optimizer guidelinesforautomatedfrequency

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AUTOMATIC FREQUENCY PLANING

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Nokia Standard Document Template

GSM RADIO NETWORK OPTIMIZATION GUIDELINES FOR NETACT OPTIMIZER 1.6ADJACENCY OPTIMISATIONFREQUENCY OPTIMISATION

Nokia Proprietary and Confidential

The information in this documentation is subject to change without notice and describes only the product defined in the introduction of this documentation. This documentation is intended for the use of Nokia's customers only for the purposes of the agreement under which the documentation is submitted, and no part of it may be reproduced or transmitted in any form or means without the prior written permission of Nokia. The documentation has been prepared to be used by professional and properly trained personnel, and the customer assumes full responsibility when using it. Nokia welcomes customer comments as part of the process of continuous development and improvement of the documentation.

The information or statements given in this documentation concerning the suitability, capacity, or performance of the mentioned hardware or software products cannot be considered binding but shall be defined in the agreement made between Nokia and the customer. However, Nokia has made all reasonable efforts to ensure that the instructions contained in the documentation are adequate and free of material errors and omissions. Nokia will, if necessary, explain issues, which may not be covered by the documentation.

Nokia's liability for any errors in the documentation is limited to the documentary correction of errors. NOKIA WILL NOT BE RESPONSIBLE IN ANY EVENT FOR ERRORS IN THIS DOCUMENTATION OR FOR ANY DAMAGES, INCIDENTAL OR CONSEQUENTIAL (INCLUDING MONETARY LOSSES), that might arise from the use of this documentation or the information in it.

This documentation and the product it describes are considered protected by copyright according to the applicable laws.

NOKIA logo is a registered trademark of Nokia Corporation.

Other product names mentioned in this documentation may be trademarks of their respective companies, and they are mentioned for identification purposes only.

Copyright Nokia Corporation 2006. All rights reserved.Bottom of Form

Document history:

DATEVERSIONAUTHOR(s)SUMMARY of CHANGES

14.05.20040.1dDimitrios DimarasDraft version for approval

03.08.20041.0Dimitrios DimarasApproved version

04.10.20041.1dDimitrios DimarasDraft updated version for approval

05.04.20052.0Squeo MariagraziaUpgrade to Optimizer 1.3-draft 1

26.04.20052.0Squeo MariagraziaUpgrade to Optimizer 1.3-approved

16.05.20063.0Kaj StenbergUpgrade to Optimizer 1.6-draft

06.06.20063.0Kaj StenbergUpgrade to Optimizer 1.6-approved

Tool history:

Optimizer 1.1NetAct OSS3.1 ED2

Optimizer 1.3NetAct OSS3.1 ED3

Optimizer 1.5NetAct OSS4 base release

Optimizer 1.6NetAct OSS4 CD Set 2 ; Increment 1 (March Release for OSRAS05)

Optimizer 1.6 CD-0945NetAct OSS4 CD Set 3 ; Increment 2 (June Release)

Optimizer 1.6 CD-1012NetAct OSS4.1 base release ; Increment 3 (September Release)

CONTENTS

4CONTENTS

71Purpose

72Target Group

83Abbreviations and acronyms

94Nokia netact optimizer overview

94.1NetAct Framework and Optimizer Interfaces

115RNW Optimization Process using Optimizer

126Preparations

126.1Pre-requisite checking

126.1.1Site and antenna data import

126.1.2Importing Site and Antenna Data with OSS4 (Optimizer 1.6)

146.1.2.1Required input data (CSV format)

156.1.2.2Creating Antenna object manually

206.2RNW Area definition for optimization

207Benchmarking

207.1KPIs for following up NW performance

217.2KPIs Measurement period

217.3KPIs in Optimizer 1.6

227.4Retrieving KPI data

227.4.1Retrieving KPI data in Optimizer 1.6

247.4.2Visualisation of KPI data in Optimizer 1.6

247.4.3Map settings in Optimizer 1.6

258Agreement of the RNW performance target values

269Deletion of unnecessary adjacencies

2610Measurements

2810.1Measurements needed for the optimization process.

2810.1.1Measurements needed for Adjacency optimization

2810.1.2Measurements needed for Frequency optimisation in Optimizer 1.6

2810.2Channel Finder and Defined Adjacent Cell measurements

2810.2.1BSC Counters: Defined Adjacent Cell (DAC) and Channel Finder (CF) Measurement

2910.2.2Measurements needed for Interference Matrix Generation in Optimizer 1.6

3010.2.3Measurements needed for KPI visualization

3010.2.4BSC divides I/C values into intervals

3110.3Predicted interference for initial allocation

3110.4Plan Management

3210.5BCCH Allocation lists

3310.5.1Dedicated BCCHs

3410.5.2BA lists for NW using more than 32 BCCHs

3510.6Analysis of existing BCCH conditions

3710.7Creation of new BA Lists

3710.8Exporting and activating BA Lists to BSCs

3710.8.1Workflow with double BAL activation

4610.8.2BA List Rotation Tool

4710.8.2.1Measurement period for CF and DAC

4810.8.2.2Method to limit the number of adjacencies for BAL rotation

4910.8.3Workflow with activation of BAL rotation

5410.9Interference Matrix in Optimizer 1.6

5510.9.1Blind spots

5510.9.2Identifying measured cells correctly

5610.10Retrieving measurements for the generation of Interference Matrix

5810.10.1Predicted measurements

5910.11Generation of Interference Matrix

6010.12Visualisation of Interference Matrix on a map

6110.13Interference Analyser

6311Adjacency optimization

6311.1Prerequisites for automated adjacency optimization

6811.2Running the measurement based Adjacency Optimisation

8011.3Post-optimisation actions

8211.4Managing Adjacencies manually

8211.4.1Managing Adjacencies manually in Navigator

8311.4.2Managing Adjacencies manually on a map

8511.4.3Instant provisioning

8612Frequency optimisation

8712.1Allocation scopes

8712.1.1Allocating frequencies for a part of the network

8712.1.2Allocating missing frequencies

8712.2Allocation algorithms

8812.2.1Fast algorithm

8812.2.2Accurate algorithm

8812.2.3Allocating planned objects only

8912.3Structure of the allocation algorithms

8912.3.1Algorithm Logic

8912.3.2Channel Assignment

8912.3.3Cost Function Calculation

9012.4User settings to guide the algorithms

9012.4.1Frequency group

9012.4.2Forbidden channels

9012.4.3Manual Separation

9012.4.4MA lists

9012.5Frequency optimisation algorithms

9112.6BSIC planning

9112.7Interpreting frequency optimisation results

9212.8Automated frequency planning and optimisation in Optimizer 1.6

9312.8.1Starting Frequency Optimisation

9512.8.2Managing iterations

9612.8.3User settings to guide the allocation algorithms

9612.8.3.1Assigning default frequency groups

9712.8.3.2Creating and defining frequency groups

9912.8.3.2.1Managing Intermodulation Interference in Optimizer 1.6 (optional)

10012.8.3.3Separation violation penalties

10112.8.3.4Assigning a frequency group to BTSs or to one BTS

10212.8.3.5Setting Manual Separations

10412.8.3.6Forbidden Channels

10512.8.3.7Hopping mode settings

10712.8.3.8Mobile Allocation List (MAL) usage

11012.8.3.9MAIO Offset and MAIO Step usage

11112.8.3.10Hopping Sequence Number (HSN) allocation

11212.8.3.11Setting the allocation scope

11212.8.4Performing frequency allocation and analysis

11712.8.5Verify the frequency allocation results

12212.8.6Visualisation of the allocation results on a map

12612.9Adding new frequencies to network elements

12913Related Documents

12914APPENDIX

12914.1Alternative method for the generation of Interference Matrix

13014.2Predicted Interference Probability

1 Purpose

This document covers the main steps needed for performing frequency and adjacency optimization using NetAct Optimizer 1.6 for 2G networks. This document does not provide a detailed description of NetAct Optimizer tool, but it provides guidelines for mobile measurement based frequency and adjacency optimization using NetAct Optimizer 1.6. This document also describes the process and workflow step by step in correct order.As Optimizer 1.6 (OSS4.1) is an improved version of Optimizer 1.5 (OSS4), the workflow and principles are mostly the same. Thus, this document can be used also with Optimizer 1.5 in some extent.2 Target Group

This document is intended only for Nokia network performance engineers. Those, who want to read this document, should already have a good knowledge of GSM RNW planning and optimization in order to be able to understand the information contained in this document.3 Abbreviations and acronyms

AAOAutomated Adjacency Optimisation

AFPAutomated Frequency Planning

ARPAverage Received Power

ARFCNAbsolute Radio Frequency Channel NumberBABCCH Allocation

BALBCCH Allocation List

BCCHBroadcast Control Channel

CFChannel Finder MeasurementC/ICarrier to InterferenceCIPCarrier to Interference Probability

CIRCarrier to Interference Ratio

CMConfiguration Management

DACDefined Adjacent Cell MeasurementFEPFrame Erasure ProbabilityGAMGraphical Adjacency Management

HSNHopping Sequence Number

I/CInterference to Carrier

ICRInterference to Carrier Ratio

IRPIntegration Reference PointKPIKey Performance IndicatorMAIOMobile Allocation Index Offset

MALMobile Allocation ListMMRMobile Measurement ReportRACRadio Access Configurator

RNWRadio NetWorkTSCTraining Sequence Code4 Nokia netact optimizer overview

NetAct Optimizer is a key element in the statistical, network wide optimisation process in the Nokia NetAct network management system. It provides accurate, cost efficient optimisation for operational GSM, (E)GPRS and WCDMA networks.

