Portrait of Venkat Padmanabhan

Venkat Padmanabhan

Principal Researcher



Received the Shanti Swarup Bhatnagar Prize for Science and Technology (Sep 2016)

Elected Fellow of the ACM (Dec 2016)

RADAR paper selected for the inaugural ACM SIGMOBILE Test-of-Time Award (Apr 2016)

Chairing the 2017 ACM SIGMOBILE Test-of-Time Paper Award committee

Kwikr (part of the PinDrop project) received Best Corporate Demo Award at COMSNETS 2017


I am a Principal Researcher at Microsoft Research India, where I founded the Mobility, Networks, and Systems group in 2007. I was previously with Microsoft Research Redmond for 8½ years. Before that, I obtained a Ph.D. in Computer Science from the University of California at Berkeley in September 1998. Professor Randy Katz was my advisor, having previously obtained an M.S. in Computer Science also from UC Berkeley in 1995 (advised by Professor Domenico Ferrari) and a B.Tech. in Computer Science and Engineering from the Indian Institute of Technology, Delhi in 1993.

My research interests lie broadly in mobile and networked systems. My current work centers on the intersection of sensor systems and mobile computing, and on efficient mobile communication. My past projects have spanned a range of areas, including network measurement, wireless networking, RFID, geolocation, network tomography, and peer-to-peer networking. The technologies developed in some of these projects (e.g., the ProbeGap bandwidth probing tool and the GeoCluster technique for learning IP-location mapping) have been transferred to Microsoft’s product groups while others (e.g., the RADAR WLAN-based user localization system) have been made available through Microsoft’s technology licensing program.

I am an INAE Fellow, IEEE Fellow, and ACM Fellow. I am a recipient of the 2016 Shanti Swarup Bhatnagar Prize for Science and Technology. I have served both as General Co-Chair of the ACM SIGCOMM conference (in 2010 in New Delhi) and as Program Co-Chair (in 2012) and also served on the editorial board of ACM SIGCOMM Computer Communication Review, IEEE/ACM Transactions on Networking, and IEEE Transactions on Mobile Computing. I have served on and chaired the ACM SIGCOMM Technical Steering Committee. At present, I am serving on the ACM SIGCOMM Industrial Liaison Board.



Established: May 28, 2015

The PinDrop project focuses on building the substrate for supporting high-quality real-time streaming over wired and wireless networks. Context Real-time streaming across the wide-area network (WAN) is key to several existing and anticipated services, including voice and video conferencing (e.g., Skype, Viber), remote console access (e.g., remote desktop, VNC), remote application streaming (e.g., Azure RemoteApp), and cloud-based gaming. A common characteristic of these services is bidirectional interactive communication, between two or more users or between a user…

HAMS: Harnessing AutoMobiles for Safety

Established: May 1, 2015

Context Road safety is a major public health issue, accounting for an estimated 1.25 million fatalities, and many more injuries, the world over, each year, placing it among the top 10 causes of death. Middle-income and particularly low-income countries bear a disproportionate burden of road accidents and fatalities. For instance, the estimates of road fatalities in India range from one every 4 minutes to almost a quarter of a million, or 20% of the world’s…


Established: September 22, 2013

Dhwani enables information theoretically secure Near Field Communication (NFC) on existing mobile phones without requiring any special hardware or PKI infrastructure. It uses existing microphones and speakers on phones to perform acoustic NFC. It uses a novel self-jamming based physical layer security technique called SecureJam.

Phytics: Physical Analytics

Established: February 18, 2013

The goal of the Physical Analytics project, or Phytics, is to perform analytics on the physical actions of users. Such analytics would be valuable in a variety of contexts where the design of a physical space is intertwined with how users use the space, e.g., to understand the behaviour of shoppers in mall or a store, which might be indicative of their interests; to fine-tune the layout of services in an airport or a train…


Established: July 12, 2012

Many networked applications that run in the background on a mobile device incur significant energy drains when using the cellular radio interface for communication. This is mainly due to the radio-tail, where the cellular radio remaining in a high energy state for up to 20s after each communication spurt. In order to cut down energy consumption, many recent devices employ fast dormancy, a feature that forces the client radio to quickly go into a low…


Established: May 18, 2010

Energy Efficient Mobile Communication using Cloud Support Overview Cellular radio communication is a significant contributor to battery energy drain on smartphones, in some cases adding a factor of 5 or more times the energy cost of the base device. Stratus is a system that leverages resources in the cloud to reduce the energy consumed for data communication on smartphones. Using a cloud-based proxy, Stratus employs optimizations that adapt application's incoming and…


Established: December 4, 2009

Recognizing the twin trends of a rapid growth of cellular data services and the commoditization of WiFi WLAN technology, Cool-Tether proposes an architecture for ubiquitous and affordable connectivity by harnessing mobile smartphones to create WiFi hotspots on the fly. Cool-Tether optimizes heavily for battery energy consumption on the smartphones, resulting in a 38%-72% savings in energy consumption compared to prior energy-agnostic solutions for tethering.


