Wireless Sensor Networks

Transcription

1 Wireless Sensor Networks Office Hours: Tuesday 3 5 Main Building, second floor Credits: 6

2 Protocol Stack Time Synchronization Energy Efficiency Application Layer Network Layer MAC Layer Localisation PHY Layer

3 Zigbee Application Layer The Application Layer consists of: APS (Application Support Sub-layer), ZDO (Zigbee Device Objects) and the Application Framework

4 Application Support (APS) Sub-Layer The Application Support sub-layer (APS) provides an interface between the network layer (NWK) and the application layer (APL). The APS sub-layer supports two types of service: data and management. The APS data service is provided by the APSDE (Data Entity) and is accesses through the APSDE-SAP. The APS management service is provided by the APSME (Management Entity) and is accesses through the APSME-SAP.

5 APS Data Entity The APSDE (Data Entity) will provide the following services: - Generation of the application level PDU (APDU) - Reliable transport: end-to-end retries - Duplicate rejection: messages offered for transmission will not be received more than once - Fragmentation: segmentation and reassembly of messages longer than the payload of a single NWK layer frame

6 APS Data Entity The APSDE (Data Entity) supports the transport of application protocol data units between peer application entities.

7 APS Management Entity The APSME (Management Entity) will provide the following services: -Binding management: to match two devices (APP objects) together based on their services and their needs. This service is called the binding service, and the APSME shall be able to construct and maintain a table to store this information. -AIB management: to get and set attributes in the devices AIB (Application support layer information base).

8 Binding: An Example APP Objects (Devices) Cluster Binding

9 APS Management Entity ZC ZED Client Device On/Off Switch Device Server Device On/Off Light Device Client Cluster On/Off Bind Request Bind Response Server Cluster On/Off

10 Application Framework -Environment for hosting manufacturer-defined application objects on Zigbee devices -Application object represents different application types that can be present on a single Zigbee node. For example, a switch that controls a light or a light. -Up to 240 distinct application objects can be defined, each interfacing on an endpoint indexed from 1 to Endpoints (8bit-field) address specific application objects on a single Zigbee Device

11 Application Framework: Cluster Devices - Implement server and client sides of the interface respectively. For example, a light and a light switch are devices. Attribute - A data entity which represents a physical quantity or state. This data is communicated to other devices using commands. Cluster - A collection of attributes and commands, which together define a communication interface between two devices.

12 Application Framework: Cluster A client/server model is used to define a cluster. ZigBee Node Server Device ServerCluster ServerCluster Client Device Client Cluster Client Cluster Cluster Binding ZigBee Node Client Device Client Cluster Client Cluster Server Device ServerCluster ServerCluster The devices implement server and client sides of the interface respectively. The server entity stores the attributes of the cluster and the client entity affects or manipulates those attributes by sending commands to the server entity.

13 Application Framework: Commands Query-Based APP From Client to Server From Server to Client Event-Driven APP From Server to Client

14 Application Framework: General Clusters

15 An Example Node 1 Node 2 Client Device On/Off Switch Device Server Device On/Off Light Device Client Cluster On/Off Cluster Binding Server Cluster On/Off....

16 An Example

17 Application Framework: Profiles Application profiles are agreements for messages, message formats, and processing actions that enable developers to create an application employing application entities that reside on separate devices. These application profiles enable applications to send commands, request data, and process commands and requests. ZigBee Cluster Library (ZCL) ZigBee Application Profiles General Closures HVAC Home Automation SmartEnergy... Lighting Measurements...

18 Application Framework: HA Profile Home Automation Profile offers an affordable, reliable, expandable and easy way to control the environment, lighting, safety, and security in homes or small offices.

19 VAC Closures Lighting General Wireless Sensor Networks Application Framework: HA Profile Home Automation Profile offers an affordable, reliable, expandable and easy way to control the environment, lighting, safety, and security in homes or small offices. Device Server Client Description On/Off Switch X Device able of sending on/off commands to the devices to switch them on/off. Level Control X Device that controls, e.g., the level of brightness of a light. Switch On/Off Output X The device that can be switched on/off. Level Controllable Output X The device can adjusted its characteristics. On/Off Light X The light device that can be switched on/off. Dimmable Light X The light device whose luminance level may be controlled. Color Dimmable X The light device whose luminance, hue, and saturation levels may be controlled. Light On/Off Light X The switch that can send on, off and toggle commands to the lights. Switch Dimmer Switch X The switch that can control the level of a characteristic of a device, typically the brightness of a light. Color Dimmer X The switch that can control the luminance, hue and saturation levels of a multicolor Switch light. Shade X Device that provides the ability to open or close window. Shade Controller X The device that can control the level of a shade, and put it into configuration mode so that the user may adjust its limits. Heating/Cooling Unit X The unit that can heat or cool a space in a house. Thermostat X The device that sends heating and/or cooling requirement notifications to a heating/cooling unit. Temperature X The device that reports temperature measurements. Sensor Pump X Pump that may have variable speed. Typically used for pumping water. Pump Controller X The device that can configure and control a Pump device. Pressure Sensor X The sensor that measures the pressure of a liquid, typically water.

20 Zigbee Profiles ZigBee Home Automation ZigBee Telecom Services ZigBee Building Automation ZigBee 3D Sync ZigBee Smart Energy ZigBee Remote Control ZigBee Health Care ZigBee Input Device ZigBee Retail Services

21 Wireless Sensor Networks

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