NESL Technical Report #: 2008-7-5
Abstract: Recent new hardware and technology enable low-power inexpensive distributed sensor networks. To realize certain applications such as real time event detection, target tracking and system monitoring, time synchronization is essential. In the literature, a book of time synchronization techniques have been proposed. In general, the goal of a time synchronization mechanism is to devise a scheme that improves accuracy with lower energy consumption. Yet, there is clearly a trade off between accuracy and energy consumption. It would not be always desirable to deploy the most accurate time synchronization as it might drain the power. The choice of a time synchronization mechanism will depend on application's demand on timing accuracy as well as the energy budget. To estimate application's demand and select a proper time synchronization mechanism, the relationship between application's performance or QoI (Quality of Information) and time synchronization services are yet to be investigated. The paper formalizes the relationship between the performance of applications and time synchronization services based on analytic frameworks using representative applications, namely, event detection and estimation. The analysis shows the impact of timing errors for different event duration, target moving speed, number of sensors, sampling frequencies, etc. The analysis framework can also be used to extract the maximum synchronization errors that each application can sustain to achieve the desired QoI. Moreover, time synchronization plays a key role in energy-saving requirements. For example, accurate time synchronization can improve the efficiency of duty-cycling and thus save energy. In this paper, we will investigate the savings in power and bandwidth by employing different stabilities of clock sources.
Publication Forum: The Second Annual Conference of the International Technology Alliance (ACITA 2008) [Accepted]
Place: London, UK
NESL Document?: Yes
Document category: Conference Paper