WO2023230882A1

WO2023230882A1 - Traffic offloading

Info

Publication number: WO2023230882A1
Application number: PCT/CN2022/096366
Authority: WO
Inventors: Xiang Xu; Esa Mikael MALKAMÄKI; Henri Markus Koskinen; Matti Einari Laitila
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2023-12-07

Abstract

Example embodiments of the present disclosure relate to traffic offloading in a communication network. A first device receives, from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device. The traffic comprises first traffic to be communicated between the second device and a third device in the radio access network via a first target device in the radio access network. The first device selects, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device. The first device transmits, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.

Description

TRAFFIC OFFLOADING

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to devices, methods, apparatuses and computer readable storage medium for offloading traffic in a communication network.

BACKGROUND

A communication system may comprise one or more integrated access and backhaul (IAB) nodes. An IAB donor has connectivity (e.g. a fiber connectivity) with a core network. The IAB donor may be implemented as a gNB that terminates wireless backhaul radio interface from one or more IAB nodes. The IAB donor may serve directly connected IAB nodes and IAB nodes that are chained over multiple wireless backhaul hops. The IAB donor may also serve directly connected terminal devices. The IAB donor may comprise a central unit (CU) and one or more distributed units (DUs) .

An IAB node may serve one or more terminal devices directly connected to the IAB node. The IAB node may also serve one or more child IAB nodes connected to the IAB node. The IAB node may comprise a DU (also referred to as IAB-DU) , and a mobile termination (also referred to as IAB-MT) that maintains connectivity with one or more parent nodes (using, for example, dual connectivity) .

An IAB topology in a communication system may be non-static since a migration may be performed. For example, a handover may be performed for the IAB-MT based on signal strength, signal quality or other factors.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for offloading traffic in a communication network. Embodiments that do not fall under the scope of the claims, if any, are to be interpreted as examples useful for understanding various embodiments of the disclosure.

In a first aspect, there is provided a first device in a radio access network. The first device comprises at least one processor; and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to: receive, from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; select, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and transmit, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device

In a second aspect, there is provided a second device in a radio access network. The second device comprises at least one processor; and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to: transmit, to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; receive, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device; and communicate the first traffic using the first configuration information.

In a third aspect, there is provided a third device in a radio access network. The third device comprises at least one processor; and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to: receive, from a first device or a second device in the radio access network, first configuration information for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device; and communicate the first traffic using the first configuration information.

In a fourth aspect, there is provided a method. The method may be performed by a first device and comprises: receiving, at a first device in a radio access network from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; selecting, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and transmitting, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.

In a fifth aspect, there is provided a method. The method may be performed by a second device and comprises: transmitting, from a second device in a radio access network to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; receiving, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device; and communicating the first traffic using the first configuration information.

In a sixth aspect, there is provided a method. The method may be performed by a third device and comprises: receiving, at a third device in a radio access network from a first device or a second device in the radio access network, first configuration information to be used for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device; communicating the first traffic using the first configuration information.

In a seventh aspect, there is provided a first apparatus. The first apparatus comprises: means for receiving, from a second device in a radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with a first device in the radio access network, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; means for selecting, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and means for transmitting, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.

In an eighth aspect, there is provided a second apparatus. The second apparatus comprises: means for transmitting, to a first device in a radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; means for receiving, from the first device, first configuration information for communicating the first traffic between a second device in the radio access network and the third device via a second target device, wherein the second target device is associated with the first device; and means for communicating the first traffic using the first configuration information.

In a ninth aspect, there is provided a third apparatus. The third apparatus comprises: means for receiving, from a first device or a second device in a radio access network, first configuration information for communicating first traffic between a second device in the radio access network and a third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device; means for communicating the first traffic using the first configuration information.

In a tenth aspect, there is provided a computer readable medium. The computer readable medium comprises program instructions that, when executed by at least one processor, cause an apparatus to perform at least the method according to the fourth aspect.

In an eleventh aspect, there is provided a computer readable medium. The computer readable medium comprises program instructions that, when executed by at least one processor, cause an apparatus to perform at least the method according to the fifth aspect.

In a twelfth aspect, there is provided a computer readable medium. The computer readable medium comprises program instructions that, when executed by at least one processor, cause an apparatus to perform at least the method according to the sixth aspect.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1 illustrates an example communication network in which example embodiments of the present disclosure can be implemented;

Fig. 2 illustrates a signaling chart illustrating a process for offloading traffic in accordance with some example embodiments of the present disclosure;

Fig. 3 illustrates a signaling chart illustrating a process for offloading traffic in accordance with some other example embodiments of the present disclosure;

Fig. 4 illustrates a flowchart of a method implemented at a first device in accordance with some example embodiments of the present disclosure;

Fig. 5 illustrates a flowchart of a method implemented at a second device in accordance with some example embodiments of the present disclosure;

Fig. 6 illustrates a flowchart of a method implemented at a third device in accordance with some example embodiments of the present disclosure;

Fig. 7 illustrates a simplified block diagram of an apparatus that is suitable for implementing example embodiments of the present disclosure; and

Fig. 8 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device, or communication between network devices in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems or networks. Given the rapid development in communications, there will of course also be future type communication technologies, networks and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system/network.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated and Access Backhaul (IAB) node, an IAB-DU, and IAB-CU, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Fig. 1 shows an example communication environment 100 in which example embodiments of the present disclosure can be implemented. The communication environment 100 may comprise a core network (CN) 105, a first device 110, a second device 120, a third device 130, a first target device 140, a second target device 150,

parent devices

160 and 170, a source device 180 and a terminal device 190.

In the example of Fig. 1, the third device 130 is connected to the second device 120 via the parent device 160 and the source device 180. After a migration, the third device 130 is connected to the first device 110 via the parent device 170 and the first target device 140 and/or via the parent device 170 and the second target device 150. The terminal device 190 accesses the communication environment 100 via the third device 130.

In some embodiments, the communication environment 100 may comprise one or more intermediate device (s) between the source device 180 and the parent device 160, one or more intermediate device (s) between the first target device 140 and the parent device 170, and/or one or more intermediate device (s) between the second target device 150 and the parent device 170.

