Maybe two functions on Vara modem for users. 1-Register to a remote station 2-Unregister to a remote station Only if the remote station is a radio club and has te radio club vara modem versión. The user has the option to register to a radio club and receive messages from the radio club. One member always can use the radio and antennas of the radio club for make calls. Ok if i can understand you say VarAC can't handle messages for different users at the same time...

Ok. Maybe this is a Vara modem side implementation in first but users connecting to main stations with his vara modems to download or receive his saved messages.

When the identification is sent, the Varac can identify all the users in the club to receive messages about them. you know. This is not a good idea to implement unless the license is actually from a radio club or association with multiple users who can receive messages on their offduty time under the main station.