The issue of D-STAR repeaters using the Amateur Satellite segments at 145.8, 435 and 1260 MHz has been of considerable concern in IARU Region 1.
This matter is addressed in Edition 52 of the International Amateur Radio Union Region 1 VHF/UHF/uW newsletter.
See D-STAR repeater interference http://www.southgatearc.org/news/august2009/dstar_repeater_interference.htm
direct link to download newsletter PDF http://www.iaru-r1.org/index.php?option=com_remository&Itemid=173&fu...
Those in North America may not be aware that in the most of the world there is at best only 430-440 MHz available to the Amateur Services and in many areas only 432-438 MHz or less is available.
In those countries I am aware of 430-440 MHz is shared with the Primary user - the Military - who use it for high power Radar, data links and voice communications.
Here in ITU Region 1 (Europe) 433.075 to 434.795 MHz is also License Exempt spectrum for short range devices, which means anybody can use it without requiring a license. There are power limitations for license exempt short range devices but equipment that can operate on this band at far higher power levels is readily available. Unauthorised higher power equipment can also operate up to 435.525 MHz.
References: Intek DRS-5070 PMR-446 Radio (also 433/434/435) http://www.southgatearc.org/news/august2009/intek_drs5070_pmr446_radio.htm
Thames Estuary interference on 433.500 MHz http://www.southgatearc.org/news/may2009/thames_estuary_interference..htm
Short range devices in the 433 MHz band http://www.southgatearc.org/news/august2008/short_range_devices_in_433mhz_ba...
73 Trevor M5AKA