Recently, both domestic and international regions have experienced extreme weather disasters such as earthquakes, rainstorms, floods, and typhoons, causing severe economic losses and casualties.
According to assessments by meteorological agencies from multiple countries, this year is highly likely to be a "Super El Niño year." Under the combined effects of this climate phenomenon and global warming, more extreme weather events are expected to occur worldwide. The tests we face have just begun.
Natural disasters are natural phenomena that operate independently of human will. If we cannot prevent them, then early warning and timely rescue after a disaster occurs are the most effective means to minimize losses.
Emergency communication is precisely the foundation of all these actions.
What exactly are our emergency communication methods? And what new changes and trends are emerging in emergency communication technology?
Today, Xiaozaojun will discuss this topic.
█ What Is Emergency Communication According to the official authoritative definition, emergency communication refers to a temporary, special communication mechanism. It comprehensively leverages diverse communication resources to overcome limits of conventional networks and satisfy demands for emergency command, disaster rescue, and public distress calls. It activates during natural or man-made sudden emergencies, or special periods including major holidays, key conferences and large-scale events.
In other words, daily civilian communication mainly focuses on normalized, mass-market, and entertainment-oriented needs, pursuing network speed, bandwidth, and user experience.
Emergency communication, however, takes "ensuring connectivity, ensuring command, and ensuring rescue" as its sole core objective. It prioritizes core rigid demands such as life rescue, government command, and disaster reporting, discarding redundant functions and focusing on enhancing adaptability in extreme environments.
In scenarios where public networks are completely paralyzed, the environment is extremely harsh, and resources are severely scarce, emergency communication must provide the most basic communication support to save lives and minimize losses.
█ The Evolution of Emergency Communication Emergency communication is not a new concept. Its development is closely linked to the evolution of communication technologies.
In the early stages of humanity, without professional communication equipment and technologies, urgent information transmission relied entirely on manual and natural signals. Beacon fires, postal relays, drum warnings, and flag signals were the most primitive forms of emergency communication.
These communication methods had short transmission distances, low information capacity, and high error rates. They could only achieve the simplest "warnings" and could not support refined rescue operations, making their role very limited. However, their emergence established the core logic of "priority transmission of urgent information" in emergency communication and laid the foundation for subsequent technological evolution.
In modern times, the advent of wired telegraphs and telephones brought a leapfrog upgrade to human communication technology.
Wired telegraph and telephone technologies had significant advantages in the immediacy of information transmission and communication distance, greatly improving the efficiency of emergency communication. However, they still had shortcomings—because they relied on wired media, they were highly vulnerable to damage from disasters like earthquakes and floods, leading to destruction, breakage, and subsequent communication interruptions, resulting in extremely poor reliability.
Later, the birth of wireless communication technology completely changed this situation.
Wireless communication does not rely on wired media; it transmits information via radio waves, significantly enhancing survivability and mobility. There was also a qualitative leap in transmission distance. These characteristics are highly suitable for emergency communication scenarios.
In fact, the earliest applications after the birth of wireless communication were in maritime and military fields. In the early 20th century, maritime disasters were frequent, and wireless telegraphy saved many lives. The famous Titanic, for instance, was able to save over 700 people and avoid greater losses precisely because it sent out distress signals via wireless telegraphy.
In the 1930s, the world's earliest wireless intercom technology emerged, bringing wireless communication into the voice era. This technology was first adopted by police, fire departments, and other agencies, gradually becoming the main equipment for emergency rescue.
By the 1960s and 1970s, various developed economies began to establish modern emergency management systems, improving their ability to respond to emergencies, including natural disasters, from multiple perspectives such as institutions, processes, funding, and technology.
During that period, technological development was advancing by leaps and bounds. Technologies such as microwave communication, satellite communication, and wireless intercom communication rose rapidly, providing humanity with more efficient and flexible emergency communication means.
In the 1970s and 1980s, based on early walkie-talkies, analog trunking and digital trunking technologies were developed, forming technical standards such as iDEN and TETRA. The emergency communication wireless private networks in many countries were built based on these technologies. Wireless trunking technology played an important role in some natural disasters and major events.
In the late 1990s, our country also researched and introduced these technologies, gradually forming its own wireless private network technical standard route (such as PDT).
Entering the 21st century, human emergency communication technology has made significant progress.
Satellite communication and trunking communication have gradually become mainstream emergency communication methods, providing necessary guarantees and support for emergency rescue, command, and dispatch in major natural disasters, important public events, and large-scale gatherings.
In 2008, the Wenchuan "5·12" earthquake occurred, causing enormous loss of life and property. Our emergency communication management system and technology played a significant role in this earthquake, but also exposed many problems.
