Research On Mobility Load Balancing Algorithms In LTE System

In the LTE (Long Term Evolution, LTE project) system,the number and structure ofnetwork parameters is large and complex. Taking into account the great cost of networkconstruction and network management,3GPP(3rd Generation PartnershipProject,3rdGeneration Partnership) introduced SON(Self-Organizing Networks, self-organizing network)to LTE,and Proposed a method that a self-organizing network is an effective and importantway to compress operating costs to reduce network complexity. Because the terminal servicesinto the area with the randomness and time-varying characteristics, this leading to unevendistribution of cell service,so wireless communication system has hot spots and non hotspots.The UE is unable to get satisfactory service because of Hot spots of the big traffic.NewUE enters a overloading cell，which can lead to a blocking cell and poor user experience.Business of neighborhood cell is not high, resource utilization is low,resulting in low resourceutilization of the whole network. MLB(Mobility Load Balancing, mobile load balancing) is aself-organizing network, one of the key technologies that can effectively improve theutilization of network resources, to solve the load imbalance between LTE cell.MLBalgorithm is becoming a focus we pay attention to.Based on the load balancing mature3GPP mathematical framework,as well as the studyof traditional load balancing algorithm,we analysis problems as follows:（1）Traditional load balancing algorithms,can be divided into two main strategies:a wayto minimize the load is transferred the load to the neighborhood cell, the other is toredistribute the load more evenly in neighboring cells,strategies relatively too extreme.（2）The threshold of the ending of the load balancing in traditional load balancingalgorithms are usually, triggering threshold of load balancing, that can easily lead to frequentshort trigger, then target cell’s extra resources can not get effective use.（3）Traditional load balancing algorithms for the too overload overloaded cellssurrounding overloaded residential area, usually do not accept the new load in, the systemresource utilization is slightly less.For the above three issues, this paper proposes a new and improved mobile loadbalancing algorithm, which is based on double cells selection and sharing the load balancing algorithms, taking into account issues about load transfer and load distribution, but also forthe overloaded cell circumstances surrounding area overloaded, The paper puts forward theown solutions, as much good use of network resources systems; proposing the concept ofjump threshold and average load transfer makes more reasonable time to end load balancing,transfer load more evenly.Through vienna LTE simulator system level,simulators are made interms of number of unsatisfied users,total handover times,load balance index and userblocking rate four aspects,verify the algorithm can improves the convergence speed and theneighboring cell resource utilization, this to improve the whole system resource utilization,increase customer satisfaction has played a good effect.