Established: October 2, 2009

To reduce energy wastage by idle desktop computers in enterprise environments, the typical approach is to put a computer to sleep during long idle periods (e.g., overnight), with a proxy employed to reduce user disruption by maintaining the computer’s network presence at some minimal level. However, the Achilles’ heel of the proxy-based approach is the inherent trade-off between the functionality of maintaining network presence and the complexity of application-specific customization. We present LiteGreen, a system…


Established: March 1, 2009

Diagnosing Home Network Misconfigurations using Shared Knowledge The Problem Today's home network is typically a collection of several devices and applications. While the broadband modem acts as the home's window to the Internet world, there are a variety of different hardware and software components that interact within people's homes. For example, you may have a wireless router attached to your broadband modem, with several laptops and desktops connecting both through wires and wirelessly to the…


Established: December 26, 2008

RFID based enterprise intelligence The vision of the SixthSense project in the MNS group at Microsoft Research India is the workplace or home of the future where computing is extended to encompass non-computing entities such as people, objects, and spaces to enable rich user experiences. For instance, we would like users to be able to search the physical world for objects they may have misplaced or use physical events to index their experiences (e.g., "was my…


Established: December 26, 2008

The Nericell project focuses on road and traffic monitoring using an ensemble of mobile smartphones carried by people in normal course. The vision is that when a user who is participating in Nericell puts their phone in their pocket and starts driving, software on the phone will automatically monitor road and traffic conditions along their drive, and convey this information to a service in the cloud for aggregation and reporting. A…


Established: January 10, 2003

Overview The goal of the CoopNet (Cooperative Networking) project is to investigate ways in which selective use of peer-to-peer (P2P) communication can help improve the performance and/or functionality of client-server applications. CoopNet differs from many other P2P systems in a few ways: (a) P2P communication is used to complement rather than replace client-server communication, and (b) a minimal assumption is made about the willingness of peers to cooperate and the duration of such cooperation; an…


Established: November 5, 2001

RADAR is the world's first Wi-Fi signal-strength based indoor positioning system. RADAR proves that RF fingerprinting and environmental profiling with commodity wireless LAN hardware can be used to determine user and machine location inside buildings, thereby enabling indoor location-aware applications (think - "Indoor-GPS") Wherever You Go, There Is Connectivity by Suzanne Ross Victor Bahl, a researcher with the Systems and Networking group, says his kid doesn't get too excited about his work. "He's seen too…


























Venkata N. Padmanabhan’s talks

Keynote Talks

Mobile + Cloud: It Rains Opportunity
11th ACM/IFIP/USENIX International Middleware Conference, Bangalore
December 2010

Mobile + Cloud: It Rains Opportunity
4th IEEE International Conference on Internet Multimedia Systems Architecture and Applications (IMSAA), Bangalore
December 2010

Invited Talks

The Quest for Zero-Effort Indoor Localization
Carnegie Mellon University, University of California at Berkeley, IEEE ANTS 2012, Cambridge University, University College London, NIIT University, IIT Hyderabad, and University of Washington
April 2012-March 2013

Greening Desktop Computing
Bell Labs/IISc Green Telecom & IT Workshop, Bangalore
April 2012

Cloud-Supported Mobile Systems
2010 Networking Summit @ Telefonica Research, Qualcomm R&D, Hyderabad, Singapore Management University
June 2010-December 2011

WebProfiler: Cooperative Diagnosis of Web Failures
COMSNETS, Bangalore
January 2010

NetPrints: Diagnosing Home Network Misconfigurations Using Shared Knowledge
IIT Bombay, Stanford University, and HP Labs, Palo Alto
January-March 2009

Nericell: Rich Monitoring of Road and Traffic Conditions using Mobile Smartphones
IIT Delhi, Motorola Labs, University of Michigan, Ann Arbor, Northwestern University
September-October 2008

TrafficSense: Rich Road and Traffic Monitoring Using Mobile Smartphones
Princeton University, University of Washington, and University of California at Berkeley
March 2008

