gNB distributed unit, gNB central unit and methods used therein

Abstract

The present invention relates to a gNB distributed unit, a gNB central unit, and methods used therein. The gNB distributed unit (gNB-DU) is configured to host a physical layer (PHY) and a medium access control layer (MAC). The method used by the gNB-DU includes: communicating with a user equipment (UE); and sending a message to a gNB central unit (gNB-CU) that hosts a radio resource control layer (RRC) via an F1 interface. The message includes first information indicating one or more bandwidth parts to be configured for the UE, and second information indicating at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of August 14, 2018, application number 201880073656.2, and invention name “Radio Access Network Node, Method Thereof, and Non-transitory Computer-readable Medium”. Technical Field

[0002] The present invention relates to radio communication systems and, in particular, to the use of one or more bandwidth portions configured within a carrier bandwidth. Background Art

[0003] The 3rd Generation Partnership Project (3GPP) has been working on the standardization of the fifth generation mobile communication system (5G) to make 5G a commercial reality in or after 2020. 5G is expected to be achieved through the continued enhancement / evolution of LTE and LTE-Advanced and through the introduction of innovative enhancements / evolutions of new 5G air interfaces (i.e., new radio access technologies (RATs)). The new RATs support, for example, higher frequency bands than those supported by LTE / LTE-Advanced and their continued evolution (e.g., 6 GHz or lower). For example, the new RATs support centimeter wave bands (10 GHz or higher) and millimeter wave bands (30 GHz or higher).

[0004] In this specification, the fifth generation mobile communication system is referred to as a 5G system or a next generation (NextGen) system (NG system). The new RAT of the 5G system is referred to as a new air interface (NR), 5G RAT or NG RAT. The new radio access network (RAN) of the 5G system is referred to as 5G-RAN or NextGen RAN (NG RAN). The new base station within the NG-RAN is referred to as NR NodeB (NR NB) or gNodeB (gNB). The new core network of the 5G system is referred to as the 5G core network (5G-CN or 5GC) or NextGen core (NG core). A radio terminal (i.e., user equipment (UE)) capable of connecting to the 5G system is referred to as a 5G UE or NextGen UE (NG UE), or simply as UE. As standardization progresses, the official names of the RAT, UE, radio access network, core network, network entity (node) and protocol layer used by the NG system will be determined in the future.

[0005] Unless otherwise specified, the term "LTE" used in this specification includes enhancements / evolutions of LTE and Advanced LTE to provide intercommunication with 5G systems. The enhancements / evolutions of LTE and Advanced LTE used for intercommunication with 5G systems are referred to as Advanced LTE Pro, LTE+, or enhanced LTE (eLTE). In addition, unless otherwise specified, the terms related to LTE networks and logical entities used in this specification (such as "Evolved Packet Core (EPC)", "Mobility Management Entity (MME)", "Serving Gateway (S-GW)", and "Packet Data Network (PDN) Gateway (P-GW)", etc.) include their enhancements / evolutions to provide intercommunication with 5G systems. Enhanced EPC, enhanced MME, enhanced S-GW, and enhanced P-GW are referred to as, for example, enhanced EPC (eEPC), enhanced MME (eMME), enhanced S-GW (eS-GW), and enhanced P-GW (eP-GW), respectively.

[0006] In LTE and LTE-Advanced, to achieve Quality of Service (QoS) and packet routing, bearers for each QoS level and for each PDN connection are used in both the RAN (i.e., Evolved Universal Terrestrial RAN (E-UTRAN)) and the core network (i.e., EPC). That is, in the bearer-based QoS (or per-bearer QoS) concept, one or more Evolved Packet System (EPS) bearers are configured between the UE and the P-GW in the EPC, and multiple Service Data Flows (SDFs) with the same QoS level are transmitted via one EPS bearer that meets the QoS.

[0007] In contrast, with respect to the 5G system, it is discussed that although radio bearers can be used in NG-RAN, bearers are not used in 5GC or in the interface between 5GC and NG-RAN. Specifically, PDU flows are defined instead of EPS bearers, and one or more SDFs are mapped to one or more PDU flows. The PDU flow between the 5G UE and the user plane terminal entity in the NG core (i.e., the entity corresponding to the P-GW in the EPC) corresponds to the EPS bearer in the EPS bearer-based QoS concept. The PDU flow corresponds to the finest granularity of packet forwarding and processing within the 5G system. That is, instead of the bearer-based QoS concept, the 5G system adopts a flow-based QoS (or QoS for each flow) concept. In the flow-based QoS concept, QoS is processed for each PDU flow. The association between the 5G UE and the data network is called a "PDU session". The term "PDU session" corresponds to the term "PDN connection" in LTE and Advanced LTE. Multiple PDU flows can be configured in one PDU session. The 3GPP specification defines a 5G QoS indication (5QI) corresponding to the QCI of LTE for the 5G system.

[0008] PDU flows are also referred to as "QoS flows". QoS flows are the finest granularity of QoS treatment within the 5G system. User plane traffic within a PDU session with the same N3 tag value corresponds to a QoS flow. The N3 tag corresponds to the PDU flow ID mentioned above, and the N3 tag is also referred to as a QoS flow identifier (QFI) or flow identification indication (FII). There is at least a one-to-one relationship (i.e., a one-to-one mapping) between each 5QI defined in the specification and the corresponding QFI with the same value (or number) as the 5QI.

[0009] Figure 1 The basic architecture of the 5G system is shown. The UE establishes one or more signaling radio bearers (SRBs) and one or more data radio bearers (DRBs) with the gNB. The 5GC and the gNB establish a control plane interface and a user plane interface for the UE. The control plane interface between the 5GC and the gNB (i.e., the RAN) is called the N2 interface, NG2 interface, or NG-c interface, and is used for the transfer of non-access stratum (NAS) information and for the transfer of control information (e.g., N2 AP information elements) between the 5GC and the gNB. The user plane interface between the 5GC and the gNB (i.e., the RAN) is called the N3 interface, NG3 interface, or NG-u interface, and is used for the transfer of packets of one or more PDU flows within a PDU session of the UE.

[0010] Notice, Figure 1 The architecture shown is just one of the 5G architecture options (or deployment scenarios). Figure 1 The architecture shown is called "Standalone NR (in NextGen systems)" or "Option 2". 3GPP further discusses the network architecture for multi-connectivity operation using E-UTRA and NR radio access technologies. A representative example of multi-connectivity operation is dual connectivity (DC), in which a master node (MN) and a secondary node (SN) cooperate with each other and communicate with one UE simultaneously. Dual connectivity operation using E-UTRA and NR radio access technologies is called Multi-RAT Dual Connectivity (MR-DC). MR-DC is a dual connectivity between an E-UTRA node and an NR node.

[0011] In MR-DC, one of the E-UTRA node (i.e., eNB) and the NR node (i.e., gNB) operates as a master node (MN), while the other operates as a secondary node (SN), and at least the MN is connected to the core network. The MN provides one or more primary cell group (MCG) cells to the UE, while the SN provides one or more secondary cell group (SCG) cells to the UE. MR-DC includes "MR-DC using EPC" and "MR-DC using 5GC."

[0012] MR-DC with EPC includes E-UTRA-NR Dual Connectivity (EN-DC). In EN-DC, the UE is connected to an eNB operating as a mobile node (MN) and a gNB operating as a network (SN). Furthermore, the eNB (i.e., the primary eNB) is connected to the EPC, while the gNB (i.e., the secondary gNB) is connected to the primary eNB via the X2 interface.

[0013] MR-DC using 5GC includes NR-E-UTRA dual connectivity (NE-DC) and NG-RAN E-UTRA-NR dual connectivity (NG-EN-DC). In NE-DC, the UE is connected to a gNB operating as a mobile node and an eNB operating as a network node, the gNB (i.e., primary gNB) is connected to the 5GC, and the eNB (i.e., secondary gNB) is connected to the primary gNB via the Xn interface. On the other hand, in NG-EN-DC, the UE is connected to an eNB operating as a mobile node and a gNB operating as a network node, the eNB (i.e., primary eNB) is connected to the 5GC, and the gNB (i.e., secondary gNB) is connected to the primary eNB via the Xn interface.

[0014] Figure 2 、 Figure 3 and Figure 4 The network structures of the three DC types (i.e., EN-DC, NE-DC, and NG-EN-DC) are shown separately. Figure 2 The secondary gNB (SgNB) in the EN-DC is also called en-gNB, and Figure 3 Secondary eNB (SeNB) and Figure 4 The master eNB (MeNB) in NG-EN-DC is also referred to as ng-eNB, but in this specification, all three are referred to simply as gNB or eNB. The 5G system also supports dual connectivity between two gNBs. In this specification, dual connectivity between two gNBs is referred to as NR-NR DC. Figure 5 The network structure of NR-NR DC is shown.

[0015] NR is expected to use different sets of radio parameters in multiple frequency bands. Each set of radio parameters is called a "numerology." The OFDM numerology used by the Orthogonal Frequency Division Multiplexing (OFDM) system includes, for example, subcarrier spacing, system bandwidth, Transmit Time Interval (TTI) length, subframe duration, cyclic prefix length, and symbol duration. The 5G system supports various types of services with different service requirements, including, for example, enhanced mobile broadband (eMBB), highly reliable and low-latency communications (URLLC), and M2M communications with a large number of connections (e.g., massive machine type communications (mMTC)). The choice of numerology depends on the service requirements.

[0016] UEs and NR gNBs in 5G systems support aggregation of multiple NR carriers with different digital schemes. 3GPP discusses how this aggregation can be achieved through lower-layer aggregation (such as existing LTE carrier aggregation (CA)) or higher-layer aggregation (such as existing dual connectivity).

[0017] 5G NR supports channel bandwidths wider than those of LTE (e.g., hundreds of MHz). A channel bandwidth (i.e., BW Channel ) is the radio frequency (RF) bandwidth supporting one NR carrier. Channel bandwidth is also called system bandwidth. While LTE supports channel bandwidths up to 20 MHz, 5G NR supports channel bandwidths up to 500 MHz, for example.

[0018] In order to efficiently support multiple 5G services (such as broadband services like eMBB and narrow-bandwidth services like the Internet of Things (IoT)), it is preferable to multiplex these services onto a single channel bandwidth. In addition, if each 5G UE needs to support transmission and reception in a transmission bandwidth corresponding to the entire channel bandwidth, this may hinder the realization of lower cost and lower power consumption of UEs used for narrow-bandwidth IoT services. Therefore, 3GPP allows one or more bandwidth parts (BWPs) to be configured in the carrier bandwidth (i.e., channel bandwidth or system bandwidth) of each NR component carrier. Multiple BWPs in one NR channel bandwidth can be used for different frequency division multiplexing (FDM) schemes using different digital schemes (e.g., subcarrier spacing (SCS)). The bandwidth part is also called the carrier bandwidth part.

