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LightSquared solves GPS interference with new device

LightSquared says a new product developed in partnership with GPS manufacturer Javad GNSS and due out in November will eliminate interference problems with high-precision GPS devices.

Marguerite Reardon Former senior reporter
Marguerite Reardon started as a CNET News reporter in 2004, covering cellphone services, broadband, citywide Wi-Fi, the Net neutrality debate and the consolidation of the phone companies.
Marguerite Reardon
4 min read

Wireless broadband provider LightSquared will have a solution on the market by November that mitigates its interference issues with high-precision GPS services, the company said today.

LightSquared, which is building a nationwide 4G LTE wireless broadband network using spectrum that is adjacent to the spectrum GPS device makers use, said it has developed receivers with GPS device manufacturer Javad GNSS that will eliminate concerns that the GPS community has brought forth regarding how its service would interfere with precision GPS devices.

"The solution we've come up with dispels the myth that a product that eliminates interference couldn't be done," Martin Harriman, executive vice president of LightSquared's Ecosystem Development and Satellite Business, said on a conference call with reporters. "We did it. And it didn't cost billions of dollars or 10 years to do it. We did it."

LightSquared hasn't started building its network yet, but its entire business has been called into question recently as it faces criticism from the GPS industry, which claims that its network will interfere with high-precision GPS satellite services used in industries such as agriculture, surveying, aviation, construction, and national defense.

Earlier this summer, LightSquared proposed a solution that would alleviate most of the interference issues between its service and GPS services. Specifically, it plans to use spectrum furthest from the GPS band to avoid interference. But the GPS industry has still been concerned that this solution won't solve the issue for high-precision GPS services that detect location within centimeters.

Harriman said that through its partnership with Javad GNSS, which makes GPS devices for such clients as the U.S. Geological Survey, has developed new receivers that can be used to avoid interference between LTE and GPS. Javad GNSS has also completed designing and testing prototypes that can be adapted to work with existing high-precision GPS devices, including those already being used in the field.

Preproduction units of these devices will be released for public tests in October. The high-precision receivers for positioning applications are expected to go to market by November 2011 and precision timing devices by March 2012, the company said in its release.

It's unclear what the total price tag could be to retrofit existing high-precision GPS devices. Harriman said on the call that the company is still getting an idea of how many of these devices are in the field. He said the market is rather small, since there are few applications that truly need this level of accuracy. He also said that many of the devices are in remote locations, which may not be anywhere near LightSquared's soon-to-be-built network. What's more, much of this equipment will likely be replaced anyway within a few years, since the technology that is currently used for high-precision GPS location is being updated.

"The tests conducted so far by the GPS industry did not take into account the GPS modernization plan that is in place," Javad GNSS founder Javad Ashjaee said in the press release. "Since we have demonstrated that LightSquared can certainly coexist with the current GPS satellite signals, the coexistence will be even stronger when the new GPS satellites with modern L1C, L2C, and L5 unencrypted codes are launched."

Harriman also said that the new receivers, which essentially filter the signals transmitted from LightSquared's LTE service so they don't interfere with devices that are listening for GPS signals, can also incorporate LTE into these devices to offer access to a terrestrial wireless broadband network.

"The GPS industry has been looking for a way to augment the satellite signal," Harriman said. "And our suppliers have already developed a dual-mode chip for satellite and LTE services. So we don't see LightSquared as a threat to the GPS industry, but a terrific opportunity for GPS."

LightSquared is building its nationwide wireless broadband network to sell capacity to other service providers, as well as retailers looking to offer wireless broadband service. The company has already signed partnerships with companies, such as Leap Wireless and Best Buy. It is using spectrum that was allocated for both terrestrial and satellite uses. While its network will be terrestrial-based, it must get approval from the Federal Communications Commission before it starts offering the service. The agency gave LightSquared a waiver earlier in the year to use spectrum.

For months, the GPS industry has been lobbying Congress and the FCC to stop LightSquared's plans until more testing of its service can be completed. The FCC and the U.S. Commerce Department's National Telecommunications and Information Administration has asked for more testing of LightSquared's proposed solutions before the agencies sign off on the plan.

LightSquared officials say they are confident that the news of these new devices that mitigate interference for the high-precision GPS devices will help get it the necessary approval from these agencies so that it can begin building the network.