The strength of Optimizer is the combination of configuration management (CM) and performance management (PM) data on a geographical map of actual network data for optimisation basis. When actual measurement results from the network Key Performance Indicators (KPIs) and Mobile Measurement Reports (MMRs) are used for tuning the configuration parameters, the optimisation results are more accurate than in a prediction based approach. The benefit of using accurate results can be seen in improved network performance and capacity utilisation rate.

Optimisation algorithms contain the intelligence of relation between performance statistics and configuration parameters and their impact to the network behaviour. The effort spent in optimisation is minimised when letting the algorithms and rules analyse the network and propose better parameter configuration for both GSM and WCDMA cells. Also, the service performance improves once the optimal parameter configuration for each element is found.

As Optimizer is an integrated part of NetAct network management system, data transfers between NetAct modules, and the network are automated. This leads to further savings in effort and increases the speed of optimisation process.

When working with new network technologies and new services a thorough understanding of the network and service behaviour is essential for the optimisation work. Optimizer provides an informative view into the network via geographical map, which enables visualising and analysing the network configuration and performance in the same view.4.1 NetAct Framework and Optimizer InterfacesThe Nokia NetAct Framework is shown in Figure 1 below. The Configuring and Monitoring are essential parts of the NetAct Framework supporting the Optimising process, which Optimizer performs.

Respectively, the Optimizer interfaces are shown in Figure 2 below. SITE and ANTE data together with the CM Data forms the RAC database. Non-network data (e.g. antenna and site data) are thus also stored into the RAC database as soon as this information is imported by the user.Calculation of the selected KPIs (Key Performance Indicators) will take place in the Optimizer and this information is then stored in the Optimizer database. Actual CM data is automatically copied to Optimizer database.

Figure 1: Nokia NetAct Framework

Figure 2: Optimizer Interfaces and Data Flow.5 RNW Optimization Process using Optimizer

The process flow diagram below shows the necessary tasks for performing mobile measurement based frequency and adjacency optimization. The headlines below can be used as links pointing to the correct chapter somewhere later in this document.

Figure 3: Flowchart of the optimisation process.6 PreparationsFollowing actions have to be performed before the actual optimization process can be started.

Import site and antenna data of the RNW to the Radio Access Configurator database using Antenna Data Editor Define the RNW area Define the KPIs needed for performance benchmarking Activate the measurements needed for optimization and collect the measurement results6.1 Pre-requisite checking

The idea is that once Optimizer is properly installed and commissioned, site and antenna data is already there so, when starting optimisation there should not be need for importing site&antenna data. Sometimes the data is old and there might be need to update this. There might be other NW settings as well which needs to be updated.

One of the pre-requisites is that the data is up to date. Another one is to clarify NetAct status (RAC, PM DB).6.1.1 Site and antenna data import

Site and antenna data is required in order to visualize network topology in a geographical view and for calculating distance and antenna theta angle between cells. Distance and antenna angle information is used for example for cell identification when measurement information only contains BCCH/BSIC information of the cell.SITE and ANTENNA objects are introduced in Radio Access Configurator in order to store the non-network data (e.g. site co-ordinates, antenna directions, antenna model, etc.).

The SITE object is the way to store the geographical location of the site. For 3G BTSs, this is the only way to store the co-ordinate information.The ANTENNA object models the physical antenna used by one or several BTSs. It carries the same information as defined in the planning phase (antenna height, direction (azimuth), tilting, model, etc.). The antenna direction is very important for the visualisation of the network topology.6.1.2 Importing Site and Antenna Data with OSS4 (Optimizer 1.6)The Optimizer 1.5 introduced a new tool called Antenna Data Editor (ADE), which was improved in Optimizer 1.6. It is an administration tool, which is designed for fast import and synchronisation of site and antenna relations to the cells and (W)BTSs of the actual network. The tool is run whenever new sites and antennas, and relations to the cells in the network need to be updated. Site and cell coordinates are necessary in order to be able to visualise their location on the map in Optimizer. Data on the location of cells and the directions of antennas (azimuth) are required in creation of an interference matrix.There are two ways to do the import of site and antenna data into the NetAct database:

1. In case of network expansions with only few new cells/sites

Select those cells one at the time in ADE and Add the site and antenna information to each cell (see Figure 4 below). For the old cells, the site and antenna data has been already imported earlier.

2. In case of complete BSC areas (a mass import with all cells is needed)

Import of site and antenna data must be organised by means of an input file in CSV (Comma Separated Value) format. This type of mass import is typically needed only once. This procedure is described in the next chapter.

Antenna Data Editor supports data import from any external system producing a CSV data input file that complies with the import format definition.

Open the Antenna Data Editor tool

Select File, Import and find the CSV input file including your site and antenna data

You will see imported data in GSM and WCDMA views

You can select one BSC/RNC and the tool shows the site and antenna data for the BTSs.

Every BTS should have the site and antenna assigned when the data has been imported. If this is the case, then you can press the Save button.

Figure 4: Example of Antenna Data Editor (ADE).

6.1.2.1 Required input data (CSV format)It is most important to organize the data to import in CSV format. Each BTS and WCEL has its own row in a file. Each row has seventeen columns separated by commas, thus no commas allowed in actual data such as the address field. The following excel-sheet can be used in the data collection. It also includes a short description about the necessary data that must be inserted. All the mandatory data fields must be fulfilled as the optional fields can be left empty. It is very important to follow strictly the format shown in the example file below. Otherwise, the import with ADE might not be successful.

The best way to start the elaboration of the CSV input file is to copy three columns from the ADE-tool according to the instructions below.

1. Start Antenna Data Editor

2. Select a BSC under GSM in the navigator and wait until the cells are visible in the browser

3. Sort according to the CI column. There should be no Site IDs defined for any cell in case such a BSC has been selected, where no site and antenna information has been attached to the new cells yet.

4. Select the first cell CI value

5. Go to the last row

6. Press Shift and select the BTS/WCEL value of the last cell

7. Now there should be three columns selected (second, third and fourth column)

8. Press Ctrl-C

9. Open a text editor and paste the copied column values there with Ctrl-V

10. Move the file to your PC and open it with Excel

11. Fill in the rest of the values according to the example file attached above

12. Save in CSV (Comma Separated Value) format

13. Repeat steps 4-13 for every BSC

14. Import the CSV files to NetAct database by using Antenna Data Editor

Note, that the cellSectorID in the file must correspond to the BTS/WCEL column value in the Antenna Data Editor. Also there can be no commas in the site addresses or names. Also special characters like # or @ should be avoided in the file.

6.1.2.2 Creating Antenna object manuallyIn the last chapter, it was shown, how to assign site and antenna information to those cells, which are implemented in the network. This was done by means of a CSV input file. However, Optimizer offers its user the possibility to take cells, which have been planned but not yet installed in the network, into account, when planning neighbour relations and frequencies for such cells, for instance. In this case the planned cells do not exist in the actual data and therefore the import of site and antenna data with CSV file will not work. Thus, the antenna objects must be created manually for those new cells within the CM Editor. How to complete this procedure is described step by step below.Please refer also to chapter 10.4 Plan Management on how to import and export objects and changes between Radio Access Configurator (RAC) and Optimizer.The Antenna objects include ANTC (Antenna Collection), ANTE (Antenna), GCAL (GSM Cell-Antenna Link) and WCAL (WCDMA Cell-Antenna Link).

ANTE represents the base station antenna, GCAL and WCAL represent the feeder cables, and also the relationship to 2G and 3G cells.

Figure 5: Antenna Object

Here below are the main steps how to create antenna objects manually:

1. Create new plan (Plan -> New Plan -> give name to your new plan) with a new ANTE object under the ANTC using CM EDITOR.ANTC and ANTE are new managed objects which mean that these objects do not yet exist in the network.

You can create a new managed object by:

Selecting a parent object in plan and creating a child for it (choosing New Managed object from the MENU that appears clicking the right mouse botton on the ANTC object) or

Copying an actual or planned managed object with its parameters (choosing New MO from selected MO)

Figure 6: Creation of the ANTE object in new plan with CM Editor.

The fields to be inserted are as follows:

MOclass field: it is the class of the managed object that you want to create

MOID field: enter a local unique ID for the managed object. Locally unique means that the ID is unique under its parent object. If you leave this field blank, an ID is automatically reserved.

