In order to improve the management of the power consumption of electronic devices (such as cellular telephones), the operating mode of an interface circuit in an electronic device may be changed when certain commands are received. In particular, when one or more commands are received that disable data communication via the interface circuit and a cellular-telephone network and/or enable communication via another interface circuit in the electronic device and a wireless local area network (WLAN), the interface circuit may be transitioned to an operating mode in which data communication via the cellular-telephone network using a communication protocol that supports only data and no voice is disabled. For example, the communication protocol may include a Long Term Evolution (LTE)-compatible communication protocol.