Bulk credit reservation in event-based Machine Type Communications for 3GPP online charging

Machine Type Communications (MTCs) open up new applications and new markets for mobile operators. One of the major open problems in the field of MTC is to handle a very large amount of traffic with small payloads along with the requirements for creating bulk Charging Data Records (CDRs). This paper proposes a new credit reservation procedure, called Multiple Event-based Credit Reservation (MECR), to effectively manage online credit for event-based MTC services in 3GPP core networks. We develop an analytical model and conduct extensive simulation to investigate the performance of MECR. Specifically, output metrics include the number of MTC reports served and the unused credit returned when the MECR procedure is executed. Numerical results show that the proposed MECR procedure can significantly reduce the signaling overhead of online charging in terms of the number of credit control messages and the number of CDRs generated.