To: i-node who wrote (5290 ) 10/6/2006 6:01:53 PM From: pcstel Read Replies (1) | Respond to SIRI's current satellite configuration cost more than XM's, and delivers poorer signal to the receivers on the ground. You said otherwise and you are wrong. 5. Authority for three satellite system enhancements is requested by this modification application: (1) authority to increase the number of satellites from two to three, plus a ground spare; (2) authority to place three satellites into inclined and elliptical (non- geostationary) satellite orbits; and (3) authority to use the 4/6 GHz frequency band on a non- harmful interfering basis for telemetry, tracking and command ("TT&C"). We find that grant of Sirius' modification application will provide the public with an improved satellite DARS system that relies on fewer terrestrial repeaters and offers more channels within the existing spectrum allocation. The HEO design engendered numerous benefits to the listening public. First, the system improves service to subscribers in the northern United States by increasing the elevation angles to the receivers. Sirius’ originally proposed geostationary system would have served the northern third of the United States at an average elevation angle of 30 degrees. The HEO design ensures that at least one satellite is available at all times in this area to provide service at an elevation angle near 60 degrees. The higher elevation angle reduces path loss, lessening vulnerability to signal blocking, from buildings and terrain, and lowering susceptibility to shadowing and fading caused by trees and foliage. Second, the improved propagation and increased margin resulting from HEO configuration allows Sirius to offer more channels within Sirius currently operates about 140 terrestrial repeaters, while XM’s geostationary system is augmented by over 800 terrestrial repeaters, or five times as many as Sirius. Sirius proposes to construct is expected to be completed in the fourth quarter of 2008. SIRIUS FM-5 will also take advantage of advances in satellite design to improve service. It will be one of the most powerful satellites ever constructed, with an end-of-life power In addition, FM-5 is both compatible with the existing constellation yet designed with newer, more efficient transmissions that will augment total capacity and thus additional audio channels, plus next generation data and video services.
