CN115669073A

CN115669073A - Method and arrangement for use in a communication system involving a radio interface between a user equipment associated with a radio access network and another user equipment

Info

Publication number: CN115669073A
Application number: CN202080101132.7A
Authority: CN
Inventors: G·沃尔费内; 于�玲; V·范潘; 许翔; L·蒂埃博
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: 2020-05-22
Filing date: 2020-05-22
Publication date: 2023-01-31
Also published as: WO2021232435A1

Abstract

An apparatus, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

Description

Method and arrangement for use in a communication system involving a radio interface between a user equipment associated with a radio access network and another user equipment

Technical Field

The present disclosure relates to an apparatus, method and computer program, in particular but not exclusively for use in a system involving a radio interface between a user equipment associated with a radio access network and another user equipment.

Background

The communication system may involve a user equipment sending and/or receiving data and/or control signalling to a core network via a radio interface with another user equipment served by a radio access network.

Disclosure of Invention

An apparatus comprising: the method comprises preparing a message at a first user equipment, and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of the core network for the second user equipment.

The message may include at least content that is transparent to at least a core network for the second user equipment.

The message may comprise at least a layer 2 message, such AS an Access Stratum (AS) message, and the content addressed to the core network for the first user equipment comprises at least layer 3 content, such AS a non-access stratum (NAS) message. .

An apparatus comprising: means for receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and means for sending at least some of the content of the message to a core network for the second user equipment.

The content sent to the core network for the second user equipment may comprise at least content that is transparent to at least the core network for the first user equipment.

The content sent to the core network for the second user equipment may comprise layer 2 messages, such AS Access Stratum (AS) messages, and at least layer 3 content, such AS non-access stratum (NAS) messages.

The content sent to the core network for the second user equipment may comprise ethernet packet data units.

An apparatus comprising: means for receiving, at a core network for a first user equipment, a message from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and means for forwarding the message on to a radio access network for the first user equipment.

The message may include an ethernet packet data unit.

An apparatus comprising: means for receiving, at a core network for a first user equipment, a message at least via a core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and means for recovering data and/or signaling from the message.

The message may comprise at least: content transparent to the core network of the second user equipment.

The message may comprise a layer 2 message, such AS an Access Stratum (AS) message, including layer 3 content, such AS a non-access stratum (NAS) message.

The message may include an ethernet packet data unit.

An apparatus comprising: means for preparing a message for a first user equipment at a core network for the first user equipment; and means for sending the message to a core network for the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

The message may include at least content transparent to at least a core network for the second user equipment.

The messages may include at least layer 2 messages, such AS Access Stratum (AS) messages, and at least layer 3 content, such AS non-access stratum (NAS) messages.

The message may include an ethernet packet data unit.

An apparatus comprising: means for preparing a message at a first device; and means for transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

An apparatus comprising: means for receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and means for selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

An apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: preparing a message at a first user equipment, and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of the core network for the second user equipment.

The message may comprise at least a layer 2 message, such AS an Access Stratum (AS) message, and the content addressed to the core network of the first user equipment comprises at least layer 3 content, such AS a non-access stratum (NAS) message.

An apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

The content sent to the core network for the second user equipment may comprise layer 2 messages, such AS Access Stratum (AS) messages, comprising at least layer 3 content, such AS non-access stratum (NAS) messages.

An apparatus comprising: at least one processor; and the at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: receiving a message at a core network for a first user equipment from a core network of a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and forwarding the message onto the radio access network for the first user equipment.

The message may include an ethernet packet data unit.

An apparatus comprising: at least one processor; and the at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: receiving, at a core network for a first user equipment, a message via at least the core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and recovering data and/or signaling from the message.

The message may include an ethernet packet data unit.

An apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: preparing a message for a first user equipment at a core network for the first user equipment; and sending the message to a core network for the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

The message may comprise at least content that is transparent to at least the core network for the second user equipment.

The message may include at least a layer 2 message, such AS an Access Stratum (AS) message, and at least layer 3 content, such AS a non-access stratum (NAS) message.

The message may include an ethernet packet data unit.

An apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: preparing a message at a first device; and transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

An apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

One method comprises the following steps: preparing a message at a first user equipment, and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of the core network for the second user equipment.

