WO2020177874A1

WO2020177874A1 - Client device, network access node and methods for efficient pdu session establishment

Info

Publication number: WO2020177874A1
Application number: PCT/EP2019/055781
Authority: WO
Inventors: Siva VAKEESAR; Ali HAMIDIAN; Antonio Consoli
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2019-03-07
Filing date: 2019-03-07
Publication date: 2020-09-10

Abstract

The invention relates to efficient session establishment using a pre-session establishment route check procedure. Before establishing a PDU session, a client device (100) provides a pre-PDU session establishment request (502) to a network node (302). The pre-PDU session establishment request (502) comprises a flightpath and a QoS requirement of the PDU session. Based on the pre-PDU session establishment request (502), the network node (302) determines a set of routes associated with the flightpath, where each route in the set of routes is associated with a supported QoS and a route identifier. The network node (302) provides the determined set of routes to the client device (100) in a pre-PDU session establishment response (504). Thus, the client device (100) obtains information about supported QoS along one or more routes associated with the flightpath. Thereby, the client device can pre-check whether a QoS requirement for a PDU session is possible in one or more physical routes between the starting point and the destination point before the PDU session is established. Furthermore, the invention also relates to corresponding methods and a computer program.

Description

CLIENT DEVICE, NETWORK ACCESS NODE AND METHODS FOR EFFICIENT PDU

SESSION ESTABLISHMENT

Technical Field

The invention relates to a client device and a network access node for efficient PDU session establishment using a pre-session establishment route check procedure. Furthermore, the invention also relates to corresponding methods and a computer program.

Background

The need to support predictive quality-of-service (QoS) had recently been felt by different industries and in response the 3GPP specification group SA1 recently agreed on some requirements in this direction. The relevant SA1 requirements were captured in TR 22.886 V16.1.1. Although relevant stage 1 related requirements are captured, 3GPP specifications still focus on describing a variety of reactive behaviour expected on the 5G system (5GS) to deal with in response to change in pre-agreed QoS. This is because although 5GS is reasonably reliable, it is not 100% reliable in terms of ensuring pre-agreed QoS throughout a lifetime of an established session. Under such circumstances, a new type of pro-active behaviour is required in order for the 5GS to alert an application running in a client device to take corrective actions in response to the inability of the network to meet a given pre-agreed QoS.

Summary

An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

The above and further objectives are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

According to a first aspect of the invention, the above mentioned and other objectives are achieved with a client device for a wireless communication system, the client device being configured to

provide a pre-packet data unit, PDU, session establishment request to a network node, wherein the pre-PDU session establishment request comprises a flightpath and a quality-of- service, QoS, requirement of the PDU session;

obtain a pre-PDU session establishment response from the network node, wherein the pre-PDU session establishment response comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS and a route identifier.

The flightpath can in this disclosure comprise information associated with the location of the client device, such as a current location and one or more planned future locations. The set of routes associated with the flightpath can comprise one or more physical routes which the client device can take to get from the current location, i.e. the starting point, to the one or more planned future locations, i.e. the destination points. The client device may report a number of waypoints of the flightpath if such information is available to the client device. Further, the report can also comprise time stamps per waypoint. The flightpath information can be given in coordinate format such as in Cartesian coordinates [x, y, z] or GPS coordinates in terms of latitude, longitude and azimuth angle or altitude.

The set of routes provided by the network node comprises one or more different physical routes between the starting point and the destination point.

An advantage of the client device according to the first aspect is that the client device can precheck whether a QoS requirement for a PDU session is possible in one or more physical routes between the starting point and the destination point before the PDU session is established.

In an implementation form of a client device according to the first aspect, the client device is further configured to

select a route among the set of routes based on its associated supported QoS;

provide a PDU session establishment request to the network node, wherein the PDU session establishment request comprises the route identifier of the selected route.

The selected route can be a single route selected among one or more routes in the set of routes.

An advantage with this implementation form is that the client device can select the most appropriate route among the set of routes. Further, the client device informs the network node about the selected route in the PDU session establishment request message.

In an implementation form of a client device according to the first aspect, the client device is further configured to select the route among the set of routes based on the associated supported QoSs and input.

The input can be input from a user of the client device, i.e. a person using the client device. The input can be provided by the user by conventional user interfaces of the client device, such as touch screen, microphone, keyboard, etc.

An advantage with this implementation form is that user input is considered when selecting the route among the set of routes. Thereby, the wish of the user is considered in the selection process.

In an implementation form of a client device according to the first aspect, provide the pre-PDU session establishment request comprises

provide the pre-PDU session establishment request to the network node via a network access node and an access and mobility management function, AMF.