[0019] A bandwidth part (BWP) is frequency continuous and includes adjacent physical resource blocks (PRBs). The bandwidth of a BWP is at least as large as a synchronization signal (SS) / physical broadcast channel (PBCH) block. A BWP may or may not include SS / PBCH blocks (SSBs). The BWP configuration includes, for example, a digital scheme, a frequency position, and a bandwidth (e.g., the number of PRBs). In order to specify the frequency position, a common PRB indexing is used at least for the downlink (DL) BWP configuration in the radio resource control (RRC) connected state. Specifically, the offset of the SSB to be accessed by the UE from PRB 0 to the lowest PRB is configured by upper layer signaling. The reference point "PRB 0" is common to all UEs sharing the same broadband component carrier.

[0020] One SS / PBCH block includes the main signals required by idle UEs, such as the NR synchronization signal (NR-SS) and the NR physical broadcast channel (NR-PBCH). NR-SS is used by UEs for DL ​​synchronization. Reference signals (RS) are transmitted in SS / PBCH blocks to enable idle UEs to perform radio resource management (RRM) measurements (e.g., RSRP measurements). The RS can be the NR-SS itself or an additional RS. NR-PBCH broadcasts a portion of the minimum system information (SI) (e.g., the master information block (MIB)). The remaining minimum SI (RMSI) is transmitted on the physical downlink shared channel (PDSCH).

[0021] The network can transmit multiple SS / PBCH blocks within the channel bandwidth of a wideband component carrier. In other words, SS / PBCH blocks can be transmitted in multiple BWPs within the channel bandwidth. In the first approach, all SS / PBCH blocks within a wideband carrier are based on the NR-SS (e.g., primary SS (PSS) and secondary SS (SSS)) corresponding to the same physical layer cell identifier. In the second approach, different SS / PBCH blocks within a wideband carrier can be based on NR-SS corresponding to different physical layer cell identifiers.

[0022] From the UE's point of view, a cell is associated with one SS / PBCH block. Therefore, for the UE, each serving cell has a single associated SS / PBCH block in the frequency domain. Note that each serving cell is a primary cell (PCell) in carrier aggregation (CA) and dual connectivity (DC), a primary secondary cell (PSCell) in DC, or a secondary cell (SCell) in CA and DC. Such SSBs are called cell-defining SS / PBCH blocks. Cell-defining SS / PBCH blocks have associated RMSIs. Cell-defining SS / PBCH blocks are used as time references or timing references for serving cells. In addition, cell-defining SS / PBCH blocks are used for RRM measurements based on SS / PBCH blocks (SSBs). The cell-defining SS / PBCH blocks can be changed for PCell / PSCell by "synchronous reconfiguration" (e.g., reconfiguration of radio resource configuration information using the RRC reconfiguration process and without involving handover), while the cell-defining SS / PBCH blocks can be changed for SCell by "SCell release / addition".

[0023] One or more BWP configurations for each component carrier are semi-statically signaled to the UE. Specifically, for each UE-specific serving cell, one or more DL BWPs and one or more UL BWPs can be configured for the UE via dedicated RRC messages. In addition, each of the one or more BWPs configured for the UE can be activated and deactivated. The activation / deactivation of a BWP is determined not by the RRC layer but by lower layers (e.g., the medium access control (MAC) layer or the physical (PHY) layer). An activated BWP is referred to as an active BWP.

[0024] The switching of the active BWP can be performed, for example, by downlink control information (DCI) (e.g., scheduling DCI) sent on the NR physical downlink control channel (PDCCH). In other words, the deactivation of the current active BWP and the activation of a new active BWP can be performed by the DCI in the NR PDCCH. Thus, the network can activate / deactivate the BWP according to, for example, the data rate or the digital scheme required by the service, and thereby dynamically switch the active BWP used by the UE. The activation / deactivation of the BWP can be performed by a MAC control element (CE).

[0025] Figure 6 and Figure 7 Shows an example of using BWP. Figure 6 In the example shown, the channel bandwidth of one component carrier is divided into BWP#1 and BWP#2, and these two BWPs are used for FDM schemes using different digital schemes (e.g., different subcarrier spacings). Figure 7 In the example shown, narrowband BWP#1 is set within the channel bandwidth of one component carrier, and narrowband BWP#2, which is narrower than BWP#1, is further set within BWP#1. When BWP#1 or BWP#2 is activated for a UE, the UE can reduce its power consumption by refraining from receiving and transmitting within the channel bandwidth other than the active BWP.

[0026] Non-patent documents 1 to 7 disclose the above-mentioned BWP and cell-defining SS / PBCH blocks.

[0027] Prior art literature

[0028] Non-patent literature

[0029] Non-Patent Document 1: 3GPP R1-1711795, Ericsson, “On bandwidth parts and “RF” requirements”, TSG RAN1 NR Ad-Hoc #2, Qingdao, PRChina, June 2017

[0030] Non-Patent Document 2: 3GPP R2-1707624, “LS on Bandwidth Part Operation in NR”, 3GPP TSG RAN WG2#99, Berlin, Germany, August 2017

[0031] Non-Patent Document 3: 3GPP R2-1710012, “LS on Further agreements for Bandwidth part operation”, 3GPP TSG RAN WG2#99bis, Prague, Czech Republic, October 2017

[0032] Non-Patent Document 4: 3GPP R2-1710031, “Reply LS on multiple SSBs with a wideband carrier”, 3GPP TSG RAN WG2#99bis, Prague, Czech Republic, October 2017

[0033] Non-Patent Document 5: 3GPP R2-1711640, ZTE Corporation, Sane Chips, “Initial discussion on the impacts of BWP on RAN2”, 3GPP TSG-RAN WG2 Meeting #99bis, Prague, Czech Republic, October 2017

[0034] Non-Patent Document 6: 3GPP R2-1711969, Ericsson, “Text Proposal for L1 parameters for 38.331”, 3GPP TSG-RAN WG2#99bis, Prague, Czech Republic, October 2017

[0035] Non-Patent Document 7: 3GPP R2-1709861, “LS on multiple SSBs within a wideband carrier”, 3GPP TSG RAN WG2#99, Berlin, Germany, August 2017 Summary of the Invention

[0036] Problems to be solved by the invention

[0037] It's unclear how each RAN node (e.g., gNB) configured in a radio access network (RAN) learns about the BWP configuration of other nodes. One of the objectives of the embodiments disclosed herein is to provide devices, methods, and programs that facilitate enhanced inter-RAN node (e.g., inter-gNB) signaling for handling bandwidth fractions. It should be noted that this objective is only one of the objectives of the embodiments disclosed herein. Other objectives, problems, and novel features will become apparent from the following description and accompanying drawings.

[0038] Solutions for solving problems

[0039] In a first aspect, a radio access network (RAN) node device includes: a memory; and at least one processor connected to the memory, wherein the at least one processor is configured to send first control information related to at least one of one or more bandwidth parts (BWPs) configured in a system bandwidth to another RAN node.

[0040] In a second aspect, a method of a radio access network (RAN) node device includes sending first control information related to at least one of one or more bandwidth parts (BWPs) configured in a system bandwidth to other RAN nodes.

[0041] In a third aspect, a program includes instructions (software codes), wherein when the instructions (software codes) are loaded into a computer, the program causes the computer to perform the method according to the second aspect.

[0042] Effects of the Invention

[0043] According to the above aspects, the following apparatus, method, and program can be provided, wherein the apparatus, method, and program facilitate enhanced RAN node (e.g., inter-gNB) signaling for processing bandwidth portions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a diagram showing the basic architecture of the 5G system.

[0045] Figure 2 FIG. 1 is a diagram showing the network structure of EN-DC.

[0046] Figure 3 is a diagram showing the network structure of NE-DC.

[0047] Figure 4 This is a diagram showing the network structure of NG-EN-DC.

[0048] Figure 5 This is a diagram showing the network structure of NR-NR DC.

[0049] Figure 6 is a diagram showing an example of usage of a bandwidth part (BWP).

[0050] Figure 7 is a diagram showing an example of usage of a bandwidth part (BWP).

[0051] Figure 8 is a diagram showing a configuration example of a BWP and SS / PBCH blocks.

[0052] Figure 9 is a diagram showing a configuration example of a BWP and SS / PBCH blocks.

[0053] Figure 10 is a diagram showing a configuration example of a radio communication network according to the first embodiment.

[0054] Figure 11 is a sequence diagram showing an example of inter-node signaling according to the first embodiment.

[0055] Figure 12 is a diagram showing a configuration example of a radio communication network according to the second embodiment.

[0056] Figure 13 is a sequence diagram showing an example of signaling related to BWP configuration according to the second embodiment.

[0057] Figure 14 is a diagram showing an example of the format of a "BWP List" information element (IE).

[0058] Figure 15 is a sequence diagram showing an example of inter-node signaling according to the second embodiment.

[0059] Figure 16 is a sequence diagram showing an example of inter-node signaling according to the second embodiment.

[0060] Figure 17 is a sequence diagram showing an example of signaling between a RAN node and a UE according to the second embodiment.

[0061] Figure 18 is a diagram showing a configuration example of a radio communication network according to the third embodiment.

[0062] Figure 19 is a sequence diagram showing an example of inter-node signaling according to the third embodiment.

[0063] Figure 20 is a sequence diagram showing an example of inter-node signaling according to the third embodiment.

[0064] Figure 21 is a diagram showing a configuration example of a radio communication network according to a fourth embodiment.

[0065] Figure 22 is a sequence diagram showing an example of inter-node signaling according to the fourth embodiment.

[0066] Figure 23 is a block diagram illustrating an example of the structure of a RAN node according to some embodiments.

[0067] Figure 24 is a block diagram showing a structural example of a radio terminal according to some embodiments. DETAILED DESCRIPTION

[0068] The following describes the specific embodiments in detail with reference to the accompanying drawings. In the entire drawings, the same reference numerals are used to represent the same or corresponding elements, and for the sake of clarity, repeated descriptions will be omitted as needed.

[0069] Each embodiment described below can be used alone, or two or more of these embodiments can be appropriately combined. These embodiments include novel features that are different from each other. Therefore, these embodiments help to achieve different purposes or solve different problems, and also help to obtain different advantages.

[0070] The following description of the embodiments mainly focuses on the 3GPP 5G system. However, these embodiments can be applied to other radio communication systems.

