frequency planning procedure netact optimizer

Frequency Planning Standard Operating Procedures using NectAct Optimizer

Author: Date: 25 February 2010 Version: 2.0 Sec. Class: Official use

Table of Contents

1. DOCUMENT CONTROL: ................................................................................................................3

Revision History............................................................................................................................................3

2. OPTIMIZER BASICS.......................................................................................................................4

3 MEASUREMENT BASED ANALYSIS............................................................................................5

4 DIFFERENCE BETWEEN PREDICTIONS & MEASURMENT BASED TOOLS ..........................5

5 OPTIMIZER WORKING FLOW CHART.........................................................................................6

6 PRE OPTIMIZER TASKS................................................................................................................7

7 OPTIMIZER......................................................................................................................................9

7.1 ADJACENCY OPTIMIZATION......................................................................................................13

7.2 FREQUENCY OPTIMIZATION .....................................................................................................15

8 SUMMARY.....................................................................................................................................22

Frequency Planning SOP Kamran Afzal

Author: Kamran Afzal of 22 Date: 25 February 2010 Confidential

1. DOCUMENT CONTROL:

Revision History

S.No Action Person Version 1 Document Mr. Kamran Afzal 2.0



2. OPTIMIZER BASICS NetAct Optimizer is used in the statistical and/or network wide optimization process in NetAct. Optimizer provides visibility to current network behavior by combining the actual GSM network configuration parameters and measured performance statistics with advanced visualization and analysis functionality. Parameters can be optimised manually for small changes or automatically by choosing from the range of optimisation solutions provided by Optimizer. Optimizer can be used for a single cell or for a whole region. The result of optimisation algorithms can be visualized on a geographical map before downloading the optimisation plan to the network. The plan with the changed parameters is sent to RAC where it is validated and provisioned to the network. Some of the basic functionalities of Optimizer includes • Optimizer uses statistical performance measurement data. As the input data for algorithms is accurate (measurements of a real network), the output is also more accurate than with a signal propagation estimate based process in Asset. • Using measurements makes the tuning process faster. Instead of heavy raster map based calculations - where, for example, the interference matrix is calculated by considering signal strengths in each map pixel - a mobile measurement report is used. When the data is processed in Optimizer, only some analysis is needed. • Increased level of automation. With Optimizer, the whole optimisation cycle is faster than with planning tools. As Optimizer is implemented in the NetAct Framework, the actual configuration data and measurement reports are available for processing. The network topology in Optimizer is always consistent with the actual network data. When running Optimizer for the first time, some customizing is needed, such as parameters needed to guide the generation algorithms. Once the parameters are set, the next optimisation round is more effortless.



3 MEASUREMENT BASED ANALYSIS Interference Matrix, which is primarily based on interference related measurements but can also be complemented with predictions, is the main core of Optimizer.

Interference matrix represents the interference relations between cells. Interference can be computed or expressed with different mathematical methods such as ARP (Average Received Power), CIP (Carrier over Interferer Probability) or FEP (Frame Erasure Probability).

Interference in Optimizer is primarily computed based on measurements that have been made in an operated network. However in case measurements are not satisfactory because some of missing data (for example, as in the case of new objects, or blind spots), it is possible to use predicted interference values to complement measurements. This is done by combining data from several sets and by defining a priority for the sets to be used.

4 DIFFERENCE BETWEEN PREDICTIONS & MEASURMENT BASED TOOLS Interference Matrix is generated in both predictions and measurement based tools. This interference matrix is then used in the calculation of cell interference from other cells. Optimizer generates the interference matrix based on following measurements

• CIP (Carrier to Interference Probability) • ARP (Average Received Power) • FEP (Frame Erasure Probability)

