Apparatus, method, and computer program

Abstract

Determination of whether a cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running. The timer is configured t

Description

Field of the disclosure The present disclosure relates to an apparatus, a method, and a computer program for determining whether a cell is known in a communication system. Background A communication system can be seen as a facility that enables communication sessions between two or more entities such as communication devices, base stations and / or other nodes by providing carriers between the various entities involved in the communications path. The communication system may be a wireless communication system. Examples of wireless systems comprise public land mobile networks (PLMN) operating based on radio standards such as those provided by 3GPP, satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems. The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and / or parameters which shall be used for the connection are also typically defined. Examples of standard are the so-called 5G standards. Summary According to an aspect there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a command to configure or activate a cell; determine (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determine whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a command to configure or activate a cell; determine (i) that the command is a first command to configure or activate the cell or (ii) that the timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determine that the cell is known based on determining (i) that the command is a first command to configure or activate the cell or (ii) that the timer is running. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the cell; determine that the timer is running; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the cell; determine that the timer is running; determine that during a first time period before receiving the command to activate the cell a measurement report for the cell has been sent by the apparatus; determine that a synchronization signal block of the cell is detectable by the apparatus; determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to configure the cell; determine that the timer is running; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to configure the cell; determine that the timer is running ; determine that during a first time period before receiving the command to configure the cell, a measurement report for the cell has been sent; determine that a synchronization signal block of the cell is detected; determine that during a second time period after receiving the command to configure the cell a synchronization signal block of the is detected by the apparatus; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the cell; determine that the command is a first command to activate the cell; determine that during a first time period before receiving the command to activate the cell a measurement report for the cell has been sent by the apparatus; determine that a synchronization signal block of the cell is detectable by the apparatus; determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to configure the cell; determine that the command is a first command to configure the cell; determine that during a first time period before receiving the command to configure the cell, a measurement report for the cell has been sent by the apparatus; determine that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to configure the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a command to configure or activate a cell; determine (i) that the command is not a first command to configure or activate the cell or (ii) that the timer is not running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determine that the cell is known based on determining (i) that the command is not a first command to configure or activate the cell or (ii) that the timer is not running. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the cell; determine that the command is not a first command to activate the cell; determine that a synchronization signal block of the cell is detectable by the apparatus; determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to configure the cell; determine that the command is not a first command to configure the cell; determine that a synchronization signal block of the cell is detectable by the apparatus; determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the cell; determine that the timer is not running; determine that a synchronization signal block of the cell is detectable by the apparatus; determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to configure the cell; determine that the timer is not running; determine that a synchronization signal block of the cell is detectable by the apparatus; determine that during a second time period after receiving the command to configure the cell a synchronization signal block of the cell is detectable by the apparatus; and determine that the cell is known. The first time period may be a five second time period. The second time period may be an activation delay. The command may be a secondary cell group command; and the cell may be a primary cell of the secondary cell group or a secondary cell of the secondary cell group. The command may be a master cell group command; and the cell is a primary cell of the master cell group or a secondary cell of the master cell group. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: perform a random access channel less procedure with the cell. Determining that the cell is known may comprise changing a state of the cell from unknown to known. The command to configure or activate the cell may be received on a primary cell of a master cell group. The measurement report may be sent on the primary cell of the master cell group. The apparatus may be a user equipment. The apparatus may operate in FR2. According to an aspect there is provided an apparatus comprising: means for receiving a command to configure or activate a cell; means for determining (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and means for determining whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running. According to an aspect there is provided an apparatus comprising circuitry configured to: receive a command to configure or activate a cell; determine (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determine whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running. According to an aspect there is provided a method comprising: receiving a command to configure or activate a cell; determining (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determining whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running. The method may be performed by an apparatus. The method may comprise: receiving a command to configure or activate a cell; determining (i) that the command is a first command to configure or activate the cell or (ii) that the timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determining that the cell is known based on determining (i) that the command is a first command to configure or activate the cell or (ii) that the timer is running. The method may comprise: receiving the command to activate the cell; determining that the timer is running; and determining that the cell is known. The method may comprise: receiving the command to activate the cell; determining that the timer is running; determine that during a first time period before receiving the command to activate the cell a measurement report for the cell has been sent