Forum: JANUS frequency bands

Re: Germany still has concerns about the primary JANUS band

Yes, concerns are still existing. The current MAC is not working.

Table II within ANEP87 covers a frequency range from 9440 to 13440 Hz. This disagrees with 2.1. Paragraph 2. stating 9440 to 13600 Hz. We need a change of this paragraph in the review process of STANAG 4748. The JANUS frequency band in ratification of ANEP-87 overlaps the frequency band given for voice communication in STANAG 1475.

The acoustical frequency band from 1 to 12 kHz is exclusively occupied for mil. hydro acoustical applications. Civilian underwater applications (see ISO/IEC 30140, 30143) have to use other bands. The navy needs silence.

I strongly recommend an "User class id"-based definition of the frequency band in JANUS. E.g. the use of User class id = 0 is coupled with the frequency bands of 1475, if and only if mil. assets are involved. Emission control with higher frequency bands is important also for marine mammals. For Hazard markers (wrecks, ...) I recommend the frequency band from 24 - 32 kHz (SALSA band). We need small transducers and a long endurance in small devices. Also frequency bands for the command and control of AUVs, gliders and NEMO floats (including First Contact) above 12 kHz have to be defined in this year.

Hydrophones are broad band; applications should inspect the frequency band of interest.

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