# The Framework of 6G Self-Evolving Networks and the Decision-Making Scheme for Massive IoT
## 1 Introduction  
The amount of connecting devices will reach 50 billion by 2030 [1], and all the devices will generate huge data traffic, which will transform the IoT into the massive IoT. The use cases of massive IoT consist of the smart city, digital agriculture, smart traffic, etc. To fulfill the constantly changing requirements of the services in different massive IoT applications, the networks are expected to be deeply integrated with AI to autonomously adjust the network configuration, architecture, resources, and other parameters according to the different scenarios, which are beyond the abilities of 5G networks. Moreover, 6G networks are expected to have endogenous intelligence, which can well support the massive IoT application scenarios. The autonomous decision-making schemes in 6G networks are expected to support the constantly changing service requirements and meet the requirements of the low latency in massive IoT. Actually, the 6G system is expected to utilize the full spectrum, face all scenarios, and support all applications [2]. Utilizing the full spectrum means that all of the frequency bands including sub-6G, millimeter wave, terahertz, and visible light communication will be utilized in the 6G system; facing all scenarios means the 6G network will offer coverage in the air, sky, ground, and sea; and supporting full applications means the 6G network will support all the new emerging technologies including AI, machine learning (ML), big data technology, etc. In addition, 6G will offer ultra-high data rates, ultra-highuser experience rates, ultra-low latency, and so on. Compared to eight representative key performance indicators (KPIs) of 5G defined by the International Telecommunication Union (ITU) [3], 6G is expected to satisfy higher requirements. According to [4], the peak data rate of 6G is expected to reach 1 Tbps. The user experience data rate is expected to reach 10-100 Gbps. The energy efficiency (EE) and spectrum efficiency (SE) are expected to respectively reach 10-1000 times and 3-5 times compared to 5G. Furthermore, 6G is expected to provide 0.1 ms over-the-air latency, enable high mobility up to 500 km/h, and support a connection density of up to 10\({}^{7}\) devices/km\({}^{2}\). In addition to the above traditional KPIs, some new KPIs will appear in the 6G era, such as computing power for compute first networking (CFN), security level for deterministic networks [5], and intelligence level for intelligent networking, which are to be defined in follow-up research. For clarity, we give the quantitative comparison of the KPIs between 5G and 6G. In some of the massive IoT applications such as super-smart vehicles and extended reality (XR), the service requirements are constantly changing, and it is of crucial importance to achieve low latency. Traditional methods of manually configuring the network will cause the large delay and extremely high complexity. On the other hand, driven by the rapid development of mobile Internet, big data, super-computing, sensor networks, brain science, and other fields as well as the strong demands of economic and social development, AI technology is also accelerating its development [6]. Moreover, a consensus has been reached by the industry and academia that 6G networks are expected to have endogenous intelligence. In short, the 6G network with endogenous intelligence will be suited for massive IoT. In fact, network intelligence is not a new concept. In the 4G era, a self-organizing network (SON) was proposed to realize the partial network intelligence [7]. By means of self-configuration, self-healing, and self-optimizing, SON reduced the operator resource expenditure and operating expenditure to a certain extent. Additionally, research on network intelligence has been gradually developed in the 5G era because of the higher and higher service requirements and the increasingly complex networks. The integration of AI and mobile communication wireless technology is one of the main research directions in the field in the 5G system.