From Connected Planet: 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.

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.

In a purely technical sense, LightSquared is right: GPS device makers — particularly high-precision instrument makers — purposely designed their devices to receive signals far outside of the designated GPS bands.

In theory, better filters in general GPS equipment and blocking filters in high-precision equipment could allow GPS and LTE to co-exist peacefully. In practice, no one knows, since such filters haven’t yet been implemented in commercial devices.

Read the entire article here.