• Journal of the Korea Society of Computer and Information
• /
• v.4 no.4
• /
• pp.140-147
• /
• 1999

ABR uses the extra network resource more efficiently which uses not the guaranteed service in ATM and supports the best effort which the characteristics of application is bursty and maximum transfer rate is high. Switches for using ABR flow control differentiate EFCI switches (which supply only the congestion state information) from ER switches (which supply fair rate to source). This paper analyses the switches operation technique for efficiently managing ABR traffic in case which the network mixes EFCI switches and ER switches in ATM.

• Journal of Advanced Navigation Technology
• /
• v.10 no.1
• /
• pp.63-69
• /
• 2006

Recently there are increasing needs for Internet and various kinds of contents. These traffics for various contents need more amount of data to provide high-quality information and require various QoS depending on the characteristics of contents. However, current Internet service supports BE (Best Effort) service only, therefore IntServ (Integrated Service) scheme and DiffServ (Differentiated Service) scheme are represented to support QoS in IP layer. Moreover, while wireless Internet is getting popular, MAC(Medium Access Control) is also becoming important. This is due to the fact that wireless access, resource allocation and packet scheduling, which are done in another layers before, are performed in MAC layer in many new wireless systems. This paper describes new scheme that provides QoS taking into account the traffic characteristics over Mobile IPv6 network based on IEEE 802.11e EDCF and evaluates the performance through computer simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.573-577
• /
• 2005

Recently there are increasing needs for Internet and various kinds of contents. These traffics for various contents need more amount of data to provide high-quality information and require various QoS depending on the characteristics of contents. However, current Internet service supports BE (Best Effort) service only, therefore IntServ (Integrated Service) scheme and DiffServ (Differentiated Service) scheme are represented to support QoS in IP layer. Moreover, while wireless Internet is getting popular, MAC(Medium Access Control)is also becoming important. This is due to the fact that wireless access, resource allocation and packet scheduling, which are done in another layers before, are performed in MAC layer in many new wireless systems. This paper describes new scheme that provides QoS taking into account the traffic characteristics over Mobile IPv6 network based on IEEE 802.11e EDCF and evaluates the performance through computer simulation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.6
• /
• pp.1168-1176
• /
• 2003

Internet telephony service is very cheap and very easy to introduce the value-added service than the POTS, but is difficult to the QoS of telephone service. The existing internet typically offers "best effort" services only, which do not make any commitment about delay, packet loss and jitter. This paper compensates the low quality of the speech for packet loss or delay using FEAPT algorithm in Internet phone. In the FEAPT algorithm, the receiver expands the received packet under resonable threshold, and hence compensates the QoS of speech.of speech.

• Journal of IKEEE
• /
• v.13 no.4
• /
• pp.15-21
• /
• 2009

Proxy Mobile IP in IETF is a network-based mobility management scheme to solve the problem of host-based mobility management scheme, Mobile IP. PMIP shows the better performance in the aspect of mobility, but PMIP, as a legacy of Mobile IP based on "best effort service", lacks of consideration of QoS. In this thesis, a novel mobility support scheme is proposed for mobility and QoS support based on PMIP in MPLS networks.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10c
• /
• pp.454-456
• /
• 1999

최선형 서비스(best effort service) 방식의 현재 인터넷은 실시간 응용의 출현과 보다 나은 서비스를 기대하는 사용자들에 의해 많은 변화가 요구되고 있다. 최근 사용자에게 서로 다른 수준의 서비스를 제공하는 차별화 서비스(differentiated service) 모델에 관하여 많은 연구가 진행중이다. 두 가지 우선 순위를 바탕으로 서비스를 제공하는 RIO 모델은 차별화 서비스의 대표적인 모델이지만 네트워크 상황에 따라 적절한 서비스 차별화가 이뤄지지 않는다. 본 논문에서는 이를 개선하여 보다 효과적인 서비스 차별화기 이뤄지도록 하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.433-433
• /
• 2000

In this paper, we propose a development of internet teleoperation method applying QoS model, which has the real time control capability and the time-delay predicting capability, The QoS model gives a constant bandwidth to a specified application and makes the dynamically irregular time-delay to be predictable and fined so that it can have real-time capability.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.11B
• /
• pp.969-978
• /
• 2006

Recently, there has been explosive growth in Internet service contents, and we have witnessed the emergence of many real-time applications on the Internet. These types of applications require special support from the underlying network such as reliability, timeless, and guaranteed delivery, as well as different levels of service quality. Estimation network status and transcoding data rate are researching for QoS of multimedia service by using the RTP/RTCP. We propose two schemes that the way to calculate the one-way delay by expanding the structure of RTP/RTCP in Internet that provides us 'best effort' service and to estimate the network condition by using this in this paper. And we propose the dynamic RTCP mechanism based on one-way delay to deal with rapidly changed network situation immediately. In simulation, proposed monitoring schemes using the one-way delay has similar in performance to monitoring schemes using the GPS, proposed dynamic RTCP scheme obtain the desired result of decreased packet loss rate by sending RTCP RR packet lower than other schemes.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.1B
• /
• pp.1-12
• /
• 2002

In the multimedia CDMA mobile communication service, it is required to support various applications, such as voice, video, file transfer, e-mail, and Internet access, with guaranteed QoS. In the mixed traffic environment ,which consists of voice, stream data, and packet data, we analyze the network where preemptive priority is granted to delay-intolerant voice service and a buffer is offered to delay-tolerant stream data service. And, for best-effort packet data service, the access control by transmission permission probability is applied to obtain prominent throughput. To analyze the multimedia CDMA mobile communication system, we build a 2-dimensional markov chain model about prioritized-voice and stream data services and accomplish numerical analysis in combination with packet data traffic based on residual capacity equation.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.57-60
• /
• 2003

IEEE 802.16 Wireless MAN standard specifies the air interface of fixed point-to-multipoint broadband wireless access systems providing multiple service. Among the service classes supported by the wireless MAN, the BE class is ranked on the lowest position in priority and is usually deployed by multicast and broadcast polling MAC scheme. In provisioning such BE service, the delay performance is influenced by a number of components including restrictions on resource request per SS, the number of request opportunities in upward frame, scheduling requests at BS, and contention resolution method. As candidate components of MAC function for BE service, we propose single and multiple request schemes (for controling the number of requests per SS), exhaustive and limited request schemes (for regulating the amount of grant per request) and FCFS, H-SMF, pure SMF, SS-wise Round Robin, and pure Round Robin (for scheduling requests at BS). Then, we construct MAC schemes by combining the above components and evaluate the delay performance exhibited by each MAC scheme using a simulation method. From numerical results, we investigate the effect of MAC components on average delay and delay variation and observe the dissonance on collision reduction in a resource - limited environment.