GB2626994A - Communication system - Google Patents
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- GB2626994A GB2626994A GB2301961.5A GB202301961A GB2626994A GB 2626994 A GB2626994 A GB 2626994A GB 202301961 A GB202301961 A GB 202301961A GB 2626994 A GB2626994 A GB 2626994A
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Classifications
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- H—ELECTRICITY
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- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0212—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
- H04W52/0216—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave using a pre-established activity schedule, e.g. traffic indication frame
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/20—Manipulation of established connections
- H04W76/28—Discontinuous transmission [DTX]; Discontinuous reception [DRX]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0203—Power saving arrangements in the radio access network or backbone network of wireless communication networks
- H04W52/0206—Power saving arrangements in the radio access network or backbone network of wireless communication networks in access points, e.g. base stations
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
A method at an access network node comprises determining a location of synchronisation signals to be transmitted within a frame (e.g. SSB); determining a cell discontinuous reception or discontinuous transmission (cell DRX/DTX) configuration based on the location of the synchronisation signals; signalling information to a user equipment (UE) to allow the UE to determine the location of the synchronisation signals and the cell DRX/DTX configuration. A further method comprises determining ON/OFF durations of a cell DRX/DTX configuration; determining, from the ON/OFF durations and a minimum granularity of the ON/OFF durations, a multiplication factor that can be used to determine the ON/OFF durations from the minimum granularity; signalling the minimum granularity to the UE. A further method comprises transmitting information to a UE indicating a cell DRX/DTX with ON/OFF durations; wherein the UE is configured with its own UE DRX/DTX configuration with its own ON/OFF durations; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration. A further method comprises obtaining information indicating a DRX/DTX configuration defining ON/OFF durations; transmitting an activation signal indicating to the UE activation of the cell DRX/DTX configuration to cause the UE to suppress uplink transmissions during the cell OFF durations including dynamic UL transmission. Also provided are corresponding methods at a UE and corresponding apparatuses for executing the methods.
Description
Communication System The present invention relates to a communication system. The invention 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 invention has particular, although not necessarily exclusive, relevance to discontinuous reception (DRX) and discontinuous transmission (DTX) to reduce energy consumption.
Recent developments of the 3GPP standards are 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'. In addition, the term '5G' and 'new radio' (NR) 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, the NGMN 5G White Paper' V1.0 by the Next Generation Mobile Networks (NGMN) Alliance, which document is available from https://www.ngmn.org/5g-white-paper.html. 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.
Under the 3GPP standards, a NodeB (or an eNB in LTE, 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 equipment or UE') connect to a core network and communicate with other communication devices or remote servers. For simplicity, the present application will use the term RAN node or base station to refer to any such access nodes.
There is a need for improved 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.
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 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).
Many proposals have been made for UE DTX/DRX operation and attention is turning now to such discontinuous operation of the base station cell(s) -which is referred to as "cell DTX/DRX". With cell DTX/DRX, the cell (RAN node) stops transmitting and receiving 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). The cell's operation also has to cater for use with UEs that have been configured for UE DTX/DRX themselves to ensure that efficient communication is maintained between the base station and the UEs when both are using DTX/DRX techniques to reduce energy consumption. More generally, there is a need for more efficient and reliable methods and apparatus for increasing the energy efficiency of wireless communication systems.
The invention aims to provide apparatus and methods that at least partially address one or more of the above needs and/or issues.
Summary of Invention
According to one aspect, the invention provides a method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: determining a location of synchronization signals to be transmitted by the access network node within a frame; determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals; and signalling information to the UE to allow the UE to determine the location of the synchronization signals and the cell DTX/DRX configuration.
The cell DTX/DRX configuration typically defines a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE and wherein the cell ON duration is around the location of the synchronization signals within the frame. The cell ON duration may extend over a period of time in which the synchronization signals are transmitted by the access network node.
In some embodiments, the synchronization signals are transmitted in bursts in a periodic manner and the cell OFF duration is configured in a gap between adjacent bursts. In this case, the cell DTX/DRX configuration may define one or more cell ON durations in the gap between adjacent bursts. The synchronization signal bursts may be transmitted in a periodic manner and one or more parameters relating to the cell DTX/DRX configuration may be mapped to characteristics of the periodic bursts of synchronization signals using predefined mapping data. The mapping data may take the form of a look up table. The one or more parameters relating to the cell DTX/DRX configuration may be either preconfigured parameter values or are configured by a network node.
The one or more parameters may comprise one or more parameters selected from the group of: i) a parameter relating to a starting position for the cell ON duration; ii) a parameter relating to a starting position for the cell OFF duration; iii) a parameter relating to a number of DTX/DRX cycles to be performed; iv) a parameter relating to a periodicity of the DTX/DRX cycles.
The cell DTX/DRX configuration may include a cell DTX/DRX pattern that defines the ON duration and the OFF duration and periodicity information indicating a DRX cycle interval at which the DTX/DRX pattern repeats and/or information indicating a number of times the DTX/DRX pattern is to be repeated. One cell DTX/DRX pattern may be defined and the mapping data relates the synchronization signal burst periodicity to the number of DTX/DRX cycles within the synchronization signal burst periodicity.
The mapping may be a one to one mapping between parameters that define the synchronization signal transmissions and the cell DTX/DRX configuration. Alternatively, the mapping may be a one to many mapping between parameters that define the synchronization signal transmissions and the cell DTX/DRX configuration.
In a case where the synchronization signal burst periodicity increases, the mapping data maps to more cell DTX/DRX configurations and in a case where the synchronization signal burst periodicity decreases, the mapping data maps to fewer cell DTX/DRX configurations.
A minimum granularity of the ON duration and/or the OFF duration may be defined and the mapping data may relate a parameter of the synchronization signal transmissions to one or more multiplication factors that can be used determine the cell ON duration and the cell OFF duration using the minimum granularity. In the case where the mapping data relates the parameter of the synchronization signal transmissions to a plurality of multiplication factors, the method may further comprise transmitting signalling information to allow the UE to identify which of the plurality of multiplication factors are to be used to determine the cell ON duration and/or the cell OFF duration.
The invention also provides a method performed by a user equipment, UE, that is configured to communicate with an access network node, the method comprising: receiving signalling information from the access network node; determining a location of synchronization signals to be transmitted by the access network node within a frame, using the signalling information; and determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals.
The invention also provides an access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for determining a location of synchronization signals to be transmitted by the access network node within a frame; means for determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals; and means for signalling information to the UE to allow the UE to determine the location of the synchronization signals and the cell DTX/DRX configuration.
The invention also provides a user equipment, UE, that is configured to communicate with an access network node, the UE comprising: means for receiving signalling information from the access network node; means for determining a location of synchronization signals to be transmitted by the access network node within a frame, using the signalling information; and means for determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals. The UE can use the cell DTX/DRX information to control its own behaviour.
The invention also provides a method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node, the cell DTX/DRX configuration defining an ON duration in which the access network node is active and configured to communicate with the UE and an OFF duration in which the access network node is inactive and configured not to communicate with the UE; determining from the ON duration and/or the OFF duration and a minimum granularity of the ON duration and/or the OFF duration, at least one multiplication factor that can be used to determine the ON duration and/or the OFF duration of the cell DTX/DRX configuration from the minimum granularity; and signalling to the UE information indicating one or more of: i) the minimum granularity; ii) the at least one multiplication factor; iii) a parameter relating to a starting position for the cell ON duration; iv) a parameter relating to a number of cell DTX/DRX cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles.
The minimum granularity may be either fixed or is signalled to the UE. One or more of the at least one multiplication factor and the number of cell DTX/DRX cycles may be implicitly and/or explicitly indicated to the UE. In one embodiment, the at least one multiplication factor is signalled to the UE in a cell specific manner, in a group specific manner or in a UE specific manner.
The method may further comprise signalling resources for uplink and/or downlink signals and/or channels to the UE and wherein one or more parameters relating to the determined cell DTX/DRX configuration that are not transmitted to the UE depend on the signalled resources. The signalled resources may be related to a location of the ON duration, a location of the OFF duration and/or the at least one multiplication factor.
The access network node may also transmit an activation signal indicating when the cell DTX/DRX configuration is activated and/or the cell DTX/DRX cycles may repeat until the access network node transmits a deactivation signal.
The invention also provides a method performed by a user equipment, UE, that is configured to communicate with access network node, the method comprising: receiving signalling information from the access network node indicating one or more of: i) the minimum granularity; ii) at least one multiplication factor; iii) a parameter relating to a starting position for a cell ON duration; iv) a parameter relating to a number of cell discontinuous transmission/discontinuous reception, DTX/DRX, cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles; obtaining a minimum granularity of at least one of a cell ON duration and/or a cell OFF duration; determining at least one multiplication factor from the signalling information; and using the minimum granularity and the determined at least one multiplication factor to determine a cell DTX/DRX configuration for the access network node using the signalling information, the cell DTX/DRX configuration defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE.
The minimum granularity may be a fixed value and may be obtained from memory or it may be a system variable and the received signalling information indicates implicitly or explicitly the minimum granularity to the UE.
The received signalling information will typically indicate implicitly or explicitly one or more of: the at least one multiplication factor and the number of cell DTX/DRX cycles to the UE. For example, the at least one multiplication factor is signalled to the UE in a cell specific manner, in a group specific manner or in a UE specific manner.
The method may further comprise receiving second signalling information that indicates resources for uplink and/or downlink signals and/or channels to the UE and wherein the UE determines one or more parameters relating to the cell DTX/DRX configuration using the second signalling information. The UE may be configured to determine a location (timing) of the ON duration, a location of the OFF duration and/or the at least one multiplication factor based on the resources indicated by the second signalling information.
The UE may also receive an activation signal from the access network node indicating when the cell DTX/DRX configuration is activated. In some embodiments, the UE also determines that the DTX/DRX cycle repeats until a cell DTX/DRX deactivation signal is received from the access network node.
