Software Defined Radio (SDR) rulemaking at FCC is ’step forward’ ...

applications. SDR involves radios that provide software control of modulation techniques, wideband or narrowband operation, communications security functions (such as hopping), waveform requirements. For example, SDR user devices and network equipment can be programmed dynamically in software to reconfigure characteristics for better performance, richer feature sets or advanced services. SDR technology is applicable across wireless industry in both military and commercial sectors, Bose said. With its ability to adapt spectrum dynamically, “I'd like to see spectrum become a commodity that is traded” rather than auctioned as property, he said: “Spectrum licensing needs to be less static.” FCC should consider making it possible to “sublicense” spectrum. “In this way spectrum is used as a function of demand, not regulation.” Bose envisioned commodity spectrum market with authorized traders to whom wireless providers would make real-time bids on small geographic blocks “to acquire spectrum for region and time required, for next 3 years or next 2 weeks,” he said. Edward Thomas, chief of FCC Office of Engineering & Technology (OET), said Commission should give technology closer look: “The time is ideal to start a public dialog on the implementation of software radio as it bears on spectrum management, and what is needed to get the technology rolling.” Bose defined 3 classes of SDR: (1) Modal SDR, where equipment has more than radio mode built in. An example is handset that can receive both CDMA and AMPS wireless calls. (2) Reconfigurable SDR equipment, where all signal processing is reconfigurable in software. Military has developed technology in Speakeasy II project in which equipment is reprogrammable to accommodate 10 military radio systems. Reconfigurable SDR equipment usually is reprogrammed by manufacturer, rather than user, Bose said. (3) Software radio uses only software for signal processing and can be changed dynamically by user or service provider. “Software radio takes advantage of Moore’s Law,” he said, referring to rapid development of computer processors. SDR already is practical for fixed wireless infrastructure, he said. Bose said his company had developed systems that used “commodity off-shelf processors” to lower costs. Today’s general purpose computer technology allows “signal processing of 50 analog [wireless] channels on a single processor,” he said. Discussion moved to cellular handsets, application that he said was 3-5 years away. Problems are higher costs compared with single-purpose ASIC processor used in conventional handsets and higher energy consumption and heat from powerful processor. Admitting SDR never can be as efficient as single purpose ASIC, Bose said its advantage became apparent when more than one radio mode was needed in handset. Today SDR can be more cost effective if handset is designed to handle 3 radio modes: “I expect the crossover point to be 2 modes.” Power consumption and poor battery life will be solved “in future” only with more efficient processors and improved battery technology, he said. Formed by OET under Federal Advisory Committee Act to advise Commission on technical issues, TAC periodically gathers diverse group of academics, scientists and chief technology officers of technology firms representing telecom, data networking, software, consumer electronics and amateur radio interests. Next scheduled meeting is June 12.