FireWire Finds a Home in FlexRadio Systems’ Innovative New Software Defined Radios

Amateur, or ‘ham,’ radio users now number just under 700,000 across the US and in the millions worldwide. Most are hobbyists, and they are moving the technology along in exciting directions. The best example: the innovative new Software Defined Radio (SDR), which is defined as a radio communication system where components that are typically implemented in hardware – such as mixers, filters, amplifiers, and detectors -- are implemented using software on a PC or embedded computing device. Unlike traditional radios, which are fixed in features, functionality, and performance, the SDR can keep getting better all the time. 

In effect, an SDR is a collection of hardware and software technologies that enable reconfigurable architectures for wireless communications. They have become important backup emergency services communi-cations devices for police, fire, hospitals and first responders in all kinds of incidents including hurricanes and tornados. The US Department of  Homeland Security now looks favorably on SDRs and ham radios as an important emergency capability during many kinds of crises that knock out established communications systems.  

There‘s a growing market where radios like the state-of-the-art SDRs from FlexRadio Systems play a key backup communications role for hospitals and even transportation organizations like Federal Express and UPS during national or local emergency situations.  And, they use 1394, at 400 Megabits/second, to connect the radio with the computer, providing optimal performance and easy set up.

According to company founder Gerald Youngblood, FlexRadio Systems started a few years ago as a hobby project with the goal of exploring whether a computer sound card with DSP could be used with external RF equipment to turn the card into a radio. The original SDR-1000 depended on the performance of the sound card. The next generation FLEX-5000A moved the sound card (or its equivalent performance) inside the radio itself, according to Youngblood.  The basic requirement is for 8 in and 8 out streaming at 192kHz. “We looked at USB and FireWire and found USB was limited to 2-in, 2-out, and it and did not provide isochronous streaming or the millisecond real time control to optimize radio performance.  FireWire does.”  

The FLEX-3000 and FLEX-5000A radios now use 1394 devices in Windows-based applications.  Flex 3000 uses fewer channels and operates at 96kHz, while the 5000 uses all 8 channels plus mic-in and mic-out -- and the transmitter and receiver can simultaneously stream. 

Working with TC Electronics, Flex Radio stretched the limits of the FireWire devices. “TC reported that we are one of their best beta testers in part because we go into all kinds of different systems, from older Pentium-based Windows OS computers to the latest models,” said Youngblood. “Our customers are offering more detailed diagnostics information than TC normally gets on the Microsoft platform, so it’s useful for them. More Windows support, of course, is always a good development.”

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