Résumé: This paper deals with low earth orbit mobile satellite systems (LEO-MSSs) belonging to third-generation mobile networks and proposes a novel packet-access scheme suitable for a hybrid time-code wide-band air interface. This medium-access control (MAC) protocol is a modification of the packet-reservation multiple-access scheme with hindering states (PRMA-HS) and is called code-division PRMA-HS (CD-PRMA-HS). Each mobile terminal that needs to transmit makes random accesses on available time-code resources until it receives a positive acknowledgment from the satellite. Both real-time voice and Web-traffic sources have been considered in our LEO-MSS scenario. An in-depth analysis of the random-access phase has been carried out, thus, identifying the conditions that allow a good CD-PRMA-HS behavior. Finally, a performance analysis has been developed in order to evaluate the quality of service parameters for both voice and Web-traffic sources.

Langue: Anglais