WO2021194916A1

WO2021194916A1 - Network-based energy efficient uplink data split in dual connectivity

Info

Publication number: WO2021194916A1
Application number: PCT/US2021/023385
Authority: WO
Inventors: Faranaz SABOURI-SICHANI; Daniela Laselva; Jakob Lindbjerg BUTHLER
Original assignee: Nokia Technologies Oy; Nokia Of America Corporation
Priority date: 2020-03-23
Filing date: 2021-03-22
Publication date: 2021-09-30

Abstract

A first uplink transmit power level estimate is determined for a first radio link (RL) from a UE to a first network node, the first uplink transmit power level for transmission in DC of the UE to the first network node over the first RL. A second uplink transmit power level estimate is acquired for a second RL from the UE to a second network nod, the second uplink transmit power level for transmission in DC of the UE to the second network node over the second RL. Uplink radio resource allocations for the first RL are adapted based on the first and second uplink transmit power levels. The second node determines an uplink transmit power level estimate for the second RL and sends this toward the first network node. Uplink radio resource allocations for the second RL are adapted based on at least second uplink transmit power levels.

Description

Network-Based Energy Efficient Uplink Data Split in Dual Connectivity

TECHNICAL FIELD

[0001] This invention relates generally to communications in wireless networks and, more specifically, relates to communications using dual connectivity.

BACKGROUND

[0002] Dual Connectivity (DC) was introduced a while ago to allow a User Equipment (UE) to simultaneously transmit and receive data on multiple component carriers from two cell groups via a Master Node (MN) and Secondary Node (SN). There are multiple different types of DC, but each has an issue with transmit power.

[0003] For instance, the different nodes for the MN and SN may each be at a different distance away from the UE, which means different powers would be used for each. That is, for a node that is closer to the UE, less power should be necessary for transmission than for a node that is farther away from the UE. It would be beneficial to address this.

BRIEF SUMMARY

[0004] This section is intended to include examples and is not intended to be limiting.

[0005] In an exemplary embodiment, a method is disclosed that includes, at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node. The first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link. The method includes acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node. The second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link. The method further includes adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[0006] An additional exemplary embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the computer.

[0007] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform operations comprising: at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link; acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[0008] An exemplary computer program product includes a computer-readable storage medium bearing computer program code embodied therein for use with a computer. The computer program code includes: code for at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link; code for acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and code for adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[0009] In another exemplary embodiment, an apparatus comprises means for performing: at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link; acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[0010] In an exemplary embodiment, a method is disclosed that includes, in a wireless network with first and second network nodes, where a user equipment is in dual connectivity to the first network node over a first radio link and to the second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link. The method includes sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node, and adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

[0011] An additional exemplary embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the computer.

[0012] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform operations comprising: in a wireless network with first and second network nodes, where a user equipment is in dual connectivity to the first network node over a first radio link and to the second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link; sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node; and adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

[0013] An exemplary computer program product includes a computer-readable storage medium bearing computer program code embodied therein for use with a computer. The computer program code includes: code for, in a wireless network with first and second network nodes, where a user equipment is in dual connectivity to the first network node over a first radio link and to the second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link; code for sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node; and code for adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

[0014] In another exemplary embodiment, an apparatus comprises means for performing: in a wireless network with first and second network nodes, where a user equipment is in dual connectivity to the first network node over a first radio link and to the second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link; sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node; and adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the attached Drawing Figures:

[0016] FIG. 1 is a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced;

[0017] FIG. 2 is split into two figures, FIG. 2A and FIG. 2B, and illustrates different architecture deployment options for dual connectivity (e.g., MR-DC), where FIG. 2A illustrates EN-DC and FIG. 2B illustrates NR DC;

[0018] FIG. 3 is an illustration of a GBR configuration and split across MN and SN at SN addition; [0019] FIG. 4 is a table (Table 1) illustrating simulation results of averaged power in units/slot (e.g., units per slot) for some DL and UL examples;

[0020] FIG. 5 is an exemplary schematic illustration of one exemplary embodiment, an implementation option 1 ;

[0021] FIG. 6 is a message sequence chart that is NB-based and illustrates an exemplary embodiment of option 1 ;

[0022] FIG. 7 is an exemplary schematic illustration of one exemplary embodiment, an implementation option 2;

[0023] FIG. 7A is a message sequence chart that is NB-based and illustrates an exemplary embodiment of option 2; and

[0024] FIG. 8 is a flowchart of a method for determining UL grants for one of the MN or SN, in accordance with the illustration of FIG. 7.

DETAILED DESCRIPTION OF THE DRAWINGS

[0025] Abbreviations that may be found in the specification and/or the drawing figures are defined below, at the end of the detailed description section.

[0026] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this Detailed Description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims.

[0027] The exemplary embodiments herein describe techniques for network-based energy efficient uplink data split in dual connectivity. Additional description of these techniques is presented after a system into which the exemplary embodiments may be used is described.

[0028] Turning to FIG. 1, this figure shows a block diagram of one possible and nonlimiting exemplary system in which the exemplary embodiments may be practiced. A user equipment (UE) 110, radio access network (RAN) nodes 170 and 170-1, and network element(s) 190 are illustrated. In FIG. 1, a user equipment (UE) 110 is in wireless communication with a wireless network 100. A UE is a wireless, typically mobile device that can access a wireless network. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a control module 140, comprising one of or both parts 140-1 and/or 140-2, which may be implemented in a number of ways. The control module 140 may be implemented in hardware as control module 140-1, such as being implemented as part of the one or more processors 120. The control module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module 140 may be implemented as control module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111, and with RAN node 170-1 via a wireless link 111-1.

[0029] Each RAN node 170, 170-1 is a base station that provides access by wireless devices such as the UE 110 to the wireless network 100. The RAN nodes 170 may be a Master Node (MN) (illustrated as reference 170) and the RAN node 170-1 may be a Secondary Node (SN). These nodes may be referred to herein as eNBs or gNBs. Additional embodiments are also possible, as described below. The two RAN nodes 170, 170-1 are assumed to be similar, and therefore only a possible internal configuration of RAN node 170 is described.

[0030] The RAN node 170 may be, for instance, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or an ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to a 5GC (e.g., the network element(s) 190). The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node hosting RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the FI interface connected with the gNB-DU. The FI interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU. One gNB-CU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the FI interface 198 connected with the gNB- CU. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of an RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station.

[0031] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N/W I/F(s)) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory/memories and processor(s), and/or other hardware, but these are not shown.

[0032] The RAN node 170 includes a control module 150, comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The control module 150 may be implemented in hardware as control module 150-1, such as being implemented as part of the one or more processors 152. The control module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module 150 may be implemented as control module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the control module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

[0033] The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more RAN nodes 170, 170-1 communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, e.g., an Xn interface for 5G, an X2 interface for LTE, or other suitable interface for other standards.

[0034] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH/DU, and the one or more buses 157 could be implemented in part as, e.g., fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU) of the RAN node 170 to the RRH/DU 195. Reference 198 also indicates those suitable network link(s).

[0035] It is noted that description herein indicates that “cells” perform functions, but it should be clear that the base station that forms the cell will perform the functions. The cell makes up part of a base station. That is, there can be multiple cells per base station. For instance, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360 degree area so that the single base station’s coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a base station may use multiple carriers. So if there are three 120 degree cells per carrier and two carriers, then the base station has a total of 6 cells.