[0071] First, refer to Figure 8 and Figure 9 To explain the definitions of terms used when one system bandwidth includes multiple BWPs. Figure 8 and Figure 9 An example of the configuration of BWP and SS / PBCH blocks is shown. Figure 8 and Figure 9 In the example shown, one channel bandwidth includes three BWPs: BWP#1, BWP#2, and BWP#3. BWP#1 and BWP#2 include SS / PBCH blocks (SSBs) #1 and SSB#2, respectively, while BWP#3 does not include any SS / PBCH blocks.

[0072] From a network perspective, as in existing LTE, the entire bandwidth of one component carrier (ie, channel bandwidth or system bandwidth) corresponds to one cell. Figure 8 and Figure 9 In the example of , the physical cell identity (PCI) associated with the cell corresponding to the channel bandwidth is "PCIx".

[0073] In this specification, a cell from the network's perspective is defined as a "logical cell." Furthermore, the PCI associated with a cell from the network's perspective (i.e., a logical cell) is defined as a base PCI. Note that a cell from the network's perspective (i.e., a logical cell) can be associated with one cell identifier. In this case, the cell identifier of the cell from the network's perspective (i.e., a logical cell) can be associated with the (sub)PCIs of multiple physical cells, as described later.

[0074] On the other hand, as previously described, from the UE's perspective, a cell is associated with a single SS / PBCH block. In this specification, a cell from the UE's perspective is defined as a "physical cell." Furthermore, the PCI associated with a cell from the UE's perspective (i.e., a physical cell) is defined as a sub-PCI. Specifically, multiple BWPs included in the same system bandwidth and each including its own SS / PBCH block are multiple UE-perspective cells (i.e., multiple physical cells). The sub-PCIs of these UE-perspective cells (i.e., physical cells) are associated with a single base PCI or cell identifier of a cell from the network's perspective (i.e., a logical cell). Furthermore, a BWP that does not include any SS / PBCH blocks can be defined as a UE-perspective cell (i.e., a physical cell), or a group of BWPs that includes a BWP without an SS / PBCH block and a BWP with an SS / PBCH block referenced by the BWP can be defined as a UE-perspective cell (i.e., a physical cell). Note that, also from the network's perspective, the unit system bandwidth actually used by the network (e.g., a RAN node) for communication with the UE is the cell from the UE's perspective (i.e., a physical cell).

[0075] exist Figure 8 In the example of , the three BWPs support the same digital scheme (i.e., digital scheme #1), and all SS / PBCH blocks within the channel bandwidth (i.e., SSB #1 and SSB #2) are based on NR-SS corresponding to the same (sub) PCI (i.e., PCIx). Figure 8This corresponds to the first approach described above regarding the transmission of multiple SS / PBCH blocks within a channel bandwidth. To synchronize with BWP#3, which does not include any SSBs, the UE monitors one of SSB#1 and SSB#2 transmitted in the other BWP. The monitored SSB#1 or SSB#2 is referred to as a reference SSB, and the UE may receive notification of the reference SSB's identifier (SSB index, e.g., SSB#1 or SSB#2) from the network.

[0076] exist Figure 9 In the example of , BWP#1 supports digital scheme #1, while BWP#2 and BWP#3 support digital scheme #2. Different SSB#1 and SSB#2 with different digital schemes are based on NR-SS corresponding to different (sub)PCIs (ie, PCIx and PCIy). Thus, Figure 9 This corresponds to the second approach described above regarding the transmission of multiple SS / PBCH blocks within a channel bandwidth. To synchronize with BWP#3, which does not include any SSBs, the UE monitors, for example, SSB#2 of BWP#2 that supports the same digital scheme as BWP#3. Alternatively, to synchronize with BWP#3, which does not include any SSBs, the UE may monitor SSB#1 of BWP#1 that supports a digital scheme different from that of BWP#3.

[0077] exist Figure 8 In the example of , the sub-PCIs (i.e., PCIx and PCIx) of two UE-viewed cells (i.e., physical cells) are associated with the base PCI (i.e., PCIx) or cell identity of one network-viewed cell (i.e., logical cell). Figure 9 In the example, the sub-PCIs (ie, PCIx and PCIy) of two UE-perspective cells (ie, physical cells) are associated with the base PCI (ie, PCIx) or cell identity of one network-perspective cell (ie, logical cell).

[0078] The network (e.g., a RAN node) can configure the UE with a BWP set that includes one or more BWPs. In other words, the UE receives configuration information (e.g., SSB index, presence of SSBs, reference SSB index, Layer 1 parameters) for one or more BWPs from the network. BWP sets can be configured separately for the downlink (DL) and uplink (UL). Thus, a BWP set can include a DL BWP set for DL ​​and a UL BWP set for UL. Alternatively, the UL BWP and DL BWP can be pre-associated with each other, in which case the BWP set can be common to both DL and UL. The UE can activate k (k <= K) of the K BWPs included in the (DL / UL) BWP set. In other words, for a particular UE, up to K (DL / UL) BWPs can be activated at one time. In the following description, for simplicity, it is assumed that one BWP is activated (i.e., k = 1). However, note that this embodiment and subsequent embodiments are also applicable to cases where two or more (k >= 2) BWPs are activated at one time.

[0079] Additionally, the term "BWP group" is used throughout this specification. A BWP group is included in a BWP set. A BWP group includes one or more BWPs, within which the active BWP can be changed via DCI sent on the NR PDCCH. Within one or more BWPs included in the same BWP group, the active BWP can be changed without changing the cell-defined SSB. Thus, a BWP group can be defined as one or more BWPs associated with the same cell-defined SSB. A BWP group can include a BWP (e.g., a base BWP, initial BWP, or default BWP) that includes a cell-defined SSB and one or more other BWPs. Each of the one or more other BWPs that are not the base BWP (or initial BWP, default BWP) may or may not include an SSB. The UE can be explicitly informed (or configured) of which SSB is the cell-defined SSB. Alternatively, the UE can implicitly assume that the cell-defined SSB is the SSB of the initial BWP when the UE is configured with a BWP group.

[0080] A BWP group can be configured separately for each of the downlink (DL) and uplink (UL). Thus, a BWP group can include a DL BWP group for DL ​​and a UL BWP group for UL. Alternatively, a UL BWP and a DL BWP can be pre-associated with each other, and in this case, the BWP group can be common to both DL and UL.

[0081] exist Figure 8 In the example of , the UE is configured with a BWP set including BWP#1 to BWP#3. Figure 8In the example shown in FIG, the UE may monitor SSB#1 transmitted in BWP#1 to synchronize with BWP#3 (i.e., to achieve synchronization in BWP#3). In this case, BWP#1 and BWP#3 may correspond to one BWP group, while BWP#2 may correspond to another BWP group. Thus, a BWP set (BWP#1, BWP#2, and BWP#3) may include a first BWP group (BWP#1 and BWP#3) and a second BWP group (BWP#2). Alternatively, a BWP set (BWP#1, BWP#2, and BWP#3) may include a first BWP group (BWP#1) and a second BWP group (BWP#2 and BWP#3). Still further, a BWP set (BWP#1, BWP#2, and BWP#3) may correspond to one BWP group (BWP#1, #2, and #3). In this case, one of SSB#1 and SSB#2 serves as the cell-defining SSB used by the UE.

[0082] Also in Figure 9 In the example shown, the UE is configured with a BWP set including BWP#1 through BWP#3. In one example, BWP#1 with digital scheme 1 can correspond to one BWP group, while BWP#2 and BWP#3 with digital scheme 2 can correspond to another BWP group. Thus, a BWP set (BWP#1, BWP#2, and BWP#3) can include a first BWP group (BWP#1) and a second BWP group (BWP#2 and BWP#3). Note that, as previously described, BWPs with different digital schemes can be included in a single BWP group. Thus, in another example, a BWP set (BWP#1, #2, and #3) can include a first BWP group (BWP#1 and BWP#3) and a second BWP group (BWP#2). Alternatively, a BWP set (BWP#1, #2, and #3) can correspond to a single BWP group (BWP#1, #2, and #3). In this case, one of SSB#1 and SSB#2 serves as the cell-defining SSB used by the UE.

[0083] As previously mentioned, BWP activation / deactivation can be performed by lower layers (e.g., the Medium Access Control (MAC) layer or the Physical (PHY) layer) rather than the RRC layer. A timer (e.g., the BWP inactivity timer in the MAC layer) can be used to activate / deactivate the DL BWP. The UE can switch the active BWP based on a timer setting value provided by the gNB. This timer can represent a time period or duration in subframes. For example, if the UE does not transmit or receive data in the active BWP for a predetermined period of time (i.e., upon expiration of the timer value), the UE switches the active BWP to a predetermined BWP (e.g., a default BWP or a BWP that includes a cell-defined SSB). This timer-based decision to change the active BWP can also be made by the network (e.g., a RAN node).

[0084] First embodiment

[0085] Figure 10 An example of the structure of a radio communication network according to this embodiment is shown. Figure 10 In the example shown in FIG1 , a radio communication network includes RAN nodes 11 and 12. RAN nodes 11 and 12 are connected to each other via interface 1001. RAN node 11 is, for example, a gNB or an eNB in ​​MR-DC. Similarly, RAN node 12 is, for example, a gNB or an eNB in ​​MR-DC. In this case, interface 1001 is an Xn interface or an (enhanced) X2 interface.

[0086] One of the RAN nodes 11 and 12 can be a central unit (CU) (e.g., a gNB-CU) in a cloud RAN (C-RAN) deployment, while the other can be a distributed unit (DU) (e.g., a gNB-DU). The central unit is also known as a baseband unit (BBU) or a digital unit (DU). The distributed unit (DU) is also known as a radio unit (RU), a remote radio head (RRH), remote radio equipment (RRE), or a transmit and receive point (TRP or TRxP). In this case, interface 1001 is the interface between the CU and the DU (e.g., the F1 interface).

[0087] Figure 11 Process 1100 is shown as an example of inter-RAN node signaling. In step 1101, RAN node 11 sends control information related to at least one of one or more BWPs configured in a component carrier bandwidth (i.e., channel bandwidth or system bandwidth) to RAN node 12. This control information is hereinafter referred to as BWP-related control information. Similarly, RAN node 12 can send BWP-related control information to RAN node 11.

[0088] In some implementations, the RAN node 11 may send BWP-related control information to inform the RAN node 12 of details of one or more BWPs configured in component carriers associated with cells operated by the RAN node 11. Additionally or alternatively, in some implementations, the RAN node 11 (e.g., a CU in a C-RAN deployment) may send BWP-related control information to indicate to the RAN node 12 (e.g., a DU in a C-RAN deployment) details of one or more BWPs to be configured in the RAN node 12.

