Patent Publication Number: US-2023142814-A1

Title: Communications device, infrastructure equipment and methods

Description:
BACKGROUND 
     Field 
     The present disclosure relates to communications devices, infrastructure equipment and methods for transmitting and receiving data in a wireless communications network. 
     The present application claims the Paris Convention priority from European patent application number EP20158107.1, the contents of which are hereby incorporated by reference in their entirety. 
     Description of Related Art 
     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 nor impliedly admitted as prior art against the present invention. 
     Third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support more sophisticated 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, may be expected to increase ever more rapidly. 
     Future wireless communications networks will be expected to support communications routinely and efficiently with a wider range of devices associated with a wider range of data traffic profiles and types than current 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 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. 
     In view of this there is expected to be a desire for future wireless communications networks, for example those which may be referred to as 5G or new radio (NR) system/new radio access technology (RAT) systems [1], 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. 
     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) and Ultra Reliable &amp; Low Latency Communications (URLLC) services have a target for reliability of 1-10 −5  (99.999%) or higher for one transmission of a 32 byte packet with a user plane latency of 1 ms [2]. 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. 
     Additionally, a Reduced Capability User Equipment (RC-UE) may be expected to have a complexity and cost that is between an eMTC/NB-IoT and a URLLC/eMBB user equipment (UE). Examples of RC-UE devices include industrial wireless sensors, video surveillance cameras and wearables [3]. Complexity may be reduced in an RC-UE by reducing the number of RX/TX antennas associated with the RC-UE, reducing the bandwidth associated with the RC-UE, relaxing the processing time of the RC-UE, relaxing the processing time of the RC-UE, and/or implementing a Half-Duplex-Frequency-Division Duplexing (HD-FDD) mode of operation. An HD-FDD device does not require a duplex filter and therefore has a reduced hardware complexity. 
     SUMMARY 
     The present disclosure can help address or mitigate at least some of the issues discussed above. 
     Embodiments of the present technique can provide a method of transmitting and receiving data by a communications device operating according to a Half Duplex Frequency Division Duplex mode of operation (HD-FDD) in a wireless communications network. The method comprising receiving from the wireless communications network a first allocation of first physical resources of an uplink channel of a wireless access interface provided by the wireless communications network for transmitting uplink data to the wireless communications network, and receiving from the wireless communications network a second allocation of second physical resources of a downlink channel of the wireless access interface for receiving downlink data from the wireless communications network. The method includes determining that one or more of the first physical resources of the uplink channel and the second communication resources of the downlink channel overlap in time, and determining, on a basis of a first format indicator for the uplink channel and a second format indicator for the downlink channel, a use of each of the one or more first physical resources and the one or more second physical resources which overlap in time. The first format indicator defines a format for each of the physical resources of the uplink channel, and the second format indicator defines a format for each of the physical resources of the downlink channel. Accordingly if an allocation of uplink and downlink resources overlaps in time, the communications device can resolve a conflict between the overlapping resources, which it cannot use at the same time as a result of being configured to operate in an HD-FDD mode. 
     According to some examples the determined use of each of the one or more first physical resources and the one or more second physical resources which overlap in time can include selecting, on a basis of the first format indicator for the uplink channel and the second format indicator for the downlink channel either to transmit on the one or more of the first physical resources of the uplink channel which overlap with the one or more second physical resources of the downlink channel, or to receive on the one or more of the second physical resources of the downlink channel which overlap the one or more of the first physical resources of the uplink channel. The first format indicator defines a format for each of the physical resources of the uplink channel, and the second format indicator defines a format for each of the physical resources of the downlink channel. For example the format indicators could designate each physical resource as uplink, downlink or flexible. In one example the format indicators are slot format indicators (SFI), which are examples of indicators. The selecting on the basis of the first format indicator and the second format indicator comprises combining for each of the one of more first physical resources of the uplink channel and the one or more second physical resources of the downlink channel which overlap in time, the defined format from the first format indicator and the second format indicator, and determining a use of each of the physical resources which overlap according to a predetermined rule. The combining can form a dual SFI which can be applied to a lookup table to determine how the physical resources in conflict can be used. 
     In some examples the first format indicator for an uplink channel and the second format indicator for the downlink channel may be received from the wireless communications network. 
     The present inventors have recognised that implementing an HD-FDD mode of operation in an RC-UE may lead to contention problems between uplink transmission and downlink reception between the RC-UE and a network particularly when the RC-UE is configured with an NR service which requires low latency such as URLLC. The implementation of the HD-FDD mode of operation in order to reduce the complexity of a UE configured with low latency NR services therefore represents a technical challenge. 
     Respective aspects and features of the present disclosure are defined in the appended claims. 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG.  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; 
         FIG.  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; 
         FIG.  3    is a schematic block diagram of an example infrastructure equipment and communications device which may be configured in accordance with example embodiments; 
         FIG.  4    illustrates full duplex communications in accordance with conventional techniques; 
         FIG.  5    illustrates half duplex communications in accordance with conventional techniques, which may be adapted in accordance with embodiments of the present disclosure; 
         FIG.  6    shows an illustrative example of communication resources used by a half-duplex frequency division duplex (HD-FDD) device; 
         FIG.  7    shows an illustrative example of an intra-user equipment (UE) FDD collision between an uplink and a downlink transmission which may occur in an HD-FDD device; 
         FIG.  8    is an illustrative example of communication resources of a frequency band which may be configured to transmit uplink data or receive downlink data according to an example embodiment; 
         FIG.  9    is an illustrative example of a format of communication resources of a first band of frequencies configured for transmitting uplink data and a format of communication resources of a second band of frequencies configured for receiving downlink data over one time slot according to an example embodiment; 
         FIG.  10    is an illustrative example of a format of communication resources of a first band of frequencies configured for transmitting uplink data and a format of communication resources of a second band of frequencies configured for receiving downlink data over three time slots according to an example embodiment; 
         FIG.  11    is an illustrative example of first communications resources and second communication resources completely overlapping in time according to an example embodiment; 
         FIG.  12    is an illustrative example of first communication resources and second communication resources partly overlapping in time according to an example embodiment; and 
         FIG.  13    is a flow diagram providing an example illustration of an operation of a communications device according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Long Term Evolution Advanced Radio Access Technology (4G) 
       FIG.  1    provides a schematic diagram illustrating some basic functionality of a mobile telecommunications network/system  100  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  FIG.  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 [4]. 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. 
     The network  100  includes a plurality of base stations  101  connected to a core network part  102 . Each base station provides a coverage area  103  (e.g. a cell) within which data can be communicated to and from communications devices  104 . Data is transmitted from the base stations  101  to the communications devices  104  within their respective coverage areas  103  via a radio downlink Data is transmitted from the communications devices  104  to the base stations  101  via a radio uplink The core network part  102  routes data to and from the communications devices  104  via the respective base stations  101  and provides functions such as authentication, mobility management, charging and so on. Communications devices may also be referred to as mobile stations, user equipment (UE), user terminals, mobile radios, terminal devices, and so forth. Base stations, which are an example of network infrastructure equipment/network access nodes, may also be referred to as transceiver stations/nodeBs/e-nodeBs, 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, example embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems such as 5G or new radio as explained below, 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. 
     New Radio Access Technology (5G) 
       FIG.  2    is a schematic diagram illustrating a network architecture for a new RAT wireless communications network/system  200  based on previously proposed approaches which may also be adapted to provide functionality in accordance with embodiments of the disclosure described herein. The new RAT network  200  represented in  FIG.  2    comprises a first communication cell  201  and a second communication cell  202 . Each communication cell  201 ,  202 , comprises a controlling node (centralised unit)  221 ,  222  in communication with a core network component  210  over a respective wired or wireless link  251 ,  252 . The respective controlling nodes  221 ,  222  are also each in communication with a plurality of distributed units (radio access nodes/remote transmission and reception points (TRPs))  211 ,  212  in their respective cells. Again, these communications may be over respective wired or wireless links. The distributed units  211 ,  212  are responsible for providing the radio access interface for communications devices connected to the network. Each distributed unit  211 ,  212  has a coverage area (radio access footprint)  241 ,  242  where the sum of the coverage areas of the distributed units under the control of a controlling node together define the coverage of the respective communication cells  201 ,  202 . Each distributed unit  211 ,  212  includes transceiver circuitry for transmission and reception of wireless signals and processor circuitry configured to control the respective distributed units  211 ,  212 . 
     In terms of broad top-level functionality, the core network component  210  of the new RAT communications network represented in  FIG.  2    may be broadly considered to correspond with the core network  102  represented in  FIG.  1   , and the respective controlling nodes  221 ,  222  and their associated distributed units/TRPs  211 ,  212  may be broadly considered to provide functionality corresponding to the base stations  101  of  FIG.  1   . The term network infrastructure equipment/access node may be used to encompass these elements and more conventional base station type elements of wireless communications 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/centralised unit and/or the distributed units/TRPs. 