[0036] The wireless network 100 may include a network element or elements 190 that may include core network functionality, and which provides connectivity via a link or links 181 with a further network, such as a telephone network and/or a data communications network (e.g., the Internet). Such core network functionality for 5G may include access and mobility management function(s) (AMF(s)) and/or user plane functions (UPF(s)) and/or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (Mobility Management Entity)/SGW (Serving Gateway) functionality. These are merely exemplary functions that may be supported by the network element(s) 190, and note that both 5G and LTE functions might be supported. The RAN node 170 is coupled via a link 131 to a network element 190. The link 131 may be implemented as, e.g., anNG interface for 5G, or an SI interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N/W I/F(s)) 180, interconnected through one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0037] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171, and also such virtualized entities create technical effects.

[0038] The computer readable memories 125, 155, and 171 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples. The processors 120,

152, and 175 may be means for performing functions, such as controlling the UE 110, RAN node 170, and other functions as described herein.

[0039] In general, the various embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, vehicles with a modem device for wireless V2X (vehicle-to- everything) communication, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances (including Internet of Things, IoT, devices) permitting wireless Internet access and possibly browsing, IoT devices with sensors and/or actuators for automation applications with wireless communication tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions.

[0040] Having thus introduced one suitable but non-limiting technical context for the practice of the exemplary embodiments of this invention, the exemplary embodiments will now be described with greater specificity.

[0041] Exemplary embodiments are made, in one context, for 5G communication systems, and particularly for 5G as this relates to the study item RP-181463, “Study on UE Power Saving in NR”, June 2018. RAN2#106 completed the UE power saving study in May 2019, where the study focused on power saving deployment for a single NR connection. However, RAN2 agreed that power saving improvements in EN-DC (i.e., one type of dual connectivity configuration) would be viable to consider during the work item phase (see RP- 191137, 3GPP TSG RAN meeting #84, Newport Beach, USA, June 3rd - 6th , 2019). Also, the following recommendation is added to the 3GPP Technical Report (TR) 38.840 (see 3GPP TR 38.840 V16.0.0 (2019-06)), “Study on UE Power Saving (Release 16)”: “Methods for reducing power consumption in DC configuration (EN-DC in particular) should also be supported.”

[0042] Regarding UE Power saving, as part of the study in RP-181463, it was suggested that the UE can utilize different power saving schemes as specified in 3 GPP TR 38.840 whenever the conditions allow. In general, the UE power consumption reduction will utilize a wide range of techniques to allow UE implementations which can operate with reduced power consumption. The proposed schemes which are very likely to be introduced in 3 GPP release 16 are listed below. The list is based on the status of the study item at the date this document is generated.

[0043] 1) UE adaptation to the traffic and power consumption characteristic.

[0044] 2) UE assistance for power saving.

[0045] 3) Power saving signal/channel/procedure for triggering adaptation to UE power consumption.

[0046] 4) Power consumption reduction in RRM measurements.

[0047] The agreed power saving schemes focus on control plane communication between the UE and NB (e.g., gNB or eNB) while the data plane is kept out of the discussion. That is, the study item did not address power saving for the data plane, which is also important for dual connectivity.

[0048] With respect to Dual Connectivity (DC), a number of 5G architecture deployment options are defined in 3 GPP for independent migration of the access and core networks. The exemplary embodiments herein will be applicable for any dual connectivity deployment option, however, the examples with details in this document are based on, e.g., option 3, MR-DC with EPC (EN-DC), and the NR-NR Dual connectivity (NR DC) among MR- DC options with NGC as shown in FIG. 2.

[0049] FIG. 2 is split into two figures, FIG. 2A and FIG. 2B, and illustrates different architecture deployment options for dual connectivity (e.g., MR-DC), where FIG. 2A illustrates EN-DC and FIG. 2B illustrates NR DC. In the example of FIG. 2A, there is an Evolved Packet Core (EPC) 210-1, which includes an MME 190-1 and a S-GW 190-2. The UE 110 connects to the MN 170, which is an eNB (e.g., LTE base station), and the SN 170-1, which is a gNB (e.g., 5G base station). The user planes (UPs) are illustrated by solid lines and the control planes (CPs) by dashed lines. The following control planes are shown: Sl-C between the MN 170 and the EPC 210-1; the control interface, X2-C, between the MN 170 and the SN 170-1; and a CP between the MN 170 and the UE 110. The following user planes are illustrated: Sl-U between the EPC 210-1 and the SN 170-1; the X2-U between the MN 170 and the SN 170-1; and two UPs between the UE 110 and the MN 170 and SN 170-1. [0050] In the example of FIG. 2B, there is a Next Generation Core (NGC) (also called a 5G Core, 5GC) 210-2, which includes an AMF 190-1 and a UPF 190-2. The UE 110 connects to the MN 170 and SN 170-1, both of which are gNBs. The following control planes are shown: NG-C between the MN 170 and the NGC 210-2; the XN-C between the MN 170 and the SN 170-1; and a CP between the MN 170 and the UE 110. The following user planes are illustrated: NG-U between the EPC 210-2 and the MN 170 and SN 170-1; the XN-U between the MN 170 and the Sn 170-1; and two UPs between the UE 110 and the MN 170 and SN 170-1.

[0051] In dual connectivity (DC), such as Multi-RAT Dual Connectivity (MR-DC), in addition to the RRC connection towards the MN, a mobile device (e.g., UE 110) has a second Radio Resource Control (RRC) termination at the secondary node (SN). From the UE perspective, two cell groups are visible, i.e., the Master and Secondary Cell Groups (MCG and SCG) and each cell group contains a primary cell called PCell (MCG) and PSCell (SCG) as in the legacy DC framework.

[0052] In DC, the Master Node (MN), belonging to the MCG and Secondary Node (SN), belonging to the SCG, operate as independently as possible. Basically, each gNB (or eNB) owns its radio resources and is primarily responsible for allocating radio resources to the UE independently. However, the MN is responsible for maintaining the RRC connection state transitions, handling the connection setup/release, and initiating the first-time secondary node addition; i.e. the DC setup. Any information exchange / coordination between MN and SN takes place via the X2 (FIG. 2A) or Xn (FIG. 2B) interface.

[0053] Also in DC, the network achieves per-user throughput increase by aggregating radio resources from two NBs (e.g., gNB or eNB). In the uplink, the UE uses only one of the two links for PDCP PDU transmission as long there is no need for a large data amount. Note switching between MN and SN for uplink data requires layer 3 messaging (i.e., RRCConnectionReconflguration). It is up to the master NB to decide whether to utilize both UL legs and how to split data of a split Data Radio Bearer (DRB) across the two RLC entities.

[0054] Basically, how to perform data transmission on the split DRBs is decided by the MN based on its implementation and related commands are provided to the UE by RRC parameters, e.g., carrying PDCP configuration. These include two main parameters in exemplary embodiments: [0055] 1) As long as the UL data buffer size is below a given limit (defined by the parameter ul-DataSplitThreshold), the UL transmission will use only one RLC entity (i.e., one transmission path). Namely, this is the RLC entity that is configured as the primary path by the network. Any RLC entities configured either at the MN or SN could be defined as primary (see 3GPP TS 36.331 version 15.8.0 and 38.331 version 15.8.0).

[0056] 2) An RLC entity associated with the SN can be (re-)configured as a primary path using, e.g., the parameter ul-DataSplitDRB-ViaSCG through RRC signaling (see 3GPP TS 36.331). That is, the SN may be reconfigured such that the SN is used as the primary leg for UL data as long as the size is below the limit that requires use of both legs. This does not mean SN is changed to be MN but instead is used as a primary leg for UL.

[0057] Otherwise, if the UE’s UL data buffer size (e.g., PDCP and RLC buffers) exceeds the threshold ul-DataSplitThreshold, the data should be split between the two nodes (see 3GPP TS 36.331 and 38.331). More than one RLC entity may be configured (and activated) per node to split the data.