The invention also provides an access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node, the cell DTX/DRX configuration defining an ON duration in which the access network node is active and configured to communicate with the UE and an OFF duration in which the access network node is inactive and configured not to communicate with the UE; means for determining from the ON duration and/or the OFF duration and a minimum granularity of the ON duration and/or the OFF duration, at least one multiplication factor that can be used to determine the ON duration and/or the OFF duration of the cell DTX/DRX configuration from the minimum granularity; and means for signalling to the UE information indicating one or more of: i) the minimum granularity; ii) the at least one multiplication factor; iii) a parameter relating to a starting position for the cell ON duration; iv) a parameter relating to a number of cell DTX/DRX cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles. 30 The invention also provides a user equipment, UE, that is configured to communicate with access network node, the UE comprising: means for receiving signalling information from the access network node indicating one or more of: i) the minimum granularity; fi) at least one multiplication factor; iii) a parameter relating to a starting position for a cell ON duration; iv) a parameter relating to a number of cell discontinuous transmission/discontinuous reception, DTX/DRX, cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles; means for obtaining a minimum granularity of at least one of a cell ON duration and/or a cell OFF duration; means for determining at least one multiplication factor from the signalling information; and means for using the minimum granularity and the determined at least one multiplication factor to determine a cell DTX/DRX configuration for the access network node using the signalling information, the cell DTX/DRX configuration defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE.
The invention also provides a method performed by a user equipment, UE, that is configured to communicate with an access network node of a network, the method comprising: obtaining a UE discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; receiving information from the access network node indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
The UE may receive the cell DTX/DRX configuration and parameters via cell specific signalling, group common signalling, UE specific signalling or a combination thereof. 30 The method may further comprise receiving an activation signal from the access network node indicating when the cell DTX/DRX configuration is activated. The UE may determine the start position for cell DTX/DRX based on the timing of when the activation signal is received or based on other signalling information received from the access network node. The activation signal may indicate if the cell DTX/DRX over-rides any UE DRX configuration. If the activation signal indicates that cell DTX/DRX does not over-ride the UE DRX configuration then the UE may control its operation in accordance with one or more of the following: i) the cell DTX/DRX overrides the UE behaviour on UE DRX if the UE DRX cycle(s) fall completely within an OFF duration of the cell DTX/DRX configuration; ii) in a case where the UE DRX cycle overlaps with a cell DTX cycle such that the UE's OFF duration overlaps with the cell's ON duration and the cell's OFF duration, the UE remains inactive for its entire OFF duration; and iii) in a case where the UE DRX cycle overlaps with a cell DTX cycle such that the UE's ON duration overlaps with the cell's ON duration and the cell's OFF duration, the UE remains active only for the duration when the UE's and the cell's ON durations overlap; and iv) the UE only transmits signals to the access network node during ON durations of the cell DTX/DRX configuration.
The method may further comprise determining that the DTX/DRX cycle repeats until a cell DTX/DRX deactivation signal is received from the access network node.
The invention also provides a method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: transmitting information to the UE indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein the UE is configured to operate in a discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
The invention also provides a user equipment, UE, that is configured to communicate with an access network node of a network, the UE comprising: means for obtaining a UE discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; and means for receiving information from the access network node indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
The invention also provides an access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for transmitting information to the UE indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein the UE is configured to operate in a discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
The invention also provides a method performed by a user equipment, UE, that is configured to communicate with an access network node of a network, the method comprising: obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; receiving an activation signal indicating activation of the cell DTX/DRX configuration at the access network node; and suppressing uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
The dynamic UL transmissions may include one or more Scheduling Requests, SRs, that request UL resources for the UE to transmit UL data.
In some embodiments, suppressing uplink transmissions does not include suppressing UL transmissions based on preconfigured periodic UL transmission resources.
The method may include extending the ON duration after the cell DTX/DRX configuration has been activated to allow for ongoing or pending Hybrid Automatic Repeat Request, HARQ, transmissions or retransmissions before switching to the inactive mode. During the extended ON duration, new HARQ transmissions may not be initiated.
In some embodiments, the ON duration may be extended until the ongoing or pending HARQ transmissions have been completed or for a predetermined time. During the extended period of the ON duration the UE may only transmits HARQ retransmissions.
The UE may receive an HARQ early termination signal from the access network node prior to the cell entering into an OFF duration in which case the UE will terminate any HARQ transmissions or retransmissions and may flush its transmission buffer of a current Transport Block, TB, if the UE cannot decode the TB based on available TBs.
Alternatively, the method may delaying the transmission or retransmission of a pending HARQs until the next cell ON duration.
The invention also provides a method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; and transmitting an activation signal indicating to the UE activation of the cell DTX/DRX configuration at the access network node to cause the UE to suppress uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
The invention also provides a user equipment, UE, that is configured to communicate with an access network node of a network, the UE comprising: means for obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; means for receiving an activation signal indicating activation of the cell DTX/DRX configuration at the access network node; and means for suppressing uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
The invention also provides an access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; and means for transmitting an activation signal indicating to the UE activation of the cell DTX/DRX configuration at the access network node to cause the UE to suppress uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
The invention also provides computer implementable instructions for causing a programmable computer device to perform any of the above methods. The instructions may be provided on a signal or on a tangible computer readable medium.
Embodiments of the invention 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') telecommunication 25 system; Fig. 2 illustrates a typical frame structure that may be used in the telecommunication system of Fig. 1; Fig. 3 illustrates an SSB transmission; Fig. 4 illustrates an SS burst set that comprises a number of SSB transmissions; Fig. 5 illustrates the way in which SSBs within an SS burst set are mapped to beams transmitted by a base station; Fig. 6 illustrates an example of a DRX cycle or pattern; Fig. 7a illustrates an SS burst transmissions and a first exemplary cell DTX/DRX pattern that may be determined from the SS burst configuration; Fig. 7b illustrates an SS burst transmissions and a second exemplary cell DTX/DRX pattern that may be determined from the SS burst configuration; Fig. 8a is a flow chart illustrating the operation of a base station in accordance with a first proposal; Fig. 8a is a flow chart illustrating the operation of a UE in accordance with the first proposal; Fig. 9a is a flow chart illustrating the operation of a base station in accordance with a second proposal; Fig. 9b is a flow chart illustrating the operation of a UE in accordance with the second proposal; Fig. 10 is a flow chart illustrating the operation of a UE in accordance with a third proposal; Fig. 11a is a flow chart illustrating the operation of a UE in handling HARQ transmissions; Fig. llb is a flow chart illustrating the operation of a base station in in handling HARQ transmissions; Fig. 12 is a schematic block diagram illustrating the main components of a UE for the telecommunication system of Fig. 1; and Fig. 13 is a schematic block diagram illustrating the main components of a base station for the telecommunication system of Fig. 1.
Overview An exemplary telecommunication system will now be described in general terms, by way of example only, with reference to Figs. 1 and 2.
Fig. 1 schematically illustrates a mobile (cellular' or 'wireless') telecommunication system 1 to which embodiments of the present invention are applicable.
In the 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 NR/5G base station or cgNB' 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 core network or evolved packet core network (EPC)).
As those skilled in the art will appreciate, whilst three UEs 3 and one base station 5 are shown in Fig. 5 for illustration purposes, the system, when implemented, will typically include other base stations 5 and UEs 3.
Each base station 5 controls the associated cell(s) 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 any other 3GPP or non-3GPP communication protocols.
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).
The core network 7 includes a number of logical nodes (or 'functions') for supporting communication in the telecommunication system 1. In this example, the core network 7 comprises control plane functions (CPFs) 10 and one or more user plane functions (UPFs) 11. The CPFs 10 include one or more Access and Mobility Management Functions (AMFs) 10-1, one or more Session Management Functions (SMFs) and a number of other functions 10-n.
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 logical non-access stratum (NAS) connection over an Ni 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.
The UPF(s) 11 are connected to an external data network 20 (e.g. an IP network such as the internet) via reference point N6 for communication of the user data.
The AMF 10-1 performs mobility management related functions, maintains the nonNAS signalling connection with each UE 3 and manages UE registration. The AMF 10- 1 is also responsible for managing paging. 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 also allocates IP addresses to each UE 3.
The base station 5 of the communication system 1 is configured to operate at least one cell 9 on an associated TDD carrier that operates in unpaired spectrum. It will be appreciated that the base station 5 may also operate at least one cell 9 on an associated FDD carrier that operates in paired spectrum.
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. The 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, UEspecific 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.
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).
The UE 3 may receive a Synchronization Signal Block (SSB), and the UE 3 may assume that reception occasions of a PBCH, primary synchronization signal (PSS) and secondary synchronization signal (SSS) are in consecutive symbols and form a SS/PBCH block. The base station 5 may transmit a number of synchronization signal (SS) blocks corresponding to different DL beams. The total number of SS blocks may be confined, for example, within a 5 ms duration as an SS burst. The periodicity of the SSB transmissions may be indicated to the UE using any suitable signalling (e.g. per serving cell using ssb-periodicityServingCell). The periodicity value for the SSB may be, for example, greater than or equal to 20 ms. For initial cell selection, the UE 3 may be configured to assume that an SS burst occurs with a periodicity of 2 frames. The UE 3 may also be provided with an indication of which SSBs within a 5 ms duration are transmitted (e.g. using ssb-PositionslnBurst).
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.
Frame Structure Referring to Fig. 2, which illustrates the typical frame structure that may be used in the telecommunication system 1, the base station 5 and UEs 3 of the telecommunication 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.
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, p, where p=0 represents 15 kHz (corresponding to the LTE SCS). Currently, the SCS for other values of p can, in effect, be derived from p=0 by scaling up in powers of 2 (i.e. SCS = 15 x 2P kHz). The relationship between the parameter, p, and SCS (Of) is as shown in Table 1: N Al = 2P.15[kHz] Number of slots Slot length (ms) per subframe 0 15 1 1 1 30 2 0.5 2 60 4 0.25 3 120 8 0.125 4 240 16 0.0625 Table 1 -5G Numerology System information and SIB It will be appreciated that transmissions in a cell 9 of a base station 5 may include one or more broadcast transmissions and one or more unicast transmissions for reception by a UE 3. System information (SI) transmitted in a cell may include 'minimum SI' (MSI) and 'other SI' (OSI). The OSI may be broadcast on-demand, for example using a downlink shared channel (DL-SCH). The OSI may be broadcast upon request from a UE 3 that is in a radio resource control (RRC) idle or RRC inactive state. The OSI may also be requested by a UE 3 that is in the RRC connected state, for example via one or more dedicated RRC transmissions.
