Methods, communications devices, and infrastructure equipment

Abstract

A method of operating infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES cell is provided. The method comprises transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs. Each SSB comprises a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB). The SIB comprises information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell. The one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell. The method comprises transmitting, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell. The second cell barring indication overrides the first cell barring indication for the NES communications devices.

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 EP patent application number 24158118.0, filed on 16 February 2024, the contents of which are hereby incorporated by reference in their entirety.

[0005] Description of Related Art

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

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

[0008] Current and future wireless communications networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic profiles and types than existing systems are optimised to support. For example, it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets, extended Reality (XR) and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of device, for example supporting high-definition video streaming, may be associated with transmissions of relatively large amounts of data with relatively low latency tolerance. Other types of device, for example used for autonomous vehicle communications and for other critical applications, may be characterised by data that should be transmitted through the network with low latency and high reliability. A single device type might also be associated with different traffic profiles / 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 an example of an on-demand SSB;

[0024] Figure 9 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;

[0025] Figure 10 schematically illustrates an example of a master information block (MIB) in accordance with example embodiments;

[0026] Figure 11 schematically illustrates an example of a master information block (MIB) in accordance with example embodiments;

[0027] Figure 12 schematically illustrates an example of a master information block (MIB) in accordance with example embodiments;

[0028] Figure 13 schematically illustrates an example of an Abstract Syntax Notation One (ASN1) message carried in a Broadcast Channel (BCH) in accordance with example embodiments;

[0029] Figure 14 schematically illustrates an example of an Abstract Syntax Notation One (ASN1) message carried in a Broadcast Channel (BCH) in accordance with example embodiments;

[0030] Figure 15 schematically illustrates cell-defining SSBs and non-cell defining SSBs in accordance with example embodiments;

[0031] Figure 16 is a flow diagram illustrating a method of operating infrastructure equipment of a wireless communications network in accordance with example embodiments; Figure 17 is a flow diagram illustrating a method of operating a communications device in accordance with example embodiments;

[0032] Figure 18 is a flow diagram illustrating a method of operating a communications device in accordance with example embodiments.

[0033] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Long Term Evolution Advanced Radio Access Technology (4G)

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] New Radio Access Technology (5G) 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],

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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 F 1 interface 46.

[0051] 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.

[0052] Random Access (RACH) Procedures

[0053] 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. 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. This random access preamble 51 indicates the identity of the communications device to the gNB, such that the gNB can address the communications device during later stages of the RACH procedure. 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) based on the identity indicated in the received random access preamble 51. The random access response 52 message carries a further identity which is assigned by the gNB to identify the communications device, as well as a timing advance value such that the communications device can change its 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

[0060] 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.

[0061] 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.

[0062] Synchronisation Signal Block (SSB)

[0063] 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.

[0064] 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.

[0065] An SSB burst set comprises a set of one or more time-multiplexed SSBs. Each SSB is transmitted in a burst set using a different downlink beam, thereby enabling beam sweeping to be implemented for SSB. An SSB burst set may be confined within 5 ms and may comprise up to 4, 8 and 64 SSBs for frequency bands below 3 GHz, between 3 GHz - 6 GHz and for FR2 respectively. As will be understood by one skilled in the art, SSB burst sets may be periodically transmitted.

[0066] 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).

[0067] The UE measures a signal quality of each SSB in the SSB burst set. The UE may then select one of the downlink beams based on the measured signal quality. For example, the UE may select the downlink beam with the highest measured signal quality provided that the measure signal quality is above a threshold (such as RSRP threshold). Then, the UE determines an uplink beam corresponding to the downlink beam to use for synchronisation with the infrastructure equipment. As will be appreciated by one skilled in the art, corresponding uplink and downlink beams form beam pairs which overlap. Therefore, the measurements of the signal quality of a downlink beam are an indication of the signal quality of the corresponding uplink beam in the beam pair.

[0068] 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).

[0069] 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.

[0070] 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.

[0071] 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 (an example of “legacy PRACH resources”). For example, the PRACH may be transmitted in one of a periodicity configuration of PRACH Occasions (ROs) configured for transmitting the PRACH.

[0072] Network Energy Saving (NES)

[0073] 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.

[0074] 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.

[0075] 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) [6], the energy cost of mobile networks accounts for approximately 23% of total operator cost. 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 [7],

[0076] In Release 19 of the 3GPP standards, an NES work item has been approved ([8]). The objectives of the work item are the following:

[0077] 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.

[0078] 2. Study procedures and signaling method(s) to support on-demand SIB1 for UEs in idle / inactive mode, including:

[0079] 3. Specify adaptation of common signal / channel transmissions.

[0080] NES System Information (SI)

[0081] 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 (SIB 1) and a plurality of other system information blocks (SIBs). The MIB is broadcasted in the PBCH in each SSB. The MIB comprises information required to decode SIB1. 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). Therefore, MIB and SIB1 together provide all the information which is required for initial access Accordingly, SIB 1 is defined as the “remaining minimum SI”. SIB1 may comprise scheduling information of the other SIBs (for example, mapping of SIBs to SI message, 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 SIB1 may comprise an indication of whether the other SIBs are provided on- demand, in which case, SIB 1 may also comprise an indication of a PRACH configuration for use by the UE to request the other SIBs. SIB1 may also comprise radio resource configuration information common to all communications devices in the cell in which the SIB1 is transmitted. SIB1 may also comprise cell barring information.

