Cognitive Radio Network (CORNET) Testbed

Cognitive Radio Network (CORNET) Testbed
Vuk Marojevic, [email protected]
REU Class, Summer 2014
June 10, 2014
You will learn
1. A little bit of Spectrum Sharing Concepts and Terminology
2. What CORNET is
3. How to access CORNET
4. What you can do with CORNET
2
Contents
1. Mission
2. Context
3. Hardware
4. Software
5. Applications
6. How to Use
7. Use Case (Demo)
3
Mission
Develop a large-scale university testbed for research and education in
software-defined radio, cognitive radio and dynamic spectrum.
4
CORNET uses….
•
•
Commercial off-the-shelf (COTS) hardware
Open-source software
CORNET provides….
•
•
•
5
Free access to abundant resources
Common research tools
Testing facility for experimenting with custom hardware and software
Context
6
Software-Defined Radio (SDR)
Functionality of radio transmitter or receiver defined in software
Caution: it’s not just about software!
Cognitive Radio
Ambient-aware system able to reason, adapt and learn (cognitive engine)
Spectrum Sharing
Opposed to licensed, single-operator controlled spectrum
8
Spectrum Sharing Challenges
Protect
Incumbent
Users
9
Spectrum Sharing Concepts
TV White Space (TVWS)
Channel
Dynamic Spectrum Access (DSA)
TVWS
DSA
6 MHz channels in UHF band (470-
Potentially any
790 MHz)
Secondary
Access
Deployment
10
Database
Sensing
Trial and commercial pilots. TVBD* to
provide Interent access in unserved/
underserved areas: US, Europe, Asia,
Africa, Australia
Research testbeds and trials, DoD-funded
programs, …the future of wireless
communications
*TV band devices (TVBD)
Level
Description
Examples
0 Exclusive Use
Spectrum assigned on an exclusive basis
Licenses for cellular
communications today
1 Static Spectrum
Sharing
Spectrum shared by primary users on
geographic basis, not temporal basis
Exclusion zones
2 Managed Shared
Access
Subleasing for a certain period
Licensed Shared Access
(LSA)
3 Dynamic Spectrum First-come, first-serve of SUs, which must not
Sharing
interfere with primary users
TVBD, 3.5 GHz
4 Pure Spectrum
Sharing
3650 to 3700 MHz
11
Spectrum not assigned to a primary user,
different levels of protection/rules
Exclusive use
Spectrum sharing
Levels of Spectrum Sharing
Spectrum Sharing Trials and Testbeds
•
•
•
•
•
•
Sharing of government spectrum (PCAST), FCC workshop & NPRM
TVWS trials and commercial pilots around the world
DARPA Spectrum Challenge 2013/14
EU Cognitive Radio Experimentation World (EW) Federated Test Platform
PCAST Report: mobile test beds, test cities, …
WInnForum’s Annual Report, Section 5: DSA, White Space and Spectrum
Sharing Test Beds, Field Trials World Wide
• …
12
* PCAST: Presidential Council of Advisors for Science and Technology
7
8
4
5
1
62
3
9
10
11
14
13
16
12
15
17
13
Ongoing Trials
Completed Trials
Testbeds
Programs
Info on Spectrum Sharing
•
Wireless Innovation Forum (SDR Forum), http://www.wirelessinnovation.org/
•
DSA Alliance, http://www.dynamicspectrumalliance.org/
•
FCC, http://www.fcc.gov/
•
PCAST Report 2012, http://www.whitehouse.gov/administration/eop/ostp/pcast
•
Presidential Memorandum -- Expanding America's Leadership in Wireless Innovation
•
14
http://www.whitehouse.gov/the-press-office/2013/06/14/presidential-memorandum-expanding-americasleadership-wireless-innovatio
•
Academic papers: IEEE Xplore Digital library, http://ieeexplore.ieee.org/Xplore/home.jsp
•
…
Hardware
15
Physical Layout
http://cornet.wireless.vt.edu
• 48 software radio nodes, 12 per floor
• Free access for registered users
• Each node individually accessible, remotely
• FCC experimental license for several bands, 138 MHz – 3.6 GHz
16
Physical Layout
3550-3650 MHz NTIA Exclusion Zones
17
SDR Node
Gbit Ethernet
Radio Front End
Equipment
Server
Radio Front End
Server
Ettus Research/NI USRP2
Intel Xeon Quad-core (2.13 GHz)
WBX daughterboard
12 GB RAM
1000baseT Ethernet NIC (2x per node)
IPMI remote administration port
Devices
FPGA, ADCs & DACs
Processor, hard drive, memory, Gbit
Ethernet
Purpose
Filtering, up & down-conversion, ADC,
DAC, …
Digital signal processing (DSP)
18
Architecture
19
User Plane
Management Plane
• Users provided with personal NFS directory
• Web-based utilities for debugging and scenario
deployment
• Quick automated reimaging
• Flexible authentication services
Software
20
Open Source
•
•
•
•
•
•
•
21
Linux – Ubuntu 10, 13
GNU Radio – 3.5, 3.7
Open-Source SCA Implementation::Embedded (OSSIE)
LiquidDSP
ALOE Framework + open-source LTE waveform
LibLTE
…
License
22
FCC Experimental License
23
Lower Bound
(MHz)
138
150.5
157.45
162.0375
450
764
776
788
824
869
1850
1930
3400
Upper Bound
(MHz)
144
156
161.575
174
512
862
787
793
849
894
1910
1990
3600
Applications
24
Community Resource
University Education/Research
- Masters/PhD Thesis
- Class Projects
- Application development
Corporate Research
- Sponsored Research
- Rapid Prototyping
Knowledge Database
- Architecture replication
- User/Application Management
25
How to Use CORNET
26
Main sources:
27
•
http://cornet.wireless.vt.edu/
•
http://www.trac.cornet.wireless.vt.edu/trac/wiki/CORNET/HowToUseCORNET
•
http://scholar.lib.vt.edu/theses/available/etd-06052012142737/unrestricted/DePoy_DR_T_2012.pdf
Linux
•
•
28
Check who is using that node: who
Check who used that node: last
USRP/GNU Radio:
•
•
Check the availability of USRP: uhd_find_devices
Visualize the spectrum: uhd_fft or uhd_fft.py
•
Simple signal generators: uhd_siggen or uhd_siggen_gui
•
•
•
•
•
•
•
29
check options with … –h or … -- help
OFDM Receiver:
$ cd /home/cornetadmin/gnuradio_uhd/gr-digital/examples/narrowband
$ ./benchmark_rx.py -f 460M -r 500k
OFDM Transmitter:
$cd /home/cornetadmin/gnuradio_uhd/gr-digital/examples/narrowband
$ ./benchmark_tx.py -f 460M -r 500k
Use Case (Demo)
--LTE broadcast channel-30
OFDM
OFDM
32
Broadcast Channel
480 bits Subframe 0, 40, 80, ...
Scrambling
Subframe 0, 40, 80, 120, ...
40 bits
24 bits
every 40 ms
CRC
attach
1920 bits
Coding &
Rate
matching
QPSK
Modulation
480 bits Subframe 10, 50, 90, ...
Scrambling
QPSK
Modulation
240 symbols
Further
Processing
288 samples
240 symbols
Further
Processing
288 samples
480 bits Subframe 20, 60, 100, ... 240 symbols
Scrambling
QPSK
Modulation
Further
Processing
288 samples
480 bits Subframe 30, 70, 110, ... 240 symbols
24 bits
every 10 ms
CRC
detach
Decoding &
Rate
matching
Scrambling
QPSK
Modulation
Further
Processing
Descrambling
QPSK
Demodulation
Initial
Processing
Subframe 0, 10, 20, 30, 40, 50, 60 , 70, 80, 90, 100, 110, 120, ...
288 samples
Physical Broadcast Channel (PBCH)