MO name field: enter a name for the object

Template name: It is mandatory to assign a template for the Managed Object. Otherwise, the MO will not be visible in Optimizer. By means of the templates, certain ANTE objects can be given common parameter values. If no other template exists, system template must be used.Clicking OK from the New managed object window, the new MO is added to the Navigation tree under its parent object as showed in the figure below.

2. Under the ANTE object, create GCAL and/or WCAL objects.For these objects you must define the parameter "Linked Cell DN" as shown in Figure 8. This parameter connects the antenna to the specifc BTS or WCEL. Example value: "PLMN-PLMN/BSC-4011/BCF-12/BTS-35".

The ante-30 ANTE-test is the new ANTE object. The steps to follow are the same as described above. The Planned Values of antenna data can be inserted manually or they are filled in by template selected in step 1 (Figure 6). For more information refer to CM Editor Help.

Figure 7: Adding of Planned Values of antenna data and GCAL or WCAL to ANTE object.The antenna data parameters to be inserted here are similar to those which shall be imported by means of the CSV input file as explained in the last chapter. Templates can be created in order to insert common data values. Cell specific values like antenna bearing and tilt angle must be inserted manually, of course3. Assign ANTE object to correct site objects

The gcal-30 GCAL-test is the new GCAL object. Insert the necessary planned values of antenna link data. This can be done either manually in this window or by a template selected in Figure 7. Assign the ANTE object to correct site object (one of the created new cells) by pressing the right mouse button and choosing Assign to Site This will open up the window shown in Figure 9. Select the correct site object from the list and press Assign. If the site is not yet in the list, it can be created by pressing New Site Respectively, if template is not yet assigned, assign template in the same way by selecting Assign Template from the pull-down menu. For more information refer to CM Editor Help.

Figure 8: Adding of Planned Values of cell antenna link data for GCAL or WCAL object.

Figure 9: Assignment of antenna object to the site object.You can check the assignment of antenna objects to the sites by selecting Sites in the Navigator pane and then a particular site in the data field as shown in the figure below. In the lower data field the objects belonging to that site are visible. At least one BCF and three antennas should exist. In this example also the created and assigned antenna object (ANTE-30/GCAL-30) can be seen.

Figure 10: Checking the assignment of antenna object to the site object.6.2 RNW Area definition for optimization

The area of the RNW, which has to be optimized, must be defined. Usually, because of poor performance, only some parts of the RNW have to be optimized. It is also necessary to consider the size of the surrounding area, which is not subject of optimization but affects the Adjacency and Frequency optimization of the NW to be optimized. Measurements must be performed also in the buffer area in order to avoid causing of additional interference there. Optimizer automatically defines the buffer area for frequency optimisation. No changes to the objects belonging to this area are allowed.

Figure 11: Optimization area and buffer area.7 Benchmarking

The optimization process starts with collecting measurement data from the RNW for benchmarking after optimization is performed. Benchmarking gives the possibility to compare how successful was the optimization.

7.1 KPIs for following up NW performance

It is recommended to collect data of certain Key Performance Indicators (KPI) for following up the NW performance after evaluating the adjacency and frequency optimization process in Optimizer.Below is shown a set of KPIs, which could be useful: Dropped call rate/Drops per Erlang RXQual SDCCH success TCH success Handover failure rate Handover distribution per class Traffic/blocking Before starting the actual optimization process it should be checked that measurements for all those KPIs are active and collected in NetAct PM database. Network doctor and Network Data Warehouse (NDW) can be used to collect the KPIs.

7.2 KPIs Measurement period

Data of the defined KPI set should be measured for pre benchmarking and for post benchmarking.

After each adjacency or frequency plan change the performance with the new configuration has to be measured. The KPI data collection period may be shorter in the middle of optimization iterations. The recommended follow up period is 3-4 days between the tuning processes and 5-6 days before and after the whole trial.

7.3 KPIs in Optimizer 1.6In Optimizer 1.6 Nokia GSM and WCDMA KPI definitions are used. The SQLs for KPIs are stored in a configuration file. Optimizer KPI set is fixed and must not be modified. Optimizer Product Line can modify and append the KPI set as an additional service for the customer.7.4 Retrieving KPI data

Optimizer automatically retrieves the data on the trend KPIs selected by the user from PM database every night and stores them into its own database. The KPIs can be summarised in different levels corresponding to the time, the KPI data is from. The user can choose the summarisation level. Possible options are: Daily Daily Busy Hour

Weekly Weekly Busy Hour

7.4.1 Retrieving KPI data in Optimizer 1.6The KPIs can be viewed by selecting the Network Statistics from the Tools menu.The introduction of this workspace enables to schedule the most important KPIs to be retrieved automatically every night, while the others can be obtained when needed. It is also possible to show the trend line of the KPIs.

The figure below shows the Optimizer 1.6 user interface with different tool options. The Figure 13 is the resulting window of selecting the Key Performance Indicators option from the Network Statistics.

Figure 12: Optimizer 1.6 main user interface.

Figure 13: Network Statistic Control workspace.To retrieve KPIs:

1. Open the Key Performance Indicators workspace as shown above from Tools -> Network Statistics -> Key Performance Indicators.2. Select a KPI or an element from the KPIs and Coverage table.

3. Check existing sets which are visible in the All Retrieved Sets table in the bottom of the window.4. If the KPI set does not already exist in the All Retrieved Sets table, then select the Summarisation Level and Time from the calendar and click Retrieve Set toolbar icon.

A set is retrieved for the selected KPI or element. You can check the status of the retrieval in Tools -> Task Management.

7.4.2 Visualisation of KPI data in Optimizer 1.6The visualisation of the KPI data is not exatly within the scope of this document, but here is a short summary about the different possibilities, that the user has.Cell icon size and color, dominance area and adjacency line color and thickness can be adjusted according to CM parameters and KPI values.

Cell icon size can vary between minimum and maximum defined by the user. Color visualisation needs also a threshold set and a color gradient. The first one defines the minimum and maximum ranges or values for the parameter or KPI and the latter one defines the colors and their order for the display of the values.More information on this topic can be found from the NetAct Help pages and Optimising NW with Optimizer.doc.7.4.3 Map settings in Optimizer 1.6The network configuration as well as the CM data or KPIs can be visualised on a map. The maps might be helpful, when the user wants get a better picture of the NW area. However, the usage of maps is not obligatory.Optimizer uses Geographical Information System (GIS) maps. Use Map Administrator tool in order to setup the GIS environment. The Map admin tool can be opened from the NetAct startpage or from the toolbox menu (under Nokia logo in upper right corner).In case GIS is used without maps, start the Map admin tool, setup the UTM zone and resolutions.

If the GIS is used with maps, then additional to the line above, import maps. Only Universal Transverse Mercator (UTM) projection is supported.Supported map formats are: Raster data (clutter, heights, e.g. pixels 25x25m); NetAct Planner raster data; NPS/X raster data

Vector data (points, lines or polygons); ESRI Shapefiles; MapInfo MIF files

Picture maps ( scanned maps, satellite photos); GIF, PNG, JPEG

More information about map settings can be found in GIS Principles or in Map Administrator Help.

8 Agreement of the RNW performance target values

At this point of the network optimization, it should be known for every participant, what is the target of the current optimization effort. In general, the network performance should be improved after optimization measures have been implemented. Also strict requirements for the network performance can be set. This can be expressed by performance target values, which the network performance must fulfill. The target values for the network performance should be negotiated together with the customer before the optimization can be started. Below are listed few such a target values as an example. Dropped call rate shall be less than 2% in more than 95% of all the cells RXQual in UL/DL shall be better than 6 in 95% of all the samples SDCCH success shall be better than 98% TCH success shall be better than 98% Handover failure rate shall be less than 5% for intraBSC handovers Handover distribution per cause shall indicate that better cell handovers are the dominant cause with more than 70% of all the causes Traffic/blocking shall state that the traffic values are normal (depending on the cell configuration) and that no blocking exists (e.g. TCH blocking shall not exceed 2%)The adjacency and frequency optimization are based on measurements and generation of the Interference Matrix (IM).Another important issue to be agreed with all the participants of the optimization project is the duration of the work. During the measurements are running, the network needs to be frozen i.e. no changes are allowed in the parameters nor in the NW configurations, that might affect the radio wave propagation. Network changes during the measurement period can jeopardize the reliability of the measurements thus making them unusable.The measurement period depends on the number of BCCH frequencies to be measured as explained later in chapter 10.8.2.1.9 Deletion of unnecessary adjacencies

It would be reasonable to start the optimisation measures by deletion of unnecessary adjacent cells, because this way some slots in the length of the BA lists can be possibly saved, thus making the measurement campaign easier and less time consuming. More information about the BA lists can be found from the chapter 10.5.The deletion of unnecessary adjacencies is based on the following three KPIs: HO Attempts to ADCE HO Success to ADCE HO Success RateAdjacency can be defined as unnecessary, when the number of HO attempts has been very small or close to 0 during the measurement period (at least few days).

