Title of Invention: SUPPORTING IAB CP SIGNALING OVER LTE Abstract: A method by a first network node in an Integrated Access and Wireless Access Backhaul (IAB) network is provided. The method includes, in the absence of an New Radio (NR) link between the first network node and a second network in the IAB network, sending, to the second network node over Long Term Evolution, LTE, radio, one or more Stream Control Transmission Protocol/Internet Protocol (SCTP/IP) packets. The one or more SCTP/IP packets includes F1-Application Protocol (F1-AP) signaling. Detailed Description: TECHNICAL FIELD The present disclosure relates, in general, to wireless communications and, more particularly, systems and methods for supporting integrated access and wireless access backhaul (IAB) Control Plane (CP) Signaling over Long Term Evolution (LTE). BACKGROUND The 3rd Generation Partnership Project (3GPP) is currently standardizing integrated access and wireless access backhaul (IAB) in New Radio (NR) in Release 16 (RP-RP-182882). The use 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., at historical sites). A 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, 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 multiple-output (MIMO) support in NR reduce cross-link interference between backhaul and access links allowing higher densification. During the study item phase of the IAB work (a summary of the study item can be found in the technical report 3GPP TR 38.874), it has been agreed to adopt a solution that leverages the Central Unit (CU)/Distributed Unit (DU) split architecture of NR, where the IAB node hosts a DU part that is controlled by a central unit. The IAB nodes also have a Mobile Termination (MT) part that they use to communicate with their parent nodes. The specifications for IAB strives to reuse existing functions and interfaces defined in NR. In particular, MT, gNodeB-Distributed Unit (gNB-DU), gNodeB-Central Unit (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. Modifications or enhancements to these functions and interfaces for the support of IAB will be explained in the context of the architecture discussion. Additional functionality such as multi-hop forwarding is included in the architecture discussion as it is necessary for the understanding of IAB operation and since certain aspects may require standardization. The MT function has been defined as a component of the IAB node. In the context of this study, MT is referred to as a function residing on an IAB-node that terminates the radio interface layers of the backhaul Uu interface toward the IAB-donor or other IAB-nodes. FIG. 1 illustrates a high-level architectural view of an IAB network. More particularly, FIG. 1 shows a reference diagram taken from 3GPP TR 38.874 for IAB in standalone mode, which contains one IAB-donor and multiple IAB-nodes. The IAB-donor is treated as a single logical node that comprises a set of functions such as gNodeB-Distributed Unit (gNB-DU), gNodeB-Central Unit-Control Plane (gNB-CU-CP), gNodeB-Central Unit-User Plane (gNB-CU-UP) and potentially other functions. In a deployment, the IAB-donor can be split according to these functions, which can all be either collocated or non-collocated as allowed by 3GPP Next Generation-Radio Access Network (NG-RAN) architecture. IAB-related aspects may arise when such split is exercised. Also, some of the functions presently associated with the IAB-donor may eventually be moved outside of the donor in case it becomes evident that they do not perform IAB-specific tasks. FIG. 2 illustrates the baseline user protocol stack for IAB in Rel-16. FIGS. 3A-3B illustrate the baseline control plane protocol stacks for IAB in Rel-16. As shown in the figures, the chosen protocol stacks reuse the current CU-DU split specification in Release 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). 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 Control Plane (CP)). IPsec could also be used for the CP protection instead of DTLS (in this case no DTLS layer would be used). A new protocol layer called Backhaul Adaptation Protocol (BAP) has been introduced in the IAB nodes and the IAB donor, which is used for routing of packets to the appropriate downstream/upstream node and also mapping the User Equipment (UE) bearer data to the proper backhaul Radio Link Control (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. At the RAN2 #105 meeting, the modelling of the Adaptation layer was discussed and the following was agreed: RAN2 confirms that routing and bearer mapping (e.g. mapping of BackHaul (BH) RLC channels) are adaptation layer functions R2 assumes that Transmission (TX) part of adaptation layer performs routing and “bearer mapping”, Reception (RX) part of adaptation layer performs “bearer demapping” R2 assumes that Service Data Units (SDUs) are forwarded from RX part of adaptation layer to TX part of adaptation layer (for the next hop) for packets that are relayed by the IAB node. How to model with regard to protocol entities, e.g. whether separate for DU and MT or not, and how these are configured, F1-AP or Radio Resource Control (RRC), was left for future study. Though there is no final agreement in RAN2, there is a consensus about including the BAP entity in both MT and DU parts of the IAB-node protocol stack. Modelling the BAP layer this way facilitates the realization of the routing and mapping functionalities of the adaptation layer. Before discussing the operations of the two BAP entities, the first thing to consider is whether the radio bearers carrying CP/UP traffic for the MT functionality of an IAB node should be handled separately