PBCH (Transport channel): PHY Layer Resources


72 central subcarriers, first 4 OFDM Symbols of slot 1 of subframe 0, each radio frame
72*4 = 288 time-domain samples
PBCH carrying BCCH (MIB)
Radio Frame (10 ms)
34
MIB: Master Information Block
5 ms
35
5 ms
http://www.pewscorner.host-ed.me/LTE/lte_resource_grid.html
Demo
You can download and install on CORNET (any node) from
https://github.com/libLTE/libLTE
and try yourself
36
Summary
37
Cognitive Radio Testbeds – US Universities (extract)
CORNET (VT)
EMULAB (Utah)
ORBIT (Rutgers)
WNRT (UC Riverside)
38
NITRD Testbed Inventory
http://www.nitrd.gov/Subcommittee/wsrd/Testbeds/map.aspx
39
Outlook
40
Hallway
LTE-CORNET
Server room
Control room
…
Rack
Mobile
nodes
New DURIP Grant
Interferers/jammers
Interferers/jammers
Software LTE UE
Software LTE UE
Software eNB+EPC
Software eNB+EPC
SBX N210
SBX N210
Switch
Software eNB+EPC
24 Cornet Servers
(48 processors),
already deployed,
connected to 48
USRPs
Software eNB+EPC
N210
N210
N210
N210
N210
N210
SBX
SBX
SBX
SBX
SBX
SBX
Channel
emulator
8 Filter banks
RF
Switch
Matrix
Rfnest
(8 ports)
Σ
Ethernet
Σ
Filter
LTE Spectrum
Analyzer
LTE LTE
UE UE
Filter
N210 SBX
N210 SBX
Software
eNB+EPC
Software
eNB+EPC
Desktop
Desktop
RF nest allows:
- Using any frequency and bandwidth
- Using any modulation scheme
- Using different power levels for
signals and interferers
- CoMP Tx/Rx
- Carrier aggregation
41
CORNET Outreach
REDHAWK
libLTE
…

Download Report