These KPIs are typically activated by default, so no extra effort nor time is needed in the collection of this measurement data.The procedure, how to delete unnecessary adjacencies with Optimizer is described later in this document in chapter 11 in point 10. Remember to check first, that certain pre-requisites for the deletion are fulfilled as explained in chapter 11.1.10 Measurements

For the RNW optimization process certain measurements are necessary to be activated and performed before the actual optimization procedure can be started. Measurements are needed in every BCCH frequency. Measurements are based on the collection of MMRs (Mobile Measurement Reports).The flow diagram below shows the steps to be followed in order to provide the Optimizer with all the measurement data necessary for the generation of the Interference Matrix. Some of the tasks can require other NetAct application tools such as CM Editor, CM Operations Manager, etc. These are mentioned beside of each task block.Because measurements are needed in every BCCH frequency it is necessary to modify BA list settings for the BTSs before the measurements are started. For these changes there are two methods: Double BAL and BAL rotation. Which one is used, depends on the current BCCH allocation.The workflow of the activation of measurements with double BAL is slightly different from the activation of measurements with BAL rotation. These are explained later in this document. Both options are included in the process description below.

Figure 14: Flowchart of the measurement activation process.

The headlines above can be used as links pointing to the corresponding chapters elsewhere in this document.10.1 Measurements needed for the optimization process.

The NetAct optimizer utilizes the data of certain measurements collected in the NetAct for the optimization process. The best accuracy in the optimisation is achieved by mobile measurements.10.1.1 Measurements needed for Adjacency optimization

For Adjacency optimization following measurement data is utilized:

Handover Adjacent Cell Defined Adjacent Cell (DAC) measurements Channel Finder (CF) measurements.The DAC and CF measurements have to be explicitly activated.

10.1.2 Measurements needed for Frequency optimisation in Optimizer 1.6For Frequency Optimization following measurement data is needed:

Defined Adjacent Cell (DAC) measurements Channel Finder (CF) measurements Traffic10.2 Channel Finder and Defined Adjacent Cell measurements

DAC and CF measurements are optional in BSCs. Therefore they have to be activated in all the BSCs involved in the optimization process, and for all the BTSs of each BSC for a certain duration, which is needed to collect sufficient amount of data required for generating the interference matrix. Both measurements should be started simultaneously and within the same measurement period.

Mobiles report six strongest neighbors, which provide enough data to build up a reliable interference matrix. Data is collected from all active mobiles moving in a carrier area over a long period of time and the six strongest measured cells reported are then different.In the active mode mobiles measure the frequencies in the BA list and report six strongest cells where the BCCH-BSIC information can be decoded. These standard Mobile Measurement Reports are sent to BSCs every 480ms. The six cells are typically different in every MMR. Normally the BSC does not store these reports but uses them to make HO decisions. When the CF and DAC measurements are started the BSC stores the reports. If the BCCH-BSIC combination in the measurement sample matches that of a defined neighbor cell, the sample is stored in the DAC table in the BSC database. Otherwise the sample is stored in the CF table. After a defined measurement interval the reports are sent to PM database. This interval is typically 24 h (1440 min).Defined Adjacent Cell (DAC) measurement collects data from cells defined as adjacent cells as the channel Finder (CF) measurement collects data from non-adjacent cells.

Those cells that use the same BCCH channel as the serving cell cannot be measured and are defined as blind spots. Blind spots have a special treatment in the Interference Matrix (IM) creation.10.2.1 BSC Counters: Defined Adjacent Cell (DAC) and Channel Finder (CF) MeasurementThe Defined Adjacent Cell Measurement provides cell-level information on the signal levels of the defined adjacent cells. It gives the average signal levels as well as a means of calculating the standard deviation of the signal level of each defined neighbouring cell. Furthermore, the counters for the C/I ratio for each serving cell per defined adjacent cell pair are provided. These counters give the number of samples in each of the user-defined C/I ratio class.The interference matrix generated with this measurement can be used for automated planning. The object level of this measurement is the serving cell. For the signal level of the serving cell, the counters for calculating the average signal level as well as the standard deviation of the signal level are provided. For the defined adjacent cells, one block of results contains the following counters:

Average strength of the downlink signal

BSIC+BCCH of the measured cell Sum of the squares of the signal strengths (for standard deviation calculation) Three sample counters for C/I values

Denominator of the average strength of the downlink signal received from the serving cell.The channel finder measurement registers statistics on cells, which have not been defined as adjacent cells but which are among those six neighboring cells that the MS (mobile station) receives best. This measurement type collects one block of results for each cell. One block (per cell) of results contains six counters, which are mentioned above.Thus DAC and CF measurements are using exactly the same counters. Results are then written in two different tables according to the cell pair type (either signal measured from defined neighbor or from non-defined neighbor).For more information on the documentation of the counters with an example table and an explanation of the table fields, see BSC Counters: General Information on Measurements and Observations in S10 reference documentation.10.2.2 Measurements needed for Interference Matrix Generation in Optimizer 1.6For generating complete Interference Matrix (IM) Optimizer needs mobile measurements in every BCCH frequency in the network. During the measurements there should be no changes to the network. Otherwise, the reliability of the measurements is compromised.Optimizer uses the measured cell pair related interference information for frequency plan optimisation. When collecting CF and DAC measurements in every BCCH frequency, the information can be gathered for all operational BTSs. These measurements are collected by BSC, which sums up the MMRs of surrounding cell signal strength as experienced by the active mobiles. Hence, the interference matrix is in downlink direction only.The interference matrix generation functionality in Optimizer 1.6 can be enhanced with following issues:

Predicted interference can be generated to new cells or cells where measurements are missing otherwise [see chapter 10.10.1];

Interference measurement analysis and verification functionality has been improved (see chapter 10.13) FEP (Frame Erasure Probability) measurement from BSS S11 can be used as an alternative to CF and DAC. In that case MBAL tool must be utilised. More information about this method is given in appendix 14.1. Old results

Measurements from the previous optimisation rounds can be combined with the current measurements to reduce the number of blind spots (cell pairs without measurements) as explained later in chapter 10.11. This is the recommended way in the follow up optimisation.10.2.3 Measurements needed for KPI visualization

For GSM (2G) KPI visualisation it is necessary to activate in BSC the following measurements (these are typically active by default):

Handover adjacent Cell Measurement (ADCE KPI table, e.g. Ho_att_to ADCE)

Traffic Measurement

Resource availability Measurement (BTS KPI table, e.g. SDCCH congestion)

Handover Measurement

Resource access Measurement

BSC Clear code Measurement (SERLEV)

RXLevel statistics Measurement (BTS KPIs table or TRX KPI table. E.g. DL_cumulative_quality_class)

For WCDMA (3G) KPI visualisation other measurement must be activated in RNC but it is not the scope of this document.10.2.4 BSC divides I/C values into intervals

BSC measurements count values into I/C (=ICR) intervals instead of C/I (=CIR) intervals. This has an effect on how to define the parameter for the signal threshold defined in the BSCs, when the CF and DAC measurements are activated and on how formulas are written.The following table summarizes how the BSC allocates each sample to one of the three ICR intervals defined by boundaries DB1 and DB2. ICR is used to assign each measurement to the corresponding interval. It is obtained from the BSC. CIR is easier to understand; therefore, the meaning of counters N1, N2 and N3 in the table has been translated to CIR format.

Usually the boundary thresholds dB1 and dB2 for n1, n2 and n3 are specified for CIR. In that case the threshold values for ICR have to be inverted.

If for CIR, dB1 is lower value and dB2 higher value, then for ICR, -dB2 is the lower value and dB1 the higher value:

Table 1. Computing ICR and CIR from BSC measurements

n1n2n3

CIRCIR < dB1dB1 3.

Note: For each temporary BA list also a complete measuring phase is required. The measuring phases should cover at least the busy hours traffic during a week.

Defining cell is the one that has the maximum number of adjacent cells. The remaining free slots can be used for the rotation of the BCCHs (groups G1 ... Gn).10.6 Analysis of existing BCCH conditions

The activation of mobile measurements shall be started by selecting the BSCs involved in the optimisation process in the Navigator panel as shown in Figure 16 below.

Figure 16: Analysis of the BCCH conditions.The resulting window is shown below. Here the user shall select the options and click the Analyze button. With dual band network both frequency bands should be selected. It is recommendable to use the option BCCHs used in whole cluster in order to quarantee, that interference from the surrounding cells belonging to other BSCs are taken into account as well. Resulting figures will now appear in this window.Optimizer automatically adds BSCs to the scope, when the BCCHs used in whole cluster option has been chosen. BSCs added to the scope are then visible in the bottom of the window. The measurements must be started also in these BSCs in order to get measurements for the buffer area.

The analysed BCCH conditions will now determine the further steps in activation of new configuration plans. If there are less than 32 BCCH frequencies detected, creation of double BAL is possible. In case there are more than 32 BCCHs, then only creation of BAL rotation is possible. The workflows are slightly different and they are both described in their own chapters below.

Figure 17: Analysis of the BCCH conditions.

