WO2018059704A1

WO2018059704A1 - Communication control for uplink data in multi-connectivity communication mode

Info

Publication number: WO2018059704A1
Application number: PCT/EP2016/073382
Authority: WO
Inventors: Henri Markus Koskinen
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2018-04-05

Abstract

An apparatus comprising at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least: to conduct a communication procedure for participating in a multi-connectivity communication of at least one communication element, to prepare a multi-connectivity control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication to limit a rate of data forwarded by the at least one second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication, and to cause sending the multi-connectivity control indication to the at least one second communication network control element or function.

Description

DESCRIPTION

TITLE

COMMUNICATION CONTROL FOR UPLINK DATA IN MULTI-CONNECTIVITY

COMMUNICATION MODE

DESCRIPTION

BACKGROUND Field

The present invention relates to apparatuses, methods, systems, computer programs, computer program products and computer-readable media usable for controlling communication of uplink data in a communication environment allowing multi- connectivity communication.

Background Art

The following description of background art may include insights, discoveries, understandings or disclosures, or associations, together with disclosures not known to the relevant prior art, to at least some examples of embodiments of the present invention but provided by the invention. Some of such contributions of the invention may be specifically pointed out below, whereas other of such contributions of the invention will be apparent from the related context.

The following meanings for the abbreviations used in this specification apply:

3GPP 3^rd Generation Partnership Project

AMBR: aggregate maximum bit rate

BS: base station

CN: core network

CPU: central processing unit

DC: dual connectivity eNB: evolved node B

EPC: evolved packet core

ERAB: E-UTRAN radio access bearer

E-UTRAN: evolved UMTS terrestrial radio access network

IE: information element

LTE: Long Term Evolution

LTE-A: LTE Advanced

LWA: LTE-WLAN aggregation

MAC: medium access control

MCG: master cell group

MeNB: master eNB

MME: mobility management element

NR: new radio

PDCP: packet data convergence protocol

PGW: packet gateway

RAB: radio access bearer

RAT: radio access technology

RLC: radio link control

SCG: secondary cell group

SeNB: secondary eNB

SGW: serving gateway

UE: user equipment

UMTS: universal mobile telecommunication system

WLAN: wireless local area network

Embodiments of the present invention are related to a communication system in which a suitable architecture, procedure and protocol are provided with regard to a functionality allowing a suitable control for uplink data communication in a multi-connectivity communication scenario, such as a dual connectivity communication, between communication network control elements or functions (such as base stations of different RATs).

Embodiments of the present invention are related to a mechanism which allows to suitably control the processing load of a master base station in a multi-connectivity communication scenario so as to avoid data loss or the like. SUMMARY

According to an example of an embodiment, there is provided, for example, an apparatus comprising at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least: to conduct a communication procedure for participating in a multi- connectivity communication of at least one communication element, to prepare a multi- connectivity control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication to limit a rate of data forwarded by the at least one second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi- connectivity communication, and to cause sending the multi-connectivity control indication to the at least one second communication network control element or function.

Furthermore, according to an example of an embodiment, there is provided, for example, a method comprising conducting a communication procedure for participating in a multi- connectivity communication of at least one communication element, preparing a multi- connectivity control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication to limit a rate of data forwarded by the at least one second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi- connectivity communication, and causing sending the multi-connectivity control indication to the at least one second communication network control element or function. According to further refinements, these examples may include one or more of the following features:

- an available capacity in the first communication network control element or function for processing uplink data received by the at least one second communication network control element or function and to be processed by the first communication network control element or function in the multi-connectivity communication may be determined, wherein for determining the available capacity, at least one of a current processing load of the first communication network control element or function and an actual rate of data being forwarded by the at least one second communication network element or function may be considered;

- the multi-connectivity control indication may comprises one of a limitation indication providing each of the at least one second communication network control element or function with a limit value for the rate of data forwarded by the at least one second communication network control element or function to the first communication network control element or function, and a grant indication that allows the at least one second communication network control element or function to forward an indicated maximum amount of data to the first communication network control element or function;

- the data contained in the all uplink data received by the at least one second communication network control element or function from the at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication may be data forwarded on a specific bearer type including at least one of a switched bearer and a split bearer in the multi- connectivity communication;

- the multi-connectivity control indication may be related exclusively to data forwarded by the at least one second communication network control element or function via the specific bearer type;

- the multi-connectivity communication may be a dual connectivity communication, wherein the first communication network control element or function may be a master communication network control element or function and the second communication network control element or function may be a secondary communication network control element or function of the dual connectivity communication, wherein the multi- connectivity control indication may be prepared for a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type; - the first communication network control element or function may be configured to control a different type of communication network than the at least one second communication network control element or function, wherein the communication element may include a user equipment or terminal device configured to communicate in each of the communication networks controlled by the first communication network control element or function and the at least one second communication network control element or function in the multi-connectivity communication;

- the above processing may be part of the first communication network control element or function.

Furthermore, according to an example of an embodiment, there is provided, for example, an apparatus comprising at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least: to conduct a communication procedure for participating, as a second communication network control element or function, in a multi-connectivity communication of at least one communication element, to receive and process a multi- connectivity control indication for controlling the second communication network control element or function to limit a rate of data forwarded by the second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the second communication network control element or function from at least one communication element in the multi-connectivity communication, and to adjust a rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication.

In addition, according to an example of an embodiment, there is provided, for example, a method comprising conducting a communication procedure for participating, as a second communication network control element or function, in a multi-connectivity communication of at least one communication element, receiving and processing a multi- connectivity control indication for controlling the second communication network control element or function to limit a rate of data forwarded by the second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the second communication network control element or function from at least one communication element in the multi-connectivity communication, and adjusting a rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication.

According to further refinements, these examples may include one or more of the following features:

- the multi-connectivity control indication may comprise one of a limitation indication providing a limit value for the rate of data forwarded by the second communication network control element or function to the first communication network control element or function, and a grant indication that allows the second communication network control element or function to forward an indicated maximum amount of data to the first communication network control element or function;

- data contained in the all uplink data received by the second communication network control element or function from the at least one communication element and to be processed by the first communication network control element or function in the multi- connectivity communication may be data forwarded on a specific bearer type including at least one of a switched bearer and a split bearer in the multi-connectivity communication;

- the multi-connectivity control indication may be related exclusively to data forwarded by the second communication network control element or function via the specific bearer type;

- when adjusting of the rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication, a rate of scheduling of bearers transporting the data being forwarded may be limited;

- the multi-connectivity communication may be a dual connectivity communication, wherein the first communication network control element or function is a master communication network control element or function and the second communication network control element or function is a secondary communication network control element or function of the dual connectivity communication, wherein the multi- connectivity control indication may be related to a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type.

- the first communication network control element or function may be configured to control a different type of communication network than the second communication network control element or function, wherein the communication element may include a user equipment or terminal device configured to communicate in each of the communication networks controlled by the first communication network control element or function and the second communication network control element or function in the multi-connectivity communication.