     A communications device or UE  260  is represented in  FIG.  2    within the coverage area of the first communication cell  201 . This communications device  260  may thus exchange signalling with the first controlling node  221  in the first communication cell via one of the distributed units  211  associated with the first communication cell  201 . In some cases communications for a given communications device are routed through only one of the distributed units, but it will be appreciated that in some other implementations communications associated with a given communications device may be routed through more than one distributed unit, for example in a soft handover scenario and other scenarios. 
     In the example of  FIG.  2   , two communication cells  201 ,  202  and one communications device  260  are shown for simplicity, but it will of course be appreciated that in practice the system may comprise a larger number of communication cells (each supported by a respective controlling node and plurality of distributed units) serving a larger number of communications devices. 
     It will further be appreciated that  FIG.  2    represents merely one example of a proposed architecture for a new RAT communications 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 communications systems having different architectures. 
     Thus example 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  FIGS.  1  and  2   . It will thus be appreciated that the specific wireless communications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, example 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  101  as shown in  FIG.  1    which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment/access node may comprise a control unit/controlling node  221 ,  222  and/or a TRP  211 ,  212  of the kind shown in  FIG.  2    which is adapted to provide functionality in accordance with the principles described herein. 
     A more detailed illustration of a UE/communications device  270  (which may correspond to a communications device such as the communications device  260  of  FIG.  2    or the communications device  104  of  FIG.  1   ) and an example network infrastructure equipment  272 , which may be thought of as a gNB  101  or a combination of a controlling node  221  and TRP  211 , is presented in  FIG.  3   . As shown in  FIG.  3   , the UE  270  is shown to transmit uplink data to the infrastructure equipment  272  via uplink resources of a wireless access interface as illustrated generally by an arrow  274  from the UE  270  o the infrastructure equipment  272 . The UE  270  may similarly be configured to receive downlink data transmitted by the infrastructure equipment  272  via downlink resources as indicated by an arrow  288  from the infrastructure equipment  272  to the UE  270 . As with  FIGS.  1  and  2   , the infrastructure equipment  272  is connected to a core network  276  via an interface  278  to a controller  280  of the infrastructure equipment  272 . The infrastructure equipment  272  includes a receiver  282  connected to an antenna  284  and a transmitter  286  connected to the antenna  284 . Correspondingly, the UE  270  includes a controller  290  connected to a receiver  292  which receives signals from an antenna  294  and a transmitter  296  also connected to the antenna  294 . 
     The controller  280  is configured to control the infrastructure equipment  272  and may comprise processor circuitry which may in turn comprise various sub-units/sub-circuits for providing functionality as explained further herein. These sub-units may be implemented as discrete hardware elements or as appropriately configured functions of the processor circuitry. Thus the controller  280  may comprise circuitry which is suitably configured/programmed to provide the desired functionality using conventional programming/configuration techniques for equipment in wireless telecommunications systems. The transmitter  286  and the receiver  282  may comprise signal processing and radio frequency filters, amplifiers and circuitry in accordance with conventional arrangements. The transmitter  286 , the receiver  282  and the controller  280  are schematically shown in  FIG.  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  272  will in general comprise various other elements associated with its operating functionality. 
     Correspondingly, the controller  290  of the UE  270  is configured to control the transmitter  296  and the receiver  292  and may comprise processor circuitry which may in turn comprise various sub-units/sub-circuits for providing functionality as explained further herein. These sub-units may be implemented as discrete hardware elements or as appropriately configured functions of the processor circuitry. Thus the controller  290  may comprise circuitry which is suitably configured/programmed to provide the desired functionality using conventional programming/configuration techniques for equipment in wireless telecommunications systems. Likewise, the transmitter  296  and the receiver  292  may comprise signal processing and radio frequency filters, amplifiers and circuitry in accordance with conventional arrangements. The transmitter  296 , receiver  292  and controller  290  are schematically shown in  FIG.  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 communications device  270  will in general comprise various other elements associated with its operating functionality, for example a power source, user interface, and so forth, but these are not shown in  FIG.  3    in the interests of simplicity. 
     The controllers  280 ,  290  may be 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. 
     Frequency Division Duplexing 
     Duplex communications refers to the ability of a device to both transmit and receive data. For example, a communications device (such as the communications device  270  of  FIG.  3   ) may communicate in a duplex manner with the infrastructure equipment  270  by transmitting signals  288  to the infrastructure equipment  272  and by receiving signals  274 , transmitted by the infrastructure equipment  272 . Duplex communications can either be full duplex (FD) or half-duplex (HD).  FIG.  4    shows a system  400  comprising a communications device  401 , configured with a transmitter  401   a,  a receiver  401   b  and a controller  401   c,  communicating in a full duplex manner with a gNB  402  configured with a transmitter  402   a,  a receiver  402   b  and a controller  402   c.  The transmission of data from the communications device  401  to the gNB  402  is represented by an arrow  410  from the communications device  401  to the gNB  402 . The reception of data by the communications device  401  from the gNB  402  is represented by the arrow  411  from the gNB  402  to the communications device  401 . As illustrated in  FIG.  4   , the communications device  401  can both transmit  410  and receive  411  data to/from the gNB  402  simultaneously. 
     By contrast,  FIG.  5    illustrates half duplex communications.  FIG.  5    shows a system comprising a communications device  501  configured with a transmitter  501   a,  a receiver  501   b  and a controller  501   c  communicating with a gNB  502  configured with a transmitter  502   a,  a receiver  502   b  and a controller  502   c.  The transmission of data from the communications device  501  to the gNB  502  is represented by an arrow  510  from the communications device  501  to the gNB  502 . The reception of data by the communications device  501  from the gNB  502  is represented by an arrow  511  from the gNB  502  to the communications device  501 . As illustrated in  FIG.  5   , the communications device  501  cannot transmit  510  and receive  511  data simultaneously. In this case, data cannot be transmitted from the gNB  502  to the communications device  501  until the transmission of data from the communications device  501  to the gNB  502  has stopped. 
     Frequency Division Duplexing (FDD) is a known technique to allow duplex communication, whereby a transmitter and receiver within a device operate at different carrier frequencies. Accordingly, a transmitter of a communications device, for example, may transmit at one frequency while a receiver of the communications device receives at a different frequency. The transmission and reception frequencies are separated by a frequency offset. In other words, for the FDD, a downlink and an uplink communication are operated in different frequency bands/carriers (referred to as paired frequency carriers). It will be appreciated by a person skilled in the art that references to the phrases “a frequency band” or “band of frequencies” disclosed herein may be replaced by the phrase “carrier”. For example, a first band of frequencies may refer to an uplink carrier whereas a second band of frequencies may refer to a downlink carrier. Furthermore, Time Division Duplexing (TDD) is a known technique whereby the transmitter and receiver of a device operate at the same carrier frequency but the transmission and reception of signals are separated in time. In other words, for TDD, a downlink and an uplink communication are operated in the same frequency band/carrier (referred to as unpaired frequency carriers). 
     In accordance with some embodiments described herein, a communications device which is capable of half duplex communications and which is not capable of full-duplex communications, such as the communications device  501  in  FIG.  5   , may be expected to communicate according to an FDD mode of operation. Such a communications device may be referred to as a Half-Duplex-Frequency-Division-Duplexing (HD-FDD) device. 
       FIG.  6    shows an illustrative example of communication resources used by an HD-FDD device. In particular,  FIG.  6    shows a representation of communication resources in a frequency domain  601  and a time domain  602 . During a transmission period  610  a transmitter, such as the transmitter  501   a  of the communications device  501  in  FIG.  5   , can transmit data in a first band of frequencies  631  (in other words, a first carrier) to an infrastructure equipment, such as the gNB  502  in  FIG.  5   . During a reception period  611  a receiver, such as the receiver  501   b  of the communications device  501  in  FIG.  5   , can receive data from an infrastructure equipment in a second band of frequencies  632  (in other words, a second carrier), such as the gNB  502  in  FIG.  5   . 
     It will be appreciated by a person skilled in the art that the transmission  610  from the communications device  501  to the gNB  502  is an example of uplink transmission and the reception  611  by the communications device  501  from the gNB  502  is an example of downlink reception. It will also be appreciated that the communications device  501  could be a user equipment (UE). 
     In the example in  FIG.  6   , there is a switching period  620  (which may also be referred to as a transmission/reception period)between the transmission  610  and the reception  611 . That is, there is a time delay  620  between the transmission  631  and reception  611  of data. 
     Generally therefore, compared with full duplex communication, additional latency in transmitting or receiving data can arise when using half duplex transmission because of the requirement to wait for any ongoing reception or transmission (respectively) to be completed and because of the switching period  620 . 
     HD-FDD devices may be eMTC and/or NB-IoT communications devices (or may operate in accordance with eMTC or NB-IoT principles) whereby the latency requirements do not impose a stringent latency requirement, as discussed above. In such cases, the additional latency associated with half duplex operation may be acceptable for an HD-FDD communications device. 
     Some services in 5G NR require a low latency, such as URLLC, and the latency  620  introduced by switching between transmission  610  and reception  602  in a HD-FDD device may have a relatively large impact on the service. 
     In a communication system, there may be a need for a communications device to both transmit and receive data. Where full duplex is possible, simultaneous uplink and downlink communications resources may be scheduled. However, if the communications device is half duplex, then it is necessary for the infrastructure equipment to avoid conflicts between uplink and downlink resources allocated to the same communications device, because transmission and reception cannot occur simultaneously in accordance with the half duplex capability of the communications device. A collision (referred to herein as an ‘intra-UE HD-FDD collision) may arise when first communication resources are to be used for transmission by an HD-FDD communications device, and second communication resources are to be used for reception by the same communications device, wherein the first and second communication resources are such that the HD-FDD communications device is unable to use both communication resources. An intra-UE HD-FDD collision may arise because the first and second communications resources overlap (at least partially) in time and/or because the first and second communications resources are not separated in time by the minimum required switching time  620 . 
