Analysis Report of CE Congestion

Document Title Security Level

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 Cell Name

VS.RAB.FailEstabPS.ULCE.Cong

VS.RAB.FailEstabCS.ULCE.Cong

VS.RRC.Rej.ULCE.Cong

13032 Ntinda_Valley_2 173085 1810 6962613035 Ntinda_Valley_5 164729 2697 5758713037 Ntinda_Valley_7 129996 2767 4413913036 Ntinda_Valley_6 99508 1322 5665613033 Ntinda_Valley_3 85517 1581 2871013031 Ntinda_Valley_1 80464 994 28168

2023-04-17 Huawei Proprietary - Restricted Distribution Page1, Total10


12252 Kyebando_Nsoba_2 18449 188 625912256 Kyebando_Nsoba_6 16551 230 5624

9382 Kamukuzi_2 16256 112 69812257 Kyebando_Nsoba_7 15421 219 3794

3136 KAWAALA_ONE_6 14902 373 676112253 Kyebando_Nsoba_3 14818 225 3885

1871 Gulu_1 11872 180 9073132 KAWAALA_ONE_2 11127 178 5121

12255 Kyebando_Nsoba_5 11096 150 27579097 Bugonga_7 9069 144 4859

12251 Kyebando_Nsoba_1 9026 100 24369383 Kamukuzi_3 8218 98 3929093 Bugonga_3 8129 130 44131873 Gulu_3 7977 114 633

Top 20 of RNC1

CI Cell Name

VS.RAB.FailEstabPS.ULCE.Cong

VS.RAB.FailEstabCS.ULCE.Cong

VS.RRC.Rej.ULCE.Cong

13622 Nakabago_2 13034 294 227010126 Kireka_Caravan_6 5477 207 151910122 Kireka_Caravan_2 5407 168 1515

5435 First_Street_5 3095 159 122112965 IvoryPlaza_5 1105 154 36412966 IvoryPlaza_6 1222 150 35610085 HBTowers_5 1792 146 535

5336 MTN_Towers-6 891 140 28612186 Marie_Hotel_6 2669 134 93212962 IvoryPlaza_2 1162 134 29213623 Nakabago_3 7743 130 899

52 BugolobiRadioStation_2 1604 128 34612182 Marie_Hotel_2 2608 120 833

56 BugolobiRadioStation_6 1813 118 40212961 IvoryPlaza_1 1058 116 285

9176 Zzimwe_Rd_Muyenga_6 5212 116 23024385 Mbuya_Hill_5 2901 112 10162572 Nkoma_2 6226 110 4614615 UBC_5 1459 107 4369122 Katwe_2 3797 103 589



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

1.2 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:



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:



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.



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.



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









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%.

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.


Date post:	22-Oct-2015
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Analysis Report of CE Congestion

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