RAN Node, Radio Terminal and Their Methods

Abstract

The RAN node (1) broadcasts the first initial bandwidth part (BWP) configuration via system information and broadcasts the second initial BWP configuration via system information, or sends the second initial BWP configuration via radio terminal specific signaling. The first initial BWP configuration includes cell-specific common parameters of the first initial BWP of the cell, while the second initial BWP configuration includes cell-specific common parameters of the second initial BWP of the cell. The second initial BWP is not used by radio terminals of the first type, but is used by radio terminals of the second type. The bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP. This allows radio terminals of the second type with limited capabilities compared to radio terminals of the first type to use an initial BWP suitable for their capabilities.

Description

Technical Field

[0001] The present invention relates to a radio communication network, and more particularly to bandwidth part (BWP) configuration. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) will start studying Release 17 in the first quarter of 2020. Release 17 is planned to support a new device type called reduced-capability New Radio (NR) devices (see Non-Patent Document 1). Reduced-capability NR devices are also referred to as low-complexity NR devices or Light NR devices. Compared with high-end Enhanced Mobile Broadband (eMBB) and Ultra-Reliable Low-Latency Communication (URLLC) devices (User Equipment (UE)), the main motivation for reduced-capability NR devices is to reduce device cost and complexity. One of the potential complexity reduction features is limited radio frequency (RF) capability. Specifically, compared with eMBB and URLLC devices, it is assumed that reduced-capability NR devices have reduced UE bandwidth capabilities.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2018-064252

[0006] [Patent Document 2] International Patent Publication WO2017 / 170448

[0007] Non-Patent Documents

[0008] [Non-Patent Document 1] Ericsson, “New SID on support of reduced capability NR devices”, RP-193238, 3GPP TSG RAN Meeting #86, Sitges, Spain, December 9 - 12, 2019 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] The inventors have studied reduced-capability NR devices and found various problems. A 5G UE needs to receive minimum system information (SI) before it performs initial access. In a 5G system (5GS), the system information (SI) includes a master information block (MIB) and multiple system information blocks (SIBs), and the system information is divided into minimum SI and other SI. The minimum SI is always broadcast periodically and contains the basic information required for initial access and the information for obtaining any other SI. More specifically, the minimum SI contains the MIB and System Information Block type 1 (SIB1), while the other SI contains System Information Block type 2 (SIB2) and subsequent SIB types.

[0011] The MIB is transmitted periodically on the Broadcast Channel (BCH) and the Physical Broadcast Channel (PBCH). The MIB contains information about cell barring and also contains the basic physical layer information of the cell required to decode SIB1. More specifically, the MIB indicates the System Frame Number (SFN), the subcarrier spacing (subCarrierSpacingCommon) of SIB1, the ssb-SubcarrierOffset indicating the position of the SS / PBCH block in the frequency domain, and the Physical Downlink Control Channel (PDCCH) configuration (pdcch-ConfigSIB1) required to decode SIB1. The pdcch-ConfigSIB1 field (PDCCH-ConfigSIB1 information element) of the MIB includes the configuration of Common Resource Set (CORESET) #0 and the common search space (search space #0).

[0012] The UE determines multiple consecutive resource blocks and multiple consecutive symbols of the CORESET for the Type0-PDCCH common search space (CSS) set from the ControlResourceSetZero field (or ControlResourceSetZero information element) within the pdcch-ConfigSIB1 field of the MIB. In addition, the UE determines the PDCCH monitoring occasion from the searchSpaceZero field (or searchSpaceZero information element) within the pdcch-ConfigSIB1 field of the MIB. Then, the UE attempts to receive the Downlink Control Information (DCI) in the determined common search space #0 (i.e., the Type0-PDCCH search space). This DCI indicates the allocation of the Physical Downlink Shared Channel (PDSCH) resources for transmitting SIB1.

[0013] SIB1 is also known as the Remaining Minimum SI (RMSI). SIB1 is transmitted periodically on the Downlink Shared Channel (DL-SCH) and the Physical Downlink Shared Channel (PDSCH). SIB1 includes the information required for initial access. SIB1 also indicates the availability and scheduling of other SI (or other SIBs) (e.g., periodicity and SI window size). SIB1 also indicates whether other SIBs are provided via periodic broadcast or on demand.

[0014] More specifically, SIB1 includes cell-specific serving cell configuration (i.e., the servingCellConfigCommon field (or the servingCellConfigCommonSIB information element)). The cell-specific serving cell configuration is common to UEs performing initial access. The cell-specific serving cell configuration includes an initial downlink (DL) bandwidth part (BWP) configuration (i.e., the InitialDownlinkBWP field (or the BWP-DownlinkCommon information element)) and an initial UL BWP configuration (i.e., the InitialUplinkBWP field (or the BWP-UplinkCommon information element)).

[0015] The initial DL BWP configuration broadcast in SIB1 contains cell-specific common parameters of the initial DL BWP of the serving cell that support physical uplink control channel (PUCCH) transmission and contention-based random access. These common parameters include parameters indicating the frequency-domain position and bandwidth of the initial DL BWP (i.e., the genericParameters field in the BWP-DownlinkCommon information element (or the locationAndBandwidth field in the BWP information element)). These common parameters also include PDCCH parameters (i.e., the pdcch-ConfigCommon field (or the PDCCH-ConfigCommon information element)). These PDCCH parameters are configured for one or more common search spaces in the initial DL BWP that send DCI formats indicating PDSCH resources for broadcasting SIBs.

[0016] The initial UL BWP configuration broadcast in SIB1 contains cell-specific common parameters of the initial UL BWP of the serving cell that support PUCCH transmission and contention-based random access. These common parameters include parameters indicating the frequency-domain position and bandwidth of the initial UL BWP (i.e., the genericParameters field in the BWP-UplinkCommon information element (or the locationAndBandwidth field within the BWP information element)). Additionally, these common parameters include PUCCH parameters (i.e., the pucch-ConfigCommon field (or the PUCCH-ConfigCommon information element)). These PUCCH parameters configure a set of cell-specific PUCCH resources / parameters. The UE uses these PUCCH resources until dedicated PUCCH configuration is provided on the initial uplink BWP. These common parameters also include cell-specific random access parameters used by the UE for contention-based random access in the initial UL BWP.

[0017] The following is a supplementary description of the BWP in 5G. In the primary cell (PCell), the network configures at least an initial DL BWP and one or two (if supplementary uplink (SUL) is used) initial UL BWPs. In addition, the network can configure additional DL BWPs and dedicated UL BWPs for each UE for the serving cell. In the primary cell (PCell), the initial DL BWP and UL BWP are the DL BWP and UL BWP used by the UE for initial access, and the UE uses this initial DL BWP and UL BWP before receiving a dedicated BWP configuration.

[0018] In this specification, the term "initial BWP" is used for ease of description. The term "initial BWP" is used to refer to one or both of the initial DL BWP and the initial UL BWP.

[0019] As described above, in the PCell (i.e., the serving cell that supports PUCCH transmission and contention-based random access), the common parameters of the initial BWP are broadcast via SIB1. Therefore, the common parameters of the initial BWP of the PCell (e.g., frequency-domain location and bandwidth) are cell-specific and are common to all UEs performing initial access in this PCell. However, for example, the bandwidth of the initial BWP of a normal UE (e.g., eMBB and URLLC devices) may be too wide for an NR device with reduced UE bandwidth capabilities.

[0020] Patent Document 1 discloses that a base station configures the PDCCH region with different bandwidths according to the respective UE capabilities of the UE (see, for example, Figure 7 and paragraphs 0032, 0033, and 0037). On the other hand, Patent Document 2 discloses that a base station receives terminal capability information (UE capability) from the UE, and if the base station determines that the UE can only receive a relatively narrow bandwidth, the base station decides to transmit a broadcast channel in this relatively narrow bandwidth and notifies the UE of information about this relatively narrow bandwidth through a synchronization signal (see, for example, paragraph 0067). However, neither Patent Document 1 nor Patent Document 2 discloses any content regarding the initial BWP configuration.

[0021] One of the objects to be achieved by the embodiments disclosed herein is to provide an apparatus, method, and program that enable a second type of radio terminal having limited capabilities compared to a first type of radio terminal to use an initial BWP suitable for its capabilities. It should be noted that the above object is only one of the objects achieved by the embodiments disclosed herein. According to the following description and drawings, other objects or problems and novel features will become apparent.

[0022] Solutions to the problems

[0023] In a first aspect, a radio access network (RAN) node includes at least one memory and at least one processor coupled to the at least one memory. The at least one processor is configured to broadcast a first initial bandwidth part (BWP) configuration via system information. Further, the at least one processor is configured to broadcast a second initial BWP configuration via system information or send the second initial BWP configuration via radio terminal dedicated signaling. The first initial BWP configuration includes cell-specific common parameters of a first initial BWP of a cell. The second initial BWP configuration includes cell-specific common parameters of a second initial BWP of the cell. The first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the cell. On the other hand, the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the cell. The bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0024] In a second aspect, a radio terminal includes at least one memory and at least one processor coupled to the at least one memory. The at least one processor is configured to receive system information including a first initial bandwidth part (BWP) configuration. Further, the at least one processor is configured to receive a second initial BWP configuration via system information or via radio terminal dedicated signaling, and is configured to use the received second initial BWP configuration. The first initial BWP configuration includes cell-specific common parameters of a first initial BWP of a serving cell of the radio terminal. The second initial BWP configuration includes cell-specific common parameters of a second initial BWP of the serving cell. The first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the serving cell. On the other hand, the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the serving cell. The bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0025] In a third aspect, a method performed by a radio access network (RAN) node includes the following steps:

[0026] (a) Broadcasting a first initial bandwidth part (BWP) configuration via system information; and

[0027] (b) Broadcasting a second initial BWP configuration via system information or sending the second initial BWP configuration via radio terminal dedicated signaling.

[0028] In a fourth aspect, a method performed by a radio terminal includes the following steps:

[0029] (a) Receive system information including a first initial Bandwidth Part (BWP) configuration;

[0030] (b) Receive a second initial BWP configuration via the system information or via radio terminal specific signaling; and

[0031] (c) Use the second initial BWP configuration.

[0032] In a fifth aspect, a program includes a set of instructions (software code) which, when loaded into a computer, cause the computer to perform the method according to the third or fourth aspect above.

[0033] Advantages of the Invention

[0034] According to the above aspects, an apparatus, a method and a program can be provided that enable a second type of radio terminal having limited capabilities compared to a first type of radio terminal to use an initial BWP suitable for its capabilities. Description of the Drawings

[0035] Figure 1 Shows an example of the configuration of a radio communication network according to an embodiment;

[0036] Figure 2 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0037] Figure 3 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0038] Figure 4 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0039] Figure 5 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0040] Figure 6 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0041] Figure 7 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0042] Figure 8 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0043] Figure 9 Is a sequence diagram showing an example of the operations of a gNB and a UE according to an embodiment;

[0044] Figure 10 is a sequence diagram showing an example of operations of a RAN and a UE according to an embodiment;

[0045] Figure 11 is a flowchart showing an example of operations of a UE according to an embodiment;

[0046] Figure 12 is a sequence diagram showing an example of operations of a gNB and a UE according to an embodiment;

[0047] Figure 13 shows an example of a configuration of a gNB according to an embodiment;

[0048] Figure 14 is a sequence diagram showing an example of signaling according to an embodiment;

[0049] Figure 15 is a sequence diagram showing an example of signaling according to an embodiment;

[0050] Figure 16 is a block diagram showing an example of a configuration of a gNB according to an embodiment; and

[0051] Figure 17 is a block diagram showing an example of a configuration of a UE according to an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] Specific embodiments will be described in detail below with reference to the accompanying drawings. Throughout the drawings, the same or corresponding elements are denoted by the same reference numerals, and repeated descriptions are appropriately omitted for clarity.

