A variety of different types of devices may serve as
nodes in a Mobile Ad hoc Network (MANET). Every node must be equipped with a
transmitter and receiver in order to allow wireless communication, however
each may have a different set of abilities. Typically, the functionalities
and resources available to the node are suited to the device's particular
purpose and requirements.
Participation in a MANET places a burden on a node, in
addition to its primary functions. Each node is asked to also forward
packets for the rest of the network. This consumes some or all of a node's
resources, including processing time, energy stores, and network bandwidth.
Depending on the amount of routing demand placed on a node, the additional
routing load may reduce or drain a node's available resources. A node may
then be forced to restrict its own operations, or even shut down, abandoning
A node is required to participate in the routing process
in order for the network to effectively deliver its traffic. The load placed
on the node is dependent on the routing protocol used in the network. In
most ad hoc routing protocols, a node has little choice as to how much
forwarding it must perform. If it feels it cannot perform these duties, or
chooses not to, for whatever reason, it has only two choices: to break the
rules of the routing protocol, or to withdraw from the network. Both
solutions will have a negative impact on the network as a whole.
The Degree-of-Participation-concept provides nodes with a
method for varying their level of involvement in the network. Based on the
degree a node agrees to participate in the network, a
Degree-of-Participation-based routing protocol distributes a larger or
smaller portion of the routing load to the node. The actual process of
deciding their own participation degree is left to the nodes themselves. The
individual nodes may each set their own internal policies for determining
their participation, rather than requiring the establishment of a uniform,
network-wide resource policy.
Some of the important issues that we are investigating