Home // SENSORCOMM 2011, The Fifth International Conference on Sensor Technologies and Applications // View article
Authors:
Ville Kaseva
Timo D. Hämäläinen
Marko Hännikäinen
Keywords: Wireless Sensor Networks, Time synchronization
Abstract:
Ultra low-power Wireless Sensor Networks (WSNs) use duty cycled medium access protocols and dynamic routing for multi-hop communication. Transmitted packets can have variable delays and routes. Thus, data timestamps and temporal order of the packets are unknown. However, timing information is essential for many WSN applications. In this paper, we present a novel time synchronization protocol for application packets in multi-hop WSNs. The proposed protocol is based on calculating delays as packets traverse from node to node. It provides high energy-efficiency by minimizing communication overhead. Fault tolerance is achieved by fully distributed operation. The protocol computational complexity is low, including only simple operations. We experimented the proposed protocol using real WSN hardware communicating in 2.4 GHz radio band. The maximum synchronization errors ranged from 72 us to 909 us, and the average errors from 20 us to 153 us when the hop count was varied from two to six and varying protocol parameters were used. With values extrapolated from the experimental results, the maximum error was 15 ms, which occurred with 100 hops. The paper presents the design, implementation, and experimental results for low complexity synchronization protocol with maximum errors ranging from 72 us to 15 ms with varying network sizes.
Pages: 79 to 84
Copyright: Copyright (c) IARIA, 2011
Publication date: August 21, 2011
Published in: conference
ISSN: 2308-4405
ISBN: 978-1-61208-144-1
Location: Nice/Saint Laurent du Var, France
Dates: from August 21, 2011 to August 27, 2011