Research Of The Power Control Based On The Region Physical Interference Model In The Wireless Mesh Networks

The rapid development of the wireless communication technology and mobileInternet has changed people’s lives enormously. With varieties of advantages, such asthe capability of self-organization, strong scalability and reliable service coverage,wireless Mesh networks can satisfy people’s requirements by offering seamlesswireless service of high quality. As a new technology to solve the bottleneck of the“last miles” to the Internet, wireless Mesh networks have drawn great attentionsimmediately when it just appeared, and been regarded as one of the most potentialwireless network technologies due to its advantages and favorable prospects.Because of the broadcast nature of the wireless signal and wireless resourcesharing between the nodes, interference emerges at any receiving node which sharesthe same channel with the destination node in the networks, which influences theperformance of the wireless network seriously, and the interference problem becomesparticularly severe in the wireless Mesh networks. The main process to deal with theinterference problem can be figured as2steps: establishment of the interferencemodel, and the design of the scheme to decrease the interference. The accuracy of theinterference model contributes greatly to the effectiveness and availability of thescheme. Meanwhile, power control is a practical and effective approach to reduce theinterference between the nodes. As a result, it has huge significance both establish aprecise interference model and design an effective power control scheme based onthat model as well.After a deep research into the current interference models, this paper analyze andthe2common models: binery interference model and cumulative interference model.Then a region physical interference model, which can describe the interferencebetween the links is established. This model not only takes the interference whichbinery interference model ignores into account, but also improves the cumulative onewhich judges the interference by a threshold. A study to discovery how the factors likethe number of active links, interference radius and sending power influence thethroughput is conducted by the way of simulation and formula derivation.In the wireless Mesh networks, power control could be really complicatedbecause of the Mesh characteristics. On one hand, a high sending power is theguarantee for the receiving node to receive the date correctly, on the other hand, thehigher the power is, the more interference other nodes would get, which would lead toa degrade to the total throughput of the whole internet. As a result, it is essential toadjust the power of all the nodes reasonably to achieve an ideal throughput. Based onthe region physical interference model, a power control scheme is designed by themeans of DE-HM (Differential Evolution-Harmony Search) algorithm. Simulationresults indicate that compared with the scheme that all the nodes transmit with the max power, DE-HM scheme can achieve a better throughput and reduce the itsdependence on the interference radius.Considering the multiple rates provided by the physical technology of thewireless Mesh networks, a different effects the receiving node may get when thesending node chooses a different rate. Adapting the rates according to the relationshipof the throughput and SINR, an advanced power and rate joint control scheme JointDE-HM scheme is designed. Simulation results show that the Joint DE-HM schemecan perform better than the scheme which adjusts the power only.