• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.91-91
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• 2004

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.643-646
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• 2005

In this paper, we present a service model which serves multimedia contents to end consumer(End-user) that have various mobile communication terminals under a communication & broadcasting converged environment that broadcasting and communication networks are linked. A main feature of this service model is that it has a distribution structure that deliver to end consumer via adaptation of content from production of contents offering End to End (E2E) media QoS and personalized contents consumption. The proposed service model may be used as a reference model for distribution of multimedia content in communication & broadcasting converged environment in the future.

• Smart Media Journal
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• v.8 no.2
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• pp.29-38
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• 2019

With the advancement of information and communication technology, tactical networks are continuously being converted to All-IP future tactical networks that integrate all application services based on Internet protocol. Futuristic tactical mesh network is built with tactical WAN (wide area network) nodes that are inter-connected by a mesh structure. In order to guarantee QoS (quality of service) of application services, tactical service mesh (TSM) is suggested as an intermediate layer between infrastructure and application layers for futuristic tactical mesh network. The tactical service mesh requires dynamic QoS monitoring and control for intelligent QoS coordination. However, legacy networking nodes used for existing tactical networks are difficult to support these functionality due to inflexible monitoring support. In order to resolve such matter, we propose a tactical mesh WAN node as a hardware/software co-designed networking node in this paper. The tactical mesh WAN node is conceptually designed to have multi-access networking interfaces and virtualized networking switches by leveraging the DANOS whitebox server/switch. In addition, we explain how to apply eBPF-based traffic monitoring to the tactical mesh WAN node and verify the traffic monitoring feasibility for supporting QoS coordination of tactical-mesh traffic.

• Journal of Korean Society for Quality Management
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• v.35 no.3
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• pp.37-46
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• 2007

Our society is increasingly dependent on the Internet, and this trend will be accelerating in the ear of All-IP convergence. As the core infrastructure of the All-IP convergence, the next generation Internet should enable end-to-end Quality of Service(e2e QoS). For that purpose, major international standardization institutes such as ITU(International Telecommunication Union) and IETF(Internet Engineering Task Force) are building the concept and architecture of the Next Generation Network(NGN). However, these institutes focus only on technical issues, and leave many business/policy-oriented challenges unresolved. For example, the standards raised by ITU assume that the entire service delivery process for e2e QoS services is perfectly working. But required is a standardized business interface and process for seamless inter-operations across many stakeholders including ISPs(Internet Service Providers), CPs(Content Providers), so on. On the other hand, TMF(TeleManagement Forum) and QuEST(Quality Excellence for Suppliers of Telecommunication) Forum, global consortiums of telecom operators and vendors, present sets of interface rules and process which playa crucial role as de facto standards: for example, NGOSS/eTOM and TL9000 authorization system. However, these standards focus on telephone services, and provide little principle for the next generation Internet. Our study seeks a way to combine these two strains for a successful implementation of NGN. In particular, we find a missing link in the NGN architecture and the elements that could be complemented with the help of NGOSS/eTOM and TL9000. Finally, presented is a strategic direction that our standardization policy should purse in order to reinforce our global leadership for the next generation Internet.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.611-614
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• 2007

The IEEE 802.11 Task Group E has worked to enhance the legacy 802.11 MAC to expand support for applications with QoS requirements. EDCF(Enhanced Distributed Coordination Function) of IEEE 802.11e is enhanced from DCF(Distributed Coordination Function) of 802.11 and It has differential AC(Access Category). In this paper, we change parameters(AIFS, CWmax) and make an analysis of network performance. We use NS-2 to verify change of network performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.145-152
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• 2009

IEEE 802.16e standard, a kind of WMAN standard, was established to support data services with cheaper cost to mobile users than traditional mobile communications system and wireless LAN system can do. In this paper, we propose an uplink QoS packet-scheduler for VoIP service which can be installed in IEEE 802.16 system and evaluate its performance with NS-2 network simulator. The proposed QoS packet-scheduler consists of three procedures: determining scheduler interval, determining the amount of resource assignment, and deciding which mobile station the base station should serve first among multiple mobile stations. According to numerical results, the proposed QoS packet-scheduler can provide more increased system capacity by 220% than UGS service scheme does and by 25 % than ertPS service scheme does.

• Information and Communications Magazine
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• v.22 no.12
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• pp.120-133
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• 2005

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.3
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• pp.72-82
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• 2003

인터넷의 사용이 폭발적으로 증가함으로 인해 다양한 서비스들의 욕구가 있고 그 중에서도 VoIP가 대표적인 예이다. ITU-T의 Study Group12에서 QoS (Quality of Service)에 관한 연구를 진행하고 있다. 그 중에서도 품질평가 방법에서 전송계획을 위한 G,107의 E-model을 PSTN에서 IP네트워크로 적용하는 연구를 진행하고 있다. VoIP의 QoS문제점을 분석하고 E-model에서 개선되어야 할 파라미터들을 확인하고, 이를 위한 ITU-T의 개선동향을 살펴봄으로써 앞으로의 E-model이 나아가야 할 방향에 대해서 기술하였다.

• IE interfaces
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• v.22 no.1
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• pp.95-103
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• 2009

During the past few years, design of experiments (DOE) has been gaining acceptance in the telecommunications research community as a mean for designing and analyzing experiments economically and efficiently. In addition, the need for introducing a systematic robust design methodology (i.e., one of the most popular DOE methodologies) to network simulations has been increasing. In this paper, we present an architecture of voice over IP (VoIP) application and the E-Model for calculating the perceived quality of service (QoS). Then, we apply the Taguchi robust design methodology to optimize the perceived QoS of VoIP application, and describe the detailed step-by-step procedures. We have used ns-2 simulator to collect experimental data in which the SN ratio, a robustness measure, is analyzed to determine an optimal design condition. The analysis shows that "initial delay time in playout buffer" is a major control factor for ensuring robust behaviors of the perceived QoS of VoIP. Finally, we verify the proposed optimal design condition using a confirmation experiment.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.121-126
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• 2001

1. TP 상용화 시 준비사항 ◈ E&M card로 연동하기위한 PBX의 보유 여부 확인 ◈ TP의 PBX타입이 E＆M을 지원하는지의 여부 확인. ◈ TP의 PBX타입이 E&M을 지원하지않는다면 E&M card의 설치여부결정. ◈ 최소 라우터 사양 CISCO 1750 (E＆M포트 2개 지원) 2. 전화번호체계에 대한 정책 ◈ 기존 일반 전화 활용 ㆍ기존 엑세스 코드에서 VoIP망에 대한 엑세스 코드만 정의하면 됨. ㆍ전화번호를 따로 관리할 필요가 없음. ◈ 새로운 전화번호 활용 ㆍKNX 차원의 전체적인 번호체계를 별도로 수립 CEPO나 KNXO에서Gatekeeper적용 3. QoS ◈ 사용자의 DATA와 Voice에 대한 중요도 조사 후 적용 범위 결정(중략)