Establishing simultaneous radio connection between a user equipment and two enodebs

Abstract

A first radio station (1) requests or instructs a second radio station (2) to prepare for communication with a radio terminal (3) on a second cell (20) while a first radio connection on a first cell (10) with the radio terminal (3) is established. Further, the first radio station (1) instructs the radio terminal (3) or the second radio station (2) to establish a second radio connection on the second cell (20) with the radio terminal (3) while maintaining the radio connection on the first cell (10) with the radio terminal (3). It is thus for example possible to enable a single radio terminal to establish radio connections with cells of a plurality of radio stations, in order to achieve carrier aggregation of cells operated by different radio stations.

1 - 45 . (canceled) 
     
     
         46 . A first radio station configured to operate a first cell, the first radio station comprising:
 a memory storing instructions; and   at least one processor configured to process the instructions to:
 send, to a second radio station which is configured to operate a second cell, a first request for the second radio station, wherein the first request is configured to request the second radio station to prepare for communication with a radio terminal on the second cell, while an established first radio connection between the first radio station and the radio terminal is maintained on the first cell, 
 receive, from the second radio station, radio resource configuration information of the second cell, and 
 transmit, to the radio terminal, a Radio Resource Control (RRC) Connection Reconfiguration message including at least the radio resource configuration information of the second cell while the established first radio connection between the radio terminal and the first radio station is maintained, and 
   wherein the first request includes an Identity which indicates a data path for user data, between the radio terminal and a data transferring apparatus in a core network via the second radio station, for the communication with the radio terminal on the second cell.   
     
     
         47 . The first radio station according to  claim 46 , wherein
 the RRC Connection Reconfiguration message is configured to cause the radio terminal to add the second cell while the established first radio connection between the radio terminal and the first radio station is maintained.   
     
     
         48 . The first radio station according to  claim 46 , wherein the at least one processor is configured to process the instructions to:
 instruct at least one of the radio terminal and the second radio station, to establish a second radio connection on the second cell.   
     
     
         49 . The first radio station according to  claim 48 , wherein the at least one processor is configured to process the instructions to:
 notify the second radio station of at least one of terminal individual information of the radio terminal related to establishment of the first radio connection or the second radio connection, radio connection configuration information related to establishment of the first radio connection or the second radio connection and radio access information related to the first radio connection or the second radio connection.   
     
     
         50 . The first radio station according to  claim 48 , wherein the at least one processor is configured to process the instructions to:
 receive, from the second radio station, radio access information related to the first radio connection or the second radio connection.   
     
     
         51 . The first radio station according to  claim 49 , wherein the terminal individual information includes at least one of (a) radio terminal capability information, (b) radio terminal identifier information, (c) selected network information, (d) bearer information, (e) radio resource control information, (f) radio terminal mobility history information, and (g) service information. 
     
     
         52 . The first radio station according to  claim 46 , wherein the radio connection configuration information includes at least one of (a) serving cell information, (b) system information, (c) radio resource configuration information, (c) measurement configuration information, (d) mobility control information, and (f) security configuration information. 
     
     
         53 . The first radio station according to  claim 49 , wherein the radio access information includes at least one of (a) radio access identifier information and (b) radio access resource information. 
     
     
         54 . The first radio station according to  claim 48 , wherein the at least one processor is configured to process the instructions to:
 instruct the second radio station to establish the second radio connection in order to enable the radio terminal to simultaneously use the first cell and the second cell for signal reception or transmission.   
     
     
         55 . A second radio station configured to operate a second cell, the second radio station comprising:
 a memory storing instructions; and   at least one processor configured to process the instructions to:
 receive, from a first radio station which is configured to operate a first cell, a first request for the second radio station, wherein the first request is configured to request the second radio station to prepare for communication with a radio terminal on the second cell, while an established first radio connection between the first radio station and the radio terminal is maintained on the first cell, and 
 send, to the first radio station, radio resource configuration information of the second cell, 
   wherein the first radio base station is configured to transmit, to the radio terminal, a Radio Resource Control (RRC) Connection Reconfiguration message including at least the radio resource configuration information of the second cell while the established first radio connection between the radio terminal and the first radio station is maintained, and   the first request includes an Identity which indicates a data path for user data, between the radio terminal and a data transferring apparatus in a core network via the second radio station, for the communication with the radio terminal on the second cell.   
     
     
         56 . The second radio station according to  claim 55 , wherein the at least one processor is configured to process the instructions to:
 instruct the radio terminal to establish a second radio connection on the second cell.   
     
