Abstract:
The centralized resource discovery approach in the Constrained Application Protocol
(CoAP) is based on the resource directory (RD) model, this directory contains a description for
resources held in the servers (sensors and actuators), in which the servers register their resources
in the RD while the clients are allowed to perform a lookup operation on these resources, and ask
for any resource using single request. In order of making the resource directory fully updated, all
nodes are periodically sending update messages (after fixed period of time) to the RD contains the
latest status of their information. However, these update messages will result in extra signaling
overhead and consume more power from node?s battery, this will drain the batteries and reduce
the overall network lifetime, as well as increase the probability of nodes failure. Thus, we have
proposed a dynamic tuning technique to adjust the update message interval in CoAP, the proposed
algorithm is depending on the battery level of the sending node, in which as battery level
decreased the update interval increased, this will reduce the signaling overhead and prolong the
node?s battery, which will reflect on the network and prolong its lifetime. Our approach is
evaluated using ContikiCooja simulator, where the results of experiments show that the dynamic
approach can extend the network lifetime by 25% in comparison with the network lifetime of the
standard CoAP