Communication device and communication method for multi-physical random access channel transmission

Abstract

This disclosure provides a communication device and a communication method for calculating random access radio network temporary identifiers (RA-RNTIs) for handling collisions of random access channel opportunities (ROs) in multi-physical random access channel (multi-PRACH) transmissions. The communication device includes a circuit that, in operation, determines one or more random access radio network temporary identifiers (RA-RNTIs) based on a first group of resources and / or a second group of resources of a random access channel opportunity (RO) group; a transmitting unit that, in operation, transmits a preamble in at least one of the first group of resources; and a receiving unit that, in operation, receives downlink control information (DCI) having cyclic redundancy checks (CRCs) scrambled by one or more RA-RNTIs in response to the preamble transmission.

Description

[Technical Field]

[0001] This disclosure relates to communication devices and communication methods, and more particularly to communication devices and communication methods for multi-physical random access channel (multi-PRACH) transmission. [Background technology]

[0002] In the relevant 3GPP® technical specifications (TS) releases 15, 16, and 17, e.g., 3GPP TS 38.321 version 17.3.0 release 17, single physical random access channel (single-PRACH) transmission may be used. User equipment (UE) may, in a single PRACH transmission, transmit a preamble (e.g., via Msg1) to a base station (e.g., gNB) in one random access channel (RACH) occasion (RO) to obtain uplink synchronization. Each preamble transmission is associated with a random access radio network temporary identifier (RA-RNTI) used to determine random access response (RAR) data (i.e., Msg2) during the random access procedure. In particular, this RO can be used to calculate the RA-RNTI (see Section 5.1.3). The calculation of RA-RNTI is recognized by both the UE and the gNB. The gNB then sends RAR(Msg2) to the UE as a response to the preamble transmission sent by the UE. Within the RAR window, the UE attempts to detect the DCI, which has the CRC scrambled by the calculated RA-RNTI mentioned above. The length of the RAR window can be set by the higher-layer parameter ra-ResponseWindow. Once the UE successfully decodes the DCI, it decodes the PDSCH carrying the RAR. Furthermore, PRACH has been found to be a bottleneck channel in terms of coverage performance in new radio (NR). Therefore, in Release 18, the Physical Layer Working Group (also known as 3GPP RAN1) of the 3rd Generation Partnership Project (3GPP) is discussing supporting multi-PRACH transmission to improve the coverage performance of PRACH.Specifically, a UE may be configured to send multiple PRACH transmissions by using RO groups for a certain number of PRACH transmissions. An RO group may include either shared ROs or individual ROs. That is, an RO group may not include both shared ROs and individual ROs. A shared RO may refer to an RO that is shared by both single and multi-PRACH transmissions. An individual RO may mean that the RO for a single PRACH transmission is separate from the RO for a multi-PRACH transmission.

[0003] In both single-PRACH and multi-PRACH transmissions, ROs can now be dropped due to RO collision events. For example, ROs and other channel or signal resources on a downlink or uplink may be configured separately in different time-domain patterns, which can cause ROs to collide with other channels or signals. In such cases, one or more ROs within an RO group may be dropped due to an RO collision event, and the dropped ROs cannot be used for actual PRACH transmissions for multi-PRACH transmissions. For half-duplex (HD) UEs in paired bands, the gNB may not be aware that a certain number of ROs have been dropped due to the HD-UE implementation, and the number of dropped ROs may differ between HD-UEs. In other cases, the UE may be able to determine several valid ROs for actual PRACH transmissions, but one of the actual PRACH transmissions may not reach the gNB due to channel fading. From the gNB's perspective, a failed PRACH transmission at a corresponding RO may be considered an invalid or dropped RO. For the reasons stated above, discrepancies may occur in the calculation of RA-RNTI between the UE and gNB, and the UE and gNB may calculate RA-RNTI candidates based on two different ROs. This mismatch in RA-RNTI calculation between the UE and gNB can lead to RAR decoding failures at the UE, and consequently, other problems such as increased power consumption for retransmission at the UE.

[0004] Therefore, there is a need to provide a communication device and method for calculating RA-RNTI that solves the above-mentioned problems in multi-PRACH transmission. [Overview of the project]

[0005] Non-limiting and exemplary embodiments contribute to providing a communication device and method for RA-RNTI calculation to handle RO collisions in multi-PRACH transmissions.

[0006] According to a first embodiment of the present disclosure, a communication device is provided which, when in operation, determines one or more random access radio network temporary identifiers (RA-RNTIs) based on a first or second group of random access channel opportunity (RO) groups; a transmitting unit which, when in operation, transmits a preamble in at least one of the first group of resources; and a receiving unit which, when in operation, receives downlink control information (DCI) including a cyclic redundancy check (CRC) scrambled by the one or more RA-RNTIs in response to the transmission of the preamble.

[0007] A second embodiment of the present disclosure provides a first communication device which, when in operation, receives a preamble from a second communication device in at least one of a first plurality of resources of a Random Access Channel Occasion (RO) group; a circuit which, when in operation, determines one or more random access radio network temporary identifiers (RA-RNTIs) based on the first plurality of resources and / or the second plurality of resources, and generates Downlink Control Information (DCI) including a cyclic redundancy check (CRC) scrambled by the one or more RA-RNTIs; and a transmission unit which, when in operation, transmits the DCI to the second communication device.

[0008] A third embodiment of the present disclosure provides a communication method which includes determining one or more random access radio network temporary identifiers (RA-RNTIs) based on a first or second group of resources of a random access channel opportunity (RO) group; transmitting a preamble in at least one of the first or second resources; and receiving Downlink Control Information (DCI) in response to the transmission of the preamble, which includes a cyclic redundancy check (CRC) scrambled by the one or more RA-RNTIs.

[0009] It should be noted that general or specific embodiments can be implemented as systems, methods, integrated circuits, computer programs, storage media, or any selective combination thereof.

[0010] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0011] The embodiments described herein are merely examples, but will be better understood and readily apparent to those skilled in the art through the following description and in conjunction with the drawings. [Figure 1] A diagram illustrating an example architecture of a 3GPP NR Radio Access Network (NR-RAN) to which exemplary embodiments of this disclosure apply. [Figure 2] A schematic diagram illustrating the functional partitioning between an NG-RAN and a 5G Core Network (5GC) to which exemplary embodiments of this disclosure apply. [Figure 3] A sequence diagram of a setup / reconfiguration procedure for a radio resource control (RRC) connection to which exemplary embodiments of the present disclosure apply. [Figure 4] A schematic diagram illustrating usage scenarios for high-speed, high-capacity communication (eMBB: enhanced Mobile Broadband), massive machine type communications (mMTC: massive Machine Type Communications), and ultra-reliable and low-latency communications (URLLC: Ultra Reliable and Low Latency Communications) to which exemplary embodiments of this disclosure apply. [Figure 5] A block diagram illustrating an exemplary 5G system architecture for V2X (vehicle to everything) communication in a non-roaming scenario to which exemplary embodiments of the present disclosure apply. [Figure 6]Exemplary diagram of an RO group for four PRACH transmissions where RO is dropped according to the current technical specifications. [Figure 7] Exemplary diagram of RA-RNTI calculation based on invalid RO according to various embodiments of the present disclosure. [Figure 8] Exemplary diagram of RA-RNTI calculation based on multiple ROs according to various embodiments of the present disclosure. [Figure 9] Exemplary diagram of RA-RNTI calculation based on dedicated time and frequency domain resources according to various embodiments of the present disclosure. [Figure 10] Flowchart of a UE according to various embodiments of the present disclosure. [Figure 11] Flowchart of a gNB according to various embodiments of the present disclosure. [Figure 12] Exemplary diagram of a four-step random access (RA) procedure for multi-PRACH transmission according to various embodiments of the present disclosure. [Figure 13] Flowchart showing a communication method according to various embodiments of the present disclosure. [Figure 14] Schematic block diagram of an exemplary communication device with a single antenna according to various embodiments of the present disclosure. [Figure 15] Schematic block diagram of another exemplary communication device with multiple antennas according to various embodiments of the present disclosure

[0012] Those skilled in the art can understand that the elements in the figures are explained simply and clearly and are not necessarily drawn to a certain scale. For example, for better understanding of the present embodiment, the dimensions of some of the elements in the figures, block diagrams, or flowcharts may be exaggerated with respect to other elements.

Modes for Carrying Out the Invention

[0013] Some embodiments of the present disclosure will be described by way of example with reference to the drawings. Similar reference numerals and characters in the drawings refer to similar or equivalent elements.

[0014] In particular, the overall system architecture assumes an NG-RAN (Next Generation - Radio Access Network) with gNBs, which terminate the NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) protocol and the control plane (RRC) protocol for user equipment (UE). The gNBs are interconnected with each other by means of the Xn interface. Also, the gNBs are connected to the NGC (Next Generation Core) by means of the Next Generation (NG) interface, more specifically, to the AMF (Access and Mobility Management Function) (for example, a specific core entity that executes the AMF) by means of the NG-C interface, and also to the UPF (User Plane Function) (for example, a specific core entity that executes the UPF) by means of the NG-U interface. The NG-RAN architecture 100 is shown in FIG. 1 (see, for example, section 4 of 3GPP TS 38.300 v16.3.0).

