5G NTN new trends: directly communicate with mobile phones and satellites, foreign companies have already acted

Author:Satellite and network Time:2022.08.04

Wen | Wei Xing

In mid -June 2022, 3GPP of international organizations that formulated global mobile communication standards officially frozen the Release17 version of the 5G protocol. In this version, the so-called "Non-Terrestric Network (NTN)" function that supports direct communication between mobile phones and satellites is officially defined. Human beings have taken a big step on the Internet anytime, anywhere. Think about it, whether you are on the mountains, the desert or in the ocean, in the places where there is no ground to move the network, take out your mobile phone, you can swipe the vibrato at any time like the city center, and talk about WeChat. How much is this? A beautiful era! This era is in front of you!

However, if you eat a bite at a time, do things step by step. In the 3GPP Release17 standard, the services we can get are just sending text messages through the satellite through the mobile phone, and also supporting some IoT devices to send a small amount of data through the satellite. In the version of the 3GPP standard, it is possible to gradually add a mobile phone to the function of voice calls and broadband Internet access directly through satellites.

Maybe some friends will ask, can the maritime satellite call and the star call of the maritime satellite and the star phone be sent for text messages as early as two or three decades? You can also make voice calls. What are the freshness of these technologies defined by 3GPP? There are still essential differences!

For consumers, satellite telephones are not always necessary. For most of the time, we all live in areas covered with ground mobile communication networks. We can always enjoy cheap and convenient network connections. , Bear expensive satellite communication costs? For mobile phone manufacturers, under the traditional satellite communication technology, their mobile phone products cannot be directly connected to the satellite, but under new technologies, it is possible. In order to ensure that consumers are not threatened by electromagnetic wave radiation, most countries in the world stipulate that the maximum transmitting power of mobile phones and Wi-Fi devices does not exceed 200 miles in frequent FDD mode. No more than 400 mile. At this point, the power was reduced to one -tenth of the traditional satellite telephone. Only by relying on the latest satellite technology, the high -sensitivity receiver can be achieved.

In addition, there are many technical difficulties in ordinary mobile phones to directly connect satellite communication: for example, in order to maintain compatibility with our existing mobile communication networks, satellites also need to use the existing mobile communication network air interface technology. However, because the satellite is flying at the speed of the first universe, it is much faster than the maximum speed supported by our ground mobile communication network. This requires additional compensation on the physical layer of the mobile phone; for example, the height of the low -earth orbital satellite distance is more than 500 kilometers, and the coverage of ground base stations usually does not exceed 35 kilometers. This is not because of base stations and mobile phones from mobile phones. The lack of power is not enough, but it is mainly limited by the high -precision time frame of the mobile communication protocol. Therefore, if you want to realize direct communication with the mobile phone and satellite, you need to modify the timely advance (TA) mechanism. In addition, there are other technical issues. It is gratifying that these technical problems are solved in the 3GPP Release17 version. These solutions are mainly applied to satellites, and some need to modify the underlying communication protocol of mobile phones. In the future, mobile phone chips will generally support 5GNTN functions, and for existing mobile phones, it may also be supported by upgrading the firmware. It depends on the plan of mobile phone manufacturers.

Before the 3GPP Release17 standard freezes, the communication and satellite industry talks more and do less about direct communication with mobile phones and satellites. But when the standard freezes, many companies have taken action. It is expected that it is expected that it will be convenient for people to communicate directly with mobile phones and satellites.

At present, some companies have deployed and carried out work in this direction to strive to provide direct communication services for mobile phones and satellites as soon as possible.

On July 12, Sweden Ericsson issued an announcement saying that it would join hands with France and Thaletz and Qualcomm of the United States to jointly develop new satellites that support 5G NTN services. At present, they have not announced the specific timetable for launching satellites, but these giants join forces, I believe that this service will inevitably advance this service. These three companies are very active in the standard formulation of 3GPP organizations. Tyrez is also a leading company in the NTN functional group. Therefore, their technology will inevitably meet the 5G NTN standard of 3GPP, but only SMS services can be provided in the early stage.

The old satellite communications company, Xingxing Communication, said on July 26 that it has signed a development agreement with a customer company with an unknown name, which will provide the company with new satellites that can provide hundreds of millions of mobile phones worldwide with narrow belt communication services ( Obviously, consumers do not need to change their mobile phones). The Xingxing Company did not disclose the technical details of the new satellite, but industry analysts believe that if it is compatible with the current billions of mobile phones, the new satellite must support the 3GPP 5G NTN standard.

The art imagination of the next -generation constellation

In February of this year, Globalstar said that it has signed an agreement with a customer company that has not disclosed the name, which will develop and launch 17 satellites to provide "continuous satellite services". According to industry speculation, this customer is Apple Apple company. According to the industry, Apple's iPhone14 mobile phone will be released in September this year, and it may support the service to send short messages through satellites. It is unclear whether this service meets the 3GPP 5G NTN standard, but we only need to wait for more than a month. American start -up satellite company Ast Spacemobile showed test satellites that can provide broadband services directly to mobile phones earlier this year. The main innovation of this company is that satellites use a foldable giant phase control array antenna, which can provide greater transmitting power and higher receiving gain, so that the rate of satellite and mobile phone communication directly increases to the level of broadband levels. It can truly realize the vibrato and WeChat on the ground anytime, anywhere, and the voice call is not a problem. Since the current 5G NTN standards of 3GPP have not yet involved broadband communication, it is certain that the satellite of Ast SpaceMobile does not meet the 3GPP standard, but maybe the company will participate in the standardization of 3GPP in the future.

"Blue Walker 3" prototype satellite of AST Spacemobile Company in the United States

Another American startup Lynk Global also provides mobile broadband satellite services. In February 2020, in the test of NASA and several mobile network operators, the company's experimental satellite achieved "the world's first text message from the orbiting satellite to the ground standard mobile phone. The company launched a new generation of test satellites in June 2021, which can provide greater transmitting power and achieve higher communication rates. It is certain that the company's early test satellite supports 5GNTN standards, but future broadband service satellites are not necessarily. It is unclear what technology the company provides broadband services, but in terms of communication principles, it is nothing more than using larger aperture antennas to launch with larger power. To achieve a larger aperture antenna, you can use a single giant antenna, or you can work together with a small antenna of multiple satellites to form a synthetic aperture antenna.

Lynk Global's future satellite mobile communication network concept map

Lynk Global's first text message from the world from satellites to "unmodified mobile phones" sent by Lynk Global

New technologies and new services, how can SpaceX be absent? On July 25, SpaceX applied to the Federal Communications Commission to use the 2GHz frequency band to enhance its mobile satellite services. According to SpaceX, the future star chain satellite will add a modularized effective load. Using a 2GHz frequency band will use "existing ground equipment and user terminals" and "will also add new earth station equipment to optimize consumers' which Performance. "The industry speculates that this service may be compatible with the NTN standard of 3GPP to provide SMS services for mobile phones. If the mobile phone uses" new ground equipment ", it can provide broadband services.

It can be seen from these news that foreign companies have been working in the field of direct satellite communications in mobile phones. What about Chinese companies? In fact, several companies in China have launched and verified IoT satellites and related technologies. The energy consumption of the ground terminals of some satellite systems has also been reduced to a hundred thousand watts. It has achieved technical compatibility with 3GPP NTN standards. There are no technical obstacles. We look forward to that more Chinese companies can quickly respond to join the competition of this new track.

Reference materials: