Affiliations: School of Computer Sciences, Universiti Sains
Malaysia, USM 11800, Penang, Malaysia. Tel.: +604 653 2062; Fax: +604 657
3335; E-mail: [email protected], [email protected]
Abstract: In most of the ad-hoc routing protocols, a static link lifetime (LL)
is used for a newly discovered neighbors. Though this works well for networks
with fixed infrastructures, it is inadequate for ad-hoc networks due to nodes
mobility and frequent breaks of links. To overcome this problem, routing
protocols with estimated LL using nodes affinity were introduced. However,
these protocols also used the static estimated LL during the connection time.
In contrast to that, in this paper two methods are presented to estimate LL
based on nodes affinity and then continually update those values depending on
changes of the affinity. In the first method, linear function is used to map
the relationship between the signal strength fluctuation and LL. In the second
method, fuzzy logic system is used to map this relationship in a nonlinear
fashion. Significance of the proposed methods is validated using simulation.
Results indicate that fuzzy method provides the most efficient and robust LL
values for routing protocols.
Keywords: Ad-hoc networks, AODV, link lifetime, fuzzy systems, intelligent networks