Design And Implementation Of VoLTE Service Traffic Charging Method

VoLTE (Voice over LTE) is a basic communication service provided by 4G network. There is a fundamental difference between VoLTE and 2G/3G voice, where 2G/3G voice is provided by circuit domain, while VoLTE is provided by packet domain. For VoLTE service, session control and service logic are provided by IP Multimedia Subsystem and the bear is provided by EPC network. The new network architecture and service characteristics of VoLTE posed a new problem for billing: voice charging by traffic. For VoLTE voice call, the traffic information is recorded by bearer layer charing CDR, and the charging mode is offline-charging. For the call hold service, call waiting service and multiparty call service, when there has two or more calls simultaneous on the same user (eg. user hold the ongoing call and receives a new one),it can’t distinguish every call’s data traffic, because these calls use the same bearer.This paper proposes a VoLTE call hold service traffic charging method to solve the problem that P-GW can’t distinguish multiple calls’data traffic in call hold service, call waiting service and multiparty call service scenarios. The VoLTE call hold service traffic charging method modifies the RG decision procedure on PCRF and makes PCRF configures a new RG and rating group level reporting in pcc rule, thus it affect the charging process on P-GW and make it can distinguish multiple calls’ data traffic in PGW-CDR. Based on the OpenIMSCore and UCT PCF, this paper realized the main function modules of the VoLTE call hold service traffic charging method by adding decision procedure of ARP, RG, SID and charging control information on UCT PCRF and adding offline charging function on UCT PCEF. Finally, this paper test and validate the functions of VoLTE call hold service traffic charging method. The result shows that this method can make it distinguish multiple calls’ data traffic.