PM5366-PI PMC-Sierra, Inc., PM5366-PI Datasheet - Page 86

• Manufacturer Part Number: PM5366-PI
• Description: HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER AND M13 MULTIPLEXER
• Manufacturer: PMC-Sierra, Inc.

PRELIMINARY
DATASHEET
PMC-2010672
9.7 T1/E1 Receive and Transmit Digital Jitter Attenuators
PROPRIETARY AND CONFIDENTIAL
The TEMAP-84 contains two separate jitter attenuators, one between the receive
demultiplexed or demapped T1 or E1 link and the ingress interface and the other
between the egress interface and the transmit T1 or E1 link to be multiplexed
into DS3 or mapped into SONET/SDH. Each jitter attenuator receives jittered
data and stores the stream in a FIFO timed to the associated clock. The jitter
attenuated data emerges from the FIFO timed to the jitter attenuated clock. In
the receive jitter attenuator, the jitter attenuated clock is referenced to the
demultiplexed or demapped tributary receive clock. In the transmit jitter
attenuator, the jitter attenuated transmit tributary clock feeding the M13
multiplexer or SONET/SDH mapper may be referenced to either the data stream,
the CTCLK primary input, or the tributary receive clock.
Jitter Characteristics
The jitter attenuators provide excellent jitter tolerance and jitter attenuation while
generating minimal residual jitter. In T1 mode, each jitter attenuator can
accommodate up to 48 UIpp of input jitter at jitter frequencies above 4 Hz. For
jitter frequencies below 4 Hz, more correctly called wander, the tolerance
increases 20 dB per decade. In E1 mode each jitter attenuator can
accommodate up to 48 UIpp of input jitter at jitter frequencies above 5 Hz. For
jitter frequencies below 5 Hz, more correctly called wander, the tolerance
increases 20 dB per decade. In most applications, each jitter attenuator will limit
jitter tolerance at lower jitter frequencies only. The jitter attenuator meet the
stringent low frequency jitter tolerance requirements of AT&T TR 62411 and ITU-
T Recommendation G.823, and thus allow compliance with these standards and
the other less stringent jitter tolerance standards cited in the references.
The jitter attenuators exhibit negligible jitter gain for jitter frequencies below 3.4
Hz, and attenuates jitter at frequencies above 3.4 Hz by 20 dB per decade in T1
mode. It exhibits negligible jitter gain for jitter frequencies below 5 Hz, and
attenuates jitter at frequencies above 5 Hz by 20 dB per decade in E1 mode. In
most applications the jitter attenuators will determine jitter attenuation for higher
jitter frequencies only. Wander, below 10 Hz for example, will essentially be
passed unattenuated through the jitter attenuators. Jitter, above 10 Hz for
example, will be attenuated as specified, however, outgoing jitter may be
dominated by the waiting time jitter introduced by the multiplexing into DS3 or
mapping into SBI or SONET/SDH. The jitter attenuator allows the implied T1
jitter attenuation requirements for a TE or NT1 given in ANSI Standard T1.408,
and the implied jitter attenuation requirements for a type II customer interface
given in ANSI T1.403 to be met. The jitter attenuator meets the E1 jitter
ISSUE 1
74
HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER
AND M13 MULTIPLEXER
PM5366 TEMAP-84