Browsing by Author "Chen, Yaw-Chung"

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A conflict-insensitive NATed roaming framework using NAToD for proxy mobile IPv4 in WLANs
(2013-07-01)
Jia, Wen-Kang
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
Providing efficient mobility management in the current Internet is increasingly important due to the quick growth of wireless mobile users. The emerging Proxy Mobile IPv4 (PMIPv4) technique brings a possible solution for that purpose. Since NAT function is widely adopted in IPv4 environment nowadays because of lacking IPv4 addresses, the PMIPv4 interoperating with NAT must be considered. Unfortunately, owing to the possible conflict of private IP address, we encounter a problem in broadcasted point-to-multipoint wireless networks such as IEEE 802.11 networks. To address this issue, we proposed a novel Network Address Translation on Demand (NAToD) scheme, which can well interoperate with the PMIPv4 solution. With our scheme, single public IPv4 addresses can be shared by multiple mobile nodes in both home and foreign networks, low-latency handoff can be achieved, deployment cost can be reduced, and software upgrade can be avoided for mobile nodes in wireless LANs. Our work allows mobile users in WLAN to access Internet based on the advantages of both PMIPv4 and NAT.
A cross-layer approach for real-time multimedia streaming on wireless peer-to-peer ad hoc network
(2013-01-01)
Kuo, Jun-Li
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Shih, Chen-Hua
;
Ho, Cheng-Yuan
;
Chen, Yaw-Chung
;
資訊工程學系
Peer-to-peer (P2P) live streaming over mobile ad hoc network (MANET) is a state-of-the-art technique for wireless multimedia applications, such as entertainments and disaster recovery. The peers share the live streaming over MANET via multi-hop wireless link, so an efficient data delivery scheme must be required. However, the high churn rate and the frequent mobility baffle the P2P membership management and overlay maintenance. The unreliable wireless connection of MANET leads to the difficulties of large-scale and real-time streaming distribution, and a lack of overlay proximity leads to the inefficient streaming delivery. We present a cross-layer design for P2P over MANET to manage and maintain the overlay, and select efficient routing path to multicast media streams. Our proposed scheme (COME-P2P) integrates both P2P DHT-based lookup and IPv6 routing header to improve the delivery efficiency. Through the cross-layer design, the low layer detects mobility for informing high layer to refine the finger table, and high layer maintains the efficient multicast path for informing low layer to refine the routing table. How to keep stable routing paths for live streaming via IPv6 routing is the main contribution of this paper. The overlay proximity can shorten routing propagation delay, and the hop-by-hop routing can avoid the traffic bottleneck. Through the mathematical analysis and simulation results, COME-P2P can be demonstrated to achieve high smoothness and reduce signaling overhead for live streaming. (C) 2012 Elsevier B.V. All rights reserved.
A Cross-Layer Design for P2P Live Streaming with Graceful Handover in Mobile IP Network
(2013)
Kuo, Jun-Li
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Shih, Chen-Hua
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Chen, Yaw-Chung
;
資訊工程學系
;
Department of Computer Science
With the development of wireless network and rapidly increasing requirements for mobile computing, peer-to-peer technology on Mobile IP (Mobile P2P) becomes a new focus. Mobile P2P is a more and more interested topic for live streaming in next generation. However, the direct porting of existing P2P application on Mobile IP is difficult to overcome time-critical limitation. Handover under Mobile IP usually leads to overlay failure and session interruption, which lead to long handover delay and intolerable service disruption time. The wireless network has more uncertain dynamics than the wired network, and the dynamics degrade the stable data rate for P2P live streaming. In order to improve the streaming continuity, we propose a cross-layer design to achieve the seamless handover and adjust the playback quality. This article discusses the architecture of present Mobile IP network, and we overcome the challenges to apply P2P service on Mobile IP. The proposed scheme maintains P2P session during IP handover and successfully reroutes packets to the new visited subnet. The motivation is the successful integration of Mobile IP and P2P live streaming, and the goal is the improvement of playback continuity. The simulation results explain that our proposed scheme indeed meliorates the performance of mobile P2P live streaming.
