Patent Publication Number: US-2023156561-A1

Title: Efficient multi-cell backhaul operation

Description:
TECHNICAL BACKGROUND 
     A wireless network, such as a cellular network, can include an access node (e.g., base station) serving multiple wireless devices or user equipment (UE) in a geographical area covered by a radio frequency transmission provided by the access node. As technology has evolved, different carriers within the cellular network may utilize different types of radio access technologies (RATs). RATs can include, for example, 3G RATs (e.g., GSM, CDMA etc.), 4G RATs (e.g., WiMax, Long Term Evolution (LTE), etc.), and 5G RATs (new radio (NR)). As wireless technology continues to improve, various different iterations of radio access technologies (RATs) may be deployed within a single wireless network. Such heterogeneous wireless networks can include newer 5G and millimeter wave (mm-wave) networks, as well as older legacy networks. 
     Further, as wireless device technology improves, relay nodes are being deployed to improve service quality by relaying communication between an access node, and wireless devices in the wireless network. For example, relay nodes may be used at the edge of a coverage area of an access node to improve coverage and/or service, as well as in crowded areas having a high number of other wireless devices to increase the available throughput to the wireless devices being relayed. Relay nodes are generally configured to communicate with the serving access node (i.e. a “donor” access node) via a wireless connection, and to deploy a wireless air interface to which end-user wireless devices can attach. A backhaul portion of the network comprises the intermediate links between the core network the small subnetworks at the edge of the network, such as the connections between the relay wireless devices and donor nodes 
     With the 5G RAT, a new backhaul option, Integrated Access and Backhaul (IAB) has been made available. IAB may be utilized to increase capacity in areas where fiber may be difficult to deploy. IAB can be utilized in cell sites that use wireless connectivity for both user traffic and backhaul. Cell sites implementing IAB technology do not add new capacity, but are able to share the capacity of a donor site across a larger coverage area. With 5G, the high frequencies of the Gigahertz spectrum have an inherent problem in that the shorter wavelengths have a dramatically smaller signal range and are far more susceptible to interference and degradation. Given that the effective distance of a 5G signal could be as little as 1,000 ft, the current design of 4G radio access networks (where the signal can reach up to 10 miles) becomes insufficient and IAB technology may be utilized to extend network reach. 
     Challenges associated with utilizing IAB technology include latency and lack of efficiency. Since the IAB technology uses multiple wireless links, existing protocols for IAB technology require different nodes to transmit in series to the donor node to minimize interference. Thus, an unintended latency is introduced. In operation, a donor node may act as a center pipe that carries its own data as well as data from other nodes. Thus, all data is transmitted through the donor node. Currently, all of the data is sent in a serial manner. 
     The problems set forth above negatively impact wireless device performance, particularly in dense or congested environments. Thus, a solution is needed for reducing latency and increasing efficiency in 5G networks utilizing IAB technology. 
     OVERVIEW 
     Exemplary embodiments described herein include systems, methods, and nodes for reducing latency and increasing efficiency. An exemplary method includes associating a corresponding unique code with multiple access nodes and multiplexing data with each of the corresponding unique codes. The method further includes transmitting the multiplexed data from each of the multiple access nodes to a donor node and assigning a unique donor code at the donor node. The method additionally includes multiplexing the unique donor code with donor node data and transmitting the multiplexed data from the multiple access nodes and the multiplexed donor node data in parallel from the donor node to a core network. In embodiments set forth herein, the method increases efficiency of multiple access nodes that employ integrated backhaul access (IAB) technology. 
     Exemplary embodiments further set forth herein include an access node comprising at least one processor programmed to perform multiple operations. The operations include associating a corresponding unique code with the multiple access nodes and receiving data in parallel from each of the multiple access nodes, the data multiplexed with the corresponding unique code for each of the multiple access nodes. The operations further include transmitting, in parallel, the multiplexed data from the multiple access nodes from the access node to a core network. 
     In a further exemplary embodiment, a method is provided for minimizing latency. The method includes associating a corresponding unique code with multiple access nodes utilizing integrated backhaul access (IAB) technology and transmitting data in parallel from each of the multiple access nodes to a donor node, the data multiplexed with the corresponding unique code for each of the multiple access nodes. The method further includes recognizing a data source at the donor node based on the corresponding unique code multiplexed with the data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    depicts an exemplary system for wireless communication, in accordance with the disclosed embodiments. 
         FIG.  2    illustrates an exemplary configuration of an access node in accordance with disclosed embodiments. 
         FIG.  3    depicts an IAB system architecture in accordance with disclosed embodiments. 
         FIG.  4    depicts access nodes within an IAB system architecture in accordance with the disclosed embodiments. 
