Providing system information

Abstract

An apparatus and method are provided for enabling a communication device in a cell of a network to access the cell based on system information received from the network. A communication device receives a dedicated control message for releasing the communication device from a cell, the message including system information for storage in a memory of the communication device for use in accessing the cell when system information provided by a network is unavailable in the cell, the dedicated control message indicating that the system information is not transmitted in the cell. The apparatus stores the system information received in the dedicated control message in a memory, and then performs an operation for accessing the cell based on the stored system information.

Description

Technical Field

[0001] The present disclosure relates to methods, apparatus, and computer program products for providing a device with system information for accessing a communication system. Background Art

[0002] Data can be transmitted between a communication device (such as a user or other terminal device) and a network entity (such as a base station / access point and / or other network node) in a communication system. An access network generally provides access to a communication system to a device. The access network is provided with appropriate signal receiving and transmitting means to enable communication and enable the device to access the communication system. In a mobile or wireless communication system, at least a portion of the data communication between at least two devices occurs over a wireless or radio link. Examples of wireless systems include public land mobile networks (PLMNs), satellite-based communication systems, and different wireless local area networks, such as wireless local area networks (WLANs).

[0003] The communication system can be accessed by means of an appropriate wireless communication device, generally referred to as a user equipment (UE). The user's communication device can receive signaling through a node (e.g., a base station) at the radio access network and send and / or receive communications accordingly. Communications may include, for example, communications such as voice, video, electronic mail (email), text messages, multimedia and / or content data, etc. Non-limiting examples of services include two-way or multi-way calls, data communications, multimedia services, and access to data network systems such as the Internet.

[0004] Control information can be multicast / broadcast to wireless devices. Broadcast refers to the ability to transmit information to multiple users in a broadcast area. Broadcasting can include signaling control information such as system information (SI) to devices in a service area. The devices can then use the broadcast system information for accessing the communication system.

[0005] A communication system and associated equipment typically operate according to a given standard or specification that sets out what the various entities associated with the system are allowed to do and how it should be achieved. Communication protocols and / or parameters that will be used to access the system and communicate are also typically defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology and the so-called fifth generation (5G) or new radio (NR) networks. 5G is being standardized by the 3rd Generation Partnership Project (3GPP).

[0006] It would be desirable to reduce energy consumption of communication networks and devices. This may be particularly desirable in access operations, such as accessing a radio access network (RAN). Access operations and maintaining access readiness use resources on both the network and the device, and may contribute to a significant portion of the total energy consumption. Summary of the invention

[0007] According to one aspect, an apparatus for a communication device is provided, comprising at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least: receive a dedicated control message for releasing the communication device from a cell, the message comprising system information for storage in the memory of the communication device for use in accessing the cell when system information provided by a network is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, store the system information received in the dedicated control message in the memory, and perform an operation for accessing the cell based on the stored system information.

[0008] According to one aspect, a network device is provided, comprising at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the network device to at least: send a dedicated control message for releasing the communication device from the cell to a communication device in a cell, to be stored in the communication device for use in accessing the cell when system information provided by a network is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, and to allow the communication device to access the cell based on the stored system information.

[0009] The system information may be included in a radio resource control (RRC) release message.

[0010] The system information may be included in a message received by the communication device for releasing the communication device from a last cell used by the communication device.

[0011] The communication device may be configured to obtain the stored system information when in an idle state or an inactive state.

[0012] The system information received in the dedicated control message may include system information broadcast by the cell in the cell when the cell is in an operation mode in which system information is transmitted in the cell.

[0013] The system information may include at least one of the following information: paging configuration, random access channel configuration, cell reselection configuration, small data transmission configuration and / or unified access control configuration.

[0014] The system information included in the dedicated control message may include information content of a system information block (SIB), a master information block (MIB) and / or a synchronization signal block (SSB). The system information may include information content in a system information block 1 (SIB1).

[0015] According to one aspect, a method in a communication device is provided, comprising: receiving a dedicated control message for releasing the communication device from a cell, the message including system information for storage in a memory of the communication device for use in accessing the cell when system information provided by a network is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, storing the system information received in the dedicated control message in the memory, and performing an operation for accessing the cell based on the stored system information.

[0016] According to one aspect, a method for a network device is provided, comprising: sending a dedicated control message for releasing the communication device from the cell to a communication device in a cell, to be stored in the communication device for use in accessing the cell when system information provided by the network is not available in the cell, the dedicated control message indicating that system information is sent in the cell, and allowing the communication device to access the cell based on the stored system information.

