ZigBee Technology : Architecture, Working and Its Applications

In this present communication world, there are numerous high data rate communication standards that are available, but none of these meet the sensors’ and control devices’ communication standards. These high-data-rate communication standards require low-latency and low-energy consumption even at lower bandwidths. The available proprietary wireless systems’ Zigbee technology is low-cost and low-power consumption and its excellent and superb characteristics make this communication best suited for several embedded applications, industrial control, and home automation, and so on. The Zigbee technology range for transmission distances mainly ranges from 10 – 100 meters based on the output of power as well as environmental characteristics.

What is Zigbee Technology?

Zigbee communication is specially built for control and sensor networks on IEEE 802.15.4 standard for wireless personal area networks (WPANs), and it is the product from Zigbee alliance. This communication standard defines physical and Media Access Control (MAC) layers to handle many devices at low-data rates. These Zigbee’s WPANs operate at 868 MHz, 902-928MHz, and 2.4 GHz frequencies. The data rate of 250 kbps is best suited for periodic as well as intermediate two-way transmission of data between sensors and controllers.

Zigbee is a low-cost and low-powered mesh network widely deployed for controlling and monitoring applications where it covers 10-100 meters within the range. This communication system is less expensive and simpler than the other proprietary short-range wireless sensor networks as Bluetooth and Wi-Fi.

Zigbee supports different network configurations for the master to master or master to slave communications. And also, it can be operated in different modes as a result the battery power is conserved. Zigbee networks are extendable with the use of routers and allow many nodes to interconnect with each other for building a wider area network.

History of Zigbee Technology

In the year 1990, the digital radio networks with self-organizing ad hoc were implemented. The Zigbee specification like IEEE 802.15.4-2003 was approved in the year 2004, on December 14. The Specification 1.0 was announced by Zigbee Alliance in the year 2005, on June 13, called the Specification of ZigBee 2004.

Cluster Library

In the year 2006, September, the Specification of Zigbee 2006 was announced by replacing the 2004 stack. So this specification mainly replaces the pair structure of key-value as well as message utilized within the 2004 stack through a cluster library.

A library includes a set of consistent commands, planned beneath groups called clusters with names like Home Automation, Smart Energy & Light Link of ZigBee. In the year 2017, the library was renamed with Dotdot by Zigbee Alliance and announced as a new protocol. So, this Dotdot has worked for approximately all Zigbee devices as the default application layer.

Zigbee Pro

In the year 2007, Zigbee Pro like Zigbee 2007 was finalized. It is one kind of device which operates on a legacy Zigbee network. Because of the disparities within the options of routing, these devices should turn into non-routing ZEDs or Zigbee end devices (ZEDs) on a legacy Zigbee network. The legacy Zigbee devices have to turn into Zigbee end devices on a network of Zigbee Pro. It functions through the 2.4 GHz ISM band as well as includes a sub-GHz band.

How does Zigbee Technology Work?

Zigbee technology works with digital radios by allowing different devices to converse through one another. The devices used in this network are a router, coordinator as well as end devices. The main function of these devices is to deliver the instructions and messages from the coordinator to the single end devices such as a light bulb.

In this network, the coordinator is the most essential device which is placed at the origin of the system. For each network, there is simply one coordinator, used to perform different tasks. They choose a suitable channel to scan a channel as well as to find the most appropriate one through the minimum of interference, allocate an exclusive ID as well as an address to every device within the network so that messages otherwise instructions can be transferred in the network.

Routers are arranged among the coordinator as well as end devices which are accountable for messages routing among the various nodes. Routers get messages from the coordinator and stored them until their end devices are in a situation to get them. These can also permit other end devices as well as routers to connect the network;

In this network, the small information can be controlled by end devices by communicating with the parent node like a router or the coordinator based on the Zigbee network type. End devices don’t converse directly through each other. First, all traffic can be routed toward the parent node like the router, which holds this data until the device’s receiving end is in a situation to get it through being aware. End devices are used to request any messages that are waiting from the parent.

Zigbee Architecture

Zigbee system structure consists of three different types of devices as Zigbee Coordinator, Router, and End device. Every Zigbee network must consist of at least one coordinator which acts as a root and bridge of the network. The coordinator is responsible for handling and storing the information while performing receiving and transmitting data operations.

