WO2023160803A1

WO2023160803A1 - Method and apparatus related to inter-cell beam management

Info

Publication number: WO2023160803A1
Application number: PCT/EP2022/054785
Authority: WO
Inventors: Srinivasan Selvaganapathy; Subramanya CHANDRASHEKAR; Tero Henttonen
Original assignee: Nokia Technologies Oy
Priority date: 2022-02-25
Filing date: 2022-02-25
Publication date: 2023-08-31

Abstract

A technique, comprising: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

Description

METHOD AND APPARATUS RELATED TO INTER-CELL BEAM MANAGEMENT

TECHNICAL FIELD

The present disclosure relates to apparatus, a method, and a computer program, and in particular, but not exclusively to apparatus, methods and computer programs related to inter-cell beam management.

BACKGROUND

Inter-cell beam management may involve making transmissions to a user equipment using beams of two or more cells without a change of serving cell for the user equipment.

SUMMARY

A method, comprising: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions . In the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit may trigger the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit may trigger the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

The message indicating a change in system information may indicate a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions and/or may configure the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

The method may further comprise: after newly acquiring system information, transmitting a message for the distributed unit triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

The message triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may comprise a report of beam measurements at the user equipment.

The serving cell may be operated by a first transmission-reception point, and the one or more other cells may comprise one or more cells operated at the first transmissionreception point, and/or one or more cells operated at one or more other transmissionreception points. The command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may comprise a medium access control command actuating a transmission configuration indicator state change at the user equipment.

A method, comprising: receiving at a distributed unit of an access network a message from a user equipment configured for inter cell beam management operation, indicating results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

In the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit may trigger the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit may trigger the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

The method may further comprise: in response to the message from the user equipment, temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; wherein the temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions is continued for a time period ending with the expiry of a timer at the distributed unit or ending upon receiving at the distributed unit a message from the user equipment triggering the distributed unit to end temporary suspension of temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions. The message triggering the distributed unit to end temporary suspension of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may comprise a layer 1 report of beam measurements at the user equipment.

The serving cell may be operated by a first transmission-reception point, and the one or more other cells may comprise one or more cells operated at the first transmissionreception point, and/or one or more cells operated at one or more other transmissionreception points.

The command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may comprise a medium access control command actuating a transmission configuration indicator state change at the user equipment.

A method comprising: sending to a distributed unit of a radio access network from a central unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

A method comprising: transmitting from a user equipment configured for inter-cell beam management operation a report for a distributed unit of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving at the user equipment a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

The search space may be a search space specific to the user equipment; and monitoring the search space may comprise monitoring the search space for a control transmission decodable at the user equipment using an identifier not specific to the user equipment. The search space may be a search space provided for system information reception during inter cell beam management operation.

The method may further comprise: in response to receiving via the search space a control transmission indicating radio resources for transmission of system information for the serving cell, switching to the serving cell for reception of system information of the serving cell.

A method comprising: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

The search space may be specific to the user equipment, and the control transmission may be decodable at the user equipment using an identifier not specific to the user equipment.

The method may further comprise: determining to make within the search space a control transmission decodable at the user equipment using an identifier specific to the user equipment.

The method may further comprise determining to make, via the cell other than the serving cell, within one or more other search spaces specific to one or more other user equipments, one or more other control transmissions indicating the same radio resources for transmission of system information for the serving cell.

User equipment, comprising: means for transmitting an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; means for receiving a message indicating a change in system information; and means for transmitting a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions . In the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit may trigger the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit may trigger the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

The user equipment may further comprise: means for, after newly acquiring system information, transmitting a message for the distributed unit triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A distributed unit, comprising: means for receiving a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and means for receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

The distributed unit may further comprise: means for, in response to the message from the user equipment, temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; wherein the temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may be continued for a time period ending with the expiry of a timer at the distributed unit or ending upon receiving at the distributed unit a message from the user equipment triggering the distributed unit to end temporary suspension of temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions. The message triggering the distributed unit to end temporary suspension of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may comprise a layer 1 report of beam measurements at the user equipment.

A central unit of a radio access network, comprising: means for sending to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

A user equipment comprising: means for transmitting an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; means for receiving at the user equipment a message indicating a change in system information; and means for monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

The search space may be a search space specific to the user equipment; and the means for monitoring the search space may comprise means for monitoring the search space for a control transmission decodable at the user equipment using an identifier not specific to the user equipment.

The search space may be a search space provided for system information reception during inter cell beam management operation.

The user equipment may further comprise: means for, in response to receiving via the search space a control transmission indicating radio resources for transmission of system information for the serving cell, switching to the serving cell for reception of system information of the serving cell.

A distributed unit comprising: means for determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

The distributed unit may further comprise: means for determining to make within the search space a control transmission decodable at the user equipment using an identifier specific to the user equipment.

The distributed unit may further comprise: means for determining to make, via the cell other than the serving cell, within one or more other search spaces specific to one or more other user equipments, one or more other control transmissions indicating the same radio resources for transmission of system information for the serving cell.

User equipment comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the user equipment to perform: transmitting an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving a message indicating a change in system information; and transmitting a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

The message indicating a change in system information may indicate a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

The at least one memory and computer program code may be configured to, with the at least one processor, cause the user equipment to: after newly acquiring system information, transmit a message for the distributed unit triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

The serving cell may be operated by a first transmission-reception point, and the one or more other cells may comprise one or more cells operated at the first transmission- reception point, and/or one or more cells operated at one or more other transmissionreception points.

