Hyo-Joong Suh

Advanced Primary–Backup Platform with Container-Based Automatic Deployment for Fault-Tolerant Systems

Within mission-critical systems, the primary–backup scheme is a desirable approach for improving reliability and fault tolerance. It can be used to ensure a high mission success rate despite unexpected errors. However, it must cope with the need to maintain consistency between a primary and a backup whenever the primary encounters unexpected errors. We overcome this issue by introducing a platform that uses container-based light virtualization and an automatic build system to isolate an application so that it may then be deployed on different devices without manual intervention. We believe an advanced deployment procedure can retain the consistency of the primary–backup systems with low implementation complexity. Integrated with a cloud application, it can also manage mission-critical systems effectively, communicate with the redundant systems, and detect unexpected errors by using sophisticated fault-detection technologies. We demonstrate that the platform can improve the reliability of mission-critical systems through realistic experiment using a model electronic vehicle and can reduce hardware dependencies.

Implementation of 3GPP RLC Testbed for Protocol Verification and Evaluation

The connection based TCP protocol provides reliable packet delivery, but it takes certain overhead compare to the connection-less UDP protocol. Thus, 3GPP devise the upper-layer RLC protocol which provides reliability based upon the UDP protocol. Consequently, each implement of a base station and/or mobile terminal require the development of the RLC protocol, and it must qualify various interoperable tests. In this paper, we implement a testbed which verifies the RLC protocol under various packet losses/inversion circumstances of networks. Finally, we propose our testbed as the RLC protocol tester for the developments.

Robust Delay Control for Audio Streaming over Wireless Link

The audio delay is becoming an important factor in audio streaming over short-range wireless network. In this study, we propose an efficient two-level delay control method, called frame sequence adaptation and audio sampling frequency compensation, for achieving stable audio delay with a small variation. To prove the effectiveness of our scheme, we implemented and evaluated the scheme on a Bluetooth network. Experimental results show that our scheme can control audio delay robustly and remove phase shift problem in multi-channel stereophonic audio broadcasting as well.

Poster: Conservative Modulation and Coding for Low-latency Robust Transmission of Scalable ECG over LTE MTC

This study introduces a novel conservative modulation and coding scheme to minimize and stabilize the delay incurred during the process of electrocardiogram (ECG) transmission over a wireless medium, while maintaining the desired level of the ECG pattern quality required for improving the chance of its interpretation. A machine-type communication system is adopted for the delivery of ECG data to benefit from its inherent reliability, pervasiveness, security, and performance of 4G long-term evolution technologies with reduced cost and enhanced coverage. Extensive evaluations indicate that the proposed system provides a sufficient level of service for medical-grade instantaneous ECG monitoring even under significantly deteriorated channel conditions.

Implementation of Verification and Evaluation Testbed of WiMax2 PKMv2 Encryption Layer

PKMv2 security protocol was adopted by the WiMax2 mobile internet communication standard. A base station and a mobile station protect communication data using key based encryption according to the PKMv2 protocol. Consequently, each development of a base station and/or mobile station includes implement of the PKMv2 protocol, and the station must qualifies various interoperable tests. Furthermore, communication bandwidth of the station can be limited by the encryption module when the station implemented based on a low-performance processor. Thus, a correspondence measurement of the encryption module must be carried on the target processor. In this paper, we implement a testbed which affords throughput measurement as well as the interoperable tests by PKMv2.

Analysis of Autonomous Bandwidth-Delay-Balancing Characteristic in the Decay Usage Scheduler

The decay usage scheduler pursues long-term fairness in terms of both service bandwidth and service delay, in contrast to GPS (generalized processor sharing)-based schedulers pursuing short-term fairness only in terms of service bandwidth. Due to this bandwidth-delay-balancing characteristic of the decay usage scheduler, I/O-bound interactive processes are preferred to CPU-bound processes, resulting in fairness and better system utilization autonomously. However, there is no firm understanding of the mixed effects of the decay usage parameters on the service performance. This paper empirically analyzes their effects in terms of the resulting service bandwidth and service delay. Such analysis and understanding provides a basis of controlling the decay usage parameters for desirable service provision as required by applications.

Development of a VoWLAN Terminal based on Open Source Software

In this paper, we developed a VoWLAN(Voice over WLAN) system based on an open source software. The system aims to provide VoIP service over wireless LAN with an IP-PBX server. The features of system presented in this paper are as follows. First, the initial cost for the development is reduced since the system is developed based on open source software. Second, the system provides various additional services such as Voice Mail, Conference Call, and Interactive Voice Response with a software IP-PBX server. Third, the VoWLAN terminal provides high-level user applications with minimal system resources using lightweight open software solutions. Finally, it is highly scalable since it is based on the open source software.

RISC/DSP dual core wireless soc processor focused on multimedia applications

The key technology of the mobile multimedia application is System-On-Chip processor that integrates the major function unit with low power consumption using a small battery. The wireless communication is practical technology, which makes comfortable communications between devices, such as IEEE 802.11a/b/g and Bluetooth. By the modern streaming technology with compression, like mpeg, the wireless communication triggers high quality media service without wires. The wireless communication spend a quite large portion of energy of mobile device if data flows continuously, hence a delicate energy control may needed to fulfill a saving of the limited energy. Due to these issues, integrating the wireless function units into the high performance embedded processor supports a seamless control of power consumption of wireless part, and the communication data flows are sealed in the SoC chip, which reduces inter-chip communiaction energy between a main processor and a wireless media access controller. We focused the high performance wireless multimedia applications are suffered by the energy consumption, so we alleviated the power issue by integrating of IEEE 802.11a/b/g media access controller, modem, ADC/DAC, high performance DSP, and RISC core in a silicon. We present a wireless capable SoC processor, GDM5104, that integrated the multiple wireless media access controller as well as CCK/ OFDM/ GFSK modem and ADC/DAC also. Furthermore, the processor integrates RISC and DSP independent cores with appropriate caches, and rich peripherals that sufficient to implement mobile multimedia applications, hence the processor exhibits wireless connectivity with low power consumption. The processor is fabricated in a 0.18um standard CMOS technology, and operates at 133MHz RISC, and 100MHz DSP, which provides full capability of wireless multimedia processing.