[0082] The other SIBs may comprise one or more of: SIB2-SIB18 and SIBpos.

[0083] — SIB2 comprises cell re-selection information, mainly related to the serving cell;

[0084] — 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);

[0085] — 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;

[0086] — 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);

[0087] — SIB6 comprises an ETWS primary notification;

[0088] — SIB7 comprises an ETWS secondary notification;

[0089] — SIB8 comprises a CMAS warning notification; — SIB9 comprises information related to GPS time and Coordinated Universal Time (UTC);

[0090] — SIB 10 comprises the Human-Readable Network Names (HRNN) of the NPNs listed in SIB1;

[0091] — SIB11 comprises information related to idle / inactive measurements;

[0092] — SIB 15 comprises information related to disaster roaming;

[0093] — SIB 16 comprises slice-based cell reselection information;

[0094] — SIB 17 comprises information related to TRS configuration for UEs in

[0095] RRC IDLE / RRC INACTIVE;

[0096] — SIBpos comprises positioning assistance data as defined in TS 37.355 and TS 38.331;

[0097] — SIB 18 comprises information related to the Group IDs for Network selection (GINs) associated with SNPNs listed in SIB1.

[0098] 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.

[0099] In the NES study phase of Release- 18 of the 3GPP standards, it has been suggested to introduce an on- demand SIB 1. 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 SIB1 in response to a request (or trigger such as a wake-up signal) from a UE. Since the SIB1 would 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 SIB 1 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.

[0100] Furthermore, as will be discussed in more detail below, it has been suggested to introduce an on-demand SSB to improve network energy savings.

[0101] On-demand SSB

[0102] 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.

[0103] An example of on-demand SSB transmission will be described with reference to Figure 8. As shown in Figure 8, 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 8. In another example (not shown), the gNB 72 may broadcast one SSB 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.

[0104] 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.

[0105] It has also been suggested, instead of on-demand SSB, to increase the period between successive legacy SSB transmissions (i.e an SSB transmitted by a legacy gNB) so that SSBs are transmitted less often, thereby reducing network energy consumption.

[0106] Although on-demand SSB, or SSBs an increased period between successive transmissions, are likely to reduce network energy consumption, technical problems arising in ensuring that existing legacy UEs are not negatively impacted. For example, legacy UEs expect SSB to be configured with a certain legacy periodicity and, if this periodicity changes, or SSB is configured to be on-demand, this may cause legacy UEs to experience decoding and / or detection failures and therefore waste energy and communications resources.

[0107] For initial access, legacy UEs will try to access aNES cell starting from detecting SSBs. However, since the NES cell does not provide enough signalling and / or control information to the legacy UE in order to save energy, the legacy UE may fail to access the cell, which will result in increasing access latency and power consumption for the UE. In one example, if the legacy UE attempts to access an NES cell which provides on-demand SIB1, access failure happens after MIB decoding because the legacy UE is not able to request and then receive SIB1. This increases access latency because the legacy UE does not know that it is unable to access the NES cell until after it has already decoded the MIB.

[0108] There is therefore a need for improved methods, communications devices and infrastructure equipment which can provide network energy savings without significantly impacting the performance of legacy communications devices.

[0109] NES SSB and MIB design

[0110] Figure 9 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 and infrastructure equipment 64 (e.g. an NES gNB) of a wireless communications network. The non-NES communication device 66 is a communications device which does not support NES functions. For example, the communications device 66 may be a legacy communications device which does not support NES functions.

[0111] 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 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, 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. The infrastructure equipment 64 provides a network energy saving (NES) cell for one or more communications devices in the NES cell. The infrastructure equipment 64 may therefore be referred to as “NES” infrastructure equipment, but this reference will be omitted for brevity since it is already implicit from the fact that the infrastructure equipment 64 provides an NES cell that it is NES infrastructure equipment. In the example of Figure 9, the NES communications device 62 and the non-NES communications device 66 are in the NES cell.

[0112] As shown in Figure 9, the controller 64.2 of the infrastructure equipment 64 controls the transceiver 64. 1 of the infrastructure equipment to transmit 68, to the NES communications device 62 and the non-NES communications device 66, one or more synchronisation signal blocks, SSBs. Each SSB comprises a master information block (MIB). Each MIB comprises information required by the communications devices 62, 66 to decode a system information block (SIB).

[0113] The SIB comprises information required by communications devices 62, 66 to perform an initial access procedure with the infrastructure equipment 64 to access the NES cell. In existing systems, the SIB which provides information required for initial access is referred to as “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 information required for initial access. Therefore, although example embodiments will refer specifically to SIB 1, it should be understood that the present disclosure is not so limited and any SIB containing information required for initial access may be used.

[0114] In some embodiments, the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the communications devices in the NES cell (in this example, the first cell barring indication indicates that access to the NES cell is barred for the NES communications device 62 and the non-NES communications device 66). In such embodiments, the controller 64.2 of the infrastructure equipment 64 may control the transceiver 64. 1 of the infrastructure equipment 64 to transmit a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell (in this example, the second cell barring indication indicates whether or not NES communications device 62 is barred from accessing the NES cell).

