[Fahim]

In case of multiband cells if AMR is enabled in overlaid cell only -is there any possibility of call being dropped while HO from overlaid cell to underlaid cells

[pix]

hello fahim,

if you have AMR call in a cell, and a HO is trigerred to move away from this cell, the codec in the new cell will be chosen accordingly to your radio parameters (TFO… AMR disabled… etc)

If AMR is forbidden in the target cell, then the new codec will be a supported codec by MS (negociation between TC and BTS)

pix

[cairem]

why in multiband cells eg 900 and band and 1800 band, why is the call on ms always made on the 1800 band before 900?

[pix]

hi cairem,

because of the parameters’s values defined in the cell by the operator. The operator certainly needs to “push” call setup on the 1800 cells in order to force those cells to carry more traffic.

Indeed, the 1800 cells provide a cleaner frequency usage and more capacity than the 900 cells.

pix

[Fahim]

Hello Pix,

Thanks for your answer. But incase of Multibad cells – both 900 & 1800 BTS sectors are merged into one cell. Let me put my question in another way – in such a cell there is congestion in 900 TRXs/ with AMR-HR but in fact most of the TSs of 1800 are not carrying traffic and there is no HR enabled 1800 TRX — what could prompt this ?

[pix]

fahim,

the multiband cells are using special algorithm to HO the calls in 900/outer to 1800/inner zone.
you should set the RXLEV_DL_ZONE and RXLEV_UL_ZONE, and the ZONE_UL_HYST and zone_DL_HYST…

it’s a bit complicated, i suggest you refer your problem (and how you would like your cells to behave) to your optimization engineer (or alcatel engineers…)

[EUGE2007]

Hi Cairem,
You make calls on the band you have set as the prefered band in your system. coz for our network CS is on 900 then it hands over to 1800. are u using ericsson or siemens bscs? i can give u more infor.

[cairem]

hi euge
it is ericsson bss system,

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