Lightsquared wireless vs. GPS

[Robert_Moriyama]

On the plus side, people would get faster streaming of their online multimedia (Avatar on a 3-inch screen! Woohoo!). On the minus side, they might not be able to tell where the %^#$#$ they are going...

FCC Directs Further GPS Tests Before LightSquared Decision
Aviation Daily, Monday September 19, 2011 p. 3

Additional testing for GPS interference is required before a decision can be made on whether to allow LightSquared to deploy its revised broadband wireless network, the U.S. Federal Communications
Commission (FCC) has decreed.

After testing showed widespread interference with GPS receivers, LightSquared modified its proposed terrestrial network to operate at lower power and only in the lower of its two frequency bands, the one furthest from GPS satellite signals.

LightSquared argues testing already conducted is sufficient to show most GPS receivers, including aviation systems, are not adversely affected by transmissions in its lower 10MHz frequency band. But GPS users say not enough testing of the revised network has been conducted to ensure there is no impact.

In testing conducted by the U.S. Defense Department, “We saw interference even with the lower 10,” Gen. William Shelton, chief of U.S. Air Force Space Command, told a hearing of the House Armed Forces strategic forces subcommittee Sept. 15 in Washington. Most testing was conducted in LightSquared’s original dual-band network configuration.

“We conducted only limited testing [in the lower 10], and precision receivers, even some cellphone receivers, were affected. Further testing is required,” he said. “The results thus far from the testing using the lower 10MHz showed significant improvement compared to tests of the upper 10MHz, although there continue to be interference concerns ... with certain types of high-precision GPS receivers, including devices used in national security and aviation applications. Additional tests are therefore necessary,” says the FCC in a Sept. 13 public notice.

LightSquared says the FCC’s notice has “acknowledged ... the significant improvement achieved” with its modified network and is consistent with the letter filed by the National Telecommunications and Information Administration (NTIA) with the FCC ... establishing a path forward for LightSquared through further targeted testing.

While acknowledging that “LightSquared’s recent proposals also represent progress toward addressing future interference issues,” the Save Our GPS coalition says, “We agree with the FCC’s conclusion that significant unresolved interference issues remain and that further testing is needed to determine if those issues can be resolved.”

NTIA has requested that the additional tests be limited to personal and general navigation receivers, and that testing and analysis be completed by Nov. 30.

Suspicious of White House pressure to push through LightSquared’s proposal to boost the Obama administration’s national broadband plan, Rep. Austin Scott (R-Ga.) pressed NTIA Associate Administrator Karl Nebbia on the reasons for limiting the testing.

Nebbia said that, while LightSquared is funding development of filter and antenna mitigation solutions for high-precision and timing receivers affected by “lower 10” interference, these will not be ready in time. “Why is the NTIA advocating so strongly for a private company?”

Scott asked. Nebbia denied that the request represented advocacy. “We are trying to move the ball forward on other points of concern rather than wait,” he said. “We will still have to deal with precision and timing receivers.”

-Graham Warwick, graham_warwick@aviationweek.com