I recently had a bunch of antennas profiles in .msi format, which is the Planet format for storing antenna radiation patterns, but I’m working in Forsk Atoll, so I needed to convert them,
To load these into Atoll, you need to create a .txt file with each of the MSI files in each of the directories, I could do this by hand, but instead I put together a simple Python script you point at the folder full of your MSI files, and it creates the index .txt file containing a list of files, with the directory name.txt, just replace path with the path to your folder full of MSI files,
#Atoll Index Generator
import os
path = "C:\Users\Nick\Desktop\Antennas\ODV-065R15E-G"
antenna_folder = path.split('\\')[-1]
f = open(path + '\\' + 'index_' + str(antenna_folder) + '.txt', 'w+')
files = os.listdir(path)
for individual_file in files:
if individual_file[-4:] == ".msi":
print(individual_file)
f.write(individual_file + "\n")
f.close()
This series of post covers RF Planning using Forsk Atoll. We cover the basics of RF Planning in the process of learning how to use the software.
Forsk Atoll is software for RF Planning and Optimization of mobile networks.
We’ll start by creating a new document from template:
In our example we’re working with LTE, so, we’ll pick the LTE template.
(The templates setup the basic information on what we’re looking at, prediction models and defaults.)
So now we’ll be looking at a blank white document, showing our map, with no data on it, Atoll doesn’t know if the area is hilly, heavily populated, densely treed, what we’re dealing with is a flat void with no features – “flatland” a perfect place to start.
We’ll add an eNodeB (Transmitter Station and Site) from the top menu bar, clicking the transmitter icon to add a new Transmitter or Station.
Now we’ll click in the white of our map to place the transmitter site, and repeat this a few times.
Now we’ve added a few transmitter sites, let’s take a bit of a look at one.
If we take a closer look we’ll see it’s actually created us a 3 sector site, and each of the arrows coming from the site is a cell sector.
Double clicking on the transmitter will allow us to change the basic info about the site, such as it’s location, as well as display parameters, etc.
In the General tab I’ve renamed Site0 to “Example Street Cell Site”, given it an altitude (for the base of the site) and some comments,
In the Support tab I’ve put some information about the support structure the antennas are one, in our case it’s on a 30m pylon / monopole.
In the LTE tab we can specify S1 throughput (backhaul) and in the Display tab we can set the color / icon used to display this site, but we’ll keep it simple for now and confirm these changes by pressing OK.
We can give each of our other Transmitters a bit of basic info, again, same process, double click on them and add some info:
So in my example I’ve got 3 transmitter sites, labeled and each given a bit of basic info. The main thing we need to have correct for each site is the location (In our case we’re placing them anywhere so it doesn’t matter), the height of the site (Altitude -Real) and the height of the structure (Support Height) the antennas are on.
Now we’ve got our 3 cell sites in our imaginary town devoid of any features, let’s get some coverage predictions for the inhabitants of desolate featureless town!
We’ll right click on Predictions and select “New Prediction”,
There’s a lot of different prediction types, but let’s look at the Effective Service Area Analysis for Uplink and Downlink from our eNodeBs.
We’ll be asked to give this coverage prediction a name, and also specify a Resolution – The higher the resolution the more processing time but the higher the accuracy calculated.
At 50m it means Atoll will split the map into 50m squares and calculate the coverage in each square. This would be suitable for planning in really rural areas where you want a rough idea of footprint, but for In Building Coverage you’d want far more resolution, so you might want select 5m resolution say.
We’ll click Ok and now if we expand “Predictions” we’ll see our catchily named “Effective Service Area Analysis” there.
By right clicking on our prediction we can select “Calculate” and presto, we’ll have a prediction of service area from each of our cells,
Each of those pink cherry blobs represents the effective usable area of coverage provided by our network.
We may have some unhappy customers looking at this, our users will only be able to use their devices around Fake Street, Flatland Water Tower and the Our Lady of Bandwidth church.
But if we have a look at the scale in the bottom left of the screen that’s understandable, our sites are ~10km apart…
So let’s cheat a little by clicking and dragging on each cell site to bring them closer together, in real life we can’t move sites quite so easily…
You’ll notice our prediction hasn’t changed, so let’s recalculate that by right clicking on our Prediction and selecting Calculate again,
We’ll also set our zoom level from 1:250,000 to something a bit more reasonable like 1:100,000
So now our 3 sites have got one area fairly well covered, let’s throw in a few more sites to expand our footprint a bit.
We’ll add extra sites as we did at the start, and fill in those coverage gaps.
After we’ve added some extra sites we’ll recalculate our Coverage Predictions and have a look at how we’ve done.
As you can see we’ve done Ok, a few holes in the coverage but mostly covered.
