WO2019154499A1

WO2019154499A1 - Optimized session establishment for user plane tunneling

Info

Publication number: WO2019154499A1
Application number: PCT/EP2018/053170
Authority: WO
Inventors: Harri POVELAINEN; Juha-Matti TILLI; Mikko Tirronen; Sami Petteri HEINONEN; Risto Juhani TEITTINEN; Mika Tanskanen
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2018-02-08
Filing date: 2018-02-08
Publication date: 2019-08-15

Abstract

There are provided measures for enabling/realizing optimized session establishment for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane. Such measures exemplarily comprise that, at the control plane, creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint is initiated, access network tunnel information regarding the access network tunnel endpoint is obtained, and a configuration request for configuration for the session with the access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint is issued, and, at the user plane, configuration for the session is performed in response to the configuration request by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

Description

Title

Optim ized session establishm ent for user plane tunneling Field

The present disclosure relates to optim ized session establishm ent for user plane tunneling. More specifically, the present invention relates to m easures (including m ethods, apparatuses (i.e. devices and/or functions) and computer program products) for enabling/realizing optim ized session establishm ent for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane.

Background

I n modern (wireless/ cellular) com m unication systems, the interaction between various network elem ents, entities or functions is handled via sessions there-between. Accordingly, appropriate session m anagem ent (including session establishm ent and/or modification) is a vital issue in terms of efficiency and capacity considerations in such systems. Session establishm ent and/or modification between various network elem ents, entities or functions shall thus be as sim ple as possible so as to produce low signaling load and require few tim e in order to enable support of large num bers and amounts of com m unications, e.g. network de-/registering of large num bers of UEs.

I n a system architecture based on the principle of separation/split of control plane and user plane (e.g. 3GPP 5G/ NR or LTE CUPS systems) , user plane tunneling is applied via a tunnel between network elem ents, entities or functions on the user plane, while the session for such user plane tunneling is m anaged by network elem ents, entities or functions on the control plane.

For exam ple, under current 3GPP 5G/ NR standardization, session establishm ent ( including initial session establishm ent and subsequent modification of a previously established session) of a PDU session for a GTP tunnel between the (R)AN and the UPF, i.e. a N3 tunnel on the user plane, is managed by the SMF on the control plane.

Figure 1 shows a signaling diagram illustrating an example of a conventional PDU session establishment procedure under current 3GPP 5G/NR standardization. The signaling diagram of Figure 1 corresponds to Fig. 4.3.2.2.1-1 in 3GPP TS 23.502 V.1.2.0, and the presently relevant part thereof (steps 9 through 15) is enclosed by a box of a chain-dotted line for illustrative purposes.

As evident from Figure 1, the SMF first configures the UPF by way of a N4 Session Establishment/Modification Request and Response exchange (of. S9a/S9b). In this configuration, the UPF, representing the CN tunnel endpoint, is configured with CN tunnel information, e.g. the TEI D for the CN tunnel endpoint of the GTP tunnel (which is allocated by the SMF). Then, the SMF configures the (R)AN, representing the (R)AN tunnel endpoint, via the AMF, by way of a N2 PDU Session Request and Response exchange (of. S11/S13). In response thereto, the SMF receives (R)AN tunnel information (of. S14). Thereupon, the SMF then configures the UPF by way of another N4 Session Establishment/Modification Request and Response exchange (of. S15a/S15b). In this configuration, the UPF, representing the CN tunnel endpoint, is configured with the (R)AN tunnel information, e.g. the TEID for the (R)AN tunnel endpoint of the GTP tunnel (which is previously received from the (R)AN via the AMF).

Accordingly, two signal/message exchanges are required between the SMF and the UPF, via a N4 session there-between, for session establishment of a PDU session for a GTP tunnel. Between these two signal/message exchanges, it is required to retrieve (R)AN tunnel information which is necessary for completely configuring the UPF for the GTP tunnel.

While the above is exemplified for a current 3GPP 5G/NR system for illustrative purposes, similar procedures are also applied in other current systems. For example, a comparable signaling procedure is used in LTE for Bearer and Context Creation via the S11 interface between the MME and the SGW (SGW-C) , and is thus equally required for session establishm ent for user plane tunneling via the S12 interface between the E- UTRAN and the SGW (SGW- U) .

As evident from the above description of conventional procedures, there is room for im provem ent in terms of reducing signaling load and required tim e in session establishm ent for user plane tunneling.

Accordingly, there is a desire for enabling/ realizing optim ized session establishm ent for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane.

Sum m ary

Various exem plifying em bodim ents of the present invention aim at addressing at least part of the above issues and/or problems and drawbacks.

Various aspects of exem plifying em bodim ents of the present invention are set out in the appended claims.

According to an example aspect of the present invention, there is provided a m ethod com prising initiating creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network elem ent, obtaining access network tunnel inform ation regarding the access network tunnel endpoint, and issuing a configuration request for configuration of a core network elem ent for the session with the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint.