[0089] Additionally or alternatively, in some implementations, the RAN node 12 (e.g., a DU in a C-RAN deployment) may send BWP-related control information to inform the RAN node 11 (e.g., a CU in a C-RAN deployment) of details of one or more BWPs (i.e., one or more physical cells) to be configured or available for configuration in component carriers associated with cells (i.e., logical cells) operated by the RAN node 12. Additionally or alternatively, in some implementations, the RAN node 12 (e.g., a DU in a C-RAN deployment) may send the following BWP-related control information (e.g., UE-specific BWP configuration status information) to the RAN node 11 (e.g., a CU in a C-RAN deployment), where the BWP-related control information includes information about the configuration status of one or more BWPs used by UEs camping on the (logical) cells operated by the RAN node 12.

[0090] For example, the RAN node 11 may send the above control information to the RAN node 12 during a setup procedure of the interface 1001. The RAN node 11 may send the above BWP-related control information to the RAN node 12 during a modification procedure of the interface 1001.

[0091] Thus, the RAN nodes 11 and 12 can facilitate enhanced inter-RAN node (e.g., inter-gNB) signaling for handling BWP. Thus, the RAN nodes 11 and 12 (i.e., multiple RAN nodes (e.g., gNBs)) can each be aware of the BWP configuration of the other RAN node.

[0092] The RAN node 12 may use at least a portion of the BWP-related control information received from the RAN node 11 for UE handover, interference avoidance or mitigation between neighboring cells, or determination of the SCell (i.e., secondary cell group (SCG) SCell) or SN used for DC. For example, the RAN node 12 may determine the BWP of the neighboring cell to be measured by the UE based on the BWP-related control information received from the RAN node 11. The RAN node 12 may determine the BWP of the neighboring cell to which the UE should handover (i.e., target BWP) based on the BWP-related control information received from the RAN node 11. The RAN node 12 may determine the BWP of the neighboring cell to which the UE should handover (i.e., target BWP) based on the BWP-related control information received from the RAN node 11. The RAN node 12 may determine the BWP to be used as the SCG SCell used by the UE based on the BWP-related control information received from the RAN node 11.

[0093] Additionally or alternatively, the RAN node 11 may use at least a portion of the sent BWP-related control information sent to the RAN node 12 for UE handover, interference avoidance or mitigation between neighboring cells, or determination of the SCell (i.e., secondary cell group (SCG) SCell) or SN used for DC.

[0094] In order to enable such BWP-related radio resource control, the BWP-related control information may include at least one of the following information elements (IEs):

[0095] An information element representing one or more BWP indices associated with one or more downlink BWPs;

[0096] An information element representing one or more BWP indices associated with one or more uplink BWPs;

[0097] An information element representing the carrier frequency associated with each BWP (e.g., the Absolute Radio Frequency Channel Number (ARFCN));

[0098] An information element indicating whether each BWP contains an SS / PBCH block (SSB);

[0099] An information element indicating a reference SSB associated with a BWP that does not contain any SSB, or indicating a reference BWP that contains the SSB;

[0100] Information elements representing the construction of the SSBs to be sent on each BWP (e.g., SS sequence or PCI, SSB duration, numbering scheme);

[0101] An information element indicating the offset from the reference PRB (e.g., PRB 0) to the lowest PRB of each SSB;

[0102] An information element indicating the digital scheme to which each BWP is configured; and

[0103] An information element indicating the structure of a BWP set or a BWP group (for example, information on the index of each BWP group and a list of BWP indices included in the BWP group).

[0104] These information elements (IEs) may relate to the BWP to be configured in the component carrier (or logical cell) operated by the RAN node 12. Additionally or alternatively, these information elements (IEs) may relate to the BWP configured in the component carrier (or logical cell) operated by the RAN node 11.

[0105] The BWP-related control information may include information elements (e.g., PRACH configuration IE) related to radio resources (e.g., time and frequency resource information, preamble index) in one or more UL BWPs available for random access preamble transmission. Additionally or alternatively, the BWP-related control information may include information elements indicating an uplink BWP in one or more UL BWPs to be used by the UE for random access preamble transmission. The RAN node 12 uses the BWP-related control information received from the RAN node 11 to, for example, avoid or mitigate interference between neighboring cells in random access preamble transmission.

[0106] The BWP-related control information may include one or both of the following information elements: an information element indicating the availability of network slices in each BWP; and an information element indicating the quality of service (QoS) applied to each BWP. Alternatively, the BWP-related control information may be associated with one or both of the following information elements: an information element indicating the availability of network slices in each BWP; and an information element indicating the quality of service (QoS) supported by each BWP (or applied to each BWP). The BWP-related control information may represent these information elements not in units of each BWP but in units of each BWP set or each BWP group.

[0107] For example, different network slices are provided by (or are associated with) one or more BWPs within component carriers associated with a (logical) cell operated by the RAN node 11. In this case, the RAN node 11 sends information related to these network slices to the RAN node 12. For example, each network slice can be specified by a slice type (e.g., Slice Service Type: SST). The SST can be specified by a service type (e.g., eMBB, URLLC, mMTC) or by an identifier of a core network node to which the RAN node is connected. The core network node is, for example, an Access and Mobility Management Function (AMF), a Session Management Function (SMF), or a User Plane Function (UPF). For example, the RAN node 12 can thereby determine the BWP in which the UE is to reside or the BWP to which the UE is to handover, taking into account which network slice is available or provided in each BWP of the RAN node 11. As a result, the UE can perform the desired service or obtain the expected performance (e.g., throughput, transmission rate).

[0108] Different SS / PBCH blocks in one wideband carrier are based on different NR-SS corresponding to different PCIs (e.g., Figure 9 The BWP-related control information may further include the following information element, which indicates the relationship between a base PCI (or a cell identifier) ​​associated with a cell (i.e., a logical cell) from the network perspective corresponding to the system bandwidth and a sub-PCI associated with each BWP. Figure 9 For example, the BWP-related control information may indicate that BWP#1 including SSB#1 based on the sub-PCI "PCIx" and BWP#2 including SSB#2 based on the sub-PCI "PCIy" are configured in the cell (i.e., the entire component carrier) from the perspective of the network in which the reference PCI "PCIx" is configured. Thus, even if a one-to-one mapping between a cell identifier and a PCI is not implemented, and therefore a one-to-one mapping between a cell global identifier (CGI) and a PCI is not implemented in a public land mobile network (PLMN), management and control of the physical cell used by the UE can be appropriately performed. The CGI includes, for example, a PLMN ID and a cell identifier (PLMN ID + cell ID). Management and control of the physical cell used by the UE includes, for example, managing or controlling which physical cell the UE stays in, which physical cell the UE is configured with, or which physical cell the UE is to move to.

[0109] Second embodiment

[0110] This embodiment provides a specific example of the BWP-related control information described in the first embodiment. Figure 12 An example of the structure of a radio communication network according to this embodiment is shown. Figure 12 In the example shown in FIG, a radio communication network includes gNB 21, gNB 22, and UE 23. gNBs 21 and 22 are connected to each other via interface 1201. Interface 1201 is an Xn interface. UE 23 is connected to gNB 21, gNB 22, or both via air interface 1202, 1203, or both.

[0111] Figure 13 Process 1300 is shown as an example of inter-RAN node signaling. In step 1301, gNB 21 sends BWP-related control information to gNB 22 via an Xn SETUP REQUEST message. In step 1302, gNB 22 sends the BWP-related control information to gNB 21 via an Xn SETUP RESPONSE message. When updating the BWP-related control information, gNB 22 may send the updated BWP-related control information to gNB 21 via a gNB CONFIGURATION UPDATE message (step 1303). In response to receiving the gNB CONFIGURATION UPDATE message, gNB 21 sends a gNB CONFIGURATION UPDATE ACKNOWLEDGE message to gNB 22.

[0112] BWP-related control information may be included in the served cell information IE and the neighbor cell information IE within the Xn message (e.g., Xn setup request / response (SETUP REQUEST / RESPONSE) message (step 1301 / 1302)). Specifically, the served cell information IE may include an FDD information IE (FDD Info IE) or a TDD information IE (TDD Info IE), and the FDD information IE may include a UL BWP list IE and a DL BWP list IE, while the TDD information IE may include a BWP list IE.

[0113] Additionally or alternatively, the Served Cell Information IE may include a RACH Configuration IE, and the RACH Configuration IE may indicate information about the radio resources (e.g., PRACH resources) available for preamble transmission in each (UL) BWP. Alternatively, the RACH Configuration IE may be one of the UL BWP information elements included in the UL BWP List IE. Note that a UL BWP may include a BWP that is not used for RACH (preamble transmission).

[0114] Similarly, BWP-related control information can be sent over the X2 interface between the eNB (i.e., MeNB) and gNB (i.e., SgNB) in (NG-)EN-DC. For example, the BWP-related control information can be included in the Served Cell Information IE and Neighbor Cell Information IE in the EN-DC (X2) Setup Request / Response message or the EN-DC Configuration Update / ACKNOWLEDGE message.

[0115] Figure 14 An example of the format of the (DL / UL) BWP List IE is shown. Figure 14 In the example shown in FIG5 , the (DL / UL) BWP List IE includes information elements for defining BWPs (i.e., Bandwidth Part Item IEs). Each Bandwidth Part Item IE includes mandatory IEs, including a BWP Index IE, a Position IE, a Bandwidth IE, and a Subcarrier Spacing IE. The BWP Index IE indicates the BWP index of each BWP. The Position IE indicates the frequency offset from PRB0 or ​​the cell-defining SSB to the lowest PRB of each BWP. The Bandwidth IE indicates the total number of PRBs or the frequency bandwidth of each BWP. The Subcarrier Spacing IE indicates the subcarrier spacing (SCS) applied to each BWP. The (DL / UL) BWP List IE may include information indicating the carrier frequency (e.g., ARFCN) of each BWP.

[0116] Figure 14 The Bandwidth Part Item IE shown also includes option IEs, including an SSB Presence IE and an SSB Position IE. The SSB Presence IE indicates whether the BWP includes an SSB in FDD-DL or TDD scenarios. The SSB Position IE indicates the time domain position of the SSB. When the BWP does not include an SSB, the Bandwidth Part Item IE may include information indicating its reference SSB.

