WE ARE on the verge of a revolution that will bring wireless broadband to the masses. Today almost everyone who wants high-speed access to the internet relies on wires connecting them with a telephone exchange. But in about five years鈥� time all you will have to do is switch on your laptop and the web will be just a keystroke away, whether you are in the office, on a train or lazing on a beach.
Of course wireless broadband already exists, but on a very limited scale. The average indoor Wi-Fi setup has a range of less than 50 metres between transmitter and laptop. But the new technology, called WiMAX after an industry forum for Worldwide Interoperability for Microwave Access, will change all this. Laptops will be able to communicate with base stations up to 50 kilometres away.
Technology giants such as Intel, AT&T, Siemens and Alcatel are backing the fledgling technology, and last year they agreed on a common standard that they hope will see WiMAX sales take off. Industry analysts are predicting a sixfold growth in WiMAX sales over the next three years (see Graph).
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Each WiMAX provider will have a network of base stations, similar to a mobile phone network. Each base station will be able to handle a bandwidth of at least 70 megabits per second 鈥� equal to hundreds of current broadband connections via a phone line.
Most countries have regulations restricting the power of radio transmitters, partly to prevent interference with other transmitters and partly for safety. The US, for example, limits radiation from Wi-Fi antennas to 1 watt, while Europe keeps it down to 100 milliwatts. Given these restrictions, how will WiMAX achieve such a high data transmission rate over a range of 50 kilometres?
To provide high-speed net access its carrier signal will be between 2 to 11 gigahertz, but the range of such high-frequency radio signals is limited by 鈥渕ulti-path interference鈥�. Signals can bounce off buildings and these reflected signals interfere with each other. The higher the frequency of the signal the worse the interference and lower the range.
WiMAX gets round this problem by splitting the data into several low-frequency signals. For example, instead of a data stream at 100 megabits per second, WiMAX might split this into 20 data streams, each carrying five megabits per second. It transmits these signals simultaneously and reassembles them at the receiver. Because each signal is 20 times lower in frequency than the main signal, it travels further before multi-path interference erodes it. There is a price to pay, however. 鈥淵ou need much more processing energy to encode and decode the signal,鈥� says Herbert Weber, technical director of Intel鈥檚 office in Munich, Germany.
WiMAX will be introduced in two stages. Initially suppliers will concentrate on providing a wireless broadband service to homes and businesses. Early next year, you will be able to buy a modem with an external rooftop antenna that will communicate with a base station. This will put high-speed web access within the reach of the 25 per cent of households in Europe and the US who cannot get broadband because they are too far away from telephone exchanges.
But today鈥檚 WiMAX equipment is too bulky and expensive to be portable, says wireless industry analyst Edward Rerisi of ABI Research in Oyster Bay, New York. The challenge is to shrink the technology down to where it can work with laptops, and make it cheap enough.
Intel鈥檚 backing for WiMAX could do the trick. Weber says that by the end of 2006, Intel plans to have built the modem and antenna into its Centrino chipsets, which power many of today鈥檚 laptops. 鈥淐an Intel drop the price down and lower costs? The answer is definitely yes,鈥� Rerisi says.
Intel and other companies manufacture these signal-processing chips in bulk. When the WiMAX modem goes on the market next year it is expected to cost $500. But in three years鈥� time not only will the technology have shrunk, so too will the price 鈥� to less than $50, according to Rerisi.
The network of WiMAX transmitters will eventually provide a similar coverage to today鈥檚 mobile phone networks. And it will also enable people to use their laptops on the move, so they can switch from one transmitter to a neighbouring one without losing their connection. The WiMAX standards envisage continuous coverage even when people are travelling at speeds of up to 100 kilometres per hour.
Some proponents believe WiMAX could even handle telephone calls, possibly giving 3G mobile phone networks a run for their money. But not everyone is convinced. 鈥淲iMAX will surely cannibalise some revenue from 3G, but in no way, shape or form will it replace 3G,鈥� Rerisi says.
Nokia seems to agree. The company recently dropped out of the WiMAX forum that it originally supported. 鈥淲e explored the technology and didn鈥檛 see a business case big enough for us,鈥� says Seppo Aaltonen, head of Nokia鈥檚 wireless technology division in Espoo, Finland. 鈥淲iMAX is a little more hype than reality from the business point of view.鈥�
Despite Nokia鈥檚 stance, WiMAX is already under trial in many countries, including the US, UK, China and India. 鈥淗eavy data users will gravitate towards WiMAX in five years,鈥� Rerisi predicts.
