Method, user equipment and access network node

Abstract

A communication system is disclosed in which an access network node that transmits, to a UE, information identifying, for each block of a plurality of blocks, a respective a cell discontinuous transmission (DTX) and / or discontinuous reception (DRX) configuration, wherein each block is associated with at least one cell of a plurality of cells operated by the access network node. The access network node may also transmit, to the UE, information identifying, for each cell of the plurality of cells, the respective block associated with that cell.

Description

METHOD, USER EQUIPMENT AND ACCESS NETWORK NODE

[0001] The present disclosure relates to a communication system and to parts thereof. The disclosure has particular but not exclusive relevance to wireless communication systems and devices thereof operating according to the 3rd Generation Partnership Project (3GPP) standards or equivalents or derivatives thereof (including LTE-Advanced, Next Generation or 5G networks, future generations, and beyond). The disclosure has particular, although not necessarily exclusive, relevance to cell discontinuous reception (DRX) and cell discontinuous transmission (DTX) to reduce energy consumption within the network and the ramifications of using such network energy saving (NES) techniques.

[0002] Earlier developments of the 3GPP standards were referred to as the Long-Term Evolution (LTE) of Evolved Packet Core (EPC) network and Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), also commonly referred as '4G'. More recently, the term '5G' and 'new radio' (NR) has started to be used to refer to an evolving communication technology that is expected to support a variety of applications and services. Various details of 5G networks are described in, for example, NPL 1. 3GPP intends to support 5G by way of the so-called 3GPP Next Generation (NextGen) radio access network (RAN) and the 3GPP NextGen core network.

[0003] Under the 3GPP standards, a NodeB (or an eNB in LTE, and gNB in 5G) is the radio access network (RAN) node (or simply 'access node', 'access network node' or 'base station') via which communication devices (user equipments or 'UEs') connect to a core network and communicate with other communication devices or remote servers. For simplicity, the present application will use the term access network node, RAN node or base station to refer to any such access nodes.

[0004] For simplicity, the present application will use the term mobile device, user device, or UE to refer to any communication device that is able to connect to the core network via one or more base stations. Although the present application may refer to mobile devices in the description, it will be appreciated that the technology described can be implemented on any communication devices (mobile and / or generally stationary) that can connect to a communications network for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory.

[0005] In the current 5G architecture, the gNB structure may be split into two or more parts. In some RAN implementations there are two parts, known as the Central Unit (CU or gNB-CU) - sometimes referred to as a 'control unit' - and the Distributed Unit (DU or gNB-DU), connected by an F1 interface. This enables the use of a 'split' architecture in which the typically 'higher' CU layers (for example, but not necessarily or exclusively, Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) layers) and the, 'lower' DU layers (for example, but not necessarily or exclusively, Radio Link Control (RLC), Media (sometimes referred to as 'Medium') Access Control (MAC), and Physical (PHY) layers) are separated between a particular CU, and one or more DUs that are connected to and controlled by that CU via the F1 interface. Thus, for example, the higher layer CU functionality for a number of gNBs may be implemented centrally (for example, by a single processing unit, or in a cloud-based or virtualised system), whilst retaining the lower layer DU functionality locally separately for each gNB.

[0006] In more recently proposed RAN distributed architectures, in addition to the CU and DU, the concept of a Radio Unit (RU) - sometimes referred to as a 'remote unit' - has been introduced. In this architecture the RU is responsible for handling the digital front end (DFE), digital beamforming functionality and, typically, the functionality of the lower parts of the PHY layer, whilst the DU typically handles the higher parts of the PHY layer and the RLC and MAC layers. The CU in this architecture continues to be responsible for controlling one or more DUs (each DU corresponding to a different respective gNB) and to handle higher layer signalling (typically RRC and PDCP layers).

[0007] The actual functional split between the CU and DUs (and potentially RUs where applicable) of these distributed architectures is flexible allowing the functionality to be optimised for different use cases. Effectively, the split architecture enables a 5G network to use a different distribution of protocol stacks between CU and DUs (and potentially RUs) depending on, for example, midhaul availability and network design.

[0008] The choice of how to split functions in the architecture depends on, among other things, factors related to radio network deployment scenarios, constraints and intended supported use cases. Key considerations include: the need to support a specific quality of service for each service offered and for real / non-real time applications; support of specific user density and load demand in a given geographical area; and available transport networks with different performance levels.

[0009] As cellular communication systems evolve, there is an increasing need for wireless communication networks having improved energy efficiency. A reduction in the amount of energy needed to operate a communication network beneficially reduces the environmental impact of operating the system, and also reduces the operational costs. Moreover, for battery-powered devices (for example, a UE) reduced power consumption extends the battery life of the device.

[0010] One method of achieving a more efficient communication network is to reduce the energy requirements of the radio access network part of the system. The energy consumption of the radio access network includes a dynamic part that is associated with data transmission and reception, and a static part that is associated with operations of the radio access devices that are performed even when there is no ongoing data transmission or reception. The static part may include, for example, the power required to operate a UE in a mode in which the UE is able to receive and decode a physical downlink control channel (PDCCH) transmitted by a base station. Energy saving modes may be configured for one or more devices in the system (e.g., a UE). For example, a UE may be configured to operate in an energy saving mode (which may also be referred to as a sleep mode) in which the UE performs a reduced number of transmissions, or in which the UE is configured not to attempt to transmit or receive signals during a particular time period. Such operation is commonly referred to as DRX / DTX which stands for Discontinuous Reception (DRX) and Discontinuous Transmission (DTX).

[0011] Many proposals have been made for UE DTX / DRX operation and attention is turning now to such discontinuous operation of the cell or cells provided by the base station - which is referred to as "cell DTX / DRX". With cell DTX / DRX, the RAN node operating a cell stops transmitting and receiving in that cell during certain periods of time and the UEs that are served by the cell should know when the RAN node is in the active state (and is therefore able to communicate with the UE) and when it is in the inactive state (and is therefore not able to communicate with the UE).

[0012] NPL 1: Next Generation Mobile Networks (NGMN) Alliance, 'NGMN 5G White Paper' V1.0, February 17, 2015 <https: / / www.ngmn.org / 5g-white-paper.html>

[0013] Nevertheless, there are a number of issues related to cell DTX / DRX that still need addressing. These include, but are not limited to, how to perform activation / deactivation of a cell DTX and / or DRX configuration at the UE, what happens in the event of a mismatch between a base station's and a UE's understanding of whether or not a cell DTX and / or DRX configuration is active, how to ensure a base station can distinguish appropriately between legacy UEs and those that can operate in a manner that takes account of call DTX / DRX, etc.

[0014] There is therefore a need to address these and other NES / cell DTX / DRX related issues. The present specification aims to disclose apparatus and methods that at least contribute to addressing one or more of the above needs and / or issues.

[0015] The various functional means described below that are part of the UE may be provided by a memory and one or more processors that execute instructions stored in the memory. Similarly, the various functional means described below that are part of the access network node may be provided by a memory and one or more processors that execute instructions stored in the memory.

[0016] Various example described below may be implemented by means of a computer program product comprising computer implementable instructions for causing a programmable computer to carry out the any of the methods described below. The computer implementable instructions may be provided as a signal or on a tangible computer readable medium.

[0017] Examples of apparatus and methods will now be described, by way of example, with reference to the accompanying drawings in which:Fig. 1 schematically illustrates a mobile ('cellular' or 'wireless') communication system;Fig. 2 illustrates a typical frame structure that may be used in the communication system of Fig. 1;Fig. 3 illustrates a typical resource grid that may be used in the communication system of Fig.1;Fig. 4 is a simplified illustration of a slot comprising a plurality of CORESETS that may be used in the communication system of Fig. 1;Fig. 5 is a simplified illustration of the relationship between a PDCCH candidate and the various different groupings of resources that may be used in the communication system of Fig. 1;Fig. 6 illustrates an example of a DRX / DTX cycle or pattern that may be used in the communication system of Fig. 1;Fig. 7 is a simplified sequence diagram illustrating a procedure that may be employed in the communication system of Fig. 1;Fig. 8 is a simplified sequence diagram illustrating procedures for cell DTX / DRX that may be employed in the communication system of Fig. 1;Fig. 9 is a simplified sequence diagram illustrating an RRC configuration that may be employed in the communication system of Fig. 1;Fig. 10 is a simplified sequence diagram illustrating a UE capability indication procedure that may be employed in the communication system of Fig. 1;Fig. 11 is a simplified sequence diagram illustrating a number of UE fallback behaviours that may be employed in the communication system of Fig. 1;Fig. 12 is a schematic block diagram illustrating the main components of a UE for the communication system of Fig. 1; andFig. 13 is a schematic block diagram illustrating the main components of a base station for the communication system of Fig. 1.

[0018] Overview 　　An exemplary communication system will now be described in general terms, by way of example only, with reference to Figs. 1 to 6.

[0019] Fig. 1 schematically illustrates a mobile ('cellular' or 'wireless') communication system 1 to which the examples described herein are applicable.

[0020] In the communication system 1 user equipment (UEs) 3-1, 3-2, 3-3 (e.g., mobile telephones and / or other mobile or stationary devices) can communicate with each other via a radio access network (RAN) node 5 that operates according to one or more compatible radio access technologies (RATs). In the illustrated example, the RAN node 5 comprises a base station 5 or 'gNB' 5 operating one or more associated cells 9. Communication via the base station 5 is typically routed through a core network 7 (e.g., a 5G / 6G or later generation core network or evolved packet core network (EPC)).

