04 Air Interface Optimization

8/16/2019 04 Air Interface Optimization

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Soc Classification level

1 © Nokia Siemens Networks RN31574EN30GLA0

Air interface optimization

3G RANOP RU30


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Course Content

KPI overview

Performance monitoring

Air interface optimization

Traffic Monitoring

Capacity Enhancement


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At the end of the module you will be able to:

• Describe techniques for interference and neighbour analysis

and interference reduction

• Discuss techniques for coverage monitoring and enhancement

• Understand techniques for slow fading analysis

• Describe techniques to monitor and improve CQI

• Describe how to improve neighbour plan with NSN Optimizer

Tool

Module Objectives


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Interference monitoring and reduction

Overview

Ec/Io

Little I

Pilot pollution - cell matrix

Propagation delay - positioning

SHO delay

Coverage monitoring and enhancement

Slow fading analysis

CQI monitoring and improvement (HSDPA)

NSN Optimizer Tool (appendix)

Air Interface Optimization


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Power

(dBm)

Ec/Io = RSCP / RSSI

Indicates total amount of interference in a cell

Decreases from cell centre towards cell edge

distance

Ec/Io

Ec/Io

RSCP

RSSI

Interference monitoring – Ec/Io


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RSSI

cell 1

cell edge

power of neighbours

dominate

cell centre

power of server

dominates

„i“ = 0.3 „i“ = 1.0

cell 2

Little i = adjacent cell interference / own cell interference

Indicates overlap of cells due to their total DL power

Increases from cell centre towards cell edge

Interference monitoring – little i


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RSCP

cell 1

cell edge

neighbouring CPICH

dominate

cell centre

serving CPICH

dominates

cell 2

Pilot pollution = total adjacent cell RSCP / own cell RSCP

Indicates overlap of cells due to their CPICH power

Increases from cell centre towards cell edgeDominance of neighboring CPICH usually consequence of SHO problem

Interference monitoring – pilot pollution


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Overview

Ec/Io

Little I



SHO delay







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Ec/Io indicated by the following RRC messages

Connection request serving cell only whole cell area coveredCell update serving cell only cell edge (cell update) only

Event 1A report all measured cells cell edge (SHO) only

Event 1B report all active cells cell edge (SHO) only

Event 1C report all active cells and better neighbor cell edge (SHO) only

Event 1E report all active cells cell edge (HHO) only

Event 1F report all active cells cell edge (HHO) only

Ec/Io monitoring – RRC messages

UE BS RNC

Connection request

Cell update

Event 1A…1F report


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New RU30 counters M1033C0…M1033C9

Number of connection requests falling into specific Ec/Io interval

Updated in serving cell

Ec/Io ≥ -2 dB

-2 dB > Ec/Io ≥ -4 dB

-4 dB > Ec/Io ≥ -6 dB

-6 dB > Ec/Io ≥ -8 dB

-8 dB > Ec/Io ≥ -10 dB

-10 dB > Ec/Io ≥ -12 dB

-12 dB > Ec/Io ≥ -14 dB

-14 dB > Ec/Io ≥ -16 dB

-16 dB > Ec/Io ≥ -18 dB

-18 dB > Ec/Io

Ec/Io monitoring – connection request


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Practical example – RNC cluster


Number of cells versus median Ec/Io

Red = 2 GHz Green = 900 MHz

HHO Ec/Io

threshold

Typical

target

Somewhat lower Ec/Io

for the 900 MHz band


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Practical example – single cell of average performance (2 GHz)


