Wireless network
Encyclopedia
Wireless network refers to any type of computer network
that is not connected by cables of any kind. It is a method by which homes, telecommunications network
s and enterprise (business) installations avoid the costly process of introducing cables into a building, or as a connection between various equipment locations. Wireless
telecommunication
s networks are generally implemented and administered using a transmission system called radio waves
. This implementation takes place at the physical level (layer) of the network structure.
(WPANs) interconnect devices within a relatively small area, that is generally within a person's reach. For example, both Bluetooth
radio and invisible Infrared
light provides a WPAN for interconnecting a headset to a laptop. ZigBee
also supports WPAN applications. Wi-Fi PANs are becoming commonplace (2010) as equipment designers start to integrate Wi-Fi into a variety of consumer electronic devices. Intel "My WiFi" and Windows 7 "virtual
Wi-Fi" capabilities have made Wi-Fi PANs simpler and easier to set up and configure.
. The use of spread-spectrum or OFDM technologies may allow users to move around within a local coverage area, and still remain connected to the network.
Products using the IEEE 802.11
WLAN standards are marketed under the Wi-Fi
brand name.
Fixed wireless
technology implements point-to-point links between computers or networks at two distant locations, often using dedicated microwave
or modulated laser light beams over line of sight
paths. It is often used in cities to connect networks in two or more buildings without installing a wired link.
Each node forwards messages on behalf of the other nodes.
Mesh networks can "self heal", automatically re-routing around a node that has lost power.
using parabolic dishes on the 2.4 GHz band, rather than omnidirectional antenna
s used with smaller networks. A typical system contains base station gateways, access points and wireless bridging relays. Other configurations are mesh systems where each access point acts as a relay also. When combined with renewable energy systems such as photo-voltaic solar panels or wind systems they can be stand alone systems.
s, cellular telephone networks
routinely carry data in addition to telephone conversations:
s to communicate across the world. Emergency service
s such as the police utilize wireless networks to communicate effectively as well. Individuals and businesses use wireless networks to send and share data rapidly, whether it be in a small office building or across the world.
The performance of wireless networks satisfies a variety of applications such as voice and video. The use of this technology also gives room for future expansions. As wireless networking has become commonplace, sophistication increased through configuration of network hardware and software.
Space is also created in homes as a result of eliminating clutters of wiring. This techonology allows for an alternative to installing physical network mediums such as TP
s, coax
es, or Fiber-optic
s, which can also be expensive.
for sharing printers, scanners, and high speed internet connections. WLANs help save from the cost of installation of cable mediums, save time from physical installation, and also creates mobility for devices connected to the network.
Wireless networks are simple and require one single wireless access point
connected directly to the Internet via a router.
refused to agree to installation of a wireless network citing a California Public Utilities Commission study which said that the possible risk of tumors and other diseases due to exposure to electromagnetic fields (EMFs) needs to be further investigated.
Wireless access points are also often close to humans, but the drop off in power over distance is fast, following the inverse-square law
.
The HPA's
position is that “...radio frequency (RF) exposures from WiFi are likely to be lower than those from mobile phones.” It also saw “...no reason why schools and others should not use WiFi equipment.” In October 2007, the HPA launched a new “systematic” study into the effects of WiFi networks on behalf of the UK government, in order to calm fears that had appeared in the media in a recent period up to that time". Dr Michael Clark, of the HPA, says published research on mobile phones and masts
does not add up to an indictment of WiFi.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
that is not connected by cables of any kind. It is a method by which homes, telecommunications network
Telecommunications network
A telecommunications network is a collection of terminals, links and nodes which connect together to enable telecommunication between users of the terminals. Networks may use circuit switching or message switching. Each terminal in the network must have a unique address so messages or connections...
s and enterprise (business) installations avoid the costly process of introducing cables into a building, or as a connection between various equipment locations. Wireless
Wireless
Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications...
telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
s networks are generally implemented and administered using a transmission system called radio waves
Radio waves
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. Like all other electromagnetic waves,...
. This implementation takes place at the physical level (layer) of the network structure.
Wireless PAN
Wireless Personal Area NetworksPersonal area network
A personal area network 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...
(WPANs) interconnect devices within a relatively small area, that is generally within a person's reach. For example, both Bluetooth
Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
radio and invisible Infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
light provides a WPAN for interconnecting a headset to a laptop. ZigBee
ZigBee
ZigBee is a specification for a suite of high level communication protocols using small, low-power digital radios based on an IEEE 802 standard for personal area networks. Applications include wireless light switches, electrical meters with in-home-displays, and other consumer and industrial...
also supports WPAN applications. Wi-Fi PANs are becoming commonplace (2010) as equipment designers start to integrate Wi-Fi into a variety of consumer electronic devices. Intel "My WiFi" and Windows 7 "virtual
Virtual
The term virtual is a concept applied in many fields with somewhat differing connotations, and also, differing denotations.The term has been defined in philosophy as "that which is not real" but may display the salient qualities of the real....