by the apparatus; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The method may comprise: receiving the command to configure the cell; determining that the timer is running; and determining that the cell is known. The method may comprise: receiving the command to configure the cell; determining that the timer is running ; determining that during a first time period before receiving the command to configure the cell, a measurement report for the cell has been sent; determining that a synchronization signal block of the cell is detected; determining that during a second time period after receiving the command to configure the cell a synchronization signal block of the is detected by the apparatus; and determining that the cell is known. The method may comprise: receiving the command to activate the cell; determining that the command is a first command to activate the cell; determining that during a first time period before receiving the command to activate the cell a measurement report for the cell has been sent by the apparatus; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The method may comprise: receiving the command to configure the cell; determining that the command is a first command to configure the cell; determining that during a first time period before receiving the command to configure the cell, a measurement report for the cell has been sent by the apparatus; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to configure the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a command to configure or activate a cell; determine (i) that the command is not a first command to configure or activate the cell or (ii) that the timer is not running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determine that the cell is known based on determining (i) that the command is not a first command to configure or activate the cell or (ii) that the timer is not running. The method may comprise: receiving the command to activate the cell; determining that the command is not a first command to activate the cell; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The method may comprise: receiving the command to configure the cell; determining that the command is not a first command to configure the cell; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The method may comprise: receiving the command to activate the cell; determining that the timer is not running; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The method may comprise: receiving the command to configure the cell; determining that the timer is not running; determining that a synchronization signal block of the cell is detectable by the apparatus; determining that during a second time period after receiving the command to configure the cell a synchronization signal block of the cell is detectable by the apparatus; and determining that the cell is known. The first time period may be a five second time period. The second time period may be an activation delay. The command may be a secondary cell group command; and the cell may be a primary cell of the secondary cell group or a secondary cell of the secondary cell group. The command may be a master cell group command; and the cell is a primary cell of the master cell group or a secondary cell of the master cell group. The method may comprise: performing a random access channel less procedure with the cell. Determining that the cell is known may comprise changing a state of the cell from unknown to known. The command to configure or activate the cell may be received on a primary cell of a master cell group. The measurement report may be sent on the primary cell of the master cell group. The apparatus may be a user equipment. The apparatus may operate in FR2. According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to: receive a command to configure or activate a cell; determine (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; and determine whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running. According to an aspect there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a command to activate a primary cell of a secondary cell group; determine (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the primary cell of the secondary cell group and stopped in response to receiving a command to activate the primary cell of the secondary cell group; and determine whether the primary cell of the secondary cell group is known based on determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether the timer is running. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the primary cell of the secondary cell group; determine that the command is a first command to activate the primary cell of the secondary cell group; determine that during a first time period before receiving the command to activate the primary cell of the secondary cell group a measurement report for the primary cell of the secondary cell group has been sent by the apparatus; determine that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determine that during a second time period after receiving the command to activate the primary cell of the secondary cell group a synchronization signal block of the cell is detectable by the apparatus; and determine that the primary cell of the secondary cell group is known. The least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the primary cell of the secondary cell group; determine that the command is not a first command to activate the primary cell of the secondary cell group; determine that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determine that during a second time period after receiving the command to activate the primary cell of the secondary cell group a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; and determine that the primary cell of the secondary cell group is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the primary cell of the secondary cell group; determine that the timer is running; determine that during a first time period before receiving the command to activate the primary cell of the secondary cell group a measurement report for the primary cell of the secondary cell group has been sent by the apparatus; determine that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determine that during a second time period after receiving the secondary cell group to activate the primary cell of the secondary cell group a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; and determine that the primary cell of the secondary cell group is known. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: receive the command to activate the primary cell of the secondary cell group; determine that the timer is not running; determine that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determine that during a second time period after receiving the command to activate the primary cell of the secondary cell group a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; and determine that the primary cell of the secondary cell group is known. The first time period may be a five seconds time period. The second time period may be an activation delay. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus at least to: perform a random access channel less procedure with the primary cell of the secondary cell group. Determining that the primary cell of the secondary cell group is known may comprise changing a state of the primary cell of the secondary cell group from unknown to known. The apparatus may be a user equipment. The apparatus may operate in FR2. According to an aspect there is provided an apparatus comprising means for: receiving a command to activate a primary cell of a secondary cell group; determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the primary cell of the secondary cell group and stopped in response to receiving a command to activate the primary cell of the secondary cell group; and determining whether the primary cell of the secondary cell group is known based on determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether the timer is running. According to an aspect there is provided an apparatus comprising circuitry configured to: receive a command to activate a primary cell of a secondary cell group; determine (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the primary cell of the secondary cell group and stopped in response to receiving a command to activate the primary cell of the secondary cell group; and determine whether the primary cell of the secondary cell group is known based on determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether the timer is running. According to an aspect there is provided a method comprising: receiving a command to activate a primary cell of a secondary cell group; determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the primary cell of the secondary cell group and stopped in response to receiving a command to activate the primary cell of the secondary cell group; and determining whether the primary cell of the secondary cell group is known based on determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether the timer is running. The method may be performed by an apparatus. The method may comprise: receiving the command to activate the primary cell of the secondary cell group; determine that the command is a first command to activate the primary cell of the secondary cell group; determining that during a first time period before receiving the command to activate the primary cell of the secondary cell group a measurement report for the primary cell of the secondary cell group has been sent by the apparatus; determining that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determining that during a second time period after receiving the command to activate the primary cell of the secondary cell group a synchronization signal block of the cell is detectable by the apparatus; and determining that the primary cell of the secondary cell group is known. The method may comprise: receiving the command to activate the primary cell of the secondary cell group; determining that the command is not a first command to activate the primary cell of the secondary cell group; determining that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determining that during a second time period after receiving the command to activate the primary cell of the secondary cell group a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; and determining that the primary cell of the secondary cell group is known. The method may comprise: receiving the command to activate the primary cell of the secondary cell group; determining that the timer is running; determine that during a first time period before receiving the command to activate the primary cell of the secondary cell group a measurement report for the primary cell of the secondary cell group has been sent by the apparatus; determining that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determining that during a second time period after receiving the secondary cell group to activate the primary cell of the secondary cell group a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; and determining that the primary cell of the secondary cell group is known. The method may comprise: receiving the command to activate the primary cell of the secondary cell group; determine that the timer is not running; determine that a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; determining that during a second time period after receiving the command to activate the primary cell of the secondary cell group a synchronization signal block of the primary cell of the secondary cell group is detectable by the apparatus; and determining that the primary cell of the secondary cell group is known. The first time period may be a five seconds time period. The second time period may be an activation delay. The method may comprise: performing a random access channel less procedure with the primary cell of the secondary cell group. Determining that the primary cell of the secondary cell group is known may comprise changing a state of the primary cell of the secondary cell group from unknown to known. The apparatus may be a user equipment. The apparatus may operate in FR2. According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to: receive a command to activate a primary cell of a secondary cell group; determine (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the primary cell of the secondary cell group and stopped in response to receiving a command to activate the primary cell of the secondary cell group; and determine whether the primary cell of the secondary cell group is known based on determining (i) whether the command is a first command to activate the primary cell of the secondary cell group or (ii) whether the timer is running. According to an aspect, there is provided a computer readable medium comprising program instructions stored thereon for performing at least one of the above methods. According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least one of the above methods. According to an aspect, there is provided a non-volatile tangible memory medium comprising program instructions stored thereon for performing at least one of the above methods. 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. List of abbreviations AF: Application Function Al: Artificial Intelligence AMF: Access and Mobility Management Function API: Application Programming Interface BFD: Beam Failure Detection BS: Base Station CU: Centralized Unit CSI-RS: Channel State Information Reference Signal DL: Downlink DU: Distributed Unit gNB: gNodeB HSS: Home Subscriber Server loT: Internet of Things LMF: Location Management Function 5 LTE: Long Term Evolution MAC: Medium Access Control MCG: Master Cell Group ML: Machine Learning MS: Mobile Station 10 MTC: Machine Type Communication NEF: Network Exposure Function NF: Network Function NR: New radio NRF: Network Repository Function 15 PCell: Primary cell (of the master cell group) PDCCH: Physical Downlink Control Channel PDSCH: Physical Downlink Shared Channel PDU: Packet Data Unit PSCell: Primary cell (of the secondary cell group) 20 PUCCH: Physical Uplink Control Channel PUSCH: Physical Uplink Shared Channel RAM: Random Access Memory (R)AN: (Radio) Access Network ROM: Read Only Memory 25 RACH: Random Access Channel RLM: Radio Link Monitoring SCell: Secondary cell SCG: Secondary cell group SMF: Session Management Function 30 SSB: Synchronization Signal Block TA: Timing Advance TAT: Timing Advance Timer TS: Technical Specification UE: User Equipment 35 UMTS: Universal Mobile Telecommunication System 3GPP: 3rd Generation Partnership Project 5G: 5th Generation 5GC: 5G Core network 5GS: 5G System Brief Description of the Figures Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which: Fig. 1 shows a schematic representation of a 5G system; Fig. 2 shows a schematic representation of a control apparatus; Fig. 3 shows a schematic representation of a user equipment; Fig. 4 shows a schematic representation of a user equipment in dual connectivity with a master gNodeB and a secondary gNodeB; Fig. 5 shows a timeline of a method for determining whether a primary cell