A distributed unit of an access network, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the distributed unit to perform: receiving a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

The at least one memory and computer program code may be configured to, with the at least one processor, cause the distributed unit to: in response to the message from the user equipment, temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; wherein the temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may be continued for a time period ending with the expiry of a timer at the distributed unit or ending upon receiving at the distributed unit a message from the user equipment triggering the distributed unit to end temporary suspension of temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

The message triggering the distributed unit to end temporary suspension of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions may comprise a layer 1 report of beam measurements at the user equipment.

A central unit of a radio access network, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the central unit to perform: sending to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information

A user equipment comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the user equipment to perform: transmitting an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

The search space may be a search space specific to the user equipment; and the at least one memory and computer program code may be configured to, with the at least one processor, cause the user equipment to monitor the search space for a control transmission decodable at the user equipment using an identifier not specific to the user equipment.

The at least one memory and computer program code may be configured to, with the at least one processor, cause the user equipment to: in response to receiving via the search space a control transmission indicating radio resources for transmission of system information for the serving cell, switch to the serving cell for reception of system information of the serving cell.

A distributed unit a radio access network, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the distributed unit to perform: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

The at least one memory and computer program code may be configured to, with the at least one processor, cause the distributed unit to: determine to make within the search space a control transmission decodable at the user equipment using an identifier specific to the user equipment.

The at least one memory and computer program code may be configured to, with the at least one processor, cause the apparatus to: determine to make, via the cell other than the serving cell, within one or more other search spaces specific to one or more other user equipments, one or more other control transmissions indicating the same radio resources for transmission of system information for the serving cell.

User equipment, comprising: transmitting circuitry for transmitting an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving circuitry for receiving a message indicating a change in system information; and transmitting circuitry for transmitting a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A distributed unit of an access network, comprising: receiving circuitry for receiving a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving circuitry for receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A central unit of a radio access network, comprising: sending circuitry for sending to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

User equipment comprising: transmitting circuitry for transmitting an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving circuitry for receiving a message indicating a change in system information; and monitoring circuitry for monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

A distributed unit a radio access network, comprising: determining circuitry for determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

A computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A computer readable medium comprising program instructions stored thereon for performing: receiving at a distributed unit of an access network a message from a user equipment configured for inter cell beam management operation, indicating results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A computer readable medium comprising program instructions stored thereon for performing: sending to a distributed unit of a radio access network from a central unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

A computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter-cell beam management operation a report for a distributed unit of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving at the user equipment a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

A computer readable medium comprising program instructions stored thereon for performing: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

A non-transitory computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A non-transitory computer readable medium comprising program instructions stored thereon for performing: receiving at a distributed unit of an access network a message from a user equipment configured for inter cell beam management operation, indicating results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A non-transitory computer readable medium comprising program instructions stored thereon for performing: sending to a distributed unit of a radio access network from a central unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

A non-transitory computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter-cell beam management operation a report for a distributed unit of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving at the user equipment a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell. A non-transitory computer readable medium comprising program instructions stored thereon for performing: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

A computer program comprising computer executable code which when run on at least one processor is configured to cause a user equipment at least to: transmit an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receive a message indicating a change in system information; and transmit a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A computer program comprising computer executable code which when run on at least one processor is configured to cause a distributed unit of a radio access network at least to: receive a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receive a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

A computer program comprising computer executable code which when run on at least one processor is configured to cause a central unit of a radio access network at least to: send to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

A computer program comprising computer executable code which when run on at least one processor is configured to cause a user equipment at least to: transmit an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receive a message indicating a change in system information; and monitor a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

A computer program comprising computer executable code which when run on at least one processor is configured to cause a distributed unit of a radio access network at least to: determine to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

In the above, many different aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above.

Various other aspects are also described in the following detailed description and in the attached claims.

BRIEF DESCRIPTION OF THE FIGURES

Some example embodiments will now be described in further detail, by way of example only, with reference to the following examples and accompanying drawings, in which:

Figure 1 shows an example system to which embodiments may be applied; Figure 2 shows a representation of an example of operating a plurality of beams for the same cell;

Figure 3 shows a representation of an example of inter-cell beam management using beams of two cells as candidate resources for transmissions to the user equipment, without a change of serving cell for the user equipment.

Figure 4 shows a representation of another example of inter-cell beam management using beams of two cells as candidate resources for transmissions to the user equipment, without a change of serving cell for the user equipment.

Figure 5 shows a representation of an example of operations at a user equipment and units of a radio access network according to an example embodiment;

Figure 6 shows a representation of another example of operations at a user equipment and units of a radio access network according to another example embodiment;

Figure 7 shows a representation of an example of apparatus for implementing operations at a gNB-CU or gNB-DU according to some example embodiments; and

Figure 8 shows a representation of an example of apparatus for implementing operations at a gNB-RU or UE according to some example embodiments; and

Figure 9 shows a representation of an example of non-volatile memory media.

DETAILED DESCRIPTION

By way of example, the following description focusses on the example of user equipment (UE) and a radio access network (RAN) operating according to 3GPP 5G technology, but the underlying technique is also applicable to user equipment and radio access networks operating according to other technologies, such as more evolved 3GPP technologies.

Fig. 1 shows a representation of one example of a simplified 3GPP 5G system architecture showing elements and functional entities relevant to the description of example embodiments below. All the units shown in Figure 1 are logical units. The connections shown in Figure 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that a 5G system may comprise also other functions and structures than those shown in Figure 1 . One or more units shown in Figure 1 may be split into multiple units. For example, each gNB central unit (gNB-CU) may be divided into core plane (CP) and user plane (UP) units.

