180 Park Ave - Building 103
Florham Park, NJ
http://www.kiskeya.net/ramon/
Ramón Cáceres is an experimental researcher in computer systems and networks. His research interests include mobile and pervasive computing, wireless networking, virtualization, security, and privacy. He is an ACM Distinguished Scientist and holds a Ph.D. from the University of California at Berkeley. He was born and raised in Dominican Republic.
Towards Synchronization of Live Virtual Machines among Mobile Devices
Jeffrey Bickford, Ramon Caceres
Workshop on Mobile Computing Systems and Applications (ACM HotMobile 2013),
2013.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in 2012 , 2013-02-26.
{The mobile computing experience would improve if users could switch seamlessly from one device to another, with both data and computation state preserved across the switch without apparent delay. This paper proposes VMsync, a system for synchronizing the state of live virtual machines (VMs) among mobile devices. VMsync seeks to incrementally transfer changes in an active VM on one device to standby VMs in other devices, so as to maintain a consistent VM image and minimize switching latency. However, constraints of the mobile environment make these goals difficult to achieve and raise many research questions. We present our preliminary design for VMsync and a feasibility study aimed at determining how much data would need to be transferred under different workloads and synchronization policies. For example, through experiments with a Xen VM running Android and playing a YouTube video, we show that sending dirty memory pages transfers 3 times more data than sending only the bytes that actually changed in those pages. Overall, we conclude that VMsync is a feasible approach deserving of further research.}
Human Mobility Characterization from Cellular Network Data
Richard Becker, Ramon Caceres, Karrie Hanson, Sibren Isaacman, Ji Loh, Margaret Martonosi, James Rowland, Simon Urbanek, Alexander Varshavsky, Christopher Volinsky
Communications of the ACM,
2013.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Communications of the ACM , Volume 56, Issue 1, 2013-01-01.
{Characterizing human mobility patterns is critical to a deeper understanding of the effects of people’s travel on society and the environment. Location data from cellular telephone networks can shed light on human movements cheaply, frequently, and on a large scale. We have developed techniques for analyzing anonymized cellphone locations to explore various aspects of human mobility, in particular for hundreds of thousands of people in each of the Los Angeles, San Francisco, and New York metropolitan areas. Our results include measures of how far people travel every day, estimates of carbon footprints due to home-to-work commutes, maps of the residential areas that contribute workers to a city, and relative traffic volumes on commuting routes. We have validated the accuracy of our techniques through comparisons against ground truth provided by volunteers and against independent sources such as the US Census Bureau. Throughout our work, we have taken measures to preserve the privacy of cellphone users. This article presents an overview of our methodologies and findings.}
mClouds: Computing on Clouds of Mobile Devices
Emiliano Miluzzo, Ramon Caceres, Yih Chen
International Workshop on Mobile Cloud Computing and Services (MCS '12) with MobiSys 2012,
2012.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in 2012 , 2012-06-25.
{When we think of mobile cloud computing today, we typically refer to empowering mobile devices -- in particular smartphones and tablets -- with the capabilities of stationary resources residing in giant data centers. But what happens when these mobile devices become as powerful as our personal computers or more? This paper presents our vision of a future in which mobile devices become a core component of mobile cloud computing architectures. We envision a world where mobile devices will be capable of forming mobile clouds, or mClouds, to accomplish tasks locally without relying, when possible, on costly and, sometimes, inefficient backend communication. We discuss a possible mClouds architecture, its benefits and tradeoffs, and the user incentive scheme to support the mCloud design.}
Ubicomp Systems at 20: Progress, Opportunities, and Challenges
Ramon Caceres, Adrian Friday
IEEE Pervasive Computing,
2012.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in IEEE Pervasive Computing. , Volume 11, Issue 1, 2012-01-01
{Twenty years ago, Weiser set forth his compelling vision of ubiquitous computing (ubicomp), giving rise to a rich multifaceted area of research. This community spawned several major conferences, journals, and magazines, including IEEE Pervasive Computing ten years ago. At this milestone, we take stock of where ubicomp systems research has journeyed and postulate the major challenges going forward.}
Obtaining In-Context Measurements of Cellular Network Performance
Aaron Gember, Jeffrey Pang, Alexander Varshavsky, Ramon Caceres, Aditya Akella
ACM Internet Measurement Conference,
2012.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in 2012 , 2012-11-14.
