Analysis Report of CE Congestion

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Analysis report of CE Congestion CE congestion is one of the major reason for blocked calls, so it is very important to get a clear picture of the CE situation for the whole network.

Table of Contents 1

CE Status Review ............................................................................................................. 1

1.1

Statistics ....................................................................................................................... 1

1.2

Analysis ........................................................................................................................ 3

2

Solution of CE Congestion ............................................................................................. 10

2.1

Increase CE capacity .................................................................................................. 10

2.2

Switch off HSUPA 5.76mbps service ........................................................................ 10

2.3

Switch off dynamic CE function ................................................................................ 10

1 CE Status Review 1.1

Statistics Let’s review the statistics of last week, which is from 12th Aug to 18th Aug. Top 20 of RNC2

CI 13032 13035 13037 13036 13033 13031 12252 2014-01-29

Cell Name Ntinda_Valley_2 Ntinda_Valley_5 Ntinda_Valley_7 Ntinda_Valley_6 Ntinda_Valley_3 Ntinda_Valley_1 Kyebando_Nsoba_2

VS.RAB.FailEst VS.RAB.Fai abPS.ULCE.Co lEstabCS.U VS.RRC.Rej.ULCE ng LCE.Cong .Cong 173085 1810 69626 164729 2697 57587 129996 2767 44139 99508 1322 56656 85517 1581 28710 80464 994 28168 18449 188 6259

Huawei Proprietary - Restricted Distribution

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12256 9382 12257 3136 12253 1871 3132 12255 9097 12251 9383 9093 1873

Kyebando_Nsoba_6 Kamukuzi_2 Kyebando_Nsoba_7 KAWAALA_ONE_6 Kyebando_Nsoba_3 Gulu_1 KAWAALA_ONE_2 Kyebando_Nsoba_5 Bugonga_7 Kyebando_Nsoba_1 Kamukuzi_3 Bugonga_3 Gulu_3

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16551 16256 15421 14902 14818 11872 11127 11096 9069 9026 8218 8129 7977

230 112 219 373 225 180 178 150 144 100 98 130 114

5624 698 3794 6761 3885 907 5121 2757 4859 2436 392 4413 633

Top 20 of RNC1

CI 13622 10126 10122 5435 12965 12966 10085 5336 12186 12962 13623 52 12182 56 12961 9176 4385 2572 4615 9122

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Cell Name Nakabago_2 Kireka_Caravan_6 Kireka_Caravan_2 First_Street_5 IvoryPlaza_5 IvoryPlaza_6 HBTowers_5 MTN_Towers-6 Marie_Hotel_6 IvoryPlaza_2 Nakabago_3 BugolobiRadioStation_2 Marie_Hotel_2 BugolobiRadioStation_6 IvoryPlaza_1 Zzimwe_Rd_Muyenga_6 Mbuya_Hill_5 Nkoma_2 UBC_5 Katwe_2

VS.RAB.FailE stabPS.ULCE VS.RAB.FailEsta VS.RRC.Rej.ULC .Cong bCS.ULCE.Cong E.Cong 13034 294 2270 5477 207 1519 5407 168 1515 3095 159 1221 1105 154 364 1222 150 356 1792 146 535 891 140 286 2669 134 932 1162 134 292 7743 130 899 1604 128 346 2608 120 833 1813 118 402 1058 116 285 5212 116 2302 2901 112 1016 6226 110 461 1459 107 436 3797 103 589


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For details of the whole network, please refer to attached.

1.2

CE Congestion.xlsx

Analysis For all the CE congestion shown above, they can be divided by three categories: 1. Real CE Congestion Ntinda_Valley This site had a real high CE utilization and need CE upgrade:

Even Kyebando_Nsoba, the same problem:

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For this kind of sites, the solution is easy – upgrade CE. 2. Fake CE Congestion

There are still another kind of sites, whose CE utilization isn’t high at all, but still has UL CE congestion, such as site Entebbe_Airport_Inbuilding: CE Utilization is very low:

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While CE congestion existed:

This is the issue of the counters related to CE congestion, such as FailCSRAB.ULCE.Cong, FailPSRAB.ULCE.Cong. Let’s take FailCSRAB.ULCE.Cong for example: 1. There are three cells in active set: Cell A, B, C, and cell A is the dominant cell. 2. Now Cell B has UL CE congestion and then CS RAB is failed because of it. 3. But from statistics, we will see cell A-the dominant cell, has FailCSRAB.ULCE.Cong, while Cell B is OK. So for CE congestion issue, we should not only consider the cell itself, but also neighboring cells.

This statistics problems cannot be solved now, but you can refer to these two counters to verify if congestion really exists: 1. RLM.FailRLSetupIub.Cong, always 0, which means no any congestion.

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2. VS.IUB.FailRLRecfg.Cong, also 0 eveytime.

Then Entebbe_Airport_Inbuilding had no any congestion.

3. Something like category 2, but it’s real CE congestion Many sites belong to category 3, such as Kamukuzi, the CE utilization is not high while UL CE is congested.

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As analyzed above, we use VS.IUB.FailRLRecfg.Cong and RLM.FailRLSetupIub.Cong to evaluate the real CE congestion, and it is really congested: Sector 1- VS.IUB.FailRLRecfg.Cong

Sector 1- RLM.FailRLSetupIub.Cong

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Sector 2- VS.IUB.FailRLRecfg.Cong


Sector 3- VS.IUB.FailRLRecfg.Cong

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So why is it like this?  CE utilization is measured in NodeB level when switched on Dynamic CE function. While CE congestion is measured in RNC, which doesn’t know how NodeB schedules CE based on Bynamic CE function, and RNC just judges CE resource based on GBR admission, such as one HUSPA user, reserve 16 CEs, 3 users, 48 CEs reserved, even though these CEs are not consumed in NodeB level.  Then we can see from NodeB level, a lot of CEs(48) are left, but on RNC, congestion has happened, as the remaining 48 CEs have been reserved.  So if we switch off Dynamic CE function on NodeB, which means NodeB won’t release CE automatically, CE utilization will reflect real CE utilization. Such as the site Kamukuzi, we will see the CE utilizaion almost 100%. 2014-01-29


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2 Solution of CE Congestion 2.1

Increase CE capacity

2.2

Switch off HSUPA 5.76mbps service As 5.76mbps need higher GBR, more CEs need to be reserved and then congestion happened easily.

2.3

Switch off dynamic CE function 1. NodeB gave real consumed CEs within 2ms, while RNC get the statistics from admission GBR for HSUPA in 5ms, even though the consumed CE was far less than physical CE capacity, CE congestion could happen from RNC statistics(RAB failures due to CE congestion). 2. When Dynamic CE function is on, HSUPA DCCC will be invalid, and RNC will use GBR for admission. 3. When dynamic CE function was switched off, HSUPA DCCC will take effect, through which RNC can give admission for user with initial speed, not GRB, and thus blocked calls will reduce a lot.

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Analysis Report of CE Congestion

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