[0058] The UE will then - depending on its data buffer size - transmit on MCG,

SCG, or apply split bearer based on the rules below (see Section 5.2, 3GPP TS 38.323 version 15.5.0):

[0059] “When submitting a PDCP (data) PDU to lower layer, the transmitting PDCP entity shall:

[0060] - if the transmitting PDCP entity is associated with one RLC entity:

[0061] o submit the PDCP PDU to the associated RLC entity;

[0062] - else, if the transmitting PDCP entity is associated with two RLC entities:

[0063] o if the PDCP duplication is activated:

[0064] ■ if the PDCP PDU is a PDCP Data PDU:

[0065] - duplicate the PDCP Data PDU and submit the PDCP Data

PDU to both associated RLC entities;

[0066]

else

[0067] submit the PDCP Control PDU to the primary RLC entity;

[0068] o else [0069]

if the two associated RLC entities belong to the different

Cell Groups; and

[0070] ■ if the total amount of PDCP data volume and RLC data volume pending for initial transmission (as specified in TS 38.322 version 15.5.0) in the two associated RLC entities is equal to or larger than ul-DataSplitThreshold:

[0071] - submit the PDCP PDU to either the primary RLC entity or the secondary RLC entity;

[0072] ■ else (less than threshold => one link):

[0073] - submit the PDCP PDU to the primary RLC entity.”

[0074] In particular, see the rules starting with “if the total amount of PDCP data volume...” and ending at “submit the PDCP PDU to the primary RLC entity”.

[0075] The choice of primary and secondary RLC entity as well as the data split ratio is based on the MN decision and is up to NW implementation (e.g., implementation by the MN). At SN addition preparation, the MN may ask the SN to provide additional resources to the UE. To guide the resource assignments at SN, the MN splits the total Guaranteed Bit Rate (GBR) target of the split DRB in two portions and asks SN to provide one portion of the GBR that the MN cannot provide by itself as illustrated in FIG. 3. FIG. 3 is an illustration of a GBR configuration and split across MN and SN at SN addition.

[0076] In FIG. 3, there is a MN 170 of an eNB/gNB (with a GBRMN) and an SN 170- 1 of a gNB (with a GBRSN). In block 310, the GBRMN and GBRSN are decided by MN delegating some load to the SN 170-1. In reference 320, there is a DC SN addition request from the MN 170 to the SN 170-1, including an indication of GRBSN.

[0077] The GBR split is typically based on MN’s Physical Radio Block (PRB) load. The consequent GBR distribution between MN and SN is used for determining UL grants by the MN and SN.

[0078] One aim of UL data bearer split is to increase the UL throughput for the user, as the split enables the UE to utilize radio resources from two RAN nodes 170, 170-1 (e.g., gNB and/or eNB). The split also provides better user experience in cases where one node (cell group, CG) link is (e.g., temporarily) overloaded, through network load balancing. Similarly, the split improves the UE’s QoS when the link towards one node may become degraded. In current procedures, the master node (MN) calculates a target data split ratio between MN and SN, based on the following:

[0079] a) the radio conditions of its own link and/or the secondary links, and

[0080] b) the network load in Master CG (MCG) and Secondary CG (SCG).

[0081] At the initial SN addition, the MN splits the total GBR target associated to an

UL split DRB, and therefore into GBRMN and GBRSN, requesting the SN to help contribute according to its dedicated GBR target. Such GBR split at MN will be based, e.g., on the MN’s Physical Radio Bearer (PRB) load, indicating a desired data split ratio. After the DC setup is completed, each node can then determine the UL grants based on the requested GBR target per node, and the buffer status reporting (BSR) received by the UE. Hence, the MN and SN should be able to ensure indirectly that the UE uses a desired data split ratio, by sending appropriate UL scheduling grants to the UE.

[0082] It is noted that two radio links towards the MN and SN have their independent power control running. That is, the UL transmit power level of each link, which is, e.g., directly proportional to the pathloss between the UE and the corresponding node, is controlled by the NW, separately within each node. This may be realized through legacy uplink power control mechanisms. For instance, an open-loop power control scheme is typically used for controlling, e.g., the transmit power over PUSCH, based on network configured parameters such as Po and a, which are then combined with the UE-estimated path loss. These parameters are configured by the NW and used by UE to calculate open loop transmit power. Refer to 3 GPP TS 38.213, section 7. In addition, the network can fine-tune the UE transmit by transmit power control (TPC) commands.

[0083] Although the power control algorithm at each node independently ensures that the uplink transmit powers used for transmissions towards each node are adequate, no explicit consideration of the uplink transmit power is taken when making the data splitting decision in conventional techniques.

[0084] However, the dominating power consumption factor at the UE is due to uplink transmissions because of the significant high current consumption required by the power amplifiers. Table 1 (see FIG. 4) quantifies in detail the impact of UE power consumption during UL transmission as function of the UL transmit power. Particularly, the table contains examples showing how the average consumed power by the UE depends on the uplink transmit power of the used link. The examples are generated using the NR UE power consumption model as defined in 3 GPP (3 GPP TR 38.840). The model applies TDD, 30 kHz SCS and 100 MHz BW. It can be observed that using a 23 dBm link instead of a 0 dBm link increases the average power consumption per slot by 200 % using a single UL component carrier and single antenna and an increase of 157 % with a single UL component carrier and two antennas (2x2 UL MIMO).

[0085] The UL transmit power required by a UE may be higher towards the MN than SN (or vice versa) depending on the UE’s radio link condition, mainly, the path loss of the selected radio link (e.g., beam) as function of the distance between the UE and each node. This difference can be up to several dBs in deployments, where, for example, a UE in EN-DC mode connects to a macro LTE eNB and an NR small cell, and the UE may be in proximity of the NR small cell. Based on what is shown in FIG. 4, the power consumption for UL transmissions is directly proportional to the absolute UL transmit power, and the UL transmit power is directly proportional to the path loss. Thus, when the UE has significantly different distances to two nodes, then the corresponding path loss and UL transmit power, and, hence the associated power consumption, can differ by several dBs across the two nodes. The inventors remark that the difference in transmit power between two nodes may also be due to different operating carrier frequencies.

[0086] Therefore, when deciding the primary RLC entity to UL transmissions and/or the relative data split across MN and SN, it would be beneficial to consider the requested transmit power level toward each node in order to improve UE power saving. This is not being done, however.

[0087] For instance, Rel-13 LTE supports uplink bearer split, building on top of the downlink split-bearer architecture with aggregation of data links at PDCP layer, allowing utilization of uplink radio resources on both MCG and SCG links simultaneously for a data bearer. The same framework was inherited by NR. Currently, the distribution of UL data bearers’ split over MCG and SCG is up to network implementation and can be based on the Buffer Status Report (BSR) and configured Guaranteed Bit Rate (GBR) at each node using the following standard features.

[0088] Consider a split DRB (DC uplink, data plane) in the following. [0089] 1) A buffer size-based threshold is used to trigger the use of secondary leg, and configuration of the primary leg for data plane is according to the following:

[0090] a) ul-DataSplitThreshold [see 3GPP TS 36.331 and 38.331], which indicates the threshold value for uplink data split operation specified in 3GPP TS 36.323 version 15.5.0. Value blOO means 100 Bytes, b200 means 200 Bytes and so on. E-UTRAN only configures this field for split DRBs.

[0091] b) ul-DataSplitDRB - ViaS CG [see 3 GPP TS 36.331], which indicates whether the UE shall send PDCP PDUs via SCG as specified in 3 GPP TS 36.323. E-UTRAN only configures the field (i.e. indicates value TRUE) for split DRBs. For PDCP duplication, if this field is set to TRUE, the primary RLC entity is SCG RLC entity and the secondary RLC entity is MCG RLC entity. If this field is not configured or set to FALSE, the primary RLC entity is MCG RLC entity and the secondary RLC entity is SCG RLC entity.

