EP4136811A1

EP4136811A1 - Wireless communication system

Info

Publication number: EP4136811A1
Application number: EP20720391.0A
Authority: EP
Inventors: Borislava GAJIC; Christian MANNWEILER; Peter Rost; Rakash SIVASIVA GANESAN
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2020-04-15
Filing date: 2020-04-15
Publication date: 2023-02-22
Also published as: WO2021209122A1

Abstract

There is provided an apparatus comprising means for, in response to receiving, at the apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream, and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

Description

Title

WIRELESS COMMUNICATION SYSTEM

Field

The present application relates to a method, apparatus, and computer program for a wireless communication system.

Background

A communication system be a facility that enables communication sessions between two or more entities such as user terminals, base stations/access points and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided, for example, by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

Summary

According to an aspect, there is provided an apparatus comprises means for: in response to receiving, at the apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

The means may be further configured to perform: receiving, at the apparatus, the time period that network resources should be reserved for the data stream.

The means may be further configured to perform: determining, at the apparatus, the time period that network resources should be reserved for the data stream.

The message may comprise a multiple stream registration protocol message.

The means for determining may be for determining the time period based on the received information about the message. The means for determining may be for determining the time period based on user equipment subscription data available to the apparatus and stored at a unified data management entity.

The means for determining may be for determining the time period based on at least one operator policy available to the apparatus stored at the policy charging function.

The means for determining may be for determining the time period based on information about a resource availability of a network.

The means for determining may be for determining the time period based on a value of one or more other time periods for other data streams that are active in a network.

The means may be further configured to perform: before the time period has expired, receiving a success message indicating that data from the data stream is required by a receiving entity; and in response to the reception of the success message, discarding the time period and maintaining the protocol data unit session.

The means may be further configured to perform: processing the success message to determine if the success message is linked to the first message by matching an identification of the message to an identification of the success message.

The means may be further configured to perform: determining at least one update for the message based on the received information so that quality of service characteristics for the data stream are met; and providing the determined at least one update to an application function, to allow the application function to perform a protocol data unit session modification.

The means may be further configured to perform: storing a binding between the modified protocol data unit session, quality of service characteristics of the data stream, and the time period for reserving the network resources for the data stream.

The means for releasing the network resources may be for releasing the resources by re-modifying the protocol data unit session based on the binding between the modified protocol data unit session, the quality of service of the data stream, and the time period for reserving the network resources for the data stream.

The apparatus may be a session management function.

The apparatus may be comprised within a fifth-generation, 5G, bridge for a time-sensitive network. The means may comprise at least one processor, and at least one memory including computer program code.

According to an aspect, there is provided a method, comprising: in response to receiving, at an apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

The method may comprise receiving, at the apparatus, the time period that network resources should be reserved for the data stream.

The method may comprise determining, at the apparatus, the time period that network resources should be reserved for the data stream.

The message may comprise a multiple stream registration protocol message.

The determining may comprise determining the time period based on the received information about the message.

The determining may comprise determining the time period based on user equipment subscription data available to the apparatus and stored at a unified data management entity.

The determining may comprise determining the time period based on at least one operator policy available to the apparatus stored at the policy charging function.

The determining may comprise determining the time period based on information about a resource availability of a network.

The determining may comprise determining the time period based on a value of one or more other time periods for other data streams that are active in a network.

The method may comprise before the time period has expired, receiving a success message indicating that data from the data stream is required by a receiving entity; and in response to the reception of the success message, discarding the time period and maintaining the protocol data unit session.

The method may comprise processing the success message to determine if the success message is linked to the first message by matching an identification of the message to an identification of the success message.

The method may comprise determining at least one update for the message based on the received information so that quality of service characteristics for the data stream are met; and providing the determined at least one update to an application function, to allow the application function to perform a protocol data unit session modification.

The method may comprise storing a binding between the modified protocol data unit session, quality of service characteristics of the data stream, and the time period for reserving the network resources for the data stream.

The releasing of the network resources may comprise releasing the resources by re-modifying the protocol data unit session based on the binding between the modified protocol data unit session, the quality of service of the data stream, and the time period for reserving the network resources for the data stream. The method may be performed by a session management function.

According to another aspect, there is provided an apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: in response to receiving, at the apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: receiving, at the apparatus, the time period that network resources should be reserved for the data stream.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining, at the apparatus, the time period that network resources should be reserved for the data stream.

