Method, apparatus and computer program

Abstract

There is provided a first apparatus comprising means for: receiving, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switching the at least one transmission configuration indicator state; and sending, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

Description

[0001] METHOD, APPARATUS AND COMPUTER PROGRAM

[0002] TECHNICAL FIELD

[0003] Various example embodiments of this disclosure relate to a method, apparatus, system and computer program and in particular but not exclusively to switching transmission configuration indicator state.

[0004] BACKGROUND

[0005] A communication network can be seen as a facility that enables communications between two or more communication devices or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. A communication device may be provided with a service by an application server.

[0006] Such communication networks operate in accordance with standards such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of standards provided by 3GPP are the so-called 3GPP standards for cellular technology generations, such as 3GPP standards for 4G technology and 3GPP standards for 5G technology.

[0007] SUMMARY

[0008] Some example embodiments of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the various example embodiments of this disclosure, nor are they intended to be used to limit the scope of thereof. Other features, aspects, and elements will be apparent to a person skilled in the art in view of this disclosure. For example, it should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described below.

[0009] According to an aspect, there is provided a first apparatus comprising means for: receiving, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switching the at least one transmission configuration indicator state; and sending, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0010] The at least one indication may comprise a first indication to switch from a first transmission configuration indicator state to a second transmission configuration indicator state, and wherein the switching comprises switching from the first transmission configuration indicator state to the second transmission configuration indicator state.

[0011] The at least one indication may further comprise a second indication to switch from a third transmission configuration indicator state to a fourth transmission configuration indicator state, and wherein the switching further comprises switching from the third transmission configuration indicator state to the fourth transmission configuration indicator state.

[0012] The first and second indication may be received from a first transmission reception point in separate indications. The first and second indication may be received from the first transmission reception point in a joint indication. The first indication may be received from a first transmission reception point and the second indication may be received from a second transmission reception point.

[0013] The first and second indication may be received from the first transmission reception point in the separate indications or in the joint indication, and the first transmission configuration indicator state and the second transmission configuration indicator state may be one of an uplink transmission configuration indicator state and a downlink transmission configuration indicator state, and wherein the third transmission configuration indicator state and the fourth transmission configuration indicator state may be the other of the uplink transmission configuration indicator state and the downlink transmission configuration indicator state.

[0014] The first indication may be received from the first transmission reception point and the second indication may be received from the second transmission reception point, and wherein: the first transmission configuration indicator state and the second transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the second transmission reception point; or the first transmission configuration indicator state and the second transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the second transmission reception point.

[0015] Sending, to the at least one transmission reception point, the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state may comprise: sending, to the first transmission reception point, a third indication that the first apparatus has switched from the first transmission configuration indicator state to the second transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second transmission configuration indicator state; and sending, to the second transmission reception point, a fourth indication that the first apparatus has switched from the third transmission configuration indicator state to the fourth transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth transmission configuration indicator state.

[0016] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known to the first apparatus or unknown to the first apparatus, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth transmission configuration indicator state and the reference signal remains detectable to the first apparatus.

[0017] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state and / or a joint downlink / uplink transmission configuration indicator state that is known to the first apparatus and may be associated with a path loss reference signal, and wherein measurements of the path loss reference signal may be either maintained or not maintained by the first apparatus.

[0018] Switching the at least one transmission configuration indicator state may be associated with a required time period within which the switching is to be completed.

[0019] Sending the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be performed before expiry of the required time period.

[0020] The at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be comprised in a medium access control control element or uplink control information.

[0021] Sending the at least one indication may comprise: sending the at least one indication after completion of each of the at least one transmission configuration indicator state switch; sending the at least one indication after completion of a last of the at least one transmission configuration indicator state switch; sending the at least one indication after completion of an uplink transmission configuration indicator state switch; or sending the at least one indication after completion of a downlink transmission configuration indicator state switch.

[0022] The means may be further for: sending, to the at least one transmission reception point, information indicating the first apparatus’ capability for either: performing transmission and / or reception using a transmission configuration indicator state from before the transmission configuration indicator state switch for longer than a required time; and / or performing transmission and / or reception using a transmission configuration indicator state from after the transmission configuration indicator state switch earlier than a required time.

[0023] The at least one indication to switch the at least one transmission configuration indicator state may be based at least in part on the information indicating the first apparatus’ capability for performing transmission and / or reception using the transmission configuration indicator state from before the transmission configuration indicator state switch for longer than the required time; and / or performing transmission and / or reception using the transmission configuration indicator state from after the transmission configuration indicator state switch earlier than the required time

[0024] The means may be further for: sending one or more uplink transmissions to the at least one transmission reception point based on the switched at least one transmission configuration indicator state; and / or receiving one or more downlink transmissions from the at least one transmission reception point based on the switched at least one transmission configuration indicator state.

[0025] According to an aspect there is provided a second apparatus comprising means for: sending, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receiving, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state; and scheduling one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0026] The at least one indication may comprise a first indication to switch from a first transmission configuration indicator state to a second transmission configuration indicator state.

[0027] The at least one indication may further comprise a second indication to switch from a third transmission configuration indicator state to a fourth transmission configuration indicator state.

[0028] The first and second indication may be sent to the first apparatus in separate indications; or the first and second indication may be sent to the first apparatus in a joint indication.

[0029] The first transmission configuration indicator state and the second transmission configuration indicator state may be one of an uplink transmission configuration indicator state and a downlink transmission configuration indicator state, and wherein the third transmission configuration indicator state and the fourth transmission configuration indicator state may be the other of the uplink transmission configuration indicator state and the downlink transmission configuration indicator state.

[0030] The second apparatus may comprise a plurality of transmission reception points comprising at least a first transmission reception point and a second transmission reception point; and sending the at least one indication to switch the at least one transmission configuration indicator state may comprise sending the first indication to the first apparatus via the first transmission reception point and the second indication to the first apparatus via the second transmission reception point.

[0031] The first transmission configuration indicator state and the second transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the second transmission reception point; or the first transmission configuration indicator state and the second transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the second transmission reception point.

[0032] Receiving the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may comprise: receiving, from the first apparatus via the first transmission reception point, a third indication that the first apparatus has switched from the first transmission configuration indicator state to the second transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second transmission configuration indicator state; and receiving, from the first apparatus via the second transmission reception point, a fourth indication that the first apparatus has switched from the third transmission configuration indicator state to the fourth transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth transmission configuration indicator state.

[0033] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known to the first apparatus or unknown to the first apparatus, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth transmission configuration indicator state and the reference signal remains detectable to the first apparatus.

[0034] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state and / or a joint downlink / uplink transmission configuration indicator state that is known to the first apparatus and may be associated with a path loss reference signal, and wherein measurements of the path loss reference signal may be either maintained or not maintained by the first apparatus.

[0035] Switching the at least one transmission configuration indicator state may be associated with a required time period within which the switching is to be completed.

[0036] The at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be received before expiry of the required time period.

[0037] The at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be comprised in a medium access control control element or uplink control information.

[0038] The means may be further for: receiving, from the first apparatus, information indicating the first apparatus’s capability for either: performing transmission and / or reception using a transmission configuration indicator state from before the transmission configuration indicator state switch for longer than a required time; and / or performing transmission and / or reception using a transmission configuration indicator state from after the transmission configuration indicator state switch earlier than a required time.

[0039] The at least one indication to switch the at least one transmission configuration indicator state may be based at least in part on the information indicating the first apparatus’s capability for performing transmission and / or reception using the transmission configuration indicator state from before the transmission configuration indicator state switch for longer than the required time; and / or performing transmission and / or reception using the transmission configuration indicator state from after the transmission configuration indicator state switch earlier than the required time.

[0040] According to an aspect, there is provided a first apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switch the at least one transmission configuration indicator state; and send, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0041] The at least one indication may comprise a first indication to switch from a first transmission configuration indicator state to a second transmission configuration indicator state, and the at least one processor may be configured to cause the first apparatus to switch from the first transmission configuration indicator state to the second transmission configuration indicator state.