[0092] 2) The BSR is sent from the UE to the gNB/eNB to indicate the amount of pending data in the uplink buffer. When the UE is configured with an UL split DRB, two MAC entities are configured to the UE: one for the MCG and one for the SCG, and the data available for transmission of a split bearer will be equally reflected in the two equal BSRs, which are sent towards the MCG and SCG to the corresponding MAC entity, if BSR > ul-DataSplitThreshold. Otherwise, the BSR will be sent to the primary link.

[0093] The inventors remark that currently the primary link and when the data should be split are controlled by the network in a semi-static fashion, such that the relevant parameters are provided via RRC signaling. The exemplary embodiments herein build upon both concepts and extend them, making the data splitting based on power-efficiency and allowing a quick change of the primary leg based on power-efficiency considerations.

[0094] As additional information about DC, in the RP-182076 WID on multi-RAT DC and CA enhancements, they stated the following: “In addition to DC, multiple carriers have been a key feature for boosting peak data rates in flexible manner for many different deployment scenarios. However, the CA framework is based on tight network coordination and availability of UE assistance information via UE measurement reporting. The operation relies on network configuring and deciding whether to keep the SCell activated (for maximum peak data rate) or deactivated (for minimized power consumption while maintaining CA).” No scope is related to a power-saving based split. Further, although this WID has an objective for “early measurement reporting” to reduce the MR-DC setup time with minimized UE power consumption impact, this is not relevant in the context of the exemplary embodiments herein.

[0095] To address these and other issues, a UE power saving optimization is provided in exemplary embodiments in MR-DC use cases by considering the UL transmit power over each radio link in the decision of the uplink data distribution between two nodes. This is achieved by adapting the UL radio resource allocations to the UE from each node based on the UL transmit power to MN and to SN based on network mechanisms.

[0096] Broadly speaking, the exemplary embodiments allow the UL data of an UL split DRB to be transmitted primarily over the most power efficient uplink radio link, i.e., the link with lowest requested UL transmit power. However, the scheme still lets the less power- efficient radio link to contribute to the data delivery in order to address high required throughput demand and reduce the total time for completing the transmissions such that the UE can move more quickly to a sleep state and save power.

[0097] Two main network-based implementation options are proposed, involving both nodes, and the master node only, respectively. The main features of both options are introduced immediately below, and further details are elaborated below after this introduction. It is remarked that both options may have standard impact, e.g., new X2/Xn signaling.

[0098] Concerning option 1, the following exemplary operations may be performed. This option involves both the MN 170 and SN 170-1.

[0099] When receiving a legacy (e.g., total) BSR from the UE that exceeds the data splitting threshold, e.g., ul-DataSplitThreshold, each node will allocate the UL radio resources to the UE based on an estimated power-efficient BSR split ratio in addition to other local information such as PRB load, GBR, and the like. Each node determines the power-efficient BSR split ratio by scaling the received total BSR based on the estimated UL transmit power to be required by the UE towards both nodes.

[00100] For calculating such power-efficient BSR split ratio, each node estimates the absolute UE UL transmit power level for its own link (e.g., based on existing UE reports and/or new dedicated UE report(s)) and acquires the estimated absolute UL transmit power level for the other link over Xn/X2. The estimated UL transmit power towards the node(s) are continuously updated/maintained by the nodes, and when the changes seem significant (e.g., as per a threshold), the ratio will be updated. This procedure could be based on events such as the Ax events in 3GPP TS 36.331. Furthermore, for each BSR reported by the UE, the nodes may recalculate the UL transmit power.

[00101] With respect to option 2, this option is controlled by the MN 170. In this option, initially at DC setup, the master node determines the GBR split across MN and SN (i.e., GBRMN and GBRSN) for the DRB based on an estimated power-efficient data split ratio (in addition to other local information such as PRB load, and the like), and requests the estimated GBRSN from the SN. Then, the MN may (re)evaluate GBRSN dynamically and request a different GBRSN from the SN in case the value of GBRSN has changed compared to the previous request. The re-evaluation may be triggered when it is expected that the UE’s UL transmit power to at least one node is changing, e.g., based on factors such as UE mobility (e.g., change of RSRP values reported by the UE), UL transmit power measures (e.g., PHR values reported by the UE), interference level (e.g., reported RSRQ/SINR), and the like. When receiving a legacy (e.g., total) BSR from the UE that exceeds the data splitting threshold, e.g., ul-DataSplitThreshold, each node determines power-efficient UL resource allocation based at least on its own GBR split value, GBRMN and GBRSN·

[00102] Now that an introduction has been provided, additional details are provided. As previously described an exemplary proposal includes that the data split of an uplink DRB between MN and SN is based on the current level/estimate of UL transmit power PUL,MN and PuL.SN. This way, the total uplink transmit power can be minimized, the total transmission time can be reduced, and power saving achieved.

[00103] Although the NBs 170, 170-1 control the UE’s transmit power via, e.g., transmit power control commands (TPCs), they have limited information about the UE’s absolute uplink transmit power level. However, each NB can utilize, e.g., the UE’s power headroom (PHR) report to evaluate whether the UE is close to its maximum transmit power capability and/or utilize measures indicative of the UE’s Path Loss (PL) (e.g., RSRP) as another indication to get knowledge about the UE’s absolute UL transmit power. Alternatively or additionally, the UE can add the absolute transmit power to its report. [00104] Furthermore, after the DC setup is completed, the UE will adjust independently the transmit power for the two radio links towards MN and SN respectively, using independent power control algorithms based on the TPC commands. At the network side, each node may have information of UE’s UL transmit power toward the own link, as described above, but has very limited information about the UE’s UL transmit power toward the other link. Hence, both implementation options proposed herein suggest to exchange or forward information indicative of the UE’s UL transmit power toward one link of a node with the other node, depending on the implementation as explained further below.

[00105] With respect to a NW-based implementation of option 1 (described in brief above), in this implementation, each node will get the information about the other node’s required UL transmit power and can calculate its own “node-specific” BSR value. As is known, the BSR has a value, being a number indicated by 5 or 8 bits as an example. More specifically, the BSR is an index per Logical Channel Group having 5/8 bits, which is mapped to an amount of data in bytes according to tables defined in the specifications, e.g. Table 6.1.3.1-1 and FIG. 6.1.3.1-2 of 3GPP TS 38.321, version 15.8.0.

[00106] The UL transmit power information update may be triggered when it is expected that the UE’s UL transmit power to each node will change, e.g., based on factors such as UE mobility (e.g., change of RSRP values reported by the UE), UL transmit power measures (e.g., PHR values reported by the UE), interference level (e.g., reported RSRQ/SINR), and the like. Furthermore, the update may be sent to the other node when the changes are evaluated to be significant (e.g., when the PHR change exceed predefined x dB). The “node-specific” BSR values scale BSR_totai with the optimal total UL transmit power, i.e., in accordance to the relative UL transmit powers, as shown below in the non-limiting example of a pseudo-algorithm for energy-efficient BSR calculation:

[00107] 1) BSRtotai = BSRMN + BSRSN;

[00108] 2) BSRMN / BSRSN = PUL.SN / PUL,MN;

[00109] 3) BSRMN = Ceil (PUL.SN / (PUL,MN + PUL.SN) * BSRtotai); and

[00110] 4) BSRSN = BSRtotai - BSRMN.

[00111] Ceil (·) is a ceiling function. Equation (1) illustrates an expectation that the total BSR is split to BSR-node(s). Equation (2) is an illustration of an exemplary embodiment, i.e., the BSR should be split as reverse proportional to the UL transmit power. Substituting BSR_SN in Eq. (1) using Eq. (2), one can reach Equation 3. It should be noted that these equations show only a potential exemplary algorithm. Additionally, variants with or without ceiling or using other functions than ceiling (e.g., floor) could be used instead.