An advantage with this implementation form is that existing network interfaces can be used instead of introducing new interfaces between the client device and the network node.

In an implementation form of a client device according to the first aspect, the pre-PDU session establishment request is comprised in a radio resource control, RRC, connection setup complete or a RRC connection resume complete to a network access node.

An advantage with this implementation form is that the pre-PDU session establishment request can be encapsulated in an existing RRC message.

establish an RRC connection setup or an RRC connection resume with the network access node prior to providing the pre-PDU session establishment request to the network node.

An advantage with this implementation form is that it ensures that the pre-PDU session establishment request can be encapsulated within existing RRC messages after RRC establishment. In an implementation form of a client device according to the first aspect, obtain the pre-PDU session establishment response comprises

obtain the pre-PDU session establishment response from the network node via an AMF and a network access node.

In an implementation form of a client device according to the first aspect, the pre-PDU session establishment response is comprised in a downlink information transfer from the network access node.

An advantage with this implementation form is that an existing RRC message can be used to encapsulate the pre-PDU session establishment response.

In an implementation form of a client device according to the first aspect, the flightpath comprises a starting point and a destination point.

An advantage with this implementation form is that the network node can check all possible routes between the starting point and the destination point to determine whether the QoS requirement for the PDU session is possible.

According to a second aspect of the invention, the above mentioned and other objectives are achieved with a network node for a wireless communication system, the network node being configured to

obtain a pre-PDU session establishment request from a client device, wherein the pre- PDU session establishment request comprises a flightpath and a QoS requirement of the PDU session;

provide a pre-PDU session establishment response to the client device, wherein the pre- PDU session establishment response comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS.

An advantage with the network node according to the second aspect is that the client device can pre-check whether a QoS requirement for a PDU session is possible in one or more physical routes before the PDU session is established. In an implementation form of a network node according to the second aspect, the network node is further configured to

determine the set of routes based on the pre-PDU session establishment request.

An advantage with this implementation form is that the network node can check future QoS of PDU sessions yet not established along different routes.

In an implementation form of a network node according to the second aspect, the network node is further configured to

determine the set of routes based on the pre-PDU session establishment request and at least one of: spatial location of network access nodes along the set of routes, residual capacities of network access nodes along the set of routes, vehicle traffic information for the set of routes, and weather information for the set of routes.

An advantage with this implementation form is that these parameters are import for determining the set of routes.

In an implementation form of a network node according to the second aspect, obtain the pre- PDU session establishment request comprises

obtain the pre-PDU session establishment request from the client device via a network access node and an AMF.

An advantage with this implementation form is that an existing network interface can be used between the client device and the network node.

In an implementation form of a network access node according to the second aspect, provide the pre-PDU session establishment response comprises

provide the pre-PDU session establishment response to the client device via an AMF and a network access node.

In an implementation form of a network node according to the second aspect, provide the pre- PDU session establishment response comprises obtain a PDU session establishment request from the client device, wherein the PDU session establishment request comprises a route identifier of a selected route of the client device;

determine QoS associated with the established PDU session based on the PDU session establishment request.

An advantage with this implementation form is that the network node can start estimating future QoS along the selected route and trigger in-advance warning to the client device if required. Thereby, the client device can prepare itself for low QoS.

According to a third aspect of the invention, the above mentioned and other objectives are achieved with a method for a client device, the method comprises

providing a pre-packet data unit, PDU, session establishment request to a network node, wherein the pre-PDU session establishment request comprises a flightpath and a quality-of- service, QoS, requirement of the PDU session;

obtaining a pre-PDU session establishment response from the network node, wherein the pre-PDU session establishment response comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS and a route identifier.

The method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the client device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the client device.

The advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the client device according to the first aspect.

According to a fourth aspect of the invention, the above mentioned and other objectives are achieved with a method for a network node, the method comprises

obtaining a pre-PDU session establishment request from a client device, wherein the pre-PDU session establishment request comprises a flightpath and a QoS requirement of the PDU session;

providing a pre-PDU session establishment response to the client device, wherein the pre-PDU session establishment response comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS. The method according to the fourth aspect can be extended into implementation forms corresponding to the implementation forms of the network node according to the second aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the network node.

The advantages of the methods according to the fourth aspect are the same as those for the corresponding implementation forms of the network node according to the second aspect.

The invention also relates to a computer program, characterized in program code, which when run by at least one processor causes said at least one processor to execute any method according to embodiments of the invention. Further, the invention also relates to a computer program product comprising a computer readable medium and said mentioned computer program, wherein said computer program is included in the computer readable medium, and comprises of one or more from the group: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.

