Opt 11 Interference Matrix Principles

Interference Matrix Principles for Optimizer

Nokia Proprietary and Confidential

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© Nokia Oyj

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Contents

The information in this document is subject to change without notice and describes only the product defined in the introduction of this documentation. This document is intended for the use of Nokia's customers only for the purposes of the agreement under which the document 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 document 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 document 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 document are adequate and free of material errors and omissions. Nokia will, if necessary, explain issues which may not be covered by the document.

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

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

NOKIA logo is a registered trademark of Nokia Oyj.

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

Copyright © Nokia Oyj 2003. All rights reserved.

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Contents

Contents

1 About this document .............................................................................4 1.1 Where to find more...................................................................................4 1.1.1 Optimizer documentation .........................................................................4 1.1.2 Geographic Information System documentation ......................................4 1.1.3 Radio Access Configurator documentation ..............................................5

2 About interference matrix generation ..................................................6

3 Interference measurements ..................................................................7 3.1 Measurements needed for Optimizer .......................................................7 3.2 Channel Finder and Defined Adjacent Cell measurements .....................8 3.3 BCCH Allocation (BA) lists .....................................................................10 3.4 BCCH frequencies and Optimizer ..........................................................11 3.5 Identifying measured cells correctly .......................................................12 3.6 Measurement period ..............................................................................13 3.7 Measurements and NetAct capacity.......................................................14

4 Generating interference matrix elements for cells using the same BCCH as carrier..........................................................................15

5 Interference matrix options in Optimizer ...........................................16 5.1 Default interference matrix creation .......................................................16 5.2 Parameters affecting blind spot treatment..............................................17

6 Interference probability formulas .......................................................20 6.1 Average Received Power (ARP) ............................................................20 6.2 Carrier over Interferer Probability (CIP)..................................................22

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About this document

1 About this document This document gives an overall picture of Nokia NetAct Optimizer 1.1. Interference Matrix generation

1.1 Where to find more

1.1.1 Optimizer documentation

• For information on the process of optimising a network using Optimizer, see Optimising a Network Using Optimizer.

• For detailed technical information on Optimizer, see Optimizer Technical Reference Guide.

• For information on Optimizer database tables, refer to Database Description for Optimizer.

• For detailed instructions on how to use the Optimizer applications, see the following helps:

− Optimizer Main User Interface Help

− Frequency Allocation Help

1.1.2 Geographic Information System documentation

• For information on the Geographic Information System, see the following documents:

− Geographic Information System Principles

− Managing GIS Maps

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About this document

1.1.3 Radio Access Configurator documentation

• For information on the Radio Access Configurator, see the following documents:

− Radio Access Configurator Principles

− Radio Access Configurator Technical Reference Guide

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About interference matrix generation

2 About interference matrix generation The interference matrix represents the interference relations between cells. Interference can be computed or expressed with different mathematical methods such as ARP (Average Received Power) and CIP (Carrier over Interferer Probability). In Optimizer, interference is computed based on measurements that have been made in an operated network.

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Interference measurements

3 Interference measurements Optimizer uses measurement reports created by the Reporter module of NetAct. When the measurements are ready, measurement data can be retrieved from Reporter to Optimizer via Optimizer’s main user interface.

BSC S10 provides the measurements that are needed for mobile measurement based optimisation of adjacencies and frequencies of the network. Nokia NetAct contains the support for the whole automated planning process, and it uses the BSC measurements as well as the network configuration database as inputs to the optimisation logic. The measurements used are Channel Finder Measurement in release S9 and Defined Adjacent Cell Measurement, new in S10. Both measurements are optional in BSC and available for Optimizer.

The Radio Access Configurator (RAC) module of NetAct is also needed in order to manage Nokia BSS elements. Optimizer uses the functionality of RAC to get the actual network configuration.

In addition to the interference matrix, also traffic data is utilised when a new frequency plan is computed. The interference matrix contains a quantitative description of interference relation and is not weighted with traffic. However, traffic measurements are taken into account in the cost function of the Frequency Allocation tool. The interference matrix can also be exported to be used with a preferred external AFP tool. Other relevant factors are taken into account by changing the parameter settings of the Frequency Allocation cost function.