The message may comprise a multiple stream registration protocol message.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining the time period based on the received information about the message.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining the time period based on user equipment subscription data available to the apparatus and stored at a unified data management entity. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining the time period based on at least one operator policy available to the apparatus stored at the policy charging function. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining the time period based on information about a resource availability of a network.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining the time period based on a value of one or more other time periods for other data streams that are active in a network.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: before the time period has expired, receiving a success message indicating that data from the data stream is required by a receiving entity; and in response to the reception of the success message, discarding the time period and maintaining the protocol data unit session.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: processing the success message to determine if the success message is linked to the first message by matching an identification of the message to an identification of the success message.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining at least one update for the message based on the received information so that quality of service characteristics for the data stream are met; and providing the determined at least one update to an application function, to allow the application function to perform a protocol data unit session modification. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: storing a binding between the modified protocol data unit session, quality of service characteristics of the data stream, and the time period for reserving the network resources for the data stream. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: releasing the resources by re-modifying the protocol data unit session based on the binding between the modified protocol data unit session, the quality of service of the data stream, and the time period for reserving the network resources for the data stream.

The apparatus may comprise a session management function.

According to an aspect, there is provided a computer program comprising computer executable instructions which when run on one or more processors perform: in response to receiving, at an apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

A computer product stored on a medium may cause an apparatus to perform the methods as described herein.

An electronic device may comprise apparatus as described herein.

In the above, various aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described above.

Various other aspects and further embodiments are also described in the following detailed description and in the attached claims.

According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

List of abbreviations:

AF: Application Function

AUSF: Authentication Server Function

AMF: Access Management Function

BS: Base Station

DN: Data Network DS-TT: Device-side TSN Translator

DU: Distributed Unit eNB: eNodeB gNB: gNodeB MoT: Industrial Internet of Things LTE: Long Term Evolution LRP: Link-local Registration Protocol NEF: Network Exposure Function NF: Network Function NR: New Radio NRF: Network Repository Function NW-TT: Network-side TSN Translator MMRP: Multiple MAC Registration Protocol MS: Mobile Station MSRP: Multiple Stream Registration Protocol MVRP: Multiple VLAN Registration Protocol PLMN: Public Land Mobile Network QoS: Quality of Service RAN: Radio Access Network SRP: Stream Reservation Protocol RF: Radio Frequency TSN: Time-Sensitive Network UE: User Equipment 3GPP: 3^rd Generation Partnership Project 5G: 5^th Generation

5GC: 5G Core network 5G-AN: 5G Radio Access Network 5GS: 5G System Description of Figures

Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 shows a schematic representation of a 5G system;

Figure 2 shows a schematic representation of a control apparatus; Figure 3 shows a schematic representation of a terminal;

Figure 4 shows a schematic representation of communications between a network function and service communication proxies;

Figure 5 shows an example signalling diagram between a network client, network proxy and network server;

Figure 6 shows an example method flow diagram performed by a network entity; and

Figure 7 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the method of Figure 6.

Detailed description

Before explaining in detail some examples of the present disclosure, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 3 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in Figure 1, mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices 102 are provided wireless access via at least one base station (not shown) or similar wireless transmitting and/or receiving node or point. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices. The communication device may access a carrier provided by a station or access point, and transmit and/or receive communications on the carrier.

In the following certain examples are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the examples of disclose, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to Figures 1 , 2 and 3 to assist in understanding the technology underlying the described examples. Figure 1 shows a schematic representation of a 5G system (5GS) 100. The 5GS may comprises a terminal 102, a 5G access network (5G-AN) 106, a 5G core network (5GC) 104, one or more network functions (NF), one or more application function (AF) 108 and one or more data networks (DN) 110. The 5G-AN 106 may comprise one or more gNodeB (gNB) distributed unit functions connected to one or more gNodeB (gNB) centralized unit functions.

The 5GC 104 may comprise an access management function (AMF) 112, a session management function (SMF) 114, an authentication server function (AUSF) 116, a user data management (UDM) 118, a user plane function (UPF) 120, a network exposure function (NEF) 122 and/or other NFs. Some of the examples as shown below may be applicable to 3GPP 5G standards. Flowever, some examples may also be applicable to 4G, 3G and other 3GPP standards.

In a communication system, such as that shown in Figure 1, mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices are provided with wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. The terminal is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices. The communication device may access a carrier provided by a station or access point, and transmit and/or receive communications on the carrier.

Figure 2 illustrates an example of a control apparatus 200 for controlling a function of the 5G-AN or the 5GC as illustrated on Figure 1. The control apparatus may comprise at least one random access memory (RAM) 211a, at least on read only memory (ROM) 211b, at least one processor 212, 213 and an input/output interface 214. The at least one processor 212, 213 may be coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects. The software code 215 may be stored in the ROM 211 b. The control apparatus 200 may be interconnected with another control apparatus 200 controlling another function of the 5G-AN or the 5GC. In some examples, each function of the 5G-AN or the 5GC comprises a control apparatus 200. In alternative examples, two or more functions of the 5G-AN or the 5GC may share a control apparatus. Figure 3 illustrates an example of a terminal 300, such as the terminal illustrated on Figure 1. The terminal 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device or any combinations of these or the like. The terminal 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.