Number of connection requests versus Ec/Io

HHO Ec/Io

thresholdTypical

targetWhole cell area

Most calls setup under

acceptable conditions

Few calls setup under

bad conditions

Very seldom call setup

in HHO area


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Counters M1007C38…M1007C47

Number of Event 1A reports falling into specific Ec/Io interval

Updated in best active cell

Ec/Io ≥ -5 dB

-5 dB > Ec/Io ≥ -10 dB

-10 dB > Ec/Io ≥ -12 dB

-12 dB > Ec/Io ≥ -14 dB

-14 dB > Ec/Io ≥ -16 dB

-16 dB > Ec/Io ≥ -18 dB

-18 dB > Ec/Io ≥ -20 dB

-20 dB > Ec/Io ≥ -22 dB

-22 dB > Ec/Io ≥ -24 dB

-24 dB > Ec/Io

Ec/Io monitoring – event 1A report


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Number of cells versus median Ec/Io


HHO Ec/Io

thresholdTypical

target

Somewhat lower Ec/Io

for the 900 MHz band

Lower Ec/Io in SHO (cell

edge) than during RRC

setup (whole area)


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Number of event 1A reports versus Ec/Io

HHO Ec/Iothreshold

Typicaltarget

Cell edge

Many calls in bad

conditions

A considerable fraction of

calls even in HHO area # r e p o r t s


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Ec/Io monitoring – causes for low quality

Low

Ec/Io

Low

RSCP

Io mainly

due to UE

receiver

noise

High

Transmitted

Carrier

Power

Io mainly

due to own

cell

interference

High

Little i

Io mainly

due to other

cell

interference


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Overview

Ec/Io

Little I



SHO delay







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Estimate of little I requires knowledge both of

• Ec/Io (total interference)

•

TCP (own cell interference)

Little I monitoring not supported by NSN counters

Requires analysis of protocol trace

Little I monitoring - requirements


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0.25

0

0.50.75

Little I monitoring – role for capacity

Little I indicates grade of total cell power overlap

The higher the overlap, the lower the capacity

Example

16 W overload threshold

Little I = 1.0 → throughput = 700 kbps

Little I = 0.5 → throughput = 1100 kbps (about 60% more)

1.5


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Little I monitoring – RRC setup

Number of cells versus median little i


Typical target

Macro cell

Typical target

Micro cell

Somewhat higher little Ifor the 900 MHz band


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Number of connection requests versus little i

Typical target

Macro cell

Typical target

Micro cell

Little I monitoring – RRC setup

Whole cell area

Most calls little effected by

adjacent cell interference

Few calls strongly effected

by adjacent cell interference


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Median Ec/Io versus median little I

Each point = one cell

Little I monitoring – impact on Ec/Io

Clear relationship

Low Ec/Io mainly due to


Not due to high DL load


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Practical example – single cell of average performance

Ec/Io versus little I

Each point = one call

Little I monitoring – impact on Ec/Io

Clear relationshipLow Ec/Io mainly due to



Ai I f O i i i


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Overview

Ec/Io

Little I



SHO delay






Pil t ll ti it i i t


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Pilot pollution monitoring requires complete knowledge of the surroundings

of the UE

Event 1A report the only suitable message

RNC informs UE about ADJS cells to be measured by measurement control

message after

• RRC setup

• Active set update

Pilot pollution monitoring – requirements

UE BS RNC

Event 1A report =

ADJS cells measured by UE

Measurement control =

List of ADJS cells

Pil t ll ti it i bi d i hb li t


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Pilot pollution monitoring – combined neighbour list

Each cell has its own ADJS list

In SHO the ADJS lists of the individual active cells are combined together

according the following rules

1. Active set cells are included

2. Neighbour cells which are common to three active set cells are included

3. Neighbours which are common to the controlling cell and a second active set cell are

included. (cell, other than the controlling cell, which has the highest CPICH Ec/Io)

4. Neighbour cells which are common to two active set cells are included5. Neighbour cells which are defined for only one active set cell are included

