WO2023280980A2

WO2023280980A2 - Dual connectivity technique

Info

Publication number: WO2023280980A2
Application number: PCT/EP2022/068910
Authority: WO
Inventors: Min Wang; Antonio ORSINO
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2021-07-08
Filing date: 2022-07-07
Publication date: 2023-01-12
Also published as: WO2023280980A3

Abstract

A technique for establishing a dual connectivity, DC (1500), of a wireless device is provided. As to a method aspect, a first path (1510) of the DC (1500) is established, wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210). A second path (1520) of the DC (1500) is established, wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

Description

Dual Connectivity Technique

Technical Field

The present disclosure relates to a technique for dual connectivity of a wireless device. More specifically, and without limitation, methods and devices are provided for establishing and controlling the establishing of a dual connectivity of a wireless device.

Background

The Third Generation Partnership Project (3GPP) defined sidelinks (SLs) in Release 12 as an adaptation of the Long Term Evolution (LTE) wireless (e.g., radio) access technology for direct communication between two wireless device (e.g., radio devices), also referred to as user equipment (UE), without going through a network node (e.g., a base station). Such device-to-device (D2D) communications through SLs are also referred to as proximity service (ProSe) and can be used for Public Safety communications. While conventional public safety communications use different standards in different geographical regions and countries, 3GPP SL communications enable interworking of different public safety groups. 3GPP has enriched SLs in Release 13 for public safety and commercial communication use-cases and, in Release 14, for vehicle-to-everything (V2X) scenarios.

SL relay is being standardized by the 3GPP for NR Release 17, which enables a remote UE to be able to connect to a network node (e.g., a gNB) via a relay UE. The remote UE may be in coverage (1C) or out of coverage (OOC).

The remote UE only allows to use a single connectivity to transmit data. Due to this restriction, it would be reasonable and straightforward for the remote UE to only use the indirect connection to transmit data to or via the gNB.

With this restriction, the remote UE only uses a single connectivity for data transfer and reception. However, a drawback is that the remote UE is not able to utilize a second connection even if it is (e.g., on a physical layer) available. In case of high data volume, it would be very helpful if the remote UE in coverage can utilize both a direct connection and an indirect connection to achieve an aggregated data rate over both connections. In future 3GPP releases, it is expected that the remote UE would be able to operate in a similar mode as dual connectivity (DC) in a Uu interface to the gNB, which has been standardized for 3GPP NR since Release 15.

Summary

Accordingly, there is a need for a technique that enables a wireless device to apply a SL in DC.

As to a first method aspect, a method of establishing a dual connectivity (DC) of a wireless device is provided. The method comprises or initiates a step of establishing a first path of the DC. The first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The method further comprises or initiates a step of establishing a second path of the DC. The second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The method (e.g., according to the first method aspect) may be performed by the wireless device.

As to a second method aspect, a method of controlling a wireless device to establish a dual connectivity (DC) of the wireless device is provided. The method comprises or initiates a step of controlling the wireless device to establish a first path of the DC. The first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The method further comprises or initiates a step of controlling the wireless device to establish a second path of the DC. The second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The second method aspect may further comprise any feature and/or any step disclosed in the context of the first method aspect, or a feature and/or step corresponding thereto, e.g., a receiver counterpart to a transmitter feature or step.

The method (e.g., according to the second method aspect) may be performed by the at least one station. The at least one station may be a network node serving the wireless device.

The method (e.g., according to the second method aspect) may further comprise the features or steps of the first method aspect, or any feature or step corresponding thereto.

As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the first and/or second method aspect disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download, e.g., via the radio network, the RAN, the Internet and/or the host computer. Alternatively, or in addition, the method may be encoded in a Field-Programmable Gate Array (FPGA) and/or an Application-Specific Integrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language.

As to a first device aspect, a wireless device for establishing a dual connectivity (DC) of the wireless device is provided. The wireless device comprises memory operable to store instructions and processing circuitry operable to execute the instructions, such that the wireless device is operable to establish a first path of the DC. The first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The wireless device is further operable to establish a second path of the DC. The second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The wireless device (e.g., according to the first device aspect) may further be operable to perform any of the steps of the first method aspect.

As to a further first device aspect, a wireless device for establishing a dual connectivity (DC) of the wireless device is provided. The wireless device is configured to establish a first path of the DC. The first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device.

The wireless device is further configured to establish a second path of the DC. The second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The wireless device (e.g., according to the further first device aspect) may further be configured to perform any of the steps of the first method aspect.

As to a second device aspect, a network node for controlling a wireless device to establish a dual connectivity (DC) of the wireless device is provided. The network node comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the network node is operable to control the wireless device to establish a first path of the DC. The first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The network node is further operable to control the wireless device to establish a second path of the DC. The second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The network node (e.g., according to the second device aspect) may further comprise any feature or may be operable to perform any step of the second method aspect.

As to a further second device aspect, a network node for controlling a wireless device to establish a dual connectivity (DC) of the wireless device is provided. The network node is configured to control the wireless device to establish a first path of the DC. The first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The network node is further configured to control the wireless device to establish a second path of the DC. The second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The network node (e.g., according to the further second device aspect) may further comprise any feature or may be configured to perform any step of the second method aspect. The device aspects may be implemented alone or in combination with any one of the claims and/or any one of the detailed embodiments.

As to a still further aspect, a communication system including a host computer is provided. The host computer comprises a processing circuitry configured to provide user data, e.g., included in the first and/or second path of the DC. The host computer further comprises a communication interface configured to forward the data to a cellular network (e.g., the RAN and/or the base station) for transmission to a UE. A processing circuitry of the cellular network is configured to execute any one of the steps of the second method aspect. Alternatively or in addition, the UE comprises a radio interface and processing circuitry, which is configured to execute any one of the steps of the first method aspect.

The communication system may further include the UE. Alternatively, or in addition, the cellular network may further include one or more base stations configured for radio communication with the UE and/or to provide a data link between the UE and the host computer using the first and/or second method aspects.

The processing circuitry of the host computer may be configured to execute a host application, thereby providing the data and/or any host computer functionality described herein. Alternatively, or in addition, the processing circuitry of the UE may be configured to execute a client application associated with the host application.

Any one of the devices (e.g., the wireless devices or UEs), the network node (e.g., a base station), the communication system or any node or station for embodying the technique may further include any feature disclosed in the context of the method aspect, and vice versa. Particularly, any one of the units and modules disclosed herein may be configured to perform or initiate one or more of the steps of the method aspect.

Brief Description of the Drawings

Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein: Fig. 1 shows a schematic block diagram of an embodiment of a device for establishing a dual connectivity; Fig. 2 shows a schematic block diagram of an embodiment of a device for controlling establishing a dual connectivity;

Fig. 3 shows a flowchart for an embodiment of a method of establishing a dual connectivity, which method may be implementable by the device of Fig. 1;

Fig. 4 shows a flowchart for an embodiment of a method of controlling establishing a dual connectivity, which method may be implementable by the device of Fig. 2; Fig. 5 schematically illustrates a first example of a wireless network comprising embodiments of the devices of Figs. 1 and 2 for performing the methods of Figs. 3 and 4, respectively;

Fig. 6 schematically illustrates options for dual connectivity;

Fig. 7 schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Fig. 8 schematically illustrates first examples of radio bearers usable by embodiments of the devices of Figs. 1 and 2 for dual connectivity;

Fig. 9 schematically illustrates second examples of radio bearers usable by embodiments of the devices of Figs. 1 and 2 for dual connectivity; Fig. 10 schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Fig. 11 schematically illustrates an example of a sidelink relay; Fig. 12 schematically illustrates an example of a sidelink relay;

Fig. 13 schematically illustrates an example of a sidelink relay; Fig. 14 schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Fig. 15 schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Fig. 16 schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Figs. 17A and 17B schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Fig. 18 schematically illustrates embodiments of the devices of Figs. 1 and 2 using dual connectivity;

Fig. 19 shows a schematic block diagram of a wireless device embodying the device of Fig. 1;

Fig. 20 shows a schematic block diagram of a network node embodying the device of Fig. 2;

Fig. 21 schematically illustrates an example telecommunication network connected via an intermediate network to a host computer;

Fig. 22 shows a generalized block diagram of a host computer communicating via a base station or radio device functioning as a gateway with a user equipment over a partially wireless connection; and

Figs. 23 and 24 show flowcharts for methods implemented in a communication system including a host computer, a base station or radio device functioning as a gateway and a user equipment.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for a New Radio (NR) or 5G implementation, it is readily apparent that the technique described herein may also be implemented for any other radio communication technique, including a Wireless Local Area Network (WLAN) implementation according to the standard family IEEE 802.11, 3GPP LTE (e.g., LTE-Advanced or a related radio access technique such as MulteFire), for Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy, Bluetooth Mesh Networking and Bluetooth broadcasting, for Z-Wave according to the Z-Wave Alliance or for ZigBee based on IEEE 802.15.4.

Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein.

Fig. 1 schematically illustrates a block diagram of an embodiment of a device for establishing a dual connectivity (DC) of a wireless device. The device is generically referred to by reference sign 100.

The device 100 comprises the modules 102 and 104 indicated in Fig. 1 that perform the respective steps of the first method and/or Fig. 3.

For example, a first path establishing module 102 establishes a first path of the DC, wherein the first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. A second path establishing module 104 establishes a second path of the DC, wherein the second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

Any of the modules of the device 100 may be implemented by units configured to provide the corresponding functionality.

The device 100 may also be referred to as, or may be embodied by, the wireless device 100 (or briefly: UE 100). The UE 100 and the at least one station may be in direct radio communication. The at least one station may be embodied by the device 220.

Fig. 2 schematically illustrates a block diagram of an embodiment of a device for controlling a wireless device establishing a DC. The device is generically referred to by reference sign 200.

The device 200 comprises the modules 202 and 204 indicated in Fig. 2 that perform the respective steps of the second method and/or Fig. 4.

For example, a first path controlling module 202 controls the wireless device to establish a first path of the DC, wherein the first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. A second path controlling module 204 controls the wireless device to establish a second path of the DC, wherein the second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

Any of the modules of the device 200 may be implemented by units configured to provide the corresponding functionality.

The device 200 may also be referred to as, or may be embodied by, the at least one station (or briefly: network node). The network node 220 and the wireless device 100 may be in direct radio communication. The wireless device may be embodied by the device 100.

Fig. 3 shows an example flowchart for a method 300 of performing the first method aspect. The method 300 comprises a step 302 of establishing a first path of the DC, wherein the first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The method 300 further comprises a step 304 of establishing a second path of the DC, wherein the second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The method 300 may be performed by the device 100. For example, the modules 102 and 104 may perform the steps 302 and 304, respectively.

Fig. 4 shows an example flowchart for a method 400 of performing the second method aspect, e.g., according to embodiment 36 in the list of embodiments.

