The FCC has received mixed views on a petition for rulemaking filed in June by Radwin Ltd. seeking an amendment of the agency’s part 15 rules to permit higher power operation for point-to-multipoint systems in the 5 gigahertz that would be consistent with the higher power allowed for point-to-point systems in the 2.4 GHz band (TR Daily, June 29).
Specifically, Radwin asked “that the FCC modify its rules to allow for the provision of improved broadband services in the U-NII-1 (5.15-5.25 GHz) and U-NII-3 (5.725-5.85 GHz) Unlicensed National Information Infrastructure (‘U-NII’) bands. The requested modification of the rules is consistent with the Commission’s approach in the 2400-2483.5 MHz (the ‘2.4 GHz’) band, and will promote the public interest by allowing for improved and greater access to broadband services, particularly in rural areas.”
In comments filed in Rulemaking 11812, some parties expressed support for the petition, others opposed it, and still others reserved judgment but asked the FCC to consider a variety of issues in the proceeding, including the impact of the requested rule change on Wi-Fi operations.
“In sum, WISPA believes that the rule changes proposed by RADWIN can offer significant improvements in fixed broadband deployment without increasing costs. The Commission therefore should adopt a notice of proposed rulemaking inviting comment on the Petition and the rules proposed therein,” said the Wireless Internet Service Providers Association.
WISPA said that Radwin “demonstrates that its beamforming technology will not result in interference greater than the interference that would be generated by point-to-point devices operating with directional antennas or point-to-multipoint devices using legacy sectorized widebeam antennas. Based on its review of RADWIN’s technical report, WISPA believes this to be true.”
Several WISPs, as well as other carriers, also filed comments supporting the petition. For example, the North Central Kansas Community Network said that “[t]he UNII-1 and U-NII-3 bands are already in widespread use to deliver broadband services to rural and remote customers, helping to close the digital divide – which is an FCC priority” and it said that the rule changes sought by Radwin “would permit even more effective use of these bands – they will permit higher power use but reduce congestion – a unique win-win opportunity.”
“Should the FCC agree, the case for rural high-speed broadband internet services becomes far more practical for providers choosing to employ beam-steering technologies regardless of the equipment manufacturer,” said ATC Communications (d/b/a ATCJet.net LLC). “More subscribers to fixed wireless services will see connections that comply with baseline connectivity and reliability in the networks will improve.”
“As discussed in the Petition, P2MP systems that utilize electronically steered sequential multiple directional beams will allow users, such as fixed wireless providers, to provide high-quality, broadband connections over the U-NII-1 and U-NII-3 bands with less risk of creating or receiving harmful interference (compared to traditional P2MP systems),” said California Internet, L.P. (d/b/a GeoLinks). “Because fixed wireless providers, such as GeoLinks, have no incentive to cause interference (which would only serve to diminish their own signals), the Company believes that the industry as a whole will take great care in coordinating frequencies and transmission paths in order to operate these sequential multiple directional beams in the bands, pursuant to revised rules.”
“In environments like ours – which are common to many WISPs nationwide – the economics of deploying service to such thinly-populated areas can range from challenging to prohibitive. The type of beam-forming/beam-steering technology exemplified by RADWIN products, combined with the proposed power increases, makes serving these types of rural communities significantly more feasible,” said Cal.net, Inc. “Not only do the higher gain and tighter beams enable more customers to be served with higher speeds from any given location, they also provide the secondary benefit of reducing interference in comparison to traditional sectorized wide-beam antennae. The resulting improved spectrum efficiency thus also advances competitive opportunities by allowing more operators to serve a given area.”
“The use of point-to-multipoint base stations with beam-forming and beam-steering antennas with higher power will enable them to transmit further, meaning that fewer base station transmitters will be required to be deployed, and more customers can be reached from existing sites,” said PocketiNet Communications, Inc.
In joint comments, Frontier Communications Corp. and Windstream Services LLC also endorsed the proposed rules. “Updating the rules governing the U-NII-1 and U-NII-3 band to conform with the rules already in place for the 2.4 GHz band by allowing next-generation beam-forming antennas to operate at increased power levels will enable the deployment of better quality of service broadband to more people without increasing interference or adversely affecting existing usage in the band,” the carriers said. “By adopting this commonsense proposal, the Commission can reap great dividends for rural broadband and enable companies to unleash faster broadband for an even greater number of rural Americans.”
“Amending Section 15.407(a) of the Commission’s rules, 47 C.F.R. § 15.407(a), as requested in the RADWIN Petition, to allow devices that emit multiple directional beams, simultaneously or sequentially, for the purpose of directing signals into individual receivers or groups of receivers to operate under the emission rules applicable to fixed, point-to-point operations, would generate substantial public interest benefits,” Alaska Communications Internet LLC said. “It would advance the Commission’s broadband deployment goals by allowing more rapid and efficient deployment, including by recipients of CAF Phase II support. In addition, it would allow providers to overcome deployment challenges of distance, terrain, or clutter that impair the coverage of fixed wireless broadband services today. And, RADWIN has demonstrated that it could achieve these benefits with no material increase in harmful interference to other users of the band.”
