CN115428578B

CN115428578B - Initial access of remote devices via relay

Info

Publication number: CN115428578B
Application number: CN202080099998.9A
Authority: CN
Inventors: 于�玲; V·范潘; 许翔; G·沃尔费内
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2020-06-01
Filing date: 2020-06-01
Publication date: 2025-03-14
Anticipated expiration: 2040-06-01
Also published as: WO2021243518A1; CN115428578A

Abstract

Example embodiments of the present disclosure relate to initial access of a remote device via a relay. A first device transmits a connection request to a second device, the connection request being used to establish a control plane connection between the first device and a third device, wherein the connection request includes information of the first device used to establish a control plane connection between the first device and the third device, so that the second device can transmit the control plane connection request to the third device based on the information. The first device receives from the second device a radio resource control message transmitted by a fourth device in response to a control plane connection acceptance message from the third device. Through this solution, secure, flexible and efficient initial access of the first device is provided.

Description

Initial access of remote devices via relay

Technical Field

Embodiments of the present disclosure relate generally to the field of telecommunications and, more particularly, relate to a method, apparatus, device, and computer-readable storage medium for initial access by a remote device via a relay.

Background

As communication systems develop, more and more technologies have been proposed. In current wireless communication systems, in order to allow a terminal device to communicate with a fifth generation core (5 GC) network device, such as an access and mobility management function (AMF) or the like, a Radio Resource Control (RRC) connection needs to be established between the terminal device and a Radio Access Network (RAN) node first, and then after successful authentication and authentication of the terminal device, a Control Plane (CP) connection with a non-access stratum (NAS) level may be connected.

In current communication systems, a Side Link (SL) may be established between two devices, such as terminal devices, to enable direct communication or relay communication. Thus, the remote terminal device can access the service via the relay terminal device. Furthermore, work items are being done in the third generation partnership project (3 GPP) for SL-based relay solutions. Efficient initial access of the remote terminal device is desired.

Disclosure of Invention

In general, example embodiments of the present disclosure provide a solution for initial access by a remote device via a relay. Embodiments that do not fall within the scope of the claims, if any, are to be construed as examples useful for understanding the various embodiments of the present disclosure.

In a first aspect, a first device is provided. The first device includes at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to transmit a connection request to the second device. The connection request is for establishing a CP connection between the first device and the third device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device, such that the second device transmits the CP connection request to the third device based on the information. The first device is further caused to receive an RRC message from the second device, the RRC message for establishing an RRC connection between the first device and the fourth device. The RRC message is transmitted by the fourth device after receiving the CP connection accept message from the third device.

In a second aspect, a second device is provided. The second device includes at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to receive a connection request from the first device, the connection request for establishing a CP connection between the first device and a third device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device. The second device is further caused to transmit a CP connection request to the third device based on the information. The second device is further caused to receive an RRC message from the fourth device, the RRC message for establishing an RRC connection between the first device and the fourth device. The RRC message is transmitted after receiving the CP connection accept message from the third device. The second device is also caused to transmit an RRC message to the first device.

In a third aspect, a third device is provided. The third device includes at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to receive a CP connection request from the second device. The CP connection request is generated based on information of the first device for establishing a CP connection between the first device and the third device. The third device is further caused to transmit a CP connection accept message to the fourth device, causing the fourth device to transmit an RRC message to the second device, the RRC message being used to establish an RRC connection between the first device and the fourth device.

In a fourth aspect, a fourth device is provided. The fourth device comprises at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the fourth device to receive a CP connection accept message from the third device. The CP connection accept message is transmitted after receiving a CP connection request for establishing a CP connection between the first device and the third device from the second device. The third device is further caused to transmit an RRC message to the second device, the RRC message for establishing an RRC connection between the first device and the fourth device.

In a fifth aspect, a method is provided. The method includes transmitting, at a first device, a connection request to a second device, the connection request for establishing a CP connection between the first device and the second device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device, such that the second device transmits the CP connection request to the third device based on the information. The method also includes receiving an RRC message from the second device, the RRC message for establishing an RRC connection between the first device and the fourth device. The RRC message is transmitted by the fourth device after receiving the CP connection accept message from the third device.

In a sixth aspect, a method is provided. The method includes receiving, at the second device, a connection request from the first device, the connection request for establishing a CP connection between the first device and the third device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device. The method also includes transmitting a CP connection request to a third device based on the information. The method also includes receiving an RRC message from the fourth device, the RRC message for establishing an RRC connection between the first device and the fourth device. The RRC message is transmitted after receiving the CP connection accept message from the third device. The method also includes transmitting an RRC message to the first device.

In a seventh aspect, a method is provided. The method includes receiving, at a third device, a CP connection request from a second device from the second device. The CP connection request is generated based on information of the first device for establishing a CP connection between the first device and the third device. The method includes transmitting a CP connection accept message to the fourth device, such that the fourth device transmits an RRC message to the second device, the RRC message being used to establish an RRC connection between the first device and the fourth device.

In an eighth aspect, a method is provided. The method includes receiving, at the fourth device, a CP connection accept message from the third device. The CP connection accept message is transmitted after receiving a CP connection request for establishing a CP connection between the first device and the third device from the second device. The method includes transmitting an RRC message to the second device, the RRC message for establishing an RRC connection between the first device and the fourth device.

In a ninth aspect, a first apparatus is provided. The first device comprises means for transmitting a connection request to the second device, the connection request being for establishing a CP connection between the first device and the third device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device, so that the second device can transmit the CP connection request to the third device based on the information. The first apparatus also includes means for receiving an RRC message from the second device, the RRC message to establish an RRC connection between the first device and the fourth device. The RRC message is transmitted by the fourth device after receiving the CP connection accept message from the third device.

In a tenth aspect, a second apparatus is provided. The second device comprises means for receiving a connection request from the first device, the connection request being for establishing a control plane connection between the first device and the second device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device. The second apparatus further includes means for transmitting a CP connection request to the third apparatus based on the information. The second apparatus also includes means for receiving an RRC message from the fourth apparatus, the RRC message to establish an RRC connection between the first device and the fourth device. The RRC message is transmitted after receiving the CP connection accept message from the third device. The second apparatus also includes means for transmitting an RRC message to the first device.

In an eleventh aspect, a third apparatus is provided. The third means comprises means for receiving a CP connection request from the second device. The CP connection request is generated based on information of the first device for establishing the CP connection between the first device and the third device. The third apparatus further includes means for transmitting a CP connection accept message to the fourth device, such that the fourth device transmits an RRC message to the second device, the RRC message being used to establish an RRC connection between the first device and the fourth device.

In a twelfth aspect, a fourth apparatus is provided. The fourth means comprises means for receiving a CP connection accept message from the third device. The CP connection accept message is transmitted after receiving a CP connection request from the second device, the CP connection request being for establishing a CP connection between the first device and the third device. The fourth apparatus also includes means for transmitting an RRC message to the second device, the RRC message to establish an RRC connection between the first device and the fourth device.

