Stanford Networking Seminar

12:15PM, Thursday October 15, 2009
Gates 104


The makings of CTP Noe: A robust, reliable, and efficient routing protocol for wireless sensor networks.
 

Omprakash Gnawali
Stanford University


About the talk:
This talk describes the challenges in designing a sensor network routing protocol and presents CTP Noe, a widely-used collection routing protocol, to understand the key design features that make it robust, reliable, and efficient while remaining platform independent. Collection Tree Protocols (CTP) compute anycast routes to a single or a small number of designated sinks (destinations) in a wireless sensor network. Despite the critical importance of collection to almost every wireless sensor networks deployed to monitor the environment (buildings, rivers, forests, shipping containers, agriculture farms, etc.), prior to CTP, no collection layer was available that met the goals of robust, reliable, and efficient routing while remaining platform independent. CTP Noe advances the design of wireless sensor network protocol using three key ideas to meet those goals. First, it uses agile and accurate link estimator using information from the physical, link, and network layers. Second, it uses adaptive beacons to minimize control overhead without sacrificing agility to topology changes. Finally, it uses datapath validation of routing inconsistencies to quickly detect and repair loops. CTP Noe has been used on numerous deployments and tested on 12 different testbeds ranging in size from 20–310 nodes, comprising seven platforms, and six different link layers, on both interference-free and interference-prone channels. In all cases, CTP Noe delivers > 90% of packets, frequently achieving 99.9%. This talk describes how the three mechanisms (agile link estimation, adaptive beaconing, and datapath validation) together allow CTP Noe to work in such a wide range of settings and platforms, adapt to the physical, link, and network layer dynamics, and still offer highly-reliable and energy-efficient data delivery to the data collection sinks in the network.

About the speaker:
Omprakash Gnawali is a postdoctoral fellow in the Computer Science department at Stanford University. His research interests are network protocols and distributed systems, and their application to wireless and sensor networks. His past research has led to the design and implementation of a widely-used open-source sensor network routing protocol called CTP. He was also involved in the design, development, and deployment of various low-power wireless sensor networks. He received his Ph.D in Computer Science from the University of Southern California and Masters and Bachelors degrees in Computer Science and Engineering from the Massachusetts Institute of Technology.