In some embodiments, the communication environment 100 may be implemented as an IAB network. In such embodiments, each of the first device 110 and the second device 120 may be implemented as an IAB-donor-CU, each of the source device 180, the first target device 140 and the second target device 150 may be implemented as an IAB-donor-DU, and each of the third device 130, the parent device 160 and the parent device 170 may be implemented as an IAB-node.

In embodiments where the communication environment 100 is implemented as an IAB network, the IAB-donor-CU and one or more IAB-donor-DUs may be collectively referred to as an IAB-donor. For example, in the example of Fig. 1, the second device 120 and the source device 180 may be collectively referred to as one IAB-donor. Similarly, the first device 110, the first target device 140 and the second target device 150 may be collectively referred to as another IAB-donor.

Each of the IAB-donors may have connectivity (e.g. fiber connectivity) with the CN 105. Each of the IAB-donors may serve directly connected IAB-nodes (not shown) and IAB-nodes that are chained over multiple wireless backhaul hops. For example, the IAB-donor comprising the first device 110, the first target device 140 and the second target device 150 may serve the parent device 170 acting as an IAB-node.

The IAB-nodes, such as the

devices

130, 160 and 170 acting as IAB-nodes, may serve one or more terminal devices directly connected thereto. For example, as shown in Fig. 1, the third device 130 may serve the terminal device 190 directly connected to the third device 130. The F1 interface for F1 traffic (e.g. the F1 control-plane traffic, or the F1 user-plane traffic) for the terminal device 190 is terminated at the third device 130 and the second device 120.

Hereinafter, a CU of an IAB-donor is also referred to as donor-CU or donor central unit or IAB-donor-CU, and a DU of the IAB-donor is also referred to as donor-DU or donor distributed unit or IAB-donor-DU.

In embodiments where the communication environment 100 is implemented as an IAB network, an IAB node, for example, each of the

devices

130, 160 and 170, may include a DU (IAB-DU) , and a mobile termination (IAB-MT) that maintains connectivity with one or more parent nodes (using for example, dual connectivity) . Similar to a conventional user equipment, the MT of an IAB node may use radio resource control (RRC) signaling, e.g. to supply radio link measurements of alternative parent nodes to its current serving donor-CU. The RRC is terminated at the IAB-MT and the donor-CU. A migration may be performed, for example, a handover is performed for the IAB-MT based on signal strength, signal quality or other factors. Hence, the IAB topology, such as the one as shown in Fig. 1, may be non-static. As a result of the migration, the third device 130 may change the parent node from the parent device 160 (also referred to as a source parent IAB-node 160) to the parent device 170 (also referred to as a target parent IAB-node 170) after the migration, as indicated by an arrow in Fig. 1. In other words, before the migration, the F1 traffic for the terminal device 190 is transferred via the parent device 160 and the source device 180; after the migration, the F1 traffic for the terminal device 190 is transferred via the parent device 170 and the first target device 140 and/or via the parent device 170 and the second target device 150. The IAB topology may change over time as radio conditions fluctuate, and as IAB-nodes move, are added or removed.

A CU (such as donor-CU) may be a logical node which may comprise the functions (for example, gNB functions) such as transfer of user data, mobility control, radio access network sharing, positioning, session management etc., except those functions allocated exclusively to DUs. The CU may control the operation of one or more DUs over a front-haul (F1) interface. A DU is a logical node which may include a subset of the functions (for example, gNB functions) .

It is also to be understood that the architecture as shown in Fig. 1 is described only for the purpose of illustration without suggesting any limitation. In addition, it is to be understood that the number of devices and their connections as shown in Fig. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of devices adapted for implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be deployed in the communication environment 100.

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

During an IAB-node migration, an inter-donor-DU migration is performed when a target donor-DU is different from a source donor-DU. When the source donor-DU and the target donor-DU belong to same donor-CU, an intra-donor-CU inter-donor-DU migration occurs. When the source donor-DU and the target donor-DU belong to different donor-CUs or the source donor-DU and the target donor-DU are connected to different donor-CUs, an inter-donor-CU migration occurs.

In some embodiments, the third device 130 may perform an inter-donor-CU migration procedure, for example, due to handover. In such embodiments, the third device 130 may be referred to as a migrating IAB node. With the migration procedure, the third device 130 may change a communication connection (or a communication path) from the topology of the second device 120 (e.g. the communication path between the third device 130 and the second device 120 using the source device 180 and the parent device 160) to the topology of the first device 110 (e.g. the communication path between the third device 130 and the second device 120 using the first target device 140 and the parent device 170, and/or using the second target device 150 and the parent device 170) by migrating from the parent device 160 to the parent device 170. In such embodiments, the second device 120 may be referred to as a source IAB-donor-CU, the parent device 160 may be referred to as a source parent IAB-node of the third device 130, each of the first target device 140 and the second target device 150 may be referred to as a target IAB-donor-DU, and the parent device 170 may be referred to as a target parent IAB-node of the third device 130.

In an inter-donor-CU migration procedure, traffic between a migrating IAB node and a source IAB-donor-CU may be offloaded to a target IAB-donor’s topology. Current inter-CU topology adaptation procedure imposes restriction for the inter-donor-CU migration and can cause more failure. This is due to the fact that a target IAB-donor-CU selects a target IAB-donor-DU during an Xn Handover Preparation procedure, which is before QoS information about the traffic to be offloaded is sent to the target IAB-donor-CU. Without knowing the QoS information about the traffic to be offloaded, the target IAB-donor-CU may blindly select a target IAB-donor-DU that may not be able to support the traffic.

In case where the target IAB-donor-CU selects the target IAB-donor-DU and assigns a transport network layer (TNL) address anchored at the target IAB-donor-DU, the TNL address will be further sent to the migrating IAB node. During the migration management procedure, a source IAB-donor-CU includes the TNL address in a REQUEST message (e.g. an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message) . When the target IAB-donor-CU receives the REQUEST message, it will try a backhaul (BH) establishment for the communication path between the migrating IAB node and the target IAB-donor-DU. If the BH between the migrating IAB node and the target IAB-donor-DU cannot support the traffic, the target IAB-donor-CU will reject the REQUEST, and thus cause the migration failure.

