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reinerh

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Everything posted by reinerh

  1. When defining a network planning project in ProMan with the attached wst files for 802.11n 20 MHz bandwidth there is a datarate of 58.5 MBit/s for the 64QAM High transmission mode. This is for a single MIMO stream according to IEEE specs (see the figure below). This means when using four MIMO streams in parallel the max. datarate is 260 MBit/s. IEEE 802.11n.wst IEEE 802.11n 5GHz.wst
  2. The optimization of the radio network i.e. selection of the required subset from the set of predefined transmitters to fulfill some coverage targets (e.g. Rx power level) is possible in the OptMan tool. Please see the attached application note. For the implementtation of your own optimization algorithm you would need to call the WinProp API (which is included in the 2018 installer together with the WinProp API manual and some sample projects under MS Visual Studio) for running the coverage prediction for each transmitter. Then you can process the computed results (given in the API data structures) based on your own optimization algorithm. OptManIndoorSubset.pdf
  3. WinProp considers for the area wide radio network planning every pixel in the simulation area as potential user location. Finally all the users in a cell need to share the available resources and impact also the interference on the neighboring cells. For this purpose the cell load for each cell can be defined individually (which is correlated to the number of users in the cell). The cell load can be also derived in the ProMan GUI version based on the generation of individual users over the area (with traffic density and assigned service) using a Monte Carlo simulator. However this functionality is only available in the GUI version and not yet in the WinProp API.
  4. So far WinProp can do only linear polarizations. Therefore you better process the theta and phi components in WinProp and combine the results afterwards outside WinProp.Alternative is to process the WinProp .str file include the ray path data (also the transmission matrix) e.g. using a script outside of WinProp. The syntax of the .str file is described in the ProMan user manual if you serach for str and includes also the transmission matrix T_vv, T_vh, T_hv, and T_hh.
  5. CST can export the antenna pattern in the WinProp ASCII .apa format.
  6. By default WinProp ProMan computes the results area-wide, thus analyzing what would happen if the mobile station is located at any position of the simulation area.
  7. You can define two Tx antennas in ProMan and assign then the same frequency carrier and signal group ID. In this case the two Tx antennas will transmit the same signal and their power contributions will be added at the receiver without interference. For the repeater you can derive the Tx power from the Rx power map of the feeding Tx antenna at the corresponding location. But there is no automatic feature in ProMan to connect one Tx antenna to another Tx antenna using a wireless backhaul link.
  8. Yes, this is possible in WinProp using the ProMan tool. ProMan allows to define multiple Tx antennas in a network planning project based on the selection of an wireless air interface definition (wst file) at the project definition. After the wave propagation simulation for the individual Tx antennas using RunPro, in the network planning simulation using RunNet the best server assignment is done, so you will clearly see which area is covered by which transmitter. Typically the results are computed area wide, representing the "what if" situation if there would be a user placed at any location in the defined simulation area. Please see the ProMan user manual under ProMan => Working with Projects (network planning) for further details.
  9. In the ProMan 2018.0.1 update the observed problem has been solved, now in ProMan the time-variant result for t=0s and the stationary result are identical.
