Doug Lung /
FCC Grants Alvarion Transmitter Power Waiver
In the search for new spectrum for wireless broadband, the existing allocation at 3650-3700 MHz appears to be underutilized. Licensing is not difficult, but I don't see a wide range of inexpensive hardware available for this band. It isn't surprising, therefore, that the FCC has granted an application from Alvarion, an Israeli-based WiMax provider, for certification of an indoor subscriber unit for its BreezeMax 3.65 Broadband Wireless Access System, even though the unit would operate at higher power levels than normally allowed for "mobile" devices.
The BMAX-Si is a compact subscriber unit intended for indoor installation at residential or business location by a non-professional user. The BMAX-Si has six internal antennas and a connection to an optional wall/window detached antenna. It operates with channel bandwidths of 3.5 MHz and 5.0 MHz in the 3650-3675 MHz band. When used with the internal antennas, the calculated EIRP for a 5 MHz bandwidth is 1.58 Watts (32 dBm).
The FCC declined to approve the BMAX-Si as a fixed station, which has to meet special requirements and have special rules to protect grandfathered C-band earth stations and Federal Government radiolocation stations in the band. Fixed stations are allowed to operate at higher power because they would remain at specific locations registered in an FCC database and could not be located within a specified distance from grandfathered earth stations without a bilateral agreement.
"Consistent with the Commission's goals in the 3650 MHz proceeding, we do not find that compact, desktop devices that can be operated by consumers with internal antennas unconnected to any fixed mounting should be certified as a fixed station, which would be entitled to operate at a power level up to 25 W / 25 MHz EIRP," the FCC said.
However, the Commission concluded that the BMAX-Si could be certified as a mobile device with a waiver allowing operation above the maximum power specified for such devices. The FCC said that allowing certification of the BMAX-Si "furthers the underlying purposes of the rules so long as such mobile stations are used on (1) in the fixed mode; (2) after registration in ULS; and (3) subject to the coordination zones set forth in Section 90.1331."
The Order [PDF]
certifying the device notes that this affords grandfathered facilities the same protection from the BMAX-Si as from fixed wireless units.
Alvarion is permitted to market and sell the units only to 3650 MHz licensees, not directly to end users and consumers. Licensees must agree to, and be responsible for, customer/user operation of the device in compliance with the Order. The Order also requires Alvarion to include "sufficiently detailed installation instructions and guidelines to ensure that licensees locate the BreezeMAX Si CPE in a manner that will maintain appropriate human exposure separations at all times."
Although C-band earth station users have expressed concern that 3.65 GHz band devices could cause interference to satellite reception, increased use of this band could help take some pressure off broadcast and broadcast auxiliary spectrum.