Nec Corporation

Nec C Orporation

Nec Europe Ltd.

Nec Casio Mobile Communications, Ltd.

Hisashi Futaki

Sadafuku Hayashi

Hiroaki Aminaka

Jinsock Lee

Kojiro Hamabe

Hiroto Sugahara

Yoshikazu Kakura

Kazushi Muraoka

Toshiyuki Tamura

Yoshinori Watanabe

Giorgio Nunzi

Vivek Sharma

Masayoshi Shimizu

Kosei Kobayashi

Takanori Iwai

Caroline Jactat

Yuhua Chen

Hajime Zembutsu

Naoaki Suzuki

Tomu Tamura

Anand Raghawa Prasad

Kenji Koyanagi

Kengo Oketani

Tetsu Ikeda

Daisuke Mizukami

Hironori Ito

Robert Arnott

Shousei Yoshida

Yoshio Ueda

Takamichi Inoue

Yasushi Maruta

Motoki Morita

Takahiro Nobukiyo

Neeraj Gupta

Sheeba Backia Mary Baskaran

Sivabalan Arumugam

Takumi Ito

Daisuke Ogura

Nobuhiko Itoh

Tomoaki Hokao

Sivakamy Lakshminarayanan

Chadi Khirallah

Kenki Takagi

Kazuki Eguchi

Ling Xu

Tooru Kikuchi

Kouichi Kimura

Jagdeep Ahluwalia Singh

Yi Jiang

Hiroki Aoki

Hideki Bessho

Venkatarao Gonuguntla

Yoshido Ueda

A master node (MN) () controls the MN () to enable, for a radio terminal (), dual connectivity using a Master Cell Group (MCG) provided by the MN () and a Secondary Cell Group (SCG) provided by a secondary node (SN) (). The MN () sends to the SN () a first message related to a modification or release of a configuration or resource in the SN () regarding the dual connectivity. The first message explicitly or implicitly indicates that the modification or release is related to a failure of the MCG or recovery from the failure of the MCG. This, for example, allows the SN to distinguish a message regarding modification or release of an SN configuration (or resource) sent from an MN to the SN for recovery from an MCG failure from other messages.

Master node, secondary node, and methods therefor

When a downlink bandwidth part (BWP) is switched from a first BWP to a second BWP without a change of a cell defining synchronization signal block (SSB), if a reference signal type for Radio Link Monitoring (RLM) is set to an SSB type, a radio terminal () continues to use for RLM measurements a first SSB associated with the first BWP after switching of the downlink BWP to the second BWP. This for example enables the radio terminal to monitor a suitable Reference Signal (RS) for RLM measurements after switching of the DL active BWP.

Method and apparatus for radio link monitoring measurements in a system using bandwidth parts

A radio station () transmits or receives, to or from a radio terminal () in a second cell (), a CP message containing a NAS message or an RRC message or both, when a predetermined condition is satisfied. The second cell () 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).

Methods and apparatuses for transmitting control-plane messages in cells using different radio access technologies

During handover of a radio terminal () from a first network to a second network, a target RAN node () is operates to: receive, from a core network (), slice information about a network slice which is included in the second network and to which the radio terminal () is to be connected; create, upon receiving the slice information, radio resource configuration information that is to be used by the radio terminal () after the handover in the second network; and transmit this radio resource configuration information through the first network to the radio terminal (). It is possible to contribute to appropriately configuring an AS layer or NAS layer of a target RAT in inter-RAT handover.

Radio access network node, radio terminal, core network node, and method therefor

A radio terminal () includes: a wireless transceiver () configured to communicate with one or more radio stations using a licensed frequency and an unlicensed frequency; and at least one processor (). The at least one processor () is configured to recognize whether LBT on the unlicensed frequency prior to uplink transmission needs to be performed, start the uplink transmission on the unlicensed frequency after performing the LBT when the LBT is needed, and start the uplink transmission without performing the LBT when the LBT is not needed. As a result, for example, the radio terminal can adaptively cope with the situation in which Listen Before Talk (LBT) by the radio terminal is needed and the situation in which it is not needed.

