General operating mechanisms
1.12 Performance management
1.12.5 Trace management .1 Principles
Call tracing function The Call tracing function is unique in a BSS and allows, on MSC request, to record information related to one or more calls controlled by the BSC.
Trace data storage is activated at BSC level on receipt of the BSSMAP MSC TRACE INVOKE message (MSC Phase II) or the BSSMAP TRACE INVOKE message (MSC Phase I) issued by the MSC. Trace characteristics (type of transfer according to the trace priority, type of trace = basic, handover, radio) are transmitted to the BSC through this message.
Tracing a call ends when the call is no more controlled by the BSC, that is when the call ends or when an outgoing handover is performed.
The BSS Call tracing function is activated by creating a traceControl object.
It is deactivated when the object is locked or deleted.
TheDisplaycommand on that objet allows the user to know if the function is active (unlocked object) and check its characteristics. They can be modified when the traceControl object is locked.
Call path tracing function The Call path tracing function (follow-up of calls using common resources) is unique in a BSS and is controlled by the BSC. It allows to record information related to calls using selected resources in the BSS, such as set of cells, set of TRX/DRXs, set of terrestrial circuits.
During a path tracing follow-up, all calls that enter the observation area are automatically traced by the BSC (in the limits set for each type of trace). For example, if only one terrestrial circuit is observed and a call is established on that circuit when the Call path tracing function is activated, then the call is automatically traced.
Tracing a call ends when the call stops using the traced resources or when the path tracing follow-up stops.
The BSS Call path tracing function is activated by creating a callPathTrace object. It is deactivated when the object is locked or deleted.
TheDisplaycommand on that objet allows the user to know if the function is active (unlocked object) and check its characteristics. They can be modified when the callPathTrace object is locked.
1.12.5.2 Management parameters
Call tracing function A BSS Call tracing function is identified in the OMC-R by a traceControl object which defines the number of the associated BSC and partial record generation conditions such as the following:
• at the expiration of a given period of time
• on occurrence of a given event (the only type of event managed by the BSC is "handover")
• on each occurrence of a given number of "handover" events
• on BSC request only, if the manual of data associated with a traced call crosses a given threshold set by static configuration (8 Kbytes for a priority trace, 20 Kbytes for a non--priority trace), or if the manual of data associated with all traced calls crosses a given threshold set by static configuration (100 Kbytes)
The type of information to collect (basic, handover, radio) is given to the BSC in the trace message issued by the MSC:
Data basic handover radio
Invocation message x x x
BTS Id x x x
TRX Id x x x
TRAU Id
Radio channel information x x x
Request type x x x
End indication x x x
MS power x
BS power x
Timing advance x
MS classmark 1 x x x
MS classmark 2 x x x
MS classmark 3 x x x
BSIC x x x
CIC x x x
Handover result x x x
Handover cause x x x
Data basic handover radio Handover duration
Target Cell List x x
Synchronization information x x x
SCCP connection event
BSSMAP message x
DTAP message x
RR message x
A--bis messages x
Timed A--bis messages
Measurements x
Timed Measurements
Power control x
Timed Power control Record extensions
Additional manufacturer data are recorded in trace messages. They describe the equipment used by the traced call at a given time :
Data for BSC 12000HC basic handover radio
pcm-ts A interface x x x
TCU 2G Id x x x
TDTI A interface x x x
TCB Id x x x
TDTI A-ter x x x
pcm-ts-circuit A-ter interface x x x
DDTI A-ter x x x
BIFP x x x
SICD x x x
TEI-Abis x x x
DDTI A-bis x x x
Data for BSC 12000HC basic handover radio
pcm-ts-circuit A-bis interface x x x
bts-pcm x x x
Data for BSC 3000 basic handover radio
pcm-ts A interface x x x
TCU e3 Id x x x
LSA-TCU A interface x x x
tcu e3 Id x x x
LSA-TCU A-ter x x x
pcm-ts-circuit A- ter interface x x x
LSA-BSC A-ter x x x
TMU x x x
TEI-Abis x x x
LSA-BSC A-bis x x x
pcm-ts-circuit A-bis interface x x x
bts-pcm x x x
Call path tracing function A BSS Call path tracing function is identified in the OMC-R by a callPathTrace object that defines the associated BSC, the resources used (bts, transceiverEquipment, xtp), the end-of-session criteria such as the following:
• at the expiration of a given period of time
• when a given number of radio measurements is recorded (for radio-type data only)
• when the callPathTrace object is locked
and the type of data to collect (basic, handover, radio).
