Zigbee Wireless Control That Simply Works

8/8/2019 Zigbee Wireless Control That Simply Works

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ZIGBEE (“WIRELESS CONTROL THAT SIMPLY

WORKS”)

1. ABSTRACT:

Today most wireless industries focus on high data throughput, simple wireless

connectivity, relaxed throughput, very low power and an inexpensive device. On the telecom

front, numerous wireless technologies have been introduced in the country such as Wi-Fi,

Wimax, Bluetooth,etc. Bluetooth is not the end of world. The engineers across the globe are

working on solutions that can be customized according to user's needs. ZIGBEE is one such

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solution.Zigbee is the dominant technology among all other wireless devices because of its low

cost, low power consumption, small size, fast and easy deployment.

This presentation involves the detail explanation about what is Zigbee, why we need it,

how it works, advantages they offer and their limitations. Also explained are some of the possible that can make possible with it.

Zigbee is designed to provide highly efficient connectivity between small packet

devices.Zigbee’s current focus is to define a general-purpose,inexpensive,self organizing mesh

network that can be used for embedded sensing, medical data collection and home

automation,etc.This keeps Zigbee far ahead from the existing technologies like Wi-Fi,Wimax

and Bluetooth,etc.

This paper will outline Zigbee principles with a clear depiction.Additionally the comparision of

Zigbee with other wireless devices is also mentioned. A greater emphasis is laid on

highlighting the credibility’s of Zigbee network mechanism

2. INTRODUCTION:

Zigbee is a rather new wireless technology that looks to have applications in a variety of

fields. Zigbee is a technological standard based on the IEEE 802.15.4 specification for low

data rates in the Industrial, Scientific, and Medical (ISM) radio bands. The technology allows

for devices to communicate with one another with very low power consumption, allowing the

devices to run on simple batteries for several years. Zigbee is targeting various forms of

automation, as the low data rate communication is ideal for sensors, monitors, and the like.

The name "ZigBee" is derived from the erratic zigging patterns many bees make between

Flowers when collecting pollen. This is evocative of the invisible webs of connections existing

in a fully wireless environment.

3. WHAT IS ZIGBEE?

ZigBee is a technological standard, based on the IEEE 802.15.4 standard, which was created

specifically for control and sensor networks. In the Institute of Electrical and Electronics

Engineers (IEEE), the 802 group is the section that deals with network operations and



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technologies. Group 15 works more specifically with wireless networking, and Task Group 4

drafted the 802.15.4 standard for a low data rate wireless personal area network (WPAN).

Figure 1 ZigBee Stack Architecture

As can be seen in the figure, IEEE 802.15.4 defined MAC Layer and Physical (PHY) Layer

address such things as the frequency and data rate specifications. ZigBee, meanwhile,

develops the Network Layer and Application Layer, which includes the Applications Support

Sub layer, the ZigBee Device Object, and the Security Services. The Network Layer and

Application Layer are more specific than the IEEE layers and involves such things as how a

ZigBee network is to be set up, how the devices in the network relate to one another, and so

on.

4. WHY DO WE NEED ZIGBEE?

Zigbee is the only wireless standards-based technology: it has many advantages like



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• Supports large network orders

• Low to no QOS guarantees

• Flexible protocol design suitable for many applications

• Simple frame structure

• Battery life extensions

• That addresses the unique needs of remote monitoring and sensory network

applications.

• Enables broad based deployment of wireless networks with low cost.

• Provides long life batteries.

• Facilitates ease-of-use and advanced support for larger networks.

Figure 2: Comparision of Zigbee with other devices:



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5. ZIGBEE ARCHITECTURE: There are three different types of Zigbee devices:

5.1.ZigBee coordinator(ZC): The most capable device, the coordinator forms the root of the

network tree and might bridge to other networks. There is exactly one ZigBee coordinator in

each network since it is the device that started the network originally. It is able to store

information about the network, including acting as the Trust Centre & repository for security

keys.

5.2.ZigBee Router (ZR): As well as running an application function a router can act as anintermediate router, passing data from other devices.

5.3ZigBee End Device (ZED): Contains just enough functionality to talk to the parent node

(either the coordinator or a router); it cannot relay data from other devices. This relationship

allows the node to be asleep a significant amount of the time thereby giving long battery life. A



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ZED requires the least amount of memory, and therefore can be less expensive to manufacture

than a ZR or ZC

6.HOW ZIGBEE WORKS?

ZigBee basically uses digital radios to allow devices to communicate with one another. Every

ZigBee network must contain a network coordinator. Other Full Function Devices (FFD' s)

may be found in the network, and these devices 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 final device found in these networks is the Reduced Function Device (RFD), which

usually only serve as devices that interact with the physical world.

Figure 3:An example of ZigBee Network

The figure above introduces the concept of the ZigBee network topology. Several topologies

are supported by ZigBee, including star, mesh, and cluster tree. Star and mesh networking are

both shown in the figure above. As can be seen, 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 thenetwork 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.

An example of mesh networking with multiple paths:



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Figure 4: Mesh Networking Path [1]

Figure 5: Mesh Networking Path [2]

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

network coordinator will periodically "wake-up”. On the other hand, the non beacon mode the

coordinator must always be awake to listen for signals, thus requiring 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.

7.ZIGBEE APPLICATIONS:



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• Home Entertainment and Control — Smart lighting, advanced temperature control,

safety and security, movies and music

• Home Awareness — Water sensors, power sensors, smoke and fire detectors, smart

appliances and access sensors• Mobile Services — m-payment, m-monitoring and control, m-security and access

control, m-healthcare and tele-assist

• Commercial Building — Energy monitoring, HVAC, lighting, access control



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Figure6.ZigBeeApplication.

ZigBee is designed for wireless controls and sensors. It could be built into just about anything

you have around your home or office, including lights, switches, doors and appliances. These

devices can then interact without wires, and you can control them all . . . from a remote control

or even your mobile phone. It allows wireless two-way communications between lights and

switches, thermostats and furnaces, hotel-room air-conditioners and the front desk, and central

command posts. It travels across greater distances and handles many sensors that can be linked

to perform different tasks.

9.ZIGBEE vs. BLUETOOTH:

ZigBee is broadly categorized as a low rate WPAN, and its closest technology is Bluetooth. A

good bit of energy has been spent in analyzing whether ZigBee and Bluetooth are

complementary or competing technologies, but after a quick look at the two, it can be seen that

they fall a lot farther down the complementary side of the spectrum. ZigBee networks can

support a larger number of devices and a longer range between devices than Bluetooth.

Because of these differences, the technologies are not only geared toward different

applications, they don't have the capability to extend out to other applications.

Zigbee:

• Very low duty cycle, very long primary battery life

• ZigBee uses low data rate, low power consumption, and works with small packet

devices;

• ZigBee is focused on control ,automation and sensor networks

Bluetooth:

• Moderate duty cycle, secondary battery lasts same as master

• Bluetooth uses a higher data rate, higher power consumption, and works with large

packet devices.



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Zigbee Wireless Control That Simply Works