According to an example aspect of the present invention, there is provided a m ethod com prising capturing a configuration request for configuration of a core network elem ent for a session, which is a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint, with access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint, and performing configuration for the session by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

According to an example aspect of the present invention, there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to perform at least the following: initiating creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network element, obtaining access network tunnel information regarding the access network tunnel endpoint, and issuing a configuration request for configuration of a core network element for the session with the access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint.

According to an example aspect of the present invention, there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to perform at least the following: capturing a configuration request for configuration of a core network element for a session, which is a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint, with access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint, and performing configuration for the session by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

According to an example aspect of the present invention, there is provided an apparatus comprising means for initiating creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network element, means for obtaining access network tunnel information regarding the access network tunnel endpoint, and means for issuing a configuration request for configuration of a core network element for the session with the access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint.

According to an example aspect of the present invention, there is provided an apparatus comprising means for capturing a configuration request for configuration of a core network element for a session, which is a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint, with access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint, and means for performing configuration for the session by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

According to an example aspect of the present invention, there is provided a computer program product comprising (computer-executable) computer program code which, when the program code is executed (or run) on a computer or the program is run on a computer (e.g. a computer of an apparatus according to any one of the aforementioned apparatus-related example aspects of the present invention), is configured to cause the computer to carry out the method according to any one of the aforementioned method-related example aspects of the present invention.

The computer program product may comprise or may be embodied as a (tangible/non-transitory) computer-readable (storage) medium or the like, on which the computer-executable computer program code is stored, and/or the program is directly loadable into an internal memory of the computer or a processor thereof.

Further developments and/or modifications of the aforementioned exemplary aspects of the present invention are set out in the following. By way of exemplifying embodiments of the present invention, optimized session establishment for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane, can be enabled/realized. Thereby, conventional procedures can be improved in terms of reducing signaling load and required time in session establishment for user plane tunneling.

Brief description of the drawings

In the following, the present invention will be described in greater detail by way of non-limiting examples with reference to the accompanying drawings, in which

Figure 1 shows a signaling diagram illustrating an example of a conventional PDU session establishment procedure under current 3GPP 5G/NR standardization.

Figure 2 shows a flow diagram illustrating an example of a procedure according to exemplifying embodiments of the present invention,

Figure 3 shows a flowchart illustrating an example of a method, operable on the control plane, according to exemplifying embodiments of the present invention,

Figure 4 shows a flowchart illustrating an example of a method, operable on the user plane, according to exemplifying embodiments of the present invention,

Figure 5 shows a signaling diagram illustrating an example of a PDU session establishment procedure for a 3GPP 5G/NR system according to exemplifying embodiments of the present invention, Figure 6 shows a schematic diagram illustrating an example of a structure of apparatuses according to exemplifying embodiments of the present invention, and

Figure 7 shows a schematic diagram illustrating another example of a functional structure of apparatuses according to exemplifying embodiments of the present invention.

Detailed description

The present disclosure is described herein with reference to particular non limiting examples and to what are presently considered to be conceivable embodiments of the present invention. A person skilled in the art will appreciate that the present invention is by no means limited to these examples and embodiments, and may be more broadly applied.

It is to be noted that the following description of the present invention and its embodiments mainly refers to specifications being used as non-limiting examples for certain exemplifying network configurations and system deployments. Namely, the present invention and its embodiments are mainly described in relation to 3GPP specifications, specially referring to 5G/NR standardization (e.g. Release-15), being used as non-limiting examples. As such, the description of exemplifying embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples and embodiments, and does naturally not limit the invention in any way. Rather, any other system configuration or deployment may equally be utilized as long as complying with what is described herein and/or exemplifying embodiments described herein are applicable to it. hereinafter, various exemplifying embodiments and implementations of the present invention and its aspects are described using several variants and/or alternatives. It is generally to be noted that, according to certain needs and constraints, all of the described variants and/or alternatives may be provided alone or in any conceivable combination (also including combinations of individual features of the various variants and/or alternatives). In this description, the words “comprising” and “including” should be understood as not limiting the described exemplifying embodiments and implementations to consist of only those features that have been mentioned, and such exemplifying embodiments and implementations may also contain features, structures, units, modules etc. that have not been specifically mentioned.

In the drawings, it is to be noted that lines/arrows interconnecting individual blocks or entities are generally meant to illustrate an operational coupling there-between, which may be a physical and/or logical coupling, which on the one hand is implementation-independent (e.g. wired or wireless) and on the other hand may also comprise an arbitrary number of intermediary functional blocks or entities not shown.

According to exemplifying embodiments of the present invention, in general terms, there are provided measures (including methods, apparatuses (i.e. devices and/or functions) and computer program products) for enabling/realizing optimized session establishment for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane.

