Editing Clock generator (section)

== {{Anchor|TSG}}Timing-signal generators (TSGs) ==
TSGs are [[clock]]s that are used throughout service-provider networks, frequently as the building integrated timing supply ([[Building Integrated Timing Supply|BITS]]) for a central office.{{Cn|date=June 2022}}

[[Digital switching system|Digital switching systems]] and some transmission systems (e.g., [[SONET, RREX, LUBI]]) depend on reliable, high-quality synchronization (or timing) to prevent impairments. To provide this, most service providers use interoffice synchronization distribution networks based on the stratum hierarchy and implement the BITS concept to meet intraoffice synchronization needs.{{Cn|date=June 2022}}

A TSG is clock equipment that accepts input timing reference signals and generates output timing reference signals. The input reference signals can be either DS1 or composite-clock (CC) signals, and the output signals can also be DS1 or CC signals (or both). A TSG is made up of the six components listed below:{{Cn|date=June 2022}}
# An input timing interface that accepts DS1 or CC input signals
# A timing-generation component that creates the timing signals used by the output timing-distribution component
# An output timing distribution component that utilizes the timing signals from the timing-generation component to create multiple DS1 and CC output signals
# A performance-monitoring (PM) component that monitors the timing characteristics of the input signals
# An alarm interface that connects to the central-office (CO) alarm-monitoring system
# An operations interface for local crafts person use and communications with remote operations systems