Guaranteed quality-of-service wireless access to ATM networks

In this paper, we study the problem of wireless access to ATM. We consider three classes of ATM sources: constant bit rate (CBR), variable bit rate (VER) and available bit rate (ABR). We propose a polling scheme with nonpreemptive priority. Under such a scheme, we derive sufficient conditions such that all the CBR sources satisfy their jitter constraints and ail the VER sources satisfy their delay constraints. The remaining bandwidth is used by the ABR sources, for which we adapt a random access scheme proposed by Chen and Lee (1994). For this random access scheme, we derive the throughput-offer load characteristic, and thus the capacity. Based on this, we propose adaptive random access schemes that track the offer load to its optimal value. Our simulations show that our adaptive schemes maintain a high throughput with respect to the whole range of system load.