Communication system having a communication device

A communication system is enclosed. In one embodiment, the communication system includes a communication device configured to puts itself into an activated state or into a deactivated state at alternate times. The communication device receives time information in a first operating state of the activated state, takes the received time information as a basis for ascertaining the later time at which useful information is transmitted to the communication device, receives the useful information at the later time in a second operating state of the activated state, and with individual components of the communication device being able to be put into an activated state or into a deactivated state independently of one another.