Perelivt^[a] is a proprietary communication system, used exclusively by the Russian diplomatic service.

Links are established using a single-tone 3000 Bd 8PSK waveform, based on the 3G ALE standard. Perelivt scans through 3 duplex channels in a loop, successively calling on each frequency until a timely response is received. There are 2 calling modes:

• Short: Transmits 4 PSK bursts, changes the frequency after 18 seconds
• Long: Transmits 17 PSK bursts, changes the frequency after 60 seconds

After a link is established, full duplex communication is made using one of 3 successively faster waveforms:

• 66-tone MFSK (default)
• 128-tone OFDM, 3 kHz wide
• 128-tone OFDM, 6 kHz wide

Waveform changes require the link to be re-established from scratch.

Waveforms

The signal generated by Perelivt is approximately 10 kHz wide. Note that the dial frequency is the center of the 10 kHz passband. The spectrograms shown here are to scale.

3000 Bd 8PSK

66-tone MFSK

128-tone OFDM (narrow)

128-tone OFDM (wide)

Notes

1. Perelivt is a code name created by Priyom to unambiguously refer to all four waveforms as part of a single system. Like "serdolik" (сердолик), "perelivt" (переливт) is a cryptocrystalline mineral. The actual name of the system is unknown.