AAL2分组话音复接器带宽分配算法的研究

Bandwidth Allocation Algorithm Suitable to AAL2 Packet Voice Multiplexer

本文根据分组话音业务的特点 ,结合分组话音业务服务质量的要求 ,特别是分组丢弃概率和平均分组排队时延的要求 ,研究AAL2分组话音复接器带宽分配算法 .得出结论 :对于无比特丢弃的AAL2分组话音复接器 ,按平均速率分配带宽基本上可以满足分组话音业务服务质量的要求 ;如果适当降低ATMVC的带宽利用率 ρ(例如 :令 ρ=0 9) ,则可以进一步提高话音质量 ,获得令人满意的话音 ;对于带比特丢弃的AAL2分组话音复接器 ,按平均速率分配带宽 ,可以很好地满足分组话音业务服务质量要求 ,获得较高质量的话音 .计算机仿真证实了上述结论是正确的 .

This paper investigates bandwidth allocation algorithm suitable to the AAL2 packet voice multiplexer, which takes into consideration the features and quality of service of AAL2 packet voice. A conclusion is drawn that average rate bandwidth allocation can meet the requirements of AAL2 packet voice multiplexer without bit dropping. If we reduce the ATM VC (Asynchronous transfer mode; Virtual Channel) bandwidth utilization (e.g.ρ=0.9), we can further improve voice quality. As far as AAL2 packet voice multiplexer with bit dropping is concerned, average rate bandwidth allocation can well meet the requirements of the quality of service of packet voice. Computer simulation results obtained are in good agreement with the conclusion.