What exactly is "networkless communication"?

The recent month has seen a wave of launches in the smartphone market.

In addition to MediaTek and Qualcomm successively releasing flagship SoC chips, mobile phone manufacturers, including vivo, OPPO, Honor, Xiaomi, etc., have also released new flagship mobile phone products.

At the press conference, manufacturers presented a dazzling variety of parameters and concepts. Among them, there is a term that has successfully attracted the attention of Xiao Zaojun, that is, - no network communication.

According to the manufacturer's introduction, based on this networkless communication technology, voice communication of up to several kilometers can be achieved without a network, which is very sharp.

So, what kind of communication is networkless communication? How does it work? What are the use cases?

Next, Xiao Zaojun will talk to you about this topic.

█ What is networkless communication?
Networkless communication refers to communication that does not depend on external networks. That is, point-to-point communication between two devices in the absence of a third-party device (base station or wireless router, etc.) to provide the network.

Everyone must have thought of two technologies, one is walkie-talkie and the other is Bluetooth.

That's right, both of them are theoretically network-free communications.

What is the difference between networkless and networked communication?

Internet communication is the most commonly used communication method for us at present. Its advantages lie in its large communication range, high bandwidth, and large number of users.

Network communication has an advantage in power.

For example, mobile communication base stations have greater radio frequency transmission power, which can cover a longer distance (hundreds of meters ~ more than ten kilometers) and access more devices. Wireless routers, the power will be much smaller, but they can also cover a long distance (100 meters).

Whereas, end devices, such as mobile phones, have stricter limits on RF power. Therefore, the communication distance that can be achieved by direct communication between devices is very limited.

There is another advantage of network communication, that is, frequency band.

Mobile phones and base stations are used to communicate, and they are all legal communication frequency bands issued by the state to operators, which are high-quality and exclusive frequency band resources.

Wireless LAN communication (Wi-Fi) uses the unlicensed frequency band (ISM frequency band, which can also be called free frequency band) designated by the state. Everyone can use it, so it's very crowded. This also affects the communication distance and effectiveness.

Wireless walkie-talkies, some are private network communication (public security, fire protection, military and other units are dedicated, using specially allocated frequency bands), and some are shared by the public (hotels, security guards, etc.). Shared frequency bands are also congested.

Bluetooth, which uses the same license-free frequency band as Wi-Fi, is public and congested.

All in all, in terms of network capabilities, network communication (mainly referring to cellular mobile communication) has an absolute advantage. In addition, networked communication is very suitable for centralized networking, which can allow a large number of terminals to quickly access Internet nodes (data center servers), which is suitable for Internet business scenarios. Therefore, it has become the most mainstream means of communication now.

█ Advantages and use scenarios of networkless communication
So, with "networked" communication, why do we need to engage in networkless communication?

Because networkless communication has the following advantages:

1. Network-free communication is simple, flexible and convenient. As long as the two terminals are close to each other, they can communicate point-to-point, without networking, and are decentralized, which can meet the most basic communication needs.
2. In the absence of third-party network equipment (remote areas or disasters), communication can also be realized without network communication.
3. It does not consume mobile phone traffic, and the cost is low.
4. It is not connected to the public network, which has better privacy.

Everyone must understand that networkless communication is not intended to replace networked communication, but is used as a supplementary means in specific scenarios.

What are the specific scenarios?

We can give a few examples:

1. There is no base station signal in the underground garage. With networkless communication, you can contact a friend or find your car.
2. Outdoor adventures in deserts, forests, snow-capped mountains and other areas. There is no base station signal, and through network-free communication, the basic communication needs between teammates can be met. (Satellite communications are more expensive and are suitable for communication between the expedition and the outside world, such as calling for help.) ）
3. In the event of an earthquake and other natural disasters, all base station signals are interrupted. With networkless communication, it can help with rescue. (Satellite communications are not available when people are buried or trapped, while unconnected communications can call rescuers in close proximity.) ）
4. When traveling abroad, you can keep in touch with your relatives and friends without generating roaming traffic or phone bills through no network communication.
5. Realize regional socialization, so that users in a certain area can establish social networks. Intercom-style calls also increase playability.

█ Recent trends and implications for networkless communications
Networkless communication is a concept that has only emerged in the past two years, and no one has mentioned it before.