[0021] As those skilled in the art will appreciate, whilst three UEs 3 and one base station 5 are shown in Fig. 1 for illustration purposes, the system, when implemented, will typically include other base stations 5 and UEs 3.

[0022] Each base station 5 controls one or more associated cells 9 either directly, or indirectly via one or more other nodes (such as home base stations, relays, remote radio heads, distributed units, and / or the like). It will be appreciated that the base stations 5 may be configured to support 4G, 5G, 6G and / or later generation, and / or any other 3GPP or non-3GPP communication protocols.

[0023] The UEs 3 and their serving base station 5 are connected via an appropriate air interface (for example the so-called 'Uu' interface and / or the like). Neighbouring base stations 5 may be connected to each other via an appropriate base station to base station interface (such as the so-called 'X2' interface, 'Xn' interface and / or the like).

[0024] The core network 7 includes a number of logical nodes (or 'functions') for supporting communication in the communication system 1. In this example, the core network 7 comprises control plane functions (CPFs) 10 and one or more network node entities for the communication of user data (e.g. user plane functions (UPFs)) 11. The CPFs 10 include one or more network node entities for the communication of control signalling (e.g. Access and Mobility Management Functions (AMFs)) 10-1, one or more network node entities for session management (e.g. Session Management Functions (SMFs)) 10-2 and a number of other functions 10-n (such as, for example an Authentication Server Function (AUSF) which facilitates security processes).

[0025] The base station 5 is connected to the core network nodes via appropriate interfaces (or 'reference points') such as an N2 reference point between the base station 5 and the AMF 10-1 for the communication of control signalling, and an N3 reference point between the base station 5 and each UPF 11 for the communication of user data. The UEs 3 are each connected to the AMF 10-1 via a non-access stratum (NAS) connection over an appropriate reference point (e.g. an N1 reference point (analogous to the S1 reference point in LTE)). It will be appreciated that N1 communications are routed transparently via the base station 5.

[0026] Each UPF 11 is connected to an external data network 20 (e.g., an IP network such as the internet) via an appropriate reference point (e.g. N6 reference point) for communication of the user data.

[0027] The AMF 10-1 performs mobility management related functions, maintains the NAS connection with each UE 3 and manages UE registration. The AMF 10-1 is also responsible for managing paging. The AMF 10-1 receives user information sent through the network and forwards the information to the SMF 10-2. The AMF 10-1 is also responsible for managing paging.

[0028] The SMF 10-2 provides session management functionality (that formed part of MME functionality in LTE) and additionally combines some control plane functions (provided by the serving gateway and packet data network gateway in LTE). The SMF 10-2 uses user information provided via the AMF 10-1 to determine what session manager would be best assigned to the user. The SMF 10-2 may be considered effectively to be a gateway from the user plane to the control plane of the network. The SMF 10-2 also allocates IP addresses to each UE 3.

[0029] The base station 5 of the communication system 1 is configured to operate at least one cell 9 on an associated time-division duplex (TDD) carrier that operates in unpaired spectrum and / or at least one cell 9 on an associated frequency-division duplex (FDD) carrier that operates in paired spectrum.

[0030] The base station 5 is also configured for transmission of, and the UEs 3 are configured for the reception of, control information and user data via a number of downlink (DL) physical channels. The DL physical channels correspond to resource elements (REs) carrying information originated from a higher layer.

[0031] The DL physical channels may include, for example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). The PDSCH carries data sharing the PDSCH's capacity on a time and frequency basis. The PDSCH can carry a variety of items of data including, for example, user data, UE-specific higher layer control messages mapped down from higher channels, system information blocks (SIBs), and paging. The PDCCH carries downlink control information (DCI) for supporting a number of functions including, for example, scheduling the downlink transmissions on the PDSCH and also the uplink data transmissions on a physical uplink shared channel (PUSCH). The PBCH provides UEs 3 with the Master Information Block, MIB. It also, in conjunction with the PDCCH, supports the synchronisation of time and frequency, which aids cell acquisition, selection and re-selection.

[0032] The base station 5 also transmits DL physical signals that do not carry any data, such as, for example, reference signals (RSs) and synchronization signals (SSs). A reference signal (sometimes known as a pilot signal) is a signal with a predefined special waveform known to both the UE 3 and the base station 5. The reference signals may include, for example, cell specific reference signals, UE-specific reference signal (UE-RS), downlink demodulation signals (DMRS), and channel state information reference signal (CSI-RS).

[0033] Similarly, the UEs 3 are configured for transmission of, and the base station 5 is configured for the reception of, control information and user data via a number of uplink (UL) physical channels corresponding to REs carrying information originated from a higher layer, and UL physical signals which are used in the physical layer and correspond to REs which do not carry information originated from a higher layer. The physical channels may include, for example, the PUSCH, a physical uplink control channel (PUCCH), and / or a physical random-access channel (PRACH). The UL physical signals may include, for example, demodulation reference signals (DMRS) for an UL control / data signal, and / or sounding reference signals (SRS) used for UL channel measurement.

[0034] The base station 5 is also configured to transmit synchronisation signal blocks (SSBs) periodically in the cell or cells 9 that it operates. The SSB includes both synchronisation signals (e.g., a primary synchronisation signal (PSS) and a secondary synchronisation signal (SSS)) and the PBCH carrying a MIB that provides at least part of the minimum system information for accessing the corresponding cell 9 (e.g., parameters required for acquiring system information block 1 (SIB1) which carries other minimum system information).

[0035] Each UE 3 is configured to search for SSBs when scanning for a cell to camp on and to decode the associated PBCH before proceeding to decode other system information transmitted on the PDSCH. Each UE 3 is also configured to perform measurements on specific resources configured for the SSBs, for example reference signal received power (RSRP), reference signal received quality (RSRQ), and / or signal to interference and noise ratio (SINR) measurements or the like.

[0036] Frame Structure 　　Referring to Fig. 2, which illustrates the typical frame structure that may be used in the communication system 1, the base station 5 and UEs 3 of the communication system 1 communicate with one another using resources that are organised, in the time domain, into frames in this case of length 10ms. Each frame comprises ten equally sized subframes of 1 ms length. Each subframe is divided into one or more slots comprising 14 (or in some cases 12) orthogonal frequency-division multiplexing (OFDM) symbols of equal length.

[0037] As seen in Fig. 2, the communication system 1 supports multiple different numerologies (subcarrier spacing (SCS), slot lengths and hence OFDM symbol lengths). Specifically, each numerology is identified by a parameter, μ, where μ=0 represents 15 kHz (corresponding to the LTE SCS). Currently, the SCS for other values of μ can, in effect, be derived from μ=0 by scaling up in powers of 2 (i.e., SCS = 15 x 2μkHz). The relationship between the parameter, μ, and SCS (Δf) is as shown in Table 1:

[0038] Fig. 3 illustrates the resource grid of a subframe shown in Fig. 2 (which may be equivalent to one or more slots). As shown, the subcarrier spacing, and the number of OFDM symbols within a subframe varies depending on the numerology. A single block shown in Fig. 3 corresponds to a single RE and this is the smallest unit of the resource grid and is made up of one subcarrier in the frequency domain and one symbol in the time domain. A resource block 25 is defined only for the frequency domain and is defined as twelve consecutive subcarriers in the frequency domain in one symbol.

[0039] Control Information 　　In the communication system. the base station 5 is configured to transmit control information to the UE 3 using one or more control resource sets (CORESETs). A CORESET is a set of time-frequency resources within which the UE 3 can search for DCI transmitted by a base station on a PDCCH. A CORESET is analogous to the control region at the start of subframes in earlier generations of communication technology. Unlike earlier generations, however, in which the frequency domain of the control region typically corresponded to the total system bandwidth, the frequency domain location for CORESET is localised to a specific region in the frequency domain and has a variable width that can be set to any suitable value (typically in multiples of six resource blocks where each resource block comprises twelve subcarriers in the frequency domain).

[0040] Fig. 4 is a simplified illustration of a slot comprising a plurality of CORESETS in the communication system of Fig. 1, and Fig. 5 is a simplified illustration of the relationship between a PDCCH candidate and the various different groupings of resources in the communication system of Fig. 1.

[0041] As seen in Fig. 4, the base station 5 of the communication system 1, can configure a UE 3 with one or more CORESETs 410 comprising a set of time-frequency resources in which the UE 3 can search for DCI transmitted by the base station 5 on a PDCCH. Each CORESET may be up to 3 OFDM symbols in length. The CORESET configured for a UE 3 will typically include one or more UE specific CORESETs configured, for example, by RRC signalling, and one or more common CORESETs configured by system information, for example, by a master information block (MIB). For example, the base station 5 is configured to use the MIB to configure an initial CORESET (CORESET 0) in which to search for a PDCCH providing scheduling for the physical PDSCH providing system information block type 1 (SIB1).

[0042] The base station 5 may therefore transmit DCI for a specific UE 3 in a PDCCH that uses the resources of a UE specific CORESET defined for that UE 3.

[0043] As seen in Fig. 5, a PDCCH is made up of a number of (typically 1, 2, 4, 8, 16) control channel elements (CCEs) depending on the required aggregation level (L ∈ {1, 2, 4, 8, 16}). Each CCE is made up of a number of (typically 1, 2 or 3) resource element group bundles (REG bundles) each comprising a number of resource element groups (REGs) made up of REs. Each RE is effectively the smallest unit of the resource grid and is made up of one subcarrier in the frequency domain and one OFDM symbol in time domain. A REG corresponds to one resource block (i.e., 12 REs / subcarriers) in the frequency domain and one OFDM symbol in time domain.

