Abstract: A second RAN node (2) sends to a radio terminal (3), via a first RAN node (1), an indication of available on-demand system information that is available in a cell of the second RAN node (2). It is thus, for example, possible to enabling notifying a UE of an indication about on-demand system information available in a cell served by a secondary gNB of Inter-RAT dual connectivity between E-UTRA and NR, or available in a cell served by a target gNB of Inter-RAT handover from E-UTRA to NR.

Abstract: A secondary node (2) transmits to a radio terminal (3), via a master node (1), a first RRC message indicating an execution condition of a conditional primary cell change of a primary cell of a secondary cell group from a first cell to a second cell. In addition, the secondary node (2) receives, via the master node (1), a second RRC message that is transmitted from the radio terminal (3) in response to a satisfaction of the execution condition. This contributes to, for example, allowing the secondary node to be aware of a satisfaction of an execution condition of a conditional PSCell change where RRC signaling between the secondary node and the radio terminal is performed via the master node.

Abstract: In response to receiving from a source RAN node (2), on a direct interface (101), a message requesting a handover of a radio terminal (1) from a first network to a second network, a target RAN node (3) receives at least one of slice information and flow information from a core network (5), and controls communication of the radio terminal (1) based on at least one of the slice information and the flow information. The slice information relates to a network slice in the second network. The flow information relates to at least one session to be established in the second network, serving as a bearer-less network, in order to transfer at least one packet flow of the radio terminal (1). It is thus possible, for example, to provide an Inter-RAT handover procedure involving transfer of handover signaling messages on a direct inter-base-station interface.

Abstract: A master node (1) requests a conditional PSCell addition (CPA), via an SN ADDITION REQUEST message (301), to a candidate secondary node (2). The master node (1) also requests the candidate secondary node (2) to configure an SN terminated MCG bearer via the SN ADDITION REQUEST message (301). This can, for example, contribute to mitigating a communication continuity problem caused by a Conditional PSCell Addition (CPA) failure.

Abstract: A radio terminal (3) can perform carrier aggregation using a first cell (10) of a first radio station (1) and a second cell (20) of a second radio station (2). The first radio station (1) performs, with the radio terminal (3), radio resource control for the first cell (10) and the second cell (20) in order to perform the carrier aggregation. At least one of the second radio station (2) and the radio terminal (3) is configured to transmit, to the first radio station (10), information about a problem occurring in a radio link in the second cell (20) between the second radio station (20) and the radio terminal (30) while the carrier aggregation of the first cell (10) and the second cell (20) is being performed.

Abstract: The present invention is a radio communication system having quality measurement means configured to execute quality measurement related to a service quality in communication between a radio terminal and a radio station, and information collection means configured to collect information related to a location of the radio terminal to be a target for the quality measurement, the radio communication system comprising: means configured to associate the information related to the location of the radio terminal when a predetermined condition is satisfied in an execution period of the quality measurement with results of the quality measurement.

Abstract: A radio communication system includes a first base station (11) that manages a first cell (110), a second base station (12) that manages a second cell (120), and a radio terminal (2). The radio terminal (2) supports dual connectivity involving a bearer split in which a first network bearer between the radio terminal (2) and a core network (3) is split over the first base station (11) and the second base station (12). The first base station (11) receives, from the second base station (12), bearer split status information about communication of the first network bearer in the second base station (12), and performs control of an access stratum related to the first network bearer. It is thus possible to contribute, for example, to an improvement in control of an access stratum when dual connectivity involving a bearer split is performed.

Abstract: A base station (1) controls state transitions of a radio terminal (2) among first to third RRC states. In addition, the base station (1) explicitly or implicitly informs the radio terminal (2) about whether a network slice configured in the radio terminal (2) for data communication at least in the first RRC state is available in each cell included in a RAN notification area configured by a RAN (3). It is thus, for example, possible to allow a radio terminal in a first state (e.g., RRC_INACTIVE state) to be easily aware of the availability of network slices in a cell to be reselected or a reselected cell.

Abstract: A target RAN node (3) receives, from a core network (5), a message requesting a handover of a radio terminal (1) from a bearer-based network to a bearer-less network. This handover request message includes flow information related to at least one session to be established in the bearer-less network in order to transfer at least one packet flow of the radio terminal (1). The target RAN node (3) transmits, to the core network (5), a handover acknowledge response message containing a transparent container that includes a radio resource configuration information derived from the flow information and is to be forwarded to a source RAN node associated (2) through the core network (5). It is thus, for example, possible to appropriately configuring an AS layer of a target RAT in an inter-RAT handover.

Abstract: A target RAN node (3) receives, from a core network (5), a message requesting a handover of a radio terminal (1) from a bearer-based network to a bearer-less network. This handover request message includes flow information related to at least one session to be established in the bearer-less network in order to transfer at least one packet flow of the radio terminal (1). The target RAN node (3) transmits, to the core network (5), a handover acknowledge response message containing a transparent container that includes a radio resource configuration information derived from the flow information and is to be forwarded to a source RAN node associated (2) through the core network (5). It is thus, for example, possible to appropriately configuring an AS layer of a target RAT in an inter-RAT handover.