Further applications and advantages of the embodiments of the invention will be apparent from the following detailed description.

Brief Description of the Drawings

The appended drawings are intended to clarify and explain different embodiments of the invention, in which:

- Fig. 1 shows a client device according to an example of the invention;

- Fig. 2 shows a method for a client device according to an example of the invention;

- Fig. 3 shows a network node according to an example of the invention;

- Fig. 4 shows a method for a network node according to an example of the invention;

- Fig. 5 shows signalling between a client device and a network node according to an example of the invention:

- Fig. 6 shows signalling between a client device and a network node according to an example of the invention;

- Fig. 7 shows signalling between a client device and a network node according to an example of the invention;

- Fig. 8 shows a flow chart of a method according to an example of the invention; and

- Fig. 9 shows a flow chart of yet another method according to an example of the invention. Detailed Description

In vehicle-to-anything (V2X) applications, the V2X application can decide a suitable route to a destination for the client device. It has been proposed to enable the client device or the V2X application to request QoS predictions not only for a planned route, but for other potential routes as well. This will put the V2X application in a position to evaluate different potential routes to the destination from a QoS perspectives before deciding on the final route to the destination. For example, an autonomous vehicle might prefer to stay on roads that always exhibit satisfying QoS. Thus, QoS has to be predicted in both spatial and time domain, i.e. for both future locations and time instances, for each considered route alternative.

Although the concept of checking alternative routes has been introduced, no concrete mechanisms in terms of how it can be implemented has been disclosed. A user-plane based solution may be envisaged, whereby the V2X application directly enquires a prediction function (PF) to pre-check alternate physical routes in terms of QoS support. However, in order for a vehicle to communicate with the prediction function, a service request has to be made that potentially results in the establishment of at least one data radio bearer. Thus, resulting in unnecessary signalling.

Consequently, the inventors have foreseen a need to be able to check QoS support of potential routes before making a service request, i.e. without having to establish a data radio bearer. The proposed invention therefore introduces a procedure for checking QoS support of potential routes using a control plane solution, thereby e.g. avoiding unnecessary signalling and saving network resources.

Fig. 1 shows a client device 100 according to an embodiment of the invention. In the embodiment shown in Fig. 1 , the client device 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The client device 100 further comprises an antenna or antenna array 1 10 coupled to the transceiver 104, which means that the client device 100 is configured for wireless communications in a wireless communication system.

That the client device 100 is configured to perform certain actions can in this disclosure be understood to mean that the client device 100 comprises suitable means, such as e.g. the processor 102 and the transceiver 104, configured to perform said actions. According to embodiments of the invention the client device 100 is configured to provide a prepacket data unit (PDU) session establishment request 502 to a network node 302. The pre- PDU session establishment request 502 comprises a flightpath and a QoS requirement of the PDU session. The flightpath may comprise information associated with the location of the client device such as e.g. a current location and one or more planned future locations. The client device 100 is further configured to obtain a pre-PDU session establishment response 504 from the network node 302. The pre-PDU session establishment response 504 comprises a set of routes associated with the flightpath and each route in the set of routes is associated with a supported QoS and a route identifier. The set of routes associated with the flightpath may comprise one or more physical routes which the client device can take to get from the current location to the one or more planned future locations.

Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a client device 100, such as the one shown in Fig. 1. The method 200 comprises providing 202 a pre- PDU session establishment request 502 to a network node 302, wherein the pre-PDU session establishment request 502 comprises a flightpath and a QoS requirement of the PDU session The method 200 further comprises obtaining 204 a pre-PDU session establishment response 504 from the network node 302, wherein the pre-PDU session establishment response 504 comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS and a route identifier.

Fig. 3 shows a network node 302 according to an embodiment of the invention. In the embodiment shown in Fig. 3, the network node 302 comprises a processor 312, a transceiver 314 and a memory 316. The processor 312 is coupled to the transceiver 314 and the memory 316 by communication means 318 known in the art. The network node 302 may be configured for both wireless and wired communications in wireless and wired communication systems, respectively. The wireless communication capability is provided with an antenna or antenna array 320 coupled to the transceiver 314, while the wired communication capability is provided with a wired communication interface 322 coupled to the transceiver 314.

That the network node 302 is configured to perform certain actions can in this disclosure be understood to mean that the network node 302 comprises suitable means, such as e.g. the processor 312 and the transceiver 314, configured to perform said actions.

