Inside IT: news
Home networks could soon run significantly faster than some business broadband connections. Peter Judge reports
Thursday January 20, 2005
In the next two years, many offices will put in wireless networks, and users with laptops will be able to work where and how they please. But workers will get a surprise when they take those laptops home: they will have much faster connections in their living rooms, thanks to new wireless technology.
The problem with wireless has been its unpredictability. Signals bounce off some obstacles, and are distorted by others, creating confusion. Now a smart antenna technology is going to turn these echoes to advantage. Mimo (multiple-input-multiple-output) systems have more than one antenna, and clever signal processing. They can separate those reflected signals and use them to set up more than one channel between sender and receiver.
Mimo can double the capacity of a wireless network, and create a more stable connection. It also makes the network go further. Perhaps the most surprising thing about Mimo is that you don't have to throw out what you already have to get the benefit.
You can easily add Mimo cards to existing laptops. But even if you don't, your Mimo access point will work with laptops that support the widespread wireless standards, 802.11b and 802.11g, and, most surprisingly, tests have found that the Mimo access point will even boost the speed and range you get with an 802.11b or 802.11g laptop.
The main makers of consumer wireless kit have jumped on Mimo. Belkin has a £100 router, and a laptop network card, which work reliably at 40Mbps, compared with about 20Mbps for 802.11g wireless. Linksys also has a Mimo base station, and Netgear has promised one this month. D-Link is waiting for the next generation of Mimo chips, but it will not be far behind.
So, will office networks get in on the act? Probably not. Office wireless Lans (local area networks) are still catching up with 802.11g, and most use 802.11b, which has a throughput of around 5Mbps. Office users probably won't have Mimo networks until around 2007.
It will be one of the biggest paradoxes in technology. Home networks will run at nearly 100 times the speed of the broadband connection they are sharing, while office wireless networks, which have a big connection to the internet, will be much slower.
The reason is that home routers with wireless Lans are cheap and simple. The "Wi-Fi" brand is trustworthy, and the technology is mature. Most laptops now have Wi-Fi built in, so you can "unplug" and go.
Office wireless networks are much more complex, and expensive, and IT managers are only just starting to trust wireless and see the benefits.
Office networks often involve more than one access point and lots of users on laptops; they carry critical information, and they need to be reliable. IT managers already have Ethernet networks that work, and don't want new headaches.
Things are changing, however, according to market research company Dell'Oro. "IT managers spent about $200m [£107m] on wireless Lans in the last quarter of 2004," said Dell'Oro analyst Greg Collins. "It finally overtook the consumer sector." But while IT managers may be spending more money, they are getting fewer networks: consumers got at least 10 times as many network access points for their money.
One sign that office wireless will grow faster is a move by networking giant Cisco: last week, it bought the leading office wireless start-up company, Airespace, for $450m.
Airespace, and rivals such as Trapeze and Aruba, offer clever centralised management technology, and advanced security for office networks. But none has Mimo.
Why not? For one thing, office users don't seem to need the bandwidth. "If customers needed more bandwidth, they would be running 802.11a," says Michael Coci, director of technical marketing at Trapeze. Another Wi-Fi alternative, 802.11a, gives more channels and better signals, but is rarely used. "I think [this] indicates customers have not yet hit the performance ceiling."
There are also no standards for Mimo. Consumers can buy what they like (it's only an access point and a plug-in card), but most IT managers won't move without standards. A non-standard system for hundreds of users could be an expensive dead end.
The world gets its wireless Lan standards from the 802.11 working group of the IEEE (the US Institute of Electrical and Electronics Engineers). The group is one of the most active and efficient standards makers ever, but it still takes time to create and agree on a formal standard.
Mimo will be the basis of a new faster wireless standard, 802.11n, which is not expected to be completed until 2006. There are two front-runners from industry consortia. The WWise (worldwide spectral efficiency) group is aiming for 135Mbps with two antennas, and an option of up to 540Mbps with four. The TGnSync group - which includes Intel and wireless chip specialist Atheros - wants to provide 243Mbps with two antennas and up to 600Mbps with four.
Also, speed is not enough. "Enterprise chipset vendors haven't produced a Mimo chip that supports enterprise features," says Coci. Businesses need features such as higher security and the ability to run multiple wireless Lans in the same space.
"I see 802.11g to 802.11n/Mimo as a replay of the move from Ethernet to Fast Ethernet to Gigabit Ethernet," says Coci. "There must be a business case for the upgrade - perhaps a new application like video telephony - before customers can justify paying the premium that Mimo will have for the first year or two."
For consumers, it's different, but Mimo may bring problems at home, warns Coci. "We are starting to see channel conflict with consumer products. Imagine what doubling the coverage area will do to interference issues."
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