The terminal 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 3 transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

The terminal 300 may be provided with at least one processor 301 , at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302a and the ROM 211 b. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302b.

The processor, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304. The device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device. Some examples may be related to a scenario in a tactile industrial network, also known as Industrial loT (Eliot) or Industry 4.0 networks. Here, 3GPP technologies are applied in addition to wired time-sensitive networking (TSN) in industrial environments. One of the objectives of time-sensitive networking (TSN) is to provide guaranteed data delivery within a specified time window. This may provide flexibility (in terms of mobility) and scalability (in terms of number of sensors or actuators). 3GPP has finalized the Study on 5GS Enhanced support of Vertical and LAN Services (SA2 TR 23.734) which selects the option for integration of 3GPP and TSN called bridge model (black box) as a baseline for 3GPP normative work. The 3GPP has worked on Release 16 regarding the 5GS support of TSN, where a fully centralized configuration model and scheduled traffic (time-aware scheduling) of TSN has been considered. The 5GS support for this model has been described in 3GPP TS 23.501.

For the fully distributed configuration model, the SRP (Stream Reservation Protocol) is utilized. IEEE has specified Stream Reservation Protocol (SRP) (IEEE Std 802.1Q-2018: Clause 35) and Multiple Stream Registration Protocol (MSRP) (IEEE

Std 802.1Q-2018: Clause 35.1). SRP utilizes three signalling protocols, MMRP (Multiple MAC Registration Protocol), MVRP (Multiple VLAN Registration Protocol) and MSRP (Multiple Stream Registration Protocol), to establish stream reservations across a bridged network. Whereas MMRP and MVRP are mainly used to control the propagation of end station declarations, MSRP is a signalling protocol that enables the reservation of network resources that will guarantee the transmission and reception of data streams across a network with the requested QoS.

Currently, IEEE specifies two amendments to the IEEE 802.1Q standard. These include IEEE 802.1CS (Link-Local Reservation Protocol) and IEEE 802.1Qdd (Resource Reservation Protocol). The link-local registration protocol may replace the Multiple Registration Protocol (MRP) and allow for the exchange of larger databases. MSRP is an application running over MRP. For industrial networks utilizing the fully distributed model, MRP may be replaced by the Resource Reservation Protocol as specified in IEEE 802.1Qdd, which is an application running over LRP. However, the Resource Reservation Protocol (RRP) may extend the MSRP. The methods and apparatus as described below may be equally applicable to RRP. The methods and apparatus as described below may be equally applicable to LRP. A TSN stream is a data flow between an end station, called a ‘Talker’, to another end station called a ‘Listener’. TSN bridges may be configured by a Central Network Controller (CNC) to provide connectivity for the TSN stream in the network.

For the fully distributed configuration model, SRP is utilized. As MMRP and MVRP are either optionally used, or can be circumvented by using the network management tool and pre-configuration of network entities, MSRP represents the fundamental part of SRP and realisation of the fully distributed model. Some of the following examples will be related to MSRP. Using MSRP, a stream source end station (i.e. Talker) indicates stream requirements before transmitting the actual stream data. Such requirements may be indicated to the network using “Talker Advertise” declarations which may also include the worst-case latency indicator. The “Talker Advertise” declaration may be propagated by bridges on the path towards potential ‘Listeners’ as long as the stream requirements can be met by individual bridges. During the propagation of a “Talker Advertise” declaration, the accumulated latency is updated at each hop/bridge. ‘Listeners’ may therefore have the information about the worst-case latency. The ‘Listener’ can use this information to decide if the latency is too large for acceptable reception of the stream.

The accumulated latency may grow by a bridge-specific value. The bridge specific value could be, for example, “portTcMaxLatency” in IEEE 802.1 Q. The “ portTcMaxLatency” value represents the worst-case latency that the bridge could add to the total packet latency. “portTcMaxLatency” in IEEE 802.1Q is used as an example only, other suitable parameters in suitable standards may be utilised. The “portTcMaxLatency” per hop is equal to the sum of the following: a) (Equal or higher priority traffic) The time required to empty the queue in which frames of that priority are placed, if that queue and all higher priority queues are full. b) (Lower priority traffic) The time required to transfer one lower priority frame of maximum size that could have just started transmitting as the current priority frame was queued up. c) (Internal processing) The worst-case time required by the Bridge to transfer a received frame from the input port to the output queue. d) (Wire propagation time) The time required for the first bit of the frame to propagate from the output port to the receiving device. e) (Media access delay) The time required to wait for the media to become available for transmission.