[0042] The at least one indication may further comprise a second indication to switch from a third transmission configuration indicator state to a fourth transmission configuration indicator state, and the at least one processor may be configured to cause the first apparatus to switch from the third transmission configuration indicator state to the fourth transmission configuration indicator state. The first and second indication may be received from a first transmission reception point in separate indications. The first and second indication may be received from the first transmission reception point in a joint indication. The first indication may be received from a first transmission reception point and the second indication may be received from a second transmission reception point.

[0043] The first and second indication may be received from the first transmission reception point in the separate indications or in the joint indication, and the first transmission configuration indicator state and the second transmission configuration indicator state may be one of an uplink transmission configuration indicator state and a downlink transmission configuration indicator state, and wherein the third transmission configuration indicator state and the fourth transmission configuration indicator state may be the other of the uplink transmission configuration indicator state and the downlink transmission configuration indicator state.

[0044] The first indication may be received from the first transmission reception point and the second indication may be received from the second transmission reception point, and wherein: the first transmission configuration indicator state and the second transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the second transmission reception point; or the first transmission configuration indicator state and the second transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the second transmission reception point.

[0045] The at least one processor may be configured to cause the first apparatus to: send, to the first transmission reception point, a third indication that the first apparatus has switched from the first transmission configuration indicator state to the second transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second transmission configuration indicator state; and send, to the second transmission reception point, a fourth indication that the first apparatus has switched from the third transmission configuration indicator state to the fourth transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth transmission configuration indicator state.

[0046] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known to the first apparatus or unknown to the first apparatus, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth transmission configuration indicator state and the reference signal remains detectable to the first apparatus.

[0047] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state and / or a joint downlink / uplink transmission configuration indicator state that is known to the first apparatus and may be associated with a path loss reference signal, and wherein measurements of the path loss reference signal may be either maintained or not maintained by the first apparatus.

[0048] The at least one processor may be configured to cause the first apparatus to complete the switch of the at least one transmission configuration indicator state within an associated required time period.

[0049] The at least one processor may be configured to cause the first apparatus to send the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state before expiry of the required time period.

[0050] The at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be comprised in a medium access control control element or uplink control information. The at least one processor may be configured to cause the first apparatus to: send the at least one indication after completion of each of the at least one transmission configuration indicator state switch; send the at least one indication after completion of a last of the at least one transmission configuration indicator state switch; send the at least one indication after completion of an uplink transmission configuration indicator state switch; or send the at least one indication after completion of a downlink transmission configuration indicator state switch.

[0051] The at least one processor may be configured to cause the first apparatus to: send, to the at least one transmission reception point, information indicating the first apparatus’ capability for either: performing transmission and / or reception using a transmission configuration indicator state from before the transmission configuration indicator state switch for longer than a required time; and / or performing transmission and / or reception using a transmission configuration indicator state from after the transmission configuration indicator state switch earlier than a required time.

[0052] The at least one indication to switch the at least one transmission configuration indicator state may be based at least in part on the information indicating the first apparatus’ capability for performing transmission and / or reception using the transmission configuration indicator state from before the transmission configuration indicator state switch for longer than the required time; and / or performing transmission and / or reception using the transmission configuration indicator state from after the transmission configuration indicator state switch earlier than the required time

[0053] The at least one processor may be configured to cause the first apparatus to: send one or more uplink transmissions to the at least one transmission reception point based on the switched at least one transmission configuration indicator state; and / or receive one or more downlink transmissions from the at least one transmission reception point based on the switched at least one transmission configuration indicator state.

[0054] According to an aspect, there is provided a second apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: send, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receive, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state; and schedule one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0055] The at least one indication may comprise a first indication to switch from a first transmission configuration indicator state to a second transmission configuration indicator state.

[0056] The at least one indication may further comprise a second indication to switch from a third transmission configuration indicator state to a fourth transmission configuration indicator state.

[0057] The first and second indication may be sent to the first apparatus in separate indications; or the first and second indication may be sent to the first apparatus in a joint indication.

[0058] The first transmission configuration indicator state and the second transmission configuration indicator state may be one of an uplink transmission configuration indicator state and a downlink transmission configuration indicator state, and wherein the third transmission configuration indicator state and the fourth transmission configuration indicator state may be the other of the uplink transmission configuration indicator state and the downlink transmission configuration indicator state.

[0059] The second apparatus may comprise a plurality of transmission reception points comprising at least a first transmission reception point and a second transmission reception point; and the at least one processor may be configured to cause the second apparatus to send the first indication to the first apparatus via the first transmission reception point and the second indication to the first apparatus via the second transmission reception point.

[0060] The first transmission configuration indicator state and the second transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state associated with the second transmission reception point; or the first transmission configuration indicator state and the second transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state may be a downlink transmission configuration indicator state associated with the second transmission reception point.

[0061] The at least one processor may be configured to cause the second apparatus to: receive, from the first apparatus via the first transmission reception point, a third indication that the first apparatus has switched from the first transmission configuration indicator state to the second transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second transmission configuration indicator state; and receive, from the first apparatus via the second transmission reception point, a fourth indication that the first apparatus has switched from the third transmission configuration indicator state to the fourth transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth transmission configuration indicator state.

[0062] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known to the first apparatus or unknown to the first apparatus, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth transmission configuration indicator state and the reference signal remains detectable to the first apparatus.

[0063] The second transmission configuration indicator state and / or the fourth transmission configuration indicator state may be an uplink transmission configuration indicator state and / or a joint downlink / uplink transmission configuration indicator state that is known to the first apparatus and may be associated with a path loss reference signal, and wherein measurements of the path loss reference signal may be either maintained or not maintained by the first apparatus. The at least one processor may be configured to cause the second apparatus to complete the switch of the at least one transmission configuration indicator state within an associated required time period.

[0064] The at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be received before expiry of the required time period.

[0065] The at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state may be comprised in a medium access control control element or uplink control information.

[0066] The at least one processor may be configured to cause the second apparatus to: receive, from the first apparatus, information indicating the first apparatus’s capability for either: performing transmission and / or reception using a transmission configuration indicator state from before the transmission configuration indicator state switch for longer than a required time; and / or performing transmission and / or reception using a transmission configuration indicator state from after the transmission configuration indicator state switch earlier than a required time.

[0067] The at least one indication to switch the at least one transmission configuration indicator state may be based at least in part on the information indicating the first apparatus’s capability for performing transmission and / or reception using the transmission configuration indicator state from before the transmission configuration indicator state switch for longer than the required time; and / or performing transmission and / or reception using the transmission configuration indicator state from after the transmission configuration indicator state switch earlier than the required time.

[0068] According to an aspect, there is provided a method performed by a first apparatus, the method comprising: receiving, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switching the at least one transmission configuration indicator state; and sending, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0069] According to an aspect, there is provided a method performed by a second apparatus, the method comprising: sending, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receiving, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state; and scheduling one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0070] According to an aspect, there is provided a computer readable medium comprising instructions which, when executed by a first apparatus, cause the first apparatus to perform at least the following: receiving, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switching the at least one transmission configuration indicator state; and sending, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0071] According to an aspect, there is provided a computer readable medium comprising instructions which, when executed by a second apparatus, cause the second apparatus to perform at least the following: sending, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receiving, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state; and scheduling one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

[0072] According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method according to any of the preceding aspects.

[0073] In the above, many different aspects have been described. As previously noted, it should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above. Other features, aspects, and elements will become apparent in view of the following.

[0074] DESCRIPTION OF FIGURES

[0075] Some example embodiments will now be described, by way of non-limiting and illustrative example only, with reference to the accompanying Figures (FIGs.) in which:

[0076] FIG. 1 shows a representation of a 5thgeneration communication system;

[0077] FIG. 2 shows a representation of an apparatus for the communication system of FIG. 1 according to some example embodiments;

[0078] FIG. 3 shows a representation of an apparatus according to some example embodiments;

[0079] FIG. 4 shows a methods according to some examples;

[0080] FIGs. 5 to 7 illustrate different transmission configuration indicator state switch reporting scenarios according to some examples;

[0081] FIGs. 8 and 9 show signalling exchanges according to some examples; and

[0082] FIG. 10 shows a schematic representation of an apparatus according to some examples.

