Methods, communications devices, and infrastructure equipment

Abstract

A method of operating a communications device is provided. The method comprises receiving a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network. The PWS signal comprises one or more of: i) a PWS message comprising content of a public warning, ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, or iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended. The PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

Description

[0001] METHODS, COMMUNICATIONS DEVICES, AND INFRASTRUCTURE EQUIPMENT BACKGROUND

[0002] Field of Disclosure

[0003] The present disclosure relates to communications devices and infrastructure equipment of wireless communications networks and methods of operating such communications devices and infrastructure equipment.

[0004] The present disclosure claims Paris Convention priority from EP application number EP 25166727.5, filed on 27 March 2025, the contents of which are hereby incorporated by reference in their entirety.

[0005] Description of Related Art

[0006] The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

[0007] Previous generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support a wider range of services than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy such networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to continue to increase rapidly.

[0008] Current and future wireless communications networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic profiles and types than existing systems are optimised to support. For example, it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets, extended Reality (XR) and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of device, for example supporting high-definition video streaming, may be associated with transmissions of relatively large amounts of data with relatively low latency tolerance. Other types of device, for example used for autonomous vehicle communications and for other critical applications, may be characterised by data that should be transmitted through the network with low latency and high reliability. A single device type might also be associated with different traffic profiles I characteristics depending on the application(s) it is running. For example, different consideration may apply for efficiently supporting data exchange with a smartphone when it is running a video streaming application (high downlink data) as compared to when it is running an Internet browsing application (sporadic uplink and downlink data) or being used for voice communications by an emergencyresponder in an emergency scenario (data subject to stringent reliability and latency requirements).

[0009] In view of this there is expected to be a desire for current wireless communications networks, for example those which may be referred to as 5G or new radio (NR) systems I new radio access technology (RAT) systems, or indeed future 6G wireless communications, as well as future iterations I releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements. The desire to support these new use-cases and scenarios gives rise to new challenges for efficiently handling communications in wireless communications systems that need to be addressed.

[0010] SUMMARY OF THE DISCLOSURE

[0011] The present disclosure can help address or mitigate at least some of the issues discussed above.

[0012] 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.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein:

[0015] Figure 1 schematically represents some aspects of an LTE-type wireless telecommunication system which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0016] Figure 2 schematically represents some aspects of an NR-type wireless telecommunications system which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0017] Figure 3 is a schematic block diagram of an example infrastructure equipment and communications device which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0018] Figure 4 is a message flow diagram showing a typical four-step random access (RACH) procedure;

[0019] Figure 5 is a message flow diagram showing a typical two-step RACH procedure;

[0020] Figure 6 is reproduced from [6], and illustrates a first example of a non-terrestrial network (NTN) featuring an access networking service based on a satellite / aerial platform with a bent pipe payload;

[0021] Figure 7 is reproduced from [6], and illustrates a second example of an NTN featuring an access networking service based on a satellite / aerial platform that incorporates a gNodeB;Figure 8 schematically shows an example of a wireless communications system comprising an NTN part and a terrestrial network (TN) part which may be configured to operate in accordance with embodiments of the present disclosure;

[0022] Figure 9 is a flow diagram illustrating a method of operating a communications device in accordance with example embodiments;

[0023] Figure 10 schematically illustrates an example of a MAC CE design in accordance with example embodiments;

[0024] Figure 11 schematically illustrates another example of a MAC CE design in accordance with example embodiments;

[0025] Figure 12 is a flow diagram illustrating a method of operating a communications device in accordance with example embodiments.

[0026] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Long Term Evolution Advanced Radio Access Technology (4G)

[0028] Figure 1 provides a schematic diagram illustrating some basic functionality of a mobile telecommunications network I system 6 operating generally in accordance with LTE principles, but which may also support other radio access technologies, and which may be adapted to implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body, and also described in many books on the subject, for example, Holma H. and Toskala A [1], It will be appreciated that operational aspects of the telecommunications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

[0029] The network 6 includes a plurality of base stations 1 connected to a core network 2, which may be for example an Evolved Packet Core (EPC). Each base station provides a coverage area 3 (i.e. , a cell) within which data can be communicated to and from communications devices 4. Although each base station 1 is shown in Figure 1 as a single entity, the skilled person will appreciate that some of the functions of the base station may be carried out by disparate, interconnected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

[0030] Data is transmitted from base stations 1 to communications devices 4 within their respective coverage areas 3 via a radio downlink (DL). Data is transmitted from communications devices 4 to the base stations 1 via a radio uplink (UL). The core network 2 routes data to and from the communications devices 4 via the respective base stations 1 and provides functions such as authentication, mobility management, charging and so on. Communications devices may also be referred to as mobile stations, user equipment (UE), user terminal, mobile radio, communications device, and so forth. Services provided by the core network 2 may include connectivity to the internet or to external telephony services. The core network 2 may further track the location of the communications devices 4 so that it can efficiently contact (i.e., page) the communications devices 4 for transmitting downlink data towards the communications devices 4.

[0031] A base station for 4G LTE, which is an example of network infrastructure equipment, may also be referred to as a transceiver station, eNodeB, eNB, ng-eNB, EUTRAN node and so forth. Inthis regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality.

[0032] However, certain embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

[0033] New Radio Access Technology (5G)

[0034] Systems incorporating NR technology are expected to support different services (or types of services), which may be characterised by different requirements for latency, data rate and / or reliability. For example, Enhanced Mobile Broadband (eMBB) services are characterised by high capacity with a requirement to support up to 20 Gb / s. The requirements for Ultra Reliable and Low Latency Communications (URLLC) services are for one transmission of a 32 byte packet to be transmitted from the radio protocol layer 2 / 3 SDU ingress point to the radio protocol layer 2 / 3 SDU egress point of the radio interface within 1 ms with a reliability of 1 - 10-5 (99.999 %) or higher (99.9999%) [2],

[0035] An example configuration of a wireless communications network which uses some of the terminology proposed for and used in NR and 5G is shown in Figure 2. In Figure 2 a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 by a connection interface represented as a line 16. Each of the TRPs 10 is arranged to transmit and receive signals via a wireless access interface within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 10, forms a cell of the wireless communications network as represented by a circle 12. As such, wireless communications devices (e.g. a UE) 14 which are within a radio communications range provided by the cells 12 can transmit and receive signals to and from the TRPs 10 via the wireless access interface. Each of the distributed units 41, 42 are connected to a central unit (CU) 40 (which may be referred to as a controlling node) via an interface 46. The central unit 40 is then connected to the core network 20 (which may be for example referred to as 5GC) which may contain all other functions required to transmit data for communicating to and from the wireless communications devices and the core network 20 may be connected to other networks 30. In one or more embodiments disclosed herein, one or more TRP(s) 10, one or more DU(s) and one CU can be included in a base station.

[0036] The base station for 5G NR, which is an example of network infrastructure equipment, may also be referred to as gNodeB, gNB, en-gNB, NG RAN node and so forth.

[0037] Additionally, if the base station is for 6G, the base station may also be referred as 6G Node B, 6G RAN node. Alternatively or additionally, the base station for 5G (e.g., gNodeB, gNB, NG RAN node) can be also used as the base station for 6G.

[0038] In one or more embodiments disclosed herein, a DU is a logical node hosting RLC, MAC and PHY layers of the base station. The DU operation is partly controlled by a CU. One DU may support one or multiple cells. One cell may be supported by only one DU. The DU may terminate the intra-base station interface (e.g. F1 interface) connected with the CU. The CU is a logical node hosting RRC, SDAP and PDCP protocols of the base station. The CU may controlthe operation of one or more Dlls. The CU may terminate the intra-base station interface (e.g. F1 interface) connected with the DU. Additionally or alternatively, TRP 10 may be also called as RU (Radio Unit) or RRU (Remote Radio Unit). In one or more embodiments disclosed herein, TRP 10 (e.g. RU or RRU) may host part of the PHY layer (lower PHY layer). In this case, the DU may host the remaining PHY layer (higher PHY layer). One TRP may support one or multiple cells. Alternatively, Two or more TRPs may form one or more cells.

[0039] The elements of the wireless access network shown in Figure 2 may operate in a similar way to corresponding elements of an LTE network as described with regard to the example of Figure 1. It will be appreciated that operational aspects of the telecommunications network represented in Figure 2, and of other networks discussed herein in accordance with embodiments of the disclosure, which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to currently used approaches for implementing such operational aspects of wireless telecommunications systems, e.g. in accordance with the relevant standards.

[0040] The TRPs 10 of Figure 2 may in part have a corresponding functionality to a base station (e.g., eNodeB of an LTE network, gNB of an NR network, or 6G Node B of 6G network). Similarly, the communications devices 14 may have a functionality corresponding to the UE devices 4 known for operation with an LTE, NR or 6G network. It will be appreciated therefore that operational aspects of a new RAT network (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be different to those known from LTE or other known mobile telecommunications standards.

[0041] However, it will also be appreciated that each of the core network component, base stations and communications devices of a new RAT network will be functionally similar to, respectively, the core network component, base stations and communications devices of an LTE wireless communications network.

[0042] In terms of broad top-level functionality, the core network 20 connected to the new RAT telecommunications system represented in Figure 2 may be broadly considered to correspond with the core network 2 represented in Figure 1, and the respective central units 40 and their associated distributed units 42 I TRPs 10 may be broadly considered to provide functionality corresponding to the base stations 1 of Figure 1. The term network infrastructure equipment I access node may be used to encompass these elements and more conventional base station type elements of wireless telecommunications systems. Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the communications devices may lie with the controlling node I central unit and I or the distributed units I TRPs. A communications device 14 is represented in Figure 2 within the coverage area of the first communication cell 12. This communications device 14 may thus exchange signalling with the first central unit 40 in the first communication cell 12 via one of the distributed units I TRPs 10 associated with the first communication cell 12.

[0043] It will further be appreciated that Figure 2 represents merely one example of a proposed architecture for a new RAT based telecommunications system in which approaches in accordance with the principles described herein may be adopted, and the functionality disclosed herein may also be applied in respect of wireless telecommunications systems having different architectures.Thus, certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems I networks according to various different architectures, such as the example architectures shown in Figures 1 and 2. It will thus be appreciated the specific wireless telecommunications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a communications device, wherein the specific nature of the network infrastructure equipment I 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 I access node may comprise a base station, such as an LTE-type base station 1 as shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment may comprise a control unit I controlling node 40 and / or a TRP 10 of the kind shown in Figure 2 which is adapted to provide functionality in accordance with the principles described herein.

[0044] A more detailed diagram of some of the components of the network shown in Figure 2 is provided by Figure 3. In Figure 3, a TRP 10 as shown in Figure 2 comprises, as a simplified representation, a wireless transmitter 30, a wireless receiver 32 and a controller or controlling processor 34 which may operate to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within a cell 12 formed by the TRP 10. As shown in Figure 3, an example UE 14 is shown to include a corresponding transmitter 49, a receiver 48 and a controller 44 which is configured to control the transmitter 49 and the receiver 48 to transmit signals representing uplink data to the wireless communications network via the wireless access interface formed by the TRP 10 and to receive downlink data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with the conventional operation.