The method 400 comprises a step 402 of controlling the wireless device to establish a first path of the DC, wherein the first path of the DC is wirelessly connected from the wireless device towards a first peer wireless device using a first sidelink (SL) between the wireless device and the first peer wireless device. The method 400 comprises a step 404 of controlling the wireless device to establish a second path of the DC, wherein the second path of the DC is wirelessly connected from the wireless device towards at least one station other than the first peer wireless device.

The method 400 may be performed by the device 220. For example, the modules 202 and 204 may perform the steps 402 and 404, respectively.

In any aspect, the technique may use an uplink (UL) and/or downlink (DL) in the second path and/or direct communications between radio devices, e.g., device-to- device (D2D) communications or sidelink (SL) communications in the first path.

Each of the wireless device 100 and network node 220 may be a radio device and a base station, respectively. Herein, any wireless device (e.g., radio device) may be a mobile or portable station and/or any radio device wirelessly connectable to a base station or RAN, or to another radio device. For example, the radio device may be a user equipment (UE), a device for machine-type communication (MTC) or a device for (e.g., narrowband) Internet of Things (loT). Two or more radio devices may be configured to wirelessly connect to each other, e.g., in an ad hoc radio network or via a 3GPP SL connection. Furthermore, any base station may be a station providing radio access, may be part of a radio access network (RAN) and/or may be a node connected to the RAN for controlling the radio access. For example, the base station may be an access point, for example a Wi-Fi access point.

The DC may comprise the first path and the second path that is different from the first path. The first path and the second path may be disjoint, e.g., except for its ends including the wireless device.

The first path of the DC may be wirelessly connected directly towards the first peer wireless device using the first SL. That is, the first path of the DC may be directly connected towards the first peer wireless device using the wireless first SL.

The second path of the DC may be wirelessly connected directly towards the at least one station. That is, the second path of the DC may be directly connected towards the at least one station using a wireless interface other than the first SL, e.g. a wireless second SL or an uplink or a downlink or a Uu interface.

Herein, wirelessly connected may refer to a propagation of electromagnetic waves, e.g., including at least one of reflection, refraction, diffraction, and attenuation. Directly connected may refer to the propagation of electromagnetic waves without intermediate retransmission, relaying, or amplification.

Herein, the words "at least one" may refer to the alternative "one" or the alternative "more than one". E.g., the at least one station may be one station.

The wireless connection of the first path (e.g., the first SL) may comprise a radio connection (or communication, e.g., a radio link) or a free-space optical connection (or communication, e.g., an optical link). Alternatively or in addition, the wireless connection of the second path (e.g., between the wireless device and the at least one station) may comprise a radio connection (or communication, e.g., a radio link) or a free-space optical connection (or communication, e.g., an optical link).

The first SL may comprise a PC5 interface between the wireless device and the first peer wireless device. The at least one station may be the destination of the second path. Alternatively or in addition, the wireless device may be the destination of the first path.

A master node may terminate the first path. A secondary node may terminate the second path. Alternatively or in addition, a master node may terminate the second path. A secondary node may terminate the first path.

The wireless device may have the first path and the second path as two active links at the same time, e.g., one over the Uu interface and another one over the PC5 interface.

Herein, the wireless device may also be referred to as a source node. The wireless device may be part of a communication chain, in which case the wireless device may also act as a receiving node that forwards a received message using the DC.

Herein, the paths may also be referred to as connections. The established paths of the DC may be collectively referred to as the DC connection.

Multi-connectivity may be an example of the DC.

Herein, node or station may be an umbrella term for a wireless device (e.g., a user equipment) and a network node (e.g., a base station).

The wireless device may be a radio device, e.g., a user equipment (UE).

The at least one station and/or the at least one further station may be a network node, e.g., a base station, e.g., a next generation node B (gNodeB or gNB).

The wireless access network may be a radio access network (RAN).

The at least one station (e.g., according to the first method aspect) may be or may comprise one or more network nodes or one or more cell groups. A wireless access network may comprise the at least one station.

The wireless access network may be a radio access network (RAN). The at least one station (e.g., according to the first method aspect) may be or may comprise at least one of a master node (MN) of the DC, a master cell group (MCG) of the DC, a secondary node (SN) of the DC, and a secondary cell group (SCG) of the DC.

The second path of the DC (e.g., according to the first method aspect) may be wirelessly connected towards the at least one station using at least one of an uplink, a downlink, and a Uu interface between the wireless device and the at least one station.

The second path of the DC may be wirelessly connected directly towards the (at least one) station using the Uu interface. That is, the second path of the DC may be directly connected towards the (at least one) station using the wirelessly Uu interface.

The first peer wireless device (e.g., according to the first method aspect) may be a relay wireless device relaying the first path of the DC from the wireless device to the at least one station and/or to the wireless access network comprising the at least one station.

The first path may also be referred to as an indirect path. The second path may also be referred to as a direct path.

The at least one station may be the destination of the second path. Alternatively or in addition, the at least one station and/or to the wireless access network comprising the at least one station may be the destination of the first path.

The second path (e.g., according to the first method aspect) may be wirelessly connected towards one station. The first path of the DC may be relayed to the one station. The one station may be or may comprise both a master node (MN) and a secondary node (SN) of the DC of the wireless device.

The one station may be the destination of the second path. Alternatively or in addition, the one station may be the destination of the first path.

The at least one station may be at least one network node of a wireless access network. The first peer wireless device may be a relay wireless device relaying the first path of the DC from the wireless device to at least one further network node of the wireless access network comprising the at least one network node.

The at least one further station may be different from the at least one station.

The at least one station may be the destination of the second path. Alternatively or in addition, the at least one further station may be the destination of the first path.

The at least one station may be one station. The at least one further station may be one further station other than the one station.

The at least one further network node (e.g., according to the first method aspect) may be or may comprise a MN of the DC of the wireless device. The at least one a station may be or may comprise at least one SN of the DC of the wireless device.

The at least one further network node (e.g., according to the first method aspect) may be or may comprise at least one SN of the DC of the wireless device. The at least one a station may be or may comprise a MN of the DC of the wireless device.

In any aspect, the wireless device may have the second path towards the network node (e.g., a gNB) of the wireless access network (e.g., over Uu) and the first path (i.e., another path) towards the first peer wireless device (e.g., over PC5).

If the destination of traffic (e.g., one or more data packets) is only the network node and/or the further network node, the first path may be a relay path as the traffic transmitted by the wireless device as the source (e.g., over PC5) in the first path (i.e., to the first peer wireless device) is relayed to the network node and/or the further network node (e.g., by the peer wireless device).

The at least one station (e.g., according to the first method aspect) may be or may comprise a second peer wireless device.

The second peer wireless device may be the destination of the second path. Alternatively or in addition, the first peer wireless device may be the destination of the first path. If the destination of the traffic is not only the network node (e.g., a gNB) and/or the further network node (e.g., a further gNB), the first path (e.g., over PC5) may be considered as sidelink standalone, e.g., as the traffic transmitted by the wireless device in the first path (i.e., to the first peer wireless device) does not need to be necessarily relayed to the network node or the further network node. One example of this scenario is a broadcast message (e.g., a public safety message).

The wireless device may want to reach the network node (and/or the further network node) and also one or more wireless devices including the first peer wireless device.

The second path of the DC (e.g., according to the first method aspect) may be wirelessly connected towards the second peer wireless device using at least one of a second SL and a PC5 interface between the wireless device and the second peer wireless device.

At least one of the wireless device, the first peer wireless device, and the at least one station may be wirelessly connected in a wireless ad hoc network, e.g., a mesh network.

The first peer wireless device (e.g., according to the first method aspect) may be a relay wireless device relaying the first path of the DC from the wireless device to the second peer wireless device. The second peer wireless device may be or may comprise both a master node (MN) and a secondary node (SN) of the DC of the wireless device.

The second peer wireless device may be the destination of the second path. Alternatively or in addition, the second peer wireless device may be the destination of the first path.

The first peer wireless device (e.g., according to the first method aspect) may be a relay wireless device relaying the first path of the DC from the wireless device to at least one further wireless device other than the second peer wireless device.

The second peer wireless device may be the destination of the second path. Alternatively or in addition, the at least one further wireless device may be the destination of the first path. The at least one further wireless device may be one further wireless device other than the second peer wireless device. The at least one further wireless device (e.g., according to the first method aspect) may be or may comprise a MN of the DC of the wireless device. The second peer wireless device may be or may comprise at least one SN of the DC of the wireless device.

The at least one further wireless device (e.g., according to the first method aspect) may be or may comprise a SN of the DC of the wireless device. The second peer wireless device may be or may comprise at least one MN of the DC of the wireless device.

A wireless ad hoc network may comprise at least one of the wireless device, the first peer wireless device and the at least one station.

In any aspect, the first path may be a master link of the DC, and/or the second path may be secondary link of the DC. Alternatively, the second path may be a master link of the DC, and/or the first path may be secondary link of the DC.

The wireless connection of the first path from the wireless device towards the first peer wireless device (e.g., according to the first method aspect) using the first SL between the wireless device and the first peer wireless device may be a master link of the DC of the wireless device. The wireless connection of the second path from the wireless device towards the at least one station may be a secondary link of the DC of the wireless device.

The wireless connection of the first path from the wireless device towards the first peer wireless device (e.g., according to the first method aspect) using the first SL between the wireless device and the first peer wireless device may be a secondary link of the DC of the wireless device. The wireless connection of the second path from the wireless device towards the at least one station may be a master link of the DC of the wireless device.

Both the first path and the second path (e.g., according to the first method aspect) may carry a radio bearer (RB). The RB may be anchored at an entity of an anchoring layer, optionally an anchoring layer of the MN or the SN. The anchoring layer (e.g., according to the first method aspect) may comprise at least one of a medium access control (MAC) layer; a radio link control (RLC) layer; a packet data convergence protocol (PDCP) layer; a radio resource control (RRC) layer; and a service data adaptation protocol (SDAP) layer.

The bearer (e.g., according to the first method aspect) may be at least one of split and duplicated at a split layer below the anchoring layer.

The split layer (e.g., according to the first method aspect) may comprise at least one of a physical (PHY) layer; a medium access control (MAC) layer; a radio link control (RLC) layer; a packet data convergence protocol (PDCP) layer; and a radio resource control (RRC) layer.

The split layer may be below the anchoring layer in a protocol stack of the MN and the SN.

The bearer (e.g., according to the first method aspect) may be a split bearer anchored at a PDCP entity associated with one or two Unacknowledged Mode (UM) RLC entities for the first path and associated with one or two UM RLC entities for the second path.

The bearer (e.g., according to the first method aspect) may be a split bearer anchored at a PDCP entity associated with one Acknowledged Mode (AM) RLC entities for the first path and associated with one AM RLC entities for the second path.

The bearer (e.g., according to the first method aspect) may be configured for duplication at a PDCP entity associated with N or IN UM RLC entities for the first path and associated with N or IN UM RLC entities for the second path.