Figure 2 shows a flow diagram illustrating an example of a procedure according to exemplifying embodiments of the present invention. The procedure of Figure 2 is operable in any kind of communication system, particularly in a system architecture based on the principle of separation/split of control plane and user plane (e.g. 3GPP 5G/NR or LTE CUPS systems). In Figure 2, CP represents a network element, entity or function on the control plane, and UP represents a network element, entity or function on the user plane, which represents the core network tunnel endpoint for the user plane tunneling to be established.

As shown in Figure 2, a procedure according to exemplifying embodiments of the present invention may comprise the following operations. I n operation 1 , the CP initiates creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network elem ent, entity or function (on the user plane) , representing the access network tunnel endpoint for the user plane tunneling to be established. This m ay be realized by transm ission of a corresponding m essage to the access network elem ent, entity or function . I n operation 2, the CP obtains access network tunnel inform ation regarding the access network tunnel endpoint. This m ay be realized by reception of a corresponding m essage from the access network elem ent, entity or function, and analysis (and processing) of the contents thereof.

I n operation 3, the CP issues a configuration request for configuration for the session with the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint is issued. As indicated by a dashed arrow, the thus issued configuration request is transm itted from the CP and received by the UP.

I n operation 4, the UP captures the configuration request for the session , as issued by the CP accordingly. I n operation 4, the UP performs configuration for the session in response to the configuration request by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint. As indicated by a dashed arrow, a configuration response m ay be transm itted from the UP and received by the CP as a confirm ation of success of the requested session configuration at the UP.

I n view thereof, the CP first initiates creation of the session for user plane tunneling, and then configures the UP with both tunnel endpoints of a tunnel for the user plane tunneling by way of a single signal/ m essage exchange. Nam ely, both of the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint, which are required for completely configuring the UP for the tunnel, are provided at once. Figure 3 shows a flowchart illustrating an example of a method, operable on the control plane, according to exemplifying embodiments of the present invention. The method of Figure 3 is operable at or by a network element, entity or function on the control plane, such as the CP according to Figure 2, e.g. SMF of a 5G/NR system, SGW-C of a LTE CUPS system, or the like.

As shown in Figure 3, a method according to exemplifying embodiments of the present invention comprises an operation (S120) of initiating creation of a session for user plane tunneling, like operation 1 in the procedure of Figure 2, an operation (S130) of obtaining access network tunnel information, like operation 2 in the procedure of Figure 2, an operation (S140) of issuing a configuration request for configuration of a core network element for the session, like operation 3 in the procedure of Figure 2.

As shown by dashed lines in Figure 3, a method according to exemplifying embodiments of the present invention may also comprise an operation (S110) of allocating the core network tunnel information regarding the core network tunnel endpoint. The thus allocated core network tunnel information may then be used for initiating session creation at the access network element (i.e. S120) and in the configuration request for configuration of the core network element (i.e. S140).

Figure 4 shows a flowchart illustrating an example of a method, operable on the user plane, according to exemplifying embodiments of the present invention. The method of Figure 4 is operable at or by a network element, entity or function on the user plane, such as the UP according to Figure 2, e.g. UPF of a 5G/NR system, SGW-U of a LTE CUPS system, or the like. Specifically, the method of Figure 4 is operable at or by a network element, entity or function which represents the core network tunnel endpoint for the user plane tunneling to be established.

As shown in Figure 4, a method according to exemplifying embodiments of the present invention comprises an operation (S230) of capturing a configuration request for configuration of a core network element for a session, like operation 4 in the procedure of Figure 2, and an operation (S240) of perform ing configuration for the session by creating a context for the session, like operation 5 in the procedure of Figure 2.

As shown by dashed lines in Figure 4, a m ethod according to exem plifying em bodim ents of the present invention m ay also com prise an operation (S21 0) of detecting reception of uplink user plane data before the context for the session is created, an operation (S220) of creating a dum my context for buffering the received uplink user plane data, and an operation (S250) of forwarding the buffered uplink user plane data within the session when the context for the session is created.

While em bodim ents of the present invention are generally applicable in any com m unication system (architecture) in which the interaction between various network elem ents, entities or functions is handled via sessions there-between, particularly any system architecture based on the principle of separation/split of control plane and user plane, a non- lim iting example regarding the applicability of embodim ents of the present invention for a 3GPP 5G/NR system is outlined below.

Nam ely, an exem plary use case of UE- requested session establishm ent of a PDU session for a GTP tunnel between the ( R)AN and the UPF, i.e. a N3 tunnel on the user plane, which is m anaged by the SMF on the control plane, is described.

Figure 5 shows a signaling diagram illustrating an exam ple of a PDU session establishm ent procedure for a 3GPP 5G/NR system according to exemplifying em bodim ents of the present invention . The presently relevant part thereof (steps 9 to 1 4) is enclosed by a box of a chain-dotted line for illustrative purposes.

