Methods, communications devices, and infrastructure equipment

Abstract

Methods, communications devices, and infrastructure equipment are provided for validation of PRACH occasions or PUSCH occasions (TOs). In particular, when resource blocks for a TO are determined (which may include relocating a TO within an SBFD UL sub-band), TOs which are outside of the UL sub-band or that collide with another TO are invalidated. A PRACH preamble or PUSCH may then be received on one of the valid TOs. This applies in examples where the RBs for a TO may be determined based on a particular frequency offset, which is determined based on another frequency offset and the RBs of the UL sub-band.

Description

[0001] METHODS, COMMUNICATIONS DEVICES, AND INFRASTRUCTURE EQUIPMENT

[0002] The present application claims the Paris Convention priority of European patent application EP24192187.3, filed 31 July 2024, the contents of which are hereby incorporated by reference.

[0003] BACKGROUND

[0004] Field of Disclosure

[0005] The present disclosure relates to communications devices, infrastructure equipment, and methods for the more efficient and effective transmission of data in a wireless communications network.

[0006] Description of Related Art

[0007] The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

[0008] Previous generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support a wider range of services than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy such networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to continue to increase rapidly.

[0009] Current and future wireless communications networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic profiles and types than existing systems are optimised to support. For example, it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets, extended Reality (XR) and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of device, for example supporting high-definition video streaming, may be associated with transmissions of relatively large amounts of data with relatively low latency tolerance. Other types of device, for example used for autonomous vehicle communications and for other critical applications, may be characterised by data that should be transmitted through the network with low latency and high reliability. A single device type might also be associated with different traffic profiles / characteristics depending on the application(s) it is running. For example, different considerations may apply for efficiently supporting data exchange with a smartphone when it is running a video streaming application (high downlink data) as compared to when it is running an Internet browsing application (sporadic uplink and downlink data) or being used for voice communications by an emergency responder in an emergency scenario (data subject to stringent reliability and latency requirements).

[0010] In view of this there is expected to be a desire for current wireless communications networks, for example those which may be referred to as 5G or new radio (NR) systems / new radio access technology (RAT) systems, or indeed future 6G wireless communications, as well as future iterations / releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements.

[0011] SUMMARY OF THE DISCLOSURE

[0012] The present disclosure can help address or mitigate at least some of the issues discussed above. The invention is defined in the claims.

[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the present technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein:

[0016] Figure 1 schematically represents some aspects of an LTE-type wireless telecommunication system which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0017] Figure 2 schematically represents some aspects of a new radio access technology (RAT) wireless telecommunications system which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0018] Figure 3 is a schematic block diagram of an example infrastructure equipment and communications device which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0019] Figure 4 schematically represents a first example of non-overlapping sub-bands for uplink and downlink transmissions for sub-band full duplex (SBFD);

[0020] Figure 5 schematically represents second and third examples of non-overlapping sub-bands for uplink and downlink transmissions for SBFD;

[0021] Figure 6 schematically illustrates the components of a synchronisation signal block (SSB);

[0022] Figure 7 schematically illustrates an SSB burst set transmitted on SSB beams;

[0023] Figure 8 schematically illustrates a physical random access channel (PRACH) occasion (RO) configuration;

[0024] Figures 9A to 9D schematically illustrates valid and invalid ROs;

[0025] Figure 10 schematically illustrates an example of a time division duplexing (TDD) slot format configuration;

[0026] Figure 11 schematically illustrates an example of an SSB to RO mapping in an association period for a TDD slot format;

[0027] Figure 12 schematically illustrates an example of a set of NPRACH = 4 ROs for 4 x PRACH repetitions;

[0028] Figure 13 schematically illustrates an example of an overall SSB-RO association using a single PRACH configuration;

[0029] Figure 14 schematically illustrates an example of an SBFD RO configuration on a separate PRACH configuration;

[0030] Figure 15 shows how an SBFD RO may be configured outside of an UL SBFD subband based on the parameter msgl -FrequencyStart,

[0031] Figure 16 shows how reinterpreting the parameter msgl -FrequencyStart such that it is defined with respect to the start of an UL SBFD subband rather than with respect to the start of the slot can lead to an SBFD RO being configured outside of the slot; Figure 17 illustrates a first example of how re-interpreting the parameter msgl-FrequencyStart based on application of a MOD function can lead to SBFD ROs being wholly contained within an UL SBFD subband but where the SBFD ROs may not be contiguous;

[0032] Figure 18 illustrates a second example of how re-interpreting the parameter msgl -FrequencyStart based on application of a MOD function can lead to SBFD ROs being wholly contained within an UL SBFD subband but where there may be a collision between some of the SBFD ROs;

[0033] Figure 19 illustrates an example whereby a relocated RO is invalidated based on colliding with another RO, or alternatively where a RO is not relocated based on a determination that the RO would collide with another RO if it were relocated;

[0034] Figure 20 illustrates an example whereby a relocated RO collides with an existing RO and replaces the existing RO within the UL sub-band;

[0035] Figure 21 illustrates an example of frequency misalignment between SBFD and non SBFD OFDM symbols;

[0036] Figure 22 illustrates an example of frequency misalignment between SBFD and non SBFD OFDM symbols;

[0037] Figure 23 illustrates an example whereby an RO that is partially outside an UL sub-band is relocated to be wholly within the UL sub-band;

[0038] Figure 24 illustrates an example whereby ROs are indexed after the frequency resources of the RBs has been determined, including after one or more ROs have been relocated to be within the UL sub-band, and after any ROs have been invalidated;

[0039] Figure 25 illustrates an RO spanning both SBFD and non-SBFD OFDM symbols utilising the sa,e frequency resources across the entire length duration of the RO.

[0040] Figure 26 illustrates a flowchart depicting a method of operating a communications device according to the present disclosure.

[0041] Figure 27 illustrates a flowchart depicting a method of operating a communications device according to the present disclosure.

[0042] Figure 28 illustrates a flowchart depicting a method of operating a communications device according to the present disclosure.

[0043] Figure 29 illustrates a flowchart depicting a method of operating an infrastructure equipment according to the present disclosure.

[0044] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] Long Term Evolution Advanced Radio Access Technology (4G)

[0046] Figure 1 provides a schematic diagram illustrating some basic functionality of a mobile telecommunications network / system 6 operating generally in accordance with LTE principles, but which may also support other radio access technologies, and which may be adapted to implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body, and also described in many books on the subject, for example, Holma H. and Toskala A [1], It will be appreciated that operational aspects of the telecommunications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

[0047] The network 6 includes a plurality of base stations 1 connected to a core network 2. Each base station provides a coverage area 3 (i.e. a cell) within which data can be communicated to and from communications devices 4. Although each base station 1 is shown in Figure 1 as a single entity, the skilled person will appreciate that some of the functions of the base station may be carried out by disparate, inter-connected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

[0048] Data is transmitted from base stations 1 to communications devices 4 within their respective coverage areas 3 via a radio downlink (DL). Data is transmitted from communications devices 4 to the base stations 1 via a radio uplink (UL). The core network 2 routes data to and from the communications devices 4 via the respective base stations 1 and provides functions such as authentication, mobility management, charging and so on. Communications devices may also be referred to as mobile stations, user equipment (UEs), user terminals, mobile radios, mobile terminals, terminal devices, wireless transmit and receive units (WTRUs), and so forth. Services provided by the core network 2 may include connectivity to the internet or to external telephony services. The core network 2 may further track the location of the communications devices 4 so that it can efficiently contact (i.e. page) the communications devices 4 for transmitting downlink data towards the communications devices 4.

[0049] Base stations, which are an example of network infrastructure equipment, may also be referred to as transceiver stations, nodeBs, e-nodeBs, eNB, g-nodeBs, gNB and so forth. In this regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality. However, certain embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

[0050] New Radio Access Technology (5G)

[0051] Systems incorporating NR technology are expected to support different services (or types of services), which may be characterised by different requirements for latency, data rate and / or reliability. For example, Enhanced Mobile Broadband (eMBB) services are characterised by high capacity with a requirement to support up to 20 Gb / s. The requirements for Ultra Reliable and Low Latency Communications (URLLC) services are for one transmission of a 32 byte packet to be transmitted from the radio protocol layer 2 / 3 SDU ingress point to the radio protocol layer 2 / 3 SDU egress point of the radio interface within 1 ms with a reliability of 1 - 10'5(99.999 %) or higher (99.9999%) [2],

[0052] Massive Machine Type Communications (mMTC) is another example of a service which may be supported by NR-based communications networks. In addition, systems may be expected to support further enhancements related to Industrial Internet of Things (IIoT) in order to support services with new requirements of high availability, high reliability, low latency, and in some cases, high-accuracy positioning.

[0053] An example configuration of a wireless communications network which uses some of the terminology proposed for and used in NR and 5G is shown in Figure 2. In Figure 2 a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 by a connection interface represented as a line 16. Each of the TRPs 10 is arranged to transmit and receive signals via a wireless access interface within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 10, forms a cell of the wireless communications network as represented by a circle 12. As such, wireless communications devices 14 which are within a radio communications range provided by the cells 12 can transmit and receive signals to and from the TRPs 10 via the wireless access interface. Each of the distributed units 41, 42 are connected to a central unit (CU) 40 (which may be referred to as a controlling node) via an interface 46. The central unit 40 is then connected to the core network 20 which may contain all other functions required to transmit data for communicating to and from the wireless communications devices and the core network 20 may be connected to other networks 25.

[0054] The elements of the wireless access network shown in Figure 2 may operate in a similar way to corresponding elements of an LTE network as described with regard to the example of Figure 1. It will be appreciated that operational aspects of the telecommunications network represented in Figure 2, and of other networks discussed herein in accordance with embodiments of the disclosure, which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to currently used approaches for implementing such operational aspects of wireless telecommunications systems, e.g. in accordance with the relevant standards.

