February 1, 2021 – In a written ex parte, NTCA–The Rural Broadband Association has filed a technical whitepaper to aid the review of long-form applications submitted by Rural Digital Opportunity Fund (RDOF) auction winners that propose to provide Gigabit broadband service using fixed wireless technologies.[1]

The technical whitepaper is titled Evaluating the Capabilities of Fixed Wireless Technology to Deliver Gigabit Performance in Rural Markets, and is intended to be used as a “roadmap” to help the FCC evaluate the technical aspects RDOF winners’ fixed wireless networks.

Numerous RDOF auction winners will receive funding to provide Gigabit-level broadband service to sparsely populated rural areas using fixed wireless networks, which is something NTCA says should be concerning.

The whitepaper notes that because there is no proven “track record with respect to fixed wireless technologies” delivering Gigabit broadband to rural areas, the FCC should “take a careful look, based upon objective engineering criteria, at whether and to what degree fixed wireless networks can deliver Gigabit level services” to rural areas “where serviceable locations can be several hundred feet to miles apart.”

It “concludes that there are significant technical (and related economic) questions that must be confronted in delivering Gigabit broadband using fixed wireless technologies in the predominantly rural areas covered by RDOF and the FCC therefore needs to perform a careful analysis pursuant to objective and well‐accepted technical engineering criteria during the long‐form process prior to approving such claims of capability.”  

Among other things, the whitepaper provides parameters for evaluating networks using mid-band and high-band spectrum. For example, the whitepaper sets forth the following parameters for fixed wireless networks using high-band spectrum:

When considering any proposed wireless network designs based on millimeter wave (mmW) technologies for any RDOF winner to satisfy their Gigabit broadband service commitment, the FCC should verify the following:

1. All customers must be within about 500 feet of their specific serving tower/antenna.

2. All customers must have clear line‐of‐sight to that serving tower/antenna.

3. The capacity of the serving tower/antenna or sector must be adequate to accommodate the downstream and upstream capacities of all users served by that antenna or tower.

a. The RDOF 70% subscription requirement must be considered in analyzing the capacity of the service tower/antenna or sector.

b. A reasonable oversubscription ratio on the order of 4:1 or less should be applied.

4. Each antenna and/or sector must also have adequate backhaul capacity to accommodate the number of RDOF customers anticipated with a reasonable oversubscription ratio such as 4:1. In most instances this will require the towers/antennas to be served with a fiber network.

5. When considering mmW mesh networks, in addition to the preceding factors, the FCC should also evaluate the congestion that would occur between the nodes of the mesh network as well as the potential radio frequency congestion and the backhaul congestion.

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[1] NTCA Ex Parte, Rural Digital Opportunity Fund, WC Docket No. 19-126; Connect America Fund, WC Docket No. 10-90; Auction 904, AU Docket No. 20-34 (Feb. 1, 2021), https://ecfsapi.fcc.gov/file/10201387611048/Letter%20and%20technical%20whitepaper%20on%20Gigabit%20standards%20020121.pdf.