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Rf planning for lte using atoll v1

RF Planning for LTE using Atoll v1

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Rf planning for lte using atoll v1

  1. 1. RF Planning for LTE USING ATOLL
  2. 2. Introduction This document provides step by step guide for RF engineers to use Atoll for LTE network design using NSN parameter settings. It it assumed that these settings will be available in file xxx.mdb. • Create the project in Atoll using NSN parameter settings • Perform coverage prediction studies • Perform Monte Carlo simulation
  3. 3. Create LTE Project in Atoll
  4. 4. Inputs As in any RF tool, the following information is needed to create a project in Atoll. • Geodata • FDD or TDD • Spectrum: frequency band and channel bandwidth • Propagation Model • Site, Cell, Transmitter info • Bearer info • Other LTE Parameters
  5. 5. Open Atoll Tool Event Viewer showing the status of tool execution
  6. 6. Create Project The 1st step is to create a project by importing the default NSN parameter settings. Click File -> New -> From an Existing Database to open the xxx.mdb file with NSN settings
  7. 7. Create Project Click OK on the pop-up window to import the NSN settings in the new project
  8. 8. Import Clutter Data Click File->Import, open the index.txt file for clutter data, select Clutter Classes, click OK.
  9. 9. Import Clutter Data If the clutter data is not shown on the window, click Geo tab -> Clutter Classes -> Clutter -> Centre in the Map Window to display the map.
  10. 10. Import DTM Data Click File->Import, open the index.txt file for DTM data, select Altitudes, click OK.
  11. 11. Import DTM Data Clear the check box for Clutter Classes, the DTM data should be displayed Remember to save the project from time to time
  12. 12. Import Vector Data Click File->Import, select the wanted vector files, select New folder in ‘Geo’ to create a Vector folder if it is not available, ensure the coordinate system is correct, then click Import.
  13. 13. Import Vector Data Clear the check marks for all layers above, the vector data should be displayed
  14. 14. Antenna Patterns Antenna patterns can be imported into Atoll, or manually added. Check the Atoll user guide for details.
  15. 15. Propagation Models Propagation models can be imported into Atoll, or manually added. Check the Atoll user guide for details. Copy&Paste can also be used.
  16. 16. Transmitter Global Parameters The Global Parameters for Transmitters should use the default NSN settings which are imported when the project was created. The Global Parameters can be accessed by clicking Data tab -> Transmitters -> Properties NSN setting may be different from the displayed values
  17. 17. Define Frequency Band Under Data tab, click Transmitters->Network Settings->Frequencies->Band to open the table for band and channel definition. Make sure the required spectrum is defined correctly. If it is not defined, It can be added in the table manually, or imported using the template below. To import, click Actions at bottom and Import
  18. 18. LTE Bearers Under Data tab, click Transmitters->Network Settings->LTE Bearers to open the table for Bearer definition. This definition is applicable to both UL and DL. However, 64QAM is not supported in UL currently. Don’t change this table. It should be imported from xxx.mdb file
  19. 19. Quality Indicators Under Data tab, click Transmitters->Network Settings->Quality Indicators to open the table for Quality Indicators definition. This definition is applicable to both UL and DL. Don’t change this table. It should be imported from xxx.mdb file.
  20. 20. Schedulers Under Data tab, click Transmitters->Network Settings->Schedulers to open the table for Schedulers definition. Note: this scheduler is implemented by Atoll algorithms, which may be different from scheduler algorithms in NSN eNodeB even if they are called the same names. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below.
  21. 21. TMA Under Data tab, click Transmitters->Equipment->TMA Equipment to open the table for TMA definition. All TMAs used in the project should be defined here.
  22. 22. Feeders Under Data tab, click Transmitters->Equipment->Feeder Equipment to open the table for feeder definition. All feeders used in the project should be defined here.
  23. 23. eNodeB Under Data tab, click Transmitters->Equipment->BTS Equipment to open the table for eNodeB definition. All types of eNodeB used in the project should be defined here.
  24. 24. LTE Equipment Under Data tab, click Transmitters->Equipment->LTE Equipment to open the table for LTE Equipment definition. All types of Cell and UE equipment used in the project should be defined here. • The parameters in Cell Equipment are for UL ONLY!!! • The parameters in UE Equipment are for DL ONLY!!! Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below.
  25. 25. Cell Equipment Move the mouse pointer to the left edge of a row, when the pointer changes to an arrow pointing to the right, double click to access the table for the relevant cell equipment. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below. Double click
  26. 26. Cell Equipment – Bearer Selection Thresholds The C/(I+N) table gives the CINR thresholds for MCS selection in the UL link adaptation for a given mobility. Bearers 18 – 29 are not supported in UL currently. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below. Click one of them to access the selection thresholds
  27. 27. Cell Equipment – Quality Graphs The quality graph table gives the block error rates for CINR thresholds in a given MCS for a mobility type. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below. Click one of them to access the selection thresholds
  28. 28. Cell Equipment – MIMO This table specify the diversity gain and MIMO gain (MU-MIMO) in UL for a mobility environment. • Currently MU-MIMO is not supported, hence the MIMO gain is one • The UL diversity gain has been integrated into Bearer Selection Thresholds table, hence the gain is 0 dB. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below. Click one of them to access the selection thresholds Number of UE Tx antenna ports Number of cell Rx antenna ports
  29. 29. UE Equipment - Bearer Selection Thresholds Similarly, double click to access the table for the relevant UE equipment. Again, all parameters for UE Equipment are for DL only. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below.