[0053] Each of the embodiments described below can be used alone, or two or more than two embodiments can be appropriately combined with each other. These embodiments include novel features different from each other. Therefore, these embodiments contribute to achieving different purposes or solving different problems from each other, and also contribute to obtaining different advantages from each other.

[0054] A plurality of embodiments shown below will be mainly described with respect to the 3rd Generation Partnership Project (3GPP) 5th Generation Mobile Communication System (5G System (5GS)). However, these embodiments can be applied to other cellular communication systems that support multiple types of radio terminals and support an initial BWP similar to the initial BWP in 5GS.

[0055] First Embodiment

[0056] Figure 1 shows an example of a configuration of a radio communication network (i.e., 5GS) according to an embodiment (including this embodiment). In Figure 1In the example shown, the radio communication network includes a radio access network (RAN) node (i.e., gNB) 1 and one or more radio terminals (i.e., UEs) 2. The gNB 1 is deployed in the RAN (i.e., next generation (NG) RAN). The gNB 1 may include a gNB central unit (gNB-CU) and one or more gNB distributed units (gNB-DUs) in a cloud RAN (C-RAN) deployment. The gNB 1 provides cell 10 to multiple types of UEs. Multiple types of UEs use cell 10 as their serving cell and perform contention-based random access (CBRA) in cell 10. The gNB 1 may also provide one or more other cells. In this case, cell 10 may be the primary cell (PCell) in carrier aggregation (CA), and one or more other cells may be secondary cells (SCells). In other words, cell 10 is the cell in which the UE 2 performs the initial (RRC) connection establishment process or initiates the (RRC) connection re-establishment process.

[0057] The gNB 1 broadcasts the minimum SI (i.e., MIB and SIB1) in cell 10. The gNB 1 may also send other SI. The other SI includes all SIBs not broadcast in the minimum SI. These SIBs may be broadcast periodically on the DL-SCH, broadcast on demand on the DL-SCH (i.e., in response to a request from a radio terminal (user equipment (UE)) in radio resource control (RRC)_IDLE (idle) or RRC_INACTIVE (inactive)), or sent to a UE in RRC_CONNECTED (connected) on the DL-SCH in a dedicated manner. The other SI includes at least SIB2 to SIB9.

[0058] Each UE 2 performs cell selection or cell reselection when it is in the RRC_IDLE or RRC_INACTIVE state. Additionally, each UE 2 may perform RRC connection re-establishment when it is in the RRC_CONNECTED state. Each UE 2 receives the MIB and SIB1 in cell 10 and configures the initial DL BWP and the initial UL BWP based on the cell-specific common parameters of the initial DL BWP and the initial UL BWP included in SIB1. Then, each UE 2 performs a random access process in cell 10 by using the initial DL BWP and the initial UL BWP and initiates the RRC setup, RRC resume, or RRC re-establishment process.

[0059] In this embodiment, the UE 2 is classified into a first type and a second type. Compared with the UE of the first type, the UE of the second type is a UE with limited capabilities. Compared with the UE of the first type, the UE of the second type may have limited RF capabilities. In other words, compared with the UE of the first type, the UE of the second type can support a limited UE bandwidth (e.g., UE channel bandwidth, UE carrier bandwidth, or UE RF bandwidth). The UE of the second type may be the aforementioned reduced-capability NR device, while the UE of the first type may be a normal UE (e.g., eMBB device or URLLC device). The UE of the second type may be, for example, an industrial wireless sensor, a wearable device, or a video surveillance device (e.g., a surveillance camera).

[0060] The gNB 1 transmits a first initial BWP configuration and a second initial BWP configuration. The first initial BWP configuration includes cell-specific common parameters of the first initial BWP of cell 10. The first initial BWP includes an initial DL BWP and an initial UL BWP. The first initial BWP is used by at least the first type of UE using cell 10 as a serving cell. The first initial BWP is used by at least the first type of UE when accessing cell 10 to transition from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state. In other words, the first initial BWP is a cell-specific BWP commonly used by at least the first type of UE. The first initial BWP can also be used for the initial access of the second type of UE and can be used by the second type of UE until the second type of UE receives the second initial BWP configuration or until a predetermined timing. The predetermined timing may be, for example, the time point when the second type of UE receives a control signal, control information, or RRC message from the gNB 1 that triggers the activation of the second initial BWP configuration in the second type of UE.

[0061] The second initial BWP configuration includes cell-specific common parameters of the second initial BWP of cell 10. The second initial BWP includes one or both of an initial DL BWP and an initial UL BWP. The bandwidth of the second initial DL BWP is narrower than the bandwidth of the first initial DL BWP. The bandwidth of the second initial UL BWP is equal to or narrower than the bandwidth of the first initial UL BWP. The second initial BWP is not used by the first type of UE but is used by the second type of UE using cell 10 as a serving cell. In other words, the second initial BWP is a cell-specific BWP commonly used by the second type of UE. The second initial BWP can be used by the second type of UE when accessing cell 10 to transition from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state.

[0062] In some implementations, the cell-specific common parameters of the first initial BWP may include parameters indicating the frequency-domain position and bandwidth of the first initial DL BWP, and may also include parameters indicating the frequency-domain position and bandwidth of the first initial UL BWP. The parameters indicating the frequency-domain position and bandwidth of the first initial DL BWP may be included in the locationAndBandwidth field in the genericParameters field (or BWP information element) in the initialDownlinkBWP field (or BWP-DownlinkCommon information element) included in SIB1. The parameters indicating the frequency-domain position and bandwidth of the first initial UL BWP may be included in the locationAndBandwidth field in the genericParameters field (or BWP information element) in the initialUplinkBWP field (or BWP-UplinkCommon information element) included in SIB1.

[0063] Similarly, the cell-specific common parameters of the second initial BWP may include parameters indicating the frequency-domain position and bandwidth of the second initial DL BWP, or parameters indicating the frequency-domain position and bandwidth of the second initial UL BWP, or both. The parameters indicating the frequency-domain position and bandwidth of the second initial DL BWP may be included in the locationAndBandwidth field in the genericParameters field (or BWP information element) in the initialDownlinkBWP field (or BWP-DownlinkCommon information element) included in SIB1. The parameters indicating the frequency-domain position and bandwidth of the second initial UL BWP may be included in the locationAndBandwidth field in the genericParameters field (or BWP information element) in the initialUplinkBWP field (or BWP-UplinkCommon information element) included in SIB1. The initialDownlinkBWP field (and BWP-DownlinkCommon information element) containing the parameters indicating the frequency-domain position and bandwidth of the second initial DL BWP may be an existing field (and information element) or an extension (or branch) of an existing field (and information element). Alternatively, the field (and information element) in SIB1 containing the parameters indicating the frequency-domain position and bandwidth of the second initial DL BWP may be a separate field corresponding to the initialDownlinkBWP field (and BWP-DownlinkCommon information element), such as initialDownlinkBWP-ReducedCapability (RedCap), or initialDownlinkBWP-ReducedCapability (RedCap) and BWP-DownlinkCommonReducedCapability (RedCap). Similarly, the genericParameters field (and BWP information element) may be an existing field (and information element) or an extension (or branch) of an existing field (and information element). Alternatively, the field (and information element) in SIB1 containing the parameters indicating the frequency-domain position and bandwidth of the second initial DL BWP may be a field different from the existing genericParameters field (and BWP information element), such as the genericParametersReducedCapability (RedCap) information element, or the genericParametersReducedCapability (RedCap) and BWP-ReducedCapability (RedCap) information elements.

[0064] Additionally or alternatively, the cell-specific common parameters of the first initial BWP may include PDCCH parameters. These PDCCH parameters may configure a common search space (or searchSpaceOtherSystemInformation) for the UE to receive the DCI format indicating the PDSCH resources for broadcasting system information messages (e.g., one or more of SIB2 to SIB9), a common search space (or pagingSearchSpace) for the UE to receive the DCI format indicating the PDSCH resources for sending paging messages, and one or more other common search spaces within the first initial DL BWP.

[0065] Similarly, the cell-specific common parameters of the second initial BWP may include PDCCH parameters. These PDCCH parameters may configure a common search space (or searchSpaceOtherSystemInformation field) for the UE to receive the DCI format indicating the PDSCH resources for broadcasting system information messages (e.g., one or more of SIB2 to SIB9), a common search space (or pagingSearchSpace field) for the UE to receive the DCI format indicating the PDSCH resources for sending paging messages, and one or more other common search spaces within the second initial DL BWP. The searchSpaceOtherSystemInformation and pagingSearchSpace fields specified by the PDCCH parameters in the cell-specific common parameters of the second initial BWP may be existing fields or extensions (or branches) of existing fields. Alternatively, these fields may be different from the existing fields, such as searchSpaceOtherSystemInformationReducedCapability (RedCap) and pagingSearchSpaceReducedCapability (RedCap), etc.

[0066] Additionally or alternatively, the cell-specific common parameters of the first initial BWP may include random access parameters used by at least a first type of UE for contention-based random access in the first initial UL BWP. These random access parameters may indicate, together with other parameters, for example, the total number of random access preambles, or the subcarrier spacing of the first message (Msg1), or both.

[0067] Similarly, the cell-specific common parameters of the second initial BWP may include random access parameters used by a second type of UE for contention-based random access in the first initial UL BWP. These random access parameters may indicate, together with other parameters, for example, the total number of random access preambles, or the subcarrier spacing of the first message (Msg1), or both. The random access parameters of the second initial BWP (e.g., their configured values or radio resources derived from the configured values) may be different from those of the first initial BWP. For example, the random access parameters of the second initial BWP may be configured such that they do not (exclusively) overlap with the random access parameters of the first initial BWP, or may partially overlap with the random access parameters of the first initial BWP.

[0068] Figure 2 An example showing the operations of gNB 1 and UE 2 is presented. In step 201, gNB 1 broadcasts the first initial BWP configuration via system information (e.g., SIB1). In step 202, gNB 1 broadcasts the second initial BWP configuration via system information (e.g., SIB1), or sends the second initial BWP configuration via UE-specific signaling (e.g., via an RRC message).

[0069] Here, it is assumed that UE 2 is a second type of UE. UE 2 receives the system information (e.g., SIB1) containing the first initial BWP configuration (step 201). Additionally, UE 2 receives the second initial BWP configuration via system information (e.g., SIB1) or via UE-specific signaling (step 202). Then, since UE 2 is a second type of UE, UE 2 uses the second initial BWP configuration.