6. Neighbours which are defined only for the second ranked cell are included

7. Neighbours which are defined only for the third ranked cell are included

If the combined list exceeds the maximum number of 32 cells during any

step then the handover control stops with the algorithm

Pil t ll ti it i bi d i hb li t


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Neighboured

Not neighboured

1

23 4

56

7

89

UE path

Neighboured

Not neighboured

1

23 4

56

7

89

UE path

Pilot pollution monitoring – combined neighbour list

Because of neighbour list combining it is possible

to measure handover activity between cells without

ADJS relationship

In the example ADJS relationship exists between

cells 2-6 and 6-7, but not between 2-7

In cell 2 cell 6 can be added to active set

Than cell 7 can be added to active cell as well, even

if cell 2 still is best active cell

Pilot poll tion monitoring detected set reporting


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RNC

ServingBTS

Pilot pollution monitoring – detected set reporting

ADJScells

Other nearbycells

According standard operation UE measures ADJS cells only

• Nearby cells forgotten in ADJS list will escape detection

• Will never become active and therefore can strongly interfere with active set

Detected set reporting

• Force UE to measure and report all visible cells

• Reported cell not defined as ADJS is detected cell ADJD

• SHO to ADJD cell allowed, if no ADJS cell available

Problems

• High signaling load for RNC due to longer

measurement reports

• Unstable SHO decisions due to degraded UE

measurement accuracy (more neighbors measured

during same time)

Pilot pollution monitoring NSN counters


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Pilot pollution monitoring – NSN counters

With the optional counters M1013, for each ADJS or ADJD cell one can evaluate

the following properties

• M1013C2 / M1013C3 = average Ec/Io difference active – non active cell (for all active cells)

• M1013C4 / M1013C5 = average Ec/Io (for all reported cells)

• M1013C6 / M1013C7 = average RSCP (for all reported cells)

From these counters follows the overall pilot pollution

With the optional counters M1028, for each ADJD cell one can evaluate the

following properties

• M1028C0 / M1028C1 = average Ec/Io (for all reported ADJD cells)

• M1028C2 / M1028C3 = average RSCP (for all reported ADJD cells)

cell activebest

i

icell neighbor

cell activebest

i

icell neighbor

Io Ec

Io Ec

RSCP

RSCP

pollution Pilot _ _

_ _

_ _

_ _

/

/

_

Pilot pollution monitoring overall results


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Pilot pollution monitoring – overall results

Number of cells versus median pilot pollution


Typical targetin SHO

Pilot pollution higher in

the 900 MHz band

In general rather high

values, as SHO (cell

edge) considered only

Pilot pollution monitoring overall results


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Number of event 1A reports versus pilot pollution

Pilot pollution monitoring – overall results

Typical targetin SHO

Cell edge

Many calls strongly effected

by adjacent cell interference

# r e p o r t s

Pilot pollution monitoring impact on Ec/Io


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Median Ec/Io versus median pilot pollution


Pilot pollution monitoring – impact on Ec/Io

Clear relationship

Low Ec/Io mainly due to

pilot pollution


For one cells low Ec/Io

due to low RSCP



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Ec/Io versus pilot pollution

Each point = one event 1A report


Clear relationship

Low Ec/Io mainly due to pilot pollution


Some reports taken under very low RSCP

Pilot pollution monitoring – cell matrix


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In case of high pilot pollution the interfering neighbors must be found

Treat each event 1A report by the following way

• Best active cell = server

• Each other cell = neighbor

Evaluate for each neighbor the following properties

• N = total number of reports collected for the server

• n = number of reports collected for specific neighbor

• Average ∆Ec/Io = Ec/Ioserver - Ec/Ioneighbor

Example values for pilot pollution

• ∆Ec/Io = 4dB (addition window) → pollution = 10-0.4 = 0.4

• ∆Ec/Io = 6dB (drop window) → pollution = 10-0.6 = 0.25

10/][/10 _ _ dB Io Ec

N

nneighbor pollution Pilot



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Pilot pollution monitoring cell matrix

Practical example – single cell of high overall pilot pollution

N reports

for server

n reports for

neighbor

Pilot pollution per

neighbor

e.g. 79 / 87 * 100.78 / 10 = 1.088

∆ Ec/Io perneighbor

Goal to detect neighbors responsible for high pilot pollutionConsider for each neighbor

How often reported ?