[0055] The TRPs 10 of Figure 2 may in part have a corresponding functionality to a base station or eNodeB of an LTE network. Similarly, the communications devices 14 may have a functionality corresponding to the UE devices 4 known for operation with an LTE network. It will be appreciated therefore that operational aspects of a new RAT network (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be different to those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network component, base stations and communications devices of a new RAT network will be functionally similar to, respectively, the core network component, base stations and communications devices of an LTE wireless communications network.

[0056] In terms of broad top-level functionality, the core network 20 connected to the new RAT telecommunications system represented in Figure 2 may be broadly considered to correspond with the core network 2 represented in Figure 1, and the respective central units 40 and their associated distributed units / TRPs 10 may be broadly considered to provide functionality corresponding to the base stations 1 of Figure 1. The term network infrastructure equipment / access node may be used to encompass these elements and more conventional base station type elements of wireless telecommunications systems. Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the communications devices may lie with the controlling node / central unit and / or the distributed units / TRPs. A communications device 14 is represented in Figure 2 within the coverage area of the first communication cell 12. This communications device 14 may thus exchange signalling with the first central unit 40 in the first communication cell 12 via one of the distributed units / TRPs 10 associated with the first communication cell 12.

[0057] It will further be appreciated that Figure 2 represents merely one example of a proposed architecture for a new RAT based telecommunications system in which approaches in accordance with the principles described herein may be adopted, and the functionality disclosed herein may also be applied in respect of wireless telecommunications systems having different architectures.

[0058] Thus, certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architectures shown in Figures 1 and 2. It will thus be appreciated the specific wireless telecommunications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a communications device, wherein the specific nature of the network infrastructure equipment / access node and the communications device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a base station, such as an LTE- type base station 1 as shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment may comprise a control unit / controlling node 40 and / or a TRP 10 of the kind shown in Figure 2 which is adapted to provide functionality in accordance with the principles described herein.

[0059] A more detailed diagram of some of the components of the network shown in Figure 2 is provided by Figure 3. In Figure 3, a TRP 10 as shown in Figure 2 comprises, as a simplified representation, a wireless transmitter 30, a wireless receiver 32 and a controller or controlling processor 34 which may operate to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within a cell 12 formed by the TRP 10. As shown in Figure 3, an example UE 14 is shown to include a corresponding transmitter 49, a receiver 48 and a controller 44 which is configured to control the transmitter 49 and the receiver 48 to transmit signals representing uplink data to the wireless communications network via the wireless access interface formed by the TRP 10 and to receive downlink data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with the conventional operation.

[0060] The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers and transceivers described in relation to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices in order to transmit and receive radio signals in accordance for example with the 5G / NR standard. The controllers 34, 44 (as well as other controllers described in relation to examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc., configured to carry out instructions which are stored on a computer readable medium, such as a non-volatile memory. The processing steps described herein may be carried out by, for example, a microprocessor in conjunction with a random access memory, operating according to instructions stored on a computer readable medium. The transmitters, the receivers and the controllers are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the infrastructure equipment / TRP / base station as well as the UE / communications device will in general comprise various other elements associated with its operating functionality.

[0061] As shown in Figure 3, the TRP 10 also includes a network interface 50 which connects to the DU 42 via a physical interface 16. The network interface 50 therefore provides a communication link for data and signalling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

[0062] The interface 46 between the DU 42 and the CU 40 is known as the F 1 interface which can be a physical or a logical interface. The Fl interface 46 between CU and DU may operate in accordance with specifications 3GPP TS 38.470 and 3GPP TS 38.473, and may be formed from a fibre optic or other wired or wireless high bandwidth connection. In one example the connection 16 from the TRP 10 to the DU 42 is via fibre optic. The connection between a TRP 10 and the core network 20 can be generally referred to as a backhaul, which comprises the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the Fl interface 46 from the DU 42 to the CU 40. In order for a UE such as UE 4 or 14 to transmit uplink data to the network (e.g. on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH)) to, for example, base station 1 or TRP 10, the UE must first ensure it is synchronised with the network on the uplink. Since a particular eNB or gNB expects to be receiving communications from many UEs, it needs to ensure that it shares a common timing understanding with each of these UEs (i.e. they are synchronised in terms of the starting times of frames and Orthogonal Frequency Division Multiplexing (OFDM) symbols (often referred to simply as “symbols” for brevity)). This is so that the eNB is able to schedule communication with each of them in a manner that avoids collisions and to ensure orthogonality of the uplink signals, such that intersubcarrier interference is avoided or mitigated.

[0063] Although reference is made to 5G networks, the discussions in this specification apply equally to 6G networks (and beyond) where there is expected to be significantly higher throughput, lower latency and higher reliability utilising sub-THz frequencies.

[0064] Full Duplex Time Division Duplex (FD-TDD)

[0065] NR / 5G networks can operate using Time Division Duplex (TDD), where an entire frequency band or carrier is switched to either downlink or uplink transmissions for a time period and can be switched to the other of downlink or uplink transmissions at a later time period. Currently, TDD operates in Half Duplex mode (HD-TDD) where the gNB or UE can, at a given time, either transmit or receive packets, but not both at the same time. As wireless networks transition from NR to 5G-Advanced networks, a proposed new feature of such networks is to enhance duplexing operation for Time Division Duplex (TDD) by enabling Full Duplex operation in TDD (FD-TDD) [3], [4],

[0066] In FD-TDD, a gNB can transmit and receive data to and from the UEs at the same time on the same frequency band. In addition, a UE can operate either in HD-TDD or FD-TDD mode, depending on its capability. For example, when UEs are only capable of supporting HD-TDD, FD-TDD is achieved at the gNB by scheduling a DL transmission to a first UE and scheduling an UL transmission from a second UE within the same OFDM symbol (i.e. at the same time). Conversely, when UEs are capable of supporting FD-TDD, FD-TDD is achieved both at the gNB and the UE, where the gNB can simultaneously schedule this UE with DL and UL transmissions within the same OFDM symbol by scheduling the DL and UL transmissions at different frequencies (e.g. physical resource blocks (PRBs)) of the system bandwidth. A UE supporting FD-TDD requires more complex hardware than a UE that only supports HD-TDD. Development of current 5G networks is focused primarily on enabling FD-TDD at the gNB with UEs operating in HD-TDD mode.

[0067] Motivations for enhancing duplexing operation for TDD include an improvement in system capacity, reduced latency, and improved uplink coverage. For example, in current HD-TDD systems, OFDM symbols are allocated only for either a DL or UL direction in a semi-static manner. Hence, if one direction experiences less or no data, the spare resources cannot be used in the other direction, or are, at best, underutilised. However, if resources can be used for DL data and UL data (as in FD-TDD) at the same time, the resource utilisation in the system can be improved. Furthermore, in current HD-TDD systems, a UE can receive DL data, but cannot transmit UL data at the same time, which causes delays. If a gNB or UE is allowed to transmit and receive data at the same time (as with FD-TDD), the traffic latency will be improved. In addition, UEs are usually coverage limited in their UL transmissions when located close to the edge of a cell. While the UE coverage at the cell -edge can be improved if more time domain resources are assigned to UL transmissions (e.g. repetitions), for HD-TDD systems, if the UL direction is assigned more time resources, fewer time resources can be assigned to the DL direction, which can lead to system imbalance. In contrast, in FD-TDD, continuous UL resources can be assigned for repetition opportunities whilst allowing DL traffic to occur in those resources, thereby UL enhancing coverage without causing system imbalance.

[0068] A Rel-19 Work Item (WI) [5] on Duplex Evolution is therefore agreed to specify the requirements for FD- TDD. In Rel-19 Duplex Evolution, FD-TDD is performed at the gNB, where the gNB can transmit and receive data / signals to / from the UEs at the same time on the same frequency band, whilst the UE is maintained as HD-TDD. That is, full duplex TDD is achieved at the gNB by scheduling a UE in the DL and scheduling another UE in the UL within the same OFDM symbol. One of the objectives of the Rel-19 Duplex Evolution WI [5] is to support RACH operation in Sub-band Full Duplex (SBFD) OFDM symbols.

[0069] Sub-band Full Duplex (SBFD)

[0070] In SBFD, the frequency resource of a TDD system bandwidth or Bandwidth Part (BWP) (i.e. at the UE / gNB) is divided into two or more non-overlapping sub-bands, where each sub-band can be DL or UL [6], Guard sub-bands may be used between DL and UL sub-bands to reduce inter sub-band interference. In the current 5G system, only one UL sub-band can be configured in an OFDM symbol.

[0071] An example is shown in Figure 4, where simultaneous DL and UL transmissions occur in three different non-overlapping sub-bands 61 to 63, i.e. in different sets of frequency Resource Blocks (RB): Sub-band# 1

[0072] 61, Sub-band#2 62, Sub-band#3 63. The example of Figure 4 is referred to as {DUD}, because two subbands, Sub-band# 1 61 and Sub-band#3 63, are used for DL transmissions whilst one sub-band, Sub-band#2

[0073] 62, is used for UL transmissions. To reduce leakage from one sub-band 61 to 63 to another, a guard subband 64 may be configured between UL and DL sub-bands 61 to 63. Guard sub-bands 64 are configured between DL Sub-band#3 63 and UL Sub-band#2 62 and between UL Sub-band#2 62 and DL Sub-band# 1 61.

[0074] Figure 5 shows two further examples with a DL and UL sub-band separated by a guard sub-band, where here, the UL sub-band can be configured to occupy the lower frequency portion of the BWP whilst the DL sub-band occupies higher frequency portion of the BWP {UD} or the UL sub-band occupies the higher frequency portion of the BWP whilst the DL sub-band occupies lower frequency portion of the BWP {DU} . Here, on the left-side of Figure 5, an UL sub-band# 1 71 is separated from a DL sub-band#2 73 by a guard sub-band 72 - this sub-band arrangement is referred to as {UD}. In this case, the DL sub-band#2 73 occupies a higher frequency portion of the system bandwidth than the UL sub-band# 1 71. On the rightside of Figure 5, a DL sub-band# 1 81 is separated from an UL sub-band#2 83 by a guard sub-band 82 - this sub-band arrangement is referred to as {DU}. In this case, the UL sub-band#2 83 occupies a higher frequency portion of the system bandwidth than the DL sub-band# 1 81.

