Token enabled multiple access (TEMA) for packet transmission in high bit rate wireless local area networks

We illustrate a novel wireless local area network multiple access control (WLAN MAC) protocol whose allocation policy adopts a strategy similar to the token ring: the mobile stations access the channel upon receiving the token and release the channel by passing the token to the next user. The traffic is divided in two classes: guaranteed bandwidth (GB) and best effort (BE). The base station indirectly controls the traffic access by allotting the tokens and the bandwidth is shared by the same users with a decentralized contention-less protocol in the case of the GB users and on a contention basis for the BE users. The MAC protocol proposed the physical layer adopts a multicarrier code division multiple access multiplexing technique, which mitigates the linear distortions of broadband transmission and allows one to divide the frequency and time resources in elementary units that can be associated to the ´token´. The specification on the average and peak delay and rate are guaranteed by limiting the number of users passing the token and fixing a deadline to release the token. At the same time, similar to a reservation based protocol, the token strategy avoids collisions and is able to guarantee efficiently the integrity of the transmitted data.