The two major technologies of walkie-talkie and Bluetooth mentioned earlier. Walkie-talkies have always existed because they are cheap and convenient, and they are Push to talk. Bluetooth, mainly used in headphones, keyboards, wearables, smart homes and other devices, has become a standard because of low power consumption, low cost, simple and easy to use.

Now, there are many reasons why mobile phone manufacturers focus on networkless communication.

First of all, it is the involution of the market.

Under the fierce competition, screens, cameras, SoC chips ...... Everything that can be rolled has been rolled, so it is necessary to create some differentiated advantages and find new "roll points".

Secondly, there is the demand for the scene.

There are indeed some demand scenarios for short- and medium-distance point-to-point communication, such as those mentioned earlier, and these scenarios are becoming more and more common. Under the goal of ubiquitous communication, the development of this function also has a certain necessity and practical value.

Third, technological exploration.

This is actually the most important thing. Traditional Bluetooth technology has not had a major breakthrough for a long time, and it cannot well meet the needs of user scenarios in terms of communication distance, bandwidth, and power consumption.

You should find that in recent years, terminal manufacturers have not only increased their participation and investment in global public technical standards, but also increased the development of private protocols.

Network communications, such as 5G and Wi-Fi, are based on public standard protocols, which are conducive to the unification of the industrial chain, but the standards are in the hands of a few large enterprises (mainly operators and equipment vendors), and terminal manufacturers lack the right to speak. A standard protocol like Bluetooth has many aspects to take into account, involving too many interests, and it cannot be said to be moved.

Then, terminal manufacturers can only make a fuss about private protocols.

The most typical example is not a mobile phone, but a DJI drone.

DJI drones carry out remote control, and the communication between the control terminal (handle) and the drone is point-to-point communication, network-free communication. Because traditional technology simply cannot meet the needs of remote control and video transmission, DJI chose to develop its own proprietary protocol, which can extend the control distance to an astonishing 10 kilometers or more.

This year, DJI released the new DJI SDR video transmission, which is based on Software-Defined Radio (SDR) technology and adopts SDR and Wi-Fi dual-standard video transmission technology, supporting 1080p / 60fps transmission specifications, transmission bit rate up to 20Mbps, latency as low as 35ms, and video transmission distance of up to 3km.

On the side of mobile terminals, the development of private protocols is to make up for the shortcomings of existing technologies on the one hand, and to serve the interconnection between their own products on the other hand.

As you may have thought, mobile phone manufacturers now usually launch mobile phones, pads, laptops, watches, etc. Then, the linkage and screen projection between these devices can also be based on private protocols.

Traditional technologies, especially Bluetooth, do have a lot of room for improvement in technical performance. Earlier, I told you about Starlight. In terms of technical indicators, the Starlight standard is completely Wi-Fi and Bluetooth.

This shows that the existing mainstream technical standards are not perfect. The main reason why they cannot be replaced is that they have become an established global standard and are difficult to replace (requiring the support of all or most vendors).

Recently, mobile phone manufacturers have released networkless communications, in fact, they are essentially enhanced on the basis of Bluetooth, or have developed Bluetooth-like technologies. These technologies make use of the phone's existing radio hardware, and then employ special protocols and algorithms.

vivo's networkless communication technology is mainly based on Bluetooth and LoRa spread spectrum technology. The vivo X200 series of mobile phones can achieve up to 1500 meters of network-free communication. This technology can support SOS text broadcasting, one-to-one voice and text intercom, map location display, and more.

OPPO's networkless communication technology is called MeshTalk. Text, voice transmission, and even voice calls within 3,000 meters can be achieved without cellular, Wi-Fi, and Bluetooth. MeshTalk can even support multiple devices to freely network in the form of mesh to achieve multi-group chat.

Xiaomi's just-released Xingchen communication system supports "the industry's first kilometer-level network-free call", within a radius of 3.5km, two-way communication can be made without a network. It is understood that Xiaomi's networkless communication also supports mesh networking.

These networkless communication technologies are self-developed private protocols, which can only be supported under the same brand terminals, and only some terminals currently support them.

█ Final words
All in all, the development of private protocols to further improve the communication capabilities of terminals and meet the user experience in special scenarios has become a common choice for vendors. The global unified standard protocol has shortcomings in flexibility and customization, which provides some room for the development of private protocols.

It remains to be seen whether this trend will continue to expand and whether new vendors or technology alliances will emerge.