Transmission Interface Handling DS1 1544 kbit/s
AIS Generation
•
When entering one of the alarm states LOF, LOS or AIS at PCM-
A input, AIS is transmitted on PCM-B output. AIS is transmitted
until the alarm state is left
•
When entering loop mode (Line loopback or Payload loopback) at
PCM-A input, AIS is transmitted on PCM-B output, presuming
that PCM-B is not in loop mode.
AIS is transmitted until the loop mode on PCM-A is left.
•
When entering and leaving alarm states, the alarm filtering time is
used (AFT).
•
When entering and leaving loop modes, AFT is not used.
33.3.8
CSU ANSI
For an RBS configured for CSU according to ANSI, the function is
initiated during restart of the CMRU. The parameter FDL_use in RBS
DB is used to control the configuration.
For an RBS not configured for CSU according to ANSI, the function is
initiated when the parameter FDL_use in RBS DB is set to indicate
CSU ANSI.
The function includes CSU Functionality by use of ANSI bit-patterned
messages and loopback commands on the ESF Data Link (DL, message
bit m). In this function, DL is referred to as Facility Data Link (FDL).
The commands for Payload Loop Back (PLB), Line Loop Back (LLB),
and Universal command deactivate are supported. The commands are
used to enable and disable loops within the T1 interface. A received
AIS will also disable loops within the T1 interface.
General
•
Detection of ANSI bit-patterned messages, received on the FDL,
supporting line loopback, payload loopback, and universal
loopback deactivate command is supported.
The bit-patterned messages are two-byte words starting with one
byte with all ones, followed by a unique byte (command) for each
message type. The messages and loops are handled in accordance
with ANSI T1.403 section 9.3 (1995).
•
Information received on Facility Data Link (FDL) for PCM-A
will make an action on PCM-A only. Information received on
FDL for PCM-B will make an action on PCM-B only.
•
The loop settings will be released at reset of the RBS.
•
The code words for universal loopback deactivate, line loopback
deactivate, and payload loopback deactivate will be sent on PCM-
A and PCM-B after the function Multidrop Bypass has
terminated. First 20 universal loopback deactivate code words are
sent, then 20 LLB deactivate code words, and finally 20 PLB
deactivate code words are sent.
EN/LZT 123 2697
R5A
1998-08-13
211 (306)
© Ericsson Radio Systems AB
— All Rights Reserved —
