Methods, communications devices, and infrastructure equipment

Abstract

A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell is provided. The method comprises transmitting one or more synchronisation signal blocks (SSBs) in the cell. Each of the one or more SSBs comprises a master information block (MIB). The method comprises transmitting one or more system information blocks (SIBs) of a first type in the cell. Each of the one or more SIBs of the first type comprises an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH. Each MIB in the one or more SSBs comprises information required to decode the one or more SIBs of the first type. The method comprises transmitting, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

Description

[0001] METHODS, COMMUNICATIONS DEVICES, AND INFRASTRUCTURE EQUIPMENT

[0002] BACKGROUND 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 application claims Paris Convention priority from European patent application number EP24167033.0, filed on 27 March 2024, the contents 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 / 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 emergency responder 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 / new radio access technology (RAT) systems, or indeed future 6G wireless communications, as well as future iterations / releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements. 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.

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

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0017] Figure 2 schematically represents some aspects of an NR-type wireless telecommunications system which may be configured to operate in accordance with certain embodiments of the present disclosure;

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

[0019] Figure 4 is a message flow diagram showing a typical four-step random access (RACH) procedure;

[0020] Figure 5 is a message flow diagram showing a typical two-step RACH procedure;

[0021] Figure 6 schematically illustrates the components of an SSB;

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

[0023] Figure 8 schematically illustrates a RACH Occasion configuration;

[0024] Figure 9 schematically illustrates valid and invalid ROs;

[0025] Figure 10 schematically illustrates an example of a TDD slot format configuration;

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

[0027] Figure 12 schematically illustrates an example of an on-demand SSB;

[0028] Figure 13 illustrates a part schematic, part message flow diagram representation of a wireless communications system comprising a communications device and infrastructure equipment in accordance with embodiments;

[0029] Figure 14 schematically illustrates an example of a master information block (MIB) in accordance with example embodiments;

[0030] Figure 15 is a flow diagram illustrating a method of operating infrastructure equipment of a wireless communications network in accordance with example embodiments;

[0031] Figure 16 is a flow diagram illustrating a method of operating an NES communications device in accordance with example embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Long Term Evolution Advanced Radio Access Technology (4G)

[0033] Figure 1 provides a schematic diagram illustrating some basic functionality of a mobile telecommunications network / system 6 operating generally in accordance with LTE principles, but which may also support other radio access technologies, and which may be adapted to implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body, and also described in many books on the subject, for example, Holma H. and Toskala A [1], It will be appreciated that operational aspects of the telecommunications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

[0034] 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, inter-connected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

[0035] 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.

[0036] Base stations, which are an example of network infrastructure equipment, may also be referred to as transceiver stations, nodeBs, eNodeBs, eNB, gNodeBs, gNB and so forth. In this regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality. However, certain embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

[0037] New Radio Access Technology (5G)

[0038] 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],

[0039] An example configuration of a wireless communications network which uses some of the terminology proposed for and used in NR and 5G is shown in Figure 2. In Figure 2 a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 by a connection interface represented as a line 16. Each of the TRPs 10 is arranged to transmit and receive signals via a wireless access interface within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 10, forms a cell of the wireless communications network as represented by a circle 12. As such, wireless communications devices 14 which are within a radio communications range provided by the cells 12 can transmit and receive signals to and from the TRPs 10 via the wireless access interface. Each of the distributed units 41, 42 are connected to a central unit (CU) 40 (which may be referred to as a controlling node) via an interface 46. The central unit 40 is then connected to the core network 20 (which may 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.

[0040] 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.

[0041] The TRPs 10 of Figure 2 may in part have a corresponding functionality to a base station or eNodeB of an LTE network. Similarly, the communications devices 14 may have a functionality corresponding to the UE devices 4 known for operation with an LTE network. It will be appreciated therefore that operational aspects of a new RAT network (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be different to those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network component, base stations and communications devices of a new RAT network will be functionally similar to, respectively, the core network component, base stations and communications devices of an LTE wireless communications network.

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

[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.

[0044] Thus, certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architectures shown in Figures 1 and 2. It will thus be appreciated the specific wireless telecommunications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a communications device, wherein the specific nature of the network infrastructure equipment / access node and the communications device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a base station, such as an LTE-type base station 1 as shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment may comprise a control unit / controlling node 40 and / or a TRP 10 of the kind shown in Figure 2 which is adapted to provide functionality in accordance with the principles described herein.

[0045] 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.

[0046] The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers and transceivers described in relation to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices in order to transmit and receive radio signals in accordance for example with the 5G / NR standard. The controllers 34, 44 (as well as other controllers described in relation to examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc., configured to carry out instructions which are stored on a computer readable medium, such as a non-volatile memory. The processing steps described herein may be carried out by, for example, a microprocessor in conjunction with a random access memory, operating according to instructions stored on a computer readable medium. The transmitters, the receivers and the controllers are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the infrastructure equipment / TRP / base station as well as the UE / communications device will in general comprise various other elements associated with its operating functionality.

[0047] As shown in Figure 3, the TRP 10 also includes a network interface 50 which connects to the DU 42 via a physical interface 16. The network interface 50 therefore provides a communication link for data and signalling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

[0048] The interface 46 between the DU 42 and the CU 40 is known as the F 1 interface which can be a physical or a logical interface. The Fl interface 46 between CU and DU may operate in accordance with 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 Fl interface 46 from the DU 42 to the CU 40.

[0049] 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 Fl 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 Fl interface 46.

[0050] 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 El interface connected with the CU-UP and an Fl-C interface connected with the DU 42. As will be appreciated, the Fl-C interface carries control plane signalling of the Fl 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 El interface connected with the CU-CP and an Fl-U interface connected with the DU 42. As will be appreciated, the Fl-U interface carries user plane signalling of the Fl interface 46.

[0051] Random Access (RACH) Procedures

[0052] In wireless communications networks, such as LTE and NR 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 / process. The RACH procedure may be a two-step RACH procedure or a four-step RACH procedure as described in more detail below.

[0053] In addition, there exists Radio Resource Control (RRC) modes for communications devices. For example, it is common to support an RRC idle mode (RRC IDLE) and an RRC connected mode (RRC CONNECTED). A communications device in the RRC IDLE 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.

[0054] 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.

[0055] Figure 4 shows atypical 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 wireless communications system such as that described by reference to Figure 2. A communications device (or UE), which may be in an RRC IDLE 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 gNB. When the gNB detects the random access preamble 51, the gNB determines a random access preamble index / identity (RAPID) of the random access preamble 51. Assuming the random access preamble 51 is successfully received by the gNB, the gNB 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 gNB and grant uplink resources for the communications device to transmit the data in.

[0056] Following the reception of the random access response message 52, the communications device transmits the scheduled transmission of data 53 to the gNB (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 gNB at the same time and using the same frequency resources, the scheduled transmission of data 53 is successfully received by the gNB. The gNB will respond to the scheduled transmission 53 with a contention resolution message 54 (message 4).

[0057] In 5G / NR systems, an “inactive” RRC mode (RRC INACTIVE) may be used, where a UE is able to start data transfer with a low delay in the RRC INACTIVE mode without transition to the

[0058] RRC CONNECTED mode. 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 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. In addition, it is considered that a two-step RACH procedure has potential benefits for channel access in NR unlicensed spectrum (NR-U).

[0059] 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 RRC IDLE, RRC INACTIVE or RRC CONNECTED modes.

[0060] 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, PUSCH 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.

[0061] Synchronisation Signal Block (SSB)

[0062] As will be known to one skilled in the art, the Synchronisation Signal Block (SSB) (also called as SS / PBCH block) is used for initial access and cell reselection. An example of an SSB is schematically illustrated in Figure 6.

[0063] As shown in Figure 6, the SSB comprises of a Primary Synchronisation Signal (PSS), a Secondary Synchronisation Signal (SSS) and a Physical Broadcast Channel (PBCH). The SSB comprises information for a communications device, such as a UE, to detect, measure and access a cell. The SSB shown in Figure 6 comprises 4 OFDM symbols and 240 subcarriers. The PSS and SSS each occupy 127 subcarriers. The PBCH occupies two OFDM symbols of 240 subcarriers and also 2 blocks of 48 subcarriers at the top and bottom of the SSS. The SSB may be configured with a periodicity, PSSB, of between 5 ms and 160 ms. For initial cell selection, the UE assumes a periodicity of 20ms.

[0064] An SSB burst set comprises a set of one or more time-multiplexed SSBs. Each SSB transmitted in a burst set uses a different downlink beam, thereby enabling beam sweeping to be implemented for SSB. An SSB burst set may be confined within 5 ms and may comprise up to 4, 8 and 64 SSBs for frequency bands below 3 GHz, between 3 GHz - 6 GHz and for FR2 respectively. As will be understood by one skilled in the art, SSB burst sets may be transmitted periodically.

[0065] An example SSB burst set in the case of 3 GHz - 6 GHz frequency is shown in Figure 7. The SSB burst set shown in Figure 7 comprises 8 SSBs labelled as SSB#1, SSB#2, SSB#3, SSB#4, SSB#5, SSB#6, SSB#7 and SSB#8 respectively. Each of the SSBs in the burst set is transmitted using a different downlink beam. In this example, 2 SSBs are configured per slot within 4 slots. Furthermore, the burst set is transmitted with a periodicity, PSSB, of 20 ms. Although not shown in Figure 7, the SSB burst set is transmitted by infrastructure equipment of a wireless communications network (such as a gNB) and received by a communications device (such as a UE).

[0066] The UE measures a signal quality of each SSB in the SSB burst set. The UE may then select one of the downlink beams based on the measured signal quality. For example, the UE may select the downlink beam with the highest measured signal quality provided that the measured signal quality is above a threshold (such as RSRP threshold). Then, the UE determines an uplink beam corresponding to the downlink beam to use for synchronisation with the infrastructure equipment. As will be appreciated by one skilled in the art, corresponding uplink and downlink beams form beam pairs which overlap. Therefore, the measurements of the signal quality of a downlink beam are an indication of the signal quality of the corresponding uplink beam in the beam pair.

[0067] In one example, the measured signal quality of an S SB is an RSRP of the SSB. The UE may measure the RSRP of each SSB in the SSB burst set and select the downlink beam on which the SSB with the highest RSRP was transmitted provided this measured RSRP is above a threshold (such as rsrp-ThresholdSSB).

[0068] The measurement of the RSRP of an SSB may be referred to as “SS-RSRP”. The measurement of the RSRP of an SSB may comprise measuring the RSRP on resource elements where SSS is transmitted. Alternatively, or in addition, the measurement of the RSRP of an SSB may comprise measuring the RSRP on resource elements where PBCH DMRS is transmitted.

[0069] In other examples, the measured signal quality of an SSB may be a Reference Signal Received Quality (SS-RSRQ) of the SSB. The SS-RSRQ is defined as the ratio of N x SS-RSRP / RSSI (Received Signal Strength Indicator), where N is the number of resource blocks. For example, the RSSI in NR is measured in one or more OFDM symbols in a SS / PBCH Block Measurement Time Configuration (SMTC). The SMTC is a configuration to the UE to set time window for measurement by using SSB. The OFDM symbols used for RSSI measurement can be configured by higher layers.

[0070] In initial access, after determining the uplink beam, the UE initiates a RACH procedure by transmitting PRACH on the determined uplink beam. For example, the UE may transmit message 51 or message 55 on the determined uplink beam. The PRACH may be transmitted on PRACH resources which have been configured for the UE to transmit the PRACH as part of initial access. For example, the PRACH may be transmitted in one of a plurality of RACH Occasions (ROs) configured for transmitting the PRACH.

