LAC Dimension Ing Report C-2 July

ALCATEL-LUCENT PAKISTAN LIMITED || PPS Study and LAC Re-dimensioning Report 1

5th July, 2010

PPS and PSR Study & Lac Re-dimensioning Report Central-II


1. Summary This report aims at study of PPS in LACs of Central II region and monitoring the impact of high PPS on PSR of certain LACs. LAC re-dimensioning recommendations are given accordingly after a comprehensive study of PPS and PSR. Data collection period is from 19th to 28th Jun 2010. The report has been divided into two Parts

1.1 PPS and PSR study of Central-II LACs: First part of the report consists of calculating maximum PPS of all LACs in ALU responsibility area and then finding out PSR of only those LACs whose PPS exceeds Max PPS threshold of 45 Pages/second.

1.2 LAC Re-dimensioning Proposals Central-II LACs

LAC re-dimensioning / LAC Merger recommendations are given keeping in view the below mentioned points

� The candidate LACs must be adjacent to each other � The candidate LACs must have Max_PPS under the threshold (45 Paging/ Sec)

however this threshold need to be revised because even at high PPS i.e. at 50 Paging / Sec some LACs still have acceptable PSR (>70%)

� After merging the LACs, the new LAC should be having good PSR (> 70% for remote LACs and >80% for City )

� LACs having the same MSC are preferred for merger � PSR is calculated according to following formula:

PSR = ∑ (MC01 of all cells of LAC)/ (Max MC8a of all cells of LAC) * 100


Part-1 PPS and PSR Study Central-II


1.1- Scope: The aim of the working is to monitor the PPS and PSR trending on Central II LAC’s and also to observe the effect of increased PPS on the PSR (paging success rate). 1.2- Maximum PPS calculation of All LACs: A trend of MAX_PPS/ day for 10 days [19th Jun to 28th Jun] was prepared for all the ALU monitored Central-II LACs 27 that include 59 BSC’s. For each LAC, PPS was calculated for all the hours of the day and then the highest value of PPS was selected among all the intervals. The MAX_PPS trending of each LAC is shown below.


1.3- PSR Study of High PPS LACs: In this phase, LACs exceeding a certain PPS limit were selected so that their PSR can be calculated on LAC level to point out any degradation. The threshold of the PPS is selected on the basis of below calculation. BS_AG_BLKS_RES [No of CCCH Blocks reserved for AGCH]= 2 on the basis of which Um Interface limitation for non combined cells is calculated as follows. There are 9 CCCH blocks per 51 frame multi frame so (9 - BS_AG_BLKS_RES) blocks are used for paging which in our case is equal to 7. In our scenario, Available paging blocks / hour = (7*3600)/0.235=107234 blocks / hour Max Paging per hour [100 % load] = 2.5 * 107234 = 268085 paging / hour Max paging per second [100 % load]=74.468 paging per second Max paging per second [60 % load] =44.68 paging per second (recommended) Based on the above threshold, high PPS is observed for the following LACs. Corresponding BSCs and area classification are also given for reference.


BSC NAME LAC

Number

Of Cells Region

FSD706E__Sahil4 403 33 City


FSD949E__ZiaTwn9 403 36 City


OKR718E__BPark_2 413 39 City

OKR719E__Chenab2 413 60 C-II remotes

OKR845E__Okara_2 413 68 City




SGD617E__Rafiq4 820 215

City +

Remotes

PKP548A__AlfalahBank 864 31 C-II remotes

PKP549A__Addanoorpur 864 56 C-II remotes

PKP645E__McaCola 864 88 C-II remotes

ARW539A__PKPRoad_1 868 44 C-II remotes

ARW540A__PKPRoad_2 868 49 C-II remotes

ARW591E__Tikka 868 67 C-II remotes

1.4- LAC with PPS >45


Hourly PSR was calculated from 19th Jun to 28th Jun for the 6 LACs with the help of below mentioned

formula.

For a specific hour (e-g 0600) PSR = [(Sum of MC01 of all the cells in the LAC at 0600) / (Max value of

MC8A in the LAC at 0600)]*100.

� For LAC 403, PSR is around 85 % with MAX_PPS around 45 Paging/Sec


� For LAC 413, PSR is above 80 % with PPS around 45 Paging/Sec:


- For LAC 425, PSR is round 87 % with MAX_PPS around 48 Paging/Sec.

-


� For LAC 820, current PSR after migrations is above 80 % with MAX_PPS around 46 Paging/Sec


� For LAC 864, PSR is round 72 % with MAX_PPS around 52 Paging/Sec.


- For LAC 868, PSR is round 80 % with MAX_PPS around 48 Paging/Sec.


Part-2 Lac Re-dimensioning Proposals Central-II


2.1- Candidate LACs :

Below is a table of all Central-II LACs that are suitable candidates for merger

Source LAC Source Msc Destination LAC Destination Msc Proposed LAC

417 NSN03MGW01FSD 437 NSN03MGW01FSD 417

426 NSN06MGW5BFSD 407 NSN06MGW5BFSD 407

The above mentioned LACs have been selected depending upon their geographical location i.e. all these

LACS are adjacent and suitable for merger and are served by same MSC. Expected PPS may go beyond

45 after LAC merger. However it is already noticed that even at higher value of PPS, i.e. at 50 Paging/Sec,

some LACs still have good PSR (>70%).


2.2- LAC Merger_417 & 437: LACs 417 & 437 contain three BSC’s. Although combined Max_PPS is around 48 pages/Sec yet PSR after merging these two LACs is touching 80%.

Source LAC Source Bsc Source Msc Destination LAC Destination BSC Destination Msc

417 CHN636E__Mustafa2 NSN03MGW01FSD 437 FSD702E__Sahil2 NSN03MGW01FSD

NSN03MGW01FSD 437 FSD878E__ZiaTwn7 NSN03MGW01FSD


� Current Boundary Of LACs:

� Boundary after Merger Of LACs:


2.3- LAC Merger 407 & 426: LACs 407 & 426 contain three BSC’s. Value of Combined Max_PPS is above 45 pages / Sec. However PSR after merging these two LACs is 85%

Source LAC Source Bsc Source Msc Destination LAC Destination BSC Destination Msc

407 FSD998E__ZiaTwn12 NSN06MGW5BFSD 426 FSD104E__ZiaTwn14 NSN06MGW5BFSD

426 FSD118E__ZiaTwn18 NSN06MGW5BFSD


� Current Boundary Of LACs:

� Boundary after Merger Of LACs:


Conclusion

� PPS for most of Central-II LACS is below 45 paging/sec except afore mentioned 6 LACs.

� PSR of all the CII LACs is above 70%.

� Also the PSR of the city LACs was found to be much better than remote LACS.

� No degradation in the PSR was observed even when the MAX_PPS on LAC level reached 50

PPS.

� Two LAC mergers have been proposed for LACs having comparatively low PPS. After merging

the adjacent LACs, expected PSR is found to be in the acceptable range though PPS has

exceeded 45.

� The merging of LACs will reduce location updates which in turn will be helpful for reducing the

SD blocking. The efficiency in the core will also be enhanced as now the signaling load on A-

interface will be less due less location updates.


END OF Document

LAC Dimension Ing Report C-2 July

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