• Journal of Digital Convergence
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• v.17 no.8
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• pp.229-235
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• 2019

As the demand for broadband multimedia including the Internet explosively increases, the advancement of the subscriber network is becoming the biggest issue in the telecommunication industry due to the surge of data traffic caused by the emergence of new services such as smart phone, IPTV, VoIP, VOD and cloud services. In this paper, we have developed WDM(Wavelength Division Multiplexing)-PON(passive optical network) based on the 1-Gigabit Reach Externder (RE) technique to reduce optical core. Particularly, in order to strengthen the market competitiveness, we considered low cost, miniaturization, integration technique, and low power of optical parts. In addition, we have developed a batch system by integrating all techniques for reliability, remote management through the development of transmission distance extension and development of capacity increase of optical line by using RE technology in existing PON network. Based on system interworking with existing commercial 1G PON devices, it can be worthy of achievement of wide nationalization and optical core reduction by using this developed system. Based on these results, we are studying development of 10G PON technology.

• Electronics and Telecommunications Trends
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• v.30 no.1
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• pp.42-50
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• 2015

PON(Passive Optical Network)은 설치 및 유지보수가 편리하여 광가입자망으로 널리 사용되고 있다. 대표적인 PON 기술로 IEEE에서 표준화된 EPON(Ethernet PON), 10G EPON과 ITU-T에서 표준화된 GPON(Gigabit capable PON), XG-PON 기술이 있다. EPON 및 GPON은 각각 1G급 및 2.5G급 전송속도를 제공하며 한국, 일본, 중국 등 아시아와 북미 등에서 가입자 서비스 및 비즈니스 서비스용으로 사용되고 있다. 2010년대부터 10G급 PON 기술 사용이 증가되고 있으며, 앞으로 가파르게 증가하고 있는 가입자 트래픽량에 대처하기 위해 40G급 또는 100G급 PON 기술이 사용될 것으로 예상된다. 본고에서는 현재 ITU-T에서 표준화가 진행 중인 NG-PON2(Next Generation PON2) 기술 중 주요기술인 TWDM-PON(Time and Wavelength Division Multiplexing-PON) 기술에 대한 국제 표준화 현황 및 국내외 기술개발 현황을 살펴보고자 한다.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.117-120
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• 2003

PON (Passive Optical Network) is an emerging local subscriber access architecture that provides more bandwidth and services to subscriber than DSL (Digital Subscriber Line and HFC (Hybrid-Fiber Coaxial) network. A PON is a point-to-multipoint optical network with no active elements in the signals' path from source to destination. Advantages of using PON for a subscriber access network include large coverage area, reduced fiber deployment, multicast and broadcast capabilities, reduced cost of maintenance (due to devices being passive), and ease of upgrades to higher bit rate or additional wavelengths. PON uses WDM (Wavelength Division Multiplexing) technique that transmits the downstream and upstream data at each different wavelength. For transmitting the CATV (Community Antenna television) service through PON network, we give out additional wavelength. This study shows the available TPS (Triple play service) architecture using CATV overlay EPON (Ethernet PON) architecture and analyzes the effects of EPON-based CATV transmission by measuring the power loss fur each wavelength and the power range of the available analog wavelength and RF.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.104-109
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• 2021

In this paper, we experimentally demonstrate a self-seeding FP-LD (Fabry Perot Laser Diode) to verify the possibility of a new tunable light source that can be used in WDM-PON (Wavelength Division Multiplexing - Passive Optical Network) system. The conventional implementation of WDM-PON using a tunable light source has a disadvantage that the center wavelength of the AWG (Arrayed Waveguide Grating) device and the tunable light source must be precisely aligned. However, the proposed tunable light source has the advantage that the tunable wavelength is automatically aligned with the center wavelength of the AWG as well as simple structure. The implemented tunable light source had a tunable band of about 14 nm or more, and the maximum RIN (Relative Intensity Noise) of about -124 dB/Hz, which showed the possibility of modulating 10 Gb/s signal by an external modulator.

