Research And Applications Of LTE-M's Key Technologies

LTE-M is that M2M (Machine-to-Machine) service conducts data transmission in LTE network. Compared with H2H (Human-to-Human)communication, M2M communication has typical characteristics such as various kinds of services, huge number of terminals, small data transmission, uplink dominant, low mobility of terminals and so on. Due to rapid development of MTC (Machine Type Communications), the number of MTC terminals is increasing massively, which causes enormous challenge for LTE network referred to characteristics of H2H service.When massive MTC terminals access to LTE network, instantaneous burst characteristics of MTC terminals will result in serious traffic overload and network congestion of LTE network. In the case of mixed service(M2M service and H2H service) accessing to LTE network simultaneously,it is necessary to build traffic model for evaluating the system performance of LTE network and proposing the overload control mechanism. The model needs to reflect the instantaneous burst characteristics of M2M service and simultaneous transmission of mixed service, which will provide solution for optimization of LTE-M network.In this paper, we research the impact of LTE network with different frequency on transmission of M2M service initially. Meantime, Qos mapping between M2M service (power distribution service) and traditional H2H service is proposed for smart grid scenario, and service priority is also proposed. Furthermore, one network selection scheme is raised for LTE-M network to alleviate the traffic load of public LTE network and improve reliability and security of service transmission.What's more, based on 3 GPP reference model and measured data of references, service statistics model is proposed for coexistence scenario of H2H and M2M service, which can provide solutions for overload control mechanism.Finally, overload control mechanism of mixed service is proposed for LTE-M network based on traditional ACB (Access class barring)mechanism. Due to delay insensitivity of M2M service, system performance can be optimized by adjusting the backoff time of M2M service dynamically. By simulation, the proposed mechanism can significantly improve network successful access rate of mixed service and upgrade system performance.