Xuejin Yan

Bio: Xuejin Yan is an academic researcher from Huawei. The author has contributed to research in topics: Passive optical network & Bandwidth (computing). The author has an hindex of 6, co-authored 8 publications receiving 551 citations.

Time- and Wavelength-Division Multiplexed Passive Optical Network (TWDM-PON) for Next-Generation PON Stage 2 (NG-PON2)

Abstract: The next-generation passive optical network stage 2 (NG-PON2) effort was initiated by the full service access network (FSAN) in 2011 to investigate on upcoming technologies enabling a bandwidth increase beyond 10 Gb/s in the optical access network. The FSAN meeting in April 2012 selected the time- and wavelength-division multiplexed passive optical network (TWDM-PON) as a primary solution to NG-PON2. In this paper, we summarize the TWDM-PON research in FSAN by reviewing the basics of TWDM-PON and presenting the world's first full-system 40 Gb/s TWDM-PON prototype. After introducing the TWDM-PON architecture, we explore TWDM-PON wavelength plan options to meet the NG-PON2 requirements. TWDM-PON key technologies and their respective level of development are further discussed to investigate its feasibility and availability. The first full-system 40 Gb/s TWDM-PON prototype is demonstrated to provide 40 Gb/s downstream and 10 Gb/s upstream bandwidth. This full prototype system offers 38 dB power budget and supports 20 km distance with a 1:512 split ratio. It coexists with commercially deployed Gigabit PON (G-PON) and 10 Gigabit PON (XG-PON) systems. The operator-vendor joint test results testify that TWDM-PON is achievable by the reuse and integration of commercial devices and components.

Demonstration of a 40Gb/s time and Wavelength Division Multiplexed passive optical network prototype system

Abstract: We demonstrate a TWDM-PON prototype system with 40Gb/s downstream and 10Gb/s upstream bandwidth. It supports 20km distance with a 1:512 split ratio. It also coexists with commercially deployed G-PON and XG-PON systems.

Wavelength stabilizer for twdm-pon burst mode dbr laser

Abstract: An optical network unit (ONU) comprising a media access controller (MAC) configured to support biasing a laser transmitter to compensate for temperature related wavelength drift receiving a transmission timing instruction from an optical network control node, obtaining transmission power information for the laser transmitter, estimating a burst mode time period for the laser transmitter according to the transmission timing instruction, and calculating a laser phase fine tuning compensation value for the laser transmitter according to the burst mode time period and the transmission power information, and forwarding the laser phase fine tuning compensation value toward a bias controller to support biasing a phase of the laser transmitter.

Next generation passive optical network offering 40Gb/s or more bandwidth

Abstract: This paper reviews PON technologies with a rate of at least 40 Gb/s for the next generation broadband access. The time and wavelength division multiplexed PON (TWDM-PON) is investigated as the primary solution for 40 Gb/s access.

10 Gb/s Upstream Transmission in TWDM PON Using Duobinary and PAM-4 Modulations with Directly Modulated Tunable DBR Laser

Abstract: 10Gb/s upstream transmissions in C-band over 40km are demonstrated for symmetric TWDM PON system using tunable DBR lasers. Compared to NRZ, duobinary and PAM-4 signals with direct modulation result in significantly lower dispersion penalty (~1dB).

Time- and Wavelength-Division Multiplexed Passive Optical Network (TWDM-PON) for Next-Generation PON Stage 2 (NG-PON2)

Abstract: The next-generation passive optical network stage 2 (NG-PON2) effort was initiated by the full service access network (FSAN) in 2011 to investigate on upcoming technologies enabling a bandwidth increase beyond 10 Gb/s in the optical access network. The FSAN meeting in April 2012 selected the time- and wavelength-division multiplexed passive optical network (TWDM-PON) as a primary solution to NG-PON2. In this paper, we summarize the TWDM-PON research in FSAN by reviewing the basics of TWDM-PON and presenting the world's first full-system 40 Gb/s TWDM-PON prototype. After introducing the TWDM-PON architecture, we explore TWDM-PON wavelength plan options to meet the NG-PON2 requirements. TWDM-PON key technologies and their respective level of development are further discussed to investigate its feasibility and availability. The first full-system 40 Gb/s TWDM-PON prototype is demonstrated to provide 40 Gb/s downstream and 10 Gb/s upstream bandwidth. This full prototype system offers 38 dB power budget and supports 20 km distance with a 1:512 split ratio. It coexists with commercially deployed Gigabit PON (G-PON) and 10 Gigabit PON (XG-PON) systems. The operator-vendor joint test results testify that TWDM-PON is achievable by the reuse and integration of commercial devices and components.