from the Back Haul Radio Link Control (BH RLC) channels. Note that the BH RLC channels are used to carry traffic to/from the IAB DU functionality, which could be either be intended for the UEs served by the IAB node or for the child IAB nodes. They (e.g., radio bearers and BH RLC channels) should be handled separately by employing different logical channel IDs. The procedure for downlink (DL) follows: 1. When a packet arrives at the IAB donor DU (from the donor CU) and is processed first by the upper layers (as there is no MT BAP layer at the donor DU). a) If the packet is destined to UEs directly connected to the IAB donor DU or it is an F1-AP traffic destined at the IAB donor DU, it is forwarded to higher layers (IP/UDP/GTP-U for UP, IP/SCTP/F1-AP for CP). b) Otherwise (i.e., it is to be forwarded further downstream), it is forwarded to the DU BAP layer. 2. When a packet arrives at an IAB node (from a parent IAB node or IAB donor DU) via backhaul RLC channels is processed first by the MT BAP layer. a) If the packet is destined to UEs directly connected to the IAB node or F1-AP traffic destined at the IAB node's DU, it is forwarded to higher layers (IP/UDP/GTP-U for UP, IP/SCTP/F1-AP for CP). b) Otherwise (i.e., it is to be forwarded further downstream, it is forwarded to the DU BAP layer. In both 1b and 2b above, the DU BAP will determine which route (i.e., to which child node) the packet has to be forwarded to and which BH RLC channel within that route will be used for forwarding the packet downstream (the input information for the BH RLC mapping is still discussed in RAN2). The procedure for uplink (UL) follows: 1. When a packet arrives at the IAB donor DU (from a child IAB node) via backhaul RLC channels, it is processed first by the DU BAP layer and is forwarded to the donor CU (as the donor DU can be connected to at most one donor CU, there is no routing functionality required). 2. When a packet arrives at an IAB node in the UL direction: a. If it is coming from a child IAB node via backhaul RLC channels it is processed first by the DU BAP layer and, since every UL packet is destined to be forwarded to the donor CU, it is passed on to the MT BAP layer. b. If the packet is from a UE connected directly to the IAB node, or it is an F1-AP traffic originating from the IAB node, it is processed first by the higher layers (IP/UDP/GTP-U for UP, IP/SCTP/F1-AP for CP), and is forwarded to the MT BAP layer. In both 2a and 2b above, the MT BAP will determine which route (i.e., which parent node) the packet has to be forwarded to and which BH RLC channel within that route will be used for forwarding the packet upstream. FIG. 4 illustrates an example IAB node integration procedure. The setup and configuration (i.e., integration) for the IAB node is the first step in the operation of the IAB node. The integration procedure included the following steps: 1. MT Setup MT selects parent node (procedure is for further study (FFS)). MT authenticates with AMF (Uu procedures). AMF authorizes MT at gNB (signaling agreed at RAN3 #103). gNB establishes SRBs with MT (Uu procedures). gNB may establish Data Radio Bearers (DRBs) and Protocol Data Unit (PDU) session with MT (Uu procedures; if this is necessary is FFS). PDU session may be used for Operations & Maintenance (OAM) connectivity. 2. Backhaul Setup Establishment of BH RLC channel between IAB-node MT and parent node. RAN2 decided that this configuration is done by CU-CP (e.g., using Radio Resource Control (RRC)). For this, MT's CU-CP needs to know that MT belongs to an IAB node and not a UE, which it may derive, for example, from MT authorization (agreed at RAN3 #103). The BH RLC channel further has to be marked with the corresponding priority/QoS-class on IAB-node MT and parent node. Establishment of adapt route(s) between IAB-node MT and IAB-donor DU. This includes: Configuration of adapt routing identifier(s) on IAB-node MT and IAB-donor DU (RAN2; FFS); and Configuration of routing entries on all IAB-node's ancestor nodes for new routing identifier (RAN2; FFS). IP address allocation to IAB-node for adapt interface, which is routable from wireline fronthaul via adapt route. The IP address must be specific to IAB-donor DU so that CU can send IP packets to IAB-node via this specific IAB-donor DU and the new adapt route. The IAB-donor DU has to support a pool of IP addresses that are routable from wireline fronthaul for all descendant IAB-nodes. If IP assignment is done by CU, the CU must know IAB-donor-DU's available IP address pool for IAB nodes. If IP assignment is done via DHCPv4/6 with DHCP proxy on IAB-donor-DU, as proposed in TR, a transport mechanism of ARP/NDP on top of adapt layer needs to be defined. There may be other options for IP address allocation. 3. DU Setup DU establishes F1-C and cell activation using IP on adapt layer (procedure defined in TS 38.401 clause 8.5: F1 startup and cells activation). This includes OAM support for IAB-node DU via backhaul IP layer. It is important to note that the recommended architecture option (Option 1a in 3GPP TR 38.874) can manage IP address assignment internally in the Radio Access Network (RAN) without Core Network (CN) involvement. In that respect, the above baseline allows for Dynamic Host Configuration Protocol (DHCP)-based IP address assignment and setting up the OAM after IP address assignment without MT establishing a PDU session. The three parts of the overall IAB node integration procedure are discussed below. 