Smart Radio: Spectrum Access for First Responders Sponsored by: Center for Wireless Telecommunications (CWT) and SDR Forum Mark D. Silvius, Terry Brisebois, Chen Chen, Qinqin Chen, Feng Andrew Ge, Bin Le, Paco Garcia Rodriguez, Tom W. Rondeau, Ying Wang, Alex Young, Charles W. Bostian #23 2007 June 6-8 Wireless Personal Communications Symposium The Challenge • Spectrum Access for First Responders – A large city experiences a major, crippling earthquake – Total loss of previously existing communication infrastructure – First Responders must stand up a makeshift command post and establish a temporary communication infrastructure • Problem – Find available spectrum within a pre-defined band – Rendezvous with an intended receiver – Transmit data over that band with a pre-determined Quality of Service (QoS) in urban conditions • System Goals – Mobile and User Friendly – Sense and Classify Environment – Interoperate with other Smart and FRS Radios – Operate in Master-Slave or Infrastructures modes – Adhere to FCC Spectrum Regulations Proposed Solution “Smart Radio” Design RF Front End Tx Rx Master Control Signal Detector Whitespace Information Signal Info Waveforms Link Control Decision Making Source Sink Codec Voice CSVD Data Source Coding Channel Coding FRS Radio and Smart SDR Signature Database Status QoS Desired Intended Recipient(s) or Channel Have FRS compliant spectral properties Dynamically change channels, with no service loss Must interoperate with legacy FRS users Ability to dynamically switch QoS settings Will not produce interference to any other active communications traffic Operate in a master-slave mode, or infrastructure mode Source & destination radios must be able to rendezvous 19.2 kbps using 8-PSK Rate ½ convolutional channel code 16 kbps using QPSK Reed-Solomon channel coding CVSD vocoded voice, Demonstrate at least 2 QoS settings Cognitive transceiver 25 kHz bandwidth 5 MHz FRS Band (462 to 467 MHz) Have FRS compliant spectral properties Dynamically change channels, with no service loss Must interoperate with legacy FRS users Ability to dynamically switch QoS settings Will not produce interference to any other active communications traffic Operate in a master-slave mode, or infrastructure mode Source & destination radios must be able to rendezvous 19.2 kbps using 8-PSK Rate ½ convolutional channel code 16 kbps using QPSK Reed-Solomon channel coding CVSD vocoded voice, Demonstrate at least 2 QoS settings Cognitive transceiver 25 kHz bandwidth 5 MHz FRS Band (462 to 467 MHz) Methodology: – Utilize modular approach for system conceptualization, design, and implementation – Primary functions partitioned into smaller self-contained blocks Table of Requirements System Block Diagram RF Front End • Utilizes the sponsor’s SDR platform for transmit and receive • Utilizes the SDR platform’s on-board digital filtering capabilities USRP USRP Lyrtech SFF Lyrtech SFF Antenna LNA/ Power Amp Band-pass Filter X Base- band Mixer Band-pass Filter Waveform Generation = Front End = Data Source Antenna LNA/ Power Amp Band-pass Filter X Base- band Mixer Band-pass Filter Waveform Generation = Front End = Data Source Antenna LNA Band-pass Filter X Base- band Mixer Band- pass Filter Waveform Recovery = Front End = Data Sink Antenna LNA Band-pass Filter X Base- band Mixer Band- pass Filter Waveform Recovery = Front End = Data Sink Hardware Front Ends – Customized for SR and FRS Radio Systems FRS #1 FRS #2 SR #1 and #2 Signal Detection & Classification (SD&C) • Characterizes the environment, so that the MC can decide in what vacant frequency ranges to establish a new links – Scans through the authorized frequency range and looks for unused spectrum to establish a new radio channel – Searches through the authorized frequency range for actively used spectrum Spectrum Scanning / Energy Detection SD&C Smart Receiver and Interfaces FRS Database • FRS database accepts a channel number as input and generates an XML file that specifies the waveform associated with the channel • MC block can poll the FRS database for Signal Classification FRS Database Table FRS Channel Selection RF Waveform Waveform Representation FRS Channel Selection RF Waveform Waveform Representation Master Control (MC) • Dynamically adjusts SDR’s power, frequency, waveform, CODEC, and QoS configuration settings in real-time • Directs Spectrum Scanning, Smart Radio Rendezvous, Channel Change Protocol, and maintenance of dynamic data links MC Module – Waveform Control Rendezvous Beacon Strategy FRS #1 FRS #2 SR Node #1 SR Node #1 SR Node #2 SR Node #2 Channel Change Protocol Ch. A Ch. B Master Node CODECS • Transform analog voice waveform into the a digital bit stream and vice versa using the CSVD format • Performs Reed-Solomon and ½ Convolutional Channel Coding for digital data streams • Automatically determine if the input from the user is analog voice signal or a digital data signal CVSD Decoded Voice Waveform CVSD Encoder Block Diagram • Faculty Advisor: Dr. Charles W. Bostian Alumni Distinguished Professor [email protected], (540)-231-5096 • Team Leader: Mark D. Silvius Ph.D. Student [email protected], (540) 231-2558 • Sponsors: Center for Wireless Telecommunications http://www.cognitiveradio.wireless.vt.edu/ SDR Forum http://www.sdrforum.org/ The Team