Gugrajah_Yuvaan_ Ramesh_2003.pdf

Simulation ofa Load Balancing Routing Protocol
c) Qi is the percentage of node i's transmit buffer that is empty.
Chapter 3
Node i uses the three metrics to obtain an evaluation value, Ai to attach to the route
request before rebroadcasting it. Ai identifies the current capabilities of node i in
terms of being a suitable intermediate node of the route and is calculated as follows:
(3-2)
where WAI , WA2 and WA3 are weighting factors. The route request is then rebroadcast
with the evaluation information and the process is repeated at each intermediate
node.
If there are N nodes in the network then there are R=N(N-I)/2 possible node pairs in
the network, each indexed r. Each node pair will have a possible M r routes between
the pairs terminal nodes, listed from best to worst, with the rnth route being indexed
rm. The destination node receives multiple route requests representing different
routes and sums the intermediate node evaluation values contained in each route
request to obtain an evaluation value Arm for the entire route r m. The route selected is
the route that maximizes the cost function
wm2
hrm wmlArm +--
(3-3)
where hrm is the number of intermediate nodes on route r m and Wml and W m 2 are
weighting factors.
DLAR scheme 4 combines the use of load information with the evaluation of the
signal quality being experienced at each node and the length of the route. By
monitoring the signal quality and using the routes that have lighter loads, delay is
decreased and congestion is alleviated. The reason nodes which have had more
collisions in the recent past are avoided is that the queues would generally be longer
at those nodes due to the problem of having to retransmit packets.
3-7