While in the following only those functionalities/operations of the procedure of Figure 5 are described, which pertain to em bodim ents of the present invention , reference is m ade to 3GPP TS 23.502 V.1 .2.0, section 4.3.2.2.1 , for an elaborate explanation of the overall procedure. The thus given detailed explanation of Fig. 4.3.2.2.1 - 1 in 3GPP TS 23.502 V.1 .2.0 basically applies here as well, and is thus incorporated herein by reference. Particularly, the functionalities/operations of steps S1 to S8, S10 to S14 and S16 to S19 in Fig. 4.3.2.2.1-1 in 3GPP TS 23.502 V.1.2.0 basically correspond to the functionalities/operations of steps S1 to S8, S9 to S13 and S15 to S18 in present Figure 5, respectively.

For the procedure of Figure 5, it is assumed that the SMF allocates CN tunnel information, e.g. the TEID for the CN tunnel endpoint of the GTP tunnel. That is, the SMF (not the UPF) is in charge of TEID allocation according to exemplifying embodiments of the present invention.

As evident from Figure 5, the SMF first configures the (R)AN, representing the (R)AN tunnel endpoint, via the AMF, by way of a N2 PDU Session Request and Response exchange (cf. S10/S12). In response thereto, the SMF receives (R)AN tunnel information (cf. S13). Thereupon, the SMF configures the UPF by way of a N4 Session Establishment/Modification Request and Response exchange (cf. S14a/S14b). In this configuration, the UPF, representing the CN tunnel endpoint, is configured with CN tunnel information, e.g. the TEID for the CN tunnel endpoint of the GTP tunnel (which is allocated by the SMF) as well as with the (R)AN tunnel information, e.g. the TEID for the (R)AN tunnel endpoint of the GTP tunnel (which is previously received from the (R)AN via the AMF).

In configuring the UPF, the UPF creates a PDU context for the PDU session based on the CN tunnel information, e.g. the TEID for the CN tunnel endpoint of the GTP tunnel, and the (R)AN tunnel information, e.g. the TEID for the (R)AN tunnel endpoint of the GTP tunnel, as received in the configuration request.

Accordingly, a single signal/message exchange between the SMF and the UPF, via a N4 session there-between, is sufficient for session establishment of a PDU session for a GTP tunnel. This single signal/message exchange can take place when the required tunnel information regarding both tunnel endpoints is available, i.e. upon retrieval of the (R)AN tunnel information. As indicated in Figure 5, the UPF can have a functionality of UL data buffering, which basically corresponds to operations S210, S220 and S30 in Figure 4.

Such UL data buffering is effective for coping with a situation in which the UE starts sending UL data immediately after the PDU session has been created in the (R)AN but the GTP tunnel has not yet been finally established, i.e. configured in the UPF. In such situation, the UPF cannot forward the received UL data until the GTP tunnel is configured in the UPF, and thus buffers the received UL data until it can be forwarded. So, the received UL data will be buffered at the UPF.

As the remaining signaling until the point where the GTP tunnel is configured in the UPF normally finishes quickly enough, the buffering of the UL data at the UPF should not become a problem anyway.

Accordingly, the UPF has a buffer for first UL data because first UL data can be sent by the UE and the RAN immediately after creation of the PDU session there. It is to be noted that first UL data already contains the correct receiver TEID, as the SMF is the component allocating the TEID. When receiving first UL data, the UPF does not yet have the tunnel with the particular TEID configured. Thus, when receiving first UL data, the UPF creates a dummy context and stores the received first UL data there.

The dummy context may have a timeout (e.g. to maintain it for only 1 second) that may be configurable (different operators may want different timeouts). The buffer size (or, buffer capacity) for buffering first UL data may be limited to a certain amount of data, e.g. a certain number of packets or bytes, and the limit may be configurable (different operators may want different limits). In case a buffer timeout occurs (namely, first UL data are received since or buffered for a time according to the configured timeout, while the session is still not created such that the first UL data can still not be forwarded) or a maximum amount of first UL data, e.g. a maximum number of buffered packets or bytes, is reached (in the buffer such that a buffer size/ capacity overflow is about to occur), an error indication, such as an optional GTP Error I ndication, could be given to the sender ( i.e. the RAN) .

When com paring (the indicated relevant parts of) the PDU session establishm ent procedure for a 5G/ NR system according to exem plifying embodim ents of the present invention , as illustrated in Figure 5, and the conventional PDU session establishm ent procedure under current 3GPP 5G/ NR standardization, the difference there-between becom es evident. Nam ely, the signal/ m essage exchange of S9a and S9b in Figure 1 can be saved/om itted in the procedure of Figure 5, as the signal/m essage exchange of S1 4a and S14b in Figure 5 com bines/m erges the functionality of both signal/m essage exchanges of S9a/S9b and S1 5a/S1 5b in Figure 1 .

