BCCH change during Dedicated mode

**okkin04** · 2013-09-24, 03:21 PM

hi,

having this problem in huawei, during handover. it starts in idle mode and then connected mode which is dedicated. Now, the bcch changes when in dedicated mode and when disconnected it back to the previous channel when in idle mode. Could anyone explain why this happened? thanks for the inputs.

**Finetopix** · 2013-09-24 03:21 PM

**Optimustron** · 2013-09-26, 02:53 PM

Okkin, is hard to explain because is confuse your explanation, you say during HO it starts in idle mode, but HO only is for connected mode or dedicated because in idle the mechanism/procedure is the cell selection/reselection, Are you in a fixed place or you are moving?, Do you make a call in the coverage of one site a you go to another?. I am going to explain some things assuming some conditions, for example if you are in a fixed place and you make a call you can have initially in idle mode BCCH A, and when you get connected you can catch another BCCH B, why?, well first because maybe the cell with BCCH A is congested and HO on SDCCH is activated then you get BCCH B, or the second posibility is that you have the cell with BCCH A barred and the cell with BCCH B is not, or third you can have Assign to Worst Cell, AW, activated on this two neighbors having the worst cell with BCCH B with that offset for this condition, another posibility is that you don't have or is a malfunctioning of the SDCCH with BCCH A then you get the cell with BCCH B, however in idle you have the BCCH A because your are under de selection/reselection mechanism/procedure, another posibility is that you can have the minimum access to cell and the parameters for selection/reselection differents, for example you have rxlev access for cell with BCCH A greater than rxlev access for cell with BCCH B, then when you set up a call you get BCCH B because the access level is lower, but you have the selection/reselection opposite to rxleve access, i.e. you have this lower for cell with BCCH A the in idle you have that cell. Is hard to explain because I don't know the right conditions however I hope some one of the possibilities help you, best regards,

**kape** · 2013-09-26, 04:08 PM

It could be due to idle mode offsets as well, look at C2 value. Sometimes offset(CRO) is applied on the 1800 capacity layer in dualband (900/1800) networks.

**okkin04** · 2013-10-01, 12:56 PM

Originally Posted by Optimustron

Okkin, is hard to explain because is confuse your explanation, you say during HO it starts in idle mode, but HO only is for connected mode or dedicated because in idle the mechanism/procedure is the cell selection/reselection, Are you in a fixed place or you are moving?, Do you make a call in the coverage of one site a you go to another?. I am going to explain some things assuming some conditions, for example if you are in a fixed place and you make a call you can have initially in idle mode BCCH A, and when you get connected you can catch another BCCH B, why?, well first because maybe the cell with BCCH A is congested and HO on SDCCH is activated then you get BCCH B, or the second posibility is that you have the cell with BCCH A barred and the cell with BCCH B is not, or third you can have Assign to Worst Cell, AW, activated on this two neighbors having the worst cell with BCCH B with that offset for this condition, another posibility is that you don't have or is a malfunctioning of the SDCCH with BCCH A then you get the cell with BCCH B, however in idle you have the BCCH A because your are under de selection/reselection mechanism/procedure, another posibility is that you can have the minimum access to cell and the parameters for selection/reselection differents, for example you have rxlev access for cell with BCCH A greater than rxlev access for cell with BCCH B, then when you set up a call you get BCCH B because the access level is lower, but you have the selection/reselection opposite to rxleve access, i.e. you have this lower for cell with BCCH A the in idle you have that cell. Is hard to explain because I don't know the right conditions however I hope some one of the possibilities help you, best regards,

-sorry to confused you. the case is this when im having handover test. this is for indoor. outgoing and incoming handover test. now when i started setting this test. my logfiles started in idle mode first. then when dialed and connected which is in dedicated mode. now my problem is that during the idle mode the bcch of the serving cell is not the same when in dedicated mode already. the bcch is changed when entering dedicated mode yet the cell id is the same for both BCCH. After that, when now disconnected it back to the previous bcch when in idle mode.

**Optimustron** · 2013-10-02, 01:21 AM

Okkin, Please check if you have crossed your jumpers or feeders only one per sector, i.e. for sector Alpha you can have Rx/TxA1 with Rx/TxB1 and in sector Betha you can have Rx/TxA2 with Rx/TxB2, but the right configuration must be Rx/TxA1 with Rx/TxA2 for Alpha and Rx/TxB1 with Rx/TxB2 for Betha, if they're crossed you can have drop call too, another possibility is that you have Overlay/Underlay or Concentric Cells with BCCH en both cells and that is a misscofiguration, because you only need one BCCH for Underlay/Overlay or Concentric Cells, by the way you must check too your drive test tool database, in the past we have some problems with that issue same as you said but that were wrong database. If anything works delete cells database and create a new cell database if possible with new cell id maybe is an obscure bug in the BSS system release. I hope this help you if not please tell us, somebody can have the solution, and I will keep making research because is interesting this case it isn't common what happen this situation. Best Regards,

**CliveMangwiro** · 2013-10-10, 06:50 AM

Originally Posted by Optimustron

Okkin, Please check if you have crossed your jumpers or feeders only one per sector, i.e. for sector Alpha you can have Rx/TxA1 with Rx/TxB1 and in sector Betha you can have Rx/TxA2 with Rx/TxB2, but the right configuration must be Rx/TxA1 with Rx/TxA2 for Alpha and Rx/TxB1 with Rx/TxB2 for Betha, if they're crossed you can have drop call too, another possibility is that you have Overlay/Underlay or Concentric Cells with BCCH en both cells and that is a misscofiguration, because you only need one BCCH for Underlay/Overlay or Concentric Cells, by the way you must check too your drive test tool database, in the past we have some problems with that issue same as you said but that were wrong database. If anything works delete cells database and create a new cell database if possible with new cell id maybe is an obscure bug in the BSS system release. I hope this help you if not please tell us, somebody can have the solution, and I will keep making research because is interesting this case it isn't common what happen this situation. Best Regards,

Okkin, have you found a solution for your problem? I suspect a slipt cable to the TRX carrying your BCCH, check your connections

**okkin04** · 2013-10-11, 10:34 AM

Dont have yet time to visit the site, i will let you know once accessed. thanks

**miles12** · 2013-10-15, 05:07 AM

Originally Posted by okkin04

-sorry to confused you. the case is this when im having handover test. this is for indoor. outgoing and incoming handover test. now when i started setting this test. my logfiles started in idle mode first. then when dialed and connected which is in dedicated mode. now my problem is that during the idle mode the bcch of the serving cell is not the same when in dedicated mode already. the bcch is changed when entering dedicated mode yet the cell id is the same for both BCCH. After that, when now disconnected it back to the previous bcch when in idle mode.

Dear Okkin,As per your describe i think you Mean TCH fre!!!!