Authors: Qin Liu; Yanan Chang; Xiaohua Jia
Addresses: School of Computer, Wuhan University, Wuhan 430072, China ' Computer School, Central China Normal University, Wuhan 430079, China ' Department of Computer Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
Abstract: We study real-time data aggregation problem for wireless sensor networks that use CSMA/CA MAC layer protocols. The problem is, for a given sink, a set of sensor nodes and a delay bound, to maximise the average transmission success probability of all sensor nodes within the delay bound. In CSMA/CA protocols, the success probability and the expected transmission delay are highly sensitive to node interference. We divide the system time into time-frames with fixed size and schedule the transmission of nodes into time-frames. The transmissions of all child nodes under the same parent are scheduled in the same time-frame. Therefore, the construction of data aggregation trees becomes very important in maximising the success probability of data collection. We solve the joint routing and scheduling problem by first constructing an aggregation tree that minimises the node interference. Then, we propose an efficient greedy scheduling method to assign time-frames to sensor nodes.
Keywords: data aggregation trees; real-time data aggregation; wireless sensor networks; WSNs; cyber-physical systems; CPS; success probability; contention-based protocols; MAC; medium access control; data collection; routing; greedy scheduling.
International Journal of Sensor Networks, 2015 Vol.18 No.3/4, pp.217 - 226
Received: 21 Sep 2012
Accepted: 18 Sep 2013
Published online: 05 Jul 2015 *