Zigbee routers act as intermediary devices that permit data to pass to and fro through them to other devices. End devices have limited functionality to communicate with the parent nodes such that the battery power is saved as shown in the figure. The number of routers, coordinators, and end devices depends on the type of networks such as star, tree, and mesh networks.

Zigbee protocol architecture consists of a stack of various layers where IEEE 802.15.4 is defined by physical and MAC layers while this protocol is completed by accumulating Zigbee’s own network and application layers.

Physical Layer: This layer does modulation and demodulation operations upon transmitting and receiving signals respectively. This layer’s frequency, data rate, and a number of channels are given below.

MAC Layer: This layer is responsible for reliable transmission of data by accessing different networks with the carrier sense multiple access collision avoidances (CSMA). This also transmits the beacon frames for synchronizing communication.

Network Layer: This layer takes care of all network-related operations such as network setup, end device connection, and disconnection to network, routing, device configurations, etc.

Application Support Sub-Layer: This layer enables the services necessary for Zigbee device objects and application objects to interface with the network layers for data managing services. This layer is responsible for matching two devices according to their services and needs.

Application Framework: It provides two types of data services as key-value pair and generic message services. The generic message is a developer-defined structure, whereas the key-value pair is used for getting attributes within the application objects. ZDO provides an interface between application objects and the APS layer in Zigbee devices. It is responsible for detecting, initiating, and binding other devices to the network.

Zigbee Operating Modes and Its Topologies

Zigbee two-way data is transferred in two modes: Non-beacon mode and Beacon mode. In a beacon mode, the coordinators and routers continuously monitor the active state of incoming data hence more power is consumed. In this mode, the routers and coordinators do not sleep because at any time any node can wake up and communicate.

However, it requires more power supply and its overall power consumption is low because most of the devices are in an inactive state for over long periods in the network. In a beacon mode, when there is no data communication from end devices, then the routers and coordinators enter into a sleep state. Periodically this coordinator wakes up and transmits the beacons to the routers in the network.

These beacon networks are work for time slots which means, they operate when the communication needed results in lower duty cycles and longer battery usage. These beacon and non-beacon modes of Zigbee can manage periodic (sensors data), intermittent (Light switches), and repetitive data types.

Zigbee Topologies

Zigbee supports several network topologies; however, the most commonly used configurations are star, mesh, and cluster tree topologies. Any topology consists of one or more coordinators. In a star topology, the network consists of one coordinator which is responsible for initiating and managing the devices over the network. All other devices are called end devices that directly communicate with the coordinator.

This is used in industries where all the endpoint devices are needed to communicate with the central controller, and this topology is simple and easy to deploy. In mesh and tree topologies, the Zigbee network is extended with several routers where the coordinator is responsible for staring them. These structures allow any device to communicate with any other adjacent node for providing redundancy to the data.

If any node fails, the information is routed automatically to other devices by these topologies. As redundancy is the main factor in industries, hence mesh topology is mostly used. In a cluster-tree network, each cluster consists of a coordinator with leaf nodes, and these coordinators are connected to the parent coordinator which initiates the entire network.

Due to the advantages of Zigbee technology like low cost and low power operating modes and its topologies, this short-range communication technology is best suited for several applications compared to other proprietary communications, such as Bluetooth, Wi-Fi, etc. some of these comparisons such as range of Zigbee, standards, etc., are given below.

Why Low Data Rates in Zigbee?

We know that different types of wireless technologies are available in the market such as Bluetooth as well as WiFi which provides high speed of data. But, the data rates in Zigbee are less because the main purpose behind the ZigBee development is to utilize it in wireless control as well as monitor.

The amount of data, as well as the frequency of communication used in such applications, is extremely low. Although, it is probable for a network like IEEE 802.15.4 to attain high data rates, so the Zigbee technology is based on the network IEEE 802.15.4.

Zigbee Technology in IoT

We know that Zigbee is one kind of communication technology similar to Bluetooth as well as WiFi, however, there are also numerous new rising networking alternatives like Thread which is an option for the applications of home automation. In major cities, the Whitespace technologies were implemented for IoT-based wider region use cases.

ZigBee is a low-power WLAN (wireless local area network) specification. It provides fewer data using less power by frequently connected devices to turn off a battery. Due to this, the open standard has been connected through M2M (machine-to-machine) communication as well as the industrial IoT (internet of things).

Zigbee has become an IoT protocol that is accepted globally. It is already competing with Bluetooth, WiFi, and Thread.