[0044] A number of different DCI formats can be used by the base station 5, depending on requirements, for transmission on a PDCCH corresponding to one of the PDCCH candidates in one of the search spaces configured for a given UE 3. For example, the base station 5 may be able to transmit DCI using one or more of the currently standardised DCI formats as set out in Table 2.

[0045] Different DCI formats may or may not have the same DCI size. Moreover, DCI may be addressed (scrambled) using different radio network temporary identifiers (RNTIs) that a UE 3 may monitor for. Typically, a UE 3 is capable of monitoring up to three different DCI sizes for DCI formats using a cell RNTI (C-RNTI) - typically used as an identifier for scheduling purposes. Additionally, a UE 3 is typically capable of monitoring one additional DCI size using other RNTIs for specific purposes (e.g., a slot format indication RNTI (SFI-RNTI), interruption RNTI (INT-RNTI), or the like). This constraint is sometimes referred to as the "3+1" size budget and is imposed because a DCI scrambled with a C-RNTI is, generally, more time critical than a DCI scrambled with a RNTI used for another specific purpose, and so requires the UE 3 to decode it promptly in order to be able to process the scheduled data transmission.

[0046] To take account of the constraint imposed by the DCI size budget, the sizes of some DCI formats may be aligned by padding, truncation, and / or determining a frequency domain resource assignment field differently.

[0047] A UE 3 may monitor a set of PDCCH candidates in one or more control resource sets (CORESETs) on an active DL bandwidth part, where monitoring implies decoding each PDCCH candidate according to the monitored DCI formats. The number of blind decodes (BDs) may be restricted on a per carrier basis of a serving cell. The number of BDs may refer to the number of monitored PDCCH candidates or the number of PDCCH candidates a UE is capable of decoding within a certain time frame, such as a slot or span of consecutive symbols in a slot. As an example, at a 15 kHz subcarrier spacing (SCS), the maximum number of BDs per slot per serving cell supported by a UE 3 may be 44 BDs.

[0048] General DTX / DRX 　　A UE 3 may be configured to operate using a discontinuous reception (DRX) method. In a DRX method, the UE 3 is configured with a DRX configuration that includes a DRX pattern and a periodicity (DRX cycle) and optionally a number of DRX cycles. The DRX pattern defines "ON durations" in which the UE 3 is configured for receiving transmissions and "OFF durations" in which the UE 3 is not configured for receiving transmissions (e.g., transmissions from a base station 5). During the OFF durations the physical layer processing may be turned off within the UE 3. Advantageously, the energy consumption of the UE 3 is reduced in the periods in which the UE 3 is not configured for receiving transmissions.

[0049] The UE 3 is typically provided with its DRX configuration by or via the base station 5. A DRX configuration provided to the UE 3 (for example, using a DRX configuration information element (IE) included in a transmission from the base station 5 to the UE 3) may include, as mentioned above, an indication of a time period (OFF duration) for which the UE 3 is to be configured in a state in which the UE 3 does not receive and decode downlink transmissions, and an indication of a time period (ON duration) for which the UE 3 is to be configured for receiving downlink transmissions (e.g., a multicast or unicast transmission from the base station 5). The DRX configuration may also include a time offset, which may be useful for controlling the relative timing of the DRX configurations of different UEs 3 (e.g., to synchronise or offset the DRX patterns). The DRX configuration may also include an indication of a time period in which the UE is to remain configured for receiving transmissions following the reception of a PDCCH.

[0050] The ON duration may also be referred to as the 'DRX active time', and the OFF duration may also be referred to as a 'sleep period', or a 'DRX inactive time'. An example of a DRX pattern having an ON duration of t1, and an OFF duration of t2, and which is repeated in accordance with a DRX cycle is illustrated in Fig. 6.

[0051] DRX may be configured per UE 3 by the network (e.g., via any suitable signalling from the base station 5). For example, the timing and / or duration of the ON durations in the DRX cycle may be different for different UEs 3. During the OFF durations, the UE 3 may be configured to not monitor a PDCCH but may initiate an uplink transmission based on configured resources (for example, using a PUCCH, a random access channel (RACH), scheduling request (SR) or a configured grant PUSCH (CG-PUSCH)). During an OFF duration, the system may be configured for no transmission / reception between the UE 3 and the base station 5 in a corresponding cell. The base station 5 may nevertheless be configured for reduced or limited transmission / reception in the cell during the OFF duration of the DRX cycle. For example, the base station 5 may be configured to transmit only a subset of periodic signals or channels, such as common channels / signals or UE-specific channels / signals that would normally be transmitted in the cell.

[0052] DRX may be used when the UE 3 is in an RRC idle mode or when the UE 3 is in an RRC connected mode. For example, DRX may be used when the UE 3 is in an RRC idle mode to control the monitoring of paging messages transmitted by the base station 5. This advantageously prevents the UE 3 from monitoring all of the PDCCH transmission opportunities, thereby reducing the energy usage of the UE 3. Similarly, DRX may be used when the UE 3 is in the RRC connected state (referred to as connected mode DRX or 'C-DRX') to reduce the energy usage of the UE 3, for example by configuring periods in which the UE 3 is not required to monitor a PDCCH.

[0053] Within a C-DRX cycle, when the UE 3 is in an RRC connected state, the UE 3 periodically monitors the PDCCH during the ON durations, and does not monitor PDCCH outside of the ON durations (i.e., in the DRX inactive periods), thereby beneficially reducing the power consumption of the UE 3. Currently, during a C-DRX inactive time, the UE 3 is allowed to initiate an uplink transmission based on configured resources (for example, using a PUCCH, a random access channel (RACH), scheduling request (SR) or on a configured grant PUSCH (CG-PUSCH)).

[0054] A DRX configuration may also include a long DRX cycle in which the time between the ON durations is relatively large (t2 shown in Fig. 6 is relatively large), and a short DRX cycle in which the time between the ON durations is relatively small (t2 shown in Fig. 6 is relatively small). Whilst the long DRX cycle improves the energy efficiency of the system (because the overall percentage of time in which the UE 3 is in the ON state is smaller), latency of communications may be increased because the base station 5 cannot communicate with the UE 3 via downlink transmissions when the UE 3 is in the sleep state (the DRX inactive state). When the UE 3 is configured to use DRX after a period of inactivity following a data transfer, the UE 3 may be configured to initially use the short DRX cycle configuration, and after a further period of time (which may be defined by a Short DRX Cycle timer) the UE 3 may then operate using the long DRX cycle configuration. The short and long DRX configurations may be indicated to the UE 3, for example, using any suitable signalling from the base station 5 (or alternatively could be preconfigured in the UE 3).

[0055] Whilst DRX has been described above with reference to discontinuous reception performed by the UE 3, a similar DTX pattern can be defined to control the discontinuous transmission of data by the UE 3. When defined, the UE DTX pattern typically overlaps with the UE DRX pattern - so that when the UE 3 is not receiving data it is also normally not transmitting data.

[0056] Cell DTX / DRX 　　As mentioned above, a base station 5 may also operate one or more of its cells in a DTX / DRX mode in substantially the same way as UE DTX / DRX - stopping the base station's transmissions and receptions during periods of time (OFF duration) when the base station 5 is inactive or asleep and resuming transmissions and receptions with the UEs 3 during periods of time (ON duration) when the base station 5 is active. The cell DTX / DRX configuration can be defined by a number of parameters such as the periodicity (DRX cycle), the start slot / offset, the ON duration (t1), the OFF duration (t2) and the number of cycles etc. as shown in Fig 4.

[0057] The periodic cell DTX / DRX configuration may be explicitly signalled to the UEs 3. For example, in the communication system 1, one or more periodic cell DTX / DRX configurations comprising one or more periodic cell DTX / DRX patterns may be configured by UE specific (dedicated) signalling (e.g., RRC signalling). It will be appreciated, however, that cell DTX and cell DRX modes may be configured and operated separately (e.g., one (RRC) configuration set may be provided for the DL and another configuration set may be for provided for the UL). Nevertheless, (common) cell DTX / DRX may also be configured and operated together. It will be appreciated that the network may, or may not, allow legacy UEs to access cells with Cell DTX / DRX. Cell DTX / DRX may be configured on a per serving cell basis and may be applicable for different cells in carrier aggregation (CA).

[0058] As a baseline, a given cell DTX / DRX configuration may be activated / deactivated implicitly by the configuration signalling (e.g., activated immediately once configured by an RRC configuration and deactivated once the RRC configuration is released). Nevertheless, a periodic cell DTX / DRX configuration may beneficially be explicitly activated / deactivated by L1 (or possibly L2) signalling and / or UE specific signalling.

[0059] Specifically, the communication system beneficially supports dynamic signalling (e.g., layer 1 (L1) / physical (PHY) layer signalling) by the base station 5, for at least activation / deactivation of a cell DTX and / or a cell DRX configuration at the UE 3 (e.g., in terms of enabling / disabling the cell DTX / DRX). In the exemplary communication system 1, this is achieved by means of L1 signalling that is addressable to one or more UEs (e.g., using group common signalling), using a PDCCH, for cell DTX / DRX activation / deactivation (in this example without hybrid automatic repeat request (HARQ) feedback). Specifically, DCI based in accordance with a new DCI format for the purpose of cell DTX / DRX activation / deactivation is used to provide the indication for cell DTX / DRX activation / deactivation. The new DCI format is referred to herein as 'DCI format 2_X' for convenience but may be called something different when implemented. The DCI format 2_X may, for example, be similar to DCI Formats 2_0, 2_1, 2_2 and 2_3 that are designed to address a group of UEs 3 and can accommodate payloads for each UE within the group (e.g., with the payload for a specific UE 3 having a specific position within the DCI so that each UE 3 is able to extract its own information while ignoring the information intended for other UEs 3).