Carrier over Interferer Probability (CIP) is a probability of a random call experiencing interference that exceeds a given threshold. Usually, an adequate threshold for good quality calls is considered to be about 9 dB. CIP is represented as a probability factor having floating point numbers with four number accuracy (two decimals). The interval is [0.01,100.0] and unit percentage (%). The Average Received Power (ARP) is a measurement for interference or overlap between any two cells. It is simply the relative rx level measured from one cell by mobiles served by another cell. ARP is represented as floating point numbers with four number accuracy (two decimals). The interval is [0.0,63.0] and unit RXLEV. Frame Erasure Probability (FEP) is an estimated probability for a speech frame to be erased. FEP is represented as a probability factor having floating point numbers with four number accuracy (two decimals). The interval is [0.01,100.0] and unit percentage (%). Interference Matrix in P rediction Based Tools is calculated with the help of predictions. The predictions usually depend upon propagation models. The model describes the behaviour of RF waves in certain environment and clutter. The Interference matrix generated with the help of predictions will also be used for determining the interference values between cells but this value will not be the real value.



5 OPTIMIZER WORKING FLOW CHART Below are the steps which describe implementation procedure for optimizer. Total duration depends upon the area under observation. The area selection can be done per BSC or geographical area (depends upon the requirement).

Select Area Select FP Strategy

Attach BAList & En.

Measurments

After 1

Week

disable Measurments

/BAlist

Run Adjacency

Optimization

Implement Adjecencies in Network

Run AFP

Figure 1: Optimizer working flow chart



6 PRE OPTIMIZER TASKS Few things need to be considered in selecting the Area of Interest or BSC for good results

• Minimum or no outages; sites have to be very stable • Urban with minimum overshooting • Freeze must be implemented before start of live measurements till benchmarking is

done Once the Area is selected then follow the below mentioned steps

1. Attach BAlist of 900 plus 1800 to all the cells which are to be optimized with Optimizer. The BAList will contain complete BCCH ARFCN’s

2. Once BAlist is attached and verified then CF & DAC measurements are to be enabled

in the selected BSC for one week. The weather conditions in this time must be very stable

3. After one week stop the measurements and detach the BAlist

Database Update Once Pre Optimizer tasks are completed then database of the selected area needs to be updated. This process will be done through Antenna Data Editor tool provided in Netact.

FIGURE 2: ANTENNA DATA EDITOR MAIN VIEW



• Export the required BSC in “csv” format. FILE Export Export as csv

• Update the “csv” file with latest RF OnAir Database Sheet

• Import back to Antenna Data Editor. FILE Import

Figure 3: Antenna Data Editor Import/Export

The updated data will automatically reflected in optimizer. Optimizer gets the data from Netact database and any changes in Antenna Data Editor will effect the Netact Database so it is recommended to double check the data before importing in the tool. Export the data again from Optimizer and check the authenticity with RF Database, it must show the updated values now.



7 OPTIMIZER Once database is updated then Optimizer is used to retrieve measurements and optimization From Netact Configuration window click Optimizer Tool

Figure 4: NetAct Main View Creating Scope Optimizer will define the scope and buffer areas for optimization. The cell in scope will be planned and buffer areas will be considered as read-only.

Figure 5: Defining Scope of required BSC



Once the scope is created then BSC/Cells will be shown in Scope window. Scope needs to be activated after that BSC Create New Scope Activate Scope

Figure 6: Scope activation The Scope area in the map will be shown in colour while the buffer area will be fainted. Measurement Retrieval The CIP and ARP measurements are now retrieved in Optimizer Optimizer Tools Network Statistics Preparing GSM IM Creation This will open a step window through which BAList and measurements can be enabled/disabled from your workstation. But this will not be the case in here as these changes are sent through CM teams as separate MAR’s. So for this step just proceed further by clicking next and selecting appropriate band for Optimization (i.e., 900 or 1800)



= Figure 7: Preparing GSM IM Creation

Once finished is clicked then Interference Matrix window is automatically opened.

Figure 8: Interference Matrix table



Measurements will be retrieved for both CIP and ARP separately.

Figure 9: Interference Matrix table with CIP and ARP values

First select the CIP from interference type and click the Retrieve tab. Measured set will be shown after that which can also be viewed by clicking view tab. Once retrieval is complete then click Run Predictions. This will calculate the blind spots (where cell id is not decoded in measurements due to coverage hole or co BCCH-BSIC issue) Priority needs to be given to each set. Higher priority foe measured set (1 to Measured and 2 to Simple Predicted)



7.1 ADJACENCY OPTIMIZATION Adjacency Optimization can be started after retrieval of measurements. ARP will be used to perform Adjacency optimization.