[0115] The second cell barring indication overrides the first cell barring indication for NES communications devices in the NES cell (in this example, the second cell barring indication overrides the first cell barring indication for NES communications device 62). Therefore, NES communications device 62 ignores the first cell barring indication, while the non-NES communications device 66 determines that it is barred from accessing the NES cell based on the first cell barring indication. The second cell barring indication therefore indicates to the NES communications device 62 whether it is in fact barred from accessing the NES cell.

[0116] The second cell barring indication may be transmitted as part of signal 68. For example, the second cell barring indication may be indicated by a spare bit in each MIB. Alternatively, the second cell barring indication may be transmitted in a separate signal. For example, the spare bit in MIB may indicate that an extra message is to be transmitted by the infrastructure equipment, and the second message comprises the second cell barring indication.

[0117] In some embodiments, the SIB comprises the second cell barring indication. For example, a cellBarredNES information element in SIB1 may be used to provide the second cell barring indication. By using a first barring indication and a second barring indication, non-NES communications devices can be barred from accessing NES cells while NES communications devices may be allowed to access NES cells. Since the first cell barring indication is transmitted in the MIB, the non-NES communications devices will not proceed to attempt to read SIB 1. Therefore, latency in non-NES communications devices determining that they cannot access an NES cell is reduced. Furthermore, since the first cell barring indication is transmitted in MIB which non-NES communications devices can receive, specifications changes to incorporate the functioning of the second cell barring indication do not significantly impacted (if at all) the non-NES communications devices.

[0118] In some embodiments, instead of using the first and second cell barring indications, the one or more SSBs are configured to prevent non-NES communications devices in the NES cell (in this example, non-NES communications device 66) from either receiving or decoding the SSBs and to allow NES communications devices in the NES cell (in this example NES communications device 62) to receive and decode the SSBs (and hence the MIBs in the SSBs). In some such embodiments, a frequency position of the SSBs may be a frequency position known and monitored only by NES communications devices and not known nor monitored by non-NES communications devices, therefore preventing non-NES communications devices from receiving the SSBs. In some such embodiments, a scrambling code may be applied to a Physical Broadcast Channel (PBCH) that carries the MIB in the SSBs where the scrambling code is known to NES communications devices and the scrambling code is not known to non-NES communications devices. Therefore, non-NES communications devices are prevented from decoding the SSBs and the PBCH. In some embodiments, a choice bit in a Broadcast Control Channel (BCCH)- Broadcast Channel (BCH)-message indicates to select a messageClassExtension field where in Release 18 and previous releases, the choice field indicates to select the MIB. If the choice bit is set to select messageClassExtension instead, Non-NES communications devices will fail to decode MIB.

[0119] By preventing non-NES communications devices in the NES cell from either receiving or decoding the SSBs, non-NES communications devices will cease to attempt to access the NES cell before the SSBs are decoded and will not proceed to attempt to read SIB 1. Therefore, latency in non-NES communications devices determining that they cannot access an NES cell is reduced.

[0120] Accordingly, example embodiments can provide network energy savings without significantly impacting the performance of non-NES communications devices.

[0121] For ease of explanation, embodiments will be described below 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”.

[0122] 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. gNBs which provide one or more NES cells may be referred to as “NES gNBs”.

[0123] NES functions may comprise one or more of the following:

[0124] (1). Supporting SSB with intervals between broadcasts of more than 20 ms on an initial bandwidth part. In other words, an NES cell is a cell which supports transmission of SSBs with intervals between broadcasts of more than 20 ms on an initial bandwidth part. An NES UE is able to receive SSBs with intervals between broadcasts of more than 20 ms on an initial bandwidth part. By contrast, a legacy gNB providing a legacy cell would transmit SSB with intervals between broadcasts of 20 ms or less on the initial bandwidth part. Therefore, legacy UEs in the legacy cell can assume that SSBs will be transmitted in the legacy cell with intervals between broadcasts of 20 ms or less on the initial bandwidth part.

[0125] (2). Supporting on-demand SSB. In other words, an NES cell supports on-demand SSB transmission. An NES UE is configured to request and receive on-demand SSBs. By contrast, a legacy UE assumes SSB is always-on and periodically transmitted. A legacy gNB providing a legacy cell does not support on demand SSB transmission.

[0126] (3). Supporting on-demand SIB 1. In other words, an NES cell supports on-demand SIB 1 transmission. An NES UE is configured to request and receive on-demand SIB1. By contrast, a legacy UE assumes SIB1 is periodically transmitted. A legacy gNB providing a legacy cell does not support on demand SIB transmission.

[0127] In some embodiments, an NES UE and NES cell are defined as UEs and cells which support: 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).

[0128] Non-NES UEs and non-NES cells are UEs and cells which do not support the NES functions supported by the NES UEs and NES cells.

[0129] Indication to non-NES UEs not to access NES Cell

[0130] In accordance with example embodiments, a first cell barring indication may be transmitted by a gNB providing an NES cell. Non-NES UEs (i.e., non-NES communication devices) receiving the first cell barring indication will determine that they are barred from accessing the NES cell and will therefore cease their attempt to access the NES cell and instead attempt to access another cell.