[0060] The DCI format 2_X is configured to ensure that the DCI size budget and the number of required BDs is not increased. Moreover, a PDCCH monitoring configuration for the new DCI format may be identical to a PDCCH monitoring configuration for an existing DCI format (e.g., DCI format 2_6) if the UE monitors both DCI formats. A new DTX / DRX activation / deactivation specific RNTI may be used for base station scrambling / UE monitoring of the DCI format 2_X. Nevertheless, an existing RNTI could potentially be reused.

[0061] The group common (e.g., L1) signalling supports activation / deactivation of a respective configuration for each of a plurality of 'blocks' where each block corresponds to a different cell 'group' (where each 'group' may include one or more cells). Specifically, the DCI format 2_X supports the provision of a respective indication of activation / deactivation of a DTX / DRX configuration, for each of a plurality of 'cell DTX / DRX' blocks (e.g., Block number 1, block number 2, …, block number N). For each block, the DCI format 2_X may include a respective DCI field that supports separate activation / deactivation for a DTX configuration, and for a DRX configuration, for the cell or cells corresponding to that block.

[0062] Beneficially, as described in more detail later, the mapping of the UE 3 to each DTX / DRX block (which may respectively correspond to different cell groups) is configurable by dedicated (e.g., RRC) signalling sent from the base station 5 to each UE 3.

[0063] It will be appreciated that, while the communication system 1 is described primarily in the context of dynamic signalling in the form of L1 / PHY / PDCCH signalling, alternatively or additionally layer 2 (L2) / MAC layer signalling may be used for dynamic activation / deactivation of cell DTX and / or cell DRX (e.g., by means of an appropriately configured MAC control element (CE) based indication). It will also be appreciated that the provision of this signalling, the type of signalling used, and / or the specific information signalled may be dependent on a capability of the UE 3 to support cell DTX / DRX, or specific cell DTX / DRX features (e.g., as indicated via UE capability information provided by the UE 3 to the base station 5).

[0064] Moreover, whilst a DTX / DRX configuration may be activated / deactivated implicitly by UE specific signalling (e.g., an RRC reconfiguration message), in the communication system 1, for each cell, a cell DTX configuration / DRX configuration may respectively define a plurality of DTX patterns and / or DRX patterns, which may be activated / deactivated explicitly by the UE dedicated signalling. For example, for each defined pattern (or each DTX pattern / DRX pattern pair) a suitable field in the configuration (e.g., RRC reconfiguration) message may be used to respectively indicate (explicitly) whether that pattern is enabled / disabled (or activated / deactivated).

[0065] Mapping of UE and block number 　　As mentioned above, the mapping of the UE 3 to each block (which may respectively correspond to different cell groups) is configurable by dedicated (e.g., RRC) signalling sent from the base station 5 to each UE 3. The mapping will now be described by way of example only, with reference to Fig. 7, which is a simplified sequence diagram illustrating a procedure that may be employed in the communication system 1.

[0066] As seen in Fig. 7, a cell group (which may include one or more cells) is allocated a DTX / DRX block number (e.g., one of the numbers 0 to 7 where there are eight blocks) at S710. The same block number is, therefore, effectively allocated to each cell of the cell group. An illustrative example of a possible mapping is shown, by way of example only, in the mapping table below (Table 3).

[0067] Each UE 3 that is configured to communicate in at least one cell that is within a cell group is allocated (mapped to) the DTX / DRX block number that has been allocated to that cell group (as seen as S712a to S712c). It will be appreciated that, in a case where a UE 3 is configured to communicate in multiple cells, and at least two of those cells are associated with different block numbers, the UE 3 may be allocated (mapped to) multiple blocks.

[0068] The block value (or block values) of the 'N' (e.g., 8) possible values used by DCI format 2_X for activation / deactivation that is applicable for a given UE 3 may, for example, be specified by RRC signalling, for example by an information element (IE) / field of an RRC reconfiguration message or the like.

[0069] The block value (or values) for a particular UE may, for example, be indicated as part of a dedicated IE for cell index to block number mapping for the DCI format 2_X (e.g., a CellIndexAndBlockMappingforDCI2X IE), which maps one or more lists of one or more cell identifiers / indices (e.g., in the form of a list of one or more cell indices (e.g., a CellIndexList IE including a sequence of one or more CellIndex IEs) to a specific block number (e.g., in a BlockNumber IE indicating a specific block from a set of possible blocks ( e.g., BLOCK0, BLOCK1, BLOCK2, BLOCK3, BLOCK4, BLOCK5, BLOCK6, BLOCK7))).

[0070] By way of illustration only, an example of simplified abstract syntax notation number One (ASN.1) notation for such and IE / field (with explanatory comments) is as follows:

[0071] It will be appreciated that the size of the sequence of block numbers will correspond to the number of blocks which, in this example, it is eight (but may be any suitable number).

[0072] It will be appreciated that the total number of blocks can, itself, be configurable, e.g., from a group of possible values (e.g., {2, 4, 8, etc …}).

[0073] DCI (DCI format 2_X) for activation / deactivation 　　As mentioned above, a DCI format (referred to as 'DCI format 2_X' for convenience) for the purpose of cell DTX / DRX activation / deactivation is used to provide the indication for cell DTX / DRX activation / deactivation. Possible information carried by DCI that uses DCI format 2_X will now be described by way of example only, with reference to Fig. 8, which is a simplified sequence diagram illustrating different procedures for cell DTX / DRX that may be employed in the communication system 1.

[0074] As seen in Fig. 8, when a decision is made to activate or deactivate a cell DTX configuration and / or a cell DRX configuration (as seen at S810), the content of the DCI field may vary depending on the way in which cell DTX and cell DRX are respectively configured (e.g., by RRC signalling such as an RRC (re)configuration message or the like).

[0075] For example, as seen at S812a, if the cell DTX configuration and cell DRX configuration are fully independent of one another (e.g., having their own separate pattern definitions), then a DCI field (e.g., an activation / deactivation field) may include a single bit to activate / deactivate the cell DTX configuration and another single bit to activate / deactivate cell DRX configuration (as seen at S814a). It will, nevertheless, be appreciated that it is possible that more than one (independent) cell DTX configuration and (independent) cell DRX configuration will be configured (e.g., via dedicated (RRC) signalling). In such a case there may be a respective bit for each independent cell DTX configuration and for each independent cell DRX configuration.

[0076] As seen at S812b, if the cell DTX configuration and cell DRX configuration are jointly configured, for example as an aligned / paired cell DRX / DTX configuration ( e.g., in which only a start offset for the DTX pattern is different to the start offset for the DRX pattern), then a DCI field (e.g., an activation / deactivation field) may include a single bit to activate / deactivate the aligned / paired cell DRX / DTX configuration (as seen at S814b).

[0077] It will be appreciated that in each of the above examples, for each cell DTX, cell DRX pattern, and / or joint cell DTX / DRX pattern a bit value set to '1' may indicate activation and a bit value set to '0' may indicate deactivation - or vice versa.

[0078] It will also be appreciated that for multiple cell DTX and / or DRX pattern configurations one or more bitmaps may be used in the DCI field (e.g., the activation / deactivation field). For example, to support activation / deactivation of up to two independently configured DTX / DRX patterns (e.g., at S814a), a four-bit DCI field (or two two-bit fields) may be used with two bits corresponding to activation / deactivation of up to two cell DTX patterns and two bits corresponding to activation / deactivation of up to two cell DRX patterns. Similarly, for example, to support activation / deactivation of up to three jointly configured DTX / DRX patterns (in which cell DTX / DRX configuration pairs are jointly activated / deactivated) a three-bit DCI field may be used.

[0079] Nevertheless, whilst having a different respective bit for each cell DTX, cell DRX pattern, and / or joint cell DTX / DRX pattern has benefits in terms of simplicity and ease of implementation, a smaller DCI field having fewer bits than the maximum number of cell DTX, cell DRX pattern, and / or joint cell DTX / DRX pattern could potentially be used. For example, to support activation / deactivation of up to three jointly configured cell DTX / DRX patterns a two-bit DCI field may be used where each of the four different possible bit combinations either indicates activation of a different respective one of the cell DTX / DRX patterns (and possibly implicit deactivation of the others), or that no cell DTX / DRX patterns are activated (or all cell DTX / DRX patterns are deactivated). Each combination of bits may, for example, correspond to a respective index (i.e., #0-#3) corresponding either to no cell DTX / DRX or to activation of a specific cell DTX / DRX pattern as indicated in Table 4.

[0080] Other possible DCI fields 　　PUCCH resource indicator (PRI) 　　Beneficially, the DCI format may be configured to provide support for the possibility of high priority UL transmissions (e.g., via the PUCCH) during a cell DRX non-active period (i.e., when the base station 5 is not expected to be receiving). Specifically, the DCI format may include an optional field for indicating one or more resources that can be used for the UL transmission from the UE 3. The indication may, for example, be a PUCCH resource indicator (PRI) index (or the like) having a sufficient number of bits (e.g., 3 bits) to point to one or more resources preconfigured at the UE 3, or to a row in a standardised look-up table (e.g., in conjunction with the first CCE used by the PDCCH). Advantageously, the specified UL (e.g., PUCCH) resources may have the same time domain allocation across the DTX / DRX blocks that the DCI is configuring cell DTX / DRX for (e.g., having the same start symbol and number of symbols).