  30. 30. UE Equipment – Quality Graphs The quality graph table gives the block error rates for CINR thresholds in a given MCS for a mobility environment. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below.
  31. 31. UE Equipment – MIMO This table specify the diversity gain and MIMO gain (SU-MIMO) in DL, depending on the UE operation mode. • The MIMO gain may be dependent on CINR • In case of Tx diversity mode, part of DL diversity gain has been integrated into Bearer Selection Thresholds table, the remains gain is entered in Diversity Gain column. Don’t change this table. It should be imported from xxx.mdb file and might be different from the table below. Number of Cell Tx antenna ports Number of UE Rx antenna ports MIMO capacity gain is 1 in Tx Diversity
  32. 32. Sites Table In Atoll, for each eNodeB a site and transmitters are defined. The site info refers to the physical location of the site, and transmitter info refers to cell configuration including antenna. In Sites table, the site name, longitude and latitude are given. The following is a site template in .csv format. • use this template to enter site information for each market • Make sure the column for Altitude is blank. When the file is imported into Atoll, the site altitude info will be updated automatically based on DTM data. Keep Altitude column blank
  33. 33. Import Sites Table The Sites table can be open in 2 ways • double click the Sites folder in Data tab, or • click Sites -> Open Table Before importing the sites, delete any unwanted sites in the site table. This can be done by selecting the entire rows for the corresponding sites, and then press Delete in the keyboard.
  34. 34. Import Sites Table Move mouse on the Sites table, right click and select Import. Ensure for each column, the title in Source and Destination matches. Click Import button at bottom to import the site table
  35. 35. Import Sites Table To add a site, we can also enter the info directly in the site table on the last row. Note: in Atoll, we can do copy&paste between any Atoll table and excel sheet just like between two excel sheets.
  36. 36. Transmitters Table The following is a Transmitters table template in .csv format. • use this template to enter transmitter information for each market.
  37. 37. Import Transmitters Table The transmitters for a site can be added only after the site info is available in Atoll. The Transmitters table can be open in 2 ways • double click the Transmitter folder in Data tab, or • click Transmitters -> Open Table Before importing the sites, delete any unwanted transmitters in the Transmitter table. Note when a site is deleted, all of the associated transmitters are deleted too. Move mouse on the Transmitters table, right click and select Import to open the Transmitters file.
  38. 38. Import Transmitters Table Ensure for each column, the title in Source and Destination matches. Click Import button at bottom to import the transmitter table
  39. 39. Import Transmitters Table The imported transmitters should be visible. New transmitters can also be added, deleted, or edited manually.
  40. 40. Cells Table The following is a Cells table template in .csv format. • use this template to enter cell information for each market.
  41. 41. Import Cells Table The cells for a site can be added only after the transmitter info is available in Atoll. The Cells table can be opened by clicking Transmitters ->Cells-> Open Table. Move mouse pointer to anywhere on the Cells table, right click and select Import to open the Cells file. Ensure for each column, the title in Source and Destination matches. Click Import button at bottom to import the Cells table
  42. 42. Import Cells Table Clear and check the box for Transmitters to refresh, the transmitter icon becomes solid red after the Cells table is filled for the relevant cell.
  43. 43. Individual Cell Parameters If you double click a transmitter under Data tab->Transmitters folder, all settings can also be accessed and edited.
  44. 44. LTE Parameters The following parameters must be defined for Monte Carlo simulation and some types of coverage predictions. • Services: the types of services and traffic profiles considered for prediction and MC simulation. • Mobility Types: the types of mobility considered for prediction and MC simulation. • Terminals: the types of terminals considered for prediction and MC simulation. • User Profiles: the types of users considered for prediction and MC simulation. • Environments: the types of environments for traffic distribution in MC simulation. Note: each defined environment can be given any name, and it is not relevant to the clutter types of Geo Data.
  45. 45. LTE Parameters - Services Define traffic profile for each service type.
  46. 46. LTE Parameters – Mobility Types Define the mobility environment It may need to define multiple mobility types for same speed. For instance, the SINR thresholds for a given MCS are different for a UE in Tx diversity mode and spatial multiplexing mode. See slide for UE Equipment - Bearer Selection Thresholds.
  47. 47. LTE Parameters - Terminals Multiple terminals can be defined depending on its capability and number of antenna ports, etc.
  48. 48. LTE Parameters – User Profiles Define how a user would use different type services in the busy hour.
  49. 49. LTE Parameters – Environments The environments are purely defined for traffic distribution purpose. It specify the user density for each type of users if the corresponding environment is used to define an area for traffic distribution. The weighting for clutter type and indoor are also specified.
  50. 50. Summary So far, the LTE project for a market should be created. Now it is ready to perform RF analysis and Monte Carlo simulation.
