Exploring Service and Buffer Management Issues to Provide Integrated Voice and Data Services in Single and Multi-channel Wireless Networks

摘要

Service and Buffer Management techniques can be used to ensure Quality of Service (QoS) for different traffic flows according to some specific policies. In this study, a single buffer queuing system is considered to model single and multi-channel, homogeneous wireless network systems such as wireless local area networks (WLANs) and cellular networks. These systems are now being used to carry both voice and data traffic and hence it is important to optimise these systems in an attempt to reduce the blocking, and minimize the latency to acceptable ranges. Since voice packets are delay sensitive, they have the priority to receive service. Also they require smaller buffering capacities, since the response time to voice requests should be below specific values. In addition, in order to reduce retransmission on reliable data connections, data packets are not usurped by incoming voice packets. In this paper, a mathematical analysis of this scenario is explored. The proposed mathematical model is represented by two dimensions, one for incoming voice packets and one for data packets. The models proposed show that it is possible to store incoming voice packets in the queue in case the channel or channels are busy. Both voice and data packets have finite buffering. Incoming voice packets are blocked when the voice buffer or the common queue is full. Therefore there is an added blocking probability of voice due to the presence of data packets in the system when the common queue is full. The analytical model is validated using simulation. The system proposed attempts to provide minimum delay for voice while reducing the disruption to reliable data connections. Numerical results show that, it is possible to attain these goals with reasonable buffer sizes. This study is useful for understanding the trade-offs and thresholds of single and multi-channel systems with voice and data traffic.