• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.63-72
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• 2007

This paper addresses the system development that can transfer data and TDM signals simultaneously by adding TDM pseudowires functions to E-PON system. E-PON technology is one of many technologies which can realize FTTH, has raised as next generation access network solution having both low-cost Ethernet technology and optical infrastructure. TDM pseudowires service is the new voice/data conversion technology which can transfer the existing TDM circuit switched voice and data over packet switching network. In this paper, this system can provide both data and TDM service without deteriorating QoS by adding TDM pseudowires service module to E-PON, and then implementing QoS control function. Therefore, the competitive system which can transfer both data and TDM signal, can be installed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1A
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• pp.1-6
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• 2008

TDM-PON has a disadvantage that entire PON system gets into trouble when only one ONU is out of order and sends optical signal constantly. This paper suggests a scheme to find the fault location. TDMA is impossible when upstream traffic is interrupted by continuous wave signal from a troubled ONU. Therefore, CDMA coding is introduced in separating fault ONUs, and detection algorithm is verified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.741-742
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• 2013

Passive optical networks (PONs) are the emerging solution for access networks since PONs provide high bandwidth. TDM ((time-division multiplexing) PON cannot support sufficient bandwidth for new broadband services such as UHD (ultra high-definition) IP TV, and VOD (video on demand). The solution is TWDM PON which is a mixture of WDM (wavelength-division multiplexing) and TDM. This paper proposes a new MAC (media access control) protocol for TWDM PON.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.465-468
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• 2007

This paper addresses the scheme for transmitting Data and TDM signals based on E-PON. E-PON technology, that combines low-cost Ethernet technology and optical fiber infra-structure, has been appeared as a solution of next generation access network. The transmission speed of E-PON is 1Gbps and symmetric in both direction, such as downstream and upstream. Therefore, it is possible to save the cost through sample network architecture, efficient operation, and low maintenance cost of optical IP Ethernet network. By adding TBMoIP(Time Division Multiplexing over Internet Protocol) module to this E-PON system, and implementing QoS(Quality of Service) control function, this system can provide data and TDM service efficiently.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8B
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• pp.609-614
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• 2008

Upstream data frame of TDM-PON includes various types of overheads, and there exist guard bands between consecutive frames from different ONUs. Although they are indispensible in synchronization and performance, they cause bandwidth waste at the same time. To solve this problem, a new TDM-PON that uses two types of wavelengths in upstream transmission is suggested. By even distribution of two wavelengths among ONUs and overhead overlap between frames that use different wavelengths, almost 100% bandwidth efficiency could be achieved. A serializer that multiplexes signals from two wavelengths is implemented for this purpose.

• Journal of the Korea Society of Computer and Information
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• v.17 no.8
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• pp.51-60
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• 2012

I propose the 5Gbps/1.25Gbps WDM/TDM hybrid Passive Optical Network(PON) with inverse RZ(Return to Zero) code coded downstream and NRZ(Non Return to Zero) upstream re-modulation and analyze its performance by performing simulation with MATLAB. The results have shown that an optical line termination (OLT) can be connected to 8, 16 optical network unit (ONU)s with the Bit Error Rate(BER) of $10^{-9}$ when the distance between OLT and ONU is 10Km and transmitted optical powers are more than -3.8, -0.9dBm, respectively. The proposed WDM/TDM hybrid PON system can solve the problem of data rate limit in upstream which happened in the conventional TDM PON because the upstream data rate is proportional to ONU and does not require a light source in ONU and its control circuits in OLT, thus can be a useful technology for asymmetric optical subscriber networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9B
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• pp.777-784
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• 2006

In this paper, we propose the PON-based access network based on conventional TDM-PON architecture, which utilizes WDM wavelength channel and bandwidth dynamically. It is also described a dynamic MAC protocol in order to increase the number of subscribers and efficiency of resource utilization. Of particular importance in the proposed approach for MAC protocol is that the wavelength channel and time slot for up/downlink is dynamically allocated according to the required QoS level and the amount of data in data transmission, through the dedicated control channel between OLT and ONU. We evaluate the performance of average packet end-to-end delay in a statistical analysis and numerical analysis. In addition, through simulations with various traffic models, we verified the superior performance of the proposed approach by comparing with the results of other E-PONs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2B
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• pp.83-89
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• 2007

In this paper, we have proposed the power detection (PD)-based TDM-PON architecture, which is implemented with a hardware-based decentralized DBA (Dynamic Bandwidth Allocation) algorithm among ONUs, without OLT's intervention. Of particular importance in the proposed approach is that the hardware-based power detection scheme is used to manage the distributed MAC algorithm without any complex, time-consuming and costly software-processing elements for DBA in ONUs and OLT. We evaluate the performance of average packet end-to-end delay in a statistical analysis and numerical analysis. In addition, through simulations with various traffic models, we verified the superior performance of the proposed approach by comparing with the results of other E-PONs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1419-1424
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• 2013

Passive optical networks (PONs) are the emerging solution for access networks since PONs provide high bandwidth and the low operation cost. In recent, the new solution in access networks is TWDM PON which is a mixture of WDM (wavelength-division multiplexing) and TDM (time-division multiplexing). This paper proposes a new MAC (media access control) protocol for TWDM PON. In addition, this paper proposes and evaluates a new dynamic bandwidth allocation method for TWDM PON.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7B
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• pp.427-432
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• 2005

Emerging high broad band multimedia service with high quality has led to demand for challenge of optical access network and Passive Optical Network is one of the most important technologies for future optical access network. In this paper, we study the scheduling algorithm for WDM-PON in SUCCESS network architecture, a next generation hybrid WDM/TDM optical access network architecture. Due to economic implementation of this architecture, the shared resources efficiently need to be assigned and then we propose the efficient scheduling algorithm based on specific architecture and characters of SUCCESS. We evaluate and analyze the performance in terms of the average packet delay and throughput of the whole system.