chapter6 3 communication(zigbee)

5/23/2018 Chapter6 3 Communication(ZigBee)

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Robotics experiment 1

Dept. of Robot Engineering

Yeungnam Univ.

6. Communication

1. Introduction

2.Mechanical Design

3. Electronic Design

4. Sensor Control

5. Motor Control

6. Communication

7. Navigation

8. SLAM

9. Multi robots

6.1 Introduction

6.2 Bluetooth

6.3 ZigBee

6.4 WiFi

How to build a mobile robot

ZigBee


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Yeungnam Univ.

6. Communication

6.3 Zigbee

What is ZigBee?Technological Standard Created for Controland Sensor Networks

Based on the I EEE 802.15.4 Standard

Created by the ZigBee Alliance

The ZigBee Name

Named for erratic, zig-zagging patterns of bees between flowers

Symbolizes communication between nodes in a mesh network

Network components analogous to queen bee, drones, worker bees


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Yeungnam Univ.

6. Communication

Actual training

Model (H-Mote)

Specifications

CUP is 8MHz TI MSP430 controller

Radio Transceiver is CC2420 chip(2.4GHz) /

data transmission rate is maximum 250kbits/sec.Interface is USB thus, data transmission is quite fast and easy.

Sensor board has light, temp, mic, ultrasonic thus it is easy to connect to

MSP430/ADC(0~7)


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6. Communication

ZigBee:a general-purpose, inexpensive, self-organizing, mesh networkthat

can be used for industrial control, embedded sensing, medical datacollection, smoke and intruder warning, building automation, home

automation, etc.

a protocols which is intended for use in embedded applications

requiring low data rates and low power consumption.


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Yeungnam Univ.

6. Communication

The ZigBee Alliance is an association of companies working together to

enable reliable, cost-effective, low-power, wirelessly networked, monitoring

and control products based on an open global standard.

It is a suite of high level communication protocols using small, low-

power digital radios based on the IEEE 802.15.4 standard for wireless

personal area networks (WPANs).

It is targeted at RF applications that require a low data rate, long battery life,

and secure networking,and intended to be simpler and cheaper than other

WPANs such as Bluetooth.

It operates in the industrial, scientific and medical (ISM) radio bands; 868

MHz in Europe, 915 MHz in the USA and 2.4 GHz in most jurisdictions

worldwide.


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6. Communication

Introduction

The IEEE 802.15.4 standard was completed in May 2003. The ZigBee specifications were ratified on 14 December 2004.

The ZigBee Alliance announced public availability of Specification 1.0on 13 June 2005.

Much research is still going on with ZigBee.

ZigBee Product Companies Helicomm

MaxStream

Luxoft Labs

Crossbow Technology

Innovative Wireless Technologies


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6. Communication

Why ZigBee ?

#1 - Low Cost

Allows addition of wireless to any price product

#2 - Ease of Deployment

Mesh networking overcomes line-of-sight fears

#3 - Multi-source Products

Not betting on a single company

#4 - Battery Operation

Allows products to be un-tethered from power cords

#5 Large network orders (< 65 k nodes)


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6. Communication

ZigBee Network Configuration (Source: http://www.embedded.com/)

How ZigBee Works

Topology

Star Cluster Tree

Mesh

Network coordinator, routers, end devices


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Yeungnam Univ.

6. Communication

The concept of the ZigBee network topology

Topologies are supported by ZigBee: star , mesh, and cluster tree.

Star topology is most useful when several end devices are located

close together so that they can communicate with a single router

node. That node can then be a part of a larger mesh network that

ultimately communicates with the network coordinator.

Mesh networking allows for redundancy in node links, so that if

one node goes down, devices can find an alternative path to

communicate with one another.


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6. Communication

How zigbee works?

ZigBee basically uses digital radios to allow devices to communicate

with one another. A typical ZigBee network consists of several types of devices.

A network coordinator is a device that sets up the network, is

aware of all the nodes within its network, and manages both the

information about each node as well as the information that is being

transmitted/received within the network. Every ZigBee networkmust contain a network coordinator.

Ful l F unction Devices (FFD' s) support all of the 802.15.4

functions. They can serve as network coordinators, network

routers, or as devices that interact with the physical world.

The Reduced Function Device (RFD), which usually only serve as

devices that interact with the physical world.


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Yeungnam Univ.

