Jeong-sik In

Design and Implementation of Energy-Efficient and Secure Framework for Wireless Sensor Networks

Many applications in wireless sensor network (WSNs) require energy efficiency. In addition, recently increasing applications sometimes include very sensitive information such as personal related information, and individual health data. However, existing works have not satisfied these requirements of WSN applications. In this paper, we propose an energy-efficient and secure framework for WSNs, which is CSMA and TDMA hybrid approach and provides the multi-channel TDMA based active/sleep scheduling with it. It also includes the security related functionalities to employ a flexible security suite to packets dynamically. We describe the design and implementation of this framework and show the effectiveness of our system by experiments.

The resource optimization of heterogeneous network interfaces in wireless mobile devices

Although using high-quality streaming services becomes more common on mobile devices, the increment of streaming quality, which generally requires the larger playback bandwidth, frequently incurs undesirable delays or jitters that hamper user experiences. Recent mobile devices usually equip multiple network interfaces and their concurrent utilization can be beneficial to retain the necessary bandwidth. This, however, requires the more energy consumption of mobile devices whose resource is limited due to battery-based operations. For this reason, streaming performance and energy consumption should not be independently considered. Under multiple network interface utilization, we investigate the characteristics of each component, based on two-level convex optimization, and propose a solution to optimize them together. The algorithm is tested on Android phone where LTE and Wi-Fi networks are concurrently enabled. Compared to LTE only method, it shows that the proposed approach can obtain 1.8 times good-put increment only with the half amount of energy consumption. Our approach can be utilized for almost all mobile devices without server-side modifications.