The passive optical network (PON) is widely deployed in access networks, and various specifications have become standards designed to meet demands of each market. To accelerate new PON-based service ...creation, software-defined network enabled broadband access (SEBA) is being studied; it uses a common API to abstract various optical line terminal (OLT)/optical network units (ONUs) and manages the devices via a controller. However, the current abstraction unit in SEBA supports only ITU-T PON. In order to support IEEE PON, multiple package types and switching management functions must be considered. This paper proposes a technology profile including package types for IEEE specification and an adapter that abstracts IEEE PON and switches functions according to the specified package type. The logical link configuration settings for ITU-T PON and IEEE PON are implemented in common, and the adapter abstracts IEEE PON OLT/ONU by switching between extended operation, administration, maintenance (eOAM) functions for package B and other eOAMs. We demonstrate the proposed software on a system implemented using commercially available OLT/ONU and OSS in SEBA. The results show that OLT/ONUs can be managed via a common API, differences in package types can be abstracted by technology profiles and our adapter, and that a common SEBA platform can manage, in a unified manner, both ITU-T PON and IEEE PON.
This paper discusses the future direction of optical access networks and proposes a new optical access architecture that will support the evolution of optical access systems from a fiber-to-the-home ...infrastructure to a common optical access platform that connects various devices and systems to anywhere they want to reach. We describe two technologies for its implementation. One is “modularization,” which is expected to be realized before 2030, and the other is “full softwarization,” which is the longer-term goal of drastically increasing network flexibility. For each technology, we summarize related technical trends and discuss a reasonable system configuration focusing on the access nodes.
This is the second of a two-part paper intended to provide technical insight and rationales behind the recently approved ITU-T G.989.2 Recommendation: the physical media dependent layer specification ...of the 40-gigabit-capable passive optical networks (NG-PON2). While Part 1 of the paper discusses topics related to the optical link design, Part 2 focuses on wavelength control, technology feasibility, management and control channel design, and potential future standardization directions of such a multi-wavelength PON system. As the NG-PON2 system will continue to evolve, technology extensions are also discussed to provide guidance for future research.
Possible configurations of tunable components for the next-generation passive optical network stage 2 (NG-PON2) are reviewed on the basis of system requirements. Expected network functions in NG-PON2 ...systems along with the concept of in-service tuning in colorless ONUs are also reviewed.
This paper shows the concept of the elastic lambda aggregation network (EλAN) that will achieve an elastic common access infrastructure for the metro-access network. It proposes a service restoration ...technique that uses optical path switching and intercentral office handover for EλAN to recover from disasters. The feasibility of the proposed service restoration technique is successfully demonstrated for the first time by using a prototype testbed of a metro-access network. By applying both orthogonal frequency division multiplexing and adaptive modulation, the system automatically changes the transmission parameters (modulation level, the number of subcarriers, and symbol rate) according to the service requirements and conditions of the optical distribution network, such as the link's end-to-end optical loss, in order to achieve accommodate multiple services. In the experiment, an optical network unit in a faulted system automatically reconnected within 10 s to another office 20-km away with the same throughput.
Transition from dedicated devices to general-purpose ones and modularization using a standardized interfacehas been progressed in various fields towards efficient development and cost reduction. In ...recentyears, this movement comes in communication network equipment. This paper introduces the benefitsof modularization and softwarization in optical access networks and reviews the recent works of them.
Real-time access edge computing demands access networks to connect a lot of IoT devices to edge servers with ultra-low latency. A lot of connected devices will cause the data bursts and sudden ...increase of delay (i.e. micro-burst) in the upstream queues in gateways. This study proposes a novel method for detecting such bursts to ensure low-latency communication. The proposed method leverages the periodic messaging behavior of certain IoT devices. It detects bursts based on the variation in the arrival times of messages transmitted from already deployed multiple IoT devices. This approach enables monitoring of delays and detecting bursts without the need for additional probes or modifications to gateways. The study validates the detection accuracy and feasibility through numerical analysis and simulations.
Possible device configurations for the next-generation passive optical network (NG-PON2) are reviewed on the basis of system requirements. The most significant issue is how to cost-effectively ...implement a tunable function in optical components because NG-PON2 introduces a wavelength division multiplexing.
In the radio access network (RAN) infrastructure, fronthaul links territorially disperse remote units (RUs) to distributed units (DUs) in regular or open RAN. With the fifth generation (5G) rollout ...worldwide and the active research on technologies beyond 5G, fronthaul has become a critical part of RAN to balance throughput, delay, reliability, and security. Based on a group of Tier 1 operators' insights on 5G deployment, a recent technology analysis report expects the 5G fronthaul transmission market to reach more than US2 billion in revenue by 2024, almost triple the current rollout.