So next let’s do some tweaking to try and increase our predicted coverage,
By clicking on a site’s sector we can reorient the antenna to a different angle, by recalculating the coverage prediction we can see how this effects the predicted coverage.
By now you’ve probably got an idea of the basics of what we’re doing in Atoll, how changing the location, orientation and height of cells / sites affects the coverage, and how you can predict coverage.
In the upcoming posts we’ll cover adding real world data to Atoll so we can accurately model and predict how our RAN will perform.
We’ll look at how we can use Automatic Cell Planning to get the most optimal setup in terms of power settings, antenna orientations and tilts, etc for our existing sites.
We’ll be able to simulate subscribers, traffic flow, backhaul, and model our network all before a single truck rolls.
So stick around, the next post will be coming soon and will cover adding environment data.
In our last post we talked about getting our geospatial data right, and in our first post we covered the basics of adding sites and transmitters.
There’s a bit of a chicken-and-egg problem with site placement, antenna orientation, type and down-tilt.
If all our sites were populated and in place, we could look at optimizing coverage by changing azimuths / orientations, plug in our data and run some predictions / modeling and coming up with some solutions. Likewise if we’ve already done that we might want to calculate ideal down-tilt angles to get the most out of network.
But we’ve got no sites, no transmitters and no coverage predictions yet, so we’re probably going to need to ask ourselves a more basic, but harder question: Where will we put the cell sites?
To keep this easy we’ll focus on providing the South Western corner of the Island, a town called Tankerton, with only 3 cell sites.
Manual Site Selection
In the very first post we put up a few sites, we’ll do the same, let’s place 3 sites in the bottom right of the island and attempt to provide contiguous coverage for the town with them;
We’ll pick our Station Template and set it to FDD Rural as this is pretty remote.
Next we’ll add some sites and transmitters:
Click to place it on the map and add our cell sites;
When we’re looking at where to place it, it’s good to remember that height (elevation) is good (To an extent), so when looking at where to place sites, keep an eye on the Z (Height) value in the bottom right, and try and pick sites with a good elevation.
Setting Computation Zone
As we’re only focusing on a small part of the island we’ll set a Computation Zone to limit the calculations / computations Atoll has to do to a set region.
I’ve chosen to draw a Polygon around the area, but you could also just get away with drawing a Rectangle, around the area we’re interested in.
This just constrains everything so we’re only crunching numbers inside that area.
Predictions
So now we’ve put our 3 sites out & constrained to the Tankerton area, let’s see how much of the area we’ve covered, we’ll jump to the Network tab, right click on Predictions and select New Prediction
There’s a lot of predictions we can run, but we’ll go simple and select Effective Service Area Analysis (UL + DL) & click Calculate
Atoll will crunch the numbers and give us a simple overlay, showing the areas with and without coverage.
The areas in red are predicted to have coverage, and the areas with no shading will be our blackspots / “notspots”.
We’ve covered most of the area, but we can improve.
Manually Tweaking Attributes
So there’s still some holes in our coverage, so let’s adjust the azimuth of some of the antennas and see if we can fill them.
Click on each of the arrows on the site, each of these represents an antenna / cell and we can change the angles.
So after a bit of fiddling I think I’ve got a better antenna azimuth for each of the sectors on each of my 3 sites.
Let’s compare that to what we had before to see if we’ve made it better or worse,
We’ll Duplicate the Effective Service Area Analysis prediction we created before & calculate it.
To make viewing a bit easier we’ll edit the properties of the copy and set it to a different colour:
Now I can see at a glance how much better we’re looking;
The obvious problem here is I could tweak and tweak and improve some things, make others worse, and we’d be here forever.
Luckily Atoll can do a better job of fiddling with each parameter for us and selecting the configuration that leads to the best performance in our RAN.
Automatic Cell Planning
Enter Automatic Cell Planning, to adjust the parameters we set to find the most optimal setup,
We’ll right click on ACP – Automatic Cell Planning and create a new one.
From here we set how many iterations we want to try out (more leads to better results but takes longer to compute), the parameters we want to change (ie Azimuth, Tilt, Antenna type, etc).
Setting number of iterations – Higher leads to better results but takes longer to calculate and has diminishing returnsWe’ll allow the Tilt (Electrical & Mechanical) to be adjusted as well as the Azimuth of each antenna.
When you’ve set the parameters you want, click Run and Atoll will start running through possible parameter combinations and measuring how they perform.
Once it’s run you’ll be able to view the Optomization
The report shows you the results, improvements in RSSI and RSSQ;
Here we can see we boosted the RSRQ (The quality of the signal) by 9.5%, but had to sacrifice RSRP (Signal power) by 1%.
Sacrificies have to be made, and if you’re happy with this you can view the details of the changes, and commit the adjustments.
Committing the changes adjusts all the Transmitters in the area to the listed values, after which we can run our Predictions again to compare like we did earlier.
