. We note that LP1000 stations would have a maximum service area more than six times larger than LP100 stations and, as just noted, would be more expensive to construct and operate. As primary stations, LP1000 stations would be required to give and receive co-channel, first-adjacent channel, and IF interference protection equivalent to the protection levels other primary FM stations provide each other.39 Likewise, new and modified facilities of existing classes of FM stations would be required to give co-channel, first-adjacent channel, and IF interference protection to LP1000 stations equivalent to the protection that they provide to each other. The extent of interference protection to and from LP1000 stations would be based entirely on minimum station separation requirements, at least during the initial implementation of the LPFM services.40 We propose that LP1000 stations protect other LP1000 stations on the same channel and first-adjacent channel, and we invite comment on whether these stations should have to protect each other's IF frequencies; i.e., for FM channels separated by 53 or 54 channels.41
29. We invite comment on our proposals to create an LP1000 class and afford it primary frequency use status. Commenters should consider the desirability of such a service as well as its potential impact on other FM service classes. We are also concerned whether an LP1000 service would limit or impair the ability of full power stations to implement digital transmission technology such as in-band-on-channel ("IBOC") conversion. As further discussed at paragraph 0, below, we seek comment on this concern. We also seek comment on the impact of affording LP1000 stations primary status against secondary FM translator and booster stations.42 In what manner should these stations protect LP1000 stations? Should the current scheme for translator and booster protection of FM stations be extended to protect LP1000 stations?43 Should FM translator and booster service pre-dating the launch of an LP1000 service receive "grandfathered" interference protection from LP1000 stations? We also seek comment on whether to prohibit the establishment of any translator or booster stations for use in conjunction with LP1000 stations, given our desire to maximize ownership and service opportunities for locally owned LPFM stations.
2. 100-Watt Secondary Service ("LP100")
30. The 100-watt class would be intended to meet the demand of people who would like to broadcast affordably to communities of moderate size (whether standing alone in rural areas or as part of a larger urban area). We propose to establish an LP100 service to permit stations to operate as a secondary service at maximum facilities of 100 watts ERP and 30 meters (98 feet) HAAT. 44 This combination would produce a 1 mV/m (60 dBu) signal contour at a distance of 5.6 kilometers (3.5 miles) from the station. Depending on population density, an LP100 station might serve from a few hundred to several thousand listeners. We note that these parameters would produce roughly equivalent coverage area to the parameters proposed by Skinner for a similar service (50 watts ERP at 150 feet HAAT). We believe that our proposed limits would facilitate more economical station construction, and we seek comment on this view. We propose a minimum LP100 ERP of 50 watts which, with an HAAT of 30 meters, would produce a 60 dBu signal contour at a distance of 4.8 kilometers (3 miles) from the station. As with LP1000 stations, we do not propose a minimum HAAT for LP100 stations. This is in order to give station operators maximum flexibility to make use of available sites consistent with our interference protection criteria. We invite comment on all of these power and height values. Are the resulting coverage areas appropriate, or would alternative levels for power or height be more suitable for the envisioned purposes of this LPFM service class? Should this service be restricted to noncommercial applicants, open to commercial service, or both? Should there be a different lower power limit for this service, such as 30 watts? We also propose lesser operating and service requirements, see Section G., below, to compensate for the more limited service area of LP100 stations. We invite comment on these and other options to promote an affordable community broadcasting service.
31. We propose that LP100 stations would operate on a secondary basis with respect to all primary radio stations, including LP1000 stations. They would not be permitted to cause interference within the protected service contours of existing and future primary stations, nor would they be protected from interference from these stations. LP100 stations would provide co-channel, first-adjacent channel, and IF interference protection to the existing FM station classes, and co-channel and first-adjacent channel protection to LP1000 stations.45 We invite comment on whether LP100 stations should also provide IF protection to LP1000 stations. In paragraphs 0-0, below, we seek comment on our proposal not to require LPFM stations to provide 3rd-adjacent channel protection, as well as whether such stations should be required to provide second-adjacent channel protection or to receive such protection. By proposing secondary status for LP100 stations, we believe we could authorize more of these stations with less impact on primary broadcast services. In this regard, efforts of full service radio stations to relocate and/or upgrade their facilities would not be curtailed by the need to protect much smaller facilities. If LP100 stations were primary, for example, a Class C FM station using maximum power and antenna height would have to protect all co-channel LP100 stations within a distance of 126.5 miles.46 However, there may be situations in which secondary LP100 stations might not be concerned about being forced either to cease broadcasts or relocate to a different channel as a result of technical changes to a nearby primary station. For example, in some of the more congested areas, higher power FM stations may possibly be unable to upgrade their facilities to a higher class, due to the need to protect nearby full power stations. In these situations, LP100 stations could fill the "gaps" between gridlocked full power stations. In the less congested areas of the country, we would expect that displaced LP100 stations could more readily be relocated to alternate frequencies.
