Joseph E. Ford - US grants

The proposed project will investigate a broad class of packet-based network architectures, protocols, and services where the core switch/route fabric has limited or no buffering capability. These networks - called mbuffered networks - have two distinguishing features. First, packet loss due to contention is treated as an erasure that can be corrected via coding techniques. Information is encoded into code words and each codeword is divided into fragments. The redundancy built into the codeword acts like a "virtual buffer" that mitigates contention and packet loss so that if several of the codeword fragments are erased as they pass through the network, there is still a high probability that the information within the codeword can be decoded correctly at the destination. Adaptive flow control can be implemented by adjusting the coding overhead (code rate) as well as the fragment generation rate. The second distinguishing feature is the robustness with respect to hardware and routing failures. In particular, different codeword fragments belonging to the same codeword can be sent using different routes within the network to increase resilience. Route diversity also provides unique security and authentication features.

The intellectual merit of the proposed project is the exploration of new architectural approaches that use little or no buffering in high-speed networks where buffers are becoming increasingly difficult to implement. Results of this project will impact research directions in optical systems technology, and increase the base of knowledge in communication systems theory. The project will provide unique training of both undergraduate and graduate students in a systems-oriented multi-disciplinary effort.

This project, building a campus wide ultra high-speed optical fiber network that supports scientific application and experiments of high volume data, develops an experimental next-generation instrument to efficiently investigate and compare campus-scale terabit-class lambda network architectures that span from optical-circuits-only to packet-switched-only networks (and a range of hybrid combinations in between). Current commercial approaches to storage systems do not scale in either performance levels or data abstractions. The proposed approach builds on the foundation of the shared-nothing compute cluster emerging from data systems, visualization walls, and high-end instrument interfaces, having raw horsepower to serve and ingest high volumes of data required by applications. Constructing a next generation switch for simultaneously switching 10Gbs streams efficiently, the work aims at building a 21st century photonic instrument to explore the practical tradeoffs of network and application design in bandwidth-rich infrastructure. Supporting large scientific problems and enabling big simulations, the project constructs Quartzite, the experimental, next-generation instrument. While fostering comparative studies, Quartzite, a data-intensive application breadboard, enables stitching together resources, bringing them virtually in. Thus, this wavelength-selective switch creation, communication and delivery project, adds hybrid-networking structure to a unique campus-scale platform and enables the study of network architecture and application design in a band-width-rich infrastructure and the sharing of large data sets across clusters. The work involves high risk, with a promise of even higher impact, since data intensive scientific exploration can be brought into the scientists' lab, by using on-demand high-speed data flows to harness campus- to international-scale resources. The work explores the following issues:
How surplus of on-demand bandwidth can be exploited by end user applications,
How distributed systems can be best architected,
When is a non-shared packet network needed,
How should control of a hybrid fabric be handled,
Can applications truly exploit a high-speed parallel infrastructure,
Is dynamic reconfiguring of campus network to meet transient capacity demands practical,
Is it beneficial to expose direct circuits to individual endpoints, and
Do novel packet scheduling strategies for shared links dramatically improve the capacity.
Broader Impact: The Quartzite-enabled comparisons will influence the network structure of future research university networks, greatly increasing the capability for data-intensive research throughout the country. Working with industrial partners, the hybrid Quartzite core system and software will service us all.

A multidisciplinary team from the University of California, San Diego (UCSD), specializing in the fields of nanophotonics, nanooptics, optoelectronics, and material science and material processing are collaborating in developing Integrated Nanoscale Materials, Devices and Systems with special focus on Nanophotonics for Optical Delay Engineering (NODE). The aim of the project is to demonstrate chip-scale realization of multistage optical delay architectures using nanoscale photonic materials and devices in a waveguide configuration, taking advantage of the polarization degree of freedom. The largest thrust will be on investigation of resonant phenomena in nanophotonic optical components placed in proximity to each other and demonstration of their integration into Nanoscale Devices-and-System Architectures realizing programmable optical delays which are crucial for numerous applications including optical buffering for large optical data routing systems, true time delay phased arrays, and general digital optical signal processing architectures. Research efforts in methodology, design, fabrication and characterization of nanophotonic materials, devices and systems will be useful for students and researchers in the fields of nanophotonics, advancing the fundamental understanding of the near field resonant and nonresonant interactions between nanoscale devices, and enabling their effective integration with novel functionalities. We will also establish innovative education and outreach projects with the UCSD's Preuss School, designed for students in 6-12 grade coming from disadvantaged households.

Proposal Number: ECCS-0844274
Proposal Title: SGER: Reactive Solar Concentrators
PI Name: Ford, Joseph E.
PI Institution: University of California-San Diego
Objective: The PI has developed a new approach to concentrating solar light, by using fixed sheets of material which could be put up on a rooftop, and which send light to the edges of the material, where high efficiency solar cells can be used to convert the light to electricity. The "material" is really a solid state structure made up of microlenses which can track the angle of the sun by use of optical effects instead of the more cumbersome physical tracking systems used today in conventional concentrating solar power. Preliminary calculations look favorable. The task now is to begin validating the concept, by evaluating and implementing alternative ways of realizing it.

