To hop or not to hop in massive machine-to-machine communications

Recently, machine-to-machine (M2M) communication becomes an attractive topic due to the rapid evolution of wireless communication systems and the potential market size of Internet of Things. In this paper, we investigate a M2M network with typical M2M features. Three key parameters, throughput capacity, delay and energy consumption, are analyzed to evaluate the performance of the M2M network under multi-hop and single-hop manner. By scrutinizing these parameters, we find that as r grows from √logn over πn to 1, delay increases progressively from order √nlogn to order n. Meanwhile, throughput keeps the same at order W/n. And there exists an optimal transmission range to minimize average energy consumption. Our results state that multi-hop manner is effective to decrease the delay and energy consumption of M2M network, without benefit on the throughput. To answer the question “to hop or not to hop in massive machine-to-machine communications”, we provide guidelines based on different optimal transmission ranges for the M2M network with different M2M features respectively.