You are here

Broadband Wireless Access & Applications Center (BWAC)

Catholic University of America

North Carolina State University

University of Arizona

University of Mississippi

Virginia Tech

Last Reviewed: 12/01/2018

This center focuses on broadband wireless technology access and its applications. The Center website is: http://bwac.arizona.edu

Center Mission and Rationale

The mission of BWAC is to collaborate with industry research partners to create flexible, efficient, and secure wireless systems that satisfy broadband communication needs. The intertwined and multi-faceted nature of such complex systems calls for a diverse range of complementary expertise in antenna design, radio engineering, signal processing, wireless communications, networking, cloud computing, and security, as well as research tools (modeling, simulation, hardware/software prototyping, platform integration and maintenance, and measurements and data curation). The breath of such a research program necessitates collaboration among multiple research teams and partnering with pioneering private companies and federal agencies in this field.

Each university site brings to the center unique skillsets and strengths. Specifically, UA has significant expertise in 5G/LTE/Wi-Fi wireless protocols, spectrum sharing, mmW systems, and physical-layer security. VT is renowned from its research on security and privacy in dynamically allocated spectrum for heterogeneous wireless technologies. Antenna design at high frequencies is led by the team at UMiss, with supporting expertise from UA. The CUA team is leading the efforts in MEC and its role in supporting ultra-low-latency communications. UMiss brings valuable expertise in the area of computational electromagnetics, including modeling and simulation of antenna cloaks, supported by fabrication and testing at the UA site. The NCSU team focuses on advancing wireless technologies and services in unmannered aerial systems. Although each site exhibits critical mass in one or more BWAC thrusts, synergies arise naturally between researchers across different sites due to common interests. Such synergies have been instrumental in enabling collaborations across sites.

Research program

Spectrum sharing for heterogeneous wireless systems

The FCC has recently allowed wireless providers to operate over the unlicensed bands (e.g., 5 GHz UNII, 5.9 GHz for C-V2X and DSRC). This raises several issues related to contention among systems that operate or will likely to operate over these bands. This thrust studies the impact of inter-technology interference and devises innovative approaches for enabling harmonious coexistence of heterogeneous wireless technologies in unlicensed bands. Topics include spectrum sensing; interference-mitigation techniques and protocols; inter-operator spectrum pooling/aggregation; spectrum sharing under directional transmissions; spectrum economics; coexistence of Wi-Fi and Bluetooth-BLE; and heterogeneous coexistence under full-duplex capabilities.

Secure and private wireless communications

Physical layer security (PLS) relies on generating friendly jamming (FJ) signals to obfuscate transmitted information, so as to improve the signal quality at the legitimate receiver and degrade the signal reception at the eavesdropper. This thrust investigates various issues including information-theoretic secret communications; channel-based authentication and fingerprinting; jamming-resistant protocols; rendezvous and network/device discovery under stealth (selective) attacks; hiding of side-channel information; and security in dynamic spectrum access systems.

Beamforming and Massive MIMO for mmW Systems

Massive MIMO is appealing for millimeter wave (mmW) communications as the short wavelength allows large antenna array deployed and the large beamforming gains overcomes high path loss at mmW band. Developing computationally efficient algorithms for massive MIMO based beamforming in mmW is crucial for 5G systems. Topics include precoding in multi-user MIMO systems and peer-to-peer (e.g., mobile ad hoc) systems; game-theoretic analysis of distributed mutually interfering MIMO systems; full-duplex MIMO designs; receiver localization in Massive MIMO beamforming networks; and signal classification.

Analog Beamforming for Blockage-resistant mmW Communications

mmW systems suffer from long device discovery time during initial access (IA) as well as vulnerability to blockage. Developing IA protocols that are robust to blockages and with short discover time are essential for mmW systems. Topics include mmW channel modeling; mmW antenna subsystems and low-power circuits; beam-tracking designs; beamwidth adaptation; hybrid analog/digital beamforming; backhauling protocols; user-BS association and handover in a multi-BS mmW systems; and outage-resilient mmW protocols.

