RESEARCH

2016-2023

ASTRO: Autonomous and Tetherless Networked Drone Missions

Designed and implemented a system for data-driven drone sensing missions (ACM TIOT 2021), localizing, and approaching RF targets (IEEE Internet Things J. 2022).

2014-2020

Millimeter Wave WLANs

Designed and implemented the first mmWave WLAN with out-of-band beam steering (IEEE INFOCOM 2015), beam-width adaptation (ACM MobiHoc 2016), and multi-stream MIMO (ACM MobiCom 2018).

2014-2018

Uplink Multi-User WLAN.

Discovered severe degradation of TCP downlink throughput when a MU-MIMO downlink is not paired with a MU-MIMO uplink (IEEE/ACM Transactions on Networking 2019) and designed a scalable uplink multi-user MIMO WLAN (NSDI 2016).

2011-2019

Wireless Security in MIMO and Massive MIMO

Evaluated DoS and security threats to wireless networks and discovered fundamental limits of using CSI as a shared secret (IEEE INFOCOM 2012 and ACM MobiHoc 2017) .

2010 – 2017

Visible Light Communication Systems

Designed and implemented a vehicular VLC system with applications to Internet access, vehicle-to-vehicle communication, and safety (ACM VANET 2011) and developed a joint light-radio WLAN architecture (IEEE SECON 2017).

2010 – 2015

 Sub GHz Spectrum and New Access Techniques.

Sub GHz Spectrum and New Access Techniques. Demonstrated UHF-band MU-MIMO (ACM MobiCom 2014) and an opportunistic Wi-Fi channel sounding technique (ITC 2016).

2009 – 2011

Multi-User MIMO WLAN

Implemented the first multi-user MIMO WLAN and demonstrated simultaneous transmission to users separated by centimeter-scale distances (ACM MobiCom 2010).

2006 – 2013

Diverse Spectrum Access

Developed underlying theory and algorithms (IEEE/ACM Transactions on Networking 2007) and a prototype spanning 500 MHz to 5 GHz (IEEE INFOCOM 2013).

2007 – 2008

Vehicular Wi-Fi

Demonstrated vehicular Wi-Fi handoffs in 200 meter radius urban Wi-Fi cells (ACM MobiSys 2008).

2005 – 2008

Wi-Fi Modeling

Developed the first model of CSMA-based contention that characterizes starvation arising from topological and channel asymmetries (IEEE INFOCOM 2006).

2004 – 2008

Mesh Fairness and 802.11s

Designed and implemented mechanisms, algorithms, and theoretical framework for fair bandwidth distribution over multi-hop wireless networks (ACM MobiCom 2004).

2003 – 2008

Wireless for Under-served and Under-resourced Communities

Designed and deployed urban-scale wireless networks to serve previously unreached populations (Journal of Urban Technology and Technology For All Wireless).

2003 – 2008

Multi-Tier Mesh Access Networks

Architected, designed and implemented the Technology For All wireless network, the first mesh network with all Wi-Fi access, backhaul, and capacity tiers (ACM MobiSys 2006).

2003 – 2006

Clean Slate Design of Wireless Protocols

Designed and implemented a software-defined-radio (SDR) FPGA based platform for clean-slate design of wireless protocols and algorithms (HotNets 2003 and MC2R).

2002 – 2005

Opportunistic Multi-Rate Wi-Fi

Designed and evaluated opportunistic rate adaptation that scales the amount of data transmitted to the channel rate, using frame aggregation to equalize time shares for time-share fairness (ACM MobiCom 2002). This project yielded the first WLAN implementation of per-packet channel-based rate adaptation.

2002 – 2005

Internet Denial of Service

Demonstrated underlying vulnerabilities of TCP to low-rate attacks (ACM SIGCOMM 2003) and peer-to-peer networks to pollution attacks (ACM SIGMETRICS 2005).

2001 – 2005

Cloud Resource Management

Designed and implemented content distribution and access management system for distributed and multi-site Internet Data Centers (IWQoS 2002).

1994 – 2000

Quality of Service in Packet Switched Networks

Developed foundations for deterministic performance guarantees for real-time traffic (ACM SIGMETRICS ’95) and scalable techniques for Internet quality-of-service management (SIGCOMM 2000).