What is pervasive computing? It all started in 1991 when Mark Weiser envisioned the next generation computer that weaves themselves into their environment. The next generation computers make themselves invisible and intuitive to use. Computers disappear into the background. If you're a Star Trek fan, think of the computers in this science fiction series, and you'll get the idea.



The term coined by Weiser, ubiquitous computing, is now synonymous to pervasive computing.

Computers as they exist today do not integrate themselves into our environment. You're aware of the fact that you're using a computer. The PC sits on top of your desk. You carry a laptop or pocket PC around. You need to acquire certain skills in order to use them, e.g. if you want to use a spreadsheet, you have to learn to use it.

Weiser envisioned an environment where computers are integrated into the environment in such a way that users are not even aware of the computers, or that they're using one. The computers disappear and become unobtrusive.

To illustrate the point, Weiser and his colleagues invented 3 types of devices: a tab, a pad and a board. The devices have no individualized association in they way that you associate a PC or laptop to a particular user, e.g. you can grab a tab and use it without having to figure out how you're going to configure or personalize it to your needs. A tab is a handheld device and can be easily carried around. You can use it to access your email, chat, or to pop up a reminder for you to ask a colleague to confirm next week's seminar if you run into him in the hallway. You'd have dozens of this in your environment.

A pad is kind of a digital version of a paper. You can spread it on your desk in the same way you spread papers on your desk.

The digital board replaces today's whiteboard. When a group of people gather in a room, the system detects that they belong to a project group and automatically downloads the previous discussion points on the board. You can write on the board using a digital pen while sitting a few meters away from it - just point and write.

Pervasive computing integrates computers and a smart environment, and blends them into the background. This technology is changing the way we work, live, and interact with each other.

Let's look at a few more examples of applications of this technology.

Cowboys on horsebacks herding cattle might one day become a feature of a bygone era as the introduction of virtual fences allows farmers to herd their cattle from the comfort of their homes. The virtual fence is downloaded to the cows by transmitting GPS coordinates to head-collars worn by the cows. The dynamic virtual fences are moved along desired trajectories. The collars are equipped with a Wi-Fi networking card, a Zaurus PDA, an eTrex GPS unit and a loudspeaker that transmits occurring sounds (for example, roaring tigers, barking dogs) when a cow strays from the intended path. This multi-disciplinary project, the brain child of a biologist, is made possible in collaboration with computer scientists.

Sensor technology can potentially play an important role in search and rescue operations by first responders, i.e. emergency personnel, such as firemen, paramedic, and police, who arrive at the scene immediately after an event (e.g. a fire, an earthquake, a building collapse) occurs.

Firemen wear tags to allow easy tracking of their movement in order to coordinate search and rescue operations more effectively. The firemen can be informed if a particular section of a building is found to be unstable and is about to collapse, and is directed to evacuate it immediately. A wireless vital sign monitor is attached to victims found trapped so that their condition can be monitored in order to ensure that they receive the appropriate medical attention as soon as they are rescued.

This non-invasive sensor monitors vital signs such as heart rate, oxygen saturation and serum chemistry measurements. The vital sign monitor helps the paramedic team determine which victims are in more critical conditions so that they can prioritize medical attention to more severely injured victims. The application and architecture required to support this emergency response application is being developed under the CodeBlue project at Harvard University, USA.

Wireless technology is also used in healthcare. The Arrhythmia Monitoring System (AMS) is a medical telemetry (telemedicine) system that makes use of wireless technology to monitor patients suffering from arrhythmia. Among the complications that arise from arrhythmia are the loss of regular heartbeat and subsequent loss of function, and rapid heartbeats.

AMS provides a means for healthcare professionals to continuously monitor a patient's electrical cardiac rhythms remotely even though the patient is not at the hospital. This technology allows patients to be in the comfort of their homes without jeopardizing their health. It is also useful for monitoring the heart functions of astronauts who are more susceptible to cardiac dysrhythmias when in space.

The examples illustrate the use of the technology in very different areas. There is no limit to the type of applications made possible by this technology. In the not too distant future, we will see this technology providing increased security, convenience, and ease of information access in our home and workplace.