• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.289-292
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• 2007

FTTH (Fiber to the Home) is constructed with optical devices and optical cables from central office (CO) to subscribers. With FTTH, it is possible to provide service platform in order to meet the customers' emerging demands for more bandwidth/security and diverse IP multimedia applications including high definition (HD) video streaming service. FTTH can provide enough bandwidth from 100Mbps to several Gbps per subscriber. It is also most appropriate network architecture for convergence of communication and broadcasting. So, FTTH is thought the final destination of telecom operators, since it is the fastest and most reliable solution so far and various IP multimedia services are possible through it. In this paper, newly attempted technologies of FTTH construction for apartment complexes using CWDM-PON system are discussed.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.73-74
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• 2006

In this paper, we designed, constructed and evaluated the system for the FTTH suited to a residence and apartment using CWDM-PON techniques. These systems have capacity to service at 100Mbps rate to 384 users in the same breath. Also, the services include the internet, CATV, IPTV and wireless LAN. In the case of wire network, the data could be transmitted by UTP cable and optical fiber and case of wireless one, the data transmitted using WLAN. The distance between the cental office and the user is 20km and the data rate is 100Mbps maximum. Of course, the optical network used just one fiber optical core. For the basic material, we obtained the characteristics of optical transceiver module, Mux/Demux and transmission qualities depends on the environment.

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.276-277
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• 2004

• Current Optics and Photonics
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• v.1 no.5
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• pp.514-524
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• 2017

We proposed an integrated wavelength-selective photodetector based on a grating-assisted contradirectional coupler and a graphene absorption layer for a coarse wavelength division multiplexing (CWDM) communication system. The center wavelength of the absorption spectrum of the proposed device can be tuned simply by changing the period of the grating, and the proposed device structure is suitable to forming a cascaded structure. Therefore, an array of the proposed device of different grating periods can be used for simultaneous wavelength demultiplexing and signal detection in a CWDM communication system. Our theoretical study showed that the designed device with a grating length of $500{\mu}m$ could have an absorption of 95.1%, an insertion loss of 0.2 dB, and a 3 dB bandwidth of 7.5 nm, resulting in a -14 dB crosstalk to adjacent CWDM channels. We believe that the proposed device array can provide a compact and economic solution to receiver implementation in the CWDM system by combining functions of wavelength demultiplexing and signal detection.

• 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.77-83
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• 2006

In this paper, we designed, constructed and evaluated the system for the FTTH suited to a residence and apartment using CWDM-PON techniques. These systems have capacity to service at 100Mbps rate to 384 users in the same breath. Also, the services include the internet, CATV, IPTV and wireless LAN. In the case of ire network, the data could be transmitted by UTP cable and optical fiber and case of wireless one, the data transmitted using WLAN. The distance between the cental office and the user is 20km and the data rate is 100Mbps maximum. Of course, the optical network used just one fiber optical core. For the basic material, we obtained the characteristics of optical transceiver module, Mux/Demux and transmission qualities depends on the environment.

• ETRI Journal
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• v.34 no.6
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• pp.838-846
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• 2012

This paper proposes a cost-effective hybrid-type power budget extender (PBEx) that can provide a high power budget of over 45 dB in an asymmetric 10-Gb/s Ethernet passive optical network (10/1G-EPON). The hybrid-type 10/1G-EPON PBEx comprises a central office terminal (COT) and remote terminal (RT) module supporting four channels and uses a coarse wavelength division multiplexing (CWDM) technology between the COT and RT for a reduction of fiber cost and efficient access network design. The proposed 10/1G-EPON PBEx can provide over a 40-km reach and 128-way split per CWDM wavelength with no modification of a legacy 10/1G-EPON system and can satisfy the error-free service in $10^{10}$ packet transmission.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.185-189
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• 2007

A novel technology for CWDM (Coarse Wavelength Division Multiplexer) utilizing a PLC (Planar Lightwave Circuit)-AWG (Arrayed Waveguide Grating) fabrication process is proposed. BPM (Beam Propagation Method) Simulation results on the employed parabolic-horn-type input slab waveguide of AWG and the performance of the 20 nm-channel spacing CWDM with flattened passband are presented. Waveguides of $0.75{\triangle}%$ have been used in this experiment and the insertion loss at the peak wavelength is 3.5 dB for a Gaussian spectrum and is 4.8 dB for a flat-top spectrum. The bandwidth at 3 dB is better than 10 nm and 13 nm for Gaussian and flat-top spectra, respectively.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.188-189
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• 2002

기간망의 속도 증가와 더불어 가입자망치 고속화는 필수 불가결한 것으로 이를 위해 메트로 네트웍의 고속화에 대한 노력이 진행되고 있다. 메트로 네트웍 및 가입자망의 고속화를 위해서는 시스템의 저가화가 필요하다. CWDM(Coarse WDM)은 채널 간격이 10 - 25nm로 채널 간격이 넓기 때문에 복잡한 온도제어 없이 저가의 Uncooled DFB-LD 및 WDM 소자를 사용할 수 있어서, 메트로 네트웍의 대용량화를 보다 경제적으로 실현가능하기 때문에 CWDM 시스템이 유망한 것으로 받아들여지고 있다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.14-15
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• 2004

본 연구는 가입자망에 적용하는 CWDM 시스템에 대한 기본적인 소개와 제작한 시스템의 온도특성을 측정한것이다. 8채널과 16채널용 system을 제작하였으며 온도의 변화에 따른 광출력특성 및 파장변화특성을 측정하였다.

• ETRI Journal
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• v.31 no.2
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• pp.231-233
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• 2009

We propose a nonreciprocal filter based on coarse wavelength division multiplexing (CWDM) that reduces the upstream channel insertion loss in a passive optical network (PON). We also propose a method to increase the number of channels/optical network units (ONUs) in PON systems using the proposed filter to reduce the service cost per subscriber. Experimental results show that the PON system with the proposed 4-channel filter can reduce the power budget of the upstream and increase the number of ONUs by 3 to 4 times that of a conventional time-division multiplexing PON.