[0071] RACH Occasions

[0072] As will be understood by a person skilled in the art, a PRACH configuration comprises a plurality of RACH Occasions (RO) configured in uplink communications resources of a wireless access interface. The ROs in a PRACH configuration may be periodically repeating. The ROs represent transmission opportunities for a UE to transmit a PRACH. Each RO may be configured to support up to 64 preambles. In this case, each RO may support a PRACH transmission of up to 64 UEs if each UE uses a different preamble for its PRACH transmission. The ROs may be Frequency Division Multiplexed (FDM) where infrastructure equipment of a wireless communications network can configure { 1, 2, 4, 8} FDM ROs for UEs.

[0073] ROs comprise time resources and frequency resources. The time resources of the ROs in a PRACH configuration are determined by a “PRACH Configuration Index”, which is an index to Tables 6.3.3.2-2, 6.3.3.2-3 & 6.3.3.2-4 in [6], which is hereby incorporated by reference in its entirety. There are 256, 263 and 256 PRACH configurations for FR1 FDD, FR1 TDD and FR2 respectively. The PRACH configuration index indicates a PRACH preamble format, a PRACH periodicity (known as a “PRACH Configuration Period”), a number of RACH Occasions within a PRACH period, the starting symbol of the RACH Occasion in a slot and a duration of the RACH Occasion.

[0074] An example PRACH configuration for an FR1 FDD system is shown Figure 8. The RACH Occasions are configured with FDM = 2 and with a PRACH Configuration Index = 184. The time resources of the ROs in the PRACH configuration can be obtained from Table 6.3.3.2-2 of [6]: The PRACH Configuration Period = 20 ms since an RO occurs in every even numbered SFN (x=2 & y=0). In each even numbered SFN, subframe 4 and 9 contain a slot with ROs, i.e., PRACH slot. In this example a 15 kHz subcarrier spacing is assumed and so each subframe which is 1 ms contains 1 slot. In each PRACH slot (i.e. in subframe 4 and 9), there are 7 sets of time domain ROs where each RO is 2 OFDM symbols long. Since FDM = 2, each time domain RO has 2 ROs, this gives 14 ROs in a PRACH slot as shown in Figure 8. There are therefore 28 ROs in a PRACH Configuration Period of 20 ms (2 PRACH slots in 20ms x 7 time domain ROs x 2 FDM = 28 ROs).

[0075] SSB to RACH Occasion Association

[0076] A UE may select an SSB received on a DL beam and transmit a PRACH using a corresponding UL beam. The gNB needs to know which SSB the UE has selected so that it can transmit a Random Access Response (RAR) to the UE using the same SSB beam selected by the UE, or a beam derived from the UE selected SSB beam. Since the UE uses an UL beam, the gNB may maximise its reception by tuning its receiver panels towards the direction of the UL beam. Since ROs and SSBs are configured independently, an SSB-RO association is used for the gNB to determine the UE selected SSB, so that the gNB can determine the SSB selected by the UE based on the RO and preamble used for the UE’s PRACH transmission.

[0077] In SSB-RO association, each SSB is associated with one or more ROs and preambles. Infrastructure equipment of a wireless communications network (such as a gNB) may transmit an indication of a number of SSBs associated with each RO and a number of preambles associated with each SSB. For example, the infrastructure equipment may transmit the following RRC parameter to the UE: ssb- perRACH-OccasionAndCB-PreamblesPerSSB. The values for ssb-perRACH-occasion may be { 1 / 8, ! ,

[0078] 1, 2, 4, 8, 16}. In other words, one SSB may be associated with 8, 4, 2 or 1 ROs, and an RO may be associated with 2, 4, 8 or 16 SSBs. In each RO, the SSB may be configured to associate with a subset of the 64 preambles or all of the 64 preambles. For the case where an RO is associated with 2, 4, 8 or 16 SSBs, each SSB may only be associated with a subset of the preambles in an RO. For example, if an RO is associated with 2 SSBs, then each SSB can be associated with at most 32 preambles in that RO. For the case where an SSB is associated with one or more ROs, the SSB can be associated with at most 64 preambles although it can be configured to occupy less than 64 preambles.

[0079] Once the SSB parameters, RO parameters and SSB-RO association parameters are configured, the UE may then perform the following steps in sequential order:

[0080] 1. Valid ROs determination

[0081] 2. Indexing the valid ROs

[0082] 3. Perform SSB-RO mapping

[0083] Valid ROs Determination

[0084] For FDD all configured ROs are valid.

[0085] For TDD, the following 3 validity conditions must be met for an RO to be valid:

[0086] First validity condition: A valid RO is contained fully in UL OFDM symbols since PRACH cannot be transmitted in DL OFDM symbols.

[0087] Second validity condition: In addition to being fully contained in UL OFDM symbols, there also needs to be a gap of NgapOFDM symbols between the end of an SSB and the start of the valid RO. The value of Ngap depends on the subcarrier spacing of the PRACH and it is defined in [7], the contents of which are hereby incorporated by reference in their entirety.

[0088] Third validity condition: If an RO and an SSB falls within a PRACH slot, the RO is invalid if it precedes the SSB. Examples of valid and invalid ROs are shown in Figure 9. The valid RO labelled as (A) in Figure 9 meets all the 3 validity conditions. The invalid ROs are labelled as (B) falling onto DL OFDM symbols, (C) insufficient gap between SSB and RO and (D) the RO precedes a SSB within a PRACH slot.

[0089] RO Indexing

[0090] Once the valid ROs are determined, they are indexed in the following order:

[0091] 1. First, in increasing order of preamble indexes within a single RO

[0092] 2. Second, in increasing order of frequency resource indexes for frequency multiplexed RO

[0093] 3. Third, in increasing order of time resource indexes for time multiplexed RACH occasions within a PRACH slot

[0094] 4. Fourth, in increasing order of indexes for PRACH slots

[0095] SSB-RO Mapping

[0096] The SSBs are then mapped to the indexed ROs sequentially by RO index. This mapping is repeated every “SSB-RO Association Period”. The SSB-RO Association Period is the smallest integer number of PRACH Configuration Periods required for all the SSBs in an SSB burst set to fully map to RO(s) at least once. In an SSB-RO Association Period, if any remaining ROs cannot fully map to all the SSBs of an SSB burst set, they are invalid ROs and are not used for PRACH transmissions. The allowed SSB-RO Association Periods for each PRACH Configuration Period are listed in Table 8.1-1 of [7], which is reproduced below as Table 1.

[0097] Table 1. PRACH Configuration Period and SSB-RO Association Period (from Table 8.1-1 of [7]) An example of an SSB to RO mapping for an SSB-RO association period will now be explained. Figure 10 illustrates a TDD slot format {DDDDU}, consisting of 4 DL slots followed by an UL slot as shown in Figure 10 operating in 15 kHz subcarrier spacing. SSB and PRACH are configured as follows:

[0098] • SSB burst set has 5 SSBs {SSB#1, SSB#2, SSB#3, SSB#4, SSB#5}

[0099] • SSB per RO = 'A, i.e., each SSB is mapped to 2 ROs

[0100] • Preambles per SSB = 64, i.e., all preambles in an RO are fully mapped to an SSB

[0101] • FDM RO = 2

[0102] • PRACH Configuration Index = 129 for FR1 TDD

[0103] Using the lookup table in Table 6.3.3.2-3 of [6], the time resource configuration for PRACH Configuration Index = 129 has a PRACH Configuration Period = 10 ms, as shown in Figure 11. Here, in each PRACH Configuration Period, Subframe 3, 4, 8 and 9 contain PRACH slot, and in each PRACH slot, there are 2 time domain ROs with duration 6 OFDM symbols each, which leads to 16 ROs in a PRACH Configuration Period (4 PRACH slot x 2 time domain ROs per PRACH slot x 2 FDM ROs). Since valid RO can only reside in UL OFDM symbols, only subframe 4 and 9 have valid ROs and the ROs in subframe 3 and 8 are invalid ROs. Hence, each PRACH Configuration Period has 8 valid ROs. For a PRACH Configuration Period = 10 ms, referring to Table 1 (i.e., from Table 8.1-1 of [7]), the required SSB-RO Association Period to fully map all 5 SSBs with SSB per RACH = 'A, is 2x PRACH Configuration Period (20 ms), giving 2 x 8 = 16 valid ROs. The 16 valid ROs in the 20 ms SSB-RO Association Period are indexed firstly by preamble, secondly by frequency, thirdly by time and lastly by PRACH slot as shown in Figure 11. The SSBs are then mapped to the indexed ROs sequentially, e.g., since SSB per RO = A, SSB#1 is mapped to RO#1 and RO#2, followed by SSB#2 is mapped to RO#3 and RO#4, etc. The 5 SSBs are fully mapped to the ROs once in the SSB-RO Association Period with 6 remaining ROs: RO#11, RO# 12, RO# 13, RO# 14, RO# 15 and RO# 16, that cannot fully map another set of 5 SSBs. Hence these 6 remaining ROs are Invalid ROs and are not used for PRACH transmissions.

[0104] Network Energy Saving (NES)

[0105] 3GPP is currently discussing network energy saving (NES). By reducing energy consumption in wireless communications networks, the impact of wireless communications on the environment can be reduced. For example, if less energy is consumed in wireless communications networks, fewer fossil fuels are burned, there are fewer greenhouse gas emissions and therefore environmental sustainability is improved. Furthermore, the reduction of energy consumption in wireless communications networks can reduce costs incurred by network operators.

[0106] 5G / NR can handle advanced services and applications requiring very high data rates (for example, XR). Additionally, 5G / NR networks are becoming denser, using more antennas, and utilising larger bandwidths and an increasing number of frequency bands. Therefore, in at least some cases, energy consumption in 5G / NR is increasing. Since 5G / NR is becoming increasingly pervasive across various industries and geographical areas, it is becoming increasingly important to reduce the environmental impact of 5G / NR networks. NES solutions are therefore required.

[0107] In addition, energy consumption has become a key part of the operating expenses (OPEX) for network operators. According to a report from the Global System for Mobile Communications (GSMA) [8], the energy cost of mobile networks accounts for approximately 23% of total operator costs. Most of the energy consumption comes from the radio access network and in particular from the Active Antenna Unit (AAU), with data centres and fibre transport accounting for a smaller share of the energy consumption. The energy consumption of a radio access network can be split into two parts: (1) a dynamic part which is only consumed when data transmission / reception is ongoing, and (2) a static part which is consumed all the time to maintain the necessary operation of the radio access network equipment, even when data transmission / reception is not on-going. Further details on NES can be found in [9],

[0108] In Release 19 of the 3GPP standards, an NES work item has been approved (

[0010] ). The objectives of the work item are the following:

[0109] 1. Specify procedures and signaling method(s) to support on-demand SSB SCell operation for UEs in connected mode configured with CA, for both intra- / inter-band CA.

[0110] 2. Study procedures and signaling method(s) to support on-demand SIB 1 for UEs in idle / inactive mode, including:

[0111] 3. Specify adaptation of common signal / channel transmissions.

[0112] NES System Information (SI)

[0113] As will be understood by a person skilled in the art, system information is transmitted by infrastructure equipment of a wireless communications network to communications devices in a cell provided by the infrastructure equipment. The system information informs the communications devices on how to access services provided by the wireless communications network. The system information 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.

[0114] 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 SIB 1, 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 Si-window size). SIB1 is periodically broadcasted over a downlink shared channel (DL-SCH), but may be provided on-demand as explained below. Periodically broadcasted SIB1 is typically an “always- on” signal. 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. SIB 1 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.

[0115] The other SIBs may comprise one or more of: SIB2-SIB18 and SIBpos.

