Browsing by Author "Lin, Pin-Jen"

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A performance study for IPv4-IPv6 translation in IP multimedia core network subsystem
(2010-08-01)
Chen, Whai-En
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Lin, Pin-Jen
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資訊工程學系
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Department of Computer Science
A Next Generation Network (NGN) is an advanced, packet-based network that exploits broadband and QoS-enabled transport technologies for enabling multimedia services. In NGNs, the principles and requirements of IP Multimedia Sub-system (IMS), which are used to deliver the desired benefits, should be carefully examined and studied. Internet Protocol version 6 (IPv6) is adopted by Third-generation Partnership Project (3GPP) to solve address storage problem and provide new features (e.g. plug-and-play and mobility) for IMS. However, in the early stage of IPv6 deployment, the existing Voice-over-IP (VoIP) networks support Internet Protocol version 4 (IPv4) only. For IPv4 IPv6 interworking between IMS and the existing VoIP networks, the IMS-Application Level Gateway (IMS-ALG) and the Transition Gateway (TrGW) are proposed to translate Session Initiation Protocol (SIP) and Real-time Transport Protocol (RTP) packets, respectively. In this paper, we focus on the IPv4 IPv6 translation for RTP packets, which is the bottleneck of VolP performance. Specifically, we developed a TrGW called National Information and Communications Initiative (NICI)-TrGW. In NICE-TrGW, we perform IPv4 IPv6 translation at the Linux kernel and adjust the header room of kernel-level packet buffer for each packet to reduce memory-copy operations. We evaluate the performance of NICI-TrGW and the existing solutions by using the SmartBits. Our study indicates that NICI-TrGW outperforms the existing solutions in terms of three different output measures including packet loss rate, maximum throughput, and average latency. Copyright (C) 2009 John Wiley & Sons, Ltd.
An IP-Based Packet Test Environment for TD-LTE and LTE FDD
(2014-03-01)
Lin, Pin-Jen
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Lin, Yi-Bing
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資訊工程學系
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Department of Computer Science
In recent years, Long Term Evolution systems have been developed to replace 3G mobile networks. During LTE network deployment, it is essential that mobile operators and manufacturers conduct tests on user equipment and the base station (eNB). Besides conformance testing at the radio layer, it is also important to conduct network-layer performance tests between UE and eNB. This article develops an LTE test environment that can be used to test the IP-based packet performance for TD-LTE and LTE FDD. Specifically, we consider the latency and the throughput performance of IP, TCP, and VoIP (i.e., G.711) packet delivery. This multi-purpose test environment can be utilized to investigate the performance of the UE and/or eNBs of various manufacturers. Furthermore, we use this environment to compare TD-LTE and LTE FDD. The measurement results provide guidelines for UE and eNB vendors to improve their products, and operators to deploy their LTE networks and subsidized UE devices.
PERFORMANCE MEASUREMENTS OF TD-LTE, WIMAX AND 3G SYSTEMS
(2013-06-01)
Lin, Yi-Bing
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Lin, Pin-Jen
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Sung, Yingrong Coral
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Chen, Yuan-Kai
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Chen, Whai-En
Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX) are two major technologies toward next-generation mobile broadband standards, which are both expected to provide higher throughput and lower transmission latency for mobile users. This article measures and compares the latency and the throughput of Time Division - Long Term Evolution (TD-LTE), WiMAX, and third-generation (3G) systems based on several technical trials. Our quantitative measures and comparisons provide guidelines for the operators to deploy their future networks.
Real-Time VoIP Quality Measurement for Mobile Devices
(2011-12-01)
Chen, Whai-En
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Lin, Pin-Jen
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Lin, Yi-Bing
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資訊工程學系
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Department of Computer Science
The quality of voice over Internet protocol (VoIP) is typically measured by mean opinion score (MOS) that significantly varies in wireless environments. Several approaches have been proposed to evaluate the MOS values of voice paths. However, these solutions require extra servers/gateways to conduct heavy computation for MOS measurement of VoIP calls. We propose two MOS measurement procedures for mobile devices. In our approach, a simple program is installed in each of the mobile devices (through an app-store like mechanism). In the perceptual evaluation of speech quality (PESQ) MOS measurement procedure, a lightweight real-time table lookup solution significantly reduces the computation time of PESQ MOS measurement from 315.4 s to 3 s. In the E-model MOS measurement procedure, the E-model MOS value can be accurately computed in 5.35 s.