[0083] DETAIEED DESCRIPTION

[0084] In the following various example embodiments are explained with reference to communication devices capable of communication with a communication system. Before explaining in detail the various example embodiments of this disclosure, a 5thgeneration communication system (5GS), an access network and a core network (5GC) thereof, and communication devices are briefly explained with reference to FIG. 1, 2 and 3.

[0085] FIG. 1 shows a schematic representation of a 5G communication system (5GS). The 5GS may comprise a user equipment (UE) or Terminal 100, an access network, such as a 5G radio access network (5G-RAN) 101 or next generation radio access network (NG-RAN), and a 5G core network 102 including one or more application functions 103. An application function 103 may be deployed in the 5GS as trusted application function or may be deployed or host on one or more application servers of the data network (DN) 104. Such application functions are untrusted application functions. The 5GS connects the UE to a data network the access network and the 5GC 102 (e.g., a UPF of the 5GC).

[0086] The 5G-RAN 101 may comprise one or more radio access nodes, such as a gNodeB (gNB). A gNB may include one or more gNodeB (gNB) distributed units (DUs) connected to one or more gNodeB (gNB) centralized units (CUs).

[0087] The 5GC may comprise the following network functions: Network Slice Selection Function (NSSF); Network Exposure Function (NEF) 105; Network Repository Function (NRF); Policy Control Function (PCF); Unified Data Management (UDM) 106; Application Function (AF) 103; Authentication Server Function (AUSF) 107; an Access and Mobility Management Function (AMF) 108; Session Management Function (SMF) 109; and a user plane function (UPF) 110. FIG. 1 also shows the various interfaces (Nl, N2 etc.) that may be implemented between the various elements of the system.

[0088] FIG. 2 illustrates an example of a control apparatus 200 for controlling a function of the access network (e.g. , a 5G-RAN or the NG-RAN illustrated in FIG. 1 ) of FIG. 1. The control apparatus 200 may comprise at least one random access memory (RAM) 211a, at least on read only memory (ROM) 211b, at least one processor 212, 213 and a network interface 214. The at least one processor 212, 213 may be coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. Execution of the software code 215 may, for example, cause the apparatus to perform operations for controlling a function of the access network. The software code 215 may be stored in the ROM 211b. The control apparatus 200 may be interconnected with another control apparatus 200 for controlling another function of the 5G-RAN or the NG-RAN. In some embodiments, each function of the 5G-RAN or the NG-RAN is deployed or hosted on a control apparatus 200. In alternative embodiments, two or more functions of the 5G-RAN or the NG-RAN may share a control apparatus.

[0089] FIG. 3 illustrates an example of a communication device 300, such as the UE of FIG. 1. The communication device 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples of a communication device 300 comprise a user equipment, a mobile station (MS) or mobile device, such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, an Internet of things (loT) type communication device or any combinations of these or the like. The communication device 300 may comprise a transceiver for transmitting and / or receiving, for example, wireless signals carrying communications, for example radio signals. The communications may be one or more of voice, electronic mail (email), text messages, multimedia data, machine data and so on.

[0090] The communication device 300 may receive wireless signals (e.g., radio signals) over an air or radio interface 307 via appropriate apparatus for receiving and may transmit wireless signals via appropriate apparatus for transmitting radio signals. In FIG. 3 transceiver is designated schematically by block 306. The transceiver 306 may comprise, for example, a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device and may comprise one or more antenna elements. The antenna arrangement may be a multi-input multi output (MIMO) antenna.

[0091] The communication device 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access networks (e.g., the 5G-RAN or NG-RAN illustrated in FIG. 1) and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may, for example, allow to perform one or more operations of the communication device. The software code 308 may be stored in the ROM 302a. The processor, the ROM, and the RAM, the transceiver and other circuitry of the communication device (e.g., a modem) can be provided on a circuit board, in chipsets, or in a system on chip. The circuit board, chipsets or system on chip is denoted by reference 304. The communication device 300 may optionally have a user interface, such as keypad 305, a touch sensitive screen or a pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of communication device.

[0092] An apparatus, such as UE 100, may be configured to operate according to one or more transmission configuration indicator (TCI) states. The TCI state may be a separate uplink (UL) TCI state, a separate downlink (DL) TCI state, or a joint DL / UL TCI state (the joint DL / UL TCI state may be a single TCI state that is used for both DL and UL).

[0093] The TCI state may indicate information for the apparatus to use when performing uplink and / or downlink transmissions between the apparatus and a transmission reception point (TRP) of a communications network (e.g., a 5G or 6G network). The TRP point may be provided by an access node, such as RAN 101. For instance, the TCI state may indicate that a certain target reference signal is quasi-co-located (QCLed) with a certain source reference signal. There may be different QCL types (e.g., type A, B, C, D as specified in 5G). The TCI state indication may allow for example the UE to receive a target reference signal by exploiting, in the channel estimation, some parameters that have already been computed by the UE when receiving the source reference signal. Examples of such parameters include but are not limited only to Doppler shift, Doppler spread etc. The parameters may depend on the QCL type.

[0094] The apparatus may be configured with a different TCI state for different TRPs. For example the apparatus may be configured with a first DL TCI state for a first TRP and a second DL TCI state for a second TRP. The first and second TRPs may be provided by a same access node or may be provided by different access nodes.

[0095] The network may indicate to the apparatus that the apparatus is to switch TCI states - for example to switch from a first TCI state (which may be referred to herein as an “old TCI state”) to a second TCI state (which may be referred to herein as a “target TCI state”). This may allow the network to dynamically adapt transmission parameters, for example based on changing channel conditions and network requirements. The network may therefore send, to the apparatus, an indication to switch TCI state(s) (e.g., switch from a first UL TCI state to a second UL TCI state and / or from a first DL TCI state to a second DL TCI state). The indication may indicate the target TCI state(s) that the apparatus is to switch to, for example in terms of a TCI state identifier (e.g., TCI#0, TCI#1 etc.). The indication may be comprised in a medium access control (MAC) control element (CE). The apparatus, upon receiving the indication, may then switch the TCI state(s) accordingly.

[0096] According to some examples (e.g., as described in 3GPP TS 38.133, sections 8.15 and 8.16), the apparatus may be required to be able to receive signalling with the target DL TCI state after a first required time and / or be able to receive signalling with the old DL TCI state until expiry of a second required time. The first and second required time may be defined for example by a number of slots or time period. The first and second required time may be different. The first and second required time may vary depending on certain conditions.

[0097] In some examples when the target DL TCI state is known for a DL TCI state switch and there is a single TRP, then upon receiving the indication in slot n, the apparatus may be required to be able to receive signalling (e.g., dedicated PDCCH / PDSCH) with the target DL TCI state at the first slot that is after slot: n+ THARQ + 3Nss"btframe'k+ TOk*(Tfirst-ssB + TssB-proc) / NR slot length

[0098] The apparatus may also be required to receive signalling (e.g., dedicated PDCCH / PDSCH) with the old DL TCI state until slot: subframe, p n+ THARQ + 3N slot where:

[0099] • THARQ is the timing between DL data transmission and acknowledgement;

[0100] • Tfirst-SSB is time to first synchronization signal block (SSB) transmission after the indication to switch TCI states (e.g. MAC CE) is decoded by the apparatus (the SSB may be quasi-co-located (QCL)-TypeA or QCL-TypeC to target DL TCI state);

[0101] • TssB-proc = 2 ms; and

[0102] • TOk = 1 if target DL TCI state is not in an active TCI state list for PDSCH / PDCCH, 0 otherwise. The target DL TCI state may be considered known when, during the period from the last transmission of the RS resource used for the layer 1 reference signal received power (Ll- RSRP) measurement reporting for the target DL TCI state to the completion of TCI state switch, where the RS resource for Ll-RSRP measurement is the RS in target DL TCI state or QCLed to the target downlink TCI state:

[0103] • The indication to switch TCI state is received within 1280 ms upon the last transmission of the RS resource for beam reporting or measurement;

[0104] • The apparatus has sent at least 1 Ll-RSRP report for the target DL TCI state before the TCI state switch command;

[0105] • The target DL TCI state remains detectable during the DL TCI state switching period;

[0106] • The SSB associated with the target DL TCI state remains detectable during the DL TCI switching period;

[0107] • The signal to noise ratio (SNR) of the DL TCI state > -3dB; and

[0108] • The SSB can be associated with either the serving cell policy control information (PCI) or a PCI different from serving cell PCI.