A Cross-Layer Design for Wireless Ad-Hoc Peer-to-Peer Live Multimedia Streaming
(2012-10-01)
Shih, Chen-Hua
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Kuo, Jun-Li
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Chen, Yaw-Chung
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交大名義發表
;
National Chiao Tung University
Establishing peer-to-peer (P2P) live streaming for mobile ad hoc network (MANET) requires an efficient scheme to deliver the real-time data in the infrastructure-less disaster environment. However, P2P membership management is difficult in the dynamic mobility and resource limited MANET. In this paper, we present a cross-layer design for P2P-MANET which integrates P2P DHT-based routing protocol and IPv6 routing protocol. Therefore, the proposed scheme can manage and recover the P2P overlay as well as selecting efficient routing path to multicast video streaming. The simulation results demonstrate that the proposed scheme performs relatively better than the layered approach or the off-the-shelf design in terms of the playback continuity and signaling overhead.
A cross-layer error correction scheme based on multiple-CRC in OFDM/OFDMA wireless networks
(2013)
Chen, Chia-Yao
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Jia, Wen-Kang
;
Chen, Yaw-Chung
;
資訊工程學系
;
Department of Computer Science
The orthogonal frequency division multiplexing access (OFDM/OFDMA) based wireless transmission technology has been widely deployed in recent years. The frame check sequence (FCS) scheme is employed to enhance the reliability of OFDM/OFDMA systems. Since the padding overhead cannot be effectively avoided in OFDM/OFDMA when medium access control frames are encapsulated, we propose a novel cyclic redundancy check based error correction scheme by utilizing the padding space to carry extra segmented FCS information as much as possible; compared with the legacy FCS scheme, our approach greatly enhance the error detection and correction upon the first retransmission (second transmission). A significant performance improvement based on the simulation results is also demonstrated.
A Cross-Layer Media-Independent Handover Scheme in Heterogeneous WiMAX/WiFi Networks
(2010-01-01)
Huang, Yue-Huei
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Chen, Yaw-Chung
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交大名義發表
;
National Chiao Tung University
The main challenges in the development of future wireless communication systems are provisioning various services across different radio access technologies to mobile users with satisfactory quality of services. However, as a mobile user moves across network boundaries, the seamless service over heterogeneous networks would be an important concern. To minimize the disruption to the ongoing session while a mobile user is moving from one access network to another, we propose a framework that integrates IEEE 802.11 WLANs and IEEE 802.16 WMANs based on the IEEE 802.21, also called Media Independent Handover (MIH), to facilitate both homogeneous and heterogeneous handovers. Performance evaluation and comparisons have been done through both mathematical analysis and simulation on ns-2 simulator.
A Cut-through Scheduling for Delay Optimization in TD-LTE Relay Enhanced Networks
(2017-01-01)
Jia, Wen-Kang
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
The relaying is the most important feature as a practical solution in LTE technologies to improve performance and to extend coverage. This paper contributes to the performance on cut-through forwarding mode in relaying framework for applying in TD-LTE standard referred to as 3GPP release 10 and above, it provides lower forwarding latency per hop by rescheduling the alignment of sub-frame duration between each superordinate relay node and subordinate relay node. We demonstrate a significant performance improvement through simulation, the results show that the proposed scheme features lower forwarding latencies for both uplink and downlink in terms of one-way end-to-end delay as compared to legacy synchronous relaying of the relay enhanced TD-LTE networks.
