Introduction
Ad hoc networks have become more and more popular and many research problems, such as routing, quality of service and security, are now addressed. Most of the current ad hoc networks are based on the IEEE 802.11 standard owing to the fact that this is the most widespread technology in the field of wireless local networks and it provides a distributed medium access with the DCF mode.Recently, different studies have shown some performance issues with the DCF mode, used in ad hoc network. These studies show that the origin of the performance problems comes from the MAC layer of this mode. These performance problems often lead to unfair situations and global performance loss .Several solutions have been proposed to improve 802.11 performance in wireless ad hoc networks by reducing unfairness issues or by improving global throughput. Recently, several approaches try to increase both throughput and fairness by modifying the 802.11 MAC layer. Most of these solutions are based on rate and topology information exchanged between the nodes. The proposed protocols, not based on this kind of information, either reduce the fairness issues to the detriment of the aggregate throughput or increase the overall throughput without solving the fairness issues. In the investigate the trade-off between aggregate throughput and fairness. They propose a model to compute the maximum aggregate throughput under various fairness schemes, but their algorithm is based on information propagation. Therefore, it is still a real challenge to design a fair MAC protocol for ad hoc networks that is distributed, topology independent, that relies on no explicit information exchanges and that is efficient, i.e. that achieves a good aggregate throughput.
In this project, a solution to this challenge by designing a new protocol, called MadMac,that increases fairness in 802.11-based ad hoc network while maintaining a good aggregate throughput in the network. One of the main advantages of MadMac is that it is easy to implement because it is only based on information provided by the 802.11 MAC layer.
Ad hoc networks have become more and more popular and many research problems, such as routing, quality of service and security, are now addressed. Most of the current ad hoc networks are based on the IEEE 802.11 standard owing to the fact that this is the most widespread technology in the field of wireless local networks and it provides a distributed medium access with the DCF mode.Recently, different studies have shown some performance issues with the DCF mode, used in ad hoc network. These studies show that the origin of the performance problems comes from the MAC layer of this mode. These performance problems often lead to unfair situations and global performance loss .Several solutions have been proposed to improve 802.11 performance in wireless ad hoc networks by reducing unfairness issues or by improving global throughput. Recently, several approaches try to increase both throughput and fairness by modifying the 802.11 MAC layer. Most of these solutions are based on rate and topology information exchanged between the nodes. The proposed protocols, not based on this kind of information, either reduce the fairness issues to the detriment of the aggregate throughput or increase the overall throughput without solving the fairness issues. In the investigate the trade-off between aggregate throughput and fairness. They propose a model to compute the maximum aggregate throughput under various fairness schemes, but their algorithm is based on information propagation. Therefore, it is still a real challenge to design a fair MAC protocol for ad hoc networks that is distributed, topology independent, that relies on no explicit information exchanges and that is efficient, i.e. that achieves a good aggregate throughput.
In this project, a solution to this challenge by designing a new protocol, called MadMac,that increases fairness in 802.11-based ad hoc network while maintaining a good aggregate throughput in the network. One of the main advantages of MadMac is that it is easy to implement because it is only based on information provided by the 802.11 MAC layer.
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