[0070] From the above description, it can be understood that in this embodiment, gNB 1 configures a first initial BWP (i.e., the initial DL and UL BWP) and a second initial BWP (i.e., one or both of the initial DL and UL BWP) in cell 10. The first type of UE and the second type of UE use cell 10 as their serving cell and perform contention-based random access in cell 10. The second initial BWP is not used by the first type of UE but is used by the second type of UE. In addition, in addition to the first initial BWP configuration indicating the cell-specific common parameters of the first initial BWP of cell 10, gNB 1 also sends a second initial BWP configuration indicating the cell-specific common parameters of the second initial BWP of cell 10. The second type of UE selects and uses the second initial BWP. Therefore, this embodiment allows a second type of UE with limited capabilities compared to the first type of UE to use an initial BWP suitable for its capabilities in cell 10.

[0071] Second Embodiment

[0072] This embodiment provides a specific example of the transmission of the first initial BWP configuration and the second initial BWP configuration described in the first embodiment. An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1 the configuration shown.

[0073] In this embodiment, the gNB 1 broadcasts both the first initial BWP configuration and the second initial BWP configuration via system information (e.g., SIB1). If the UE 2 is a second type of UE, the UE 2 selects the second initial BWP configuration from the received system information and applies the selected second initial BWP configuration. The definitions and uses of the first initial BWP and the second initial BWP are similar to those of the first initial BWP and the second initial BWP in the example described in the first embodiment. The specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment.

[0074] Figure 3 An example of the operations of the gNB 1 and the UE 2 according to this embodiment is shown. Here, it is assumed that the UE 2 is a second type of UE. In step 301, the gNB 1 broadcasts both the first initial BWP configuration and the second initial BWP configuration via system information (e.g., SIB1). The second initial BWP configuration can be defined as a new branch of one or more of the ServingCellConfigCommonSIB information element, DownlinkConfigCommonSIB information element, BWP-DownlinkCommon information element, UplinkConfigCommonSIB information element, and BWP-UplinkCommon information element included in SIB1. In other words, a new version of these information elements can be specified, the new version of the information element contains at least a part of the configuration information (or parameters) included in these information elements, and the new version of the information element includes the configuration related to the second initial BWP configuration.

[0075] In step 302, if the UE 2 is a second type of UE, the UE 2 selects the second initial BWP configuration from the received system information and applies the selected second initial BWP configuration.

[0076] In steps 303 to 307, the UE 2 performs a random access procedure (4-step random access (RA)) by using the second initial BWP configuration and initiates an RRC setup procedure to transition from the RRC_IDLE state to the RRC_CONNECTED state.

[0077] In some implementations, the UE 2 may select the random access preamble transmitted in step 303 according to the random access parameters included in the second initial BWP configuration. For example, the UE 2 may transmit the random access preamble based on the configuration of the second initial UL BWP.

[0078] Additionally or alternatively, in step 304, the UE 2 may monitor the common search space configured by the PDCCH parameters included in the second initial BWP configuration to receive the DCI format indicating the PDSCH resource scheduling the random access response (Msg2). Additionally or alternatively, in step 304, the UE 2 may monitor the PDSCH resource configured by the PDSCH parameters included in the second initial BWP configuration to receive the random access response (Msg2) via the PDSCH.

[0079] Additionally or alternatively, in step 305, the UE 2 may transmit the third message (Msg3) (e.g., the initial RRC message (e.g., RRC setup request)) via the physical uplink shared channel (PUSCH) according to the physical uplink shared channel (PUSCH) parameters included in the second initial BWP configuration.

[0080] Additionally or alternatively, in step 306, the UE 2 may monitor the common search space configured by the PDCCH parameters included in the second initial BWP configuration to receive the DCI format indicating the PDSCH resource scheduling the fourth message (Msg4) for contention resolution (e.g., contention resolution MAC control element (CE) and RRC message (e.g., RRC setup)). Additionally or alternatively, in step 306, the UE 2 may monitor the PDSCH resource configured by the PDSCH parameters included in the second initial BWP configuration to receive the fourth message (Msg4) via the PDSCH. Then, in response to receiving the fourth message (Msg4) (or after receiving Msg4), the UE 2 may use the second initial BWP as the first active BWP.

[0081] Additionally or alternatively, in step 307, the UE 2 may transmit the fifth message (Msg5) (e.g., the RRC message (e.g., RRC setup complete) indicating the completion of the random access procedure (4-step RA)) via the PUSCH according to the PUSCH parameters included in the second initial BWP configuration.

[0082] Additionally or alternatively, the UE 2 may monitor the PDSCH resource configured by the PDSCH parameters included in the second initial BWP configuration to receive DL signaling and DL RRC messages that occur later than the RRC setup message in step 306 on the PDSCH.

[0083] Although Figure 3 An example of RRC setup (or RRC establishment) is shown, but the transmission of the second initial BWP configuration via system information can also be used for RRC resume (Msg3: RRC resume request, Msg4: RRC resume, and Msg5: RRC resume complete) and for RRC re - establishment (Msg3: RRC re - establishment request, and Msg4: RRC re - establishment).

[0084] According to Figure 3 the process shown, gNB 1 applies the second initial BWP configuration to the second type of UE via system information. Thus, the second type of UE can use the second initial BWP configuration before starting the random access process.

[0085] In Figure 3 the process shown, the second initial BWP configuration broadcast in step 301 may imply the support for the second type of UE (e.g., UE with reduced capabilities) in cell 10. If the second initial BWP configuration cannot be received in the cell, the second type of UE can recognize that access to the cell is prohibited.

[0086] In Figure 3 the transmission of step 305 in, UE 2 can indicate a specific logical channel ID (LCID) associated with the second type of UE (e.g., UE with reduced capabilities) to gNB 1. Based on the reception of this specific LCID, gNB 1 can identify (or detect) that UE 2 is the second type of UE. Additionally or alternatively, in Figure 3 the transmission of step 307 in, UE 2 can include an indication in the RRC setup complete message indicating that it is the second type of UE. Based on the reception of this indication, gNB 1 can identify (or detect) that UE 2 is the second type of UE. Additionally or alternatively, in or after step 305, gNB1 can receive UE capability information from UE 2 or the core network (e.g., the access and mobility management function (AMF) in the 5G core network (5GC)), and identify (or detect) that UE 2 is the second type of UE based on the UE capability information. In response to detecting that UE 2 is the second type of UE, gNB 1 can send UE - specific configuration (including dedicated BWP configuration) specific to the capabilities of UE 2 to UE 2 via dedicated signaling (e.g., RRC re - configuration message).

[0087] Figure 4 Another example of the operations of gNB 1 and UE 2 according to this embodiment is shown. Here it is assumed that UE2 is the second type of UE. Figure 4 The example of Figure 3The example is different in that it performs a two-step random access procedure (2-step RA) instead of a four-step random access procedure (4-step RA). Similar to Figure 3 In step 401, similar to step 301 in , gNB 1 broadcasts both the first initial BWP configuration and the second initial BWP configuration via system information (e.g., SIB1).

[0088] In step 402, if UE 2 is a second type of UE, UE 2 selects the second initial BWP configuration from the received system information and applies the selected second initial BWP configuration.

[0089] In steps 403 to 405, UE 2 performs a two-step random access procedure (2-step RA) by using the second initial BWP configuration and initiates an RRC setup procedure to transition from the RRC_IDLE state to the RRC_CONNECTED state.

[0090] In some implementations, UE 2 may select the random access preamble of the two-step RACH message A (MsgA) sent in step 403 according to the random access parameters included in the second initial BWP configuration. For example, UE 2 may send the random access preamble based on the configuration of the second initial UL BWP. Additionally or alternatively, in step 403, UE 2 may send the data part (or payload) of the two-step RA message A (MsgA) (e.g., the initial RRC message (e.g., RRC setup request)) according to the physical uplink shared channel (PUSCH) parameters included in the second initial BWP configuration.

[0091] Additionally or alternatively, in step 404, UE 2 may monitor the common search space configured by the PDCCH parameters included in the second initial BWP configuration to receive the DCI format indicating the PDSCH resources for the random access response (message B (MsgB)) scheduling the two-step RA (e.g., the contention resolution MAC CE and the RRC message (e.g., RRC setup)). Additionally or alternatively, in step 404, UE 2 may monitor the PDSCH resources configured by the PDSCH parameters included in the second initial BWP configuration to receive the two-step RA random access response (MsgB) via the PDSCH.

[0092] Additionally or alternatively, in step 405, UE 2 may send an RRC message (e.g., RRC setup complete) indicating the completion of the two-step random access procedure via the PUSCH according to the PUSCH parameters included in the second initial BWP configuration.

[0093] Although Figure 4An example of RRC setup (or RRC establishment) is shown, but the transmission via the second initial BWP configuration of the system information can also be used for RRC resume and RRC re - establishment.

[0094] Third Embodiment

[0095] This embodiment provides a specific example of the transmission of the first initial BWP configuration and the second initial BWP configuration described in the first embodiment. An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1 the configuration of the radio communication network shown. The definition and use of the first initial BWP and the second initial BWP in this embodiment are similar to the definition and use of the first initial BWP and the second initial BWP in the example described in the first embodiment. The specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment.

[0096] In this embodiment, gNB 1 broadcasts the first initial BWP configuration via the system information (e.g., SIB1), and gNB 1 sends the second initial BWP configuration to the second type of UE via an RRC message (e.g., RRC setup) during the contention - based random access (CBRA) procedure. If UE 2 is the second type of UE, UE 2 receives the first initial BWP configuration via the system information (e.g., SIB1), and receives the second initial BWP configuration via an RRC message (e.g., RRC setup) during the CBRA procedure. In response to receiving the second initial BWP configuration, UE 2 applies the second initial BWP configuration instead of the first initial BWP configuration (i.e., updates the used initial BWP configuration).

[0097] Figure 5 An example of the operations of gNB 1 and UE 2 according to this embodiment is shown. Here, it is assumed that UE 2 is the second type of UE. In step 501, gNB 1 broadcasts the first initial BWP configuration via the system information (e.g., SIB1). gNB 1 also broadcasts via the system information the random access channel (RACH) configuration used by the second type of UE in the random access procedure (4 - step RA). The RACH configuration indicates the specific RACH resources (i.e., preambles or timing or both) for the second type of UE. The broadcast of the RACH configuration means the support for the second type of UE (e.g., reduced - capability UE) in cell 10.

[0098] In step 502, UE 2 receives system information from gNB 1 and applies the received first initial BWP configuration. In step 503, UE 2 selects a RACH resource based on the random access channel (RACH) configuration for the second type of UE and sends a random access preamble to gNB 1. In response to the random access preamble, gNB 1 detects the access from the second type of UE. In step 504, gNB 1 sends a random access response (Msg2). In step 505, UE 2 sends a third message (Msg3) (e.g., an initial RRC message (e.g., RRC setup request)) to gNB 1.

