SPDCH

Hey,

Jus one last question. Do we need to allocate dedicated Abis TS when giving SPDCH=1?

spdch = pdch 🙂 it is exactly the same thing.

Hi,
On the radio (TRX/TS) level, an SPDCH is the same as an FPDCH. The only difference is in the PCU. In the PCU, the GSL devices for FPDCHs are also fixed, while for SPDCH, they’re allocated on-demand.

From the PCU perspective, it’s more advantageous to use SPDCH instead of FPDCH, ‘cos it’ll use your GSL devices more optimally.

If your voice traffic is very high, then you MIGHT INITIALLY have high PDCH allocation failures when you activate SPDCH (same goes for FPDCH), ‘cos the BSC will not get any idle TCHs to convert to the PDCHs.

After some time (when the SPDCHs have been successfully allocated), then your PDCH allocation failures will purely depend the level of your CS traffic and the setting of parameters such as TBFULLIMIT or TBFDLLIMIT.

Regards,

SHELDON

Hi sheldom,

TBFULLIMIT or TBFDLLIMIT in our network is 2,0 and per cell we have defined 2 – fpdch + 2- spdch.

So by this parameter per pdch only 2 tbf is allowed? and this is a soft limit?

because when number of edge user increases then per pdch max how much allocation will be done? i mean what is hard limit?

is it 32 tbf per p-set or per pdch?

Hi Sheldom,

i want to know per pset how many max pdch +spdch u can give.i am using erc sys and here for chgr 0 (bcch) we have 4(2 spdch + 2 spdch) and samr for chgr 1.

so max how many edge timeslot per pset?

and second one u said in ul max 7 and dl 16 .it means per pdch at a time i can handle 25 tbf and in case if i have 5 edge timeslot in one pset then it means 5*25 = 125 tbf(ul+dl) i can handle ?

Hi Safar,

Sorry for my late reply. I was on vacation, so I wasn’t visiting the forum again.

Per PSET, the maximum number of PDCHs is 8, whether the PDCHs are FPDCHs, SPDCHs, on-demand PDCHs or a mixture of these three. The maximum number of EDGE time slots per PSET is also 8, since these time slots are also PDCHs.

In each cell, maximum number of FPDCH+SPDCH is 16.

I don’t quite understand your analysis of the no. of TBFs. By 25, you mean 16+7? To get a clearer picture of the total number of TBFs for 5 EDGE timeslots, it’s better to treat the UL and DL separately. Thus, for 5 TSs, maximum no. of DL TBFs = 5*16=80 and maximum no. of UL TBFs = 5*7=35.

Regards,
SHELDON

Hi Safar,

I didn’t say the maximum number of EDGE timeslots is 16. This is what I said “In each cell, maximum number of FPDCH+SPDCH is 16.” I hope you’re not equating EDGE to FPDCH+SPDCH.

The maximum number of EDGE timeslots in a cell is equal to the maximum number of PDCHs you can have in the cell.

Regards,
SHELDON

hi sheldom,

Are u there or again on leave?