[0075] While Figures 4 and 5 show the system bandwidth as being divided into either two or three sub-bands, those skilled in the art would appreciate that the concept of SBFD may (in further releases of the 3GPP specifications, for example) be extended such that any number of sub-bands could be used, if deemed beneficial. For example, the system bandwidth may be divided into four sub-bands, which may, using the example of Figure 4, include the two downlink sub-bands 61, 63, the uplink sub-band 62 and another uplink sub-band, though other sub-band arrangements are envisioned. Guard sub-bands may be used in substantially any sub-band arrangement.

[0076] Synchronisation Signal Block

[0077] As will be known to one skilled in the art, the Synchronisation Signal Block (SSB) is used for initial access and cell reselection. An example of an SSB is schematically illustrated in Figure 6. As shown in Figure 6, the SSB comprises of a Primary Synchronisation Signal (PSS), a Secondary Synchronisation Signal (SSS) and a Physical Broadcast Channel (PBCH). The SSB comprises information for a communications device, such as a UE, to detect, measure and access a cell. The SSB shown in Figure 6 comprises four OFDM symbols and 240 subcarriers. The PSS and SSS each occupy 127 subcarriers. The PBCH occupies two OFDM symbols of 240 subcarriers and also two blocks of 48 subcarriers at the top and bottom of the SSS. The SSB may be configured with a periodicity, PSSB, of between 5 ms and 160 ms.

[0078] An SSB burst set comprises a set of one or more time -multiplexed SSBs. Each SSB is transmitted in a burst set using a different downlink beam, thereby enabling beam sweeping to be implemented for SSB. An SSB burst set may be confined within 5 ms and may comprise up to 4, 8 and 64 SSBs for frequency bands below 3 GHz, between 3 GHz - 6 GHz and for FR2 respectively. As will be understood by one skilled in the art, SSB burst sets may be periodically transmitted.

[0079] An example SSB burst set in the case of 3 GHz - 6 GHz frequency is shown in Figure 7. The SSB burst set shown in Figure 7 comprises eight SSBs labelled as SSB#1, SSB#2, SSB#3, SSB#4, SSB#5, SSB#6, SSB#7 and SSB#8 respectively. Each of the SSBs in the burst set is transmitted using a different downlink beam. In this example, two SSBs are configured per slot within four slots. Furthermore, the burst set is transmitted with a periodicity, PSSB, of 20 ms. Although not shown in Figure 7, the SSB burst set is transmitted by infrastructure equipment of a wireless communications network (such as a gNB) and received by a communications device (such as a UE).

[0080] The UE measures a signal quality of each SSB in the SSB burst set. The UE may then select one of the downlink beams based on the measured signal quality. For example, the UE may select the downlink beam with the highest measured signal quality provided that the measure signal quality is above a threshold (such as RSRP threshold). Then, the UE determines an uplink beam corresponding to the downlink beam to use for synchronisation with the infrastructure equipment. As will be appreciated by one skilled in the art, corresponding uplink and downlink beams form beam pairs which overlap. Therefore, the measurements of the signal quality of a downlink beam are an indication of the signal quality of the corresponding uplink beam in the beam pair. In initial access, the UE transmits RACH on the determined uplink beam.

[0081] In one example, the measured signal quality of an SSB is an RSRP of the SSB. The UE may measure the RSRP of each SSB in the SSB burst set and select the downlink beam on which the SSB with the highest RSRP was transmitted provided this measured RSRP is above a threshold (such as rsrp-ThresholdSSB). Then, the UE transmits its RACH using the corresponding uplink beam.

[0082] The measurement of the RSRP of an SSB may be referred to as “SS-RSRP”. The measurement of the RSRP of an SSB may comprise measuring the RSRP on resource elements where SSS is transmitted. Alternatively, or in addition, the measurement of the RSRP of an SSB may comprise measuring the RSRP on resource elements where PBCH Demodulation Reference Signals (DMRS) are transmitted.

[0083] In other examples, the measured signal quality of an SSB may be a Reference Signal Received Quality (SS- RSRQ) of the SSB. The SS-RSRQ is defined as the ratio of N x SS-RSRP / RSSI (Received Signal Strength Indicator), where N is the number of resource blocks. For example, the RSSI in NR is measured in one or more OFDM symbols in a SS / PBCH Block Measurement Time Configuration (SMTC). The SMTC is a configuration to the UE to set time window for measurement by using SSB. The OFDM symbols used for RSSI measurement can be configured by higher layers. PRACH Occasions

[0084] As will be understood by a person skilled in the art, a Physical Random Access (PRACH) configuration comprises a plurality of PRACH Occasions (RO) configured in uplink communications resources of a wireless access interface. The ROs in a PRACH configuration may be periodically repeating. The ROs represent transmission opportunities for a UE to transmit a PRACH. Each RO may be configured to support up to 64 preambles. In this case, each RO may support a PRACH transmission of up to 64 UEs if each UE uses a different preamble for its PRACH transmission. The ROs may be Frequency Division Multiplexed (FDM) where infrastructure equipment of a wireless communications network can configure using the parameter msgl -FDM = { 1, 2, 4, 8} FDM ROs for UEs. The start of the first RO is indicated by the network using the RRC parameter msgl-FrequencyStart, and the rest of the ROs are sequentially mapped one after the other in the frequency domain.

[0085] As mentioned above, ROs are configured in communications resources of a wireless access interface. Communications resources are comprised of time resources and frequency resources. The time resources of the ROs in a PRACH Occasion configuration are determined by a “PRACH Configuration Index”, which is an index to Tables 6.3.3.2-2, 6.3.3.2-3 and 6.3.3.2-4 in [7], which is hereby incorporated by reference in its entirety. There are 256, 263 and 256 PRACH configurations for FR1 FDD, FR1 TDD and FR2 respectively. The PRACH configuration index indicates a PRACH preamble format, a PRACH periodicity (known as a “PRACH Configuration Period”), a number of PRACH Occasions within a PRACH period, the starting symbol of the PRACH Occasion in a slot, and a duration of the PRACH Occasion.

[0086] An example PRACH Occasion configuration for an FR1 FDD system is shown Figure 8. The PRACH Occasion is configured with FDM = 2 and with a PRACH Configuration Index = 184. The time resources of the ROs in the PRACH Occasion can be obtained from Table 6.3.3.2-2 of [7] : The PRACH Configuration Period = 20 ms since an RO occurs in every even numbered system frame number (SFN) (x = 2 and y = 0). In each even numbered SFN, subframe 4 and 9 contain a slot with ROs, i.e., PRACH slot. In this example a 15 kHz subcarrier spacing is assumed and so each subframe which is 1 ms contains 1 slot. In each PRACH slot (i.e. in subframe 4 and 9), there are seven sets of time domain ROs where each RO is two OFDM symbols long. Since FDM = 2, each time domain RO has two ROs, and this gives 14 ROs in a PRACH slot as shown in Figure 8. There are therefore 28 ROs in a PRACH Configuration Period of 20 ms (2 PRACH slots in 20ms x 7 time domain ROs x 2 FDM = 28 ROs).

[0087] SSB to PRACH Occasion Association

[0088] A UE may select an SSB received on a DL beam and transmit a PRACH using a corresponding UL beam. The gNB needs to know which SSB the UE has selected so that it can transmit a Random Access Response (RAR) to the UE using the same SSB beam selected by the UE, or a beam derived from the UE selected SSB beam. Since the UE uses an UL beam, the gNB may maximise its reception by tuning its receiver panels towards the direction of the UL beam. Since ROs and SSBs are configured independently, an SSB- RO association is used for the gNB to determine the UE selected SSB, so that the gNB can determine the SSB selected by the UE based on the RO and preamble used for the UE’s PRACH transmission.

[0089] In SSB-RO association, each SSB is associated with one or more ROs and preambles. Infrastructure equipment of a wireless communications network (such as a gNB) transmits an indication of a number of SSBs associated with each RO and a number of preambles associated with each SSB. For example, the infrastructure equipment may transmit the following RRC parameter to the UE: ssb-perRACH- OccasionAndCB-PreamblesPerSSB . The values for SSB to RO association may be { 1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16}. In other words, SSB may be associated with 8, 4, 2 or 1 ROs, and an RO may be associated with 2, 4, 8 or 16 SSBs. In each RO, the SSB may be configured to associate with a subset of the 64 preambles or all of the 64 preambles. For the case where an RO is associated with 2, 4, 8 or 16 SSBs, each SSB may only be associated with a subset of the preambles in an RO. For example, if an RO is associated with two SSBs, then each SSB can occupy at most 32 preambles in that RO. For the case where an SSB is associated with one or more ROs, the SSB can occupy all of the 64 preambles although it can be configured to occupy fewer than 64 preambles.

[0090] Once the SSB parameters, RO parameters and SSB-RO association parameters are configured, the UE may then perform the following steps in sequential order:

[0091] 1. Valid ROs determination;

[0092] 2. Indexing the valid ROs; and

[0093] 3. Perform SSB-RO mapping.

[0094] Valid ROs Determination

[0095] For FDD all configured ROs are valid. However, for TDD, the following three legacy validity conditions must be met for an RO to be valid:

[0096] • A valid RO is contained fully in UL OFDM symbols since PRACH cannot be transmitted in DL OFDM symbols;

[0097] • In addition to being fully contained in UL OFDM symbols, there also needs to be a gap of NgapOFDM symbols between the end of an SSB and the start of the valid RO. The value of Ngapdepends on the subcarrier spacing of the PRACH and it is defined in [8], the contents of which are hereby incorporated by reference in their entirety; and

[0098] • If an RO and an SSB falls within a PRACH slot, the RO is invalid if it precedes the SSB.