[0017] The method may include sending and / or receiving the system information in a Radio Resource Control (RRC) release message.

[0018] The method may comprise sending and / or receiving the system information in a message releasing the communication device from a last cell used by the communication device.

[0019] The method may include: the communication device obtaining the stored system information when in an idle state or an inactive state.

[0020] 15. The system information may include: when the cell is in an operation mode in which system information is not sent in the cell, the system information broadcast by the cell in the cell. The system information may include information of at least one of the following: paging configuration, random access channel configuration, cell reselection configuration, small data transmission configuration and / or unified access control configuration. The system information may be included in the dedicated control message, including the information content of a system information block (SIB), a master information block (MIB) and / or a synchronization signal block (SSB). The system information may include the information content of a system information block 1 (SIB1).

[0021] According to certain aspects, the apparatus is configured to transition between operation in which system information is broadcast in a cell and operation in which system information is not broadcast in the cell.

[0022] According to an aspect, an indication is provided in a master information block (MIB) that system information block (SIB) information enabling access to the cell is not broadcast in the cell.

[0023] The device may be configured to acquire system information from the network in response to one of network notification, cell reselection, handover, and expiration of a timer.

[0024] The apparatus in the network may be configured to, in response to determining that transmission of system information in a cell is unnecessary, signal an indication that system information is not to be transmitted in the cell and / or refrain from broadcasting system information in the cell.

[0025] Devices in the cell may be configured to use the stored system information for accessing the cell, rather than treating the cell as barred, in response to receiving an indication that system information is not to be provided for the cell.

[0026] Devices in a cell may be configured to perform an on-demand system information block (SIB) procedure when a system information block enabling access to the cell is not broadcast in the cell.

[0027] A device for implementing the operations and functions disclosed herein may also be provided. The device may include appropriately configured hardware and software.

[0028] A computer software product covering at least part of the functionality described herein may also be provided.According to one aspect, a computer program comprises instructions for performing at least one of the methods described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Some aspects will now be described in more detail, by way of example only, with reference to the following examples and accompanying drawings, in which:

[0030] Figure 1 illustrates an example of a communication system in which the present invention may be practiced;

[0031] Figure 2 A data processing apparatus is shown; and

[0032] Figures 3 to 12 is a flow chart according to certain illustrative examples. DETAILED DESCRIPTION

[0033] The following description gives an exemplary description of some possibilities for practicing the present invention. Although the specification may refer to "an", "one" or "some" examples or embodiments in several places in the text, this does not necessarily mean that each reference is to the same example of (multiple) embodiments, or that a particular feature applies only to a single example or embodiment. Individual features of different examples and embodiments may also be combined to provide other embodiments.

[0034] A wireless communication system can provide mobile communications to devices connected therein. Typically, an access point, such as a base station, is provided for enabling communications for devices connected to the access point. In the following, different scenarios will be described using the 3GPP 5G radio architecture as an example of an access architecture. However, the embodiments are not necessarily limited to this architecture. Some examples of options for suitable systems are Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long Term Evolution (LTE), LTE-A (LTE Advanced), Wireless Local Area Network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth Personal Communications Service (PCS), Wideband Code Division Multiple Access (WCDMA), systems using Ultra-Wideband (UWB) technology, sensor networks, mobile ad hoc networks (MANET), cellular Internet of Things (IoT) RAN and Internet Protocol Multimedia Subsystem (IMS) or any combination and further development thereof. The principles can also be applied to any next generation access system.

[0035] Figure 1 A schematic example of a communication system 1 including a radio access system or radio access network (RAN) 2 is shown. The radio access network may include one or more access points, or base stations 11, 12, and 13. The base station may provide one or more cells 14 serving wireless communication devices or user equipment (UE) 15. These terms are used interchangeably throughout the specification. An access point may include any node capable of transmitting / receiving radio signals (e.g., a 3GPP5G base station such as a gNB, eNB, a user equipment providing a hotspot, a Tx / Rx point (TRP), etc.). A large number of radio access networks may be provided in the communication system. The radio access network may include multiple base stations.

[0036] The communication device 15 may be located in the service area of ​​the radio access network 2. For simplicity, only a few devices are shown. The device 15 in the cell 14 may listen and camp on the cell provided by the access points 11 to 13. Camping on a cell refers to a state in which the device stays on the cell and is ready to initiate a potential dedicated service or receive an ongoing broadcast service.