Thereby, signaling between SMF and UPF for PDU session establishment is sim plified. The amount of signaling between SMF and UPF, which is needed for PDU session establishm ent, can be halved ( i.e. one out of two signal/m essage exchanges can be om itted) . I n addition to the thus resulting lower signaling load, the required amount of tim e for PDU session establishm ent can also be reduced. This results in a considerable benefit, not only but especially in the context of a service request after the UE has been idle.

The thus achievable benefit is particularly effective, as signaling load can be taken from the core network and it is not required to increase signaling load in the access network instead. I n this regard, it is to be noted that usually the core network has higher signaling load than the access network, since fewer nodes are present in the core network as com pared with the access network. So, the saving of one signal/ m essage exchange in the core network is beneficially achieved in that part of the overall system ( i.e. the core network) , which is typically subjected to the highest load. Further, it is to be noted that replacing signaling load in the core network by signaling load in the access network (shifting signaling load from the core network to the access network) , as a potentially conceivable alternative to the above- described technique, would not be beneficial. This is essentially because, despite being subjected to lower signaling load, the access network is typically subjected to higher latency, and it is not beneficial to have an additional signal/ message exchange (shifted from the core network to the access network) in a high- latency environm ent.

Although such use case is not depicted, it is to be noted that em bodim ents of the present invention are equally applicable in a LTE CUPS system . For exam ple, a com parable signaling procedure as explained above can be used in LTE for Bearer and Context Creation via the S1 1 interface between the MME and the SGW (SGW-C) , and is thus equally required for session establishm ent for user plane tunneling via the S12 interface between the E- UTRAN and the SGW (SGW- U) .

For such use case, the above description regarding Figure 5 equally applies, for exam ple, if replacing SMF by SGW-C, replacing UPF by SGW- U, and replacing ( R) AN by E- UTRAN, as well as using corresponding signals/m essages being defined for the LTE CUPS system .

By virtue of exem plifying embodim ents of the present invention, as evident from the above, optim ized session establishm ent for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane, can be enabled/ realized. Thereby, im provem ent can be achieved in terms of reducing signaling load and required tim e in session establishm ent for user plane tunneling.

I n a nutshell, em bodim ents of the present invention provide for optim ized session establishm ent for user plane tunneling, e.g. in a 5G/ NR system where first ( R)AN configuration is finalized by SMF/AMF and then - with a single signal/m essage exchange between SMF and UPF - the UPF side (CN tunnel endpoint) is configured, or in a LTE CUPS system where first E- UTRAN configuration is finalized by MME/SGW-C and then - with a single signal/ m essage exchange between SGW-C and SGW- U - the SGW side (CN tunnel endpoint) is configured. The above-described m ethods, procedures and functions m ay be im plem ented by respective functional elem ents, entities, modules, units, processors, or the like, as described below.

While in the foregoing exemplifying em bodim ents of the present invention are described m ainly with reference to m ethods, procedures and functions, corresponding exem plifying em bodim ents of the present invention also cover respective apparatuses, entities, modules, units, network nodes and/or systems, including both software and/or hardware thereof .

Respective exem plifying em bodim ents of the present invention are described below referring to Figures 6 and 7, while for the sake of brevity reference is m ade to the detailed description of respective corresponding configurations/ setups, schem es, m ethods and functionality, principles and operations according to Figures 2 to 5.

I n Figures 6 and 7, the blocks are basically configured to perform respective m ethods, procedures and/or functions as described above. The entirety of blocks are basically configured to perform the m ethods, procedures and/or functions as described above, respectively. With respect to Figures 6 and 7, it is to be noted that the individual blocks are m eant to illustrate respective functional blocks im plem enting a respective function, process or procedure, respectively. Such functional blocks are im plem entation-independent, i.e. m ay be im plem ented by m eans of any kind of hardware or software or combination thereof, respectively.

Further, in Figures 6 and 7, only those functional blocks are illustrated, which relate to any one of the above-described m ethods, procedures and/or functions. A skilled person will acknowledge the presence of any other conventional functional blocks required for an operation of respective structural arrangem ents, such as e.g. a power supply, a central processing unit, respective m emories or the like. Among others, one or more memories are provided for storing programs or program instructions for controlling or enabling the individual functional entities or any combination thereof to operate as described herein in relation to exemplifying em bodim ents. Figure 6 shows a schematic diagram illustrating an example of a structure of apparatuses according to exemplifying embodiments of the present invention. Herein , an apparatus can represent a device or a function, i.e. a structural device implementing a specific network element, entity or function or the functionality thereof as such.

As indicated in Figure 6, according to exemplifying embodiments of the present invention, an apparatus 600 may comprise at least one processor 610 and at least one memory 620 (and possibly also at least one interface 630), which may be operationally connected or coupled, for example by a bus 640 or the like, respectively.

