Categories: wireless

How Does a Wireless Access Point Work?

Wireless networks have been available for quite a number of years now, and prior to their introduction the only option available for Local Area Networks was through the use of copper, twisted pair cabling. A Wireless Access Point is used in a Wi-Fi network as a central hub, to allow wireless client devices to connect through to a wired network. The WAP authenticates wireless clients and then relays data between other wireless clients and also devices on the wired network. A Wireless Access Point will often be connected through a router or switch to make the connection or interface with the wired network.

Wi-Fi networks support the IEEE 802.11 standard for passing data traffic using radio frequencies as the physical medium, within allotted frequency bands. Such networks are often referred to as a WLAN, which stands for Wireless LAN because of the localized area in which the wireless network operates. Some WLANs can operate without the need to use a WAP in a peer-to-peer configuration which is termed an “ad hoc” network, but these are inefficient and problematic.

Some of the early Wireless Access Points only supported a few clients (typically 10-30), but most modern WAPs support up to 254 wireless clients using a whole Class C network range or sub network of a larger Class A or Class B range. Most Broadband routers and gateways designed for the home user now have wireless as an option to wired connection. These routers effectively have a built-in wireless access point and DHCP Server for automatic allocation of IP Addresses. The SSID (Service Set Identifier) is normally configurable and is used to identify your wireless network from other networks in range. Most wireless clients in Desktop or Notebook computers will often use Microsoft’s Wireless Zero Configuration to find all available wireless networks and allow a user to connect to a preferred Wi-Fi network.

In a corporate environment, several Wireless Access Points may be used to allow hundreds or thousands of clients to connect to the corporate network through the wireless environment. Each WAP will need a wired connection to the LAN and WAPs are normally positioned so as the wireless signals overlap, allowing clients to have mobility and roam between different Access Points. To ensure full coverage within a large area, a wireless site survey will need to be conducted to ensure each WAP is positioned in an optimum location to ensure total coverage. You can look at it a bit like the Cellular system used within our mobile phone networks.

Whether you are setting up a WAP for a home network or corporate network then security should be a big consideration. Wireless networks work by sharing the frequency space amongst all clients in a similar fashion to a wired LAN. Instead of using CSMA/CD, WLANs use CSMA/CA (Carrier Sensed Multiple Access with Collision Avoidance. The fact that it is a shared environment and that the radio signals are propagated within an area means that any wireless client within range can detect and connect to that network. A number of security standards have been developed for use with Wireless Networks and WAPs over recent years.

Authentication and Encryption are the key to securing a WLAN via a Wireless Access Point. One of the first standards was known as WEP (Wired Equivalent Privacy) which used either a 64-bit or 128-bit encryption key and provided limited security. This was often sufficient for most home WLANs but certainly not strong enough for the corporate environment. Along came WPA (Wi-Fi Protected Access) and then WPA2 which used much stronger encryption algorithms and IEEE 802.11i specifies the use of WPA2.

If you are setting up a Wireless Access Point to create a home network, or using a Wireless Router with built in WAP, then configure a unique SSID that will identify your network and check which security standards are supported and select the most secure. For example, if your device supports WEP 64-bit, WEP 128-bit WPA and WPA2 or WPA with PSK then implement WPA2.

Leave a Reply