Filter
Top Products
S/UNI-QUAD
PMC-Sierra, Inc.
PM5349 S/UNI-QUAD
DATASHEET
PMC-971239 ISSUE 6 SATURN USER NETWORK INTERFACE (155-QUAD)
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
38
10.5
Receive Path Overhead Processor (RPOP)
The Receive Path Overhead Processor (RPOP) provides pointer interpretation,
extraction of path overhead, extraction of the synchronous payload envelope, and
path level alarm indication and performance monitoring.
10.5.1
Pointer Interpreter
The Pointer Interpreter interprets the incoming pointer (H1, H2) as specified in
the references. The pointer value is used to determine the location of the path
overhead (the J1 byte) in the incoming STS-3c (STM-1) stream. The algorithm
can be modeled by a finite state machine. 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), e.g., 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. It should be noted that, since the
algorithm only contains transitions based on consecutive indications, this implies
that, for example, non-consecutively received invalid indications do not activate
the transitions to the LOP_state.