{Network service providers, and other parties, require an accurate understanding of the performance cellular networks deliver to users. In particular, they often seek a measure of the network performance users experience solely when they are interacting with their device—a measure we call in-context. Acquiring such measures is challenging due to the many factors, including time and physical context, that influence cellular network performance. This paper makes two contributions. First, we conduct a large scale measurement study, based on data collected from a large cellular provider and from hundreds of controlled experiments, to shed light on the issues underlying in-context measurements. Our novel observations show that measurements must be conducted on devices which (i) recently used the network as a result of user interaction with the device, (ii) remain in the same macro-environment (e.g., indoors and stationary), and in some cases the same micro-environment (e.g., in the user’s hand), during the period between normal usage and a subsequent measurement, and (iii) are currently sending/receiving little or no user-generated traffic. Second, we design and deploy a prototype active measurement service for Android phones based on these key insights. Our analysis of 1650 measurements gathered from 12 volunteer devices shows that the system is able to obtain average throughput measurements that accurately quantify the performance experienced during times of active device and network usage.}
Human Mobility Modeling at Metropolitan Scales
Sibren Isaacman, Richard Becker, Ramon Caceres, Margaret Martonosi, James Rowland, Alexander Varshavsky, Walter Willinger
10th ACM International Conference on Mobile Systems, Applications and Services (MobiSys 2012),
2012.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in [10th ACM International Conference on Mobile Systems, Applications and Services (MobiSys 2012)] , 2012-06-26.
{Models of human mobility have broad applicability in fields such as mobile computing, urban planning, and ecology. This paper proposes and evaluates WHERE, a novel approach to modeling how large populations move within different metropolitan areas. WHERE takes as input spatial and temporal probability distributions drawn from empirical data, such as Call Detail Records (CDRs) from a cellular telephone network, and produces synthetic CDRs for a synthetic population. We have validated WHERE against billions of anonymous location samples for hundreds of thousands of phones in the New York and Los Angeles metropolitan areas. We found that WHERE offers significantly higher fidelity than other modeling approaches. For example, daily range of travel statistics fall within one mile of their true values, an improvement of more than 14 times over a Weighted Random Waypoint model. Our modeling techniques and synthetic CDRs can be applied to a wide range of problems while avoiding many of the privacy concerns surround- ing real CDRs.}
Exploring the Use of Urban Greenspace through Cellular Network Activity
Ramon Caceres, James Rowland, Christopher Small, Simon Urbanek
2nd Workshop on Pervasive Urban Applications (PURBA),
2012.
[PDF]
[BIB]
Springer Copyright
The definitive version was published in 2012 , 2012-06-19
{Knowing when and where people use greenspace is key to our understanding of urban ecology. The number of cellular phones active in a geographic area can serve as a proxy for human density in that area. We are using anonymous records of cellular network activity to study the spatiotemporal patterns of human density in an urban area. This paper presents the vision and some early results of this effort. First, we describe our dataset of six months of activity in the New York metropolitan area. Second, we present a novel technique for estimating network coverage areas. Third, we describe our approach to analyzing changes in activity volumes within those areas. Finally, we present preliminary results regarding changes in human density around Central Park. From winter to summer, we find that density increases in greenspace areas and decreases in residential areas.}
Route Classification using Cellular Handoff Patterns
Christopher Volinsky, Alexander Varshavsky, Richard Becker, Ji Loh, Simon Urbanek, Ramon Caceres, Karrie Hanson
13th ACM International Conference on Ubiquitous Computing,
2011.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2011. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in 13th ACM International Conference on Ubiquitous Computing , 2011-09-01.
{Understanding utilization of city roads is important for urban planners. In this paper, we show how to use cellular hand- off patterns from cellular phone networks to identify which routes people take through a city. Specifically, this paper makes the following three contributions. First, we show that cellular handoff patterns on a given route are stable across a range of conditions and propose a way to measure stability within and between routes using a variant of Earth Mover�s Distance. Second, we present two accurate classification al- gorithms for matching cellular handoff patterns to routes: one requires test drives on the routes while the other uses signal strength data collected by high-resolution scanners. Finally, we present an application of our algorithms for mea- suring relative volumes of traffic on routes leading into and out of a specific city, and validate our methods using statis- tics published by a state transportation authority.}
Predicting Handoffs in 3G Networks
Ramon Caceres, Jeffrey Pang, Alexander Varshavsky, Umar Javed, Dongsu Han, Srinivasan Sesah
3rd ACM SOSP Workshop on Networking, Systems, and Applications on Mobile Handhelds (MobiHeld),
2011.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2011. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in 3rd ACM SOSP Workshop on Networking, Systems, and Applications on Mobile Handhelds (MobiHeld) , 2011-10-23.
