TBF assignment success rate

[usama0795]

Hey experts another query....network i m analyzing i observed that EDGE TBF Assignment Success Rate UL is greatly degraded when compared to GPRS TBF Assignment Success Rate UL and cause being no response from MS which are fairly high for EDGE and not that high fro GPRS......as MS doesnot respond with a valid RLC block when a polling request is sent......i have specified changing inital coding scheme from MCS2 to MCS1 (initail coding scheme for GPRS is CS2) but with no effect power control settings are same for both EDGE and GPRS........looking for a reason rep would be added for a correct reply. Thanks......

[ghamiz]

Hey experts another query....network i m analyzing i observed that EDGE TBF Assignment Success Rate UL is greatly degraded when compared to GPRS TBF Assignment Success Rate UL and cause being no response from MS which are fairly high for EDGE and not that high fro GPRS......as MS doesnot respond with a valid RLC block when a polling request is sent......i have specified changing inital coding scheme from MCS2 to MCS1 (initail coding scheme for GPRS is CS2) but with no effect power control settings are same for both EDGE and GPRS........looking for a reason rep would be added for a correct reply. Thanks......


perhaps the mention of vendor would ease a suggestion :rolleyes:

[ghamiz]

please note am not IN TO optimization :)

i assume by the KPI names that your vendor is Huawei, though I am new to this vendor, but i think the resource capability measurement will tell you about the resource distribution between GPRS and EDGE.

you may check the available resources for edge to be insufficient, check EDGE utilization to be high, check if edge resources are occupied by gprs, try increasing dynamic resources or ideally increase static resource. it is also possible that the radio conditions in the area are too worse to support EDGE, retransmission rate (or CS quality stats) can tell you that!


what ever you do, kindly do share your findings :D

[usama0795]

Hey bro the problem is not actually related to EDGE utilization since number of attempts are alomost same for both the services I did get the trace information and obserevd problem with single TLLI (single MS) i m really confused what parameter settings i should use to correct this issue....should i track down the user and ask him to stop using EGPRS :)....but conditions are mostly the same the default uplink coding scheme (coding scheme used to send first RLC block) is MCS1 which has alomost the same covolutional coding rate as CS2 and has the same coverage.............kindly suggest anything (vendor is huawei)

[ghamiz]

Hey bro the problem is not actually related to EDGE utilization since number of attempts are alomost same for both the services I did get the trace information and obserevd problem with single TLLI (single MS) i m really confused what parameter settings i should use to correct this issue....should i track down the user and ask him to stop using EGPRS :)....but conditions are mostly the same the default uplink coding scheme (coding scheme used to send first RLC block) is MCS1 which has alomost the same covolutional coding rate as CS2 and has the same coverage.............kindly suggest anything (vendor is huawei)

dear, an optimisation person can guide you better in this regard, what i think is that you may not tweak the parameters for a single user. there are now many Chinese handsets in the market that are not 3GPP compliant, and pose many problems to the network (no offense to my Chinese brothers :D). still you can play with N3101 whose recommended value in Huawei is 20. If you increase its value, NW will wait more before releasing the TBF. If you have Nokia on your core side you can determine the MS types that are used in the cell (through Traffic Views). If the MS is not checked of disturbing the NW barr him :p

[usama0795]

I analyzed the trace again for whole day and the issue is user has already been allocated a TBF and still but the specific MS keeps on sending channel requests and the MS fails to repond to Packet Uplink Assignment with a valid data block since according to the carried TLLI TBF has alrady been established....i m really confused played along with all the parameters n3101 increased it to 30...t3168 increased it to 2000ms....enabled one phase access.....shifted the PDCH to different radio....changed UL Conding Scheme to MCS1.......i know these parameter changes wont have any impact since how can i restrict channel request from TLLI if it has already a TBF established......confused like anything.........

[Rashid]

simple question :
just happend on this handset and this sector coverage or generally on whole your network or all sector coverage? trying to make simulation
1.same handset different card
2.same card different handset

[usama0795]

no degradation is persisting on 3 sectors of different sites looking at the same designated place and I checked traces for different cells in network having same issue of degraded EDGE TBF Uplink Assignment Success Rate but good GPRS TBF Uplink Assignment Success rate and observed different single TLLIs causing the same problem........and degradation is intense I mean more then 500 failures in 1 hour.....

[adewijaya]

no degradation is persisting on 3 sectors of different sites looking at the same designated place and I checked traces for different cells in network having same issue of degraded EDGE TBF Uplink Assignment Success Rate but good GPRS TBF Uplink Assignment Success rate and observed different single TLLIs causing the same problem........and degradation is intense I mean more then 500 failures in 1 hour.....

1. check failure due to no channel (i mean multislot blocking for uplik request)

2. how about PDTCH channel did you setting, is it enough or not? before this review make sure within voice traffic increament

3. last but not least review your counter, very advantages if you attach in this thread.

Note : review with Gb and NSEI (NSVCI) load on PS core side will more advance

[usama0795]

Hey bro failures are not due to congestion as enough PDCH configured on the cell 3 static PDCH and 40% dynamic PDCH I did reset the PTP BVC so any issue with defined CI can be resloved but any issue at PS core side would either effect multiple TLLIs and would be visible on mutiple cells......i m attached a figure to highlight the extent of degradation and is continuously persisting now and the figure is for one cell.....

[Irna]

Hey bro failures are not due to congestion as enough PDCH configured on the cell 3 static PDCH and 40% dynamic PDCH I did reset the PTP BVC so any issue with defined CI can be resloved but any issue at PS core side would either effect multiple TLLIs and would be visible on mutiple cells......i m attached a figure to highlight the extent of degradation and is continuously persisting now and the figure is for one cell.....

not strange this graph, related between it. So what's real problem? for UL rejected due to MS make it consider to
1. type MS that rejected message (all type or not?)
2. in case problem on most type handset, make attention with
a. last activity upgrade software on your BSC or SGSN
b. alarm on your BSC side

[ghamiz]

Hey bro failures are not due to congestion as enough PDCH configured on the cell 3 static PDCH and 40% dynamic PDCH I did reset the PTP BVC so any issue with defined CI can be resloved but any issue at PS core side would either effect multiple TLLIs and would be visible on mutiple cells......i m attached a figure to highlight the extent of degradation and is continuously persisting now and the figure is for one cell.....

dear...i consulted my HUAWEI RF support guy on this and he too agreed with me that this is an MS specific problem not NW. There is no parameter through which you can save your KPI degradation, and as i already suggested you, if you wanna save your KPI then barr this number (from ps core side). A single thing you can do first is to confirm the MS type (and model) of the user. if it is a 3G-compliant set, there is a possibility that there is a software on the MS that is sending recurrent requests. Also it may not be an MS at all, check if it is a tracker device.

[dfindme]

halo i have some problem TBF failure rate so high, whether this is related to the utilization of E1?

[ghamiz]

halo i have some problem TBF failure rate so high, whether this is related to the utilization of E1?

if u can pls mention the vendor name, it would then be easy to suggest :rolleyes:

[maverrickforever]

hey everybody, if you can actaully find if the radio conditions of the particular handset in question are really bad sometimes it may happen that due to bad radio conditions the Ms is really not able to respond to the paging. If it is a chinese handset ( no offence to my chinese brethren , god bless them for their work) it is likely the sensitivity is really low thus causing problem. Has any body checked the radio conditions.

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