[0037] Figure 1Also shown is a control function entity 10. This may include a suitable controller at the network, which is configured to control one or more of the access nodes 11, 12 and 13. As described below, the control function entity 10 may also be configured to control the delivery of system information to the device 15 in the cell. Non-limiting examples of possible network control functions include a medium access control (MAC) entity and / or a radio resource control (RRC) entity.

[0038] It should be noted that the wider communication system is shown only as cloud 1 and may include multiple elements not shown for clarity. For example, various operations and functions according to a 5G-based system may be included in a terminal or user equipment (UE), a 5G radio access network (5GRAN) or a next generation radio access network (NG-RAN), a 5G core network (5GC), one or more application functions (AF), and one or more data networks (DN). 5G-RAN may include one or more gNodeBs (gNBs) connected to one or more gNodeB centralized cell functions or one or more gNodeB distributed cell functions. 5GC may also include entities such as a network slice selection function (NSSF); a network exposure function; a network repository function (NRF); a policy control function (PCF); a unified data management (UDM); an application function (AF); an authentication server function (AUSF); an access and mobility management function (AMF); various session management functions (SMFs), and the like.

[0039] The communication device 15 can be any suitable device suitable for wireless communication. Non-limiting examples include a mobile station (MS) (e.g., a mobile device such as a mobile phone or a so-called "smart phone"), a computer configured with a wireless interface card or other wireless interface device (e.g., a USB dongle), a personal data assistant (PDA) or a tablet computer configured with wireless communication functionality, a machine type communication (MTC) device, an Internet of Things (IoT) type communication device, a cellular Internet of Things (CIoT) device, or any combination of these devices, etc. The device can be provided as part of another device. The device can receive signals via an air or radio interface via an appropriate device for receiving, and can transmit signals via an appropriate device for transmitting radio signals. Communication can be performed via multiple paths. The communication device can be provided with carrier aggregation (CA) and the ability of wireless communication via component carriers (CC). In order to achieve multiple input multiple output (MIMO) type, the communication device can be provided with multiple antenna elements.

[0040] Devices such as base stations, terminal devices and network functions are equipped with data processing means including at least one processor and at least one memory. Figure 1An example of a data processing device 20 for a network controller entity 10 is shown. Figure 2 Shown for Figure 1 An example of a data processing device 50 of the communication device 15.

[0041] The data processing device typically comprises processor(s) 22 , 52 , 53 and memory(s) 21 and 51 . Figure 2 Connections between elements of the device are also shown. An interface 54 for connecting the data processing device to other components of the device is also shown. The at least one memory may include at least one ROM and / or at least one RAM. The communication device may include other possible components for software and hardware to assist in performing the tasks it is designed to perform, including implementing the features described herein related to processing system information and tasks related to access based on system information processing. The at least one processor may be coupled to the at least one memory. The at least one processor may be configured to execute appropriate software code to implement one or more of the following aspects. The software code may be stored in at least one memory.

[0042] Certain aspects, configurations, and signaling of system information (SI) are described below. Signaling of system information (SI) may be provided via broadcast, where control information is transmitted simultaneously from a single source to multiple destinations / devices in an area. Broadcast refers to the ability to transmit information to all users in an area as a collection of one or more network access nodes (e.g., base stations) and / or cells that are capable of delivering the same information.

[0043] exist Figure 1 , signaling of system information from the access node 11 to one of the devices 15 is shown by arrow 16, and possible subsequent communication by the UE is shown by arrow 17. A base station 11 of the access network may broadcast system information (SI) to the UEs 15 in the cell in elements such as synchronization signal blocks / system information blocks (SSB / SIB).

[0044] Broadcasts can be frequent and cause considerable resource usage and energy consumption. The reason for this is that the network needs to wake up periodically to send certain SIBs to ensure that any new UE entering the cell can reside on the cell. If necessary, the SIB may include SIB1 and any one of SIB2 to SIB5. SIB1 is a cell-specific information element valid only for the serving cell and carries the key information required for the UE to access the cell. SIB1 contains information relevant to evaluating whether the UE is allowed to access the cell, and may also include information related to the availability and scheduling of other system information, such as other SIBs, such as mapping of SIBs to system information messages, periodicity, SI window size, etc. SIB1 also contains radio resource configuration information common to all UEs and prohibition information applied to unified access control. SIB2 to SIB5 elements may contain further information, such as cell reselection information.

[0045] System information is needed because it provides the UE with the parameters required to access the network and detect paging messages. For New Radio (NR), random access channel (RACH) based on on-demand system information is supported, however, SIB1 messages are not included in RACH because it is the broadcast SIB1 information that provides the RACH configuration required to access the cell.

