Page 810 - Unleashing the potenti al of the Internet of Things

5 Unleashing the potential of the Internet of Things

– WoT service control functions (WoT-S CF): They control the WoT service which are
registered in the WoT service providers. It is responsible for executing and creating the
WoT service and mash-up services.

– WoT resource management functions (WoT RMF): They contain resource information
(things information) which is used by and registered at the WoT service functions.

7.2 Web resource functions
The web resource functions have responsibility for accessing the things by enabling web
technologies. If there are no relevant web technologies to access the things (devices) directly, the
WoT broker function should be used which provides access to the devices on the web. Also it is
responsible for integrating the web resources (e.g., fully-fledged device and constrained device) to
the web [ITU-T Y.4400]. If it is a virtual thing, it can be accessed directly by the WoT resource
management function. The T2R function has a role for integrating and exposing things to the web
resources. In [ITU-T Y.4400], the service layer of the WoT broker is responsible for the T2R role.
And, the things adaptation functions are responsible for adaptation.

7.3 Web client
With the web client, an end user can use WoT services provided by an accessed physical device or
virtual thing. The web browser and web applications allow the web client to use WoT services. The
web client can control devices by using a web browser and web technologies such as HTTP,
RESTful API etc.

7.4 Things

In the WoT service, the things can be classified into two types; physical things and virtual things.
The physical things can be classified into two types of devices, constrained devices and fully-
fledged devices. The things can be accessed and exposed on the web as a WoT service.

7.4.1 Physical things

7.4.1.1 Constrained device
The constrained device is a non-capable device to connect to the Internet or web alone. And it has
no functionality of web. It has just its own proprietary interfaces and protocols such as ZigBee,
Bluetooth, NFC, etc. These interfaces and protocols do not have interoperability with web
technologies. In this case, the devices need the WoT broker. By exposing on web through the WoT
broker, the devices can communication with the WoT broker using their proprietary interface. And
the WoT broker has a role of agent for these devices in order to communicate with the web user.

7.4.1.2 Fully-fledged device
The fully-fledged device is a device to support direct web connectivity functionalities, therefore
there is no need to translate HTTP requests from the web clients into the appropriate protocol.
However, to enable this capability, the web server is built in the devices itself.

The fully-fledged device is necessary to satisfy the following two capabilities:
– support of TCP/IP protocol suite
– web server.

These capabilities enable devices seamless integrating to the web and their functionality through the
web interface.

7.4.2 Virtual things

The virtual things are information world objects such as media, image, video and documents, etc.
These objects are web resources exposing through the web service.

796 Rec. ITU-T Y.4414/H.623 (11/2015)