PATENT DOCUMENT

Publication Number: US-11871375-B2
Application Number: US-201816615337-A
Country: US
Kind Code: B2

Title: Devices and methods for flow-control triggering and feedback

Abstract:
Devices, methods, communication nodes, base stations, storage media, and other embodiments are provided for managing associations in a communication network. In one example embodiment, a New Radio (NR) node is configured for NR user-plane protocol communications between a master node (MN) and a secondary node (SN). The NR node is configured to generate a downlink (DL) user data message with downlink user data, initiate transmission of the DL user data message to a second node, and process a DL data delivery status message from the second node in response to the DL user data message. In various embodiments, polling and SCG split-bearer configurations are supported by such messaging. In some embodiments, packet data convergence protocol (PDCP) serial numbers are communicated for transmission and retransmission management. In some embodiments, DL configurations initiated by and SN are enabled, as well as UL configurations initiated by either an MN or an SN.

Claims:
What is claimed is: 
     
       1. An apparatus comprising:
 at least one processor configured to cause a New Radio (NR) node to:
 generate a first data message; 
 initiate transmission of the first data message to a second node; and 
 process a second message from the second node, wherein a bit in an initial octet of the second message indicates the existence of a highest successfully delivered packet data convergence protocol (PDCP) protocol data unit (PDU) sequence number (SN) in the second message, and when the bit is set to ‘1’, said processing includes processing the highest successfully delivered PDCP PDU SN in the second message. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the NR node comprises a secondary node and wherein the second node comprises a master node. 
     
     
       3. The apparatus of  claim 1 , wherein the first data message comprises a DL user data message comprising DL user data, wherein the DL user data comprises the highest successfully delivered PDCP PDU SN. 
     
     
       4. The apparatus of  claim 3 , wherein the DL user data message comprises a DL discard field based on the highest successfully delivered PDCP PDC SN indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     
     
       5. The apparatus of  claim 1 , wherein the NR node comprises a node hosting NR PDCP operations, and the second node comprises a corresponding node. 
     
     
       6. The apparatus of  claim 5 , wherein the at least one processor is further configured to:
 access flow control data; 
 generate a flow control configuration update using the flow control data; 
 initiate transmission of the flow control configuration update to the second node; and 
 process a flow control configuration update acknowledgement from the second node. 
 
     
     
       7. The apparatus of  claim 6 , wherein the flow control data comprises a report polling parameter. 
     
     
       8. The apparatus of  claim 7 , wherein the report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     
     
       9. The apparatus of  claim 5 , wherein the first message comprises a first PDU type and the second message comprises a second PDU type. 
     
     
       10. The apparatus of  claim 1 , wherein the second message comprises a parameter indicating a highest retransmitted NR PDCP sequence number. 
     
     
       11. The apparatus of  claim 10 , wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     
     
       12. A non-transitory computer readable storage medium comprising instructions that, when executed by one or more processors of a New Radio (NR) node, cause the one or more processors to:
 generate a first data message; 
 initiate transmission of the first data message to a second node; and 
 process a second message from the second node, wherein a bit in an initial octet of the second message indicates the existence of a highest successfully delivered packet data convergence protocol (PDCP) protocol data unit (PDU) sequence number (SN) in the second message, and when the bit is set to ‘1’, said processing includes processing the highest successfully delivered PDCP PDU SN in the second message. 
 
     
     
       13. The non-transitory computer readable storage medium of  claim 12 , wherein the NR node comprises a secondary node and wherein the second node comprises a master node. 
     
     
       14. The non-transitory computer readable storage medium of  claim 13 , wherein the first data message comprises a DL user data message comprising DL user data, wherein the DL user data comprises the highest successfully delivered PDCP PDU SN. 
     
     
       15. The non-transitory computer readable storage medium of  claim 14 , wherein the DL user data message comprises a DL discard field based on the highest successfully delivered PDCP PDU SN indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     
     
       16. The non-transitory computer readable storage medium of  claim 12 , wherein the instructions further configured the one or more processors to:
 access flow control data; 
 generate a flow control configuration update using the flow control data; 
 initiate transmission of the flow control configuration update to the second node; and 
 process a flow control configuration update acknowledgement from the second node. 
 
     
     
       17. The non-transitory computer readable storage medium of  claim 16 , wherein the flow control data comprises a report polling parameter, and wherein the report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     
     
       18. The non-transitory computer readable storage medium of  claim 12 , wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     
     
       19. The non-transitory computer readable storage medium of  claim 18 , wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number; and
 wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
 
     
     
       20. A method for operating a New Radio (NR) node, comprising:
 by the NR node:
 generating a first data message; 
 initiating transmission of the first data message to a second node; and 
 processing a second message from the second node, wherein a bit in an initial octet of the second message indicates the existence of a highest successfully delivered packet data convergence protocol (PDCP) protocol data unit (PDU) sequence number (SN) in the second message, and when the bit is set to ‘1’, said processing includes processing the highest successfully delivered PDCP PDU SN in the second message. 
 
 
     
     
       21. The method of  claim 20 , wherein the first data message comprises a DL user data message comprising DL user data, wherein the DL user data comprises the highest successfully delivered PDCP PDU SN indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     
     
       22. The method of  claim 20 , further comprising:
 accessing flow control data; 
 generating a flow control configuration update using the flow control data; 
 initiating transmission of the flow control configuration update to the second node; and 
 processing a flow control configuration update acknowledgement from the second node. 
 
     
     
       23. The method of  claim 20 , wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     
     
       24. A New Radio (NR) node, comprising:
 communication circuitry; and 
 at least one processor coupled to the communication circuitry, wherein the at least one processor is configured to cause the NR node to:
 generate a first data message; 
 initiate transmission of the first data message to a second node; and 
 process a second message from the second node, wherein a bit in an initial octet of the second message indicates the existence of a highest successfully delivered packet data convergence protocol (PDCP) protocol data unit (PDU) sequence number (SN) in the second message, and when the bit is set to ‘1’, said processing includes processing the highest successfully delivered PDCP PDU SN in the second message. 
 
 
     
     
       25. The NR node of  claim 24 , wherein the first data message comprises a DL user data message comprising DL, user data, wherein the DL user data comprises the highest successfully delivered PDCP PDU SN indicating a sequence number up to and including, which all NR PDCP PDUs should be discarded by the second node. 
     
     
       26. The NR node of  claim 24 , wherein the at least one processor is further configured to:
 access flow control data; 
 generate a flow control configuration update using the flow control data; 
 initiate transmission of the flow control configuration update to the second node; and 
 process a flow control configuration update acknowledgement from the second node. 
 
     
     
       27. The NR node of  claim 24 , wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number; and
 wherein the second message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number.

Description:
PRIORITY CLAIM 
     This application is a U.S. National Stage Filing under 35 U.S.C. 371 from International Application No. PCT/US2018/038501, filed Jun. 20, 2018 and published in English as WO 2018/237001 on Dec. 27, 2018, which claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 62/522,557, filed Jun. 20, 2017, and titled “ENHANCING NETWORK FLOW CONTROL TRIGGERING AND FEEDBACK” and U.S. Provisional Patent Application Ser. No. 62/522,515, filed Jun. 20, 2017, and titled “ENHANCING NETWORK FLOW CONTROL TRIGGERING AND FEEDBACK,” which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments pertain to systems, methods, and component devices for wireless communications, and particularly to device access and associated operations in Third Generation Partnership Project (3GPP) communication systems. 
     BACKGROUND 
     Long-term evolution (LTE) and LTE-Advanced are standards for wireless communication information (e.g., voice and other data) for user equipment (UE) such as mobile telephones. Such systems operate with UEs communicating with a network via cells of radio access technology (RAT) systems with radio area networks (RANs) which may include base station systems such as evolved node Bs (eNBs) or next-generation node Bs (gNBs) for providing an initial wireless connection to the larger system. As part of managing connections between the system and UEs, network systems may manage persistence control of associations with RAN devices and UEs. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG.  1    is a diagram of a wireless network, in accordance with some embodiments. 
         FIG.  2    describes aspects of communications between a master node and a secondary node in accordance with some embodiments described herein. 
         FIG.  3    describes a method performed by an apparatus of a node in accordance with some embodiments, 
         FIG.  4    describes aspects of communications between a master node and a secondary node in accordance with some embodiments described herein. 
         FIG.  5    describes a method performed by an apparatus of a node in accordance with some embodiments. 
         FIG.  6    illustrates an example UE, which may be configured for specialized operation or otherwise used with various embodiments described herein. 
         FIG.  7    is a block diagram illustrating an example computer system machine which may be used in association with various embodiments described herein, 
         FIG.  8    illustrates aspects of a UE, a wireless apparatus, or a device, in accordance with some example embodiments. 
         FIG.  9    illustrates example interfaces of baseband circuitry in accordance with some embodiments, 
         FIG.  10    is an illustration of a control-plane protocol stack in accordance with some embodiments. 
         FIG.  11    is an illustration of a user-plane protocol stack in accordance with some embodiments. 
         FIG.  12    is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. 
         FIG.  13    illustrates components of a core network in accordance with some embodiments. 
         FIG.  14    is a block diagram illustrating components, according to some example embodiments, of a system to support various embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims. 
       FIG.  1    illustrates an architecture of a system  100  of a network in accordance with some embodiments. The system  100  is shown to include a user equipment (UE)  101  and a UE  102 . The UEs  101  and  102  are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface. 
     In some embodiments, any of the UEs  101  and  102  can comprise an Internet of Things (IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network. 
     The UEs  101  and  102  may be configured to connect, e.g., communicatively couple, with a radio access network (RAN)  110 —the RAN  110  may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG-RAN), or some other type of RAN. The UEs  101  and  102  utilize connections  103  and  104 , respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections  103  and  104  are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (VII) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UNITS) protocol, a 3GPP Long-Term Evolution (LTE) protocol, a fifth generation (5G) protocol, a New Radio (NR) protocol, and the like. 
     In this embodiment, the UEs  101  and  102  may further directly exchange communication data via a ProSe interface  105 . The ProSe interface  105  may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH). 
     The UE  102  is shown to be configured to access an access point (AP)  106  via a connection  107 . The connection  107  can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, wherein the AP  106  would comprise a Wi-Fi® router. In this example, the AP  106  may be, for example, connected to the Internet without connecting to the core network of the wireless system (described in further detail below). 
     The RAN  110  can include one or more access nodes that enable the connections  103  and  104 . These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), next-generation NodeBs (gNB), RAN nodes, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). The RAN  110  may include one or more RAN nodes for providing macrocells, e.g., a macro RAN node ill, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), a low-power (LP) RAN node  112 . 
     Any of the RAN nodes  111  and  112  can terminate the air interface protocol and can be the first point of contact for the UEs  101  and  102 . In some embodiments, any of the RAN nodes  111  and  112  can fulfill various logical functions for the RAN  110  including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. 
     In accordance with some embodiments, the UEs  101  and  102  can be configured to communicate using Orthogonal Frequency-Division Multiplexing (OFDM) communication signals with each other or with any of the RAN nodes  111  and  112  over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an Orthogonal Frequency-Division Multiple Access (OFDMA) communication technique for downlink communications) or a Single-Carrier Frequency-Division Multiple Access (SC-TDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers. 
     In some embodiments, a downlink resource grid can be used for downlink transmissions from any of the RAN nodes  111  and  112  to the UEs  101  and  102 , while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted by a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks. 
     The physical downlink shared channel (PDSCH) may carry user data and higher-layer signaling to the UEs  101  and  102 . The physical downlink control channel (PDCCH) may carry information about the transport format and resource allocations related to the PDSCH, among other things. It may also inform the UEs  101  and  102  about the transport format, resource allocation, and Hybrid Automatic Repeat Request (H-ARQ) information related to the uplink shared channel. Typically, downlink scheduling (e.g., assigning control and shared channel resource blocks to the UE  102  within a cell) may be performed at any of the RAN nodes  111  and  112  based on channel quality information fed back from any of the UEs  101  and  102 . The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs  101  and  102 . 
     The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LIE with different numbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8). 
     Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced control channel elements (ECCEs). Like the CCEs described above, each ECCE may correspond to nine sets of tour physical resource elements known as enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations. 
     The RAN  110  is shown to be communicatively coupled to a core network (CN)  120  via an S1 interface  113 . In some embodiments, the CN  120  may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment, the S1 interface  113  is split into two parts: an S1 interface  114 , which carries traffic data between the RAN nodes  111  and  112  and a serving gateway (S-GW)  122 , and an S1-mobility management entity (MME) interface  115 , which is a signaling interface between the RAN nodes  111  and  112  and MMEs  121 . 
     In this embodiment, the CN  120  comprises the MMEs  121 , the S-GW  122 , a Packet Data. Network (PDN) Gateway (P-GW)  123 , and a home subscriber server (HSS)  124 . The MMEs  121  may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSNs). The MMEs  121  may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS  124  may comprise a database for network users, including subscription-related information to support the network entities&#39; handling of communication sessions. The CN  120  may comprise one or several HSSs  124 , depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS  124  can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc. 
     The S-GW  122  may terminate the S1 interface  113  towards the RAN  110 , and routes data packets between the RAN  110  and the CN  120 . In addition, the S-GW  122  may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement. 
     The P-GW  123  may terminate an SGi interface toward a PDN. The P-GW  123  may route data packets between the EPC network and external networks such as a network including an application server  130  (alternatively referred to as an application function (AF)) via an Internet Protocol (IP) communications interface  125 . Generally, the application server  130  may be an element offering applications that use IP bearer resources with the core network (e.g., UNITS Packet Services (PS) domain, LTE PS data services, etc.). In this embodiment, the P-GW  123  is shown to be communicatively coupled to the application server  130  via the IP communications interface  125 . The application server  130  can also be configured to support one or more communication services (e.g., Voice over Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs  101  and  102  via the CN  120 . 
     The P-GW  123  may further be a node for policy enforcement and charging data collection. A Policy and Charging Rules Function (PCRF)  126  is the policy and charging control element of the CN  120 , In a non-roaming scenario, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE&#39;s Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE&#39;s IP-CAN session: a Home PCRF (H-PCRF) within a HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF  126  may be communicatively coupled to the application server  130  via the P-GW  123 . The application server  130  may signal the PCRF  126  to indicate a new service flow and select the appropriate Quality of Service (QoS) and charging parameters. The PCRF  126  may provision this rule into a Policy and Charging Enforcement Function (PCEF) (not shown) with the appropriate traffic flow template (TFT) and QoS class identifier (QCI), which commences the QoS and charging as specified by the application server  130 . 
     In legacy LIE, network-based flow control via X2 has been defined for dual connectivity (DC). Similar mechanisms have also been defined for LTE wireless local area network (LTE-WLAN) aggregation (LWA) flow control via Xw. 
     In the context of New Radio (NR), network flow control is being discussed for three separate features: for Evolved Universal Mobile Telecommunications system Terrestrial Radio Access New Radio (E-UTRA-NR) Dual Connectivity (EN-DC) (e.g., via X2 interface), for fifth generation core network (5GC) (e.g., NGEN-DC) and Next-Generation Radio Area Network (NG-RAN) supported E-UTRA-NR DC (NE-DC) (e.g., via Xn interface), and for Central Unit (CU) and distributed unit (DU) split (e.g., via F1 interface). 
     In various systems, LTE DC flow control may be used as the baseline; however, embodiments disclosed herein include enhancements for network-based flow control for increased performance, better interoperability, and support for uplink and features unique to NR (e.g., secondary cell group (SCG) split-bearer operation, packet data convergence protocol (PDCP) duplication). 
     In embodiments of the present disclosure, we consider enhancements for the above use cases. The discussion of flow control may be broadly applied (e.g., using X2 as an example) with the understanding that enhancements are applicable to Xn, X2, and F1 interfaces. 
     Assuming LTE DC flow control in existing systems as the baseline, the following enhancements may be implemented (e.g., for X2, Xn, and F1 interfaces) in embodiments herein: 1) uplink support; 2) support for SCG split-bearer operation from the secondary node to the master node (e.g., for EN-DC, NGEN-DC, and NE-DC); 3) notification of highest successfully delivered PDCP protocol data unit (PDU) sequence number for PDCP duplication in the downlink; 4) notification of highest successfully received PDCP PDU sequence number for PDCP duplication in the uplink; and 5) different feedback triggering mechanisms (e.g., polling, configured periodicity, thresholds, etc.). 
       FIG.  2    illustrates aspects of various embodiments as described herein.  FIG.  2    includes a master node (MN)  210  and a secondary node (SN)  220 , which may communicate with each other in accordance with various embodiments described herein. In addition to the above-listed embodiments, other alternatives may operate with X2-based flow control without enhancements, which only control the downlink flow from the master node to the secondary node, Such communications are illustrated by a DL user data communication  222  from the MN  210  to the SN  220 , and a DL data delivery status communication  224  from the SN  220  to the MN  210  of  FIG.  2   . Such communications are part of the legacy mechanism. However, the legacy mechanism has certain deficiencies, such as that support for uplink and NR SCG split-bearer operation is not defined, and issues with enhancement for NR packet data convergence protocol (PDCP) duplication. 
     Stage-3 details for the enhancements of certain embodiments are thus described below. In some systems, there may be four frame formats for the X2 user-plane protocol, which may be applicable to the Xn and F1 interfaces as a baseline. These include DL USER DATA (PDU Type 0) and DL USER DATA EXTENDED (PDU Type 3), which may be defined to allow the secondary eNB (SeNB) to detect lost X2-U packets (e.g., packets lost on the X2 interface) and may be associated with the transfer of a downlink PDCP protocol data unit (PDU) over the X2-U interface. In various embodiments, the difference is the length of the PDCP sequence number (PDCP SN) to be supported. These also include DL DATA DELIVERY STATUS (PDU Type 1) and DL DATA DELIVERY STATUS EXTENDED (PDU Type 2), which may be defined to transfer feedback to allow the receiving master node (e.g., master eNB or MeNB) to control the downlink user data flow via the secondary node (e.g., secondary eNB or SeNB). Just as above, in some embodiments the difference may be the length of the PDCP SN to be supported. 
     To support the enhancements described in the principles above, Table 1 illustrates embodiments which may be represented as modifications of the legacy frame formats. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Bits 
                 Number of 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 7 
                 6 
                 5 
                 4 
                 3 
                 2 
                 1 
                 0 
                 Octets 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 PDU Type (=0) 
                 HS1 
                 HS2 
                 Spare 
                 1 
               
