机器与机器之间的通信在现有蜂窝网架构中应用广泛。然而由于机器与机器通信终端数量巨大，当大量的终端同时发起随机接入请求时必然引发冲突碰撞、网络拥塞和延迟过度等问题。为了解决这些问题，提出一种基于终端分组的方法，根据能量消耗的快慢对机器终端进行分组，并对组设定优先级，能量消耗越快，其优先级越高，优先级高的组终端优先分配随机接入资源。仿真结果表明，该方法能够有效地降低碰撞概率，节省能量；同时还能提高终端成功接入率，降低延迟。

Machine to Machine (M2M) communications are widely used in the existing cellular network architecture. However, due to the huge number of M2M communication terminals, conflicts, network congestion, delay and other issues may occur when a large number of M2M terminals simultaneously initiate random access requests. In order to solve these problems, this paper proposes a group-based random access mechanism which groups the terminals and sets the priority. And the high priority group terminals can be allocated random access resources preferentially. The simulation results demonstrate that the proposed method can effectively reduce the collision probability, save energy, improve the probability of successful access of the terminal and reduce the time delay.