The disclosure relates to a communication method and system for converging a 5.sup.th-Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure provides a method and an apparatus for operating a PDCP entity during a handover having no transmission/reception interruption.

The present disclosure provides a secondary cell group (SCG) maintenance method, a terminal device and a network node. The SCG maintenance method includes: receiving conditional SCG change information transmitted by a network node; evaluating, according to the conditional SCG change information, whether one or more target cells of an SCG meet a condition corresponding to triggering target cell change, to obtain an evaluation result; according to the evaluation result, triggering a SCG target cell changing procedure.

A optical wireless communication system, method and apparatus for use in the optical wireless communication system, that enable communication of data, e.g. LiFi, and wherein fast handover can be achieved by having neighboring access points (AP1, AP2) announce themselves using very short frames, that get picked up by user devices (EP1) that detect the identity of a neighbor access point (AP2) and then communicate this to the current access point (AP1) to share information on the user device (EP1) with its neighbor access point (AP2), so that the neighbor access point (AP2) can be pre-configured to allocate resources and/or synchronize.

Provided are a method for performing wireless communication by a first device, and an apparatus for supporting same. The method may comprise: establishing a radio resource control (RRC) connection with a first base station; establishing a PC5 connection with a second device; receiving an RRC reconfiguration message for handover from the first base station; establishing an RRC connection with a second base station based on the RRC reconfiguration message; and based on (i) the first device which is a relay device relaying communication between the second device and the first base station, and (ii) the first device establishing the RRC connection with the second base station, transmitting information regarding relay reselection to the second device.

A wireless transmit/receive unit (WTRU) may receive, from a serving cell based on the measurement report, a conditional reconfiguration message that includes a trigger condition and configuration information for handover to a target cell based on the trigger condition. The conditional reconfiguration message may be stored and the WTRU monitors trigger quantities of the serving cell and the target cell for the trigger condition being met. When the trigger condition is met within a validity period, then the WTRU applies the received configuration information and starts the handover to the target cell.

A first network node transmits, to a wireless device, a first indication. The first indication indicates to select, out of a plurality of target links simultaneously fulfilling a respective condition to switch from a source link to a target link, a first target link to switch from the source link to the selected first target link. The selecting is based on at least one of: a Reference Signal Received Power (RSRP) value, a Reference Signal Received Quality (RSRQ) value, a Signal to Interference and noise ratio (SINR) value, a priority, Random Access Channel (RACH) resources, a cell in which latest measurements were made, or a frequency, of the respective target links in the plurality of target links. The first network node then handles the link switch from the source link to the target link, based on the transmitted first indication.

Embodiments of this application provide an information transmission method, an apparatus, and a system. A first network device sends, to a terminal device, conditional handover configuration information that includes information about candidate cells and a handover trigger condition; after receiving the conditional handover configuration information and performing a conditional handover, the terminal device sends, to a second network device, a first failure cause value corresponding to a candidate target cell and/or a second failure cause value corresponding to a to-be-determined cell during the conditional handover; and the second network device receives the first failure cause value and/or the second failure cause value from the terminal device, and sends the first failure cause value and/or the second failure cause value to the first network device.

Systems and methods are described herein for pre-steering traffic within a telecommunications network. In some embodiments, the systems and methods pre-steer traffic by steering user devices to optimal or suitable frequency bands of a network before the user devices begin streaming content and/or performing other actions via the network.

An operation method of a terminal includes receiving configuration information from a serving base station; measuring channel states of the serving base station and a target base station; when a difference between received signal strengths of the serving base station and the target base station is not less than a handover preparation offset, determining that a handover preparation event has occurred and transmitting a measurement report message to the serving base station; and when the difference is equal to or greater than a handover execution offset, determining that a handover execution event has occurred and transmitting a handover indication message informing of execution of a handover to the target base station. The channel state is normal state, abnormal state, or RLF state, and the configuration information indicates a different handover preparation offset and a different handover execution event according to the channel state.

A wireless device, a network node and methods therein are provided for achieving an improved link utilization. The method in a wireless device comprises obtaining a configuration related to a first and a second set of resources which the wireless device may use for requesting communication resources from the network. The method further comprises requesting communication resources for uplink or downlink communication using at least one resource from each set of the first and second set. The method further comprises: when a criterion related to at least one of the first and second set is fulfilled: entering a fallback scheme associated with the fulfilled criterion.