Asterisk Amateur Radio Network, AARN, is a possible branch for the HSMM. Asterisk is based on the ASTERISK PBX software. It has the capability to interconnect communications from and between Public Switched Telephone Network (PSTN), Internet Telephone (VoIP – SIP, IAX2) and Radio Communications Via Analog and Digital on HF, VHF, UHF, SHF. Using HSMM and Asterisk, multiple services can be interconnected for the served agencies. I will be looking into this for the future.
http://asteriskradio.net/wp/aarn/