Oliver Jahreis

PHOTONET WDM Supervision

An all optical field trial network, named PHOTONET, is described. It employs a star topology with one optical cross connect. Multi-channel signals assembled by wavelength division multiplexing (WDM) are transported over more than 500 km of standard single mode fibre installed in the field. Erbium doped fibre amplifiers and dispersion compensating fibres will balance attenuation and, partially, pulse shape distortion along the links. To demonstrate the service of the network, that is the transport of high bit rate data streams, equipment will be connected to the optical network using 2.5 Gbit/s signals of the synchronous digital hierarchy (SDH). Additionally, newly developed equipment for 10 Gbit/s SDH signals will be employed.

A Transponder for Gigabit Ethernet over WDM

The deployment of Gigabit Ethernet in corporate and ISP networks makes the transmission over WDM networks necessary to provide for the interconnection over metropolitan and wide area WDM networks. As the specifications of the optical signal between Gigabit Ethernet and the WDM-network mismatch, a transponder is needed. We propose an architecture for a Gigabit Ethernet over WDM transponder and report on a transponder prototype implementation. We further show how to use the transponder for Gigabit Ethernet networks over WDM rings.

WDM supervision in PHOTON as a basis for OAM of all-optical transport networks

A key issue for the Operation & Maintenance (OAM) of an all-optical transport network is failure localisation in the network. The WDM supervision concept in the ACTS project PHOTON (Photonic Transport Overlay Network) achieves this by the introduction of defects and maintenance signals similar to existing transport networks. In the following this concept is explained.

Realization of a passive broadband-network termination 1 (B-NT1) for the optical user-network interface

A new passive Broadband Network Termination 1 (B-NT1) as an alternative to the active B-NT1 for B-ISDN is described which supervises the U B interface between B-LT and B-NT1. For this purpose, the B-LT generates an additional pseudo noise (PN-)signal which is reflected at the passive B-NT1 and analysed by a correlation method in the B-LT. The alarm flow between B-LT and the B-NT2 remains unchanged by introducing a new reflection alarm REFL in the B-LT which is based on the evaluation of the correlation signal and describes the condition of the U B interface. The passive B-NT1 concept offers a more economical alternative for the network operator to provide Operation and Maintenance (OAM) on the T B and U B interface