Date post: | 01-Dec-2015 |
Category: |
Documents |
Upload: | mansonbazzokka |
View: | 101 times |
Download: | 1 times |
1 © Noki a Si emens N etwor ks Presentation / PLe 23.8.2010For public use – IPR applies
NetAct Optimizer 3.0 for GSM
GSM Interference Matrix
2 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Nokia Siemens Networks AcademyLegal notice
Intellectual Property RightsAll copyrights and intellectual property rights for Nokia Siemens Networks training documentation, product documentation and slide presentation material, all of which are forthwith known as Nokia Siemens Networks training material, are the exclusive property of Nokia Siemens Networks. Nokia Siemens Networks owns the rights to copying, modification, translation, adaptation or derivatives including any improvements or developments. Nokia Siemens Networks has the sole right to copy, distribute, amend, modify, develop, license, sublicense, sell, transfer and assign the Nokia Siemens Networks training material. Individuals can use the Nokia Siemens Networks training material for their own personal self-development only, those same individuals cannot subsequently pass on that same Intellectual Property to others without the prior written agreement of Nokia Siemens Networks. The Nokia Siemens Networks training material cannot be used outside of an agreed Nokia Siemens Networks training session for development of groups without the prior written agreement of Nokia Siemens Networks.
3 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
At the end of this module the trainee should be able to:
Prepare for the network optimization by creating, verifying, importing and exporting an interference matrix
Find problem cells that cause interference over a long distance
Module Objectives
4 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
GSM Interference Matrix
How can I create an Interference Matrix?
How do I check the Interference Matrix on the Map?
How can I find the cells that cause interference far away?
5 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
IM Basics
Interference Matrix represents the interference relations between cellsInterference can be computed or expressed with different mathematical methods such as• CIP (Carrier over Interferer Probability), or• ARP (Average Received Power),IM set contains CIP, ARP values for co-channel and adjacent channel between every cell pair in the BSCIf old IM sets are available (from earlier optimisations) it is recommended to combine them with the new IMs to reduce blind spots• Old IM sets are given lower priority than new setsIn case of missing or low quality measurement data, it is possible to use predicted interference values to complement measurementsInterference Matrix is used in Optimizer as an input for GSM Adjacency Optimization and GSM Frequency OptimisationIMs can be exported and imported
6 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Matrices Tab - Measurement Retrieval
• Open Interference Matrices tool view• Select one or more BSCs• Select Interference Type CIP• Retrieve measurements
7 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Common Parameters for Retrieval
Insert measurement start date and end dateHow many blind spots should be generated?If interference value is below the selected threshold, it is ignoredDefault values are given to the generated blind spot interferers
8 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Other Parameters for Retrieval
9 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Prediction Parameters
Select a one or more BSCs
Propagation Factor is the exponent of the link loss calculation
10 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Measurement Sets
• Assign priority 1 to the most important (newest) set of measurements
• Priority is needed for every set to be included in the IM
11 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Managing Interference Matrix
Without priority there is no interference data available in OptimizerPriority needs to be assigned for each Interference type separatelyImport and Export possible (CSV format)
12 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Priority
Priority settings are user specific
If a set has no priority assigned to it, it is not taken into the combined matrixA combined set may contain 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 cellpair 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 used
13 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Matrix
How can I create an Interference Matrix?
How do I check the Interference Matrix on the Map?
How can I find the cells that cause interference far away?
14 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Matrix on Map
Interference Matrix values between cells can be seen on the map
For each pair of cells the value above threshold is shown on themap as a line between the cellsInterference values represent Carrier over Interference Probability, Frame Erasure Probability values from the combined IM
• Current allocation is not taken into account
• Values exist also between different frequency bands
15 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Lines
Select Other... forInterference Line visualisation
Select Interference Matrix Value
16 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Line Parameters
Select a cell(s) from the map
17 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Exercise
View and visualise measured, predicted or combined sets
• It is enough if one person retrieves a setExport interference matrix in CSV format and study the contents
• Try selecting different sets (MEASURED, PREDICTED)• Select different interference types (CIP, ARP)
Visualise Interference Matrix Values on the map
18 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
GSM Interference Matrix
How can I create an Interference Matrix?
How do I check the Interference Matrix on the Map?
How can I find the cells that cause interference far away?
19 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Analyzer
Interference Analyzer tool allows you to find problematic cells that cause interference over great distances in the network
Only measured Interference Matrix can be used (priority set)
Select BSCs, sites, cells or master BTSs from the Navigator oruse the active scope
20 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Analyzer
Example: Show me the cells that interfere over 8 km with > 1.0 % CIP
Adjust the threshold values and click Refresh
Sort according to Distance or IM Value
21 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Problem CellsAdjust thresholds and Analyse again if neededSelect BTSs and Show Chart or Locate on Map
22 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Analyser Chart
The upper-right cells suffer the most interference over the longest distance
23 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Interference Analysis on the Map
24 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
What Can I Do About It?
Tilt down the antenna
Turn the antennaLower the antenna
Change the antenna (pattern)Reduce transmit power
After one or more of these changes new measurements should be performed to get optimum results from the optimisation
25 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Exercise
Analyse one BSC and find the cell that causes interference over the longest distance with the highest C/I probability
Locate the interfering cell and interfered cells on the mapWhat can you do to these cells before/after the frequency allocation?
26 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Summary Workflow
Select Tools->Network Statistics->Interference Matrices
Select BSCs and interference type for measurement retrieval
Retrieve measurement sets from the correct period
A. Specify the number of blind spots and retrieval thresholdB. Define the default values for blind spot interferers
C. Adjust the BSIC reuse distance and reliability scaling
D. Use Antenna bearing and retrieve traffic, if available
Create predictions to complete the measurements
IMPORTANT!Insert priority values for measured and predicted sets for all interference types (CIP, ARP) that were retrieved
Verify interference matrix in table view and on the map
Use Interference Analyser to find out if you have problem cells that cause interference over a long distance
27 © Noki a Si emens N etwor ks Presentation / PLe / 23.8.2010For public use – IPR applies
Document change history
First version for Optimizer 3.0PLe1.023.8.2010
Change commentNameVersionDate