User's Manual Part 2

DSPbR Series – User’s Manual
Document Number 00000.B Page 32/75
Slot allocation architecture;
Slots 1-6 allocated to RFBE’s only.
Slots 9 allocated to RFFE only.
Slots 7 & 8 allocated to either RFFE’s or RFBE’s.
Slot 10 allocated to a DSP module.
Typically slots 1-4 or 5-8 are used for an 8-Ch Internal combiner filter unit, however the combiner unit can fit
across any 4 continuous RFBE slot block.
RFBE modules can be configured such that side “A” is an uplink channel and side “B” is a downlink channel.
When RFBE modules are configured in this way, the use of an internal combiner is not possible.
Alternatively, RFBE modules can be configured with both side “A” and side “B” as uplink or downlink. This
configuration option along with the corresponding slot block allocation permits the fitting of the internal combiner
unit.
Refer to Appendix “A” - Single Sub Rack Frame, DSPbR Slot Architecture – Typical Configurations.
3.6 Internal up link and down link RFBE combining
Internal RFBE output combining of uplink and or downlink channels is optional, however the slot and uplink /
downlink configuration has to be in accordance with the following simple rules.
Rule 1. Both side “A” and side “B” within the RFBE module have to be configured as either uplink or downlink
RFBE boards.
Rule 2. Combined channels must occupy 4 contiguous slots, i.e. slots 1-4, 3-6 or 5-8.
The 8-channel combiner filter unit uses a hybrid coupler technique to cater for combining frequencies that are
adjacent or at any frequency within the allocated 20MHz bandwidth. Isolators and a band pass filter are
incorporated within the combiner unit supporting good transmitter combining engineering practices.
The 8-channel combiner filter unit fits directly into the back of the RFBE modules, effectively replacing the
individual BPF modules at the outputs of the RFBE’s. The N female single output connector is accessible from
the rear of the unit. Caution must be taken when touching the combiner module from the rear when in service
as heat is likely to have been generated through this combining technique.
Both uplink and or downlink output combining is possible within a single sub rack frame.
The 8-Channel internal combiner has a single output and is not tuneable.