Synchronous network

In telecommunication, a synchronous network is a network in which clocks are controlled to run, ideally, at identical rates, or at the same mean rate with a fixed relative phase displacement, within a specified limited range.

Ideally, the clocks are synchronous, but they may be mesochronous in practice. By common usage, such mesochronous networks are frequently described as synchronous.

Source: from Federal Standard 1037C and from MIL-STD-188