M. Alasti et N. Farvardin, SEAMA: A source encoding assisted multiple access protocol for wireless communications, IEEE J SEL, 18(9), 2000, pp. 1682-1700
This paper presents SEAMA, a source encoding assisted multiple access (MAC)
protocol, to integrate voice and data traffic in a wireless network. SEAMA
exploits the time variations of the speech coding rate, through statistica
l multiplexing, to efficiently use the available bandwidth and to increase
the link utilization. In each frame, SEAMA allocates bandwidth among calls
as needed. Ongoing calls are always assigned some minimum bandwidth to allo
w for coding of the background noise during silence periods. An embedded vo
ice encoding scheme is employed to allow the network to control the rate of
the calls during congestion by selectively dropping some of the less signi
ficant packets, thus causing a graceful degradation of quality. It is shown
that by employing an appropriate voice coding scheme and exploiting the ch
aracteristics of the source encoder in the MAC protocol, SEAMA almost doubl
es the capacity of the voice section compared to a circuit-switched network
, while practically maintaining the quality of voice traffic.