WO2022197312A1

WO2022197312A1 - Link adaptation for multiple connections

Info

Publication number: WO2022197312A1
Application number: PCT/US2021/023290
Authority: WO
Inventors: Stefano PARIS; Teemu Mikael VEIJALAINEN; Qiyang ZHAO; Hans Thomas HÖHNE; Kalle Petteri KELA
Original assignee: Nokia Technologies Oy; Nokia Of America Corporation
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2022-09-22

Abstract

One method may include receiving parameters for rules at a user equipment from a first network node. The method may include determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The method may include determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. In addition, the method may include proposing a block error rate offset to one or more of the first network node and the second network node, and determining that the first network node should transmit in the downlink transmission. The method may include informing the first network node that it is recommended to transmit in the downlink transmission.

Description

TITLE: LINK ADAPTATION FOR MULTIPLE CONNECTIONS FIELD: [0001] Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as Long Term Evolution (LTE) or fifth generation (5G) radio access technology or new radio (NR) access technology, or other communications systems. For example, certain example embodiments may relate to apparatuses, systems, and/or methods for link adaptation for multiple connections. BACKGROUND: [0002] Examples of mobile or wireless telecommunication systems may include the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), LTE-Advanced (LTE-A), MulteFire, LTE-A Pro, and/or fifth generation (5G) radio access technology or new radio (NR) access technology. Fifth generation (5G) wireless systems refer to the next generation (NG) of radio systems and network architecture.5G is mostly built on a new radio (NR), but the 5G (or NG) network can also build on E-UTRAN radio. It is estimated that NR will provide bitrates on the order of 10-20 Gbit/s or higher, and will support at least enhanced mobile broadband (eMBB) and ultra-reliable low-latency-communication (URLLC) as well as massive machine type communication (mMTC). NR is expected to deliver extreme broadband and ultra-robust, low latency connectivity and massive networking to support the Internet of Things (IoT). With IoT and machine-to-machine (M2M) communication becoming more widespread, there will be a growing need for networks that meet the needs of lower power, low data rate, and long battery life. It is noted that, in 5G, the nodes that can provide radio access functionality to a user equipment (i.e., similar to Node B in UTRAN or eNB in LTE) are named gNB when built on NR radio and named NG-eNB when built on E-UTRAN radio. SUMMARY: [0003] Some example embodiments may be directed to a method. The method may include receiving parameters for rules at a user equipment from a first network node. The method may also include determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The method may further include determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. Further, the method may include proposing a block error rate offset to one or more of the first network node and the second network node. In addition, the method may include determining that the first network node should transmit in the downlink transmission. The method may also include informing the first network node that it is recommended to transmit in the downlink transmission. [0004] Other example embodiments may be directed to an apparatus. The apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and computer program code may be configured to, with the at least one processor, cause the apparatus at least to receive parameters for rules from a first network node. The apparatus may also be caused to determine a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the apparatus. The apparatus may further be caused to determine, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. In addition, the apparatus may be caused to propose a block error rate offset to one or more of the first network node and the second network node. Further, the apparatus may be caused to determine that the first network node should transmit in the downlink transmission. The apparatus may also be caused to inform the first network node that it is recommended to transmit in the downlink transmission. [0005] Other example embodiments may be directed to an apparatus. The apparatus may include means for receiving parameters for rules at a user equipment from a first network node. The apparatus may also include means for determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The apparatus may further include means for determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. Further, the apparatus may include means for proposing a block error rate offset to one or more of the first network node and the second network node. In addition, the apparatus may include means for determining that the first network node should transmit in the downlink transmission. The apparatus may also include means for informing the first network node that it is recommended to transmit in the downlink transmission. [0006] In accordance with other example embodiments, a non-transitory computer readable medium may be encoded with instructions that may, when executed in hardware, perform a method. The method may include determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The method may further include determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. Further, the method may include proposing a block error rate offset to one or more of the first network node and the second network node. In addition, the method may include determining that the first network node should transmit in the downlink transmission. The method may also include informing the first network node that it is recommended to transmit in the downlink transmission. [0007] Other example embodiments may be directed to a computer program product that performs a method. The method may include determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The method may further include determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. Further, the method may include proposing a block error rate offset to one or more of the first network node and the second network node. In addition, the method may include determining that the first network node should transmit in the downlink transmission. The method may also include informing the first network node that it is recommended to transmit in the downlink transmission. [0008] Other example embodiments may be directed to an apparatus that may include circuitry configured to receive parameters for rules from a first network node. The apparatus may also include circuitry configured to determine a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the apparatus. The apparatus may further include circuitry configured to determine, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. Further, the apparatus may include circuitry configured to propose a block error rate offset to one or more of the first network node and the second network node. In addition, the apparatus may include circuitry configured to determine that the first network node should transmit in the downlink transmission. The apparatus may also include circuitry configured to inform the first network node that it is recommended to transmit in the downlink transmission. [0009] Certain example embodiments may be directed to a method. The method may include computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The method may also include determining a block error rate offset for each transmission leg. The method may further include communicating the block error rate offset to a network node hosting one or more transmission legs. [0010]Other example embodiments may be directed to an apparatus. The apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and computer program code may be configured to, with the at least one processor, cause the apparatus at least to compute a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The apparatus may also be caused to determine a block error rate offset for each transmission leg. The apparatus may further be caused to communicate the block error rate offset to a network node hosting one or more transmission legs. [0011]Other example embodiments may be directed to an apparatus. The apparatus may include means for computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The apparatus may also include means for determining a block error rate offset for each transmission leg. The apparatus may further include means for communicating the block error rate offset to a network node hosting one or more transmission legs [0012] In accordance with other example embodiments, a non-transitory computer readable medium may be encoded with instructions that may, when executed in hardware, perform a method. The method may include computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The method may also include determining a block error rate offset for each transmission leg. The method may further include communicating the block error rate offset to a network node hosting one or more transmission legs. [0013]Other example embodiments may be directed to a computer program product that performs a method. The method may include computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The method may also include determining a block error rate offset for each transmission leg. The method may further include communicating the block error rate offset to a network node hosting one or more transmission legs. [0014]Other example embodiments may be directed to an apparatus that may include circuitry configured to compute a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The apparatus may also include circuitry configured to determine a block error rate offset for each transmission leg. The apparatus may further include circuitry configured to communicate the block error rate offset to a network node hosting one or more transmission legs. BRIEF DESCRIPTION OF THE DRAWINGS: [0015]For proper understanding of example embodiments, reference should be made to the accompanying drawings, wherein: [0016]FIG.1 illustrates an example an example of link adaptation. [0017]FIG.2 illustrates an example multi connectivity link adaptation in multi radio dual connectivity (MR-DC), according to certain example embodiments. [0018]FIG. 3 illustrates an example multi connectivity link adaptation (MCLA) algorithm, according to certain example embodiments. [0019]FIG.4 illustrates an example method for computing the block error rate (BLER) offset for the legs serving data radio bearer (DRB) of a user equipment (UE), according to certain example embodiments. [0020]FIG. 5 illustrates an example deep neural network (DNN) model, according to certain example embodiments. [0021]FIG. 6 illustrates an example method to compute a modulation coding scheme (MCS), according to certain example embodiments. [0022]FIG.7 illustrates an example procedure to coordinate BLER targets of two legs for downlink transmissions, according to certain example embodiments. [0023]FIG.8 illustrates an example UE-driven procedure, according to certain example embodiments. [0024]FIG. 9 illustrates an example heat map, according to certain example embodiments. [0025]FIG.10 illustrates an example graph of a gain (η) in spectral efficiency of DC coupled with multi connectivity link adaptation (MCLA), according to certain example embodiments. [0026]FIG.11 illustrates an example flow diagram of a method, according to certain example embodiments. [0027]FIG. 12 illustrates an example flow diagram of another method, according to certain example embodiments. [0028]FIG. 13(a) illustrates an apparatus, according to certain example embodiments. [0029]FIG. 13(b) illustrates another apparatus, according to certain example embodiments. DETAILED DESCRIPTION: [0030] It will be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. The following is a detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for link adaptation for multiple connections. [0031]The features, structures, or characteristics of example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the usage of the phrases “certain embodiments,” “an example embodiment,” “some embodiments,” or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment. Thus, appearances of the phrases “in certain embodiments,” “an example embodiment,” “in some embodiments,” “in other embodiments,” or other similar language, throughout this specification do not necessarily refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. [0032]FIG. 1 illustrates an example of link adaptation. Specifically, FIG. 1 illustrates an inner-loop link adaptation (ILLA) and an outer-loop link adaptation (OLLA). As illustrated in FIG. 1, user equipment (UE) may measure reference signals (e.g., channel state information reference signals (CSI-RS)) and report channel quality indicator (CQI) to the network. CQIs may map to a modulation and coding scheme (MCS). In some cases, OLLA may be used to overcome inaccuracies and reach desired average target block error rate (BLER). There, the CSI offset dB value may be tuned based on hybrid automatic repeat request (HARQ) acknowledgement/non- acknowledgment (ACK/NACK) feedback. [0033] In certain cases, when packets are being duplicated, separate gNBs may be performing their own link adaptation independently. For dual connectivity (DC) coordination, 3^rd Generation Partnership Project (3GPP) specifies assistance information, where the assisting gNB may provide information about past transmissions to the gNB that is hosting the packet data convergence protocol (PDCP) entity. Assistance information may include information such as average CQI, average HARQ failures, average HARQ retransmissions, and/or downlink/uplink (DL/UL) radio quality index. This information may be used for packet duplication decision making at the gNB hosting the duplicating PDCP entity. [0034]Ultra-reliable low-latency communication (URLLC) may include different performance objectives that are related to end-to-end (E2E) packet error probability (PEP) (e.g. 1e-3…9) and latency constrain

