In the past, the only satellite system available globally was GPS (operated by the United States), and any GPS receivers or modules had to rely on their satellites to function. This has changed in recent years, as other satellite navigation systems have begun to operate (or semi-operate) to compete with GPS. These include Glonass of Russia, Galileo of Europe, and BeiDou (Compass) of China. These new satellite signals can either compliment GPS or even work independently. This brings us to the definition of Multi-GNSS.
A Multi-GNSS receiver or system is able to get your location by simultaneously using signals broadcasted from multiple satellite navigation systems.
Multi-GNSS modules allow simultaneous positioning from at least up to two satellite navigation systems, resulting in much better positioning accuracy, compared to standard GPS-only modules.
Most ‘Multi-GNSS’ modules today can support all the four major satellite navigation systems on the same hardware, though typically only two can be enabled at a time. You can change from one configuration to the other via a simple firmware change (though you may need to change your GNSS Antenna). The main configurations for Multi-GNSS modules available these days are :
GPS+Beidou demand is rapidly increasing in China (and south-east Asia), while GPS+Glonass is the most common variant used globally, and pretty much the norm already. This wasn’t the case back in 2011 when we saw the very first Multi-GNSS modules. At the time, GPS+Glonass modules were up to 4 times more expensive than GPS-Only modules, and the power consumption was dreadful, to say the least.
Multi-GNSS positioning technology has come a long way since then. It has since been adopted in major consumer applications like cell phones and tablets, driving down the Multi-GNSS chipset costs considerably, which in turn has also helped Multi-GNSS module vendors. Today, Multi-GNSS modules only cost a fraction more than GPS-Only modules. The power consumption difference has also become negligible (to some extent) and is something that is constantly being improved. For many M2M device makers, the minor increase in cost and power consumption is still worth the far superior positioning accuracy that is offered by Multi-GNSS engines.
As major high-volume consumer applications have shifted from using GPS chipsets to Multi-GNSS chipsets, the GNSS IC industry has changed their priorities as well. The demand for GPS-only IC is continuously dropping in to a niche, while demand for Multi-GNSS is on the rise. This has forced major GNSS IC vendors to become primarily focused on the improvement and innovation of their Multi-GNSS chipsets. At the current rate, it will not be long when manufacturing Multi-GNSS chipsets will eventually become cheaper than making GPS-Only chipsets, and these changes will be reflected at module vendors’ side as well (especially those using third-party GNSS ICs). In fact, we are already seeing this trend, with GPS prices at a standstill while GNSS prices continue to drop each year, which will eventually close the price gap.
Starting from 2016, we will slowly start to see the rise of triple-mode multi-GNSS modules, that will allow simultaneous positioning from up to three (instead of two) satellite navigation systems. Broadcom (A GNSS IC vendor) for example, showcased a product that could get simultaneous positioning from all the 4 satellite navigation systems. ST’s TESEO III chipset also support simultaneous positioning from up to three satellite systems. Other major GNSS IC vendors are likely to follow the same path very soon.
The use of GPS-Only module in devices will not die, perhaps due to security or even political reasons, but core hardware such as GPS-Only chipsets and modules eventually will. In other words, we will not be seeing many dedicated IC’s and Modules being made for GPS-only in the future. If somebody has to use “only” GPS in their device, all they would have to do is switch-off the other satellite systems in a Multi-GNSS chipset/module.
It’s already known that by 2020, Galileo and Beidou will be fully operational, and we will have an estimated 100 to 120 GNSS satellites in orbit. It’s also expected that by then, Glonass and Beidou will be able to work on the same frequency band as GPS and Galileo. This will make it even cheaper to make multi-constellation silicon. Hence, the move towards Triple or Quad Constellation GNSS receivers is inevitable, and it might even happen in as little as 2 to 3 years (at least on the IC & module side).
For M2M-device makers starting new designs, it’s worth considering Multi-GNSS modules instead of GPS-Only modules, if you want to ensure that your products will still be competitive, both in terms of positioning performance and cost, a few years from now.