of a secondary cell group is known; Fig. 6 shows a timeline of another method for determining whether a primary cell of a secondary cell group is known; Fig. 7 shows a block diagram of a method for determining whether a cell is known; Fig. 8 shows a block diagram of a method for determining whether a primary cell of a secondary cell group is known; and Fig. 9 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the methods of Fig. 7 and Fig. 8. Detailed Description of the Figures In the following certain embodiments are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the exemplifying embodiments, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to Fig. 1, Fig.2 and Fig.3 to assist in understanding the technology underlying the described examples. FIG. 1 shows a schematic representation of a 5G system (5GS). The 5GS may comprises a user equipment (UE), a (radio) access network ((R)AN), a 5G core network (5GC), one or more application functions (AF) and one or more data networks (DN). The 5G (R)AN may comprise one or more gNodeB (gNB) distributed unit functions connected to one or more gNodeB (gNB) centralized unit functions. The 5GC may comprise an access and mobility management function (AMF), a session management function (SMF), an authentication server function (AUSF), a user data management (UDM), a user plane function (UPF), a network exposure function (NEF), a unified data repository (UDR) and / or a location management function (LMF). Fig. 2 illustrates an example of a control apparatus 200 for controlling a function of the (R)AN or the 5GC as illustrated on Fig. 1. The control apparatus may comprise at least one random access memory (RAM) 211a, at least on read only memory (ROM) 211b, at least one processor 212, 213 and an input / output interface 214. The at least one processor 212, 213 may be coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects. The software code 215 may be stored in the ROM 211b. The control apparatus 200 may be interconnected with another control apparatus 200 controlling another function of the 5G (R)AN or the 5GC. In some embodiments, each function of the (R)AN or the 5GC comprises a control apparatus 200. In alternative embodiments, two or more functions of the (R)AN or the 5GC may share a control apparatus. Fig. 3 illustrates an example of a UE 300, such as the UE illustrated on Fig. 1. The UE 300 may be provided by any device capable of sending and receiving radio signals. Nonlimiting examples comprise a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device or any combinations of these or the like. The UE 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on. The UE 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Fig. 3 transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device. The UE 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302a. The processor, storage and other relevant control apparatus can be provided on an appropriate circuit board and / or in chipsets. This feature is denoted by reference 304. The device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device. Fig. 4 shows a UE, such as the UE illustrated on Fig. 1, in dual connectivity with a master gNB and a secondary gNB. The UE may communicate with the master gNB via a primary cell (PCell) and one or more secondary cell (SCell) of a master cell group (MCG). The UE may communicate with the secondary gNB via a primary cell (PSCell) and one or more secondary cell (SCell) of a secondary cell group (SCG). One or more aspect of this disclosure relates to determining whether a cell (e.g. PSCell or SCell) is known. Determining whether a cell is known may be a condition for performing a random access channel (RACH) less access to the cell. If a cell is known, a UE may perform a RACH less access to the cell. If a cell is not known, a UE may not perform a RACH less access to the cell. Fig. 5 shows a timeline of a method for determining whether a PSCell is known. Initially, a UE may be in single connectivity with a master gNB via a PCell. The PCell may be configured (i.e. the PCell is selected to be a serving cell) and activated (i.e. the PCell is used to transmit or received data to the master gNB). The UE may receive, from the master gNB on the PCell, a measurement configuration. The UE may use the measurement configuration to perform for example radio link monitoring (RLM) and bean failure detection (BFD) and other measurements. The UE may detect a signal on the PCell and collect first measurements of the signal for the PCell. The signal may comprise a channel state information reference signal (CSI-RS) or a synchronization signal block (SSB). The first measurements may comprise layer 3 measurements. It will be understood that because the PCell is a serving cell, the first measurements may be referred to as “intra-frequency measurements”. The UE may additionally use the measurement configuration to perform measurements on neighbouring cells of the PCell. These neighbouring cells may be on the same or different carrier than the PCell. The UE may detect a signal for a neighbouring cell which may be a (target) PSCell and collect second measurements of the signal on the (target) PSCell. The signal may comprise at least a synchronization signal block (SSB). The second measurements may comprise layer 3 measurements. It will be understood that because the PSCell is not yet a serving cell, the second measurements may be referred to as “inter-frequency measurements”. The UE may compare the first measurements and the second measurements or compare the second measurements with a threshold and may detect a reporting event being fulfilled (e.g. second measurements better than the first measurements by an offset). The UE may send, to the master gNB on the PCell, a measurement report including the second measurements. The UE may start a TfjVeseconds timer. The timer TfjVeseconds may be stopped after five seconds (or another duration in which case the timer TfjVe seconds can be renamed). The UE may receive, from the master gNB on the PCell, a command or configuration to configure the PSCell. The UE may configure the PSCell. The PSCell is now a serving cell. The UE may continue to detect a signal for the PSCell and collect second measurements of the signal on the PSCell. In this example the PSCell is configured and deactivated. It will be understood that because the PSCell is now a serving cell, the second measurements may be referred to as “intra-frequency measurements”. The UE may receive, from the master gNB on the PCell, a command to activate the PSCell. According to RAN2, the UE may activate the PSCell. The UE may perform a RACH procedure to access the PSCell. The UE may acquire a timing advance (TA). The UE may start a timing advance timer (TAT). The UE may monitor a physical downlink control channel (PDCCH) of the PSCell and may receive uplink and / or downlink scheduling grants. The UE may transmit or receive data on a physical uplink shared channel (PUSCH) or a physical downlink shared channel (PDSCH) of the PSCell based on the scheduling grant. The UE may only transmit when having the TA. The UE may receive, from the master gNB on the PCell, a command to deactivate the PSCell. The UE may deactivate the PSCell. The UE may stop monitoring the PDCCH of the PSCell and may stop receiving uplink and / or downlink scheduling grants. The UE may stop transmitting or receiving data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the TA. The UE may receive, from the master gNB on the PCell, a command to (re)activate the PSCell. The UE may determine whether the PSCell is known based