ssover of patent value and personnel with XM radio. 16.27 Global Positioning MEOS at L Band GPS, Galileo and Glonass Table 16.10 referenced earlier summarized the global positioning MEOs. The US-managed GPS satellites have a 7.5-year design life, but satellites are lasting 12 years. Galileo is a European initiative with coverage, positioning accuracy and satellite lock times optimised for Europe. The satellites will have a 12- to 15-year design life. Galileo has the same downlink frequency as GPS and could be expected to be implemented as standard in future handset designs. Making Telecoms Work It is theoretically convenient to build an L band transceiver with GPS capability, though care has to be taken to avoid desensitisation of the GPS or Galileo signal within the handset. This appears at the time of writing to be the fatal flaw in the LightSquared business plan. GPS is of course now in a wide range of devices including the latest Sony 'Vita' PlayStation (Chapter 9). Most smart phones and of course all navigation devices, usually integrated with a GPRS receiver to capture traffic jam alerts to support optimised routing. It seems like we may be the last generation to be able to read a map. 16.28 Terrestrial Broadcast and Satellite Coexistence in S Band Table 16.11 summarised present and proposed S band hybrid satellite and terrestrial broadcast and two-way radio networks 16.29 XM and Sirius in the US - S Band GEO Plus S Band ATC XM7 and Sirius8 are two operators in the US providing MP3-quality audio radio for in-car and more recently in-flight entertainment. The two companies are presently in merger discussions. XM has four 15-kW geostationary satellites XM1 (Rock), XM2 (Roll), XM3 Rhythm and XM4 'Blues'. XM1 and XM2 have suffered some fogging on their solar panels. The satellites work with 1500 terrestrial repeaters that are each technically capable of delivering an ERP of 25 kW. Sirius has an additional three satellites also in geostationary orbit. The air interface is specified in a standard known as SDARS9 