System Mode
You can configure the TimeProvider to operate in one of three mode:
Synchronization Supply Unit (SSU)
Subtending (SUB) as defined by Telcordia GR-378 Section 7
Primary Reference Receiver (PRR) when you connect the Symmetricom GPS Timing Antenna
The distinguishing aspect between modes is defined by the inputs that can be selected as the system reference.
SSU Mode
The SSU Mode is the TimeProvider’s default operating mode. The PRS, INP1, and INP2 signals can be selected as the system reference. The GPS input cannot be selected in this mode, and the INP1 and INP2 inputs cannot be provisioned to receive Composite Clock signals. The method of selecting the system reference is described in the TimeProvider User's Guide.
SUB Mode
The SUB Mode allows the TimeProvider to operate as a Remote shelf. When you provision the unit for the SUB mode, the firmware automatically provisions INP1 and INP2 for CC inputs. These are the only inputs available as system references; you can provision the PRS and GPS inputs for monitoring, but they cannot be selected as system reference. The CC outputs are required to tightly phase-follow the selected CC input reference with minimal filtering; this filtering applies to all output types.
PRR Mode
The PRR Mode requires you to connect the GPS Timing Antenna to the system; this input is the only one available as the system reference. You can provision the INP1, INP2, and PRS inputs for monitoring, but they cannot be selected as system reference. The PRR mode enables the BesTime algorithm to improved Bridging mode operation.
Input Selection Mode:
The Input Selection Mode describes the overall method for selecting a reference input.
AUTO - The TimeProvider decides which input to select (See Input Selection)
FORCED - The selected input has been selected by the user. If this input fails the TimeProvider enters holdover.