[0117] Figure 15 Process 1500 is shown as an example of RAN inter-node signaling. Figure 15Involving handover of UE 23. In step 1501, the source gNB 21 sends BWP-related control information to the target gNB 22 via a HANDOVER REQUEST message. The BWP-related control information (step 1501), for example, includes the BWP configuration related to the UE 23 to be handed over. Specifically, the BWP-related control information (step 1501) may include an information element indicating one or both of the following: at least one BWP configured for UE 23 in the source gNB 21; and at least one BWP activated for UE 23 in the source gNB 21. Additionally or alternatively, the BWP-related control information (step 1501) may include an information element indicating at least one candidate BWP to which UE 23 is to hand over, among multiple BWPs configured in the target gNB 22.

[0118] In step 1502, the target gNB 22 sends BWP-related control information to the source gNB 21 via a HANDOVERREQUEST ACKNOWLEDGE message. The BWP-related control information (step 1502) may include an information element indicating at least one BWP configured (or allowed) for the UE 23 in the target gNB 22.

[0119] Figure 16 Process 1600 is shown as an example of RAN inter-node signaling. Figure 16 NR-NR DC involving UE 23, where gNB 21 is the mobile node (MN) and gNB 22 is the network (SN). In step 1601, master gNB 21 sends BWP-related control information to secondary gNB 22 via an SN Add Request message or an SN Modify Request message. The SN Add Request message is sent by master gNB 21 to secondary gNB 22 to request the preparation of resources for dual connectivity for a specific UE. On the other hand, the SN Modify Request message is sent by master gNB 21 to secondary gNB 22 to request the preparation of modifications to secondary gNB resources for a specific UE. This BWP-related control information (step 1601), for example, includes an information element indicating at least one candidate BWP to be used as the SCG SCell for NR-NR DC from among multiple BWPs configured in secondary gNB 22. This information element may be an SCG-ConfigInfo IE (i.e., an RRC message).

[0120] In step 1602, the secondary gNB 22 sends BWP-related control information to the primary gNB 21 via an SN Add Request Acknowledge (ADDITION REQUEST ACKNOWLEDGE) message or an SN Modify Request Acknowledge (MODIFICATION REQUEST ACKNOWLEDGE) message. The SN Add Request Acknowledge message is sent by the secondary gNB 22 to the primary gNB 21 to confirm the SN Add preparation. On the other hand, the SN Modify Request Acknowledge message is sent by the secondary gNB 22 to the primary gNB 21 to confirm the request from the primary gNB to modify the secondary gNB's resources. This BWP-related control information (step 1602) includes, for example, an information element indicating at least one BWP that the secondary gNB 22 has allowed or activated for NR-NR DC with UE 23. This information element may be an SCG-ConfigInfo IE (i.e., an RRC message).

[0121] In step 1603, the master gNB 21 sends BWP-related control information to the secondary gNB 22 via an SN Reconfiguration Complete message. The SN Reconfiguration Complete message is sent by the master gNB 21 to the secondary gNB 22 to indicate whether the UE 23 has applied the configuration requested by the secondary gNB 22. The BWP-related control information (step 1603) includes, for example, an information element indicating the BWP configuration applied by the UE 23. This information element can be an SCG-ConfigInfo IE (i.e., an RRC message).

[0122] Figure 17 Process 1700 is shown as an example of signaling between gNB 21 and UE 23. Figure 17 Involved Figure 9 Switching of the active BWP in the configuration example of BWP and SS / PBCH blocks is shown. Assume that, in the initial state, UE 23 is camped on any of the BWPs contained in the logical cell (Cell #1) of gNB 21. In step 1701, gNB 21 sends an RRC reconfiguration message to UE 23 containing BWP-related control information for BWP configuration. This RRC reconfiguration message contains the BWP configuration associated with BWP #1 contained in the logical cell (Cell #1). This BWP configuration indicates that SSB #1 is a cell-defined SSB.

[0123] When UE 23 is already camped on BWP#1, UE 23 configures radio parameters (e.g., Layer 2 parameters, L1 parameters) based on the BWP-related control information. On the other hand, when UE 23 is camped on a BWP different from BWP#1, UE 23 changes the active BWP to BWP#1 and configures radio parameters based on the BWP-related control information. This simplifies Layer 2 reconfiguration for UE 23 because it involves mobility between different BWPs belonging to the same logical cell (Cell#1). For example, UE 23 does not reestablish the Packet Data Convergence Protocol (PDCP) layer and the Radio Link Control (RLC) layer, and further, does not reset the MAC layer. This is expected to shorten the interruption time of data transmission or reception and avoid packet loss when changing BWPs.

[0124] In step 1702, gNB 21 sends an RRC reconfiguration message to UE 23 containing BWP-related control information for BWP reconfiguration. This BWP-related control information triggers a change in the cell-defined SSB from SSB#1 to SSB#2 and a change in the active BWP from BWP#1 to BWP#2. UE 23 changes the active BWP to BWP#2 based on this BWP-related control information. This simplifies Layer 2 reconfiguration for UE 23, as this involves mobility between different BWPs belonging to the same logical cell (Cell#1).

[0125] In step 1703, gNB 21 transmits a DCI on the PDCCH to change the active BWP. This DCI triggers a change in the active BWP from BWP#2 to BWP#3. UE 23 changes the active BWP to BWP#3 based on this DCI. However, note that since BWP#3 does not contain any SSBs, the cell-defining SSB remains unchanged, namely, SSB#2. At this point, the MAC layer (or physical layer) of UE 23 can notify the RRC layer of the change in the active BWP, and the RRC layer can change the configuration of radio parameters related to radio link control as needed.

[0126] Note that in Figure 17 In the case where UE 23 has camped on any logical cell different from the logical cell (cell #1) in the initial state before step 1701, the RRC reconfiguration message in step 1701 may include an indication of handover to BWP #1 of the logical cell (cell #1). UE 23 may perform handover according to the indication.

[0127] On the other hand, Figure 17In the initial state before step 1701, UE 23 may be in the preparation phase for establishing (or changing) the secondary cell group (SCG) in dual connectivity with gNB 21. In this case, the BWP-related control information for BWP configuration sent by gNB 21 in step 1701 may be sent to UE 23 via the RAN node (not shown) of the master cell group (MCG). For example, in NR-NR DC, gNB 21, acting as an SgNB, may send the BWP-related control information to the master gNB (MgNB) via the SN Add (or Modify) Request Confirm message in the SN Add (or Modify) procedure. The MgNB may then send the BWP-related control information to UE 23 via an RRC Reconfiguration message. Alternatively, in (NG-)EN-DC, gNB 21, acting as an SgNB, may send the BWP-related control information to the master eNB (MeNB) via the SN Add (or Modify) Request Confirm message in the SN Add (or Modify) procedure. The MeNB may then send the BWP-related control information to the UE 23 via an RRC connection reconfiguration message. Alternatively, the gNB 21, acting as an SgNB, may send the BWP-related control information directly to the UE 23 via a signaling bearer (e.g., SRB3) in the SCG. The UE 23 may configure the SCG for dual connectivity based on the BWP-related control information received from the RAN node of the MCG or from the gNB 21 (SgNB).

[0128] According to this embodiment, gNBs may be allowed to share information required for BWP configuration.

[0129] Third embodiment

[0130] This embodiment provides a specific example of the BWP-related control information described in the first embodiment. Figure 18 An example of the structure of a radio communication network according to this embodiment is shown. Figure 18 In the example shown in FIG, the radio communication network includes a gNB central unit (CU) 31, multiple gNB distributed units (DUs) 32, and a UE 33. The gNB-CU 31 is connected to each gNB-DU 32 via an interface 1801. Interface 1801 is an F1 interface. The UE 33 is connected to at least one gNB-DU 32 via at least one air interface 1802.

[0131] In some implementations, the gNB-CU 31 may provide at least NR RRC functionality, while the gNB-DU 32 may provide at least NR PHY functionality and NR MAC functionality. In such a functional deployment, the gNB-CU 31 may determine the BWP to be configured for the UE 33 in each gNB-DU 32 and notify each gNB-DU 32 of the BWP configuration used by the UE 33. Furthermore, the gNB-CU 31 may determine the BWP to be activated for the UE 33 and notify each gNB-DU 32 of the BWP. Note that each gNB-DU 32 may change the BWP to be activated for the UE 33 (i.e., the active BWP) among the BWPs configured by the gNB-CU 31. In other words, each gNB-DU 32 may determine the activation / deactivation of a BWP.

[0132] Alternatively, each gNB-DU 32 may determine a BWP to be configured for UE 33 and notify gNB-CU 31 of information related to the determined BWP. In this case, gNB-DU 32 may further determine a BWP to be activated for UE 33 and notify gNB-CU 31 of information indicating the BWP to be activated for UE 33. Alternatively, gNB-CU 31 may determine a BWP to be activated for UE 33 and notify each gNB-DU 32 of the BWP. In addition, each gNB-DU 32 may change the BWP to be activated for UE 33 (i.e., the active BWP) that has been autonomously determined by the gNB-DU (or determined by gNB-CU 31).

[0133] Figure 19 Process 1900 is shown as an example of RAN inter-node signaling. Figure 19 This involves configuring (or establishing) and updating the interface (i.e., the F1 interface) between the gNB-CU 31 and the gNB-DU 32. In step 1901, the gNB-DU 32 sends an F1 Setup Request message or a GNB-DU Configuration Update message to the gNB-CU 31. The F1 Setup Request message is sent from the gNB-DU 32 to the gNB-CU 31 to establish the F1 interface. On the other hand, the GNB-DU Configuration Update message is sent from the gNB-DU 32 to the gNB-CU 31 to notify the gNB-CU 31 of an update to the established F1 interface or a configuration update of the gNB-DU 32.

[0134] In step 1902, the gNB-CU 31 sends an F1 Setup Response message or a GNB-DU Configuration Update Confirm message to the gNB-DU 32. The F1 Setup Response message is a response to the F1 Setup Request message. The GNB-DU Configuration Update Confirm message is a response to the GNB-DU Configuration Update message.

[0135] The F1 Setup Request message or GNB-DU Configuration Update message in step 1901 may include BWP-related control information. The BWP-related control information sent in step 1901 may, for example, include at least one of the information elements (IEs) included in the aforementioned BWP-related control information. Additionally or alternatively, the BWP-related control information may include information related to at least one of the following: BWPs supported by the gNB-DU 32; a BWP that the gNB-DU 32 has determined to operate (or to operate by the gNB-DU 32); and a BWP that the gNB-DU 32 has updated.

