Overview The first mode in a tiered marine Emcomm system known as Global Maritime Distress and Safety System - Wikipedia or GMDSS. You...

Point to point (P2P) 2.4 & 5 ghz Amateur Radio Emergency Data Network. Voice over ip (Voip), message (Meshchat), ip camera & data mesh...

Use that old or cheap dualband analogue HT & bring it back to life, fancy simple DTMF (old skool touch tones - remember dial up) call up...