ZigBee is a wireless technology developed as an open global
standard to address the unique needs oflow-cost, low-power
wireless M2M networks. The ZigBee
standard operates on the IEEE 802.15.4
physical radio specification and operates in unlicensed bands
including 2.4 GHz, 900 MHz and 868 MHz.
standard to address the unique needs oflow-cost, low-power
wireless M2M networks. The ZigBee
standard operates on the IEEE 802.15.4
physical radio specification and operates in unlicensed bands
including 2.4 GHz, 900 MHz and 868 MHz.
he 802.15.4 specification upon which the ZigBee stack operates
gained ratification by the
Institute of Electrical and Electronics Engineers (IEEE) in 2003.
The specification is a packet-based
radio protocol intended for low-cost, battery-operated devices.
The protocol allows devices to
communicate in a variety of network topologies and can have
battery
life lasting several years.
gained ratification by the
Institute of Electrical and Electronics Engineers (IEEE) in 2003.
The specification is a packet-based
radio protocol intended for low-cost, battery-operated devices.
The protocol allows devices to
communicate in a variety of network topologies and can have
battery
life lasting several years.
 |
| Add caption |
The ZigBee Protocol
The ZigBee protocol has been created and ratified by member companies of the ZigBee Alliance. Over
300 leading semiconductor manufacturers, technology firms,
OEMs and service companies comprise the ZigBee Alliance membership. The ZigBee protocol was designed to provide an easy-to-use wireless data solution characterized by secure,
reliable wireless network architectures.
reliable wireless network architectures.
The ZigBee Advantage
The ZigBee protocol is designed to communicate data through hostile RF environments that are common
in commercial and industrial applications.
ZigBee protocol features include:
- Support for multiple network topologies such as
- point-to-point, point-to-multipoint and mesh
- networks
- Low duty cycle – provides long battery life
- Low latency
- Direct Sequence Spread Spectrum (DSSS)
- Up to 65,000 nodes per network
- 128-bit AES encryption for secure data connections
- Collision avoidance, retries and acknowledgements
While Bluetooth® focuses on connectivity between large packet user devices, such as laptops, phones, and major peripherals, ZigBee is designed to provide highly efficient connectivity between small packet devices. As a result of its simplified operations, which are one to two full orders of
magnitude less complex than a comparable Bluetooth® device, pricing for ZigBee devices is extremely competitive, with full
nodes available for a fraction of the cost of a Bluetooth® node.
ZigBee devices are actively limited to a through-rate of 250 Kbps, compared to Bluetooth®'s much larger pipeline of 1Mbps,
ZigBee devices are actively limited to a through-rate of 250 Kbps, compared to Bluetooth®'s much larger pipeline of 1Mbps,
operating on the 2.4 GHz ISM band, which is available
throughout most of the world.
ZigBee has been developed to meet the growing demand for
ZigBee has been developed to meet the growing demand for
capable wireless networking between numerous low-power
devices. In industry ZigBee is being used for next generation
devices. In industry ZigBee is being used for next generation
automated manufacturing, with small transmitters in every device
on the floor, allowing for communication between devices to a central computer. This new level of communication permits finely-tuned remote monitoring and manipulation. In the
consumer market ZigBee is being explored for everything from linking low-power household devices such as smoke alarms to a central housing control unit, to centralized light controls.
The specified maximum range of operation for ZigBee devices is 250 feet (76m), substantially further than that used by Bluetooth® capable devices, although security concerns raised over "sniping" Bluetooth® devices remotely, may prove to hold true for ZigBee devices as well.
Due to its low power output, ZigBee devices can sustain
consumer market ZigBee is being explored for everything from linking low-power household devices such as smoke alarms to a central housing control unit, to centralized light controls.
The specified maximum range of operation for ZigBee devices is 250 feet (76m), substantially further than that used by Bluetooth® capable devices, although security concerns raised over "sniping" Bluetooth® devices remotely, may prove to hold true for ZigBee devices as well.
Due to its low power output, ZigBee devices can sustain
themselves on a small battery for many months,
or even years, making them ideal for install-and-forget purposes, such as most small household systems. Predictions of ZigBee installation for the future, most based on the explosive use of ZigBee in automated household tasks in China, look to a near
future when upwards of 60 ZigBee devices may be found in an average American home, all communicating with one another
freely and regulating common tasks seamlessly.
Mesh Networks
A key component of the ZigBee protocol is the ability to support mesh networking. In a mesh network, nodes are interconnected with other nodes so that multiple pathways connect each node. Connections between nodes are dynamically updated and optimized through sophisticated, built-in mesh routing table. Mesh networks are decentralized in nature; each node is
capable of self-discovery on the network. Also, as nodes leave
the network, the mesh topology allows the nodes to reconfigure routing paths based on the new network structure. The characteristics of mesh topology and ad-hoc routing provide
greater stability in changing conditions or failure at single nodes.
ZigBee Applications
ZigBee enables broad-based deployment of wireless networks
with low-cost, low-power solutions. It provides the ability to
run for years on inexpensive batteries for a host of monitoring
and control applications. Smart energy/smart grid, AMR
(Automatic Meter Reading), lighting controls, building
automation systems, tank monitoring, HVAC control, medical devices and fleet applications are just some of the many spaces where ZigBee technology is making significant advancements.