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.222-226
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• 2011

We demonstrated the feasibility of an amplified wavelength-division multiplexed passive optical network (WDM-PON) architecture based on broadband light source (BLS) seeded optical sources and a novel bidirectional reach extender. Our bidirectional reach extender could provide an amplification of both downstream and upstream signals as well as a BLS output for the upstream WDM signal generation. An error-free 1.25 Gb/s signal transmission over a 100-km long single-mode fiber was achieved in a bidirectional WDM-PON using BLS seeded reflective semiconductor optical amplifier (RSOA) sources.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.4
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• pp.162-169
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• 2020

In this paper, we attempted a qualitative understanding of mutual injection locking without rigorous mathematics, and analyzed the proposed mutual injection locked light source. Also, a low-cost WDM-PON light source based on mutual injection locking using two unpolarized Fabry-Perot Laser Diodes (F-P LDs), was implemented. The RIN (Relative Intensity Noise) characteristic for the wavelength change of the F-P LD was measured, and when the variable wavelength range was 2.07 nm, it showed a RIN of at least -110 dB/Hz.

• Electronics and Telecommunications Trends
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• v.27 no.3
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• pp.164-174
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• 2012

향후 10년 내에 전 세계적으로 인터넷 인구가 50억 명에 이르고 사물지능통신의 발달로 인해 인터넷에 접속되는 기기가 1,000억 대로 급증할 것으로 전망된다. 또한, video 콘텐츠를 비롯한 초대용량 서비스, 무선 인터넷 서비스 등이 활성화되고, 트래픽이 폭증할 것으로 예측된다. 그러나 60년대 후반에 만들어진 인터넷은 이러한 새로운 서비스의 등장 및 인터넷 트래픽의 폭증에 적절히 대응하기에는 많은 한계를 가지고 있다. 따라서 미국, EU, 일본 등 선진국들은 네트워크의 양적인 확충은 물론, 새로운 인터넷 기술을 개발하고 그 구조를 재설계하기 위해서 경쟁적으로 대대적인 투자를 전개하고 있다. 광가입자망은 이러한 급변하는 가입자망의 변화에 효과적으로 대처할 수 있는 기술로써, 인터넷 서비스 사업자와 가입자를 연결하는 중요한 네트워크이다. 본고에서는 대표적인 광가입자망 기술인 TDM-PON(Time Division Multiplexing-Passive Optical Network) 및 WDM-PON(Wavelength Division Multiplexing-Passive Optical Network)의 전반적인 기술 현황, 국제 표준화 동향 및 시장 동향에 대해 소개하고, 앞으로 미래를 대비하기 위해 필요한 광가입자망의 기술개발 방향에 대해 논하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.59-67
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• 2006

We demonstrate bidirectional long-reach 35-channel dense wavelength division multiplexing-passive optical network(DWDM-PON) based on wavelength-locked Fabry-Perot laser diodes (F-P LDs). The mode control of F-P LD enhances output power at decreased the required injection power. We show packet-loss-free transmission in all 70 channels at 125 Mb/s per channel line rate through 70 km of single mode fiber without optical amplifier The DWDM-PON can consolidate a metro network into an access network by bypassing the central offices within its reach. The proposed DWDM-PON can accommodate about 80 subscribers with an EDFA-based broadband light source. Further expansion up to 100 subscribers is possible with a semiconductor-based BLS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.743-744
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• 2013

This paper proposes a new DBA (dynamic bandwidth allocation) algorithm for a TWDM PON (time and wave-division multiplexing passive optical network) which is based on XGPON (10-Gigibit-Capable PON). Modifying a DBA algorithm of an XGPON, the proposed algorithm not only allocates the transmission slot but also assigns a wavelength to use for each ONU.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1785-1796
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• 1998

This paper is concerned with the relationships between optimal number of wavelengths and tuning time in time division multiplexing(TDM) scheduling on wavelength division multiplexing(WDM) optical passive star networks. We assume that the traffic is nonuniform and each node has a tunable transmitter and a fixed receiver. Each node transmits spckets to all other nodes. Most of the earlier protocols on TDM based scheduling for WDM star networks [7, 8, etc.] use whold given wavelength chnnels. But in this paper, we investigate the optimal number of wavelengths that yidels minimum frame length when tuning time exists. It appears within the availble number of wavelengths that yields minimum frame length when tuning time exists. It appears within the available number of wavelengths. We analyze the relationships between optimal number of wavelengths and tuning time by experiments. We analyze the reationships between optimal number of wavelengths and tuning time by experiments. We also discuss on the possibility of reduction of frame length by increasing the number of nodes trans-mitters and receivers.