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Clustering Anonymized Mobile Call Detail Records to Find Usage Groups
Christopher Volinsky, Richard Becker, Ramon Caceres, Karrie Hanson, Ji Loh, Simon Urbanek, Alexander Varshavsky
1st Workshop on Pervasive Urban Applications (PURBA),
2011.
[PDF]
[BIB]
Springer Copyright
The definitive version was published in PURBA-2011. , 2011-06-12
{Understanding the mix of different types of people in a city is an important input into urban planning. In this paper we identify distinct sectors of a population by their cellular phone usage. In a study of a small suburban city in New Jersey, we use unsupervised clustering to identify the usage patterns of heavy users . We uncover 7 unique usage patterns. We interpret two of the patterns as belonging to commuters and students, and verify these interpretations with deeper analysis of temporal and spatial patterns. }
A Tale of One City: Using Cellular Network Data for Urban Planning
Richard Becker, Ramon Caceres, Karrie Hanson, Ji Loh, Simon Urbanek, Alexander Varshavsky, Christopher Volinsky
IEEE Pervasive Computing ,
2010.
[PDF]
[BIB]
IEEE Copyright
The definitive version was published in IEEE Pervasive Computing , 2010-04-01, URL: https://ecopyright.ieee.org/ECTT/login.jsp Username: SCHPCSI-2011-01-0005 Password: 1295115660850
{The rapid growth of modern cities leaves urban planners faced with numerous challenges, such as high congestion and pollution levels. Effectively solving these challenges re- quires a deep understanding of existing city dynamics. In this paper, we describe methodology to study and monitor these dynamics by using Call Detail Records (CDRs), rou- tinely collected by wireless service providers as part of run- ning their networks. Our methodology scales to an entire population, has little additional cost, and can be continually updated. This provides an unprecedented opportunity to study and monitor cities in a way that current practices are not able to do.}
Method And Apparatus For Providing Mobile And Social Services Via Virtual Individual Servers,
Tue May 07 17:26:14 EDT 2013
A method, computer readable medium and apparatus for providing a virtual individual server service within a communications network are disclosed. For example, the method receives a request from a subscriber of the communications network to subscribe to the virtual individual server service, provides a virtual individual server to the subscriber in response to the request and executes at least one application via the virtual individual server using at least one piece of personal information associated with the subscriber.
System And Method For Providing Wireless Services Within A Wireless Local Area Network,
Tue Dec 27 16:02:22 EST 2011
The invention provides a system and method for providing a temporary wireless service connection to one or more users within a wireless local area network. In-building services and Internet related services are provided to the users over their respective temporary wireless service connections. Each user is charged for their specific usage amounts which may be based on the number of packets transferred, the number of bytes transferred, the number of distinct transactions and/or the time period each user's temporary wireless service connection was active.
System And Method For Providing Wireless Services Within A Wireless Local Area Network,
Tue Jan 11 16:01:47 EST 2011
The invention provides a system and method for providing a temporary wireless service connection to one or more users within a wireless local area network. In-building services and Internet related services are provided to the users over their respective temporary wireless service connections. Each user is charged for their specific usage amounts which may be based on the number of packets transferred, the number of bytes transferred, the number of distinct transactions and/or the time period each user's temporary wireless service connection was active.
System And Method For Providing Wireless Services Within A Wireless Local Area Network,
Tue Oct 13 15:38:48 EDT 2009
The invention provides a system and method for providing a temporary wireless service connection to one or more users within a wireless local area network. In-building services and Internet related services are provided to the users over their respective temporary wireless service connections. Each user is charged for their specific usage amounts which may be based on the number of packets transferred, the number of bytes transferred, the number of distinct transactions and/or the time period each user's temporary wireless service connection was active.
IEEE Fellow, 2013.
For contributions to mobile computing and communications.