[0099] In step 506, gNB 1 sends a fourth message (Msg4) (e.g., a contention resolution MAC CE for contention resolution, and an RRC setup message) to UE 2. The RRC setup message includes a second initial BWP configuration. Specifically, if gNB 1 identifies (or detects) UE 2 as the second type of UE via the RACH resource (step 503), gNB 1 includes the second initial BWP configuration in the RRC setup message. In step 507, in response to receiving the second initial BWP configuration, UE 2 applies the second initial BWP configuration to replace the first initial BWP configuration (i.e., updates the used initial BWP configuration). Then, in response to receiving the fourth message (Msg4) (or after receiving Msg4), UE 2 can use the second initial BWP as the first active BWP. In step 508, UE 2 sends an RRC setup complete message to gNB1 according to the second initial BWP configuration.

[0100] The procedures in Figure 5 can be modified appropriately. For example, Figure 5 the procedures in

[0101] Figure 6 can be modified to perform a two-step random access procedure (2-step RA) instead of a four-step random access procedure (4-step RA). In this case, gNB 1 can send an RRC message (e.g., RRC setup) including the second initial BWP configuration as the random access response (message B (MsgB)) of the 2-step RA. Figure 6 The difference between the procedures in Figure 5 and the procedures in

[0102] In step 601, gNB 1 broadcasts the first initial BWP configuration via system information (e.g., SIB1). gNB 1 also broadcasts an indication of support for a second type of UE via system information. In step 602, UE 2 receives the system information from gNB 1 and applies the received first initial BWP configuration. In step 603, UE 2 sends a random access preamble to gNB 1. In step 604, gNB 1 sends a random access response (Msg2). In step 605, UE 2 sends a third message (Msg3) (e.g., an initial RRC message (e.g., RRC setup request)) to gNB 1. In the transmission of step 605, UE 2 indicates to gNB 1 a specific logical channel ID (LCID) associated with the second type of UE (e.g., a reduced-capability UE). The specific LCID can be, for example, a predefined LCID to be used for the common control channel (CCCH). Based on the reception of the specific LCID, gNB 1 identifies (or detects) that UE 2 is a second type of UE.

[0103] In step 606, gNB 1 sends a fourth message (Msg4) (e.g., a contention resolution MAC CE for contention resolution, and an RRC setup message) to UE 2. The RRC setup message includes a second initial BWP configuration. Specifically, if gNB 1 identifies (or detects) that UE 2 is a second type of UE via a specific LCID associated with the second type of UE, then gNB1 includes the second initial BWP configuration in the RRC setup message. In step 607, in response to receiving the second initial BWP configuration, UE2 applies the second initial BWP configuration to replace the first initial BWP configuration (i.e., updates the initial BWP configuration being used). In step 608, UE 2 sends an RRC setup complete message to gNB 1 according to the second initial BWP configuration.

[0104] The procedures in Figure 6 can be modified appropriately. For example, Figure 6 the procedures in

[0105] can be modified to perform a two-step random access procedure (2-step RA) instead of a four-step random access procedure (4-step RA). In this case, gNB 1 can send an RRC message (e.g., RRC setup) including the second initial BWP configuration as the random access response (message B (MsgB)) of the 2-step RA.

[0105] It should be noted that in step 506 of Figure 5 and Figure 6The second initial BWP configuration sent to UE 2 in step 606 is a cell-specific common configuration of the initial BWP, rather than a UE-specific dedicated configuration. This second initial BWP configuration includes a cell-specific common configuration of the second initial BWP corresponding to (at least a part of) the cell-specific common configuration of the first initial BWP. In other words, this second initial BWP configuration is sent by a UE-specific RRC message in Figure 5 step 506 and Figure 6 step 606, but is not a UE-specific dedicated configuration. The second initial BWP configuration sent in steps 506 and 606 includes cell-specific common parameters of the initial BWP. Specifically, this second initial BWP configuration may include parameters indicating the frequency-domain position and bandwidth of the initial DL BWP, or the frequency-domain position and bandwidth of the initial UL BWP, or both. Additionally or alternatively, this second initial BWP configuration may include a configuration of the Type0-PDCCH common search space set (search space #0) in the initial DL BWP. The Type0-PDCCH common search space set (search space #0) is monitored to receive Type0-PDCCH for SIB1 decoding.

[0106] When UE 2 has transitioned from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state after receiving the second initial BWP configuration, UE 2 may retain the second initial BWP configuration and continue to use the second initial BWP configuration. For example, UE 2 may continue to use the second initial BWP configuration while staying in the same cell 10. Additionally, when UE 2 initiates an RRC setup or RRC resume procedure again in the same cell 10 to transition from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state, UE 2 may use the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1 to access cell 10. UE 2 may perform these operations only when it has received information explicitly or implicitly indicating permission to perform these operations from gNB 1 via an RRC message (e.g., RRC setup, RRC reconfiguration, or RRC release) or SIB1.

[0107] Additionally or alternatively, if a new cell different from cell 10 supports the second type of UE, UE 2 may use the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1 of this new cell to access this new cell. UE 2 may perform these operations only when it has received information explicitly or implicitly indicating permission to perform these operations from gNB 1 via an RRC message or SIB1.

[0108] Fourth Embodiment

[0109] This embodiment provides a specific example of the transmission of the first initial BWP configuration and the second initial BWP configuration described in the first embodiment. An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1 the configuration of the radio communication network shown. The definition and use of the first initial BWP and the second initial BWP in this embodiment are similar to the definition and use of the first initial BWP and the second initial BWP in the example described in the first embodiment. The specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment.

[0110] In this embodiment, the gNB 1 broadcasts the first initial BWP configuration via system information (e.g., SIB1), and sends the second initial BWP configuration to the UE 2 via an RRC reconfiguration message after the RRC (connection) setup of the UE 2 is completed. If the UE 2 is a second type of UE, the UE 2 receives the first initial BWP configuration via system information (e.g., SIB1), and receives the second initial BWP configuration via an RRC reconfiguration message after the RRC setup is completed. In response to receiving the second initial BWP configuration, the UE2 applies the second initial BWP configuration to replace the first initial BWP configuration (i.e., updates the initial BWP configuration used).

[0111] Figure 7 An example of the operations of the gNB 1 and the UE 2 according to this embodiment is shown. Here, it is assumed that the UE 2 is a second type of UE. In step 701, the gNB 1 broadcasts the first initial BWP configuration via system information (e.g., SIB1). The gNB 1 also broadcasts an indication via the system information indicating support for the second type of UE.

[0112] Steps 702 to 707 are similar to the normal contention-based random access (CBRA) and RRC setup procedures. Specifically, in step 702, the UE 2 receives the system information from the gNB 1 and applies the received first initial BWP configuration. In step 703, the UE 2 sends a random access preamble to the gNB 1. In step 704, the gNB 1 sends a random access response (Msg2). In step 705, the UE 2 sends a third message (Msg3) (e.g., an initial RRC message (e.g., an RRC setup request)) to the gNB 1. In step 706, the gNB 1 sends a fourth message (Msg4) for contention resolution (e.g., a contention resolution MAC CE for contention resolution, and an RRC setup message) to the UE 2. In step 707, the UE 2 sends an RRC setup completion message to the gNB 1.

[0113] In step 708, gNB 1 obtains the UE capability information of UE 2 from UE 2 or the core network (e.g., the AMF in 5GC). gNB 1 identifies (or detects) that UE 2 is a second type of UE based on the obtained UE capability information. In response to identifying (or detecting) that UE 2 is a second type of UE, gNB 1 generates an RRC reconfiguration message including the second initial BWP configuration. In step 709, gNB 1 sends the RRC reconfiguration message including the second initial BWP configuration to UE 2. In step 710, in response to receiving the second initial BWP configuration, UE 2 applies the second initial BWP configuration to replace the first initial BWP configuration (i.e., updates the used initial BWP configuration).

[0114] The procedures shown in Figure 7 can be modified appropriately. For example, Figure 7 the procedures shown in

[0115] can be modified to perform a two-step random access procedure (2-step RA) instead of a four-step random access procedure (4-step RA).

[0116] When the UE 2 has transitioned from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state after receiving the second initial BWP configuration, the UE 2 may maintain the second initial BWP configuration and continue to use the second initial BWP configuration. For example, the UE 2 may continue to use the second initial BWP configuration while staying in the same cell 10. In addition, when the UE 2 initiates an RRC setup or RRC resume procedure again in the same cell 10 to transition from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state, the UE 2 may use the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1 to access the cell 10. The UE 2 may perform these operations only when the UE 2 has received information indicating permission to perform these operations explicitly or implicitly from the gNB 1 via an RRC message (e.g., RRC setup, RRC reconfiguration, or RRC release) or SIB1.

[0117] Additionally or alternatively, if a new cell different from cell 10 supports the second type of UE, the UE 2 may use the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1 of the new cell to access the new cell. The UE 2 may perform these operations only when the UE 2 has received information indicating permission to perform these operations explicitly or implicitly from the gNB 1 via an RRC message or SIB1.

[0118] Fifth Embodiment

[0119] An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1 the configuration of the radio communication network shown. The definitions and uses of the first initial BWP and the second initial BWP in this embodiment are similar to the definitions and uses of the first initial BWP and the second initial BWP in the example described in the first embodiment. Specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment. This embodiment provides specific examples of the operations of the UE 2 described in the third embodiment and the fourth embodiment.

[0120] Figure 8 An example showing the operation of the UE 2 according to this embodiment is shown. In step 801, the UE 2 receives a second initial BWP configuration including cell-specific common parameters from the gNB 1 via dedicated RRC signaling. Step 801 is similar to Figure 5 step 506 in Figure 6 step 606 in Figure 7Step 709 in []. In step 802, UE 2 applies the received second initial BWP configuration. In step 803, UE 2 transitions from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state.

[0121] In step 804, when UE 2 is in the RRC_IDLE or RRC_INACTIVE state after receiving the second initial BWP configuration, UE 2 maintains the second initial BWP configuration and continues to use the second initial BWP configuration. For example, UE 2 can continue to use the second initial BWP configuration while staying in the same cell 10. Additionally, when UE 2 initiates an RRC setup or RRC resume procedure again in the same cell 10 to transition from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state, UE 2 can use the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1 to access cell 10. UE 2 can perform these operations only if UE 2 has received information indicating permission to perform these operations explicitly or implicitly from gNB 1 via an RRC message (e.g., RRC setup, RRC reconfiguration, or RRC release) or SIB1.

[0122] Additionally or alternatively, if a new cell different from cell 10 supports the second type of UE, UE 2 can use the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1 of the new cell to access the new cell. UE 2 can perform these operations only if UE 2 has received information indicating permission to perform these operations explicitly or implicitly from gNB 1 via an RRC message or SIB1.

[0123] According to Figure 8 the operations shown, when transitioning again from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state, the second type of UE can use the second initial BWP configuration that it has received when it was previously in the RRC_CONNECTED state.

[0124] Sixth Embodiment

[0125] An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1Configuration of the radio communication network shown. The definitions and uses of the first initial BWP and the second initial BWP in this embodiment are similar to those of the first initial BWP and the second initial BWP in the example described in the first embodiment. Specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment. This embodiment provides specific examples of the operations of gNB 1 and UE 2 described in the third embodiment and the fourth embodiment.

