My success Story

We had been facing a network issue in the mids of this year. The problem was Iphone 5 and 5s was unable to camp on to our 3G network and we were awestruck with the problem. We didn’t know why it was happening only with the Iphone. We raised a ticket for the problem and we were asked to send the logs and traces of the problematic NodeBs. But still then the issue was not solved. From our side too we kept on trying and looking for solutions in hedex and online support website. Finally we came across a same story where UE was unable to camp on to a NodeB.

We came to know that the problem was not with the NodeB or the 3G network but due to some parameters in a neighbouring GSM  BTS. The two parameters which were not allowing UE to camp onto NodeB was Q search I and Q search P under GCELLTRANSYS (Call control UTRAN System Control message).

 

Upon looking into what the two parameters were actually. The following is what we found out:

Q search I

Meaning: This parameter specifies the level threshold for cell reselection in idle mode. In idle mode, if the signal level of the serving cell is below [0, 7] or above [8, 15], the MS starts to search for 3G cells. For example, if this parameter is set to 5 and if the signal level of the serving cell is lower than 5, the MS starts to search for 3G cells; if this parameter is set to 10 and if the signal level of the serving cell is above 10, then the MS starts to search for 3G cells. The values of this parameter correspond to the following decibel values: 0: -98 dBm

1: -94 dBm 2: -90 dBm

3: -86 dBm 4: -82 dBm

5: -78 dBm 6: -74 dBm 7: (always), that is, the MS keeps searching for 3G cells 8: -78 dBm

9: -74 dBm 10: -70 dBm 11: -66 dBm 12: -62 dBm 13: -58 dBm 14: -54 dBm 15: Positive infinity(never), that is, the MS does not search for 3G cells

GUI Value Range: 0~15

Actual Value Range: -98, -94, -90, -86, -82, -78, -74, (always), -78, -74, -70, -66, -62, -58, -54, Positive infinity(never)

Unit: None

Default Value: None

Recommended Value: 15

 

Qsearch P

Meaning: This parameter specifies one threshold of the signal level for cell reselection in packet transfer mode. In packet transfer mode, if the signal level of the serving cell is below [0, 7] or above [8, 15], the MS starts to search for 3G cells. For example, if this parameter is set to 5 and if the signal level of the serving cell is lower than 5, the MS starts to search for 3G cells; if this parameter is set to 10 and if the signal level of the serving cell is above 10, then the MS starts to search for 3G cells. The values of this parameter correspond to the following decibel values: 0: -98 dBm 1: -94 dBm ... 6: -74 dBm 7: (always) 8: -78 dBm 9: -74 dBm ... 14: -54 dBm

 

GUI Value Range: 0~15

Actual Value Range: -98, -94, -90, -86, -82, -78, -74, (always), -78, -74, -70, -66, -62, -58, -54, Positive infinity(never)

Unit: None

Default Value: None

Recommended Value: 15

 

We did this change in our network whereby the values for Qsearch I and Qsearch P parameters of GSM  BTS were set to 7 and the problem was resolved. Thanks to support website whereby we could find an easy and understandable solution from there and the prevailing problem with Iphone unable to latch was solved successfully. 

Its a great success story keep on posting

Thanks for sharing & it will inspire a lot...