COBHAM Sailor 250 FleetBroadband, Training Manual, Page: 23 / 270

13
SAILOR FleetBroadBand
Training Manual
1
The FPS analyses the trends in demand and uses the results
to forecast demand over the next 24 hours and further into the
future. The FPS then periodically issues updated frequency plans
to the GRM. The GRM then applies these plans, reconfi guring the
channels used on the satellite payload and the LRMs to ensure
that capacity is available in beams ahead of peaks in demand. By
anticipating peaks and troughs by pre-confi guring approximately
the correct number of channels to each beam over the course of a
day, satellite capacity can be deployed more quickly with greater
frequency re-use and less congestion.
1.6.1 RNC Recourse Management Entities
The resource management entities, within the RNC, manage the
satellite capacity with a fi ne level of granularity than is visible to the
GRM. Below fi gure illustrates a simplifi ed view of the architecture
of the RNC resource management entities.
Figure 1-24: RNC Recourse Management
In each beam FleetBroadband Terminals and bearers are managed
collectively by an RNC function known as a “bearer control”. A
bearer control manages the bearers in a beam and allocates
capacity to the various connections such as circuit switched calls
and packet data sessions. A single FleetBroadband Terminal may
have one or more active connections. Multiple FleetBroadband
Terminals and their associated connections are concurrently
served by a bearer control. The bearer control will periodically
retune FleetBroadband Terminals between bearers to ensure that
demand is distributed to where there is most unused capacity. If
the load on a bearer control could be supported on fewer satellite
channels it will move FleetBroadband Terminals to concentrate
them on fewer bearers and return the unused channels to the
GRM. FleetBroadband Terminals with ongoing circuit switched
calls are locked to the same bearer for the duration of the call so
both of these load smoothing techniques have to wait until the
call has ended before moving a FleetBroadband Terminal. There
is no restriction on moving a FleetBroadband Terminal with an
IP connection. Forward and return load smoothing is carried out
independently.