In a thirteenth aspect, a computer-readable medium is provided. The computer readable medium comprises program instructions for causing an apparatus to perform at least the method according to the fifth aspect.

In a fourteenth aspect, a computer readable medium is provided. The computer readable medium comprises program instructions for causing an apparatus to perform at least the method according to the sixth aspect.

In a fifteenth aspect, a computer readable medium is provided. The computer readable medium comprises program instructions for causing an apparatus to perform at least the method according to the seventh aspect.

In a sixteenth aspect, a computer readable medium is provided. The computer readable medium comprises program instructions for causing an apparatus to perform at least the method according to the eighth aspect.

It should be understood that the summary is not intended to identify key or essential features of the embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

Some example embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure may be implemented;

Fig. 2 illustrates a conventional signaling flow for initial access of a relay-less terminal device;

fig. 3 illustrates a conventional signaling flow for establishing a PC5 direct link between a remote terminal device and a relay terminal;

Fig. 4 illustrates a conventional signaling flow for initial access of a remote terminal device via a relay terminal device;

fig. 5 illustrates a signaling flow for an initial access procedure according to some example embodiments of the present disclosure;

Fig. 6 illustrates an example CP protocol stack for L2 relay in accordance with some example embodiments of the present disclosure;

Fig. 7 illustrates yet another example CP protocol stack for L2 relay in accordance with some example embodiments of the present disclosure;

fig. 8 illustrates an example CP protocol stack for L3 relay, according to some example embodiments of the present disclosure;

fig. 9 illustrates a flowchart of a method implemented at a first device according to some other example embodiments of the present disclosure;

FIG. 10 illustrates a flowchart of a method implemented at a second device according to some other example embodiments of the present disclosure;

FIG. 11 illustrates a flowchart of a method implemented at a third device according to some other example embodiments of the present disclosure;

fig. 12 illustrates a flowchart of a method implemented at a fourth device according to some other example embodiments of the present disclosure;

FIG. 13 illustrates a simplified block diagram of an apparatus suitable for use in practicing the exemplary embodiments of this disclosure, and

Fig. 14 illustrates a block diagram of an example computer-readable medium, according to some example embodiments of the present disclosure.

The same or similar reference numbers will be used throughout the drawings to refer to the same or like elements.

Detailed Description

Principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described merely for the purpose of illustrating and helping those skilled in the art understand and practice the present disclosure and do not imply any limitation on the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

References in the present disclosure to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms "first" and "second" may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "has," "containing," and/or "having," when used herein, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

As used in this disclosure, the term "circuitry" may refer to one or more or all of the following:

(a) Pure hardware circuit implementations (such as implementations in analog and/or digital circuitry only) and

(B) A combination of hardware circuitry and software, such as (as applicable):

(i) Combination of analog and/or digital hardware circuit(s) and software/firmware

(Ii) Any portion of the hardware processor(s) with software, including the digital signal processor(s), software, and memory(s), working together to cause a device, such as a mobile phone or server, to perform various functions, and

(C) Hardware circuit(s) and/or processor(s), such as microprocessor(s) or portion of microprocessor(s), require software (e.g., firmware) to operate, but software may not exist when software is not required 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 disclosure, the term circuitry also encompasses implementations of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. For example, if applicable to the particular claim element, the term circuitry also encompasses a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular base station, or other computing or fourth device.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), long Term Evolution (LTE), LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), high Speed Packet Access (HSPA), narrowband internet of things (NB-IoT), and the like. Further, communication between the first device and the fourth device in the communication network may be performed according to any suitable generation of communication protocols, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and/or any other protocols currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. In view of the rapid development of communications, there will of course also be future types of communication technologies and systems that may embody the present disclosure. And should not be taken as limiting the scope of the present disclosure to only the above-described systems.

The term "core device" refers to any device or entity that provides access and mobility management functions, session Management Functions (SMFs), user Plane Functions (UPFs), and the like. By way of example and not limitation, the core device may be AMF, SMF, UPF or the like. In other embodiments, the core device may be any other suitable device or entity.

As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services from it. A network device may refer to a Base Station (BS) or Access Point (AP), such as a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, pico, a non-terrestrial network (NTN) or a non-terrestrial fourth device such as a satellite fourth device, a Low Earth Orbit (LEO) satellite and a Geosynchronous Earth Orbit (GEO) satellite, an aeroplane fourth device, etc., depending on the terminology and technology applied.

The term "terminal device" refers to any terminal device capable of wireless communication. By way of example, and not limitation, a terminal device may also be referred to as a communication device, user Equipment (UE), subscriber Station (SS), portable subscriber station, mobile Station (MS), or Access Terminal (AT). The terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal Digital Assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, notebook computer embedded devices (LEEs), laptop computer mounted devices (LMEs), USB dongles, smart devices, wireless client devices (CPE), internet of things (loT) devices, watches or other wearable devices, head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in an industrial and/or automated processing chain environment), consumer electronic devices, devices operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

The term "remote terminal device" refers to a terminal device that communicates with a network device and a core device via another device (i.e., a relay terminal device) outside the coverage of the network device or the core device, or for other reasons, such as being blocked by an obstacle, lacking the ability to communicate with the network device and the core device, etc.

The term "relay terminal device" refers to a terminal device that acts as a relay for a further device (e.g., a remote terminal device) to enable the further device to communicate with the network device and/or the core device.

While the functionality described herein may be performed in various example embodiments, in other example embodiments, the functionality may be performed in a fixed and/or wireless network node, and the functionality may be performed in a user equipment device (such as a cell phone or tablet or notebook or desktop or mobile IOT device or fixed IOT device). For example, the user equipment device may be suitably equipped with corresponding capabilities as described in connection with the fixed and/or wireless network node(s). The user equipment device may be a user equipment and/or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functions include a bootstrapping server function and/or a home subscriber server, which may be implemented in a user equipment device by providing the user equipment device with software configured to cause the user equipment device to execute from the point of view of these functions/nodes.

It should be understood that the term "Side Link (SL)" refers to a direct communication link and/or a discovery link between two or more terminal devices, the term "PC5" refers to an interface that enables communication and/or discovery between two or more terminal devices, and the term "PC5 direct link" refers to a link established between two or more terminal devices through a PC5 interface. The terms "side link" and "PC5 direct link" described herein are equivalent to each other.

FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure may be implemented. In the communication environment 100, the first device 110 may communicate with the second device 120 via a physical communication channel or link, the second device 120 may communicate with the third device 130 and the fourth device 140 via a physical communication channel or link, and the third device 130 may communicate with the fourth device 140 via a physical communication channel or link. In the example of fig. 1, the first device 110 and the second device are illustrated as terminal devices, wherein the first device 110 is a remote terminal device and the second device 120 is a relay terminal device. The third device 130 is illustrated as a core device serving the terminal device. The fourth device 140 is illustrated as a network device serving a terminal device. Specifically, the first device 110 communicates with the third device 130 and the fourth device 140 via the second device 120. The second device 120 communicates with the third device 130 via the fourth device 140.

