866 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.

Embodiments of the present application relate to methods and apparatuses for a mobility robustness optimisation (MRO) mechanism. According to an embodiment of the present application, a UE includes a processor and a wireless transceiver coupled to the processor; and the processor is configured: to store information including distance information associated with a distance between the UE and a reference location, wherein the information is at least one of radio link failure (RLF) related information, handover failure related information, or handover success related information; and to transmit the information via the wireless transceiver to a network node.

A method in a sidelink, SL, user equipment, UE, configured with SL carrier aggregation, CA, to handle SL radio link failure, RLF, per SL carrier includes monitoring at least one of radio channel quality, radio link control, RLC, transmission, or hybrid automatic repeat request, HARQ, discontinuous transmission, DTX, per SL carrier. The method includes for each SL carrier, responsive to determining there is a SL RLF in the SL carrier: reporting SL RLF to at least one peer SL UE using at least one SL carrier of SL carriers that are not failed in a SL carrier configuration associated with the SL carrier having the SL RLF; and when the SL UE is connected to a base station, gNB, reporting the SL RLF to the gNB.

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.

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.

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.

The invention provides a wireless communication method, terminal equipment and network equipment. The method comprises: during the operation of a first timer, a terminal device sends first information to a network device, the first information being used for indicating a prediction result of a radio link failure (RLF) occurring in a radio link between the terminal device and the network device determined based on a model; wherein the first timer is triggered based on a physical layer fault detected by the terminal device. In the embodiments of the present application, during the operation of a first timer triggered based on a physical fault detected by a terminal device, the terminal device sends first information to a network device, the first information being used for indicating a prediction result of RLF occurrence of a wireless link between the terminal device and the network device determined based on a model. Based on the first information, the network equipment is helped to improve the wireless link quality before the RLF occurs, so that interruption of data transmission caused by the RLF is avoided.

Embodiments include methods, performed by a user equipment (UE), for reporting radio link failure (RLF) in a cell of a wireless network. Such methods include performing measurements of a plurality of cells, which can include a serving cell and multiple neighbor cells. The measurements for each cell are based on one or more types of reference signals (RS) transmitted in the particular cell and include one or more measurement quantities. Such methods include determining that an RLF occurred in the serving cell and sorting the neighbor cell measurements into one or more measurement lists based on one or more sorting criteria, which can be related to the RS types on which the measurements for the respective neighbor cells are based and / or the measurement quantities available for the respective neighbor cells. Such methods include transmitting, to a network node, an RLF report including the one or more measurement lists.

A fallback configuration is prepared for one of a Radio Link Failure (RLF) or a handover (HO) failure of a User Equipment (UE). Layer 1 (L l) / Layer 2 (L2) Triggered Mobility (LTM) candidate cells are identified for fallback. An HO failure or an RLF is predicted for LTM target cells and at least one of a fallback LTM configuration or a fallback Conditional Handover (CHO) configuration is prepared for a target cell selected from the one or more LTM candidate cells. The UE is provided with the at least one of the prepared fallback LTM configuration or the fallback CHO configuration for the target cell. Control information is sent to the UE to initiate a cell switch by the UE from a serving cell to the target cell based on the at least one of the prepared fallback LTM configuration or the fallback CHO configuration for the target cell.

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 a device for processing global navigation satellite system (GNSS) validity. The method is performed by a terminal device, and includes: setting a target parameter of radio link failure (RLF), in a case that a GNSS of the terminal device is outdated.

A user device, a method, and a computer program product enable conditional requests by a user device based on predicting a radio link failure due to a terrestrial object. A communication subsystem of the user device receives communication service by a currently serving satellite of a constellation of satellites in low earth orbit (LEO). The serving satellite has a field of view encompassing a target area surrounding the user device. A controller of the communication device determines a location of the user device and tracks trajectories and corresponding fields of view of the constellation of LEO communication satellites. In response to predicting a radio link failure due to a terrestrial obstruction, the controller triggers completion of a conditional handover of radio link to a target satellite that is not predicted to have a radio link failure due to a terrestrial obstruction.

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.