  51. 51. Coverage Predictions
  52. 52. Define Zones Multiple zones can be defined and used for different purposes in prediction and MC simulation • Filtering Zone: The filtering zone is a graphical filter that restricts the objects displayed on the map and on the Data tab of the Explorer window to the objects inside the filtering zone. It also restricts which objects are used in calculations such as coverage predictions, etc. • Computation Zone: The computation zone is used to define which base stations are to be taken into consideration in calculations and the area where Atoll calculates path loss matrices, coverage studies, etc. • Focus Zone and Hot Spot Zones: With the focus zone and hot spot zones, you can select the areas of coverage predictions or other calculations on which you want to generate reports and results. • Printing Zone: The printing zone allows you to define the area to be printed. • Coverage Export Zone: The coverage export zone is used to define part of the coverage prediction to be exported as a bitmap.
  53. 53. Define Zones To define a zone, click the zone->Draw, an draw the polygon on the maps. It can also be imported. The defined zone can be deleted, edited, and exported if desired.
  54. 54. Predictions The following predictions are recommended • Coverage by DL best RS signal level • Coverage by DL best server (based on RS signal level) • Coverage by number of servers • Coverage by DL PDSCH & PDCCH C/(I+N) • Coverage by UL PUSCH & PUCCH C/(I+N) • Coverage by DL Peak RLC Channel Throughput • Coverage by UL Peak RLC Allocated Bandwidth Throughput • Coverage by UL Peak RLC Cell Capacity • Coverage by Best Bearer (DL) • Coverage by Best Bearer (UL) • Coverage by DL PDSCH & PDCCH Signal Level • Coverage by UL PUSCH & PUCCH Signal Level
  55. 55. Create New Prediction To create a new prediction, click Predictions->New, select the desired prediction study and click OK. The new study is added in the Predictions folder. Click the new study-> Calculate, the prediction should be performed. Check the box on the left of the study to show the results.
  56. 56. Coverage by DL Best Signal Level Click Predictions->New->Coverage by Signal Level. Select Best Signal Level in Field of Display tab. Shadowing and indoor coverage can be set
  57. 57. DL Signal Level and RSRP In Atoll, the signal level is the total instantaneous power of RS signal when RS is transmitted. In case the power offset is 0 between RS RE and other RE, this signal level is 7.8 dB (10*log(12/2)) lower than total carrier power. In LTE, RSRP is used, which is defined as the average of power levels received across all Reference Signal symbols within the considered measurement frequency bandwidth. Since in 10Mhz bandwidth there are 100 REs ( 2 RE/FB * 50 FBs) used for RS. Hence, the RSRP is 10*log(100) = 20 dB lower than the signal level. S-Syn P-Syn Ref. DTX S-Syn P-Syn S-Syn P-Syn S-Syn P-Syn DTX Ref. S-Syn P-Syn S-Syn P-Syn S-Syn P-Syn Ref. DTX S-Syn P-Syn S-Syn P-Syn S-Syn P-Syn DTX Ref. S-Syn P-Syn S-Syn P-Syn The signal level is calculated only during RS active time 1 Frequency Block (FB) includes 12 subcarriers 2 Res used for RS per FB during RS active time
  58. 58. Settings Name the prediction study, define the resolution Define display type and field Depending on the prediction, settings on terminal, mobility service, and MC simulation results may be needed.
  59. 59. Settings To customize the display legend, you can work on the window manually, or click Actions->Shading to re-define it automatically.
  60. 60. Statistics Select a prediction, right click and then generate Histogram or report.
  61. 61. Coverage by Best Server (based on RS signal level) Click Predictions->New->Coverage by Transmitter. Margin is changed here
  62. 62. Coverage by Number of Servers (based on RS signal level) Click Predictions->New->Coverage by Transmitter. Since there is no SHO in LTE, the areas with 3 or more servers may subject to strong interference. LTE does not support SHO, any locations with 3 or more servers indicates potential interferences
  63. 63. Coverage by DL PDSCH & PDCCH C/(I+N)
  64. 64. Coverage by UL PUSCH & PUCCH C/(I+N) Atoll practices power control such that the max SINR is equal to the required SINR for highest MCS plus a margin.
  65. 65. Reference Signal C/(I+N) and RSRQ In Atoll, the coverage by RS C/(I+N) can also be calculated. If the power offset between RS and PDSCH is 0 dB, it is found that the RS C/(I+N) is always 3 dB lower than the PDSCH C/(I+N) since there is no Tx diversity for RS. In LTE, RSRQ = N*RSRP/RSSI, where N is the number of FBs. Since the RS CINR is calculated only on symbol duration when RS is active, we have RS CINR = RSRP/(I+N of one subcarrier) = RSRP/RSSI*(N*12). By comparing these 2 formulas, we have RSRQ = RS CINR/12 = RS CINR (dB) – 10.8 dB.
  66. 66. Coverage by DL Peak RLC Channel Throughput
  67. 67. Coverage by UL Peak RLC Allocated Bandwidth Throughput Note: the allocated bandwidth throughput is the max throughput for a UE in UL if there is sufficient frequency blocks. Due to the limited power at UE, one UE does not use all UL RBs typically. Hence, the allocated BW throughput is different from the cell capacity.
