Ubiquitous Computing

Fifty years ago, the only computers that existed were HUGE, very expensive (many million of dollars each), didn't do very much, and only technicians were allowed to touch them.  

Now computing and IT devices are a lot smaller, cost a lot less, do a lot more, and EVERYONE can use them.  The IT concept hides the fact that all your digital devices are actually computers in one way or another.  Digital cameras, cell phones, MP3 players, TVs, DVD players, computers, etc - they ALL contain chips (microprocessors).  The same basic technology that powers your word-processor is also used in your MP3 player.  That's the reason that it's pretty simple to connect an MP3 player to your computer and copy (download) the songs that you bought on the Internet.  

Ubiquitous means "all over the place" or "common."  We have digital devices all over the place now.  We expect this ubiquity to increase substantially during the next decade.  What factors have contributed (and will contribute) to the rapid spread of computing devices?

Moore's Law

Gordon Moore, one of the founders of Intel (the biggest chip manufacturer) predicted 40 years ago that the size of transistors (the fundamental component in a chip) would get smaller and smaller at a rate of half as big every 18 months  two years (24 months)**.  This is an exponential improvement.  It drives the computer industry to improve it's products at an equivalent exponential rate.  That means things get smaller, cheaper, and more powerful at an amazing rate.

Improvements

You can carry digital devices around with you, using them all over the place.  This works because:

• Smaller - Chips, screens and other components got smaller and smaller.  A TFT display must be quite small to fit on the back of a digital camera.  Making displays smaller requires the pixels to be closer together than on a big flat-screen monitor, requiring more sophisticated technology.
• More Powerful - Since everything is smaller, we can fit more and more chips into the same space as before.  So a new digital camera can have more chips in it, so it can achieve much better results and have lots more features..
• Cheaper - If you are satisfied with the same desktop PC that you had 5 years ago, you can get it a lot cheaper now.  That's because the same features that required 8 chips back then probably fit into one chip now.

The big gain in size, power, and price are best described as integration.  We can

• put more and more bits together into the same package, creating a more powerful device.  Then we can make a digital camera that also makes videos (they didn't do that 5 years ago.)
  - OR -
• use fewer chips each with more features to create the same device.  Since fewer chips (and fewer circuit boards) are required, the device can be made and sold a lot cheaper.  This accounts for the ever decreasing prices of DVD players.
  - OR -
• Make the same device but make it a lot smaller.  This results in small notebook computers that can do as much or more than a big desktop computer did 5 years ago.

Portable Devices

One way to gain ubiquity (wide spread availability) of technology is with portable devices that you carry around with you.  Cell phones allow you to make and receive phone calls wherever you are - no need to find a normal telephone.  Pocket computers can be used to check e-mail anywhere - no need to find a PC.  But cell phones and pocket PCs require some new technologies that support portable use:

• Wireless connections - cell phones and wireless network connections use radio waves to carry information, whereas normal telephones and networks uses wires to make connections.
• Batteries - portable devices depend on batteries for power (more below)
• Smaller size - portable devices don't make much sense if they are too big - every reduction in size makes the devices more convenient and more popular.

Wireless (Radio waves)

Wireless connections are popular because they are convenient, but they do bring some problems. Incompatible standards may prevent a cell phone from working in another country, or might not permit your notebook computer to connect properly to a local "hot spot" (wireless network connection).

Batteries

Batteries need to be recharged, and most devices don't manage more than a few hours without recharging (say 50 hours for a cell phone, 5 hours for digital camera, 2 hours for a notebook PC).  When you buy a portable device, pay attention to the type of battery:

• Alkaline - these are the "normal" throw-away batteries that cost about a Euro each.  This is the expensive way to use a digital camera.
• NiCad (Nickel Cadmium) - rechargeable but very bad for the environment.
• Ni mh (Nickel Metal Hydride) - better than NiCad, not so dangerous for the environment, last about 50% longer than NiCad.
• Li-ion (Lithium ion) - The newest and best technology.  Contains no heavy metals, so it's "environmentally friendly", recharges quickly, and gives more power in a smaller, lighter package.  But guess what - it costs about 50% more than the others.

Free Devices

The alternative to portable devices is to have lots of free devices sitting around all over the place (ubiquitous).  At our school, there are lots of PCs with network cables all over the place, just waiting to be used.  Of course, you might be unlucky and none is available.  This is the approach used with water - rather than carrying water around with us, we hope there will be some around wherever we go.  And it's usually free.  Eventually computing devices must reach this stage of ubiquity where we just make them freely available all over the place. That probably won't every happen with digital cameras.  It isn't clear why this hasn't quite happened with telephones, except that you need to have your own telephone if you want to receive a call.  But we can expect that the infrastructure will become cheaper and cheaper.  For example,  wireless network connections are free in some cities already.

** Thanks to Yuval Jacob for pointing out that 24 months is a better approximation for Moore's law.
** You can read more about Moore's law at:  http://en.wikipedia.org/wiki/Moore's_law