Apparatuses, systems, and methods for using an assistance information framework to perform fast carrier aggregation and dual connectivity configuration. A wireless device may provide assistance information for determining a carrier aggregation or dual connectivity configuration to a cellular base station. The assistance information may be provided while establishing a radio resource control connection. The assistance information may include either or both of carrier aggregation or dual connectivity preference information for the wireless device or service data amount information for the wireless device. The cellular base station may select a carrier aggregation or dual connectivity configuration for the wireless device based on the assistance information, and may provide configuration information for the selected configuration to the wireless device.