Overview of Research Activities
NSRC Industry Day, October 17, 2006
Aylin Yener
[email protected]
http://labs.ee.psu.edu/labs/wcan
WCAN@PSU
• Wireless Communications and Networking Laboratory :
@ Penn State since January 2002
• Members: 1 Visiting Prof, 9 students (8 PhD, 1 MS)
• Currently supported by
– National Science Foundation
CAREER-CCF (2003);
CCF (2005);
CNS-NeTS (2006)
– DARPA (CBMANET, ITMANET)
– Raytheon (Networking and Security Research Center)
• Previous support Ack.: NSF-CNS(2005), TechCollaborative,
Pennsylvania Infrastructure for Technology Alliance (PITA), NSRC:
Telcordia, USMC
WCAN@PSU
• Mission: Perform fundamental research
on wireless communication network
design
• Main research theme is optimum design
of Nth generation wireless systems
High capacity, reliable, secure wireless communication
Research Areas
• Research concentrated on physical layer and its
interaction with upper layers up to network layer
for multiuser and multiantenna (MIMO) wireless
networks.
• Physical layer (PHY)
– Current design focus:
Jointly optimize all available resources for maximum
multiuser system capacity;
Security versus capacity trade-off in the multiuser
setting
• Cross-layer approach (Joint PHY + MAC + Network
L)
– Current design focus:
Relay networks of agile radios
Resource allocation for wireless network coding
Research Vision: Wireless World
Cellular
Network
Relay
Network
RFID/Sensor
Network
•Future wireless networks will consist of cooperating nodes relaying traffic
over several networks: RFID, sensor networks, WLANS, cellular network will
all have to co-exist and cooperate!
•Transceivers will employ multiple antennas, be equipped with smart software
radios that can change format (AGILE) in response to the current channel
conditions (COGNITIVE).
Hybrid Wireless Networks
(NSF-CNS 2006)
• A new network design paradigm where
information is relayed through multiple
wireless nodes that can operate with different
standards.
 Fusion of multiple communication standards
 Synergistic combining to leverage advantages of
different wireless networks (e.g., Wi-Fi plus HDR )
 Throughput gain
 Network reliability
 Security
 Hybrid Wireless Relay Network is the future
wireless network
Hybrid Wireless Networks
• For each information source, we can optimally allocate
the transmitted power and bandwidth, i.e., the limited
wireless resources, between all available “standards”,
yielding a more efficient overall architecture.
• Our recent results also point to the need for accurate
spectrum sensing of cognitive radios and cooperation
between them to get the “most” out of this architecture.
• Complete system architecture, many challenges
including trust issues and persuading the cognitive
nodes to cooperate.
• Results, directions stem from the nature of the radio
channel.
Multiuser MIMO Systems
(NSF-CAREER 2003)
• Multiuser system with multiple antennas 
”Multiuser MIMO System”
• Each user has multiple transmit antennas
• Each user can only utilize its resources
(antennas)
• Users interfere with each other
• Performance optimization: precoder-decoder
design for all users jointly.
– narrowband MIMO channels
– CDMA-MIMO
– designs with limited feedback, e.g. antenna selection.
• Ad hoc networks where nodes employ or form
virtual multiple antenna systems
Secure Multiuser Systems
(NSF-CCF 2005)
• Wireless security concerns currently handled by upper
layers of the protocol stack  top-to-bottom approach.
• Can we design a secure wireless network from PHY up?
• Tool: Network Information Theory, Aim: Ultimate
performance limits in the presence of intruders
• Challenging design problems arise when we consider nonpoint-to-point communication systems with security
threats, i.e., eavesdroppers and (intelligent) jammers
– resource allocation for secure transmission AND maximum
capacity
– multiaccess/broadcast/relay channel, MIMO, CDMA
Cross Layer Design for
Network Coding
(CBMANET 2006)
• CONCERTO is a multi-institution project (BAE
Systems, CalTech, Cornell, MIT, Penn State
(PI:T. La Porta), Stow Research, UIUC,
UMass)
• Network coding is a new paradigm that
allows packets to be combined in-network,
as opposed to traditional forwarding
(routing).
• The aim is to demonstrate that network
coding along with careful cross layer design
provides a significant performance
improvement.
A New Information Theory for
Mobile Ad Hoc Networks
(ITMANET 2006)
• In 2006, DARPA has revealed a call for proposals that asked for
a new theory to understand the true performance limits of
mobile ad hoc wireless networks. Two competitions: “Young
investigator” and “Senior”, one winner each.
• The winning young investigator team:
 D. Katabi (MIT),
 R. Berry, D. Guo (Northwestern),
 M. Haenggi (Notre Dame),
 A. Yener (Penn State),
 S. Jafar (UC Irvine),
 N. Jindal (U of Minnesota),
 J. Andrews, R. Heath, S. Shakkottai, P. Stone (UT Austin),
 M. Neely (USC).
• $13M question to be answered in 4.5 years: What is the ultimate
capacity of a MANET?
More info
[email protected]
http://labs.ee.psu.edu/labs/wcan