Toward an Efficient C-RAN Optical Fronthaul for the Future Networks: A Tutorial on Technologies, Requirements, Challenges, and Solutions

Abstract: The exponential traffic growth, demand for high speed wireless data communications, as well as incessant deployment of innovative wireless technologies, services, and applications, have put considerable pressure on the mobile network operators (MNOs). Consequently, cellular access network performance in terms of capacity, quality of service, and network coverage needs further considerations. In order to address the challenges, MNOs, as well as equipment vendors, have given significant attention to the small-cell schemes based on cloud radio access network (C-RAN). This is due to its beneficial features in terms of performance optimization, cost-effectiveness, easier infrastructure deployment, and network management. Nevertheless, the C-RAN architecture imposes stringent requirements on the fronthaul link for seamless connectivity. Digital radio over fiber-based common public radio interface (CPRI) is the fundamental means of distributing baseband samples in the C-RAN fronthaul. However, optical links which are based on CPRI have bandwidth and flexibility limitations. Therefore, these limitations might constrain or make them impractical for the next generation mobile systems which are envisaged not only to support carrier aggregation and multi-band but also envisioned to integrate technologies like millimeter-wave (mm-wave) and massive multiple-input multiple-output antennas into the base stations. In this paper, we present comprehensive tutorial on technologies, requirements, architectures, challenges, and proffer potential solutions on means of achieving an efficient C-RAN optical fronthaul for the next-generation network such as the fifth generation network and beyond. A number of viable fronthauling technologies such as mm-wave and wireless fidelity are considered and this paper mainly focuses on optical technologies such as optical fiber and free-space optical. We also present feasible means of reducing the system complexity, cost, bandwidth requirement, and latency in the fronthaul. Furthermore, means of achieving the goal of green communication networks through reduction in the power consumption by the system are considered.

Integrated Wireless Backhaul Over Optical Access Networks

Abstract: Recent technological advances and deployments are creating a new landscape in access networks, with an integration of wireless and fiber technologies a key supporting technology. In the past, a separation between those with fiber in the access networks and those with wireless networks, the relatively low data-rate requirements of backhaul and the relatively large cell sites, have all combined to keep fiber deployment low in wireless backhaul. As fiber has penetrated the access network and the latest wireless standards have demanded smaller, higher bandwidth cells, fiber connectivity has become key. Choices remain as to where the demarcation between key elements should be in the network and whether fiber should be used as just a high data-rate backhaul path or if a transition to radio-over-fiber techniques can afford benefits. This paper will explore the network options available in particular those demonstrated in recent European Union (EU) projects, how they can be integrated with existing access networks and how techniques such as radio-over-fiber can be deployed to offer increased functionality.

NG-PON2 Technology and Standards

Abstract: This paper provides a tutorial overview of the latest generation of passive optical network (PON) technology standards nearing completion in ITU-T. The system is termed NG-PON2 and offers a fiber capacity of 40 Gbit/s by exploiting multiple wavelengths at dense wavelength division multiplexing channel spacing and tunable transceiver technology in the subscriber terminals (ONUs). Here, the focus is on the requirements from network operators that are driving the standards developments and the technology selection prior to standardization. A prestandard view of the main physical layer optical specifications is also given, ahead of final ITU-T approval.

New Perspectives on Future Smart FiWi Networks: Scalability, Reliability, and Energy Efficiency

Abstract: Fiber-Wireless (FiWi) network, as an integration of optical fiber network and wireless access network, has attracted intensive research interest and enjoyed significant growth in its applications over the last two decades. Besides bringing great opportunities for the development of FiWi networks, the new applications and techniques, like the emerging Internet of Things (IoT), raise unprecedented challenges in different aspects of FiWi integration. Based on such observation, we provide in this paper a comprehensive survey of recent progress and ongoing research works in the aspects of network architecture, QoS provisioning, scalability improving, reliability enhancing, energy saving, as well as standardization activities and case studies. Furthermore, new trends and challenging issues on future smart FiWi networks are identified and discussed in details.