Cross Layer Aware Adaptive MAC based on Knowledge Based Reasoning for Cognitive Radio Computer Networks

In this paper we are proposing a new concept in MAC layer protocol design for Cognitive radio by combining information held by physical layer and MAC layer with analytical engine based on knowledge based reasoning approach. In the proposed system a cross layer information regarding signal to interference and noise ratio (SINR) and received power are analyzed with help of knowledge based reasoning system to determine minimum power to transmit and size of contention window, to minimize backoff, collision, save power and drop packets. The performance analysis of the proposed protocol indicates improvement in power saving, lowering backoff and significant decrease in number of drop packets. The simulation environment was implement using OMNET++ discrete simulation tool with Mobilty framework and MiXiM simulation library.Comment: 8 page

Enabling limited traffic scheduling in asynchronous ad hoc networks

We present work-in-progress developing a communication framework that addresses the communication challenges of the decentralized multihop wireless environment. The main contribution is the combination of a fully distributed, asynchronous power save mechanism with adaptation of the timing patterns defined by the power save mechanism to improve the energy and bandwidth efficiency of communication in multihop wireless networks. The possibility of leveraging this strategy to provide more complex forms of traffic management is explored

Overview of 802.11 Power Saving Mechanisms

This paper presents overview of 802.11 power saving mechanisms with priority to Distributed Coordination Function (DCF). In the 802.11 power saving mechanism, time is divided into beacon intervals. When each beacon interval starts, each node periodically wakes up for a time period called ATIM window. Synchronization is required between nodes so that they remain active at the same time. During ATIM window, nodes exchange control packets to determine whether they need to remain active for the rest of the beacon interval. The size of the ATIM window has a major marked effect on energy savings and throughput achieved by nodes. In the mechanism, the nodes that are involved in the data communication remain active and other nodes go into doze mode