[0081] It will be appreciated that a default allocation, or a fallback PUCCH resource, for use during the non-active period may be indicated. Moreover, where the base station 5 operates a cell group including a plurality of different cells, a different respective PRI index may be provided for each cell within the cell group (i.e., multiple indications may be provided with at least one indication for each cell). Alternatively, a single PRI index may be used for all cells within a cell group. It will also be appreciated that the base station 5 may be capable of using both of these options (multiple or single indications) and of determining which of the options to use at a given time.

[0082] Accordingly, if a PUCCH UL transmission is needed during a serving cell's non-active period, for example for a high priority scheduling request (SR), or for a HARQ acknowledgement / negative acknowledgement (ACK / NACK), the PRI indicated in the DCI may be used by the UE 3 to identify the correct PUCCH resource.

[0083] One or more of the UEs 3 may be configured for performing uplink TX switching in which a UE 3 can dynamically switch its UL transmissions between different carriers / cells. For a UE 3 that is configured for uplink switching, the indicated PRI may also be used for PUCCH switching (e.g., if a new / target cell to which UL switching is performed is active and not in cell DRX). The UE 3 may, for example, be configured for uplink switching by means of an appropriate with parameter (e.g., an "uplinkTxSwitching" in an uplink configuration provided as part of a serving cell configuration for the UE using appropriate signalling (e.g., RRC reconfiguration or the like)).

[0084] CORESET / common search space (CSS) indication / index 　　Beneficially, the DCI format may be configured to provide support for default or fallback PDCCH monitoring during a cell DTX non-active period (i.e., when the base station 5 is not expected to be transmitting).

[0085] Specifically, for the purposes of monitoring during a cell DTX non-active period, a PDCCH monitoring occasion may be configured that allows for a longer interval (e.g., between monitoring occasions) and / or a shorter length of time for PDCCH monitoring to occur (e.g., a relatively short cell DTX cycle with a relatively long cell DTX non-active duration compared to a 'normal' cell DTX pattern). The communication system 1 supports configuration of a common search space (CSS) (e.g., a cell DTX / DRX search space) within which to monitor for a PDCCH, and the transmission of a joint indication (to a group of UEs) of the CSS to reduce time domain transmission time / monitoring occasions for a group of UEs. The indicated CSS may then be monitored for fallback during a cell DTX / DRX non-active period only.

[0086] In more detail, the DCI format may include an optional field for indicating a CORESET and / or common search space (CSS) set that may be used for the default or fallback PDCCH monitoring during a cell DTX non-active period.

[0087] It will be appreciated that, where the base station 5 operates a cell group including a plurality of different cells, a different respective CORESET / SS index may be provided for each cell within the cell group (i.e., multiple indications may be provided with at least one indication for each cell). Alternatively, a single CORESET / SS index may be used for all cells within a cell group. It will also be appreciated that the base station 5 may be capable of using both of these options (multiple or single indications) and of determining which of the options to use at a given time.

[0088] Cell DTX / DRX activation / deactivation monitoring during cell DTX non-active period 　　Beneficially, the DCI format may be configured to provide support for an indication (e.g., a one-bit field / flag) of whether or not monitoring for cell DTX / DRX activation / deactivation can be skipped during a non-active period of cell DTX for the group of cells (i.e., whether or not the cell DTX / DRX search space will be monitored). If the indication is not set (to indicate that monitoring can be skipped), cell DTX / DRX activation will be monitored during the cell DTX non-active period for the group of cells.

[0089] RRC Configuration 　　As mentioned above, where an RRC configuration message configures cell DTX / DRX, as a baseline, the cell DTX / DRX configuration may be activated immediately. Beneficially, in the communication system 1, the RRC configuration message is configurable to define one or more cell DTX / DRX patterns for each cell (e.g., of a cell group). Moreover, the RRC configuration message is configurable to indicate, for each cell DTX / DRX pattern whether that pattern is 'enabled' or 'disabled'. A procedure for possible RRC configuration will now be described by way of example only, with reference to Fig. 9, which is a simplified sequence diagram illustrating an RRC configuration that may be employed in the communication system 1.

[0090] Specifically, as seen in Fig. 9, when an RRC configuration message is sent, the RRC configuration is configurable to include a configured cell list (e.g., a 'ConfiguredCellList' IE) that includes configuration information for each cell. For each cell, a cell DTX Config / DRX Config sequence is configurable where each element in the sequence represents a respective instance of a DTX / DRX pattern configuration (e.g., in an information element defining a "sequence {1 to n instances of rrcDtxDrxPatternConfig}"). It will be appreciated that there may be one or more elements in the sequence subject to an appropriate maximum (e.g., n=3, n=4, or the like). For each instance, the RRC configuration is configurable to indicate whether the pattern is enabled or disabled (e.g., {enabled, disabled}). Moreover, the definition of each pattern may include one or more of the following: -　　A cell DTX cycle (e.g., defined by a periodicity, start slot / offset, and on duration); -　　A cell DRX cycle (e.g., defined by a periodicity, start slot / offset, and on duration); and -　　A short cell DTX / DRX cycle (e.g., defined by a periodicity, start slot / offset, on duration, validity timer).

[0091] The validity timer shown as part of the short cycle cell DTX / DRX may indicate an amount of time for which the short cycle cell DTX / DRX may remain valid (i.e., until expiry of the validity timer). It will be appreciated that the validity timer may be treated as not having been set if its 'length' is zero. The short cell DTX / DRX cycle is valid during the non-active duration of the normal ('long') DTX / DRX cycle, and may last for a specified number of non-active durations of the normal ('long') cell DTX / DRX cycles before it deactivates itself. The validity timer may, therefore, be in the form of a counter value corresponding to an integer number of non-active durations of long cell DTX / DRX cycles that the short cell DTX / cycle remains valid for.

[0092] It will be appreciated that the pattern for the short cell DTX / DRX cycle may be characterised by a relatively short on duration with a relatively long non-active duration (e.g., relative to the on duration and a non-active duration for other configured 'normal' cell DTX or DRX cycles). It will also be appreciated that the same short cell DTX / DRX pattern may be configured for both cell DTX and cell DRX, a different pattern may be configured for a short cell DTX cycle than for a short cell DRX cycle, or a pattern may be configured for only one of short cell DTX and short cell DRX.

[0093] UE Capability Indication 　　Beneficially, to support cell DTX / DRX, a UE 3 having the UE functionality required to support cell DTX / DRX / NES may be configured for indicating this UE capability, for example when requested to do so by the base station 5 and / or independently when triggered internally by the UE 3. A procedure for possible UE capability procedure will now be described by way of example only, with reference to Fig. 10, which is a simplified sequence diagram illustrating a UE capability indication procedure that may be employed in the communication system 1.

[0094] As seen in Fig. 10, in this example the base station 5 sends a UE capability enquiry at S1010 to request UE capability information relating to NES and the UE responds, at S1012, with a UE capability indication including one or more feature group indicators (FGIs) indicating the capability.

[0095] The FGIs for NES may include, for example, one or more of the following: -　　A first indicator ('Indicator 1') for indicating that a cell DTX / DRX cycle is supported; -　　A second indicator ('Indicator 2') for indicating that a short cell DTX / DRX cycle is supported; and / or -　　A third indicator ('Indicator 3') for indicating that a cell DTX / DRX command MAC CE is supported.

[0096] UE Capability Indication 　　It will be appreciated that on some occasions, there a mismatch may arise between a UE 3 and base station 5 on whether or not cell DTX / DRX is activated (and / or the timing of such activation), for example due to a missed detection of the group common DCI (e.g., DCI format 2_X) for cell DTX / DRX. Beneficially, to resolve the mismatch between UE 3 and base station 5, the UE 3 may be configured with a 'fallback' behaviour. Such fallback behaviour may, for example, be beneficial for scenarios in which the UE 3 does not detect a radio link (RL) failure but is unable to receive the uplink grant for multiple retransmissions as requested, or the UE 3 may be unable to detect feedback expected from the base station 5 for its uplink transmissions.

[0097] Possible UE fallback behaviour will now be described by way of example only, with reference to Fig. 11, which is a simplified sequence diagram illustrating a number of UE fallback behaviours that may be employed in the communication system 1. It will be appreciated that any of the fallback behaviours described may be implemented together or individually.

[0098] As seen in Fig. 11 at S1110, the UE 3 may initiate a scheduling request (SR), for example via a cell DTX / DRX fallback PUCCH (e.g., as described above with reference to the PUCCH resource indicator (PRI)) or via a configured grant indicating 'cell DTX / DRX fallback'. Thus, the base station 5 is informed of the UE's cell DTX / DRX mismatch. In response, the base station 5 may resend the cell DTX / DRX activation / deactivation DCI to the UE one or more times.

[0099] As seen in Fig. 11 at S1114, the UE 3 may start a cell DTX / DRX fallback timer (TFB) corresponding to a specified 'fallback' period (this may be in addition to sending the SR or may be carried out without sending an SR). As seen at S1122, during this specified fallback period, the base station 5 may resend the cell DTX / DRX activation / deactivation DCI in the fallback search space (e.g., a fallback search space as described above in relation to the "CORESET / common search space (CSS) indication / index"). As seen at S1116, the UE 3 may deactivate the cell DTX / DRX and continuous reception from the base station 5 may be carried out at the UE 3 (e.g., to receive any DCI transmitted by the base station 5 (S1118)). Regardless of whether cell DTX / DRX is deactivated and continuous reception carried out at S1116, as seen at S1120, the UE 3 may monitor the cell DTX / DRX fallback search space for an appropriate DCI format (e.g., DCI Format 2_6) for fallback (S1122). It will be appreciated that the DCI format (e.g., DCI Format 2_6) may contain an 'activation / deactivation' field only as a fallback DCI. It will also be appreciated that the base station 5 may resend the cell DTX / DRX activation / deactivation DCI (e.g., DCI Format 2_X) in the fallback search space, for example, the base station 5 may choose to reuse the group common cell DTX / DRX activation / deactivation search space for fallback and resend the 'Cell activation / deactivation' DCI one or more times.