[00112] Each node will then allocate resources according to the calculated power- efficient BSR and provide UL grants to the UE. For instance, consider the MN. The MN calculates its own PUL.MN and, as described below, receives PUL,SN from the SN and BSRtotai from the UE. This means using equation (3), the MN can calculate its own BSRMN. Consider the SN. The SN calculates its own PUL.SN and, as described below, receives PUL,MN from the MN and BSR_totai from the UE. This means using equation (3), the SN can calculate BSRMN. Once this is calculated, the SN can determine its own BSRSN using, e.g., equation (4).

[00113] It should be noted that in the NW-based implementation the calculated nodespecific BSR may exceed the NW resources available for this UE/DRB, hence, the node may allocate the maximum amount of UL data resources and inform the other node about the remaining part. The receiving node may then provide such remaining part if possible.

[00114] A schematic diagram illustrating this implementation is shown in FIG. 5 and a message sequence chart showing the details of this implementation is shown in FIG. 6. FIGS. 5 and 6 illustrate the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. The operations described below would be performed by UE 110, under control of the control module 140, or by one of the RAN nodes 170 or 170-1, under control of a corresponding control module 150.

[00115] Turning to FIG. 5, this figure is an exemplary schematic illustration of one exemplary embodiment of an implementation of option 1. In block 510, the GBRSN is requested by the MN 170 at the SN 170-1, e.g., via a PDU Session Resource Setup Info IE at the addition (set up) of the SN and may be modified later on via, e.g., a PDU Session Resource Modification Info IE in a SN Modification Request procedure over the X2/Xn interface. It is noted that in option 1, primary emphasis is placed on the estimated power-efficient BSR split ratio to allocate UL radio resources to the UE. Other factors may also be used, such as GBR for each node. Techniques for using GBR are presented below, e.g., with respect to FIGS. 7 and 8.

[00116] In signaling 540, the MN and SN exchange PUL,MN and PUL.SN over an X2 or Xn interface, using powers determined in blocks described below. In block 530, the MN gets or calculates its own PUL (PUL,MN), and receives the SN’s PUL (PUL,SN). Reference 550 indicates the UE 110 sends a BSR_totai and UL transmit power report(s) to the MN 170. The MN 170 determines its own BSRMN according to the above BSR calculation.

[00117] In block 520, the SN 170-1 gets or calculates its own PUL (PUL.SN), and receives the MN’s PUL (PUL,MN). Reference 560 indicates the UE 110 sends a BSRtotai and UL transmit power report(s) to the SN 170-1. The SN 170-1 determines its own BSRSN according to the above BSR calculation.

[00118] FIG. 5 illustrates certain operations in terms of a network structure, without regard for sequence of operations. Meanwhile, FIG. 6 is a message sequence chart that is NB- based and illustrates an exemplary embodiment of option 1. FIG. 6 consequently illustrates one possible sequence of operations.

[00119] In signaling 603, there is a secondary node addition procedure (e.g., block 510 of FIG. 5) including the GBR distributions, GBRMN and GBRSN. Reference 605 indicates that the UE receives UL data to be transmitted. In block 610, in response to the BSRtotai being greater than (>) ul-DataSplitThreshold, the UE starts an UL transmission procedure to both nodes. In block 615, the MN 170 calculates an UL transmit power at the UE, PUL.MN, based on, e.g., PHR, PL, and/or a direct report from the UE. In block 620, the SN 170-1 calculates an UL transmit power at the UE, PUL.SN, based on, e.g., PHR, PL, and/or a direct report from the UE. Signaling 625 indicates that the two powers, PUL,MN and PUL.SN are exchanged. These steps correspond to part of blocks 520, 530 and also to signaling 540 of FIG. 5.

[00120] Reference 630 indicates that reevaluation of GBR may be triggered based on estimated changes in UL transmit power. In this option (option 1), each node calculates new value of the amount of UL data the node should accommodate based on the received BSR-node together with the total BSR. In the second option (option 2), described below, the MN recalculates the GBR split and modifies the split. [00121] Reference 640 is a scheduling request from the UE 110 to the MN 170. The MN 170 responds in signaling 645 with DCI with an UL grant. The UE 110 responds in signaling 650 with UCI with an indication of BSR_totai. Similar signaling is performed by the UE and SN: Reference 655 is a scheduling request from the UE 110 to the SN 170-1; the SN 170-1 responds in signaling 660 with UCI with an UL grant; and the UE 110 responds in signaling 665 with DCI with an indication of BSRtotai.

[00122] In block 670, the MN 170 calculates BSR_MN and allocates UL data accordingly. This corresponds to part of block 530 in FIG. 5. In block 675, the SN 170-1 calculates BSR_SN and allocates UL data accordingly. This corresponds to part of block 520 in FIG. 5.

[00123] Responsive to block 670, the MN 170 sends DCI with UL grant(s) in signaling 680, and the UE responds with a PUSCH transmission in signaling 690. Similarly, responsive to block 675, the SN 170-1 sends DCI with UL grant(s) in signaling 685, and the UE responds with a PUSCH transmission in signaling 695. For blocks 670 and 675, this allocation is expected to be a network-specific implementation, and may use, e.g., any of the techniques described herein.

[00124] For the NW-based implementation of option 2, an alternative embodiment is to let the Master Node 170 split GBR between MN and SN based on the UE’s UL transmit power over MCG and SCG legs to achieve a power efficient data splitting. In this example, the MN 170 needs to retrieve the transmit power level indicator(s) from the SN 170-1 over the X2/Xn interface for evaluation and decision of the most power efficient UL data split.

[00125] A schematic diagram illustrating this implementation is shown in FIG. 7 and a message sequence chart showing the details of this implementation is shown in FIG. 7 A. FIGS.

7 and 7A illustrate the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. The operations described below would be performed by UE 110, under control of the control module 140, or by one of the RAN nodes 170 or 170-1, under control of a corresponding control module 150. [00126] In further detail, the UL transmit power is independent of the GBR and is mainly based on the path loss and power control parameters configured by NW. So, the distribution of the UL transmit power depends on the UE’s physical channel toward each gNB. This distribution will not be changed by the techniques herein. The GBR, however, is now being changed, e.g., in FIG. 7 described below, relative to the UL transmit power, so the node (MN or SN) that has the least UL transmit power (relative to the UL transmit power for the other node) should provide more UL resources to the UE. That is, the UE will transmit the largest portion of its data using the link which needs less UL transmit power. Consequently, UL transmit power factors into the new GBR distribution.

[00127] The MN can make a decision on the most power efficient link by comparing SN information with its own. The decision can then be used to update the UL data split across MN and SN. A schematic diagram illustrating this implementation is shown in FIG. 7. FIG. 7 is an exemplary schematic illustration of one exemplary embodiment, an implementation option 2. FIG. 7 illustrates the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. The operations described below would be performed by UE 110, under control of the control module 140, or by one of the RAN nodes 170/170-1, under control of a corresponding control module 150.

[00128] In block 710, the GBRSN is configured by the MN 170 at the SN 170-1, e.g., in response to addition of the SN and can be reconfigured at SN modification considering UE UL transmit power. Reference 560 indicates the UE 110 sends the BSR_totai and UL transmit power report(s) to the SN 170-1. In block 720, the SN 170-1 gets or calculates its own PUL (PUL,SN), and forwards this power to the MN in signaling 740 over the X2 or Xn interface. In block 730, the MN gets or calculates its own PUL (PUL,MN), and receives the SN’s PUL (PUL,SN). Reference 550 indicates the UE 110 sends a BSR_to_tai and UL transmit power report(s) to the MN 170. The MN (see block 730) determines a new GBR split between GBRMN and GBRSN. That is, the MN determines a new split with new GBR for itself and SN, and the MN uses the GBR to control the split. The SN provides its UL transmit power to MN for MN’s recalculation and then applies the new GBR value the SN receives to provide UL resources (as performed in a legacy system). The GBRSN is used by the SN to scale the total requested BSR from the UE to the portion the SN needs to accommodate.

