Low-latency Data Gathering with Reliability Guaranteeing in Heterogeneous Wireless Sensor Networks

In order to achieve low-latency and high-reliability data gathering in heterogeneous wireless sensor networks (HWSNs), the problem of multi-channel-based data gathering with minimum latency (MCDGML), which associates with construction of data gathering trees, channel allocation, power assignment of nodes and link scheduling, is formulated as an optimization problem in this paper. Then, the optimization problem is proved to be NP-hard. To make the problem tractable, firstly, a multi-channel-based low-latency (MCLL) algorithm that constructs data gathering trees is proposed by optimizing the topology of nodes. Secondly, a maximum links scheduling (MLS) algorithm is proposed to further reduce the latency of data gathering, which ensures that the signal to interference plus noise ratio (SINR) of all scheduled links is not less than a certain threshold to guarantee the reliability of links. In addition, considering the interruption problem of data gathering caused by dead nodes or failed links, a robust mechanism is proposed by selecting certain assistant nodes based on the defined one-hop weight. A number of simulation results show that our algorithms can achieve a lower data gathering latency than some comparable data gathering algorithms while guaranteeing the reliability of links, and a higher packet arrival rate at the sink node can be achieved when the proposed algorithms are performed with the robust mechanism.