[0100] If the base station 5 is in, or enters, a cell DTX / DRX active duration prior to the cell DTX / DRX fallback timer expiry, it may also resend the group common DCI for cell DTX / DRX activation / deactivation in the usual common search space. If the base station 5 is in a cell DTX / DRX non-active duration, then it may send a DCI in the fallback search space.

[0101] The UE 3 will stop monitoring the fallback search space (e.g., a fallback search space as described above in relation to the "CORESET / common search space (CSS) indication / index") when the cell DTX / DRX fallback timer expires.

[0102] It will be appreciated that the base station 5 may resend a group common DCI (e.g., DCI Format 2_X) a number of times via the fallback search space.

[0103] User Equipment 　　Fig. 12 is a schematic block diagram illustrating the main components of a UE 3 as shown in Fig. 1.

[0104] As shown, the UE 3 has a transceiver circuit 1231 that is operable to transmit signals to and to receive signals from a base station 5 via one or more antenna 1233 (e.g., comprising one or more antenna elements). The UE 3 has a controller 1237 to control the operation of the UE 3. The controller 1237 is associated with a memory 1239 and is coupled to the transceiver circuit 1231. Although not necessarily required for its operation, the UE 3 might, of course, have all the usual functionality of a conventional UE 3 (e.g., a user interface 1235, such as a touch screen / keypad / microphone / speaker and / or the like for, allowing direct control by and interaction with a user) and this may be provided by any one or any combination of hardware, software, and firmware, as appropriate. Software may be pre-installed in the memory 1239 and / or may be downloaded via the communication system 1 or from a removable data storage device (RMD), for example.

[0105] The controller 1237 is configured to control overall operation of the UE 3 by, in this example, program instructions or software instructions stored within memory 1239. As shown, these software instructions include, among other things, an operating system 1241, and a communications control module 1243.

[0106] The communications control module 1243 is operable to control the communication between the UE 3 and its serving base station or base stations 5 (and other communication devices connected to the base station 5, such as further UEs and / or core network nodes). The communications control module 1243 is configured for the overall handling of uplink communications via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), random access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS). The communications control module 1243 is also configured for the overall handling of receipt of downlink communications via associated downlink channels (e.g., of DCI via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS). The communications control module 1243 is responsible, for example: for determining where to monitor for downlink control information (e.g., the location of search spaces, CORESETs, and associated PDCCH candidates to monitor); for determining the resources to be used by the UE 3 for transmission / reception of UL / DL communications (including interleaved resources and resources subject to frequency hopping); for managing frequency hopping at the UE side; for determining how slots / symbols are configured (e.g., for UL, DL or full duplex communication, or the like); for determining which bandwidth parts are configured for the UE 3; for determining how uplink transmissions should be encoded and the like.

[0107] It will be appreciated that the communications control module 1243 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. For example, the communications control module 1243 may include a PHY sub-module, a MAC sub-module, an RLC sub-module, a PDCP sub-module, an RRC sub-module, etc.

[0108] The communications control module 1243 is configured to control communications, in accordance with any of the proposals and options described including, for example: for the UE's contribution to handling configuration of cell DTX / DRX (e.g., including one or more cell DTX / DRX patterns; configuring one or more appropriate DTX / DRX blocks at the UE 3, etc.); DTX / DRX activation / deactivation (via DCI, MAC CE and / or dedicated (e.g., RRC) signalling); fallback behaviours in the context of cell DTX / DRX (e.g., monitoring of a cell DTX / DRX specific fallback search space, sending of an SR, usage of a cell DTX / DRX fallback timer, and / or the like); reception and interpretation of cell DTX / DRX related DCI and other signalling; transmission of UE capability information to the base station 5; and / or the like. The communications control module 1243 includes one or more cell DRX / DTX configurations 1245, provided by the serving base station 5, that identify the cell DRX / DTX inactive and active periods for one or more DTX / DRX patterns. As those skilled in the art will appreciate, this information is needed by the UE to control its operation in accordance with the above proposals. The communications control module 1243 also includes UE capability information 1246 which defines the UE capabilities (e.g., including the NES related capabilities) The communications control module 1243 also includes the various timers 1248 used to define the timings discussed above.

[0109] Base Station 　　Fig. 13 is a schematic block diagram illustrating the main components of the base station 5 for the communication system 1 shown in Fig. 1. As shown, the base station 5 has a transceiver circuit 1351 for transmitting signals to and for receiving signals from the communication devices (such as UEs 3) via one or more antenna 1353 (e.g., a single or multi-panel antenna array / massive antenna), and a core network interface 1355 (e.g., comprising the N2, N3 and other reference points / interfaces) for transmitting signals to and for receiving signals from network nodes in the core network 7. Although not shown, the base station 5 may also be coupled to other base stations via an appropriate interface (e.g., the so-called 'Xn' interface in NR). The base station 5 has a controller 1357 to control the operation of the base station 5. The controller 1357 is associated with a memory 1359. Software may be pre-installed in the memory 1359 and / or may be downloaded via the communication system 1 or from a removable data storage device (RMD), for example. The controller 1357 is configured to control the overall operation of the base station 5 by, in this example, program instructions or software instructions stored within memory 1359.

[0110] As shown, these software instructions include, among other things, an operating system 1361 and a communications control module 1363.

[0111] The communications control module 1363 is operable to control the communication between the base station 5 and UEs 3 and other network entities that are connected to the base station 5. The communications control module 1363 is configured for the overall control of the reception and decoding of uplink communications, via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), a random-access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS). The communications control module 1363 is also configured for the overall control of the transmission of downlink communications via associated downlink channels (e.g., via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS). The communications control module 1363 is responsible, for example: for determining where to configure the UE 3 to monitor for downlink control information (e.g., the location of search spaces, CORESETs, and associated PDCCH candidates to monitor); for determining the resources to be scheduled for UE transmission / reception of UL / DL communications (including interleaved resources and resources subject to frequency hopping); for managing frequency hopping at the base station side; for configuring slots / symbols appropriately (e.g., for UL, DL or full duplex communication, or the like); for configuring bandwidth parts for the UE 3; for providing related configuration signalling to the UE 3; and the like.

[0112] It will be appreciated that the communications control module 1363 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. For example, the communications control module 1363 may include a PHY sub-module, a MAC sub-module, an RLC sub-module, a PDCP sub-module, an RRC sub-module, etc.

[0113] The communications control module 1363 is configured to control communications, in accordance with any of the proposals and options described including, for example: for the base station's contribution to handling configuration of cell DTX / DRX (e.g., including one or more cell DTX / DRX patterns; configuring one or more appropriate DTX / DRX blocks to the UE 3, etc.); indicating DTX / DRX activation / deactivation (via DCI, MAC CE and / or dedicated (e.g., RRC) signalling); supporting UE fallback behaviours in the context of cell DTX / DRX (e.g., configuration and use of a cell DTX / DRX specific fallback search space, receipt of a fallback SR, configuration of the cell DTX / DRX fallback timer, and / or the like); generation and transmission of cell DTX / DRX related DCI and other signalling; requesting, receiving and handling of UE capability information at the base station 5; and / or the like. The communications control module 1363 includes a cell DRX / DTX configuration 1365 which the base station transmits to UEs it is serving and is used by the base station 5 to define the cell DRX / DTX inactive and active periods for one or more DTX / DRX patterns. The communications control module 1363 also includes the various timers 1368 used to define the timings discussed above.

[0114] Modifications and Alternatives 　　As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above examples whilst still benefiting from the advantages that they provide.

[0115] It will be appreciated, that whilst cellular communication generation (2G, 3G, 4G, 5G, 6G etc.) specific terminology may be used, in the interests of clarity, to refer to specific communication entities, the technical features described for a given entity are not limited to devices of that specific communication generation. The technical features may be implemented in any functionally equivalent communication entity regardless of any differences in the terminology used to refer to them.

[0116] In the above description, the UEs and the base station are described for ease of understanding as having a number of discrete functional components or modules. Whilst these modules may be provided in this way for certain applications, for example where an existing system has been modified to implement a corresponding device, in other applications, for example in systems designed with the inventive features in mind from the outset, these modules may be built into the overall operating system or code and so these modules may not be discernible as discrete entities.

[0117] In the above examples, a number of software modules were described. As those skilled in the art will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied as a signal over a computer network, or on a recording medium. Further, the functionality performed by part, or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred as it facilitates the updating of the base station or the UE in order to update their functionalities.

[0118] Each controller may comprise any suitable form of processing circuitry including (but not limited to), for example: one or more hardware implemented computer processors; microprocessors; central processing units (CPUs); arithmetic logic units (ALUs); input / output (IO) circuits; internal memories / caches (program and / or data); processing registers; communication buses (e.g., control, data and / or address buses); direct memory access (DMA) functions; hardware or software implemented counters, pointers and / or timers; and / or the like. Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0119] The base station may comprise a 'distributed' base station having a central unit 'CU' and one or more separate distributed units (DUs).

