Furthermore, the communication delay information includes, not only the propagation delay related to the time in which the signal is propagated (cable or air section) between two devices forming a direct link, but also the processing time related to modulation/demodulation of signals for communication of each device associated with communication on a communication path, coding, decoding of cryptograph, and the like. For example, a total time until the signal reaches the opposing device when a signal is transmitted from a terminal device, and a total time until the signal reaches the terminal device when a signal is transmitted from the opposing device to the terminal device, may be referred to as a communication delay. Note that the communication delay may be, for example, a delay in a direct link between the terminal device and the base station, for example. Furthermore, the communication delay may be, for example, a communication delay between the gateway that is a barrier between the networks and the terminal device, when the opposing device belongs to a network external to the cellular communication network. That is, the communication delay refers to a delay in any of some or all of the communication paths, unless specifically stated otherwise, and is not limited to any of these.

In the following, the configuration of the base station and the terminal device that execute the processes described above and some examples of the operations thereof will be described below.