(e.g. 1…100ms). Sometimes, these two objectives may conflict with each other since reliability maximization and latency minimization may be achieved by selecting a low order and high order MCS, respectively. In the radio access network (RAN), these two objectives may have an overall objective of maximizing spectral efficiency (SE) while satisfying the ^{constraint in (1) below.}

[0035]However, in certain cases, when duplication is enabled, the target PEP

may be split across transmission legs, since multiple copies of the same packet may be transmitted, which makes it possible to achieve higher spectral efficient transmissions. In some cases, it may be assumed that two transmission legs are activated. If both legs optimize the objective independently, under the assumption of statistically independent errors on the two legs, which may be relisting since legs may be set on different carrier frequencies, and resource allocation may be performed independently, the error probability may become . Thus, the PEP

experienced by the E2E connection may be much lower than the objective, which may result in inefficient resource usage. Accordingly, certain example embodiments may provide a way to coordinate the reliability budgets among multiple legs to satisfy the objective with duplicated transmissions. [0036]Multi-radio dual connectivity (MR-DC) may be a generalization defined in 3GPP of the intra-evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) DC. In MR-DC, a multiple Rx/Tx capable UE may be configured to utilize resources provided by two different nodes connected via non-ideal backhaul; one providing NR access and the other providing either E-UTRA or NR access. One node may act as the master node (MgNB), and the other may act as the secondary node (SgNB). The MgNB and SgNB may be connected via a network interface, and at least the MgNB may be connected to the core network. [0037]Within the MR-DC architecture, 3GPP defines support for data duplication at the PDCP layer to increase the redundancy of packet transmissions by using all resources provided by MR-DC. Even though each leg may run the link adaptation algorithm independently from other legs, and each leg might select a distinct MCS, the BLER target may be shared across all available legs that are used to transmit the same protocol data unit (PDU). In DL transmissions, the entity entitled to decide how to share the BLER target across all legs may be the MgNB, which hosts the PDCP layer, whereas for UL transmissions, the UE may use a decision function provided by the network to select the appropriate BLER target for each leg. [0038]Certain example embodiments may provide a method for coordinating link adaptation in MR-DC to improve SE. According to certain example embodiments, this may be achieved by computing for each leg, a BLER target given the PEP target (packet error probability) for the data radio bearer (DRB). In some example embodiments, the PEP target may be shared among the active transmission legs when PDCP duplication works on top of MR-DC, since the same copy of a PDU may be replicated over the legs. Once the BLER target for each leg is computed, a BLER offset may be communicated to the instance of the adaptation (LA) algorithm running on the corresponding leg. For instance, according to certain example embodiments, the MgNB, which may host the PDCP layer, may communicate the BLER offset to every leg (including the SgNB). [0039]Certain example embodiments may provide the ability for the network and/or UE to communicate a pre-computed BLER offset to the active transmission legs. This may allow for a coordinated adaptation of the transmission rate of the active legs to achieve the desired PEP for the DRB. This may use the definition of a messages and procedures for the communication, and the BLER offset. [0040]According to certain example embodiments, the network and/or UE may communicate a pre-computed BLER offset to the active transmission legs. This may allow for a coordinated adaptation of the transmission rate of the active legs to achieve the desired PEP for the DRB. This may also use the definition of a messages and procedures for the communication and the BLER offset. [0041]According to certain example embodiments, the BLER offset may be computed for each leg starting from a target PEP. For instance, in certain example embodiments, a BLER target may be computed for each active leg so that the joint error rate of the transmissions occurring across all available legs may match the original PEP target. Thus, according to certain example embodiments, it may be possible to relax the BLER target by exploiting the redundancy offered by data duplication in order to use higher order MCSs that eventually improve SE. Certain example embodiments may also be used in combination with a data duplication scheme such as, for example, PDCP-layer duplication or higher layer duplication (i.e., PDCP). [0042] In certain example embodiments, with respect to the baseline solution where the BLER target of different legs are decided independently and LA algorithms are executed independently, the work of LA algorithms may be coordinated to use higher order MCS, and at the same time, meet the PEP target. Thus, according to certain example embodiments, it may be possible to improve the SE by transmitting the duplicate copies of the same PDCP PDU faster. In some cases, this may involve using new signaling to inform legs of their BLER targets, and procure to handle the new information. [0043]According to certain example embodiments, the UE may propose the BLER offset to the proposed active transmission legs’ nodes. In certain example embodiments, the signaling may allow a node to derive whether it has been proposed as the only leg, or one of many. This may enable the nodes to take speedy decisions on transmissions, where latency requirements are so low that inter-node coordination may be difficult to achieve. [0044]Certain example embodiments may provide a method to compute the BLER and MCS for each leg, and other example embodiments may provide procedures to coordinate LA across multiple legs. In computing the BLER and MCS for each leg, different embodiments may be provided based on solutions obtained while solving an optimization problem, and heuristic approaches based on machine learning. In both cases, it may be possible to maximize the SE while not violating packet error rate and URLLC application survival time targets. With coordinating LA across multiple legs, certain example embodiments may provide various alternative solutions including, for example, a network-based procedure and a UE-based procedure. [0045]FIG.2 illustrates an example multi connectivity link adaptation in MR- DC, according to certain example embodiments. As illustrated in FIG. 2, in a MR-DC scenario, a UE may be served by up to four transmission legs. A leg may be composed of radio link control (RLC), medium access control (MAC), and PHY layers configured on different carrier components. The PDCP layer may be hosted by an MgNB, which may be connected to a SgNB through an Xn interface. [0046] In certain example embodiments, once the DRB with the corresponding quality of service (QoS) parameters is configured, the MgNB may activate a certain number of legs according to the application requirements, UE, and network capabilities. As illustrated in FIG. 2, the PEP defined in the QoS parameters and the number of active legs may be used by the MCLA method to compute a BLER target/offset for one or more of the legs. In some example embodiments, the BLER target/offset of each leg, BLERMCLA(i), may be communicated to the LA(i) algorithm of the i-th leg. [0047]FIG. 3 illustrates an example multi connectivity link adaptation (MCLA) algorithm, according to certain example embodiments. In particular, FIG.3 illustrates an example MCLA algorithm where PEP is the packet error rate that may be desired to be achieved for the flow using the legs available for the transmission of PDUs. According to certain example embodiments, the MCLA may compute a BLER target BLERMCLA for each leg, and communicate it to the LA algorithm of each leg. BLER_MCLA(i), where i is the leg index, may take the form of an absolute value or an offset depending on the implementation of the function used by LA to combine it with the overall BLER target. In certain example embodiments, the BLERMCLA(i) may be communicated to i-th leg is combined (e.g., added, multiplied, etc.) with both the BLER target of ILLLA and OLLA to steer both algorithms towards BLER target computed by MCLA for the i-th leg. [0048]FIG. 4 illustrates an example method for computing the BLER offset for the legs serving DRB of a UE, according to certain example embodiments. In certain example embodiments, the method of FIG. 4 may be executed by the MgNB or the network. According to certain example embodiments, a BLER offset and MCS may be computed for the legs used to serve a UE’s DRB. For instance, in certain example embodiments, BLERMCLA(i), namely the BLER for each active leg i may be computed. As illustrated in the example of FIG.4 and described in more detail herein, at 400, input may be collected. At 405, the spectral efficiency maximization problem may be solved. Further, at 410, the BLER offset may be computed for each leg