The Statistics worksheet above shows, that:- there is at least one cell that has only 2 adjacent cells in GSM 850/900 band- there is at least one cell that has no adjacent cell in GSM 1800/1900 band- no cell has less than 2 adjacent cells in any band- no cell has more than 11 adjacent cells in GSM 850/900 band- no cell has more than 17 adjacent cells in GSM 1800/1900 band- no cell has more than 24 adjacent cells in any band- there are total of 10 BCCH frequencies in GSM850/900 band- there are total of 38 BCCH frequencies in GSM1800/1900 band- there are total of 48 BCCH frequencies in the analysis scope

The Details worksheet above shows the number and ARFCNs of the BCCHs in the scope. In the example above 10 BCCHs in GSM850/900 and 16 BCCHs in GSM 1800/1900 bands were detected (ARFCNs not shown in this document). As the number of BCCHs in the scope (50) exceeds the limit of max BAL length of 32 BCCHs, the generation of double BAL is no longer possible and therefore the button Create BALs is not active in the example above.10.7 Creation of new BA Lists

There are two ways to create the BA Lists in Optimizer. In case the max BAL length of 32 BCCHs has not been exceeded, double BAL can be generated by pressing the button Create BALs. If there are more than 32 BCCHs in the scope only Create BAL rotation button will remain active. Both options are documented in the next chapters below.

10.8 Exporting and activating BA Lists to BSCs

There are also two ways how to make the required settings to the BSCs for the BA Lists and their activation in the BTSs: either using MML commands or using the NetAct Optimizer and CM Operations Manager tool. The activation of BA Lists in the network elements by using MML commands is not in the scope of this document, as it is much more convenient to do this based on the NetAct tools of the latest version OSS4. More information about the MML commands can be however found from the earlier version of this guideline (Optimizer 1.3 Guideline).10.8.1 Workflow with double BAL activation1. Create a configuration plan for double BAL list.

This option is possible, if there are less than 32 BCCHs frequencies defined for the adjacent cells. In this case, the Create BALs button is active. This step will automatically generate a new configuration plan, which contains the modifications related to the BA list. These modifications can be checked by the CM Editor from the BTSs. An example is shown below in Figure 19.

Figure 18. Creation of double BAL list.

Figure 19. Example of the modifications done automatically during the BAL creation.Three parameter modifications shall be done automatically for the BTSs during the BAL creation procedure: Idle State BCCH Allocation List (BAL) ID = created BAL number e.g. 1Defines the BCCH frequency list used by idle MSs.

Idle State BCCH Allocation List (BAL) ID In Use = true

Indicates whether an idle state list or carrier frequencies of adjacent cells are used for cell selection and reselection purposes in the idle state.

Measurement BCCH Allocation = Idle State BCCH ListBCCH Allocation usage for active MS. Determines whether an idle state list or carrier frequencies of adjacent cells are used by the active state BCCH measurement routine.

The number of Idle State BAL corresponds to the new created BAL object including the BCCH frequencies to be measured. Setting the Idle State BAL ID in Use to true means that this list is used for cell selection and reselection purposes in the idle state. More information about this was given in chapter 10.5.2. Export the new BAL plan into the RAC CM databaseFind the BAL plan created and export it to the CM database. This procedure takes few seconds per BSC. The progress indicator is visible in the bottom of the window. If there are many BSCs in the scope, each of them will have their own BAL plan.

Figure 20. Export of BAL plan.3. Provision the new BAL plan into the networkOpen the CM Operations Manager and search for the BAL Plan(s) exported in previous step. The Plan should be approved before the provisioning. Start the provisioning by selecting the option Provision from the pull down menu as shown in Figure 21. Only one Plan at a time can be provisioned.This procedure is applicable to any other plan as well (e.g. plans containing parameter changes or results from the adjacency or frequency optimisation algorithms).

Figure 21. Selecting the BAL plan for provisioning.

Following window will appear after selecting the Provision option above. Either select the BSCs or check the Entire Plan and fill in the other options before clicking Start. Selecting the Entire Plan will do the provisioning of the BAL plans for all the BSCs in the scope at the same time. The usage of this option is recommended.

Figure 22. Provisioning of BAL plan in the BSCs.The provisioning procedure can be monitored from the following window, which will appear after the Start button has been clicked in the figure above. Wait until the last message JOB ENDED telling you that the provisioning has been finished. This can typically take few minutes depending on the number of network elements involved.

Figure 23. Monitoring of the proceeding of the BAL plan provisioning procedure.

4. Verify that backup plan is createdOpen the CM Operations Manager and search for the BAL backup Plan. The backup plan should have been created automatically during the provisioning procedure. After the mobile measurements are finished and the interference matrix is generated, the original NW configuration has to be returned by activating the backup plan in the BSCs.The backup plan contains the parameters of the modified objects as they were before the modification and also a copy of the objects, which are deleted in the provisioned plan.

For instance if PlanA is provisioned, the CM Operations Manager generates automatically a backup plan with the name PlanA_backup.

5. Enable CF and DAC measurements for the target BSC by MML commandsBefore the CF and DAC measurements can be started in the BSC, these options must be activated in all the BSCs involved in the optimisation process. At the time being the activation of these measurement options can only be executed by MML commands. These commands are as follows:ZWOI:10;

Checks Channel Finder measurement option statusZWOS;

Checks DAC measurement option statusZWOC:10,65,00FF; Activates Channel Finder optionZWOA:2,626,A; Activates DAC optionThe MML session in the correct BSC can be started as follows:Open the Top Level User Interface from the NetAct start page under Desktop or from the Optimizer toolbox menu as shown below. This step requires administrator rights and an installation of the certificate. How to install certificates is explained in the Opt16_Installation&Commissioning.doc.

Select one of the network views to be opened up (e.g. Default.vie)

In order to find the correct BSC for CF and DAC activation, use the menu File -> Find Object -> BSC and select the right view

Click the right mouse button above the BSC icon and select the option for MML Session as shown in Figure 25 below.

Figure 24. Monitoring of the proceeding of the BAL plan provisioning procedure.

6. Create a new measurement plan for CF and DAC measurements

Open Administration of Measurements application. The application can be started from NetAct start page under Reporting or from the optimizer toolbox menu as shown in the last page. This step requires administrator rights and a certificate.New measurement plan for CF and DAC measurements can be done also with MML.

Figure 25. Creation of new measurement plan with Administration of Measurements tool.A following window will open up as a result of the selection above.

Figure 26. Configuring of a new measurement plan.

Now, it is time to configure the new measurement plan:

a name must be given for the new plan

measurement interval shall be chosen (1440 min = 24 hours)

additional parameters shall be filled inThese are I/C threshold values for the measurements (values -12 and 0 have been used for Optimizer measurements as a default or for good quality networks -15 and 3) (Please, refer to chapter 10.2.4 for more information).After the parameters above are filled in, click the Add button. The parameters are now saved into this new measurement plan. Then select the CF measurement and repeat the step.Click then OK button in order to save the new plan amongst the other plans.7. Start the CF and DAC measurements in the target BSCsChoose the new measurement plan and start it as shown below.

Figure 27. Starting a new measurement plan with Administration of Measurements tool.

A following window will open up as a result of the selection above.

Figure 28. Selecting the BSC(s) and setting the start and stop dates for measurements.Select the BSC, where the measurements should be started.

Defined Adjacent Cell measurement (DAC) and Channel Finder measurement (CF) should be started simultaneously and with the same measurement period.See also chapter 10.8.2.1 for the recommended duration of CF and DAC measurement periods.

Choose the start and stop dates and press the OK button. This will start the activation process of the measurements in the selected BSCs. This may take some time depending on the size of the network. The proceeding of the start process can be monitored from the following window. Wait until the start process is finished.

Figure 29. Status information during the measurement start process.

8. Return to the original BA list settings

After the measurements are completed, return to the original configuration. This can be done by provisioning the backup plan to the NW setting the parameters back as they were before activating the measurements. The provisioning procedure was already described earlier in this chapter in step 3 and the verification of the creation of the backup plan was explained in step 4.It is recommended to return back to the original configuration as soon as the measurements are completed, because the rotation of BALs in the idle state might decline the performance related to cell selection and reselection. For example, some cell far away and not defined as neighbour might be included amongst the six strongest measured cells. Triggering a cell reselection now to that cell might cause some problems. Respectively, the handover performance might be also slightly affected by the modifications of the BA lists.9. Retrieve measurement reports from PM database in order to create Interference Matrix

Information of Interference Matrices in general is given in chapter 10.9 and how to retrieve measurements in order to create them is described in chapter 10.10.

