(c) Dense Deployment
Sensor nodes are often deployed in large numbers and this number can be
several orders of magnitude higher than that in a MANET; there can be hundreds
of thousands of nodes in very large areas. The WSN protocol should work effi-
ciently with this number of nodes and try to reduce the communication and control
overhead that may cause network congestion and performance degradation.
(d) Addressing Scheme
Due to the dense deployment in WSNs, it is not possible to build a global
addressing scheme. Thus, the IP-based protocols may be not applicable to WSNs.
In addition, in WSNs, nodes collaborate together to achieve the overall application
goals and perform the sensing tasks. In most cases, there is no interest in which
particular node reported the data—the interest is in the reported data itself and not
in which node it was sent from. The common addressing scheme in WSNs is a
data-centric scheme which is based on attribute-based addressing, where data is
represented as an attribute-value pair that may be requested by queries sent by the
base station or reported by the node in a time-based or event-based manner.
Nodes are deployed densely in a WSN and more nodes may be added during the
network operation to provide more coverage or accuracy. The protocol should
accommodate all these nodes and be scalable to different network sizes.
Being an ad-hoc network, it is the responsibility of the nodes to configure
themselves on the fly once deployed and to organize themselves into a commu-
nication network. The routing protocol should provide distributed techniques to
support this feature.
(g) Fault Tolerance
Due to the limited resources, sensor nodes are prone to failure either through
hardware failure or depleted batteries. This failure also may be due to environ-
mental factors and unattended operation. The protocol for a WSN should be fault
tolerant, handle frequent topology changes, and utilize self-repairing and self-
(h) Data Redundancy
Due to the dense deployment of the sensor nodes, there are many nodes in an
area of interest. The data sensed by these nodes are based on a common phe-
nomenon and have some sort of correlation and redundancy. Exhausting the net-
work with this redundant data causes problems with unneeded energy consumption