LightSquared last week proposed an amended version of its LTE network plan, which was designed to fix the problem of its signal interfering with other GPS units and calm the fears of many in the GPS community.
The company proposed two significant modifications. LightSquared will still use the lower 10 MHz part of its L-Band spectrum, but will limit the power of its base stations to -30dBm. According to tests, LightSquared claims this action did not degrade the performance of GPS devices, even of devices that were above that threshold.
The second modification includes a solution for satellite-augmented GPS, which is used for precision ag services. LightSquared proposed permanently using a 4 MHz piece of spectrum for those services, which will provide them with a stable satellite signal. This would give the company time to develop a better filtering system with the possibility of an antenna replacement or module modification for legacy precision GPS receivers.
The Coalition to Save our GPS said in a statement that the newest plan, “appears to be a positive step toward reducing, for some devices, the harmful interference to GPS signals confirmed during testing of LightSquared’s earlier incomplete proposals.”
LightSquared’s national network could serve roughly 260 million people using satellites and land-based signals. The interference issues have been over the land-based portion of the network.