User's Manual

SDRe Programming Software
Revision V1.0
P a g e | 60
4.6.2.3. Selecting the type of Digital Modulation
Digital Emissions on SDR repeaters can be used on three different
modes. FDMA (Frequency Domain Multiple Access), TDMA (Time
Domain Multiple Access) or Simplex mode (Transmit and receive on
the same frequency.
Press on the Digital Mode arrow to slide down the menu.
Figure 69: Digital Mode selection for Digital profile
FDMA: Transmits a single continuous 4FSK carrier @ 4800bps
using ultra narrow band (6.25 Khz Bandwidth)
TDMA: Transmits two slots over a continuous carrier of 9600 bps
using a narrowband channel (12.5Khz Bandwidth)
SIMPLEX: Similar to TDMA but the carrier is not continuous.
Repeater receives on slot 0 and transmits the same information on
slot 1, using the same frequency for TX and RX Simplex mode.
To store this option, click on any part of the tab. To save the value,
press [Ok] or [Cancel] if you want to discard the changes.
4.6.2.4. Crypto Key definition
SDR protocol improves a high security encryption for voice and data.
The encryption is encoded and decoded using a 128bits mask, which
must be defined on this tab.
Figure 70: Crypto Key for Digital Profile