[0015] The user plane protocol stack in NR (see, for example, Section 4.4.1 of 3GPP TS 38.300) includes the PDCP (Packet Data Convergence Protocol, see Section 6.4 of TS 38.300) sublayer, the RLC (Radio Link Control, see Section 6.3 of TS 38.300) sublayer, and the MAC (Medium Access Control, see Section 6.2 of TS 38.300) sublayer, all of which terminate at the gNB on the network side. In addition, a new access layer (AS) sublayer (SDAP, Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, Section 6.5 of 3GPP TS 38.300). A control plane protocol stack is also defined in NR (see, for example, Section 4.4.2 of TS 38.300). An overview of Layer 2 functionality is described in Section 6 of TS 38.300. The PDCP, RLC, and MAC sublayer functionalities are described in Sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The RRC layer functionality is described in Section 7 of TS 38.300. Furthermore, sidelink communication was introduced in 3GPP TS 38.300 v16.3.0. Sidelink supports direct communication between UEs using sidelink resource allocation mode, physical layer signals / physical layer channels, and physical layer procedures (see, for example, Section 5.7 of TS 38.300).

[0016] For example, the Medium-Access-Control (MAC) layer handles scheduling and scheduling-related functions, including logical channel multiplexing and processing of various numerologies.

[0017] The Physical Layer (PHY) is responsible for, for example, encoding, PHY HARQ processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. The Physical Layer also handles the mapping of transport channels to physical channels. The Physical Layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels on the uplink include the Physical Random Access Channel (PRACH), Physical Uplink Shared Channel (PUSCH), and Physical Uplink Control Channel (PUCCH), as well as the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH), and Physical Broadcast Channel (PBCH) on the downlink. Furthermore, physical sidelink channels include the Physical Sidelink Control Channel (PSCCH), Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Feedback Channel (PSFCH), and Physical Sidelink Broadcast Channel (PSBCH).

[0018] NR use cases / deployment scenarios include high-speed, high-capacity communication (eMBB), ultra-high-reliability, low-latency communication (URLLC), and / or massive simultaneous connection communication (mMTC), and these services have diverse requirements regarding data rate, latency, and coverage. For example, eMBB is expected to support peak data rates of the order of three times that provided by IMT-Advanced (20 Gbps for downlink and 10 Gbps for uplink) and user-perceived data rates. In contrast, URLLC has more stringent requirements, including extremely low latency (user plane latency of 0.5 ms for UL and DL respectively) and high reliability (1-10 ms within 1 ms). -5 ) and are imposed. Finally, in mMTC, a high connectivity density (1,000,000 devices / km in urban environments) is preferred. 2 ), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for low-cost devices may be required.

[0019] Therefore, OFDM numerology suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may not work well for another use case. For example, low-latency services may preferably require shorter symbol lengths (and thus larger subcarrier spacings) and / or fewer symbols per scheduling interval (also known as TTI) than mMTC services. Furthermore, in configuration scenarios with large channel delay spreads, longer CP lengths may be preferred than in scenarios with smaller delay spreads. To maintain a similar level of CP overhead, the subcarrier spacing should be optimized according to the delay spread. NR may support two or more values ​​for subcarrier spacing. Currently, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc., are considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. As with LTE systems, the term "resource element" can be used to represent the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0020] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each numerology and carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on its frequency index in the frequency domain and its symbol position in the time domain (see 3GPP TS 38.211 v16.3.0).

[0021] Schematic diagram 200 in Figure 2 shows the functional division between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. The logical nodes of 5GC are Access and Mobility Management Function (AMF), User Plane Function (UPF), and Session Management Function (SMF).

[0022] In particular, gNB and ng-eNB handle the following key functions: — Radio resource management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, and dynamic allocation (scheduling) of resources to UEs on both uplink and downlink; — Compression, encryption, and integrity protection of the IP header of the data; — Selection of the AMF when the UE attaches if routing to the AMF cannot be determined from the information provided by the UE; — Routing user plane data for UPF; — Routing of control plane information to AMF; — Setting up and disconnecting connections; — Scheduling and sending paging messages; — Scheduling and transmission of system broadcast information (originating from AMF or OAM); — Setting up measurements and reporting for mobility and scheduling; — Transport-level packet marking on the uplink; — Session management; — Support for network slicing; — Mapping for QoS flow management and data radio bearers; — Support for UEs in RRC_INACTIVE state; — Non-Access Stratum (NAS) message delivery function; — Sharing of wireless access networks; ― Dual connectivity; — Close collaboration between NR and E-UTRA

[0023] The Access and Mobility Management Function (AMF) handles the following key functions: — A function to terminate signaling in the Non-Access Stratum (NAS); — Security of NAS signaling; — Access Stratum (AS) security controls; — Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; — Reachability of the UE in idle mode (including control and execution of paging retransmissions); — Management of registered areas; — Support for intra-system and inter-system mobility; — Access authentication; — Access authorization including roaming permission checks; — Mobility management and control (enrollment and policies); — Support for network slicing; — Selection of Session Management Function (SMF)

[0024] Furthermore, the User Plane Function (UPF) handles the following key functions: — Anchor points for intra-RAT mobility / inter-RAT mobility (where applicable); — External PDU (Protocol Data Unit) session points for interconnection with data networks; — Packet routing and forwarding; — Packet inspection and enforcement of policy rules in the user plane; — Reporting traffic usage; — Uplink classifier that supports routing of traffic flow to data networks; — Branching point for supporting multi-homed PDU sessions; ― QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); — Verification of upstream link traffic (mapping to SDF QoS flow); — Downlink packet buffering and downlink data notification triggering function

[0025] Finally, the Session Management Function (SMF) handles the following main functions: — Session management; — Assignment and management of IP addresses for UEs; — UPF selection and control; — A traffic steering configuration feature in User Plane Functions (UPF) for routing traffic to the appropriate destination; — Policy enforcement and QoS for the control unit; — Notification of downlink data

[0026] Sequence diagram 300 in Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entities) during the transition of the UE from RRC_IDLE to RRC_CONNECTED in the NAS portion (see TS 38.300 v16.3.0). The transition steps are as follows:

[0027] 1. The UE requests that a new connection be set up from the RRC_IDLE state. 2 / 2a. The gNB completes the RRC setup procedure. Note: Scenarios in which the gNB rejects the request are described below. 3. In RRCSetupComplete, the first NAS message from the UE, sent via piggyback, is sent to the AMF. 4 / 4a / 5 / 5a. Additional NAS messages may be exchanged between the UE and the AMF. See reference

[22] in TS 23.502 (3GPP TS 23.122: “Non-Access Layer (NAS) Functions Related to Mobile Stations in Idle Mode”). 6. The AMF prepares the UE context data (including PDU session context, security key, UE radio capability, and UE security capability, etc.) and sends it to the gNB. 7 / 7a. gNB activates AS security with UE. 8 / 8a. The gNB performs a reconfiguration to set up SRB2 and DRB. 9. The gNB notifies the AMF that the setup procedure is complete.

[0028] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. Specifically, in this transition, the AMF creates UE context data (including, for example, PDU session context, security keys, UE radio capabilities, UE security capabilities, etc.) and sends it to the gNB via an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security with the UE, which is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding to the gNB with a SecurityModeComplete message. Subsequently, the gNB performs a reconfiguration to establish the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB), which is done by the gNB sending an RRCReconfiguration message to the UE, and the gNB receiving an RRCReconfigurationComplete from the UE in response. For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the establishment procedure is complete by sending an INITIAL CONTEXT SETUP RESPONSE.

[0029] Schematic diagram 400 in Figure 4 illustrates several use cases for 5G NR. The 3rd generation partnership project NR (3GPP NR) considers three use cases envisioned to support a wide variety of services and applications through IMT-2020. Phase 1 technical specifications for high-speed, high-capacity communication (eMBB) have been determined. Current and future work includes further expansion of eMBB support, as well as standardization for ultra-high reliability, low-latency communication (URLLC) and massive simultaneous connection communication (mMTC). Figure 4 shows some examples of IMT usage scenarios envisioned for 2020 and beyond (see, for example, Figure 2 in ITU-R M.2083).

[0030] URLLC use cases have stringent requirements regarding capabilities such as throughput, latency, and availability, and are envisioned as one means of realizing future vertical applications such as wireless control of industrial manufacturing or production processes, telemedicine surgery, power distribution automation in smart grids, and transportation safety. The ultra-high reliability of URLLC is supported by identifying the technology to meet the requirements set by TR 38.913. For NR URLLC in Release 15, key requirements include a target user plane latency of 0.5 ms for UL (uplink) and 0.5 ms for DL ​​(downlink). Typical URLLC requirements for a single packet transmission are a BLER (block error rate) of 1E-5 for a packet size of 32 bytes with a user plane latency of 1 ms.

