Past Projects
Transport and Congestion Control
A delay-based congestion-control algorithm that combines objective optimization with a window-adjustment rule for high throughput and low delay — with a formal analysis of when such algorithms starve.
NSDI 2018 (Copa)
Congestion Control for Wireless Networks
Transport and congestion control tuned for wireless and cellular links — loss discrimination and header compression (Snoop), capacity forecasting for interactive apps (Sprout), and explicit accelerate/brake feedback (ABC).
NSDI 2020 (ABC), NSDI 2013 (Sprout), MobiCom 2000 (Header Compression), GLOBECOM 1998 (Explicit Loss Notification), IEEE/ACM ToN 1997, MobiCom 1997 (Asymmetry), Handoffs (Daedalus), Wireless Networks 1995, MobiCom 1995
Internet Architecture and Overlay Networks
A network architecture that builds accountability into addressing, mitigating source spoofing and many denial-of-service attacks.
SIGCOMM 2008, HotNets 2007
A scalable peer-to-peer lookup protocol (distributed hash table) that maps keys to nodes with logarithmic routing — a foundation of P2P systems.
SIGCOMM 2001, IEEE/ACM ToN 2003
An overlay that routes around Internet path failures in seconds by having a small set of nodes monitor and re-route among themselves.
SOSP 2001, HotOS 2001
An end-to-end approach to host mobility that keeps connections alive across address changes and disconnections, without changing the network.
MobiCom 2000, USITS 2001
A naming system for dynamic, mobile networks where applications describe what they want by intent, and the system resolves and routes to it.
SOSP 1999, Pervasive 2002 (INS/Twine)
Datacenter, Programmable Networks, and Operating Systems
An operating-system design that reallocates CPU cores at microsecond timescales to achieve high efficiency and low tail latency in datacenters.
NSDI 2019
Data Management Systems
A database-as-a-service for the cloud with automatic workload-aware partitioning, consolidation, and encrypted storage.
CIDR 2011, SIGMOD 2011
Tolerating Byzantine faults in transaction-processing systems by running replicas of unmodified databases behind a commit-barrier scheduler.
SOSP 2007
Security and Privacy
Protecting location privacy in vehicular services (tolling, insurance, congestion pricing) while still allowing correct, auditable billing.
USENIX Security 2009, CCS 2011
Circumventing web censorship and surveillance by tunneling covert requests inside ordinary-looking HTTP traffic to cooperating servers.
USENIX Security 2002, PET 2003
AI-Driven Systems, Mapping, and Computer Vision
Mobile, Sensing, and Wireless Systems
A smart surface with thousands of tiny antennas that focuses radio signals to boost the range and reliability of low-power wireless devices.
NSDI 2020
Continuous, real-time object recognition on mobile devices by offloading the heavy computation while hiding network and processing latency.
SenSys 2015
A new family of rateless wireless codes built from hash functions, approaching capacity across a wide range of channel conditions, with a hardware decoder.
HotNets 2011, SIGCOMM 2012, MobiCom 2012
A mobile-friendly remote shell that survives roaming, intermittent connectivity, and sleep, with instant local echo — a modern replacement for SSH sessions.
USENIX ATC 2012
An indoor location system using ultrasound and RF that gives mobile devices fine-grained position and orientation, privacy-preserving by design.
MobiCom 2000, MobiCom 2001 (Compass)