  Time synchronization for wireless sensor networks (WSNs) has been studied in
recent years as a fundamental and significant research issue. Many applications
based on these WSNs assume local clocks at each sensor node that need to be
synchronized to a common notion of time. Time synchronization in a WSN is
critical for accurate time stamping of events and fine-tuned coordination among
the sensor nodes to reduce power consumption. This paper proposes a
bidirectional, reference based, tree structured time synchronization service
for WSNs along with network evaluation phase. This offers a push mechanism for
(i) accurate and (ii) low overhead for global time synchronization. Analysis
study of proposed approach shows that it is lightweight as the number of
required broadcasting messages is constant in one broadcasting domain.
