US Patent 7583898 Signal-detect-based ranging technique for burst-mode optical systems

In a passive optical network (PON), a burst-mode receiver of an optical line terminator (OLT) is initialized during an initialization phase, such as ranging, by asserting one or more reset signals in response to detecting the presence of a packet signal. For example, after the OLT transmits an initialization message, such as a ranging grant, to an optical network unit (ONU), it asserts one or more reset signals when it detects the presence of a packet signal received from the ONU in response.