3.1 Measurements needed for Optimizer

Optimizer needs the following measurements to be switched on for the cell at BSC level (the names of the actual measurements are in brackets):

• Handover performance, for deleting unnecessary adjacencies (Handover Measurement).

• Defined Adjacent Cell measurement and Channel Finder measurement, for interference and missing adjacencies (Def. Adj. Cell Measurement and Channel Finder Measurement).

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There is also an Undefined Adjacent Cell measurement (Undef. Adj. Cell Measurement), which is very similar to the Channel Finder Measurement. The Channel Finder Measurement is, however, much more useful than the Undefined Adjacent Cell measurement.

• Traffic (Traffic Measurement).

For details on these measurements, see reference documentation for S10.5.

The measurement scope and measurement period are defined in the Administration of Measurements application in NetAct. The measurements are activated per BSC, and all the BTSs in a BSC collect the information. For more information on this, see Administration of Measurements Help.

Defined Adjacent Cell measurement and Channel Finder measurement should be started simultaneously and with the same measurement period.

3.2 Channel Finder and Defined Adjacent Cell measurements

Mobiles report six strongest neighbours, which provides enough data to build a reliable interference matrix. Data is collected from several mobiles moving in a carrier area over a long period of time, and the six strongest neighbours reported are then different.

BSC Counters: Defined Adjacent Cell Measurement

The 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 CIR for each serving cell/ defined adjacent cell pair are provided. These counters give the number of samples in each of the user-defined CIR 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

• 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.

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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. BSC counters: Channel Finder Measurement

The channel finder measurement registers statistics on cells which have not been defined as adjacent cells but which are among those six neighbouring cells that the MS (mobile station) receives best. This measurement type collects one block of results for each cell.

One block (cell) of results contains six counters:

• Average strength of the downlink signal

• BCCH + BSIC

• Standard deviation (sum of squares of signal strengths)

• Three sample counters

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 formulas are written and also on the software itself.

The following table summarises 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 undestand; therefore, the meaning of counters n1, n2 and n3 in the table has been translated to CIR format.

n1 n2 n3

ICR ICR < DB1 DB1 <= ICR <= DB2 ICR > DB2

CIR CIR > -DB1 -DB2 <= CIR <= -DB1 CIR < -DB2

Table 1. Computing ICR and CIR from BSC measurements

The interval threshold between n1 and n2 is termed DB1. Its value may be for example -9 dB. The interval threshold between n2 and n3 is termed DB2 and its value may be for example 8 dB.

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3.3 BCCH Allocation (BA) lists

Before measurements can be started for Optimizer, RAC needs to send a list of BCCH frequencies to be measured to the BTS(s). This is done by using a BCCH Allocation (BA) list. When the measurements are ready, the original BA list is returned. The original BA list contains the BCCH frequencies of the adjacent cells of the BTS. The BA list must contain all the BCCH frequencies used in the network in order for all the cells to be measured. If a frequency is missing from the list, the cells in that frequency are not measured.

The idea of having a temporary BA list for measurements is to have a list of the BCCHs of all the cells, including undefined cells, where a handover could be made. Before making the connection to a neighbour cell, mobiles first listen to the BCCH in the BA list to verify sufficient signal strength and quality. By adding all possible BCCHs to the BA list for duration of the measurement period and measuring all surrounding cells, all the required data for correct adjacencies and frequency planning can be collected. If there are less than 32 BCCHs, both the current and possible adjacent cell BCCHs are included into the BA list.

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. However, it has to be verified that all the BCCHs of the currently defined neighbours are included into the BA list in order to keep the NW performance. Note that the cells included in the BA list in two phases have interference matrix values two times larger than cells included in the list only once.

The temporary BA list is defined for the measurement period and the original BA list is returned once the measurements are completed. The BA list change as well as measurement scheduling can be done using a RAC command line tool.

In order for the BTS to be able to receive the BA list, the double BCCH Allocation feature must be on in the BTS.

