02-08-2011, 03:54 PM
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Abstract
wireless communication may be used to transfer information over short distances (a few meters as in television remote control) or long distances (thousands or millions of kilometers for radio communications). The term is often shortened to "wireless". This paper completely deals about a wireless communication, specially about a wireless technology zigbee (802.15.4)IEEE, where ZigBee is a standard that defines a set of communication protocols for low-data-rate short-range wireless networking, this paper includes entire architecture of this wireless technology, then it states about the frequencies of operation and its data rates ,interoperability, device types, device roles, zigbee network topologies, zigBee and IEEE 802.15.4 communication basics, association and disassociation, binding, zigbee self forming and self healing characteristics, and detail about zigBee and IEEE 802.15.4 networking layer functions about then it states about the real time examples where it is been mostly preferred, they are about Home automation security system and light control system.
1.INTRODUCTION
Wireless operations permits services, such as long range communications, that are impossible or impractical to implement with the use of wires. The term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g. radio transmitters and receivers, remote controls, computer networks, network terminals, etc.) which use some form of energy (e.g radio frequency (RF), infrared light, laser light, visible light, acoustic energy, etc.) to transfer information without the use of wires. Information is transferred in this manner over both short and long distances. In which my pick and, i would like exhibit about a wireless technology called as zigbee.
ZigBee is a standard that defines a set of communication protocols for low-data-rate short-range wireless networking. ZigBee-based wireless devices operate in 868 MHz, 915 MHz, and 2.4 GHz frequency bands. The maximum data rate is 250 K bits per second. ZigBee is targeted mainly for battery-powered applications where low data rate, low cost, and long battery life are main requirements.
In many ZigBee applications, the total time the wireless device is engaged in any type of activity is very limited; the device spends most of its time in a power-saving mode, also known as sleep mode. As a result, ZigBee enabled devices are capable of being operational for several years before their batteries need to be replaced.
• ZIGBEE IS HIGHLY RELIABLE
Wireless communication is inherently unreliable. Prove this to yourself by walking around with your cell phone, then step into an elevator. Anyone who has used a cell phone has experienced dropped calls or poor reception. It’s all because radio waves arejust that: waves. They run into interference patterns, can be blocked by metal, water or a lot of concrete, and vary depending on many complex factors including antenna design, power amplification, and even weather conditions.
Wireless control, however, doesn’t usually have the same remedies normally associated with a cell phone call, of moving to find better reception, or waiting to try back later.
The ZigBee Alliance understands this, and so the ZigBee specification reflects this need.
ZigBee achieves high reliability in a number of ways:
● IEEE 802.15.4 with O-QPSK and DSSS
● CSMA-CA
● 16-bit CRCs
● Acknowledgments at each hop
● Mesh networking to find reliable route
● End-to-end acknowledgments to verify data made it to the destination.
• ZIGBEE IS COST EFFECTIVE
Most of the entries in the table are the price for a combination MCU and radio. That’s right, a single chip solution yields prices in the $3 to $5 range, on average. One of the entries, the Freescale MC13203, is a stand-alone radio that can be combined with any MCU or CPU.
The final two entries, the Digi International XBee and the Panasonic PAN802154, are complete, ready-to-ship, precertified modules. Connect a couple of AA or AAA batteries and a sensor or actuator to these boards, put it in some plastic enclosure, and ship your product. These prices are for low-volume sales. OEM and higher volume (10,000 _ units) knock off about a dollar, as a rule of thumb. And, as the competition for the 802.15.4 market stiffens, the prices will likely be brought down even further. Some have predicted that the 802.15.4 radio market will see prices around $1 in quantity over the next three to five years.
But the low cost of ZigBee isn’t just about low silicon costs. In addition to low MCU and
radio costs, developing applications for ZigBee is cheap in other ways:
● It uses the 2.4 GHz spectrum for worldwide distribution.
Abstract
wireless communication may be used to transfer information over short distances (a few meters as in television remote control) or long distances (thousands or millions of kilometers for radio communications). The term is often shortened to "wireless". This paper completely deals about a wireless communication, specially about a wireless technology zigbee (802.15.4)IEEE, where ZigBee is a standard that defines a set of communication protocols for low-data-rate short-range wireless networking, this paper includes entire architecture of this wireless technology, then it states about the frequencies of operation and its data rates ,interoperability, device types, device roles, zigbee network topologies, zigBee and IEEE 802.15.4 communication basics, association and disassociation, binding, zigbee self forming and self healing characteristics, and detail about zigBee and IEEE 802.15.4 networking layer functions about then it states about the real time examples where it is been mostly preferred, they are about Home automation security system and light control system.
1.INTRODUCTION
Wireless operations permits services, such as long range communications, that are impossible or impractical to implement with the use of wires. The term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g. radio transmitters and receivers, remote controls, computer networks, network terminals, etc.) which use some form of energy (e.g radio frequency (RF), infrared light, laser light, visible light, acoustic energy, etc.) to transfer information without the use of wires. Information is transferred in this manner over both short and long distances. In which my pick and, i would like exhibit about a wireless technology called as zigbee.
ZigBee is a standard that defines a set of communication protocols for low-data-rate short-range wireless networking. ZigBee-based wireless devices operate in 868 MHz, 915 MHz, and 2.4 GHz frequency bands. The maximum data rate is 250 K bits per second. ZigBee is targeted mainly for battery-powered applications where low data rate, low cost, and long battery life are main requirements.
In many ZigBee applications, the total time the wireless device is engaged in any type of activity is very limited; the device spends most of its time in a power-saving mode, also known as sleep mode. As a result, ZigBee enabled devices are capable of being operational for several years before their batteries need to be replaced.
• ZIGBEE IS HIGHLY RELIABLE
Wireless communication is inherently unreliable. Prove this to yourself by walking around with your cell phone, then step into an elevator. Anyone who has used a cell phone has experienced dropped calls or poor reception. It’s all because radio waves arejust that: waves. They run into interference patterns, can be blocked by metal, water or a lot of concrete, and vary depending on many complex factors including antenna design, power amplification, and even weather conditions.
Wireless control, however, doesn’t usually have the same remedies normally associated with a cell phone call, of moving to find better reception, or waiting to try back later.
The ZigBee Alliance understands this, and so the ZigBee specification reflects this need.
ZigBee achieves high reliability in a number of ways:
● IEEE 802.15.4 with O-QPSK and DSSS
● CSMA-CA
● 16-bit CRCs
● Acknowledgments at each hop
● Mesh networking to find reliable route
● End-to-end acknowledgments to verify data made it to the destination.
• ZIGBEE IS COST EFFECTIVE
Most of the entries in the table are the price for a combination MCU and radio. That’s right, a single chip solution yields prices in the $3 to $5 range, on average. One of the entries, the Freescale MC13203, is a stand-alone radio that can be combined with any MCU or CPU.
The final two entries, the Digi International XBee and the Panasonic PAN802154, are complete, ready-to-ship, precertified modules. Connect a couple of AA or AAA batteries and a sensor or actuator to these boards, put it in some plastic enclosure, and ship your product. These prices are for low-volume sales. OEM and higher volume (10,000 _ units) knock off about a dollar, as a rule of thumb. And, as the competition for the 802.15.4 market stiffens, the prices will likely be brought down even further. Some have predicted that the 802.15.4 radio market will see prices around $1 in quantity over the next three to five years.
But the low cost of ZigBee isn’t just about low silicon costs. In addition to low MCU and
radio costs, developing applications for ZigBee is cheap in other ways:
● It uses the 2.4 GHz spectrum for worldwide distribution.
