iotivity

Table of Contents Overview Websites Basics The CoAP Protocol Functionalities Resource Registration Resource Discovery Get Resource Status Set Resource Status Observe Resource State Services Control Manager DeviceFinderListener NotificationListener Things Manager Notification Manager Protocol Plugin Manager Soft Sensor Manager

Overview

Websites

• OIC: http://openinterconnect.org/
• iotivity website: https://www.iotivity.org/
• iotivity-dev mailing list: http://lists.iotivity.org/pipermail/iotivity-dev/
• Programmer's guide: https://www.iotivity.org/documentation/linux/programmers-guide
• SmartHome demo: https://01.org/smarthome
  • github: https://github.com/01org/SmartHome-Demo
  • https://github.com/01org/SmartHome-Demo/tree/master/sensors/ocf_temperature_sensor

Basics

• Based on REST API (GET/PUT/POST/DELETE)
  • RESOURCE: A resource is a component of a device which supports GET, PUT, POST, DELETE operations (cf. HTTP)
    • A device consists of resources.
    • e.g. A garage door opener is a resource, which consists of two sub-resources -- light and lock.
    • e.g. One get apply GET operation over a resource to obtain its current state.
• OPERATIONS: GET, SET, OBSERVE
• Features: https://www.iotivity.org/documentation/features
  • Resource registration: add a resource to IoTivity space
  • Resource discovery: search for a resource OR be notified of availability resource
  • Device discovery with filtering
  • Property attributes (GET/SET/OBSERVE)
  • Resource tree
  • Presence notification service defined as a virtual resource
    • Registrating a resource
    • Finding a resource
    • Querying resources
    • Setting a resource state
    • Observing a resource state

The CoAP Protocol

• Currently, IoTivity only supports CoAP (Constrained Application Protocol) over UDP/IP
  • CoAP is quite similar to HTTP
  • They plan to support HTTP over TCP/IP later.
• CoAP message format:
  • address: 192.168.8.102:56383
  • type: CON (confirmable), NON (non-confirmable), ACK, RST (reset)
  • token: length of token (0 ~ 8)
  • code: Request (GET:0.01, SET:002, ...), Success (CREATED:2.01, CHANGED(2.04), CONTENT(2.05), ...), Client Error* (4.xx), Server Error (5.xx)
  • message ID: 0xXXXX (16-bit), generated by sender and allows receiver to de-duplicate requests
  • token: generated by client to match REQ to RESP
  • options: URI-paths + URI-queries (e.g. /oc/core?rt=core.sensor&if=core.mi.il)

Functionalities

Resource Registration

• Registrating a resource
• To register (introduce) a resource, say R, to the IoTivity space, the following are required:
  • request handler for R: the code which will be executed on GET/SET/OBSERVER request over **R**
  • URI path for R: i.e. the _name_ under which others will refer to this resource
• What happens in device registration
  • obtain OCPlatform C++ object (maybe Singleton), `platform`
  • platform.registerResource(&handle, "/light/1", "light", "oc.mi.def", handler, OC_DISCOVERABLE)
    • /light/1: URI-path
    • light: resource type (predefined set of well-known resource types)
    • oc.mi.def: interface -- i.e. which operations are allowed over this resource
    • handler: function which implements operations
    • OC_DISCOVERABLE: resource should be reported to the client, when a client performs a resource discovery
  • This call will eventually be changed to C function call: OCCreateResource(&handle, "light", "oc.mi.def", "/light/1", handler, OC_DISCOVERABLE)

Resource Discovery

• Finding a resource
• What happens in device registration
  • obtain OCPlatform C++ object (maybe Singleton), `platform`
  • platform.findResources("", "coap://224.0.1.187/oc/core?rt=alpha.light", findHandler)
    • "": URI authority (target host), when empty, it's for all nodes
    • "coap://224.0.1.187/oc/core?rt=alpha.light": URI path and URI query
      • "/oc/core": URI path indicates resource
      • "rt=alpha.light": URI query is the filter

Get Resource Status

• Querying resources

Set Resource Status

• Setting a resource state

Observe Resource State

• Observing a resource state

Services

Control Manager

DeviceFinderListener

NotificationListener

Things Manager

Notification Manager

Protocol Plugin Manager

Soft Sensor Manager