Lab

Wireless routers

If you don't already have a wireless network, it's about time you did. And if you've had one for years, you should seriously consider upgrading it with a new 802.11n router. This latest WiFi standard offers higher speeds and better range than ever before.

The main reason to create a wireless network is so that you can use your broadband connection from anywhere in the house. That's useful even if you only have one PC, especially if it's a laptop, and means that when friends bring their laptops round you can let them can access the Internet too. If you have several PCs, as many of us do these days, the benefits are even greater. As well as being able to use the Internet on all of them at once, you can easily transfer files between them and access printers and storage over the network.

Most laptops now come with WiFi, and any computer (as long as it's not donkey's years old) can have a wireless adaptor added, usually as a USB dongle. This gives you the ability to network everything quickly without having to run cables. The Sony PS3 and Nintendo Wii games consoles both have WiFi built in, and a wireless adaptor is available for the Xbox 360. There are lots of other network devices available, too, including media streamers that let you play music, videos and photos from your PC on other devices.

Adding a wireless router to your broadband connection also makes it more secure, as the router will incorporate a firewall. A firewall acts a bit like a border crossing guard, checking the ID of anyone who wants to enter and ensuring the bad guys can't get in. In the case of the Internet, the purpose is to check all network traffic and filter out attempts to hack your system or install malicious software. In conjunction with your PC's security software, this makes it much harder for hackers to attack your computers. And when it comes to networking your PCs together, a router avoids traditional hassles like assigning IP addresses; it's all handled automatically for you.

The routers on test here are all based on the proposed 802.11n standard, known as 'Draft-n' because it's not yet officially ratified. Most should be able to be upgraded to the full standard when it appears, but regardless of this they have a lot to offer right now, including better range and more stable connections than with earlier 802.11g kit.

In theory, these units offer data transfer speeds of up to 300 megabits per second - three times faster than 100Mbit Ethernet, used by most wired networks. In practice, you won't get anywhere near that speed, and what you do get will depend on how far the PC is from the router. We tested each router with a laptop placed one metre, 15 metres and 25 metres away; bear in mind that in the real world, walls and floors will shorten range, but you should be able to replicate the 25 metre result in most parts of your house. We tested with the standard WiFi adaptor built into an Intel Centrino laptop and with a USB WiFi adaptor supplied by the same manufacturer as the router, which can often increase performance.

Routers fall into two groups: those that incorporate an ADSL modem, for use with any broadband connection that works over the phone line, and those without. If you have cable Internet, only supplied by Virgin Media (formerly NTL/Telewest) in the UK, you need a plain router, which you connect to the modem supplied by Virgin. An ADSL router replaces whatever modem you're currently using and plugs directly into the microfilter or ADSL port on your phone line. As you'd expect, plain routers generally tend to be cheaper.

Setting up your router

Wireless routers work by broadcasting radio signals that are received by suitably equipped computers and other network devices. Like any radio signal, these can be blocked or interfered with, so the position of your router is critical. The best place is mounted high up on a wall, ideally in the middle of your house. This will ensure the best overall signal. That isn't always practical, of course, so just avoid placing your router inside a cupboard or behind lots of other electrical equipment. The router will need to be close enough to your Internet access point to connect to it with a cable - this part of the network isn't wireless.

Once you've found a suitable location, you can get on with configuring your router. It'll be able to display a web page, which you access from your web browser, to choose and alter its settings. Some make initial configuration easier with a CD-based setup wizard that takes you from plugging in the cables all the way to getting a working Internet connection and wireless network.

Whichever method your router supports, a vital task is to make it secure. Wireless signals are free to leave your house, making it possible for anyone nearby to connect to your network and use your Internet connection for free. That might not sound like such a big a deal, but if they do something illegal over your connection it'll be your door the police knock on. And once someone's on your wireless network, and therefore behind the firewall, they can hack your computers more easily.

The most important step is to turn on encryption, which ensures only those people with the right password can join your network, and traffic is unreadable by anyone else. The lowest form of security is WEP. This isn't very secure - although probably more than enough for everyday purposes - and usually requires a password made up of a long string of hexadecimal characters (0 to 9 and A to F), which is hard to remember. Use WEP if you've got devices that don't support other forms of encryption. It's better to use WPA or, if available, WPA2. These are much more secure, and you can set any access password you like.

Some of the routers on test support automatic setup. Buffalo's AOSS is a proprietary technology that sends network settings to Buffalo WiFi adaptors and Centrino laptops. Push a button on the front of the router, click the software button on the PC, and that's it. A similar feature called WPS (WiFi Protected Setup) will be standard on all final 802.11n routers. But using Windows' wireless networking utility and typing in your WPA password is really just as easy.

Each network adaptor has its own unique 'MAC address' (nothing to do with Apple Macs). Most routers let you enter the MAC addresses of all your devices and prevent any others from connecting, known as Mac address filtering. It's a useful security option, especially if you have devices that make it tricky to set up encryption, but it can be a hassle to manage and won't stop determined hackers. The same goes for the option to make your network invisible by turning off its SSID (network name) broadcast. This doesn't hide it from anyone determined to find it, and makes it less convenient for you to connect. For convenient protection, WPA is the only security you need.

Testing times

A common complaint about wireless networks is that they're unreliable. That tends to be less true with newer routers and adaptors, and there are ways to minimise the problems. Double-click the network connection status monitor in the system tray at the far right of Windows XP's taskbar (or in Vista, open the Control Panel, go to Network and Sharing Center and click View status). You'll get a graph that shows wireless signal strength.If you're close to the router, this should be full; if you're far away, you may only get one bar. In most houses you should get a strong signal up to 15 metres away, and one or two bars at 25 metres.

You can test network performance by copying a file to or from another PC. To work out the speed in Mbit/sec, first right-click the file you want to copy to see its size in bytes. Multiply this figure by eight and divide it by 1,000,000 to convert it to megabits. Divide this by the time taken to copy the file, in seconds. For example, if a 100MB file (104,857,600 bytes or 839 megabits) takes 15 seconds to copy, that's a speed of 56Mbit/sec.

If you're getting a weak signal even close to the router, or you're not getting much range, there are some tricks you can try. Check the wireless settings in your router's management page. It should be set to use channel 1, 6 or 11 (others cause interference). Switch between these until you get better reception. Draft-n routers also have a mode called channel bonding, which uses two wireless channels to double throughput. This can cause issues, so look in the settings and change the mode to use a single channel: depending on your router, either the 20MHz mode or the 130Mbit/sec mode.

Ultimately, random interference or thick walls can prevent wireless from working all round your home. If you've tried everything, consider adding HomePlug adaptors, which use your mains power cables as network wiring, to extend your wireless network into those hard-to-reach spots.