[0116] — SIB2 comprises cell re-selection information, mainly related to the serving cell;

[0117] — SIB3 comprises information about the serving frequency and intra-frequency neighbouring cells relevant for cell re-selection (including cell re-selection parameters common for a frequency as well as cell specific re-selection parameters);

[0118] — SIB4 comprises information about other NR frequencies and inter-frequency neighbouring cells relevant for cell re-selection (including cell re-selection parameters common for a frequency as well as cell specific re-selection parameters), which can also be used for NR idle / inactive measurements;

[0119] — SIB5 comprises information about E-UTRA frequencies and E-UTRA neighbouring cells relevant for cell re-selection (including cell re-selection parameters common for a frequency as well as cell specific re-selection parameters);

[0120] — SIB6 comprises an ETWS primary notification;

[0121] — SIB7 comprises an ETWS secondary notification;

[0122] — SIB8 comprises a CMAS warning notification;

[0123] — SIB9 comprises information related to GPS time and Coordinated Universal Time (UTC);

[0124] — SIB 10 comprises the Human-Readable Network Names (HRNN) of the NPNs listed in SIB1;

[0125] — SIB11 comprises information related to idle / inactive measurements;

[0126] — SIB 15 comprises information related to disaster roaming;

[0127] — SIB 16 comprises slice-based cell reselection information;

[0128] — SIB 17 comprises information related to TRS configuration for UEs in

[0129] RRC IDLE / RRC INACTIVE;

[0130] — SIBpos comprises positioning assistance data as defined in TS 37.355 and TS 38.331;

[0131] — SIB 18 comprises information related to the Group IDs for Network selection (GINs) associated with SNPNs listed in SIB1. Further information regarding existing SI can be found in TS38.300 vl8.0.0, the contents of which are hereby incorporated by reference in their entirety.

[0132] As mentioned above, the approved NES work item in Release 19 of the 3GPP standards has an objective to specify adaptations of common signal / channel transmissions. For example, adaptation of SSB transmissions, SIB1 transmissions and PRACH configurations are being considered for NES.

[0133] Adapted SSB and SIB1 Transmissions

[0134] In Release-15 of the 3GPP standards, the time domain positions of transmitted SSBs within a half frame are semi-statically configured. Furthermore, UEs assume a single periodicity for the transmitted SSBs. In NES, it is being considered to adapt SSB and / or SIB 1 transmissions by adapting a transmission pattern of SSB and / or SIB1 transmissions. For example, the transmission pattern of an SSB and / or SIB1 may be adapted to change periodicity and / or time resource locations of SSB and / or SIB 1. In another example, the transmission pattern of an SSB and / or SIB1 may be adapted to omit specified elements from SSB and / or SIB1. The transmission pattern can be adapted semi-statically or dynamically

[0010] ,

[0135] On-demand SIB 1

[0136] As one example of an adaptation, it has been suggested to introduce an on-demand SIB1. In other words, instead of infrastructure equipment of the wireless communications network periodically broadcasting SIB1, it has been proposed for infrastructure equipment (i.e. NES infrastructure equipment) to broadcast SIB 1 only in response to a request (or trigger such as a wake-up signal) from a UE. Since the SIB 1 would thereby be transmitted less often, network energy savings would be increased. However, the details of such an on-demand SIB1 have not yet been discussed. Furthermore, existing UEs which do not support NES (also referred to as “non-NES UEs”) are configured to expect the SIB1 to be periodic. Since non- NES UEs are already deployed in wireless communications networks, it is important that NES solutions do not significantly impact performance for non-NES UEs.

[0137] It has also been suggested, instead of on-demand SIB1, and as another example of adaptation, to increase the period between successive SIB1 transmissions so that SIB Is are transmitted less often, thereby reducing network energy consumption.

[0138] Furthermore, as another example of adaptation, it has been suggested to introduce an on-demand SSB to improve network energy savings as will be discussed in more detail below.

[0139] On-demand SSB

[0140] Typically, a gNB broadcasts SSBs periodically. SSB is an “always-on” signal. This means the gNB must be awake to transmit SSB, even when no active UE is camped on the cell provided by the gNB. Consequently, SSB transmissions lead to high network energy consumption. A solution to reduce the network energy consumption caused by the mandatory periodic, always-on SSB is to configure an “on- demand SSB”. In the case of on-demand SSB, the gNB does not transmit SSB until it receives an activation command. The activation command may be received by the gNB from other network infrastructure equipment, or from a UE, requesting the on-demand SSB transmission.

[0141] An example of on-demand SSB transmission will be described with reference to Figure 12. As shown in Figure 12, a UE, or other network infrastructure equipment aside from the gNB 72, transmits an on- demand SSB activation command 74 to a gNB 72. Before the UE, or the other network infrastructure equipment, transmits the activation command 74 to the gNB 72, there is a period 78 during which SSB is not transmitted by the gNB 72. In response to receiving the activation command 74, the gNB 72 broadcasts a plurality of SSBs 84 during a transmission period 80. Within the transmission period 80, the SSBs 84 may be broadcasted periodically as shown in Figure 12. The gNB 72 may broadcast one SSB burst set in response to the activation command 74. The gNB 72 may receive a deactivation command 76 from the UE (or another UE in the cell provided by the gNB 72, or other network infrastructure equipment) to stop transmitting SSB. In response to receiving the deactivation command 76, the gNB 72 may stop transmitting SSB. Therefore, there is a period 82 after receiving the deactivation command during which SSB is not transmitted by the gNB 72. In some examples, the gNB 72 may start a timer after receiving the activation command 74 and, when the timer expires, the gNB 72 may stop transmitting SSB.

[0142] In Release-19 of the 3GPP standards, on-demand SSB will be specified for secondary cells (SCells). However, it is envisaged that on-demand SSB may be applied to primary cell (Pcell) and primary SCG cell (PScell) in future releases.

[0143] It has also been suggested, instead of on-demand SSB, and as another example of adaptation, to increase the period between successive SSB transmissions so that SSBs are transmitted less often, thereby reducing network energy consumption.

[0144] As will be explained in more detail below, it is also being considered to perform time-domain adaptation of PRACH forNES.

[0145] Time-domain Adaptation of PRACH

[0146] One of objectives for adaptation of common channels in Rel-19 NES WID is adaptation of PRACH in timedomain.

[0147] Although the adaptation of SSB, SIB 1 and PRACH configurations are aimed at providing improved network energy savings, the implementation of these adaptations may cause technical problems. For example, if the period between successive transmissions SSB burst sets in a periodic SSB burst set transmission is increased, this will improve network energy savings because the gNB transmits SSB burst sets less often. However, since SSB is required for a UE to access the cell, this may increase delays in accessing the cell. Furthermore, since the delay between successive SSB burst set transmissions is greater, more UEs may have entered the cell since the last SSB burst set transmission and therefore may attempt to detect the same SSB. After this, the UEs will attempt to receive SIB1 and then perform initial access. The UEs will then try to transmit PRACH. The PRACH collision rate is likely to increase due to the increased number of UEs.

[0148] As another example, if the period between successive transmissions of SIB 1 in a periodic SIB 1 transmission is increased, this will improve network energy savings because the gNB transmits SIB 1 less often. However, since SIB1 is required for a UE to access the cell, this may increase delays in accessing the cell. Furthermore, since the delay between successive SIB1 transmissions is greater, more UEs may have entered the cell since the last SIB 1 transmission and therefore may attempt to detect the same SIB 1. After this, the UEs will attempt to perform initial access. The UEs will then try to transmit PRACH. The PRACH collision rate is likely to increase due to the increased number of UEs.

[0149] As another example, if the periodicity of PRACH resources is adapted to increase the period between PRACH resources (for example, RACH occasions), then network energy saving is improved because the gNB has to be awake less often to monitor the PRACH resources. However, after a UE receives SIB1, it will have to wait longer before it can transmit PRACH due to the increased period. Furthermore, since the period is increased, the likelihood of other UEs in the cell attempting to use the same PRACH resources to transmit PRACH is increased. Therefore, the PRACH collision rate is likely to increase. Accordingly, adapting common signals / channels for network energy saving purposes may lead to increased delays and collision rates (and therefore communications resource wastage) in wireless communications networks. A better balance is needed between obtaining network energy savings and communications efficiency in wireless communications network.

[0150] There is therefore a need for improved methods, communications devices and infrastructure equipment which can address at least some of the problems identified above.

[0151] Additional PRACH Resources for NES communications devices

[0152] Figure 13 shows a part schematic, part message flow diagram representation of a wireless communications system in accordance with example embodiments. The wireless communications system comprises an NES communications device 62 (e.g. an NES UE), a non-NES communications device 66 (such as a non-NES UE) and infrastructure equipment 64 of a wireless communications network. The non-NES communication device 66 is a communications device which does not support NES functions.

[0153] The NES communications device 62 comprises a transceiver 62. 1 (or transceiver circuitry) and a controller 62.2 (or controller circuitry). The non-NES communications device 66 comprises a transceiver

[0154] 66.1 (or transceiver circuitry) and a controller 66.2 (or controller circuitry). The infrastructure equipment comprises a transceiver 64. 1 (or transceiver circuitry) and a controller 64.2 (or controller circuitry). The transceivers 62.1, 64.1, 66.1 are configured to transmit and receive signals. The transceivers 62.1, 64.1,

[0155] 66. 1 (or transceiver circuitry) may each comprise a separate transmitter or receiver (or separate transmitter and receiver circuitry), or the transceivers 62. 1, 64.1, 66. 1 (or transceiver circuitry) may each comprise a device (or circuitry) configured to perform both transmission and reception. Each of the controllers 62.2, 64.2, 66.2 may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc.

[0156] The infrastructure equipment 64 provides a cell for one or more communications devices in the cell. In the example of Figure 13, the NES communications device 62 and the non-NES communications device 66 are in the cell.

[0157] As shown in Figure 13, the controller 64.2 of the infrastructure equipment 64 controls the transceiver 64.1 of the infrastructure equipment to transmit 68 one or more synchronisation signal blocks (SSBs) in the cell. Each of the one or more SSBs comprise a master information block (MIB). As shown in Figure 13, the controller 62.2 of the NES communications device 62 controls the transceiver 62.1 to receive the one or more SSBs and the controller 66.2 of the non-NES communications device 66 controls the transceiver

[0158] 66.1 to receive the one or more SSBs.

[0159] As shown in Figure 13, the controller 64.2 of the infrastructure equipment 64 controls the transceiver 64.1 of the infrastructure equipment 64 to transmit 70 one or more SIBs in the cell of a first type. Each of the one or more SIBs of the first type comprise an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH. Each MIB in the one or more SSBs comprises information required to decode the one or more SIBs of the first type.

[0160] In some embodiments, the first PRACH resources are for use by NES communications devices and non- NES communications devices in the cell to transmit PRACH. In some embodiments, the first PRACH resources are reserved for use by non-NES communications devices in the cell to transmit PRACH. As shown in Figure 13, the controller 62.2 of the NES communications device 62 controls the transceiver

[0161] 62.1 to receive the one or more SIBs and the controller 66.2 of the non-NES communications device 66 controls the transceiver 66. 1 to receive the one or more SIBs. The indication of the first PRACH resources may indicate parameters of the PRACH resources such as a location of the PRACH resources in time and / or frequency. In cases where the first PRACH resources are periodic, the indication of the first PRACH resources may comprise a PRACH configuration index, for example.

[0162] The one or more SIBs of the first type transmitted by the infrastructure equipment 64 may be referred to as “system information block type 1 (SIB1)”. Indeed, example embodiments will be described below with reference to SIB1. However, example embodiments are not limited to the SIB1 currently defined in 3GPP specifications and are equally applicable to any future SIB which comprises an indication of PRACH resources for transmitting PRACH. Therefore, although example embodiments will refer specifically to SIB1, it should be understood that the present disclosure is not so limited and any SIB comprising an indication of PRACH resources for transmitting PRACH may be used.

[0163] As shown in Figure 13, the controller 64.2 of the infrastructure equipment 64 controls the transceiver 64.1 of the infrastructure equipment 64 to transmit 72 an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH. As shown in Figure 13, the controller 62.2 of the NES communications device 62 controls the transceiver 62.1 to receive the indication of the additional PRACH resources.

