Leaked Study Claims 'No Additional Testing Needed'

Bloomberg has received a draft of a report scheduled for official release Wednesday on the potential of LightSquared's proposed broadband network to interfere with GPS receivers. So far, it doesn't look good for the wireless company.

According to the report, of 92 GPS devices tested by the US Defense Department, the FAA and some GPS manufacturers, LightSquared's network would interfere with 69 of them, or three-quarters. Perhaps anticipating continued political and marketing efforts from LightSquared, the report also makes clear, "No additional testing is required to confirm harmful interference exists."

LightSquared's troubles began when it acquired rights to a block of radio spectrum adjacent to frequencies used for GPS. Because engineers have always anticipated the potential for interference, those frequencies are reserved by international treaty only for satellite downlinks, which will, like GPS signals, be relatively weak. As has been the case with TV receivers and other consumer products, these protections allow GPS receivers to be manufactured with inexpensive shielding and filtering, based on the assumption strong signals from other services won't appear on frequencies close to the receiver's.

While aviation GPS units could hardly be called cheap, they also are designed without the shielding and selectivity needed to protect receivers from powerful competing signals on adjacent frequencies.

LightSquared subsequently changed its business plan to augment satellite coverage with 40,000 ground-based transmitters of up to 1,500 watts each. Those terrestrial transmitters create signals which are as much as a billion times as strong as GPS signals from satellites, creating much more interference potential than GPS receiver designers have been told to expect.

Federal Communications Commission Chairman Julius Genachowski, who lives in a political climate which values making broadband internet service available even in remote, rural areas, fast-tracked approval of LightSquared's revised plan without the normal allowance for public comment or even a full vote of his own commission. The Department of Defense was caught off-guard at first, but quickly joined aviation and manufacturing interests in raising red flags when it became clear what was about to happen to GPS functionality.

In response to criticism from federal lawmakers, Genachowski has turned a frequent criticism about the FCC's hindrance of industry around. "The commission’s rules permit decisions to be made on delegated authority to ensure the timely consideration of pending requests to support a robust and active telecommunications industry and to ensure that the agency is not placing unnecessary barriers in front of commercial activity, private investment and job creation."

The controversy has not been good for Harbinger Capital Partners, the hedge fund which is backing the LightSquared project. Bloomberg reported in June that investors have tried to pull as much as a billion dollars out of the fund.

Regarding the leak of the draft interference study, LightSquared Executive VP Martin Harriman responded to Bloomberg, "This breach attempts to draw an inaccurate conclusion to negatively influence the future of LightSquared and narrowly serve the business interests of the GPS industry."

FMI: www.lightsquared.com ; www.saveourgps.org