  68. 68. Share Prediction Studies in Projects It might be necessary to run same coverage prediction studies (such as RS signal level, CINR) and use the same settings (such as required cell edge probability, service for the prediction, legend) for different markets. In this case, the predictions can be shared so save time and maintain the consistence cross markets. The following is an example list of pre-defined coverage prediction studies (*.cfg) for Tx diversity and EPA05 mobility. We show how to import this list into a project in next page.
  69. 69. Import Prediction Studies into Project Click Tools->User Configuration->Import and select the *.cfg file (in previous page for instance). Enable the 1st check box if you want to remove all of the existing predictions. Click OK and the list is imported.
  70. 70. Run Imported Predictions The imported predictions are empty and locked. To run the predictions, we have 2 options • Click each prediction ->Calculate to run individual prediction • Click Predictions->Unlock Studies to unlock all predictions, and then click Predictions- >Calculate to run all predictions A key indicates a prediction is locked
  71. 71. Monte Carlo Simulation
  72. 72. Define Traffic Maps MC simulation needs traffic maps. The following types of traffic maps can be used in Atoll. • Traffic maps per sector. It can be used if you have live traffic data from the OMC (Operation and Maintenance Centre). The OMC collects data from all cells in a network. This includes, for example, the number of users or the throughput in each cell and the traffic characteristics related to different services. Traffic is spread over the best server coverage area of each transmitter and each coverage area is assigned either the throughputs in the uplink and in the downlink or the number of users per activity status. • Traffic map per user profile. This can be used if you have marketing-based traffic data. Traffic maps per density of user profiles, where each vector (polygon, line or point) describes subscriber densities (or numbers of subscribers for points) with user profiles and mobility types, and traffic maps per environment of user profiles, where each pixel has an assigned environment class. • Traffic maps per density (number of users per km2). This can be used if you have population-based traffic data, or 2G network statistics. Each pixel has an actual user density assigned.
  73. 73. Create Traffic Maps Per Density Here a traffic map is created using the method for Traffic maps per density. This traffic map will be used in the following MC simulation example. Check the Atoll LTE User Manual for how to create different types of traffic maps. Define an environment for traffic called Type 1 in Geo->LTE Parameters->Environments Double click Type 1 to open the table for its properties User type density Weighting on clutter type and indoor Business User Profile defined in LTE Parameters
  74. 74. Create Traffic Maps Per Density In Geo tab, click Traffic->New Map, and choose based on environments of user profiles, click Create button. In the new window, select Type 1, press the button for Polygon, and then draw a polygon for the map areas where the traffic needs to be distributed.
  75. 75. Perform MC Simulations Multiple simulations can be defined at one time. Click Data tab->LTE Simulations->New, in the pop-up window • General tab • Specify a name for the simulation studies • Specify the number of simulations. Multiple simulations result in better statitics. • Specify the max allowed UL and DL traffic load constraints in cell level
  76. 76. Perform MC Simulations • Source Traffic tab • Global Scaling Factor is used to scale the traffic based on the selected traffic map • Select the desired traffic map for simulation • Advanced tab • Specify the requirements for simulation convergence and the seed for random number generation. Click OK in any tab to start simultion
  77. 77. Individual Simulation Results In this example, mobiles in various status in Simulation 4 are displayed
  78. 78. Individual Simulation Results Double click Simulation 4 to access the simulation results. • Statistics tab: statistics of the simulation results • Sites tab: simulation results on eNodeB level • Cells tab: simulation results on cell level • Mobiles tab: simulation results for each active mobile • Initial Conditions tab: summary of the simulation conditions
  79. 79. Average Simulation Results To access the average simulation results of all simulation under one group, click the Group Name->Average Simulation Double click Simulation 4 to access the simulation results. In this case, the Mobiles tab is not available
  80. 80. Simulation Results on Cell Level The cell level simulation results may be most interesting in both individual simulation or group of simulation. The information such as cell UL and DL load, UL noise rise, throughput per service or cell capacity on different layers can be found in this table. Note: the average cell results render better statistics than individual simulation.
  81. 81. Use Simulation Results for Prediction In coverage prediction studies, many needs assumption about DL traffic load and UL noise rise. The assumption can be given in the Cells table discussed earlier. However, how do we know if the assumption makes sense for a given traffic profile? By selecting the Load Conditions for a prediction, we can use either the assumption from Cells table, or the desired simulation results as the DL load and UL noise rise for prediction Cells table Simulation results
  82. 82. Update Cells Table Using Simulation Results Likewise, if we want to update the Cells Table by simulation results, click Commit Results button at the bottom.