            
           
           
               
               
            
               
                 X2-U Sequence Number 
                 2 
               
               
                 Highest successfully delivered PDCP SN 
                 2* 
               
               
                   
                 {HS = 1} 
               
               
                 Highest successfully received PDCP SN 
                 2* 
               
               
                   
                 {HS = 2} 
               
               
                 Spare extension 
                 0-4 
               
               
                   
               
            
           
         
       
     
     Table 1 illustrates modification of DL USER DATA or DL USER DATA EXTENDED formats for use in accordance with embodiments described herein. In some embodiments, the modification descriptions may be based upon DL USER DATA (PDU Type 0), but the same modifications can be applicable to other frame formats (e.g., PDU Type 3) as well. In other embodiments, rather than modifying the legacy frame formats, a new format with a different PDU type number can be defined to support the enhancements. 
     In addition to the above embodiments, further embodiments may involve additional enhancements to frame formats. For uplink support enhancements, improvements may be made as follows. In legacy implementations, the uplink is transferred by the secondary node for the concerned E-UTRAN Radio Access Bearer (E-RAB) to the master node together with a DL DATA DELIVERY STATUS frame within the same GPRS Tunneling Protocol for the user plane (GTP-U) PDU. For the support of flow control for uplink PDCP PDU transfer, embodiments may define UL USER DATA and UL DATA DELIVERY STATUS for the uplink direction with different PDU type numbers, so that the uplink flow control is supported for the uplink as downlink flow control is for the downlink. Such enhancements enable a UL user data communication  232  and a UL data delivery status communication  234 . For downlink in DC, the MN  210  is typically the node sending packets and receiving feedback from the SN  220 . As illustrated by the communications  232  and  234 , embodiments described herein enable uplink flow control where the roles of the MN  210  and the SN  220  may be reversed. 
     Embodiments described herein also enable support for secondary cell group (SCG) split-bearer operation from the SN  220  to the MN  210  (e.g., for EN-DC, NGEN-DC, and NE-DC). Since the SCG split-bearer operation may be introduced in NR, in embodiments described herein, the downlink PDCP PDUs may be able to be transferred from the SN  220  to the MN  210  through the DL USER DATA. Moreover, in embodiments, the DL DATA DELIVERY STATUS may be able to be sent by the MN  210  for flow control by the SN  220  on those PDCP PDUs transferred from the SN  220  to the MN  210 . Such embodiments are described by a DL user data communication  242  and a DL data delivery status  244  of  FIG.  2   . In still further embodiments, the flow control for the uplink direction of SCG split-bearer operation can also be considered similar to the above uplink support. This is illustrated by a UL user data communication  252  and a UL data delivery status  254 , which illustrate the uplink flow control of the SCG split-bearer operation. 
     In any such systems, some embodiments may include a notification of the highest successfully delivered PDCP PDU sequence number for PDCP duplication in the downlink. If some PDCP PDUs are transferred to the secondary node (e.g., intended to be delivered to the UE by the secondary node), then in some such embodiments, the master node does not transmit those PDCP PDUs and waits for them to be delivered to the user equipment (UE) by the secondary node. This may also be applied to SCG split-bearer operation in the downlink direction by reversing the roles of the master node and secondary node in the above description. In some such embodiments, this may occur unless there is a report of loss over the interface in order to avoid the duplicative transmissions to the UE from both the master node and the secondary node. 
     Some embodiments may operate with support for packet duplication within NR-PDCP. This includes the ability for the master node to retransmit PDCP PDUs which were transferred to the secondary node to the UE directly, and provides latency benefits (e.g., helps meet NR latency targets such as ultra-reliability low latency communications (URLLC), etc.). 
     For PDCP duplication issues, embodiments may include a mechanism whereby the master node provides the highest successfully delivered PDCP SN to the secondary node in DL USER DATA format, so that the secondary node can avoid transmitting the already delivered (by the master node) PDCP PDUs to the UE. This indication can be by setting the “HS1” field to 1 in Table 1 above so that the secondary node can know the highest successfully delivered SN that was delivered to the UE by the master node and remove the buffered downlink PDCP PDUs accordingly to avoid duplicative transmission. In some embodiments, this may also be applied to SCG split-bearer operation in the downlink direction by reversing the roles of the master node and secondary node in the above description. Additionally, in some embodiments this may also be applicable to the F1 Interface (e.g., between a central unit (CU) and a distribution unit (DU)) in the downlink direction so that the CU provides the highest successfully delivered PDCP PDU SN to the DU (if they have already been delivered to the UE by another DU) to avoid duplicative transmission over that DU. 
     Further still, embodiments may include a notification of the highest successfully received PDCP PDU sequence number for PDCP duplication in the uplink. When the uplink bearer split is configured, if PDCP duplication is allowed for the uplink, it may be possible that the UE can retransmit PDCP PDUs, which were transmitted to the secondary node, to the master node again to meet the strict NR latency targets (e.g., such as URLLC, etc.). 
     Therefore, some embodiments may include a mechanism whereby the master node provides the highest successfully received PDCP SN to the secondary node, so that the secondary node can avoid transferring PDCP PDUs that were already successfully delivered to the receiving PDCP entity in the master node over the interface. Once the secondary node receives such a PDCP SN from the master node, the secondary node discards those already delivered. PDCP PDUs among PDCP PDUs successfully received from the UE on the secondary node side. In some such embodiments, there may be various options for how to notify the secondary node of such a highest successfully received PDCP SN. In one option, the DL USER DATA frame of the concerned E-RAB may be used. The indication can be by setting the “HS2” field to 1 (e.g., in Table 1 above) so that the secondary node can know the highest successfully received SN that was successfully delivered to the master node by the UE for the uplink direction and remove the buffered received PDCP PDUs to be carried over the interface to the master node. In a second option, the UL DATA DELIVERY STATUS frame may be used. A similar field structure to that of the first option can be considered for this UL DATA DELIVERY STATUS from the master node to the secondary node. In some embodiments, this can also be applied to SCG split-bearer operation in the uplink direction by reversing the roles of the master node and secondary node in the above description. Like other embodiments, this can be also applied to the F1 interface (between CU and DU) in the uplink direction so that the CU provides the highest successfully received PDCP PDU SN to the DU (if already received from the UE by another DU) to avoid duplicative transfer from that DU. 
       FIG.  3    illustrates an example method  300  performed by an apparatus of a node (e.g., a next-generation node B (gNB), evolved node B (eNB), or any such apparatus of a communication node) in accordance with the embodiments described herein (e.g., MN  210  or  410  or SN  220  or  420 ). In some embodiments, the method  300  of  FIG.  3    may be implemented by one or more processors of a device or an apparatus of any machine used to implement a node that includes processing circuitry. In other embodiments, the method  300  may be implemented as computer-readable instructions in a storage medium that, when executed by one or more processors of a device, cause the device to perform the method  300 . In some embodiments, the associated devices may be part of an NG-Radio Access Network (NG-RAN) node, with the associated device or apparatus within the NG-RAN comprising components such as processing circuitry, memory, interfaces, transmission circuitry, or other such circuit elements. 
     Method  300  includes operation  305  to access DL user data. The user data from operation  305  is then used in operation  310  to generate a DL user data message with the DL user data, and in operation  315 , the processing circuitry initiates transmission of the DL user data message to a second node. The second node receives and processes the DL user data message, and performs corresponding operations to generate a DL data delivery status message, After the DL data delivery status message is received, the processing circuitry processes the DL data delivery status message from the second node that was generated and sent by the second node in response to the DL user data message in operation  320 . 
     In various embodiments, the NR node comprises the SN and wherein the second node comprises the MN. This enables an SN to nange messaging and data delivery in a manner known in previous 3GPP systems for MN and SN operations. In some such embodiments, the DL user data comprises a highest successfully delivered PDCP protocol data unit (PDU) sequence number. In still further embodiments, the DL user data message comprises a DL, discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     Some embodiments operate where the DL, user data message comprises a first PDU type and the DL data delivery status message comprises a second PDU type. In some such embodiments, the DL data delivery status message comprises a parameter indicating a highest transmitted NR PDCP sequence number. In still further such embodiments, the DL data delivery status message comprises a parameter indicating a transmitted status associated with the highest transmitted NR PDCP sequence number. Still further embodiments may operate where the DL data delivery status message comprises a parameter indicating a highest retransmitted NR PDCP sequence number, or where the DL data delivery status message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number 
     Additionally, alternative embodiments may include similar operations for UL data, with the NR node as either the MN or the SN, and the second node operating as an MN when the NR node is the SN and the second node operating as an SN when the NR node is the MN. 
     In addition to the embodiments described above, for dual-connectivity operations and various communication systems described herein, additional embodiments may operate with new per-bearer metric feedback rather than per-bearer and per-UE buffer sizes (e.g., (average) throughput, (average) queuing delay, etc.), Additional embodiments may also further operate with optimization on the number of lost sequence number ranges reported. Other embodiments may operate with UE-based flow control; however, such systems (e.g., PDCP polling) have issues with standardized operation, and may have efficiency issues due to involvement of the air interface. Still another option is to keep legacy X2-based flow control without enhancements; however, the currently defined mechanism has certain deficiencies, including that report triggering is not defined (e.g., is left for the secondary eNB implementation), which may limit the efficiency of the scheduler in the master eNB. Also, some metrics are defined with per-UE granularity, rather than per-bearer granularity, which may have a negative impact on quality of service (QoS). Also, generally, existing current metrics are rather coarse e.g., limited to buffer status). The master node can, in theory, deduce other metrics (e.g., throughput) based on buffer status changes, but such estimation is slow and not precise. 
     Embodiments herein thus may use stage-3 user-plane details to provide enhancements. As described above, some systems operate with four frame formats for the X2 user-plane protocol, which will be applicable to the Xn and F1 interfaces as a baseline. These include DL USER DATA (PDU Type 0) and DL USER DATA EXTENDED (PDU Type 3), which are defined to allow the SeNB to detect lost X2-U packets (e.g., packets lost on the X2 interface) and are associated with the transfer of a downlink PDCP PDU over the X2-11 interface. These also include DL DATA DELIVERY STATUS (PDU Type 1) and DL DATA DELIVERY STATUS EXTENDED (PDU Type 2), which are defined to transfer feedback to allow the receiving MeNB to control the downlink user data flow via the SeNB. To support the enhancements described in the principles above, embodiments may modify the legacy frame formats. Tables 2 and 3 below illustrate an example in accordance with some embodiments. Table 2 illustrates an example modification of a DL USER DATA format, and Table 3 illustrates an example modification of a DL DATA DELIVERY STATUS format. 
     
