Performance Modeling of Broadcast Polling in IEEE 802.16 Networks with Finite-Buffered Subscriber Stations

In this paper, an approximated model is proposed to analyze the performance of the contention based services via broadcast polling in unsaturated IEEE 802.16 networks with channel errors. The main idea is that each subscriber station with buffer capacity K can be treated as a M/G/1/K queue with service time determined by the backoff process of broadcast polling. Using this model, the normalized network throughput and the distribution of the packet delay are derived. This proposed analytical model is useful for performance evaluation and optimization of best effort or contention-based non-real time polling services. Our simulator written in C++ verifies the accuracy of the proposed analytical model. Furthermore, we show that the model gives good approximations for network performance with a more realistic bursty arrival process at light load, while providing conservative performance measures at medium and high loads.

本文提出了一种近似模型，用于分析在存在信道错误的非饱和IEEE 802.16网络中基于竞争的广播轮询服务的性能。其主要思想是，每个具有缓冲区容量K的用户站可被视为一个M/G/1/K队列，其服务时间由广播轮询的退避过程决定。利用该模型，推导出了归一化网络吞吐量和分组延迟的分布。所提出的分析模型对于尽力而为或基于竞争的非实时轮询服务的性能评估和优化是有用的。我们用C++编写的模拟器验证了所提出分析模型的准确性。此外，我们表明，该模型在轻负载下对于具有更符合实际的突发到达过程的网络性能给出了良好的近似，同时在中高负载下提供了保守的性能度量。