“Radwin seeks changes to the rules for point-to-point operation in the 5 GHz band that would authorize devices emitting multiple simultaneous or sequential beams to operate at the much higher power levels typically reserved for directional fixed point-to-point devices. This presents significant concerns regarding the potential for harmful interference to existing operations, including Wi-Fi, in the 5 GHz band,” NCTA said. “Radwin suggests that its proposed changes will align the 5 GHz rules for point-to-multipoint (P2MP) operation with corresponding rules in the 2.4 GHz band. However, Radwin’s proposed rule changes do not reflect the narrative’s focus largely on rural areas, and in fact, would open the door to much broader implementations with serious potential to degrade current operations in the U-NII bands. The proposed changes also do not contain the 2.4 GHz limits relating to P2MP operation, which balance higher permitted power levels with upper limits on total power and/or appropriate reductions in power corresponding to increases in antenna gain. The Commission should carefully evaluate the potential interference impact of the rule changes on widely deployed Wi-Fi operations in the 5 GHz band in light of the need for substantial safeguards, and any proposed rule change should exclude simultaneous P2MP transmissions.”
The Wi-Fi Alliance said that, in principle, it “believes that rule changes designed to encourage the expanded use of electronically steered and phased antenna arrays will lead to more efficient use of the U-NII-1 (5.15-5.25 GHz) and U-NII-3 (5.725-5.85 GHz) bands, and may be instrumental in fostering an expansion of wireless Internet access. Nevertheless, Wi-Fi Alliance encourages the Commission to assess the impact of the deployment of high-power, non-line-of-sight, point-to-multipoint systems in urban and suburban settings, or more generally in locations with a high density of Wi-Fi users, on the performance of low-power systems. Wi-Fi Alliance therefore urges the Commission to adopt a Notice of Proposed Rulemaking (‘NPRM’) seeking comment on and further exposition of the proposed amendments.”
Facebook, Inc., said it “supports industry efforts to promote more flexible and intensive use of unlicensed spectrum. RADWIN’s proposal to permit devices in the 5.15-5.25 GHz and 5.725-5.85 GHz bands (‘5 GHz Band’) that sequentially emit directional beams represents a promising step in that direction. In particular, allowing steerable, active phased-array antennas in outdoor settings at the higher power levels applicable to point-to-point links will result in the more intensive use of the 5 GHz Band, eliminate unnecessary siting costs, and unlock new 5G deployment scenarios. These technologies can help meet the growing need for unlicensed spectrum by encouraging more spectrally efficient use of the 5 GHz Band.”
Facebook added that while it “finds much to commend in RADWIN’s Petition, any reforms to the 5 GHz Band must preserve the fundamental character of unlicensed spectrum by continuing to allow non-rivalrous deployments. By promptly initiating a Notice of Proposed Rulemaking (‘NPRM’), evaluating the technical merits of RADWIN’s Petition, and assessing the need for additional interference-mitigation criteria, the Commission can help meet the twin goals of maximizing efficient deployments in the 5 GHz Band while preserving coexistence.”
The National Public Safety Telecommunications Council said it “neither specifically supports nor opposes the Radwin petition. However, NPSTC believes there are at least three key areas that the Commission should explore further, especially if it chooses to pursue a rulemaking as Radwin requests. These areas involve 1) differences in the overall technology between the 2.4 GHz and 5 GHz bands that could influence the impact, and not just the P2P/P2MP rules; 2) a comparison of the potential interference impact from simultaneous multiple beams vs. that from sequential multiple beams; and 3) the potential impact to the 5 GHz noise floor from Radwin’s recommended rule changes. Regarding the noise floor issue, NPSTC recommends the Radwin petition be considered in the context of the recent Globalstar petition reporting a 2 dB rise in the noise floor, rather than as a stand-alone issue.”
Globalstar, Inc., said it opposes Radwin’s petition, arguing that the company “fails to justify this rule change or a Notice for Proposed Rulemaking (‘NPRM’) on its proposal. RADWIN disregards Globalstar’s recent Petition for Notice of Inquiry. It fails to address how its proposed power increase would affect the ongoing noise floor rise at 5.1 GHz or the threat of harmful aggregate interference to Globalstar’s licensed mobile satellite service (‘MSS’).”
Globalstar said that if the FCC “feels compelled to consider RADWIN’s request, it should do so as part of a Notice of Inquiry regarding the ongoing noise floor rise at 5.1 GHz and the threat of harmful aggregate interference to Globalstar’s licensed MSS operations.”
In its petition for an NOI, Globalstar has cited a “dramatic rise” in noise that the company said it is getting into its 5.1 GHz band feeder uplink. In its petition, Globalstar asked the FCC to consider “the viability of continued spectrum sharing between its licensed Mobile Satellite Services (‘MSS’) and outdoor Unlicensed National Information Infrastructure (‘U-NII’) devices operating in the 5150-5250 MHz ‘U-NII-1’ band” (TR Daily, May 22).
The American Radio Relay League said it also opposes the Radwin petition. “The relief requested by Radwin would allow unlicensed, high-power Part 15 wide-bandwith systems operating between 5.725-7.850 GHz to transmit on multiple azimuths at once. As the Band 5.65-5.925 GHz is allocated on a secondary basis to the Amateur Service, ARRL has a substantial interest in the compatibility, if any, between the proposed high-power Part 15 devices in this band and incumbent and future Amateur station operation,” ARRL said.
“This Petition is flawed in its inception and fails to justify the relief requested. In particular, the Petition fails to address the issue of compatibility between high power, P2MP Part 15 operation proposed and individual stations in the incumbent primary and secondary allocated services. It also fails to address the aggregate effect of the rule change on ambient noise levels in the subject band and the Commission has absolutely no independent data on that subject itself,” ARRL argued. “It is long past time that petitioners such as Radwin provide in their rulemaking petitions dealing with Part 15 rules enough data to allow the Commission to make an evaluation that fulfills its obligation under Sections 152 and 301 of the Communications Act of 1934. Radwin’s Petition must be dismissed as one which fails to provide an adequate justification for the relief requested.”- Paul Kirby, firstname.lastname@example.org