The SI may include information for enabling (e.g. configuring) the UE 3 to complete a cell selection, may include information for enabling the UE 3 to complete a cell reselection procedure, or for enabling the UE 3 to receive one or more paging messages transmitted in a cell. SI may be broadcast using a Master Information Block (MIB) and one or more System Information Blocks (SIB).
The MSI comprises the MIB and system information block 1 (SIB1). The MIB includes information for use by a UE 3 to receive SIB1, for example a subcarrier spacing for SIB1. The MIB provides information corresponding to a Control Resource Set (CORESET) and Search Space. SIB1 may be referred to as 'remaining MSI' (RMSI).
SIB1 may be transmitted in a dedicated RRC message, and other SIB (e.g. SIB2 to SIB9) may be transmitted using one or more other suitable RRC transmissions. The MIB and SIB1 may provide the UE 3 with an indication of scheduling information for receiving and decoding the other SIB, such as SIB2 to SIB9, and may provide information for use by the UE 3 to receive one or more paging messages. The OSI may comprise, for example, SI B2 to SIB9 transmitted using a DL-SCH in SI messages. A mapping of SIB2 to SIB9 to corresponding SI messages may be provided to the UE 3 by the base station 5. MIB and SIB1 to SIB9 are described in more detail, for example, in 3GPP TS 38.331. For example, SIB2 provides information for intra- frequency, inter-frequency and inter-system cell reselection, SIB3 provides cell-specific information for intra-frequency cell reselection, and SIB4 provides information for inter-frequency cell reselection. SIB5 provides information regarding inter-system cell reselection towards 4G (LTE). SIB6 and SIB7 provide information for an earthquake and tsunami warning system (ETWS). SIB8 provides information for a commercial mobile alert service (CMAS) notification, for example to provide warning text messages to the UE 3. SIB9 includes information regarding coordinated universal time (UTC), global positioning system (GPS) time (e.g. for GPS initialisation) and local time.
SIB may be broadcast periodically (e.g. according to a predetermined periodic pattern), or alternatively may be provided 'on-demand', for example in response to a request from a UE 3. For example, MIB may be transmitted with a periodicity of 80 ms and repetitions made within 80 ms, and SIB1 may be transmitted with a periodicity of 160 ms and a variable transmission repetition periodicity within 160 ms (e.g. 20 ms). SIB1 can be used to indicate to a UE 3 which SIB are transmitted periodically and which SIB are available on-demand in response to a request from the UE 3. A UE 3 may be configured to request on-demand SIB using MSG1 (random access preamble (RA)), which may be referred to as a MSG1-based on-demand SI request, or MSG3 (RRC Connection Request), which may be referred to as a MSG3-based on-demand SI request. A physical broadcast channel (PBCH) can be used to broadcast the MIB.
SS Burst Set Transmissions The base station 5 normally transmits the PBCH with synchronisation signals (SS) (e.g. primary synchronisation signal (PSS) and secondary synchronisation signal (SSS)) in a SS/PBCH Block (SSB). Fig. 3 illustrates an exemplary SSB that is used in NR (other SSB configurations could of course be used). The SSB comprises four consecutive orthogonal frequency-division multiplexed (OFDM) symbols that are mapped to PSS, SSS and PBCH associated with a demodulation reference signal (DM-RS). In the frequency domain, an SS/PBCH block comprises 240 contiguous subcarriers (20 Resource Blocks, RBs). The PSS occupies the first OFDM symbol and spans over 127 subcarriers; and the SSS is located in the third OFDM symbol and spans over 127 subcarriers. There are 8 i.in-used subcarriers below the SSS and 9 un-used subcarriers above the SSS. The PBCH occupies two full OFDM symbols (the second and fourth) spanning 240 subcarriers and in the third OFDM symbol spanning 48 subcarriers below and above the SSS. This results in the PBCH occupying 576 subcarriers across three OFDM symbols. This SSB is periodically transmitted with a periodicity of 5ms, lOms, 20ins, 40ms, Burs or 160ms. A longer periodicity is better for network energy performance, whereas a shorter periodicity is better for faster cell search for UEs. The base station 5 typically defines the SSB periodicity that it will use via the ssb-PeriodicityServingCelt Information Element (1E). The default periodicity is 20ms.
NR base stations 5 are able to perform beam forming, whereby the base station operates a number of directional antennae within the cell 9 -which helps to increase the SNR for the individual UEs being served by the cell 9 and hence the traffic throughput for those UEs. To enable beam sweeping for PSS/SSS and PBCH, SS burst sets are defined. Each SSB burst comprises a set of SSBs, each SSB being for transmission on a respective beam. The SSBs in the burst set are transmitted in a time division multiplexed manner. Each SS burst is confined to be within the first half or the second half of a radio frame, which in the case of NR is within a 5ms window. Therefore, the maximum number of beams that can be transmitted by a base station 5 within the cell 9 is defined by the maximum number of SSBs that can be defined within an SS burst. NR defines that the maximum number of SSBs within a burst depends on the carrier frequency band as defined below in Table 2: Carrier Frequency Maximum Number of Candidate SSBs within SS Burst Set (Lmax) Fc s 3 GHz 4 3 GHz < Fc s 6 GHz 8 Fc > 6 GHz 64 Table 2 -Maximum number of SSBs in burst Within a Sms haft frame, the starting OFDM symbol index for a candidate SSB within an SS burst set depends upon the subcarrier spacing (SOS) and carrier frequency/band and is defined below in Table 2: Subcarrier spacing (SCS) OFDM starting symbol of the candidate SSB Fc 3 GHz Lmax = 4 3 GHz < Fc GHz 6 Fc > 6 GHz Lmax = 4 Lmax = 8 Case A: {2,8} + 14n n = 0,1 n = 0, 1, 2, 3 N/A kHz Case B: {4,8,16,20} + n = 0 n = 0, 1 N/A 28n kHz Case C: {2,8} + 14n n = 0, 1 n = 0, 1, 2, 3 N/A kHz Case D: {4,8,16,20} + N/A N/A n=0,1,2,3,5,6, 28n 7,8,10,11,12, kHz 13,15,16,17, Case E: {8,12,16,20,32 N/A N/A n=0,1,2,3,5,6, 36,40,44} + 7,8 240 kHz 56n Table 3-SSB Starting Symbol Index An example of the timing of candidate SSBs within an SS burst set 110 is illustrated in Fig. 4 for the case of SCS = 15 kHz and a carrier frequency between 3 GHz and 6 GHz. In this case the maximum number of SSBs in the burst set (Lmax) is 8 and the SSB starting symbol indexes are: 2, 8, 16, 22, 30, 36, 44 and 50. In Fig. 4, the periodicity of the SS bursts is set at the default 20ms duration.
The base station 5 typically transmits information about the SSBs that will be transmitted in an SS Burst Set (it is not necessary to transmit the maximum number Lmax) via SI B1 and in some cases in RRC signalling. The SSB information transmitted by the base station 5 typically includes: the value of n in Table 3, which defines the Timing Advance Offset information indicating which of the Lmax number of SSBs are active; and the periodicity of the SS burst set. The number of active SSBs in an SS burst defines an SSB pattern which is repeated periodically at the rate defined by the periodicity of the SS bursts. Fig. 5 illustrates one such pattern of SSBs that is transmitted (in this example SSB #1 to SSB #8) in an SS burst 110 are that are mapped onto a respective beam 120-1 to 120-8 that is transmitted by the base station 5.
UE DDUDRX
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.
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 (1E) 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.
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.
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 (CGPUSCH)). 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.
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 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.
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)).
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).
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.
Cell DTX/DRX Cell DTX/DRX can operate 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. If the base station 5 (cell) and the UEs 3 operate in a DTX/DRX mode together, then coordination is appropriate to avoid inefficient communication between them (to ensure that the UEs 3 are not trying to transmit data to or receive data from the base station 5 when the base station 5 is in the inactive state and vice versa). For example, as explained above, when a UE is operating a C-DRX mode, the UE 3 can transmit signals to the base station 5 even when it is in the DRX inactive mode. Accordingly, for efficient communication between the base station 5 and the UEs 3, the base station 5 should indicate its cell DTX/DRX configuration to the UEs 3 to allow them to modify their behaviour. The base station 5 could explicitly signal the parameters that are necessary to define the cell DTX/DRX configuration, but this is inefficient in terms of the signalling overhead involved particularly if dedicated signalling (per UE) is used.
A number of proposals and options will now be described that can help to address some of the issues discussed above.
Proposal 1 The Cell DRX/DTX configuration is defined around the SSB transmission location. The cell DTX/DRX configuration can be defined similarly to UE C-DRX -for example, a period of base station activity followed by an OFF duration; the possibility of one or more short DTX/DRX cycles within a long DTX/DRX cycle etc. Additional information defining the DTX/DRX configuration may also be provided, for example to define a configuration of resources for UL/DL signals or channels. For example, one DTX/DRX configuration may be configured with a PUCCH that allows for the UEs 3 to transmit Wake Up Signal, WUS, to the base station 5; whereas another configuration may use a specialized/new signal to wake up the base station 5. As another example, one DTX/DRX configuration may allow UEs 3 to transmit in preconfigured UL resources (e.g. SR, CG-PUSCH etc.) while another configuration may bar the UEs 3 from transmitting in preconfigured resources.
In this proposal, the base station 5 is ON or active for the transmission of data to UEs 3 or for the reception of data from UEs 3 around the bursts of SSB transmissions 110.
Communication between the UEs 3 and the base station 5 can be configured to start shortly before, shortly after or at the same instance as that of the SSB transmission position. The base station's OFF duration(s) is(are) configured within the gap between two consecutive SS bursts. This arrangement is illustrated in Fig. 7a, which shows the SS bursts 110 within the first half of every other 10ms radio frame. As can be seen from Fig. 7a, the SSB transmissions 110 do not extend over the full bandwidth defined for NR. As shown in Fig. 3, each SSB transmission requires only 20 RBs, whereas in NR, each OFDM symbol can extend over up to 275 RBs in the frequency domain leaving many other RBs for data communication with the UEs 3.