[0120] The User Equipment (or "UE", "mobile station", "mobile device" or "wireless device") in the present disclosure is an entity connected to a network via a wireless interface.

[0121] It should be noted that the present disclosure is not limited to a dedicated communication device and can be applied to any device having a communication function as explained in the following paragraphs.

[0122] The terms "User Equipment" or "UE" (as the term is used by 3GPP), "mobile station", "mobile device", and "wireless device" are generally intended to be synonymous with one another, and include standalone mobile stations, such as terminals, cell phones, smart phones, tablets, cellular IoT devices, IoT devices, and machinery. It will be appreciated that the terms "mobile station" and "mobile device" also encompass devices that remain stationary for a long period of time.

[0123] A UE may, for example, be an item of equipment for production or manufacture and / or an item of energy related machinery (for example equipment or machinery such as: boilers; engines; turbines; solar panels; wind turbines; hydroelectric generators; thermal power generators; nuclear electricity generators; batteries; nuclear systems and / or associated equipment; heavy electrical machinery; pumps including vacuum pumps; compressors; fans; blowers; oil hydraulic equipment; pneumatic equipment; metal working machinery; manipulators; robots and / or their application systems; tools; molds or dies; rolls; conveying equipment; elevating equipment; materials handling equipment; textile machinery; sewing machines; printing and / or related machinery; paper converting machinery; chemical machinery; mining and / or construction machinery and / or related equipment; machinery and / or implements for agriculture, forestry and / or fisheries; safety and / or environment preservation equipment; tractors; precision bearings; chains; gears; power transmission equipment; lubricating equipment; valves; pipe fittings; and / or application systems for any of the previously mentioned equipment or machinery etc.).

[0124] A UE may, for example, be an item of transport equipment (for example transport equipment such as: rolling stocks; motor vehicles; motorcycles; bicycles; trains; buses; carts; rickshaws; ships and other watercraft; aircraft; rockets; satellites; drones; balloons etc.). A UE may, for example, be an item of information and communication equipment (for example information and communication equipment such as: electronic computer and related equipment; communication and related equipment; electronic components etc.).

[0125] A UE may, for example, be a refrigerating machine, a refrigerating machine applied product, an item of trade and / or service industry equipment, a vending machine, an automatic service machine, an office machine or equipment, a consumer electronic and electronic appliance (for example a consumer electronic appliance such as: audio equipment; video equipment; a loud speaker; a radio; a television; a microwave oven; a rice cooker; a coffee machine; a dishwasher; a washing machine; a dryer; an electronic fan or related appliance; a cleaner etc.).

[0126] A UE may, for example, be an electrical application system or equipment (for example an electrical application system or equipment such as: an x-ray system; a particle accelerator; radio isotope equipment; sonic equipment; electromagnetic application equipment; electronic power application equipment etc.).

[0127] A UE may, for example, be an electronic lamp, a luminaire, a measuring instrument, an analyser, a tester, or a surveying or sensing instrument (for example a surveying or sensing instrument such as: a smoke alarm; a human alarm sensor; a motion sensor; a wireless tag etc.), a watch or clock, a laboratory instrument, optical apparatus, medical equipment and / or system, a weapon, an item of cutlery, a hand tool, or the like.

[0128] A UE may, for example, be a wireless-equipped personal digital assistant or related equipment (such as a wireless card or module designed for attachment to or for insertion into another electronic device (for example a personal computer, electrical measuring machine)).

[0129] A UE may be a device or a part of a system that provides applications, services, and solutions described below, as to "internet of things (IoT)", using a variety of wired and / or wireless communication technologies.

[0130] Internet of Things devices (or "things") may be equipped with appropriate electronics, software, sensors, network connectivity, and / or the like, which enable these devices to collect and exchange data with each other and with other communication devices. IoT devices may comprise automated equipment that follow software instructions stored in an internal memory. IoT devices may operate without requiring human supervision or interaction. IoT devices might also remain stationary and / or inactive for a long period of time. IoT devices may be implemented as a part of a (generally) stationary apparatus. IoT devices may also be embedded in non-stationary apparatus (e.g., vehicles) or attached to animals or persons to be monitored / tracked.

[0131] It will be appreciated that IoT technology can be implemented on any communication devices that can connect to a communications network for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory.

[0132] It will be appreciated that IoT devices are sometimes also referred to as Machine-Type Communication (MTC) devices or Machine-to-Machine (M2M) communication devices. It will be appreciated that a UE may support one or more IoT or MTC applications. Some examples of MTC applications are listed in the following table. This list is not exhaustive and is intended to be indicative of some examples of machine type communication applications.

[0133] Applications, services, and solutions may be an MVNO (Mobile Virtual Network Operator) service, an emergency radio communication system, a PBX (Private Branch eXchange) system, a PHS / Digital Cordless Telecommunications system, a POS (Point of sale) system, an advertise calling system, an MBMS (Multimedia Broadcast and Multicast Service), a V2X (Vehicle to Everything) system, a train radio system, a location related service, a Disaster / Emergency Wireless Communication Service, a community service, a video streaming service, a femto cell application service, a VoLTE (Voice over LTE) service, a charging service, a radio on demand service, a roaming service, an activity monitoring service, a telecom carrier / communication NW selection service, a functional restriction service, a PoC (Proof of Concept) service, a personal information management service, an ad-hoc network / DTN (Delay Tolerant Networking) service, etc.

[0134] Further, the above-described UE categories are merely examples of applications of the technical ideas and examples described in the present document. Needless to say, these technical ideas and examples are not limited to the above-described UE and various modifications can be made thereto.

[0135] Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0136] While the present disclosure has been particularly shown and described with reference to example embodiments thereof, the present disclosure is not limited to these example embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the claims. And each example embodiment can be appropriately combined with at least one of example embodiments.

[0137] Each of the drawings or figures is merely an example to illustrate one or more example embodiments. Each figure may not be associated with only one particular example embodiment, but may be associated with one or more other example embodiments. As those of ordinary skill in the art will understand, various features or steps described with reference to any one of the figures can be combined with features or steps illustrated in one or more other figures, for example, to produce example embodiments that are not explicitly illustrated or described. Not all of the features or steps illustrated in any one of the figures to describe an example embodiment are necessarily essential, and some features or steps may be omitted. The order of the steps described in any of the figures may be changed as appropriate.

[0138] The whole or part of the example embodiments disclosed above can be described as, but not limited to, the following supplementary notes. 　　(Supplementary Note 1) 　　A method performed by a user equipment, UE, the method comprising: 　　receiving, from an access network node, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not; and 　　configuring the UE with the cell DTX configuration and / or cell DRX configuration, based on the first information and the second information. 　　(Supplementary Note 2) 　　The method according to supplementary note 1, wherein 　　the first information includes at least one of: 　　　　information for a on-duration timer for the cell DTX configuration and / or cell DRX configuration, 　　　　information for a periodicity of a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, 　　　　information for a start offset for the cell DTX cycle and / or the cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, or 　　　　information for a slot offset for the cell DTX cycle and / or the cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration. 　　(Supplementary Note 3) 　　The method according to supplementary note 1 or 2, further comprising: 　　receiving, from the access network node, downlink control information, DCI, including third information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, and wherein 　　the third information has a different number of bits depending on whether the third information indicates to both the cell DTX configuration and the cell DRX configuration commonly, or to the cell DTX configuration and the cell DRX configuration independently. 　　(Supplementary Note 4) 　　The method according to supplementary note 3, wherein 　　in a case where the third information indicates to the cell DTX configuration and the cell DRX configuration independently, the third information has at least one respective bit for the cell DTX configuration and the cell DRX configuration independently, and 　　in a case where the third information indicates to both the cell DTX configuration and the cell DRX configuration commonly, the third information has at least one common bit for both the cell DTX configuration and the cell DRX configuration. 　　(Supplementary Note 5) 　　The method according to supplementary note 3 or 4, wherein 　　the RRC message includes fourth information for indicating a position of a block in the DCI for the UE, and 　　the third information is included in the block in the DCI. 　　(Supplementary Note 6) 　　The method according to supplementary note 4, wherein 　　the fourth information which is included in the RRC message is per cell operated by the access network node. 　　(Supplementary Note 7) 　　The method according to any one of supplementary notes 3 to 6, wherein 　　the DCI includes fifth information for indicating a physical uplink control channel, PUCCH, resource for high priority uplink transmission during a non-active period of a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration. 　　(Supplementary Note 8) 　　The method according to supplementary note 7, wherein 　　the PUCCH resource is allocated: 　　　　per cell operated by the access network node, or 　　　　to at least one cell operated by the access network node commonly. 　　(Supplementary Note 9) 　　The method according to supplementary note 7 or 8, wherein 　　the high priority uplink transmission includes at least one of: 　　　　transmission for a scheduling request, or 　　　　transmission for a hybrid automatic repeat request, HARQ, acknowledgment, ACK / negative ACK, NACK. 　　(Supplementary Note 10) 　　The method according to any one of supplementary notes 7 to 9, wherein 　　the PUCCH resource is used for PUCCH switching. 　　(Supplementary Note 11) 　　The method according to any one of supplementary notes 3 to 10, wherein 　　the DCI includes sixth information indicating at least one control resource set and / or at least one common search space for monitoring a physical downlink control channel, PDCCH, during a non-active period of a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration. 　　(Supplementary Note 12) 　　The method according to supplementary note 11, wherein 　　the at least one control resource set and / or the at least one common search space is defined: 　　　　per cell operated by the access network node, or 　　　　for at least one cell operated by the access network node commonly. 　　(Supplementary Note 13) 　　The method according to any one of supplementary notes 3 to 12, wherein 　　the DCI includes seventh information indicating whether the UE should skip monitoring of a physical uplink control channel, PUCCH. 　　(Supplementary Note 14) 　　The method according to any one of supplementary notes 1 to 13, wherein 　　the first information includes information for a validity timer for the cell DTX configuration and / or the cell DRX configuration. 　　(Supplementary Note 15) 　　The method according to any one of supplementary notes 1 to 14, further comprising: 　　transmitting, to the access network node, UE capability information includes eighth information indicating whether the UE supports the cell DTX configuration and / or the cell DRX configuration. 　　(Supplementary Note 16) 　　The method according to supplementary note 15, wherein 　　the eighth information includes at least one of: 　　　　information indicating whether the UE supports a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, 　　　　information indicating whether the UE supports a short cell DTX cycle and / or a short cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, or 　　　　information indicating whether the UE supports cell DTX / DRX command Media Access Control, MAC, Control Element, CE. 　　(Supplementary Note 17) 　　The method according to any one of supplementary notes 1 to 16, further comprising: 　　in a case where the UE does not receive downlink control information, DCI, including third information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, performing a fall back operation for cell DTX / DRX operation. 　　(Supplementary Note 18) 　　The method according to supplementary note 17, wherein 　　the fall back operation includes: 　　　　receiving, from the access network node, a physical downlink control channel, PDCCH; and 　　　　transmitting a scheduling request indicating falling back for cell DTX / DRX. 　　(Supplementary Note 19) 　　The method according to supplementary note 18, wherein 　　the scheduling request is transmitted using at least one of: 　　　　a physical uplink control channel for fall back operation for cell DTX / DRX, or 　　　　a configured grant. 　　(Supplementary Note 20) 　　The method according to supplementary note 17, wherein 　　the fall back operation includes starting a fallback timer for cell DTX / DRX to deactivate the cell DTX / DRX. 　　(Supplementary Note 21) 　　The method according to supplementary note 17, wherein 　　the fall back operation includes: 　　　　monitoring a search space for fallback for the cell DTX / DRX; and 　　　　receiving fallback downlink control information for fallback for the cell DTX / DRX using the search space, and 　　the fallback downlink control information includes nineth information indicating whether the cell DTX configuration and / or the cell DRX configuration should be activated or deactivated. 　　(Supplementary Note 22) 　　A method performed by an access network node, the method comprising: 　　transmitting, to a user equipment, UE, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, wherein 　　the first information and the second information is used by the UE to configure the UE with the cell DTX configuration and / or cell DRX configuration. 　　(Supplementary Note 23) 　　A user equipment, UE, comprising: 　　means for receiving, from an access network node, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not; and 　　means for configuring the UE with the cell DTX configuration and / or cell DRX configuration, based on the first information and the second information. 　　(Supplementary Note 24) 　　An access network node comprising: 　　means for transmitting, to a user equipment, UE, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, wherein 　　the first information and the second information is used by the UE to configure the UE with the cell DTX configuration and / or cell DRX configuration.

