The present disclosure provides a wireless communication system cooperation method appropriate for cooperation between a mobile communication system and a wireless LAN system involving priority control. In a communication area of 5G, a 5QI representing communication quality is allocated to a service data flow, and the communication of the service data flow is performed via a base station so that the communication quality is realized. A priority condition corresponding to 5QI is set for a frequency resource of the wireless LAN (step 100). When the wireless terminal UE to be protected is handed over to the wireless LAN (step 102), a priority condition set based on 5QI is instructed to the access point (step 106). Thereafter, the access point performs communication of the service data flow according to the priority condition.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may start, at a default data subscription (DDS) of the UE, a timer associated with a non-Third Generation Partnership Project (non-3GPP) tunnel over a cellular network based at least in part on a DDS switching at the UE. The UE may determine, at the DDS, that the non-3GPP tunnel over the cellular network is available prior to an expiry of the timer. The UE may perform a handover of a non-3GPP tunnel over data connection to the DDS based at least in part on the DDS switching at the UE and the non-3GPP tunnel over the cellular network being available prior to the expiry of the timer. Numerous other aspects are described.

Disclosed are methods for multicast broadcast service. One embodiment of the subject application provides a method performed by a UE, comprising receiving data packets in a first cell in a first mode, sending a data receiving status report during or after a handover and/or during or after a data transmission mode switching, receiving missing data packets during the data transmission mode switching and/or during the handover, and receiving data packets in a second cell in a second mode. Related apparatuses are also disclosed.

In accordance an embodiment of the disclosure, a method performed by a user equipment (UE) in a wireless communication system is provided. The method may comprise: identifying an inter-system change from a first mode to a second mode, transferring a data session established in the first mode to the second mode from the first mode, determining whether the UE and a network entity in the second mode support a header compression, and initiating, based on a result of the identifying, a procedure for negotiating a header compression configuration in the transferred data session, wherein the first mode is one of N1 an mode or an S1 mode, and the second mode is the other of the N1 mode or the S1 mode.

Solutions for providing a voice call for a user equipment (UE) include: monitoring, by a voice service control, voice call key performance indicators (KPIs) for the voice call of the UE, when the voice call comprises a voice over new radio (VoNR) call; determining, by the voice service control, that the voice call KPIs do not meet acceptable performance criteria; determining, by the voice service control, that an eNodeB (eNB) is co-located with a gNodeB (gNB) that is serving the UE; based on at least determining that the voice call KPIs do not meet acceptable performance criteria, and determining that an eNB is co-located with the serving gNB, instructing, by the voice service control, a radio access network (RAN) to begin an inter-radio access technology (IRAT) handover (HO) for the UE to the co-located eNB; and continuing the voice call as a voice over long term evolution (VoLTE) call.

A method performed by a target network node for interworking handover from an evolved packet system, EPS, to a fifth generation system, 5GS, in a mobile network is provided. The method includes receiving, from a source network node, a determined user plane, UP, encryption policy. The method further includes providing the determined UP encryption policy to a target radio access network node. Corresponding embodiments for methods performed by a source network node and a first target network node are also provided.

According to one embodiment, a method for establishing a communication is described comprising performing, over a first mobile radio communication network, a call control protocol message exchange indicating that a communication session establishment between a first communication device and a second communication device is intended; initiating a fallback by the first communication device from the first mobile radio communication network to a second mobile radio communication network, in reaction to a specific call control message of the call control protocol message exchange; performing the fallback and establishing the communication session between the first communication device and the second communication device via the second mobile radio communication network.

Systems, methods, apparatuses, and computer-program products for performing carrier aggregation across different radio access technologies are disclosed. For example, in some instances a method of wireless communication includes transmitting, using a first wireless communication device, control information to a second wireless communication device via a first radio access technology (RAT), the control information including control information for a second RAT; and receiving, at the first wireless communication device, an acknowledgement (ACK) or negative acknowledgement (NACK) from the second wireless communication device via the first RAT, the ACK or NACK being related to communications of the second wireless communication device conducted via the second RAT.

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present 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. Systems and methods provide a service that effectively transmits or receives data simultaneously using a 3GPP system, such as Long Term Evolution (LTE), and a non-3GPP system, such as a Wireless Local Area Network (WLAN), in a network where the 3GPP system and the non-3GPP system coexist. Particularly, this is a technology of selecting an access network through which data is to be transmitted based on a user's preference and a network condition so as to improve the quality of a service that a user experiences during data transmission.

A method of performing intersystem change without N26 interface supported or not supported when a UE is registered to the same or different networks over 3GPP and non-3GPP accesses is proposed. UE registers to one or more PLMN/SNPN over 3GPP access and non-3GPP access. UE receives a REGISTRATION ACCEPT message over 3GPP access, which carries a first 5GS network feature support IE, which indicates that interworking without N26 interface not supported. UE also receives a REGISTRATION ACCEPT message over non-3GPP access, which carries a second 5GS network feature support IE, which indicates that interworking without N26 interface supported. UE ignores the second indication received over non-3GPP access and considers that N26 interface is supported for interworking. As a result, after intersystem change from 5G to 4G, UE triggers a TAU procedure over LTE in 4G EPS.