- Wireless access point
computer networking, a wireless access point (WAP or AP) is a device that allows wireless communication devices to connect to a wireless networkusing Wi-Fi, Bluetoothand related standards. The WAP usually connects to a wired network, and can relay data between the wireless devices (such as computers or printers) and wired devices on the network.
Common WAP Applications
A typical corporate use involves attaching several WAPs to a wired network and then providing wireless access to the office LAN. Within the range of the WAPs, the wireless end user has a full network connection with the benefit of mobility. In this instance, the WAP functions as a gateway for clients to access the wired network.
topology, a "lily-pad network", consists of a series of access points spread over a large area, each connected to a different network. This provides hot spots where wireless clients can connect to the Internetwithout regard for the particular networks to which they have attached for the moment. The concept can become common in large cities, where a combination of coffeehouses, libraries, other public spaces offering wireless access, as well as privately owned open access points, allow clients to stay more or less continuously connected to a network (like hopping from lily pad to lilypad), while moving around.
Home wireless networks, the majority, generally have only one WAP to connect all the computers in a home. Most are
wireless routers, meaning converged devices that include a WAP, Ethernet router, and often a switch in the same package. Many also converge a broadband modem. Most owners leave their encryption settings at default, hence neighbors can use them. In places where most homes have their own WAP within range of the neighbors' WAP, it's possible for technically savvy people to turn off their encryption and set up a wireless community network, creating an intra-city communication network without the need of wired networks.
A WAP may also act as the network's arbitrator, negotiating when each nearby client device can transmit. However, the vast majority of currently installed
IEEE 802.11networks do not implement this, using a distributed pseudo-random algorithm instead.
Access Point vs. Ad-Hoc Network
Some people confuse Access Point and Ad-Hoc Network. An Ad-Hoc network uses a connection between two or more devices without using an access point: the devices communicate directly. An Ad-hoc network might be useful in some situations, such as for a quick data exchange, or for a Multiplayer LAN game, because it is easy to set up and does not require an access point. Due to its peer-to-peer layout, Ad-hoc connections are similar to Bluetooth ones, and are generally not recommended for a permanent installation.
Some people access the internet via
ad-hoc networks, using features like Windows' Internet Connection Sharing. This is fine temporarily, and with a small number of devices that are close to each other, but an Ad-hoc networks don't scale well, and operate better to transfer data between nearby nodes. In contrast, internet traffic will converge to the nodes with direct internet connection, potentially congesting these nodes. For internet-enabled node, Access Points have a clear advantage, since an AP is designed to handle this load.
IEEE 802.11WAP can typically communicate with 30 client systems located within a radiusof 100 m. However, the actual range of communication can vary significantly, depending on such variables as indoor or outdoor placement, height above ground, nearby obstructions, other electronic devices that might actively interfere with the signal by broadcasting on the same frequency, type of antenna, the current weather, operating radio frequency, and the power output of devices. Network designers can extend the range of WAPs through the use of repeaters and reflectors, which can bounce or amplify radio signals that ordinarily would go un-received. In experimental conditions, wireless networking has operated over distances of several kilometers.
Most jurisdictions have only a limited number of frequencies legally available for use by wireless networks. Usually, adjacent WAPs will use different frequencies to communicate with their clients in order to avoid
interferencebetween the two nearby systems. But wireless devices can "listen" for data traffic on other frequencies, and can rapidly switch from one frequency to another to achieve better reception on a different frequency. However, the limited number of frequencies becomes problematic in crowded downtown areas with tall buildings using multiple WAPs. In such an environment, signal overlap becomes an issue causing interference, which results in signal dropage and data errors.
Wireless networking lags behind wired networking in terms of increasing bandwidth and
throughput. While (as of 2004) typical wireless devices for the consumer market can reach speeds of 11 Mbit/s ( megabits per second) (IEEE 802.11b) or 54 Mbit/s ( IEEE 802.11a, IEEE 802.11g), wired hardware of similar cost reaches 1000 Mbit/s ( Gigabit Ethernet). One impediment to increasing the speed of wireless communications comes from Wi-Fi's use of a shared communications medium, so a WAP is only able to use somewhat less than half the actual over-the-air rate for data throughput. Thus a typical 54 MBit/s wireless connection actually carries TCP/IPdata at 20 to 25 Mbit/s. Users of legacy wired networks expect the faster speeds, and people using wireless connections keenly want to see the wireless networks catch up.
As of 2007 a new standard for wireless,
802.11nis awaiting final certification from IEEE. This new standard operates at speeds up to 540 Mbit/s and at longer distances (~50 m) than 802.11g. Use of legacy wired networks (especially in consumer applications) is expected to decline sharply as the common 100 Mbit/s speed is surpassed and users no longer need to worry about running wires to attain high bandwidth.