[00129] The re-evaluation (as in block 730) may be triggered when it is expected that the UE’s UL transmit power to each node will change, e.g., based on factors such as UE mobility (e.g., change of RSRP values reported by the UE), UL transmit power measures (e.g., PHR values reported by the UE), interference level (e.g., reported RSRQ/SINR), and the like.

[00130] Turning to FIG. 7A, this figure is a message sequence chart that is NB-based and illustrates an exemplary embodiment of option 2. The first operations 603, 605, 610, 615, and 620 are the same as what occurred in FIG. 6. In signaling 725, the SN 170-1 sends information indicative PUL.SN to the MN 170. In block 730, the MN 170 determines a new GBR split based on the ratio of PUL,MN and PIJL.SN· In block 735, the MN 170 and SN 170-1 perform a secondary node modification procedure including a new GBR distribution, GMBMN and GBRSN.

[00131] Signaling 640 to 665 are the same as in FIG. 6. In block 770, each of the MN and SN nodes provides UL resource grants according to the new GBR split. Block 770 is described in additional detail in reference to FIG. 8.

[00132] Turning to FIG. 8, this figure is a flowchart of a method for determining UL grants for one of the MN or SN, in accordance with the illustration of FIG. 7. FIG. 8 illustrates the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. These blocks would be performed by one of the MN 170 or SN 170-1, e.g., under control of a corresponding control module 150.

[00133] In block 810, the node determines (the MN) or receives (the SN) a GBR_node, where GBR_node is the GBR for that corresponding node (i.e., GRBMN for the MN or GBRSN for the SN). In block 820, the node receives the total BSR (BSRtotai) from the UE.

[00134] As stated previously, the GBR does not directly affect the UL transmit power. The UL transmit power is dependent on the path loss between the UE and NW and on how much UL resources (e.g., Physical Resource Blocks, PRBs) are assigned in the UL grant that each node should provide to the UE for its transmission of data. The number of assigned PRBs per node would be determined based on the GBR split in option 2. In legacy systems, the requested GBR at a node influences how much of the requested BSR would be granted from a node (e.g., how much from MN itself and how much should be provided by SN). In option 2 herein, by contrast, it is proposed to change the partitioning of the GBR per node and in turn the partitioning of the UL grants / PRBs depending on the UL transmit power.

[00135] To this end, how to provide (see block 830) the UL grants that can accommodate an amount of data according to a portion of GBR assigned to the node and based on the requested BSR should be explained. A number of options may be considered. In a first option (shown as option A in FIG. 8 to distinguish from the options 1 and 2 previously presented), each node should provide (see block 840) UL grants (e.g., in terms of corresponding bits that the node can accommodate, TBS (transport block size) to comply with the value of GBRnode (e.g., in bit/rate). Each node may determine the compliance with the corresponding GBRno_de by comparing the total transport block sizes allocated in a time window (allocated bit rate) against the GBRnode, where the time window may depend on the application and its QoS parameters (e.g. latency targets). For instance, packet scheduling priorities that determine the scheduling of the corresponding data in the next scheduling intervals, can be adjusted based on such comparison. As an example, this may result in decreasing the priority when the allocated bit rate is compliant (e.g. meeting or exceeding) the GBRnode.

[00136] In a second option (option B), a node can scale the total BSR based on the assigned GBRnode (block 850) and provide (block 860) UL grants that can accommodate an amount of data (e.g., in terms of bits) according to the scaled total BSR. One possible scaling is illustrated by block 880, which if performed by linearly scaling the total BSR with the ratio GBRno_de/ total GBR. The total GBR is known at the MN but may not be known at the SN. So, this second option may be implemented only by the MN, unless MN also provides (see block 890) to SN the total GBR in addition to GBRSN.

[00137] In other words, when a node receives the total BSR from the UE, the node might scale the total BSR based on its assigned GBR value, and provide an UL grant that can accommodate an amount of data according to the scaled BSR. This is one exemplary option of how a node should scale the total BSR based on its own GBR. Others include a linear scaling with the GBR_node or a linear scaling with the ratio GBRjnode/totalGBR. [00138] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect and advantage of one or more of the example embodiments disclosed herein is that the data split across two nodes can be performed accounting for UE power consumption, allowing to use mostly the link requiring the lowest UL transmit power, and thus leading to the lowest UE power consumption. The impact on power consumption is described above. An additional technical effect and advantage is that, in turn, a faster transmission time can be achieved leading to the fact that the UE can enter earlier into a sleep mode, which leads to additional UE power saving.

[00139] The following are additional examples.

[00140] Example 1. A method, comprising:

[00141] at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link;

[00142] acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and

[00143] adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[00144] Example 2. The method of example 1, wherein the adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

[00145] Example 3. The method of any of examples 1 or 2, wherein the first network node provides information to the second network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels. [00146] Example 4. The method of example 3, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

[00147] Example 5. The method of example 4, further comprising:

[00148] determining by the first network node a split of guaranteed bit rate between the first and second network nodes based on a ratio of the first uplink transmit power level estimate and the second uplink transmit power level estimate; and

[00149] setting the guaranteed bit rate for the second network node based on the split of guaranteed bit rate between the first and second network nodes.

[00150] Example 6. The method of example 5, wherein:

[00151] the determining by the first network node a split of guaranteed bit rate between the first and second network nodes determines a portion of the guaranteed bit rate for the first network node; and

[00152] the adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels further comprises providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the first network node and based on a value of total buffer status reported by the user equipment.

[00153] Example 7. The method of example 6, wherein providing uplink grants comprises providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the first network node.

[00154] Example 8. The method of example 6, wherein providing uplink grants comprises scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the first network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

[00155] Example 9. The method of example 3, wherein the information comprises the first uplink transmit power level estimate.

[00156] Example 10. The method of example 9, further comprising calculating a portion of a value indicating total buffer status from the user equipment and allocated to the first network node, and wherein the adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

[00157] Example 11. The method of example 10, wherein calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the first network node further comprises calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

[00158] Example 12. The method any of examples 1 to 11, further comprising reevaluating the uplink radio resource allocations and performing the adapting based on the reevaluation, the reevaluating triggered at least by changes in uplink transmit power from the user equipment to one or both of the first or second network nodes.

[00159] Example 13. A method, comprising:

[00160] in a wireless network with first and second network nodes in a wireless network, where a user equipment is in dual connectivity to the first network node over a first radio link and to a second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link;

[00161] sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node;

[00162] adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

[00163] Example 14. The method of example 13, wherein the adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

[00164] Example 15. The method of any of examples 13 or 14, wherein the second network node receives information from the first network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels. [00165] Example 16. The method of example 15, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

[00166] Example 17. The method of example 16, wherein:

[00167] the adapting uplink radio resource allocations for second radio link comprises providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the second network node and based on a value of total buffer status reported by the user equipment.

[00168] Example 18. The method of example 17, wherein providing uplink grants comprises providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the second network node.

[00169] Example 19. The method of example 17, wherein providing uplink grants comprises scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the second network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

[00170] Example 20. The method of example 15, wherein the information comprises the first uplink transmit power level estimate and the adapting comprises adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

[00171] Example 21. The method of example 20, further comprising calculating a portion of a value indicating total buffer status from the user equipment and allocated to the second network node, and wherein the adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

[00172] Example 22. The method of example 21 , wherein calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the second network node further comprises calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

[00173] Example 23. A computer program, comprising code for performing the methods of any of examples 1 to 22, when the computer program is run on a computer. [00174] Example 24. The computer program according to example 23, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with the computer.

