Call Admission Control And Load Balancing In Ultra Dense Network

The next generation of mobile communication system faces higher data transmission rate challenge and higher capacity challenge,and ultra-dense networking meets the data capacity requirement by increasing the deployment density of base stations.With the dense and irregular deployment of base stations,it will have a great impact on the system,especially the wireless resource management technology.Therefore,this paper aims to study two important parts of wireless resource management in ultra-dense network-call admission control and load balancing technology.First,this paper studies call admission control strategy based on channel reservation.First,a certain number of protection channels are reserved for handoff calls so that the priority access of handoff calls is guaranteed.Considering the flexibility of BE traffic for QoS requirements,when a BE call is allowed to borrow a channel reserved for a high priority call,if a handover call arrives,the call is switched to preempt the service of the BE service and the preempted BE call is queued waiting to resume its service whenever the channel is available.Second,this paper has different needs for real time business and non-real time business.Considering the utility function of different performance indicators,and achieve fuzzy decision of utility function through fuzzy logic system,adjusting load of each cell according to the fuzzy decision value to achieve multi-objective optimization and load balancing purpose.In addition,considering load balancing problem in cooperative multi-point transmission scenario in ultra-dense network,a joint CoMP clustering and load balancing optimization strategy is proposed.Firstly,user-centered adaptive clustering is adopted to optimize the user spectral efficiency,then re-clustering users under overloaded cells for load balancing purposes.In the end,this paper simulates,analyzes and compares the proposed call admission control strategy and load balancing algorithm respectively.The new call admission control algorithm has little impact on handoff call drop rate in the dense cell-deployment scenario,reduces the call blocking rate and effectively increases the system resource utilization rate.The load balancing algorithm based on fuzzy logic can achieve the real-time Multi-objective optimization of service average transmission time,real-time service blocking rate and load balancing as well as CoMP clustering and load balancing joint optimization algorithm can effectively relieve the load of high-load cells,achieve load balancing while having a lower impact on user spectrum efficiency.