‘Listeners’ receiving “Talker Advertise” declarations and willing to receive the stream data will send back a “Listener Ready” declaration to the ‘Talker’. During the propagation of the “Listener Ready” declarations the bridge/bridges reserves the resources to deliver the stream data. When the ‘Talker’ receives a “Listener Ready” declaration, the ‘Talker’ starts transmitting the stream.

The IEEE802.1 Qcc standard defines additional attributes in MSRP messages which provide an optional mechanism to Talkers’ and ‘Listeners’ to define their requirements towards the network. For example, the mechanism may define a “UserToNetworkRequirements” attribute. The “UserToNetworkRequirements” attribute can be used to express the requirements on a maximum latency that the ‘Talker’ and/or ‘Listener’ requires for a particular stream. The bridges can compare the maximum latency requirements with an “AccumulatedLatency” attribute included in the declaration message. In the case that “AccumulatedLatency” exceeds a maximum latency of the ‘Talker’, the bridge may change the “Talker Advertise” to a “Talker Failed” declaration. The “Talker Failed” declaration may include a failure code 21 indicating that the maximum latency has been exceeded.

Some of the following examples address the problem of resource reservation within 5GS. According to the MSRP procedures, a prerequisite for network resource reservation is the exchange of ‘Talker’ and ‘Listener’ messages on readiness to send and to receive the stream with specific QoS requirements. This means that the 5GS bridge, as any other bridge on the path between ‘Talker’ and ‘Listener’, may first forward the ‘Talker’ messages towards potential ‘Listeners’, updating the content of such messages with an indication of bridge capabilities and available resources. As a next step, after the corresponding ‘Listener’ messages are received, the bridge can reserve the resources previously indicated as available. This may be done during the updating and forwarding of the “Talker Advertise” declaration. In fixed networks, the resource availability at a bridge may be relatively stable over time and may change due to the setup of new streams. In a 5GS bridge, the resource availability may be more volatile due to the nature of the wireless medium. There may be less guarantees that the amount of resources indicated during the forwarding of a ‘Talker’ message will actually be available once the corresponding ‘Listener’ message is received. There may be a trade-off between guaranteeing the availability of resources for a TSN stream, and avoiding resources being reserved for TSN streams which are not being utilised. Resources may not be utilised because ‘Listeners’ do not subscribe to a TSN stream. Therefore, there is a need to guarantee the availability of bridge resources ahead of the time that those resources will be required. However, a-priori resource reservation may be suboptimal. An example of a-priori resource reservation being reserving right after the initial “Talker Advertise” is received, without knowing if such resources will actually be required. Without verifying if such resources are required, which should lead to those unneeded resources being released, such approach may lead quickly to a resource shortage.

Some of the following examples will aim to address some of the problems identified above. In the following examples, when referring to resource reservation in the context of the 5GS bridge, the following can be assumed: - The setting up of uplink configured grants in order to minimize latency. This may be based on derived time-sensitive communications assistance information (TSCAI);

The setting up of downlink semi-persistent scheduling;

Deciding on admission of additional streams under given resource constraints. Admission control can be used because once a TSN stream is admitted, the guaranteed performance is to be provided. It is therefore useful to know which devices desire specific TSN streams or provide TSN data.

IEEE TSN is standardised as the mechanism for communication within industrial networks. In TSN, a set of IEEE 802.1 protocols including IEEE 802. IAS- Rev, 802.1CB, 802.1Qcc, 802.1Qch, 802.1Qci, 802.1Qcj, 802.1 CM, 802.1Qcp, 802.1 Qcr, 802.1AB are applied to achieve deterministic data transmission with guaranteed low latency with time-aware devices. In parallel to TSN standardization, 3GPP has defined 5GS support of TSN considering the fully centralized TSN configuration model in Release 16, of. TS 23.501. Release 16 introduces the so-called ‘translator functions’ including a device side TSN translator (DS-TT) and a network side TSN translator (NW-TT), which perform protocol translation and adaptation.

Figure 4 schematically shows an example system architecture with 5GS appearing as a TSN bridge. The logical TSN bridge 401 includes the network functions of the 5G system. The 5G system within the logical TSN bridge 401 includes the network functions as described in Figure 1 including a RAN 413, AMF 415, UDM 417, NEF 419, SMF 421 , PCF 423, TSN AF 425 and UPF 427. There is provided a TSN system 403 which is connected to the logical TSN bridge 401 via a DS-TT 405. The DS-TT 405 is connected to a user equipment (UE) 407. The DS-TT 405 and UE 407 make up the device side of the bridge 409. There is also provided a NW-TT 411 within the UPF 427 of the 5GS.