[0046] There are situations where frequent broadcasting of system information may not be necessary and may result in inefficient use of resources. For example, for certain areas and / or certain time periods and / or most of the time in an application, there may be no new UEs or SIB updates. Such examples are nighttime, weekends and / or public holidays in areas with offices, schools and other similar places.

[0047] It is possible to identify times and periods when SIBs do not need to be sent frequently and utilize these times and periods to reduce energy consumption by avoiding the transmission of SIBs. This mode of operation is referred to as SIB-less mode operation hereinafter. The SIB-less mode can be provided in both time domain and frequency domain techniques.

[0048] According to one possible operation mode, other SSBs are transmitted, but the operation is SIB1-free, ie, no SIB1 is transmitted in the cell. According to another possible operation mode, neither SSBs nor SIB1 are transmitted in the cell. This mode can be used to further improve power saving.

[0049] The problem in SIB-free operation is how to provide the necessary paging / RACH configuration to the UE. If the cell operates in SIB-free mode, the legacy UE is prevented from staying on the cell. The legacy UE here refers to a device that cannot be or is not configured for SIB-free mode operation. In the context of SIB-free operation and 3GPP specifications, the legacy UE in the following example refers to a UE configured according to 3GPP Release 17 and earlier. The legacy UE can obtain the necessary SIBs from the broadcast. The legacy UE can also re-acquire the SIB in response to the SI modification notification. An indication that they are prohibited from the cell can be provided to the legacy UE. This can be provided, for example, by a cellbarred indication in the MIB. Subsequent UEs (i.e., UEs without SIB functionality according to, for example, 3GPP Release 18 and subsequent versions) will also receive the indication. UEs with SIB-free functionality know that the network is operating in SIB-free mode, and UEs with SIB-free functionality can regard the cellbarred indication as redundant and stay in SIB-free cells.

[0050] The cellbarred indication in the MIB may be used in conjunction with other fields in the MIB to indicate to the UE that the network (NW) is in no SIB mode. For example, the MIB messages cellbarred+ssb-SubcarrierOffset or cellbarred+pdcch-ConfigSIB1 may be used in conjunction to indicate that the NW is in no SIB mode. A Release 18 capable UE that is aware of the stored system information may stay in a cell and use the stored system information after the NW has indicated no SIB mode of operation. A non-Release 18 capable UE that does not have knowledge of the stored system information may perform cell reselection / HO to other cells in a manner substantially similar to a legacy UE.

[0051] A mechanism can be provided for transferring from a traditional SIB mode to a SIB-free mode between different modes of SIB operation in a cell. The switching mechanism at the NW enables flexible operation. The operation can be dynamic and responsive to changing conditions in the cell. In this specification, the terms traditional mode of operation, normal mode, and with-SIB mode refer to current SIB operation that requires SIBs from the network to access the network. This operating mode is referred to as the SIB operating mode below. An operating mode in which frequent signaling of SIBs is not required and the network suspends sending system information (more specifically, sending SIBs) is referred to as a SIB-free operating mode.

[0052] Figure 31 is a flow chart of an example of an operation for providing system information for accessing a network to at least one device. At 100, the network transmits system information that enables at least one device to access a cell for storage in a memory of at least one device. The transmission may include broadcasting the system information in the cell. The system information may also be transmitted in a dedicated control information message. At 102, the cell operates in a mode in which the network does not provide system information for the cell. As a result, at least one device in the cell is unable to receive any system information that the at least one user equipment needs for access. At 104, at least one device is allowed to access the cell based on the system information stored in the at least one device.

[0053] Figure 4 An example of operations at a device for accessing a network is shown. At 200, the device receives system information from the network to enable access to a cell. At 202, the system information is stored in a memory of the device for use by the communication device to perform operations for accessing the cell when the network does not provide the system information. Then, at 204, the device in the cell can perform necessary operations for access based on the system information stored in the memory.

[0054] Figure 5 and Figure 6 Examples of methods at a network and a device are respectively shown when the network switches between operation modes in which the network provides system information and in which the network does not provide system information.

[0055] exist Figure 5 In the method, at 300, the network sends system information that enables at least one device to access a cell for storage in a memory of the at least one device. A decision is made to switch from a first operation mode in which system information is sent in the cell to a second operation mode in which system information is not sent in the cell. Then, at 302, the operation mode is changed accordingly. At 304, the network sends an indication of the change to at least one device to inform the at least one device that the cell is operating in the second operation mode. Then, at 306, the at least one device accesses the cell based on the system information stored in the memory of the at least one device.