  83. 83. Atoll ACP
  84. 84. Atoll ACP The ACP (automatic cell planning) module has been integrated into Atoll. There is no need to perform import and export between RF planning tool and the ACP module. However, a separated license for ACP is required. ACP enables network reconfiguration through two mechanisms: • Parameter reconfiguration: ACP enables the reconfiguration of different network parameters to improve network quality, such as the antenna model, the azimuth and tilt of the antenna, the antenna height, the Tx power, RRM parameters, etc. • Site selection capabilities: ACP can perform site and sector selection. Two main methods are supported: • Selecting which sites and/or sectors to suppress among existing sites in the network. • Selecting which sites to use among many candidates sites. Groups of candidate sites can also be defined, which provides the possibility of selecting a minimum and maximum number of sites to add within each group By minimizing the global cost function, the ACP tries to optimize the network.
  85. 85. Launch ACP Click ACP – Automatic Cell Planning->New to launch the ACP setup window, where all constraints and conditions can be configured.
  86. 86. ACP Optimization Results After the ACP optimization, the results can be accessed. Summary of improvement The suggested changes are ranked based on improvement Improvement up to the number of changes
  87. 87. ACP Optimization Results Showing coverage on maps for before and after ACP optimization.
  88. 88. MIMO Handling in Atoll
  89. 89. MIMO Modes in Atoll Atoll supports 3 MIMO modes in DL • Transmit diversity • Spatial multiplexing • AMS (automatic mode switch): a threshold is set for AMS. If the calculated SISO CINR (before TxDiv gain is applied) is lower than the threshold, the UE is in TxDiv mode, otherwise in SM mode.
  90. 90. C/(I+N) Calculation in Atoll In Atoll, the CINR at each pixel is calculated based on SISO (1 BTS Tx antenna and 1 UE Rx antenna). When more than 1 Tx and/or Rx antenna are used, if UE is in TxDiv mode, the corresponding diversity gain is added on the calculated CINR. If UE is in SM mode, then there is no diversity gain for CINR. Instead, the capacity gain will be considered due to 2 code streams. • In Atoll, the Max Power per cell is corresponding to one Tx antenna port. That is, if it is 30W (44.8 dBm), then the power is 30W+30W in case of 2 Tx antennas. • Hence, for SM, the calculated CINR based on SISO could be 3 dB higher than the real one since the interference will be doubled when 2 Tx antennas are used in all neighbor cells. • In case of TxDiv, both the interference and Tx power will be doubled. However, since the signal is combined coherently and the interference is not, we still should see about 3 dB gain.
  91. 91. AMS Not Working Directly for NSN Parameters Though AMR is supported in Atoll, it does not work correctly at Atoll 2.8.0 because • The AMS threshold at 2.8.0 is based on RS C/N, not PDSCH C/(I+N) • 2 independent slow fading and standard deviations are used for RS CNR and PDSCH CINR calculation. We saw examples that a bearer is switched to SM at very low PDSCH CINR since the RS CNR happened to be higher than the threshold. Even if Atoll fix the problem in next release, the AMS function cannot be used due to the special MCS vs SINR tables obtained in NSN link level simulation. • In case of TxDiv, the diversity gain has been built into the table • for a given UE, only 1 table can be used in Atoll. Hence, AMS is possible only if we can find a way to combine the 2 tables • if the SINR difference for each MCS is fixed, then it is possible to use the table for SM and put the difference as part of the diversity gain. Unfortunately, this is not true. • Two work around methods will be presented later. EPA05, SM EPA05, TxDiv MCS SINR MCS SINR 1 -0.09 1 -6.09 2 1.41 2 -4.92 3 2.29 3 -4.29 4 3.63 4 -3.15 5 4.78 5 -2.46 6 5.74 6 -1.6 7 7.64 7 -0.63 8 8.9 8 0.44 9 9.75 9 1.33 10 11.51 10 2.16 11 11.71 11 2.38 12 12.55 12 3.11 13 13.79 13 4.09 14 14.92 14 4.97 15 16.18 15 6.06 16 17.42 16 7.12 17 17.95 17 7.46 18 18.61 18 8.26 19 19.22 19 8.69 20 20.55 20 9.86 21 21.52 21 10.69 22 22.63 22 11.58 23 23.5 23 12.5 24 24.82 24 13.47 25 25.97 25 14.68 26 27.61 26 15.79 27 27.86 27 16.42 28 28.97 28 17.17 29 30.78 29 18.64