       
         
           
               
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Bits 
                 Number of 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 7 
                 6 
                 5 
                 4 
                 3 
                 2 
                 1 
                 0 
                 Octets 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 PDU Type (=0) 
                 PL 
                 NM 
                 TV 
                 TH 
                 1 
               
            
           
           
               
               
            
               
                 X2-U Sequence Number 
                 2 
               
               
                 Periodic Reporting Timer Value (in ms) 
                 Y1* 
               
               
                   
                 {TV = 1} 
               
               
                 Number of successfully delivered PDCP PDUs to UE 
                 Y2* 
               
               
                   
                 {TH = 1} 
               
               
                 Spare extension 
                 0-4 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Bits 
                 Number of 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 7 
                 6 
                 5 
                 4 
                 3 
                 2 
                 1 
                 0 
                 Octets 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 PDU Type (=1) 
                 PLR 
                 NM 
                 Final 
                 Lost 
                 1 
               
               
                   
                   
                   
                 Frame 
                 Packet 
               
               
                   
                   
                   
                 Ind. 
                 Report 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 OF1 
                 AV1 
                 HS2 
                 OF2 
                 AV2 
                 AV3 
                 BSR 
                 Spare 
                 1 *{NM = 1} 
               
            
           
           
               
               
            
               
                 The X2-U Sequence Number which triggers the feedback by 
                 2* 
               
               
                 polling 
                 {PLR = 1} 
               
               
                 The time that this report is compiled/transmitted 
                 Z1* 
               
               
                   
                 {PLR = 4} 
               
               
                 Highest successfully delivered PDCP Sequence Number 
                 2 
               
               
                 Time offset (in ms) on highest successfully delivered PDCP 
                 Z2 
               
               
                 Sequence Number 
                 *{OF1 = 1} 
               
               
                 (Average) Throughput for the E-RAB (in-between reports) 
                 Z3 
               
               
                   
                 *{AV1 = 1} 
               
               
                 Desired buffer size for the E-RAB 
                 4 
               
               
                 Minimum desired buffer size for the UE 
                 4 
               
               
                 Highest PDCP Sequence Number processed by RLC 
                 2* 
               
               
                   
                 {HS2 = 1} 
               
               
                 Time offset (in ms) on highest PDCP Sequence Number 
                 Z4 
               
               
                 processed by RLC 
                 *{OF2 = 1} 
               
               
                 (Average) Queuing Delay until first transmitted (in-between 
                 Z5 
               
               
                 reports) 
                 *{AV2 = 1} 
               
               
                 (Average) RLC Delay per PDCP PDU until successfully 
                 Z6 
               
               
                 confirmed to be delivered from the first transmitted (in- 
                 *{AV3 = 1} 
               
               
                 between reports) 
               
               
                 Buffer Status Report from the UE 
                 Z7 
               
               
                   
                 *{BSR = 1} 
               
               
                 Number of lost X2-U Sequence Number ranges reported (Type 1) 
                 1 
               
               
                 Start of lost X2-U Sequence Number range 
                 4 
               
               
                 End of lost X2-U Sequence Number range 
                 *{Number 
               
               
                   
                 of reported 
               
               
                   
                 lost X2-U 
               
               
                   
                 SN ranges 
               
               
                   
                 (Type 1)} 
               
               
                 Number of lost X2-U Sequence Number ranges reported 
                 1 
               
               
                 (Type 2) 
               
               
                 Start of lost X2-U Sequence Number range 
                 3 
               
               
                 Consecutive number of lost X2-U packets from the Start of 
                 *{Number 
               
               
                 lost X2-U Sequence Number range above 
                 of reported 
               
               
                   
                 tost X2-U 
               
               
                   
                 SN ranges 
               
               
                   
                 (Type 2)} 
               
               
                 Spare extension 
                 0-4 
               
               
                   
               
            
           
         
       
     
     In such embodiments, the modifications are based upon DL USER DATA (PDU Type 0) and DL DATA DELIVERY STATUS (PDU Type 1), but the same modifications can be applicable to other frame formats (e.g., PDU Types 2 and 3) as well. In some embodiments, rather than modifying the existing frame formats, a new format with a different PDU type number can be defined to support the enhancements. 
     In some embodiments, the configuration information for the flow control enhancements can be delivered via a control-plane procedure from the master node to the secondary node. The configuration information can be delivered as part of the legacy procedure and message (e.g., in terms of X2-AP messages such as SENB ADDITION REQUEST, SENB MODIFICATION REQUEST, SENB RELEASE REQUEST, etc.) as a field. Alternatively, embodiments may include either new Class 1 or new Class 2 procedures with new message structures dedicated to flow control configuration setup, update, and release in the secondary node, as illustrated below in  FIG.  5    and Table 4. 
       FIG.  4    shows a master node (MN)  410  and a secondary node (SN)  420 . These two nodes include new communications for an X2-AP procedure for flow control configuration in the SN  420 . In the illustrated embodiment, this includes a flow control configuration update communication  422 , and a flow control configuration update acknowledge communication  424 . Table 4 illustrates aspects of an associated flow control configuration update message, including details of information elements (TEs) and associated details of the data in the message. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                   
                   
                   
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 Criticality 
                 Criticality 
               
               
                   
               
             
            
               
                 Message Type 
                 M 
                   
                 YES 
                 reject 
               
               
                 MeNB UE X2AP ID 
                 M 
                   
                 YES 
                 reject 
               
               
                 SeNB UE X2AP ID 
                 M 
                   
                 YES 
                 reject 
               
               
                 UE Context Information 
                   
                 0 . . . 1 
                 YES 
                 reject 
               
               
                 &gt;FLOW CONTROL 
                   
                 0 . . . 1 
                 — 
                 — 
               
               
                 CONFIGURATION 
               
               
                 To Be Added List 
               
               
                 &gt;&gt; FLOW CONTROL 
                   
                 1 . . . &lt;maxnoofBearers&gt; 
                 EACH 
                 ignore 
               
               
                 CONFIGURATION 
               
               
                 Be Added Item 
               
               
                 &gt;&gt;&gt;CHOICE Configuration 
                 M 
               
               
                 Type 
               
               
                 &gt;&gt;&gt;&gt;Configured Periodicity 
               
               
                 &gt;&gt;&gt;&gt;&gt;E-RAB ID 
                 M 
                   
                 — 
                 — 
               
               
                 &gt;&gt;&gt;&gt;&gt; Periodic Reporting 
                 M 
                   
                 — 
                 — 
               
               
                 Timer Value (in ms) 
               
               
                 &gt;&gt;&gt;&gt;Threshold-based 
               
               
                 Feedback 
               
               
                 &gt;&gt;&gt;&gt;&gt;E-RAB ID 
                 M 
                   
                 — 
                 — 
               
               
                 &gt;&gt;&gt;&gt;&gt; Number of 
                 M 
                   
                 — 
                 — 
               
               
                 successfully delivered 
               
               
                 PDCP PDUs to UE 
               
               
                 &gt;FLOW CONTROL 
                   
                 0 . . . 1 
                 — 
                 — 
               
               
                 CONFIGURATION 
               
               
                 To Be Modified List 
               
               
                 &gt;&gt; FLOW CONTROL 
                   
                 1 . . . &lt;maxnoofBearers&gt; 
                 EACH 
                 ignore 
               
               
                 CONFIGURATION 
               
               
                 Be Modified Item 
               
               
                 &gt;&gt;&gt;CHOICE Configuration 
                 M 
               
               
                 Type 
               
               
                 &gt;&gt;&gt;&gt;Configured Periodicity 
               
               
                 &gt;&gt;&gt;&gt;&gt;E-RAB ID 
                 M 
                   
                 — 
                 — 
               
               
                 &gt;&gt;&gt;&gt;&gt; Periodic Reporting 
                 M 
                   
                 — 
                 — 
               
               
                 Timer Value (in ms) 
               
