Use of non-monotonic utility in multi-attribute network selection

Network convergence across different access technologies holds a promise of enabling ubiquitous service availability but faces several technical challenges. With anticipated proliferation of multimode IP devices, the optimal selection of a service delivery network among multiple IP based wireless access alternatives is one of the important issues that is actively studied and discussed in several standardization forums. Use of multi attribute decision making (MADM) algorithms has been proposed in the past for network selection decisions in a heterogeneous wireless network environment. A direct comparison of these algorithms is difficult as this would require the use of another MADM algorithm. A better approach instead is to ascertain the appropriateness of the algorithm to the problem space. This paper provides the basis for evaluating the appropriateness of MADM algorithms for network selection. It analyzes the use of MADM algorithms such as TOPSIS, ELECTRE and GRA for network selection and argues that GRA provides the best approach in scenarios where the utilities of some of the attributes are non-monotonic. The paper proposes a novel stepwise approach for GRA that uses multiple reference networks and explains its working with network selection scenarios.