
S/UNI-JET Data Sheet
Released
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
264
Figure 11 E1 PLCP Frame Format
A1
A2
P9
Z4
A1
A2
P8
Z3
A1
A2
P7
Z2
A1
A2
P6
Z1
A1
A2
P5
F1
A1
A2
P4
B1
A1
A2
P3
G1
A1
A2
P2
M2
A1
A2
P1
M1
A1
A2
P0
C1
ATM Cell
ATM Cell
ATM Cell
ATM Cell
ATM Cell
ATM Cell
ATM Cell
ATM Cell
ATM Cell
ATM Cell
PLCP
Frame Rate
2.375 ms
53 octets
POH
Framing
(3 octets)
The E1 PLCP frame provides the transmission of 10 ATM cells every 2.375 ms. Thirty of the
thirty-two available E1 channels are used for transporting the PLCP frame. The remaining two
channels are reserved for E1 framing and signaling functions. The PLCP frame is octet aligned to
the channel boundaries in the E1 frame. The PLCP frame is aligned to the 125 μs E1 frame (the
A1 octet of the first row of the PLCP frame is inserted in timeslot 1 of the E1 frame).
13.3.1
PLCP Path Overhead Octet Processing
Table 34 PLCP Overhead Processing
Overhead Field
Transmit Operation
Receive Operation
A1, A2:
Frame Alignment
Pattern
Inserts the PLCP frame alignment
pattern (F628H)
Searches the receive stream for the PLCP
frame alignment pattern. When the pattern has
been detected for two consecutive rows, along
with two valid, and sequential path overhead
identifier octets, the S/UNI-JET declares in-
frame.
Note: The ATM cell boundaries are implicitly
known when the PLCP frame is located, thus
cell delineation is accomplished by locating the
PLCP frame. When errors are detected in both
octets in a single row, or when errors are
detected in two consecutive path overhead
identifier octets, the S/UNI-JET declares an
OOF defect. The LOF defect is an integrated
version of the OOF defect state.
PO-P11:
Path Overhead
Identifier
Inserts the path overhead identifier
codes in accordance with the
PLCP frame alignment. See Table
35.
Identifies the PLCP path overhead bytes by
monitoring the sequence of the POI bytes.
Z1-Z6:
These octets are unused and are
These octets are ignored and are extracted on