The principle of Single Wavelength BiDi Transceiver

The single wavelength, bi-directional(SWBiDi) transceiver uses one fiber and one wavelength for a simultaneous communication in both directions. It can be widely used in the optical transport networks, access networks, wireless backhaul networks, and private transmission networks since it can save in the capital expenditure and the operational expenditure.

OSP: Outside Plant; are very close to each other, e.g. 1550.1nm and 1550.2nm.

Fig.1 The principle of SWBiDi

Comparison of various transmission technologies

Duplex transceiver uses two fibers, one for upstream, the other for downstream. The cost is high.

Two wavelengths BiDi transceiver uses one fiber, but two wavelengths for a simultaneous communication in both directions. Transceivers at two ends have to be different, which increases the capital and operational cost. In addition, in a WDM-BiDi system, each channel cannot have a 100% dedicated bandwidth for both directions simultaneously since all the subscribers must share a common wavelength in one direction.

SWBiDi transceiver uses one fiber and one wavelength for a simultaneous communication in both directions. All the transceivers are identical. The cost is low.

Table 1 Comparison of various transmission technologies

Note.1: If use APC connector, Return Loss can be mitigated, and the transmission distance can be longer than 80km.

Examples of SWBiDi applications

The data rate of SWBiDi transceiver can be from 155Mb/s to 10Gb/s. The transmission distance can be from 2km to 40km. If use APC connector, the distance can be longer than 80km.

Fig.2 WDM SWBiDi