Also, no configuration changes should me made during the measurement period, as the BA list together with other parameter data will be returned after the measurements are ready, and any configuration changes will be overwritten. Overview of BSS2132: Double BCCH Allocation List

With the Double BCCH Allocation List feature the user can define a list of BCCH carriers to be used in cell selection and reselection by the MS being in the Idle State. The list is sent to the MS in System Information Message type 2 on the BCCH and the MS may store it when powering down. Now, the MS does not need to search through the whole band when powering up. If the list contains all the BCCH carriers of a certain geographical area of a PLMN, the MS can use it to search the suitable RF channels quickly in order to camp on a cell.

The BSC operator is able to add, remove and output carrier frequency numbers on the Idle State BCCH Allocation lists with the MML commands. For a particular cell it is possible to define whether it uses one of the Idle State Lists

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or the Neighbour Cell List of its own at System Information Message 2 on BCCH. If the cell is not attached to any of the Idle State Lists, the Neighbour Cell List is used as a default list. The frequency of the BCCH carrier of the cell itself is always added to the BCCH allocation in System Information message 2.

Another selection can be made concerning the list in System Information Message 5 on SACCH. The default is the Neighbour Cell List, but if an Idle State List is attached to the cell to be used in System Information Message 2, the same list can also be used in System Information Message 5 on SACCH. If one of the Idle State Lists is selected to be used on SACCH, it is possible that the list contains carrier frequencies that are not the BCCH frequencies of the actual handover neighbours. In this case, the MS measures signals on these frequencies but no handovers are attempted towards those undefined cells. With the commands of the BCCH and Mobile Allocation Frequency List Handling (BAZAAR) command group, the user can create, modify, delete and output BCCH frequency list objects in the BSS Radio Network Configuration database (BSDATA).

The user can attach any of these lists to certain BTSs with the commands of the command group Base Transceiver Station Handling (PBTHAN). The Double BCCH Allocation List is an optional feature in the BSC.

For more information, see Radio Network Configuration Management.

• Activating and testing BSS2132: Double BCCH Allocation List

• Deactivating and testing BSS2132: Double BCCH Allocation List

3.4 BCCH frequencies and Optimizer

The first release of Optimizer is recommended to be used with dedicated BCCH frequencies, and currently up to 32 BCCHs are supported. The BCCH block does not need to be a continuous band; also several slots will do if they are dedicated for BCCH use only.

It is possible to measure also a mixed band, but in this case more manual work is needed. If there are more than 32 channels to be measured, the measurements have to be carried out in several phases. In each phase the BA list has to be modified to carry on the frequencies where measurement results are wanted. As all the BCCHs of the current adjacencies have to be included in the BA list, the practical amount of frequencies in a measurement period is 32 - #neighbours.

Note that the amount of TCH frequencies is not limited in the dedicated BCCH case, and even if only the BCCHs are measured, the inter-cell dependency is also applicable for TCH frequencies. As the signal strengths of the surrounding cells are studied in the measurement period, the information is valid for TCH frequencies also. In the frequency allocation phase, different interference thresholds are given to TCH frequencies and BCCHs, thus achieving tighter re-use for TCH frequencies with a higher level of expected interference.

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3.5 Identifying measured cells correctly

In mobile measurement reports each measured cell is identified with BCCH frequency and BSIC only. Generally, there are several cells using the same BCCH-BSIC combination. Therefore, when Optimizer is post-processing the data from mobile measurement reports, it cannot always be known for certain which cell has actually been measured by the mobile. Any cells with matching BCCH-BSIC might be the cells that the mobiles have been measuring. Sometimes it is enough to check the distance between cell A and the measuring cell and compare it to the distance between cell B and the measuring cell. If the distances are, say 10 km to A and 70 km to B, it is evident that cell A has been measured.

In very dense networks it may happen that even with good planning of BSICs, distances between cells with an identical BCCH-BSIC combination become short. Such an example is shown in the figure below. The distance to cell A is 2.1 km and to cell B 1.8 km. It seems that by looking at the distance only BCCH 1 and BSIC 2 correspond to cell B as it is closer. Looking at the figure and taking into account the antenna azimuths, it seems more likely that mobiles in the serving cell ("Macrocell" in the figure) have measured cell A. This is because the antenna of cell A is pointing more or less towards the serving cell's service area, whereas the antenna of cell B is pointing away from it.