Partial records are only generated on BSC request in that case (see the previous Paragraph).
1.12.5.3 Collecting trace data
For each new traced call, the BSC starts recording the associated data and generates a trace record.
Data are recorded according to their type. The following apply:
• Call tracing function: The type is provided in the message issued by the MSC and is specific to each traced call.
• Call path tracing function: The type is set by the user (parameter of the associated callPathTrace object) and is common to all traced calls.
Either the BSC generates partial records, or it saves all data until the end of the call and then generates complete records.
1.12.5.4 Storing trace records BSC trace record store
• Call tracing data
Priority call trace records are temporarily stored in a circular file on the BSC disks. In normal operating conditions, the records are forwarded to the OMC-R agent as spontaneous messages as soon as they are available and the file is automatically purged. They are stored on the OMC-R in files with the names "/MD/trace_func-tion/os_ftam/<date>/<bsc>/naPTCL_<traceReportNbr>.<log", where:
— <date> - date of trace reception in YYYYMMDD format
— <bsc> - bsc Id
— <traceRepor tNbr> - an auto incremented number of received trace message (initialized with UNIX time of the first received message)
— <logId> - associated log instance
For the BSC 12000HC, non-priority call trace records are stored as files in the :CALLTR: partition on the BSC disks. For the BSC 3000, non-priority call trace records are stored as files in the
/OMU/share/log/OBR_CT/ directory. The names of the files for both the BSC 12000HC and 3000 are formatted as "ydddmmmsrrrrnn", where:
— y = year [0 to 9]
— ddd = day of the year [001 to 365]
— mmm = minute of the day in hexadecimal [000 to 59F]
— s = time stamp of 4 seconds of the minute in hexadecimal [0 to E]
— rrrr = trace reference [0 to 255]
— nn = trace sequence number [0 to 99]
On the OMC-R, the same previous files are named as "/MD/trace_func-tion/os_ftam/<date>/<bsc>/aTCL_<bsc>_<chhmm><mmms.<logId>", where:
— <date> - date in YYYYMMDD format
— <bsc> - bsc Id
— <chhmm> - deltaUTC with preceding "P" or "M"
— <logId> - associated log instance
Once a record is stored, a spontaneous message is sent to the OMC-R agent, indicating that a new data file is available. Data are transferred using FTAM, and under the OMC-R agent control.
• Call path tracing data
Non-priority traces are the only type that is possible for the callPathTrace.
Non-priority traces are always archived. On the BSC 12000HC, non-priority callPathTrace file names are stored in the :CALLPATH:
partition on the BSC disks in a file whose capacity is set by the user (parameter of the associated callPathTrace object).
When the file is full, a spontaneous message is sent to the OMC-R agent, indicating that a new data file is available. Data are transferred using FTAM, and under the OMC-R agent control.
A new file is then open and this file stores the new records of the ongoing traces.
On the BSC 3000, non--priority callPathTrace records are stored as files in the OMU/share/log/OBR_CPT/ directory. The names of the files for both the BSC 12000HC and 3000 are formatted as "ydddmmms", where:
— y - year [0 to 9]
— ddd - day of the year [001 to 365]
— mmm - minute of the day in hexadecimal [000 to 59F]
— s - time stamp of 4 seconds of the minute in hexadecimal [0 to E]
• Special cases
When the BSC operations switch over to the standby chain, ongoing call tracing is stopped (all data are lost, unless they have been recorded in partial records). New calls are automatically traced when the standby chain becomes active.
When the BSC application database is rebuilt, some messages may be lost since the BSC automatically purges all collected messages that have not been transferred once the database is rebuilt.
OMC-R trace record store Each trace record collected by the OMC-R agent is stored on disk. The records are stored for no more than four days (D, D-1, D-2, D-3) by default. This period can be statically modified.
The maximum configurable duration for MD storage is 10 days including today for all hardware configurations.
Directories and trace file naming rules are described in theSection 1.12.6
"OMC-R message store" (page 163).
1.12.5.5 Archiving trace data
Trace data stored before the current day can be backed up and restored on--line.
Trace data archiving is defined in static configuration data (see NTP < 006
>) for a given date. It concerns all the records generated on the given date.