INTER CENTRAL UNIT MIGRATION IN AN INTEGRATED ACCESS BACKHAUL NETWORK

TECHNICAL FIELD

The present application relates generally to an integrated access backhaul (IAB) network, and relates more particularly to inter-CU migration in such an IAB network.

BACKGROUND

A split radio network architecture splits radio network equipment (e.g., a base station) into a so-called central unit (CU) and one or more so-called distributed units (DUs). The central unit terminates higher layer and/or less time-critical protocols, such as the Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) protocols towards a wireless device. The central unit also controls the operations of the distributed unit(s). A distributed unit by contrast terminates lower layer and/or more time-critical protocols, such as the Radio Link Control (RLC), Medium Access Control (MAC), and physical layer protocols.

The split radio network architecture may be applied to an integrated access backhaul (IAB) where some radio resources are used for the access link to wireless devices and some radio resources are also used for the backhaul link between radio network equipment. Such IAB may be used for instance to connect small cells to the network, instead of requiring fiber connections to the many small cells. With IAB, one or more so-called IAB nodes may be chained underneath an IAB donor. Each IAB node holds a DU and a mobile termination (MT). Via the MT, the IAB node connects to an upstream IAB node or the IAB donor. Via the DU, the IAB node establishes RLC channels to user equipments (UEs) and to MTs of downstream IAB nodes. The IAB donor also holds a DU to support UEs and MTs of downstream IAB nodes. The IAB donor further holds a CU for the DUs of all IAB nodes and for its own DU.

The topology of the IAB nodes may be dynamically adapted, e.g., to account for changing channel or loading conditions on the wireless backhaul, integration of a new IAB node to the topology, or the like. IAB topology adaptation requires reconfiguring the endpoints of any transport layer tunnels or other connections associated with a migrating IAB node that hands over to a new serving IAB node. However, such reconfiguration proves challenging, especially in an inter-CU migration whereby the migrating IAB node will be served by a different donor CU than before the migration. Indeed, reconfiguration in such a scenario may threaten service interruption (due to lAB-node migration) and signaling load. Moreover, facilitating an inter-CU migration by sharing network topology, deployment information, configuration information, or other information between CUs poses a security or privacy risk, as well as undesirably increases signaling overhead and processing load.

SUMMARY

Some embodiments herein advantageously facilitate inter-CU migration (e.g., for load balancing) without requiring the sharing of network topology, deployment information, configuration information, or other information between CUs, at least to the same extent as in known approaches.

More particularly, embodiments herein include a method performed by an integrated access backhaul, IAB, node in an IAB network. The method comprises receiving, from a first donor central unit, CU, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU, and routing traffic using the mapping.

In some embodiments, the one or more first resources include one or more first addresses for the first wireless backhaul, and the one or more second resources include one or more second addresses for the second wireless backhaul. Additionally or alternatively, the one or more first resources include one or more first routing identities for the first wireless backhaul, and the one or more second resources include one or more second routing identities for the second wireless backhaul. Additionally or alternatively, the one or more first resources include one or more first channels for the first wireless backhaul, and the one or more second resources include one or more second channels for the second wireless backhaul. In one or more of these embodiments, the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and the one or more second addresses are one or more BAP addresses. Additionally or alternatively, the one or more first routing identities are one or more BAP routing identities, and the one or more second routing identities are one or more BAP routing identities. Additionally or alternatively, the one or more first channels are one or more Radio Link Control, RLC, channels, and the one or more second channels are one or more RLC channels.

In some embodiments, the first donor CU is in a first network and the second donor CU is in a second network.

In some embodiments, the one or more first resources are associated with or assigned to a first mobile termination protocol stack at the IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination protocol stack at the IAB node.

In some embodiments, the IAB node serves one or more child IAB nodes that are controlled by the first donor CU and that are respectively assigned the one or more first resources, wherein the one or more first resources are mapped to one or more different respective second resources.

In some embodiments, the IAB node is controlled by both the first donor CU and the second donor CU.

In some embodiments, receiving the mapping comprises receiving a table that indicates the mapping, wherein the table is a routing table or a translation table.

In some embodiments, receiving the mapping comprises receiving the mapping during, as part of, or in response to performing a reconfiguration procedure to establish a connection between the IAB node and the second donor CU.

In some embodiments, the method further comprises receiving, from a parent IAB node or from a second donor distributed unit, a packet using one of the one or more second resources, and mapping the second resource used to receive the packet to a first resource according to the received mapping. In this case, routing comprises routing the packet to a child IAB node or to a served user equipment using the mapped first resource.

In some embodiments, the method further comprises receiving, from a child IAB node or a served user equipment, a packet using one of the one or more first resources, and mapping the first resource used to receive the packet to a second resource according to the received mapping. In this case, routing comprises routing the packet to a parent IAB node or to a second donor distributed unit using the mapped second resource.

Other embodiments herein include a method performed by a first donor central unit, CU, in an integrated access backhaul, IAB, network. The method comprises transmitting, from the first donor CU to an IAB node, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU.

In some embodiments, the one or more first resources include one or more first addresses for the first wireless backhaul, and the one or more second resources include one or more second addresses for the second wireless backhaul. Additionally or alternatively, the one or more first resources include one or more first routing identities for the first wireless backhaul, and the one or more second resources include one or more second routing identities for the second wireless backhaul. Additionally or alternatively, the one or more first resources include one or more first channels for the first wireless backhaul, and the one or more second resources include one or more second channels for the second wireless backhaul. In one or more of these embodiments, the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and the one or more second addresses are one or more BAP addresses. Additionally or alternatively, the one or more first routing identities are one or more BAP routing identities, and the one or more second routing identities are one or more BAP routing identities. Additionally or alternatively the one or more first channels are one or more Radio Link Control, RLC, channels, and the one or more second channels are one or more RLC channels.

In some embodiments, the first donor CU is in a first network and the second donor CU is in a second network.

In some embodiments, the one or more first resources are associated with or assigned to a first mobile termination protocol stack at the IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination protocol stack at the IAB node.

In some embodiments, the IAB node serves one or more child IAB nodes that are controlled by the first donor CU and that are respectively assigned the one or more first resources, wherein the one or more first resources are mapped to one or more different respective second resources.

In some embodiments, the IAB node is controlled by both the first donor CU and the second donor CU.

In some embodiments, transmitting the mapping comprises transmitting a table that indicates the mapping, wherein the table is a routing table or a translation table.

In some embodiments, transmitting the mapping comprises transmitting the mapping during, as part of, or in response to performing a reconfiguration procedure to establish a connection between the IAB node and the second donor CU.

In some embodiments, based on the mapping transmitting at least some traffic via the first wireless backhaul and at least some traffic via the second wireless backhaul. Additionally or alternatively, based on the mapping receiving at least some traffic via the first wireless backhaul and at least some traffic via the second wireless backhaul.

In some embodiments, the method further comprises routing traffic using the mapping.

In some embodiments, the method further comprises transmitting, to the IAB node, one or more rules according to which the IAB node is to decide whether to transmit an uplink packet via the first wireless backhaul or the second wireless backhaul.

In some embodiments, the method further comprises transmitting, to the second donor CU, a request for a number of second resources that are to be allocated for the second wireless backhaul controlled by the second donor CU and that are to be associated with the first donor CU, receiving a response that indicates the one or more second resources allocated in accordance with the request, and generating the mapping based on the response.

In some embodiments, the method further comprises transmitting, to the second donor CU, an indication of an amount of traffic to be offloaded from the first donor CU or the first wireless backhaul to the second donor CU or the second wireless backhaul.

Other embodiments herein include a method performed by a second donor central unit, CU, in an integrated access backhaul, IAB, network. The method comprises receiving, from a first donor CU, a request for a number of second resources that are to be allocated for a second wireless backhaul controlled by the second donor CU and that are to be associated with the first donor CU, and transmitting a response that indicates one or more second resources allocated in accordance with the request.

In some embodiments, the method further comprises receiving, from the first donor CU, an indication of an amount of traffic to be offloaded from the first donor CU or a first wireless backhaul to the second donor CU or the second wireless backhaul.

Other embodiments herein include a method performed by a second donor distributed unit, DU, in an integrated access backhaul, IAB, network. The method comprises receiving a mapping between one or more first resources for a first wireless backhaul controlled by a first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU, and routing traffic using the mapping.

In some embodiments, the one or more first resources include one or more first addresses for the first wireless backhaul, and the one or more second resources include one or more second addresses for the second wireless backhaul. Additionally or alternatively, the one or more first resources include one or more first routing identities for the first wireless backhaul, and the one or more second resources include one or more second routing identities for the second wireless backhaul. Additionally or alternatively, the one or more first resources include one or more first channels for the first wireless backhaul, and the one or more second resources include one or more second channels for the second wireless backhaul. In one or more of these embodiments, the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and the one or more second addresses are one or more BAP addresses. Additionally or alternatively, the one or more first routing identities are one or more BAP routing identities, and the one or more second routing identities are one or more BAP routing identities. Additionally or alternatively, the one or more first channels are one or more Radio Link Control, RLC, channels, and the one or more second channels are one or more RLC channels.

In some embodiments, the first donor CU is in a first network and the second donor CU is in a second network.

In some embodiments, the one or more first resources are associated with or assigned to a first mobile termination protocol stack at an IAB node, and the one or more second resources are associated with or assigned to a second mobile termination protocol stack at the IAB node.

In some embodiments, an IAB node serves one or more child IAB nodes that are controlled by the first donor CU and that are respectively assigned the one or more first resources, and the one or more first resources are mapped to one or more different respective second resources.

In some embodiments, an IAB node is controlled by both the first donor CU and the second donor CU.

In some embodiments, receiving the mapping comprises receiving a table that indicates the mapping, wherein the table is a routing table or a translation table.

In some embodiments, receiving the mapping comprises receiving the mapping during, as part of, or in response to performing a reconfiguration procedure to establish a connection between an IAB node and the second donor CU.

In some embodiments, the method further comprises receiving, from a child IAB node or a served user equipment, a packet using one of the one or more second resources, mapping the second resource used to receive the packet to a first resource according to the received mapping, and routing the packet towards the first donor CU using the mapped first resource.

Other embodiments herein include an IAB node configured for use in an IAB network. The IAB node is configured to receive, from a first donor central unit, CU, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU, and route traffic using the mapping

In some embodiments, the IAB node is configured to perform the steps described above for an IAB node.

Other embodiments herein include a first donor central unit, CU, configured for use in an integrated access backhaul, IAB, network. The first donor CU is configured to transmit, from the first donor CU to an IAB node, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU.

In some embodiments, the first donor CU is configured to perform the steps described above for a first donor CU.

Other embodiments herein include a second donor central unit, CU, configured for use in an integrated access backhaul, IAB, network. The second donor CU is configured to receive, from a first donor CU, a request for a number of second resources that are to be allocated for a second wireless backhaul controlled by the second donor CU and that are to be associated with the first donor CU, and transmit a response that indicates one or more second resources allocated in accordance with the request.

In some embodiments, the second donor CU is configured to receive, from the first donor CU, an indication of an amount of traffic to be offloaded from the first donor CU or a first wireless backhaul to the second donor CU or the second wireless backhaul.

Other embodiments herein include a second donor distributed unit, DU, configured for use in an integrated access backhaul, IAB, network. The second donor CU is configured toreceive a mapping between one or more first resources for a first wireless backhaul controlled by a first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU, and route traffic using the mapping.

In some embodiments, the second donor CU is configured to perform the steps described above for a second donor CU.

Other embodiments herein include a computer program comprising instructions which, when executed by at least one processor of an IAB node, causes the IAB node to perform the steps described above for an IAB node. Other embodiments herein include computer program comprising instructions which, when executed by at least one processor of a donor CU, causes the donor CU to perform the steps described above for a first donor CU. Other embodiments herein include a computer program comprising instructions which, when executed by at least one processor of a donor DU, causes the donor DU to perform the steps described above for a second donor CU. In one or more of these embodiments, a carrier containing the computer program described above is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. Other embodiments herein include an IAB node configured for use in an IAB network. The IAB node comprises communication circuitry and processing circuitry. The processing circuitry is configured to receive, from a first donor central unit, CU, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU, and route traffic using the mapping.

In some embodiments, the processing circuitry is configured to perform the steps described above for an IAB node.

Other embodiments herein include a first donor central unit, CU, configured for use in an integrated access backhaul, IAB, network. The first donor CU comprises communication circuitry and processing circuitry. The processing circuitry is configured to transmit, from the first donor CU to an IAB node, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU.

In some embodiments, the processing circuitry is configured to perform the steps described above for a first donor CU.

Other embodiments herein include a second donor central unit, CU, configured for use in an integrated access backhaul, IAB, network. The second donor CU comprises communication circuitry and processing circuitry. The processing circuitry is configured to receive, from a first donor CU, a request for a number of second resources that are to be allocated for a second wireless backhaul controlled by the second donor CU and that are to be associated with the first donor CU, and transmit a response that indicates one or more second resources allocated in accordance with the request.

In some embodiments, the processing circuitry is configured to receive, from the first donor CU, an indication of an amount of traffic to be offloaded from the first donor CU or a first wireless backhaul to the second donor CU or the second wireless backhaul.

Other embodiments herein include a second donor distributed unit, DU, configured for use in an integrated access backhaul, IAB, network. The second donor DU comprises communication circuitry and processing circuitry. The processing circuitry is configured to receive a mapping between one or more first resources for a first wireless backhaul controlled by a first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU, and route traffic using the mapping.

In some embodiments, the processing circuitry is configured to perform the steps described above for a second donor DU.

Of course, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram of an IAB node connectable to two different donor CUs according to some embodiments.

