• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.18-26
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• 2003

In this paper, we design and implement a QoS control function in the SIP-based VoIP system. As a network infrastructure for VoIP service, we select the Intserv over Diffserv architecture where the network resources are managed by a call admission control mechanism. The SIP protocol extended to support QoS signaling procedure is modulized to operate independently with the infrastructure. The performance of the QoS-enabled VoIP system is verified by experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.884-887
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• 2003

The standardization of QoS is recently becoming a major issue in VoIP market. This research is to look into the trend of the world and specification about QoS standadization, and present the needs for domestic VoIP QoS standardization.

• Convergence Security Journal
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• v.15 no.2
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• pp.57-62
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• 2015

IP QoS is not required to overcome the limitations of the existing Best Effort Service to connect to the explosion of the Internet traffic revenue. To IP QoS requirements of next-generation communication network, Metric Sizing Methodology is very important. However, IP networks have been developed with a focus gender flexibility and scalability than the QoS. Therefore, it is necessary to secure the quality measures for different existing IP technology to apply QoS in IP networks. When establishing the connection quality and transmission quality, based on the IP QoS(Quality of Service) objective data quality metrics can be obtained by analyzing the communication quality hindrance. Understanding the communication quality level may evaluate quality sensitive area and quality hindrance. Establish effective quality metrics can be expected to promote effective and customer satisfaction through improved quality, improved call quality for this issue.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.415-424
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• 2008

In this paper, we compare the QoS performance enhancement schemes according to the network architecture of mobile WiMAX system in order to improve the end-to-end QoS performance and propose QoS parameter mapping method and IP packet scheduling algorithm. To evaluate the end-to-end QoS performance, we implemented an end-to-end simulator of mobile WiMAX system using OPNET. Simulation results show that the proposed QoS parameter mapping scheme reduces the average delay of VoIP packet and improves uplink resource efficiency. And also, when the proposed IP packet scheduling algorithm is applied to the system, the end-to-end packet transmission delay of VoIP service can be reduced by 44-67 percent compared to FIFO and WRR scheduler.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9B
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• pp.834-844
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• 2003

Mobile IP has some performance degrade factors such as triangle routing and packet loss by the hand-off because the original IP was designed for the fixed network. The design goal for the next generation Internet service is to guarantee QoS. So, Mobile IP also should be able to provide the guaranteed QoS with performance enhancement because it is an IP-based mobile Internet service. In this paper, we propose route optimization, smooth hand-off scheme and MIP-LDP(Mobile IP-Label Distribution Protocol) on Mobile IP-over-MPLS framework to enhance the performance of the previously researched Mobile IP-over-MPLS schemes. The proposed framework enhanced long routing path problem and packet loss problem by the hand-off.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.71-84
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• 2005

A 'VPN over Intemet' has the benefit of being cost-effective and flexible. However, it has difficulties providing sufficient QoS and adequate transmission capacity for high bandwidth service. Given the increasing demand for high bandwidth Internet and QoS assurances in a 'VPN over Internet', IP/GMPLS based on a control plane combined with a high bandwidth, DWDM optical network is seen as a very favorable anroach for realizing the future 'OVPN over IP/GMPLS over DWDM'. Within this architecture, providing QoS guaranteed multimedia services with a differentiated QoS guaranteed protocol framework with QoS recovery is one of the key issues to implement. Therefore, in this paper, we suggest the entire interoperability procedure of control protocols based on differentiated optical QoS service (DOQOS) classes for providing end-to-end QoS in an 'OVPN over IP/GMPLS over DWDM' architecture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2B
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• pp.192-202
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• 2004

In this paper we have proposed policy-based network management system architecture for Internet QoS support Mobile IP networks that is divided into four layers(application layer, information management layer, policy control layer, device layer), then we propose an implementation strategy of policy-based network management system to enforce various control and network management operations and a model of policy server using SCOPS(Simple Common Open Policy Service) protocol that is developed in this research. For policy-based mobile IP network management system implementation, we have derived four policy classes(access control, mobile IP operation, QoS control, and network monitoring) and we showed operation procedures for each policy scenarios. Finally we have implemented Internet QoS support policy-based mobile IP network testbed and management system and verified out DiffServ policy enforcement behaviors for a target class service that is arranged a specific bandwidth on network congestion conditions.

• Electronics and Telecommunications Trends
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• v.18 no.3 s.81
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• pp.21-28
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• 2003

인터넷 서비스의 급증으로 QoS에 대한 중요성이 증대되고 있는데, 본 논문에서는 IP 네트워크에서 QoS서비스를 제공하기 위한 방안으로 ATM 전송계층을 이용하는 방법에 대해 기술한다. 여기서는 유럽의 BTI 프로젝터에서 수행한 IntServ 구조와 액세스 네트워크 측면에서 통신 인프라 구축에 필요한 소요자원을 줄이고 새로운 서비스 제공을 용이하게 하는 QoS 기반기술에 대해 기술한다. 특히 실제 BTI의 원격학습 응용을 통해 QoS 제어 성능을 분석하고, IP/ATM 통합망에서의 QoS 제어방안에 대해 고찰한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.653-663
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• 2002

UMTS/GPRS has its own QoS architecture, but additionally needs to support IP-QoS to provide Internet services. This paper describes an IP-QoS provisioning mechanism in the MPLS-based UMTS/GPRS network. We propose a QoS framework that includes the functional architecture of the MPLS-based GPRS networks and the efficient scheduling mechanism based on Diffserv model. The proposed scheduling mechanims is especially focused on the QoS support for real-time services. It also includes a new buffer management scheme that combines the priority queuing and weighted round robin method. The ns-2 simulator has been used to verify the validity of the proposed scheduling method.

• Journal of Digital Contents Society
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• v.12 no.1
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• pp.85-94
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• 2011

QoS(Quality of Service) is defined as "The collective effect of service performance which determines the degree of satisfaction of a user of the service" by ITU-T Rec. E.800. While the use of VoIP(Voice Over Internet Protocol) has been widely implemented, persistent problems with QoS are a very important sue which needs to be solved. This research is finding the assignment of VoIP QoS to deduct how to manage the control system and presenting the QoS control process and framework under NGN(Next Generation Network) environment. The trial framework is the modeling of the QoS measurement metrics, instrument, equipment, method of measurement, the series of cycle & the methodology about analysis of the result of measurement. This research underlines that the vulnerability of the VoIP protocol in relation to its QoS can be guaranteed when the product quality and management are controlled and measured systematically. Especially it's very important time to maintain the research about VoIP QoS measurement and control because the big conversion of new network technology paradigm is now spreading. In addition, when the proposed method is applied, it can reduce an overall delay and can contribute to improved service quality, in relation to signal, voice processing, filtering more effectively.