The message may comprise at least a layer 2 message, such AS an Access Stratum (AS) message, and the content addressed to the core network for the first user equipment comprises at least layer 3 content, such AS a non-access stratum (NAS) message.

One method comprises the following steps: receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

The content sent to the core network for the second user equipment may comprise an ethernet packet data unit.

One method comprises the following steps: receiving, at a core network for a first user equipment, a message from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and forwarding the message onto the radio access network for the first user equipment.

The message may include an ethernet packet data unit.

One method comprises the following steps: receiving, at a core network for a first user equipment, a message at least via a core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and recovering data and/or signaling from the message.

The message may include an ethernet packet data unit.

One method comprises the following steps: preparing, at a core network for a first user equipment, a message for the first user equipment; and sending the message to a core network for the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

The message may include an ethernet packet data unit.

One method comprises the following steps: preparing a message at a first device; and transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

One method comprises the following steps: receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: the method comprises preparing a message at a first user equipment and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of a core network for the second user equipment.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: receiving, at a core network of a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: receiving, at a core network for a first user equipment, a message from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first device at least via a radio interface between the first user equipment and the second user equipment; and forwarding the message onto the radio access network for the first user equipment.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: receiving, at a core network for a first user equipment, a message via at least the core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and recovering data and/or signaling from the message.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: preparing, at a core network for a first user equipment, a message for the first user equipment; and sending the message to a core network for the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: preparing a message at a first device; and transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

A computer readable medium comprising program instructions, stored on the computer readable medium, for performing: receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform operations comprising: preparing a message at a first user equipment, and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of the core network for the second user equipment.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform: receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform: receiving, at a core network for a first user equipment, a message from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and forwarding the message onto the radio access network for the first user equipment.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform: receiving, at a core network for a first user equipment, a message at least via a core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and recovering data and/or signaling from the message.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform: preparing a message for a first user equipment at a core network for the first user equipment; and sending the message to a core network for the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform: preparing a message at a first device; and transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

A non-transitory computer readable medium comprising program instructions, stored thereon, to perform: receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

A computer program comprising computer executable code which, when run on at least one processor, is configured to cause an apparatus to at least: the method comprises preparing a message at a first user equipment and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of the core network for the second user equipment.

A computer program comprising computer executable code which, when run on at least one processor, is configured to cause an apparatus to at least: receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

A computer program comprising computer executable code which, when run on at least one processor, is configured to cause an apparatus to at least: receiving, at a core network for a first user equipment, a message from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first device at least via a radio interface between the first user equipment and the second user equipment; and forwarding the message onto the radio access network for the first user equipment.

A computer program comprising computer executable code which when run on at least one processor is configured to cause an apparatus to at least: receiving, at a core network for a first user equipment, a message via at least the core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and recovering data and/or signaling from the message.

A computer program comprising computer executable code which, when run on at least one processor, is configured to cause an apparatus to at least: preparing a message for a first user equipment at a core network for the first user equipment; and sending the message to a core network of the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

A computer program comprising computer executable code which, when run on at least one processor, is configured to cause an apparatus to at least: preparing a message at a first device; and transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

A computer program comprising computer executable code which, when run on at least one processor, is configured to cause an apparatus to at least: receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

A non-volatile tangible storage medium includes program instructions stored thereon for performing at least one of the above methods.

An apparatus comprising: at least one processor; and the at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: preparing a message at a first user equipment, and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of the core network for the second user equipment.

An apparatus comprising: at least one processor; and the at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform: receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and sending at least some of the content of the message to a core network for the second user equipment.

An apparatus comprising: receiving circuitry for receiving a message at a core network for a first user equipment from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and forwarding circuitry for forwarding the message onto a radio access network for the first user equipment.

An apparatus comprising: receiving circuitry for receiving a message at a core network for a first user equipment at least via a core network for a second user equipment and a radio interface between the first user equipment and the second user equipment; and recovery circuitry for recovering the data and/or signaling from the message.

An apparatus comprising: preparation circuitry to prepare a message for a first user equipment at a core network for the first user equipment; and transmit circuitry for transmitting the message to a core network for the second user equipment, wherein the first user equipment is connected to the core network for the first user equipment via the core network for the second user equipment and a radio interface between the first user equipment and the second user equipment.