In addition, according to embodiments, there is provided, for example, a computer program product for a computer, including software code portions for performing the steps of the above defined methods, when said product is run on the computer. The computer program product may include a computer-readable medium on which said software code portions are stored. Furthermore, the computer program product may be directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures. BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 shows a diagram illustrating a general architecture of a communication system where some examples of embodiments are implementable;

Fig. 2 shows a diagram illustrating a radio protocol architecture for dual connectivity where some examples of embodiments are applicable;

Fig. 3 shows a flow chart of a processing conducted in a communication network control element or function according to some examples of embodiments;

Fig. 4 shows a flow chart of a processing conducted in a communication network control element or function according to some examples of embodiments;

Fig. 5 shows a diagram of a communication network control element according to some examples of embodiments; and Fig. 6 shows a diagram of a communication network control element according to some examples of embodiments.

DESCRIPTION OF EMBODIMENTS

In the last years, an increasing extension of communication networks, e.g. of wire based communication networks, such as the Integrated Services Digital Network (ISDN), DSL, or wireless communication networks, such as the cdma2000 (code division multiple access) system, cellular 3^rd generation (3G) like the Universal Mobile Telecommunications System (UMTS), fourth generation (4G) communication networks or enhanced communication networks based e.g. on LTE or LTE-A, fifth generation (5G) communication networks, cellular 2^nd generation (2G) communication networks like the Global System for Mobile communications (GSM), the General Packet Radio System (GPRS), the Enhanced Data Rates for Global Evolution (EDGE), or other wireless communication system, such as the Wireless Local Area Network (WLAN), Bluetooth or

Worldwide Interoperability for Microwave Access (WiMAX), took place all over the world. Various organizations, such as the European Telecommunications Standards Institute (ETSI), the 3^rd Generation Partnership Project (3GPP), Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN), the International Telecommunication Union (ITU), 3^rd Generation Partnership Project 2 (3GPP2), Internet

Engineering Task Force (IETF), the IEEE (Institute of Electrical and Electronics Engineers), the WiMAX Forum and the like are working on standards or specifications for telecommunication network and access environments. Generally, for properly establishing and handling a communication connection between two or more end points (e.g. communication stations or elements, such as terminal devices, user equipments (UEs), or other communication network elements, a database, a server, host etc.), one or more network elements such as communication network control elements, for example access network elements like access points, radio base stations, eNBs etc., operation and maintenance elements, and core network elements or functions, for example control nodes, support nodes, service nodes, gateways etc., may be involved, which may belong to one communication network system or different communication network systems. Embodiments as well as principles described below are applicable to any communication network control element or management control element or function, such as a network element, a relay node, a server, a node, a corresponding component, and/or to any communication system or any combination of different communication systems that support required functionalities. The communication system may be a fixed communication system, a wireless communication system or a communication system utilizing both fixed network parts and wireless network parts. The protocols being used, the specifications of communication systems, apparatuses, such as nodes, servers and user terminals, especially in wireless communication, develop rapidly. Such development may require extra changes to an embodiment. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, embodiments.

In the following, different exemplifying embodiments will be described using, as an example of an access architecture to which the embodiments may be applied, a radio access architecture based on 3GPP standards, such as a fourth generation (like LTE or LTE-A) communication network, without restricting the embodiments to such an architecture, however. It is obvious for a person skilled in the art that the embodiments may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately, e.g. WLAN or WiFi, worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs), new radio (NR) and the like.

The following examples and embodiments are to be understood only as illustrative examples. Although the specification may refer to "an", "one", or "some" example(s) or embodiment(s) in several locations, this does not necessarily mean that each such reference is related to the same example(s) or embodiment(s), or that the feature only applies to a single example or embodiment. Single features of different embodiments may also be combined to provide other embodiments. Furthermore, terms like "comprising" and "including" should be understood as not limiting the described embodiments to consist of only those features that have been mentioned; such examples and embodiments may also contain features, structures, units, modules etc. that have not been specifically mentioned. A basic system architecture of a communication system where examples of embodiments are applicable may include an architecture of one or more communication networks including a wired or wireless access network subsystem and a core network. Such an architecture may include one or more communication network control elements, access network elements, radio access network elements, access service network gateways or base transceiver stations, such as a base station (BS), an access point or an eNB, which control a respective coverage area or cell(s) (also referred to as a cell group) and with which one or more communication elements, user devices or terminal devices, such as a UE, or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of an element, function or application capable of conducting a communication, such as a UE, an element or function usable in a machine to machine or device to device communication architecture, or attached as a separate element to such an element, function or application capable of conducting a communication, or the like, are capable to communicate via one or more channels for transmitting several types of data. Furthermore, core network elements such as gateway network elements, management element such as mobility management entities, operation and maintenance elements, and the like may be included.

The general functions and interconnections of the described elements, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof is omitted herein. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from an element, function or application, like a communication element, such as a UE, a communication network control element, such as an eNB, a gateway node like a SGW, a core network control element like a MME or another core network element, and other elements of the same or other communication networks besides those described in detail herein below.

A communication network may also be able to communicate with other networks, such as a local area network, a public switched telephone network or the Internet. The communication network may also be able to support the usage of cloud services. It should be appreciated that network elements of an access system, of a core network etc., and/or respective functionalities may be implemented by using any node, host, server or access node etc. entity suitable for such a usage. Furthermore, virtual network functions may be implemented as a corresponding network element or function.

Furthermore, the described network elements, such as communication elements, like a UE, communication network control elements, access network elements etc., like an eNB, core network elements, like MME etc., as well as corresponding functions as described herein, and other elements, functions or applications may be implemented by software, e.g. by a computer program product for a computer, and/or by hardware. For executing their respective functions, correspondingly used devices, nodes or network elements may include several means, modules, units, components, etc. (not shown) which are required for control, processing and/or communication/signaling functionality. Such means, modules, units and components may include, for example, one or more processors or processor units including one or more processing portions for executing instructions and/or programs and/or for processing data, storage or memory units or means for storing instructions, programs and/or data, for serving as a work area of the processor or processing portion and the like (e.g. ROM, RAM, EEPROM, and the like), input or interface means for inputting data and instructions by software (e.g. floppy disc, CD-ROM, EEPROM, and the like), a user interface for providing monitor and manipulation possibilities to a user (e.g. a screen, a keyboard and the like), other interface or means for establishing links and/or connections under the control of the processor unit or portion (e.g. wired and wireless interface means, radio interface means including e.g. an antenna unit or the like, means for forming a radio communication part etc.) and the like, wherein respective means forming an interface, such as a radio communication part, can be also located on a remote site (e.g. a radio head or a radio station etc.). It is to be noted that in the present specification processing portions should not be only considered to represent physical portions of one or more processors, but may also be considered as a logical division of the referred processing tasks performed by one or more processors. It should be appreciated that according to some examples, a so-called "liquid" or flexible network concept may be employed where the operations and functionalities of a communication network element, network function, or of another entity of the communication network may be performed in different entities or functions, such as in a node, host or server, in a flexible manner. In other words, a "division of labor" between involved network elements, functions or entities may vary case by case. ln order to handle the ongoing growth of communication demands and data traffic, operators of communication networks are employing different measures. One example is the employment of so called small cells. Small cells are, for example, low-powered radio access nodes that operate in licensed and unlicensed spectrum and have a smaller range compared to so-called macro cells. Small cells can be used, for example for mobile data offloading by using available radio spectrum more efficiently.

In other words, in order to improve the performance of communication networks, and in particular mobile communication systems, one approach is to increase the number of network nodes so as to enable a decrease of distance between user and network node so as to improve traffic capacity and extending the achievable user data rates of a wireless communication system. By deploying complementary low-power nodes e.g. under the coverage of an existing macro-node layer, also referred to as a heterogeneous network structure, high traffic capacity and high user throughput can be provided locally, for example in indoor and outdoor hotspot positions.

In current and future network systems, such as LTE or LTE-A networks, enhancements related to low-power nodes and heterogeneous deployments are considered, for example, as so-called small-cell enhancement activities. In this context, interworking between the macro and low-power layers, including different forms of macro assistance to the low-power layer and dual connectivity are taken into account.

However, it has been found that small cell enhancements may lead, from higher layer aspects, to additional challenges, in particular when a macro cell and small cells are connected via non-ideal backhaul. These challenges comprise mobility robustness, throughput enhancements and increased signaling load due to frequent handover.

To address these challenges, a so-called dual-connectivity (DC) approach is considered. DC implies that a communication element such as a UE has simultaneous connections to both macro and other (e.g. low-power) layers. A separation of control and data is possible, where, for example, the control signaling for mobility is provided via the macro layer at the same time as data connectivity is provided via the low-power layer. DC is an operation where a given UE, while in RRC_CONNECTED state, consumes radio resources provided by at least two different network points (also referred to as master and secondary nodes, such as MeNB and SeNB) which are connected with non- ideal backhaul. When the UE is simultaneously connected to MeNB and SeNB, throughput and mobility robustness gains can be achieved. That is, DC aims to utilize the radio resource within multiple carriers to improve UE throughput. DC is for non-ideal backhaul, e.g. relatively large delay between nodes.

In one example of a DC implementation, user traffic of a bearer is split in PDCP. For example, in this DC example, the data bearer which is split in PDCP is called split bearer. In control plane, there is only one S1 -MME connection and it is between MME and MeNB. RRC connection only terminates at MeNB. All SeNB-related RRC configuration is transmitted to MeNB which then transmits RRC message to UE.

In other words, in DC, a UE is simultaneously connected with an MeNB and an SeNB, wherein control plane (RRC) for the UE is terminated in MeNB and not in SeNB. In particular, MeNB acts as mobility anchor towards the core network. MeNB is changed only at handover, while SeNB may be added or released depending on the needs as determined by MeNB (e.g. by means of an addition procedure). For example, the SeNB provides additional radio resources to the UE.

The group of the serving cells associated with the MeNB is named Master Cell Group (MCG), and the group of the serving cells associated with the SeNB is named Secondary Cell Group (SCG). MCG contains at least the Primary cell (PCell) and may contain one or more Secondary cells (SCells). SCG contains at least the Primary Scell (PSCell) and may contain one or more SCells.

With regard to Fig. 1 , a diagram illustrating a general architecture of a communication system is shown where some examples of embodiments are implementable. It is to be noted that the structure indicated in Fig. 1 shows only those devices, network elements and links which are useful for understanding principles underlying the examples of embodiments of the invention. As also known by those skilled in the art there may be several other network elements or devices involved in a communication in the communication system which are omitted here for the sake of simplicity. In Fig. 1 , a communication network is shown which forms a general basis of the example of a communication system according to some examples of embodiments. Specifically, as the network, a (wireless) communication network based for example on an LTE specification is provided. It is to be noted that both the number of network elements as well as the type thereof, which are depicted in Fig. 1 , are merely intended to provide a basis for illustrating the principles of a communication control processing according to some examples of embodiments, while each one of the number and type of the involved network elements may be different to those shown in Fig. 1.

According to Fig. 1 , reference sign 10 denotes a communication element, such as a UE, e.g. of a subscriber which represents one terminal point of a communication, i.e. for which one or more bearers, such as ERAB, are to be set up and used for communicating data to and from another terminal point of the communication. It is to be noted that according to examples of embodiments the UE 10 is assumed to be capable of conducting a dual connectivity operation mode.

Reference sign 20 denotes an access network subsystem via which the UE 10 is connected to the communication network. The access network subsystem 20 comprises, for example, base stations, access nodes or the like. Specifically, as an illustrative but not limiting example, the access network 20 according to Fig. 1 comprises a base station which acts as a master base station in a DC communication, such as an MeNB.

Reference sign 30 denotes another access network subsystem via which the UE 10 is connected to the communication network. The access network subsystem 30 comprises, for example, base stations, access nodes or the like. Specifically, as an illustrative but not limiting example, the access network 20 according to Fig. 1 comprises a base station which acts as a secondary base station in a DC communication, such as an SeNB.

It is to be noted that the access network subsystems 20 and 30 may be of the same or of different RAT types. For example, the RATs may comprise one of an LTE or LTE-A system, a WLAN system, a NR system and the like. Furthermore, the access network subsystems may comprise a plurality of small base stations which may each act as a SeNB in case of a dual connectivity operation mode. In the following, the MeNB 20 is also referred to as a first communication network control element or function, while the SeNB 30 is also referred to as second communication network control element or function. Furthermore, it is to be noted that even though reference is made to the eNB as a communication network control element or function, also another form of base station or access point, such as a WLAN AP, is to be understood by this expression.

Reference sign 40 denotes a management control element of the CN, such as a MME of the EPC, which is configured to deal with a control plane and to handle signaling related to mobility and security for E-UTRAN access.

Reference sign 50 denotes a control element of the CN, which comprises a gateway function acting as a serving gateway (SGW) and/or a gateway to an external side, such as a packet gateway (not shown).

For connecting the elements and nodes indicated in Fig. 1 , corresponding reference points or interfaces are defined. Fig. 1 shows examples of such interfaces and reference points under consideration of the LTE or LTE-A implementation, but it is obvious that in other implementations the used interfaces and reference points may be different. For example, in case the secondary base station 30 is represented by a WLAN AP, a link is provided by another type of interface (e.g. an Xw interface).

Specifically, in the 3GPP LTE or LTE-A system depicted in Fig. 1 , the MME 40 is connected to the MeNB 20 via S1 -MME. The SGW 50 is connected at least to the MeNB 20 and possibly also to the SeNB 30 via S1 -U (for user plane). A connection between the MeNB 20 and the SeNB 30 is provided by X2-C/U (both user and control plane). Connection between the MeNB 20 and the SeNB 30 and the UE 10 is provided, for example, via Uu.

It is to be noted that even though Fig. 1 shows only one UE 10 and a limited number of eNBs (MeNB and SeNB), it is obvious that also other configurations are feasible. For example, more than one UE can be connected to any of the eNBs. Furthermore, as indicated above, it is assumed that the system and the communication element (UE 10) are configured to communicate in dual connectivity operation mode so that one or more bearers can be established between the UE 10 and at least two eNBs (e.g. MeNB 20 and SeNB 30). The MeNB, at which e.g. the S1 -MME terminates, is configured to perform all necessary S1 -MME related functions (as specified for any serving eNB) such as mobility management, ERAB handling, etc. and manages the handling of user plane connection. As indicated above, in DC operation mode, it is possible to split a bearer over multiple eNBs, which is also referred to as bearer split. Specifically, according to examples of embodiments, the MeNB 20 is configured to carry control plane data to and from the UE 10 and to and from the MME 40. Additionally the MeNB 20 is configured to carry control plane data to and from the SeNB 30. For this, there is provided the S1 -MME interface between the MeNB 20 and MME 40 and the X2-C interface between the MeNB 20 and the SeNB 30.

When there are MeNB bearers (or MCG bearers), control plane data are transferred between the MeNB 20 and MME 40 as well as between the MeNB 20 and the UE 10. User plane data are provided between SGW 50 and the MeNB 20 and between the

MeNB 20 and the UE 10. Thus the bearers carrying the user plane data are MeNB bearers.

In case of SeNB bearers (or SCG bearers), control plane data are transferred between the MeNB 20 and the MME 40 as well as between the MeNB 20 and the UE 10. User plane data are provided between the SGW 50 and the SeNB 30 and between the SeNB 30 and the UE 10. For SeNB bearers, a user plane is directly connected between SGW 50 and SeNB 30. The bearers for carrying user plane data to and from the UE 10 are SeNB bearers.

On the other hand, when the bearers are split bearers, control plane data are transferred between the MeNB 20 and the MME 40 as well as between the MeNB 20 and the UE 10. User plane data is provided between the SGW 50 and the MeNB 20, the MeNB 20 and the SeNB 30, the MeNB 20 and the UE 10, and the SeNB 30 and the UE 10. That is, the bearers for carrying user plane data to and from the UE 10 are split between the

MeNB 20 and the SeNB 30. That is, for split bearers, the MeNB 20 is U-plane connected to the SGW 50 via S1 -U and in addition, the MeNB 20 and the SeNB 30 are interconnected via X2-U. Fig. 2 shows a diagram illustrating a radio protocol architecture for DC where some examples of embodiments are applicable, wherein the concept of split bearers in the example illustrated in Fig. 1 is described in further detail. Specifically, as shown in Fig. 2, the radio protocol architecture that a particular bearer uses depends on how the bearer is setup. For the MCG bearer, PDCP and RLC are located in the MeNB 20, while for SCG bearer PDCP and RLC are located in the SeNB 30. It is to be noted that signaling radio bearers are always configured as MCG bearer type and therefore only use the radio resources of the MeNB 20. On the other hand, for the split bearer, PDCP is located in the MeNB 20, while at least part of the data are transferred to/from the RLC in the SeNB 30.

However, in dual-connectivity operation across different RATs, when uplink data received over one RAT are forwarded to a base station of another RAT for further processing, the following may occur.

For example, considering an example where a DC operation including split and switched bearers provided by any two of access network, such as an LTE eNB, a WLAN AP, and a base station operating the 3GPP New RAT (NR), is conducted. It is to be noted that a split bearer, for example in a LTE-WLAN aggregation scenario, refers to a bearer whose radio protocols are located in both the LTE part (the eNB) and the WLAN part to use both eNB and WLAN radio resources, while a switched bearer refers to, for example, in the LTE-WLAN aggregation scenario, to a bearer whose radio protocols are located in both the LTE part (the eNB) and the WLAN part but uses WLAN radio resources only. When now an uplink split- or switched-bearer operation is conducted across base stations of different RATs, the processing capability of the base station that connects the bearer to the core network (i.e. the MeNB 20 in Fig. 1 ) may be a bottleneck.

For instance, if an LTE-NR split bearer is provided to the UE 10 such that the SeNB 30 of Fig. 1 is an NR base station, the PDCP at the (LTE) MeNB 20 has to de-cipher also the uplink data of that bearer received by the NR base station (the SeNB 30) from the UE 10 and forwarded to the MeNB 20 (via X2, for example). In this situation, it is possible that the LTE MeNB 20 is insufficiently dimensioned with regard to processing capability and hence not be able to process the kind of bit rates that the SeNB 30 (here the NR base station) is able to provide. A similar situation can be envisioned when providing split or switched bearers in the LTE-WLAN aggregation scenario (e.g. SeNB 20 is an WLAN AP), supporting e.g. the latest high-speed IEEE 802.1 1 variants.

Conventionally, in such a situation, one approach is that the MeNB 20 processes only the uplink packets that it is able to, while it discards those being received in excess of that. This means that reception of the discarded uplink packets wastes radio resources.

Another approach is that the master base station (i.e. the MeNB 30) conducts a control with regard to a maximum bit rate being transferred between the communication network control elements being involved in the DC communication. For example, a corresponding mechanism is represented by SeNB UE-AMBR, consisting of downlink and uplink components. By means of a suitable signaling related to the UE-AMBR in DC, the MeNB ensures that the AMBR is not exceeded. For this purpose, the resources the MeNB allocates to the UE in MCG are limited, and the SeNB is informed about a limit so that the SeNB can also in turn guarantee that this limit is not exceeded. In other words, the

MeNB requests the SeNB to prepare resources for DC operation for a specific UE by informing the SeNB about an aggregate maximum bit rate for the UE in question, wherein the UE aggregate maximum bit rate is split into a MeNB UE aggregate maximum bit rate and a SeNB UE aggregate maximum bit rate. These which are enforced by MeNB and SeNB respectively.

However, the current approaches are not optimal especially for uplink data processing.

Hence, according to examples of embodiments of the invention, another approach is considered. Specifically, according to examples of embodiments, a signalling indication is sent to the SeNB by which the first base station (MeNB 20) is able to indicate to the second base station (SeNB 30) a restriction to the total rate of uplink data forwarded on specific type(s) of bearer by the second base station to the first base station. In other words, the indication is related to limit a total rate of uplink data received by the second base station and to be processed by the first base station.

In other words, the signalling (or control) indication aims to limit a rate of those data which are 1 ) uplink data being received by the SeNB from any communication element (UEs) being connected to it (i.e. the control indication is not related exclusively to one UE), and 2) only those data (from the uplink data, irrespective of their source) which are forwarded from t e SeNB to the MeNB for processing, i.e. those data being received via the specific bearer type (e.g. split and/or switched bearer). That is, all uplink data forwarded from the SeNB to the MeNB for processing by the MeNB are subject to the limitation, but the SeNB may receive other uplink data which are not concerned, i.e. those uplink data which are not forwarded to the MeNB, and hence are not subject to the limitation.

According to some examples of embodiments, for the indication to be signalled, also referred to as multi-connectivity (or dual connectivity) control indication hereinafter, several different forms can be applied.

For example, the indication can have the form of a value or parameter representing a limitation indication, such as a semi-static maximum supported rate. For example, when the first base station, such as an eNB acting as the MeNB, has a plurality of different assisting (secondary) base stations, each thereof can be controlled in accordance with their own varying load conditions. Hence, the limitation indication like the semi-static maximum supported rate is set per each pair of {master base station, secondary base station}.

Another form is a grant indication allowing the SeNB to forward an indicated maximum amount of data to the MeNB, for example. For example, the grant indication can be used to provide a feedback to the SeNB indicating which amount of data (e.g. X bytes of data) are maximally allowed to be forwarded further to the MeNB. This indication can be provided repeatedly, either event triggered or in a regular interval. A further example of a grant indication is to possibly provide a dynamic feedback indication allowing the master base station to instruct the secondary base station to lower or raise again the total rate of uplink data forwarded. By means of the grant indication, varying communication conditions (e.g. changes in the QoS state, the number of active DC communications etc.) can be flexibly considered and the setting of the total rate of data being forwarded can be adapted accordingly. Also balancing between a plurality of secondary base stations in case of conducting more than one DC communication is possible in a suitable manner and can be adjusted flexibly.

The indication can be communicated to the secondary base station in a suitable manner, e.g. by using an existing signalling path. For example, a new IE can be prepared and included in a setup communication, such as in a Xw SETUP REQUEST message between the LTE eNB acting as the MeNB and the WLAN AP acting as the SeNB.

Fig. 3 shows a flow chart of a processing conducted in a communication network control element, such as the MeNB 20, according to some examples of embodiments. Specifically, the example according to Fig. 3 is related to a control procedure conducted by the communication network control element, function or node acting as an MeNB in the communication network as depicted e.g. in Fig. 1 . That is, Fig. 3 shows a processing which is implemented, for example, in the MeNB as the first communication network control element or function, but a corresponding processing can be also conducted by another part of the network.

In S100, a communication procedure for participating in a multi-connectivity communication of at least one communication element (UE) is conducted. For example, according to some examples of embodiments, a first communication network control element or function, such as the MeNB 20, being configured to control a first type of communication network, and one or more second communication network control element or function, such as the SeNB 30, are involved, wherein the second communication network control element or function is configured to control a second type of communication network which is of the same type or of a different type like the first one. The communication element, which is, for example, a UE or a terminal device of another form (computer or the like) is configured to communicate in each type of the communication networks controlled by the first communication network control element or function and the at least one second communication network control element or function in the multi-connectivity communication (e.g. in dual connectivity communication mode).

In S1 10, an available capacity in the first communication network control element or function for processing uplink data received by the at least one second communication network control element or function and to be processed by the first communication network control element or function in the multi-connectivity communication is determined. In other words, the available capacity of the MeNB 20 for processing uplink data forwarded by the SeNB 30 is determined. For this determination, for example, a current processing load of the MeNB 20 and/or an actual rate of data being forwarded by the at least one second communication network element or function is considered. In S120, a multi-connectivity (or dual connectivity) control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication is prepared. The goal of the control indication is to limit a rate of data forwarded by the at least one second communication network control element or function to the first communication network control element or function participating in the multi-connectivity communication. In particular, the control indication is related to those data being forwarded which contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication. In other words, the control indication aims to those data which are 1 ) uplink data being received by the (at least one) second communication network control element or function from any of the communication elements being connected to it, and 2) only those data (from the uplink data, irrespective of their source) which are forwarded from the second communication network control element or function to the first communication network control element or function (that is, for example, data being received via a split/switched bearer).

According to some examples of embodiments, the control indication is a limitation indication providing each of the at least one second communication network control element or function with a limit value for the rate of data forwarded by the at least one second communication network control element or function to the first communication network control element or function. Alternatively, according to some further examples of embodiments, the control indication is a grant indication allowing the at least one second communication network control element or function to forward an indicated maximum amount of data to the first communication network control element or function.

In S130, the control indication is sent to the at least one second communication network control element or function.

It is to be noted that according to some examples of embodiments, the uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication (i.e. the data to which the control indication is related) are data forwarded on a specific bearer type. The specific bearer type may include e.g. one or more of a switched bearer and a split bearer in the multi-connectivity communication.

Furthermore, the multi-connectivity control indication is related exclusively to the data forwarded by the at least one second communication network control element or function via the specific bearer type. In other words, other data (or bearer) being handled by the at least one second communication network control element or function are not affected. For example, in case the SeNB 30 has also a SCG bearer towards the UE 10, the data rate of this bearer is not controlled by the control indication, as these data are not to be processed by the MeNB 20.

That is, as a specific example of embodiments, when the multi-connectivity communication is a dual connectivity communication, the first communication network control element or function is a master communication network control element or function and the second communication network control element or function is a secondary communication network control element or function of the dual connectivity communication, while the control indication is prepared for a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type.

It is to be noted that S1 10 may be also omitted, i.e. the actual processing capacity may either be assumed to be a preset value, and hence already known, or another network element, such as a core network element, determines and provides a value to be used for the limitation of the data rate (i.e. the preparation of the control limit in S120).

Fig. 4 shows a flow chart of a processing conducted in a communication network control element, such as the SeNB 30, according to some examples of embodiments. Specifically, the example according to Fig. 4 is related to a control procedure conducted by the communication network control element, function or node acting as an SeNB in the communication network as depicted e.g. in Fig. 1 . That is, Fig. 4 shows a processing which is implemented, for example, in the SeNB as the second communication network control element or function, but a corresponding processing can be also conducted by another part of the network ln S200, a communication procedure for participating in a multi-connectivity communication of at least one communication element (UE) is conducted. For example, according to some examples of embodiments, a first communication network control element or function, such as the MeNB 20, being configured to control a first type of communication network, and one or more second communication network control element or function, such as the SeNB 30, are involved, wherein the second communication network control element or function is configured to control a second type of communication network which is of the same type or of a different type like the first one. The communication element, which is, for example, a UE or a terminal device of another form (computer or the like) is configured to communicate in each of the communication networks controlled by the first communication network control element or function and the at least one second communication network control element or function in the multi-connectivity communication (e.g. in dual connectivity communication mode).

In S210, a multi-connectivity (or dual connectivity) control indication for controlling the second communication network control element or function participating in the multi- connectivity communication is received and processed. The control indication indicates a limitation of a rate of data forwarded by the second communication network control element or function to the first communication network control element or function participating in the multi-connectivity communication. In particular, the control indication is related to those data being forwarded which contain all uplink data received by the second communication network control element or function from at least one communication element in the multi-connectivity communication. According to examples of embodiments, the uplink data are those to be processed by the first communication network control element or function. In other words, the control indication aims to those data which are 1 ) uplink data being received by the second communication network control element or function from any of the communication elements being connected to it, and 2) only those data (from the uplink data, irrespective of their source) which are forwarded from the second communication network control element or function to the first communication network control element or function (that is, for example, data being received via a split/switched bearer).

According to some examples of embodiments, the control indication is a limitation indication providing the second communication network control element or function with a limit value for t e rate of data forwarded by the at least one second communication network control element or function to the first communication network control element or function. Alternatively, according to some further examples of embodiments, the control indication is a grant indication that allows the second communication network control element or function to forward an indicated maximum amount of data to the first communication network control element or function.

In S220, the control indication is used to adjust a rate of data forwarded to the first communication network control element or function. For example, the adjusting of the rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication comprises limiting a rate of scheduling of bearers transporting the data being forwarded. This allows, for example, to use radio resources being released by limiting a rate of scheduling of bearers being impacted by the limitation caused by the control indication for other bearers being not impacted, e.g. resources being used formerly for (now restricted) split bearers for SCG bearers, or the like, so as to improve the rates thereof, or the like.

It is to be noted that according to some examples of embodiments, the uplink data received by the at least one second communication network control element or function and to be processed by the first communication network control element or function in the multi-connectivity communication (i.e. the data to which the control indication is related) are data forwarded on a specific bearer type. The specific bearer type may include e.g. one or more of a switched bearer and a split bearer in the multi-connectivity communication.

Furthermore, the multi-connectivity control indication is related exclusively to the data forwarded by the second communication network control element or function via the specific bearer type. In other words, other data (or bearer) being handled by the second communication network control element or function are not affected. For example, in case the SeNB 30 has also a SCG bearer towards the UE 10, the data rate of this bearer is not controlled by the control indication, as these data are not to be processed by the MeNB 20.

Fig. 5 shows a diagram of a communication network control element according to some examples of embodiments, which is configured to implement a control procedure as described in connection with some of the examples of embodiments. It is to be noted that the communication network control element, like the MeNB 20, which is shown in Fig. 5, may include further elements or functions besides those described herein below. Furthermore, even though reference is made to a communication network control element or node, the element or node may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a communication network control element or attached as a separate element to a communication network control element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry.

The communication network control element shown in Fig. 5 may include a processing circuitry, a processing function, a control unit or a processor 21 , such as a CPU or the like, which is suitable for executing instructions given by programs or the like related to the control procedure. The processor 21 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 22 and 23 denote transceiver or input/output (I/O) units or functions (interfaces) connected to the processor or processing function 31 . The I/O units 22 may be used for communicating with other network elements, such as the MME 40, the SGW 50, the SeNB 30, and the like. The I/O units 23 may be used for communicating with a communication element, such as the UE 10, and the like. The I/O units 22 and 23 may be a combined unit including communication equipment towards several network elements, or may include a distributed structure with a plurality of different interfaces for different network elements. Reference sign 24 denotes a memory usable, for example, for storing data and programs to be executed by the processor or processing function 21 and/or as a working storage of the processor or processing function 21 . It is to be noted that the memory 24 may be implemented by using one or more memory portions of the same or different type of memory.

The processor or processing function 21 is configured to execute processing related to the above described control procedure. In particular, the processor or processing circuitry or function 21 includes one or more of the following sub-portions. Sub-portion 210 is a processing portion which is usable for determining a current capacity of for data processing in the MeNB 20. The portion 210 may be configured to perform processing according to S1 10 of Fig. 3. Furthermore, the processor or processing circuitry or function 21 may include a sub-portion 21 1 usable as a portion for preparing the control indication. The portion 21 1 may be configured to perform a processing according to S120 of Fig. 3. In addition, the processor or processing circuitry or function 21 may include a sub-portion 212 usable as a portion for sending the control indication. The portion 212 may be configured to perform a processing according to S130 of Fig. 3.

Fig. 6 shows a diagram of a communication network control element according to some examples of embodiments, which is configured to implement a control procedure as described in connection with some of the examples of embodiments. It is to be noted that the communication network control element, like the SeNB 30, which is shown in Fig. 6, may include further elements or functions besides those described herein below.

Furthermore, even though reference is made to a communication network control element or node, the element or node may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a communication network control element or attached as a separate element to a communication network control element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry. The communication network control element shown in Fig. 6 may include a processing circuitry, a processing function, a control unit or a processor 31 , such as a CPU or the like, which is suitable for executing instructions given by programs or the like related to the control procedure. The processor 31 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 32 and 33 denote transceiver or input/output (I/O) units or functions (interfaces) connected to the processor or processing function 31 . The I/O units 32 may be used for communicating with other network elements, such as the the SGW 50, the MeNB 20, and the like. The I/O units 33 may be used for communicating with a communication element, such as the UE 10, and the like. The I/O units 32 and 33 may be a combined unit including communication equipment towards several network elements, or may include a distributed structure with a plurality of different interfaces for different network elements. Reference sign 34 denotes a memory usable, for example, for storing data and programs to be executed by the processor or processing function 31 and/or as a working storage of the processor or processing function 31 . It is to be noted that the memory 34 may be implemented by using one or more memory portions of the same or different type of memory.

The processor or processing function 31 is configured to execute processing related to the above described control procedure. In particular, the processor or processing circuitry or function 31 includes one or more of the following sub-portions. Sub-portion 310 is a processing portion which is usable for receiving and processing a control indication from the MeNB 20. The portion 310 may be configured to perform processing according to S210 of Fig. 4. Furthermore, the processor or processing circuitry or function 31 may include a sub-portion 31 1 usable as a portion for adjusting a data rate. The portion 31 1 may be configured to perform a processing according to S220 of Fig. 4.

As described above, according to examples of embodiments, procedures are provided allowing a suitable and flexible control for uplink data communication in a multi- connectivity communication scenario, such as a dual connectivity communication, between communication network control elements or functions (such as base stations of different RATs), wherein the processing load and capability of a master base station in a multi-connectivity communication scenario is considered and data loss or the like can be avoided. For example, while measures including e.g. UE-AMBR can control the rate of data only per UE, the control indication according to examples of embodiments is per pair of base stations co-operating on certain type of bearers. This means that only the data rate of bearers involving both base stations are concerned, while other bearers are left alone. For example, in case an assisting base station (SeNB 30) e.g. in tight LTE-NR interworking can simultaneously have split bearers and SCG bearers for a UE, the conventional SeNB UE-AMBR procedure would apply to both types of bearers, whereas the proposed control indication concerns only the split bearers while it does not apply to the SCG bearers (because its data is not forwarded to the MeNB). Furthermore, the control indication according to examples of embodiments is applicable also in cases where a given pair of master and secondary base stations provide dual connectivity to more than one UEs at one time. Here, when a number of applicable UEs changes during operation, the distribution of processing capacity of the MeNB changes, which can be considered by using the control indication of examples of embodiments of the invention, while a procedure including implementation-specific indications of SeNB

UE-AMBR would require a complex re-distribution of the new available capacity of the MeNB among the remaining UE-specific SeNB UE-AMBRs.

It is to be noted that, while in the above described examples of embodiments, a dual connectivity scenario is considered involving two RATs and/or two communication network control elements, examples of embodiments of the invention are not limited thereto. For example, the principles regarding the communication control discussed above are applicable also in case where more than two communication network control elements, in particular more than one SeNB, are involved. In other words, the principles of the above discussed examples of embodiments are also applicable to a multi connectivity communication scenario.

Furthermore, as indicated above, a parameter or value related to the processing capacity and hence to the limit to be set by the control indication for the rate of data forwarded by the second communication network control element or function to the first communication network control element or function may be determined in the first communication network control element or function, or a preset or calculated value obtained from another network element, e.g. a CN network element. As indicated above, according to some examples of embodiments, the first communication network control element or function is configured to control one type of RAT (e.g. LTE) while the second communication network control element or function is configured to control a comparable type of RAT or another type of RAT (e.g. WLAN, NR, or the like). This applies also for the case when more than one second communication network control element or function are involved, wherein each thereof may control an own (different type of) RAT. Furthermore, the communication element, which includes e.g. a UE or another type of terminal device (e.g. a computer, smartphone etc.) can communicate in each of the involved RATs controlled by the respective first and second communication network control elements or functions so as to participate in the multi- connectivity communication.

According to examples of embodiments described above, elements or functions of the above described mechanism regarding the multi-connectivity control indication are part of the first communication network control element or function (i.e. the MeNB 20), for example. However, it is also possible that other network elements or functions conduct a corresponding processing for providing the control indication. For example, examples of embodiments of the present invention are applicable to a scenario where a signaling indication (dual connectivity or multi connectivity control indication) having an effect as discussed above is generated or triggered by an operation of another network control element or function being different to those discussed above, such as MeNB. for example by means of an implementation-specific configuration mechanism, such as operation and maintenance or the like.

Furthermore, it is to be noted that in the above discussed sequence of processing as described in connection with the flow charts according to Figs. 3 and 4 no strict time order is required. For example, considering e.g. S200 and S210, the time order may be variably set, meaning e.g. that the control indication can be received and processed at a later point of time when the dual (multi) connectivity communication is already running, or being received beforehand so that the corresponding setting is known already when a dual (multi) connectivity communication starts. According to a further example of embodiments, there is provided, for example, an apparatus comprising means configured to conduct a communication procedure for participating in a multi-connectivity communication of at least one communication element, means configured to prepare a multi-connectivity control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication to limit a rate of data forwarded by the at least one second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication, and means configured to cause sending the multi-connectivity control indication to the at least one second communication network control element or function.

Furthermore, according to some other examples of embodiments, the above defined apparatus may further comprise means for conducting at least one of the processing defined in the above described methods, for example a method according that described in connection with Fig 3.

According to a further example of embodiments, there is provided, for example, an apparatus comprising means configured to conduct a communication procedure for participating, as a second communication network control element or function, in a multi- connectivity communication of at least one communication element, means configured to receive and process a multi-connectivity control indication for controlling the second communication network control element or function to limit a rate of data forwarded by the second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the second communication network control element or function from at least one communication element in the multi-connectivity communication, and means configured to adjust a rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication. Furthermore, according to some other examples of embodiments, the above defined apparatus may further comprise means for conducting at least one of the processing defined in the above described methods, for example a method according that described in connection with Fig 4.

It should be appreciated that

- an access technology via which traffic is transferred to and from an entity in the communication network may be any suitable present or future technology, such as WLAN (Wireless Local Access Network), WiMAX (Worldwide Interoperability for Microwave Access), LTE, LTE-A, 5G, Bluetooth, Infrared, and the like may be used; additionally, embodiments may also apply wired technologies, e.g. IP based access technologies like cable networks or fixed lines.

- embodiments suitable to be implemented as software code or portions of it and being run using a processor or processing function are software code independent and can be specified using any known or future developed programming language, such as a high- level programming language, such as objective-C, C, C++, C#, Java, Python, Javascript, other scripting languages etc., or a low-level programming language, such as a machine language, or an assembler.

- implementation of embodiments is hardware independent and may be implemented using any known or future developed hardware technology or any hybrids of these, such as a microprocessor or CPU (Central Processing Unit), MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), and/or TTL (Transistor-Transistor Logic).

- embodiments may be implemented as individual devices, apparatuses, units, means or functions, or in a distributed fashion, for example, one or more processors or processing functions may be used or shared in the processing, or one or more processing sections or processing portions may be used and shared in the processing, wherein one physical processor or more than one physical processor may be used for implementing one or more processing portions dedicated to specific processing as described,

- an apparatus may be implemented by a semiconductor chip, a chipset, or a (hardware) module including such chip or chipset;

- embodiments may also be implemented as any combination of hardware and software, such as ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field- programmable Gate Arrays) or CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components.

- embodiments may also be implemented as computer program products, including a computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to execute a process as described in embodiments, wherein the computer usable medium may be a non-transitory medium.

Although the present invention has been described herein before with reference to particular embodiments thereof, the present invention is not limited thereto and various modifications can be made thereto.

Claims

1 . An apparatus comprising

at least one processing circuitry, and

at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least:

to conduct a communication procedure for participating in a multi-connectivity communication of at least one communication element,

to prepare a multi-connectivity control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication to limit a rate of data forwarded by the at least one second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi- connectivity communication, and

to cause sending the multi-connectivity control indication to the at least one second communication network control element or function.

2. The apparatus according to claim 1 , wherein the at least one memory and the instructions are further configured to, with the at least one processing circuitry, cause the apparatus at least:

to determine an available capacity in the first communication network control element or function for processing uplink data received by the at least one second communication network control element or function and to be processed by the first communication network control element or function in the multi-connectivity communication, wherein for determining the available capacity, at least one of a current processing load of the first communication network control element or function and an actual rate of data being forwarded by the at least one second communication network element or function is considered.

3. The apparatus according to any of claims 1 and 2, wherein the multi-connectivity control indication comprises one of a limitation indication providing each of the at least one second communication network control element or function with a limit value for the rate of data forwarded by the at least one second communication network control element or function to the first communication network control element or function, and

a grant indication that allows the at least one second communication network control element or function to forward an indicated maximum amount of data to the first communication network control element or function.

4. The apparatus according to any of claims 1 to 3, wherein the data contained in the all uplink data received by the at least one second communication network control element or function from the at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication are data forwarded on a specific bearer type including at least one of a switched bearer and a split bearer in the multi-connectivity communication.

5. The apparatus according to claim 4, wherein the multi-connectivity control indication is related exclusively to data forwarded by the at least one second communication network control element or function via the specific bearer type.

