VeEX FX120, Руководство пользователя

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Pre
-
assigned delay (PrD)
: The requisite delay that all the ONUs on the PON are required to use prior to completion of the ranging
phase of the activation process.
Quiet window : A time interval during which the OLT suppresses all the bandwidth allocations to the in-service ONUs in order to
avoid collisions between their upstream transmissions and the transmission bursts from the ONUs that have just joined the PON and
are undergoing the activation process.
Ranging : A procedure of measuring the logical distance between the OLT and each of its subtending ONUs with the objective to
accurately time the individual ONU upstream transmission bursts so that these bursts arrive at the OLT in a collision-free sequential
fashion and the upstream overhead, which is required to ensure burst detection and delineation, is minimal. Ranging is performed
during the
ONU activation and may be performed while the ONU is in service.
Requisite delay : A general term denoting the total extra delay the OLT may require an ONU to apply to the upstream transmission
beyond the ONU's regular response time. The purpose of the requisite delay is to compensate for variation of propagation and
processing delays of individual ONUs, and to avoid or reduce the probability of collisions between upstream transmissions.
Status reporting DBA (SR-DBA) : A method of dynamic bandwidth assignment that infers the dynamic activity status of the traffic-
bearing entities within optical network units (ONUs) based on the explicit buffer occupancy reports communicated over the
embedded OAM channel.
Traffic-monitoring DBA (TM-DBA) : A method of dynamic bandwidth assignment that infers the dynamic activity status of the traffic-
bearing entities within optical network units (ONUs) based on the observation of the idle GEM frame transmissions in place of
granted upstream bandwidth allocations.
Transmission container ( T-CONT) : A traffic-bearing object within an ONU that represents a group of logical connections, is
managed via the ONU management and control channel (OMCC), and is treated as a single entity for the purpose of upstream
bandwidth assignment on the PON.
U-plane : A plane of the xPON protocol suite that handles user data in a xPON system. U-Plane provides communication between
GEM clients.
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