The Research Of United Controlling Mechanism Of Auto-adapted Frame Length And The Priority Queue

As an emerging communication technology, the wireless network communication becomes increasingly significant in the daily life. In recent years the wireless local area network technology, in particular, is developing rapidly, however, when compared to the traditional Ethernet, its performance is still not competitive enough. That explains the reasons why the improvement of the optimized wireless local area network performance is of such a great significance. In the document 1, the author points out that it is adversely not only to the data service of high effectiveness but also to the voice service of quality, due to the anomaly problem result from the instability of the wireless channel. This essay intends to expand the prerequisite of the Markov chain theory, on the basis of the analysis of performance anomaly in the document 1 and the analysis of saturated Markov chain performance in document 2, thus to render the Markov chain theoretical analysis model even more suitable to the reality wireless current capacity model. Then it carries on the expansion of the Markov chain analysis theory, thus make it able to analyze the system the time delay, the jitter as well as packet loss rate under the prerequisite of the analysis system of throughput. The above theory expansion provides the theoretically preparatory work for later application of the voice and data service to the wireless local area network. Meanwhile through the tentative analysis of the Markov chain theory, this essay indicates the proper solution of the imbalanced performance problem in the document 1. In third chapter, the author proposed a kind of auto-adapted frame length and priority queue's union control mechanism based on the package of size, has realized this union control mechanism in NS2 and completed a series of simulations work through to the NS2 simulator code expansion. At the same time, it helps to obtain the system throughput handled, the time delay, the jitter, packet loss rate and so on the effective analysis result, through the analysis of the analogue result Trace document. The analysis result indicates that this union control mechanism can effectively reduces the time delay of the high speed pitch point and the jitter, under the premise of the system throughput handled enhance, but it exerts little influence to the system of total time delay. This union control mechanism only carries on the certain modification of the logical link control level; "therefore it is capable to coordinate the prevailing entire series IEEE 802.11 Agreements.