WLAN

A wireless LAN, or WLANLAN WLAN, is a local area network that does not have wired Ethernet connections. A WLAN can be either an extension to a current wired network or an alternative to it. Use of a WLAN adds flexibility to networking. A WLAN allows users to move around while keeping their computer connected, without having to depend on Ethernet cables.

A wireless LAN, or WLANLAN WLANs try to provide all the features of wired LANs, but without the wires. The only differences that is noticeable to the end user  Is the speed (ranging from 1 to 54Mbps, with some manufacturers currently offering proprietary 108Mbps solutions)  And security (the wireless access point is shared among everybody nearby, so security issues exist with WLANs that don't exist for wired networks).

A wireless LAN, or WLANLAN Areas covered A small office A large campus, with neighborhood and city-wide ranges planned for the future. Commonly, WLANs employ access points that provide access within a radius of 65 to 300 feet.

WLAN types The private home or small business WLAN: This consists of one or two access points covering around a 100- to 200-foot radius.

WLAN types The enterprise class WLAN: This type has a larger number of individual access points covering a wider area. The access points themselves have features not needed for a home or small office, like better security, authentication, remote management, and tools to help integrate with existing networks. Each access point has a larger coverage area than home or small office products, and all are designed to work together to cover a much larger area.

WLAN Types The Wireless Metropolitan Area Network (WMAN): A WMAN covers an area from multiple city blocks up to a city's boundaries. The most common type of WMAN is a collection of individual enterprise class wireless networks that collectively allow users to access all of them. In most places, WMANs usually consist of wireless networks belonging to several businesses or Internet service providers.Internet service providers The WMAN is also the point where you start seeing different technologies and standards. Again, the most common WMAN is basically a group of individual access points and WLANs. While you will see the term Metropolitan Area Network (MAN), don't confuse it with a Wireless Metropolitan Area Network (WMAN). Aside from the fact that MANs tend to be wired networks, they usually exist to provide connectivity to local ISPs, or to business and enterprise class LANs. In contrast, a WMAN exists to provide connectivity directly to an end user. In other words, a MAN normally acts as a backbone, while a WMAN acts as the "last mile" connection directly to a user's computer.

How does it work? WLAN is a wireless local area network, which is the linking of two or more computers without using wires.wirelesslocal area network WLAN utilizes spread-spectrum modulation technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set.spread-spectrumradio waves This gives users the mobility to move around within a broad coverage area and still be connected to the network.

Prospects For the home user, wireless has become popular due to ease of installation, and location freedom with the gaining popularity of laptops.laptops Public businesses such as coffee shops or malls have begun to offer wireless access to their customers; some are even provided as a free service. Large wireless network projects are being put up in many major cities.

WLAN The WLAN consists of nodes and access points. Node  A computer with an antenna/ network adapter  A peripheral with an antenna/ network adapter Access points  Transmitters/receivers between the nodes

Infrared Technology Uses high frequencies for transmission just below visible light. Cannot penetrate opaque objects. Either directed or diffused technology is used. In directed it is the line of sight where the emitter directs the IR to the detector. In diffused the Emitter transmits the IR signal it bounces off the ceiling and the detectors are capable of detecting the reflected signal. WLANs typically use this IR.

WLAN modes of operation It has two basic modes of operation: Adhoc (distributed control) Infrastructure LAN (Centralized control)

Adhoc Mode Ad hoc mode enables peer-to-peer transmission between mobile units.  A peer-to-peer (P2P) allows wireless devices to directly communicate with each other. Wireless devices within range of each other can discover and communicate directly without involving central access points. This method is typically used by two computers so that they can connect to each other to form a network.peer-to-peer  If a signal strength meter is used in this situation, it may not read the strength accurately and can be misleading, because it registers the strength of the strongest signal, which may be the closest computer.

Infrastructure Mode Infrastructure mode in which mobile units communicate through an access point that serves as a bridge to a wired network infrastructure A bridge can be used to connect networks, typically of different types. A wireless Ethernet bridge allows the connection of devices on a wired Ethernet network to a wireless network. The bridge acts as the connection point to the Wireless LAN.Ethernet

Wireless bridge This is a hardware component used to connect two or more network segments which are physically separated.network segments Consumers have been presented with wireless bridges operating in different frequencies and licensing models. Wireless bridges usually work only in pairs or more, and can be used in two types of implementations. They are the point-to-point link, or the point to multipoint link.point-to-pointpoint to multipoint In point to point link, there are a pair of bridges which are used to connect two network segments, typically in two separate buildings. In a point to multipoint scenario, one bridge is installed as the "root bridge", and multiple non-root bridges connect to this root bridge. With this arrangement, if one non-root network segment wants to pass data to the other non-root segment, it passes it through the root bridge.data