Relevant government departments paid higher attention to these problems and promoted institutional improvement and technological upgrades.
Before 2008, emergency communication support mainly focused on guaranteeing sudden capacity demands in urban hotspot areas. The means of emergency communication support were primarily emergency communication base station vehicles and trunking communication, with a small amount of satellite communication.
After the Wenchuan earthquake, satellite communication performed outstandingly during the disaster relief process and gradually received more attention. Governments at all levels and operators began to actively introduce satellite phones, satellite emergency communication vehicles, VSAT fixed stations, and other equipment to increase the proportion of satellite communication in the emergency communication technology system.
Besides satellites, with the continuous evolution of mobile communication technologies (3G/4G/5G), the communication industry also began to study how to leverage the role and value of these technologies in emergency communication scenarios.
█ Challenges and Responses in Contemporary Emergency Communication Today, the frequency of global natural disasters has increased, and major public safety incidents occur from time to time.
To minimize disaster losses and protect people's lives and property to the greatest extent possible, humanity has begun to re-examine the development path of emergency communication technology, exploring more technological innovations to empower disaster warning and post-disaster reconstruction with technology.
Disasters or emergencies have two prominent characteristics: uncertainty and complexity.
Uncertainty is reflected in time and location.
We do not know when or where a disaster will occur. Therefore, we need emergency communication methods to have sufficient mobility and flexibility, and emergency communication equipment must be easy to transport and rapidly deployable.
Complexity, on the other hand, is reflected in the on-site environment and demands.
Disasters can occur in mountains, deserts, rainforests, or even at sea. Current emergency communication needs include not only the distress calls of victims but also the coordination needs of rescue personnel, as well as management and dispatch requirements. Besides voice, there are now also demands for video and image communication.
Therefore, emergency communication methods require strong stability and anti-interference capabilities, need to provide diversified services, and must have stronger performance and larger capacity.
In recent years, innovations in emergency communication methods by the communication industry have mainly revolved around these specific needs.
Under the regulations of the ITU (International Telecommunication Union), countries around the world have successively formulated comprehensive "space-air-ground-sea integrated" emergency communication management systems and operational standard specifications.
Numerous advanced ICT technologies, including positioning and navigation (Global Navigation Satellite System, GNSS), the Internet, IoT (Internet of Things), mobile communication, satellite communication, cloud computing, big data, AI (Artificial Intelligence), and VR/AR, have been introduced into the field of emergency communication, jointly building an increasingly powerful emergency communication network.
Our country has also been continuously making efforts in the construction of the emergency communication system.
In December 2024, the Ministry of Industry and Information Technology (MIIT) and 13 other departments issued the "Opinions on Strengthening the Construction of Emergency Communication Capabilities in Extreme Scenarios," clearly stating the goal to build a national-level emergency communication framework of "public-private network coordination and space-air-ground-sea integration" by 2027. This marks that China's emergency communication system has entered a new stage of standardized, modernized, and intelligent upgrading.
In short, emergency communication at this stage is no longer a simple superposition of single devices and single networks, but a full-domain system integrating satellite communication, aerial relay, ground mobility, and maritime support.
A truly powerful and comprehensive emergency communication system must achieve integrated transmission of voice, video, data, and positioning; must possess cross-regional, cross-departmental, and cross-level collaborative dispatch capabilities; must be able to adapt to various complex scenarios such as extreme weather, major geological disasters, and large-scale emergencies; and must thoroughly solve the pain points of traditional communication, such as coverage limitations, weak survivability, and poor collaboration.
Multi-standard fusion, public-private network coordination, and the full introduction of cutting-edge technology have become the core directions for the construction of the emergency communication system.
█ Typical Technology Applications in Emergency Communication Next, let's take a look at which communication technologies are being applied in emergency communication scenarios and how exactly they play a key role in disaster relief work.
● Satellite Communication Satellite communication is one of the most critical means in emergency communication. When traditional terrestrial communication networks are damaged by disasters or suffer from insufficient coverage, satellite communication can provide wide-area, reliable communication links, providing basic guarantees for disaster relief work.
In recent years, satellite communication has developed rapidly. In particular, the rapid deployment of high-throughput satellites and low Earth orbit (LEO) satellite constellations has greatly enhanced broadband access capabilities in emergency scenarios, supporting high-traffic services such as high-definition video backhaul and real-time command dispatch.
In the early days, satellite communication mainly used VSAT (Very Small Aperture Terminal) systems to provide voice calls and narrowband data transmission services for disaster areas. These terminals were dedicated; although relatively compact in size, they still have a certain cost threshold and require professional training for use.