  10. Hi Balaji, there is also a point mode in the ProMan GUI version which can be used to check the computation time for computing a few points. However for some of the WinProp propagation models the computation is done always for the full area, which is due to the specific implementation in order to achieve short computation times for generating the heat maps. So the IRT ray tracing model (based on preprocessing) and the DPM dominant path model are always computing area-wide. The SRT standard ray tracing model computes each point individually, so here the computation time is affected by the number of points which are computed (linear increase with the number). So you can derive the computation time for a single point also by the computation time for the area divided by the number of computed points (can be checked under the info button). The computation time depends also on the number of objects (e.g. building walls) included in the scenario and how many reflections and diffractions shall be computed (especially the diffractions are time-consuming as leading to ray multiplication). But for 1-2 reflections and a limited number of objects the computation time might approach real-time. Best regards Reiner
  11. Hi Balaji, yes, you just need to save the intermediate results (e.g. superposing 4 Tx antennas) as a separate *.fpp file. Then you can subtract the two files (e.g. including 4 Tx antennas each) in the usual way by loading the first *.fpp file and subtracting the second *.fpp file via Edit => Subtract File (Value, File, linear). Best regards
  12. Hi Balaji, the superposition of the individual coverage results can be done in a network planning project by RunNet based on the corresponding air interface (wireless standard definition file *.wst). For this purpose you need to define a network planning project in ProMan, select the air interface definition file (wst file which we provide for the most air interfaces). Then the simulation has two steps: RunPRO is computing the individual coverage for each defined Tx antenna, based on the assigned frequency carrier RunNET superposes the individual results to compute the overall received power, SNIR situation etc. The results of interest can be activated under the Network tab of the ProMan project parameters. Best regards
  13. Typically in a time-variant scenario there are some moving objects, otherwise you can use a stationary scenario. In case of moving objects the results will change depending on the position of the moving objects (for each of the simulated time steps). In WallMan you save a definable shapshot of a time-variant database as stationary *.idb file: Then you can use this stationary database for comparison. Or you just define the start and end time of the simulation parameters to 0s in your ProMan project under the Simulation tab. In this case only the result at t = 0s will be computed. Generally you can compare the results (e.g. Rx power given in *.fpp files) in ProMan via loading one result (either via the result tree in the loaded project or via "File => Open Result" and then subtract the other result via Edit => Subtract Data => Value (File, linear). In case of subtracting a stationary result from a time-variant result you will get the following dialogue, but after confirming with Yes the difference will be displayed: Which propagation model do you use (DPM, SRT, IRT)? Based on this we can investigate further.
  14. Hi, in WinProp you can simulate the channel characteristics including an arbitrary antenna pattern, also at mm waves. However the beam steering is not simulated, i.e. you would need to create the "typical" antenna patterns resulting from the beam steering outside WinProp and then use them in WinProp for simulating the channel characteristics.
  15. Under Edit Project Parameter --> Propagation tab, ProMan offers the possibility to write the data corresponding to the calculated propagation paths into an ASCII file. This file will have extension .str. This optional output (ASCII version) is required for the evaluation of the radio channel characteristics. Besides this, the ray data contained in these files can be used to do further post-processing with other tools, e.g. calculation of angles of arrival/departure, etc. There are different output alternatives within this ray data file, depending on the selected propagation model, the computation mode, the environment under investigation and the enabled outputs on the propagation page. The ASCII ray file written by ProMan contains a header section with general information about the evaluated scenario, such as lower left corner, resolution of the prediction area and the specified parameters of the transmitter. After the header section the data section with the ray information for each predicted pixel starts. Coordinates of predicted pixels are indicated with the keyword POINT. Subsequent the ray data belonging to this pixel follows indicated with the keyword PATH for each available propagation path. In any case for each path the delay (in ns), fieldstrength (in dBµV/m), and list of interaction points is included (based on which AoD and AoA can be computed). Further details are given in the ProMan manual if you search for str file.
  16. In order to compute in ProMan the results on all the floors (with defined relative height above each floor level) you need in WallMan also to define the floor heights (under Edit => Floors), e.g. for a building database with 5 floors, and then save the *.idb file in WallMan:
  17. The direct comparison of time-variant and non-time-variant simulation results is not possible in ProMan, but as workaround you can export the results to ASCII files via File => Export => Export Data (Area) => Export ASCII (All) and then compare using a text editor. As already mentioned for the same object geometries the time-variant and non-time-variant results will be identical.
