The routing protocol should provide an acceptable level of service even in the
presence of a large number of nodes. Newly added nodes should be identified
rapidly. In addition, the control packets must be utilized efficiently to deliver data
packets, and be generated only when necessary in order not to cause network
implosion when having a large number of nodes with frequent movements.
(d) Lack of Infrastructure and Central Control
Being ad-hoc networks, MANETs should be self-organizing and configuring;
there is no centralized administration entity to manage the operation of the dif-
ferent mobile nodes. The routing protocol should depend on distributed techniques
for network configuration and assigning roles for hierarchical structures (e.g.,
(e) Limited Bandwidth
As the nodes communicate using a wireless interface, the available bandwidth
is limited. The routing protocol should enhance bandwidth utilization for better
performance of the whole network. It should reduce the number of control packets
as much as possible and minimize the data packet header size while keeping the
protocol performance as efficient as possible.
All these design challenges should be taken into consideration in designing a
routing protocol for MANETs with the main focus being on the most critical
challenge: handling node mobility to maintain network connectivity.
Wireless Sensor Networks
Designing a routing protocol for WSNs is very challenging due to the WSN unique
characteristics that distinguish this type of network from other wireless networks.
The design challenges in sensor networks involve the following main aspects:
(a) Energy Constraints
Sensor nodes are restricted by their power supply as they are usually battery-
powered, and in most applications it is difficult or infeasible to replace or recharge
the batteries (e.g., in harsh environments). Having this power constraint, WSN
applications and protocols should be designed to be as energy-efficient as possible
to prolong both the node and network lifetimes.
(b) Limited Hardware Resources
The sensor node is also limited in its processing and storage capabilities,
therefore WSN protocols should be as simple as possible and with low data storage