               
                 &gt;&gt;&gt;&gt;Threshold-based 
               
               
                 Feedback 
               
               
                 &gt;&gt;&gt;&gt;&gt;E-RAB ID 
                 M 
                   
                 — 
                 — 
               
               
                 &gt;&gt;&gt;&gt;&gt; Number of 
                 M 
                   
                 — 
                 — 
               
               
                 successfully delivered 
               
               
                 PDCP PDUs to UE 
               
               
                 &gt; FLOW CONTROL 
                   
                 0 . . . 1 
                 — 
                 — 
               
               
                 CONFIGURATION 
               
               
                 To Be Released List 
               
               
                 &gt;&gt; FLOW CONTROL 
                   
                 1 . . . &lt;maxnoofBearers&gt; 
                 EACH 
                 ignore 
               
               
                 CONFIGURATION 
               
               
                 To Be Released Item 
               
               
                 &gt;&gt;&gt;CHOICE Configuration 
                 M 
               
               
                 Type 
               
               
                 &gt;&gt;&gt;&gt;Configured Periodicity 
               
               
                 &gt;&gt;&gt;&gt;&gt;E-RAB ID 
                 M 
                   
                 — 
                 — 
               
               
                 &gt;&gt;&gt;&gt;Threshold-based 
               
               
                 Feedback 
               
               
                 &gt;&gt;&gt;&gt;&gt;E-RAB ID 
                 M 
                   
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     In legacy mechanisms, it is up to the secondary node (e.g., SeNB) to decide on when to trigger the DL DATA DELIVERY STATUS feedback. This may result in inefficient flow control, as the master node (e.g., the MeNB which hosts PDCP for master cell group (MCG) and secondary cell group (SCG) split-bearer operation) cannot control when to trigger the feedback. In order for the master node to estimate round-trip time (RTT) over the interface, the feedback controlling mechanism should be in place, which will help manage the flow control over the interface. Moreover, control over triggering will allow for more optimal scheduling implementation in the master eNB. To give such control to the master node, embodiments may include one or more of the following mechanisms. 
     A first mechanism includes polling, Some embodiments of polling may use a one-bit indication to trigger the feedback from the secondary node. This polling bit can be embedded onto the DL USER DATA format (e.g., denoted by the “PL” field above). Once the secondary node receives DL USER DATA with the PL field set to 1, the secondary node immediately compiles the feedback (e.g., DL DATA DELIVERY STATUS message) and transmits it over the interface. When the secondary node compiles DL USER DATA STATUS, the associated field (e.g., the PLR field) is set (e.g., to a value of 1) in order to notify the master node that this feedback is generated due to the polling request. Additionally, in some embodiments the X2-U Sequence Number which triggers the feedback by polling field is set to the X2-U Sequence Number in the received DL USER DATA. This triggers the polling, in order to let the master node know which DL USER DATA this feedback corresponds to. This will enable the master node to calculate the round-trip time (RTT) of the interface assuming that this report is compiled and transmitted as soon as the secondary node receives the polling. Alternatively, in some embodiments, a time that this report is compiled/transmitted can be set to the time that this DL DELIVERY DATA STATUS is compiled/transmitted to let the master node know the report timing and estimate the one-way delay (e.g., from the secondary node to the master node) of the interface (e.g., and thus estimate the RTT by doubling it), from the time that the master node receives this report. The length of this time value can be up to several octets, dependent on how it is specified (e.g., currently denoted by “Z1”). In various embodiments, this is a fixed (not variable) value within the format. 
     Another mechanism is configured periodicity. Such embodiments operate to make the secondary node report the feedback (e.g., DL DATA DELIVERY STATUS message) periodically, which helps the master node to estimate variations of the estimated RTT over the interface. In some such embodiments, the one-bit indication of the “TV” field in the DL USER DATA format, when set to 1, as the secondary node override (or set if not configured before), along with setting the current periodic reporting timer value to the value in the “Periodic Reporting Timer Value (in ins)” field, causes the SN to start providing the feedback according to that configured periodicity. The length of this timer value can be up to several octets, dependent on how it is specified (currently denoted by “Y1”), and it is a fixed (not variable) value within the format. In other embodiments, the configuration information for the periodic reporting can be delivered by the existing or new X2-AP procedures. 
     Still another mechanism for managing flow control in accordance with some embodiments is a threshold mechanism. In such embodiments, some threshold-based reporting can be configured at the secondary node to report the feedback (e.g., a DL DATA DELIVERY STATUS message) whenever the configured threshold is met. One example can be the use of a “Number of successfully delivered PDCP PDUs to UE” field, such that whenever this number (e.g., threshold) of PDCP PDUs are successfully delivered to the UE, the report is triggered. As in the configured periodicity mechanism, the one-bit “TH” field in the DL USER DATA format, when set to 1, along with the secondary node override (or set if not configured before), operates with the current threshold-based reporting value set to the value in the “Number of successfully delivered PDCP PDUs to UE” field and operates to start providing the feedback whenever such a number of PDCP PDUs are successfully delivered to the UE. A length of the threshold value can be up to several octets, dependent on how it is specified (currently denoted by “Y2”). In some embodiments, this is a fixed (not variable) value within the format. Iii other embodiments, the configuration information for the threshold-based reporting can be delivered by the existing or a new X2-AP procedure. In some embodiments, it is not desirable to configure periodic reporting and threshold-based reporting simultaneously so as not to confuse the master node. 
     Still further embodiments may operate with new metric feedback rather than per-bearer and per-UE buffer sizes (e.g., average throughput, average queuing delay, etc.). In legacy mechanisms, per-UE and per-bearer buffer size are used for flow control, but buffer sizes alone are crude for minute flow control. To better assist the buffer management and for optimal scheduling in the master node, the following metrics may be considered in addition to the existing buffer size advertisements from the secondary node: (Average) Throughput per bearer; (Average) Queuing delay (per PDCP PDU or average) per bearer until first transmitted, i.e., the delay from the first receipt by the secondary node until it is first transmitted; (Average) Delay (per PDCP PDU or average) per bearer until successfully confirmed to be delivered from the time first transmitted by radio link control (RLC), i.e., the delay of the RLC retransmission; and a Buffer Status Report from the UE. In other embodiments, other metrics or other metrics in combination with the above metrics may be used. In some embodiments, the master node can request the above metrics by setting the “NM” field to 1 in DL USER DATA. Once the secondary node receives DL USER DATA with the “NM” field set to 1, from that time, it compiles the DL DATA DELIVERY STATUS with the “NM” field set to 1, and provides the available new metrics with the relevant field set to 1 in DL DATA DELIVERY STATUS. The secondary node provides the feedback of new additional metrics until it receives DL USER DATA with the “NM” field set to 0. 
     In some embodiments, there are different options for how the (average) throughput per bearer can be provided to the master node. One embodiment operates by re-using the existing “Highest successfully delivered PDCP Sequence Number” in DL DATA DELIVERY STATUS, This feedback operates to let the master node calculate the average throughput of this E-RAB. Some such embodiments may operate as follows. If the master node knows the RTT of the interface, and if the master node knows the time that this reported PDCP SN was transmitted to the secondary node, then the master node can calculate how long this PDCP SN took from the time it was received by the secondary node until it was successfully confirmed to be delivered by the UE. From this calculated time and the PDCP PM size, the master node can estimate the throughput of this E-RAB. Moreover, in some embodiments the master node can calculate more accurate throughput if it uses the consecutive “Highest successfully delivered PDCP Sequence Number” reported from the secondary node. However, this estimate may not be exact since there may be a gap between the time that this PDCP SN was successfully confirmed to be delivered and the time that this PDCP SN was reported in DL DATA DELIVERY STATUS. Therefore, embodiments may include a new metric, such as a “Time offset ms) on Highest successfully delivered PDCP Sequence Number” to let the master node know the time offset after which this PDCP SN was successfully confirmed to be delivered from the time that it was reported in DL DATA DELIVERY STATUS. The existence of this additional metric can be indicated, for example, when the OF1 field is set to 1. The length of this time offset value can be up to several octets, dependent on how it is specified (e.g., “Z3”). Such a value may be set to a fixed value within the format. 
     Another option for reporting throughput per bearer involves reporting the calculated average throughput directly by the secondary node. In some such embodiments, the secondary node can calculate and directly report the value of the average throughput per E-RAB. The average throughput may be calculated over the time between the consecutive feedback reports. 
     The existence of this additional metric can be indicated when the “AV” field is set to 1. The length of this time offset value can be up to several octets, dependent on how it is specified. 
     In some embodiments, the queuing delay (e.g., per PDCP PDU or average) until a PDCP PDU is first transmitted may also be reported. The additional metric of the queuing delay, reflecting how long the PDCP PDU is stored in the buffer of the secondary node until it is first transmitted over the air interface, can be provided to the master node to better manage the buffer of the secondary node and control the flow over the interface. To support the high data rate of the NR, there may be layer-2 protocol stacks to reduce the radio link control (RLC) and media access control (MAC) processing time to near zero ins when a transmission opportunity is available. Therefore, in such embodiments it is safe to neglect the RLC/MAC processing time, and the queuing delay can be defined from the time that the secondary node receives the PDCP PDU until the time that this PDCP PDU is processed by RLC/MAC and transmitted over the air interface. There are various options for how the (average) queuing delay per bearer can be provided to the master node. 
     One option involves using the highest PDCP sequence number processed by RLC. As in the first option described above for (average) throughput per bearer, for the queuing delay, the secondary node can report the highest PDCP sequence number processed by RLC. This PDCP SN can be reported with the “HS2” field set to 1 in DL DATA DELIVERY STATUS. The length of this field may be the same as the configured PDCP SN size. Moreover, as in the above-described first option for (average) throughput per bearer, the additional metric of “Time offset (in ms) on Highest PDCP Sequence Number processed by RLC” to indicate to the master node the time offset after which this PDCP SN was processed by RLC from the time that it was reported in DL DATA DELIVERY STATUS may be used. In some embodiments, the existence of this additional metric can be indicated when the “OF2” field is set to 1. The length of this time offset value can be up to several octets, dependent on how it is specified (e.g., denoted by “Z4”). 
     Another option for queuing delay involves reporting the calculated queuing time or average queuing delay directly by the secondary node. In some embodiments, the secondary node can calculate the time that the PDCP PDU associated with the reported “Highest successfully delivered PDCP SN” is delayed from the time it is received until it is successfully confirmed to be delivered to the UE. Alternatively, the secondary node can calculate and directly report the value of the average queuing delay per E-RAB. The average queuing delay may be better calculated over the time between the consecutive reports. The existence of this additional metric “(Average) Queuing Delay until first transmitted (in-between reports)” can be indicated when the “AV2” field is set to 1 in some embodiments. The length of this delay value can be up to several octets, dependent on how it is specified (currently denoted by “Z5”). 
     Delay (per PDCP PDU or average) of RLC re-transmission until PDCP PDUs are successfully confirmed to be delivered is another potential metric. In some embodiments, the additional metric of the RLC transmission/retransmission time from the time PDCP PDUs are first transmitted until they are successfully confirmed to be delivered can be provided to the master node to better manage the buffer of the secondary node and control the flow over the interface. This metric (either per PDCP PDU or average) can be calculated when the master node knows the above two metrics (throughput and queuing delay until first transmitted). However, the secondary node can calculate the time that the PDCP PDU associated with the reported “Highest successfully delivered PDCP SN” is delayed by the RLC transmission/retransmission until it is successfully confirmed to be delivered by the UE. In other embodiments, the secondary node can calculate its own value and directly report the average delay of the RLC transmission/retransmission until PDCP PDUs are successfully confirmed to be delivered. This metric may be calculated over a time between the consecutive reports. The existence of this additional metric “(Average) RLC Delay per PDCP PDU until successfully confirmed to be delivered from the first transmitted (in-between reports)” can be indicated when the “AV3” field is set to 1. The length of this delay value can be up to several octets, dependent on how it is specified (e.g., “Z6”). 
     Further still, some embodiments may operate with a Buffer Status Report (BSR) from the UE, The BSR. MAC control element (BSR MAC CE) reported by the UE to the secondary node can be provided to the master node for optimal scheduling, buffer management, and flow control. In some embodiments, the existence of this metric “Buffer Status Report from the UE” can be indicated when the “BSR” field is set to 1. (e.g., see table(s) above). In some embodiments a length of the BSR MAC CE can be up to 3 octets in accordance with MAC protocol specifications, but in NR it may be dependent on how it is specified (e.g., “Z7”). 
     Finally, some embodiments may operate with optimization on a number of lost sequence number ranges reported. Legacy systems operate with DL DATA DELIVERY STATUS reporting the lost X2-U packets by the ranges of the consecutive X2-U packets lost (e.g., start and end of each range). Reporting the start and end of each range takes twice the number of octets of the X2-U sequence number. This range report may be efficient when a large number of consecutive X2-U packets are lost. However, this may be inefficient when a small number of consecutive X2-U packets are lost. Even if there are only small gaps of missing X2-U packets, each loss report will take up twice the number of octets of the X2-U sequence number to denote the start and end of each range. For example, suppose that there is only one missing X2-U packet, with a sequence number of 1. Then, the report will be “start=1” and “end=1”, each taking up the size of the X2-U sequence number. In embodiments described herein, the reporting may be optimized by reporting a number of consecutive X2-U packets that were lost from the start, sequence number. If the system limits this number to 1 octet, then this can effectively reduce the octet size of the end sequence number to 1 octet (e.g., not 2 or 3 octets for the X2-U sequence number size) and can effectively report up to 256 consecutive lost X2-U packets from the start sequence number. Depending on the number of consecutive X2-U packets lost, in embodiments, the secondary node may compile the report as follows. If the consecutive number of missing packets is less than 256, then the secondary node may compile a report of Type 2 (e.g., see Table 3). If the number is more than 256, then it compiles the report as legacy (e.g., denoted by Type 1 in Table 3) by indicating a range from start to end sequence numbers. For each gap (smaller than 257) of consecutive X2-U packets lost when the secondary node is reporting, for each report, the system can save 1 octet compared to using the legacy mechanism. 
     In the embodiments described above, the master node (MN) is generally referred to as the node sending packets and receiving feedback from the secondary node (SN), which is true for downlink in DC. It is to be understood that the described enhancements may also be applicable to both uplink (UL) operations, in which case the roles of the MN and the SN are reversed, and to F1 operation. In F1 operation, the CU sends downlink packets and receives feedback from the DU, and the DU sends uplink packets and receives feedback from the CU. 
