Buying a device with wireless networking
Whether your PCs have wireless already or you plan to add this later, a wireless access point will save you time and money if you want to share your network connection this way. If the wireless router has an integrated ADSL modem, it can only be used to share an ADSL connection.
Three things to be particularly aware of when going wireless are signal strength, speed and security. Most domestic devices have a limited range, especially when one or more brick walls separate the computers from the router. Because of this, in larger properties it may be beneficial to use a separate wireless access point, rather than one that is integrated into an ADSL modem/router. This is because you can determine the best location for the access point by trial and error, without having to worry about the availability of a telephone outlet. A device that uses a separate ADSL modem won't face this challenge, but you will still need to run a cable from the device to the modem.
When it comes to wireless speed, there are four technologies worth considering. All share the name "802.11" but are differentiated by their operating frequency, throughput, data rate and range (indoor/outdoor). "802.11" is a wireless standard developed by the IEEE LAN/MAN Standards Committee and then adopted by device manufacturers. They are often referred to as IEEE 802.11. For the average consumer, the most important attributes to consider when purchasing a wireless networking device are indoor range and maximum data rate.
802.11a (Wireless-A) operates at 54Mbps maximum data rate and a range of approximately 35 metres. 802.11b (Wireless-B) can reach 38 metres but only has a maximum data rate of 11Mbps. The far superior 802.11g (Wireless-G) offers a maximum data rate of 54Mbps and can reach up to 38 metres.
The latest type of wireless is called 802.11n (Wireless-N). It is still under development but many wireless devices are already available that utilise it. In its current form it can operate at maximum data rate of 248MBps with a range of 70 metres.
Wireless-G and Wireless-N are both below the speed of conventional wired networking, but are still much faster than most ADSL connections. Wireless-G is suitable in the average home for connecting multiple computers to the Internet. However, wireless streaming over a/b or g networks can be problematic depending on the number of walls between the router and the destination device. Wireless-N is far more powerful and will suit larger homes or those with higher than normal levels of interference. Wireless-N is also more suitable for gaming or media streaming as it is more reliable due to its larger range and data rate. Some proprietary systems are available that offer a rate of 108Mbps, but be sure to get a router and wireless cards for all your computers from the same vendor, or else they will default to a slower connection.
802.11g and 802.11n include the newer WPA security model to secure your connection against neighbours from piggybacking onto your Internet connection or those with more malicious intent. WEP is the older security method - you should use it if you have no alternative, however be aware that the encryption scheme has been cracked and tools are freely available online that can be used to rapidly break into WEP networks. The newer WPA standard is only an encryption technology, however, so it requires an authentication process between your wireless access point and the wireless computers. WPA is designed to use a RADIUS server to authenticate users, but as this is beyond the needs and means of most home and small businesses, WPA-PSK authentication is usually available as an alternative. Here the PSK stands for Pre Shared Key and it simply means that you use a password. A non-dictionary word with plenty of characters including numbers and punctuation marks is recommended unless you plan on changing it on a regular basis.