Browsing by Author "Chan, Min-Cheng"

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A Cross-Layer Architecture for Service Continuity and Multipath Transmission in Heterogeneous Wireless Networks
(2013)
Chan, Min-Cheng
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Tseng, Chien-Chao
;
Yen, Li-Hsing
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資訊工程學系
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Department of Computer Science
Mobile devices equipped with two or more interfaces can roam across heterogeneous networks. This feature enables the devices to maintain service continuity by performing vertical handovers and to increase transmission capability by exploiting multiple physical transmission paths. However, this type of service continuity is not yet commonly provided. Previous approaches toward the provision of service continuity are limited either in their functionalities or in the scope of cross-layer information. In this paper, we analyze how cross-layer architecture provides service continuity from a broader perspective and propose Cooperative Layered Architecture (CoLA) implemented on Android system for service continuity during handover process. CoLA helps comprehensive information gathering from all layers for handover decisions, provides simple interfaces to make applications mobility-sensitive, and achieves efficient multipath transmissions across heterogeneous wireless links. Experimental results show that CoLA achieves its design goal in providing service continuity.
Jitter-Aware Packet Scheduler for Concurrent Multipath Transmission in Heterogeneous Wireless Networks
(2016)
Chan, Min-Cheng
;
Tseng, Chien-Chao
;
Yen, Li-Hsing
;
資訊工程學系
;
Department of Computer Science
Mobile devices equipped with multiple network interfaces have the potential to increase transmission throughput by exploiting concurrent multipath transmission (CMT). However, packet scheduling for CMT is challenging since the diversity of latencies among transmission paths can easily yield out-of-order packet receptions and cause receiver buffer blocking if the receiver buffer is not large enough. Previous studies proposed several solutions attempting to eliminate out-of-order receptions and receiver buffer blocking. Delay-Aware Packet scheduling (DAPS) is the only one among them that considers delay diversity at the sender side when scheduling packets. However, DAPS assumes quasi-static path delay and thus does not perform well if path delay changes dynamically. In this paper, we analyze how jitter affects the performance of DAPS. Furthermore, we propose and implement a jitter-aware packet scheduler named JAPS. Performance evaluations show that JAPS outperforms existing algorithms in terms of throughput under different settings of data volume, receiver buffer size, network jitter and bandwidth ratio.
Mobility Management for Low-Latency Handover in SDN-Based Enterprise Networks
(2016)
Chen, Ce
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Lin, Yu-Ting
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Yen, Li-Hsing
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Chan, Min-Cheng
;
Tseng, Chien-Chao
Low-latency handover is crucial to real-time traffic in wireless networks. This paper considers an enterprise network managed by emerging Software Defined Network (SDN) technology. For this networking environment, we propose a mobility management scheme named Mobility SDN (M-SDN) that reduces the traffic pause time caused by a host-initiated layer-2 handover. M-SDN performs handover preparation in parallel with the layer-2 handover that involves N-casting of active flows to every potential handover target. Handover preparation is enabled by efficient address resolution and location tracking. We have implemented a prototype of M-SDN and conducted several experiments to evaluate the performance of M-SDN. Experimental results show that M-SDN effectively reduces the impact of layer-2 handovers without any modification on mobile devices.
OpenNet: A Simulator for Software-Defined Wireless Local Area Network
(2014)
Chan, Min-Cheng
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Chen, Chien
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Huang, Jun-Xian
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Kuo, Ted
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Yen, Li-Hsing
This study is motivated by a plan to install a software-defined wireless local area network (SDWLAN) on campus, which possesses a desired property that both data flow and device behaviors can be software-definable. Because the installation involves hundreds of access points, we must conduct simulations beforehand to verify the design and scalability of the target system. However, existing SDN simulator like Mininet does not support modeling of wireless channel and mobility. On the other hand, common network simulator like ns-3 only has limited support for software-defined controllers and does not fully implement handover process. We thus develop OpenNet, which connects Mininet to ns3 to enjoy both Mininet\'s advantage of controller compatibility and ns-3\'s ability in the wireless/mobility modeling. OpenNet also complements ns-3 by adding probe mechanism, which is missing in the current ns-3 implementation. Our simulation result demonstrates the effectiveness of OpenNet.