Hi
From what they describe in the video it appears to be a mesh network setup which makes for convenience of operation. However I doubt it was used as the main system for comms between entrance and rescue site. They look like modified UHF units. That frequency won't go through rock or sumps. In some places in some caves it will propagate via "wave guiding" along some passages. I do know that Heyphones and Nicola phones were used. They came from the British and French cave rescue organisations. There are a couple of Nicola's in Australia ready for any major cave rescues. They use VLF (very low frequency) and will go through rock. Bandwidth is limited due to the low freq. With the depth of that rescue even through-the-rock VLF will have problems.Quote:
Originally Posted by bob10
Mike