[0131] In accordance with example embodiments, the first cell barring indication is a cellBarred field in the MIB indicating that access to the NES cell is barred. An example of an MIB is shown in Figure 10. The MIB shown in Figure 10 comprises 23 bits. As shown in Figure 10, the MIB comprises a cellBarred field 92. In accordance with example embodiments, the cellBarred field 92 is configured to provide the first cell barred indication indicating that UEs are barred from accessing the NES cell. The cellBarred field 92 may therefore always be set to “barred” for NES cells. Consequently, legacy UEs receiving this indication in the MIB will not proceed to the next stage of accessing the NES cell (i.e. reading SIB1) and so will not camp on this cell. By contrast, NES UEs may be configured to ignore the cellBarred field 92 of the MIB. Therefore, NES UEs will not determine that they are barred from accessing the NES cell based on the first cell barred indication in the cellBarred field 92.

[0132] In accordance with example embodiments, the gNB providing the NES cell may transmit a second cell barring indication indicating whether or not NES communications devices are barred from the NES cell.

[0133] In some embodiments, the second cell barring indication is indicated by converting the spare bit in the MIB to a cell barring indicator for NES UEs. An example of this is shown in Figure 11. As shown in Figure 11, the spare bit of the MIB has been configured to indicate the second cell barring indication. In this example, the bit is converted into cellBarredforNESUE 94 and provides the second cell barring indication by indicating whether or not NES UEs receiving the MIB are barred from accessing the NES cell. The non-NES UE ignores the second cell barring indication as it is regarded as the spare bit, while the NES UE recognizes the second cell barring indication and determines whether or not the NES UES are barred from accessing the NES cell. In some embodiments, the MIB comprises an indication of an extra message and the extra message comprises the second cell barring indication. An example of this is shown in Figure 12. As shown in Figure 12, the spare bit in MIB may be reconfigured to provide an indication of whether or not an extra message is provided. The ExtraMessage field 96 of the MIB illustrated in Figure 12 provides the indication of whether or not the extra message is provided. The extra message may comprise the second cell barring indication. The radio resource location of the extra message may be predefined in specifications and may be specified, for example, relative to a position of an SSB.

[0134] In some embodiments, SIB1 may comprise the second cell baring indication. SIB1 already contains a “cellBarredNES” field. However, this field is only applicable to UEs capable of NES cell DTX / DRX. In accordance with example embodiments, this field is configured to be applicable to all NES UEs. In other words, this field is configured to provide an indication of whether or not any NES UE receiving the MIB (i.e. not just UEs capable of NES cell DTX / DRX) are barred from accessing the NES cell.

[0135] In some embodiments, the second cell barring indication is indicated by a choice bit in a broadcast channel (BCH).

[0136] Preventing non-NES UEs from receiving SSB or preventing non-NES UEs from decoding SSB

[0137] SSB Raster

[0138] In some embodiments, the one or more SSBs transmitted by a gNB providing an NES cell may be configured so that NES UEs in the NES cell can receive and decode the SSBs and non-NES UEs in the NES cell cannot receive or cannot decode the SSBs. By preventing non-NES UEs from receiving or decoding the SSBs, non-NES UEs can determine at an early stage of attempting to access the NES cell that the UE cannot access the NES cell. Therefore, latency between the UE attempting to access the cell and the UE ceasing its attempt to access the cell is decreased.

[0139] In some embodiments, a frequency position of the SSBs is a frequency position that is monitored by NES UEs but that is not monitored by non-NES UEs. Table 1 below defines the raster (frequency position) of SSB transmitted by non-NES gNB. A non-NES UE searches for SSBs only on the frequency positions indicated in Table 1.

[0140] Table 1. Raster of SSB transmitted by non-NES gNB

[0141] In accordance with example embodiments, SSBs transmitted by a gNB providing an NES cell are located in different frequency positions than the positions shown in the SSB raster shown in Table 1.

[0142] Table 2 below defines an NES SSB raster in accordance with example embodiments.

[0143] Table 2. Example of Raster of SSB transmitted by NES gNB

[0144] As shown in Table 2, a frequency offset (e.g. 600 kHz) has been added to the centre frequency of SSBs in the frequency range 0 - 3000 MHz compared with the raster of SSB transmitted by non-NES gNB and another frequency offset (0.72 MHz) has been added to the centre frequency of SSBs in the frequency range 3000-24250 MHz compared with the raster of SSB transmitted by non-NES gNB.

[0145] NES UEs may be configured to search on the frequency positions of the SSBs in Table 2 and / or the Ifrequency positions of the SSBs in Table 1, whereas non-NES UEs will continue to monitor the frequency positions indicated in Table 1 only. Therefore, non-NES UEs will not receive SSBs transmitted on the frequency positions indicated in Table 2.

[0146] Scrambling / coding of PBCH

[0147] In accordance with example embodiments, a scramble code is applied to the contents of a Physical Broadcast Channel (PBCH) such as the MIB in SSBs transmitted by a gNB providing an NES cell. NES UEs may be configured to know the scramble code. Therefore, NES UEs can successfully decode the PBCH. However, PBCH in non-NES SSBs does not have a scramble code applied. Therefore, non-NES UEs will attempt to decode the PBCH assuming that no scramble code has been applied. However, since the PBCH from an NES cell does in fact have a scramble code applied, non-NES UEs will be unable to decode the PBCH. Therefore, non-NES UEs will fail to access the NES cell at the MIB acquisition stage.

