What is information? A
measure of how surprised you are
What is a channel? Something
which corrupts your information and makes the recipient have to guess exactly
what the surprise is
What is a medium Electro/optic:
Wires
100kHz
Coax
1GHz
Waveguide
100GHz
Fiber optics
1000THz
in increasing order of ``capacity''
Neat idea: Load a truck with tapes and drive it from point A to point
B. Divide the number of bits by the time taken to deliver the tapes. This
is a high speed communication channel too! (though essentially useless)
What is corruption? (did you ever think you'd have to LEARN what corruption
is?)
Noise! Also multipath issues raise their ugly heads! (ghosts on your
TV, echos on your phone line). FADING! Storage Channel: tape irregularities
(bouncing tape heads make hiss), spontaneous damage (gamma rays, heat,
etc.)
PUNCHLINE:
Any communication medium suffers from ``impairments'' such as multipath,
attenuation, noise, etc.
What you use depends on the situation
We need a methodology which can handle everything - otherwise we chase
perpetual motion