A Wireless Local Area Network (WLAN) is the term used for the network used to connect one or more computers directly, or using a router as an intermediate, either to share data between each other (thus forming an Intranet system), or to connect to the Internet by making use of the services of an Internet Service Provider (ISP).
Almost all modern WLAN systems use the IEEE 802.11 standard, more commonly known by its brand name, Wi-Fi. The architecture and particular types of WLAN system available are described in the sections below:
Any device capable of connecting to the WLAN are referred to as stations, and access the network by means of their wireless network interface controllers. Stations can be classified into either access points or clients. The most commonly recognised access point is a wireless router, which is capable of allowing multiple clients (the portable devices which access the network) to connect to the WLAN, and can also control their level of access to a network or to the Internet. Stations accessing the WLAN can be grouped into service sets. The Basic Service Set (BSS) defines the set of stations which can communicate directly with each other, and each BSS is defined by an identification tag known as a BSSID. The Extended Service Set (ESS) defines a group of connected BSS networks, and each ESS is defined by a tag known as an SSID. The distribution is the method by which each of the members of an ESS can communicate.
Types of WLAN
A peer-to-peer (P2P) network involves direct communication between computers using the Independent Basic Service Set (IBSS) protocol, without making use of wireless access points.
A wireless distribution system allows the access points of a standard network to be connected, and therefore allows the expansion of a network using wireless communication methods rather than a physical Ethernet cable linking each of the access points.