Skip to main content
Sign In

College of Engineering and Applied Science

College of Engineering and Applied Sciences at UC Denver

Mobile and Networked Systems Lab (MNS)

Department of Computer Science and Engineering

Welcome to the Mobile and Networked Systems Lab (MNS) at University of Colorado Denver's Computer Science and Engineering department. MNS lab's research centers around the areas of mobile computing systems and wireless networks including mobile healthcare, mobile context discovery, mobile-centric Internet architecture, mobile system security and privacy, and mobile applications.

Demo: BiFocus - Using Radio-Optical Beacons for An Augmented Reality Search Application [PDF] 
MobiSys 2013 - Proceedings of Mobisys 2013
Ashwin Ashok, Chenren Xu, Tam Vu, Marco Gruteser, Richard Howard, Yanyong Zhang, Narayan Mandayam, Wenjia Yuan, Kristin Dana 

Enabling Vehicular Networking in the MobilityFirst Future Internet Architecture 
WoWMoM 2013 - 14th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks 
Akash Baid, Shreyasee Mukherjee, Tam Vu, Sandeep Mudigonday, Kiran Nagaraja, Junichiro Fukuyamaz, Dipankar Raychaudhuri 

Personal Touch-Identification Tokens 
Pervasice Computing 2013 IEEE Pervasive Computing Magazine, Apirl 2013 
Tam Vu, Marco Gruteser

Capacitive Touch Communication: A Technique to Input Data Through Devices' Touchscreen 
TMC 2013 IEEE Transactions on Mobile Computing, to appear, 2013. 
Tam Vu, Akash Baid,Simon Gao, Marco Gruteser, Richard Howard, Janne Lindqvist, Predrag Spasojevic, Jeffrey Walling 

Distinguishing Users with Capacitive Touch Communication [PDF] [Slides] - Best Paper Award, 2012 
MobiCom 2012 - The 18th ACM Annual Int' Conf' on Mobile Computing and Networking
Tam Vu, Akash Baid,Simon Gao, Marco Gruteser, Richard Howard, Janne Lindqvist, Predrag Spasojevic, Jeffrey Walling 
Press Release: MIT Technology ReviewPhys.orgDemo Video Interdigital Innovation Challenge Finalist

Demo: User Identification and Authentication with Capacitive Touch Communication [PDF] 
MobiSys 2012 - Proceedings of Mobisys 2012
Tam Vu, Ashwin Ashok, Akash Baid, Marco Gruteser, Richard Howard, Janne Lindqvist, Predrag Spasojevic, Jeffrey Walling
[Demo Video]     [Long Demo Video]

DMap: A Shared Hosting Scheme for Dynamic Identifier to Locator Mappings in the Global Internet [PDF][Slides]
ICDCS 2012 - The 32nd Int' Conf' on Distributed Computing Systems 
Tam Vu, Akash Baid, Yanyong Zhang, Thu Nguyen, Junichiro Fukuyama, Richard Martin and Dipankar Raychaudhuri
[Internet-scale (26,000+ ASes) Simulation source code]

Phantom: Physical Layer Cooperation for Location Privacy Protection [PDF] [Slides]
INFOCOM 2012 The 31st Annual IEEE Int' Conf' Computer Communications - Mini Conf' 
Sangho Oh, Tam Vu, Marco Gruteser, Suman Banerjeey

Sensing Driver Phone Use with Acoustic Ranging Through Car Speakers [PDF] 
TMC 2012 IEEE Transactions on Mobile Computing, 2012. 
Jie Yang, Simon Sidhom, Gayathri Chandrasekaran, Tam Vu, Hongbo Liu, Nic Cec, Yingying Chen, Marco Gruteser, Rich Martin 

Comparing Alternative Approaches for Networking of Named Objects in the Future Internet [PDF] 
INFOCOM 2012 The 31st Annual IEEE Int' Conf' Computer Communications - NOMEN workshop 
Akash Baid, Tam Vu, Dipankar Raychaudhuri

Detecting Driver Phone Use Leveraging Car Speakers [PDF] - Best Paper Award, 2011 
MobiCom 2011 - The 17th ACM Annual Int' Conf' on Mobile Computing and Networking 
Jie Yang, Simon Sidhom, Gayathri Chandrasekaran, Tam Vu, Hongbo Liu, Nic Cec, Yingying Chen, Marco Gruteser, Rich Martin 
Press Release: MIT Technology ReviewThe Wall Street JournalCNET NewsYahoo NewsNational Public Radio 1] [NPR 2]

Tracking Vehicular Speed Variations by Warping Mobile Phone Signal Strengths [PDF] [Slides] 
PerCom 2011 9th Annual IEEE Int' Conf' on Pervasive Computing and Communications 
Gayathri Chandrasekaran, Tam Vu, Alexander Varshavsky, Marco Gruteser, Rich Martin, Jie Yang, Yingying Chen 

Vehicular Speed Estimation using Received Signal Strength from Mobile Phones [PDF] [Slides]
UbiComp 2010 ACM International Conference on Ubiquitous Computing 
Gayathri Chandrasekaran, Tam Vu, Alexander Varshavsky, Marco Gruteser, Rich Martin, Jie Yang, Yingying Chen 

Ask, Don't Search: A Social Help Engine for Online Social Network Mobile Users [PDF] [Slides]
Sarnoff 2012 The 35th IEEE Sarnoff Symposium 
Tam Vu, Akash Baid ​



Capacitive Touch Communication - A Technique to Input Data Through Device's Touchscreens

As we are surrounded by an ever-larger variety of post-PC devices, the traditional methods for identifying and authenticating users have become cumbersome and time-consuming. This work presents a capacitive communication method through which a device can recognize who is interacting with it. It exploits the capacitive touchscreens, which are now used e.g. in laptops, phones, and tablets, as a signal receiver.