         FIG.  5    depicts an exemplary method for low latency multi-cell backhaul operation in accordance with disclosed embodiments. 
         FIG.  6    depicts another exemplary method for low latency multi-cell backhaul operation in accordance with disclosed embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments described herein include systems, methods, access nodes for creating low latency backhaul operation. Thus, embodiments as set forth herein, provide improved access node capabilities for transmitting data between nodes in an efficient manner. Embodiments set forth herein may operate in various network environments. For example, the networks may include donor access nodes and relay nodes that are capable of communicating using a plurality of wireless air interfaces or RATs. For example, a donor access node can include a combination of a 4G evolved NodeB (eNodeB) and a 5G next generation NodeB (gNodeB). In other words, the access node can be configured to communicate using 4G LTE as well using 5G NR. In some embodiments, the donor access node can include a 4G eNodeB coupled to a plurality of 5G gNodeBs (one-to-many configuration). In similar embodiments, the donor access nodes can be selected from either the eNodeB or one of the 5G gNodeBs. Exemplary heterogeneous wireless networks described herein include donor access nodes and relay nodes that are capable of communicating using a plurality of wireless air interfaces or RATs. For example, a donor access node can include a combination of a 4G eNodeB and a 5G gNodeB. In other words, the access node can be configured to communicate using 4G LTE as well using 5G NR. 
     Embodiments as set forth herein expedite data transmission and processing by allowing parallel transmission of data. Parallel transmission is enabled by separating data originating from different access nodes so that the originating access node is easily identified. In embodiments set forth herein, a unique code is applied at each access node and multiplexed with the data originating at the access node. All types of access nodes may be equipped with the tools to generate a unique code, multiplex data with the unique code, and recognize codes from other access nodes. 
     In operation, multiple access nodes in a network may each generate a unique code, multiplex the unique code with data, and transmit the multiplexed data. In some embodiments, the multiple access node may transmit the respective multiplexed data to a single donor node functioning as a master node. Because the master node has the capability to identify the source of data based on the unique codes, the multiple access nodes are able to send data in parallel to the master node. Further, the multiple access nodes are able to use the same resource elements over the air to add efficiency. 
     In addition to recognizing the unique codes from the other access nodes, the master or donor node generates a unique code and multiplexes the unique code with data originating at the master node. Accordingly, the master node is able to transmit data originating at other access nodes and data originating at the master node to a core network in parallel. Thus, the master node acts as a centralized information transmitter for data from all other nodes. During transmission, the data from the multiple access nodes is separated by a scheme of codes. Embodiments described herein are particularly effective in high density areas, where a master access may interact with multiple secondary nodes. To achieve higher capacity, additional secondary or relay nodes can be incorporated. 
     The term “wireless device” refers to any wireless device included in a wireless network. For example, the term “wireless device” may include a relay node, which may communicate with an access node. The term “wireless device” may also include an end-user wireless device, which may communicate with the access node through the relay node. The term “wireless device” may further include an end-user wireless device that communicates with the access node directly without being relayed by a relay node. 
     The terms “transmit” and “transmission” in data communication may also encompass receive and receiving data. For example, “data transmission rate” may refer to a rate at which the data is transmitted by a wireless device and/or a rate at which the data is received by the wireless device. 
     An exemplary system described herein includes at least an access node (or base station), such as an eNodeB or a gNodeB), and a plurality of end-user wireless devices. For illustrative purposes and simplicity, the disclosed technology will be illustrated and discussed as being implemented in the communications between an access node (e.g., a base station) and a wireless device (e.g., an end-user wireless device). The disclosed technology is also be applied to communication between an end-user wireless device and other network resources, such as relay nodes, controller nodes, antennas, etc. Further, multiple access nodes may be utilized. For example, some wireless devices may communicate with an LTE eNodeB and others may communicate with an NR gNodeB. Other wireless devices may interact with both an eNodeB and a gNodeB. 
