The transmission of information has been started since the beginning of humankind. The transmission of information was initially through the babbling between people, the reception and processing of information by the eyes, ears and tongue, the information about food and survival was spread, and civilization began to continue after that. The spread of images and language has accelerated human co-evolution, and human footprints have embarked on a broader territory.
More than two hundred years ago, human brain power suddenly evolved, and technological civilization suddenly exploded. The information dissemination and upgrading process no longer relied on thousands of years of footsteps, vision and hearing, but was dominated by invisible signal waves. From Morse's invention of wired telegraphy in 1838, to AM radio broadcasting in 1918, to today, we cannot see the spread of information with the naked eye, but information flows in every corner of the world, covering economy, production, life and other aspects. Domain, breaking down the barriers of geographical, space and other restrictions, affecting everything.
In the intelligent era, information networks have become very complex. The overall information system involves information storage and calculation. The signal transmission rate will be affected by the channel width, noise size and signal power. There are limits, which brings difficulties to the transmission of information. This It also means that the overall optimality needs to be explored from a system perspective.
The foundation of information theory - Shannon information theory builds the foundation of the modern information building and establishes a basic theoretical system for information measurement, compression, and transmission. At the same time, it also proposes solutions from the semantic level to the limits of communication transmission. So based on semantic changes, how will communication technology develop in the post-Shannon era?
The "limit" of communication transmission
In 1948, a great communication theory was born in the field of information communication - the famous Shannon theorem: there is a theoretical limit value in communication channel capacity, which represents the ultimate information transmission rate and channel capacity in the channel, and is regarded as the basis of modern communication. "The Golden Rule." Since then, Shannon's theorem has become the basic theory of modern information theory. The information industry has developed rapidly and is widely used in the fields of communications and data storage. Based on Shannon's theorem more than 70 years ago, generations of communications products have continued to emerge, and have laid the foundation for today's communications. Development has laid a solid theoretical foundation.
Entering the era of digital intelligence, we have entered an intelligent society where everything is aware and interconnected. New production and life models are also constantly emerging. These are fundamental changes from the Shannon era 70 years ago. With the rapid development of 5G technology, it has almost reached the limit of Shannon's theorem. Many communication experts in the industry also stated that "there will be no G after 5G" and that point-to-point channel capacity has approached the capacity limit. In the future development of communication technology, all that remains will be the expansion of the number of communication channels.
The development of the communications industry has reached a stage where it needs to face challenges head-on. At the Mobile World Congress, Huawei's rotating chairman Guo Ping pointed out: "Shannon's theorem and von Neumann architecture have encountered great bottlenecks, and we need to explore new theories and architectures."
The bottlenecks of Shannon limit and von Neumann architecture also extend the direction of the evolution of computing and communication in the direction of quantum computing, DNA storage, and semantic communication. Semantic communication is used to solve problems such as storage and efficiency of information transmission, and the characteristics of quantum computing are used to execute huge computing tasks in parallel.
Exploring these new information transmission and processing modes can extend information transmission to wider unknown areas, such as deep sea communication, deep space communication, human body network and molecular network, etc. These research directions provide new space for growth and innovation in the future.
Multi-agent ubiquitous connection
To explore and solve the semantic communication problem in Shannon limit, we need to answer the basic connotation and core essence of semantic communication. The concept of semantic communication was first proposed by Weaver and Shannon in their classic paper published in 1948. Semantic communication is communication oriented to signal semantics. Its essence is to transmit information expressed by semantic symbols. These symbols can allow the recipient to understand it instantly. meaning.
The purpose of communication between humans is to express ideas. Every word we say through voice communication is not only for the other party to hear but also to understand. In the transmission of modern information, current communication technology is the transportation of information signals rather than the transmission of information. The transmission of information is mainly based on the principle of signal waveform or data bit fidelity, leaving the task of extracting and understanding the information in the signal to the people themselves. There is a cost to move from signal transmission to information understanding. For the transmission of a large number of signals, transmission efficiency and communication methods for directly understanding information need to be reconstructed and reformed.
The signal receivers of semantic communication rely on their local semantic knowledge base to transmit a very small amount of content and encode and decode it separately to achieve accurate and rapid transmission of a large amount of information. Similar to the black technology transmission form in science fiction dramas and spy war dramas, the transmission of information can be completed with a very small amount of content, which not only reduces the time for information transmission and understanding, but also ensures real-time and fidelity communication quality.
Semantic communication is a deepening of the essence of communication. When information theorist Weaver proposed this future concept that was ahead of its time, due to technical limitations, early communication equipment was just a signal conversion machine and did not have the ability to be intelligent and unable to express and understand semantics. With the continuous development of 5G+AI technology and the advancement of intelligence in communication equipment, the communication model has undergone new changes, which has also given the research and development of semantic transmission a soil and carrier to grow, and a new type of task-oriented multi-agent The communication model makes it possible to communicate and collaborate.
