布局和简单，节点数目少，设备成本低，而且功耗低，控制集中，便于维护和管

The layout is simple, the number of nodes is small, the equipment cost is low, and the power consumption is low, and the control is centralized, which is convenient for maintenance and management. However, when a large amount of data is transmitted at the same time, the central node will be overloaded and cannot handle all of it, which will cause the network to freeze and the transmission of data to be lost.

Layout and simplicity, small number of nodes, low equipment costs, low power consumption, centralized control, easy to maintain and manage. However, when a large amount of data comes at the same time, the central node will be overloaded, can not be processed in full, resulting in network cataton, transmission data loss.

The layout is simple, the number of nodes is small, the cost of equipment is low, the power consumption is low, the control is centralized, and it is easy to maintain and manage. However, when a large amount of data is transmitted at the same time, the central node will be overloaded and can not process all of them, resulting in network stuck and data loss.