595 results about "Radio link failures" patented technology

A method and apparatus for using a CHO configuration for RLF recovery in a wireless communication system is provided. A wireless device may receive, from a network, a CHO configuration including (1) information on candidate cells including a NTN cell, and (2) information on a first time period associated with the NTN cell. The wireless device may stop the CHO evaluation for the NTN cell after the first time period. The wireless device may perform cell selection, upon detecting radio link failure during the second time period. The wireless device may perform a CHO to the NTN cell, based on that the NTN cell is selected by the cell selection.

According to certain embodiments, a method is performed by a network node comprising a CU. The method comprises receiving assistance information for mobility robustness optimization and forwarding the assistance information, configuration changes related to mobility robustness optimization, or both to a DU or to a second CU. According to certain embodiments, a method is performed by a network node comprising a DU. The method comprises receiving assistance information for mobility robustness optimization. The assistance information indicates that a failure may have originated in a cell of the DU. The method further comprises performing one or more parameter changes in one or more functions handled by the DU.

A method can include transmitting, by a wireless device to a base station, via a first cell of the wireless device, an uplink signal based on determining a radio link failure of a second cell, the second cell being configured for early timing advance (TA) acquisition. The transmitting the uplink signal can be at least one of: based on the second cell being configured for early timing advance acquisition of the wireless device; or after receiving, by the wireless device, an indication to at least one of acquire a TA value of the second cell; start to acquire the TA value of the second cell; or transmit, by the wireless device via the second cell, a reference signal.

Provided in the present disclosure are a method for radio link failure recovery and user equipment. In the method for radio link failure recovery, a user equipment (UE) detects that a handover failure occurs, and when the UE has a stored conditional handover (CHO) configuration, or when the UE has a stored conditional handover (CHO) configuration and CHO recovery is enabled, the UE reverts back to a configuration used in a source cell. The configuration used in the source cell includes one or more of a physical layer dedicated configuration, a medium access control (MAC) layer configuration, or a semi-persistent SPS configuration.

The present disclosure relates to handling a master cell group (MCG) failure in wireless communications. According to an embodiment of the present disclosure, a method performed by a wireless device in a wireless communication system comprises: receiving, from a source primary cell (PCell), a conditional mobility command including a mobility condition for a target PCell; starting a timer for a master cell group (MCG) failure recovery and transmitting MCG failure information related to the MCG failure recovery to a primary secondary cell (PSCell), based on detecting a radio link failure (RLF) on the source PCell; and based on that the mobility condition for the target PCell is satisfied while the timer is running: transmitting, to the PSCell, a new PCell indication informing a mobility from the source PCell to the target PCell; and performing a random access to the target PCell for the mobility.

A method and device are disclosed from the perspective of a User Equipment-to-User Equipment (UE-to-UE) Relay. In one embodiment, the method includes the UE-to-UE Relay establishing a first PC5 unicast link with a first UE and establishes a second PC5 unicast link with a second UE. The method further includes the UE-to-UE Relay initiating a Layer-2 link release procedure to release the second PC5 unicast link if a sidelink radio link failure is detected on the first PC5 unicast link.

According to some embodiments, a method is performed by a wireless device capable of operating in a non-terrestrial network (NTN). The method comprises determining an amount of time until a service link or feeder link switch and, based on the determined amount of time, modifying a radio link failure parameter used to determine when to declare a radio link failure (RLF).

An apparatus in accordance with the present application may monitor a sidelink (SL) connection. The apparatus includes processing circuitry that receives signals in a protocol stack to perform SL-radio link monitoring (SL-RLM), and determines, according to the signals, whether a SL-radio link failure (RLF) has occurred. The signals may include hybrid automatic repeat request (HARQ) feedback. In a case that the signals include a HARQ-NACK, the processing circuitry determines that the SL-RLF has occurred. The processing circuitry further receives configuration information related to the SL-RLM for the signals, the configuration information including configurations for measurement quantities of the signals and a condition for declaring SL-RLF, configures, according to the configuration information, lower layers of the protocol stack for the SL-RLM for the signals, and performs SL-RLM measurements of the measurement quantities.

Methods performed by a network node in a radio communication network are provided herein. Operations according to such methods include detecting a radio link failure on a master cell group and indicating to a user equipment whether to use a master cell group fast recovery procedure to avoid a radio resource control re-establishment.

The present application relates to devices and components including apparatus, systems, and methods for performing measurements before a radio link failure. In an example, a condition is detected by a UE in advance of a time point in which a non-terrestrial network (NTN) node is to stop providing service to the UE. The condition can be a timing-based condition related to, for example, t-service, a location-based condition related to, for example, a reference location, a coverage hole, and / or a timer condition. The UE can perform, in advance of the time point, a radio resource management (RRM) measurement in an attempt to measure a neighbor cell based on the condition.