[0031] From a physical layer perspective, several ways to improve reliability are possible. Current approaches to reliability improvements include defining separate CQI tables for URLLC, a more compact DCI format, and PDCCH iterations. However, as NR becomes more stable and development progresses (regarding key requirements for NR URLLC), the scope for achieving ultra-high reliability may expand. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0032] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable neurology, mini-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, mini-slot-level repetition on data channels, and preemption on downlink. Preemption means that a transmission for which resources have already been allocated is aborted, and those resources are used for another transmission requested later with lower latency / higher priority requirements. Thus, a transmission that has already been permitted is preempted by a later transmission. Preemption applies regardless of the specific service type. For example, a transmission of service type A (URLLC) can be preempted by a transmission of service type B (e.g., eMBB). Technical enhancements related to reliability include a dedicated Channel Quality Indicator (CQI) / Modulation and Coding Scheme (MCS) table for the 1E-5 target BLER.

[0033] The use case for mMTC (Massively Multiple Connections Communication) is characterized by a very large number of connected devices transmitting relatively small amounts of data, which are generally less affected by latency. These devices need to be low-cost and have extremely long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth is one possible solution to achieve power savings from a UE perspective and enable long battery life.

[0034] As described above, the range of reliability in NR is expected to broaden. One important requirement in all cases, especially for URLLC and mMTC, is high or very high reliability. Several mechanisms can be considered to improve reliability from both a radio and network perspective. In general, there are several important areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity related to the frequency domain, time domain, and / or spatial domain. These areas are generally applicable to reliability regardless of the specific communication scenario.

[0035] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include higher reliability (up to 10) depending on the use case. -6 The advantages include higher availability, a maximum packet size of 256 bytes, time synchronization on the order of a few microseconds (values ​​ranging from 1 to several microseconds depending on the frequency range), and low latency on the order of 0.5 to 1 ms (with a target latency of 0.5 ms specifically for the user plane).

[0036] Furthermore, several technical enhancements are possible for NR URLLC from a physical layer perspective. In particular, enhancements related to the PDCCH (Physical Downlink Control Channel) include a compact DCI, PDCCH repeatability, and increased PDCCH monitoring. Enhancements related to the UCI (Uplink Control Information) include improved HARQ (Hybrid Automatic Repeat Request) and enhanced Channel State Information (CSI) feedback. Enhancements to PUSCH related to minislot-level hopping and retransmission / repeat have also been recognized. The term "minislot" refers to a transmission time interval (TTI) containing fewer symbols than a slot (a slot contains 14 symbols).

[0037] The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bitrate (GBR QoS flows) and QoS flows that do not require a guaranteed flow bitrate (non-GBR QoS flows). Therefore, at the NAS level, QoS flows are the finest granularity of QoS differentiation within a PDU session. Within a PDU session, QoS flows are identified by a QoS flow ID (QFI) transmitted in the encapsulation header via the NG-U interface.

[0038] The 5GC establishes one or more PDU sessions for each UE. The NG-RAN establishes at least one Data Radio Bearer (DRB) with each PDU session for each UE, and can then configure additional DRBs for the QoS flow of that PDU session, as described above, for example with reference to Figure 3 (the NG-RAN decides when to configure them). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filtering in the UE and 5GC associates UL and DL packets with QoS flows, and AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0039] Block diagram 500 in Figure 5 shows the non-roaming reference architecture for 5G NR (see Section 4.2.1.1 of TS 23.287 v16.4.0). Application functions (AFs) (e.g., external application servers handling 5G services as illustrated in Figure 4) interact with the 3GPP Core Network for the purpose of providing services. For example, they support application influence on traffic routing, access Network Exposure Functions (NEFs), or interact with policy frameworks for policy control (e.g., QoS control) (see Policy Control Functions (PCFs)). Based on the operator's deployment, application functions (AFs) that are considered trusted by the operator may be allowed to interact directly with the relevant Network Functions. Application functions that are not authorized by the operator to directly access Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0040] Figure 5 further illustrates the functional units of the 5G architecture for V2X communication, namely the Unified Data Management (UDM), Policy Control Function (PCF), Network Exposure Function (NEF), Application Function (AF), Unified Data Repository (UDR), Access and Mobility Management Function (AMF), Session Management Function (SMF), and User Plane Function (UPF) in 5GC, as well as the V2X Application Server (V2AS) and Data Network (DN; e.g., operator-provided services, internet access, or third-party services). All or some of the core network functions and application services may be deployed and run in a cloud computing environment.

[0041] Under the current technical specifications, user equipment (UE) transmits a preamble (e.g., Msg1) to a base station (gNB) via a physical random access channel (PRACH) to achieve uplink (UL) synchronization in a single PRACH transmission scenario. Each preamble transmission (e.g., RACH opportunity (RO)) is associated with an RA-RNTI candidate, which is calculated based on the RO of a single PRACH transmission (e.g., RO 602) according to the following formula in TS 38.321.

[0042] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id Here, s_id is the index of the leading OFDM symbol of the PRACH opportunity (0 ≤ s_id < 14), t_id is the index of the leading slot of the PRACH opportunity in the system frame (0 ≤ t_id < 80), f_id is the index of the PRACH opportunity in the frequency domain (0 ≤ f_id < 8), and ul_carrier_id is the UL carrier used for PRACH preamble transmission (0 for a normal uplink (NUL) carrier, and 1 for a supplementary uplink (SUL) carrier). s_id, t_id, and f_id are referred herein as multiple indices of RO resources (e.g., time and frequency resources). The gNB then sends a RAR (e.g., Msg2) to the UE in response to the preamble transmission sent by the UE. The UE attempts to detect DCIs with cyclic redundancy checks (CRCs) scrambled by the RA-RNTI calculated above within the RAR window 604 (for example, the length of the RAR window can be set by the higher-layer parameter ra-ResponseWindow). If the UE successfully decodes the DCI, it decodes the PDSCH containing the RAR. The calculation of RA-RNTI candidates is recognized by both the UE and the gNB.

[0043] In the case of multi-PRACH transmissions in the technical specification of Rel.18, it has recently been agreed that RO groups are introduced for a certain number of PRACH transmissions. RO groups may contain only shared ROs or only individual ROs, but cannot contain both shared and individual ROs (for example, shared ROs or individual ROs mean that the ROs are either shared with or separated from the use case of a single PRACH transmission). The UE can send multiple PRACH transmissions by using RO groups for a certain number of PRACH transmissions. Only one RAR window is supported for RAR monitoring in a single RACH attempt of a multi-PRACH transmission. The method for calculating RA-RNTI for multi-PRACH transmissions is not definitive, as indicated in the agreements in the technical specification of Rel.18, as follows: For multiple PRACH transmissions with the same transmit (Tx) beam, only one RAR window is supported for RAR monitoring of a single RACH trial, and further study (FFS) is required regarding the start position of the RAR window and the calculation of RA-RNTI. It should be understood that "RO group" may also be called RO grouping, set of ROs, group of ROs, RO bundle, or RO bundling.

[0044] Currently, ROs can collide with other channels or signals because RO resources and other channel or signal resources on the downlink or uplink may be separate configurations with different time-domain patterns (e.g., collision events occurring within the UE and not in the air). For non-paired band UEs, ROs may be dropped due to collisions with SSBs based on the following RO drop rules (e.g., section 8.1 of TS 38.213): (1) The UE is not provided with tdd-UL-DL-ConfigurationCommon, and RO precedes a synchronization signal block (SSB) in the PRACH slot, and at least N of the last SSB received symbols.gap Starts after the symbol (N gap (2) If channelAccessMode="semiStatic" is provided, the RO overlaps with a set of consecutive symbols before the start of the next channel occupancy time that the UE does not transmit [TS 37.213, Section 15], (3) If tdd-UL-DL-ConfigurationCommon is provided to the UE, the RO precedes the SSB in the PRACH slot and is at least N of the last downlink symbols gap After the symbol, and of the last SSB, at least N gapStarting after the symbol, when channelAccessMode = "semiStatic" is provided, the RO overlaps with a set of consecutive symbols before the start of the next channel occupancy time without any transmission. For a half-duplex UE (HD-UE) in a paired band, the RO can be dropped or held due to collision with an SSB or other signal / channel based on the following RO drop rules or the implementation of the HD-UE (TS 38.213, section 17.2). (1) If the HD-UE transmits a PRACH based on the detected DCI format and the presence of an SSB in the set of symbols is indicated to the HD-UE, the HD-UE does not transmit a PUSCH, PUCCH, or PRACH if the transmission overlaps with any symbol in the set of symbols. (2) If the HD-UE transmits a PRACH or MsgA PUSCH triggered by a higher layer in the set of symbols, receives a PDCCH, PDSCH, channel state information reference signal (CSI-RS), or downlink positioning reference signal (PRS), or the presence of an SSB in a symbol including any symbol in the set of symbols is indicated, the HD-UE can choose to transmit a PRACH or MsgA PUSCH or receive a PDSCH, CSI-RS, physical layer (PL) RS, PDCCH, or SSB based on the implementation of the HD-UE. (3) If the HD-UE receives a PDCCH, PDSCH, CSI-RS, or DL PRS based on a higher layer setting or the presence of an SSB is indicated in the set of symbols, and the HD-UE transmits a PRACH or MsgA PUSCH triggered by a higher layer that starts or ends with a symbol more than N RX-TX ·T c or N RX-TX ·T c earlier or later than the last or first symbol in the set of symbols, the HD-UE can choose to transmit a PRACH or MsgA PUSCH or receive a PDSCH, CSI-RS, DL PRS, PDCCH, or SSB based on the implementation of the HD-UE. Note that N RX-TX 、N TX-RX 、and T cThis is specified in TS 38.213. The above-mentioned (collision-induced) RO drop applies to both single and multi-PRACH transmissions. In the case of multi-PRACH transmissions, one or more ROs within an RO group may be dropped because additional collisions can occur between ROs within an RO group (e.g., individual ROs) and other functions (e.g., 2-step RACH). This means that the number of valid ROs for an actual PRACH transmission may be less than a certain number of multiple PRACH transmissions.