In accordance with some example embodiments of the present disclosure, there is provided a solution for offloading traffic in a communication network. In this solution, if a first device (for example, a target IAB-donor-CU) determines that a first target device (for example, a first target IAB-donor-DU) fails to support a traffic to be offloaded, the first device selects, based on context of the traffic, a second target device (for example, a second target IAB-donor-DU) for the first traffic. In this way, a migration success rate may be improved.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Fig. 2 illustrates a signaling chart illustrating a process 200 for offloading traffic in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to Fig. 1. The process 200 may involve the first device 110, the second device 120, the third device 130, the first target device 140 and the second target device 150 in Fig. 1.

The first device 110 in a radio access network receives 210, from the second device 120 in the radio access network, context of traffic to be offloaded via the first target device 140 in the radio access network. The first target device 140 is associated with the first device 110, and the traffic comprises first traffic to be communicated between the second device 120 and the third device 130 in the radio access network. The first traffic includes the downlink (DL) traffic and uplink (UL) traffic.

The first device 110 may determine 220, based on the context, whether the first target device 140 supports the first traffic. If the first target device 140 fails to support the first traffic, the first device 110 selects 230, based on the context, the second target device 150 for the first traffic. The second target device 150 is associated with the first device 110.

The first device 110 transmits 240 first configuration information to the second device 120. The first configuration information is for communicating the first traffic between the second device 120 and the third device 130 via the second target device 150. For example, the second device 120 uses the first configuration information (for example, the IPv6 flow label, TNL address, etc) to send the downlink traffic to the third device, via the second target device 150 and the topology of the first device 110.

In one example embodiment, the third device 130 is still connected with the source parent device (for example, the RRC of the MT of the third device 130 is terminated at the second device 120) . Upon receiving the first configuration information, the second device 120 transmits 250 the first configuration information to the third device 130. In some embodiments, the second device 120 may transmit the first configuration information to the third device 130 via intermediate IAB nodes if any.

In another example embodiment, the third device 130 is connected to the target parent device (for example, the RRC of the MT of the third device 130 is terminated at the first device 110) , and the first device 110 may transmit 260 the first configuration information to the third device 130, via intermediate IAB nodes if any.

In some embodiments, optionally, the second device 120 may transmit 265 to the third device 130 an indication to apply the first configuration information for communicating the first traffic, via intermediate IAB nodes if any. The indication may be sent via F1AP signaling, e.g., as F1AP message that may configure the UL mapping for the third device 130 (i.e., maps a given F1-U tunnel with a given UL BAP Routing ID and a given BH RLC channel) and based on the mapping, the third device 130 (for example, an IAB-node) may know which source IP address to use for the UL data.

In turn, the second device 120 communicates the first traffic using the first configuration information. For example, the second device 120 may transmit 270 the downlink (DL) first traffic using the first configuration information. The first traffic is transferred to the third device 130 via the second target device 150. Accordingly, the third device 130 receives the downlink first traffic using the first configuration information. Similarly, the third device 130 may transmit 280 the uplink (UL) first traffic using the first configuration information. The first traffic is transferred to the second device 120 via the second target device 150. Accordingly, the second device 120 receives the uplink first traffic using the first configuration information.

With the process 200, a migration success rate may be improved by allowing the first device (for example, a target IAB-donor-CU) to modify the previously selected first target device (for example, a target IAB-donor-DU) .

In some embodiments, the context may comprise Quality of Service (QoS) information associated with the traffic to be offloaded. In such embodiments, the context may comprise QoS information associated with all of the traffic to be offloaded. In other words, the traffic may comprise the traffic on multiple F1-U tunnels between the second device 120 and the third device 130, and the QoS information may be an aggregated QoS information.

In some embodiments, the traffic to be offloaded may comprise at least one of user plane traffic and control plane traffic, and the context may comprise QoS information associated with the user plane traffic. In such embodiments, the context may comprise QoS information associated with traffic on each F1-U tunnel. In other words, the traffic may comprise traffic on multiple F1-U tunnels, and traffic on each F1-U tunnel has associated QoS information.

In some embodiments, the first device 110 may receive, from the second device 120, the context of the traffic to be offloaded after receiving from the second device 120 a handover request message or a secondary node addition request message for offloading the traffic. In such embodiments, the first device 110 may receive the context of the traffic in an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message from the second device 120.

Alternatively, the first device 110 may receive, from the second device 120, the context of the traffic to be offloaded in a handover request message or a secondary node addition request message for offloading the traffic.

For example, the first device 110 may receive the context of the traffic via Traffic To Be Added List in the IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message or a HANDOVER REQUEST message or an S-NODE ADDITION REQUEST message. Table 1 shows an example of the Traffic To Be Added List.

Table 1

In Table 1, the Traffic Index may identify the traffic offloaded to the topology of non-F1-terminating IAB-donor-CU, for example the first device 110. The Traffic Profile may indicate Traffic QoS parameters for F1 User plane interface (F1-U) traffic or non-UP traffic type. The F1-terminating Topology BH Information provides BH information of the traffic used in F1-terminating donor’s topology. For example, the F1-terminating Topology BH Information may at least comprise BH Info Index and DL transport network layer (TNL) address for the third device 130. The DL TNL address for the third device 130 may be assigned by a target device, for example, the first target device 140. The first device 110 can know the target device, for example, the first target device 140, based on the DL TNL address.

In some embodiments, the traffic to be offloaded may comprise at least one of user plane traffic and control plane traffic.

In some embodiments, the context comprises QoS information associated with the at least the user plane traffic. For example, the user plane traffic may comprise F1-U traffic. The context may comprise QoS information of each F1-U tunnel.

In some embodiments, the first configuration information may comprise at least one of the following related to the second target device 150:

· a TNL address for the third device 130 anchored at the second target device 150,

· an Internet Protocol version 6 (IPv6) flow label,

· a differentiated services code point (DSCP) ,

· a backhaul adaptation protocol (BAP) routing identifier (ID) associated with the second target device 150,

· a backhaul radio link control channel configuration, or

· a BAP layer configuration.

