WISPA pushes testing to validate 4.9 GHz spectrum sharing

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The Wireless Internet Service Providers Association is advocating cooperative testing of a geolocation database and network equipment to prove that commercial users could easily share the 4.9 GHz band with public-safety users on a secondary basis.

"By using geolocation database capabilities and ensuring that public safety users have priority access during times of incidents, the concerns of those opposing or suggesting deferral of consideration for secondary use can be alleviated," said WISPA in reply comments concerning FCC efforts to establish the nationwide broadband public-safety network as well as promote interoperability in 700 MHz commercial spectrum.

The commission already tentatively intends to enable commercial users to share the 4.9 GHz band with public safety licensees, a plan WISPA supports. However, numerous commenters have expressed reservations about the idea, contending that opening the 4.9 GHz band to commercial users would result in increased congestion and interference.

WISPA contends that if congestion were to become an issue, it would impact secondary, or commercial, users only. "WISPA members, the vast majority of which operate on unlicensed frequencies, accept this risk and can make their spectrum plans accordingly," said the group.

WISPA contends that previous situations where public-safety users suffered from interference, as in the case of "incompatible uses" in the 800 MHz band, can be prevented in the 4.9 GHz band via the use of a geolocation database. That approach is already being used to open TV white spaces to commercial broadband uses while protecting incumbent TV stations and others. "There is no reason why the same protocols and safeguards cannot be adopted here to protect public safety and other primary users," said WISPA.

However, even Spectrum Bridge, a designated TV white space administrator, has recommended that the FCC defer action on opening the 4.9 GHz band until "various ecosystem constituents implement a realistic market trial to address questions and concerns."

Citing concerns expressed by the National Public Safety Telecommunications Council and the Association of Public-Safety Communications Officials International, WISPA acknowledged that "the public safety community may need convincing" of the merits of its proposal and offered to participate in cooperative testing of geolocation database solutions and network equipment compatibility.

The 4.9 GHz band consists of a contiguous block of 50 MHz located at 4940-4990 MHz and is currently designated for public-safety fixed and mobile uses. The FCC envisions the band being used for numerous applications, such as temporary mesh networks at emergency scenes and city-wide Wi-Fi networks for first responders. In addition, the commission has said the spectrum could be used to backhaul the national 700 MHz public safety broadband network and provide wireless broadband connectivity in remote or sparsely populated locations.

For more:
- see this WISPA filing

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