In Optimizer, the user can choose whether distance only or both distance and antenna azimuths are considered when any BCCH-BSIC combinations is mapped to an actual cell identifier. This selection is done in the Measurement Source dialog accessed from the Optimizer main user interface. Azimuths can only be considered if they have been entered to the database from which Optimizer collects cell related information. It is strongly recommended that azimuth is always used when possible, that is, the user is encouraged to enter the antenna azimuths to the appropriate database. This is extremely important especially in cases where it is known that in the network there are BCCH-BSIC combinations which are often reused.

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Figure 1. Example of short distances between cells using an identical BCCH-BSIC combination causing the wrong cell to be measured

3.6 Measurement period

Optimizer requires measurements from a longer period (about one week), so that the measurements have to be scheduled for some hours for several days. The measurements are sent from the BSC to Reporter after each day. Running measurements for a long time causes extra load to the network and also to the MS handover behaviour.

For identifying unnecessary adjacencies, measurements can be done during several days. When toggling the BCCH band and measuring received signals, the list of correct adjacencies can be generated by measuring for a couple of hours (3-4 hours) during a few days (2-3 days). The required time depends on the traffic profile in the network.

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3.7 Measurements and NetAct capacity

Both Channel Finder and Defined Adjacent Cell measurements are not on by default but they are started when needed. They cause some additional load to the network but nothing remarkable.

Measurements can be run for a long time period (several hours) and are processed in the BSC at the end of the period. This will reduce the amount of data to be transferred to NetAct and thus, it reduces the system load. It is also possible to set when the BSC sends the measurement file to Reporter.

Increasing the amount of BCCHs in the BA list to include all possible BCCHs instead of just the amount of current adjacencies increases the load in the network during the measurement period. However, this is not a remarkable increase and does not cause any detectable decrease in performance.

Nokia NetAct contains advanced functionality for analysing the load caused by the measurements. NetAct Administrator provides a tool, Capacity Indication Tool, that can be used to accurately determine the load of the existing measurements in the network. By starting the measurements required by Optimizer in a small network area (one BSC, for example), it is possible to get information about the additional network load.

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Generating interference matrix elements for cells using the same BCCH as carrier

4 Generating interference matrix elements for cells using the same BCCH as carrier

While in measuring mode, mobiles measure the power level of as many BCCH carriers as is listed in the BA list, and decode their BSIC in order to determine the cell emitting the signal. Any cells having the same BCCH with the serving cell are generally not measured. This is because the serving cell signal is usually much stronger and covers all other signals on the same frequency. These co-channel cases are seen as blind spots in the interference matrix. Even though the measurements show no or a very small value for these co-channel BCCH cell pairs in the interference matrix, some of these pairs may in reality interfere with each other. Therefore, a method is introduced in Optimizer to avoid missing these blind spot interference relations. This method is described in the following section.

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Interference matrix options in Optimizer

5 Interference matrix options in Optimizer This section describes the options that are used when an interference matrix is generated from new measurements. The majority of the parameters describe how blind spots are treated in Optimizer. The interference matrix options are stored in a file in the Optimizer server side. Two of the options – Population method and Penalty method - can be changed in the user interface, but the rest of the options can be set only in the options file. The name of the file containing the parameters is InterferenceOptions.xml. The options file is located in the directory C:\Program Files\Nokia\NokiaOSS\configurator\optimizer\oserver\conf\ms svc\.

The InterferenceOptions.xml is not in the above-mentioned directory by default. It appears after the first measurement retrieval.

5.1 Default interference matrix creation

A new interference matrix is created by default as follows:

1. The current actual configuration (BCCH allocation and BSIC coding) is loaded.

2. The old interference matrix is loaded if it exists.

3. Blind spots are enumerated based on the actual BCCH allocation. If there is some interference data corresponding to each blind spot, nothing is done; otherwise, some small interference (Co-channel Average Received Power = 1, and co-channel interference probability in downlink = 0.05, that is, 5%) is assigned to the blind spots. Note that if the blind spot had some value in the old interference matrix, then no new assignment is made but the old data is kept.