       FIG.  1    depicts an exemplary system  100  comprising a communication network  101 , gateway  102 , controller node  104 , access node  110 , relay nodes  140   a ,  140   b , and  140   c  and wireless devices  150 ,  152 ,  154 , and  156 . In this exemplary embodiment, access node  110  may be macrocell access nodes configured to deploy wireless air interfaces  130 ,  130   b ,  130   c , and  132  to which relay nodes  140   a - c  and other wireless devices  150  can attach and access network services from network  101 . Relay nodes  140   a - c  may be configured to communicate with access node  110  over wireless air interfaces  130   a ,  130   b , and  130   c , referred to as wireless backhaul, and are further configured to deploy additional wireless air-interfaces  160   a ,  160   b , and  160   c  to which wireless devices  152 ,  154 , and  156  can attach. Relay nodes  140   a - 140   c  are thus configured to relay data between a donor access node  110  and wireless devices  152 ,  154 , and  156  such that the wireless devices  152 ,  154 , and  156  may access network services using any one of relay nodes  140   a ,  140   b , and  140   c  rather than overload donor access node  110 , which may be serving numerous other devices, such as devices  150  over communication link  132 . Moreover, wireless devices that are outside a coverage area of access node  110  may access network services from donor access node  110  by virtue of being connected to one of relay nodes  140   a ,  140   b , and  140   c . Despite the limited number of nodes and end user devices shown, system  100  can include various other combinations of carriers/wireless air interfaces, antenna elements, access nodes, and wireless devices, as may be evident to those having ordinary skill in the art in light of this disclosure. 
     Further, access node  110  may be configured to deploy one or more wireless interfaces. For example, the access node  110  may include an eNodeB or gNodeB. Further the access node  110  may include wireless air interfaces using dual connectivity. For example, access node  110  can include a combination of an eNodeB and a gNodeB, such that each access node is be configured to deploy a wireless air interface using a first RAT (e.g. 4G LTE) and a second RAT (e.g. 5G NR). Each RAT can be configured to utilize a different frequency band or sub-band, a different channel size or bandwidth, and so on. For example, the 5G NR wireless air interface can be configured to utilize higher frequencies and larger channel bandwidths than the 4G LTE wireless air interface. Further, access node  110  can be configured to communicate using both RATs at the same time. For example, dual connections can be set up with any of relay nodes  140   a - c  using both 4G and 5G wireless air interfaces, with the 4G wireless air interface being used to transmit control information, and the 5G wireless air interface being used to transmit data information. In another example, either control or data transmissions may be transmitted using either 4G or 5G wireless air interface. In another example, a standalone 5G access node may be configured to deploy multiple 5G wireless air interfaces. Other implementations may be evident to those having ordinary skill in the art in light of this disclosure. 
     A processing node within system  100  (for example, communicatively coupled to access node  110  or any other network node) can be configured to perform operations for allocating wireless air interface resources to relay nodes  140   a - c  by identifying relay nodes  140   a - c  as being within range of donor access node  110 . Identifying relay nodes  140   a - c  may be based on receipt of a request from each relay node  140   a - c . 
     Access node  110  can be any network node configured to provide communication between relay nodes  140   a ,  140   b , and  140   c  (and end-user wireless devices  152 ,  154 , and  156  attached thereto) and communication network  101 , including standard access nodes such as a macro-cell access node, base transceiver station, a radio base station, an eNodeB device, an enhanced eNodeB device, a gNodeB device (gNodeB) in 5G networks, or the like. In an exemplary embodiment, a macro-cell access node can have a coverage area in the range of approximately five kilometers to thirty-five kilometers and an output power in the tens of watts. Alternatively, access node  110  may comprise any short range, low power, small-cell access node such as a microcell access node, a picocell access node, a femtocell access node, or a home eNodeB/gNodeB device. 
     Access node  110  can comprise a processor and associated circuitry to execute or direct the execution of computer-readable instructions to perform operations such as those further described herein. Briefly, access node  110  can retrieve and execute software from storage, which can include a disk drive, a flash drive, memory circuitry, or some other memory device, and which can be local or remotely accessible. The software comprises computer programs, firmware, or some other form of machine-readable instructions, and may include an operating system, utilities, drivers, network interfaces, applications, or some other type of software, including combinations thereof. Further, access node  110  can receive instructions and other input at a user interface. Access node  110  communicates with gateway node  102  and controller node  104  via communication link  106 . Access node  110  may communicate with each other, and other access nodes (not shown), using a wireless link or a wired link such as an X2 link. Components of exemplary access node  110  and processing nodes coupled thereto are further described with reference to  FIGS.  2  and  4   . 
     Wireless devices  150 ,  152 ,  154 , and  156  may be any device, system, combination of devices, or other such communication platform capable of communicating wirelessly with relay nodes  140   a ,  140   b , and  140   c  and/or access node  110  using one or more frequency bands deployed therefrom. Wireless devices  150 ,  152 ,  154 , and  156  may be, for example, a mobile phone, a wireless phone, a wireless modem, a personal digital assistant (PDA), a voice over internet protocol (VoIP) phone, a voice over packet (VOP) phone, or a soft phone, as well as other types of devices or systems that can send and receive audio or data. Other types of communication platforms are possible. 