[0109] Otherwise, the DL TCI state may be considered unknown. When the target DL TCI state is unknown, an additional Ll-RSRP measurement period may be added to the time by which the apparatus is required to be able to receive signalling with the target DL TCI state at the first slot that is after slot: B-proc)) / NR slot length.

[0110] The apparatus may also be required to be able to receive signalling (e.g., dedicated PDCCH / PDSCH) with the old DL TCI state until slot subframe, p n-i- THARQ + 3N slot where:

[0111] • T Li-RSRP = 0 in frequency range (FR) 1 or when the DL TCI state switching not involving QCL-TypeD in FR2. Otherwise,

[0112] • T Li-RSRP is the time for Rx beam refinement in FR2, defined as: o TLi-RSPR_Measurement_Period_ssB for SSB (e.g. as specified in 3GPP TS 38.133 clause 9.5.4.1), o with the assumption of M= I

[0113] O With TReport = 0

[0114] • TLi-RSRP_Measurement_Period_csi-RS for channel state information (CSI) reference signal (RS) (e.g. as specified in 3GPP TS 38.133 clause 9.5.4.2) o CSI-RS based Ll-RSRP measurement only apply for TCI state switch when source RS is associated with serving cell o configured with higher layer parameter repetition set to ON o with the assumption of M= I for periodic CSI-RS o for aperiodic CSI-RS if number of resources in resource set at least equal to MaxNumberRxBeam

[0115] O With TReport = 0

[0116] • TOuk = 1 for CSI-RS based Ll-RSRP measurement, and 0 for SSB based Ll-RSRP measurement when TCI state switching involves QCL-TypeD

[0117] • TOuk = 1 when TCI state switching involves other QCL types only

[0118] • Tfirst-SSB is time to first SSB transmission after Ll-RSRP measurement when TCI state switching involves QCL-TypeD;

[0119] • Tfirst-SSB is time to first SSB transmission after MAC CE command is decoded by the UE for other QCL types;

[0120] • The SSB shall be the QCL-TypeA or QCL-TypeC to target TCI state.

[0121] In some examples when the target TCI state is known for an UL TCI state switch (either separately or jointly with a DL TCI state switch) for a single TRP, upon receiving the indication to switch TCI states in slot n on serving cell, the apparatus may be required to be able to transmit uplink signal with the target TCI state in the slot:

[0122] If the target TCI state is unknown, the apparatus may be required to be able to transmit uplink signal with the target TCI state in the slot:

[0123] The apparatus may also be required to be able to transmit with the old UL TCI state until slot: subframe, n n+ THARQ + 3N slot

[0124] Where,

[0125] • THARQ (in slot) is the timing between DL data transmission and acknowledgement (e.g., as specified in 3GPP TS 38.213).

[0126] • NM = 1 , if the target PL-RS is not maintained by the UE, 0 otherwise.

[0127] In FR2, in case that the target path loss reference signal (PL-RS) associated with or included in the target UL or joint TCI state is SSB, then the requirements may apply when this target PL-RS is maintained by the apparatus. The PL-RS may be considered to be maintained provided that:

[0128] • the target PL-RS is associated with or included in the UL or joint TCI states in the active TCI list for PUSCH / PUCCH / SRS transmissions;

[0129] • there are no more than 4 different RS activated as PL-RS per serving cell among all active UL TCI states (UL or joint TCI state) for PUSCH / PUCCH / SRS transmissions

[0130] • the target pathloss reference signal remains detectable during TCI state switching period

[0131] • SNR of the target pathloss reference signal>-3dB

[0132] • The associated SSBs with the target pathloss reference signal remain detectable during the TCI state switching period. o SNR of the associated SSB >-3dB

[0133] • Tfirst_tar et-PL-RS is time to first pathloss RS transmission after Ll-RSRP measurement when target TCI state is unknown.

[0134] • Tfirst_tar et-PL-RS is time to first pathloss RS transmission after the indication to switch TCI state (e.g., MAC CE command) is decoded by the apparatus for known TCI State.

[0135] • Ttarget_PL-RS is the periodicity of the target pathloss reference signal which would be SSB or NZP CSI-RS when PL-RS is associated with serving cell

[0136] • Ttarget_PL-RS is the periodicity of the target pathloss reference signal which would be SSB when PL-RS is associated with PCI different from serving cell

[0137] • T Li-RSRP is the time for Rx beam refinement in FR2, defined as

[0138] • TLi-RSPR_Measurement_Period_ssB for SSB (e.g., as specified in 3GPP TS 38.213 clause 9.5.4.1 or 9.13.4.1), o with the assumption of M= I

[0139] O With TReport = 0 o TLi-RSRP_Measurement_Period_csi-RS for CSI-RS (e.g., as specified in 3GPP TS 38.213 clause 9.5.4.2)

[0140] ■ CSI-RS based Ll-RSRP measurement only apply for TCI state switch when source RS is associated with serving cell

[0141] ■ configured with higher layer parameter repetition set to ON

[0142] ■ with the assumption of M= I for periodic CSI-RS

[0143] ■ for aperiodic CSI-RS if number of resources in resource set at least equal to MaxNumberRxBeam

[0144] • With TReport = 0.

[0145] In the case of a joint TCI state switch (e.g., an UL TCI state switch and a DL TCI state switch), the apparatus may not be expected to receive on the target DL TCI state and / or transmit on the target UL TCI state until the apparatus completes both the DL and UL TCI state switches.

[0146] In the case of multiple TRPs (e.g. a first TRP and a second TRP), the apparatus may be configured in a single downlink control information (DCI) mode or multi-DCI mode. In the single DCI mode, the apparatus may receive an indication from one of the TRPs indicating a switch of TCI state for the multiple TRPs (e.g., the first TRP sends an indication to switch TCI state for transmissions between the apparatus and the first TRP and to switch TCI state for transmissions between the apparatus and the second TRP). In multi-DCI mode, each of the multiple TRPs may send a separate indication for TCI state switch associated with that TRP. Similarly to the single TRP case explained above, the apparatus may be required to be able to receive and / or transmit using the old TCI and target TCI state(s) within a required time period in the multi-TRP case, both for single DCI mode and multi-DCI mode.

[0147] Thus, in general, the network requires the apparatus to perform TCI state switch within a certain time period from having sent the indication of the switch to the apparatus. In both the single- TRP and multi-TRP cases, the UL TCI state switching and the DL TCI state switching requirements may be different. For example the UL TCI state switching can take longer than the DL TCI state switching.

[0148] The network may be unaware of when the UE has actually completed the TCI state switch. Instead, the network may not expect the apparatus to be able to transmit / receive using the target TCI state until the end of the required time period, while in reality the UE may have executed the TCI state switch earlier. This may result in a time period in which the UE could send / receive data via the target TCI state, but the network does not know this and therefore cannot schedule transmissions accordingly. This may lead to an inefficient system.

[0149] To further illustrate this issue, a summary of example switching times is provided in Table 1 below based on the following assumptions:

[0150] - THARQ = 8 slots,

[0151] - slots,

[0152] Tfirst-SSB, Tfirst_target-PL-RS , Ttarget_PL-RS , TLl-RSPR_Measurement_Period_SSB — 20mS,

[0153] NR_slot_length = 125 ps,

[0154] Table 1 - example time requirements for completing TCI state switch

[0155] According to the example provided in Table 1, in single-TRP with a joint TCI state switch (i.e., the switch of DL TCI state and UL TCI state) even toward known TCI states, if the PL-RS of the target TCI state is not maintained, the time to complete the TCI state switch is 106 ms. This means that the UE cannot be scheduled in the DL for 106 ms after receiving a joint TCI state switch command (i.e. the end of the required time to complete the UL TCI state switch), even though the DL will be ready for reception 4 ms after the UE receives the command.

[0156] Some examples of the present disclosure may address one or more of these issues. Some examples may provide an improved TCI state switching mechanism which may reduce the time in which the UE is not capable of receiving and / or transmitting information, which may increase throughput and improve the efficiency of the network. Reference is made to FIG. 4, which shows methods according to some examples.