10.8.2 BA List Rotation ToolTemporary BA list is defined for the measurement period and the original BA list is returned once the measurements are completed. Temporary BA list should include all possible BCCHs, so that all the required data for correct adjacencies and frequency planning can be collected. If there are more than 32 BCCHs in use, the measurements have to be run in phases by circulating the BCCHs in the BA list.The BAL rotation tool is used to create BA lists for each BTS and to provision them in the BTSs. It verifies automatically that all the BCCHs of the currently defined neighbours are included into the BA lists in order to keep the NW performance and allow handovers between adjacent cells. Remaining part of the BAL is used to rotate frequencies so that all BCCH frequencies are measured. The structure of such BA lists was explained previously in chapter 10.5.2.The BALs created by the tool are all sent into the network automatically round after round by UNIX cron task. If the number of frequencies is much bigger than 32, the user can reduce the number of rounds needed for measurements by limiting the number of adjacent cell BCCH frequencies. This is explained in chapter 10.8.2.2 below.

10.8.2.1 Measurement period for CF and DACThe measurement collection period depends on the NW traffic situation. The target is to collect reliable amount of statistics from all the cell area locations. Typically it is recommended to run the measurements for few days, 3-7 days for each BA List set in case the amount of traffic is low in the network.During the measurement campaign the network must be freezed as explained previously in chapter 8. However, in most cases the customer cannot allow such a long measurement period as the network needs regular tuning. Therefore, the period must be shortened. Experiences from the trials indicates that even measuring just one day can give good results if there is enough traffic in the cells of the measurement area. In high traffic BSCs the lists can even be changed twice a day without sacrificing measurement reliability.In the picture below is shown the time schedule diagram for the CF and DAC measurements.

Diagram 3. Measurement collection period for CF and DAC.As mentioned previously, two measurements are required for generating the Interference Matrix: Defined Adjacent Cell and Channel Finder measurements. These measurements can be managed using the NetAct Administration of Measurements tool.

For more reliable Interference matrix generation in low traffic BSCs, measurements from a longer period are required (about one week), so the measurements have to be scheduled for some hours for several days. The measurements are sent from the BSC to PM DB after each measurement interval (defined in Admin of Meas plan). Running measurements for a long time might cause some extra load to the network and also to the MS handover behavior.Below is shown a step by step process, how to define a measurement plan and how to start and stop the measurements. Then the BSCs, which are involved in the measurements, have to be selected. The measurement Start and Stop time can be defined and by clicking OK the measurement can be activated. Notice that the status is changing from Inactive to Active10.8.2.2 Method to limit the number of adjacencies for BAL rotationThe more BCCH frequencies there are to be measured, the more measurement rounds are needed. Optimizer provides the possibility to reduce the number of adjacencies based on the number of HO attempts. Adjacencies falling below the set KPI threshold value are not taken into account in the generation of the BA lists.The user can estimate the minimum number of adjacent cell BCCH frequencies by using the method called Calculation of minimum number of adjacent cell BCCH based on a KPI value.In order to start this procedure, press the following button in the BAL/MBAL Management window (see Figure 32) and the following Select KPI window will appear.

Figure 30 Calculation of minimum number of adjacent cell BCCH based on a KPI value.Fill in the options.Adjacencies can be limited based on the number of HO attempts. For example, only adjacencies that have more than 20 HO attempts during the last day will have their target cell BCCH frequency in the BA list. In practise, BAL tool uses the total number of HO attempts in the PM database to drop the adjacent cell frequencies.10.8.3 Workflow with activation of BAL rotation

1. Obtain BCCH allocation lists from the NW area to be optimisedOpen the BAL/MBAL Management window and run the analysis of the BCCH conditions as shown and explained in chapter 10.6. If there are more than 32 BCCH frequencies detected, only the creation of BAL tool configuration is possible.

The handling of the measurements in case of double BAL is slightly simplier, as no BAL rotation is needed.2. Delete all the old BAL objects under the BSCs in scope

Before the new temporary BA lists can be activated for CF and DAC measurements, the old BAL objects must be deleted. This is needed because the BAL tool creates new BAL objects starting from BAL-1 for the BTS-1. Existing BAL objects might cause a conflict for the tool.Use CM Editor to create a plan, which will delete all BAL objects under the BSCs in scope. The BAL objects must be chosen one by one as shown in figure below and from the pulldown menu, which appears by clicking the right mouse button, Change to Delete shall be chosen. After this step has been repeated for each and every BAL object, exit the CM Editor. The changes are stored in this new plan.

Figure 31. Deletion of BAL objects.3. Export the configuration plan containing deletion of old BAL objects to CM databaseThe export procedure was already described earlier in this document in chapter 10.8.1 in paragraph 2.

4. Provision the plan into the networkThe provisioning procedure with CM Operations Manager was already described earlier in this document in chapter 10.8.1 in paragraph 3.5. Verify that backup plan is createdAlso this procedure is similar to that one described earlier in chapter 10.8.1 in paragraph 4.6. Create a configuration plan for BAL rotation (optional)In case the analysis of the BCCH conditions has detected, that there are more than 32 BCCHs, this is the only option, which is active as shown in the next figure. The option Create BAL rotation will automatically generate necessary input for the BAL Rotation tool, which then takes care of the generation of the BA lists for rotation. The BA lists for rotation include all currently defined neighbours. However, this step is only optional as all the related parameters and configurations of the BA lists can be modified within the BAL Rotation tool. This step is even though quite useful and therefore recommended.

Figure 32. Creation of BAL rotation configuration.Use the BAL Rotation tool for the creation of the BA lists.The tool can be started from NetAct start page or from the optimizer toolbox menu. This step requires administrator rights and installation of the certificate. How to install certificates is explained in the Opt16_Installation&Commissioning.doc.Fill in the necessary options in the Parameters tab shown in Figure 33. The ADCEs to be kept and the BSCs in scope are taken from the analysis of the BCCH conditions, which was run in step 1 above. In Optimizer 1.5 these fields were fulfilled automatically as in Optimizer 1.6 the user has to fulfill them manually. Click the button Save changes when you are ready with setting the necessary parameters.Next, select the Creation tab and click the button Create BALs for rotation. The proceeding of the creation of BA lists can be monitored in the window shown in Figure 34. In the end of this creation process a summary of the results is presented. This will for instance include the information of the number of rounds needed in order to measure all BCCH frequencies.Note also, if there are any warnings given in the end of this process. For example the following warning can be given:

WARNING! Some other user(s) have created BA lists for the same BSC(s)

as you. DO NOT START rotation on unless you are SURE that there is NO

ongoing rotation in the scope BSC(s)!!Thus, the deletion of old BAL objects described in step 2 in this chapter is necessary.

Figure 33. BAL Rotation tool.

Figure 34. Results of the creation of BA lists.

7. Schedule the provisioning of the configuration plans into the networkThe provisioning of the needed different configuration plans containing the BA lists for rotation during the measurement period can be easily scheduled by using the Cron tab in the BAL Rotation tool. Several configuration plans can be scheduled e.g. to circulate automatically the BA lists for Interference Matrix generation measurements.

Select the Cron tab in order to create the scheduling as shown in Figure 35 below.

Set the time close to midnight (e.g. 23:30) or about 30 minutes before the measurement interval (defined in Admin of Meas) starts and select all days. The provisioning of the BA list in the BSC might take some time. This procedure will ensure that the BA lists are rotated once a day at 23:30 on every day of the week.

In the example above, 21 rounds (i.e. 21 different BA lists) are needed in order to measure all the BCCH frequencies. In case, that the measurement period has been chosen as 3 days with each of the BA lists, it takes 63 days to complete the CF and DAC measurements. The BA lists are rotated daily at 23.30 within this example. Certainly, this period is too long and both adjacencies must be reduced and measurement period shortened e.g. from 3 days to 1.Add task to the Cron tasks list, select the task from the list and start the BAL rotation by clicking finally the Commit changes to cron tab. Now the user can exit the BAL Rotation tool. How to stop the BAL rotation task is shown later in this chapter in step 9.

Figure 35. Creation of the scheduling for BAL rotation.There are three new tabs in the BAL Rotation tool of Optimizer 1.6 in a comparison to the older version.It can be checked through the Status tab, if there are any ongoing rotation tasks and which user has started them. The tabs for CH Set Cell Set are used for some special cases. They are typically not needed for the standard measurement based adjacency and frequency optimisation and therefore not described in detail within this document.8. Enable and start the CF and DAC measurements for the target BSCsThis workflow has been described previously in chapter 10.8.1 in steps 5 to 7. Here the steps are briefly listed:- 5. Enable CF and DAC measurements for the target BSC by MML commands- 6. Create a new measurement plan for CF and DAC measurements- 7. Start the CF and DAC measurements in the target BSCs9. Return to original BA list settings

After the measurements have been completed, return to the original configuration.

Open the BAL Rotation tool again and select the Cron tab (see Figure 35 above).

Select one of the cron tasks from the list and click the Remove task button or remove all tasks at the same time by pressing Remove all tasks. This will stop the cron task for the rotation of the BA lists.

Select next the Rotation tab and click Remove rotation. This will remove the temporary BA lists for rotation from the CM database.

