4G - Turn-on, Tune-in, No Dropout
By Niall McKay in Tokyo, Thu May 23 00:00:00 GMT 2002

Fourth Generation networks are already on the minds of those inside the industry's research labs.


In March, the International Telecommunications Union met in Queenstown, New Zealand to throw some light on the as yet undefined Forth Generation cellular standard. High time too, until then, 4 G meant different things to different people.

Some defined as the ability for devices to connect to the network via wireless LAN or so called 802.11 hot spots, others thought is was the ability roam between any network, still others thought that it would include new high speed wireless technology enabling users to download video to their mobile phones. In the US the confusion loomed even larger, as some operators saw it as an opportunity and started calling 2.5G Third Generation and 3G Fourth Generation.

"Forth Generation is not yet a global standard but more of a concept that will enable devices switch between different types of networks," says Dr. Johan Montelius, senior analyst with the Zelos Group. "And I am not sure that the carriers want it to be anything more than a concept. They would be much happier to wait 15 years while 3G pays for itself."

Convergence


So let us start with what 4G could achieve from the application point of view. 1st Generation enabled analogue voice and no data, and 2nd Generation enabled digital voice and some data and 3rd Generation will enable digital voice and high-speed data, 4th Generation should enable IP based voice and multimedia data. Now some would say that 3G should fulfill this vision but try running full motion video over a 384 Kilobits per second connection - that is if you could find one. As for voice over Internet protocol, well, that signal got dropped somewhere along the way. At the meeting in New Zealand the ITU's Working Party 8F came up with a vision statement for 4th Generation cellular. Seems they are as good an authority as any given the fact that there is as yet no standards setting organization for 4G. They recommended that 4G should include three basic areas of connectivity. Firstly, Personal Area Networking, enabling devices to connect with each other. Currently the dominant technology is Bluetooth, which enables, for example, devices such as cellular phones, PC s and home entertainment systems or monitors talk to each other.

The second level enables devices to connect to high-speed access points on the network. These are called "hot spots". Currently Wireless LAN or 892.11x is the dominant technology with connection speeds of about 10 megabits per second but by 2010 this should reach speeds of about 1Gigabit per second. The third level is cellular connectivity, which should reach connection speeds of about 30 megabits per second by 2005 and 100 megabits per second by 2010.

It's the second level of connectivity that has taken the industry by surprise, according to Montelius. "The market leaders don't want the market to move too quickly," he said. "But then the rapid deployment of 802.11 technology in Europe and the US has taken everybody by surprise."

Indeed, in many carriers have to rethink their strategy to include 802.11 if they don't they could find their networks undermined by it and lets face it why shell out wads of cash to the cellular operators when you can pop down to your local café get a high speed hook up for free? Wireless data providers could find themselves in the same position as the closed network or X.400 providers found themselves in with the introduction of the Web.

Weighing the Options


However, wireless LAN is not the only technology being incorporated into the 4G vision. The working group also includes Internet Protocol version 6 or IPv6, as this would enable voice over IP to be deployed.

The glue for all this wonderful technology is software radio. This would enable devices be they cell phones PDA's, Personal Computers or a whole range of connected devices that we have not even though of yet to scan the airwaves for the best possible method of connectivity presumably at the best price.

So, for example, your connectivity device would, if in a coffee shop in New York, tell you that this would be a good location to download the that DVD you wanted over the local 802.11 (or equivalent) network. On the road the device would reconfigure itself to logon to any one of the myriad of different and so far incompatible cellular networks. It might even use one for voice another for email data and still another for multimedia messaging depending on pricing. In short, 4th Generation should become the free love of the wireless world enabling devices to reconfigure themselves on the fly and log onto a new network. However, according to Dylan Brooks, Senior Analyst, Broadband & Wireless Jupiter Media Metrix there are significant technical challenges to overcome first. How would a communications chip reconfigure itself, for example, for each new network? Would it download the network protocols or store them locally?

Far more perplexing then the technical issues however are the new business models that will need to be developed. One has to wonder, for example, how companies such as NTT DoCoMo are going to recoup the estimated 20 billion Yen it took to build out its FOMA or 3G network.

Still DoCoMo Research Labs are aggressively pursuing the 4G vision and the company is constructing a trial 4G network based on the ITU's proposals. The system is combines variable spreading factor (VSF) and orthogonal frequency code division multiplexing (OFDM) technologies.

Government Funding


Indeed, given that Japan is leading the world in deploying high speed wireless technology it's no surprise that the this year, the Ministry of Post and Telecommunications is shelling out subsidies of over 2 billion Yen through Japan's Communications Research Laboratory and the Telecommunications Advancement Organization to develop the core technology, such as software radios, for 4G.

Meanwhile, in Europe, Nokia, Alcatel, Ericsson, and Siemens founded an organization called the Wireless World Research Forum to form a vision for 4G and to promote academic and institutional research in the area. In the US AT&T has developed a network prototype called 4G Access which combines Enhanced Data Rates for GSM Evolution or (EDGE) with wideband OFDM and Nortel is working on software radio power amplifier technology needed to make higher wireless speeds a reality. HP labs Streaming Media Research Group is working on systems for delivering multimedia content over next generation networks. In fact, in the coming year it will be hard to find a computer, communications, handset vendor who hasn't belted out a press release stating their strategic vision and thus their agenda for the technology.

And most analysts remain skeptical. "Basically, it's a case of the wireless vendors working up tomorrows menu while were still waiting for today's meal," says Jeremy Green, an analyst with Ovum.

In general, until the arrival of agreed international standard setting, like the 3GPP Fourth Generation will be little more than a wish list of technologies that didn't make it into Third Generation. Further, the usual punch up between the various competing standards is likely to occur. "There is a real danger that the carriers could find their business eroded by free or very low cost wireless LAN solutions," says Johan Montelius.

Will 4G make good business sense? Certainly, few would deny that the cellular market sector is going to have more than its fair share of economic challenges in the coming years, however, according to the ITU over in the next decade the majority of cellular traffic will change from speech oriented to multimedia communications.

Furthermore, in Europe alone, over 90 million subscribers will use mobile multimedia services, which will account for over 60 percent of the traffic. Furthermore, provide the market with small powerful devices and plenty of bandwidth and no doubt new applications will emerge. It's all very well to say that there is no market for 3G and 4G networks now, but then there was no market at all before the cellular networks arrived, either.

It's Mobile Research Week on TheFeature! Check back daily for reports, analysis and in-depth articles about the wireless research community.

Niall McKay is a freelance writer living in Tokyo, Japan. He can be reached at www.niall.org.