Performance analysis of a channel load sensing protocol for CDMA packet radio networks with finite populations and variable length messages

An analytical and simulation performance evaluation is presented for a proposed multi-access protocol for data traffic in a packet radio network. The network employs direct-sequence code division multiple access (DS-CDMA) in a centralised channel load-sensing scheme with channel overload (collision) detection and blocking. A finite population, packetisation of variable length messages and partial message retransmission scheme are considered in the protocol. For a given maximum bit error rate due to mutual multi-access interference (MAI), an upper threshold (β) for the number of users allowed in the channel can be determined. This paper proposes a second lower threshold, α, to improve the system performance by adding an access control mechanism. The results show that an improved throughput/delay performance can be obtained by implementing a centralised load sensing scheme and dynamic channel control mechanism