Atoll 3.1.2 Automatic Cell Planning Module.pdf

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Automatic Cell Planning Module

Atoll 3.1.2

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1. Introduction

2. Parameters Used by ACP

3. Network Reconfiguration Process

4. Site Selection Process

5. 1. Introduction

Automatic optimisation tool for GSM, UMTS, CDMA, LTE and WIMAX networks

To improve existing networks by tuning parameters that can be easily changed remotely

• Antenna electrical tilt

• Power (BCCH for GSM, Pilot for UMTS, Reference Signal for LTE, Preamble for WiMAX)

To optimise a network still in the planning phase by:

• Selecting antennas

• Changing the antenna azimuth

• Changing the mechanical downtilt of the antenna

• Changing the antenna height

• Selecting sites among a list of candidate sites

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1. Introduction

Principle

Optimisation of quality indicators

By automatic adjustments of network parameters

• Power (BCCH for GSM, Pilot for UMTS/CDMA, RS for LTE and Preamble for WiMAX)

• Antenna parameters:

• Type of antenna

• Azimuth

• Mechanical downtilt

• Electrical downtilt

• Height

GSM

• BCCH coverage

• Dominance of Best Server

UMTS/CDMA

• RSCP (Pilot) coverage

• CPICH Ec/Io

LTE

• Reference Signal coverage

• Reference Signal CINR

WIMAX

• Preamble coverage

• Preamble CINR

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1. Introduction

Principle

Optimisation process based on a cost function

The cost function depends on quality figures

• In GSM: the cost decreases when the BCCH coverage and the Best Server’s dominance increase

• In UMTS/CDMA: the cost decreases when the Pilot coverage and Pilot quality increase

• In LTE: the cost decreases when the RS coverage and RS CINR increase

• In WIMAX: the cost decreases when the Preamble coverage and Preamble CINR increase

Iterative algorithm is used

• Each iteration corresponds to one network parameter change

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1. Introduction

2. Parameters Used by ACP

3. Network Reconfiguration Process

4. Site Selection Process

5. 2. Parameters used by ACP

Requirements

Existing and valid path loss matrices

Recommendations

Creating a Computation Zone

• Used to define the default area where

the

ACP

calculates

statistics

on

performance indicators

Creating a Focus Zone

• Used to define the default area in which

are the cells to be optimised

Computation zone

= Zone used to compute statistics on

performance indicators (by default)

Focus zone

= Area where the optimisation will

be performed (by default)

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1. Introduction

2. Parameters Used by ACP

3. Network Reconfiguration Process

4. Site Selection Process

5. 3. Network Reconfiguration Process

Creating an Optimisation Setup

Defining Optimisation Parameters and Objectives

Running an Optimisation Process

Viewing Optimisation Results

Analysing Optimisation Results

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Creating an Optimisation Setup

To run the optimisation

immediately

To save the defined optimisation

parameters and run the optimisation later

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Defining Optimisation Parameters (1/9)

Selection of layers to be optimised

Layer(s) configuration

Several in case of Multi-RAT

networks (GSM+UMTS+LTE)

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Defining Optimisation Parameters (2/9)

Selection of zones to be optimised

Zones definition

Possibility to define

zones to be specifically

optimized, using:

• Clutter Classes,

• Hot Spots zones,

• .shp files

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Defining Optimisation Parameters (3/9)

Choice between quality or financial cost based optimisation

No cost control: the optimisation is only

based on quality

 Useful when planning a new network

Possibility to limit the financial cost of the

optimisation:

• Maximum financial cost allowed

• Compromise between the financial cost

and the quality

 Useful when improving an existing

network

Definition of the financial cost for:

• Each parameter change

• Each site visit

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Defining Optimisation Parameters (4/9)

Selection of transmitters/cells to be optimised

Definition of parameters that can be modified by ACP

To define Cells’ Optimisation parameters

(Subcells power in GSM, Pilot power in UMTS, RS power in

LTE and Preamble power in WiMAX)

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Defining Optimisation Parameters (5/9)

By default, GSM-UMTS-LTE transmitters sharing the same antenna parameters are linked

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Defining Optimisation Parameters (6/9)

Definition of Antenna Groups

To give some directives when reconfiguring the antenna type or the electrical tilt

Multi band “Physical Antenna”