     There may arise a case where communications resources are scheduled and allocated before the infrastructure equipment is aware of the need for a high priority/low latency transmission in the opposite direction. To avoid an intra-UE HD-FDD collision, the infrastructure equipment would not be able to allocated resources which conflict with the existing schedule, and it may therefore not be possible to meet latency requirements for the high priority/low latency transmission. In accordance with some embodiments of the present technique, the infrastructure equipment may schedule the high priority/low latency data in order to satisfy its latency requirements, thereby resulting in an intra-UE HD-FDD collision. 
     It has also been recognised that in some cases, communication resources may be wholly or partially autonomously selected by the communications device. For example, where predetermined communications resources are allocated (e.g. by means of semi-persistent scheduling, or for random access transmissions), the infrastructure equipment may not be aware of the selection of potentially conflicting communication resources by the communications device. 
     There may thus arise a possibility for an intra-UE HD-FDD collision, and there arises a technical problem of how to resolve such collisions. 
     Intra-UE HD-FDD Collision 
       FIG.  7    shows an illustrative example of an intra-UE FDD collision or conflict between an uplink transmission and a downlink reception which may occur in a HD-FDD device. The device may be configured with a service having low latency requirements, such as URLLC. In some examples, the device may be configured with more than one service. An example of a scenario to which  FIG.  7    may be applicable is a conflict between a scheduled uplink transmission and a scheduled downlink reception between a UE and a wireless communications network. 
       FIG.  7    shows a first band of frequencies  701  configured for transmitting data to the wireless communications network. The communication resources within the first band of frequencies  701  are divided into time slots in the time domain. In  FIG.  7   , five separate time slots  740 - 744  associated with the first band of frequencies are shown. In this example, each time slot is divided into 14 time units. Each time unit may correspond to, for example, an Orthogonal Frequency Division Multiplexing (OFDM) symbol period. It will be appreciated that a different number of time units in a time slot, and a different number of time slots into which the first band of frequencies is divided are also possible. 
       FIG.  7    also shows a second band of frequencies  702  configured for receiving data from the wireless communications network. The second band of frequencies  702  is divided into time slots, which are aligned with the time slots  740 - 744  used for the resources within the first band of frequencies  701 . In this example, each time slot is divided into 14 time units. Each time unit may correspond to, for example, an OFDM symbol period. It will be appreciated that a different number of time units in a time slot, and a different number of time slots into which the second band of frequencies is divided can be configured. 
     In the illustrative example in  FIG.  7   , a wireless communication network provides a first allocation  720 , on the second band of frequencies  702 , of first communication resources  723  to the UE at time t 0 . In the specific example, the first allocation  720  is downlink control information (DCI# 1 ). The first allocation  720  schedules first communication resources  723  for a transmission of data by the UE to the wireless communications network on the first band of frequencies  701  from time t 4  to t 5 , as shown by an arrow  710 . In the specific example, the transmission of data using the first communication resources  723  occurs on a Physical Uplink Shared Channel # 1  (PUSCH# 1 ). 
     At a time t 2 , after time t 1 , the UE receives from the wireless communications network, on the second band of frequencies  702 , a second allocation  721  of second communication resources  722  to the UE. In the specific example, the second allocation  721  is DCI# 2 . The second allocation  721  allocates (as indicated by an arrow  711 ) second communication resources  722  for the reception of data by the UE from the wireless communications network between t 4  and t 5 . In the specific example, the reception of data on the second communication resources  722  occurs on a Physical Downlink Shared Channel (PDSCH). In the example of  FIG.  7   , the second allocation  721  also schedules (as shown by an arrow  712 ) third communication resources  724  starting at time t 6  for a transmission of data from the UE to the wireless communications network. The data transmitted on the third communication resources  724  may include hybrid automatic repeat request (HARQ) acknowledgement (ACK) feedback information and may be transmitted on a Physical Uplink Control Channel (PUCCH). This data may include hybrid automatic repeat request (HARQ)-acknowledgement (ACK) feedback information. 
     In some embodiments, the second allocation  721  is transmitted in response to determining, by the infrastructure equipment  272 , that downlink data having a low latency tolerance (e.g. because it is URLLC data) is to be transmitted to the communications device  270 . The infrastructure equipment  272  determines that it is necessary to schedule the transmission of the downlink data within a certain time period (e.g. so that it is completely transmitted before time t 5 ), and allocates the second communication resources  722  accordingly. 
     As will be appreciated from  FIG.  7   , resources for the scheduled transmission of data  723  and the scheduled reception of data  722  have both been allocated between t 4  and t 5 . Since the UE in this example is an HD-FDD device, the device cannot simultaneously transmit and receive data. Therefore an intra-UE HD-FDD collision  740  occurs. As described above, the intra-UE HD-FDD collision  740  may arise because the infrastructure equipment  272  has determined that it is necessary to allocate the second communication resources  722  for downlink transmission to the communications device  270 . However, the present disclosure is not limited to any particular cause of the intra-UE HD-FDD collision. In particular, it should be appreciated that in some embodiments, the infrastructure equipment  272  allocates the second communication resources  722  for downlink transmission to the communications even though they may be incompatible with the first communications resources  723  allocated earlier. 
     As will be appreciated from the example embodiments described below for which  FIG.  7    provides an example representation of an FDD wireless access interface physical resources of the uplink channel may be divided into a plurality of time slots, each time slot including a plurality of the physical resources of the uplink channel, such as OFDM symbols, and the physical resources of the downlink channel may be divided into a plurality of time slots, each time slot including a plurality of the physical resources of the downlink channel such as OFDM symbols. Although  FIG.  7    and the following example provide an example that the time slots are synchronised on the uplink channel and the downlink channel, so that the plurality of time slots are the same, in other examples the time slots may be different in duration and numbers of OFDM symbols. However allocations of resource on the uplink and the downlink may also overlap in time. 
     The efficient handling of cases where intra-UE DL and UL transmissions collide in a communications device operating according to an HD-FDD mode of operation therefore represents a technical challenge. 
     The following described implementations may be applied when a communications device is configured with two different services. For example, a communications device may be configured with eMBB and URLLC. However, it will be appreciated that the present disclosure is not limited to the case when a communications device is configured with two different services, and may be applied to cases where the communications device is configured with one service or more than two services. 
     Slot Format 
     Slot format indicators (SFIs) have been used in the context of TDD. In this context, an SFI is used to indicate a format of the OFDM symbols in a slot. It is known that in TDD systems other than NR, there are cases where all OFDM symbols in the same slot must have the same format. For example, for an uplink transmission on a slot of first physical resources, all of the symbols in the slot have the format “U” (uplink). Similarly, for a downlink reception on a slot of second physical resources, all of the symbols in the slot have the format “D” (downlink) By contrast, it is a feature of NR that each of the symbols in a slot can have different indicated formats. The format of each symbol may be indicated as U, D or “F” (flexible). A flexible symbol supports both uplink transmission and downlink reception. The present invention reuses the slot format indicator in FDD in order to determine a priority between uplink transmission and downlink reception in a HD-FDD device. It is known in the art that individual OFDM symbols in a time slot can be classified with a defined application such as for example: ‘downlink’, ‘uplink’ or ‘flexible’. The slot formats can be determined by Radio Resource Control (RRC) signalling and/or DCI signalling. For example, a DCI signal sent from a wireless communications network to a communications device may contain a Slot format Indicator (SFI) or communication resources allocated to the communications device for uplink and/or downlink transmission. The allocated communication resources may be communication resources allocated for uplink (UL grant) or communication resources allocated for downlink (DL grant). 
     Slot format indicators have been used in the context of TDD. As explained above, in TDD, uplink transmission and downlink reception occur on the same carrier frequency, but separated in time. In a TDD mode of operation, at any point in time, all of the communications devices in a cell must be in an uplink communication mode or all of the communications devices in a cell must be in a downlink communication mode. In the uplink communication mode, a communications device in the cell cannot receive downlink data. In a downlink communication mode, the communications device in the cell cannot transmit uplink data. In the context of TDD, a single SFI can be indicated for an entire cell. 
     In accordance with some embodiments provided herein, in an FDD mode of operation, an SFI is independently indicated for a first band of frequencies configured for uplink transmission and a second band of frequencies configured for downlink reception. Each SFI may be indicated, for example, by means of a Group Common Physical Downlink Control Channel (GC-PDCCH). The combination of the two independently received SFIs is referred to as a dual SFI. As will be appreciated the first band of frequencies is used for transmitting uplink signals, whereas the second band of frequencies is used for receiving downlink signals. The present disclosure seeks to reuse the SFI to resolve intra-UE FDD collision when an uplink transmission allocated on the first band of frequencies overlaps in time with a downlink transmission allocated on the second band of frequencies. 
     In accordance with some of the embodiments described herein, the dual SFI may be used by the communications device to determine whether uplink transmission or downlink reception has priority. In particular, the dual SFI may be used by the communications device to determine whether to:
         If a scheduled uplink and downlink transmission collides, the combined SFI is used by the communications device to determine whether to drop the uplink transmission and use the downlink transmission or to drop the downlink transmission and use the uplink transmission. According to the illustrative example of  FIG.  7   , the dual SFI is used by the communications device to determine whether the communications device should transmit data on the PUSCH  723  and drop the reception of data on the PDSCH  722  or whether to receive data on the PDSCH  722  and drop transmission of data in the PUSCH  723 .   Cancel a scheduled transmission or reception of data   Switch from an ongoing uplink transmission to a downlink transmission or vice versa       