[0045] Currently, RA-RNTI calculation, up to Rel.18, is based on the use of one RO in a single PRACH transmission. For multi-PRACH transmissions, the conventional approach may be extended to reuse based on the use of one RO within an RO group. A potential problem is a discrepancy in RA-RNTI calculation between the UE and gNB, which could lead to RAR decoding failures on the UE side. As a result, power consumption at the UE may increase due to retransmission. The discrepancy can occur for one or more reasons. One possible reason is that the gNB assumes that one of the ROs in an RO group will be used for RA-RNTI calculation, but that RO is dropped by the UE due to an RO collision. Therefore, the UE and gNB may calculate RA-RNTI candidates based on two different ROs. For example, referring to illustration 600 in Figure 6, a UE is provided with RO group 602 having four specific PRACH transmissions (associated RO604, 606, 608, and 610), where RO604 could be used to calculate the UE's RA-RNTI in the RAR window 612. However, RO604 is dropped due to an RO collision, and therefore only RO606, 608, and 610 are used for the three actual PRACH transmissions. Thus, a gNB receiving the three actual PRACH transmissions may calculate the RA-RNTI based on one of RO606, 608, and 610 instead of RO604. In another example, for a paired-band HD-UE, the gNB may not be aware of the number of active ROs used for the actual PRACH transmissions due to implementation issues with the HD-UE (the number of active ROs may differ between HD-UEs). Therefore, the gNB may calculate the RA-RNTI based on different ROs. Another possible reason for the discrepancy is that the UE can determine several valid ROs for an actual PRACH transmission, but one of the actual PRACH transmissions may not reach the gNB due to channel fading. The gNB may then assume that the failed PRACH transmission at the corresponding RO is either an invalid RO or a dropped RO.Therefore, UEs and gNBs may calculate RA-RNTI candidates based on two different ROs. Consequently, to resolve the above issue, it is necessary to identify a more robust approach to calculating RA-RNTI for all types of UEs, both paired-band and unpaired-band.

[0046] In this disclosure, an RO group may include at least one active RO and zero or one or more invalid ROs for a given N PRACH transmissions (for example, an RO group may include at least one active RO, or an RO group may include at least one active RO and at least one invalid RO). RA-RNTI may be calculated based on one of the following three solutions, regardless of whether there is at least one active RO and zero or one or more invalid ROs, in order to align the calculation of RA-RNTI between the UE and the gNB: (Solution 1) Calculate RA-RNTI based on one RO in the RO group, for example, whether it is an active or invalid RO. (Solution 2) Calculate RA-RNTI based on multiple ROs in the RO group, from at least one active RO and zero or one or more invalid ROs. (Solution 3) Calculate RA-RNTI based on a dedicated resource associated with the RO group. Active ROs are used for actual PRACH transmissions, and invalid ROs are not used for actual PRACH transmissions. Active ROs are identified after reviewing the RO drop rules (or verification rules) for determining active ROs. Dedicated time and frequency domain resources are used for the purpose of RA-RNTI calculation and are not used for a specific N PRACH transmission. Advantageously, even if a certain number of ROs in an RO group are dropped, or if one of the actual PRACH transmissions in an active RO fails to reach the gNB, the corresponding RAR for a multi-PRACH transmission can still be successfully decoded. It will be understood that N can be set to 2, 4, 8, 16, or 32 to support 2, 4, 8, 16, or 32 PRACH transmissions, respectively, and does not exclude the number of other values ​​for N. N PRACH transmissions may also be called multiple PRACH transmissions, multi-PRACH transmissions, or one PRACH attempt of a multi-PRACH transmission.

[0047] Furthermore, signaling for RA-RNTI calculation (e.g., RA-RNTI calculation based on any of solutions 1-3) may be performed based on the following methods: (1) Method 1 is an explicit notification that can be used based on one or a combination of RRC signaling, MAC CE, and DCI (e.g., a notification in SIB1 / MIB is used); (2) Method 2 may be specified in the technical specification which of solutions 1-3 should be used; (3) Method 3 is an implicit notification that, for example, one of solutions 1-3 may be assigned to each type of UE. For example, solution 1 may be assigned to RedCap (reduced capacity) UEs, solution 2 to be assigned to non-RedCap UEs, and other similar implementations, determinations, or assignments may be made. In this case, early identification of the type of UE in the gNB during initial access allows the gNB to determine which solution the UE will use in calculating RA-RNTI. Therefore, the UE may be configured to define notifications for one or more RA-RNTI decisions via upper-layer signaling, MAC CE signaling, or other DCIs, or one or more RA-RNTI decisions may be pre-configured or specified in the technical specifications.

[0048] In implementing Solution 1, the base station may provide the UE with control information indicating multiple ROs included in an RO group, for example, using higher-layer signaling such as RRC signaling. Multiple ROs may be used for multi-PRACH transmission. The UE receives the control information indicating multiple ROs included in an RO group and may calculate the RA-RNTI based on at least one RO in the RO group according to one of the following options 1 to 3. The UE then transmits a preamble for one or more ROs in the RO group, and the base station receives the preamble and calculates the RA-RNTI based on at least one RO in the RO group. The base station may also transmit Downlink Control Information (DCI) including a cyclic redundancy check (CRC) scrambled by the RA-RNTI, and the UE receives the DCI. The UE attempts to detect the DCI. If the UE successfully decodes the DCI, it decodes the PDSCH carrying the RAR. The calculation of the RA-RNTI is known to both the UE and the gNB.

[0049] In Option 1, the RA-RNTI may be calculated based on the first RO in the RO group (whether it is an active or inactive RO, for example). For example, even if the first RO in the RO group is an inactive RO, the RA-RNTI is calculated based on that inactive RO at the UE and base station. In other words, the time and frequency resource indices of the first RO (e.g., s_id, t_id, f_id, and other similar indices) may be used in the formula for calculating the RA-RNTI. In this case, the preamble is not transmitted at the first RO if the first RO is an inactive RO, and can only be transmitted at some or all of the active ROs in the RO group. Option 1 can keep signaling overhead low. Furthermore, if the first RO is an active RO, Option 1 may be suitable for early termination of multi-PRACH transmissions, as power consumption can be saved because if the UE can receive the RAR after the first PRACH transmission at the first RO, the UE can terminate the remaining PRACH transmissions at the remaining ROs (other than the first RO). In this case, the RAR window for multi-PRACH transmission can be started after the first RO in the RO group.

[0050] In Option 2, RA-RNTI may be calculated based on the nth RO in the RO group (whether it is an active or inactive RO, for example). For example, even if the nth RO in the RO group is an inactive RO, the UE and base station will calculate RA-RNTI based on that inactive RO. In other words, the time resource and frequency resource index of the nth RO (e.g., s_id, t_id, f_id, and other similar indices) may be used in the formula for calculating RA-RNTI. n may be greater than 1 and less than the total number of ROs in the RO group, and may be (pre-configured), for example, in System Information Block Type 1 (SIB1) or Master Information Block (MIB). In this case, the preamble will not be transmitted at the nth RO if the nth RO is an inactive RO, and may only be transmitted at some or all of the active ROs in the RO group. In Option 2, the gNB has more flexibility in configuring which ROs to use in calculating RA-RNTI.

[0051] In Option 3, the RA-RNTI can be calculated based on the last RO in the RO group (whether it is an active or inactive RO, for example). For example, even if the last RO in the RO group is an inactive RO, the RA-RNTI is calculated based on that inactive RO at the UE and base station. In other words, the time and frequency resource indices of the last RO (e.g., s_id, t_id, f_id, and other similar indices) may be used in the formula for calculating the RA-RNTI. In this case, the preamble is not transmitted at the last RO if the last RO is an inactive RO, and can only be transmitted at some or all of the active ROs in the RO group. Option 3 can keep signaling overhead low. Also, Option 3 may be suitable for implementing composite detection of multi-PRACH transmissions and can improve the performance gain of preamble detection at the gNB side. In this case, the RAR window for multi-PRACH transmissions can start after the last RO in the RO group. Also, Option 3 has less impact on current standards compared to Options 1 and 2.