       FIG.  5    illustrates an example method  500  performed by an apparatus of a node (e.g., a next-generation node B (gNB), evolved node B (eNB), or any such apparatus of a communication node) in accordance with the embodiments described herein (e.g., MN  210  or  410  or SN  220  or  420 ). In some embodiments, the method  500  of  FIG.  5    may be implemented by one or more processors of a device or an apparatus of any machine used to implement a node that includes processing circuitry. In other embodiments, the method  500  may be implemented as computer-readable instructions in a storage medium that, when executed by one or more processors of a device, cause the device to perform the method  500 . In some embodiments, the associated devices may be part of an NG-Radio Access Network (NG-RAN) node, with the associated device or apparatus within the NG-RAN comprising components such as processing circuitry, memory, interfaces, transmission circuitry, or other such circuit elements. In some embodiments, the operations of method  500  are preceded by the operations of method  300 . In other embodiments, method  500  operate independently without the operations of method  300 . In still further embodiments, various combinations of any operations described herein may be used with either the operations of method  500  and/or the operations of method  300 . Some embodiments are implemented by an NR node where the NR node comprises a node hosting NR packet data convergence protocol (PDCP) operations, and a second node comprises a corresponding node. 
     Method  500  includes operation  305  to access flow control data. In operation  310 , the access flow control data is used to generate a flow control configuration update using the flow control data, and in operation  315 , transmission of the flow control configuration update to the second node is initiated. The flow control configuration is then received and processed at the an update acknowledgement message which is sent to the NR node. In operation  320  a DL data delivery status message is processed. In some embodiments, the flow control data comprises a report polling parameter. In still further embodiments, this report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     The methods describe particular embodiments, but it will be apparent that additional methods, in accordance with the embodiments described herein, are possible with repeated or intervening operations. For example, various embodiments of operations at a RAN, a gNB, a network device, and a UE are described above, and it will be apparent that corresponding operations at elements of a communication network other than those specifically described (e.g., operations at a gNB, UE, or core network device associated with described operations for another corresponding device) will occur in conjunction with the described operations. Further still, any embodiments described above may be performed with repeated operations or intervening operations in various different embodiments. Any of these operations may additionally involve generation or processing of communications, information elements, and/or fields described above in addition to the particular communications, information elements, and fields of the above methods. An additional set of non-exhaustive embodiments is further presented below. 
     EXAMPLE EMBODIMENTS 
     Example 1 may include a master node (MN) comprising: means for determining or causing to determine a signal to send to a secondary node (SN); means for transmitting or causing to transmit the determined signal; means for identifying or causing to identify a received signal from a secondary node (SN); and means for processing or causing to process the received signal. 
     Example 2 may include the subject matter of example 1, or of any other example herein, wherein means for determining or causing to determine a signal to send to an SN includes means for determining or causing to determine packets or flow control to send to the SN. 
     Example 3 may include the subject matter of example 2, or of any other example herein, wherein means for determining or causing to determine packets further includes means for determining or causing to determine packet data convergence protocol (PDCP) or protocol data unit (PM). 
     Example 4 may include the subject matter of example 1, or of any other example herein, wherein means for identifying or causing to identify a received signal from a SN further includes means for identifying or causing to identify feedback from the SN. 
     Example 5 may include the subject matter of example 1, or of any other example herein, wherein means for processing or causing to process the received signal further includes means for processing or causing to process flow control toward the MN. 
     Example 6 may include the subject matter of example 1, or of any other example herein, wherein the MN, SN, or another node or entity in communication with the MN or SN are interconnected by an interface. 
     Example 7 may include the subject matter of example 6, or of any other example herein, wherein the interface includes X2, Xn, or F1. 
     Example 8 may include the subject matter of example 7, or of any other example herein, wherein the user-plane entity for the interface supports DATA FRAME structure for transferring uplink packets toward a peer entity of the interface. 
     Example 9 may include the subject matter of example 8, or of any other example herein, wherein the user-plane entity for the interface is further to provide feedback of downlink or uplink packets received toward the peer entity of the interface for flow control by the peer entity. 
     Example 10 may include the subject matter of example 8, or of any other example herein, wherein the user-plane entity support for the DATA FRAME structure is further to include means for transferring or causing to transfer a highest successfully delivered PDCP sequence number for downlink or a highest successfully received PDCP sequence number for uplink for redundant transmission avoidance by the peer entity when PDCP duplication is configured. 
     Example 11 may include a secondary node (SN) comprising: means for determining or causing to determine a signal to send to a master node (MN); means for transmitting or causing to transmit the determined signal; means for identifying or causing to identify a received signal from a master node (MN); and means for processing or causing to process the received signal. 
     Example 12 may include the subject matter of example 11, or of any other example herein, wherein means for determining or causing to determine a signal to send to an MN includes means for determining or causing to determine packets or flow control to send to the MN. 
     Example 13 may include the subject matter of example 12, or of any other example herein, wherein means for determining or causing to determine packets further includes means for determining or causing to determine packet data convergence protocol (PDCP) or protocol data unit (PDU). 
     Example 14 may include the subject matter of example 11, or of any other example herein, wherein means for identifying or causing to identify a received signal from a MN further includes means for identifying or causing to identify feedback from the MN. 
     Example 15 may include the subject matter of example 11, or of any other example herein, wherein means for processing or causing to process the received signal further includes means for processing or causing to process flow control toward the SN. 
     Example 16 may include the subject matter of example 11, or of any other example herein, wherein the MN, SN, or another node or entity in communication with the SN or MN are interconnected by an interface. 
     Example 17 may include the subject matter of example 16, or of any other example herein, wherein the interface includes X2, Xn, or F1. 
     Example 18 may include the subject matter of example 17, or of any other example herein, wherein the user-plane entity for the interface support DATA FRAME structure for transferring downlink and uplink packets toward a peer entity of the interface. 
     Example 19 may include the subject matter of example 18, or of any other example herein, further including means for providing or causing to provide feedback of downlink and uplink packets received toward the peer entity of the interface for flow control by the peer entity. 
     Example 20 may include the subject matter of example 19, or of any other example herein, wherein the user-plane entity support for the DATA FRAME structure is further to include means for transferring or causing to transfer a highest successfully delivered PDCP sequence number for downlink or a highest successfully received. PDCP sequence number for uplink for redundant transmission avoidance by the peer entity when PDCP duplication is configured. 
     Example 21 may include radio access system network where the node or entities are interconnected by the interface (such as X2, Xn, or F1). The system at least includes a master node (MN) and a secondary node (SN), where the MN sends packets (e.g. PDCP PDU) and receiving feedback from the SN, and performs flow control toward the SN (or vice versa) 
     Example 22 may include the MN of example 21 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure for transferring uplink packets toward the peer entity of the said interface; and for providing feedback of downlink (e.g. in case of SCG split bearer) and uplink packets received toward the peer entity of the said interface for flow control by the peer entity. 
     Example 23 may include the SN of example 21 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure for transferring downlink (e.g. in case of SCG split bearer) and uplink packets toward the peer entity of the said interface; and for providing feedback of downlink and uplink packets received toward the peer entity of the said interface for flow control by the peer entity. 
     Example 24 may include the MN or SN of example 21 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure for transferring highest successfully delivered PDCP sequence number for downlink and highest successfully received PDCP sequence number for uplink toward the peer entity of the said interface for redundant transmission avoidance by the peer entity in case of PDCP duplication configured 
     Example 25 may be a master node (MN) to: determine or cause to determine a signal to send to a secondary node (SN); transmit or cause to transmit the determined signal; identify or cause to identify a received signal from a secondary node (SN); and process or cause to process the received signal. 
     Example 26 may include the subject matter of example 25, or of any other example herein, wherein determine or cause to determine a signal to send to an SN includes determine or cause to determine packets or flow control to send to the SN. 
     Example 27 may include the subject matter of example 26, or of any other example herein, wherein determine or cause to determine packets further includes determine or cause to determine packet data convergence protocol (PDCP) or protocol data unit (PDU). 
     Example 28 may include the subject matter of example 25, or of any other example herein, wherein identify or cause to identify a received signal from a SN further includes identify or cause to identify feedback from the SN. 
     Example 29 may include the subject matter of example 25, or of any other example herein, wherein process or cause to process the received signal further includes process or cause to process flow control toward the MN. 
     Example 30 may include the subject matter of example 25, or of any other example herein, wherein the MN, SN, or another node or entity in communication with the MN or SN are interconnected by an interface. 
     Example 31 may include the subject matter of example 30, or of any other example herein, wherein the interface includes X2, Xn, or FT. 
     Example 32 may include the subject matter of example 31, or of any other example herein, wherein the user-plane entity for the interface supports DATA FRAME structure for transferring uplink packets toward a peer entity of the interface. 
     Example 33 may include the subject matter of example 32, or of any other example herein, wherein the user-plane entity for the interface is further to provide feedback of downlink or uplink packets received toward the peer entity of the interface for flow control by the peer entity. 
     Example 34 may include the subject matter of example 32, or of any other example herein, wherein the user-plane entity support for the DATA FRAME structure is further to include transfer or cause to transfer a highest successfully delivered PDCP sequence number for downlink or a highest successfully received PDCP sequence number for uplink for redundant transmission avoidance by the peer entity when it PDCP duplication is configured. 
     Example 35 may include a secondary node (SN) to: determine or cause to determine a signal to send to a master node (MN); transmit or cause to transmit the determined signal; identify or cause to identify a received signal from a master node (MN); and process or cause to process the received signal. 
     Example 36 may include the subject matter of example 35, or of any other example herein, wherein determine or cause to determine a signal to send to an MN includes determining or causing to determine packets or flow control to send to the MN. 
     Example 37 may include the subject matter of example 36, or of any other example herein, wherein determine or cause to determine packets further includes determine or cause to determine packet data convergence protocol (PDCP) or protocol data unit (PDU). 
     Example 38 may include the subject matter of example 35, or of any other example herein, wherein identify or cause to identify a received signal from a MN further includes identify or cause to identify feedback from the MN. 
     Example 39 may include the subject matter of example 35, or of any other example herein, wherein process or cause to process the received signal further includes process or cause 
     Example 40 may include the subject matter of example 35, or of any other example herein, wherein the MN, SN, or another node or entity in communication with the SN or MN are interconnected by an interface. 
     Example 41 may include the subject matter of example 40, or of any other example herein, wherein the interface includes X2, Xn, or F1. 
     Example 42 may include the subject matter of example 41, or of any other example herein, wherein the user-plane entity for the interface support DATA FRAME structure for transferring downlink and uplink packets toward a peer entity of the interface. 
     Example 43 may include the subject matter of example 42, or of any other example herein, further including provider cause to provide feedback of downlink and uplink packets received toward the peer entity of the interface for flow control by the peer entity. 
     Example 44 may include the subject matter of example 43, or of any other example herein, wherein the user-plane entity support for the DATA FRAME structure is further to include transfer or cause to transfer a highest successfully delivered PDCP sequence number for downlink or a highest successfully received PDCP sequence number for uplink for redundant transmission avoidance by the peer entity when PDCP duplication is configured. 
     Example 45 may include a method for implementing a master node (MN) comprising: determining or causing to determine a signal to send to a secondary node (SN); transmitting or causing to transmit the determined signal; identifying or causing to identify a received signal from a secondary node (SN); and processing or causing to process the received signal. 
     Example 46 may include the subject matter of example 45, or of any other example herein, wherein determining or causing to determine a signal to send to an SN includes determining or causing to determine packets or flow control to send to the SN. 
     Example 47 may include the subject matter of example 46, or of any other example herein, wherein determining or causing to determine packets further includes determining or causing to determine packet data convergence protocol (PDCP) or protocol data unit (PDU). 
     Example 48 may include the subject matter of example 45, or of any other example herein, wherein identifying or causing to identify a received signal from a SN further includes identifying or causing to identify feedback from the SN. 
     Example 49 may include the subject matter of example 45, or of any other example herein, wherein processing or causing to process the received signal further includes processing or causing to process flow control toward the MN. 
     Example 50 may include the subject matter of example 45, or of any other example herein, wherein the MN, SN, or another node or entity in communication with the MN or SN are interconnected by an interface. 
     Example 51 may include the subject matter of example 50, or of any other example herein, wherein the interface includes X2, Xn, or F1. 
     Example 52 may include the subject matter of example 51, or of any other example herein, wherein the user-plane entity for the interface supports DATA FRAME structure for transferring uplink packets toward a peer entity of the interface. 
     Example 53 may include the subject matter of example 52, or of any other example herein, wherein the user-plane entity for the interface is further to provide feedback of downlink or uplink packets received toward the peer entity of the interface for flow control by the peer entity. 
     Example 54 may include the subject matter of example 52, or of any other example herein, wherein the user-plane entity support for the DATA FRAME structure is further to include transferring or causing to transfer a highest successfully delivered PDCP sequence number for downlink or a highest successfully received PDCP sequence number for uplink for redundant transmission avoidance by the peer entity when PDCP duplication is configured. 
     Example 55 may include a method for implementing a secondary node (SN) comprising: determining or causing to determine a signal to send to a master node (MN); transmitting or causing to transmit the determined signal; identifying or causing to identify a received signal from a master node (MN); and processing or causing to process the received signal. 
     Example 56 may include the subject matter of example 55, or of any other example herein, wherein determining or causing to determine a signal to send to an MN includes determining or causing to determine packets or flow control to send to the MN. 
     Example 57 may include the subject matter of example 56, or of any other example herein, wherein determining or causing to determine packets further includes determining or causing to determine packet data convergence protocol (PDCP) or protocol data unit (PDU). 
     Example 58 may include the subject matter of example 55, or of any other example herein, wherein identifying or causing to identify a received signal from a MN further includes identifying or causing to identify feedback from the MN. 
