PXB4221EV34GXP Lantiq, PXB4221EV34GXP Datasheet - Page 281

• Manufacturer Part Number: PXB4221EV34GXP
• Manufacturer: Lantiq

Specifications of PXB4221EV34GXP

• Data Rate: 2.048Mbps
• Number Of Channels: 1
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

12.4
ITU-T recommendation G.704 [24] defines Channel Associated Signalling (CAS) for
interfaces at 2048 kbit/s (E1) and 1544 kbit/s (DS1) interfaces carrying 64 kbit/s
channels. The mapping of E1 or DS1 multiframes containing CAS into ATM cells is
defined in the ATM-Forum “Circuit Emulation Services Specification” [10].
In case of E1 and DS1 circuit emulation, the user information carried via AAL1 consists
of a stream of payload substructures followed by an optional signalling substructure.
Each payload and signalling substructure corresponds to one E1 multiframe / DS1
extended superframe. The payload substructure contains the channel slots and the
optional signalling substructure contains the signalling bits associated with the channels.
The following section gives an overview on this topic.
12.4.1
An E1 multiframe comprises 16 consecutive frames. These are numbered from 0 to15.
The multiframe alignement signal is 0000 and occupies digit time slots 1 to 4 of 64 kbit/
s channel time slot 16 in frame 0.
When 64 kbit/s channel time slot 16 is used for channel-associated signalling, the 64
kbit/s capacity is sub-multiplexed into lower-rate signalling channels using the
multiframe alignement signal as a reference.
Details of the bit allocation are given in
Table 54
E1 Multiframe
Frame 0 (CasBeginFrame)
Frame 1
Frame 2
...
Frame 15
Data Sheet
x = spare bit, to be set to 1 if not used
y = Bit used for alarm indication to the remote end. In undisturbed operation, set to 0; in alarm condition, set to 1.
Channel Associated Signalling
E1
Bit allocation of E1 time slot 16 for CAS
Table 54
281
PXB 4219E, PXB 4220E, PXB 4221E
Bit allocation of time slot 16
0000
abcd channel 1
abcd channel 2
...
abcd channel 15
xyxx
abcd channel 16
abcd channel 17
...
abcd channel 30
IWE8, V3.4
Appendix
2003-01-20