32. We seek comment on our proposal that LP100 stations be afforded a lower spectrum use priority than LP1000 stations. LP1000 stations would serve larger areas, be more expensive to build and operate, and would be subject to many of regulations applicable to primary FM services. New LP100 stations would be required to protect existing LP1000 stations. We seek comment on whether new LP1000 stations should be required to protect existing co-channel and 1st-adjacent channel LP100 stations. If such protection were not required, LP100 service could be disrupted, which might discourage operation of these stations. In commenting on this issue, commenters should address the likely cost differences between LP1000 and LP100 stations, including costs of station construction and operation. Commenters should also consider the costs of complying with the additional regulations that would apply to LP1000 stations (see the discussion of LPFM service rules in Section G., below). We also seek comment on whether LP100 stations should be permitted to select channels without regard to interference received from other stations. Preliminary staff analysis suggests that many more LP100 stations could operate if these stations were permitted to apply for channels for which up to 10% of the area within the 60 dBu contour would be predicted to receive interference.47
33. We tentatively conclude that the proposed LP100 secondary service would serve the public interest. We invite comment on our technical proposals for this service, including power and antenna height limits and the secondary status of the service. As further discussed in paragraph 0, below, we seek comment on the effect, if any, of an LP100 service on full power operations and their eventual digital conversion. We also seek comment on the likely impact of LP100 stations on FM translator and booster stations. Should LP100 stations be authorized on an equal basis with FM translators and boosters, since both would be secondary services, or should LP100 stations be primary with respect to FM translators and boosters, which do not originate programming? If FM translators are treated as a secondary service vis a vis LP100 stations, should we provide "grandfathered" interference protection to translator and booster service existing before our adoption of the LP100 radio class? To promote localism, should we prohibit translator or booster rebroadcasts of the programming of LP100 stations?
3. 1-10 Watt Secondary "Microradio" Service
34. We seek comment on the creation of a third class of LPFM service, which would be intended to allow an individual or group of people with very limited means to construct a broadcast facility and permit them to reach listeners within the confines of a very localized setting. This service would operate with a maximum antenna height of 30 meters HAAT (and no minimum HAAT) and ERP levels in the range of one to ten watts. These values would produce a 1 mV/m (60 dBu) signal contour at distances of about 1.8 kilometers to 3.2 kilometers (1-2 miles), depending on the ERP level. This class would be similar to that proposed in the Leggett petition, except that it would not be limited to a single designated channel. Clearly, microstations would offer only very limited coverage, such as for schools, small neighborhoods, subdivisions, or town centers. We seek comment on whether such facilities could satisfy some of the demand that has been expressed for very inexpensive community radio services, particularly in places where LP100 stations could not be located due to interference concerns or financial constraints. Construction costs for such a broadcasting apparatus could be quite low, potentially in the hundreds of dollars for some facilities. We seek comment on whether such a class of service should be restricted to noncommercial applicants, open to commercial service, or both.
35. If we adopt a microradio service, we believe there should be an FCC transmitter certification requirement. We are vitally concerned that such stations meet transmitter out-of-channel emission limits and other standards related to interference protection of stations on adjacent channels. We note that uncertified equipment has on numerous occasions caused dangerous interference to aviation frequencies.48 We do not believe that a certification requirement would overly burden small operators, given the recent streamlining of our certification procedures.49 We seek comments on this proposal, including not only burdens of compliance, but specific harms that could result from not requiring transmitter certification.
36. If we were to establish a microradio class, we would envision it as being secondary to all other FM radio services, including LP100 stations. Microradio stations would be required to protect all existing and future primary stations against co-channel and 1st-adjacent channel interference, as well as FM translator and boosters, and would not receive protection from these stations. Interference protection to these services would be based on minimum distance separations. We expect that many microstations could be located on this basis.50 While a single station operating from 1 to 10 watts ERP may not pose a serious threat for 2nd- or 3rd-adjacent channel or IF interference, where the interference range might extend only a few hundred feet, we are concerned about uncertain effects of the combined interference potential of possibly many such stations operating on the same channel in the same general area, and we seek comment in this regard. We also seek comment on the extent to which a very low power service would adversely affect full power stations in their current operations or eventual transition to digital.51
37. We invite comment on the merits of a very low power "microradio" class of LPFM service. While we are cognizant that many commenters believe that one watt would be insufficient power for any LPFM service,52 we include it in our proposal to allow additional comment. We are uncertain whether the service would be more feasible at a somewhat higher power level, such as 10 watts ERP. Commenters should weigh the possible benefits and possible adverse impact of microradio stations and should consider appropriate distance separations to govern interference protection for such stations. If we were to adopt a microradio stations class, should such stations be required to protect each other against interference?
35 Antenna heights greater than 60 meters HAAT would be permitted, but an appropriate downward adjustment in ERP would have to be made such that the 1 mV/m F(50,50) signal contour radius would not exceed 14.2 kilometers.