Wi-Fi" capabilities have made Wi-Fi PANs simpler and easier to set up and configure.
Wireless LAN
A wireless local area network (WLAN) links two or more devices over a short distance using a wireless distribution method, usually providing a connection through an access point for Internet accessInternet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
. The use of spread-spectrum or OFDM technologies may allow users to move around within a local coverage area, and still remain connected to the network.
Products using the IEEE 802.11
IEEE 802.11
IEEE 802.11 is a set of standards for implementing wireless local area network computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee . The base version of the standard IEEE 802.11-2007 has had subsequent...
WLAN standards are marketed under the Wi-Fi
Wi-Fi
Wi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20...
brand name.
Fixed wireless
Fixed wireless
Fixed wireless is the operation of wireless devices or systems used to connect two fixed locations with a radio or other wireless link, such as laser bridge. Usually, fixed wireless is part of a wireless LAN infrastructure. The purpose of a fixed wireless link is to enable data communications...
technology implements point-to-point links between computers or networks at two distant locations, often using dedicated microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
or modulated laser light beams over line of sight
Line-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...
paths. It is often used in cities to connect networks in two or more buildings without installing a wired link.
Wireless mesh network
A wireless mesh network is a wireless network made up of radio nodes organized in a mesh topology.Each node forwards messages on behalf of the other nodes.
Mesh networks can "self heal", automatically re-routing around a node that has lost power.
Wireless MAN
Wireless Metropolitan Area Networks are a type of wireless network that connects several wireless LANs.- WiMAXWiMAXWiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
is a type of Wireless MAN and is described by the IEEE 802.16IEEE 802.16IEEE 802.16 is a series of Wireless Broadband standards authored by the Institute of Electrical and Electronics Engineers . The IEEE Standards Board in established a working group in 1999 to develop standards for broadband Wireless Metropolitan Area Networks...
standard.
Wireless WAN
Wireless wide area networks are wireless networks that typically cover large areas, such as between neighboring towns and cities, or city and suburb. These networks can be used to connect branch offices of business or as a public internet access system. The wireless connections between access points are usually point to point microwave linksMicrowave transmission
Microwave transmission refers to the technology of transmitting information or power by the use of radio waves whose wavelengths are conveniently measured in small numbers of centimeters; these are called microwaves. This part of the radio spectrum ranges across frequencies of roughly...
using parabolic dishes on the 2.4 GHz band, rather than omnidirectional antenna
Omnidirectional antenna
In radio communication, an omnidirectional antenna is an antenna which radiates radio wave power uniformly in all directions in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis. This radiation pattern is often...
s used with smaller networks. A typical system contains base station gateways, access points and wireless bridging relays. Other configurations are mesh systems where each access point acts as a relay also. When combined with renewable energy systems such as photo-voltaic solar panels or wind systems they can be stand alone systems.
Mobile devices networks
With the development of smartphoneSmartphone
A smartphone is a high-end mobile phone built on a mobile computing platform, with more advanced computing ability and connectivity than a contemporary feature phone. The first smartphones were devices that mainly combined the functions of a personal digital assistant and a mobile phone or camera...
s, cellular telephone networks
Cellular network
A cellular network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a cell site or base station. When joined together these cells provide radio coverage over a wide geographic area...
routinely carry data in addition to telephone conversations:
- Global System for Mobile CommunicationsGlobal System for Mobile CommunicationsGSM , is a standard set developed by the European Telecommunications Standards Institute to describe technologies for second generation digital cellular networks...
(GSM): The GSM network is divided into three major systems: the switching system, the base station system, and the operation and support system. The cell phone connects to the base system station which then connects to the operation and support station; it then connects to the switching station where the call is transferred to where it needs to go. GSM is the most common standard and is used for a majority of cell phones. - Personal Communications ServicePersonal Communications ServiceAt the most basic level Personal Communications Service or PCS describes a set of wireless communications capabilities that allows some combination of terminal mobility, personal mobility, and service profile management...
(PCS): PCS is a radio band that can be used by mobile phones in North America and South Asia. Sprint happened to be the first service to set up a PCS. - D-AMPS: Digital Advanced Mobile Phone Service, an upgraded version of AMPS, is being phased out due to advancement in technology. The newer GSM networks are replacing the older system.
Uses
Some examples of usage include Cellular phones which are part of everyday wireless networks, allowing easy personal communications. Another example, Inter-continental network systems, use radio satelliteSatellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s to communicate across the world. Emergency service
Emergency service
Emergency services are organizations which ensure public safety and health by addressing different emergencies. Some agencies exist solely for addressing certain types of emergencies whilst others deal with ad hoc emergencies as part of their normal responsibilities...
s such as the police utilize wireless networks to communicate effectively as well. Individuals and businesses use wireless networks to send and share data rapidly, whether it be in a small office building or across the world.
General
In a general sense, wireless networks offer a vast variety of uses by both business and home users."Now, the industry accepts a handful of different wireless technologies. Each wireless technology is defined by a standard that describes unique functions at both the Physical and the Data Link layers of the OSI Model. These standards differ in their specified signaling methods, geographic ranges, and frequency usages, among other things. Such differences can make certain technologies better suited to home networks and others better suited to network larger organizations."