The processor 610 and/or the interface 630 of the apparatus 600 may also include a modem or the like to facilitate communication over a (hardwire or wireless) link, respectively. The interface 630 of the apparatus 600 may include a suitable transmitter, receiver or transceiver connected or coupled to one or more antennas, antenna units, such as antenna arrays or communication facilities or means for (hardwire or wireless) communications with the linked, coupled or connected device(s), respectively. The interface 630 of the apparatus 600 is generally configured to communicate with at least one other apparatus, device, node or entity (in particular, the interface thereof).

The memory 620 of the apparatus 600 may represent a (non- transitory/tangible) storage medium and store respective software, programs, program products, macros or applets, etc. or parts of them, which may be assumed to comprise program instructions or computer program code that, when executed by the respective processor, enables the respective electronic device or apparatus to operate in accordance with the exemplifying embodiments of the present invention. Further, the memory 620 of the apparatus 600 may (comprise a database to) store any data, information, or the like, which is used in the operation of the apparatus. For example, the memory 620 may represent or implement a buffer for buffering UL data, as described above. In general terms, respective apparatuses (and/or parts thereof) may represent means for performing respective operations and/or exhibiting respective functionalities, and/or the respective devices (and/or parts thereof) may have functions for performing respective operations and/or exhibiting respective functionalities.

In view of the above, the thus illustrated apparatus 600 is suitable for use in practicing one or more of the exemplifying embodiments of the present invention, as described herein.

When in the subsequent description it is stated that the processor (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that a (i.e. at least one) processor or corresponding circuitry, potentially in cooperation with a computer program code stored in the memory of the respective apparatus or otherwise available (it should be appreciated that the memory may also be an external memory or provided/realized by a cloud service or the like), is configured to cause the apparatus to perform at least the thus mentioned function.

According to exemplifying embodiments of the present invention, the thus illustrated apparatus 600 may represent or realize/embody a (part of a) network element, entity or function on the control plane, i.e. a CP as illustrated in Figure 2. Specifically, the apparatus 600 may for example be a (part of a) a SMF in a 5G/NR system or a SGW-C in a LTE CUPS system in accordance with 3GPP specifications, or the like. Flence, the apparatus 600 may be configured to perform a procedure and/or exhibit a functionality and/or implement a mechanism, as described for CP or SMF, in any one of Figures 2, 3 and 5.

Accordingly, the apparatus 600 may be caused or the apparatus 600 or its at least one processor 610 (possibly together with computer program code stored in its at least one memory 620), in its most basic form, is configured to initiate creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network elem ent, obtain access network tunnel inform ation regarding the access network tunnel endpoint, and issue a configuration request for configuration of a core network elem ent for the session with the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint.

According to exem plifying em bodim ents of the present invention , the thus illustrated apparatus 600 m ay represent or realize/em body a (part of a) network elem ent, entity or function on the control plane, i.e. a UP as illustrated in Figure 2. Specifically, the apparatus 600 m ay for exam ple be a (part of a) a UPF in a 5G/ NR system or a SGW (SGW- U) in a LTE CUPS system in accordance with 3GPP specifications, or the like. Flence, the apparatus 600 m ay be configured to perform a procedure and/or exhibit a functionality and/or im plem ent a m echanism , as described for UP or UPF, in any one of Figures 2, 4 and 5.

Accordingly, the apparatus 600 m ay be caused or the apparatus 600 or its at least one processor 61 0 (possibly together with com puter program code stored in its at least one m emory 620) , in its most basic form , is configured to capture a configuration request for configuration of a core network elem ent for a session , which is a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint, with access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint, and perform configuration for the session by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

As m entioned above, an apparatus according to exem plifying em bodim ents of the present invention m ay be structured by com prising respective units or m eans for perform ing corresponding operations, procedures and/or functions. For exam ple, such units or m eans m ay be im plem ented/realized on the basis of an apparatus structure, as exemplified in Figure 6, i.e. by one or more processors 610, one or more memories 620, one or more interfaces 630, or any combination thereof.

Figure 7 shows a schematic diagram illustrating another example of a functional structure of an apparatus according to exemplifying embodiments of the present invention.

It is to be noted that the individual apparatuses shown in Figure 7 are inherently independent from each other but could be operable to interwork, i.e. exemplifying embodiments of the present invention cover any one of these apparatuses alone or any combination of such apparatuses (including one or more of any one of these apparatuses).

As shown in Figure 7, an apparatus 700 according to exemplifying embodiments of the present invention may represent a (part of a) CP such as e.g. a (part of a) a SMF in a 5G/NR system or a SGW-C in a LTE CUPS system in accordance with 3GPP specifications, or the like. Such apparatus may comprise (at least) a unit or means for initiating creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network element (denoted as session creation initiating unit/means 710), a unit or means for obtaining access network tunnel information regarding the access network tunnel endpoint (denoted as AN tunnel information obtaining unit/means 720), and a unit or means for issuing a configuration request for configuration of a core network element for the session with the access network tunnel information regarding the access network tunnel endpoint and core network tunnel information regarding the core network tunnel endpoint (denoted as configuration request issuing unit/means 730).

