Which component of a PON includes a downstream optical transmitter and an upstream receiver?

The component of a Passive Optical Network (PON) that includes both a downstream optical transmitter and an upstream receiver is the Optical Line Terminal (OLT). The OLT acts as the central hub of the PON, typically located at the service provider's central office or data center. It manages data transmission to the Optical Network Units (ONUs) at the customer premises.

The downstream optical transmitter in the OLT transmits data to multiple users over fiber optic cables, while the upstream receiver collects data sent back by those users. This dual capability is essential for facilitating the bi-directional communication that PONs are designed to support.

In contrast, the Optical Network Unit (ONU) is positioned at the end user location, receiving downstream signals and transmitting upstream signals but does not have both the transmitter and receiver functionalities integrated within a single component like the OLT does. The Optical Distribution Network (ODN) refers to the physical infrastructure of fibers and splitters that connect the OLT to ONUs, while the optical splitter is used to divide the optical signal into multiple paths toward the ONUs, but it does not have transmitter or receiver capabilities.