[0052] For example, referring to Figure 700 in Figure 7, suppose that for four specific PRACH transmissions, RO group 702, including RO704, 706, 708, and 710, is provided to the UE. After checking the RO drop rule (or verification rule), RO704 is determined to be invalid, while RO706, 708, and 710 are determined to be valid. Since the RO that forms the basis for calculating the RA-RNTI can be a valid or invalid RO within the RO group after checking the RO drop rule, the RO used to calculate the UE's RA-RNTI in the RAR window 712 could be RO704 using option 1, RO708 using option 2 with n=3, or RO710 using option 3. Advantageously, existing formulas for calculating the RA-RNTI can be reused, minimizing the impact on current standards.

[0053] To implement Solution 2, the base station may provide the UE with control information indicating multiple ROs included in an RO group, for example, using higher-layer signaling such as RRC signaling. Multiple ROs may be used for multi-PRACH transmission. The UE may receive control information indicating multiple ROs included in an RO group, and the RA-RNTI may be calculated at the UE and base station based on one or more ROs from at least one active RO and / or zero or one or more inactive ROs in the RO group. The RA-RNTI may be calculated using the sum of the time-domain resource indices of one or more ROs in the RO group (e.g., M ROs (1 ≤ M ≤ N)) and the sum of the frequency-domain resource indices of one or more ROs. The UE then transmits a preamble for one or more ROs in the RO group, and the base station receives the preamble and calculates the RA-RNTI based on at least one RO in the RO group. Alternatively, the base station may transmit a DCI with a CRC scrambled by the RA-RNTI, and the UE receives the DCI. The UE attempts to detect the DCI. Once the UE successfully decodes the DCI, it decodes the PDSCH that carries the RAR. The calculation of RA-RNTI is known by both the UE and gNB.

[0054] For example, referring to Figure 800 in Figure 8, suppose that for four specific PRACH transmissions, RO group 802, including RO804, 806, 808, and 810, is provided to the UE. After checking the RO drop rule (or verification rule), it is determined that RO804 is invalid, but RO806, 808, and 810 are valid. Since RA-RNTI can be calculated based on one or more ROs from at least one valid RO and / or 0 or one or more invalid ROs within the RO group, one or more of RO804, 806, 808, and 810 may be used in the UE's RA-RNTI calculation in the RAR window 812. In one embodiment, multiple ROs (e.g., all of RO804, 806, 808, and 810) may be used in the RA-RNTI calculation. The calculation of RA-RNTI may be expressed by the following formula: RA-RNTI=1+s_id_sum+14×t_id_sum+14×80×f_id_sum+14×80×8×UL_carrier_id, where,

number

number

number

[0055] To implement Solution 3, the base station may provide the UE with control information indicating multiple ROs included in an RO group, for example, using higher-layer signaling such as RRC signaling. Multiple ROs may be used for multi-PRACH transmission. The UE may receive control information indicating multiple ROs included in an RO group, and the RA-RNTI may be calculated at the UE and base station based on dedicated resources associated with the RO group (dedicated resources for each RO group). Dedicated resources associated with an RO group may be used solely for the purpose of calculating the RA-RNTI; for example, dedicated resources are used to calculate the RA-RNTI of the associated RO group. Dedicated resources may be separate resources compared to the time-domain and frequency-domain resources of at least one active RO and 0 or more inactive ROs within the RO group, and may not be used for PRACH transmission. Dedicated resources may be dedicated time-domain and frequency-domain resources, identification numbers, or allocation indices, or non-zero values. The calculation of the RA-RNTI based on dedicated resources may be expressed by the following formula: RA-RNTI=1+s_id_dedi+14×t_id_dedi+14×80×f_id_dedi+14×80×8×UL_carrier_id, where s_id_dedi, t_id_dedi, and f_id_dedi are indices of the dedicated time and frequency domain resources associated with the RO group. These are not related to the RO index within the RO group, as shown in Solutions 1 and 2. The dedicated resources associated with the RO group can be (pre-configured). For multiple RO groups, the dedicated time and frequency domain resources of each of the multiple RO groups are different from each other.

[0056] For example, referring to Figure 900 in Figure 9, suppose that RO group 902, including RO904, 906, 908, and 910, is provided to the first UE for four specific PRACH transmissions, and RO group 914, including RO916 and 918, is provided to the second UE for two specific PRACH transmissions. Furthermore, dedicated time and frequency domain resources 922 and 924 are associated with RO groups 902 and 914, respectively. Since RA-RNTI may be calculated based on the dedicated resources associated with the RO groups, dedicated time and frequency domain resources 922 may be used to calculate the RA-RNTI of the first UE in RAR window 912, and dedicated time and frequency domain resources 924 may be used to calculate the RA-RNTI of the second UE in RAR window 920. Since the dedicated time and frequency domain resources associated with an RO group can be pre-configured (for example, a table-based notification containing a list of dedicated time and frequency domain resources for all possible RO groups supported in the serving cell (e.g., 64 RO groups based on the number of preambles)), there is the advantage that no additional signaling overhead is incurred for the purpose of RA-RNTI calculation.

[0057] In one embodiment, the RA-RNTI may be calculated based on only one or more active ROs in an RO group (referred to here as Solution 4). For example, a base station may provide the UE with control information indicating multiple ROs included in an RO group using higher-layer signaling such as RRC signaling. Multiple ROs may be used for multi-PRACH transmission. The UE may receive control information indicating multiple ROs included in an RO group, and the RA-RNTI may be calculated by the UE and base station based on only one or more active ROs in the RO, according to one of the following options: Option A is calculated based on the active ROs in the RO group (e.g., similar to Options 1-3 of Solution 1, but with active ROs used for RA-RNTI calculation). Option B is calculated based on multiple active ROs in an RO group (e.g., similar to Solution 2, but with multiple active ROs used for RA-RNTI calculation). Also, different UEs may determine different RA-RNTI candidates because the number of active or inactive ROs differs between UEs.

[0058] In one embodiment, on a case-by-case basis, any of solutions 1-3 or solution 4 may be used in the serving cell. In case 1, if the paired-band HD-UE in the serving cell supports an "arbitrary RO count" scheme to form RO groups for multi-PRACH transmissions (for example, in the "arbitrary RO count" scheme, both active and inactive ROs in an RO group are counted for a predetermined number of multiple PRACH transmissions, an RO is identified as inactive if it is not used for an actual PRACH transmission due to an RO drop event, and active ROs are used for actual PRACH transmissions), any of solutions 1-3 may be used. In case 2, for a serving cell that supports an "active RO only count" scheme to form RO groups for multi-PRACH transmissions (for example, in the "active RO only count" scheme, for a predetermined number of multiple PRACH transmissions, the count is based only on active ROs in the RO group, and active ROs are used for actual PRACH transmissions), solution 4 is used. As an alternative to Case 1, the HD-UE may adjust SSB reception during the random access procedure for multi-PRACH transmission (for example, PRACH transmission at RO takes priority over SSB reception during the random access procedure, and RO is not dropped even if there is a collision with SSB reception (hence it is a valid RO)), thus allowing the use of Solution 4.

[0059] By using either Solution 1-3 or Solution 4, the RA-RNTI can be calculated in common among UEs (including all types of UEs) in a serving cell. Furthermore, one of Solutions 1-3 and Solution 4 may be set based on the type of UE for which the RA-RNTI is calculated in the serving cell; for example, a solution may be assigned to each type of UE (e.g., for RedCap UEs and for non-RedCap UEs).

[0060] In one embodiment, the RO group includes at least active ROs and inactive ROs, and RA-RNTI may be calculated based on at least the inactive RO. In Option 1 of Solution 1, as a modification, if the first RO in the RO group is an inactive RO, RA-RNTI may be calculated based on at least the inactive RO. In Option 2 of Solution 1, as a modification, if the nth RO in the RO group is an inactive RO, RA-RNTI may be calculated based on at least the inactive RO. In Option 3 of Solution 1, as a modification, if the last RO in the RO group is an inactive RO, RA-RNTI may be calculated based on at least the inactive RO. Furthermore, RA-RNTI can be calculated using combinations of parameters from Solutions 1, 2, and 3.

[0061] In one embodiment, one of solutions 1 to 4 is applicable to both scenarios of multi-PRACH transmission: (1) In scenario 1, the multi-PRACH transmission is transmitted by the UE using a single antenna. (2) In scenario 2, the multi-PRACH transmission is transmitted by the UE using multiple antennas. Furthermore, one of solutions 1 to 4 can be applied to both CBRA (contention-based random access) procedures and CFRA (contention-free random access) procedures.

[0062] Figure 10 shows a flowchart 1000 for a UE according to various embodiments of the present disclosure. In step 1002, the UE may be provided with RO groups containing N ROs for a particular N PRACH transmissions. It will be understood that N can be set to 2, 4, 8, 16, or 32, respectively, to support 2, 4, 8, 16, or 32 PRACH transmissions. The number of active ROs for the actual PRACH transmissions in the RO group may be less than or equal to N due to RO collision events. In step 1004, the UE may virtually calculate one RA-RNTI for the RO group based on one of solutions 1-3, regardless of whether the ROs are active or inactive. In step 1006, the UE may use the active ROs to send an actual PRACH transmission (e.g., Msg1 in a 4-step RACH (Random Access Channel) procedure). In step 1008, the UE may receive a DCI having a CRC scrambled by the calculated RA-RNTI in order to receive the RAR of a multi-PRACH transmission, and decode the PDSCH carrying the RAR (e.g., Msg2 transmitted from the gNB in ​​a 4-step RACH procedure).

