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by kw71
2681 days ago
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Think back to the state of the art in the 70s when these were thought up. You can cite SIGSALY[1] but it took a really long time for these concepts to be flyable. AT&T was doing digital telephony terrestrially in the 60s [2] but radio links make this more difficult. Of course things are different today. [1] https://en.wikipedia.org/wiki/SIGSALY
[2] https://en.wikipedia.org/wiki/T-carrier |
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