A Hardware-based Preemptive Dynamic Bandwidth Allocation Mechanism for Real-time Applications in EPONs
(2012-01-01)
Jia, Wen-Kang
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Yang, Yuan-Rung
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Chen, Yaw-Chung
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資訊工程學系
;
Department of Computer Science
with the emergence of Ethernet as a convergence layer in access network, Ethernet Passive Optical Network (EPON) has evolved. It is being considered as a promising solution to the "last mile" problem in next-generation broadband access network. An EPON is a point-to-multipoint tree topology, which carries 802.3 Ethernet frames between an optical line terminal (OLT) and multiple optical network units (ONUs) via a passive optical splitter. The multi-point control protocol (MPCP) for medium access control (MAC) in an EPON. In this paper, we investigate design issues for access networks based on passive optical network technology, and we present a preemptive transmission mechanism that works on MAC and PHY layer of OLT and ONU components. We conduct detailed simulation experiments to study the performance and validate the effectiveness. The proposed novel scheme effectively reduces the frame queuing delay as well as jitter, so as to enhance system throughput.
A Hybrid CPU/GPU Pattern-Matching Algorithm for Deep Packet Inspection
(2015-10-05)
Lee, Chun-Liang
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Lin, Yi-Shan
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
The large quantities of data now being transferred via high-speed networks have made deep packet inspection indispensable for security purposes. Scalable and low-cost signature-based network intrusion detection systems have been developed for deep packet inspection for various software platforms. Traditional approaches that only involve central processing units (CPUs) are now considered inadequate in terms of inspection speed. Graphic processing units (GPUs) have superior parallel processing power, but transmission bottlenecks can reduce optimal GPU efficiency. In this paper we describe our proposal for a hybrid CPU/GPU pattern-matching algorithm (HPMA) that divides and distributes the packet-inspecting workload between a CPU and GPU. All packets are initially inspected by the CPU and filtered using a simple pre-filtering algorithm, and packets that might contain malicious content are sent to the GPU for further inspection. Test results indicate that in terms of random payload traffic, the matching speed of our proposed algorithm was 3.4 times and 2.7 times faster than those of the AC-CPU and AC-GPU algorithms, respectively. Further, HPMA achieved higher energy efficiency than the other tested algorithms.
A Novel Optical Code-Based Label Switching Architecture for WDM Packet Switched Networks
(2010-12-01)
Wang, Zhao-Wei
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Liang, Man-Gui
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Jia, Wen-Kang
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Chen, Yaw-Chung
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資訊工程學系
To cope with ever-increasing traffic demands in transport networks, all-optical switching is currently perceived as a solution to remove bottlenecks imposed by O/E/O conversions. Optical label switching accomplishes packet switching using the optical-labels. It simplifies the design of switching devices in the optical domain and speeds up packet forwarding significantly. In this paper, we propose a novel design of optical switches, and present a performance analysis to show its in-depth behavior. The analysis results demonstrate the effectiveness of the proposed switching architecture.
A Novel Optical Code-Based Label Switching Architecture for WDM Packet Switched Networks
(2010-12-01)
Wang, Zhao-Wei
;
Liang, Man-Gui
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Jia, Wen-Kang
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Chen, Yaw-Chung
;
資訊工程學系
To cope with ever-increasing traffic demands in transport networks, all-optical switching is currently perceived as a solution to remove bottlenecks imposed by O/E/O conversions. Optical label switching accomplishes packet switching using the optical-labels. It simplifies the design of switching devices in the optical domain and speeds up packet forwarding significantly. In this paper, we propose a novel design of optical switches, and present a performance analysis to show its in-depth behavior. The analysis results demonstrate the effectiveness of the proposed switching architecture.
A Redundancy-Free Reliable Multicast in Wireless Multi-hop Relay Networks
(2011)
Chen, Chia-Yao
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Jia, Wen-Kang
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Yang, Yuan-Rung
;
Chen, Yaw-Chung
;
資訊工程學系
The Orthogonal Frequency Division Multiplexing Access (OFDM-based) wireless transmission technology is widely deployed nowadays, and Frame Check Sequence (FCS) scheme is used to enhance the reliability of OFDM-based systems. Since the padding overhead cannot be effectively avoided in OFDM-based system when MAC frames are encapsulated, we propose a novel CRC based error correction scheme by utilizing the frame padding overhead to carry extra segmented FCS information as much as possible; compared with legacy FCS scheme, our approach achieves a significant improvement in error detection and correction for the multicast frame in transparent mode multi-hop relay network. We demonstrate a significant performance improvement based on the mathematical analysis.
