| With the rapid development of wireless communication technology, the Wireless Local Area Network (WLAN) as an important branch of mobile communications has successfully integrated the social life, and vastly improved the way people live. The MAC layer is the basis of reliable WLAN data transmission, has a decisive influence on the whole network performance. Therefore, the impact on the performance of the wireless LAN MAC layer protocol analysis and different business performance transport protocol for the MAC layer has been one of the hottest areas of computer and communications research.The MAC protocols of WLAN standard adopt the IEEE802.11series standard. In the network terminal obtains the right to use the wireless channel by means of competition, the MAC layer data transmission is mainly based on DCF model protocol specification. This paper analyses the modeling of DCF protocol implementation process. Considering the actual network is not always in a saturated state, this paper proposes a modified mathematical model. This model increases the analysis of the scale of terminal data and the limit of MAC queue length, and considering the situation of the back-off timer frozen and retransmission times. Based on the proposed improved model, we analyze the performance of the WLAN such as throughput, delay and possibility of packet loss. Through MATLAB and NS2on wireless LAN DCF model theoretical and the practical simulation, we verify the proposed model’s reasonability. Then, we combine the process of DCF model with two common transport layer protocol (UDP and TCP) implementation process, propose the network theoretical analysis model under UDP and TCP transmission and compare the two kinds of performance of the protocol on the MAC layer. At last, we apply WLAN to CBTC data communication system, analyze the feasibility and network performance of CBTC system using WLAN. |
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