Certain aspects of the present disclosure provide techniques for RRC connection reestablishment by a remote UE. In some cases, a remote UE may be configured to detect, on at least one of a first link between a first relay UE and a first network entity or a second link between the remote UE and the first relay UE, a radio link failure (RLF) resulting in a loss of radio resource control (RRC) connection and attempt to reestablish RRC connection by performing at least one of relay selection or cell selection.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may detect radio link failure (RLF) or handover failure. The UE may perform, based at least in part on the RLF or the handover failure, one or more of layer 1 or layer 2 triggered mobility (LTM) or conditional handover based at least in part on a prioritization of LTM and conditional handover during failure recovery. Numerous other aspects are described.

A donor device, applicable to an F1-terminating donor-CU of a mobile IAB node, includes: a receiver configured to receive first indication information, the first indication information comprising identity information related to a third donor-CU which is an RRC-terminating donor-CU after migration or radio link failure recovery of the mobile IAB node; and a transmitter configured to transmit second indication information for indicating a context of a traffic to the third donor-CU.

Embodiments include methods for a user equipment (UE) to synchronize timing with a wireless network. Such methods include receiving, from a first node serving a first cell in the wireless network, a first message that includes an absolute reference time and a corresponding reference event within downlink, DL, transmissions by the first node; and determining whether the UE received, from the first node, a timing adjustment value from which the UE can estimate a propagation delay of the DL transmissions. Such methods include, based on determining that the UE did not receive the timing adjustment value, performing one of the following: transmitting, to the first node, an indication that the UE did not receive the timing adjustment value; or declaring radio link failure with respect to the first cell and establishing a connection with a second cell capable of providing the information included in the first message.

A wireless device receives, from a base station, configuration parameters indicating a plurality of bandwidth parts of a cell. Power measurements that indicate a listen before talk (LBT) failure on each of the plurality of bandwidth parts are performed. A radio link failure of the cell is declared in response to the power measurements indicating the LBT failure on each of the plurality of bandwidth parts.

The invention relates to a method in a user equipment, UE, for performing handover to a target cell in a wireless network, the method comprising performing (1340) a first random-access, RA, procedure in first RA resources of the target cell, in response to failure of the first RA procedure, refraining (1350) from declaring a radio link failure, RLF, for the target cell and performing a second RA procedure in second RA resources of the target cell that are different from the first RA resources; and declaring (1370) a RLF for the target cell based on failure of the first RA procedure and a failure of the second RA procedure, or an expiration of a timer before successful completion of the second RA procedure; the invention further relates to a UE implementing the method, to a corresponding method in a network node and a network node implementing the method.

Apparatuses, systems, and methods for a framework for user consent delivery and utilization in cellular communication systems. An access and mobility management function (AMF) of a network may obtain, from a user data management (UDM), user consent information via a user consent parameter included in a structured data type. The AMF may provide, to a base station of the network, the user consent information via a user consent information element. The user consent information element may be associated with at least one data type and the at least one data type may include radio link failure (RLF) information sharing consent and / or user location information sharing consent. The user consent information element may be included in any of an initial context setup request message, a user equipment (UE) context modification request message, and / or a handover request message.

A terminal apparatus for communicating with a base station apparatus is provided. The terminal apparatus includes a receiver configured to receive a Radio Resource Control (RRC) reconfiguration message including a parameter related to a first configuration from the base station apparatus, and a processing unit configured to perform configuration in accordance with the RRC reconfiguration message received. In a case that a first timer of an RRC protocol expires, a radio link failure of a source primary cell is not detected, and configuration related to Dual Active Protocol Stack (DAPS) handover is performed for the terminal apparatus, the processing unit reconfigures all of state variables configured for a Radio Link Control (RLC) entity of a Signaling Radio Bearer (SRB) in the source primary cell to respective initial values, resumes the SRB suspended in the source primary cell, and transmits an RRC message for notifying the base station apparatus that the DAPS handover has failed.

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a user equipment (UE) supporting a fast Master Cell Group (MCG) link recovery for Multi Radio-Dual Connectivity (MR-DC) is provided. The method comprising: initiating the fast MCG link recovery, based on occurrence of a radio link failure (RLF) in MCG; and in case that failure of the fast MCG link recovery is identified, transmitting a RLF report including cause information indicating at least one of expiry of a timer, secondary cell group (SCG) deactivation or SCG failure.

A user equipment with a communication session existing with terrestrial radio network node may receive from the terrestrial node a link recovery configuration comprising a context identifier indicative of context information corresponding to the communication session. Based on poor radio link conditions or radio link failure, the user equipment may determine to transmit to a non-terrestrial node, identified in the link recovery configuration, a session transfer request that includes the context identifier. The session transfer request may be transmitted according to a timing advance or according to a non-terrestrial resource, associated with a non-terrestrial node identifier corresponding to the non-terrestrial node in the link recovery configuration. The session transfer request may request transfer of the existing communication session from the terrestrial node to the non-terrestrial node. Based on the context identifier, the non-terrestrial node may retrieve, from the terrestrial node, session context information usable to facilitate the existing communication session.

