• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.1-11
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• 2018

This paper explores the reliability issue especially associated with the time-division synchronous communication when a networking stack is implemented using software timers provided by embedded operating systems. Especially, we explore the reliability of beacon synchronization of IEEE 802.15.4. Our experiments based on its practical implementation clearly show that processing delays or losses of hardware timer interrupts used for software timers lead to occasional failures in beacon synchronization. To avoid such failures, we suggest a reception time compensation scheme that turns on the receiver earlier than expected.

• The Journal of Society for e-Business Studies
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• v.15 no.4
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• pp.49-58
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• 2010

The wireless sensor network technology becomes one of core technologies to make it possible to implement various e-business applications. Energy efficiency is an important issue in wireless sensor networks. IEEE 802.15.4, a representative international standard for wireless sensor networks, provides the beacon enabled mode for energy-efficient communication. However, the beacons may conflict each other when the network is of multi-hop topology such as mesh or cluster-tree topology with beacon-enabled mode. The beacon conflict causes the failure of synchronization between sensor nodes, and affects other nodes in the network in that unsynchronized nodes cannot participate in communication. In this paper, we suggest an energy-efficient beacon scheduling for the wireless sensor networks. Nodes can save their energy duringperiod and prevent beacon conflict using beacon scheduling. We implement the scheduling using QualNet, and evaluate the performance under mesh topology networks. It turns out that the proposed scheduling may improve the energy efficiency in the networks.