The functionality of each NG-RAN gNB (5G base station) is split into a central unit (gNB- CU), a plurality of distributed units (gNB-DU) associated with the gNB-CU, and one or more radio units (gNB-RU) associated with each gNB-DU. A gNB-RU provides the digital front end (DFE), parts of the PHY layer functionality, and digital beamforming functionality. A gNB-DU provides Layer 1/2 (L1/2) functionality, including MAC (Medium Access Control) functionality, RLC (Radio Link Control) functionality, and part of the PHY layer functionality. A gNB-CU provides higher layer functionality including Layer 3 (L3) functionality - RRC (Radio Resource Control) functionality and PDCP (Packet Data Convergence Protocol) functionality.

Each gNB-CU is (i) connected to a user plane function (UPF) (not shown) of the core network (CN), for routing and forwarding user data packets and for providing connectivity of devices to one or more external packet data networks (DN), and (ii) is connected to an access mobility management function (AMF) (not shown) of the core network (CN) for controlling access and changes of serving cells for user equipments.

The term "user equipment" (UE) here refers to any device, apparatus or component implementing at least 3GPP user equipment (UE) functionality.

The UE may be a mobile or static device (e.g. a portable or non-portable computing device) including, but not limited to, the following types of devices: mobile phone, smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, and multimedia device. It should be appreciated that a UE device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network. A UE device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects are provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction, e.g. to be used in smart power grids and connected vehicles. The device may also utilise cloud. In some applications, a UE device may comprise a user portable device with radio parts (such as a watch, earphones or eyeglasses) and the computation is carried out in the cloud.

5G enables using multiple input - multiple output (MIMO) antennas, and may involve large numbers of base stations (gNBs) including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available. 5G mobile communications supports a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications (such as (massive) machine-type communications (mMTC), including vehicular safety, different sensors and real-time control). 5G may employ multiple radio interfaces, e.g. below 6GHz or above 24 GHz, cmWave and mmWave, and may also be integrable with existing legacy radio access technologies, such as LTE. Integration with LTE may be implemented, as a system, where macro coverage is provided by LTE and 5G radio interface access comes from small cells by aggregation to the LTE. In other words, 5G may support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz - cmWave, 6 or above 24 GHz - cmWave and mmWave). 5G networks may employ network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

Low latency applications and services may be facilitated by bringing content close to the 5G system, which leads to local break out and multi-access edge computing (MEC). 5G enables analytics and knowledge generation to occur at the source of the data. This approach may involve leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

5G may also utilize satellite communication to enhance or complement the coverage of 5G service, for example by providing backhauling. Possible use cases are providing service continuity for machine-to-machine (M2M) or Internet of Things (loT) devices or for passengers on board of vehicles, Mobile Broadband, (MBB) or ensuring service availability for critical communications, and future railway/maritime/aeronautical communications. Satellite communication may utilise geostationary earth orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular megaconstellations (systems in which hundreds of (nano)satellites are deployed). Each satellite in the mega-constellation may cover several satellite-enabled network entities that create on-ground cells. The on-ground cells may be created through an on-ground relay node or by a gNB located on-ground or in a satellite.

For simplicity of explanation, the examples described below are examples involving L1/2 mobility of a user equipment between two cells (a serving cell and a non-serving cell), without change of serving cell for the UE. The serving cell and non-serving cell may or may not be operated by the same radio unit (RU). The serving cell and non- serving cell may or may not be operated by the same transmission/reception point (TRP).

For example: a single TRP may comprise a plurality of radio transmitters operating at a respective bandwidth of e.g. 100MHs within a total bandwidth of e.g. 600MHz. The plurality of radio transmitters installed at the same TRP may provide substantially equal geographical coverage. The e.g. 100MHz cell operated by one of the radio transmitters at the TRP may provide the serving cell for a user equipment, and one or more of the other 100MHz cells operated by one or more of the other radio transmitters at the TRP may provide one or more non-serving, secondary cells for the user equipment. L1/2 mobility of the UE between serving and non-serving cells is controlled at the gNB-DU associated with the serving cell for the UE based on L1 measurements reported to the gNB-DU associated with the serving cell for the UE.

According to another example, the non-serving, secondary cell for a user equipment may be provided by a radio transmitter at another TRP at a different location to the TRP operating the serving cell for the UE. L1/2 mobility for a user equipment may involve mobility between a cell provided by a radio transmitter at one TRP and a cell provided by a radio transmitter at another TRP, without a change of serving cell for the user equipment. L1/2 mobility between cells is again controlled at the gNB-DU associated with the serving cell based on L1 measurements reported to the gNB-DU associated with the serving cell.

With reference to Figure 2, operation of an individual cell may involve operation of a plurality of downlink beams (radiation patterns). Each downlink beam (radiation pattern) has a respective geographical coverage. The most suitable downlink beam for a user equipment at a point in time may depend on the geographical location of the user equipment at that point in time.

Inter-cell beam management (ICBM) for control plane and user plane transmissions to a user equipment (UE) in connected mode may involve L1/2 mobility between beams of serving and non-serving cells for the user equipment, according to decisions at the gNB- DU associated with the serving cell for the UE, based on L1 measurements made at UE and reported by UE to the gNB-DU associated with the serving cell for the UE.

The downlink transmission beam selected for a PDCCH (Physical Downlink Control Channel) transmission for the UE may be indicated to the UE by means of a MAC CE (MAC (Medium Access Control) Control Element) command (activation command) carried by an earlier PDSCH transmission for the UE. The MAC CE command may indicate one of a plurality of beams indicated in an earlier L3 RRC configuration message.

