- This topic has 9 replies, 1 voice, and was last updated 9 years, 1 month ago by Thiagu.
3rd November 2010 at 07:11 #64882Junior RF ManGuest
If BSC makes decision for performing Power Control on uplink (MS PC) and it should send some message through Um interface to MS for starting power control.
What is the name of this message? Is it coming on the System Information messages, if yes on which
SI message is it?3rd November 2010 at 12:32 #64883PixGuest
There is no message to signal the start of PC.
It is all up to the BSC, the MS doesn’t have to know anything.
As soon as PC is enabled, the BSC will start sending power control orders to MS and BTS.
The power control orders is not really an order : it is just that instead of telling the MS to transmit at 33dBm (for ex.) it will say “30dB” or “28dB”, etc.
By default, with PC disabled, the BSC always transmit the value 33dBm.
To the BTS, for the DL PC, it says “0dB”, which means the BTS should attenuate its tx power by 0dB.
I hope i was clear… hum…
pix3rd November 2010 at 14:11 #64884Junior RF ManGuest
It means, in the layer 3 messages we can see MS_TX_PWR_MAX (33, 30, 28…) during the power control. Yes or not?3rd November 2010 at 14:41 #64885fedeGuest
there is also the pwrc bit (power control indicator) within Cell Options (SI3)3rd November 2010 at 17:44 #64886fedeGuest
the ordered PC level from BSS is in the L1 header3rd November 2010 at 19:37 #64887pixGuest
yes, it’s in layer 1.
the pwrc refers to the measurement process rather than the power control process (check 3GPP TS 45.008, look for pwrc)
pix3rd November 2010 at 21:34 #64888fedeGuest
hi pix, thanks a lot!
I did misunderstand the meaning of pwrc bit.4th November 2010 at 05:24 #64889Junior RF ManGuest
So I can not see MS PC Adjustment on TEMS Investigation. Right?4th November 2010 at 09:20 #64890SHELDONGuest
On the downlink SACCH, the BTS sends the MS a power order, which informs the MS as to which power to transmit on. When MS power control is activated in the cell, the power order can ‘instruct’ the MS to transmit on a lower or higher power.
In TEMs, you can’t see the SACCH message, but you can see the current ‘MS Power Control Level’ the GSM Radio Parameters window. The values given there are in multiples of 2, so eg, if the power control level is 3, the MS should transmit 6dB below the maximum power.
SHELDON8th March 2012 at 14:13 #64891ThiaguGuest
Is that Means with PC Disabled MS will Transmit at Max Power?