[0148] Choice Bit of MIB

[0149] Figure 13 schematically illustrates an example of an Abstract Syntax Notation One (ASN1) message carried in a Broadcast Channel (BCH). As shown in Figure 13, the ASN1 message comprises a choice bit 102 which can be configured to indicate a UE to select either “mib ” or “messageClassExtension

[0150] In non-NES cells, the choice bit 102 is always configured to indicate to UEs to select mib. After reading this indication, non-NES UEs proceed to acquire MIB. However, if the choice bit 102 is instead configured to indicate to UEs to select messageClassExtension, non-NES UEs are not able to acquire MIB.

[0151] In accordance with example embodiments, the choice bit 102 in the MIB is configured to indicate UEs to select messageClassExtension. The messageClassExtension field is configured to indicates to UEs to acquire an NES MIB (i.e. an MIB transmitted in an NES cell). An example of this is shown in Figure 14. As shown in Figure 14, the messageClassExtension field 104 is configured to indicate to acquire an NES MIB. In the NES MIB, the following fields may be additionally contained in addition to or replacing fields defined in legacy MIB:

[0152] • SSB periodicity,

[0153] • UL resource to trigger on-demand SIB 1

[0154] The NES MIB bit size may be less than the MIB shown in Figure 10 (i.e an MIB transmitted in a non- NES cell) bit size which is 23 bits. Non-Cell Defining SSB

[0155] Non-cell defining SSBs have been defined as SSBs that are not associated with SIB1 providing to non- NES UE (i.e. a periodic SIB1 transmitted by a non-NES gNB). Specifically, MIB in non-cell defining SSBs does not indicate a CORESET for TypeO-PDCCH CSS set. Non-NES UEs assume that an SSB is a non-cell defining SSB if a CORESET subcarrier offset from SSB (kssB) is greater than 23 for FR1 or kssB is greater than 11 for FR2. kssB is determined by 1 bit of PBCH payload and field ssb-SubcarrierOffset in the MIB. The non-NES UE will attempt to search other SSBs if the SSB is determined to be a non-cell defining SSB because non-cell defining SSBs are not associated with CORESET#0 and SIB1. Celldefining SSBs are defined as SSBs which are associated with SIB1. Cell-defining SSBs may comprise CORESET for TypeO-PDCCH CSS set. Non-cell defining SSBs are typically used for the purposes of time / frequency synchronisation and RRM measurements only.

[0156] An example of cell-defining SSBs and non-cell defining SSBs are shown in Figure 15. As shown in Figure 15, the periodicity of cell-defining SSBs is typically equal to or less than 20 ms because non-NES UEs assume an SSB periodicity of 20 ms for cell selection. However, since non-cell defining SSBs only used by non-NES UEs for the purposes of time / frequency synchronisation and RRM measurement (and they are not used for the purpose of initial access), the period of non-cell defining SSBs can be longer than that of cell-defining SSBs. For example, the non-cell defining SSBs in Figure 15 have a period of 160 ms between successive transmissions of the SSB.

[0157] In accordance with example embodiments, NES UEs may use one or more of the non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment. This contributes to network energy savings because non-cell defining SSBs are transmitted less often than cell-defining SSBs. For example, a NES cell transmits only non-cell defining SSB with a period of greater than 20 ms between successive transmissions and does not transmit cell defining SSBs for non-NES UE.

[0158] The MIB in the non-cell defining SSB carries indication of non-cell defining SSB for non-NES UE by using parameter kssB. Additionally, the MIB in the non-cell defining SSB carries information for NES UE. For example, the MIB in the non-cell defining SSB carries a CORESET for TypeO-PDCCH CSS set for NES UE. For another example, the MIB in the non-cell defining SSB carries an indication of whether it is cell defining SSB or non-cell defining SSB for NES UE. Since kssB > 23 for FR1 and kssB > 11 for FR2 have indication that the detected SSB is non-cell defining SSB for non-NES, the indication of whether it is cell defining SSB or non-cell defining SSB for NES UE can be indicated by some reinterpreted fields in MIB (unused parameter for non-NES UE, e.g. spare bit) to NES UE or extra message other than the MIB or SIB.

[0159] Methods of operating communications devices and infrastructure equipment in accordance with example embodiments

[0160] Figure 16 is a flow diagram method of operating infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for one or more communications devices in accordance with example embodiments. The method starts in step SI.

[0161] In step S2, the method comprises transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs. Each SSB comprises a master information block (MIB). Each MIB comprises information required by the one or more communications devices to decode a system information block (SIB). The SIB comprises information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell. The one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell.

[0162] In step S3, the method comprises transmitting, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell. The second cell barring indication overrides the first cell barring indication for NES communications devices.

[0163] The method ends in step S4.

[0164] Figure 17 is a flow diagram illustrating a method of operating a network energy saving (NES) communications device in accordance with example embodiments. The method starts in step Si l.

[0165] In step S 12, the method comprises receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs. Each SSB comprises a master information block (MIB). Each MIB comprises information required by the NES communications device to decode a system information block (SIB). The SIB comprises information required by the NES communications device to perform an initial access procedure with the infrastructure equipment.

[0166] The one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred.

[0167] In step SI 3, the method comprises ignoring the first cell barring indication.

[0168] In step S 14, the method comprises receiving, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

[0169] The method ends in step S15.

[0170] Figure 18 is a flow diagram illustrating a method of operating a network energy saving (NES) communications device in accordance with example embodiments. The method starts in step S21.

