
PM5317 SPECTRA-9953 Telecom Standard Product Data Sheet
Release
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2000741, Issue 5
95
14.7 Bit Error Monitor (SBER)
The SBER provides two independent bit error rate monitoring circuits (BERM block). They are
used to monitor line bit error rate indicator (B2). One BERM block is dedicated to monitor the
Signal Degrade (SD) alarm and the other BERM block dedicated to monitor the Signal Fail (SF)
alarm. These alarms can then be used to control system level features such as Automatic
Protection Switching (APS).
The BERM block uses a sliding window-based algorithm. This algorithm provides a much
superior performance for detection, clearing and false detection than a simple jumping-window
(resetable counter being polled at a regular interval) algorithm.
14.8 Receive High Order Path Processor (RHPP)
The Receive High Order Path Processor (RHPP) provides pointer interpretation, extraction of
path overhead, extraction of the SPE (virtual container), and path level alarm and performance
monitoring.
14.8.1
Pointer Interpreter
The pointer interpreter extracts and validates the H1 and H2 bytes in order to identify the
location of the path overhead byte (J1) and all the SPEs of the constituent STS-
1/3c/12c/48c/192c (VC3/4/4-4c/4-16c/4-64c) payloads. The pointer interpreter is a time
multiplexed finite state machine that can process any mix of STS-1/3c/12c/(Nx12)c/
48c/192c (AU3/4/4-4c/4-16c/4-64c) pointers. Within the pointer interpretation algorithm, three
states are defined as shown below:
NORM_state (NORM)
AIS_state (AIS)
LOP_state (LOP)
The transition between states will be consecutive events (indications), for example, three
consecutive AIS indications to go from the NORM_state to the AIS_state. The kind and
number of consecutive indications activating a transition is chosen such that the behavior is
stable and insensitive to low BER. The only transition on a single event is the one from the
AIS_state to the NORM_state after receiving a NDF enabled with a valid pointer value. Please
note, since the algorithm only contains transitions based on consecutive indications, it is implied
that, for example, non-consecutively received invalid indications do not activate the transitions
to the LOP_state.