. Once the MCS for each leg has been computed, the BLER target for each leg may be obtained from the variable , and the BLER offset for leg

can be computed as the difference between the overall BLER target and the leg error probability stored in variable . In

addition, at 415, the BLER offset may be communicated to the

node that hosts leg i. [0049]As described herein, the input parameters of certain example embodiments may be defined as that shown in Table 1. Table 1: Input parameters

[0050]According to certain example embodiments, the BLER may be computed for each leg to maximize SE while satisfying the reliability target of the DRB defined by the PEP target. For instance, a binary decision variable may be defined as

for each leg and MCS

(variable

if leg i should use MCS m), real variable to indicate the

BLER target for leg

and

the maximum SE. The SE may be maximized by solving the following problem (P1) as shown below.

[0051] It is observed that the problem (P1) is not linear due to the first set of constraints

. However, they can be linearized as follows:

Further, the auxiliary variable may be defined for each leg

and problem (P1) may be redefined as shown in (P2) below:

where M may be a sufficiently large number (e.g., M = −n). Problem (P2), which is a mixed integer linear program, may be solved using standard techniques such as the Branch and Bound algorithm or sub-gradient methods. According to certain example embodiments, once the MCS for each leg has been computed, the BLER target for each leg may be obtained from the variable

and the BLER offset for leg

may be computed as the difference between the overall BLER target and the leg error probability stored in variable .

[0052] In certain example embodiments, once the BLER offset is communicated to each leg, the relationship among CQI, MCS, delay (or SE), and BLER may be learned to compute the optimal MCS that satisfies the BLER and delay targets. Delay here may refer to the transmission time of a PDU/packet over the NR air interface. For instance, in certain example embodiments, this may be accomplished via an MCLA learning phase and/or an MCLA execution phase, which may be executed after the computation of the BLER for each leg, as shown in FIG. 4. [0053]FIG.5 illustrates an example deep neural network (DNN) modeling the relationship between CQI, MCS (input) and BLER, and delay (output), according to certain example embodiments. In the MCLA learning phase, the network with the support of the UE may learn the relationship among CQI, MCS, delay/SE, and BLER for each leg using a deep neural network (DNN), and communicate the learnt model to each leg. However, in certain example embodiments, the DNN may work with other differentiable functions. For instance, given a tuple composed of CQI, MCS as input, the DNN may predict the BLER and delay (or SE). [0054]According to certain example embodiments, the input may be denoted as the vector , the output as the vector (e.g., a

singleton , and the DNN as the function ,

where Θ is, for example, the vector of parameters of the DNN. According to certain example embodiments, the learning of may be performed

using the gradient descent approach with backpropagation after collecting several samples for the input ^ and output ^. Samples may be collected by gNBs with the support of the UEs, and sent to a central entity executed in the network that performs the training of the DNN. In certain example embodiments, the DNN may be trained using samples collected by any gNB and UE, since it does not depend on specific cell and UE properties. For the same reason, once the DNN has been trained in the network, it may be used by any leg of any gNB (for DL) or UE (for UL). [0055] In certain example embodiments, it may be possible to obtain samples with higher sparsity merging samples from different legs since cells and the UE may show different load, MCS, and SINR distributions. This may eventually speed up the training and increase the accuracy of DNN since more sparse samples are collected. [0056]According to certain example embodiments, in the MCLA execution phase, each leg may decide the MCS used for transmitting the packet. Further, in the MCLA execution phase, the best MCS may be selected from the input composed of CQI, delay, and BLER targets for the i-th leg. In certain example embodiments, Θ

may be designated as the vector of parameters of the trained DNN, may be a BLER target for a leg, and

^ may be the set of possible solutions. Intuitively, the method may include inverting the

. This may be achieved by solving the following constrained

optimization problem:

where is the error function (or

objective function), which is composed of the loss function and

a regularization function . Examples of loss and regularization functions

may include norms (e.g., p-norms with p={1,2}), mean squared error (MSE), and mean absolute error (MAE). For example, the loss function and regularizer may be and

respectively (T denotes the transpose vector).