Abstract: Disclosed is a radio communication system wherein radio terminals can communicate using a plurality of component carriers having different frequencies. The communication system has a reception start timing control means for commonly controlling the cycle of reception start timing for predetermined channels in at least some of the component carriers assigned to the radio terminals; and a reception control means for controlling the reception interval of said predetermined channels, said reception intervals being started at the reception start times in at least some of the component carriers assigned to the radio terminals.

Abstract: A secondary node (2) transmits to a radio terminal (3), via a master node (1), a first RRC message indicating an execution condition of a conditional primary cell change of a primary cell of a secondary cell group from a first cell to a second cell. In addition, the secondary node (2) receives, via the master node (1), a second RRC message that is transmitted from the radio terminal (3) in response to a satisfaction of the execution condition. This contributes to, for example, allowing the secondary node to be aware of a satisfaction of an execution condition of a conditional PSCell change where RRC signaling between the secondary node and the radio terminal is performed via the master node.

Abstract: A radio station (2) transmits or receives, to or from a radio terminal (1) in a second cell (23, 24), a CP message containing a NAS message or an RRC message or both, when a predetermined condition is satisfied. The second cell (23, 24) uses a RAT different from that of the first cell, and is used in addition and subordinate to the first cell. The predetermined condition relates to at least one of: (a) a content or type of the CP message; (b) a type of a signalling radio bearer used to transmit the CP message; (c) a transmission cause of the CP message; and (d) a type of a core network associated with the NAS message. It is thus, for example, possible to contributing to efficient transmission of control plane (CP) messages in a radio architecture that provides interworking of two different Radio Access Technologies (RATs).

Abstract: A secondary base station (2) receives a request message from a master base station (1) of Dual Connectivity. If the secondary base station (2) uses an SN terminated bearer that uses both Master Cell Group (MCG) resources and Secondary Cell Group (SCG) resources, the secondary base station (2) transmits a request acknowledge message containing a UL Configuration information element to the master base station (1) as a response to the request message. This, for example, allows the master base station and the secondary base station to deal with a situation where multiple information elements contained in a control message for the setup of an SN terminated bearer using MCG resources are inconsistent.

Abstract: A radio station (2) transmits configuration information (501) to a radio terminal (1). The configuration information (501) indicates, on a cell-by-cell basis, at least one specific cell on which the radio terminal (1) is allowed to perform at least one of data transmission and data reception on a radio bearer used for uplink transmission or downlink transmission or both via a common Packet Data Convergence Protocol (PDCP) layer (402). As a result, in a radio architecture that provides tight interworking of two different Radio Access Technologies (RATs), it is for example possible to allow an eNB to indicate, to a radio terminal (UE), a specific cell on which the UE should perform uplink transmission.

Abstract: In response to receiving from a source RAN node (2), on a direct interface (101), a message requesting a handover of a radio terminal (1) from a first network to a second network, a target RAN node (3) receives at least one of slice information and flow information from a core network (5), and controls communication of the radio terminal (1) based on at least one of the slice information and the flow information. The slice information relates to a network slice in the second network. The flow information relates to at least one session to be established in the second network, serving as a bearer-less network, in order to transfer at least one packet flow of the radio terminal (1). It is thus possible, for example, to provide an Inter-RAT handover procedure involving transfer of handover signaling messages on a direct inter-base-station interface.

Abstract: A target RAN node (3) is configured to: receive, directly from a core network (5), core network context information about a handover of a radio terminal (1) from a first network to the second network; and control communication of the radio terminal (1) based on the core network context information. The target RAN node (3) is further configured to transfer a handover signaling message to a source RAN node on a direct interface (101) in response to receiving the core network context information. The core network context information includes at least one of flow information, slice information, and security-related information. It is thus possible, for example, to provide an inter-RAT handover procedure involving transfer of handover signaling messages on a direct inter-base-station interface.

Abstract: A radio terminal, which has a function to collect and report measurement information designated by a radio network, comprises: means for receiving collection/reporting control information related to the radio terminal's execution of at least one of the collection of measurement information and the reporting of the measurement information to the radio network; and control means for executing, based on the collection/reporting control information, at least one of the collection and the reporting if execution determination information, which is related to at least one of the collection of the measurement information and the reporting of the measurement information to be executed by the local terminal, satisfies a given determination criterion.

Abstract: When a radio terminal (2) in a first RAT RRC_INACTIVE state in the first radio access network (RAN) (3) and having a Non-Access Stratum (NAS) connection with a first core network (CN) (4) associated with the first RAT moves to a cell (51) of a second RAN (6), the radio terminal (2) alters an RRC state transition operation of the radio terminal (2) depending on whether the second RAN (6) supports interworking with at least one of the first CN (4) and the first RAN (3).

Abstract: A radio communication system provided with a communication device and a radio communication network system is characterized by comprising a transmission delay estimate information transmitting means for transmitting transmission delay estimate information to the radio communication network system when the transmission condition of the transmission delay estimate information is met.