A Study on Smart Media Access Control Protocol for High Speed Wired and Wireless Networks

• Main Authors: Chih-Chiang Wu, 吳志強
• Other Authors: Sheu Shiann-Tsong
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/56480399278887726690

博士 === 淡江大學 === 電機工程學系 === 90 === Recently, the Internet has been growing at a very high rate. Many technologies are developed to match the fast growing of service requirements in Internet. Optical networks and wireless networks are two important technologies for networking industry. Optical network has many advantages, such as high bandwidth, low bit rate, and low interference. Advantages of Wireless networks are high mobility and convenience. Characteristics of optical networks and wireless networks are much different from traditional wired networks, many original media access control (MAC) protocols used in traditional wired networks can not be migrated to optical networks and wireless networks directly. Therefore, developing smart and efficient MAC protocols for optical networks and wireless networks is an important issue. In the first part of this dissertation, A simple and efficient compression strategy is proposed to reduce total switching time and to meet the high speed switching performance. First, many relative works about photonic ATM switch are described. Then, many detailed descriptions of each block of smart photonic ATM switch are provided. This dissertation proposes a compression decision algorithm to determine whether to perform compression or not, and to decide timing of switching each ATM cell. This dissertation also provides the saturated throughput analysis of proposed system. According to the results of analysis, we can find that the performance of system can be improved significantly by applying a few compression ratios. Some simulations are performed to investigate how the average queueing delay (AQD) is affected under different numbers of compression ratios and different network loads. After that, the switch size and the network load under a specified compression ratio are considered. Finally, how the AQD is affected under different frame sizes and different network loaded under a specified compression ratio is also be investigated. The simulation results show that the proposed system will work well even the compression ratio is 0.8 only. In the second part of this dissertation, a new MAC protocol for improving the traditional CSMA/CD protocol is provided. This new MAC protocol allows active stations to contend/reserve channel capacity by sending requests during a successful transmission frame. Some bits of frame checking sequence are provided as a interruption region. This idea improves the system performance while keeping the minimum overhead. A algorithm is proposed to descript the operation of this protocol. The throughput and delay are analyzed, and some useful equations are obtained. Many system parameters are compared to investigate the effects of them. In the last of this part, some simulations are performed to evaluate the performance of proposed MAC protocol. The simulation results show that the proposed protocol has better performance than the traditional protocol. The third part of this dissertation proposes a smart error checking scheme and design an adaptive cell checking controller for wireless ATM networks. The detailed descriptions of the protocol and relative parameters are given. An algorithm is provided to implement the functions of discrete cell error checking. The proposed controller can find out erroneous PDU and drop all remaining cells as early as possible. Therefore, more useful spaces in buffer can be released and the performance of wireless ATM networks can be improved. The removable percentage of an erroneous PDU by the proposed controller is analyzed. Finally, some simulations are performed. Simulation results show that compared with a conventional packet drop scheme, the proposed controller can achieve superior network utilization while keeping the minimum overhead in WATM networks.