Press Release: MIT Technology Review,, [Demo Video], [Long Demo Video]



Acoustic Localization of Mobile phones in Car for Driver Safety Applications

This project aims at improving the driver safety by appropriately allowing or denying calls to the driver's mobile phone. The mobile phones equipped with microphones, calibrates its location within the car to determine if it is held by the driver or the passenger and accordingly enforces call policies. The technique that we propose makes use of human in-audible acoustic signals from the car's speakers to calibrate the location of the mobile phone.

Press Release: MIT Technology Review, The Wall Street Journal, CNET News, Yahoo News,



MobilityFirst - A mobile-centric architecture for next generation Internet

The project aims at the design and validation of comprehensive new architectures for the next-generation Internet. This is a three-year project (2010-13) with scope including network design, performance evaluation, large-scale prototyping and end-user application trials.

DMap - A Shared Hosting Scheme for Dynamic Identifier to Locator Mappings in the Global InternetM
DMap is the foundation for a fast global name resolution service necessary to enable emerging Internet services such as seamless mobility, content delivery and cloud computing. Our approach distributes identifier to locator mappings amongst Autonomous Systems (ASs) by directly applying K>1 consistent hash functions on the identifier to produce network addresses of the AS gateway routers at which the mapping will be stored. This direct mapping technique leverages the reachability information of the underly- ing routing mechanism which is already available at the network layer, and achieves low lookup latencies through a single overlay hop without additional maintenance overheads.

EIR - Edge-aware Interdomain Routing Protocol
Initially designed for communication between fixed hosts, the Internet does not handle well various forms of the dynamic introduced by today’s mobile platforms and applications. This dynamic, which ranges from explicit end-host mobility, multi-network operations, multi-path, and multi-homing to the flexible network boundary introduced by virtual networks, emerges at the edge networks posing a new set of desirable network functions. This project proposes a new interdomain routing protocol that takes edge-network dynamism into account. The key techniques in the design of EIR include: abstracting network entities, telescopic routing event dissemination, and late name to address binding.

Press Release: [MIT Tech Review Article covering FIA projects] [Read more...]



Fine-grain angular and distance ranging for indoor environment

Accurately estimating relative angles and ranges information between nearby devices is a hard problem, yet of importance to many context-aware applications such as augmented reality, autonomous automotive systems, smart manufacturing systems, etc. Existing indoor localization techniques could not meet the applications' requirements given the resource constraints. We have started exploring a technique that integrates wireless wearable devices with hardware adjuncts to provide spatial context information at centimeter-level accuracy from objects and people for indoor environment.



Location Privacy for All - A Network Architecture for Location Privacy

Traditionally, network designers have been forced to choose from either strong privacy with low performance and scalability architecture to the one with high performance and scalability yet no privacy at all. However, with the rapid growth in number of mobile devices and their traffic, the location privacy problem becomes more and more importance. Thus ignoring the issues of location privacy is no longer a reasonable option. In this work, we explore the space between traditional strong and optimistic privacy models and their tradeoffs in terms of performance and scalability. As a result, we propose a highly scalable network architecture with a set of protocols that guarantees measurable and customizable degrees of location privacy with high performance communication.



Physical Layer Cooperation for Location Privacy Protection

Localization techniques that allow inferring the location of wireless devices directly from received signals have exposed mobile users to new threats. Adversaries can easily collect required information (such as signal strength) from target users, however, techniques securing location information at the physical layer of the wireless communication systems have not received much attention. In this project we propose Phantom, a novel approach to allow mobile devices thwart unauthorized adversary’s location tracking by creating forged locations. In particular, Phantom leverages cooperation among multiple mobile devices in close vicinity and utilizes synchronized transmissions among those nodes to obfuscate localization efforts of adversary systems. Through an implementation on software-defined radios (GNU Radios) and extensive simulation with real location traces, we see that Phantom can improve location privacy.



Vehicular Speed Estimation Using Received Signal Strength from Mobile Phones

This project focuses on estimating vehicular speeds with high accuracy at the base station using the mobile phones in vehicles without the explicit participation from the drivers. The work is founded on the principles that RSS from Mobile phones on the GSM network are stable over time and variable over space. We apply classic dynamic programming techniques to estimate vehicular speeds with very high accuracy This technique can be more robust to small scale fading and can produce more accurate speed estimation compared to the traditional technique of localizing phones over time since we are now looking at a continuous time series instead of discrete signal strength readings.