Some examples propose an efficient procedure for resource reservation in a 5GS bridge for TSN fully distributed configuration model. The approach of some examples enables guaranteed resource availability for TSN streams once such resources are required. This may be after a “Listener Ready” MSRP message is received at the 5GS bridge. The approach of some examples also avoids long-lasting resource reservation for streams that are not required. For example, if after the “Talker Advertise” message, there was no corresponding “Listener Ready” message received at 5GS bridge the reserved resources can be freed.

Some examples allow for: a) Resource reservation within a 5GS Bridge such that resource availability guarantees can be achieved for advertised but not confirmed streams (i.e. advertised by a “Talker Advertise” message reception, but not yet confirmed by reception of a corresponding “Listener Ready” message) b) The release of reserved 5GS resources for streams that eventually are not confirmed (i.e. a “Listener Ready” message has not been received by the 5GS Bridge within a specified time)

In some examples, a so-called MSRP_reservation_timeout parameter is introduced into the stream which indicates a time for which the resources need to be reserved for after the reception of a “Talker Advertise” declaration for a given stream. The given stream may be identified with a specific “stream ID”. Such reservation of 5GS resources may impose restricted admission of newly coming UEs/end stations and their requested streams. After the MSRP_reservation_timeout has expired and a corresponding “Listener Ready” message has not been received, the reserved 5GS resources can be released such that they can be reserved for other UEs/end stations and their streams. This will be described in more detail below.

There are different types of Talker and Listener messages that can be transmitted as part of MSRP procedures: • “Talker Advertise” which is an advertisement for a stream that has not encountered any constraints along the network path.

• “Talker Failed” which is an advertisement of the stream that is not available to the listener due to constraints along the path.

• “Listener Ready” which indicates sufficient bandwidth and resources along the network path, and to one or more Listeners requesting the stream.

• “Listener Ready Failed” which indicates that at least one of the requesting listeners has sufficient bandwidth, but others may not have it. In an example an “earlier” bridge on the path may receive both ‘Listener Ready’ and ‘Listener Failed’ messages for the same stream (from different Listeners) which can merge to ‘Listener ready failed’ message.

• “Listener Asking Failed” indicates that none of the listeners are able to receive the stream due to, for example, bandwidth or resource allocation problems.

In some examples using MSRP, the actual stream transmission may happen after the Talker Advertise and according Listener Ready (or Listener Ready Failed) message are received at the bridge, and that resource reservation is followed by Listener Ready reception.

Some examples are related to a situation wherein a “Talker Advertise” is received at the 5GS Bridge, but the according “Listener Ready” message has not yet been received. This is the case for 5GS resource reservation in which 5GS QoS capabilities and resources can be declared and are assumed to be available once the “Listener Ready” is received. For example, the amount of latency to be added by 5GS can be declared.

The “Talker Advertise” message may be received at the UE side of the 5GS bridge, i.e. by the DS-TT. In other examples, the “Talker Advertise” message may be received at the network side of the 5GS bridge, i.e. by the UPF/NW-TT. From a 5GS signalling point of view there is no major difference between these two cases. The following example explained alongside Figures 5a and 5b will provide details on the scenario whereby the “Talker Advertise” is received at the UE/DS-TT side of the 5GS bridge. The procedures for the 5GS to handle the received message and to utilize the newly introduced parameter MSRP_reservation_timeout are described below.

Figures 5a and 5b show an example signalling diagram between functions of a 5GS when the 5GS is acting as a TSN bridge. At S501, the TSN device sends an MSRP message to the UE-side DS-TT. In this example of Figures 5a and 5b, the MSRP message is shown as a “Talker Advertise” message. In other examples, the MSRP message may be another suitable type of message. The TSN device may be, for example, a Talker end station. At S502, the UE/DS-TT forwards the received Talker Advertise message to a

UPF/NW-TT using an already established (default) PDU session for transmission of MSRP messages. The UE/DS-TT may utilise user plane forwarding.

At S503, the UPF/NW-TT performs the MSRP message processing. The processing may include A) identifying the message type (Talker Advertise in this case). The processing may also include B) extracting the 5GS relevant information from the MSRP message. The information may include at least one of, for example, UserToNetworkRequirements.MaxLatency, AccumulatedLatency, Data Frame Priority, Rank, MaxFrameSize, Stream ID.

