Chung-Hsin Liu

Chinese Culture University

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Co-Authors

Sheng-Shiang Chang

Chinese Culture University

Po-Cheng Teng

Chinese Culture University

Wu-Fan Hsu

Chinese Culture University

Chun-Lin Lo

Chinese Culture University

Jian-Yun Lo

National Yang Ming Chiao Tung University

Chung-Min Wu

National Taipei University of Technology

Jiun‐Ting Chen

Shih Hsin University

Chiou‐Yng Lee

Lunghwa University of Science and Technology

Ping-Shin Tsai

Chinese Culture University

Chuen-Lung Chen

National Chengchi University

Cooperative Institutions

Chinese Culture University

National Yang Ming Chiao Tung University

Chunghwa Telecom (Taiwan)

National Cheng Kung University

National Tsing Hua University

National Taiwan University

Hong Kong University of Science and Technology

University of Hong Kong

Chongqing University

Shenzhen University

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CAMEL evolution and PPS evaluation

Chung-Hsin Liu Y.C. Chang Nen-Fu Huang Yu-Lun Ling Hom-Jey Jan

This paper first introduces the Customized Applications for the Mobile network Enhanced Logic (CAMEL) architecture, then presents the CAMEL evolution and CAMEL prepaid service (PPS). We model the SCP call processing, which performs the CAMEL PPS call handing functions. The simulation results illustrate the call processing capability under various traffic conditions.

10.1109/inw.2001.915288

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Citations (1)

Efficiency Evaluation for the 3G and WiMAX

Chung-Hsin Liu Ping-Shin Tsai

When the client moved quickly, from 3G into WiMAX service coverage, then leaved the WiMAX service coverage and accessed to another 3G range of services. At this time, that handoff frequently in a short period of time, and decreased system efficiency, also decreased the QoS. In this research, we use NS-2 to simulate the situations. The final simulation results show that when client moving, should avoid handoff frequently. Because client from WiMAX handover to 3G or 3G handover to WiMAX frequently, that would decreased the QoS.

WiMAX

10.1109/ncm.2009.73

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Citations (0)

The Study of the VoIP through Firewall Security

Chung-Hsin Liu Wu-Fan Hsu

Today Internet is very prosperous. Network firewalls have become basic network security equipments. Not only enterprises will set up firewall system, most of SOHOs and individual users also set up a firewall as a standard device. Because public IP is not sufficient in the IPv4-based environment, so most of networks are using NAT (Network Address Translation) mechanism to translation their private IP. Thus NAT also increases the complexity of VoIP (Voice over IP) through a firewall environment. In order to allow VoIP network environment in normal operation in a firewall environment, IETF and the VoIP industry propose a lot of solution. This article is going to present some common frameworks for analysis VoIP operation and looking forward to provide VoIP normally working in a firewall network environment.

Firewall (physics)

Context-based access control

IPv4

NAT traversal

Private network

DMZ

10.1109/mmit.2010.159

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The study of video conference transmission security as an example on Windows Live

Networked Computing and Advanced Information Management (2010)

Chung-Hsin Liu Wu-Fan Hsu

Today video conference applications are very common in internet. On the other side, network firewalls have become basic network security equipments. Not only enterprises will set up firewall system, most of SOHOs and individual users also set up a firewall as a standard device. In order to allow Video Conference network environment in normal operation in a firewall environment, IETF and the Video Conference industry propose a lot of solution.[1] In this article, we choice Windows Live 2009 software video conference to measure and compare the difference of video image between sender and receiver. Though it does not support ITU-T standard protocol. But Windows Live is still very popular in Instant messaging (IM) field. We forward to provide a common video conference could normally work under a DDoS attack environment.

Firewall (physics)

Communication source

Video Streaming

Source

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Citations (1)

Telemedicine System Designed in Wireless Network Environment

Journal of Convergence Information Technology (2011)

Chung-Hsin Liu WenYen Tseng -

Wireless telemedicine systems have been considered as an important industry in the future. Via a network of this study, many of the features was integrated with the telemedicine system, eg, a number of wireless measuring devices and related information systems, so that patients could have completed care at home or in hospital. In this experiment, we used 802.11g wireless network transmission protocol, and repeated experiment in the same area and to increasing the number of nodes in wireless network. Each wireless node is presented a patient to send out the same packet and data size, also the nodes could randomly move for simulating patients walking in environments. Then through analysis of packet reception rate, the first packet receive time, End to End delay time and throughput, to understand the fixed area can accommodate how many wireless nodes at the same time for transfer data; And telemedicine system still could response the physiological information in real time. It is expected to increase wireless telemedicine system performance of data transmission and save building costs.