     UE Behaviour in the Case of a Collision Between UL Transmission and DL Reception 
       FIG.  8    shows a Frequency  851  against Time  852  graph illustrating an example of communication resources of a band of frequencies  801  which may be configured for the transmission of data from a communications device to a wireless communications network or for the reception of data by a communications device from a wireless communications network. The figure shows a single FDD time slot n  840  occupying the band of frequencies  801 . The time slot n  840  is divided into 14 time units  801   a - 801   n.  The time units may each correspond to an OFDM symbol period for example. It will be appreciated that a different number of time units in a time slot of the band of frequencies can be configured. 
     The band of frequencies  801  in  FIG.  8    may correspond to first physical communication resources configured for transmitting uplink data. Alternatively, the band of frequencies  801  may correspond to second communication resources configured for receiving downlink data. The band of frequencies comprises a plurality of OFDM symbols  801   a - 801   n.  From this point forward, the word “symbol” should be understood to convey the meaning of “OFDM symbol”. 
       FIG.  8    also shows an indication of the format of the symbols of the band of frequencies  801  indicated by an SFI. The labelling of the symbols is not intended to specify that a particular communications resource is used for uplink or downlink but is intended to show the indication of the format of the symbols in the SFI. For example, four of the symbols  801   a - 801   d  are indicated as downlink symbols, five of the symbols  801   e - 801   i  are indicated as flexible symbols and five of the symbols  801   j - 801   n  are indicated as uplink symbols. In this example, if the band of frequencies  801  is configured for transmitting uplink data, then it is not implied that a downlink reception is intended on the symbols indicated as downlink symbols  801   a - 801   d  in the band of frequencies  801 . The communications device uses the indication of the format of the symbols on the first band of frequencies and combines this with an indication of the format of symbols on a second band of frequencies configured for receiving downlink data to determine a use (for example to perform uplink transmission on the first band of frequencies  801  or perform downlink reception on the second band of frequencies) for the symbols. Accordingly, the skilled person will read references to “uplink”, “downlink” or “flexible” symbols to mean indications of the symbols as “uplink”, “downlink” or “flexible” in the SFI respectively. 
       FIG.  9    shows a first band of frequencies  801  configured for transmitting data to the wireless communications network (i.e. uplink transmission) and a second band of frequencies  802  configured for receiving data from a wireless communications network (i.e. downlink reception) in a time slot n  840 . The first band of frequencies  801  in this example has the same format as the band of frequencies  801  in  FIG.  8   . 
     The second band of frequencies  802  is also in the time slot n  840 . The time slot n  840  is divided into 14 time units  802   a - 802   n  for the second band of frequencies  802 . The time units may each correspond to an OFDM symbol for example. It will be appreciated that a different number of time units in a time slot of the band of frequencies can be configured. 
     In some embodiments, a separate SFI is used to indicate the format of the first band of frequencies  801  and the second band of frequencies  802 . For example, a first SFI may indicate the format of the first band of frequencies via a first half of a Group-Common Downlink Control Information (GC-DCI) transmitted by Group-Common Physical Downlink Control Channel (GC-PDCCH) and a second SFI may indicate the format of the second band of frequencies via a second half of the GC-DCI. In other examples, a first SFI may indicate the format of the first band of frequencies via a first Group-Common Physical Downlink Control Channel (GC-PDCCH) and a second SFI may indicate the format of the second band of frequencies via a second GC-PDCCH.  FIG.  9    shows that the symbols  802   a - 802   n  in the time slot n  840 of the second band of frequencies are all downlink symbols whereas the symbols  801   a - 801   n  in the time slot n  840  of the first band of frequencies  801  are not all downlink symbols. In the time slot n  840  of the first band of frequencies  801 , four symbols  801   a  to  801   d  are indicated as downlink symbols, five symbols  801   e  to  801   i  are indicated as flexible symbols and five symbols  801   j  to  801   n  are indicated as uplink symbols. 
     A dual slot format indicator (dual SFI) may be defined on the basis of at least one symbol of the first band of frequencies and a corresponding symbol occurring at the same point of time in the second band of frequencies. 
     For example,  FIG.  9    illustrates that four indicated downlink symbols of the first band of frequencies  801   a - 801   d  overlap in time  860  with four indicated downlink symbols of the second band of frequencies  802   a - 801   d.  The dual slot format indicator for the overlap time  860  may be labelled resource-DD  850 .  FIG.  9    also illustrates that five indicated flexible symbols of the first band of frequencies  801   e - 801   i  overlap in time  861  with five indicated downlink symbols of the second band of frequencies  802   e - 801   i.  The dual slot format indicator for the overlap time  861  may be labelled resource-DF  851 .  FIG.  9    also illustrates that five indicated uplink symbols of the first band of frequencies  801   j - 801   n  overlap in time  862  with five other indicated downlink symbols of the second band of frequencies  802   j - 801   n.  The dual slot format indicator for the overlap time  862  may be labelled resource-DU  852 . 
       FIG.  10    shows a first band of frequencies  801  configured for transmitting data to a wireless communications network and a second band of frequencies  802  configured for receiving data from the wireless communications network over three time slots  840 - 842 . The reference numerals for the individual symbols have been omitted in this illustration for clarity. The dual-SFI for the overlap of indicated downlink symbols on the first band of frequencies  801  with indicated flexible symbols on the second band of frequencies  802  may be labelled resource-FD  853 . The dual-SFI for the overlap of indicated flexible symbols on the first band of frequencies  801  with indicated flexible symbols on the second band of frequencies  802  may be labelled resource-FF  854 . The dual-SFI for the overlap of indicated uplink symbols on the first band of frequencies  801  with indicated flexible symbols on the second band of frequencies  802  may be labelled resource-FU  855 . The dual-SFI for the overlap of indicated downlink symbols on the first band of frequencies  801  with indicated uplink symbols on the second band of frequencies  802  may be labelled resource-UD  856 . The dual-SFI for the overlap of indicated flexible symbols on the first band of frequencies  801  with indicated uplink symbols on the second band of frequencies  802  may be labelled resource-UF  857 . The dual-SFI for the overlap of indicated uplink symbols on the first band of frequencies  801  with indicated uplink symbols on the second band of frequencies  802  may be labelled resource-UU  858 . 
     Table 1 shows the labelling of nine possible dual-SFIs based on the format of symbols in the first and second band of frequencies in the present embodiment. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 SFI in second band of frequencies 
               