4. New measurements are loaded and interferers are recognised to each BTS experiencing interference by using distance and antenna bearing (azimuth) data. The measurements overwrite the current interference matrix. However, where no new data exists, old data remains.

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5. Finally, the new interference matrix is saved into the Optimizer database.

This default procedure can be altered by changing the interference matrix options. Two of the options (Population Method and Penalty Method) can be changed in the user interface or in the InterferenceOptions.xml file. Other options can be changed only in the above-mentioned file.

5.2 Parameters affecting blind spot treatment

Population method

The population method can be set in the Optimizer main user interface. The options are:

• Keep Blind Spots Only This is the default value. Blind spots are recognised in the actual allocation. A new interference matrix is calculated based on the new measurements, but data into the blind spots is acquired from the old interference matrix.

• Overload A new interference matrix is calculated based on new measurements and it is loaded on top of the old matrix. Where data source cells overlap, new data replaces the old data. However, where no new data exists, old data remains.

Instructions for setting the population method are given in the Optimizer Main User Interface Help. Penalty method

The penalty method can be set in the Optimizer main user interface. The options are:

• Distance Only Only distance is used in interferer recognition and in sorting BTSs in blind spots. Use this method only if antenna azimuths are not available.

• Distance and Antenna Bearing Both distance and antenna bearing are used in interferer recognition and also in sorting BTSs in blind spots. This is the recommended method.

Instructions for setting the penalty method are given in the Optimizer Main User Interface Help. Blind spot limitation method

The blind spot limitation method can only be set in the InterferenceOptions.xml file.

Enumeration name Explanation

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LIST_LENGTH_LIMITED The number of blind spots per BTS is limited by a list length limit. The name of this limit is blindSpotListLengthLimit. This is the default value of the blindSpotLimitationMethod.

DISTANCE_LIMITED The number of blind spots per BTS is limited by the distance of BTSs from each others. This distance is given in the parameter blindSpotDistanceLimit.

TAKE_ALL Interference relations are created into all new blind spots.

NO_NEW_BLIND_SPOTS No new interference relations are created even if there are blind spots between BTSs.

Table 2. Method for selecting BTSs in blind spots for automatic interference creation into interference matrix (blindSpotLimitationMethod)

Other options and parameters

The parameters and options described in the table below can only be set in the InterferenceOptions.xml file.

Name Explanation Default value

Min Max Unit

“blindSpotListLengthLimit” Used to restrict the number of BTSs to be assigned a default interference value (ARP or CIP), if this limitation is used.

3 0 50 -

“blindSpotDistanceLimit” Used to restrict the number of BTSs to be assigned a default interference value (ARP or CIP), if this limitation is used.

20 0 70 “km”

“blindSpotCoARP” Default interference value (ARP) that is put into blind spot if there is no value previously.

1 0 63 RXLEV

“blindSpotCoCIP” Default interference value (CIP) that is put into blind spot if there is no value previously.

0.05 0.0 1.0 -

“coAdjDifferenceARP” Used to define the difference between co-channel ARP and adjacent channel ARP values.

18 0 63 dB

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Table 3. Other options and parameters in the InterferenceOptions.xml file

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Interference probability formulas

6 Interference probability formulas There are several ways to calculate an interference matrix from mobile measurement reports. Two ways are described here, as they are used in Optimizer. The difference between the two ways is that CIP (CIR probability) takes into account carrier strength in addition to measured cell signal strength, whereas ARP (Average Received Power) method only considers power received from the measured cell. Either method can be used to both frequency and neighbour planning.

6.1 Average Received Power (ARP)

Average Received Power (ARP) is a measure for interference or overlap between any two cells. It is simply the average RXLEV measured from cell j by mobiles served by cell i. As cell i receives typically also measurement reports from mobiles where cell j is not included (only 6 cells fit to one report), a zero value is assumed for cell j for those reports.

ARPi,j, that is ARP from cell j to cell i, is computed with the following formula:

Figure 2. Equation for Average Received Power

where

• ARPi,j = Average Received Power from cell j to cell i.