10.4156/jcit.vol6.issue10.14

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The analysis on the effectiveness for the handoff of WLAN and ZigBee

Chung-Hsin Liu Sheng-Shiang Chang

The handoff, that is when the user move, quickly, and from within the large scope of the WLAN into smaller and shorter range of ZIGBEE range of services, then leave the ZIGBEE range of services to another WLAN range of services. At this time the vertical short period of time will cause a number of frequently handoff times, resulting in decreased system efficiency, service quality also followed in case of fall. In the study that this is the main interest of using NS2 tool for future situations handoff, the final simulation results will advise the client mobile executive should be an opportunity to avoid the repeated. Because ZIGBEE is increasingly common situation, the costs borne by the user, or not need to cost less. If the number of times within a short time the vertical handoff frequently, it will affect the entire service, number of handoff more times greater the impact.

Scope (computer science)

10.1109/icicis.2010.5534801

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Citations (1)

The effectiveness of the handheld devices based on mobiles learning

Chung-Hsin Liu Wei-Yu Chen

3G mobile devices will make the digital content becomes more compact and portable. The digital content can be carried out at anytime, anywhere. In this study, we build the system for the portable platform of 3G, which can be readily achieved. The contents can be read on a walk, and students use the video calls can be online discussed with their teachers at anytime.

Digital content

10.1145/1655925.1655999

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Citations (2)

The Study for the ZigBee with RFID Positioning System

Chung-Hsin Liu Jian-Yun Lo

This paper is mainly to investigate the positioning technology. We use RFID and ZigBee to increase positioning accuracy in house or interior space. ZigBee technologies have low-cost, low power consumption, small size, easy to fabric construction, etc. Ideally, it suited for short-range wireless transmission of leaving. There are two-way communication is superlative for indoor positioning system. RFID can be through radio signals to identify a specific target, and then read or write data. It does not need identification system and the specific goals established between the mechanical or optical contact. Our Experiments showed that ZigBee devices with RF functionality, the accuracy better than ZigBee-enabled devices. The packet with the RF function devices only needs 0.3s and without RF functions need 0.5s. The transfer function of arrival rate with RF devices reach 95% but without RF-enabled devices is only 73%. Hence that RF enabled ZigBee devices can effectively improve the positioning accuracy.

Indoor positioning system

NeuRFon

Wireless transmission

Hybrid positioning system

10.1109/mmit.2010.156

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Citations (7)

The study for the WLAN with ZigBee positioning system

Networked Computing and Advanced Information Management (2010)

Chung-Hsin Liu Jian-Yun Lo

This paper is mainly to investigate the positioning technology. We use WLAN and ZigBee to increase positioning accuracy in house or interior space. ZigBee technologies have low-cost, low power consumption, small size, easy to fabric construction, etc. Ideally, it suited for short-range wireless transmission of leaving. There are two-way communication is superlative for indoor positioning system. WLAN can be through radio signals to identify a specific target, and then read or write data. It does not need identification system and the specific goals established between the mechanical or optical contact. Our Experiments showed that ZigBee devices with RF functionality, the accuracy better than ZigBee-enabled devices. The packet with the RF function devices only needs 0.3s and without RF functions need 0.5s. The transfer function of arrival rate with RF devices reach 95% but without RF-enabled devices is only 73%. Hence that RF enabled ZigBee devices can effectively improve the positioning accuracy.

Indoor positioning system

NeuRFon

Hybrid positioning system

Source

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Citations (1)

The Study of the Handoff for the Wireless Network

Chung-Hsin Liu

When the client moving very fast, WiMAX service and from within the Wi-Fi access to the scope of services. Then quickly leave the Wi-Fi access to the service area to another within the WiMAX service. At this time will result in a short period of time the number of frequently handoff vertical, Lead to system efficiency decline, service quality has declined with the situation. This study uses the NS2 tools to explore the situation. Finally the simulation results will be proposed mobile client should avoid the implementation of numerous opportunities. Because of the cost for the Wi-Fi users are relatively little or no cost. When the number of vertical handoff frequently in a short period of time, (Wi-Fi handover to WiMAX or WiMAX handover to Wi-Fi), to each handoff will also affect the entire service, the more handoff greater impact.

WiMAX

Scope (computer science)

10.1109/apscc.2008.7

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Citations (9)