Publications by Lorenzo Keller

MicroCast: Cooperative Video Streaming Using Cellular and Local Connections

We consider a group of mobile users, within proximity of each other, who are interested in watching the same online video. The common practice today is that each user downloads the video independently on her mobile device using her own cellular connection, ...

Ieee-Inst Electrical Electronics Engineers Inc2016

System and method for cooperative data streaming

Lorenzo Keller, Christina Fragouli

A system and method for cooperative data streaming are disclosed. According to one embodiment, a system for cooperative data streaming comprises a group of devices comprising at least two devices, which are interested in obtaining the same content from the ...

2015

System and method for local multiplayer gaming

Lorenzo Keller, Christina Fragouli

A system and method for local multiplayer gaming are disclosed. According to one embodiment, a system comprises a plurality of mobile client devices including a mobile client device designated as a server device. Each mobile client device comprises a displ ...

2014

System and method for cooperative data streaming

Lorenzo Keller, Christina Fragouli

A system and method for cooperative data streaming are disclosed. According to one embodiment, a system for cooperative data streaming comprises a group of devices comprising at least two devices, which are interested in obtaining the same content from the ...

2013

Real-time delay with network coding and feedback

Lorenzo Keller, Christina Fragouli

2013

Function computation via subspace coding

Lorenzo Keller, Christina Fragouli, Nikhil Karamchandani

This paper considers function computation in a network where intermediate nodes perform randomized network coding, through appropriate choice of the subspace codebooks at the source nodes. Unlike traditional network coding for comput- ing functions, that r ...

2013

SenseCode: Network Coding for Reliable Sensor Networks

Lorenzo Keller, Christina Fragouli, Aikaterini Argyraki, Emre Atsan

Designing a communication protocol for sensor networks often involves obtaining the right trade-off between energy efficiency and end-to-end packet error rate. In this article, we show that network coding provides a means to elegantly balance these two goa ...

Assoc Computing Machinery2013

Low cost security for sensor networks

Lorenzo Keller, Christina Fragouli, Emre Atsan, Iris Safaka

We design and evaluate a lightweight encryption protocol suitable for sensor networks, that enables weak security in the presence of passive eavesdroppers. At every communication round, our protocol creates a key between each sensor node and the sink, by a ...

Institute of Electrical and Electronics Engineers Inc.2013

MicroCast: Cooperative Video Streaming on Smartphones

Lorenzo Keller, Christina Fragouli

Video streaming is one of the increasingly popular, as well as de- manding, applications on smartphones today. In this paper, we con- sider a group of smartphone users, within proximity of each other, who are interested in watching the same video from the ...

2012

MicroPlay: A Networking Framework for Local Multiplayer Games

Lorenzo Keller, Christina Fragouli

Smartphones are an ideal platform for local multiplayer games, thanks to their computational and networking ca- pabilities as well as their popularity and portability. How- ever, existing game engines do not exploit the locality of players to improve game ...

2012

Building Wireless Network Coding Protocols

Lorenzo Keller

This work studies how to build wireless network protocols that achieve better reliability, lower delay and higher throughput than existing alternatives by using network coding and by exploiting the broadcast nature of the wireless channel. In the first par ...

EPFL2012

A network coding approach to the shipper detection problem

Lorenzo Keller, Christina Fragouli, Abdulkadir Karaagaç

This paper experimentally studies the reliability and delay of flooding based multicast protocols for a sniper detection application. In particular using an emulator it studies under which conditions protocols based on network coding deliver performance im ...

2011

Function computation over linear channels

Lorenzo Keller, Christina Fragouli, Nikhil Karamchandani

We consider multiple non-colocated sources commu- nicating over a network to a common sink. We assume that the network operation is fixed, and its end result is to convey a fixed linear deterministic transformation of the source data to the sink. This line ...

2010

Function computation via subspace coding

Lorenzo Keller, Christina Fragouli, Nikhil Karamchandani

This paper considers function computation in a network where intermediate nodes perform randomized network coding, through appropriate choice of the subspace codebooks at the source nodes. Unlike traditional network coding for computing functions, that req ...

2010

Joint Identity-Message Coding for Sensor Networks

Lorenzo Keller, Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki

In a significant class of sensor-network applications, the identities of the reporting sensors constitute the bulk of the communicated data, whereas the message itself can be as small as a single bit—for instance, in many cases, sensors are used to detect ...

Institute of Electrical and Electronics Engineers2010

SenseCode: Network Coding for Reliable Sensor Networks

Lorenzo Keller, Christina Fragouli, Aikaterini Argyraki, Emre Atsan

Designing a communication protocol for sensor networks often involves obtaining the "right" trade-off between energy efficiency and reliability. In this paper, we show that network coding provides a means to elegantly balance these two goals. We present th ...

2009

Compressed network coding vectors

Lorenzo Keller, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki

In networks that employ network coding, two main approaches have been proposed in the literature to allow the receivers to recover the source information: (i) use of coding vectors, that keep track of the linear combinations the received packets contain, a ...

2009

Delay with network coding and feedback

Lorenzo Keller, Christina Fragouli

We consider the problem of minimizing delay when broadcasting over erasure channels with feedback. A sender wishes to communicate the same set of μ messages to several receivers over separate erasure channels. The sender can broad- cast a single message or ...

2009

Identity Aware Sensor Networks

Lorenzo Keller, Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki

In a significant class of sensor-network applications, the identities of the reporting sensors constitute the bulk of the communicated data, whereas the message itself can be as small as a single bit---for instance, in many cases, sensors are used to detec ...

2009

ConfErr: A Tool for Assessing Resilience to Human Configuration Errors

Lorenzo Keller, George Candea

We present ConfErr, a tool for testing and quantifying the resilience of software systems to human-induced configuration errors. ConfErr uses human error models rooted in psychology and linguistics to generate realistic configuration mistakes; it then inje ...

2008