Wireless Sensor Networking Source Book - Millennial Net
Wireless Sensor Networking Source BookA Guide to the Fundamentals of Wireless Sensor Networksby Sokwoo Rhee, Ph.D.andSheng Liu, Ph.D.Version 1.0 January 2005© 2005 Millennial Net, Inc. All rights reserved.
About the authorsSokwoo Rhee, Ph.D., was a research associate at MIT focusing on wireless biomedicalinstrumentation. His research led to the development of a sensor ring that measures thewearer’s vital signs. The practical application for this ring was nursing home resident care.Residents would wear the rings to monitor their temperature, heart rate, and oxygen saturation;the data would be transmitted continuously to a base station. The small size requirementsof the ring necessitated a small battery. While a coin cell battery would fit the bill interms of size, there were power consumption and mobility challenges still to be met. Forpractical reasons, the battery would need to run for months not days, the transmission rangewould need to cover the entire nursing home facility, and the data transmission would needto support mobile residents. Sokwoo began researching mesh networking as the approach toaddress the requirements and bring the application from a good idea to a practical solution.Sheng Liu, Ph.D., spent five years as a research scientist at MIT, directing industry-sponsoredresearch programs in the areas of controls, robotics, simulations, signal processing,and mechatronics. He then went to Raytheon where, as Senior Development Engineer, heplayed a critical role in designing receiver spread-spectrum decoding algorithms for differential-GPSbased aircraft precision approach and landing systems.In 2000, Sokwoo and Sheng joined forces. Sheng’s experience in autonomous systems analysis,dynamic programming, and algorithm development combined with Sokwoo’s work onthe practical biomedical sensor application resulted in the development of a set of innovativetechniques to meet the practicality needs of the ring sensor. These techniques broke groundin reducing power consumption, extending transmission distance, and managing a dynamic,mobile network with a high degree of reliability. The result was a wireless sensor networkingprotocol that was applicable across a wide spectrum of applications. With this breakthroughprotocol, Sowkoo and Sheng founded Millennial Net, Inc. and developed and commercializedthe Millennial Net wireless sensor networking platform.Today, as chief technology officer and vice president of research respectively, Sokwoo andSheng continue to lead the industry in developing innovative technologies to enable MillennialNet’s customers develop practical wireless sensor networking-enabled applications.