It should be understood that the number of first devices, second devices, third devices, and fourth devices are for illustration purposes only and are not meant to be limiting in any way. The communication environment 100 may include any suitable number of first, second, third, and fourth devices suitable for implementing embodiments of the present disclosure.

Conventionally, in order to access a service provided by a communication system, a terminal device needs to perform a registration procedure. Fig. 2 is a conventional signaling flow 200 for initial access by a terminal device directly accessing a communication system without relay. In a conventional initial access procedure, a terminal device initiates a Random Access Channel (RACH) procedure to acquire uplink synchronization with a network device and then requests establishment of an RRC connection with the network device. After the RRC connection between the terminal device and the network device is established, a registration or service request may be sent to the core device via the established RRC connection to set up a CP connection, e.g., a non-access stratum (NAS) connection between the terminal device and the core device. However, due to the relay communication between the remote terminal device and the network device/core device, this initial access procedure cannot be reused by the remote terminal device, especially for connection establishment between the terminal device and the network device using RACH related procedures. Instead of initiating a RACH procedure for RRC connection establishment between the terminal device and the network device, the remote terminal device needs to first establish a PC5 direct link with the relay terminal device, as shown in fig. 3.

Fig. 3 shows a conventional signaling flow 300 for establishing a PC5 direct link between a remote terminal device and a relay terminal. However, the establishment procedure establishes only a connection between the remote terminal device and the relay terminal device. The connection between the remote terminal device and the network device and/or the core device still needs to be established so that the terminal device can communicate with the network device and/or the core device via the relay terminal device.

Fig. 4 illustrates a conventional signaling flow 400 for initial access of a remote terminal device via a relay terminal device. As shown in fig. 4, the relay terminal device is activated, and the remote terminal device and the relay terminal device are connected to each other via a PC5 link. As shown in fig. 4, the remote terminal device first needs to set up an RRC connection with the network device by interacting RRC signaling with the network device via the relay terminal device and then sending a registration or service request to the core device for further processing (e.g., authentication). The NAS connection of the remote terminal device may be established after further processing (e.g. successful authentication).

However, according to the conventional signaling procedure, the RRC connection between the remote terminal device and the network device must be established first, and then the CP (e.g., NAS) connection between the remote terminal device and the core device is established after successful authentication. In case the authentication is unsuccessful, the NAS connection will not be established and the pre-established RRC connection must be released. Thus, in case of authentication failure, it causes unnecessary signaling and processing overhead for RRC connection establishment. Furthermore, since all signalling between the remote terminal device and the network device and/or the core network device is relayed via the relay terminal device, the signalling overhead exchanged between the network elements is complex, which causes undesirable delays.

Thus, there is a need for a secure, flexible and efficient initial access of a remote terminal device via a relay terminal device.

According to some example embodiments of the present disclosure, a solution is provided for initial access of a remote device (such as a remote terminal device) via a relay device (such as a relay terminal device). In the initial access procedure, the remote terminal device transmits a connection request to the relay terminal device, the connection request being used to establish a CP connection between the remote terminal device and the core device. The connection request includes information of the remote terminal device for establishing the CP connection between the remote terminal device and the core device. With the above information, the relay terminal device may transmit a registration request or a service request to the remote terminal device, the registration request or the service request being used to trigger establishment of the CP connection between the remote terminal device and the core device. If the core device determines to accept the registration request or the service request after an authentication procedure for the remote terminal device, the core device may send a message to trigger the network device to initiate an RRC connection between the remote terminal device and the network device. In this way, the RRC connection may be triggered by the network side after successful authentication and the core device accepts the registration or service request. Unnecessary RRC connection establishment due to unsuccessful authentication can be avoided. In addition, through the improved process described above, the delay of initial access is shortened and the signaling overhead is reduced.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Fig. 5 illustrates a flowchart 500 of a method according to some other example embodiments of the present disclosure. Flowchart 500 may be implemented on any suitable device. For illustration purposes only, the flowchart 500 is described as being implemented at the first device 110 (such as a remote terminal device), the second device 120 (such as a relay terminal device), the third device 130 (such as a core device), and the fourth device 140 (such as a network device).

It should be understood that the number of first device 110, second device 120, third device 130, and fourth device 140 shown in fig. 5 are given for purposes of illustration and are not meant to be limiting in any way. The flowchart 500 may include any suitable number of first devices, second devices 120, third devices 130, and fourth devices 140.

The first device 110 first transmits 502 a connection request to the second device 120 over the PC5 interface, the connection request being used to establish a CP connection between the first device 110 and the third device 130. In some example embodiments, the connection request includes information of the first device 110 for establishing the CP connection between the first device 110 and the third device 130.

In some example embodiments, the information included in the connection request may be all or part of an originating NAS message that may be transmitted as an Information Element (IE) in the connection request. In this case, the connection request on the PC5 can be implemented as an extension of the current direct communication request. When the first device 110 transmits a direct communication request, the first device 110 may optionally include all or part of the IE in a legacy originating NAS message (such as a registration request, a service request, etc.) in the direct communication request information. It should be noted that the above messages are for illustration purposes only and do not imply any limitation. In other example embodiments, any suitable control message may be used.

Alternatively or additionally, the information included in the connection request may include information such as an indication of the type of NAS connection to be established (such as the type of NAS procedure requested, etc.), an Identification (ID) of the first device 110 (such as a UE ID for registration request or ProSe ID for PC5 interface, etc.), and information of the network slice (such as Network Slice Selection Assistance Information (NSSAI), etc.). In other words, the first device 110 may indicate only necessary information of the first device 110 for establishing the CP connection between the first device 110 and the third device 130.

Additionally, in some example embodiments, mutual authentication between the first device 110 and the second device 120 involving the third device 130 may be performed as shown in fig. 3. During the mutual authentication procedure, the third device 130 may provide second device 120 assistance information about the first device 110. The assistance information will assist the second device 120 in later transmission of the CP connection request to the first device 110. For example, the first device 110 provides authentication information of the first device 110 to the second device 120 to enable the second device 120 to send a request for auxiliary information to the third device 130.

In some example embodiments, the second device 120 transmits 504 a CP connection request based on information included in the connection request, the CP connection request being used to establish a CP connection between the first device 110 and the third device 130. The CP connection request is transmitted to the third device 130 via the fourth device 140.

In some example embodiments, the CP connection request is provided directly by the first device 110. For example, the CP connection request is a NAS message included in the connection request transmitted at 502. Alternatively, or in addition, the second device 120 generates a CP connection request based on the connection request. Specifically, the second device 120 extracts the information of the first device 110 included in the connection request and generates a CP connection request based on the extracted information of the first device 110. The CP connection request may contain a NAS registration request message, or a NAS service request message, or any other NAS message.

In this way, information for establishing a CP connection between the first device 110 and the third device 130 may be provided to the third device 130 so that the third device 130 may perform an authentication procedure on the first device 110.

In some example embodiments, the CP connection request may preferably be transmitted through the CP connection of the second device 120. In this way, the existing CP connection between the second device 120 and the third device 130/fourth device 140 may be utilized to exchange the necessary information of the first device 110. Accordingly, the third device 130 can obtain information of the first device 110 to authorize the first device 110 before establishing the RRC connection for the first device 110.

