Beyond Wi-Fi - the future of wireless networks

It's the belle of the ball right now – but that's not to say it won't be superseded soon…

The standard known as 802.11b – or Wi-Fi – is disruptive, certainly if you’ve invested any time, money and effort in 3G. But, says Ben King, there is always something potentially superior around the corner. Find out what may lay beyond Wi-Fi… Few technologies are greeted with the seemingly unconditional love that's been heaped on Wi-Fi. Such is the relief that this wireless aspirin has brought to a hurting tech sector – clearly still badly hung over after 3G, dot-com and Y2K - that the many warts and drawbacks of the 802.11b standard have received relatively little attention. Only the security issues of wireless LANs have received extensive bad publicity – with numerous stories focusing on the ease of ‘drive-by hacking’. But they've mostly highlighted sloppy IT managers rather than a flawed standard. But cheap, versatile and user-friendly as 802.11b Wi-Fi is, it has many imperfections – and it may take a complete revolution in wireless networking technology to fully resolve them. At 11Mbps, an 802.11b connection hardly seems slow to anyone who has ever had to access the internet on a dial-up modem. It's still 20 times faster than vanilla ADSL and for most ordinary business tasks it’s perfectly adequate. But networks can always be faster – for video, for example. The first big difficulty with 802.11b is power consumption. Most of the devices that might want to use wireless tend to run on batteries, only Wi-Fi wasn’t designed with that in mind. In terms of getting through the battery life of a laptop, a Wi-Fi card burns it up faster than a barbeque party in a firework factory. Wi-Fi is also likely to become a victim of its own success. Wi-Fi only operates on three channels. This means if there are several networks operating in the same area, which will increasingly be the case, there is a risk that they will start to interfere with each other. The 2.4 GHz area of the spectrum is also fairly crowded, with mobile phones, Bluetooth devices and others possible sources of interference which can be as mundane as microwave ovens, though this user has been running a domestic 802.11b WLAN for nearly a year without a suggestion of interference. Not surprisingly, numerous tweaks to the 802.11b standard are on the way. Some of them are proprietary, which means they don't work with other vendor's equipment, like Texas Instruments’ Turbo Wi-Fi, which is twice as fast as 802.11b, and already on sale. The other two are official standards of the Institute of Electronic and Electrical Engineers (IEEE), those implacable enemies of the catchy brand name, who have dubbed them 802.11a and 802.11g. Both offer increased data speeds – 54Mbps maximum in both cases, though whether any user will actually get that or need that is a moot point. 802.11a offers extra channels – usually eight, though it may be possible to deploy networks with more. It uses the less crowded area of spectrum at 5.2GHz, which means less interference. 802.11g uses the same band as b, cramming more data into the same three channels, but it doesn't have the network density advantages of a. It's meant to be backwards-compatible with b but there are question marks over whether that really works yet. g isn't yet ratified by the IEEE as an official standard and any equipment currently shipping is under a draft standard, meaning compatibility and reliability issues are likely to continue to arise as the standard settles down and manufacturers get the hang of the new products. Meanwhile, neither has quite resolved the power issue, says Frost and Sullivan analyst Michael Wall. "Generally, the more data you send the more power you need. a and g both consume more power than b. They are working on improvements but they are both quite power-draining technologies," he said. Though tech companies rarely pass up a chance for a holy war, the duel between a and g isn't likely to rank among the industry's classic standards ding-dongs. Most vendors seem to be keeping a foot in both camps, bringing out products based on both and waiting to see which will fly. NetGear, for example, is shipping both a and g kit. 802.11a and g will appeal to users in very crowded locations. The extra bandwidth could also be useful for running cast-iron encryption. But few companies are likely to deploy either without building in 802.11b compatibility, certainly not in public locations, given the estimated 17 million 802.11b-enabled laptops and handhelds coming on to the market. Vendors such as Cisco and D-Link are increasingly shipping base stations and cards that are capable of two standards. As volumes increase and production costs fall, dual or tri-standard base stations will be cheaper to build and become increasingly widespread. One of the few apps that will really need that extra bandwidth is video but good quality videoconferencing requires more than just a fat pipe - it needs guaranteed availability or quality of service. The IEEE is working on another standard with the characteristically inventive moniker of 802.11e but this is still under discussion in the institute's notoriously fractious committees, so don't look for products on the shelf any time soon. With 802.11a not expected to mature until 2004 at the earliest, its window of opportunity is pretty small. A new kind of radio network, and one of the few new technologies that is genuinely revolutionary, is emerging to challenge it. Instead of sending data out over a very small part of the spectrum, ultra wideband (UWB) sends out a signal over a much wider area. UWB connections with over 500Mbps have been demonstrated and manufacturers predict that over 1Gbps may be possible. That’s enough to download entire movies in minutes. "UWB is particularly good at using multiple channels in the same space," says Mark Moore, founder and CTO of Artimi, a Cambridge-based start-up which is designing chipsets for UWB-based wireless networking products. "You don't slow down as you add devices to the network." Research from Intel suggests UWB transmits 1,000 times more data in a given area than 802.11b and 12 times as much as 802.11a. The same research suggests a power drain 100 times lower than an equivalent service based on Bluetooth – and Bluetooth is far more power efficient than 802.11 flavours. UWB was approved for communication purposes in the US in February 2002 and devices are expected on the market in the US before the end of 2003. In Europe the regulators are still wrestling with the problem but it's expected to receive approval before the end of this year, with products coming on to the market next year. "The thing that is holding it back at the moment is regulation," says Steve Plimmer, principal engineer at communications specialists Mason Consulting. "There is a massive demand already and we predict there could be 200 million devices out there by 2005. There could well be a couple of devices per household across the UK." If that’s the case – and it will depend on a number of factors – then the disruptive technology that is Wi-Fi will have suffered its fair share of disruption as well.