for example on whether the TAT is running. Other or additional conditions may also be applied (e.g. radio link failure has not occurred or beam failure has not been detected). If the TAT is running, the UE may determine that the PSCell is known and the UE may perform a RACH less access to the PSCell. The UE may transmit, to the master gNB on the PSCell, data based on the previously acquired TA. If the TAT is not running (i.e. expired), the UE may determine that the PSCell is not known and the UE may not perform a RACH less access to the PSCell. The UE may perform a RACH-based access to the PSCell, that is the UE may perform a RACH procedure to access the PSCell. The UE may acquire a new TA. The UE may monitor the PDCCH of the PSCell and may receive uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and including possibly the new TA. According to RAN4, the UE may activate the PSCell. The UE may perform a RACH procedure to access the PSCell. The UE may acquire a TA. The UE may start a TAT. The UE may monitor the PDCCH of the PSCell and may receive uplink and / or downlink scheduling grants. The UE may transmit and / or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the TA after a PSCell activation delay. The UE may receive, from the master gNB on the PCell, a command to deactivate the PSCell. The UE may deactivate the PSCell. The UE may stop monitoring the PDCCH of the PSCell and may stop receiving uplink and / or downlink scheduling grants. The UE may stop transmitting or receiving data on the PUSCH or the PDSCH of the PSCell based on the scheduling grant. The UE may only transmit when having the the TA. The UE may receive, from the master gNB on the PCell, a command to (re)activate the PSCell. The UE may either operate according to RAN2 or according to RAN4. The UE may determine whether the PSCell is known based on whether the UE has sent a measurement report (including the second measurements) during the last five second before receiving the command to activate the PSCell (i.e. whether the Tfive seconds timer is running), whether a SSB of the PScell is still detectable when receiving the command to activate the PSCell and whether a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell. If the UE has sent a measurement report during the last five seconds before receiving the command to activate the PSCell (i.e. the TfjVe seconds timer is running), a SSB of the PScell is still detectable when receiving the command to activate the PSCell and a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell, the UE may determine that the PSCell is known and the UE may perform a RACH-less access to the PSCell. The UE may monitor the PDCCH of the PSCell and may receive uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the previously acquired TA after a PSCell activation delay. If the UE has not sent a measurement report during the last five second before receiving the command to activate the PSCell (i.e. the TfiVe seconds timer is not running), even if a SSB of the PScell is still detectable when receiving the command to activate the PSCell and a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell, the UE may determine that the PSCell is not known and the UE may not perform a RACH less access to the PSCell. The UE may perform a RACH procedure to access the PSCell and may acquire a new TA. The UE may monitor the PDCCH of the PSCell and may receive uplink or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the new TA after a PSCell activation delay. A problem arising from the above is that RAN2 and RAN4 specifications may be conflicting (i.e. contradictory). In some scenarios, a UE may determine that the PSCell is known according to RAN2 conditions and is not known according to RAN4 conditions. For example, when the UE receives the command to activate the PSCell more than five seconds after sending the measurement report but whilst the TAT is running (and other conditions are fulfilled), the UE may determine that the PSCell can be activated using RACH-less access according to RAN2 but may determine that the PSCell is not known according to RAN4 (and hence the UE behaviour is not defined). One or more aspects of this disclosure provide solutions to the above problem. One or more aspects of this disclosure provide solutions that may or may not be implemented by modifying RAN4 specifications, in particular 3GPP TS 38.133 clause 8.17.2 (v17.11.0) which currently reads: “In FR2, the PSCell is known if it has been meeting the following conditions: During the last 5 seconds before the reception of the SCG activation command: - the UE has sent a valid measurement report for the PSCell being activated and - One of the SSBs measured from the PSCell being activated remains detectable according to the cell identification conditions specified in clause 9.3. - One of the SSBs measured from PSCell being activated also remains detectable during the PSCell activation delay Tacwationjime according to the cell identification conditions specified in clause 9.3. otherwise it is unknown". A solution may be to keep the “five seconds” condition for a first command to activate the PSCell (or SCG) and to remove the “five seconds” condition for a subsequent command(s) to activate the PSCell (or SCG) to read. This solution may or may not be implemented by modifying 3GPP TS 38.133 clause 8.17.2 (v17.11.0) to read, for example, as follows. “In FR2, the PSCell is known if it has been meeting the following conditions: For the initial SCG activation command: During the last 5 seconds before the reception of the SCG activation command: the UE has sent a valid measurement report for the PSCell being activated and One of the SSBs measured from the PSCell being activated remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being activated also remains detectable during the PSCell activation delay Tactivation_time according to the cell identification conditions specified in clause 9.3. otherwise, if this is not the initial SCG activation command: One of the SSBs measured from the PSCell being activated remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being activated also remains detectable during the PSCell activation delay Tactivation time according to the cell identification conditions specified in clause 9.3. otherwise it is unknown. Another solution may be to keep the “five seconds” condition for a first command to configure the PSCell (or SCG) and to remove the “five seconds” condition for a subsequent command to configure the PSCell (or SCG) to read. This solution may or may not be implemented by modifying 3GPP TS 38.133 clause 8.17.2 (v17.11.0) to read, for example, as follows.. “In FR2, the PSCell is known if it has been meeting the following conditions: For the initial SCG configuration command: During the last 5 seconds before the reception of the SCG configuration command: the UE has sent a valid measurement report for the PSCell being configured and One of the SSBs measured from the PSCell being configured remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being configured also remains detectable during the PSCell activation delay Tactivation_time according to the cell identification conditions specified in clause 9.3. otherwise, if this is not the initial SCG configuration command: One of the SSBs measured from the PSCell being configured remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being configured also remains detectable during the PSCell activation delay Tactivation time according to the cell identification conditions specified in clause 9.3. otherwise it is unknown. Another solution