The downlink transmission beam selected for a PDSCH (Physical Downlink Shared Channel) transmission may be indicated in the PDCCH transmission that indicates the radio resources for the PDSCH transmission.

The indication of a beam may be done by a transmission configuration indication (TCI) state of the kind described, for example, at TS 3GPP 38.331; and the downlink transmission beam for a PDSCH transmission may be indicated via a TCI field in the DCI format carried by the PDCCH transmission indicating the radio resources for the PDSCH transmission. A TCI state defines the Quasi Co-Location (QCL) information for receiving the PDCCH (Physical Downlink Control Channel) or PDSCH (Physical Downlink Shared Channel) transmission. A TCI state may indicate to UE the RS (reference signal) index (SSB index or CSI-RS index) based on which the channel information(s) (doppler shift, doppler spread, average delay, delay spread, spatial RX parameter) apply for receiving the PDCCH transmission or PDSCH transmission.

Figure 3 is a representation of L1/2 mobility between beams of serving and non-serving cells (C1 and C2) operated by the same TRP; and Figure 4 is a representation of L1/2 mobility between beams of serving and non-serving cells (C1 and C2) operated by different TRPs.

System Information

System Information (SI) for a cell (or set of cells operated from the same TRP) may be divided into (a) Minimum SI which carries basic information required for initial access (e.g. Master Information Block MIB and System Information Block 1 (SIB1 ), and (b) Other SI whose acquisition by a UE requires the UE to first acquire the Minimum SI (e.g. all system information blocks (SI Bs) other than SI B1 ). The Minimum SI is periodically transmitted by the network. In the examples described below, the Other SI is delivered by PDCSH transmissions via radio resources indicated by PDCCH transmissions.

While the UE is in RRC Connected mode receiving UE-specific PDSCH transmissions via radio resources of candidate beams of serving and non-serving cells according to a ICEJM technique, there may happen to be a change in the Other SI.

Example 1

Figure 5 shows a representation of an example of operations at a UE configured for ICEJM operation, gNEJ-DU and gNEJ-CU of Figure 1 for receiving updated Other SI, according to an example embodiment.

OPERATION 500: Part of the regular ICEJM operation involves UE periodically sending reports to gNEJ-DU of Physical Layer/Layer 1 measurements of one or more physical properties of beams of the serving and non-serving cells (C1 and C2). For example, UE may periodically send send to gNEJ-DU reports of measurements (e.g. L1 reference signal received power (RSRP) measurements) at UE of the beams of the serving and non-serving cells (C1 and C2).

OPERATION 502: gNEJ-CU sends to gNEJ-DU a L3 RRC message for UE notifying the UE of a change in Other SI for the serving cell (C1 ). The L3 RRC message, which is transparent to gNEJ-DU, is forwarded by gNEJ-DU to UE. The L3 message is carried by a PDSCH transmission. The PDSCH transmission carrying the L3 message is made via radio resources (of the serving cell C1 or the non-serving cell C2 dependent on a decision at gNEJ-DU) indicated by a PDCCH transmission of a DCI (Downlink Control Information) format with a CRC (Cyclic Redundancy Check) scrambled by an identifier specific to the UE (e.g. 3GPP Cell Radio Network Temporary Identifier (C-RNTI) specific to the UE). The PDCCH transmission is made within a UE-specific search space in a control resource set (CORESET). The L3 message includes a parameter indicating a time duration value for temporary disablement or pausing of ICEJM (which time duration value is hereafter referred to as ICEJM Disable Timer value). The L3 message also configures the UE to indicate to gNB-DU the start and end of an operation at the UE to read Other SI for the serving cell. Further below is described an example of a UE procedure for indicating the start and end of an operation to read Other SI for the serving cell.

UE successfully decodes the PDCCH transmission, and receives the PDSCH transmission carrying the L3 message via the radio resources indicated by the PDCCH transmission.

OPERATION 504: UE may be configured to initiate the following procedure in response to receiving a L3 message indicating a change in Other SI for the serving cell (C1 ).

OPERATION 506: At the first periodic occasion for sending a L1 -RSRP report after receiving the above-mentioned L3 message indicating a change in Other SI for the serving cell, UE includes in the L1 -RSRP report an indication to gNB-DU to temporarily suspend sending of MAC commands to UE to monitor a beam of a non-serving cell for control transmissions. If the UE is currently configured to monitor a beam of the serving cell for PDCCH transmissions, the indication is an indication to gNB-DU to suspend sending any MAC command to UE to switch from monitoring the serving cell C1 for PDCCH transmissions to monitoring a cell other than the serving cell C1 for PDCCH transmissions. On the other hand, if the UE is currently configured to monitor a beam of non-serving cell C2 for PDCCH transmissions, the indication is an indication to gNB DU to suspend all MAC operations for UE, not only TCI state changes.

The indication may be carried by a single bit (hereafter referred to as ICBM-Pause bit) in the L1 -RSRP report.

In another example, UE does not wait until the first periodic occasion for sending a L1 - RSRP report after receiving the above-mentioned L3 message report, but instead includes the ICBM Pause bit in an event-based L1 -RSRP report triggered by receipt of the L3 RRC message mentioned above.