Dual 900 1800 – 65deg17dBi

Multi band “Physical Antenna”

Dual 900 1800 – 36deg20dBi

Antenna Element

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Defining Optimisation Parameters (7/9)

Step 1 : Create “Antenna Element” (using radiating patterns)

• An “Antenna Element” is

defined by one gain, one

beamwidth and one frequency

band

• For a given frequency band, a

given beamwidth and a given

gain, the “Antenna element” is a

group of antenna patterns

obtained with different electrical

tilt values

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Defining Optimisation Parameters (8/9)

Step 2 : Create “Physical Antennas” (using Antenna Elements)

To define multiband antennas

Multi band

“Physical

Antenna”

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Defining Optimisation Parameters (9/9)

Step 3 : Create “Antenna Groups” (using Physical Antennas)

To define groups of Physical Antennas that will be then assigned to transmitters in the reconfiguration tab

Antenna groups to be

assigned to TXs in the

Reconfiguration tab

Created Physical Antennas

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Defining Objectives (1/11)

ACP allows you to define Quality and Coverage objectives for each technology

Objectives are assessed over a “Target Zone” (Computation Zone, by default)

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Defining Objectives (2/11)

Objective & Zone weighting

Objectives and Zones can be weighted according to their relative importance

Give priorities to specific Zones *

( Priorities only apply if the “Zone Weighting” option is checked)*

Give a priority to each objective

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Defining Objectives (3/11)

Traffic weighting (per objective)

ACP is able to focus more specifically on areas with a high traffic

Default option: NONE

the traffic is assumed to be uniform

 The quality indicator measured on

each pixel has the same weight

Selection of traffic maps (non-uniform traffic) to weight map pixels

 The quality indicators measured on each pixel can be weighted

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Defining Objectives (4/11)

Example: Defining UMTS objectives

Coverage objectives : UMTS RSCP Coverage

Define the

Minimum Pilot

Signal Level to

get on each

pixel of the

“Target Zone”

Coverage to be

respected while

meeting the

RSCP coverage

conditions

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Defining Objectives (5/11)

Example: Defining UMTS objectives

Quality objectives : UMTS EcIo

Define the

Minimum Pilot

Quality to get

on each pixel

of the “Target

Zone”

Coverage to be

respected while

meeting the Pilot

Quality

conditions

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Defining Objectives (6/11)

Example: Defining UMTS objectives

UMTS Objectives Parameters

For each indicator to optimize, ACP settings (display configuration, shadowing margin…) can be:

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Defining Objectives (7/11)

Summary of the indicators that can be optimized for each technology

GSM

• BCCH coverage

• Dominance of Best

Server

(= Number of potential

servers must be < 4)

UMTS/CDMA

• RSCP (Pilot) coverage

• CPICH Ec/Io

• Pilot Pollution

(= Number of cells in the

Active Set > 3)

LTE

• Reference Signal

coverage (or RSRP)

• Reference Signal CINR

(or RS C/N, RSRQ)

• Overlap

(= Number of potential

servers must be < 4)

WIMAX

• Preamble coverage

• Preamble CINR

• Overlap

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Load balancing (Optional)

ACP enables you to create and manage capacity planning objectives

• To prevent load imbalance between sectors and thus avoid the degradation of some KPIs

Example: Optimisation of a UMTS network by ACP without Load Balancing

The Load balancing feature relies on 2 performance indicators:

• The “Average Load” improvement (%), measures how the average load improves from the initial value

• Defining Objectives (8/11)

Cell A: Up-tilt (2°)

Cell B: Down-tilt (1°)

• Traffic served

• Cell load

- DL Total Power

- UL Noise Rise

• Interference

• Risk of congestion

Cell Load A = 75% ; Cell Load B = 60%

Solution: Load Balancing !

Cell A

Cell B

Cell Load A = 98% ; Cell Load B = 45%

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Defining Objectives (9/11)

Load balancing (Optional)

Can be activated in the “Objectives” tab under “Load Balancing”

Recommendation:

Keep the default

configuration

Allows you to select the

layers for which load

balancing is performed

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Defining Objectives (10/11)

Load balancing (Optional)

Traffic related to capacity planning can be defined in the “Capacity” tab

Traffic can be

considered as uniform

(evenly spread on each

service area) or,

generated from traffic

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Defining Objectives (11/11)

Load balancing (Optional)

ACP is designed to perform load balancing across multiple layers and technologies

For each service used,

traffic is balanced across

all the available layers

and technologies

For each service and

each technology, define

the minimum quality

required by a cell to

provide the service

To increase traffic density

specifically on some

zones. Traffic is scaled

according to the weights

defined in the “Zone

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Running an Optimisation Process (1/4)

Graphical display of the optimisation progress

“Graphs” tab: Variation of performance objectives in real time with iterations

The optimisation process can be

paused or stopped early

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Running an Optimisation Process (2/4)

Graphical display of the optimisation progress

“Changes” tab: Type and number of changes

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Running an Optimisation Process (3/4)

Graphical display of the optimisation progress

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Running an Optimisation Process (4/4)

Graphical display of the optimisation progress

“Objectives” tab: To see at a glance if the objective is achieved or not

Select the

objective to be

analysed

(coverage and

quality

indicators)

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Viewing Optimisation Results (1/5)

Optimisation results are stored in the optimisation

folder

Results available in 7 tabs

“Statistics” tab: synthesised view of optimisation

results for each objective

Statistics provided for the “Target zone”

• To get statistics on the other zones select “Show

Detailed Zone Results”

Statistics

for each

Global report available

in “Excel” format

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Viewing Optimisation Results (2/5)

“Graph” and “Quality” tabs

Histogram displaying statistics within the

computation zone or the focus zone

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Viewing Optimisation Results (3/5)

“Capacity” tab

Provides capacity load statistics for the initial and the optimised network

The graph shows the ratio of cells

with a capacity load that is smaller

than a given capacity load value (%).

Usually, the best result that you can

get is a final curve (blue curve) on

top of the initial curve (red curve).

Statistics based on the values

displayed in the table (on the right)

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Viewing Optimisation Results (4/5)

“Change Details” tab

Analysis of improvements according to the number of changes

Changes are ordered by “profitability”

• The most “profitable” changes will be applied first

Slider to select a subset of all

changes and view the corresponding

performance improvement on the

graph (global improvement and

improvement of each objective)

List of changes ranked from the change

with the most effect to the change with

the least effect

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Viewing Optimisation Results (5/5)

“Commit” tab

To commit changes that you allowed in the “Change Details” tab

Transmitters/cells with

parameter changes are

displayed in green

Initial and final cell

parameters displayed

Revert the network to its state

before the optimisation was run

Apply the set of selected

changes

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Analysing Optimisation Results (1/5)

Process

Quick validation of optimisation results using the ACP maps

• First analysis available without having to commit ACP results

• Based on the entire set of proposed changes

Deeper analysis with coverage predictions available in the predictions folder

• After committing ACP results

ACP Maps Available

Quality analysis maps

• Display of Coverage and Quality maps

Coverage analysis

• Status of the coverage according to the defined objectives used in the optimisation

Change analysis

• Analysis of changes: antenna, tilt, azimuth

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Analysing Optimisation Results (2/5)

Analysis with ACP Maps

ACP maps are automatically

calculated and inserted into

the folder containing the

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Analysing Optimisation Results (3/5)

Analysis with ACP Maps

Tiptext available for any ACP map

• The exact calculated value is displayed on each pixel

Display properties of ACP maps

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Analysing Optimisation Results (4/5)

Analysis with ACP Maps

Histogram available on ACP maps

Comparison tool

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Analysing Optimisation Results (5/5)

Analysis with coverage predictions from the predictions folder

Requirement: Commit results of the optimisation

Calculating prediction studies before and after the optimisation

Generating reports on the predictions studies before and after the optimisation in order to check if

network quality figures have been improved

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1. Introduction

2. Parameters Used by ACP

3. Network Reconfiguration Process

4. Site Selection Process

5. 4. Site Selection Process

Overview

Defining Candidate Sites

Viewing Optimisation Results

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Overview (1/2)

Examples of Site Selection process

Scenario 1: using ACP to select the best site among several candidates on a given geographical area

• 3 candidate sites available

• Candidate sites are assigned to a group where the minimum and the maximum site occurrence is set to “1”

 Among the 3 candidates, the ACP is forced to select only one site

Scenario 2: using ACP to deploy the LTE technology on a given area using existing UMTS sites

• About 40 UMTS sites (i.e. 40 candidate sites) available on the target area

• Candidate sites are assigned to a group where the minimum site occurrence is set to “10” and the maximum

to “20”

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Overview (2/2)

General process similar to the site reconfiguration process:

Creating an optimisation setup

Defining “Candidate” sites

Defining objectives and parameters to be optimised

• Note: The “Reconfiguration” mode is available (not mandatory) during the Site Selection process.

