Tag Archives: RF Planning

Automatic Cell Planning with Atoll: Site Selection

Mobile Networks, Notes, Software, , ,

One of the really neat features about using automated RF planning tools like Forsk Atoll is you’re able to get it to automatically try out tweaks and look at how that impacts performance.

In the past you’d adjust something, run the simulation again, look at the results and compare to what you had before,

Atoll’s ACP (Automatic Cell Planning) module allows you to automate this, and in most cases, it does a better job than I would!

Today we’ll look at Cell Site Selection in Atoll.

To begin with we’ll limit the computation area down to a polygon we draw around the area in question,

In the Geo tab we’ll select Zones -> Computation Zone and select Edit

We’ll create a new Polygon and draw around the area we are going to analyze. You can automate this step based on population levels, etc, if you’ve got that data present.

So now we’ve set our computation area to the selection, but if we didn’t do this, we’d be computing for the whole world, and that might take a while…

Generating Candidate Sites

Atoll sucks at this, I’ve found if your computation zone is set, and it’s not a rectangle, bad things happen, so I’ve written a little script to generate candidates for me.

Creating an new ACP Job

From the Network tab, right click on ACP Automatic Cell Planning and select New

Optimization Tab

Before we can define all the specifics of what we’re looking to plan / improve, we need to set some limits on the software itself and tell it what we’re looking to improve.

The resolution defines how precise the results should be, and the iterations defines how many changes the software should run through.

The higher the number of iterations, the better the results, but it’s not linear – The improvement between 1000 iterations and 1,000,000,000 iterations is typically pretty minor, and this is because ACP works kind of a “getting warmer” philosophy, where it changes a value up or down, looks at the overall result and then if the result was better, changes the value again until it stops getting better.

As I’m working in a fairly small area I’m going to set 100 iterations and a 50m resolution.

In the optimization tab we can also set constraints, for example we’re looking at where to place cell sites in an area, and as far as Atoll is concerned if we just throw hundreds of sites at an area we’ll have pretty good results, but the economics of that doesn’t work, so we can set constraints, for example for site selection we may want to set the max number of cell sites. As we are importing ~5k candidate locations, we probably don’t want to build 5k cell sites 20m apart, so set this to be a reasonable number for your geography.

When using ACP for Optimization as we can see later on, we can also set cost constraints regarding the cost to make changes, but for now this is just going to pick best cell sites locations for us.

Objectives Tab

Next up we’ll need to setup Automatic Cell Plannings’ objectives.

For ACP to be an effective tool we need to define what we’re looking for in terms of success, you can’t just throw it some values and say “Make it better” – we need to define what parameters we’re looking to improve. We do this by setting Objectives.

Your objectives are going to be based on your needs and wants, but for this example we’re building greenfield networks, so want to offer coverage over an area, as well as good RSRP and RSRQ, so we will set the objectives to Coverage of 95% of the Computation Zone for this post, with a secondary objective of increasing RSRP and RSRQ.

But today I’m modeling for coverage, so let’s set that:

As we’re planning for LTE we need to set the UE parameters, as I’m planning for a mobile network, I’ll need to set the service type and terminal.

Reconfiguration

Now we’ve defined the Objectives, it’s now time to define what values ACP can mess with to try and achieve these objectives, for some ACP runs you may be adjusting tilts or azimuths, swapping out antennas, etc, but today we’re looking for where we can put cell sites to be the most effective to serve our target area.

Now we import our candidate list. This might be a list of potential towers you can use, or in my case, for something greenfield, I’m just importing a list of points on a map every X meters to find the best locations to place towers.

From the “Reconfiguration”, we’ll select “Setup” to add the sites we want to evalute.

Atoll has “Automatic Candidate Positioning” which allows it to generate pins on the map, but I’ve not had any luck with it, instead I’m importing a list of candidates I’ve generated via a little Python script, so I’ll select “Import from File”.

Pick my file and set the parameters for importing the data like so.

Now we’ve got candidates for cell sites defined, we set the station template to populate and then we’re good to go.

Running ACP

Once you’ve tweaked all your ACP values as required, we can run the ACP job,

As ACP runs you’ll see a graph showing the objectives and the levels it needs to reach to satisfy them, this step can take a super dooper long time – Especially if your computation zone is large or your number of candidates is large.

But eventually we’ll be a lot older and wearier, but ACP will have completed, and we can checkout the Optimization it’s created.

In my case the objectives failed to be met, but that’s OK for me,

One it’s completed the Changes tab outlines the recommended changes, and the Objectives outlines how this has performed against the criteria we outlined at the start, and if we’re happy with the result, we can Commit the changes to put them on the map from the commit tab.

With that done I weed out the sites in impractical locations, the the ones in the sea…

Now we’ve got the sites plugged in, the next thing we’ll start doing is optimizing them.

When we’re dealing with greenfield builds like we are today, the “Move to highest location with X Meters” function is super useful. If you’ve got a high point on a property, we want to build our tower on the highest point, so the tower is moved to the highest point.

One thing to note is this just plans our grid. It won’t adjust azimuths, downtilts, etc, in one operation. We need to use another ACP operation to achieve that, and that’s the content of a different post!

Forsk Atoll – Importing Antennas

Python, RF, , ,

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()

Which you can then import into Atoll, easy!

Radio Planning with Forsk Atoll Tutorial – Part 1 – The Basics: Sites and Transmitters

EUTRAN, LTE, RF, Software, ,

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:

Create new document in Forsk Atoll

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.

Blank Document in Forsk Atoll showing no sites.

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.

Populating the map for LTE planning in Forsk Atoll

Now we’ve added a few transmitter sites, let’s take a bit of a look at one.

Atoll single cell

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.

Forsk Atoll 101 – Part 3 – Manual Site Placement

EPC, EUTRAN, LTE, Software, , ,

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 returns
We’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.

RF Planning with Forsk Atoll - Laying out environmental data

Forsk Atoll 101 – Part 2 – Where are we?

EUTRAN, LTE, RF, Software, ,

So you’re here, reading this.

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 welcome, to the world of GIS my friend.

So let’s start with a location we’ll plan a cell service roll out for, in this case I’ve picked French Island, an island in Port Philip bay in Australia, 61 Km from Australia’s 2nd largest city. French Island has no mains power, water or sewerage, no connection to the mainland, no council, hosted an Alcatraz style prison and at one stage was going to be the site of Australia’s only nuclear power plant. Most of it’s inhabitants are Kolas, and thought this tutorial, we’ll setup the island with cell coverage.

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.

Download and extract this archive of Shapefiles Download

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 it
Population 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.

Elevation DataDownload

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:

West337,966
North5,768,108
Pixel Size5m

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!

I’ve written a post on how to add these map layers, it’s very simple and involves editing just one file. Save your work, close Atoll, follow the instructions in this link and reopen your Atoll file.

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.

Atoll-101-Part-2-CompletedDownload

In the next post we’ll add some cell sites and look at placement.