a m e r i c a ’ s P l a n c H a P t e r 5 cleared by 2015. Though aggressive by historical standards, this frequency coordination is required to ensure sufficient spec- timeline would bring additional mobile broadband capacity to tral and geographic reuse to maintain a high level of service market when it may be most needed. reliability. 124 In practice, this can create a scarcity of useful backhaul spectrum in high-traffic locations. This scarcity will 5.5 IncreasInG greater use of microwave services.only be exacerbated as the increase in broadband traffic drives the FLeXIBILItY, ReCoMMeNDaTioN 5.9: the Fcc should revise Parts 74, capacItY and cost- ing among compatible point-to-point microwave services. -78 and 101 of its rules to allow for increased spectrum shar eFFectIVeness oF 74, 78 and 101 of its rules and opportunities to increase shar-The FCC should commence a proceeding to examine Parts spectrUM For poInt- Auxiliary Service (BAS) and Mobile Cable TV Relay Serviceing of spectrum bands currently used for Mobile Broadcast to-poInt WIreLess as BAS and CARS have started to migrate to Internet protocol(CARS) with microwave services. Such sharing appears feasible BacKhaUL serVIces on these links fundamentally the same as that on common(IP)-based communications, making the traffic that is carried carrier microwave links. Increased sharing would have the Many wireless providers increasingly rely on microwave for practical effect of increasing the supply of backhaul-suitable backhaul, especially in rural areas. Therefore, the FCC should spectrum in the prime frequencies below 12 GHz.125 In the take steps to ensure that sufficient microwave spectrum is course of this review, the FCC should consider making below-1 available to meet current and future demand for wireless GHz “white spaces” spectrum available for backhaul in very backhaul, especially in the prime bands below 12 GHz. As a rural areas where it otherwise may go unused, to the extent that starting point, the FCC is considering revisions to its Part 101 such use is consistent with Recommendation 5.8.5 above and rules permitting operation of wider channels in the Upper 6 the ongoing white spaces proceeding. GHz Band, and faster activation of links on additional channel pairs in the 23 GHz Band. The FCC should take further actions ReCoMMeNDaTioN 5.10: the Fcc should revise its rules to enhance the flexibility and speed with which companies can to allow for greater flexibility and cost-effectiveness in obtain access to spectrum for use as wireless backhaul, which deploying wireless backhaul. is critical to the deployment of wireless broadband and other The FCC’s Part 101 microwave rules are intended to enable a wireless services high level of service reliability, but they may also limit deploy- Backhaul costs currently constitute a significant portion of ment flexibility in coverage- or capacity-limited situations. a cellular operator’s network operating expense. With 4G de- Therefore, the FCC should commence a proceeding to update ployments, this burden will become more acute as the demand these rules to reduce the cost of backhaul in capacity-limited for backhaul capacity increases. When fiber is not proximate urban areas and range-limited rural areas. In particular, the to a cell site, microwave backhaul can often provide a cost- proceeding should revise rules consistent with the following: effective substitute for data rates up to 600 Mbps. Further, ➤ Greater spatial reuse of microwave frequencies, particularly in in certain remote geographies, microwave is the only practi- urban areas. Public comment has raised the possibility that cal high-capacity backhaul solution available. Policies that rule changes could enable more efficient use of spectrum, facilitate microwave usage for backhaul will lower the cost of particularly in the area immediately surrounding a micro- 4G deployment and increase 4G availability in rural America. wave station.126 Such changes, it is claimed, could dramati- As with all wireless communications, operators’ ability to use cally increase the ability to use spectrum for backhaul in microwave depends on availability of spectrum and the dis- high-congestion areas, especially urban areas. The FCC, in tance of the link itself. In general, spectrum below 12 GHz is the context of a larger Part 101 proceeding, should expedi- preferred for long-link backhaul because of rain-fading effects tiously consider whether the proposal merits changes to the at higher frequencies.123 existing rules. Although microwave backhaul is a point-to-point service, ➤ Modification of minimum throughput rules, particularly in interference with other systems may occur in the beam contour rural areas. The FCC should consider modifying rules on as well as in side lobes near the radiating antenna. Therefore, minimum data throughput for each authorized microwave F e d e r a l c o m m u n i c a t i o n s c o m m i s s i o n | n a t i o n a l b r o a d b a n d P l a n 9 3
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