Running an optimisation process

Viewing optimisation results

Analysing optimisation results

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Defining Candidate Sites (1/3)

By using pre-defined sites

Prerequisite: Stations to be processed by ACP must be defined in the Atoll document with a given status

Two status for sites:

• “Existing”:

The site is an active site in the current

network. ACP can remove the whole site or

one or more sectors of the site to improve the

network quality

• “Candidate”:

The site is not on-air in the initial network (i.e.

all TXs are deactivated). ACP can add the site

or only one or more sectors of the site to

improve the network quality

Check “Current Site Selection” to allow changes

(site / sector removal) among “existing” sites

Check “Current Site Selection” to display

deactivated sites. Then, define groups of sites

with a min. and a max. number of sites to be

added during the optimisation (“Group”

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Defining Candidate Sites (2/3)

By using pre-defined sites

“Advanced” tab:

Allows you to apply the same

locking options to a set of sites,

and to manage groups

“Reconfiguration” column:

Select “Disable” to prevent ACP from making

any changes to the Transmitters or to the Cells,

as defined in the Transmitters and the

[Technology] Cells tabs

In case of network reconfiguration, you can

preserve the current angular separation

between antennas, and the relative height

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Defining Candidate Sites (3/3)

By importing a list of candidate sites

Option 1:

import a text file (*.txt)

containing at least candidates’

name and coordinates

Option 2:

import a list of

candidate sites from the Atoll

project

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Viewing Site Selection Results (1/3)

Statistics Report

Statistics and status of the

optimisation (

Achieved

or

Failed

) for each objective

Select “Show Change Statistics” to get

statistics on the sites/sectors added or

removed, and all the changes made

(53)

Viewing Site Selection Results (2/3)

Implementation Plan Analysis

Sites/TXs/Cells added or removed

List of changes (antennas, tilts, etc.)

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Viewing Site Selection Results (3/3)

Transmitters/Cells Modifications Analysis

List of candidate TXs/cells to be

added

List of TXs/cells to be removed

List of changes (antennas, tilts,

etc.), if “Reconfiguration” mode

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1. Introduction

2. Parameters Used by ACP

3. Network Reconfiguration Process

4. Site Selection Process

5. 6. Other Topics

Combined GSM/UMTS/LTE Optimisation (in case of several .atl documents)

Data Loading and Validity Control

Saving Settings to Configuration Files

Configuring Default Settings

(57)

Combined GSM/UMTS/LTE Optimisation (1/2)

Requirements (in case of several .atl documents)

Several Atoll projects (GSM, UMTS and/or LTE .atl files) that must be opened in the same Atoll session

General process similar to a classic optimisation

Creating the optimisation setup

Defining optimisation parameters

Running the optimisation process

Viewing optimisation results

Analysing optimisation results

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Combined GSM/UMTS/LTE Optimisation (2/2)

Procedure (in case of several .atl documents)

Step 1: Create the optimisation setup in one single technology document (a LTE document for ex.)

Step 2: Import other(s) network(s)’ configuration by importing associated project(s)

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Data Loading and Validity Control (1/2)

Data used when running an optimisation process

Radio data (antennas, sites, transmitters)

Traffic parameters (services, terminals, etc.)

Geographic maps (DTM, clutter class and clutter height maps)

Traffic maps

Path loss matrices

Loaded when creating an

optimisation setup

Direct access when running the

optimisation process

(60)

Data Loading and Validity Control (2/2)

Data validity control when running an optimisation process

Atoll checks the consistency between the optimisation setup, the actual state of the network and path loss

matrices

If inconsistencies => existing optimisation setups are locked and new optimisation process cannot be run

Incoherence with existing setup when:

Data changes are performed after creating the setup (e.g. New transmitter, transmitter deactivated,