At S504, the UPF/NW-TT signals the extracted information to an SMF. The SMF is able to forward this extracted information to a PCF and a TSN AF in some examples. In another example, the NW-TT derives the information relevant for updating the MSRP message, and signals only this information towards the SMF for acknowledgement and further control plane network functions. The relevant information may comprise, for example, an AccumulatedLatency field. At S505a, the SMF performs some processing for the stream. The SMF derives a MSRP_reservation_timeout value for the stream as advertised in Talker Advertise message. As an example, the derivation may be based on one or more of the following not exhaustive list of inputs (including the corresponding signalling between entities): i. The information about the stream received from the UPF and extracted from the Talker Advertise. This may include for example the stream’s importance such as a priority or a rank. ii. UE subscription data at a UDM. For example, if the UE/end device should receive a service with a requested stream quality of service (QoS). iii. Operator policies at the PCF. For example, to what extent the 5GS resources can be reserved or utilized for specific service types/QoS requirements. iv. Resource availability at the 5GS. For example, the number of UEs/end devices/streams with particular stream requirements for which the resource reservation has been already done at 5GS. v. The current value or values of MSRP_reservation_timeout for streams for which the resource reservation has already been done and still is active in the 5GS.

At S505b, the SMF can derive the information on how the Talker Advertise shall be modified. This may be based on the extracted MSRP information received from the UPF in S504, UE subscription data at the UDM, and operator policies at PCF. The Talker Advertise may be modified using an updated value of the AccumulatedLatency field. The AccumulatedLatency field may have been increased based on the bridge’s latency. The SMF derives QoS characteristics of the PDU session/QoS flow that can fulfil the QoS requirements as reported in the updated MSRP message.

At S506, the SMF signals MSRP updates to the UPF/NW-TT. In another example, the SMF acknowledges the proposal from the NW-TT rather than signalling MSRP updates.

At S507, the UPF/NW-TT forwards the updated MSRP Talker Advertise message to a TSN device in a data network (DN).

At S508, the SMF signals the information from S505b to a TSN application function (AF). The SMF may signal the information via the PCF.

At S509, the TSN AF performs a network triggered PDU session modification. This modification may use the information received by the TSN AF in S508. The flow diagram of Figure 5a continues in Figure 5b.

At S510, the SMF stores the binding between the PDU session, the QoS flow corresponding to the TSN stream, and its MSRP_reservation_timeout value. The SMF may also store how the QoS flow configuration needs to be changed if a timeout occurs. The SMF may also store a TSCAI of the TSN stream. At S511 , upon the modification of the PDU session, the SMF starts decreasing the MSRP_reservation_timeout. The MSRP_reservation_timeout may decrease until the MSRP_reservation_timeout is expired. In other examples, the MSRP_reservation_timeout may decrease until the utilisation of the established/modified PDU session is confirmed. It may be known that the utilisation of the established/modified PDU session is confirmed by receiving a corresponding Listener Ready message.

In a first scenario, as shown at S512, the 5GS bridge receives a ‘Listener Asking Failed’ or experiences a MSRP_reservation_timeout expiry.This is shown in S512a to S512c as described below. At S12a, the TSN device at the NW-TT side sends a MSRP message to the UPF. The MSRP message may be a failure message. For example, the failure message may be a ‘Listener Asking Failed’ message.

At S512b, the UPF forwards the ‘Listener Asking Failed’ message to the SMF. The ‘Listener Asking Failed’ message may be received at the SMF before the MSRP_reservation_timeout timer has expired. If there has been no ‘Listener Asking Failed’ message received then the MSRP_reservation_timeout timer may have expired.

At S512c, the SMF modifies the PDU session. The SMF may modify the PDU session to its previous state. This modification may be in response to the SMF receiving the ‘Listener Asking Failed’ message. This modification may be in response to the MSRP_reservation_timeout expiring.

Therefore, in the first scenario, if no ‘Listener Ready’ message has been received by the time the MSRP_reservation_timeout has expired, the SMF initiates the PDU session re-modification to release the resources guaranteed (based on the information from S510). The SMF can also initiate the PDU session re-modification to release the resources if a ‘Listener Asking Failed’ has meanwhile been received.

In a second scenario, as shown in S513, the 5GS receives a ‘Listener Ready’ message before the MSRP_reservation_timeout expires. This is shown in S513a to S513c as described below.

At S513a, the TSN device at the NW-TT side sends a MSRP ‘Listener Ready’ message to the UPF. This message may be sent before the MSRP_reservation_timeout exp i res .

At S513b, the UPF forwards the ‘Listener Ready’ message to the SMF. At S513c, the SMF matches the streamID of the ‘Listener Ready’ message and

Talker Advertise’ message. The SMF may discard the MSRP_reservation_timeout for the given streamID. The SMF does not need to apply another PDU session modification. The SMF can therefore maintain the current PDU Session configuration.