Later, dedicated satellite phones were introduced, further reducing size and cost. Many township-level governments can now be equipped with satellite phones to maintain contact with the outside world during extreme disasters.
In recent years, the maturation of Direct-to-Cell satellite technology has enabled ordinary smartphones to directly access satellite networks in areas without terrestrial signal coverage, sending short messages or making voice calls. This has greatly improved the response speed and coverage of satellite emergency communication.
For ordinary users, when trapped in a disaster, they can use the Direct-to-Cell feature to send distress messages and location coordinates, significantly increasing the chances of being discovered and located by rescue personnel.
● Nomadic Base Stations Mobile communication base stations are currently the most widely used and relied upon communication means by the public. However, during natural disasters such as earthquakes and floods, the power and transmission resources of traditional base stations are easily damaged, causing base stations to go out of service, which in turn leaves the local population without mobile signals.
When traditional base stations cannot work, using miniaturized and lightweight base stations for rapid service recovery is a necessary measure.
Nomadic base stations are a type of miniaturized, mobile base station highly suitable for emergency communication scenarios.
Nomadic base stations typically support multiple backhaul methods such as microwave and satellite. They adopt a small outdoor cabinet form factor, integrating retractable antenna masts, AC-to-DC converters, cooling systems, and batteries.
Nomadic base stations are compact and can be transported by light trucks. They are highly mobile and can be rapidly deployed in disaster areas to achieve network signal coverage.
Besides providing network coverage to the affected population, nomadic base stations also possess edge computing capabilities. They can build local computing private networks, helping rescue personnel and command centers share rescue images, videos, voice, and other information, greatly improving rescue efficiency.
● Emergency Communication Vehicles Emergency communication vehicles are also relatively common mobile base station equipment for emergency communication.
They feature high integration, equipped with generators, emergency base stations, satellite equipment, intercom systems, video transmission systems, and command dispatch systems. They are equivalent to a rapidly movable "micro communication command center."
The vast majority of emergency communication vehicles can supply their own power and form their own networks. Upon arriving in a disaster area, they can be deployed within 10 minutes to quickly restore regional voice, network, and video communication. They are adapted to major and extra-large disasters and large-scale communication paralysis scenarios, serving as the core mainstay equipment for emergency support.
● UAV Base Stations In recent years, UAV (Unmanned Aerial Vehicle) technology has developed rapidly. Based on its characteristics of low-altitude, low-speed flight, and hovering capability, the communication industry has also introduced it for emergency communication in disaster areas.
The industry mainly uses multi-axis, multi-rotor UAVs to suspend base stations for wireless signal coverage within a region. Limited by the UAV's endurance and signal backhaul, tethered UAVs were mainly used in the early stages, always having a "tail" (tether) at the bottom.
During the heavy rain disaster in Mentougou, Beijing in August 2023, and the heavy rain disaster in Zhengzhou in July 2021, more advanced large fixed-wing UAVs were used for emergency communication support, attracting widespread public attention.
There are many types of UAVs used for emergency communication. Generally, they feature multi-access methods, multi-task capabilities, wide environmental adaptability, large capacity, broad coverage, and long endurance.
When a disaster occurs, emergency communication UAVs can fly stably in designated areas, providing continuous mobile communication signal coverage for dozens of square kilometers for several hours, while simultaneously providing voice, SMS, and internet services for thousands of users.
● Robot Dogs Robot dogs, or quadruped robots, belong to a type of embodied intelligence.
In recent years, robot dogs have also been introduced into the field of emergency communication. They possess excellent terrain adaptability, capable of climbing ruins and stairs, and traversing narrow passages and complex terrains, executing tasks at disaster sites where traditional wheeled or tracked equipment cannot enter.
Robot dogs can carry lightweight base stations, satellite communication equipment, and environmental sensors, penetrating deep into extreme environments with no network, no power, and no roads.
On the one hand, they provide network coverage for disaster areas; on the other hand, they can establish temporary communication nodes, transmitting real-time on-site environmental data from the disaster area to the rear command center, providing critical information support for rescue decision-making.
● Private Network Communication Private network communication has always been an indispensable part of emergency communication support. In the past, private network communication involved setting up temporary communication antennas and nodes to establish a temporary small-area communication coverage network. Rescue personnel then used dedicated walkie-talkies for voice communication.
Today, private network communication is no longer limited to simple voice communication but is evolving towards broadband, intelligence, and multi-service fusion. Network capabilities are more powerful, and services are more diversified.