[0063] Figure 11 shows a flowchart 1100 for a gNB according to various embodiments of the present disclosure. In step 1102, the gNB may provide a group of ROs containing ROs for a particular N PRACH transmissions. In step 1104, the gNB may virtually calculate one RA-RNTI based on one of solutions 1-3, regardless of whether the ROs are active or inactive. The gNB may generate a DCI having a CRC scrambled by the calculated RA-RNTI. The DCI may schedule a PDSCH that carries a RAR, which is a response to an actual PRACH transmission sent by the UE. In step 1106, the gNB may send a DCI scheduling a PDSCH, and then send a PDSCH carrying a RAR to the UE (e.g., Msg2 in a 4-step RACH procedure).

[0064] Figure 12 illustrates a four-step random access (RA) procedure 1200 for multi-PRACH transmission according to various embodiments of the present disclosure. In step 1206, UE 1202 may virtually calculate the RA-RNTI for the RO group based on one of solutions 1-3, regardless of whether the RO is enabled or disabled, and send the random access preamble to gNB 1204 via Msg1. It will be understood that the UE may calculate the RA-RNTI for the RO group before, after, or during the process of sending a multi-PRACH transmission. This depends on either (i) the configuration from gNB to UE for monitoring RAR in the RAR window, or (ii) the implementation issues of the UE. The random access preamble in a multi-PRACH transmission is based on the RO group. In step 1208, gNB1204 may virtually calculate RA-RNTI based on one of solutions 1-3, regardless of whether the RO in the RO group is valid or invalid, and then send the RAR on PDSCH(Msg2) to UE1202 in response to the multi-PRACH transmission. Specifically, gNB may generate a DCI that schedules a PDSCH carrying the RAR having a scrambled CRC by the calculated RA-RNTI, and then send the PDSCH carrying the RAR to UE1202. In step 1210, UE may decode the DCI using the RA-RNTI calculated by UE in order to decode the PDSCH carrying the RAR received from gNB1204. In step 1212, UE may send Message3(Msg3)PUSCH to gNB1204. In step 1214, gNB1204 may send Message4 (Msg4) (e.g., PDCCH / PDSCH) to UE1202.

[0065] Although the above procedure 1200 is shown as a four-step RACH procedure in contention-based random access (CBRA), it will be understood that this disclosure (e.g., solutions 1-3, flowcharts 1000 and 1100) can also be implemented as a two-step RACH procedure or as a four-step RACH procedure in contention-free random access (CFRA).

[0066] Figure 13 shows a flowchart 1300 illustrating a communication method according to various embodiments of the present disclosure. In step 1302, one or more random access radio network temporary identifiers (RA-RNTIs) may be determined based on a first group of resources and / or a second group of resources in a random access channel opportunity (RO) group. In step 1304, a preamble may be transmitted in at least one of the first group of resources. In step 1306, in response to the transmission of the preamble, Downlink Control Information (DCI) having a cyclic redundancy check (CRC) scrambled by one or more RA-RNTIs may be received.

[0067] Figure 14 shows a schematic partial cross-sectional view of a communication device 1400 that can be implemented according to the various embodiments and examples shown in Figures 1 to 13. The communication device 1400 can be implemented as a UE or base station according to various embodiments.

[0068] The various functions and operations of the communication device 1400 are arranged in multiple layers according to a hierarchical model. In this model, lower layers report to higher layers and receive commands from higher layers in accordance with 3GPP technical specifications. For simplicity, the details of the hierarchical model are not described in this disclosure.

[0069] As shown in Figure 14, the communication device 1400 may comprise a circuit 1414, at least one radio transmit (Tx) chain 1402 (also referred to here as the transmitter 1402), at least one radio receive (Rx) chain 1404 (also referred to here as the receiver 1404), and at least one antenna 1412 (for simplification, only one antenna is depicted in Figure 14 for illustrative purposes). The circuit 1414 may include at least one control unit 1406. The control unit 1406 is used to perform tasks designed to be performed by at least one control unit 1406, with the assistance of software and hardware. Tasks include controlling communication with one or more other communication devices in a radio network. The circuit 1414 may further comprise at least one transmit signal generation unit 1408 and at least one receive signal processing unit 1410. At least one control unit 1406 can control, under the control of at least one control unit 1406, at least one transmit signal generation unit 1408 for generating signals (e.g., baseband signals) to be transmitted via at least one radio transmitter 1402 to one or more other communication devices (e.g., base station communication devices), and at least one receive signal processing unit 1410 for processing signals (e.g., baseband signals) received from one or more other communication devices via at least one radio receiver 1404, under the control of at least one control unit 1406. The at least one transmit signal generation unit 1408 and the at least one receive signal processing unit 1410 may be standalone modules of the communication device 1400 that communicate with at least one control unit 1406 for the functions described above, as shown in Figures 1-13. Alternatively, the at least one transmit signal generation unit 1408 and the at least one receive signal processing unit 1410 may be included in at least one control unit 1406. It will be apparent to those skilled in the art that the arrangement of these functional modules is flexible and may vary according to actual needs and / or requirements. Data processing, virtual memory, and other related control devices can be provided on a suitable circuit board and / or within a chipset.In various embodiments, during operation, at least one radio transmitter 1402, at least one radio receiver 1404, and at least one antenna 1412 may be controlled by at least one control unit 1406. It will be understood that the communication device 1400 may include multiple antennas 1512, for example, as shown in the communication device 1500 of Figure 15. The multiple antennas 1512 can be connected to the corresponding Tx chains 1502 and Rx chains 1504 via a switcher or switch point. Alternatively, each of the multiple antennas 1512 may be connected to the corresponding Tx chain or Rx chain.

[0070] The communication device 1400, when in operation, provides the functions necessary for RA-RNTI calculation to handle RO collisions in multi-PRACH transmissions. For example, the communication device 1400 is an UE, and the circuit 1414, when in operation, may determine one or more Random Access Radio Network Temporary Identifiers (RA-RNTIs) based on a first group of resources and / or a second group of resources in a Random Access Channel Opportunity (RO) group. The transmitter 1402, when in operation, may transmit a preamble on at least one of the first group of resources. The receiver 1404, when in operation, may receive downlink control information (DCI) having cyclic redundancy checks (CRCs) scrambled by one or more RA-RNTIs in response to the preamble transmission.

[0071] The first set of resources may be multiple radio resources of multiple ROs within an RO group. The set of ROs may include at least one active RO and at least one inactive RO, and the circuit 1414 may be configured to determine one or more RA-RNTIs based on at least one radio resource of at least one inactive RO in the first set of resources.

[0072] The nth RO of multiple ROs may be either an active or inactive RO, where n is an integer ranging from 1 to the total number of ROs, and circuit 1414 may be configured to determine one or more RA-RNTIs based on at least one radio resource of the nth RO. n may be notified by higher layer signaling, MAC CE signaling, other DCIs, pre-configured, or defined in the technical specification.

[0073] Multiple ROs may all be active ROs, or they may include at least one active RO and at least one inactive RO. Circuit 1414 may be configured to determine one or more RA-RNTIs based on two or more radio resources of only active ROs in the first multiple resources, or based on two or more radio resources of at least one active RO and at least one inactive RO in the first multiple resources.

[0074] The second set of resources may be multiple dedicated resources associated with an RO group, and the circuit 1414 may be configured to determine one or more RA-RNTIs based on the multiple dedicated resources. The multiple dedicated resources may include specific radio resources separate from the radio resources of multiple ROs within the RO group, or include identification numbers, assignment indices, or non-zero values.

[0075] Circuit 1414 may be configured to determine one or more RA-RNTIs based on the serving cell associated with the communication device. Circuit 1414 may be further configured to determine one or more RA-RNTIs based on the type of communication device. Circuit 1414 may be further configured to define notification of the determination of one or more RA-RNTIs via upper layer signaling, MAC CE signaling, other DCIs, or the determination of one or more RA-RNTIs may be pre-configured or specified in the technical specifications.

[0076] Circuit 1414 may be configured to determine one or more RA-RNTIs based on a function of a first plurality of resources and / or a second plurality of resources, the function of which is notified by upper layer signaling, MAC CE signaling, downlink control information (DCI), or specified in the technical specification. Circuit 1414 may be configured to determine one or more RA-RNTIs based on a subset of the first plurality of resources and / or a second plurality of resources, the subset of which is notified by upper layer signaling, MAC CE signaling, downlink control information (DCI), or specified in the technical specification. Circuit 1414 may be further configured to decode a Physical Downlink Shared Channel (PDSCH) carrying a Random Access Response (RAR) based on the determined one or more RA-RNTIs.

[0077] The communication device 1400 may be a first communication device, and the receiving unit 1404 may, during operation, receive a preamble from a second communication device in at least one of a first plurality of resources of a random access channel opportunity (RO) group. The circuit 1414 may, during operation, determine one or more random access radio network temporary identifiers (RA-RNTIs) based on the first plurality of resources and / or a second plurality of resources, and generate downlink control information (DCI) having cyclic redundancy checks (CRCs) scrambled by one or more RA-RNTIs. The transmitting unit 1402 may, during operation, transmit the DCI to the second communication device.