[0157] With reference to FIG. 4a, a method is shown that may be performed by a first apparatus. The first apparatus may be a UE, such as UE 100.

[0158] At 400, the method comprises receiving, from at least one TRP, at least one indication to switch at least one TCI state. The at least one indication may be comprised in a MAC CE or DCI.

[0159] The indication may indicate that the first apparatus is to switch an UL TCI state and / or a DL TCI state. For example, the at least one indication may comprise a first indication to switch from a first TCI state to a second TCI state. The at least one indication may further comprise a second indication to switch from a third TCI state to a fourth TCI state.

[0160] In some examples the first indication and second indication may be received from a first TRP in separate indications or in a joint indication. In other examples, the first indication may be received from a first TRP and the second indication may be received from a second TRP different to the first TRP. The first TRP and second TRP may be provided by a same access node or different access nodes.

[0161] In some examples the first TCI state and the second TCI state may be one of an uplink TCI state and a downlink TCI state, and the third TCI state and the fourth TCI state may be the other of the uplink TCI state and the downlink TCI state (e.g., the apparatus may be indicated to switch both UL TCI state and DL TCI state).

[0162] In some examples the first TCI state and the second TCI state may be an uplink TCI state associated with the first TRP and the third TCI state and the fourth TCI state may be an uplink TCI state associated with the second TRP. In other examples the first TCI state and the second TCI state may be a downlink TCI state associated with the first TRP and the third TCI state and the fourth TCI state may be a downlink TCI state associated with the second TRP.

[0163] The TCI state(s) to which the first apparatus is being switched (e.g. the second TCI state and optionally the fourth TCI state) may be either known or unknown, and if known may be associated with a RS which is either maintained or not maintained, for example as described previously. For instance, in some examples the second TCI state and / or the fourth TCI state may be known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth TCI state and the reference signal remains detectable to the first apparatus. In some examples the second TCI state and / or fourth TCI state may be an uplink TCI state and / or a joint DL / UL TCI state that is known to the first apparatus and associated with a PL-RS, where measurements of the PL-RS are maintained or not maintained by the first apparatus.

[0164] At 402, the method comprises, based on the received at least one indication, switching the at least one TCI state. For example, the switching may comprise switching from the first TCI state to the second TCI state. In some examples the switching may further comprise switching from the third TCI state to the fourth TCI state.

[0165] As explained previously, the switching of TCI state may be associated with a required time period within which the switching is to be completed. That is to say, the first apparatus may be required to have completed the TCI state switch by the end of a first required time period. Also as explained previously, the first apparatus may be required to maintain the old TCI state (e.g., first TCI state and third TCI state) for a second required time period. The first required time period and second required time period may be as described previously, or may be determined in a different manner than described previously.

[0166] At 404, the method comprises sending, to the at least one TRP, at least one indication that the first apparatus has switched the at least one TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state. The at least one indication that the first apparatus has switched the at least one TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state may be comprised in a MAC CE or UCI.

[0167] The sending may be performed after completion of switching at least one of the TCI state switch(s) indicated at step 400. This will be described in further detail below with reference to FIGs. 5 to 7. In some examples (e.g. when the first apparatus receives the first indication and second indication from the first TRP, either as separate indications or as a joint indication), the sending may comprise sending the at least one indication that the first apparatus has switched the at least one TCI state to the first TRP.

[0168] In some examples (e.g. when the first apparatus receives the first indication from the first TRP and the second indication from the second TRP), the sending may comprise sending, to the first TRP, a third indication that the first apparatus has switched from the first TCI state to the second TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second TCI state; and sending, to the second TRP, a fourth indication that the first apparatus has switched from the third TCI state to the fourth TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth TCI state.

[0169] With reference to FIG. 4b, a method is shown that may be performed by a second apparatus. The second apparatus may be a first TRP, or an access node comprising the first TRP.

[0170] At 406, the method comprises sending, to a first apparatus, at least one indication to switch at least one TCI state. The at least one indication may be as described previously with respect to FIG. 4a.

[0171] In some examples the second apparatus may comprise a plurality of TRPs comprising at least a first TRP and a second TRP. Sending the at least one indication to switch the at least one TCI state may comprise sending the first indication to the first apparatus via the first TRP and the second indication to the first apparatus via the second TRP. While some examples are described herein with respect to a first TRP and a second TRP, it should be understood that the concepts described herein may be extended to include any number of TRPs.

[0172] The first TCI state and the second TCI state may be an uplink TCI state associated with the first TRP and the third TCI state and the fourth TCI state may be an uplink TCI state associated with the second TRP. Alternatively the first TCI state and the second TCI state may be a downlink TCI state associated with the first TRP and the third TCI state and the fourth TCI state may be a downlink TCI state associated with the second TRP. At 408, the method comprises receiving, from the first apparatus, at least one indication that the first apparatus has switched the at least one TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state.

[0173] In some examples receiving the at least one indication that the first apparatus has switched the at least one TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state may comprise: receiving, from the first apparatus via the first TRP, a third indication that the first apparatus has switched from the first TCI state to the second TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second TCI state; and receiving, from the first apparatus via the second TRP, a fourth indication that the first apparatus has switched from the third TCI state to the fourth TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth TCI state.

[0174] At 410, the method comprises scheduling one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state.

[0175] Thus after completion of the method described in FIG. 4a and 4b, the first apparatus and second apparatus may begin to communicate based on the switched TCI state (e.g. the second TCI state and / or the fourth TCI state). For example, the first apparatus may send one or more UL transmissions to the second apparatus based on the switched TCI state, and / or receive one or more DL transmissions from the second apparatus based on the switched TCI state. Advantageously, the indication that the first apparatus has completed the TCI state(s) switch may be sent before expiry of the required time period(s) described previously. This may allow for the communication based on the switched TCI states to occur sooner than is possible according to some existing methods.

[0176] For instance, returning to the example provided previously in relation to Table 1, in single-TRP with a joint TCI state switch (i.e., the switch of DL TCI state and UL TCI state) toward known TCI states, if the PL-RS of the target TCI state is not maintained, the time to complete the UL TCI state switch is 106 ms. By applying the methods described above in relation to FIG. 4, in some examples the first apparatus may complete the DL TCI state switch after 4 ms and may indicate such completion to the second apparatus. The second apparatus may then schedule DL transmissions to the first apparatus using the target TCI state immediately or shortly after 4 ms, rather than having to wait for the full 106 ms.

[0177] Likewise, if the first apparatus completes the UL TCI state switch within 70 ms, the first apparatus may indicate such completion to the second apparatus. The first apparatus may then send UL transmissions to the second apparatus immediately or shortly after 70 ms, rather than having to wait for the full 106 ms.

[0178] In some examples the first apparatus may send, to the second apparatus, information indicating the first apparatus’ capability for performing transmission and / or reception using a TCI state from before the TCI state switch for longer than a required time; and / or performing transmission and / or reception using a TCI state from after the TCI state switch earlier than a required time.

[0179] For example, the first apparatus may indicate that it is capable of receiving using the first TCI state for longer than the required time, and may be capable of transmitting using the third TCI state for longer than the required time. The required time may be as described previously.

[0180] The second apparatus may send the at least one indication at 406 (and likewise the first apparatus may receive the at least one indication at 400) and / or receive the at least one indication at 408 (and likewise the first apparatus may send the at least one indication at 404) based at least in part on the indicated first apparatus’ capability.

[0181] For example, if the first apparatus is capable to transmit with the old UL TCI state for longer time than the requirements, in case of both DL and UL switches with the DL completing before the UL, the first apparatus may be capable to inform the second apparatus about the DL switch completion immediately after such DL switch completion by transmitting with the old UL TCI state. As explained previously, the sending may be performed after completion of switching at least one of the TCI state switch(s) indicated at step 400. FIGs. 5 to 7 illustrate examples of different conditions on which the sending may be based.

[0182] FIG. 5 illustrates two examples where the sending step 404 is performed after completion of every TCI state switch.

[0183] In FIG. 5a, a joint TCI swich indication is received from the second apparatus (i.e., a DL and UL TCI state switch is indicated in a joint indication) at 500. After completing the DL TCI state switch at 502 a first indication is sent to the second apparatus, and after completing the UL TCI state switch at 504 a second indication is sent to the second apparatus.