With which strength relative to the server ?



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In general very strong neighbors(problem over whole server area)

Very frequently reported

Then as strong as server or even

stronger

Occasionally too strongneighbors (local problem)

Rarely reported

But then stronger than

server

Cause for high pilot pollutionTwo very strong neighbors (probably their coverage area too large)

SC 123 in the average stronger than server (pilot pollution = 1.1)

SC 172 in the average almost as strong as server (pilot pollution = 0.7)



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In general strong

neighbors

Frequently reported

Then as strong as

server or even stronger

Cause for pilot pollution

Several strong neighbors (probably coverage area of server too large)SC 506 / SC 504 / SC 174 / SC 197

All with pilot pollution = 0.2…0.4

In general very

weak neighbor

Very seldom

reported

Far below server



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Cause of pilot pollution

One very strong neighbor (SC 92) with pilot pollution 0.7

Two strong neighbors (SC 89..91) with pollution = 0.2...0.4

On the other side many unnecessary neighbors with pilot pollution = 0

Pilot pollution monitoring – optimization flow


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High overall

pilot pollution

Few very

strong

neighbours

Intra-BTS

Many not very

strong

neighbours

p g p

Inter-BTSCheck whether coverage

area of server is too large

Check whether coveragearea of neighbor is too large

Check angle

between sectorsCheck horizontal

antenna beam



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Overview

Ec/Io

Little I



SHO delay





p

Propagation delay monitoring – limitations


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To recognize whether a cell is too large, at least the distances of the served

users must be known

UL frame protocol encapsulating RRC connection request the only message

indicating propagation delay

The propagation delay is given with a resolution of 3 chips = 234 m

p g y g

UE BS RNC

RRC connection request

UL frame protocol

RRC connection request encapsulated

Propagation delay

Propagation delay monitoring – NSN counter


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p g y g

Counters M1006C128…M1006C148

Number of connection requests falling into specific propagation delay interval

Updated in serving cell

The intervals are hardcoded, but depend on the setting of the parameter

PRACHDelayRange (see next slide)

The parameter offers the following options

• Set 1 up to 5 km





Propagation delay monitoring – NSN counter


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g y g

Propagation delay monitoring – too large cell


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Practical example – single cell with high pilot pollution

Cell matrix indicates

• No extremely strong neighbor

• But several significant neighbors

Number of connection requests versus propagation delay

Distant access outside

intended cell area

Server itself might be too large

Propagation delay monitoring – positioning


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Estimate of the position of an UE requires knowledge about the distance to

three BTS

Two possible options exist

• Combination of propagation delay information and propagation model

• Three visible BTS needed only

• But result depends on propagation model

• Combination of Rx-Tx time difference and round trip time

• Active set with three BTS needed

• But result model independent

Positioning not supported by NSN




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Positioning confirms too distant

access indicated by propagation

delay statistics

Probably water reflection

Server

Too distant

access

Number of connection requests per pixel

Practical example – single cell with high pilot pollution



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Practical example – cell appearing as strong interferer

Number of connection requests per pixel

Server

Too distantaccess

Positioning indicates too distant

access along broad street

Cell is interferer due to street

canyoning effect



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Overview

Ec/Io

Little I



SHO delay





SHO delay monitoring – idea


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Pilot pollution can be introduced not only by too huge overlap between cells,

but also by problems with SHO

• UE informs RNC too late about the need for SHO

• RNC setups new radio link too late

• RNC cannot perform SHO because no resource available in target cell

Addition window

4dB difference

CPICH 1CPICH 2

time

1st event 1A report e.g.

2dB difference

Ec/Io

New RL setup e.g.

