Soyoung Hwang

Data forwarding based on sensor device constraints in wireless multimedia sensor networks

A variety of data forwarding schemes have been proposed for wireless multimedia sensor networks where energy awareness and reliability are essential design issues. This paper proposes a data forwarding mechanism based on sensor device constraints in wireless multimedia sensor networks. A dynamic path cost function is defined considering the constraints and characteristics of wireless multimedia sensor networks. The cost function is applied to ZigBee mesh routing, and the performance of the proposed method is evaluated using a QualNet network simulator.

Attribute-based routing for home automation networks

This paper proposes an attribute-based routing mechanism for home automation networks. A dynamic path cost function is defined considering the constraints and characteristics of home automation networks. The cost function is applied to ZigBee mesh routing, and the performance of the proposed method is evaluated using a QualNet network simulator.

Network Time Protocol Extension for Wireless Sensor Networks

Advances in smart sensors, embedded systems, low-power design, ad-hoc networks and MEMS have allowed the development of low-cost small sensor nodes with computation and wireless communication capabilities that can form distributed wireless sensor networks. Time information and time synchronization are fundamental building blocks in wireless sensor networks since many sensor network applications need time information for object tracking, consistent state updates, duplicate detection and temporal order delivery. Various time synchronization protocols have been proposed for sensor networks because of the characteristics of sensor networks which have limited computing power and resources. However, none of these protocols have been designed with time representation scheme in mind. Global time format such as UTC TOD (Universal Time Coordinated, Time Of Day) is very useful in sensor network applications. In this paper we propose network time protocol extension for global time presentation in wireless sensor networks.