Signalling Load Sharing In Radio Network Controllers Of TD-SCDMA Networks

With the rapid development of China Mobile's TD-SCDMA network,the number of users is increasing,and the user usage model has gradually changed from large data flow to small data flow with more service requests.This has led to substantial growth of mobile signalling overhead and consequently the load on radio network controller's signalling plane is becoming higher and higher.Since the number of base stations or traffic connected to the radio network controller's signalling processing units is not balanced,in the case of traffic burst,this will lead to overload in some individual signalling processing subsystem and will cause instability to the radio network controller's performance.Therefore,the study on load sharing mechanism for the radio network controller's signalling plane is an indispensable work for development and expansion of China Mobile's TD-SCDMA network.Based on the current operations and future requirements of China Mobile's TD-SCDMA network,this thesis analyzes the working process of signalling plane in radio network controllers,studies the feasibility of load sharing function in the signalling plane,and proposes a load sharing program which includes a load sharing process and parameter settings for radio network controllers.To verify the effect of the load sharing program,we have conducted tests in current network with different flow control thresholds and load balancing thresholds.By comparing with traditional load balancing methods,some key points of the signalling load sharing program are concluded.Signalling load sharing in radio network controllers of TD-SCDMA networks breaks the traditional one to one mapping between TD base station/cell and signalling processing unit.It is different from traditional solutions to ease the signalling congestion problem.Based on the system structure and unit operating characteristics,it makes use of signalling processing subsystem load sharing algorithm and reasonable parameter threshold setting to achieve internal signalling load sharing and solves the problem of sudden increase in signalling load more efficiently and effectively.It also helps to promote the upgrading of the TD-SCDMA network's overall system capability and control network maintenance costs and post-investment.