Fixed Satellite Service (FSS) needs independent spectrum, Hughes ...

or unlicensed basis. Hughes said it believes concerns are particularly applicable to FSS. Issues of terrestrial/satellite spectrum sharing are acute in FSS bands because of way their spectrum is shared on co-channel basis among multiple satellite systems, Hughes said. Satellite networks are spaced 2 degrees apart, which means that any attempt by one entity to implement terrestrial network in FSS band has potential to create interference to large number of satellite systems operated by other entities, filing said. For that reason, FSS stands in contrast with SDARS and certain Mobile Satellite System (MSS) bands where satellite licensees have exclusive assignment of spectrum and don’t share spectrum on co-frequency basis with other satellite systems. In those cases, it may be possible for satellite licensee to implement terrestrial component to network that’s not expected to adversely affect other satellite users in same frequency band, Hughes said. Potential for terrestrial interference into FSS spacecraft is concern of many terrestrial transmitters, such as LMDS or 39 GHz broadband services deployed by companies such as Winstar. By mandating FSS, systems accept certain level of noise from terrestrial operations but it constrains deployment of more advanced satellite technology and could preclude development of more sensitive receivers that would allow use of smaller, lower- powered, lower-cost earth terminals, Hughes said.