| 摘要 |
<p>A method employing a demand assigned multiple access protocol for transmitting data on a processing satellite uplink and downlink in a satellite communications network, where multiple users are assigned to a common data transmission resource as part of a sharing set. A DAMA processor (32) on the satellite maintains a reservation log which identifies the uplink time slots in a non-contentious main flow resource that are currently reserved by the members of the sharing set, and allows the members of the sharing set to reserve the available time slots. To reserve a time slot on the main flow resource for the non-contentious transmission of data, a user of the sharing set will transmit a reservation request to the satellite on a contentious control flow resource (14). If a return message is not received (18), the user knows that the reservation request collided with another reservation request, and a retransmission strategy is employed (20). When the DAMA processor (32) receives the reservation request, it decides whether to grant, deny or delay the request based on predetermined criteria, including whether the requesting user already has a reservation (36), the length of the reservation request (40), the congestion state of the destination downlink port, and other flow control parameters. The DAMA processor (32) will issue a reservation grant message to the requesting user that includes the time, frequency and length to send the data on the main flow. When the requesting user receives the reservation grant message (16), it will then wait for its reserved time slot (22) to transmit the data on the main flow resource (24). <IMAGE></p> |
