Medium Access in new Contexts: Reinventing the Wheel?

1. Medium Access in new Contexts: Reinventing the Wheel? USC Invited Workshop on Theory & Practice in Wireless Networks May 21, 2008

2. “I was originally supposed to become an engineer, but the thought of having to expend my creative energy on things that make practical everyday life even more refined, with a bleak capital gain as the reward, was unbearable to me.” Albert Einstein to Heinrich Zangger, Aug. 11, 1918 “Scientists discover the world that exists; engineers create the world that never was.” Theodore von Karman

3. Your Panelists • John Heidemann, USC/ISI • Koushik Kar, Rensselaer Polytechnic Institute • Mani Srivastava, UCLA • Mingyan Liu, University of Michigan, Ann Arbor • Kevin Almeroth, UC-Santa Barbara (moderator)

4. MAC Protocolsas the newBlood-Brain Barrier Kevin C. Almeroth UC-Santa Barbara May 21, 2008

5. Outline/Points/Conclusions • There are some very interesting network architecture possibilities • Greatly expanded ranges of delay/loss/jitter and connectivity/disconnectivity • Still a clear delineation between PHY/MAC and NET/TRN/APP • Even in the face of cross-layer design • Warning: we might be creating a “Networking Winter” • Similar to HCI and OS

7. The Spectrum of Connectivity Possibilities Autonomous Operation Continuous Connectivity

8. The Spectrum of Connectivity Possibilities Autonomous Operation Continuous Connectivity Intermittent Connectivity Intermittent Disconnectivity Infrequent Connectivity

9. The Spectrum of Connectivity Possibilities Topology Variations Autonomous Operation Continuous Connectivity Intermittent Connectivity Intermittent Disconnectivity Infrequent Connectivity End-to-End Availability

10. Transformational Communication (TSAT)

11. The Blood-Brain Barrier “A mechanism that controls the passage of substances from the blood into the cerobrospinal fluid and thus into the brain and spinal cord. The blood-brain barrier (BBB) lets essential metabolites, such as oxygen and glucose, pass from the blood to the brain and central nervous system (CNS) but blocks most molecules that are more massive.“ “The Internet Encyclopedia of Science”

12. The Blood-Brain Barrier “A mechanism that controls the passage of substances from the blood into the cerobrospinal fluid and thus into the brain and spinal cord. The blood-brain barrier (BBB) lets essential metabolites, such as oxygen and glucose, pass from the blood to the brain and central nervous system (CNS) but blocks most molecules that are more massive.“ “The Internet Encyclopedia of Science”

13. The Blood-Brain Barrier “A key aspect of the blood-brain barrier are the thin, flat cells known as endothelial cells which form the walls of capillaries. In most parts of the body, the endothelial cells in the capillaries overlap at what are called junctions. These junctions are leaky enough to let a lot of different materials move through the wall of the blood vessel into the tissue and back again. These materials include normally beneficial stuff such as hormones and nutrient molecules as well as potentially harmful agents like toxins, viruses, and bacteria.” “The Internet Encyclopedia of Science”

14. Outline/Points/Conclusions • There are some very interesting network architecture possibilities • Greatly expanded ranges of delay/loss/jitter and connectivity/disconnectivity • Still a clear delineation between PHY/MAC and NET/TRN/APP • Even in the face of cross-layer design • There are impacts, but is there really a need for cross-layer design? • Warning: we might be creating a “Networking Winter” • Similar to HCI and OS • If all we do is solve the same problems in new contexts or with new (but modestly artificial) resource constraints, we aren’t doing anything new • The biggest disconnect is not between theoreticians and practitioners but between researchers and corporations