An apparatus comprising: preparation circuitry to prepare a message at a first device; and transmission circuitry for transmitting the message over a radio interface between the first user equipment and the second user equipment; wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

An apparatus comprising: receiving circuitry for receiving a message via at least a radio interface between a first user equipment and a second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and selection circuitry for selecting a mobility management function entity for the second user equipment, wherein the mobility management function of the second user equipment is independent of the mobility management function of the first user equipment.

In the above, many different aspects are described. It will be appreciated that a combination of any two or more of the above aspects may provide further aspects.

Various other aspects are also described in the following detailed description and the appended claims.

Drawings

Some example embodiments will now be described in further detail, by way of example, with reference to the following examples and the accompanying drawings, in which:

FIG. 1 illustrates a representation of a system architecture according to some example embodiments;

figure 2 illustrates a representation of user plane and control plane protocol stacks in accordance with some example embodiments;

FIG. 3 illustrates a representation of a process according to some example embodiments;

fig. 4 a-4 g illustrate a method according to some example embodiments;

FIG. 5 illustrates a representation of a system architecture according to some example embodiments;

figure 6 illustrates a representation of a user plane and control plane protocol stack according to some example embodiments;

FIG. 7 illustrates a representation of a process according to some example embodiments;

FIG. 8 shows a representation of a control device according to some example embodiments;

fig. 9 shows a representation of an apparatus according to some example embodiments; and

FIG. 10 illustrates a representation of a non-volatile storage medium, according to some example embodiments.

Detailed Description

Referring to fig. 1 and 2, according to some example embodiments, one user equipment (remote UE 102) does not have its own radio interface to the radio access network and relies on the radio interface between the remote UE102 and another user equipment (relay UE 104) and the radio interface between the relay UE104 and the radio access network 106.

According to some example embodiments, the relay 104 forwards all user plane and control plane traffic of the remote UE102 to/from the remote UE102 using a layer 2 connection (e.g., an ethernet PDU (packet data unit) session).

According to some example embodiments, there is a core network for the remote UE (5G-CN remote 118) separate from the core network for the relay UE104 (5G-CN relay 116) and independent of the core network for the relay UE104 (5G-CN relay 116). The core network 116 for the relay UE includes a set of inter-operational core network entities including an access mobility function entity (AMF) 110, a Session Management Function (SMF) entity (not shown), and a user plane function entity (UPF) 108. The core network 118 for the remote UE102 also includes a separate set of interoperating core network entities, including an access mobility function entity (AMF) 114, a Session Management Function (SMF) entity (not shown), and a user plane function entity (UPF) 112.

According to some example embodiments, there is an N1 interface between the remote UE102 and the core network 118 for the remote UE. The N1 interface allows layer 3 content (e.g., non-access stratum (NAS) messages) to remain transparent to, for example, the relay UE core network 116, with content being transferred between the remote UE102 and the core network 118 of the remote UE102 via the relay UE network 116.

In fig. 1, block 120 represents a layer 2 ethernet PDU session via which layer 3 content (e.g., non-access stratum (NAS) messages) is communicated between the remote UE102 and the core network 118 of the remote UE 102.

According to some example embodiments, for traffic relayed between the relay UE104 and the UPF relay 110, a normal IP type PDU session is used instead of an ethernet type PDU session:

according to the alternative, the relay UE104 performs IP routing/NAT; the UPF relay 110 performs IP routing; the remote UE102 is assigned a local IP address; the non-access stratum (NAS) of the remote UE102 is over IP.

A remote UE attach procedure according to some example embodiments is illustrated in fig. 3.

Operation 1): according to 3gpp TS23.502, the relay UE104 creates a PDU session for the remote UE102 using PDU type ethernet.

Operation 2) a PC5 interface is created between the remote UE102 and the relay UE104, and the core network 116 for the relay UE104 assigns the AMF to the remote UE 102: the remote UE102 provides the relay UE104 with information needed to select for the remote UE102 to select the AMF via a PC5 interface (radio interface) between the remote UE102 and the relay UE. For example, one example of such information is slice information, globally Unique Temporary ID (GUTI); the relay UE104 forwards this information received from the remote UE102 to the core network of the relay UE104 via the radio interface between the relay UE104 and the radio access network (e.g., the 5G base station GnB), which enables the core network 116 of the relay UE104 to select the "remote AMF" for the remote UE 102. An entity (e.g., a policy and charging function entity) in the core network 116 of the relay UE104 selects an AMF for the remote UE102, and the core network 116 of the relay UE104 provides the relay UE104 with an ethernet MAC address of the AMF selected for the remote UE 102; and relay UE104 forwards the information to remote UE 102.

