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started whenever a Transfer Frame is transmitted or retransmitted. If an acknowledgement is
seen for the Transfer Frame, and no subsequent Transfer Frame has been transmitted, then
the Timer shall be cancelled. If the Timer expires and the Transmission_Count has not
reached the Transmission_Limit (see 184.108.40.206), it shall cause an event which initiates
recovery action in the FOP-1 state machine.
If the Timer expires and the
Transmission_Count has reached the Transmission_Limit, an Alert [T1] shall be generated.
The Timer shall not be used when a Type-BD Transfer Frame is transmitted.
The value to which the Timer is set when it is started or restarted is referred to as
‘T1_Initial’, and may be changed using the ‘Set T1_Initial’ Directive.
220.127.116.11 Normal Operation For normal operation, the smallest value of T1_Initial shall be the sum of the following
delays for a given Virtual Channel:
a) processing time of the procedures and layers below FOP-1 at the sending end;
b) time required to transmit a maximum-length Transfer Frame, including the bits
needed for the Communications Link Transmission Unit (CLTU) and coding, as a
serial bit stream;
c) propagation time from the sending end to the receiving end (one-way light time,
including relay satellite path);
d) processing time of the procedures and layers below FARM-1 at the receiving end;
e) worst-case time required to sample and encode FARM-1 status data as a CLCW;
f) worst-case time required to send out the CLCW in the data structure used in the
opposite direction; CCSDS 232.1-B-2 Page 5-5 September 2010 RECOMMENDED STANDARD FOR COMMUNICATIONS OPERATION PROCEDURE-1 g) propagation time in the opposite direction (one-way light time, including relay
h) processing time to extract the CLCW from the data structure received in the opposite
direction and to deliver it to FOP-1 at the sending end.
NOTE – Considering the dynamic nature of the multiplexing procedures performed by the
Lower Procedures, it may not be possible to ex...
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- Spring '14