may be to keep the “five second” condition for a command to activate the PSCell (or SCG) when a timer Tknown is running and to remove the “five second” condition for a command to activate the PSCell (or SCG) when a timer Tknown is not running. This solution may or may not be implemented by modifying 3GPP TS 38.133 clause 8.17.2 (v17.11.0) to read, for example, as follows. “In FR2, the PSCell is known if it has been meeting the following conditions: If Tknown is running: During the last 5 seconds before the reception of the SCG activation command: the UE has sent a valid measurement report for the PSCell being activated and One of the SSBs measured from the PSCell being activated remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being activated also remains detectable during the PSCell activation delay Tactivation_time according to the cell identification conditions specified in clause 9.3. otherwise, if Tknown is not running: One of the SSBs measured from the PSCell being activated remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being activated also remains detectable during the PSCell activation delay Tactivation time according to the cell identification conditions specified in clause 9.3. otherwise it is unknown Where: Tknown is the timer started when the UE sent a valid measurement report for the PSCell being activated. When the PSCell is activated, Tknown is stopped”. Another solution may be to keep the “five seconds” condition for a command to configure the PSCell (or SCG) when a timer Tknown is running and to remove the “five seconds” condition for a command to configure the PSCell (or SCG) when a timer Tknown is not running. This solution may or may not be implemented by modifying 3GPP TS 38.133 clause 8.17.2 (v17.11.0) to read, for example, as follows. “In FR2, the PSCell is known if it has been meeting the following conditions: If Tknown is running: During the last 5 seconds before the reception of the SCG configuration command: the UE has sent a valid measurement report for the PSCell being configured and One of the SSBs measured from the PSCell being configured remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being configured also remains detectable during the PSCell activation delay Tactivation_time according to the cell identification conditions specified in clause 9.3. otherwise, if Tknown is not running: One of the SSBs measured from the PSCell being configured remains detectable according to the cell identification conditions specified in clause 9.3. One of the SSBs measured from PSCell being activated also remains detectable during the PSCell activation delay Tactivation time according to the cell identification conditions specified in clause 9.3. otherwise it is unknown Where: Tknown is the timer started when the UE sent a valid measurement report for the PSCell being activated. When the PSCell is activated. Tknown is stopped”. Another solution may be to only have a “timer Tknown” condition to read, for example, as follows. This solution may or may not be implemented by modifying 3GPP TS 38.133 clause 8.17.2 (v17.11.0) to read, for example, as follows. “In FR2, the PSCell is known if it has been meeting the following conditions: If Tknown is running otherwise it is unknown Where: Tknown is the timer started when the UE sent a valid measurement report for the PSCell being activated. When the PSCell is activated, Tknown is stopped”. Fig. 6 shows a timeline of a method for determining whether a primary cell of a secondary cell group is known. Initially, a UE may be in single connectivity with a master gNB via a PCell. The PCell may be configured (i.e. the PCell is selected to be a serving cell) and activated (i.e. the PCell is used to transmit or received data to the master gNB). The UE may receive, from the master gNB on the PCell, a measurement configuration. The UE may use the measurement configuration to perform for example radio link monitoring (RLM) and bean failure detection (BFD) and other measurements. The UE may detect a signal on the PCell and collect first measurements of the signal for the PCell. The signal may comprise a channel state information reference signal (CSI-RS) or a synchronization signal block (SSB). The first measurements may comprise layer 3 measurements. It will be understood that because the PCell is a serving cell, the first measurements may be referred to as “intra-frequency measurements”. The UE may additionally use the measurement configuration to perform measurements on neighbouring cells of the PCell. These neighbouring cells may be on the same or different carrier than the PCell. The UE may detect a signal for a neighbouring cell which may be a (target) PSCell and collect second measurements of the signal on the (target) PSCell. The signal may comprise at least a synchronization signal block (SSB). The second measurements may comprise layer 3 measurements. It will be understood that because the PSCell is not yet as serving cell, the second measurements may be referred to as “inter-frequency measurements”. The UE may compare the first measurements and the second measurements or compare the second measurements with a threshold and may detect a reporting event being fulfilled (e.g. second measurements better than the first measurements by an offset). The UE may send, to the master gNB on the PCell, a measurement report including the second measurements. The UE may start a TfjVe seconds and a Tknown timer. The timer Tfive seconds may be stopped after five seconds (or another duration in which case the timer Tfive seconds can be renamed). The timer Tknown timer may be stopped after receiving a command to activate the PSCell. The UE may receive, from the master gNB on the PCell, a command or configuration to configure the PSCell. The UE may configure the PSCell. The PSCell is now a serving cell. The UE may continue to detect a signal for a (target) PSCell and collect second measurements of the signal on the PSCell. In this example the PSCell is configured and deactivated. It will be understood that because the PSCell is now a serving cell, the second measurements may be referred to as “intra-frequency measurements”. The UE may receive, from the master gNB on the PCell, a command to activate the PSCell. According to a proposed RAN4, the UE may activate the PSCell. The UE may perform a RACH procedure to access the PSCell. The UE may acquire a TA. The UE may monitor the PDCCH of the PSCell and may receive an uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the TA after a PSCell activation delay. The UE may receive, from the master gNB on the PCell, a command to deactivate the PSCell. The UE may deactivate the PSCell. The UE may stop monitoring the PDCCH of the PSCell and may stop receiving an uplink and / or downlink scheduling grants. The UE may stop transmitting or receiving data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the TA. The UE may receive, from the master gNB on the PCell, a command to (re)activate the PSCell. The UE may determine whether the PSCell is known based on whether the timer Tknown is running, whether the UE has sent a measurement report during the last five second before receiving the command to activate the PSCell (i.e. whether the TfjVe seconds timer is running), whether a SSB of the PScell is still detectable when receiving the command to activate the PSCell and whether a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell. If the timer Tknown is running, the UE has sent a measurement report during the last five seconds before receiving the SCG command to activate the PSCell (i.e. the Tnveseconds