CIREN (Cognitively Intrepid Radio Emergency Network) awarded "Best Design" in SDR Forum's First Smart Radio Challenge

By Carl B. Dietrich, Philip Balister, Carlos R. Aguayo Gonzalez, Zhang Chen, Drew Cormier, Joseph D. Gaeddert, S. M. Shajedul Hasan, Kyehun Lee, Shereef Sayed, and Haris I. Volos

Wireless@Virginia Tech’s MPRG team was awarded “Best Design” in the SDR Forum’s first annual Smart Radio Challenge for its approach to the problem of Spectrum Access for First Responders. This problem involved developing a radio system to establish digital voice or data connections among multiple radios using phase-shift keying (PSK) and quadrature amplitude modulation (QAM). The system was required to operate within the UHF Family Radio Service (FRS) frequency band, while avoiding interference to and from FRS users. A panel of industry judges observed a successful demonstration of the prototype system at the SDR Forum's annual technical conference, held in Denver, CO, USA, in November 2007. The judges cited flexibility and extensibility as strengths of the team’s system design and considered it the prime candidate for commercial investment among the entries.

Philip Balister led the team, and team members include Carlos R. Aguayo Gonzalez, Zhang Chen, Drew Cormier, Joseph D. Gaeddert, S. M. Shajedul Hasan, Kyehun Lee, Shereef Sayed, and Haris I. Volos. Dr. Carl Dietrich was the team’s advisor.

The team’s Cognitively Intrepid Radio Emergency Network (CIREN) solution targeted the Lyrtech small form factor (SFF) SDR development platform. The design used the OSSIE core framework, an implementation of the Software Communication Architecture (SCA) that was developed by Virginia Tech’s Mobile and Portable Radio Research Group. The SCA is an open industry standard developed for the Joint Tactical Radio System (JTRS) program. MPRG became part of Wireless@Virginia Tech in 2005.

The team’s solution also integrated into a single seamless package technologies and design tools from Lyrtech, Zeligsoft, Texas Instruments, Xilinx, and The MathWorks?. The design flow allowed prototyping and testing on Linux based PC's. The team ported the Linux kernel to the SFF SDR and demonstrated an experimental version of the OSSIE core framework running on the GPP. The team also demonstrated a spectrum sensing component running on the FPGA of the SFF SDR.

The prototype CIREN system demonstrated at the conference automatically establishes digital voice/data links in the UHF FRS band by employing a novel rendezvous protocol while avoiding interference and primary users. Dynamic spectrum access algorithms assist the radio in determining not only which channels are most likely to be unoccupied, but appropriate adaptation strategies when necessary. The CIREN radios support point-to-point digital voice and data links as well as broadcast modes all without the use of an expensive base station. Furthermore, the network is scalable and can dynamically add nodes without network reconfiguration. Each node scans less frequently to channels on which it has observed interference, reducing rendezvous time and mitigating the hidden incumbent user problem by disseminating shared sensing information throughout the network. The CIREN system is to be deployed on embedded and portable platforms running OSSIE.

The team’s work resulted in several related contributions including reusable processing components and related software planned for release with future versions of the open-source OSSIE software and a set of interfaces that incorporate metadata (descriptive information about the data being transmitted or received, such as how to modulate or demodulate it) implemented in a way that allows the same interface description language (IDL) files to be used for metadata-enabled and non metadata-enabled components.