The bearer (e.g., according to the first method aspect) may be configured for duplication at a PDCP entity associated with N AM RLC entities for the first path and associated with N AM RLC entities for the second path.

N may be a positive integer, e.g., in the range of 2 to 4. The radio bearer (RB) may be a signaling radio bearer (SRB), e.g., other than SRB0. The SRB may be defined as a RB that is only used for transmission of RRC and NAS messages. More specifically, at least one of the following three SRB types may be defined. A SRB0 may be used for transport of RRC messages associated with the common control logical channel. A SRB1 may be used for transport of RRC messages including piggybacked NAS messages and/or NAS messages prior to the establishment of SRB2 where all are associated with a dedicated control logical channel. A SRB2 may be used for transport of NAS messages using a dedicated control logical channel, has a lower priority than SRB1, and is always configured by E-UTRAN after security activation.

The first path (e.g., according to the first method aspect) may carry a first non-split RB. Alternatively or in addition, the second path (e.g., according to the first method aspect) may carry a second non-split RB.

A first non-split RB mapped to the first path may be associated with a first PDCP entity and one or two first UM RLC entities or one first AM RLC entity. Alternatively or in addition, a second non-split RB mapped to the second path may be associated with a second PDCP entity and one or two second UM RLC entities or one second AM RLC entity.

The method (e.g., according to the first method aspect) may further comprise or initiate a step of transmitting data packets from the wireless device to the first peer wireless device in the first path of the DC.

The first SL may be a standalone SL. Alternatively or in addition, the first peer wireless device may be out of coverage.

The method (e.g., according to the first method aspect) may further comprise or initiate the step of transmitting data packets from the wireless device to the at least one station in the second path of the DC.

The first SL may be a SL relay. Alternatively or in addition, the first peer wireless device may be a relay wireless device.

The DC (e.g., according to the first method aspect) may be a multi-connectivity comprising more than two paths. The step of establishing the first path may further comprise establishing a third path of the DC. The third path of the DC may be wirelessly connected from the wireless device towards a third peer wireless device using a third SL between the wireless device and the first peer wireless device. The step of establishing the second path may further comprise establishing a fourth path of the DC. The fourth path of the DC may be wirelessly connected from the wireless device towards at least one station other than the first and third peer wireless device.

Herein, reference to a third object (e.g., a third SL) may imply or does not imply the presence of a second object, etc. Reference to a first object (e.g., a first path) etc. may imply or does not imply a temporal order of the objects.

The wireless device (e.g., according to the first method aspect) may establish as many paths, or wireless connections of the paths, of the multi-connectivity as supported by the wireless device.

At least one or each of the establishing steps may be performed according to at least one of the following triggering conditions:

- according to a triggering condition that depends on, or is controlled, by at least one of a service using the DC, an application using the DC, and a traffic transmitted using the DC;

- in predefined or configured geographical location;

- when a volume of data pending for transmission at the wireless device is greater than a predefined or configured threshold value;

- when a volume of data pending for transmission at the wireless device is greater than a predefined or configured first threshold value and less than a predefined or configured second threshold value;

- when a signal strength of one or each of the at least one network node at the Uu interface is less than a predefined or configured threshold value;

- when a signal strength of one or each of the at least one network node at the Uu interface is greater than a predefined or configured first threshold value and less than a predefined or configured second threshold value;

- upon an indication and/or configuration from the at least one network node or the wireless access network;

- upon an indication and/or configuration from the peer wireless device; upon an indication from an upper layer of a communication protocol stack at the wireless device; and - upon an indication received from a host computer of an application and/or service used at the wireless device.

Performing the establishing steps may also be referred to as applying the DC.

The wireless device 100 (e.g., according to the first method aspect) may select whether to use one, a portion, or all of the established paths, the first path or the second path, optionally every time that a data packet for transmission becomes available at the wireless device.

The method 300 (e.g., according to the first method aspect) may be performed by the wireless device.

The method 400 may further comprise any feature and/or any step disclosed in the context of the method 300, or a feature and/or step corresponding thereto, e.g., a receiver counterpart to a transmitter feature or step.

The at least one or each of the steps (e.g., according to the second method aspect) of controlling the wireless device may use at least one of radio resource control (RRC) signaling; a medium access control (MAC) control entity (CE); and a signaling of a physical layer, optionally on a physical random access channel (PRACH) and/or a physical uplink control channel (PUCCH) and/or physical downlink control channel (PDCCH).

The method 400 (e.g., according to the second method aspect) may be performed by the at least one station.

The at least one station may be a network node serving the wireless device.

The method 400 (e.g., according to the second method aspect) may further comprise the features or steps of the method 300, or any feature or step corresponding thereto.

The network node 200 (e.g., according to the further second device aspect) may further comprise any feature or may be configured to perform any step of the method 400. Embodiments of the technique can enable multi-path links (i.e., the paths) in case of DC (e.g., multi-connectivity) scenarios. Same or further embodiments may comprise use at least one sidelink (e.g., a wireless device-to-device, or D2D, communication) for dual connectivity, e.g., for a wireless transmission on multiple paths and/or over multiple hops. Same or further embodiments may use a radio access technology for the paths according to 3GPP New Radio (NR) and/or 3GPP Long Term Evolution (LTE).

The technique may be applied in the context of 3GPP NR. Alternatively or in addition, the technique may be implemented in accordance with, or by extending, a 3GPP specification, e.g., for 3GPP release 16 or 17, e.g., the 3GPP document TS 38.331, version 16.5.0; and/or the 3GPP document TS 38.323, version 16.4; and/or the 3GPP document TS 38.300, version 16.6.0.

Alternatively or in addition, the technique may be implemented for 3GPP LTE or 3GPP NR according to a modification of the 3GPP document TS 23.303, version 16.0.0 or for 3GPP NR according to a modification of the 3GPP document TS 33.303, version 16.0.0.

In any radio access technology (RAT), the technique may implement DC using a relay over the SL. The SL may be implemented using proximity services (ProSe), e.g. according to a 3GPP specification.

Any wireless device may be a radio device, e.g., a user equipment (UE), e.g., according to a 3GPP specification. The relay wireless device may also be referred to as a relay UE (or briefly: relay). Alternatively or in addition, a remote wireless device or remote radio device may also be referred to as a remote UE.

The wireless device, the first peer wireless device, the second peer wireless device, the at least one network node, the at least on further network node, and/or the wireless access network (e.g., RAN) may form, or may be part of, a wireless (e.g., radio) network, e.g., according to the Third Generation Partnership Project (3GPP) or according to the standard family IEEE 802.11 (Wi-Fi). The first method aspect, the second method aspect may be performed by one or more embodiments of the wireless device and the RAN (e.g., a serving network node or a base station of the wireless device), respectively. The RAN may comprise one or more network node (e.g., base stations), e.g., performing the second method aspect. Alternatively or in addition, the radio network may be a vehicular, ad hoc and/or mesh network comprising two or more wireless device (e.g., radio devices), e.g., acting the wireless device and/or the first peer wireless device and/or the second peer wireless device and/or a further wireless device.

Any of the wireless devices (e.g., radio devices) may be a 3GPP user equipment (UE) or a Wi-Fi station (STA). Any wireless device may be a mobile or portable station, a device for machine-type communication (MTC), a device for narrowband Internet of Things (NB-loT) or a combination thereof. Examples for the UE and the mobile station include a mobile phone, a tablet computer and a self-driving vehicle. Examples for the portable station include a laptop computer and a television set. Examples for the MTC device or the NB-loT device include robots, sensors and/or actuators, e.g., in manufacturing, automotive communication and home automation. The MTC device or the NB-loT device may be implemented in a manufacturing plant, household appliances and consumer electronics.

Whenever referring to the RAN, the RAN may be implemented by one or more network node (e.g., base stations).

The wireless device may be wirelessly connected or connectable (e.g., according to a radio resource control, RRC, state or active mode) with the relay wireless device and/or at least one base station of the RAN. The relay radio device may be wirelessly connected or connectable (e.g., according to a radio resource control, RRC, state or active mode) with at least one base station of the RAN and/or the further remote radio device. Furthermore, the relay radio device may be wirelessly connected or connectable (e.g., according to 3GPP ProSe) with the remote radio device.

Any network node (e.g., base station) may encompass a station that is configured to provide wireless (e.g., radio access) to any of the wireless device (e.g., radio devices). Any of the network nodes may also be referred to or implemented by a base station, cell, a transmission and reception point (TRP), a radio access node or access point (AP). The base station and/or the relay radio device may provide a data link to a host computer providing the user data to the remote radio device or gathering user data from the remote radio device. Examples for the network nodes (e.g., base stations) may include a 3G base station or Node B, 4G base station or eNodeB, a 5G base station or gNodeB, a Wi-Fi AP and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave).

The RAN may be implemented according to the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE) and/or 3GPP New Radio (NR).

Any aspect of the technique may be implemented on a Physical Layer (PHY), a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a packet data convergence protocol (PDCP) layer, and/or a Radio Resource Control (RRC) layer of a protocol stack for the radio communication.

Herein, referring to a protocol of a layer may also refer to the corresponding layer in the protocol stack. Vice versa, referring to a layer of the protocol stack may also refer to the corresponding protocol of the layer. Any protocol may be implemented by a corresponding method.

Herein, whenever referring to noise or a signal-to-noise ratio (SNR), a corresponding step, feature or effect is also disclosed for noise and/or interference or a signal-to-interference-and-noise ratio (SINR).

Fig. 5 schematically illustrates a wireless access network or an ad hoc network comprising an embodiments of the first peer wireless device 210 in coverage or out of coverage of. a cell 304 of an embodiment of a network node 220.

Any of the embodiments may implement 3GPP Dual Connectivity (DC) according to any one of the options describe below.

There are different ways to deploy 5G network 500 with or without interworking with LTE (also referred to as E-UTRA) and evolved packet core (EPC), as depicted in Figure 1. In principle, NR and LTE can be deployed without any interworking, denoted by NR stand-alone (SA) operation, that is gNB in NR can be connected to 5G core network (5GC) and eNB can be connected to EPC with no interconnection between the two (Option 1 and Option 2 in the figure). On the other hand, the first supported version of NR is the so-called EN-DC (E-UTRAN-NR Dual Connectivity), illustrated by Option 3. In such a deployment, dual connectivity between NR and LTE is applied with LTE as the master and NR as the secondary node. The RAN node (gNB) supporting NR, may not have a control plane connection to core network (EPC), instead it relies on the LTE as master node (MeNB). This is also called as "Non-standalone NR". Notice that in this case the functionality of an NR cell is limited and would be used for connected mode UEs as a booster and/or diversity leg, but an RRCJDLE UE cannot camp on these NR cells.