Radio terminal, radio station, and method performed thereby

A radio terminal () can perform carrier aggregation using a first cell () of a first radio station () and a second cell () of a second radio station (). The first radio station () or the second radio station () transmits constraint information to the radio terminal (). The constraint information contains an information element necessary to specify a reception constraint and/or transmission constraint related to the first cell () and/or the second cell () when the carrier aggregation is performed. The reception/transmission constraint is a constraint related to downlink signal reception/uplink signal transmission by the radio terminal over one or more subframe periods of the primary cell () and the secondary cell (). It is thus, for example, possible to contribute to reduction in wasteful power consumption in the radio terminal in the carrier aggregation of a plurality of cells served by different radio stations.

Radio communication system, radio station, radio terminal, communication control method, and non-transitory computer readable medium

A Distributed Unit (DU) () of a base station sends a first message to a Central Unit () of the base station in response to detecting initiation of a conditional mobility of a radio terminal () from a first cell served by the DU () to a second cell. It is thus for example possible to allow a Central Unit (CU) to be aware of satisfaction of an execution condition of a conditional mobility (or initiation of the conditional mobility).

Distributed unit, central unit, radio access network node, and method therefor

A second RAN node () associated with a second RAT sends a radio resource configuration of the second RAT to a radio terminal () via a first RAN node () associated with a first RAT. The radio resource configuration explicitly or implicitly indicates at least one numerology that is included in multiple numerologies supported by the second RAT and is different from a reference numerology. It is thus, for example, possible to allow a radio terminal to be configured with a numerology of a cell served by a secondary gNB or a target gNB in Inter-RAT Dual Connectivity between E-UTRA and NR and in a handover from E-UTRA to NR.

Radio access network node, radio terminal, and methods and non-transitory computer-readable media therefor

A Machine-to-machine (M2M) terminal () comprises a radio communication unit () and a controller (). The radio communication unit () is configured to communicate with a base station (). The controller () is configured to change at least one of a cell selection operation, a cell reselection operation, and a handover operation according to whether a specific coverage enhancement processing is required or according to whether the specific coverage enhancement processing is supported by at least one of a cell () in which the M2M terminal () camps on and a neighbouring cell () of the cell () which the M2M terminal () camps on. It is thus possible to provide an improved technique for allowing the M2M terminal that is supporting a special coverage enhancement processing for M2M terminals to camp on an appropriate cell.

Machine-to-machine (M2M) terminal, base station, method, and computer readable medium

A secondary node () transmits to a radio terminal (), via a master node (), 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 () receives, via the master node (), a second RRC message that is transmitted from the radio terminal () 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.

Radio access network node, radio terminal, and method therefor

A second RAN node () sends to a radio terminal (), via a first RAN node (), an indication of available on-demand system information that is available in a cell of the second RAN node (). 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.

Radio access network node, radio terminal, and methods and non transitory computer-readable media therefor

In response to receiving from a source RAN node (), on a direct interface (), a message requesting a handover of a radio terminal () from a first network to a second network, a target RAN node () receives at least one of slice information and flow information from a core network (), and controls communication of the radio terminal () 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 (). 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.

A radio terminal () attempts to receive a second message of a 2-step random access procedure after transmitting a first message of the 2-step random access procedure. In response to successfully receiving the second message of the 2-step random access procedure and determining that the second message explicitly or implicitly indicates a fallback to a 4-step random access procedure, the radio terminal () further attempts to receive a control message that contains an uplink grant indicating uplink resources available for transmission of a third message of a 4-step random access procedure. This contributes to, for example, reducing the load on a radio terminal that supports a fallback from the 2-step random access procedure to the 4-step random access procedure.

Radio terminal, radio access network node, and method therefor

A radio network () and a radio terminal () are configured to, when the radio terminal () is using a first cell () served by a first radio station () as a primary cell and a second cell () served by a second radio station () as a secondary cell, change the secondary cell form the second cell () to a third cell () while keeping communication status information regarding the radio terminal () on the second cell (). It is thus, for example, possible to enable a communication service in the secondary cell to be continued after the secondary cell is changed when the radio terminal which is simultaneously using a plurality of cells served by different radio stations changes the secondary cell from a cell of one radio station to a cell of another radio station.

Radio communication system, radio station, radio terminal, communication control method, and computer-readable medium

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Tokyo, Japan

Hisashi Futaki