A Brief History of Asterisk Radio Over IP
Most people don't know that Asterisk was designed from the beginning with radio applications in mind.
Jim Dixon (WB6NIL) developed pioneering hardware and software and collaborated with Mark Spencer of Digium to make Asterisk a reality. Jim (a.k.a. Duuuude) says that compatibility with Amateur Radio applications was always a design requirement for his Asterisk work.
Steve Rodgers (WA6ZFT) is a longtime friend of Jim's and they co-developed the app_rpt module and the Quad Radio PCI card to interface radio equipment to Asterisk. Steve's company QRVC Communications offers the Quad Radio PCI card for sale.
Steve Henke (W9SH) wanted to use hardware that would provide baseband (receiver discriminator and transmitter modulation) signal processing. This allows noise squelch detect, RSSI, CTCSS and other signaling protocols to be done in software and provide additional features. The answer to this need was found in a low cost USB Sound Adapter. Steve and Jim collaborated on the chan_usbradio driver and Steve's company Xelatec contributed the xpmr radio signal processing routines under the GPL to the project.
The Xelatec XIPAR project combines the Asterisk® VoIP PBX with radio interface software and hardware that provides the following for Amateur Radio stations and systems:
- A Full Function Multi-Site Linking Repeater Controller
- Touch Tone Command and Control
- Autopatch - Reverse and VOX Operation
- CTCSS Decode/Encode Functions
- Asterisk VoIP Private Branch Telephone Exchange
- Voice Mail and Announcements
- Contact Closure Telemetry and Announcments
- Non-Proprietary Software and Hardware
- Open Source Linux Operating System
- Remote Base PTT Dispatch Client Software for PC's
- A Fully Configurable and Programmable Communications Solution
Complete with a GUI interface