[0171] In step S21, the method comprises receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs. Each SSB comprises a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB). The SIB comprises information required by the NES communications device to perform an initial access procedure with the infrastructure equipment. The one or more of SSBs comprise one or more non-cell defining SSBs. The non-cell defining SSBs are SSBs not associated with the SIB.

[0172] In step S22, the method comprises using the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

[0173] The method ends in step S23. As will be appreciated by a person skilled in the art, the relative order of the steps in Figure 16, Figure 17 and Figure 18 may be interchanged in any logical order. For example, the order of steps S13 and S15 in Figure 17 may be switched.

[0174] In accordance with example embodiments, there is provided a method of infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES cell. The method comprises transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs Each SSB comprises a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB). The SIB comprises information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell. In accordance with example embodiments, the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

[0175] In accordance with example embodiments, there is provided a method of operating a network energy saving (NES) communications device. The method comprises receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs. Rach SSB comprises a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB). The SIB comprises information required by the NES communications device to perform an initial access procedure with the infrastructure equipment. In accordance with example embodiments, the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

[0176] 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.

[0177] The following numbered paragraphs provide further example aspects and features of the present technique:

[0178] Paragraph 1. A method of operating infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES cell, the method comprising transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell, and the method comprises transmitting, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell, the second cell barring indication overriding the first cell barring indication for the NES communications devices. Paragraph 2. A method according to paragraph 1, wherein the first cell barring indication in the MIB is a cellBarred field in the MIB indicating that access to the NES cell is barred.

[0179] Paragraph 3. A method according to paragraph 1 or paragraph 2, wherein the second cell barring indication is also comprised in the MIB.

[0180] Paragraph 4. A method according to paragraph 3, wherein the second cell barring indication is indicated by a spare bit of the MIB.

[0181] Paragraph 5. A method according to paragraph 1 or paragraph 2, wherein the MIB in the one or more SSBs comprises an indication that an extra message will be transmitted by the infrastructure equipment to the one or more communications devices in the NES cell, wherein the extra message comprises the second cell barring indication.

[0182] Paragraph 6. A method according to paragraph 1 or paragraph 2, wherein the method comprises transmitting the SIB to the one or more communications devices in the NES cell, wherein the SIB comprises the second cell barring indication.

[0183] Paragraph 7. A method according to paragraph 1 or paragraph 2, wherein the second cell barring indication is indicated by a choice bit in a broadcast channel (BCH).

[0184] Paragraph 8. A method according to any of paragraphs 1 to 7, wherein the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell is a system information block type 1 (SIB 1).

[0185] Paragraph 9. A method according to any of paragraphs 1 to 8, wherein

[0186] NES communications devices are communications devices that are able to receive SSBs with a period between successive SSB transmissions of more than 20 ms on an initial bandwidth part,

[0187] NES cells are cells in which SSBs with a period of more than 20 ms on an initial bandwidth part can be transmitted,

[0188] Non-NES communications devices are communications devices that are not able to receive SSBs with a period between successive SSB transmissions of more than 20 ms on an initial bandwidth part, and Non-NES cells are cells in which SSBs with a period of more than 20 ms on an initial bandwidth part cannot be transmitted.

[0189] Paragraph 10. A method according to paragraph 9, wherein

[0190] NES communications devices are also able to receive SSBs with a period between successive SSB transmissions of less than or equal to 20 ms on an initial bandwidth part, and

[0191] NES cells also support SSBs with a period of less than or equal to 20ms on an initial bandwidth part.

[0192] Paragraph 11. A method according to any of paragraphs 1 to 10, wherein

[0193] NES communications devices are communications devices that are configured to request and receive on-demand SSBs,

[0194] NES cells are cells in which on-demand SSB is supported,

[0195] Non-NES communications devices are communications devices that are not configured to request and receive on-demand SSB, and

[0196] Non-NES cells are cells in which on-demand SSB is not supported.

[0197] Paragraph 12. A method according to any of paragraphs 1 to 11, wherein

[0198] NES communications devices are communications devices that are configured to request and receive an on-demand SIB comprising information required for performing initial access,

[0199] NES cells are cells in which an on-demand SIB comprising information required for performing initial access is supported,

[0200] Non-NES communications devices are communications devices that are not configured to request and receive an on-demand SIB comprising information required for performing initial access, and

[0201] Non-NES cells are cells in which an on-demand SIB comprising information required for performing initial access is not supported.

[0202] Paragraph 13. A method according to paragraph 12, wherein the on-demand SIB comprising information required for performing initial access is a system information block type 1 (SIB1). Paragraph 14. A method of operating infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES cell, the method comprising transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

[0203] Paragraph 15. A method according to paragraph 14, wherein a frequency position of the SSBs is a frequency position that is monitored by NES communications devices but that is not monitored by non- NES communications devices.

[0204] Paragraph 16. A method according to any of paragraphs 14 to 15, wherein a scramble code is applied to a Physical Broadcast Channel (PBCH) in the SSBs, wherein the scramble code is known to NES communications devices and the scramble code is not known to non-NES communications devices.

[0205] Paragraph 17. A method according to any of paragraphs 14 to 16, wherein a choice bit in a Broadcast Control Channel (BCCH)-Broadcast Channel (BCH) message of the SSBs indicates to the one or more communications devices to select a messcigeClassExtension field, wherein the messageClassExtension field indicates to acquire the MIB in the SSBs, the MIB in the SSBs being an NES MIB.