[0184] In FIG. 5b, separate TCI swich indications are received from the second apparatus - a DL TCI state switch is indicated in a first indication at 506 and an UL TCI state switch is indicated in a second indication at 508. After completing the DL TCI state switch at 510 a first indication is sent to the second apparatus, and after completing the UL TCI state switch at 512 a second indication is sent to the second apparatus.

[0185] FIG. 6 illustrates four examples where the sending step 404 is performed after completion of the last TCI state switch. Advantageously, when compared to the examples of FIG. 5, the examples of FIG. 6 may reduce signalling overhead while still providing benefits of informing the second apparatus when both switches have been completed to enable faster UL / DL scheduling after TCI state switching (as described previously, in some examples the first apparatus may not be expected to receive on DL (or transmit on UL) based on the target TCI state before completing both DL and UL TCI state switches).

[0186] In FIG. 6a, a joint TCI swich indication is received from the second apparatus (i.e., a DL and UL TCI state switch is indicated in a joint indication) at 600. The DL TCI state switch is completed at 602 and the UL TCI state switch is completed at 604. The indication is sent to the second apparatus after completing the last TCI state switch, which in FIG. 6a occurs after completion of the UL TCI state switch at 604.

[0187] In FIG. 6b, separate TCI swich indications are received from the second apparatus - a DL TCI state switch is indicated in a first indication at 606 and an UL TCI state switch is indicated in a second indication at 608. Here it is assumed that the UL TCI state switch takes longer than the DL TCI state switch. The DL TCI state switch is completed at 610 and the UL TCI state switch is completed at 612. The indication is sent to the second apparatus after completing the last TCI state switch, which in FIG. 6b occurs after completion of the UL TCI state switch at 612.

[0188] In FIG. 6c, separate TCI swich indications are received from the second apparatus - an UL TCI state switch is indicated in a first indication at 614 and a DL TCI state switch is indicated in a second indication at 616. Here it is assumed that the UL TCI state switch takes longer than the DL TCI state switch, however due to the arrival times of the indications the DL TCI state switch finishes last. The UL TCI state switch is completed at 618 and the DL TCI state switch is completed at 620. The indication is sent to the second apparatus after completing the last TCI state switch, which in FIG. 6c occurs after completion of the DL TCI state switch at 620.

[0189] In FIG. 6d, separate TCI swich indications are received from the second apparatus - a DL TCI state switch is indicated in a first indication at 622 and an UL TCI state switch is indicated in a second indication at 624. Here it is assumed that the DL TCI state switch takes longer than the UL TCI state switch. The UL TCI state switch is completed at 626 and the DL TCI state switch is completed at 628. The indication is sent to the second apparatus after completing the last TCI state switch, which in FIG. 6d occurs after completion of the DL TCI state switch at 628.

[0190] FIG. 7 illustrates four examples where the sending step 404 is performed after completion of the UL TCI state switch but not the DL TCI state switch. The examples of FIG. 7 may exploit the fact that UL switches take on average longer than DL switches, and so the first apparatus may send signalling to the second apparatus after completion of only an UL TCI switch. However in some cases the DL TCI state switch may be completed after the UL TCI state switch. To address this, in the case of separate TCI states, some restriction on a maximum delay between two overlapping TCI switches may be introduced, as depicted by the delay in FIG. 7d.

[0191] In FIG. 7a, a joint TCI swich indication is received from the second apparatus (i.e., a DL and UL TCI state switch is indicated in a joint indication) at 700. The DL TCI state switch is completed at 702 and the UL TCI state switch is completed at 704. The indication is sent to the second apparatus after completing the UL TCI state switch at 704. In FIG. 7b, separate TCI swich indications are received from the second apparatus - a DL TCI state switch is indicated in a first indication at 706 and an UL TCI state switch is indicated in a second indication at 708. The DL TCI state switch is completed at 710 and the UL TCI state switch is completed at 712. The indication is sent to the second apparatus after completing the UL TCI state switch at 712.

[0192] In FIG. 7c, separate TCI swich indications are received from the second apparatus - an UL TCI state switch is indicated in a first indication at 714 and a DL TCI state switch is indicated in a second indication at 716. The DL TCI state switch is completed at 718 and the UL TCI state switch is completed at 720. The indication is sent to the second apparatus after completing the UL TCI state switch at 720.

[0193] In FIG. 7d, separate TCI swich indications are received from the second apparatus - an UL TCI state switch is indicated in a first indication at 722 and a DL TCI state switch is indicated in a second indication (after a delay restriction) at 724. The UL TCI state switch and DL TCI state switch are both completed at 726. The indication is sent to the second apparatus after completing the UL TCI state switch at 726.

[0194] It should be understood that the examples shown in FIG. 7 may be adapted to apply for the case when the sending step 404 is performed after completion of the DL TCI state switch but not the UL TCI state switch by swapping the UL and DL labels on the TCI state switch commands and switching operations.

[0195] Reference is made to FIG. 8, which shows a signalling exchange according to some examples in a single TRP scenario.

[0196] In the example of FIG. 8 a UE (which may for example correspond to the first apparatus described previously) is in communication with a single TRP (which may for example correspond to the second apparatus described previously). It is further assumed that initially the UE is configured with an initial DL TCI state for DL transmissions from the TRP (which may correspond to the first TCI state described previously) and an initial UL TCI state for UL transmissions to the TRP (which may correspond to the third TCI state described previously). Optionally at 800 the UE may indicate, to the TRP, the UE’s capability for performing transmission and / or reception using a TCI state from before the TCI state switch for longer than a required time; and / or performing transmission and / or reception using a TCI state from after the TCI state switch earlier than a required time.

[0197] Optionally at 802, based on the indication at 800 the TRP may indicate to the UE (e.g. via RRC signalling), the conditions under which the UE is to report TCI state switch completion - for example by defining one or more of the conditions illustrated in FIGs. 5 to 7 (i.e. after completion of each TCI state switch; after completion of a last TCI state switch; after completion of an uplink TCI state switch; or after completion of a downlink TCI state switch). In the example of FIG. 8 it is assumed that the UE is indicated to report TCI state swich completion after completion of each TCI state switch.

[0198] At 804, the UE and TRP exchange UL and DL signalling based on the first TCI state and the third TCI state.

[0199] At 806a the TRP sends a first indication to the UE to switch from the first TCI state to the second TCI state, and at 806b the TRP sends a second indication to the UE to switch from the third TCI state to the fourth TCI state. As described previously, the first and second indications may be separate indications or a joint indication.

[0200] At 808, the UE switches from the first TCI state to the second TCI state.

[0201] At 810, upon completion of the TCI state switch from the first TCI state to the second TCI state, the UE sends an indication to the TRP that the UE has switched to the second TCI state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state. The indication may be comprised in a MAC CE or UCI.

[0202] At 812, the UE may receive DL signalling from the TRP based on the second TCI state. At this stage the UE has not switched the UL TCI state, and may at 812 still send UL signalling to the TRP based on the third TCI state. In some examples the UE may send the indication at 810 based on the third TCI state.

[0203] At 814 the UE switches from the third TCI state to the fourth TCI state. At 816 upon completion of the TCI state switch from the third TCI state to the fourth TCI state, the UE sends an indication to the TRP that the UE has switched to the fourth TCI state. The indication may be comprised in a MAC CE or UCI.

[0204] At 818, the UE may receive DL signalling from the TRP based on the second TCI state and send UL signalling to the TRP based on the fourth TCI state. As described previously, this may occur before the required time period for TCI state switching as specified in current 3GPP specifications.

[0205] Reference is made to FIG. 9, which shows a signalling exchange according to some examples in a multi-TRP scenario.

[0206] In the example of FIG. 9 a UE (which may for example correspond to the first apparatus described previously) is in communication with a first TRP (which may for example correspond to the second apparatus described previously) and a second TRP. As explained previously, the first and second TRPs may be provided by a same access node or different access nodes.

[0207] It is further assumed that initially the UE is configured with an initial DL TCI state for receiving transmissions from each TRP - that is to say the UE is configured with a first TCI state for receiving DL transmissions from the first TRP and a third TCI state for receiving transmissions from the second TRP.

