• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.45-53
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• 2003

Traffic specification plays a crucial role in the resource reservation for video services over the packet-switching networks. The current development of QoS-guaranteed service still leaves a wide space for the selection of traffic specification. We propose a new method to estimate the traffic specification of variable-bit-rate (VBR) video for deterministic service. The method is based on the concept of empirical envelope and the delay bound. The solution shows to be simple yet it provides excellent network utilization.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.85-90
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• 2002

Traffic specification plays a crucial role in the resource reservation for video services over the packet-switching networks. The current development of QoS-guaranteed service still leaves a wide space for the selection of traffic specification. We propose a new method to estimate the traffic specification of variable-bit-rate (VBR) video for deterministic service. The method is based on the concept of empirical envelope and the delay bound. The solution shows to be simple yet it provides excellent network utilization.

• Electronics and Telecommunications Trends
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• v.34 no.2
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• pp.92-100
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• 2019

Vast amounts of different service-specific requirements and vertical network slicing in a 5G network increase the complexity, cost of the network management and resource operations for carriers. To solve this problem, 3GPP is working on the standardization of NWDAF to support the automation of the 5G network by utilizing artificial intelligence technologies based on Big Data to improve the efficiency of network management and resource operation. In addition, the ETSI ZSM Industry Specification Group is developing technical standards for the automation of end-to-end network management and service delivery. This document provides an overall survey of the latest standardization issues of the NWDAF in 3GPP and ETSI ZSM for 5G network automation and intelligence.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.208-211
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• 2003

기존 IEEE 802.11 MAC (1)에서는 Fairness를 보장하며 Resource를 제공하는 것을 목표로 동일한 DIFS, Back-off 알고리즘, Source가 같은 경우 동일한 Frame size등을 사용하는 Specification을 작성하여 구현한다. 최근 Home Network과 같은 특수한 Ad-Hoc 환경에서의 이런 Fairness Resource Usage가 오히려 기대 성능을 떨어뜨리는 결과를 가져오고 있다. 이에 802.11 MAC에서 Backward Compatibility를 유지하면서 Prioritized DIFS/Backoff/Frame를 통해 차등화된 서비스를 제공하는 메커니즘을 제안하고자 하는 것이 본 논문의 목표이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.441-450
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• 2007

In this paper, it is proposed the link performance analysis results using SNRAT(Satellite Network Resource Allocation & Analysis Tool) and verified the anticipated results by satellite communication network simulator. A communication satellite cannot be corrected or fixed for the error in orbit operation after launching unlike the ground operation equipment and has a restricted operation life. So, it is important to make possible to use satellite communications in the proper time. It is expected the link BER(Bit Error Rate), throughput and AJ(Anti-Jamming) performance using SNRAT tool before launching. And it is verified the performance of the repeaters and ground equipment specification using the satellite network simulator and is extracted the optimum operational scenarios through the tests of various network operational plans.

• ETRI Journal
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• v.37 no.6
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• pp.1242-1250
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• 2015

It is very important to provide a parameterized quality of service (QoS) using traffic specification (TSPEC), such as mean data rate, maximum burst size, and peak data rate, when packets from the application layer need to be transmitted with guaranteed services in a high-rate wireless personal area network (HR-WPAN). As medium resources are limited, the optimal medium time required for each device needs to be estimated to share the resources efficiently among devices. This paper proposes a variable-service interval-based resource allocation algorithm to efficiently make a reservation of medium resources based on a parameterized QoS. In other words, the proposed algorithm calculates the number of medium access slots (MASs) based on TSPEC, local resources, and local conditions and determines suitable locations for the MASs within a superframe to accommodate more devices. The simulation results show that the proposed algorithm can accommodate more devices and has greater than 10% resource allocation efficiency in an HR-WPAN compared to existing schemes.

• Journal of Communications and Networks
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• v.8 no.1
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• pp.106-115
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• 2006

The current trend toward the utilization of the Internet as a common means for the offer of heterogeneous services imposes to address the issues related to end-to-end service assurance in the inter-domain scenario. In this paper, we first present an architecture for service management in networks based on service level specifications (SLS). The architecture is designed to be independent both of the specific network technology adopted and of the high level service semantics. Then, we focus on a specific functionality of the proposed architecture: Resource allocation in the multi-domain scenario. A distributed admission control algorithm is introduced, its complexity is evaluated and a comparison with related solutions is provided.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.546-552
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• 2010

As the demands for the safety and convenience applications of the vehicles increase, the data load for the In-vehicle Network has increased significantly. As a result, a deterministic and fault-tolerant communication system is required to implement the safety critical applications such as X-by-wire systems. FlexRay communication system is a new standard of network communication system which provides the high speed serial communication, time triggered bus and fault tolerant communication between electronic devices. In addition to time-triggered communication, as providing of the event-triggered communication such as CAN, FlexRay protocol is able to manage the restricted communication resource more effectively. This paper presents the development of FlexRay driver which will be applied to the future ECU's communication system. To develop the FlexRay driver, the FlexRay requirement specification and FlexRay specification is analyzed. The developed FlexRay driver is implemented by using MPC5567 microprocessor of the Freescale semiconductor. To verify the developed FlexRay driver, the waveform of the FlexRay driver was measured and compared with the CAN communication system. As a result, the bus load is reduced about 13% compared with the CAN communication system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.1
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• pp.83-104
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• 2011

Mobile grid is a combination of grid computing and mobile computing to build grid systems in a wireless mobile environment. The development of network technology is assisting in realizing mobile grid. Mobile grid based on established grid infrastructures needs effective resource management and reliable job scheduling because mobile grid utilizes not only static grid resources but also dynamic grid resources with mobility. However, mobile devices are considered as unavailable resources in traditional grids. Mobile resources should be integrated into existing grid sites. Therefore, this paper presents a mobile grid middleware interconnecting existing grid infrastructures with mobile resources and a mobile service agent installed on the mobile resources. This paper also proposes a mobile resource reliability-based job scheduling model in order to overcome the unreliability of wireless mobile devices and guarantee stable and reliable job processing. In the proposed job scheduling model, the mobile service agent calculates the mobile resource reliability of each resource by using diverse reliability metrics and predicts it. The mobile grid middleware allocated jobs to mobile resources by predicted mobile resource reliability. We implemented a simulation model that simplifies various functions of the proposed job scheduling model by using the DEVS (Discrete Event System Specification) which is the formalism for modeling and analyzing a general system. We also conducted diverse experiments for performance evaluation. Experimental results demonstrate that the proposed model can assist in improving the performance of mobile grid in comparison with existing job scheduling models.

• Convergence Security Journal
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• v.12 no.3
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• pp.75-83
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• 2012

Recent science technology research network moves to establish logical private network among specific research groups such as high energy physics and climate, requiring to implement private network by group for each purpose. Up to now, national research networks such as KREONET service high capacity logical private networks. Therefore standardized configuration and management scheme is essential for the deployment of logical private network. In this study, we propose the core service element and protocols for the logical networks over Layer 2 networks. We also propose system architecture that make monitoring and management easier. After that we design and implement monitoring map for logical network based on scheme. For this purpose, we also propose the description system for logical research network to provide data such as operation information, formation information, performance information and failure information of network infrastructure resource.