[0078] (Control signal) In this disclosure, the downlink control signal (information) relating to this disclosure may be a signal (information) transmitted via the PDCCH of the physical layer, or it may be a signal (information) transmitted via the MAC Control Element (CE) of the upper layer or RRC. The downlink control signal may be a predefined signal (information).

[0079] The uplink control signal (information) relating to this disclosure may be a signal (information) transmitted via PUCCH at the physical layer, or a signal (information) transmitted via MAC CE at a higher layer or RRC. Furthermore, the uplink control signal may be a predefined signal (information). The uplink control signal may be Uplink Control Information (UCI), first-stage sidelink control information (SCI), or second-stage SCI.

[0080] (base station) In this disclosure, a base station may be, for example, a transmission reception point (TRP), a cluster head, an access point, a remote radio head (RRH), an eNodeB (eNB), a gNodeB (gNB), a base station (BS), a base transceiver station (BTS), a base unit, or a gateway. In side-link communication, a terminal may be used instead of a base station. A base station may be a relay device that relays communication between a higher-level node and a terminal. A base station may be a roadside unit.

[0081] (Uphill rink / Downhill rink / Side rink) This disclosure may apply to uplinks, downlinks, and sidelinks.

[0082] For example, this disclosure may be applied to uplink channels such as PUSCH, PUCCH, and PRACH, downlink channels such as PDSCH, PDCCH, and PBCH, and sidelinks such as PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), and PSBCH (Physical Sidelink Broadcast Channel).

[0083] PDCCH, PDSCH, PUSCH, and PUCCH are examples of downlink control channels, downlink data channels, uplink data channels, and uplink control channels, respectively. PSCCH and PSSCH are examples of sidelink control channels and sidelink data channels, respectively. PBCH and PSBCH are examples of broadcast channels, respectively, and PRACH is an example of a random access channel.

[0084] (Data channel / Control channel) This disclosure may apply to either data channels or control channels. The channels in this disclosure may be replaced with data channels including PDSCH, PUSCH, and PSSCH, and / or control channels including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0085] (reference signal) In this disclosure, a reference signal is a signal known to both the base station and the mobile station, and each reference signal may be referred to as a reference signal (RS) or pilot signal. A reference signal may be one of the following: Demodulation RS (DMRS), Channel State Information - Reference Signal (CSI-RS), Tracking Reference Signal (TRS), Phase Tracking Reference Signal (PTRS), Cell-specific Reference Signal (CRS), or Sounding Reference Signal (SRS).

[0086] (Time interval) In this disclosure, a time resource unit is not limited to one or a combination of slots and symbols, but may be a frame, superframe, subframe, slot, subslot of a time slot, minislot, or a time resource unit such as a symbol, an orthogonal frequency division multiplexing (OFDM) symbol, a single-carrier frequency division multiplexing access (SC-FDMA) symbol, or other time resource units. The number of symbols contained in one slot is not limited to the number of symbols exemplified in the embodiments described above, but may be any other number of symbols.

[0087] (Frequency band) This disclosure may apply to either the licensed band or the unlicensed band.

[0088] (communication) This disclosure may apply to any of the following: communication between a base station and a terminal (Uu-link communication), communication between terminals (side-link communication), and vehicle-to-everything (V2X) communication. The channels in this disclosure may be replaced with PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0089] Furthermore, this disclosure may apply to terrestrial networks or non-terrestrial networks (NTNs) that use satellites or high-altitude pseudo-satellites (HAPS). It may also apply to networks with large cell sizes or terrestrial networks with large latency relative to symbol length or slot length, such as ultra-wideband transmission networks.

[0090] (Antenna port) An antenna port refers to a logical antenna (antenna group) formed by one or more physical antennas. That is, an antenna port does not necessarily refer to a single physical antenna, but may also refer to an array antenna formed by multiple antennas. For example, the number of physical antennas forming an antenna port is not defined; instead, an antenna port is defined as the smallest unit on which a terminal can transmit a reference signal. Alternatively, an antenna port can be defined as the smallest unit for multiplying the weights of a precoding vector.

[0091] As described above, embodiments of the present disclosure provide advanced communication systems, communication methods, and communication devices that advantageously perform RA-RNTI calculation for handling RO collisions in multi-PRACH transmissions.

[0092] This disclosure can be implemented by software, by hardware, or by software working in conjunction with hardware. Each functional block used in the description of the embodiments above may be implemented in part or in whole as an integrated circuit (LSI), and each process described in the embodiments above may be controlled in part or in whole by one LSI or a combination of LSIs. An LSI may be formed individually as a chip, or a single chip may be formed to include some or all of the functional blocks. An LSI may include data input / output units coupled to itself. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs. However, the technology for implementing integrated circuits is not limited to LSIs and can be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (field-programmable gate arrays) that can be programmed after the manufacture of the LSI, or reconfigurable processors that can reconfigure the connections and settings of circuit cells located inside the LSI, can also be used. This disclosure can be implemented as digital or analog processing. If LSIs are replaced by future integrated circuit technologies as a result of advancements in semiconductor technology or other derivative technologies, functional blocks can be integrated using those future integrated circuit technologies. Biotechnology can also be applied.

[0093] This disclosure can be implemented by any type of device, apparatus, or system having communication capabilities (collectively referred to as communication apparatus).

[0094] Such communication devices are not limited to a few examples and include a variety of combinations of telephones (e.g., mobile phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still cameras / video cameras), digital players (e.g., digital audio players / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, and vehicles that provide communication capabilities (e.g., automobiles, airplanes, ships).

[0095] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0096] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0097] The communication device may include devices such as controllers and sensors coupled to a communication device that performs the communication functions described in this disclosure. For example, this may include controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0098] Communication equipment may further include base stations, access points, and any other devices, devices, or systems that communicate with or control infrastructure equipment, such as the devices in the non-limiting examples above.

[0099] While some characteristics of various embodiments are described with reference to the apparatus, it will be understood that the corresponding characteristics also apply to the methods of various embodiments, and vice versa.

[0100] This disclosure may be referenced to the following statement.

[0101] <Statement 1> During operation, a circuit determines one or more random access radio network temporary identifiers (RA-RNTIs) based on a first group of resources and / or a second group of resources in a random access channel opportunity (RO) group. During operation, a transmission unit transmits a preamble in at least one of the first plurality of resources, During operation, the system includes a receiving unit that receives Downlink Control Information (DCI) including a cyclic redundancy check (CRC) scrambled by one or more RA-RNTIs in response to the transmission of the preamble, Communication device.

[0102] The advantage of this feature is that it allows the UE to successfully decode the corresponding RAR for a multi-PRACH transmission even if a certain number of ROs within an RO group may be dropped, or if one of the actual PRACH transmissions in an active RO fails to reach the gNB.

[0103] <Statement 2> The communication device described in Statement 1, wherein the first plurality of resources are multiple radio resources of multiple ROs in the RO group.

[0104] The advantage of this feature is that it allows the UE to know which resources to use in calculating RA-RNTI.

[0105] <Statement3> The communication device according to Statement 2, wherein the plurality of ROs include at least one active RO and at least one inactive RO, and the circuit is configured to determine one or more RA-RNTIs based on at least one radio resource of the at least one inactive RO in the first plurality of resources.

[0106] The advantage of this feature is that it allows for the reuse of existing formulas for calculating RA-RNTI, minimizing the impact on standards.

[0107] <Statement 4> The communication device according to Statement 2, wherein the nth RO among the plurality of ROs is either an active RO or an inactive RO, where n is an integer in the range of 1 to the total number of the plurality of ROs, and the circuit is configured to determine one or more RA-RNTIs based on at least one radio resource of the nth RO in the first plurality of resources.

[0108] The advantage of this feature is that it allows for the reuse of existing formulas for calculating RA-RNTI, minimizing the impact on standards.

[0109] <Statement 5> The aforementioned n is a communication device as defined in Statement 4, which is notified by or pre-configured by upper-layer signaling, MAC CE signaling, or other DCI, or is defined in the technical specification.

[0110] The advantage of this feature is that it allows for more flexible configuration of RA-RNTI calculations based on n signaling.

[0111] <Statement 6> The communication device according to Statement 2, wherein the plurality of ROs include all ROs being active ROs, or including at least one active RO and at least one inactive RO.

[0112] The advantage of this feature is that it allows for the reuse of existing formulas for calculating RA-RNTI, minimizing the impact on standards.

[0113] <Statement 7> The communication device according to Statement 6, wherein the circuit is configured to determine one or more RA-RNTIs based on two or more radio resources of only active ROs in the first plurality of resources, or based on two or more radio resources of at least one active RO and at least one inactive RO in the first plurality of resources.

[0114] The advantage of this feature is that it allows for the reuse of existing formulas for RA-RNTI calculation using new range values ​​for parameters (e.g., s_id_sum, t_id_sum, f_id_sum) to minimize the impact on the standard.