Intellectual Merit: From an engineering viewpoint, developing a new family of technology is a fundamental achievement of great merit.

Broader Impacts: The primary benefit of this project, if successful, would be to rooftop solar power. Studies of rooftop solar power claim that the roofs in the US could supply about 60% of peak electricity demand, and about 25% of total 24-hour demand, assuming today?s 10-15% efficient solar cells. Multilayer or "tandem" solar cells have gotten to efficiencies in the 35-50% range, but are expensive to make and to install over large areas. Flexible thin film solar cells are much more affordable a key factor driving their deployment in the market but are struggling to get to 10% in the future. If this new type of technology leads to flexible, affordable easily-deployed sheets which double the electricity one can get from rooftops, the benefits could be enormous. At best, it could let us meet half the nation?s needs in a carbon-free manner, at a price that would support its actual deployment. Considerable R&D will be needed to evaluate this important but risky hope.

Ever-larger data centers are powering the cloud computing revolution, but the scale of these installations is currently limited by the ability to provide sufficient internal network connectivity. Delivering scalable packet-switched interconnects that can support the continually increasing data rates required between literally hundreds of thousands of servers is an extremely challenging problem that is only getting harder. This project leverages microsecond optical circuit-switch technology to develop a hybrid switching paradigm that spans the gap between traditional circuit switching and full-fledged packet switching, achieving a level of performance and scale not previously attainable. This will result in a hybrid switch whose optical switching capacity is orders of magnitude larger than the electrical packet switch, yet whose performance from an end-to-end perspective is largely indistinguishable from a giant (electrical) packet switch.

The research provides a quantitative baseline for hybrid network design across a wide range of present and future technologies. The project will consist of five parts: i) traffic characterization to identify the class of network traffic that a circuit switch can support as well as the partitioning of the traffic between the circuit and packet portions of the network; ii) circuit scheduling to enable the circuit switch to rapidly multiplex a set of circuits across a large set of data center traffic flows; iii) traffic conditioning to reduce the variability of traffic at the end hosts, easing the demands placed on switch scheduling; iv) a prototype hybrid network that can use an optical circuit switch that operates three orders of magnitude faster than existing solutions; and v) a trend analysis to understand the tradeoffs resulting from potential future technology advances.

The work stands to dramatically improve data center networks, significantly reducing operating costs and increasing energy efficiency. The research material will be incorporated into courses, helping to train the next generation of computer networking scientists and engineers. The PIs will also continue ongoing outreach to high school students, both through the UCSD COSMOS summer program and through talks delivered at local high schools.

This project targets the development of monocentric camera systems for high-resolution, wide field-of-view (FOV) light field imaging in small device form factors. Building on the benefits of recently-developed monocentric optics - ultra-high resolution, small physical footprint, low weight, and high light collection - monocentric light field imagers provide a transformative platform for a range of future experiential imaging and computing applications. In particular, light field-enabled monocentric optics allow for spatially-varying digital focus for complex and wide FOV scenes, 3D imaging capabilities, stereo view synthesis, and imaging through partial occluders. As opposed to any existing technology, monocentric light field imagers enable immersive content for emerging head-mounted displays with support for focus cues to be captured with low-cost, mobile devices. A range of computer vision algorithms directly benefit from the targeted computational imaging platform, including 4D feature detection, localization and mapping, segmentation, recognition, tracking, depth estimation, matting, object removal, and hole filling. The developed monocentric light field imaging system provides benefits for society at large; the enabled 3D image capture and editing capabilities offered in a small device form factor could profoundly impact future means of inter-personal digital communication, remote collaboration and education as well as remote operation of vehicles. Newly-developed computer vision algorithms are beneficial for navigation of autonomous vehicles. Live content for a range of applications can be easily recorded and edited, for example for simulation, training, phobia treatment, and cultural heritage. Light field optics and algorithm design will be tightly integrated into the syllabus of multiple graduate-level courses at Stanford and UCSD and made available to industry professionals via online learning platforms.

This research investigates a viable solution for these challenges and provides a next-generation computational imaging platform. Leveraging the expertise of PIs from University of California San Diego and Stanford University, this project aims at (i) designing and fabricating a wide field of view light field imager via monocentric optics, conformal microlenses, and fiber coupling, (ii) developing end-to-end computational imaging pipelines, from coded capture to display on emerging head mounted displays, and (iii) evaluating computer vision and scene understanding algorithms, including feature detection, localization, mapping, segmentation, classification, tracking, matting, classification, and object removal. The research question driving this project is the quest for a small, computational imaging system that is flexible enough to unlock a range of visual and experiential computing applications that cannot be easily provided by cameras available today. Monocentric optics offer great benefits for such applications: wide field of view, high resolution, high light collection, and a small form factor. Yet, future visual computing applications require even more functionality: 3D imaging, adaptive digital focus over a large FOV, compatibility with emerging virtual and augmented reality displays, enhanced image editing modes, such as object segmentation, removal, insertion, localization, and more.