Bandwidth estimation and distributed traffic regulation in wireless local area networks

In this paper, we introduce distributed traffic regulation for wireless local area networks (WLANs) operating in ad hoc mode. We use the concept of service curve to determine the minimum guaranteed service given to a backlogged connection. In a WLAN, the service curve depends on the number of active nodes, their traffic load in active periods, and the back-off procedure used for contention resolution. We will show that service curve can be used for distributed traffic regulation. We use some of the data packets, denoted as the probing packets, to estimate the service curve. The call is accepted if the service curve is higher than a preselected threshold, called the universal lower bound. The universal lower bound is independent of the number of nodes and traffic fluctuation and acts as a worst-case reference point for the network performance.