1dB difference

SHO delay monitoring – idea


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Consider difference ∆Ec/Io between serving cell and best non active cell

under the following conditions

• First event 1A report sent after RRC setup (“measurement”)

• Last event 1A report sent before first RL setup due to SHO (“execution”)

Difference should be as close as possible to addition window

• Too small according “measurement” → UE acts too late

• Too small according “execution” → RNC acts too late

SHO delay monitoring not supported by NSN counters



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SHO delay monitoring – overall results


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Practical example – RNC cluster (execution)

Number of cells versus median 1A window

Red = RT Green = NRT

Addition

window

RT → almost same statistic as for measurement mode

no further delay due to RNC processing

NRT → statistic clearly shifted to even smaller 1A window

further delay due to RNC processing

SHO delay monitoring – impact on pilot pollution


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Pilot pollution versus 1A window


High pilot pollution

in case of too late

SHO process

Addition

window

RRC release

margin

Neighbor

equals server

1A reporting although addition

window not fulfilled yet

SHO delay monitoring – impact on Ec/Io


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Ec/Io versus 1A window


Very low quality in

case of too late SHO

process

1A reporting although addition

window not fulfilled yet

Some reports taken under very

low RSCP

Addition

windowRRC release

margin

Neighbor

equals server

SHO delay monitoring – event 1B


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Not only event 1A, but also event 1B related SHO procedure might be done

too late

Unwanted consumption of capacity, as bad active cell kept too much time in

active set• UE informs RNC too late about the need to drop bad active cell

• RNC deletes radio link too late

Drop window

6dB difference

CPICH 1

CPICH 2

time

1st event 1B report e.g.

8dB difference

Ec/Io RL deletion e.g.

9dB difference

SHO delay monitoring – event 1B


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Consider difference ∆Ec/Io between best and worst active cell under the

following conditions

• First event 1B report sent after RRC setup (“measurement”)

• Last event 1B report sent before first RL deletion due to drop (“execution”)

Difference should be as close as possible to drop window

• Too large according “measurement” → UE acts too late

• Too large according “execution” → RNC acts too late

SHO delay monitoring again not supported by NSN counters


P ti l l RNC l t ( t)

SHO delay monitoring – overall results event 1B


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Practical example – RNC cluster (measurement)

Number of cells versus median 1B window


Drop

window

RT → 1B window usually 8 to 9 dB

NRT → 1B window usually 7 to 9 dB

UE in general needs too much time to inform

RNC about SHO

In principle SHO process could be speed up by

somewhat lower drop window (5 to 5.5 dB)

But contradicts requirements for event 1A !!

Sometimes 1B reporting

although drop window

not fulfilled yet

P ti l l RNC l t ( ti )

SHO delay monitoring – overall results event 1B


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Practical example – RNC cluster (execution)

Number of cells versus median 1B window


Statistic slightly shifted to

bigger 1B window

Small further delay due to

RNC processing

Drop

window

Sometimes 1B execution

although drop window

not fulfilled yet




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RSCP indicated by the following RRC messages

RSCP monitoring – RRC messages


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RSCP indicated by the following RRC messages

Connection request serving cell only whole cell area covered

Cell update serving cell only cell edge (cell update) only

Event 1A report all measured cells cell edge (SHO) only

Event 1B report all active cells cell edge (SHO) only

Event 1C report all active cells and better neighbor cell edge (SHO) only

Event 1E report all active cells cell edge (HHO) only

Event 1F report all active cells cell edge (HHO) only

RSCP reporting by connection request optional feature only

UE BS RNC

Connection request

Cell updateEvent 1A…1F report


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RSCP monitoring in SHO not supported by NSN counters

RSCP monitoring – event 1A report


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RSCP monitoring in SHO not supported by NSN counters





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Number of cells versus median RSCP


