Members of the Subcommittees on Maintenance, Systems Management and Operations, Special Committees on Wireless Communications, Transportation Security and Emergency Management, Frequency Coordinators
Good Morning,
I apologize if you receive multiple copies of this message but we are seeking a wide distribution to insure those needing the information receive it as quickly as possible.
Recently the Federal Communications Commission approved a Request for Waiver of the Commission's regulations allowing a firm to potentially build over 40,000 high powered transmitter sites throughout the United States. The waiver was granted on a "fast-track" basis in that it was approximately
60 days from application to grant. This included a very brief period in which to file comments from interested parties on the merits of the request. In short, the waiver grants a company, Lightsquared = authorization to build high powered transmitters using frequencies assigned to = satellite communications for the purpose of bringing increased broadband communications to commercial users.
The frequencies are located in what is known as the L-Band and they are adjacent to the L1 frequency used to send the timing signals from the US GPS Constellation to GPS units. Laboratory testing from Garmin has shown = a personal navigation device such as the GPS unit used in vehicles will = lose the satellite's signal at a distance of over 5 miles from one of these transmitters while aircraft relying on GPS technology will lose signal at distance of over 12 miles.
How is transportation affected? Many systems already deployed rely on the precision timing signals transmitted from the GPS constellation. Systems affected include survey instruments, radio systems, cellular telephone networks and, virtually all credit card transactions as they rely on the high precision timing data from GPS used as date/time stamps on the transactions.
To our collective knowledge, this is the first waiver of technical rules issued by the FCC without conducting extensive testing prior to ruling. The ruling has several conditions, the most critical is the requirement Lightsquared must demonstrate their system will not interfere with the reception of GPS satellite signals. The enclosed memo details some of the conditions Lightsquared must meet before they are allowed to commercially deploy their system.
AASHTO, in conjunction with both governmental and industry groups on this issue and will keep you informed of further developments. The next milestone is Lightsquared must produce a report detailing a plan to mitigate interference in mid-June.(See attached file: DA-11-367A1_LS WG.DOC)