This application provides a communication method and apparatus, so that a terminal device reports an RLF report related to whether link recovery for an MCG succeeds. The terminal device separately communicates with a first network device and a second network device, where the first network device manages a first MCG, the second network device manages a first SCG, and an MCG link recovery function is configured for the first SCG. After determining that a radio link failure RLF occurs in the first MCG, the terminal device sends a first RLF report to a third network device, where the first RLF report is related to whether link recovery for the first MCG succeeds.

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.

The present invention provides a method performed by user equipment, and user equipment. The method is a processing method performed in a procedure wherein a remote user equipment (UE) A and another remote user equipment (UE) B set up a sidelink (SL) connection or a PC5 connection by means of a relay UE, including the following step: when scenario I or a scenario II described below occurs between one of the UE A and UE B and the relay UE, initiating, by the relay UE, a notification procedure to notify the other one of the UE A and UE B, scenario I being that a radio link failure (RLF) has occurred on the SL connection or the PC5 connection between the one of the UE A and UE B and the relay UE, and scenario II being that the relay UE has received a request from an upper layer to release the PC5 connection or the SL connection with the one of the UE A and the UE B.

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.

An integrated access and backhaul (IAB) node equipped with at least two radio interfaces comprising a first interface and a second interface, the first interface being configured to establish a first radio link with at least one parent node, the second interface being configured to establish a second radio link(s) with one or more wireless terminals, the IAB node comprising:processor circuitry configured to: detect a radio link failure (RLF) on the first radio link for the first interface, and; perform a re-establishment procedure on the first radio link for the first interface to re-establish a radio resource control (RRC) connection with at least one parent node; transmitter circuitry configured to transmit, on the second radio link for the second interface, an RLF notification to the one or more wireless terminals; wherein; the RLF notification indicates that the re-establishment procedure has failed.

A wireless device receives one or more parameters indicating a plurality of sidelink carriers, a discontinuous transmission (DTX) threshold value, and a channel busy ratio (CBR) threshold value for a sidelink carrier selection procedure. The wireless device selects one or more first sidelink carriers from the plurality of sidelink carriers. The wireless device determines that the number DTXs on at least one sidelink carrier is equal to the DTX threshold value. Based on the determining, the wireless device triggers the sidelink carrier selection procedure and transmits a message indicating the at least one sidelink carrier. The wireless device selects, during the triggered sidelink carrier selection procedure and based on a CBR being below the CBR threshold value, a third sidelink carrier from the plurality of sidelink carriers. The wireless device transmits, to the second wireless device, a sidelink transport block (TB) via the third sidelink carrier.

Techniques are described for mitigating the negative effects of temporary loss of connectivity or temporary loss of service between a RU and a BU. In embodiments of the present disclosure, the radio unit is configured to transmit reference signals during a temporary loss of connectivity with the baseband unit to allow the UEs served by the radio unit to maintain synchronization with the radio unit and avoid or minimize radio link failures. Applying these techniques, the UEs served by the radio unit can maintain connection with the radio unit during the temporary outage and avoid the need to engage in Radio Resource Control (RRC) signaling to re-establish a connection with the radio unit and / or handover to neighboring radio units.

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.

The present application relates to methods and apparatuses for handling failure. According to some embodiments of the present application, a user equipment (UE), includes a processor; and a receiver coupled to the processor, the receiver being configured to receive a radio resource control (RRC) reconfiguration message from a source node which manages a source cell, the RRC reconfiguration message including both conditional handover (CHO) configurations and per data radio bearer (DRB) dual active protocol stack (DAPS) HO indication for each candidate cell of one or more candidate cells; wherein the processor configured to: perform a first handover procedure to a first target cell selected from the one or more candidate cells; and in response to a failure of the first handover procedure, perform fallback to the source cell when at least one of the following conditions is met: a cell quality of the source cell is higher than or equal to that of each candidate cell of the one or more candidate cells, and there is no radio link failure (RLF) in the source cell; the source cell is selected by a cell selection procedure with configurations of the source cell maintained; the cell quality of the source cell is higher than a threshold; or an indication indicating that the UE is to perform fallback to the source cell is received.