In this way, unnecessary signaling and processing overhead for the first device 110 may be avoided. This may also help to reduce CP connection setup procedure latency, AS different levels of CP connection signaling (such AS and NAS levels) may be combined to a greater extent into the same signaling message.

In some example embodiments, after receiving the CP connection request, the third device 130 may perform an authentication procedure for the first device 110 based on information of the first device 110 included in the CP connection request. In some example embodiments, the authentication information may be a parameter included in the connection request. Alternatively, the first device 110 may provide authentication information through other signaling or messages exchanged between the first device 110 and the second device 120. In other example embodiments, the authentication may be combined into the same authentication performed during the direct communication setup between the first device 110 and the second device 120, e.g., during mutual authentication as described in fig. 3.

Additionally, in some example embodiments, after receiving the CP connection request, if the third device 130 is not suitable to be selected for the first device 110, the third device 130 may perform a core device selection procedure (such as an existing AMF reselection function) for the first device 110.

In some example embodiments, the third device 130 may determine whether to accept the CP connection request by using the authentication procedure discussed above or other criteria (such as network load, transport layer capability, etc.). If the third device 130 determines to accept the CP connection request, the third device 130 transmits 506 a request message to the fourth device 140 to initiate an RRC connection setup procedure for the first device 110. For example, the request sent by the third device 130 may be an NG application protocol (NGAP) initial context setup request/UE context modification message to the fourth device 140 that includes a NAS message to the first device 110 (e.g., NAS registration accept message in case a registration message is received, NAS service accept in case a service request message is received, etc.). It should be noted that the above messages are shown for illustrative purposes only and do not imply any limitation. In other example embodiments, any suitable control message may be used.

Additionally, in some example embodiments, the third device 130 may support more than one relay solution (e.g., L2 relay or L3 relay) for the first device 110.

In some example embodiments, the third device 130 may support performing L2 relay for the first device 110. Fig. 6 illustrates an example CP protocol stack 600 for L2 relay between the first device 110 and the second device 120 using a 3GPP PC5 interface and fig. 7 illustrates another example CP protocol stack 700 for L2 relay between the first device 110 and the second device 120 using a non-3 GPP interface. For purposes of illustration only and not to suggest any limitation, in fig. 6 and 7, the first device 110 is a remote terminal device, the second device 120 is a relay device, the third device 130 is a core device and the fourth device 140 is a network device.

The first device 110 communicates with the second device 120 via a PC5 interface as shown in fig. 6, while the first device 110 communicates with the second device 120 via a non-3 GPP link in fig. 7 (such as WiFi or other short range radio technology). Further, as shown in fig. 6 and 7, a logical connection may be established between the first device 110 and the fourth device 140/third device 130. In these examples of CP protocol stacks for L2 relay shown in fig. 6 and 7, the CP procedure of the first device 110 having the connection mode is expected to be similar to that of a general direct connected device at least from the point of view of the network device and the core device.

Alternatively, in some example embodiments, the third device 130 may support performing L3 relay for the first device 110. Fig. 8 illustrates a CP protocol stack 800 for L3 relay. For purposes of illustration only and not to imply any limitation, the first device 110 is a remote terminal device, the second device 120 is a relay device, the third device 130-1 is a gateway or user plane function or AMF of the second device 120, the third device 130-2 is an AMF of the first device 110, and the fourth device 140 is a network device.

In the example CP protocol stack shown in fig. 8, the first device 110 and the second device 120 communicate with each other using the PC5-U protocol. The second device 120 and the fourth device 140 communicate with each other using the LTE-Uu or NR-Uu protocols. Further, as shown in fig. 8, general Packet Radio Service (GPRS) tunneling protocol (GTP) for user plane (gtpu) is used for communication between the fourth device 140 and the third device 130-1 and between the third device 130-1 and the third device 130-2. The third device 130-1 and the fourth device 140 communicate with each other using Internet Protocol (IP) or using other intermediate device(s) not shown in fig. 8

Referring again to fig. 5, in the event that more than one relay solution (such as L2 relay and L3 relay) is supported by the third device 130, the third device 130 may determine 505 a relay solution for the first device 110 and then later transmit a request message to the fourth device 140, e.g., the request message may include a CP connection accept message including the determined relay solution.

In some example embodiments, the third device 130 may determine the relay solution based on the capabilities of the first device 110 to support the relay solution. For example, if the first device 110 supports only L2 relay or L3 relay, the third device 130 may correspondingly determine that the relay scheme for the first device 110 is L2 relay or L3 relay.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on the capabilities of the second device 120 to support the relay solution. For example, if the second device 120 supports only L2 relay or L3 relay, the third device 130 may correspondingly determine that the relay scheme for the first device 110 is L2 relay or L3 relay.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on the capabilities of the fourth device 140 to support the relay solution. For example, if the fourth device 140 supports only L2 relay or L3 relay, the third device 130 may correspondingly determine that the relay scheme for the first device 110 is L2 relay or L3 relay.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on the first device 110's preference for the relay solution. For example, if the first device 110 prefers an L2 relay or an L3 relay, the third device 130 may correspondingly determine that the relay solution for the first device 110 is an L2 relay or an L3 relay.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on the preferences of the second device 120 for the relay solution. For example, if the second device 120 prefers an L2 relay or an L3 relay, the third device 130 may correspondingly determine that the relay solution for the first device 110 is an L2 relay or an L3 relay.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on subscription information of the first device 110. For example, information for the relay solution of the first device 110 may be stored as a configuration in the subscription information. The third device 130 may obtain subscription information for the first device 110 and correspondingly determine a relay solution for the first device 110.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on a type of CP connection request received (e.g., registration/NAS signaling type (e.g., initial registration or registration update)). For example, in case the CP connection request is an initial registration message, the third device 130 may determine whether a relay solution for the first device 110 is an L2 relay or an L3 relay according to the criteria discussed above, and in case the CP connection request is a registration update message, the third device 130 may determine whether the relay solution for the first device 110 is an L2 relay or an L3 relay according to the determined relay solution of the same registration.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on priority information for the service of the first device 110. For example, some priority of a service may be associated with certain service requirements. Thus, if the information of the service includes a priority corresponding to a high requirement for service continuity, the L2 relay may be determined by the third device 130, and if the information of the service includes a priority corresponding to a low requirement for service continuity, the L3 relay may be determined by the third device 130.

Alternatively or additionally, in some example embodiments, the third device 130 may determine the relay solution based on quality of service requirements for the service of the first device 110. For example, an L2 relay may correspond to a high quality of service requirement and an L3 relay may correspond to a low quality of service requirement, or vice versa. In another example embodiment, the third device 130 may determine the relay solution based on any combination of the above criteria, e.g., the capabilities of the first device 110, the capabilities of the second device 120, the capabilities of the fourth device 140, the preferences of the first device 110, the preferences of the second device 120, the subscription information of the first device 110, the type of CP connection request received, priority information for the services of the first device 110, quality of service requirements for the services of the first device 110, etc.

