WPerformance: Palestra 2: "Block Switching: Towards a Robust Protocol Stack for Diverse Wireless Networks"
Arun Venkataramani (University of Massachussets Amherst, EUA)
Horário: 16:15 - 18:15
Local: Auditório 9

Short Bio:
 Arun Venkataramani has been an Assistant Professor in the Department of Computer Science at the University of Massachusetts Amherst since Spring 2005. He completed his PhD in Computer at the University of Texas at Austin in 2004 and was a Visiting Faculty at University of Washington in Fall 2004. He received his bachelor's degree in Computer Science and Engineering at IIT Bombay in 1999. His research interests are in networking and distributed systems and his current research focuses on wireless and mobile networks, peer-to-peer systems, network architecture, virtualization, and security. His dissertation work developed TCP Nice, a protocol for low priority background transport without network support. He is a recipient of an NSF CAREER award and his work has received several best paper awards including USENIX NSDI 2007 and 2008. He has served on the program committees of ACM Sigcomm, USENIX NSDI, IEEE Infocom and several other conferences in networking and systems.

The Internet's TCP/IP stack was not designed with the vagaries of the wireless channel and mobility in mind and is showing signs of age today. For example, TCP has well-known problems over wireless networks as it conflates congestion and loss, performs poorly over lossy or fluctuating links, and is fragile in the presence of route changes and disconnections induced by mobility.
This talk is motivated by the following question: how can we design a protocol stack that ensures robust performance across diverse wireless networks such as access point networks, multi-hop mesh networks, mobile ad hoc networks, and disruption-tolerant networks? To address this question, I will present two ideas and proof-of-concept systems. The first is to use "reliable per-hop block transfer" as a building block for wireless transport. I will show the benefits of the block transfer approach through the design and implementation of Hop, a wireless transport protocol that achieves dramatically better throughput, fairness, delay, and robustness to partitions. The second is the use of "block replication" as opposed to simple packet forwarding for routing under uncertainty through the design and implementation of RAPID, a disruption-tolerant network routing protocol. Finally, I will outline research challenges and opportunities enabled by block transfer in order to realize the vision of a robust protocol stack for diverse wireless networks.