With introduction of 5GC, other options may be also valid. As mentioned above, option 2 supports stand-alone NR deployment where gNB is connected to 5GC. Similarly, LTE can also be connected to 5GC using option 5 (also known as eLTE, E-UTRA/5GC, or LTE/5GC and the node can be referred to as an ng-eNB). In these cases, both NR and LTE are seen as part of the NG-RAN (and both the ng-eNB and the gNB can be referred to as NG-RAN nodes). It is worth noting that, Option 4 and option 7 are other variants of dual connectivity between LTE and NR which will be standardized as part of NG-RAN connected to 5GC, denoted by MR-DC (Multi-Radio Dual Connectivity).

Under the MR-DC umbrella, the technique may implement at least one of:

EN-DC (Option 3): LTE is the master node and NR is the secondary (EPC CN employed).

NE-DC (Option 4): NR is the master node and LTE is the secondary (5GCN employed).

NGEN-DC (Option 7): LTE is the master node and NR is the secondary (5GCN employed).

NR-DC (variant of Option 2): Dual connectivity where both the master and secondary are NR (5GCN employed).

Fig. 6 schematically illustrates LTE and NR interworking options, which may be implemented by the technique.

As migration for these options may differ from different operators, it is possible to have deployments with multiple options in parallel in the same network e.g. there could be eNB base station supporting option 3, 5 and 7 in the same network as NR base station supporting 2 and 4. In combination with dual connectivity solutions between LTE and NR it is also possible to support CA (Carrier Aggregation) in each cell group (i.e. MCG and SCG) and dual connectivity between nodes on same RAT (e.g. NR-NR DC). For the LTE cells, a consequence of these different deployments is the co-existence of LTE cells associated to eNBs connected to EPC, 5GC or both EPC/5GC.

LTE DC and multi-RAT DC (MR-DC) are designed differently when it comes to which nodes control what. Basically, there are two options:

1. Centralized solution (like LTE-DC),

2. Decentralized solution (like MR-DC, i.e. (NG)EN-DC, NE-DC and NR-DC).

Fig. 7 shows the schematic control plane architecture looks like for LTE DC and EN-DC. Note that the EN-DC architecture also applies to other MR-DC options. The main difference here is that in EN-DC, the SN has a separate RRC entity (NR RRC). This means that the SN can control the UE also; sometimes without the knowledge of the MN but often the SN need to coordinate with the MN. In LTE- DC, the RRC decisions are always coming from the MN (MN to UE). Note however, the SN still decides the configuration of the SN, since it is only the SN itself that has knowledge of what kind of resources, capabilities etc. it has.

Any embodiment may implement the Control Plane architecture for Dual Connectivity 1500 in LTE DC and EN-DC according to Fig. 7

EN-DC, may differ e.g., the compared to LTE DC by the introduction of split bearer 800 from the SN (known as SCG split bearer), the introduction of split bearer 800 for RRC, and/or the introduction of a direct RRC from the SN (also referred to as SCG SRB).

Figs. 8 and 9 show the UP and Control Plane (CP) architectures for EN-DC.

In Fig. 8, the network side protocol termination options for MCG, SCG and split bearers in MR-DC with EPC (EN-DC) are schematically illustrated.

In Fig. 9, network architecture for control plane in EN-DC are schematically illustrated.

The SN is sometimes referred to as SgNB (where gNB is an NR base station), and the MN as MeNB in case the LTE is the master node and NR is the secondary node. In the other case where NR is the master and LTE is the secondary node, the corresponding terms are SeNB and MgNB.

Split RRC messages are mainly used for creating diversity, and the sender can decide to either choose one of the links for scheduling the RRC messages, or it can duplicate the message over both links. In the downlink, the path switching between the MCG or SCG legs or duplication on both is left to network implementation. On the other hand, for the UL, the network configures the UE to use the MCG, SCG or both legs. The terms "leg", "path" and "RLC bearer" are used interchangeably throughout this document.

Embodiments may implement 3GPP work on sidelink.

3GPP specified the LTE D2D (device-to-device) technology, also known as ProSe (Proximity Services) in the Release 12 and 13 of LTE. Later in Rel. 14 and 15, LTE V2X related enhancements targeting the specific characteristics of vehicular communications were specified. 3GPP has started a new work item (Wl) in August 2018 within the scope of Rel. 16 to develop a new radio (NR) version of V2X communications. The NR V2X mainly targets advanced V2X services, which can be categorized into four use case groups: vehicles platooning, extended sensors, advanced driving and remote driving. The advanced V2X services would require enhanced NR system and new NR sidelink framework to meet the stringent requirements in terms of latency and reliability. NR V2X system also expects to have higher system capacity and better coverage and to allow for an easy extension to support the future development of further advanced V2X services and other services.

Given the targeted services by NR V2X, it is commonly recognized that groupcast/multicast and unicast transmissions are desired, in which the intended receiver of a message consists of only a subset of the vehicles in proximity to the transmitter (groupcast) or of a single vehicle (unicast). For example, in the platooning service there are certain messages that are only of interest of the members of the platoon, making the members of the platoon a natural groupcast. In another example, the see-through use case most likely involves only a pair of vehicles, for which unicast transmissions naturally fit. Therefore, NR sidelink can support broadcast (as in LTE), groupcast and unicast transmissions. Furthermore, NR sidelink is designed in such a way that its operation is possible with and without network coverage and with varying degrees of interaction between the UEs (user equipment) and the NW (network), including support for standalone, network-less operation.

In 3GPP, Release 17 discussions are being taken place and NSPS is considered to be one of the use cases which can benefit from the already developed NR sidelink. Therefore, it is most likely that 3GPP will specify enhancements related to NSPS use case taking NR Release 16 sidelink as a baseline.

Any embodiment may serve National Security and Public Safety (NSPS) use case and requirements.

In the traditional specific NSPS communication systems such as Terrestrial Trunked Radio (TETRA), the data rates were in the order of a few kbit/s at most, which do not provide support for the foreseen NSPS use case scenarios. Moreover, the NSPS use case requires an enhanced coverage and high reliability for its communications. Therefore, NSPS is a particularly interesting case for NR since it can provide the required robustness in the communications and the capability to communicate even in the cases where a fixed infrastructure is not installed.

Fig. 10 schematically illustrates a scenario for NSPS including in and out-of- coverage users.

Some of the scenarios where NSPS communication has potentially no support from the infrastructure are such as tunnels, inside some buildings or in emergency situations where the infrastructure is destroyed or non-operative. Even though in some of these cases, cellular coverage can be provided using some sort of mobile stations, i.e., trucks with a portable base station installed as shown in Fig. 10, the implementation of sidelink communications can be beneficial in NSPS. Among the requirements for NSPS, one main topic is the group communication for NSPS in cases such as, a group of workers in a building. The scenarios which are considered for NSPS include in-coverage scenarios where network (eNB/gNB) is available and out-of-coverage scenarios where there is no infrastructure. For the out-of-coverage scenario the addition of sidelink for synchronization and communication among the users is foreseen, however, the inclusion of multi-hop sidelink has not been realized in legacy communication systems.

Any embodiment may use PDCP for packet duplication, e.g., in a NR system.

PDCP layer can provide routing and packet duplication. There is one PDCP entity per radio bearer configured for a device. Moreover, dual connectivity is another feature that is enabled in NR systems due to the PDCP layer.

Packet duplication in PDCP can be used for additional diversity. Packets can be duplicated and transmitted on multiple cells, increasing the likelihood of at least one copy being correctly received. This can be useful for services requiring very high reliability. At the receiving end, the PDCP layer duplicate removal functionality removes any duplicates. This results in path selection diversity.

Dual connectivity is another area where the PDCP layer plays an important role.

In dual connectivity, a device is connected to two cells, or in general, two cell groups, the Master Cell Group (MCG) and the Secondary Cell Group (SCG). The two cell groups can be handled by different gNBs. A radio bearer is typically handled by one of the cell groups, but there is also the possibility for split bearers, in which case one radio bearer is handled by both cell groups. In this case the PDCP is in charge of distributing the data between the MCG and the SCG.

Any embodiment may implement a Radio-Link Control, e.g., in a NR system.

Radio-Link Control (RLC) is responsible for segmentation and retransmission handling. The RLC provides services to the PDCP in the form of RLC channels. There is one RLC entity per RLC channel (and hence per radio bearer) configured for a device. Compared to LTE, the NR RLC does not support in-sequence delivery of data to higher protocol layers, a change motivated by the reduced delays. The RLC protocol is responsible for segmentation of RLC SDUs from the PDCP into suitably sized RLC PDUs. It also handles retransmission of erroneously received PDUs, as well as removal of duplicate PDUs.

Depending on the type of service, the RLC can be configured in one of three modes— transparent mode, unacknowledged mode, and acknowledged mode — to perform some or all these functions. Transparent mode adds no headers to the transmissions. Unacknowledged mode supports segmentation and duplicate detection, while acknowledged mode in addition to the latter supports retransmission of erroneous packets.

One major difference compared to LTE is that the RLC does not ensure in sequence delivery of SDUs to upper layers. Removing in-sequence delivery from the RLC reduces the overall latency as later packets do not have to wait for retransmission of an earlier missing packet before being delivered to higher layers but can be forwarded immediately. Another difference is the removal of concatenation from the RLC protocol to allow RLC PDUs to be assembled in advance, prior to receiving the uplink scheduling grant. This also helps reduce the overall latency.

Any embodiment using a relay at the first peer wireless device 210 may implement a Layer 2 (L2) UE-to-Network relay.

In the TR 23.752 clause 6.7, the layer-2 based UE-to-Network relay is described. The protocol architecture supporting a L2 UE-to-Network Relay UE is provided. The L2 UE-to-Network Relay UE provides forwarding functionality that can relay any type of traffic over the PC5 link.

The L2 UE-to-Network Relay UE provides the functionality to support connectivity to the 5GS for Remote UEs. A UE is considered to be a Remote UE if it has successfully established a PC5 link to the L2 UE-to-Network Relay UE. A Remote UE can be located within NG-RAN coverage or outside of NG-RAN coverage.

Fig. 11 illustrates the protocol stack for the user plane transport, related to a PDU Session, including a Layer 2 UE-to-Network Relay UE. The PDU layer corresponds to the PDU carried between the Remote UE and the Data Network (DN) over the PDU session. The PDU layer corresponds to the PDU carried between the Remote UE and the Data Network (DN) over the PDU session. It is important to note that the two endpoints of the PDCP link are the Remote UE and the gNB. The relay function is performed below PDCP. This means that data security is ensured between the Remote UE and the gNB without exposing raw data at the UE-to- Network Relay UE. Fig. 11 schematically illustrates a User Plane Stack for L2 UE-to-Network Relay UE in TR 23.752.

The adaptation rely layer within the UE-to-Network Relay UE can differentiate between signaling radio bearers (SRBs) and data radio bearers (DRBs) for a particular Remote UE. The adaption relay layer is also responsible for mapping PC5 traffic to one or more DRBs of the Uu. The definition of the adaptation relay layer is under the responsibility of RAN WG2.

