Monitoring availability of selective call radios in a half-duplex radio communication system

A half-duplex radio communication system coupled to a plurality of SCRs, comprising

• a plurality of radio base stations coupled to the plurality of SCRs;
• wherein elements of the half-duplex radio communication system and a source SCR of the plurality of SCRs are programmed to:
• receive a monitor request message from a source SCR of the plurality of SCRs to determine a call availability status for each of a first list of at least one target SCR of a group member list of the source SCR;
• submit from the select one radio base station a call availability status request to each of the first list of at least one target SCR;
• submit from the half-duplex radio communication system to the source SCR a response state corresponding to the call availability status request of each of the first list of at least one target SCR;
• and
• update the group member list according to the response state for each of the first list of at least one target SCR.

A source SCR coupled to a half-duplex radio communication system, comprising

• a transceiver;
• and
• a processor coupled to the transceiver;
• wherein the source SCR and the half-duplex radio communication system are programmed to:
• receive at the half-duplex radio communication system a monitor request message from a source SCR of the plurality of SCRs to determine a call availability status for each of a first list of at least one target SCR of a group member list of the source SCR;
• submit from the select one radio base station a call availability status request to each of the first list of at least one target SCR;
• submit from the half-duplex radio communication system to the source SCR a response state corresponding to the call availability status request of each of the first list of at least one target SCR;
• and
• update the group member list according to the response state for each of the first list of at least one target SCR.