[0099] Examples of valid and invalid ROs are shown in Figures 9A to 9D. The valid RO shown in Figure 9A meets all three validity conditions as detailed above. However, the invalid ROs as shown in Figures 9B, 9C, and 9D each fail to meet one of these validity conditions. The RO of Figure 9B is invalid because it falls within DL OFDM symbols. The RO of Figure 9C is invalid because there is an insufficient gap between the SSB and the RO. The RO of Figure 9D is invalid because the RO precedes the SSB within the PRACH slot.

[0100] RO Indexing

[0101] Once the valid ROs are determined, they are indexed in the following order:

[0102] 1. First, in increasing order of preamble indexes within a single RO;

[0103] 2. Second, in increasing order of frequency resource indexes for frequency multiplexed RO;

[0104] 3. Third, in increasing order of time resource indexes for time multiplexed PRACH occasions within a PRACH slot; and

[0105] 4. Fourth, in increasing order of indexes for PRACH slots.

[0106] SSB-RO Mapping

[0107] The SSBs are then mapped to the indexed ROs sequentially by RO index. This mapping is repeated every “SSB-RO Association Period”. The SSB-RO association period is the smallest integer number of PRACH Configuration Periods required for all the SSBs in an SSB burst set to fully map to RO(s) at least once. In an SSB-RO association period, if any remaining ROs cannot fully map all the SSBs of an SSB burst set, they are invalid ROs and are not used for PRACH transmissions. The allowed SSB-RO association periods for each PRACH Configuration Period are listed in Table 8.1-1 of [8], which is reproduced below as Table I. Table I: PRACH Configuration Period and SSB-RO association period (reproduced from [8])

[0108] An example of an SSB to RO mapping for an SSB-RO association period will now be explained. Figure 10 illustrates a legacy TDD slot format {DDDDU}, consisting of four DL slots followed by an UL slot as shown in Figure 10, and operating in 15 kHz subcarrier spacing. SSB and PRACH are configured as follows:

[0109] • SSB burst set has 5 SSBs {SSB#1, SSB#2, SSB#3, SSB#4, SSB#5};

[0110] • SSB per RO = 1 / 2; i.e., each SSB is mapped to two ROs;

[0111] • Preambles per SSB = 64, i.e., all preambles in an RO are fully mapped to an SSB;

[0112] • FDM RO = 2; and

[0113] • PRACH Configuration Index = 129 for FR1 TDD.

[0114] Using the lookup table in Table 6.3.3.2-3 of [7], the time resource configuration for PRACH Configuration Index = 129 has a PRACH Configuration Period = 10 ms. This is shown in Table II below, which reproduces a portion of this lookup table in Table 6.3.3.2-3 of [7],

[0115] Table II: PRACH Configuration Index 129 (reproduced from [7])

[0116] Figure 11 shows an example of SSB to RO mapping in an association period for the legacy TDD slot format, corresponding to PRACH configuration index 129 as shown in Table II above. Here, in each PRACH Configuration Period, Subframe 3, 4, 8 and 9 contain PRACH slots, and in each PRACH slot, there are two time domain ROs with duration six OFDM symbols each, which leads to 16 ROs in a PRACH Configuration Period (four PRACH slots x two time domain ROs per PRACH slot x two FDM ROs). Since a valid RO can only reside in UL OFDM symbols, only subframes 4 and 9 have valid ROs, and the ROs in subframes 3 and 8 are invalid ROs. Hence, each PRACH Configuration Period has eight valid ROs.

[0117] For a PRACH Configuration Period = 10 ms, referring to Table I as reproduced above (i.e., from Table 8.1-

[0118] 1 of [8]), the required SSB-RO association Period to fully map all five SSBs with SSB per RACH = 1 / 2 is

[0119] 2 x PRACH Configuration period (20 ms), giving 2 * 8 = 16 valid ROs. The 16 valid ROs in the 20 ms SSB-RO association period are indexed firstly by preamble, secondly by frequency, thirdly by time, and lastly by PRACH slot as shown in Figure 11. The SSBs are then mapped to the indexed ROs sequentially; e.g., since SSB per RO = 1 / 2, SSB#1 is mapped to RO#1 and RO#2, followed by SSB#2 being mapped to RO#3 and RO#4, etc. The five SSBs are fully mapped to the ROs once in the SSB-RO association period, leaving six remaining ROs: RO# 11, RO# 12, RO# 13, RO# 14, RO# 15 and RO# 16 that cannot fully map to another set of five SSBs. Hence these six remaining ROs are Invalid ROs, and are not used for PRACH transmissions.

[0120] PRACH Repetitions

[0121] The concept of using PRACH repetitions is introduced in Rel-18 to enhance the uplink coverage of PRACH. The PRACH repetition factor is NPRACH = {2, 4, 8}, where the PRACH is transmitted multiple times in different ROs using the same transmission beam and the same preamble. The set of ROs used for a specific PRACH repetition NPRACH consists of valid ROs that are associated with one SSB (i.e., the selected SSB) and uses the same frequency resources.

[0122] Figure 12 is an example of a set of NRRACH ROS for a PRACH repetition of four, i.e. NRRACH = 4, using the PRACH configurations as described in Figure 11. Figure 12 shows four SSB-RO association periods (each lasting 20 ms), spanning eight radio frames from SFN k to SFN k + ~I. where in each SSB-RO association period, the five SSBs are mapped to ten ROs. Assuming the UE selected SSB#2, and requires 4 x PRACH repetitions, it has a choice between two sets of NPRACH=4 ROS, i.e. one that starts with RO#3 (the lower frequency RO) in SFN k and another that starts with RO#4 (the higher frequency RO) in SFN k. Here, the UE selects RO#3 in SFN k as the start of the PRACH repetition. The remaining ROs in the set of NRRACH=^ ROs are associated with the same SSB#2 and located in the same frequency; that is, the set of NPRACH =4 ROs are RO#3 in SFN k, SFN k + 2, SFN k + 4 and SFN k + 6, which are outlined in dashed boxes in the example of Figure 12.

[0123] The first set of NPRACH ROS starts from SFN 0 and there may be a gap of TimeOffsetBetweenStartingRO valid ROs between each set of NPRACH ROS. The value of TimeOffsetBetweenStartingRO is configured by the network.

[0124] SBFD ROs

[0125] In the current system, there are two methods to configure ROs for SBFD (i.e. ROs that can be configured in SBFD sub-bands and hence are usable by SBFD-capable UEs), which are also described in co-pending European patent application number EP24155834.5 [9], the contents of which are hereby incorporated by reference. That is:

[0126] • Single PRACH Configuration: SBFD ROs and legacy ROs are configured in a single PRACH configuration; and

[0127] • Additional PRACH Configurations: SBFD ROs and legacy ROs are configured in separate PRACH configurations, i.e., an additional / separate PRACH configuration is used for SBFD ROs.

[0128] For each of these SBFD RO configuration methods, SBFD UEs will need to perform the SSB-RO association twice, where the first of these is performed on valid ROs that are validated using legacy RO validation rules, and the second SSB-RO association for SBFD RO is performed using new RO validation rules. Such new RO validation rules for SBFD RO are introduced, where an RO is valid if it resides fully within an UL sub-band and does not overlap with SSB.

[0129] The SSB-RO association for SBFD RO has not yet been specified, but a potential overall SSB-RO association is shown in Figure 13, where the example PRACH configuration as used in the example in Figure 11 is used again here (i.e. corresponding to PRACH configuration index 129 as shown in Table II). Here, an {XXXXU} SBFD slot format is assumed, where “X” is a slot consisting of SBFD OFDM symbols, where in the example in Figure 13, the SBFD slots consists of a {DUD} sub-band arrangement in the frequency domain such as that shown in Figure 4. In the example of Figure 13, the UE performs an SSB-RO association using legacy RO validation rules for non-SBFD OFDM symbols, where it maps SSB#1 and SSB#2 to RO#1 and RO#2, and RO#3 and RO#4 respectively in Subframe 4 of SFN k, SSB#3 and SSB#4 to RO#5 and RO#6, and RO#7 and RO#8 respectively in Subframe 9 of SFN k, and SSB#5 to RO#9 and RO#10 in Subframe 4 of SFN k + 1. The UE performs a second SSB-RO association on SBFD OFDM symbols, where it maps SSB#1 and SSB#2 to RO#1 and RO#2, and RO#3 and RO#4 respectively in Subframe 3 of SFN k, SSB#3 and SSB#4 to RO#5 and RO#6, and RO#7 and RO#8 respectively in Subframe 8 of SFN k, and SSB#5 to RO#9 and RO#10 in Subframe 3 of SFN k + 1. The overall SSB-RO association combining the two SSB-RO associations is shown in Figure 13.

[0130] Table III below shows the parameters for an example SBFD RO using a separate PRACH configuration, i.e. the SBFD UE is configured with two PRACH configurations.

[0131] Table JJJ Dual T'R. U JI configuration'* tor legacy TDD and BFD R. l( JJ

[0132] Here the SBFD UE also performs two SSB-RO association with different RO validations but on different PRACH configurations, where a first SSB-RO association using legacy RO validation rules on the legacy PRACH configuration (PRACH Configuration Index = 127) and another SSB-RO association using the new SBFD RO validation rules on the additional PRACH configuration with PRACH Configuration Index = 125, as shown in Table IV below. The resultant SSB-RO mapping is shown in Figure 14, where the SBFD ROs occupies different frequency resources from the legacy TDD ROs.

[0133] Table TV: PRACH Configuration Indices 125 and 127 (reproduced from [7])

[0134] RO Frequency Start

[0135] One advantage of configuring SBFD ROs using the single PRACH configuration, whereby SBFD ROs and legacy ROs are configured in a single PRACH configuration, is that it can use the same PRACH configuration as that used for legacy operations. However, since legacy ROs are configured in UL OFDM symbols, the legacy ROs may be configured outside of the UL sub-band.