An operating method of a user equipment (UE) in a wireless communication system according to an embodiment of the disclosure may include receiving configuration information from a source base station (BS), determining, based on the configuration information, whether Dual Active Protocol Stack (DAPS) handover is configured for at least one bearer, based on a result of the determining, maintaining a link to the source BS, performing the DAPS handover on a target BS, suspending a Signaling Radio Bearer (SRB) configured for the source BS, and establishing a SRB for the target BS, when it is determined that the DAPS handover fails, determining whether a radio link failure (RLF) occurs in the link to the source BS, and based on a result of the determining, when the RLF does not occur in the link to the source BS, resuming the SRB configured for the source BS and reporting the failure of the DAPS handover.

A method (400) for reporting radio link failure, RLF, information. The method includes a user equipment, UE, detecting (s402) an RLF with respect to a master cell group, MCG. The method also includes, in response to detecting the RLF with respect to the MCG, the UE storing (s404) RLF information. The method also includes the UE sending (s406) a first message comprising MCG failure information, e.g., the RLF information, and activating a timer. The method also includes the UE receiving (s408) a second message after sending the first message and activating the timer. The method also includes the UE, in response to receiving the second message, determining (s410) that a condition is satisfied, wherein determining that the condition is satisfied comprises at least determining that the timer is still running. The method also includes, as a result of determining that the condition is satisfied, the UE deleting (s412) the RLF information.

The present disclosure provides a radio link failure reporting method and user equipment. The radio link failure reporting method includes: detecting, by user equipment (UE), occurrence of a radio link failure (RLF); and storing, by the UE, radio link failure information in an RLF report, wherein if the UE has performed a handover procedure before the RLF, the radio link failure information includes: information for indicating the type of the handover procedure; a global cell identity and a tracking area code of a cell where the latest handover command was received; and an elapsed time starting from reception of the latest handover command.

The present disclosure relates to a 5G or 6G communication system supporting a higher data transmission rate. A method of a user equipment (UE) is provided. The method includes receiving first information related to reception of a reference signal (RS). The RS comprises a channel state information RS (CSI-RS) or a synchronization signal. The RS is associated with a beam failure (BF) detection, a radio link failure (RLF) detection, or a CSI report. The method also includes receiving second information related to a hypothetical adaptation of a transmission power of the RS, and receiving the RS based on the first information. The method further includes determining a report amount indicating a hypothetical channel condition based on the second information and the reception of the RS, and transmitting a channel carrying the report amount indicating the hypothetical channel condition.

The present disclosure relates to a 5th-Generation (5G) or 6th-Generation (6G) communication system for supporting higher data transmission rates. A method performed by a user equipment (UE) in a wireless communication system is provided. The method includes receiving a first system information block (SIB) associated with satellite assistance information from a base station, the first SIB including first information about a serving cell ephemeris table and second information about an effective duration of a serving cell astronomical table, and receiving a second system information block (SIB) associated with the neighbor satellite information from the base station based on a first timer whose duration is an effective duration of the serving cell ephemeris and a second timer for obtaining the first SIB prior to a radio link failure (RLF), the second SIB including third information about the neighbor cell ephemeris.

A reporting method is performed by a terminal device, and includes: reporting a radio link failure report (RLF-report) to a network-side device in response to triggering the RLF-report, wherein the RLF-report carries at least one of received signal strength indicator (RSSI) information or channel occupancy (CO) information.

Devices and methods where a repeater device determines that a failure event has occurred, and in response to this determining, stops performing a forwarding operation. The failure event may be with respect to a control link between a network-controlled repeater and a base station, such as a radio link failure or failure to comply with a configuration.

The present disclosure relates to base station and beam joint prediction and handover assisted by artificial intelligence. There is provided a method for radio communication, comprising: predetermining that a radio link failure (RLF) or handover will occur by using an artificial intelligence (AI) model, wherein, the predetermination is based at least on radio link condition information related to a user equipment (UE), and the radio link condition information comprises at least information reflecting condition of a radio link between the UE and a serving base station (SBS).

A communication method using a relay apparatus including a relay device that performs relay operation of relaying a radio signal transmitted between a network and a user equipment, and a control terminal that receives a control signal used for control of the relay device from the network, the communication method including the steps of: starting, by the control terminal in a radio resource control (RRC) connected state in a first cell, an RRC connection re-establishment procedure to a second cell based on detection of a radio link failure (RLF) in the first cell; and controlling, by the relay apparatus, the relay operation based on whether the second cell is the same cell as the first cell when the RRC connection re-establishment to the second cell is successful.

In some examples of the techniques described herein, a user equipment (UE) may utilize an artificial intelligence (AI) model to predict whether radio link failure (RLF) will occur. For instance, a network entity may configure the UE to report a prediction of the occurrence of a RLF based on beam or cell-level measurements performed on the cell. In some approaches, the configuration may include a time of prediction for RLF and one or more thresholds or conditions for triggering the report. The UE may utilize the configuration(s) to predict a probability of RLF and to report the prediction if the one or more thresholds or conditions are satisfied. The prediction may be utilized to trigger the measurement or configuration of one or more candidate cells for a potential handover. Configuring the UE to predict whether RLF will occur may enable flexibility in how an AI model is utilized.