The new iPhone 14 impresses with its SOS emergency feature for satellite emergency calls. How does it work and is it available on any other smartphone
How it works
Satellite phones have been around for three decades, but they are still expensive, inconvenient and rather bulky. One of the innovations of recent years is satellite communication on ordinary phones - but this requires new satellites. Previously, satellite phones worked using a small number of satellites orbiting the Earth. But over the past five to seven years, the two main players - Iridium and Globalstar - have launched a fair number of satellites orbiting the low Earth (LEO), operating at an altitude of only 500-800 kilometers. The most exciting project of this kind is undoubtedly Elon Musk's Starlink. However, while using a similar technology, Starlink is aimed at a relatively high-speed internet, and requires the subscriber to purchase a special terminal. However, in late December 2022, the first Starlink Gen2 satellite was launched, which will also provide connectivity for ordinary smartphones - non-satellites.
Satellites communicate with a phone in the relatively low-frequency L-band (1.5-2 GHz). GPS and GLONASS satellites, orbiting about 20,000 kilometers above the Earth, operate in the same frequency range. The advantages of this range are the low levels of both signal decay over long distances and interference with the weather. Thanks to this, the satellite can "hear" the weak transmitter of the phone. The main disadvantage is the low data transfer rate. That is why all the satellite-based services that we are discussing today are mainly based on the SMS format: 140 characters per message, not a selfie on the horizon.
To support satellite communication, three things are needed from the phone: modem support for the satellite network radio protocol, a modified antenna, and special software. The most difficult is the first , because such a modem not only needs to be produced in the first place, but also coordinated with the satellite operator. It is not surprising that Qualcomm is the leader of the group, which not only dominates the mobile chipset market, but also has almost 30 years of experience in satellite systems (after the joint founding of the Globalstar network in 1994). So, the first large-scale launch of satellite telephony became possible thanks to the knowledge of Qualcomm and Apple's financial muscle. The latter paid for the feature that will be implemented in the new iPhone chips and, most importantly, invested 450 million US dollars in the development of the Globalstar network, its satellites and ground stations.
Apple was the first to enter the market, but it certainly will not remain a monopolist. At the same time, Qualcomm has implemented the feature in the Snapdragon X70 modem chip, which is part of the Snapdragon 8 Gen 2 Mobile basic platform. The Snapdragon Satellite service was announced in partnership with the Iridium network, so in H2 2023 we can expect (expensive) smartphones capable of sending and receiving text messages via satellite.
Other players on board are also scrambling: Huawei plans to introduce a similar service in its smartphones using the BeiDou satellite navigation system in China (although there are no details on timing or coverage); Motorola is partnering with satellite provider Skylo (Inmarsat); and the aforementioned Starlink has concluded an agreement with the American operator T-Mobile to participate in the deployment of such a service on 1.9 GHz bands licensed from T-Mobile.
For future fifth-generation devices, the ability to connect to satellite base stations instead of terrestrial ones has already become standardized. But the actual devices with this function are intended to appear no earlier than 2024.
Quality and coverage
Technology imposes its own limitations, which will be the same as who makes the phone.
- One, it is definitely slower and less reliable than a cellular connection. Thus, the phone will offer the satellite option only in the absence of another connection, and with significant restrictions so as not to overload the network: one 140 - character text without Multimedia-in emergency situations, for example. Apple makes this very clear: first, the phone determines the exact location and asks for some details about the situation, and then combines the collected information and sends it as one package.
- Two, the satellite link works only in open spaces. There is no correlation in dense forests, dense urban areas, or rocky valleys.
- Three, sending a text is not as simple as we are used to. You need to: hold the phone in front of you, turn in the right direction, follow the instructions on the screen, and then wait 10-60 seconds for hundreds of bytes to be sent and received
- Four, depending on the satellite provider, the service may not be available in certain regions. This is perhaps the biggest drawback at present-the lack of a developed market for satellite communications or roaming. As such, both Globalstar and Apple offer Emergency SOS service in the United States, southern Canada and some countries in western Europe. Satellites generally do not serve high latitudes (above the 62nd parallel), which leaves Alaska and northern Canada, for example, out of reach. The situation with Iridium is better: its satellites operate at the equator and the poles. The only thing missing is compatible Android terminals from Qualcomm partners. Some satellite towers have gaps in their coverage, so Service to certain places is not provided around the clock on weekdays. This does not apply to Apple and Qualcomm services, but some competitors may display the message "please try again in half an hour" at the crucial moment.
Prices
No one has any clear idea yet about the cost of the service. It is clear that it will not be a mass market, since most people live within the coverage area of a regular cellular network. What is the additional cost of emergency communications, and in what form, the market will test and determine in the coming years. Apple provides this service for free, but only for two years after buying a new iPhone. What will be the subscription fee then the company has not announced. But the use will be modest, because Apple positions the feature as an emergency communication channel only. All we know now (at the time of publication of this blog) is that Motorola plans to charge 5 USD for 30 messages. But these can be any messages - and not just emergency ones.
Protection
Texting is widely known to be an insecure communication channel. So what about the specificity of satellite texts Apple says that its messages are packaged and encrypted, which makes it almost impossible to fake or intercept them when sent from a phone to a satellite. However, since it concerns an emergency, the company immediately forwards the information to the response center closest to the subscriber (Rescuers, firefighters, etc.), where it is no longer encrypted and processed according to the procedures of this center. The same applies to the Snapdragon Satellite service, which is based on the Garmin inReach infrastructure: the data transfer itself is encrypted, but the operators then handle the decrypted text. When sending text messages to friends, not emergency services, do not rely on end - to-end encryption-all specifications only mention encryption in transit. The good news is that this excludes the replacement of the return address or the replacement of the message body.
To look at what to expect from phones in the foreseeable future, take a look at the ads for the inReach service, for which specialized devices have long been available. Among the features that may be unsafe in terms of privacy, the periodic transmission of the subscriber's location to the satellite to enable their friends to track their ascent to the mountain, for example. To date, no service based on traditional smartphones promotes this option - only sending the location on request. But considering that you have to take out your smartphone and spin in search of a satellite, you don't have to worry about the hidden transmission of the location, at least for now. But it is worth monitoring the development of this technology.
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