Abstract: Provided are methods and related devices for implementing disaster recovery. According to a method, in a case where a main Session Management Function (SMF) fails, a backup SMF sends a first request to a User Plane Function (UPF), wherein the first request carries a node identifier (Node ID) of the main SMF, a Node ID of the backup SMF, and a Common Session endpoint Identifier List (CSIDLIST) corresponding to the backup SMF; and the first request is used for notifying the UPF that the main SMF fails and a session or sessions in the CSIDLIST corresponding to the backup SMF is/are to be taken over by the backup SMF, so that the UPF subsequently interacts with the backup SMF for the session or sessions in the CSIDLIST corresponding to the backup SMF.

Abstract: A random access method includes sending a random access preamble to a base station on a first time domain resource, obtaining an index value of the first time domain resource, obtaining an index difference between the first time domain resource and a second time domain resource, obtaining an index value of the second time domain resource by adding the index value of the first time domain resource and the index difference, obtaining a random access radio network temporary identifier (RA-RNTI) based on the index value of the second time domain resource, receiving a random access response (RAR) from the base station, and descrambling a cyclic redundancy check (CRC) code of the RAR using the RA-RNTI.

Abstract: A key generation method includes determining, by an access and mobility management function node, key-related information. The method also includes sending, by the access and mobility management function node, a redirection request message to a mobility management entity. The redirection request message includes the key-related information, and the redirection request message is used to request to hand over a voice service from a packet switched (PS) domain to a circuit switched (CS) domain. The method further includes receiving, by the mobility management entity, the redirection request message. The method additionally includes generating, by the mobility management entity, an encryption key and an integrity protection key for the voice service based on the key-related information.

Abstract: Disclosed are systems and methods for providing a differentiated neighbor list that can be individually generated for a specific service (e.g., per service) based on network service information, which can include, but is not limited to, a user equipment (UE) group identifier (ID), network slicing and/or quality of service (QoS) flow, and the like. Neighbors within the differentiated list can be characterized based on, but not limited to, service types, distance to devices, transport costs, service locations, and the like, or some combination thereof. The disclosed framework can generate and dynamically update a differentiated neighbor list for specific types of services so that optimal neighbor selection is performed for the type of service a UE is operating within to ensure that a network connection is maintained at a threshold satisfying QoS.

Abstract: To facilitate a handover of mobile devices from 4th Generation (4G) networks to 5th Generation (5G) networks, a mobility management entity (MME) of the 4G network core inactivates a data session in which the mobile device is assigned an Internet protocol version 4 (IPv4) address. The MME generates a modified context of the mobile device that omits the IPv4 address of the device. The inactivation of the IPv4 session causes the mobile device to initiate a new data session with the 5G core network, in which the device will be assigned a new IPv6 address for use on a data network. The modified context is used by the 5G network to configure communications for the mobile device without interrupting network service to the mobile device.

Abstract: Disclosed is a method of ensuring a service continuity based on a utility slice in case of a handover. The method includes receiving a handover request message from a source base station when a user equipment (UE) moves from a coverage of the source base station to that of a target base station, setting a session for the UE based on slice information included in the handover request message, and transmitting a handover request acknowledgment (ACK) message for the handover request message to the source base station, wherein the target base station may provide, when a service slice corresponding to a service provided from the source base station to the UE through a protocol data unit (PDU) session is not supported by the target base station, the service using a utility slice.

Abstract: A communications method, and apparatus are provided, to reduce a transmission latency when a plurality of HARQ-ACKs are transmitted in one time unit. The method includes: determining, in N groups of time-frequency resources based on the grouping relationship, the ith group of time-frequency resources corresponding to a first parameter related to the first DCI, receiving first DCI, and determining a first uplink channel that carries a first HARQ-ACK on a first time-frequency resource in the ith group of time-frequency resources, where the grouping relationship represents a correspondence between a first parameter and N groups of time-frequency resources, the N groups of time-frequency resources are obtained by grouping time-frequency resources in one time unit, each group of time-frequency resources corresponds to one or more first parameters, and the first parameter is related to DCI, a time-frequency resource in each group of time-frequency resources is for an uplink channel carries a HARQ-ACK.

Abstract: A method for a handover procedure comprises establishing a connection with a source network node of a first core network; receiving a radio resource control (RRC) message including an information element, wherein the information element indicates a second core network associated with a target network node; applying security parameters based on the second core network indicated in the information element; and performing a handover toward the target network node using the applied security parameters. The method provides an indication in RRC connection reconfiguration procedure to indicate the UE the core network of the target network node, so that the UE may recognize that this is an inter-system handover and apply corresponding security parameters for performing the handover without additional signaling.

Abstract: An Access and Mobility Management Function (AMF) adapted for taking part in handover from a 5G system (5GS) to an Evolved Packet System (EPS).

