Browsing by Author "Ho, Ping-Fan"

Now showing 1 - 11 of 11

A Local Mobility Management Entity (MME) for Stationary Devices in virtual Evolved Packet Core (vEPC)
(2018-01-01)
Qiu, Bo-Jun
;
Li, Jia-Ru
;
Hsueh, Yu-Sen
;
Lin, You-Min
;
Chen, Jyh-Cheng
In the future, there will be many devices in 5G networks, and these devices will cause a great number of control messages. The core network should handle these control messages locally to maintain the quality of other services. Furthermore, the local MME should turn off the location update flows in the initial attach procedure to reduce the number of control messages. We implement an MME, which can turn off the location update flows, and then compare the performance.
A New SDN-Based Architecture and Authentication Method for Taiwan High-Speed Rail
(2017-01-01)
Lin, Yi-Hao
;
Ho, Ping-Fan
;
Chen, Jyh-Cheng
;
Yang, Jen-Shun
;
Chang, Hsien-Wen
The urgency of improving user experience has reached a critical point in the high-speed rail environment. However, there is little literature considering authentication failure problems in the high-speed rail environment. In this paper, we present a new authentication architecture for Taiwan High-Speed Rail (THSR). This new authentication architecture applies Software-Defined Network (SDN)-based principles to an outbound LTE gateway platform. We propose a post-authentication method suitable for the high-speed mobile environment, such as THSR. The proposed architecture and method can improve user experience regarding successful authentication ratio, authentication latency, and network access latency compared to the existing system.
A New SDN-Based Authentication Architecture and Method for Taiwan High Speed Rail
(2016)
Lin, Yi-Hao
;
Ho, Ping-Fan
;
Chen, Jyh-Cheng
;
資訊工程學系
;
Department of Computer Science
In this paper, we present a new authentication architecture for Taiwan High Speed Rail (THSR). The new authentication architecture applies multiple outbound LTE gateways. We also propose an SDN-based authentication method using post-authentication that is suitable for high-speed environment, including THSR. The proposed architecture and method can reduce network congestion and shorten the authentication latency compared to the existing system.
Design, Implementation and Experiments of a Wi-Fi D2D-based Automatic Vehicle Location (AVL) System
(2016)
Ho, Ping-Fan
;
Chen, Jyh-Cheng
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose WiAVL, a novel Automatic Vehicle Location (AVL) system based on Wi-Fi Device-to-Device (D2D) communications. WiAVL can monitor, record and notify the location of public transportation vehicles with low communication cost by leveraging Wi-Fi Beacons. In addition, we address the interference problem. A proof-of-concept prototype is implemented. Experimental results are also presented to demonstrate the feasibility and performance results of the proposed system.
Empirical Experience and Experimental Evaluation of Open5GCore over Hypervisor and Container
(2018-01-01)
Chang, Hung-Cheng
;
Qiu, Bo-Jun
;
Chen, Jyh-Cheng
;
Tan, Tze-Jie
;
Ho, Ping-Fan
One of the most important technologies for future 5G networks is to utilize Network Function Virtualization (NFV) to virtualize the network components. NFV provides flexibility, short time to market, and low cost solution to build network services, which are important features of 5G networks. Although the idea of virtualization is just being applied to cellular networks, it has been used in the community of cloud computing. There are two main virtualization techniques, hypervisor and container. In this paper, we present our practical experience of virtualizing Open5GCore, a commercial product of SDN-enabled Evolved Packet Core (EPC), over hypervisor and container. In addition to describing how to virtualize Open5GCore, we also present the experimental performance evaluation of the systems. Finally, some important lessons learned are provided.
Poster: Service Level Virtualization (SLV) A Preliminary Implementation of 3GPP Service Based Architecture (SBA)
(2018-01-01)
Qiu, Bo-Jun
;
Hsueh, Yu-Sen
;
Chen, Jyh-Cheng
;
Li, Jia-Ru
;
Lin, You-Min
For future 5G core networks, Service Based Architecture (SBA) has been proposed in 3GPP Release 15. To realize the idea of SBA, we propose Service Level Virtualization (SLV) in which each network entity is decomposed into different service blocks to provide respective services. In addition, each service block can be virtualized independently into different virtual machine. Thus, SLV can increase the flexibility of the core network.
