Wireless communication method, wireless communication system, base station, and wireless station
A wireless communication method including: when a wireless station has dual connectivity to a first base station that is a primary base station and a second base station that is a secondary base station and when a handover of the primary base station is to be performed from the first base station to a third base station, transmitting from the first base station to the third base station a first signal requesting the handover, when the third base station makes a determination not to change the secondary base station based on the first signal, transmitting from the third base station to the second base station a second signal indicating the determination and to the first base station a third signal indicating the determination, and performing the handover based on the third signal without transferring a connection between the wireless station and the second base station to the first base station.
1 . A wireless communication method comprising:
transmitting, by a first base station that is a primary base station for a wireless station, to a third base station, a first signal requesting a switching of the primary base station to the third base station when the wireless station has a multiple connection and when a handover of the wireless station from the first base station to the third base station is to be performed, wherein the multiple connection comprises at least a first connection and a second connection, and the first connection is a connection between the wireless station and the first base station, and the second connection is a connection between the wireless station and a second base station that is a secondary base station for the wireless station, and wherein the first connection corresponds to a first data bearer and a first data channel between the wireless station and the first base station, and the second connection corresponds to a second data bearer and a second data channel between the wireless station and the second base station;
receiving, by the first base station from the third base station, a second signal indicating that the second connection is to be maintained, wherein the second signal includes an information element for downlink forwarding that indicates that downlink communication of the second data bearer and the second data channel is not to be transferred to the first base station or the third base station during the handover based on a determination by the third base station that the second connection is to be maintained; and
performing, by the first base station, the handover of the wireless station and the switching without transferring the second connection and the downlink communication of the second data bearer and the second data channel to neither the first base station nor the third base station based on the information element for downlink forwarding.
2 . The wireless communication method of claim 1 , wherein the first signal includes an identifier of the second base station.
3 . The wireless communication method of claim 1 , wherein performing the handover of the wireless station and the switching without transferring the second connection comprises transferring the connection to the third base station.
4 . The wireless communication method of claim 1 , wherein performing the handover of the wireless station and the switching with transferring the second connection comprises transferring the connection to the third base station.
5 . The wireless communication method of claim 1 , further comprising:
transmitting, by the first base station to the wireless station, a reference signal; and
receiving, by the first base station from the wireless station, a measurement report that includes a result of a measurement of the reference signal.
6 . The wireless communication method of claim 5 , wherein the first signal is based at least in part on the measurement report.
7 . The wireless communication method of claim 1 , further comprising:
receiving, by the first base station from the third base station, a third signal indicating that the second connection is not to be maintained, wherein the third signal includes the information element for downlink forwarding that indicates that the downlink communication of the second data bearer and the second data channel is to be transferred to the first base station or the third base station during the handover; and
performing, by the first base station, the handover of the wireless station with transferring the second connection and the downlink communication of the second data bearer and the second data channel to either the first base station or the third base station.
8 . A first base station for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the first base station to:
transmit, to a third base station, a first signal requesting a switching of the first base station that is a primary base station for a wireless station to the third base station when the wireless station has a multiple connection and when a handover of the wireless station from the first base station to the third base station is to be performed, wherein the multiple connection comprises at least a first connection and a second connection, and the first connection is a connection between the wireless station and the first base station, and the second connection is a connection between the wireless station and a second base station that is a secondary base station for the wireless station, and wherein the first connection corresponds to a first data bearer and a first data channel between the wireless station and the first base station, and the second connection corresponds to a second data bearer and a second data channel between the wireless station and the second base station;
receive, from the third base station, a second signal indicating that the second connection is to be maintained, wherein the second signal includes an information element for downlink forwarding that indicates that downlink communication of the second data bearer and the second data channel is not to be transferred to the first base station or the third base station during the handover based on a determination by the third base station that the second connection is to be maintained; and
perform the handover of the wireless station and the switching without transferring the second connection and the downlink communication of the second data bearer and the second data channel to neither the first base station nor the third base station based on the information element for downlink forwarding.
9 . The first base station of claim 8 , wherein the first signal includes an identifier of the second base station.
10 . The first base station of claim 8 , wherein, to perform the handover of the wireless station and the switching without transferring the second connection, the at least one processor is configured to cause the first base station to transfer the connection to the third base station.
11 . The first base station of claim 8 , wherein, to perform the handover of the wireless station and the switching with transferring the second connection, the at least one processor is configured to cause the first base station to transfer the connection to the third base station.
12 . The first base station of claim 8 , wherein the at least one processor is configured to cause the first base station to:
transmit, to the wireless station, a reference signal; and
receiving, from the wireless station, a measurement report that includes a result of a measurement of the reference signal.
13 . The first base station of claim 12 , wherein the first signal is based at least in part on the measurement report.
14 . The first base station of claim 8 , wherein the at least one processor is further configured to:
receive, from the third base station, a third signal indicating that the second connection is not to be maintained, wherein the third signal includes the information element for downlink forwarding that indicates that the downlink communication of the second data bearer and the second data channel is to be transferred to the first base station or the third base station during the handover; and
perform the handover of the wireless station with transferring the second connection and the downlink communication of the second data bearer and the second data channel to either the first base station or the third base station.
15 . A processor for wireless communication, comprising:
at least one controller coupled with at least one memory and configured to cause the processor to:
transmit, to a third base station, a first signal requesting a switching of a first base station that is a primary base station for a wireless station to the third base station when the wireless station has a multiple connection and when a handover of the wireless station from the first base station to the third base station is to be performed, wherein the multiple connection comprises at least a first connection and a second connection, and the first connection is a connection between the wireless station and the first base station, and the second connection is a connection between the wireless station and a second base station that is a secondary base station for the wireless station, and wherein the first connection corresponds to a first data bearer and a first data channel between the wireless station and the first base station, and the second connection corresponds to a second data bearer and a second data channel between the wireless station and the second base station;
receive, from the third base station, a second signal indicating that the second connection is to be maintained, wherein the second signal includes an information element for downlink forwarding that indicates that downlink communication of the second data bearer and the second data channel is not to be transferred to the first base station or the third base station during the handover based on a determination by the third base station that the second connection is to be maintained; and
perform the handover of the wireless station and the switching without transferring the second connection and the downlink communication of the second data bearer and the second data channel to neither the first base station nor the third base station based on the information element for downlink forwarding.
16 . The processor of claim 15 , wherein the first signal includes an identifier of the second base station.
17 . The processor of claim 15 , wherein the at least one controller is further configured to:
receive, from the third base station, a third signal indicating that the second connection is not to be maintained, wherein the third signal includes the information element for downlink forwarding that indicates that the downlink communication of the second data bearer and the second data channel is to be transferred to the first base station or the third base station during the handover; and
perform the handover of the wireless station with transferring the second connection and the downlink communication of the second data bearer and the second data channel to either the first base station or the third base station.
18 . The processor of claim 17 , wherein, to perform the handover of the wireless station and the switching with transferring the second connection, the at least one controller is configured to transfer the connection to the third base station.
19 . The processor of claim 15 , wherein the first signal includes an identifier of the second base station.
20 . The processor of claim 15 , wherein, to perform the handover of the wireless station and the switching without transferring the second connection, the at least one controller is configured to transfer the connection to the third base station.