1. MT Functionality Setup The IAB node will first connect via its MT functionality using RRC setup procedure. After RRC connection setup, the MT functionality of the IAB node could perform Non-Access Stratum (NAS)-level registration and authentication, but no PDU session establishment is required, as shown in FIG. 12. After the NAS registration, UE context for the IAB node can be created in the Radio Access Network (RAN) (without any PDU session resources). In this way, there is no need to support any SMF/UPF functionality for the IAB nodes. NAS Rel-15 already separates the NAS registration from the PDU session establishment, making it possible to only perform registration without setting up PDU sessions, as well as setting up a UE context in RAN without PDU session resources. 2. Backhaul Setup Once the UE context for the IAB node is setup in the RAN, the RAN will establish one or more backhaul bearers that can be used for IP address assignment to IAB node. For the situations where the IAB node is not directly communicating with the IAB-Donor node, but via other (already attached/connected) IAB nodes, the forwarding information in all intermediate IAB nodes will be updated due to the setup of new IAB node. 3. DU Functionality Setup After establishing connectivity to the operator's internal network, the DU functionality of IAB node and its cells/sectors need to be configured by the OAM before the DU can send an F1 SETUP REQUEST message to its corresponding CU (i.e., IAB-CU). The recommended architecture option for IAB supports the full IP connectivity to the IAB node, making it possible that the DU functionality can have direct IP connectivity to the OAM, instead of relying on the MT functionality to establish a special PDU session in the Core Network (CN) for OAM. Finally, after configuring the DU functionality of the IAB node, the IAB node becomes operational as a DU and UEs will not be able to distinguish it from other gNBs. As such, it can start serving UEs like any other DU/gNB. The procedure for initial IAB node access can be based on the UE Initial Access signaling flow with slight modifications to fulfil the IAB node requirements. Meanwhile, for activation of IAB node DU cells, the F1 Startup and cells activation procedure defined in 3GPP TS 38.401 can be reused as is. Taking the above into account, the present disclosure proposes the process for integrating the IAB node into the NG-RAN described below and shown in FIG. 12. IAB Initial Access and MT Functionality Setup 1. The IAB node sends an RRCSetupRequest message to the gNB-DU. 2. The gNB-DU includes the RRC message and, if the IAB node is admitted, the corresponding lower layer configuration for the NR Uu interface in the INITIAL UL RRC TRANSFER message and transfers to the gNB-CU. The INITIAL UL RRC TRANSFER message includes the Cell Radio Network Temporary Identifier (C-RNTI) allocated by the gNB-DU. 3. The gNB-CU allocates a gNB-CU UE F1AP ID for the IAB node and generates RRCSetup message towards the IAB node. The RRC message is encapsulated in the DL RRC MESSAGE TRANSFER message. 4. The gNB-DU sends the RRCSetup message to the IAB node. 5. The IAB node sends the RRC CONNECTION SETUP COMPLETE message to the gNB-DU. The S-NSSAI IE in the RRC CONNECTION SETUP COMPLETE message indicates the IAB node. 6. The gNB-DU encapsulates the RRC message in the UL RRC MESSAGE TRANSFER message and sends it to the gNB-CU. 7. The gNB-CU sends the INITIAL UE MESSAGE to the AMF. This could be a dedicated AMF serving only the IAB nodes. At this point the IAB node will perform registration (including authentication and key generation) without establishing a PDU session. 8. The AMF sends the INITIAL CONTEXT SETUP REQUEST message to the gNB-CU. 9. The gNB-CU sends the IAB CONTEXT SETUP REQUEST message to establish the IAB node context in the gNB-DU. In this message, it may also encapsulate the SecurityModeCommand message. 10. The gNB-DU sends the SecurityModeCommand message to the IAB node. 11. The gNB-DU sends the IAB CONTEXT SETUP RESPONSE message to the gNB-CU. 12. The IAB node responds with the SecurityModeComplete message. 13. The gNB-DU encapsulates the RRC message in the UL RRC MESSAGE TRANSFER message and sends it to the gNB-CU. 14. The gNB-CU generates the RRCReconfiguration message and encapsulates it in the DL RRC MESSAGE TRANSFER message. The RRCReconfiguration could include a configuration of one or more IAB backhaul bearers. 15. The gNB-DU sends RRCReconfiguration message to the IAB node. 16. The IAB node sends RRCReconfigurationComplete message to the gNB-DU. 17. The gNB-DU encapsulates the RRC message in the UL RRC MESSAGE TRANSFER message and sends it to the gNB-CU. 18. The gNB-CU sends the INITIAL CONTEXT SETUP RESPONSE message to the AMF. IAB Node DU Cells Activation At this point, the IAB node will have established one or more backhaul bearers that can be used for creating Transport Network Layer (TNL) connectivity toward gNB-CU and getting TNL address (e.g., IP address and port assignments). Next, the IAB node can utilize the F1 Startup and Cells Activation procedures described in TS 38.401 to activate its cells and become operational. IAB Node Ready to Serve UEs After activating its cells, the IAB node is operational and can serve the UEs. The UEs can connect to the IAB node via the UE Initial Access procedure described in TS 38.401. Bearer Mapping in IAB Networks An IAB-node needs to multiplex the UE DRBs to the BH RLC-Channel. The following two options can be considered on bearer mapping in IAB-node. The first option is a one-to-one mapping between UE DRB and BH RLC-channel FIG. 5 illustrates an example of one-to-one mapping between UE DRB and BH RLC-channel According to this option, each UE DRB is mapped onto a separate BH RLC-channel. Further, each BH RLC-channel