Operation 2 b): the UPF 108 of the relay UE104 configures forwarding rules for traffic between the remote UE102 and the AMF remote 118. Other examples use simple ethernet bridging without this forwarding rule.

Operation 3) the remote UE102 communicates over ethernet using NAS (via the PC5 interface (radio interface) between the remote UE102 and the relay UE104, and via the PDU session of the relay UE 104) with the AMF 114 selected for the remote UE102 in the previous operation to register (this includes authentication of the remote UE 102), and then creates a PDU session for the data traffic of the remote UE 102. From the perspective of relay UE104, RAN 106, and relay CN 116, the user data is the user data to be forwarded (NAS security protected). The AMF 114 of the remote UE102 performs the AMF tasks (including authentication, IP address assignment) of the remote UE102 and configures forwarding rules in UPF for the relay UE104 of the PDU session of the remote UE 102. Other examples use simple ethernet bridging without these forwarding rules.

Operation 4): the data session for the remote UE is forwarded via the PC5 interface (radio interface between the remote UE102 and the relay 104) and via the L2 PDU bearer for the relay UE 104. The UPF 108 for the relay UE104 and the relay UE104 may perform some mapping of QoS flows.

According to an alternative example, operation 2) involves the radio access network entity (e.g., 5G gbb) 106 selecting the AMF for the remote UE 102. The radio access network entity 106 does this selection without storing the relay UE context in the radio access network entity 106. The UPF 108 for the relay UE104 is typically close to the gNB106, and when the remote UE102 switches from the PC5 interface (the radio interface with the relay UE 104) to the Uu interface (the radio interface with the radio access network node (gNB)), the gNB to which the remote UE102 switches is not far from the gNB106 to continue serving the relay UE104, and thus the gNB106 of the relay UE104 is able to select an appropriate AMF for the remote UE 102.

If the relay UE104 enters the idle/inactive mode, the relay UE104 may be paged when downlink traffic is present for the remote UE 102.

In case of Uu or PC5 connection loss, AMF 110 for relay UE104 notifies AMF 114 of remote UE 102.

Mobility of the remote UE102 is supported in that the remote UE102 is assigned to core network entities (AMF, SMF, UPF) 112, 114 that are independent of the

core network entities

108, 110 assigned to the relay UE104, and these independent

core network entities

112, 114 assigned to the remote UE act as anchor points during mobility between the direct network connection (Uu radio interface between the remote UE102 and the RAN 106) and the relay connection (via the PC5 radio interface between the remote UE102 and the relay UE104, and the Uu radio interface between the relay UE104 and the RAN 106). This also enables relay UE104 to support remote UEs 102 that use different core networks, e.g., due to different Home Public Land Mobile Networks (HPLMNs) of remote UEs 102.

For example, the security of the core network 116 of the relay UE104 for monitoring the message content of the remote UE102 is good because the remote UE102 performs authentication with the network through NAS and the signaling between the remote UE102 and the core network 118 of the remote UE102 is NAS security protected. The control plane (NAS) connection between the remote UE102 and the core network 118 of the remote UE102, including authentication, mobility, and session management, is independent of the control plane connection between the relay UE104 and the core network 116 for the relay UE 104.

When using an ethernet type connection, the relay UE104 may avoid assigning a local IPv4 address or IPv6 prefix to the remote UE102 by performing ethernet bridging rather than IP routing and NAT.

Control and user plane traffic of the remote UE102 is forwarded in a transparent manner as user plane traffic of the relay UE104 over the ethernet (layer 2) type of PDU session of the relay UE 104.

Referring to fig. 4a, fig. 4a illustrates uplink operation of a remote UE102, according to some example embodiments.

At step 400, operations may include: the message is prepared at the remote UE 102.

At step 402, operations may include: the message is transmitted over a radio interface between the remote UE102 and the relay UE104, wherein the message includes at least content addressed to the core network 118 of the remote UE, and wherein the core network of the remote UE is independent of the core network used for the relay UE.

