UMTS HSDPA Speed

**telecom.santosh** · 2011-05-20, 05:38 PM

My Question is One of my 3G site configure with 4 E1. Each E1 have maximum 2MPBS Speed so total max speed will be 8MBPS. But at site, I am getting 8.5MBPS or above speed, Why it so? Is it because of Modulation(64QAM), which i m using in site?

**Finetopix** · 2011-05-20 05:38 PM

**agenov** · 2011-05-20, 07:25 PM

Originally Posted by telecom.santosh

My Question is One of my 3G site configure with 4 E1. Each E1 have maximum 2MPBS Speed so total max speed will be 8MBPS. But at site, I am getting 8.5MBPS or above speed, Why it so? Is it because of Modulation(64QAM), which i m using in site?

This is not possible. Are u sure you have only 4xE1 Iub, double check it again what is Iub bandiwdth..

BR

**telecom.santosh** · 2011-05-20, 07:31 PM

I am very much sure.

**dekili** · 2011-05-20, 09:51 PM

E1 assumes 2Mbps and it can't be higher. If you have more than 2Mbps then it is not E1. E1 standard is 2Mbps and it is not any longer as per standard. What might be the situation is that you are having 4xE1 transport capability but you have either some kind of compression implemented or you are checking the rate at the point where some kind of overhead is already included...
Using higher order modulation is possible and you will get higher throughput but it is not any longer E1 but propriatery solution...

**zeezzoo** · 2011-05-20, 10:29 PM

it can't be . make sure that the formula you are using is right .
are you calculating on daily basis or hourly basis or DT?
the throughput you are calculating is for RLC or LLC or MAC-HS .....?

dear share me the formula you are using & the vendor name so i can help .

**fon909** · 2011-05-20, 11:10 PM

Hi,

Its as simple as this, a 1 litre bottle cannot hold liquid of more than 1 litre weight. So this is not a miracle, please look for facts and calculations and check which throughput are you looking at, confirm the exact amount of E1s and no. of codes as well.

**jamalll2000** · 2011-05-21, 12:57 AM

The speed is not depending on the E1 it depending on the parameter setting including the QAM , MaxHsRate, Code and many more.

**agenov** · 2011-05-21, 02:07 AM

Originally Posted by jamalll2000

The speed is not depending on the E1 it depending on the parameter setting including the QAM , MaxHsRate, Code and many more.

many would preferred to not but infortunately there is straightforward relation.

BR

**anita_2k** · 2011-05-21, 03:24 AM

What happen in our case: NSN equipment

CASE1:

64QAM
IP IUB Capacity = 20mbps
Throughput ~14Mbps
IUB Utilization = 140%
w/ High CE Utilization (already FSME)

--> doubt to be formula related since only 1 site having above situation

CASE2:

2 E1
Throughput many sites with > 2 MBPS Tput

--> many sites having this situaion

maybe somebody else can share experience of their own.

br/Anne