Providing system information

Abstract

An apparatus and method for enabling a device in a cell of a network to access the cell based on system information received from the network are provided. The system information is stored in the at least one memory for performing an operation for accessing the cell when the system information is not transmitted in the cell. The apparatus receives an indication that system information enabling access to the cell is not transmitted in the cell, and then performs an operation for accessing the cell based on the system information stored in the at least one memory.

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 communication devices (such as users or other terminal devices) and network entities (such as base stations / access points and / or other network nodes) in a communication system. An access network generally provides access to a communication system for a device. The access network is equipped with appropriate signal receiving and transmitting means for enabling communication and enabling 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 may be accessed by means of an appropriate wireless communication device, generally referred to as a user equipment (UE). The user's communication device may receive signaling by a node (e.g., a base station) at the radio access network and send and / or receive communications accordingly. For example, communications may include communications such as voice, video, electronic mail (email), text messaging, multimedia and / or content data. 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 / broadcasted to wireless devices. Broadcast refers to the ability to send 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 device can then use the broadcast system information to access the communication system.

[0005] Communication systems and associated equipment typically operate according to a given standard or specification that specifies what the various entities associated with the system are allowed to do and how it should be achieved. Communication protocols and / or parameters for accessing the system and communicating 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 is 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 at both the network and the device and may account for a significant portion of total energy consumption. Summary of the invention

[0007] According to one aspect, an apparatus is provided, the apparatus comprising at least one processor and 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 system information enabling access to a cell from a network, store the system information in the at least one memory for performing operations for accessing the cell when the system information is not transmitted in the cell, receive an indication that the system information enabling access to the cell is not transmitted in the cell, and perform operations for accessing the cell based on the system information stored in the at least one memory.

[0008] According to another aspect, an apparatus is provided, the apparatus comprising at least one processor and at least one memory including 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: send system information enabling a device to access a cell for storage in the memory of the device, indicate to the device that the cell operates in an operation mode in which the system information is not transmitted in the cell, and allow the device to access the cell based on the system information stored in the memory of the device.

[0009] According to a more specific aspect, the apparatus is configured to transition between an operation in which system information is broadcast in a cell and an operation in which system information is not broadcast in the cell.

[0010] According to one aspect, an indication is provided in a master information block (MIB) that system information block (SIB) information that enables access to a cell is not broadcast in the cell.

[0011] An indication is provided in a Radio Resource Control (RRC) release message that system information enabling access to a cell is not broadcast in the cell.

[0012] The device may be configured to obtain system information from the network in response to one of: notification by the network, cell reselection, handover, and expiration of a timer.

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

[0014] The apparatus in the network may be configured to send and the apparatus in the device may be configured to receive system information included in a system information block (SIB), a master information block (MIB), a synchronization signal block (SSB), and / or a radio resource control (RRC) message. According to a more specific aspect, the system information is included in a system information block 1 (SIB1). The system information may also be included in a radio resource control (RRC) release message sent in the last cell used by the device.

[0015] The apparatus may be configured to set a timer for the validity of the stored system information. The device may be configured to send a request for system information for a cell upon expiration of the timer. The device may also additionally or alternatively perform cell reselection.

[0016] The apparatus in the network may be configured to, in response to determining that transmission of system information in the cell is unnecessary, signal an indication that system information is not to be transmitted in the cell and / or refrain from broadcasting the system information in the cell.

[0017] Devices in the cell may be configured to, in response to receiving an indication that system information is not provided for the cell, use the stored system information to access the cell, rather than treating the cell as barred.

[0018] 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.

[0019] According to another aspect, a method for a device to access a network is provided, the method comprising receiving, at the device, system information enabling access to a cell from the network, storing the system information in a memory of the device for performing an operation for accessing the cell when the network does not send the system information, receiving an indication that the system information enabling access to the cell is not sent in the cell, and performing, at the device, an operation for accessing the cell based on the system information stored in the memory.

[0020] According to another aspect, a method for providing information for accessing the network in a network is provided, the method comprising sending system information that enables a device to access a cell to be stored in a memory of the device, indicating to the device that the cell operates in an operation mode in which the system information that enables access to the cell is not sent in the cell, and allowing the device to access the cell based on the system information stored in the memory of the device.

[0021] According to a more detailed aspect, the method may include transitioning between operation in which system information is broadcast in a cell and operation in which system information is not broadcast in a cell.