Abstract: Techniques for using simultaneous connectivity for mobility of integrated access and backhaul nodes may include an IAB node establishing a first connection with a first parent node (e.g., second IAB node) associated with a first IAB donor device (e.g., first base station) and establishing a second connection with a second parent node (third IAB node), wherein the second connection is simultaneous with the first connection. The IAB node may also switch the first connection from the first parent node to the second parent node. In doing so, the IAB node may have dual connectivity with the second parent node, where one connection is a master connection and the other connection is a secondary connection.

Abstract: An apparatus and method are provided. The method includes reproducing, by a portable phone, multimedia content via an external output device while the portable phone is coupled with the external output device, determining whether the portable phone is decoupled from the external output device, and terminating the reproducing of the multimedia content based at least in part on a determination that the portable phone is decoupled from the external output device.

Abstract: 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.

Abstract: Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE). The method generally includes receiving lower layer signaling indicating that the UE is to handover to one or more first physical cell identifiers (PCIs) to be used for communication between the UE and the BS and communicating with the BS in accordance with a security key and using the one or more first PCIs, the security key being associated with a PCI.

Abstract: Embodiments include methods for a first node, configured to provide a serving cell to a user equipment (UE) in a radio access network, to determine core network types supported by a second node configured to provide neighbor cell(s) of the serving cell. Such embodiments include determining that a first cell identifier associated with a particular one of the neighbor cells is not included in a neighbor relations table maintained by the first node. Such embodiments also include sending, to the UE, a request to report a second cell identifier associated with the particular neighbor cell, the request including the first cell identifier. Such embodiments also include determining one or more core network types supported by the particular neighbor cell based on the content of a report from the UE. Other embodiments include complementary methods performed by a UE, as well as network nodes and UEs configured to perform such methods.

Abstract: Methods, systems and devices for wireless communications are described for differentiation between standalone (SA) and non-standalone (NSA) cells in a wireless communications system. A user equipment (UE) may receive an indication of a subcarrier offset for a system information block (SIB). The SIB may be for a cell of a wireless communications network. The cell may be in accordance with a radio access technology. The UE may determine, based on the subcarrier offset for the SIB, whether the cell is configured as an SA cell or as an NSA cell for the radio access technology. The UE may communicate via the wireless communications network based on whether the cell is configured as an SA cell or as an NSA cell.

Abstract: One disclosure of the present specification provides a method by which a UE performs sidelink communication. The method may comprise the steps of: performing sidelink communication on the basis of a first RAT; switching a RAT for the sidelink communication from the first RAT to a second RAT; performing the sidelink communication on the basis of the second RAT; and communicating with a base station on the basis of NR.

Abstract: Apparatuses, methods, and systems are disclosed for transmitting and/or receiving handover requests with network information. One method (1000) includes transmitting (1002) a handover request to a target device. The handover request includes: first information indicating that a source communication network corresponding to a source device is unable to support a predetermined quality of service; and second information corresponding to capacity of the source communication network. The method (1000) includes receiving (1004) a response to the handover request.

Abstract: A mechanism for controlling configuration of dual connectivity for a user equipment device (UE), where the dual connectivity includes the UE being served cooperatively by (i) a first access node over a first air-interface connection between the UE and the first access node and (ii) a second access node over a second air-interface connection between the UE and the second access node. An example method includes (a) predicting whether both (i) in the dual connectivity, a data split will put a threshold greater portion of data flow of the UE on the second air-interface connection than on the first air-interface connection and (ii) coverage strength of the UE from the second access node will be threshold lower than coverage strength of the UE from the first access node and (b) using the prediction as a basis to control whether or not to establish the dual connectivity for the UE.

Abstract: In a legacy gNB (e.g., pre-Rel. 17 gNB), RC UEs with only 1 or 2 receive antennas may have a geographic coverage area for control data and traffic data that is smaller than their geographic coverage area for SSB with respect to certain legacy gNBs. By contrast, at least some new gNBs (e.g., Rel. 17+ gNBs) have the capability to provide uniform geographic coverage for RC UEs with respect to SSB, control data and traffic data. In an aspect of the disclosure, a particular class of UEs (such as RC UEs) is steered towards particular cells (e.g., Rel. 17+ gNBs) via one or more biased class-specific cell selection parameters included in system information from the cells.

Abstract: Systems and methods are provided for seamless roaming in a network. First, a client device is authenticated at a first access point of the network. Next, a processor selectively determines, among remaining access points in the network, second access points at which respective precursor keys, such as Pairwise Master Keys R1 (PMK-R1s) are to be computed. The second access points are determined based on any of respective path losses from the first access point to the second access points and respective historical frequencies at which the client device associates at the respective remaining access points. For the second access points, the respective PMK-R1s are computed and transmitted to the second access points to be cached. Next, following a request from the client device to reassociate to a second access point of the second access points, the client device is authenticated at the second access point based on a corresponding PMK-R1.