Method and apparatus for sidelink resource control

Aspects of the disclosure provide methods, apparatuses and systems for wireless communication. In some embodiments, a wireless communication system includes processing circuitry. The processing circuitry of the wireless communication system operates based on a first radio access technology. The processing circuitry receives a sidelink control request from a first user equipment that accesses the wireless communication system using the first radio access technology. The sidelink control request requests sidelink control information for a second radio access technology. The processing circuitry then obtains the sidelink control information for the second radio access technology, and provides, via the first radio access technology, the sidelink control information for the second radio access technology, to the first user equipment. The sidelink control information is used to configure a sidelink between the first user equipment and a second user equipment using the second radio access technology.

BACKGROUND

Wireless communication systems can provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. With continuous developments of wireless communication technologies, multiple radio access technologies that adopt different telecommunication standards may co-exist. For example, new radio (NR), which is also referred to as fifth generation (5G), is new radio access technology (RAT) beyond Long Term Evolution (LTE) which is also referred to as fourth generation (4G). NR may coexist with LTE during network deployments of the new generation.

SUMMARY

Aspects of the disclosure provide methods, apparatuses and systems for wireless communication. In some embodiments, a wireless communication system includes processing circuitry. The processing circuitry of the wireless communication system operates based on a first radio access technology. The processing circuitry receives a sidelink control request from a first user equipment that accesses the wireless communication system using the first radio access technology. The sidelink control request requests sidelink control information for a second radio access technology. The processing circuitry then obtains the sidelink control information for the second radio access technology, and provides, via the first radio access technology, the sidelink control information for the second radio access technology, to the first user equipment. The sidelink control information is used to configure a sidelink between the first user equipment and a second user equipment using the second radio access technology.

In some examples, the first radio access technology is evolved universal terrestrial radio access (E-UTRA) technology, and the second radio access technology is new radio (NR) technology. In some examples, the first radio access technology is new radio (NR) technology, and the second radio access technology is evolved universal terrestrial radio access (E-UTRA) technology.

In an embodiment, the processing circuitry communicates with another wireless communication system configured based on the second radio access technology to obtain the sidelink control information for the second radio access technology.

In another embodiment, the processing circuitry acquires, from a control function server in the wireless communication system, sidelink control information for the first radio access technology. The processing circuitry communicates with another wireless communication system to provide the sidelink control information for the first radio access technology to the other wireless communication system. The other wireless communication network provides, using the second radio access technology, the sidelink control information for the first radio access technology to the second user equipment to enable the second user equipment to configure the sidelink between the first user equipment and the second user equipment using the first radio access technology.

In some embodiments, the processing circuitry provides sidelink control information for the first radio access technology to an application function (AF) server system. The AF server system provides the sidelink control information for the first radio access technology to the first user equipment and the second user equipment via channels in an application layer. The sidelink control information for the first radio access technology is used to configure a sidelink between the first user equipment and the second user equipment using the first radio access technology.

Aspects of the disclosure provide methods for an application function server system to control sidelink resource. In some embodiments, an application function (AF) server system receives sidelink control information for a first radio access technology from a first network configured based on the first radio access technology. Then, the AF server system coordinates with a first user equipment that accesses the first network using the first radio access technology, and a second user equipment that accesses a second network using a second radio access technology, via channels in an application layer. The AF server system provides the sidelink control information for the first radio access technology to the first user equipment and the second user equipment using the channels in the application layer for configuring a sidelink between the first user equipment and the second user equipment.

In some examples, the first radio access technology and the second radio access technology are evolved universal terrestrial radio access (E-UTRA) technology and new radio (NR) technology respectively.

In an embodiment, the AF server system receives sidelink control information for the radio access technology from the second network configured based on the first radio access technology. The AF server system can provide the sidelink control information for the second radio access technology to the first user equipment and the second user equipment using the channels in the application layer for configuring the sidelink between the first user equipment and the second user equipment.

In an example, the AF server system encrypts the sidelink control information for the first radio access technology in a message to be transmitted via the channels in the application layer.

