- Personal area network
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Computer network types by geographical scope A personal area network (PAN) is a computer network used for communication among computer devices, including telephones and personal digital assistants, in proximity to an individual's body. The devices may or may not belong to the person in question. The reach of a PAN is typically a few meters. PANs can be used for communication among the personal devices themselves (intrapersonal communication), or for connecting to a higher level network and the Internet (an uplink).
Personal area networks may be wired with computer buses such as USB and FireWire. A wireless personal area network (WPAN) can also be made possible with wireless network technologies such as IrDA, Bluetooth, Wireless USB, Z-Wave and ZigBee.
Contents
Technology
A Bluetooth PAN is also called a piconet, and is composed of up to 8 active devices in a master-slave relationship (a very large number of devices can be connected in "parked" mode). The first Bluetooth device in the piconet is the master, and all other devices are slaves that communicate with the master. A piconet typically has a range of 10 metres (33 ft), although ranges of up to 100 metres (330 ft) can be reached under ideal circumstances.
Recent innovations in Bluetooth antennas have allowed these devices to greatly exceed the range for which they were originally designed. At DEF CON 12, a group of hackers known as "Flexilis" successfully connected two Bluetooth devices more than half a mile (800 m) away. They used an antenna with a scope and Yagi antenna, all attached to a rifle stock. A cable attached the antenna to a Bluetooth card in a computer. They later named the antenna "The BlueSniper."[citation needed]
Skinplex, another PAN technology, transmits via the capacitive near field of human skin. Skinplex can detect and communicate up to 1 metre (3 ft 3 in) from a human body. It is already used for access control for door locks and jamming protection in convertible car roofs.
Wireless PAN
A wireless personal area network (WPAN) is a personal area network - a network for interconnecting devices centered around an individual person's workspace - in which the connections are wireless. Typically, a wireless personal area network uses some technology that permits communication within about 10 metres (33 ft) such as Bluetooth, which was used as the basis for a new standard, IEEE 802.15.
A WPAN could serve to interconnect all the ordinary computing and communicating devices that many people have on their desk or carry with them today - or it could serve a more specialized purpose such as allowing the surgeon and other team members to communicate during an operation.
A key concept in WPAN technology is known as "plugging in". In the ideal scenario, when any two WPAN-equipped devices come into close proximity (within several meters of each other) or within a few kilometers of a central server, they can communicate as if connected by a cable. Another important feature is the ability of each device to lock out other devices selectively, preventing needless interference or unauthorized access to information.
The technology for WPANs is in its infancy and is undergoing rapid development. Proposed operating frequencies are around 2.4 GHz in digital modes. The objective is to facilitate seamless operation among home or business devices and systems. Every device in a WPAN will be able to plug in to any other device in the same WPAN, provided they are within physical range of one another. In addition, WPANs worldwide will be interconnected. Thus, for example, an archeologist on site in Greece might use a PDA to directly access databases at the University of Minnesota in Minneapolis, and to transmit findings to that database.
Connecting devices
Connecting devices allow hardware networking devices to communicate with each other. The three kinds of wireless technologies are Bluetooth, infrared, and Wireless Fidelity (WiFi).
Bluetooth
Bluetooth uses short-range radio waves over distances up to approximately 10 metres. For example, Bluetooth devices such as a keyboards, pointing devices, audio head sets, printers may connect to Personal digital assistants (PDAs), cell phones, or computers wirelessly.
Infrared
Infrared communications (IR) or IrDA (Infrared Data Association) uses infrared light, which has a frequency below the human eye's sensitivity. It is used in cell phones and TV remote controls. Typical devices include printers, keyboards, and other serial data interfaces.[1]
WiFi
WiFi (wireless fidelity) uses radio waves for connection over distances up to around 91 metres, usually in a local area network (LAN) environment. Wifi can be used to connect local area networks, to connect cellphones to the Internet to download music and other multimedia, to allow PC multimedia content to be stream to the TV (Wireless Multimedia Adapter), and to connect video game consoles to their networks (Nintendo WiFi Connection).
See also
- Ambient networks
- Bluetooth
- DASH7
- Skinplex
- IEEE 802.15
- Internalnet
- Ultra-wideband and FM-UWB networks
- Z-Wave
- ZigBee
- 6lowpan
- RuBee
References
- ^ Charles D. Knutson with Jeffrey M. Brown, IrDA Principles and Protocols, 2004, ISBN 0-9753892-0-3
External links
- Intrabody Signalling by Tom Zimmerman and Neil Gershenfeld
- ASPAN - Next Generation Personal Area Networks
Categories:- Wireless networking
- Personal area networks
- Bluetooth
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