By the year 2008 the 802.11n based access points and client devices already take fair share of the market place. Major chipset manufacturers are Atheros and Broadcom for Access Point side and Atheros, Broadcom and Intel for client side. The MiMO operation between different manufacturers chipset is currently not supported (ie. Atheros based Access Point and Intel based client card built into a laptop will link using 802.11g instead of 802.11n).
Interferencecan commonly cause problems with wireless networking reception, as many devices operate using the 2.4 GHz ISM band. A nearby wireless phone or anything with greater transmission power within close proximity can markedly reduce the perceived signal strength of a wireless access point. Microwave ovens are also known to interfere with wireless networks.
Wireless access has special
securityconsiderations. Many wired networks base the security on physical access control, trusting all the users on the local network, but if wireless access points are connected to the network, anyone on the street or in the neighboring office could connect.
The most common solution is wireless traffic encryption. Modern access points come with built-in encryption. The first generation encryption scheme WEP proved easy to crack; the second and third generation schemes, WPA and WPA2, are considered secure if a strong enough
passwordor passphraseis used.
Some WAPs support hotspot style authentication using
RADIUSand other authentication servers. For example, DD-WRTv24 supports Chilisofthotspot authentication which separates the WLAN from the hard wired LAN so that your guests cannot browse the local wired network.
* Hotspots - access points or wireless networks open to the public
Wireless LAN- networks consisting of zero or more access points plus devices
LWAPP- Lightweight Access Point Protocol used to manage a large set of WAPs
WarXing- searching for open networks
Femtocell- a local-area base stationusing cellular networkstandards such as UMTS, rather than Wi-Fi
WiMAX- wide-area wireless standard that has a few elements in common with Wi-Fi
* [http://wi-fi.org/ Wi-Fi Alliance]
* [http://tetcos.com/lant.html# Wi-Fi Trainer]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Wireless Access Point — UK US noun [C] INTERNET, IT ► WAP(Cf. ↑WAP) … Financial and business terms
Wireless Access Point — Router mit integriertem WLAN Access Point, links per Kabel mit dem LAN (zweites Kabel von unten) und drei Endgeräten (obere drei Kabel), über die Antennen drahtlos mit weiteren Endgeräten verbunden. Ein Wireless Access Point [ˈwaɪəlɪs ˈæksɛs… … Deutsch Wikipedia
Access Point — Wireless Access Point, links per Kabel mit dem Internet (unten) und drei Endgeräten verbunden, über die Antennen drahtlos mit weiteren Endgeräten. Ein Wireless Access Point [ˈwaɪəlɪs ˈæksɛs pɔɪnt] (WAP, deutsch „Funkzugangsknoten“) ist ein… … Deutsch Wikipedia
Wireless Access Points — Wireless Access Point, links per Kabel mit dem Internet (unten) und drei Endgeräten verbunden, über die Antennen drahtlos mit weiteren Endgeräten. Ein Wireless Access Point [ˈwaɪəlɪs ˈæksɛs pɔɪnt] (WAP, deutsch „Funkzugangsknoten“) ist ein… … Deutsch Wikipedia
Access Point Name — or APN is the name of an access point for GPRS.An access point is: * An Internet network to which a mobile can be connected * A set of settings which are used for that connection * A particular option in a set of settings in a mobile phoneWhen a… … Wikipedia
Access Point — can refer to: *Access Point (Antarctica), a location on Anvers Island, Antarctica *Wireless access point, a wireless networking device … Wikipedia
access point — UK US noun [C] IT, COMMUNICATIONS ► a piece of computer equipment that allows computers to be connected together without wires to share information: »Wireless networks need an access point, or base station a node that funnels data to and from the … Financial and business terms
Access\ Point — Knotenpunkte für den Einstieg ins Netzwerk bei funkbasierten Netzwerken (Wireless LANs). Die möglichst lückenlose Versorgung mit strategisch günstig positionierten Access Points steht beim Aufbau von WLAN Netzwerken in den größeren Städten im… … Online-Wörterbuch Deutsch-Lexikon
access point — noun A device, such as a WLAN or Internet modem, that permits wireless devices to connect to a network. Syn: wi fi array … Wiktionary
WLAN Access Point — Wireless Access Point, links per Kabel mit dem Internet (unten) und drei Endgeräten verbunden, über die Antennen drahtlos mit weiteren Endgeräten. Ein Wireless Access Point [ˈwaɪəlɪs ˈæksɛs pɔɪnt] (WAP, deutsch „Funkzugangsknoten“) ist ein… … Deutsch Wikipedia