audp 0.9

Analog Unicast Data Protocol (AUDP)

Analog Unicast Data Protocol (AUDP)

AUDP transfers analog data in a unicast manner between two TCP/IP-compliant machines.

Modems

PCM/AUDP

Encodes each bit using PCM. This results in larger, longer packets, but has practically no chance of data loss. There can be up to ~0.98 kHz of interference, and PCM/AUDP will still be able to get a clean signal.

DAC/AUDP

Encodes each byte using DAC. This results in much smaller (about 8x smaller than PCM/AUDP) packets, but the chance of data loss is slightly higher. Not to be used in highly noisy areas, where sonic data may be lost. The tolerance for DAC/AUDP is ~35 Hz.

Specifications

Each unique frame of data should be 20 ms, or 882 Hz (samples) long at the AUDP-compliant sample rate (44.1 kHz).

AUDP sonic data may be transfered in any medium, as long as the frequencies remain. For mediums that may endure compression, noise, or other forms of potential data loss, PCM/AUDP-based modems are recommended.

For PCM/AUDP-based modems:

The LOW (0) signal is represented by a frequency of 6 kHz.

The HIGH (1) signal is represented by a frequency of 4 kHz.

The END CHUNK signal is represented by a frequency of 2 kHz.

Acceptable tolerance is ± 975 Hz for any signal.

For DAC/AUDP-based modems:

The factor to mulitply the byte by is 70 Hz.

Example: byte 'A' (65, 0x41, 0b01000001)

Mulitply the decimal value of the byte (65) by the DAC factor (70 Hz) to get the frequency of 4.55 kHz.