一种基于无线多媒体业务的可升降级QoS动态带宽分配与优化策略

无线多媒体网络中的业务包括话音、流媒体、交互类和背景类业务4种，除话音业务外其余3种业务都是可变比特速率业务。对该网络用户资源分配(主要是带宽的分配)若采用传统的固定分配方法，必定陷入资源利用率低下和用户QoS得不到保障的两难境地。该文提出了一种基于无线多媒体业务的动态带宽分配与优化策略，在保证用户QoS的前提下，尽可能提高资源利用率。该文分别从网络和用户两个角度考虑，通过系统容量、业务阻塞率、数据延迟、流媒体的实际传输比和VBR业务综合服务等级等参数，对可升降级QoS无线多媒体网络进行了仿真分析，结果表明，对比传统的网络资源管理策略，该策略大大改善了系统的性能，提高了系统资源利用率。

A Changeable QoS Dynamic Bandwidth Allocation and Optimization Strategy Supporting Wireless Multimedia Traffics

There are four traffic classes in wireless multimedia network, including conversational class, streaming class, interactive class, and background class, while three of them are Variable Bit Rate (VBR) traffic except conversation class. It will fall into a dilemma if conventional resource allocation methods are adopted (especially for the bandwidth allocation methods). In this paper, a dynamic bandwidth allocation scheme is proposed for packet switched wireless multimedia networks. The scheme could guarantee users' QoS, while the utility of resource could be improved. Using these models, the effects of the changeable QoS dynamic bandwidth allocation and optimization strategy are evaluated from both points of view of the networks and users. Simulation results are presented to demonstrate the performance of the proposed scheme in terms of system capacity, blocking probability, delay, practical transmission ratio of video traffic, and the Integrated Grade of Service (IGoS) of VBR traffic. Compared with the conventional scheme, the proposed scheme can greatly improve the system performance and resource utility.