Web of Things architecture

27th January, 2016Panasonic, Fujitsu

W3C Web of Things Interest Group

Abstract architecture on TPAC 2015

Copyright 2016 Panasonic, Fujitsu

Abstract model noted at TPAC 2015 Face-to-Face

Features of WoT Servient Can serve either (or both) as a server and

a client, using bi-directional communication Can connect legacy devices Device abstraction through the concept of

Resources and Protocol mapping Script API provides access to devices

2

This is an attempt to re-formulate the model using the four implementation models introduced by Panasonic

Modified diagram of the basic WoT servient architecture

Copyright 2016 Panasonic, Fujitsu

Functional architecture of WoT ServientScript:Provides access to and control of internal data of devices connected to WoT servient according to WoT API interaction

Resource Management:Manages status of connected devices, request ques and so on.

Protocol Mapping:Converts interactions with devices using information in TD in accordance with lower layer protocols. For legacy devices, adapters available for those devices convert the protocol.

Communication protocol:Protocol used in actual communication with objects. In the case of physical devices, every protocol that is necessary to communicate with those devices is installed.

WoT Servient

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

Legacy comm.

Physical API Client API Server API

Adapter

ThingsDescription

Legacydevice

WoT Servient WoT Servient

WoT APIPropriety interface

3

Physical APIProvider

Client APIProvider

Serverl APIProvider

Web Server Web Client

Things DescriptionDeclares providing API name, parameter type and so on.External client refers this description to call WoT APIs

API ProviderInterprets scripts, retrieves information of devices connected to WoT servient in conjunction with Resource Management.

Simple example for WoT

Copyright 2016 Panasonic, Fujitsu

Controlling WoT devices from Browser Browser access to information of and control devices by using scripts to

access devices through WoT Servient. Device semantics (TD) are referred by browser script

Legacydevice

Browser

App Script

Web Client

4

WoT Servient

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

Legacy comm.

Physical API Client API Server API

Adapter

ThingsDescription

Physical APIProvider

Client APIProvider

Serverl APIProvider

Protocol Mapping

ResourceManagement

Client APIProvider

Client API

WoT API

(A) WoT servient on device (WoT device)

Copyright 2016 Panasonic, Fujitsu5

Device is a WoT servient, directly interprets WoT API Browser is a WoT servient that serves only as Web client Application is a full-fledged WoT servient

WoT Servien(Wot Devicet)

Web ServerWeb Client

Protocol Mapping

Resource Management

Script

Browser

Web Client

ProtocolMapping

Resource Management

Script

WoT Servient(Applications)

Web ServerWeb Client

Protocol Mapping

Resource Management

Script

Script can supplement functions not implemented by the device

Physical APIProvider

Client APIProvider

Serverl APIProvider

Client APIProvider

Serverl APIProvider

Client APIProvider

ThingsDescription

WoT Servient

(B) WoT servient on Smartphone

Copyright 2016 Panasonic, Fujitsu6

WoT Servient

Web ServerWeb Client

Protocol Mapping

Resource Management

(UX) App Script

Legacycomm.

Legacydevice

Browser

Web Client

ProtocolMapping

Resource Management

UX App Script

Smartphone

Client APIProvider

Physical APIProvider

Client APIProvider

Serverl APIProvider

ThingsDescription

WoT Servient Runtime

Web ServerWeb Client

Protocol Mapping

Resource Management

UX App Script

Legacycomm.

Legacydevice

Physical APIProvider

Client APIProvider

Serverl APIProvider

ThingsDescription

Smartphone

WoT servient on Smartphone From the relationship of Wot Servient and UX App script point of view, there are 2 types

One is browser calling inside WoT Servient model, the other is WoT Servient itself providing UX Nevertheless the difference of view, WoT servient architecture is logically the same in both models.

(C) WoT Servient on Smart Home Hub

Copyright 2016 Panasonic, Fujitsu7

WoT servient as a specialized device named “Hub”, connecting devices and applications. Browser is a WoT servient that serves only as Web client Application is a full-fledged WoT servient

WoT Servient

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

Legacycomm.

Legacydevice

Browser

Web Client

ProtocolMapping

Resource Management

App Script

WoT Servient(Application)

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

Smart HomeHub

Client APIProvider

Serverl APIProvider

Client APIProvider

Physical APIProvider

Client APIProvider

Serverl APIProvider

ThingsDescription

Browser

Web Client

Protocol Mapping

ResourceManagement

App Script

Client APIProvider

Application

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

Client APIProvider

Serverl APIProvider

(D) WoT Servient on Cloud Server

Copyright 2016 Panasonic, Fujitsu8

WoT servient installed both in cloud and LAN, connecting cloud application and devices in LAN each other Gateway (local) WoT servient holds latest information about connected devices

Platform(cloud) WoT servient cashes copy of Gateway’s Resource information, routing browser/application’s access to devices

WoT Servient

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

WoT Servient

Web ServerWeb Client

Protocol Mapping

Resource Management

App Script

Legacy comm.

Legacydevice

Hub

Cloud

Platform stores chashe of Gateway’s Resource information

Platform

Physical API

ProviderClient APIProvider

Serverl APIProvider

Client APIProvider

Serverl APIProvider

ThingsDescription

ThingsDescription