A Simulated Multi-Traffic approach for Polling WLAN systems

By considering a wireless local area network (WLAN) with centralized topology, performance simulations of a multi-traffic system, taking into account voice and data, are presented. The medium access protocol is based on a token passing, managed by a HUB, with control and relay functions. A constant cycle time has been fixed, due to the voice time constraints, which contains a former station polling for the isochronous traffic, followed by a succession of asynchronous subcycles which spend the left time. The first asynchronous subcycle is based on a reservation mechanism, performed by the wireless stations in the isochronous one; the reservation procedure for the sub- sequent asynchronous subcycles is performed in each preceding one. In this way the isochronous traffic delivery is always guaranteed with a deterministic delay, a priori fixed. The merit figure selected for the performance investigation is the asynchronous access time, function of the network throughput and of the system parameters.