The Research Of Roaming And Switch Of Wireless LAN

Wireless LAN is a Lan which uses wireless channels to transfer information, result from the combination of computer network and wireless communication. WLAN uses wirless multiple access as the transfer medium, it can server as what the Wired LAN do. Whenever and wherever are people able to obtain access to wide-band network through WLAN.At present WLAN has unchained the cable, however, the terminal could access the network only when it moves in a certain area. WLAN is good at providing data service, however, it doesn't support the voice and video well which require real-time handling. The reason for this is that WLAN doesn't support well the switching and roaming of a STA from one Access Point to another. Voice over WLAN is a popular topic today, it is a new service of WLAN, and will be widely used all around the world. As refer to technology, voice service is more sensitive than data service. VoIP can transfer voice by using TCP/IP protocols, and We can access Internet through WLAN. VoWLAN is something that can provide the VoIP service through WLAN.Throughout this paper, reference is made to the application of VoWLAN. In order to make the WLAN's switching and roaming more smoothly, this paper has made improvement of the load balance of IAPP, as well as pre-authentication is introduced.Finally, in order to meet the requirement of completely roaming, mobile IP and MESH may be renewed.