Figure 22 is a logic flow diagram of a method performed by an IAB node according to some embodiments.

Figure 3 is a logic flow diagram of a method performed by a first donor CU according to some embodiments.

Figure 4 is a logic flow diagram of a method performed by a second donor CU according to some embodiments.

Figure 5 is a logic flow diagram of a method performed by a second donor DU according to some embodiments.

Figure 6 is a block diagram of a network node configurable as an IAB node, a donor CU, or a donor DU according to some embodiments.

Figure 7 is a block diagram of IAB in standalone mode according to some embodiments.

Figure 8 is a block diagram of a baseline user plane stack for IAB according to some embodiments.

Figure 9 is a block diagram of a baseline control plane protocol stack for IAB according to some embodiments.

Figure 10 is a block diagram of a functional view of the BAP sublayer according to some embodiments.

Figure 11 is a block diagram of lAB-node migration cases according to some embodiments.

Figure 12 is a call flow diagram of a topology adaptation procedure, where the target parent node uses a different lAB-donor-DU than the source parent node, according to some embodiments.

Figure 13 is a block diagram of an IAB node with multiple Mobile Terminations (MTs) according to some embodiments.

Figure 14 is a block diagram of an IAB node with multiple Mobile Terminations (MTs) with respective protocol stacks according to some embodiments.

Figure 15 is a call flow diagram of a reconfiguration procedure according to some embodiments.

Figure 16 is a block diagram of mapping between BAP addresses according to some embodiments.

Figure 17 is a block diagram of a wireless communication network according to some embodiments.

Figure 18 is a block diagram of a user equipment according to some embodiments.

Figure 19 is a block diagram of a virtualization environment according to some embodiments. Figure 20 is a block diagram of a communication network with a host computer according to some embodiments.

Figure 21 is a block diagram of a host computer according to some embodiments.

Figure 22 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 23 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 24 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 25 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

DETAILED DESCRIPTION

Figure 1 shows an integrated access backhaul (IAB) node 10 configured for use in an IAB network according to some embodiments. As least initially, the IAB node 10 is under the control of donor central unit (CU) 12-1 . The IAB node 10 in this regard is connected to the donor CU 12-1 via a parent IAB node or a donor distributed unit (DU) 14-1. The IAB node 10 accesses this parent IAB node or donor DU 14-1 over a wireless backhaul 16-1 controlled by donor CU 12-1 . One or more resources 18-1 are associated with this wireless backhaul 16-1 . The resource(s) 18-1 may include for instance (i) one or more addresses, e.g., Backhaul Adaptation Protocol (BAP) addresses; (ii) one or more routing identities, e.g., BAP routing identities; and/or (iii) one or more channels, e.g., Radio Link Control (RLC) channels.

Figure 1 also shows another donor CU 12-2 to which the IAB node 10 may migrate, e.g., via so-called inter-CU migration. In some embodiments, donor CU 12-2 is in a different network than donor CU 12-1. Regardless, migration of the IAB node 10 to donor CU 12-2 would mean that the IAB node connects to donor CU 12-2 via another parent IAB node or a donor DU 14-2. The IAB node 10 would access this other parent IAB node or donor DU 14-2 over a different wireless backhaul 16-2 controlled by donor CU 12-2. One or more resources 18-2 are associated this other wireless backhaul 16-2, e.g., as one or more addresses, one or more routing identities, and/or one or more channels. In the context of migration from donor CU 12-1 to donor CU 12-2, donor CU 12-1 may be referred to as the source donor CU 12-1 and donor CU 12-2 may be referred to as the target donor CU 12-2.

According to some embodiments, donor CU 12-1 transmits a mapping 20 to the IAB node 10, e.g., as indicated or otherwise embodied in a routing table or a translation table. The mapping 20 is a mapping between the resource(s) 18-1 for the wireless backhaul 16-1 controlled by donor CU 12-1 and the resource(s) 18-2 for the wireless backhaul 16-2 controlled by donor CU 12-2. The mapping may for instance comprise a mapping between one or more BAP addresses for wireless backhaul 16-1 and one or more BAP addresses for wireless backhaul 16-2, a mapping between one or more BAP routing identities for wireless backhaul 16- 1 and one or more BAP identities for wireless backhaul 16-2, and/or a mapping between one or more RLC channels for wireless backhaul 16-1 and one or more RLC channels for wireless backhaul 16-2.

In some embodiments, the mapping 20 is usable by the IAB node 10 for routing traffic, e.g., in the form of packets. For example, in some embodiments, the IAB node 10 receives traffic from child node(s) 22 of the IAB node 10 or from user equipment(s) 24 served by the IAB node 10, and uses the mapping 20 to determine whether to route the traffic over wireless backhaul 16-1 or over wireless backhaul 16-2. Alternatively or additionally, in some embodiments, the IAB node 10 receives traffic over wireless backhaul 16-1 or over wireless backhaul 16-2, and uses the mapping 20 to determine to which child node 22 or user equipment 24 to route the traffic.

Routing traffic using the mapping 20 may, for example, facilitate traffic routing after migration of the IAB node 10 to donor CU 12-2. In some embodiments, for instance, different resource(s) 18-1 for wireless backhaul 16-1 are respectively assigned to different child node(s) 22 and/or user equipment(s) 24, e.g., for effectively multiplexing traffic for different child node(s) 22 and/or user equipment(s) 24 on wireless backhaul 16-1 . To account for migration to donor CU 12-2, though, the mapping 20 maps those resource(s) 18-1 for wireless backhaul 16-1 to respective resource(s) 18-2 for wireless backhaul 16-2. The IAB node 10 may then use the mapping 20 to effectively translate between resources 18-1 for wireless backhaul 16-1 and resources 18-2 for wireless backhaul 16-2, as needed to determine how to route traffic even after migration to donor CU 12-2. Moreover, since the IAB node 10 itself performs the routing based on the mapping 20, the IAB node 10 need not reveal information about its child node(s) 22 and/or UE(s) 24 to other nodes. In these and other embodiments, then, the mapping 20 may advantageously facilitate inter-CU migration (e.g., for load balancing) without requiring the sharing of network topology, deployment information, configuration information, or other information between CUs 12-1 , 12-2, at least to the same extent as in known approaches.

More particularly, in some embodiments, the IAB node 10 may receive, from a parent IAB node or from a donor DU 14-2, a packet using one of the resource(s) 18-2 for wireless backhaul 16-2. The IAB node 10 may map the second resource 18-2 used to receive the packet to one of the resource(s) 18-1 according to the mapping 20. The IAB node 10 may then route the packet to a child IAB node 22 or to a served user equipment 24 using the mapped resource 18-1.

Alternatively or additionally, the IAB node 10 may receive, from a child IAB node 22 or a served user equipment 24, a packet using one of the resource(s) 18-1 for wireless backhaul 16- 1 . The IAB node 10 may map the resource 18-1 used to receive the packet to one of the resource(s) 18-2 for wireless backhaul 16-2 according to the mapping 20. The IAB node 10 may then route the packet to a parent IAB node or to a donor DU 14-2 using the mapped resource 18-2. Figure 1 also shows that, in some embodiments, donor CU 12-1 generates the mapping 20 based on information received from donor CU 12-2 about the resource(s) 18-2 for wireless backhaul 16-2. In particular, as shown, donor CU 12-1 transmits a request 30 to donor CU 12-2. The request 30 is a request for a number of resource(s) 18-2 that are to be allocated for wireless backhaul 16-2 controlled by donor CU 12-2 and that are to be associated with donor CU 12-1 . Donor CU 12-2 correspondingly transmits a response 32 to donor CU 12-2, indicating the resource(s) 18-2 allocated in accordance with the request 30. Based on this response 32, donor CU 12-2 generates the mapping 20.

Note that, in some embodiments, traffic that is associated with donor CU 12-1 but that is nonetheless routed via wireless backhaul 16-2 may traverse donor CU 12-2. In other embodiments, though, such traffic may bypass donor CU 12-2. As shown, for instance, in some embodiments, donor CU 12-1 may transmit the mapping 20 to parent IAB node or donor DU 14-2, in which case the parent IAB node or donor DU 14-2 may use the mapping to route traffic similarly as described above. Routing traffic in this way may mean that the traffic can be routed directly to or from donor CU 12-1 without traversing donor CU 12-2.

Figure 22 correspondingly depicts a method performed by an IAB node 10 in an IAB network in accordance with particular embodiments. The method includes receiving, from a first donor CU 12-1 , a mapping 20 between one or more first resources 18-1 for a first wireless backhaul 16-1 controlled by the first donor CU 12-1 and one or more second resources 18-2 for a second wireless backhaul 16-2 controlled by a second donor CU 12-2 (Block 2200). The method in some embodiments also includes routing traffic using the mapping 20 (Block 210).

In some embodiments, the one or more first resources 18-1 include one or more first addresses for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second addresses for the second wireless backhaul 16-2. Additionally or alternatively, the one or more first resources 18-1 include one or more first routing identities for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second routing identities for the second wireless backhaul 16-2. Additionally or alternatively, the one or more first resources 18-1 include one or more first channels for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second channels for the second wireless backhaul 16-2. In one or more of these embodiments, the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and the one or more second addresses are one or more BAP addresses. Additionally or alternatively, the one or more first routing identities are one or more BAP routing identities, and the one or more second routing identities are one or more BAP routing identities. Additionally or alternatively, the one or more first channels are one or more Radio Link Control, RLC, channels, and the one or more second channels are one or more RLC channels.

In some embodiments, the first donor CU 12-1 is in a first network and the second donor

CU 12-2 is in a second network. In some embodiments, the one or more first resources 18-1 are associated with or assigned to a first mobile termination protocol stack at the IAB node 10, and wherein the one or more second resources 18-2 are associated with or assigned to a second mobile termination protocol stack at the IAB node 10.

In some embodiments, the IAB node 10 serves one or more child IAB nodes 22 that are controlled by the first donor CU 12-1 and that are respectively assigned the one or more first resources 18-1 , wherein the one or more first resources 18-1 are mapped to one or more different respective second resources 18-2.

In some embodiments, the IAB node 10 is controlled by both the first donor CU 12-1 and the second donor CU 12-2.

In some embodiments, receiving the mapping 20 comprises receiving a table that indicates the mapping 20, wherein the table is a routing table or a translation table.

In some embodiments, receiving the mapping 20 comprises receiving the mapping 20 during, as part of, or in response to performing a reconfiguration procedure to establish a connection between the IAB node 10 and the second donor CU 12-2.

In some embodiments, the method further comprises receiving, from a parent IAB node or from a second donor distributed unit 14-2, a packet using one of the one or more second resources 18-2, and mapping the second resource 18-2 used to receive the packet to a first resource 18-1 according to the received mapping 20. In this case, routing comprises routing the packet to a child IAB node 22 or to a served user equipment 24 using the mapped first resource 18-1.

In some embodiments, the method further comprises receiving, from a child IAB node 22 or a served user equipment 24, a packet using one of the one or more first resources 18-1 , and mapping the first resource 18-1 used to receive the packet to a second resource 18-2 according to the received mapping 20. In this case, routing comprises routing the packet to a parent IAB node or to a second donor distributed unit 14-2 using the mapped second resource 18-2.

Figure 3 depicts a method performed by a first donor CU 12-1 in an integrated access backhaul, IAB, network in accordance with other particular embodiments. The method in some embodiments includes transmitting, from the first donor CU 12-1 to an IAB node 10, a mapping 20 between one or more first resources 18-1 for a first wireless backhaul 16-1 controlled by the first donor CU 12-1 and one or more second resources 18-2 for a second wireless backhaul 16- 2 controlled by a second donor CU 12-2 (Block 315).

The method may alternatively or additionally include transmitting, to the second donor CU 12-2, a request 30 for a number of second resources 18-2 that are to be allocated for the second wireless backhaul 16-2 controlled by the second donor CU 12-2 and that are to be associated with the first donor CU 12-1 (Block 300). In such a case, the method may also comprise receiving a response 32 that indicates the one or more second resources 18-2 allocated in accordance with the request 30 (Block 305) and generating the mapping 20 based on the response 32 (Block 310).

In some embodiments, the method also comprises routing traffic using the mapping 20 (Block 315).

In some embodiments, the one or more first resources 18-1 include one or more first addresses for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second addresses for the second wireless backhaul 16-2. Additionally or alternatively, the one or more first resources 18-1 include one or more first routing identities for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second routing identities for the second wireless backhaul 16-2. Additionally or alternatively, the one or more first resources 18-1 include one or more first channels for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second channels for the second wireless backhaul 16-2. In one or more of these embodiments, the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and the one or more second addresses are one or more BAP addresses. Additionally or alternatively, the one or more first routing identities are one or more BAP routing identities, and the one or more second routing identities are one or more BAP routing identities. Additionally or alternatively the one or more first channels are one or more Radio Link Control, RLC, channels, and the one or more second channels are one or more RLC channels.

In some embodiments, the first donor CU 12-1 is in a first network and the second donor CU 12-2 is in a second network.

In some embodiments, the one or more first resources 18-1 are associated with or assigned to a first mobile termination protocol stack at the IAB node 10, and wherein the one or more second resources 18-2 are associated with or assigned to a second mobile termination protocol stack at the IAB node 10.

In some embodiments, the IAB node 10 serves one or more child IAB nodes 22 that are controlled by the first donor CU 12-1 and that are respectively assigned the one or more first resources 18-1 , wherein the one or more first resources 18-1 are mapped to one or more different respective second resources 18-2.

In some embodiments, the IAB node 10 is controlled by both the first donor CU 12-1 and the second donor CU 12-2.

In some embodiments, transmitting the mapping 20 comprises transmitting a table that indicates the mapping 20, wherein the table is a routing table or a translation table.