OPERATION 508: In response to detecting that the ICBM-Pause bit in the L1 -RSRP report is set to "1", gNB-DU starts the ICBM Disable Timer, and disables ICBM for UE until the ICBM Disable Timer expires (or before then in the event of receiving a new L1 -RSRP report from UE before expiry of the ICBM Disable Timer). Depending on the current configuration of UE (i.e. whether UE is currently configured to monitor a non-serving cell C2 for PDCCH transmissions, or currently configured to monitor the serving cell C1 for PDCCH transmissions, temporary disablement or pausing of ICBM for UE either (a) involves gNB-DU suspending all MAC operations for UE, or (b) involves gNEJ-DU continuing MAC operations for UE but suspending sending any MAC CE command to UE to switch from monitoring a beam of serving cell C1 for PDCCH transmissions to monitoring a beam of non-serving cell C2 for PDCCH transmissions.

OPERATION 510: UE newly acquires Other SI for the serving cell C1 via a PDSCH transmission via radio resources of the serving cell C1 indicated by a PDCCH transmission in a common search space (CSS) in a set of serving cell C1 radio resources (Control Resource Set (CORESET)) reserved for one or more common search spaces. The PDCCH transmission carries a DCI format with a CRC scrambled by a common RNTI that is not specific to any individual UE (SI-RNTI (System Information Radio Network Temporary Identifier)).

OPERATON 512: After newly acquiring the Other SI for the serving cell C1, UE recommences sending periodic L1 -RSRP reports, beginning from the first periodic occasion for sending a L-RSRP report after completing reading of Other SI. UE transmits a new L1 -RSRP report for gNEJ-DU, including results of beam measurements for the serving and non-serving cells C1 and C2. These cell beam measurement results may include results of non-serving, secondary cell (C2) beam measurements that UE continued to make during the period in which ICBM operation was suspended, and UE was newly acquiring Other SI for the serving cell C1 .

OPERATION 514: This L1 -RSRP report from UE triggers gNB-DU to recommence ICBM operation for UE, even if the ICBM Disable Timer has not yet expired.

During the period in which ICBM is suspended for UE, gNB-DU may continue to make serving cell C1 PDCCH transmissions dedicated to UE (carrying a DCI format with a CRC scrambled by an identifier specific to the UE (C-RNTI for UE)) in the specific search space for UE. Example 2

Figure 6 shows a representation of another example of operations at a UE configured for ICBM operation, gNB-DU and gNB-CU of Figure 1 for newly receiving "Other SI" system information for serving cell C1, according to another example embodiment.

OPERATION 600: Part of the regular ICBM operation involves UE periodically sending reports to the gNB-DU of Physical Layer/Layer 1 measurements of one or more physical properties of beams of the serving and non-serving cells C1 and C2. For example, UE may periodically send to gNB-DU reports of measurements (e.g. L1 reference signal received power (RSRP) measurements) at UE of the beams of the serving and nonserving cells C1 and C2.

OPERATION 602: gNB-CU sends to gNB-DU a L3 RRC message for UE notifying UE of a change in Other SI. The L3 RRC message, which is transparent to gNB-DU, is forwarded by the gNB-DU to UE.

The following operations are for the event that UE is currently configured by MAC CE command to monitor non-serving cell C2 for PDCCH transmissions.

OPERATION 604: UE is configured to, in response to receiving such L3 message, monitor a specific search space (specific SS) of non-serving cell C2 for PDCCH transmissions carrying a DCI format with a CRC scrambled by a common (non-UE- specific) identifier SI-RNTI. UE also continues monitoring the specific search space of non-serving cell C2 for PDCCH transmissions carrying a DCI format with a CRC scrambled by a UE-specific identifier (C-RNTI for UE).

OPERATIONS 606 AND 608: In response to a command from gNB-CU via the F1 interface, gNB-DU performs the following operations. gNB-DU makes a PDCCH transmission in a common search space (CSS) in a control resource set reserved for common search spaces (e.g. 5G CORESET) for the serving cell C1 . The PDCCH transmission carries a DCI format with a CRC scrambled by a common (non-UE-specific) identifier (SI-RNTI). The PDCCH transmission indicates radio resources for a serving cell (C1 ) PDSCH transmission carrying the "Other SI" for the serving cell C1 . gNB-DU also makes in a UE-specific search space for UE in a control resource set (CORESET) of non-serving cell C2, a PDCCH transmission carrying a DCI format with a CRC scrambled by the same common (non-UE-specific) identifier (SI-RNTI), and indicates the same radio resources for a serving cell (C1 ) PDSCH transmission carrying the "Other SI" for serving cell C1 .

In response to receiving via a specific search space comprising radio resources of nonserving cell C2 a PDCCH transmission carrying a DCI format with a CRC scrambled by common (non-UE-specific) identifier (SI-RNTI), UE switches to the serving cell C1 to newly acquire Other SI for the serving cell C1 .

The same radio resources for a serving cell (C1 ) PDSCH transmission carrying the "Other SI" are also indicated in PDCCH transmissions for other UEs via respective specific search spaces of the non-serving cell C2 for those other UEs served by the same serving cell C1.

OPERATION 610: gNB-DU may also continue to make, in the UE-specific search space of non-serving cell C2 for UE, PDCCH transmissions carrying DCI formats with a CRC scrambled by an identifier specific to UE (C-RNTI for UE), and indicating serving or secondary cell (C1 or C2) beams for PDSCH transmissions specific to UE.

As mentioned above, the above-described operations are for the event that UE is currently configured to monitor the non-serving cell C2 for PDCCH transmissions. If UE is instead currently configured to monitor the serving cell C1 for PDCCH transmissions, UE monitors serving cell CSS for a PDCCH transmission decodable by common (non UE- specific) identifier SI-RNTI.

In the examples described above, the serving and secondary cells C1 and C2 are operated by the same TRP, but the serving and secondary cells C1 and C2 may also be operated by different TRPs.