[0022] An indication that system information block (SIB) information enabling access to a cell is not broadcast in the cell may be sent from the network to the device in a master information block (MIB) and / or a radio resource control (RRC) release message.

[0023] The method may include the device acquiring system information from the network in response to one of a notification by the network, a cell reselection, a handover, and an expiration of a timer.

[0024] The method may include communication of system information including information of at least one of paging configuration, random access channel configuration, cell reselection configuration, small data transmission configuration and / or unified access control configuration.

[0025] The method may include transmission or reception of system information in a system information block (SIB), a synchronization signal block (SSB), a master information block (MIB) and / or a radio resource control (RRC) message.

[0026] According to a more specific aspect, the system information may be included in a system information block 1 (SIB1) or a radio resource control (RRC) release message.

[0027] The method may include setting a timer for validity of the stored system information. The device may send a request for system information of a cell and / or perform cell reselection upon expiration of the timer.

[0028] The device may, in response to receiving an indication that the network does not provide system information for the cell, use the stored system information to access the cell rather than treating the cell as barred.

[0029] The network entity may determine that transmission of system information in the cell is unnecessary and, in response thereto, signal an indication that system information is not to be transmitted in the cell and / or refrain from broadcasting the system information in the cell.

[0030] According to one aspect, a method and an apparatus for implementing the method are provided, the apparatus comprising at least one processor and 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: store system information in the at least one memory for a communication device to access a cell when system information provided by a network is not available in the cell, determine that the system information provided by the network is not available in the cell, start a validity timer for the system information stored in the at least one memory, perform an operation for accessing the cell based on the stored system information until the validity timer expires, and after the validity timer expires, perform at least one of the following: request system information for the cell from the network or initiate reselection to another cell.

[0031] According to one aspect, a method and an apparatus for implementing the method are provided, the apparatus comprising at least one processor and 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: send system information to a communication device in a cell to be stored in a memory of the communication device for accessing the cell when system information provided by a network is not available in the cell, indicate to the communication device that the cell operates in an operation mode in which the system information is not available in the cell, indicate a validity timer for the system information stored in the memory, and allow the communication device to access the cell based on the stored system information until the validity timer expires.

[0032] After reselection to another cell, the communications device may be enabled to perform reselection back to the cell before the timer expires.

[0033] According to one aspect, a method and an apparatus for implementing the method are provided, the apparatus for a communication device comprising at least one processor and 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 accessing the cell when system information provided by a network is not available in the cell, the dedicated control message indicating that the system information is not 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.

[0034] According to another aspect, a method and an apparatus for implementing the method are provided, the apparatus for a network apparatus comprising at least one processor and 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 apparatus to at least: send system information to a communication device in a cell in a dedicated control message for releasing the communication device from the cell for storage in the communication device for accessing the cell when the system information provided by the network is not available in the cell, the dedicated control message indicating that the system information is not sent in the cell, and allowing the communication device to access the cell based on the stored system information.

[0035] The system information may be included in a Radio Resource Control (RRC) release message.The system information may be included in a message received by a communications device for releasing the communications device from a last cell used by the communications device.

[0036] A component for implementing the operations and functions disclosed herein may also be provided. The component may include appropriately configured hardware and software.

[0037] A computer software product embodying 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

[0038] 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:

[0039] Figure 1 illustrates an example of a communication system in which the present invention may be practiced;

[0040] Figure 2 A data processing apparatus is shown; and

[0041] Figures 3 to 12 is a flow chart according to certain illustrative examples. DETAILED DESCRIPTION

[0042] The following description provides an exemplary description of some possibilities for practicing the present invention. Although the specification may refer to "an", "one" or "some" examples or embodiments at several locations in the text, this does not necessarily mean that the same example or embodiment is mentioned each time, nor does it necessarily mean that a particular feature only applies to a single example or embodiment. Individual features of different examples and embodiments may also be combined to provide other embodiments.

[0043] A wireless communication system can provide mobile communications to devices connected therein. Typically, access points such as base stations are provided to enable communication for devices connected to the access points. 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 suitable for the system 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), 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. These principles can also be applied to any next generation access system.

[0044] 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 in this specification. An access point may include any node that can send / receive radio signals (e.g., a 3GPP 5G 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 a certain number of base stations.

