Log in

View Full Version : Question 3G 2G Handovers



makeev
2012-11-13, 07:28 PM
Setting Inter-frequency handover preference over inter-rat handover preference for CS service.

Problem:
We have been starting to introduce F2 layers in our network. We activated inter frequency handovers in RNC between F2 > F1. But from the stats we can see that 100% of time handovers to GSM (inter-RAT) are preferred! No handovers from F2 to F1. From the signalling we can see that during RAB establishment the MSC is sending to RNC service priority" Handover to GSM should be performed" . Does it mean that in our network this parameter sets higher priority for GSM handover over inter-frequency handover? If yes , how to change it in NSN MSC? Which parameter is responsible for this? Anything else we should know?


Recommendation needed :
Inter - frequency has higher priority than inter system handover . But if inter frequency is not available (or activated) will handover to GSM happen? What paramter to retune inorder to have these handovers ?


Thanks

electron
2012-11-13, 09:18 PM
Just relation definition does not mean that HO should be take place . actually there is a parameter that is specifying in compressed mode which sort of HO should be considered look at "hoType " parameter it should be set to Inter frequency proffered .
Setting Inter-frequency handover preference over inter-rat handover preference for CS service.

Problem:
We have been starting to introduce F2 layers in our network. We activated inter frequency handovers in RNC between F2 > F1. But from the stats we can see that 100% of time handovers to GSM (inter-RAT) are preferred! No handovers from F2 to F1. From the signalling we can see that during RAB establishment the MSC is sending to RNC service priority" Handover to GSM should be performed" . Does it mean that in our network this parameter sets higher priority for GSM handover over inter-frequency handover? If yes , how to change it in NSN MSC? Which parameter is responsible for this? Anything else we should know?


Recommendation needed :
Inter - frequency has higher priority than inter system handover . But if inter frequency is not available (or activated) will handover to GSM happen? What paramter to retune inorder to have these handovers ?


Thanks

white_Noise
2012-11-14, 03:08 PM
Setting Inter-frequency handover preference over inter-rat handover preference for CS service.

Problem:
We have been starting to introduce F2 layers in our network. We activated inter frequency handovers in RNC between F2 > F1. But from the stats we can see that 100% of time handovers to GSM (inter-RAT) are preferred! No handovers from F2 to F1. From the signalling we can see that during RAB establishment the MSC is sending to RNC service priority" Handover to GSM should be performed" . Does it mean that in our network this parameter sets higher priority for GSM handover over inter-frequency handover? If yes , how to change it in NSN MSC? Which parameter is responsible for this? Anything else we should know?


Recommendation needed :
Inter - frequency has higher priority than inter system handover . But if inter frequency is not available (or activated) will handover to GSM happen? What paramter to retune inorder to have these handovers ?


Thanks

Which vendor? And what are the values you are using for 2D/2F for RSCP and Ec/No for the Inter-Freq and IRAT HOs? and what's the strategy you are using between F1 and F2? Load balancing? Service Steering (DRD) ? Do you have Blind handover between F1 and F2? it actually depends on many factors and parameters..

makeev
2012-11-14, 08:36 PM
Which vendor? And what are the values you are using for 2D/2F for RSCP and Ec/No for the Inter-Freq and IRAT HOs? and what's the strategy you are using between F1 and F2? Load balancing? Service Steering (DRD) ? Do you have Blind handover between F1 and F2? it actually depends on many factors and parameters..
Thanks for the reply. The vendor being used in my Netowork is NSN.
Can I retune InterFreqMinHoInterval and InterFreqMinMeasInterval to encourage Frequency based handovers , right now both are set to default values of 10s & 2s.

white_Noise
2012-11-14, 08:57 PM
Thanks for the reply. The vendor being used in my Netowork is NSN.
Can I retune InterFreqMinHoInterval and InterFreqMinMeasInterval to encourage Frequency based handovers , right now both are set to default values of 10s & 2s.

You should start with the parameters, before getting to change the timers..So double check the compressed mode threshold for Inter-Rat and Inter-Freq 1st.

makeev
2012-11-14, 09:22 PM
You should start with the parameters, before getting to change the timers..So double check the compressed mode threshold for Inter-Rat and Inter-Freq 1st.
Thanks for the quick reply. I am fairly new to this so if you can mention the exact name of parameter it will help me alot more.

These are the current settings we have and Compressed Mode is enabled

MaxNumberUECmHO 16
MaxNumberUECmSLHO 6
ServHONumbUEInterFreq 1
ServHONumbUEInterRAT 1
ServHOPeriodInterFreq 0
ServHOPeriodInterRAT 0

white_Noise
2012-11-14, 10:12 PM
Thanks for the quick reply. I am fairly new to this so if you can mention the exact name of parameter it will help me alot more.

These are the current settings we have and Compressed Mode is enabled

MaxNumberUECmHO 16
MaxNumberUECmSLHO 6
ServHONumbUEInterFreq 1
ServHONumbUEInterRAT 1
ServHOPeriodInterFreq 0
ServHOPeriodInterRAT 0

Actually I would be very glad to help, but I'm not at all familiar with NSN parameters :(

rsv12
2012-11-30, 03:21 AM
Hi,
NSN does not have "hoType" parameter, E******* has it. NSN uses one parameter set for triggering compressed mode for inter-freq and inter-system feq. to measure. What to measure depends on the RNC. RNC decides witch system or frequency to measure. Actually this depends on the service priority parameter. In you case "Handover to GSM should be performed" meaning higher priority for inter system ho.