Fig. 7a also illustrates, above the 10ms radio frames, one cell DTX/DRX configuration 150-1 that can be defined in accordance with this proposal. As shown, the ON duration starts in the same slot as an SS burst and ends in the last slot containing the SS burst and the OFF duration extends until the next SS burst when the DTX/DRX cycle starts again. Fig. 7b illustrates another cell DTX/DRX configuration 150-2 that can be defined in accordance with this proposal -in this case with additional ON durations configured in the gap between adjacent SS bursts 110. As those skilled in the art will appreciate, various different cell DTX/DRX configurations 150 may be defined and some or all of the parameters that define the different cell DTX/DRX configurations 150 can be preconfigured in the base station 5 and the UEs 3 and mapped to the characteristics of the current SSB transmissions (for example the SS burst transmission periodicity, the pattern of SSBs in each SS burst etc). In addition or alternatively, some or all of the parameters that define the cell DTX/DRX configuration 150 may be configured by the network (e.g. by the base station 5) and mapped to the characteristics of the current SSB transmissions (such as the SS burst transmission periodicity, the pattern of SSBs in each SS burst etc). For example, an increase in the period between SS bursts can be mapped to more cell DTX/DRX configurations 150 (e.g. with different periodicities) whilst a reduced SS burst periodicity can be mapped to a lower number of associated cell DTX/DRX configurations 150. A number of alternative ways of mapping between the SSB transmission parameter(s) and the cell DTX/DRX pattern 150 will now be described.
Alternative 1 As one alternative, one cell DTX/DRX pattern is preconfigured in both the base station 5 and the UEs 3. Then the number of cell DTX/DRX cycles within the SSB transmission period is either: a) determined implicitly by the base station 5 and the UEs 3 from, for example, the SSB transmission periodicity and/or the SSB pattern (i.e. how many SSBs are transmitted in each SS burst); or b) indicated explicitly by the network (e.g. by the base station 5). Of course, the variable DTX/DRX parameter doesn't have to be the number of cycles within the SSB transmission period, other DTX/DRX variables could be defined by the network. Depending on the particular DTX/DRX variable(s) that is (are) not preconfigured, this (these) may be indicated by the network (e.g. by the base station 5) either through explicit signalling that indicates the particular DTX/DRX variable(s) or by linking the value(s) of the DTX/DRX variable(s) to the value of some other system variable that is defined by the network such as the subcarrier spacing and/or the carrier frequency that is used in the cell and/or the SSB transmission periodicity and/or the SSB pattern. A combination of both explicit signalling and implicit signalling to the UEs 3 can also be used to define the value(s) of the DTX/DRX variable(s).
Alternative 2 As another alternative for determining the cell DTX/DRX configuration, there may be stored in the base station 5 and the UEs 3 a one to one mapping (such as a look up table) that maps between one or more SSB transmission parameters and the cell DTX/DRX configuration. In this way, if the network changes the SSB transmission configuration, then when the UEs 3 are signalled with details of the new SSB configuration, the UEs 3 (and the base station 5) can map the new SSB configuration to the new cell DTX/DRX configuration. So, if the SSB configuration is changed to increase the periodicity of the SSB transmission (or reduce the number of SSBs that are transmitted in each SS burst), then the UEs 3 and the base station 5, can map this to a new cell DTX/DRX configuration that provides additional DTX/DRX cycles or that increases the ON duration of the cell DTX/DX cycle etc.; or if the SSB configuration is changed to decrease the periodicity of the SSB transmission (or increase the number of SSBs that are transmitted in each SS burst), then the UEs 3 and the base station 5, can map this to a new cell DTX/DRX configuration that reduces the number of cell DTX/DRX cycles or that reduces the ON duration of each cell DTX/DRX cycle. As a slight variation to this alternative, depending on what DTX/DRX parameters are preconfigured in the base station 5 and the UEs 3 and the DTX/DRX parameter values that are defined by the mapping, some cell DTX/DRX parameters may still need to be indicated to the UEs 3 by the base station 5 implicitly, explicitly or in an implicit and explicit manner.
Alternative 3 As another alternative for determining the cell DTX/DRX configuration, the UEs 3 and the base station 5 may be preconfigured with a one to many mapping between one or more SSB transmission parameters and cell DTX/DRX configurations. Which one of the DTX/DRX configurations is used for a given SSB transmission configuration is then indicated by the network (e.g. by the base station 5) separately. For example, if there are four possible cell DTX/DRX configurations for a given SSB configuration, then the base station 5 may transmit two signalling bits that identify which of the four cell DTX/DRX patterns is to be used. Alternatively, the base station 5 may indicate the value of one or more of the DTX/DRX parameter values which are needed to define the DTX/DRX configuration and the transmitted parameter value defines which one of the four possible cell DTX/DRX configurations is to be used. Values of different parameters related to cell DTX/DRX configuration can be indicated implicitly, explicitly or via a combination of implicit and explicit mechanisms.
Alternative 4 As another alternative for determining the cell DTX/DRX configuration, the UEs 3 and the base station 5 may be preconfigured with a fixed "minimum granularity" of on/off period (or the minimum granularity may be changed by the network from time to time). The minimum granularity may be defined in symbols, slots, subframes, frames or time (e.g. in ms). A multiplication factor (Non and Noff for ON and OFF durations, respectively) can then be used to determine the actual duration of the ON/OFF periods. The multiplication factor may be determined implicitly (for example from the SS burst periodicity) or it may be configured by the network (e.g. by the base station 5) explicitly in a semi-static or dynamic manner. The number of DTX/DRX cycles in the SSB transmission period may also be determined implicitly from the values of other signalled variables (such as from the SSB transmission period or SSB pattern or from some other variable) using for example, a look up table; or may be determined from explicit signalling from the network. Other DTX/DRX parameters can also be indicated implicitly, explicitly or via a combination of explicit and explicit signalling.
A worked example of this fourth alternative will now be given to explain in more detail how the cell DTX/DRX configuration may be determined in the UEs 3.
1) The network (e.g. the base station 5) broadcasts (for example in system information) the minimum granularity of the cell ON/OFF period. In this example, the base station broadcasts that the minimum granularity is one slot (= 1 ms).
2) The network (e.g. the base station 5) also broadcasts (or multicasts) a mapping of multiplication factor(s), to be used to determine the actual ON/OFF durations per cell DTX/DRX cycle. For example, the base station 5 broadcasts N. factors {1,2}, {1, 2, 4}, {1, 2, 4, 8} for SS burst transmission periodicities 5ms, 10ms, 20ms respectively and Noff factors {1,2}, {2, 3, 4}, {2, 6, 8, 12} for SS burst transmission periodicities 5ms, 10ms, 20ms respectively. The particular N. and NU to be used can then be determined from the current SS burst periodicity and a dedicated cell activation signalling or from some other signalling. So, for example, if the current SS burst transmission periodicity is 20 ms and the cell DTX/DRX activation signalling carries the indices 2 and 3 then that indicates to the UEs 3 that N. = 4 and that Noff = 12 respectively. (Note that the indices start at zero corresponding to the first value of the possible values). Of course, if there is just one multiplication factor for each SS burst periodicity or for each possible pattern of SSB transmissions in one burst, then the SS burst transmission periodicity or the pattern of SSB transmissions in each burst is enough to implicitly specify the multiplication factor.
3) The UEs 3 then apply the determined multiplication factor to the minimum granularity to determine the actual ON/OFF durations. So, for the example, where Non = 4 and that Non = 12 and the minimum granularity is set at one slot, the UEs 3 determine that the ON duration is 4 slots and the OFF duration is 12 slots per DTX/DRX cycle.
4) The starting slot for the first ON duration may be signalled separately by the network (e.g. the base station 5) or may be determined implicitly using, for example, the start slot/offset of the SS burst transmission.
5) The number of DTX/DRX cycles per SS burst period may also be signalled separately by the network (e.g. by the base station 5) or may be determined implicitly from the SS burst periodicity and the ON/OFF period per cycle. For example, when the SS burst periodicity is 20ms and Non = 4 ms and Nott = 12 ms, then there will only be one DTX/DRX cycle between two adjacent SS bursts.
Instead of relying on the network (e.g. the base station 5) to broadcast the mapping of multiplication factors to SS burst transmission periodicities, the network may indicate the multiplication factor(s) explicitly in a semi-static or dynamic manner. For example, the base station 5 may indicate to the UEs that Non = 4 and Noff = 12 in RRC signalling, in DTX/DRX activation signalling or in any other existing or new L1/L2 signalling. The signalling which indicates the multiplication factor can be UE specific, cell specific or group common (i.e. common to a group of UEs served by the base station cell 9).
Of course, other ways of informing the UEs of the cell DTX/DRX configuration may be used which do not necessarily depend on a mapping or association between SS burst transmission parameters and the cell DTX/DRX parameters.
The general operation of the base station 5 and of the UEs 3 in Proposal 1 can be summarised by the flow charts illustrated in Figure 8a and 8b respectively. In the case of the base station 5, the process (shown in Fig. 8a) includes a step s1 of determining a location of synchronization signals to be transmitted by the base station 5 within a frame. In step s3 the base station 5 determines a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration based on the location of the synchronization signals; and in step s5, the base station signals information to the UE to allow the UE to determine the location of the synchronization signals and the cell DTX/DRX configuration.
In the case of the UEs 3, the process (shown in Fig. 8b) includes a step s11 of receiving signalling information from the base station 5; a step s13 of determining a location (timing) of synchronization signals to be transmitted by the base station within a frame, using the signalling information; and a step s15 of determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the base station 5 based on the location of the synchronization signals.
Proposal 2 In this proposal, a minimum granularity of cell DTX/DRX on/off period is used, like in Alternative 4 of Proposal 1, but in this case without any mapping with respect to SS burst transmission parameters. In this proposal, the minimum granularity of cell DTX/DRX on/off period is either preconfigured in the base station 5 and the UEs 3 or configured by the network (e.g. by the base station 5) from time to time. The particular multiplication factor that is used to determine the actual ON/OFF durations per DTX/DRX cycle can then be determined implicitly from some other variable that is defined for the cell or explicitly signalled either semi-statically or dynamically by the network (e.g. by the base station 5). For example, the actual OFF duration (hence multiplication factor Noff) in a cycle may be determined based on the ON duration and the location of another configured channel/signal. The number of DTX/DRX cycles may also be implicitly or explicitly determined. Implicit determination of the parameters can be done based on rules that are preconfigured within the UEs 3 and within the base station 5. Other parameters related to cell DTX/DRX configuration can also be indicated implicitly, explicitly or via a combination of implicit and explicit mechanisms.
