Abstract:
This paper is presented as hybrid protocol for
MAC layer in Wireless Sensor Networks (WSNs). It
combines contention and schedule-based methods.
Time slots are assigned at deployment and
reassigned when significant changes in topology.
Time slot assignment is designed by semidistributed
manner. A base station is considered as
a master only for its one-hop children because
nodes are also memory (buffer)-constrained ones
in real world. When a base station sends token to
its neighboring nodes all the way through the
largest-hop nodes and token is sent back to the
base station causing the overflow of buffer or the
time slot assignment table may be damaged during
token is passing through all the nodes. To avoid
this problem, time slot assignment is only
considered as the two-hop neighbors from each
parent.
