Bheom Soon Joo

OAM and its performance monitoring mechanisms for carrier ethernet transport networks

Ethernet technology is rapidly gaining importance as it becomes a dominant solution for a converged transport network. Ethernet OAM features defined in standards provide a means of performance improvement to meet carrier-class transport network requirements. This article outlines Ethernet OAM functions and mechanisms, and explains how its performance monitoring schemes work. In addition, this article introduces open issues and their potential solutions in the performance monitoring of Ethernet OAM for the next phase of standardization.

Modular and flexible architecture of wavelength-OTN-packet converged platform

This paper presents the architecture of integrating the technologies of lambda switching, OTN mapping/switching and connection-oriented Ethernet for the solution of transport network. Our new wavelength-OTN-packet converged platform is a combined system of a WSS-based ROADM, a ODUk-based switching node, and a connection-oriented Ethernet aggregation /switching node with the modular and flexible architecture. The architecture enables telecom operators to reduce the network cost and to increase the value of their networks.

Ethernet ring protection with managed FDB using APS payload

Ethernet ring protection (ERP) is a new technology based on OAM (operations, administration, and maintenance) being standardized by the ITU-T G.8032 working group. In this paper, we present the recent development of Ethernet ring protection which is called FDB (filtering database) flush scheme and propose a new Ethernet ring protection technique introducing a managed FDB using APS to deliver information how to fix FDB selectively. We discuss the current development of the ERP technology at ITU-T and performance comparisons between different proposals.

Effective fault management for hierarchical OTN multiplexing using tandem connection monitoring coordinates

We propose and verify fault management method using tandem connection monitoring for OTN multiplexing hierarchy through experiments on fiber-cut event. Marking defects on TCM coordinates that consists of TCM levels and ODU trails, and identifying a root-cause of faults using two consequent actions of trail signal fail and server signal fail are newly presented as means to find fault-originators and root-causes. By effectively managing multiple faults all over the network and all over the hierarchical OTN layers, the fault management method could contribute toward the enhanced OAM for fast end-to-end service maintenance and fast restoration.

Resolution enhancement of correlated OTDR using eigen-decomposition based algorithm

This paper investigates the resolution enhancement of correlated OTDR using Eigen-decomposition based algorithm. The algorithm separates the space spanned by the measured data into what are called noise and signal subspace and then pseudo-spectrum is calculated by using signal steering vector and noise subspace matrix. Attenuation dead zone of the correlated OTDR is improved up to 45 % by the Eigen-decomposition based algorithm.

Optical signal-to-noise ratio monitoring in optical transport networks using OXCs or reconfigurable OADMs

We propose and experimentally demonstrate a simple method for monitoring optical signal-to-noise ratio. The novel method can be used in the optical transport networks using optical cross-connects or reconfigurable optical add-drop multiplexers. OSNR is measured by monitoring the transmitted optical power and the reflected optical power from fiber Bragg grating. We have obtained OSNR with an error less than 0.8 dB.

Carrier Ethernet System Supporting Flexible Media Management

The paper relates to a Carrier Ethernet system supporting multiple media, a medium managing method therefore, and a switching system using the same. More particularly, this relates to an Ethernet port supporting multiple physical media that can use and manage multiple transmission media by freely selecting and exchanging the transmission media with another one in a switching system using ports, such as switches and routers, a medium managing method therefore, and a switching system using the Ethernet port. In other words, a system user forms two different types of physical media, which are copper cable and optical cable, in the switching system that can include multiple Ethernet ports, upon a request from the user, and exchanges and substitutes the physical media flexibly with another media in the operation of the switching system. This method offers an advantage to network operator and systems developer and also reduces system price.