     Example 59 may include the subject matter of example 55, or of any other example herein, wherein processing or causing to process the received signal further includes processing or causing to process flow control toward the SN. 
     Example 60 may include the subject matter of example 55, or of any other example herein, wherein the MN, SN, or another node or entity in communication with the SN or MN are interconnected by an interface. 
     Example 61 may include the subject matter of example 60, or of any other example herein, wherein the interface includes X2, Xn, or F1. 
     Example 62 may include the subject matter of example 61, or of any other example herein, wherein the user-plane entity for the interface support DATA FRAME structure for transferring downlink and uplink packets toward a peer entity of the interface. 
     Example 63 may include the subject matter of example 62, or of any other example herein, further including providing or causing to provide feedback of downlink and uplink packets received toward the peer entity of the interface for flow control by the peer entity. 
     Example 64 may include the subject matter of example 63, or of any other example herein, wherein the user-plane entity support for the DATA FRAME structure is further to include transferring or causing to transfer a highest successfully delivered PDCP sequence number for downlink or a highest successfully received PDCP sequence number for uplink for redundant transmission avoidance by the peer entity when PDCP duplication is configured. 
     Example 65 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of examples 1-64, or any other method or process described herein. 
     Example 66 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-64, or any other method or process described herein. 
     Example 67 may include an apparatus comprising logic, modules, or circuitry to perform one or more elements of a method described in or related to any of examples 1-64, or any other method or process described herein. 
     Example 68 may include a method, technique, or process as described in or related to any of examples 1-64, or portions or parts thereof. 
     Example 69 may include an apparatus comprising: one or more processors and one or more computer readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-64, or portions thereof. 
     Example 70 may include a signal as described in or related to any of examples 1-64, or portions or parts thereof. 
     Example 71 may include the radio access system network where the node or entities are interconnected by the interface (such as X2, Xn, or F1). The system at least includes a master node (MN) and a secondary node (SN), where the MN sends packets (e.g. PDCP PDU) and receiving feedback from the SN, and performs flow control toward the SN (or vice versa) 
     Example 72 may include the MN or SN of example 71 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure to trigger feedback report from the peer entity by polling. 
     Example 73 may include the MN or SN of example 71 or some other example herein, wherein the control-plane entity for the said interface support procedure and message structure to configure/update/release periodic or even-based report triggering over the user-plane for the said interface. 
     Example 74 may include the MN or SN of example 71 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure to provide feedback report to the peer entity according to triggering configured by the control-plane entity or when polled by the peer entity over the user-plane. 
     Example 75 may include the MN or SN of example 71 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure to request specific feedback (such as throughput, queueing delay, RLC delay, Buffer Status Report, etc.) to the peer entity for the accurate metric estimation and flow control. 
     Example 76 may include the MN or SN of example 71 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure to provide the requested feedback in the report to the peer entity for the flow control by the peer entity. 
     Example 77 may include the MN or SN of example 71 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure to provide the time offset information for the reported PDCP SN (e.g. highest successfully delivered PDCP SN to the UE) until the time carried by the report for the accurate metric estimation by the peer entity. 
     Example 78 may include the MN or SN of example 71 or some other example herein, wherein the user-plane entity for the said interface support DATA FRAME structure to provide the report of the missing packets status by the number of consecutive lost packets from the start SN to the peer entity 
     Example 79 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of examples 71-78, or any other method or process described herein. 
     Example 80 may include one or more non-transitory computer-readable readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 71-78, or any other method or process described herein. 
     Example 81 may include an apparatus comprising logic, modules, or circuitry to perform one or more elements of a method described in or related to any of examples 71-78, or any other method or process described herein. 
     Example 82 may include a method, technique, or process as described in or related to any of examples 71-78, or portions or parts thereof. 
     Example 83 may include an apparatus comprising: one or more processors and one or more computer readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 71-78, or portions thereof. 
     Example 84 may include a signal as described in or related to any of examples 71-78, or portions or parts thereof. 
     Example 85 may include a signal in a wireless network as shown and described herein. 
     Example 86 may include a method of communicating in a wireless network as shown and described herein. 
     Example 87 may include a system for providing wireless communication as shown and described herein. 
     Example 88 may include a device for providing wireless communication as shown and described herein. 
     Example 89 is an apparatus of a New Radio (NR) node configured for NR user-plane protocol communications between a master node (MN) and a secondary node (SN), the apparatus comprising: processing circuitry configured to: access downlink (DL) user data; generate a DL user data message with the DL user data; initiate transmission of the DL user data message to a second node; and process a DL data delivery status message from the second node in response to the DL user data message; and an interface coupled to the processing circuitry configured to communicate the DL user data message to the second node and receive the DL data delivery status message from the second node. 
     In Example 90, the subject matter of Example 89 optionally includes wherein the NR node comprises the SN and wherein the second node comprises the MN. 
     In Example 91, the subject matter of Example 90 optionally includes wherein the DL user data comprises a highest successfully delivered PDCP protocol data unit (PDU) sequence number. 
     In Example 92, the subject matter of Example 91 optionally includes wherein the DL user data message comprises a DL discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     In Example 93, the subject matter of any one or more of Examples 89-92 optionally include wherein the NR node comprises a node hosting NR packet data convergence protocol (PDCP) operations, and the second node comprises a corresponding node. 
     In Example 94, the subject matter of Example 93 optionally includes wherein the processing circuitry is further configured to: access flow control data, generate a flow control configuration update using the flow control data; initiate transmission of the flow control configuration update to the second node; and process a flow control configuration update acknowledgement from the second node. 
     In Example 95, the subject matter of Example 94 optionally includes wherein the flow control data comprises a report polling parameter. 
     In Example 96, the subject matter of Example 95 optionally includes wherein the report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     In Example 97, the subject matter of any one or more of Examples 89-96 optionally include wherein the DL user data message comprises a first PDU type and the DL data delivery status message comprises a second PDU type. 
     In Example 98, the subject matter of Example 97 optionally includes wherein the DL data delivery status message comprises a parameter indicating a highest transmitted NR PDCP sequence number. 
     In Example 99, the subject matter of Example 98 optionally includes wherein the DL data delivery status message comprises a parameter indicating a transmitted status associated with the highest transmitted NR PDCP sequence number. 
     In Example 100, the subject matter of any one or more of Examples 97-99 optionally include wherein the DL data delivery status message comprises a parameter indicating a highest retransmitted NR PDCP sequence number. 
     In Example 101, the subject matter of Example 100 optionally includes wherein the DL data delivery status message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     Example 102 is a computer readable storage medium comprising instructions that, when executed by one or more processors of a New Radio (NR) node configured for NR user-plane protocol communications between a master node (MN) and a secondary node (SN), cause the one or more processors to: access downlink (DL) user data; generate a DL user data message with the DL user data; initiate transmission of the DL user data message to a second node; and process a DL data delivery status message from the second node in response to the DL user data message. 
     In Example 103, the subject matter of Example 102 optionally includes wherein the NR node comprises the SN and wherein the second node comprises the MN. 
     In Example 104, the subject matter of Example 103 optionally includes wherein the DL user data comprises a highest successfully delivered PDCP protocol data unit (PDU) sequence number. 
     In Example 105, the subject matter of Example 104 optionally includes wherein the DL user data message comprises a DL discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     In Example 106, the subject matter of any one or more of Examples 102-105 optionally include wherein the processing circuitry is further configured to: access flow control data; generate a flow control configuration update using the flow control data; initiate transmission of the flow control configuration update to the second node; and process a flow control configuration update acknowledgement from the second node. 
     In Example 107, the subject matter of Example 106 optionally includes wherein the flow control data comprises a report polling parameter, and wherein the report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     In Example 108, the subject matter of any one or more of Examples 102-107 optionally include wherein the DL user data message comprises a first PDU type and the DL data delivery status message comprises a second PDU type. 
     In Example 109, the subject matter of Example 108 optionally includes wherein the DL data delivery status message comprises a parameter indicating a highest transmitted NR PDCP sequence number; and wherein the DL data delivery status message comprises a parameter indicating a transmitted status associated with the highest transmitted NR PDCP sequence number. 
     In Example 110, the subject matter of any one or more of Examples 108-109 optionally include wherein the DL data delivery status message comprises a parameter indicating a highest retransmitted NR PDCP sequence number; and wherein the DL data delivery status message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     Example 111 is a method performed by one or more processors of a New Radio (NR) node configured for NR user-plane protocol communications between a master node (MN) and a secondary node (SN), the method comprising: accessing downlink (DL) user data; generating a DL user data message with the DL user data; initiating transmission of the DL user data message to a second node; and processing a DL data delivery status message from the second node in response to the DL user data message. 
     In Example 112, the subject matter of Example 111 optionally includes wherein the NR node comprises the SN and wherein the second node comprises the MN. 
     In Example 113, the subject matter of Example 112 optionally includes wherein the DL user data comprises a highest successfully delivered. PDCP protocol data unit (PDU) sequence number. 
     In Example 114, the subject matter of Example 113 optionally includes wherein the DL user data message comprises a DL discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     In Example 115, the subject matter of any one or more of Examples 111-114 optionally include wherein the NR node comprises a node hosting NR packet data convergence protocol (PDCP) operations, and the second node comprises a corresponding node. 
     In Example 116, the subject matter of Example 115 optionally includes further comprising: accessing flow control data; generating a flow control configuration update using the flow control data; initiating transmission of the flow control configuration update to the second node; and processing a flow control configuration update acknowledgement from the second node. 
     In Example 117, the subject matter of Example 116 optionally includes wherein the flow control data comprises a report polling parameter. 
     In Example 118, the subject matter of Example 117 optionally includes wherein the report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     In Example 119, the subject matter of any one or more of Examples 111-118 optionally include embodiments wherein the DL user data message comprises a first PDU type and the data delivery status message comprises a second PDU type. 
     In Example 120, the subject matter of Example 119 optionally includes wherein the DL data delivery status message comprises a parameter indicating a highest transmitted NR PDCP sequence number. 
     In Example 121, the subject matter of Example 120 optionally includes wherein the DL data delivery status message comprises a parameter indicating a transmitted status associated with the highest transmitted NR PDCP sequence number. 
     In Example 122, the subject matter of any one or more of Examples 119-121 optionally include wherein the DL data delivery status message comprises a parameter indicating a highest retransmitted NR PDCP sequence number. 
     In Example 123, the subject matter of Example 122 optionally includes wherein the DL data delivery status message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     Example 124 is an apparatus of a New Radio (NR) node configured as a secondary node (SN) for NR user-plane protocol communications with a master node (MN), the apparatus comprising: processing circuitry configured to: access downlink (UL) user data; generate an UL user data message with the UL user data; initiate transmission of the EL user data message to the MN; and process an EL data delivery status message from the MN in response to the UL user data message; and an interface coupled to the processing circuitry configured to communicate the UL user data message to the MN and receive the UL data delivery status message from the MN. 
     In Example 125, the subject matter of Example 124 optionally includes wherein the UL user data comprises a highest successfully delivered PDCP protocol data unit (PDU) sequence number. 
     In Example 126, the subject matter of Example 125 optionally includes wherein the UL user data message comprises a UL discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     Example 127 is an apparatus of a New Radio (NR) node configured as a master node (MN) for NR user-plane protocol communications with a secondary node (SN), the apparatus comprising: processing circuitry configured to; access downlink (UL) user data; generate an UL user data message with the UI, user data; initiate transmission of the UL user data message to the SN; and process an UL data delivery status message from the SN in response to the UL user data message; and an interface coupled to the processing circuitry configured to communicate the UI, user data message to the SN and receive the UL data delivery status message from the SN. 
     In Example 128, the subject matter of any one or more of Examples 124-127 optionally include wherein the UL user data comprises a highest successfully delivered PDCP protocol data unit (PDU) sequence number. 
     In Example 129, the subject matter of any one or more of Examples 125-128 optionally include wherein the UL user data message comprises a UL discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     In Example 130, the subject matter of any one or more of Examples 117-129 optionally include wherein the report polling parameter indicates that the NR node hosting the NR PDCP operations requests a downlink delivery status report. 
     In Example 131, the subject matter of any one or more of Examples 115-130 optionally include further comprising: means for accessing flow control data; means for generating a flow control configuration update using the flow control data; means for initiating transmission of the flow control configuration update to the second node; and means for processing a flow control configuration update acknowledgement from the second node. 
     In Example 132, the subject matter of any one or more of Examples 120-131 optionally include wherein the DL data delivery status message comprises a parameter indicating a transmitted status associated with the highest transmitted NR PDCP sequence number. 
     In Example 133, the subject matter of any one or more of Examples 111-132 optionally include wherein the DL user data message comprises a first PDU type and the DL data delivery status message comprises a second PDU type. 
     In Example 134, the subject matter of any one or more of Examples 113-133 optionally include wherein the DL user data message comprises a DL discard field based on the highest successfully delivered PDCP PDU sequence number indicating a sequence number up to and including which all NR PDCP PDUs should be discarded by the second node. 
     In Example 135, the subject matter of any one or more of Examples 111-134 optionally include wherein the NR node comprises the SN and wherein the second node comprises the MN. 
     In Example 136, the subject matter of any one or more of Examples 111-135 optionally include wherein the NR node comprises a node hosting NR packet data convergence protocol (PDCP) operations, and the second node comprises a corresponding node. 
