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Open Problems: What should you work on for the next 4 years?. Fred Baker, Fellow CISCO Bob Briscoe, British Telecom George Varghese, UCSD/ entrepreneur John Wroclawski, ISI Networking Director Facilitator: Michalis Faloutsos, UCR. ICNP 2006 - Panel. We wish a quick recovery….
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Open Problems: What should you work on for the next 4 years? Fred Baker, Fellow CISCO Bob Briscoe, British Telecom George Varghese, UCSD/entrepreneur John Wroclawski, ISI Networking Director Facilitator: Michalis Faloutsos, UCR ICNP 2006 - Panel M. Faloutsos UC Riverside
We wish a quick recovery… • to Darleen Fischer (NSF) • who would have been here • but cannot due to non-threatening health reasons M. Faloutsos UC Riverside
The Goal is to Provoke • Provoking is an essential human function • I provoke, therefore I think, therefore I exist • A good panel should result in a fist-fight • Conclusion: We need controversy M. Faloutsos UC Riverside
My First Choices for the Panel M. Faloutsos UC Riverside
Final Panel • Fred Baker, Fellow CISCO • Bob Briscoe, British Telecom • George Varghese, UCSD/entrepreneur • John Wroclawski, ISI Networking Director Alphabetical Order M. Faloutsos UC Riverside
The Focus of the Panel • The most exciting idea you have read recently • The right area for a new researcher to tackle • A problem the community should solve • You would give money for the research • You would invest in the start up • You would give $20 out of your pocket • A technology or user trend that will make a splash in 2-5 years M. Faloutsos UC Riverside
Playing the Devil’s Advocate M. Faloutsos UC Riverside
My Challenge to the Panel: • Everything important has already been discovered • We are not reinventing, just renaming • Let the industry do the research it needs • Academia is consumed by paper-o-lagnia • Greek: Lagnia = desire, lust for • We should all change professions M. Faloutsos UC Riverside
Something New and Cool • I ‘d give $20 to see it fully implemented M. Faloutsos UC Riverside
Cooperative Diversity in ad hoc networks • “United we transmit” B A M. Faloutsos UC Riverside
Synchronous Tx = Contention • So far, overlapping transmissions = BAD • Hidden and exposed terminals • Self-contention: packets of the same flow • Current Focus: reduce contention A D B B A C D C M. Faloutsos UC Riverside
Cooperative Diversity: A Paradigm Shift • Cooperation instead of Contention • A phy breakthrough • Multiple transmissions can be combined at the receiver • Not only they don’t cancel out • They improve the success of transmission! B A Node A cooperates with neighbors to send the same packet to B M. Faloutsos UC Riverside
Cooperative Diversity: Essentials • Solicit/select the cooperation of neighbors • Provide the cooperating neighbors with a copy of the data packet. • Ensure that the receiver has CSI for the links to every cooperating node. B A Node A cooperates with neighbors to send the same packet to B M. Faloutsos UC Riverside
Cooperative Diversity is Counter Intuitive • Transmission range is longer than interference range! • The transmissions range is increased by a factor of 5.4 • The interference range by a factor of 1.7 • For diversity gain 15 dB, path loss 3, BER 10^-3 Coop Interference B A C M. Faloutsos UC Riverside
S D S I D 1.What Cooperation Buys Us • We can “shorten” our paths • Path using cooperative diversity M. Faloutsos UC Riverside
2. What Cooperation Buys Us • Can bridge gaps in sparse networks • Connect disconnected networks • Enable weak-device networks • The sensor network reach-back problem • Many sensors cooperate to reach the sink! M. Faloutsos UC Riverside
Can this translate to network performance? • Phy layer has been well studied • Recently efforts show big gains in higher layer performance • Implementation is pending… Cooperative Performance is red Delay Thruput M. Faloutsos UC Riverside
If you want to see more: • J.N.Laneman, “Cooperative diversity in wireless networks: Algorithms and architectures”, Ph.D. Thesis, Massachusetts Institute of Technology, August 2002. • G. Jakllari et al. "A Cross-Layer Framework for Exploiting Virtual MISO Links in Mobile Ad hoc Networks" IEEE Transactions on Mobile Computing to appear. • G. Jakllari et al. "On Broadcasting with Cooperative Diversity in Multi-hop Wireless Networks ” IEEE JSAC to appear. • A. Khandani, et al. “Cooperative routing in wireless networks.”, Allerton Conference on Communications, Control and Computing, October 2003. • X, Li, Space-Time Coded Multi-Transmission Among Distributed Transmitters without Perfect Synchronization, IEEE Signal Processing Letters, 11(12), December 2004. • A. Sendonaris et al. “User Cooperation Diversity--Part II: Implementation Aspects and Performance Analysis”, IEEE Transactions on Communications, 51(11), November 2003. M. Faloutsos UC Riverside
Thank You! M. Faloutsos UC Riverside