Collaborative MEC Systems for Ultra-low-latency Applications

MEC has been embraced by many mobile network operators (MNOs) as a way to create new business opportunities and increase revenues. By developing novel architectures and algorithms to enable autonomous and efficient data processing and networking through cooperation of edge nodes, mobile users, and cloud data centers, ultra-low-latency (millisecond order) applications can be supported. Research topics include delay analysis for ultra-latency MEC protocols; energy/Quality of Experience (QoE) tradeoffs; collaboration between edge nodes within a single MEC operator; dynamic network slicing; machine learning algorithms for latency prediction and task assignment; task partitioning and user-edge node association; MEC-integrated V2X applications; and privacy-preserving MEC collaboration protocols. 

Metasurface Cloaks for Cloaking and Decoupling of Interleaved Phased Antenna Arrays for 5G Wireless Applications

Investigation of elliptical metasurfaces for decoupling and cloaking of closely spaced printed antennas and phased antenna arrays for 5G wireless applications: Preliminary results demonstrate a reduction of mutual coupling in strongly coupled antennas and antenna arrays and the restoration of radiation patterns as if the radiating elements were isolated; the use of metasurface cloaks in interleaved antenna arrays enables the independent operation of the arrays with good matching, radiation, and beam scanning characteristics.

Facilities and Laboratory

1. Wireless Communications and Networking Laboratory (WiCON) at University of Arizona:

(a) Two NI-USRP RIO (400 MHz to 4.4 GHz) with embedded 2-by-2 MIMO capability, GPS, and Kintex-7 2M FPGA; (b) 11 USRPs (four NI-USRP 2922, two NI-USRP 2932 with GPS, and ve Ettus USRP2s Rev 4.0 with various daughter boards); (c) two high-end NI PXIe-1082, 8-Slot PXI Express Chassis for FlexRIO platforms with PXIe-8135 Core i7-3610QE 2:3 GHz controllers, PXIe-7975R NI-FlexRIO 2M FPGA modules, and two NI-5791 4:4 GHz RX/TX adapter modules; (d) Agilent's Vector Signal Analyzer with 85 MHz instantaneous bandwidth; (e) Agilent's Vector Signal Generator; (f) Agilent's N9923A FieldFox Handheld RF Vector Network Analyzer; and a variety of experimental accessories (directional antennas, circulators, etc.). FlexRIO provides a high-performance, flexible reconfigurable I/O platform that allows for transmission/reception over up to 100 MHz instantaneous bandwidth in the 200 MHz to 4:4 GHz frequency range. The FlexRIO adaptor is connected to a PXI Express through an FPGA, providing high-throughput and fast communication between different synchronized slots.

Available simulation and code generation tools include LabVIEW and LabVIEW FPGA, ns-3, ns-2, OPNET (with the radio module), QualNet (complete kit, which includes the Advanced WiMAX/IEEE 802.16 Wireless module, Military Radios Library, TIREM Propagation Library, Urban Propagation Library, ALE/ASAPS Propagation Library, Network Emulation Interface, etc.), Matlab, CSIM, MaRS, REAL, Ptolemy, and Javasim.

2. Aerial Experimentation and Research Platform for Advanced Wireless (AERPAW) at North Carolina State University:

(a) Software define radios (SDRs): NI USRP (X310,N310,B205,mmW); (b) 5G NR: 5G gNBs and UE from Ericsson; (c) RF Sensors: Keysight RF and Nemo Sensors; (d) IoT Devices: SigFox / LoRa; (e) Unmannered Aerial System (UAS) Radar: Fortem SkyDome; (f) UWB: Time Domain P410/P440 radios; (g) Facebook radios: Terragraph 802.11ad radios.

3. University of Mississippi:

(a) NSI Planar Near-Field scanner that allows for the measurement of antenna systems up to 35 GHz- has capabilities for the measurement of near-field and far-field patterns in the scanning plane as well as inverse holography for the measurement of surface currents on the measured devices; (b) Anechoic far-field chamber that allows for direct pattern measurements for omni-directional antennas up to 20 GHz; (c) Three vector network analyzers- can 50 test up to GHz for standard coaxial connections and 75 GHz for waveguide systems; (d) Two milling machines capable of fabricating antennas, transmission lines, and other microwave layouts on a wide variety of materials.