According to embodiments of the invention the network node 302 is configured to obtain a pre- PDU session establishment request 502 from a client device 100. The pre-PDU session establishment request 502 comprises a flightpath and a QoS requirement of the PDU session. The network node 302 is further configured to provide a pre-PDU session establishment response 504 to the client device 100. The pre-PDU session establishment response 504 comprises a set of routes associated with the flightpath and each route in the set of routes is associated with a supported QoS.

Fig. 4 shows a flow chart of a corresponding method 400 which may be executed in a network node 302, such as the one shown in Fig. 3. The method 400 comprises obtaining 402 a pre- PDU session establishment request 502 from a client device 100, wherein the pre-PDU session establishment request 502 comprises a flightpath and a QoS requirement of the PDU session. The method 400 further comprises providing 404 a pre-PDU session establishment response 504 to the client device 100, wherein the pre-PDU session establishment response 504 comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS.

Fig. 5 shows signalling between the client device 100 and the network node 302 according to an embodiment of the invention. The client device 100 may trigger the signalling shown in Fig. 5 prior to establishing a PDU session to acquire information about supported QoS of PDU sessions along potential routes to a destination. This information can e.g. be used by the client device 100 to plan its route to the destination. In step I in Fig. 5, the client device 100 provides the pre-PDU session establishment request 502 to the network node 302. The pre-PDU session establishment request 502 comprises the flightpath and the QoS requirement of the PDU session. The flightpath may comprise information about current and planned future location(s) of the client device 100. In embodiments, the flightpath at least comprises a starting point which is the current location and a destination point. The starting point and the destination point may e.g. be so-called waypoints defined as three-dimensional locations e.g. according to 3GPP TS 36.355. The flightpath may further comprise one or more intermediate waypoints, e.g. a p re-configured number of waypoints. In addition, time-stamps per waypoints may be comprised in the flightpath. Furthermore, the flightpath may in embodiments comprise one or more possible routes between starting point and the destination point. The QoS requirement of the PDU session may be a QoS profile of a QoS flow. In 5G, a PDU Session might have one or more QoS flows and the required QoS is associated with a QoS profile of the flow(s). Each QoS profile might be characterized by a number of QoS parameters such as 5G QoS identifier (5QI), allocation and retention priority (ARP), and other parameters depending on whether the QoS flow pertains to guaranteed bit rate (GBR) or non-GBR. In the case of GBR QoS flows, the QoS profile includes uplink (UL) and downlink (DL) guaranteed flow bit rate (GFBR) as well as UP and DL maximum flow bit rate (MFBR) and may optionally contain UL and DL maximum packet loss rate. In addition, 5QI is a scalar that is used as a reference to 5G QoS characteristics that at least consist of packet delay budget (PDB), packet error rate (PER), and default maximum data burst volume (MDBV).

The network node 302 obtains the pre-PDU session establishment request 502 from the client device 100 and thereby the flightpath and the QoS requirement of the PDU session. Based on the flightpath and the QoS requirement of the PDU session, the network node 302 determines a set of routes associated with the flightpath, as well as the supported QoS associated with each route in the set of routes. When the flightpath comprises the starting point and the destination point, the set of routes may comprise one or more potential routes identified by the network node 302 to get from the starting point to the destination point. When the flightpath comprises one or more possible routes between the starting point and the destination point, the set of routes may comprise the one or more possible routes identified by the flightpath. Each route in the set of routes is further assigned a route identifier which are unique identifiers provided in suitable format according to conventional methods. In a similar way as for the flightpath, each route may be represented with a series of waypoints defined as three- dimensional locations, optionally with time stamps per waypoint. Further details related to how the network node 302 determines the set of routes is described below with reference to Fig. 8. The network node 302 provides the determined set of routes together with its unique identifier and the supported QoS associated with each route to the client device 100 in the pre-PDU session establishment response 504. In step II in Fig. 5, the client device 100 hence obtains the pre-PDU session establishment response 504 from the network node 302. Thereby, the client device 100 obtains the set of routes associated with the flightpath, where each route in the set of routes is associated with a supported QoS and a route identifier. The client device 100 hence obtains information about achievable QoS of PDU sessions along the set of routes and may use this information to plan its route to the destination.

Fig. 6 shows signalling between the client device 100 and the network node 302 according to an embodiment of the invention. In step I in Fig. 6, the client device 100 determines to provide a PDU session establishment request 506 to the network node 302. The client device 100 may be in a RRC_CONNECTED or an RRCJNACTIVE state. Hence, the client device 100 may in step I determine that a new PDU session should be established or an existing PDU session should be resumed. However, before the client device 100 provides the PDU session establishment request 506 to the network node 302, the client device 100 provides the pre- PDU session establishment request 502 to the network node 302, as shown in step II in Fig. 6. As previously described, the pre-PDU session establishment request 502 comprises the flightpath and the QoS requirement of the PDU session.

