A base station, wherein the base station belongs to a first communications network, comprising: a splitting and aggregating unit, configured to establish a first interface with an access network device of a second communications network in a case of determining that heterogeneous network aggregation is to be enabled; and a notifying unit, configured to, after the splitting and aggregating unit establishes the first interface with the access network device of the second communications network, notify the access network device to establish a second radio bearer between the access network device and a user equipment UE, and notify the UE to establish the second radio bearer; wherein the splitting and aggregating unit is further configured to exchange data corresponding to the second radio bearer with the access network device through the first interface after the second radio bearer is established, and perform aggregation or splitting on the data corresponding to the second radio bearer and data corresponding to a first radio bearer between the base station and the UE; and the data that corresponds to the second radio bearer and is exchanged by the splitting and aggregating unit with the access network device through the first interface is Packet Data Convergence Protocol PDCP protocol data units PDUs; wherein: the notifying unit is specifically configured to send a negotiation message to the access network device through a second interface, wherein the negotiation message comprises data plane information, of the base station, on the first interface, and the negotiation message is further used to instruct to establish the second radio bearer; and the notifying unit is further configured to send a connection reconfiguration request message to the UE, wherein the connection reconfiguration request message is used to instruct to establish the second radio bearer; and the notifying unit is further configured to receive, through the second interface, an acknowledgment message generated by the access network device according to the negotiation message, wherein the acknowledgment message comprises data plane information, of the access network device, on the first interface. a splitting and aggregating unit, configured to establish a first interface with an access network device of a second communications network in a case of determining that heterogeneous network aggregation is to be enabled; and a notifying unit, configured to, after the splitting and aggregating unit establishes the first interface with the access network device of the second communications network, notify the access network device to establish a second radio bearer between the access network device and a user equipment UE, and notify the UE to establish the second radio bearer; wherein the splitting and aggregating unit is further configured to exchange data corresponding to the second radio bearer with the access network device through the first interface after the second radio bearer is established, and perform aggregation or splitting on the data corresponding to the second radio bearer and data corresponding to a first radio bearer between the base station and the UE; and the data that corresponds to the second radio bearer and is exchanged by the splitting and aggregating unit with the access network device through the first interface is Packet Data Convergence Protocol PDCP protocol data units PDUs; wherein: the notifying unit is specifically configured to send a negotiation message to the access network device through a second interface, wherein the negotiation message comprises data plane information, of the base station, on the first interface, and the negotiation message is further used to instruct to establish the second radio bearer; and the notifying unit is further configured to send a connection reconfiguration request message to the UE, wherein the connection reconfiguration request message is used to instruct to establish the second radio bearer; and the notifying unit is further configured to receive, through the second interface, an acknowledgment message generated by the access network device according to the negotiation message, wherein the acknowledgment message comprises data plane information, of the access network device, on the first interface. the notifying unit is specifically configured to send a negotiation message to the access network device through a second interface, wherein the negotiation message comprises data plane information, of the base station, on the first interface, and the negotiation message is further used to instruct to establish the second radio bearer; and the notifying unit is further configured to send a connection reconfiguration request message to the UE, wherein the connection reconfiguration request message is used to instruct to establish the second radio bearer; and the notifying unit is further configured to receive, through the second interface, an acknowledgment message generated by the access network device according to the negotiation message, wherein the acknowledgment message comprises data plane information, of the access network device, on the first interface.