[0164] In some embodiments, the indication of the additional PRACH resources comprises information identifying a configuration of the additional PRACH resources in time and / or frequency. For example, the indication of the additional PRACH resources may indicate parameters of the PRACH resources such as a location of the PRACH resources in time and / or frequency. In some embodiments, the indication of the additional PRACH resources comprises information identifying a configuration of RACH occasions in time and / or frequency. In some embodiments, the indication of the additional PRACH resources may indicate a subset of preambles that are configured for the additional PRACH resources. In cases where the additional PRACH resources are periodic, the indication of the additional PRACH resources may comprise a PRACH configuration index, for example. In some embodiments, the transmission of the information identifying the configuration of the additional PRACH resources may be a broadcast in the cell.

[0165] In some embodiments, the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in system information. For example, the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH may be transmitted in each of the one or more SIB Is. In other words, in some embodiments, the indication of both the first PRACH resources and the additional PRACH resources are transmitted in the same one or more SIB Is. Therefore, in some embodiments, transmissions 70 and 72 are the same transmission. In some such embodiments, the indication of the first PRACH resources and the indication of the additional RACH resources are indicated by information in the SIB Is indicating a PRACH resource configuration which comprises both the first PRACH resources (for transmitting PRACH) and the additional PRACH resources (reserved for NES communications devices to transmit PRACH). However, in other embodiments, transmissions 70 and 72 are separate transmissions. For example, the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH may be transmitted in another type of SIB (such as any of SIB2 to SIB18). Therefore, in Figure 13 transmissions 70 and 72 are shown as separate transmission for ease of explanation only. In some embodiments, the additional PRACH resources are periodic. In some embodiments, the additional PRACH resources may appear between the first PRACH resources in time. For example, the additional PRACH resources may be a periodic configuration of PRACH resources offset in time relative to the first PRACH resources such that one or more instances of the additional PRACH resources appear between instances of the first PRACH resources in time. In some embodiments, the additional PRACH resources may have a smaller period than the first PRACH resources.

[0166] By transmitting, in the cell an indication of additional PRACH resources reserved for use by NES communications devices to transmit PRACH, communications efficiency can be improved. For example, NES communications devices may use the first PRACH resources, or NES communications devices may use the additional PRACH resources to transmit PRACH. Non-NES communications devices may only use the first PRACH resources. Since there are additional PRACH resources, there may be a reduced delay for a given communications device to access the cell because it is more likely the next PRACH resource will not be far away in time. Furthermore, since there are additional PRACH resources, there may be a reduced collision rate because there are more PRACH resources available in which communications devices can transmit PRACH.

[0167] In accordance with example embodiments, when the infrastructure equipment transmits the indication of the additional PRACH resources, the additional PRACH resources may already be activated for use by NES communications devices to transmit PRACH. In such embodiments, NES communications devices may make use of the additional PRACH resources to transmit PRACH immediately after the indication is received. In such embodiments, the infrastructure equipment may transmit, at a later time, a deactivation indication indicating that the additional PRACH resources have been deactivated. If the additional PRACH resources have been deactivated, they can no longer be used by NES communications devices to transmit PRACH while they are deactivated. At an even later time, the infrastructure equipment may transmit an activation signal indicating that the additional PRACH resources have been activated. In this case, the activation signal may be regarded as a “reactivation signal” because the additional PRACH resources are re-activated. NES communications devices may use the additional PRACH resources to transmit PRACH while they are activated. Whilst the additional PRACH resources are deactivated, the infrastructure equipment does not have to monitor them for PRACH - it can therefore go to sleep and save power.

[0168] In accordance with example embodiments, when the infrastructure equipment transmits the indication of the additional PRACH resources, the additional PRACH resources may be deactivated for use by NES communications devices to transmit PRACH. At a later time, the infrastructure equipment may transmit an activation signal indicating that the additional PRACH resources have been activated. In such embodiments, the infrastructure equipment may transmit, at an even later time, a deactivation indication indicating that the additional PRACH resources have been deactivated.

[0169] In some embodiments, the deactivation indication is transmitted in response to the infrastructure equipment detecting that a number of NES communications devices in the cell is below a pre-defined threshold. This recognises that the probability of delay to accessing the cell and of collision between communications devices in PRACH is lower if the number of NES communications devices in the cell is lower. Furthermore, the activation of PRACH resources may decrease network energy savings because the infrastructure equipment may have to monitor more resources for PRACH. Therefore, a balance between network energy savings and communications efficiency can be achieved in such embodiments.

[0170] In some embodiments, the activation indication may be transmitted in response to the infrastructure equipment detecting a collision between PRACHs at the infrastructure equipment. This indicates that communications efficiency is being adversely affected and, therefore, to improve communications efficiency additional PRACH resources are activated.

[0171] In some embodiments, the activation indication is transmitted in response to the infrastructure equipment detecting that a number of NES communications devices in the cell is above a predefined threshold. This recognises that the probability of delay to accessing the cell and of collision between PRACHs is increased if the number of NES communications devices in the cell is higher. Furthermore, the deactivation of PRACH resources may increase network energy savings because the infrastructure equipment may have to monitor fewer resources for PRACH. Therefore, a balance between network energy savings and communications efficiency can be achieved in such embodiments.

[0172] In some embodiments, the deactivation indication is transmitted in response to the infrastructure equipment not detecting a collision between PRACHs at the infrastructure equipment for a predefined time period. This indicates that communications efficiency is not being adversely affected and, therefore, to improve network energy savings, the additional PRACH resources are deactivated.

[0173] The activation indication and / or the deactivation indication may be broadcast in the cell by the infrastructure equipment, for example.

[0174] In some embodiments, the indication of additional PRACH resources is transmitted in response to an adaptation performed by the infrastructure equipment. The adaptation may comprise, for example:

[0175] — adapting a periodic transmission of an SSB burst set to increase the period between successive transmissions of the SSB burst sets,

[0176] — adapting a periodic transmission of the SIB1 to increase the period between successive transmissions of the SIB1, and / or

[0177] — adapting a periodic configuration of RACH occasions (ROs) in the first PRACH resources to increase the period of the periodic configuration of the ROs in the first PRACH resources.

[0178] As explained previously, such adaptations may improve network energy saving, but may also decrease communications efficiency. By transmitting the indication of the additional PRACH resources in response to the adaptation, this recognises that the additional PRACH resources may be needed to improve communications efficiency. It will be appreciated that, in some embodiments, such adaptations are not performed by the infrastructure equipment. For example, the infrastructure equipment may be initially configured to transmit periodic SSB burst sets with a large period between successive transmissions, to transmit periodic SIB 1 with a large period between successive transmissions and / or the configuration of ROs in the first PRACH resources may be such that period of the configuration of ROs is large. In such cases, the problems due to increased delay to access the cell and increased PRACH collisions still arise, even though no adaptation was performed by the infrastructure equipment.

[0179] For ease of explanation, embodiments may be described with reference to UEs and gNBs. However, the present disclosure is not so limited, and references to “UE” may be replaced with “communications device” and references to “gNB” may be replaced with “infrastructure equipment of a wireless communications network”.

[0180] Furthermore, references to “NES UEs” are UEs which support one or more NES functions and “NES cells” are cells which support one or more NES functions.

[0181] NES functions may comprise one or more of the following: (1). Supporting anchor SSB with intervals between broadcasts with a periodicity of more than

[0182] 20 ms on an initial bandwidth part. An NES UE may be configured to receive SSBs with intervals between broadcasts with a periodicity of more than 20 ms on an initial bandwidth part. By contrast, a non-NES UE assumes that SSB is broadcast with a periodicity of 20 ms or less on the initial bandwidth part.

[0183] (2). Supporting on-demand SSB. An NES UE may be configured to request and receive on- demand SSBs. By contrast, a non-NES UE assumes SSB is always-on and periodically transmitted.

[0184] (3). Supporting on-demand SIB 1. An NES UE is configured to request and receive on- demand SIB 1. By contrast, a non-NES UE assumes SIB 1 is periodically transmitted with a periodicity of 160 ms.

[0185] In some embodiments, an NES UE is defined as a UE which supports: at least NES function (1), at least NES function (2), at least NES function (3), at least NES functions (1) and (2), at least NES functions (1) and (3), at least NES functions (2) and (3), at least NES functions (1), (2) and (3).

[0186] Non-NES UEs are UEs which do not support the NES functions supported by the NES UEs.

[0187] MIB

[0188] Figure 14 illustrates the fields of an existing MIB which is transmitted in a cell. As will be appreciated from Figure 14, there is a spare bit 92 in the MIB.

[0189] In some embodiments, the spare bit 92 may indicate that additional PRACH resources have been reserved for use by NES UEs to transmit PRACH. In such embodiments, SIB 1 may be used to indicate the additional PRACH resources. Based on the indication in the spare bit 92, the communications device searches SIB1 for the additional PRACH resources. Such embodiments improve communications efficiency because an existing signal is adapted to provide the indication and a new signal is not required to be transmitted.

[0190] In some embodiments, where the indication of additional PRACH resources is transmitted in response to an adaptation performed by the infrastructure equipment, the spare bit 92 in the MIB may indicate that an adaptation has been performed by the infrastructure equipment. Such embodiments improve communications efficiency because an existing signal is adapted to provide the indication and a new signal is not required to be transmitted.

[0191] In some embodiments, the NES communications device may store the indication of the additional PRACH resources. For example, the NES communications may be in a first cell provided by a first infrastructure equipment which transmits the indication of the additional PRACH resources to the NES communications device. Then, the NES communications device stores the indication of the additional PRACH resources. Then, when the NES communications device moves to a second cell provided by a second infrastructure equipment of the wireless communications network, the NES communications device may determine an area ID of the second cell provided by the other infrastructure equipment. The first and / or second infrastructure equipment may transmit the area ID to the NES communications device in system information (such as in SIB1 or SIB2-18), for example.

[0192] Based on the area ID, the NES communications device may determine that the additional PRACH resources are also reserved for use by NES communications devices in the second cell provided by the second infrastructure equipment. For example, the NES communications device may be preconfigured to know that infrastructure equipment with the same area ID have the same additional PRACH resources. In cases where both the first and second infrastructure equipment transmit the area ID to the NES communications device, the NES communications device may compare the area ID transmitted by the first and second infrastructure equipment and, if the area ID received from the first and second infrastructure equipment is the same, the NES communications device determines that the additional PRACH resources are also reserved for use by NES communications devices in the second cell provided by the second infrastructure equipment. The NES communications device may then use the stored additional PRACH resources from the first cell to transmit PRACH in the second cell provided by the second infrastructure equipment. Such embodiments improve communications efficiency because the NES communications device does not need to receive an indication of additional PRACH resources every time it changes cell.

[0193] In some embodiments, the infrastructure equipment determines an amount of the additional PRACH resources is determined based on the period between successive SSB burst set transmissions, the period between successive SIB1 transmissions and / or the period of the periodic configuration of the PRACH resources. In such embodiments, the amount of additional PRACH resources is greater for a greater period between successive SSB burst set transmissions, a greater period between successive SIB 1 transmissions and / or a greater period of the periodic configuration of the PRACH resources. In other words, the amount of PRACH resources correlates with the periodicity of the SSB burst set, SIB1 or the PRACH configuration. In some embodiments, a greater amount of PRACH resources means a greater number of sets of additional PRACH resources. For example, if the SSB burst set is of 40ms periodicity, the infrastructure equipment may reserve one additional set of PRACH resources, and, when the SSB burst set is of 80ms periodicity, the infrastructure equipment may reserve two additional sets of PRACH resources. Such embodiments recognise that, the greater the period, the more likely increased delays to the cell and increased PRACH collisions are to occur.

[0194] PRACH Resource Selection

[0195] In some embodiments, the NES communications device may randomly select between the first PRACH resources and the additional PRACH resources for transmitting a PRACH to the infrastructure equipment. This simplifies processing for the NES communications device.

