IEEE International Workshop on
Wireless Network Coding

Rome, Italy June 22, 2009

Technical Program

8:45 - 9:00 Opening Remarks

9:00 - 10:00 Keynote by Prof. Dina Katabi (MIT)

Title: Advances in Cross-Layer Wireless Design

Abstract:  This talk advocates a cross-layer wireless design for dealing with interference. It shows that such an approach changes the way interference is perceived. Instead of viewing interference as an inherently counterproductive phenomenon, we show how to successfully reconstruct the transmitted information even in the presence of collisions, thereby rendering the interference harmless. Moreover, we show how to exploit interference constructively to increase the throughput.

Specifically, I will first present ZigZag decoding, which allows a receiver to decode collisions without any assumptions of sender synchronization, large differences in power, or special codes. In fact, our approach exploits the natural asynchrony between colliding transmitters. This asynchrony results in stretches of interference-free bits at the start of a collision, which we use to bootstrap our decoder. Our approach introduces no overhead when there are no collisions. But when senders collide the receiver successfully reconstructs the transmitted information, eliminating unnecessary retransmissions to attain the same throughput as if the packets did not collide at all.

Next, I will present Analog network coding (ANC) which encourages strategically picked senders to interfere. Instead of forwarding packets, routers forward the interfered signal. The destination leverages network-level information to cancel the interference and recover the transmitted signal. Both analytic and experimental results from a testbed show the benefits of this approach.

Bio:  Dina Katabi is an Associate Professor in the Electrical Engineering and Computer Science Department at MIT. She has joined the MIT faculty in March 2003, after completed her PhD at MIT. Dina's work focuses on wireless networks, network security, routing, and distributed resource management. She has award winning papers in ACM SIGCOMM and Usenix NSDI. She has been awarded the IEEE William R. Bennett prize in 2009, a Sloan Fellowship in 2006, the NBX Career Development chair in 2006, and an NSF CAREER award in 2005. Her doctoral dissertation won an ACM Honorable Mention award and a Sprowls award for academic excellence.

10:00 - 10:30 Break

10:30 - 11:45 Session 1

Efficient Network Coding Algorithms For Dynamic Networks
Mohammad Asad Chaudhry (Texas A&M University, US); Salim El Rouayheb (Texas A&M University, US); Alex Sprintson (Texas A&M University, US)

A Distributed Framework for Network Coding Based on a Novel State Space Approach
Giuseppe Campobello (University of Messina, IT); Alessandro Leonardi (University of Catania, IT); Sergio Palazzo (University of Catania, IT)

On Distributed Rate Allocation for Network-Coded Systems
Amin Jafarian (The University of Texas, Austin, US); Sang Hyun Lee (University of Texas at Austin, US); Sriram Vishwanath (University of Texas at Austin, US); Christina Fragouli (EPFL, CH)

11:45 - 1:00 Lunch

1:00 - 2:00 Keynote by Prof. Suhas Diggavi (EPFL)

Title: Wireless Network Information Flow

Abstract: Suppose we want to send information from a source to a destination over a wireless network of an arbitrary configuration of relay nodes. In direct contrast to wired networks, wireless transmissions are broadcast, and they interfere with each other at a receiver. The fundamental challenge is to model and utilize these complex interactions for co-operative information flow.  

Characterizing how much information can flow over networks over such wireless relay networks is a long-standing problem. In a case of a single unicast flow over a wireline network, the solution is given by the classical max-flow min-cut theorem due to Ford-Fulkerson in 1956. This was extended to the multicast case by Ahlswede et al in 2000, which shows the surprising result that network coding is needed to achieve the min-cut bound. In this talk, we examine a theory for wireless networks which utilizes the broadcast and superposition properties of the wireless medium.  

We have developed linear deterministic models that (approximately) capture these interactions and show that for such models, one can obtain an information-theoretic max-flow min-cut result, in analogy to the classic wireline Ford-Fulkerson result. We have extended these ideas to networks with general deterministic (interaction) functions. Using insights from the analysis of deterministic networks, we develop an approximate characterization for noisy Gaussian relay networks showing that the achievable rate is within a constant number of bits from the information-theoretic cut-set upper bound on the capacity of these networks. This constant depends on the topology of the network, but not the values of the channel gains.  

We conclude with a variety of new applications where this methodology sheds insight including wireless multiple unicast, wireless network secrecy etc.  These results show that characterizations, within a constant number of bits approximation, may be a promising direction to get theoretical insights into wireless network information flow.

Bio:  Suhas N. Diggavi received the B. Tech. degree in electrical engineering from the Indian Institute of Technology, Delhi, India, and the Ph.D. degree in electrical engineering from Stanford University, Stanford, CA, in December 1998.

After completing his Ph.D., he joined the Information Sciences Center, AT&T Shannon Laboratories, Florham Park, NJ. where he was a Principal Member Technical Staff. He is currently in the faculty of the School of Computer and Communication Sciences, EPFL, where he heads the Laboratory for Information and Communication Systems (LICOS). His research interests include wireless network communications, information theory, source coding and signal processing. He has over 100 publications in journals and conferences, as well as 8 issued patents on these topics; more information can be found at

He is a recipient of the 2006 IEEE Donald Fink prize paper award, 2005 IEEE Vehicular Technology Conference best paper award and the Okawa foundation research award. He has served as an associate editor for the IEEE Communication Letters, and on the technical program committee for several conferences including ISIT, ICC, ITW, Globecom.

2:00 - 3:15 Session 2

Improving Network Coded Cooperation by Soft Information
Tobias Volkhausen (University of Paderborn, DE); Dereje H. Woldegebreal (University of Paderborn, DE); Holger Karl (University of Paderborn, DE)

Active Physical-Layer Network Coding for Cooperative Two-Way Relay Channels
Haishi Ning (Imperial College London, UK); Cong Ling (Imperial College London, UK); Kin Leung (Imperial College, UK)

Joint Network and Channel Coding for Wireless Networks
Qiang Li (Nanyang Technological University, SG); See Ho Ting (Nanyang Technological University, SG); Chin Keong Ho (Institute for Infocomm Research, SG)

3:15 - 3:45 Break

3:45 - 5:00 Session 3

Non-Random Wireless Network Coding
Ketan Rajawat (University of Minnesota, US); Georgios B. Giannakis (University of Minnesota, US)

Joint Network Coding and Power Control for Wireless Linear Networks
Tuan Tran (Oregon State University, US); Dong Nguyen (Oregon State University, US); Thinh Nguyen (Oregon State University, US)

Factorization for Advanced Physical Layer Techniques in Network-Coded Wireless Communication Networks
Maximilian Riemensberger (Technische Universität München, DE); Andreas Dotzler (Technische Universität München, DE); Wolfgang Utschick (Technische Universität München, DE)