August 21, 2017

Engineering Egress with Edge Fabric: Steering Oceans of Content to the World

ACM SIGCOMM

Large content providers build points of presence around the world, each connected to tens or hundreds of networks. Ideally, this connectivity lets providers better serve users, but providers cannot obtain enough capacity on some preferred peering paths to handle peak traffic demands. These capacity constraints, coupled with volatile traffic and performance and the limitations of the 20 year old BGP protocol, make it difficult to best use this connectivity. This paper presents Edge Fabric, an SDN-based system we built and deployed to tackle these challenges for Facebook, which serves over two billion users from dozens of points of presence on six continents.

Brandon Schlinker, Hyojeong Kim, Timothy Cui, Ethan Katz-Bassett, Harsha V. Madhyastha, Italo Cunha, James Quinn, Saif Hasan, Petr Lapukhov, James Hongyi Zeng
July 21, 2017

Proton Testing Results for Kaman KD-5100 Differential Inductive Position Measuring Systems

Journal, IEEE Radiation Effects Data Workshop (REDW), in press

We report proton testing of a position measuring system, the Kaman KD-5100, with applications including mirror positioning for laser beam control. We measure a device response likely due to total ionizing dose and/or displacement damage.

Bart McGuyer, Randall Milanowski, Slaven Moro, Norman Hall, Bert Vermeire
July 21, 2017

Robocodes: Towards Generative Street Addresses from Satellite Imagery

CVPR 2017

This paper describes our automatic generative algorithm to create street addresses (Robocodes) from satellite images by learning and labeling regions, roads, and blocks. 75% of the world lacks street addresses.

Ilke Demir, Forest Hughes, Aman Raj, Kleovoulos Tsourides, Divyaa Ravichandran, Suryanarayana Murthy, Kaunil Dhruv, Sanyam Garg, Jatin Malhotra, Barrett Doo, Grace Kermani, Ramesh Raskar
July 17, 2017

100/200 Gbps Optical Coherent DSP ASIC – SEE & TID Assessment

NSREC 2017

Experimental assessment of commercial 100/200 Gbps optical coherent DSP modem ASIC completed with 64 MeV and 480 MeV proton radiation test campaigns. Single event effect cross sections calculated and no performance degradation observed for proton fluence levels up to 1.27×10^12 p/cm^2 with equivalent total ionizing dose exposure to 170 krad(Si).

Raichelle Aniceto, Slaven Moro, Randall Milanowski, Christopher Isabelle, Norman Hall, Bert Vermeire, Kerri Cahoy
July 17, 2017

Single Event Effect Assessment of a 1-Mbit Commercial MRAM

2017 Nuclear and Space Radiation Effects Conference (NSREC) Radiation Effects Data Workshop

Single event effect susceptibility of a 1-Mbit commercial MRAM was experimentally evaluated. The memory exhibited SEFIs when operated in a dynamic mode with an LET threshold of 2.29 MeV.cm2/mg and a saturated cross section of 2.2×10-4 cm2/device. The memory was not sensitive to SEL, SEU or MBUs.

Philippe C. Adell, Slaven Moro, Lionel Gouyet, Christian Chatry, Bert Vermeire
June 15, 2017

Formulation of Aerial Platform Environmental Requirements from Global Radiosonde Data

Journal of Unmanned Vehicle Systems

This paper demonstrates how raw observational climate data can be processed to characterize global climate histories and statistics for the formulation of aerial platform environmental requirements.

Jacob Stelman, Zhang Liu
March 2, 2017

On user and traffic distribution for extreme rural scenario

Radio Access Network, November 2016

In this contribution, we leverage new research results and data [5] – population density data – that provide a high-resolution view into global population density distributions.

Ali Panah
February 1, 2017

Optimal User Loading in Massive MIMO Systems With Regularized Zero Forcing Precoding

IEEE Wireless Communications Letters

We consider a downlink massive multiple-input multiple output system employing regularized zero-forcing precoding. We derive the asymptotic signal-to-leakage-plus-noise ratio (SLNR) as both the number of antennas and the number of users go to infinity at a fixed ratio.

Sungwoo Park, Jeonghun Park, Ali Yazdan Panah, Robert W. Heath Jr
February 1, 2017

Optimal User Loading in Massive MIMO Systems with Regularized Zero Forcing Precoding

IEEE Wireless Communications Letters

We consider a downlink massive multiple-input multiple output system employing regularized zero-forcing precoding. We derive the asymptotic signal-to-leakage-plus-noise ratio (SLNR) as both the number of antennas and the number of users go to infinity at a fixed ratio.

Sungwoo Park, Jeonghun Park, Ali Yazdan Panah, Robert W. Heath Jr
December 6, 2016

Feedback Neural Network for Weakly Supervised Geo-Semantic Segmentation

Arxiv

We propose a novel neural network architecture to perform weakly-supervised learning by suppressing irrelevant neuron activations. When applied to a practical challenge of transforming satellite images into a map of settlements and individual buildings it delivers results that show superior performance and efficiency.

Xianming Liu, Amy Zhang, Tobias Tiecke, Andreas Gros, Thomas S. Huang
December 6, 2016

Population Density Estimation with Deconvolutional Neural Networks

Workshop on Large Scale Computer Vision at NIPS 2016

This work is part of the Internet.org initiative to provide connectivity all over the world. Population density data is helpful in driving a variety of technology decisions, but currently, a microscopic dataset of population doesn’t exist. Current state of the art population density datasets are at ~1000km2 resolution. To create a better dataset, we have obtained 1PB of satellite imagery at 50cm/pixel resolution to feed through our building classification pipeline.

Amy Zhang, Andreas Gros, Tobias Tiecke, Xianming Liu
July 19, 2016

Luminescent detector for free-space optical communication

Optica 3, 787-792 (2016)

We show that fluorescent materials can be used to increase the active area of a photodiode by orders of magnitude while maintaining its short response time and increasing its field of view.

Thibault Peyronel, Kevin Quirk, Tony Wang, Tobias Tiecke
April 12, 2016

Performance of Regression-Based Precoding for Multi-User Massive MIMO-OFDM Systems.

EURASIP Journal on Advances in Signal Processing

We study the performance of a single-cell massive multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system.

Ali Yazdan Panah, Karthik Yogeeswaran, Yael Maguire
March 8, 2016

Two-Axis Gimbal for Air-to-Air and Air-to-Ground Laser Communications

Facebook

For bi-directional links between high-altitude-platforms (HAPs) and ground, and air-to-air communication between such platforms, a hemispherical +30° field-of-regard and low-drag low-mass two-axis gimbal was designed and prototyped.

Amnon Talmor, Harvard K Harding Jr, Chien-Chung Chen