[0057]FIG. 6 illustrates an example method to compute MCS for leg i from CQI, BLER target, delay, and DNN ϕ(x, Θ), according to certain example embodiments. In certain example embodiments, the method of FIG.6 may be executed by any gNB (e.g., either MgNB or SgNB). For instance, according to certain example embodiments, the optimization problem may be solved using the method illustrated in FIG. 6, which may include executing the gradient descent to find the optimum of the error function with respect a subset of the input (i.e., the MCS variable). In other words, at each iteration, the method may update the MCS until a condition or a combination of conditions (e.g., convergence, after a maximum number of iterations) is satisfied. [0058]As illustrated in the example of FIG.6, at 600, the real output to BLER target for leg i may be initialized. At 605, the input of DNNi may be initialized for leg i with CQIi, delayi, and random values for MCSi. Further, at 610, t=0 may be initialized. At 615, it may be determined whether the condition should stop. If yes, then at 620, the condition may be stopped. If no, at 625, a feed forward DNN_i may be performed to compute the intermediate output and final output. At 630, the error and its

derivative may be computed. In addition, at 635, the method may

include backpropagating error to compute a gradient with respect to the input . The method may also include, at 640, updating variables

corresponding to CQIi and MCSi. At 645, the method may include increasing t by t+1. [0059]Certain example embodiments may provide procedures to coordinate and configure the BLER target for different legs used for transmission. For instance, certain example embodiments may provide a network-driven approach where the MgNB performs the main operations, whereas in a UE- driven approach, the UE may indicate possible LA configuration(s) to the MgNB and the SgNB. It may be observed that the indication exchanged between gNBs (network-driven approach) or between UE and gNBs (UE- driven approach) may take the form of BLER target, MCS, CQI offset or any other information that is used by the LA to select the MCS. In the following, the network-driven approach is described considering indication BLER targets, whereas the UE-driven approach is described considering MCSs. [0060]FIG.7 illustrates an example procedure to coordinate the BLER targets of two legs for DL transmissions, according to certain example embodiments. In particular, FIG.7 illustrates a procedure to coordinate the BLER targets on the two legs in order to maximize spectral efficiency. The procedure may be executed periodically with a period defined as a network parameter or per packet based (for each duplicate PDU). [0061]As illustrated in FIG. 7, at 1, the MgNB (the node hosting the PDCP layer) may collect channel quality and experienced BLER from all legs. Specifically, for legs hosted by the SgNB which are not directly controlled, at 1A, the SgNB (or the second leg) may report the DL channel quality (e.g., CSI, CQI, SINR). At 1B, the SgNB may also report the BLER experienced by last transmissions including, for example, BLERE(i) (BLERE(i) may be a computed using moving average to smooth the value). At 2, the MgNB may compute the BLER target by solving problem P2 with the information collected from all legs. In certain example embodiments, the BLER offset may be computed, for example, as (i.e., the

missing amount to reach the BLER target computed by the problem P2). At 3, the MgNB may communicate the BLER offset BLERMCLA(i) to the SgNB. [0062]Further, at 4, the LA of MgNB may select the MCS using the usual parameters and the BLER offset computed for the leg BLERMCLA(1). At 5, the LA of the SgNB may select the MCS using the usual parameters and the BLER offset computed for the leg BLERMCLA(2). At 6, the PDU may be transmitted to the UE by the MgNB using the MCS computed in step 4. In addition, at 7, if the PDU is received correctly by the UE, the MgNB may send a discard command to the SgNB. Further, at 8, the PDU may be transmitted by the SgNB to the UE using the MCS computed in step 7 if PDU discard is not received. [0063]FIG.8 illustrates an example UE-driven procedure to coordinate BLER targets when the UE is carrying out the BLER split calculations, according to certain example embodiments. In particular, according to certain example embodiments, the UE may be enabled to determine how the DL transmissions should be carried out. A benefit, which is not available for the network-driven approach, is that the inter-gNB signaling may be omitted. Thus, in certain example embodiments, for very low-latency data, a UE-driven solution may be preferable. According to certain example embodiments, the UE should not be understood as being in control of the DL transmissions. Rather, the UE may be giving its recommendation to the gNBs, and the network may still be free to decide on DL transmissions on its own. Additionally, in certain example embodiments, the UE-driven procedure may limit the UL signaling by providing feedback to the gNB(s), which the UE determined to be suitable candidates for the DL transmission. In some example embodiments, limited UL signaling may be advantageous due to lower power consumption and less UL resource usage. [0064]As illustrated in FIG.8, at 1, the network may provide the UE with the algorithm, or the parameters for the algorithm to determine the target BLER split to maximize reliability. According to certain example embodiments, this signaling may be carried out as a static configuration via RRC messages. If a neural network (NN) is used, this step may include downloading the NN, or coefficients and configuring a selection of inputs for the NN. In certain example embodiments described herein, it may be assumed that one of the parameters sent by the network to the gNB is a target BLER. [0065]At 2, the UE may perform channel measurements, and determine, according to the provisioned algorithm, in what way the next DL transmission or transmissions should be taking place. For instance, in certain example embodiments, the UE may determine that the next DL transmission should be happening from both links. In this example, the BLER may be split across the links as target +x1, and target +y1, respectively. Additionally, in some example embodiments, the UE may apply algorithms as in solving P2. [0066]At 3 and 4, the UE may inform each gNB (MgNB and SgNB) of the commended offset x1 and y1, respectively. Further, at 5 and 6, each gNB may perform an MCS selection according to the signaling BLER target. Additionally, at 7 and 8, the gNB may transmit data using MCS B and MCS C, respectively. [0067]As further illustrated in FIG. 8, at 9, the UE may perform another channel measurement and algorithm calculation. For instance, in this example, the UE may determine that the MgNB should transmit in DL. At 10, the UE may inform the MgNB that the MgNB is recommended to transmit in DL, for instance, by signaling the BLER split offset as 0. Additionally, at 11, the MgNB may determine the MCS according to the target and offset at 12, the MgNB may transmit the data using MCS A. [0068] In certain example embodiments, when the UE’s channel reports are configured as periodic, and are sent to both gNBs, the UE may indicate to the gNB that no transmission is required by setting the offset as -targetBLER. Alternatively, a new dedicated flag may be set in the CSI to indicate whether both gNBs, or only one, are recommended to transmit. As mentioned, this enables for instance, a gNB which has been recommended to transmit alone, but has high load and cannot transmit, to coordinate with another gNB. In other example embodiments, the UE may determine the recommended MCS for the gNBs and indicate to the gNBs how many legs are being recommended for the transmission. In some example embodiments, instead of a recommended MCS, the UE may also report a CQI (amounting to signaling an MCS). [0069]According to certain example embodiments, a packet discarding command may be extended to signal the change of the BLER target of secondary legs, which may be used to transmit the copy of the original PDCP PDU. In particular, the procedure for DL transmissions may be executed after BLER targets/offsets are computed and communicated, as discussed above. However, in other example embodiments, a similar procedure may be used for UL communications. For instance, in certain example embodiments, the PDCP entity in the MgNB may transmit a copy of the PDCP PDU to all RLC entities. In addition, the MgNB may be implemented to delay the sending of copies to other RLC entities in order to allow time for discarding after acknowledgement. [0070] In other example embodiments, the PDCP entity in the MgNB may transmit the original PDCP PDU using the RLC entity of the first leg, and wait for the transmission outcome. According to certain example embodiments, if the RLC entity acknowledges the transmission of a PDCP PDU, the PDCP entity in the MgNB may indicate to the other RLC entity(ies) to discard it. On the other hand, if the RLC entity communicates the loss of a PDCP PDU, the PDCP entity in the MgNB may indicate to the other RLC entity(ies) to decrease their BLER target. [0071] In certain example embodiments, new signaling may be used to communicate the new BLER target/offset and/or to indicate the use of a pre- configured default BLER target. For example, a setup with two legs and overall PEP=10^-4 may be considered. It may be assumed that the best PEP split is to have BLER_i=10^-2 i={1,2} for each leg. Transmission of the copy on the second leg may be delayed with respect to the second leg. Further, when the RLC entity of the 1^st leg communicates the loss of a PDCP PDU, the PDCP entity in the MgNB indicates to the RLC entity of the 2^nd leg to set BLER2=10- ⁶. Assuming independence of losses on the two legs, the joint BLER may still be 10^-4. [0072]According to certain example embodiments, survival time may be introduced to reduce the probability of two consecutive packet errors, which may be avoided in industrial scenarios. In certain example embodiments, survival time may be defined as the maximum delay that can be tolerated for the successful transmission of a packet, when a previous packet transmission has failed. In case survival time has been configured and a loss is detected by any RLC entity of the active legs, the RLC entity that detected the loss may decrease the BLER target and notify the loss of a PDCP PDU to MgNB. In addition, the MgNB may re-compute the BLER target for each leg to protect the next packet transmission (optional if default BLER targets are pre- computed). Further, the MgNB may indicate to the other RLC entity(ies) to decrease their BLER target. [0073] In certain example embodiments, the above steps may be carried out by the UE, and the UE may re-adjust the BLER target after loss of a PDCP PDU. For example, the RLC entity that detected the loss may decrease the BLER target. In addition, the BLER target for each leg may be re-computed to protect the next packet transmission (optional if default BLER targets are pre-computed). In certain example embodiments, these steps may be executed by the gNB for DL transmissions and by the UE for UL transmissions. Further, the UE may indicate to the gNB that BLER targets have been readjusted in order to meet survival requirements, which may help the gNB understand the UE feedback. [0074]Certain example embodiments may provide a numerical evaluation of the performance of the methods described herein. For instance, according to certain example embodiments, the numerical evaluation may provide an analysis of the performance gains of the methods described herein with respect to the use of a single connectivity (SC) where the BLER target is fixed and equal to 1-PEP. The analysis has been performed considering a DC scenario where the two legs are configured on different gNBs. For instance, certain example embodiments may measure the performance metrics including SE and reliability (R). SE may be defined as the product of the coding rate and the number of bits per symbol of the selected MCS. Additionally, R may be defined as the ratio between the number of correctly received packets and the total number of transmitted packets. The gain in spectral efficiency may be defined as follows:

[0075] In measuring the spectral efficiency of DC, it may be assumed that PDU discarding is enabled. This means that the second PDU transmission may be discarded if the first PDU has been received correctly. According to certain example embodiments, in SC for each PDU, a SINR value may be randomly generated in the range [-5;15] dB, which may correspond to the signal-to-noise ratio (SINR) experienced by the PDU on the single leg used for its transmission. Given the SINR, the highest MCS that meets the BLER target may be selected to transmit the PDU. Additionally, the BLER may be used to decide whether the PDU is received. [0076]According to certain example embodiments, in DC for each PDU, a pair of SINRs (SINR1,SINR2) may be generated each in the range [-5;15] dB. Further, the PEP target may equally split across the two legs, namely , where i={1,2} is the index of the leg. Given

the (SINR1,SINR2) pair, the highest MCS that meets the BLER target to transmit the PDU may be selected for each leg. If the transmission of the PDU succeeds using the best leg, the corresponding gNB may send a discard command to the other gNB. Otherwise the worst leg may be used for the transmission of the duplicate PDU. [0077]According to certain example embodiments, the PEP target equal to 10- ⁴ may be fixed, and 10^-8 PDUs may be generated, which corresponds to 10⁴ PDUs for each pair (SINR1,SINR2) of legs qualities. Table 2 shows the reliability of SC and DC coupled with the MCLA method described herein. It can be seen that both methods meet the reliability target of four nines. Thus, relaxing the BLER constraint when multiple legs are available for transmission may not affect the system reliability. Table 2: Reliability measured as a ratio between total received packets and total transmitted packets