[0045] 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 to the cell provided by the access point 11-13 and camp on it. Camping on a cell refers to a state in which the device stays on the cell and is ready to initiate potential dedicated services or receive ongoing broadcast services.

[0046] Figure 1 A control function entity 10 is also shown. 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. The control function entity 10 may also be configured to control the delivery of system information to devices 15 in the cell, as described below. Non-limiting examples of possible network control functions include a medium access control (MAC) entity and / or a radio resource control (RRC) entity.

[0047] It should be noted that the broader communication system is shown only as cloud 1 and may include a certain number of 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 (AFs), and one or more data networks (DNs). The 5G-RAN may include one or more gNodeBs (gNBs) or one or more gNodeB distributed unit functions connected to one or more gNodeB centralized unit functions. The 5GC may also include entities such as a network slice selection function (NSSF); a network open 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); and various session management functions (SMFs).

[0048] 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 so-called 'smartphone'), a computer equipped with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA) or tablet equipped with wireless communication capabilities, 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 send signals via an appropriate device for sending radio signals. Communication can be carried out via multiple paths. The communication device can have the capability of carrier aggregation (CA) and wireless communication via component carriers (CC). In order to achieve multiple input multiple output (MIMO) type, the communication device can be equipped with multiple antenna elements.

[0049] Devices such as base stations, terminal devices and network functions are equipped with data processing means comprising at least one processor and at least one memory. Figure 1 An 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.

[0050] The data processing apparatus typically comprises a processor(s) 22 , 52 , 53 and one or more memories 21 and 51 . Figure 2 Connections between elements of the device are also shown. An interface 54 for connecting a data processing device to other components of the device is also shown. 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-assisted execution of the tasks it is designed to perform, including implementing the features described herein related to processing system information and processing access-related tasks based on system information. At least one processor may be coupled to at least one memory. 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.

[0051] 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 sent from a single source to multiple destinations / devices in a region simultaneously. Broadcast refers to the ability to send information to all users in a region, which is a collection of one or more network access nodes (e.g., base stations and / or cells capable of delivering the same information).

[0052] exist Figure 1 , signaling of system information from the access node 11 to one of the devices 15 is illustrated by arrow 16, and possible subsequent communication by the UE is illustrated by arrow 17. A base station 11 of the access network may broadcast system information (SI) to the UEs 15 in a cell in elements such as synchronization signal blocks / system information blocks (SSB / SIB).

[0053] Broadcasts may be frequent and result in heavy use of resources and power consumption. One 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 stay on the cell. The SIB may include SIB1, and any one of SIB2 to SIB5 as required. SIB1 is a cell-specific information element valid only for the serving cell, and carries key information required for the UE to access the cell. SIB1 contains information relevant to evaluating whether a UE is allowed to access a 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 barring information applied to unified access control. SIB2 to SIB5 elements may contain other information, such as cell reselection information.

[0054] System information is needed because it provides the UE with the parameters required to access the network and detect paging messages. New Radio (NR) supports on-demand system information based on the Random Access Channel (RACH), but SIB1 messages are not included in RACH because broadcast SIB1 information provides the RACH configuration required to access a cell.

[0055] Sometimes it may not be necessary to broadcast system information frequently, which may lead to inefficient resource usage. For example, in certain areas and / or certain time periods and / or applications, there may be no new UEs or SIB updates most of the time. Examples of this are nighttime, weekends and / or public holidays in an area with offices, schools and other similar places.

[0056] Opportunities and periods when SIBs do not need to be sent frequently can be identified and used to reduce power consumption by avoiding sending SIBs. This mode of operation is referred to as SIB-less mode operation hereinafter. SIB-less mode can be provided in both time domain and frequency domain techniques.

[0057] According to a possible operation mode, other SSBs are transmitted, but the operation is SIB1-free, i.e., SIB1 is not 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 energy saving.

[0058] One problem in SIB-free operation is how to provide the necessary paging / RACH configuration for the UE. If the cell operates in SIB-free mode, the legacy UE is prevented from camping on the cell. The legacy UE here refers to a device that cannot be or cannot be 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. The legacy UE can be provided with an indication that they are prohibited from entering the cell. This can be provided, for example, by a cellbarred indication in the MIB. Later UEs (i.e., SIB-free UEs that comply with, for example, 3GPP Release 18 and higher) will also receive the indication. The SIB-free UE is made aware that the network is operating in SIB-free mode, and the SIB-free UE can consider the cellbarred indication to be redundant and remain in the SIB-free cell.