A worked example of this second proposal will now be given to help explain in more detail how the cell DTX/DRX configuration may be indicated to the UEs 3.
1) The network (e.g. the base station 5) broadcasts (for example in system information) the minimum granularity of the cell ON/OFF period. In this example, the base station 5 broadcasts that the minimum granularity is one slot (= 1 ms).
2) Resources for uplink (UL) and/or downlink (DL) signals or channels (such as the Physical Uplink Control Channel, PUCCH, a Configured Grant in the Physical Uplink Shared Channel, CG-PUSCH, a base station Wake Up Signal (WUS)) are configured for and indicated to the UEs 3 by the network (e.g. by the base station 5) in a cell specific or in a UE specific manner. For example, periodic PUCCH resources for a UE 3 to transmit a scheduling request (SR) are configured by the base station 5 in a UE specific manner and the WUS can be configured in a cell specific or in a UE group specific manner.
3) The network (e.g. the base station 5) also transmits a signal to indicate the multiplication factor to be used to determine the actual ON/OFF durations per cell DTX/DRX cycle. The network can transmit this indication from time to time in a semi-static or dynamic manner. So, for example, if Non = 4 and Riff = 12, this can be either broadcast in a cell specific manner (e.g. in system information (SI)), indicated in a group specific manner (e.g. using L1/L2 signalling) or configured UE specifically (e.g. using RRC signalling, or in Downlink Control Information, DCI etc.).
4) The UEs 3 then apply the determined multiplication factor to the minimum granularity to determine the actual ON/OFF durations. So, for the example where Non = 4 and that Non = 12 and the minimum granularity is set at one slot, the UEs 3 would determine that the ON duration is 4 slots and the OFF duration is 12 slots per DTX/DRX cycle.
5) The starting slot for the first ON duration may also be signalled separately by the network (e.g. the base station 5) or may be determined implicitly by the UEs using, for example, the location of an UL/DL resource that has been configured for the UEs.
6) The number of DTX/DRX cycles for which cell DTX/DRX is activated can be indicated to the UEs 3 for example via the activation signalling; or the DTX/DRX ON/OFF pattern can simply be repeated until the network (e.g. the base station 5) transmits DTX/DRX deactivation signalling to the UEs 3.
Instead of the network (e.g. the base station 5) explicitly transmitting the multiplication factors to the UEs 3, the UEs 3 may be able to determine the multiplication factor and, hence, the ON/OFF durations implicitly based on the configuration of other signals/channels and other rules which may be specified/configured that define the UE behaviour when cell DTX/DRX is configured. For example, if the UEs 3 are allowed to transmit in CG-PUSCH resources that are configured with a periodicity of 10ms when cell DTX/DRX is active; and Non = 4 is indicated in activation signalling transmitted by the base station 5 to the UEs 3, then the UEs 3 can determine that the DTX/DRX ON duration is 4 slots (= 4ms) and so, assuming that the start of a cell DTX/DRX cycle is aligned with the CG-PUSCH start location, then the OFF duration has to be 6 slots (corresponding to 6ms = 10ms -4ms) to allow the UEs 3 to be able to transmit in the configured CG-PUSCH resources.
The general operation of the base station 5 and of the UEs 3 in Proposal 2 can be summarised by the flow charts illustrated in Fig. 9a and Fig. 9b respectively. In the case of the base station 5, the process (shown in Fig. 9a) includes a step s21 of determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the base station 5, the cell DTX/DRX configuration defining an ON duration in which the base station 5 is active and configured to communicate with the UE and an OFF duration in which the base station 5 is inactive and configured not to communicate with the UE; a step s23 of determining from the ON duration and/or the OFF duration and a minimum granularity of the ON duration and/or the OFF duration, at least one multiplication factor that can be used to determine the ON duration and/or the OFF duration of the cell DTX/DRX configuration from the minimum granularity; and a step s25 of signalling to the UE information indicating one or more of: vi) the minimum granularity; vii) the at least one multiplication factor; viii) a parameter relating to a starting position for the cell ON duration; ix) a parameter relating to a number of cell DTX/DRX cycles to be performed; and x) a parameter relating to a periodicity of the cell DTX/DRX cycles.
In the case of the UEs 3, the process (shown in Fig. 9b) includes a step s31 of receiving signalling information from the base station 5 indicating one or more of: vi) the minimum granularity; vii) at least one multiplication factor; viii) a parameter relating to a starting position for a cell ON duration; ix) a parameter relating to a number of cell discontinuous transmission/discontinuous reception, DTX/DRX, cycles to be performed; x) a parameter relating to a periodicity of the cell DTX/DRX cycles; a step s33 of obtaining a minimum granularity of at least one of a cell ON duration and/or a cell OFF duration (which may be preprogrammed into the UE or may be signalled by the base station 5); a step s35 of determining at least one multiplication factor from the signalling information; and a step s37 of using the minimum granularity and the determined at least one multiplication factor to determine a cell DTX/DRX configuration for the base station 5 using the signalling information, the cell DTX/DRX configuration defining a cell ON duration in which the base station 5 is active and configured to communicate with the UE and a cell OFF duration in which the base station 5 is inactive and configured not to communicate with the UE.
Cell DTX/DRX Activation and UE Behaviour As mentioned above, it is important to consider the interaction between the operation of UEs operating under a legacy connected mode C-DRX together with cell DTX/DRX operation. Others have proposed that cell DTX/DRX over-rides the UE behaviour on UE DRX. In other words, UE DRX ON and OFF durations become aligned with the cell DTX/DRX ON and OFF durations. However, this may be inefficient in terms of power consumption for UEs 3 for which a longer UE DRX OFF duration could have been possible due to their specific traffic characteristics.
Proposal 3 The inventors propose therefore, that cell DTX/DRX is configured independently of UE DRX and such that UEs with inactivity durations longer than the cell inactivity duration (OFF duration) still stay inactive even when the cell has moved to the active state and is no longer in the inactive or OFF state. The network (e.g. the base station 5) can transmit signalling to the UEs 3 to indicate the cell DTX/DRX configuration/parameters via cell specific signalling, group common signalling or UE specific signalling or a combination thereof. Cell DTX/DRX activation is then enabled via L1/L2 signalling. This activation signalling can also configure some parameters of the cell DTX/DRX configuration that are to be activated in an implicit or an explicit manner. For example, there may be a preconfigured relationship between reception of the activation signalling and the start slot/offset of cell DTX/DRX. This relationship may be that the DTX/DRX cycle starts in the same slot in which the activation signalling is received or in some specific later slot that is defined relative to the slot in which the activation signalling is received (for example the next slot). Alternatively still, the starting slot/offset for cell DTX/DRX can be indicated explicitly by the base station 5 to the UEs 3 in the activation signalling. Another option is that whether the cell DTX/DRX cycle starts in a different slot/frame or the same slot/frame in which activation signalling is received by the UEs 3, is predefined in the UEs 3 and the offset (in terms of symbols) from the slot boundary (in the slot where the cell DTX/DRX cycle is configured to start) is indicated explicitly via the activation signalling. The slot in which the cell DTX/DRX cycle is to start may be either a fixed value or preconfigured in advance or indicated in the activation signalling.
The activation signalling may also indicate to the UEs 3 whether or not the cell DTX/DRX over-rides C-DRX of UEs. If it does not, then the network (e.g. the base station 5) also indicates to the UEs if the start slot/offset of a C-DRX cycle of UEs needs to be aligned with the start of a cell DTX/DRX cycle. UEs 3 without a legacy CDRX configuration can simply consider the active and inactive periods of the cell DTX/DRX configuration to control the reception and transmission of signals and channels as per the cell DTX/DRX configuration.
If the activation signalling transmitted from the base station 5 to the UEs 3 indicates that cell DTX/DRX does not over-ride UE C-DRX, then the behaviour of UEs with a legacy C-DRX configuration may be adapted as follows: 1) The cell DTX/DRX over-rides the UE behaviour on UE C-DRX if the C-DRX cycle(s) is completely contained within the cell DTX/DRX inactivity (OFF) period.
2) The behaviour of UEs having a legacy C-DRX configuration is not expected to change if its C_DRX cycle(s) is completely within the cell DTX/DRX active (ON) period.
3) If the C-DRX cycle of a UE overlaps with the cell DTX/DRX cycle such that the UE's inactive (OFF) duration overlaps with the cell DTX/DRX active and inactive durations, the UE 3 remains inactive (OFF) for the UE's entire inactive duration.
4) If the C-DRX cycle of a UE overlaps with the cell DTX/DRX cycle such that the UE's active (ON) duration overlaps with the cell DTX/DRX active and inactive durations, the UE 3 remains active (ON) only for the duration when the UE's and the cell's active (ON) duration overlap.
5) UEs 3 are only allowed to transmit during the active periods (ON) of the cell DRX configuration.
The general operation of the UEs 3 in Proposal 3 can be summarised by the flow chart illustrated in Fig. 10. As shown, the process includes a step s 41 of obtaining a UE discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the base station 5 and a UE OFF duration in which the UE is inactive and configured not to communicate with the base station 5; a step s43 of receiving information from the base station 5 indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the base station 5 defining a cell ON duration in which the base station 5 is active and configured to communicate with the UE and a cell OFF duration in which the base station 5 is inactive and configured not to communicate with the UE; and in a case where the UE OFF duration is longer than the cell OFF duration, in step s45 the UE is configured to remain inactive outside the cell OFF duration.
Data Transmission in Transition from Active to Inactive When the base station 5 transitions from its cell DTX/DRX active state to its cell DTX/DRX inactive state, this will affect the way in which the base station 5 and the UEs handle their HARQ (Hybrid Automatic Repeat Request) transmissions. Wth regard to the initial HARQ transmissions and from the uplink perspective, alignment between stopping of UE UL transmission and the base station 5 stopping data reception (due to its DRX configuration) should be considered. Therefore, it is important that the UE's DTX configuration effectively fully overlaps the cell's DRX configuration at the base station 5 side. This can be achieved by configuring the UEs 3 so that when the UE receives the cell DRX activation signaling, the UEs 3 suppress or stop their UL transmissions to the base station. Further, whilst it is possible for a UE 3 to wake up the base station (by requesting resources for an uplink transmission), in a preferred arrangement, the UEs are configured to suppress or not to make such dynamic UL transmissions to the base station 5, in order to allow the base station 5 to continue its network energy saving (NES) mode following cell DRX activation.