timer is running), a SSB of the PScell is still detectable when receiving the command to activate the PSCell and a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell, the UE may determine that the PSCell is known and the UE may perform a RACH less access to the PSCell. The UE may monitor the PDCCH of the PSCell and may receive uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the previously acquired TA after a PSCell activation delay. If the timer Tknown is not running, a SSB of the PScell is still detectable when receiving the SCG command to activate the PSCell and a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell, the UE may determine that the PSCell is known and the UE may perform a RACH less access to the PSCell. The UE may monitor the PDCCH of the PSCell and may receive an uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the previously acquired TA after a PSCell activation delay. If the timer Tknown is running and the UE has not sent a measurement report during the last five seconds before receiving the command to activate the PSCell (i.e. the Tfive seconds timer is running), a SSB of the PScell is not detectable when receiving the command to activate the PSCell or a SSB is not detectable during a PSCell activation delay after receiving the command to activate the PSCell, the UE may determine that the PSCell is not known and the UE may not perform a RACH less access to the PSCell. The UE may perform a RACH procedure to access the PSCell and may acquire a new TA. The UE may monitor the PDCCH of the PSCell and may receive an uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the new TA after a PSCell activation delay. If the timer Tknown is not running and a SSB of the PScell is not detectable when receiving the command to activate the PSCell or a SSB is not detectable during a PSCell activation delay after receiving the command to activate the PSCell, the UE may determine that the PSCell is not known and the UE may not perform a RACH less access to the PSCell. The UE may perform a RACH procedure to access the PSCell and may acquire a new TA. The UE may monitor the PDCCH of the PSCell and may receive uplink and / or downlink scheduling grants. The UE may transmit or receive data on the PUSCH or the PDSCH of the PSCell based on the scheduling grants and the new TA after a PSCell activation delay. Thanks to the above, conflicting scenarios where a UE may determine that the PSCell is known according to RAN2 and is not known according to RAN4 may be avoided. For example, when the UE receives the command to activate the PSCell more than five seconds after sending the measurement report but whilst the TAT is running, the UE may determine that the PSCell is known according to RAN 2 and may determine that the PSCell is known according to the proposed RAN4. In the above the Tknown timer is used by the UE to determine whether a command to activate the PSCell is a first command to activate the PSCell (i.e. the Tknown timer is running) or a subsequent command to (re)activate the PSCell (i.e. the Tknown timer is not running). The “five seconds” condition applies for the first command to activate the PSCell and does not apply for the subsequent command to (re)activate the PSCell to read. It will be understood that this concept may be generalized and that the Tknown timer is one specific implementation but other implementations may be used. For example, the UE may keep track whether a command to activate the PSCell is a first command to activate the or a subsequent command to (re)activate the PSCell. In the above the conditions to determine whether the PSCell is known are defined in relation to the command to activate the PSCell. It will be understood the conditions to determine whether the PSCell is known may be defined in relation to the command to configure the PSCell. In the above the conditions to determine whether the PSCell is known comprise whether the timer Tknown is running, whether the UE has sent a measurement report during the last five second before receiving the command to activate the PSCell (i.e. whether the Tfjveseconds timer is running), whether a SSB of the PScell is still detectable when receiving the command to activate the PSCell and whether a SSB is still detectable during a PSCell activation delay after receiving the command to activate the PSCell. It will be understood that the conditions to determine whether the UE is known may be simplified and may only comprise whether the timer Tknown is running. That is, if the timer Tknown is running, the UE may be known. If the timer Tknown is not running, the UE may not be known. In the above, the Tknown timer is started in response to transmitting, to the master gNB, the measurement report. It will be understood that the Tknown timer may be started in response to an additional or alternative event. For example, Tknown timer may be started in response to receiving the SCG command to deactivate the cell. In the above, the UE may determine whether the PSCell is known. It will be understood that the UE may whether a SCell of the MCG or a SCell of the SCG known is known in a similar manner. Fig. 7 shows a block diagram of a method for determining whether a cell is known. At step 700, a UE may receive a command to configure or activate a cell. At step 702, the UE may determine (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell. At step 704, the UE may determine whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running. Fig. 8 shows a block diagram of a method for determining whether a PSCell is known. At step 800, a UE may receive a command to activate a PSCell. At step 802, the UE may determine (i) whether the command is a first command to activate the PSCell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the PSCell and stopped in response to receiving a command to activate PSCell. At 804, the UE may determine whether the PSCell is known based on determining (i) whether the command is a first command to activate the PSCell or (ii) whether the timer is running. Fig. 9 shows a schematic representation of non-volatile memory media 900 storing instructions which when executed by a processor allow the processor to perform one or more of the steps of the methods of Fig. 7 and Fig. 8. It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention. It will be understood that although the above concepts have been discussed in the context of a 5GS, one or more of these concepts may be applied to other cellular systems. The embodiments may thus vary within the scope of the attached claims. In general, some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. The embodiments may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures, e g., as in Fig. 7 and Fig. 8, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi-core processor architecture, as non-limiting examples. Alternatively or additionally some embodiments may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and / or method steps previously described. That circuitry may be provided in the base station and / or in the communications device. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analogue and / or digital circuitry); (b) combinations of hardware circuits and software, such as: (i) a combination of analogue and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. 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 also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example integrated device. The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of some embodiments However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