[0059] 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 message 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 remain in the cell and use the stored information after the NW indicates no SIB mode of operation. Without knowledge of the stored system information, a non-Release 18 capable UE may perform cell reselection / HO to other cells in a manner substantially similar to a legacy UE.

[0060] A mechanism can be provided for transferring from a traditional SIB mode to a SIB-free mode between different SIB operation modes 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. The terms traditional operation mode, normal mode, and with-SIB operation mode in this specification refer to current SIB operations that require SIBs from the network to access the network. This operation mode is referred to as the SIB operation mode hereinafter. An operation mode in which frequent SIB signaling is not required and the network suspends sending system information (more specifically SIBs) is referred to as a SIB-free operation mode.

[0061] 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 sends system information that enables at least one device to access a cell to be stored in a memory of at least one device. The transmission may include a broadcast of the system information in the cell. The system information may also be sent 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. Therefore, at least one device in the cell cannot receive any system information required for access. At 104, based on the system information stored in the at least one device, the at least one device is allowed to access the cell.

[0062] Figure 4 An example of operations at a device for accessing a network is shown. The device receives system information that enables access to a cell from the network at 200. The system information is stored in a memory of the device at 202 for the device to perform operations for accessing a cell when the network does not provide the system information. The device in the cell can then perform the necessary operations for access based on the system information stored in the memory at 204.

[0063] Figure 5 and Figure 6 Examples of methods at a network and a device are respectively shown when the network transitions between an operation mode in which the network provides system information and an operation mode in which the network does not provide system information.

[0064] exist Figure 5 In the embodiment of the present invention, the network sends system information enabling at least one device to access a cell to be stored in a memory of at least one device at 300. A decision is made to switch from a first operation mode (in the first operation mode, the system information is sent in the cell) to a second operation mode (in the second operation mode, the 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, based on the system information stored in the memory of the at least one device, the at least one device is allowed to access the cell.

[0065] Figure 6 An example of operation at a device when the network transitions its mode to operation in which no system information is sent in a cell is shown. In the method, the device stores system information enabling access to a cell in at least one memory at 400 for performing operations for accessing a cell when the system information is not provided in the cell. For example, the device may receive the information during normal operation of the cell and / or in an RRC message (such as an RRC release message).

[0066] Then, at 402, the device receives an indication that system information enabling access to a cell is not provided in the cell. Then, 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 the network to a second mode of operation in which system information is provided in the cell and in which system information is not provided in the cell at 404. Then, at 406, operations for accessing the cell may be performed based on the system information stored in the at least one memory.

[0067] A more detailed example of enabling operation without frequent system information messages is described below, taking the context of SIB-free operation as an example. SIB-free operation can be achieved by configuring the UE to obtain the necessary information required for idle / inactive mode operation in a given cell from a given cell and storing the information in the UE's memory. The information may include information such as paging / RACH configuration and / or cell reselection and handover configuration.

[0068] According to one possibility, the system information mode in the cell can 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 can use the system information stored in its memory. The UE can assume that there will be no additional SIB updates during the SIB-free mode.

[0069] After the network switches back to SIB mode from no SIB mode, or if SIB update is required during no SIB mode, the NW may update the SIB mode indication in the additional MIB. Reception of the additional 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.

[0070] The network may decide to operate in an operating mode where no system information is sent 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 the switch may be network implementation specific. Other non-limiting examples include date and / or time of day, detection of no new UE entering the cell within a predefined period, and the like.

[0071] The decision regarding the use of an operating mode in which no system information is sent 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 enter and exit SIB-free operation. According to a specific example, the RRC entity may make this decision based on input from the MAC entity based on the traffic load in the cell.

[0072] According to a specific example, a SIB1-free mode operation is provided, in which the network avoids the transmission of SIB1 information of a cell for a certain 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.

[0073] A validity timer may be set for the stored system information. Before the validity timer expires, the stored system information may be assumed to be valid for an operation mode in which the relevant system information is not sent. Figure 2 In the data processing device 50, 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 by MIB or RRC signaling. The validity timer configuration information can be provided in the same message as the following indication: switching to an operation without system information being sent, and the validity timer configuration information can also be provided separately.