  92. 92. Determine Best AMS Threshold The AMS threshold should be recommended by global team. Here the best threshold is derived based on the 2 MCS vs SINR tables for TxDiv and SM. • For a given SINR, we can use SM to send 2 data streams on a lower MCS, or use TxDiv to improve the SINR such that a higher MCS can be used for one data stream. • The best threshold should be corresponding to the point below which TxDiv results in higher and above which SM has higher throughput • In case of EPA05, it is found that the threshold is 22.63 dB (based on the default MIMO gain table in Atoll). EPA05, SM EPA05, TxDiv 3 dB gain for SINR MCS SINR CodeRate MCS SINR If this MCS for SM Then this SINR for TxDiv Then This MCS for TxDiv Corresponding TxDiv CodeRate Corresponding SM CodeRate SM/TxDiv throughput ratio 1 -0.09 0.21 1 -6.09 1 2.91 11 1.20 0.24 0.20 2 1.41 0.27 2 -4.92 2 4.41 13 1.55 0.33 0.21 3 2.29 0.33 3 -4.29 3 5.29 14 1.76 0.41 0.23 4 3.63 0.44 4 -3.15 4 6.63 15 2.00 0.55 0.28 5 4.78 0.54 5 -2.46 5 7.78 17 2.33 0.70 0.30 6 5.74 0.66 6 -1.6 6 8.74 19 2.50 0.88 0.35 7 7.64 0.79 7 -0.63 7 10.64 20 2.83 1.10 0.39 8 8.9 0.95 8 0.44 8 11.9 22 3.32 1.37 0.41 9 9.75 1.08 9 1.33 9 12.75 23 3.57 1.58 0.44 10 11.51 1.20 10 2.16 10 14.51 24 3.86 1.83 0.47 11 11.71 1.20 11 2.38 11 14.71 25 4.16 1.83 0.44 12 12.55 1.35 12 3.11 12 15.55 25 4.16 2.08 0.50 13 13.79 1.55 13 4.09 13 16.79 27 4.65 2.44 0.52 14 14.92 1.76 14 4.97 14 17.92 28 4.82 2.81 0.58 15 16.18 2.00 15 6.06 15 19.18 29 5.64 3.29 0.58 16 17.42 2.25 16 7.12 16 20.42 29 5.64 3.73 0.66 17 17.95 2.33 17 7.46 17 20.95 29 5.64 3.87 0.69 18 18.61 2.33 18 8.26 18 21.61 29 5.64 3.91 0.69 19 19.22 2.50 19 8.69 19 22.22 29 5.64 4.22 0.75 20 20.55 2.83 20 9.86 20 23.55 29 5.64 4.82 0.85 21 21.52 3.08 21 10.69 21 24.52 29 5.64 5.28 0.94 22 22.63 3.32 22 11.58 22 25.63 29 5.64 5.75 1.02 23 23.5 3.57 23 12.5 23 26.5 29 5.64 6.22 1.10 24 24.82 3.86 24 13.47 24 27.82 29 5.64 6.76 1.20 25 25.97 4.16 25 14.68 25 28.97 29 5.64 7.32 1.30 26 27.61 4.49 26 15.79 26 30.61 29 5.64 7.98 1.41 27 27.86 4.65 27 16.42 27 30.86 29 5.64 8.27 1.47 28 28.97 4.82 28 17.17 28 31.97 29 5.64 8.60 1.52 29 30.78 5.64 29 18.64 29 33.78 29 5.64 10.16 1.80 C/(I+N) (dB) Max SU- MIMO Gain 10 1.49444 11 1.52313 12 1.54998 13 1.57497 14 1.59813 15 1.61954 16 1.63928 17 1.65747 18 1.67423 19 1.68966 20 1.70389 21 1.71701 22 1.72914 23 1.74036 24 1.75075 25 1.7604 26 1.76937 27 1.77773 28 1.78552 29 1.79281 30 1.79963 31 1.80603 32 1.81204 33 1.8177 34 1.82303 35 1.82807
  93. 93. Determine Best AMS Threshold Another way is to draw the code efficiency (bits/symbol) vs SINR curves for SM and TxDiv (diversity gain should be applied in the SINR). The best threshold is the cross point of the 2 curves, which is 22.63 dB. Code Efficiency 0 2 4 6 8 10 12 -10 0 10 20 30 40 SINR (dB) Bits/Symbol SM TxDiv C/(I+N) (dB) Max SU- MIMO Gain 10 1.49444 11 1.52313 12 1.54998 13 1.57497 14 1.59813 15 1.61954 16 1.63928 17 1.65747 18 1.67423 19 1.68966 20 1.70389 21 1.71701 22 1.72914 23 1.74036 24 1.75075 25 1.7604 26 1.76937 27 1.77773 28 1.78552 29 1.79281 30 1.79963 31 1.80603 32 1.81204 33 1.8177 34 1.82303 35 1.82807
  94. 94. AMS Work Around To use AMS, we need combine the 2 MCS vs SINR tables for SM and TxDiv into one. Simply combining 2 tables based on the AMS threshold does not work. In the following, we show 2 methods for AMS work around by examples. • Method 1: work around in TxDiv mode. This method works fine if the MIMO gain is independent of the mobility. • Method 2: work around in SM mode. This method always works. However, more MCS bearers need to be defined. Though the best AMS threshold is found to be 22.63 dB for EPA05, we use different thresholds in the examples for Method 1 and 2. Note the best AMS threshold is based on radio channel or mobility environment. For instance, the best AMS threshold for ETU70 is 21.59 dB. • For prediction studies, each study involves a UE for a single mobility, hence we can always use the best AMS threshold • For MC simulation, each simulation may include UEs in different mobility environments. However, only one threshold is defined in each cell. In this case, it is better to use the minimum of the best AMS thresholds for all mobility environments.