Therefore, in the second scenario, if a corresponding ‘Listener Ready’ is received before the MSRP_reservation_timeout expires, then the

MSRP_reservation_timeout is discarded and the PDU session configuration is maintained. In other examples, a ‘Listener Ready Failed’ message may be received instead of the ‘Listener Ready’ message. The ‘Listener Ready’ message may be first processed. The processing may be done in order to match a streamID in the ‘Listener Ready’ message with a streamID of the previously received Talker Advertise’ message. The processing may be done by the UPF/NW-TT if the message is received from the network side of the bridge. Alternatively, the processing may be done by the UE/DS-TT if received from the UE side of the bridge. The state of the PDU session may be held at the SMF. This allows processing to be done at the SMF instead as well. The UPF/NW-TT or the UE/DS-TT can forward the ‘Listener Ready’ message to SMF for processing. Alternatively, if the UPF performs the processing then the outcome of the processing may be signalled to the SMF. Figure 5b illustrates the case where the ‘Listener Ready’ is received by the UPF/NW-TT and forwarded to the SMF for processing.

In the example of Figures 5a and 5b the SMF determines the MSRP_reservation_ti meout value. However, in other examples, the PCF may determine the MSRP_reservation_ti meout value and provide the value to the SMF. The SMF can then use the MSRP_reservation_ti meout value. The SMF may then update or maintin the PDU session in the same manner as described above.

In some other examples, there may be some changes in the signalling between functions as described alongside Figures 5a and 5b.

In some examples, the AF may perform the derivation of the MSRP_reservation_ti meout value based on the information received from control network functions. These control network functions may include, for example, the SMF and the PCF. In some examples, the AF may further monitor the

MSRP_reservation_ti meout value and trigger the SMF to re-modify the PDU session once this value has expired. The AF may trigger the SMF via the PCF.

In some examples, the SMF may derive the M SRP_reservation_ti meout value but then signal it to the AF. The AF may further monitor the

In some examples, the SMF may derive the M SRP_reservation_ti meout value but then signal it to UE/DS-TT. The UE/DS-TT may further monitor the MSRP_reservation_ti meout value and trigger PDU session modification once this value has expired.

In some examples, if the ‘Listener Ready’ is received from the UE/DS-TT side, the UE/DS-TT may perform further actions beyond matching the streamID of Talker Advertise’ and ‘Listener Ready’. For example, this may be the case when both MSRP messages, Talker Advertise’ and ‘Listener Ready’, are received by the respective UE/DS-TT. This may occur in a case of UE-to-UE communications. In order to establish such connectivity between two or more UEs, at least two PDU sessions may be used. In this scenario, at least two different MSRP_reservation_timeout parameters may be created and monitored. An advertisement received from a Talker at, for example, a first UE, may be forwarded to one or more other UEs that connect to Listeners. Hence, one MSRP_reservation_timeout timer associated to the first UE session (“uplink session”) and one MSRP_reservation_timeout timer for each of the “dowlink sessions” may be created. The MSRP_reservation_timeout value for the uplink session shall be the maximum of the MSRP_reservation_timeout values of the downlink sessions.

Therefore, as shown from the examples above, some of the negative effects of MSRP procedures on 5GS resources are avoided. For example, on one side, there is no risk that required resources are unavailable once the corresponding “Listener Ready” message is received. On the other side, an unnecessary resource shortage as a result of resource reservation at the 5GS bridge for resources that are not needed is avoided. Therefore, there is an advantage that resources are used efficiently. Resources may also not be wasted due to unnecessary reservation. Furthermore, the MSRP procedure can be transparently integrated into IEEE TSN. Figure 6 shows an example method flow performed by a apparatus. The first apparatus may be comprised within a network entity. The network entity may be, for example, an SMF.

In S601 , the method comprises in response to receiving, at the apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream.

In S603, the method comprises in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

Figure 7 shows a schematic representation of non-volatile memory media 800a (e.g. computer disc (CD) or digital versatile disc (DVD)) and 800b (e.g. universal serial bus (USB) memory stick) storing instructions and/or parameters 802 which when executed by a processor allow the processor to perform one or more of the steps of the method of Figure 6. It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

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

The examples may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures, e.g., as in Figures 12 and 13, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi core processor architecture, as non-limiting examples. Alternatively or additionally some examples may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and/or method steps previously described. That circuitry may be provided in the base station and/or in the communications device. As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analogue and/or digital circuitry);

(b) combinations of hardware circuits and software, such as: (i) a combination of analogue and/or digital hardware circuit(s) with software/firmware and

(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and

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

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example integrated device. The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of some embodiments However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

Claims:

1. An apparatus comprises means for: in response to receiving, at the apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

2. The apparatus as claimed in claim 1 , wherein the means are further configured to perform: receiving, at the apparatus, the time period that network resources should be reserved for the data stream.

3. The apparatus as claimed in claim 1 , wherein the means are further configured to perform: determining, at the apparatus, the time period that network resources should be reserved for the data stream.