Improving the Network Experience of Users through Cooperation
IIT Madras, Bell Labs India, and IISc, Bangalore
May-June 2006

NetProfiler: Profiling Wide-Area Networks Using Peer Cooperation
Georgia Tech and Stanford University
February-March 2005

Bandwidth Estimation in Broadband Access Networks
University of Washington
December 2004

Impact of Interference on Multi-hop Wireless Network Performance
Institute for Mathematics and its Applications, University of Minnesota
February 2004

Resilient Peer-to-Peer Streaming
Invited talks at Carnegie Mellon University and the University of California at Berkeley
March 2003

CoopNet: Cooperative Networking
Invited talk at the Georgia Institute of Technology, Atlanta, GA, USA
September 2002

Server-based Characterization and Inference of Internet Performance
Institute for Pure and Applied Mathematics, University of California at Los Angeles (UCLA)
March 2002

Locating Internet Hosts
Computer Science Colloquium, Harvard University, Cambridge, MA, USA
June 2001

Locating Internet Hosts
University of Washington, Seattle, WA, USA
November 2000

Optimizing Internet Data Transport
Guest Lecture, Graduate Networking Seminar, University of Washington, Seattle, WA, USA
October 1999

Optimizing Internet Data Transport
BU/NSF Workshop on Internet Measurement, Instrumentation, and Characterization, Boston, MA, USA
August 1999

Addressing the Challenges of Web Data Transport
University of Washington Retreat, Whistler Resort, Canada
December 1998
(I gave a similar talk at several research labs and universities during the spring of 1998.)

Conference, Workshop, and IETF Talks

PRISM: Platform for Remote Sensing using Mobile Smartphones
ACM MobiSys, San Francisco, CA, USA
June 2010

SureMail: Notification Overlay for Email Reliability
ACM SIGCOMM Workshop on Hot Topics in Networks (HotNets), College Park, MD, USA
November 2005

NetProfiler: Profiling Wide-Area Networks Using Peer Cooperation
IPTPS, Ithaca, NY, USA
February 2005

Supporting Spectators in Online Multiplayer Games
ACM SIGCOMM Workshop on Hot Topics in Networks (HotNets), San Diego, CA, USA
November 2004

Bandwidth Estimation in Broadband Access Networks
ACM/USENIX Internet Measurement Conference (IMC), Taormina, Italy
October 2004

Supporting Heterogeneity and Congestion Control in Peer-to-Peer Multicast Streaming
IPTPS, San Diego, CA, USA
February 2004

Server-based Inference of Internet Link Lossiness
IEEE Infocom, San Francisco, CA, USA
April 2003

Secure Traceroute to Detect Faulty or Malicious Routing
ACM SIGCOMM Workshop on Hot Topics in Networks (HotNets-I), Princeton, NJ, USA
October 2002

Distributing Streaming Media Content Using Cooperative Networking
May 2002

RADAR: An In-Building RF-Based User Location and Tracking System
IEEE Infocom 2000, Tel Aviv, Israel
March 2000

TCP Performance Implications of Network Asymmetry
PILC Working Group, 46th IETF, Washington, DC, USA
November 1999

Coordinating Congestion Management and Bandwidth Sharing for Heterogeneous Data Streams
NOSSDAV ’99, Basking Ridge, NJ, USA
June 1999

Using Differentiated Services Mechanisms to Improve Network Protocol and Application Performance
IEEE RTAS Workshop on QoS Support for Real-Time Internet Applications, Vancouver, Canada
June 1999

A Proposal for SLUMS
SLUMS BOF, 44th IETF, Minneapolis, MN, USA
March 1999

TCP Fast Start: A Technique for Speeding Up Web Transfers
IEEE Globecom Internet Mini-Conference, Sydney, Australia
November 1998

Fast and Scalable Handoffs in Wireless Internetworks
ACM/IEEE Mobicom Conference, Rye, NY, USA
November 1996

A Comparison of Mechanisms for Improving TCP Performance over Wireless Links
ACM SIGCOMM Conference, Stanford, CA, USA
August 1996

Improving HTTP Latency
Second International World Wide Web Conference, Chicago, IL, USA
October 1994

Miscellaneous Talks

The Content and Access Dynamics of a Busy Web Server
MSR Networking Workshop, Cambridge, UK
January 2000

RADAR: An In-Building RF-Based User Location and Tracking System
MSR Networking Workshop, Cambridge, UK
January 2000

The Effects of Asymmetry on TCP Performance
Berkeley BARWAN Project Retreat, Lake Tahoe, CA, USA
June 1997

