A QoS-driven approach for service-oriented device anycasting in ubiquitous environments

The vision of pervasive computing is to let users enjoy ICT-enabled services in an "any time, anywhere, on any device" manner. It aims to supply ubiquitous services through communications among a set of devices deployed in a ubiquitous environment. Due to the diverse QoS needs of different kinds of ubiquitous services and users, it is a critical challenge to select an optimal set of devices with the objective of achieving service-specific QoS goals like low packet loss, short packet delay, and high energy efficiency. In this paper, the problem is first formulated as the service-oriented device anycasting problem (SDAP) and then proved as an NP-complete problem. By adopting a tree-based service representation model, Basu et al. proposed the dynamic task-embedding anycasting (DTA) approach. This approach effectively solves the SDAP in a distributed way. However, the service quality is likely sacrificed because the tree scheme does not sufficiently describe a ubiquitous service. In this paper, we propose a novel approach called the service-oriented device anycasting (SDA) approach that adopts a graph-based service representation model called the service profile (SP). By introducing a layered structure into the SP, the SDA approach can reach a compromise between service quality and computational complexity. In addition, the QoS-driven utility function is proposed to quantify service quality by matching the capabilities of heterogeneous devices to various QoS needs. Finally, the simulation results show that the SDA approach outperforms the DTA approach by saving roughly 20% of device energy and prolonging the network lifetime. Packet loss and packet delay are also improved by roughly 25% and 8%, respectively. The advantage of the SDA approach is more obvious in environments with highly mobile devices and multiple users.