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some thoughts about frame-layout:
* Old frame-format has to be revised - more info later...
* Old format supported 8 logical channels,
I would like to reduce that to 4:
* 1 Channel for control (additional control-bandwidth in frame data-zone)
* 1 Channel for audio (gsm voice-data)
* 1 Channel for sio-data (transparent user-channel via serial port)
* 1 Channel <reserved> (might be multiplexed to support a higher
number of logical channels than standard=4)
This looks ok, or what do you think ?
* Is there a public implementation of gsm half-rate compress/expand ?
* Do we operate the modem in "raw" mode (without error correction,
but in "real time" operation) ? Sure about that ???
Does this mean that we can be *absolutely sure* to be able to
transmit data at 1800 Byte/Sec (14400 Baud Modem) all the time ?
So also no "retraining sequence" (600mSec++ no data) ?
Should we add little redundancy to the frames (loosing some bandwidth) ?
Decryption trashes several sequencial bytes for one bad input-bit !
* Old frame-layout supported loosing only parts of a frame.
This meant that a one-bit-error could only trash one logical channel,
not causing you to loose a whole frame.
Is this a feature worth to be kept ?
Thats enough for today ;-)
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