Direct Broadcast Satellite: Architecture and Evaluation
Berkeley BARWAN Project Retreat, Lake Tahoe, CA, USA
June 1996

Using DNS to Support Host Mobility
Industrial Liason Program (ILP), Berkeley, CA, USA
March 1996

Scalable Mobility Support for Overlay Networks
Berkeley BARWAN Project Retreat, Monterey, CA, USA
January 1996

An Architecture to Support Fast Handoffs in Wireless Networks
End of internship talk @ AT&T Bell Laboratories, Holmdel, NJ, USA
August 1995

Reducing World Wide Web Latency
End of internship talk @ Digital Equipment Corporation, Western Research Laboratory, Palo Alto, CA, USA
August 1994


Bean counting

Research highlights and impact

My research has had a significant impact on the research and academic community, with my papers having received hundreds or thousands of citations (see Google Scholar for up-to-date information), and several follow-on efforts building on my work. Some of this research has also impacted Microsoft’s products through technology transfer, and even the industry at large. Here are some highlights:

  • Indoor Localization: Worked on RADAR, the first system for indoor localization using the existing wireless LAN infrastructure. RADAR has spawned off much follow-on work in the research community, with our Infocom 2000 paper receiving over 8000 citations and being a recipient of the inaugural ACM SIGMOBILE Test-of-Time Paper Award in 2016. The method of fingerprinting invented in RADAR is the basis of many commercial WiFi-based indoor positioning systems. Followed up with more recent work at MSR India on making calibration for WiFi-based localization “zero-effort”, through a combination of a modeling-based approach to reduce dependence on ground-truth data (EZ — Mobicom 2010) and inertial tracking to generate ground truth data automatically (Zee — Mobicom 2012). Transferred technology to Windows Phone.
  • Wireless performance: Worked on one of the earliest studies of TCP over error-prone wireless LAN links, while at Berkeley (Sigcomm 1996 paper, over 2300 citations, including the journal version), and subsequently on a novel framework for estimating the capacity of wireless mesh networks, while at MSR Redmond (Mobicom 2003 paper; over 1800 citations, including the journal version). More recently, at MSR India, shifted focus to cellular network performance and its impact on battery life, with work on signal-aware communication (Bartendr — Mobicom 2010), application-aware radio management (Radio-Jockey — Mobicom 2012), and implicit coordination through cellular load sensing (LoadSense/Peek-n-Sneak — Mobicom 2013).
  • Web Data Transport: Worked on the persistent connection and pipelining optimizations to HTTP/1.0 during the early days of the World Wide Web, ideas which became part of the HTTP/1.1 standard (RFC 2616). Our WWW 1994 paper has over 450 citations (including the journal version). Also conducted one of the earliest studies of prefetching of Web content (CCR 1996 paper; nearly 800 citations). Subsequently, as part of my PhD thesis, worked on TCP-level solutions for Web data transport, including TCP Sessions and TCP Fast Start (Global Internet 1998 paper).
  • IP Geo-location: Designed a suite of novel techniques for geo-locating Internet hosts, using router labels obtained from traceroute (GeoTrace), delay measurements (GeoPing), and topology-aware clustering of web logs (GeoCluster). Published Sigcomm 2001 paper (over 530 citations), which to my knowledge, was the first paper in the academic literature on IP geo-location. Transferred technology to Microsoft ad Center.
  • Wireless Available Bandwidth Estimation: Developed the ProbeGap technique (IMC 2004 paper, over 175 citations) for lightweight yet accurate available bandwidth estimation in wireless LANs, where contention results in non-FIFO behavior across nodes. Transferred technology to Microsoft Windows. “ProbeGap” is now a term defined in the Windows Protocol Glossary on MSDN, alongside several well-known networking terms.
  • Resilient Peer-to-Peer Streaming: Proposed multi-tree-based structures for resilient P2P streaming, with multiple-description coding used to stripe content across the multiple trees, to limit disruption due to node churn. Published NOSSDAV 2002 paper (over 1200 citations) and ICNP 2003 paper (over 550 citations), which have influenced many follow-on proposals based on the multi-tree idea.
  • Smartphone-based Road and Traffic Monitoring: Developed Nericell, one of the earliest systems that used the then-anticipated sensing capabilities of smartphones for monitoring of road and traffic conditions, with particular focus on India. Published SenSys 2008 paper (over 850 citations). Nericell has inspired many follow-on efforts in India and abroad.

