T3103 default and opt. values

[punto]

Hello,
please, could someone share some good document with description of timer T3103
for NSN, E*******, Alcatel-Lucent vendors,
default values and values you have in networks.

It would be nice if someone could share a nice document , also ,
with optimization effects after changing value from default to tuned value.

THX a lot to all friends
P

[projtcho2]

Hi my friend,

Find below Siemens explanation and rules:
BSC timer T8, this timer determines the time to receive the
HANDOVER COMPLETE message. T8 is defined as the time that
BSC layer 3 will wait for a handover to complete before releasing the
source channel.
BSCT8 corresponds to T3103 according to GSM.
Timer BSCT8 is started when the BSC sends the HANDOVER COMMAND
message and is normally stopped when the MS has correctly seized the new channel.

BSCT8 should be set to a value:
1 sec. < BSCT8 < Min (TTRAU, TSYNC, 20 sec.)
This results from the following rule:
T3124 + delta < BSCT8 < Min (TTRAU, TSYNC, T_MSRFPCI)

where
T3124: MS internal timer with a fixed value set to 320 ms in case a TCH shall be allocated on the new channel (refer to chapter "References",
[1] GSM 04.08, chapter 11)
delta: Time between generation of the HANDOVER FAILURE message by the MS and the receipt of the message by the BSC on the old channels (secure value: 680 ms)
T_MSRFPCI:BTSE internal timer (20 sec.), hardcoded

[RF engineer]

T3103 is the timer start from handover command and stop in channel release if u have handover signalling you see where they are as for huawei this as default is 1s and i changed for cells where coverage are not ovrlapped to 1.5 found drops reduced because the probability of handover reversion to old channel increase and the only draw back is that in the sametimes two channel will be occupy so if u have cells carry traffic you have to monitor performance of cells and the neighbor

[punto]

As this timer is on BSC side/level, the number of cells affected with different value is on larger scale, and as opposite to smaller scale effect of change of some parameter on couple of cells on just cell level. From past experience I would like to collect as much as possible advices and hints from you guys, before playing with live net and playing with mental happiness of mobile phone users ))) So, pls, share your experience, findings and problems occurred. P

[tukangoptim]

3G also has this timer..

[punto]

Pls, guys check the value of this timer and let me know the value you have in it with vendor referred in reply ... thanks to all P

[Processor]

ALU ---- 16.5

[projtcho2]

Please take care if it's with great value more time the resources will be kept in order to make possible returning to the old channel. Usually in Siemens the value is 4-5 s.