     In Example 137, the subject matter of any one or more of Examples 135-136 optionally include wherein the DL user data comprises a highest successfully delivered PDCP protocol data unit (PDU) sequence number. 
     In Example 138, the subject matter of any one or more of Examples 122-137 optionally include wherein the DL data delivery status message comprises a parameter indicating a status associated with the highest retransmitted NR PDCP sequence number. 
     In Example 139, the subject matter of any one or more of Examples 133-138 optionally include wherein the DL data delivery status message comprises a parameter indicating a highest retransmitted NR PDCP sequence number. 
     Example 140 is an apparatus of a New Radio (NR) node configured for NR user-plane protocol communications between a master node (MN) and a secondary node (SN), the apparatus comprising: means for accessing downlink (DL) user data; means for generating a DL user data message with the DL user data; means for initiating transmission of the DL user data message to a second node; and means for processing a DL data delivery status message from the second node in response to the DL user data message. 
     In Example 141, the subject matter of any one or more of Examples 131-140 optionally include wherein the flow control data comprises a report polling parameter. 
     In Example 142, the subject matter of any one or more of Examples 133-141 optionally include wherein the DL data delivery status message comprises a parameter indicating a highest transmitted NR PDCP sequence number. 
     The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. 
     In addition to the above example embodiments, any combination of operations or elements described above may be integrated into various embodiments described herein. Additionally, other example embodiments may include any examples described above with the individual operations or device elements repeated or ordered with intervening elements or operations in any functional order. 
       FIG.  6    shows an example UE  600 , The UE  600  may be an implementation of the UEs  101 ,  102 , or any other device described herein. The UE  600  can include one or more antennas  608  configured to communicate with a transmission station, such as a base station, an eNB/gNB, or another type of wireless wide area network (WWAN) access point. The UE  600  can communicate using separate antennas for each wireless communication standard or shared antennas for multiple wireless communication standards. The UE  600  can communicate in a wireless local area network (WLAN), a wireless personal area network (WPAN), and/or a WWAN. 
       FIG.  6    also shows a microphone  620  and one or more speakers  612  that can be used for audio input and output to and from the UE  600 . As a headed device, the UE  600  includes one or more interfaces for a UI. The UE  600  particularly includes a display screen  604 , which can be a liquid crystal display (LCD) screen or another type of display screen such as an organic light-emitting diode (OLED) display. The display screen  604  can be configured as a touch screen. The touch screen can use capacitive, resistive, or another type of touchscreen technology. An application processor  614  and a graphics processor  618  can be coupled to an internal memory  616  to provide processing and display capabilities. A non-volatile memory port  610  can also be used to provide data input/output (I/O) options to a user. The non-volatile memory port  610  can also be used to expand the memory capabilities of the UE  600 . A keyboard  606  can be integrated with the UE  600  or wirelessly connected to the UE  600  to provide additional user input. A virtual keyboard can also be provided using the touch screen. A camera  622  located on the front (display screen  604 ) side or the rear side of the UE  600  can also be integrated into a housing  602  of the UE  600 . 
       FIG.  7    is a block diagram illustrating an example computer system machine  700  upon which any one or more of the methodologies herein discussed can be performed, and which may be used to implement the UEs  101 ,  102 , or any other device described herein. In various alternative embodiments, the computer system machine  700  operates as a standalone device or can be connected (e.g., networked) to other machines. In a networked deployment, the computer system machine  700  can operate in the capacity of either a server or a client machine in server-client network environments, or it can act as a peer machine in peer-to-peer (or distributed) network environments. The computer system machine  700  can be a personal computer (PC) that may or may not be portable (e.g., a notebook or a netbook), a tablet, a set-top box (STB), a gaming console, a Personal Digital Assistant (PDA), a mobile telephone or smartphone, a web appliance, a network router, a network switch, a network bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single computer system machine  700  is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. 
     The example computer system machine  700  includes a processor  702  (e.g., a central processing unit (CPU), a graphics processing unit (GPU), or both), a main memory  704 , and a static memory  706 , which communicate with each other via an interconnect  708  (e.g., a link, a bus, etc.). The computer system machine  700  can further include a video display device  710 , an alphanumeric input device  712  (e.g., a keyboard), and a user interface (UI) navigation device  714  (e.g., a mouse). In one embodiment, the video display device  710 , alphanumeric input device  712 , and UI navigation device  714  are a touch-screen display. The computer system machine  700  can additionally include a mass storage device  716  (e.g., a drive unit), a signal generation device  718  (e.g., a speaker), an output controller  732 , a power management controller  734 , a network interface device  720  (which can include or operably communicate with one or more antennas  730 , transceivers, or other wireless communications hardware), and one or more sensors  728 , such as a Global Positioning System (GPS) sensor, compass, location sensor, accelerometer, or other sensor. 
     The mass storage device  716  includes a machine-readable medium  722  on which is stored one or more sets of data structures and instructions  724  (e.g., software) embodying or utilized by any one or more of the methodologies or functions described herein. The instructions  724  can also reside, completely or at least partially, within the main memory  704 , the static memory  706 , and/or the processor  702  during execution thereof by the computer system machine  700 , with the main memory  704 , the static memory  706 , and the processor  702  also constituting machine-readable media. 
     While the machine-readable medium  722  is illustrated in an example embodiment to be a single medium, the term “machine-readable medium” can include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more instructions  724 . The term “machine-readable medium” shall also be taken to include any tangible medium that is capable of storing, encoding, or carrying instructions (e.g., the instructions  724 ) for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present disclosure, or that is capable of storing, encoding, or carrying data structures utilized by or associated with such instructions. 
     The instructions  724  can further be transmitted or received over a communications network  726  using a transmission medium via the network interface device  720  utilizing any one of a number of well-known transfer protocols (e.g., hypertext transfer protocol (HTTP)). The term “transmission medium” shall be taken to include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible media to facilitate communication of such software. 
     Various techniques, or certain aspects or portions thereof, may take the form of program code (e.g., the instructions  724 ) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, non-transitory computer-readable storage media, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the various techniques. In the case of program code execution on programmable computers, the computer may include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. The volatile and non-volatile memory and/or storage elements may be a Random Access Memory (RAM), Erasable Programmable Read-Only Memory (EPROM), flash drive, optical drive, magnetic hard drive, or other medium for storing electronic data. The base station and UE may also include a transceiver module, a counter module, a processing module, and/or a clock module or timer module. One or more programs that may implement or utilize the various techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, the program(s) may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations. 
       FIG.  8    illustrates example components of a device  800  in accordance with some embodiments. In some embodiments, the device  800  may include application circuitry  802 , baseband circuitry  804 , Radio Frequency (RF) circuitry  806 , front-end module (FEM) circuitry  808 , one or more antennas  810 , and power management circuitry (PMC)  812  coupled together at least as shown. The components of the illustrated device  800  may be included in a UE or a RAN node. In some embodiments, the device  800  may include fewer elements (e.g., a RAN node may not utilize the application circuitry  802 , and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device  800  may include additional elements such as, for example, memory/storage, a display, a camera, a sensor, or an input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations). 
     The application circuitry  802  may include one or more application processors. For example, the application circuitry  802  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the device  800 . In some embodiments, processors of the application circuitry  802  may process IP data packets received from an EPC. 
     The baseband circuitry  804  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry  804  may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry  806  and to generate baseband signals for a transmit signal path of the RF circuitry  806 . The baseband circuitry  804  may interface with the application circuitry  802  for generation and processing of the baseband signals and for controlling operations of the RE circuitry  806 . For example, in some embodiments, the baseband circuitry  804  may include a third generation (3G) baseband processor  804 A, a fourth generation (4G) baseband processor  804 B, a fifth generation (5G) baseband processor  804 C, or other baseband processor(s)  804 D for other existing generations, generations in development, or generations to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry  804  (e.g., one or more of the baseband processors  804 A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry  806 . In other embodiments, some or all of the functionality of the baseband processors  804 A-D may be included in modules stored in a memory  804 G and executed via a Central Processing Unit (CPU)  804 E. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry  804  may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry  804  may include convolution, tail-biting convolution, turbo, Viterbi, or Low-Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. 
     In some embodiments, the baseband circuitry  804  may include one or more audio digital signal processor(s) (DSP(s))  804 F. The audio DSP(s)  804 F may be or include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments. Components of the baseband circuitry  804  may be suitably combined in a single chip or a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry  804  and the application circuitry  802  may be implemented together such as, for example, on a system on a chip (SOC). 
     In some embodiments, the baseband circuitry  804  may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry  804  may support communication with an evolved universal terrestrial radio access network (EUTRAN) or other wireless metropolitan area networks (WMANs), a wireless local area network (WAN), or a wireless personal area network (WPAN). Embodiments in which the baseband circuitry  804  is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. 
     The RF circuitry  806  may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry  806  may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. The RF circuitry  806  may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry  808  and provide baseband signals to the baseband circuitry  804 . The RF circuitry  806  may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry  804  and provide RF output signals to the FEM circuitry  808  for transmission. 
     In some embodiments, the receive signal path of the RF circuitry  806  may include mixer circuitry  806   a , amplifier circuitry  806   b , and filter circuitry  806   c . In some embodiments, the transmit signal path of the RF circuitry  806  may include the filter circuitry  806   c  and the mixer circuitry  806   a , The RF circuitry  806  may also include synthesizer circuitry  806   d  for synthesizing a frequency for use by the mixer circuitry  806   a  of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry  806   a  of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry  808  based on the synthesized frequency provided by the synthesizer circuitry  806   d . The amplifier circuitry  806   b  may be configured to amplify the down-converted signals, and the filter circuitry  806   c  may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry  804  for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, the mixer circuitry  806   a  of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the mixer circuitry  806   a  of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry  806   d  to generate RF output signals for the FEM circuitry  808 . The baseband signals may be provided by the baseband circuitry  804  and may be filtered by the filter circuitry  806   c.    
     In some embodiments, the mixer circuitry  806   a  of the receive signal path and the mixer circuitry  806   a  of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry  806   a  of the receive signal path and the mixer circuitry  806   a  of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry  806   a  of the receive signal path and the mixer circuitry  806   a  of the transmit signal path may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry  806   a  of the receive signal path and the mixer circuitry  806   a  of the transmit signal path may be configured for super-heterodyne operation. 
     In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternative embodiments, the RF circuitry  806  may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry  804  may include a digital baseband interface to communicate with the RF circuitry  806 . 
     In some dual-mode embodiments, separate radio integrated circuitry (IC) circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the synthesizer circuitry  806   d  may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect, as other types of frequency synthesizers may be suitable. For example, the synthesizer circuitry  806   d  may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. 
     The synthesizer circuitry  806   d  may be configured to synthesize an output frequency for use by the mixer circuitry  806   a  of the RF circuitry  806  based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry  806   d  may be a fractional N/N+1 synthesizer. 
     In some embodiments, frequency input may be provided by a voltage-controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry  804  or the application circuitry  802  depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the application circuitry  802 . 
     The synthesizer circuitry  806   d  of the RF circuitry  806  may include a divider, a delay-locked loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle. 
     In some embodiments, the synthesizer circuitry  806   d  may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (e.g., fLO). In some embodiments, the RF circuitry  806  may include an IQ/polar converter. 
     The FEM circuitry  808  may include a receive signal path which may include circuitry configured to operate on RF signals received from the one or more antennas  810 , amplify the received signals, and provide the amplified versions of the received signals to the RF circuitry  806  for further processing. The FEM circuitry  808  may also include a transmit signal path which may include circuitry configured to amplify signals provided by the RF circuitry  806  for transmission by one or more of the one or more antennas  810 . In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry  806 , solely in the FEM circuitry  808 , or in both the RF circuitry  806  and the FEM circuitry  808 . 
     In some embodiments, the FEM circuitry  808  may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry  808  may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry  808  may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry  806 ). The transmit signal path of the FEM circuitry  808  may include a power amplifier (PA) to amplify input RF signals (e.g., provided by the RF circuitry  806 ), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas  810 ). 
     In some embodiments, the PMC  812  may manage power provided to the baseband circuitry  804 . In particular, the PMC  812  may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC  812  may often be included when the device  800  is capable of being powered by a battery, for example, when the device  800  is included in a UE. The PMC  812  may increase the power conversion efficiency while providing desirable implementation size and heat dissipation characteristics. 
       FIG.  8    shows the PMC  812  coupled only with the baseband circuitry  804 . However, in other embodiments, the PMC  812  may be additionally or alternatively coupled with, and perform similar power management operations for, other components, such as, but not limited to, the application circuitry  802 , RF circuitry  806 , or FEM circuitry  808 . 
     In some embodiments, the PMC  812  may control, or otherwise be part of, various power-saving mechanisms of the device  800 . For example, if the device  800  is in an RRC Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device  800  may power down for brief intervals of time and thus save power. 
     If there is no data traffic activity for an extended period of time, then the device  800  may transition off to an RRC_Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device  800  goes into a very low-power state and it performs paging where it periodically wakes up to listen to the network and then powers down again. The device  800  may not receive data in this state; in order to receive data, it transitions back to the RRC Connected state. 