[0074] An example of the operation of the timer at the access device is as follows Figure 7 As shown. The device stores system information in at least one memory at 500 for accessing a cell when the network operates in a mode in which the system information is not available in the cell. The device starts a timer for the validity of the system information stored in the at least one memory at 502. At 504, before the timer expires, an operation for accessing the cell is performed based on the stored system information. After the timer expires, the device may send a request for system information of the cell at 506. Alternatively or additionally, for example, if no system information is received, the device may perform cell reselection.

[0075] One 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. For example, in response to the expiration of the timer, the device can attempt to obtain SIB1 or all relevant SIBs and / or SSBs, sending a request to the network for relevant system information blocks or relevant synchronization information blocks. If no additional information is obtained from the network, the device can consider the cell to be barred and move to other cells. Other actions can be taken to resolve the problem of lack of valid system information.

[0076] In addition, the network can control whether the UE should store information for a cell after a cell reselection to a different cell. For example, the network can 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 within the validity timer after the UE performs cell reselection away and back to a given cell.

[0077] According to one example, if the UE returns to the cell while still operating in no SIB mode, the UE may perform an on-demand SIB procedure to check from the network whether any relevant SIBs are modified.

[0078] Figure 8 An example of the validity timer operation on the network side is shown. The network can send system information to a device in a cell at 600 to be stored 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 can use the stored information to access the cell. At 602, the network indicates to the device that the cell operates in an operating mode in which the system information is not sent in the cell. The network also indicates the validity timer for the system information stored in the memory at 604 with 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.

[0079] The validity timer remains 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 necessarily need to reacquire the SIBs, as they may not exist at all, but can use the stored information. The UE knows how long the stored SIB information is valid and can 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 when the UE does not detect SIBs in the cell, the UE does not consider the cell to be barred as long as the timer is running. If the timer has expired when the UE reenters the SIB-free cell, the use of the stored information is no longer possible and the UE considers the cell to be barred.

[0080] This operation is illustrated by the following pseudo-code example of a validity timer function, where upon receiving the MIB, the UE shall:

[0081] 1>Store the acquired MIB;

[0082] 1> If the UE is in RRC_IDLE or RRC_INACTIVE, or if the UE is in RRC_CONNECTED while timer T311 is running:

[0083] 2> If cellBarred in the obtained MIB is set to "prohibited":

[0084] 3> If the bit verification criteria for enabling SIB-free operation are met, then

[0085] 4> The cell is considered to be disabled in “power saving mode” (ie, no SIB1 transmission).

[0086] 4> The UE shall not exclude the prohibited cell from the candidates for cell selection / reselection and shall continue to use the configured validity timer value.

[0087] 4> The UE can apply the stored information to access the "no SIB mode" cell.

[0088] 3> Otherwise

[0089] 4>Thinking that the community has been banned;

[0090] 4> Perform cell reselection on other cells with the same frequency as the prohibited cell;

[0092] 2> Otherwise:

[0093] 3> Apply the received systemFrameNumber, pdcch-ConfigSIB1, sub-CarrierSpacingCommon, ssbSubcarrierOffset and dmrs-TypeA-Position.

[0094] The (legacy) cell barring bit of broadcast SI information may be set to "true" to avoid legacy UEs camping on a cell when the cell operates in SIB-free mode. According to one possibility, the UE may consider the cell to be barred when the UE is unable to acquire the relevant SIB1. A UE supporting SIB-free operation with valid information of a cell stored in its memory may be configured not to consider the cell as barred and may therefore be able to perform all traditional 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 storing valid information for the cell may consider the cell to be barred and may (re)select / switch to an anchor cell.

[0095] 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 that supplies this information may operate in normal mode / SIB mode, in which case the UE stores the information and therefore does not need to read the SIB after moving to the RRC idle / inactive state. The last used cell may also already be in SIB-free mode. When the UE moves to idle or inactive mode via an RRC release message, the network may indicate the necessary information and SIB-free operating mode. The UE stores this information and thereafter does not need to attempt to obtain the SIB from the cell, knowing that the SIB, SSB, or SIB1 is not currently being broadcast.

[0096] The relevant SIB information may be stored in an appropriate memory at the UE. The necessary information for the SIB-free operation to be stored for the network to enable the 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 operate in normal SIB mode or is already in SIB-free mode.

