"However, due to the Administration’s commitment to increased access to broadband, the investment was merited, but given the results we reviewed, further investment cannot be justified at this time," he said.
LightSquared has invested billions of dollars to launch a nationwide wireless broadband service, but the company ran into problems last year when tests showed its planned network could interfere with GPS devices.
The company says the problem is that GPS receivers are poorly designed and are receiving signals from outside their designated frequency bands.
Porcari said testing confirmed that LightSquared's signal is not bleeding into the GPS band, but he said GPS receivers are too sensitive too filter out LightSquared's powerful cell towers operating on nearby frequencies.
Representatives for the commercial airline industry also testified that LightSquared's network would cause widespread problems for their GPS devices.
"LightSquared was denied a seat at the witness table today," a LightSquared spokesman said.
"Despite repeated requests, we were told there was no need to testify because LightSquared was not the subject of the hearing. We are dismayed but not surprised to hear today that this hearing was little more than a one-sided trial of LightSquared in absentia. It’s outrageous that a congressional hearing set up to examine factual issues was only focused on one side of the story — a side of the story supported by commercial GPS makers who designed faulty devices that depend on using spectrum licensed to LightSquared."
The Federal Communications Commission (FCC) granted LightSquared a conditional waiver to move forward last year, but officials now say the company will have to fix the interference problem before receiving final approval to launch its network.
Some Republicans have questioned whether the FCC and the White House have shown inappropriate favoritism to LightSquared. Sen. Chuck GrassleyChuck GrassleyGrassley calls for federal prosecutor to probe botched FBI Nassar investigation Woman allegedly abused by Nassar after he was reported to FBI: 'I should not be here' Democrat rips Justice for not appearing at US gymnastics hearing MORE (R-Iowa) has vowed to block President Obama's two FCC nominees unless the agency releases internal records on its review of the company.
LightSquared has until mid-March to secure regulatory approval or it risks losing a multibillion-dollar contract with Sprint.