Yong-Suk Park

Time Coordinated V2I Communications and Handover for WAVE Networks

A wide variety of information technology (IT) services will become available for vehicles through the IEEE 802.11p, IEEE 1609, and wireless access in vehicular environment (WAVE) standards, and naturally the need for service handover will become a necessity. For WAVE networks, a time coordinated medium access control (MAC) protocol named WAVE point coordination function (WPCF) is proposed in this paper. The mathematical derivations and simulation analysis demonstrate that the proposed WPCF protocol can significantly enhance the utilization efficiency and can support more users based on an equal-length access period when compared to point coordination function (PCF), enhanced distributed channel access (EDCA), or hybrid coordination function (HCF) controlled channel access (HCCA) for vehicle to infrastructure (V2I) communications. The paper also demonstrates the effectiveness of the proposed WAVE handover controller (WHC) and WPCF in minimizing service disconnection time when used for V2I handover. In addition, technical enhancements and messages are added to enable seamless communication services over soft-handover (SHO), and enable minimum handover delay in hard-handover (HHO) situations. The mathematical performance evaluation and the simulation results show that the proposed scheme can significantly improve the handover latency compared to the performance that can be delivered by the current protocols.

Implementation of ATSC mobile DTV broadcasting for N-screen smart devices

Most smart devices currently deployed do not include embedded chipset solutions to receive mobile TV broadcasting services. In this paper, a method to enable ATSC Mobile DTV standard based digital broadcasting in multiple smart devices is proposed. The implemented solution uses Wi-Fi and supports iOS and Android OS based platforms.

Adaptive Cloud Offloading of Augmented Reality Applications on Smart Devices for Minimum Energy Consumption

The accuracy of an augmented reality (AR) application is highly dependent on the resolution of the object’s image and the device’s computational processing capability. Naturally, a mobile smart device equipped with a high-resolution camera becomes the best platform for portable AR services. AR applications require significant energy consumption and very fast response time, which are big burdens to the smart device. However, there are very few ways to overcome these burdens. Computation offloading via mobile cloud computing has the potential to provide energy savings and enhance the performance of applications executed on smart devices. Therefore, in this paper, adaptive mobile computation offloading of mobile AR applications is considered in order to determine optimal offloading points that satisfy the required quality of experience (QoE) while consuming minimum energy of the smart device. AR feature extraction based on SURF algorithm is partitioned into sub-stages in order to determine the optimal AR cloud computational offloading point based on conditions of the smart device, wireless and wired networks, and AR service cloud servers. Tradeoffs in energy savings and processing time are explored also taking network congestion and server load conditions into account.

Implementation of a global mobile TV system

This paper presents an implementation of a multi-standard global mobile TV system. Audio, video, and data services provided by the different digital broadcasting mobile TV standards available today are decoded on a single, unified platform.

Interactive services for ATSC mobile DTV based on BWS

This paper presents an interactive data service system for Advanced Television Systems Committee — Mobile/Handheld (ATSC-M/H) digital mobile broadcasting. The system is based on the Broadcast Website (BWS) and Internet is used as a back channel to support interactivity. The system can be considered as an alternative application framework for ATSC-M/H.

Implementation of Stereo Camera Module for Hand Gesture Recognition

This paper presents the hardware and software co-design and implementation of stereo camera module consisting of two image sensor modules and DSP(Digital Signal Processor) for recognizing hand gestures. The DSP based stereo camera module with high resolution and wide angle lens was developed for the hand gesture recognition. In addition, a hand gesture recognition system was developed with the camera module and PC based application. It recognizes the movement and click gesture by analyzing the location and shape change of fingertips in real time

An effective frame detection scheme for OFDM-based portable DRM plus receivers

In OFDM based DRM Plus digital radio system, the difference between the transmitter and receiver oscillator frequencies causes the OFDM symbol timing in the receiver to drift which leads to performance degradation. In this paper, a frame detection scheme robust against OFDM symbol timing changes is proposed and evaluated.

Relative navigation and situation awareness information distribution for GPS information deficient situations

Location information provided by satellite based Global Positioning System (GPS) is used in relative navigation due to its universal availability. However, situations arise where GPS signals become unavailable or its confidence level drops significantly. Under such circumstances, a backup or alternative system for providing location information becomes necessary. In this paper, we propose a robust ground infrastructure based system for relative navigation that can provide location and situational awareness information in case of GPS failure.