[0136] An example is shown in Figure 15, where with the same PRACH configuration as that in the example in Figure 13, i.e., PRACH Configuration Index = 129 with msgl-FDM = 2. The ROs under PRACH Configuration Index = 129, are in Subframes 3, 4, 8 and 9, where for the legacy UE, Subframe 3 and 8 are DL slots, and therefore the ROs in these slots are invalid as shown in Figure 15. That is, for legacy UE only ROs in UL slot, i.e., in Subframes 4 and 9 are valid, and they are labelled as RO#1 to RO#7. The frequency location of the RO is configured using msgl -FrequencyStart, which indicates the RB offset between the 1stFDM RO and the 1stRB in the BWP. In the example in Figure \5.msgl -FrequencyStart is configured such that the ROs are at the upper edge of the BWP. If a {DUD} SBFD sub-band is configured on the DL slots of the TDD pattern, the ROs in SBFD slots, i.e. in Subframe 3 and Subframe 8, may not be contained within the UL sub-band, which would not lead to any increase in RO capacity.

[0137] In

[0010] , it is proposed that the network should be responsible in ensuring that the ROs are contained within the UL sub-band. That is, the network should ensure that the parameter msgl -FrequencyStart places the ROs in frequencies that are in the UL sub-band even for legacy ROs in the UL slots, since the parameter msgl -FrequencyStart defines the starting frequency of the 1stRO for all ROs regardless whether it is in SBFD OFDM symbols or UL OFDM symbols. However, it is argued in

[0011] , that the ROs are typically scheduled at the edge of the BWP to avoid fragmenting PUSCH resources, and so for {DUD} SBFD subband configuration, the ROs may not fall within the central UL sub-band.

[0138] In

[0011] , it is proposed that the parameter msgl -FrequencyStart is reinterpreted for SBFD UE such that msgl -FrequencyStart is relative to the 1stRB of the UL sub-band instead of the 1stRB of the BWP. That is:

[0139] RBk-uL = msgl -FrequencyStart + RBUL sub-band

[0140] Where,

[0141] • RBk-uL is the reinterpreted msgl -FrequencyStart which reference the UL sub-band

[0142] • RBUL sub-band IS the start of the UL sub-band

[0143] However, changing the reference point for msgl -FrequencyStart may not place ROs within the UL subband, and it may even put the ROs outside of the BWP. An example is shown in Figure 16, where the PRACH Configuration Index used for legacy UE has ROs in DL slots, e.g., Slot n. The msgl- FrequencyStar is configured so that the RO is at the upper edge of the BWP. Using the method proposed in

[0011] to reinterpret the reference point of msgl -FrequencyStart for SBFD slot, that would move the ROs outside of the BWP in the SBFD slot as shown in Slot n of Figure 16.

[0144] In

[0012] and

[0013] , it is proposed that a modulus (MOD) function is used to ensure that ROs which would otherwise fall outside the UL subband are instead within the UL subband, specifically in

[0013] , the start of each FDM RO is determined as:

[0145] RBk = RBuL subband + RBo-k MOD (NuL subband ~ NRO)

[0146] Where,

[0147] • RBk is the reinterpreted start of the id FDM RO with reference to the start of the BWP

[0148] • RBUL subband IS the starting RB of the UL subband

[0149] • RBo-k is the start of the legacy id FDM RO (e.g. as indicated by msgl -FrequencyStart for the lowest / first FDMed RO i.e., k=), and for subsequent RO’s, i.e., L>1, RBo~k = msgl -FrequencyStart + ((L-l) x NRO))

[0150] • NUL subband IS the frequency size of the UL subband in number of RBs

[0151] • NRO is the frequency size of an RO in number of RBs

[0152] An example using the method in

[0013] is shown in Figure 17, which has the same configuration as the example in Figure 16. In this example the ROs in the SBFD Slot n, are contained within the UL sub-band due to the MOD function, and any ROs that falls outside of it, for example RO#2 and RO#4, would be wrapped around within the UL sub-band due to the MOD function.

[0153] It should be noted that the reinterpreted msgl -FrequencyStart can be expressed in the form of RBuv or RBk. That is the reinterpreted msgl -FrequencyStart RBuui . would be relative to a start of UL sub-band (i.e. a lowest frequency of the UL sub-band), whereas another reinterpretation RBk would be relative to a start (lowest frequency) of the BWP, and that any calculation would add R.BUL_subband into it. Both of these definitions are applicable to the present disclosure, such that an RO frequency offset could be considered to be relative to a start of either the UL sub-band or the BWP.

[0154] An issue identified with the RO wrap around method using the MOD function is that it may cause intra PRACH slot RO collisions. This can occur if the RO that is wrapped around collides with a lower frequency FDM RO, which is likely for a small UL sub-band configured with large number of FDM RO and short format preamble at higher SCS, e.g. 12 RB RO at 60 kHz SCS or 120 kHz SCS. An example is shown in Figure 18, where the msgl-FDM= 4 and we assume the UE operates in a higher SCS such as 60 kHz with an RO occupying 12 RBs. Using the method in

[0010] , the first 3 ROs are contained within the UE sub-band in SBFD Slot n, and as per the method, the 4thFDM RO, RO#4 and RO#8 is wrapped around to the beginning of the UL sub-band. However, the wrapped around RO#4 and RO#8 collides with the lower frequency FDM RO, i.e. RO#1 and RO#5.

[0155] Hence, a technical problem is to resolve RO collisions within a PRACH slot due to reinterpretation of msgl- FrequencyStart to contain ROs within the UL sub-band.

[0156] According to the present disclosure, one or more ROs or POs may be invalidated or removed based on the reinterpreted RO / PO frequency offset parameter. That is, an SBFD communications device (e.g. a UE) determines frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band. After determining the RBs, the communications device identifies one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid ROs or POs, comprises invalidating one or more of the plurality of TOs, and then transmits, to the infrastructure equipment, either a PRACH preamble or a PUSCH in a first TO of the one or more valid TOs.

[0157] As one example, a UE, when determining RBs for an RO, may relocate (i.e. wrap-around, as discussed above) an RO to within the UL sub-band of an SBFD slot (or in general of an SBFD OFDM symbol). The UE may then invalidate (i.e. remove) that RO if it collides with another RO. An example is shown in Figure 19, where msgl-FDM= 4, and the reinterpreted ms gl -Frequency Start leads to 4 ROs: RO#1, RO#2, RO#5 and RO#6, being within the UL sub-band, whilst RO#3, RO#4, RO#7 and RO#8 fall outside of the UL subband. In this case, the UE calculates new RBs for the ROs which are outside the UL sub-band (i.e. RO#3, RO#4, RO#7 and RO#8) in order to place these ROs within the UL sub-band. The new RBs may be calculated in a variety of ways, such as those discussed above in relation to Figure 16, 17, and 18. For example, the new RBs may be calculated based on a first frequency offset, which may be regarded as a reinterpretation of a second frequency offset. The first frequency offset may be determined by the UE based on the second frequency offset and RBs of the UL sub-band. In some cases, the first frequency offset is determined based on a modulo result, the modulo result being: a modulo of the second frequency offset and a further parameter, wherein the further parameter is based on a number of RBs forming the UL sub-band. For example, as discussed in

[0013] , the first frequency offset may be determined according to an addition of a lowest frequency TO of the UL sub-band and the modulo result. Moreover, in some cases, as discussed above, the further parameter may be the number of RBs forming the UL sub-band subtracted by a size of a TO in RBs. However, it should be appreciated that other calculations may be used, for example whereby the further parameter is the number of RBs forming the UL sub-band, as will be discussed in more detail later with regard to Figures 21 and 22. Returning to Figure 19, the ROs which are outside the UL sub-band (in this case RO#3, RO#4, RO#7 and RO#8) are relocated within the UL sub-band. RO#3 and RO#7 do not collide (i.e. have overlapping RBs) with any other ROs (in the UL-sub-band) and as such are valid ROs. However, RO#4 and RO#8 collide with RO#1 and RO#5 respectively, as their RBs overlap. Accordingly, due to this collision after RO#4 and RO#8 have been relocated, RO#4 and RO#8 are invalidated (i.e. removed or set as invalid) by the UE. As such, only 6 ROs are present in Slot n, rather than the original 8. In other words, by invalidating one or more ROs, the total number of available ROs is reduced, however all valid ROs are within the UL-sub- band.

[0158] While as discussed above, an RO may be invalidated based on relocating the RO such that it collides with another RO, it should be appreciated that an RO may be invalidated in other ways. For example, based on an RO being outside of the UL sub-band, a UE may calculate candidate (i.e. potential) new RBs for an RO, determine whether these candidate RBs overlap (i.e. collide with) ROs in the UL sub-band. Should the candidate RBs not collide with an existing RO in the UL sub-band, the UE may only then relocate the RO to the candidate RBs. However, if the UE determines that the candidate RBs for the RO would collide with another RO, the UE may then refrain from relocating the RO to the candidate RBs, and may then instead invalidate the RO based on the RO being outside of the UL sub-band. Returning to the illustration in Figure 19, according to this example the UE may calculate candidate RBs for each of RO#3, RO#4, RO#7, and RO#8 within the UL sub-band. The UE may then determine that the candidate RBs for RO#3 and RO#7 do not collide with any other ROs and as such would relocate RO#3 and RO#7 to their respective candidate RBs within the UL sub-band. However, the UE may then determine that candidate RBs for RO#4 and RO#8 collide with RO#1 and RO#5. As such, the UE may refrain from relocating RO#4 and RO#8 to their respective candidate RBs within the UL sub-band, and may instead invalidate RO#4 and RO#8 based on being outside of the UL sub-band.

