Low TCH Utilization but High TCH Block

[callme_eez]

Dear Expert,

Here in my network I have some cells with Low TCH Utilization (below 50%) but High TCH Block (more than 2%). Some justification I made are :
1. Alarm problem that can reduce number of available TCH
2. No alarm but TCH timeslot is faulty (can not be occupied)
3. Burst traffic behavior (this case still need further investigation)

For example in my case there is one cell with 13 TCH Full Rate, Half Rate threshold 50% only 12 attempt in busy hour but have 2 blocking. I don't know why this blocking is happened as I think resources is still enough.

Waiting for open discussion. Thanks :)

[RF engineer]

Dear Expert,

Here in my network I have some cells with Low TCH Utilization (below 50%) but High TCH Block (more than 2%). Some justification I made are :
1. Alarm problem that can reduce number of available TCH
2. No alarm but TCH timeslot is faulty (can not be occupied)
3. Burst traffic behavior (this case still need further investigation)

For example in my case there is one cell with 13 TCH Full Rate, Half Rate threshold 50% only 12 attempt in busy hour but have 2 blocking. I don't know why this blocking is happened as I think resources is still enough.

Waiting for open discussion. Thanks :)

check if u have TRX faulty , AMR is activated.


BR

[callme_eez]

I already check ... no TRX faulty, all timeslot is OK and AMR already activated too :)

[dodotiro]

what vendor do you use ?

if it is Huawei, please check the Abis capacity and PDTCH allocation and payload.

[callme_eez]

what vendor do you use ?

if it is Huawei, please check the Abis capacity and PDTCH allocation and payload.

Yes .. Huawei Vendor and using Flex Abis mode. Only 1 PDTCH TS configured with 30% threshold for dynamic PDCH assigned but can be ignore due to pre-empt. Payload is average too.

I found that there is failure to allocates Abis Resources (TCHF/TCHH), but is this related with Blocking in Radio condition ??

Thanks :)

[mohyedeen_alkousy]

if u have Flex abis mode then U have to check if the defined flex timeslots are enough for all the TRXs in the site

[callme_eez]

if u have Flex abis mode then U have to check if the defined flex timeslots are enough for all the TRXs in the site

I think it's still enough as current Abis Utilization is around 65%. The thing is whether (if) this Abis resources is not enough have relation with rejection on radio part ?

[beniy]

Dear Expert,

Here in my network I have some cells with Low TCH Utilization (below 50%) but High TCH Block (more than 2%). Some justification I made are :
1. Alarm problem that can reduce number of available TCH
2. No alarm but TCH timeslot is faulty (can not be occupied)
3. Burst traffic behavior (this case still need further investigation)

For example in my case there is one cell with 13 TCH Full Rate, Half Rate threshold 50% only 12 attempt in busy hour but have 2 blocking. I don't know why this blocking is happened as I think resources is still enough.

Waiting for open discussion. Thanks :)
Hahaaaaaaaaaaaa
We had same problem check GPRS parameters.
2)check TRX attributes.(Periority-power-Halfrate)
3)check underlaid -overlaid assignment. if you have 2 G900 and 6 G1800 TRXs and put assignment on G900 you will have TCH BLKing ;-)
Add rep ;-)

[callme_eez]

Hahaaaaaaaaaaaa
We had same problem check GPRS parameters.
2)check TRX attributes.(Periority-power-Halfrate)
3)check underlaid -overlaid assignment. if you have 2 G900 and 6 G1800 TRXs and put assignment on G900 you will have TCH BLKing ;-)
Add rep ;-)

Could u please mentioned which GPRS parameters should be check ?

For TRX attributes, Priority and Power is OK and already support halfrate too :)

FYI ... my network is in DCS1800 only

Add Rep Back please :$

[beniy]

Could u please mentioned which GPRS parameters should be check ?

For TRX attributes, Priority and Power is OK and already support halfrate too :)

FYI ... my network is in DCS1800 only

Add Rep Back please :$
what is equipment?
I had same problem and I checked GPRS parameters and saw the traffic of GPRS is very high and parameters set to get more GPRS traffic,(I am just Huawei expert)

[callme_eez]

what is equipment?
I had same problem and I checked GPRS parameters and saw the traffic of GPRS is very high and parameters set to get more GPRS traffic,(I am just Huawei expert)

As I mentioned previously this is Huwei equipment.

Which GPRS parameter ?? could u mention it ?

[Piscean21]

Ask operations team to check for GTMU.

We had similar kind of problem which was resolved after GTMU replacement.


Hope this helps:)

[RF engineer]

I already check ... no TRX faulty, all timeslot is OK and AMR already activated too :)


you need to check the Cells that TCH rate adjust allowed is activated then you should activate intra-cell F-H HO allowed other wise it should be deactivated.

Because this parameter make you fake congestion as ion the TCH congestion formula there is counter (Failed TCH Seizures in TCH Handovers due to Busy TCH (Traffic Channel)] which this be to sucounters H3023A: CELL_INTRACELL_HO_FAIL_TCHF_TCHH
H3023B: CELL_INTRACELL_HO_FAIL_TCHH_TCHF

when MS call on full rate channel and make HO to cell which have traffic and no Full rate channel only half rate is exist therefore MS need to make intra-cell HO .

BR

[callme_eez]

Ask operations team to check for GTMU.

We had similar kind of problem which was resolved after GTMU replacement.


Hope this helps:)

Thank for your advise. Is there any alarm or something that can be used for justification that GTMU is fault and can be escalated to Operation team for further checking ? Thanks.


you need to check the Cells that TCH rate adjust allowed is activated then you should activate intra-cell F-H HO allowed other wise it should be deactivated.

Because this parameter make you fake congestion as ion the TCH congestion formula there is counter (Failed TCH Seizures in TCH Handovers due to Busy TCH (Traffic Channel)] which this be to sucounters H3023A: CELL_INTRACELL_HO_FAIL_TCHF_TCHH
H3023B: CELL_INTRACELL_HO_FAIL_TCHH_TCHF

when MS call on full rate channel and make HO to cell which have traffic and no Full rate channel only half rate is exist therefore MS need to make intra-cell HO .

BR

Thanks. For both TCH Rate Adjust Allow and Intra-Cell F-H HO Allowed is already activated. Later I will query those counter to check failed in FR-HR conversion. Thanks.

[callme_eez]

I checked again my TCH Block formula, and it's using K3011A which is same with CA312. When I breakdown this counter, mostly is due to :
A312A = Failed Assignments (First Assignment, Channel Unavailable in Assignment Procedure)

could someone help me to give brief description about this counter is pure due to channel or maybe any other else ? Thanks.

[Piscean21]

I checked again my TCH Block formula, and it's using K3011A which is same with CA312. When I breakdown this counter, mostly is due to :
A312A = Failed Assignments (First Assignment, Channel Unavailable in Assignment Procedure)

could someone help me to give brief description about this counter is pure due to channel or maybe any other else ? Thanks.


You should check whether on all TRXs assignments are almost equal or not.

I suspect on some of the TRXs there will be no assignment at all

[beniy]

As I mentioned previously this is Huwei equipment.

Which GPRS parameter ?? could u mention it ?
Hi ,
sorry for delay,
your site is flex.
right click on youe site, choose idle timeslot and make it 0.
your problem will resolve 100% ;-)
it will improve both CS and PS kpi.
enjoy