Aspects of the disclosure also provide methods for sidelink resource control in user equipment. In some examples, a first user equipment establishes a radio connection with a first network using a first radio access technology. The first user equipment discovers a second user equipment that accesses a second network using a second radio access technology. The first user equipment sends a request to the first network that requests sidelink control information for the second radio access technology. Then, the first user equipment receives wireless signals in the first radio access technology that carries the sidelink control information for the second radio access technology. The sidelink control information for the second radio access technology is sourced from the second network in an example.

DETAILED DESCRIPTION OF EMBODIMENTS

Aspects of the disclosure provide techniques of radio resource control for cross-radio access technology (RAT) scenarios. In some embodiments, the techniques of radio resource control are used for controlling sidelink radio resources for wireless communication of user data directly between two devices without going through a base station, such as vehicle to vehicle (V2V) communication, vehicle to pedestrian (V2P) communication, vehicle to device (V2D) communication, user equipment to user equipment communication, cell phone to cell phone communication, device to device (D2D) wireless communication, and the like. While V2V wireless communication is used as examples in the present disclosure, the examples can be suitably modified for other sidelink communication scenarios, such as vehicle to everything (V2X) communication, vehicle to pedestrian (V2P) communication, vehicle to device (V2D) communication, user equipment to user equipment communication, cell phone to cell phone communication, and the like.

In a cross-RAT scenario, two vehicles are respectively connected into two radio access networks with different radio access technologies. In some embodiments, a first vehicle is connected into an evolved packet system (EPS) that is deployed based on LTE technology, and a second vehicle is connected into a 5G system (5GS) that is deployed based on NR technology. In some examples, the EPS is deployed with evolved packet core (EPC) network and evolved universal terrestrial radio access (E-UTRA) network for air interface; and the 5GS is deployed with 5G core (5GC) network and 5G access network for air interface. To enable sidelink communication of user data directly between the two vehicles without going through base stations, coordination of sidelink resource control over the EPS and 5GS are performed in some examples. In some embodiments, the coordination of the sidelink resource control is through an application server system.

FIG. 1shows a diagram of a cross-RAT wireless communication system100according to some embodiments of the disclosure. The cross-RAT wireless communication system100includes two access networks that are respectively connected to two core networks. Coordination over the two core networks are performed for sidelink resource control to enable sidelink communication between two user devices, such as two vehicles that are respectively connected to the two radio access networks.

Specifically, in theFIG. 1example, the cross-RAT wireless communication system100includes a first sub-system110and a second sub-system140. In some examples, the first sub-system110is an EPS110that is configured based on LTE technology, and the second sub-system140is a 5GS140that is configured based on the NR technology. For example, the EPS110includes an evolved packet core (EPC) network120and an evolved universal terrestrial radio access network (E-UTRAN)130for air interface, and the 5GS140includes a 5G core 5GC) network150and a next generation (NG) radio access network (NG-RAN)160for air interface. It is noted that the cross-RAT wireless communication system100can include other suitable sub-systems, such as an application server system170and the like. The sub-systems110,140and170are suitably connected, for example by Internet, and the like to enable control signals and/or data communication among the sub-systems.

The E-UTRAN130includes one or more base stations that air-interface with user equipment using LTE technology and can provide control plane and user plane to user equipment. The base stations in the E-UTRAN130are generally fixed stations that communicate with the user equipment and are also referred to as other suitable terminology, such as evolved node-B (eNB), a base transceiver system, an access point and the like.

The NG-RAN160includes one or more base stations that air-interface with user equipment using NR technology and can provide control plane and user plane to user equipment. The base stations in the NG-RAN160are generally fixed stations that communicate with the user equipment and are also referred to as other suitable terminology, such as next generation Node-B (gNB), a base transceiver system, an access point and the like.

According to some aspects of the disclosure, a first user equipment (UE)180and a second UE190are respectively connected into the EPS110and the 5GS140. For example, the first UE180is connected with the EPC120via the E-UTRAN130, and the second UE190is connected with the 5GC150via the NG-RAN160. In theFIG. 1example, the first UE180is connected into the EPS110via an eNB131, and the second UE190is connected into the 5GS140via a gNB161.