When the network node 302 obtains the pre-PDU session establishment request 502 from a client device 100, the network node 302 determines a set of routes based on the pre-PDU session establishment request 502, in step III. Each route in the set of routes is associated with the flightpath and further associated with a supported QoS. The network node 302 may determine the set of routes based on the pre-PDU session establishment request 502 and at least one of: spatial location of network access nodes along the set of routes, residual capacities of network access nodes along the set of routes, vehicle traffic information for the set of routes, and weather information for the set of routes. Further details related to the determination of the set of routes will be described below with reference to Fig. 8.

In step IV in Fig. 6, the network node 302 provides the determined set of routes in the pre-PDU session establishment response 504 to the client device 100. The client device 100 receives the pre-PDU session establishment response 504 from the network node 302 and hence the set of routes determined by the network node 302. Each route in the set of routes is associated with a supported QoS and a route identifier.

In step V, the client device 100 selects a route among the set of routes derived from the pre- PDU session establishment response 504 from the network node 302. In embodiments, the client device 100 selects the route among the set of routes based on its associated supported QoS. The client device 100 may be configured to select the route among the set of routes which has the most suitable supported QoS. However, other selection principles may be used when selecting the route. In embodiments, the network node 302 may assign a priority to each route in the set of routes. In such embodiments, the client device 100 may select the route among the set of routes which has the highest priority. The selection of the route may further be based on additional input such as e.g. input from a user of the client device 100, i.e. a person using the client device 100. Hence, the client device 100 may in embodiments select the route among the set of routes based on the associated supported QoSs and the user input.

When the client device 100 has selected the route among the set of routes, the client device 100 provides a PDU session establishment request 506 to the network node 302, as shown in step VI in Fig. 6 as long as the required QoS support is partially or fully possible at least in one route. The PDU session establishment request 506 comprises the route identifier of the selected route. The network node 302 obtains the PDU session establishment request 506 from the client device 100, wherein the PDU session establishment request 506 comprises the route identifier of the selected route of the client device 100. Based on the PDU session establishment request 506, the network node 302 determines QoS associated with the established PDU session in step VII in Fig. 6. In other words, when the PDU session has been established between the client device 100 and the network, the network node 302 starts estimating and monitoring the QoS associated with the PDU session, which means that the network node 302 needs to know the selected route. This may include the network node 302 determining the QoS at future time instances for the PDU session.

According to embodiments of the invention the client device 100 provides the pre-PDU session establishment request 502 to the network node 302 via a network access node 304 and an access and mobility management function (AMF) 306. The network node 302 is therefore a prediction function of the network according to this embodiment. Fig. 7 illustrates such an embodiment in which the client device 100 establishes a radio resource control (RRC) connection setup or a RRC connection resume with the network access node 304 prior to providing the pre-PDU session establishment request 502 to the network node 302. Hence, in step I in Fig. 7, a RRC connection setup or a RRC connection resume is performed with the network access node 304. Whether the procedure in step I in Fig. 7 is an RRC connection setup or an RRC connection resume depends on the current state of the client device 100. The RRC connection setup or the RRC connection resume may be performed according to conventional RRC connection procedures, e.g. defined by different standards.

In step II in Fig. 7, the client device 100 provides the pre-PDU session establishment request 502 to the network node 302 via the network access node 304 and the AMF 306. As previously described the pre-PDU session establishment request 502 may comprise the flightpath and the QoS requirement of the PDU session. In embodiments, the pre-PDU session establishment request 502 may be comprised in a RRC connection setup complete 512 or a RRC connection resume complete 512’ to the network access node 304. The RRC connection setup complete 512 or the RRC connection resume complete 512’ may be transmitted by the client device 100 as part of the RRC procedure with the network access node 304 in step I. The pre-PDU session establishment request 502 may be comprised in the RRC connection setup complete 512 or the RRC connection resume complete 512’ as a non-access stratum (NAS) container, e.g. in an existing session management container. In this way, the network access node 304 can forward the pre-PDU session establishment request 502 without having to interpret the content. After conventional access stratum (AS) and NAS security handling (not shown in Fig. 7), the network access node 304 forwards the pre-PDU session establishment request 502 to the AMF 306 in a first message 522. The first message 522 may be an existing or new signalling message. The network access node 304 may e.g. include the pre-PDU session establishment request 502 in a convention initial UE message or UE context resume request in 3GPP systems which implies that the client device in such cases corresponds to a UE. The AMF 306 in turn forwards the pre-PDU session establishment request 502 to the network node 302 using a second message 532. The second message 532 may be an existing or new signalling message. Thus, the network node 302 obtains the pre-PDU session establishment request 502 from the client device 100 via the network access node 304 and the AMF 306.