In some embodiments, the first device 110 may transmit to the second device 120 the first configuration information in an IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE message or a HANDOVER REQUEST ACKNOWLEDGE message or an S-NODE ADDITION REQUEST ACKNOWLEDGE message.

In some embodiments, the first device 110 may transmit the first configuration information via Traffic Added List in the IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE message. Table 2 shows an example of the Traffic Added List.

Table 2

In Table 2, the Traffic Index may identify the traffic offloaded to the topology of non-F1-terminating IAB-donor-CU, for example, the first device 110. The Non-F1-terminating Topology BH Information IE may provide BH information of the traffic used in non-F1-terminating donor’s topology. Table 3 shows an example of the Non-F1-terminating Topology BH Information IE.

Table 3

In Table 3, the First configuration information may include the New TNL Address IE, which may indicate an IPv4 or IPv6 address or an IPv6 address prefix assigned to an IAB-node, for example, the third device 130. The first configuration information may include other information, e.g. BAP related configuration, not shown in Table 3. Table 4 shows an example of the New TNL Address IE.

Table 4

Fig. 3 illustrates a signaling chart illustrating a process 300 for offloading traffic in accordance with some example embodiments of the present disclosure. The process 300 may be considered as an example implementation of the process 200. For the purpose of discussion, the process 300 will be described with reference to Fig. 1. The process 300 may involve the CN 105, the first device 110, the second device 120, the third device 130, the first target device 140, the second target device 150, the

parent devices

160 and 170, and the terminal device 190 in Fig. 1.

In some example embodiments, the process 300 may be performed in an IAB inter-CU topology adaptation procedure for the third device 130 (which also referred to as the migrating device 130) . Thus, the process 300 will be described in combination with IAB inter-CU topology adaptation procedure. However, the process 300 may be performed independent from the IAB inter-CU topology adaptation procedure

The second device 120 sends 301 a HANDOVER REQUEST message to the first device 110 over the Xn interface. This message may comprise TNL address information of the third device 130 in a radio resource control (RRC) container.

In some embodiments, the HANDOVER REQUEST message may comprise context of traffic to be offloaded (for example, QoS requirements of the traffic to be offloaded) . The QoS requirements may be indicated as QoS flow level, F1-U tunnel level QoS parameters or source donor may determine aggregated QoS requirement for all migrated traffic. The aggregated QoS requirement may for instance be the aggregated data rate of the traffic to be offloaded.

Upon the reception of the HANDOVER REQUEST message, the first device 110 may select the first target device 140 for the first traffic, and request the first target device 140 to assign at least one TNL address anchored at the first target device 140 for the third device 130.

The first device 110 sends 302 a UE CONTEXT SETUP REQUEST message to the parent device 170 to create UE context for a migrating IAB-MT in the third device 130 and set up one or more bearers. These bearers may be used by the migrating IAB-MT for its own signalling. Optionally, these bearers may be used by the migrating IAB-MT for data traffic.

The parent device 170 responds 303 to the first device 110 with a UE CONTEXT SETUP RESPONSE message.

The first device 110 performs 304 admission control and provides the new RRC configuration as part of the HANDOVER REQUEST ACKNOWLEDGE message. The RRC configuration comprises a BAP address for the third device 130 in the first device 110’s topology, default BH RLC channel and a default BAP routing ID configuration for UL F1-C/non-F1 traffic mapping on a target path. The RRC configuration may comprise the new TNL address (es) anchored at the target device 140 for the third device 130.

The second device 120 sends 305 a UE CONTEXT MODIFICATION REQUEST message to the parent device 160. The message comprises the received RRCReconfiguration message from the first device 110.

The parent device 160 forwards 306 the received RRCReconfiguration message to the third device 130.

The parent device 160 responds 307 to the second device 120 with the UE CONTEXT MODIFICATION RESPONSE message.

A random access procedure is performed 308 at the parent device 170.

The third device 130 responds 309 to the parent device 170 with an RRCReconfigurationComplete message.

The parent device 170 sends 310 a UL RRC MESSAGE TRANSFER message to the first device 110 to convey the received RRCReconfigurationComplete message.

The first device 110 triggers 311 the path switch procedure for the third device 130, if needed.

The first device 110 sends 312 UE CONTEXT RELEASE message to the second device 120.

It will be noted that the XnAP UE IDs of the third device 130 are retained at the first device 110 and the second device 120 as long as the target path is used for transport of traffic between the third device 130 and the second device 120.

The second device 120 may release 313 BH RLC channels and BAP-sublayer routing entries on the source path between the parent device 160 and the source device 180.

The first device 110 configures 314 BH RLC channels and BAP-sublayer routing entries on the target path between the third device 130 and the target device 140, as well as DL mappings on the target device 140 for the third device 130’s target path. These configurations support the transport of F1-C traffic on the target path.

The F1-C connection between the third device 130 and the second device 120 may be switched 315 to the target path using the new TNL address information of the third device 130. The third device 130 may report the new TNL address information it wants to use for each F1-U tunnel and non-UP traffic type to the second device 120 via the gNB-DU CONFIGURATION UPDATE message.

The second device 120 sends 316 an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message to the first device 110 to provide the context of the traffic to be offloaded. The traffic comprises the first traffic to be transmitted between the second device 120 and the third device 130 via the target device 140. The message may comprise the new DL TNL address information necessary for the first device 110 to configure or modify DL mappings on the target device 140.

In some embodiments, the second device 120 may use one Traffic Index for each of the first traffic and a second traffic. In such embodiments, the context of the traffic may comprise the following information:

· Traffic Index = #1

- BH Info index #101 for the second traffic, DL TNL address for the third device 130 assigned by the first target device 140

· QoS, e.g. 40Mbps for Traffic Index #1

· Traffic Index = #2

- BH Info index #102 for the first traffic, DL TNL address for the third device 130 assigned by the first target device 140

· QoS, e.g. 60Mbps for Traffic Index #2

In some embodiments, the second device 120 may use one Traffic Index for both of the first traffic and the second traffic. In such embodiments, the context of the traffic may comprise the following information:

· Traffic Index = #1

- BH Info index #101 for the second traffic, DL TNL address for the third device 130 assigned by the first target device 140, QoS (e.g. 40Mbps)

- BH Info index #102 for the first traffic, DL TNL address for the third device 130 assigned by the first target device 140, QoS (e.g. 60Mbps)

· QoS, e.g. 100Mbps for Traffic Index #1

At 317, the first device 110 determines whether the first target device 140 supports the first traffic based on the context received at 316. When the first device 110 receives the IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message, it will try to establish the BH between the parent device 170 and the first target device 140.

