Event Ordering by Double Confirmation in Wireless Sensor and Actor Networks

Wireless sensor and actor network (WSAN) is a new kind of heterogeneous wireless sensor networks. In WSANs, while sensors gather and send the sensing messages from the physical environment, actors need to take appropriate actions. Based upon the rich source actor, WSANs are increasingly deployed for accurately monitoring the environments subjected to critical conditions. The ordering of monitored events actor received could determine the correct interpretation of what event is occurring in the monitored environment. Hence, event ordering in WSAN is an important issue for applications in monitoring. To address this issue, we proposed an event ordering by double confirmation (OBDC) that could guarantee the event ordering to be correct completely. The simulation results demonstrated that the rate of correct event ordering of OBDC could be up to 100%, but its event handling time and energy consumption increased only more 3.2% and 4.4%, respectively, than the existing algorithm, OBC. However, OBDC still assures the rate of correct event ordering to be 100%, as the quantity of sensed events increased.