About the 3650-3700 MHz Service
In 2005, the Commission adopted a non-exclusive licensing scheme for the band, in lieu of an unlicensed scheme that
was originally proposed in April 2004. In reaching this decision, the FCC considered several factors, including the band’s encumbrance
with grandfathered satellite Earth stations and radiolocation operations, which will prevent new terrestrial use in major population centers along the
east and west coasts of the Nation, and the lack of pairing opportunities with other spectrum for duplex operations.
This, as well as evidence that the band is well suited to high-power broadband operations, persuaded the Commission that much of the interest
in developing the band is focused on smaller markets and less densely populated areas. For these reasons, the Commission structured the
band’s rules to provide Wireless Internet Service Providers (WISPs) and other providers an economical means of quickly initiating broadband
services, particularly in under-served and rural areas. The Commission concluded that this licensing approach struck an appropriate balance,
providing a regime with low entry costs and minimal regulatory delay, while still ensuring more orderly operation than would exist under a traditional
unlicensed approach in which users must accept interference from others in the band and users’ locations are unknown.
The Commission also designed the 3650 MHz band rules to provide flexibility for a variety of new terrestrial uses in order to encourage multiple entrants including a requirement that equipment operating in the band incorporate a contention-based protocol to minimize interference. The Commission concluded that contention-based protocols are well suited to avoiding
interference among the multiple users that seek to use the band simultaneously. Under the Commission’s rules, contention-based protocols can be broadly
categorized as either “unrestricted” or “restricted.” Unrestricted protocols are broadly compatible and function to prevent interference even with other,
dissimilar contention technologies on the market. Restricted contention protocols can prevent interference only with other devices incorporating the same protocol.
The Commission, through the equipment certification process, retains the authority to determine whether equipment that operators seek to deploy in the band meets
the requirements established for contention-based protocols.
As a further means of promoting effective shared use of the spectrum, all 3650 MHz licensees must cooperate and “make every effort” to avoid harmful
interference and the FCC specifically declined to give interference priority to licensees who are the first to deploy in an area. To facilitate the negotiations that
must accompany the cooperative use of the band by multiple entrants, the Commission requires that all 3650 MHz band licensees register their fixed and
base stations in a common database, i.e., ULS.
The Commission also adopted a number of provisions to protect grandfathered satellite Earth stations, which retained their primary status,
against interference from the newly authorized operations in the band. Specifically, the Commission created 150 km circular protection zones
around approximately 100 grandfathered FSS Earth stations and prohibited terrestrial operations in the band within these zones, absent agreement with the
affected satellite operators. Additionally, requests to register base or fixed stations within the 80 km circular protection zones established around each of
three Federal Government radiolocation stations will only be approved upon successful coordination by the FCC with NTIA.
To provide further protection to the grandfathered earth stations, the Commission set maximum permissible power levels for both mobile and
fixed or base stations operating in the band and required that mobile units be configured to transmit only when they could receive an enabling signal
from a licensed base station. See Public Notice DA 07-4605 (pdf
for the filing procedures that detail the licensing and the fixed and base station registration process.