Cross-layer cooperative multichannel medium access for internet of things

Wireless networking in the Internet of Things is a challenging problem because a huge amount of devices in a relatively small region need to be interconnected. Particularly, the carrier sensing multiple access with collision avoidance (CSMA/CA) operation of IoT devices is not viable solution, since dense network leads to high channel contentions. Moreover, given an intensive network traffic load, long queues or even queue overflows are expected, which further deteriorates network performance. To address these issue, multichannel medium access is proposed and it attracts great attention recently. In this paper, we firstly establish models based on combinatorics theory to analyze the performance of dynamic multichannel medium access. Then, a Cross-layer Cooperative Multichannel Medium Access (CCMMA) is proposed to effectively avoid channel contentions by enabling neighboring devices to communicate on orthogonal channels. The CCMMA also introduces a routing-enhanced mechanism that enables relaying nodes to wake up intelligently if there is incoming traffic, that successfully mitigates delay and queue overflow problems caused by low-power operation of IoT devices. The performance of CCMMA is evaluated through extensive simulations. The results show that it provides significant improvement in terms of quality of service over existing solutions.