Fig. 12 schematically illustrates the protocol stack of the NAS connection for the Remote UE to the NAS-MM and NAS-SM components. The NAS messages are transparently transferred between the Remote UE and 5G-AN over the Layer 2 UE-to-Network Relay UE using at least one of:

- PDCP end-to-end connection where the role of the UE-to-Network Relay UE is to relay the PDUs over the signaling radio bear without any modifications.

- N2 connection between the 5G-AN and AMF over N2.

- Nil connection AMF and SMF over Nil.

The role of the UE-to-Network Relay UE is to relay the PDUs from the signaling radio bearer without any modifications.

Fig. 12 schematically illustrates a Control Plane for L2 UE-to-Network Relay UE in TR 23.752

Alternatively or in addition, any embodiment using a relay at the first peer wireless device 210 may implement Layer 3 (L3) UE-to-Network relay.

E.g., in the 3GPP document TR 23.752, clause 6.6, the layer-3 based UE-to- Network relay is described.

The ProSe 5G UE-to-Network Relay entity provides the functionality to support connectivity to the network for Remote UEs (see Fig. 13). It can be used for both public safety services and commercial services (e.g. interactive service).

A UE is considered to be a Remote UE for a certain ProSe UE-to-Network relay if it has successfully established a PC5 link to this ProSe 5G UE-to-Network Relay. A Remote UE can be located within NG-RAN coverage or outside of NG-RAN coverage.

Fig. 13 schematically illustrates an architecture model using a ProSe 5G UE-to- Network Relay according to the 3GPP document TR 23.752.

The ProSe 5G UE-to-Network Relay shall relay unicast traffic (UL and DL) between the Remote UE and the network. The ProSe UE-to-Network Relay shall provide generic function that can relay any IP traffic.

One-to-one Direct Communication is used between Remote UEs and ProSe 5G UE-to-Network Relays for unicast traffic as specified in solutions for Key Issue #2 in the TR 23.752.

The protocol stack for Layer-3 UE-to-Network Relays is shown in Figure 5.

Fig. 14 schematically illustrates a protocol stack for ProSe 5G UE-to-Network Relay according to the 3GPP document TR 23.752.

Hop-by-hop security is supported in the PC5 link and Uu link. If there are requirements beyond hop-by-hop security for protection of Remote UE's traffic, security over IP layer needs to be applied.

The technique may enable dual connectivity (e.g., multi connectivity in some cases) between sidelink and Uu link, and also between only sidelink links.

Alternatively or in addition to the embodiments in the list of embodiments, the UE (as the wireless device 100) may have at least one of the following features.

A UE with sidelink capabilities (e.g., transmitting on a standalone sidelink and/or having access to a sidelink relay or acting as a sidelink relay) establishes a dual connectivity connection with one path of the dual connectivity connected towards the network (via Uu) directly and the other path of the dual connectivity connected towards a peer UE (via PC5).

In such a case, the connection with the peer UE may be standalone sidelink (e.g., if the peer UE is the destination of the traffic) or may be sidelink relay (e.g., if the destination of the traffic is the gNB or another UE that is reachable via the peer UE).

A UE with sidelink capabilities (i.e., standalone sidelink and/or sidelink relay) establishes a dual connectivity connection with one path (i.e., the second path) of the dual connectivity connected towards a UE (e.g., a second peer UE and/or via PC5 link, e.g. labeled "1") and the other path (i.e., the first path) of the dual connectivity connected towards a peer UE (e.g., the first peer UE and/or via a PC5 link, e.g. labeled "2").

In such a case, the connection with the peer UEs may be standalone sidelink (e.g., if the peer UE is the destination of the traffic) or may be sidelink relay (e.g., if the destination of the traffic is the gNB or another UE that is reachable via the peer UE).

A UE with also sidelink capabilities (i.e., standalone sidelink and/or sidelink relay) establishes as many multiple connections as it supports (based on its capabilities). These multiple connections can be established towards one, or more peer UEs and one, or more, cell groups (e.g., MCG, SCG).

In any embodiment, the establishing steps 302 and 304 may be triggered upon an indication and/or configuration, e.g., from a peer UE 210.

In this disclosure, the term node is used which can be a network node or a UE.

Examples of network nodes are NodeB, base station (BS), multi-standard radio (MSR) radio node such as MSR BS, eNodeB, gNodeB. MeNB, SeNB, integrated access backhaul (IAB) node, network controller, radio network controller (RNC), base station controller (BSC), relay, donor node controlling relay, base transceiver station (BTS), Central Unit (e.g. in a gNB), Distributed Unit (e.g. in a gNB), Baseband Unit, Centralized Baseband, C-RAN, access point (AP), transmission points, transmission nodes, RRU, RRH, nodes in distributed antenna system (DAS), core network node (e.g. MSC, MME etc), O&M, OSS, SON, positioning node (e.g. E-SMLC), etc.

Another example of a node is user equipment (UE), which is a non-limiting term and refers to any type of wireless device communicating with a network node and/or with another UE in a cellular or mobile communication system. Examples of UE are target device, device to device (D2D) UE, vehicular to vehicular (V2V), machine type UE, MTC UE or UE capable of machine to machine (M2M) communication, PDA, Tablet, mobile terminals, smart phone, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles etc.

In some embodiments, generic terminology, "radio network node" or simply "network node (NW node)", is used. It can be any kind of network node which may comprise base station, radio base station, base transceiver station, base station controller, network controller, evolved Node B (eNB), Node B, gNodeB (gNB), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH), Central Unit (e.g. in a gNB), Distributed Unit (e.g. in a gNB), Baseband Unit, Centralized Baseband, C-RAN, access point (AP etc.

The term radio access technology, or RAT, may refer to any RAT e.g. UTRA, E- UTRA, narrow band internet of things (NB-loT), WiFi, Bluetooth, next generation RAT, New Radio (NR), 4G, 5G, etc. Any of the equipment denoted by the terminology node, network node or radio network node may be capable of supporting a single or multiple RATs.

Further, in the following we use the term "standalone sidelink" to describe a sidelink connection that is just between a UE (e.g., UE1) and a peer UE (i.e., UE2) and where the peer UE (i.e., UE2) is the destination of the traffic. On the contrary, we use the term "sidelink relay" to describe a sidelink connection between a source UE (i.e., the remote UE - RM UE) and a destination UE/gNB and which communication happens via a intermediate UE (i.e., the relay UE - RL UE).

Finally, in the following we the term "dual connectivity" we described a scenario where the UE has at least two active links at the same time. According to this, the dual connectivity may happen e.g. on the PDCP entity, or on the RLC entity. If the dual connectivity happens at the RLC entity, then the term "dual connectivity" can be exchanged without loss of meaning with "carrier aggregation". In the following, we use the term "dual connectivity" to describe both the "dual connectivity" at the PDCP entity and the "carrier aggregation" at the RLC entity. Further, we use the term "direct path" to stand for a direct connection from a remote UE to a gNB (e.g., via NR air interface) or a destination UE (e.g., via NR SL air interface) and we use the term "indirect path" to stand for an indirect connection between a remote UE and a gNB or another destination UE via an intermediate node also known as relay UE or relay gNB.

Alternatively or in addition to the list of embodiments, the wireless device 100 (described as the UE 100 herein) and/or any other node (e.g., the network node 220) may comprise the features of any one of the following detailed embodiments.

In a first detailed embodiment, a UE with sidelink capabilities (i.e., standalone sidelink and/or sidelink relay capabilities) e.g., UE1, establishes a dual connectivity connection in order to reach either a destination UE or a gNB. When establishing a dual connectivity, the UE setups two active links/paths at the same time according to the following options:

Option 1. UE1 establishes a dual connectivity connection with one path of the dual connectivity connected towards the network (via Uu) directly, i.e., direct path and the other path of the dual connectivity connected towards a peer UE (via PC5). In such a case, the destination of the dual connectivity path is a gNB. Further, in such a case, the connection with the peer UE (e.g., UE2) may be standalone sidelink (if the UE2 is also the destination of the traffic) or may be sidelink relay (e.g., if the destination of the traffic is the gNB), i.e., indirect path.

Fig. 15 schematically illustrates dual connectivity (DC) with PC5 and Uu.

The option 1 may be implemented according to two sub-options, e.g., depending on whether the destination gNBs of both paths 1510 and 1520 are the same or different.

Option la: UE1 connects to the same gNB (e.g., gNBl) via both one direct path and one indirect path (e.g., via UE2). In this option, gNBl serves both Master Node (MN) and Secondary Node (SN) for UE1.

Option lb: UE1 connects to the different gNBs via both paths. UE1 connects to gNBl via one direct path.

The UE1 connects to gNB2 via one indirect path (e.g., via UE2).

For UE1, one direction is the direct path, the other direction is the indirect path.

In both directions/links, one link is the master link, the other link is the secondary link.

In an example, the direct path 1520 is the master link, while the indirect path 1510 is the secondary link. Correspondingly, gNBl is the MN, while gNB2 is the SN.

In an example, the indirect path is the master link while the direct path is the secondary link. Correspondingly, gNB2 is the MN, while gNBl is the SN.

Regardless of Option la or Option lb, each radio bearer (RB) (e.g., except for SRB0 for the Uu interface) is associated with one PDCP entity.

For split bearers, each PDCP entity is associated with two UM RLC entities (for same direction), four UM RLC entities (two for each direction), or two AM RLC entities; In case of Option la, all RLC entities are configured to the same gNB, e.g., gNBl.

For RBs configured with PDCP duplication, each PDCP entity is associated with N UM RLC entities (for same direction), 2 x /V UM RLC entities ( N for each direction), or N AM RLC entities, wherein 2 <= N <= 4; In case of Option la, all RLC entities are configured to the same gNB, e.g., gNBl.

For a non-split bearer, each PDCP entity is associated with one UM RLC entity, two UM RLC entities (one for each direction), or one AM RLC entity.

UE1 may have one non-split bearer mapped onto the direct path the UE1 may also have one non-split bearer mapped onto the indirect path. Option 2. UE1 establishes a dual connectivity connection with one path 1520 of the dual connectivity 1500 connected towards a UE3 220 (e.g., the second peer UE and/or via "PC5 link 1") and the other path (i.e., the first path) of the dual connectivity connected towards a peer UE (via PC5 link 2). In such a case, the destination of the dual connectivity path is a destination UE. Further, in such a case, the connection with the first peer UE (e.g., UE2) may be standalone sidelink (e.g., if the UE2 is also the destination of the traffic) or may be sidelink relay (e.g., if the destination of the traffic is another UE, e.g., UE3 reachable by UE2).

Fig. 16 schematically illustrates a dual connectivity using SL (e.g., with PC5) only.

This option can be implemented according to two sub-options depending on whether the destination UEs of both paths 1510 and 1520 are the same or different.

Option 2a: UE1 connects to the same UE (e.g., UE3) via both one direct path and one indirect path (e.g., via UE2).

In this option, UE3 serves both Master Node (MN) and Secondary Node (SN) for UE1.

