Method and UE for performing random access to base station, and method and base station for establishing connection with UE

A method used in a second base station for establishing a connection with a User Equipment, UE, the UE having been in a connection with a first base station, the method comprising:

• obtaining from the first base station a subframe configuration for the UE, which indicates a first set of subframes assigned to communications between the UE and the first base station and a second set of subframes assigned to communications between the UE and the second base station;
• transmitting to the UE a Physical Downlink Control Channel, PDCCH, order for initiating random access to the second base station;
• wherein the second base station transmits the PDCCH order for initiating random access to the second base station to the UE in the second set of subframes on the same frequencies used for communications between the UE and the first base station in the first set of subframes.

A second base station for establishing a connection with a User Equipment, UE, the UE having been in a connection with a first base station, the second base station comprising:

• a control circuit configured to obtain from the first base station a subframe configuration for the UE, which indicates a first set of subframes assigned to communications between the UE and the first base station and a second set of subframes assigned to communications between the UE and the second base station;
• a first transmitter configured to transmit to the UE a Physical Downlink Control Channel, PDCCH, order for initiating the random access;
• wherein the first transmitter is configured to transmit the PDCCH order for initiating random access to the second base station to the UE on the second set of subframes on the same frequencies used for communications between the UE and the first base station in the first set of subframes.