How far can the IDM-MINI 20Km single-fiber PCM multiplexer transmit? How is the optical path calculated?

When the IDM-MINI 20Km single-fiber PCM multiplexer runs over an optical fiber channel, its transmission distance is 20Km under single-mode single-fiber conditions, and a long-distance optical module can be optionally installed for fiber transmission over longer distances. Whether the optical path can run the full 20Km is verified with an optical power budget: the transmit optical power of the device is -3 to -11 dBm and the receiver sensitivity is better than -36 dBm, and the difference between the two is the loss margin available to the link, from which the attenuation per kilometer of optical fiber, the connector loss and the patch cord loss are deducted item by item. If the calculated result is close to the lower limit of the margin, a more sensitive long-distance optical module can be used instead. Over an E1 channel, the transmission distance is determined by the 2M dedicated line, microwave or DDN transmission system being accessed.