[0045] The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers and transceivers described in relation to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices in order to transmit and receive radio signals in accordance for example with the 5G / NR standard. The controllers 34, 44 (as well as other controllers described in relation to examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc., configured to carry out instructions which are stored on a computer readable medium, such as a non-volatile memory. The processing steps described herein may be carried out by, for example, a microprocessor in conjunction with a random access memory, operating according to instructions stored on a computer readable medium. The transmitters, the receivers and the controllers are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) I circuitry I chip(s) I chipset(s). As will be appreciated the infrastructure equipment I TRP I base station as well as the UE I communications device will in general comprise various other elements associated with its operating functionality.

[0046] As shown in Figure 3, the TRP 10 also includes a network interface 50 which connects to the DU 42 via a physical interface 16. The network interface 50 therefore provides acommunication link for data and signalling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

[0047] In case of 5G, the interface 46 between the DU 42 and the CU 40 is known as the F1 interface which can be a physical or a logical interface. The F1 interface 46 between CU and DU may operate in accordance with 3GPP technical specifications [3] and [4], and may be formed from a fibre optic or other wired or wireless high bandwidth connection. In one example the connection 16 from the TRP 10 to the DU 42 is via fibre optic. The connection between a TRP 10 and the core network 20 can be generally referred to as a backhaul, which comprises the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the F1 interface 46 from the DU 42 to the CU 40.

[0048] As will be appreciated by those acquainted with 5G architecture, the CU 40 may be a logical node which hosts Radio Resource Control (RRC) protocols, Service Data Adaptation Protocols (SDAP), and Packet Data Convergence Protocols (PDCP) of a gNB. Alternatively, the CU 40 may be a logical node which hosts RRC and PDCP protocols of an en-gNB (which is a gNB that is able to connect with both EPC and eNBs and can be understood as being, for example, a secondary node (SgNB) used in dual connectivity scenarios). The CU 40 partly controls the operation of one or more DUs 40 and terminates the F1 interface 46 for the DUs that it controls. The DU 42 may be a logical node which hosts Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers of a gNB or en-gNB. The operation of the DU 42 is partly controlled by the CU 40 for which the DU 42 terminates the F1 interface 46. In 5G, the CU 40 may be referred to as a “gNB-CU” and the DU 42 may be referred to as a “gNB-DU”.

[0049] Although not shown in Figures 2 or 3, it will be familiar to those acquainted with 5G architecture that the CU 40 may be further split into a CU-CP which performs the control plane functions of the CU 40 and a CU-UP which performs the user plane functions of the CU 40 (see for example, [5]). In more detail, the CU-CP may be a logical node hosting an RRC protocol and a control plane part of a PDCP protocol of the CU 40 for the gNB or en-gNB. The CU-CP terminates an E1 interface connected with the CU-UP and an F1-C interface connected with the DU 42. As will be appreciated, the F1-C interface carries control plane signalling of the F1 interface 46. The CU-UP may be a logical node which hosts a user plane part of a PDCP protocol of the CU 40 for an en-gNB. Alternatively, the CU-UP may be a logical node which hosts a user plane part of the PDCP protocol and an SDAP protocol of the CU 40 for a gNB. The CU-UP terminates an E1 interface connected with the CU-CP and an F1-U interface connected with the DU 42. As will be appreciated, the F1-U interface carries user plane signalling of the F1 interface 46.

[0050] Random Access (RACH) Procedures

[0051] In wireless communications networks, such as LTE, NR and 6G type networks, a random access procedure may be used by communications devices to perform initial access with the wireless communications network. The random access procedure involves the communications device transmitting a preamble on a physical random access channel (PRACH), and so the procedure is commonly referred to as a RACH or PRACH procedure I process. The RACH procedure may be a two-step RACH procedure or a four-step RACH procedure as described in more detail below.

[0052] In addition, there exists Radio Resource Control (RRC) modes for communications devices. For example, it is common to support an RRC idle mode (RRCJDLE) and an RRC connectedmode (RRC_CONNECTED). A communications device in the RRCJDLE mode may transition to RRC_CONNECTED mode, for example because it needs to transmit uplink data or respond to a paging request, by undertaking a random access procedure.

[0053] In addition to a communications device deciding itself to initiate a random access procedure to connect to the wireless communications network, it is also possible for the wireless communications network, e.g. a base station, to instruct a communications device in an RRC_CONNECTED mode to initiate a random access procedure by transmitting to the communications device an instruction to do so. Such an instruction is sometimes referred to as a PDCCH order (Physical Downlink Control Channel order). There are various scenarios in which a network-triggered RACH procedure (PDCCH order) may arise.

[0054] Figure 4 shows a typical four-step RACH procedure used in LTE systems such as that described by reference to Figure 1 which could also be applied to an NR or 6G wireless communications system such as that described by reference to Figure 2. A communications device (or UE), which may be in an RRCJDLE mode for example, may have some data which it needs to send to the network. To do so, the UE sends a random access preamble 51 (message 1) to a base station. When the base station detects the random access preamble 51, the base station determines a random access preamble index I identity (RAPID) of the random access preamble 51. Assuming the random access preamble 51 is successfully received by the base station, the base station will transmit a random access response 52 message (message 2) to the communications device(s). The random access response 52 message may include the determined RAPID to indicate that the random access response 52 message is for the communications device(s) which transmitted the random access preamble 51 with that RAPID. The random access response 52 message carries a timing advance value such that the communications device can change its UL timing to compensate for the round trip delay caused by its distance from the base station and grant uplink resources for the communications device to transmit the data in.

[0055] Following the reception of the random access response message 52, the communications device transmits the scheduled transmission of data 53 to the base station (message 3), using the identity assigned to it in the random access response message 52. Assuming there are no collisions with other UEs, which may occur if another UE and the communications device send the same random access preamble 51 to the base station at the same time and using the same frequency resources, the scheduled transmission of data 53 is successfully received by the base station. The base station will respond to the scheduled transmission 53 with a contention resolution message 54 (message 4).

[0056] In 5G / NR systems, an “inactive” RRC mode (RRCJNACTIVE) may be used, where a UE is able to start data transfer with a low delay in the RRCJNACTIVE mode without transition to the RRC_CONNECTED mode. In 6G, the “inactive” RRC mode (RRCJNACTIVE) may be used as well. Various possible solutions have been proposed to permit this, one of which is a two-step RACH procedure. As will be appreciated, compared with the four-step RACH process, the two-step RACH process can provide a facility for transmitting data more quickly. Accordingly, it has been proposed to develop general MAC procedures covering both physical layer and higher layer aspects for the two-step RACH process. In general, the benefit of the two-step RACH procedure compared with the four-step RACH procedure is to reduce the time it takes for a connection setup / resume procedure. For example, in an ideal situation, the two-step RACH will reduce the latency by halving the number of steps from four to two for initial access UEs. Inaddition, it is considered that a two-step RACH procedure has potential benefits for channel access in NR unlicensed spectrum (NR-ll) and / or Non-terrestrial networks (NTN).

[0057] Broadly, the two-step RACH allows the combination of the transmission of the random access preamble 51 with the transmission of data 53 of Figure 4 as an initial transmission (“Message A” or “MsgA”), and similarly the combination of the transmission of the random access response 52 and contention resolution message 54 as a response (“Message B”, or “MsgB”). A fallback procedure may be provided to allow a RACH procedure which is started according to the specifications for a two-step RACH to instead proceed according to the four-step RACH procedure. Two-step RACH may be performed by communications devices in the RRCJDLE, RRCJNACTIVE or RRC_CONNECTED modes.

[0058] A message flow diagram illustrating the two-step RACH process is shown in Figure 5. As its name suggests, in the two-step RACH process, there are only two-steps as noted above. In the first step, the UE transmits a Message A 55 which comprises a RACH preamble 56 and data 57. The data 57 is transmitted on a shared uplink channel, such as a physical uplink shared channel, PLISCH that in a four-step RACH procedure would be transmitted in Message 3. More specifically, the choice of a particular preamble 56 may pre-configure the communications device to transmit the data 57 in pre-configured resources of the uplink shared channel. In the second step, the base station, having successfully received the Message A 55, responds with a Message B 58 which incorporates both a RAR, as would be carried by message 2 of the four-step RACH procedure described above, and the corresponding contention resolution and / or data (PDSCH) that in a four-step RACH procedure would be transmitted in Message 4.

[0059] System Information (SI)

[0060] As will be understood by a person skilled in the art, system information (SI) is transmitted by infrastructure equipment of a wireless communications network to communications devices in a cell provided by the infrastructure equipment. The SI informs the communications devices on how to access services provided by the wireless communications network. The SI comprises a master information block (MIB), system information block type 1 (SIB1) and a plurality of other system information blocks (SIBs). The MIB is broadcasted in the PBCH in each SSB.

[0061] The MIB comprises information required to decode SIB1. For example, MIB comprises a cell barred bit, system frame number, and a PDCCH configuration for SIB1, for example. SIB1 comprises information required for performing initial access (for example, random access parameters such as time / frequency resources for PRACH (e.g an RO configuration), preambles, or barring parameters). In initial access, the UE transmits a PRACH in an RO of the RO configuration indicated by SIB1, thereby initiating a random access procedure. After the random access procedure, the UE may enter the RRC_Connected mode. Therefore, MIB and SIB1 together provide all the information which is required for initial access. Accordingly, SIB1 is defined as the “remaining minimum SI”. SIB1 may comprise scheduling information of the other SIBs (for example, mapping of SIBs to SI messages, periodicity of other SIBs and Sl-window size). SIB1 is periodically broadcasted over a downlink shared channel (DL-SCH), but may alternatively be provided on-demand. The information comprised in the other SIBs is not required for initial access and so SIB1 may comprise an indication of whether the other SIBs are provided on-demand, in which case, SIB1 may also comprise an indication of a PRACH configuration for use by the UE to request the other SIBs. SIB1 may also comprise radio resource configuration information common to all communications devices in the cell in which the SIB1 is transmitted. SIB1 may also comprise cell barring information.The other SIBs may comprise one or more of: SIB2-SIB18 and SIBpos.

[0062] Further information regarding existing SI for NR can be found in TS38.300 v18.0.0, the contents of which are hereby incorporated by reference in their entirety. Further information regarding existing SI for LTE can be found in TS 36.331 v18.5.0 and TS36.300 v18.4.0, the contents of which are hereby incorporated by reference in their entirety.

[0063] Non-Terrestrial Networks (NTNs)

[0064] An overview of NR-NTN can be found in [6], a Figures 6 and 7 have been reproduced from that document as a way of background.

[0065] As a result of the wide service coverage capabilities and reduced vulnerability of space / airborne vehicles to physical attacks and natural disasters, Non-Terrestrial Networks are expected to:

[0066] • foster the roll out of 5G service in un-served areas that cannot be covered by terrestrial 5G networks (isolated / remote areas, on board aircrafts or vessels) and underserved areas (e.g. sub-urban / rural areas) to upgrade the performance of limited terrestrial networks in a cost effective manner;

[0067] • reinforce the 5G service reliability by providing service continuity for M2M / loT devices or for passengers on board moving platforms (e.g. passenger vehicles-aircraft, ships, high speed trains, bus) or ensuring service availability anywhere especially for critical communications, future railway / maritime / aeronautical communications; and to

[0068] • enable 5G network scalability by providing efficient multicast / broadcast resources for data delivery towards the network edges or even user terminal.

