Oh, the places you’ll go…

Posted in Financials, LightSquared, Operators, Regulatory, Spectrum at 5:27 pm by timfarrar

Over the last few days, a new series of filings by the US GPS Industry Council have appeared in the LightSquared ATC waiver docket, making some fairly dramatic statements about the potential for interference from LightSquared’s ATC network. As an aside, it is rather curious that these filings didn’t appear to be available when I was writing about this issue on Monday (Jan 24), despite the fact that some of the submissions were received by the FCC as early as January 19.

The January 20 USGPS Industry Council filing includes an analysis by Garmin International of potential interference scenarios for a “very common” consumer automotive navigation device (the nüvi 265W) and a Generation Aviation GPS receiver (the GNS 430W) based on LightSquared supplied parameters for network operations using a 5MHz LTE downlink channel between 1550MHz and 1555MHz. The conclusion of the analysis is that the LightSquared network “will create a disastrous interference problem for GPS receiver operation to the point where GPS receivers will cease to operate (complete loss of fix) when in the vicinity of these transmitters”. Specifically, the report states that “the nüvi 265W lost a fix at a distance of 0.66 miles (1.1km) from the transmitter”, while the GNS 430W “will be completely jammed by LightSquared transmitters over 5.6 miles (9.0km) away”.

The study that has now been mandated by the FCC’s Order is tasked with “identifying near-term technical and operational measures that can be
implemented to reduce the risk of overload interference to GPS devices, and providing recommendations on steps that can be taken going forward to permit broadband wireless services to be provided in the L Band MSS frequencies and coexist with GPS devices.”

However, these instructions make it clear that the aim of the study is to decide how rather than whether to provide terrestrial broadband wireless in the L Band MSS frequencies, and note that “Because the GPS interference concerns stem from LightSquared’s transmissions in its authorized spectrum rather than transmissions in the GPS band, the Commission expects full participation by the GPS industry in the working group and expects the GPS industry to work expeditiously and in good faith with LightSquared to ameliorate the interference concerns.”

One possibility for “ameliorating the interference concerns” is that LightSquared could be required to use L-band downlink channels which are further away from the GPS band than the originally intended 1550-1555MHz channel. However, LightSquared is intending to use 20MHz of downlink, so it will need to operate up to at least 1550MHz and quite likely somewhat higher if it is to operate four 5MHz LTE channels (because the 1544-45MHz band is reserved for safety services so only 3x5MHz channels could fit into the 1525-1544MHz part of the band, and it is possible there will have to be some guard band between the bottom of LightSquared’s fourth channel and the 1544-45MHz safety services). LightSquared might also have additional limitations placed on its operations in the vicinity of airports (e.g. no use of the fourth channel there), while GPS manufacturers could be required to use improved filters in the future, so that their receivers are better protected. However, it will take many years before the billions of dollars worth of existing GPS devices reach the end of their lifetimes, and LightSquared needs to be providing widespread service under its current rollout mandates by the end of 2012 (albeit not on four channels, because Inmarsat will not make the Phase 2 lease spectrum available until mid 2013).

As a result, it will be very interesting to see how the two sides of this debate can be reconciled. Conceivably a worst case for LightSquared might be that it would only be able to operate its ATC network below 1544MHz (i.e. with just three paired 2x5MHz terrestrial LTE channels). In that case, it is far from clear whether LightSquared would be able to renegotiate its lease with Inmarsat to give up 10MHz of the roughly 18MHz it is now committed to leasing under Phase 2 of the Cooperation Agreement. If LightSquared continues to pay the full $115M per year to Inmarsat, then any requirement to limit terrestrial operations to only 30MHz of ATC spectrum would have a fairly dramatic impact on the residual value of LightSquared’s own spectrum assets.

Nevertheless, it seems that the FCC is determined to make sure that the L-band MSS spectrum will be used for terrestrial services and appears to have concluded that LightSquared’s plan is the only possibility for that to happen in the foreseeable future. Thus, channeling Dr. Seuss (who I’ve noted before, had many great insights into the MSS industry), the FCC message to LightSquared seems to be:

“And will you succeed?
Yes! You will, indeed!
(98 and ¾ percent guaranteed.)”

Now, let’s just hope that any remaining GPS interference doesn’t end up resulting in a slight variant on Dr Seuss’s original story:

“You can get so confused that you’ll start in to race
Down long wiggled roads at a break-necking pace
And grind on for miles across weirdish wild space,
Headed, I fear, toward a most useless place.

And if you go in, should you turn left or right…
Or right-and-three-quarters? Or, maybe, not quite?
Or go around back and sneak in from behind?
Simple it’s not, I’m afraid you will find,
For a GPS system to make up its mind.”

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