[0196] In some embodiments, the NES communications device may transmit a PRACH to the infrastructure equipment using the first PRACH resources. The NES communications device may determine that the infrastructure equipment did not correctly receive the PRACH. In response, the NES communications device may transmit a PRACH in the additional PRACH resources. Such embodiments are useful for implicitly informing the infrastructure equipment whether the additional PRACH resources are currently being used to avoid PRACH collisions, and therefore allow the infrastructure equipment to determine whether to keep the additional PRACH resources activated. The NES communications device may determine that the infrastructure equipment did not correctly receive the PRACH because, for example, the NES communications device did not receive a response to the PRACH transmitted in the first PRACH resources or the NES communications device receives a random access response with backoff indication from the infrastructure equipment.

[0197] As explained above, the first PRACH resources may be for use by NES communications devices and non- NES communications devices. However, in some embodiments, the infrastructure equipment may reserve the first PRACH resources for use exclusively by non-NES communications devices. In such embodiments, only NES communications devices use the additional PRACH resources and only non- NES communications devices use the first PRACH resources. This can improve communications efficiency by decreasing delay for communications devices to access the cell and decrease the probability of PRACH collisions. Activation / Deactivation of additional PRACH resources

[0198] As mentioned previously, the indication of the additional PRACH resources may be transmitted in system information such as SIB1 or another type of SIB. However, when there are few NES communications devices in the cell which can utilise the additional PRACH resources, the benefit of improved communications efficiency by having the additional PRACH resources may be offset by the reduction in network energy savings caused by having the additional PRACH resources. In accordance with example embodiments, the additional PRACH resources may be activated or deactivated for use by NES communications devices to transmit PRACH. When the additional PRACH resources are activated, they can be used by NES communications devices to transmit PRACH. When the additional PRACH resources are deactivated, they cannot be used to transmit PRACH. The infrastructure equipment may transmit an activation indication or deactivation indication in the cell to indicate that the additional PRACH resources have been activated or deactivated for use by NES communications devices to transmit PRACH respectively.

[0199] The use of activation or deactivation indications can allow the infrastructure equipment to inform communications devices that the additional PRACH resources are activated or deactivated without having to reconfigure the additional PRACH resources every time they are required. In existing systems, any change to a PRACH resource configuration requires a system information update which takes a relatively long amount of time. Therefore, the use of activation and / or deactivation indications can provide a more efficient way of informing communications devices of which PRACH resources are available for use.

[0200] Group Common Downlink Control Information (GC DCI)

[0201] In some embodiments, the activation indication and / or deactivation indication may be transmitted in GCDCI. This is particularly useful for communications devices in the idle or inactive mode. In some embodiments, a DCI format 1 0 with a System Information Radio Network Temporary Identifier (SI- RNTI) may comprise the activation and / or deactivation indication. In some embodiments, the activation and / or deactivation indication is provided by a reserved bit in the DCI format 1 0. Such embodiments can provide communications efficiency because they involve re-using existing signals for a different purpose.

[0202] In some embodiments, a new RNTI transmitted by the infrastructure equipment provides the activation and / or deactivation indication.

[0203] Msg2 / MsgB

[0204] In some embodiments, the activation indication and / or deactivation indication may be transmitted in msg2 or msgB of a PRACH procedure. For example, the activation and / or deactivation indication may be transmitted in DCI format 1 0 with RA-RNTI / MsgB-RNTI or RAR / MsgB MAC. In some embodiments, the activation and / or deactivation indication may be indicated by a backoff indicator in msg2 or msgB. For example, the backoff indicator may indicate to the communications device that a PRACH collision has occurred and, in response, the communications device determines that the additional PRACH resources have been activated. In some embodiments, the communications may implicitly determine that the additional PRACH resources have been deactivated if no response is received to a msg2 or msgB transmitted by the communications device. If no response is received, the NES communications device may select a PRACH resource from the first PRACH resources for transmitting its next PRACH. In this case, it is not necessary to execute power ramping for PRACH because this failure is not caused by low received power but by the infrastructure equipment sleeping during the additional PRACH resources since they are deactivated. The activation indication and / or deactivation indication via msg2 or msgB of a PRACH procedure may be transmitted in addition to an activation indication and / or deactivation indication via a broadcast message such as GC-DCI, Paging Message, and SIB 1 without update notification. This may be beneficial especially if communications devices miss (i.e. do not receive) the activation and / or deactivation indication transmitted by the broadcast message before selecting PRACH resources for transmitting a PRACH or the infrastructure equipment changes the activation status of the additional PRACH resources between PRACH reception and RAR transmission.

[0205] Paging Message

[0206] In some embodiments, the activation and / or deactivation may be transmitted in a paging message. For example, the activation and / or deactivation indication may be comprised in DCI format 1 0 with Paging Radio Network Temporary Identifier (P-RNTI) by using a reserved bit, or a field of Short Message, or in a PDSCH scheduled by a paging DCI.

[0207] SIB 1 without update notification

[0208] In some embodiments, where the additional PRACH resources are indicated in SIB1, the NES communications device may check / read every periodic transmission of SIB 1 for the indication of the additional PRACH resources. In some embodiments, if the NES communications device detects the indication of the additional PRACH resources in the SIB1, then the NES communications device assumes that the additional PRACH resources have been activated. In such embodiments, the NES communications device may not receive any paging message which inform the NES communications device to read updated SIB1, but the NES communications device may monitor each SIB1 transmission without being prompted. The periodicity of the SIB1 may be 160 ms for example. In such cases, the NES communications device would be checking for the indication of the additional PRACH resources every 160 ms.

[0209] In some embodiments, the NES communications device may check or read SIB1 before transmitting PRACH. For example, the NES communications device may determine that it is to transmit PRACH and, in response, the NES communications device may read one or more SIB Is received from the infrastructure equipment. The NES communications device can thus determine the first PRACH resources and additional PRACH resources indicated in the SIB Is. In such embodiments the infrastructure equipment may update the first and / or additional PRACH resources without notifying the NES communications device other than via the SIB Is.

[0210] Connected Mode Communications Devices

[0211] In some embodiments, the activation and / or deactivation indication is transmitted in a Physical Downlink Control Channel (PDCCH) order, a Medium Access Control (MAC) Control Element (CE), or a radio resource control signal, or an LI signal. Such embodiments are particularly useful when the NES communications device is in connected mode.

[0212] Modifying SSB to RO association in PRACH resources

[0213] As explained in the section on SSB-RO association above, each SSB may be associated with one or more RACH Occasions (ROs). Each RO is associated with a plurality of preambles and each SSB is further associated with one or more of the preambles.

[0214] In accordance with example embodiments, the SSB-RO association may be adapted to reduce the likelihood of PRACH collisions. For example, the value of the parameter ssb-perRACH-occasion may currently be set to one of { 1 / 8, ! , 'A, 1, 2, 4, 8, 16}. In accordance with example embodiments, the value of this parameter may be decreased, for example, to 1 / 16, meaning that an SSB is associated with 16 ROs. Since the SSB is associated with a greater number of ROs, the probability of PRACH collision is decreased. Furthermore, as mentioned above, the value of parameter CB-preamblesperSSB may be set to a greater number than is currently used. For example, the value of parameter CB-preamblesperSSB may be set to 32, meaning that each SSB is associated with 32 preambles. By increasing the number of preambles with which each SSB is associated, the probability of PRACH collisions is decreased. Embodiments where the number of ROs associated with each SSB is increased and / or where the number of preambles associated with each SSB is increased may be applied to the first PRACH resources. In other words, the ROs are ROs of the first PRACH resources. In such embodiments, the infrastructure equipment may or may not configure the additional PRACH resources for the NES communications devices. Alternatively, or in addition, embodiments where the number of ROs associated with each SSB is increased and / or where the number of preambles associated with each SSB is increased may be applied to the additional PRACH resources. In other words, the ROs may comprise ROs from the first PRACH resources and / or ROs from the additional PRACH resources.

[0215] Partitioning First PRACH resources

[0216] In some embodiments, the infrastructure equipment may partition the first PRACH resources so that a portion of the first PRACH resources are reserved for NES communications devices and another portion of the first PRACH resources are reserved for non-NES communications devices. This allows the infrastructure equipment network to understand PRACH load transmitted from NES UE. By partitioning the PRACH resources, the infrastructure equipment can infer the number of idle mode NES UEs in the cell. Then, based on the number of idle mode NES UEs in the cell, the infrastructure equipment can configure the additional PRACH resources. In such embodiments, the infrastructure equipment may or may not configure the additional PRACH resources for the NES communications devices.

[0217] Methods of operating communications devices and infrastructure equipment in accordance with example embodiments

[0218] Figure 15 is a flow diagram illustrating a method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell in accordance with example embodiments. The method starts in step SI.

[0219] In step S2, the method comprises transmitting one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB).

[0220] In step S3, the method comprises transmitting one or more system information blocks (SIBs) of a first type in the cell. Each of the one or more SIBs of the first type comprises an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH. Each MIB in the one or more SSBs comprises information required to decode the one or more SIBs of the first type.

[0221] In step S4, the method comprises transmitting, in the cell, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

[0222] The method ends in step S5.

[0223] In some embodiments, the indication of both the first PRACH resources and the additional PRACH resources are transmitted in the same one or more SIB Is. Therefore, in some embodiments, steps S3 and S4 are referring to the same transmission and may therefore be regarded as one step. However, in other embodiments, steps S3 and S4 are referring to different transmissions. For example, the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH may be transmitted in another type of SIB (such as any of SIB2 to SIB 18 or any newly defined SIB). Therefore, in Figure 15 steps S3 and S4 are shown as separate steps for ease of explanation only. In some embodiments, the method may further comprise a step of transmitting an activation indication in the cell, The activation indication indicates that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices.

[0224] In some embodiments, the method may further comprise a step of transmitting a deactivation indication in the cell. The deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices.

[0225] Figure 16 is a flow diagram illustrating a method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment. The method starts in step Si l.

[0226] In step S12, the method comprises receiving one or more synchronisation signal blocks (SSBs). Each SSB comprises a master information block (MIB),

[0227] In step S 13, the method comprises receiving one or more system information blocks (SIBs) of a first type. Each of the one or more SIBs of the first type comprise an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH. Each MIB in the one or more SSBs comprises information required to decode the one or more SIBs of the first type.

[0228] In step S14, the method comprises receiving, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

[0229] The method ends in step S15.

[0230] In some embodiments, the indication of both the first PRACH resources and the additional PRACH resources are transmitted in the same one or more SIB Is. Therefore, in some embodiments, steps S13 and S14 are referring to the same transmission and may therefore be regarded as one step. However, in other embodiments, steps S13 and S14 are referring to different transmissions. For example, the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH may be transmitted in another type of SIB (such as any of SIB2 to SIB 18 or any newly defined SIB). Therefore, in Figure 16 steps S13 and S14 are shown as separate steps for ease of explanation only.

[0231] In some embodiments, the method may further comprise a step of transmitting an activation indication in the cell, The activation indication indicates that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices.

[0232] In some embodiments, the method may further comprise a step of transmitting a deactivation indication in the cell. The deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices.

[0233] As will be appreciated by a person skilled in the art, the relative order of the steps in Figure 15 and Figure 16 may be interchanged in any logical order.

[0234] Those skilled in the art would further appreciate that such infrastructure equipment and / or communications devices as herein defined may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. It would be further appreciated by those skilled in the art that such infrastructure equipment and communications devices as herein defined and described may form part of communications systems other than those defined by the present disclosure.

[0235] The following numbered paragraphs provide further example aspects and features of the present technique:

[0236] Paragraph 1. A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the method comprising transmitting one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmitting one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and transmitting, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

[0237] Paragraph 2. A method according to paragraph 1, wherein each MIB in the one or more SSBs comprises an indication that additional PRACH resources have been reserved for use by NES communications devices to transmit PRACH, and each of the one or more SIBs of the first type comprise the indication of the additional PRACH resources reserved for use by NES communications devices to transmit PRACH.

[0238] Paragraph 3. A method according to paragraph 2, wherein the indication that the additional PRACH resources have been reserved for use by NES communications devices to transmit PRACH is indicated by a spare bit in each of MIB in the one or more SSBs.

