Securing your wireless network

Wireless local area networks (WLANs) use the same basic structure of components as the traditional Ethernet-wired networks. However, instead of cables, WLANs use infrared or radio frequency technology to transmit data around the network.

Businesses typically use wireless networks within a single building, or as a building-to-building connection, often as an extension to a wired network.

What are the main components of a wireless network?

The physical WLAN architecture is fairly simple. Basic components of WLAN are typically:

• wireless access points
• network interface cards (NICs) or client adaptors

You can use other components, such as wireless bridges and repeaters, to extend the reach of your network.

Wireless access points

A central access point is basically the wireless equivalent of a LAN hub. It is a small box (with one or more aerials) that uses a connector to attach it to the rest of your wired LAN.

Access points receive and transmit data from and to all the wireless devices in their area. They can handle many different connections between different devices all talking to each other at once, but the more devices you have working with an access point, the slower they will operate.

You may need more than one access point to cover a building, depending on its range and the composition of any walls or floors between the access point and the wireless network card.

Wireless network interface card (NIC)

The network interface card acts as the radio receiver and transmitter for a specific computer and connects it into the WLAN. It is coupled with the device operating system using a software driver. Many modern laptops or tablets have this Wi-Fi capability built-in, but with older desktop PCs you may need to install one.

Most wireless network cards connect to an access point. However, some NICs can enable a peer-to-peer connection - ie they can talk to other compatible network cards that are within its range. This may be useful for small roaming workgroups of devices that do not require access to the LAN backbone.

Wireless range extenders

Wireless repeaters can improve or extend the coverage of your network. They work by receiving your existing Wi-Fi signal and relaying your requests and responses between your device and your main Wi-Fi router/access point. With a repeater, you can effectively double the range of your WLAN.

Most WLANs are installed using access points that have omnidirectional aerials or antennae. These transmit wireless signals in all directions, as opposed to directional antennae, which produce a more concentrated signal focused on a narrower area. Depending on the type of signal you need, replacing the antenna of your wireless access point may give you a better range.

Wireless bridges enable high-speed long-range outdoor links between buildings. Their range is typically up to 25 miles. They are based on line-of-sight, so physical obstacles such as railroads or bodies of water generally do not affect them.

How to set up your WLAN?

The different components need to be compatible for the WLAN to function correctly. This is possible because they comply with a set of wireless networking standards intended to enable devices from different manufacturers to work together.