A Study of Bandwidth-Perception Management Mechanisms in IEEE 802.16 Networks

摘要

Bandwidth request-grant mechanisms are used in 802.16 networks to manage theuplink bandwidth needs of subscriber stations (SSs). Requests may be sent bySSs to the base station (BS) by means of several mechanisms defined in thestandard. Based on the incoming requests, the BS (which handles most of thebandwidth scheduling in the system) schedules the transmission of uplinktraffic, by assigning transmission opportunities to the SSs in animplementation-dependent manner. In this paper we present a study of somebandwidth allocation issues, arising from the management of the perception ofsubscriber stations' bandwidth needs at the base station. We illustrate how thebandwidth perception varies depending on the policy used to handle requests andgrants. By means of ns-2 simulations, we evaluate the potential impact of suchpolicies on the system's aggregate throughput when the traffic is composed ofBest-Effort TCP flows.