[0208] Optionally at 900 the UE may indicate, to the first TRP and second TRP, the UE’s capability for performing transmission and / or reception using a TCI state from before the TCI state switch for longer than a required time; and / or performing transmission and / or reception using a TCI state from after the TCI state switch earlier than a required time.

[0209] Optionally at 902, based on the indication at 900 the first TRP and / or the second TRP may indicate to the UE (e.g. via RRC signalling), the conditions under which the UE is to report TCI state switch completion - for example by defining one or more of the conditions illustrated in FIGs. 5 to 7 (i.e. after completion of each TCI state switch; after completion of a last TCI state switch; after completion of an uplink TCI state switch; or after completion of a downlink TCI state switch). In the example of FIG. 9 it is assumed that the UE is indicated to report TCI state swich completion after completion of each TCI state switch.

[0210] At 904, the UE receives DL signalling from the first TRP based on the first TCI state and from the second TRP based on the third TCI state.

[0211] At 906a the first TRP sends a first indication to the UE to switch from the first TCI state to the second TCI state and a second indication to the UE to switch from the third TCI state to the fourth TCI state. As described previously, the first and second indications may be separate indications or a joint indication.

[0212] Alternatively at 906b the first TRP sends a first indication to the UE to switch from the first TCI state to the second TCI state, and the second TRP sends a second indication to the UE to switch from the third TCI state to the fourth TCI state.

[0213] Step 906a may apply in the case of single-DCI (sDCI), where a single TRP sends DO relating to both TRPs, while step 906b may apply in the case of multi-DCI, where each TRP sends it’s own DCI.

[0214] At 908, the UE determines what order to perform the TCI state switches in. In the example of FIG. 9, it is assumed that the UE determines to perform the switch from the first TCI state to the second TCI state before performing the switch from the third TCI state to the fourth TCI state.

[0215] How the UE determines what order to perform the TCI state switches in may be implementation specific. For example, the UE may determine the order based on one or more of the following:

[0216] • Which indication to switch TCI state was received first or last;

[0217] • A lowest / highest / specific index associated with the TRPs (e.g., corsetpoolindex) - e.g., the UE may perform the TCI state switch associated with the highest corsetpoolindex first;

[0218] • A link quality (e.g., in terms of RSRP) associated with each TRP - e.g., prioritizing a TCI state switch for the TRP with the worst link quality (to try to avoid losing that link), or prioritizing a TCI state switch for the TRP with the better link quality (to try to ensure at least one link is not lost).

[0219] It should be understood that in some examples the UE may take other criteria into account when determining what order to perform the TCI state switches in at step 908.

[0220] At 910, the UE switches from the first TCI state to the second TCI state.

[0221] At 912, upon completion of the TCI state switch from the first TCI state to the second TCI state, the UE sends an indication to the first TRP and the second TRP that the UE has switched to the second TCI state. The indication may be comprised in a MAC CE or UCI.

[0222] At 914, the UE may receive DL signalling from the first TRP based on the second TCI state. At this stage the UE has not switched the DL TCI state associated with the second TRP (i.e. the third TCI state), and may at 914 also receive DL signalling from the second TRP based on the third TCI state.

[0223] At 916 the UE switches from the third TCI state to the fourth TCI state.

[0224] At 918 upon completion of the TCI state switch from the third TCI state to the fourth TCI state, the UE sends an indication to the first TRP and the second TRP that the UE has switched to the fourth TCI state. The indication may be comprised in a MAC CE or UCI.

[0225] At 920, the UE may receive DL signalling from the first TRP based on the second TCI state and receive DL signalling from the second TRP based on the fourth TCI state. As described previously, this may occur before the required time period for TCI state switching as specified in current 3GPP specifications.

[0226] While the example of FIG. 9 is applied to a multi-TRP scenario with a DL TCI state switch, it should be understood that examples of the present disclosure may applied in a similar manner to a multi-TRP scenario with an UL TCI state switch.

[0227] Examples have been described whereby a first apparatus, such as a UE, may inform a second apparatus, such as a TRP of a network, when a TCI state switch has been completed. This may allow the second apparatus to schedule UL / DL transmissions between the first apparatus and second apparatus sooner after triggering the TCI state switch, which may increase the throughput of the network and thereby improve the efficiency of the network.

[0228] In some examples there is provided a first apparatus comprising means for: receiving, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switching the at least one transmission configuration indicator state; and sending, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state.

[0229] In some examples there is provided a second apparatus comprising means for: sending, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receiving, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state; and scheduling one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state.

[0230] In some examples there is provided a first apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switch the at least one transmission configuration indicator state; and send, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state.

[0231] In some examples there is provided a second apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: send, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receive, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state; and schedule one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one TCI state.

[0232] FIG. 10 shows a schematic representation of non-volatile memory media 1000a (e.g., computer disc (CD) or digital versatile disc (DVD)) and 1000b (e.g. universal serial bus (USB) memory stick) storing instructions and / or parameters 1002 which when executed by a processor allow the processor to perform one or more of the steps of the method of FIG. 4.

[0233] It is understood that references in the above to various network functions (e.g., to an AMF, an SMF, TNF etc.) may be implemented by apparatus that perform at least some of the functionality associated with those network functions. Further, an apparatus configured to implement a network function may further be configured to implement a virtual network function instance of that network function.

[0234] It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and / or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

[0235] It is noted that whilst some example embodiments have been described in relation to 5G networks, similar example embodiments can be applied in relation to other networks and communication systems. Therefore, although certain example embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, further example embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein. It is also noted herein that there are several variations and modifications which may be made to the various example embodiments described herein without departing from the scope of this disclosure.

[0236] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements. As used herein, the expression “and / or” includes any and all combinations of the listed terms, including at least any one of the elements, at least any two or more of the elements, or at least all of the elements.

[0237] As used herein, the term “or” refers to a non-exclusive “or” unless otherwise indicated (e.g., use of “or else” or “or in the alternative”).

[0238] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included. Analogously, performing a step or functionality “based on A” does not indicate that the step or functionality is performed solely based on “A” as one or more additional conditions may be included.

[0239] In general, the various embodiments may be implemented in hardware or special purpose circuitry, software, logic or any combination thereof. Some aspects of the disclosure may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting and illustrative examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0240] As used herein, the term “circuitry” may refer to one or more or all of the following:

[0241] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable):

[0242] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0243] (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[0244] (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that utilizes software (e.g., firmware) for operation, but the software may not be present when it is not utilized for operation.”

[0245] This definition of circuitry applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0246] The embodiments of this disclosure may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and / or macros, may be stored in any apparatus- readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

[0247] Further in this regard it should be noted that any blocks of the logic flow as in the FIGs. may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media, such as hard disk or floppy disks, and optical media, such as DVD and the data variants thereof, CD. The physical media is a non-transitory media. The term “non-transitory,” as used herein, is a limitation of the medium itself (e.g., tangible, not a signal ) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0248] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

[0249] Various example embodiments of the disclosure may be practiced in various components, such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0250] The scope of protection sought for various example embodiments of the disclosure is set out by the independent claims. The example embodiments and features thereof, if any, described in this disclosure that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various example embodiments of the disclosure.

[0251] The foregoing description has provided, by way of non-limiting and illustrative examples, a full and informative description of the various example embodiments of this disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of this disclosure, when read in conjunction with the drawings and the claims. However, all such and similar modifications of the teachings will still fall within the various example embodiments of this disclosure. By way of non-limiting and illustrative example, there is a further example embodiment comprising a combination of one or more example embodiments with any of the other example embodiments previously discussed.

Claims

CLAIMS1. A first apparatus comprising means for: receiving, from at least one transmission reception point, at least one indication to switch at least one transmission configuration indicator state; based on the received at least one indication, switching the at least one transmission configuration indicator state; and sending, to the at least one transmission reception point, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

2. The first apparatus of claim 1, wherein the at least one indication comprises a first indication to switch from a first transmission configuration indicator state to a second transmission configuration indicator state, and wherein the switching comprises switching from the first transmission configuration indicator state to the second transmission configuration indicator state.

