Performance Analysis of a Novel Low-Complexity High-Precision Timing Synchronization Method for Wireless Sensor Networks

Abstract

In wireless sensor networks, nodes periodically wake up and sleep in order to reduce their energy consumption. One challenge in this scenario is how to coordinate the sender and receiver so that they can wake up and sleep at the same pace to maintain connectivity. In this paper, we present a synchronization method that has very low energy consumption overhead yet highprecision synchronization performance. Different from existing synchronization methods, it does not need to correct the offsets and skews of the clocks of nodes. Instead, our proposed method takes advantage of the fact that the time interval between two transmitted beacons is the same as the time interval between two received beacons, since the propagation and coding delay can be assumed to be similar in these two transmissions. Thus, the receiver and the sender can be synchronized using their individual clocks. Based on this key idea, our synchronization method can overcome the offset and drift issue without modifying the clocks. This paper focuses on the theoretical analysis to evaluate this proposed method. The closed form expression of the error limits for our method has been obtained. Also the correctness of the theoretical analysis has been verified by our experimental results.

Synchronization of application-driven WSN

“…WSN are energy limited so typically the nodes cannot keep radios active all the time, having to sleep and to wake up periodically [21]. Addressing this issue, there have been proposed several MAC protocols which were categorized as synchronous or asynchronous MAC protocols.…”

“…These protocols transmit a SYNC packet to notify neighbors about their schedule and to synchronize the clocks of all nodes in the network. The method only compensates for clock offset and does not consider clock drift [21]. Moreover, the knowledgement of traffic patterns can also help to take decisions about waking up.…”

“…Usually, the senders broadcast a reference message and receivers, upon the reception of the message, record the arrival time by their own clocks, and exchange this information among each other to compensate clock offset between them. In [21], a synchronous method is proposed in which clocks in the all network are not modified. Instead, the nodes are synchronized with their own clocks.…”

“…The amplifying factor is the β parameter, and for it, we selected three values, β ∈ {10, 50, and 100}. Figures 19,20,21,22,23,24,25,26, and 27 show the results obtained for different combinations of the parameter's values. Table 1 …”

Energy-efficient node selection in application-driven WSN

“…WSN are energy-limited so usually the nodes cannot keep radios active during all the time, having to sleep and to wake up periodically [26]. Addressing this issue, there were proposed several MAC protocols which were categorized into synchronous MAC protocols and asynchronous MAC protocols.…”