Communication device and system

A system, comprising:

• a first communication device;
• and
• a second communication device,
• wherein the first communication device includes a first controller configured to control a process relating to transmission of a first authentication signal used for a first authentication process that is authentication between the first communication device and the second communication device and reception of a second authentication signal,
• wherein the second communication device includes a second controller configured to control a process relating to reception of the first authentication signal and transmission of the second authentication signal,
• wherein the second controller transmits a signal used for a second authentication process that is authentication different from the first authentication process before reception of the first authentication signal,
• wherein carrier frequency of the first authentication signal and the second authentication signal is lower than carrier frequency of signals used for the second authentication process,
• wherein the controller of the communication device generates and transmits the first authentication signal to the another communication device, without a result of a distance measurement from the second authentication process, and
• wherein another controller in the another communication device generates and transmits the second authentication signal to the communication device, with the result of the distance measurement from the second authentication process.