     
         57 . The second radio station according to  claim 55 , wherein the at least one processor is configured to process the instructions to:
 receive, from the first radio station, terminal individual information of the radio terminal related to establishment of the first radio connection or the second radio connection.   
     
     
         58 . The second radio station according to  claim 57 , wherein the at least one processor is configured to process the instructions to:
 trigger setup of a bearer for transferring user data of the radio terminal between an upper network and the second radio station, based on the terminal individual information.   
     
     
         59 . The second radio station according to  claim 55 , wherein the at least one processor is configured to process the instructions to:
 receive, from the first radio station, at least one of radio connection configuration information related to establishment of the first radio connection or the second radio connection and radio access information related to the first radio connection or the second radio connection.   
     
     
         60 . The second radio station according to  claim 55 , wherein the at least one processor is configured to process the instructions to:
 notify the first radio station of at least one of radio connection configuration information related to establishment of the first radio connection or the second radio connection and radio access information related to the first radio connection or the second radio connection.   
     
     
         61 . A radio terminal comprising:
 a memory storing instructions; and   at least one processor configured to process the instructions to:
 establish a first radio connection between a first radio station and the radio terminal on a first cell operated by the first radio station, 
 receive a Radio Resource Control (RRC) Connection Reconfiguration message from the first radio station, wherein the RRC Connection Reconfiguration message includes radio resource configuration information of a second cell served by a second radio station, and 
 add the second cell based on the radio resource configuration information of the second cell while the established first radio connection is maintained on the first cell, wherein 
   the RRC Connection Reconfiguration message is sent based on a first request for the second radio station, wherein the first request is configured to request the second radio station to prepare for communication with the radio terminal on the second cell, while an established first radio connection between the first radio station and the radio terminal is maintained on the first cell and wherein the first request includes an Identity which indicates a data path for user data, between the radio terminal and a data transferring apparatus in a core network via the second radio station, for the communication with the radio terminal on the second cell.   
     
     
         62 . The radio terminal according to  claim 61 , wherein
 the first cell is a primary cell,   the second cell is a secondary cell, and   the at least one processor is configured to process the instructions to send at least one of Layer 1 control information and Layer 2 control information using a physical uplink control channel on the second cell.   
     
     
         63 . A communication control method in a first radio station configured to operate a first cell, the method comprising:
 sending, to a second radio station which is configured to operate a second cell, a first request for the second radio station, wherein the first request is configured to request the second radio station to prepare for communication with a radio terminal on the second cell, while an established first radio connection between the first radio station and the radio terminal is maintained on the first cell;   receiving, from the second radio station, radio resource configuration information of the second cell; and   transmitting, to the radio terminal, a Radio Resource Control (RRC) Connection Reconfiguration message including at least the radio resource configuration information of the second cell while the established first radio connection between the first radio station and the radio terminal is maintained, wherein   the first request includes an Identity which indicates a data path for user data, between the radio terminal and a data transferring apparatus in a core network via the second radio station, for the communication with the radio terminal on the second cell.   
     
     
         64 . A communication control method in a second radio station configured to operate a second cell, the method comprising:
 receiving, from a first radio station which is configured to operate a first cell, a first request for the second radio station, wherein the first request is configured to request the second radio station to prepare for communication with a radio terminal on the second cell, while an established first radio connection between the first radio station and the radio terminal is maintained on the first cell; and   sending, to the first radio station, radio resource configuration information of the second cell,   wherein the first radio base station is configured to transmit, to the radio terminal, a Radio Resource Control (RRC) Connection Reconfiguration message including at least the radio resource configuration information of the second cell while the established first radio connection between the radio terminal and the first radio station is maintained, and   the first request includes an Identity which indicates a data path for user data, between the radio terminal and a data transferring apparatus in a core network via the second radio station, for the communication with the radio terminal on the second cell.   
     
     
         65 . A communication control method in a radio terminal, the method comprising:
 establishing a first radio connection between a first radio station and the radio terminal on a first cell operated by the first radio station;   receiving a Radio Resource Control (RRC) Connection Reconfiguration message from the first radio station, wherein the RRC Connection Reconfiguration message includes radio resource configuration information of a second cell served by a second radio station; and   adding the second cell based on the radio resource configuration information of the second cell while the established first radio connection is maintained on the first cell, wherein   the RRC Connection Reconfiguration message is sent based on a first request for the second radio station, wherein the first request is configured to request the second radio station to prepare for communication with the radio terminal on the second cell, while an established first radio connection between the first radio station and the radio terminal is maintained on the first cell and wherein the first request includes an Identity which indicates a data path for user data, between the radio terminal and a data transferring apparatus in a core network via the second radio station, for the communication with the radio terminal on the second cell.