6. Communication

the software

Network, Security &

Application layers

Brand management

IEEE 802.15.4

the hardware

Physical & Media

Access Control layers

IEEE 802.15.4 & ZigBee In Context

PHY868MHz / 915MHz / 2.4GHz

MAC

NetworkStar / Mesh / Cluster-Tree

Security32- / 64- / 128-bit encryption

Application

API

ZigBee

Alliance

IEEE

802.15.4

Customer

Silicon Stack App

Source: http://www.zigbee.org/resources/documents/IWAS_presentation_Mar04_Designing_with_802154_and_zigbee.ppt


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6. Communication

The 802 Wireless Space

Source: http://www.zigbee.org/en/resources/


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6. Communication

Wireless communication technology


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6. Communication

ZigBee is a home-area network designed specifically to

replace the proliferation of individual remote controls. ZigBeewas created to satisfy the market's need for a cost-effective,

standards-based wireless network that supports low data rates,

low power consumption, security, and reliability.

How ZigBee Works States of operation

Active

Sleep

Devices

Full Function Devices (FFDs)

Reduced Function Devices (RFDs)

Modes of operation

Beacon

Non-beacon


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Yeungnam Univ.

6. Communication

Wireless technology comparison chart

Market NameStandard

ZigBeeTM

802.15.4Wi-Fi

TM

802.11b

BluetoothTM

802.15.1

Bandwidth 250kbps Up to 54Mbps 1Mbps

Battery life(days) 101,000 0.5 - 5 1 - 7

Network size unlimited 32 7

StrongholdLong batterylife, low cost,

reliability

High data rate.

flexibility

Cost ,

convenience

Transmission

range(meters)1-100 1-100 1-10

ApplicationFocus

Monitoring andControl

Web, Email,video

CableReplacement

Source: http://www.eetimes.com/design/embedded/4006430/Home-networking-with-Zigbee


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6. Communication

What Does ZigBee Do?

Designed for wireless controls and sensors

Operates in Personal Area Networks (PANs) and device-to-devicenetworks

Connectivity between small packet devices

Control of lights, switches, thermostats, appliances, etc.

Example of ZigBee home automation


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6. Communication

Wireless Sensor (and Actuator) Networks


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6. Communication

Lights and Switches

Source: ZigBee Specification Document

Zigbee sensor


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Yeungnam Univ.

6. Communication

Slide Courtesy of

ZigBee Mesh Networking

Source: http://www.zigbee.org/en/resources/#SlidePresentations


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6. Communication

Slide Courtesy of




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6. Communication

Slide Courtesy of




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6. Communication

Slide Courtesy of




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6. Communication

Slide Courtesy of




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6. Communication

Academic Research

Research in ZigBee is being conducted in different fields:

Wireless and sensor networks

Wireless communications

Neuroengineering

ZigBee Products

Development Kits

Sensors

Transceivers

Modules


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Yeungnam Univ.

6. Communication

Current ZigBee Uses

Environmental Monitoring Agricultural Monitoring

Home Automation Still on Horizon

Product Applications Road map products-tracking

Consumer electronics

PC

Personal and healthcare

Commercial and residential control


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6. Communication

Source: http://jobscochin.com

Operation of ZigBee:

operate in the 2.4GHz band or the 868MHz and 915MHz ISM

(industrial, scientific and medical) bands used in Europe and the US

respectively. Data rate: 250kbps at 2.4GHz (compared to Bluetooth's

1Mbps) and 20-40kbps in the lower frequency bands.


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Yeungnam Univ.

6. Communication

ZigBee is the most popular industry wireless mesh networking standard for

connecting sensors, instrumentation and control systems.

is an industry standard supported by multiple solution providers.

ZigBee solutions:

relatively inexpensive because several suppliers have already

implemented ZigBee-based ICs and modules in anticipation of high

volumes for a standard solution.

offer users independence from any one supplier because onecompanys ZigBee networking solution can be substituted for

anothers.

In theory, a ZigBee application deployed in a location can use other

existing ZigBee nodes in that location to extend its range and improve

its communication reliability. delivers solid wireless connectivity for sensors and actuators in

applications that can need the general benefits of mesh networking (i.e.,

coverage and reliability) at a reasonable price and tolerate ZigBees

limitations in mesh size, power consumption, node-to-node range, and

master-oriented operation.

R b i i 1


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Yeungnam Univ.

