無線區域網路傳輸頻寬保證演算法

Abstract

近幾年來，無線通訊漸漸地成為日常生活上便利的工具，不僅使電腦網際網路擁有移動性的便利，甚至可以應用在多種不同的裝置上。多媒體形式的傳輸應用也持續成長，從文字、語音到影像傳輸等；而傳統的盡力式傳輸模式已經無法滿足如此多樣化的應用及其服務需求，主要原因在於這些應用需要適當的服務品質保證，諸如頻寬、封包損失率以及最大傳輸延遲保證。 在本論文中，我們將提出延伸服務機制提供不同服務等級的頻寬保證。這個機制延伸了國際標準組織所制定的無線區域網路（IEEE 802.11）規範。此機制為一分散式機制，並且我們將對原本的規範做最小的改變以達到服務區分的目的。此延伸服務的效能將會以模擬的方式加以驗證。模擬的解果顯示此機制能在不同的網路環境下有非常良好的表現。

Wireless communications are an emerging technology and are becoming an essential feature in the last few years. Not only computer networks are becoming mobile, eventually each device will have a wireless interface. Simultaneously, multimedia is having an equivalent growth from data to voice up to video communications. Some of these applications impose requirements on some communication parameters, such as bandwidths, packet drop rates and delays in order to work properly. However, the traditional networks using best effort transmission mode to deliver data cannot satisfy the service requirements for these applications due to the lack of Quality of Service guarantees. In this thesis, we provide throughput guarantee with differential service by introducing the enhanced mechanism, which is an extension of IEEE 802.11 MAC protocol. With use of enhanced mechanism, the service of control will be fully distributed and Different service will be achieved by minimizing migration effort on current standard. The performance of proposed mechanism has been evaluated by simulation. Simulation results show the mechanism will behave well in different kinds of scenarios.