1. 1 Cooperation vs. Contention the wireless sandbox Mihaela van der Schaar (UCLA) application layer/games Srikanth Krishnamurthy (UCR) integration of cooperation with higher layers Syed Jafar (UCI) cooperate vs. contend – do no harm Anna Scaglione (Cornell) randomized cooperation Urbashi Mitra (USC) coherent cooperation

2. 2 Cooperative Californians Mihaela van der Schaar (UCLA) applications/non-cooperation  cooperation Srikanth Krishnamurthy (UCR) integration of cooperation with higher layers Syed Jafar (UCI) cooperate vs. contend – do no harm Anna Scaglione (UCD) randomized cooperation Urbashi Mitra (USC) coherent cooperation

3. 3 Multiple Antennae TX RX TX RX multiple transmit/receive elements are co-located gains: performance/rate

4. 4 Cooperation: a vision? ? = multihop cooperative multihop

5. 5 How to signal? How to design signals sent by cooperating nodes? Distributed space- time modulation for arbitrary number of hops/number of nodes at each stage Some sometime assumptions –synchronization –channel state at RX (TX?) diversity slope ~ 2 diversity slope ~ 1.4

6. 6 Who should cooperate? resource allocation problems –size of cooperating set? –members of cooperating set? decision process and percolation of decisions cooperative estimation with finite network power square = source circles = sensors

7. 7 How do we scale?

8. 8 Questions Cooperation in NETWORKS –versus single source/single destination –medium access/multiple access –bridging PHY and higher layers for cooperation What is a link? What is a collision? How to fully exploit the physical layer? –new mathematical tools? –new mathematical abstractions! –for wireless PHY – our models have served us well!

9. 9 More Questions Overhead/cost –abstraction for overhead (feedback rate/training length) sparse representations –random versus deterministic (scheduled/structured) coherent versus random/robustness issues –how modeled? (ray tracing + random) Cognitive networks –prioritized cooperation –adaptive networks/adaptive signal processing network-centric signal processing –trading off PHY for higher layers