A Scalable Source Multipath Routing Architecture for Datacenter Networks
(2015)
Jia, Wen-Kang
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Liu, Gen-Hen
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
The continuous growth in traffic volumes on modern Data Center Networks (DCNs) can be classified into either delay-or throughput-sensitive applications. In order to providing quality delivery to such applications, it is important that multipath routing and/or forwarding can be supported in the DCNs. However, some inherent problems of multipath forwarding have not been totally solved by existing solutions. Aiming to balance all these requirements for the multipath DCNs, we propose a novel solution-Code-Oriented eXplicit MultiPath (COXMP) scheme which evenly distributes traffic along multiple paths, resulting in better network throughput, delay, jitter, and resilience. The simulation results show that COXMP outperforms existing solutions and achieves a reasonable tradeoff between scalability and overhead.
A self-adjusted buffer control for P2P live streaming
(2010)
Kuo, Jun-Li
;
Shih, Chen-Hua
;
Chen, Yaw-Chung
;
交大名義發表
;
National Chiao Tung University
Real-time multicast live streaming system can use peer-to-peer (P2P) technology to keep stability and scalability without any additional support from the underneath network. Our proposed scheme focuses on the mesh architecture of P2P live streaming system and uses dynamic buffer to substitute the traditional fixed buffer owning a limit of quality of service (QoS). According to the simulated results, the self-adjusted dynamic buffering mechanism can adjust buffer to avoid the frozen or reboot of streaming based on the input data rate and it is suitable for the violently dynamic P2P environment. Hence, our proposed scheme can be workable because the modification of buffering mechanism varies the existing P2P live streaming system less to improve quality of experience (QoE) more.
A Study of QoS Feedback Schemes on WiFi Multicast for Media Streaming Services
(2016)
Chen, Yaw-Chung
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Liao, Chun-Yu
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資訊工程學系
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Department of Computer Science
Nowadays multimedia streaming is running on mobile devices under WiFi networks. To send the same media stream to multiple receivers, multicast is usually considered for efficient data transmission. Since multicast frames won\'t be acknowledged, it is difficult to evaluate the QoS of data delivery over WiFi. In this work, we proposed a so called Statistic Collection multicast scheme based on X-beacon mechanism and corresponding MAC management messages for WiFi multicast. Our work features the following characteristics: (1) implements acknowledgement for multicast, (2) improves awareness on WiFi multicast, (3) measures transmission power and performs power-adjustment, and (4) extends the coverage for all receivers.
A Study on Content Delivery Strategy for QoE Enhancement in P2P IPTV
(2014-01-01)
Huang, Yu-Wei
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Chen, Yaw-Chung
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資訊工程學系
;
Department of Computer Science
Nowadays the peer-to-peer (P2P) systems have been widely deployed for the Internet television and live streaming. The real-time P2P service features advantages of scalability and heterogeneity in the existing network without modifying the underlay infrastructure. However, most of the common IPTV applications did not consider the user's surfing behavior which causes great burden to the IPTV streaming system. In addition, the high churn rate and insufficient upload capacity may lead to the unstable playback smoothness, and result in a poor quality of experience (QoE). In this paper, we propose a QoE-aware content delivery mechanism to distribute the important and instant data first. I-frame chunks near playback deadline are assigned the top priority. We discuss the comparison of overlay performance and demonstrate that the proposed scheme is workable via a series of experiments on OMNeT++.