However, where the base station 5 has configured periodic resources for UE side UL transmissions (for example, CG-PUSCH based UL transmissions) and those resources are configured during times that the base station 5 is meant to be in its DRX inactive state, the base station 5 can be triggered to temporarily switch back into its DRX active state at those times, to allow the UL transmissions from the UEs 3 to be received using those pre-configured and activated CG resources.
With regard to HARQ (re)transmission, the following options can be considered to handle the ongoing or pending (re)transmission: Option 1: One option is to extend the cell's active period. In this case even though the cell DTX/DRX configuration indicates that the base station 5 should enter its inactive (OFF) state, in a case where there are ongoing or pending HARQ (re)transmission, the base station 5 and/or the UE are configured for a short transition period to complete the HARQ retransmission before switching to the inactive (OFF) state. During this transition period, new HARQ transmissions are not initiated either by the base station 5 or by the UEs 3.
Option 2: Another option, which is similar to Option 1 above, is to configure a timer (which can count up to some preconfigured value or count down from a preconfigured value) in both the base station 5 and in the UEs 3 which begins to run when the cell DTX/DRX configuration indicates that the base station 5 should enter its inactive (OFF) state; and whilst this timer is running the base station 5 and/or the UEs 3 are able to continue their HARQ (re)transmission before switching to the inactive (OFF) state.
Whilst the timer is running, new HARQ transmissions can be avoided, and only HARQ retransmission is allowed for the U Es 3.
Option 3: Another option for ongoing or pending HARQ (re)transmission, is to support early termination before switching the base station 5 to its inactive (OFF) state. A DCI (or UCI) can be used by the base station 5 (or the UE) to indicate to the UEs 3 (or to the base station 5) that the ongoing HARQ (re)transmission is terminated. The UE flushes its the buffer if it cannot decode the Transport Block (TB) based on the available TBs. The base station 5 and/or UEs 3 may also instruct their RLC or PDCP entities to stop data transmission and drop the needed retransmission, which means the RLC or PDCP entities will not initiate any retransmission in response to receiving a retransmission request from the peer protocol entity.
Option 4: For pending HARQ (re)transmission in the UL or the DL, delay preforming the (re)transmission until the next cell DTX/DRX active period.
Option 5: The base station 5 can disable cell DTX/DRX to cater for pending or ongoing HARQ (re)transmission.
The general operation of the UEs 3 and of the base station 5 in dealing with HARQ transmissions can be summarised by the flow charts illustrated in Fig. 11a and Fig. 11b respectively. In the case of the UEs 3, the process (shown in Fig. 11a) includes a step s51 of obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the base station 5 defining a cell ON duration in which the base station 5 is active and configured to communicate with the UE and a cell OFF duration in which the base station 5 is inactive and configured not to communicate with the UE; a step s53 of receiving an activation signal indicating activation of the cell DTX/DRX configuration at the base station 5; and a step s55 of suppressing uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
In the case of the base station, the process (shown in Fig. 11b) includes a step s61 of obtaining information indicating a cell DTX/DRX configuration of the base station 5 defining a cell ON duration in which the base station 5 is active and configured to communicate with the UE and a cell OFF duration in which the base station 5 is inactive and configured not to communicate with the UE; and a step s63 of transmitting an activation signal indicating to the UE activation of the cell DTX/DRX configuration at the base station to cause the UE to suppress uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
User Equipment Fig. 12 is a schematic block diagram illustrating the main components of a UE 3 as shown in Fig. 1.
As shown, the UE 3 has a transceiver circuit 310 that is operable to transmit signals to and to receive signals from a base station 5 via one or more antenna 330 (e.g., comprising one or more antenna elements). The UE 3 has a controller 370 to control the operation of the UE 3. The controller 370 is associated with a memory 390 and is coupled to the transceiver circuit 310. 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 350, 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 390 and/or may be downloaded via the telecommunications network or from a removable data storage device (RMD), for example.
The controller 370 is configured to control overall operation of the UE 3 by, in this example, program instructions or software instructions stored within memory 390. As shown, these software instructions include, among other things, an operating system 410, and a communications control module 430.
The communications control module 430 is operable to control the communication between the UE 3 and its serving base station(s) 5 (and other communication devices connected to the base station 5, such as further U Es and/or core network nodes). The communications control module 430 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 430 is also configured for the overall handling of receipt 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-static signalling (e.g., CSI-RS). The communications control module 430 is responsible, for example: for determining where to monitor for downlink control information (e.g., the location of CSSs / USSs, CORESETs, and associated PDCCH candidates to monitor); for determining the resources to be used by the UE 3 for transmission/reception of UUDL 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 SBFD communication, or the like); for determining which bandwidth part(s) are configured for the UE 3; for determining how uplink transmissions should be encoded; for applying any SBFD specific communication configurations appropriately; and the like. The communications control module 430 is configured to control communications in accordance with any of the proposals and options described above for determining the cell DTX/DRX configuration 450, for dealing with the interaction between the cell DTX/DRX configuration 450 and any legacy UE DRX configuration 470, using the SS burst configuration 480 that the UE 3 has been configured with and any timers 490 that are used for controlling the UE DRX operations.
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 510 for transmitting signals to and for receiving signals from the communication devices (such as UEs 3) via one or more antenna 530 (e.g. a single or multi-panel antenna array / massive antenna), and a core network interface 550 (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 570 to control the operation of the base station 5. The controller 570 is associated with a memory 590. Software may be pre-installed in the memory 590 and/or may be downloaded via the communications network 1 or from a removable data storage device (RMD), for example. The controller 570 is configured to control the overall operation of the base station 5 by, in this example, program instructions or software instructions stored within memory 590.
As shown, these software instructions include, among other things, an operating system 610 and a communications control module 630.
The communications control module 630 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 630 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 630 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-static signalling (e.g., CSI-RS). The communications control module 630 is responsible for managing full duplex (e.g., SBFD) communication including, where appropriate, the segregation of UL and DL communication via different physical antenna elements. The communications control module 630 is responsible, for example: for determining where to configure the UE 3 to monitor for downlink control information (e.g., the location of CSSs / USSs, 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 SBFD communication, or the like); for configuring bandwidth part(s) for the UE 3; for providing related configuration signalling to the UE 3; and the like. The communications control module 630 is configured to control communications in accordance with any of the proposals and options described above for signalling information to the UEs 3 to allow them to determine the cell DTX/DRX configuration, for using the SS burst configuration 680 and any timers 690 that are used for controlling the cell DTX/DRX operations.
Modifications and Alternatives As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above embodiments whilst still benefiting from the inventions embodied therein.
In the above embodiments, the base station transmitted various signalling from which the UEs 3 have been able to determine the cell DTX/DRX configuration. As those skilled in the art will appreciate, the base station 5 will have to determine the values to be signalled to allow the UEs to determine the relevant cell DTX/DRX parameter values using the inverse calculations performed by the UEs. If the cell DTX/DRX configuration is not defined by the base station 5 and is defined by some other network node, then the base station 5 may have to determine its own cell DTX/DRX configuration in the same way as the UEs 3.
It will be appreciated, for example, 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.
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 the invention, 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.
In the above embodiments, 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.
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 (10) 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.
The base station may comprise a 'distributed' base station having a central unit 'CU' and one or more separate distributed units (DUs).
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.
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.
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 loT devices, loT 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.
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.).
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.).
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.).
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.).
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.
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)).
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 (loT)", using a variety of wired and/or wireless communication technologies.
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. loT devices may comprise automated equipment that follow software instructions stored in an internal memory. loT devices may operate without requiring human supervision or interaction. loT devices might also remain stationary and/or inactive for a long period of time. loT devices may be implemented as a part of a (generally) stationary apparatus. loT devices may also be embedded in non-stationary apparatus (e.g. vehicles) or attached to animals or persons to be monitored/tracked.
It will be appreciated that loT 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.
It will be appreciated that loT 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 loT 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.
Service Area MTC applications Security Surveillance systems Backup for landline Control of physical access (e.g. to buildings) Car/driver security Tracking & Tracing Fleet Management Order Management Pay as you drive Asset Tracking Navigation Traffic information Road tolling Road traffic optimisation/steering Payment Point of sales Vending machines Gaming machines Health Monitoring vital signs Supporting the aged or handicapped Web Access Telemedicine points Remote diagnostics Remote Maintenance/Control Sensors Lighting Pumps Valves Elevator control Vending machine control Vehicle diagnostics Power Gas Metering Water Heating Grid control Industrial metering Digital photo frame Consumer Devices Digital camera eBook 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. Further, the above-described UE categories are merely examples of applications of the technical ideas and exemplary embodiments described in the present document.
Needless to say, these technical ideas and embodiments are not limited to the above-described UE and various modifications can be made thereto.
Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.
Claims (90)
- Claims 1. A method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: determining a location of synchronization signals to be transmitted by the access network node within a frame; determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals; and signalling information to the UE to allow the UE to determine the location of the synchronization signals and the cell DTX/DRX configuration.
- 2. The method of claim 1, wherein the cell DTX/DRX configuration defines a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE and wherein the cell ON duration is around the location of the synchronization signals within the frame.
- 3. The method of claim 2, wherein the cell ON duration extends over a period of time in which the synchronization signals are transmitted by the access network node.
- 4. The method according to claim 2 or 3, wherein the synchronization signals are transmitted in bursts in a periodic manner and the cell OFF duration is configured in a gap between adjacent bursts.
- 5. The method of claim 4, wherein the cell DTX/DRX configuration defines one or more cell ON durations in the gap between adjacent bursts.
- 6. The method of claim 4 or 5, wherein the synchronization signal bursts are transmitted in a periodic manner and wherein one or more parameters relating to the cell DTX/DRX configuration are mapped to characteristics of the periodic bursts of synchronization signals using predefined mapping data.
- The method of claim 6, wherein the mapping data is defined by a look up table.
- 8. The method of claim 6 or 7, wherein the one or more parameters relating to the cell DTX/DRX configuration are either preconfigured parameter values or are configured by a network node.
