- This topic has 2 replies, 1 voice, and was last updated 13 years, 4 months ago by Samir.
7th November 2007 at 03:18 #49611marvelGuest
Could you explain me How to calculate requirement number of GPRS channel (Dedicated PDCH) on air interface and PDTCH (Packet data traffic channel) on abis interface.
marvel7th November 2007 at 04:59 #49612wise Amin man FauzanGuest
Assume this is not new GPRS deployment instead of optimization issue on growing GPRS network.
A. GPRS Channel on Air-IF on cell basis or network basis:
– Estimate most suitable Coding Scheme (CS) being used through planning tool (e.g. Netact) by deriving C/I, or get data traffic distribution from Packect Control Unit (PCU) performance measurement (PM) thus you able to know which CS dominantly used. It is not limitted to to used only single CS, you can weight some CSs to be took into account.
– Get PS traffic volume from PM data on average of busyhour some couple days, sum up the user traffic data and signaling data for each connection UL/DL.
– Through above steps output, you will able to estimate number of required radio TS number for packet data service such GPRS or even EDGE.
– Using specific vendor feature (e.g. vertical/horizontal TS allocation, dinamic GPRS TS allocation, etc.) you will able to adjust number of GPRS channel to get optimum loading.
B. GPRS Channel on Abis-IF on BTSM (bts manager) basis or network basis:
– CS and PS service share the same resource on Abis, you have to provide enough #PCMB for both services.
– It depends on PCU capacity for each manufacture and current access methode (GPRS or EDGE). Particular s/w release on certain vendor maps 1PDCH : 1PDTCH when using GPRS, 1PDCH : 1-5PDCTH when using EDGE. However, again .. you may approach by giving weighted value for coding scheme distribution dominantly used over the BTSM. How many PDCH are required and how is the CS occurence (weighting value) being used on Air-IF then multiply them. Thus you need lookup table between #PDCH on variying CS versus #PDTCH.
– On the overall,requirement of PDCTH for all sites in the network then be calculated so you get number of PCU have to be installed on the BSC.
I’m sure it’s confusing without practical calculation such it is on the spreadsheet; that’s what i mean.6th January 2008 at 14:38 #49613SamirGuest
I am using Siemens BR7, I would like to nkow which scanner gives the number of occuped PDTCH per BSC? is it NPDCHPCU (0,19)?