Option 2b: UE1 connects to the different UEs via both paths. UE1 connects to UE3 via one direct path. Meanwhile, UE1 connects to UE4 via one indirect path (e.g., via UE2). UE3 connects to UE4 via one direct connection.

In an example, the direct path 1520 is the master link, while the indirect path 1510 is the secondary link.

In an example, the indirect path 1510 is the master link while the direct path 1520 is the secondary link. Regardless of Option 2a or Option 2b, each RB (except for SRB0 for Uu interface) is associated with one PDCP entity.

For split bearers 800, each PDCP entity is associated with two UM RLC entities (for same direction), four UM RLC entities (two for each direction), or two AM RLC entities; In case of Option 2a, all RLC entities are configured to the same UE, e.g., UE3.

For RBs configured with PDCP duplication, each PDCP entity is associated with N UM RLC entities (for same direction), 2 x N UM RLC entities (N for each direction), or N AM RLC entities, where 2 <= N <= 4; In case of Option 2a, all RLC entities are configured to the same UE, e.g., UE3.

UE1 may have one non-split bearer mapped onto the direct path. The UE1 may also have one non-split bearer mapped onto the indirect path.

According to an Option 3, the UE 100 establishes as many multiple connections as it supports (based on its capabilities) and based on those that are available to be established. These multiple connections can be established towards one, or more peer UEs and one, or more, cell groups (e.g., MCG, SCG). Also, in this case the multi connection over PC5 may involve standalone sidelink and/or sidelink relay.

Multipath and multi-connectivity with PC5 and/or Uu when destination of the traffic is the network, e.g., as illustrated in Fig. 17A or, e.g., as illustrated in UE according Fig. 17B.

In a second detailed embodiment, the UE 100 may decide to establish the paths or connection of the dual connectivity 1500 (e.g., using PC5 and Uu for the first and second paths, respectively, or using only PC5 for the first and second paths) according to at least one of the following triggering conditions:

A first condition is according to a certain service and/or application and/or traffic. A second condition is a certain (e.g., predefined or configured) geographical location of the UE 100.

A third condition is when a data volume of the UE 100 (e.g., available or pending for transmission) is greater than a predefined or configured threshold. This condition may be triggered per service and/or application and/or traffic type and/or logical channel (LCH) and/or logical channel group (LCG). Alternatively or in addition, this condition may be triggered per a group of services and/or applications and/or traffic types. Alternatively or in addition, this condition may be triggered per UE 100.

A fourth condition is when the data volution of the UE 100 is greater than a configured first threshold and less than a configured second threshold. This condition may be triggered per service and/or application and/or traffic type and/or LCH and/or LCG. Alternatively, this condition may be triggered per a group of services and/or applications and/or traffic types. Alternatively, this condition may be triggered per UE.

A fifth condition is when a signal strength (e.g., a Uu signal strength or signal to noise ratio or a signal to interference and noise ratio) is less than a predefined or configured threshold. This condition may be applicable only for DC (e.g., multi connectivity) using PC5 and Uu.

A sixth condition is when the Uu signal strength is above a configured first threshold and below a configured second threshold (this is only applicable for dual/multi connectivity with PC5 and Uu).

A seventh condition is upon an indication and/or configuration from the network.

An eighth condition is upon an indication and/or configuration from the network node 220 and/or a peer UE 210.

A ninth condition is upon an indication from an upper layer (e.g., of the wireless device 100).

In a third embodiment, which may be combined with the first and/or second detailed embodiment, the UE 100 has a DC 150 (e.g., multi-connectivity) connection, i.e., has established at least the first and the second paths, means that the wireless device 100 has establish according to the steps 302 and 304 multiple radio bearer that are anchored and/or terminated at one entity of a protocol stack of the wireless device 100. This entity of the protocol stack may be the MAC, RLC, PDCP, RRC, or SDAP layer.

In the fourth detailed embodiment, which may be combined with the first, second and/or third detailed embodiment, whether to apply DC 1500 (e.g., multi connectivity) is decided hop-by-hop, e.g., by each receiving node functioning as an embodiment of the wireless device 100. For example, the source UE 100 decides whether to apply DC 1500 (e.g., multi-connectivity) only for those nodes (e.g., either gNB/eNB 220 or 222, or UEs 100) that are directly reachable by the source UE 100.

Once these nodes (e.g., gNB and/or eNB, or UEs) directly reachable by the source UE 100 receive source UE packets (i.e., data packets from the wireless device 100), they in turn decided to apply (or not) the DC 1500 (e.g., multi-connectivity) with the nodes (e.g., either gNB/eNB, or UEs) that are able to reach in a direct way.

Fig. 18 schematically illustrates a duplicated path as compared to a non- duplicated path.

For instance, in Fig. 18 the source UE 100 and the UEs decides to apply multi connectivity and sends the same packet to all the nodes that can be reached directly. On the contrary, UE1 decide to not apply dual or multi connectivity, e.g., even if it would have the possibility e.g., to reach directly the MCG or SCG.

In a fifth detailed embodiment, which may be combined with any one of the first to fourth detailed embodiments, upon setting up dual or multi connectivity, the UE may decide to apply duplication on all the available path or to use only a single (or some of the) path at a given time. E.g. as schematically illustrated in Fig. 17A or 17B, this means that even if the UE 100 had established three or four paths, it uses only one, a portion, or all of them at a given time.

In a sixth detailed embodiment, which may be combined with any one of the first to fifth detailed embodiments, the selection of one, a portion, or all of the available (e.g., established) paths 1510 or 1520 (e.g., according to one or more of the criteria described in the second detailed embodiment) is done by a semi static or dynamic approach. In the (e.g., same) static approach when the UE 100 has the first data packets, it selects to use one, a portion, or all of the available paths and the decision does not change over time (even if the traffic is not periodic but aperiodic).

With the dynamic approach the UE 100 selects dynamically whether to use one, a portion, or all of the available (e.g., established) paths 1510 or 1520, e.g., every time that new data packets come. This can be done for example by using multiple thresholds (one for each number of path to be activated) and the UE can compare e.g., a certain criteria (e.g., data volume, signal strength, expected throughput) with each of these thresholds e.g., if a criteria is above/below first threshold two paths activated, if criteria is above or below second threshold three paths activated, and so on. Further, is the dynamic approach is used, the UE may choose to "activate" or "deactivate" a certain path by use LI signaling (e.g., downlink control information, DCI or SL control information, SCI), MAC control element (MAC CE), or a control protocol data unit (control PDU) of an adaptation layer, or an RRC signaling (over Uu or PC5).

In a seventh detailed embodiment, which may be combined with any one of the first to sixth detailed embodiments, any one of the above embodiments is also applicable to a UE 100 with multi-connectivity (e.g., more than 2 connections, i.e., paths), wherein at least one connectivity 1510 (i.e., the first path) is based on a SL 1512.

In any embodiment, the destination nodes may comprise gNBs or UEs, which may be the same node or different nodes. The connections (i.e., the paths) may be grouped.

In an eighth detailed embodiment, which may be combined with any one of the first to seventh detailed embodiments, the technique (i.e., devices, nodes and methods and/or as described in any of the previous embodiments) the wireless device 100 should use is decided by the network node (e.g., gNB), e.g., serving the wireless device 100) and/or is communicated to the wireless device 100, e.g., via a dedicated RRC signaling and/or via system information (SI). As another alternative, which option the wireless device 100 (e.g., among the alternative indicated in any of the embodiments) should use may be decided by the wireless device 100 and/or is pre-configured (.g., hard-coded according to a technical specification).

In a ninth detailed embodiment, which may be combined with any one of the first to seventh detailed embodiments, for any of all above embodiments, the signaling alternatives described will include at least one of the below.

For signaling between UE and the gNB:

RRC signaling MAC CE

LI signaling on channels such as PRACH, PUCCH, PDCCH

For signaling between UEs:

RRC signaling (e.g., PC5-RRC)

PC5-S signaling Discovery signaling MAC CE

LI signaling on channels such as PSSCH, PSCCH, or PSFCH.

Herein, LI may refer to the PHY layer.

Fig. 19 shows a schematic block diagram for an embodiment of the device 100. The device 100 comprises processing circuitry, e.g., one or more processors 1904 for performing the method 300 and memory 1906 coupled to the processors 1904.

For example, the memory 1906 may be encoded with instructions that implement at least one of the modules 102 and 104.

The one or more processors 1904 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 1906, wireless device functionality. For example, the one or more processors 1904 may execute instructions stored in the memory 1906. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 100 being configured to perform the action.

As schematically illustrated in Fig. 19, the device 100 may be embodied by a wireless device 1900, e.g., functioning as a UE. The wireless device 1900 comprises a radio interface 1902 coupled to the device 100 for radio communication with one or more UEs and/or network nodes.

Fig. 20 shows a schematic block diagram for an embodiment of the device 210 or 220. The device 210 or 220 comprises processing circuitry, e.g., one or more processors 2004 for performing the method 400 and memory 2006 coupled to the processors 2004. For example, the memory 2006 may be encoded with instructions that implement at least one of the modules 202 and 204.

The one or more processors 2004 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 200, such as the memory 2006, network node functionality. For example, the one or more processors 2004 may execute instructions stored in the memory 2006. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 200 being configured to perform the action.

As schematically illustrated in Fig. 20, the device 210 or 220 may be embodied by a network node 2000, e.g., functioning as a base station. The network node 2000 comprises a radio interface 2002 coupled to the device 210 or 220 for radio communication with one or more UEs.

With reference to Fig. 21, in accordance with an embodiment, a communication system 2100 includes a telecommunication network 2110, such as a 3GPP-type cellular network, which comprises an access network 2111, such as a radio access network, and a core network 2114. The access network 2111 comprises a plurality of base stations 2112a, 2112b, 2112c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 2113a, 2113b, 2113c. Each base station 2112a, 2112b, 2112c is connectable to the core network 2114 over a wired or wireless connection 2115. A first user equipment (UE) 2191 located in coverage area 2113c is configured to wirelessly connect to, or be paged by, the corresponding base station 2112c. A second UE 2192 in coverage area 2113a is wirelessly connectable to the corresponding base station 2112a. While a plurality of UEs 2191, 2192 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 2112.

Any of the base stations 2112 and the UEs 2191, 2192 may embody the device 100.

The telecommunication network 2110 is itself connected to a host computer 2130, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 2130 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 2121, 2122 between the telecommunication network 2110 and the host computer 2130 may extend directly from the core network 2114 to the host computer 2130 or may go via an optional intermediate network 2120. The intermediate network 2120 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 2120, if any, may be a backbone network or the Internet; in particular, the intermediate network 2120 may comprise two or more sub-networks (not shown).