1. An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:receive a command to configure or activate a cell;determine (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; anddetermine whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is running.

2. The apparatus of claim 1, wherein the at least one memory stories instructions that, when executed by the at least one processor, cause the apparatus at least to:receive a command to configure or activate a cell;determine (i) that the command is a first command to configure or activate the cell or (ii) that the timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; anddetermine that the cell is known based on determining (i) that the command is a first command to configure or activate the cell or (ii) that the timer is running.

3. The apparatus of claim 2, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to activate the cell;determine that the timer is running; and determine that the cell is known.

4. The apparatus of claim 3 wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to activate the cell;determine that the timer is running;determine that during a first time period before receiving the command to activate the cell a measurement report for the cell has been sent by the apparatus;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

5. The apparatus of claim 2, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to configure the cell;determine that the timer is running; anddetermine that the cell is known.

6. The apparatus of claim 5 wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to configure the cell;determine that the timer is running ;determine that during a first time period before receiving the command to configure the cell, a measurement report for the cell has been sent;determine that a synchronization signal block of the cell is detected;determine that during a second time period after receiving the command to configure the cell a synchronization signal block of the is detected by the apparatus; anddetermine that the cell is known.

7. The apparatus of claim 2, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to activate the cell;determine that the command is a first command to activate the cell;determine that during a first time period before receiving the command to activate the cell a measurement report for the cell has been sent by the apparatus;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

8. The apparatus of claim 2 wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to configure the cell;determine that the command is a first command to configure the cell;determine that during a first time period before receiving the command to configure the cell, a measurement report for the cell has been sent by the apparatus;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to configure the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

9. The apparatus of claim 1, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive a command to configure or activate a cell;determine (i) that the command is not a first command to configure or activate the cell or (ii) that the timer is not running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving a command to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; anddetermine that the cell is known based on determining (i) that the command is not a first command to configure or activate the cell or (ii) that the timer is not running.

10. The apparatus of claim 9, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to activate the cell;determine that the command is not a first command to activate the cell;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

11. The apparatus of claim 9, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to configure the cell;determine that the command is not a first command to configure the cell;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

12. The apparatus of claim 9, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to activate the cell;determine that the timer is not running ;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to activate the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

13. The apparatus of claim 9, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:receive the command to configure the cell;determine that the timer is not running ;determine that a synchronization signal block of the cell is detectable by the apparatus;determine that during a second time period after receiving the command to configure the cell a synchronization signal block of the cell is detectable by the apparatus; anddetermine that the cell is known.

14. The apparatus of any of claims 4 to 8, wherein the first time period is a five second time period.

15. The apparatus of any of claims 4, 6 to 8 or 10 to 13, wherein the second time period is an activation delay.

16. The apparatus of any of claims 1 to 15, wherein the command is a secondary cell group command; andthe cell is a primary cell of the secondary cell group or a secondary cell of the secondary cell group.

17. The apparatus of any of claims 1 to 15, wherein the command is a master cell group command; andthe cell is a primary cell of the master cell group or a secondary cell of the master cell group.

18. The apparatus of any of claims 1 to 17, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to:perform a random access channel less procedure with the cell.

19. The apparatus of any of claims 1 to 18, wherein determining that the cell is known comprises changing a state of the cell from unknown to known.

20. The apparatus of any of claims 1 to 19, wherein the command to configure or activate the cell is received on a primary cell of a master cell group.

21. The apparatus of claim 20, wherein the measurement report is sent on the primary cell of the master cell group.

22. The apparatus of any of claims 1 to 21, wherein the apparatus is a user equipment23. The apparatus of any of claims 1 to 22, wherein the apparatus operates in FR2.

24. A method comprising:receiving a command to configure or activate a cell;determining (i) whether the command is a first command to configure or activate the cell or (ii) whether a timer is running, wherein the timer is configured to be started in response to sending a measurement report for the cell or in response to receiving acommand to deactivate the cell and stopped in response to receiving a command to configure or activate the cell; anddetermining whether the cell is known based on determining (i) whether the command is a first command to configure or activate the cell or (ii) whether the timer is5 running.

25. A computer program comprising computer executable instructions which when run on one or more processors perform the steps of the method of claim 24.

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