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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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🏛️國立陽明交通大學機構典藏

Author: search.filters.author.Wang, Shie-Yuan

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Now showing 1 - 10 of 44
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    Improving the Localization Accuracy for Sigfox Low-Power Wide Area Networks
    (2019-01-01)
    Wang, Shie-Yuan
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    Cheng, Yu-Hsiang
    ;
    Tarng, Jenn-Hwan
    ;
    交大名義發表
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    資訊工程學系
    Sigfox is a new LPWAN (Low-Power Wide Area Networks) wireless technology proposed for IoT applications. Its transmit power is only 22.5 dBm, but its wireless transmission range can be up to 30 km in open space. In this paper, we propose a new machine learning-based localization method to predict the location of a Sigfox module. Our method divides the space around each base station into a few sectors and trains a more accurate path-loss-to-distance model for each sector to reflect its site specific multipath propagation environment. Our experimental results measured in a big city show that the maximum distance errors of our method are much smaller than those of the official Sigfox localization service in many cases.
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    Parallel Running and Comparing the Behavior of Two Identical Network Servers
    (2019-01-01)
    Wang, Shie-Yuan
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    Huang, Po-Han
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    資訊工程學系
    ;
    Department of Computer Science
    In this paper, we design, implement, and evaluate the functions and performance of a parallel running and comparing system that is built on OpenVswitch software switch. Parallel running is a very important method to change from an existing system to a new system. The conversion usually occurs when the technology of the old system is outdated and a new system needs to be installed to replace the old one. During parallel running, both the old and new systems are running side by side and their behavior are compared against each other until the users are certain that the new and old systems behave exactly the same. At that time, the old system will be removed and the new system will totally replace the old system. In this paper, we use the OpenVswitch to design and implement a comparing system for parallel running Our system has many useful features and can be applied to real mission-critical systems.
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    Building A Prototype of a Pair of Weighing Shoes Based on Machine Learning Techniques
    (2019-01-01)
    Wang, Shie-Yuan
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    Jenp, En-Yu
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    Hsu, Ya-Jen
    ;
    資訊工程學系
    ;
    Department of Computer Science
    Changes in the human body weight may be caused by diseases, overeating, lack of exercise, or other health problems. In this paper, we built a prototype of a pair of weighing shoes to enable people to constantly monitor their weight changes so that they can detect and treat their health problems earlier. We placed several thin and flexible pressure sensors under the shoes and used machine learning techniques to learn the relationship between their values and the actual weight of the human body being measured. The trained model then was used to predict the weight of a human body. In our experiments, we varied the number of used pressure sensors to study its impact on the prediction error. We found that the prediction error of the trained model could be controlled within 5.8% when 8 or more pressure sensors were used for the current prototype.
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    Design and Implementation of TCP-Friendly Meters in P4 Switches
    (2020-08-01)
    Wang, Shie-Yuan
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    Hu, Hsien-Wen
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    Lin, Yi-Bing
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    資訊工程學系
    ;
    Department of Computer Science
    Metering the traffic of a flow and dropping the portion of traffic that exceeds the target rate set by the meter is very important to provide quality of service (QoS) in a network. Most existing switches on the market provide the meter function. Although these meters regulate the traffic of a UDP flow very well, according to our tests, they are not TCP-friendly. For example, we found that a TCP flow passing the meter of a commercial switch can only achieve about 10% of the target rate. Based on our studies, we found that this poor performance is due to the bad interactions between the TCP congestion control and the meter function. In this paper, we design and implement a TCP-friendly meter in the packet processing pipelines of a P4 switch. Experimental results show that our meter regulates a TCP flow very well and can maintain its achieved rate within 5% of the target rate. Compared with the meters in several hardware switches, our meter improves the achieved rate of a TCP flow by almost 85% of the target rate.
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    A Bandwidth-Efficient INT System for Tracking the Rules Matched by the Packets of a Flow
    (2019-01-01)
    Wang, Shie-Yuan
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    Chen, Yo-Ru
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    Li, Jun-Yi
    ;
    Hu, Hsien-Wen
    ;
    Tsai, Jia-An
    Tracking the rules matched by the packets of a flow when they traverse multiple switches in a network is very important and useful. In this paper, we design and implement a bandwidth-efficient In-Band Network Telemetry (INT) system that can track the rules matched by the packets of a flow in real time or in the past. We have evaluated the real performance of our system on a testbed composed of several hardware P4 switches. Our experimental results show that the system works correctly and its traffic reduction scheme can reduce the rate of generated INT reports by a factor of 39, 394, 2,055, or even up to 12,500, depending on the type of network states monitored and the threshold used to filter out less important INT reports.