HHO RSCP

threshold

Typical

target RT

Clearly better coverage in

900 MHz band

Too low coverage in 2 GHz

band especially for NRT

40W cells with 4W CPICH

required

Typical

target NRT




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Practical example single cell of average performance (2 GHz)

Number of event 1A reports versus RSCP

HHO RSCP

threshold

Typical

target RT

Typical

target NRT

#

r e p o r t s


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RSCP monitoring – impact on Ec/Io


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p

Median Ec/Io versus median RSCP – 900 MHz band


Lower Ec/Io at same coverage in

comparison to 2 GHz band

In 900 MHz band higher adjacent

cell interference


RSCP monitoring – impact on Ec/Io


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p g g p

Ec/Io versus RSCP


Ec/Io rather stable downto coverage of -100 dBm

Than rapid drop with

decreasing coverage




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g


Slow fading analysisCQI monitoring and improvement (HSDPA)


Both Ec/Io and RSCP undergo certain scatter due to shadowing

Slow fading analysis - motivation


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Must be taken into account when specifying thresholds for opposite procedures e.g.

• Event 1A (add cell) / 1B (drop cell)

• Event 1F (enter compressed mode) / 1E (leave compressed mode)

• Cell re-selection or ISHO to 2G / to 3G

If thresholds for such procedures are to close together, ping-pong mobility and thus

unwanted signaling occurs

NSN counter do not give scatter of Ec/Io and RSCP directlyMust be determined manually from Ec/Io and RSCP distributions of each cell


Slow fading analysis – scatter of Ec/Io


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Number of cells versus scatter of Ec/Io (RRC connection request)


Scatter of Ec/Io often larger

than 2 dB

Risk of ping-pong 1A/1B

Scatter of Ec/Io rarely larger

than 3 dB

Little risk of ping-pong 1F/1E

Default difference

Drop window –

addition window

Default difference

HHO Ec/Io threshold –

HHO Ec/Io cancel


Slow fading analysis – scatter of Ec/Io


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Number of cells versus scatter of Ec/Io (Event 1A report)


Under SHO conditions more scatter

of Ec/Io than during RRC setup

More shadowing at cell edge

Default difference

Drop window –

addition window

Default difference


HHO Ec/Io cancel


Slow fading analysis – scatter of RSCP


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Number of cells versus scatter of RSCP (Event 1A report)


Default difference


HHO Ec/Io cancel

Scatter of RSCP usually much

larger than 3 dB

High risk of ping-pong 1F/1E




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Slow fading analysisCQI monitoring and improvement (HSDPA)



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CQI monitoring - motivation

According NSN CQI reported every 4ms by UE


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Reported CQI compensated by Node B on the basis of

• Actual HS-PDSCH power

• Number of ACK and NACK

Node B decides about transport block size for next sub-frame

• Modulation (QPSK, 16QAM, 64QAM)

• Coding rate (1:6 – 1:1)

• Number of codes (1 – 15)

CQI (corrected)

CQI monitoring - motivation

The mapping between CQI and transport format is hardcoded by 3GPP in

dependence of the UE category


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16 3576 5 16-QAM 0

17 4200 5 16-QAM 0

18 4672 5 16-QAM 0

19 5296 5 16-QAM 0

20 5896 5 16-QAM 0

21 6568 5 16-QAM 0

22 7184 5 16-QAM 0

23 9736 7 16-QAM 0

24 11432 8 16-QAM 0

25 14424 10 16-QAM 0

26 15776 10 64-QAM 0

27 21768 12 64-QAM 0

28 26504 13 64-QAM 0

29 32264 14 64-QAM 0

30 32264 14 64-QAM -2

dependence of the UE category

CQI requirements

• ≥ 13 for data rate > 1 Mbit/s

• ≥ 16 for 16QAM

• ≥ 26 for 64QAM

1 136 1 QPSK 0

2 176 1 QPSK 0

3 232 1 QPSK 0

4 320 1 QPSK 0

5 376 1 QPSK 0

6 464 1 QPSK 0

7 648 2 QPSK 0

8 792 2 QPSK 0

9 928 2 QPSK 0

10 1264 3 QPSK 0

11 1488 3 QPSK 0

12 1744 3 QPSK 0

13 2288 4 QPSK 0

14 2592 4 QPSK 0

15 3328 5 QPSK 0

Mapping CQI – transport format

for UE category 13

CQI monitoring – reported CQI

WBTS counters M5000C8…M5000C38

N b f i di i ifi CQI


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Number of reports indicating specific CQI

