## 2 Related Work  
Since the advent of the shared bicycle, many scholars around the world have been studying relevant questions. The authors in [5] suggested the IoSB concept, which includes the perception, communication, application and safety layers, and showed five-layer model IoSB architecture. In IoSB, the transition from the original pile-shared bicycle to the current pile-less sharing bicycle has many problems to overcome, such as environmental information collection, node location, low power communication technology, bicycle dispatching scheme, path management, etc. IoSB is essentially a type of Wireless Sensor Networks (WSNs), and its information collection has long been related to research. In [8], [PERSON] et al. proposed a type of low-latency data gathering method with multi-sink in WSNs. Network division, multi-sink, efficient sleep scheduling and the sensing radius adjustment strategies are utilized to reduce the redundancy in network coverage and further improve the energy efficient. With its advantages of low energy consumption, node positioning technology in the WSN network also has certain reference significance for IoSB. In [9], a type of energy-efficient target tracking approach based on grids in WSNs was proposed. The concept of virtual grids and its three kinds of states including tracking state, prepared-tracking state, and preparing-tracking state were defined to reduce energy consumption and enhance the accuracy of node localization. Reliable data transmission is an important guarantee for data-based applications, especially real-time ones such as a shared bicycle. Communication efficiency is determined by the technical norm, network topology, base station antenna sensitivity, etc. Here, are some of the communications technologies that are commonly used in mobile networks, like the shared bicycle. LTE is the technical standard that all existing smartphones adopt, enabling data terminals to have a faster speed of network transmission which is ubiquitous and suitable for wide-range, high-bandwidth applications like IoSB [10]. However, its modules' cost and energy consumption are too high to be applied in IoSB. The Low-Power Wide-Area Network (LPWA) has strong penetration and is designed for applications in complex urban environments with long communication distances [11]. Compared to existing LTE networks, NB-IoT, as a kind of LPWA technique, has the advantages of wide coverage, low power consumption, low module costs, and a large connection [12], and has been used in applications such as water quality monitoring [13], smart parking [14], smart hospital [15], and shared bicycles. Shared bicycle dispatching is crucial to rebalancing bicycles and can be separated into static dispatch and dynamic dispatching. Static dispatching is to research the cumulative mutual bicycle dispatch distance as a measure of optimization. In comparison, dynamic dispatching is based on operator revenue or user riding satisfaction optimization. The dispatching route problem between static leasing sites, which belongs to static dispatching, is studied in [16]. In conclusion, the problem of shared bicycles' static dispatching can be considered as a problem of path optimization, which can generally be modeled using linear integer programming [17; 18; 19] and found using heuristic algorithms such as Genetic Algorithm (GA) [20], Particle Swarm Optimization (PSO) [21], Ant Colony Optimization (ACO) [22], Simulated Annealing Algorithm (SAA) [23], and so on. Dynamic dispatching pays more attention to the current state or possible future state of the dispatching area and the surrounding region compared with static dispatching and then makes better, more effective and far-sighted scheduling decisions based on the current time and future state data on the map. There are a lot of cases on the demand forecasting of the shared bicycle. For example, in [24], the author proposed a moment-based hybrid prediction method.