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    Aggregating and disaggregating packets with various sizes of payload in P4 switches at 100 Gbps line rate
    (2020-09-01)
    Wang, Shie-Yuan
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    Li, Jun-Yi
    ;
    Lin, Yi-Bing
    ;
    資訊工程學系
    ;
    Department of Computer Science
    Aggregating multiple small packets into a large packet provides many advantages. For example, multiple small packets can share a single copy of common Ethernet/IP/UDP headers to reduce the percentage of network bandwidth spent on transmitting headers. In the past, packet aggregation and disaggregation were done by a server CPU or a switch CPU, resulting in low throughputs. In this paper, we design and implement packet aggregation and disaggregation functions in the packet processing pipelines of P4 switches. Our novel designs allow packets with various sizes of payload to be aggregated and disaggregated purely in the data plane of a P4 switch. Experimental results show that the achieved throughputs of our aggregation and disaggregation methods can reach 100 Gbps, which is the line rate of the used P4 switch.
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    Long-Term Performance Studies of a LoRaWAN-based PM2.5 Application on Campus
    (2018-01-01)
    Wang, Shie-Yuan
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    Zou, Ji-Jhe
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    Chen, Yo-Ru
    ;
    Hsu, Chun-Chia
    ;
    Cheng, Yu-Hsiang
    Recently, LoRa/LoRaWAN has been proposed as a promising LPWAN technology for Internet-of-Things (IoT) applications. For monitoring the long-term PM2.5 air quality on our campus, starting from February 1 2017, we have set up a LoRaWAN-based PM2.5 air quality monitoring system on our campus. In total, twenty-two PM2.5 sensor devices have been operating at the rooftop of buildings or on the lamp poles since then. Each of these PM2.5 sensor devices uses a LoRaWAN module to send its most recent PM2.5 value to the LoRaWAN gateway every 72 seconds. After being received successfully by the LoRaWAN gateway, the packets carrying these values were stored into a database with their SNR/RSSI information. With the sequence numbers added by our PM2.5 application running on each device, the packets stored in the database provide many important information about the long-term packet loss rate performance of LoRaWAN on campus. In this paper, we process these data to report real long-term performance of LoRaWAN when used on campus.
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    Increasing LoRaWAN Application-Layer Message Delivery Success Rates
    (2018-01-01)
    Wang, Shie-Yuan
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    Chen, Tzu-Yang
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    資訊工程學系
    ;
    Department of Computer Science
    The LoRaWAN network is proposed for IoT applications and has the advantages of long range transmission and low power consumption. However, it suffers from very low data throughputs and long transmission duty cycle delays. In our real on-campus LoRaWAN deployment that has been lasting for one year, we found that even though we placed LoRaWAN end devices (nodes) at a short distance such as less than 700 meters from a LoRaWAN gateway, the packet loss rates at some locations are still too high to be acceptable. In this paper, we propose two approaches to overcome this high packet loss rate problem. We modified the IoT application running on nodes to let a node retransmit its lost data in multiple packets and help transmit its neighboring node's data. Our experimental results show that our approaches can effectively increase the application-layer message delivery success rate of LoRaWAN.
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    Running an IDS Virtual Network Function inside an SDN Bare Metal Commodity Switch
    (2018-01-01)
    Wang, Shie-Yuan
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    Hsieh, Yi-Hsuan
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    資訊工程學系
    ;
    Department of Computer Science
    In this paper, we design, implement, and evaluate the real performance of running multiple Snort IDS (intrusion detection system) VNFs (virtual network function) inside a bare metal commodity switch. In the past, normally people ran Snort on a stand-alone server and configure switches to direct packets to it for inspection. However, more recently there is a trend to implement and run VNF directly inside a switch for immediate and intelligent processing of packets. Our work of running Snort directly inside a bare metal commodity switch as a VNF is the first work of its kind in the world. In this paper, we present real performance results and important findings from this innovative work.
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    High-speed data-plane packet aggregation and disaggregation by P4 switches
    (2019-09-15)
    Wang, Shie-Yuan
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    Wu, Chia-Ming
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    Lin, Yi-Bing
    ;
    Huang, Ching-Chun
    ;
    資訊工程學系
    In this paper, we propose novel approaches that utilize the header manipulations of the P4 (Programming Protocol-Independent Packet Processor) switches to aggregate small IoT packets into a large one, transmit it over a network, and then disaggregate it back to the original small packets, all in the data plane of the hardware P4 switch to provide high throughputs. Packet aggregation and disaggregation provide many important benefits and have been proposed and performed in the past. However, most existing approaches perform packet aggregation and disaggregation in the control plane either by the switch CPU or by the server CPU, resulting in low throughputs. Our work is the first work that designs and implements packet aggregation and disaggregation purely in the pipelines of the switching ASIC. In this paper, we present the design and implementation of our approaches, their measured throughputs, and the insights that we have obtained from this pioneering work.