According to some example embodiments, the message includes at least content that is transparent to at least the core network for the relay UE 104.

According to some example embodiments, the message comprises at least a layer 2 message, such AS an Access Stratum (AS) message, and the content addressed to the core network 118 of the remote UE102 comprises at least layer 3 content, such AS a non-access stratum (NAS) message.

Referring to fig. 4b, fig. 4b illustrates uplink operation of the core network 116 for the relay UE104, according to some example embodiments.

At step 404, the operations may include: the message is received at the core network 116 for the relay UE at least via a radio interface between the relay UE104 and the remote UE 102.

At step 406, the operations may include sending at least some of the content of the message to the core network 118 for the remote UE 102.

According to some example embodiments, the content sent to the core network 118 for the remote UE102 includes at least content that is transparent to at least the core network 116 for the relay UE 104.

According to some example embodiments, the content sent to the core network 118 for the remote UE102 includes layer 2 messages, such AS Access Stratum (AS) messages, and at least layer 3 content, such AS non-access stratum (NAS) messages.

According to some example embodiments, the content transmitted to the core network 118 for the remote UE102 includes ethernet packet data units.

Referring to fig. 4c, fig. 4c illustrates downlink operation of the core network 116 for the relay UE104, according to some example embodiments.

At step 408, the operations may include: the message is received at the core network 116 for the relay UE104 from the core network 118 for the remote UE102, wherein the remote UE102 is connected to the core network 116 for the relay UE104 via at least a radio interface between the relay UE104 and the remote UE 102.

At step 410, the operations may include: the message is forwarded to the radio access network 106 for relaying the UE 104.

According to some example embodiments, the message comprises an ethernet packet data unit.

Referring to fig. 4d, fig. 4d illustrates uplink operation of the core network 118 for the remote UE102, according to some example embodiments.

At step 412, the operations may include: the message is received at the core network 118 for the remote UE102 via at least the core network 116 for the relay UE104 and a radio interface between the remote UE102 and the relay UE 104.

At step 414, the operations may include recovering data and/or signaling from the message.

According to some example embodiments, the message includes at least content that is transparent to at least the core network 116 for the relay UE.

According to some example embodiments, the message comprises a layer 2 message, such AS an Access Stratum (AS) message, and layer 3 content, such AS a non-access stratum (NAS) message.

Referring to fig. 4e, fig. 4e illustrates downlink operation of the core network 118 for the remote 102, in accordance with some example embodiments.

At step 416, the operations may include: the message is prepared for the remote UE102 at the core network 118 for the remote UE 102.

At step 418, the operations may include: the message is sent to the core network 116 for the relay UE104, where the remote UE102 is connected to the core network 118 for the remote UE102 via the core network 116 for the relay UE104 and a radio interface between the remote UE102 and the relay 104.

According to some example embodiments, the message includes at least content that is transparent to at least the core network 116 of the relay UE 104.

According to some example embodiments, the messages comprise at least layer 2 messages, such AS Access Stratum (AS) messages, and at least layer 3 content, such AS non-access stratum (NAS) messages.

Referring to fig. 4f, fig. 4f illustrates operation of the remote UE102 according to some example embodiments.

At step 420, the operations may include preparing the message at the remote UE 102.

At step 422, the operations may include transmitting the message over a radio interface between the remote UE102 and the relay UE104, wherein the message includes information for selecting a mobility management function entity for the remote UE 102.

Referring to fig. 4g, fig. 4g illustrates operation of the core network 116 of the relay UE104 according to some example embodiments.

At step 424, the operations may include receiving a message including information for selecting a mobility management function entity for the remote UE102 via at least the core network 116 for the relay UE104 and a radio interface between the remote UE and the relay UE.

At step 426, the operations may include: a mobility management function entity is selected for the remote UE102, wherein the mobility management function for the remote UE102 is independent of the mobility management function for the relay UE 104.

According to some example embodiments, the ProSe 5G UE-to-network relay entity 102 (relay UE) provides functionality to support connection of remote UEs to the network for both public safety services and business services (e.g., interactive services) (see fig. 5). The remote UE102 successfully establishes a PC5 link to the relay UE 104. The remote UE102 may be within NG-RAN coverage or outside NG-RAN coverage.