is mapped onto a separate BH RLC-channel on the next hop. The number of established BH RLC-channels is equal to the number of established UE DRBs. Identifiers (e.g. for the UE and/or DRB) may be required (e.g. if multiple BH RLC-channels are multiplexed into a single BH logical channel). Which exact identifiers are needed, and which of these identifier(s) are placed within the adaptation layer header depends on the architecture/protocol option. The second option is a many-to-one mapping between UE DRBs and BH RLC-channel FIG. 6 illustrates an example of many-to-one mapping between UE DRBs and BH RLC-channel. For the many-to-one mapping, several UE DRBs are multiplexed onto a single BH RLC-channel based on specific parameters such as bearer QoS profile. Other information such as hop-count could also be configured. The IAB-node can multiplex UE DRBs into a single BH RLC-channel even if they belong to different UEs. Furthermore, a packet from one BH RLC-channel may be mapped onto a different BH RLC-channel on the next hop. All traffic mapped to a single BH RLC-channel receive the same QoS treatment on the air interface. Since the BH RLC-channel multiplexes data from/to multiple bearers, and possibly even different UEs, each data block transmitted in the BH RLC-channel needs to contain an identifier of the UE, DRB, and/or IAB-node it is associated with. Which exact identifiers are needed, and which of these identifier(s) are placed within the adaptation layer header depends on the architecture/protocol option. It has been agreed to support both N:1 and 1:1 mapping in Release 16. For 1:1 bearer mapping, it has been agreed to use the IPv6 Flow Label field, where the donor DU is configured to mapping IP packets that are marked with a given flow label to a particular LCID on the first backhaul link between the donor DU and the first downstream IAB node. For the case of N:1 mapping, the working assumption is the DSCP field in the IP header can be used for the mapping purpose (in order to support also IPv4 networks). However, there is a discussion whether to have a unified behavior where the IPv6 Flow Label can be used for N:1 mapping as well. It is also be considered to use the combination of the flow label and the DSCP field to use for 1:1 mapping IAB Deployment in Evolved-Universal Terrestrial Radio Access Network-New Radio—Dual Connectivity (EN-DC) Mode IAB is a feature where an NR radio base station (IAB Node) is being backhauled via an NR radio link towards a Donor radio base station (gNB). It has been agreed to support IAB using NR Stand-Alone operation, as well as Non-Stand-Alone (NSA) operation where the IAB Node is also connected to Long Term Evolution (LTE) radio interface and LTE radio base station for handling control plane signaling. Under NSA NR deployment, an IAB network has to operate in EN-DC mode (i.e., LTE as a master and NR as a secondary node). FIG. 11 illustrates an example of IAB deployment in EN-DC mode. It has been agreed in 3GPP that the NR traffic will be backhauled over the NR leg and the LTE traffic has to pass through the LTE leg (i.e., no NR traffic sent over the LTE leg or vice versa). There currently exist certain challenges. For example, there have been proposals for IAB Nodes operating in Non-Stand-Alone mode to support NR IAB related control plane signaling (between the Donor gNB and IAB node) via LTE. The motivation for this is that if the NR link for some reason (e.g., radio link failure) would be lost it would be possible to perform critical NR IAB related signaling via the LTE link. Also, if there are several hops in the IAB network, sending CP traffic via the LTE leg may end up being faster than sending it via the multiple hops. The proposed approach was to tunnel IAB related F1-AP signaling messages via X2 signaling to the LTE eNB and embed them in an LTE RRC signaling towards the IAB node over LTE radio. There are certain drawbacks to this approach. One drawback with this proposed approach is that it is not so straight forward to support F1-AP signaling messages via LTE as suggested in the contributions above, since currently the F1-AP signaling protocol relies on functionality provided by its lower layers such as SCTP and IP, which is now proposed to be handled instead by LTE RRC and X2-AP. For instance The IP layer provides addressing information making it possible to setup multiple F1-AP connections (e.g., in case the JAB node supports multiple DU instances). The SCTP layer provides reliable in-order delivery of F1-AP messages, which the F1-AP protocol expects from lower layer. SCTP also has additional functionality such as keep alive signaling, multi-homing, etc., which higher layer may require. Not using SCTP on the LTE leg makes it difficult to guarantee loss-less, duplication free in-order delivery of F1-AP message which has already been sent down to the SCTP layer used over the NR radio link but has not yet been delivered end to end (e.g., at the time the NR radio link is lost). SUMMARY Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges. The present disclosure introduces a mechanism for the New Radio (NR) Donor gNodeB (gNB) to exchange F1-Application Protocol (F1-AP) signaling with the Integrated Access and Wireless Access Backhaul (JAB) node over the Long Term Evolution (LTE) radio using a solution where the whole Stream Control Transmission Protocol/Internet Protocol (SCTP/IP) packets are delivered between the NR Donor gNB and JAB node. According to certain embodiments, a method by a first network node in an JAB network is provided. The method includes, in the absence of an NR link between the first network node and a