[0069] The benefits relate to either Non-Terrestrial Networks operating alone or to integrated terrestrial and Non-Terrestrial networks. They will impact at least coverage, user bandwidth, system capacity, service reliability or service availability, energy consumption and connection density. A role for Non-Terrestrial Network components in the 5G system is expected for at least the following verticals: transport, Public Safety, Media and Entertainment, eHealth, Energy, Agriculture, Finance and Automotive. It should also be noted that the same NTN benefits apply to other technologies such as 4G and / or LTE technologies. While 4G, and / or LTE and / or NB-loT are sometimes referred to in the present disclosure, the teachings and techniques presented herein are equally applicable to other technologies such as NR or 5G and beyond such as 6G. Figure 6 illustrates a first example of an NTN architecture based on a satellite / aerial platform with a bent pipe payload, meaning that the signal received from the UE is simply reflected and sent back down to Earth by the satellite / aerial platform, with only frequency or amplification changing; i.e. acting like a pipe with a u-bend. In this example NTN, the satellite or the aerial platform will therefore relay a “satellite friendly” NR (or LTE) signal between the gNodeB (or eNodeB) and UEs in a transparent manner.

[0070] Figure 7 illustrates a second example of an NTN architecture based on a satellite / aerial platform comprising a gNodeB (or eNodeB, for example) which may be referred to as non-terrestrial infrastructure equipment. In this example NTN, the satellite or aerial platform carries a full or part of a gNodeB / eNodeB to generate or receive an NR (or LTE) signal to / from the UEs. For example, in addition to frequency conversion and amplification, the satellite / aerial platform mayalso decode a received signal. This requires the satellite or aerial platform to have sufficient onboard processing capabilities to be able to include a gNodeB or eNodeB functionality.

[0071] Figure 8 schematically shows an example of a wireless communications system 60 which may be configured to operate in accordance with embodiments of the present disclosure. The wireless communications system 60 in this example is based broadly around an LTE-type or 5G-type architecture. Many aspects of the operation of the wireless communications system I network 60 are known and understood and are not described here in detail in the interest of brevity. Operational aspects of the wireless communications system 60 which are not specifically described herein may be implemented in accordance with any known techniques, for example according to the current LTE standards or the current 5G standards.

[0072] The wireless communications system 60 comprises a core network part 65 (which may be a 4G core network or a 5G core network) in communicative connection with a radio network part. The radio network part comprises a base station (gNode B) 61 connected to a non-terrestrial network part 64. The non-terrestrial network part 64 may be an example of infrastructure equipment. Alternatively, or in addition, the non-terrestrial network part 64 may be mounted on a satellite vehicle or on an airborne vehicle.

[0073] The non-terrestrial network part 64 may communicate with a communications device 63, located within a cell 66, by means of a wireless access interface provided by a wireless communications link 67a. For example, the cell 66 may correspond to the coverage area of a spot beam generated by the non-terrestrial network part 64. The boundary of the cell 66 may depend on an altitude of the non-terrestrial network part 64 and a configuration of one or more antennas of the non-terrestrial network part 64 by which the non-terrestrial network part 64 transmits and receives signals on the wireless access interface.

[0074] The non-terrestrial network part 64 may be a satellite in an orbit with respect to the Earth, or may be mounted on such a satellite. For example, the satellite may be in a geo-stationary Earth orbit (GEO) such that the non-terrestrial network part 64 does not move with respect to a fixed point on the Earth’s surface. The geo-stationary Earth orbit may be approximately 36,786km above the Earth’s equator. The satellite may alternatively be in a low-Earth orbit (LEO), in which the non-terrestrial network part 64 may complete an orbit of the Earth relatively quickly, thus providing moving cell coverage. Alternatively, the satellite may be in a non-geostationary orbit (NGSO), so that the non-terrestrial network part 64 moves with respect to a fixed point on the Earth’s surface. The non-terrestrial network part 64 may be an airborne vehicle such as an aircraft, or may be mounted on such a vehicle. The airborne vehicle (and hence the nonterrestrial network part 64) may be stationary with respect to the surface of the Earth or may move with respect to the surface of the Earth.

[0075] In Figure 8, the terrestrial station 61 is shown as ground-based, and connected to the nonterrestrial network part 64 by means of a wireless communications (feeder) link 67b. The nonterrestrial network part 64 receives signals representing downlink data transmitted by the base station 61 on the wireless communications link 67b and, based on the received signals, transmits signals representing the downlink data via the wireless communications (service) link 67a providing the wireless access interface for the communications device 63. Similarly, the non-terrestrial network part 64 receives signals representing uplink data transmitted by the communications device 63 via the wireless access interface comprising the wireless communications link 67a and transmits signals representing the uplink data to the terrestrialstation 61 on the wireless communications link 67b. The wireless communications links 67a, 67b may operate at a same frequency, or may operate at different frequencies.

[0076] The extent to which the non-terrestrial network part 64 processes the received signals may depend upon a processing capability of the non-terrestrial network part 64. For example, the non-terrestrial network part 64 may receive signals representing the downlink data on the wireless communication link 67b, amplify them and (if needed) re-modulate onto an appropriate carrier frequency for onwards transmission on the wireless access interface provided by the wireless communications link 67a. Alternatively, the non-terrestrial network part 64 may be configured to decode the signals representing the downlink data received on the wireless communication link 67b into un-encoded downlink data, re-encode the downlink data and modulate the encoded downlink data onto the appropriate carrier frequency for onwards transmission on the wireless access interface provided by the wireless communications link 67a.

[0077] The non-terrestrial network part 64 may be configured to perform some of the functionality conventionally carried out by a base station (e.g. a gNodeB or an eNodeB), such as base station 1 as shown in Figure 1. In particular, latency-sensitive functionality (such as acknowledging a receipt of the uplink data, or responding to a RACH request) may be performed by the non-terrestrial network part 64 partially implementing some of the functions of a base station.

[0078] As mentioned above, a base station may be co-located with the non-terrestrial network part 64; for example, both may be mounted on the same satellite vehicle or airborne vehicle, and there may be a wireless connection providing the coupling between the terrestrial station 61 and the base station co-located on the non-terrestrial network part 64. In such co-located arrangements, a wireless communications feeder link between the terrestrial station 61 and another terrestrial station (not shown) may provide connectivity between the terrestrial station 61 (co-located with the non-terrestrial network part 64) and the core network part 65.

[0079] The terrestrial station 61 may be an NTN Gateway that is configured to transmit signals to the non-terrestrial network part 64 via the wireless communications (feeder) link 67b and to communicate with the core network part 65. That is, in some examples the terrestrial station 61 may not include base station functionality. For example, if the base station is co-located with the non-terrestrial network part 64, as described above, the terrestrial station 61 does not implement base station functionality. In other examples, the base station may be co-located with the NTN Gateway in the terrestrial station 61, such that the terrestrial station 61 is capable of performing base station (e.g. gNodeB or eNodeB) functionality.

[0080] In some examples, even if the base station is not co-located with the non-terrestrial network part 64 (such that the base station functionality is implemented by a ground-based component), the terrestrial station 61 may not necessarily implement the base station functionality. In other words, the base station (e.g. gNodeB or eNodeB) may not be co-located with the terrestrial station 61 (NTN Gateway). In this manner, the terrestrial station 61 (NTN Gateway) transmits signals received from the non-terrestrial network part 64 to a base station (not shown in Figure 8). In such an example, the base station (e.g. gNodeB or eNodeB) may be considered as being part of core network part 65, or may be separate (not shown in Figure 8) from the core network part 65 and located logically between the terrestrial station 61 (NTN Gateway) and the core network part 65.In some cases, the communications device 63 shown in Figure 8 may be configured to act as a relay node. That is, it may provide connectivity to one or more terminal devices such as the terminal device 62. When acting as a relay node, the communications device 63 transmits and receives data to and from the terminal device 62, and relays it, via the non-terrestrial network part 64 to the terrestrial station 61. The communications device 63, acting as a relay node, may thus provide connectivity to the core network part 65 for terminal devices which are within a transmission range of the communications device 63.

[0081] In some cases, the non-terrestrial network part 64 is also connected to a ground station 68 via a wireless link 67c. The ground station may for example be operated by the satellite operator (which may be the same as the mobile operator for the core and / or radio network or may be a different operator) and the link 67c may be used as a management link and / or to exchange control information. In some cases, once the non-terrestrial network part 64 has identified its current position and velocity, it can send position and velocity information to the ground station 68. The position and velocity information may be shared as appropriate, e.g. with one or more of the UE 63, terrestrial station 61 and base station, for configuring the wireless communication accordingly (e.g. via links 67a and / or 67b). Furthermore, in some cases, the radio network may itself calculate the location of the non-terrestrial network part 64, for example based on ephemeris information of the non-terrestrial network part 64.

[0082] It will be apparent to those skilled in the art that many scenarios can be envisaged in which the combination of the communications device 63 and the non-terrestrial network part 64 can provide enhanced service to end users. For example, the communications device 63 may be mounted on a passenger vehicle such as a bus or train which travels through rural areas where coverage by terrestrial base stations may be limited. Terminal devices on the vehicle may obtain service via the communications device 63 acting as a relay, which communicates with the non-terrestrial network part 64.

[0083] Support of PWS in LTE and loT NTN

[0084] As will be appreciated by a person skilled in the art, a Public Warning System (PWS) is used to inform the public about warnings in potential emergency situations. Examples of a PWS include an Earthquake and Tsunami Warning System (ETWS) and Commercial Mobile Alert Service (CMAS).

[0085] In RAN#106, the latest Work Item Description (WID) for loT NTN Phase 3 ([7]) provides an update for supporting PWS for loT NTN. In particular, it is intended to support the broadcast of PWS messages for NB-loT re-using LTE mechanisms. If possible, the solutions developed for NTN should be applicable to terrestrial networks. However, specific NB-loT optimisations have not yet been considered.

[0086] LTE (also referred to as E-UTRAN) mechanisms for PWS are described briefly below. Further information can be found in [8] the contents of which are hereby incorporated by reference in their entirety.

[0087] When the public is to be notified of a public warning, the E-UTRAN performs scheduling and broadcasting of a PWS message comprising content of the public warning. The content of the PWS message is received from a CBC (cell broadcast centre) and forwarded to the E-UTRAN by an MME. The CBC can also indicate some requirements relating to the timely delivery of thePWS messages. For example, the CBC may send the following information to the MME which may be forwarded by the MME to the E-UTRAN: a “repetition period” and “number of broadcasts requested”. The E-UTRAN then performs scheduling of the PWS message (for example, the E-UTRAN schedules the PWS message to be broadcast with a particular periodicity). To inform UEs that the PWS message is being broadcast, the E-UTRAN transmits a paging signal to UEs. The paging signal comprises a PWS message type indication which indicates a type of PWS message being broadcast by the E-UTRAN (e.g. an etws-indication or cmas indication as explained in more detail below). Depending on the size of the public warning to be notified, the E-UTRAN may segment the content of the PWS message and transmit the content over a plurality of smaller messages / segmented messages.

[0088] ETWS ETWS is a PWS developed to meet regulatory requirements for warning notifications related to earthquake and / or tsunami events. An ETWS message comprising content of a public warning may be a primary notification (short notifications delivered within 4 seconds (see [9], the contents of which are hereby incorporated by reference in their entirety)) or a secondary notification (providing more detailed information). In LTE I NB-loT, the primary notification is broadcast in SystemlnformationBlockTypelO (SIB10) and the secondary notification is broadcast in SystemlnformationBlockTypel 1 (SIB11). It is possible to transmit two ETWS messages, one which is a primary notification and another which is a secondary notification. In NR, the primary notification is comprised in SIB6 and the secondary notification is comprised in SIB7.