For example, the QoS (e.g. 40Mbps) for Traffic Index #1, QoS (e.g. 60Mbps) for Traffic Index #2, and the BH between the parent device 170 and the first target device 140 only supports 40Mbps. In this case, the first device 110 determines that the first target device 140 fails to support the traffic identified by the Traffic Index #2.

For another example, the QoS = 100Mbps for Traffic Index #1 and the BH between the parent device 170 and the first target device 140 only supports 40Mbps. In this case, the first device 110 determines that the first target device 140 fails to support the traffic identified by the Traffic Index #1.

If the first target device 140 fails to support the first traffic, the first device 110 selects, based on the context, the second target device 150 for the first traffic.

For example, the QoS = 40Mbps for Traffic Index #1, QoS = 60Mbps for Traffic Index #2, and the BH between the parent device 170 and the second target device 150 supports 70Mbps. In this case, the first device 110 determines that the second target device 150 supports the traffic identified by the Traffic Index #2. In turn, the first device 110 selects the second target device 150 for the traffic identified by the Traffic Index #2.

For another example, the QoS = 100Mbps for Traffic Index #1 and the BH between the parent device 170 and the second target device 150 supports 110Mbps. In this case, the first device 110 determines that the second target device 150 supports the traffic identified by the Traffic Index #1. In turn, the first device 110 selects the second target device 150 for the traffic identified by the Traffic Index #1.

In addition, at 317, the first device 110 may configure or modify BH RLC channels and BAP-sublayer routing entries on the target path between the third device 130 and the second target device 150 as well as DL mappings on the second target device 150 for the target path of the third device 130. These configurations may support the transport of UP and non-UP traffic on the target path.

Furthermore, at 317, the first device 110 may request the second target device 150 to assign the new TNL address for the third device 130. The new TNL address for the third device 130 is anchored at the second target device 150.

At 318, the first device 110 responds to the second device 120 with an IAB Transport Migration Management Response message to provide the first configuration information for communicating the first traffic between the second device 120 and the third device 130 via the second target device 150.

The first configuration information may comprise the new TNL address assigned by the second target device 150. The first configuration information may also comprise the BAP layer configuration that is used in the first device 110’s IAB topology and necessary to configure the third device 130 with the UL mappings of traffic indicated at 316.

The first configuration information may further comprise the DSCP/IPv6 Flow Label values to be used by the second device 120 to send the offloaded downlink traffic, and also to be used to configure the DL mappings of traffic indicated at 317.

In embodiments where the second device 120 uses one Traffic Index for each of the first traffic and the second traffic, the first configuration information for communicating the first traffic between the second device 120 and the third device 130 via the second target device 150 may comprise the following information:

· Traffic Index = #1

- BH Info index #101 is admitted, and the first target device 140 continues to be used

· Traffic Index = #2

- BH Info index #102 is admitted, but a new TNL address is assigned by the second target device 150

In embodiments where the second device 120 uses one Traffic Index for both of the first traffic and the second traffic, the first configuration information for communicating the first traffic between the second device 120 and the third device 130 via the second target device 150 may comprise the following information:

· Traffic Index = #1

In such embodiments, the different traffic identified by one Traffic Index may use different target IAB-donor-DUs even if they use same IAB-donor-DU before topology adaptation.

Upon receiving the first configuration information, the second device 120 may replace the TNL address assigned by the first target device 140 with the new TNL address assigned by the second target device 150 for the traffic identified by BH Info index #102. When sending DL F1-U traffic, this TNL address is used as part of the DL FTEID.

It will be noted that such embodiments do not assume IPsec tunnel. In case IPsec tunnel mode is used, the TNL address is the outer IP address. The third device 130 needs to inform the second device 120 for the new inner TNL address for DL FTEID.

At 318a, the first device 110 sends a UE CONTEXT MODIFICATION REQUEST message to the parent device 170. The message includes an RRCReconfiguration message to be further sent to the third device 130. The RRCReconfiguration message comprises the first configuration information to be used by the third device 130 for sending the uplink offloaded traffic.

At 318b, the parent device 170 forwards the received RRCReconfiguration message to the third device 130. Accordingly, the third device 130 uses the first configuration information to send the uplink offloaded traffic

At 319, the F1-U connections of the third device 130 with the second device 120 may be switched to use the third device 130’s new TNL address (es) . The second device 120 provides to the third device 130 the updated UL BH information for the traffic indicated at 316 based on the UL BH information received from the first device 110 at 318. The second device 120 may also update the UL BH information associated with non-UP traffic. This action may use UE associated signaling or non-UE associated signaling in E1 and/or F1 interface. Implementation must ensure the avoidance of potential race conditions, i.e., no conflicting configurations are concurrently performed using UE-associated and non-UE-associated procedures.

In addition, at 319, the second device 120 transmits, to the third device 130, an indication that the third device 130 uses the first configuration for communicating the first traffic.

Upon receiving the indication, the third device 130 uses the first configuration for communicating the first traffic. For example, the third device 130 may replace the TNL address assigned by the first target device 140 with the new TNL address assigned by the second target device 150 for the first traffic.

When the second device 120 sends the DL F1-U traffic to the third device 130, the IP packet uses the new TNL address assigned by the second target device 150 as a destination address. This IP packet is routed to the second target device 150.

When the third device 130 sends UL F1-U traffic, the BAP header comprises the UL Routing ID including a BAP address of the second target device 150. The source IP address is the new TNL address assigned by the second target device 150. This BAP packet is routed to the second target device 150.

Actions at 316 to 319 are repeated as needed, where the second device 120 can request addition, modification or release of QoS information for non-UP and UP traffic.