In step III in Fig. 7, the network node 302 determines the set of routes based on the pre-PDU session establishment request 502. Step III may e.g. comprise the network node 302 determining the set of routes associated with the flightpath from the pre-PDU session establishment request 502, as previously described. When the network node 302 has determined the set of routes based on the pre-PDU session establishment request 502, the network node 302 provide the pre-PDU session establishment response 504 comprising the set of routes associated with the flightpath to the client device 100 along which the required QoS support that can be possible. The network node 302 provides the pre-PDU session establishment response 504 to the client device 100 via the AMF 306 and the network access node 304, as shown in step IV in Fig. 7. In a similar way as for the pre-PDU session establishment request 502, the pre-PDU session establishment response 504 may be comprised in new or existing signalling messages between the nodes. Hence, the network node 302 may e.g. include the pre-PDU session establishment response 504 in a third message 534 to the AMF 306 which in turn may include the pre-PDU session establishment response 504 in a fourth message 524 to the network access node 304. For example, if the AMF 306 received the pre-PDU session establishment request 502 in an initial UE message from the network access node 304, the AMF 306 may include the pre-PDU session establishment response 504 in a DL NAS transport message. On the other hand, if the AMF 306 received the pre-PDU session establishment request 502 in a UE context resume request from the network access node 304, the AMF 306 may include the pre-PDU session establishment response 504 in a UE context resume response. From the network access node 304 to the client device 100 the pre-PDU session establishment response 504 may be comprised in a downlink information transfer 514 from the network access node 304.

Step V and VI in Fig. 7 corresponds to step V and VI in Fig. 6. In other words, the client device 100 selects a route among the set of routes derived from the received pre-PDU session establishment response 504 and provides a PDU session establishment request 506 to the network node 302. In the embodiment shown in Fig. 7, the PDU session establishment request 506 is provided to the network node 302 via the AMF 306. Thus, the AMF 306 receives the PDU session establishment request 506 and initiates the establishment of the PDU session based on the PDU session establishment request 506. The AMF 306 further notifies the network node 302 when the PDU session has been established such that the network node 302 can start to monitor the PDU session and determine the future QoS associated with the PDU session.

Fig. 8 shows a flow chart of a method 800 according to an embodiment of the invention. The method 800 may be performed by the network node 302 to determine the set of routes based on the pre-PDU session establishment request 502 from the client device 100.

In step 802, the network node 302 collects input data such as e.g. information associated with spatial location of network access nodes, residual capacities of network access nodes, vehicle traffic information, and weather information. Step 802 is performed continuously, and the collected input data is stored such that determination of the set of routes can be based on historical data.

In step 804, the network node 302 obtains the pre-PDU session establishment request 502 from the client device 100. From the pre-PDU session establishment request 502, the network node 302 derives the flightpath and the QoS requirement of the PDU session.

Based on the information obtained in step 804, the network node 302 determines the set of routes in step 806. The network node 302 may first determine all potential routes based on the flightpath, e.g. all potential routes between the starting point and the destination point in the form of waypoints. In embodiments, this information may be provided by the client device 100 in the pre-PDU session establishment request 502 instead of being determined by the network node 302. Either way, the network node 302 determines the QoS support along all the potential routes. Firstly, the network node 302 selects one of the potential routes. As the network node 302 knows the geographical locations of each cell, the network node 302 can determine the cells that lie along the selected route. The network node 302 can thus map future positions of the client device 100 to cells along the selected route and calculate approximate time when the client device 100 will be there based on local traffic. Using this information and the input data from step 802, the network node 302 determines whether the selected route can support the QoS requirement of the PDU session requested by the client device 100. The network node 302 saves the result of the selected route along with the QoS support associated with the route. In the same way, the network node 302 then determines the QoS support for each of the potential routes and saves the result. Based on saved result for each potential route, the network node 302 determines the set of routes to indicate to the client device 100. The set of routes may comprise one or more routes which fulfils the QoS requirements of the client device 100 for the PDU session. Each route may further be assigned a priority, where the highest priority e.g. may be assigned to the route which has the highest probability to be able to support the QoS requirements of the client device 100 for the PDU session. However, in some case none of the evaluated routes may fulfil the QoS requirements of the client device 100 for the PDU session. In such cases, the network node 302 may determine to indicate one or more of the routes with the QoS support closest to the QoS requirements of the client device 100 for the PDU session.