[0089] CMAS CMAS is a PWS developed for delivering multiple, concurrent warning notifications (see

[0010] , the contents of which are hereby incorporated by reference in their entirety). The CMAS messages are short text messages (CMAS alerts). In LTE I NB-loT, the CMAS messages are broadcast in SystemlnformationBlockType12 (SIB12). The E-UTRAN manages the delivery of multiple, concurrent CMAS warning notifications to UEs and is also responsible for handling any updates of CMAS messages. SIB12 may also comprise geographical information of the CMAS message indicating a geographical area for which the CMAS messages is intended.

[0090] In NR, the CMAS message is comprised in SIB8. SIB8 may also comprise geographical information of the CMAS message indicating a geographical area for which the CMAS messages is intended.

[0091] Further information regarding SIB10, SIB11 and SIB12 for LTE / NB-loT can be found in

[0011] and TS36.300 v18.4.0, the contents of which are hereby incorporated by reference in their entirety.

[0092] Although example embodiments may be described below with reference to SIB10, SIB11 and SIB12, this is for ease of explanation only and it will be appreciated that the present disclosure also applies to NR, and any other wireless radio communications standard. As such, embodiments described below with reference to SIB12 are not restricted to SIB12 as defined in LTE but apply more generally to any system information comprising a CMAS message (such as SIB8 in NR). Embodiments described below with reference to SIB10 are not restricted to SIB10as defined in LTE but apply more generally to any system information comprising an ETWS primary notification (such as SIB6 in NR). Embodiments described below with reference to SIB11 are not restricted to SIB11 as defined in LTE but apply more generally to any system information comprising an ETWS secondary notification (such as SIB7 in NR).

[0093] loT NTN

[0094] It has been agreed to extend existing ETWS / CMAS notification RRC procedures for eMTC to NB-loT. The procedure for existing eMTC devices is as follows:

[0095] — A paging signal is transmitted by the network to eMTC devices in RRC idle mode. The paging signal comprises a PWS message type indication indicating a type of a PWS message being broadcast. For example, the PWS type indication may be an “etws- indication" indicating that a ETWS message is being broadcast or a “cmas-indication” indicating that a CMAS message is being broadcast.

[0096] — In response to receiving the paging signal, the eMTC devices immediately acquire SIB1 without waiting for the next SI modification boundary.

[0097] — SIB1 comprises scheduling information (e.g. “schedulinglnfoList”) comprising a schedule according to which a PWS message is being transmitted. When the PWS message type indication is an etws-indication, the scheduling information indicates a schedule of SIB10 and / or SI B11. The schedule of SIB10 is indicated when an ETWS message which is a primary notification is being broadcast. The schedule of SIB11 is indicated when an ETWS message which is a secondary notification is being broadcast. When the PWS message type indication is a cmas-indication, the scheduling information indicates a schedule of SIB12.

[0098] — The eMTC devices then acquire the SIB indicated by the scheduling information. When the PWS message type indication is an etws-indication, the eMTC devices acquire SIB10 or SIB11 to obtain the ETWS message(s). When the PWS message type indication is a cmas-indication, the eMTC devices acquire SIB12 to obtain the CMAS message.

[0099] Implementation of PWS for NB-loT devices creates technical issues. For example, RRC Connected NB-loT devices are not required to simultaneously monitor for a paging signal and data transmission. In other words, a UE configured as an NB-loT device is not required to simultaneously monitor an (N)PDCCH UE-specific search space (USS) and a Type-1 (N)PDCCH common search space (CSS). RRC Connected NB-loT devices are expected to only monitor (N)PDCCH UE-specific search space. Further detail can be found in

[0012] , the contents of which are hereby incorporated by reference in their entirety.

[0100] Therefore, for an NB-loT device with ongoing data / voice transmissions, the NB-loT device may miss a paging signal comprising a PWS message type indication (such as an etws-indication or cmas-indication) because reception of the paging signal would require the NB-loT device to monitor Type-1 NPDCCH common search space. Thus the NB-loT device is not aware that there is a PWS message being broadcast.

[0101] Existing mechanisms for enabling an NB-loT device to receive the paging signal involve infrastructure equipment of a wireless communications network transmitting an RRC release message to all devices in a cell provided by the infrastructure equipment. This allows the devices in that cell to switch to monitoring the Type-1 NPDCCH common search space toreceive the paging signal. However, in response to receiving the RRC release message, the devices release their RRC connection, thus causing any ongoing voice / data communications with that device to be dropped. This leads to the interruption of communications and communications resource wastage. The interruption of communications can be particularly problematic when the communications are interrupted for reasons that are not of concern to the communicating user, e.g. low priority public announcement.

[0102] It has been proposed (

[0013] ) to introduce a new MAC CE comprising a PWS message type indication (such as etws-indication or cmas-indicatiori). In response to receiving the MAC CE, SIB1 is read for scheduling information of a PWS message that is being broadcast. Then the PWS message is obtained by receiving the corresponding SIB (e.g. SIB10, SIB11, orSIB12). Since a MAC CE can be received at the same time as an on-going data / voice transmission, NB-loT devices do not have to monitor both NPDCCH UE-specific search space and a Type-1 NPDCCH common search space simultaneously. Therefore, an RRC connected NB-loT device can receive a PWS message type indication without monitoring for a paging signal.

[0103] The present inventors have recognised that this 3-step approach (receiving a MAC CE, acquiring SIB1 and acquiring SIB10, SIB 11 and / or SIB12) can lead to undesirable latency in the reception of PWS messages by communications devices. Such latency is particularly undesirable when the PWS messages relate to an emergency scenario (e.g. an earthquake or tsunami). Furthermore, the present inventors have noted that the CMAS message in SIB12 comprises warning area co-ordinates of the geographical area where the CMAS message is valid. However, in order for a UE to determine whether or not a CMAS message is valid for it, the communications device must go through the 3-step procedure (receiving a MAC CE, acquiring SIB1 and acquiring SIB12). Additionally, the communications device may have transitioned to an RRC idle or RRC inactive mode (if it receives an RRC release message) to receive the CMAS message and thus dropped data transmissions with the infrastructure equipment. Despite this the communications device, may determine that the CMAS message is not valid for it. Accordingly, the communications device has inefficiently used power and may have dropped data transmissions.

[0104] There is therefore a need for improved communications devices, infrastructure equipment and methods which address at least some of the above issues.

[0105] In accordance with example embodiments, there is provided a method of operating a communications device as illustrated in Figure 9.

[0106] The method starts in step S1.

[0107] In step S2, the method comprises receiving a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network.

[0108] The communications device may be a UE. The UE may be an NB-loT device, or cellular device (such as a smartphone) configured in accordance with LTE or NR specifications, for example. The infrastructure equipment of the wireless communications network may be base station such as a gNB, for example.

[0109] The PWS signal comprises one or more of:i) a PWS message comprising content of a public warning,

[0110] ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, or

[0111] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended.

[0112] In other words, the PWS signal may comprise any of the following combinations:

[0113] 1. i), or

[0114] 2. ii), or

[0115] 3. iii), or

[0116] 4. i) and ii), or

[0117] 5. i) and iii), or

[0118] 6. ii) and iii), or

[0119] 7. i), ii) and iii)

[0120] The PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0121] The public warning may be a warning regarding an earthquake or tsunami for example. The PWS signal may be broadcast by the infrastructure equipment.

[0122] The method ends in step S3.

[0123] Although reference is made throughout this disclosure to “a PWS message”, it should be understood that this includes reference to “one or more PWS messages”. For example, there may be a plurality of PWS messages where one of the PWS messages is an ETWS message comprising a primary notification and another one of the PWS messages is an ETWS message comprising a secondary notification or any other warning messages, for example regarding extreme weather, pollen level, ultraviolet level etc.

[0124] It will be appreciated that the word “signal” in the present disclosure is used in the broad sense to mean a transmission which conveys information. Accordingly, the words “signal” and “transmission” are interchangeable in this disclosure. The term “signal” should be not construed as requiring that the transmission is associated with a particular protocol layer, unless otherwise specified or implied by the context in which the signal is discussed.

[0125] In the case of i), the PWS message is transmitted in a MAC signal, RRC signal or paging signal. By transmitting the PWS message in a MAC signal, RRC signal or paging signal, the communications device can receive the PWS message more quickly than in existing approaches. For example, there is no need for the communications device to first receive a PWS message type indication (in a paging signal or MAC CE), read SIB1 to obtain scheduling information of the PWS message and obtain the PWS message from the SIB indicated in SIB1.Furthermore, since fewer signals need to be decoded to obtain the PWS message, sources of decoding errors are reduced and thus reliability increases.

[0126] In the case of ii), scheduling information is transmitted in a MAC signal, RRC signal or paging signal. In some embodiments, the scheduling information comprises the first schedule. By transmitting the first schedule in a MAC signal, RRC signal or paging signal, the communications device can receive the PWS message more quickly than in existing approaches. For example, there is no need for the communications device to first receive a PWS type message indication (in a paging signal or MAC CE) and read SIB1 to obtain scheduling information of the PWS message. Furthermore, since fewer signals need to be decoded to obtain the PWS message, sources of decoding errors are reduced and thus reliability increases. For example, in some embodiments, the communications device performs the following steps:

[0127] — The communications device receives the PWS signal comprising the first schedule according to which the PWS message is transmitted by the infrastructure equipment (the first schedule may be a schedule according to which SIB10 and / or SIB11 is transmitted if the PWS message is an ETWS message or a schedule according to which SIB12 is transmitted if the PWS message is a CMAS message); and

[0128] — The communications device receives the PWS message according to the first schedule (for example, the communications device acquires SIB10 and / or SIB11 when the PWS message is an ETWS message or acquires SIB12 when the PWS message is a CMAS message).

[0129] In some embodiments, the scheduling information comprises the second schedule. By transmitting the second schedule in a MAC signal, RRC signal or paging signal, the communications device can monitor a time window for the downlink transmission which may comprise the first schedule or the third schedule. The time window may be determined by the infrastructure equipment of the wireless communications network, for example. The time window may be determined based on the scheduling information of the PWS - e.g. the time window is determined so as to include the PWS message. This is improved over existing approaches where the communications device acquires SIB1 in response to receiving a PWS message type indication (in a paging signal or MAC CE) by reducing the amount of time required for the communications device to determine the first schedule. For example, in some embodiments, the communications device performs the following steps:

[0130] — The communications device receives the PWS signal comprising the second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment (e.g. the time window may be a time window which the communications device should monitor for a PDCCH such as a narrowband PDCCH ((N)PDCCH)). A DCI may be comprised in the PDCCH and the DCI may comprise the first schedule or the third schedule. For example, the first schedule may be a schedule according to which SIB10 and / or SIB11 is transmitted when the PWS message is an ETWS message or a schedule according to which SIB12 is transmitted when the PWS message is a CMAS message. In particular, the first schedule may indicate a schedule for a PDSCH(s) which carries SIB10 and / or SIB11 when the PWS message is an ETWS message or SIB12 when the PWS message is a CMAS message. The third schedule may be a schedule according to which another downlink transmission (such as a PDSCH) comprising the first schedule is transmitted;— The downlink transmission comprising the first schedule or the third schedule (e.g. a PDCCH comprising a DCI) is received by the communications device during the time window;

[0131] — The communications device receives the PWS message according to the first schedule (for example, the communications device acquires SIB10 and / or SIB11 when the PWS message is an ETWS message or acquires SIB12 when the PWS message is a CMAS message).