  18. HI, the logfile output in ProMan can be activated under Settings => Global Settings => Computation tab. The information includes start and end time, but no information about the used RAM. The memory requirement depends typically on the size of the used scenario database (idb/idi/odb(oib/tdb). Especially in case of using preprocessed IRT databases (idi/oib) for indoor/urban scenarios the memory usage can get quite high. Here it is recommended to provide RAM size with more than factor 2 compared to the idi/oib file size. Otherwise the computation times will get very long because of swapping.
  19. With "Combine Data - Max Value " just the max. value for each pixel (from the two results) is used in the final result.
  20. The ray paths computed in ProMan (with the ray tracing models or the dominant path model) can be exported by activating the propagation path output under the Propagation tab. Then the rays are written to a file with suffix *.str. The syntax of this ASCII *.str file is described in the ProMan user manual (if you search for ’str file’), please see the figure below. In ProMan it is also possible to display the computed rays together with the results (e.g. Rx power or pathloss). For this purpose you can use the ray buttons on the upper part of the tool bar on the right.
  21. The WinProp time-variant module allows to assign a trajectory and speed profile to specific object groups (e.g. car on a street). Please have a look in the corresponding chapter 3.8.10 of the WallMan user manual and corresponding sample project under Altair Connect. Then in ProMan the transmitter can be assigned to such a moving object group and the several snapshots of the time-variant scenario with the moving transmitter can be computed, based on the definition of start time, end time, and time increment.
  22. There are two ways to compute the total power of all antennas. Either by defining a network planning project in ProMan using an air interface definition (wst) file. Then by using RunNet the propagation results for the individual antennas will be superposed and the total coverage and interference situation is computed. Alternatively you can load the first result (*.fpp file) in ProMan and combine the results for the further Tx antennas via Edit => Combine Data => Max Value.or via Edit => Add Data => delog (incoherent).
  23. Hello, In case of the direct ray (where the material properties do not matter) also the four different cases Tvv, Tvh, Thv, Thh are analyzed. So what happens in case of Tx antenna with v-pol and Rx antenna with v-pol, and so on for the other cases. As for the direct ray no interactions (like e.g. reflections) are included just the direct ray is analyzed and then Tvv as well as Thh describe the corresponding complex transmission factor in linear scale (depending on the distance) while Tvh as well as Thv are almost zero due to the polarisation mismatch. The first letter stands for the Tx polarization and the second letter for the Rx polarization, so Tvh is for vertically polarized transmission with horizontally polarized reception and Thv evaluates the case for Tx H pol with Rx V pol. The individual transmission matrix components (linear factors) indicate how of the radiated signal is received by the receiver (including the Tx and Rx polarizations). Best regards
  24. The computation of the radio coverage in WinProp can be done in a first step for each RF system (typically each RF system uses its own frequency band). Based on assumptions how much power will be radiated from the Tx antennas into the other frequency bands (and how the reception of the other frequency bands will be attenuated on the receiving end) in terms of an adjacent channel leakage ratio (ACLR) it is then possible to post-process these radio coverage plots for the individual RF systems to determine the interference situation. In a WinProp network planning project (e.g. for LTE or WLAN) generally only the co-channel interference is computed, while the adjacent channel interference is neglected. This means for the determination of the interference on a specific frequency band (RF system) a project with the Tx antennas for all the considered RF systems can be defined and then the Tx power for the Tx antennas of the other RF systems can be reduced by the above mentioned ACLR (which needs to be derived outside of WinProp).
  25. Hello Publi, independent from the observed behaviour when using the two-path model for low tx antenna heights (there might be some limitation due to the grazing incidence causing lower attenuation rates than 40 dB per decade in distance) I am wondering why you are using the two-path model for the mentioned scenario of a parking garage. Because in such a scenario you will always have more than two paths (i.e. besides the direct ray, ground reflection also ceiling reflection, reflections at the vertical walls, ...). Therefore in such an indoor scenario the propagation exponents are typically not above 20 dB per decade and in some cases (e.g. in tunnels) even lower. On the other hand I am wondering why you measured 40 dB attenuation in such an environment.
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