Finally, open the CM Operations Manager and provision the original backup configuration plan from step 5 to the BSCs in order to return the original BAL objects as they were before activating the measurements.It is recommended to return back to the original configuration as soon as the measurements are completed, because the rotation of BALs in the idle state might decline the performance related to cell selection and reselection. For example, some cell far away and not defined as neighbour might be included amongst the six strongest measured cells. Triggering a cell reselection now to that cell might cause some problems. Respectively, the handover performance might be also slightly affected by the modifications of the BA lists.10. Retrieve measurement reports from PM database in order to create Interference Matrix

Information of Interference Matrices in general is given in chapter 10.9 and how to retrieve measurements in order to create them is described in chapter 10.10.10.9 Interference Matrix in Optimizer 1.6As already mentioned the Interference Matrix is used as an input for adjacency optimization or for automatic frequency allocation. It contains the interference relations between all cell pairs. Interference Matrices are stored in the Optimizer database. The process flow for generating an Interference Matrix was shown previously in Figure 14.Interference can be computed or expressed with different mathematical methods such as:

CIP (Carrier to Interferer Probability) ARP (Average Received Power) FEP (Frame Erasure Probability)In case of missing or low quality measurement data, it is possible to use predicted interference values to complement measurements. It is also possible to combine data from several sets by giving a priority for the sets. However, if the measurement campaign has been planned and accomplished carefully, there will be most probably no need to complement the measured values with predicted ones, when creating the interference matrix for adjacency or frequency optimisation.The optimiser 1.6 generates an Interference Matrix in XML format. Below is shown a couple of lines as an example of an IM XML file.

The Interference Matrix contains the following fields:

Serving BSC ID Serving BTS ID Serving cell LAC Serving Cell ID Interfering BSC ID Interfering BTS ID Interfering cell LAC Interfering Cell ID The layer (BCCH) coDLCIP (Carrier to Interferer Propability for Co channel interference in Downlink) adjDLCIP (Carrier to Interferer Propability for Adjacent channel interference in Downlink) coARP (Co channel Average Received Power value) adjARP (Adjacent channel Average Received Power value)For further information please refer to the optimizer documentation Interference Matrix Open Interface.10.9.1 Blind spots

Cells in the NW having the same BCCH with the serving cell are not measured. The signal of the serving cell is much stronger. It covers all other signals on the same frequency. These co-channel cases are seen as blind spots in the interference matrix. Some of these pairs may in reality interfere with each other.For blind spot cell pairs optimizer assigns in the Interference Matrix the following default ARP and CIP values. These values can be defined by the user in the dialog shown in Figure 38.

coDLCIPblind spot = 3 %adjDLCIPblind spot = 0.1 %

coARPblind spot = 10

adjARPblind spot = 2The number of blind spots can be reduced by combining new measurements with earlier ones that have been performed with a different frequency plan.10.9.2 Identifying measured cells correctly

In mobile measurement reports each measured cell is identified with BCCH frequency and BSIC only. In a general case there are several cells in the DB using the same BCCH-BSIC combination. Therefore it cannot be always known for certain which cell has actually been measured by the mobile. Any cell with matching BCCH-BSIC might be the cell that the mobile has been measuring. Optimizer uses both distance and antenna bearing when trying to recognise the interfering cells.

In the picture below, an example is shown, how interfering cells are identified based on distance and bearing. (Cell C is the interfering cell although it is located further away from the serving cell than cell B).

Figure 36. Identification of interfering cells based on distance and antenna bearing.10.10 Retrieving measurements for the generation of Interference MatrixMeasurement retrieval is only used for interference data. Measurement raw data is stored in NetAct PM database typically for 1-3 weeks.In order to create the Interference matrix, the user has to do the following steps.

Select Interference Matrices from the Tools -> Network Statistics menuThis will open up the following workspace shown in the figure below.

Figure 37. Identification of interfering cells based on distance and antenna bearing. Select one or more BSCs for the retrieval of measurement data

Select interference type (CIP and ARP are retrieved together) and press the Retrieve button

This will open up the following window as shown in the figure below.

Figure 38. Interference measurement retrieval. Fill in the parameters Insert measurement start and end date. How many blind spots should be generated at the maximum (i.e. the maximum number of BTSs in the database with the same BCCH). If the measured interference value is below the selected Retrieval Threshold, then value 0 is entered into the IM. Default values are given to the generated blind spot interferers (short introduction to blind spots was given in chapter 10.9.1 above). If the source of the interference is not found within the Maximum BSIC Reuse Distance, then interference is considered to be external. Set the reliability scaling, which equals to the number of potentially interfering cells.

For each retrieved measurement there is a calculated reliability that depends on the number of interferers and the amount of traffic during the measurement period. If traffic is not retrieved then reliability depends only on the number of interferers.The formula for the calculation of the reliability is as follows:

reliability = 0.3 x g + 0.7 x f , where

g = #of_interferers / reliability_scaling(if g > 1, then g = 1)f = samples / (7000 x traffic)(if f > 1, then f = 1)

#of_interferers corresponds to the average number of cells that can be seen in the middle of the network. Samples are collected once per SACCH frame (i.e. every 480 ms, leading thus to about 7000 samples per hour).

The usage of antenna bearing and retrieve traffic options are recommended, only if it is known that the antenna bearing exists.

Finally, click OK and wait few moments as the retrieval of data takes place.

The retrieved data sets for the chosen BSCs can be seen in the Interference Matrices workspace as shown in the following figure. Both CIP and ARP are retrieved at the same time.

Figure 39. Interference measurement retrieval.Very often it is difficult to know whether the CF, DAC and FEP measurements are collected long enough, whether the values are reliable enough or whether all essential cells are really measured. As the accurate interference matrix is crucial for accurate frequency allocation Optimizer 1.6 provides means to verify the measurement data.

When the measurements are obtained and before the interference matrix is calculated Optimizer presents few statistics of the each cell pair in measurement data:

Amount of measurement samples per cell pair Measurement coverage: are all the BTSs measured under the BSC where measurements were activated or have some BTSs been down etc.

Reliability: calculated using the amount of samples in different levels, BSC, BTS and cell pair

Cell traffic figures: to identify that the measured cells really carry traffic, meaning there are mobiles that are expected to report the interference

10.10.1 Predicted interference dataThere can be two types of measurement data sets: either measured or predicted ones. If the measurements have been activated carefully for the automated adjacency and frequency optimisation, there is no need to use predicted values. However, predictions can be used to cover blind spots or to replace missing measurements. In case predictions are needed, the workflow is described here in the attached document below. However, it is not recommended to use the predictions, because these may give quite inaccurate and unreliable results. In case, the measurements have been activated according to this guideline document, there should not be any need to use predicted values.

10.11 Generation of Interference Matrix

Without priority there is no interference data available in Optimizer. Priority settings are user specific. If a set has no priority assigned to it, it is not taken into the combined matrix. Therefore, priority is needed for every set to be included in the IM. Priority 1 should be assigned to the most important (newest) set of measurements. Insert priority values for both the measured and/or predicted sets for all interference types (CIP and ARP) that were retrieved (see Figure 40 below for an example)

Figure 40. Selecting predicted and measured data sets for the generation of combined IM.It is advisable to combine also older measurement sets with a lower priority to the interference matrix, because this way many of the blind spots can be possibly avoided.

Figure 41. View compound.A combined set contains blind spots. Blind spots are treated in the following way:

- a blind spot value is always replaced with a measured value- if there are two sets with the same priority, the measured set is taken into use- if there is a blind spot and a predicted value for the same cell pair, the blind spot (default) value is used if its priority is higher

- if the predicted value is higher than the default value for the blind spot, the predicted value is used10.12 Visualisation of Interference Matrix on a mapInterference Matrix couplings between cells can be seen on the map. For each pair of cells the value above threshold is shown on the map as a line between the cells. Interference values represent Carrier over Interference Propability or Average Received Power values from the measurements. Select Other and Interference Matrix Value or Interference (%) as shown below.

Figure 42. Visualize interference.

Adjust the parameters and calculate the lines

By setting the color gradient properly, the user has the possibility to see strongest measured cells. Usually it is not possible to check every cell.

Figure 43. Adjustment of parameters for visualisation of interference lines.

Note that in a dual band network the mobiles measure both frequency bands. That is why the interference lines also show measured cells on the other band. These inter-frequency results can be used in the adjacency optimisation to create new adjacencies to the other band.

10.13 Interference AnalyserOptimizer 1.6 introduces a new tool called Interference Analyser for further study of the interference between cell pairs. The Interference root cause Analysis tool uses always the measurement set with the highest priority. Predictions are not considered in Interference Analysis. The tool is used to identify those cells that cause high interference over a long distance thus making the frequency allocation difficult. Corrective measures in that case might be for instance antenna downtilting. Results can be filtered by setting certain thresholds for minimum distance and for minimum amount of interference. Only those cell pairs exceeding these minimum values are listed. They can be then either located on the map or analysed in the chart. The functionality of this tool is based on the generated Interference Matrix.The purpose of the tool is briefly as follows: The tool introduces a new method to find POTENTIAL interfering cells in the network by using visualization and analysis functions of Optimizer. Decision and physical actions are left to the end-user. The actions can be for instance antenna azimuth or tilt changes. If and when there are cells in the network that are interfering many (distant) cells in the network, it is not efficient to correct these mistakes by frequency planning. More efficient way is to e.g. down tilt antennas, and thus reduce the coverage/interference area of a cell.The following figures will highlight the usage of this tool.

