Speed vs range
Writing a column like this attracts lots of questions from both friends and readers, such as: “What’s the best smartphone?” and “Which wireless router should I buy?”. Advising on phones is difficult, since all have different strengths and weaknesses, and each one may be perfect for someone, somewhere. I just point out their relative merits then let people decide for themselves. With wireless routers, things are a bit easier because people just need something that works reliably, with good speed and range and some protection from internet nasties. There’s still one big problem, though – sheer numbers. Walk into any large retailer such as PC World and you’ll find a whole aisle of wireless networking devices, about 60 of them designed to be plugged into the end of a broadband connection.
How do you choose?
To start with, divide that range in half: half of the devices (usually described as wireless modems) are for ADSL and plug directly into a phone socket, while the other half just have an Ethernet port and are for connecting to cable modems like those supplied by Virgin Media. Confusingly, its the latter devices that are usually described as “wireless routers”, which applies equally to ADSL devices. Even once you’ve split the range in half this way, you’ll probably still be scratching your head over 30-odd choices.
There are devices on offer from many manufacturers, most of which have three or four different ranges, typically differentiated by speed. Bigger numbers look more exciting, but if you only have a simple home network and don’t copy much data between your PCs, don’t worry too much about large numbers. The limiting factor when you’re checking email or browsing the web is the speed of your broadband connection, and as long as you buy something that will run at 802.11g speeds your wireless should be more than fast enough to keep up with that. It’s also important not to be seduced by various turbo modes, G+, SuperG or talk of 108Mb/sec, unless your laptop specifically supports these speed-boosting techniques. It’s pretty rare to find laptops that do, most having simple B+G cards, although if you bought yours within the past two or three months there’s a chance it also supports draft-n.
Most users should ignore speed for the more important measurement of range. Few of us live in open-plan houses or offices with line-of-sight to the wireless router; usually there’ll be walls, floors, ceilings and furniture in the way to degrade the signal. One of the most absorbent obstacles for Wi-Fi signals is water, so don’t place your router next to a fish tank or on the other side of a steamy bathroom.
To digress for a moment, a few years ago an ISP decided to offer Wi-Fi based broadband here in Brighton and shoved a big antenna on top of the highest block of flats in town, then signed up lots of corporate customers by offering a slightly cheaper alternative to conventional leased lines. It launched the service in the spring and it worked well for a few months, but come autumn the fog rolled in off the sea. Water droplets absorbed the Wi-Fi signal and made the service totally unusable, often for days on end, and those corporate customers weren’t best pleased. This is all obvious when you think about it, since Wi-Fi (apart from 802.11a) employs 2.4GHz signals in the same band used by microwave ovens, and that frequency was chosen for ovens because it excites water molecules and causes them to absorb energy (although it isn’t the resonant frequency of water as commonly claimed). If only the ISP had thought about that before setting up shop at the seaside…