alternatively may switch the second frequency resource in the fdd downlink frequency range to the corresponding frequency resource in the fdd uplink frequency range and transmit uplink data to the base station over the frequency resource in the fdd uplink frequency range a base station and a user equipment in the tdd system transmit data over frequency resources in the zone b and the zone c in a process as illustrated in fig8 which includes the following steps s 801 the base station bears downlink data in a downlink temporal unit and transmits the downlink data to the user equipment over the frequency resource in the zone c referred to as a third frequency resource for convenient differentiation and correspondingly the user equipment receives the downlink data transmitted from the base station over the third frequency resource in the zone c s 802 the user equipment switches the third frequency resource in the zone c to the frequency resource in the zone b referred to as a fourth frequency resource for convenient differentiation s 803 the user equipment bears uplink data in an uplink temporal unit and transmits the uplink data to the base station over the fourth frequency resource in.