            
           
           
               
               
               
               
            
               
                   
                 ‘D 
                 ‘U 
                 ‘F 
               
               
                   
                 (downlink)’ 
                 (uplink)’ 
                 (Flexible)’ 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 SFI in 
                 ‘D 
                 Resource- 
                 Resource- 
                 Resource- 
               
               
                 first band 
                 (downlink)’ 
                 DD 
                 UD 
                 FD 
               
               
                 of frequencies 
                 ‘U 
                 Resource- 
                 Resource- 
                 Resource- 
               
               
                   
                 (uplink)’ 
                 DU 
                 UU 
                 FU 
               
               
                   
                 ‘F 
                 Resource- 
                 Resource- 
                 Resource- 
               
               
                   
                 (Flexible)’ 
                 DF 
                 UF 
                 FF 
               
               
                   
               
            
           
         
       
     
     As will be explained below, the communications device may use the dual SFI to determine whether to transmit or receive data on the communication resources associated with the dual SFI in the case where the first communication resources and second communication resources overlap in time. 
     The communications device may receive from the wireless communications network a first allocation (such as DCI # 1   720 ) of first communication resources for transmitting data to the wireless communications network, and a second allocation (DCI # 2   721 ) of second communication resources for receiving data from the wireless communications network. The communications device may also receive a format (a slot format) of the first communication resources (indicated by a first SFI, for example) and a format of the second communication resources (indicated by a second SFI, for example). The communications device may then determine whether the first communication resources and the second communications overlap in time (for example, in  FIG.  7   , the first communications resources  723  overlap in time with the second communications resources  722 ). The communications device may the select on a basis of the format of the first communication resources and the format of the second communication resources, to either transmit data to the wireless communications network on the first communication resources or to receive data from the wireless communications network on the second communication resources; and either refrain from receiving data on the second communication resources if the communications device selects to transmit data on the first communication resources; or refrain from transmitting data on the first communication resources if the communications device selects to receive data on the second communication resources. 
     In some embodiments, the format of the first communication resources is indicated by a first SFI and the format of the second communication resources is indicated by a second SFI. In this embodiment, the combination of the format of symbols used for the first communications resources and the format of symbols used for the second communication resources is labelled by a dual SFI. 
     In some embodiments the communications device may determine that the first communication resources and the second communication resources overlap in time.  FIG.  11    is based on  FIG.  8    and the same reference numerals have been applied. As an example of this embodiment,  FIG.  11    indicates that the PUSCH transmission  890  (uplink transmission) scheduled on symbols that had been indicated as flexible symbols  801   e - 801   i  in the SFI of the first band of frequencies  801  overlaps in time  861  with the PDSCH reception  880  (downlink reception) scheduled on the five symbols that had been indicated as downlink symbols in the SFI  802   e - 802   i  of the second band of frequencies  802 . Therefore there is a collision between the uplink transmission and the downlink reception. In other words, the communications device determines that the first communication resources and the second communication resources overlap in time. The format of the flexible symbols  801   e - 801   i  of the first band of frequencies  801  and the format of the downlink symbols  802   e - 802   i  of the second band of frequencies  802  may be labelled as resource-DF  851  according to Table 1. The communications device determines, based on the format of symbols used for the first communication resources and the format of symbols used for the second communication resources, whether to transmit the scheduled uplink transmission on symbols indicated as flexible symbols in the SFI  801   e - 801   i  of the first band of frequencies  801  or to receive the scheduled downlink reception on symbols indicated as downlink symbols in the SFI  802   e - 802   i  of the second band of frequencies  802 . In the example, since the dual SFI indicates resource-DF for the overlapping resources, the communications device may prioritise downlink reception according to prioritisation rules that are defined in Table 2. In other words, the communications device determines, on the basis of resource-DF, to receive the scheduled downlink reception on downlink symbols  802   e - 802   i  of the second band of frequencies  802 . The communications device refrains from transmitting the scheduled uplink transmission on the symbols indicated as flexible symbols in the SFI  801   e - 801   i  of the first band of frequencies  801 . The communications device may determine whether to cancel or postpone the scheduled uplink transmission on the flexible symbols  801   e - 801   i  of the first band of frequencies  801 . 
     In a similar way, if it is determined that the dual SFI indicates resource-FU  855  for the overlapping resources, the communications device may prioritise uplink transmission on the corresponding symbols indicated as uplink symbols in the SFI of the first band of frequencies and refrain from receiving data on the corresponding symbols indicated as flexible symbols in the SFI of the second band of frequencies. The communications device may determine whether to cancel or postpone the scheduled downlink reception on the symbols indicated as flexible symbols in the SFI of the second band of frequencies  802 . 
     In some embodiments, the communications device cancels or postpones an uplink transmission scheduled on either a resource-DD or resource-FD, regardless of whether there is a collision between the scheduled uplink transmission and a scheduled downlink transmission. 
     In some embodiments, the communications device cancels or postpones an uplink transmission scheduled on either a resource-UU or resource-UF, regardless of whether there is a collision between the scheduled uplink transmission and a scheduled downlink transmission. 
     In some embodiments, the communications device may cancel or postpone both an uplink transmission and downlink reception scheduled on a resource-UD. 
     In some embodiments, if there is a collision between an uplink transmission and downlink transmission on a resource-DU or FF, the communications device may determine whether to transmit the uplink data or receive the downlink data on a basis of a type of allocation signalling and a timing of the allocation signalling. For example, if both downlink reception is scheduled by DCI# 1  and uplink transmission is scheduled by DCI# 2 , priority is given to the uplink transmission if DCI# 2  arrives at the communications device at a later time than DCI# 1  and vice versa. In an alternative example, if uplink transmission is scheduled by DCI (i.e. the uplink transmission is of type “scheduled by DCI”) and downlink transmission is scheduled by Radio Resource Control (RRC) Signalling (i.e. the downlink transmission is of type “scheduled by RRC”), uplink transmission is prioritised and vice versa. In other examples, the priority may depend on the type of channel (e.g. PDCCH, PUCCH, PDSCH, PUSCH, PRACH, PBCH) and signal (CSI-RS, PSS, SSS, SRS). For example, PBCH may be given the highest priority and PUCCH may be given a higher priority than PDCCH. 
     Table 2 is an example of how a communications device determines whether uplink transmission or downlink reception has priority based on a dual-SFI (in other words, based on the format of symbols used for the first communication resources and the format of symbols used for the second communication resources) when there is a scheduled collision between the uplink transmission and the downlink reception. It will be appreciated that the priority rules indicated herein are only examples. For example, the resource UD may not allow uplink transmission or downlink reception in an alternative example. 
     
