本論文提出一種在分時分波被動光網路中，利用發射機的波長調動機制，實現光網路單元間相互通訊功能。此功能可以應用於下世代行動網路中提供射頻用戶間的交聯功能，大幅縮小用戶間通訊的延遲時間。
實驗架構使用了光纖光柵調諧器的特性，實現光網路單元之間能夠互相連通的功能，滿足低時延的情境需求。在高速率傳輸的情況下，電致吸收調變雷射已成為主要主軸，在本實驗中我們也採用此元件，然而在部分偏壓會造成訊號品質不穩定。將透過電致吸收調變雷射以及遠端單元互連的運作，將兩者建構出實驗跟模擬架構。
藉由適當的波長配置，可以實現上行、下行以及光網路單元間相互傳輸。從頻譜圖跟眼圖的結果，可以得到輸出訊號的明滅比以及品質因子，以驗證傳輸的訊號品質。同時也以實驗方式分析此新型光網路的傳輸效能，在上下行均傳輸10 Gb/s的NRZ訊號，加上不同長度的光纖，並採用前向錯誤更正傳輸誤碼率的條件下，觀察不同傳輸途徑的接收光功率與誤碼率變化。無論實驗與模擬的結果皆證實，在保持原上行與下行傳輸效能外，可以達成光網路單元間相互傳輸的功能。

In this thesis, the interconnection between two optical network units (ONUs) in a time-wavelength division multiplexing passive optical network (TWDM-PON) is realized by incorporating the wavelength tunability in the upstream optical transmitters. The TWDM-PON with ONU interconnect (ONUI) function can be applied to provide interconnection of the remote units (RUI) in the front-hauls of the next-generation mobile networks. The RUI function can reduce the latency for the signal transmission among remote units (RUs).
For the experimental demonstration, architecture utilizes the characteristics of fiber grating tuners to enable connectivity between remote units, meeting the low-latency requirements. In the case of high-speed transmission, electro-absorption modulated lasers (EML) have become the main focus. In this experiment, we also adopted the same laser; however, signal instability was observed at certain bias voltages. The experiment and simulation were conducted to construct a framework involving EML and RU inter-connection.
By wavelength allocation, three transmission modes, including upstream, downstream, and RU inter-connection, can be achieved. From the results of the spectrum and eye diagrams, the extinction ratio and quality factor of the output signals can be obtained, providing insights into the signal quality of the transmission. Finally, to simulate the real conditions of optical network transmission, 10 Gb/s NRZ signals were transmitted in both the upstream and downstream, along with different lengths of optical fiber. And the bit error rate(BER) performance can meet the requirement of forward error correction (FEC). The changes in received optical power and bite error rate for different transmission paths were observed. The results from the experiment and simulation successfully achieved the objectives of the RU inter-connection network.

[1] J. A. d. Peral-Rosado, R. Raulefs, J. A. López-Salcedo and G. Seco-Granados, "Survey of Cellular Mobile Radio Localization Methods: From 1G to 5G," IEEE Communications Surveys & Tutorials, vol. 20, no. 2, pp. 1124 - 1148, 2017.
[2] J. Li, T. Hu, F. Ren, P. Zhu, Q. Mo, Y. He, Z. Li and Z. Chen, "Hybrid Passive Optical Network Enabled by Mode-Division-Multiplexing," in ICOCN 14th, Nanjing, 2015.
[3] T. Sugimoto, T. Shimizu, Y. Akimoto, M. Noguchi, J. Sone, T. Watanabe and Y. Urino, "A Small and Low Cost Bidirectional Transceiver Module with Polymer Waveguide for G-PON/GE-PON," in ECTC 57th, Sparks, NV, USA, 2007.
[4] A. M. Ragheb and H. Fathallah, "Performance analysis of next generation-PON (NG-PON) architectures," in HONET 8th, Riyadh, Saudi Arabia, 2011.
[5] D. Lecrosnier, G. Destefanis, A. Gnazzo, B. Jacobs and M. Pousa, "Optical enabling technologies for access networks: requirements and challenges an overview from FSAN and EURESCOM," in ECOC 24th, Madrid, Spain, 1998.
[6] C. ERIK EKUDDEN, "Five network trends," CTO TECHNOLOGY TRENDS 2021, pp. 1-10, 2021.
[7] C.-J. Chae, S.-T. Lee, G.-Y. Kim and H. Park, "A PON system suitable for internetworking optical network units using a fiber Bragg grating on the feeder fiber," IEEE Photonics Technology Letters, vol. 11, no. 12, pp. 1686 - 1688, 1999.
[8] H. Ueda, K. Okada, B. Ford, G. Mahony, S. Hornung, D. Faulkner, J. Abiven, S. Durel, R. Ballart and J. Erickson, "Deployment status and common technical specifications for a B-PON system," IEEE Communications Magazine, vol. 39, no. 12, pp. 134 - 141, 2001.
