Wireless Environment Based On The Best Listening Range Of The Size Of The Network

The signals transmitted over the wireless links may interfere with other communication pairs at the same time. This so-called Interference used to be regarded as a part of noise. Due to the further developing of the distributed networks, more and more nodes and traffics are needed in one network, especially in Ubiquitous Networks and Internet Of Things. One of the consequences of that is making mutual interferences increase significantly, and then seriously undermining the network performances. Hence, the interference problem becomes one of the major challenges in the wireless field.Adjusting carrier sensing range is a very efficient way to reduce the influence of interferences. However, to determine an appropriate carrier sensing range in different scenarios is still a big challenge. This thesis discusses the relationship between the carrier-sensing range and the network scale in distributed networks, and proposes an appropriate carrier sensing range related to network scale. Since the nodes covered by carrier sensing range will not be the interference nodes due to the access protocol, the interferences can be under control by increase the carrier sensing range. In the other hand, those nodes can not access the channel either. Hence the throughput can be raised by shrink the carrier sensing range. It means carrier sensing range becomes to the best choice to balance the error rate and the throughput. That is why it will be breakthrough to suppress the interferences by optimal carrier sensing range under reasonable throughput.The thesis will propose the interference model and strategy by multiple layers controlling, which is based on the nodes distribution according to the network construction. The new model will analyze the parameters under different layers, especially the access layer, and analyze the influence of the cumulated interference in physic layer, then yield the bit error rate and throughput. According to those performances, the effective packet throughput will be calculated, and it will be the accordance to provide the optimal carrier sensing range.The thesis proposes the interference control strategy based on the carrier sensing range. The advantage of that is that it can input the traffic scale through application layer, and input the node scale through network construction. So this model fairly considers the large scale network which has been widely used in the novel communication.The cumulative interference model which is constructed in this thesis is more realistic, it considers the cumulative interference and the cross layer parameters. The model considers the wireless channel and topology of the network which will be found in a practical scenario, and gain the network performances and the optimal carrier sensing range which can be used in the real cases.