Figure 44. Interference Analyser tool. Select the BTSs for Interference analysis in the navigator panel Click the right mouse button and select Tools -> Interference Analyser

This step will open up the window shown in Figure 44.

Set the thresholds for minimum distance and for minimum amount of interference

The results shown in the browser list must exceed these thresholds.

Select interference direction and type and press the Refresh button

Now the cell pairs filling the set criterias are shown in the browser.The user can either visualise the selected cell pairs (one or many) on a map by clicking Locate on map button or show them on chart. The chart view will quite easily show for instance, if there are cells causing high interference probability to others from far distance.

Figure 45. Interfering cell pairs on a map.Figure 46. Interfering cell pairs in chart view.11 Adjacency optimizationAdjacency optimization utilizes mobile measurements collected and reported by BSCs. Based on the ADCE KPIs the unused adjacent cells can be identified and removed from the adjacency list. Respectively, based on the ARP values of the Interference Matrix, new ADCE objects can be created.The generated new adjacency plan can be visualized and modified if necessary before provisioning to the NW.

Adjacency optimization does not delete mandatory adjacencies. Mandatory adjacencies are defined on the map or in the Browser. It is also possible to create and delete outgoing adjacencies to foreign targets within the optimization algorithm.

The process for automatic adjacency optimization of a GSM RNW using the optimizer is described in this chapter. The adjacency optimization can be started after the measurement reports are obtained.

Important notes: Automated Adjacency Optimisation should always be completed in prior to Frequency Allocation Optimisation, as the deletion/creation of adjacencies will have an impact on the allocation of frequencies.

Also during the ongoing optimisation process, no changes in the network configuration nor parameterisation are allowed.

11.1 Prerequisites for automated adjacency optimization

Before the automated adjacency optimisation algorithm can be started, there are few items that must be completed first. These are listed here below.

1. Make sure that antennas have been defined for every cell

How to import antenna data into the CM database was explained in chapter 6.1.1. Also planned sites, which do not yet exist in the BSCs can be subjected to the adjacency creation as long as they have antennas defined.

2. Check that Interference Matrix (ARP) with priorities defined is available

How to start measurements necessary for the creation of IM, was explained in the last chapter.

3. Check that the ADCE KPIs are available for Adjacency OptimisationThe retrieval of the KPIs from the database was explained in chapter 7.4.

The table below shows the necessary ADCE KPIs for the automated Adjacency Optimisation.

Table 2. Necessary ADCE KPIs for Adjacency Optimisation.AttributeDescription

HO attempts to ADCEThe number of handover attempts per adjacency. Can be displayed on map or in browser.

HO success to ADCEThe number of handover successes per adjacency. Can be displayed on map or in browser.

HO success ratio to ADCEThe handover success rate per adjacency. Can be displayed on map or in browser.

Co-channel average received power weightedCo-channel average received power weighted x Co-channel average received power. This is not a measured KPI but calculated by the Adjacency Optimisation tool. Not displayed on map but used by the tool internally.

4. Define mandatory and forbidden constraints

If necessary, create mandatory or forbidden adjacency constraints between certain adjacencies. Mandatory adjacencies cannot be deleted and forbidden ones created by the automated adjacency optimisation algorithm. These constraints must be manually created either on the map as shown in Figure 46 or in the navigator as shown in Figure 47. Constraints are global in Optimizer.Select one of the buttons on the right side of the map as shown in the next figure. Select the source cell with the left mouse button and draw the line to the target cell.

Figure 46. Manual editing of adjacency constraints on a map.The buttons from top to down are as follows:

1. Create bi-directional adjacency

2. Create uni-directional adjacency

3. Create bi-directional forbidden constraint

4. Create uni-directional forbidden constraint

5. Create bi-directional mandatory constraint

6. Create uni-directional mandatory constraint

7. Delete selected adjacencyIn case the constraints are created in the navigator, select Adjacency Management in the pulldown menu in the upper left corner. Select a cell pair, for which one of the constraint options shall be created.

Figure 47. Manual editing of adjacency constraints in the navigator.5. Create adjacency templates

When creating adjacencies, the default parameters are assigned automatically from the parameter templates.

New templates can be created in the CM editor. An example of a creation of a new template is shown in the next figure.

Figure 48. Creation of new template for the adjacency.Select New Template, give the template a name and fill in the necessary parameter values.

Typically the parameter values depend on the source and target cell.

6. Create template assignment rules

Template assignment rules must be created in the Optimizer. System template is used if no rules or conflicting rules exist. This way the new adjacencies will get correct initial values. The rules are not user specific.Rules are based on source and target

cell type (macro, micro, pico in GSM)

frequency band in use (GSM850/900, GSM1900/1800)

assigned cell template name (GSM and WCDMA)

Figure 49. Starting the assignment rule management for adjacency templates.Start the assigning the rules for adjacency templates as shown in the figure above. The window shown in Figure 50 will open up.

Figure 50. Assignment Rule Management for Adjacency Templates. Select a BSC, an RNC, or Global Assignment Rules and click Add. Select category for source or target BTSs.

Click the category point for source and target and select the suitable option from the list shown below.

Figure 51. Selection of categories. New templates created in CM Editor become visible in Optimizer after clicking Refresh. Finally, select a template to be used for a new adjacency that has the specified categories for source and target cells

In this example above: when creating an adjacency from a GSM900 cell to a GSM1800 cell, Optimizer automatically assigns default values from ADCE template called GSM900-GSM1800.11.2 Running the measurement based Adjacency Optimisation

Before the user can start the automated adjacency optimization, there are many common adjacency optimization related parameters that can be edited.

The user has to do the following step in order to start the Automated Adjacency Optimisation.

1. Remember to check that the KPI date and summarization level are set correctly (i.e. according to the need)

2. Select target objects from the Navigator, Map or Browser3. Start the tool as shown in the figure below

Figure 52. Starting the Adjacency Optimisation tool.After selecting the Adjacency Optimisation from the Tools menu, the following window will open up.

Figure 53. Selecting adjacency types and starting the Adjacency Optimisation tool.Only ADCE must be selected for the measurement based 2G adjacency optimization.

Click OK and the following main workspace for Adjacency Optimisation tool shown in Figure 55 will open up.

In case there is some input information missing a following warning might be given. By clicking Details button more information about the problems can be found. Also proposals for corrective actions are given in these windows.

Figure 54. Error and error details windows.

If site or antenna data is found missing, measurements could be corrupted. Therefore, it is extremely important to fix the site and antenna data before the optimisation process (measurements) are started. However, you can continue if you know for certain that the missing sites have no effect on the current optimisation area (including buffer area).

Figure 55. Selecting adjacency types and starting the Adjacency Optimisation tool.4. Select GSM (ADCE) as Adjacency Type from the pull-down menu as shown in the figure above.

5. Check the number of network elements for the scope in the summary table in the bottom of the window.

6. Edit Global BTS Constraints (optional)

Click the button shown in the figure below. This will open up the window for BTS Constraint Management shown in Figure 57.

Figure 56. Edit Global BTS Constraints.

Figure 57. Edit Global BTS Constraints.

Global BTS specific parameters can be modified and saved in a set by clicking the button for creation of a new BTS constraint. Give a name for your new set containing the global BTS constraints.

Define minimum lengths for adjacency list of different frequency bands in order to avoid deletion of necessary adjacencies (i.e. it is not allowed for the adjacency optimization algorithm to reduce/delete the number of adjacencies below the set minimum number).Co-channel Average Received Power for adjacencies can vary considerably between BTSs. Adjacencies can be weighted so that bigger cells are not favored too much. BTS constraints have parameter for this purpose: Co ARP Weighting, which are assigned to the target BTS of an adjacency.This weighting parameter multiplies Co-channel Average Received Power measurement in the Interference Matrix.Finally, remember to save your current BTS constraint settings before closing this window.

7. Assign the new parameter set to BTSs (optional)

Select the new constraint set from the pull-down menu as shown below for each and every BTS in the list separately. Unfortunately, mass modification is not possible. Different constraint sets can be assigned to different BTSs.

Figure 58. Assign Global BTS Constraint set to BTSs.8. Set the common parameters for adjacency optimisation

Figure 59. Common parameter settings for Adjacency Optimisation.

Bidirectional optimisation (recommended)

Creation and deletion of adjacencies between scope and buffer area (recommended for small scopes)

Check maximum and minimum Adjacency List Lengths (this will impact the deletion of unnecessary and creation of new useful adjacencies) Changes to adjacencies between frequency bands can be disabled

Frequency band specific list length settings can be enabled (when selected, fill in the necessary minimum and maximum list lengths in the right side of this window)

9. Set the creation parameters for adjacency optimisation

Adjacency creation is used to find missing adjacencies in the ne