[0136] The F1 Setup Response message or GNB-DU Configuration Update Confirm message in step 1902 may also include BWP-related control information. The BWP-related control information sent in step 1902 may include at least one of the information elements (IEs) included in the BWP-related control information described above. Additionally or alternatively, the BWP-related control information may include, for example, information related to at least one of the following: information indicating a BWP accepted (or permitted) by gNB-CU 31 from (a list of) candidate BWPs notified to gNB-CU 31 by gNB-DU 32; information indicating a BWP that gNB-CU 31 instructed gNB-DU 32 to activate; and a request from gNB-CU 31 for a change in the configuration of the BWP (e.g., SS sequence or PCI, or SSB presence).

[0137] Figure 20 Process 2000 is shown as an example of inter-RAN node signaling. In step 2001, the gNB-CU 31 sends BWP-related control information to the gNB-DU 32 via a UE Context Setup Request message or a UE Context Modification Request message. This BWP-related control information (step 2001) includes information elements (configured BWP information) indicating one or more BWPs to be configured by the gNB-CU 31 for the UE 33 connected to the gNB-DU 32.

[0138] In step 2002, the gNB-DU 32 sends BWP-related control information to the gNB-CU 31 via a CONTEXT SETUP RESPONSE message or a CONTEXT MODIFICATION RESPONSE message. The BWP-related control information in step 2002 includes BWP configuration status information related to the UE-specific configuration status of the BWP. This BWP configuration status information (step 2002) includes, for example, an information element indicating which BWP, among one or more BWPs configured by the gNB-CU 31, is to be activated for the UE 33 at the gNB-DU 32.

[0139] The message in step 2001 may also be referred to as a UE UP context setup request message or a UE UP context modification request message. Furthermore, the message in step 2002 may also be referred to as a UE UP context setup response message or a UE UP context modification response message. Furthermore, the relationship between the source and destination of these messages may be reversed.

[0140] Additionally or alternatively, when the active BWP of UE 33 is changed, for example, via DCI sent on the NR PDCCH, gNB-DU 32 may notify gNB-CU 31 that the active BWP is about to change (or has changed), or may notify gNB-CU 31 of the BWP index of the active BWP after the change. In other words, gNB-DU 32 may notify gNB-CU 31 of the update of UE-specific BWP configuration status information. Thus, gNB-CU 31 can be aware of which BWP is activated for UE 33. Thus, gNB-CU 31 can appropriately change (or reconfigure) the radio resource configuration (e.g., measurement configuration, Layer 2 configuration) via an RRC reconfiguration message based on the radio environment or load conditions in the active BWP and other BWPs (or cells). Consequently, it is expected that the radio performance (e.g., throughput performance, quality of service) of UE 33 will be maintained or improved.

[0141] Additionally or alternatively, each gNB-DU 32 may send BWP-related control information to the gNB-CU 31, where the BWP-related control information includes information elements indicating the availability of network slices that the gNB-DU 32 can support in each BWP. The gNB-CU 31 may determine the gNB-DU 32 to which the UE 33 should connect or the BWP that the UE 33 should use based on the control information.

[0142] According to this embodiment, the gNB-CU 31 and the gNB-DU 32 may be allowed to share information required for BWP configuration.

[0143] Fourth embodiment

[0144] This embodiment provides a specific example of the BWP-related control information described in the first embodiment. Figure 21 An example of the structure of a radio communication network according to this embodiment is shown. Figure 21 In the example, the radio communication network includes a control plane (CP) unit (gNB-CU-CP) 41 and a user plane (UP) unit (gNB-CU-UP) 42 of a gNB central unit (CU), a gNB distributed unit (DU) 43, and a UE 44.

[0145] The gNB-CU-CP 41 is connected to the gNB-CU-UP 42 via interface 2101. Interface 2101 is an E1 interface. The gNB-CU-CP 41 is connected to the gNB-DU 43 via interface 2102. Interface 2102 is an F1-C interface. The gNB-CU-UP 42 is connected to the gNB-DU 43 via interface 2103. Interface 2103 is an F1-U interface. The UE 44 is connected to at least one gNB-DU 43 via at least one air interface 2104.

[0146] In some implementations, the gNB-CU-CP 41 may provide at least NR RRC functionality and at least a portion of PDCP functionality (e.g., functionality required for RRC and NAS signaling). The gNB-CU-UP 42 may provide at least at least a portion of NR PDCP functionality (e.g., functionality required for UP data). The gNB-DU 43 may provide at least NR PHY functionality and NR MAC functionality. In such a functional deployment, the gNB-CU-CP 41 may determine the BWP to be configured for the UE 44 in the gNB-DU 43, and the gNB-CU-CP 41 may configure the gNB-CU-UP 42 and gNB-DU 43 with these BWPs. Note that the exchange and control of information related to the BWP between the gNB-CU-CP 41 and the gNB-DU 43 may be similar to the third embodiment ( Figure 18 ) The exchanges and controls between gNB-CU 31 and gNB-DU 32 are the same.

[0147] Figure 22Process 2200 is shown as an example of inter-RAN node signaling. In step 2201, the gNB-CU-CP 41 sends BWP-related control information to the gNB-CU-UP 42 via an E1 UE Context Setup Request message or an E1 UE Context Modify Request message. The BWP-related control information (step 2201) includes information elements (configured BWP information) indicating one or more BWPs to be configured by the gNB-CU-CP 41 for the UE 44 connected to the gNB-CU-UP 42.

[0148] In step 2202, the gNB-CU-UP 42 sends BWP-related control information to the gNB-CU-CP 41 via an E1 UE Context Setup Response message or an E1 UE Context Modify Response message. The BWP-related control information in step 2202 includes BWP configuration status information related to the UE-specific configuration status of the BWP.

[0149] The message in step 2201 may be referred to as an E1 UE UP context setup request message or a UE UP context modification request message. Furthermore, the message in step 2202 may be referred to as an E1 UE UP context setup response message or a UE UP context modification response message. Furthermore, the relationship between the source and destination of each of these messages may be reversed.

[0150] The following provides structural examples of the RAN node 11, gNB 21, gNB 22, gNB-CU 31, gNB-DU 32, UE 23, UE 33 and UE 44 according to the above-mentioned embodiment. Figure 23 1 is a block diagram showing a configuration example of the RAN node 11 according to the above-described embodiment. Figure 23 RAN node 11 includes a radio frequency transceiver 2301, a network interface 2303, a processor 2304, and a memory 2305. RF transceiver 2301 performs analog RF signal processing to communicate with NG UEs, including UE 12. RF transceiver 2301 may include multiple transceivers. RF transceiver 2301 is connected to antenna array 2302 and processor 2304. RF transceiver 2301 receives modulation symbol data from processor 2304, generates a transmit RF signal, and supplies the transmit RF signal to antenna array 2302. Furthermore, RF transceiver 2301 generates a baseband receive signal based on the receive RF signal received by antenna array 2302, and supplies the baseband receive signal to processor 2304. RF transceiver 2301 may include an analog beamformer circuit for beamforming. For example, the analog beamformer circuit includes multiple phase shifters and multiple power amplifiers.

[0151] The network interface 2303 is used to communicate with network nodes (eg, the control node and the transport node of the NG core). The network interface 2303 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0152] Processor 2304 performs digital baseband signal processing (i.e., data plane processing) and control plane processing for radio communications. Processor 2304 may include multiple processors. Processor 2304 may include, for example, a modem processor (e.g., a digital signal processor (DSP)) for digital baseband signal processing and a protocol stack processor (e.g., a central processing unit (CPU) or a microprocessor unit (MPU)) for control plane processing. Processor 2304 may include a digital beamformer module for beamforming. The digital beamformer module may include a multiple-input multiple-output (MIMO) encoder and precoder.

[0153] The memory 2305 is composed of a combination of volatile memory and non-volatile memory. The volatile memory is, for example, static random access memory (SRAM), dynamic RAM (DRAM), or any combination thereof. The non-volatile memory is, for example, mask read-only memory (MROM), electrically erasable programmable ROM (EEPROM), flash memory, a hard disk drive, or any combination thereof. The memory 2305 may include a memory configured separately from the processor 2304. In this case, the processor 2304 can access the memory 2305 via the network interface 2303 or an I / O interface (not shown).

[0154] The memory 2305 may store one or more software modules (computer programs) 2306 including instructions and data for performing the processing described in the above embodiments using the RAN node 11. In some implementations, the processor 2304 may be configured to load the software modules 2306 from the memory 2305 and execute the loaded software modules, thereby performing the processing of the RAN node 11 described in the above embodiments.

[0155] gNB 21, gNB 22, gNB-CU 31, and gNB-DU 32 may each have Figure 23 However, the gNB-CU 31 does not need to include the RF transceiver 2301 (and the antenna array 2302).

[0156] Figure 24 UE 23 is a block diagram showing a structural example of UE 23. UE 33 and UE 44 may each have Figure 24The structure is similar to the structure shown in FIG. The radio frequency (RF) transceiver 2401 performs analog RF signal processing to communicate with the NR NB 1. The RF transceiver 2401 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 2401 includes up-conversion, down-conversion, and amplification. The RF transceiver 2401 is connected to the antenna array 2402 and the baseband processor 2403. The RF transceiver 2401 receives modulation symbol data (or OFDM symbol data) from the baseband processor 2403, generates a transmit RF signal, and supplies the transmit RF signal to the antenna array 2402. In addition, the RF transceiver 2401 generates a baseband receive signal based on the receive RF signal received by the antenna array 2402, and supplies the baseband receive signal to the baseband processor 2403. The RF transceiver 2401 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0157] The baseband processor 2403 performs digital baseband signal processing (i.e., data plane processing) and control plane processing for radio communications. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) generation / decomposition of transmission formats (i.e., transmission frames), (d) channel coding / decoding, (e) modulation (i.e., symbol mapping) / demodulation, and (f) generation of OFDM symbol data (i.e., baseband OFDM signals) using an inverse fast Fourier transform (IFFT). Control plane processing, on the other hand, includes communication management for Layer 1 (e.g., transmit power control), Layer 2 (e.g., radio resource management and hybrid automatic repeat request (HARQ) processing), and Layer 3 (e.g., signaling related to attachment, mobility, and call management).

[0158] The digital baseband signal processing performed by the baseband processor 2403 may include, for example, signal processing of the Service Data Adaptation Protocol (SDAP) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, the MAC layer, and the PHY layer. In addition, the control plane processing performed by the baseband processor 2403 may include processing of the Non-Access Stratum (NAS) protocol, the RRC protocol, and the MAC CE.

[0159] The baseband processor 2403 may perform MIMO encoding and precoding for beamforming.