[0056] Figure 6 An example of operation at a device when a network switches its mode to an operation in which system information is not sent in a cell is shown. In the method, at 400, the device stores system information supporting access to a cell in at least one memory for performing operations to access the cell when system information is not provided in the cell. The device may receive the information, for example, during normal operation of the cell and / or in an RRC message such as an RRC release message.

[0057] Then at 402, the device receives an indication that system information enabling access to the cell is not provided in the cell. Then at 404, the device may operate based on the knowledge of the stored information and the indication of a transition from a first mode of operation of a network providing system information in the cell to a second mode of operation in which system information is not provided in the cell. Then at 406, operations for accessing the cell may be performed based on the system information stored in the at least one memory.

[0058] A more detailed example of achieving operation without frequent system information messages will be described below using the context of SIB-free operation as an example. SIB-free operation can be achieved by configuring the UE to obtain and store in its memory the necessary information required for idle / inactive mode operation in a given cell. This information may include information such as paging / RACH configuration and / or cell reselection and handover configuration.

[0059] According to one possibility, the system information mode in a cell may be switched from SIB mode to SIB-free mode and vice versa by an indication sent in a master information block (MIB). Upon receiving the indication to switch to SIB-free mode, the UE may use the stored system information from its memory. The UE may assume that there will be no further SIB updates during SIB-free mode.

[0060] After the network switches back to SIB mode from SIB-free mode, or if SIB update is required during SIB-free mode, the NW may update the SIB mode indication in another MIB. Reception of another MIB may trigger the UE to reacquire one or more SIBs. According to one possibility, the UE may reacquire one or more SIBs if an SI modification notification is received.

[0061] The network may decide to operate in an operating mode where no system information is transmitted based on various reasons. For example, the network may decide to dynamically apply SIB-free operation based on the traffic load in the cell. For example, in response to determining a very low traffic load, the network may decide to shut down part of its transmission and reception hardware for a period of time for energy saving purposes. The network may decide to turn off the transmission of only SIB information. According to one possibility, the network may decide to turn off the transmission of SSB and SIB1 information. The actual trigger for switching may be network implementation specific. Non-limiting other examples include date and / or time of day, detection of no new UE entering the cell within a predetermined time period, etc.

[0062] The decision regarding the use of an operating mode in which system information is not transmitted may be made by any appropriate controller in the network. For example, a medium access control (MAC) entity and / or an RRC entity may make the decision to move in and out of SIB-free operation. According to a specific example, the RRC entity may make the decision based on input from a MAC entity based on the traffic load in the cell.

[0063] According to a specific example, a SIB1-free mode operation is provided, in which the network prohibits the transmission of SIB1 information of a cell for a period of time. The UE can then use the stored SIB1 information for access in the cell. The UE can request other relevant SIBs from the network via an on-demand mechanism.

[0064] A validity timer may be set for the stored system information. Before the validity timer expires, the stored system information for an operation mode in which the relevant system information is not transmitted may be assumed to be valid. Figure 2 In the data processing device 50 of the present invention, the validity timer function is represented by the reference numeral 55. The corresponding validity timer for the system information stored in the (multiple) devices in the cell can also be operated on the network side to maintain synchronization between the network and the (multiple) devices in the cell. The network can configure the validity timer at the (multiple) device. For example, the configuration information can be provided through MIB or RRC signaling. The validity timer configuration information can be provided in the same message as the indication of switching to the operation of not transmitting system information, or separately.

[0065] Figure 7 An example of the operation of a timer at an access device is shown in . At 500, the device stores system information in at least one memory for accessing a cell when the network operates in a mode in which system information is not available in the cell. At 502, the device starts a timer for the validity of the system information stored in at least one memory. At 504, an operation for accessing the cell is performed based on the stored system information, which is stored until the timer expires. At 506, after the timer expires, the device may send a request for system information of the cell. Alternatively, or additionally, if, for example, no system information is received, the device may perform cell reselection.

[0066] The function of the timer for accessing the device is to verify how long the stored system information can be considered valid. When the system information becomes invalid, the device can check whether the system information is available or reselect to another cell. In response to the expiration of the timer, the device can, for example, attempt to obtain SIB1 or all related SIBs and / or SSBs, send a request to the network for the relevant system information block or the relevant synchronization information block. If no further information is obtained from the network, the device can regard the cell as prohibited and move to other cells. Other actions can be taken to address the lack of valid system information.

