- This topic has 13 replies, 1 voice, and was last updated 12 years ago by Pix.
16th March 2009 at 14:44 #56269BobGuest
I want to know what is the acceptable BLER for GPRS/EDGE and WCDMA18th March 2009 at 04:20 #56270PanGuest
Under BLER you are meaning Block Error Rate? If so, then BLER (or SDU error rate in GPRS) requirement are very dependent from used traffic class (or service type) and application requirements.18th March 2009 at 06:15 #56271PixGuest
In GPRS/EGPRS, there are different coding schemes, such as CS1 to CS4 in GPRS and MCS1 to MCS9 in EGPRS.
Each scheme provides a different useful throughput and a different protection ratio.
High tput with low protection or low tput with high protection.
As soon as the BLER becomes bad, the retransmissions rate increase… But then the link adaptation mechanism kicks in and the coding scheme is decreased, in order to provide more protection. The system choses to decreae the useful tput in order to give more protection.
As a direct consequence, the impact of bad BLER decreases. Retransmission rates are reduced, the receiver is able to decode the useful signal even under bad BLER conditions.
So you see, each coding scheme can accept a certain BLER. And this value for each CS can be found in 3GPP-something 🙂 (radio aspects I think)
Pan, our 3GPP master, what’s the ref number? 45 something? :))18th March 2009 at 09:27 #56272paraHOGuest
3GPP 45.00318th March 2009 at 12:38 #56273PixGuest
Incredible, this guy is a machine… :))
Thanks Pan 😉18th March 2009 at 13:35 #56274paraHOGuest
Your welcome Pix :-))))))19th March 2009 at 11:49 #56275PanGuest
Many thanks, my friends! By means of our common effort, we will touch bottom and get a synergetic effect :)) But I am understanding Bob’s question as follows:
What is the minimum requirement for error ratio of various applications. I.e. maximum error ratio that is acceptable for different applications. May be I am a bit mistaken:)19th March 2009 at 13:14 #56276pixGuest
I’m sure Bob’s gone. He was just here to entertain us with a question 🙂
Like a guy throwing a stick to entertain a dog. He doesn’t really care whether the stick is brought back or not….20th March 2009 at 16:14 #56277bobGuest
No pix don’t be so sure of your self that your are answering question suppose your self as gsm master mind and for your information I was busy with doc of paraho post thanks for your help.20th March 2009 at 21:51 #56278PixGuest
I don’t understand your previous message.
I suppose you’re thanking us ? In a weird way.21st March 2009 at 15:05 #56279PanGuest
Yes, Pix, I think he is thanking. He omitted exclamation points in his sentences. It sounds like:
No pix don’t be so!
[I am] Sure of your self!
You are answering question!
Suppose your self as gsm master mind!
and for your information I was busy with doc of paraho post. thanks for your help!
It is thanks certainly.21st March 2009 at 16:51 #56280PixGuest
And as the monthy python once sang:
“Always look at the bright…
…side of your life
tu tudu tidudidudidu”21st March 2009 at 22:01 #56281bobGuest
No pan thanks is no for pix it is for paraho as i check some of his answer from posts he like to make fun of what are posted and one thing else for mr pix i think you become older and has no patient.22nd March 2009 at 10:25 #56282PixGuest
ParaHO > Sorry, i thought you were PAN… sorry for the mistake.
Bob > Ok… but please, before I loose your friendship forever, notice that my “technical” answer is totally answering your question, and is very respectfully written. Furthermore, it pointed you to the right 3GPP doc.