3. The first apparatus of claim 2, wherein the at least one indication further comprises a second indication to switch from a third transmission configuration indicator state to a fourth transmission configuration indicator state, and wherein the switching further comprises switching from the third transmission configuration indicator state to the fourth transmission configuration indicator state.

4. The first apparatus of claim 3, wherein: the first and second indication are received from a first transmission reception point in separate indications; the first and second indication are received from the first transmission reception point in a joint indication; or the first indication is received from a first transmission reception point and the second indication is received from a second transmission reception point.

5. The first apparatus of claim 4, wherein the first and second indication are received from the first transmission reception point in the separate indications or in the joint indication, and wherein the first transmission configuration indicator state and the second transmission configuration indicator state are one of an uplink transmission configuration indicator state state and a downlink transmission configuration indicator state, and wherein the third transmission configuration indicator state and the fourth transmission configuration indicator state are the other of the uplink transmission configuration indicator state and the downlink transmission configuration indicator state.

6. The first apparatus of claim 4, wherein the first indication is received from the first transmission reception point and the second indication is received from the second transmission reception point, and wherein: the first transmission configuration indicator state and the second transmission configuration indicator state are an uplink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state are an uplink transmission configuration indicator state associated with the second transmission reception point; or the first transmission configuration indicator state and the second transmission configuration indicator state are a downlink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state are a downlink transmission configuration indicator state associated with the second transmission reception point.

7. The first apparatus of claim 6, wherein sending, to the at least one transmission reception point, the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state comprises: sending, to the first transmission reception point, a third indication that the first apparatus has switched from the first transmission configuration indicator state to the second transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second transmission configuration indicator state; and sending, to the second transmission reception point, a fourth indication that the first apparatus has switched from the third transmission configuration indicator state to the fourthtransmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth transmission configuration indicator state.

8. The first apparatus of any of claims 3 to 7, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state are known to the first apparatus or unknown to the first apparatus, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state are known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth transmission configuration indicator state and the reference signal remains detectable to the first apparatus.

9. The first apparatus of claim 8, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state are an uplink transmission configuration indicator state and / or a joint downlink / uplink transmission configuration indicator state that is known to the first apparatus and are associated with a path loss reference signal, and wherein measurements of the path loss reference signal are either maintained or are not maintained by the first apparatus.

10. The first apparatus of any preceding claim, wherein switching the at least one transmission configuration indicator state is associated with a required time period within which the switching is to be completed.

11. The first apparatus of claim 10, wherein sending the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state is performed before expiry of the required time period.

12. The first apparatus of any preceding claim, wherein the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on theswitched at least one transmission configuration indicator state is comprised in a medium access control control element or uplink control information.

13. The first apparatus of any preceding claim, wherein sending the at least one indication comprises: sending the at least one indication after completion of each of the at least one transmission configuration indicator state switch; sending the at least one indication after completion of a last of the at least one transmission configuration indicator state switch; sending the at least one indication after completion of an uplink transmission configuration indicator state switch; or sending the at least one indication after completion of a downlink transmission configuration indicator state switch.

14. The first apparatus of any preceding claim, wherein the means is further for: sending, to the at least one transmission reception point, information indicating the first apparatus’ capability for either: performing transmission and / or reception using a transmission configuration indicator state from before the transmission configuration indicator state switch for longer than a required time; and / or performing transmission and / or reception using a transmission configuration indicator state from after the transmission configuration indicator state switch earlier than a required time.

15. The first apparatus of claim 14, wherein the at least one indication to switch the at least one transmission configuration indicator state is based at least in part on the information indicating the first apparatus’ capability for performing transmission and / or reception using the transmission configuration indicator state from before the transmission configuration indicator state switch for longer than the required time; and / or performing transmission and / or reception using the transmission configuration indicator state from after the transmission configuration indicator state switch earlier than the required time16. The first apparatus of any preceding claim, wherein the means is further for:sending one or more uplink transmissions to the at least one transmission reception point based on the switched at least one transmission configuration indicator state; and / or receiving one or more downlink transmissions from the at least one transmission reception point based on the switched at least one transmission configuration indicator state.

17. A second apparatus comprising means for: sending, to a first apparatus, at least one indication to switch at least one transmission configuration indicator state; receiving, from the first apparatus, at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state; and scheduling one or more uplink and / or downlink transmissions for the first apparatus based on the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state.

18. The second apparatus of claim 17, wherein the at least one indication comprises a first indication to switch from a first transmission configuration indicator state to a second transmission configuration indicator state.

19. The second apparatus of claim 18, wherein the at least one indication further comprises a second indication to switch from a third transmission configuration indicator state to a fourth transmission configuration indicator state.

20. The second apparatus of claim 19, wherein: the first and second indication are sent to the first apparatus in separate indications; or the first and second indication are sent to the first apparatus in a joint indication.

21. The second apparatus of claim 20, wherein the first transmission configuration indicator state and the second transmission configuration indicator state are one of an uplink transmission configuration indicator state and a downlink transmission configuration indicator state, and wherein the third transmission configuration indicator state and the fourth transmissionconfiguration indicator state are the other of the uplink transmission configuration indicator state and the downlink transmission configuration indicator state.

22. The second apparatus of claim 19, wherein: the second apparatus comprises a plurality of transmission reception points comprising at least a first transmission reception point and a second transmission reception point; and sending the at least one indication to switch the at least one transmission configuration indicator state comprises sending the first indication to the first apparatus via the first transmission reception point and the second indication to the first apparatus via the second transmission reception point.

23. The second apparatus of claim 22, wherein: the first transmission configuration indicator state and the second transmission configuration indicator state are an uplink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state are an uplink transmission configuration indicator state associated with the second transmission reception point; or the first transmission configuration indicator state and the second transmission configuration indicator state are a downlink transmission configuration indicator state associated with the first transmission reception point and the third transmission configuration indicator state and the fourth transmission configuration indicator state are a downlink transmission configuration indicator state associated with the second transmission reception point.

24. The second apparatus of claim 23, wherein receiving the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state comprises: receiving, from the first apparatus via the first transmission reception point, a third indication that the first apparatus has switched from the first transmission configuration indicator state to the second transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the second transmission configuration indicator state; andreceiving, from the first apparatus via the second transmission reception point, a fourth indication that the first apparatus has switched from the third transmission configuration indicator state to the fourth transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the fourth transmission configuration indicator state.

25. The second apparatus of any of claims 19 to 24, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state are known to the first apparatus or unknown to the first apparatus, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state are known when the first apparatus has reported, to the second apparatus, one or more measurements of a reference signal that is associated with the second and / or fourth transmission configuration indicator state and the reference signal remains detectable to the first apparatus.

26. The second apparatus of claim 25, wherein the second transmission configuration indicator state and / or the fourth transmission configuration indicator state are an uplink transmission configuration indicator state and / or a joint downlink / uplink transmission configuration indicator state that is known to the first apparatus and are associated with a path loss reference signal, and wherein measurements of the path loss reference signal are either maintained or are not maintained by the first apparatus.

27. The second apparatus of any of claims 17 to 26, wherein switching the at least one transmission configuration indicator state is associated with a required time period within which the switching is to be completed.

28. The second apparatus of claim 27, wherein the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state and is available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state is received before expiry of the required time period.

29. The second apparatus of any of claims 17 to 28, wherein the at least one indication that the first apparatus has switched the at least one transmission configuration indicator state andis available to be scheduled for one or more uplink and / or downlink transmissions based on the switched at least one transmission configuration indicator state is comprised in a medium access control element or uplink control information.

30. The second apparatus of any of claims 17 to 29, wherein the means is further for: receiving, from the first apparatus, information indicating the first apparatus’s capability for either: performing transmission and / or reception using a transmission configuration indicator state from before the transmission configuration indicator state switch for longer than a required time; and / or performing transmission and / or reception using a transmission configuration indicator state from after the transmission configuration indicator state switch earlier than a required time.

31. The second apparatus of claim 30, wherein the at least one indication to switch the at least one transmission configuration indicator state is based at least in part on the information indicating the first apparatus’s capability for performing transmission and / or reception using the transmission configuration indicator state from before the transmission configuration indicator state switch for longer than the required time; and / or performing transmission and / or reception using the transmission configuration indicator state from after the transmission configuration indicator state switch earlier than the required time.

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