If the serving and secondary cells are operated by different TRPs, the use of the second example described above is facilitated by configuring UE to, in response to receiving the L3 message indicating a change in Other SI, additionally monitor a common search space in a control resource set (CORESET) for the non-serving, secondary cell (C2).

The above-described techniques can avoid configuring the UE with a static TDM (Time Division Mutliplexing) pattern statically defining times at which ICBM is suspended and UE may newly acquire Other SI for the serving cell. The above-described techniques can have a positive impact on throughput for all ongoing connections for the UE, while ensuring that UE can newly acquire Other SI for the serving cell regardless of the time required to do so, which may be dependent on radio conditions for the UE.

Figure 7 illustrates an example of an apparatus for implementing UE functionality or gNEJ-RU functionality in Figure 1 . The apparatus may include at least one processor 802 coupled to one or more interfaces 808. For UE apparatus, the one or more interfaces 808 may include one or more interfaces to e.g. other equipment/component(s) for which the UE functionality provides radio communications. For gNEJ-RU apparatus, the one or more interfaces 808 may include an interface to the gNEJ-DU associated with the gNEJ-RU. The at least one processor 802 is also coupled to a radio unit 804 including one or more antennas etc. for making and receiving radio transmissions. The at least one processor 802 may also be coupled to at least one memory 806. The at least one processor 802 may be configured to execute an appropriate software code to perform the operations described above. The software code may be stored in the memory 806.

Figure 8 illustrates an example of an apparatus for implementing gNEJ-DU functionality or gNEJ-CU functionality in Figure 1 . The apparatus may include at least one processor 902 coupled to one or more interfaces 908. For gNEJ-DU apparatus, the one or more interfaces 908 may include interfaces for communication with gNEJ-RUs associated with the gNEJ-DU, and an interface for communication with the gNEJ-CU associated with the gNEJ-DU. For the gNEJ-CU apparatus, the one or more interfaces 908 may include interfaces for communication with the gNEJ-DUs associated with the gNEJ-CU, and interfaces for communication with 5GC functions, such as UPF and AMF. The at least one processor 902 may also be coupled to at least one memory 906. The at least one processor 902 may be configured to execute an appropriate software code to perform the operations described above. The software code may be stored in the memory 906.

Figure 9 shows a schematic representation of non-volatile memory media 1100a (e.g. computer disc (CD) or digital versatile disc (DVD)) and 1100b (e.g. universal serial bus (USB) memory stick) storing instructions and/or parameters 1102 which when executed by a processor allows the processor to perform one or more of the steps of the methods described previously.

It is to be noted that example embodiments may be implemented as circuitry, in software, hardware, application logic or a combination of software, hardware and application logic. In an example embodiment, the application logic, software or an instruction set is maintained on any computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as the base stations or user equipment of the above-described example embodiments.

As used in this application, the term "circuitry" refers to all of the following: (a) hardware- only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the user equipment or base stations of the above-described embodiments, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of 'circuitry' applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device.

The features, advantages, and characteristics described herein can be combined in any suitable manner in one or more example embodiments. One skilled in the relevant art will recognize that such example embodiments can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages can be recognized in certain embodiments that may not be present in all example embodiments. One having ordinary skill in the art will readily understand that the example embodiments as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although some embodiments have been described based upon these example embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of example embodiments.

Claims

1. A method, comprising: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

2. The method according to claim 1 : wherein, in the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or wherein, in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

3. The method according to claim 1 or claim 2, wherein the message indicating a change in system information indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

4. The method according to any of claims 1 to 3, comprising: after newly acquiring system information, transmitting a message for the distributed unit triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

5. The method according to claim 4, wherein the message triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a report of beam measurements at the user equipment.

6. The method according to any of claims 1 to 5, wherein the serving cell is operated by a first transmission-reception point, and the one or more other cells comprise one or more cells operated at the first transmission-reception point, and/or one or more cells operated at one or more other transmission-reception points.

7. The method according to any preceding claim, wherein the command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a medium access control command actuating a transmission configuration indicator state change at the user equipment.

8. A method, comprising: receiving at a distributed unit of an access network a message from a user equipment configured for inter cell beam management operation, indicating results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

9. The method according to claim 8: wherein, in the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or wherein, in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

10. The method according to claim 8 or claim 9, comprising: in response to the message from the user equipment, temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; wherein the temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions is continued for a time period ending with the expiry of a timer at the distributed unit or ending upon receiving at the distributed unit a message from the user equipment triggering the distributed unit to end temporary suspension of temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

11 . The method according to claim 10, wherein the message triggering the distributed unit to end temporary suspension of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a layer 1 report of beam measurements at the user equipment.

12. The method according to any of claims 8 to 11, wherein the serving cell is operated by a first transmission-reception point, and the one or more other cells comprise one or more cells operated at the first transmission-reception point, and/or one or more cells operated at one or more other transmission-reception points.

13. The method according to any of claims 8 to 12, wherein the command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a medium access control command actuating a transmission configuration indicator state change at the user equipment.

14. A method comprising: sending to a distributed unit of a radio access network from a central unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information

15. A method comprising: transmitting from a user equipment configured for inter-cell beam management operation a report for a distributed unit of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving at the user equipment a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

16. The method according to claim 15, wherein the search space is a search space specific to the user equipment; and wherein monitoring the search space comprises monitoring the search space for a control transmission decodable at the user equipment using an identifier not specific to the user equipment.

17. The method according to claim 15, wherein the search space is a search space provided for system information reception during inter cell beam management operation.

18. The method according to claim 15, comprising: in response to receiving via the search space a control transmission indicating radio resources for transmission of system information for the serving cell, , switching to the serving cell for reception of system information of the serving cell.