second network in the JAB network, sending, to the second network node over Long Term Evolution, LTE, radio, one or more SCTP/IP packets. The one or more SCTP/IP packets includes F1-Application Protocol (F1-AP) signaling. According to certain embodiments, a first network node includes processing circuitry configured to, in the absence of an NR link between the first network node and a second network in the IAB network, send, to the second network node over Long Term Evolution, LTE, radio, one or more SCTP/IP packets. The one or more SCTP/IP packets includes F1-Application Protocol (F1-AP) signaling. Certain embodiments may provide one or more of the following technical advantages. As one example, a technical advantage may be that certain embodiments may support reliable delivery of NR IAB-related signaling between the Donor gNB and IAB node via LTE radio, which can, for instance, be used when the NR radio link is experiencing problems or is lost. In certain embodiments, the approach described herein does this by transferring full (or whole) SCTP/IP packets (or Internet Protocol Packet Data Units (IP PDUs)) over the LTE radio and between the LTE eNB and NR Donor gNB. By delivering whole SCTP/IP packets it is advantageously possible to still use the features provided by SCTP/IP, such as: End to end SCTP guaranteed delivery, which advantageously avoids the need to support/specify LTE mechanism to handle the reliable delivery; SCTP multi-homing, ensuring seamless/loss-less switch to LTE when the NR link is lost; Other SCTP functions such as duplication removal, Quality of Service (QoS) streams, in order delivery, etc.; and An IP-addressing mechanism allowing multiple SCTP connections. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the disclosed embodiments and their features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: FIG. 1 illustrates a high-level architectural view of an integrated access and wireless access backhaul (IAB) network; FIG. 2 illustrates the baseline user protocol stack for IAB in Rel-16; FIGS. 3A-3B illustrate the baseline control plane protocol stacks for IAB in Rel-16; FIG. 4 illustrates an example IAB node integration procedure; FIG. 5 illustrates an example of one-to-one mapping between User Equipment Data Radio Bearer (UE DRB) and Back Haul Radio Link Control-channel (BH RLC-channel); FIG. 6 illustrates an example of many-to-one mapping between UE DRBs and BH RLC-channel; FIG. 7 illustrates an example of IAB deployment in EN-DC mode; FIG. 8 illustrates an example wireless network, according to certain embodiments; FIG. 9 illustrates an example network node, according to certain embodiments; FIG. 10 illustrates an example wireless device, according to certain embodiments; FIG. 11 illustrate an example user equipment, according to certain embodiments; FIG. 12 illustrates a virtualization environment in which functions implemented by some embodiments may be virtualized, according to certain embodiments; FIG. 13 illustrates an example method by a network node, according to certain embodiments; FIG. 14 illustrates another exemplary virtual computing device, according to certain embodiments; FIG. 15 illustrates an example method by a network node, according to certain embodiments; and FIG. 16 illustrates another exemplary virtual computing device, according to certain embodiments. DETAILED DESCRIPTION Some of the embodiments contemplated herein will now be 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. Additional information may also be found in the document(s) provided in the Appendix. 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 following description. According to certain embodiments, methods, systems, and techniques are disclosed for the NR Donor gNB to exchange F1-AP signaling with the IAB node over the LTE radio using a solution where the whole SCTP/IP packets are delivered between the NR Donor gNB and IAB node. This approach can be used to deliver F1-AP signaling even when the NR link has been lost. By delivering the whole SCTP/IP packets, it is possible to still use the features provided by the SCTP/IP, such as: End to end SCTP guaranteed delivery, avoiding the need to support/specify LTE mechanism to handle the reliable delivery. SCTP multi-homing, ensuring seamless/loss-less switch to LTE when the NR link is lost Other SCTP functions such as duplication removal, QoS streams, in order delivery, . . . IP addressing mechanism allowing multiple SCTP connections Several mechanisms for delivering whole SCTP/IP packets (or IP PDUs) are considered and described in detail below, including: Mechanisms for sending the IP PDUs via X2-AP and RRC signaling (i.e., embedded the IP PDUs in X2/RRC signaling messages) over LTE radio. Mechanisms for the IAB node to setup a separated Packet Data Network (PDN) connection from the IAB node to the 4G EPC core over LTE radio. This PDN connection could be associated with an IP address belonging to the operator's own internal IP network. The IAB node can then use this PDN connection/IP address to setup an F1-AP/SCTP signaling connection to the Donor gNB. Mechanisms for the network to set up a special RLC-bearer or radio bearer (DRB) in the LTE eNB towards the IAB node over LTE radio. This special bearer can then be used for IP-based traffic between the IAB node and Donor gNB over LTE radio. On the hop between the LTE eNB and Donor gNB, it would be possible to setup a GTP tunnel associated with the bearer making it possible for the LTE eNB to map IP PDUs between the bearer over the radio and the GTP tunnel to/from the Donor gNB. According to certain embodiments, a mechanism is disclosed that makes