RELEASED
PM73122 AAL1GATOR-32
DATASHEET
PMC-1981419
ISSUE 7
32 LINK CES/DBCES AAL1 SAR PROCESSOR
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
173
Table 12 Supported Links
Link
Mapping
Timing Method
Links
DS3
Unchannelized DS3
Floating Payload
2
E1
Byte Synchronous
Floating Payload or
Locked Payload
32
T1
Byte Synchronous
Floating Payload or
Locked Payload
32
11.6.3.1.8
Scaleable Bandwidth Interface Multiplexing Structure
The time division multiplexed bus uses the SONET/SDH virtual tributary structure
to carry T1 links, E1 links. Unchannelized DS3 payloads follow a byte
synchronous structure modeled on the SONET/SDH format.
The SBI structure uses a locked SONET/SDH structure fixing the position of the
TU-3 relative to the STS-3/STM-1. The SBI is also of fixed frequency and
alignment as determined by the reference clock (REFCLK) and frame indicator
signal (C1FP). Frequency deviations are compensated by adjusting the location
of the T1/E1/DS3 channels using floating tributaries as determined by the V5
indicator and payload signals (DV5, AV5, DPL and APL). TVTs also allow for
synchronous operation where SONET/SDH tributary pointers are carried within
the SBI structure in place of the V5 indicator and payload signals (DV5, AV5,
DPL and APL).
Table 13 shows the bus structure for carrying T1, E1, DS3 tributaries in a SDH
STM-1 like format. Up to 84 T1s, 63 E1s, or 3 DS3s are carried within the octets
labeled SPE1, SPE2 and SPE3 in columns 16-270. All other octets are unused
and are of fixed position. The frame signal (C1FP) occurs during the octet
labeled C1 in Row 1 column 7.
The multiplexed links are separated into three Synchronous Payload Envelopes
called SPE1, SPE2 and SPE3. Each envelope carries up to 28 T1s, 21 E1, or a
DS3. SPE1 carries the T1s numbered 1,1 through 1,28, E1s numbered 1,1
through 1,21, or DS3 number 1,1. SPE2 carries T1s numbered 2,1 through 2,28,
E1s numbered 2,1 through 2,21, or DS3 number 2,1. SPE3 carries T1s
numbered 3,1 through 3,28, E1s numbered 3,1 through 3,21, or DS3 number
3,1.