M5000C8 number of reports indicating CQI = 0


…


Counters consider CQI as reported by UE, not CQI corrected by Node B

CQI monitoring – reported CQI

Practical example – CQI distribution for two cells


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QPSK 16QAM 64QAM


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CQI monitoring – transport format

No counters for compensated CQI available yet

Just WBTS counters for transport format selected by Node B


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Just WBTS counters for transport format selected by Node B

M5000C49…M5000C53 number of packets with 1…5 codes and QPSK

M5000C54…M5000C58 number of packets with 1…5 codes and 16QAM

M5000C86…M5000C95 number of packets with 6…15 codes and QPSK

M5000C96…M5000C105 number of packets with 6…15 codes and 16QAM

M5000C283 total number of packets with 64QAM (no subdivision in

dependence on number of codes)

CQI monitoring – transport format

Practical example – transport format distribution for two cells


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QPSK

16QAM

Cell with low CQI

Typically 5 codes allocated

Cell with high CQI

Typically 10 codes allocated

CQI monitoring – optimization flow


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Low CQI

Low Ec/Io

Low

RSCP ?

Low HSDPA

power

High adjacent

cell

interference ?

High R99

traffic ?

Wrong power

settings ?

(next chapter)


C it i d h t



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Adjacency Based Measurements Counters

NetAct tool (Optimiser 2.0)


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M1013 Autodef SHO

• M1013C0 Number of Intra Frequency SHO attempts – Counter is Updated when SRNC starts a Branch Addition or Branch Replacement procedure.

• M1013C1 Number of completed Intra Frequency SHO

– Counter is updated when SRNC successfully ends the Branch Addition or Branch Replacementprocedure.

M1014 Autodef IFHO

• M1014C0 Number of Inter Frequency HHO attempts

– Counter is updated when SRNC starts inter-frequency HHO

• M1014C1 Number of completed Inter Frequency HHO

– Counter is updated when SRNC successfully ends inter-frequency HHO

M1015 Autodef ISHO

• M1015C0 Number of Inter System HHO attempts

– Counter is updated when SRNC starts inter-system HHO

• M1015C1 Number of completed Inter System HHO – Counter is update when SRNC receives RANAP:IU RELEASE COMMAND from core network after

successful Inter System HHO

For each measurements (SHO, IFHO



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For each measurements (SHO, IFHO

and ISHO) Statistic show:

• # of HO attempts

• # of HO completed (successful)

to source and target cell objects

Measurement is carried out in SRNC

HO completion is considered

successful if the SRNC during the

handover decision does not detectany errors (errors in the source RNC

side or failure messages fromRRC/Iu/Iur/Iub interfaces)

Object identifiers for M1013 and M1014

Source-RNC/Source-CID

Target-RNC/Target-CID

MCC/MNC

Object identifiers for M1015 (ISHO)

Source-RNC/Source-CID

GSM-LAC/GSM-CID

MCC/MNC


Automated Adjacency Optimisation for 3G in Optimizer 2.0



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Accurate and efficient process for optimizingoperational WCDMA cell adjacencies.