In step 808, the network node 302 provides the set of routes determined in step 806 to the client device 100 in the pre-PDU session establishment response 504.

One way for a UE to indicate its QoS requirement in its pre-packet data unit, PDU, session establishment request (502) is to employ the same NAS information that is used as part of PDU Session Establishment Request. Another way is to use PDU Session Resources To Be Setup List IE of the HANDOVER REQUEST message as specified in specification TS 38.423 V15.2.0.

Fig. 9 shows a flow chart of a method according to an embodiment of the invention. The method in Fig. 9 may also be performed by the network node 302. In this embodiment a client device corresponds to a UE, a network node corresponds to a PF, and a network access node to a gNB. The method in Fig. 9 comprises:

• In step I, a PF collects geographical locations of each gNB within a PLMN. Given that 5G QoS is delivered by gNB cells and different gNB cells have different load conditions and capabilities, for the PF to determine future QoS the PF has to map UE instantaneous location to one or many cells. In other words, a PF has to know as to which cell will serve a UE in question at a future time instance for it to determine future QoS.

• Given that QoS provisioning of a cell depends on instantaneous load, residual capacity and capabilities of the cell, a PF has to collect this information in step II. • Given that QoS experienced by a UE depends on local weather and how soon it reaches a given cell that in turn depends on road physical traffic, the PF will collect local weather and road physical traffic condition per cell in step III.

• At decision point IV, the PF checks whether it has received a pre-packet data unit, PDU, session establishment request from a UE. Such a request consists of a flightpath and a QoS requirement of the PDU session. Flight path minimally indicates a starting position and a destination position.

• If the PF has received, a pre-PDU session establishment request, the PF will determine at step V the total number of physical routes that are possible between a given starting position of a UE and its destination and start considering the first route k. The total number of possible routes is considered to be t where k<=t. If, on the other hand, no such a request is received, the PF will continuously carry out steps II and III.

• At decision point VI, the PF checks whether k<=t.

• If the check at the decision point VI yields a positive result (i.e. Yes in step VI), at step VII, the PF will consider the first physical route k= 1.

• For the first physical route k= 1, in step VIII, the PF will determine identities of cells that make up a physical route k= 1. Suppose the total number of cells that cover the physical route k= 1 is c, the PF will check whether each cell n that belong to c (as checked in step IX) can meet the QoS requirement in steps XI and XII. If it is determined that cell n can meet PDU Session QoS requirements, the measure of its support is stored and steps XI and XII will be repeated for other cells that make up the considered physical route k. On the other hand, in step XII if it is determined that a cell n cannot fulfill the QoS requirements, the PF will move to decision point VI after next route chosen in step X for similar analysis.

• At the decision point VI if it is decided that all possible route has been considered (i.e.

No in step VI), the PF will prioritize routes in terms of QoS Support capability and notify a UE in step XIV.

The client device 100 herein, may be denoted as a user device, a User Equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and/or a mobile terminal, is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in this context may be, for example, portable, pocket-storable, hand-held, computer- comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server. The UE can be a Station (STA), which is any device that contains an IEEE 802.1 1 -conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The UE may also be configured for communication in 3GPP related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth generation wireless technologies, such as New Radio.

The network node 302 herein may be termed the prediction function network node that is configured to perform a prediction function concerning a change in QoS associated with a PDU Session of the client device 100. The network node 302 can be configured to collect capabilities of cells located along the client device 100 trajectory/ flight path, especially in terms of Slice Support the client device 100 is currently using/ allocated, Radio Access Technology (RAT) type, frequency of operations (as some slices will be on certain frequency ranges), Carrier Aggregation (CA), Dual Connectivity (DC) and Coordinated Multipoint (COMP) Support, etc.

The network access node 304 herein may also be denoted as a radio network access node, an access network access node, an access point, or a base station, e.g. a Radio Base Station (RBS), which in some networks may be referred to as transmitter,“gNB”,“gNodeB”,“eNB”, “eNodeB”,“NodeB” or“B node”, depending on the technology and terminology used. The radio network access nodes may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. The radio network access node can be a Station (STA), which is any device that contains an IEEE 802.1 1 -conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The radio network access node may also be a base station corresponding to the fifth generation (5G) wireless systems.

