RADIO AND NETWORK COMPARISONS FOR MSBN AND GSM SYSTEMS IN A GEOSTATIONARY SATELLITE ENVIRONMENT

One of the most frequently debated issues in satellite communications concerns the comparison between time division multiple access (TDMA) a nd code division multiple access (CDMA) systems. Although, in our view , a general answer to this problem cannot be found, this paper present s comparisons of two systems utilizing the above-mentioned access tech niques, both from a radio and a network point of view. In particular, the mobile satellite business network (MSBN), (a CDMA system currently being developed by the European Space Agency (ESA) for general satell ite applications) and the full integrated extension to satellite syste ms of the global system for mobile communication (GSM) (the well-known frequency division multiplex (FDM)/TDMA pan-European mobile cellular system) are compared by taking, as the reference payload, the L-band l and mobile (LLM) satellite (a spot-beam geostationary satellite whose launch should take place at the end of 1997). Reasonable assumptions t ake into account the fact that, on one hand, the MSBN system is not co mpletely defined and, on the other, the GSM is applied in a context di fferent from the one specified by the European Telecommunication Stand ard Institute (ETSI). Performance comparisons are carried out in terms of flexibility and number of available channels for the same quality requirements, emitted power levels, propagation environment and interf erence levels coming from adjacent satellites. It is concluded that MS BN is more flexible than GSM and that, as regards capacity, an advanta ge of GSM over MSBN is present in the transportable mobile case, where as, in the vehicular mobile case, MSBN shows an advantage over GSM. (C ) 1996 by John Wiley & Sons, Ltd.