[0160] The baseband processor 2403 may include a modem processor (e.g., a DSP) for performing digital baseband signal processing and a protocol stack processor (e.g., a CPU or MPU) for performing control plane processing. In this case, the protocol stack processor for performing control plane processing may be integrated with the application processor 2404 described below.

[0161] The application processor 2404 is also called a CPU, MPU, microprocessor, or processor core. The application processor 2404 may include multiple processors (processor cores). The application processor 2404 loads system software programs (operating system (OS)) and various application programs (e.g., call application, web browser, email program, camera operation application, and music player application) from the memory 2406 or from other memory (not shown) and executes these programs, thereby providing various functions of the UE 23.

[0162] In some implementations, such as Figure 24 As shown by the dotted line (2405), the baseband processor 2403 and the application processor 2404 can be integrated on a single chip. In other words, the baseband processor 2403 and the application processor 2404 can be implemented on a single system-on-chip (SoC) device 2405. The SoC device may be referred to as a system large-scale integration (LSI) or a chipset.

[0163] Memory 2406 is a volatile memory, a non-volatile memory, or a combination thereof. Memory 2406 may include multiple physically independent memory devices. Volatile memory is, for example, SRAM, DRAM, or any combination thereof. Non-volatile memory is, for example, MROM, EEPROM, flash memory, a hard disk drive, or any combination thereof. Memory 2406 may include, for example, an external memory device accessible from baseband processor 2403, application processor 2404, and SoC 2405. Memory 2406 may include an internal memory device integrated within baseband processor 2403, application processor 2404, or SoC 2405. Memory 2406 may also include memory in a universal integrated circuit card (UICC).

[0164] The memory 2406 may store one or more software modules (computer programs) 2407 including instructions and data for performing the processing of the UE 23 described in the above embodiments. In some implementations, the baseband processor 2403 or the application processor 2404 may load these software modules 2407 from the memory 2406 and execute the loaded software modules, thereby performing the processing of the UE 23 described in the above embodiments with reference to the drawings.

[0165] Note that the control plane processing and operations described in the above embodiments can be implemented by elements other than the RF transceiver 2401 and the antenna array 2402, that is, by the memory 2406 storing the software module 2407 and at least one of the baseband processor 2403 and the application processor 2404.

[0166] As mentioned above Figure 23 and Figure 24 As described above, the processors included in the RAN node 11, gNB 21, gNB 22, gNB-CU 31, gNB-DU 32, UE 23, and UE 33 according to the above-described embodiments execute one or more programs including instructions for causing a computer to perform the algorithms described with reference to the accompanying drawings. Any type of non-transitory computer-readable medium can be used to store and provide the program to a computer. Non-transitory computer-readable media include any type of tangible storage medium. Examples of non-transitory computer-readable media include magnetic storage media (such as floppy disks, magnetic tapes, and hard drives), optical magnetic storage media (e.g., magneto-optical disks), compact disc read-only memories (CD-ROMs), CD-Rs, CD-R / W, and semiconductor memories (such as mask ROMs, programmable ROMs (PROMs), erasable PROMs (EPROMs), flash ROMs, and random access memories (RAMs). Any type of transitory computer-readable medium can be used to provide the program to a computer. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer readable media can provide the program to a computer via a wired communication line (eg, electric wires and optical fibers) or a wireless communication line.

[0167] Other embodiments

[0168] The above-described embodiments may each be used alone, or two or more embodiments may be appropriately combined with each other.

[0169] In the above embodiment, the switching of the active BWP using DCI sent on the NR PDCCH is described. However, it is noted that the switching of the active BWP in the above embodiment can be performed by MAC CE or a timer (e.g., BWP inactivity timer).

[0170] The above embodiments are primarily described based on the assumption that only one BWP is activated for each UE (i.e., there is one active BWP for each UE). However, the methods described in the above embodiments are also applicable to situations where multiple BWPs are simultaneously activated for a UE. For example, there may be multiple active BWPs in a BWP set. Alternatively, there may be multiple active BWPs, each corresponding to a respective BWP group in a plurality of BWP groups configured in the BWP set, or there may be multiple active BWPs in a BWP group.

[0171] In the above embodiment, UE 23 (33, 44) can support multiple (DL / UL) active BWPs within a component carrier channel bandwidth. In this case, as with the PCell and SCell in existing LTE carrier aggregation, UE 23 (33, 44) can independently perform signal processing (e.g., signal transmission and reception, TB / PDU generation, and baseband processing) for multiple BWPs managed by a (common) MAC entity. Alternatively, UE 23 (33, 44) can perform signal processing for a single broadband BWP (or broadband cell) comprising multiple BWPs. UE 23 (33, 44) can establish a bearer (i.e., SRB, DRB) for a specific active BWP. UE 23 (33, 44) can transmit the same information (i.e., control signaling, data) related to a bearer across multiple active BWPs (i.e., duplicated). The establishment of a bearer for a specific active BWP and the repeated transmission across multiple active BWPs can be configured using a logical channel ID.

[0172] Instead of a BWP, the above-described embodiment can be used for the supplementary uplink (SUL) discussed by 3GPP. The SUL uses high-band uplink (UL) and downlink (DL) carriers as basic components of the cell, and also uses a low-band UL carrier as an additional carrier (i.e., a SUL carrier). The SUL carrier is considered to be part of the UL carrier associated with the high-band DL carrier, and is therefore not considered to be a secondary cell that only includes a UL carrier. Specifically, the RAN nodes can exchange the configuration of the UL carrier used by the SUL and SUL-related information used for handover. For example, the SUL-related information may include information indicating that the BWP corresponding to the SUL carrier is a SUL carrier (e.g., BWP type = SUL, SUL index). The bandwidth of the BWP corresponding to the SUL carrier may be smaller than the SSB bandwidth.

[0173] The above embodiments can ensure that the RAN node is properly aware of and manages the active BWP used by the UE. When the UE transitions from connected mode (e.g., NR RRC_Connected) to idle mode (e.g., NR RRC_Idle), the RAN node can notify the CN node of information related to the UE's active BWP. In other words, the RAN node (e.g., gNB) can send information related to the active BWP of the UE that has released the RRC connection and NG connection to the CN node (e.g., AMF). Information related to the active BWP includes, for example, the index of the active BWP where the UE last resided (or the corresponding PCI of the active BWP) and the cell identity information containing the index. This information can be sent from the RAN node to the CN node via a UE CONTEXT RELEASE REQUEST message or a UE CONTEXT RELEASE COMPLETE message. The CN node can use (or refer to) the information related to the active BWP when subsequently paging the UE. Additionally or alternatively, the CN node may send information about the active BWP to the RAN node along with the paging message, and the RAN node may use (or refer to) this information in the determination of the paging destination (cell or BWP).

[0174] For example, the paging message in the first paging occasion may be sent only in the BWP, the BWP associated with the BWP, or multiple or all BWPs of the logical cell containing the BWP. Thus, the cells (BWPs) to which the paging message is sent can be reduced, thereby maintaining the probability of the paging message reaching the target UE at a specified target value while reducing signaling overhead and network power consumption.

[0175] Although the term "cell-defining SSB" is used in the above embodiments, this term may be referred to as a cell-representative SSB because it is an SSB that represents a BWP corresponding to a cell (i.e., a physical cell) from the UE's perspective or a BWP group corresponding to a set of physical cells. Alternatively, a cell-defining SSB may be referred to as a cell-specific SSB because a cell-defining SSB specifies the representative cell (physical cell) that includes the SSB. Furthermore, a cell-defining SSB may be referred to as a serving SSB because the cell-defining SSB is the SSB to be monitored when the UE camps on a BWP or BWP group that includes the SSB.

[0176] The sub-PCI described in the above embodiment may be associated with a BWP index.

[0177] The basic BWP described in the above embodiments may be referred to as a default BWP, an initial BWP, a reference BWP, a primary BWP, an anchor BWP, or a master BWP. Specifically, the BWP that the UE initially resides on when first accessing a RAN node (i.e., when transitioning from idle mode to connected mode) may be referred to as a basic BWP, a default BWP, an initial BWP, a reference BWP, a primary BWP, an anchor BWP, or a master BWP. Additionally or alternatively, a BWP that is not a basic BWP among multiple BWPs included in a system bandwidth may be referred to as a child BWP, a secondary BWP, or a slave BWP.

[0178] In addition, the above-mentioned embodiment is only an example of application of the technical idea obtained by the present inventors. These technical ideas are not limited to the above-mentioned embodiment, and various modifications can be made thereto.

[0179] For example, all or part of the above-described embodiments may be described as, but not limited to, the following supplementary descriptions.

[0180] (Supplementary Note 1)

[0181] A radio access network node device, namely, a RAN node device, comprising:

[0182] Memory; and

[0183] At least one processor is connected to the memory and is configured to send first control information related to at least one of the one or more bandwidth parts, ie, one or more BWPs, configured in the system bandwidth to other RAN nodes.

[0184] (Supplementary Note 2)

[0185] The RAN node device according to Supplementary Note 1, wherein the first control information includes at least one of the following information elements:

[0186] An information element representing one or more BWP indices associated with one or more downlink BWPs;

[0187] An information element representing one or more BWP indices associated with one or more uplink BWPs;

[0188] An information element representing the absolute radio frequency channel number (ARFCN) associated with each BWP;

[0189] An information element indicating whether each BWP contains a synchronization signal block (SSB);

[0190] An information element indicating a reference SSB associated with a BWP that does not contain any SSB or indicating a reference BWP that contains the reference SSB;

[0191] An information element representing the structure of the SSB to be sent on each BWP; and

[0192] An information element indicating the digital scheme configured for each BWP.

[0193] (Supplementary Note 3)

[0194] The RAN node device according to Supplementary Note 1 or 2, wherein the first control information includes the following information element, which represents a relationship between a logical cell identifier associated with a cell corresponding to the system bandwidth and a physical cell identifier (PCI) associated with each BWP in the one or more BWPs.

[0195] (Supplementary Note 4)

[0196] The RAN node device according to Supplementary Note 2 or 3, wherein the first control information further includes one or both of the following information elements: an information element indicating the availability of network slices in each BWP or each BWP set; and an information element indicating the quality of service supported by each BWP or each BWP set, i.e., QoS.

[0197] (Supplementary Note 5)

[0198] The RAN node device according to any one of Supplementary Notes 1 to 4, wherein:

[0199] The RAN node device includes a central unit (CU) that provides at least a radio resource control function (RRC function).

