An energy-efficient QoS routing for wireless sensor networks using self-stabilizing algorithm

Transmission delays caused by wireless multi-hop communications usually hamper the time-sensitive applications on wireless sensor networks (WSNs). In this paper, transmission delay of data packets is quantified as the number of hops from a sensor to base station (BS), and a tolerable delay (TD) of each packet denotes the initial value of aging tag (AT) to present their QoS metric. On the basis of predictability of TDMA schedule, we propose a self-stabilizing hop-constrained energy-efficient (SHE) protocol for constructing minimum energy networks for hard real-time routing. The protocol first constructs ad hoc multi-hop paths within a cluster while controlling the number of nodes in the cluster so as to meet the TD of data packets from member nodes to their CH. An adaptive routing protocol is then proposed to convey aggregate data packets from CHs to BSs in different routes depending on their current AT values, thus meeting their QoS requirements while prolonging the network lifetime.