     An additional power-saving mode may allow the device  800  to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device  800  is totally unreachable by the network and may power down completely. Any data sent during this time incurs a large delay, and it is assumed that the delay is acceptable. 
     Processors of the application circuitry  802  and processors of the baseband circuitry  804  may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry  804 , alone or in combination, may be used to execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry  802  may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE/RAN node, described in further detail below. 
       FIG.  9    illustrates example interfaces of the baseband circuitry  804  in accordance with some embodiments. As discussed above, the baseband circuitry  804  of  FIG.  8    may comprise processors  804 A- 804 E and a memory  804 G utilized by said processors. Each of the processors  804 A- 804 E may include a memory interface,  904 A- 904 E, respectively, to send/receive data to/from the memory  804 G. 
     The baseband circuitry  804  may further include one or more interfaces to communicatively couple to other circuitries/devices, such as a memory interface  912  (e.g., an interface to send/receive data to/from memory external to the baseband circuitry  804 ), an application circuitry interface  914  (e.g., an interface to send/receive data to/from the application circuitry  802  of  FIG.  8   ), an RF circuitry interface  916  (e.g., an interface to send/receive data to/from the RF circuitry  806  of  FIG.  8   ), a wireless hardware connectivity interface  918  (e.g., an interface to send/receive data to/from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy). Wi-Fi® components, and other communication components), and a power management interface  920  (e.g., an interface to send/receive power or control signals to/from the PMC  812 ). 
       FIG.  10    is an illustration of a control-plane protocol stack in accordance with some embodiments. In this embodiment, a control plane  1000  is shown as a communications protocol stack between the UE  101  (or alternatively, the UE  102 ), the macro RAN node  111  (or alternatively, the LP RAN node  112 ), and the MME  121 . 
     A PHY layer  1001  may transmit or receive information used by a MAC layer  1002  over one or more air interfaces. The PHY layer  1001  may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as an RRC layer  1005 . The PHY layer  1001  may still further perform error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, modulation/demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and Multiple-Input Multiple-Output (MIMO) antenna processing. 
     The MAC layer  1002  may perform mapping between logical channels and transport channels, multiplexing of MAC service data units (SDUs) from one or more logical channels onto transport blocks (TBs) to be delivered to the PHY layer  1001  via transport channels, de-multiplexing of MAC SDUs to one or more logical channels from transport blocks (TBs) delivered from the PHY layer  1001  via transport channels, multiplexing of MAC SDUs onto TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), and logical channel prioritization. 
     An RLC layer  1003  may operate in a plurality of modes of operation, including Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer  1003  may execute transfer of upper-layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation, and reassembly of RLC SDUs for UM and AM data transfers. The RLC layer  1003  may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment. 
     A PDCP layer  1004  may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper-layer PDUs at the re-establishment of lower layers, eliminate duplicates of lower-layer SDUs at the re-establishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control-plane data, perform integrity protection and integrity verification of control-plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.). 
     The main services and functions of the RRC layer  1005  may include broadcast of system information (e.g., included in Master Information Blocks (MIBs) or System Information Blocks (SIBs)) related to the non-access stratum (NAS); broadcast of system information related to the access stratum (AS); paging, establishment, maintenance, and release of an RRC connection between the UE and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release); establishment, configuration, maintenance, and release of point-to-point Radio Bearers; security functions including key management; inter-radio access technology (RAT) mobility; and measurement configuration for UE measurement reporting. Said MIBs and SIBs may comprise one or more information elements (IEs), which may each comprise individual data fields or data structures. 
     The UE  101  and the macro RAN node  111  may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange control-plane data via a protocol stack comprising the PITY layer  1001 , the MAC layer  1002 , the RLC layer  1003 , the PDCP layer  1004 , and the RRC layer  1005 . 
     Non-access stratum (NAS) protocols  1006  form the highest stratum of the control plane  1000  between the UE  101  and the MME  121 . The NAS protocols  1006  support the mobility of the UE  101  and the session management procedures to establish and maintain IP connectivity between the UE  101  and the P-GW  123 . 
     An S1 Application Protocol (S1-AP) layer  1015  may support the functions of the S1 interface and comprise Elementary Procedures (EPs). An EP is a unit of interaction between the macro RAN node  111  and the CN  120 . The S1-AP layer  1015  services may comprise two groups: UE-associated services and non-UE-associated services. These services perform functions including, but not limited to, E-UTRAN Radio Access Bearer (E-FAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer. 
     A Stream Control Transmission Protocol (SCTP) layer (alternatively referred to as an SCTP/IP layer)  1014  may ensure reliable delivery of signaling messages between the macro RAN node  111  and the MME  121  based, in part, on the IP protocol, supported by an IP layer  1013 . An L2 layer  1012  and an L1 layer  1011  may refer to communication links (e.g., wired or wireless) used by the macro RAN node  111  and the MME  121  to exchange information. 
     The macro RAN node  111  and the MME  121  may utilize an S1-MME interface to exchange control-plane data via a protocol stack comprising the L1 layer  1011 , the L2 layer  1012 , the IP layer  1013 , the SCTP layer  1014 , and the S1-AP layer  1015 , 
       FIG.  11    is an illustration of a user-plane protocol stack in accordance with some embodiments. In this embodiment, a user plane  1100  is shown as a communications protocol stack between the UE  101  (or alternatively, the UE  102 ), the macro RAN node  111  (or alternatively, the LP RAN node  112 ), the S-GW  122 , and the P-GW  123 . The user plane  1100  may utilize at least some of the same protocol layers as the control plane  1000 . For example, the UE  101  and the macro RAN node  111  may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange user-plane data via a protocol stack comprising the PHY layer  1001 , the MAC layer  1002 , the RLC layer  1003 , and the PDCP layer  1004 . 
     A General Packet Radio Service (GPRS) Tunneling Protocol for the user plane (GTP-U) layer  1104  may be used for carrying user data within the GPRS core network and between the radio access network and the core network. The user data transported can be packets in any of IPv4, IPv6, or PPP formats, for example. A UDP and IP security (UDP/IP) layer  1103  may provide checksums for data integrity, port numbers for addressing different functions at the source and destination, and encryption and authentication of the selected data flows. The macro RAN node  111  and the S-GW  122  may utilize an S1-U interface to exchange user-plane data via a protocol stack comprising the L1 layer  1011 , the L2 layer  1012 , the UDP/IP layer  1103 , and the GTP-U layer  1104 . The S-GW  122  and the P-GW  123  may utilize an S5/S8a interface to exchange user-plane data via a protocol stack comprising the L1 layer  1011 , the L2 layer  1012 , the UDP/IP layer  1103 , and the GTP-U layer  1104 . As discussed above with respect to  FIG.  10   , NAS protocols support the mobility of the UE  101  and the session management procedures to establish and maintain IP connectivity between the UE  101  and the P-GW  123 . 
       FIG.  12    is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically,  FIG.  12    shows a diagrammatic representation of hardware resources  1200  including one or more processors (or processor cores)  1210 , one or more memory/storage devices  1220 , and one or more communication resources  1230 , each of which may be communicatively coupled via a bus  1240 . For embodiments where node virtualization (e.g., Network Functions Virtualization (NFV)) is utilized, a hypervisor  1202  may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources  1200 . 
     The processors  1210  (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application-specific integrated circuit (ASIC), a radio-frequency integrated circuit (WIC), another processor, or any suitable combination thereof) may include, for example, a processor  1212  and a processor  1214 . 
     The memory/storage devices  1220  may include main memory, disk storage, or any suitable combination thereof. The memory/storage devices  1220  may include, but are not limited to, any type of volatile or non-volatile memory such as dynamic random-access memory (DRAM), static random-access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state storage, etc. 
     The communication resources  1230  may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices  1204  or one or more databases  1206  via a network  1208 . For example, the communication resources  1230  may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, NFC components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components. 
     Instructions  1250  may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors  1210  to perform any one or more of the methodologies discussed herein. The instructions  1250  may reside, completely or partially, within at least one of the processors  1210  (e.g., within the processor&#39;s cache memory), within the memory/storage devices  1220 , or any suitable combination thereof. Furthermore, any portion of the instructions  1250  may be transferred to the hardware resources  1200  from any combination of the peripheral devices  1204  or the databases  1206 . Accordingly, the memory of the processors  1210 , the memory/storage devices  1220 , the peripheral devices  1204 , and the databases  1206  are examples of computer-readable and machine-readable media. 
       FIG.  13    illustrates components of the CN  120  in accordance with some embodiments. The components of the CN  120  may be implemented in one physical node or separate physical nodes including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some embodiments. Network Functions Virtualization (NFV) is utilized to virtualize any or all of the above-described network node functions via executable instructions stored in one or more computer-readable storage media (described in further detail below). A logical instantiation of the CN  120  may be referred to as a network slice  1301 . A logical instantiation of a portion of the CN  120  may be referred to as a network sub-slice  1302  (e.g., the network sub-slice  1302  is shown to include the P-GW  123  and the PCRF  126 ). 
     NFV architectures and infrastructures may be used to virtualize one or more network functions, alternatively performed by proprietary hardware, onto physical resources comprising a combination of industry-standard server hardware, storage hardware, or switches. In other words, NFV systems can be used to execute virtual or reconfigurable implementations of one or more EPC components/functions. 
       FIG.  14    is a block diagram illustrating components, according to some example embodiments, of a system  1400 . The system  1400  is illustrated as including a virtualized infrastructure manager (VIM)  1402 , a network functions virtualization infrastructure (NFVI)  1404 , a VNF manager (VNFM)  1406 , virtualized network functions (VNFs)  1408 , an element manager (EM)  1410 , an NFV Orchestrator (NFVO)  1412 , and a network manager (NM)  1414 . 
     The VIM  1402  manages the resources of the NFVI  1404 . The NFVI  1404  can include physical or virtual resources and applications (including hypervisors) used to execute the system  1400 . The VIM  1402  may manage the life cycle of virtual resources with the NFVI  1404  (e.g., creation, maintenance, and teardown of virtual machines (VMs) associated with one or more physical resources); track VM instances; track performance, faults, and security of VM instances and associated physical resources; and expose VM instances and associated physical resources to other management systems. 
     The VNFM  1406  may manage the VNFs  1408 . The VNFs  1408  may be used to execute EPC components/functions. The VNFM  1406  may manage the life cycle of the VNFs  1408  and track performance, faults, and security of the virtual aspects of the VNFs  1408 . The EM  1410  may track the performance, faults, and security of the functional aspects of the VNFs  1408 . The tracking data from the VNFM  1406  and the EM  1410  may comprise, for example, performance measurement (PM) data used by the VIM  1402  or the NFVI  1404 . Both the VNFM  1406  and the EM  1410  can scale up/down the quantity of VNFs  1408  of the system  1400 . 
     The NFVO  1412  may coordinate, authorize, release, and engage resources of the NFVI  1404  in order to provide the requested service (e.g., to execute an EPC function, component, or slice). The NM  1414  may provide a package of end-user functions with the responsibility for the management of a network, which may include network elements with VNFs, non-virtualized network functions, or both (management of the VNFs may occur via the EM  1410 ). 
     Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client, or server computer system) or one or more hardware processors may be configured by firmware or software, instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a communication device-readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations. 
     Accordingly, the term “module” is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time. 
     While as described herein, non-transitory computer-readable media or a communication device-readable medium may be discussed as a single medium, the term “communication device-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions used by circuitry to implement described operations. 
     The term “communication device-readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by a communication device and that cause the communication device to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting communication device-readable medium examples may include solid-state memories, and optical and magnetic media, Specific examples of communication device-readable media may include non-volatile memory, such as semiconductor memory devices (e.g., EPROM, EEPROM) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; RAM; and CD-ROM and DVD-ROM disks. In some examples, communication device-readable media may include non-transitory communication device-readable media. In some examples, communication device-readable media may include communication device-readable media that is not a transitory propagating signal. 
     The instructions may further be transmitted or received over a communications network using a transmission medium via a network interface device utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), HTTP, etc.). Example communications networks may include a local area network (LAN), a wide area network (WAN), a packet data network the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone Service (POTS) networks, wireless data networks (e.g., IEEE 1002.11 family of standards known as Wi-Fi®, IEEE 1002.16 family of standards known as WiMAX®), IEEE 1002.15.4 family of standards, an LIE family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, or peer-to-peer (P2P) networks, among others. In an example, the network interface device may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network. In an example, the network interface device may include a plurality of antennas to wirelessly communicate using single-input multiple-output (SIMO), MIMO, or multiple-input single-output (MISO) techniques. In some examples, the network interface device may wirelessly communicate using Multiple-User MIMO techniques. The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the communication device, and includes digital or analog communications signals or other intangible media to facilitate communication of such software. 
     Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read-only memory (ROM), RAM, magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device. 
     Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. 
     Although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. 
     In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended; that is, a system, UE, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim is still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Metadata:
Filing Date: 20180620
Publication Date: 20240109
Grant Date: 20240109
Priority Date: 20170620
Inventors: SIROTKIN, ALEXANDER
HAN, Jaemin
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W68/005", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L1/1642", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W80/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L1/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L1/1685", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W68/005", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L1/1642", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/1685", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/1896", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W68/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W80/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/1896", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/1642", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W80/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/18", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 64737373