Understanding Of The Ieee802.11 Standard Wireless Router And Dsss Physical Layer Simulation Realization

Network technologies including LAN and WAN have reached full development up till now. Originally, network, depending mainly on media of copper or fiber cables to consist LANs, will be confined under circumstances, thus gestated the wireless network of computers. In the near future, the whole computer network will become a combination of wired and wireless network. At present, application of the WLAN technology to the interlinkage of networks lies in modes of point to point and wireless-bridge, which are essentially a kind of area network technology with simple and agile access and fit for only small-scale networks . The wireless router , however, has such merits as selecting the routes, access management and better abilities to form a network. With the protocol of the wireless area network and the ability of selecting the routes , it enlarges the wireless network and creates more agility and variety. At the same time, wireless router can overcome the blindness of the wireless-bridge and decreases broadcast communication through wireless channels, whose utilization is greatly increased. The IEEE802.il standard is of the same serial as IEEE802.3 which are compatible with each other in many aspects. So the IEEE802.il standard is most suitable for the construction of the PHY layer and the MAC sublayer of a wireless router. In the second chapter, the principles and aims of the wireless router are explained, then the structure planning of the hardware and the protocol, and the introduction of varieties of wireless area networks in the end. In the third chapter there is introduction of the IEEE802.il standard. For the MAC sublayer , focuses are put on the unique CSMA/CA mechanism of this standard; for the PLCP sublayer, there is much introduction of the structure of the DSSS PHY frame and primitives of this layer; for the PMD sublayer, rules of DSSS PMD are explained. The last chapter is simulation of the PHY layer of the IEEE802.il standard. Explanation is made in detail about the transmit-receive mechanism: first, send a MAC frame by the PHY layer, and then it is transmitted to the MAC sublayer after being received. In this way , a substantial foundation is laid for the further development of the wireless router.