Further, according to some aspects of the disclosure, the first UE180and the second UE190may perform data communication directly via a sidelink without going through a base station. In an example, both the first UE180and the second UE190support LTE technology and NR technology, and may communicate directly over a LTE sidelink or an NR sidelink based on coordination of the EPS110and 5GS140in the cross-RAT wireless communication system100. In another example, the first UE180supports LTE technology, and the second UE190supports both LTE and NR technology, and the first UE180and the second UE190may communicate directly over a LTE sidelink based on coordination of the EPS110and 5GS140in the cross-RAT wireless communication system100. In another example, the first UE180supports both LTE technology and NR technology, and the second UE190supports the NR technology, and the first UE180and the second UE190may communicate directly over an NR sidelink based on coordination of the EPS110and 5GS140in the cross-RAT wireless communication system100. In some embodiments, the coordination oft the EPS110and 5GS140may go through a third party, such as the application server system170and the like.

It is noted that, in theFIG. 1example, wireless signals in the LTE technology is shown with thin dash lines, and wireless signals in the NR technology is shown with thick dash lines.

The first UE180and the second UE190can be any suitable fixed devices or mobile devices, and may be referred to as other suitable terminology, such as mobile stations, user terminals, wireless devices, and the like. Following description uses a first vehicle180and a second vehicle190as an example of the first UE180and the second UE190, and the description can be modified to suit for other devices.

The EPC network120includes various network elements. In some examples, the EPC network120includes a mobility management entity (MME)122, serving gateways (not shown), packet data network (PDN) gateways (not shown), and some other network elements such as vehicle to everything control function (V2X-CF)121, and the like.

It is noted that, in an example, each network element in the EPC network120can be implemented as circuits (e.g., processing circuitry, memory circuitry, input/output circuitry, and the like) or can be implemented as a processor that operates based on software instructions. In another example, a network element can be implemented as a server system with multiple servers. The multiple servers can be disposed at a location or can be distributed at different locations and are connected to work together as to appear as a single server to for example, user equipment. In another example, multiple network elements can be implemented by one physical component.

The serving gateways and the PDN gateways are configured for handling the user plane, such as transport data traffic between the user equipment and external networks of the EPS110. The serving gateways are the points of interconnection between the E-UTRAN130and the EPC network120. The serving gateways serve the user equipment by routing the incoming and outgoing IP packets in an example. The PDN gateways are the points of interconnection between the EPC network120and the external IP networks. The PDN gateways route packets to and from the packet data networks for example.

In some examples, the MME122is configured to handle with the control plane. For example, the MME122handles the signaling related to mobility and security for accessing E-UTRAN130.

It is noted that, in some examples, the MME122and the serving gateways are combined into a network element for performing both functions.

The V2X-CF121is a network element for managing vehicle to everything (V2X) related services in a network. In an example, the V2X-CF assists with network relation actions, such as providing the user equipment (e.g., vehicle, terminal device, smart phone, and the like) with the parameters necessary to use V2X communications.

According to an aspect of the disclosure, the 5GC network150includes various service functions for providing services. In some examples, the 5GC network150includes a core access and mobility management function (AMF)152, policy control function (PCF)151, user plane function (UPF) (not shown), session management function (SMF) (not shown) and some other service functions, and the like. In an example, an application function (AF) is implemented as part of the operator network and thus in the 5GC network150. In another example, an AF is implemented in the domain of a third party, such as in the application server system170, in user equipment, and the like.FIG. 1shows that the application server system170includes an AF171.

It is noted that, in an example, each function in the 5GC network150can be implemented in circuits (e.g., processing circuitry, memory circuitry, input/output circuitry, and the like) or can be implemented as a processor that operates based on software instructions. In another example, a function can be implemented as a server system with multiple servers. The multiple servers can be disposed at a location or can be distributed at different locations and are connected to work together as to appear as a single server to external components, such as user equipment. In another example, multiple functions can be performed by one physical component.

In some examples, the UPF combines the functions of the serving gateways and the PDN gateways in the LTE technology.

