A Distance-Aware Power Management In Manet With Directional Antennas

The usage of directional antenna in wireless ad-hoc networks has been known to increase the performance of power control during communication scenarios. It also gives a good system throughput thanks to the reduced interferences due to the fact that it can adaptively select radio signals of interest in specific directions, while filtering out unwanted interference from other directions. In power control, minimizing the transmission power of two nodes equipped with directional antenna is a challenge. In this thesis, we concentrate in a particular cross-layer designed for three different topologies:sparse, dense and cluster. By inserting the impact of mobility within these three topologies, we found that system gives a very low throughput and moreover the gap created by the moving nodes during a communication drains the wastage of power.The research community has done a lot of work to suggest potential ways of power control in ad-hoc networks. Some of them have considered a specific problem occurred in wireless Ad hoc networks with directional antenna. Network can be loosely classified into two categories, power controlled topology management and power aware routing Power controlled topology management schemes try to find lowest transmission power level for each link as far as network-wide connectivity is guaranteed. The authors has designed a cross layer based on the changing of a topology. The transmission power control will be used if the nodes, which constitute the network, are grouped according to a sparse, cluster or dense topology. In a case of sparse topology, The Locally Aware Protocol is used. Since the network is not cram-full, the sender sends a RTS with a maximum power to make sure that the signal strength is high enough to maintain the SINR level at the receiver in case of interference;the protocol used is thus locally aware. The second protocol is globally aware since the node density increases. It helps to maximize the throughput when a transmitting node sends an RTS to the receiver successfully;the receiver piggybacks the SINR information in the CTS frame, which can be further used to decide the ideal transmitting power at the transmitter. The third approach solves the problem of Interference by using a Power Management Protocol. It has been design to work properly in a cluster design topology. If all the nodes were to transmit at a random level of transmission power, the network throughput would degrade since the neighboring nodes would cause interference. It would be appropriate in such a scenario to restrict the power levels of different groups. Each member in a group uses the same power level. Different groups use different power levels depending on the size of the group. Since new members may be added to the cluster and old members might leave, a special node called the Cluster Head (CH) is elected. This node has knowledge of the topology of the network. It calculates the minimum required power so that all node pairs can communicate. This value is beaconed after short durations so that all the nodes have the updated information and are transmitting with only the required power. This paper has not considered the mobility scenario. It is a good idea to have a cross-layer design which can adapt to some specific changing of the network topology but if the nodes are moving within the network, the interference may increase thus the SINR at the Receiver node may not be enough for him to receive the signal. These approaches didn’t consider this aspect.Our paper is thus based on these approaches of power management with directional antenna and we examine the problem of mobility in MANET with Directional antenna; we design a distance aware scheme that solve the problem caused by the movement of nodes. Our first solution is to allow the transmitting node to be aware of the distance separating it with the receiver so that it can adjust or use less transmission power during the communication The second approach to solve the near far problem caused by the mobility of nodes is to calculate the different transmission powers of all paths from the transmitter to the receiver node. This method helps to choose what we will call Alternative Transmission Power (ATP). To overcome the problem of power-consumed wastage, we have designed a scheme called Alternative Transmission Power (ATP), a distance aware scheme and an updating information scheme. These schemes relied on cross-layer design protocol that helps to avoid collision. Simulations and results show that our schemes can improve at24%the throughput and reduces at13%the wastage of power consumed.