Figure 10: Neighbour Planning Tools Adjacency Optimization Adjacency Optimization Select ARP as interference type and click OK. The adjacency window will appear. In the Rules tab select Sync & Two way Neighbours. Neighbours can be created/deleted by selecting appropriate tabs



Figure 11: Neighbour Creation Neighbour Cre ation: For Neighbour creation, select the maximum distance and angle between antennas. Co channel ARP value needs to be set. This number of neighbour creations will increase with less value Neighbour Deletion: For Neighbour deletion, ceck the distance and maximum theta angle Click Start Optimization The newly added and deleted neighbours will be shown in browser window The Neighbours are then verified manually. Once verified they must be implemented by sending Neighbor addition/deletion MAR to CM. After the implementation verification needs to be performed again via Netact. These Neighbours will be automatically updated in Netact and can be viewed through Optimizer To view the neighbours, select the cell right click view adjacencies



7.2 FREQUENCY OPTIMIZATION For frequency Optimization click Tools->frequency optimi zation-> frequen cy optimization-> Select CIP+ARP-> OK

Figure 12: AFP After this the Frequency Optimization window will appear. Showing the scope and buffer BSC’s Each BSC can be selected to see the cells present in it. There are a number of options which can be changed in order for the AFP algorithm to run in a specific way. These Option include

• Frequency band • Layers • BSC • Scope BTS • MAL’s • Frequency Groups • Manual Separation • Separation Violation Penalties



Figure 13: AFP options

These options will be selected one by one Show Frequency Bands Select the required band to plan Show Layers Select BCCH/TCH layers to be planned

Figure 14: AFP Layers



Show BS C Sel ect required f requency group to cells – A ssigned ARFCN’s after planning will also be shown in this tab

Figure 15: AFP BSC Show Scope BTS BTS priorities are set here (Low, Normal, High)

Figure 16: Scope BTS



Show MALs Select/modify the Malist to be assigned

Figure 17: MALs tab Show Frequency Groups Modify the frequency in a band for assignment (less BCCH for example)

Figure 17: Frequency Groups



Show->Seperation Violation Penalties(Default Recommended) Changes the cost of the Interference Matrix. However violation can be changed if required, equivalent changes should be made for all Freq Group/TRX Layer pair. This shows the cost and penalties between different layers. If a cost is broken then penalty will increased for that layer in AFP algorithm.

Figure 18: Separation Violation Once all these settings are saved then click start optimization. This will open a new AFP window



Figure 19: Start Frequency Optimization

Analysis Requirement must be entered in this tab about what to plan. Frequency Plan The AFP tabs is used for frequency optimization

Figure 20: AFP Tab



AFP Algorithm can be run in three different types

AFP->Fast: Starts from current Plan. AFP->Optimization: Starts from zero, but runs for very less time AFP->Accurate: Starts from zero. Runs for the Specified Time

Select the required algorithm type and click allocate. Optimizer will take some time to plan frequencies and will generate the results

Figure 21: Optimizer Results Results will be shown on BSC/BTS/Layer level. Appropriate graphs and values will be shown against the algorithm and each cell. After getting the results go to Show BSC and copy the data with headers. Paste this data in excel sheet so that it can be verified with other tools as well New frequencies will now be shown as channels (Planned). This can be verified either on Optimizer or on Mapinfo/Asset



8 SUMMARY

• Select the area which is stable with minimum number of outages

• Enable freeze on the Area till benchmarking is complete

• 900 and 1800 combined BAList must be attached to cells (only one band BAList

will result in HO Drops between bands)

• Disable the measurements and detach the BAList after one week

• Run the Adjacency optimization before AFP

• Verify the Neighbours

• Implement the Adjacency changes in network before running AFP

• Try AFP with different algorithm methods and for Accurate method run the AFP overnight

• Verify the results in Asset.

frequency planning procedure netact optimizer

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