- This topic has 14 replies, 1 voice, and was last updated 9 years, 5 months ago by pix.
16th July 2011 at 03:56 #66793TTGuest
Hi everybody, i have some question but i donnot how to answer. Please help me.
Why is the MS Class 4 33 dBm? How to calculator? Please explain to me clearly.
Thank for your help.18th July 2011 at 01:57 #66794TTGuest
Somebody help me?18th July 2011 at 07:57 #66795pixGuest
Ms class 4 = 33dBm.
It is not a computation, it is a table. Check out TS45.005, chapter 4.1.1.
pix18th July 2011 at 08:30 #66796TTGuest
Thank you pix, but i donnot see chapter 4.1.1 in the webpage. I only see version 4.0.0, 4.1.0, 4.2.0, … Can you show it for me?
I really want to know how they do that? why is MS Class4 33 dBm? Can you explain it to me?
Thank you very much.
TT.18th July 2011 at 16:41 #66797pixGuest
it seems you are not familiar with navigation in the 3GPP. In the webpage, you see all “versions” of this document (version 4.1.0, version 5.x, version, 6, 7, etc).
choose the latest version : 10.0.0
this downloads the .zip on your computer.
In this zip, there is a word document.
go to chapter 4.1.1
With all due respect, your question is pointless, as far as i understand it. It is like asking “why 10+2 = 12”
It is just a convention, defined in this document. The MS Max Tx Power can be 33dBm, or 36dBm, or 39dBm, etc. Each max tx power corresponds to an “ID”, which is called a “class”.
I’m afraid I didn’t understand your question though.. feel free to explain 😉
pix19th July 2011 at 01:31 #66798TTGuest
Thanks pix, can you give me your email to discuss this problem? my email is firstname.lastname@example.org
TT19th July 2011 at 01:52 #66799TTGuest
Hi, Pix. I find in word document (version 10.0.0) but i donnot see 33 dBm? where does focus it?
I have a question must to answer, it is very necessary. I have a week to answer it but up to now i still cannot answer: “why is MS Class4 33 dBm? Explain it in your way.” You can understand it this way, but you can also understand it in other way. Though on what way, you must explain it convincingly.
I am sorry about my English, because it is not good, so you may try to understand, please.
TT19th July 2011 at 10:56 #66800pixGuest
the only answer is that “it is defined this way in 3GPP TS45.005, chapter 4.1.1”
there is no “other way”.
class 4 means 33dBM. That is the sole and only definition of class 4.
If they had called it “brown sugar on fingers” instead, then that would be how we call MS whose txpwr=33dBm. And “class 4” would not exist.
pix27th July 2011 at 04:46 #66801TTGuest
Hi, pix. I cannot still answer that question.
I think it has a threshold. When a MS stand near by BTS, MS will transmit a limited power, and the maximum power in this case is 33 dBm. Because if you transmit more than 33 dBm, BTS will receive a signal with higher BER, it isnot realibility. But i cannot explain it convincingly because i havenot any information about it and may be, it has a figure obout BER vs MS Tx Power.
Please help me.
TT27th July 2011 at 13:54 #66802pixGuest
ok, now you are talking about power control.
the class 4 says that the MAX power of the ms = 33dBm.
If the MS is very near the antenna, its power can be decreased down to 5 or 6dBm only !
But if the MS goes further away, the power will then increase : 10dBm, 12 dBm, …. up to … 33dBm.
You are right, the power is reduced when the BTS receives an execllent signal from the MS (good BER) – gradually.
But if the signal is too bad (bad BER), then the BTS asks the MS to increase its tx power – gradually, again.
The MS Tx power varies between 5dBm up to 33dBm.
pix28th July 2011 at 04:41 #66803TTGuest
Hi pix. Thank you about your information.
But my senior asks me that question and required me to answer it in boundary condition. That means you must answer why the maximum TX power is 33 dBm, when MS stay near BTS, if you transmit more than 33 dBm, the BTS will receive unrealibility signal. So 33 dBm is a threshold. And you must find out why 33 dBm is a threshold.
In fact, i donnot know how to answer that question but he want me to answer it, i donot know what i should do. Please help me.
TT28th July 2011 at 12:04 #66804pixGuest
when the MS is near the BTS, the MS power will be 5dBm. Not 33dBm.
Except at call setup, for few seconds, during which the power control is inhibited. Then, the power control kicks in and the MS power decreases as much as possible.
The MS class 4 can NEVER exceed 33dBm. Why did you say “if the MS transmits more than 33dBm…” ???
Now if you have a MS class “x” that transmits 39dBm, the BTS will still be able to decode the signal. There is not unreliability signal. This does not exist.
Either you did not understand the question, or your senior doesn’t know what he’s talking about. Get another senior…
pix29th July 2011 at 01:52 #66805TTGuest
I donnot what should i do now. I cannnot answer that question because like you talked, it seem a truth, cannot explain. But he want me to explain, :((
Can you tell me about Minimum Coupling Loss (MCL)? What is MCL used for?
TT4th August 2011 at 04:46 #66806TTGuest
Somebody help me, plese.6th August 2011 at 05:53 #66807pixGuest
MCL : i forgot the details about this, I’m sorry.. so here is what I recall :
it is the minimum distance between MS and BTS antenna, converting in to “dB”.
3GPP assumed the minimum distance BTS-MS is 2 meters, in indoor scenario. That equals to 45dB (when using okumura, i believe)
Now the main idea is to avoid the MS to send a signal too STRONG into the BTS Rx antenna, because otherwise it might feedback to the Tx side.
This can easily be avoided by applying UL Power Control.