Darrin Eden, a fan of software defined radio says, “I don’t remember seeing anyone post this so… Open-Source Reference For Software Defined Radio is an oldie, but goodie. The location of the page for the code is here. Can you say Radio Virtual Machine?”
Software defined radios provide a solution to interoperability through software programability. Different radios, using different frequencies and modulations, can “redefine” themselves - on-the-fly - and “talk” to each other.
The idea grew out of the MIT SpectrumWare project, which in 1996 produced the first working software radio outside the military. Two years later, Vanu Bose, son of Amar Bose, the legendary designer of speakers and five friends took $200,000 of their own money and set up a small company called Vanu Inc. in Cambridge, Massachusetts, to commercialize the technology.
In the fall of 1998, Boeing asked the firm to join its consortium, which was competing for the military’s Joint Tactical Radio System project to create a single radio architecture for all of the US armed services.
Scientific American has a brief summary: “The hardware allows us to select any 10-megahertz region of the spectrum, convert it to intermediate frequency and then relay the signal to the RAM of an ordinary personal computer. All the signal processing is done on a general-purpose microprocessor, using a standard operating system”.
Companies like Equator Technologies are developing embedded technology that is soft-coded rather than hard-coded. Industry-standard operating systems like Linux are used. Equator’s MAP-CA and BSP-15 DSPs, “move the central functions of digital imaging, communications, and media applications into software, enabling a revolution in product functions, flexibility, and time-to-market.” SiGe is developing ultra-low power and small-footprint communications chips that work with GPS, Bluetooth, and Wi-Fi.
Software Defined Radio is fast becoming practical. Nextel, for example, announced an agreement with a start-up, RadioFrame Systems. Their (12″x4″) device works with wireless voice and Wi-Fi networks.
RadioFrame claims that its standards-agonistic system can alleviate cellular network loads by using a software-defined radio. It detects and registers wireless users within an indoor facility. Calls for those users are forwarded to the RadioFrame minicell site instead of a standard, outdoor cell site. Nextel is trialing RadioFrame’s system. It provides indoor coverage for cellular providers as well as support for wireless LANs.
Which, I guess, brings up the question; is it possible that a software defined 802.11b/cellular “hot spot” could actually “hijack” a cellular call, route it through an all IP network, and deliver voice as well as data services?
With software defined radio, anything seems possible.