6. Communication

ZigBee operates in two main modes: non-beacon mode and

beacon mode.

Beacon mode is a fully coordinated mode in that all the device knowwhen to coordinate with one another. In this mode, the network

coordinator will periodically "wake-up" and send out a beacon to the

devices within its network. This beacon subsequently wakes up each

device, who must determine if it has any message to receive. If not, the

device returns to sleep, as will the network coordinator, once its job iscomplete.

Non-beacon modeis less coordinated, as any device can communicate

with the coordinator at will. However, this operation can cause

different devices within the network to interfere with one another, and

the coordinator must always be awake to listen for signals, thusrequiring more power.

In any case, ZigBee obtains its overall low power consumption because

the majority of network devices are able to remain inactive over long

periods of time.

R b ti i t 1


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Yeungnam Univ.

6. Communication

A comparison between ZigBee and bluetooth

Protocol

ZigBeeuses basic master-slave configuration suited to static star networks

of many infrequently used devices that talk via small data packets.

This aspect suits ZigBee to building automation and the control of

multiple lights, security sensors and so on.

Bluetoothis more complex because it's geared towards handling voice,

images and file transfers in ad hoc networks. Bluetooth devices can

work peer-to-peer and support scatternets of multiple smaller non-

synchronized networks (piconets). The protocol, however, only

allows up to eight slave nodes in a basic master-slave piconet set-up.

R b ti i t 1


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Yeungnam Univ.

6. Communication

The main features of zigbee:

Dual PHY (2.4GHz and 868/915 MHz)

Data rates of 250 kbps (@2.4 GHz), 40 kbps (@ 915 MHz), and 20 kbps(@868 MHz)

Optimized for low duty-cycle applications (


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Yeungnam Univ.

6. Communication

Characteristics of ZigBeeLow data rate

A higher data rate is not always better, depending on the requirements of

the application. For a given transmitter power, higher data rate can be

achieved by sacrificing range or range can be increased by using a lower

radio channel data rate

Low latency

When a ZigBee device is powered down, it can wake up and get a packet

across a network connection in around 15 milliseconds. A Bluetooth devicein a similar state would take around three seconds to wake up and respond.

A sensor in an industrial plant needs to get its messages through in

milliseconds.

Low power consumption

ZigBeesreliance on a central mains-powered controller minimizes the

power consumption of the nodes.They will only need to turn on when they want to transfer data.

There is a beacon scheme that the master uses to define slots. The nodes

can then wake up, listen, synchronize to a slot and send data back. It

reduces the time that the outlying nodes need to be on for.

Robotics e periment 1


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6. Communication



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6. Communication

Wireless network technology

Range

PeakDataRate

Closer Farther

Slower

Faster

UWBWireless Data

Applications

Sources: WRH + Co

Wireless Video

Applications

IrDA

802.11g

802.11b

802.11a

2.5G/3G

Bluetooth

ZigBee

Wireless

Sensors

Wireless

Networking

Wi-Fi



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6. Communication

ZigBee application



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6. Communication

ZigBee application



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Dept of Robot Engineering

6. Communication

References[1] http://www.ZigBee.org

[2] Designing with 802.15.4 and ZigBee, Presentation Slides, available on

ZigBee.org

[3] ZigBee Tutorial, http://www.tutorial-reports.com/wireless/zigbee

[4] IEEE 802.15.4 Specification

[5] Network Layer Overview, Presentation Slides, Ian Marsden, Embedded Systems

Show, Birmingham, October 12th, 2006,

064513r00ZB_MG_Network_Layer_Overview.pdf, available on ZigBee.org[6] Designing a ZigBeeNetwork, Presentation Slides, David Egan, Ember

Corporation, ESS 2006, Birmingham, 064516r00ZG_MG_Network_Design.pdf,

available on ZigBee.org

[7] ZigBee Architecture Overview, Presentation Slides, Oslo, Norway June 2005,

ZigBee_Architecture_and_Specifications_Overview.pdf, available on ZigBee.org

[8] Low Power Consumption Features of the IEEE 802.15.4/ZigBee LR-WPAN

Standard, http://www.cens.ucla.edu/sensys03/sensys03-callaway.pdf

[9] ZigBee Home Automation Mobile from Pantech,

http://www.i4u.com/article2561.html

chapter6 3 communication(zigbee)

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