Information Super-Highway? I think
not.One of the most common ways to transport data from one computer to another is to write the data onto removable media, physically transport the media to the destination machine, and read the data back in again. Often this is called "sneaker-net".
While this method is not as sophisticated or glamorous as using geosynchronous communication satellites, it is often much more cost effective, especially for applications in which high bandwidth or cost per bit transported is the key factor.
A little background data and a simple calculation will make this point clear:
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A "box of data" could be delivered anywhere in the United States within 24 hours by FedEx or such companies.
The effective bandwidth of this (using Exabyte tapes) "transmission" is 2450 gigabytes/86400 sec or 232 Mbps, which 150 times faster than a standard T1 line (1.544 mbps) and is about one third of the high-speed version of ATM (622 Mbps).
If the destination is only an hour away by road, the bandwidth is increased to over 5.5 gbps, 3,526 times faster than a T1, 8 times faster than ATM.
If we now look at cost, we get a similar picture. A "box of data" is going to be heavy. Let's say $200 for shipping, giving us a net cost of about $0.08 cents per gigabyte. At (2005) cable modem prices, uploading data costs around $0.61 per gigabyte. If the T1 were to cost $1000/month, the cost would be $2.62 per gigabyte
Consider this:
A family station wagon has at least 24 cubic feet in the back end.. That'd be 57.4 terabytes. A one hour drive would then 57.4 tb/hour and a cost of perhaps 3 gallons of gas.The moral of the story is:
Never underestimate
the bandwidth |
And why would I ever need so much data? Click here to read more.
It is at least interesting to note that a standard vinyl LP record of the '60s had higher effective data density than the magnetic tapes from 1980. You could stack 50 or so albums in a cubic foot.
Stony Smith, circa 1978, updated periodically