Huawei 3G: HS PDSCH Codes Min set to 15

[apurvabelekar]

Hi Experts,
I am working for Huawei 3G , where I tuned HS-PDSCH Code Num Minimum to 15 in few cells.
Threorotically all my codes should be allocated to HS and there should be zero CS Traffic & R99 Traffic. But no code was allocated HS, HS Volume was zero, and everywhere it was either R99 and CS traffic or idle. On the other hand when I made HS PDSCH CODE Num Minimum to 14, the CS Traffic dipped drastically and HS Volume increased.
Please can anyone explain why didnt the same thing happened for 15 min codes.
Thanks in Advance.

[miri]

Hi,

Theoretically you can assign all 15 codes to HSDPA but practically it does only work in very special cases.
Assume you have your 15 codes reserved, remains one SF16. From this you need space for the common channels. Remains one SF32. Here you have to pack the HSDPA control channel(s) and the associated DCH channels for HSDPA.
How many HS-SCCH are configured?
If you have 4 HS-SCCHs than the code tree is already full and no associated DCH can be set up, this means no signalling so no HSDPA !
If you also have control channels of HSUPA than there is even less place :)

PS, reputation would be appreciated

[jayk]

HS Traffic volume depends on the no. of users and code usage. HS Volume will increase by increasing codes if codes are scarce. As you explained that when minimum codes were changed from 0 to 14; the CS Traffic reduced and HS volume increased. It is evident that there are no more codes available for CS and PS is allocated much codes even if there is no HS traffic. As minimum codes were changed from 14 to 15 it does not make any difference in HS volume because HS codes are already abundant. Regards, jack.