Connecting to the IoT

twitter

@UniSurreyIoT

Contact email

t.elsaleh@surrey.ac.uk

Tutorial: IoT Discovery

slideshare

UniSurreyIoT

Things connected?

• Data sent to context broker?

• What if you want to expose direct access to you things?

• You need to advertise them

– Register their availability

• Let users/applications know what your thing is about

– And how to reach it

Outline

• About

• NGSI-9

• Deployment

• Register

• Discovery

• Subscribe

• Update subscription

• Notify

3

IoT Discovery

About

• Technically: a service discovery mechanism– for announcing availability of context sources

via service endpoints

– Employs NGSI-9

• Synonyms: directory, registry, repository

• Analogy: “yellow pages”– Info about service provided, and how to

contact, but does not provide data

• IoT Architecture– Implementation of Configuration Manager GE

IoT Discovery

NGSI-9/10

• NGSI-9

– Context source availability

– Register, discover

• NGSI-10

– Context information retrieval

– Query, subscribe

• NGSI-9 is adopted in IoT Discovery

Why NGSI-9?

• Discover what is available

– Before querying for data

– Know where actual context sources are

• Not only relying on Context Broker

– Know what entities are available and what attributes they have beforehand

– Avoid unnecessary network overload of IoT services.

• IoT Services might be constrained

Target Users

• NGSI-9 Clients– Context Producers

• Any IoT Agent– Exposes a service endpoint for data/actuation provision via NGSI-10

(“data interface”)– e.g. gateway

• Data Handling GE– Register resources; sensing sources, actuators, processing elements

(composite of sensing sources)

• Backend device management GE– Register sensing sources, aggregated sensing sources

– Context Consumers• Applications• IoT Broker

– Discover entities on behalf of the consumers– retrieves, assembles, and processes information from the providers– offers consumers a simple interface and masking the complexity and

heterogeneity of the IoT

• Context Broker– Subscribes for notification of context source availability

1(a). Deploy IoT Discovery from image

• Prerequisite– To have a FIWARE Lab account

• Steps– Go to IoT Discovery catalogue page

– Follow the steps in “Deploying a dedicated GE instance based on an image” in the “Creating Instances tab”

– Check IoT Discovery is working using the “/sanityCheck” operation from your local computer• http://hostname:8080/ngsi9/sanityCheck

• Hints– Remember to set the security group properly

(typically to allow port 8080)

1(b). Deploy on your own running instance

• Alternative in the case you already have a VM in FIWARE Lab and don’t want to deploy another want

• Refer to Installation & Admin Guide• Prerequisite

– Java 8– mysql-server/client, tomcat7– Tested on Ubuntu 14.04 VM and Windows 7

• Steps– Download and extract package– Copy war files to tomcat /webapps folder

• Hints– Refer to installation and admin guide– Remember to set the security group properly (typically

to port 8080)

1(c). Interact with global instance

• Pre-requisites

– FIWARE Lab account

– Get Authentication token

– Auth-token inserted in request header

• X-Auth-Token: SAFJxc323dfiDS32IDEWF..

• Address of global instance

– iot-discovery.lab.fiware.org

– Port 80

IoT-Discovery API for NGSI-9

Interface

• Operations for context source availability– Registration– Discovery– Subscription– Update Subscription– Unsubscribe– Notification

• Standard– POST

• Convenience– GET, POST, UPDATE, DELETE (more RESTful)

What you will need to start

• A REST client

– Browser plugin

– Client program in your programming language.

API structure for Operations

2. Registration

• Prerequisites– Step 1

• Goal– Register an entity(s) to the NGSI-9 Server

• Standard Op– URL: http://{serverRoot}/ngsi9/registerContext

– Method: POST

– Payload: registerContextRequest

2. Register (Standard, Convenience)

• request • response

3. Registration Update

• Prerequisites

– Step 2 – registration done

• Goal

– Register an entity(s) to the NGSI-9 Server

• Standard Op– URL: http://{serverRoot}/ngsi9/registerContext

– Method: POST

– Payload: registerContextRequest

3(b). Register Update (Standard, Convenience)

• request • response

4. Discover

• Prerequisites– Step 2 – registration done

• Goal– Discover an entity(s) at the NGSI-9 Server

• Standard Op– URL: http://{serverRoot}/ngsi9/discoverContextAvailability

– Method: POST

– Payload: discoverContextAvailabilityRequest

4(a). Discover (Standard)

• request • response

4(b). Discover (Convenience)

• request • response

5. Subscribe

• Prerequisites– Step 4 – no results from discovery

• Goal– Subscribe to availability of an entity(s) to the NGSI-9

Server

• Standard Op– URL: http://{serverRoot}/ngsi9/subscribeContextAvailability

– Method: POST

– Payload: subscribeContextAvailabilityRequest

5(a) Subscribe (Standard)

• request • response

6. Update Subscription

• Prerequisites– Step 5 – Already subscribed

• Goal– Update Subscription to availability of an entity(s) to the NGSI-9

Server

• Standard Op– URL: http://{serverRoot}/ngsi9/updateContextAvailabilitySubscription

– Method: POST

– Payload: updateContextAvailabilitySubscriptionRequest

6(a) Update Subscription (Standard)

• request • response

7. Unsubscribe

• Prerequisites– Step 5 – Already subscribed

• Goal– Unsubscribe to availability of an entity(s) to the NGSI-9 Server

• Standard Op– URL: http://{serverRoot}/ngsi9/unsubscribeContextAvailability

– Method: POST

– Payload: unsubscribeContextAvailabilityRequest

7(a) Unsubscription (Standard)

• request • response

8. Notification

• Prerequisites– Step 5: Subscription already done

• Goal– Notify availability of an entity(s) to an NGSI-9 subscriber

• Standard Op– URL: http://{serverRoot}/ngsi9/notifyContextAvailability

– Method: POST

– Payload: notifyContextAvailabilityRequest

8(a) Notification (Standard)

• request • response

Resources

• Slideshare:• http://www.slideshare.net/UniSurreyIo

T/iotdiscoverytutorial• FIWARE Wiki

– Catalogue– Installation and Admin guide– FI-WARE NGSI Open RESTful API

Specification– User’s and Programmer’s guide– Unit Tests for NGSI-9 Server

Thanks!Thanks!

FIWARE and IoT

• Provide Generic Enablers for IoT Service Enablement

• enable “things” to become citizens of the Internet– available, searchable, accessible, and

usable

• for Applications to create value from real-world interaction – enabled by ubiquity of heterogeneous and

resource-constrained devices.