A Teletraffic Perspective on Relay-Node Selection Strategy in VoP2P System
(2009)
Jia, Wen-Kang
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
This paper gives a theoretical approach to modeling and simulating the Grade of Service (GoS) of Voice over Peer-to-Peer Session Initiation Protocol system which is created based on various teletraffic parameters. VoP2P features a particular service characteristic due to its different GoS models originated from circuit switched telephone networks. Especially, most voice session in VoP2P is indirectly connected because peer-nodes usually locate behind NATs. This situation forces peer-node to select one or more relay-node for establishing sessions. However, the relay-node is a constrained resource because every relay-node can only support very limited relay services in VoP2P network. There are two strategies, the S(2)RS (Staged Single-Relay Strategy) and MRS (Multi-Relay Strategy), to solve the relay-node issue. We adopt three new parameters in VoP2P call-loss models, the first is callee-attendance rate, which is due to the characteristic of destination peer-nodes with a lower attendance probability; the second is call-blocking rate, which is a traditional definition just because the relay-node reaches the limitation of resource; the third is handoff-dropping rate (aka handoff-loss rate), which is caused by the relay-node being removed frequently. The simulation results provide useful reference in the study of teletraffic of VoP2P system.
A Virtual Cluster Head Election Scheme for Energy-Efficient Routing in Wireless Sensor Networks
(2015)
Tsai, Ming-Yu
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
In emerging IoT era, Wireless Sensor Networks, aka WSNs are deployed for gathering data in various environments, in which efficient cluster routing mechanisms are deployed to prolong the network lifetime and improve the stability. Most existing studies focus on homogeneous WSNs. Some research workes achieved good performance based on the assumption of equal initial power and/or predefined ratio in types of node, these mechanisms are not flexible. Besides, existed works rarely deal with cluster head distribution. LEACH-C achieved the best cluster head distribution with a built-in GPS receiver in all sensors, but much higher cost and complexity are significant drawbacks. In this work, we proposed a Virtual Cluster Head Election Scheme that provides an energy-efficient clustering algorithm and considers cluster head distribution in WSNs. Simulation results show that our scheme balances the distribution of cluster heads and chooses those sensors with relative higher energy as cluster heads, and achieves a remarkable improvement on both network lifetime and data throughput.
Advanced bootstrap and adjusted bandwidth for content distribution in peer-to-peer live streaming
(2015-05-01)
Kuo, Jun-Li
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Shih, Chen-Hua
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Ho, Cheng-Yuan
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Chen, Yaw-Chung
;
資訊工程學系
Today peer-to-peer (P2P) systems have been deployed for various Internet multimedia applications such as live video streaming service. However, both peer churn and upload capacity insufficiency are inherent problems causing long start-up delay and unstable playback quality. Therefore, we introduce a scalable application-layer multicast algorithm, ABCD-P2P, which inherits the short end-to-end delay and low control overhead due to the push delivery scheme. The logical overlay is close to the physical topology (i.e., geographic proximity) in ABCD-P2P, so a short streaming multicast delivery path reduces the number of hops and avoids the network bottleneck or far routing. Both an advanced bootstrap mechanism and an adjusted bandwidth mechanism are suitable for the asymmetric bandwidth network. The mathematical analysis and simulation results demonstrate that our proposed scheme can achieve the goals of high playback smoothness, short start-up delay, short end-to-end delay, low control overhead, and short recovery time.
ALEX: An Arithmetic-based Unified Unicast and Multicast Routing for MANETs
(2014)
Jia, Wen-Kang
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Chen, Chia-Yao
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Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
Explicit multicasting protocols such as Differential Destination Multicast (DDM) in MANETs have been retaining advantages of traditional approach while eliminating their shortcomings especially for small-group applications. However, they still have some drawbacks especially in the group size limitation. In this work we discussed a new unified unicast and multicast routing scheme called Arithmetic Labeled EXplicit (ALEX) Multicast Routing based on arithmetic encoding of on tree node keys and recursive unicast for MANETs. Our scheme constructs the multicast tree by decoding the bitmap of its output ports for next hops in the forwarding path using a common Multicast Channel Mentifier (MCID) and a node-specific key, so that multicast packets can be self-routed to multiple receivers without requiring header modification, and intermediate nodes on the multicast mesh will be stateless. In addition to scaling up the multicast group size, our scheme can reduce the processing complexity, control overhead and delivery latency comparing to the existing works. The simulation results indicated that our proposed scheme achieves a remarkable improvement in scalability while simplifying the deployment and management for a large number of medium-size multicast groups in MANETs.