Analysis: Sorting out the LightSquared GPS interference mess

As the controversy over LightSquared’s proposed long-term evolution (LTE) network heats up, so has the rhetoric exchanged between the GPS industry and the satellite-operator-turned-4G provider. The GPS industry is adamant that no terrestrial network can go up in L-band without knocking out GPS receivers – and thus the applications and services that depend on their location data. LightSquared has not only maintained it can build a network—at least a partial one—that won’t interfere with GPS devices, but has accused the GPS industry of resisting any attempts to find a solution.

The finger pointing even spilled out into the report LightSquared and the GPS industry filed last month on the feasibility of LTE and GPS co-existing in the L-band (CP: LightSquared lashes back at GPS industry). Many parts of the 300-page report read like an argument between the two camps rather than a technical study. In fact, in many of the report’s sections, separate headings were designated to LightSquared and GPS representatives to air their separate interpretations of the same data.

Most recently, LightSquared has taken the offensive, claiming that GPS device makers are solely to blame for any interference on their devices due to the poor design choices they’ve made over the years. The GPS industry has called those claims ludicrous.

Who’s right? The political and public relations aspects of this debate may be dominating the argument, but underneath those broad, emotionally charged claims are some underlying technical facts—though they’re much more nuanced than either side could put out in a press release or sound bite. With the help of some of testing and measurement firm Spirent’s technical experts, Connected Planet attempted to ferret some of those truths out. Let’s start with the first and seemingly most outrageous claim.

Next: Are GPS device makers responsible for their devices’ interference problems?