QoS Routing for Heterogeneous Mobile Ad Hoc Networks Based on Multiple Exponents in the Definition of the Weighted Connectivity Index

Abstract

In decades, lots of QoS routing algorithms have been proposed to let each mobile node in ad hoc networks to find paths based on QoS metrics which are mainly bandwidth and delay. We also proposed to use both Connectivity Index (CI) and weighted CI, the mathematically combination of link capacity and CI, as the QoS metrics in ad hoc networks. CI is widely used topological index in chemical and mathematical applications. By considering this CI in path computation process, the returned paths are more stable which directly affect throughput and packet delivery ratio of the networks. However, this CI is computed in one dimension only where the exponent or a in the definition of CI is set to-(1/2). CI with this a = -(1/2) is the most successful topological index which has received lots of attentions from chemists and mathematicians. However, the other exponents were also studied as the special case of CI. In this work, we propose to use Shortest-Highest Path algorithm to select the best feasible path in terms of the highest weighted CI and shortest delay link where multiple exponents in weighted CI are applied. We construct simulations in various scenarios to study the effects of these multiple exponents on the heterogeneous ad hoc networks which is more realistic. Since in real applications, multiple types of nodes exist and they usually have different capabilities. Thus, the QoS routings which perform well in homogeneous networks may not be much effective in heterogeneous networks. From the simulation results, it is obvious that Shortest-Highest Path algorithm with weighted CI can also improve the network performances in heterogeneous ad hoc networks.