Some example embodiments provide traffic confidentiality (e.g., when not provided by higher layers/application layers), and ip @ protection in mobility between direct 5GC access (through Uu connected to NG RAN) and 5GC access via relay UE 104.

Some example embodiments reuse untrusted access to a 5G core network (5 GC), which may be reused for 5G core network (5 GC) access to a Public Land Mobile Network (PLMN) via an independent non-public network (SNPN) entity and a non-3 GPP interworking function (N3 IWF) entity. According to some example embodiments, the N3IWF entity handles the 5G Prose remote UE102 in the same way as a non-3 GPP (N3 GPP) UE.

Fig. 6 illustrates a representation of a protocol stack for N3IWF enabled ProSe 5G UE-to-network relay, according to some example embodiments.

Some example embodiments relate to IP version 4 processing. Relay UE104 allocates ip @ to remote UE 102; the relay UE104 performs NAPT (network address and port translation) between the PC5 and Uu. For Downlink (DL) traffic, it uses ports above IP to determine the PC5 address and link (remote UE 102) to use. The relay UE104 does not know whether it relays UP or CP for the remote UE 102.

Some example embodiments relate to IP version 6 processing. Relay UE104 provides the IP prefix to remote UE 102; relay UE104 may use PD (prefix delegation) to obtain prefixes for allocation to remote UE(s) 102. The relay UE104 acts as a request router.

According to some example embodiments, the core network 116 with which the relay UE104 is registered and the core network 118 with which the remote UE102 is registered correspond to the same PLMN.

According to some example embodiments, the core network 116 with which the relay UE104 is registered and the core network 118 with which the remote UE102 is registered correspond to different PLMNs.

According to some example embodiments, RAN transparency of the remote UE to the RAN 106 ensures that: confidentiality of data traffic of the remote UE102 without interception by the relay UE104, and/or the possibility of reserving an IP address for the remote UE102 when the remote UE102 moves between (i) PC5 access via the relay UE104 and (ii) local direct Uu access to the 5G system (5 GS) without relaying.

According to some example embodiments, the operation is transparent to the NG RAN 106. NG RAN (gNB) 106 and UPF 108 of relay UE104 are unaware of the relay operation of remote UE 102.

Fig. 7 illustrates a representation of a connection of a remote UE102 via a relay UE104, according to some example embodiments.

Operation 0: the relay UE104 and the remote UE102 are provisioned for UE-to-NW relay, including use of and relay operation provisioning for the baseline PC 5. The supplied information may include at least information of the N3IWF, policies for using the N3IWF, security parameters, and the like.

Operation 1: the relay UE104 registers with the 5G core network, which may follow the registration procedure specified in TS 23.502.

Operation 2: the remote UE102 discovers and selects the relay UE104 and establishes a connection for one-to-one ProSe direct communication.

Operation 3: the remote UE102 requests ProSe 5G UE-to-network relay operation. A relay authorization procedure may be performed.

And operation 4: if the 5G relay UE104 does not have the required PDU session that can support the PC5 connection with the remote UE102, including the appropriate single network slice selection assistance information (S-NSSAI), data Network Name (DNN), and quality of service (QoS) parameters, the relay UE104 will initiate PDU session setup to relay the traffic of the remote UE 102. The trigger to establish the dedicated PDU session may be a first PC5 setup request from the remote UE 102. The PDU session announcement criteria may be the announcement of the last PC5 of the remote UE 102.

Operation 5: the remote UE is assigned an IPv6 prefix and/or an IPv4 address. After this step, uplink and downlink data relaying may begin. The remote UE102 obtains the local IP address from the relay UE104 according to an L3 procedure, where the relay UE104 acts as a Dynamic Host Configuration Protocol (DHCP) server (or stateless auto-configuration (SLAAC) router or prefix delegation router for IPv 6) and NAPT. The relay UE104 may implement NAPT between PC5 and Uu. For DL traffic, the relay UE104 determines the PC5 address and link to use (remote UE 102) using a transmission control protocol/user datagram protocol (TCP/UDP) port. The relay UE104 holds a mapping table between the local IP address and the PC5 link because the relay UE104 can act as a relay for multiple remote UEs 102.

From here on, the remote UE signaling procedure for its N3IWF runs in operation 4 on top of the PDU session established by the relay UE104 and using the IP address information negotiated in operation 5.