     Communication network  101  can be a wired and/or wireless communication network, and can comprise processing nodes, routers, gateways, and physical and/or wireless data links for carrying data among various network elements, including combinations thereof, and can include a local area network a wide area network, and an internetwork (including the Internet). Communication network  101  can be capable of carrying data, for example, to support voice, push-to-talk, broadcast video, and data communications by wireless devices  150 ,  152 ,  154 , and  156 . Wireless network protocols can comprise MBMS, code division multiple access (CDMA) 1xRTT, Global System for Mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), High-Speed Packet Access (HSPA), Evolution Data Optimized (EV-DO), EV-DO rev. A, Third Generation Partnership Project Long Term Evolution (3GPP LTE), Worldwide Interoperability for Microwave Access (WiMAX), Fourth Generation broadband cellular (4G, LTE Advanced, etc.), and Fifth Generation mobile networks or wireless systems (5G, 5G New Radio (“5G NR”), or 5G LTE). Wired network protocols that may be utilized by communication network  101  comprise Ethernet, Fast Ethernet, Gigabit Ethernet, Local Talk (such as Carrier Sense Multiple Access with Collision Avoidance), Token Ring, Fiber Distributed Data Interface (FDDI), and Asynchronous Transfer Mode (ATM). Communication network  101  can also comprise additional base stations, controller nodes, telephony switches, internet routers, network gateways, computer systems, communication links, or some other type of communication equipment, and combinations thereof. 
     Communication link  106  can use various communication media, such as air, space, metal, optical fiber, or some other signal propagation path - including combinations thereof. Communication link  106  can be wired or wireless and use various communication protocols such as Internet, Internet protocol (IP), local-area network (LAN), S1, optical networking, hybrid fiber coax (HFC), telephony, T1, or some other communication format - including combinations, improvements, or variations thereof. Wireless communication links can be a radio frequency, microwave, infrared, or other similar signal, and can use a suitable communication protocol, for example, Global System for Mobile telecommunications (GSM), Code Division Multiple Access (CDMA), Worldwide Interoperability for Microwave Access (WiMAX), Long Term Evolution (LTE), 5G NR, or combinations thereof. Other wireless protocols can also be used. Communication link  106  can be direct links or might include various equipment, intermediate components, systems, and networks, such as a cell site router, etc. Communication link  106  may comprise many different signals sharing the same link. Communication link  106  may be associated with many different reference points, such as N1-Nxx, as well as S1-Sxx, etc. 
     Gateway node  102  can be any network node configured to interface with other network nodes using various protocols. Gateway node  102  can communicate user data over system  100 . Gateway node  102  can be a standalone computing device, computing system, or network component, and can be accessible, for example, by a wired or wireless connection, or through an indirect connection such as through a computer network or communication network. For example, gateway node  102  can include a serving gateway (SGW), a public data network gateway (PGW), and/or a systems architecture evolution gateway (SAE-GW) associated with 4G LTE networks, or a user plane function (UPF) associated with 5G NR networks. One of ordinary skill in the art would recognize that gateway node  102  is not limited to any specific technology architecture, such as Long Term Evolution (LTE) or 5G NR, and can be used with any network architecture and/or protocol. 
     Gateway node  102  can comprise a processor and associated circuitry to execute or direct the execution of computer-readable instructions to obtain information. Gateway node  102  can retrieve and execute software from storage, which can include a disk drive, a flash drive, memory circuitry, or some other memory device, and which can be local or remotely accessible. The software comprises computer programs, firmware, or some other form of machine-readable instructions, and may include an operating system, utilities, drivers, network interfaces, applications, or some other type of software, including combinations thereof. Gateway node  102  can receive instructions and other input at a user interface. 
     Controller node  104  can be any network node configured to communicate information and/or control information over system  100 . Controller node  104  can be a standalone computing device, computing system, or network component, and can be accessible, for example, by a wired or wireless connection, or through an indirect connection such as through a computer network or communication network. For example, controller node  104  can include a mobility management entity (MME), a control gateway (SGW-C or PGW-C), a session management function (SMF), access and mobility function (AMF), a home subscriber server (HSS), a policy control and charging rules function (PCRF), an authentication, authorization, and accounting (AAA) node, a rights management server (RMS), a subscriber provisioning server (SPS), a policy server, etc. One of ordinary skill in the art would recognize that controller node  104  is not limited to any specific technology architecture, such as Long Term Evolution (LTE) or 5G NR, and can be used with any network architecture and/or protocol. 
