Browsing by Author "Lin, Tzu-Ming"

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A Simple and Efficient Data Forwarding Mechanism In Wireless Relay Networks
(2009)
Chen, Wen-Tsuen
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Lin, Tzu-Ming
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Tsao, Shiao-Li
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資訊工程學系
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Department of Computer Science
Wireless relay network Is a low-cost solution for extending the service coverage and increasing the throughput of the conventional single-hop wireless network. By deploying a relay network, a base station (BS) can provide services to subscriber stations (SSs) through relay links. The functionality of a relay station (RS) is simpler than a BS, and RSs only forward packets between SSs, RSs and the BS without too much packet processing. However, current solutions require a RS to store and process the packet before it can determine the destination, and thus introduce extra processing and buffering overheads on the RS. This study proposes a simple and efficient forwarding scheme which multiplexes bursts to the SSs attached to the same access RS. By applying the proposed end-to-end burst switching mechanism, the RS merely checks the frame header and can decide the final destination without packet processing. The experiment results demonstrate the superior performance of the proposed scheme than other approaches.
An Efficient Automatic Repeat Request Mechanism for Wireless Multihop Relay Networks
(2013-07-01)
Lin, Tzu-Ming
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Chen, Wen-Tsuen
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Tsao, Shiao-Li
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資訊工程學系
;
Department of Computer Science
Recently, relay technology has been adopted to enhance the coverage and performance of wireless networks such as Worldwide Interoperability for Microwave Access and Long-Term Evolution Advanced (LTE-A). However, using relays to forward packets may induce more packet losses than traditional single-hop wireless networks because transmissions are conducted through multiple radio links. When there are lost packets, relay stations (RSs) decide whether to retransmit these packets with automatic repeat request (ARQ) strategies. We observe that an improper ARQ strategy increases latency, blocked packets, and workloads on the multihop relay network. This paper proposes a new relay ARQ (RARQ) scheme, providing efficient acknowledgement to reduce packet latency and the number of blocked packets with small workloads. We also propose an analytic model to evaluate the performance of the proposed mechanism. Simulation results have validated the proposed model and demonstrated that our ARQ scheme outperforms conventional approaches.
Energy Conserving Packet Transmission Schemes for Video and Voice over WLAN
(2006)
Tsao, Shiao-Li
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Huang, Chung-Huei
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Lin, Tzu-Ming
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資訊工程學系
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Department of Computer Science
The design of packet transmission mechanisms of video and voice over wireless networks generally utilizes the characteristics of real-time data to improve the network performance, the energy efficiency of mobile devices, and etc. Unfortunately, WLAN medium access control (MAC) layer does not distinguish real-time and data packets during MAC frame transmission, and this design introduces network overheads and extra power consumption of video and voice over WLAN (V(2)oWLAN) stations (STAs). In this paper, we propose a transmission scheme to eliminate WLAN MAC acknowledgment frames of real-time packets dynamically in order to reduce the power consumption of V(2)oWLAN STAs and to improve the network utilization without sacrificing video and voice qualities. The proposed transmission scheme utilizes the WLAN multicasting method that does not require MAC acknowledgment, and the method thus can be implemented on the existing WLAN infrastructures by only software upgrades. Simulation results demonstrate that the proposed scheme improves the network utilization and the energy efficiency of V(2)oWLAN applications.