Page 2 Lecture Notes in Computer Science 2865 Edited by G. Goos ...
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Page 2 Lecture Notes in Computer Science 2865 Edited by G. Goos ...
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274 M.K. Denko and Q.H. Mahmoud3.1 Ma<strong>in</strong>ta<strong>in</strong><strong>in</strong>g Rout<strong>in</strong>g and Cluster<strong>in</strong>g InformationIn our proposed architecture, each node has a Rout<strong>in</strong>g Mobile Agent (RMA) and aCluster<strong>in</strong>g Static Agent (CSA). These agents operate on top of an agent platformrunn<strong>in</strong>g on top of a Java virtual mach<strong>in</strong>e suitable for mobile devices such as the KiloVirtual Mach<strong>in</strong>e (KVM). The CSA ma<strong>in</strong>ta<strong>in</strong>s cluster<strong>in</strong>g <strong>in</strong>formation <strong>in</strong> a cluster<strong>in</strong>gtable. The cluster<strong>in</strong>g table conta<strong>in</strong>s IDs of neighbors, the node role (ord<strong>in</strong>ary node,gateway or clusterhead), mobility <strong>in</strong>formation, nodal degree and signal strength. Therout<strong>in</strong>g mobile agent moves across the network to collect and ma<strong>in</strong>ta<strong>in</strong> rout<strong>in</strong>g tableswhile the cluster<strong>in</strong>g agent gathers and ma<strong>in</strong>ta<strong>in</strong>s cluster<strong>in</strong>g <strong>in</strong>formation.All <strong>in</strong>ter-cluster rout<strong>in</strong>g is performed via the clusterhead. On receiv<strong>in</strong>g a packetfrom a node, the clusterhead forwards the packet to the preferred gateway which <strong>in</strong>turn forwards it to the adjacent cluster. In the event that the clusterhead does not havethis <strong>in</strong>formation, it can deploy the mobile agent to get the route to the target dest<strong>in</strong>ation.Rout<strong>in</strong>g and cluster<strong>in</strong>g table entries at the clusterheads are updated periodicallywith up-to-date values based on timestamps.To localize the agent mobility, the rout<strong>in</strong>g agent <strong>in</strong> a mobile node migrates onlywith<strong>in</strong> its cluster. The rout<strong>in</strong>g mobile agent also updates rout<strong>in</strong>g and cluster<strong>in</strong>g <strong>in</strong>formationdur<strong>in</strong>g each visit. The agents at the clusterhead also ma<strong>in</strong>ta<strong>in</strong> <strong>in</strong>formationabout other clusterheads and gateways. The cluster<strong>in</strong>g agent elects a clusterheadbased on the cluster<strong>in</strong>g <strong>in</strong>formation ma<strong>in</strong>ta<strong>in</strong>ed at each mobile node. Once the cluster<strong>in</strong>garchitecture stabilizes, each node will have a complete knowledge of itsneighbors.We have devised a migration strategy for rout<strong>in</strong>g mobile agents. To f<strong>in</strong>d a route,the Rout<strong>in</strong>g Mobile Agent (RMA) uses the follow<strong>in</strong>g algorithm:IF the RMA does not have the routethenThe RMA moves to the Clusterhead<strong>in</strong> that Cluster;The RMA communicates with theClusterhead;IF the Clusterhead has the rout<strong>in</strong>g <strong>in</strong>fothenThe RMA goes back and updates routes;ElseRMA <strong>in</strong> clusterhead cont<strong>in</strong>ues route search<strong>in</strong> other Clusters;END IFEND IF3.2 Mobile Nodes and Inter-agent CommunicationEach mobile agent will be given a temporary workspace to perform its functions andalso to allow multiple mobile agents to co-exist <strong>in</strong> a host. A host<strong>in</strong>g node can receivenew agents or transport them to other nodes without caus<strong>in</strong>g any <strong>in</strong>terference. Theagent system hides details about the node and provides access to local resources withthe necessary security mechanisms.