[0078]FIG.9 illustrates an example heat map of the gain in spectral efficiency of Dc coupled with MCLA with respect to SC, according to certain example embodiments. In particular, FIG. 9 illustrates a gain (η) in spectral efficiency of DC coupled with MCLA with respect to SC for different (SINR1,SINR2) pairs (SINR) of the two legs. As shown in FIG. 9, in almost all conditions, solutions of certain example embodiments permit the SE of the system to be increased. The average gain, which is obtained by computing the average across all PDUs, is approximately 60%. More specifically, it can be observed that the highest gain may be obtained when the second leg is better than the first leg (i.e., the upper triangle part of the heat map), which represents the most likely scenario. In this area, the average gain is 170%. Additionally, it can be observed that when the first leg is better than the second leg, which represents an unlikely scenario, the gain is still significant. In the lower triangle part of the heat map the average gain is 10. [0079]FIG.10 illustrates an example graph of a gain (η) in spectral efficiency of DC coupled with MCLA with respect to SC for equal quality legs (SINR1=SINR2), according to certain example embodiments. As can be seen in FIG.10, the methods of certain example embodiments described herein may provide higher performance in most SINR conditions. In this case the average gain is approximately 15%. The numerical results confirm the intuition that in the presence of data duplication/multiplication, it may be more spectral efficient to transmit multiple PDUs faster than a single PDU with high reliability. Further, the loss of reliability may be compensated by the redundancy offered by the multiple PDU transmissions and at the same time the PDU is quickly served. [0080]FIG.11 illustrates an example flow diagram of a method, according to certain example embodiments. In an example embodiment, the method of FIG. 11 may be performed by a network entity, network node, or a group of multiple network elements in a 3GPP system, such as LTE or 5G-NR. For instance, in an example embodiment, the method of FIG.11 may be performed by a UE, for instance similar to apparatus 10 illustrated in FIG. 13(a). [0081]According to certain example embodiments, the method of FIG. 11 may include, at 700, receiving parameters for rules at a user equipment from a first network node. The method may also include, at 705, determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The method may further include, at 710, determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. Further, at 715, the method may include proposing a block error rate offset to one or more of the first network node and the second network node. In addition, at 720, the method may include determining that the first network node should transmit in the downlink transmission. The method may also include, at 725, informing the first network node that it is recommended to transmit in the downlink transmission. [0082]According to certain example embodiments, the method may also include performing channel measurements, and receiving a transmission from one or more of the first network node and the second network node respectively using a first modulation and coding scheme and a second modulation and coding scheme according to the block error rate target and the block error rate offset. According to other example embodiments, determining how the downlink transmission should be taking place may include determining that the downlink transmission should be taking place from the first network node according to the block error rate target and a first block error rate offset, and from the second network node according to the block error rate target and a second block error rate offset. [0083] In certain example embodiments, the method may also include re- adjusting the block error rate offset after loss of a packet, and indicating to the first network node or the second network node that the block error rate offset has been re-adjusted. [0084]FIG. 12 illustrates an example flow diagram of another method, according to certain example embodiments. In an example embodiment, the method of FIG.12 may be performed by a network entity, network node, or a group of multiple network elements in a 3GPP system, such as LTE or 5G- NR. For instance, in an example embodiment, the method of FIG. 12 may be performed by a network, an MgNB, and/or an SgNB, for instance similar to apparatus 20 illustrated in FIG.13(b). [0085]According to certain example embodiments, the method of FIG. 12 may include, at 800, computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The method may also include, at 805, determining a block error rate offset for each transmission leg. The method may further include, at 810, communicating the block error rate offset to a network node hosting one or more transmission legs. [0086]According to certain example embodiments, the method may also include computing a modulation and coding scheme that satisfies at least one of the block error rate target and a delay target. According to other example embodiments, the modulation and coding scheme is computed by a multi connectivity link adaptation learning phase comprising learning a relationship among a channel quality indicator, the modulation and coding scheme, a delay, and a block error rate. The modulation and coding scheme may also be computed by a multi connectivity link adaptation execution phase wherein each transmission leg decides the modulation and coding scheme used for transmitting a packet based on input comprising the channel quality indicator, the modulation and coding scheme, the delay, and the block error rate. According to other example embodiments, the relationship may be learned with a neural network that models a relationship among the channel quality indicator, the modulation and coding scheme, the delay, and the block error rate. According to further example embodiments, the block error rate offset is computed by solving a spectral efficiency maximization problem of the data radio bearer of the user equipment, and determining a difference between an overall block error rate target and a leg error probability. [0087] In certain example embodiments, the method may also include updating the modulation and coding scheme until a condition or a combination of conditions is satisfied. In other example embodiments, coordinating and configuring the block error rate target may include collecting channel quality and experienced block error rate from each transmission leg, wherein the block error rate target may be computed based on information collected from each transmission leg, selecting the modulation and coding scheme using the block error rate offset, the block error rate target, and the channel quality indicator, transmitting a protocol data unit to the user equipment using the selected modulation and coding scheme, and transmitting a discard command to the network node when the protocol data unit is correctly received by the user equipment. In some example embodiments, the method may further include transmitting a copy of a packet data convergence protocol data unit to a radio link control entity in the network node, and transmitting an original packet data convergence protocol data unit to the radio link control entity of a first transmission leg, and waiting for a transmission outcome. [0088]According to certain example embodiments, if the transmission of the packet data convergence protocol data unit is acknowledged, the method may further include indicating to another radio link control entity to discard the packet data convergence protocol data unit. According to other example embodiments, if the transmission of the packet data convergence protocol data unit is lost, the method may also include indicating to the another radio link control entity to decrease its block error rate target. [0089]FIG. 13(a) illustrates an apparatus 10 according to certain example embodiments. In certain example embodiments, apparatus 10 may be a node or element in a communications network or associated with such a network, such as a UE, mobile equipment (ME), mobile station, mobile device, stationary device, or other device. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in FIG.13(a). [0090] In some example embodiments, apparatus 10 may include one or more processors, one or more computer-readable storage medium (for example, memory, storage, or the like), one or more radio access components (for example, a modem, a transceiver, or the like), and/or a user interface. In some example embodiments, apparatus 10 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and/or any other radio access technologies. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in FIG.13(a). [0091]As illustrated in the example of FIG. 13(a), apparatus 10 may include or be coupled to a processor 12 for processing information and executing instructions or operations. Processor 12 may be any type of general or specific purpose processor. In fact, processor 12 may include one or more of general- purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 12 is shown in FIG. 13(a), multiple processors may be utilized according to other example embodiments. For example, it should be understood that, in certain example embodiments, apparatus 10 may include two or more processors that may form a multiprocessor system (e.g., in this case processor 12 may represent a multiprocessor) that may support multiprocessing. According to certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster). [0092]Processor 12 may perform functions associated with the operation of apparatus 10 including, as some examples, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes illustrated in FIGs.1-11. [0093]Apparatus 10 may further include or be coupled to a memory 14 (internal or external), which may be coupled to processor 12, for storing information and instructions that may be executed by processor 12. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 14 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 12, enable the apparatus 10 to perform tasks as described herein. [0094] In certain example embodiments, apparatus 10 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 12 and/or apparatus 10 to perform any of the methods illustrated in FIGs.1-11. [0095] In some example embodiments, apparatus 10 may also include or be coupled to one or more antennas 15 for receiving a downlink signal and for transmitting via an uplink from apparatus 10. Apparatus 10 may further include a transceiver 18 configured to transmit and receive information. The transceiver 18 may also include a radio interface (e.g., a modem) coupled to the antenna 15. The radio interface may correspond to a plurality of radio access technologies including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, and the like. The radio interface may include other components, such as filters, converters (for example, digital-to-analog converters and the like), symbol demappers, signal shaping components, an Inverse Fast Fourier Transform (IFFT) module, and the like, to process symbols, such as OFDMA symbols, carried by a downlink or an uplink. [0096]For instance, transceiver 18 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 15 and demodulate information received via the antenna(s) 15 for further processing by other elements of apparatus 10. In other example embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some example embodiments, apparatus 10 may include an input and/or output device (I/O device). In certain example embodiments, apparatus 10 may further include a user interface, such as a graphical user interface or touchscreen. [0097] In certain example embodiments, memory 14 stores software modules that provide functionality when executed by processor 12. The modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable combination of hardware and software. According to certain example embodiments, apparatus 10 may optionally be configured to communicate with apparatus 20 via a wireless or wired communications link 70 according to any radio access technology, such as NR. [0098]According to certain example embodiments, processor 12 and memory 14 