Locating a Phone Tower

Locating a Phone Tower main image Locating a Phone Tower image

 

Overview

 

Deciding on the right antenna can be a difficult task, but with a little computer skill you'll be able to confidently select the right antenna for your situation. This guide will help you locate your nearest phone tower and work out a suitable antenna. This guide is only suitable for areas where a weak signal is already present, and should not be followed for locations where no service is receivable at all, or highly complex terrain. We offer a formal computer survey using highly advanced computer software, which you can book the following link: Detailed Assessment Booking Before you start - you will need: - Internet access - A street address, or GPS coordinates - Google Earth (available here: http://www.google.com/earth/index.html) This guide is a follow on from our previous guide Selecting the Right Antenna. If you have not read the document, it is highly advisable to do so before continuing.

 

Introduction

 

As you might already know, the terrain surrounding your location, density and depth of vegetation, and distance to the nearest tower, are often the main reasons behind your weak signal strength. Hence the right antenna for your situation will be different if you live in a hilly area or if you live in a flat area, or if you live in the suburbs or out in the country. In order to determine the type of antenna you will need, we first must diagnose the problem.

 

Step 1

 

The first thing we must do is look at the area you are having problems in. To do this, we will be using a program called Google Earth - which will allow us to view satellite imagery of your location, and also to take a look at the hills and mountains in 3D. Along with Google Earth, we'll also use an Australian tower location website http://oztowers.com/ This site will allow us to type in our post code, and pull up a map of towers surrounding the area. We will be combining the locations obtained from this website with Google Earth to get a better look at your situation. If you haven't already installed the program on your computer, you'll need to download it here: http://www.google.com/earth/index.html Once installed, opening Google Earth will look like this.
Now we're going to have a look at your location. Type in your address in the 'Fly To' box.
Google Earth should now look something like the following. Google gets about 60% of rural addresses slightly incorrect, you may need to pan around to find your actual house location. It can help to locate identifiable roads or landmarks and zoom in from there. Once you've located your house use the thumbtack symbol to "Add Placemark" on your address. This is used to save your location and also to determine the GPS coordinates of your house which you may need later.

 

Step 2

 

Although pretty, Google Earth doesn't exactly help us on its own. In Step 2 we use another program to obtain the GPS coordinates of the nearby towers. We need to check out the towers near your address. To do this, go to http://oztowers.com.au/Home/Query When you first open the site, it will look something like this. This website is incredibly easy to use, simply type in your postcode or suburb in the box, and hit the search button. The next page will display a table of all base stations in the area, and which networks (Telstra, Optus, etc) and frequencies are in use at each site. It's important to note not all these towers are in use, as this website shows both current and proposed base stations. If you're like most people it's easier to grasp if you get a visual representation of the tower locations, to do this simply hit 'map view'. There are quite a few towers displayed so it's necessary to sort through and identify those relevant. Fortunately each site has a T, O, V, N, or a combination of these letters which corresponds to each carrier (e.g. T = Telstra, N = NBN). To identify what services are available from each site, simply click the tower which will display the network and frequencies in use. While a comprehensive identification of all relevant towers in your area is best, you can use your local knowledge to rule out towers that are not likely to be receivable due to the presence of significant terrain obstructions. As you can see above we've identified a Telstra 3G ("Next-G" 850MHz) tower, and a Telstra 4G tower just behind it. Now to determine it's location we can either type in the street name displayed in the popup box into Google Earth, or use your local knowledge of the area to pan around on Google Earth to locate it visually. In this case we've typed "Helena St, Mirani", and located the tower - or in this case, water tower - visually using the approximate location displayed on the OzTowers map. It's important to repeat the process for all relevant towers that are likely to be in range of your address, out to about 40-50km in most cases. The best tower serving your address is going to be the one with the least terrain obstruction, and least vegetation that signal must penetrate through to reach your location.

 

Step 3

 

Here we're going to assess the terrain between you and each tower. To do so we are going to make use of some powerful tools built into Google Earth. While inside Google Earth, zoom out to a distance where you can clearly view both your address and the tower in the picture. Select the 'Add Path' button. This will bring up the box shown in the below image. A colour such as red or white may help improve the visibility of the path on the map. Do not click ok just yet. Click once on your address, and then click on the tower. This will draw a straight line between the two points. Then click the ok button. Now, all we need to do is right click on the line and select 'Show Elevation Profile' this will graph Elevation against Distance between the two points. We will use this to determine if there are any geographical obstructions between the two points, and to determine the appropriate gain antenna based on the obstructions and environment.
We can also use the navigation tools on the right hand side of the page to view the terrain in 3D. This can be used to virtually examine the terrain if you're assessing an unfamiliar location. It's important to identify the locations of dense vegetation and large groupings of trees that obstruct the path. This process should now be repeated for all relevant towers in the area, with the tower that appears to have the clearest transmission path selected as our candidate.

 

Step 4

 

Before choosing an antenna, it's important to understand why signal strengths might be poor. Mobile phone and wireless broadband uses a radio frequency transmission to reach your area. Ideally all transmissions should have a clear path from the transmitter (tower) to the receiver (you), as this is rarely the case radio waves tend to 'bend' over the tops of hills (a process called diffraction), or bounce of nearby buildings or hills. Radio waves can of course penetrate through vegetation however the more bush land the transmission must penetrate through, the weaker it becomes. Likewise the greater the angle the transmission must bend over hills, or the more acute the angle must bounce off a hillside, the weaker the signal you'll receive. Consequently signal is quite poor at this location due to the very low ground clearance and as such high levels of vegetation the signal must pass through. This location isn't too bad given that most of the area is farmland, were this location to be in a forested area it's likely no service would be available whatsoever. The key to antenna selection is that we ideally use the highest gain antenna possible. But due to the transmission environment highest gain is not always the best - using a high gain antenna focuses signal into a very fine angle called beam-width. The higher the gain, the smaller the receiving angle. Beam-width is essentially the antennas aperture, meaning any signal being scattered through trees or bouncing off nearby hills outside this angle won't be picked up by the antenna. Normally, because we're dealing with very low ground clearance and only a moderate-short distance we would need to maintain a reasonably wide receiving angle (wide beam-width) to ensure we capture signal that's scattered from all the ground based obstructions. While this would provide a reasonably good performance connection, we can go one better by improving ground clearance and thus minimizing the cause of the problem to begin with. To do so, we would simply install a decent roof mast, perhaps a 2-3m mast installed on top of our ~3m roof to achieve 5m of ground clearance. From this point we can now use an antenna of as high gain as we would like. If you'll recall Mirani had both 3G and 4G towers, meaning that we can achieve both good mobile phone coverage throughout the house, and very high speed 4G internet. The two kits we might select would be the following: Mobile Phone Coverage: Rural Repeater Kit 4G Internet: High Gain Dish And that's pretty much all there is to it. Of course this is a reasonably simplified way of locating nearby towers and determining a suitable antenna, and should only be used in areas where signal is already present. We always encourage the formal surveying of your location, which we provide as a service available here.