So that’s what we’ve got when we randomly place sites, we can use Atoll to optomize what we’ve already got, but what if we left the picking of cell sites up to Atoll to look for better options?
In our next post we’ll look at Site Selection using ACP, and constraining it. This means we can tell Atoll to just find the best sites, or load in a list of possible sites and let Atoll determine which are the best candidates.
You’ve done the flatland model we did Part 1 and now you’re pumped up and ready to start plotting your cell sites, optimizing your coverage and boosting the services you’re offering.
But one thing stands in your way – The predicted & modeled data we get out of Atoll is only going to be as good as the data we’ve given it, the old garbage in garbage out adage.
So let’s get started, we’ll create a new document from Template again and select LTE.
Setting our Projection
Now before we go throwing out cell sites we’re going to have to tell Atoll where we are, this can get a little tricky if you’re setting this up for a different real world location, but stick with me and I’ll give you the data you need for this example.
We’ll select Document -> Properties and we’ve got to define a projection,
A projection is essentially a coordinate system, like Latitude and Longitude, that constrains our project to somewhere on this planet.
In this example we’re in Australia, so we’ll select Asia Pacific from the “Find In” section and scroll until we find MGA Zone 55. We’ll select it and click OK.
All this Zone information makes sense to GIS folks, there’s lots of information online about UTM datums, projections and GIS, which can help you select the right Coordinate system and projection for your particular area – But for us we’ll select MGA Zone 55 and that’s the last we’ll hear about it.
So now we’ve got that information setup we’ll hit Ok again and be on our way. Atoll now knows where in the world we are and we can start filling in the specifics.
So now we’ve still got an empty map with nothing to show, so let’s add some data.
Adding Population and Roads
We’ll start by adding some base data, we’ll import a footprint of the Island and a map of all the roads.
First we’ll import the populated area outline it into Atoll from File -> Import and select the file called EXTRACT_POLYGON.shp
We’ll put it into the population folder, this will be useful later when we try and ensure this area is covered by our network.
Although the population data is kind of rough ( <100 for the entire area) it’s still very useful for limiting our coverage area and saying “We’ve got everyone covered” when it comes to coverage.
Next up we’ll import the roads file, same thing, File -> Import, TR_ROAD.shp
We’ll import it to the Geo folder – This is just data that Atoll doesn’t process but is useful to us as humans.
Finally we’ll enable the layers we’ve just imported and center the map on our imported data to get us in the right region. We’ll do this by expanding “Population”, right clicking on the file we just imported and selecting “Center in Map Window”
You may have to tick the layer to enable itPopulation footprint with roads
Adding Elevation Data
Again, like our Datum elevation data is a standard GIS concept, but if you’re from an RF background you’ve probably not come across it, essentially it’s an image where the shade of each pixel translates to a height above sea level.
We import it into Atoll and it’s used in propagation modeling – after all we need to know if there’s a hill / mountain / valley in the way, and even slight rises / dips in the geography can have an impact on your coverage.
We’ll start by downloading the file above, and then importing it into Atoll
Next we’ll need to tell Atoll the type of data we’re importing (Altitudes) and it’s offset from the 0 point of our coordinate system, I’ve put the information we need for this into a handy table below:
West
337,966
North
5,768,108
Pixel Size
5m
Now when we move our cursor around we’ll see the elevation change in the bottom right ( z is height).
This is because the elevation data is kind of invisible (We’re looking top down) but it’s there.
Adding a Map Overlay
Ok, you’ve made it this far, let’s finally get out of our white blank map and give it some things that make it look like a map!
In order to add Google Maps / Bing Maps etc as an overlay for the first time, we’ve got to restart Atoll, be sure to save your work first.
Done that? Good, let’s add some map tiles.
We’ll right click on Online Maps -> New and select a map source from the drop down menu,
Next we’ll select a tile server, I’m using Open Street Map Standard Map, which I selected from the drop down menu,
Finally we’ll enable the layer by ticking it on the Geo panel on the right hand side. You may need to drag the layer to the top if you’ve added other layers.
All going well you’ll be looking at a map of the area, and by hovering over an area of land you should see the elevation data too.
We can even add other map layers and toggle between them or set the order by dragging them up and down.
Summary
So now we’ve got Atoll configured for our part of the world, imported height data, population data and roads, and added some map layers so we can see what we’re up to.
An important point to keep in mind is the more accurate the data you feed into Atoll, the more real-world the results you’ll get out of it will be.
Although filling in map layers and adding information seems tedious – and it is – the data-in data-out approach applies here, so the more quality data we put in the better.
If you’re doing this yourself in the real world contact your Government, they often publish large amounts of geospatial data like elevation, population, roads, land boundaries, and it’s often free.
I’ve attached my working file for you to play with in case you had any issues.