[0239] Paragraph 4. A method according to any one of paragraphs 1 to 3, comprising transmitting an activation indication in the cell in response to one or more activation conditions being met, the activation indication indicating that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices.

[0240] Paragraph 5. A method according to paragraph 4, wherein the one or more activation conditions comprise a condition that the infrastructure equipment detects that the number of NES communications devices in the cell is above a predefined threshold.

[0241] Paragraph 6. A method according to paragraph 5, wherein the one or more activation conditions comprise a condition that the infrastructure equipment detects a collision between PRACHs at the infrastructure equipment.

[0242] Paragraph 7. A method according to any of paragraphs 4 to 6, wherein the activation indication is transmitted in group common downlink control information (DCI).

[0243] Paragraph 8. A method according to any of paragraphs 4 to 6, wherein the activation indication is transmitted in a paging message.

[0244] Paragraph 9. A method according to any of paragraphs 7 to 8, wherein another activation indication indicating that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices, or a deactivation indication indicating that the activated additional PRACH resources are now deactivated for the transmission of PRACH by NES communications devices, is transmitted in a message 2 (msg2) or message B (msgB) of a PRACH procedure.

[0245] Paragraph 10. A method according to any of paragraphs 4 to 6, wherein the activation indication is transmitted in a Physical Downlink Control Channel (PDCCH) order, a Medium Access Control (MAC) Control Element (CE), or a radio resource control (RRC) signal, or an LI signal.

[0246] Paragraph 11. A method according to any of paragraphs 4 to 10, wherein an update of the one or more SIBs of the first type is not transmitted in response to the one or more activation conditions being met. Paragraph 12. A method according to any of paragraphs 1 to 11, comprising transmitting a deactivation indication in the cell in response to one or more deactivation conditions being met, the deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices. Paragraph 13. A method according to paragraph 12, wherein the one or more deactivation conditions comprise a condition that the infrastructure equipment detects that the number of NES communications devices in the cell is below a predefined threshold.

[0247] Paragraph 14. A method according to paragraph 12, wherein the one or more deactivation conditions comprise a condition that the infrastructure equipment does not detect a collision between PRACHs at the infrastructure equipment for a predefined time period.

[0248] Paragraph 15. A method according to any of paragraphs 12 to 14, wherein the deactivation indication is transmitted in group common downlink control information (DCI).

[0249] Paragraph 16. A method according to any of paragraphs 12 to 14, wherein the deactivation indication is transmitted in a paging message.

[0250] Paragraph 17. A method according to any of paragraphs 15 to 16, wherein another deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices, or an activation indicating that the deactivated additional PRACH resources are now activated for the transmission of PRACH by NES communications devices, is transmitted in a message 2 (msg2) or message B (msgB) of a PRACH procedure.

[0251] Paragraph 18. A method according to any of paragraphs 12 to 14, wherein the deactivation indication is transmitted in a Physical Downlink Control Channel (PDCCH) order, a Medium Access Control (MAC) Control Element (CE), or a radio resource control signal, or an LI signal.

[0252] Paragraph 19. A method according to any of paragraphs 12 to 18, wherein an indication of an update to the one or more SIBs of the first type is not transmitted in response to the one or more deactivations conditions being met.

[0253] Paragraph 20. A method according to any preceding paragraph, wherein the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in each of the one or more SIBs of the first type.

[0254] Paragraph 21. A method according to paragraph 20, wherein the method comprises transmitting an updated one or more SIBs of the first type, wherein each of the one or more SIBs of the first type comprise an indication of updated first PRACH resources for transmitting RACH and / or updated additional RACH resources for NES communications devices in the cell to transmit RACH. Paragraph 22. A method according to any preceding paragraph, wherein the indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in an SIB of another type.

[0255] Paragraph 23. A method according to any preceding paragraph, wherein the indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in a Radio Resource Control Signal (RRC), a Medium Access Control (MAC) Control Element (CE), or an LI signal.

[0256] Paragraph 24. A method according to any preceding paragraph, wherein each of the one or more SIBs of the first type is a system information block type 1 (SIB 1).

[0257] Paragraph 25. A method according to any preceding paragraph, wherein the additional PRACH resources comprise a periodic configuration of RACH Occasions (ROs).

[0258] Paragraph 26. A method according to paragraph 25, wherein the first PRACH resources comprise a periodic configuration of ROs, and the period of the periodic configuration of the ROs in the additional PRACH resources is less than the period of the periodic configuration of the ROs in the first PRACH resources.

[0259] Paragraph 27. A method according to any preceding paragraph, wherein the first PRACH resources for transmitting PRACH are for use by NES communications devices and non-NES communications devices in the cell to transmit PRACH

[0260] Paragraph 28. A method according to any preceding paragraph, wherein the first PRACH resources for transmitting PRACH are reserved for use by non-NES communications devices to transmit PRACH.

[0261] Paragraph 29. A method according to any of paragraphs 1 to 28, wherein the transmission of the one or more SSBs is an adaptation of a previous periodic transmission of an SSB burst set, the adaptation comprising increasing the period between successive transmissions of the SSB burst set, wherein the indication of additional PRACH resources is transmitted in response to the adaptation. Paragraph 30. A method according to any of paragraphs 1 to 29, wherein the transmission of the one or more SIBs of the first type is an adaptation of a previous periodic transmission of an SIB of the first type, the adaptation comprising increasing the period between successive transmissions of the SIB of the first type, wherein the indication of additional PRACH resources is transmitted in response to the adaptation.

[0262] Paragraph 31. A method according to any of paragraphs 1 to 30, wherein the first PRACH resources comprise a periodic configuration of RACH occasions (ROs), and the indication of additional PRACH resources is transmitted in response to an adaptation performed by the infrastructure equipment, the adaptation comprising adapting the periodic configuration of ROs in the first PRACH resources to increase the period of the periodic configuration of ROs in the first PRACH resources.

[0263] Paragraph 32. A method according to any of paragraphs 29 to 31, wherein each MIB in the one or more SSBs comprises an indication that the adaptation of the previous transmission of the SSB burst sets has been performed by the infrastructure equipment, the adaptation of the previous transmission of the SIB of the first type has been performed by the infrastructure equipment, and / or the adaptation of the periodic configuration of ROs in the first PRACH resources has been performed by the infrastructure equipment.

[0264] Paragraph 33. A method according to paragraph 32, wherein a spare bit in each MIB in the one or more SSBs provides the indication that the adaptation of the previous transmission of the SSB burst set has been performed by the infrastructure equipment, the adaptation of the previous transmission of the SIB of the first type has been performed by the infrastructure equipment, and / or the adaptation of the periodic configuration of ROs in the first PRACH resources has been performed by the infrastructure equipment.

[0265] Paragraph 34. A method according to any of paragraphs 29 to 33, wherein the first PRACH resources comprise a periodic configuration of RACH occasions (ROs), each RO being associated with a plurality of preambles, each of the one or more SSBs is associated with one or more of the ROs and associated with one or more of the preambles in the one or more ROs that the SSB is associated with, and the method comprises, in response to the adaptation of the previous transmission of the SSB burst set, the adaptation of the previous transmission of the SIB of the first type, and / or the adaptation of the periodic configuration of ROs in the first PRACH resources, increasing the number of ROs associated with each of the one or more SSBs, and / or increasing the number of preambles associated with each of the one or more SSBs, and transmitting, in one or more SIBs of the first type after the increase in the number of ROs associated with each of the one or more SSBs and / or the increased in the number of preambles associated with each of the one or more SSBs, an indication of the increased number of ROs and / or the increased number of preambles associated with each of the one or more SSBs.

[0266] Paragraph 35. A method according to any of paragraphs 1 to 34, wherein the transmission of the one or more SSBs is a periodic transmission of an SSB burst set, and an amount of the additional PRACH resources is determined based on the period between successive transmissions of the SSB, wherein the greater the period between successive transmission of the SSB burst set, the greater the amount of the additional PRACH resources.

[0267] Paragraph 36. A method according to any of paragraphs 1 to 35, wherein the transmission of the one or more SIBs of the first type is a periodic transmission of an SIB of the first type, and an amount of the additional PRACH resources is determined based on the period between successive transmissions of the SIB of the first type, wherein the greater the period between successive transmission of the SIB of the first type, the greater the amount of the additional PRACH resources.

[0268] Paragraph 37. A method according to any of paragraphs 1 to 36, wherein the first PRACH resources comprise a periodic configuration of RACH occasions (ROs), and an amount of the additional PRACH resources is determined based on the period of the periodic configuration of ROs in the first PRACH resources, wherein the greater the period of the periodic configuration of ROs in the first PRACH resources, the greater the amount of the additional PRACH resources. Paragraph 38. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), receiving one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and receiving, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

[0269] Paragraph 39. A method according to paragraph 38 wherein the first PRACH resources for transmitting PRACH are for use by NES communications devices and non-NES communications devices in the cell to transmit PRACH

[0270] Paragraph 40. A method according to paragraph 39, comprising randomly selecting between the first PRACH resources and the additional PRACH resources for transmitting a PRACH to the infrastructure equipment.

[0271] Paragraph 41. A method according to paragraph 39 or paragraph 40, comprising transmitting a PRACH to the infrastructure equipment using the first PRACH resources, determining that the infrastructure equipment did not correctly receive the PRACH, and in response, transmitting a PRACH to the infrastructure equipment in the additional PRACH resources.

[0272] Paragraph 42. A method according to any of paragraphs 38 to 41, comprising receiving, from the infrastructure equipment, an activation indication, the activation indication indicating that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices.

[0273] Paragraph 43. A method according to any of paragraphs 38 to 41, comprising receiving, from the infrastructure equipment, a deactivation indication, the deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices

[0274] Paragraph 44. A method according to any of paragraphs 38 to 43, comprising transmitting a PRACH to the infrastructure equipment using the additional PRACH resources, determining that the additional PRACH resources have been deactivated for the transmission of PRACH because a reply to the PRACH was not received from the infrastructure equipment.

[0275] Paragraph 45. A method according to any of paragraphs 38 to 43, comprising storing the indication of the additional PRACH resources, moving to another cell provided by other infrastructure equipment of the wireless communications network, determining an area ID of the other cell provided by the other infrastructure equipment, and based on the area ID, determining that the additional PRACH resources are also reserved for use by NES communications devices in the other cell provided by the other infrastructure equipment. Paragraph 46. A method according to any of paragraphs 38 to 45, wherein the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is received in each of the one or more SIBs of the first type.

[0276] Paragraph 47. A method according to paragraph 46, comprising determining to transmit a PRACH, and in response, reading one or more of the SIBs of the first type received from the infrastructure equipment to determine the first PRACH resources and the additional PRACH resources, and transmitting the PRACH in the first PRACH resources or the additional PRACH resources.

[0277] Paragraph 48. A method according to paragraph 46 or paragraph 47, wherein the method comprises receiving an updated one or more SIBs of the first type, wherein each of the one or more SIBs of the first type comprise an indication of updated first PRACH resources for transmitting RACH and / or updated additional RACH resources for NES communications devices in the cell to transmit PRACH, and transmitting PRACH in the updated first PRACH resources or the updated additional PRACH resources. Paragraph 49. A method according to paragraph 48, comprising determining to transmit a PRACH, and in response, reading one or more of the updated SIBs of the first type received from the infrastructure equipment to determine the updated first PRACH resources and the updated additional PRACH resources, and transmitting the PRACH in the updated first PRACH resources or the updated additional PRACH resources.