[0159] In other cases, in the event of a collision between an existing RO and a (potentially) relocated RO, the relocated RO may replace the existing RO (i.e. the existing RO is invalidated). This example is illustrated in Figure 20, which has the same RO configuration as Figure 19, where RO#1, RO#2, RO#5 and RO#6, are within the UL sub-band, whilst RO#3, RO#4, RO#7 and RO#8 fall outside of the UL sub-band. As discussed with relation to Figure 19, RO#3 and RO#7 may be relocated to within the UL sub-band. Regarding RO#4 and RO#8, the UE may determine, either before or after relocating RO#4 and RO#8 to within the UL sub-band, that relocated RO#4 and RO#8 collide with RO#1 and RO#5 respectively. As such, RO#1 and RO#5 may be invalidated (i.e. removed). In this way, RO#4 and RO#8 effectively replace RO#1 and RO#5, as shown by the right-hand side of Figure 20. Relocated RO#4 and RO#8 may utilise a subset of RBs of RO#1 and RO#5 or the exactly same RBs.

[0160] According to certain examples, the infrastructure equipment (e.g. base station or gNB - the infrastructure equipment may generally referred to as gNB for brevity throughout the description), may configure a frequency offset for the ROs (i.e. an RO frequency offset) in a variety of different ways. For example, the gNB may configure an RO frequency offset by msgl-FrequencyStart, as discussed above, msgl- FrequencyStart may, for example, be signaled to the UE by the network (e.g. via the gNB to which the PRACH is transmitted, or a different infrastructure equipment). The msgl -Frequency Start may be signaled in dedicated signaling, or in broadcast signaling, such as a system information broadcast (SIB), such as SIB1. The value of msgl -Frequency Start may be set by the gNB without regard to whether the ROs are within the UL sub-band, as shown in at least Figures 15 and 16, and the UE may then reinterpret the RO frequency offset (i.e. calculate a new RO frequency offset) based on the RBs of the UL sub-band. However, in some cases the gNB may take account of the presence of the UL sub-band when setting the offset (i.e. msgl -FrequencyStart). As such, the RO frequency offset (msgl -FrequencyStart) may be set by the gNB such that the ROs are located within the UL sub-band without the UE needing to reinterpret the RO frequency offset. Utilising the function proposed in

[0013] and discussed above, in such cases where the RO frequency offset is set by the gNB such that ROs are already located within the UL sub-band, would lead to a different frequency location for the ROs due to the subtracting of the RO size NRO in the MOD function, i.e., MOD (NuL subband - NRO). For example, an example system may have a 100 RB BWP, an UL sub-band of NuL subband = 20 RB, an RO size NRO = 6 RB, a starting RB of the UL sub-band, RBUL_subband = 40, i.e., a {DUD} SBFD sub-band configuration. If the network sets msgl -FrequencyStart = 40 so that the ROs are within the UL sub-band, then if the method in

[0013] is used, i.e.:

[0161] RBk = RBuL subband + RBo-k MOD (NuL subband ~ NRO) substituting the above numbers yields: B] = 40 + 40 MOD (20-6) = 52. This is the frequency location of the RO indicated by the legacy parameter msgl -FrequencyStart for UL OFDM symbols, is displaced to a different frequency location in SBFD OFDM symbols, even though msgl -FrequencyStart places the ROs within the frequencies of UL sub-band. In other words, if msgl -FrequencyStart is set such that ROs fall within the UL sub-band of a particular OFDM symbol or slot, then these ROs will not align with ROs in non-SBFD UL OFDM symbols or slots. This is illustrated in Figure 21, wherein the msgl -FrequencyStart is set such that ROs would be within an UL sub-band (as shown in non-SBDF UL Slot n+1), however for the SBFD slot, the RO frequency offset is recalculates using the approach in

[0013] , meaning the ROs in Slot n and Slot n+1 are not frequency aligned (i.e. occupy different ROs). This may be true regardless of whether the msgl -FrequencyStart is set relative to the start of the BWP, or relative to the start of the UL sub-band, as illustrated in Figure 22.

[0162] It may be desirable to the network to have RO frequency locations aligned in all slots, for example for, a {UD} or {DU} SBFD sub-band formats, but the method in

[0013] will cause misalignment in the ROs. As such, if msgl -FrequencyStart is set by the network such that an RO is within the UL sub-band, the UE may utilise the msgl -FrequencyStart signaled by the network as the RO frequency offset, without modification. This may be done, for example, by modifying the calculation in

[0013] as follows:

[0163] RBk = RBUL subband + M.(MOD (NUL_ subband)

[0164] It should be noted, as discussed above, that in general the RO frequency offset may be given relative to a lowest frequency of the BWP (i.e. the RO frequency offset is RBk) or relative to the UL sub-band (i.e. the RO frequency offset is RBk-uL). Therefore, the above equation may also be written as:

[0165] RBk = RBo.kMOD NUL_ subband)

[0166] Accordingly, utilising the above approaches may allow ROs to occupy the same frequencies across SBFD slots and non-SBFD UL slots.

[0167] While the foregoing examples discuss ROs which are outside of an UL sub-band, it should be appreciated that in some examples ROs which are only partially outside the UL sub-band may be considered to be outside of the UL sub-band for the purposes of the present disclosure. For example, as illustrated in Figure 23, ROs (such as RO#2 and RO#4) which are partially outside (and therefore also partially inside) the UL sub-band may be considered to be outside of the UL sub-band. Accordingly, the above discussed examples may be equally applied in cases where one or more ROs are only partially outside of the UL sub-band.

[0168] As discussed above, valid ROs are indexed before performing an SSB-RO mapping. According to the present disclosure, this indexing of ROs may be performed after the RO frequency offset has been recalculated based on the UL sub-band. This is, the UE may first determine the frequency locations (i.e. RBs) for the ROs, as discussed above, which may include relocating ROs which are outside the UL sub- band to be within the UL sub-band. The UE may then identify valid ROs (e.g. which are within the UL subband and do not collide with other ROs). After identifying the valid ROs, the UE may then index the ROs. As an example, the UE may index the ROs by frequency, then time, such that the earliest RO having the lowest frequency is indexed first, followed by ROs at the same time but in sequentially increasing frequency (if present), followed by an RO with lowest frequency at the next time, followed by ROs at the same time but in sequentially increasing frequency, and so on. An example of this process in shown in Figure 24, whereby two ROs are relocated to within the UL sub-band and two ROs outside the UL sub-band are invalidated, such that there are 6 valid ROs within Slot n. The ROs are then assigned RO Indexes 1-6 by indexing the ROs by frequency, then time. This RO indexing may then be used by the UE to perform the SSB-RO mapping. That is, the UE may then select an RO on which to transmit a PRACH based on a measured SSB, as discussed above.

[0169] In some cases, an RO may span both SBFD and non-SBFD UL OFDM symbols. For example, as shown in Figure 25, an RO may span SBFD Slot n and UL Slot n+1. This may be used, e.g. for comparatively large cells. In such examples, the frequency location of the RO may be based on a common RO frequency offset, in this case an RO frequency offset which ensures the RO is located within the UL sub-band of the SBFD OFDM symbols. This ensures that the RO occupies the same frequency resources (i.e. RBs) across both the SBFD and non-SBFD UL OFDM symbols.

[0170] While the foregoing examples all discuss ROs (i.e. PRACH occasions), it should be appreciated that all of the techniques according to the present disclosure are equally applicable to other forms of transmission / uplink occasion. For example, the techniques of this disclosure are equally applicable to the determination of frequency resources (i.e. RBs) for physical uplink shared channel (PUSCH) occasions (POs) for use in transmitting a PUSCH as part of a 2-step RACH procedure. As such, where the foregoing description refers to ROs, this should be interpreted as referring to either an RO or a PO, which may be collectively referred to as a transmission occasion (TO).

[0171] Figure 26 illustrates a flowchart depicting a method 100 of operating a communications device according to the present disclosure. Step SI 10 includes determining frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band. Step S120 includes identifying one ormore valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs. Step S130 includes transmitting, to the infrastructure equipment, either a PRACH preamble or a PUSCH in a first TO of the one or more valid TOs. It should be appreciated that the communication device may transmit a PRACH preamble or a PUSCH in the valid TO immediately (i.e. in a next instance of a particular valid TO), or at a later time after determining the RBs of the TO (i.e. in a subsequent instance of a particular valid TO).

[0172] Figure 27 illustrates a flowchart depicting a method 200 of operating a communications device according to the present disclosure. Step S210 includes determining frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one ormore SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band. Step S220 includes identifying one or more valid TOs of the plurality of TOs. Step S230 includes assigning a TO index to each of the one or more valid TOs.

[0173] Figure 28 illustrates a flowchart depicting a method 300 of operating a communications device according to the present disclosure. Step S310 includes determining frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises setting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols. Step S320 includes identifying the TO as a valid TO.

[0174] Figure 29 illustrates a flowchart depicting a method 400 of operating an infrastructure equipment according to the present disclosure. Step S410 includes transmitting, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs). Step S420 includes receiving, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein the particular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL sub-band.

[0175] Those skilled in the art would further appreciate that methods, infrastructure equipment and / or communications devices as herein defined may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. It would be further appreciated by those skilled in the art that such infrastructure equipment and communications devices as herein defined and described may form part of communications systems other than those defined by the present disclosure, provided that these are within the scope of the claims.

[0176] The methods described herein may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions. Instructions embedded or encoded in a computer-readable medium may cause a programmable processor, or other processor, to perform the method, e.g., when the instructions are executed. Computer-readable media may include non-transitory computer-readable storage media and transient communication media. Computer readable storage media, which is tangible and non-transitory, may include random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a CD- ROM, a floppy disk, a cassette, magnetic media, optical media, or other computer-readable storage media. The term “computer-readable storage media” refers to physical storage media, and not signals, carrier waves, or other transient media. As noted above, computer readable media may include transient communication media. Such communication media may occur within a single computer system or between multiple computer systems, and may take the form of transient signal-conveying media such as carrier waves and transmission signals.

