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Wireless technology developers urged FCC to move forward with allocation plan for 71–76 GHz, 81–86 GHz and 92–95 GHz that would allow commercial users and govt. and scientific operations to co-exist. Allocation and licensing proposals for W-band frequencies were part of comments due this week in rulemaking that would pave way for commercial operations in those bands for first time. Developers have eyed that millimeter wave spectrum for rollout of gigabit-per-sec. broadband capacity, particularly in areas where fiber couldn’t reach easily.
FCC in June proposed rules that would cover fixed point- to-point operations in that spectrum, with intent of promoting more spectrum sharing between federal and nonfederal users in band. Potential applications included high-speed wireless local area networks, broadband access systems and point-to-multipoint and point-to-point communications. Citing 71–76 GHz and 81–86 GHz part of proposal, Cisco said those frequencies could deliver very high bandwidths previously available only via fiber, meaning that technology could provide broadband connections to buildings without fiber connections.
Companies and trade groups offered range of licensing options for bands, with most advocating that Commission not conduct auction for that spectrum. FCC indicated geographic area licensing could reduce administrative burdens on agency and applicants, although rulemaking sought comment on site-based licensing as well. Cisco favored site-by-site system, urging blanket licensing under which each operator would obtain FCC license for first link. Operator then would hire “path coordinator” to coordinate additional links and notify FCC of successful coordination. Unlicensed use wouldn’t be suitable for application at 70 and 80 GHz, partly because those users were more likely to want full interference protection and because of need for professional installation and tower rights that set those bands part from other unlicensed spectrum, filing said. Cisco proposed creation of “accreditation regime” for path coordinators and requirement that they handle all coordination.
While FCC proposal teed up site-by-site and geographic area licensing for feedback, Fixed Wireless Communications Coalition (FWCC) proposed 3rd option of “frequency coordinated licensing by rule.” Under that proposal, applicant would use Web site to enter proposed link data and pay to cover coordination costs. That database would keep tabs on previously coordinated links and either clear request immediately or e-mail information to other affected users who would have short window to object, FWCC said. “Individual sites would not be licensed, users would not have a call sign and the Commission would keep no record of the link data,” filing said. “We believe such an arrangement would preserve the advantages of site-by-site licensing, while automating much of the administrative overhead and shifting what remains to the private sector.”
Coalition voiced concern about allowing unlicensed operations as underlay on licensed, fixed service bands. In other bands, unlicensed operation under carrier-grade communications must meet power limit that’s 81 dB below that in pending proposal, FWCC said. “Proliferation” of noncoordinated, unlicensed devices at very high power levels is not compatible with 5 nines reliability that some fixed service users require, FWCC said. “Without some highly dependable mechanism for preventing interference, we urge segmenting the spectrum between licensed and unlicensed uses.” FWCC wants FCC to allocate 71–76 GHz and 81–86 GHz for fixed service subject to unlicensed operation, saying that was “badly needed” to help alleviate growing shortage of fixed service spectrum. Group advocated swapping uplink and downlink sides of fixed satellite service (FSS) and mobile satellite service (MSS) allocations to become downlink at 71– 76 GHz and uplink at 81–86 GHz to protect radio astronomy operations at 81–86 GHz. FWCC “strongly” opposed allocation for nongovt. FSS operations in band, saying sharing between fixed service and FSS elsewhere hadn’t been achievable.
Boeing, which has interest as both satellite systems manufacturer and millimeter-wave technology developer, advocated site-by-site licensing. It said it was “premature” to adopt satellite downlink power flux density limits in upper millimeter wave frequencies “because any limits would undoubtedly constrain the development of satellite services, which may not be implemented on a commercial scale for some time.” FCC should let satellite and fixed interests conduct sharing studies on whether power limits were needed for federal and nonfederal satellite systems to protect fixed receive stations from satellite downlink transmissions at 71– 76 GHz. Company backed adoption of fixed wireless allocations and service rules in near term to “permit prompt usage” of spectrum above 70 GHz. Boeing said commercial fixed millimeter wave systems usually could be rolled out faster than commercial satellite millimeter wave systems. Satellite receive earth stations in those bands could be blocked from large or densely populated areas where fixed stations could launch early operations, Boeing said. It supported U.S. adoption of modified footnote in ITU Radio regulations for 71–76 GHz to protect “federal and nonfederal satellite receive earth stations from earlier deployment of fixed stations.” Boeing said that change would direct that fixed, mobile and broadcasting services in band not cause harmful interference to FSS, MSS or broadcast satellite service (BSS) operations.
Sprint agreed with FCC decision to allocate that spectrum along lines of allocations made at World Radio Conference 2000, which realigned allocations between 71 and 275 GHz to reflect requirements for passive services. In 71– 76 GHz, Sprint concurred with FCC proposal to consolidate satellite downlink operations and eliminate allocation for radio astronomy service at 72.77–72.91 GHz. But in line with arguments by Wireless Communications Assn., Sprint said FCC shouldn’t adopt new footnote to table of frequency allocations that would direct fixed, mobile and broadcasting services to not cause harmful interference to govt. FSS stations. Instead, Sprint said Commission should approve technical standards that would ensure nongovt. FSS and BSS services at 74–76 GHz would provide interference protection to govt. satellites. As for 81–86 GHz, Sprint said it agreed with part of proposal that would consolidate satellite uplink operations and encourage FCC to adopt standards ensuring interference protection to satellite operations. Sprint said it supported proposed co-primary allocation of 81–86 GHz for radio astronomy service and terrestrial operations but urged Commission to not adopt proposal for new secondary allocation for amateur and other services at 81–81.5 GHz “as this will significantly complicate frequency coordination.”
Cisco questioned part of FCC proposal that would add footnote to ITU-R language authorizing secondary amateur and noncommercial amateur radio satellites use of 75.5–76 GHz until Jan. 1, 2006. Cisco said full 71–76 GHz band should be available for fixed use no later than Jan. 1, 2004. While proposed footnote allocation is only for secondary use, “the Commission should take due notice of the difficulty of identifying the source of interference from amateur operations,” Cisco said. Company said it didn’t oppose proposed change in footnote that would bar stations in fixed, mobile and broadcasting services from causing harmful interference to stations in govt. FSS service in 74–76 GHz. But that proposal shouldn’t be expanded to protect BSS operations or nongovt. FSS operations, filing said. “Unlike government FSS users, commercial FSS users will attempt to deploy as many earth stations as possible, and in the absence of any evidence to the contrary one must assume that these stations will be located in major urban centers,” Cisco said. Giving BSS and nongovt. FSS operators right to evict previously licensed fixed, mobile and broadcasting users at 74–76 GHz would amount to “band segmentation, which the Commission has otherwise resisted,” Cisco said.