Sensing Phone Use of Motorcycle Drivers
(2014)
Chen, Jyh-Cheng
;
Wu, Chun-Feng
;
Chung, Wei-Ho
;
Ho, Ping-Fan
;
資訊工程學系
Due to safety reasons, using mobile phones while driving is prohibited in many countries. Research has also shown that motorcycle riders are 20 times more likely to be killed in a crash than vehicle occupants. Therefore, it is more critical to restrict the use of mobile phones of motorcycle drivers than car drivers. There are some studies that focus on how to distinguish phone use between a driver and other passengers in a car. The techniques used for cars, however, are not always applicable to motorcycles. In this paper, we propose a way to detect phone use of motorcycle drivers. By using two low-cost Bluetooth emitters, mobile phones of the driver and the passenger can measure the signal strengths and decide their locations. We have conducted extensive experiments with various smartphones. The results show that on average we can achieve 9 6 % accuracy.
Signal Measurement and Prediction of WiMAX Basestations on Taiwan High Speed Rail
(2016)
Wu, Dan-Chen
;
Ho, Ping-Fan
;
Chen, Jyh-Cheng
;
Yang, Jen-Shun
;
Chang, Hsien-Wen
When communicating at high-speed environment such as high-speed rail, the signals may encounter fast fading due to the terrain changes. In such communication environment, signal prediction can help improve the system throughput and reduce packet loss. In this paper, we propose a prediction mechanism called Window Weight Moving Average (WWMA) to predict the signal strength. We also analyze the real WiMAX signal data collected from Taiwan High Speed Rail (THSR). The analytical results will facilitate the migration from WiMAX to LTE.
Using Barometer on Smartphones to Improve GPS Navigation Altitude Accuracy
(2018-01-01)
Ho, Ping-Fan
;
Hsu, Chia-Che
;
Chen, Jyh-Cheng
;
Zhang, Tao
;
資訊工程學系
Today's GPS navigators have difficulty determining altitude such as whether a car is under or on an overpass. In this paper, we show how to use the barometers, which come with off-the-shelf smartphones, to improve vertical positioning accuracy. We will present performance testing results from different real road scenarios to show the feasibility of the proposed method.
Vehicular Signal Transmission Using Power Line Communications
(2012)
Chen, Yen-Chang
;
Tsai, Shang-Ho
;
Yang, Kai-Jiun
;
Ho, Ping-Fan
;
Tseng, Kuo-Feng
We propose a power line communication (PLC) system for transmitting control signals in vehicle through internal power lines, such that the internal wires can be reduced and the vehicles can be lighter. The signals from different devices are multiplexed and modulated to the power lines by the transmitter. In the receiver, first the noise within power lines are filtered. Afterwards the multiplexed signals are selectively extracted by specific codes which are minimally correlated. Finally the control signals are restored from the error-control coded bits which make the information more robust. The maximum data rate of the chip is 50 kbps, and the die area is 3.74 mm(2) using a TSMC 0.18 mu m standard cell library with power consumption 22.49 mW.
WiSafe: Wi-Fi Pedestrian Collision Avoidance System
(2017-06-01)
Ho, Ping-Fan
;
Chen, Jyh-Cheng
;
資訊工程學系
;
Department of Computer Science
In this paper, we present a novel Wi-Fi-based pedestrian collision avoidance (PCA) system: WiSafe. Compared to vision-based and radar-based PCA systems, WiSafe has a key advantage of Non-Line-of-Sight (NLOS). WiSafe can assist drivers in discovering pedestrians in NLOS and blind spots, where the views of drivers are blocked by buildings, vehicles, or other obstacles. In particular, it is very useful when driving in poor visibility conditions such as at night, in heavy rain, or thick fog. WiSafe can save split seconds, which can potentially save lives. Instead of using wireless access in vehicular environments/dedicated short-range communications to protect pedestrians, WiSafe provides a simple, effective, and low-cost solution. Without changing Wi-Fi standards, WiSafe is compatible with 802.11a/b/g/n and can be implemented by apps on smartphones or wearable devices. The complete analysis, implementation, and experiments are presented in this paper. The results show that WiSafe can achieve and even exceed the PCA requirements.