Date Added: Aug 2011
In this paper, the basic idea of PCF is applied to solve hidden terminal problem and improve the QoS parameter. When collisions occur at a node, the node considers that there is more than one node means to transmit data to it. Then this node gets control of the channel. It polls all of the one-hop neighbor nodes in its polling list to enquire whether it has data to transmit. This mechanism greatly decreases the unnecessary contending time in bakeoff mechanism. More time is used to transmit useful payload. As a result, channel utilization is enhanced greatly.