Some previous projects
- Mobile and Sensor Computing
- CarTel, a mobile sensor
system motivated by vehicular and transportation applications. CarTel
applications can collect, process, deliver, analyze, and visualize
data from sensors located on mobile units such as automobiles and
smartphones. Component projects include accurate delay estimation
and CTrack); the
content delivery network for vehicles using opportunistic WiFi for
connectivity; predictive delay modeling and traffic-aware stochastic
routing (soon available on the iPhone as iCartel); various
protocols for tolling, insurance, and statistics gathering; the
Patrol road surface monitoring system; etc.
- Cricket, an indoor
location system for embedded sensor & mobile context-aware
applications. Cricket provides the hardware, software-based
algorithms, and a software API for applications to discover their
logical location (e.g., which room or portion of a room they are
in), position coordinates (e.g., indoor GPS coordinates), and
orientation (the Cricket compass). The Cricket design and software
are available under open source, and the hardware is available
- System software for "truly mobile" devices including:
- Network architecture
- Mosh, the mobile shell, an example
of a "first-principles" architecture for interactive remote terminals.
- Alfalfa, a system for
interactive videoconferencing over wireless cellular networks, another
example of a gracefully-mobile application (this one is high-bandwidth
and low-delay, whereas Mosh is low-delay but not as
- Developing elements of Internet architecture using flat names as a
fundamental building block. Builds on some lessons
learned in Project IRIS. In particular:
- SFR: Treating data as
- DOA: Treating middleboxes as first-class citizens.
Internet routing (e.g., fault detection in routing
configuration using the rcc tool, verifying Internet routing,
stable Internet routing, rethinking BGP and new routing
architectures, router configurations, etc.).
- Migrate, an
session-based architecture for Internet mobility (including
suspend/resume) and TCP connection migration.
- DNS analysis.
- CM, the
Congestion Manager, an integrated end-to-end congestion
management architecture for the future Internet. In addition to
the architecture, this project developed binomial congestion
control, analyzed congestion control under dynamic conditions,
investigated congestion state sharing schemes, and developed
some new adaptive applications, including OxygenTV
(in 2000-01) for wireless MPEG-4 delivery.
- TESLA, a
toolkit for building transparent session-layer services.
- DDoS, spam control, intrusion detection
- Overlay and peer-to-peer networks
Resilient Overlay Networks, to improve end-to-end communication
availability among a group of cooperating nodes and MONET, Multi-homed
Overlay Networks, to improve the end-to-end availability of access to
Web sites from Internet clients.
- Chord, a scalable
lookup protocol to implement a distributed hash table (DHT).
- The IRIS (Infrastructure for
Resilient Internet Systems) project advocates the design and
deployment of large-scale resilient distributed systems on the
Internet using flat names as the fundamental abstraction. The ability
to scalably and reliably resolve flat names using DHTs enables IRIS.
I've worked on the Chord protocol, analysis of DHTs under node churn
(the notion of "half-life" of P2P systems), and DHT-based services
- SFR (Semantic-Free
Referencing), a proposal to untangle the Web from DNS.
(Delegation-Oriented Architecture), an extension to the Internet
architecture in which senders and receivers direct traffic through
intermediaries with a delegation primitive. The goal is to
accommodate middleboxes in an architecturally coherent way.
- Infranet, a
system for circumventing Web censorship and surveillance.
- INS, the
Intentional Naming System, in which entities are named by "what"
attributes they provide (rather than "where" they are in the
- Wireless and sensor networks
- MRD, a Multi-Radio
Diversity system to improve throughput and loss rates in wireless networks.
- Fusion, a congestion
control scheme for wireless sensor networks.
- Sift, A MAC
protocol for event-driven wireless sensor networks.
- MistLab, a sensornet
testbed. Now open for public use and experimentation.
Bounded SlowDown protocol for minimizing energy for Web access on
wireless (Wi-Fi) clients.
- Span, an energy-efficient
topology formation protocol for ad hoc networks.
- LEACH and SPIN,
energy-efficient clustering and information dissemination protocols
for wireless sensornets.
a tool that automatically generates header compression code from
protocols for internetworking with Bluetooth.
- Wireless TCP improvements and TCP over asymmetric networks. Software (unmaintained and unsupported).
- Data management systems
- CryptDB, a system to run
SQL over fully encrypted data without requiring clients to perform any
query processing themselves.
- HRDB, a Heterogeneous Replicated Data Base system
that provides high availability by replicating different
implementations of a SQL DBMS (e.g., Postgres, MySQL, Oracle, and DB2
could form the replicas). (No modifications to these replicas is
- Medusa, a
large-scale distributed streaming database system that provides a stream processing
framework for sensor data streams, and its follow-on project, Borealis.