2 GHz MSS Terrestrial Spectrum Use Likely to Impact ENG Sites
March 9, 2012
One of the items on the tentative agenda for the FCC's March 21, 2012 open meeting is titled "Advanced Wireless Service in the 2 GHz Band Notice of Proposed Rulemaking (NPRM) and Notice of Inquiry."
The NPRM will propose service, technical, assignment and licensing rules for "flexible terrestrial use of spectrum currently assigned to the Mobile Satellite Service (MSS) in the 2 GHz band." You may recall that part of this MSS spectrum is from former 2 GHz Broadcast Auxiliary Service (BAS) Channels 1 and 2. The FCC rejected a request from Dish Network for a waiver (similar to the one granted LightSquared) to build a terrestrial network using its MSS spectrum in this band and took a slower approach through the proposed rulemaking. Last year I reported on Dish network's plans for TerreStar 2 GHz spectrum.
Broadcasters have been installing filters to reject interference from new wireless base stations operating just above 2110 MHz. If the NPRM allows use of the MSS spectrum in the 1990-2025 MHz former BAS band, then additional filtering is likely to be required to reduce interference to current BAS Channel 1, which starts at 2025 MHz.
LightSquared's plans to use its MSS spectrum for a terrestrial network were shot down when tests showed it would cause interference to GPS receivers. Interference to broadcast users is unlikely to get as much attention, although this spectrum is essential for providing viewers of both broadcast and cable networks with live on-the-scene coverage of breaking news. Filters can reduce interference; however, to be effective they have to be installed before the first amplifier in the system. That preamplifier is usually mounted at the antenna, so installing filters may require bringing in a tower crew, removing the antenna, installing the filters, and hoisting the antenna back on the tower.
Wireless carriers with systems operating adjacent to 2 GHz BAS spectrum are required to coordinate with users of the adjacent spectrum to avoid interference, although unlike the Nextel conversion, where Nextel had to cover all costs of relocating users to a new channel plan, these licensees of adjacent spectrum are only required to coordinate with BAS users. This means that while they may provide filters to protect ENG receive sites, it seems unlikely they will easily cover the considerable cost of installing these filters on tower mounted antennas.
In the Notice of Proposed Rulemaking and Notice of Inquiry the FCC is planning to adopt at its next open meeting I'll be looking to see what requirements they put on MSS licensees for protecting broadcast 2 GHz ENG from terrestrial systems and other users of adjacent spectrum.
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