In some embodiments, transmitting the mapping 20 comprises transmitting the mapping 20 during, as part of, or in response to performing a reconfiguration procedure to establish a connection between the IAB node 10 and the second donor CU 12-2.

In some embodiments, based on the mapping 20 transmitting at least some traffic via the first wireless backhaul 16-1 and at least some traffic via the second wireless backhaul 16-2. Additionally or alternatively, based on the mapping 20 receiving at least some traffic via the first wireless backhaul 16-1 and at least some traffic via the second wireless backhaul 16-2.

In some embodiments, the method further comprises transmitting, to the IAB node 10, one or more rules according to which the IAB node 10 is to decide whether to transmit an uplink packet via the first wireless backhaul 16-1 or the second wireless backhaul 16-2.

In some embodiments, the method further comprises transmitting, to the second donor CU 12-2, an indication of an amount of traffic to be offloaded from the first donor CU 12-1 or the first wireless backhaul 16-1 to the second donor CU 12-2 or the second wireless backhaul 16-2.

Figure 4 depicts a method performed by a second donor CU 12-2 in an integrated access backhaul, IAB, network in accordance with other particular embodiments. The method in some embodiments includes receiving, from a first donor CU 12-1 , a request 30 for a number of second resources 18-2 that are to be allocated for a second wireless backhaul 16-2 controlled by the second donor CU 12-2 and that are to be associated with the first donor CU 12-1 (Block 400). The method may also comprise transmitting a response 32 that indicates one or more second resources 18-2 allocated in accordance with the request 30 (Block 405).

In some embodiments, the method further comprises receiving, from the first donor CU 12-1 , an indication of an amount of traffic to be offloaded from the first donor CU 12-1 or a first wireless backhaul 16-1 to the second donor CU 12-2 or the second wireless backhaul 16-2.

Figure 5 shows a method performed by a second donor DU 14-2 in an integrated access backhaul, IAB, network according to some embodiments. The method comprises receiving a mapping 20 between one or more first resources 18-1 for a first wireless backhaul 16-1 controlled by a first donor CU 12-1 and one or more second resources 18-2 for a second wireless backhaul 16-2 controlled by a second donor CU 12-2 (Block 500). The method further comprises routing traffic using the mapping 20 (Block 510).

In some embodiments, the one or more first resources 18-1 include one or more first addresses for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second addresses for the second wireless backhaul 16-2. Additionally or alternatively, the one or more first resources 18-1 include one or more first routing identities for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second routing identities for the second wireless backhaul 16-2. Additionally or alternatively, the one or more first resources 18-1 include one or more first channels for the first wireless backhaul 16-1 , and the one or more second resources 18-2 include one or more second channels for the second wireless backhaul 16-2. In one or more of these embodiments, the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and the one or more second addresses are one or more BAP addresses. Additionally or alternatively, the one or more first routing identities are one or more BAP routing identities, and the one or more second routing identities are one or more BAP routing identities. Additionally or alternatively, the one or more first channels are one or more Radio Link Control, RLC, channels, and the one or more second channels are one or more RLC channels. In some embodiments, the first donor CU 12-1 is in a first network and the second donor CU 12-2 is in a second network.

In some embodiments, the one or more first resources 18-1 are associated with or assigned to a first mobile termination protocol stack at an IAB node 10, and the one or more second resources 18-2 are associated with or assigned to a second mobile termination protocol stack at the IAB node 10.

In some embodiments, an IAB node 10 serves one or more child IAB nodes 22 that are controlled by the first donor CU 12-1 and that are respectively assigned the one or more first resources 18-1 , and the one or more first resources 18-1 are mapped to one or more different respective second resources 18-2.

In some embodiments, an IAB node 10 is controlled by both the first donor CU 12-1 and the second donor CU 12-2.

In some embodiments, receiving the mapping 20 comprises receiving a table that indicates the mapping 20, wherein the table is a routing table or a translation table.

In some embodiments, receiving the mapping 20 comprises receiving the mapping 20 during, as part of, or in response to performing a reconfiguration procedure to establish a connection between an IAB node 10 and the second donor CU 12-2.

In some embodiments, the method further comprises receiving, from a child IAB node 22 or a served user equipment 24, a packet using one of the one or more second resources 18-2, mapping the second resource 18-2 used to receive the packet to a first resource 18-1 according to the received mapping 20, and routing the packet towards the first donor CU 12-1 using the mapped first resource 18-1.

Embodiments herein also include corresponding apparatuses. Embodiments herein for instance include an IAB node 10 configured to perform any of the steps of any of the embodiments described above for the IAB node 10.

Embodiments also include an IAB node 10 comprising processing circuitry and power supply circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the IAB node 10. The power supply circuitry is configured to supply power to the IAB node 10.

Embodiments further include an IAB node 10 comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the IAB node 10. In some embodiments, the IAB node 10 further comprises communication circuitry.

Embodiments further include an IAB node 10 comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the IAB node 10 is configured to perform any of the steps of any of the embodiments described above for the IAB node 10.

Embodiments herein also include a donor CU 12-1 or 12-2 configured to perform any of the steps of any of the embodiments described above for the first donor CU 12-1 or the second donor CU 12-2.

Embodiments also include a donor CU 12-1 or 12-2 comprising processing circuitry and power supply circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the first donor CU 12-1 or the second donor CU 12-2. The power supply circuitry is configured to supply power to the donor CU 12-1 or 12-2.

Embodiments further include a donor CU 12-1 or 12-2 comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the first donor CU 12-1 or the second donor CU 12-2. In some embodiments, the donor CU 12-1 or 12-2 further comprises communication circuitry.

Embodiments further include a donor CU 12-1 or 12-2 comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the donor CU 12-1 or 12-2 is configured to perform any of the steps of any of the embodiments described above for the first donor CU 12-1 or the second donor CU 12-2.

Embodiments herein also include a donor DU 14-2 configured to perform any of the steps of any of the embodiments described above for the donor DU 14-2.

Embodiments also include a donor DU 14-2 comprising processing circuitry and power supply circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the donor DU 14-2. The power supply circuitry is configured to supply power to the donor DU 14-2.

Embodiments further include a donor DU 14-2 comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the donor DU 14-2. In some embodiments, the donor DU 14-2 further comprises communication circuitry.

Embodiments further include a donor DU 14-2 comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the donor DU 14-2 is configured to perform any of the steps of any of the embodiments described above for the donor DU 14-2.

More particularly, the apparatuses described above may perform the methods herein and any other processing by implementing any functional means, modules, units, or circuitry. In one embodiment, for example, the apparatuses comprise respective circuits or circuitry configured to perform the steps shown in the method figures. The circuits or circuitry in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory. For instance, the circuitry may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In embodiments that employ memory, the memory stores program code that, when executed by the one or more processors, carries out the techniques described herein.

Figure 6 for example illustrates a network node 600 as implemented in accordance with one or more embodiments. The network node 600 may exemplify an IAB node 10, a donor CU 12-1 or 12-2, or a donor DU 14-2. As shown, the network node 600 includes processing circuitry 610 and communication circuitry 620. The communication circuitry 620 (e.g., radio circuitry) is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. Such communication may occur via one or more antennas that are either internal or external to the wireless device 600. The processing circuitry 610 is configured to perform processing described above, e.g., in Figure 2, 3, 4, or 5, such as by executing instructions stored in memory 630. The processing circuitry 610 in this regard may implement certain functional means, units, or modules.

Those skilled in the art will also appreciate that embodiments herein further include corresponding computer programs.

A computer program comprises instructions which, when executed on at least one processor of an apparatus, cause the apparatus to carry out any of the respective processing described above. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above.

Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

In this regard, embodiments herein also include a computer program product stored on a non-transitory computer readable (storage or recording) medium and comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform as described above.

Embodiments further include a computer program product comprising program code portions for performing the steps of any of the embodiments herein when the computer program product is executed by a computing device. This computer program product may be stored on a computer readable recording medium.

Additional embodiments will now be described. At least some of these embodiments may be described as applicable in certain contexts and/or wireless network types for illustrative purposes, but the embodiments are similarly applicable in other contexts and/or wireless network types not explicitly described.

Some embodiments herein are applicable to Integrated Access Backhaul (IAB) networks as being standardized by 3GPP for New Radio (NR) in Release 16 (RP-182882). In this regard, the usage of short range mmWave spectrum in NR creates a need for densified deployment with multi-hop backhauling. However, optical fiber to every base station will be too costly and sometimes not even possible (e.g. historical sites). The main IAB principle is the use of wireless links for the backhaul (instead of fiber) to enable flexible and very dense deployment of cells without the need for densifying the transport network. Use case scenarios for IAB can include coverage extension, and deployment of a massive number of small cells and fixed wireless access (FWA) (e.g. to residential/office buildings). The larger bandwidth available for NR in mmWave spectrum provides opportunity for self-backhauling, without limiting the spectrum to be used for the access links. On top of that, the inherent multi-beam and multiple-input multipleoutput (MIMO) support in NR reduces cross-link interference between backhaul and access links, allowing higher densification.

Some embodiments leverage the Central Unit (CU) I Distributed Unit (DU) split architecture of NR, where the IAB node will be hosting a DU part that is controlled by a central unit (CU). The IAB nodes also have a Mobile Termination (MT) part that they use to communicate with their parent nodes.

The specifications for IAB strive to reuse existing functions and interfaces defined in NR. In particular, MT, gNB-DU, gNB-CU, User Plane Function (UPF), Access and Mobility management Function (AMF) and Session Management Function (SMF) as well as the corresponding interfaces NR Uu (between MT and gNB), F1 , NG, X2 and N4 are used as baseline for the IAB architectures.

The Mobile-Termination (MT) function has been defined as a component of the IAB node. MT is referred to herein as a function residing on an lAB-node that terminates the radio interface layers of the backhaul Uu interface toward the lAB-donor or other lAB-nodes.

Figure 7 shows a reference diagram for IAB in standalone mode, e.g., as specified by TR 38.874. The IAB network contains one lAB-donor and multiple lAB-nodes. The lAB-donor is treated as a single logical node that comprises a set of functions such as gNB-DU, gNB- CU-CP, gNB-CU-UP and potentially other functions. In a deployment, the lAB-donor can be split according to these functions, which can all be either collocated or non-collocated as allowed by 3GPP NG-RAN architecture. lAB-related aspects may arise when such split is exercised. Also, some of the functions presently associated with the lAB-donor may eventually be moved outside of the donor in case it becomes evident that they do not perform lAB-specific tasks. The baseline user plane and control plane protocol stacks for IAB are shown in Figures 8 and 9, respectively. As shown, the chosen protocol stacks reuse the current CU-DU split specification in rel-15, where the full user plane F1-U (GTP-U/UDP/IP) is terminated at the IAB node (like a normal DU) and the full control plane F1-C (F1-AP/SCTP/IP) is also terminated at the IAB node (like a normal DU). Here, GTP-U is the Generic Tunnelling Protocol (GPT) User plane, UDP is the User Datagram Protoocl (UDP), IP is the Internet Protocol (IP), F1-AP is the F1 Application Protocol (AP), and SCTP is the Stream Control Transmission Protocol (SCTP). In the above cases, Network Domain Security (NDS) has been employed to protect both UP and CP traffic (IPsec in the case of UP, and Datagram Transport Layer Security, DTLS, in the case of CP). IPsec could also be used for the control plane (CP) protection instead of DTLS (in this case no DTLS layer would be used).

A protocol layer called Backhaul Adaptation Protocol (BAP) in the IAB nodes and the IAB donor is used for routing of packets to the appropriate downstream/upstream node and also mapping the UE bearer data to the proper backhaul RLC channel (and also between ingress and egress backhaul RLC channels in intermediate IAB nodes) to satisfy the end to end quality of service (QoS) requirements of bearers.

BAP entities

On the lAB-node, the BAP sublayer contains one BAP entity at the MT function and a separate collocated BAP entity at the DU function. On the lAB-donor-DU, the BAP sublayer contains only one BAP entity. Each BAP entity has a transmitting part and a receiving part. The transmitting part of the BAP entity has a corresponding receiving part of a BAP entity at the lAB-node or lAB-donor-DU across the backhaul link.

Figure 10 shows one example of the functional view of the BAP sublayer. This functional view should not restrict implementation. The figure is based on the radio interface protocol architecture defined in TS 38.300. In the example of Figure 10, the receiving part on the BAP entity delivers BAP protocol data units (PDUs) to the transmitting part on the collocated BAP entity. Alternatively, the receiving part may deliver BAP service data units (SDUs) to the collocated transmitting part. When passing BAP SDUs, the receiving part removes the BAP header and the transmitting part adds the BAP header with the same BAP routing ID as carried on the BAP PDU header prior to removal. Passing BAP SDUs in this manner is therefore functionally equivalent to passing BAP PDUs, in implementation.

Figure 11 shows an example of some possible lAB-node migration cases listed in the order of complexity and more details as follows: Intra-CU Case (A): In this case the lAB-node (e) along with it serving UEs is moved to a new parent node (lAB-node (b)) under the same donor-DU (1). The successful intradonor DU migration requires establishing UE context setup for the lAB-node (e) MT in the DU of the new parent node (lAB-node (b)), updating routing tables of IAB nodes along the path to lAB-node (e) and allocating resources on the new path. The IP address for lAB-node (e) will not change, while the F1-U tunnel/connection between donor-CU (1) and lAB-node (e) DU will be redirected through lAB-node (b).

Intra-CU Case (B): The procedural requirements/complexity of this case is the same as that of Case (A). Also, since the new lAB-donor DU (i.e. DU2) is connected to the same L2 network, the lAB-node (e) can use the same IP address under the new donor DU. However, the new donor DU (i.e. DU2) will need to inform the network using lAB-node (e) L2 address in order to get/keep the same IP address for lAB-node (e) by employing some mechanism such as Address Resolution Protocol (ARP).