In some examples, the AMF152receives connection and session related information from user equipment and is responsible for handling connection and mobility management tasks. It is noted that messages related to session management are forwarded to the SMF, and handled by the SMF.

In some examples, the PCF151provides policy rules for control plane functions, such as network slicing, roaming and mobility management. Further, the PCF151can access subscription information for policy decisions, and supports the quality of service (QoS) policy and charging control functions. In an example, the PCF151can provide sidelink resource policy and configuration parameters. It is noted that, in another example, the sidelink resource policy and configuration parameters can be provided by other suitable function in the 5GC network150.

In some embodiments, user equipments use valide V2X policy and parameters provisioned by core networks for sidelink communication. For example, the V2X CF121can provide V2X policy and parameters for configuring LTE sidelinks for V2X communication; and the PCF151can provide V2X policy and parameters for configuring NR sidelinks for V2X communication.

According to an aspect of the disclosure, the EPC network120and the 5GC network150coordinate to provide suitable V2X policy and parameters to enable cross RAT radio resource control on the sidelink communication between the first UE180and the second UE190. Some coordination procedures for cross-RAT sidelink control are shown inFIG. 2andFIG. 3.

According to another aspect of the disclosure, the coordination of the EPC network120and the 5GC network150for providing suitable V2X policy and parameters go through the AF171. In an example, the application server system170is a vehicle application server system170that provides V2X communication service. Some coordination procedures for cross-RAT sidelink control are shown inFIG. 4andFIG. 5. It is noted that the application server system170can include one or more servers. The one or more servers can be disposed at one location, or can be distributed at different locations and are suitably connected.

FIG. 2shows an example of a coordination procedure200in the cross-RAT wireless communication system100according to an embodiment of the disclosure. The coordination procedure200enables the cross-RAT wireless communication system100to provide valid V2X policy and parameters to the first UE180and the second UE190for configuring sidelink communication. In theFIG. 2example, the first UE180supports both LTE and NR technologies, and the second UE190supports NR technology.

At S205, the first UE180establishes a radio resource control (RRC) connection with the eNB131, and is connected into the EPS110.

At S210, the second UE190establishes an RRC connection with the gNB161and is connected into the 5GS140. It is noted that S205and S210may happen at the same time or in a different sequence.

At S220, the first UE180and the second UE190respectively execute a V2X application. In an example, the first UE180performs a suitable discovery process to find the second UE190that is nearby for sidelink communication. In another example, the second UE190performs a suitable discovery process to find the first UE180that is nearby for sidelink communication. It is noted that, in the present disclosure, the discovery process can be any suitable discovery process, such as an in-application discovery process, a discovery process independent of applications, and the like. In theFIG. 2example, NR technology is supported by both the first UE180and the second UE190, and the NR technology is determined for use in sidelink communication between the first UE180and the second UE190.

At S225, the first UE180checks whether valid V2X policy and parameters for NR technology is available at the first UE180. When the first UE180does not have valid V2X policy and parameters, the first UE180sends a request to the EPC network120. In an example, the MME122receives the request.

At S230, the second UE190checks whether valid V2X policy and parameters for the NR technology is available at the second UE190. When the second UE190does not have valid V2X policy and parameters, the second UE190sends a request to the 5GC network150. In an example, the AMF152receives the request.

At S240, the 5GC network150obtains valid V2X policy and parameters for the NR technology. In an example, the PCF151provides the valid V2X policy and parameters for the NR technology to the AMF152. It is noted that, in another example, the valid V2X policy and parameters for the NR technology can be provided from other suitable network function to the AMF152.

At S250, the EPC network120and the 5GC network150coordinates the cross RAT sidelink resource control. In an example, the MME122and the AMF152interact with suitable interfaces, such as via a PDN gateway, a UPF, and connections between the EPS110and the 5GS140. For example, the AMF152provides the valid V2X policy and parameters for the NR technology to the MME122.

At S255, the EPC network120provides the valid V2X policy and parameters for the NR technology to the first UE180. In an example, the MME122provides the valid V2X policy and parameters for the NR technology to the first UE180via eNB131. Then, the air interface between the eNB131and the first UE180carries, using the LTE technology, the valid V2X policy and parameters for the NR technology.

