Browsing by Author "Lin, Phone"

Now showing 1 - 10 of 10

A Connection-Driven Mechanism for Energy Saving of Small-Cell Networks
(2016)
Yeh, En-Hau
;
Lin, Phone
;
Lin, Yi-Bing
;
Lee, Chia-Peng
;
資訊工程學系
The small cell technology is proposed to provide wireless transmission services in the indoor environment and offload the traffic from a macro cell. Because of the small coverage of a small cell, there are usually a large number of small cells deployed in the mobile network, and it is likely that there are no User Equipments (UEs) in a small cell. A small cell may be idle most of the time and waste energy. In this paper, we propose a Connection-Driven (CD) mechanism for energy saving of small cells, where a small cell in the sleep mode is woken up when there are UEs (that have ongoing dedicated bearers) within its service area. We propose an analytical model and simulation experiments to investigate the performance of the CD mechanism.
A File Repair Scheme for UMTS MBMS Service
(2008-11-01)
Lai, Yen-Cheng
;
Lin, Phone
;
Lin, Yi-Bing
;
Chang, Lu-Tsung
;
資訊工程學系
The 3rd Generation Partnership Project (3GPP) Technical Specification 23.246 proposed the Multimedia Broadcast Multicast Service (MBMS) that efficiently multicasts multimedia content. During NOMS content transmission, data may be lost. Three file repair schemes were proposed to retransmit the corrupted MBMS data. However, these schemes may introduce extra data traffic or signaling overheads. This paper proposes the Reuse Bearer Service (RBS) file repair scheme to resolve this issue. We analyze the four file repair schemes by analytical models and simulation experiments. This paper shows that the proposed RBS scheme may significantly outperform the previously proposed schemes.
IoTtalk: A Management Platform for Reconfigurable Sensor Devices
(2017-10-01)
Lin, Yi-Bing
;
Lin, Yun-Wei
;
Huang, Chun-Ming
;
Chih, Chang-Yen
;
Lin, Phone
IoTtalk is a platform for Internet of Things (IoT) device interaction, which nicely integrates a reconfigurable multi-sensor device called MorSensor with the proposed IoT management platform in the network domain. The sensors can be dynamically plugged in/out of a MorSensor device without being turned off, and IoTtalk automatically generates/reuses the application software for these sensors. We propose a dynamic ranging concept that automatically specifies the value range of a sensor so that it can send "meaningful" data to any connected output IoT device. Therefore, a MorSensor device can "talk" to other IoT devices, such as a light bulb or an electric fan. We also show that IoTtalk is a simple yet almost free solution for automatic sensor calibration. Finally, we illustrate that IoTtalk is a powerful tool for developing interactive science experiments.
Modeling Mobile Ticket Dispenser System With Impatient Clerk
(2016-12)
Liu, Gi-Ren
;
Lin, Phone
;
Lin, Yi-Bing
;
資訊工程學系
;
Department of Computer Science
The mobile ticket dispenser system (MTDS) allows customers to remotely draw tickets for service orders anywhere through a mobile handset. In our previous work, the MTDS was applied to a restaurant scenario in which both clerks and customers are patient, i.e., once a mobile ticketing (MT) customer remotely draws the ticket, his request can be served by the clerk when the clerk is available, regardless of when the customer arrives at the restaurant. In this paper, the MTDS is applied to a post office scenario in which the customers are patient, but the clerk is impatient since the original ticket drawn by theMT customer may be invalid if he/she does not arrive at the post office before his/her turn. In this case, the behavior of the MT customer is the same as the so-called in-person ticketing customer who needs to draw a ticket in person when he/she arrives at the service counter. We propose an analytical model to derive the probability that an MT customer misses his/her turn when he/she arrives at the post office. A discrete-event simulation model is developed to investigate the performance of the predicted time adjustment mechanism for the MTDS. We also use real data collected at a post office to observe the queuing behavior. Our study provides guidelines for arranging the time for an MT customer to arrive at the MTDS server.
Optimal Threshold Policy for In-Home Smart Grid with Renewable Generation Integration
(2015-04-01)
Liu, Gi-Ren
;
Lin, Phone
;
Fang, Yuguang
;
Lin, Yi-Bing
;
資訊工程學系
In-home Smart Grid (SG), the integration of Renewable Power Systems (RPSs) with Conventional Power Systems (CPSs), calls for cost-effective management for the electricity usages of end users\' household appliances. In this paper, by taking the charging process of RPSs and multiple types of household appliances in to consideration, we have developed analytical models to characterize the electricity cost in the in-home smart grid. Based on these models, we formulate the electricity cost minimization problem as a finite-horizon continuous-time Markov decision process (CTMDP), from which we obtain a threshold policy to minimize the cost. Numerical results show that the threshold policy can manage the electricity usage very effectively.