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• Pi,j = Average RXLEV measured from cell j by mobiles served by cell i (average counted only over such reports where cell j is included).

• Ni,j = The number of such mobile measurement reports received by cell i, where cell j has been included, Therefore, Pi,j*Ni,j is simply the sum of RXLEV samples from cell j to cell i.

• Mi = The number of all mobile measurement reports received by cell i, no matter if cell j is included in the report or not.

• nki,j = The number of such mobile measurement reports received by cell i

where cell j is included and where RXLEVj - RXLEVi belongs to interval k. BSC classifies each sample to these I/C intervals. For details, see BSC S10.5 specifications.

The RXLEV value interval of ARP is [0.0, 63.0] although in practice the values are likely to be from the lower side of the scale. This is because measurement samples are from all over the cell i service area, and it is thus unlikely that any one cell would be measured all over that area (co-located 1800 cells may be exceptions).

Received signal strength Pi,j and ARP (GSM 05.08; 8.1.4) mean the following values:

• 0 less than -110 dBm

• 1 = -110 to -109 dBm

• 2 = -109 to -108 dBm

• ...

• 62 = -49 to -48 dBm

• 63 = greater than -48 dBm

In allocation, also adjacent channel interference should be treated. With ARP the computation can be made as follows:

Figure 3. Equation for Average Received Power approximation for adjacent channel

where

• ARPi,jadj = Average Received Power approximation for adjacent channel

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• ARPi,jco = Average Received Power for co-channel, equal to ARPi,j

defined in the equation for ARP where a shorter notation was used for convenience.

The logic in estimating the adjacent frequency interference from co-frequency interference is that the GSM specifications define that interference leaking from adjacent GSM frequency should be at least 18 dB lower than interference in the same conditions from the same GSM frequency.

6.2 Carrier over Interferer Probability (CIP)

C/I probability (CIP) is a probability of a random call experiencing interference more than a given threshold, that is, CIP = P(CIR < t), where threshold t may be 9 dB, for example. CIP is computed from measurement reports with an equation for co-channel interference and with an equation for adjacent channel interference.

Figure 4. Carrier over Interferer Probability for co-channel formula

where

• CIPi,jco = Estimated interference from cell j to cell i on the same

frequency.

• n2i,j = the number of samples from cell j to cell i in CIR category n2.

• n3i,j = number of samples from cell j to cell i in CIR category n3.


Similarly, CIPadj (or C/Ia(%)) is computed from measurement reports with the following formula:

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Figure 5. Carrier over Interferer Probability for adjacent cell formula

where

• CIPi,jadj = Estimated interference from cell j to cell i on an adjacent

frequency.

• n3i,j = number of samples from cell j to cell i in CIR category n3.


CIP values are represented as floating point numbers with four number accuracy (two decimals). The interval is [0.01,100.0] and unit percentage (%).

Note that CIP estimates the portion of time which any call receives weaker CIR than a given threshold. Usually about 9 dB is considered as a good threshold for good quality call. When setting parameters DB1 and DB2 in BSCs, note that BSC uses ICR and not CIR when allocating each sample to a corresponding interval (n1, n2 or n3). Therefore, if CIPi,j

co is wanted to represent probability to have weaker than or equal to 9 dB CIR, then DB1 should be set to -9 dB in the BSC. Note that the value of DB2 does not affect to value of CIPi,j

co . If 10 dB CIR is acceptable for co-channel and 18 dB attenuation from adjacent channel is assumed, then CIR of -8 is acceptable for adjacent frequency. Therefore, DB2 should be set to +8 dB in the BSC.

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Index

Index

A ARP, 6, 20 Average Received Power, 6, 20

B BA list, 10, 14 BCCH Allocation list, 10 blind spot, 17 BSC counter, 8 BSIC, 12

C Carrier over Interferer Probability, 6, 22 CIP, 6, 20

D Double BCCH Allocation list, 10

I interference matrix, 6

interference matrix options, 16

M measurement period, 13 measurement report, 7 Measurement source dialog, 12

N NetAct, 14

R Radio Access Configurator, 7 Reporter, 7 RXLEV, 20

T traffic data, 7

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Documents

Opt 11 Interference Matrix Principles