4. Wireless at Virginia Tech:

Facilities include fully functional Radio Frequency (RF) and SDA laboratories for modem development, an RF anechoic chamber, instruments for antenna measurements, instruments for RF component measurements, an antenna range, chip fabrication facilities, and a workstation environment with design tools such as MATLAB, ADS, and Cadence. In addition, the center has custom hardware tools such as MIMO propagation measurement systems, Software Communications Architecture (SCA)-based radios, an 8-GHz UWB receiver, a major cognitive radio test-bed, and a 1-GHz sliding correlator for spectrum and propagation measurements. A recently built LTE repeater is fully functional and has been used for testing on various occasions. Many of the special hardware tools were custom built at Wireless@VT.

This laboratory includes test equipment such as signal generators, spectrum analyzers, and network analyzers. The laboratory also includes soldering stations suitable for work with surface-mount components, RF cables, attenuators, splitters/combiners, directional couplers, and other miscellaneous hardware along with design and simulation software for circuits and printed-circuit boards.

Available software includes SDR and other open-source software (GNU Radio, Liquid DSP, REDHAWK, OSSIE, and Linux OS including command line and GUI software development tools and compilers). The team also has access to statistical packages such as R, SAS, and MATLAB.

Wireless@VT has successfully deployed a real-world cognitive radio network testbed throughout a research building (called ICTAS) on VT’s campus. The testbed consists of 48 USRP2 nodes deployed within the ceilings of ICTAS, with 12 nodes on each of the building’s four floors. Each USPR2 node is outfitted with custom Motorola RFIC daughter cards and is connected by gigabit Ethernet directly to the powerful rack server of our dedicated cluster. A total of 28 two-node racks make up the cluster, and each node contains two Xenon CPUs, for a total of 8 CPU cores and 12 GB of RAM per node. Such powerful hardware allows us to run the sophisticated signal processing algorithms and SDR waveforms required to perform Cognitive Radio (CR) experiments in real time. In addition to the 24 racks connected to USRP2’s, CORNET employs four racks dedicated to network management and administration. An image server provides automated re-imaging capabilities and a firewall, and an LDAP server provides security/authentication. A dedicated NFS server is employed at the user plane in order to provide researchers with a private directory to store scripts, programs, and test results. Many of the experiments and demos that have been produced thus far have exploited the remote capabilities of CORNET by employing custom web interfaces, and many of the administrative tasks can now be performed using only a browser.

Recently, the center of engineering and advanced research (CAER) awarded Wireless@VT a grant to develop an LTE repeater for the 3.5 GHz band. This repeater is built using PicoRF, a state-of-the-art software-defined radio platform developed at Wireless@VT. Currently, the repeater is used to translate LTE signals in the 700 MHz band to the 3.5 GHz band. The repeater is used to experimentally test dynamic spectrum access based on LTE in the 3.5 GHz band without interfering with the existing network. Because it is built using a flexible platform, it can also be used to effectively change the operational frequency of commercial wireless devices such as cell phones, WLAN routers, and so on. 

5. Wireless Networks and Mobile Computing Lab at Catholic University of America:

The lab has a wireless networking and mobile edge computing testbed. The testbed consists of 20 radio nodes and several USRP Software Defined Radio (SDR) nodes connected by Pica8 48 x 1G SDN Switches, which can be dynamically interconnected into specified topologies and virtualized into multiple slices. Each radio node equips with an Intel i7 quad core processor, 32 GB memory, two WiFi and two Gigabit Ethernet interfaces along with management software for virtualization and mobile edge computing. The experiment parameters at the nodes can be configured and controlled via a management framework, and flexible peer-to-peer connections and network virtualization are supported. The lab also has simulation tools including ns-3 and ns-2 network simulation packages, Matlab, etc. These equipment and tools allows us to perform the proposed design, modeling, simulation, and testing tasks.

Locations

University of Arizona

1230 E. Speedway Blvd.
P.O.Box 210104

Tucson, Arizona, 85721-0104

United States

Virginia Tech

302 Whittemore (0111)
Virginia Tech

Blacksburg, Virginia, 24061

United States

University of Mississippi

302 ANDERSON HALL

UNIVERSITY, Mississippi, 38677

United States

Catholic University of America

620 Michigan Ave NE

Washington, District of Columbia, 20064

United States

202-319-5275

North Carolina State University

890 Oval Dr

Raleigh, North Carolina, 27606

United States