PS User Inactive Detecting Timer

[sofianonline]

Hi All,

Does anyone know the parameter setting for T1 and T2 for services in Huawei. This parameter were used to detecting inactive PS user. If no data transfer longer than this T1, PDCP will request RRC layer to release this RAB. If not released until T2, PDCP will resend again.

The problem is for internet service like Blackberry, high setting could make PS data congestion.
Huawei recommended this timer to be set mostly at 20s for kind of services.
I think this value is too long.. Do you have any idea???

[Budaxbaix]

We can set to 10, here is sample in our network:
PSINACTTMRFORCON 20
PROTECTTMRFORCON 20
PSINACTTMRFORSTR 20
PROTECTTMRFORSTR 20
PSINACTTMRFORINT 10
PROTECTTMRFORINT 10
PSINACTTMRFORBAC 10
PROTECTTMRFORBAC 10
PSINACTTMRFORIMSSIG 20
PROTECTTMRFORIMSSIG 20

[gprastomo]

20 s is too fast, and it will generate ps data reconnection which can load the RNC and signalling.
And if you make it fast then you need to adjust hs to fach to pch to be fast otherwise it ill get release during hs or fach which is not good for user perception.
What congestion of PS Data you have ?
Coz in NSN usually they set to 10-15 minutes and there is no issue, and i make 120 s in huawei network, and no issue.

Usually it will lead to IuB or IuPS congestion, since the reservation is still there so we need to mmodify the IuB/IuPS bandwidth reservation tobe smaller than 40%.

br

[boring]

it is very tricky, to set inactivity timers correctly.

gprastomo what you describe is completetly valid for no-smartphone users...

in contrast, on average smartphone after 10 sec they sent an RRC signalling release request (fast dormancy feature), so 20 sec will not help, and consequently for smartphone you need something smaller... (in the region of 10 sec)

[jayk]

We have set values to 30 minutes for T1 and 20 s for T2. Huawei Default value are correct in case when all RRC states are not enabled. Once you enable all four RRC states Huawei suggests to increase the timer.

[sofianonline]

20 s is too fast, and it will generate ps data reconnection which can load the RNC and signalling.
And if you make it fast then you need to adjust hs to fach to pch to be fast otherwise it ill get release during hs or fach which is not good for user perception.
What congestion of PS Data you have ?
Coz in NSN usually they set to 10-15 minutes and there is no issue, and i make 120 s in huawei network, and no issue.

Usually it will lead to IuB or IuPS congestion, since the reservation is still there so we need to mmodify the IuB/IuPS bandwidth reservation tobe smaller than 40%.

br

Thanks Pak Gito , actually we set using Huawei recommended value (20s) and no issue.
Just taken info from RIM that in UK they faced a problem with this setting and got congestion.
I don't know what kind of congestion, but according to the definition, the RAB is still not release until this timer expired.

But setting with low value will also make signaling higher..
So, what is the recommendation value???

I got the documents, for blackberry its about 5-10s
http://www.finetopix.com/showthread....=Fast+Dormancy

[gprastomo]

Hi Pak Sofian,

I think the congestion is on the PCH load, since increasing the PS inact timer will extend the ue in cell PCH longer, when you have many smartphone (like BB, Iph, Andro etc) with its active PS connection, many of them will camp to cell PCH.

But actually when the user camp to PCH the CS paging will come at cell level instead of LAC level, so this will reduce the paging load also, which one is the most affected will be depends on your traffic profile, CS traffic or PS traffic, if you have high PS traffic so extending inact timer will increase the paging load.

So to overcome this PCH load issue, you need to split the LAC to reduce the paging load.

Actually about the RAB is not release after this timer expired will depends on the type of the modem. As per some vendor investigation that some of the modem that stay in PCH (during PS active) and got release due to inactivity, this modem will looks like hang, it will stay PDP connect but you cant browse, some time you need to unplug n plug the modem, and some time you need to manually disconnect then connect again.

But for BB, i think it will automatic reconnect (CMIIW).

So too fast inactivity timer you will have connect no browsing issue (some time you cant move from PCH to fach to hs) you need to reconnect.

So about the best setting, as i read from some docs (Qualcomm use 2-5 minutes), NSN about 10-15 minutes, i dont know e///.
But you need to make sure that IuPS reservation should be less than 40% to avoid congestion

[nupong]

I'm also confused about T1 whether trigger Cell_DCH to Idle and as seen on Huawei is 20s on default but D2F state transition timer is 5s, even included timer to trigger, pending time and state trans coeff. they should be shorter than 20s


Howe can T1 timer would expire before state change to CELL_FACH? I'm not sure whether 20s is valid only if we do not activate FACH/PCH.

Some Huawei engineer told me that it would use T1 from FACH to Idle instead , does it true?

If anyone can share useful document rather than what's HEDEX said would be appreciated

[topoffenders]

Guys!

inactivity timer is best to be in 30 secs. but again the fast dormancy implementation id depending to the Ue implementation as well.
handset like Samsung, go to idle quickly to safe battery.