At home, the PRECIOUS system will offer services to end users: monitoring of the home environment factors (e.g., air quality), gathering data from “health & wellbeing” devices (e.g., body weight scale) and sending feedbacks on home devices (e.g., lamp blinking, messages on TV screen or computer screen, etc.).
However, one of the key issues in the home automation domain is the interoperability between heterogeneous devices and protocols. It might be a problem for end users but also for developers of new applications or services like in the PRECIOUS system.
Nowadays, there is a lack of standardization in the home automation systems. In the past ten years, a lot of initiatives, alliances or standards appeared like ZigBee, EnOcean or Z-Wave but they still do not propose interoperability with other alliances or standards. In the same time, the Ambient Assisted Living domain has proposed different solutions mainly based on IP to fight interoperability issues between heterogeneous devices. For more details, we refer the reader to the deliverable D4.1 of the PRECIOUS project.
Telecom Bretagne has proposed xAAL in order to allow the communication between different home automation devices (sensors/actuators) in a home area network. xAAL is a distributed infrastructure for heterogeneous ambient devices. The communication between devices is realized by a lightweight xAAL messaging protocol working on the so-called xAAL bus. The whole infrastructure is based on well-known existing protocols: multicast IPv4/IPv6 UDP.
xAAL will offer the opportunity to use together devices from different manufacturers and technologies. xAAL will also provide a transparent sensors/actuators layer for developers of applications, e.g. well-being application with PRECIOUS. The multiplicity of low-level home automation protocols are hidden by an upper-level generic interface.
How to share information between a smart home and the PRECIOUS platform
The interaction between a smart home and the PRECIOUS system is organized in the two directions: the communication from the user’s home to the PRECIOUS server (uplink), and the communication from the PRECIOUS server to the user’s home (downlink). To realize this uplink/downlink communication, a publish/subscribe protocol is mandatory. For this task, MQTT, a M2M communication protocol, appeared to be well adapted.
The uplink allows to push all data considered as useful (by the user) to the PRECIOUS system. The figure below describes the architecture. The MQTT-xAAL relay sends data from the smart home. The MQTT broker allows to dispatch data to subsribers, e.g. the PRECIOUS server. Then, the MQTT-logger stores data in the PRECIOUS database.
The downlink will be used by PRECIOUS to activate the scenarios inside the user home or to advertise the user with notifications also called user feedbacks. The MQTT-xAAL relay “subscribes” to PRECIOUS home-scenarios (i.e. topics) . The PRECIOUS scenarios are for example : « blink lamp in the living room », « PRECIOUS notification on TV screen », etc. The MQTT-actuator is a component in the PRECIOUS Cloud Server allowing activating PRECIOUS home-scenarios from PRECIOUS applications.
xAAL is a solution open to the community. For more details, please have a look to our project webpage: http://recherche.telecom-bretagne.eu/xaal/.
Public access on our repository:
svn co https://svn.telecom-bretagne.eu/svn-public/xAAL/
Motivated contributors are invited to contact us for a read-write access on:
svn co https://svn.telecom-bretagne.eu/repository/xAAL/
Finally, all developments for the project will be shared on the githbub repository of the PRECIOUS project: