UTRAN-NR INTERWORKING TECHNICAL FIELD:

[0001] The teachings in accordance with the example embodiments of this invention relate generally to network controlled mobility and, more specifically, relate to network controlled mobility in the context of E-UTRA-NR dual or multi-connectivity.

BACKGROUND:

[0002] This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

[0003] Certain abbreviations that may be found in the description and/or in the Figures are herewith defined as follows:

CA Carrier Aggregation

CU Centralized Unit

cmW centimetre wave

DC dual connectivity

DU Distributed Unit

eNB Evolved nodeB

EPC Evolved Packet Core

gNB Next generation NB (5G NB)

LTE Long Term Evolution

MAC Medium Access Control (protocol layer)

MME Mobility Management Entity (part of LTE EPC)

mmW millimiter wave

MN Master Node

NGC Next Generation Core

NR New Radio (5G RAT) PDCP Packet Data Convergence Protocol (protocol layer)

QoS Quality of Service

RAT Radio Access Technology

RLC Radio Link Control (protocol layer)

RRC Radio Resource Control

SCell Secondary Cell

SN Secondary Node

SRB Signaling Radio bearer

TRP Transmission Reception Point

UL Uplink

URLLCUltra-Reliable Low-Latency Communications

[0004] A present mobility framework in E-UTRAN-NR tight interworking scenario is detailed with 3 GPP agreements. In brief, the NR SN intra-frequency mobility is fully controlled by the SN including measurement configuration and processing, whereas both MN and SN may take control of NR inter-frequency mobility. Also, when the SN initiates a procedure for SN change, the MN would have the final decision of the SN change.

[0005] In certain circumstances where there is a SN-initiated change requiring MN-SN coordination and which implies UE reconfiguration (e.g. NR SCell change, security rekeying), the procedure requires additional signalling between MN and SN and associated latency, for the MN to be informed, perform the required checks and provide final acknowledgment / information to SN before the RRC command with the reconfiguration can be issued to the UE. Example embodiments of this invention propose at least a method to avoid and/or reduce such additional signalling and signalling latency.

SUMMARY:

[0006] Various aspects of examples of the invention are set out in the claims.

[0007] According to a first aspect of the present invention, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform at least the following: receiving, from a first network node of a communication network, an indication that a change of a transmission approach for multi-carrier communication between a mobile node and the communication network is needed, wherein the information comprises attributes associated with the transmission approach; coordinating with the first network node capabilities of the mobile node for operation with one or more secondary network nodes of a set of secondary nodes suitable for the change of the transmission approach; and based on coordinating, receiving from the first network node information comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations.

[0008] According to a second aspect of the present invention, a method comprising: receiving by a second network node, from a first network node of a communication network, an indication that a change of a transmission approach for multi-carrier communication between a mobile node and the communication network is needed, wherein the information comprises attributes associated with the transmission approach; coordinating with the first network node capabilities of the mobile node for operation with one or more secondary network nodes of a set of secondary nodes suitable for the change of the transmission approach; and based on coordinating, receiving from the first network node information comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi -connectivity operations.

[0009] According to a third aspect of the present invention, a computer program product comprising a non-transitory computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code comprising: receiving by a second network node, from a first network node of a communication network, an indication that a change of a transmission approach for multi-carrier communication between a mobile node and the communication network is needed, wherein the information comprises attributes associated with the transmission approach; coordinating with the first network node capabilities of the mobile node for operation with one or more secondary network nodes of a set of secondary nodes suitable for the change of the transmission approach; and based on coordinating, receiving from the first network node information comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations.

[0010] According to a fourth aspect of the present invention, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform at least the following: receiving, from a second network node of the communication network, a request to acknowledge that a change of a transmission approach for multi -connectivity communication between a mobile node and the communication network is needed; based on the receiving, sending information comprising an acknowledgement that the change of a transmission approach for multi -connectivity operations is needed, wherein the information comprises attributes associated with the transmission approach; coordinating with the second network node capabilities of the mobile node for operation with one or more secondary nodes of a set of secondary nodes suitable for the change of the transmission approach; and based on coordinating, sending information to the second network node comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations.

[0011] According to a fifth aspect of the present invention, a method comprising: receiving by a first network node of a communication network, from a second network node of the communication network, a request to acknowledge that a change of a transmission approach for multi-connectivity communication between a mobile node and the communication network is needed; based on the receiving, sending information comprising an acknowledgement that the change of a transmission approach for multi-connectivity operations is needed, wherein the information comprises attributes associated with the transmission approach; coordinating with the second network node capabilities of the mobile node for operation with one or more secondary nodes of a set of secondary nodes suitable for the change of the transmission approach; and based on coordinating, sending information to the second network node comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations.

[0012] According to a sixth aspect of the present invention, a computer program product comprising a non-transitory computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code comprising: receiving by a first network node of a communication network, from a second network node of the communication network, a request to acknowledge that a change of a transmission approach for multi-connectivity communication between a mobile node and the communication network is needed; based on the receiving, sending information comprising an acknowledgement that the change of a transmission approach for multi-connectivity operations is needed, wherein the information comprises attributes associated with the transmission approach; coordinating with the second network node capabilities of the mobile node for operation with one or more secondary nodes of a set of secondary nodes suitable for the change of the transmission approach; and based on coordinating, sending information to the second network node comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations.

BRIEF DESCRIPTION OF THE DRAWINGS:

[0013] The foregoing and other aspects of embodiments of this invention are made more evident in the following Detailed Description, when read in conjunction with the attached Drawing Figures, wherein: [0014] Figure 1 shows a high level block diagram of various devices used in carrying out various aspects of the invention;

[0015] Figure 2 shows non-standalone architecture Option 3/3a/3x;

[0016] Figure 3 shows a proposed mobility option for NR CU-DU split architectures;

[0017] Figure 4 shows a simplified illustrative example of signalling flow in accordance with the example embodiments; and

[0018] Figures 5A and 5B each show a method in accordance with example embodiments of the invention which may be performed by an apparatus.

DETAILED DESCRIPTION:

[0019] In this invention, there is proposed at least a method and apparatus that will improve network controlled mobility in the context of E-UTRA-NR dual or multi-connectivity.

[0020] As similarly stated above, a present mobility framework in such a scenario as a E- UTRAN-NR tight interworking scenario is detailed with 3GPP agreements such as wherein the NR SN intra-frequency mobility is fully controlled by the SN including measurement configuration and processing, and whereas both MN and SN may take control of NR inter- frequency mobility. Also, when the SN initiates a procedure for SN change, the MN would have the final decision of the change because of reasoning such as: a) X2/Xx/Xn connectivity: only MN knows whether it has backhaul connectivity with the target

SN;

b) Cell load information: only MN has the information of the SN cell load levels under its coverage as no SN-SN connectivity is present;

c) UE capability negotiation: the SN is aware of UE capabilities (NR incl. DC, in terms of e.g. band combination and Layer 2 buffer size support) which are provided by the MN over X2/Xx/Xn interface (or FFS if the SN can also request UE capability via Direct SCG SRB). However, MN-SN capability negotiation is still needed in case the SN would like to trigger a NR SCell change (e.g. Scell addition, modification, release), where the changed SCG band is out of inter-RAT band compatibility. This is because, the network has to make sure that the frequency range used for LTE one of shall or shall not overlap with the one for NR. Such coordination is deemed as necessary in particular for the case where LTE cells and NR cells are potentially configured with similar frequency bands. For the coordination, the SN should firstly send SgNB re-config request message to MN, MN can then either allow or refuse SN target band change. The negotiation is per the following agreement:

The MN should be involved in the SN cell change without PDCP change at least in the case where the UE capability coordination is required due to SN cell reconfiguration, (e.g., NR SCell change may require UE capability coordination); and/or

Security negotiation: It has been decided that LTE-NR DC will be based on LTE DC security model. For the option 3X where PDCP is terminated at the NR SN, this means that SN takes care of PDCP security (ciphering and integrity protection) based on keys derived from the S- K _g NB key. The MeNB needs to derive that key (S-K _g NB) based on K _g NB and provide it to the SN SgNB. In the case SN detects that security was compromised, SN should request MN to derive and provide to SN a new S -K _g NB key before it can change the current key and provide it to the UE.

[0021] Based on the above, in certain circumstances where there is a SN-initiated change requiring MN-SN coordination and which implies UE reconfiguration (e.g. NR SCell change, security rekeying), the procedure requires additional signaling between MN and SN and associated latency, for the MN to be informed, perform the required checks and provide final acknowledgment / information to SN before the RRC command with the reconfiguration can be issued to the UE. The example embodiments of the invention propose at least a method to avoid and/or reduce such additional signalling and the signalling latency. [0022] In accordance with an example embodiment of the invention there is proposed for E-

UTRAN-LTE DC a method to reduce/avoid MN-SN coordination latency upon SN related changes including security and mobility events which imply UE reconfiguration (e.g., via RRC signalling). [0023] Before describing the example embodiments of the invention in details, reference is made to Figure 1 for illustrating a simplified block diagram of various electronic devices that are suitable for use in practicing the example embodiments of this invention.

[0024] Figure 1 shows a block diagram of one possible and non-limiting exemplary system in which the example embodiments of the invention may be practiced. In Figure 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 may include an YYY module 140 which can be configured to perform the example embodiments of the invention as described herein. A YYY module 140 comprising one of or both parts 140-1 and/or 140-2, which may be implemented in a number of ways. The YYY module 140 may be implemented in hardware as YYY module 140-1, such as being implemented as part of the one or more processors 120. The YYY 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 YYY module 140 may be implemented as YYY 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, with the one or more processors 120, to cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with gNB 170 via a wireless link 111.

[0025] The gNB 170 (NR/5G/xG Node B or possibly an evolved NB) is a base station such as a secondary node base station (e.g., for NR or LTE long term evolution) that communicates with devices such as gNB 180 and UE 110 of Figure 1. The gNB 170 provides access to wireless devices such as the UE 110 to the wireless network 100. The gNB 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 gNB 170 includes a ZZZ module 150 which is configured to perform example embodiments of the invention as described herein. The ZZZ module 150 comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The ZZZ module 150 may be implemented in hardware as ZZZ module 150-1, such as being implemented as part of the one or more processors 152. The

ZZZ 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 ZZZ module 150 may be implemented as ZZZ 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 cause, with the one or more processors 152, the gNB 170 to perform one or more of the operations as described herein. The one or more network interfaces 161 communicate over a network such as via the links 176 and l l l . Two or more gNB 170 may communicate with another gNB or eNB using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, e.g., an X2 interface. Further the link 176 may be through other network devices such as, but not limited to an NCE/MME/SGW device such as the NCE/MME/SGW 190 of Figure 1.

[0026] The gNB 180 (NR/5G/xG Node B or possibly an evolved NB) is a base station such as a master node base station (e.g., for NR or LTE long term evolution) that communicates with devices such as the gNB 170 and/or UE 1 10 and/or the wireless network 100. The gNB 180 includes one or more processors 182, one or more memories 195, one or more network interfaces (N/W I F(s)) 191, and one or more transceivers 190 interconnected through one or more buses 187. Each of the one or more transceivers 190 includes a receiver Rx 192 and a transmitter Tx 183. The one or more transceivers 190 are connected to one or more antennas 185. The one or more memories 195 include computer program code 193. The gNB 180 also includes a ZZZ module 199 which is configured to perform example embodiments of the invention as described herein. The ZZZ module 199 may be implemented in hardware as ZZZ module 180-1, such as being implemented as part of the one or more processors 182. The ZZZ module 180-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the ZZZ module 180-1 may be implemented as ZZZ module 199, which is implemented as computer program code 193 and is executed by the one or more processors 182. For instance, the one or more memories 155 and the computer program code 153 are configured to cause, with the one or more processors 182, the gNB 180 to perform one or more of the operations as described herein. The one or more network interfaces 181 communicate over a network such as via the link 176. Two or more gNB 170 or gNB 180 may communicate with another gNB and/or eNB or any other device using, e.g., link 176. The link 176 maybe wired or wireless or both and may implement, e.g., an X2 interface. Further, as stated above the link 176 may be through other network devices such as, but not limited to an NCE/MME/SGW device such as the NCE/MME/SGW 190 of Figure 1. [0027] It is noted that the YYY modules and the ZZZ modules as described above are merely shown for example purposes to indicate a type of device or processor module which may be uniquely configured to perform the operations in accordance with the example embodiments of the invention as described herein. It is noted that any reference to these YYY modules and/or ZZZ modules in this paper is non-limiting, and the example embodiments of the invention may be performed using these modules and/or using other devices or modules as shown in Figure 1 or as described herein.

[0028] Further, it is noted that the operations in accordance with the example embodiments of the invention are not limit for use in only 5G, NR, and/or evolved NB radio networks. As indicated above with the reference xG of Figure 1 , the example embodiments of the invention as described herein may be applied for use and benefit in any future or present variations (e.g., xG) of 5G, NR, and/or evolved NB radio devices.

[0029] The one or more buses 157 and 187 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 and/or 190 may be implemented as a remote radio head (RRH) 203 and/or 205, with the other elements of the gNB 170 being physically in a different location from the RRH, and the one or more buses 157 could be implemented in part as fiber optic cable to connect the other elements of the gNB 170 to a RRH.

[0030] It is noted that description herein indicates that "cells" perform functions, but it should be clear that the gNB that forms the cell will perform the functions. The cell makes up part of a gNB. That is, there can be multiple cells per gNB.

[0031] The wireless network 100 may include a network control element (NCE) 190 that may include MME (Mobility Management Entity)/SGW (Serving Gateway) functionality, and which provides connectivity with a further network, such as a telephone network and/or a data communications network (e.g., the Internet). The gNB 170 is coupled via a link 131 to the NCE 190. The gNB 180 is coupled via a link 200 to the NCE 190. Further, the gNB 180 is coupled via link 176 to the gNB 170. The links 131, 176, and/or 200 maybe implemented as, e.g., an S l interface.

[0032] The NCE 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N/W I/F(s)) 197, interconnected through one or more buses coupled with the link 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 NCE 190 to perform one or more operations which may be needed to support the operations in accordance with the example embodiments of the invention. [0033] 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, 182, or 175 and memories 155, 195, and 171, and also such virtualized entities create technical effects.

[0034] The computer readable memories 125, 155, 171, and 195 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, 171 , and 195 may be means for performing storage functions. The processors 125, 155, 171, and 195 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, 175, and 182 may be means for performing functions, such as controlling the UE 110, gNB 170, gNB 180, and other functions as described herein.

[0035] In general, the various embodiments of the user equipment 1 10 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, 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 permitting wireless Internet access and browsing, tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions. [0036] 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 of an 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 Figure 1. A computer-readable medium may comprise a computer-readable storage medium or other device that may be any media or means that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

[0037] The example embodiments of the invention relate to network controlled mobility in the context of E-UTRA-NR dual connectivity (DC). Architecture options covered for E-UTRA- NR DC can be as follows:

E-UTRA-NR DC via EPC where the E-UTRA is the master (Option 3/3a/3x);

E-UTRA-NR DC via 5G-CN where the E-UTRA is the master (Option 7/7a/7x);

NR-E-UTRA DC via 5G-CN where the NR is the master (Option 4/4A).

[0038] An example embodiment of the invention may be used to an advantage for a non- standalone architecture Option 3/3a/3x, such as shown in Figure 2. As shown in Figure 2 there is option 3x where a gNB 220 (e.g., a secondary network node such as gNB 170 of Figure 1) is connected to an LTE eNB 210 (e.g., a master network node such as gNB 180 of Figure 1) via an Xx interface, such as an X2 interface (e.g. links 176 of Figure 1). In an operation with LTE-NR DC such as option 3X of Figure 2, NR CA are simultaneously activated, the SCell is the NR secondary (additional) carrier on top of NR PScell (Primary Scell) at the NR SN is in DC with the LTE MN Pcell (Primary cell).

[0039] In an option 3 example of Figure 2 the gNB 220 is receiving an SCG split bearer indication with a new radio packet data convergence protocol (NR PDCP). As shown in Option 3a of Figure 2 the LTE eNB 210 decides the -c configuration and sends a "SeNB addition request" message to the NR eNB (e.g., gNB 220), including the "MCG configuration" and necessary UE capability information for the NR eNB to select the NR SCG configuration. [0040] It is noted that in accordance with the example embodiments a "Transmission approach" may be defined as a secondary cell, a secondary transmission point, and/or a transmission beam configuration for multi -carrier communications. Further, in accordance with the example embodiments the transmission approach can be defined and changed using control commands implemented with "code" such as scrambling code(s) and/or encryption code(s).

Further, in accordance with the example embodiments the encryption code for the transmission approach can operates on a different protocol layer than the scrambling code.

[0041] Further, in accordance with the example embodiments of the invention the control commands can be implemented with "Attributes". These Attributes could be related to a carrier frequency, bandwidth, power, number of carriers, number of codes, number of beams, etc. of a transmission approach. The "control commands" using the attributes could be used to command at least (1) acceptance of operation, (2) rejecting operation in suggested way, (3) enforcing alternative operation, and/or (4) suggesting alternative operation (e.g., using specific attributes).

[0042] Further, an alternative operation in accordance with the embodiments could cause a trigger of a new request to define specific operations and/or control commands. In accordance with the example embodiments a negotiation for these could follow.

[0043] The example embodiments of the invention may also be used to an advantage for a case where a splitting RAN architecture into CU (Centralized Unit) and DU (Distributed Unit) is adopted. That is, a number of DUs (also called gNB-DU) are present and controlled under a NR CU (also called gNB-CU). The DUs could operate different frequencies, either at cm-wave bands (between 3 GHz and 30 GHz) or mm- wave (30 GHz- 300 GHz). Furthermore, there may be a number of transmission reception points (TRxP), present under a gNB as illustrated in the figure below. Although it is open in current studies, for instance at which protocol layer a split between CU and DU will be enforced, herein it may be assumed that a) NR PDCP is located at the CU and b) RRC signaling is required for inter-DU mobility (DU change).

[0044] Figure 3 shows one proposed mobility option for NR CU-DU split architectures. As shown in Figure 3 there is a centralized unit CU 310 which is performing dual connectivity operations with distributed units DU 320 and DU 330. Under each of the distributed units DU 320 and DU 330 use transmission reception points (TRP) 340. The TRPs are numbered #1 to #K, where K is an integer. As shown in Figure 3 there is are factors causing a needed transmission approach change for the dual connectivity. These factors include a beam change, TRP change and/or DU change which can require a need for a change of a distributed unit for a secondary cell for multi-carrier communication. The Example embodiments of the invention relate to controlling such a needed transmission approach change using less signaling and with less latency, including a change of a distributing unit and/or a cell.

[0045] One main context for application of the example embodiments is for E-UTRAN-NR tight interworking (dual -/multi-connectivity) where LTE acts as the master and NR as secondary node:

Master node (MN) = LTE eNB

Secondary node (SN) = NR gNB, and NR adopts the CU-DU architecture

[0046] In accordance with the example embodiments of the invention there is, for E- UTRAN-LTE DC for example, a method to reduce/avoid MN-SN coordination latency upon SN related changes incl. security and mobility events which imply UE reconfiguration (via RRC signaling). This can be realized via SN-initiated pre-negotiation operations with the MN, which can be enabled / activated by MN for specific bearer types (e.g. URLLC bearers with tight latency requirements).

[0047] In a first application in accordance with the example embodiments, hereafter referred to as application #1, there is UE capability pre-negotiation. Here, to avoid the latency added by the MN-SN capability negotiation related to NR SCell change (e.g., Scell addition, modification, release), an SN pre-requests (whenever needed) the acknowledgement from MN of SCell change for a certain "cell set of relevance for a given UE", i.e., the set of potential SCell targets for the UE. For example, first the network maintains (and adjusts dynamically) the "cell set of relevance for a given UE"; second, the SN and MN resolve the UE capability coordination in respect of such set before the actual need to perform a SCell change to any of the cells within the set; third, the network may send timely the SCell reconfiguration to the UE when the network algorithm determines the benefit to do so. The example embodiments herein saves the latency introduced by the exchange of SgNB Re-config request message SN to MN and SgNB Re-config ACK complete message from MN to SN, if those happen just prior to the RRC reconfiguration.

[0048] In another application in accordance with the example embodiments, hereafter referred to as application #2, there is a Security key pre-negotiation. Here, to avoid the latency added by the MN-SN coordination (for the SN request and MN provisioning to SN) of a new S- K _g NB key, the SN pre-requests from the MN a new S-K _g NB key derivation and provisioning before the need arises without putting the new key immediately to use upon its reception from the MN, instead being ready to timely put it to use if needed, e.g. if SN detects that security was compromised. Promptly at the time it is needed to be put into use, the network can send the reconfiguration to the UE with the new key (derivation) without further delays (due to the latency of MN-SN coordination).

[0049] These applications in accordance with the example embodiments are relevant in both the traditional architecture as well as in the splitting RAN architecture. An example of application #1 to the splitting RAN architecture is when the gNB-CU (central unit) is maintained while the UE moves across (i.e. changes) gNB-DUs (distributed units) that are connected to the MN via the same gNB-CU. This maintaining would include SCell modifications. Since the gNB-CU will potentially have detailed information on the capabilities and load situation of the gNB-DUs that are served by it (e.g., information of gNB-DU mobility events while being served by the same gNB-CU), this obviously resolves mentioned issues. These mentioned issues about the existence of the backhaul connectivity (prerequisite for DC) and the availability of cell load knowledge at the gNB-CU (needed for load balancing purposes). The example embodiments of this invention solve also the Scell change related coordination. This means that in such scenario the intra-CU mobility can be autonomously controlled by the SN transparently to the MN at the time it is applied, minimizing and anticipating the involvement of the MN in the SN change decision.

[0050] A simplified illustrative example of the signaling flow proposed by this invention is shown in Figure 4 for the (non-limiting) case where SCell modifications are performed when changing also DU. In this example, the MN and SN coordinates the control of SN SCell change, and within such procedure the SN can be granted "autonomous mobility / pre-negotiation mode". The mode could be decided during existing X2/Xn/Xx procedures such as: SN Addition Preparation, MN initiated SN Modification Preparation, and/or MN initiated SN Modification Preparation.

[0051] In Figure 4 as shown there is a UEl 410, MN 420, gNB-CU 430, Source gNB-DUl 440, Target gNB-DU2 450, and New Target gNB-DU3 460. At step 412 of Figure 4 there is an E_UTRAN-NR dual connectivity (DC) established, including a SN autonomous change / pre- negotiation mode" activated. At step 414 there is RRC signaling including measurements from the UEl 410 to the gNB-CU 430, signaling is also provided to the source gNB-DUl 440. At steps 415 and 416 of Figure 4 there are operations of determining that a change of a secondary cell for the DC with the UEl 410 and the Source gNB-DUl 440 is needed. These operations of step 416 include X2/Xn/Xx cell load exchange from DUs under the gNB-CU 430, UE capability negotiation for Scells of from the Target gNB-DU2450 to the New Target gNB-DU3 460. Then at step 417 the gNB-CU 430 receives RRC signaling including a DU change command and ACK, the RRC signaling is then provided to the UE1 410. At step 418 of Figure 4 RACH procedure and UL resources are granted, and the gNB-CU updates a "gNB-DU/cells relevance set" for the UE1 410 adding target gNB-DU3/Scells to the set based on at least the UE measurements. At step 419 of Figure 4 there is UE capability negotiation for Scells of New Target gNB-DU3 460. [0052] In accordance with the example embodiments of the invention the network can determine the SN set of relevance for a given UE configured in E-UTRAN-NR DC. Although the exact algorithm for that is optional, it is assumed that the network can determine and track the UE location and trajectory on the basis of e.g. UE measurements incl. geo-location measurements. Depending on the SCell bands in that set vs. MN bands, and the need/benefit for NR CA, the SN (gNB-CU) will initiate the UE capability negotiation necessary to check that certain SCell change are allowed in order for the NR gNB to select the correct NR SCG configuration incl. SCell change at the time that the SN change is decided and implemented.

[0053] The example embodiments in accordance with the invention allow a reduction of associated signaling and latency required by negotiation between SN and MN for an SN or SN cell change. This is beneficial particularly for those services which are delay sensitive such as URLLC.

[0054] In an example, in the scenario when an LTE eNB and 5G gNB-CU connection is maintained while the UE, configured in LTE-NR DC, moves across gNB-DUs, the proposed invention makes NR SN mobility completely transparent to the MN, providing a more efficient method to perform the required mobility procedure completely by the SN side, i.e., avoiding extra signaling and latency needed for MN-SN negotiation procedures, related to e.g. UE capability negotiation of SCell change. Also, for the nature of the mm-wave (severe propagation loss is caused at their high frequency), a mm-wave DU may cover only small physical areas implying a potential large amount of DU changes when a UE is moving across an area of mm- wave DUs which may operate with a large bandwidth benefiting of carrier aggregation (therefore implying a potential large amount of SCell change procedures). [0055] Figure 5a illustrates operations which may be performed by a network device such as, but not limited to, a user device (e.g., gNB 170 as in Figure 1). As shown in step 510 if Figure 5 a there is receiving by a second network node, from a first network node of a communication network, an indication that a change of a transmission approach for multi-carrier communication between a mobile node and the communication network is needed, wherein the information comprises attributes associated with the transmission approach. As shown is step 520 there is coordinating with the first network node capabilities of the mobile node for operation with one or more secondary network nodes of a set of secondary nodes suitable for the change of the transmission approach. Then as shown in step 530 of Figure 5a there is, based on coordinating, receiving from the first network node information comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations.

[0056] In accordance with the example embodiments as described in the paragraph above, the first network node comprises a master node of the communication network. [0057] In accordance with the example embodiments as described in the paragraphs above, the transmission approach comprises a secondary cell, a secondary transmission point, and a transmission beam for the multi-carrier communication.

[0058] In accordance with the example embodiments as described in the paragraphs above, the transmission approach is based on a scrambling code or encryption code which operates on a different protocol layer than a scrambling code.

[0059] In accordance with the example embodiments as described in the paragraphs above, the attributes comprise one or more of a carrier identifier, a carrier frequency, bandwidth, a power, a number of carriers, a number of codes, and a number of beams associated with the transmission approach.

[0060] In accordance with the example embodiments as described in the paragraphs above, the control commands cover one or more attributes for use by the mobile node for at least one of acceptance of operation, rejecting operation in suggested way, enforcing alternative operation, and suggesting alternative operation using specific attributes.

[0061] In accordance with the example embodiments as described in the paragraphs above, there is forwarding the information comprising the control commands covering the one or more attributes to the mobile node for the change of the transmission approach. [0062] In accordance with the example embodiments as described in the paragraphs above, the information comprising the control commands covering the one or more attributes is forwarded to the mobile node over radio resource control signaling. [0063] In accordance with the example embodiments as described in the paragraphs above, the coordinating comprises: coordinating, with the first network node, security credentials to be provisioned to the mobile node for the change of the transmission approach, wherein the information from the first network node comprises the security credentials. [0064] In accordance with the example embodiments as described in the paragraphs above, the security credentials comprise a new S-K _gn b key.

[0065] In accordance with the example embodiments as described in the paragraphs above, the first network node comprises one of an LTE and a 5G/new radio or next generation base station, and wherein the second network node comprises one of a distributed unit or a centralized unit 5G/new radio or next generation base station.

[0066] In accordance with the example embodiments as described in the paragraphs above, the coordinating comprises ensuring that a frequency range used for the change of the transmission approach shall or shall not overlap with the one for a new radio technology used by the distributed unit or the centralized unit 5G/new radio or next generation base station.

[0067] In accordance with the example embodiments as described in the paragraphs above, the set of secondary nodes is dynamically updated based on signal measurements or geo-location measurements received from the mobile node.

[0068] In accordance with the example embodiments as described in the paragraphs above, there is sending to the first network node, a request for acknowledgement of the indication of the change of the transmission approach comprising the attributes associated with the transmission approach.

[0069] A non-transitory computer-readable medium (one or more memories 155 of Figure 1) storing program code (e.g., Computer Program Code 153 of Figure 1), the program code executed by at least one processor (e.g., Processor(s) 152 and/or ZZZ Module 150-1 and/or ZZZ Module 153 of Figure 1) to perform the operations as at least described in the paragraphs above. [0070] In accordance with an example embodiment of the invention as described above there is an apparatus comprising: means for receiving (e.g., Antennas 158 and transceiver 160 of Figure 1) from a first network node (e.g., gNB 180 of Figure 1) of a communication network (e.g., network 100 of Figure 1), by a second network node (e.g., gNB 170 of Figure 1) of the communication network, an indication that a change of a transmission approach for multi-carrier communication between a mobile node (e.g., UE 110 of Figure 1) and the communication network is needed, wherein the information comprises attributes associated with the transmission approach. As shown is step 520 there is coordinating (e.g., Computer Program Code 153, and e.g., Processor(s) 152 and/or ZZZ Module 150-1 and/or ZZZ Module 153 of Figure 1) with the first network node capabilities of the mobile node for operation with one or more secondary network nodes of a set of secondary nodes suitable for the change of the transmission approach. Then as shown in step 530 of Figure 5a there is, based on coordinating (e.g., Computer Program Code 153, and e.g., Processor(s) 152 and/or ZZZ Module 150-1 and/or ZZZ Module 153 of Figure 1), receiving (e.g., Antennas 158 and transceiver 160 of Figure 1) from the first network node information comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi- connectivity operations.

[0071] In the example aspect of the invention according to the paragraph above, wherein at least the means for receiving and coordinating comprises a non-transitory computer readable medium (e.g., memories(s) 155 of Figure 1) encoded with a computer program (e.g., Computer Program Code 153 of Figure 1) executable by at least one processor (e.g., Processor(s) 152 and/or ZZZ Module 150-1 and/or ZZZ Module 153 of Figure 1). [0072] Figure 5b illustrates operations which may be performed by a network device such as, but not limited to, a master node gNB (e.g., gNB 180 as in Figure 1). As shown in step 550 of Figure 5b there is receiving by a first network node of a communication network, from a second network node of the communication network, a request to acknowledge that a change of a transmission approach for multi -connectivity communication between a mobile node and the communication network is needed. As shown in step 560 of Figure 5b there is based on the receiving, sending information comprising an acknowledgement that the change of a transmission approach for multi-connectivity operations is needed, wherein the information comprises attributes associated with the transmission approach. In step 570 there is coordinating with the second network node capabilities of the mobile node for operation with one or more secondary nodes of a set of secondary nodes suitable for the change of the transmission approach. Then as shown in step 580 of Figure 5b there is based on coordinating, sending information to the second network node comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi- connectivity operations. [0073] In accordance with the example embodiments as described in the paragraph above, the first network node comprises a master node of the communication network.

[0074] In accordance with the example embodiments as described in the paragraphs above, the transmission approach comprises a secondary cell, a secondary transmission point, and a transmission beam for the multi-carrier communication.

[0075] In accordance with the example embodiments as described in the paragraphs above, the transmission approach is based on a scrambling code or encryption code which operates on a different protocol layer than a scrambling code.

[0076] In accordance with the example embodiments as described in the paragraphs above, the attributes may comprise one or more of a carrier identifier, carrier frequency, bandwidth, a power, a number of carriers, number of codes, and a number of beams associated with the transmission approach.

[0077] In accordance with the example embodiments as described in the paragraphs above, the control commands cover one or more attributes for use by the mobile node for at least one of acceptance of operation, rejecting operation in suggested way, enforcing alternative operation, and suggesting alternative operation using specific attributes.

[0078] In accordance with the example embodiments as described in the paragraphs above, the information comprising the control commands covering the one or more attributes is sent to the second network node over radio resource control signaling. [0079] In accordance with the example embodiments as described in the paragraphs above, the coordinating comprises: coordinating, with the first network node, security credentials to be provisioned to the mobile node for the change of the transmission approach, wherein the information sent to the first network node comprises the security credentials. [0080] In accordance with the example embodiments as described in the paragraphs above, the security credentials comprise a new S-K _gn b key. [0081] In accordance with the example embodiments as described in the paragraphs above, the first network node comprises one of an LTE and a 5G/new radio or next generation base station, and wherein the second network node comprises one of a distributed unit or a centralized unit 5G/new radio or next generation base station.

[0082] In accordance with the example embodiments as described in the paragraphs above, the coordinating comprises ensuring that a frequency range used for the change one of shall or shall not overlap with the one for a new radio technology used by the distributed unit or the centralized unit 5G/new radio or next generation base station.

[0083] In accordance with the example embodiments as described in the paragraphs above, there is receiving at least one of signal measurements and geo-location measurements from the mobile node; and based on the at least one of signal measurements and geo-location measurements dynamically updating the set of secondary nodes relevant for the change of the transmission approach.

[0084] A non-transitory computer-readable medium (one or more memories 155 of Figure 1) storing program code (e.g., Computer Program Code 193 of Figure 1), the program code executed by at least one processor (e.g., Processor(s) 182 and/or ZZZ Module 180-1 and/or ZZZ Module 199 of Figure 1 ) to perform the operations as at least described in the paragraphs above.

[0085] In accordance with an example embodiment of the invention as described above there is an apparatus comprising: means for receiving (e.g., Antennas link 185 and transceiver 190 of Figure 1) by a first network node (e.g., gNB 180 of Figure 1) of a communication network (e.g., network 100 of Figure 1), from a second network node (e.g., gNB 170 of Figure 1) of the communication network, a request to acknowledge that a change of a transmission approach for multi-connectivity communication between a mobile node and the communication network is needed; means, based on the receiving, for sending (e.g., Antennas link 185 and transceiver 190 of Figure 1) information comprising an acknowledgement that the change of a transmission approach for multi-connectivity operations is needed, wherein the information comprises attributes associated with the transmission approach; means for coordinating (e.g., Computer Program Code 195, and e.g., Processor(s) 182 and/or ZZZ Module 180-1 and/or ZZZ Module 199 of Figure 1), with the second network node capabilities of the mobile node for operation with one or more secondary nodes of a set of secondary nodes suitable for the change of the transmission approach; and means, based on coordinating, for sending (e.g., Antennas link 185 and transceiver 190 of Figure 1) information to the second network node comprising control commands covering one or more attributes for use by the mobile node for the change of the transmission approach for the multi-connectivity operations. [0086] In the example aspect of the invention according to the paragraph above, wherein at least the means for receiving, sending, and coordinating comprises a non-transitory computer readable medium (e.g., memories(s) 195 of Figure 1) encoded with a computer program (e.g., Computer Program Code 195 of Figure 1) executable by at least one processor (e.g., Processor(s) 182 and/or ZZZ Module 180-1 and/or ZZZ Module 199 of Figure 1).

[0087] In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which maybe executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0088] Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0089] 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.

[0090] The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the best method and apparatus presently contemplated by the inventors for carrying out the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

[0091] It should be noted that the terms "connected," "coupled," or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.

[0092] Furthermore, some of the features of the preferred embodiments of this invention could be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles of the invention, and not in limitation thereof.