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Unleashing the potential of the Internet of Things 5

Figure 4 – Functional entities and interfaces of WoT-S CF

8.2.1 WoT service execution functional entity (WoT-S-EX FE)
The WoT service execution FE (WoT-S-EX FE) is responsible for executing the WoT service. The
WoT-S-EX FE enables the WoT service user to access and execute the WoT service. When an end
user (web client) wants to use the WoT service, the WoT-S-EX FE interacts with the
WoT-S-PM FE located in the WoT-S SF to check the authentication and the authorization of the
requester. Additionally, the WoT-S-PRM FE also checks availability of the service at that time.
The WoT-S-EX FE interworks with the WoT-S repository which includes logics to execute a
service. The WoT execution logics have a method for how to operate services.

The basic functionalities of the WoT-S-EX FE on managing logic are:
– storing and management logics describing an event in the WoT-S repository, a condition to
be satisfied by the event, and an action to be executed when the conditions are satisfied;
NOTE – When a service requester requests to register the logic, the logic is stored if and only if the
logic does not generate a static conflict in which the logic describes different actions upon the same
event and the same conditions for the action with other logics.
– retrieving a logic describing the event storage when an event occurs;
– inspecting the conditions whether or not the event satisfies a condition described in the
retrieved logic;
– executing an action described in the retrieved logic when the event satisfies the condition.

8.2.2 WoT service creation functional entity (WoT-S-CR FE)

The WoT service creation FE (WoT-S-CR FE) allows the WoT service to be developed by simple
composition of the existing WoT services on top of web-based things.

The WoT-S-CR FE is responsible for managing and executing mash-up WoT services. The
WoT-S-CR FE provides two functions: mash-up logic management and mash-up engine.

A WoT user is able to search, create or update service execution logic through mash-up logic
management via the web access. The service execution logic is stored and retrieved using the
WoT-S repository. A WoT user can also request a mash-up engine to operate the service execution
logic for the mash-up WoT service. Each unit of the WoT service for the mash-up service is
executed by the WoT-S-EX FE.

Rec. ITU-T Y.4414/H.623 (11/2015) 799