Centralized/Autonomous Hybrid Channel Selection for Wireless Vital Sensor Networks

In this paper, we focus on vital data collections using wireless sensor networks (WSNs), where sensor nodes are attached to a large number of exercisers. For increasing the number of supported nodes with WSNs, it is necessary to utilize multi-channel communications, which can suppress the number of operating nodes per channel. However, the reduction of operating nodes at each channel increases the number of isolated nodes that have no neighboring node within their communication ranges. Therefore, a protocol called autonomous channel selection based multi-hop access protocol (ACS-MAP) has been proposed, which reduces the number of isolated nodes by introducing autonomous channel selection and switch conducted by each isolated node. However, ACS-MAP suffers from the unbalanced number of data transmissions at different channels depending on the distribution of nodes at each channel. In this paper, in order to solve this problem, we introduce a centralized switch of the assigned channels of sensor nodes considering their locations inside the given network. With computer simulations, we show that the proposed centralized/autonomous hybrid channel selection achieves better data collection rate than the conventional ACS-MAP.