[0206] Paragraph 18. A method according to paragraph 17, wherein the MIB in the one or more SSBs comprises an indication of periodicity with which the one or more SSBs are transmitted or an indication of uplink resources for use by NES communications devices to transmit a trigger signal to the infrastructure equipment to trigger transmission of the SIB.

[0207] Paragraph 19. A method according to any of paragraphs 14 to 18, wherein the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell is a system information block type 1 (SIB1). Paragraph 20. A method of operating a network energy saving (NES) communications device, the method comprising receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred, and the method comprises ignoring the first cell barring indication, and receiving, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

[0208] Paragraph 21. A method of operating a network energy saving (NES) communications device, the method comprising receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

[0209] Paragraph 22. A method of operating a network energy saving (NES) communications device, the method comprising receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more of SSBs comprise one or more non-cell defining SSBs, the non-cell defining SSBs are SSBs not associated with the SIB, and the method comprises using the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

[0210] Paragraph 23. A method according to paragraph 22, wherein the MIB in the one or more non-cell defining SSBs does not indicate a Control Resource Set (CORESET) for a TypeO-Physical Downlink Control Channel (PDCCH) Common Search Space (CSS) set.

[0211] Paragraph 24. A method according to paragraph 22 or paragraph 23, wherein the one or more non-cell defining SSBs comprise a plurality of periodic non-cell defining SSBs, wherein a period between successive transmissions of the non-cell defining SSBs is greater than 20 ms.

[0212] Paragraph 25. Infrastructure equipment for a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell, and the controller is configured in combination with the transceiver to transmit, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell, the second cell barring indication overriding the first cell barring indication for the NES communications devices.

[0213] Paragraph 26. Infrastructure equipment for a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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 to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

[0214] Paragraph 27. A network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred, and the controller is configured in combination with the transceiver to ignore the first cell barring indication, and receive, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

[0215] Paragraph 28. A network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

[0216] Paragraph 29. A network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more of SSBs comprise one or more non-cell defining SSBs, the non-cell defining SSBs are SSBs not associated with the SIB, and the controller is configured in combination with the transceiver to use the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

[0217] Paragraph 30. Circuitry for infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell, and the controller circuitry is configured in combination with the transceiver circuitry to transmit, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell, the second cell barring indication overriding the first cell barring indication for the NES communications devices.

[0218] Paragraph 31. Circuitry for infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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 to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

[0219] Paragraph 32. Circuitry for a network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred, and the controller circuitry is configured in combination with the transceiver circuitry to ignore the first cell barring indication, and receive, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

[0220] Paragraph 33. Circuitry for a network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

[0221] Paragraph 34. Circuitry for a network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more of SSBs comprise one or more non-cell defining SSBs, the non-cell defining SSBs are SSBs not associated with the SIB, and the controller circuitry is configured in combination with the transceiver circuitry to use the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

[0222] Paragraph 35. 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 24.

[0223] Paragraph 36. A non-transitory computer-readable storage medium storing a computer program according to paragraph 35.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] References

[0228] [1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009.

[0229] [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.

[0230] [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.

[0231] [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.

[0232] [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.

[0233] [6] RP-234065, “New WID: Enhancements of network energy savings for NR,” 3GPP TSG RAN Meeting# 102, Edinburgh, Scotland, December 11th- 15th, 2023

[0234] [7] 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

[0235] [8] 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 network energy saving (NES) cell for communicating with one or more communications devices in the NES cell, the method comprising transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell, and the method comprises transmitting, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell, the second cell barring indication overriding the first cell barring indication for the NES communications devices.

2. A method according to claim 1, wherein the first cell barring indication in the MIB is a cellBarred field in the MIB indicating that access to the NES cell is barred.

3. A method according to claim 1, wherein the second cell barring indication is also comprised in the MIB.

4. A method according to claim 3, wherein the second cell barring indication is indicated by a spare bit of the MIB.

5. A method according to claim 1, wherein the MIB in the one or more SSBs comprises an indication that an extra message will be transmitted by the infrastructure equipment to the one or more communications devices in the NES cell, wherein the extra message comprises the second cell barring indication.

6. A method according to claim 1, wherein the method comprises transmitting the SIB to the one or more communications devices in the NES cell, wherein the SIB comprises the second cell barring indication.

7. A method according to claim 1, wherein the second cell barring indication is indicated by a choice bit in a broadcast channel (BCH).

8. A method according to claim 1, wherein the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell is a system information block type 1 (SIB1).

9. A method according to claim 1, whereinNES communications devices are communications devices that are able to receive SSBs with a period between successive SSB transmissions of more than 20 ms on an initial bandwidth part,NES cells are cells in which SSBs with a period of more than 20 ms on an initial bandwidth part can be transmitted,Non-NES communications devices are communications devices that are not able to receive SSBs with a period between successive SSB transmissions of more than 20 ms on an initial bandwidth part, andNon-NES cells are cells in which SSBs with a period of more than 20 ms on an initial bandwidth part cannot be transmitted.

10. A method according to claim 9, whereinNES communications devices are also able to receive SSBs with a period between successive SSB transmissions of less than or equal to 20 ms on an initial bandwidth part, andNES cells also support SSBs with a period of less than or equal to 20ms on an initial bandwidth part.

