A method and device enables programming inter-subsystem interface (ISSI) identity data, which identifies at least one of units or groups operating in a communication network, into at least one unit associated with a first radio frequency subsystem. The method includes receiving the ISSI identity data at the first radio frequency subsystem from an ISSI communication node, wherein the ISSI identity data identifies at least one of unit information or group information associated with a second radio frequency subsystem operating in the communication network. At least a portion of the ISSI identity data is then programmed into the at least one unit associated with the first radio frequency subsystem.