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some example embodiments, transceiver 18 may be included in or may form a part of transceiving circuitry. [0099]For instance, in certain example embodiments, apparatus 10 may be controlled by memory 14 and processor 12 to receive parameters for rules from a first network node. Apparatus 10 may also be controlled by memory 14 and processor 12 to determine a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate for each transmission leg serving a data radio bearer of the apparatus. Apparatus 10 may further be controlled by memory 14 and processor 12 to determine, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. In addition, apparatus 10 may be controlled by memory 14 and processor 12 to propose a block error rate offset to one or more of the first network node and the second network node. Further, apparatus 10 may be controlled by memory 14 and processor 12 to determine that either the first network node should transmit in the downlink transmission. Apparatus 10 may also be controlled by memory 14 and processor 12 to inform the first network node that it is recommended to transmit in the downlink transmission. [0100]FIG. 13(b) illustrates an apparatus 20 according to certain example embodiments. In certain example embodiments, the apparatus 20 may be a node or element in a communications network or associated with such a network, such as a base station, a Node B, an evolved Node B (eNB), 5G Node B or access point, next generation Node B (NG-NB or gNB), MeNB, en-gNB, MgNB, SgNB, and/or WLAN access point, associated with a radio access network (RAN), such as an LTE network, 5G or NR. It should be noted that one of ordinary skill in the art would understand that apparatus 20 may include components or features not shown in FIG.13(b). [0101]As illustrated in the example of FIG. 13(b), apparatus 20 may include a processor 22 for processing information and executing instructions or operations. Processor 22 may be any type of general or specific purpose processor. For example, processor 22 may include one or more of general- purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 22 is shown in FIG. 13(b), multiple processors may be utilized according to other example embodiments. For example, it should be understood that, in certain example embodiments, apparatus 20 may include two or more processors that may form a multiprocessor system (e.g., in this case processor 22 may represent a multiprocessor) that may support multiprocessing. In certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster). [0102]According to certain example embodiments, processor 22 may perform functions associated with the operation of apparatus 20, which may include, for example, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 20, including processes illustrated in FIGs.1-10 and 12. [0103]Apparatus 20 may further include or be coupled to a memory 24 (internal or external), which may be coupled to processor 22, for storing information and instructions that may be executed by processor 22. Memory 24 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 24 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 24 may include program instructions or computer program code that, when executed by processor 22, enable the apparatus 20 to perform tasks as described herein. [0104] In certain example embodiments, apparatus 20 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 22 and/or apparatus 20 to perform the methods illustrated in FIGs.1-10 and 12. [0105] In certain example embodiments, apparatus 20 may also include or be coupled to one or more antennas 25 for transmitting and receiving signals and/or data to and from apparatus 20. Apparatus 20 may further include or be coupled to a transceiver 28 configured to transmit and receive information. The transceiver 28 may include, for example, a plurality of radio interfaces that may be coupled to the antenna(s) 25. The radio interfaces may correspond to a plurality of radio access technologies including one or more of GSM, NB- IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, radio frequency identifier (RFID), ultrawideband (UWB), MulteFire, and the like. The radio interface may include components, such as filters, converters (for example, digital-to- analog converters and the like), mappers, a Fast Fourier Transform (FFT) module, and the like, to generate symbols for a transmission via one or more downlinks and to receive symbols (for example, via an uplink). [0106]As such, transceiver 28 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 25 and demodulate information received via the antenna(s) 25 for further processing by other elements of apparatus 20. In other example embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some example embodiments, apparatus 20 may include an input and/or output device (I/O device). [0107] In certain example embodiment, memory 24 may store software modules that provide functionality when executed by processor 22. The modules may include, for example, an operating system that provides operating system functionality for apparatus 20. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 20. The components of apparatus 20 may be implemented in hardware, or as any suitable combination of hardware and software. [0108]According to some example embodiments, processor 22 and memory 24 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some example embodiments, transceiver 28 may be included in or may form a part of transceiving circuitry. [0109]As used herein, the term “circuitry” may refer to hardware-only circuitry implementations (e.g., analog and/or digital circuitry), combinations of hardware circuits and software, combinations of analog and/or digital hardware circuits with software/firmware, any portions of hardware processor(s) with software (including digital signal processors) that work together to cause an apparatus (e.g., apparatus 10 and 20) to perform various functions, and/or hardware circuit(s) and/or processor(s), or portions thereof, that use software for operation but where the software may not be present when it is not needed for operation. As a further example, as used herein, the term “circuitry” may also cover an implementation of merely a hardware circuit or processor (or multiple processors), or portion of a hardware circuit or processor, and its accompanying software and/or firmware. The term circuitry may also cover, for example, a baseband integrated circuit in a server, cellular network node or device, or other computing or network device. [0110] In other example embodiments, apparatus 20 may be controlled by memory 24 and processor 22 to compute a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. Apparatus 20 may also be controlled by memory 24 and processor 22 to determine a block error rate offset for each transmission leg. Apparatus 20 may further be controlled by memory 24 and processor 22 to communicate the block error rate offset to a network node hosting one or more transmission legs. [0111]Certain example embodiments may be directed to an apparatus that includes means for receiving parameters for rules from a first network node. The apparatus may also include means for determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment. The apparatus may further include means for determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg. In addition, the apparatus may include means for proposing a block error rate offset to one or more of the first network node and a second network node. Further, the apparatus may include means for determining that either the first network node should transmit in the downlink transmission. The apparatus may also include means for informing the first network node that it is recommended to transmit in the downlink transmission. [0112]Other example embodiments may be directed to an apparatus that includes means for computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment. The apparatus may also include means for determining a block error rate offset for each transmission leg. The apparatus may further include means for communicating the block error rate offset to a network node hosting one or more transmission legs. In addition, the apparatus may include means for computing a modulation and coding scheme that satisfies the block error rate target and a delay target. Further, the apparatus may include means for coordinating and configuring the block error rate target for the one or more transmission legs. [0113]Certain example embodiments described herein provide several technical improvements, enhancements, and /or advantages. In some example embodiments, it may be possible compute a BLER target for each transmission leg, and communicate the corresponding BLER offset. In doing so, it may be possible to use higher order MCS for each leg, achieve the desired joint PEP target by exploiting the spatial redundancy offered by duplication, decrease resource/PRB utilization, increase SE, and achieve the above even if latencies are so low that inter-node signaling is not possible. According to other example embodiments, it may be possible to provide ML methods to decide how to split the overall PEP target of a DRB across multiple legs in multi connectivity scenarios in order to maximize SE while meeting reliability and delay requirement(s). It may also be possible to provide new signaling and procedures to coordinate LA across multiple legs/connections, which may involve new signaling to communicate the BLER offset either to the SgNB (assisting node) or to both gNBs. Other example embodiments may provide procedures to update the ML model based on the outcome of the duplication. [0114]A computer program product may include one or more computer- executable components which, when the program is run, are configured to carry out some example embodiments. The one or more computer-executable components may be at least one software code or portions of it. Modifications and configurations required for implementing functionality of certain example embodiments may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded into the apparatus. [0115]As an example, software or a computer program code or portions of it may be in a source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers may include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers. The computer readable medium or computer readable storage medium may be a non-transitory medium. [0116] In other example embodiments, the functionality may be performed by hardware or circuitry included in an apparatus (e.g., apparatus 10 or apparatus 20), for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the functionality may be implemented as a signal, a non-tangible means that can be carried by an electromagnetic signal downloaded from the Internet or other network. [0117]According to certain example embodiments, an apparatus, such as a node, device, or a corresponding component, may be configured as circuitry, a computer or a microprocessor, such as single-chip computer element, or as a chipset, including at least a memory for providing storage capacity used for arithmetic operation and an operation processor for executing the arithmetic operation. [0118]One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with procedures in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these example embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of example embodiments. Although the above embodiments refer to 5G NR and LTE technology, the above embodiments may also apply to any other present or future 3GPP technology, such as LTE-advanced, and/or fourth generation (4G) technology. [0119]Partial Glossary [0120]3GPP 3rd Generation Partnership Project [0121]5G 5th Generation [0122]5GCN 5G Core Network [0123]BLER Block Error Rate [0124]BS Base Station [0125]DL Downlink [0126]DRB Data Radio Bearer [0127]eNB Enhanced Node B [0128]gNB 5G or Next Generation NodeB [0129] ILLA Inner Loop Link Adaptation [0130]LTE Long Term Evolution [0131]MCLA Multi Connectivity Link Adaptation [0132]MR-DC Multi Radio Dual Connectivity [0133]NR New Radio [0134]OLLA Outer Loop Link Adaptation [0135]PEP Packet Error Probability [0136]SE Spectra Efficiency [0137]UE User Equipment [0138]PDU Protocol Data Unit

