Abstract-An ad hoc wireless network is an autonomous selforganizing system of mobile nodes connected by wireless links where nodes not in direct range communicate via intermediate nodes. Modern wireless devices, such as those that implement the 802.11b standard, utilize multiple transmission rates in order to accommodate a wide range of channel conditions. We provide a general theoretical model of the attainable throughput in multirate ad hoc wireless networks. This model is derived from a detailed analysis of the physical and medium access control layers. The traditional technique used by most existing ad hoc routing protocols is to select minimum hop paths. These paths tend to contain long range links that have low effective throughput and reduced reliability. We present the Medium Time Metric (MTM) that selects optimal throughput paths and tends to avoid long unreliable links. Our NS2 simulation environment consists of a high mobility 802.11b network with many simultaneous TCP connections. These simulations show that our MTM yields an average total network throughput increase of 20% to 60%, depending on network density, over the traditional hop count metric. By combining the MTM with the Opportunistic Auto Rate (OAR) protocol, an increase of 100% to 200% is obtained over the traditional route and rate selection techniques. This work stresses the importance of inter-layer communication in wireless networks. Our results show that link rate information from the medium access control layer can be utilized by routing protocols to significantly increase network performance.
In REF the authors proposed a new network metric the medium Time Metric (MTM), which is derived from a general theoretical model of the reachable throughput in multi-rate ad hoc wireless networks.
High Throughput Route Selection in Multi-rate Ad Hoc Wireless Networks
WONS
Computer Science