11. A method according to claim 1, whereinNES communications devices are communications devices that are configured to request and receive on-demand SSBs,NES cells are cells in which on-demand SSB is supported,Non-NES communications devices are communications devices that are not configured to request and receive on-demand SSB, andNon-NES cells are cells in which on-demand SSB is not supported.

12. A method according to claim 1, whereinNES communications devices are communications devices that are configured to request and receive an on-demand SIB comprising information required for performing initial access,NES cells are cells in which an on-demand SIB comprising information required for performing initial access is supported,Non-NES communications devices are communications devices that are not configured to request and receive an on-demand SIB comprising information required for performing initial access, andNon-NES cells are cells in which an on-demand SIB comprising information required for performing initial access is not supported.

13. A method according to claim 12, wherein the on-demand SIB comprising information required for performing initial access is a system information block type 1 (SIB1).

14. A method of operating infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES cell, the method comprising transmitting, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

15. A method according to claim 14, wherein a frequency position of the SSBs is a frequency position that is monitored by NES communications devices but that is not monitored by non-NES communications devices.

16. A method according to claim 14, wherein a scramble code is applied to a Physical Broadcast Channel (PBCH) in the SSBs, wherein the scramble code is known to NES communications devices and the scramble code is not known to non-NES communications devices.

17. A method according to claim 14, wherein a choice bit in a Broadcast Control Channel (BCCH)- Broadcast Channel (BCH) message of the SSBs indicates to the one or more communications devices to select a messcigeClassExtension field, wherein the messageClassExtension field indicates to acquire the MIB in the SSBs, the MIB in the SSBs being an NES MIB.

18. A method according to claim 17, wherein the MIB in the one or more SSBs comprises an indication of periodicity with which the one or more SSBs are transmitted or an indication of uplink resources for use by NES communications devices to transmit a trigger signal to the infrastructure equipment to trigger transmission of the SIB.

19. A method according to claim 14, wherein the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell is a system information block type 1 (SIB1).

20. A method of operating a network energy saving (NES) communications device, the method comprising receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred, and the method comprises ignoring the first cell barring indication, and receiving, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

21. A method of operating a network energy saving (NES) communications device, the method comprising receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

22. A method of operating a network energy saving (NES) communications device, the method comprising receiving, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more of SSBs comprise one or more non-cell defining SSBs, the non-cell defining SSBs are SSBs not associated with the SIB, and the method comprises using the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

23. A method according to claim 22, wherein the MIB in the one or more non-cell defining SSBs does not indicate a Control Resource Set (CORESET) for a TypeO-Physical Downlink Control Channel (PDCCH) Common Search Space (CSS) set.

24. A method according to claim 22, wherein the one or more non-cell defining SSBs comprise a plurality of periodic non-cell defining SSBs, wherein a period between successive transmissions of the non-cell defining SSBs is greater than 20 ms.

25. Infrastructure equipment for a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell, and the controller is configured in combination with the transceiver to transmit, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell, the second cell barring indication overriding the first cell barring indication for the NES communications devices.

26. Infrastructure equipment for a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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 to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

27. A network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred, and the controller is configured in combination with the transceiver to ignore the first cell barring indication, and receive, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

28. A network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

29. A network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more of SSBs comprise one or more non-cell defining SSBs, the non-cell defining SSBs are SSBs not associated with the SIB, and the controller is configured in combination with the transceiver to use the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

30. Circuitry for infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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, to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred for the one or more communications devices in the NES cell, and the controller circuitry is configured in combination with the transceiver circuitry to transmit, to the one or more communications devices in the NES cell, a second cell barring indication indicating whether or not NES communications devices are barred from accessing the NES cell, the second cell barring indication overriding the first cell barring indication for the NES communications devices.

31. Circuitry for infrastructure equipment of a wireless communications network providing a network energy saving (NES) cell for communicating with one or more communications devices in the NES 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 to the one or more communications devices in the NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the one or more communications devices to decode a system information block (SIB), the SIB comprising information required by the one or more communications devices to perform an initial access procedure with the infrastructure equipment to access the NES cell, whereinthe one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow NES communications devices to receive and decode the SSBs.

32. Circuitry for a network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured so that the MIB in the one or more SSBs comprises a first cell barring indication indicating that access to the NES cell is barred, and the controller circuitry is configured in combination with the transceiver circuitry to ignore the first cell barring indication, and receive, from the infrastructure equipment, a second cell barring indication indicating whether or not the NES communications device is barred from accessing the NES cell.

33. Circuitry for a network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more SSBs are configured to prevent non-NES communications devices from either receiving or decoding the SSBs and to allow the NES communications device to receive and decode the SSBs.

34. Circuitry for a network energy saving (NES) communications device, 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, from infrastructure equipment of a wireless communications network providing an NES cell, one or more synchronisation signal blocks, SSBs, each SSB comprising a master information block (MIB) comprising information required by the NES communications device to decode a system information block (SIB), the SIB comprising information required by the NES communications device to perform an initial access procedure with the infrastructure equipment, wherein the one or more of SSBs comprise one or more non-cell defining SSBs, the non-cell defining SSBs are SSBs not associated with the SIB, and the controller circuitry is configured in combination with the transceiver circuitry to use the one or more non-cell defining SSBs to perform the initial access procedure with the infrastructure equipment.

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

36. A non-transitory computer-readable storage medium storing a computer program according to claim 35.

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