What it is

Wireless networking in a number of different forms has been around for many years - the first wireless network was implemented in Australia in the 1980s. Wireless networking covers a wide range of technologies including infrared, microwave, packet radio, BlueTooth and what we commonly call WiFi which is the most affordable and common amongst business and home users today.

In 1997, the IEEE 802.11 standard was ratified.  This is the basis for the current wireless networking technologies that we see today.  There are three main standards in use today for consumer wireless networking known as 802.11a, 802.11b and 802.11g. These wireless (WiFi) standards operate in the 2.4 GHz ISM (Industrial, Scientific and Medical) frequency band (802.11b and 802.11g) and the 5.0 GHz UNII (Unlicensed National Information Infrastructure) frequency band (802.11a).  As with any radio frequency devices, the higher the frequency the shorter the useful distance because of absorption of the signal by things such as walls, floors, trees and other physical objects.  Thus, 802.11a has a shorter effective range than 802.11b and 802.11g.

Now, not only do your wireless networks operate in these frequency bands, but so do your cordless telephones, microwaves, garage door openers, baby monitors and all other sorts of wireless devices. WiFi uses a technique known as DSSS (Direct Sequence Spread Spectrum) to help limit the interference from these other devices, allowing WiFi to operate effectively when some of these devices are present.  Of course, if the particular frequency band is heavily used, the likelihood of receiving a strong and useful WiFi signal is reduced.


What you need

Your computer (or other device such as a printer, media player or PDA) needs to have a WiFi network card that supports the 802.11a, 802.11b and/or 802.11g standard(s). You also need to have something else to connect to - either another device (known as Ad Hoc mode), or preferably an access point (known as Infrastructure mode). Allowing devices to connect together in Ad Hoc mode without an access point is fraught with danger. More on this in a later article on Wii security.

Some network cards and access points can support multiple standards - 802.11b/g or 802.11a/b/g. There are also some not-quite-standards (such as SuperG) and emerging standards (such as 802.11n and UWB) that are available now (or soon will be).


What you get

Wireless networking gives you freedom to roam around the area covered by your access point(s) without losing connectivity. Generally, the further away from the access point (AP) you are the weaker and slower the signal. Walls, floors, filing cabinets and other physical objects will also degrade the signal strength, so you may need multiple APs to cover a particular area. This is where things start getting tricky as there are a number of things that need to be considered to make this work reliably.

If you have a large area that cannot be covered by a single Access Point, you need to establish a "mesh" which is where you configure multiple APs to cover the area, with each AP operating on a non-overlapping channel.  With 802.11a this is easy as no channels overlap each other, but with 802.11b and 802.11g there are only a few non-overlapping channels and this is where the configuration of your WLAN (Wireless LAN) becomes complicated.

Wireless networking also allows you to bring your laptop home from work and connect to your home network without having to fumble for cables. It obviously allows you to take it back to work and connect back to the work network without needing to find that pesky blue cable.  If you have something acting as a DHCP Server on each network, this is even easier.  Usually your Windows Server (at work) or your firewall/DSL Modem (at home) will act as the DHCP Server for your network.


What others get

Well, if you are not careful, they also get the ability to connect to your network. Both at home and at the office. And this is generally something that you don't want to have happen.  If you are not sharing directories and if you have secure passphrases then these hackers may only gain Internet access, but this is still something you don't want as they can launch attacks on remote networks from your network and you will have a fair bit of explaining to do when this is traced back to you.

Securing your WiFi network is something that will be covered in a future newsletter article, however let me say this for now - the majority of WLANs (wireless local area networks) out there are insufficiently secured. This is particularly applicable to those with sensitive data on their networks. And that is everyone of us.

There's no need to feel alone if you have an insecure WLAN.  A recent report (3rd May, 2005) showed that 13/24 US Government agencies don't require their WLANs to be configured in a secure manner.  Add to this the number of Australian Government departments that have insecure wireless networks and you can feel comfortable knowing you are in good company.

If you are considering wireless networking, please contact Quark IT to discuss your wireless networking and security options.