Spatially Cohesive Service Discovery and Dynamic Service Handover for Distributed IoT Environments.

The proliferation of the Internet of Things (IoT) enables the provision of diverse services that utilize IoT resources distributed in ad-hoc network environments. This has resulted in a new challenge, the issue of how to efficiently and dynamically discover appropriate IoT services that are necessary to accomplish a user task in the vicinity of the user. In this paper, we propose a service discovery method that finds IoT services from a user’s surrounding environment in a spatially cohesive manner so that the interactions among the services can be efficiently carried out, and the outcome of service coordination can be effectively delivered to the user. In addition, to ensure a certain Quality of user Experience (QoE) level for the user task, we develop a service handover approach that dynamically switches from one IoT resource to an alternative one to provide services in a stable manner when the degradation of the spatial cohesiveness of the services is monitored. The spatio-cohesive service discovery and dynamic service handover algorithms are evaluated by simulating a mobile ad-hoc network (MANET) based IoT environment. Then, various service discovery strategies are implemented on this simulation environment, and several options for the service discovery and handover algorithms are tested. The simulation results show that compared to various baseline approaches, the proposed approach results in a significant improvement in the spatial cohesiveness of the services discovered for user tasks. The results also show that the approach efficiently adapts to dynamically changing distributed IoT environments.