At S260, the 5GC network150provides the valid V2X policy and parameters for the NR technology to the second UE190. In an example, the AMF152provides the valid V2X policy and parameters for the NR technology to the second UE190via gNB161. Then, the air interface between the gNB161and the second UE190carries, using the NR technology, the valid V2X policy and parameters for the NR technology.

It is noted that S255and S260may be performed at the same time or in a different sequence. In some examples, S260may be performed before S250and after S240.

At S270, both the first UE180and the second UE190have valid V2X policy and parameters for NR technology, and thus can setup sidelink communication in the NR technology to transmit data in the user plane between the first UE180and the second UE190without go through the base stations.

FIG. 3shows an example for a coordination procedure300in the cross-RAT wireless communication system100according to an embodiment of the disclosure. The coordination procedure300enables the cross-RAT wireless communication system100to provide valid V2X policy and parameters to the first UE180and the second UE190for sidelink communication. In theFIG. 3example, the first UE180supports the LTE technology, and the second UE190supports both LTE and NR technologies.

At S305, the first UE180establishes a radio resource control (RRC) connection with the eNB131, and is connected into the EPS110.

At S310, the second UE190establishes an RRC connection with the gNB161and is connected into the 5GS140. It is noted that S305and S310may happen at the same time or in a different sequence.

At S320, the first UE180and the second UE190respectively execute a V2X application. In an example, the first UE180performs a suitable discovery process to find the second UE190that is nearby for sidelink communication. In another example, the second UE190performs a suitable discovery process to find the first UE180that is nearby for sidelink communication. It is noted that, in the present disclosure, the discovery process can be any suitable discovery process, such as an in-application discovery process, a discovery process independent of applications, and the like. In theFIG. 3example, the LTE technology is supported by both the first UE180and the second UE190, and the LTE technology is determined for use in sidelink communication between the first UE180and the second UE190.

At S325, the first UE180checks whether valid V2X policy and parameters for the LTE technology is available at the first UE180. When the first UE180does not have valid V2X policy and parameters, the first UE180sends a request to the EPC network120. In an example, the MME122receives the request.

At S330, the second UE190checks whether valid V2X policy and parameters for LTE technology is available at the second UE190. When the second UE190does not have valid V2X policy and parameters, the second UE190sends a request to the 5GC network150. In an example, the AMF152receives the request.

At S340, the EPC network120obtains valid V2X policy and parameters for the LTE technology. In an example, the V2X CF121provides the valid V2X policy and parameters for the LTE technology to the MME122.

At S350, the EPC network120and the 5GC network150coordinate the cross RAT sidelink resource control. In an example, the MME122and the AMF152interact with suitable interfaces, such as via a PDN gateway, a UPF, and connections between the EPS110and the 5GS140. In an example, the MME122provides the valid V2X policy and parameters for LTE technology to the AMF152.

At S355, the EPC network120provides the valid V2X policy and parameters for the LTE technology to the first UE180. In an example, the MME122provides the valid V2X policy and parameters for LTE technology to the first UE180via eNB131. Then, the air interface between the eNB131and the first UE180carries, using the LTE technology, the valid V2X policy and parameters for LTE technology.

At S360, the 5GC network150provides the valid V2X policy and parameters for the LTE technology to the second UE190. In an example, the AMF152provides the valid V2X policy and parameters for LTE technology to the second UE190via gNB161. Then, the air interface between the gNB161and the second UE190carries, using the NR technology, the valid V2X policy and parameters for LTE technology.

It is noted that S355and S360may be performed at the same time or in a different sequence. In another example, S355is performed before S350and after S340.

At S370, both the first UE180and the second UE190have valid V2X policy and parameters for the LTE technology, and thus can setup sidelink communication in the LTE technology to transmit data in the user plane between the first UE180and the second UE190without go through the base stations.