Some of my papers have also been included in course reading lists and research area reading lists at leading universities around the world. Here is a partial list: Berkeley, CMU, MIT, Stanford, Cornell, Harvard, Michigan, Princeton, Washington, Yale, UCL (UK), Bilkent University (Turkey), Boston University, Duke, Georgia Tech, Hong Kong University of Science and Technology, Institute for Systems and Robotics (Portugal), National Taiwan University, National University of Singapore, Purdue, Rutgers, Sun Yat-Sen University (China), UCLA, UC Santa Cruz, UCSD, UIUC, U Maryland, U Massachusetts, USC, UT Austin, U Virginia, U Waterloo (Canada), U Wisconsin.

Awards and recognitions

Keynote talks

  • 2nd Workshop on Physical Analytics (WPA) at ACM MobiSys, May 2015
  • 7th International Conference on Communication Systems and Networks (COMSNETS), Jan 2015
  • 1st International Conference on Networking Systems and Security (NSysS), Jan 2015
  • 11th ACM/IFIP/USENIX Middleware, Dec 2010
  • 4th IEEE International Conference on Internet Multimedia Systems Architecture and Applications (IMSAA), Dec 2010

Professional recognition

  • Shanti Swarup Bhatnagar Prize for Science and Technology, 2016
  • ACM Fellow, 2016, with the citation “For research contributions and professional leadership in networked and mobile computing systems
  • INAE Fellow, 2014, with the citation “for distinguished contributions to engineering
  • IEEE Fellow, 2012, with the citation “for contributions to networked and mobile computing systems” [nomination through IEEE Computer Society]
  • ACM Distinguished Scientist, 2009
  • IEEE Senior Member, 2004

Paper and Demo awards

Microsoft awards

  • President’s Runner-Up Award from the Microsoft Online Systems Division, 2013
  • Microsoft Achievement Award, 2006

Student awards

  • Charles Fish Graduate Fellowship, UC Berkeley, 1993-1994
  • Eugene C. Gee and Mona Fay Gee Scholarship for Graduate Study, UC Berkeley, 1995 (declined)
  • Motorola Undergraduate Project Award, IIT Delhi, 1993
  • Shri Pyare Lal Murgai Scholarship, IIT Delhi, 1992-1993
  • Merit Prize in each semester at IIT Delhi, 1989-1993
  • Gold Medal in the National Physics Olympiad, India, 1989
  • National Talent Scholarship, India, 1987-1993

Teaching and mentoring

I have worked with several excellent students during and after their internships at Microsoft Research. The list below is of interns I worked with while at Microsoft Research Redmond; the interns from my period at Microsoft Research India are listed on the MNS group webpage:

I have held affiliate faculty appointments in the Electrical Engineering and Computer Science & Engineering departments at the University of Washington. I taught a graduate networking class in the CSE department in Spring 2001. I am on the advisory board for the Wireless Communications Technology program at UW Extension. I have also served on student thesis committees at UW and elsewhere:

Professional service and leadership

Editorial board service

Chair positions

Program committee membership

  • ACM/USENIX MobiSys: 2007, 2011
  • ACM SIGCOMM: 2004, 2007, 2011, 2012 (co-chair), 2013, 2016
  • NSDI: 2010, 2015
  • Workshop on Physical Analytics: 2014 (co-chair), 2015, 2016
  • CoNEXT: 2006, 2009
  • ACM SIGMETRICS: 2003, 2008
  • COMSNETS: 2009
  • COMSWARE: 2008
  • ACM Mobicom: 2000, 2001, 2002
  • IEEE Infocom: 2001, 2002, 2005
  • ACM HotNets: 2005, 2011
  • ACM Internet Measurement Conference: 2002, 2005 (co-chair)
  • ACM NOSSDAV: 2000, 2002, 2003, 2004 (co-chair)
  • International Workshop on Peer-to-Peer Systems (IPTPS): 2007
  • International Conference on Distributed Computing Systems (ICDCS): 2005
  • SPIE/ACM Multimedia Computing and Networking (MMCN): 2002, 2003
  • IEEE International Conference on Network Protocols (ICNP): 2002, 2003
  • International World Wide Web Conference (WWW): 2002, 2003, 2006
  • ACM Workshop on Wireless Mobile Multimedia (in conjunction with ACM Mobicom): 1999, 2000
  • Performance and Architecture of Web Servers (in conjunction with ACM SIGMETRICS): 2000, 2001

Membership of other committees


Here are some articles on my research projects and/or recognition received: (the articles that no longer seem available online have been crossed out)

There is also a Microsoft Research article which did a profile of the research group I lead some years ago.

Here are some videos featuring my projects: