Analog hotspot


I've heard some chatter about an analog hotspot, I believe it was an mmdvm-urdc, I would like to find out more and to see if there are any boards already available the could shield to a pi?

I saw where NW Digital had a urdc board for Dstar, is this something that could be used or is another board or an arduino required.

I would like to add one to my DR1x repeater and have another as a mobile hotspot?

Thanks for all replies

Rick N9UMJ