Intra-CU Case (C): This case is more complex than Case (A) as it also needs allocation of new IP address for lAB-node (e). In case, IPsec is used for securing the F1-U tunnel/connection between the Donor-CU (1) and lAB-node (e) DU, then it might be possible to use existing IP address along the path segment between the Donor-CU (1) and SeGW, and new IP address for the IPsec tunnel between SeGW and lAB-node (e) DU.

Inter-CU Case (D): This is the most complicated case in terms of procedural requirements. Note that 3GPP Rel-16 has heretofore standardized the procedure only for intra-CU migration, which is described below.

Intra-CU topology adaptation procedure

During the intra-CU topology adaptation, both the source and the target parent node are served by the same lAB-donor-CU. The target parent node may use a different lAB-donor- DU than the source parent node. The source path may further have common nodes with the target path. Figure 12 shows an example of the topology adaptation procedure, where the target parent node uses a different lAB-donor-DU than the source parent node.

1 . The migrating IAB- MT sends a Measurement Report message to the source parent node gNB-DU. This report is based on a Measurement Configuration the migrating IAB-MT received from the lAB-donor-CU before.

2. The source parent node gNB-DU sends an UL RRC MESSAGE TRANSFER message to the lAB-donor-CU to convey the received Measurement Report.

3. The lAB-donor-CU sends a UE CONTEXT SETUP REQUEST message to the target parent node gNB-DU to create the UE context for the migrating IAB-MT and setup one or more bearers. These bearers are used by the migrating IAB- MT for its own data and signalling traffic.

4. The target parent node gNB-DU responds to the lAB-donor-CU with a UE CONTEXT SETUP RESPONSE message. 5. The lAB-donor-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source parent node gNB-DU, which includes a generated RRCReconfiguration message. The Transmission Action Indicator in the UE CONTEXT MODIFICATION REQUEST message indicates to stop the data transmission to the migrating lAB-node.

6. The source parent node gNB-DU forwards the received RRCReconfiguration message to the migrating IAB-MT.

7. The source parent node gNB-DU responds to the lAB-donor-CU with the UE CONTEXT MODIFICATION RESPONSE message.

8. A Random Access procedure is performed at the target parent node gNB-DU.

9. The migrating IAB-MT responds to the target parent node gNB-DU with an RRCReconfigurationComplete message.

10. The target parent node gNB-DU sends an UL RRC MESSAGE TRANSFER message to the lAB-donor-CU to convey the received RRCReconfigurationComplete message. Also, uplink packets can be sent from the migrating IAB-MT, which are forwarded to the lAB-donor- CU through the target parent node gNB-DU. These DL and UL packets belong to the MT’s own signalling and data traffic.

11 . The lAB-donor-CU configures BH RLC channels and BAP-layer route entries on the target path between migrating lAB-node and target lAB-donor-DU. This step also includes allocation of TNL address(es) that is (are) routable via the target lAB-donor-DU. These configurations may be performed at an earlier stage, e.g. right after step 3. The new TNL address(es) is (are) included in the RRCReconfiguration message at step 5.

12. All F1-U tunnels and F1-C are switched to use the migrating lAB-node’s new TNL address(es).

13. The lAB-donor-CU sends a UE CONTEXT RELEASE COMMAND message to the source parent node gNB-DU.

14. The source parent node gNB-DU releases the migrating lAB-MT’s context and responds the lAB-donor-CU with a UE CONTEXT RELEASE COMPLETE message.

15. The lAB-donor-CU releases BH RLC channels and BAP routing entries on the source path. The migrating lAB-node may further release the TNL address(es) it used on the source path.

NOTE: In case that the source route and target route have common nodes, the BH RLC channels and BAP routing entries of those nodes may not need to be released in Step 15. NOTE: Steps 11 , 12 and 15 also have to be performed for the migrating lAB-node’s descendant nodes, as follows:

- The descendant nodes must also switch to new Transport Network Layer (TNL) addresses that are anchored in the target lAB-donor-DU. The lAB-donor-CU may send these addresses to the descendant nodes and release the old addresses via corresponding RRC signalling. If needed, the lAB-donor-CU configures BH RLC channels, BAP-layer route entries on the target path for the descendant nodes and the BH RLC Channel mappings on the descendant nodes in the same manner as described for the migrating lAB-node in step 11.

- The descendant nodes switch their F1-U and F1-C tunnels to new TNL addresses that are anchored at the new lAB-donor-DU, in the same manner as described for the migrating lAB-node in step 12.

Based on implementation, these steps can be performed after or in parallel with the handover of the migrating lAB-node. In Rel-16, in-flight packets in UL direction that were dropped during the migration procedure may not be recoverable.

NOTE: In upstream direction, in-flight packets between the source parent node and the lAB- donor-CU can be delivered even after the target path is established.

NOTE: On-going downlink data in the source path may be discarded up to implementation. NOTE: lAB-donor-CU can determine the unsuccessfully transmitted downlink data over the backhaul link by implementation.

Inter-CU migration

As indicated above, Release 16 did not specify inter-CU migration, i.e., an IAB node under the control of a first CU is handed over to a second CU that would take control of the IAB node. It is the same concept as for mobile UEs, where a UE moves from one gNB (first CU) to a second gNB (second CU). In Release 17, 3GPP will specify the aforementioned use case, i.e., inter-CU migration. Currently, 3GPP understands that radio link failure (RLF) is the main use case for inter-CU migration, in which case an IAB node loses connection to the first CU due to radio link failure between the IAB node and its parent IAB or donor DU. If the IAB node follows legacy behavior, it should perform an RRC Re-establishment to recover from the RLF.

The common understanding in 3GPP for solving the above problem is to enhance the RRC Re-establishment procedure or introduce a similar procedure as the conditional handover. In both of these solutions, the user context is passed to the second CU, meaning that the IAB node, its children IAB nodes (directly or indirectly connected), and the UEs served by it may need to be reconfigured. This type of solution typically implies that the user plane and, potentially, the control plane will experience a break as the whole context is moved from CU1 to CU2.

A multi-MT solution (3GPP R3-205224) would not only solve the RLF problem but would allow load balancing (see Figure 13). A solution based on multi-MT would be a more flexible and useful approach than a solution that only solves error cases, which are typically rare in a planned network. In Figure 13, IAB3 has a multi-MT where MTs are connected to different parent IAB nodes, while these parent IAB nodes are connected to (or controlled by) different CUs. Some embodiments herein facilitate inter-CU migration and load balancing without requiring that the first CU shares with the second CU the context of the affected IAB nodes and UEs, the corresponding backhaul configuration, and topology information. This means that the first CU does not need to share either partly or in whole, the network architecture, deployment, and configuration of the network under its control with the second CU.

This is advantageous because migrating the IAB nodes and UEs contexts from one CU to another CU (i.e. applying the legacy, handover-like approach) would otherwise imply: (1) a large signaling overhead (due to sending of context, backhaul RLC channels and topology information over the Xn interface); (2) a large processing load (where the second CU needs to process the received information (listed in 1)) and incorporate the new nodes and UEs into its network); and (3) exposing the first CU’s network architecture to the second CU. Besides, the above may also lead to service interruption, as the reconfiguration of the affected IAB nodes and UEs will take time.

Further, CUs are typically not dimensioned to carry their own traffic plus the neighbors’ traffic. It also needs to be considered that IAB nodes aggregate data from other IAB nodes and UEs. Thus, the aggregated traffic can be huge. Moving the UE and IAB node contexts, backhaul RLC channels, and topology information from one CU to another CU would require high capacity in the CUs as well as high processing capacity to handle the signaling chain and reestablishing the connections for many IAB nodes and UEs. Some embodiments may thereby avoid these shortcomings.

In this regard, some embodiments minimize or at least reduce the signaling and processing load between the two CUs and avoid sharing the network architecture and configuration of the first CU/network with a second CU/network. In other words, inter-CU migration according to some embodiments results in limited signaling and minimum capacity requirements for the CUs that might carry a part of (or whole) the traffic of a first CU.

More particularly, some embodiments ensure that, when doing load sharing, the source (first) CU does not need to expose the topology under it or the nodes which it supports. The source (first) CU will request from a second CU to establish a connection towards a certain IAB node (already served by the first CU) to offload traffic carried in the first network. This may be up to 100% of the traffic, for example, when there is a radio link failure. The first CU will request the second CU to return a set of parameters (e.g. a set of BAP addresses and/or BAP routing IDs) which will be later used by the IAB node from which traffic is being off-loaded to route the data coming from/to the first network and the second network.

Generally, some embodiments allow connecting an IAB node (e.g. IAB3) in a first network to a second parent IAB node or Donor DU in a second network connected to a second CU. In this procedure, the network topology and configuration of the first network, and UE contexts are not shared. This is achieved by the first CU requesting from the second CU a set of BAP addresses, BAP routing IDs, and BH RLC Channels, and providing the IAB3 with a translation table so that IAB3 can map the e.g. BAP address and BAP routing ID of a packet received via the second network to the BAP address and BAP routing ID of destination in the first network.

Certain embodiments may provide one or more of the following technical advantage(s). Some embodiments enable load balancing between a first CU and number of other CUs without sharing the network architecture, deployment and configuration of the first CU’s network. It also allows to recover quicker from failures, such as radio link failure.

1. The use of Multiple MT architecture for load balancing

An IAB node supporting multiple MTs is shown in Figure 13. In this context, IAB3, whose MT is initially served by donor-CU1 via parent node IAB2, gets connected to yet another parent node IAB1 (served by donor-CU2) by a second MT in order to transport part of its traffic (originally carried by IAB3) through this new link towards IAB1 . CU2 will only forward part of the data/traffic that CU1 wants to transmit to an IAB node or UEs under IAB3. The remaining part of the data/traffic intended to terminate at or go via IAB3 can be transmitted via the initial/original link (i.e., link between IAB3 and IAB2), through “Donor DU1”.

This type of architecture and operation may be established when the radio resources in a part or branch of the network will be exhausted due to high traffic load. Under this situation, there is a need to offload part of the traffic to another part or branch of the IAB network to prevent and avoid the negative impacts of the high traffic load over the service provided to UEs by the network nodes.

2. Multiple MT description

One IAB node is configured with two or more protocol stacks, wherein one protocol stack includes one or more of the following protocol layers e.g. RRC, PDCP, BAP, RLC, MAC, PHY, wherein each protocol stack is associated to a separate logical MT. In one method, a logical MT corresponds to a physical MT. In another method, one or more logical MTs may be associated to the same physical MT and identified by separate software architectures. The one or more logical MTs are collocated in the same IAB node which also consists of a DU part.

The above allows transmitting to and receiving data from two or more independent parent IAB nodes (i.e., IAB2 and IAB1). For the case of two parent nodes, this is depicted in another example scenario shown in Figure 14, where IAB3 MT functionality has two protocol stacks, one used for backhaul link with IAB2 _C ui and the other for the backhaul link with IAB1 _C u2.

A first logical MT of an IAB node is configured and controlled by a first CU while the second logical MT is configured and controlled by a second CU, which may be the same or different than the CU that controls the DU part of the concerned IAB node. For example, in Figure 14, one of the protocol stacks, pertaining to one of logical MTs, e.g. MTCU1 ,is configured by CU1 , while a second protocol stack (pertaining to the second logical MT,) e.g. MTCU2, is configured by CU2. The control of the DU part in IAB3CU1 is under the donor-CU1.

The IAB configured with multiple MTs receives the uplink rules to decide which traffic is routed via the first network (i.e. CU1) and which part of the traffic is router via the second network (i.e. CU 2). In the downlink, it is the CU1 entity that decides which traffic is transmitted over the first network and which traffic is transmitted over the second network.

3. Setup and configuration of multiple MTs for inter-CU load balancing

According to some embodiments, a reconfiguration procedure is initiated by a first CU with the purpose to create and maintain a second connection for a specific IAB node (with the capability of supporting multiple logical MTs), i.e. a connection between the IAB node and a second CU, using a logical MT different than the logical MT used by the IAB node to connect to the first CU.

This reconfiguration procedure is triggered by one or more events pertaining to a first logical MT included in the said IAB node, or to a parent IAB node connected to the said first logical MT, or to one or more backhaul links on the path between the IAB donor node of the concerned IAB node and the said first logical MT, or to the donor IAB node to which the first logical MT is connected. These events could also be triggered by operation and maintenance (CAM).

The reconfiguration procedure implies enabling/disabling the connection of the second logical MT to a parent node different than the parent node serving the first logical MT. The reconfiguration procedure implies also providing a different configuration, e.g. addition/removal of some of the backhaul channels, modification of QoS and/or priority of existing backhaul channels, to the first, to the second logical MT, or to both logical MTs.

The abovementioned one or more events may comprise:

• A measurement result on a neighbouring cell/frequency, wherein the measurement may be performed by the first logical MT or second logical MT

• Traffic load/congestion at one backhaul link between the parent node and the said MT

• Load balancing triggered by the donor CU of the said MT, e.g. as a result of one or more backhaul links on the path between the donor CU and the said MT experiencing congestion

• RLF of the SpCell that is configured to the said MT

• Reception of RLF indication from the parent node, e.g. following RLF of the SpCell that is configured to the parent IAB node of the said MT

• Indication from the QAM signaling to donor IAB node, e.g. donor CU, of the said logical MT, to enable/disable/reconfigure the second logical MT

• Fulfillment of any other criteria preconfigured in a network node e.g. at the said MT’s IAB node, donor CU, OAM, e.g. triggering of load balancing at certain preconfigured times of day (traffic peak hours, large gatherings etc.).

