Most of the existing LBS services are based on outdoor environments. As people's production and life in modern society are increasingly concentrated in indoor environments, location information services based on indoor positioning have huge user demands. This also puts forward higher requirements for the development of Indoor Position System (IPS). For example, anti-theft measures in large venues, indoor shopping guides in shopping malls, anti-lost prevention for the elderly and children, real-time human resource management of enterprises and companies, and the connection of online transactions and offline services will all rely on the development of timely and accurate indoor positioning systems. Provide corresponding timely information services