The AMF 306 herein may support the following functionality which may be supported in a single instance of an AMF: Termination of RAN CP interface (N2); Termination of NAS (N1 ), NAS; ciphering and integrity protection; Registration management; Connection management; Reachability management; Mobility Management; Lawful intercept (for AMF events and interface to LI System); Provide transport for SM messages between UE and SMF; Transparent proxy for routing SM messages; Access Authentication; Access Authorization; Provide transport for SMS messages between UE and SMSF; Security Anchor Functionality (SEAF) as specified in specification TS 33.501 ; Location Services management for regulatory services; Provide transport for Location Services messages between UE and LMF as well as between RAN and LMF; EPS Bearer ID allocation for interworking with EPS; UE mobility event notification. Further details on AMF can e.g. be found in specification TS 23.501 V15.3.0. Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive.

Moreover, it is realized by the skilled person that embodiments of the client device 100 and the network node 302 comprises the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the solution. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.

Especially, the processor(s) of the client device 100 and the network node 302 may comprise, e.g., one or more instances of a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The expression“processor” may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

1. A client device (100) for a wireless communication system (500), the client device (100) being configured to

provide a pre-packet data unit, PDU, session establishment request (502) to a network node (302), wherein the pre-PDU session establishment request (502) comprises a flightpath and a quality-of-service, QoS, requirement of the PDU session;

obtain a pre-PDU session establishment response (504) from the network node (302), wherein the pre-PDU session establishment response (504) comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS and a route identifier.

2. The client device (100) according to claim 1 , configured to

select a route among the set of routes based on its associated supported QoS;

provide a PDU session establishment request (506) to the network node (302), wherein the PDU session establishment request (506) comprises the route identifier of the selected route.

3. The client device (100) according to claim 2, configured to

select the route among the set of routes based on the associated supported QoSs and input.

4. The client device (100) according any of the preceding claims, wherein the pre-PDU session establishment request (502) is comprised in a radio resource control, RRC, connection setup complete (512) or a RRC connection resume complete to a network access node (304).

5. The client device (100) according to claim 4, configured to

establish an RRC connection setup or an RRC connection resume with the network access node (304) prior to providing the pre-PDU session establishment request (502) to the network node (302).

6. The client device (100) according to any of the precoding claims, wherein the pre-PDU session establishment response (504) is comprised in a downlink information transfer (514) from the network access node (304).

7. The client device (100) according to any of the preceding claims, wherein the flightpath comprises a starting point and a destination point.

8. A network node (302) for a wireless communication system (500), the network node (302) being configured to

obtain a pre-PDU session establishment request (502) from a client device (100), wherein the pre-PDU session establishment request (502) comprises a flightpath and a QoS requirement of the PDU session;

provide a pre-PDU session establishment response (504) to the client device (100), wherein the pre-PDU session establishment response (504) comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS.

9. The network node (302) according to claim 8, configured to

determine the set of routes based on the pre-PDU session establishment request (502) and at least one of: spatial location of network access nodes along the set of routes, residual capacities of network access nodes along the set of routes, vehicle traffic information for the set of routes, and weather information for the set of routes.

10. The network node (302) according to claim 8 or 9, wherein obtain the pre-PDU session establishment request (502) comprises

obtain the pre-PDU session establishment request (502) from the client device (100) via a network access node (304) and an AMF (306).

1 1. The network node (302) according to any of claims 8 to 10, wherein provide the pre-PDU session establishment response (504) comprises

provide the pre-PDU session establishment response (504) to the client device (100) via an AMF (306) and a network access node (304).

12. The network node (302) according to any of claims 8 to 1 1 , configured to

obtain a PDU session establishment request (506) from the client device (100), wherein the PDU session establishment request (506) comprises a route identifier of a selected route of the client device (100);

determine QoS associated with the established PDU session based on the PDU session establishment request (506).

13. A method (200) for a client device (100), the method (200) comprising providing (202) a pre-packet data unit, PDU, session establishment request (502) to a network node (302), wherein the pre-PDU session establishment request (502) comprises a flightpath and a quality-of-service, QoS, requirement of the PDU session;

obtaining (204) a pre-PDU session establishment response (504) from the network node

(302), wherein the pre-PDU session establishment response (504) comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS and a route identifier. 14. A method (400) for a network node (302), the method (400) comprising

obtaining (402) a pre-PDU session establishment request (502) from a client device (100), wherein the pre-PDU session establishment request (502) comprises a flightpath and a QoS requirement of the PDU session;

providing (404) a pre-PDU session establishment response (504) to the client device (100), wherein the pre-PDU session establishment response (504) comprises a set of routes associated with the flightpath, and wherein each route in the set of routes is associated with a supported QoS.

15. A computer program with a program code for performing a method according to claim 13 or 14 when the computer program runs on a computer.