Optical Transport Network

About: Optical Transport Network is a research topic. Over the lifetime, 6055 publications have been published within this topic receiving 85783 citations.

Wavelength access server (WAS) architecture

Abstract: A wavelength access server (WAS) architecture provides aggregation of traffic streams of diverse data communication protocols as well as provision of wavelength resources in an optical transport network. The WAS provides functions such as service traffic adaptation, traffic aggregation and segmentation, traffic classification, optical inter-working and system management. In particular, system management includes aspects such as signaling, connection management, resource co-ordination, protection prioritization and access policy management.

Off-line algorithms for Routing, Modulation Level, and Spectrum Assignment in elastic optical networks

Abstract: Optical network architectures with elastic bandwidth provisioning are a very promising approach for next generation optical networks. Such elastic optical networks will enable efficient resource utilization and flexible sub-wavelength and super-channel connection provisioning to support heterogeneous and immense bandwidth demands. In this paper, we focus on the problem of Routing, Modulation Level, and Spectrum Allocation/Assignment (RMLSA) which emerges in such networks. We both formulate RMLSA as an Integer Linear Programming (ILP) problem and propose an effective heuristic method called Adaptive Frequency Assignment - Division and Collision Avoidance (AFA-DCA) to be used if the solution of ILP is not attainable.

Optical phase coding for code-division multiple access networks

Abstract: An all-optical code-division multiple access (CDMA) network is presented which uses optical phase information to encode and decode transmitted data from a low-coherence source, using simple, compact, reconfigurable optical delay networks. The use of a master encoding network to provide a reference for the system is demonstrated experimentally, and examples of phase codes ensuring minimum interference between users are given. >

Efficient and reliable protection mechanism in long-reach PON

Abstract: Network survivability and protection mechanisms are very important and necessary in optical networks. The long-reach passive optical network (LR-PON) proposed in this paper extends the access network to hundreds of kilometers, and it can support more optical network units by wavelength division multiplexing technology. We propose an efficient protection mechanism for the whole LR-PON. Optical encoders are used to monitor the whole network, and a network management system in the central office will initialize the protection process by monitoring the information it collects. When the network works normally, space division multiplexing technology is adopted to reduce the loss and crosstalk of signals. The designed system propagates the upstream and downstream signals in different fiber rings to mitigate the influence of Rayleigh backscattering. The proposed protection mechanism can protect the network from the multi-faults of fiber links with the designed switches. Furthermore, the loss, availability, costs, and network performance are also studied. The results obtained prove the feasibility of the proposed network. The network is costless and reliable, and it has high availability of up to 99.9992% by the protection mechanism.

Enhancing the survivability and power savings of 5G transport networks based on DWDM rings

Abstract: So much has been promised by the fifth generation (5G), the revolution of mobile communications that allows for flexible, speedy, and efficient delivery of unlimited data and information sharing between people located anywhere and at any time. The road toward making 5G a reality, however, requires concerted efforts in designing both the underlying infrastructure and the enabling technologies to simultaneously satisfy not only capacity but also reliability, low latency, synchronization, security, and energy consumption requirements. In that respect, the transport segment of a 5G network, i.e., the backhaul network of mobile base stations (BSs) or fronthaul of remote radio units (RRUs), must not be overlooked. Further, any future design of a resilient 5G transport network must also consider the potential exploitation of switching on and off network resources such as RRUs and BSs to improve energy efficiency. At present, there are few inroads on 5G transport networks that provide resilience during sleep mode operation. Therefore, the focus of this work is aimed specifically at providing solutions to enhance both the survivability and power savings of mobile transport networks that implement sleep mode operation. We develop our solutions around a dense wavelength-division multiplexed (DWDM) optical ring transport network that has been previously proven to be energy efficient as a 5G transport network. Further, we propose two survivable schemes that exploit the inherent resiliency of the ring network. In conjunction with cw monitoring signals and highly sensitive monitoring modules, these schemes facilitate for the first time continuous monitoring of the network at all times, even during idle periods of transmission when transceivers are sleeping. That is, our proposed schemes enable network energy savings through sleep mode operation without having to compromise on failure detection time. Compared to a conventional ring architecture, our survivable schemes provide enhanced connection availability and power savings at less than 0.2% incremental network cost. Based on performance evaluations for brownfield, duct reuse, and greenfield deployments, we provide guidance on the most suitable scheme for each considered scenario, thus driving the future choices of mobile network operators.