The reconfiguration procedure would be as shown in Figure 15. Take Figure 15 as an exampleError! Reference source not found., where IAB3 exemplifies an IAB node 10 performing the method of Figure 2, with a first wireless backhaul controlled by source Donor CU1 and a second wireless backhaul controlled by target Donor CU2. In this example, then, source Donor CU1 exemplifies a donor CU 12-1 performing the method of Figure 3, and target donor CU2 exemplifies a donor CU 12-2 performing the method of Figure 4. In any event, the reconfiguration procedure in Figure 15 is triggered by a measurement report, i.e. by the radio link conditions reported by IAB3 or IAB2 to source Donor CU1. Hence, step 1 and step 2 shown above are optional.

If the Donor CU initiates a reconfiguration to establish a second connection towards a specific IAB node with a multi logical MT capability, the source Donor CU1 will send an Xn signaling message to the target Donor CU2 for setting up backhaul RLC channels towards IAB3 and allocating BAP addresses and/or BAP routing IDs. The source Donor CU1 will request the number of BAP addresses and/or BAP routing IDs for DL, for the UL, or for both, to be allocated to the IAB3 by the target Donor CU2. In this request, the Donor CU1 may also provide an indication of the amount of traffic that may be offloaded towards CU2. This request is an example of the request 30 in Block 300 of Figure 3.

The target Donor CU2 will assign a set of BAP addresses and corresponding BAP routing IDs to IAB3, whereas these BAP addresses and BAP routing IDs are unique among the BAP addresses and/or BAP routing IDs assigned by the CU2 to other destination IAB nodes served by CU2. The number of assigned BAP addresses and BAP routing IDs can be the same or less than the number of BAP addresses and BAP routing IDs requested by the CU1 . CU2 may also indicate whether it can accept the requested amount of traffic to be offloaded. If CU2 rejects it, it could also indicate to CU1 a second value for the amount of traffic it may carry from CU1. For example, it can be less in case some of the backhaul RLC channels, and hence IAB destinations, are rejected by CU2 following admission control criteria. The Donor CU2 will then send a response message to source Donor CU1 containing the set of assigned BAP addresses and possible BAP routing IDs to be used by CU1 when transmitting packets to IAB3 via CU2. There may be several messages between CU1 and CU2 to negotiate and re-negotiate the configuration. The response message by the target Donor CU2 can either be sent before or after RRC Reconfiguration is completed. This response is an example of the response 32 in Block 305 of Figure 3.

In some embodiments, in order to ensure the proper use of BAP addresses and BAP routing IDs assigned by the CU2 to IAB3, the CU2 indicates to the CU1 additional information pertaining to the BAP addresses and BAP routing IDs assigned by the CU2. As a non-limiting set of examples, the CU2 indicates, per assigned BAP address and BAP routing ID the available traffic capacity and/or the QoS and/or priority of BH RLC channels pertaining to each assigned BAP routing ID, whether the BAP routing ID pertains to N:1 or 1 :1 mapping etc. Furthermore, for the communication between CU1 and CU2 described in the above paragraph, either existing Xn signaling (e.g., HANDOVER REQUEST, HANDOVER REQUEST ACKNOWLEDGE, etc.) can be enhanced by adding new lEs or new Xn signaling messages can be defined.

NOTE: A Backhaul Access Protocol (BAP) routing ID consists of a BAP address and a path ID.

Next, the target Donor CU2 will perform a set of actions (either in parallel, in sequence, or concurrently), such as creating new mapping entries in the BAP layer of the target Donor DU2 (mapping between DSCP/flow label field/IP addresses and BAP addresses and BAP routing IDs assigned to IAB3), updating the routing tables of IAB1 , establishing new 1 :1 or/and N:1 BH RLC channels (if needed) over the backhaul links between target Donor DU2 and IAB1 , and between IAB1 and IAB3. For this purpose, additional lEs will be required in the F1 and RRC signaling between the target Donor CU2 and the DU and MT functionality of each intermediate IAB node, respectively (i.e., Donor DU1 and IAB1). The BAP layer at the Donor DU2 may be allocated with one or more BAP addresses to be used in the uplink by the second logical MT of the IAB node, IAB3. These BAP addresses will be used by Donor DU2 to identify the BAP packets to be routed towards CU1. Additionally, other fields such as “BAP routing ID” could be used in combination with the BAP address for the same purpose, or to provide a specific QoS treatment.

The target Donor CU2 will prepare an RRC Reconfiguration message to configure the second protocol stack (i.e., IAB3 MT _C u2), i.e. the second logical MT, which will be passed to source Donor CU1 and then CU1 will transmit it to IAB3. Such message transmitted by the CU1 to IAB3 may contain an identity or index of the second logical MT to which the RRC Reconfiguration is applied, e.g. the ID of the IAB3 MT _C u2, or a flag indicating that the RRC Reconfiguration applies to any other logical MT different from the first logical MT. In such latter case (i.e. a flag indicating that the message applies to another MT), it is the IAB3 that determines which logical MT is to connect to the CU2, e.g. the MT that is currently in IDLE or INACTIVE mode and not currently connected to any parent node or donor node, or the MT that is more capable in terms of TX/RX chains, or the MT that has better coverage with the parent IAB node to which it should connect, i.e. IAB1. Alternatively, the CU1 may explicitly indicate which MT is to connect to CU2. This indication may be sent to the MT that is to move to CU2 or to another MT of the same IAB node.

When IAB3 receives the configuration, the second logical MT (i.e., IAB3 MTCU2) will start a random access towards IAB1CU2 and will send the RRC Reconfiguration complete message to CU2. This RRC Reconfiguration message may also include information for the first logical MT and, possibly, it could also contain information affecting the DU. This message could potentially carry, for instance, the new routing tables for IAB3, and the mapping between DL BAP addresses and BAP routing IDs mapped to the second logical MT and the DL BAP addresses and BAP routing IDs to reach UEs under IAB3 or other IAB nodes under IAB3. The second logical MT will terminate all the DL BAP addresses and BAP routing IDs which the first CU requested from the second CU (or all the DL BAP addresses and BAP routing IDs the second CU allocated and indicated to the first CU).

When the RRC Reconfiguration Complete message is received by CU2, CU2 will inform CU1 that the procedure has been completed and now it is possible to route traffic between CU1 and its controlled nodes (i.e., IAB3) and UEs via CU2, or directly between CU1 and Donor DU2 and further on (while circumventing the CU2).

CU1 will eventually configure the IAB3 with the DL/UL new or updated routing tables, load balancing rules, and other relevant information for IAB3 to redirect a portion of the traffic via IAB2CU1 or via IAB1CU2. The routing tables should also contain information about how to map the BAP addresses and BAP routing IDs assigned to the second logical MT to the BAP addresses and BAP routing IDs of the internal network (controlled by CU1). Similarly, in the uplink, the routing tables should contain information about the traffic which should be routed via CU2 and the corresponding BAP address(es) and BAP routing ID(s). The routing tables here are an example of the mapping 20 discussed with regard to Block 200 in Figure 2 and Block 315 in Figure 3.

The IAB3 now has two configured MT stacks, i.e. two configured logical MTs, one for the backhaul link with IAB2 (under CU1 control) and another for the backhaul link with IAB1 (under CU2 control), while the IAB3 DU is still under source Donor CU1 control. The next step is to update the F1 configuration (especially the signaling for routing and backhaul RLC channel mapping) of the IAB3 DU so that in UL the IAB3 can perform load balancing by forwarding some of the traffic to the BAP layer of the first logical collocated MT (under CU1 control) and other traffic to the BAP layer of the second logical collocated MT (under CU2 control). Similarly, for the DL, the IAB3 has to determine from the BAP address and BAP routing ID of a packet received from the first logical MT or second logical MT whether such packet has reached its final destination or if it has to be routed to a child node.

In order to realize the above, methods are needed for the IAB3 to select for a given packet the proper egress link both in upstream and downstream, and to possibly modify the BAP header of the packet to ensure relaying in the proper paths at child or parent nodes. For example, in the downlink, packets which are to be routed through the same node or that are destinated to the same node may have different BAP destination addresses and BAP routing IDs, due to the fact that they are received by the concerned IAB node, i.e. IAB3, from different parent nodes controlled by different CUs, which in turn may have assigned different BAP addresses and BAP routing IDs for the same IAB node, as per the previous step. Such routing is an example of the routing in Block 210 in Figure 2.

Hence, some embodiments imply the source Donor CU1 to configure the concerned IAB node, i.e. IAB3, with a “BAP address and BAP routing ID translation” for some of the BAP addresses and BAP routing IDs assigned to the IAB nodes underneath IAB3 in the network topology. For example, such BAP address and BAP routing ID translation may consist of a list of BAP addresses and BAP routing IDs containing a mapping between the BAP addresses and BAP routing IDs assigned by the CU2 in previous steps and the BAP addresses assigned by the CU1 . In some embodiments, such BAP address translation list may also contain the path ID and the next hop BAP address to be applied to that specific destination assigned by the CU2. In another case, the BAP address and BAP routing ID translation list contains a mapping between the BAP addresses and BAP routing IDs assigned by the CU2 and the BAP addresses and BAP routing IDs as assigned by the CU1

Figure 16 exemplifies a simple case based on BAP addresses only (for simplicity of the figure - please note that the full-fledged case implies the use of BAP routing IDs, which consist of BAP address and path ID). In this example, the CU2 provided 4 BAP addresses for the second logical MT. Each IAB node has a BAP address allocated by CU1. IAB3 will contain a BAP address translation table in which will identify. A packet arriving to the second logical MT will have one BAP addresses from the set of BAP addresses allocated by CU2. When the said packet is received, IAB3 will perform a translation to know the corresponding BAP address in the first network under CU1 . If a packet with BAP address “BAP_3 IABCU2” is received, the translation table will return that this packet should be routed to the BAP address “BAP_5 IABCU1”. The DU in IAB3 can then change the corresponding BAP address so the packet can reach its destination.

(in the text below, the full-fledged (i.e. BAP routing ID) case is considered again)

The source Donor CU1 will inform the IAB3 DU about the DL and UL BAP mapping to translate the BAP addresses and BAP routing IDs and backhaul bearers established via IAB1CU2 to the internal BAP addresses and BAP routing IDs and backhaul bearers to reach other nodes and UEs under the control of CU1 .

To summarize, some embodiments are based on assigning multiple BAP addresses and BAP routing IDs will perform the following actions/tasks for transferring the DL traffic to the children nodes and UEs of IAB3 via CU2:

For IAB3, CU1 requests from CU2, via Xn signaling, a number of DL BAP addresses and BAP routing IDs and one or more UL BAP addresses and BAP routing IDs. Typically, one DL BAP address and BAP routing ID for each child node of IAB3 and one DL BAP address and BAP routing ID for each MT of IAB3. For UL, at least one BAP address and BAP routing ID for the Donor DU2.

CU2 will prepare an RRC configuration message to configure the second logical MT. This message is passed to CU1 which sends it to IAB3. This message may also contain configuration information for the first logical MT and even the DU in said IAB.

For CU2, all these BAP addresses terminate in the second logical MT, i.e. the IAB3_MT (controlled by CU2).

CU1 creates a mapping, i.e. the said “BAP address and BAP routing ID translation”, between the BAP addresses and routing IDs that it has assigned to the IAB nodes and the BAP addresses and routing IDs provided by CU2 (i.e. addresses under CU2 control/domain).

CU1 will signal this “BAP address and BAP routing ID translation” to IAB3, i.e. the IAB DU hosting the second logical MT, via F1 signaling or to an MT of the IAB3 via RRC signaling.

When CU1 sends a packet via CU2, it will indicate at least one of the CU2 BAP addresses to be used for the packet in the BAP header that is supposed to be assembled by the Donor DU2. The BAP routing ID to be used to traverse the network under CU2 may be also indicated by CU1 ; however, if it is not, the Donor DU2 will attach it based on other relevant information provided by CU1 about the said packet, or based on a configuration already agreed between CU1 and CU2.

When the packet arrives to the concerned IAB node, i.e. IAB3, the IAB node will inspect the packet header and check the BAP address and BAP routing ID of the destination node. If the BAP address and BAP routing ID is one the BAP addresses and BAP routing IDs assigned by the CU2 in previous steps, and if the packet was received by the second logical MT, the IAB node applies the “BAP address and BAP routing ID translation” and select the corresponding BAP address and BAP routing ID assigned by CU1 for that destination node, as well as the proper next hop according to the “BAP address and BAP routing ID translation”. The IAB3 DU will then select the next hop and replace the BAP address and the path ID (which together form the BAP routing ID) in the BAP header with the one assigned by CU1 according to the “BAP address and BAP routing ID translation”, and will deliver the packet to the lower layers for forwarding the packet via appropriate egress link and BH RLC channel.

For the uplink (UL), the donor CU1 may configure a second BAP translation including the mapping between certain BH channels and BAP routing/path ID as configured by the donor CU1 , and the BAP address and BAP routing/path ID as indicated by the donor CU2 to CU1 in previous steps.

According to some embodiments, the following procedure will be followed by IAB3 to perform traffic forwarding in the UL direction:

IAB3 decides based on predetermined rules (configured by Donor CU1) whether a certain packet should be transmitted over the backhaul link with the parent node IAB2 (under CU1 control) or the link with parent node IAB1 (under CU2 control). For example, the donor CU1 may configure IAB3 with the set of BH channels to be routed towards the CU2 or with the percentage of traffic associated to one BH channel that should be routed to CU2. In another example, the donor CU1 may configure IAB3 with one or more BAP routing IDs, so that the IAB3 will route the received packets in the upstream having those BAP routing IDs in the BAP header towards CU2.

