A UE may perform a location-based conditional handover (CHO) based on a region information and size parameter associated with a serving cell of a non-terrestrial network (NTN). In time-based CHO, the UE may perform CHO in response to expiration of a network-configured wait time. Alternatively, the UE may perform CHO by randomly selecting a wait time from a network configured time range. The selection may be randomized using a network provided seed or using a cell Radio Network Temporary Identifier (RNTI) value. In elevation-based CHO, the UE may perform CHO in response to the elevation angle of a satellite being less than a network configured threshold. When the UE is configured with multiple cells of the NTN, and the CHO criteria for two or more of the cells are satisfied, the UE may select a target cell for CHO based on network indicated prioritization of the cells.

The present application relates to devices and components including apparatus, systems, and methods to provide positional information for one or more NTN devices to a UE to be utilized for one or more UE operations.

A signal measurement method and apparatus, and a communication device and a storage medium are provided. The method includes that a first communication device receives, via a first type of network, a measurement result, sent by a second communication device, for a second type of network.

Systems, methods, apparatuses, and computer program products for mobility failure evidence-related operations. A UE may measure, record, and report a channel access waiting (CAW) time period that elapsed from having a handover-related message in a transmission buffer until a channel for transmission of the handover-related message was obtained or until an acknowledgement or negative acknowledgement from a receiver of the handover-related message was received. The CAW time period information may be provided to a network node, and the network node may control mobility robustness optimization based on the received information.

An operation method of a terminal in a communication system may comprise: receiving a first occurrence reporting condition of a handover problem from a source base station; performing a handover from the source base station to a target base station; identifying whether a handover problem occurs based on the first occurrence reporting condition while performing the handover; and in response to identifying that a handover problem occurs, transmitting information indicating the occurrence of the handover problem to the target base station.

An embodiment of the present disclosure may provide an inter-MeNB handover method in a small cell system, including: making, by a source MeNB and/or target MeNB, a determination as to whether to maintain a SeNB when handover is performed; and triggering different handover processes according to a result of the determination as to whether to maintain the SeNB. Another embodiment of the present disclosure may further provide an inter-MeNB handover device in a small cell system. With the inter-MeNB handover method and device in a small cell system provided by the present disclosure, unnecessary deletion and re-establishment of the bearers at the SeNB for the UE may be reduced. False bearer deletion may be avoided and data forwarding may be reduced. Furthermore, the SeNB may be maintained according to network deployment and SGW re-selection may be supported. Therefore, system capacity and transmission speed of the data may be improved.

A method and apparatus for cell update while in a Cell_FACH state are disclosed. After selecting a target cell, system information is read from the target cell including high speed downlink shared channel (HS-DSCH) common system information. A radio network temporary identity (RNTI) received in a source cell is cleared and a variable HS_DSCH_RECEPTION is set to TRUE. An HS-DSCH medium access control (MAC-hs) entity is configured based on the HS-DSCH common system information. High speed downlink packet access (HSDPA) transmission is then received in the target cell. A CELL UPDATE message is sent to notify of a cell change. The HSDPA transmission may be received using a common H-RNTI broadcast in the system information, a reserved H-RNTI as requested in a CELL UPDATE message, or a temporary identity which is a subset of a U-RNTI. The MAC-hs entity may be reset.

We disclose various embodiments of methods and apparatus for processing handovers of mobile terminals between base stations of a wireless communication system. An example handover algorithm used for this purpose enables the handover threshold to be increased for some mobile terminals, on a terminal-by-terminal basis, thereby individually expanding the range of the serving cell for each of such terminals. In an example embodiment, the handover-threshold determination is carried out based on physical-resource-block usage of the target cell. The extent of the cell-range expansion depends on whether or not the reference signals of the serving and target cells interfere with each other. Embodiments of the disclosed handover algorithm can advantageously reduce the number of failed handovers by allowing some communication sessions to run to completion before a handover is triggered.

An apparatus and method are disclosed for mitigating pointing errors resulting from satellite antennas. Reports are received from terminals in a beam hopping satellite communication system, and a pointing error associated with a satellite antenna is determined. The best beam for communicating with each terminal is selected based on the pointing error. A beam list containing the instantaneous traffic demand of terminals for each beam in the system is generated. An active beam set is then selected from the beam list for transmitting data during the next hop in the satellite communication system.

Conditional handover (CHO) configurations may include random access channel (RACH) configuration information (e.g., beam quality thresholds, beam quality threshold offsets, one or more beams associated with configured contention free random access (CFRA) resources, one or more beams associated with configured contention based random access (CBRA) resources, or some combination thereof). A user equipment (UE) may, upon detection that a handover condition in a CHO configuration has been satisfied, select a target cell beam for transmission of a random access request based on the RACH configuration information included in the CHO configuration. In various examples, the selected beam may correspond to a highest quality beam with a highest quality beam measurement value above the beam quality threshold, a beam with an earliest configured CFRA resource or an earliest configured CBRA resource (e.g., if a corresponding beam measurement at least falls within the beam quality threshold offset), etc.