Zigbee Devices

The specification of IEEE 802.15.4 Zigbee mainly includes two devices like Full-Function Devices (FFD) as well as Reduced-Function Devices (RFD). An FFD Device performs different tasks which are explained within the specification & it can adopt any task within the network.

An RFD Device has partial capabilities so it performs limited tasks and this device can converse with any device within the network. It must act as well as pay attention within the network. An RFD device can converse simply with an FFD Device & it is used in simple applications such as controlling a switch by activating and deactivating it.

In an IEEE 802.15.4 n/w, the Zigbee devices play three different roles like Coordinator, PAN Coordinator & Device. Here, FFD devices are Coordinator as well as PAN Coordinator whereas the Device is either an RFD/ FFD Device.

The main function of a coordinator is for relaying messages. In a personal area network, a PAN controller is an essential controller and a device is known as if the device is not a coordinator.
The ZigBee standard can create three protocol devices depending on the Zigbee devices, PAN coordinator, coordinator, and the standard specification of ZigBee like the coordinator, router, and end device which are discussed below.

Zigbee Coordinator

In an FFD device, it is a PAN Coordinator is used to form the network. Once the network is established, then it assigns the address of the network for the devices used within the network. And also, it routes the messages among the end devices.

Zigbee Router

A Zigbee Router is an FFD Device that allows the range of the Zigbee Network. This Router is used to add more devices to the network. Sometimes, it acts as a Zigbee End Device.

Zigbee End Device

This is neither a Router nor a Coordinator that interfaces to a sensor physically otherwise performs a control operation. Based on the application, it can be either an RFD or an FFD.

Why ZigBee is better than WiFi?

In Zigbee, the data transfer speed is less as compared with WiFi, so it’s the highest speed is simply 250kbps. It is very less as compared with the less speed of WiFi.

One more best quality of Zigbee is the rate of power utilization as well as the life of the battery. Its protocol lasts for several months because once it is assembled then we can forget.

What Devices use ZigBee?

The following list of devices supports the ZigBee protocol.

• Belkin WeMo
• Samsung SmartThings
• Yale smart locks
• Philips Hue
• Thermostats from Honeywell
• Ikea Tradfri
• Security Systems from Bosch
• Comcast Xfinity Box from Samsung
• Hive Active Heating & accessories
• Amazon Echo Plus
• Amazon Echo Show

Instead of connecting every Zigbee device separately, a central hub is required for controlling all the devices. The above-mentioned devices namely SmartThings as well as Amazon Echo Plus can also be used like a Wink hub to play a vital role within the network. The central hub will scan the network for all the supported devices and provides you simple control of the above devices with a central app.

What is the difference between ZigBee and Bluetooth?

The difference between Zigbee and Bluetooth is discussed below.

Bluetooth

Zigbee

The frequency range of Bluetooth ranges from 2.4 GHz – 2.483 GHz
The frequency range of Zigbee is 2.4 GHz

It has 79 RF channels
It has 16 RF channels

The modulation technique used in Bluetooth is GFSK
Zigbee uses different modulation techniques like BPSK, QPSK & GFSK.

Bluetooth includes 8-cell nodes
Zigbee includes above 6500 cell nodes

Bluetooth uses IEEE 802.15.1 specification
Zigbee uses IEEE 802.15.4 specification

Bluetooth covers the radio signal upto 10meters
Zigbee covers the radio signal upto 100 meters

Bluetooth takes 3 seconds to join a network
Zigbee takes 3 Seconds to join a network

The network range of Bluetooth ranges from 1-100 meters based on radio class.

The network range of Zigbee is up to 70 meters

The protocol stack size of a Bluetooth is 250 Kbytes
The protocol stack size of a Zigbee is 28 Kbytes

The height of the TX antenna  is 6meters whereas the RX antenna is 1meter
The height of the TX antenna  is 6meters whereas the RX antenna is 1meter

Blue tooth uses rechargeable batteries

Zigbee doesn’t use rechargeable batteries

Bluetooth requires less bandwidth
As compared with Bluetooth, it needs high bandwidth

The TX Power of Bluetooth is 4 dBm

The TX Power of Zigbee  is 18 dBm

The frequency of Bluetooth is 2400 MHz
The frequency of Zigbee is 2400 MHz

Tx antenna gain of Bluetooth is 0dB whereas the RX -6dB
Tx antenna gain of Zigbee is 0dB whereas the RX -6dB

Sensitivity is -93 dB
Sensitivity is -102 dB

The margin of Bluetooth is 20 dB
Margin of zigbee is 20 dB

Bluetooth range is 77 meters
The Zigbee range is 291 meters

What is the difference between LoRa and ZigBee?

