Sumit Roy - US grants

9818315
Liu, Hui
Azizoglu, Murat
University of Washington

CISE Research Instrumentation: A Broadband Software Radio Testbed for Research in Wireless Communications

This research instrumentation enables research projects in:

- Wireless Laboratory Enhancement,
- DSP Solutions for Low Complexity Multi-User Detectors, and
- Bit-Interleaved Coded Modulation for Wireless Data Network.

To support the aforementioned projects, the Department of Electrical
Engineering at the University of Washington will purchase microware testing
equipment and computing facilities for upgrading an existing wireless
communication laboratory. The equipment is used to set up a broadband
software radio testbed which consists of a multichannel RF transceiver
module, a multiple broadband data acquisition system (>10Ms/c/s), an
arbitrary RF signal generator, and a wireless channel fading simulator. The
new testbed enables experimental research in the areas of broadband
multiple-access, multiuser detection, time/space diversity combining,
wireless networking, as well as other potential multidisciplinary research
related to personal communication services (PCS). Both the quality and
scope of on-going and future research in wireless technology is enhanced
by the proposed instrumentation. Anticipated impacts of this project
include larger capacity, better interference and fading resistance, and
higher power efficiency and system flexibility for wireless systems.

Interconnect has been recognized one of ten hardest problems in nano technologies. A basic observation underlying this project is that nano-interconnect issues are much similar to that in real-world communication. Much research has been conducted to ensure the reliable, fast and secure communication over a noisy and stochastic environment. Therefore, the research is exploiting communication-theoretic principles and developing innovative signaling concepts in solving the stochastic nature of nano interconnect. The primary focus is on nano silicon technologies in CMOS with feature sizes below 100nm, and the goal is to explore ways to achieve reliable and fast signaling over the noisy and stochastically limited nano-interconnect environment. The specific objectives are
1. to develop realistic-yet-simple communication models for various nano interconnect scenarios,
2. To study fundamental signaling limits dictated by communication theory (estimates of achievable rates indicate up to Tbits/sec.),
3. to demonstrate interconnect design techniques for nano-signaling that can potentially approach the theoretical signaling limits
This is being made possible by a combination of several innovations that include (i) multi-wire (differential) full-duplex signaling, (ii) signal modulation, coding and equalization, and (iii) utilization, instead of avoiding, very-deep-submicron (VDSM) effects such as wave transmission for potential signaling.

Abstract

Program: NSF 04-588 CISE Computing Research Infrastructure
Title: CRI: Acquisition of Research Instrumentation Infrastructure for Next-Generation Broadband Communication Systems

Lead Proposal: CNS-0551686
PI: Henderson, Thomas R.
Institution: University of Washington

Proposal: : CNS-0551378
PI : Riley, George F.
Institution: Georgia Tech Research Corporation - GA Institute of Technology

Proposal: : CNS-0551706
PI : Floyd, Sally
Institution: International Computer Science Institute


Investigators at the University of Washington, the Georgia Institute of Technology and the International Computer Science Institute will re-design, enhance and maintain the Network Simulator to address research and education challenges for the next generation of data networks. Improvements will include a new simulator architecture, new models for wireless networks, provide for software encapsulation, and integration of the tools with virtual network testbeds. The changes will enhance scalability, extensibility, and new application program interfaces that open the simulator to open source networking software. Emulation capability will be improved to allow integration with testbeds.Wireless modules will be rewritten to track advances in wireless networking. Educational scripts will be facilitated in the enhanced version. The Network Simulator is heavily used in research; these improvements will allow it to continue to be a leading resource for

The objective of this research is to formulate design principles for and demonstrate, via prototyping, the feasibility of a new sensor network of everyday objects based on radio frequency identification (RFID) system components. The vision exploits the advantages of RFID while addressing two key challenges, namely the lack of sensor integration onto RFID tags and the need for careful redesign of the transceivers (i.e, down and up links as well as the multiple access protocol). Central to the success of the proposed research are two key advances already in place at University of Washington-Intel Research Labs. First, a new class of passive RFID tags, called wireless identification and sensing platforms (WISPs), integrated with appropriate sensors and designed for enhanced power harvesting are available. Second, a software-defined reader (SDR) that allows innovation of link and medium access control (MAC) protocols is available.