[0067] Additionally, the network may control whether the UE should store information for a cell when it reselects to a different cell. For example, the network may predict the longest duration without system information (SI) modification (or at least without SIB1 modification) and set the validity timer accordingly. In this case, the stored information may be valid for the validity timer after the UE performs cell reselection away and then returns to a given cell.

[0068] According to one example, if the UE returns to camp on a cell while the UE is still operating in the No SIB mode, the UE may perform an On-Demand SIB procedure to check from the network whether any relevant SIBs are modified.

[0069] Figure 8 An example of a validity timer operation on the network side is shown. At 600, the network may send system information to a device in a cell for storage in a memory of the device. Then, as described above, when the system information provided by the network is not available in the cell, the device may use the stored information to access the cell. At 602, the network indicates to the device that the cell is operating in an operating mode in which system information is not sent in the cell. The network also indicates at 604 a validity timer for the system information stored in the memory in a message that is the same as or different from the message sent at 602. The indication may include necessary configuration information for the timer. Then, at 606, the network allows the device to access the cell based on the stored system information until the validity timer expires.

[0070] The validity timer may be valid even after the UE reselects to another cell and then moves back to the cell where the validity timer was started. The UE does not have to reacquire the SIBs, as they may not even be there, but may use the stored information. The UE knows how long the stored SIB information is valid and may rely on the stored information when reselecting back to the original SIB-free cell. For example, the information / indication provided in the RRC release message enables the UE to camp on a cell without SIBs, and as long as the timer is running, the UE does not consider the cell to be barred when it does not detect SIBs in the cell. If the timer has expired when the UE reenters the SIB-free cell, it is no longer possible to use the stored information and the UE considers the cell to be barred.

[0071] This operation is illustrated by the following pseudo-code example for the validity timer functionality, where upon receiving the MIB, the UE shall:

[0072] 1>Store the acquired MIB;

[0073] 1> If the UE is in RRC_IDLE or RRC_INACTIVE while timer T311 is running, or if the UE is in RRC_CONNECTED:

[0074] 2> If cellBarred in the obtained MIB is set to "barred":

[0075] 3> If the bit verification criteria are met for achieving SIB-free operation, 4> the cell is considered to be barred in "power saving mode" (ie,

[0076] No SIB1 transmission).

[0077] 4> The UE does not exclude the barred cell from candidates for cell selection / reselection until the configured validity timer value.

[0078] 4>UE can use the stored information to access "no SIB mode"

[0079] Community.

[0080] 3> Otherwise

[0081] 4> The cell is considered prohibited;

[0082] 4> Perform cell reselection to other cells on the same frequency as the prohibited cell;

[0083] 2> Otherwise:

[0084] 3>systemFrameNumber received by the application,

[0085] pdcch-ConfigSIB1, sub-CarrierSpacingCommon,

[0086] ssbSubcarrierOffset and dmrs-TypeA-Position.

[0087] The (legacy) cell barring bit of the broadcast SI information may be set to "true" to avoid legacy UEs camping on the cell when the cell is operating in SIB-free mode. According to one possibility, the UE may consider the cell as barred when the UE is unable to acquire the relevant SIB1. A UE supporting SIB-free operation having valid information for the cell stored in its memory may be configured not to consider the cell as barred and may therefore be able to perform all legacy idle / inactive mode operations in the cell (e.g., monitoring paging, accessing the network via RACH, evaluating cell reselection) using the stored configuration. A UE supporting SIB-free operation but not having valid information stored for the cell may consider the cell as barred and may cell (re)select / switch to the anchor cell.

[0088] Alternatively, the necessary information may be provided via a radio resource control (RRC) release message. For example, if the cell is the last cell used by the UE, the RRC release message may provide the necessary system information. The last used cell is the cell in which the UE receives the RRC release message. The last used cell providing the information may operate in normal mode / SIB mode, in which case the UE stores the information and therefore does not need to read the SIBs after moving to RRC idle / inactive. The last used cell may also already be in SIB-free mode. When the UE moves to idle or inactive mode with an RRC release message, the network may indicate the necessary information and SIB-free operating mode. The UE stores the information and thereafter, the UE does not need to attempt to obtain the SIBs from the cell, being aware that no SIBs, SSBs or SIB1s are currently being broadcast.

[0089] The relevant SIB information may be stored in an appropriate memory at the UE. The information required for SIB-free operation to be stored by the network to implement SIB-free mode operation may be defined in the relevant standard specifications. The stored information may include information such as paging configuration, RACH configuration, cell reselection configuration, small data transmission (SDT) configuration, unified access control (UAC) configuration, etc. Alternatively or additionally, the configuration may be indicated when an "RRC Release" message is sent before the UE switches to RRC inactive / idle mode, where the current serving cell may be operating in normal SIB mode or already in SIB-free mode.