[0132] In the case of iii), the communications device may determine not to receive the PWS message based on the geographical information and thus avoid unnecessary signaling. For example, the communications device may determine that its location is outside the geographical area for which the PWS message is intended and determines not to receive the PWS message in response. Since the geographical information is transmitted in a MAC signal, RRC signal or paging signal, the geographical information can be made available to the communications device earlier than in existing approaches where the geographical area is indicated in the SIB12 along with the CMAS message after the communications device has received a PWS message type indication (in a paging signal or MAC CE), read SIB1 to obtain scheduling information of the CMAS message and obtained the CMAS message and geographical information from SIB12. For example, the communications device may determine not to read SIB1 for scheduling information (such as scheduling InfoList) in response to determining that the communications device is outside the geographical area for which the PWS message is intended. Thus, the communications device does not need to receive SIB1 and also the communications device does not need to receive SIB10 and / or SIB11 when the PWS message is an ETWS message or receive SIB12 when the PWS message is a CMAS message. Furthermore, such embodiments may improve energy consumption of the communications device and help avoid service interruption to devices outside the intended geographical area (service interruption may occur due to an RRC release message being received as previously explained).

[0133] In some embodiments, the communications device may determine its location. For example, the communications device may use an in-built GPS, or the location of the communications device may be indicated to the communications device by the infrastructure equipment, for example. In some embodiments, the geographic information further comprises an instruction to the communications device to not receive the scheduling information and / or the PWS message. The instruction may include an instruction not to drop a data transmission (e.g. voice call) from the infrastructure equipment.

[0134] In some embodiments, the PWS signal is a MAC signal or an RRC signal. Such embodiments are particularly advantageous when the communications device receiving the PWS signal is in an RRC connected mode and the communications device is not capable of simultaneously receiving a data transmission and a paging signal (such as an NB-loT device). The communications device is able to receive a MAC signal or RRC signal even when there is an on-going data transmission with the communications device. In embodiments where the PWS signal is an RRC signal, the PWS signal may be an RRC reconfiguration message or RRC release message, for example. The RRC reconfiguration message or RRC release message may comprise an information element comprising any one of combinations 1-7).

[0135] In some embodiments, the PWS signal is a paging signal. Such embodiments are particularly advantageous when the communications device receiving the PWS signal is in an RRC idlemode or an RRC inactive mode. The PWS message, scheduling information and / or geographical information may be “piggybacked” onto a paging signal, thus increasing communications efficiency.

[0136] In any of combinations 1-7, the PWS signal may additionally comprise a PWS message type indication such as an etws-indication or a cmas-indication, or a more detailed indication of the type of public warning such as that the warning relates to a flood.

[0137] Figure 10 schematically illustrates a MAC CE design in accordance with example embodiments. In particular, Figure 10 illustrates a MAC CE comprising N1, N2 and scheduling information. N1 represents an etws-indication and N2 represents a cmas-indication. The scheduling information in this example is scheduling information indicating the first schedule according to which the PWS message is transmitted by the infrastructure equipment. In particular, the first schedule indicates a periodicity with which PWS message comprised in the SI is transmitted. The SI may be SIB10 and / or SIB11 when the PWS message is an ETWS message or the SI may be SIB12 when the PWS message is a CMAS message. Examples of periodicity of the SI which may be indicated in the scheduling information include:

[0138] 001 : rf8

[0139] 010: rf16

[0140] 011: rf32

[0141] 100: rf64

[0142] 101: rf128

[0143] 110: rf256

[0144] 111: rf512

[0145] The unit of periodicity is in radio frames (rf) in this example. In this example, three bits of Octi are used to indicate the scheduling information. One bit of Octi is used to indicate the presence or absence of an etws indication (N1) and one bit is used to indicate the presence or absence of a cmas indication. The unused 3 bits may be reserved for future use.

[0146] In some embodiments, either alternatively or in addition to the periodicity, the first schedule comprised in the scheduling information indicates a radio frame at which the PWS message comprised in the SI is transmitted. The scheduling information may comprise an identification of the radio frame at which the SI comprising PWS message is transmitted or may indicate the radio frame by indicating an offset of the radio frame relative to a radio frame known by the communications device. The combination of signalling the offset and the periodicity allows the PWS message comprised in the SI to be inserted at any time location in the SI. This has the advantage that the communications device does not have to acquire SIB1 because the device directly reads SIB (e.g. SIB10, SIB11 orSIB12) containing the PWS message.

[0147] Figure 11 schematically illustrates a MAC CE design in accordance with example embodiments. Figure 11 is based on the MAC CE design in Figure 10 but the MAC CE in Figure 10 additionally comprises geographical information. Only the differences between Figure 10 and Figure 11 will be described for brevity. In the example of Figure 11 , the geographical information comprises warning area co-ordinates indicated by Oct2 which comprises 8 bits, although it will be appreciated that more or fewer bits may be used to indicate the warning area co-ordinates.In some embodiments, the PWS signal comprises a PWS message type indication in addition to the scheduling information. The PWS message type indication indicates a type of the PWS message to be transmitted by the infrastructure equipment. In some embodiments, the PWS message type indication indicates a type of the public warning (i.e. the type of PWS message is a type of the public warning of which the PWS message comprises content). For example, the PWS message type indication may indicate that the PWS message is for an earthquake. In another example the PWS message type indication may indicate that the PWS message is for a tsunami.

[0148] In some embodiments, the infrastructure equipment determines whether to transmit the scheduling information along with the PWS message type indication in the MAC signal based on the PWS message type. For example, if the PWS message type represents an immediate emergency (such as an ongoing or imminent earthquake), the scheduling information is transmitted along with the PWS message type indication so that the scheduling information is received as quickly as possible. In another example, if the PWS message type represents a less immediate emergency (such as an incoming tsunamic that has not yet reached land) the scheduling information may be sent after the PWS message type indication. This enables the MAC header size to be reduced. In this case, the scheduling information may be included in SIB1 as in existing approaches.

[0149] In some embodiments, the communications device determines, based on the type of the PWS message, whether or not to drop on an-going data transmission with the infrastructure equipment to receive the PWS message. For example, if the PWS relates to a non-urgent or serious warning (e.g, a warning to wear sun cream due to slightly higher than normal temperatures), the communications device may determine not to drop an on-going data transmission with the infrastructure equipment. For example, of the reception of the PWS message would require the communications device to transition to an RRC idle or RRC inactive mode and thus drop the on-going data transmission, the communications device can determine not to perform the reception.

[0150] In some embodiments, the communications device transmits a preference indication to the infrastructure equipment indicating one or more preferred PWS message types which the communications device wishes to receive. Such preferred PWS message types may be message types for which the communications device is willing to drop an on-going data transmission with the infrastructure equipment. In such embodiments, the infrastructure equipment may only transmit an RRC release message device to transition the communications device to the RRC idle or RRC inactive mode when the type of the PWS message is one of the preferred types. For example, the infrastructure equipment may determine to not transmit an RRC release message to the communications device to transition the communications device to the RRC idle or RRC inactive mode in order to receive the PWS message. Alternatively, or additionally to indicating one or more preferred types of PWS message, the communications device may transmit a preference indication indicating one or more non-preferred types of PWS message. Such non-preferred PWS message types may be message types for which the communications device is not willing to drop an on-going data transmission with the infrastructure equipment. In such embodiments, the infrastructure equipment may only transmit RRC release message to the communications device when the type of the PWS message is not one of the non-preferred types. The RRC release message may be the PWS signal.In some embodiments, the PWS message type indication indicates one of a plurality of codebook entries each corresponding to a different type of PWS message. In a particular, example each of the plurality of codebook entries corresponds to a different type of public warning. For example, there may be a code-point of four possible warnings: 1. Earthquake, 2. Tsunami, 3. Volcano and 4. Flood. By indicating code-point 4, the PWS message type indication can indicate that a PWS message comprising a flood warning is being transmitted. By providing an early indication of the flood in the PWS message type indication, users can evacuate the affected area. Detailed information (i.e. the content of) the flood warning is comprised in the PWS message which may be sent later in SI, for example. The PWS message may specify a valley to which the flood applies and the severity of the flooding. In an NTN system (such as a GEO system) it is advantageous to expedite the transmission of the PWS message type indication comprising an indication of the type of public warning due to the latency caused by the round trip time.

[0151] In some embodiments, the PWS message type indication indicates one of a plurality of code points in a MAC CE of the MAC signal each corresponding to a different type of PWS message. In a particular, example each of the plurality of code points corresponds to a different type of public warning. For example, a MAC CE that occupies 4 bits but can only indicate one of 10 legacy messages can be reused by using the 11th, 12th, 13th and 14th code-points to indicate earthquake, tsunami, volcano or flood respectively.

[0152] In some embodiments, the type of PWS message is indicated by one or more unused or reserved bit of a MACE CE. In such embodiments, the number of bits available for the indication may be limited. Thus, for example, the one or more unused or reserved bits may indicate an “etws-indication" or “cmas-indication".

[0153] In some embodiments, as explained above, the PWS signal may comprise the scheduling information and the PWS message (combination 4). In particular, the PWS signal may comprise the first schedule according to which the PWS message is transmitted and the PWS message. For example, a MAC CE of a MAC signal may comprise the first schedule and, in this case, the first schedule indicates that the PWS message is transmitted in a MAC PDU of the MAC signal. In such embodiments, the communications device may read the MAC CE, determine that the PWS message is in the MAC PDU, and then read the MAC PDU to obtain the PWS message. The MAC signal may be sent in a PDSCH, for example, and thus the first schedule and the PWS message may be sent in the same PDSCH. Such embodiments where the scheduling information and the PWS message are sent in the same PWS signal can reduce the number of signals transmitted and thus reduce network load and improve communications efficiency. In an example, there may be one or more communications devices in a cell in an RRC connected mode which are receiving data transmissions in the form of voice calls. The communications resources being used for sending the data transmissions to the one or more communications devices can be re-purposed and used instead for transmitting the MAC signal to the one or more communications devices.

[0154] In some embodiments, the MAC CE or the MAC PDU of a MAC signal comprises the scheduling information.

[0155] In some embodiments, when the scheduling information comprises the first schedule according to which the PWS message is transmitted, the first schedule indicates communications resources (e.g. time and frequency resources) used for transmitting the PWS message. ThePWS message may be comprised in a PDSCH. In such embodiments, the first schedule may indicate communications resources of the PDSCH in which the PWS message is comprised. In some embodiments, the first schedule indicates a transport block size (TBS) of the PWS message.

[0156] As explained above, in some embodiments, the PWS signal may comprise the second schedule indicating a time window which the communications device should monitor for reception of the downlink transmission comprising the first schedule or the third schedule from the infrastructure equipment. The second schedule may be comprised in a MAC CE or MAC PDU for example. The time window may be a time window which the communications device should monitor for a PDCCH (such as an (N)PDCCH). A DCI may be comprised in the PDCCH and the DCI may comprise the first schedule or the third schedule. The first schedule may indicate a schedule according to which SI comprising the PWS message is transmitted. The third schedule may indicate a schedule according to which a PDSCH comprising the first schedule is transmitted. In some embodiments, the PDCCH carrying the DCI comprises a plurality of repetitions. By indicating a time window during which the communications should monitor for PDCCH, the time taken to decode PDCCH can be reduced.

