Analysis of a random-access protocol under long-range-dependent traffic

ALOHA-type random-access protocols have been used as access-control protocols in wireline and wireless, fixed and mobile, multiple-access communications networks. They are frequently employed by the control and signaling subsystem of demand-assigned multiple-access protocols to regulate the sharing of a multi-access communications channel. The correct design and sizing of the random-access operated control/signaling channel is critical in determining the performance of these networks. Excessive delays in the transport of signaling messages (due to too many collisions and retransmissions) lead to unacceptable session-connection setup times. This is of particular concern when the message traffic is highly bursty. We investigate the performance behavior of a random-access protocol when loaded by bursty traffic processes. The latter often exhibit long-range dependence (LRD). We model the LRD traffic flows as multiplicative multifractal processes. The random-access protocol is modeled as an ALOHA channel with blocking. The burstiness of the traffic processes, rather than their LRD character, is the essential element determining the performance behavior of the protocol. When the loading-traffic process is not very bursty, the performance of the random-access channel can be even better than that exhibited under Poisson traffic loading; otherwise, performance degradation is noted. We demonstrate the impact of the selection of the protocol-operational parameters in determining the effective performance behavior of the random-access protocol.