Rich Fiscus
27 Oct 2011 16:47
LightSquared, a US company intent on building a nationwide wholesale LTE network, has announced yet another proposed solution for the GPS interference issues which have delayed FCC approval of their service.
LightSquared's problems stem from their proposal to transmit terrestrial mobile data on frequencies normally reserved for satellite communication. The frequency range they would be using is directly adjacent to the frequencies used for high precision GPS.
Because they are terrestrial, rather than satellite based, LightSquared's signals would be significantly more powerful, resulting in them overpowering the GPS signals. This would render GPS units used for applications ranging from aviation to agriculture to military operations effectively useless.
Despite claims in the past that a new antenna design for their towers would alleviate the problem, testing by the government's National Telecommunications and Information Administration resulted in a different conclusion. FCC approval of their service is contingent on NTIA approval.
In September the company announced the development of a filter which could be used to retrofit existing GPS equipment to filter out LightSquared's signal, but only offered to pay for the cost of modifying those units used by the federal government.
Their latest proposed solution, or actually 4 solutions, are a pair of antennae and another filter they say will solve the problem with a retrofit and a new receiver which could be used in new GPS units going forward.
They are being vague about the costs of these new components. Their previously announced solution would cost between $50 and $300 per device, not counting the cost of installation. One of the new antennae would apparently cost $6.
The cost of the other antenna, the filter, and the new receivers haven't been disclosed.
The most recent antenna will be undergoing independent testing at Alcatel-Lucent Bell Labs after which all of LightSquared's solutions will be submitted for NTIA testing.
If they prove to be as effective as LightSquared claims, there will still be the matter of paying for all the retrofitting to consider.