Smart, or short-sighted? LightSquared proposes swapping half its network for FCC approval

LightSquared may be putting off the FCC, but it’s taking its argument directly to the public that a work-around exists for its network interference problems. On Monday it revealed what it deems to be a viable fix for the problems it now acknowledges its proposed long-term evolution (LTE) would create for nearby GPS receivers, which operate in a neighboring band.

What LightSquared proposes is simply to not use all of its spectrum—at least initially--creating a temporary guard band between its interference-prone downlink carriers and the GPS band so it can launch its network on schedule while sorting out interference issues later. The solution hasn’t exactly been vetted by the GPS industry, which along with government agencies and LightSquared are part of a technical working group the FCC created to settle the interference debate once and for all.

The group was supposed to file its final report and recommendations with the FCC last Wednesday, but LightSquared filed for two extensions to give it more time to explore the proposed fix it just announced (Unfiltered: The LightSquared waiting game). By announcing its work-around before the report goes public, LightSquared likely is trying to head off its conclusions and get in front of what is expected to be a firestorm of criticism from the GPS industry. Initial findings from government agencies and information leaked from the group’s draft report to the Wall Street Journal show not everyone is convinced that there a workable solution exists (Unfiltered: LightSquared interference data piles up).

In response to LightSquared’s announcement, Trimble general counsel and member of the Save Our GPS coalition Jim Kirkland issued a statement, criticizing the operator’s tactics:

“This latest gambit by LightSquared borders on the bizarre. Last week LightSquared unilaterally delayed filing of the study report that culminated months of intensive work to evaluate interference to GPS, because they purportedly needed two more weeks to analyze the results. Days later, well before the report is scheduled to be filed, LightSquared unilaterally announces that it has found a ‘solution.’”

Specifically LightSquared proposes to scrap its initial deployment plans and build its launch network in further-down-the-satellite frequency bands in order to give GPS a wider birth. Its initial plans called for deploying a 5 MHz-by-5 MHz carrier with a downlink channel occupying the frequencies between 1550 MHz and 1550 MHz, which would put it right up against the GPS bands starting at 1559 MHz. As LightSquared expanded, it planned to deploy a second 5 MHz-by-5 MHz carrier with the downlink 23 MHz further down the band chart. LightSquared now proposes to use that second carrier for its nationwide rollout, while staying clear of the higher frequency block.

One problem with that scenario is that LightSquared doesn’t yet directly control those alternate frequencies. It signed a deal with Inmarsat to swap out their interleaved L-band spectrum in order to create the big blocks of frequencies needed for a wideband LTE deployment (CP: LightSquared swapping spectrum with Inmarsat). At the end of the process, LightSquared would be able to devote 40 MHz of its 59 MHz to a split-spectrum LTE deployment, while reserving for the rest of its frequencies for satellite coverage and a possible time division-LTE (TD-LTE) launch. LightSquared and Inmarsat started phase 1 of the swap in August but at the time they said they needed 18 months to fully implement it. LightSquared, however, said it is in discussions with Inmarsat about accelerating the process, which would allow it to keep to its rollout timeline.

Even using the lower frequencies would still produce some interference with GPS, though it would be limited to high-precision equipment, LightSquared conceded. The consumer GPS found in car navigation systems and location-enabled cellphones would be unaffected, it claimed, but critical highly sensitive instruments such as avionics equipment and surveying gear would see an impact. LightSquared said it believes it has an answer for that problem as well: it said it would agree to cut the maximum transmission power of its base stations to 50% of what the FCC originally authorized. With a lower-power network, LightSquared would have to build a denser footprint, but such a topology would provide additional protection to GPS.

“This new plan will give LightSquared enough spectrum to serve its growing customer base for the next several years,” LightSquared stated. “During this time, LightSquared will not use the spectrum it originally planned to use for the launch of its network.”

It doesn’t look likely that the GPS industry will sign off on the deal. Save Our GPS’s Kirkland called the proposal a “Hail Mary” pass in a last ditch effort to salvage LightSquared’s business model. “It’s time for LightSquared to move out of the [mobile satellite services] band,” he said in his statement.

More: End Result…Cutting Its Network in Half