- This topic has 14 replies, 1 voice, and was last updated 9 years, 9 months ago by pix.
14th April 2010 at 08:09 #62128janeGuest
Can anyone explain to me this parameter? I can’t seem to find a documentation about this.
Thank you.14th April 2010 at 11:55 #62129BijoyGuest
This parameter specifies the maximum countdown value of the MS.
This parameter determines BS_CV_MAX and is used for the MS to calculate the CV. The parameter also determines the duration of the T3198 timer.
Every time the MS sends an uplink RLC data block, the receive state of the data block is set to Pending and the T3198 is started. If the MS receives a Packet Uplink Ack/Nack message before T3198 expires, it updates the receive state of each uplink RLC data block based on the acknowledgment bitmap contained in the message. If T3198 for the RLC data block in the Pending state expires, the MS sets the receive state of this data block to Nack and retransmits the data block.15th April 2010 at 06:16 #62130ManiaGuest
What is the usual value ot BS_CV_Max and what is it normally based on.15th April 2010 at 09:24 #62131BijoyGuest
If the value of this parameter is set to a modest value, the MS may retransmits the RLC data block before the BSC sends an Uplink Acknowledgment message. Thus, many radio resources are not used but occupied.
If this parameter is set to an excessive value, the speed of the sliding window decreases and the probability of the uplink TBF transmission countdown increases, thus decreasing the performance of uplink transmission.
To make this value more accurate, you need to estimate the delay in the transmission between the MS and the BSC first. This value is set based on the transmission delay.
Bijoy26th November 2010 at 14:23 #62132MohitGuest
Hi.I get BS_CV_MAX value from Sys_info13 message. But still not get CV value.
(1)Is both BS_CV_MAX & CV same?
(2)If not where we get Countdown Value(CV)?29th November 2010 at 06:57 #62133BijoyGuest
1.The MS shall send the Countdown Value (CV) in each uplink RLC data block to indicate the current number
of remaining RLC data blocks for the uplink TBF.
x=round((TBC-BSN-1)/(NTS x S))
then CV=x ,if x=< BS_CV_Max or CV=15,if x> BS_CV_Max
TBC=total number of RLC data blocks currently to be transmitted in the TBF.
BSN=Block sequence no. of the RLC
NTS=number of timeslots assigned to the uplink TBF
2.I think you can check the CV value in the UL mode reports.
Bijoy30th November 2010 at 14:38 #62134MohitGuest
Thanks Bijoy. I will check and confirm that.22nd July 2011 at 11:25 #62135b2002Guest
Now am studying the RLC/MAC. May i thought u know about the that protocol…
Can u explain for me..?22nd July 2011 at 14:24 #62136PixGuest
To make it better, tell us in how many words you want that…
But why not have a look at this first?
etutorials.org/Mobile+devices/gprs+mobile+internet/Chapter+5+Radio+Interface+RLC+MAC+Layer/25th July 2011 at 10:32 #62137b2002Guest
Thank u for reply.
i studied that book.i have lot of doubts.That is reason am asking the explanation.25th July 2011 at 12:02 #62138PixGuest
What are your doubts? It’s more efficient if you do an effort in writing a long question, rather than us second-guessing whih part of RLC/MAC is troubling you.
It is a huge protocol.
pix25th July 2011 at 13:56 #62139b2002Guest
my doubt is when RLC/MAC is one phase acess and when is two phase acess?25th July 2011 at 14:05 #62140pixGuest
1 phase access when the MS is planning to send less tha 8 RLC blocks – it asks for 1 PDCH only.
2 phase access when the MS is planning to send more than 8 RLC blocks, or when it is planning to use EGPRS, as far as i remember – it sends its multislot configuration so that the PCU can allocate as many PDCH as possible for the MS.
In both cases, it is up to the MS to decide whether to do 1 or 2 phase access.
There are other constraints to do a 1 or 2 phase access, but I forgot them (RLC ack or unack mode, EGPRS modulation, etc etc)
But the principle is the same.
Big transfer = 2 phase
Tiny transfer = 1 phase
Decision’s criteria are hard coded in the MS.
pix26th July 2011 at 05:52 #62141b2002Guest
thanks for explanation.But when we know about the RLC/MAC is Less then 8 blocks?
b200226th July 2011 at 11:07 #62142pixGuest
well, we don’t know, but the MS knows how much data needs to be transmitted.
If the user has just switched on the phone, the MS has to send a GPRS ATTACH, which is = nn bits = k RLC blocks (values which are known by MS)
if the user is uploading a file, then the MS knows the size of the file, so it will see that it is more than 8 RLC blocks.