The Research And Design Of QoS-Based Softswitch Billing System

Billing in Softswitch is one of the most important and challengeable issues in telecommunication services.It is known to all that traditional billing system only aims at single service billing,in which pre-paid and post-paid billings are separated from each other.However,under the background of "Three Networks Convergence" and multi-service application,such distributed and isolated billing system may cause low billing efficiency and repeated construction of system.On the other hand, in the current Softswitch networks application of huge capacity and large bandwidth,the linear billing strategy,which is based on time-length or flow-rate with fixed fee,can not meet the needs of users.Therefore,the creative points of the thesis is to design a billing policy on the basis of QoS(Quality of Service),which satisfies multi-service composed of voice,data and media and different demand of QoS.According to convergence of pre-paid and post-paid,the billing policy is divided into two parts,i.e.linear charging strategy and nonlinear QoS price regulating strategy.Meanwhile,a Softswitch billing server is designed and realized on the platform of Softswitch by employing so called next generation billing protocol Diameter.Firstly,on the basis of analyzing Softswitch QoS and billing theory, we combined billing parameters,which reflecting network quality in SLA, with billing information and establish a satisfying multi-service billing model.Based on this model,we propose a QoS billing policy,which including linear charging and nonlinear QoS dynamical feedback charging strategy.Moreover,a flexible and satisfying multi-service algorithm is presented.Secondly,this QoS billing strategy is deployed and applied in system of Softswitch media communiation.Based on SIP extent protocol in Diameter and OpenDiameter open-source protocol stack,a Diameter billing server is developed,which achieve the authentification and billing functions.Finally,some tests of Diameter authentication and billing are carried out on the Softswitch platform.It is shown that the testing results verify the feasibility and superiority of the Softswitch strategy based on QoS. The results provide very important theoretical foundation and practicality for Softswitch applications.