Performance
Each standard varies in geographical range, thus making one standard more ideal than the next depending on what it is one is trying to accomplish with a wireless network.The performance of wireless networks satisfies a variety of applications such as voice and video. The use of this technology also gives room for future expansions. As wireless networking has become commonplace, sophistication increased through configuration of network hardware and software.
Space
Space is another characteristic of wireless networking . Wireless networks offer many advantages when it comes to difficult-to-wire areas trying to communicate such as across a street or river, a warehouse on the other side of the premise or buildings that are physically separated but operate as one. Wireless networks allow for users to designate a certain space which the network will be able to communicate with other devices through that network.Space is also created in homes as a result of eliminating clutters of wiring. This techonology allows for an alternative to installing physical network mediums such as TP
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
s, coax
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
es, or Fiber-optic
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
s, which can also be expensive.
Business
Organizational end users integrate wireless LANs into corporate information systems. These uses of wireless networking are now seen as practical and cost effective for companies to compete in a global market. Wireless technologies are applicable to all industries, especially for those that stress immediate processing. These industries are finding creative and innovating ways to place portable computers in industry works that are hands on such as doctors, nurses, warehouse clerks, inspectors, claims adjustors, real estate agents, and so on. By using wireless technology, businesses are able to couple portable devices with a database and specific applications which in turn meet mobility needs.Home
For homeowners, wireless technology is an effective option as compared to ethernetEthernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
for sharing printers, scanners, and high speed internet connections. WLANs help save from the cost of installation of cable mediums, save time from physical installation, and also creates mobility for devices connected to the network.
Wireless networks are simple and require one single wireless access point
Wireless access point
In computer networking, a wireless access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth or related standards...
connected directly to the Internet via a router.
Environmental concerns
Starting around 2009, there have been increased concerns about the safety of wireless communications, despite little evidence of health risks so far. The president of Lakehead UniversityLakehead University
Lakehead University is a public research university in Thunder Bay, and Orillia, Ontario, Canada.Lakehead University, shortened to 'Lakehead U', or 'LU', is non-denominational and provincially supported. It has undergraduate and graduate programs and a medical school.The school has more than 45,000...
refused to agree to installation of a wireless network citing a California Public Utilities Commission study which said that the possible risk of tumors and other diseases due to exposure to electromagnetic fields (EMFs) needs to be further investigated.
Wireless access points are also often close to humans, but the drop off in power over distance is fast, following the inverse-square law
Inverse-square law
In physics, an inverse-square law is any physical law stating that a specified physical quantity or strength is inversely proportional to the square of the distance from the source of that physical quantity....
.
The HPA's
Health Protection Agency
The Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...
position is that “...radio frequency (RF) exposures from WiFi are likely to be lower than those from mobile phones.” It also saw “...no reason why schools and others should not use WiFi equipment.” In October 2007, the HPA launched a new “systematic” study into the effects of WiFi networks on behalf of the UK government, in order to calm fears that had appeared in the media in a recent period up to that time". Dr Michael Clark, of the HPA, says published research on mobile phones and masts
Radio masts and towers
Radio masts and towers are, typically, tall structures designed to support antennas for telecommunications and broadcasting, including television. They are among the tallest man-made structures...
does not add up to an indictment of WiFi.
See also
- Exposed terminal problemExposed terminal problemIn wireless networks, the exposed node problem occurs when a node is prevented from sending packets to other nodes due to a neighboring transmitter. Consider an example of 4 nodes labeled R1, S1, S2, and R2, where the two receivers are out of range of each other, yet the two transmitters in the...
- Physical layerPhysical layerThe physical layer or layer 1 is the first and lowest layer in the seven-layer OSI model of computer networking. The implementation of this layer is often termed PHY....
- Public Safety NetworkPublic safety networkA public safety network is a wireless communications network used by emergency services organizations, such as police, fire and emergency medical services, to prevent or respond to incidents that harm or endanger persons or property....
- Wireless community networkWireless community networkWireless community networks or wireless community projects are the organizations that attempt to take a grassroots approach to providing a viable alternative to municipal wireless networks for consumers....
- Wireless access pointWireless access pointIn computer networking, a wireless access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth or related standards...
- Wireless LAN client comparisonWireless LAN client comparisonEvery wireless LAN network consists of an access point, such as a wireless router, and one or more wireless adapters. Each adapter is controlled by software known as a wireless LAN client, or wireless connection management utility....
- RuBeeRuBeeRuBee is a two way, active wireless protocol designed for harsh environment, high security asset visibility applications. RuBee utilizes Long Wave magnetic signals to send and receive short data packets in a local regional network...
- Wireless site surveyWireless site surveyA wireless site survey, sometimes called an RF site survey or wireless survey, is the process of planning and designing a wireless network, to provide a wireless solution that will deliver the required wireless coverage, data rates, network capacity, roaming capability and Quality of Service...