A Guaranteed QoS MAC Protocol of Wireless ATM Networks

• Main Authors: Chiou, Gea Yang, 邱繼陽
• Other Authors: Chen Wen-Tsuen
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/75660805238314232666

碩士 === 國立清華大學 === 資訊工程學系 === 86 === Wireless ATM has been proposed for next-generation personal communicationnetworks (PCN) to support the integrated multimedia communication services.Guaranteed quality of service (QOS) is required for the Wireless ATM networksto support multimedia communications. However, emerging standards, such as the IEEE 802.11 Wireless LAN, are designed to provide wireless access in a conventional way without considering QOS provision. In this paper, we presentan important system design issue for wireless ATM networks in general, is thedesign of an advanced medium access control (MAC) protocol for supporting allATM QoS requirements for heterogeneous traffic. In the past, the typical MAC protocols of wireless ATM are based on FDMA,CDMA and TDMA. Most previous MAC protocols in the area use an adaptive TDMAscheme, due to its ability to flexibly accommodate a connection's bit rateneeds by allocating more or fewer time slots depending on current trafficconditions. There are two main categories used in the TDMA scheme are"contention" and "reservation". These contention-based protocols (like IEEE 802.11) attain good performanceunder light traffic, basically due to the short delays when the number ofcollision is limited. The reservation-based protocols (like MDR-TDMA) are morecomplex and introduce some extra delays due to the required reservation phase.Their performance depends to a large extent on the scheduling mechanism usedfor the allocation of the available bandwidth. Thus, we propose a novel guaranteed QOS MAC protocol with Dynamic WeightedEarliest Deadline First with Save and Borrow (DWEDF/SB) scheduling mechanismfor wireless ATM network. The MAC protocol can provide low latency, fairnessthroughput, low cell loss ratio and efficient channel utilization for QoSguaranteed.