it possible to exchange signaling between an IAB node and its donor gNB via LTE based using full IP packets. Certain embodiments may include one or more of: Sending the IP PDUs via X2-AP and RRC signaling (i.e., embedded the IP PDUs in X2/RRC signaling messages) over LTE radio. Setting up a separated PDN connection from the IAB node to the 4G EPC core over LTE radio. This PDN connection could be associated with an IP address belonging to the operator's own internal IP network. The IAB node can then use this PDN connection/IP address to setup an F1-AP/SCTP signaling connection to the Donor gNB. Setting up a special RLC-bearer or radio bearer (DRB) in the LTE eNB towards the IAB node over LTE radio. This special bearer can then be used for IP-based traffic between the IAB node and Donor gNB over LTE radio. On the hop between the LTE eNB and Donor gNB it would be possible to setup an GTP tunnel associated with the bearer making it possible for the LTE eNB to map IP PDUs between the bearer over the radio and the GTP tunnel to/from the Donor gNB. In addition, according to certain embodiments, mechanisms are introduced to handle IP assignments, setup of SCTP and/or F1 connection, and handling of nodes with different capabilities. According to certain embodiments, a method performed by a network node is disclosed. The method comprises sending, to another network node over LTE radio, one or more SCTP/IP packets. According to particular embodiments, the one or more SCTP/IP packets may comprise one or more whole SCTP/IP packets. In a particular embodiment, the one or more SCTP/IP packets may comprise IAB control plane signaling. In a particular embodiment, the one or more SCTP/IP packets may comprise F1-AP signaling. In a particular embodiment, the one or more SCTP/IP packets may be sent in the absence of an NR link. In a particular embodiments, the network node may be one of an NR Donor gNB and an IAB node. In a particular embodiments, the another network node may be one of an NR Donor gNB and an IAB node. According to certain embodiments, the method may further comprise obtaining an IP address allocated for use when communicating via LTE. In a particular embodiment, the IP address may be obtained using NAS signalling. In a particular embodiment, the IP address may be allocated by an OAM system. In a particular embodiment, obtaining the IP address may include: sending a message to the OAM system and receiving, in response to the message, configuration information indicating the allocated IP address. In a particular embodiment, the IP address may be allocated using Internet Engineering Task Force (IETF) specified methods comprising one or more of DHCP and Ipv6 host discovery. In a particular embodiment, the IP address may be obtained in an RRC message from an LTE eNB. In a particular embodiment, obtaining the IP address may include implicitly assigning the IP address using an IP address received in a DL packet. In a particular embodiment, the one or more SCTP/IP packets may include the allocated IP address. According to certain embodiments, the method may comprise setting up an SCTP connection to the another network node. In a particular embodiment, setting up the SCTP connection to the another network node may be performed in response to an indication from the another network node that a secondary SCTP connection is required. In a particular embodiment, setting up the SCTP connection to the another network node may be performed in response to a radio link failure. According to certain embodiments, the method may comprise sending capability information to one or more of the another node and an LTE node. In a particular embodiment, the method may comprise receiving capability information from one or more of the another node and the LTE node. According to certain embodiments, the method may comprise encrypting the one or more one or more SCTP/IP packets. In a particular embodiment, the one or more SCTP/IP packets may be encrypted using IPsec. In a particular embodiment, the one or more SCTP/IP packets may be sent via X2-AP and RRC signaling over LTE radio. In certain embodiments, the one or more SCTP/IP packets may be embedded in X2/RRC signaling messages. In a particular embodiment, the method may comprise: generating an F1-AP message; putting the F1-AP message into an SCTP packet; putting the SCTP packet in an IP PDU; putting the IP PDU in an RRC message; and sending the RRC message to an LTE node. In a particular embodiment, the RRC message may be an UL transfer message. In a particular embodiment, the one or more SCTP/IP packets may be sent via a separate PDN connection with a core network. In a particular embodiment, the method may comprise establishing the separate PDN connection with the core network using one or more NAS protocols. In a particular embodiment, the one or more SCTP/IP packets may be sent via one of an RLC-bearer and a radio bearer in an LTE eNB. In a particular embodiment, the one or more SCTP/IP packets may be sent via a GTP tunnel associated with the one of the RLC-bearer and the radio bearer. In a particular embodiment, the method may comprise: obtaining user data; and forwarding the user data to a host computer or a wireless device. In a particular embodiment, whole IP packets (including higher layers such as SCTP) are carried over the LTE radio between the IAB node and Donor gNB. To achieve this, one or more of the following aspects could be supported. IP Address Allocation It is possible to allocate one or more separate IP address(es) for the IAB node to be used when communicating via LTE. When the Donor gNB wants to send an IP packet(s) to the IAB