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Portable Noise
The present and future of wireless
by Lynn Sutherland

There has been a lot of noise about wireless communications recently -- both literally and figuratively. We hear statements like "billions of cell phones in use," "completely connected," "anytime, anywhere, anyplace," and "ubiquitous embedded wireless devices" from every direction. But what does all this talk actually mean? What is here at our disposal right now? And what might realistically be coming our way over the next few years?

I'm going to respond to these questions first with a bit of a primer -- let's call it "Wireless 101" -- in order to demystify the jargon and lend some context to all this talk about mobile networks. Then I'll mention the three biggest trends, and a few of the major challenges, that I see influencing the near future of wireless technology.

In its broadest sense, the wireless world could be said to encompass the entire electromagnetic spectrum. But the wireless world that most of us know and use today is the cellular telephone network, riding on the invisible radio waves that vibrate between 800MHz and 3GHz. The matter of signal speed (measured in Hertz) is mostly irrelevant to this conversation, except that certain speeds are licensed (at a large cost to the communication companies, and therefore the user) and dedicated to certain purposes, while other speeds are unlicensed and available for free public use (and misuse).

The four main types of wireless systems are: the "local area network" (LAN), the "personal area network" (PAN), the satellite network, and the cellular network.

With a range extending between tens of metres and a few kilometres, the LAN is designed to cover a home or an office. These systems typically connect one or more computers wirelessly to a base station (via a Network Interface Card or NIC) which then connects the computers to the Internet. Wireless LANs are beginning to appear more frequently in businesses and residences: Apple makes a base station called the "Airport", and other vendors are now offering them as well. A base station costs about $300 (Can), while a NIC costs about $100. LAN signals are carried on a free (i.e. unlicensed) part of the electromagnetic spectrum.

A PAN, or personal area network, is designed to cover a person or a room. PANs have a range of about ten metres and, like LANs, are carried on an unlicensed part of the spectrum. These systems are usually about the size of a microchip, and are embedded in small devices like cell phones and personal digital assistants (PDA). The advantage of this technology is its low power requirement -- these systems can run on small batteries. The main standard emerging here is called Bluetooth (after a tenth-century Danish king). Several trial applications are currently being tested. Examples include: transferring data between computers and PDAs; enabling mobile phones to make vending machine purchases; and wireless headsets for telephones.

Satellite networks can cover a very large range -- hundreds of kilometres. With a higher "data rate" (measured in bits per second) than LAN or PAN systems, they can also transmit a lot more information in a given amount of time -- enough to carry even television signals. But the travel time of the signal from the satellite to the receiver antenna can be 10 to 250 milliseconds -- far too long to enable many applications, like regular two-way voice communication, or the remote control of vehicles or equipment. And, even though the antennas have become much smaller in recent years, they are still too big and expensive to use with most portable applications.

Cellular networks operate via the familiar cellular tower. These stations transmit signals in the sub-microwave range (radio waves, or RF) with a range of between one and one hundred kilometres, depending upon the amount of interference from built structures, hills and valleys, and other wireless signals. There have been several steps in the evolution of the cellular network, and several more are predicted for the near future, giving rise to the shorthand terms 1G, 2G, 2.5G, 3G, and 4G. But what do these buzzwords mean? The "G" means generation: So 1G, or "first generation", were the original analog cell phones. 2G and up are the newer digital cells. The main functional difference between generations is the data rate -- again, the information transmitted in a given period of time.

We presently live in a 2.5G world (and we will for a while). 2.5G is a bit slower than a slow home dial-up connection. 3G will be ten times faster than 2.5G, but not as fast as a typical cable or DSL connection. Although 3G was first envisioned around 1985, and many thought this generation would be operational by the year 2000, this has not come to pass. The main reason for this has been the cost to wireless network suppliers of putting the necessary equipment in place, licensing the RF spectrum (which was auctioned off to the highest bidders around the year 2000), and resolving the issue of which standard to use (not to mention the current lack of applications, and thus customers willing to pay for the service). ed: an explanatory tale for the current disarray of the Telecoms industries.

The Future
Now that the jargon has been explained, and the present state of wireless roughly defined, what about the aforementioned predictions about upcoming trends in mobile communication? What new technologies are we likely to see emerging into the mainstream over the next few years? And what might some of the implications be, in terms of how we live, communicate, and manage information?

First prediction: LANs (802.11 LANs, to be precise about the standard) will spring up everywhere, but they will require a new way of looking at the security of personal and corporate information.

Second prediction: Every Game-Boy generation kid will have a Bluetooth PDA, and they will figure out applications that we can't even imagine.

Third prediction: Applications of wireless location, tracking and monitoring of vehicles, people, inventories, and so on will spring up in cases where there is a business case for improved service or productivity, or where there is a safety issue for items or persons.

In the short-term, Bluetooth and 802.11 will enable stand-alone wireless applications, such as interactive gaming between PDAs, and wireless Web access from your favourite pub, backyard, office building or campus. Bluetooth and 802.11, because they are inexpensive and don't require massive infrastructure, will likely grow in use rapidly. 3G, 4G and satellite wireless networks require massive infrastructure investment, however, and it will take longer to cost-justify their wide deployment.

One of the biggest challenges will be getting the various technologies -- satellite, cellular, LAN and PAN -- to work with each other. These require different hardware and speak different "data languages", so their integration will require a lot of work. Another issue that needs to be better understood is what impact these ubiquitous invisible signals will have on other forms of equipment, and especially on human beings and other life.

Privacy vs. Convenience
I'll end with a scenario that demonstrates some of the potential power, and potential problems, inherent in this wireless technology wave.

Imagine a person with diabetes. In the not-too-distant future, this person might have an implanted micro insulin pump with a wireless Bluetooth connection that sends data to the person's pocket PDA. The PDA could be programmed to track the person's blood sugar levels over time, compute appropriate dosages, and send orders to the implanted micro pump to release insulin when needed. At home or at the doctor's office, the PDA might be enabled to send a few weeks-worth of recorded information to the doctor's computer via an 802.11 wireless connection. In emergencies, the PDA could broadcast basic medical and location information through a local cellular network, or through a satellite network if the person is off the beaten track.

This scenario predicts seamless autonomous support for the diabetic person, and the smooth transfer of important information to others in an office or emergency situation. But what about the security of the information? Encryption, passwords, and other privacy and security systems would slow down or even disallow some of this seamless transfer of data. What trade-offs will people be willing to make when considering the privacy of their information versus the convenience achievable through wireless communications?

The author used PriceWaterhouse Coopers' Technology Forecast 2001-2003 to verify the technical details for this article.

Lynn Sutherland is the Director of Programs for iCORE --the Alberta Informatics Circle of Research Excellence, where she funds and develops research in software engineering, wireless networks, high performance systems, and nanotechnology.

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