They want to build a second world, a virtual one, and they connect it to the real one. Mobile communications, according to the vision of the telecommunications providers at the Mobile World Congress industry meeting in Barcelona, will envelop people wherever they are, control production and logistics, and monitor and direct traffic. But even if these bold ideas come true at the moment: It is also true that the mobile network will not and cannot be everywhere. Which is why another technology has long been promoted: satellites.
It’s not just about areas like the Mongolian steppe, the endless expanses of Canada or Siberia. It’s obvious that you can’t and don’t want to set up a radio mast there every few kilometers – they would also have to be supplied with electricity and connected with a fiber optic cable. But even in densely populated areas there are dead spots, and it will remain so for the foreseeable future.
Satellite communication is to step in for the remaining, previously unserved areas. Most recently, Apple caused a stir with the launch of the iPhone 14 with a feature that allows text messages to be sent from the iPhone to rescue services via satellite. For this, however, the mobile phone must be aligned with the satellite. An app helps to find the best position.
Only text messages are possible
The outdoor mobile phone S75, which the British manufacturer Bullitt sells under the Caterpillar brand, or Cat for short, works in a similar way. Bullitt has built hardware for this with the chip developer Mediatek that uses the so-called narrowband IoT. This is otherwise used, for example, to connect sensors to motorway bridges or in large factories. They don’t have to transfer huge amounts of data, but mostly just a few values. The Cat cell phone can send text SMS or text messages via an app.
If you don’t want a particularly hard-wearing mobile phone, but want to be on the safe side when hiking, for example, there is a small box, smaller than a pack of tissues, that contains the chip for satellite communication. It is connected to the mobile phone via Bluetooth and can also only send text messages. These are forwarded to ground stations via one of the geostationary satellites of the operators Inmarsat or Echostar and from there to the receiver. Cost: From five euros for 30 messages per month.
But that’s just one of the options available here. The network supplier Ericsson, for example, is also working on supplying poorly covered regions with a kind of emergency network. Together with the chip manufacturer Qualcomm and the aviation experts Thales, the Swedes have developed a prototype that also allows larger amounts of data to be transmitted.
The closer the satellites, the more data can be transmitted
The idea is for emergency operations where there is no network or where it has failed as a result of a natural disaster. For this purpose, a 5G radio cell will be set up, the data from which will be transmitted to the emergency center via satellite. The bandwidth is around ten megabits per second, which means that a video stream can be transmitted in HD quality – just like on television. Multiple streams also work at the same time. However, the most important one is then prioritized and transmitted in reduced quality with blocks. The Swedish company has already developed software called Swedome that ties all of this together. It is currently being “tested in a realistic scenario” by the Swedish police, as the company boss says. The images are transmitted to large monitors or – for example when used outdoors – to VR glasses.
The higher data rates at Ericsson and Co. are possible because the companies do not rely on geostationary satellites, as with the Cat cell phone, whose position is known but is quite far out, around 36,000 kilometers. In contrast, low-Earth satellites, such as those used in Ericsson’s emergency project, fly at an altitude of only about 200 to 2,000 kilometers. They cover about seven kilometers per second, so you need a lot of them to continuously cover large areas of the earth.
Advantage of the Ericsson development: You don’t need a satellite antenna on the ground like with Elon Musk’s Starlink satellite internet. But the right chip must be in the smartphone. However, it is not yet available for purchase. However, the technology is definitely ideal for covering areas that would otherwise be difficult to provide with mobile Internet.