[0157] RRC Release Cause Value

[0158] In existing systems, when the infrastructure equipment of the wireless communications network intends to transmit a PWS message, the infrastructure equipment first transmits an RRC release message to cause the communications device to transition from an RRC connected mode to an RRC idle mode or an RRC inactive mode. This transition causes the communications device to drop any ongoing data transmission with the infrastructure equipment such as a voice call. In some cases, the communications device can receive in parallel in a CSS (common search space) and a USS (UE specific search space). However, the communications device in RRC connected mode may be using a Bandwidth Part (BWP) or narrowband carrier for communication on which the infrastructure equipment is unable to transmit the PWS message. Therefore, the communications device cannot receive the PWS message while in the RRC connected mode while an ongoing data transmission with the infrastructure equipment is occurring. Accordingly, in such cases, an RRC release message still needs to be transmitted to the communications device before the PWS message can be received.

[0159] In accordance with example embodiments, there is provided a method of operating a communications device as illustrated in Figure 12. The method starts in step S11.

[0160] In step S12, the method comprises receiving a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network. The RRC release message comprises an instruction to receive a PWS message.

[0161] In step S14, the method comprises transitioning from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message.

[0162] In step S16, the method comprises receiving the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

[0163] The method ends in step S18.By including an instruction in the RRC release message, the infrastructure equipment can enable a communications device to receive a PWS more quickly than in existing systems. This is particularly advantageous when the PWS message is particularly important or represents an immediate emergency,

[0164] For example, the infrastructure equipment may determine that the type of PWS message is for an on-going or imminent earthquake and is thus an emergency scenario. Therefore, the infrastructure equipment transmits the RRC release message comprising the instruction to receive the PWS message.

[0165] In some embodiments, the communications device may transmit a preference indication to the infrastructure equipment. The preference indication indicates one or more preferred types of PWS message which the communications device wishes to receive. In such embodiments, the infrastructure equipment may only transmit the RRC release message when the type of the PWS message is one of the preferred types. For example, the infrastructure equipment may only transmit the RRC release message when the PWS message is an ETWS message or the infrastructure equipment may only transmit the RRC release message when the PWS message is a CMAS message. Alternatively, or in addition, the communications device may transmit a preference indication indicating one or more non-preferred types of PWS message which the communications device does not wish to receive. In such embodiments, the infrastructure equipment may only transmit the RRC release message when the type of the PWS message is not one of the non-preferred types.

[0166] In some embodiments, the instruction is comprised in a releaseCause of an RRC release message. In some embodiments, a spare bit in the releaseCause for NB-loT can be used to provide the instruction. In some embodiments, the existing releaseCause IE in

[0011] (applicable to smartphones in LTE) may be extended to include the instruction. In some embodiments, the instruction may be comprised in a separate information element of the RRC release message.

[0167] In response to receiving the instruction, the communications device may directly monitor for PWS messages (by either reading paging messages or directly reading the SIBs related to PWS) instead of adopting the legacy procedure of monitoring paging channels according to the communications device’s DRX cycle and then only decoding PWS messages if receiving a suitable paging notification.

[0168] In existing systems, infrastructure equipment of a wireless communications network configures a plurality of paging occasions which the communications device can monitor for a paging signal. The communications device only monitors a subset of the paging occasions. For example, the communications device may monitor the paging occasions in accordance with a DRX cycle of the communications device. For example, if a communications device has a DRX cycle set to 8, then the communications device may only monitor every 8thpaging occasion for a paging signal. In accordance with example embodiments, the communications device may monitor the paging occasions at a higher rate than the DRX cycle configured for the communications device. In some embodiments, the communications device may monitor every paging occasion configured for the communications device until the paging signal is received. Specifically, the communications device monitors a first available one of the paging occasions after the communications device transitions to the RRC idle mode or RRC inactive mode and each subsequent paging occasion is monitored until the paging signal is received. In exampleembodiments, the paging signal may be a paging signal comprising a PWS message type indication. In some embodiments, the paging signal may be a paging signal comprising one or more of i), ii) or iii).

[0169] In some embodiments, in response to the instruction, the method comprises monitoring one or more system information blocks for the PWS message. E.g. the communications directly proceeds to monitoring SIB10, SIB11 and / or SIB12. After transitioning to the RRC idle mode or the RRC inactive mode.

[0170] In some embodiments, the method comprises, after receiving the RRC release message or after transitioning to the RRC idle mode or RRC inactive mode, starting a timer upon expiry of which the communications device is configured to re-enter the RRC connected mode if the PWS message has not been received. The method may further comprise determining, based on the instruction, to not re-enter the RRC connected mode until the PWS message has been received, or until the timer expires. In some embodiments, the communications device may determine not to enter the RRC connected mode even if the timer expires before the PWS message has been received, thus giving the communications device more time to receive the PWS message. In some embodiments, the instruction may be included in RRC release messages for one or more selected communications devices and / or one or more selected PWS message types. Therefore, for non-selected communications devices and / or selected PWS message types, if the communications device has not received the PWS message by the time this timer has expired, then the communications device transitions back to the RRC connected mode. The communications device may then proceed to restart the voice call.

[0171] However, the present inventors have recognised that in existing systems a relatively large amount of time is required for the communications device to receive the PWS message since it first receives a paging signal, followed by reading SIB1 for scheduling information, followed by reading SIB 10 and / or 11 for an ETWS message or reading SIB12 for a CMAS message.

[0172] Therefore, it may happen that there is an important and / or urgent PWS message which the communications device does not receive before the timer expires. By including an instruction in the RRC release message for selected communications devices and / or selected PWS message types, the communications device would be prevented from re-entering the RRC connected mode and re-starting the voice call and thus the communications device would be able to read the PWS message. This ensures that important and / or urgent PWS messages are not missed. The method described with reference to Figure 12 may be combined with the method described with reference to Figure 9. For example, steps S12 to S14 may precede step S2.

[0173] The following numbered paragraphs provide further example aspects and features of the present technique:

[0174] Paragraph 1. A method of operating a communications device, the method comprising receiving a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network, the PWS signal comprising one or more of:

[0175] i) a PWS message comprising content of a public warning,

[0176] ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted bythe infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, or

[0177] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, wherein

[0178] the PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0179] Paragraph 2. A method according to paragraph 1, wherein the PWS signal comprises the scheduling information.

[0180] Paragraph 3. A method according to paragraph 2, wherein the first schedule is a schedule for system information (SI) in which the PWS message is comprised.

[0181] Paragraph 4. A method according to paragraph 2 or paragraph 3, wherein the PWS message is comprised in a Physical Downlink Shared Channel (PDSCH).

[0182] Paragraph 5. A method according to paragraph 4, wherein the first schedule indicates time and frequency resources of the PDSCH in which the PWS is transmitted.

[0183] Paragraph 6. A method according to any of paragraphs 2 to 5, wherein the PWS signal is a MAC signal and the scheduling information is comprised in a MAC Control Element (CE) of the MAC signal.

[0184] Paragraph 7. A method according to paragraph 6, wherein the PWS signal comprises the PWS message in addition to the scheduling information and the PWS message is comprised in a MAC protocol data unit (PDU) of the MAC signal.

[0185] Paragraph 8. A method according to paragraph 6, wherein the scheduling information is comprised in a MAC protocol data unit (PDU) of the MAC signal.

[0186] Paragraph 9. A method according to any of paragraphs 2 to 8, wherein the PWS signal comprises a PWS message type indication in addition to the scheduling information, the PWS message type indication indicating a type of the PWS message to be transmitted by the infrastructure equipment.

[0187] Paragraph 10. A method according to paragraph 9, wherein the type of PWS message is a type of public warning of which the PWS message comprises content.

[0188] Paragraph 11. A method according to paragraph 9 or paragraph 10, wherein the PWS message type indication indicates one of a plurality of codebook entries each corresponding to a different type of PWS message.

[0189] Paragraph 12. A method according to paragraph 9 or paragraph 10, wherein the PWS signal is a MAC signal and the PWS message type indication indicates one of a plurality of code points in a MAC CE of the MAC signal each corresponding to a different type of PWS message.

[0190] Paragraph 13. A method according to paragraph 9, wherein the PWS signal is a MAC signal and the PWS message type indication is indicated by a reserved bit of a MAC CE of the MAC signal.

[0191] Paragraph 14. A method according to any of paragraphs 9 to 13, wherein the method comprises determining, based on the type of the PWS message, whether or not to drop on an-going data transmission with the infrastructure equipment to receive the PWS message.

[0192] Paragraph 15. A method according to any of paragraphs 2 to 14, wherein the first schedule indicates a periodicity with which the PWS message is transmitted.Paragraph 16. A method according to any of paragraphs 2 to 15, wherein the first schedule indicates a radio frame at which the PWS message is transmitted.

[0193] Paragraph 17. A method according to paragraph 16, wherein the first schedule indicates the radio frame at which the PWS message is transmitted by indicating an offset of the radio frame relative to a radio frame known by the communications device.

[0194] Paragraph 18. A method according to any of paragraphs 2 to 17, wherein the first schedule indicates a transport block size (TBS) of the PWS message.

[0195] Paragraph 19. A method according to any preceding paragraph, wherein the PWS signal comprises the geographical information of the PWS message.

[0196] Paragraph 20. A method according to paragraph 19, wherein the method comprises determining a location of the communications device,

[0197] determining that the location of the communications device is outside the geographical area for which the PWS message is intended and, in response,

[0198] determining not to receive the PWS message.

[0199] Paragraph 21. A method according to any preceding paragraph, wherein the PWS signal comprises the PWS message.

[0200] Paragraph 22. A method according to paragraph 21, wherein the PWS message is comprised in a MAC CE of the MAC signal.

[0201] Paragraph 23. A method according to any preceding paragraph, wherein the time window which the communications device should monitor for reception of the downlink transmission is a time window in which the communications device should monitor for a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises the first schedule or the third schedule. Paragraph 24. A method according to any preceding paragraph, wherein the method comprises

[0202] receiving an RRC release message from the infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive the PWS message,

[0203] transitioning from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, and

[0204] receiving the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

[0205] Paragraph 25. A method according to paragraph 24, wherein, in response to receiving the instruction to receive the PWS message, the method further comprises

[0206] starting a timer upon expiry of which the communications device is configured to re-enter the RRC connected mode if the PWS message has not been received, and

[0207] determining, based on the instruction, to not re-enter the RRC connected mode until the PWS message has been received, or until the timer expires.

[0208] Paragraph 26. A method according to paragraph 24 or paragraph 25, wherein, in response to the instruction, the method comprises monitoring paging occasions configured for the communications device to receive a paging signal at a higher rate than a DRX cycle configured for the communications device.

[0209] Paragraph 27. A method according to any of paragraphs 24 to 26, wherein the method comprises, in response to the instruction, monitoring paging occasions configured for the communications device to receive a paging signal, wherein a first available one of the pagingoccasions is monitored after the communications device transitions to the RRC idle mode or RRC inactive mode and each subsequent paging occasion is monitored until the paging signal is received.

[0210] Paragraph 28. A method according to paragraph 26 or paragraph 27, wherein the paging signal comprises a PWS message type indication.

