User Manual

ADCP-75-192 • Issue D • October 2005 • Section 3: Network and System Installation and Setup
Page 3-11
 2005, ADC Telecommunications, Inc.
6.3.2 Pathtrace Forward Transmission
Though the BIM, HDC(s), and FSC all create the pathtrace string and report it in their MIB’s,
the FSC is the originator of the pathtrace string in the forward path of the system. The FSC
HCP writes the pathtrace string to its FPGA, which transmits the pathtrace string through all
eight (8) of its simulcasted outputs. Therefore, the pathtrace string will be routed to all RAN’s
belonging to this tenant.
6.3.3 Pathtrace Forward Reception
In the forward path, the SIF modules in the Hub that are connected to the FSC outputs, as well
as the SIF’s in the simulcasted RANs, simply pass-through the pathtrace strings from their
inputs to their outputs. In addition, the SIF HCP’s report the passed-through pathtrace strings
in the SIF MIB for use by tenant processing and other higher-level processes, as described in
Chapter 6.
In each of the simulcasted RAN’s, the RUC module receives the pathtrace string into its FPGA
from one of its two DIF input connections. The RUC HCP then reports the received pathtrace
strings in its MIB for use by tenant processing and other higher-level processes, as described in
Chapter 6.
6.3.4 Pathtrace Reverse Transmission
The RDC is the originator of the pathtrace string in the reverse paths of the system. However, it
is desirable to maintain continuity between the forward and reverse pathtrace strings. To manage
this, the Pathtrace Process that runs in the RAN CPUs is responsible for reading pathtrace strings
from the RUC MIB, parsing out the Tenant ID sub-strings from the pathtrace strings, and writing
the Tenant IDs into the MIB’s of the RDC’s that are associated with the RUC’s.
The RDC HCP creates two new pathtrace strings (primary/diversity) starting with the Tenant
ID that was provided in its MIB by the Pathtrace Process. The RDC HCP appends its own
CPU IP Address to the pathtrace strings, and then appends the primary/diversity flags ("P" or
"D"). Finally, the RDC process writes the pathtrace strings to its FPGA, which transmits the
pathtrace strings out its two outputs (primary/diversity). The pathtrace strings are then
transmitted back to the Hub reverse modules belonging to this tenant.
6.3.5 Pathtrace Reverse Reception
In the reverse path, the SIF modules in the RAN’s that are connected to the RDC outputs, as well
as the SIF’s in the Hub, simply pass-through the pathtrace strings from their inputs to their
outputs. In addition, the SIF HCP’s report the passed-through pathtrace strings in the SIF MIB
for use by tenant processing and other higher-level processes, as described in Chapter 6.
In the Hub, the RSC module receives the pathtrace strings from several RDC’s into its FPGA
from its DIF input connection. The RSC HCP reports the received input pathtrace strings in its
MIB for use by higher-level processes, as described in sections below. The RSC has the added
responsibility of determining the "majority inputs" to determine the most-prevalent input