Reducing Signaling Overhead for Femtocell/Macrocell Networks
(2013-08-01)
Fu, Huai-Lei
;
Lin, Phone
;
Lin, Yi-Bing
;
資訊工程學系
;
Department of Computer Science
Femtocell technology has been proposed to offload user data traffic from the macrocell to the femtocell and extend the limited coverage of the macrocell in mobile communications networks. In existing commercial femtocell/macrocell networks, a widely accepted solution to configure the location areas (LAs) is to partition the femtocells overlapped with a macrocell into small groups and to assign each group with a unique LA ID different from that of the macrocell. Such configuration can reduce the paging cost in the mobility management, but increases registration signaling overhead due to discontinuous coverage of femtocells. To reduce signaling overhead in the femtocell/macrocell network, we propose a delay registration (DR) algorithm that postpones the registration until the delay timer expires when the mobile station (MS) moves into the overlapped femtocell. Analytical models and simulation experiments are proposed to investigate the performance of the DR algorithm. Our analytical models are generally enough to accommodate various MS mobility behaviors. Our study can provide guidelines for the operators to set up a delay timer to reduce signaling overhead while sustaining the traffic offloading capability of the femtocell.
SES: A Novel Yet Simple Energy Saving Scheme for Small Cells
(2017-09-01)
Lin, Yi-Bing
;
Wang, Li-Chang
;
Lin, Phone
;
資訊工程學系
;
Department of Computer Science
Energy saving of small cells is an important issue for a mobile network deployed with a large number of small cells. These small cells are typically overlapped with macro cells. When the call traffic is light, a small cell enters the dormant mode to save energy. Therefore, its call traffic is directed to the overlapped macro cell. When the traffic load of the macro cell becomes heavy, the macro cell wakes up the dormant small cells to share the traffic load. It is a nontrivial task to wake up the "right" dormant cells. This paper proposes simple energy saving (SES), which is a simple yet novel scheme, to accurately wake up the dormant small cells. In a low-traffic environment, our scheme enables the small cells to quickly enter the dormant mode. When the macro cell is heavily loaded, it wakes up the dormant small cells to share its traffic load. Specifically, with 90% of energy saving in our scheme, a dormant small cell can be detected and reported to the macro cell in 1.3716 s. When the macro cell conducts the wakeup mechanism, with a probability of 0.9, more than 75% of the dormant small cells are not affected and can stay in the dormant mode. We also show that energy saving of the SES scheme is more effective when the macro cell covers a larger number of small cells.
Special issue on next generation wireless technologies
(2007-02-01)
Shen, Xuemin (Sherman)
;
Lin, Phone
;
Lin, Yi-Bing
;
Hou, Y. Thomas
;
資訊科學與工程研究所
Survey on Networking for Internet of Vehicles
(2013-12-01)
Cheng, Bo-Chao
;
Chou, Chun-Ting
;
Chang, Chia-Hsuan
;
Lo, Kuo-Hsuan
;
Lin, Phone
With continuous advancement in wireless communications, transportation vehicles, such as automobiles or even high-speed trains, will essentially become a unique moving-node in the entire global communications network. Many new telematics services could be created through these emerging networking technologies. The Internet of Vehicle (IoV) network refers to networking technologies that could support highly economical and effective communication channels for the interactions between vehicles (including automobiles and high-speed trains). Examples of potential services and applications on the IoV network include safety and real-time operational status for vehicles, passenger entertainment, and end-to-end secure communications for vehicles. In this paper, we provide an overview of the potential technical challenges for the IoV network. To be more specific, we discuss the communications protocols (including wireless access and routing) and security (including the secured and privacy-preserving communications) for the IoV network.
Time-division-based cyclic scheduling for UMTS high-speed downlink shared-channels
(2007-07-01)
Gan, Chai-Hien
;
Perng, Nei-Chiung
;
Lin, Phone
;
Kuo, Tei-Wei
;
資訊工程學系
Third Generation Partnership Project working group proposes the high-speed downlink packet access to speed up downlink transmission for the universal mobile telecommunication system, where the time-division-based high-speed downlink shared-channel (HS-DSCH) approach is adopted. Our previous work proposed the shared-channel assignment and scheduling (SCAS) scheme to efficiently schedule the DSCH to serve different connections, which guarantees the requested transmission rate for each connection. However, limitations exist in the SCAS scheme: 1) the requested transmission rates of connections must be two's power numbers of the basic transmission rate and 2) all served connections should be rescheduled while a new request is. granted, which introduces extra rescheduling overhead to the system. This paper proposes the elastic shared-channel assignment and scheduling (eSCAS) scheme to overcome these limitations. We formally prove the correctness of the eSCAS scheme. An analytical model and simulation experiments are conducted to compare the performance for eSCAS and SCAS. Our study shows that eSCAS can significantly improve the acceptance rate for new connections without increasing the rescheduling overhead.