To begin with, you need to understand that several steps & components are required for it to be possible to track an object or a person with the help of GPS. In a first step, we need to place a transmitter with a GPS chip on the object we want to track. This GPS chip is powered by a battery and contains antennas that allow the chip to communicate with the satellites to determine where the tracking chip is currently located. The position is triangulated and transferred to the transmitter, which with the help of the built-in processor translates this into ordinary coordinates (longitude and latitude). This means that the transmitter knows at which coordinates it is located. However, this information is only stored deep inside the advanced GPS chip - the next step is to tell the user where the tracking object is located.
Three existing methods for positioning the GPS transmitter
There are currently three common methods used to position the GPS tracker.
- Walkie-talkie model. One way is what is commonly referred to as the walkie-talkie model. The way the model works is that the GPS tracker containing a radio transmitter, transmits the coordinates to a specific handheld device. The handheld device usually contains maps - in the same way as the GPS navigator in a car - and with the help of the handheld device's software, the coordinates are pointed out on a map. This is so that the user can visually see where the GPS tracker is. The following was previously the most common transmission method in the early 2000s, but the disadvantage of this technology is that the range is limited - at most this method usually gives a range of a few kilometers. In addition, the user needs to invest not only in a GPS tracker, but also in a handheld receiver unit. Therefore, we at SweTrack have chosen not to use this transmission method in our products.
- The Bluetooth model. Another method, which has become very popular in recent years is bluetooth transfer. This is usually found on the smaller and cheaper options on the market. Most often, these solutions also lack a GPS chip. Instead they use bluetooth and measure the signal strength, which is converted to an approximate positioning. Solutions based on the bluetooth model are known to be able to operate with a low power consumption and cheap operating costs, as no external networks need to be used. However, this technology has major shortcomings when it comes to coverage and reach. This is because bluetooth usually only supports a few meters in range. The most common models support at most around 40 meters, and the most advanced bluetooth transmitters can today support up to 120 meters in ideal conditions such as open surfaces.
In other words, for an optimal tracking solution for a vehicle or object that can travel more than a few meters away from the user, this is an incompatible method. Thus, we at SweTrack have chosen not to use this transmission method in our products.
- Mobile mast model: The third and best (in our opinion) option is to use mobile mast transmission. Which in short means that the transmitter has a built-in radio chip with an associated SIM card that communicates with established mobile masts that are found in all countries around the world. This enables tracking of a GPS transmitter whether it is located in the garage driveway, highway or in another country. Simply explained, each transmitter contains a small built-in mobile phone. This radio chip, or mobile phone, uses the standard mobile network to transmit the information to you as a user. The device can also use all mobile operators in all countries, which means that it constantly searches for the operator with the best coverage at the moment and uses that mobile network. This technology has been proven for a long time and is used by everyone who owns and uses a mobile phone. The networks are therefore well developed worldwide and have superior operational reliability compared to other similar technologies.
That is why we at SweTrack have chosen to use this transmission method in our products.
How is the information sent to the user?
How is this information usually transmitted, and how is it done? What happens to the information and how is it handled?
There are currently two common methods used for communication via mobile masts between humans and GPS trackers:
- The SMS method. One way is what in everyday speech is called SMS tracking, and it is not really more difficult than the GPS tracker communicating with the user via SMS. This was the most common and almost the only method used between the 2000s and 2010s in consumer GPS tracking products.
The way it usually works is that when the user wants to find out the current position of the GPS tracker, an SMS is sent from the user's phone to the GPS tracker with a position request. For example, an SMS with the text POSITION and often followed by a password, i.e. POSITION123456.
The GPS tracker then answers back with an SMS to the user's phone with the coordinates of their current position, and usually also with a Google-Maps link where the current position is presented. This requires the user to constantly request the position manually, or set so that you receive automatic SMS updates with the position at certain times, for example once an hour. Since the device's current positions are then saved in a handful of different SMS in your phone's message app, it becomes very difficult to go back in time and be able to see routes or get a good and quick overview of where the vehicle has been. As this is an outdated method, all our previous products from 2013 have been discontinued and replaced with modern technologies, in other words SweTrack does not use this method today.
- Client <-> Server method. In everyday speech, this method is called live tracking. This means that the GPS tracker (client) is connected to a computer system (server) with which it is constantly in contact and communicates.
Technically, it works as if instead of sending an SMS back and forth, the device talks to a server over the mobile network.
When the GPS tracker has located its current position or noticed, for example, an alarm, this information is sent to the server that the device is talking to. How this information is handled can work differently for different products and suppliers. Some GPS tracking providers only receive the raw information, while others do calculations and more.
Example of how we at SweTrack communicate between the servers and the devices.
Below is an example of how we at SweTrack communicate between the servers and the devices.
Step 1. The GPS tracking device sends the information to the servers over the mobile network.
Step 2. The servers check the identity of the GPS tracker and ensure that the correct permissions are available and then receive the information. When the information is received, the server responds with a thank you message and the device then knows that the message has arrived correctly.
For you tech nerds like us at SweTrack, you probably just thought hmm ... it must be TCP they use, and I can confirm that you are completely correct.
Step 3. Now that the information has been received, it is decrypted from an incomprehensible line of text mixed with letters and numbers. Examples of a message from a device can be the following: 86hd352GSj223811kDd22SLSK22FfdSkdkdhqrwyveeEO281ayretdzxtxgkwGqwKdfsssyDDwh01
Step 4. The decrypted data is run through algorithms, filters and control functions.
For example, check here if the new position is inside or outside an activated geofence. In that case, create a geofence alarm.
Here, information from previous positions is also used to calculate, for example, differences in battery level, different alarms and ensure as good a positioning as possible.
After all calculations have been made, the relevant information is saved in the server's database and any alarms that have been noted are sent out as notices.
This method also enables a bunch of different background activities, such as the server and the device checking their status and talking to each other. The server checks that the device has the latest updates, automatically sends out new updates, and checks that the device is working properly. The advantage of saving the information in databases instead of in a variety of SMS as in previous examples, is that history and position can be easily displayed on a computer or mobile app.
As the device also continuously sends up its position when it is active, you can accurately see the device's location history.
Due to all these possibilities that a cloud-based service holds, we at SweTrack use this method to be able to provide the best and most user-friendly solution.
How can I see the information from my GPS transmitter?
Here, like the above steps, there are different technical solutions. Some models and vendors forward this decrypted data and information to a third-party solution that has a front-end (computer and mobile app) where the user can view the information. We at SweTrack have instead built an API and our own front-end applications that are available for browsers, iOS and Android. The apps talk to the API and can both retrieve and write information to the GPS tracker.
In the SweTrack Live application, which is available for both browsers, iOS and Android, the current position is then drawn on a map. This is so that you as the user can easily see where their transmitter is located. Via the app, you as a user can also see your transmitter's previous positions on the map as well as see alarms and other information from the device.