Massive Access Control in Machine-to-Machine Communications

Introduction

Machine-to-machine (M2M) communication is a new communication model, where a large number of “intelligent-devices” communicate with each other with the help of wired/wireless networks, and can make collaborative decisions without direct human intervention (Verma et al, 2016, Chen et al, 2012; Igarashi et al, 2012). Machine-to-Machine (M2M) communication has its origin in the supervisory control and data acquisition(SCADA) systems, where sensors and other devices being connected through wired or radio frequency networks are used with computers to monitor and control industrial processes. A key factor behind the growth of M2M communications today is the pervasive accessibility of low cost, ubiquitous connectivity. We have already become used to low cost, high-speed home and commercial internet access. Now-a-days, in many regions around the globe, 3G and LTE mobile networks provide almost similar access speeds at highly competitive prices. The logic behind M2M communications is based on two observations. First, a networked device becomes more valuable than an isolated one. Second, when a large number of machines are networked/interconnected together, they produce entirely new autonomous and intelligent applications. For these reasons, M2M communication has quickly become a new area for research in academics and a market changing force for a wide variety of real-time monitoring applications in industry such as smart grids, home area networks, e-healthcare, intelligent transportation systems, environmental monitoring, and manufacturing applications. The system model of M2M communications is shown in Figure 1, which consists of three interlinked domains. These are M2M device domain, network domain, and application domain (Rongxing et al, 2011). In M2M domain, an M2M area network is formed by the collaboration of a large number of M2M devices (e.g. sensors, actuators, smart meters etc.) and M2M gateways. These M2M devices collect the sensory data by sensing techniques from different part in the M2M domain and collaboratively make intelligent decisions to transmit the sensory and monitored data to an M2M gateway. The M2M gateway itself is an “intelligent device”, which receives the sensory data and efficiently manages the received data packets. It forwards the data packets through efficient paths by single-hop or multi-hop channels via a network domain to the back-end server of the application domain. If the M2M domain contains multiple gateways, they can further communicate with each other to make collaborative decisions (P2P model). Furthermore, the network domain acts as an interface between M2M domain and application domain. In network domain, long-range wired/wireless network protocols (e.g. Wi-MAX, 3G/4G cellular networks) are used to provide cost-efficient and reliable channels with wide coverage to transmit the sensory data from M2M domain to the application domain. Lastly, the application domain consists of a back-end server and M2M application clients. The back-end server is the main component of M2M communications model and acts as an integration point to store all the sensory data transmitted from the device domain. It also provides the real-time monitoring data to various client applications for real-time Remote Monitoring Management (RMM), i.e. smart metering, e-health care, and traffic monitoring. The back-end server can also vary for different applications; e.g., in smart grids, the control center acts as the back-end server, whereas in e-healthcare systems, the back-end server is the M2M health-monitoring server.

Figure 1.

M2M communications system model