node it would send the packets using one of the IAB addresses allocated for this purpose. The packet will then be routed via LTE. Similarly, when the IAB node wants to send an IP packet via LTE it would include the allocated IP address (the IAB address). Several mechanism may be used to allocate the IP address(es), including (but not limited to) those described below: It could be allocated using NAS signaling (e.g., when the IAB node registers or attaches to the LTE network). An advantage of this approach is that functionality in the network could be reused. It could be allocated by the OAM system serving the IAB node. For example, when the IAB nodes power on they may contact the OAM system and could in response receive configuration information. An advantage of this approach is that this functionality would only impact the OAM system and associated interfaces. It could be allocated using IETF specified methods such as DHCP, or IPv6 host discovery. In this case, a “logical channel” or L2 connection could be established in LTE which the IAB node uses to perform DHCP or IPv6 signaling. An advantage of this approach is that functionality in the network could be reused. This approach may also advantageously avoid core network impacts, reducing network costs/complexity. It could be explicitly assigned by the RRC layer (e.g., in an RRC message from the LTE eNB to the IAB node). An advantage of this approach is that it could also avoid core network impacts, reducing network costs/complexity. It could be implicitly assigned by the IAB using the same IP address as it receives in an DL packet. An advantage of this approach is that functionality in the network could be reused. As described above, the different approaches above have various pros and cons with regards to standard impacts, complexity and performance. Other pros and cons than mentioned above can also be considered. SCTP Setup and F1 Connection Setup/Association When the IAB node has been allocated one or more IP address(es) for sending IP packets via LTE, the IAB node can setup a SCTP connection to the Donor gNB (or Donor gNB-CU-CP function to be more exact). One possible approach is that this could be triggered by the Donor gNB sending an indication to the IAB node that a secondary SCTP connection (through LTE) is required. Another possible approach is that it could be triggered by the IAB losing the NR link (e.g., due to radio link failure). In certain embodiments, the SCTP connection via LTE can either be used immediately after setup to perform F1-AP signaling or, alternatively, the IAB signaling will start at a later stage (e.g., when the NR link is starting to experience problems). Capability-Related Aspects Not all IAB nodes and/or Donor gNB and/or LTE nodes may support the feature of exchanging F1 signaling via LTE as described herein. In order to support scenarios in which not all nodes support this feature, it is possible to exchange capability information between the involved nodes, making it possible to only use the feature when it is support by all or a sub set of the nodes. Examples of how this can be achieved include (but are not limited to) those described below. These examples can be used in combination or separately: The IAB node could indicate to the Donor gNB (e.g., Donor gNB-CU-CP) and/or LTE eNB that it supports the feature or that it supports it and wants to use it. The indication could be sent in an RRC or F1-AP message to Donor gNB. It could alternatively be included as a parameter in the UE radio access capabilities. The Donor gNB could indicate to the IAB node that it supports the feature or that it supports it and wants to use it. The indication could be sent in an RRC or F1-AP message to IAB node. It could alternatively be included in a broadcast message (e.g., as part of system information broadcast). The LTE eNB could indicate to the IAB node that it supports the feature or that it supports it and wants to use it. The indication could be sent in an RRC to IAB node. It could alternatively be included in a broadcast message (e.g., as part of system information broadcast). The LTE eNB could indicate to the Donor gNB that it supports the feature or that it supports it and wants to use it. The indication could be sent in an Xn or X2 message. The Donor gNB could indicate to the LTE eNB that it supports the feature or that it supports it and wants to use it. The indication could be sent in an Xn or X2 message. Using any one or more of the methods above, it would be possible for one node to know if the feature is supported in other nodes and only invoke feature related procedure in case it is supported on both sides. The Usage of IP Security (IP Sec) According to certain embodiments, the IP packets may be protected by IPsec operating, for example, in either tunnel mode or transport mode. In this case, the transmitting entity will encrypt the packet according to IPsec principle(s) and the receive node will decrypt the packet. Sending the F1 AP Signaling in IP PDUs Via X2-AP and RRC Signaling (i.e., Embedded the IP PDUs in X2/RRC Signaling Messages) Over LTE Radio. According to certain embodiments, the F1-AP signaling may be sent in IP PDUs via X2-AP and RRC signaling (i.e., embedded the IP PDUs in X2/RRC signaling messages) over LTE radio. This approach is based on sending the F1-AP signaling messages inside SCTP packets inside IP packets inside X2 and RRC messages. Below are some example procedures for IAB node sending an F1-AP message to the Donor gNB and vice versa. IAB Node=>Donor gNB: The procedure starts by the IAB node generating an F1-AP message. The message may be put inside an SCTP