With respect to intellectual merit, the research pursues an integrated systems solution to RFID network design at various interacting levels of abstraction. As an example, the research considers coupled circuit and electromagnetic simulation that characterizes the back-scattered uplink signal at the reader, which in turn can suggest link and MAC layer components, such as modulation and coding as well as collision avoidance dedicated to interference mitigation.

With respect to broader impacts, the research has the potential to accelerate academic research into RFID networks via freeware distribution of the SDR code and limited availability of WISPs as well as dissemination via topical tutorials. Successful execution of the project can move RFID technology from its intended application of reading tag IDs within a supply chain environment toward the more ambitious goal of realizing a ubiquitous "internet of things."

Integrative, Hybrid and Complex Systems
University of Washington
Hui Liu
Design and Prototyping for Network Convergence

The objective of this research is to develop new network architectures for achieving convergence of digital broadcasting and (two-way) cellular data networks while delivering the quality-of-service necessary for multimedia distribution. The research approach is two-pronged. The first component is a joint design method for hybrid services to be natively supported in a collaborative cellular network. The second component of the research is a method for dynamic spectrum reuse within an extended cognitive radio (IEEE 802.22) framework.

Intellectual Merit: This project addresses theoretical questions and associated system design issues underpinning the transition of next-generation digital broadcasting to broadband collaborative networks. The problems addressed are relevant to the recent availability of new radio frequency spectrum for broadcast and emerging industry standards, such as MediaFlo and Mobile WiMAX, that similarly seek an evolutionary path towards such a convergence. The project, while not specific to the above technologies and standards, is intended to result in cross-cutting commercial impact.

Broader Impacts: The research seeks new architectures to provide significant capacity gains and spectrum saving in converged networks as compared to traditional, isolated wireless networks. Integral to this work is the cross-training of information technology professionals and scientists in communication and information theory as well as in networking and practical wireless system design. Further, the investigators plan to communicate results from this research to inform the IEEE Task Group 802.22 in its consideration of standards for network convergence.

This project is developing new simulation frameworks for the ns-3 discrete-event network simulator, a free and open-source research tool designed for use by computer communications network researchers. Simulation remains in heavy use for network research and education, because of its ease of use, reproducibility, availability, scalability, and ease of software development. However, the workflow of a typical simulation study requires the user's careful attention to a number of best practices in methodology to ensure that the results are credible and reproducible by third parties and that errors are not introduced. This project is building an automation framework for the ns-3 simulator that provides an environment that is more conducive to the creation of rigorous studies. The automation framework guides the user to produce valid network simulation models by composition and consistency checking, and definition of experimental settings. The framework exercises control over large-scale simulation studies, and applies statistical methods for output data analysis and execution control. The framework also collect details required to reproduce the experiment and report results. The framework also allows users to specify wide ranges of simulation network topologies, application traffic, and other parameters, allowing experiments to be conducted on a wide range of scenarios with minimal effort. Finally, maintaining the ns-3 software, documentation, and dissemination activities continue. The additions to ns-3, disseminated as open source software, are improving the methodology and credibility for future simulation-based network research.

There is growing global importance of ocean exploration and monitoring as the oceans play a major role in climate regulation, nutrient production, resource retrieval and transportation, etc. Building and deploying a real-time underwater networked sensing infrastructure is thus needed for desired levels of monitoring and data collection. Despite a wave of research efforts in the area of underwater wireless networks, the lack of a community testbed has so far hampered further advances, as there is no common platform to evaluate and compare various communication and networking algorithms and protocols. Furthermore very few studies can afford to consider real system features due to the high cost of system deployment and maintenance.

This project involves the design and deployment of an open underwater testbed suite, accessible to the public at four sites in Connecticut, California, Texas, and Washington States. The testbed will include flexible choices of surface nodes, bottom nodes, and mobile nodes with reconfigurable modems. It will enable the vision of remote controlled and continuous networked node deployments running tests of communication, networking, sensing, and data streaming. In addition, the testbed will enable oceanographers to study scientific research questions, while using the testbed as a prototype for larger real-time monitoring deployments elsewhere. The testbed will also directly impact undergraduate research and student diversity by involving undergraduate students through REU programs, impacting curriculum development by enabling field courses, and engaging K-12 students and teachers, particularly in underserved communities.

Network simulation continues to be an indispensable tool for performance evaluation of wireless network protocol stacks for it's ability to explore fine-grained causal input-output relations and network scalability aspects, that cannot be readily studied by other means. This project will add much needed ingredients to ns-3 (the most commonly used open source simulation tool for networking research) and extend its capabilities beyond those in comparable commercial tools in important ways.