[0200] The other RAN nodes include a distributed unit (DU) that provides at least a medium access control function (MAC function), and

[0201] The at least one processor is configured to, in response to receiving second control information indicating one or more BWPs supported by the DU from the other RAN node, send the first control information including an information element indicating an allowed BWP among the one or more BWPs supported by the DU to the other RAN node.

[0202] (Supplementary Note 6)

[0203] The RAN node device according to any one of Supplementary Notes 1 to 4, wherein:

[0204] The RAN node device includes a central unit (CU) that provides at least a radio resource control function (RRC function).

[0205] The other RAN nodes include a distributed unit (DU) that provides at least a medium access control function (MAC function),

[0206] The first control information includes an information element indicating one or more BWPs configured by the CU for the radio terminal connected to the DU, and

[0207] The at least one processor is configured to send third control information including an information element indicating which BWP of the one or more BWPs configured by the CU is to be activated for the radio terminal at the DU to the other RAN node.

[0208] (Supplementary Note 7)

[0209] The RAN node device according to Supplementary Note 6, wherein the at least one processor is configured to receive fourth control information from the other RAN node, the fourth control information including an information element indicating a BWP to be activated for a radio terminal connected to the DU, which has been determined or changed by the DU.

[0210] (Supplementary Note 8)

[0211] The RAN node device according to any one of Supplementary Notes 1 to 4, wherein:

[0212] The at least one processor is configured to send the first control information to the other RAN node in a case where the radio terminal is handed over from the RAN node device to the other RAN node, and

[0213] The first control information includes information elements indicating one or both of the following: at least one BWP configured for the radio terminal in the RAN node device; and at least one BWP activated for the radio terminal at the RAN node device.

[0214] (Supplementary Note 9)

[0215] The RAN node device according to any one of Supplementary Notes 1 to 4, wherein:

[0216] The at least one processor is configured to send the first control information to the other RAN node in a case where the radio terminal is handed over from the RAN node device to the other RAN node, and

[0217] The first control information includes an information element indicating at least one candidate BWP to which the radio terminal is to switch from among a plurality of BWPs configured in the other RAN node.

[0218] (Supplementary Note 10)

[0219] The RAN node device according to any one of Supplementary Notes 1 to 4, wherein:

[0220] The at least one processor is configured to send the first control information to the other RAN node in a case where the radio terminal is handed over from the other RAN node to the RAN node device, and

[0221] The first control information includes an information element indicating at least one BWP configured for the radio terminal in the RAN node device.

[0222] (Supplementary Note 11)

[0223] The RAN node device according to any one of Supplementary Notes 1 to 4, wherein:

[0224] The at least one processor is configured to, in case of dual connectivity for the radio terminal in cooperation with the other RAN node, send the first control information to the other RAN node, and

[0225] The first control information includes an information element indicating at least one candidate BWP to be used for the dual connectivity among a plurality of BWPs configured in the other RAN node.

[0226] (Supplementary Note 12)

[0227] The RAN node device according to Supplementary Note 11, wherein the at least one processor is configured to receive, from the other RAN node, fifth control information including an information element indicating at least one BWP activated for performing the dual connectivity in the other RAN node.

[0228] (Supplementary Note 13)

[0229] A method for a radio access network node device, i.e., a RAN node device, the method comprising:

[0230] First control information related to at least one of the one or more bandwidth parts, ie, the one or more BWPs, configured in the system bandwidth is sent to other RAN nodes.

[0231] (Supplementary Note 14)

[0232] The method according to Supplementary Note 13, wherein the first control information includes at least one of the following information elements:

[0233] An information element representing one or more BWP indices associated with one or more downlink BWPs;

[0234] An information element representing one or more BWP indices associated with one or more uplink BWPs;

[0235] An information element representing the absolute radio frequency channel number (ARFCN) associated with each BWP;

[0236] An information element indicating whether each BWP contains a synchronization signal block (SSB);

[0237] An information element indicating a reference SSB associated with a BWP that does not contain any SSB or indicating a reference BWP that contains the reference SSB;

[0238] An information element representing the structure of the SSB to be sent on each BWP; and

[0239] An information element indicating the digital scheme configured for each BWP.

[0240] (Supplementary Note 15)

[0241] A method according to Supplementary Note 13 or 14, wherein the first control information includes the following information element, which represents a relationship between a logical cell identifier associated with a cell corresponding to the system bandwidth and a physical cell identifier (PCI) associated with each BWP in the one or more BWPs.

[0242] (Supplementary Note 16)

[0243] A method according to Supplementary Note 14 or 15, wherein the first control information further includes one or both of the following information elements: an information element indicating the availability of network slices in each BWP or each BWP set; and an information element indicating the quality of service, i.e., QoS, supported by each BWP or each BWP set.

[0244] (Supplementary Note 17)

[0245] The method according to any one of Supplementary Notes 13 to 16, wherein

[0246] The RAN node device includes a central unit (CU) that provides at least a radio resource control function (RRC function).

[0247] The other RAN nodes include a distributed unit (DU) that provides at least a medium access control function (MAC function), and

[0248] The sending includes: in response to receiving second control information indicating one or more BWPs supported by the DU from the other RAN node, sending the first control information including an information element indicating an allowed BWP among the one or more BWPs supported by the DU to the other RAN node.

[0249] (Supplementary Note 18)

[0250] The method according to any one of Supplementary Notes 13 to 16, wherein

[0251] The RAN node device includes a central unit (CU) that provides at least a radio resource control function (RRC function).

[0252] The other RAN nodes include a distributed unit (DU) that provides at least a medium access control function (MAC function),

[0253] The first control information includes an information element indicating one or more BWPs configured by the CU for the radio terminal connected to the DU, and

[0254] The method further includes sending, to the other RAN node, third control information including an information element indicating which BWP of the one or more BWPs configured by the CU is to be activated for the radio terminal at the DU.

[0255] (Supplementary Note 19)

[0256] The method according to Supplementary Note 18, further comprising: receiving fourth control information from the other RAN node, the fourth control information including an information element indicating a BWP to be activated for a radio terminal connected to the DU, which has been determined or changed by the DU.

[0257] (Supplementary Note 20)

[0258] A non-transitory computer-readable medium storing a program for causing a computer to perform a method of a radio access network node device (RAN node device), wherein the method comprises:

[0259] First control information related to at least one of the one or more bandwidth parts, ie, the one or more BWPs, configured in the system bandwidth is sent to other RAN nodes.

[0260] This application is based upon and claims the benefit of priority from Japanese patent application No. 2017-218041, filed on November 13, 2017, the entire contents of which are incorporated herein by reference.

[0261] Description of Reference Numerals

[0262] 11,12RAN nodes

[0263] 21,22gNB

[0264] 31 gNB-CU

[0265] 32 gNB-DU

[0266] 41 gNB-CU-CP

[0267] 42 gNB-CU-UP

[0268] 43 gNB-DU

[0269] 23,33,44UE

[0270] 1001 interface

[0271] 1201Xn interface

[0272] 1801F1 interface

[0273] 2304 processor

[0274] 2305 Memory

[0275] 2403 baseband processor

[0276] 2404 Application Processor

[0277] 2406 memory

Claims

1. A method for a gNB distributed unit (gNB-DU), wherein the gNB-DU is configured to host a physical layer (PHY) and a medium access control layer (MAC), the method comprising: Communicate with user equipment (UE); as well as A message is sent to a gNB central unit (gNB-CU) hosting a radio resource control layer (RRC layer) via an F1 interface, where the message includes first information and second information, where the first information indicates one or more bandwidth parts to be configured for the UE, and the second information indicates at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

2. The method according to claim 1, further comprising: The first information indicating one or more bandwidth parts to be configured for the UE and the second information indicating at least one bandwidth part among the one or more bandwidth parts to be activated for the UE are generated.

3. The method according to claim 2, wherein: The generating of the first information and the second information is performed in response to an active bandwidth part of the UE being changed from another bandwidth part to at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

4. The method according to claim 2, wherein: The one or more bandwidth parts include a first bandwidth part and a second bandwidth part, the first bandwidth part is activated for the UE, and the method further includes: Downlink control information (DCI) is sent to the UE on a physical downlink control channel (PDCCH) to change the active bandwidth part of the UE from the first bandwidth part to the second bandwidth part.

5. A method for use by a gNB Central Unit (gNB-CU), the gNB-CU being configured to host a Radio Resource Control (RRC) layer, the method comprising: Communicate with user equipment (UE); as well as A first message is received from a gNB distributed unit (gNB-DU) hosting a physical layer (PHY layer) and a medium access control layer (MAC layer) via an F1 interface, the first message including first information and second information, wherein the first information indicates one or more bandwidth parts to be configured for the UE, and the second information indicates at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

6. The method according to claim 5, further comprising: Sending a second message to the gNB-DU via the F1 interface, wherein the second message causes the gNB-DU to generate the first information indicating one or more bandwidth parts to be configured for the UE and the second information indicating at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

7. A gNB distributed unit (gNB-DU), configured to host a physical layer (PHY layer) and a medium access control layer (MAC layer), the gNB-DU comprising: An F1 interface configured to connect the gNB-DU to a gNB central unit (gNB-CU) hosting a radio resource control layer (RRC layer); and A processor is configured to send a message to the gNB-CU via the F1 interface, the message comprising first information and second information, wherein the first information indicates one or more bandwidth parts to be configured for a user equipment (UE), and the second information indicates at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

8. The gNB-DU according to claim 7, wherein: The processor is further configured to generate the first information representing one or more bandwidth parts to be configured for the UE and the second information representing at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

9. The gNB-DU according to claim 7, wherein The processor is further configured to generate the first information and the second information in response to an active bandwidth part of the UE being changed from another bandwidth part to at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

10. The gNB-DU according to claim 7, wherein The one or more bandwidth parts include a first bandwidth part and a second bandwidth part, the first bandwidth part is activated for the UE, and The processor is further configured to send downlink control information (DCI) to the UE on a physical downlink control channel (PDCCH) to change the active bandwidth part of the UE from the first bandwidth part to the second bandwidth part.

11. A gNB central unit (gNB-CU), configured to host a radio resource control layer (RRC layer), the gNB-CU comprising: An F1 interface configured to connect the gNB-CU to the gNB distributed unit (gNB-DU) hosting the physical layer (PHY layer) and the medium access control layer (MAC layer); as well as A processor is configured to receive a message from the gNB-DU via the F1 interface, the message comprising first information and second information, the first information indicating one or more bandwidth parts to be configured for a user equipment (UE), and the second information indicating at least one bandwidth part of the one or more bandwidth parts to be activated for the UE.

12. The gNB-CU according to claim 11, wherein The first information and the second information are generated in the gNB-DU.

Images