6. The apparatus according to any of claims 1 to 5, wherein the multi-connectivity communication is a dual connectivity communication, wherein the first communication network control element or function is a master communication network control element or function and the second communication network control element or function is a secondary communication network control element or function of the dual connectivity communication, wherein the multi-connectivity control indication is prepared for a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type.

7. The apparatus according to any of claims 1 to 6, wherein the first communication network control element or function is configured to control a different type of communication network than the at least one second communication network control element or function, wherein the communication element includes a user equipment or terminal device configured to communicate in each of the communication networks controlled by the first communication network control element or function and the at least one second communication network control element or function in the multi-connectivity communication.

8. The apparatus according to any of claims 1 to 7, wherein t e apparatus is included in the first communication network control element or function.

9. A method comprising

conducting a communication procedure for participating in a multi-connectivity communication of at least one communication element,

preparing a multi-connectivity control indication for controlling at least one second communication network control element or function participating in the multi-connectivity communication to limit a rate of data forwarded by the at least one second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the at least one second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi- connectivity communication, and

causing sending the multi-connectivity control indication to the at least one second communication network control element or function.

10. The method according to claim 9, further comprising

determining an available capacity in the first communication network control element or function for processing uplink data received by the at least one second communication network control element or function and to be processed by the first communication network control element or function in the multi-connectivity communication,

wherein for determining the available capacity, at least one of a current processing load of the first communication network control element or function and an actual rate of data being forwarded by the at least one second communication network element or function is considered.

1 1 . The method according to any of claims 9 and 10, wherein the multi-connectivity control indication comprises one of

a limitation indication providing each of the at least one second communication network control element or function with a limit value for the rate of data forwarded by the at least one second communication network control element or function to the first communication network control element or function, and

12. The method according to any of claims 9 to 1 1 , wherein the data contained in the all uplink data received by the at least one second communication network control element or function from the at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication are data forwarded on a specific bearer type including at least one of a switched bearer and a split bearer in the multi-connectivity communication.

13. The method according to claim 12, wherein the multi-connectivity control indication is related exclusively to data forwarded by the at least one second communication network control element or function via the specific bearer type.

14. The method according to any of claims 9 to 13, wherein the multi-connectivity communication is a dual connectivity communication, wherein the first communication network control element or function is a master communication network control element or function and the second communication network control element or function is a secondary communication network control element or function of the dual connectivity communication, wherein the multi-connectivity control indication is prepared for a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type.

15. The method according to any of claims 9 to 14, wherein the first communication network control element or function is configured to control a different type of communication network than the at least one second communication network control element or function, wherein the communication element includes a user equipment or terminal device configured to communicate in each of the communication networks controlled by the first communication network control element or function and the at least one second communication network control element or function in the multi-connectivity communication.

16. The method according to any of claims 9 to 15,

wherein the method is implemented in the first communication network control element or function.

17. An apparatus comprising

at least one processing circuitry, and

at least one memory for storing instructions to be executed by the processing circuitry, wherein t e at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least:

to conduct a communication procedure for participating, as a second communication network control element or function, in a multi-connectivity communication of at least one communication element,

to receive and process a multi-connectivity control indication for controlling the second communication network control element or function to limit a rate of data forwarded by the second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the second communication network control element or function from at least one communication element in the multi- connectivity communication, and

to adjust a rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication.

18. The apparatus according to claim 17, wherein the multi-connectivity control indication comprises one of

a limitation indication providing a limit value for the rate of data forwarded by the second communication network control element or function to the first communication network control element or function, and

a grant indication that allows the second communication network control element or function to forward an indicated maximum amount of data to the first communication network control element or function.

19. The apparatus according to any of claims 17 and 18, wherein data contained in the all uplink data received by the second communication network control element or function from the at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication are data forwarded on a specific bearer type including at least one of a switched bearer and a split bearer in the multi-connectivity communication.

20. The apparatus according to claim 19, wherein the multi-connectivity control indication is related exclusively to data forwarded by the second communication network control element or function via the specific bearer type.

21 . The apparatus according to any of claims 17 to 20, wherein the at least one memory and the instructions are further configured to, with the at least one processing circuitry, cause the apparatus at least

when adjusting of the rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication, to limit a rate of scheduling of bearers transporting the data being forwarded.

22. The apparatus according to any of claims 17 to 21 , wherein the multi-connectivity communication is a dual connectivity communication, wherein the first communication network control element or function is a master communication network control element or function and the second communication network control element or function is a secondary communication network control element or function of the dual connectivity communication, wherein the multi-connectivity control indication is related to a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type.

23. The apparatus according to any of claims 17 to 22, wherein the first communication network control element or function is configured to control a different type of communication network than the second communication network control element or function,

wherein the communication element includes a user equipment or terminal device configured to communicate in each of the communication networks controlled by the first communication network control element or function and the second communication network control element or function in the multi-connectivity communication.

24. A method comprising

conducting a communication procedure for participating, as a second communication network control element or function, in a multi-connectivity communication of at least one communication element,

receiving and processing a multi-connectivity control indication for controlling the second communication network control element or function to limit a rate of data forwarded by the second communication network control element or function to a first communication network control element or function participating in the multi-connectivity communication, wherein the data being forwarded contain all uplink data received by the second communication network control element or function from at least one communication element in the multi-connectivity communication, and adjusting a rate of data forwarded to t e first communication network control element or function on the basis of the multi-connectivity control indication.

25. The method according to claim 24, wherein the multi-connectivity control indication comprises one of

26. The method according to any of claims 24 and 25, wherein data contained in the all uplink data received by the second communication network control element or function from at least one communication element and to be processed by the first communication network control element or function in the multi-connectivity communication are data forwarded on a specific bearer type including at least one of a switched bearer and a split bearer in the multi-connectivity communication.

27. The method according to claim 26, wherein the multi-connectivity control indication is related exclusively to data forwarded by the second communication network control element or function via the specific bearer type.

28. The method according to any of claims 24 to 27, wherein the adjusting of the rate of data forwarded to the first communication network control element or function on the basis of the multi-connectivity control indication comprises limiting a rate of scheduling of bearers transporting the data being forwarded.

29. The method according to any of claims 24 to 28, wherein the multi-connectivity communication is a dual connectivity communication, wherein the first communication network control element or function is a master communication network control element or function and the second communication network control element or function is a secondary communication network control element or function of the dual connectivity communication, wherein the multi-connectivity control indication is related to a specific pair of the first communication network control element or function and the second communication network control element or function cooperating on a specific bearer type.

30. The method according to any of claims 24 to 29, wherein the first communication network control element or function is configured to control a different type of communication network than the second communication network control element or function,

31 . A computer program product for a computer, including software code portions for performing the steps of any of claims 9 to 15 or any of claims 24 to 30 when said product is run on the computer.

32. The computer program product according to claim 31 , wherein

the computer program product includes a computer-readable medium on which said software code portions are stored, and/or

the computer program product is directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.