Network simulation methodologies face a fundamental dilemma - increased realism only comes with greater simulator complexity. The pathways proposed provide the best, most realistic approaches to achieving a proper balance. The agenda broadly concentrates on a new wireless protocol stack library that efficiently incorporates cross-layer design approaches that capture the coupling between parameters at Layers 1-2 and protocol elements at Layers 3-4. Further, coupled simulation-emulation approaches that balance the flexibility of the former (software simulation) with the fidelity of the latter (testbed or emulator) will enable new design and performance analysis techniques. All freeware will be disseminated via the ns-3 website (www.nsnam.org) under usual GPL and publicized via tutorials at conferences and workshops.

The proposed planning activity seeks to undertake planning of the establishment of a new Industry/University Cooperative Research Center (I/UCRC) for Smart Ocean Technology at the University of Connecticut and the University of Washington. The proposed Center seeks to promote and harness robust technological advances in computing, communication, control, devices, instrumentation and platforms that have the potential to provide persistent observation and exploration capabilities for aquatic environments. A distinguishing feature of the proposed center is the emphasis on integration of intelligence/awareness (e.g. `smart) at various levels of underwater systems design in order to achieve the agility necessary for the desired robustness, persistence and cost efficiencies.

The planned center intends to focus on creating novel technologies in the areas of communication, power, sensing, and platform systems for the ocean application domain. The resulting systems and the insights they produce about the ocean will inform technical and policy efforts in areas of global impact such as weather/climate, food resources, and sustainability. The center plans to have a significant impact on students via interdisciplinary research engagement. Further, educational outreach to various community organizations (schools and science/technology museums, notably) is expected based on products - data, images and streaming video - resulting from the work conducted at the center.

The recent wave of radio spectrum deregulation encourages shared use of underutilized spectrum (so-called 'white spaces') where licensed users (primary) co-exist with unlicensed or lightly licensed users (secondary). Federal Communications Commission (FCC) has recommended use of online spectrum databases to ensure that primary communications are protected against interference coming from secondary communications. However, these databases provide notoriously poor estimates of whether a primary communication is active as they are based on empirically driven radio propagation modeling. This accuracy issue ultimately weakens the business case for white space networks, particularly in urban regions where the demand of both primary and secondary use is high.

The core intellectual merit of the project is a fundamental rethinking of the current approach to spectrum databases. The project develops a functional system architecture that improves the spectrum database estimates by integrating the current modeling-based approach with distributed spectrum measurement data. The project delivers the key components necessary to realize such measurement-augmented database system: (i) open access spectrum observatory tool backed by models and databases, (ii) a spatial statistics-based approach to integrate modeling and measurement data, (iii) practical methods to collect large-scale, distributed spectrum measurement data to feed into the database.

Success in the project will revitalize the interest in white spaces among commercial operators and also will help FCC in future spectrum policy formulation. The open access spectrum observatory tool will provide researchers with significant data sets and models. The project also plans technology transfer and cross-disciplinary educational efforts in wireless systems.

This project will establish a new virtual institute for promoting and sustaining cognitive wireless networking related research and education collaborations between the U.S. and South Africa. A major emphasis is on the investigation of the fundamental challenges related to low cost, reliable wireless broadband access technologies for traditionally underserved areas using dynamic spectrum access/sharing/management techniques that exploit spectrum (e.g., T.V.) white spaces (WS). By providing an umbrella that gathers the knowledge learned from past collaboration experiences, enhances ongoing projects through cross-fertilization, and spurs new projects through virtual and physical meetings and activities, this project will enhance the capability in absorbing research knowledge from other global players on the forefront of research, and will increase the potential for the development of transformative research ideas. It will also act as a meeting place where individuals from all the stakeholders can locate possible partners, make announcements, and share ideas related to wireless research, including industry organizations, federal agencies, government laboratories and academic institutions. The focus of the institute is on dynamic spectrum access and related technologies, which is a topic of national priority to both countries, and will benefit from collaborative international science research activities.

The virtual institute will provide an environment for creative international collaboration that will leverage the synergies and resources for research and education in the two countries in order to accelerate the rate of development of research innovations and the development of talent and work-force capable of excelling in the a new highly interconnected world. The technical focus of the institute, wireless spectrum efficiency, intellectually aligns along the interests of researchers in the two countries, as well as the countries national priorities. The institute employs a number of activities including: (a) a web portal that provides services and content to participants, (b) physical and virtual PI meetings, (c) physical and virtual student investigator meetings, (d) yearly summer schools and (e) graduate student exchange.

