Maybe you've never thought about it, but GPS navigation is one of the most used functions on your smartphone. Many different applications, from Yandex.Traffic to Google, work with your geolocation data. But GPS plays a much more important role than part of an application.
People who use GPS navigation while driving have probably used this system more than once to navigate an unfamiliar city in search of a parking space. Unfortunately, the overwhelming majority of modern devices cannot boast of an accurate determination of their location.
Single and dual frequency GPS navigation
The phone determines your position by receiving radio signals from satellites in orbit. Modern smartphones use single frequency GPS navigation. This means that your smartphone receives only one radio signal from each satellite. However, single frequency GPS navigation is prone to a large number of multipath errors.
Multipath errors occur when the signal bounces off large objects (buildings), resulting in only a portion of the signal reaching the device, which can lead to an inaccurate determination of your location. For the average user, such inaccuracies can lead to big troubles, especially in some metropolitan areas. This is a fairly common problem, but some phones will alert you when these errors occur.
How does dual-frequency GPS navigation deal with this problem? Instead of using one signal to determine your location, the device receives more than one signal from each satellite on a different frequency. As a result, tracking accuracy is higher than that of single frequency GPS navigation.
The US satellite navigation system uses the L1 and L5 frequencies. In the European – E1 and E5a. While most modern devices use either L1 or L5 frequencies, devices that support dual-frequency GPS navigation use both frequencies. The L5 and E5a frequencies are superior and therefore less prone to multipath errors. As you probably already guessed, the accuracy of such devices is much higher than the accuracy of single-frequency ones.
The technology of using two frequencies has appeared quite recently. In Android, support for this technology appeared with the release of Android 8.0 Oreo in August 2017. In this regard, Broadcom developed a dedicated dual-frequency chip, BCM47755, in September 2017.
The company's management announced that the first smartphones with the new chip will appear in 2018, but in the smartphones of which companies this chip will be introduced, it was not specified. The first to release a smartphone with BCM47755 was a Chinese company Xiaomi, together with its Xiaomi Mi 8, at the end of 2018. Other companies are in no hurry to release devices with the new chip. Even the recently released line of Samsung Galaxy S10 devices did not receive support for dual-frequency GPS navigation, at least in the current version of Exynos it is not.
At the moment, Huawei and Xiaomi are the only two companies whose smartphones officially support dual frequencies. At the same time, Xiaomi is the only company where dual-frequency GPS navigation is used in third-party applications.
Why aren't other manufacturers so keen to implement the new technology into their smartphones so quickly? The first is the cost of a dual-frequency chip. Such chips are quite difficult to manufacture, and they are not cheap. Secondly, companies may not consider it expedient to implement such an expensive technology in ordinary smartphones, otherwise they will have to increase their price, which may affect the number of devices sold. And for an ordinary user, a single-frequency GPS is quite enough for everyday use. But such a technology would be useful to a large number of people: tourists, independent travelers, runners and others.
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How do you know if your phone supports dual frequency GPS navigation?
On the modern market, quite a few devices support the operation of two frequencies at once. You can download many applications on the Play Store to help you understand if your device supports dual frequency GPS navigation. We recommend using GPSTest. This app is also available on GitHub. After downloading the app, all you have to do is give it permission to lock your location, and then check the CF speaker for L5 and E5a frequencies.
Sean Barbeo, the developer of the GPSTest app, keeps his column on Medium, a journalistic site that lists supported devices. The list is updated as new devices that support this technology become available.
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Which phones support dual frequency GPS navigation today?
Currently, only Xiaomi Mi 8 and Xiaomi Mi 9 officially support dual frequencies. You can verify this using third-party applications. As for Huawei Mate 20 X, Mate 20 RS, Mate 20 Pro and Mate 20, these devices are marked as supporting dual frequency GPS navigation, but due to lack of full support for some Android APIs used by third-party applications are not always able to confirm support for dual-frequency GPS navigation using special applications.
For example, the Snapdragon 855-powered Samsung Galaxy S10 is dual-frequency, according to apps such as GPSTest, but you won't find any official confirmation of this. Perhaps Samsung is just testing this technology for now, which is why they have not announced support for this technology, but this may change in the future.
Xiaomi and Huawei are the only manufacturers who consider this technology a profitable investment. Apparently, they are not going to abandon it in their future devices.
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Dual-frequency GPS navigation technology is completely ready for implementation in mobile devices, but for some reason large companies are in no hurry. We can only guess why, most likely, the underlying factor is its high cost. Perhaps Xiaomi decided to take a chance in the hope that it will bear fruit.
Dual-frequency GPS navigation, in the future, may turn out to be an urgent need for large cities, where multipath errors can already be considered a very common problem. In connection with the imminent completion of the joint project of the European Union satellite navigation system “Galileo”, now is the time to think about the start of production of devices with support for dual-frequency GPS-navigation.