  95. 95. AMS Work Around 1 The method 1 is presented using an example with AMS threshold 21.52 dB. The MCS vs SINR table for AMS is created based on the 2 tables as follows • Keep the tables for TxDiv. • Add new MCS 30 – 38, which correspond to SM MCS 21 – 29, respectively. • For each new MCS (say MCS 30), the required SINR is equal to the required SINR for corresponding SM MCS (say SM MCS 21) plus 3 dB, in order to cancel the 3 dB diversity gain which is not available to SM MCSs. Now, the table is combined. When SINR is lower than the threshold, UE is operating in normal TxDiv mode (using MCS 1-29). However, if the threshold is exceeded, one of the MCS 30 – 38 will be assigned to UE (in SM). EPA05, SM EPA05, TxDiv MCS SINR MCS SINR 1 -0.09 1 -6.09 2 1.41 2 -4.92 3 2.29 3 -4.29 4 3.63 4 -3.15 5 4.78 5 -2.46 6 5.74 6 -1.6 7 7.64 7 -0.63 8 8.9 8 0.44 9 9.75 9 1.33 10 11.51 10 2.16 11 11.71 11 2.38 12 12.55 12 3.11 13 13.79 13 4.09 14 14.92 14 4.97 15 16.18 15 6.06 16 17.42 16 7.12 17 17.95 17 7.46 18 18.61 18 8.26 19 19.22 19 8.69 20 20.55 20 9.86 21 21.52 21 10.69 22 22.63 22 11.58 23 23.5 23 12.5 24 24.82 24 13.47 25 25.97 25 14.68 26 27.61 26 15.79 27 27.86 27 16.42 28 28.97 28 17.17 29 30.78 29 18.64 30 24.52 31 25.63 32 26.5 33 27.82 34 28.97 35 30.61 36 30.86 37 31.97 38 33.78 +3 dB TxDivSM
  96. 96. AMS Work Around 1 Since MCS 30 – 38 are for SM, the corresponding bits/symbol needs to be defined in LTE Bearers. We use MIMO SM gain 1.84 as an example. Since MCS 30 is corresponding to SM MCS 21. bits/symbol = 3.077 (for MCS 21) Bits/symbol = 3.077*1.84 = 5.66 (for MCS 30) In reality, the MIMO gain varies with the SINR. Hence, different MIMO gain needs to be used for different MCS bearers. Obviously, this can be done easily. Note the MIMO gain for a MCS is different in different mobilities since the required SINR is different. If the MIMO gain difference is ignorable, Method 1 works fine. Otherwise, we have to use Method 2.
  97. 97. AMS Work Around 1 Update the Bearer Selection Thresholds table
  98. 98. AMS Work Around 1 Update the Quality Graphs table and MIMO table For consistence, 3 dB is given
  99. 99. AMS Work Around 1 Finally, update the Highest Bearer to 38 for each desired service. • If you want to simulate Tx Diversity only, set this to 29, and MCS 30 – 38 will not be available. • If you want to simulate AMS, set this to 38, and all MCSs will be available. Don’t forget to make sure that the cell is set as TxDiv mode.
  100. 100. EPA05, AMS MCS SINR 1 -9.09 2 -7.92 3 -7.29 4 -6.15 5 -5.46 6 -4.6 7 -3.63 8 -2.56 9 -1.67 10 -0.84 11 -0.62 12 0.11 13 1.09 14 1.97 15 3.06 16 4.12 17 4.46 18 5.26 19 5.69 20 6.86 21 7.69 22 8.58 23 9.5 24 10.47 25 11.68 26 12.79 27 13.42 28 14.17 29 15.64 32 22.63 33 23.5 34 24.82 35 25.97 36 27.61 37 27.86 38 28.97 39 30.78 AMS Work Around 2 The method 2 is presented using an example with AMS threshold 22.63 dB. The MCS vs SINR table for AMS is created based on the 2 tables as follows • For MCS 1 – 29, using the tables for TxDiv but put all diversity gain into SINR table. • Add new MCS 30 – 38, which correspond to SM MCS 21 – 29, respectively. Now, the table is combined. Cell is set to SM mode. When SINR is higher than the threshold, UE is operating in normal SM mode (using MCS 32 – 39). However, if the threshold is lower, one of the MCS 1 – 29 will be assigned to UE (in TxDiv). -3 dB TxDivSM EPA05, TxDiv MCS SINR 1 -6.09 2 -4.92 3 -4.29 4 -3.15 5 -2.46 6 -1.6 7 -0.63 8 0.44 9 1.33 10 2.16 11 2.38 12 3.11 13 4.09 14 4.97 15 6.06 16 7.12 17 7.46 18 8.26 19 8.69 20 9.86 21 10.69 22 11.58 23 12.5 24 13.47 25 14.68 26 15.79 27 16.42 28 17.17 29 18.64 EPA05, SM MCS SINR 1 -0.09 2 1.41 3 2.29 4 3.63 5 4.78 6 5.74 7 7.64 8 8.9 9 9.75 10 11.51 11 11.71 12 12.55 13 13.79 14 14.92 15 16.18 16 17.42 17 17.95 18 18.61 19 19.22 20 20.55 21 21.52 22 22.63 23 23.5 24 24.82 25 25.97 26 27.61 27 27.86 28 28.97 29 30.78
  101. 101. AMS Work Around 2 The bearer efficiency for MCS 32 – 39 is same as that for MCS 22 – 29, respectively. However, we define no MIMO gain for MCS 1 – 29 (TxDiv), and normal MIMO gain is applied to MCS 32 – 39 (SM). Method 2 can work with any MIMO gain table.