     Controller node  104  can comprise a processor and associated circuitry to execute or direct the execution of computer-readable instructions to obtain information. Controller node  104  can retrieve and execute software from storage, which can include a disk drive, a flash drive, memory circuitry, or some other memory device, and which can be local or remotely accessible. In an exemplary embodiment, controller node  104  includes a database  105  for storing information related to components of system  100 , such as capabilities of relay nodes  140   a ,  140   b  and  140   c  and end-user wireless devices attached thereto, and so on. This information may be requested by or shared with access node  110  via communication links  106 ,  107 , X2 connections, and so on. The software comprises computer programs, firmware, or some other form of machine-readable instructions, and may include an operating system, utilities, drivers, network interfaces, applications, or some other type of software, and combinations thereof. Further, controller node  104  can receive instructions and other input at a user interface. 
     The access node  110  may also connect via fiber  170  to a core  108 , which may, for example, be a 5G core  108 . The communication network  101 , the access node  110  and/or the 5G core  108  may collectively implement several control plane network functions (NFs) and user plane NFs. The control plane NFs include but are not limited to a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), an Application Function (AF), a Short Message Service Function (SMSF), a Core Access and Mobility management Function (AMF), a Session Management Function (SMF), and an Authentication Server Function (AUSF). The user plane NFs include but are not limited to a Unified Data Repository (UDR) and a UPF. Control plane NFs can provide one or more NFs based on a request-response or subscribe-notify model. The NFs may form a micro services-based architecture, which may include network functions distributed over different cloud infrastructures. Additionally, many services may span different network functions and domains that work in unison. 
     The NRF maintains the list of available network functions and their profiles. The NRF maintains an updated repository of the network components along with services provided by each of the elements in the core network. The NRF additionally provides a discovery mechanism that allows the elements to discover each other. The NRF provides a registration function that allows each network function to register a profile and a list of services with the NRF. It also performs services registration and discovery so that different network functions can find each other. As one example, the SMF, which is registered to NRF, becomes discoverable by the AMF when a UE or other device tries to access a service type served by the SMF. The NRF broadcasts available services once they are registered in the 5G core  108 . To use other network functions, registered functions can send service requests to the NRF. 
     The UDM interfaces with NFs such as AMF and SMF so that relevant data becomes available to AMF and SMF. The UDM generates authentication vectors when requested by the AUSF, which acts as an authentication server. The AMF performs the role of access point to the 5G core  108 , thereby terminating RAN control plane and UE traffic originating on either the N1 or N2 reference interface. In the 5G core  108 , the functionality of the 4G Mobility Management Entity (MME) is decomposed into the AMF and the SMF. The AMF receives all connection and session related information from the UE using N1 and N2 interfaces, and is responsible for handling connection and mobility management tasks. 
     The UDR may provide unified data storage accessible to both control plane NFs and user plane NFs. Thus, the UDR may be a repository shared between control plane NFs and the UPF. The UDR may include information about subscribers, application-specific data, and policy data. The UDR can store structured data that can be exposed to an NF. The UPF may perform operations including, but not limited to, packet routing and forwarding, packet inspection, policy enforcement for the user plane, Quality-of-Service (QoS) handling, etc. When compared with 4G EPC, the functions of the UPF may resemble those of the SGW-U (Serving Gateway User Plane function) and PGW-U (PDN Gateway User Plane function). 
     Other network elements may be present in system  100  to facilitate communication but are omitted for clarity, such as base stations, base station controllers, mobile switching centers, dispatch application processors, and location registers such as a home location register or visitor location register. Furthermore, other network elements that are omitted for clarity may be present to facilitate communication, such as additional processing nodes, routers, gateways, and physical and/or wireless data links for carrying data among the various network elements, e.g. between access node  110  and communication network  101 . 
     Further, the methods, systems, devices, networks, access nodes, and equipment described herein may be implemented with, contain, or be executed by one or more computer systems and/or processing nodes. The methods described above may also be stored on a non-transitory computer readable medium. Many of the elements of communication system  100  may be, comprise, or include computers systems and/or processing nodes. This includes, but is not limited to: access node  110 , relay nodes  140   a ,  140   b , and  140   c , gateway(s)  102 , controller node  104 , and/or network  101 . 
       FIG.  2    illustrates one example of an access node  200 , which may correspond to one or more of the access nodes  110  and  140   a ,  140   b , and  140   c  shown in  FIG.  1   . As illustrated the access node  200  includes a controller  210 , a memory  220 , wireless communication circuitry  230 , and a bus  240  through which the various elements of the access node  200  communicate with one another. As illustrated, the controller  210  includes sub-modules or units, each of which may be implemented via dedicated hardware (e.g., circuitry), software modules which are loaded from the memory  220  and processed by the controller  210 , firmware, and the like, or combinations thereof. These sub-modules or units include a logic processor  211  (e.g., logic circuitry or a logic program) configured to perform various settings and/or determinations and a code management processor  212  (e.g., code management circuitry or a code management program) configured to perform various code management functions. 