[0090] Fig. 9 A specific example of switching from normal SIB mode operation to SIB-free mode is shown. An indication of a network operating in SIB-free mode may be provided by the network as a modified MIB to indicate to the UE whether the cell is operating in SIB-free mode or is about to operate in SIB-free mode. The application of a spare bit in a MIB field or a bit value confirmation in conjunction with other fields in the MIB may be used for indication. For example, if the cellBarred field in the acquired MIB is set to barred, the UE may consider the cell to be in SIB-free operation mode based on a combination of ssb-SubcarrierOffset (4 bits) = 0000 and pdcch-ConfigSIB1 (8 bits) = 00000000 or 111111111. According to another example, the UE may check whether a combination is received in which ssb-SubcarrierOffset indicates no SIB1 and pdcch-ConfigSIB1 = 00000000.

[0091] After transmitting the indication of the no SIB mode of operation, the network may switch to the no SIB mode of operation, where it does not transmit any SIB.

[0092] Fig.10 Another example of handover is shown. In this example, the configuration is done when the RRC release message is sent when the cell is the last cell used by the UE. This can be done even if the cell is already in SIB-free mode.

[0093] Fig.11 A specific example of the behavior of a UE in RRC Inactive / Idle state after receiving a modified MIB from the NW is shown. A UE configured according to 3GPP Release 18 and supporting SIB-free operation can determine that the cell is not barred and operate in SIB-free mode. The UE uses the stored SI information for further operations.

[0094] Fig.12 A situation is shown where a UE that does not support the no SIB mode may determine a cell operating in the no SIB mode as "barred". The ssb-SubcarrierOffset field of the synchronization signal block (SSB) is used to indicate that there is no SIB1, and then the legacy UE may consider the cell as barred and cannot camp on the cell. In response to this determination, the legacy UE may use legacy procedures such as cell reselection / handover (HO).

[0095] In the case of a Release 18 UE that supports no SIB but has no stored SI information, the UE may perform a cell reselection or handover (HO) to a (anchor) coverage cell. Alternatively, the UE may request or indicate a need for information from the anchor cell. The request may include an on-demand SIB1 request from another cell for a given cell ID. In one example, such an on-demand SIB1 request from another cell may be performed before the cell reselects to a cell operating in no SIB mode.

[0096] SIB-free mode operation can be applied to multi-carrier applications to reduce / adapt common channels / signals for at least some component carriers (CCs). In the case of inter-band carrier aggregation (CA), SSB-free secondary cell operation can be provided for some CCs. In the case of intra-band and inter-band CA, SIB-free operation can be implemented for some CCs.

[0097] The above principles can advantageously achieve power saving gains by, for example, relaxing / reducing SIB transmission in a low-load / empty system.

[0098] It should be noted that, while exemplary embodiments are described above, several variations and modifications may be made to the disclosed solution without departing from the scope of the present invention. Different features from different embodiments may be combined and the order of steps changed.

[0099] Therefore, the embodiments may vary within the scope of the appended claims. In general, some embodiments may be implemented in hardware or dedicated 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, but the embodiments are not limited thereto. Although various embodiments may be shown and described as block diagrams, flow charts, or using some other graphical representation, it is well understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices or logic, or some combination thereof.

[0100] These embodiments may be implemented by computer software stored in a memory and executable by at least one data processor of the entity involved, or executable by hardware, or executable by a combination of software and hardware. In addition, it should be noted at this point that any of the above processes may represent process steps, or interconnected logic circuits, blocks and functions, or a combination of process steps and logic circuits, blocks and functions. The software may be stored on a physical medium, such as a memory chip, or a memory block implemented within a processor, a magnetic medium (such as a hard disk or floppy disk), and an optical medium (such as, for example, a DVD and its data variants, a CD).

[0101] The memory may be of any type suitable for 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. As non-limiting examples, the data processor may be of any type suitable for the local technical environment and may include one or more general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), gate-level circuits, and processors based on multi-core processor architectures.

[0102] Alternatively or additionally, some embodiments may be implemented using circuitry. The circuitry may be configured to perform one or more of the aforementioned functions and / or method processes. The circuitry may be provided in a network entity and / or a communication device and / or a server and / or a device.