19. A method comprising: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

20. The method according to claim 19, wherein the search space is specific to the user equipment, and the control transmission is decodable at the user equipment using an identifier not specific to the user equipment.

21 . The method according to claim 19, further comprising: determining to make within the search space a control transmission decodable at the user equipment using an identifier specific to the user equipment.

22. The method according to claim 21, comprising determining to make, via the cell other than the serving cell, within one or more other search spaces specific to one or more other user equipments, one or more other control transmissions indicating the same radio resources for transmission of system information for the serving cell.

23. User equipment, comprising: means for transmitting an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; means for receiving a message indicating a change in system information; and means for transmitting a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions .

24. The user equipment according to claim 23: wherein, in the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or wherein, in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

25. The user equipment according to claim 23 or claim 24, wherein the message indicating a change in system information indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

26. The user equipment according to any of claims 23 to 25, comprising: means for, after newly acquiring system information, transmitting a message for the distributed unit triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

27. The user equipment according to claim 26, wherein the message triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a report of beam measurements at the user equipment.

28. The user equipment according to any of claims 23 to 27 , wherein the serving cell is operated by a first transmission-reception point, and the one or more other cells comprise one or more cells operated at the first transmission-reception point, and/or one or more cells operated at one or more other transmission-reception points.

29. The user equipment according to any of claims 23 to 28, wherein the command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a medium access control command actuating a transmission configuration indicator state change at the user equipment.

30. A distributed unit, comprising: means for receiving a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and means for receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

31 . The user equipment according to claim 30: wherein, in the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or wherein, in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

32. The distributed unit according to claim 30 or claim 31, comprising: means for, in response to the message from the user equipment, temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; wherein the temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions is continued for a time period ending with the expiry of a timer at the distributed unit or ending upon receiving at the distributed unit a message from the user equipment triggering the distributed unit to end temporary suspension of temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

33. The distributed unit according to claim 32, wherein the message triggering the distributed unit to end temporary suspension of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a layer 1 report of beam measurements at the user equipment.

34 The distributed unit according to any of claims 30 to 33, wherein the serving cell is operated by a first transmission-reception point, and the one or more other cells comprise one or more cells operated at the first transmission-reception point, and/or one or more cells operated at one or more other transmission-reception points.

35. The distributed unit according to any of claims 30 to 34, wherein the command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a medium access control command actuating a transmission configuration indicator state change at the user equipment.

36. A central unit of a radio access network, comprising: means for sending to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information

37. A user equipment comprising: means for transmitting an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; means for receiving at the user equipment a message indicating a change in system information; and means for monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

38. The user equipment according to claim 37, wherein the search space is a search space specific to the user equipment; and wherein the means for monitoring the search space comprises means for monitoring the search space for a control transmission decodable at the user equipment using an identifier not specific to the user equipment.

39. The user equipment according to claim 37, wherein the search space is a search space provided for system information reception during inter cell beam management operation.

40. The user equipment according to claim 37, comprising: means for, in response to receiving via the search space a control transmission indicating radio resources for transmission of system information for the serving cell, , switching to the serving cell for reception of system information of the serving cell.

41. A distributed unit comprising: means for determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

42. The distributed unit according to claim 41, wherein the search space is specific to the user equipment, and the control transmission is decodable at the user equipment using an identifier not specific to the user equipment.

43. The distributed unit according to claim 41, further comprising: means for determining to make within the search space a control transmission decodable at the user equipment using an identifier specific to the user equipment.

44. The distributed unit according to claim 21, comprising: means for determining to make, via the cell other than the serving cell, within one or more other search spaces specific to one or more other user equipments, one or more other control transmissions indicating the same radio resources for transmission of system information for the serving cell.

45. User equipment comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the user equipment to perform: transmitting an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving a message indicating a change in system information; and transmitting a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

46. The user equipment according to claim 45: wherein, in the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or wherein, in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

47. The user equipment according to claim 45 or claim 46, wherein the message indicating a change in system information indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

48. The user equipment according to any of claims 45 to 47, wherein the at least one memory and computer program code are configured to, with the at least one processor, cause the user equipment to: after newly acquiring system information, transmit a message for the distributed unit triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

49. The user equipment according to claim 48, wherein the message triggering the distributed unit to end temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a report of beam measurements at the user equipment.

50. The user equipment according to any of claims 45 to 49, wherein the serving cell is operated by a first transmission-reception point, and the one or more other cells comprise one or more cells operated at the first transmission-reception point, and/or one or more cells operated at one or more other transmission-reception points.

51 . The user equipment according to any of claims 45 to 50, wherein the command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a medium access control command actuating a transmission configuration indicator state change at the user equipment.

52. A distributed unit of an access network, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the distributed unit to perform: receiving a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

53. The distributed unit according to claim 52: wherein, in the event that the user equipment is currently configured to monitor the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending commands to switch from monitoring the serving cell for control transmissions; or wherein, in the event that the user equipment is currently configured to monitor a cell other than the serving cell for control transmissions, the message for the distributed unit triggers the distributed unit to temporarily suspend sending any medium access control command to the user equipment.

54. The distributed unit according to claim 52 or claim 53, wherein the at least one memory and computer program code are configured to, with the at least one processor, cause the distributed unit to: in response to the message from the user equipment, temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; wherein the temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions is continued for a time period ending with the expiry of a timer at the distributed unit or ending upon receiving at the distributed unit a message from the user equipment triggering the distributed unit to end temporary suspension of temporarily suspending sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

55. The distributed unit according to claim 54, wherein the message triggering the distributed unit to end temporary suspension of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a layer 1 report of beam measurements at the user equipment.

