ITU-T Recommendations

The Continua Design Guidelines (CDG) defines a framework of underlying standards and criteria that ensure the interoperability of devices and data used for personal connected health services. It also contains design guidelines (DGs) that further clarify the underlying standards or specifications by reducing options or by adding missing features to improve interoperability.

Recommendation ITU-T H.812.3 defines the additional design guidelines for the Capability Exchange-enabled PHG and health and fitness services certified capability class (CCC). The purpose of the Capability Exchange is to reduce the amount of information that must be pre-configured on a device in order to obtain plug and play interoperability. Specifically, Capability Exchange enables application hosting devices, such as a personal health gateway (PHG) to know what types of messages it can send to the health and fitness services, by identifying its Continua CCCs. Likewise, Capability Exchange provides a mechanism for the PHG to inform the health and fitness services of its capabilities. This enables the health and fitness services to tailor its communication with the PHG. Capability Exchange is mandatory for all health and fitness services while it is optional for PHGs.

It is assumed that the PHG is pre-provisioned with a URL, or a set of URLs, denoting the service endpoint of one or more health and fitness services. The Capability Exchange process takes place when the PHG first contacts the health and fitness services. It may also take place intermittently, to update the information received in the first Capability Exchange. In most cases, the set of Continua CCCs implemented at the health and fitness services changes slowly, if at all. Therefore, it is expected that the PHG can store the information about services capabilities and optionally, implement a policy for periodically updating that cache. A PHG might identify several health and fitness services in this way and communicate with one or more of these for different purposes.

The health and fitness service describes the information about its supported CCCs in a file called "root file". The root file is a special resource that describes the properties of CCCs and how a PHG can start information exchange with these CCCs. The root file and other features of the exchange come from an HL7 standard called hData. hDatas not only defines the root file format, but also defines the operations for exchanging root files, using HTTP using GET and POST operations, often referred to as "REST" (for representational state transfer).

Each Continua CCC (in addition to Capability Exchange) will use the root file to document information relevant to that capability, including the capability name, the information that can be exchanged under the capability and its format and URLs for REST operations, if supported by that capability. Details are given in the documentation for the respective Continua CCCs.

Recommendation ITU-T H.812.3 is part of the "ITU-T H.810 interoperability design guidelines for personal connected health systems" subseries that covers the following areas:

– ITU-T H.810 – Interoperability design guidelines for personal connected health systems: System overview

– ITU-T H.811 – Interoperability design guidelines for personal connected health systems: Personal health devices interface design guidelines

– ITU-T H.812 – Interoperability design guidelines for personal connected health systems: Services interface design guidelines

– ITU-T H.812.1 – Interoperability design guidelines for personal connected health systems: Services interface: Observation upload capability

– ITU-T H.812.2 – Interoperability design guidelines for personal connected health systems: Services interface: Questionnaires capability

– ITU-T H.812.3 – Interoperability design guidelines for personal connected health systems: Services interface: Capability Exchange capability

– ITU-T H.812.4 – Interoperability design guidelines for personal connected health systems: Services interface: Authenticated persistent session capability

– ITU-T H.813 – Interoperability design guidelines for personal connected health systems: Healthcare information system interface design guidelines