     The logic processor  211  may be configured to perform one or more operations including determining a signal origin based on received multiplexed data. Thus, the logic processor may be configured to demultiplex data. The signal origin may be, for example, one of the access nodes shown in  FIG.  1   . The logic processor  211  may further be configured to schedule transmission of signals. 
     The code management processor  212  may be configured to generate codes, identify codes, and multiplex codes with data for transmission. For example, the code management unit  212  may instruct the access node  200  to multiplex a communication signal with an orthogonal code (e.g., a code division multiplex (CDM) code) prior to transmitting the communication signal (e.g., to the connected wireless device or to a core network) The code management processor  212  may also instruct the recipient device (either the connected wireless device, the access node  200 , or a core network) to separate the communication signal that has been multiplexed with the orthogonal code from signals that have not been multiplexed with the orthogonal code. The code management processor  212  may also instruct the recipient device to separate the orthogonal code from the received communication signal. The code management processor  212  may alternatively be configured to instruct the neighboring access node (rather than the access node  200  itself) to implement the multiplexing and demultiplexing procedures. These and other instructions may be performed in response to a determination (e.g., by the logic processor  211 ) that a signal multiplexed with a code has been received or transmitted. 
     In this manner, the wireless device and/or access node may be capable of distinguishing communications (e.g., between the access nodes  110  and  140   a ,  140   b , and  140   c  of  FIG.  1   ) from extraneous communications even if those communications occupy the same or similar frequencies in the same link direction for one or more time slots. 
     The logic processor  211  and/or the code management processor  212  may physically reside within the controller  210 , or may be virtual structures operable to control other components of the access node  200  to implement the above operations. For example, the code management processor  212  may be configured to itself multiplex the communication signal with the orthogonal code, or may be configured to provide a control signal to the wireless communication circuitry  230  thereby to cause the wireless communication circuitry  230  to multiplex the communication signal with the orthogonal code. Moreover, one or more of the units may instead reside within the memory  220  and/or may be provided as separate units within the access node  200 . Moreover, while the logic processor  211  and the code management processor  212  are illustrated as separate units, in practical implementations some or all of the units may be combined and/or share components. 
     The wireless communication circuitry  230  may include circuit elements configured for inbound communication to receive wireless signals (e.g. one or more antennas) as well as interface elements configured, for example, to translate data signals from wireless input into control or other signals for the controller  210 . Moreover, the wireless communication circuitry  230  may include circuit elements configured for outbound communication to generate wireless signals (e.g., one or more antennas) as well as interface elements configured, for example, to translate control signals from the controller  210  into data signals for wireless output. For example, the access node  200  may be configured to receive connection requests via the wireless communication circuitry  230  and output connection determinations via the wireless communication circuitry  230 , thereby allowing or denying the connection requests. The access node  200  may include additional wireless communication circuitry elements, for example to communicate using additional frequencies and/or to provide connectivity for different RATs. The access node  200  may further include additional wired communication circuitry elements. 
       FIG.  3    illustrates an IAB system architecture  300  implementing embodiments herein. IAB specifications define two antenna system types including an IAB node  310 A,  310 B, and  310 C and an IAB donor node  320 . IAB donor  320  terminates the backhaul traffic from distributed IAB nodes  310 A,  310 B, and  310 C. The nodes  310 A,  310 B, and  310 C can be backhaul endpoints or relays between those endpoints and the donor  320 . Both IAB donor  320  and nodes  310 A,  310 B, and  310 C may serve wireless devices  360 ,  362 , and  364 . 
     Thus, the system architecture  300  includes multiple IAB nodes  310 A,  310 B, and  310 C, which communicate with a core network  350  through an IAB donor node  320 . Further, multiple wireless devices  360 ,  362 , and  364  communicate with IAB nodes  310 A,  310 B, and  310 C respectively through wireless access links  330 ,  334 , and  340 . The IAB nodes  310 A,  310 B, and  310 C communicate with the IAB donor node  320  over wireless backhaul links  332 ,  336 , and  338 . The IAB donor node  320  connects to a core network  350  via a wired non-IAB backhaul  342 , which may be high capacity fiber. It should be noted that although only three IAB nodes are shown, IAB nodes can be backhauled to the donor node through more than one intermediate IAB node and thus, multi-hop backhauling is supported in IAB. IAB nodes  310 A,  310 B, and  310 C do not add new capacity. They instead share the capacity of the donor site  320  efficiently across a much larger coverage area. 