       
         
           
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 SFI on Downlink spectrum 
               
            
           
           
               
               
               
               
            
               
                   
                 ‘D 
                 ‘U 
                 ‘F 
               
               
                   
                 (downlink)’ 
                 (uplink)’ 
                 (Flexible)’ 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 SFI on 
                 ‘D 
                 Only DL 
                 No UL or 
                 Only DL 
               
               
                 Uplink 
                 (downlink)’ 
                 data 
                 DL data 
                 data 
               
               
                 spectrum 
                 ‘U 
                 Depending on 
                 Only UL 
                 UL data is 
               
               
                   
                 (uplink)’ 
                 signalling 
                 data 
                 prioritised 
               
               
                   
                 ‘F 
                 DL data is 
                 Only UL 
                 Depending on 
               
               
                   
                 (Flexible)’ 
                 prioritised 
                 data 
                 signalling 
               
               
                   
               
            
           
         
       
     
     In other examples, on resource-UD, the communications device follows a prioritisation rule indicated in DCI or RRC. In other examples, on resource-UD, the communications device cancels both the uplink transmission and the downlink reception. 
     In other examples, when ‘D’ is indicated in the second band of frequencies for a communications device (i.e. Resource-DD, DU or DF), the communications device may only perform downlink reception on the resource. Accordingly, on Resource-DD, DU or DF, if uplink transmission is scheduled, the uplink transmission is cancelled or postponed. 
     In other examples, when ‘U’ is indicated in the first band of frequencies for a communications device (i.e. Resource-UU, DU or DU), the communications device may only perform uplink transmission on the resource. Accordingly, on Resource-UU, DU and FU, if downlink transmission is scheduled, the downlink transmission is cancelled or postponed. 
     In other examples, when ‘F’ is indicated in the first or second band of frequencies for a communications device (i.e. Resource-DF, FD, UF, FU, or FF), the communications device determines downlink reception or uplink transmission based on DCI and/or RRC signalling. 
     In other examples, when ‘D’ is indicated in the first band of frequencies for a communications device (i.e. Resource-DD, UD and FD), the communications device cancels or postpones any uplink transmissions including pre-configured uplink data. 
     In other examples, when ‘U’ is indicated in the second band of frequencies for a communications device (i.e. Resource-UD, UU and UF), the communications device cancels or postpones any downlink receptions including pre-configured downlink data. 
     In other examples, ‘U’ is not indicated in the second band of frequencies and ‘D’ is not indicated in first band of frequencies. In other words, only either ‘D’ or ‘F’ is indicated in the second band of frequencies, and only either ‘U’ or ‘F’ is indicated in the first band of frequencies. If a communications device receives an SFI with ‘U’ in the second band of frequencies or ‘D’ in the first band of frequencies, the communications device assumes the received SFI is in error. 
     In other examples, the communications device does not receive an indication of the format of the first band of frequencies and/or the format of the second band of frequencies. According to some examples, the communications device does not receive an SFI. This may occur, for example, if a gNB did not transmit an SFI or if the communications device cannot successfully receive the SFI. In this example, the communications device may prioritise downlink reception over uplink transmission. That is, if uplink transmission and downlink reception are scheduled on the same resource then the communications device cancels or postpones the scheduled uplink transmission. 
     In other examples, the communications device may receive, by an RRC signal from the wireless communications network, a pre-configured format of the first band of frequencies and/or a pre-configured format of the second band of frequencies. These pre-configured formats may be the same for all communications devices in the same cell (i.e. cell-specific formats) or may be unique to each communications device in a cell (i.e. communication device-specific formats). Hence in some examples, the RRC signalling indicates a pre-configured format for one of the bands of frequencies and dynamic SFI signalling indicates a format for the other band of frequencies. 
     UE Behaviour for Cancelled or Postponed Data 
     In some embodiments, if it is determined that the first communication resources and the second communication resources overlap in time and the communications device selects whether to transmit data on the first communication resources or receive data on the second communication resources, the communications device determines whether to cancel or postpone the transmission (if the reception is selected) or whether to cancel or postpone the reception (if the transmission is selected). 
     In some embodiments, the determining whether to cancel or postpone the transmission or the reception may be defined by a specification for a system so that the determination is pre-determined. 
     In some embodiments, the determining whether to cancel or postpone the transmission or the reception may be indicated by a Radio Resource Control (RRC) signal received by the communications device from the wireless communications network. 
     In some embodiments, the RRC signal or the specification indicates to the communications device that, if a transmission on the first communication resources has been selected, to cancel reception of data on the second communication resources. 
     In some embodiments, the RRC signal or the specification indicates to the communications device that, if a reception on the second communication resources has been selected, to cancel transmission of data on the second communication resources. 
     In some embodiments, the cancelling or the postponing of the transmission or the reception may apply to only part of the transmission or the reception respectively. For example, if the first communication resources and the second communication resources overlap only partly in time, and the communications device selects that it should transmit data on the first communication resources, then the communications device may only cancel or postpone the part of the second communication resources which overlapped with the first communication resources. 
       FIG.  12    is based on  FIG.  11    and the same reference numerals have been applied.  FIG.  12    indicates that a scheduled PUSCH transmission  890  (uplink transmission) on the five flexible symbols  801   e - 801   i  of the first band of frequencies  801  overlap in time  861  with a scheduled PDSCH transmission (downlink reception)  870  on a downlink symbol  802   g  of the second band of frequencies  802 . Therefore there is a collision between the uplink transmission and the downlink reception. The format of the flexible symbols  801   e - 801   i  of the first band of frequencies  801  and the format of the downlink symbols  802   e - 802   i  of the second band of frequencies  802  may be labelled as resource-DF according to Table 1. In this example, the first communication resources overlap with the second communication resources only partly. That is, the downlink symbol  802   g  on which the PDSCH is scheduled overlaps in time with one  801   g  of the flexible symbols  802   e - 802   i  on which the PUSCH is scheduled. According to Table 2, downlink reception is prioritised on resource-DF. The communications device therefore determines to receive the downlink reception on the downlink symbol  802   g  on which the PDSCH is scheduled. In one embodiment, the communications device determines to cancel or postpone only the symbol  801   g  on which the PUSCH was scheduled. In this embodiment, the PUSCH transmission scheduled on non-overlapping symbols  801   e,    801   f,    801   h,    801   i  may be allowed to proceed. In other embodiments, only the PUSCH transmission scheduled on non-overlapping symbols which occur before the collision  801   e,    801   f  may be allowed to proceed. In this embodiment, the communications device determines to postpone or cancel the PUSCH transmission scheduled on the symbols  801   g - 801   i  which occur during and after the collision. 
     In some embodiments, the format of the first band of frequencies and the second band of frequencies can be used to determine, if a transmission/reception is to be cancelled or postponed, whether to only cancel or postpone the scheduled transmission/reception on symbols which overlap or whether to cancel or postpone the entire scheduled transmission/reception from the time at which overlap occurs until the end of the transmission/reception. 
     As illustrative examples,
         Resource-DF may indicate that uplink transmission is cancelled or postponed for the overlapping symbol only.   Resource-FD may indicate that uplink transmission is cancelled or postponed for the overlapping symbol and the rest of the transmission.       

     In other embodiments, some dual-SFI combinations can be associated with “cancellation functionality” and other dual-SFI combinations can be associated with “postponement functionality”. For example:
         Resource-DF may indicate that uplink transmission is cancelled.   Resource-FD may indicate that uplink transmission is postponed       

     The above two embodiments can be combined, for example, such that some dual-SFI combinations indicate that single overlapping symbols are cancelled while other combinations indicate that the rest of the transmission is postponed. For example:
         Resource-DF may indicate that the single overlapping symbol is cancelled in the uplink transmission.   Resource-FD may indicate that the overlapping symbol and the rest of the uplink transmission is postponed.       