[0103] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0104] (a) hardware circuit implementation only (such as implementation in analog and / or digital circuitry only);

[0105] (b) a combination of hardware circuitry and software, such as: (i) a combination of analog and / or digital hardware circuitry and software / firmware, and (ii) any portion of hardware processor(s) working together with software (including digital signal processor(s), software and memory(s) to enable a communications device and / or equipment and / or server and / or network entity to perform the various functions described above; and

[0106] (c) Hardware circuit(s) and / or processor(s) (such as microprocessor(s) or portion(s) of microprocessor(s)) that require software (e.g., firmware) to operate, but where software is not required for operation, the software may not be present.

[0107] This definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or its) accompanying software and / or firmware. The term circuitry also covers, for example, an integrated device.

[0108] It should be noted that although embodiments have been described with respect to certain architectures, similar principles may be applied to other systems. Therefore, although certain embodiments are described by way of example with reference to certain exemplary architectures for wireless networks, technical standards, and protocols, the features described herein may be applied to any other suitable form of system, architecture, and device other than those shown and described in detail in the above examples. It should also be noted that different combinations of different embodiments are possible. It should also be noted here that although exemplary embodiments are described above, several variations and modifications may be made to the disclosed solution without departing from the spirit and scope of the present invention.

Claims

1. An apparatus for a communication device, comprising at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least: receiving a dedicated control message for releasing the communication device from a cell, the message comprising system information for storage in a memory of the communication device for use when accessing the cell when network-provided system information is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, storing the system information received in the dedicated control message in the memory, and An operation for accessing the cell is performed based on the stored system information.

2. A network device, comprising at least one processor and at least one memory, wherein the at least one memory comprises computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to at least: sending, to a communication device in a cell, system information for storage in the communication device in a dedicated control message for releasing the communication device from the cell for use when accessing the cell when system information provided by a network is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, and The communication device is allowed to access the cell based on the stored system information.

3. The apparatus according to claim 1 or 2, wherein the system information is included in a radio resource control (RRC) release message.

4. An apparatus according to any preceding claim, wherein the system information is included in a message received by the communications device, the message being used to release the communications device from a last cell used by the communications device.

5. An apparatus according to any preceding claim, wherein the communication device is configured to obtain the stored system information when in an idle state or an inactive state.

6. An apparatus according to any preceding claim, wherein the system information received in the dedicated control message comprises: The cell broadcasts system information in the cell when the cell is in an operation mode in which system information is sent in the cell.

7. The apparatus according to any preceding claim, wherein the system information comprises information of at least one of the following: paging configuration, random access channel configuration, cell reselection configuration, small data transmission configuration, and / or unified access control configuration.

8. An apparatus according to any preceding claim, wherein the system information included in the dedicated control message comprises: The information content of a system information block (SIB), a master information block (MIB), and / or a synchronization signal block (SSB).

9. The apparatus of claim 9, wherein the system information comprises information content of a system information block 1 (SIB1).

10. A method in a communication device, comprising: receiving a dedicated control message for releasing the communication device from a cell, the message comprising system information for storage in a memory of the communication device for use when accessing the cell when network-provided system information is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, storing the system information received in the dedicated control message in the memory, and An operation for accessing the cell is performed based on the stored system information.

11. A method for a network device, comprising: sending, to a communication device in a cell, system information for storage in the communication device in a dedicated control message for releasing the communication device from the cell for use when accessing the cell when system information provided by a network is not available in the cell, the dedicated control message indicating that system information is not to be sent in the cell, and The communication device is allowed to access the cell based on the stored system information.

12. The method according to claim 10 or 11, comprising: The system information is sent and / or received in a Radio Resource Control (RRC) release message.

13. The method according to any one of claims 10 to 12, comprising: The system information is sent and / or received in a message releasing the communication device from a last cell used by the communication device.

14. The method according to any one of claims 10 to 13, comprising: The communication device obtains the stored system information when in an idle state or an inactive state.

15. The method according to any one of claims 10 to 14, wherein the system information comprises: The cell broadcasts system information in the cell when the cell is in an operation mode in which system information is sent in the cell.

16. The method according to any one of claims 10 to 15, wherein the system information comprises at least one of the following information: paging configuration, random access channel configuration, cell reselection configuration, small data transmission configuration, and / or unified access control configuration.

17. The method according to any one of claims 10 to 16, wherein the system information included in the dedicated control message comprises: The information content of a system information block (SIB), a master information block (MIB), and / or a synchronization signal block (SSB).

18. The method of claim 17, wherein the system information comprises information content of a system information block 1 (SIB1).

19. A computer readable medium comprising a program code for causing a processor to execute instructions for the method according to any one of claims 10 to 18.

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