A communication system, a user equipment and a base station are disclosed. The communication system includes a user equipment and a base station, wherein the user equipment is configured in a first communication system and having a co-existence working mode in which the user equipment performs a first communication with a base station in the first communication system and performs a second communication with an apparatus of a second communication system, which is different from the first communication system in a time-division multiplexing manner or a frequency-division multiplexing manner.