[0126] In this embodiment, the RAN including gNB 1 defines a cell or area as follows: Even after UE 2 transitions from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state, UE 2 is allowed to continue using the second initial BWP received when UE 2 was in the RRC_CONNECTED state.

[0127] Figure 9 An example of the operation of gNB 1 according to this embodiment is shown. When gNB 1 releases the RRC connection with UE 2, gNB 1 sends RAN area information to UE 2, which indicates the cell or area where UE 2 is allowed to continue using the second initial BWP configuration even after UE 2 transitions from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state (step 901). gNB 1 may include this RAN area information in the RRC release message (e.g., SuspendConfig in the RRC release message). Other RRC messages (e.g., RRC reconfiguration) may be used instead of the RRC release message. The RAN area information may indicate a list of cells or a list of RAN area codes. In this case, a new RAN area code (ranac) may be defined as ranac-ReducedCapability (RedCap). If the RAN area information indicates the cell or area where continued use of the second initial BWP is allowed in the RRC_INACTIVE state, the configuration of the RAN notification area (RNA) may be reused. In this case, this RNA may be newly defined as RNA-ReducedCapability (RedCap).

[0128] Figure 10 An example of the operation of RAN 4 according to this embodiment is shown. gNB 1 belonging to RAN 4 and other gNBs supporting the second type of UE broadcast the RAN area code for continued use of the second initial BWP configuration via system information (e.g., SIB1) (step 1001).

[0129] Figure 11An example of the operation of UE 2 according to this embodiment is shown. In step 1101, when UE 2 is in the RRC_CONNECTED state, it receives the second initial BWP configuration and the RAN area code list, and then transitions from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state. The RAN area code list indicates one or more RAN area codes representing one or more RAN areas where it is allowed to continue using the second initial BWP configuration. UE 2 stores and maintains the second initial BWP configuration and the RAN area code list in the memory.

[0130] In step 1102, when UE 2 is in the RRC_IDLE or RRC_INACTIVE state, it receives SIB1 of the new cell. The new cell may be provided by the same gNB 1 as that of cell 10, or may be provided by another gNB.

[0131] In step 1103, UE 2 determines whether the SIB1 received from the new cell indicates one of the one or more stored RAN area codes. If the SIB1 of the new cell indicates one of the stored RAN area codes, UE 2 continues to use the stored second initial BWP configuration in the new cell. For example, when UE 2 initiates an RRC setup or RRC resume procedure again in the new cell to transition from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state, UE 2 accesses the new cell by using the stored second initial BWP configuration instead of using the first initial BWP configuration broadcast via SIB1.

[0132] Figure 11 The process shown can be modified as follows. In step 1101, UE 2 may receive a list of one or more cells that allow continued use of the second initial BWP configuration. In this case, UE 2 may determine in step 1103 whether the new cell is included in the list based on the SIB1 received from the new cell.

[0133] According to this embodiment, if UE 2 transitions from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state after receiving the second initial BWP configuration when it is in the RRC_CONNECTED state, UE 2 may continue to use the second initial BWP configuration.

[0134] Seventh Embodiment

[0135] An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1Configuration of the radio communication network shown. The definition and use of the first initial BWP and the second initial BWP in this embodiment are similar to the definition and use of the first initial BWP and the second initial BWP in the example described in the first embodiment. Specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment.

[0136] As described in the second and third embodiments, the UE 2 may indicate a specific logical channel ID (LCID) associated with a second type of UE (e.g., a UE with reduced capabilities) to the gNB 1 when sending a third message (Msg3) (e.g., an RRC setup request) during a random access procedure (e.g., an RRC setup procedure). Alternatively, the UE 2 may use a RACH resource associated with the second type of UE in the transmission of a random access preamble (Msg1) during the random access procedure.

[0137] In the case of RRC resume (or RRC connection resume procedure), the UE 2 may not use the indication of the second UE via the RACH resource or the LCID. This is because the gNB 1 may obtain the UE context stored in the gNB 1 or another gNB (e.g., the gNB that moved the UE 2 to the RRC_INACTIVE state) and determine whether the UE 2 is a second type of UE based on this UE context. However, if the RRC resume of the UE 2 fails (e.g., because the gNB 1 fails to successfully obtain the UE context), the gNB 1 may fallback to the setup of a new RRC connection and send an RRC setup message to the UE 2 to establish a new RRC connection. In this case, the gNB 1 may not be able to determine whether the UE 2 is a second type of UE.

[0138] A similar problem may also occur in RRC reestablishment (or RRC connection reestablishment procedure). This is because, in the case of RRC reestablishment, the gNB 1 may use the UE context stored in the gNB 1 and determine whether the UE 2 is a second type of UE based on this UE context. However, if the RRC reestablishment of the UE 2 fails, the gNB 1 may fallback to the setup of a new RRC connection and send an RRC setup message to the UE 2 to establish a new RRC connection. In this case, the gNB 1 may not be able to determine whether the UE 2 is a second type of UE.

[0139] To solve these problems, although UE2 has initiated an RRC connection restoration procedure or an RRC connection re - establishment procedure, in response to receiving an RRC setup message for establishing a new RRC connection from the network (gNB), UE 2 according to this embodiment sends an RRC setup complete message including a second type of indication (e.g., an indication of limited capability) to the network (gNB). This allows UE 2 to notify the network that UE 2 is a second - type UE when the network (gNB) falls back from RRC restoration or RRC re - establishment to RRC connection establishment.

[0140] Figure 12 An example showing the operations of gNB 1 and UE 2 is presented. In step 1201, UE 2 sends an RRC restoration request message or an RRC re - establishment request message to gNB 1. In step 1202, gNB 1 determines to fall back to the establishment of a new RRC connection. In step 1203, in response to this fallback, gNB 1 sends an RRC setup message to UE 2 instead of an RRC restoration message and an RRC re - establishment message. In step 1204, UE 2 sends an RRC setup complete message including a second type of indication (e.g., an indication of limited capability) to gNB 1.

[0141] Eighth Embodiment

[0142] An example of the configuration of the radio communication network according to this embodiment is similar to Figure 1 the configuration of the radio communication network shown. The definitions and uses of the first initial BWP and the second initial BWP in this embodiment are similar to the definitions and uses of the first initial BWP and the second initial BWP in the example described in the first embodiment. The specific examples of the first initial BWP configuration and the second initial BWP configuration are also similar to the examples described in the first embodiment.

[0143] In this embodiment, a Cloud RAN (C - RAN) deployment is applied to gNB 1. In C - RAN, gNB1 is composed of a Central Unit (CU) and one or more Distributed Units (DUs). C - RAN is also known as a centralized RAN and a CU - DU separation architecture.

[0144] Figure 13 An example showing the configuration of gNB 1 according to this embodiment is presented. Figure 13 The gNB 1 shown includes a CU 11 and one or more DUs 12. The CU 11 is connected to each DU 12 via an interface 1301 (i.e., the F1 interface). UE 2 is connected to at least one DU 12 via at least one air interface 1302.

[0145] The CU 11 may be a logical node that hosts the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols (or the RRC and PDCP protocols of the gNB). The CU 11 may include a Control Plane (CP) unit (i.e., gNB-CU-CP) and one or more User Plane (UP) units (i.e., gNB-CU-UP). Each DU 12 may be a logical node that hosts the Radio Link Control (RLC), Media Access Control (MAC), and Physical (PHY) layers of the gNB 1.

[0146] As described in the third embodiment, the UE 2 may notify the gNB 1 that the UE 2 is a second type of UE via the RACH resource associated with the second type of UE ( Figure 5 step 503 in) or via the LCID specific to the second type of UE ( Figure 6 step 605 in). As Figure 13 shown, when the gNB 1 includes the CU 11 and one or more DUs 12, one of the DUs 12 performs RACH resource detection and LCID detection, and the CU 11 generates an RRC setup message containing the second initial BWP configuration ( Figure 5 step 506 in, or Figure 6 step 606 in). Therefore, signaling between the CU 11 and the DU 12 is required to achieve this.

[0147] Figure 14 An example of the signaling between the CU 11 and the DU 12 is shown. In step 1401, the DU 12 detects that the UE 2 is a second type of UE via the RACH resource associated with the second type of UE (e.g., Figure 5 step 503 in) or via the LCID specific to the second type of UE (e.g., Figure 6 step 605 in).

[0148] In step 1402, DU 12 sends an F1AP message (i.e., INITIAL UL RRC MESSAGE TRANSFER message) containing the initial RRC message (e.g., RRC setup request) received from UE 2 to CU 11. DU 12 includes an indication in the INITIAL UL RRC MESSAGE TRANSFER message indicating that UE2 is a second type of UE. This indication can be, for example, an indication of limited capability. This indication can be defined as a new information element in the F1AP: INITIAL UL RRC MESSAGE TRANSFER message (e.g., reduced capability indication information element (IE)). Alternatively, this indication can be included in the DU-to-CU RRC container IE in the F1AP: INITIAL UL RRC MESSAGE TRANSFER message. More specifically, this indication can be defined as a new IE in the DU-to-CU RRC container IE, or as a new IE or field included in the CellGroupConfig IE within the DU-to-CU RRC container IE.

[0149] In response to receiving the F1AP: INITIAL UL RRC MESSAGE TRANSFER message (step 1402), CU 11 receives the RRC setup request message from UE 2 and identifies that UE 2 is a second type of UE. In step 1403, CU 11 generates an RRC setup message containing the second initial BWP configuration and sends an F1AP message (i.e., DL RRC MESSAGE TRANSFER message) containing the RRC setup message to DU 12. In response to receiving the DL RRC MESSAGE TRANSFER message (step 1403), DU 12 sends the RRC setup message containing the second initial BWP configuration to UE 2.

[0150] Figure 15 Another example showing the signaling between CU 11 and DU 12. Step 1501 is similar to Figure 14Step 1401 in []. In step 1502, DU 12 sends an F1AP message (i.e., INITIAL UL RRC MESSAGE TRANSFER message) containing the initial RRC message (e.g., RRC setup request) received from UE 2 to CU 11. DU 12 includes an indication in the INITIAL UL RRC MESSAGE TRANSFER message indicating that UE 2 is a second type of UE. This indication can be, for example, an indication of limited capability. In addition, DU 12 generates a second initial BWP configuration and includes it in the INITIAL UL RRC MESSAGE TRANSFER message. Specifically, DU 12 can generate a CellGroupConfig containing the second initial BWP configuration and include it in the DU-to-CU RRC container IE in the INITIAL UL RRC MESSAGE TRANSFER message.

[0151] In response to receiving the F1AP: INITIAL UL RRC MESSAGE TRANSFER message (step 1502), CU 11 receives the RRC setup request message from UE 2 and identifies that UE 2 is a second type of UE. In addition, CU 11 receives the second initial BWP configuration generated by DU 12 (e.g., a CellGroupConfig containing the second initial BWP configuration). In step 1503, CU 11 generates an RRC setup message containing the second initial BWP configuration and sends an F1AP message (i.e., DL RRC MESSAGE TRANSFER message) containing the RRC setup message to DU 12. In response to receiving the DL RRC MESSAGE TRANSFER message (step 1503), DU 12 sends the RRC setup message containing the second initial BWP configuration to UE 2.