Operation 6: the remote UE102 determines whether service by the N3IWF is required. This decision may be UE dependent implementation, or may be controlled by local policy (which may take into account application level encryption mechanisms and application level IP mobility requirements), and/or by operator policy configured in the remote UE and/or by information or instructions received from the relay UE 104.

Operation 7a: the remote UE102 discovers the N3IWF using DNS lookup or using configured N3IWF information.

Operation 7b: the remote UE102 connects to the N3IWF selected in operation 7a for Internet Key Exchange (IKE) establishment.

Operation 7c: the remote UE102 registers with the core network (5 GC) via the selected N3IWF. The N3IWK treats the remote UE access as an N3GPP access. Thus, the remote UE authenticates via its own credentials.

Operation 8: the remote UE102 establishes a data connection through the registered N3IWF access. The remote UE102 may establish one or more PDU sessions or move an existing PDU session as follows. The remote UE102 may establish one or more new PDU sessions. Based on the mobility of the remote UE102 using the PDU session used before the relay, the remote UE102 may proceed according to a PDU session mobility procedure. The remote UE registers via the N3IWF and establishes a PDU session. According to some example embodiments, IPsec is used for both NAS and UP traffic of remote UE102, and both NAS and UP traffic of remote UE102 are hidden from relay UE 104.

IKE, which remains active between the remote UE102 and the N3IWF 122, may be used to detect possible path failure.

When the remote UE102 and N3IWF 122 support IKEv2 mobile and multihoming protocol (MOBIKE), mobility of the remote UE102 between different relay UE(s) may be supported. This is negotiated between the remote UE102 and the N3IWF 122.

Fig. 8 illustrates an example of a control apparatus 900 at any entity for the RAN 106 and

core networks

116, 118, such as the

AMF entities

110, 114 and

UPF entities

108, 112. The control device may include at least one Random Access Memory (RAM) 911a, at least one Read Only Memory (ROM) 911b, at least one

processor

912, 913 and an input/output interface 914. At least one

processor

912, 913 may be coupled to RAM 911a and ROM 911b. The at least one

processor

912, 913 may be configured to execute appropriate software code 915. For example, software code 915 may allow one or more steps to be performed to perform one or more operations described above. The software code 915 may be stored in the ROM 911b. A control device 900 at one of the entities may be interconnected with another control device 900 at one or more of the entities.

Fig. 9 illustrates an example of a user equipment or terminal 1000, such as the user equipment described above. Terminal 1000 can be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a Mobile Station (MS) or mobile device such as a mobile phone or so-called "smartphone," a computer equipped with a radio interface card or other radio interface facility (e.g., a USB dongle), a Personal Data Assistant (PDA) or tablet equipped with wireless communication capabilities, a Machine Type Communication (MTC) device, an internet of things (IoT) type communication device, or any combination of these or similar devices. For example, terminal 1000 can provide data communication for bearer communication. The communication may be one or more of voice, electronic mail (email), text messages, multimedia, data, machine data, and so on.

Terminal 1000 can receive signals over the air or radio interface 1007 via appropriate means for receiving and can transmit signals via appropriate means for transmitting radio signals. In fig. 10, a module 1006 schematically designates a transceiver device. For example, the transceiver device 1006 may be provided by a radio and associated antenna arrangement. The antenna arrangement may be arranged inside or outside the mobile device.

Terminal 1000 can be provided with at least one processor 1001, at least one memory ROM 1002a, at least one RAM 1002b, and possibly other components 1003 for software and hardware assisted execution of tasks it is designed to perform, including controlling access to and communication with access systems and other communication devices. At least one processor 1001 is coupled to a RAM 1011a and a ROM 1011b. The at least one processor 1001 may be configured to execute suitable software code 1008. For example, the software code 1008 may allow for performing one or more aspects of the present disclosure. The software code 1008 may be stored in the ROM 1011b.

The processor, memory and other associated control devices may be provided in an appropriate circuit board and/or chipset. This feature is denoted by reference numeral 1004. The device may optionally have a user interface such as a keyboard 1005, a touch screen or keyboard, combinations thereof, or the like. Optionally, one or more of a display, a speaker and a microphone are provided, depending on the type of device.