Measurem ent based opt imizat ion

• Current adjacency status analysis

• Deletion of unused adjacenciesbased on KPIs

–

HO attempts, HO success• Adjacency candidate identification,

activation and measurement

– Interfering intra-frequency cells

– Cell pair Ec/No difference from WCDMA

– Neighbour cell signal strength from GSM

• Final adjacency list optimization

• Scrambling code re-allocation

Full visibility and control to the user

Automated Adjacency Optimisation for 3G in Optimizer 2.0



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Creating new adjacencies


A fast way to identify missing intra-frequency


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adjacencies

• Interference measurements colleted from

RNC

• New adjacencies can be created based onthat statistics

Rotation method used to achieve the optimallists

for other adjacency types

• Optimizer creates adjacency candidates

• Candidates are downloaded to network andmeasured

– Statistics collected directly from RNC

Cell pair Ec/No difference

Successful BSIC verifications & BSIC verificationtime

• Final adjacency list is generated

Creating ADJx based on PM data (AutoDef)



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Optimizer will show adjacency based SHO amounts forundefined neighbours. Purpose is to search all ADJS and ADJG new neighbours which are within certain max distance

• Example 1-5 km in urban area and 4-10 km outside urbanarea.

After that only those will be selected which have enoughSHO/ISHO attempts.The selected neighbours could beprovisioned straight away to the network

How to create Missing ADJx based on PM data-1

1. Select area from the map

and start the ADJ Optimization tool



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and start the ADJ Optimization tool

2. Select ADJG, ADJS and ADJW types


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6. Save plan from here with

any name



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4. Purpose is to search all ADJS and ADJG new

neighbours which are within certain max distance like

1-5 km in urban area and 4-10 km outside urban area.

After that only those will be selected which haveenough SHO/ISHO attempts.

5. Start from here

a y a e


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How to create Missing ADJx based on PM data-5 8. Select the whole week

or one day for PM data analysis



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10. Update the list of

Neighbours from here

9. Select the right profile tobrowser (ADJG, ADJS)

11. Sort according to

the PM attempts


12. See the ADJ on top of the map



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13. Provision the selected neighbors to the network

Note ! These neighbors are defined only for one way direction.

See next slides how to make those bi-directionally (Refreshactual operation with RAC)


14. Open the CM data exchange



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under the main window

15. Select refresh actual and wait

Until the data is updated

16. Open the adjacency optimization without selecting any

tabs from Deletion or Creation, just to find just created one way ADJx


17 Save the plan and list the planned elements



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17. Save the plan and list the planned elements

18. You can see now the ADJx neigbours which

can now provisioned to the network

Creating ADJx based on DSR measurements (ICSU)NetAct tool (Optimiser 2.0)


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Detected set measurements are not coming fromundefined neighbours (based on ICSU logs)

Aim is to find source of interference

• cell having many DSR results but no SHOattempts (with neighbour list combination list)

Solutions

• Add found cell to the neighbour

• Down tilt to decrease the interference

DSR measurements are suitable also for ADJGneighbours

DSR activation

Creating ADJx based on DSR measurements (ICSU)NetAct tool (Optimiser 2.0)


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When DSR is not activated, UE monitors only cells in its NCL (either read fromBCCH or sent from RNC in SHO case).

When DSR IS activated, UE scans ALL scrambling codes in same frequencyband and if cells are found that fulfil certain criteria, UE reports this/thesecell(s) as detected cells.

criteria for detection is that UE has to be able to detect if Ec/N0 is greater than

-18 (or -20???) dBfor a DSR to be triggered, detected cell/s must fulfill "normal" HO criteria, i.e.for example, are within the reported range relative to P-CPICH of strongest AScell.

Details of activation :MML command that is sent to RNC that sets some flagactive and RNC orders UE to measure and report. It can be done by HITmacro, but Optimizer is not (supposed to) using them but same commandsthat are in HIT macros are sent directly to RNC.

SHO Success Ratio RNC2 border with RNC3 Data before parameter changeSHO success at RNC border


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SHO success at RNC borderSHO Success Ratio RNC2 border with RNC3 Data after parameter change


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Documents

04 Air Interface Optimization