[0152] Additionally or alternatively, the DU 12 may notify the CU 11 of the second initial BWP configuration information (second initial BWP configuration) via an F1 SETUP REQUEST message or a gNB-DU CONFIGURATION UPDATE message, and the CU 11 may store the received second initial BWP configuration information. When the UE 2 accesses the CU 11 via the DU 12 and the CU 11 recognizes that the UE 2 is a UE with reduced capabilities based on the UE capabilities of the UE 2, the CU 11 may send the stored second initial BWP configuration information to the UE 2 via the DU 12. Alternatively, the DU 12 may send the second initial BWP configuration information to the CU 11 in another F1AP procedure. The F1AP procedure may be, for example, a UE-related F1AP procedure or a non-UE-related F1AP procedure associated with a specific UE.

[0153] The following provides a configuration example of the gNB 1 and the UE 2 according to the above embodiments. Figure 16 is a block diagram showing a configuration example of the gNB 1 according to the above embodiments. As Figure 16 shown, the gNB 1 includes a radio frequency (RF) transceiver 1601, a network interface 1603, a processor 1604, and a memory 1605. The RF transceiver 1601 performs analog RF signal processing to communicate with a UE including the UE 2. The RF transceiver 1601 may include a plurality of transceivers. The RF transceiver 1601 is connected to an antenna array 1602 and a processor 1604. The RF transceiver 1601 receives modulated symbol data from the processor 1604, generates a transmission RF signal, and supplies the generated transmission RF signal to the antenna 1602. In addition, the RF transceiver 1601 generates a baseband received signal based on the received RF signal received by the antenna 1602 and supplies the signal to the processor 1604. The RF transceiver 1601 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, a plurality of phase shifters and a plurality of power amplifiers.

[0154] The network interface 1603 is used to communicate with network nodes (e.g., other gNBs, AMF, session management function (SMF), and user plane function (UPF)). The network interface 1603 may include a network interface card (NIC) compliant with the IEEE 802.3 series.

[0155] Processor 1604 performs digital baseband signal processing (i.e., data plane processing) and control plane processing for radio communication. Processor 1604 may include multiple processors. Processor 1604 may include a modem processor (e.g., a digital signal processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., a central processing unit (CPU) or a microprocessing unit (MPU)) that performs control plane processing.

[0156] For example, the digital baseband signal processing performed by processor 1604 may include signal processing in the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer. In addition, the control plane processing performed by processor 1604 may include the processing of non-access stratum (NAS) messages, RRC messages, MAC CE, and DCI.

[0157] Processor 1604 may include a digital beamformer module for beamforming. The digital beamformer module may include a multi-input multi-output (MIMO) encoder and a MIMO precoder.

[0158] Memory 1605 is a volatile memory, a non-volatile memory, or a combination thereof. The volatile memory is, for example, a static random access memory (SRAM), a dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is, for example, a mask read-only memory (MROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a hard disk drive, or any combination thereof. Memory 1605 may include a storage device located separately from processor 1604. In this case, processor 1604 may access memory 1605 through network interface 1603 or an I / O interface (not shown).

[0159] Memory 1605 may store one or more software modules (computer programs) 1606, which include a set of instructions and data for performing the processing performed by gNB 1 described in the above embodiments. In some implementations, processor 1604 may load software module 1606 from memory 1605 and execute the loaded software module to perform the processing of gNB 1 described in the above embodiments.

[0160] Note that when gNB 1 is a gNB-CU, gNB 1 may not include RF transceiver 1601 (and antenna array 1602).

[0161] Figure 17It is a block diagram showing an example of the configuration of UE 2. The radio frequency (RF) transceiver 1701 performs analog RF signal processing to communicate with the NG-RAN node. The RF transceiver 1701 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 1701 includes upconversion, downconversion, and amplification. The RF transceiver 1701 is connected to the antenna array 1702 and the baseband processor 1703. The RF transceiver 1701 receives modulated symbol data (OFDM symbol data) from the baseband processor 1703, generates a transmission RF signal, and supplies the generated transmission RF signal to the antenna 1702. In addition, the RF transceiver 1701 generates a baseband reception signal based on the received RF signal received by the antenna 1702 and supplies the signal to the baseband processor 1703. The RF transceiver 1701 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0162] The baseband processor 1703 performs digital baseband signal processing (data plane processing) and control plane processing for radio communication. The digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / cascading, (c) synthesis / decomposition of the transmission format (i.e., the transmission frame), (d) channel coding / decoding, (e) modulation (i.e., symbol mapping) / demodulation, and (f) generation of OFDM symbol data (i.e., the baseband OFDM signal) through the inverse fast Fourier transform (IFFT). On the other hand, the control plane processing includes communication management of layer 1 (e.g., transmission power control), layer 2 (e.g., radio resource management and hybrid automatic repeat request (HARQ) processing), and layer 3 (e.g., signaling regarding attachment, mobility, and paging management).

[0163] The digital baseband signal processing performed by the baseband processor 1703 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 media access control (MAC) layer, and the physical (PHY) layer. In addition, the control plane processing performed by the baseband processor 1703 may include processing of the non-access stratum (NAS) protocol, the radio resource control (RRC) protocol, and the MAC control element (CE).

[0164] The baseband processor 1703 may perform multi-input multi-output (MIMO) coding and precoding for beamforming.

[0165] The baseband processor 1703 may include a modem processor (e.g., a digital signal processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., a central processing unit (CPU) or a microprocessing unit (MPU)) that performs control plane processing. In this case, the protocol stack processor that performs control plane processing may be integrated with the application processor 1704 described below.

[0166] The application processor 1704 is also referred to as a CPU, MPU, microprocessor, or processor core. The application processor 1704 may include multiple processors (or multiple processor cores). The application processor 1704 loads system software programs (operating systems (OS)) and various application programs (e.g., paging applications, WEB browsers, mail programs, camera operation applications, and music player applications) from the memory 1706 or from another memory (not shown), and executes these programs, thereby providing various functions of the UE 2.

[0167] In some implementations, as Figure 17 indicated by the dashed line (1705) in

[0168] The memory 1706 is a volatile memory, a non-volatile memory, or a combination thereof. The memory 1706 may include multiple memory devices that are physically independent of each other. The volatile memory is, for example, a static random access memory (SRAM), a dynamic RAM (DRAM), or a combination thereof. The memory 1706 may include, for example, an external memory device that can be accessed from the baseband processor 1703, the application processor 1704, and the SoC 1705. The memory 1706 may include an internal memory device integrated in the baseband processor 1703, the application processor 1704, or the SoC 1705. In addition, the memory 1706 may include a memory in a universal integrated circuit card (UICC).

[0169] The memory 1706 may store one or more software modules (computer programs) 1707, and the software modules 1707 include sets of instructions and data for performing the processing of the UE 2 described in the above multiple embodiments. In some implementations, the baseband processor 1703 or the application processor 1704 may load these software modules 1707 from the memory 1706 and execute the loaded software modules, thereby performing the processing of the UE 2 described in the above embodiments with reference to the accompanying drawings.

[0170] The control plane processing and operations performed by the UE 2 described in the above embodiments may be implemented by elements other than the RF transceiver 1701 and the antenna array 1702, that is, by the memory 1706 storing the software module 1707, and one or both of the baseband processor 1703 and the application processor.

[0171] As referred to above Figure 16 and Figure 17 described, each processor included in the gNB 1 and the UE 2 in the above embodiments executes one or more programs including a set of instructions that cause a computer to perform the algorithms described above with reference to the drawings. These programs may be stored in various types of non-transitory computer-readable media and thus supplied to the computer. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (such as floppy disks, magnetic tapes, and hard disk drives), magneto-optical recording media (such as magneto-optical disks), compact disk read-only memory (CD-ROM), CD-R, CD-R / W, and semiconductor memories (such as mask ROM, programmable ROM (PROM), erasable PROM (EPROM), flash ROM, and random access memory (RAM)). These programs may be supplied to the computer by using various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer-readable media can be used to supply programs to the computer via wired communication lines (such as wires and optical fibers) or wireless communication lines.

[0172] Other embodiments

[0173] The above embodiments may be implemented independently of each other, or may be implemented by appropriately combining all or part of two or more of the embodiments.

[0174] In the above embodiments, if the UE 2 is a second type of UE, the UE 2 may select whether to use the first initial BWP or the second initial BWP. For example, if the UE 2 supports the first initial BWP (e.g., the bandwidth of the first initial BWP) (i.e., has the ability to communicate on the first initial BWP), the UE 2 may select the first initial BWP and apply the first initial BWP configuration. On the other hand, if the UE 2 does not support the first initial BWP (e.g., the bandwidth of the first initial BWP) (i.e., does not have the ability to communicate on the first initial BWP), the UE 2 may select the second initial BWP and apply the second initial BWP configuration. The UE 2 may perform this operation in a band-related manner. This operation may be specified in the 3GPP specifications.

[0175] When the UE 2 performs a handover (also referred to as reconfiguration with Sync), the second initial BWP configuration in the above embodiments can be applied. In a handover, an RRC reconfiguration message is sent from the target gNB managing the target cell, via the source gNB managing the source cell, to the UE 2. This RRC reconfiguration message contains cell common configuration information (e.g., ServingCellConfigCommon information element) to be used by the UE 2 in the target cell. This cell common configuration information includes a downlinkConfigCommon information element, which contains frequency information and cell common initial DL BWP configuration information (e.g., initial downlink BWP common configuration). The existing downlinkConfigCommon information element indicates parameters that match the parameters configured in the MIB and SIB1. For example, the configuration of the initial DL BWP that is the same as the configuration of the initial DL BWP configured in the SIB1 of the target cell is sent to the UE via the RRC reconfiguration message. This allows, for example, a UE moving to (entering) the target cell via a handover and a UE transitioning from the RRC_IDLE state to the RRC_CONNECTED state via an RRC (connection) setup procedure to communicate using the same radio resource configuration. In contrast, as in the above embodiments, the target gNB may include a second initial DL BWP configuration in the downlinkConfigCommon information element for the second type of UE. The target gNB can recognize that the UE to be handed over is a second type of UE by including, in the HANDOVER REQUEST message sent by the source gNB, the fact that explicitly or implicitly indicates that the UE is of the second type, or by the UE capability information included in the message.

[0176] As a supplement or alternative to the second initial BWP configuration in the above embodiments, a RAN node (e.g., gNB 1) may configure a second channel bandwidth different from the first channel bandwidth set for the first type of UE for the second type of UE. The second channel bandwidth may be narrower than or equal to the first channel bandwidth. The notification of the second channel bandwidth may be based on reference information different from the reference information used for the notification of the first channel bandwidth. The reference information may indicate the mapping between frequency bands, subcarrier spacing (SCS), and channel bandwidths. More specifically, the channel bandwidth may be represented by a list of DL (or UL) channel bandwidths for the corresponding subcarrier spacing (SCS) (e.g., downlinkChannelBW-PerSCS-List (or uplinkChannelBW-PerSCS-List)). This list may be a list of DL (or UL) channel bandwidth information (SCS-SpecificCarrier) for the corresponding subcarrier spacing (SCS). The channel bandwidth information may include subcarrier spacing (SCS), carrier bandwidth, and carrier offset (offsetToCarrier). The carrier bandwidth may be information in units of a predetermined physical resource (e.g., physical resource block (PRB)). The carrier offset may be an offset value from a predetermined frequency reference point (e.g., point A). The second channel bandwidth may be configured (i.e., sent) to the second type of UE, for example, via an RRC setup message during the RRC (connection) setup procedure or via an RRC reconfiguration message after this procedure. More specifically, the second channel bandwidth may be included as new information (e.g., a field, a parameter) in the ServingCellConfig information element (IE).

