zigbee

ZigBee Origin of word Word ZigBee was originated from word ZigZag indicating cross-shaped network cables and Bee to indicate economical communication method. Word ZigBee was proposed and decided by committee members in early phase of standard committee of ZigBee.

Introduction ZigBee is the set of specs built around the IEEE 802.15.4 wireless protocol. The IEEE is the Institute of Electrical and Electronics Engineers, a non-profit organization dedicated to furthering technology involving electronics and electronic devices. The 802 group is the section of the IEEE involved in network operations and technologies, including mid-sized networks and local networks. Group 15 deals specifically with wireless networking technologies, and includes the now ubiquitous 802.15.1 working group, which is also known as Bluetooth®. The standard itself is regulated by a group known as the ZigBee Alliance, with over 150 members worldwide. 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, 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 capable wireless networking between numerous lowpower 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 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.

ZigBee® Overview ZigBee is a low-power wireless communications technology and international standard protocol for the nextgeneration wireless network, reducing data size and allowing for lower-cost network construction with simplified protocol and limited functionality. ZigBee uses the PHY and MAC layers defined by IEEE® 802.15.4, which is the short-distance wireless communication standard for 2.4 GHz band. ZigBee comprises the ZigBee platform specifications and ZigBee profiles defined by the ZigBee Alliance.

ZigBee Key Features: 1.

2.

3.

4.

Low Power-The benefits of simple, cost-effective, low-power wireless connectivity that ZigBee technology provides address a variety of markets, including industrial and home monitoring, control and automation, as well as health care diagnostics. Freescale provides all the building blocks used in a complete ZigBee-compliant platform solution: the RF transceiver, MAC and ZigBee software, microcontrollers and sensors. The development hardware and reference designs provide developers with the tools they need to easily and quickly implement these building blocks. One solution, one provider—built, tested, compatible and ready for integration. Robust-802.15.4 provides a robust foundation for ZigBee, ensuring a reliable solution in noisy environments. Features such as energy detection, clear channel assessment and channel selection help the device pick the best possible channel, avoiding other wireless networks such as Wi-Fi®. Message acknowledgement helps to ensure that the data was delivered to its destination. Finally, multiple levels of security ensure that the network and data remain intact and secure. Mesh Networking-The ability to cover large areas with routers is one of the key features of ZigBee that helps differentiate itself from other technologies. Mesh networking can extend the range of the network through routing, while self healing increases the reliability of the network by re-routing a message in case of a node failure Interoperability-The ZigBee Alliance helps ensure interoperability between vendors by creating testing and certification programs for ZigBee devices. Users can be assured the devices that go through certification testing and use the ZigBee logo will work with other devices based on the same applications. This provides end customers with the customers with peace of mind while creating brand awareness of products with the ZigBee logo.

Characteristics 1.

2.

ZigBee consumes low electricity supply and can be configured to large scale sensor networks by integrating with sensor (Activity, light, temperature and humidity, etc) and transmitter/receiver devices. This type of structure is defined as foundation technology for sensing, monitoring and controlling. ZigBee has recognized as next generation short-distance wireless communication standard based on strong advantages including lowest costs, lowest energy consumption which can be last 2 years with 2 AA type batteries, scalability of up to 65,000 nodes, simple network configuration and reliability from immediate recovery function from data transmission errors. Especially, ZigBee supports multi-hop function to ensure highest transmission success rates.

3. 2.4GHz and 868/915 MHz dual PHY modes. This represents three license-free bands: 2.4-2.4835 GHz, 868-870 MHz and 902-928 MHz. The number of channels allotted to each frequency band is fixed at sixteen (numbered 11-26), one (numbered 0) and ten (numbered 1-10) respectively. The higher frequency band is applicable worldwide, and the lower band in the areas of North America, Europe, Australia and New Zealand . 4.

Low power consumption, with battery life ranging from months to years. Considering the number of devices with remotes in use at present, it is easy to see that more numbers of batteries need to be provisioned every so often, entailing regular (as well as timely), recurring expenditure. In the ZigBee standard, longer battery life is achievable by either of two means: continuous network connection and slow but sure battery drain, or intermittent connection and even slower battery drain.

5.

Maximum data rates allowed for each of these frequency bands are fixed as 250 kbps @2.4 GHz, 40 kbps @ 915 MHz, and 20 kbps @868 MHz.

6.

High throughput and low latency for low duty-cycle applications (