To support QoS routing, accurate state information (such as energy
level and queue length) should be available and manageable. But due to
bandwidth constraints, communication costs, high loss rate and the dynamic
topology of MANETs, getting and keeping up-to-date state information is a very
complex task, if at all feasible. In this work, we use Optimized Link State
Routing (OLSR) as the underlying routing protocol.
This research reports the quantification of state information accuracy under
different traffic rates. State information accuracy is
defined as how far off is the believed QoS-related
state information from its actual value. The results show that state
information is inaccurate, especially under high traffic rates. Tuning the OLSR
protocol parameters has no noticeable impact on inaccuracy levels.
Based on our inaccuracy level analysis, we proposed three additional techniques
for the energy level metric and two techniques for the queue length metric as
an attempt to reduce inaccuracies. We compare the different techniques against
each other and against the basic OLSR. For energy level, two of our proposed
techniques have shown significant improvements in inaccuracy levels. On the
other hand, no improvement was observed for queue
length related techniques.