[Zbigniew]

Hi all,

I am looking for a reasonable KPI to calculate the GPRS & EDGE Traffic (in Erlang, not the data volume) for Siemens BSS.

The counter NALLPDCH (9,25) shows the minimum, average and maximum number of PDCH in a cell but how is this related to the GP Timeslots ?

Any hints are welcome.

Tnx Zbigniew

[Pix]

Hello,

What is “GP” timeslots ? (sorry, I’m not working with Siemens, but I can try to help)

Do you mean “Gb” ?

The best KPI to calculate EGPRS traffic is the data volume, why do you need Erlang ?

I assume that you are trying to compute the traffic on the interfaces, and see if the interfaces are congested or not? In this case, the best KPI would be the interface load, if you have t 🙂
For instance, in alcatel, each interface (Abis or Ater) can be divided in “nibbles” (= 16kb/s = one quarter of a timeslot). And there are indicators that say how much nibbles are used at BH, and how many are available.

So it’s really simple to check the load (busy / available)

On the Gb interface, we are using a frame relay interface, which capacity is counted in kb/s, so it’s ok to work with data volume or data throughput.

I’m sorry again not to answer your question precisely, but perhaps it can give you some ideas.

Cheers,
Pic

[Zbigniew]

Hello Pix,

GP Timeslots means GPRS Timeslots in Siemens BSS. There is a difference between “Dedicated GPRS Timeslots” (i.e. the number of GPRS only timeslots) and “Default GPRS Timeslots” (i.e. the number of timeslots after territory upgrade). Unfortunately the number of used timeslots for GPRS are not counted, only the number of PDCH (GPRS Sessions) is evaluated.

I need Erlang to see the overall timeslot usage in the cell (x % traffic, y % GPRS, z % EDGE etc.)

Kind Regards

Zbigniew

[Pix]

Hello,

Ok, I understand better now. But I really can’t help…
NALLPDCH seems to be counting all the used PDCH in the cell, isn’t it ?
1 PDCH = 1 timeslot used for (E)GPRS transfers

If you want to convert this in erlang, you need to mutliply it by the observed period

For instance, in one hour :
5 PDCH used in the cell in average –> 5 * 3600 / 3600 = 5 erlangs for that hour.

Cheers,
Pix

[toto]

Hello,
you can try this , to calculate the date_traffic in Erlang…
(Nallpdch_Meadl/3600) as DataTrafficDL in Erl and
(Nallpdch_Meaul/3600) as DataTrafficUL in Erl

[Zbigniew]

Hello Pix, hello Toto,

I think the problem is that a GPRS Timeslot can include multiple PDCH (GPRS & EDGE sessions).

Maybe it is impossible to calculate the traffic in Erlang because the average number of used timeslots for these sessions is not known.

Thank you !

Kind Regards

Zbigniew

[Pix]

Well, perhaps Siemens did a mistake in their vocabulary, but 1 PDCH = 1 Timeslot. A PDCH is a physical timeslot. You can’t have more than 1 PDCH in one timeslot.

… And, within 1 PDCH you can multiplex several TBF (several users).

So the formulas we proposed should be valid.

What is Nallpdch_Meadl ?

[toto]

Hi all,Nallpdch_Meadl means mean number of used PDCH’s(active TBF’s) per cell in DL

[Pan]

Dear, all! PDCH is PDCH in Siemens too: “The physical channel (one timeslot of the TDMA frame) assigned to the Packet Data
Services (PS) (either statically or dynamically) is named “Packet Data Channel (PDCH)”. PDCH is not equal TBF. There is possibility to create up to 16 TBFs in one PDCH. I.e. one TS (PDCH) can include up to 16 TBFs (not PDCHs).

[Pix]

Pan, obviously i agree with you (again !).

Any help about “TFO in Alcatel”… the Supplementary Services ?

[Sammy]

For Voice its
Total voice traffic (Erl) MEBUSTCH[1..4]

For GPRS/EDGE in Kb its

((MUTHRF[1..26] + REMUTHRF[1..13] + MSTHRF[1..2]) * 8/1000)*GRAN*60

This is how we calculate but I dont know abt erlangs. Anyway good to see someone talking about Siemens

[Sammy]

I agree with Pix and Pan…1 TS cannot have multiple PDCHs

1 TS=1 PDCH= multiple TBFs

In case of extended range channels…we assign two Time slots

[Pix]

Sammy,

“Anyway good to see someone talking about Siemens”

Isn’t it Nokia-Siemens ? 🙂

[Pan]

Well, Pix! I will try:)

[Sammy]

Yes it is Nokia-Siemens…but Nokia customers use Nokia equipmwnt and Siemens customers use Siemens equipment…Its just a change of name for me

[Author]

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