Immune Computing-based Resources Optimization In Wireless Communication Network

With the rapid development of3G communications systems and wireless accesstechnology, more and more people can enjoy the convenience brought by the wirelesscommunication. Mobile communications systems are resource-constrained systems.With the needs of the wireless business in the sustained rapid growth, the wirelessresources, such as base station location resources, spectrum resources, code resources,power resources, bandwidth resources and so on, are becoming more and moreshortages. Thus how to effectively utilize the limited wireless resources to meet growingbusiness needs have become the issues of common concern for researchers and mobilenetwork operators. Radio resource management (RRM) is an important research hot ofthe wireless communication network. It can provide the maximum coverage, systemcapacity and system performance, by optimizing the allocation of the resources of thewireless communication network, so as to support many users to access the limitedradio resources. The optimization model and optimization algorithm for resourcesallocation of wireless communication network are researched. The author’s majorcontributions are outlined as follows:1. The base station location has an important influence on the quality of service forwireless communications networks.It should take full account of the coverage area ofbase station, construction cost, maintenance convenience, and other factors, when weplan base stations location. Base station location optimization is an important element ofthe wireless communication network optimization,it’s task is to optimize the numberand location of base stations with considering signal quality, construction costs, andcoverage constraints, and other network parameters, it’s target is to obtain a highercoverage network with a lower base station construction cost. The problem of basestation location planning in wireless network has been studied. Firsty, the locationoptimization model for TD-SCDMA network base station was expound, three cloningoperators with real-number encoding were designed, a solution of base station locationplanning based on immune computing was proposed. Secondly, the problem of basestation location planning in the WCDMA network has been studied. There is obviousrespiratory effect in the WCDMA network, capacity and coverage of mutual influence,which makes the problem of base station location planning becoming very complicated.The link budget is used to determine the maximum acceptable path loss of WCDMAnetwork, in order to estimate the radius of a cell and the coverage area of a base station.The load factor is used to estimate the total number of users supported by each base station. The solution of optimization locations based on immune algorithm is proposed.Finally, the location planning problem of base station and relay station in IEEE802.16jnetwork has been studied. When IEEE802.16j relay system works in a transparentrepeater mode, mobile terminals must be in the coverage of the base station in order toensure that the relay propagation. The mathematical model of location planning of basestation and relay station is expounded, a solution of location planning based on immunecomputing is proposed. Experimental results show that the proposed solution ofoptimization locations can meet the coverage needs with low cost of networkconstruction relatively, and has the advantages of good theoretical value.2. The pilot channel shares downlink power with the other for downlink channel.Since the maximum transmit power of base stations is rated, pilot power accounts for alarge proportion, the proportion of other downstream channel power will be reduced.Too large pilot power will increase the downlink interference, cell overlapping area,also lead to a larger area of the pilot pollution. On the other hand, if the pilot power istoo small, then it will lead to decreased cell coverage area, which will lead tooverloading of the adjacent cell or network coverage holes. Therefore, it is verynecessary to optimize the base station pilot power according to the demand of basestation coverage and business support capabilities. The femtocell can effectivelyimprove the network capacity of local area, and solve the problem of coverage blindspots, so the femtocell pilot power allocation problem in next-generation cellularnetwork has been studied in this paper. Based on the network topology structure andcommunication flow distribution, an allocation solution for the pilot power of femtocelland the radius of femto cell are given. Experimental result shows that the proposedsolution can effectively allocate pilot power, and has the advantages of good theoreticalvalue.3. The seamless integration of various heterogeneous access networks is one of thesalient features of the next-generation network. The joint session admission control ismacro perspective resource management for heterogeneous wireless communicationsystem, its purpose is to the user session in various wireless access network balanceddistribution. The joint call admission control problem in heterogeneous networkenvironment of single operator has been studied. The mathematical model of joint calladmission control problem is expounded, a novel joint call admission control solutionbased on immune computing is proposed, and simulation experiments are done tovalidate the proposed solution. Experimental result shows that the proposed solution, compared with other solutions, obtains better performance tradeoffs between recentutility and frequency spectrum, balances preferably each radio access network of thesame operator.4. Vertical handoff in heterogeneous network convergence scenario is an effectivemeans to ensure wireless business continuity, and also an effective way to adjust thevarious wireless access network load distribution. The vertical handoff decisionalgorithm determines the performance of vertical handoff. The vertical handoff decisionproblem in heterogeneous network convergence scenario has been studied. In this paper,a mathematical model for vertical handoff decision problem is expounded, an artificialsimple harmonic oscillator immune algorithm-based vertical handoff decision scheme isproposed, and simulation experiments are done to validate proposed solution.Experimental result shows that the proposed solution, compared with literature solutions,can not only balance the overall load among all networks but also increase the collectivebattery lifetime of mobile terminals, and has the advantage of good reference value.5. In heterogeneous network environment integrated multiple radio accesstechnology, the non-uniform distribution of users’ calls in the time domain and in theairspace is the important factor affecting the performance of heterogeneous wirelessnetwork. The load balance problem in heterogeneous network convergence scenario hasbeen studied, and a novel dynamic load balance scheme based on access selection andcalls transfer is proposed. In this paper, access selection is modeled as a constrainedoptimization problem, and the access calls is assigned to all base station evenly inaccordance with the optimization result. In addition, in order to weaken thedestructiveness of sudden calls from hot area to the system load balance, a calls transferstrategy based on the threshold of base station load rate is given. Experimental resultshows that the proposed solution performs better than literature solutions in accessblocking rate, calls dropping rate, load balance and system utilization rate.