The invention provides an asymmetric seamless switching method for large and small base stations and is applicable to the large and small
base station mode of a
broadband wireless multimedia system. Cells of a plurality of
small cell base stations are simultaneously in the
service coverage of a large broadcast
base station; when the point-to-multipoint mode of large broadcast
base station fails to assure the required
service quality of a
broadcast service, the large broadcast base
station needs to be seamlessly switched to the small
station of the cells so as to provide the
broadcasting service in a point-to-point mode; once that the
service quality of
broadcasting service provided by the large base
station for the user in the point-to-point mode restores to be normal is monitored, the small base station is switched to the large station immediately; and the continuity of
service quality of
broadcasting service can be guaranteed, and the use ratio of
wireless resources can be improved. The seamless switching method provided by the invention is an asymmetric switching method. The large broadcast base station is switched to the
small cell base station by a pretrigger method with switching
delay taken into consideration, and the switch from the
small cell base station to the large broadcast base station is judged according to the switch threshold of service quality of the broadcasting service. By taking the influence of switching
delay and ping-pong effect into comprehensive consideration, the
system resource utilization rate of large and small base station mode can be optimized under the condition of meeting the service quality requirements of broadcasting service.