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18th November 2009 at 06:01 #59680fedGuest
guys, need your input on this, i have the IMSI ID and i tried to calcultate the paging group using that IMDI mod 1000 formula but couldnt get the logical result, can you please help how to calculate this?
18th November 2009 at 06:41 #59681BinitGuestHi Fed,
Just 3 Parameters:-
1)ccch_conf
2)bs_ag_blk_res
3)bs_pa_mfrmsIn 51-Frame Multiframe, total 9 CCCH blocks are available.
(1)ccch_conf : 0/1
0 means combined Multiframe (TotalCCCH blocks=9)
1 means non-combined Multiframe. (Total CCCH blocks=3)
(2)bs_ag_blk_res: No of blocks reserved for AGCH.
(3)bs_pa_mfrms :no of 51 frame multiframe between transmission of paging messages to MS of same group.Now see the calculations how MS uses these 3 parameters for calculating its PAGING GROUP.
FORMULA:-
(IMSI mod 1000) mod{ (ccch conf – bs ag blk res) * bs_pa_mfrm }
EX:-
1)ccch_conf=0
2)bs_ag_blk_res=1
3)bs_pa_mfrms=2
LETS SAY IMSI / TMSI:- XXXXXXXXXXXXXXX
i.e. (XXXXXXXXXXXXXXX mod 1000) mod{ (9- 1) * 2}18th November 2009 at 10:24 #59682fedGuestthnx Binit for your response, actually its the formula basically which is creating all the confusion. I understand this but how to calculate it in excel e.g. if my IMSI ID is 006236488199771 and with non combined 9 CCCH configuration with 8 PCH and 1 AGCH blocks and the value of number of mltiframes between paging is 3 then what would be the result as per your calculation? because when i right =MOD(IMSI ID, 1000) it give #N/A …:(.. dont understand what i am doing wrong.
My other query, we were facing severe paging deletions in some of our LACs, we did the trial recently and by reducing the parameter value of “numberOfMultiframesbetweenPaging” from 6->3 we observed tremendous improvement in paging deletions, how? and what could be adverse affects of this change (if any) other than shorter battery life time? and how can we quantify that?
18th November 2009 at 11:45 #59683BijoyGuestFed
That is the limitation of excel
Rather try this formulae
MOD(n, d) = n – d*INT(n/d)A high value of “numberOfMultiframesbetweenPaging” will lead to more paging groups in the cell
Hope you got the clue
Br\\
Bijoy18th November 2009 at 13:29 #59684fedGuestwhat about my other query? 🙂
My other query, we were facing severe paging deletions in some of our LACs, we did the trial recently and by reducing the parameter value of “numberOfMultiframesbetweenPaging” from 6->3 we observed tremendous improvement in paging deletions, how? and what could be adverse affects of this change (if any) other than shorter battery life time? and how can we quantify that?
19th November 2009 at 06:08 #59685BijoyGuestFed
Nothing much to loose with low MFRMS settings.
Few concerns
1.For cells with high paging load it’s recommended to keep MFRMS between 4 to 6.
2.Might lead to slight increase in interference due to small DRX period.
3.BSC/MSC load may slightly increase.
i think you didn’t follwed my clue:-)
Br\\
Bijoy19th November 2009 at 06:16 #59686AliAsgherGuestDear Bijoy,
Dont you think a low value of MFRMS (perhaps 2) will reduce the paging discards due to Full Paging Queue??
It is normally very effective in reducing the paging discards by lowering MFRMS.
19th November 2009 at 07:30 #59687BijoyGuestAli
Everything has its own merits & demirts.Its us who decide what we can tolerate & what not.
Regarding your query,
One “Paging Queue” per “Paging Group” is available at the cell level (that means when we decrease the number of paging groups for the cell by reducing MFRMS to lower numbers, we actually reduce the number of available paging queue).
Also
Paging Queue Length = 14 – (Number of Paging Groups/10); which means higher the number of paging groups in a cell (that is higher the MFRMS settings), lower will be the Paging Queue length, this will compensate for lower number of Paging Queue available at lower MFRMS.I’m not against any kind of MFRMS setting:-)
Fed,was asking for other demirts of low MFRMS,I just pointed out some.19th November 2009 at 15:34 #59688AliAsgherGuestThanks Bijoy. Brother I wonder how many vendors have you worked with. I have read your posts regarding E///, Huawei, Nokia.
19th November 2009 at 21:40 #59689PixGuestBijoy,
Thx for all the info. Could you explain your “clue” ? I didn’t get the point…
Cheers,
pix20th November 2009 at 04:57 #59690BijoyGuestPix
That was for not for you.:-)
The clue was for how he got improvement in paging discard by lowering the MFRMS.
Ali
I think You can add 2 more,Motorola & ZTE:-).20th November 2009 at 10:31 #59691PixGuestBijoy,
clue is not for me, but I’m asking for it 😉
Bijoy, Ali, Fred
Notice that thanks to Bijoy, we know that :
Paging Queue Length = 14 – (Number of Paging Groups/10)(if MFRMS is high, the nb of paging groups is high)
If MFRMS between 1 & 9 (typical values !), the size of each queue is equal to 13. The impact of the Bijoy’s formula is actually very limited !
So increasing the number of groups will indeed increase the number of requets that can be queued.
However, it seems that decreasing the MFRMS is enhancing the QoS. Why ??
Any idea ?
(post 1)20th November 2009 at 11:43 #59692BijoyGuestPix
I didnt get you.
No. of paging groups=MFRMS*(9-AGBLK),So paging queue lenth can be greater than 13 also.20th November 2009 at 12:06 #59693BijoyGuestPlease ignore my previous post.
Pix
No.of paging groups = MFRMS(9-AGBLK),for non-combined BCCH
So.how r u saying that?20th November 2009 at 12:24 #59694PixGuestso let’s see.
Assumptions:
MFRMS = 2
AGCH Blocks = 4
Results:
Nb of paging groups = 2 * 5 = 10
Paging Queue size = 14 – 10/10 = 13Assumptions:
MFRMS = 6
AGCH Blocks = 4
Results:
Nb of paging groups = 6 * 5 = 30
Paging Queue size = 14 – 30/10 = 11Sorry, it is not equal to 13, but it stays within a rather high range. So increasing the number of paging groups is a good way to increase the overall queuing capacity of a cell.
1st example : 10 groups with each a queue of size 13 : 130 request can be queued.
2nd exampe : 30 groups with each a queue of 11 : 330 requests can be queued.What do you think ?
Second question : why, when fred decreased the MFRMS, the paging deletions decreased? It seems unlogical.
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