• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.160-161
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• 2005

A critical issue in implementing efficient Ethernet passive optical network(EPON) System is the bandwidth allocation algorithm. The overall goal of bandwidth allocation is to effectively and fairly perform scheduling of time slots between ONUs in EPON System. We propose a new algorithm of dynamic bandwidth allocation for improved bandwidth efficiency in EPON system.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.251-256
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• 2012

In this paper, we addressed the problem of upstream bandwidth in EPONs. We presented a wavelength division EPON supporting QoS in the differentiated services framework. It was shown that the bandwidth allocation by priority scheduling, under our assumptions for traffic behavior, will result in an unexpected behavior for high priority class and we suggested the use of weighted priority scheduling to alleviate this problem. Our wavelength division EPON supporting QoS allocates effectively and fairly bandwidths and wavelengths between ONUs in the differentiated services framework. Moreover, we showed better performance in terms of average and maximum end-to-end delay, as well as network throughput, utilization compared with some other algorithms. We used simulation experiments to study the performance and validate the effectiveness of the proposed network and algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.5 s.335
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• pp.1-4
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• 2005

This paper deals with the mechanism and control protocols required in order to reconcile the P2MP topology into the Ethernet framework. This paper specifies the multi-point control protocol(MPCP) to operate an optical multi-point network. Also it is applied to method of bandwidth limitation of downstream traffic

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1455-1458
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• 2002

최근 가입자 망에서 다양한 멀티미디어 서비스를 저가이면서 간단한 망구조를 갖고 확장성이 뛰어나며 데이터, 음성, 비디오 서비스를 효율적으로 수용할 수 있는 EPON 기술이 요구되고있다. EPON은 하나의 OLT와 다수의 ONU가 PTMP 구조로 연결된다. OLT는 백본망에 연결되고, ONU는 가입자에 연결된다. 하나의 ONU 가 트래픽을 전달하기 위해서는 OLT 로부터 타임 슬롯을 할당 받는다. 따라서 주어진 타임슬롯에 IDLE 구간 없이 최대한으로 전송대역을 이용하기 위해서는 ONU 내에 트래픽 동적 스케줄러가 요구된다. 또한 다양한 어플리케이션의 요구를 지원하기 위해 스케줄러는 CoS가 지원되어야 한다. 따라서, 본 논문에서는 OLT와의 Auto-discovery, Laser_On/OFF기능 등 가입자에게 EPON 기능을 제공하며, 다양한 서비스를 제공하도록 CoS 기반 스케줄러를 수용한 EPON ONU 의 MPCP(Multi-point Control protocol)를 구현하였다.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.182-189
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• 2005

In this paper, an asymmetric WDM-EPON transmission scheme is proposed to be used in a high speed access network system, which is required to implement the convergence of broadcast and communication. WDM is used for downstream transmission from OLT to access nodes, satisfying wide bandwidth requirement for broadcasting and various multimedia services. And an EPON scheme, which is cheaper than WDM, is applied to upstream transmission where less bandwidth is required. A transmission test in physical layer was performed successfully and the results are provided. If ONUs are to be used in a home gateway, its protocol should be appropriate to its traffic pattern. Voice is sensitive to a time delay while data is not. A new dynamic bandwidth assignment protocol for PON system, which can cope with various types of data in access network is proposed and its performance is analysed. A maximum cycle time is specified to achieve the QoS of signals sensitive to time delay. And a minimum window is specified to prevent the downstream control signals from uprising. It is shown by simulation that the proposed EPON protocol can provide a better performance than previous ones.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6B
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• pp.531-537
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• 2004

EPON which is the economical technology of FTTH is being actively researched as one of next generation of subscriber configurations. EPON based on Ethernet should provide subscriber with dynamic bandwidth allocation so as to support QoS. Allocation per service in grade should be satisfied resulting from the increment of the latest multimedia application arid consumption. In this paper, New Algorithm is proposed to serve differential service on MAC protocol. The delay characteristic of packet and stability are analyzed that is shown the QoS of EPON network.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.679-686
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• 2005

Because EPON access network shares a medium and aggregates the traffic from EPON subscribers, scheduling media access control on EPON bandwidth allocation is very important. Furthermore DBA mechanism of EPON based on TDMA is out of specification and up to implementation. This paper deals with a DBA method to guarantee the QoS of the delay sensitive traffic on the base of best-effort service and delay priority queue management. The proposed method performs virtual scheduling algorithm for the integrated traffic. It uses the same MAC messages and tries to guarantee the QoS of higher priority traffic first with a simple DBA architecture. We evaluate the algorithm for traffic delay according to polling interval and traffic load of upstream and downstream. The results show that the proposed method can guarantee the QoS of the delay sensitive traffic with priority of the service classes.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.525-526
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• 2006

Ethernet Passive Optical Networks (EPON) are an emerging access network technology that provide a low-cost method of deploying optical access lines between a central office (CO) and a customer site. This paper shows that subscriber unit manages traffic data between a central office (CO) and a customer site in economic solution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.929-934
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• 2006

A scheme to easily upgrade TDM-PON using WDM overlay is proposed. To maintain the colorless characteristics of ONU transmitters, a wavelength-conversion ONU is adopted for each TDM-PON group, where all upstream signals from regular ONUs are adjusted to an assigned wavelength. An implementation scheme for remote node and wavelength conversion node is suggested and the test results are shown.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.224-231
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• 2008

EPONs are a low cost, high speed solution to the bottleneck problem of broadband access networks. To support point-to-point and shared LAN emulation, EPONs use the multi-point control protocol (MPCP), which uses logical link identification (LLID) for frame tagging and filtering between the OLT and ONUs. In this paper, ONU-based multicast or multiple shared LAN emulation is used for IPTV channel package delivery services. Using ONU-based VLAN services, EPONs can support separate and secure connections between providers and subscribers in a simple manner. Also, IPTV channel packages can be delivered through EPONs by implementing ONU-based VLAN and IGMP snooping mechanisms. By showing fast channel zapping time of proposed architecture, I show that EPONs is suitable for IPTV channel package delivery service.