- This topic has 8 replies, 1 voice, and was last updated 10 years, 9 months ago by DKS.
23rd March 2010 at 17:50 #61677SAMGuest
Can anyone explain me for GPRS/EDGE, suppose I have 2TRX in one cell and I have 2 SDCCH and 2 PDCH (1 dedicated and 1 dynamic PDCH). Now my question is only this 2 assigned PDCH will be used for DATA traffic? What will be the data rate for this 2 PDCH (CS1,CS2,CS3,CS4)? If I want to use more TS for DATA if there is no voice load in the cell do I have to increase the number of PDCH ??23rd March 2010 at 19:41 #61678pixGuest
yes, only 2 PDCH available in your cell
the data rate depends on your parameter settings (which system are you using ?)
yes, you should increase the nuber of dynamic PDCH. In the voice load is low, the PDCH will increase. If voice is high, PDCH are going to decrease.
pix24th March 2010 at 10:39 #61679SAMGuest
We have Siemens system. GPDPDTCHA is the parameter that you are talking?
Thanks.24th March 2010 at 19:52 #61680pixGuest
oh, i don’t know siemens, sorry… the concept is correct, but i cannot translate it in parameters.
pix29th March 2010 at 09:54 #61681MithuGuest
If u use only CS1~CS4(9.05~21.4Kbit/s), for better data rate u have to ensure better radio envoroment.U can also modify the parameter setting GMANMSAL to control the no of MS per PDCH in the cell.
If u have EDGE license u can enable EEDGE parameter & improve throughput(data rate) by assinging coding scheme MCS1~MCS9(Upto 59.2Kbit/s). By using parameter GPDPDTCHA u can dynamically use cs ts as ps ts. u can assign value 100/50 depends using 100% or 50% of free TCH.31st March 2010 at 08:41 #61682SAMGuest
Thanks Mithu.1st April 2010 at 07:14 #61683NJGuest
In Siemens the parameter is, for edge: EMANPRESPRM,
and for gprs:GMANPRESPRM,
the parameter:GPDPDTCHA is GPRS Percentage of dynamic PDTCH Available,indicates the % of available ‘shared’ tch
may be used for GPRS traffic.
Hope it can helps.
NJ5th April 2010 at 03:17 #61684pcsGuest
In Alcatel, we have 3 types of PDCH. THat is MAX_PDCH, MAX_PDCH_HIGH_LOAD and MIN_PDCH.
MAX_PDCH = Dynamic + Max_High_LoadPDCH (>=Max_highLoadPDCH)
MAX_PDCH_HIGH_LOAD = >=Min_PDCH
Min_PDCH = Dedicated PDCH
Example : Min_PDCH = 2, MAX_PDCH_HIGH_LOAD = 3, MAX_PDCH = 6
It means ==> 2 PDCHs are only for data, can’t be seized by TCH, but when PDCH access increase, max PDCH can be used is 6 pdch. If PDCH utilized are 3 PDCHs (Max-PDCH_HighLoad), that 1 PDCH can’t be seized by TCH. But IF PDCH utilized is 4, 5, or 6, only 3 PDCHs can be seized by TCH, but not the 3 others.
When PDCH numbers seized reach the minimum number of MAX_PDCH_HIGH_LOAD,then those PDCHs are unable to be used for TCH.
From my Experience, it doesn’t matter if we want to increase the PDCH Number if the voice traffic is low.
The speed/data rate of GPRS/EDGE also depends on Abis capcity. There is a mappign of PDCH allocation and Abis TS.
In Alcatel, sites which have high GPRS/EDGE access are added 1 E1 Abis (max 2 Abis), then we allocate Abis TS for Data only, especially in 2nd abis. That will significantly increase the data access speed.
PCS9th April 2010 at 12:45 #61685DKSGuest
Will you give some light on the PDCH mapping on Abis link. How it is defined what is the calculation beyond this.