In some example embodiments, the determined relay solution may be explicitly indicated as an indication, e.g., the request to the fourth device may include an indication of an L2 relay or an L3 relay. In one example embodiment, the NGAP message to the fourth device may include a new Information Element (IE) to indicate the determined relay solution. In some example embodiments, the determined relay solution may be implicitly indicated. For example, a different NGAP procedure or message may be used as an implicit indication of the determined relay solution. For example, the NGAP UE context modification message may be used as an implicit indication of L3 relay. From the perspective of the fourth device 140, the fourth device 140 triggers setting up or updating the context of the second device 120 to relay traffic of the first device 110 on an L2 level or L3 level relay based on an explicit or implicit indication received from the third device 130. The NGAP initial context setup request message may be used as an implicit indication of L2 relay. After receiving the request (e.g., NGAP initial context setup request message), the fourth device 140 is triggered to set up the context for L2 relay or L3 relay of the first device 110.

In this way, in case that more than one relay solution (such as L2 relay and L3 relay) is supported, the third device 130 may determine a relay solution (such as L2 relay or L3 relay) after receiving the CP connection request from the second device 120. In this way, a more flexible initial access procedure is achieved.

After receiving the CP connection accept message from the third device 130, the fourth device 140 initiates an RRC establishment procedure for the first device 110 to establish an RRC connection between the first device and the fourth device, and associates the established RRC connection with the CP connection between the first device and the third device.

In some example embodiments, the fourth device 140 transmits 508 an RRC message (e.g., an RRC connection setup message or other RRC message (s)) to the second device, the RRC message to establish an RRC connection between the first device 110 and the fourth device 140, and then the second device 120 forwards 510 the RRC message to the first device 110. After receiving the RRC message, the first device 110 transmits 512 an RRC acknowledgement (e.g., an RRC connection setup complete message, or other RRC message (s)) to the second device 120, and then the second device 120 transmits 514 the RRC acknowledgement to the fourth device 140. In this way, RRC messages and RRC acknowledgements are transmitted between the first device 110 and the fourth device 140 via the second device 120. As a result, an RRC connection is established between the first device 110 and the fourth device 140.

In this way, RRC connection establishment is triggered by the fourth device 140. The initiation mechanism for RRC connection is more efficient in case the RRC connection is triggered only by the terminal side, as compared to the conventional initiation mechanism for RRC connection, because it is initiated only after the third device 130 determines that the CP connection between the first device 110 and the third device 130 can be established.

In addition, there are several ways to initiate an RRC connection between the first device 110 and the fourth device 140. In some example embodiments, to enable the fourth device 140 to initiate the RRC connection setup procedure, the RRC connection setup message or other RRC message(s) may be extended to include the cell radio network temporary identifier (C-RNTI) of the first device 110 in addition to the relevant radio bearer information and the relevant configuration. In other example embodiments, a new RRC message may be introduced to enable the fourth device 140 to initiate the RRC connection establishment procedure.

In some example embodiments, corresponding information regarding the CP connection setup message (e.g., registration accept message) between the first device 110 and the third device 130 may also be included in the RRC connection setup message or other RRC message(s). Alternatively, the fourth device 140 may initiate a special paging message including the C-RNTI of the first device 110 to the first device 110 via the second device 120. The special paging message triggers the first device 110 to send an RRC connection setup/re-establishment message. It should be noted that the above information is shown for illustrative purposes only and does not imply any limitation. In other example embodiments, any suitable control message may be used.

In some example embodiments, the RRC message and the special paging message for the connection setup message may be transmitted by using an existing Signaling Radio Bearer (SRB) of the second device 120, a specific RRC message of the second device 120, or a new SRB dedicated to relaying the RRC signaling message.

After receiving the RRC acknowledgement from the second device 120, the fourth device 140 transmits 516 a CP connection acknowledgement message to the third device 130 to confirm the CP connection setup of the first device 110. In some example embodiments, the fourth device 140 transmits an NGAP initial context setup response/NGAP UE context modification response to the third device 130. It should be noted that the above messages are shown for illustrative purposes only and do not imply any limitation. In other example embodiments, any suitable control message may be used.

According to the present disclosure, the existing connection between the second device 120 and the third device 130/fourth device 140 may be utilized to exchange necessary information of the first device 110 so that the third device 130 may first authenticate and authenticate the first device 110 and then trigger a CP connection setup procedure involving an RRC setup procedure. In this way, the RRC initiating mechanism is more flexible and unnecessary RRC connections due to unsuccessful authentication can be avoided. Furthermore, with the improved procedure described above, the latency of the initial access is shortened and the signaling overhead is reduced.

Further, in the case where both L2 relay and L3 relay are supported by the third device 130, the third device 130 may determine a relay solution. In this way, the relay level selection mechanism is more flexible.

Additionally, in some example embodiments, the present disclosure may be extended to support CN-initiated NAS level CP connection establishment (e.g., triggered by the AF function) after successful application authentication of the first device 110 if the first device 110 needs to be authenticated by an application function other than or in addition to cellular network authentication.

Fig. 9 illustrates a flowchart of an example method 900 implemented at the first device 110 according to some example embodiments of the present disclosure. For discussion purposes, the method 900 will be described with respect to fig. 1 from the perspective of the first device 110. It is to be appreciated that method 900 may include additional blocks not shown and/or that some of the blocks shown may be omitted, and that the scope of the present disclosure is not limited in this respect.

At 910, the first device 110 transmits a connection request to the second device 120. The connection request is used to establish a CP connection between the first device 110 and the third device 130. The connection request includes information of the first device 110 for establishing the CP connection between the first device 110 and the third device 130, such that the second device 120 transmits the CP connection request to the third device 130 based on the information.

In some example embodiments, the information includes at least one of an indication of a type of NAS connection to be established between the first device 110 and the third device 130, an identification of the first device 110, or information of a network slice requested by the first device 110.

In some example embodiments, the information is an originating NAS message included in the connection request.

In some example embodiments, the connection request is one of a direct communication request and a relay connection request, and wherein the originating NAS message is a registration request or a service request.

In some example embodiments, further comprising providing authentication information of the first device 110 to the second device 120 to enable the second device 120 to send a request to the third device 130 for assistance information for transmitting the CP connection request.

At 920, the first device 110 receives an RRC message from the second device 120, the RRC message being used to establish an RRC connection between the first device 110 and the fourth device 140.

In some example embodiments, the RRC message includes the C-RNTI of the first device 110.

In some example embodiments, the first device 110 and the second device 120 are terminal devices, the third device 130 is a core device, and the fourth device 140 is a network device.

Fig. 10 illustrates a flowchart of an example method 1000 implemented at the second device 120 according to some example embodiments of the present disclosure. For discussion purposes, the method 1000 will be described from the perspective of the second device 120 with reference to fig. 1. It should be understood that method 1000 may include additional blocks not shown and/or that some of the blocks shown may be omitted, and that the scope of the invention is not limited in this respect.