36 A Class A FM station may operate with an ERP up to 6 kilowatts at an HAAT of 100 meters (328 feet), which produces a 60 dBu contour at a distance of 28 kilometers (17.4 miles). 47 C.F.R. ' 73.211(b).
37 Noncommercial Class D, FM translator, and FM booster stations are "secondary" services, which "primary" stations are not required to protect.
38 Nonreserved band protection requirements may be based either on distance separations or on a combination of distance and contour-based restrictions. Noncommercial educational stations in the reserved band rely solely on a signal strength contour methodology. See 47 C.F.R. '' 73.207, 73.209, 73.213, 73.215 and 73.509 and the discussion of FM interference protection requirements in Appendix A.
39 All LP1000 stations would receive interference protection, and would provide interference protection based on the assumption of maximum facilities (1000 watts, 60 meters HAAT) at the station, irrespective of the actual facilities used, just as is done for all current classes of commercial FM stations. Required minimum station separations would be based on the desired-to-undesired signal strength ratios used to determine protection to other radio classes; e.g. 20 dB protection for co-channel and 6 dB for 1st-adjacent channel stations. As addressed in paragraphs 0-0, below, we are proposing not to require LP1000 stations to give, or receive, 3rd-adjacent channel interference protection to or from any class of FM radio station, and we seek comments on the need for 2nd-adjacent channel protection requirements. Nevertheless, to guide commenters, we include in Appendix B the equivalent minimum separation distances for LPFM protection to stations authorized on 2nd- and 3rd-adjacent channels. Stations operating on channels 201-220 would be required to protect TV Channel 6. See 47 C.F.C. ' 73.525.
40 We are not proposing to accept "short-spaced" LP1000 applications requiring case-by-case analysis and review. Such labor-intensive applications, the number of which could be quite large, would undermine our processing efforts and the simplicity essential for a service intended to be readily accessible to the widest segment of the public. We believe that the public interest would be best served by an efficient and expeditious licensing process based on straightforward distance separation requirements.
41 Station separations requirements for stations operating on channels that are 53 or 54 channels apart are intended to control intermodulation interference caused by the mixing of signals in a receiver that produce counterfeit signals falling on the receiver's intermediate frequency. These separations are premised on non-overlapping 36 mV/m contours of the stations whose signals could mix together to cause interference.
42 FM translator stations are secondary stations which receive the signals of primary FM stations and rebroadcast the FM programming on a different channel. FM boosters rebroadcast FM primary signals on the same channel. 47.C.F.R. ' 74.1201.
43 FM translator or booster stations are generally not permitted to cause interference to the reception of regularly used signals of authorized radio broadcast stations. 47 C.F.R. ' 74.1203. Applications for FM translator stations are not accepted for filing if the proposed facilities would result in prohibited overlap of their specified field strength contours and the protected contours of authorized FM radio stations. Interference protections are afforded to co-channel stations and stations on the 1st-, 2nd-, and 3rd-adjacent channels and IF channels; i.e., channels separated by 53 or 54 channels from that of an FM radio station. 47 C.F.R. ' 74.1204.
44 Antenna heights greater than 30 meters HAAT would be permitted, but an appropriate downward adjustment in ERP watts would have to be made such that the 1 mV/m F(50,50) signal contour radius would not exceed 5.6 kilometers.
45 The protection provided by LP100 stations would assume the use of maximum (100 watts, 30 meters HAAT) facilities, even if lesser facilities are used. LP100 stations operating on channels 201-220 would also have to protect TV Channel 6 (see 47 C.F.R. ' 73.525).
46 A Class C station using maximum power and antenna height has a co-channel interference contour (0.1 mV/m) with a radius of 198 kilometers (123 miles), and would thus have to protect all co-channel LP100 station coverage contours within that distance. LP100 coverage contours would extend 3.5 miles from their station sites. Given the likelihood that large numbers of LP100 stations would be operated, modifications to Class C stations, as well as all other existing station classes, would become extremely difficult, if not impossible, if they were required to provide interference protection to LP100 stations.
47 In 1st-adjacent and co-channel situations, the interfering contour extends significantly farther than the protected contour. Therefore, an LP100 station could provide protection to a full service station's protected contour and still receive significant amounts of interference.
48 See, e.g., para. 0, below.
49 See Report and Order in Gen Docket No. 98-68, FCC 98-338 (released Dec. 23, 1998) (Equipment Authorization Streamlining R&O).
50 One-watt microstations would have a co-channel interference contour (0.1 mV/m, based on a protection ratio of 20 dB) with a radius of 5.7 kilometers (3.5 miles) and a first-adjacent channel interference contour (0.5 mV/m, based on 6 dB protection) of 2.6 kilometers (1.6 miles). Such stations could be located as close as 5.7 kilometers to the edge of the service area contour of the nearest co-channel station or 2.6 kilometers to the edge of the service area contour of the nearest first-adjacent channel station.
51 See para. 0, below.
52 For example, the Community Radio Coalition ("CRC") proposes a minimum of five watts. CRC Petition for Rule Making at 3.