editorial letter
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I had the pleasure recently of spending a couple of days at the 2007 Software Defined Radio Technical Conference and Product Exposition, otherwise known as the SDR Tech Forum. While SDR has so far been too power hungry to make it into handsets—ADI’s GSM/TD-SCDMA chipset being an early exception—it’s widely used in multi-protocol basestations. The latest prediction is that widespread adoption of 3G handsets that need to cover four or more waveforms on different frequency bands will make SDR techniques inevitable, by which time much of the power problem will have been addressed. The ability to make a single, flexible, inexpensive cellular platform that is easily upgraded and that works in all geographies—long the Holy Grail for handset makers—in only possible through SDR. The day one keynote speaker was Dr. Joseph Kielman, the Basic/Futures Research Lead in the Command, Control and Interoperability (CCI) office of the Science and Technology Directorate of the Department of Homeland Security (DHS); Kielman is also in charge of The Office for Interoperability and Compatibility (OIC). (I’m sorry, does that sound like a bureaucracy or what?) The OIC is working with the emergency response community and Federal partners to improve local, tribal, state and Federal emergency preparedness and response. First responders are all over SDR. At last year’s Tech Forum in Orlando, there were plenty of horror stories about the communications chaos surrounding Hurricane Katrina. This year in Denver the fires in Southern California featured prominently. Firefighters from different jurisdictions often couldn’t communicate with each other or with the police or National Guard, all of whom use different frequencies and modulation techniques. One short-term fix was SDR basestations that acted as translators, enabling diverse emergency teams to coordinate their activities. Kielman noted that there are over 80,000 different public safety jurisdictions in the United States, all of whom have different budgets and communications equipment. Being able to ensure voice and data interoperability between them is at best an Excedrin headache, and an expensive one at that. The SDR approach with the most traction in that space is APCO-25, a suite of standards for digital radio communications for use by federal, state and local public
Can Software Define Radio? john donovan, editor-in-chief
Portable Design blog For more detailed coverage of the SDR Tech Forum, including videos and podcasts, check out my new blog at www.portabledesign. blogspot.com.
safety agencies in North America. While not a fully adopted standard, the Department of Homeland Security will only fund equipment upgrades that are APCO-25 compliant. Kielman announced at the conference that DHS is setting aside $1B to help fund these upgrades. While Kielman admitted to Portable Design that the money was only enough to kickstart the conversion, it’s still a pretty big carrot and a notable endorsement of SDR techniques. The second keynote speaker was Dr. Shuzo Kato, the Program Director, Ubiquitous Mobile Communications, at Japan’s National Institute of Information and Communications Technology (NICT). Dr. Kato analyzed the use of cognitive radio (CR) techniques for dynamic spectrum utilization, an area where cognitive radio has proven quite capable. Being able to sense unused spectrum and dynamically share it without causing interference can go a long way toward increasing spectrum efficiency, which is a growing problem with urban cellular networks in general and the unlicensed ISM bands in particular. The highlight of the event for a lot of us was the Smart Radio Challenge Awards. Teams of grad students from around the world competed to solve the problems that Keilman, Kato and others highlighted. The winners were: 1. Virginia Tech CWT (Center for Wireless Telecommunications), which developed a smart radio system that will automatically find available spectrum within a predefined band and transmit voice or data over that band (the CWT team also won the Grand Prize); 2. Pennsylvania State, for developing a smart radio terminal that can automatically provide interoperability between radios with different modulations, and which knows how to forward messages to the proper network, whether commercial or civil; and 3. The Royal Institute of Technology (Stockholm), which developed a smart radio system that can detect the location of many vehicles within the city, assess their velocity along common roadways, and then provide user-specific route guidance that will minimize total fuel consumption. Right now SDR and CR are tackling some of the hardest and most interesting RF problems out there. Enabling you to step off a plane anywhere and expect your cell phone to work seamlessly is a much easier problem to solve. So in case there’s still any question, yes, software can define radio, and it will define its future, too.