[00175] Example 25. The computer program according to example 23, wherein the computer program is directly loadable into an internal memory of the computer.

[00176] Example 26. An apparatus comprising means for performing:

[00177] at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link;

[00178] acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and

[00179] adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[00180] Example 27. The apparatus of example 26, wherein the means for adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

[00181] Example 28. The apparatus of any of examples 26 or 26, wherein the first network node provides information to the second network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

[00182] Example 29. The apparatus of example 28, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

[00183] Example 30. The apparatus of example 29, further comprising means for performing: [00184] determining by the first network node a split of guaranteed bit rate between the first and second network nodes based on a ratio of the first uplink transmit power level estimate and the second uplink transmit power level estimate; and

[00185] setting the guaranteed bit rate for the second network node based on the split of guaranteed bit rate between the first and second network nodes.

[00186] Example 31. The apparatus of example 30, wherein:

[00187] the means for determining by the first network node a split of guaranteed bit rate between the first and second network nodes determines a portion of the guaranteed bit rate for the first network node; and

[00188] the means for adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels further comprises means for providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the first network node and based on a value of total buffer status reported by the user equipment.

[00189] Example 32. The apparatus of example 31 , wherein the means for providing uplink grants comprises means for providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the first network node.

[00190] Example 33. The apparatus of example 31, wherein the means for providing uplink grants comprises means for scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the first network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

[00191] Example 34. The apparatus of example 28, wherein the information comprises the first uplink transmit power level estimate.

[00192] Example 35. The apparatus of example 33, further comprising means for performing calculating a portion of a value indicating total buffer status from the user equipment and allocated to the first network node, and wherein the adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value. [00193] Example 36. The apparatus of example 35, wherein the means for calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the first network node further comprises calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

[00194] Example 37. The apparatus any of examples 26 to 36, further comprising means for performing reevaluating the uplink radio resource allocations and performing the adapting based on the reevaluation, the reevaluating triggered at least by changes in uplink transmit power from the user equipment to one or both of the first or second network nodes.

[00195] Example 38. The apparatus of any of examples 26 to 38, wherein the means comprises:

[00196] at least one processor; and

[00197] at least one memory including computer program code,

[00198] the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[00199] Example 39. An apparatus, comprising means for performing:

[00200] in a wireless network with first and second network nodes in a wireless network, where a user equipment is in dual connectivity to the first network node over a first radio link and to a second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link;

[00201] sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node;

[00202] adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

[00203] Example 40. The apparatus of example 38, wherein the means for adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

[00204] Example 41. The apparatus of any of examples 38 or 39, wherein the second network node receives information from the first network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

[00205] Example 42. The apparatus of example 40, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

[00206] Example 43. The apparatus of example 41, wherein:

[00207] the means for adapting uplink radio resource allocations for second radio link comprises means for providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the second network node and based on a value of total buffer status reported by the user equipment.

[00208] Example 44. The apparatus of example 42, wherein the means for providing uplink grants comprises providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the second network node.

[00209] Example 45. The apparatus of example 42, wherein the means for providing uplink grants comprises means for scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the second network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

[00210] Example 46. The apparatus of example 40, wherein the information comprises the first uplink transmit power level estimate and the adapting comprises adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

[00211] Example 47. The apparatus of example 45, further comprising means for performing calculating a portion of a value indicating total buffer status from the user equipment and allocated to the second network node, and wherein the adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

[00212] Example 48. The apparatus of example 45, wherein the means for calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the second network node further comprises means for calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

[00213] Example 49. The apparatus of any of examples 39 to 49, wherein the means comprises:

[00214] at least one processor; and

[00215] at least one memory including computer program code,

[00216] the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[00217] Example 50. A communications system comprising an apparatus of any of examples 26 to 38 and an apparatus of any of examples 39 to 49.

[00218] Example 51. An apparatus, comprising:

[00219] one or more processors; and

[00220] one or more memories including computer program code,

[00221] wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising:

[00222] at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit powers level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link;

[00223] acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and

[00224] adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

[00225] Example 52. The apparatus of example 51, wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform the method in any of examples 2 to 12.

[00226] Example 53. An apparatus, comprising: [00227] one or more processors; and

[00228] one or more memories including computer program code,

[00229] wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising:

[00230] in a wireless network with first and second network nodes in a wireless network, where a user equipment is in dual connectivity to the first network node over a first radio link and to a second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link;

[00231] sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node;

[00232] adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

[00233] Example 54. The apparatus of example 53, wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform the method in any of examples 14 to 22.

[00234] As used in this application, the term “circuitry” may refer to one or more or all of the following:

[00235] (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

[00236] (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[00237] (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.”

[00238] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[00239] Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a “computer-readable medium” may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in FIG. 1. A computer-readable medium may comprise a computer-readable storage medium (e.g., memories 125, 155, 171 or other device) that may be any media or means that can contain, store, and/or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals.

[00240] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

[00241] Although various aspects are set out above, other aspects comprise other combinations of features from the described embodiments, and not solely the combinations described above.

[00242] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention. [00243] The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:

[00244] 3 GPP third generation partnership project

[00245] 5G fifth generation

[00246] 5GC 5G core network

[00247] AMF access and mobility management function

[00248] BSR buffer status reporting

[00249] BW bandwidth

[00250] CG cell group

[00251] CP control plane

[00252] cu central unit

[00253] DC dual connectivity

[00254] DCI downlink control information

[00255] DRB data radio bearer

[00256] DU distributed unit

[00257] eNB (or eNodeB) evolved Node B (e.g., an LTE base station)

[00258] EN-DC E-UTRA-NR dual connectivity

[00259] en-gNB or En-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as secondary node in EN-DC

[00260] EPC evolved packet core

[00261] E-UTRA evolved universal terrestrial radio access, i.e., the LTE radio access technology

[00262] GBR guaranteed bit rate

[00263] gNB (or gNodeB) base station for 5G/NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC

[00264] I/F interface

[00265] LTE long term evolution [00266] MAC medium access control

[00267] MCG master cell group

[00268] MIMO multiple in(put), multiple out(put)

[00269] MME mobility management entity

[00270] MN master node

[00271] MR-DC multi-RAT dual connectivity

[00272] ng or NG next generation

[00273] NGC next generation core

[00274] ng-eNB or NG-eNB next generation eNB

[00275] NR new radio

[00276] NR DC NR-NR dual connectivity

[00277] N/W orNW network

[00278] PCell primary cell

[00279] PDCP packet data convergence protocol

[00280] PDU protocol data unit

[00281] PHR power headroom report

[00282] PHY physical layer

[00283] PL path loss

[00284] PRB physical radio block

[00285] PSCell primary secondary cell

[00286] RAN radio access network

[00287] RAT radio access technologies

[00288] Rel release

[00289] RLC radio link control

[00290] RRC radio resource control

[00291] RRH remote radio head

[00292] RRM radio resource management

[00293] RSRP reference signal received power

[00294] RSRQ reference signal received quality

[00295] RU radio unit [00296] Rx receiver [00297] SCG secondary cell group [00298] SDAP service data adaptation protocol [00299] SGW or S-GW serving gateway [00300] SINR signal to interference plus noise ratio [00301] SMF session management function [00302] SN secondary node [00303] TDD time-division duplexing [00304] TPC transmit power control command [00305] TS technical specification [00306] Tx transmitter [00307] UCI uplink control information [00308] UE user equipment (e.g., a wireless, typically mobile device)

[00309] UP user plane [00310] UPF user plane function [00311] WID work-item description

Claims

CLAIMS What is claimed is:

1. A method, comprising: at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link; acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

2. The method of claim 1, wherein the adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

3. The method of any one of claims 1 or 2, wherein the first network node provides information to the second network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

4. The method of claim 3, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

5. The method of claim 4, further comprising: determining by the first network node a split of guaranteed bit rate between the first and second network nodes based on a ratio of the first uplink transmit power level estimate and the second uplink transmit power level estimate; and setting the guaranteed bit rate for the second network node based on the split of guaranteed bit rate between the first and second network nodes.