[0177] Accordingly, from one perspective there has been described methods, communications devices, and infrastructure equipment are provided for validation of PRACH occasions or PUSCH occasions (TOs). In particular, when resource blocks for a TO are determined (which may include relocating a TO within an SBFD UL sub-band), TOs which are outside of the UL sub-band or that collide with another TO are invalidated. A PRACH preamble or PUSCH may then be received on one of the valid TOs. This applies in examples where the RBs for a TO may be determined based on a particular frequency offset, which is determined based on another frequency offset and the RBs of the UL sub-band.

[0178] Particular examples of the present disclosure are set forth in the following numbered clauses: 1 . A method of operating a communications device configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex (SBFD) capable communications device, the method comprising: determining frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identifying one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs.

[0179] 2. The method according to clause 1, further comprising transmitting, to the infrastructure equipment, either a PRACH preamble or a PUSCH in a first TO of the one or more valid TOs.

[0180] 3. The method according to clause 1 or clause 2, wherein the plurality of TOs are a plurality of ROs, and wherein the PRACH preamble is transmitted in a first RO of one or more valid ROs.

[0181] 4. The method according to clause 1 or clause 2, wherein the plurality of TOs are a plurality of POs, and wherein the PUSCH is transmitted in a first PO of one or more valid POs.

[0182] 5. The method according to any preceding clause, wherein determining the RBs comprises: based on determining that a particular TO is outside of the UL sub-band, relocating the particular TO within the UL sub-band.

[0183] 6. The method according to clause 5, wherein identifying the one or more valid TOs comprises: based on determining that the relocated particular TO has one or more RBs which at least partially overlaps with an existing TO within the UL sub-band, invalidating the particular TO.

[0184] 7. The method according to clause 5, wherein identifying the one or more valid TOs comprises: based on determining that the relocated particular TO at least partially overlaps in RBs with an existing TOs within the UL sub-band, invalidating the existing TO.

[0185] 8. The method according to any of clauses 1-4, wherein determining the RBs comprises: based on determining that a particular TO is outside of the UL sub-band, calculate candidate RBs for the TO within the UL sub-band; and based on determining that the candidate RBs would collide with an existing TO within the UL subband, refraining from relocating the particular TO to the candidate RBs; wherein identifying the one or more valid TOs comprises invalidating the particular TO based on the particular TO being outside of the UL sub-band.

[0186] 9. The method according to any of clauses 3-8, wherein determining that the particular TO is outside of the UL sub-band comprises determining that the particular TO is at least partially outside of the UL subband.

[0187] 10. The method according to any preceding clause, further comprising: receiving, from the infrastructure equipment, and indication of the second TO frequency offset.

[0188] 11. The method according to any preceding clause, wherein the first TO frequency offset is relative to a lowest frequency RB of a bandwidth part (BWP) of the radio access interface, or a lowest frequency RB of the UL sub-band of the BWP.

[0189] 12. The method according to any preceding clause, wherein the second TO frequency offset is relative to a lowest frequency RB of the BWP, or a lowest frequency RB of the UL sub-band of the BWP.

[0190] 13. The method according to any preceding clause, wherein the first TO frequency offset is determined based on a modulo result, the modulo result being: a modulo of the second TO frequency offset and a further parameter, wherein the further parameter is based on a number of RBs forming the UL sub-band.

[0191] 14. The method according to clause 13, wherein the first TO frequency offset is determined according to an addition of a lowest frequency TO of the UL sub-band and the modulo result.

[0192] 15. The method according to clause 13 or 14, wherein the further parameter is the number of RBs forming the UL sub-band subtracted by a size of a TO in RBs.

[0193] 16. The method according to clause 13 or 14, wherein the further parameter is the number of RBs forming the UL sub-band.

[0194] 17. The method according to any preceding clause, wherein if the second TO frequency offset is within the UL sub-band, the first TO frequency offset is determined to be the second TO frequency offset.

[0195] 18. The method according to any preceding clause, further comprising: assigning a TO index to each of the one or more valid TOs; wherein transmitting the PRACH preamble or PUSCH in the first TO is based on an assigned index of the first TO.

[0196] 19. The method according to any preceding clause, wherein the plurality of TOs comprise: one or more SBFD TOs contained within SBFD OFDM symbols of the radio access interface and one or more non- SBFD TOs contained within non-SBFD UL OFDM symbols of the radio access interface.

[0197] 20. A communications device, the communications device being a sub-band full duplex, SBFD, capable communications device and comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs.

[0198] 21. Circuitry for a communications device, the communications device being a sub-band full duplex, SBFD, capable communications device, the circuitry comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs.

[0199] 22. A method of operating a communications device configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex (SBFD) capable communications device, the method comprising: determining frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identifying one or more valid TOs of the plurality of TOs; and assigning a TO index to each of the one or more valid TOs.

[0200] 23. The method according to clause 22, further comprising: transmitting, to the infrastructure equipment, either: a PRACH preamble or a PUSCH in a first TO of the one or more valid TOs.

[0201] 24. A communications device, the communications device being a sub-band full duplex, SBFD, capable communications device and comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs; and assign a TO index to each of the one or more valid TOs.

[0202] 25. Circuitry for a communications device, the communications device being a sub-band full duplex, SBFD, capable communications device, the circuitry comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs; and assign a TO index to each of the one or more valid TOs.

[0203] 26. A method of operating a communications device configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex (SBFD) capable communications device, the method comprising: determining frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) subband and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises setting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols; and identifying the TO as a valid TO.

[0204] 27. The method according to clause 26, further comprising: transmiting, to the infrastructure equipment, either: a PRACH preamble or a PUSCH in the TO.

[0205] 28. A communications device, the communications device being a sub-band full duplex, SBFD, capable communications device and comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises seting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols; and identify the TO as a valid TO.

[0206] 29. Circuitry for a communications device, the communications device being a sub-band full duplex, SBFD, capable communications device, the circuitry comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises seting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols; and identify the TO as a valid TO.

[0207] 30. A method of operating an infrastructure equipment forming part of a wireless communications network and configured to transmit signals to and / or to receive signals from a communications device via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex, SBFD, capable communications device, the method comprising: transmitting, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs); and receiving, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein the particular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL sub-band.

[0208] 31. The method according to clause 30, wherein the plurality of TOs are a plurality of ROs, and wherein the PRACH preamble is received in a first RO of one or more valid TOs.

[0209] 32. The method according to clause 30, wherein the plurality of TOs are a plurality of POs, and wherein the PUSCH is received in a first PO of one or more valid POs.

[0210] 33. The method according to any of clauses 30-32, wherein the second frequency offset is relative to a lowest frequency RB of a bandwidth part (BWP) of the radio access interface, or a lowest frequency RB of the UL sub-band of the BWP.

[0211] 34. The method according to any of clauses 30-33, wherein the first frequency offset is relative to a lowest frequency RB of a bandwidth part (BWP) of the radio access interface, or a lowest frequency RB of the UL sub-band of the BWP.

[0212] 35. The method according to any of clauses 30-34, wherein the second frequency offset is based on a modulo result, the modulo result being: a modulo of the first frequency offset and a further parameter, wherein the further parameter is based on a number of RBs forming the UL sub-band.

[0213] 36. The method according to clause 35, wherein the second frequency offset is an addition of a lowest frequency TO of the UL sub-band and the modulo result.

[0214] 37. The method according to clause 35 or 36, wherein the further parameter is the number of RBs forming the UL sub-band subtracted by a size of a TO in RBs.

[0215] 38. The method according to clause 35 or 36, wherein the further parameter is the number of RBs forming the UL sub-band.

[0216] 39. The method according to any of clauses 30-38, wherein the first frequency offset is within the UL sub-band, and wherein the second frequency offset is the same as the second frequency offset.

[0217] 40. The method according to any of clauses 30-39, wherein the plurality of TOs comprise: one or more SBFD TOs contained within SBFD OFDM symbols of the radio access interface and one or more non- SBFD TOs contained within non-SBFD UL OFDM symbols of the radio access interface.

[0218] 41. The method according to any of clauses 30-40, wherein the TO occupies one or more SBFD OFDM symbols and one or more non-SBFD UL OFDM symbols, and wherein the TO occupies the same resource blocks in both the SBFD and non-SBFD UL OFDM symbols.

[0219] 42. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex, SBFD, capable communications device, and controller circuitry configured in combination with the transceiver circuitry to: transmit, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequencydivision multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other subbands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs); and receive, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein the particular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL subband.

[0220] 43. Circuitry for an infrastructure equipment forming part of a wireless communications network, the circuitry comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex, SBFD, capable communications device, and controller circuitry configured in combination with the transceiver circuitry to: transmit, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequencydivision multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other subbands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs); and receive, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein the particular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL subband.

[0221] 44. A wireless communications system comprising a communications device according to clause 20 and / or clause 24 and / or clause 28, and an infrastructure equipment according to clause 42.

[0222] 45. A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any of clauses 1, 22, 26, and 30.

[0223] It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and / or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and / or processors may be used without detracting from the embodiments.

[0224] Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and / or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and / or processors.

[0225] Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in any manner suitable to implement the technique.

[0226] References

[0227] [1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009.

[0228] [2] TR 38.913, “3rdGeneration Partnership Project; Technical Specification Group Radio Access Network; Study on Scenarios and Requirements for Next Generation Access Technologies (Release 14)”, 3GPP, V14.3.0, August 2017.

[0229] [3] RP -213591, “New SI: Study on evolution of NR duplex operation,” CMCC, RAN#94e, December

[0230] 2021.

[0231] [4] RP -220633, “Revised SID: Study on evolution of NR duplex operation,” CMCC, RAN#95e, March

[0232] 2022.

[0233] [5] RP-234035, “New WID: Evolution of NR duplex operation: Sub-band full duplex (SBFD),” CMCC, RAN# 102, December 2023.

[0234] [6] European Patent No. 3545716.

[0235] [7] TS 38.211 “Physical channels and modulation (Rel-18),” 3GPP, vl8.0.0, September 2023.

