Novel bat algorithm for QoS-aware services composition in large scale internet of things

The democratization of smart devices over the last decade has given rise what is called the Internet of Thing (IoT). In view of the multitude of functionally equivalent services that have different quality of service (QoS) levels, the services composition is one of the main challenges in the IoT environments where several devices interact with each other to perform a user's complex task. This paper proposes a QoS-aware services composition approach that exploits a novel bat algorithm (QC-NBA) to compose the best IoT services while considering user's constraints related to the QoS properties. Unlike most existing bio-inspired services composition approaches, the NBA method includes mechanisms that improve the exploration and exploitation of the composition search space. The bats habitat selection, the Doppler Effect compensation and the self-adaptive local search strategy of the NBA method speed-up the convergence and avoid the local optimum, enhancing therefore the performance of the QC-NBA algorithm in term of execution time and composition quality. The results obtained through the simulation scenarios, show that the QC-NBA approach achieves a good composition in terms of QoS utility and converges faster compared to other services composition baselines.