Claims

WE CLAIM: 1. A method, comprising: receiving parameters for rules at a user equipment from a first network node; determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the user equipment; determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg; proposing a block error rate offset to one or more of the first network node and the second network node; determining that the first network node should transmit in the downlink transmission; and informing the first network node that it is recommended to transmit in the downlink transmission.

2. The method according to claim 1, further comprising: performing channel measurements; and receiving a transmission from one or more of the first network node and the second network node respectively using a first modulation and coding scheme and a second modulation and coding scheme according to the block error rate target and the block error rate offset.

3. The method according to claims 1 or 2, wherein determining how the downlink transmission should be taking place comprises determining that the downlink transmission should be taking place from the first network node according to the block error rate target and a first block error rate offset, and from the second network node according to the block error rate target and a second block error rate offset.

4. The method according to any of claims 1-3, further comprising: re-adjusting the block error rate offset after loss of a packet; and indicating to the first network node or the second network node that the block error rate offset has been re-adjusted.

5. A method, comprising: computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment; determining a block error rate offset for each transmission leg; and communicating the block error rate offset to a network node hosting one or more transmission legs.

6. The method according to claim 5, further comprising computing a modulation and coding scheme that satisfies at least one of the block error rate target and a delay target.

7. The method according to claim 6, wherein the modulation and coding scheme is computed by a multi connectivity link adaptation learning phase comprising learning a relationship among a channel quality indicator, the modulation and coding scheme, a delay, and a block error rate, and a multi connectivity link adaptation execution phase wherein each transmission leg decides the modulation and coding scheme used for transmitting a packet based on input comprising the channel quality indicator, the modulation and coding scheme, the delay, and the block error rate.

8. The method according to any of claims 5-7, wherein the relationship is learned with a neural network that models a relationship among the channel quality indicator, the modulation and coding scheme, the delay, and the block error rate

9. The method according to any one of claims 5-8, wherein the block error rate offset is computed by: solving a spectral efficiency maximization problem of the data radio bearer of the user equipment; and determining a difference between an overall block error rate target and a leg error probability.

10. The method according to any of claims 5-9, further comprising updating the modulation and coding scheme until a condition or a combination of conditions is satisfied.

11. The method according to any of claims 5-10, wherein coordinating and configuring the block error rate target comprises: collecting channel quality and experienced block error rate for each transmission leg, wherein the block error rate target is computed based on information collected from each transmission leg; selecting the modulation and coding scheme using the block error rate offset, the block error rate target, and the channel quality indicator; transmitting a protocol data unit to the user equipment using the selected modulation and coding scheme; and transmitting a discard command to the network node when the protocol data unit is correctly received by the user equipment.

12. The method according to any of claims 5-11, further comprising: transmitting a copy of a packet data convergence protocol data unit to a radio link control entity in the network node; and transmitting an original packet data convergence protocol data unit to the radio link control entity of a first transmission leg, and waiting for a transmission outcome, wherein if the transmission of the packet data convergence protocol data unit is acknowledged, the method further comprises indicating to another radio link control entity to discard the packet data convergence protocol data unit, and wherein if the transmission of the packet data convergence protocol data unit is lost, the method further comprises indicating to the another radio link control entity to decrease its block error rate target.

13. An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to receive parameters for rules from a first network node; determine a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the apparatus; determine, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg; propose a block error rate offset to one or more of the first network node and the second network node; determine that the first network node should transmit in the downlink transmission; and inform the first network node that it is recommended to transmit in the downlink transmission.

14. The apparatus according to claim 13, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to: perform channel measurements; and receive a transmission from one or more of the first network node and the second network node respectively using a first modulation and coding scheme and a second modulation and coding scheme according to the block error rate target and the block error rate offset.

15. The apparatus according to claims 13 or 14, wherein how the downlink transmission should occur is determined by determining that the downlink transmission should be taking place from the first network node according to the block error rate target and a first block error rate offset, and from the second network node according to the block error rate target and a second block error rate offset.

16. The apparatus according to any of claims 13-15, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to: re-adjust the block error rate offset after loss of a packet; and indicate to the first network node or the second network node that the block error rate offset has been re-adjusted.

17. An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to compute a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment; determine a block error rate offset for each transmission leg; and communicate the block error rate offset to a network node hosting one or more transmission legs.

18. The apparatus according to claim 17, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to: compute a modulation and coding scheme that satisfies at least one of the block error rate target and a delay target.

19. The apparatus according to claim 18, wherein the modulation and coding scheme is computed by a multi connectivity link adaptation learning phase comprising learning a relationship among a channel quality indicator, the modulation and coding scheme, a delay, and a block error rate, and a multi connectivity link adaptation execution phase wherein each transmission leg decides the MCS used for transmitting a packet based on input comprising the channel quality indicator, the modulation and coding scheme, the delay, and the block error rate.

20. The apparatus according to any of claims 17-19, wherein the relationship is learned with a deep neural network that models a relationship among the channel quality indicator, the modulation and coding scheme, the delay, and the block error rate.

21. The apparatus according to any of claims 17-20, wherein the block error rate offset is computed by: solving a spectral efficiency maximization problem of the data radio bearer of the user equipment; and determining a difference between an overall block error rate target and a leg error probability.

22. The apparatus according to any of claims 17-21, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to: update the modulation and coding scheme until a condition or a combination of conditions is satisfied.

23. The apparatus according to any of claims 17-22, wherein in the coordination and configuration of the block error rate target, the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to: collect channel quality and experienced block error rate for each transmission leg, wherein the block error rate target is computed based on information collected for each transmission leg; select the modulation and coding scheme using the block error rate offset, the block error rate target, and the channel quality indicator; transmit a protocol data unit to the user equipment using the selected modulation and coding scheme; and transmit a discard command to the network node when the protocol data unit is correctly received by the user equipment.

24. The apparatus according to any of claims 17-23, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to: transmit a copy of a packet data convergence protocol data unit to a radio link control entity in the network node; and transmit an original packet data convergence protocol data unit to the radio link control entity of a first transmission leg, and waiting for a transmission outcome, wherein if the transmission of the packet data convergence protocol data unit is acknowledged, the method further comprises indicating to another radio link control entity to discard the packet data convergence protocol data unit, and wherein if the transmission of the packet data convergence protocol data unit is lost, the method further comprises indicating to the another radio link control entity to decrease its block error rate target.

25. An apparatus, comprising: means for receiving parameters for rules from a first network node; means for determining a split of a block error rate target based on the received parameters for each transmission leg, and a block error rate offset for each transmission leg serving a data radio bearer of the apparatus; means for determining, according to the received parameters, how a downlink transmission should be taking place from the first network node and a second network node in each transmission leg; means for proposing a block error rate offset to one or more of the first network node and the second network node; means for determining that the first network node should transmit in the downlink transmission; and means for informing the first network node that it is recommended to transmit in the downlink transmission.

26. An apparatus, comprising: means for computing a split of a block error rate target for each transmission leg serving a data radio bearer of a user equipment; means for determining a block error rate offset for each transmission leg; and means for communicating the block error rate offset to a network node hosting one or more transmission legs.

27. A non-transitory computer readable medium comprising program instructions stored thereon for performing the method according to any of claims 1-16.

28. An apparatus comprising circuitry configured to cause the apparatus to perform a process according to any of claims 1-16.