[0236] [8] TS 38.213, “Physical layer procedures for control (Rel-18),” 3GPP, vl8.0.0, September 2023.

[0237] [9] European patent application number EP24155834.5.

[0238]

[0010] Rl- 2404616, “Discussion on SBFD random access operation,” Xiaomi, RAN1#117

[0239]

[0011] Rl-2404008, “Discussion on SBFD random access operation,” ZTE, RAN1#117

[0240]

[0012] Rl -2404318, “Random access in SBFD symbols,” Sharp

[0241]

[0013] Rl-2403912, “SBFD random access operation,” Ericsson

Claims

CLAIMS1. A method of operating a communications device configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex (SBFD) capable communications device, the method comprising: determining frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identifying one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs.

2. The method according to claim 1, further comprising transmitting, to the infrastructure equipment, either a PRACH preamble or a PUSCH in a first TO of the one or more valid TOs.

3. The method according to claim 1, wherein the plurality of TOs are a plurality of ROs, and wherein the PRACH preamble is transmitted in a first RO of one or more valid ROs.

4. The method according to claim 1, wherein the plurality of TOs are a plurality of POs, and wherein the PUSCH is transmitted in a first PO of one or more valid POs.

5. The method according to claim 1, wherein determining the RBs comprises: based on determining that a particular TO is outside of the UL sub-band, relocating the particular TO within the UL sub-band.

6. The method according to claim 5, wherein identifying the one or more valid TOs comprises: based on determining that the relocated particular TO has one or more RBs which at least partially overlaps with an existing TO within the UL sub-band, invalidating the particular TO.

7. The method according to claim 5, wherein identifying the one or more valid TOs comprises: based on determining that the relocated particular TO at least partially overlaps in RBs with an existing TOs within the UL sub-band, invalidating the existing TO.

8. The method according to claim 1, wherein determining the RBs comprises:based on determining that a particular TO is outside of the UL sub-band, calculate candidate RBs for the TO within the UL sub-band; and based on determining that the candidate RBs would collide with an existing TO within the UL subband, refraining from relocating the particular TO to the candidate RBs; wherein identifying the one or more valid TOs comprises invalidating the particular TO based on the particular TO being outside of the UL sub-band.

9. The method according to claim 3, wherein determining that the particular TO is outside of the UL sub-band comprises determining that the particular TO is at least partially outside of the UL sub-band.

10. The method according to claim 1, further comprising: receiving, from the infrastructure equipment, and indication of the second TO frequency offset.

11. The method according to claim 1, wherein the first TO frequency offset is relative to a lowest frequency RB of a bandwidth part (BWP) of the radio access interface, or a lowest frequency RB of the UL sub-band of the BWP.

12. The method according to claim 1, wherein the second TO frequency offset is relative to a lowest frequency RB of the BWP, or a lowest frequency RB of the UL sub-band of the BWP.

13. The method according to claim 1, wherein the first TO frequency offset is determined based on a modulo result, the modulo result being: a modulo of the second TO frequency offset and a further parameter, wherein the further parameter is based on a number of RBs forming the UL sub-band.

14. The method according to claim 13, wherein the first TO frequency offset is determined according to an addition of a lowest frequency TO of the UL sub-band and the modulo result.

15. The method according to claim 13, wherein the further parameter is the number of RBs forming the UL sub-band subtracted by a size of a TO in RBs.

16. The method according to claim 13, wherein the further parameter is the number of RBs forming the UL sub-band.

17. The method according to claim 1, wherein if the second TO frequency offset is within the UL subband, the first TO frequency offset is determined to be the second TO frequency offset.

18. The method according to claim 1, further comprising: assigning a TO index to each of the one or more valid TOs; wherein transmitting the PRACH preamble or PUSCH in the first TO is based on an assigned index of the first TO.

19. The method according to claim 1, wherein the plurality of TOs comprise: one or more SBFD TOs contained within SBFD OFDM symbols of the radio access interface and one or more non-SBFD TOs contained within non-SBFD UL OFDM symbols of the radio access interface.

20. A communications device, the communications device being a sub-band full duplex, SBFD, capable communications device and comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs.

21. Circuitry for a communications device, the communications device being a sub-band full duplex, SBFD, capable communications device, the circuitry comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs, wherein identifying the one or more valid TOs comprises invalidating one or more of the plurality of TOs.

22. A method of operating a communications device configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex (SBFD) capable communications device, the method comprising: determining frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identifying one or more valid TOs of the plurality of TOs; and assigning a TO index to each of the one or more valid TOs.

23. The method according to claim 22, further comprising: transmitting, to the infrastructure equipment, either: a PRACH preamble or a PUSCH in a first TO of the one or more valid TOs.

24. A communications device, the communications device being a sub-band full duplex, SBFD, capable communications device and comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs; and assign a TO index to each of the one or more valid TOs.

25. Circuitry for a communications device, the communications device being a sub-band full duplex, SBFD, capable communications device, the circuitry comprising:transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for each of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the transmission occasions comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs), wherein determining the RBs is based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band; and identify one or more valid TOs of the plurality of TOs; and assign a TO index to each of the one or more valid TOs.

26. A method of operating a communications device configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex (SBFD) capable communications device, the method comprising: determining frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) subband and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises setting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols; and identifying the TO as a valid TO.

27. The method according to claim 26, further comprising: transmitting, to the infrastructure equipment, either: a PRACH preamble or a PUSCH in the TO.

28. A communications device, the communications device being a sub-band full duplex, SBFD, capable communications device and comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, andcontroller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises setting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols; and identify the TO as a valid TO.

29. Circuitry for a communications device, the communications device being a sub-band full duplex, SBFD, capable communications device, the circuitry comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from an infrastructure equipment of a wireless communications network via a radio access interface between the communications device and the infrastructure equipment, and controller circuitry configured in combination with the transceiver circuitry to: determine frequency resource blocks (RBs) for a transmission occasion (TO) traversing: one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, and one or more non-SBDF UL OFDM symbols, the TO being either a physical random access channel (PRACH) occasion (RO) or a physical uplink shared channel (PUSCH) occasions (PO), wherein determining the RBs comprises determining the RBs for the one or more SBFD OFDM symbols based on determining a first TO frequency offset, wherein the first TO frequency offset is determined based on a second TO frequency offset and RBs of the UL sub-band of the one or more SBFD OFDM symbols, and wherein the determining the RBs comprises setting the RBs for the non-SBDF UL OFDM symbols to be the same as the RBs for the one or more SBFD OFDM symbols; and identify the TO as a valid TO.

30. A method of operating an infrastructure equipment forming part of a wireless communications network and configured to transmit signals to and / or to receive signals from a communications device via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex, SBFD, capable communications device, the method comprising: transmitting, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonalfrequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs); and receiving, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein the particular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL sub-band.

31. The method according to claim 30, wherein the plurality of TOs are a plurality of ROs, and wherein the PRACH preamble is received in a first RO of one or more valid TOs.

32. The method according to claim 30, wherein the plurality of TOs are a plurality of POs, and wherein the PUSCH is received in a first PO of one or more valid POs.

33. The method according to claim 30, wherein the second frequency offset is relative to a lowest frequency RB of a bandwidth part (BWP) of the radio access interface, or a lowest frequency RB of the UL sub-band of the BWP.

34. The method according to claim 30, wherein the first frequency offset is relative to a lowest frequency RB of a bandwidth part (BWP) of the radio access interface, or a lowest frequency RB of the UL sub-band of the BWP.

35. The method according to claim 30, wherein the second frequency offset is based on a modulo result, the modulo result being: a modulo of the first frequency offset and a further parameter, wherein the further parameter is based on a number of RBs forming the UL sub-band.

36. The method according to claim 35, wherein the second frequency offset is an addition of a lowest frequency TO of the UL sub-band and the modulo result.

37. The method according to claim 35, wherein the further parameter is the number of RBs forming the UL sub-band subtracted by a size of a TO in RBs.

38. The method according to claim 35, wherein the further parameter is the number of RBs forming the UL sub-band.

39. The method according to claim 30, wherein the first frequency offset is within the UL sub-band, and wherein the second frequency offset is the same as the second frequency offset.

40. The method according to claim 30, wherein the plurality of TOs comprise: one or more SBFD TOs contained within SBFD OFDM symbols of the radio access interface and one or more non-SBFD TOs contained within non-SBFD UL OFDM symbols of the radio access interface.

41. The method according to claim 30, wherein the TO occupies one or more SBFD OFDM symbols and one or more non-SBFD UL OFDM symbols, and wherein the TO occupies the same resource blocks in both the SBFD and non-SBFD UL OFDM symbols.

42. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising: transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex, SBFD, capable communications device, and controller circuitry configured in combination with the transceiver circuitry to: transmit, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs); and receive, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein the particular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL sub-band.

43. Circuitry for an infrastructure equipment forming part of a wireless communications network, the circuitry comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a radio access interface between the communications device and the infrastructure equipment, the communications device being a sub-band full duplex, SBFD, capable communications device, and controller circuitry configured in combination with the transceiver circuitry to: transmit, for receipt by the communications device, an indication of a first frequency offset for resource blocks (RBs) of a plurality of transmission occasions (TOs) in one or more SBFD orthogonal frequency-division multiplexing (OFDM) symbols comprising an uplink (UL) sub-band and one or more other sub-bands, the TOs comprising physical random access channel (PRACH) occasions (ROs) or physical uplink shared channel (PUSCH) occasions (POs); and receive, from the communications device and in a particular TO of the plurality of TOs, either a PRACH preamble or a PUSCH in a particular TO of the plurality of TOs, wherein theparticular TO occupies RBs according to a second frequency offset which is based on the first frequency offset and RBs of the UL sub-band.

44. A wireless communications system comprising a communications device according to claim 20 and / or claim 24 and / or claim 28, and an infrastructure equipment according to claim 42.

45. A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any of claims 1, 22, 26, and 30.

Images