RM4 HF Data Modem

RM4 HF Data Modem with 2G ALE for Naval and Military Communications

Suitable for long distance point-to-point data links, the RM4 provides high data rates and ALE controls for high frequency data communications for naval and military missions. Embedded in the RM4 unit, the 2nd Generation Automatic Link Establishment (2G ALE) Controller is activated with the appropriate AT Comms license key. 

Features

• High Data Rate HF Modem and ALE controller in one unit
• Up to 9600 bps in 3kHz
• MIL-STD-188-141B App. A
• MIL-STD-188-110 A/B
• STANAG 4539 (QAM)
• STANAG 4285 (PSK)
• STANAG 4529 (NB PSK)
• STANAG 4415 (ROBUS)
• STANAG 4481 (P/FSK)
• STANAG 5065 (MSK)
• STANAG 5066 compliant interface (RC66 Combat Communications Suite)
• Synchronous DTE port for high grade cryptographic equipment
• Ethernet interface

Robust Waveforms 

Adaptive equalization mitigates the effects of HF channel multi-path. Convolutional encoding combined with soft-decision Viterbi decoding provides forward error correction. Cancellation of narrowband co-channel interference is accomplished via adaptive tone excision capable of eliminating up to four signals.
 
The RM4 offers customizable waveforms via a software pack option (see the reverse page for more details) 

Encryption for Security 

Encrypted data is routed through a crypto unit into the synchronous DTE port of the RM4. The modem Tx and Rx audio signals are fed to the HF radio. The radio is keyed by the RM4, while the unit monitors independent PTT activity on the radio. 

Remote Control 

The unit is fully controllable via RIPC/RAP1 remote control protocol (available from AT Comms). The unit supports split-site operation via two radio control ports.

Secure System Configuration with RM4 Unit

RM4 Unit front panel