As evident from the above, the apparatus 700 may optionally also comprise a unit or means for allocating the core network tunnel information regarding the core network tunnel endpoint (denoted as CN tunnel information allocating unit/means 740). As shown in Figure 7, an apparatus 800 according to exem plifying embodim ents of the present invention m ay represent a (part of a) UP such as e.g. a (part of a) a UPF in a 5G/ NR system or a SGW (SGW- U) in a LTE CUPS system in accordance with 3GPP specifications, or the like. Such apparatus m ay com prise (at least) a unit or m eans for capturing a configuration request for configuration of a core network elem ent for a session, which is a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint, with access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint (denoted as configuration request capturing unit/ m eans 81 0) , and a unit or m eans perform ing configuration for the session by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint (denoted as session configuration perform ing unit/m eans 820) .

As evident from the above, the apparatus 800 m ay optionally also com prise a unit or m eans for buffering uplink data (denoted as UL data buffering unit/ m eans 830) . I n this regard, buffering uplink data m ay com prise detecting reception of uplink user plane data before the context for the session is created, creating a dum my context for buffering the received uplink user plane data, and forwarding the buffered uplink user plane data within the session when the context for the session is created. Further, the dum my context m ay be configured with a tim eout and/or a buffering capacity is configured with a m axim um amount of buffered uplink user plane data, and, in case the tim eout occurs and/or the m axim um amount of buffered uplink user plane data is reached, an error indication m ay be given to a sender of the uplink user plane data.

For further details regarding the operability/functionality of the individual apparatuses (or units/m eans thereof) according to exem plifying em bodim ents of the present invention, reference is m ade to the above description in connection with any one of Figures 2 to 5, respectively. According to exemplifying embodiments of the present invention, any one of the (at least one) processor, the (at least one) memory and the (at least one) interface, as well as any one of the illustrated units/means, may be implemented as individual modules, chips, chipsets, circuitries or the like, or one or more of them can be implemented as a common module, chip, chipset, circuitry or the like, respectively.

According to exemplifying embodiments of the present invention, a system may comprise any conceivable combination of any depicted or described apparatuses and other network elements or functional entities, which are configured to cooperate as described above.

In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device.

Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention. Such software may be software code independent and can be specified using any known or future developed programming language, such as e.g. Java, C+ + , C, and Assembler, as long as the functionality defined by the method steps is preserved. Such hardware may be hardware type independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components. A device/ apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device/ apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor. A device may be regarded as a device/apparatus or as an assembly of more than one device/ apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

Apparatuses and/or units/means or parts thereof can be implemented as individual devices, but this does not exclude that they may be implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof.

The present invention also covers any conceivable combination of method steps and operations described above, and any conceivable combination of nodes, apparatuses, modules or elements described above, as long as the above-described concepts of methodology and structural arrangement are applicable.

In view of the above, there are provided measures for enabling/realizing optimized session establishment for user plane tunneling, particularly in a system architecture based on the principle of separation/split of control plane and user plane. Such measures exemplarily comprise that, at the control plane, creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint is initiated, access network tunnel inform ation regarding the access network tunnel endpoint is obtained, and a configuration request for configuration for the session with the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint is issued, and, at the user plane, configuration for the session is perform ed in response to the configuration request by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

Even though the invention is described above with reference to the exam ples according to the accom panying drawings, it is to be understood that the invention is not restricted thereto. Rather, it is apparent to those skilled in the art that the present invention can be modified in m any ways without departing from the scope of the inventive idea as disclosed herein.

List of acronyms and abbreviations 3GPP 3rd Generation Partnership Project

5G 5th Generation

AMF Access and Mobility Managem ent Function

AN Access Network

CN Core Network

CP Control Plane

CUPS Control User Plane Split

DN Data Network

GPRS General Packet Radio Service

GTP GPRS Tunneling Protocol

I Pv6 I nternet Protocol version 6

LTE Long Term Evolution

MME Mobility Managem ent Entity

NAS Non-Access Stratum

NDP Neighbor Discovery Protocol

NR New Radio PCF Policy Control Function

PDU Protocol Data Unit

RAN Radio Access Network

SGW Serving Gateway

SGW-C Serving Gateway - Control plane

SGW- U Serving Gateway - User plane

SMF Session Managem ent Function

TEI D Tunnel Endpoint I dentifier

UDM Unified Data Managem ent

UE User Equipment

UL Uplink

UP User Plane

UPF User Plane Function

E- UTRAN Evolved Universal Terrestrial Radio Access Network

Claims

1 . A m ethod com prising :

initiating creation of a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint at an access network elem ent,

obtaining access network tunnel inform ation regarding the access network tunnel endpoint, and

issuing a configuration request for configuration of a core network elem ent for the session with the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint.

