Comtech EF Data SLM-5650A Vipersat Parameter Editor - Manual (Page 26)

Vipersat
2-10 SLM-5650A Parameter Editor User Guide
• Entry Channel - Entry Channel Mode provides an immediate acquisition
into an SCPC channel upon Remote burst registration.
Note: If the Hub STDMA mode is GIR (Guaranteed Information Rate) or Entry
Channel, normal load switching is automatically disabled. In GIR mode,
the Remote is switched to SCPC as soon as the GIR threshold is
reached, if there is a switch rate defined. In Entry Channel Mode, the
Remote is switched to SCPC as soon as the Hub receives the first trans-
mission from the Remote.
The bandwidth allocation method that is selected will determine which of the
associated parameters are available and applicable.
Fixed
In the Fixed mode, all Remotes have the same slot size regardless of type of
traffic or load. No calculations are made to actively change slot size when oper-
ating in this mode.
Fixed mode minimizes the amount of jitter between Remote transmission times,
and is useful for tuning STDMA as well as for troubleshooting purposes.
Dynamic Slot
In the Dynamic Slot mode, the slot size for each Remote is computed based on
the time (at the current data rate) needed to transmit all the Bytes in Queue. If
the result is less than the minimum slot size or more than the maximum slot
size, the slot is adjusted accordingly.
This mode allows the Burst Controller to provide additional slot time in the
cycle to Remotes with higher traffic demands, increasing throughput and allevi-
ating congestion.
Dynamic Cycle
In the Dynamic Cycle bandwidth allocation method, available bandwidth is
allocated to Remotes proportionally based on their current bandwidth needs.
The bandwidth requirements are determined by the number of bytes in queue
for each Remote divided by the total number of bytes in queue for all Remotes
to determine the percentage of bandwidth to allocate for each Remote.
This mode provides improved efficiency of STDMA due to faster cycle times
during periods of light traffic demands, thus providing minimum latency for the
current load.
NOTE