     As shown, the architecture provides for multi-hop deployments. For example, IAB node  310 A may behave as a donor for IAB node  310 B. Though not shown, each IAB node could connect to multiple sites or IAB nodes, thus, providing redundancy. IAB nodes are transparent to devices so that devices connect to IABs just as they would to any regular base stations. IAB technology leverages spectral efficiencies of NR and increased capacity afforded by the higher bands available to deliver an alternative to optical cell site backhaul . IAB allows for multi-hop backhauling using the same frequencies employed for user equipment (UE) access or alternatively using a distinct, dedicated, frequency. 
       FIG.  4    illustrates a more detailed configuration  400  of a donor node  420  and IAB nodes  430  and  440  connected to a 5G core  410 . In the displayed embodiment, IAB technology is implemented in a decomposed radio access network (RAN) model, such as open RAN (O-RAN), which decouples a distributed unit (DU) from a central unit (CU). The O-RAN includes multiple disaggregated components, such as a RAN Intelligent Controller (RIC), centralized unit (CU), distributed unit (DU), and radio unit (RU). The CU generally is centralized so as to control the operation of several DUs. The DUs are distributed to as to be closer to radio units (RUs) may in some instances be integrated with the RUs. 
     As is shown below, a CU  422  is incorporated into the donor node  420 , but is not necessary in the IAB nodes  430  and  440 . In embodiments set forth herein, a single IAB system of one or more IAB nodes  430  and  440  and the IAB donor node  420  may, together, deemed a single gNB. 
     As illustrated, the donor node  420  is connected with the IAB nodes  430  and  440 . The donor node  420  may include a centralized unit (CU)  422  and a distributed unit (DU)  424 . Although not shown, the donor node  420  may include more than one DU  424 . The CU  422  is the centralized unit that runs the Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) layers. The donor node  420  includes the CU  422  and one DU  424 , which is connected to the CU  422  by different interfaces for the control plane and user plane. In some instances, CU  422  may interface with and control the operation of multiple DUs to support multiple gNBs. The split architecture enables a 5G network to utilize different distribution of protocol stacks between CU and DUs depending on mid-haul availability and network design. The CU  422  is a logical node that includes the gNB functions like transfer of user data, mobility control, RAN sharing, positioning, etc. 
     The DU  424  includes the Radio Link Control (RLC), Medium Access Control (MAC), and Physical layer (PHY) protocols. The interface between CU and DU is standardized as F1 interface, which defines the higher layer protocols. It should be understood that the DU  424  includes hardware components, such as a processor and memory. 
     The IAB node  430  may include a DU  432 , substantially similar to the DU described above, as well as an IAB Mobile Termination (MT) antenna  434  The IAB-MT  434  may be an independent set of arrays. The IAB node  440  may include a DU  442  and virtual IAB-MT (vIAB-MT)  444 . The vIAB-MT  444  shares the same antennas used for access as shared frequency and combined radio unit implementations may be more efficient than the decoupled alternatives 
     The IAB nodes  430  and  440  rely on IAB for backhauling and provide service for UEs and IAB nodes via the DU functionality. The MTs associate with the DU of the parent IAB node or IAB donor  420 . The message transmission is based on the lower layer functionality provided by the link between the IAB node MTs  434  and  444  and the parent node DU  424 . The IAB nodes  430  and  440  can be backhauled to the IAB donor  420  through more than one intermediate IAB node, implying that multi-hop backhauling is supported in the IAB network. Further, the displayed configuration is merely exemplary, as any number of IAB nodes with either IAB-MTs or vIAB-MTs may be provided 
     The disclosed methods for low latency multi-cell backhaul operations are further discussed with reference to  FIGS.  5  and  6   .  FIG.  5    illustrates an exemplary method  500  for low latency multi-cell backhaul operation in accordance with disclosed embodiments. The steps illustrated in  FIG.  5    may be performed by any suitable processor discussed herein, for example, a processor included in access node  110 ,  140   a - c ,  200 ,  310   a - c ,  320  or processor included in controller node  104 . For discussion purposes, as an example, method  500  is described as being performed by a processor included in access nodes  310 A and  320 . 
     Method  500  starts in step  510  when the access node  310 A associates with a unique code. In embodiments provided herein, the access node  310 A generates or stores a unique code for use. The code may be generated by the code management processor  212  shown in  FIG.  2   . Alternatively, the code may be generated by a donor node or controller node and provided to the access node  310 A. In embodiments provided herein, the code is a CDMA code, such that it is orthogonal to other codes in the network. Other coding schemes that may be utilized to prevent interference and lower latency are within the scope of the disclosure. 
