• 방송공학회논문지
• /
• 제8권1호
• /
• pp.45-53
• /
• 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.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 2002년도 정기총회 및 학술대회
• /
• pp.85-90
• /
• 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.

• 전자통신동향분석
• /
• 제34권2호
• /
• pp.92-100
• /
• 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.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
• /
• pp.208-211
• /
• 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.

• 한국통신학회논문지
• /
• 제32권5A호
• /
• pp.441-450
• /
• 2007

본 논문에서는 위성망 자원할당 및 분석 툴(SNRAT : Satellite Network Resource Allocation & Analysis Tool)을 활용하여 위성통신체계에 대한 링크성능 분석결과를 제시하였으며, 모의위성망을 구성하여 성능분석 툴로 예측한 링크 성능을 검증하였다. 통신위성은 지상장비와 달리 정지궤도에 발사하여 궤도 내 운용을 시작하면, 더 이상 성능의 수정이나 수리가 불가능하고, 운용 가능한 수명이 제한되어 있기 때문에 적기에 배치하여 운용하는 것이 매우 중요하다. 따라서, 위성 발사 전 위성망 자원할당 및 분석 툴을 이용하여 통신품질, 지원용량 및 항재밍 성능 등을 예측하고, 모의위성망을 구축하여 지상단말과 망제어기와 같은 지상장비 및 중계기 규격의 적합성을 증명하였으며, 여러 망 운용 시나리오에 대한 시험을 통해 최적의 운용방안을 도출하였다.

• ETRI Journal
• /
• 제37권6호
• /
• pp.1242-1250
• /
• 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
• /
• 제8권1호
• /
• pp.106-115
• /
• 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.

• 제어로봇시스템학회논문지
• /
• 제16권6호
• /
• pp.546-552
• /
• 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)
• /
• 제5권1호
• /
• pp.83-104
• /
• 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.

• 융합보안논문지
• /
• 제12권3호
• /
• pp.75-83
• /
• 2012

높은 네트워크 대역폭과 고품질을 요구하는 고에너지 물리, 기상 기후 등과 같은 특정 연구 그룹간의 논리 네트워크를 구축하여, 일종의 특정 그룹별 사설 네트워크 구축과 운용이 최근 많이 요구되고 있다. 지금까지 국내에서는 KREONET과 같은 국가연구망이 중심이 되어 이러한 대용량 사설 네트워크 서비스를 제공하고 있으나 이러한 사설 네트워크에 대한 체계적이고 표준화된 구축 및 관리 방법이 없어 이에 대한 체계적인 연구가 시급한 실정이다. 이를 위해 본 논문은 L2 기반에서 다양한 그룹별 논리 네트워크를 구성하는 핵심 서비스 요소와 표준 프로토콜을 제시하고, 구성된 논리 네트워크 정보를 관리 모니터링 할 수 있는 시스템 구조를 제시하였다. 또한 본 논문은 네트워크 인프라 자원과 관련된 망의 운영정보, 구성정보, 성능정보, 장애정보 등에 대한 정보를 통합적으로 관리할 수 있는 표준화된 명세시스템 구조를 제시하였다.