6. The method of claim 5, wherein: the determining by the first network node a split of guaranteed bit rate between the first and second network nodes determines a portion of the guaranteed bit rate for the first network node; and the adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels further comprises providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the first network node and based on a value of total buffer status reported by the user equipment.

7. The method of claim 6, wherein providing uplink grants comprises providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the first network node.

8. The method of claim 6, wherein providing uplink grants comprises scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the first network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

9. The method of claim 3, wherein the information comprises the first uplink transmit power level estimate.

10. The method of claim 9, further comprising calculating a portion of a value indicating total buffer status from the user equipment and allocated to the first network node, and wherein the adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

11. The method of claim 10, wherein calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the first network node further comprises calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

12. The method any one of claims 1 to 11, further comprising reevaluating the uplink radio resource allocations and performing the adapting based on the reevaluation, the reevaluating triggered at least by changes in uplink transmit power from the user equipment to one or both of the first or second network nodes.

13. A method, comprising : in a wireless network with first and second network nodes, where a user equipment is in dual connectivity to the first network node over a first radio link and to the second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link; sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node; and adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

14. The method of claim 13, wherein the adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

15. The method of any one of claims 13 or 14, wherein the second network node receives information from the first network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

16. The method of claim 15, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

17. The method of claim 16, wherein: the adapting uplink radio resource allocations for second radio link comprises providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the second network node and based on a value of total buffer status reported by the user equipment.

18. The method of claim 17, wherein providing uplink grants comprises providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the second network node.

19. The method of claim 17, wherein providing uplink grants comprises scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the second network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

20. The method of claim 15, wherein the information comprises the first uplink transmit power level estimate and the adapting comprises adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

21. The method of claim 20, further comprising calculating a portion of a value indicating total buffer status from the user equipment and allocated to the second network node, and wherein the adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

22. The method of claim 21 , wherein calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the second network node further comprises calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

23. A computer program, comprising code for performing the methods of any one of claims 1 to 22, when the computer program is run on a computer.

24. The computer program according to claim 23, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with the computer.

25. The computer program according to claim 23, wherein the computer program is directly loadable into an internal memory of the computer.

26. An apparatus comprising means for performing: at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link; acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

27. The apparatus of claim 26, wherein the means for adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

28. The apparatus of any one of claims 26 or 26, wherein the first network node provides information to the second network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

29. The apparatus of claim 28, wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

30. The apparatus of claim 29, further comprising means for performing: determining by the first network node a split of guaranteed bit rate between the first and second network nodes based on a ratio of the first uplink transmit power level estimate and the second uplink transmit power level estimate; and setting the guaranteed bit rate for the second network node based on the split of guaranteed bit rate between the first and second network nodes.

31. The apparatus of claim 30, wherein: the means for determining by the first network node a split of guaranteed bit rate between the first and second network nodes determines a portion of the guaranteed bit rate for the first network node; and the means for adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels further comprises means for providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the first network node and based on a value of total buffer status reported by the user equipment.

32. The apparatus of claim 31 , wherein the means for providing uplink grants comprises means for providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the first network node.

33. The apparatus of claim 31 , wherein the means for providing uplink grants comprises means for scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the first network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

34. The apparatus of claim 28, wherein the information comprises the first uplink transmit power level estimate.

35. The apparatus of claim 33, further comprising means for performing calculating a portion of a value indicating total buffer status from the user equipment and allocated to the first network node, and wherein the adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

36. The apparatus of claim 35, wherein the means for calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the first network node further comprises calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

37. The apparatus any one of claims 26 to 36, further comprising means for performing reevaluating the uplink radio resource allocations and performing the adapting based on the reevaluation, the reevaluating triggered at least by changes in uplink transmit power from the user equipment to one or both of the first or second network nodes.

38. The apparatus of any one of claims 26 to 38, wherein the means comprises: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

39. An apparatus, comprising means for performing: in a wireless network with first and second network nodes, where a user equipment is in dual connectivity to the first network node over a first radio link and to the second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link; sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node; and adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.

40. The apparatus of claim 39, wherein the means for adapting uplink radio resource allocations is performed so that a data radio bearer that is split in uplink for dual connectivity from the user equipment is transmitted primarily over whichever of the first or second radio links is a most power efficient uplink radio link, which is the radio link with a lowest uplink transmit power.

41. The apparatus of any one of claims 39 or 40, wherein the second network node receives information from the first network node for adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

42. The apparatus of claim 41 , wherein the information comprises a guaranteed bit rate for the second network node to use to adjust uplink resource grants to the user equipment.

43. The apparatus of claim 42, wherein: the means for adapting uplink radio resource allocations for second radio link comprises means for providing uplink grants for the user equipment that can accommodate an amount of data according to the portion of the guaranteed bit rate assigned to the second network node and based on a value of total buffer status reported by the user equipment.

44. The apparatus of claim 43, wherein the means for providing uplink grants comprises providing uplink grants to comply with a value of the portion of the guaranteed bit rate for the second network node.

45. The apparatus of claim 43, wherein the means for providing uplink grants comprises means for scaling the value of the total buffer status based on the portion of the guaranteed bit rate for the second network node and providing uplink grants that can accommodate an amount of data according to the scaled value.

46. The apparatus of claim 41, wherein the information comprises the first uplink transmit power level estimate and the adapting comprises adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels.

47. The apparatus of claim 46, further comprising means for performing calculating a portion of a value indicating total buffer status from the user equipment and allocated to the second network node, and wherein the adapting uplink radio resource allocations for the second radio link based on the first and second uplink transmit power levels comprises allocating uplink data for the user equipment based on the calculated portion of the value.

48. The apparatus of claim 46, wherein the means for calculating a portion of the value indicating the total buffer status from the user equipment and allocated to the second network node further comprises means for calculating the portion of the value using the first and second uplink transmit power level estimates and the value.

49. The apparatus of any one of claims 39 to 49, wherein the means comprises: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

50. A communications system comprising an apparatus of any one of claims 26 to 38 and an apparatus of any one of claims 39 to 49.

51. An apparatus, comprising : one or more processors; and one or more memories including computer program code, wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising: at a first network node in a wireless network, determining a first uplink transmit power level estimate for a first radio link from a user equipment in the wireless network to the first network node, wherein the first uplink transmit power level is for transmission in dual connectivity of the user equipment to the first network node over the first radio link; acquiring a second uplink transmit power level estimate for a second radio link from the user equipment to a second network node, wherein the second uplink transmit power level is for transmission in dual connectivity of the user equipment to the second network node over the second radio link; and adapting uplink radio resource allocations for the first radio link based on the first and second uplink transmit power levels.

52. An apparatus, comprising: one or more processors; and one or more memories including computer program code, wherein the one or more memories and the computer program code are configured, with the one or more processors, to cause the apparatus to perform operations comprising: in a wireless network with first and second network nodes in a wireless network, where a user equipment is in dual connectivity to the first network node over a first radio link and to a second network node over a second radio link, determining at the second node an uplink transmit power level estimate for the second radio link; sending from the second network node the uplink transmit power level estimate for the second radio link toward the first network node; and adapting uplink radio resource allocations for the second radio link based on at least second uplink transmit power levels.