[0177] The following configuration may be adopted to enable gNB 1 to know the applicable or expected use cases of UE 2 (e.g., a reduced-capability NR device). In some implementations, gNB 1 may broadcast information indicating the supported use cases in the cell via system information (e.g., SIB1 or other SI). In this case, if the cell supports the applicable or expected use cases of UE 2, then UE 2 may access the cell. In other implementations, UE 2 may notify the applicable or expected use cases to gNB 1 via an initial RRC message (Msg3) (e.g., via an RRC setup request message) after initiating random access. Alternatively, UE 2 may notify the applicable or expected use cases to gNB 1 via an RRC setup complete message (Msg5). In other implementations, the core network (e.g., the AMF of 5GC) may notify the applicable or expected use cases of UE 2 to gNB 1.

[0178] The above embodiments are merely examples of the application of the technical ideas obtained by the inventors of the present application. That is to say, these technical ideas are not limited to the above embodiments and can be variously modified.

[0179] For example, all or some of the embodiments disclosed above can be described as, but are not limited to, the following supplementary descriptions.

[0180] (Supplementary Description 1)

[0181] A radio access network node, i.e., a RAN node, includes:

[0182] At least one memory; and

[0183] At least one processor, which is coupled to the at least one memory and is configured to:

[0184] Broadcast a first initial bandwidth part configuration, i.e., a first initial BWP configuration, via system information; and

[0185] Broadcast a second initial BWP configuration via the system information or send the second initial BWP configuration via radio terminal dedicated signaling,

[0186] wherein the first initial BWP configuration includes cell-specific common parameters of a first initial BWP of the cell,

[0187] wherein the second initial BWP configuration includes cell-specific common parameters of a second initial BWP of the cell,

[0188] wherein the first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the cell,

[0189] wherein the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the cell, and

[0190] wherein the bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0191] (Supplementary Description 2)

[0192] The RAN node according to Supplementary Description 1, wherein

[0193] the cell-specific common parameters of the first initial BWP include parameters indicating the frequency domain position and bandwidth of the first initial BWP, and

[0194] the cell-specific common parameters of the second initial BWP include parameters indicating the frequency domain position and bandwidth of the second initial BWP.

[0195] (Supplementary Description 3)

[0196] The RAN node according to Supplementary Note 1 or 2, wherein

[0197] The cell-specific common parameters of the first initial BWP include physical downlink control channel parameters, i.e., PDCCH parameters, for configuring the common search space in the first initial BWP. This common search space in the first initial BWP is used to transmit downlink control information formats, i.e., DCI formats, indicating resources for broadcasting system information messages, and

[0198] The cell-specific common parameters of the second initial BWP include PDCCH parameters for configuring the common search space in the second initial BWP. This common search space in the second initial BWP is used to transmit DCI formats indicating resources for broadcasting the system information messages.

[0199] (Supplementary Note 4)

[0200] The RAN node according to any one of Supplementary Notes 1 to 3, wherein

[0201] The cell-specific common parameters of the first initial BWP include at least random access parameters used by the first type of radio terminal for contention-based random access in the first initial BWP, and

[0202] The cell-specific common parameters of the second initial BWP include random access parameters used by the second type of radio terminal for contention-based random access in the second initial BWP.

[0203] (Supplementary Note 5)

[0204] The RAN node according to any one of Supplementary Notes 1 to 4, wherein,

[0205] The first initial BWP is used for at least the first type of radio terminal to perform initial access to the cell, and

[0206] The second initial BWP is used for the second type of radio terminal to perform initial access to the cell.

[0207] (Supplementary Note 6)

[0208] The RAN node according to any one of Supplementary Notes 1 to 5, wherein,

[0209] The first initial BWP is a cell-specific BWP commonly used by at least the first type of radio terminal, and

[0210] The second initial BWP is a cell-specific BWP commonly used by the second type of radio terminal.

[0211] (Supplementary Note 7)

[0212] The RAN node according to any one of Supplementary Notes 1 to 6, wherein,

[0213] when the radio terminal of the first type is in the RRC_IDLE state or the RRC_INACTIVE state, the first initial BWP configuration is used, where RRC is Radio Resource Control, and

[0214] when the radio terminal of the second type is in the RRC_IDLE state or the RRC_INACTIVE state, the second initial BWP configuration is used.

[0215] (Supplementary Note 8)

[0216] The RAN node according to any one of Supplementary Notes 1 to 7, wherein,

[0217] the first initial BWP includes a first initial downlink BWP, i.e., the first initial DL BWP, and a first initial uplink BWP, i.e., the first initial UL BWP, and

[0218] the second initial BWP includes a second initial downlink BWP, i.e., the second initial DL BWP, and a second initial uplink BWP, i.e., the second initial UL BWP.

[0219] (Supplementary Note 9)

[0220] The RAN node according to any one of Supplementary Notes 1 to 8, wherein the at least one processor is configured to broadcast the second initial BWP configuration and the first initial BWP configuration together via the system information.

[0221] (Supplementary Note 10)

[0222] The RAN node according to any one of Supplementary Notes 1 to 8, wherein the at least one processor is configured to send the second initial BWP configuration to the radio terminal of the second type via a Radio Resource Control setup message, i.e., an RRC setup message, during a contention-based random access procedure.

[0223] (Supplementary Note 11)

[0224] The RAN node according to Supplementary Note 10, wherein,

[0225] the RAN node includes a Central Unit, i.e., CU, and a Distributed Unit, i.e., DU, the CU is configured to provide at least Radio Resource Control function, i.e., RRC function, and the DU is configured to provide at least Media Access Control function, i.e., MAC function,

[0226] The DU is configured to send a first control message including an indication of limited capabilities to the CU in response to detecting access from a radio terminal of the second type, and

[0227] The CU is configured to generate the RRC setup message including the second initial BWP configuration in response to receiving the indication, and send a second control message including the RRC setup message to the DU.

[0228] (Supplementary Note 12)

[0229] The RAN node according to Supplementary Note 11, wherein,

[0230] The DU is configured to include the second initial BWP configuration in the first control message, and

[0231] The CU is configured to include the second initial BWP configuration taken from the first control message in the RRC setup message.

[0232] (Supplementary Note 13)

[0233] The RAN node according to any one of Supplementary Notes 1 to 8, wherein the at least one processor is configured to: after the RRC setup of the radio terminal of the second type is completed, send the second initial BWP configuration via an RRC reconfiguration message.

[0234] (Supplementary Note 14)

[0235] The RAN node according to Supplementary Note 13, wherein the at least one processor is configured to receive capability information of a radio terminal from a core network, and include the second initial BWP configuration in the RRC reconfiguration message when the capability information indicates limited capabilities.

[0236] (Supplementary Note 15)

[0237] The RAN node according to any one of Supplementary Notes 10 to 14, wherein,

[0238] The at least one processor is configured to broadcast radio access network area information, i.e., RAN area information, via the system information, and

[0239] The radio terminal of the second type uses the RAN area information to determine whether to continue using the second initial BWP configuration when the radio terminal of the second type is in the RRC_IDLE state or the RRC_INACTIVE state after receiving the second initial BWP configuration.

[0240] (Supplementary Explanation 16)

[0241] The RAN node according to any one of Supplementary Explanations 1 to 15, wherein the second type of radio terminal supports a bandwidth narrower than the bandwidth supported by the first type of radio terminal.

[0242] (Supplementary Explanation 17)

[0243] A radio terminal, comprising:

[0244] At least one memory; and

[0245] At least one processor, coupled to the at least one memory and configured to:

[0246] Receive system information including a first initial bandwidth part configuration, i.e., a first initial BWP configuration;

[0247] Receive a second initial BWP configuration via the system information or via radio terminal specific signaling; and

[0248] Use the second initial BWP configuration,

[0249] wherein the first initial BWP configuration includes cell-specific common parameters of the first initial BWP of the serving cell of the radio terminal,

[0250] wherein the second initial BWP configuration includes cell-specific common parameters of the second initial BWP of the serving cell,

[0251] wherein the first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the serving cell,

[0252] wherein the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the serving cell, and

[0253] wherein the bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0254] (Supplementary Explanation 18)

[0255] The radio terminal according to Supplementary Explanation 17, wherein,

[0256] The cell-specific common parameters of the first initial BWP include parameters indicating the frequency domain position and bandwidth of the first initial BWP, and

[0257] The cell-specific common parameters of the second initial BWP include parameters indicating the frequency-domain position and bandwidth of the second initial BWP.

[0258] (Supplementary Note 19)

[0259] The radio terminal according to Supplementary Note 17 or 18, wherein

[0260] The cell-specific common parameters of the first initial BWP include physical downlink control channel parameters, i.e., PDCCH parameters, for configuring the common search space in the first initial BWP. The common search space in the first initial BWP is used to transmit downlink control information formats, i.e., DCI formats, indicating resources for broadcasting system information messages, and

[0261] The cell-specific common parameters of the second initial BWP include PDCCH parameters for configuring the common search space in the second initial BWP. The common search space of the second initial BWP is used to transmit DCI formats indicating resources for broadcasting the system information message.

[0262] (Supplementary Note 20)

[0263] The radio terminal according to any one of Supplementary Notes 17 to 19, wherein

[0264] The cell-specific common parameters of the first initial BWP include at least random access parameters used by the first type of radio terminal for contention-based random access in the first initial BWP, and

[0265] The cell-specific common parameters of the second initial BWP include random access parameters used by the second type of radio terminal for contention-based random access in the second initial BWP.

[0266] (Supplementary Note 21)

[0267] The radio terminal according to any one of Supplementary Notes 17 to 20, wherein

[0268] The first initial BWP is used for at least the first type of radio terminal to perform initial access to the serving cell, and

[0269] The second initial BWP is used for the second type of radio terminal to perform initial access to the serving cell.

[0270] (Supplementary Note 22)

[0271] The radio terminal according to any one of Supplementary Notes 17 to 21, wherein

[0272] The first initial BWP is a cell-specific BWP that is shared by at least the first type of radio terminal, and

[0273] The second initial BWP is a cell-specific BWP that is shared by the second type of radio terminal.

[0274] (Supplementary Note 23)

[0275] The radio terminal according to any one of Supplementary Notes 17 to 22, wherein

[0276] When the first type of radio terminal is in the RRC_IDLE state or the RRC_INACTIVE state, the first initial BWP configuration is used, where RRC is Radio Resource Control, and

[0277] When the second type of radio terminal is in the RRC_IDLE state or the RRC_INACTIVE state, the second initial BWP configuration is used.