The communication system 2100 of Fig. 21 as a whole enables connectivity between one of the connected UEs 2191, 2192 and the host computer 2130. The connectivity may be described as an over-the-top (OTT) connection 2150. The host computer 2130 and the connected UEs 2191, 2192 are configured to communicate data and/or signaling via the OTT connection 2150, using the access network 2111, the core network 2114, any intermediate network 2120 and possible further infrastructure (not shown) as intermediaries. The OTT connection 2150 may be transparent in the sense that the participating communication devices through which the OTT connection 2150 passes are unaware of routing of uplink and downlink communications. For example, a base station 2112 need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 2130 to be forwarded (e.g., handed over) to a connected UE 2191. Similarly, the base station 2112 need not be aware of the future routing of an outgoing uplink communication originating from the UE 2191 towards the host computer 2130.

By virtue of the method 300 being performed by any one of the UEs 2191 or 2192 and/or the method 400 being performed by any one of the network node (e.g., base stations) 2112, the performance or range of the OTT connection 2150 can be improved, e.g., in terms of increased throughput and/or reduced latency. More specifically, the host computer 2130 may indicate to wireless device 100, network node 220, the first peer wireless device 210 and/or the RAN (e.g., on an application layer) any one of the triggering conditions (e.g., of the second detailed embodiment), e.g., a QoS of the traffic.

Example implementations, in accordance with an embodiment of the UE, base station and host computer discussed in the preceding paragraphs, will now be described with reference to Fig. 22. In a communication system 2200, a host computer 2210 comprises hardware 2215 including a communication interface 2216 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 2200. The host computer 2210 further comprises processing circuitry 2218, which may have storage and/or processing capabilities. In particular, the processing circuitry 2218 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The host computer 2210 further comprises software 2211, which is stored in or accessible by the host computer 2210 and executable by the processing circuitry 2218. The software 2211 includes a host application 2212. The host application 2212 may be operable to provide a service to a remote user, such as a UE 2230 connecting via an OTT connection 2250 terminating at the UE 2230 and the host computer 2210. In providing the service to the remote user, the host application 2212 may provide user data, which is transmitted using the OTT connection 2250. The user data may depend on the location of the UE 2230. The user data may comprise auxiliary information or precision advertisements (also: ads) delivered to the UE 2230. The location may be reported by the UE 2230 to the host computer, e.g., using the OTT connection 2250, and/or by the base station 2220, e.g., using a connection 2260. The communication system 2200 further includes a base station 2220 provided in a telecommunication system and comprising hardware 2225 enabling it to communicate with the host computer 2210 and with the UE 2230. The hardware 2225 may include a communication interface 2226 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 2200, as well as a radio interface 2227 for setting up and maintaining at least a wireless connection 2270 with a UE 2230 located in a coverage area (not shown in Fig. 22) served by the base station 2220. The communication interface 2226 may be configured to facilitate a connection 2260 to the host computer 2210. The connection 2260 may be direct, or it may pass through a core network (not shown in Fig. 22) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 2225 of the base station 2220 further includes processing circuitry 2228, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The base station 2220 further has software 2221 stored internally or accessible via an external connection.

The communication system 2200 further includes the UE 2230 already referred to. Its hardware 2235 may include a radio interface 2237 configured to set up and maintain a wireless connection 2270 with a base station serving a coverage area in which the UE 2230 is currently located. The hardware 2235 of the UE 2230 further includes processing circuitry 2238, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The UE 2230 further comprises software 2231, which is stored in or accessible by the UE 2230 and executable by the processing circuitry 2238. The software 2231 includes a client application 2232. The client application 2232 may be operable to provide a service to a human or non-human user via the UE 2230, with the support of the host computer 2210. In the host computer 2210, an executing host application 2212 may communicate with the executing client application 2232 via the OTT connection 2250 terminating at the UE 2230 and the host computer 2210. In providing the service to the user, the client application 2232 may receive request data from the host application 2212 and provide user data in response to the request data. The OTT connection 2250 may transfer both the request data and the user data. The client application 2232 may interact with the user to generate the user data that it provides.

It is noted that the host computer 2210, base station 2220 and UE 2230 illustrated in Fig. 22 may be identical to the host computer 2130, one of the base stations 2112a, 2112b, 2112c and one of the UEs 2191, 2192 of Fig. 21, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 22, and, independently, the surrounding network topology may be that of Fig. 21.

In Fig. 22, the OTT connection 2250 has been drawn abstractly to illustrate the communication between the host computer 2210 and the UE 2230 via the base station 2220, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the UE 2230 or from the service provider operating the host computer 2210, or both. While the OTT connection 2250 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

The wireless connection 2270 between the UE 2230 and the base station 2220 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 2230 using the OTT connection 2250, in which the wireless connection 2270 forms the last segment. More precisely, the teachings of these embodiments may reduce the latency and improve the data rate and thereby provide benefits such as better responsiveness and improved QoS.

A measurement procedure may be provided for the purpose of monitoring data rate, latency, QoS and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 2250 between the host computer 2210 and UE 2230, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 2250 may be implemented in the software 2211 of the host computer 2210 or in the software 2231 of the UE 2230, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 2250 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 2211, 2231 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 2250 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 2220, and it may be unknown or imperceptible to the base station 2220. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer's 2210 measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the software 2211, 2231 causes messages to be transmitted, in particular empty or "dummy" messages, using the OTT connection 2250 while it monitors propagation times, errors etc.

Fig. 23 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 21 and 22. For simplicity of the present disclosure, only drawing references to Fig. 23 will be included in this paragraph. In a first step 2310 of the method, the host computer provides user data. In an optional substep 2311 of the first step 2310, the host computer provides the user data by executing a host application. In a second step 2320, the host computer initiates a transmission carrying the user data to the UE. In an optional third step 2330, the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional fourth step 2340, the UE executes a client application associated with the host application executed by the host computer.

Fig. 24 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 21 and 22. For simplicity of the present disclosure, only drawing references to Fig. 24 will be included in this paragraph. In a first step 2410 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In a second step 2420, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step 2430, the UE receives the user data carried in the transmission.

As has become apparent from above description, at least some embodiments of the technique allow increasing the reliability and latency in a wireless communication system. In fact, the legacy Uu operation may benefits from the capillary deployment and latencies of the sidelink UEs. Alternatively or in addition, radio link failure can be reduced, e.g., as the present of multipaths allow a UE to have multiple choices for possible radio link recovery procedures.

Same or further embodiments work for in-coverage, out-of-coverage and partial coverage scenarios enhancing the reliability of the transmissions in all of them, and additionally, increasing the network coverage (potentially) for the latter scenario.

Many advantages of the present invention will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the invention and/or without sacrificing all of its advantages. Since the invention can be varied in many ways, it will be recognized that the invention should be limited only by the scope of the following embodiments.

Claims

1. A method (300) of establishing a dual connectivity, DC (1500), of a wireless device (100; 1900; 2191; 2192; 2230), the method (300) comprising or initiating the steps of: establishing (302) a first path (1510) of the DC (1500), wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100;

1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210); and establishing (304) a second path (1520) of the DC (1500), wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

2. The method (300) of claim 1, wherein the at least one station (220) is or comprises one or more network nodes or one or more cell groups, and/or wherein a wireless access network (500) comprises the at least one station (220; 230).

3. The method (300) of claim 2, wherein the at least one station (220) is or comprises at least one of a master node, MN, of the DC (1500), a master cell group, MCG, of the DC (1500), a secondary node, SN, of the DC (1500), and a secondary cell group, SCG, of the DC (1500).

4. The method (300) of any one of claims 1 to 3, wherein the second path (1520) of the DC (1500) is wirelessly connected towards the at least one station (220) using at least one of an uplink, a downlink, and a Uu interface (1522) between the wireless device (100; 1900; 2191; 2192; 2230) and the at least one station (220).

5. The method (300) of any one of claims 1 to 4, wherein the first peer wireless device (210) is a relay wireless device relaying the first path (1510) of the DC (1500) from the wireless device (100; 1900; 2191; 2192; 2230) to the at least one station (220) and/or to the wireless access network (500) comprising the at least one station (220). 6. The method (300) of claim 5, wherein the second path (1520) is wirelessly connected towards one station (220), and the first path (1510) of the DC (1500) is relayed to the one station (220), optionally wherein the one station (220) is or comprises both a master node, MN, and a secondary node, SN, of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

7. The method (300) of any one of claims 1 to 5, wherein the at least one station (220) is at least one network node of a wireless access network (500), and wherein the first peer wireless device (210) is a relay wireless device relaying the first path (1510) of the DC (1500) from the wireless device (100; 1900; 2191; 2192; 2230) to at least one further network node (222) of the wireless access network (500) comprising the at least one network node (220).

8. The method (300) of claim 7, wherein the at least one further network node (222) is or comprises a MN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230), and/or wherein the at least one a station (220) is or comprises at least one SN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

9. The method (300) of claim 7, wherein the at least one further network node (222) is or comprises at least one SN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230), and/or wherein the at least one a station (220) is or comprises a MN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

10. The method (300) of any one of claims 1 to 9, wherein the at least one station (220) is or comprises a second peer wireless device.

11. The method (300) of claim 10, wherein the second path (1520) of the DC is wirelessly connected towards the second peer wireless device (220) using at least one of a second SL (1622) and a PC5 interface (1622) between the wireless device (100; 1900; 2191; 2192; 2230) and the second peer wireless device (220).

12. The method (300) of claim 10 or 11, wherein the first peer wireless device (210) is a relay wireless device relaying the first path (1510) of the DC (1500) from the wireless device (100; 1900; 2191; 2192; 2230) to the second peer wireless device (220), optionally wherein the second peer wireless device (220) is or comprises both a master node, MN, and a secondary node, SN, of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

13. The method (300) of claim 11, wherein the first peer wireless device (210) is a relay wireless device relaying the first path (1510) of the DC (1500) from the wireless device (100; 1900; 2191; 2192; 2230) to at least one further wireless device other than the second peer wireless device (220).

14. The method (300) of claim 13, wherein the at least one further wireless device is or comprises a MN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230), and/or wherein the second peer wireless device (220) is or comprises at least one SN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

15. The method (300) of claim 13, wherein the at least one further wireless device is or comprises a SN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230), and/or wherein the second peer wireless device (220) is or comprises at least one MN of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

16. The method (300) of any one of claims 1 to 15, wherein a wireless ad hoc network (1600) comprises at least one of the wireless device (100; 1900; 2191; 2192; 2230), the first peer wireless device (210) and the at least one station (220).

17. The method (300) of any one of claims 1 to 16, wherein the wireless connection of the first path (1510) from the wireless device (100; 1900; 2191; 2192; 2230) towards the first peer wireless device (210) using the first SL (1512) between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210) is a master link of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230), and/or wherein the wireless connection of the second path (1520) from the wireless device (100; 1900; 2191; 2192; 2230) towards the at least one station (220) is a secondary link of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

18. The method (300) of any one of claims 1 to 17, wherein the wireless connection of the first path (1510) from the wireless device (100; 1900; 2191; 2192; 2230) towards the first peer wireless device (210) using the first SL (1512) between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210) is a secondary link of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230), and/or wherein the wireless connection of the second path (1520) from the wireless device (100; 1900; 2191; 2192; 2230) towards the at least one station (220) is a master link of the DC (1500) of the wireless device (100; 1900; 2191; 2192; 2230).