     It will be appreciated that the phrase “communication resources” used herein may alternatively be referred to as “physical resources”. 
     As will be appreciated from the above explanation, embodiments of the present disclosure can resolve a conflict between allocations of the uplink channel and the downlink channel which overlap in time, wherein the resolving the conflict is by combining the first and second format indicators, which may be slot format indicators (SFI) to form dual-SFIs. Although SFI are known for signalling a format for applying the physical resources of a time slot in a TDD system, the SFI has been redeployed to indicate how a collision or conflict should be resolved when this occurs as a result of conflicting service level requirements in an HD-FDD system. 
     Summary of Operation 
     A flow diagram summarising an operation of a communications device according to an example embodiment is shown in  FIG.  13   .  FIG.  13    is summarised as follows: 
     After the start S 1302  of the operation, a UE receives a first format indicator for an uplink channel of a wireless access interface provided by the wireless communications network S 1304 . The first format indicator may be a first SFI. The first SFI may have been transmitted to the UE from an infrastructure equipment forming part of the wireless communications network by means of a GC-PDCCH. The format indicated by the first SFI may have been an indication of whether each OFDM symbol of the uplink channel is indicated as “uplink”, “downlink” or “flexible”. 
     Next, the UE receives a second format indicator for a downlink channel of a wireless access interface provided by the wireless communications network S 1306 . The second format indicator may be a second SFI. The second SFI may have been transmitted to the UE from an infrastructure equipment forming part of the wireless communications network by means of a GC-PDCCH. The format indicated by the second SFI may have been an indication of whether each OFDM symbol of the downlink channel is indicated as “uplink”, “downlink” or “flexible”. 
     Next, the UE receives a first allocation of first physical resources S 1308  of an uplink channel. The first allocation may be a first DCI. The first DCI may include an indication as to the frequency and time range over which an uplink transmission is scheduled on the uplink channel. 
     Next, the UE receives a second allocation of second physical resources S 1310  of a downlink channel. The second allocation may be a second DCI. The second DCI may include an indication as to the frequency and time range over which an downlink reception is scheduled on the downlink channel. 
     Next, the UE determines that one or more of the first physical resources of the uplink channel and one or more of the second physical resources of the downlink channel overlap in time S 1312 . The UE may determine that one or more OFDM symbols of the first physical resources on which an uplink transmission has been scheduled overlap in time with one or more OFDM symbols of the second physical resources on which a downlink reception has been scheduled. 
     Next, the UE determines, on a basis of the first format indicator for the uplink channel and the second format indicator for the downlink channel, a use of each of the one or more first physical resources and the one or more second physical resources which overlap in time S 1314 . The UE may determine the use of the overlapping first and second physical resources based on a combination of the format of the first physical resources and the second physical resources indicated by the first format indicator and the second format indicator respectively. If the first format indicator is a first SFI and the second format indicator is a second SFI, then the UE may combine the formats indicated by the first and second SFI to form a dual SFI. The UE may then determine the use of the overlapping physical resources on the basis of the dual SFI. The UE may determine that the overlapping first physical resources should be used for a scheduled uplink transmission and that UE should refrain from a scheduled downlink reception on the overlapping second physical resources or vice versa. The UE may determine whether to cancel or to postpone the scheduled uplink transmission/downlink reception which the UE refrains from using. After the UE has determined a use for the overlapping physical resources, the operation ends S 1316 . 
     It will be appreciated that while the present disclosure has in some respects focused on implementations in an LTE-based and/or 5G network for the sake of providing specific examples, the same principles can be applied to other wireless telecommunications systems. Thus, even though the terminology used herein is generally the same or similar to that of the LTE and 5G standards, the teachings are not limited to the present versions of LTE and 5G and could apply equally to any appropriate arrangement not based on LTE or 5G and/or compliant with any other future version of an LTE, 5G or other standard. 
     It may be noted various example approaches discussed herein may rely on information which is predetermined/predefined in the sense of being known by both the base station and the communications device. It will be appreciated such predetermined/predefined information may in general be established, for example, by definition in an operating standard for the wireless telecommunication system, or in previously exchanged signalling between the base station and communications devices, for example in system information signalling, or in association with radio resource control setup signalling, or in information stored in a SIM application. That is to say, the specific manner in which the relevant predefined information is established and shared between the various elements of the wireless telecommunications system is not of primary significance to the principles of operation described herein. It may further be noted various example approaches discussed herein rely on information which is exchanged/communicated between various elements of the wireless telecommunications system and it will be appreciated such communications may in general be made in accordance with conventional techniques, for example in terms of specific signalling protocols and the type of communication channel used, unless the context demands otherwise. That is to say, the specific manner in which the relevant information is exchanged between the various elements of the wireless telecommunications system is not of primary significance to the principles of operation described herein. 
     It will be appreciated that the principles described herein are not applicable only to certain types of communications device, but can be applied more generally in respect of any types of communications device, for example the approaches are not limited to URLLC/IIoT devices or other low latency communications devices, but can be applied more generally, for example in respect of any type of communications device operating with a wireless link to the communication network. 
     It will further be appreciated that the principles described herein are applicable not only to LTE-based or 5G/NR-based wireless telecommunications systems, but are applicable for any type of wireless telecommunications system that supports a dynamic scheduling of shared communication resources. 
     Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. It will be appreciated that features of the dependent claims may be combined with features of the independent claims in combinations other than those explicitly set out in the claims. 
     Thus, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting of the scope of the invention, as well as other claims. The disclosure, including any readily discernible variants of the teachings herein, define, in part, the scope of the foregoing claim terminology such that no inventive subject matter is dedicated to the public. 
     Respective features of the present disclosure are defined by the following numbered paragraphs: 
     Paragraph 1. A method of transmitting and/or receiving data by a communications device operating according to a Half Duplex Frequency Division Duplex mode of operation (HD-FDD) in a wireless communications network, the method comprising
         receiving a first format indicator for an uplink channel of a wireless access interface provided by the wireless communications network for transmitting uplink data to the wireless communications network,   receiving a second format indicator for a downlink channel of the wireless access interface provided by the wireless communications network for receiving downlink data from the wireless communications network,   receiving, by the communications device, from the wireless communications network a first allocation of first physical resources allocated from physical resources of the uplink channel for transmitting uplink data to the wireless communications network;   receiving from the wireless communications network a second allocation of second physical resources allocated from physical resources of the downlink channel for receiving downlink data from the wireless communications network;   determining that one or more of the first physical resources of the uplink channel and one or more of the second physical resources of the downlink channel overlap in time;   determining, on a basis of the first format indicator for the uplink channel and the second format indicator for the downlink channel, a use of each of the one or more first physical resources and the one or more second physical resources which overlap in time,   wherein the first format indicator defines a format for each of the physical resources of the uplink channel, and the second format indicator defines a format for each of the physical resources of the downlink channel.       

     Paragraph 2. A method according to paragraph 1, wherein the determining on the basis of the first format indicator for the uplink channel and the second format indicator for the downlink channel the use of each of the one or more first physical resources and the one or more second physical resources which overlap comprises,
         combining for each of the one or more first physical resources of the uplink channel and the one or more second physical resources of the downlink channel which overlap in time, the defined format from the first format indicator and the second format indicator, and   determining the use of each of the one or more first physical resources and the one or more second physical resources which overlap in time based on the combined first and second format indicators according to a predetermined rule.       

