ProVoice Twilight ???
As the person in TAC who did the Tech Support on VoiceGuard, AEGIS and then ProVoice for 11+ years, regardless of what Harris decides to do, ProVoice will be with us for some time into the future. They only thing Harris will NOT be supporting is new ProVoice systems (infrastructure), software updates and technical support through TAC (Technical Assistance Center).
There are still plenty of VoiceGuard and AEGIS users (and systems) out there, and will continue to operate because the equipment is robust and built to last, and there are a number of decommissioned systems that have been upgraded to P-25 which spares can be purchased from around the country and Canada.
I remember several years ago a public safety system in the Midwest that I supported the upgrade on during the rebanding period (2000’s). They were still using M-PD’s and Rangr’s with S-825 control heads and VG9600 boxes for DES Encrypted digital voice on EDACS. They did not own any Orion’s or M-RK’s. Nothing that new! They were making the jump from VoiceGuard w/DES to ProVoice w/DES. Their new radios were J725m mobiles and J700p portables. The make the migration a bit easier on them, a transitional patch was made using a pair of desktop stations, to take their VoiceGuard DES comms cross over to ProVoice DES. Clunky, but it worked.
Up until rebanding, there were still GE-Marc trunking systems on 800 MHz still operational here in the USA. The one I remembered listening to locally was the “Mountain Folks Mobile Network” in SW Virginia (Galax, Hillsville areas) which was used by farmers and other rural users.
The technology won’t die until there are no more spare parts!!!
Oh, and yes, the US Navy is still using Windows-XP today because of the security issues with Windows-7 and later operating systems being designated as a security risk. Service Pack-14 is current for them.