Fig. 10 shows a schematic diagram of a non-volatile storage medium 1100a (e.g., a computer Compact Disc (CD) or a Digital Versatile Disc (DVD)) and 1100b (e.g., a Universal Serial Bus (USB) memory stick) that store instructions and/or parameters 1102 that, when executed by a processor, allow the processor to perform one or more steps of the above-described method.

It should be noted that embodiments of the present invention may be implemented as circuitry in software, hardware, application logic or a combination of software, hardware and application logic. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" can be any medium or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer or smart phone or user device.

As used in this application, the term "circuitry" refers to all of the following: (a) Hardware-only circuit implementations (such as implementations in analog-only and/or digital circuitry only), and (b) combinations of circuits and software (and/or firmware), such as (as applicable): (i) A combination of processor(s), or (ii) processor (s)/software (including digital signal processor(s), software, and portions of memory(s) that work together to cause a device, such as a mobile phone or server, to perform various functions, and (c) circuitry, such as a microprocessor(s) or a portion of a microprocessor(s), that requires software or firmware for operation, even if the software or firmware is not physically present. This definition of "circuitry" applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" shall also cover (e.g., if applicable to the particular claim element) a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or other network device.

The described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. Those of ordinary skill in the art will readily appreciate that the invention as described above may be practiced with steps in a different order and/or with hardware elements in configurations other than those disclosed. Thus, while the invention has been described based upon these preferred embodiments, certain modifications, variations, and alternative constructions will become apparent to those skilled in the art while remaining within the spirit and scope of the invention.

Claims

1. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform:

preparing a message at a first user equipment and transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of a core network for the second user equipment.

2. The apparatus of claim 1, wherein the message comprises at least: content transparent to at least the core network for the second user equipment.

3. An apparatus according to claim 1 or 2, wherein the message comprises at least a layer 2 message and the content addressed to the core network for the first user equipment comprises at least layer 3 content.

4. An apparatus, comprising:

at least one processor; and

receiving, at a core network for a first user equipment, a message via at least a radio interface between the first user equipment and a second user equipment; and

sending at least some of the content of the message to the core network for the second user equipment.

5. The apparatus of claim 4, wherein the content sent to the core network for the second user equipment comprises at least: content transparent to at least the core network for the first user equipment.

6. An apparatus according to claim 4 or 5, wherein the content sent to the core network for the second user equipment comprises at least layer 3 content.

7. An apparatus according to claim 4 or 5, wherein the content sent to the core network for the second user equipment comprises Ethernet packet data units.

8. An apparatus, comprising:

at least one processor; and

receiving, at a core network for a first user equipment, a message from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and

forwarding the message onto a radio access network for the first user equipment.

9. The apparatus of claim 8, wherein the message comprises an ethernet packet data unit.

10. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform:

preparing a message at the first device; and

transmitting the message over the radio interface between the first user equipment and the second user equipment;

wherein the message comprises information for selecting a mobility management function entity for the first user equipment.

11. The apparatus of claim 4, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform:

receiving a message at least via the radio interface between the first user equipment and the second user equipment, the message comprising information for selecting a mobility management function entity for the second user equipment; and

selecting a mobility management function entity for the second user equipment, wherein the mobility management function for the second user equipment is independent of a mobility management function for the first user equipment.

12. A method, comprising:

preparing a message at a first user equipment, an

Transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of a core network for the second user equipment.

13. A method, comprising:

14. A method, comprising:

15. A computer readable medium comprising program instructions stored thereon for performing:

preparing a message at a first user equipment, an

16. A computer readable medium comprising program instructions, stored thereon, for performing:

17. A computer readable medium comprising program instructions, stored thereon, for performing:

18. An apparatus, comprising:

means for preparing a message at a first user equipment, an

Means for transmitting the message over a radio interface between the first user equipment and a second user equipment, wherein the message comprises at least content addressed to a core network for the first user equipment, and wherein the core network for the first user equipment is independent of a core network for the second user equipment.

19. An apparatus, comprising:

means for receiving, at a core network for a first user equipment, a message at least via a radio interface between the first user equipment and a second user equipment; and

means for sending at least some of the content of the message to the core network for the second user equipment.

20. An apparatus, comprising:

means for receiving a message at a core network for a first user equipment from a core network for a second user equipment, wherein the second user equipment is connected to the core network for the first equipment at least via a radio interface between the first user equipment and the second user equipment; and

means for forwarding the message on to a radio access network for the first user equipment.