56. The distributed unit according to any of claims 52 to 55, wherein the serving cell is operated by a first transmission-reception point, and the one or more other cells comprise one or more cells operated at the first transmission-reception point, and/or one or more cells operated at one or more other transmission-reception points.

57. The distributed unit according to any of claims 52 to 56, wherein the command to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions comprises a medium access control command actuating a transmission configuration indicator state change at the user equipment.

58. A central unit of a radio access network, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the central unit to perform: sending to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information

59. A user equipment comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the user equipment to perform: transmitting an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

60. The user equipment according to claim 15, wherein the search space is a search space specific to the user equipment; and wherein the at least one memory and computer program code are configured to, with the at least one processor, cause the user equipment to monitor the search space for a control transmission decodable at the user equipment using an identifier not specific to the user equipment.

61 . The user equipment according to claim 59, wherein the search space is a search space provided for system information reception during inter cell beam management operation.

62. The user equipment according to claim 59, wherein the at least one memory and computer program code are configured to, with the at least one processor, cause the user equipment to: in response to receiving via the search space a control transmission indicating radio resources for transmission of system information for the serving cell, switch to the serving cell for reception of system information of the serving cell.

63. A distributed unit a radio access network, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the distributed unit to perform: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

64. The distributed unit according to claim 63, wherein the search space is specific to the user equipment, and the control transmission is decodable at the user equipment using an identifier not specific to the user equipment.

65. The distributed unit according to claim 63, wherein the at least one memory and computer program code are configured to, with the at least one processor, cause the distributed unit to: determine to make within the search space a control transmission decodable at the user equipment using an identifier specific to the user equipment.

66. The distributed unit according to claim 65, wherein the at least one memory and computer program code are configured to, with the at least one processor, cause the apparatus to:

Determine to make, via the cell other than the serving cell, within one or more other search spaces specific to one or more other user equipments, one or more other control transmissions indicating the same radio resources for transmission of system information for the serving cell.

67. User equipment, comprising: transmitting circuitry for transmitting an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving circuitry for receiving a message indicating a change in system information; and transmitting circuitry for transmitting a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

68. A distributed unit of an access network, comprising: receiving circuitry for receiving a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving circuitry for receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

69. A central unit of a radio access network, comprising: sending circuitry for sending to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information

70. User equipment comprising: transmitting circuitry for transmitting an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving circuitry for receiving a message indicating a change in system information; and monitoring circuitry for monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

71 . A distributed unit a radio access network, comprising: determining circuitry for determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

72. A computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

73. A computer readable medium comprising program instructions stored thereon for performing: receiving at a distributed unit of an access network a message from a user equipment configured for inter cell beam management operation, indicating results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

74. A computer readable medium comprising program instructions stored thereon for performing: sending to a distributed unit of a radio access network from a central unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

75. A computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter-cell beam management operation a report for a distributed unit of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving at the user equipment a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

76. A computer readable medium comprising program instructions stored thereon for performing: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

77. A non-transitory computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter cell beam management operation, a message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receiving at the user equipment a message indicating a change in system information; and transmitting from the user equipment a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

78. A non-transitory computer readable medium comprising program instructions stored thereon for performing: receiving at a distributed unit of an access network a message from a user equipment configured for inter cell beam management operation, indicating results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receiving a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

79. A non-transitory computer readable medium comprising program instructions stored thereon for performing: sending to a distributed unit of a radio access network from a central unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

80. A non-transitory computer readable medium comprising program instructions stored thereon for performing: transmitting from a user equipment configured for inter-cell beam management operation a report for a distributed unit of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receiving at the user equipment a message indicating a change in system information; and monitoring a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

81 . A non-transitory computer readable medium comprising program instructions stored thereon for performing: determining to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.

82. A computer program comprising computer executable code which when run on at least one processor is configured to cause a user equipment at least to: transmit an inter cell beam management operation message for a distributed unit of a radio access network, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one more other cells; receive a message indicating a change in system information; and transmit a message for the distributed unit triggering the distributed unit to temporarily suspend sending of commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

83. A computer program comprising computer executable code which when run on at least one processor is configured to cause a distributed unit of a radio access network at least to: receive a message from a user equipment configured for inter cell beam management operation, wherein the message indicates results of physical layer measurements at the user equipment of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; and receive a message from the user equipment triggering the distributed unit to temporarily suspend sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions.

84. A computer program comprising computer executable code which when run on at least one processor is configured to cause a central unit of a radio access network at least to: send to a distributed unit of the radio access network a message for a user equipment; wherein the message indicates a maximum time duration for temporary suspension at the distributed unit of sending commands to the user equipment to monitor a beam other than a beam of the serving cell for control transmissions; and/or configures the user equipment to indicate to the distributed unit a start and an end of an operation at the user equipment to read system information.

85. A computer program comprising computer executable code which when run on at least one processor is configured to cause a user equipment at least to: transmit an inter-cell beam management operation message for a distributed unit, wherein the message indicates results of physical layer measurements of beams comprising one or more beams of a serving cell for the user equipment, and one or more beams of one or more other cells; receive a message indicating a change in system information; and monitor a search space of a cell other than the serving cell for a control transmission indicating radio resources for transmission of system information for the serving cell.

86. A computer program comprising computer executable code which when run on at least one processor is configured to cause a distributed unit of a radio access network at least to: determine to make within a search space of a cell other than a serving cell for the user equipment a control transmission indicating radio resources for transmission of system information for the serving cell.