dave holbon
OSNN Veteran Addict
- Joined
- 26 May 2002
- Messages
- 1,014
Many years ago before the advent of the Internet a process called ”slipstreaming” was used in the old (but now) re-invented technology called “wireless” communications.
Wireless technology relied on a carrier frequency to send and receive, upon which an audio signal was superimposed. It was only a matter of stripping out the carrier frequency and what was left was in effect directly transmitted to the speakers (after some processing using filters) and amplification.
Before the advent of the digital computer an “analogue computer” was envisaged. This in concept was far more powerful than any digital machine as it could process a factor of ten to a thousand more “bits” of information per clock cycle. It used sine waves, which had (digital) steps in them; or a form of a saw-toothed wave carried by a sine wave.
The receiver still received the correct (if somewhat distorted) signal, which it processed in the normal way, throwing away using filters, what it thought was distortion. Indeed “high quality” receivers threw away all but the original signal leaving no distortion at all, well in theory. As radio works by generating a carrier signal at a certain frequency upon which the actual signal is superimposed (usually not to low) it was a relatively simple task to “slipstream” a resonant harmonic of this frequency (30 years ago) containing you own data. Even digital communications can take place in this way and at incredible speed; if you can (in effect) distort the carrier wave (or one of it’s harmonics) just enough to produce a sinusoidal wave distorted to a stepped sawtooth that the receiver can still process without error, then for every high to low trough (the carrier wave frequency) can contains two to three hundred or even hundreds of thousands of digital signals on the actual carrier (or harmonic) wave itself, then your “slipstreaming”.
This was impossible to decode though until recently as the switching frequency of the detecting and transmitting transistors had to be incredibly high (more than 16ghz) and had to accurately track the carrier wave itself, which involved switching digital ground at enormous speed. The carrier wave itself might also be slightly distorted so error checking had to be used which lost another 5ghz.
The analogue computer will be here soon which will be a factor of one thousand times faster than current machines thanks to the old radio hams “slipstreaming” technology.
Wireless technology relied on a carrier frequency to send and receive, upon which an audio signal was superimposed. It was only a matter of stripping out the carrier frequency and what was left was in effect directly transmitted to the speakers (after some processing using filters) and amplification.
Before the advent of the digital computer an “analogue computer” was envisaged. This in concept was far more powerful than any digital machine as it could process a factor of ten to a thousand more “bits” of information per clock cycle. It used sine waves, which had (digital) steps in them; or a form of a saw-toothed wave carried by a sine wave.
The receiver still received the correct (if somewhat distorted) signal, which it processed in the normal way, throwing away using filters, what it thought was distortion. Indeed “high quality” receivers threw away all but the original signal leaving no distortion at all, well in theory. As radio works by generating a carrier signal at a certain frequency upon which the actual signal is superimposed (usually not to low) it was a relatively simple task to “slipstream” a resonant harmonic of this frequency (30 years ago) containing you own data. Even digital communications can take place in this way and at incredible speed; if you can (in effect) distort the carrier wave (or one of it’s harmonics) just enough to produce a sinusoidal wave distorted to a stepped sawtooth that the receiver can still process without error, then for every high to low trough (the carrier wave frequency) can contains two to three hundred or even hundreds of thousands of digital signals on the actual carrier (or harmonic) wave itself, then your “slipstreaming”.
This was impossible to decode though until recently as the switching frequency of the detecting and transmitting transistors had to be incredibly high (more than 16ghz) and had to accurately track the carrier wave itself, which involved switching digital ground at enormous speed. The carrier wave itself might also be slightly distorted so error checking had to be used which lost another 5ghz.
The analogue computer will be here soon which will be a factor of one thousand times faster than current machines thanks to the old radio hams “slipstreaming” technology.