[0115] <Statement 8> The communication device according to Statement 2, wherein the second plurality of resources are a plurality of dedicated resources associated with the RO group, and the circuit is configured to determine the one or more RA-RNTI based on the plurality of dedicated resources.

[0116] Since dedicated resources for RO groups can be pre-configured (for example, a table-based notification shows a list of dedicated time and frequency domain resources for all possible RO groups supported by the serving cell (e.g., 64 as the maximum number of preambles currently supported by the serving cell)), no additional signaling overhead is incurred for the purpose of RA-RNTI calculation.

[0117] <Statement 9> The communication device described in Statement 8, wherein the multiple dedicated resources are specific radio resources separate from the multiple RO radio resources in the RO group, or include an identification number, assignment index, or non-zero value.

[0118] Since dedicated resources for RO groups can be pre-configured (for example, a table-based notification shows a list of dedicated time and frequency domain resources for all possible RO groups supported by the serving cell (e.g., 64 as the maximum number of preambles currently supported by the serving cell)), no additional signaling overhead is incurred for the purpose of RA-RNTI calculation.

[0119] <Statement 10> The communication device according to Statement 1, wherein the circuit is configured to determine one or more RA-RNTIs based on the serving cells associated with the communication device.

[0120] Determining one or more RA-RNTIs between UEs based on the serving cell (i.e., a cell-specific method for determining one or more RA-RNTIs between UEs in the serving cell) minimizes complexity in the configuration and implementation of gNBs.

[0121] <Statement 11> The communication device according to any one of statements 1 or 10, wherein the circuit is configured to determine one or more RA-RNTIs based on the type of communication device.

[0122] The advantage of this feature is that gNB can set different, more flexible methods for determining one or more RA-RNTIs across different UE types.

[0123] <Statement 12> The communication device as described in Statement 1, wherein the circuit is configured to define notification of the determination of one or more RA-RNTIs via upper layer signaling, MAC CE signaling, or other DCI, or the determination of one or more RA-RNTIs is pre-configured or specified in the technical specifications.

[0124] The advantage of this feature is that the UE can determine the solution / method to use for determining one or more RA-RNTIs.

[0125] <Statement 13> The circuit is configured to determine one or more RA-RNTIs based on a function of the first plurality of resources and / or the second plurality of resources, the function being communicated by upper layer signaling, MAC CE signaling, or DCI, or specified in the technical specifications, as described in Statement 1.

[0126] The advantage of this feature is that it defines a specific function for determining one or more RA-RNTIs in the case of multi-PRACH transmissions.

[0127] <Statement 14> The circuit is configured to determine one or more RA-RNTIs based on a subset of the first and / or second and multiple resources, wherein the subset is notified by upper layer signaling, MAC CE signaling, or DCI, or specified in the technical specifications, as described in Statement 1.

[0128] The advantage of this feature is that it increases the number of possible RA-RNTI determination options.

[0129] <Statement 15> The communication device according to Statement 1, wherein the circuit is further configured to decode a Physical Downlink Shared Channel (PDSCH) that carries a Random Access Response (RAR) based on the determined one or more RA-RNTIs.

[0130] The advantages of this feature are that (i) the UE can decode the corresponding RAR of the multi-PRACH transmission, enabling the UE to understand that the multi-PRACH transmission has successfully reached the gNB, and (ii) the UE to know which radio resources should be used for the subsequent PUSCH transmission (also known as message 3 (Msg3)) in the random access procedure.

[0131] <Statement 16> During operation, a receiving unit receives a preamble from a second communication device in at least one of the first multiple resources of a Random Access Channel Occasion (RO) group, During operation, a circuit determines one or more random access radio network temporary identifiers (RA-RNTIs) based on the first and / or second and multiple resources, and generates Downlink Control Information (DCI) including a cyclic redundancy check (CRC) scrambled by the one or more RA-RNTIs, The system includes a transmitting unit that transmits the DCI to the second communication device during operation, The first communication device.

[0132] The advantage of this feature is that the UE can successfully decode the corresponding RAR for a multi-PRACH transmission even if a certain number of ROs in the RO group may be dropped, or if one of the actual PRACH transmissions in an active RO fails to reach the gNB.

[0133] <Statement 17> Based on a group of random access channel opportunities (ROs), one or more random access radio network temporary identifiers (RA-RNTIs) are determined from a group of first and / or second resources. Sending a preamble in at least one of the first multiple resources, The process includes receiving Downlink Control Information (DCI) which includes a cyclic redundancy check (CRC) scrambled by one or more RA-RNTIs in response to the transmission of the preamble, Communication method.

[0134] The advantage of this feature is that the UE can successfully decode the corresponding RAR for a multi-PRACH transmission even if a certain number of ROs in the RO group may be dropped, or if one of the actual PRACH transmissions in an active RO fails to reach the gNB.

[0135] Those skilled in the art will understand that numerous variations and / or modifications can be made to the Disclosure, as shown in the specific embodiments, without departing from the broader spirit or scope of the Disclosure. Therefore, these embodiments should be considered illustrative and not restrictive in all respects.

Claims

1. A circuit that, during operation, determines one or more random access radio network temporary identifiers (RA-RNTIs) based on a first group of resources and / or a second group of resources in a random access channel opportunity (RO) group, During operation, a transmission unit transmits a preamble in at least one of the first plurality of resources, The system includes a receiving unit that, during operation, receives Downlink Control Information (DCI) including cyclic redundancy checks (CRCs) scrambled by one or more RA-RNTIs in response to the transmission of the preamble, Communication device.

2. The first plurality of resources are the plurality of radio resources of the plurality of ROs in the RO group. The communication device according to claim 1.

3. The plurality of ROs include at least one active RO and at least one inactive RO, and the circuit is configured to determine one or more RA-RNTIs based on at least one radio resource of the at least one inactive RO in the first plurality of resources. The communication device according to claim 2.

4. The nth RO among the plurality of ROs is either an active RO or an inactive RO, where n is an integer within the range of 1 to the total number of ROs, and the circuit is configured to determine one or more RA-RNTIs based on at least one radio resource of the nth RO in the first plurality of resources. The communication device according to claim 2.

5. The aforementioned n is notified by higher-layer signaling, MAC CE signaling, or other DCI, or is pre-configured or defined in the technical specification. The communication device according to claim 4.

6. The plurality of ROs are such that all ROs are active ROs, or that at least one active RO and at least one inactive RO are included. The communication device according to claim 2.

7. The circuit is configured to determine one or more RA-RNTIs based on two or more radio resources consisting only of active ROs in the first plurality of resources, or based on two or more radio resources consisting of at least one active RO and at least one inactive RO in the first plurality of resources. The communication device according to claim 6.

8. The second plurality of resources are a plurality of dedicated resources associated with the RO group, and the circuit is configured to determine the one or more RA-RNTIs based on the plurality of dedicated resources. The communication device according to claim 1.

9. The aforementioned multiple dedicated resources include specific radio resources separate from the radio resources of the multiple ROs in the RO group, or include identification numbers, assignment indexes, or non-zero values. The communication device according to claim 8.

10. The circuit is configured to determine one or more RA-RNTIs based on the serving cell associated with the communication device. The communication device according to claim 1.

11. The circuit is configured to determine one or more RA-RNTIs based on the type of communication device. A communication device according to claim 1 or 10.

12. The circuit is configured to define notification of the determination of one or more RA-RNTIs via upper-layer signaling, MAC CE signaling, or other DCI, or the determination of one or more RA-RNTIs is pre-configured or specified in the technical specifications. The communication device according to claim 1.

13. The circuit is configured to determine one or more RA-RNTIs based on a function of the first plurality of resources and / or the second plurality of resources, the function being notified by upper layer signaling, MAC CE signaling, or DCI, or specified in the technical specifications. The communication device according to claim 1.

14. The circuit is configured to determine one or more RA-RNTIs based on a subset of the first and / or second sets of resources, the subset of which is notified by upper layer signaling, MAC CE signaling, or DCI, or specified in the technical specifications. The communication device according to claim 1.

15. The circuit is further configured to decode a Physical Downlink Shared Channel (PDSCH) that carries a Random Access Response (RAR) based on the determined one or more RA-RNTIs. The communication device according to claim 1.

16. During operation, a receiving unit receives a preamble from a second communication device in at least one of the first multiple resources of a Random Access Channel Occasion (RO) group, During operation, a circuit determines one or more random access radio network temporary identifiers (RA-RNTIs) based on the first and / or second and a plurality of resources, and generates Downlink Control Information (DCI) including a cyclic redundancy check (CRC) scrambled by the one or more RA-RNTIs, The system includes a transmitting unit that transmits the DCI to the second communication device during operation, The first communication device.

17. Determining one or more random access radio network temporary identifiers (RA-RNTIs) based on a first group of resources and / or a second group of resources in a random access channel opportunity (RO) group, Sending a preamble in at least one of the first multiple resources, The process includes receiving Downlink Control Information (DCI) which includes a cyclic redundancy check (CRC) scrambled by one or more RA-RNTIs in response to the transmission of the preamble, Communication method.

Images