2. The m ethod according to claim 1 , further com prising :

allocating the core network tunnel inform ation regarding the core network tunnel endpoint,

wherein the allocated core network tunnel inform ation is used for initiating session creation at the access network elem ent and in the configuration request for configuration of the core network elem ent.

3. The m ethod according to claim 1 or 2, wherein

the m ethod is operable at or by a function or entity on the control plane, and

any one of the access and core network elem ents is or com prises a function or entity on the user plane.

4. The m ethod according to any one of claims 1 to 3, wherein

the method is operable at or by a session m anagem ent function.

5. The m ethod according to claim 4, wherein

the access network elem ent is or com prises an access network function or a radio access network function, and/or

the core network elem ent is or com prises a user plane function.

6. The m ethod according to any one of claims 1 to 3, wherein the m ethod is operable at or by a mobility m anagem ent entity.

7. The m ethod according to claim 6, wherein

the access network elem ent is or com prises a radio access entity, and/or

the core network elem ent is or com prises a serving gateway entity.

8. A m ethod com prising :

capturing a configuration request for configuration of a core network elem ent for a session , which is a session for user plane tunneling between an access network tunnel endpoint and a core network tunnel endpoint, with access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint, and

perform ing configuration for the session by creating a context for the session on the basis of the access network tunnel endpoint and the core network tunnel endpoint.

9. The m ethod according to claim 8, further com prising :

detecting reception of uplink user plane data before the context for the session is created,

creating a dum my context for buffering the received uplink user plane data, and

forwarding the buffered uplink user plane data within the session when the context for the session is created.

1 0. The m ethod according to claim 9, wherein

the dum my context is configured with a tim eout and/or a buffering capacity is configured with a m axim um amount of buffered uplink user plane data, and

in case the tim eout occurs and/or the m axim um amount of buffered uplink user plane data is reached, an error indication is given to a sender of the uplink user plane data.

1 1 . The m ethod according to any one of claims 8 to 1 0, wherein the m ethod is operable at or by a function or entity on the user plane, and

12. The m ethod according to any one of claims 8 to 1 1 , wherein

the m ethod is operable at or by a user plane function , and/or the configuration request is received from a session m anagem ent function.

13. The m ethod according to claim 12, wherein

the core network elem ent is or com prises the user plane function.

14. The m ethod according to any one of claims 8 to 1 1 , wherein

the m ethod is operable at or by a serving gateway entity, and/or the configuration request is received from a mobility m anagem ent entity.

1 5. The m ethod according to claim 14, wherein

the access network elem ent is or com prises a radio access entity, and/or

the core network element is or com prises the serving gateway entity.

1 6. An apparatus com prising

at least one processor and at least one m emory including a com puter program code, wherein the at least one m emory and the computer program code are configured, with the at least one processor, to cause the apparatus to perform at least the following:

obtaining access network tunnel inform ation regarding the access network tunnel endpoint, and issuing a configuration request for configuration of a core network elem ent for the session with the access network tunnel inform ation regarding the access network tunnel endpoint and core network tunnel inform ation regarding the core network tunnel endpoint.

1 7. The apparatus according to claim 1 6, wherein the at least one m emory and the computer program code are configured, with the at least one processor, to cause the apparatus to perform :

1 8. The apparatus according to claim 1 6 or 1 7, wherein

the apparatus is operable at or as a function or entity on the control plane, and

1 9. The apparatus according to any one of claims 1 6 to 1 8, wherein

the apparatus is operable at or as a session m anagement function.

20. The apparatus according to claim 1 9, wherein

the core network elem ent is or com prises a user plane function.

21 . The apparatus according to any one of claims 1 6 to 1 8, wherein

the apparatus is operable at or as a mobility m anagem ent entity.

22. The apparatus according to claim 21 , wherein

the access network elem ent is or com prises a radio access entity, and/or

the core network elem ent is or com prises a serving gateway entity.

23. An apparatus com prising

24. The apparatus according to claim 23, wherein the at least one m emory and the computer program code are configured, with the at least one processor, to cause the apparatus to perform :

25. The apparatus according to claim 24, wherein

26. The apparatus according to any one of claims 23 to 25, wherein the apparatus is operable at or as a function or entity on the user plane, and

27. The apparatus according to any one of claims 23 to 26, wherein

the apparatus is operable at or as a user plane function, and/or the configuration request is received from a session m anagem ent function.

28. The apparatus according to claim 27, wherein

the core network elem ent is or com prises the user plane function.

29. The apparatus according to any one of claims 23 to 26, wherein

the apparatus is operable at or by a serving gateway entity, and/or the configuration request is received from a mobility m anagem ent entity.

30. The apparatus according to claim 29, wherein

the access network elem ent is or com prises a radio access entity, and/or

the core network element is or com prises the serving gateway entity.

31 . A com puter program product comprising com puter program code which, when the com puter program code is executed on a com puter, is configured to cause the com puter to carry out the m ethod according to any one of claims 1 to 7 or claims 8 to 1 5.