in the future (and we are not foolhardy enough to predict an exact date), for
economic reasons alone in the military environment it may be necessary to break
away from existing analog signal communication network concepts in favor of all-digital
Paul Baran, On
Distributed Communications, Volume XI, 1964.
The digital media of computer
networks, by virtue of their design and the enabling technology upon which they
ride, are fundamentally different from the now dominant mass media of television,
radio, newspapers and magazines. Digital communications media are inherently capable
of being more interactive, more participatory, more egalitarian, more decentralized,
and less hierarchical. As such, the types of social relations and communities
which can be built on these media share these characteristics.
Kapor, Electronic Frontier Foundation Information, 1993.
Digital communications have the D4 advantage: "Digital
data doesn't degrade".
Analog systems and digital
systems are like mirror images of each other. Analog systems are usually controlled
by physical mechanisms that can be in an infinite number of continuous positions.
A typical example would be the bicycle, which provides force to the
wheels through the gear system depending on the continuously varying force of your feet on the pedals.
An example from the 20'th century would be one of those old record players that recorded
music with the depth and pattern of a tiny groove cut into a vinyl
disk by a diamond needle.
In contrast to approximate, analog systems, the
Internet is a digital medium based on data made up of discrete 1's and 0's. A bit of computer
data is not infinitely adjustable, and only has one of two unambiguous states
-- it is either a 1, or a 0. This limitation has a very important compensating
advantage: there is no "drift" that can introduce error.
For example, for
many years radio stations that broadcast on the AM frequency had a
lot of static because their signal was based on an analog measurement of radio
waves that were distorted in transmission. However, FM radio stations used a different method based on the
phase of the radio wave frequency, which was a digital
measurement with only one of a small number of different values, and therefore provided
static free sound that wasn't distorted in transmission. On the other hand, once
you got far enough away, and the FM receiver started having trouble decoding the
weakening signal, then the station would often just drop out altogether.
Internet, like all computer systems, is based on digital data, so that information
never changes or becomes distorted over time or in transmission between sites.
This is the key feature that makes it possible to construct the very complex
systems that run the Internet, so that a website doesn't age and become fuzzy
or garbled over time, and the characters in an email don't
get transposed or mixed
they are sent over long distances.
One of the most important strengths of
the Internet is that it's based on one of the simplest concepts -- digital 1's