[0211] Paragraph 29. A method according to any of paragraphs 26 to 28, wherein the PWS signal is the paging signal.

[0212] Paragraph 30. A method according to any of paragraphs 24 to 29, wherein, in response to the instruction, the method comprises monitoring one or more system information blocks for the PWS message.

[0213] Paragraph 31. A method according to any of paragraphs 24 to 30, wherein, the instruction is comprised in a releaseCause information element of the RRC release message, or in another information element of the RRC release message.

[0214] Paragraph 32. A method according to any preceding paragraph, wherein the method comprises transmitting, to the infrastructure equipment, a preference indication indicating one or more preferred types of PWS message which the communications device wishes to receive and / or a preference indication indicating one or more non-preferred types of PWS message which the communications device does not wish to receive.

[0215] Paragraph 33. A method according to any preceding paragraph, wherein the PWS message is the RRC signal and the RRC signal is an RRC release message.

[0216] Paragraph 34. A method of operating infrastructure equipment of a wireless communications network, the method comprising

[0217] transmitting a Public Warning System (PWS) signal to a communications device, the PWS signal comprising one or more of:

[0218] i) a PWS message comprising content of a public warning,

[0219] ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule or

[0220] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, wherein

[0221] the PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0222] Paragraph 35. A method according to paragraph 34, wherein the PWS signal comprises the scheduling information in addition to a PWS message type indication, the PWS message type indication indicating a type of the PWS message to be transmitted by the infrastructure equipment.

[0223] Paragraph 36. A method according to paragraph 35, wherein the scheduling information is transmitted in addition to the PWS message type indication when the PWS message type is one of a set of selected PWS message types.

[0224] Paragraph 37. A method according to any of paragraphs 34 to 36, comprising

[0225] receiving, from the communications device, a preference indication indicating one or more preferred PWS message types which the communications device wishes to receive and / ora preference indication indicating one or more non-preferred types of PWS message the communications device does not wish to receive, and

[0226] transmitting an RRC release message to the communications device when the type of PWS message is one of the preferred types and / or transmitting the RRC release message to the communications device when the type of PWS message is not one of the non-preferred types of PWS message, wherein, optionally, the RRC release message is the PWS signal. Paragraph 38. A method according to any of paragraphs 34 to 37, comprising transmitting the PWS signal to the communications device when the communications device is inside the geographical area for which the PWS message is intended.

[0227] Paragraph 39. A method according to any of paragraphs 34 to 38, comprising

[0228] selecting to transmit the PWS signal as a MAC signal, RRC signal or paging signal based on a type of the PWS message.

[0229] Paragraph 40. A method according to paragraph 39, wherein the PWS signal is selected to be transmitted as a MAC signal when the PWS message is a Commercial Mobile Alert Service (CMAS) message.

[0230] Paragraph 41. A method according to paragraph 39 or paragraph 40, wherein the PWS signal is selected to be transmitted as an RRC signal when the PWS message is an Earthquake and Tsunami Warning System (ETWS) message.

[0231] Paragraph 42. A method of operating a communications device, the method comprising receiving a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message,

[0232] transitioning from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, and

[0233] receiving the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

[0234] Paragraph 43. A method according to paragraph 42, wherein, in response to receiving the instruction to receive the PWS message, the method further comprises

[0235] starting a timer upon expiry of which the communications device is configured to re-enter the RRC connected mode if the PWS message has not been received, and

[0236] determining, based on the instruction, to not re-enter the RRC connected mode until the PWS message has been received, or until the timer expires.

[0237] Paragraph 44. A method according to paragraph 42 or paragraph 43, wherein, in response to the instruction, the method comprises monitoring paging occasions configured for the communications device to receive a paging signal at a higher rate than a DRX cycle configured for the communications device.

[0238] Paragraph 45. A method according to any of paragraphs 42 to 44, wherein the method comprises, in response to the instruction, monitoring paging occasions configured for the communications device to receive a paging signal, wherein a first available one of the paging occasions is monitored after the communications device transitions to the RRC idle mode or RRC inactive mode and each subsequent paging occasion is monitored until the paging signal is received.

[0239] Paragraph 46. A method according to any of paragraphs 42 to 45, wherein, in response to the instruction, the method comprises monitoring one or more system information blocks for the PWS message.Paragraph 47. A method according to any of paragraphs 42 to 46, wherein, the instruction is comprised in a releaseCause information element of the RRC release message, or in another information element of the RRC release message.

[0240] Paragraph 48. A method of operating infrastructure equipment of a wireless communications network, the method comprising

[0241] transmitting a Radio Resource Control (RRC) release message to a communications device, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message.

[0242] Paragraph 49. A method according to paragraph 48, wherein the method comprises transmitting the RRC release message comprising the instruction to receive the PWS message when the PWS message is one of a set of one or more particular types of PWS message.

[0243] Paragraph 50. A method according to paragraph 49, wherein the set of one or more particular types of PWS message are PWS messages for an emergency scenario.

[0244] Paragraph 51. A method according to any of paragraphs 49 or 50, wherein the method comprises

[0245] receiving, from the communications device, a preference indication indicating one or more preferred types of PWS message which the communications device wishes to receive and / or a preference indication indicating one or more non-preferred PWS message types which the communications device does not wish to receive, wherein the set of one or more particular types of PWS message comprise the one or more preferred types of PWS message and the set of one or more particular types of PWS message do not comprise any of the non-preferred types of PWS message.

[0246] Paragraph 52. A communications device comprising

[0247] a transmitter configured to transmit signals,

[0248] a receiver configured to receive signals, and

[0249] a controller configured in combination with the transmitter and the receiver to receive a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network, the PWS signal comprising one or more of:

[0250] i) a PWS message comprising content of a public warning,

[0251] ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, or

[0252] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, wherein

[0253] the PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0254] Paragraph 53. Infrastructure equipment for a wireless communications network, the infrastructure equipment comprising

[0255] a transmitter configured to transmit signals,

[0256] a receiver configured to receive signals, and

[0257] a controller configured in combination with the transmitter and the receiver to transmit a Public Warning System (PWS) signal to a communications device, the PWS signal comprising one or more of:

[0258] i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule or

[0259] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, wherein

[0260] the PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0261] Paragraph 54. A communications device comprising

[0262] a transmitter configured to transmit signals,

[0263] a receiver configured to receive signals, and

[0264] a controller configured in combination with the transmitter and the receiver to

[0265] receive a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message,

[0266] transition from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, and

[0267] receive the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

[0268] Paragraph 55. Infrastructure equipment for a wireless communications network, the infrastructure equipment comprising

[0269] a transmitter configured to transmit signals,

[0270] a receiver configured to receive signals, and

[0271] a controller configured in combination with the transmitter and the receiver to transmit a Radio Resource Control (RRC) release message to a communications device, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message.

[0272] Paragraph 56. Circuitry for a communications device, the circuitry comprising

[0273] transmitter circuitry configured to transmit signals,

[0274] receiver circuitry configured to receive signals, and

[0275] controller circuitry configured in combination with the transmitter circuitry and the receiver circuitry to

[0276] receive a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network, the PWS signal comprising one or more of:

[0277] i) a PWS message comprising content of a public warning,

[0278] ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, or

[0279] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, wherein

[0280] the PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0281] Paragraph 57. Circuitry for infrastructure equipment of a wireless communications network, the circuitry comprising

[0282] transmitter circuitry configured to transmit signals,receiver circuitry configured to receive signals, and

[0283] controller circuitry configured in combination with the transmitter circuitry and the receiver circuitry to

[0284] transmit a Public Warning System (PWS) signal to a communications device, the PWS signal comprising one or more of:

[0285] i) a PWS message comprising content of a public warning,

[0286] ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule or

[0287] iii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, wherein

[0288] the PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

[0289] Paragraph 58. Circuitry for a communications device, the circuitry comprising

[0290] transmitter circuitry configured to transmit signals,

[0291] receiver circuitry configured to receive signals, and

[0292] controller circuitry configured in combination with the transmitter circuitry and the receiver circuitry to

[0293] receive a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message,

[0294] transition from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, and

[0295] receive the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

[0296] Paragraph 59. Circuitry for infrastructure equipment of a wireless communications network, the circuitry comprising

[0297] transmitter circuitry configured to transmit signals,

[0298] receiver circuitry configured to receive signals, and

[0299] controller circuitry configured in combination with the transmitter circuitry and the receiver circuitry to

[0300] transmit a Radio Resource Control (RRC) release message to a communications device, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message.

[0301] Paragraph 60. A computer program which, when the program is executed by a computer, cause the computer to perform the method of any of paragraphs 1 to 51.

[0302] Paragraph 61. A non-transitory computer-readable storage medium storing a computer program according to paragraph 60.

[0303] It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and / or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and / or processors may be used without detracting from the embodiments.

[0304] Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally beimplemented at least partly as computer software running on one or more data processors and / or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and / or processors.

[0305] Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in any manner suitable to implement the technique.

[0306] References

[0307] [1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009.

[0308] [2] TR 38.913, “Study on Scenarios and Requirements for Next Generation Access Technologies (Release 14)”, 3rd Generation Partnership Project, v14.3.0, August 2017.

[0309] [3] TS 38.470, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NG-RAN; F1 general aspects and principles (Release 17)”, 3GPP, V17.4.0, March 2023.

[0310] [4] TS 38.473, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NG-RAN; F1 application protocol (F1AP) (Release 17)”, 3GPP, V17.4.1, April 2023.

[0311] [5] TS 38.401, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NG-RAN; Architecture description (Release 17)”, 3GPP, V17.4.0, March 2023.

[0312] [6] TR 38.811, “Study on New Radio (NR) to support non terrestrial networks (Release 15)”, V15.4.0, 3GPP, October 2020.

[0313] [7] RP-243278, “Revised WID on Non-Terrestrial Networks (NTN) for Internet of Things (loT) Phase 3”, 3GPP TSG RAN Meeting#106, 9-12 December 2024.

[0314] [8] TS 36.300, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 18)”, v18.4.0, 3GPP, December 2024.

[0315] [9] TS 22.16837, “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Earthquake and Tsunami Warning System (ETWS) requirements; Stage 1 (Release 8)”, v8.3.0, December 2012.

[0316]

[0010] TS 22.268, “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Public Warning System (PWS) requirements (Release 19)”, v19.0.0, 3GPP, December 2024.

[0317]

[0011] TS 36.331, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification (Release 18)”, v18.5.0, 3GPP, March 2025.

[0318]

[0012] TS 36.212, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding (Release 18)”, v18.1.0, 3GPP, December 2024.

[0319]

[0013] R2-2501275, “Impact of introducing PWS broadcasting for NB-loT”, 3GPP TSG-RAN WG2 Meeting #129, Samsung, 17-21 February 2025.

Claims

CLAIMSWhat is claimed is:

1. A method of operating a communications device, the method comprisingreceiving a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network, the PWS signal comprising one or more of:i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, oriii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, whereinthe PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

2. A method according to claim 1 , wherein the PWS signal comprises the scheduling information.

3. A method according to claim 2, wherein the first schedule is a schedule for system information (SI) in which the PWS message is comprised.

4. A method according to claim 2, wherein the PWS message is comprised in a Physical Downlink Shared Channel (PDSCH).

5. A method according to claim 4, wherein the first schedule indicates time and frequency resources of the PDSCH in which the PWS is transmitted.

