- This topic has 8 replies, 1 voice, and was last updated 10 years, 5 months ago by pix.
18th October 2010 at 20:56 #64725ALUGuest
I have one query regarding the max throughput achievable in a cell.Now, lets say we have good radio conditions so we can easily achieve highest throughput MCS9 from the start.Even in MCS Adaptation procedure, Mean_BEP and CV_BEP values indicate that new MCS should be MCS9. Now lets say that we dont have enough resources on the transmission side(we knw tht inorder to achieve MCS9, we need 5 abis nibbles corresponding to 1 TS), so provided that we dont have the required transmission resources, will we be still using MCS9 with lesser throughput or will there be MCS adaptation and we are switched to lower MCS schemes?If yes, then by which algorithm, its shifted to lower MCS?25th October 2010 at 20:32 #64726ALUGuest
Dear Pix(the original one :P),
Can you kindly shed some light on the above mentioned query aswell 🙂25th October 2010 at 20:48 #64727pixGuest
thanks for reminding me of your question. I’ll check the docs tomorrow (this is an algo that’s difficult to remember, i’m not sure i remember it correctly).15th December 2010 at 17:30 #64728ALUGuest
Back in school days, my teacher used 2 say tht “tomorrow never comes”…”so its always better to do ur tasks today rather than leaving it for next day”….now I hve learnt my lesson! Been waiting for ur reply since 1 Month 20 Days 14 Hours and 3 minutes but tht “Tomorrow” tht u promised me hasnt come yet 😛
Jokes apart, would u be kind enough to answer this query 🙂15th December 2010 at 19:38 #64729PixGuest
I wanted to give you time to find the answer, located in the internal “PRH” SYT documentation… 🙂
Well, I’ll tell you tomorrow then !
pix16th December 2010 at 14:36 #64730pixGuest
the max_mcs possible for the TBF’s in one TRX is computed depending on the number of GCH available.
If there are not enough GCH for that TRX, the max_mcs of that TRX is decreased.
nb_gch = 3 –> max MCS = 6
nb_gch = 4 –> max MCS = 7
nb_gch = 5 –> max MCS = 9
the MCS is then decreased per TBF depending on TBF radio quality, but it can’t exceed this max_mcs.
pix16th December 2010 at 21:01 #64731ALUGuest
Finally my wait is over 🙂 strange that in Alcatel documents under MCS Adaptation they never mention this(transmission resources) and only dependency on Radio Quality!
Thanx once again for ur time!2nd July 2011 at 14:19 #64732ALUGuest
I have another query in this regard. Does multiplexing in Radio Interface(radio TS) decrease the throughput(provided that the transmission resources are the same)? I mean take 2 different cases for MS having Multislot class(4+1).
Case 1: 2 MS are multiplexed on the same 4 PDCH(say Max_PDCH=4) but have full transmission resources(nb of GCH=5,MCS9)
Case 2: 2 MS allocated different PDCH(no multiplexing on radio interface Max_PDCH>=8) and having full transmission resources aswell(nb of GCH=5,MCS9).
Now will the throughput experienced by both the MS be the same in both the cases or will it be less for Case 1. If less then why?
Thanx and Regards2nd July 2011 at 16:00 #64733pixGuest
yes, it will be half, in case 1.
each MS can use a PDCH in only 1 occurence out of 2.
It’s like half-rate.
Instead of having 100% of the 4 PDCH, which is 59.2*4 kbps, each MS gets only, in average, 59.2*4 / 2.