I have been interested in Digital Radio since I became involved with packet radio, ax25, TCPIP and NOS about 15 years ago, shortly after obtaining my license. The interest was born from the fact that digital was less affected by noise.
I have been experimenting with building a Digital repeater that works with D-Star for about 18 months, in fact since I bought my first Icom 2820 back in 2007. I actually had a proof of concept design working before Icom had their first repeater on air in the UK. The basic design works well, with one small problem, interfacing to the D-Star gateway. Although Icom do not develop the software, they have commissioned it and provide it free with their repeaters. Working to the goal of being compatible with this software is not easy and as yet is not an option.
It now looks like the route, unfortunately, is via an Icom repeater and deep pockets. With-in the Northants Area there are a growing number of D-Star users and I hope to be able to provide a D-Star Node connected to the G2 gateway shortly.