According to a second aspect of the embodiments of this application, an apparatus for performing a communication service by using a plurality of modems is provided, and the apparatus may include a first modem MODEM 1, a second modem MODEM 2, and an arbitration apparatus. The MODEM 1 is configured to: perform a first communication service in a first frequency band; receive, from an access network device, a switching instruction for the first communication service, where the switching instruction is used to instruct the MODEM 1 to switch from the first frequency band to a third frequency band; and indicate to the arbitration apparatus that the MODEM 1 needs to be switched to the third frequency band. The MODEM 2 is configured to perform a second communication service in a second frequency band, where the MODEM 1 and the MODEM 2 are in a first operating mode. The arbitration apparatus is configured to: determine whether the third frequency band conflicts with the second frequency band, to obtain a determining result; and perform one of following operations based on the determining result: maintaining the first operating mode, or switching the first operating mode to a second operating mode for the MODEM 1 and the MODEM 2, where one of the first operating mode and the second operating mode is a concurrent operating mode, and the other is a non-concurrent operating mode.

Optionally, in some embodiments of this application, the first operating mode is the concurrent operating mode, and the second operating mode is the non-concurrent operating mode. The arbitration apparatus is configured to: when the determining result is that the third frequency band does not conflict with the second frequency band, maintain the first operating mode.