Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a source master eNodeB (MeNB) may transmit, to a target Next Generation radio access network (NG-RAN) node, a handover required message to initiate an inter-system handover from an evolved-Universal Mobile Telecommunications System (UMTS) terrestrial radio access network (E-UTRAN) New Radio (NR) dual connectivity (EN-DC) system associated with the source MeNB to an NR standalone (SA) system associated with the target NG-RAN node. The source MeNB may have an indirect path to the target NG-RAN node and a source secondary gNodeB (SgNB) may have a direct path to the target NG-RAN node. The source MeNB may transmit, to the target NG-RAN node and based at least in part on the handover required message, forwarded data via the indirect path between the source MeNB and the target NG-RAN node through a core network. Numerous other aspects are described.

This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios, where each of the radios is configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); one or more processors coupled to the one or more radios, where the one or more processors are configured to cause the UE to perform operations including: sending, via a first RAT, a first request for IMS registration to an IMS server; receiving, from the IMS server, an IMS rejection message indicating failure of the IMS registration; determining, based on the IMS rejection message, that the IMS registration failure is temporary; responsively re-attempting IMS registration with the IMS server; and determining to camp on the first RAT in response to receiving an IMS acceptance message from the IMS server.

A method and apparatus for selecting a NR cell in a mobile communication system are provided. Method for selecting a NR cell includes selecting, by a terminal, a first cell, acquiring, by the terminal in the first cell, a MIB, acquiring, by the terminal in the first cell, a SIB1 based at least in part on a first information in the MIB, considering, by the terminal, the first cell as barred, performing, by the terminal a first operation group if the SIB1 received in the first cell does not include a intraFreqReselection and performing, by the terminal a second operation group if the SIB1 received in the first cell includes the intraFreqReselection and the second intraFreqReselection is set to NotAllowed.

A method and apparatus for selecting a NR cell in a mobile communication system are provided. Method for selecting a NR cell includes selecting, by a terminal, a first cell, performing, by the terminal a first operation group if the terminal fails to acquire MIB in the first cell and performing, by the terminal a second operation group if the terminal succeeds to acquire MIB and SIB1 in the first cell and the MIB includes cellBarred set to barred and the SIB1 includes a intraFreqReselection set to NotAllowed.

A method and an apparatus for terminating a cellular network connection of a terminal that is connected without authentication are provided. The disclosure relates to a communication technique and a system for fusing a 4th generation (4G) system and a 5th generation (5G) communication system to support higher data rates, which is subsequent to the 4G system, with Internet-of-things (IoT) technology. The disclosure may be applied to intelligent services (e.g., smart home, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail business, security and safe-related services, or the like) based on 5G communication technology and IoT-related technology.

A condition handover cancellation method and a communication equipment are provided. A CHO cancellation method applied to a source network side device includes: sending a CHO request to at least one target network side device; and sending a CHO cancellation message to the target network side device and/or a terminal side device.

There are provided a method of managing radio connectivity of a vehicle and a system thereof. The method comprises: continuously receiving by vehicle's telematic system a predictive model generated by remote system using data continuously collected from a plurality of vehicles, wherein the collected data comprise, for each given vehicle of the plurality of vehicles, data informative of its location, speed and of Radio Access Technology (RAT)-related measurements; and, responsive to a predefined event, applying, by the telematic system, a lastly received predictive model to current values of a predefined set of inputs associated with the vehicle to obtain instructions and respectively provide corrective actions related to radio connectivity of the vehicle. The corrective actions include modifying RRC measurement report(s) so as to force the cellular network to provide one of: intra-RAT handover, inter-RAT handover; excluding available connectivity with undesired RAT or band; and terminating the radio connectivity with further RAT re-selecting.

A method and system for performing handover in a third generation (3G) long term evolution (LTE) system are disclosed. A source evolved Node-B (eNode-B) makes a handover decision based on measurements and sends a handover request to a target eNode-B. The target eNode-B sends a handover response to the source eNode-B indicating that a handover should commence. The source eNode-B then sends a handover command to a wireless transmit/receive unit (WTRU). The handover command includes at least one of reconfiguration information, information regarding timing adjustment, relative timing difference between the source eNode-B and the target eNode-B, information regarding an initial scheduling procedure at the target eNode-B, and measurement information for the target eNode-B. The WTRU then accesses the target eNode-B and exchanges layer 1/2 signaling to perform downlink synchronization, timing adjustment, and uplink and downlink resource assignment based on information included in the handover command.

A method of operating a second network access node comprises configuring the second network access node to act as a secondary network access node for a dual connectivity mode for a terminal device in which a first network access node acts as a master network access node. The method further comprises establishing, while acting as a secondary network access node for the dual connectivity mode, that the second network access node should switch to acting as a master network access node, deriving a new master network access node security key for use by the second network access node when switched to acting as a master network access node for the dual connectivity mode, and configuring the second network access node to act a master network access node for the dual connectivity mode using the new master network access node security key.

A method for a conditional Primary Secondary Cell Group (SCG) Cell (PSCell) change (CPC) procedure performed by a user equipment (UE) is provided. The method includes: receiving, from a master node, a conditional reconfiguration for changing from a source PSCell to a target PSCell in an SCG portion of a radio resource control (RRC) reconfiguration message, the conditional reconfiguration including a configuration of the target PSCell and an execution condition; evaluating the execution condition; applying the configuration of the target PSCell and synchronizing to the target PSCell after determining that the execution condition is satisfied; and transmitting, to the master node, a response message after determining that the conditional reconfiguration is applied.