In some embodiments, if multiple IP addresses or IPv6 prefix (es) are allocated for the third device 130 for the F1-U traffic, the first device 110 may communicate IP addresses and/or prefixes allocated to the third device 130 in a RRC reconfiguration message at 318a and 318b. The third device 130 derives complete IP addresses from the IPv6 prefix and selects IP addresses for the F1-U tunnels and communicates selected IP addresses to target IAB-donor-DU in an RRC Reconfiguration Complete-message (not shown in Fig. 3) . It should be noted that in such embodiments, the actions at 318a and 318b are performed before the action at 318.

It should be appreciated that the process 300 is just provided as an example without limitation. In some embodiments, similar mechanism for offloading traffic may be used in a different procedure with different signaling flow.

In embodiments where the first device 110 receives the context of the traffic in the handover request message or the secondary node addition request message, the traffic may further comprise second traffic. The first device 110 may select, based on the context, a third target device for the first traffic and a fourth target device for the second traffic. The third and fourth target devices are associated with the first device 110. In turn, the first device 110 may transmit to the second device 120 second configuration information and third configuration information. The second configuration may be for communicating the first traffic between the second device 120 and the third device 130 via the third target device. The third configuration may be for communicating the second traffic between the second device 120 and the third device 130 via the fourth target device.

In some embodiments, the first device 110 may transmit the second configuration information and the third configuration information in a handover request acknowledge message.

In some embodiments, each of the third target device and the fourth target device may comprise an IAB-donor-DU. For example, the third target device and the fourth target device may be implemented as the first target device 140 and the second target device 150, respectively. Alternatively, each of the third target device and the fourth target device may be implemented as other device than the first target device 140 and the second target device 150.

In some embodiments, each of the second configuration information and the third configuration information may comprise information items similar to those in the first configuration information. For example, the second configuration information may comprise at least one of the following related to the third target device:

· a TNL address for the third device 130 anchored at the third target device,

· an Internet Protocol version 6 (IPv6) flow label,

· a differentiated services code point (DSCP) ,

· a backhaul adaptation protocol (BAP) routing identifier (ID) associated with the third target device,

· a backhaul radio link control channel configuration, or

· a BAP layer configuration.

For example, the first device 110 may have previously selected the third target device for the first traffic and the fourth target device for the second traffic. For example, the IAB MIGRATION MANAGEMENT REQUEST message comprises the following information:

· Traffic Index #1, QoS=40 Mbps, DL TNL address = #A1 anchored at the fourth target device

· Traffic Index #2, QoS=60 Mbps, DL TNL address = #A2 anchored at the third target device.

Without the embodiments of the present disclosure, Traffic Index #2 will be rejected since the third target device only supports QoS=40 Mbps.

With the embodiments of the present disclosure, the first device 110 determines that the third target device can only support QoS=40 Mbps, and the fourth target device can support 60 Mbps. Thus, the first device 110 may use the third target device for the traffic identified by Traffic Index #1 and the fourth target device for the traffic identified by Traffic Index #2, and both Traffic Indexes are admitted. In such embodiments, at 318 in Fig. 3, the IAB MIGRATION MANAGEMENT RESONSE message may comprise Traffic Added List IE which further comprises the following information:

· Traffic Index #1, UL Routing ID including a BAP address of the third target device, new TNL address #A3 anchored at the third target device.

· Traffic Index #2, UL Routing ID including a BAP address of the fourth target device, new TNL address #A4 anchored at the fourth target device.

In a summary, such embodiments improve the migration success rate by allowing the target IAB-donor-CU to modify the previously selected IAB-donor-DU, and using multiple IAB-donor-DUs (e.g. the third target device and the fourth target device in above example) in the target topology.

Fig. 4 shows a flowchart of an example method 400 implemented at a first device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the first device 110 with respect to Fig. 1.

At block 410, the first device 110 receives, from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network. The first target device is associated with the first device, and the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network.

At block 420, the first device 110 selects, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device.

At block 430, the first device 110 transmits, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.

In some embodiments, the first device 110 receives, from the second device, the context of the traffic after receiving, from the second device, a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the first device 110 receives, from the second device, the context of the traffic in a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the traffic further comprises second traffic. The method 400 further comprises: selecting, based on the context, a third target device for the first traffic and a fourth target device for the second traffic, wherein the third and fourth target devices are associated with the first device; transmitting to the second device, second configuration information and third configuration information. The second configuration information is for communicating the first traffic between the second device and the third device via the third target device, and the third configuration information is for communicating the second traffic between the second device and the third device via the fourth target device.

In some embodiments, the first device 110 transmits, to the second device, the second configuration information and the third configuration information in a handover request acknowledge message or a secondary node addition request acknowledge message.

In some embodiments, the context comprises Quality of Service information associated with the traffic to be offloaded.

In some embodiments, the traffic comprises at least one of user plane traffic and control plane traffic.

In some embodiments, the context comprises QoS information associated with the user plane traffic.

In some embodiments, the method 400 further comprises: transmitting, to the third device, the first configuration information for communicating the first traffic between the second device and the third device via the second target device.

In some embodiments, the first configuration information comprises at least one of the following related to the second target device: a transport network layer address for the third device anchored at the second target device, an Internet Protocol version 6 flow label, a differentiated services code point, a backhaul adaptation protocol routing identifier associated with the second target device, a backhaul radio link control channel configuration; or a backhaul adaptation protocol layer configuration.

In some embodiments, the first device comprises a target IAB-donor-CU, the second device comprises a source IAB-donor-CU, the third device comprises an IAB node, and each of the first target device and the second target device comprises a target IAB-donor-DU.

In some embodiments, each of the third target device and the fourth target device comprises a target IAB-donor-DU.

Fig. 5 shows a flowchart of an example method 500 implemented at a second device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the second device 120 with respect to Fig. 1.

At block 510, the second device 120 transmits, to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network. The first target device is associated with the first device, and the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network.

At block 520, the second device 120 receives, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device.

At block 530, the second device 120 communicates the first traffic using the first configuration information.

In some embodiments, the second device 120 transmits, to the first device, the context of the traffic after transmitting, to the first device, a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the second device 120 transmits, to the first device, the context of the traffic in a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the traffic further comprises second traffic. In such embodiments, the method 500 further comprises: receiving from the first device second configuration information and third configuration information. The second configuration information is for communicating the first traffic between the second device and the third device via a third target device, and the third configuration information is for communicating the second traffic between the second device and the third device via a fourth target device. The third and fourth target devices are associated with the first device.