Radio frequency spectrum is finite and yet inefficiently used -- resulting from prior policy regimes that dispensed spectrum via methods initially such as administrative allocation and later via market mechanisms such as auctions. Accordingly, a key imperative today is to enable Spectrum Sharing whereby new services are allowed to operate in bands hitherto allocated to licensed incumbents (primary users) under new sharing rules, driven by a Presidential mandate directing 500 MHz currently held by various Federal networks to be re-purposed by 2020 for civilian use. A key enabler of any engineering solution for the above is deployment of (low cost) hardware in conjunction with appropriate networking and storage resources and a software infrastructure that allows for persistent monitoring of spectrum usage. This pilot project will produce the first calibrated large-scale data sets (over frequency, time and region) of spectrum usage archived for post-processing. Such a database will be a unique national resource for any future spectrum engineering efforts; its impact will extend well beyond the academic community. The data-driven research that it enables will provide valuable inputs for spectrum policymakers charged with formulation of new spectrum sharing rules.

This project significantly extends the state-of-the art in spectrum monitoring: first and foremost, it will result in the first wide-area, persistent and taskable spectrum monitoring and data collection infrastructure without using expensive high-end sensors, but still capable of gathering unprecedented amount of good quality spectrum data that will be stored and made publicly available for further investigations by research community. Further, the design will constitute the first step towards future networked monitoring infrastructure that can allow for distributed experimentation by researchers who will have the ability to task desired sensor sub-sets simultaneously for data acquisition in desired spectrum bands. This will enable data mining of spectrum usage patterns as a function of both space and time, which is currently not possible.

Radio cosmology is one of the major goals of the US radio astronomy community and has the potential to reveal the birth of the Universe's first stars, measure Dark Energy, and reveal the history of galaxy formation. The signal from the distant universe is extraordinarily faint, a thousandth of a billionth of a billionth of a billionth of a Watt. The important signals are found in the commercial broadcast bands. In comparison reflections of TV and radio transmissions off the moon is quite bright. This research will find and remove the very faintest man-made radio interference from sources such as space junk reflections and over-the-horizon atmospheric refraction (inverse mirages). In addition, this research will develop and release open source software to help remove ultra-faint Radio Frequency Interference (RFI) at any radio telescope around the world. This grant will also expand the University of Washington Community College Transfer Program that uses undergraduate research to help community college students transfer to four year universities and major in physics or engineering, naturally increasing the gender balance and diversity of these STEM fields.

Radio Cosmology is the grand challenge of modern radio astronomy "Epoch of Reionization" observations, which were the goal of the highest priority mid-scale project identified by the Radio, Millimeter, and Submillimeter Panel of the Astronomy and Astrophysics Decadal Survey. There has been great progress in developing the instruments and analysis techniques needed to measure these extraordinarily faint signals from the distant universe. The investigators will develop the tools for identifying and removing ultra-faint RFI, demonstrate the new techniques on Epoch of Reionization data, and freely release the code to the astronomical community.

As a part of this proposal, the investigators will build on the very successful Community College Transfer Program developed by one of the investigators, expanding it to include electrical engineering as well as physics students. They will recruit 4 students a year to focus on the performance of the antenna and proposed digital upgrades. The investigators will install an antenna and have undergraduate students investigate non-linear interactions between the hardware, digital system and RFI.

There is a pressing need for more efficient use of existing spectrum to sustain the explosive growth in wireless data. The two most common and widely used broadband wireless access networks are cellular and Wi-Fi which traditionally have operated in very different spectrum regulatory domains: cellular over licensed spectrum allowing exclusive use whereas Wi-Fi has been designed for the unlicensed bands where there is no interference protection by rule. This difference has led to fundamentally different system architectures: cellular systems are centrally controlled where users are allocated resources in frequency and/or time in a way so as to minimize intra-cell and inter-cell interference. Wi-Fi on the other hand, has been designed to operate in an environment where interference between like and unlike systems must be tolerated. Of late, there has been increasing interest in deploying systems originally intended for licensed, cellular bands in the unlicensed bands that are currently primarily used by Wi-Fi, with minimal changes. This creates a new and largely under-explored heterogeneous interference scenario: a scheduled system (cellular) coexisting with a collision avoidance protocol (Wi-Fi). Currently, multiple coexistence solutions have been proposed by industry players, often reflecting existing vested interests and selective use-cases and test scenarios that promote one side or the other. An unbiased study of these various solutions is necessary to settle the ongoing debate on this issue, and can have vital impact on the usage of a large swath of spectrum under consideration.

