Joon-Hak Bang

Dynamic gain control of booster amplifier (EDFA) using an optical supervisory channel power adjustment in WDM transmission systems

We present a simple dynamic gain control of a booster amplifier (EDFA-erbium-doped fibre amplifier) with an optical supervisory channel power adjustment in WDM transmission systems. As a result, we performed gain clamping and power clamping of EDFA in the optical link. We can transmit 10 Gbps WDM signals and a 155 Mbps supervisory signal through a single mode fiber 320 km according to the change of signal channel number.

A new design method for TU1n signal alignment, monitoring and switching function in BDCS systems

We review the functions required for TU unit switching and explain the design of TUSM (TU11/TU12 frame alignment and supervisory monitoring), TUTW (TU1n time switch) and TUSW (TU1n space switch) which executes these functions. The VC3 signal termination, and the TUT11/TU12 signal frame alignment and supervisory monitoring function are essential to execute the TU11/TU12 unit switching in the BDCS (broadband digital cross-connect system) with the 50M/150M level and 1.5M/2M level cross-connection function. The TU switch ASIC, applied to a multistage strictly nonblocking switch network, has the merits of transmission bus error detection, combined use of pre/post time switch unit, elevation of system stability using sync memory and provision of a simple switch using 3 port memory. Even though the TU11 and TU12 signals are mixed, it supplies the switching function without any restriction. On the implementation of the switch, we have a serious problem of placement and layout because it includes many networks. However, it prevents any problems to occur at the layout by reducing the available network after memory grouping and makes the entire operation system simple by grouping the connection matrix memory to be controlled and converting the many memory operations into a single memory operation.

TU11/TU12 signal frame alignment and supervisory monitoring ASIC design

In this paper we will go over the functions required for TU unit switching and explain the design of TUSM(TU11/TU12 frame alignment and supervisory monitoring) which executes these functions. VC3 signal termination, TUT11/TU12 signal frame alignment and supervisory monitoring function are essential to execute the TU11/TU12 unit switching in the BDCS (Broadband Digital Cross-connect System) with the 50 M/150 M level and 1.5 M/2 M level cross-connection function. The connection rate of the chip is set to 19.44 Mb/s and it is designed to have signal release/forming, de-multiplexing/muitiplexing of 7 TUG2, frame alignment of 28 TU11 or 21 TU12, VC11/VC12 signal path monitoring function and the monitoring function of signal connection located at the pre/post time switch.