[9] K. Tajima, M. Miyabe, T. Shinomiya, H. Yamashita, M. Hirota and M. Kasa, "Asymmetric ATM-PON interface compliant to ITU-T/FSAN standard for global optical access systems," in APCOC, Beijing, China, 1999.
[10] J. Angelopoulos, H.-C. Leligou, T. Argyriou, S. Zontos, E. Ringoot and T. V. Caenegem, "Efficient transport of packets with QoS in an FSAN-aligned GPON," IEEE Communications Magazine, vol. 42, no. 2, pp. 92-98, 2004.
[11] D. Kiycioğlu and N. Ö. Ünverdi, "Applications of FTTX technology in optical communication systems," in SIU 26th, Izmir, Turkey, 2018.
[12] M. Tokoro and K. Tamaru, "Acknowledging Ethernet," in COMPCON, Washington, DC, USA, 1977.
[13] K. Yoshigoe and K. Christensen, "RATE control for bandwidth allocated services in IEEE 802.3 Ethernet," in COLCN 26th, Tampa, FL, USA, 2001.
[14] Y. Lee, D. Lee, H. Yoo, Y. Kim and Y. Kim, "Fast management of ONUs based on broadcast control channel for a 10-gigabit-capable passive optical network (XG-PON) system," Journal of Communications and Networks, vol. 15, no. 5, pp. 538-542, 2013.
[15] R. Dobinson, M. Dobson, S. Haas, B. Martin, M. LeVine and F. Saka, "IEEE 802.3 Ethernet, current status and future prospects at the LHC," in NSS/MIC, Lyon, France, 2000.
[16] K. M. Sharif, N. A. Ngah, A. Ahmad, K. Khairi, Z. Manaf and D. Tarsono, "Demonstration of XGS-PON and GPON Co-Existing in the Same Passive Optical Network," in IEEE ICP 7th, Langkawi, Malaysia, 2018.
[17] Y. Luo, X. Zhou, F. Effenberger, X. Yan, G. Peng, Y. Qian and Y. Ma, "Time- and Wavelength-Division Multiplexed Passive Optical Network (TWDM-PON) for Next-Generation PON Stage 2 (NG-PON2)," Journal of Lightwave Technology, vol. 31, no. 4, pp. 587-593, 2012.
[18] Y. Luo, J. Gao and F. Effenberger, "Next generation hybrid wireless-optical access with TWDM-PON," in WOCC 23rd, Newark, NJ, USA, 2014.
[19] X. Miao, M. Bi, Y. Fu, L. Li and W. Hu, "Experimental Study of NRZ, Duobinary, and PAM-4 in O-Band DML-Based 100G-EPON," IEEE Photonics Technology Letters, vol. 29, no. 17, pp. 1490-1493, 2017.
[20] J. S. Wey, "The outlook for PON standardization: A Tutorial," Journal of Lightwave Technology , vol. 38, no. 1, pp. 31-42, 2019.
[21] H. Shin, Y. Shim and S. Cho, "NG-PON2 Development for 10G Internet Service: A Study Case of SK," in OECC 23rd, Jeju, Korea (South), 2018.
[22] A. K. Garg and V. Janyani, "Direct ONU interconnection schemes towards latency-aware passive optical networks," in ICOCCE, Jaipur, India, 2017.
[23] M. Shirao, T. Fujita, A. Uchiyama, H. Miura, S. Okuda and N. Ohata, "A High-Speed EML on Sub-mount for 200G PAM4," in IPC, Vancouver, BC, Canada, 2022.
[24] Z.-Y. KUO, Design of Hybrid-PON with 50Gb/s High-Speed Signal Transmission Along Single-Mode Fiber, Taipei,Taiwan: NTLTD, 2019.
[25] Y.-H. Wen, K.-C. Feng, L.-W. Chung and S.-L. Lee, "Hybrid PONs with RU Interconnection for Future Mobile Networks," in FOAN, Valencia, Spain, 2022.
[26] 蔡瀞萱, 以超外插法量測電致吸收調變雷射之頻譜特性, Taipei, Taiwan: 國立台灣科技大學碩士論文, 2022.
[27] A. E. Abejide, C. Rodrigues, S. Pandey, M. R. Kota, M. J. N. Lima and A. Teixeira, "Analysis of signal extinction ratio and minimum mean launch power trade-off for type-A ONU 10G transmitter," in ICUMT 13th, Brno, Czech Republic, 2021.
[28] F. Andreas, L. Nikolaos, M. Georgios, P. Ioannis, K. Christoforos and K. Dimitrios, "Design of Optical Network Unit (ONU) for Hybrid," in ICECS, Cairo, Egypt, 2015.
[29] P. I. T. Ivaniga, "Evaluation of the bit error rate and Q-factor in optical networks," IOSR J. Electron. Commun.Eng, vol. 9, no. 5, pp. 01-04, 2014.