[0278] Paragraph 50. A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the method comprising transmitting one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmitting one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

[0279] Paragraph 51. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving one or more synchronisation signal blocks (SSBs), each of the one or more SSBs comprising a master information block (MIB), receiving one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

[0280] Paragraph 52. A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the method comprising periodically transmitting a synchronisation signal block (SSB) burst set in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), periodically transmitting a system information block (SIB) of a first type in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by network energy saving (NES) communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each SSB instance in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and the method comprises increasing the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increasing a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and transmitting, in the cell, an indication of the increased number of ROs and / or the increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission. Paragraph 53. A method according to paragraph 52, wherein the increasing the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increasing a number of the preambles associated with each SSB in the periodic SSB burst set transmission is performed in response to the infrastructure equipment performing an adaptation, the adaptation comprising adapting the periodic SSB burst set transmission to increase the period between successive instances SSB burst sets in the periodic SSB burst set transmission, adapting the periodic transmission of the first type of SIB to increase the period between successive instances of the SIB of the first type in the periodic transmission of the first type of SIB, and / or adapting the periodic configuration of the PRACH resources to increase the period of the periodic configuration of the PRACH resources.

[0281] Paragraph 54. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving a synchronisation signal block (SSB) from a periodic SSB burst set transmission transmitted by the infrastructure equipment in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), receiving a system information block (SIB) of a first type periodically transmitted by the infrastructure equipment in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by NES communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type in the periodic SIB transmission, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each instance of the SSB in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and the method comprises receiving, from the infrastructure equipment, an indication of an increased number of ROs and / or increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

[0282] Paragraph 55. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), determining to transmit a Physical Random Access Channel (PRACH) and, in response, reading one or more system information blocks (SIBs) of a first type received from the infrastructure equipment to determine first PRACH resources for transmitting PRACH and additional PRACH resources reserved for use by NES communications devices to transmit PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and the method comprises transmitting the PRACH in the first PRACH resources or the additional PRACH resources. Paragraph 56. Infrastructure equipment for a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the infrastructure equipment comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and transmit, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

[0283] Paragraph 57. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to receive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and receive, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

[0284] Paragraph 58. Infrastructure equipment for a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the infrastructure equipment comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

[0285] Paragraph 59. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to receive one or more synchronisation signal blocks (SSBs), each of the one or more SSBs comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH. Paragraph 60. Infrastructure equipment for a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the infrastructure equipment comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to periodically transmit a synchronisation signal block (SSB) burst set in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), periodically transmit a system information block (SIB) of a first type in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by network energy saving (NES) communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each SSB instance in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller is configured in combination with the transceiver to increase the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increase a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and transmit, in the cell, an indication of the increased number of ROs and / or the increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

[0286] Paragraph 61. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to receive a synchronisation signal block (SSB) from a periodic SSB burst set transmission transmitted by the infrastructure equipment in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), receive a system information block (SIB) of a first type periodically transmitted by the infrastructure equipment in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by NES communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type in the periodic SIB transmission, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each instance of the SSB in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller is configured in combination with the transceiver to receive, from the infrastructure equipment, an indication of an increased number of ROs and / or increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission. Paragraph 62. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to receive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), determine to transmit a Physical Random Access Channel (PRACH) and, in response, read one or more system information blocks (SIBs) of a first type received from the infrastructure equipment to determine first PRACH resources for transmitting PRACH and additional PRACH resources reserved for use by NES communications devices to transmit PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein the controller is configured in combination with the transceiver to transmit the PRACH in the first PRACH resources or the additional PRACH resources.

[0287] Paragraph 63. Circuitry for Infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and transmit, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

[0288] Paragraph 64. Circuity for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to receive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and receive, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

[0289] Paragraph 65. Circuitry for Infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

[0290] Paragraph 66. Circuity for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to receive one or more synchronisation signal blocks (SSBs), each of the one or more SSBs comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

[0291] Paragraph 67. Circuitry for Infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to periodically transmit a synchronisation signal block (SSB) burst set in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), periodically transmit a system information block (SIB) of a first type in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by network energy saving (NES) communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each SSB instance in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller circuitry is configured in combination with the transceiver circuitry to increase the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increase a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and transmit, in the cell, an indication of the increased number of ROs and / or the increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

[0292] Paragraph 68. Circuity for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to receive a synchronisation signal block (SSB) from a periodic SSB burst set transmission transmitted by the infrastructure equipment in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), receive a system information block (SIB) of a first type periodically transmitted by the infrastructure equipment in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by NES communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type in the periodic SIB transmission, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each instance of the SSB in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller circuitry is configured in combination with the transceiver circuitry to receive, from the infrastructure equipment, an indication of an increased number of ROs and / or increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

[0293] Paragraph 69. Circuitry for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver to receive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), determine to transmit a Physical Random Access Channel (PRACH) and, in response, read one or more system information blocks (SIBs) of a first type received from the infrastructure equipment to determine first PRACH resources for transmitting PRACH and additional PRACH resources reserved for use by NES communications devices to transmit PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein the controller circuitry is configured in combination with the transceiver circuitry to transmit the PRACH in the first PRACH resources or the additional PRACH resources.

[0294] Paragraph 70. 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 55.

[0295] Paragraph 71. A non-transitory computer-readable storage medium storing a computer program according to paragraph 70.

[0296] 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.

[0297] Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and / or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and / or processors.

[0298] 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.

[0299] References

[0300] [1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009.

[0301] [2] TR 38.913, “Study on Scenarios and Requirements for Next Generation Access Technologies (Release 14)”, 3rd Generation Partnership Project, vl4.3.0, August 2017.

[0302] [3] TS 38.470, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NG-RAN; Fl general aspects and principles (Release 17)”, 3GPP, V17.4.0, March 2023.

[0303] [4] TS 38.473, “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NG-RAN; Fl application protocol (F1AP) (Release 17)”, 3GPP, V17.4.1, April 2023.

[0304] [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.

[0305] [6] TS38.211 “Physical channels and modulation (Rel-18),” vl8.0.0, 3GPP

[0306] [7] TS38.213, “Physical layer procedures for control (Rel-18),” vl8.0, 3GPP.

[0307] [8] RP-234065, “New WID: Enhancements of network energy savings for NR,” 3GPP TSG RAN Meeting# 102, Edinburgh, Scotland, December 11th- 15th, 2023

[0308] [9] GSMA, 5G energy efficiencies: Green is the new black, https: / / data.gsmaintelligence.com / api- web / v2 / research-file-download?id=54165956&file=241120-5G-energy.pdf

[0309]

[0010] TR 38.864, “Study on network energy savings for NR”, 3GPP, V 18. 1.0, March 2023.

Claims

CLAIMSWhat is claimed is:

1. A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the method comprising transmitting one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmitting one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and transmitting, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

2. A method according to claim 1, wherein each MIB in the one or more SSBs comprises an indication that additional PRACH resources have been reserved for use by NES communications devices to transmit PRACH, and each of the one or more SIBs of the first type comprise the indication of the additional PRACH resources reserved for use by NES communications devices to transmit PRACH.

3. A method according to claim 2, wherein the indication that the additional PRACH resources have been reserved for use by NES communications devices to transmit PRACH is indicated by a spare bit in each of MIB in the one or more SSBs.

4. A method according to claim 1, comprising transmitting an activation indication in the cell in response to one or more activation conditions being met, the activation indication indicating that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices.

5. A method according to claim 4, wherein the one or more activation conditions comprise a condition that the infrastructure equipment detects that the number of NES communications devices in the cell is above a predefined threshold.

6. A method according to claim 5, wherein the one or more activation conditions comprise a condition that the infrastructure equipment detects a collision between PRACHs at the infrastructure equipment.

7. A method according to claim 4, wherein the activation indication is transmitted in group common downlink control information (DCI).

8. A method according to claim 4, wherein the activation indication is transmitted in a paging message.

9. A method according to claim 7, wherein another activation indication indicating that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices, or a deactivation indication indicating that the activated additional PRACH resources are now deactivated for the transmission of PRACH by NES communications devices, is transmitted in a message 2 (msg2) or message B (msgB) of a PRACH procedure.

10. A method according to claim 4, wherein the activation indication is transmitted in a Physical Downlink Control Channel (PDCCH) order, a Medium Access Control (MAC) Control Element (CE), or a radio resource control (RRC) signal, or an LI signal.

11. A method according to claim 4, wherein an update of the one or more SIBs of the first type is not transmitted in response to the one or more activation conditions being met.

12. A method according to claim 1, comprising transmitting a deactivation indication in the cell in response to one or more deactivation conditions being met, the deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices.

13. A method according to claim 12, wherein the one or more deactivation conditions comprise a condition that the infrastructure equipment detects that the number of NES communications devices in the cell is below a predefined threshold.

14. A method according to claim 12, wherein the one or more deactivation conditions comprise a condition that the infrastructure equipment does not detect a collision between PRACHs at the infrastructure equipment for a predefined time period.

15. A method according to claim 12, wherein the deactivation indication is transmitted in group common downlink control information (DCI).

16. A method according to claim 12, wherein the deactivation indication is transmitted in a paging message.

17. A method according to claim 15, wherein another deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices, or an activation indicating that the deactivated additional PRACH resources are now activated for the transmission of PRACH by NES communications devices, is transmitted in a message 2 (msg2) or message B (msgB) of a PRACH procedure.

18. A method according to claim 12, wherein the deactivation indication is transmitted in a Physical Downlink Control Channel (PDCCH) order, a Medium Access Control (MAC) Control Element (CE), or a radio resource control signal, or an LI signal.

19. A method according to claim 12, wherein an indication of an update to the one or more SIBs of the first type is not transmitted in response to the one or more deactivations conditions being met.

20. A method according to claim 1, wherein the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in each of the one or more SIBs of the first type.

21. A method according to claim 20, wherein the method comprises transmitting an updated one or more SIBs of the first type, wherein each of the one or more SIBs of the first type comprise an indication of updated first PRACH resources for transmitting RACH and / or updated additional RACH resources for NES communications devices in the cell to transmit RACH.

22. A method according to claim 1, wherein the indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in an SIB of another type.

23. A method according to claim 1, wherein the indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is transmitted in a Radio Resource Control Signal (RRC), a Medium Access Control (MAC) Control Element (CE), or an LI signal.

24. A method according to claim 1, wherein each of the one or more SIBs of the first type is a system information block type 1 (SIB1).

25. A method according to claim 1, wherein the additional PRACH resources comprise a periodic configuration of RACH Occasions (ROs).

26. A method according to claim 25, wherein the first PRACH resources comprise a periodic configuration of ROs, and the period of the periodic configuration of the ROs in the additional PRACH resources is less than the period of the periodic configuration of the ROs in the first PRACH resources.

27. A method according to claim 1, wherein the first PRACH resources for transmitting PRACH are for use by NES communications devices and non-NES communications devices in the cell to transmit PRACH28. A method according to claim 1, wherein the first PRACH resources for transmitting PRACH are reserved for use by non-NES communications devices to transmit PRACH.

29. A method according to claim 1, wherein the transmission of the one or more SSBs is an adaptation of a previous periodic transmission of an SSB burst set, the adaptation comprising increasing the period between successive transmissions of the SSB burst set, wherein the indication of additional PRACH resources is transmitted in response to the adaptation.

30. A method according to claim 1, wherein the transmission of the one or more SIBs of the first type is an adaptation of a previous periodic transmission of an SIB of the first type, the adaptation comprising increasing the period between successive transmissions of the SIB of the first type, wherein the indication of additional PRACH resources is transmitted in response to the adaptation.

31. A method according to claim 1, wherein the first PRACH resources comprise a periodic configuration of RACH occasions (ROs), and the indication of additional PRACH resources is transmitted in response to an adaptation performed by the infrastructure equipment, the adaptation comprising adapting the periodic configuration of ROs in the first PRACH resources to increase the period of the periodic configuration of ROs in the first PRACH resources.

32. A method according to claim 29, wherein each MIB in the one or more SSBs comprises an indication that the adaptation of the previous transmission of the SSB burst sets has been performed by the infrastructure equipment, the adaptation of the previous transmission of the SIB of the first type has been performed by the infrastructure equipment, and / or the adaptation of the periodic configuration of ROs in the first PRACH resources has been performed by the infrastructure equipment.