At 1010, the second device 120 receives a connection request from the first device 110 for establishing a CP connection between the first device 110 and the third device 130. The connection request includes information of the first device 110 for establishing a CP connection between the first device 110 and the third device 130.

In some example embodiments, the connection request is one of a direct communication request and a relay connection request, and the originating NAS message is a registration request or a service request.

At 1020, the second device 120 transmits a CP connection request to the third device 130 based on the information.

In some example embodiments, the second device 120 transmits the CP connection request by obtaining authentication information of the first device 110 from the first device 110, transmitting a request for auxiliary information to be used to transmit the CP connection request to the third device 130 based on the obtained authentication information, and transmitting the CP connection request to the third device 130 based on the information received from the first device 110 and the auxiliary information.

At 1030, the second device 120 receives an RRC message from the fourth device 140, the RRC message being used to establish an RRC connection between the first device 110 and the fourth device 140. The RRC message is transmitted after receiving the CP connection accept message from the third device 130.

At 1040, the second device 120 transmits an RRC message to the first device 110.

Fig. 11 illustrates a flowchart of an example method 1100 implemented at the third device 130, according to some example embodiments of the present disclosure. For discussion purposes, the method 1100 will be described with reference to fig. 1 from the perspective of the third device 130. It should be understood that method 1100 may include additional blocks not shown and/or that some of the blocks shown may be omitted, and that the scope of the disclosure is not limited in this respect.

At 1110, the third device 130 receives a CP connection request from the second device 120. The CP connection request is generated based on information of the first device 110 for establishing the CP connection between the first device 110 and the third device 130. .

At 1120, the third device 130 transmits a CP connection accept message to the fourth device 140, such that the fourth device 140 transmits an RRC message to the second device 120, the RRC message being used to establish an RRC connection between the first device 110 and the fourth device 140.

In some example embodiments, the third device 130 determines the relay solution for the first device 110 based on at least one of the first device's capability to support the relay solution, the second device 120's capability to support the relay solution, the fourth device 140's capability to support the relay solution, the first device 110's preference for the relay solution, the second device 120's preference for the relay solution, the first device 110's subscription information, the type of received CP connection request, priority information for the first device 110's service, or quality of service requirements for the first device 110's service.

In some example embodiments, the third device 130 provides the assistance information of the first device 110 to the second device 120 in response to a request from the second device 120 to enable the second device 120 to transmit the CP connection request based on the provided assistance information.

Fig. 12 illustrates a flowchart of an example method 1200 implemented at the fourth device 140, according to some example embodiments of the disclosure. For discussion purposes, the method 1200 will be described with reference to fig. 1 from the perspective of the fourth device 140. It should be understood that method 1200 may include additional blocks not shown and/or that some of the blocks shown may be omitted, the scope of the invention being not limited in this respect.

At block 1210, the fourth device 140 receives a CP connection accept message from the third device 130. The CP connection accept message is transmitted after receiving a CP connection request for establishing a CP connection between the first device 110 and the third device 130 from the second device 120.

At block 1220, the fourth device 140 transmits a CP connection accept message to the fourth device 140, such that the fourth device 140 transmits an RRC message to the second device 120, the RRC message being used to establish an RRC connection between the first device 110 and the fourth device 140.

In some example embodiments, the fourth device 140 receives a CP connection accept message including an indication of a relay solution for the first device 110, and establishes a User Plane (UP) connection between the fourth device 140 and the first device 110 based on the received relay solution for the first device 110.

In some example embodiments, a first apparatus capable of performing any of the methods 900 may include means for performing the respective operations of the methods 900. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. The first means may be implemented or comprised in the first device 110.

In some example embodiments, the first apparatus includes means for transmitting a connection request to the second apparatus, the connection request being for establishing a CP connection between the first device and the third device. The connection request includes information of the first device for establishing the CP connection between the first device and the third device, so that the second device can transmit the CP connection request to the third device based on the information. The first apparatus also includes means for receiving an RRC message from the second apparatus, the RRC message to establish an RRC connection between the first apparatus and the fourth apparatus. The RRC message is transmitted by the fourth device after receiving the CP connection accept message from the third device.

In some example embodiments, the information includes at least one of an indication of a type of non-access stratum, NAS, connection to be established between the first apparatus and the third apparatus, an identification of the first apparatus, or information of a network slice requested by the first apparatus.

In some example embodiments, the first apparatus further comprises means for providing authentication information of the first apparatus to the second apparatus to enable the second apparatus to transmit a request for assistance information for transmitting the CP connection request to the third apparatus.

In some example embodiments, the RRC message includes a C-RNTI of the first device.

In some example embodiments, the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

In some example embodiments, a second apparatus capable of performing any of the methods 1000 may include means for performing the corresponding operations of the method 1000. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. The second means may be implemented as or comprised in the second device 120.

In some example embodiments, the second apparatus includes means for receiving a connection request from the first device, the connection request being for establishing a connection between the first apparatus and the third apparatus. The connection request includes information of the first device for establishing the CP connection between the first device and the third device. The second apparatus further includes means for transmitting a CP connection request to the third apparatus based on the information. The second apparatus also includes means for receiving an RRC message from the fourth apparatus, the RRC message for establishing an RRC connection between the first apparatus and the fourth apparatus. The RRC message is transmitted after receiving the CP connection accept message from the third device. The second apparatus also includes means for transmitting an RRC message to the first apparatus.

In some example embodiments, the second apparatus includes means for obtaining authentication information of the first apparatus from the first apparatus, means for sending a request for assistance information for transmitting a CP connection request to the third apparatus based on the obtained authentication information, and means for transmitting the CP connection request to the third apparatus based on the information received from the first apparatus and the assistance information.

In some example embodiments, a third apparatus capable of performing any of the methods 1100 may include means for performing the corresponding operations of the method 1100. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. The third means may be implemented or comprised in the third device 130.

In some example embodiments, the third apparatus includes means for receiving a CP connection request from the second apparatus. The CP connection request is generated based on information of the first device for establishing the CP connection between the first device and the third device. The third apparatus further includes means for transmitting a CP connection accept message to the fourth apparatus, such that the fourth apparatus transmits an RRC message to the second apparatus, the RRC message being used to establish an RRC connection between the first apparatus and the fourth apparatus.

In some example embodiments, the third apparatus further comprises means for determining a relay solution for the first apparatus, and means for transmitting a CP connection accept message including an indication of the determined relay solution to the fourth apparatus.

In some example embodiments, the third apparatus includes means for determining a relay solution for the first apparatus based on at least one of a capability of the first device to support the relay solution, a capability of the second apparatus to support the relay solution, a capability of the fourth apparatus to support the relay solution, a preference of the first apparatus to the relay solution, a preference of the second apparatus to the relay solution, subscription information of the first apparatus, a type of the received CP connection request, priority information for a service of the first apparatus, or a quality of service requirement for a service of the first apparatus.

In some example embodiments, the third apparatus includes means for providing assistance information of the first apparatus to the second apparatus in response to a request from the second apparatus to enable the second apparatus to transmit the CP connection request based on the provided assistance information.

