| Summary: | 碩士 === 國立成功大學 === 資訊工程研究所 === 88 === The standard of wireless LAN MAC layer is almost following the IEEE 802.11 protocol standard. The IEEE 802.11 protocol has defined a PCF mechanism to provide some capability of real-time, but it would not fit in with the actual requirement of multimedia application. We need an enhanced MAC protocol to satisfy the requirements.
We will make a mapping from the requirement of multimedia to the multi-channel access with synchronization mechanism. The multi-channel access with synchronization mechanism could transfer many different streams according to sender request before the transmission begins. It also provides synchronization between each channel by the jitter parameter.
The allocation method is either static allocation or dynamic allocation. The well knows method of static allocation is TDMA, FDMA, and CDMA. The method we need to satisfy the multimedia application is more than that. To consider the QoS parameter to transform the multimedia stream to different priorities. After priority model has been built, we use negotiation approach to make the work of admission control and resource management.
The multimedia streams will be divided into three types according to our consideration. There are hard-QoS stream, soft-QoS stream, and random access stream. The multimedia requirements will choose to use any of them.
In order to simplify the description of multimedia characteristic, we should make the QoS parameter into quantification by using smooth model. Any sender should follow the smooth model to provide the QoS streams it need. We have defined the terms of smooth model as {ni, Ti, Pi, Wi}.Since we have completed the analysis of QoS parameter, it is easy to make sure of admission control and scheduling with synchronization.
To implement the MAC layer protocol, we need coding in both firmware of the wireless card and device driver corresponding OS. The device driver on the windows operation system is coding with DDK. We have to make the version of windows and DDK is corresponding.
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