In order to create a WLAN, a few basic components are required, which include the following;
1.The wireless client devices; equipped with a wireless Network Interface Card (wireless NIC)
2.The Access Points (AP) or control module
3.The wired LAN backbone
THE WIRELESS CLIENT DEVICES
This simply refers to users’ devices such as desktop computer systems, laptop computers and mobile gadgets like the Personal Digital Assistants (PDAs) and smart phones. They have embedded wireless Network Interface Card (wireless NICs) which enables users to have access to the wireless network. The wireless NIC is a hardware device that connects a computer to a network so as to send and receive data. A wireless NIC has an antenna, either internal or external, while a wired NIC has a port (usually an RJ-45 port for cable connection). The cable connects the NIC to the network, thus establishing a link between the computer and the network. A wireless NIC performs same functions as the wired NIC but one major exception – there is no port for cable connection, rather an antenna is used to send and receive data in form of Radio Frequency (RF) signals. When a wireless NIC transmits, it specifically performs the following functions;
i. Changes the computer data from parallel to serial transmission
ii. Divides the data into packets (small blocks of data) and attach the sending and receiving computers’ addresses
iii. Determine when to send
iv. Transmit the packet
THE ACCESS POINTS (AP)
As the name implies, an Access Point (AP) provides WLAN clients with a point of access into the wired backbone. It performs two basic functions; i. First, it acts as the wireless communication base station for the wireless network. All the devices that has a wireless NIC transmits to the AP, which in turn re-directs the signal to other wireless devices. ii. Secondly, the AP acts as a bridge between the wireless and the wired networks. The AP can be connected to the wired LAN by a network cable, allowing the wireless device to access the wired network (e.g. to access a file server on the LAN through it).
THE LAN BACKBONE
This is the component of the WLAN which serves as a backbone connection to the wireless AP and clients. It usually provides access to servers and the Internet.
Source: Ezine Articles – Ossy Tony