Comtech EF Data SLM-7650 Installation And Operation Manual page 117

SLM-7650 Satellite Modem
Theory of Operation
EXAMPLE 1 - includes a factor of two to allow the buffer to start in the center and then
drift in either direction. This will allow the buffer to start at any time and at any satellite
position in the figure eight pattern. The buffer size must be increased to lengthen the
number of days between slips.
EXAMPLE 2 - shows a MASTER/SLAVE link and will include a factor of two to allow
the buffer to start in the center plus an additional factor of two to account for the passage
of the timing signal twice through the satellite. The actual buffer size may be larger for
primary framed data like T1, T2, E1, or E2. Framed signals require the buffer size to be
an integer multiple of the frame length of the data. Setting the buffer size to a multiple of
the frame length will decrease the need for the user equipment to re-acquire frame
synchronization. If a complete frame or group of frames is missing because of a buffer
slip then the user equipment will, most likely, maintain synchronization.
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MN/SLM7650.IOM