[0097] Fig. 9A specific example of switching from normal SIB mode operation to SIB-free mode is shown. The network may provide an indication that the network is operating in SIB-free mode as a modified MIB to indicate to the UE whether the cell is or will be operating in SIB-free mode. The joint application of spare bit or bit value verification in the MIB field and other fields in the MIB may be used for the indication. For example, if the cellBarred field in the acquired MIB is set to prohibited, the UE may consider the cell to be in SIB-free operation mode based on a combination of ssb-SubcarrierOffset (4-bit) = 0000 and pdcch-ConfigSIB1 (8-bit) = 00000000 or 111111111. According to another example, the UE may check whether a combination of ssb-SubcarrierOffset indicating the absence of SIB1 and pdcch-ConfigSIB1 = 00000000 is received.

[0098] After sending the indication of the no SIB operation mode, the network may switch to the no SIB operation mode, in which the network does not send any SIB.

[0099] Fig.10 Another example of handover is shown. In this example, the configuration is complete 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.

[0100] Fig.11 A specific example of the behavior of a UE in RRC inactive / idle state after receiving a modified MIB from a NW is shown in FIG. A UE configured according to 3GPP Release 18 and supporting SIB-free operation may determine that the cell is not barred and is operating in SIB-free mode. The UE uses the stored SI information for further operation.

[0101] Fig.12 A scenario is shown in which a UE that does not support the No SIB mode may determine that a cell operating in the No SIB mode is "barred". The ssb-SubcarrierOffset field of the synchronization signal block (SSB) is used to indicate that SIB1 is not present, and then the legacy UE may consider the cell to be barred and cannot camp on the cell. In response to such a determination, the legacy UE may use legacy procedures such as cell reselection / handover (HO).

[0102] In the case where a Release 18 UE supports No SIB but does not store SI information, the UE may perform a cell reselection or handover (HO) to an (anchor) coverage cell. Alternatively, the UE may request or indicate the need for information to the anchor cell. The request may include an on-demand SIB1 request for a given cell ID from another cell. In one example, such an on-demand SIB1 request from another cell may be performed prior to cell reselection to a cell operating in No SIB mode.

[0103] SIB-free mode operation can be applied to multi-carrier applications to reduce / adjust the common channels / signals of 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 enabled for some CCs.

[0104] The above principles can be advantageously used to achieve energy saving gains by relaxing / muting SIB transmissions, for example in low-load / empty systems.

[0105] 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.

[0106] 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 illustrated 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-purpose hardware or controllers or other computing devices, or some combination thereof.

[0107] Embodiments may be implemented by computer software stored in a memory and executable by at least one data processor of the entity involved, or by hardware, or by a combination of software and hardware. In addition, in this regard, it should be noted that any of the above processes may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. Software may be stored on physical media, such as memory chips or memory blocks implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and data variants thereof, CDs, etc.

[0108] 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. The data processor may be of any type suitable for the local technical environment and may include, by way of non-limiting example, 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.

[0109] Alternatively or additionally, some embodiments may be implemented using a circuit system. The circuit system may be configured to perform one or more of the previously described functions and / or method processes. The circuit system may be provided in a network entity and / or a communication device and / or a server and / or a device.

[0110] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0111] (a) Pure hardware circuit implementation (such as implementation in analog and / or digital circuit systems only);

[0112] (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) (including digital signal processor(s)), software and memory(s) with software, which work together to enable a communications device and / or equipment and / or server and / or network entity to perform the various functions described above; and

[0113] (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 the software may not be present, for operation.

[0114] 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 accompanying software and / or firmware. The term circuitry also covers, for example, an integrated device.

[0115] It should be noted that although embodiments have been described for certain architectures, similar principles may also be applied to other systems. Therefore, although certain embodiments are described above by way of example with reference to certain exemplary architectures of 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 herein that although exemplary embodiments are described above, several changes and modifications may be made to the disclosed solution without departing from the spirit and scope of the invention.

Claims

1. An apparatus comprising at least one processor and at least one memory including 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 apparatus to at least: receiving system information from the network that enables access to the cell, storing the system information in the at least one memory for performing operations for accessing the cell when the system information is not transmitted in the cell, receiving an indication that system information enabling access to the cell is not to be transmitted in the cell, and An operation for accessing the cell is performed based on the system information stored in the at least one memory.