In case a packet has to be routed to CU2, IAB3 DU updates the BAP address, and possibly the path ID of the packet according to the predetermined rules, and to the said second “BAP translation” list. Then, based on the next hop derived from the routing table, it forwards the packet to the appropriate protocol stack (e.g., second logical MT)

The IAB MT protocol stack checks the routing and backhaul RLC channel mapping tables and then delivers the packet towards the correct egress link and backhaul RLC channel.

When the Donor DU2 receives a packet with a BAP address and BAP routing ID allocated to carry traffic to CU1 , the Donor DU2 will re-route this data towards CU1 via CU2 or directly to CU1 (circumventing CU2).

In other embodiment, instead of assigning multiple BAP addresses and BAP routing IDs to IAB3 where each BAP address is used to uniquely indicate traffic for each child IAB node (underneath IAB3) of IAB3, different backhaul RLC channels will be configured on the link between the IAB3 MT (under CU2 control) and IAB1. In this case, each backhaul RLC channel will carry traffic for one pre-specified child IAB node and the BH RLC CH ID of the channel will enable IAB3 DU to perform proper DL forwarding. The main difference between this approach (i.e., based on backhaul RLC channel) and the one (based on multiple BAP addresses and BAP routing IDs) described above is given below:

Only 1 BAP address and BAP routing ID is requested (by CU1) and assigned (by CU2) to IAB3.

CU1 requests from CU2 a certain number of backhaul RLC channels, where the channel ID (instead of BAP address and BAP routing ID used in the first embodiment) will be used to identify traffic for an IAB node under the CU1 control.

Once CU2 responds/sends to CU1 the assigned/allocated backhaul RLC channel list, CU1 will create a mapping between BAP addresses and BAP routing IDs it has assigned to the IAB nodes underneath IAB3 and the backhaul RLC channels provided by CU2 that are established over the link between IAB3 MT (under CU2 control) and IAB1 . In this case, when travelling through the portion of the network under the control of CU2 (from IAB3 upstream), UL packets are assigned a default UL BAP routing ID from the CU2 domain, as per configuration from CU2. In the DL, the number of different DL BAP addresses and/or BAP routing IDs to be used for the offloaded DL traffic should be equal to the number of different IAB nodes under the IAB3 that are subject to traffic offloading (one BAP addresses and/or BAP routing ID per destination IAB node under IAB3).CU1 will send this mapping information to IAB3 DU via F1 signaling or to an MT of the IAB3 via RRC signaling.

IAB3 will use this mapping information for performing proper routing both in the UL and DL as described above in steps e) and f) for the multiple BAP address/routing ID approach explained above.

In the downlink, when CU1 sends a packet via CU2, CU1 will indicate the CU2 BAP address to reach the second logical MT in IAB3 and the backhaul RLC in which the packet needs to arrive to the second logical MT in IAB3. Alternatively, the BAP routing is ID to be used. The Donor DU2 will attach the corresponding fields in the BAP header.

Apart from the load balancing case, some embodiments can alternatively or additionally be employed for RLF. This could be a specific rule or trigger configured by CU1 in IAB3. For example, if the backhaul link between IAB3 MT (under CU1 control) and IAB2 fails, IAB3 will re- route/redirect the packets (initially intended for backhaul link towards IAB2) via IAB3 MT (under CU2 control) by updating the BAP address carried in the packet header. Another use case can be temporary inter-CU IAB node mobility, where the IAB node will temporarily migrate from the area under CU1 into the area under CU2 and then return to the area under CU1 (for example an IAB node installed in an airport shuttle that is constantly commuting between airport terminals at regular time intervals).

Some embodiments can be implemented in a cloud environment.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in Figure 17. For simplicity, the wireless network of Figure 17 only depicts network 1706, network nodes 1760 and 1760b, and WDs 1710, 1710b, and 1710c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node 1760 and wireless device (WD) 1710 are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Narrowband Internet of Things (NB-loT), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network 1706 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

Network node 1760 and WD 1710 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Yet further examples of network nodes include multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

In Figure 17, network node 1760 includes processing circuitry 1770, device readable medium 1780, interface 1790, auxiliary equipment 1784, power source 1786, power circuitry 1787, and antenna 1762. Although network node 1760 illustrated in the example wireless network of Figure 17 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node 1760 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 1780 may comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node 1760 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1760 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeB’s. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1760 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 1780 for the different RATs) and some components may be reused (e.g., the same antenna 1762 may be shared by the RATs). Network node 1760 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1760, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1760.

Processing circuitry 1770 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry 1770 may include processing information obtained by processing circuitry 1770 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Processing circuitry 1770 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 1760 components, such as device readable medium 1780, network node 1760 functionality. For example, processing circuitry 1770 may execute instructions stored in device readable medium 1780 or in memory within processing circuitry 1770. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry 1770 may include a system on a chip (SOC). In some embodiments, processing circuitry 1770 may include one or more of radio frequency (RF) transceiver circuitry 1772 and baseband processing circuitry 1774. In some embodiments, radio frequency (RF) transceiver circuitry 1772 and baseband processing circuitry 1774 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1772 and baseband processing circuitry 1774 may be on the same chip or set of chips, boards, or units In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry 1770 executing instructions stored on device readable medium 1780 or memory within processing circuitry 1770. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1770 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1770 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1770 alone or to other components of network node 1760, but are enjoyed by network node 1760 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1780 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1770. Device readable medium 1780 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1770 and, utilized by network node 1760. Device readable medium 1780 may be used to store any calculations made by processing circuitry 1770 and/or any data received via interface 1790. In some embodiments, processing circuitry 1770 and device readable medium 1780 may be considered to be integrated.

Interface 1790 is used in the wired or wireless communication of signalling and/or data between network node 1760, network 1706, and/or WDs 1710. As illustrated, interface 1790 comprises port(s)/terminal(s) 1794 to send and receive data, for example to and from network 1706 over a wired connection. Interface 1790 also includes radio front end circuitry 1792 that may be coupled to, or in certain embodiments a part of, antenna 1762. Radio front end circuitry 1792 comprises filters 1798 and amplifiers 1796. Radio front end circuitry 1792 may be connected to antenna 1762 and processing circuitry 1770. Radio front end circuitry may be configured to condition signals communicated between antenna 1762 and processing circuitry 1770. Radio front end circuitry 1792 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1792 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1798 and/or amplifiers 1796. The radio signal may then be transmitted via antenna 1762. Similarly, when receiving data, antenna 1762 may collect radio signals which are then converted into digital data by radio front end circuitry 1792. The digital data may be passed to processing circuitry 1770. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1760 may not include separate radio front end circuitry 1792, instead, processing circuitry 1770 may comprise radio front end circuitry and may be connected to antenna 1762 without separate radio front end circuitry 1792. Similarly, in some embodiments, all or some of RF transceiver circuitry 1772 may be considered a part of interface 1790. In still other embodiments, interface 1790 may include one or more ports or terminals 1794, radio front end circuitry 1792, and RF transceiver circuitry 1772, as part of a radio unit (not shown), and interface 1790 may communicate with baseband processing circuitry 1774, which is part of a digital unit (not shown).

Antenna 1762 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1762 may be coupled to radio front end circuitry 1790 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 1762 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as MIMO. In certain embodiments, antenna 1762 may be separate from network node 1760 and may be connectable to network node 1760 through an interface or port.

Antenna 1762, interface 1790, and/or processing circuitry 1770 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 1762, interface 1790, and/or processing circuitry 1770 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry 1787 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 1760 with power for performing the functionality described herein. Power circuitry 1787 may receive power from power source 1786. Power source 1786 and/or power circuitry 1787 may be configured to provide power to the various components of network node 1760 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1786 may either be included in, or external to, power circuitry 1787 and/or network node 1760. For example, network node 1760 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry 1787. As a further example, power source 1786 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 1787. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

Alternative embodiments of network node 1760 may include additional components beyond those shown in Figure 17 that may be responsible for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node 1760 may include user interface equipment to allow input of information into network node 1760 and to allow output of information from network node 1760. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1760.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (loT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-loT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device 1710 includes antenna 1711 , interface 1714, processing circuitry 1720, device readable medium 1730, user interface equipment 1732, auxiliary equipment 1734, power source 1736 and power circuitry 1737. WD 1710 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 1710, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, NB-loT, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD 1710.

Antenna 1711 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 1714. In certain alternative embodiments, antenna 1711 may be separate from WD 1710 and be connectable to WD 1710 through an interface or port. Antenna 1711 , interface 1714, and/or processing circuitry 1720 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 1711 may be considered an interface.

As illustrated, interface 1714 comprises radio front end circuitry 1712 and antenna 1711. Radio front end circuitry 1712 comprise one or more filters 1718 and amplifiers 1716. Radio front end circuitry 1714 is connected to antenna 1711 and processing circuitry 1720, and is configured to condition signals communicated between antenna 1711 and processing circuitry 1720. Radio front end circuitry 1712 may be coupled to or a part of antenna 1711. In some embodiments, WD 1710 may not include separate radio front end circuitry 1712; rather, processing circuitry 1720 may comprise radio front end circuitry and may be connected to antenna 1711. Similarly, in some embodiments, some or all of RF transceiver circuitry 1722 may be considered a part of interface 1714. Radio front end circuitry 1712 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1712 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1718 and/or amplifiers 1716. The radio signal may then be transmitted via antenna 1711. Similarly, when receiving data, antenna 1711 may collect radio signals which are then converted into digital data by radio front end circuitry 1712. The digital data may be passed to processing circuitry 1720. In other embodiments, the interface may comprise different components and/or different combinations of components.

Processing circuitry 1720 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD 1710 components, such as device readable medium 1730, WD 1710 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 1720 may execute instructions stored in device readable medium 1730 or in memory within processing circuitry 1720 to provide the functionality disclosed herein.

As illustrated, processing circuitry 1720 includes one or more of RF transceiver circuitry 1722, baseband processing circuitry 1724, and application processing circuitry 1726. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry 1720 of WD 1710 may comprise a SOC. In some embodiments, RF transceiver circuitry 1722, baseband processing circuitry 1724, and application processing circuitry 1726 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 1724 and application processing circuitry 1726 may be combined into one chip or set of chips, and RF transceiver circuitry 1722 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 1722 and baseband processing circuitry 1724 may be on the same chip or set of chips, and application processing circuitry 1726 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 1722, baseband processing circuitry 1724, and application processing circuitry 1726 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 1722 may be a part of interface 1714. RF transceiver circuitry 1722 may condition RF signals for processing circuitry 1720.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry 1720 executing instructions stored on device readable medium 1730, which in certain embodiments may be a computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1720 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1720 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1720 alone or to other components of WD 1710, but are enjoyed by WD 1710 as a whole, and/or by end users and the wireless network generally.

Processing circuitry 1720 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry 1720, may include processing information obtained by processing circuitry 1720 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 1710, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Device readable medium 1730 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1720. Device readable medium 1730 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1720. In some embodiments, processing circuitry 1720 and device readable medium 1730 may be considered to be integrated.

User interface equipment 1732 may provide components that allow for a human user to interact with WD 1710. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 1732 may be operable to produce output to the user and to allow the user to provide input to WD 1710. The type of interaction may vary depending on the type of user interface equipment 1732 installed in WD 1710. For example, if WD 1710 is a smart phone, the interaction may be via a touch screen; if WD 1710 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment 1732 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 1732 is configured to allow input of information into WD 1710, and is connected to processing circuitry 1720 to allow processing circuitry 1720 to process the input information. User interface equipment 1732 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment 1732 is also configured to allow output of information from WD 1710, and to allow processing circuitry 1720 to output information from WD 1710. User interface equipment 1732 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment 1732, WD 1710 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment 1734 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment 1734 may vary depending on the embodiment and/or scenario.

Power source 1736 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD 1710 may further comprise power circuitry 1737 for delivering power from power source 1736 to the various parts of WD 1710 which need power from power source 1736 to carry out any functionality described or indicated herein. Power circuitry 1737 may in certain embodiments comprise power management circuitry. Power circuitry 1737 may additionally or alternatively be operable to receive power from an external power source; in which case WD 1710 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry 1737 may also in certain embodiments be operable to deliver power from an external power source to power source 1736. This may be, for example, for the charging of power source 1736. Power circuitry 1737 may perform any formatting, converting, or other modification to the power from power source 1736 to make the power suitable for the respective components of WD 1710 to which power is supplied.

Figure 18 illustrates one embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter). UE 18200 may be any UE identified by the 3 ^rd Generation Partnership Project (3GPP), including a NB-loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 1800, as illustrated in Figure 18, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3 ^rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable. Accordingly, although Figure 18 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

In Figure 18, UE 1800 includes processing circuitry 1801 that is operatively coupled to input/output interface 1805, radio frequency (RF) interface 1809, network connection interface 1811 , memory 1815 including random access memory (RAM) 1817, read-only memory (ROM) 1819, and storage medium 1821 or the like, communication subsystem 1831 , power source 1833, and/or any other component, or any combination thereof. Storage medium 1821 includes operating system 1823, application program 1825, and data 1827. In other embodiments, storage medium 1821 may include other similar types of information. Certain UEs may utilize all of the components shown in Figure 18, or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

In Figure 18, processing circuitry 1801 may be configured to process computer instructions and data. Processing circuitry 1801 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1801 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface 1805 may be configured to provide a communication interface to an input device, output device, or input and output device. UE 1800 may be configured to use an output device via input/output interface 1805. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE 1800. The output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. UE 1800 may be configured to use an input device via input/output interface 1805 to allow a user to capture information into UE 1800. The input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presencesensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Figure 18, RF interface 1809 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 1811 may be configured to provide a communication interface to network 1843a. Network 1843a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1843a may comprise a Wi-Fi network. Network connection interface 1811 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface 1811 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

RAM 1817 may be configured to interface via bus 1802 to processing circuitry 1801 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM 1819 may be configured to provide computer instructions or data to processing circuitry 1801 . For example, ROM 1819 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium 1821 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable readonly memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium 1821 may be configured to include operating system 1823, application program 1825 such as a web browser application, a widget or gadget engine or another application, and data file 1827. Storage medium 1821 may store, for use by UE 1800, any of a variety of various operating systems or combinations of operating systems.

