Abstract: A class of adaptive hybrid multiple access protocols for a single channel, time division communications network dynamically switches among contention (Aloha), reservation, and fixed assignment (TDMA) protocols as a function of the traffic on the channel. This class of protocols is referred to as "Aloha-Reservation-TDMA" or "ART" class protocols. Within the ART class, a subclass of protocols is defined for satellite communication networks. This subclass is referred to as "Adaptive Satellite Hybrid Access" or "ASHA," and two examples of protocols within the ASHA subclass are described to show the viability of the ART class protocols. These protocols are referred to as ASHA1 and ASHA2. Both the ASHA1 and ASHA2 protocols combine the features of S-ALOHA, TDMA-Reservation and TDMA protocols. The ASHA1 protocol transmits reservation information when the Aloha protocol is selected, but the ASHA2 protocol does not.