Optical transport analyser for 40 Gbit/s SONET/SDH and 43/44 Gbit/s OTN transmission testing

Yokogawa has worked closely with a number of partners in Japan to establish the initial design requirements for a test platform to address the needs of this sector, and has followed that effort up with extensive research in North America and Europe to arrive at the design of the NX4000 NGN tester to meet those needs and to provide unique benefits.

The ability to cleanly transmit data at 40G+ line rates requires special optical modulation techniques such as non-return-to-zero (NRZ), optical duo binary (ODB), differential phase-shift key (DPSK), or differential quadrature phase-shift key (DQPSK). At present, there is no well-defined preference for one particular technique, and so the NX4000 has been designed on a modular basis using field-pluggable cards for each of these techniques.

The NX4000 consists of a mainframe unit containing slots for the NX4100 SONET/SDH base module, an optical interface module for either NRZ at 39.81 and 43.02 Gbit/s (NX4120) or DQPSK at 43.02 and 44.57 Gbit/s (NX4121), and an additional OTN module for 43.02 and 44.57 Gbit/s (NX4110).

The instrument meets OC0768/STM-256 and OTN OTU3 requirements, and can test 44 Gbit/s Ethernet over OTN using four 10 Gbit/s Ethernet channels with over-clocking of the OTU3 interface. It includes ITU compliant tunable DWDM line-side optics, and is compliant with the advanced optical modulation format.

The NX4000 carries out alarm, error, through-mode and full BER measurement of the payload, along with full editing and monitoring of overhead data.