- 9. The method of any of claims 6 to 8, wherein the one or more parameters comprise one or more parameters selected from the group of: i) a parameter relating to a starting position for the cell ON duration; ii) a parameter relating to a starting position for the cell OFF duration; iii) a parameter relating to a number of DTX/DRX cycles to be performed; iv) a parameter relating to a periodicity of the DTX/DRX cycles.
- 10. The method of any of claims 6 to 9, wherein the cell DTX/DRX configuration includes a cell DTX/DRX pattern that defines the ON duration and the OFF duration and periodicity information indicating a DRX cycle interval at which the DTX/DRX pattern repeats and/or information indicating a number of times the DTX/DRX pattern is to be repeated.
- 11. The method of claim 10, wherein one cell DTX/DRX pattern is defined and the mapping data relates the synchronization signal burst periodicity to the number of DTX/DRX cycles within the synchronization signal burst periodicity.
- 12. The method of any of claims 6 to 9, wherein there is a one to one mapping between parameters that define the synchronization signal transmissions and the cell DTX/DRX configuration.
- 13. The method of any of claims 6 to 9, wherein there is a one to many mapping between parameters that define the synchronization signal transmissions and the cell DTX/DRX configuration.
- 14. The method of claim 13, wherein in a case where the synchronization signal burst periodicity increases, the mapping data maps to more cell DTX/DRX configurations and in a case where the synchronization signal burst periodicity decreases, the mapping data maps to fewer cell DTX/DRX configurations.
- 15. The method of any of claims 6 to 9, wherein a minimum granularity of the ON duration and/or the OFF duration is defined and the mapping data relates a parameter of the synchronization signal transmissions to one or more multiplication factors that can be used determine the cell ON duration and the cell OFF duration using the minimum granularity.
- 16. The method of claim 15, wherein in the case where the mapping data relates the parameter of the synchronization signal transmissions to a plurality of multiplication factors, the method further comprises transmitting signalling information to allow the UE to identify which of the plurality of multiplication factors are to be used to determine the cell ON duration and/or the cell OFF duration.
- 17. A method performed by a user equipment, UE, that is configured to communicate with an access network node, the method comprising: receiving signalling information from the access network node; determining a location of synchronization signals to be transmitted by the access network node within a frame, using the signalling information; and determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals.
- 18. The method of claim 17, wherein the cell DTX/DRX configuration defines a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE and wherein the cell ON duration is around the location of the synchronization signals within the frame.
- 19. The method of claim 18, wherein the cell ON duration extends over a period of time in which the synchronization signals are received from the access network node.
- 20. The method according to claim 18 or 19, wherein the synchronization signals are received in bursts in a periodic manner and the cell OFF duration is configured in a gap between adjacent bursts.
- 21. The method of claim 20, wherein the cell DTX/DRX configuration defines one or more cell ON durations in the gap between adjacent bursts.
- 22. The method of claim 20 or 21, wherein the synchronization signal bursts are received periodically and wherein one or more parameters relating to the cell DTX/DRX configuration are mapped to characteristics of the periodic bursts of synchronization signals using predefined mapping data.
- 23. The method of claim 22, wherein the mapping data is defined by a look up table.
- 24. The method of claim 22 or 23, wherein the one or more parameters relating to the cell DTX/DRX configuration are either preconfigured parameter values or are configured by a network node.
- 25. The method of any of claims 22 to 24, wherein the one or more parameters comprise one or more parameters selected from the group of: i) a parameter relating to a starting position for the cell ON duration; ii) a parameter relating to a starting position for the cell OFF duration; iii) a parameter relating to a number of DTX/DRX cycles to be performed; and iv) a parameter relating to a periodicity of the DTX/DRX cycles.
- 26. The method of any of claims 22 to 25, wherein the cell DTX/DRX configuration includes a cell DTX/DRX pattern that defines the ON duration and the OFF duration and periodicity information indicating a DRX cycle interval at which the DTX/DRX pattern repeats and/or information indicating a number of times the DTX/DRX pattern is to be repeated.
- 27. The method of claim 26, wherein one cell DTX/DRX pattern is defined and the mapping data relates the synchronization signal burst periodicity to the number of DTX/DRX cycles within the synchronization signal burst periodicity.
- 28. The method of any of claims 22 to 25, wherein there is a one to one mapping between parameters that define the synchronization signal transmissions and the cell DTX/DRX configuration.
- 29. The method of any of claims 22 to 25, wherein there is a one to many mapping between parameters that define the synchronization signal transmissions and the cell DTX/DRX configuration.
- 30. The method of claim 29, wherein in a case where the synchronization signal burst periodicity increases, the mapping data maps to more cell DTX/DRX configurations and in a case where the synchronization signal burst periodicity decreases, the mapping data maps to fewer cell DTX/DRX configurations.
- 31. The method of any of claims 22 to 25, wherein a minimum granularity of the ON duration and/or the OFF duration is defined and the mapping data relates a parameter of the synchronization signal transmissions to one or more multiplication factors that are used to determine the cell ON duration and the cell OFF duration using the minimum granularity.
- 32. The method of claim 31, wherein in the case where the mapping data relates the parameter of the synchronization signal transmissions to a plurality of multiplication factors, the method further comprises receiving signalling information from the access network node that allows the UE to identify which of the plurality of multiplication factors are to be used to determine the cell ON duration and/or the cell OFF duration.
- 33. An access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for determining a location of synchronization signals to be transmitted by the access network node within a frame; means for determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals; and means for signalling information to the UE to allow the UE to determine the location of the synchronization signals and the cell DTX/DRX configuration.
- 34. A user equipment, UE, that is configured to communicate with an access network node, the UE comprising: means for receiving signalling information from the access network node; means for determining a location of synchronization signals to be transmitted by the access network node within a frame, using the signalling information; and means for determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node based on the location of the synchronization signals.
- 35. A method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node, the cell DTX/DRX configuration defining an ON duration in which the access network node is active and configured to communicate with the UE and an OFF duration in which the access network node is inactive and configured not to communicate with the UE; determining from the ON duration and/or the OFF duration and a minimum granularity of the ON duration and/or the OFF duration, at least one multiplication factor that can be used to determine the ON duration and/or the OFF duration of the cell DTX/DRX configuration from the minimum granularity; and signalling to the UE information indicating one or more of: i) the minimum granularity; ii) the at least one multiplication factor; iii) a parameter relating to a starting position for the cell ON duration; iv) a parameter relating to a number of cell DTX/DRX cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles.
- 36. The method of claim 35, wherein the minimum granularity is either fixed or is signalled to the UE.
- 37. The method of claim 35 or 36, wherein one or more of the at least one multiplication factor and the number of cell DTX/DRX cycles is/are implicitly and/or explicitly indicated to the UE.
- 38. The method of claim 37, wherein the at least one multiplication factor is signalled to the UE in a cell specific manner, in a group specific manner or in a UE specific manner.
- 39. The method of any of claims 35 to 38, further comprising signalling resources for uplink and/or downlink signals and/or channels to the UE and wherein one or more parameters relating to the determined cell DTX/DRX configuration that are not transmitted to the UE depend on the signalled resources.
- 40. The method of claim 39, wherein the signalled resources are related to a location of the ON duration, a location of the OFF duration and/or the at least one multiplication factor.
- 41. The method of any of claims 35 to 40, further comprising transmitting an activation signal indicating when the cell DTX/DRX configuration is activated.
- 42. The method of any of claims 35 to 41, wherein the cell DTX/DRX cycles repeat until the access network node transmits a deactivation signal.
- 43. A method performed by a user equipment, UE, that is configured to communicate with access network node, the method comprising: receiving signalling information from the access network node indicating one or more of: i) the minimum granularity; ii) at least one multiplication factor; iii) a parameter relating to a starting position for a cell ON duration; iv) a parameter relating to a number of cell discontinuous transmission/discontinuous reception, DTX/DRX, cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles; obtaining a minimum granularity of at least one of a cell ON duration and/or a cell OFF duration; determining at least one multiplication factor from the signalling information; using the minimum granularity and the determined at least one multiplication factor to determine a cell DTX/DRX configuration for the access network node using the signalling information, the cell DTX/DRX configuration defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE.
- 44. The method of claim 43, wherein the minimum granularity is fixed and obtained from memory or is variable and the received signalling information indicates implicitly or explicitly the minimum granularity to the UE.
- 45. The method of claim 43 or 44, wherein the received signalling information indicates implicitly or explicitly one or more of: the at least one multiplication factor and the number of cell DTX/DRX cycles to the UE.
- 46. The method of claim 45, wherein the at least one multiplication factor is signalled to the UE in a cell specific manner, in a group specific manner or in a UE specific manner.
- 47. The method of any of claims 43 to 46, further comprising receiving second signalling information that indicates resources for uplink and/or downlink signals and/or channels to the UE and wherein the UE determines one or more parameters relating to the cell DTX/DRX configuration using the second signalling information.
- 48. The method of claim 47, wherein the UE is configured to determine a location of the ON duration, a location of the OFF duration and/or the at least one multiplication factor based on the resources indicated by the second signalling information.
- 49. The method of any of claims 43 to 48, further comprising receiving an activation signal from the access network node indicating when the cell DTX/DRX configuration is activated.
- 50. The method of any of claims 43 to 49, further comprising determining that the DTX/DRX cycle repeats until a cell DTX/DRX deactivation signal is received from the access network node.
- 51. An access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for determining a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration for the access network node, the cell DTX/DRX configuration defining an ON duration in which the access network node is active and configured to communicate with the UE and an OFF duration in which the access network node is inactive and configured not to communicate with the UE; means for determining from the ON duration and/or the OFF duration and a minimum granularity of the ON duration and/or the OFF duration, at least one multiplication factor that can be used to determine the ON duration and/or the OFF duration of the cell DTX/DRX configuration from the minimum granularity; and means for signalling to the UE information indicating one or more of: i) the minimum granularity; ii) the at least one multiplication factor; iii) a parameter relating to a starting position for the cell ON duration; iv) a parameter relating to a number of cell DTX/DRX cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles.