6. A method according to claim 2, wherein the PWS signal is a MAC signal and the scheduling information is comprised in a MAC Control Element (CE) of the MAC signal.

7. A method according to claim 6, wherein the PWS signal comprises the PWS message in addition to the scheduling information and the PWS message is comprised in a MAC protocol data unit (PDU) of the MAC signal.

8. A method according to claim 6, wherein the scheduling information is comprised in a MAC protocol data unit (PDU) of the MAC signal.

9. A method according to claim 2, wherein the PWS signal comprises a PWS message type indication in addition to the scheduling information, the PWS message type indication indicating a type of the PWS message to be transmitted by the infrastructure equipment.

10. A method according to claim 9, wherein the type of PWS message is a type of public warning of which the PWS message comprises content.

11. A method according to claim 9, wherein the PWS message type indication indicates one of a plurality of codebook entries each corresponding to a different type of PWS message.

12. A method according to claim 9, wherein the PWS signal is a MAC signal and the PWS message type indication indicates one of a plurality of code points in a MAC CE of the MAC signal each corresponding to a different type of PWS message.

13. A method according to claim 9, wherein the PWS signal is a MAC signal and the PWS message type indication is indicated by a reserved bit of a MAC CE of the MAC signal.

14. A method according to claim 9, wherein the method comprisesdetermining, based on the type of the PWS message, whether or not to drop on an-going data transmission with the infrastructure equipment to receive the PWS message.

15. A method according to claim 2, wherein the first schedule indicates a periodicity with which the PWS message is transmitted.

16. A method according to claim 2, wherein the first schedule indicates a radio frame at which the PWS message is transmitted.

17. A method according to claim 16, wherein the first schedule indicates the radio frame at which the PWS message is transmitted by indicating an offset of the radio frame relative to a radio frame known by the communications device.

18. A method according to claim 2, wherein the first schedule indicates a transport block size (TBS) of the PWS message.

19. A method according to claim 1, wherein the PWS signal comprises the geographical information of the PWS message.

20. A method according to claim 19, wherein the method comprisesdetermining a location of the communications device,determining that the location of the communications device is outside the geographical area for which the PWS message is intended and, in response,determining not to receive the PWS message.

21. A method according to claim 1 , wherein the PWS signal comprises the PWS message.

22. A method according to claim 21 , wherein the PWS message is comprised in a MAC CE of the MAC signal.

23. A method according to claim 1 , wherein the time window which the communications device should monitor for reception of the downlink transmission is a time window in which the communications device should monitor for a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises the first schedule or the third schedule.

24. A method according to claim 1 , wherein the method comprisesreceiving an RRC release message from the infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive the PWS message,transitioning from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, andreceiving the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

25. A method according to claim 24, wherein, in response to receiving the instruction to receive the PWS message, the method further comprisesstarting a timer upon expiry of which the communications device is configured to re-enter the RRC connected mode if the PWS message has not been received, anddetermining, based on the instruction, to not re-enter the RRC connected mode until the PWS message has been received, or until the timer expires.

26. A method according to claim 24, wherein, in response to the instruction, the methodcomprises monitoring paging occasions configured for the communications device to receive a paging signal at a higher rate than a DRX cycle configured for the communications device.

27. A method according to claim 24, wherein the method comprises, in response to the instruction, monitoring paging occasions configured for the communications device to receive a paging signal, wherein a first available one of the paging occasions is monitored after the communications device transitions to the RRC idle mode or RRC inactive mode and each subsequent paging occasion is monitored until the paging signal is received.

28. A method according to claim 26, wherein the paging signal comprises a PWS message type indication.

29. A method according to claim 26, wherein the PWS signal is the paging signal.

30. A method according to claim 24, wherein, in response to the instruction, the method comprises monitoring one or more system information blocks for the PWS message.

31. A method according to claim 24, wherein, the instruction is comprised in a releaseCause information element of the RRC release message, or in another information element of the RRC release message.

32. A method according to claim 1 , wherein the method comprisestransmitting, to the infrastructure equipment, a preference indication indicating one or more preferred types of PWS message which the communications device wishes to receive and / or a preference indication indicating one or more non-preferred types of PWS message which the communications device does not wish to receive.

33. A method according to claim 1 , wherein the PWS message is the RRC signal and the RRC signal is an RRC release message.

34. A method of operating infrastructure equipment of a wireless communications network, the method comprisingtransmitting a Public Warning System (PWS) signal to a communications device, the PWS signal comprising one or more of:i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule oriii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, whereinthe PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

35. A method according to claim 34, wherein the PWS signal comprises the scheduling information in addition to a PWS message type indication, the PWS message type indication indicating a type of the PWS message to be transmitted by the infrastructure equipment.

36. A method according to claim 35, wherein the scheduling information is transmitted in addition to the PWS message type indication when the PWS message type is one of a set of selected PWS message types.

37. A method according to claim 34, comprisingreceiving, from the communications device, a preference indication indicating one or more preferred PWS message types which the communications device wishes to receive and / or a preference indication indicating one or more non-preferred types of PWS message the communications device does not wish to receive, andtransmitting an RRC release message to the communications device when the type of PWS message is one of the preferred types and / or transmitting the RRC release message to the communications device when the type of PWS message is not one of the non-preferred types of PWS message, wherein, optionally, the RRC release message is the PWS signal.

38. A method according to claim 34, comprising transmitting the PWS signal to the communications device when the communications device is inside the geographical area for which the PWS message is intended.

39. A method according to claim 34, comprisingselecting to transmit the PWS signal as a MAC signal, RRC signal or paging signal based on a type of the PWS message.

40. A method according to claim 39, wherein the PWS signal is selected to be transmitted as a MAC signal when the PWS message is a Commercial Mobile Alert Service (CMAS) message.

41. A method according to claim 39, wherein the PWS signal is selected to be transmitted as an RRC signal when the PWS message is an Earthquake and Tsunami Warning System (ETWS) message.

42. A method of operating a communications device, the method comprisingreceiving a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message,transitioning from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, andreceiving the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

43. A method according to claim 42, wherein, in response to receiving the instruction to receive the PWS message, the method further comprisesstarting a timer upon expiry of which the communications device is configured to re-enter the RRC connected mode if the PWS message has not been received, anddetermining, based on the instruction, to not re-enter the RRC connected mode until the PWS message has been received, or until the timer expires.

44. A method according to claim 42, wherein, in response to the instruction, the method comprises monitoring paging occasions configured for the communications device to receive a paging signal at a higher rate than a DRX cycle configured for the communications device.

45. A method according to claim 42, wherein the method comprises, in response to the instruction, monitoring paging occasions configured for the communications device to receive a paging signal, wherein a first available one of the paging occasions is monitored after the communications device transitions to the RRC idle mode or RRC inactive mode and each subsequent paging occasion is monitored until the paging signal is received.

46. A method according to claim 42, wherein, in response to the instruction, the method comprises monitoring one or more system information blocks for the PWS message.

47. A method according to claim 42, wherein, the instruction is comprised in a releaseCause information element of the RRC release message, or in another information element of the RRC release message.

48. A method of operating infrastructure equipment of a wireless communications network, the method comprisingtransmitting a Radio Resource Control (RRC) release message to a communications device, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message.

49. A method according to claim 48, wherein the method comprisestransmitting the RRC release message comprising the instruction to receive the PWS message when the PWS message is one of a set of one or more particular types of PWS message.

50. A method according to claim 49, wherein the set of one or more particular types of PWS message are PWS messages for an emergency scenario.

51. A method according to claim 49, wherein the method comprisesreceiving, from the communications device, a preference indication indicating one or more preferred types of PWS message which the communications device wishes to receive and / or a preference indication indicating one or more non-preferred PWS message types which the communications device does not wish to receive, wherein the set of one or more particular types of PWS message comprise the one or more preferred types of PWS message and the set of one or more particular types of PWS message do not comprise any of the non-preferred types of PWS message.

52. A communications device comprisinga transmitter configured to transmit signals,a receiver configured to receive signals, anda controller configured in combination with the transmitter and the receiver to receive a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network, the PWS signal comprising one or more of:i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, oriii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, whereinthe PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

53. Infrastructure equipment for a wireless communications network, the infrastructure equipment comprisinga transmitter configured to transmit signals,a receiver configured to receive signals, anda controller configured in combination with the transmitter and the receiver to transmit a Public Warning System (PWS) signal to a communications device, the PWS signal comprising one or more of:i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating atime window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule oriii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, whereinthe PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

54. A communications device comprisinga transmitter configured to transmit signals,a receiver configured to receive signals, anda controller configured in combination with the transmitter and the receiver toreceive a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message,transition from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, andreceive the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

55. Infrastructure equipment for a wireless communications network, the infrastructure equipment comprisinga transmitter configured to transmit signals,a receiver configured to receive signals, anda controller configured in combination with the transmitter and the receiver to transmit a Radio Resource Control (RRC) release message to a communications device, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message.

56. Circuitry for a communications device, the circuitry comprisingtransmitter circuitry configured to transmit signals,receiver circuitry configured to receive signals, andcontroller circuitry configured in combination with the transmitter circuitry and the receiver circuitry toreceive a Public Warning System (PWS) signal from infrastructure equipment of a wireless communications network, the PWS signal comprising one or more of:i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule, oriii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, whereinthe PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

57. Circuitry for infrastructure equipment of a wireless communications network, the circuitry comprisingtransmitter circuitry configured to transmit signals,receiver circuitry configured to receive signals, andcontroller circuitry configured in combination with the transmitter circuitry and the receiver circuitry totransmit a Public Warning System (PWS) signal to a communications device, the PWS signal comprising one or more of:i) a PWS message comprising content of a public warning,ii) scheduling information comprising either a first schedule according to which the PWS message is transmitted by the infrastructure equipment or a second schedule indicating a time window which the communications device should monitor for reception of a downlink transmission from the infrastructure equipment, the downlink transmission comprising the first schedule or a third schedule according to which another downlink transmission is transmitted by the infrastructure equipment, the other downlink transmission comprising the first schedule when the downlink transmission comprises the third schedule oriii) geographical information of the PWS message indicating a geographical area for which the PWS message is intended, whereinthe PWS signal is a Medium Access Control (MAC) signal, a Radio Resource Control (RRC) signal or a paging signal.

58. Circuitry for a communications device, the circuitry comprisingtransmitter circuitry configured to transmit signals,receiver circuitry configured to receive signals, andcontroller circuitry configured in combination with the transmitter circuitry and the receiver circuitry toreceive a Radio Resource Control (RRC) release message from infrastructure equipment of a wireless communications network, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message,transition from an RRC connected mode to an RRC idle mode or RRC inactive mode in response to receiving the RRC release message, andreceive the PWS message when the communications device is in the RRC idle mode or the RRC inactive mode.

59. Circuitry for infrastructure equipment of a wireless communications network, the circuitry comprisingtransmitter circuitry configured to transmit signals,receiver circuitry configured to receive signals, andcontroller circuitry configured in combination with the transmitter circuitry and the receiver circuitry totransmit a Radio Resource Control (RRC) release message to a communications device, the RRC release message comprising an instruction to receive a Public Warning System (PWS) message.

60. A computer program which, when the program is executed by a computer, cause the computer to perform the method of claim 1.

61. A non-transitory computer-readable storage medium storing a computer program according to claim 60.

Images