  102. 102. AMS Work Around 2 Define a new mobility type for AMS (called MIMO_AMS_EPA05 here). Use the combined MCS vs SINR table for Bearer Selection threshold definition.
  103. 103. AMS Work Around 2 Update the Quality Graphs table and MIMO table accordingly. • MCS 1 – 29, 0 for MIMO gain, 0 for Diversity gain (diversity gain included in SINR table) • MCS 32 – 39, MIMO gain based on SINR, 0 dB diversity gain.
  104. 104. AMS Work Around 2 Finally, update the Highest Bearer to 39 for each desired service. • If the highest bearer is set this to 29, MCS 32 – 39 will not be available. That is, we can use this as a work around for Tx Diversity • If we want to simulate AMS, set this to 39, and all MCSs will be available. Don’t forget to make sure that the cell is set to SM mode!
  105. 105. AMS Work Around 2 In concept, Method 2 also works well if cell is set to AMS mode and the AMS threshold is set to any value lower than the target threshold (22.63 dB in the example) if the AMS function works properly. This is because even if cell is switched to AMS for a bearer in MCS 1-29, the bearer is actually still in TxDiv due to the work around. However, setting cell in AMS should not be performed since • if the AMS threshold is set to a value higher than the threshold by mistake, the results would be incorrect • A bug is found in current version of Atoll 2.8.0. When cells are set to AMS mode in Monte Carlo simulation, it is found that MCS bearers cannot be selected correctly since: • According to Forsk, the AMS threshold is not based on PDSCH CINR, but on Reference Signal CNR • There are slow fading standard deviations used separately for PDSCH CINR and RS CNR calculation. Consequently, we saw bearers with high CINR in TxDiv mode and that with low CINR in SM mode due to the relevant RS CNR. Fortunately we need a work around method for AMS from beginning. Hence, the AMS issue in Atoll has no impact on us!
  106. 106. Comparison - AMS and TxDiv: DL Peak RLC Channel Throughput TxDiv AMS
  107. 107. Comparison - AMS and TxDiv: DL Best Bearer TxDiv AMS
  108. 108. Physical Cell ID Planning Physical cell ID can be allocated manually or automatically. To perform automatic physical cell ID planning, click Transmitters->Cells->Physical Cell IDs->Automatic Allocation.
  109. 109. Appendix
  110. 110. Existing Issues The following issues are identified in Atoll v2.8.0 Build 2912. • C/(I+N) calculation • Setting C/I Standard Deviation in the table for Clutter Class Properties: to saving computation time, the shadowing is not applied to each interference. Instead, in CINR calculation, Atoll calculate CINR firstly without considering any shadowing, and then apply a shadowing based on C/I standard deviation to the calculated CINR. In UMTS, according to Forsk, C/I standard deviation is typically 3 dB lower than the model standard deviation. In LTE, Forsk recommends to use the same for model and C/I standard deviation, but this recommendation is not verified by simulation or other analysis.
  111. 111. NSN Link Budget and Dimensioning Tool Many parameters for Atoll settings can be found in the file below: Where the SINR thresholds for MCS are from the NSN Dim tool below. Check https://sharenet-ims.inside.nokiasiemensnetworks.com/Open/380069775 for latest version.
  112. 112. LTE Project Template The following is the xxx.mdb files with NSN parameter settings for Atoll, where v1.0 and v2.0 use method 1 and 2 for AMS work around, respectively. The pre-defined prediction studies for Tx diversity and EPA05 are also given. Another way to create a project with NSN parameter settings is open an existing project with the correct settings (possibly for different market), and then remove the unwanted geo data, sites, coverage predictions and Monte Carlo simulation results, etc in the existing project, and save it as a new project. Then the same procedures discussed in this document can be used to create the project for the new market. In the attached zip file below, the file v1.0 and v2.0 use method 1 and 2 for AMS work around, respectively. Comparing with xxx.mdb, the xxx.ATL not only keep all the parameter settings, but also the pre-defined coverage predictions and Monte Carlo simulations. NSN parameters and Prediction list may be updated!!! Try to get the latest one before creating the project.
  113. 113. References 1. Atoll_2.8.0_User_Manual_Radio_E3.pdf: the user guide for using Atoll for LTE design. 2. Atoll_2.8.0_Technical_Reference_Guide_E3.pdf: provide the formulas used in Atoll for calculation and explains how Atoll works. 3. ATOLL_acp-technical-notes.pdf: manual for ACP module in Atoll 4. Atoll_LTE_Planning_Guide.doc: a NSN document about using Atoll for LTE. 5. LTE Coverage planning with Atoll. https://sharenet- ims.inside.nokiasiemensnetworks.com/Download/408254821 6. 09_-_LTE_Planning_Tool-ATOLL.ppt, https://sharenet- ims.inside.nokiasiemensnetworks.com/Download/406923098

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