Private network communication also increasingly adopts technologies such as mesh networking to achieve self-organization, self-healing, and adaptive adjustment, greatly enhancing network reliability and coverage flexibility. The capacity of private network communication is continuously increasing, and its anti-interference capability is stronger, providing differentiated communication support services for different rescue teams.
● Fortress Base Stations Fortress base stations, sometimes called super base stations, are special base stations specifically designed and built by operators for extreme disaster scenarios.
Their design concept is "serve in peacetime, respond in emergencies, and fight in wartime." From the very beginning of construction, fortress base stations fully consider survivability in extreme environments, equipped with self-owned power supplies, satellite transmission links, and anti-destructive structures. They can continue to operate for several hours or even days when the municipal power is interrupted and transmission optical cables are damaged, ensuring that communication in the surrounding areas is not interrupted.
Various regions in China are actively promoting the construction and upgrading of fortress base stations, which are usually deployed in key areas such as government agencies, transportation hubs, and key hospitals. They will become the "ballast stone" in the emergency communication support system.
● Network-Free Communication In recent years, many terminal manufacturers have proposed the concept of "network-free communication."
Network-free communication refers to the ability to achieve point-to-point or networked communication over short distances using the capabilities of the terminal devices themselves, through communication technologies such as Bluetooth, Wi-Fi Direct, or proprietary protocols, without traditional communication infrastructure like base stations or satellites.
The communication distance of network-free communication usually ranges from several hundred meters to several kilometers. Although the coverage is limited, in extreme disaster scenarios, it can serve as the "last line of defense" for emergency communication, ensuring basic contact between affected personnel and rescue workers.
● Public Warning System (PWS) The technical means we mentioned earlier are mainly used for the reconstruction of communication systems after a disaster. In fact, disaster warning plays a greater role in reducing disaster losses.
Here, we must mention the Public Warning System (PWS), which has been very popular in recent years. The PWS system can send alert messages such as the Earthquake and Tsunami Warning System (ETWS) and the Commercial Mobile Alert System (CMAS).
When a user's mobile phone receives an alert message, it will automatically pop up the information and play a specific alert tone. Based on the alert, users can take timely shelter and self-rescue measures.
During several recent earthquakes in China, including the magnitude 4.5 earthquake in Deyang, Sichuan a few days ago, many users received relevant message prompts. The PWS system has received widespread attention and praise.
█ Challenges Faced by Emergency Communication Emergency communication is a complex and massive system engineering project. Relying solely on technological means is far from enough; it also requires the improvement of policies and regulations, the coordination of organizational mechanisms, and the enhancement of public emergency awareness.
Although our country has established a relatively comprehensive emergency communication system and played a key role in major natural disasters, we must clearly recognize that the current emergency communication system still faces many challenges.
For example, natural disasters usually occur in mountainous areas, forests, and remote villages. The coverage density of conventional base stations is low, infrastructure is weak, and terrain shielding is severe. Conventional communication signals attenuate quickly, and there are many blind spots. After extreme disasters, these areas are the first to lose network connection and the hardest to recover. Moreover, large mobile equipment is difficult to enter, making communication support extremely difficult.
Furthermore, many of our grassroots communication infrastructures still lack emergency spare parts and diesel generators. When a disaster occurs, personnel often have to carry heavy equipment over mountains and rivers to the site. This not only consumes a lot of manpower and material resources but also seriously affects the speed of emergency response.
There are also significant differences in emergency communication support capabilities across different regions. Regions with stronger economic strength are often equipped with basic emergency communication equipment. However, economically weaker regions are not. Even if equipped, there may be issues such as insufficient professional operational capabilities of grassroots staff and lack of equipment maintenance, leading to the inability to quickly activate equipment in sudden scenarios.
Emergency communication involves multiple departments such as emergency management, industry and information technology, meteorology, fire rescue, public security, water resources, and major operators. In some scenarios, there may be issues such as scattered communication resources, dispatch barriers, incompatible frequency bands, and unshared data. From the perspective of management and institutions, it is necessary to further optimize cross-regional and cross-departmental emergency communication linkage capabilities and improve the efficiency of multi-network integration and full-domain collaboration.
All these problems require time and resources to be gradually resolved and cannot be solved overnight.
█ Final Words Galileo said, "The true purpose of science is to relieve the sufferings of human existence."
From beacon fires to telegraphs and telephones, and then to satellites, 5G, and robot dogs, the technological evolution of emergency communication has faithfully adhered to this purpose.
Although natural disasters continue to occur, advanced technology and accumulated rich experience make us more composed and orderly when facing disasters, and the loss of life and property continues to decrease.
With the help of technology, we will ultimately achieve harmonious coexistence with nature and build an enduring and vibrant civilization.