Cognitive Radio Network (CORNET) Testbed Cognitive Radio Network (CORNET) Testbed

Vuk Marojevic (maroje@vt.edu), Carl Dietrich, Jerry Park, Jeffrey Reed

https://cornet.wireless.vt.edu/

Original Mission Original Mission

Develop a large-scale university testbed for research and education in

software-defined radio, cognitive radio and dynamic spectrum access

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Broader Mission Broader Mission

• Support inter-disciplinary research (Institutional Infrastructure)

• Support external researchers and educators (Community Infrastructure)

• Support student contests

• Support development of innovative new class modules

MissionMission MissionMission

Indoor CORNET testbed (built in 2008-9)

• 48 SDR nodes, FCC license, user management

• 30 faster SDRs (X310 USRPs) + workstations

• 10 Gbps connectivity and switching

Outdoor CORNET (O-CORNET) (2013-14)

• 11 SDR nodes on campus rooftops

• 5 deployable nodes

LTE testbed (2014-16)

• eNodeBs and UEs

• RF channel emulator

• LTE test instruments

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Cognitive Radio Test System (CRTS)

• Open source framework (research on T&E methodologies) • Enables research & education on cognitive radios/networks and SAS • Now: test experimental SDRs/cognitive radios • Future: test prototypes and COTS products

CORNETCORNET--3D3D

•• WebWeb--based visualization of RF spectrumbased visualization of RF spectrum

•• Control of radiosControl of radios

•• GameGame--like interactive tutorials for educationlike interactive tutorials for education

Software-Defined Radio (SDR) Software • Open source: GNU Radio, Liquid-DSP**, REDHAWK**, LibLTE/srsLTE • Commercial eNodeB and UE software (Amarisoft)

**originated as / based on Virginia Tech projects 5

Lessons Learned: Testbed Design

Lessons Learned: Testbed Design

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• Physical access to hardware important for operation, maintenance,

characterization, upgrades…

• Regular hardware and software upgrades needed for system

usability and stability

• Pros and cons of having radio front ends and SDR computing

nodes physically collocated or distributed

Lessons Learned: User Access and SchedulingLessons Learned: User Access and Scheduling

Lessons Learned: User Access and SchedulingLessons Learned: User Access and Scheduling

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• CORNET is a shared resource

• Administrator-assigned hours may be inconvenient for users

• Rotating times and nodes for each team of student design challenge

• Accessibility can be enhanced by allowing users to self-schedule,

e.g. up to a limited/arranged number of node-hours per week

Lessons Learned: Documentation

Lessons Learned: Documentation

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• Thorough documentation important for enhancing accessibility and

usability

• Some users require much more detailed documentation than others

• Multiple levels of detail are needed from high-level descriptions

through step-by-step instructions

Lessons Learned: Testbed Management

Lessons Learned: Testbed Management

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• The equipment is only part of the testbed

• Experienced personnel to provide continuous operational support

• Users expect a very high level of reliability and availability

• Nodes should be monitored and rebooted as needed

• Support personnel who can rapidly diagnose and fix bugs

• User perceptions of technical support vary

• Consistently quick responses to questions appreciated

Role of University/City/NSF/Industry in Testbed Role of University/City/NSF/Industry in Testbed

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1. Support equipment acquisition, deployment and upgrades

2. Support operation and maintenance

3. Support research

4. Support transition to practice