For semantic communication, the core is the semantic knowledge base, which is the cornerstone of communication between the two parties. The semantic knowledge base is based on universal knowledge and semantic systems. It can break the incompatibility problems caused by inconsistent information modalities in the current M2M intelligent connection. It can also ensure the service experience during H2M and H2H intelligent connection interaction and communication, and reduce semantic and physical problems. The number of conversions between signals reduces possible semantic distortion. Industry insiders also regard semantic communication as a true artificial intelligence communication method. It can meet the needs of ubiquitous interconnection between intelligent agents.
In the communications industry, semantic communication has also begun to be valued, and communications giants and large companies have begun to explore basic theories. Following the pace of these pioneers, we will also see the real-time normal use of AR and VR in the future, and the transmission of information between a large number of agents will be faster and more accurate.
The ultimate communication model
As a new communication technology in the intelligent era, semantic communication will have broad prospects in the future in smart facilities, multi-agent collaboration, natural human-machine interaction, human-machine fusion, and urban collaborative security. However, although semantic communication has great potential and value, it is difficult to have both cake and eat it, and its development still faces challenges.
1. Semantic knowledge base is difficult to share. The semantic knowledge base is the cornerstone of semantic transmission. Participants in communication need to share the same or similar philosophical worldview and knowledge model. Knowledge accumulation and data collection require continuous investment, which will consume a lot of time and cost. In the transmission of some unknown semantic knowledge, there are also higher requirements for the collaborative update capabilities of the knowledge bases of both parties. Otherwise, in some situations where the knowledge bases of the transmitter and the receiver are inconsistent, the shared knowledge of both parties is inconsistent, and the transmitted information cannot be maintained. For some equipment and machines with short lifespans, maintaining and updating the knowledge base also requires huge communication and storage costs.
2. The limitation of semantic communication technology itself is that the semantic context is difficult to perceive and identify. Semantic signals contain information that is all-encompassing and rich in content. It is easy to be restricted by various regions, backgrounds, classes, environments, etc. For example, people in the communications industry will be more sensitive to professional knowledge in the communications field, and those who are good at autonomous driving will pay more attention to autonomous driving information. The transfer of semantic information content will easily be limited to the context of both ends of the information transmission. It will be more difficult for knowledge recognition and processing.
3. The transmission of information involves conflicts of privacy and security. The two parties in the information transmission are constantly exchanging the information they obtain. In the case of coordinating and updating the knowledge base, it may cause potential leakage risks of local knowledge/privacy data, making data privacy difficult to protect.
These difficulties are all obstacles in the development of semantic communication. Solving the bottleneck of Shannon limit depends on the breakthrough of these limitations. The model of semantic communication will change the communication function from mutual signaling to mutual communication. The intelligent model of human-machine collaboration and human-machine hybrid will also rise to a new dimension. This also promotes efficient cooperation between agents to solve more complex, open, and robust problems.
Communication is the foundation for the development of various industries in modern science and technology. The transformation of semantic communication will also lead communication technology-related industries to a new stage. From the architecture of the communication network to the core neural network chip, including various communication interface specifications and standards, etc., they will all change with the emergence of the semantic communication model.
These changes will also affect changes in interfaces and equipment standards in various industries. There may be a scenario in the future where newly purchased products can be communicated directly with people, without the need for paper instructions or video versions. Communication with users has become the most convenient and fastest trend. Users no longer need to learn the process of using the product. Machine language for communication between agents will also be born, collaborative understanding of multi-agents will also become a reality, and the efficiency of human-machine collaboration and machine-machine collaboration will be greatly improved.
In the past, the transmission of information focused on reproduction and speed. However, with the extreme development of technology, the ultimate pursuit of the communication industry is to move from speed to understanding. People are simplified and liberated from the steps of analyzing and processing information. The efficiency of information transmission is based on content. The perspective is fully dimensioned.
In science fiction, the ultimate mode of communication is telepathy. Through some smart devices, as long as both parties want to transmit information, the information will be transmitted telepathically. There will be no misunderstandings and distortions. There is no time limit on the efficiency of information transmission, and it can be completed immediately. People can be liberated from inefficient information dissemination and develop their knowledge in an all-round way. Complete telepathy in science fiction works is difficult to achieve, but if you look closely at its essence, telepathy and semantic communication are similar in nature. They both pursue information fidelity and efficiency. In other words, semantic communication is also a low-level telepathy method. . Once mature, the liberated efficiency and smoothed information barriers will bring us unlimited future.