In some example embodiments, a fourth apparatus capable of performing any of the methods 1200 may include means for performing the corresponding operations of the method 1200. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. The fourth means may be implemented or comprised in the fourth device 140.

In some example embodiments, the fourth apparatus includes means for receiving a CP connection accept message from the third apparatus. The CP connection accept message is transmitted after receiving a CP connection request from the second device, the CP connection request being for establishing a CP connection between the first device and the third device. The fourth apparatus further comprises means for transmitting an RRC message to the second apparatus, the RRC message for establishing an RRC connection between the first apparatus and the fourth apparatus.

In some example embodiments, the fourth apparatus includes means for receiving a CP connection accept message from the third apparatus, the CP connection accept message including an indication of a relay solution for the first apparatus, and means for establishing a User Plane (UP) connection between the fourth apparatus and the first apparatus based on the received relay solution for the first apparatus.

Fig. 13 is a simplified block diagram of a device 1300 suitable for use in practicing the example embodiments of the present disclosure. The device 1300 may be used to be provided to implement a communication device, e.g., the first device 110, the second device 120, the third device 130, or the fourth device 140 as shown in fig. 1. As shown, the device 1300 includes one or more processors 1310, one or more memories 1320 coupled to the processors 1310, and one or more communication modules 1340 coupled to the processors 1310.

The communication module 1340 is used for two-way communication. The communication module 1340 has one or more communication interfaces to facilitate communications with one or more other modules or devices. The communication interface may represent any interface necessary to communicate with other network elements. In some example embodiments, the communication module 1340 may include at least one antenna.

The processor 1310 may be of any type suitable to the local technology network and may include, by way of non-limiting example, one or more of general purpose computers, special purpose computers, microprocessors, digital Signal Processors (DSPs), and processors based on a multi-core processor architecture. The device 1300 may have multiple processors, such as application specific integrated circuit chips, that are temporally slaved to a clock that is synchronized to the master processor.

Memory 1320 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read-only memory (ROM) 1324, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact Disk (CD), digital Video Disk (DVD), optical disk, laser disk, and other magnetic and/or optical storage. Examples of volatile memory include, but are not limited to, random Access Memory (RAM) 1322 and other volatile memory that does not persist during power failure.

The computer program 1330 includes computer-executable instructions that are executed by an associated processor 1310. Program 1330 may be stored in a memory, such as ROM 1324. Processor 1310 may perform any suitable actions and processes by loading program 1330 into RRM 1322.

Example embodiments of the present disclosure may be implemented by the program 1330 such that the device 1300 may perform any of the processes of the present disclosure as discussed with reference to fig. 9-12. Example embodiments of the present disclosure may also be implemented in hardware or by a combination of software and hardware.

In some example embodiments, the program 1330 may be tangibly embodied in a computer-readable medium, which may be included in the device 1300 (such as in the memory 1320) or other storage device accessible by the device 1300. The device 1300 may load the program 1330 from a computer readable medium into RAM 1322 for execution. The computer readable medium may include any type of tangible, non-volatile storage, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Fig. 14 shows an example of a computer-readable medium 1400, which may be in the form of a CD, DVD, or other optical storage disc. The computer readable medium has stored thereon a program 1330.

In general, the various example embodiments of the disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. 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. While various aspects of the example embodiments of the present disclosure are 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 present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product comprises computer executable instructions, such as those included in program modules, that are executed in a device on a target real or virtual processor to perform any of the methods described above with reference to fig. 9-12. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various example embodiments, the functionality of the program modules may be combined or split between program modules as desired. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed device, program modules may be located in both local and remote memory storage media.

Program code for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus such that the program code, when executed by the processor or controller, causes the functions/operations specified in the flowchart and/or block diagram block or blocks to be implemented. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable an apparatus, device, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are described in a particular order, this should not be construed as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Also, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate example embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple exemplary embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first device, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the first device to:

transmitting a connection request to a second device, the connection request being used to establish a control plane connection between the first device and a third device, the connection request comprising information of the first device used to establish the control plane connection between the first device and the third device, so that the second device can transmit the control plane connection request to the third device based on the information; and

A radio resource control message is received from the second device, the radio resource control message being used to establish a radio resource control connection between the first device and a fourth device, the radio resource control message being transmitted by the fourth device in response to a connection accept message from the third device.

2. The first device according to claim 1, wherein the information comprises at least one of the following:

an indication of a type of non-access stratum connection to be established between the first device and the third device,

an identification of the first device, or

Information about the network slice requested by the first device.

3. The first device of claim 1, wherein the information is an Initiate Non-Access Stratum message included in the connection request.

4 . The first device of claim 3 , wherein the connection request is one of: a direct communication request and a relay connection request, and wherein the initiating non-access stratum message is a registration request or a service request.

5. The first device of claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the first device to:

The authentication information of the first device is provided to the second device to enable the second device to send a request to the third device for auxiliary information used to transmit the control plane connection request.

6 . The first device of claim 1 , wherein the radio resource control message comprises a cell radio network temporary identifier of the first device.

7 . The first device according to claim 1 , wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

8. A second device, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the second device to:

receiving a connection request from a first device, the connection request being used to establish a control plane connection between the first device and a third device, the connection request including information of the first device used to establish the control plane connection between the first device and the third device;

Based on the information, transmitting a control plane connection request to the third device;

receiving a radio resource control message from a fourth device, the radio resource control message being used to establish a radio resource control connection between the first device and the fourth device, the radio resource control message being transmitted in response to a control plane connection accept message from the third device; and

The radio resource control message is transmitted to the first device.

9. The second device according to claim 8, wherein the information comprises at least one of the following:

an indication of a type of non-access stratum connection to be established between the first device and the third device;

an identification of the first device; or

Information about the network slice requested by the first device.

10. The second device of claim 8, wherein the information is an Initiate Non-Access Stratum message included in the connection request.

11 . The second device according to claim 10 , wherein the connection request is one of: a direct communication request and a connection relay request, and the initiating non-access stratum message is a registration request or a service request.

12. The second device of claim 8, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit the control plane connection request by:

obtaining authentication information of the first device from the first device;

Based on the acquired authentication information, sending a request to the third device for auxiliary information to be used for transmitting the control plane connection request; and

The control plane connection request is transmitted to the third device based on the information received from the first device and the auxiliary information.

13. The second device of claim 8, wherein the radio resource control message comprises a cell radio network temporary identifier of the first device.

14. The second device according to claim 8, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

15. A third device, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the third device to:

receiving a control plane connection request from a second device, the control plane connection request being generated based on the information of the first device for establishing a control plane connection between the first device and the third device; and

A control plane connection accept message is transmitted to a fourth device to enable the fourth device to transmit a radio resource control message to the second device, the radio resource control message being used to establish a radio resource control connection between the first device and the fourth device.

16. The third device of claim 15, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to transmit the control plane connection accept message by:

determining a relay solution for the first device; and

The control plane connection accept message is transmitted to the fourth device, wherein the control plane connection accept message includes the determined relay solution.