2. An apparatus comprising at least one processor and at least one memory including 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 apparatus to at least: sending system information enabling a device to access a cell for storage in a memory of the device, indicating to the device that the cell operates in an operation mode in which system information is not transmitted in the cell, and The device is allowed to access the cell based on the system information stored in the memory of the device.

3. The apparatus according to claim 1 or 2, configured to transfer between an operation in which system information is broadcast in the cell and an operation in which system information is not broadcast in the cell.

4. An apparatus according to any preceding claim, wherein an indication that system information block (SIB) information enabling access to the cell is not broadcast in the cell is provided in a master information block (MIB).

5. An apparatus according to any preceding claim, wherein an indication that system information block (SIB) information enabling access to the cell is not broadcast in the cell is provided in a radio resource control (RRC) release message.

6. An apparatus according to any preceding claim, wherein the device is configured to obtain system information from the network in response to one of: a notification by the network, a cell reselection, a handover, and expiry of a timer.

7. The apparatus according to any one of the preceding claims, 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. The apparatus of any preceding claim, wherein the system information is included in a system information block (SIB), a master information block (MIB), a synchronization signal block (SSB), and / or a radio resource control (RRC) message.

9. The apparatus of claim 8, wherein the system information is included in a system information block 1 (SIB1).

10. The apparatus of claim 8, wherein the system information is included in a radio resource control (RRC) release message sent in a last cell used by the device.

11. The apparatus according to any of the preceding claims, configured to set a timer for validity of the system information stored in the at least one memory.

12. The apparatus according to claim 11, wherein the device is configured to: upon expiration of the timer, send a request for system information of the cell and / or perform cell reselection.

13. An apparatus according to claim 2 or any claim dependent on claim 2, configured to: in response to determining that the transmission of system information in the cell is unnecessary, signal an indication that system information will not be transmitted in the cell, and / or avoid broadcasting the system information in the cell.

14. An apparatus according to any preceding claim, wherein the device is configured to: in response to receiving the indication that the network does not provide system information for the cell, use the stored system information to access the cell instead of treating the cell as barred.

15. An apparatus according to any preceding claim, wherein the device is 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.

16. A method for accessing a network, comprising: receiving, at a device, system information enabling access to a cell from the network, storing the system information in a memory of the device for performing an operation for accessing the cell when the network does not send the system information, receiving an indication that system information enabling access to the cell is not to be transmitted in the cell, and Based on the system information stored in the memory, operations for accessing the cell are performed at the device.

17. A method for providing information for accessing a network, comprising: sending system information enabling a device to access a cell for storage in a memory of the device, indicating to the device that the cell operates in an operation mode in which system information enabling access to the cell is not transmitted in the cell, and The device is allowed to access the cell based on the system information stored in the memory of the device.

18. The method according to claim 16 or 17, comprising: A transition is made between an operation in which system information is broadcast in the cell and an operation in which system information is not broadcast in the cell.

19. The method of claim 18, wherein an indication that system information block (SIB) information enabling access to the cell is not broadcast in the cell is included in a master information block (MIB) and / or a radio resource control (RRC) release message.

20. A method according to any one of claims 16 to 19, comprising: The device acquires system information from the network in response to one of: notification by the network, cell reselection, handover, and expiration of a timer.

21. The method according to any one of claims 16 to 20, 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.

22. The method according to any one of claims 16 to 21, wherein the system information is included in a system information block (SIB), a synchronization signal block (SSB), a master information block (MIB), and / or a radio resource control (RRC) message.

23. The method of claim 22, wherein the system information is included in a system information block 1 (SIB1) or a radio resource control (RRC) release message.

24. A method according to any one of claims 16 to 23, comprising: A timer is set for the validity of the system information stored in the memory.

25. The method according to claim 24, comprising: When the timer expires, the device sends a request for system information of the cell and / or the device performs cell reselection.

26. A method according to any one of claims 16 to 25, comprising: The device, in response to receiving an indication that the network does not provide system information for the cell, uses the stored system information to access the cell instead of treating the cell as barred.

27. A method according to any one of claims 16 to 26, comprising: In response to the network entity determining that transmission of system information in the cell is unnecessary, signaling an indication that system information is not to be transmitted in the cell and / or refraining from broadcasting the system information in the cell.

28. A computer readable medium comprising a program code for causing a processor to execute instructions for the method according to any one of claims 16 to 27.

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