[0139] This application is based upon and claims the benefit of priority from Great Britain Patent Application No. 2310797.2, filed on July 13, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0140] 1 mobile ('cellular' or 'wireless') communication system 3 user equipment 5 radio access network (RAN) node 7 core network 9 cell 10 control plane function (CPF) 10-1 Access and Mobility Management Function (AMF) 10-2 Session Management Function (SMF) 11 user plane function (UPF) 20 external data network 1231 transceiver circuit 1233 antenna 1235 user interface 1237 controller 1239 memory 1241 operating system 1243 communications control module 1245 cell DRX / DTX configuration 1246 UE capability information 1248 timers 1351 transceiver circuit 1353 antenna 1355 core network interface 1357 controller 1359 memory 1361 operating system 1363 communications control module 1365 cell DRX / DTX configuration 1368 timers

Claims

1. A method performed by a user equipment, UE, the method comprising: 　　receiving, from an access network node, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not; and 　　configuring the UE with the cell DTX configuration and / or cell DRX configuration, based on the first information and the second information.

2. The method according to claim 1, wherein 　　the first information includes at least one of: 　　　　information for a on-duration timer for the cell DTX configuration and / or cell DRX configuration, 　　　　information for a periodicity of a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, 　　　　information for a start offset for the cell DTX cycle and / or the cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, or 　　　　information for a slot offset for the cell DTX cycle and / or the cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration.

3. The method according to claim 1 or 2, further comprising: 　　receiving, from the access network node, downlink control information, DCI, including third information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, and wherein 　　the third information has a different number of bits depending on whether the third information indicates to both the cell DTX configuration and the cell DRX configuration commonly, or to the cell DTX configuration and the cell DRX configuration independently.

4. The method according to claim 3, wherein 　　in a case where the third information indicates to the cell DTX configuration and the cell DRX configuration independently, the third information has at least one respective bit for the cell DTX configuration and the cell DRX configuration independently, and 　　in a case where the third information indicates to both the cell DTX configuration and the cell DRX configuration commonly, the third information has at least one common bit for both the cell DTX configuration and the cell DRX configuration.

5. The method according to claim 3 or 4, wherein 　　the RRC message includes fourth information for indicating a position of a block in the DCI for the UE, and 　　the third information is included in the block in the DCI.

6. The method according to claim 4, wherein 　　the fourth information which is included in the RRC message is per cell operated by the access network node.

7. The method according to any one of claims 3 to 6, wherein 　　the DCI includes fifth information for indicating a physical uplink control channel, PUCCH, resource for high priority uplink transmission during a non-active period of a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration.

8. The method according to claim 7, wherein 　　the PUCCH resource is allocated: 　　　　per cell operated by the access network node, or 　　　　to at least one cell operated by the access network node commonly.

9. The method according to claim 7 or 8, wherein 　　the high priority uplink transmission includes at least one of: 　　　　transmission for a scheduling request, or 　　　　transmission for a hybrid automatic repeat request, HARQ, acknowledgment, ACK / negative ACK, NACK.

10. The method according to any one of claims 7 to 9, wherein 　　the PUCCH resource is used for PUCCH switching.

11. The method according to any one of claims 3 to 10, wherein 　　the DCI includes sixth information indicating at least one control resource set and / or at least one common search space for monitoring a physical downlink control channel, PDCCH, during a non-active period of a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration.

12. The method according to claim 11, wherein 　　the at least one control resource set and / or the at least one common search space is defined: 　　　　per cell operated by the access network node, or 　　　　for at least one cell operated by the access network node commonly.

13. The method according to any one of claims 3 to 12, wherein 　　the DCI includes seventh information indicating whether the UE should skip monitoring of a physical uplink control channel, PUCCH.

14. The method according to any one of claims 1 to 13, wherein 　　the first information includes information for a validity timer for the cell DTX configuration and / or the cell DRX configuration.

15. The method according to any one of claims 1 to 14, further comprising: 　　transmitting, to the access network node, UE capability information includes eighth information indicating whether the UE supports the cell DTX configuration and / or the cell DRX configuration.

16. The method according to claim 15, wherein 　　the eighth information includes at least one of: 　　　　information indicating whether the UE supports a cell DTX cycle and / or a cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, 　　　　information indicating whether the UE supports a short cell DTX cycle and / or a short cell DRX cycle regarding the cell DTX configuration and / or cell DRX configuration, or 　　　　information indicating whether the UE supports cell DTX / DRX command Media Access Control, MAC, Control Element, CE.

17. The method according to any one of claims 1 to 16, further comprising: 　　in a case where the UE does not receive downlink control information, DCI, including third information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, performing a fall back operation for cell DTX / DRX operation.

18. The method according to claim 17, wherein 　　the fall back operation includes: 　　　　receiving, from the access network node, a physical downlink control channel, PDCCH; and 　　　　transmitting a scheduling request indicating falling back for cell DTX / DRX.

19. The method according to claim 18, wherein 　　the scheduling request is transmitted using at least one of: 　　　　a physical uplink control channel for fall back operation for cell DTX / DRX, or 　　　　a configured grant.

20. The method according to claim 17, wherein 　　the fall back operation includes starting a fallback timer for cell DTX / DRX to deactivate the cell DTX / DRX.

21. The method according to claim 17, wherein 　　the fall back operation includes: 　　　　monitoring a search space for fallback for the cell DTX / DRX; and 　　　　receiving fallback downlink control information for fallback for the cell DTX / DRX using the search space, and 　　the fallback downlink control information includes nineth information indicating whether the cell DTX configuration and / or the cell DRX configuration should be activated or deactivated.

22. A method performed by an access network node, the method comprising: 　　transmitting, to a user equipment, UE, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, wherein 　　the first information and the second information is used by the UE to configure the UE with the cell DTX configuration and / or cell DRX configuration.

23. A user equipment, UE, comprising: 　　means for receiving, from an access network node, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not; and 　　means for configuring the UE with the cell DTX configuration and / or cell DRX configuration, based on the first information and the second information.

24. An access network node comprising: 　　means for transmitting, to a user equipment, UE, a Radio Resource Control, RRC, message including first information for configuring the UE with cell discontinuous transmission, DTX, configuration and / or cell discontinuous reception, DRX, configuration, for at least one cell operated by the access network node and second information for indicating whether the cell DTX configuration and / or the cell DRX configuration shall be activated or not, wherein 　　the first information and the second information is used by the UE to configure the UE with the cell DTX configuration and / or cell DRX configuration.

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