In some embodiments, the second device 120 receives, from the first device, the second configuration information and the third configuration information in a handover request acknowledge message or a secondary node addition request acknowledge message.

In some embodiments, the method 500 further comprises: transmitting, to the third device, an indication to apply the first configuration information for communicating the first traffic.

Fig. 6 shows a flowchart of an example method 600 implemented at a third device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the third device 130 with respect to Fig. 1.

At block 610, the third device 130 receives, from a first device or a second device in the radio access network, first configuration information for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network. The second target device is associated with the first device.

At block 620, the third device 130 communicates the first traffic using the first configuration information.

In some embodiments, the method 600 further comprises: receiving, from the second device, an indication to apply the first configuration information for communicating the first traffic.

In some example embodiments, a first apparatus in a radio access network capable of performing any of the method 400 (for example, the first device 110) may comprise means for performing the respective operations of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first device 110. In some example embodiments, the means may comprise a processor and a memory.

In some example embodiments, the first apparatus comprises: means for receiving, from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; means for selecting, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and means for transmitting, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.

In some embodiments, the means for receiving comprises means for receiving, from the second device, the context of the traffic after receiving, from the second device, a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the means for receiving comprises means for receiving, from the second device, the context of the traffic in a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the traffic further comprises second traffic. The first apparatus further comprises: means for selecting, based on the context, a third target device for the first traffic and a fourth target device for the second traffic, wherein the third and fourth target devices are associated with the first device; transmitting to the second device, second configuration information and third configuration information. The second configuration information is for communicating the first traffic between the second device and the third device via the third target device, and the third configuration information is for communicating the second traffic between the second device and the third device via the fourth target device.

In some embodiments, The first apparatus further comprises: means for transmitting, to the second device, the second configuration information and the third configuration information in a handover request acknowledge message or a secondary node addition request acknowledge message.

In some embodiments, the first apparatus further comprises: means for transmitting, to the third device, the first configuration information for communicating the first traffic between the second device and the third device via the second target device.

In some embodiments, the first apparatus comprises a target IAB-donor-CU, the second device comprises a source IAB-donor-CU, the third device comprises an IAB node, and each of the first target device and the second target device comprises a target IAB-donor-DU.

In some example embodiments, a second apparatus in a radio access network capable of performing any of the method 500 (for example, the second device 120) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second device 120. In some example embodiments, the means may comprise a processor and a memory.

In some example embodiments, the second apparatus comprises: means for transmitting, to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network; means for receiving, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device; and means for communicating the first traffic using the first configuration information.

In some embodiments, the means for transmitting comprises means for transmitting, to the first device, the context of the traffic after transmitting, to the first device, a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the means for transmitting comprises means for transmitting, to the first device, the context of the traffic in a handover request message or a secondary node addition request message for offloading the traffic.

In some embodiments, the traffic further comprises second traffic. In such embodiments, the second apparatus further comprises: means for receiving from the first device second configuration information and third configuration information. The second configuration information is for communicating the first traffic between the second device and the third device via a third target device, and the third configuration information is for communicating the second traffic between the second device and the third device via a fourth target device. The third and fourth target devices are associated with the first device.

In some embodiments, the second apparatus further comprises: means for receiving, from the first device, the second configuration information and the third configuration information in a handover request acknowledge message or a secondary node addition request acknowledge message.

In some embodiments, the first device comprises a target IAB-donor-CU, the second apparatus comprises a source IAB-donor-CU, the third device comprises an IAB node, and each of the first target device and the second target device comprises a target IAB-donor-DU.

In some embodiments, the second apparatus further comprises: means for transmitting, to the third device, an indication to apply the first configuration information for communicating the first traffic.

In some example embodiments, a third apparatus in a radio access network capable of performing any of the method 600 (for example, the third device 130) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The third apparatus may be implemented as or included in the third device 130. In some example embodiments, the means may comprise a processor and a memory.

In some example embodiments, the third apparatus comprises: means for receiving, from a first device in the radio access network, first configuration information for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device; means for communicating the first traffic using the first configuration information.

In some embodiments, the third apparatus further comprises: means for receiving, from the second device, an indication to apply the first configuration information for communicating the first traffic.

In some embodiments, the first device comprises a target IAB-donor-CU, the second device comprises a source IAB-donor-CU, the third apparatus comprises an IAB node, and each of the first target device and the second target device comprises a target IAB-donor-DU.

Fig. 7 is a simplified block diagram of a device 700 that is suitable for implementing example embodiments of the present disclosure. The device 700 may be provided to implement a communication device, for example, the first device 110, the second device 120, or the third device 130 as shown in Fig. 1. As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processor 710, and one or more communication modules 740 coupled to the processor 710.

The communication module 740 is for bidirectional communications. The communication module 740 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 740 may include at least one antenna.

The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

A computer program 730 includes computer executable instructions that could be executed by the associated processor 710. The program 730 may be stored in the memory, e.g., ROM 724. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

The example embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to Figs. 2 to 6. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. Fig. 8 shows an example of the computer readable medium 800 which may be in form of CD, DVD or other optical storage disk. The computer readable medium has the program 730 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above with reference to Figs. 2 to 6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

