Last Thursday, the FCC released a public notice that seeks comments on a final joint working group report on the potential of the proposed LightSquared LLC system to interfere with global positioning system (GPS) operations, as well as on the company’s revised plan to operate on lower L-band channels that are less likely to interfere with GPS users. Signaling the importance of LightSquared’s plan to launch a national wireless broadband network that will operate on mobile satellite service (MSS) and ancillary terrestrial component (ATC) spectrum in the L-band, the FCC issued its request for comments on the same day the working group report and revised spectrum plan were filed with the agency. Compiled by LightSquared and representatives of the GPS community, the working group report concedes that LightSquared’s initial plan to operate on 10 MHz of spectrum in the upper portion of the L-band is not currently feasible as such operations would “adversely affect the performance of a significant number of legacy GPS receivers.” Conversely, LightSquared stressed that its revised proposal to operate in the lower portion of the L-band would not affect the performance of 99.5% of GPS receivers, adding that tests performed by the working group in the lower L-band “establish conclusively that GPS receivers in practically all mobile phones and personal navigation devices can be expected to function without any appreciable impact.” With respect to precision GPS devices that may be impacted by LightSquared’s lower L-band operations, LightSquared said it would work with Inmarsat to ensure that such devices receive MSS augmentation signals on “safe” L-band channels that are isolated from LightSquared’s planned terrestrial operations. Although LightSquared predicted that interference issues would be “resolved by good data, smart engineers, and good-faith problem solving dialogue,” a spokesman for the Coalition to Save Our GPS voiced skepticism, observing: “you have to view any statements in the report about what will work in light of what it thought would work in the past.” Though maintaining that LightSquared will not be allowed to commence operations until interference concerns are resolved, an FCC spokesman emphasized that “our nation cannot afford to let [LightSquared’s L-band] spectrum go underutilized.”