In this project, this fundamental coexistence problem between dissimilar systems will be studied in an unbiased manner, using analysis, simulation and experiments. The research will have three main thrusts and a parallel experimental plan that focuses on system level simulation complemented by a hardware test-bed. Prior to developing schemes for fair sharing, the very concept of fairness needs to be defined suitably. This will be the focus of the first thrust where air-time, throughput and access are the fairness metrics that will be evaluated. The second and third thrusts will propose, analyze, simulate and test coexistence schemes that cellular systems can deploy to ensure fair sharing with Wi-Fi, and that Wi-Fi can deploy to ensure fair sharing with cellular. The latter research area is necessary since in the unlicensed spectrum Wi-Fi does not have any priority over other systems as long as both obey the the Federal Communications Commission rules. The experimental software and hardware platforms will be used to test the coexistence schemes developed in the project. The results of the project, including software code and data sets, will be made public on an ongoing basis and also be used to influence standardization and regulations governing coexistence in the unlicensed bands.

The open source network simulation (ns-3) tool is used widely by researchers to evaluate the performance of computer networks. Over the past decade, user demand for new ns-3 capabilities has centered on simulating rapidly emerging wireless networking technologies including Wireless Fidelity (WiFi) and Long Term Evolution (LTE) cellular systems. New capabilities are essential for exploration of emerging 5th Generation (5G) cellular network technologies.

This project seeks to 1) extend the core wireless capabilities of ns-3, positioning the simulator as the research tool of choice for 5G wireless network simulations; 2) improve usability and create new educational/training materials; and 3) better align ns-3 with experiments on wireless network test-beds. The latter project goal is expected to contribute to recently announced National Science Foundation-funded Platforms for Advanced Wireless Research (PAWR) city-scale advanced wireless infrastructure testbeds. New wireless technology coexistence scenarios for heterogeneous networks as well as the ongoing challenge of scaling due to network densification are main research thrusts for this effort. In addition, a key project goal is improving usability and development of new ns-3 educational material to ease adoption of these new modules (and ns-3 broadly) by the next generation of users. The project extends an existing collaboration between investigators at the University of Washington and the Centre Technologic Telecomunicacions Catalunya (CTTC Barcelona).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Simulation of emerging next-generation wireless networks continues to be an invaluable component of the design, evaluation and innovation cycle as a complement to other modes such as testbeds of performance testing. This project will focus on upgrading ns-3, the most widely used open source network simulator, to meet the challenges of efficient yet accurate simulation based performance evaluation of 5G and beyond networks. It will do this via model building for the evolutions in Wi-Fi (notably Wi-Fi 6) and cellular (notably 5G NR) technologies and incorporating new simulation techniques targeting dense and heterogeneous network use cases.

Network simulation faces fundamental challenges due to inherent increases in complexity, notably at the physical layer due to increasing bandwidth, MIMO (multiple-input, multiple-output) and multi-user operation as well as cross-layer (physical and multiple access) operation, necessary to deal with network scale and heterogeneity. The primary objective is to develop simulation methods that achieve the desired balance between maintaining simulation run-time efficiency while preserving accuracy of measured network parameters (loss, throughput, latency) - in the face of increasing complexity. The research plan will explore a variety of techniques including efficient link-to-system mappings, pruning of network state representations that do not impact simulation accuracy, and parallelization approaches based on optimistic simulation.

In addition, the project plans to improve ns-3 usability and further adoption through increased community outreach and creation of new educational material to lower barriers to entry for a new generation of ns-3 users. The recreated ns-3 Consortium hosted by the University of Washington will foster creation of training material for both novice and advanced users, to be archived and distributed online as well as in-person at leading networking/simulation conferences.

New content (educational materials and tutorials, research reports and publications) will be disseminated primarily via the ns-3 website https://www.nsnam.org/ and the two institutional lab home pages (the University of Washington - https://depts.washington.edu/funlab and Georgia Tech - http://blough.ece.gatech.edu/research/) along with other popular channels such as YouTube/Viemo for video. Additionally, code under development will be preserved in archives such as Gitlab and announced via the ns-3 Users and Developers mailing lists.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.