Storage medium 1821 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium 1821 may allow UE 1800 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium 1821 , which may comprise a device readable medium.

In Figure 18, processing circuitry 1801 may be configured to communicate with network 1843b using communication subsystem 1831. Network 1843a and network 1843b may be the same network or networks or different network or networks. Communication subsystem 1831 may be configured to include one or more transceivers used to communicate with network 1843b. For example, communication subsystem 1831 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.18, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter 1833 and/or receiver 1835 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 1833 and receiver 1835 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem 1831 may include data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. For example, communication subsystem 1831 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1843b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1843b may be a cellular network, a Wi-Fi network, and/or a near-field network. Power source 1813 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 1800.

The features, benefits and/or functions described herein may be implemented in one of the components of UE 1800 or partitioned across multiple components of UE 1800. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem 1831 may be configured to include any of the components described herein. Further, processing circuitry 1801 may be configured to communicate with any of such components over bus 1802. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 1801 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry 1801 and communication subsystem 1831. In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

Figure 19 is a schematic block diagram illustrating a virtualization environment 1900 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 1900 hosted by one or more of hardware nodes 1930. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.

The functions may be implemented by one or more applications 1920 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications 1920 are run in virtualization environment 1900 which provides hardware 1930 comprising processing circuitry 1960 and memory 1990. Memory 1990 contains instructions 1995 executable by processing circuitry 1960 whereby application 1920 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment 1900, comprises general-purpose or special-purpose network hardware devices 1930 comprising a set of one or more processors or processing circuitry 1960, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors. Each hardware device may comprise memory 1990-1 which may be non-persistent memory for temporarily storing instructions 1995 or software executed by processing circuitry 1960. Each hardware device may comprise one or more network interface controllers (NICs) 1970, also known as network interface cards, which include physical network interface 1980. Each hardware device may also include non-transitory, persistent, machine-readable storage media 1990-2 having stored therein software 1995 and/or instructions executable by processing circuitry 1960. Software 1995 may include any type of software including software for instantiating one or more virtualization layers 1950 (also referred to as hypervisors), software to execute virtual machines 1940 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines 1940, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1950 or hypervisor. Different embodiments of the instance of virtual appliance 1920 may be implemented on one or more of virtual machines 1940, and the implementations may be made in different ways.

During operation, processing circuitry 1960 executes software 1995 to instantiate the hypervisor or virtualization layer 1950, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 1950 may present a virtual operating platform that appears like networking hardware to virtual machine 1940.

As shown in Figure 19, hardware 1930 may be a standalone network node with generic or specific components. Hardware 1930 may comprise antenna 19225 and may implement some functions via virtualization. Alternatively, hardware 1930 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) 19100, which, among others, oversees lifecycle management of applications 1920.

Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, virtual machine 1940 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of virtual machines 1940, and that part of hardware 1930 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines 1940, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines 1940 on top of hardware networking infrastructure 1930 and corresponds to application 1920 in Figure 19.

In some embodiments, one or more radio units 19200 that each include one or more transmitters 19220 and one or more receivers 19210 may be coupled to one or more antennas 19225. Radio units 19200 may communicate directly with hardware nodes 1930 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.

In some embodiments, some signalling can be effected with the use of control system 19230 which may alternatively be used for communication between the hardware nodes 1930 and radio units 19200.

Figure 20 illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. In particular, with reference to FIGURE 20, in accordance with an embodiment, a communication system includes telecommunication network 2010, such as a 3GPP-type cellular network, which comprises access network 2011 , such as a radio access network, and core network 2014. Access network 2011 comprises a plurality of base stations 2012a, 2012b, 2012c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 2013a, 2013b, 2013c. Each base station 2012a, 2012b, 2012c is connectable to core network 2014 over a wired or wireless connection 2015. A first UE 2091 located in coverage area 2013c is configured to wirelessly connect to, or be paged by, the corresponding base station 2012c. A second UE 2092 in coverage area 2013a is wirelessly connectable to the corresponding base station 2012a. While a plurality of UEs 2091 , 2092 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 2012.

Telecommunication network 2010 is itself connected to host computer 2030, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 2030 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 2021 and 2022 between telecommunication network 2010 and host computer 2030 may extend directly from core network 2014 to host computer 2030 or may go via an optional intermediate network 2020. Intermediate network 2020 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 2020, if any, may be a backbone network or the Internet; in particular, intermediate network 2020 may comprise two or more sub-networks (not shown).

The communication system of Figure 20 as a whole enables connectivity between the connected UEs 2091 , 2092 and host computer 2030. The connectivity may be described as an over-the-top (OTT) connection 2050. Host computer 2030 and the connected UEs 2091 , 2092 are configured to communicate data and/or signaling via OTT connection 2050, using access network 2011 , core network 2014, any intermediate network 2020 and possible further infrastructure (not shown) as intermediaries. OTT connection 2050 may be transparent in the sense that the participating communication devices through which OTT connection 2050 passes are unaware of routing of uplink and downlink communications. For example, base station 2012 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 2030 to be forwarded (e.g., handed over) to a connected UE 2091. Similarly, base station 2012 need not be aware of the future routing of an outgoing uplink communication originating from the UE 2091 towards the host computer 2030.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Figure 21 . Figure 21 illustrates host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments In communication system 2100, host computer 2110 comprises hardware 2115 including communication interface 2116 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 2100. Host computer 2110 further comprises processing circuitry 2118, which may have storage and/or processing capabilities. In particular, processing circuitry 2118 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 2110 further comprises software 2111 , which is stored in or accessible by host computer 2110 and executable by processing circuitry 2118. Software 2111 includes host application 2112. Host application 2112 may be operable to provide a service to a remote user, such as UE 2130 connecting via OTT connection 2150 terminating at UE 2130 and host computer 2110. In providing the service to the remote user, host application 2112 may provide user data which is transmitted using OTT connection 2150.

Communication system 2100 further includes base station 2120 provided in a telecommunication system and comprising hardware 2125 enabling it to communicate with host computer 2110 and with UE 2130. Hardware 2125 may include communication interface 2126 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 2100, as well as radio interface 2127 for setting up and maintaining at least wireless connection 2170 with UE 2130 located in a coverage area (not shown in Figure 21) served by base station 2120. Communication interface 2126 may be configured to facilitate connection 2160 to host computer 2110. Connection 2160 may be direct or it may pass through a core network (not shown in Figure 21) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 2125 of base station 2120 further includes processing circuitry 2128, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station 2120 further has software 2121 stored internally or accessible via an external connection.

Communication system 2100 further includes UE 2130 already referred to. Its hardware 2135 may include radio interface 2137 configured to set up and maintain wireless connection 2170 with a base station serving a coverage area in which UE 2130 is currently located. Hardware 2135 of UE 2130 further includes processing circuitry 2138, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 2130 further comprises software 2131 , which is stored in or accessible by UE 2130 and executable by processing circuitry 2138. Software 2131 includes client application 2132. Client application 2132 may be operable to provide a service to a human or non-human user via UE 2130, with the support of host computer 2110. In host computer 2110, an executing host application 2112 may communicate with the executing client application 2132 via OTT connection 2150 terminating at UE 2130 and host computer 2110. In providing the service to the user, client application 2132 may receive request data from host application 2112 and provide user data in response to the request data. OTT connection 2150 may transfer both the request data and the user data. Client application 2132 may interact with the user to generate the user data that it provides.

It is noted that host computer 2110, base station 2120 and UE 2130 illustrated in Figure 21 may be similar or identical to host computer 2030, one of base stations 2012a, 2012b, 2012c and one of UEs 2091 , 2092 of Figure 20, respectively. This is to say, the inner workings of these entities may be as shown in Figure 21 and independently, the surrounding network topology may be that of Figure 20.

In Figure 21 , OTT connection 2150 has been drawn abstractly to illustrate the communication between host computer 2110 and UE 2130 via base station 2120, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 2130 or from the service provider operating host computer 2110, or both. While OTT connection 2150 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

Wireless connection 2170 between UE 2130 and base station 2120 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 2130 using OTT connection 2150, in which wireless connection 2170 forms the last segment.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 2150 between host computer 2110 and UE 2130, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 2150 may be implemented in software 2111 and hardware 2115 of host computer 2110 or in software 2131 and hardware 2135 of UE 2130, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 2150 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 2111 , 2131 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 2150 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 2120, and it may be unknown or imperceptible to base station 2120. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 2110’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 2111 and 2131 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 2150 while it monitors propagation times, errors etc.

Figure 22 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21 . For simplicity of the present disclosure, only drawing references to Figure 22 will be included in this section. In step 2210, the host computer provides user data. In substep 2211 (which may be optional) of step 2210, the host computer provides the user data by executing a host application. In step 2220, the host computer initiates a transmission carrying the user data to the UE. In step 2230 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 2240 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 23 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21 . For simplicity of the present disclosure, only drawing references to Figure 23 will be included in this section. In step 2310 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 2320, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 2330 (which may be optional), the UE receives the user data carried in the transmission.

Figure 24 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21 . For simplicity of the present disclosure, only drawing references to Figure 24 will be included in this section. In step 2410 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 2420, the UE provides user data. In substep 2421 (which may be optional) of step 2420, the UE provides the user data by executing a client application. In substep 2411 (which may be optional) of step 2410, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 2430 (which may be optional), transmission of the user data to the host computer. In step 2440 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Figure 25 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 20 and 21 . For simplicity of the present disclosure, only drawing references to Figure 25 will be included in this section. In step 2510 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 2520 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 2530 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

In view of the above, then, embodiments herein generally include a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data. The host computer may also comprise a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE). The cellular network may comprise a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the embodiments described above for a base station.

In some embodiments, the communication system further includes the base station.

In some embodiments, the communication system further includes the UE, wherein the UE is configured to communicate with the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data. In this case, the UE comprises processing circuitry configured to execute a client application associated with the host application.

Embodiments herein also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, providing user data. The method may also comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The base station performs any of the steps of any of the embodiments described above for a base station.

In some embodiments, the method further comprising, at the base station, transmitting the user data.

In some embodiments, the user data is provided at the host computer by executing a host application. In this case, the method further comprises, at the UE, executing a client application associated with the host application.

Embodiments herein also include a user equipment (UE) configured to communicate with a base station. The UE comprises a radio interface and processing circuitry configured to perform any of the embodiments above described for a UE.

Embodiments herein further include a communication system including a host computer. The host computer comprises processing circuitry configured to provide user data, and a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE). The UE comprises a radio interface and processing circuitry. The UE’s components are configured to perform any of the steps of any of the embodiments described above for a UE.

In some embodiments, the cellular network further includes a base station configured to communicate with the UE.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data. The UE’s processing circuitry is configured to execute a client application associated with the host application.

Embodiments also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, providing user data and initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The UE performs any of the steps of any of the embodiments described above for a UE.

In some embodiments, the method further comprises, at the UE, receiving the user data from the base station.

Embodiments herein further include a communication system including a host computer. The host computer comprises a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station. The UE comprises a radio interface and processing circuitry. The UE’s processing circuitry is configured to perform any of the steps of any of the embodiments described above for a UE.

In some embodiments the communication system further includes the UE.

In some embodiments, the communication system further including the base station. In this case, the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application. And the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing request data. And the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

Embodiments herein also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, receiving user data transmitted to the base station from the UE. The UE performs any of the steps of any of the embodiments described above for the UE.

In some embodiments, the method further comprises, at the UE, providing the user data to the base station.

In some embodiments, the method also comprises, at the UE, executing a client application, thereby providing the user data to be transmitted. The method may further comprise, at the host computer, executing a host application associated with the client application.

In some embodiments, the method further comprises, at the UE, executing a client application, and, at the UE, receiving input data to the client application. The input data is provided at the host computer by executing a host application associated with the client application. The user data to be transmitted is provided by the client application in response to the input data.

Embodiments also include a communication system including a host computer. The host computer comprises a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station. The base station comprises a radio interface and processing circuitry. The base station’s processing circuitry is configured to perform any of the steps of any of the embodiments described above for a base station.

In some embodiments, the communication system further includes the base station.

In some embodiments, the communication system further includes the UE. The UE is configured to communicate with the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application. And the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.

Embodiments moreover include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. The UE performs any of the steps of any of the embodiments described above for a UE.

In some embodiments, the method further comprises, at the base station, receiving the user data from the UE.

In some embodiments, the method further comprises, at the base station, initiating a transmission of the received user data to the host computer.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the description.

The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

The term “A and/or B” as used herein covers embodiments having A alone, B alone, or both A and B together. The term “A and/or B” may therefore equivalently mean “at least one of any one or more of A and B”.

Some of the embodiments contemplated herein are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

Notably, modifications and other embodiments of the disclosed invention(s) will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention(s) is/are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of this disclosure. Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Example embodiments of the techniques and apparatus described herein include, but are not limited to, the following enumerated examples:

Group A Embodiments

A1 . A method performed by an integrated access backhaul, IAB, node in an IAB network, the method comprising: receiving, from a first donor central unit, CU, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU.

A2. The method of embodiment A1 , wherein the one or more first resources include one or more first addresses for the first wireless backhaul, and wherein the one or more second resources include one or more second addresses for the second wireless backhaul.

