Methods and apparatus, including computer program products, are provided for user-plane switching of traffic for dual connectivity. In some example embodiments, there is provided a method. The method may include receiving, at a serving gateway, an indication to persist a first tunnel identifier located at a master base station, while the serving gateway sends, towards a second tunnel identifier located at a secondary node, user plane traffic for a user equipment in dual connectivity with the master base station and the secondary node; and switching, at the serving gateway, the user plane traffic between the second tunnel identifier and the first tunnel identifier, when the serving gateway receives, via a user plane, an error indication and/or a switch indication. Related apparatus, systems, methods, and articles are also described.

User equipment included in a wireless communication system wirelessly connects to a donor base-station to establish a macro link, wirelessly connects to a mobile relay to establish an access link, and simultaneously maintains connections with the donor base-station and the mobile relay coexisting in the same coverage area, wherein a first pre-established frequency band can be used for the access link and a second pre-established frequency band can be used for the macro link. Furthermore, the user equipment can wirelessly connect to the mobile relay to establish an access link, be assigned, from the mobile relay, a wireless resource for device-to-device communication with at least one other user equipment within the same mobile relay cell, and perform device-to-device communication with the at least one other user equipment using the assigned wireless resource.

Methods, systems and apparatus are provided for camping, assisted serving cell addition or removal, and discontinuous reception (DRX) in networks having a macro cell and at least one assisted serving cell. In other aspects, enhancements to Layer 1 channels and uplink timing alignments are provided in networks having a macro cell and at least one assisted serving cell. In further aspects, assisted serving cell Layer 2 architecture and transport channels are provided in networks having a macro cell and at least one assisted serving cell. In further aspects, collaborated HARQ solutions are provided in networks having a macro cell and at least one assisted serving cell.

One embodiment of the present invention provides an apparatus comprising a transceiving unit and a control unit, and a communication method using the same, wherein the transceiving unit is configured to perform communication with at least one network node in a macro cell, the macro cell comprising at least one small cell and communicating in an FDD mode, and wherein the control unit is configured to control the small cell to communicate in a TDD mode, generate control information for preventing the occurrence of handover when a terminal moves between the small cells within the macro cell, and perform control to transmit the control information to the terminal.

A master RAN node (1) sends, to a control plane function (5) in a core network (4), a modification request for modification of a first PDU session already established between a radio terminal (3) and a user plane function (6) in the core network (4). The modification request implicitly or explicitly indicates that PDU session split is needed for the first PDU session. The modification request causes the control plane function (5) to control the user plane function (6) to move a specific one or more QoS flows of a plurality of QoS flows associated with the first PDU session from a first tunnel between the user plane function (6) and the master RAN node (1) to a second tunnel between the user plane function (6) and a secondary RAN node (2). This contributes, for example, to implementing PDU session split in a radio communication network.

A method for improving service reliability includes deciding, by a session function entity in a network, to initiate establishment of at least two transmission paths between a terminal and the user plane function entity, and instructing the terminal or the user plane function entity to transmit same data on the at least two paths. The user plane function allocates, based on a notification of the session function entity, user plane resources to the at least two transmission paths, and transmits the same data with the terminal on the at least two transmission paths. A core network initiates the establishment of the at least two transmission paths to the terminal. Two access devices may independently establish the at least two transmission paths.

Apparatuses, systems, and methods for a wireless device to perform master cell group failure recovery in a dual connectivity cellular communication system. The wireless device may establish a first wireless link to a cellular network via a first cell group. The first cell group may be configured as a master cell group for the wireless device. The wireless device may establish a second wireless link to the cellular network via a second cell group. The second cell group may be configured as a secondary cell group for the wireless device. The wireless device may determine that link failure for the first wireless link has occurred. The wireless device may perform master cell group link failure recovery using the second wireless link based at least in part on the link failure for the first wireless link.

A method of operating a network node to provide dual connectivity in a new radio telecommunications system. The method allocates two tunnel endpoint identifiers (TEIDs). The method sends the allocated TEIDs to at least one other network node for transporting a Protocol Data Unit (PDU) session that can be split. The method receives two TEIDs for a master node and a secondary node (SN). A related method of operating a master node provides dual connectivity. The method sends a SN addition request message to a SN. The method sends a SN add/modify completion indication to the SN that informs the SN that the operations to add/modify are complete.

A communication system is described in which user plane communication and control plane communication for a particular mobile communication device can be split between a base station that operates a small cell and a macro base station. Appropriate security for the user plane and control plane communications is safeguarded by ensuring that each base station is able to obtain or derive the correct security parameters for protecting the user plane or control plane communication for which it is responsible.

A communication system is described in which user plane communication and control plane communication for a particular mobile communication device can be split between a base station that operates a small cell and a macro base station. Appropriate security for the user plane and control plane communications is safeguarded by ensuring that each base station is able to obtain or derive the correct security parameters for protecting the user plane or control plane communication for which it is responsible.