[0278] (Supplementary Note 24)

[0279] The radio terminal according to any one of Supplementary Notes 17 to 23, wherein

[0280] The first initial BWP includes a first initial downlink BWP, i.e., the first initial DL BWP, and a first initial uplink BWP, i.e., the first initial UL BWP, and

[0281] The second initial BWP includes a second initial downlink BWP, i.e., the second initial DL BWP, and a second initial uplink BWP, i.e., the second initial UL BWP.

[0282] (Supplementary Note 25)

[0283] The radio terminal according to any one of Supplementary Notes 17 to 24, wherein the at least one processor is configured to receive the second initial BWP configuration and the first initial BWP configuration together via the system information.

[0284] (Supplementary Note 26)

[0285] The radio terminal according to any one of Supplementary Notes 17 to 24, wherein the at least one processor is configured to receive the second initial BWP configuration via a Radio Resource Control setup message, i.e., an RRC setup message, during a contention-based random access procedure.

[0286] (Supplementary Note 27)

[0287] A radio terminal according to any one of Supplementary Notes 17 to 24, wherein the at least one processor is configured to receive the second initial BWP configuration via an RRC reconfiguration message after the RRC setup is completed.

[0288] (Supplementary Note 28)

[0289] A radio terminal according to Supplementary Note 26 or 27, wherein the at least one processor is configured to:

[0290] receive radio access network area information, i.e., RAN area information, via the system information; and

[0291] use the RAN area information to determine whether to continue using the second initial BWP configuration when the radio terminal is in the RRC_IDLE state or the RRC_INACTIVE state after receiving the second initial BWP configuration.

[0292] (Supplementary Note 29)

[0293] A radio terminal according to any one of Supplementary Notes 17 to 28, wherein the at least one processor is configured to: in response to receiving an RRC setup message for establishing a new RRC connection from the network although an RRC connection recovery procedure or an RRC connection re - establishment procedure has been initiated, send an RRC setup complete message including an indication of limited capabilities to the network.

[0294] (Supplementary Note 30)

[0295] A radio terminal according to any one of Supplementary Notes 17 to 29, wherein the second type of radio terminal supports a bandwidth narrower than the bandwidth supported by the first type of radio terminal.

[0296] (Supplementary Note 31)

[0297] A method performed by a radio access network node, i.e., a RAN node, the method comprising:

[0298] broadcasting a first initial bandwidth part configuration, i.e., a first initial BWP configuration, via system information; and

[0299] broadcasting the second initial BWP configuration via the system information or sending the second initial BWP configuration via radio terminal - specific signaling,

[0300] wherein the first initial BWP configuration includes cell - specific common parameters of a first initial BWP of a cell,

[0301] wherein the second initial BWP configuration includes cell - specific common parameters of a second initial BWP of the cell,

[0302] Among them, the first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the cell.

[0303] Among them, the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the cell, and

[0304] Among them, the bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0305] (Supplementary Note 32)

[0306] A method performed by a radio terminal, the method comprising:

[0307] Receiving system information including a first initial bandwidth part configuration, i.e., a first initial BWP configuration;

[0308] Receiving a second initial BWP configuration via the system information or via radio terminal-specific signaling; and

[0309] Using the received second initial BWP configuration,

[0310] Among them, the first initial BWP configuration includes cell-specific common parameters of the first initial BWP of the serving cell of the radio terminal,

[0311] Among them, the second initial BWP configuration includes cell-specific common parameters of the second initial BWP of the serving cell,

[0312] Among them, the first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the serving cell,

[0313] Among them, the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the serving cell, and

[0314] Among them, the bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0315] (Supplementary Note 33)

[0316] A non-transitory computer-readable medium storing a program, the program causing a computer to perform a method for a radio access network node, i.e., a RAN node, the method comprising:

[0317] Broadcast the first initial bandwidth part configuration, i.e., the first initial BWP configuration, via system information; and

[0318] Broadcast the second initial BWP configuration via the system information or send the second initial BWP configuration via radio terminal dedicated signaling,

[0319] wherein, the first initial BWP configuration includes cell-specific common parameters of the first initial BWP of the cell,

[0320] wherein, the second initial BWP configuration includes cell-specific common parameters of the second initial BWP of the cell,

[0321] wherein, the first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the cell,

[0322] wherein, the second initial BWP is not used by the first type of radio terminal, but is used by a second type of radio terminal having limited capabilities compared to the first type of radio terminal and performing contention-based random access in the cell, and

[0323] wherein, the bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0324] (Supplementary Note 34)

[0325] A non-transitory computer-readable medium storing a program, the program causing a computer to perform a method for a radio terminal, the method including:

[0326] Receiving system information including the first initial bandwidth part configuration, i.e., the first initial BWP configuration;

[0327] Receiving the second initial BWP configuration via the system information or via radio terminal dedicated signaling; and

[0328] Using the received second initial BWP configuration,

[0329] wherein, the first initial BWP configuration includes cell-specific common parameters of the first initial BWP of the serving cell of the radio terminal,

[0330] wherein, the second initial BWP configuration includes cell-specific common parameters of the second initial BWP of the serving cell,

[0331] wherein, the first initial BWP is used by at least a first type of radio terminal performing contention-based random access in the serving cell,

[0332] Among them, the second initial BWP is not used by the radio terminals of the first type, but by the radio terminals of the second type that have limited capabilities compared to the radio terminals of the first type and perform contention-based random access in the serving cell, and

[0333] Among them, the bandwidth of the second initial BWP is equal to or narrower than the bandwidth of the first initial BWP.

[0334] This application is based on and claims the priority of Japanese Patent Application No. 2020-022376 filed on February 13, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0335] List of Reference Numerals

[0336] 1 gNB

[0337] 2 UE

[0338] 11 Central Unit (CU)

[0339] 12 Distributed Unit (DU)

[0340] 1504 Processor

[0341] 1505 Memory

[0342] 1506 Module

[0343] 1603 Baseband Processor

[0344] 1604 Application Processor

[0345] 1606 Memory

[0346] 1607 Module

Claims

1. A method for a user equipment, i.e., UE, the method comprising: Receiving System Information Block type 1, i.e., SIB1, the SIB1 including an initial Bandwidth Part configuration, i.e., initial BWP configuration, for a first UE and an initial BWP configuration for a reduced-capability terminal; Performing a random access procedure based on the initial BWP configuration for the reduced-capability terminal, and Sending a specific logical channel ID, i.e., specific LCID, associated with the reduced-capability terminal to a base station in a third message during the random access procedure.

2. The method according to claim 1, wherein, The initial BWP configuration for the reduced-capability terminal is included in the ServingCellConfigCommonSIB information element included in the SIB1.

3. The method according to claim 1, wherein, The initial BWP configuration for the reduced-capability terminal includes an initial downlink BWP, i.e., initial DL BWP, and an initial uplink BWP, i.e., initial UL BWP.

4. The method according to claim 1, wherein The initial BWP configuration for the reduced-capability terminal includes parameters indicating the frequency domain position and bandwidth of the initial uplink BWP, i.e., initial UL BWP, for the reduced-capability terminal.

5. The method according to claim 4, wherein, The parameters indicating the frequency domain position and bandwidth are included in the LocationAndBandwidth field within the genericParameters field of the initial BWP field for the reduced-capability terminal.

6. The method according to claim 1, wherein Performing the random access procedure includes sending a random access preamble based on the initial BWP configuration for the reduced-capability terminal.

7. A user equipment, i.e., UE, comprising: A memory; And At least one processor coupled to the memory and configured to: Receive System Information Block type 1, i.e., SIB1, the SIB1 including an initial Bandwidth Part configuration, i.e., initial BWP configuration, for a first UE and an initial BWP configuration for a reduced-capability terminal; Perform a random access procedure based on the initial BWP configuration for the reduced-capability terminal, and send a specific logical channel ID, i.e., specific LCID, associated with the reduced-capability terminal to a base station in a third message during the random access procedure.

8. The UE according to claim 7, wherein, The initial BWP configuration for the reduced-capability terminal is included in the ServingCellConfigCommonSIB information element included in the SIB1.

9. The UE according to claim 7, wherein, The initial BWP configuration for the reduced-capability terminal includes an initial downlink BWP, i.e., initial DL BWP, and an initial uplink BWP, i.e., initial UL BWP.

10. The UE according to claim 7, wherein, The initial BWP configuration for the reduced-capability terminal includes parameters indicating the frequency domain position and bandwidth of the initial uplink BWP, i.e., initial UL BWP, for the reduced-capability terminal.

11. The UE according to claim 10, wherein, The parameters indicating the frequency domain position and bandwidth are included in the LocationAndBandwidth field within the genericParameters field of the initial BWP field for the reduced-capability terminal.

12. The UE according to claim 7, wherein, Performing the random access procedure includes sending a random access preamble based on the initial BWP configuration for the reduced-capability terminal.

13. A method for a base station, the method comprising: Transmitting System Information Block type 1, i.e., SIB1, where the SIB1 includes an initial Bandwidth Part configuration, i.e., initial BWP configuration, for a first User Equipment, i.e., first UE, and an initial BWP configuration for a reduced-capability terminal; Receiving a message regarding a random access procedure based on the SIB1, and Receiving a specific Logical Channel ID, i.e., specific LCID, associated with the reduced-capability terminal in a third message during the random access procedure.

14. The method according to claim 13, wherein, The message regarding the random access procedure is based on the initial BWP configuration for the reduced-capability terminal included in the SIB1.

15. The method according to claim 13, wherein, The base station is a Distributed Unit, i.e., DU, and The method further comprises: Receiving from the UE a specific Logical Channel ID, i.e., specific LCID, associated with the reduced-capability terminal; and Sending an INITIAL UL RRC MESSAGE TRANSFER message to a Central Unit, i.e., CU, connected via an F1 interface, the message including an indication that the UE is a reduced-capability terminal.

16. The method according to claim 13, wherein, The base station is a Distributed Unit, i.e., DU, and The method further comprises sending a SETUP REQUEST message to a Central Unit, i.e., CU, the message including the initial BWP configuration for the reduced-capability terminal.

17. The method according to claim 13, wherein, The base station is a Distributed Unit, i.e., DU, and The method further comprises sending a gNB-DU CONFIGURATION UPDATE message to a Central Unit, i.e., CU, the message including the initial BWP configuration for the reduced-capability terminal.

18. The method according to claim 13, wherein The initial BWP configuration for the reduced-capability terminal is included in the ServingCellConfigCommonSIB information element included in the SIB1.

19. The method according to claim 13, wherein The initial BWP configuration for the reduced-capability terminal includes an initial Downlink BWP, i.e., initial DL BWP, and an initial Uplink BWP, i.e., initial UL BWP.

20. The method according to claim 13, wherein The initial BWP configuration for the reduced-capability terminal includes parameters indicating the frequency domain position and bandwidth of the initial Uplink BWP, i.e., initial UL BWP, for the reduced-capability terminal.

21. The method according to claim 20, wherein, The parameters indicating the frequency domain position and bandwidth are included in the LocationAndBandwidth field within the genericParameters field of the initial BWP field for the reduced-capability terminal.

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