- 52. A user equipment, UE, that is configured to communicate with access network node, the UE comprising: means for receiving signalling information from the access network node indicating one or more of: i) the minimum granularity; ii) at least one multiplication factor; iii) a parameter relating to a starting position for a cell ON duration; iv) a parameter relating to a number of cell discontinuous transmission/discontinuous reception, DTX/DRX, cycles to be performed; v) a parameter relating to a periodicity of the cell DTX/DRX cycles; means for obtaining a minimum granularity of at least one of a cell ON duration and/or a cell OFF duration; means for determining at least one multiplication factor from the signalling information; and means for using the minimum granularity and the determined at least one multiplication factor to determine a cell DTX/DRX configuration for the access network node using the signalling information, the cell DTX/DRX configuration defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE.
- 53. A method performed by a user equipment, UE, that is configured to communicate with an access network node of a network, the method comprising: obtaining a UE discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; receiving information from the access network node indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
- 54. The method of claim 53, comprising receiving cell DTX/DRX configuration and parameters via cell specific signalling, group common signalling, UE specific signalling or a combination thereof.
- 55. The method of claim 53 or 54, further comprising receiving an activation signal from the access network node indicating when the cell DTX/DRX configuration is activated.
- 56. The method of claim 55, wherein the UE determines the start position for cell DTX/DRX based on the timing of when the activation signal is received or based on other signalling information received from the access network node.
- 57. The method of claim 55 or 56, wherein the activation signal indicates if the cell DTX/DRX over-rides any UE DRX configuration.
- 58. The method of claim 57, wherein if the activation signal indicates that cell DTX/DRX does not over-ride the UE DRX configuration then the UE controls its operation in accordance with one or more of the following: i) the cell DTX/DRX overrides the UE behaviour on UE DRX if the UE DRX cycle(s) fall completely within an OFF duration of the cell DTX/DRX configuration; ii) in a case where the UE DRX cycle overlaps with a cell DTX cycle such that the UE's OFF duration overlaps with the cell's ON duration and the cell's OFF duration, the UE remains inactive for its entire OFF duration; and iii) in a case where the UE DRX cycle overlaps with a cell DTX cycle such that the UE's ON duration overlaps with the cell's ON duration and the cell's OFF duration, the UE remains active only for the duration when the UE's and the cell's ON durations overlap; and iv) the UE only transmits signals to the access network node during ON durations of the cell DTX/DRX configuration.
- 59. The method of any of claims 53 to 58, further comprising determining that the DTX/DRX cycle repeats until a cell DTX/DRX deactivation signal is received from the access network node.
- 60. A method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: transmitting information to the UE indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein the UE is configured to operate in a discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
- 61. The method of claim 60, comprising transmitting cell DTX/DRX configuration and parameters via cell specific signalling, group common signalling, UE specific signalling or a combination thereof.
- 62. The method of claim 60 or 61, further comprising transmitting an activation signal from the access network node indicating when the cell DTX/DRX configuration is activated.
- 63. The method of claim 62, wherein the start position for cell DTX/DRX is based on the timing of when the activation signal is received or based on other signalling information received from the access network node.
- 64. The method of any of claims 62 or 63, wherein the activation signal indicates if the cell DTX/DRX over-rides any UE DRX configuration.
- 65. The method of claim 64, wherein if the activation signal indicates that cell DTX/DRX does not over-ride the UE DRX configuration then the access network node expects the UE to control its operation in accordance with one or more of the following: i) the cell DTX/DRX overrides the UE behaviour on UE DRX if the UE DRX cycle(s) fall completely within an OFF duration of the cell DTX/DRX configuration; ii) in a case where the UE DRX cycle overlaps with a cell DTX cycle such that the UE's OFF duration overlaps with the cell's ON duration and the cell's OFF duration, the UE remains inactive for its entire OFF duration; and iii) in a case where the UE DRX cycle overlaps with a cell DTX cycle such that the UE's ON duration overlaps with the cell's ON duration and the cell's OFF duration, the UE remains active only for the duration when the UE's and the cell's ON durations overlap; and iv) the UE only transmits signals to the access network node during ON durations of the cell DTX/DRX configuration. 15
- 66. The method of any of claims 60 to 61, further comprising repeating the cell DTX/DRX cycle until a cell DTX/DRX deactivation signal is transmitted by the access network node.
- 67. A user equipment, UE, that is configured to communicate with an access network node of a network, the UE comprising: means for obtaining a UE discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; and means for receiving information from the access network node indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
- 68. An access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for transmitting information to the UE indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; wherein the UE is configured to operate in a discontinuous transmission/discontinuous reception, DTX/DRX, configuration defining a UE ON duration in which the UE is active and configured to communicate with the access network node and a UE OFF duration in which the UE is inactive and configured not to communicate with the access network node; wherein in a case where the UE OFF duration is longer than the cell OFF duration, the UE is configured to remain inactive outside the cell OFF duration.
- 69. A method performed by a user equipment, UE, that is configured to communicate with an access network node of a network, the method comprising: obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; receiving an activation signal indicating activation of the cell DTX/DRX configuration at the access network node; and suppressing uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
- 70. The method of claim 69, wherein the dynamic UL transmissions include one or more Scheduling Requests, SRs, that request UL resources for the UE to transmit UL data.
- 71. The method of claim 69 or 70, wherein suppressing uplink transmissions does not include suppressing UL transmissions based on preconfigured periodic UL transmission resources.
- 72. The method of any of claims 69 to 71, further comprising extending the ON duration after the cell DTX/DRX configuration has been activated to allow for ongoing or pending Hybrid Automatic Repeat Request, HARQ, transmissions or retransmissions before switching to the inactive mode.
- 73. The method of claim 72, wherein during the extended ON duration. new HARQ transmissions are not initiated.
- 74. The method of claim 72 or 73, wherein the ON duration is extended until the ongoing or pending HARQ transmissions have been completed or for a predetermined time.
- 75. The method of any of claims 72 to 74, wherein during the extended period of the ON duration the UE only transmits HARQ retransmissions.
- 76. The method of any of claims 69 to 71, further comprising receiving an HARQ early termination signal from the access network node prior to the cell entering into an OFF duration and terminating any HARQ transmissions or retransmissions.
- 77. The method of claim 76, further comprising flushing a transmission buffer of a current Transport Block, TB, if the UE cannot decode the TB based on available TBs.
- 78. The method of any of claims 69 to 71, further comprising delaying the transmission or retransmission of a pending HARQ until the next cell ON duration.
- 79. A method performed by an access network node that is configured to communicate with a user equipment, UE, the method comprising: obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; transmitting an activation signal indicating to the UE activation of the cell DTXJDRX configuration at the access network node to cause the UE to suppress uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
- 80. The method of claim 79, wherein the dynamic UL transmissions include one or more Scheduling Requests, SRs, that request UL resources for the UE to transmit UL 35 data.
- 81. The method of claim 79 or 80, further comprising temporarily entering the active mode during an OFF duration to receive UL transmissions on preconfigured periodic UL transmission resources.
- 82. The method of any of claims 79 to 81, further comprising extending the ON duration after the cell DTX/DRX configuration has been activated to allow for ongoing or pending Hybrid Automatic Repeat Request, HARQ, transmissions or retransmissions before switching to the inactive mode.
- 83. The method of claim 82, wherein during the extended ON duration, new HARQ transmissions are not initiated.
- 84. The method of claim 82 or 83, wherein the ON duration is extended until the ongoing or pending HARQ transmissions have been completed or for a predetermined time.
- 85. The method of any of claims 82 to 84, wherein during the extended period of the ON duration receiving only HARQ retransmissions.
- 86. The method of any of claims 79 to 81, further comprising transmitting an HARQ early termination signal to the UE prior to the access network node entering into an OFF duration and terminating any HARQ transmissions or retransmissions.
- 87. The method of claim 86, further comprising flushing a transmission buffer of a current Transport Block, TB, if the access network node cannot decode the TB based on available TBs.
- 88. The method of any of claims 79 to 81, further comprising delaying the transmission or retransmission of a pending HARQ until the next cell ON duration. 30
- 89. A user equipment, UE, that is configured to communicate with an access network node of a network, the UE comprising: means for obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; means for receiving an activation signal indicating activation of the cell DTX/DRX configuration at the access network node; and means for suppressing uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
- 90. An access network node that is configured to communicate with a user equipment, UE, the access network node comprising: means for obtaining information indicating a cell discontinuous transmission/discontinuous reception, DTX/DRX, configuration of the access network node defining a cell ON duration in which the access network node is active and configured to communicate with the UE and a cell OFF duration in which the access network node is inactive and configured not to communicate with the UE; and means for transmitting an activation signal indicating to the UE activation of the cell DTX/DRX configuration at the access network node to cause the UE to suppress uplink, UL, transmissions during the cell OFF durations including dynamic UL transmission.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2301961.5A GB2626994A (en) | 2023-02-10 | 2023-02-10 | Communication system |
| PCT/JP2023/044971 WO2024166533A1 (en) | 2023-02-10 | 2023-12-15 | Access network node, user equipment, and methods thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2301961.5A GB2626994A (en) | 2023-02-10 | 2023-02-10 | Communication system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB202301961D0 GB202301961D0 (en) | 2023-03-29 |
| GB2626994A true GB2626994A (en) | 2024-08-14 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2301961.5A Pending GB2626994A (en) | 2023-02-10 | 2023-02-10 | Communication system |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2626994A (en) |
| WO (1) | WO2024166533A1 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180049270A1 (en) * | 2016-08-12 | 2018-02-15 | Qualcomm Incorporated | Methods and apparatus for cell discontinuous transmission (dtx)scheduling |
| CN108134657A (en) * | 2016-12-01 | 2018-06-08 | 维沃移动通信有限公司 | A kind of processing method of synchronizing signal, the network equipment and terminal device |
-
2023
- 2023-02-10 GB GB2301961.5A patent/GB2626994A/en active Pending
- 2023-12-15 WO PCT/JP2023/044971 patent/WO2024166533A1/en unknown
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180049270A1 (en) * | 2016-08-12 | 2018-02-15 | Qualcomm Incorporated | Methods and apparatus for cell discontinuous transmission (dtx)scheduling |
| CN108134657A (en) * | 2016-12-01 | 2018-06-08 | 维沃移动通信有限公司 | A kind of processing method of synchronizing signal, the network equipment and terminal device |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2024166533A1 (en) | 2024-08-15 |
| GB202301961D0 (en) | 2023-03-29 |
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