What are the intelligent building companies?

Building intelligent engineering includes many subsystems, and there are about 2 simple statistics, and any company involved in several subsystems can belong to a building intelligent company. Therefore, it is difficult to answer with the names of several companies. Moreover, building intelligent companies are involved in the construction industry, and most companies rarely develop business across provinces and cities. I have heard of China Electronics, Beijing Taiji, Changjiang Computer, Huadong Computer and Tsinghua Tongfang. In foreign-funded enterprises, there are also departments (branches) under Honeywell, Johnson and Schneider that are responsible for this business.