19. The method (300) of any one of claims 1 to 18, wherein both the first path (1502) and the second path (1504) carry a radio bearer, RB, that is anchored at an entity of an anchoring layer, optionally an anchoring layer of the MN or the SN.

20. The method (300) of claim 19, wherein the anchoring layer comprises at least one of a medium access control, MAC, layer; a radio link control, RLC, layer; a packet data convergence protocol, PDCP, layer; a radio resource control, RRC, layer; and a service data adaptation protocol, SDAP, layer.

21. The method (300) of claim 19 or 20, wherein the bearer is at least one of split and duplicated at a split layer below the anchoring layer.

22. The method (300) of claim 21, wherein the split layer comprises at least one of a physical, PHY, layer; a medium access control, MAC, layer; a radio link control, RLC, layer; a packet data convergence protocol, PDCP, layer; and a radio resource control, RRC, layer.

23. The method (300) of any one of claims 19 to 22, wherein the bearer is a split bearer (800) anchored at a PDCP entity associated with one or two Unacknowledged Mode, UM, RLC entities for the first path (1502) and associated with one or two UM RLC entities for the second path (1504).

24. The method (300) of any one of claims 19 to 22, wherein the bearer is a split bearer (800) anchored at a PDCP entity associated with one Acknowledged Mode, AM, RLC entities for the first path (1502) and associated with one AM RLC entities for the second path (1504). 25. The method (300) of any one of claims 19 to 22, wherein the bearer is configured for duplication at a PDCP entity associated with N or 2N UM RLC entities for the first path (1502) and associated with N or 2N UM RLC entities for the second path (1504).

26. The method (300) of any one of claims 19 to 22, wherein the bearer is configured for duplication at a PDCP entity associated with N AM RLC entities for the first path (1502) and associated with N AM RLC entities for the second path (1504).

27. The method (300) of any one of claims 1 to 26, wherein the first path (1502) carries a first non-split RB, and/or the second path (1504) carries a second non split RB.

28. The method (300) of any one of claims 1 to 27, wherein a first non-split RB mapped to the first path (1502) is associated with a first PDCP entity and one or two first UM RLC entities or one first AM RLC entity, and/or wherein a second non-split RB mapped to the second path (1502) is associated with a second PDCP entity and one or two second UM RLC entities or one second AM RLC entity.

29. The method (300) of any one of claims 1 to 28, further comprising or initiating the step of: transmitting data packets from the wireless device (100; 1900; 2191; 2192; 2230) to the first peer wireless device (210) in the first path (1510) of the DC.

30. The method (300) of any one of claims 1 to 29, further comprising or initiating the step of: transmitting data packets from the wireless device (100; 1900; 2191; 2192; 2230) to the at least one station (220) in the second path (1520) of the DC.

31. The method (300) of any one of claims 1 to 30, wherein the DC (1500) is a multi-connectivity comprising more than two paths (1510, 1520), and/or wherein the step of establishing (302) the first path (1510) further comprises establishing a third path (1510) of the DC (1500), wherein the third path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a third peer wireless device (210) using a third SL (1512) between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210), and/or wherein the step of establishing (304) the second path (1520) further comprises establishing (304) a fourth path (1520) of the DC (1500), wherein the fourth path (1520) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first and third peer wireless device (210).

32. The method (300) of claim 31, wherein the wireless device (100; 1900;

2191; 2192; 2230) establishes (302; 304) as many paths (1510, 1520), or wireless connections of the paths, of the multi-connectivity (1500) as supported by the wireless device (100; 1900; 2191; 2192; 2230).

33. The method (300) of any one of claims 1 to 32, wherein at least one or each of the establishing steps (302, 304) is performed according to at least one of the following triggering conditions: according to a triggering condition that depends on, or is controlled, by at least one of a service using the DC (1500), an application using the DC (1500), and a traffic transmitted using the DC (1500); in predefined or configured geographical location; when a volume of data pending for transmission at the wireless device (100; 1900; 2191; 2192; 2230) is greater than a predefined or configured threshold value; when a volume of data pending for transmission at the wireless device (100; 1900; 2191; 2192; 2230) is greater than a predefined or configured first threshold value and less than a predefined or configured second threshold value; when a signal strength of one or each of the at least one network node (220) at the Uu interface (1522) is less than a predefined or configured threshold value; when a signal strength of one or each of the at least one network node (220) at the Uu interface (1522) is greater than a predefined or configured first threshold value and less than a predefined or configured second threshold value; upon an indication and/or configuration from the at least one network node (220) or the wireless access network (500); upon an indication and/or configuration from the peer wireless device

(210); upon an indication from an upper layer of a communication protocol stack at the wireless device (100; 1900; 2191; 2192; 2230); and upon an indication received from a host computer of an application and/or service used at the wireless device (100; 1900; 2191; 2192; 2230).

34. The method (300) of any one of claims 1 to 33, wherein the wireless device (100; 1900; 2191; 2192; 2230) selects whether to use one, a portion, or all of the established paths 1510 or 1520, optionally every time that a data packet for transmission becomes available at the wireless device (100; 1900; 2191; 2192; 2230).

35. The method (300) of any one of claims 1 to 34, wherein the method (300) is performed by the wireless device (100; 1900; 2191; 2192; 2230).

36. A method (400) of controlling a wireless device (100; 1900; 2191; 2192; 2230) to establish a dual connectivity, DC (1500), of the wireless device (100; 1900; 2191; 2192; 2230), the method (400) comprising or initiating the steps of: controlling (402) the wireless device (100; 1900; 2191; 2192; 2230) to establish a first path (1510) of the DC (1500), wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210); and controlling (404) the wireless device (100; 1900; 2191; 2192; 2230) to establish a second path (1520) of the DC (1500), wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

37. The method (400) of claim 36, wherein at least on or each of the steps (402, 404) of controlling the wireless device (100; 1900; 2191; 2192; 2230) uses at least one of: radio resource control, RRC, signaling; a medium access control, MAC, control entity, CE; and a signaling of a physical layer, optionally on a physical random access channel, PRACH, and/or a physical uplink control channel, PUCCH, and/or physical downlink control channel, PDCCH. 38. The method (400) of claim 36 or 37, wherein the method (400) is performed by the at least one station (220).

39. The method of any one of claims 36 to 38, further comprising the features or steps of any one of claims 2 to 35, or any feature or step corresponding thereto.

40. A computer program product comprising program code portions for performing the steps of any one of the claims 1 to 35 or 36 to 39 when the computer program product is executed on one or more computing devices (1904; 1204), optionally stored on a computer-readable recording medium (1106; 1206).

41. A wireless device (100; 1900; 2191; 2192; 2230) for establishing a dual connectivity, DC (1500), of the wireless device (100; 1900; 2191; 2192; 2230), the wireless device (100; 1900; 2191; 2192; 2230) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the wireless device (100; 1900; 2191; 2192; 2230) is operable to: establish (302) a first path (1510) of the DC (1500), wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210); and establish (304) a second path (1520) of the DC (1500), wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

42. The wireless device (100; 1900; 2191; 2192; 2230) of claim 41, further operable to perform the steps of any one of claims 2 to 35.

43. A wireless device (100; 1900; 2191; 2192; 2230) for establishing a dual connectivity, DC (1500), of the wireless device (100; 1900; 2191; 2192; 2230), configured to: establish (302) a first path (1510) of the DC (1500), wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210); and establish (304) a second path (1520) of the DC (1500), wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

44. The wireless device (100; 1900; 2191; 2192; 2230) of claim 43, further configured to perform the steps of any one of claims 2 to 35.

45. A network node (220) for controlling a wireless device (100; 1900; 2191; 2192; 2230) to establish a dual connectivity, DC (1500), of the wireless device (100; 1900; 2191; 2192; 2230), the network node (220) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the network node (220) is operable to: control the wireless device (100; 1900; 2191; 2192; 2230) to establish a first path (1510) of the DC (1500), wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210); and control the wireless device (100; 1900; 2191; 2192; 2230) to establish a second path (1520) of the DC (1500), wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

46. The network node (220) of claim 45, further comprising any feature or being operable to perform any step of any one of the claims 36 to 39.

47. A network node (220) for controlling a wireless device (100; 1900; 2191; 2192; 2230) to establish a dual connectivity, DC (1500), of the wireless device (100; 1900; 2191; 2192; 2230), the network node (220) being configured to: control the wireless device (100; 1900; 2191; 2192; 2230) to establish a first path (1510) of the DC (1500), wherein the first path (1510) of the DC (1500) is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards a first peer wireless device (210) using a first sidelink, SL (1512), between the wireless device (100; 1900; 2191; 2192; 2230) and the first peer wireless device (210); and control the wireless device (100; 1900; 2191; 2192; 2230) to establish a second path (1520) of the DC (1500), wherein the second path (1520) of the DC is wirelessly connected from the wireless device (100; 1900; 2191; 2192; 2230) towards at least one station (220) other than the first peer wireless device (210).

48. The network node (220) of claim 47, further comprising any feature or being configured to perform any step of any one of claims 36 to 39.

49. A communication system (2100; 2200) including a host computer (2130; 2210) comprising: processing circuitry (2218) configured to provide user data; and a communication interface (2216) configured to forward user data to a cellular or ad hoc radio network (500; 1310) for transmission to a user equipment, UE, (100; 1900; 2191; 2192; 2230) wherein the UE (100; 1900; 2191; 2192; 2230) comprises a radio interface (1902; 2237) and processing circuitry (1904; 2238), the processing circuitry (1904; 2238) of the UE (100; 1900; 2191; 2192; 2230) being configured to execute the steps of any one of claims 1 to 35.

50. The communication system (2100; 2200) of claim 49, further including the UE (100; 1900; 2191; 2192; 2230).

51. The communication system (2100; 2200) of claim 49 or 50, wherein the radio network (1310) further comprises a base station (220; 2000; 2112; 2220), or a radio device (100; 210; 1900; 2191; 2192; 2230) functioning as a gateway, which is configured to communicate with the UE (100; 1900; 2191; 2192; 2230).

52. The communication system (2100; 2200) of claim 51, wherein the base station (220; 2000; 2112; 2220), or the radio device (100; 210; 1900; 2191; 2192; 2230) functioning as a gateway, comprises processing circuitry (1904; 2228), which is configured to execute the steps of any one of claims 36 to 39.

53. The communication system (2100; 2200) of any one of claims 49 to 52, wherein: the processing circuitry (2218) of the host computer (2130; 2210) is configured to execute a host application (2212), thereby providing the user data; and the processing circuitry (1904; 2238) of the UE (100; 1900; 2191; 2192; 2230) is configured to execute a client application (2232) associated with the host application (2212).