packet. The SCTP packet is put in an IP which is addressed towards the Donor DU. The IP PDU is then put inside an RRC message. In principle, any RRC message could be considered (e.g., the RRC UL transfer message). The actual ASN.1 coding used to transfer the IP PDU could use the OCTET STRING type as shown below, which is transparent to the RRC protocol machine (e.g., the RRC protocol machine will just past the content to higher layer): -- ASN1START TunneledIAB-Packet dbb7:9543:876a:299c:cd02:688e:141b:4026= OCTET STRING -- ASN1STOP The RRC message is then sent to the LTE eNB on one of the signaling radio bearers. When the LTE eNB receives the message, it will transparently forward the IP PDU to the NR gNB over X2 interface. The LTE eNB would know which node to forward the content to based on know which Secondary NR node the IAB node is connected. The IP PDU can be sent inside any X2 message such as X2-AP RRC TRANSFER or X2-AP SgNB Reconfiguration Completion. Again, the coding of the IP PDU could be to use the OCTET STRING type. When the gNB receives the IP PDU, it can send it to its own IP stack. From this step, the IP/SCTP/F1-AP packet could be decoded as the normal case when sending F1-AP over NR radio link. Donor gNB=>IAB Node: The procedure is similar to the procedure described above with the exception that the Donor gNB generates the F1-AP/SCTP/IP packets and then puts inside an X2-AP message and sends it to the LTE eNB for delivery to the IAB node. The LTE eNB puts the IP PDU into an RRC message. When the IAB node receives the RRC message it unpacks the PDU and sends it to the IP stack UE. Sending the F1-AP Signaling in IP PDUs Via a Separate PDN Connection. According to certain embodiments, the F1-AP signaling may be sent in IP PDUs via a separate PDN connection. This approach is based on that the IAB node setups up a PDU connection to the 4G or EPC core network. The signaling procedure to setup the connection used by IAB node could be based on signaling for UEs setting PDN connection (e.g., reusing the NAS protocols procedures). The following enhancements to the procedure for this case could be considered: The IAB node can provide an indication that it is an IAB node in one of the messages to the core network. This could be used by the core network to select a Packet Gateway (GW) which is responsible for supporting IP services between the RAN (e.g., Donor gNB) and IAB node. The subscription information stored in a home subscription register in the core network could include an indication that the IAB node is an IAB node, again making it possible for the core network (e.g., MME) to select the right packet GW (e.g., PDN GW). The CN could also provide an indication to a charging system or similar network element to enable different charging policies for IAB node signaling compared to normal end users. Once the separate PDN connection is established, the IAB node can use this connection to communicate with the Donor gNB. For example, it could setup SCTP/F1 connections and exchange F1-AP signaling messages. The IP address to be used for this connection could be allocated as part of the PDN connection setup signaling. Sending the F1-AP Signaling in IP PDUs Via a Special RLC Bearer According to certain embodiments, the F1-AP signaling may be sent in IP PDUs via a special RLC bearer. In this approach the network sets up a special RLC-bearer or data radio bearer in the LTE eNB towards the IAB node over LTE radio. This special bearer can then be used for IP based traffic between the IAB node and Donor gNB over LTE radio. The triggering to setup the bearer could be done in the LTE eNB (e.g., as a response to the IAB node connecting to the network). The bearer setup signaling can reuse parts of DRB signaling towards the IAB node. This bearer could, however, be different from a normal DRB in that it may not be required to setup Packet Data Convergence Protocol (PDCP) layers in the IAB node (e.g., only the RLC-bearer part is needed since the security protection of F1-AP signaling can be provided by the IP layer using, for example, IPsec, which is how F1 signaling is protected when using the NR link). On the hop between the LTE eNB and Donor gNB it would be possible to setup an GTP tunnel associated with the bearer making it possible for the LTE eNB to map IP PDUs between the bearer over the radio and the GTP tunnel to/from the Donor gNB. In this case, when the Donor gNB wants to send an F1-AP/SCTP/IP PDU to the IAB node over LTE radio it can send the packet inside a GTP/UDP/IP packet to the LTE eNB. The Donor gNB could send the packet using a Tunnel Endpoint ID (TEID) associated with the special bearer. In a particular embodiment, this GTP TEID will be allocated by the LTE eNB and then signaled to the Donor gNB using X2 signaling. In a particular embodiment, a different GTP tunnel could be used for UL packets from the IAB node to the Donor gNB. In that case, the TEID could be allocated by the gNB and then sent to the LTE eNB in X2 signaling. Over the radio interface the bearer can be associated with a logical channel identifier which separates the F1-AP signaling from other data or signaling sent to/from the IAB node. FIG. 8 illustrates a wireless network in accordance with some embodiments. 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 FIG. 1. For simplicity, the wireless network of FIG. 1 only depicts network 106, network nodes 160 and 160b, and wireless devices 110, 110b, and 110c. 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 160 and wireless device 110 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
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