Skip to main content

FCC Sets Rules for Vehicle-Mounted Sat Stations

The FCC has released a Report and Order (FCC 09-64) adopting allocation, technical and licensing rules to permit U.S. licensing of Vehicle-Mounted Earth Stations (VMES) using "conventional" Ku-band frequencies in the 11.7-12.2 GHz (downlink) and 14.0-14.5 GHz (uplink) band on a primary basis and the "extended" Ku-band frequencies in the 10.95-11.2 GHz and 11.45-11.7 GHz (downlink) bands on a non-protected basis. Other "extended" Ku-band frequencies are excluded.

Uplink antennas used for VMES service must protect adjacent satellites with two-degree spacing, or reduce effective isotropic radiated power (EIRP) sufficiently to stay within the off-axis EIRP density limits. Antennas must remain pointed within 0.2 degrees of the desired satellite, or reduce the EIRP to remain within the off-axis power density limits. The tracking system must maintain a pointing error of less than or equal to 0.2 of a degree between the orbital location of the target satellite and the axis of the main lobe of the VMES antenna. If the angle exceeds 0.5 of a degree, the system then must cease transmission within 100 milliseconds. Systems that reduce EIRP density to allow greater error must declare, justify and abide by a maximum pointing error "that shall be achieved without exceeding the off-axis EIRP mask."

The new rules define the steps VMES applicants must take to avoid interference to other users of this portion of the spectrum. VMES licensees must coordinate proposed operations with federal SRS and RAS stations in the 14.0-14.2 GHz and 14.47-14.5 GHz bands, respectively.

VMES terminals that operate in the United States must be installed by qualified persons and properly labeled to protect the user or nearby persons from excessive RF exposure. The FCC agreed that since VMES terminals are not likely to be used within 20 centimeters of the operator's body, they are not "portable devices" under Section 25.129 of the rules, and therefore not subject to equipment certification as portable earth station transceivers.

Based on the discussion in the Report and Order, it appears the general public will not be the primary user of VMES terminals. However, as technology advances, how long will it be before we see VMES antennas on news and production vans?

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.