A multicast approach for exchanges between co-operating mobiles in an 802.11 WLAN

We were interested here in wireless communications for industrial applications, in particular applications that need time-critical exchanges between stations. The communications are produced in an IEEE 802.11 WLAN with infrastructure. To respect the time constraints, we present here a particular mechanism managed in the access points. We propose to emulate broadcasting between entities taking part in the same co-operation (multicast) while managing in the access points copies of data to be exchanged. To preserve the IP traffic, we plan to use the concept of container in order to carry the different types of traffic. We take as a starting point the PCF mode that sends requests in turn to the stations. The results obtained concern the data updating mechanisms which allow cooperating entities to make use of multicasting.