Multi-traffic-based Load Balance Mechanism For LTE Ultra Dense Networks

With the complexity of intelligent terminal traffic and the diversification of user movement,the traditional LTE network has been not meet the requirement of user communication depending on high bandwidth and high reliability.This demand promotes the development of small cell in the LTE network.In order to improve the network capacity and ease the load pressure of the macro cell,the operator begin to deploy the small cell into LTE networks.It enhances the network performance.But a growing number of small cell deployment makes the increasing small cell density,the LTE network become an ultra dense network.The problem make the network optimization technology has new challenges.In the ultra dense network,the small cell density increasing make the distance of cells shortened.Meanwhile,the interference between the base station and user get worse.Due to the number of small cell and user traffic diversity,making cell selection algorithm become more complex in the LTE network.And the uneven user distribution in the network make the cell load overload,so an effective load balance algorithm for improving the network performance is a very important factor in network optimization algorithm.Therefore,depending on the traffic feature and network characteristics,this paper present a threshold-based multi-traffic load balance algorithm for network optimization.To improve the accuracy of cell selection in load balance algorithm by the user traffic analysis.Besides,the threshold adjustment strategy and TTT adjustment strategy ensure the success of handover.Then,given that small cells are denser deployment,not all of them have a direct connection to the core network,thus a multiple hops path from terminal nodes to core network should be established via the relay by other small cells.So some small cells will forward the data to the adjacent small cells until the data reach the core network.To meet the requirement of the tolerance latency of UEs,the transmission delay should be taken into account in the cell selection process which affected by plenty of factors in the scenario of various traffic.Furthermore,the term ”matching degree”is introduced to find out the optimum cell for UEs as measured by the latency and resource allocation.In this paper,we investigate the feasibility of wireless network topology for the ultra-dense network.Then a new cell selection algorithm based on the latency and signal strength is presented for multi-hops networks.Besides,a load balance problem aiming at minimizing the call drop rate and maximizing the resource utilization will be proposed for uneven traffic scenario.This problem is a NP-hard optimization problem.So we propose a heuristic algorithm based on the adaptive threshold adjustment.It make the network load balancing and have low complexity of the algorithm.Finally,this paper set up a system-level simulation platform for LTE heterogeneous networks and ultra-dense network,to verify the performance of the algorithm,the simulation results indicate the threshold-based multi-traffic load balance algorithm and bias optimization algorithm can ensure that users quality of service,reduce the user's call dropped,improve the overall network throughput and make network load balancing.