Seite - 361 - in Intelligent Environments 2019 - Workshop Proceedings of the 15th International Conference on Intelligent Environments

3.1. DescriptionofAgents This sectiondescribeseachagent inourapproach. • Requester Agent: is responsible of receiving requests from service client and forwardthemtoBroker Agent. It contains twomodules: i)Aninterfacemodule whichallowstootherAgents tointeractwiththisAgent. ii)Communicationmod- ule: it is amodule responsibleof the treatment themessages exchangedbetween thecurrentAgent and the restof theAgents. • Broker Agent: Itdealswiththeclientrequestsforsearchingthedesiredservices in the service registry. The returned services are sent to theWeighting Agent. It contains a communicationmodule; it saves the similarweb services in a local database. • Weighting Agent: It has a processingmodule which is responsible of calcu- lating the weight of the QoS criteria for each service that is received from the Broker Agent.Todoso, it uses theAHPmethod. • Ranking Agent: It allows to rank theweb services that are received from the Weighting Agent. After that, it provides the best service according the client requirements.ThisAgentuses theTOPSISmethod for the service ranking. 3.2. Functionaldescriptionof theapproach Here,we explain how the agents interact together in order to give an answer (best ser- vice) to the service client.As explained above the service provider has to publish a set of services in the service registry. The client sends to the system a request containing functional andnon functional criteria. TheRequester Agent receives the request and start communicateswith the other agents following the sequence diagrampresented in theFigure3. Figure3. Functionaldescriptionof theapproach Inthisfigure, theRequester AgentsendsanasynchronousmessagetotheBroker Agent tofindserviceswithadesiredQoS.Thelatter,sendsasynchronousmessagetothe UDDI.Asa resultBroker Agent receives a list of similar serviceswhich is forwarded H.Belouaaretal. /AHPandTOPSISMethods forWebServiceSelection 361