7741 alarm

[harrypotter]

Dear Expert,

Once again Im asking for help.

7741**, MEAN HOLDING TIME ABOVE DEFINED THRESHOLD"

[khelvin]

7741 MEAN HOLDING TIME ABOVE DEFINED THRESHOLD
Meaning

The mean holding time on the channel specified exceeds the
operator-defined threshold during the measurement period.
The alarm is used to supervise the functioning of the traffic and
signalling channels. It reveals unreleased calls.

Supplementary information fields

1 subchannel identification
00 - 01: TCH/H subchannel
F0 : TCH/F subchannel
C0 - C7: SDCCH subchannel

2 mean holding time on the channel in minutes

3 number of seizures on the channel during the measurement period

4 shortest seizure on the channel during the measurement period
in seconds

Instructions

Take E00 service terminal extension into use in the working MCMU
with the following command:
ZLE:<char>,E00_BXSX
Note that you need to check which MCMU is in the working state with the
command ZUSI:COMP;

Use the E00 service terminal extension command S to find out whether
the channel seizure that caused the alarm is a real call or an
unreleased channel.
Give the following command to the working MCMU unit:
Z<char>S:<BTS_id>,0,B,20;
Note that the parameter BTS_ID is given in hexadecimal format.

RRMPRB states are on CH STA column:
0=DISC 10=IDLE 20=BUSY FF=CBCH

ABIPRB states are on the last column of the output row:
0 = blocked
1 = free
2 = signalling
3 = conversation
4 = not in use
5 = CBCH

Compare the channel state in RRM and ABI to determine whether
the channel is unused but unreleased.

In the case of an unreleased channel, if it is a traffic channel,
restore the channel by first locking it out of use and then unlocking
it (TCH lock/unlock). Use the MML command ERS and give the TRX and
the channel as parameters.

ZERS:<BTS>,<TRX>,<CH>; lock
ZERS:<BTS>,<TRX>,<CH>:U; unlock

If it is a signalling channel, restore the channel by locking and then
unlocking the whole TRX (TRX lock/unlock). Use the MML command ERS
and give the TRX as a parameter.

Check that the parameters affecting the alarm are reasonable.
MML command EEO outputs the radio network supervision parameter values,
EEN command modifies the parameter values.

Parameters, with their default values, affecting the alarm:
ZEEN:MAXHTT= maximum mean holding time for TCH (120 min)
MAXHTS= maximum mean holding time for SDCCH (30 min)
PRDMHT= length of TCH supervision measurement (240 min)
PRDMHS= length of SDCCH supervision measurement (60 min)

Cancelling

If the alarm does not require user actions, you can cancel it with
the MML command EOR.

The system cancels the alarm when you lock and unlock the object in
question, or, if the alarm requires no user actions, the system cancels
the alarm at the end of the measurement period during which the channel
that caused the alarm is allocated/ released normally.