4. The apparatus as claimed in any of claims 1 to 3, wherein the message comprises a multiple stream registration protocol message.

5. The apparatus as claimed in claim 3, wherein the means for determining is for determining the time period based on the received information about the message.

6. The apparatus as claimed in claim 3, wherein the means for determining is for determining the time period based on user equipment subscription data available to the apparatus and stored at a unified data management entity.

7. The apparatus as claimed in claim 3, wherein the means for determining is for determining the time period based on at least one operator policy available to the apparatus stored at the policy charging function.

8. The apparatus as claimed in claim 3, wherein the means for determining is for determining the time period based on information about a resource availability of a network.

9. The apparatus as claimed in claim 3, wherein the means for determining is for determining the time period based on a value of one or more other time periods for other data streams that are active in a network.

10. The apparatus as claimed in any of claim 1 to 9, wherein the means are further configured to perform: before the time period has expired, receiving a success message indicating that data from the data stream is required by a receiving entity; and in response to the reception of the success message, discarding the time period and maintaining the protocol data unit session.

11. The apparatus as claimed in claim 10, wherein the means are further configured to perform: processing the success message to determine if the success message is linked to the first message by matching an identification of the message to an identification of the success message.

12. The apparatus as claimed in any of claim 1 to 11 , wherein the means are further configured to perform: determining at least one update for the message based on the received information so that quality of service characteristics for the data stream are met; and providing the determined at least one update to an application function, to allow the application function to perform a protocol data unit session modification.

13. The apparatus as claimed in claim 12, wherein the means are further configured to perform: storing a binding between the modified protocol data unit session, quality of service characteristics of the data stream, and the time period for reserving the network resources for the data stream.

14. The apparatus as claimed in claim 13, wherein the means for releasing the network resources is for releasing the resources by re-modifying the protocol data unit session based on the binding between the modified protocol data unit session, the quality of service of the data stream, and the time period for reserving the network resources for the data stream.

15. The apparatus as claimed in any of claims 1 , and 3 to 14, wherein the apparatus is a session management function.

16. The apparatus as claimed in any of claims 1 to 15, wherein the apparatus is comprised within a fifth-generation, 5G, bridge for a time-sensitive network.

17. The apparatus as claimed in any of claims 1 to 16, wherein the means comprises at least one processor, and at least one memory including computer program code.

18. A method, comprising: in response to receiving, at an apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.

19. The method as claimed in claim 18, comprising: receiving, at the apparatus, the time period that network resources should be reserved for the data stream.

20. The method as claimed in claim 18, comprising: determining, at the apparatus, the time period that network resources should be reserved for the data stream.

21. The method as claimed in any of claims 18 to 20, wherein the message comprises a multiple stream registration protocol message.

22. The method as claimed in claim 20, wherein the determining comprises determining the time period based on the received information about the message.

23. The method as claimed in claim 20, wherein the determining comprises determining the time period based on user equipment subscription data available to the apparatus and stored at a unified data management entity.

24. The method as claimed in claim 20, wherein the determining comprises determining the time period based on at least one operator policy available to the apparatus stored at the policy charging function.

25. The method as claimed in claim 20, wherein the determining comprises determining the time period based on information about a resource availability of a network.

26. The method as claimed in claim 20, wherein the determining comprises determining the time period based on a value of one or more other time periods for other data streams that are active in a network.

27. The method as claimed in any of claim 18 to 26, comprising: before the time period has expired, receiving a success message indicating that data from the data stream is required by a receiving entity; and in response to the reception of the success message, discarding the time period and maintaining the protocol data unit session.

28. The method as claimed in claim 27, comprising: processing the success message to determine if the success message is linked to the first message by matching an identification of the message to an identification of the success message.

29. The method as claimed in any of claim 18 to 28, comprising: determining at least one update for the message based on the received information so that quality of service characteristics for the data stream are met; and providing the determined at least one update to an application function, to allow the application function to perform a protocol data unit session modification.

30. The method as claimed in claim 29, comprising: storing a binding between the modified protocol data unit session, quality of service characteristics of the data stream, and the time period for reserving the network resources for the data stream.

31 . The method as claimed in claim 30, wherein releasing the network resources comprises releasing the resources by re-modifying the protocol data unit session based on the binding between the modified protocol data unit session, the quality of service of the data stream, and the time period for reserving the network resources for the data stream.

32. The method as claimed in any of claims 18, and 20 to 31 , wherein the method is performed by a session management function.

33. A computer program comprising computer executable instructions which when run on one or more processors perform: in response to receiving, at an apparatus, information about a message indicating a data stream, using at the apparatus a time period that network resources should be reserved for the data stream; and in response to expiration of the time period or in response to receiving a failure message, causing the reserved network resources to be released.