The main difference between LoRa and Zigbee are discussed below.

LoRa
Zigbee

The frequency bands of LoRa ranges from 863-870 MHz, 902-928 MHz &779-787 MHz
The frequency bands of Zigbee are 868MHz, 915 MHz, 2450 MHz

LoRa covers the distance in urban areas like 2 to 5kms whereas in rural areas 15kms
Zigbee covers the distance from 10-100meters

The power utilization of LoRa is low as compared to Zigbee
Power utilization is low

The modulation technique used in LoRa is FSK otherwise GFSK
The modulation technique used in Zigbee is OQPSK & BPSK, It uses the DSSS method to change bits to chips.

The data rate of LoRa is 0.3 to 22 Kbps for LoRa modulation  & 100 Kbps for GFSK
The data rate of Zigbee is 20 kbps for 868 frequency band, 40Kbps for 915 frequency band, and  250 kbps for 2450 frequency band)

The network architecture of LoRa includes servers, LoRa Gateway & end devices.
The network architecture of Zigbee routers, coordinator & end devices.

The protocol stack of LoRa includes PHY, RF, MAC & application layers
The protocol stack of Zigbee includes PHY, RF, MAC, network security & application layers.

The Physical Layer of LoRa mainly uses a modulation system & includes error rectification abilities. It includes a preamble for the purpose of synchronization & uses an entire frame CRC & PHY header CRC.
Zigbee includes two physical layers like 868/915 Mhz & 2450 MHz.

LoRa is used as a WAN (Wide Area Network)
Zigbee is used like LR-WPAN (low rate wireless personal area network)

It uses IEEE 802.15.4g standard & Alliance is LoRa
Zigbee uses IEEE 802.15.4 specification and Zigbee Alliance

Zigbee Technology Advantages and Disadvantages

The advantages of Zigbee include the following.

• This network has a flexible network structure
• Battery life is good.
• Power consumption is less
• Very simple to fix.
• It supports approximately 6500 nodes.
• Less cost.
• It is self-healing as well as more reliable.
• Network setting is very easy as well as simple.
• Loads are evenly distributed across the network because it doesn’t include a central controller
• Home appliances monitoring as well controlling is extremely simple using remote
• The network is scalable and it is easy to add/remote ZigBee end device to the network.

The disadvantages of Zigbee include the following.

• It needs the system information to control Zigbee based devices for the owner.
• As compared with WiFi, it is not secure.
• The high replacement cost once any issue happens within Zigbee based home appliances
• The transmission rate of the Zigbee is less
• It does not include several end devices.
• It is so highly risky to be used for official private information.
• It is not used as an outdoor wireless communication system because it has less coverage limit.
• Similar to other types of wireless systems, this ZigBee communication system is prone to bother from unauthorized people.

Applications of Zigbee Technology

The applications of ZigBee technology include the following.

Industrial Automation: In manufacturing and production industries, a communication link continually monitors various parameters and critical equipment. Hence Zigbee considerably reduces this communication cost as well as optimizes the control process for greater reliability.

Home Automation: Zigbee is perfectly suited for controlling home appliances remotely as a lighting system control, appliance control, heating, and cooling system control, safety equipment operations and control, surveillance, and so on.

Smart Metering: Zigbee remote operations in smart metering include energy consumption response, pricing support, security over power theft, etc.

Smart Grid monitoring: Zigbee operations in this smart grid involve remote temperature monitoring, fault locating, reactive power management, and so on.

ZigBee technology is used to build engineering projects like wireless fingerprint attendance system and home automation.

This is all about a brief description of Zigbee technology’s architecture, operations modes, configurations, and applications. We hope that we have given you enough content on this title, for you to understand it better. Thus, this is all about an overview of Zigbee technology and it is based on IEEE 802.15.4 network. The designing of this technology can be done extremely strong so it operates in all kinds of environments.

It provides flexibility as well as security for different environments. Zigbee technology has gained so much popularity in the market because it provides consistent mesh networking by enabling a network to control over an extensive region, and also it provides low-power communications. So this is a perfect IoT technology. Here is a question for you, what are the different wireless communication technologies available in the marketplace? For further help and technical assistance, you can contact us by commenting below.