It should be appreciated that though some embodiments may be implemented by/at IAB nodes, solutions including methods and apparatus proposed in this disclosure could also be applied in other communication systems where similar technical problems exist. Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first device in a radio access network, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to:

receive, from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network;

select, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and

transmit, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.
The first device of claim 1, wherein the first device is caused to:

receive, from the second device, the context of the traffic after receiving, from the second device, a handover request message or a secondary node addition request message for offloading the traffic.
The first device of claim 1, wherein the first device is caused to:

receive, from the second device, the context of the traffic in a handover request message or a secondary node addition request message for offloading the traffic.
The first device of claim 3, wherein:

the traffic further comprises second traffic; and

the first device is further caused to:

select, based on the context, a third target device for the first traffic and a fourth target device for the second traffic, wherein the third and fourth target devices are associated with the first device;

transmit to the second device, second configuration information and third configuration information, wherein the second configuration information is for communicating the first traffic between the second device and the third device via the third target device, the third configuration information is for communicating the second traffic between the second device and the third device via the fourth target device.
The first device of claim 4, wherein the first device is caused to:

transmit, to the second device, the second configuration information and the third configuration information in a handover request acknowledge message or a secondary node addition request acknowledge message.
The first device of any of claims 1 to 5, wherein the context comprises Quality of Service information associated with the traffic.
The first device of any of claims 1 to 6, wherein the traffic comprises at least one of user plane traffic and control plane traffic.
The first device of claim 7, wherein the context comprises QoS information associated with the user plane traffic.
The first device of claim 1, wherein the first device is further caused to:

transmit, to the third device, the first configuration information for communicating the first traffic between the second device and the third device via the second target device.
The first device of any of claims 1 to 9, wherein the first configuration information comprises at least one of the following related to the second target device:

a transport network layer address for the third device anchored at the second target device,

an Internet Protocol version 6 flow label,

a differentiated services code point,

a backhaul adaptation protocol routing identifier associated with the second target device,

a backhaul radio link control channel configuration; or

a backhaul adaptation protocol layer configuration.
The first device of claim 1, wherein the first device comprises a target integrated access and backhaul donor central unit, IAB-donor-CU, the second device comprises a source IAB-donor-CU, the third device comprises an IAB node, and each of the first target device and the second target device comprises a target integrated access and backhaul donor distributed unit, IAB-donor-DU.
The first device of claim 4, wherein each of the third target device and the fourth target device comprises a target integrated access and backhaul donor distributed unit, IAB-donor-DU.
A second device in a radio access network, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to:

transmit, to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network;

receive, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device; and

communicate the first traffic using the first configuration information.
The second device of claim 13, wherein the second device is caused to:

transmit, to the first device, the context of the traffic after transmitting, to the first device, a handover request message or a secondary node addition request message for offloading the traffic.
The second device of claim 13, wherein the second device is caused to:

transmit, to the first device, the context of the traffic in a handover request message or a secondary node addition request message for offloading the traffic.
The second device of claim 15, wherein:

the traffic further comprises second traffic; and

the second device is further caused to

receive from the first device, second configuration information and third configuration information, wherein the second configuration information is for communicating the first traffic between the second device and the third device via a third target device, the third configuration information is for communicating the second traffic between the second device and the third device via a fourth target device, wherein the third and fourth target devices are associated with the first device.
The second device of claim 16, wherein the second device is caused to:

receive, from the first device, the second configuration information and the third configuration information in a handover request acknowledge message or a secondary node addition request acknowledge message.
The second device of any of claims 13 to 17, wherein the context comprises Quality of Service information associated with the traffic.
The second device of any of claims 13 to 18, wherein the traffic comprises at least one of user plane traffic and control plane traffic.
The second device of claim 19, wherein the context comprises QoS information associated with the user plane traffic.
The second device of any of claims 13 to 20, wherein the first configuration information comprises at least one of the following related to the second target device:

a transport network layer address for the third device anchored at the second target device,

an Internet Protocol version 6 flow label,

a differentiated services code point,

a backhaul adaptation protocol routing identifier associated with the second target device,

a backhaul radio link control channel configuration; or

a backhaul adaptation protocol layer configuration.
The second device of claim 13, wherein the first device comprises a target integrated access and backhaul donor central unit, IAB-donor-CU, the second device comprises a source IAB-donor-CU, the third device comprises an IAB node, and each of the first target device and the second target device comprises a target integrated access and backhaul donor distributed unit, IAB-donor-DU.
The second device of claim 16, wherein each of the third target device and the fourth target device comprises a target integrated access and backhaul donor distributed unit, IAB-donor-DU.
The second device of claim 13, wherein the second device is further caused to:

transmit, to the third device, an indication to apply the first configuration information for communicating the first traffic.
A third device in a radio access network, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to:

receive, from a first device or a second device in the radio access network, first configuration information for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device; and

communicate the first traffic using the first configuration information.
The third device of claim 25, wherein the third device is further caused to:

receive, from the second device, an indication to apply the first configuration information for communicating the first traffic.
The third device of any claims 25 to 26, wherein the first device comprises a target integrated access and backhaul donor central unit, IAB-donor-CU, the second device comprises a source IAB-donor-CU, the third device comprises an IAB node, and the second target device comprises a target integrated access and backhaul donor distributed unit, IAB-donor-DU.
A method, comprising:

receiving, at a first device in a radio access network from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network;

selecting, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and

transmitting, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.
A method, comprising:

transmitting, from a second device in a radio access network to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network;

receiving, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device; and

communicating the first traffic using the first configuration information.
A method, comprising:

receiving, at a third device in a radio access network from a first device or a second device in the radio access network, first configuration information to be used for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device;

communicating the first traffic using the first configuration information.
A first apparatus, comprising:

means for receiving, from a second device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network;

means for selecting, based on the context, a second target device for the first traffic, wherein the second target device is associated with the first device; and

means for transmitting, to the second device, first configuration information for communicating the first traffic between the second device and the third device via the second target device.
A second apparatus, comprising:

means for transmitting, to a first device in the radio access network, context of traffic to be offloaded via a first target device in the radio access network, wherein the first target device is associated with the first device, and wherein the traffic comprises first traffic to be communicated between the second device and a third device in the radio access network;

means for receiving, from the first device, first configuration information for communicating the first traffic between the second device and the third device via a second target device, wherein the second target device is associated with the first device; and

means for communicating the first traffic using the first configuration information.
A third apparatus, comprising:

means for receiving, from a first device or a second device in the radio access network, first configuration information for communicating first traffic between a second device in the radio access network and the third device in the radio access network via a second target device in the radio access network, wherein the second target device is associated with the first device;

means for communicating the first traffic using the first configuration information.
A computer readable medium comprising program instructions that, when executed by at least one processor, cause an apparatus to perform at least the method of claim 28.
A computer readable medium comprising program instructions that, when executed by at least one processor, cause an apparatus to perform at least the method of claim 29.
A computer readable medium comprising program instructions that, when executed by at least one processor, cause an apparatus to perform at least the method of claim 30.