The design and implementation of architectural components for the integration of the IP multimedia subsystem and wireless actuator networks

Wireless actuators are small scale devices that can act on their environment. The IP multimedia subsystem is an architecture with the goal of seamlessly delivering multimedia services. Combining actuation capabilities with the IMS will certainly enable novel value-added services in areas such as environment monitoring, emergency management and home automation. We have previously proposed an architecture for such integration. This architecture relies on two key components: an actuation control function (ACF) that serves as a higher-level actuation control entity, and a wireless actuators/IMS gateway (WAG) dealing with the interworking between actuator networks and the IMS. In this article, we focus on the design and implementation of the ACF and the WAG. Furthermore, a prototype application is implemented to show how new applications can be built using our integrated architecture. Performance has also been evaluated, and several lessons were learned in the course of this work. One lesson is that integrating the IMS with various and evolving actuators is a continuous task. Without standard APIs for the interaction with actuators produced by different vendors, the WAG needs to be constantly upgraded. Another lesson is that while the introduction of actuation as an application building block in the IMS enables fast and easy development of applications with actuation requirements, the lack of mature IMS application development toolkits remains a barrier.