     Paragraph 3. A method according to paragraph 1 or 2, wherein the physical resources of the uplink channel are divided into a plurality of time slots, each time slot including a plurality of the physical resources of the uplink channel, and the physical resources of the downlink channel are divided into a plurality of time slots, each time slot including a plurality of the physical resources of the downlink channel, and the first format indicator identifies the format for each of the physical resources of the uplink channel by identifying for each of the plurality of the physical resources of each time slot of the uplink channel a defined application of each of the plurality of the physical resources of the uplink channel, and the second format indicator identifies the format for the physical resources of the downlink channel by identifying for each of the plurality of the physical resources of each time slot of the downlink channel a defined application of each of the plurality of the physical resources of the downlink channel. 
     Paragraph 4. A method according to paragraph 3, wherein the defined application of each of the plurality of the physical resources of the first format indicator and the second format indicator comprises one of set of possible applications of the physical resource. 
     Paragraph 5. A method according to paragraph 4, wherein the set of possible applications comprises use of the physical resource for uplink transmission, U, use of the physical resource for downlink transmission, D, and flexible use of the physical resource for either uplink or downlink transmission, F. 
     Paragraph 6. A method according to any of paragraphs 1 to 5, wherein the physical resources of the uplink channel and the physical resources of the downlink channel comprise Orthogonal Frequency Division Multiplexed, OFDM, symbols, the first format indicator defining the format for each of the OFDM symbols of the uplink channel, and the second format indicator defining the format for each of the OFDM symbols of the downlink channel. 
     Paragraph 7. A method according to paragraph 6, wherein the combining the defined format from the first format indicator and the second format indicator, for each of the one or more first OFDM symbols of the uplink channel and the one or more second OFDM symbols of the downlink channel which overlap in time, comprises
         combining the defined application for the one or more first OFDM symbols of the uplink channel with the defined application for the corresponding overlapping one or more second OFDM symbols of the downlink channel.       

     Paragraph 8. A method according to paragraph 7, wherein the determining the use of each of the one or more first OFDM symbols and the one or more second OFDM symbols which overlap based on the combined first and second format indicators according to a predetermined rule comprises
         using the combined defined application for the one or more first OFDM symbols of the uplink channel with the defined application for the corresponding overlapping one or more second OFDM symbols of the downlink channel to identify a predetermined use of the one or more first OFDM symbols of the uplink channel and the corresponding overlapping one or more second OFDM symbols of the downlink channel according to a predetermined rule.       

     Paragraph 9. A method of paragraph 8, wherein the using the combined defined application for the one or more first OFDM symbols of the uplink channel with the defined application for the corresponding overlapping one or more second OFDM symbols of the downlink channel comprises using the combined defined application to identify the predetermined use in a look-up table. 
     Paragraph 10. A method according to any of paragraphs 7 to 9, wherein the one or more of the first physical resources and the one or more second physical resources overlap in time if at least one of the plurality of OFDM symbols of the first physical resources overlaps in time with at least one of the plurality of OFDM symbols of the second physical resources. 
     Paragraph 11. A method according to any of paragraphs 1 to 5, wherein the determining the use of the one or more first physical resources and the one or more second physical resources which overlap comprises selecting either
         to transmit the uplink data to the wireless communications network on the one or more of the first physical resources of the uplink channel which overlap the one or more second physical resources of the downlink channel, or   to receive the downlink data from the wireless communications network on the one or more of the second physical resources of the downlink channel which overlap the one or more of the first physical resources of the uplink channel.       

     Paragraph 12. A method according to any of paragraphs 1 to 5, wherein the determining the use of the one or more first physical resources and the one or more second physical resources which overlap in time comprises selecting either
         to refrain from receiving data on the one or more second physical resources of the downlink channel, if the communications device selects to transmit the uplink data on the one or more first physical resources of the uplink channel; or   to refrain from transmitting the uplink data on the one or more first physical resources of the uplink channel, if the communications device selects to receive the downlink data on the one or more second physical resources of the downlink channel.       

     Paragraph 13. A method according to paragraph 12, wherein the refraining from receiving the downlink data on the one or more second physical resources of the downlink channel comprises selecting either to cancel or to postpone the reception of downlink data on the one or more second physical resources of the downlink which overlap in time with the one or more physical resources of the uplink channel. 
     Paragraph 14. A method according to paragraph 12 or 13, wherein the refraining from transmitting the uplink data on the one or more first physical resources of the uplink channel comprises selecting either to cancel or to postpone the transmission of the uplink data on the one or more first physical resources of the uplink channel. 
     Paragraph 15. A method according to paragraph 13, wherein the selecting either to cancel or to postpone the reception of the downlink data on the one or more second physical resources of the downlink channel is based on the defined format of each of the one or more physical resources of the first and second physical resources which overlap in time. 
     Paragraph 16. A method according to paragraph 14, wherein the selecting either to cancel or to postpone the transmission of the uplink data on the one or more first physical resources of the uplink channel is based on the defined format of each of the one or more physical resources of the one or more first and second physical resources which overlap in time. 
     Paragraph 17. A method according to paragraph 15, wherein the selecting either to cancel or to postpone the reception of the downlink data on the one or more second physical resources of the downlink channel is pre-specified. 
     Paragraph 18. A method according to paragraph 16, wherein the selecting either to cancel or to postpone the transmission of the uplink data on the one or more first physical resources of the uplink channel is pre-specified. 
     Paragraph 19. A method according to paragraph 15, wherein the selecting either to cancel or to postpone the reception of the downlink data on the one or more second physical resources of the downlink channel is based on a Radio Resource Control (RRC) signal received by the communications device from the wireless communications network. 
     Paragraph 20. A method according to paragraph 16, wherein the selecting either to cancel or to postpone the transmission of the uplink data on the one or more first physical resources of the uplink channel is based on RRC signalling received by the communications device from the wireless communications network. 
     Paragraph 21. A method according to any of paragraphs 11 to 20, comprising determining, on the basis of the format of the one or more of the first physical resources and the format of the one or more of the second physical resources, that the refraining from receiving the downlink data on the second physical resources of the downlink only applies to a portion of the second physical resources which overlaps in time with the first physical resources. 
     Paragraph 22. A method according to any of paragraphs 11 to 21, comprising determining, on the basis of the format of the one or more first physical resources and the format of the one or more second physical resources, that the refraining from transmitting data on the one or more first physical resources only applies to the portion of the one or more first physical resources which overlaps in time with the one or more second physical resources. 
     Paragraph 23. The method according to any of paragraphs 11 to 22, comprising determining, on the basis of the format of the one or more first physical resources and the format of the one or more second physical resources, that the refraining from receiving the one or more second physical resources applies to the portion of the one or more second physical resources which overlaps in time with the one or more first physical resources and a remaining portion of the one or more second physical resources indicated by the second allocation. 
     Paragraph 24. The method according to any of paragraphs 11 to 23, comprising determining, on the basis of the format of the one or more first physical resources and the format of the one or more second physical resources, that the refraining from transmitting the one or more first physical resources applies to the portion of the one or more first physical resources which overlaps in time with the one or more second physical resources and a remaining portion of the one or more first physical resources indicated by the first allocation. 
     Paragraph 25. A communications device for transmitting and/or receiving data operating according to a Half Duplex Frequency Division Duplex mode of operation (HD-FDD) in a wireless communications network, comprising
         receiver circuitry configured to receive signals from the wireless communications network transmitted via a downlink channel of a wireless access interface provided by the wireless communications network,   transmitter circuitry configured to transmit signals to the wireless communications network via an uplink channel of the wireless access interface, and   controller circuitry configured to control the receiver circuitry   to receive a first format indicator for the uplink channel of the wireless access interface provided by the wireless communications network for transmitting uplink data to the wireless communications network,   to receive a second format indicator for the downlink channel of the wireless access interface provided by the wireless communications network for receiving downlink data from the wireless communications network,   to receive, by the communications device, from the wireless communications network a first allocation of first physical resources allocated from physical resources of the uplink channel for transmitting uplink data to the wireless communications network;   to receive from the wireless communications network a second allocation of second physical resources allocated from physical resources of the downlink channel for receiving downlink data from the wireless communications network; and the controller circuitry is configured   to determine that one or more of the first physical resources of the uplink channel and one or more of the second physical resources of the downlink channel overlap in time;   to determine, on a basis of the first format indicator for the uplink channel and the second format indicator for the downlink channel, a use of each of the one or more first physical resources and the one or more second physical resources which overlap in time, wherein the first format indicator defines a format for each of the physical resources of the uplink channel, and the second format indicator defines a format for each of the physical resources of the downlink channel.       

     REFERENCES 
     [1] RP-182090, “Revised SID: Study on NR Industrial Internet of Things (IoT),” 3GPP RAN#81. 
     [2] 3GPP TR 38.913 “Study on scenarios and requirements for next generation access technologies” 
     [3] 3GPP document RP-193238, “New SID on support of reduced capability NR devices,” Ericsson, RAN#86. 
     [4] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009.