17. The third device of claim 16, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to determine a relay solution for the first device by:

Determine a relay solution for the first device according to at least one of the following:

the capability of the first device to support a relay solution;

the capability of the second device to support a relay solution;

The fourth device has the capability of supporting a relay solution;

the first device's preference for a relay solution;

the second device's preference for a relay solution;

subscription information of the first device;

a type of the control plane connection request received;

priority information for a service of said first device; or

A quality of service requirement for a service of the first device.

18. The third device according to claim 15, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the third device to:

In response to the request from the second device, the assistance information of the first device is provided to the second device, so that the second device can transmit the control plane connection request based on the provided assistance information.

19. The third device according to claim 15, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

20. A fourth device, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the fourth device to:

receiving a control plane connection accept message from the third device, the control plane connection accept message being transmitted in response to receiving a control plane connection request from the second device, the control plane connection request being used to establish a control plane connection between the first device and the third device; and

A radio resource control message is sent to the second device, where the radio resource control message is used to establish a radio resource control connection between the first device and the fourth device.

21. The fourth device of claim 20, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the fourth device to receive the control plane connection accept message by:

receiving, from the third device, the control plane connection accept message including a relay solution for the first device; and

Based on the received relay solution for the first device, a user plane connection is established between the fourth device and the first device.

22. The fourth device of claim 20, wherein the radio resource control message comprises a cell radio network temporary identifier of the first device.

23. The fourth device according to claim 20, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

24. A method comprising:

transmitting, at the first device, a connection request to the second device, the connection request being used to establish a control plane connection between the first device and a third device, the connection request comprising information of the first device for establishing the control plane connection between the first device and the third device, so that the second device can transmit the control plane connection request to the third device based on the information; and

A radio resource control message is received from the second device, the radio resource control message being used to establish a radio resource control connection between the first device and a fourth device, the radio resource control message being transmitted by the fourth device in response to a control plane connection accept message from the third device.

25. The method of claim 24, wherein the information includes at least one of:

an identification of the first device, or

Information about the network slice requested by the first device.

26. The method of claim 24, wherein the information is an Initiate Non-Access Stratum message included in the connection request.

27. The method of claim 26, wherein the connection request is one of: a direct communication request and a connection relay request, and wherein the initiating non-access stratum message is a registration request or a service request.

28. The method of claim 24, further comprising:

29. The method of claim 24, wherein the radio resource control message includes a cell radio network temporary identifier of the first device.

30. The method of claim 24, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

31. A method comprising:

receiving, at a second device, a connection request from a first device, the connection request being used to establish a control plane connection between the first device and a third device, the connection request including information of the first device used to establish the control plane connection between the first device and the third device;

The radio resource control message is transmitted to the first device.

32. The method of claim 31 , wherein the information includes at least one of:

an identification of the first device; or

Information about the network slice requested by the first device.

33. The method of claim 31, wherein the information is an Initiate Non-Access Stratum message included in the connection request.

34. The method of claim 33, wherein the connection request is one of: a direct communication request and a relay connection request, and the initiating non-access stratum message is a registration request or a service request.

35. The method of claim 31 , wherein transmitting the control plane connection request comprises:

obtaining authentication information of the first device from the first device;

Based on the obtained authentication information, sending a request to the third device for auxiliary information to be used for transmitting the control plane connection request; and

36. The method of claim 31, wherein the radio resource control message includes a cell radio network temporary identifier of the first device.

37. The method of claim 31, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

38. A method comprising:

receiving, at a third device, a control plane connection request from a second device, the control plane connection request being generated based on information of the first device for establishing a control plane connection between the first device and the third device; and

39. The method of claim 38, wherein transmitting the control plane connection accept message comprises:

determining a relay solution for the first device; and

The control plane connection accept message is transmitted to the fourth device, the control plane connection accept message including an indication of the determined relay solution.

40. The method of claim 39, wherein determining a relay solution for the first device comprises:

the capability of the first device to support a relay solution;

the capability of the second device to support a relay solution;

The fourth device has the capability of supporting a relay solution;

the first device's preference for a relay solution;

the second device's preference for a relay solution;

subscription information of the first device;

a type of the control plane connection request received;

priority information for a service of said first device; or

A quality of service requirement for a service of the first device.

41. The method of claim 38, further comprising:

42. The method of claim 38, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

43. A method comprising:

receiving, at a fourth device, a control plane connection accept message from a third device, the control plane connection accept message being transmitted in response to receiving a control plane connection request from a second device, the control plane connection request being used to establish a control plane connection between the first device and the third device; and

A radio resource control message is transmitted to the second device, where the radio resource control message is used to establish a radio resource control connection between the first device and the fourth device.

44. The method of claim 43, wherein receiving the control plane connection accept message comprises:

receiving the control plane connection accept message from the third device, the control plane connection accept message including an indication of a relay solution for the first device; and

45. The method of claim 43, wherein the radio resource control message includes a cell radio network temporary identifier of the first device.

46. The method of claim 43, wherein the first device and the second device are terminal devices, the third device is a core device, and the fourth device is a network device.

47. A first device, comprising:

means for transmitting a connection request to a second device, the connection request being used to establish a control plane connection between the first device and a third device, the connection request comprising information of the first device for establishing the control plane connection between the first device and the third device, so that the second device can transmit the control plane connection request to the third device based on the information; and

means for receiving a radio resource control message from the second device, the radio resource control message being used to establish a radio resource control connection between the first device and a fourth device, the radio resource control message being transmitted by the fourth device in response to a control plane connection accept message from the third device.

48. A second device comprising:

means for receiving a connection request from a first device, the connection request being used to establish a control plane connection between the first device and a third device, the connection request comprising information of the first device for establishing the control plane connection between the first device and the third device;

means for transmitting a control plane connection request to the third device based on the information;

means for receiving a radio resource control message from a fourth device, the radio resource control message being used to establish a radio resource control connection between the first device and the fourth device, the radio resource control message being transmitted in response to a control plane connection accept message from the third device; and

Means for transmitting the radio resource control message to the first device.

49. A third device, comprising:

means for receiving a control plane connection request from a second device, the control plane connection request being generated based on the information of the first device for establishing a control plane connection between the first device and the third device; and

Means for transmitting a control plane connection accept message to a fourth device to enable the fourth device to transmit a radio resource control message to the second device, the radio resource control message being used to establish a radio resource control connection between the first device and the fourth device.

50. A fourth device, comprising:

means for receiving a control plane connection accept message from a third device, the control plane connection accept message being transmitted in response to receiving a control plane connection request from a second device, the control plane connection request being used to establish a control plane connection between the first device and the third device; and

Means for transmitting a radio resource control message to the second apparatus, the radio resource control message being used to establish a radio resource control connection between the first apparatus and the fourth apparatus.

51. A computer-readable medium comprising program instructions for causing an apparatus to at least perform the method according to any one of claims 24 to 30, claims 31 to 37, claims 38 to 42, or claims 43 to 46.