     At step  520 , the access node  310 A multiplexes the unique code with data originating at the access node  310 A. At step  530 , the access node  310 A transmits the multiplexed data to the donor node  320 . The transmission of step  320  may be accomplished, for example with an IAB-MT or a vIAB-MT such as those shown in  FIG.  4   . In embodiments set forth herein, the transmission is made to a DU of the donor node  320 . 
     At step  540 , the donor node  320  multiplexes data originating at the donor node with a unique donor code. The unique donor code may be generated by or retrieved from storage by a code management processor of the donor node  320 . The donor code is configured to distinguish data sent from the donor node from the data sent from the IAB node  310 A. Thus, in embodiments provided herein, the unique donor code is orthogonal to the IAB node code multiplexed by the IAB node  310 . 
     In step  550 , the donor node  320  transmits the multiplexed data from step  540  simultaneously with the multiplexed data from the IAB node to the core network. The codes enable the data to be sent in parallel without interference. Further, the uplink communications may be demultiplexed (i.e., separated) upon receipt by the core network. The method as illustrated in  FIG.  5    may be performed continuously or in response to changes in a network that create a possibility of interference. 
       FIG.  6    illustrates an additional method for low latency multi-cell backhaul operation. The steps illustrated in  FIG.  6    may be performed by any suitable processor discussed herein, for example, may be performed by any suitable processor discussed herein, for example, a processor included in access node  110 ,  140   a - c ,  200 ,  310   a - c ,  320  or processor included in controller node  104 . For discussion purposes, as an example, method  500  is described as being performed by a processor included in access nodes  310 A-C and  320 . 
     In step  610 , multiple IAB nodes  310 A,  310 B, and  310 C generate or retrieve unique codes. The nodes  310 A,  310 B, and  310 C may utilize a code management processor, such as that shown in  FIG.  2   . Each of the codes from  310 A,  310 B, and  310 C may be CDMA codes that are orthogonal to one another. The codes may be generated or stored and retrieved for use by a code management processor at each node. Other unique codes that distinguish the three nodes as sources of information, minimize interference and lower latency are also within scope of the disclosure. While step  610  is described as one step, the codes may be generated at the same or different times. 
     In step  620 , each of the nodes  310 A,  310 B, and  310 C multiplexes its respective unique code with data for transmission and in step  630 , the nodes transmit the multiplexed data in parallel to the donor node  320  and step  630 , the nodes  310 A,  310 B, and  310 C transmit the multiplexed data to the donor node  320  in parallel. Because the data is separated by the unique code, the donor node  320  is able to identify the source of each transmission upon receipt of the multiplexed data. 
     In step  640 , the donor node  320  multiplexes data originating at the donor node  320  with a unique donor code. The donor node  320  may generate or retrieve the unique donor code using, for example, the code management processor  212 . 
     Finally, in step  650 , the donor node  320  transmits the multiplexed data from both the donor node  320  and all of the multiple access nodes  310 A,  310 B and  310 C to a core network in parallel. The core network can distinguish between data sources based on the unique codes and is capable of demultiplexing received data. 
     In some embodiments, methods  500  and  600  may include additional steps or operations. Furthermore, the methods may include steps shown in each of the other methods. As one of ordinary skill in the art would understand, the methods  500  and  600  may be integrated in any useful manner. Additionally, in order to optimize the network, the methods disclosed may be performed for multiple access node devices in the network. 
     In addition to the systems and methods described herein, the operations of performing low latency multi-cell backhauling may be implemented as computer-readable instructions or methods, and processing nodes on the network for executing the instructions or methods. The processing node may include a processor included in the access node or a processor included in any controller node in the wireless network that is coupled to the access node. 
     The exemplary systems and methods described herein may be performed under the control of a processing system executing computer-readable codes embodied on a computer-readable recording medium or communication signals transmitted through a transitory medium. The computer-readable recording medium may be any data storage device that can store data readable by a processing system, and may include both volatile and nonvolatile media, removable and non-removable media, and media readable by a database, a computer, and various other network devices. 
     Examples of the computer-readable recording medium include, but are not limited to, read-only memory (ROM), random-access memory (RAM), erasable electrically programmable ROM (EEPROM), flash memory or other memory technology, holographic media or other optical disc storage, magnetic storage including magnetic tape and magnetic disk, and solid state storage devices. The computer-readable recording medium may also be distributed over network-coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. The communication signals transmitted through a transitory medium may include, for example, modulated signals transmitted through wired or wireless transmission paths. 
     The above description and associated figures teach the best mode of the invention. The following claims specify the scope of the invention. Note that some aspects of the best mode may not fall within the scope of the invention as specified by the claims. Those skilled in the art will appreciate that the features described above can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific embodiments described above, but only by the following claims and their equivalents.