Hello everyone!
This post will share with you differences between FIU, SFIU, and XFIU.
As an optical multiplexer and demultiplexer unit, the FIU board multiplexes the main path signals and OSC signals into a single communications channel, and demultiplexes these signals. FIU boards include FIU and SFIU boards as well as XFIU modules that are integrated into DAPXF, SRAPXF, WDAPXF, and WSMD9XF boards. This document describes the differences between FIU, SFIU, and XFIU in application scenarios.
FIU
The OSC signals of the FIU boards are transmitted in two-fiber bidirectional mode, and the OSC and main optical path signals are always transmitted in the same direction.
The FIU boards support optical-layer ASON scenarios but do not support IEEE 1588v2 compensation-free scenarios. For positions of the FIU boards in a WDM system, see Figure 1 Application of FIU boards in a WDM system.
SFIU
Compared with the FIU board, the SFIU board uses two different wavelengths (1491 nm and 1511 nm) for the leave and return OSC signals. In this way, the OSC signals can be transmitted in a single-fiber bidirectional manner, avoiding transmission latency differences of OSC signals in different fibers. Therefore, compensation-free IEEE 1588v2 can be achieved. SFIU boards are mainly used in IEEE 1588v2 scenarios.
However, the SFIU boards do not support optical-layer ASON. For positions of the SFIU boards in a WDM system, see Figure 2 Application of SFIU boards in a WDM system.
Note:
The OSC board that works with the SFIU board must be an OSC board that can transmit and receive 1491 nm and 1511 nm wavelengths at the same time.
XFIU
The XFIU module integrates two groups of RM and TM ports and can multiplex and demultiplex the main optical path and two OSC signals at the same time. Depending on fiber connections on ports, the XFIU board supports three working modes: FIU, single SFIU, and two SFIUs. Currently, the XFIU modules are integrated into other boards, such as the DAPXF, SRAPXF, WDAPEXF, and WSMD9XF.
The following uses the DAPXF board as an example to describe the application of the XFIU module in a WDM system. For details, see Figure 3 Two-OSC single-fiber bidirectional transmission scenario, Figure 4 Single-OSC single-fiber bidirectional transmission scenario (similar to SFIU), and Figure 5 Single-OSC two-fiber bidirectional transmission scenario (similar to FIU).
The two-OSC single-fiber bidirectional transmission scenario is recommended. In this scenario, both IEEE 1588v2 compensation-free and optical-layer ASON are supported.
In the single-OSC single-fiber bidirectional transmission scenario (similar to SFIU), IEEE 1588v2 compensation-free is supported, but optical-layer ASON is not supported.
In the single-OSC two-fiber bidirectional transmission scenario (similar to FIU), optical-layer ASON is supported, but IEEE 1588v2 is not supported.
Two-OSC single-fiber bidirectional transmission scenario:
Single-OSC single-fiber bidirectional transmission scenario (similar to SFIU):
Single-OSC two-fiber bidirectional transmission scenario (similar to FIU):
Summary
Thanks!