A3. The method of embodiment A2, wherein the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and wherein the one or more second addresses are one or more BAP addresses.

A4. The method of any of embodiments A1-A3, wherein the one or more first resources include one or more first routing identities for the first wireless backhaul, and wherein the one or more second resources include one or more second routing identities for the second wireless backhaul.

A5. The method of embodiment A4, wherein the one or more first routing identities are one or more BAP routing identities, and wherein the one or more second routing identities are one or more BAP routing identities. A6. The method of any of embodiments A1-A3, wherein the one or more first resources include one or more first channels for the first wireless backhaul, and wherein the one or more second resources include one or more second channels for the second wireless backhaul.

A7. The method of embodiment A6, wherein the one or more first channels are one or more Radio Link Control, RLC, channels, and wherein the one or more second channels are one or more RLC channels.

A8. The method of any of embodiments A1-A7, wherein the first donor CU is in a first network and the second donor CU is in a second network.

A9. The method of any of embodiments A1-A8, wherein the one or more first resources are associated with or assigned to a first mobile termination protocol stack at the IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination protocol stack at the IAB node.

A10. The method of any of embodiments A1 -A9, wherein the one or more first resources are associated with or assigned to a first mobile termination at the IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination at the IAB node.

A11 . The method of any of embodiments A1 -A10, wherein the IAB node serves one or more child IAB nodes that are controlled by the first donor CU and that are respectively assigned the one or more first resources.

A12. The method of embodiment A11 , wherein the one or more first resources are mapped to one or more different respective second resources.

A13. The method of any of embodiments A1 -A12, wherein the IAB node is controlled by both the first donor CU and the second donor CU.

A14. The method of any of embodiments A1 -A13, wherein receiving the mapping comprises receiving a table that indicates the mapping, wherein the table is a routing table or a translation table.

A15. The method of any of embodiments A1 -A14, wherein receiving the mapping comprises receiving the mapping during, as part of, or in response to performing a reconfiguration procedure to establish a connection between the IAB node and the second donor CU. A16. The method of embodiment A15, further comprising performing the reconfiguration procedure upon the occurrence of one or more events.

A17. The method of any of embodiments A1 -A16, wherein receiving the mapping comprises receiving the mapping in an RRC Reconfiguration Complete message.

A18. The method of any of embodiments A1-A17, based on the mapping, transmitting at least some traffic using the first wireless backhaul and at least some traffic using the second wireless backhaul.

A19. The method of any of embodiments A1-A18, based on the mapping, receiving at least some traffic using the first wireless backhaul and at least some traffic using the second wireless backhaul.

A20. The method of any of embodiments A1 -A19, further comprising routing traffic using the mapping.

A21 . The method of any of embodiments A1-A20, further comprising: receiving, from a parent IAB node or from a second donor distributed unit, a packet using one of the one or more second resources; mapping the second resource used to receive the packet to a first resource according to the received mapping; and routing the packet to a child IAB node or to a served user equipment using the mapped first resource.

A22. The method of embodiment A21 , wherein said routing comprises modifying a header of the packet using the mapped first resource and delivering the packet to a lower layer for forwarding using the mapped first resource.

A23. The method of any of embodiments A1-A21 , further comprising: receiving, from a child IAB node or a served user equipment, a packet using one of the one or more first resources; mapping the first resource used to receive the packet to a second resource according to the received mapping; and routing the packet to a parent IAB node or to a second donor distributed unit using the mapped second resource. A24. The method of embodiment A23, wherein said routing comprises modifying a header of the packet using the mapped second resource and delivering the packet to a lower layer for forwarding using the mapped second resource.

A25. The method of any of embodiments A1 -A24, further comprising deciding whether to transmit a packet via the first wireless backhaul or the second wireless backhaul based on one or more rules received from the first donor CU.

AA. The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission to a base station.

Group B Embodiments

B1 . A method performed by a first donor central unit, CU, in an integrated access backhaul, IAB, network, the method comprising: transmitting, from the first donor CU to an IAB node, a mapping between one or more first resources for a first wireless backhaul controlled by the first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU.

B2. The method of embodiment B1 , wherein the one or more first resources include one or more first addresses for the first wireless backhaul, and wherein the one or more second resources include one or more second addresses for the second wireless backhaul.

B3. The method of embodiment B2, wherein the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and wherein the one or more second addresses are one or more BAP addresses.

B4. The method of any of embodiments B1-B3, wherein the one or more first resources include one or more first routing identities for the first wireless backhaul, and wherein the one or more second resources include one or more second routing identities for the second wireless backhaul.

B5. The method of embodiment B4, wherein the one or more first routing identities are one or more BAP routing identities, and wherein the one or more second routing identities are one or more BAP routing identities.

B6. The method of any of embodiments B1-B3, wherein the one or more first resources include one or more first channels for the first wireless backhaul, and wherein the one or more second resources include one or more second channels for the second wireless backhaul.

B7. The method of embodiment B6, wherein the one or more first channels are one or more Radio Link Control, RLC, channels, and wherein the one or more second channels are one or more RLC channels.

B8. The method of any of embodiments B1-B7, wherein the first donor CU is in a first network and the second donor CU is in a second network.

B9. The method of any of embodiments B1-B8, wherein the one or more first resources are associated with or assigned to a first mobile termination protocol stack at the IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination protocol stack at the IAB node.

B10. The method of any of embodiments B1-B9, wherein the one or more first resources are associated with or assigned to a first mobile termination at the IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination at the IAB node.

B11. The method of any of embodiments B1-B10, wherein the IAB node serves one or more child IAB nodes that are controlled by the first donor CU and that are respectively assigned the one or more first resources.

B12. The method of embodiment B11 , wherein the one or more first resources are mapped to one or more different respective second resources.

B13. The method of any of embodiments B1-B12, wherein the IAB node is controlled by both the first donor CU and the second donor CU.

B14. The method of any of embodiments B1-B13, wherein transmitting the mapping comprises transmitting a table that indicates the mapping, wherein the table is a routing table or a translation table.

B15. The method of any of embodiments B1-B14, wherein transmitting the mapping comprises transmitting the mapping during, as part of, or in response to performing a reconfiguration procedure to establish a connection between the IAB node and the second donor CU. B16. The method of embodiment B15, further comprising performing the reconfiguration procedure upon the occurrence of one or more events.

B17. The method of any of embodiments B1-B16, wherein transmitting the mapping comprises transmitting the mapping in an RRC Reconfiguration Complete message.

B18. The method of any of embodiments B1-B17, based on the mapping, transmitting at least some traffic via the first wireless backhaul and at least some traffic via the second wireless backhaul.

B19. The method of any of embodiments B1-B18, based on the mapping, receiving at least some traffic via the first wireless backhaul and at least some traffic via the second wireless backhaul.

B20. The method of any of embodiments B1 -B19, further comprising routing traffic using the mapping.

B21 . The method of any of embodiments B1-B20, further comprising transmitting, to the IAB node, one or more rules according to which the IAB node is to decide whether to transmit an uplink packet via the first wireless backhaul or the second wireless backhaul.

B22. The method of any of embodiments B1-B21 , further comprising transmitting, to the second donor CU, a request for a number of second resources that are to be allocated for the second wireless backhaul controlled by the second donor CU and that are to be associated with the first donor CU.

B23. The method of embodiment B22, further comprising: receiving a response that indicates the one or more second resources allocated in accordance with the request; and generating the mapping based on the response.

B24. The method of any of embodiments B1-B23, further comprising transmitting, to the second donor CU, an indication of an amount of traffic to be offloaded from the first donor CU or the first wireless backhaul to the second donor CU or the second wireless backhaul.

B23. The method of any of embodiments B1-B22, BB. The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host computer or a wireless device.

Group X Embodiments

X1 . A method performed by a second donor central unit, CU, in an integrated access backhaul, IAB, network, the method comprising: receiving, from a first donor CU, a request for a number of second resources that are to be allocated for a second wireless backhaul controlled by the second donor CU and that are to be associated with the first donor CU.

X2. The method of embodiment X1 , further comprising transmitting a response that indicates one or more second resources allocated in accordance with the request.

X3. The method of any of embodiments X1-X2, further comprising receiving, from the first donor CU, an indication of an amount of traffic to be offloaded from the first donor CU or a first wireless backhaul to the second donor CU or the second wireless backhaul.

Group Y Embodiments

Y1 . A method performed by a second donor distributed unit, DU, in an integrated access backhaul, IAB, network, the method comprising: receiving a mapping between one or more first resources for a first wireless backhaul controlled by a first donor CU and one or more second resources for a second wireless backhaul controlled by a second donor CU.

Y2. The method of embodiment Y1 , wherein the one or more first resources include one or more first addresses for the first wireless backhaul, and wherein the one or more second resources include one or more second addresses for the second wireless backhaul.

Y3. The method of embodiment Y2, wherein the one or more first addresses are one or more Backhaul Adaptation Protocol, BAP, addresses, and wherein the one or more second addresses are one or more BAP addresses.

Y4. The method of any of embodiments Y1-Y3, wherein the one or more first resources include one or more first routing identities for the first wireless backhaul, and wherein the one or more second resources include one or more second routing identities for the second wireless backhaul. Y5. The method of embodiment Y4, wherein the one or more first routing identities are one or more BAP routing identities, and wherein the one or more second routing identities are one or more BAP routing identities.

Y6. The method of any of embodiments Y1-Y3, wherein the one or more first resources include one or more first channels for the first wireless backhaul, and wherein the one or more second resources include one or more second channels for the second wireless backhaul.

Y7. The method of embodiment Y6, wherein the one or more first channels are one or more Radio Link Control, RLC, channels, and wherein the one or more second channels are one or more RLC channels.

Y8. The method of any of embodiments Y1-Y7, wherein the first donor CU is in a first network and the second donor CU is in a second network.

Y9. The method of any of embodiments Y1-Y8, wherein the one or more first resources are associated with or assigned to a first mobile termination protocol stack at an IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination protocol stack at the IAB node.

Y10. The method of any of embodiments Y1 -Y9, wherein the one or more first resources are associated with or assigned to a first mobile termination at an IAB node, and wherein the one or more second resources are associated with or assigned to a second mobile termination at the IAB node.

Y11. The method of any of embodiments Y1-Y10, wherein an IAB node serves one or more child IAB nodes that are controlled by the first donor CU and that are respectively assigned the one or more first resources.

Y12. The method of embodiment Y11 , wherein the one or more first resources are mapped to one or more different respective second resources.

Y13. The method of any of embodiments Y1-Y12, wherein an IAB node is controlled by both the first donor CU and the second donor CU.

Y14. The method of any of embodiments Y1-Y13, wherein receiving the mapping comprises receiving a table that indicates the mapping, wherein the table is a routing table or a translation table.

Y15. The method of any of embodiments Y1-Y14, wherein receiving the mapping comprises receiving the mapping during, as part of, or in response to performing a reconfiguration procedure to establish a connection between an IAB node and the second donor CU.

Y16. The method of any of embodiments Y1-Y15, further comprising routing traffic using the mapping.

Y17. The method of any of embodiments Y1-Y16, further comprising: receiving, from a child IAB node or a served user equipment, a packet using one of the one or more second resources; mapping the second resource used to receive the packet to a first resource according to the received mapping; and routing the packet towards the first donor CU using the mapped first resource.

Group C Embodiments

C1 . An IAB node configured to perform any of the steps of any of the Group A embodiments.

C2. An IAB node comprising processing circuitry configured to perform any of the steps of any of the Group A embodiments.

C3. An IAB node comprising: communication circuitry; and processing circuitry configured to perform any of the steps of any of the Group A embodiments.

C4. An IAB node comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the IAB node.

C5. An IAB node comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the IAB node is configured to perform any of the steps of any of the Group A embodiments.

C6. Reserved C7. A computer program comprising instructions which, when executed by at least one processor of an IAB node, causes the IAB node to carry out the steps of any of the Group A embodiments.

C8. A carrier containing the computer program of embodiment C7, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

C9. A donor CU configured to perform any of the steps of any of the Group B or Group X embodiments.

C10. A donor CU comprising processing circuitry configured to perform any of the steps of any of the Group B or Group X embodiments.

C11. A donor CU comprising: communication circuitry; and processing circuitry configured to perform any of the steps of any of the Group B or Group X embodiments.

C12. A donor CU comprising: processing circuitry configured to perform any of the steps of any of the Group B or Group X embodiments; power supply circuitry configured to supply power to the donor CU.

C13. A donor CU comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the donor CU is configured to perform any of the steps of any of the Group B or Group X embodiments.

C14. Reserved.

C15. A computer program comprising instructions which, when executed by at least one processor of a donor CU, causes the donor CU to carry out the steps of any of the Group B or Group X embodiments.

C16. Reserved.

C17. A carrier containing the computer program of any of embodiments C15-C16, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

C18. A donor DU configured to perform any of the steps of any of the Group Y embodiments.

C19. A donor DU comprising processing circuitry configured to perform any of the steps of any of the Group B or Group Y embodiments.

C20. A donor DU comprising: communication circuitry; and processing circuitry configured to perform any of the steps of any of the Group Y embodiments.

C21. A donor DU comprising: processing circuitry configured to perform any of the steps of any of the Group Y embodiments; power supply circuitry configured to supply power to the donor DU.

C22. A donor DU comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the donor DU is configured to perform any of the steps of any of the Group Y embodiments.

C23. Reserved.

C24. A computer program comprising instructions which, when executed by at least one processor of a donor DU, causes the donor DU to carry out the steps of any of the Group Y embodiments.

C25. Reserved.

C26. A carrier containing the computer program of any of embodiments C24-C25, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.