Link 22 Signal Processing Controller SPC 1921 Airborne.
The SPC 1921 is the airborne version of the naval SPC 1920, built by porting the SPC 1920 functionality to airborne suitable hardware. The SPC 1921 incorporates one functional Signal Processing Controller (SPC) entity, providing single-channel operation for Link 22. Three (of totally four) NILE defined communication modes are fully implemented: HF Fixed Frequency (HFFF), UHF Fixed Frequency (UHFFF), and UHF-EPM.
The „missing“ mode HF-EPM is ready for implementation but pending due to US regulations on TRANSEC availability. A proprietary AES-based TRANSEC solution – enabled by relaxed standardization – can be provided on demand but at the expense of violated lost interoperability.