33. A method according to claim 32, wherein a spare bit in each MIB in the one or more SSBs provides the indication that the adaptation of the previous transmission of the SSB burst set has been performed by the infrastructure equipment, the adaptation of the previous transmission of the SIB of the first type has been performed by the infrastructure equipment, and / or the adaptation of the periodic configuration of ROs in the first PRACH resources has been performed by the infrastructure equipment.

34. A method according to claim 29, wherein the first PRACH resources comprise a periodic configuration of RACH occasions (ROs), each RO being associated with a plurality of preambles, each of the one or more SSBs is associated with one or more of the ROs and associated with one or more of the preambles in the one or more ROs that the SSB is associated with, and the method comprises, in response to the adaptation of the previous transmission of the SSB burst set, the adaptation of the previous transmission of the SIB of the first type, and / or the adaptation of the periodic configuration of ROs in the first PRACH resources, increasing the number of ROs associated with each of the one or more SSBs, and / orincreasing the number of preambles associated with each of the one or more SSBs, and transmitting, in one or more SIBs of the first type after the increase in the number of ROs associated with each of the one or more SSBs and / or the increased in the number of preambles associated with each of the one or more SSBs, an indication of the increased number of ROs and / or the increased number of preambles associated with each of the one or more SSBs.

35. A method according to claim 1, wherein the transmission of the one or more SSBs is a periodic transmission of an SSB burst set, and an amount of the additional PRACH resources is determined based on the period between successive transmissions of the SSB, wherein the greater the period between successive transmission of the SSB burst set, the greater the amount of the additional PRACH resources.

36. A method according to claim 1, wherein the transmission of the one or more SIBs of the first type is a periodic transmission of an SIB of the first type, and an amount of the additional PRACH resources is determined based on the period between successive transmissions of the SIB of the first type, wherein the greater the period between successive transmission of the SIB of the first type, the greater the amount of the additional PRACH resources.

37. A method according to claim 1, wherein the first PRACH resources comprise a periodic configuration of RACH occasions (ROs), and an amount of the additional PRACH resources is determined based on the period of the periodic configuration of ROs in the first PRACH resources, wherein the greater the period of the periodic configuration of ROs in the first PRACH resources, the greater the amount of the additional PRACH resources.

38. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), receiving one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and receiving, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

39. A method according to claim 38, wherein the first PRACH resources for transmitting PRACH are for use by NES communications devices and non-NES communications devices in the cell to transmit PRACH40. A method according to claim 39, comprising randomly selecting between the first PRACH resources and the additional PRACH resources for transmitting a PRACH to the infrastructure equipment.

41. A method according to claim 39, comprising transmitting a PRACH to the infrastructure equipment using the first PRACH resources, determining that the infrastructure equipment did not correctly receive the PRACH, and in response, transmitting a PRACH to the infrastructure equipment in the additional PRACH resources.

42. A method according to claim 38, comprising receiving, from the infrastructure equipment, an activation indication, the activation indication indicating that the additional PRACH resources are activated for the transmission of PRACH by NES communications devices.

43. A method according to claim 38, comprisingreceiving, from the infrastructure equipment, a deactivation indication, the deactivation indication indicating that the additional PRACH resources are deactivated for the transmission of PRACH by NES communications devices44. A method according to claim 38, comprising transmitting a PRACH to the infrastructure equipment using the additional PRACH resources, determining that the additional PRACH resources have been deactivated for the transmission of PRACH because a reply to the PRACH was not received from the infrastructure equipment.

45. A method according to claim 38, comprising storing the indication of the additional PRACH resources, moving to another cell provided by other infrastructure equipment of the wireless communications network, determining an area ID of the other cell provided by the other infrastructure equipment, and based on the area ID, determining that the additional PRACH resources are also reserved for use by NES communications devices in the other cell provided by the other infrastructure equipment.

46. A method according to claim 38, wherein the indication of the additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH is received in each of the one or more SIBs of the first type.

47. A method according to claim 46, comprising determining to transmit a PRACH, and in response, reading one or more of the SIBs of the first type received from the infrastructure equipment to determine the first PRACH resources and the additional PRACH resources, and transmitting the PRACH in the first PRACH resources or the additional PRACH resources.

48. A method according to claim 46, wherein the method comprises receiving an updated one or more SIBs of the first type, wherein each of the one or more SIBs of the first type comprise an indication of updated first PRACH resources for transmitting RACH and / or updated additional RACH resources for NES communications devices in the cell to transmit PRACH, and transmitting PRACH in the updated first PRACH resources or the updated additional PRACH resources.

49. A method according to claim 48, comprising determining to transmit a PRACH, and in response, reading one or more of the updated SIBs of the first type received from the infrastructure equipment to determine the updated first PRACH resources and the updated additional PRACH resources, and transmitting the PRACH in the updated first PRACH resources or the updated additional PRACH resources.

50. A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the method comprising transmitting one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmitting one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, andanother portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

51. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving one or more synchronisation signal blocks (SSBs), each of the one or more SSBs comprising a master information block (MIB), receiving one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

52. A method of operating infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the method comprising periodically transmitting a synchronisation signal block (SSB) burst set in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), periodically transmitting a system information block (SIB) of a first type in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by network energy saving (NES) communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each SSB instance in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and the method comprises increasing the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increasing a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and transmitting, in the cell, an indication of the increased number of ROs and / or the increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

53. A method according to claim 52, wherein the increasing the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increasing a number of the preambles associated with each SSB in the periodic SSB burst set transmission is performed in response to the infrastructure equipment performing an adaptation, the adaptation comprising adapting the periodic SSB burst set transmission to increase the period between successive instances SSB burst sets in the periodic SSB burst set transmission, adapting the periodic transmission of the first type of SIB to increase the period between successive instances of the SIB of the first type in the periodic transmission of the first type of SIB, and / or adapting the periodic configuration of the PRACH resources to increase the period of the periodic configuration of the PRACH resources.

54. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprisingreceiving a synchronisation signal block (SSB) from a periodic SSB burst set transmission transmitted by the infrastructure equipment in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), receiving a system information block (SIB) of a first type periodically transmitted by the infrastructure equipment in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by NES communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type in the periodic SIB transmission, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each instance of the SSB in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and the method comprises receiving, from the infrastructure equipment, an indication of an increased number of ROs and / or increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

55. A method of operating a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the method comprising receiving one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), determining to transmit a Physical Random Access Channel (PRACH) and, in response, reading one or more system information blocks (SIBs) of a first type received from the infrastructure equipment to determine first PRACH resources for transmitting PRACH and additional PRACH resources reserved for use by NES communications devices to transmit PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and the method comprises transmitting the PRACH in the first PRACH resources or the additional PRACH resources.

56. Infrastructure equipment for a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the infrastructure equipment comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and transmit, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

57. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver toreceive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and receive, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

58. Infrastructure equipment for a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the infrastructure equipment comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

59. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to receive one or more synchronisation signal blocks (SSBs), each of the one or more SSBs comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

60. Infrastructure equipment for a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the infrastructure equipment comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to periodically transmit a synchronisation signal block (SSB) burst set in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB),periodically transmit a system information block (SIB) of a first type in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by network energy saving (NES) communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each SSB instance in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller is configured in combination with the transceiver to increase the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increase a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and transmit, in the cell, an indication of the increased number of ROs and / or the increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

61. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver to receive a synchronisation signal block (SSB) from a periodic SSB burst set transmission transmitted by the infrastructure equipment in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), receive a system information block (SIB) of a first type periodically transmitted by the infrastructure equipment in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by NES communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type in the periodic SIB transmission, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each instance of the SSB in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller is configured in combination with the transceiver to receive, from the infrastructure equipment, an indication of an increased number of ROs and / or increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

62. A network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the NES communications device comprising a transceiver configured to transmit signals and to receive signals, and a controller configured in combination with the transceiver toreceive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), determine to transmit a Physical Random Access Channel (PRACH) and, in response, read one or more system information blocks (SIBs) of a first type received from the infrastructure equipment to determine first PRACH resources for transmitting PRACH and additional PRACH resources reserved for use by NES communications devices to transmit PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein the controller is configured in combination with the transceiver to transmit the PRACH in the first PRACH resources or the additional PRACH resources.

63. Circuitry for Infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and transmit, in the cell, an indication of additional PRACH resources reserved for use by network energy saving (NES) communications devices in the cell to transmit PRACH.

64. Circuity for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to receive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of first Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, and receive, from the infrastructure equipment, an indication of additional PRACH resources reserved for use by NES communications devices in the cell to transmit PRACH.

65. Circuitry for Infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to transmit one or more synchronisation signal blocks (SSBs) in the cell, each of the one or more SSBs comprising a master information block (MIB), transmit one or more system information blocks (SIBs) of a first type in the cell, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, andanother portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

66. Circuity for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to receive one or more synchronisation signal blocks (SSBs), each of the one or more SSBs comprising a master information block (MIB), receive one or more system information blocks (SIBs) of a first type, each of the one or more SIBs of the first type comprising an indication of Physical Random Access Channel (PRACH) resources for transmitting PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein a portion of the PRACH resources are reserved for NES communications devices to transmit PRACH, and another portion of the PRACH resources are reserved for non-NES communications devices to transmit PRACH.

67. Circuitry for Infrastructure equipment of a wireless communications network providing a cell for communicating with one or more communications devices in the cell, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver circuitry to periodically transmit a synchronisation signal block (SSB) burst set in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), periodically transmit a system information block (SIB) of a first type in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by network energy saving (NES) communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each SSB instance in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller circuitry is configured in combination with the transceiver circuitry to increase the number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and / or increase a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, and transmit, in the cell, an indication of the increased number of ROs and / or the increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

68. Circuity for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, andcontroller circuitry configured in combination with the transceiver circuitry to receive a synchronisation signal block (SSB) from a periodic SSB burst set transmission transmitted by the infrastructure equipment in the cell, each SSB instance in the periodic SSB burst set transmission comprising a master information block (MIB), receive a system information block (SIB) of a first type periodically transmitted by the infrastructure equipment in the cell, each instance of the SIB of the first type in the periodic transmission of the first type of SIB comprising an indication of a periodic configuration of Physical Random Access Channel (PRACH) resources, the PRACH resources being for use by NES communications devices and / or non-NES communications devices in the cell to transmit PRACH, each MIB comprising information required to decode each instance of the SIB of the first type in the periodic SIB transmission, the periodic configuration of PRACH Resources comprising a periodic configuration of RACH Occasions (RO), each RO being associated with a plurality of preambles, each instance of the SSB in the periodic SSB burst set transmission being associated with one or more of the ROs and associated with one or more of the preambles, wherein each instance of the SIB of the first type comprises an indication of a number of the ROs associated with each SSB instance in the periodic SSB burst set transmission and a number of the preambles associated with each SSB instance in the periodic SSB burst set transmission, wherein the controller circuitry is configured in combination with the transceiver circuitry to receive, from the infrastructure equipment, an indication of an increased number of ROs and / or increased number of preambles associated with each SSB instance in the periodic SSB burst set transmission.

69. Circuitry for a network energy saving (NES) communications device for communicating with infrastructure equipment of a wireless communications network when the NES communications device is in a cell provided by the infrastructure equipment, the circuitry comprising transceiver circuitry configured to transmit signals and to receive signals, and controller circuitry configured in combination with the transceiver to receive one or more synchronisation signal blocks (SSBs), each SSB comprising a master information block (MIB), determine to transmit a Physical Random Access Channel (PRACH) and, in response, read one or more system information blocks (SIBs) of a first type received from the infrastructure equipment to determine first PRACH resources for transmitting PRACH and additional PRACH resources reserved for use by NES communications devices to transmit PRACH, each MIB in the one or more SSBs comprising information required to decode the one or more SIBs of the first type, wherein the controller circuitry is configured in combination with the transceiver circuitry to transmit the PRACH in the first PRACH resources or the additional PRACH resources.

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

71. A non-transitory computer-readable storage medium storing a computer program according to claim 70.

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