It is noted that, in another example, both the first UE180and the second UE190support both LTE and NR technology. During the discovery step, one of the first UE180and the second UE190may determine the technology for the sidelink communication. When the NR technology is determined for the sidelink communication, the coordination procedure is similar to the coordination procedure200; and when the LTE technology is determined for the sidelink communication, the coordination procedure is similar to the coordination procedure300.

FIG. 4shows an example for a coordination procedure400in the cross-RAT wireless communication system100according to an embodiment of the disclosure. The coordination procedure400enables the cross-RAT wireless communication system100to provide valid V2X policy and parameters to the first UE180and the second UE190for sidelink communication. In theFIG. 4example, the first UE180supports both LTE and NR technologies, and the second UE190supports NR technology.

At S405, the first UE180establishes a radio resource control (RRC) connection with the eNB131, and is connected into the EPS110.

At S410, the second UE190establishes an RRC connection with the gNB161and is connected into the 5GS140. It is noted that S505and S510may happen at the same time or in a different sequence.

At S420, the first UE180and the second UE190respectively execute a V2X application. For example, the first UE180and the second UE190are connected with the application server system170and executes functions provided by the AF171. In an example, the first UE180performs a suitable discovery process to find the second UE190that is nearby for sidelink communication. In another example, the second UE190performs a suitable discovery process to find the first UE180that is nearby for sidelink communication. It is noted that, in the present disclosure, the discovery process can be any suitable discovery process, such as an in-application discovery process, a discovery process independent of applications, and the like. In theFIG. 4example, NR technology is supported by both the first UE180and the second UE190, and the NR technology is determined for use in sidelink communication between the first UE180and the second UE190.

At S425, the first UE180checks whether valid V2X policy and parameters for NR technology is available at the first UE180. When the first UE180does not have valid V2X policy and parameters, the first UE180sends a request to the EPC network120. In an example, the MME122receives the request.

At S430, the second UE190checks whether valid V2X policy and parameters for NR technology is available at the second UE190. When the second UE190does not have valid V2X policy and parameters, the second UE190sends request to the 5GC network150. In an example, the AMF152receives the request.

At S440, the 5GC network150obtains valid V2X policy and parameters for the NR technology, and provides to the AF171in the application server system170. In an example, the PCF151provides the valid V2X policy and parameters for the NR technology to the AMF152. The AMF152interacts with suitable interfaces, such as via a PDN gateway, and connections between the 5GS140and the application server system170to provide the valid V2X policy and parameters for the NR technology to the AF171. In some embodiments, the EPC network120obtains valid V2X policy and parameters for the LTE technology, and provides to the AF171in the application server system170. In an example, the V2X CF121provides the valid V2X policy and parameters for the LTE technology to the MME122. The MME122interacts with suitable interfaces, such as via UPN, and connections between the EPS110and the application server system170to provide the valid V2X policy and parameters for the LTE technology to the AF171.

At S455, the application server system170provides the valid V2X policy and parameters for NR technology to the first UE180, for example in the application layer. In an example, a channel in the application layer is setup between the application server system170and the first UE180, and the valid V2X policy and parameters for NR technology is included in a message and provided via the channel from the AF171to the first UE180. It is noted that, in some examples, suitably encryption and authentication techniques are used on the message. It is noted that in some examples, the application server system170also provides the valid V2X policy and parameters for the LTE technology to the first UE180, for example in the application layer

At S460, the application server system170provides the valid V2X policy and parameters for the NR technology to the second UE190, for example in the application layer. In an example, a channel in the application layer is setup between the application server system170and the second UE190, and the valid V2X policy and parameters for NR technology is included in a message and provided via the channel from the AF171to the second UE190. It is noted that, in some examples, suitably encryption and authentication techniques are used on the message. It is noted that in some examples, the application server system170provides the valid V2X policy and parameters for the LTE technology to the second UE190, for example in the application layer.

It is noted that S455and S460may be performed at the same time or in a different order.

At S470, both the first UE180and the second UE190have valid V2X policy and parameters for NR technology, and thus can setup sidelink communication in the NR technology to transmit data in the user plane between the first UE180and the second UE190without go through the base stations.

FIG. 5shows an example for a coordination procedure500in the cross-RAT wireless communication system100according to an embodiment of the disclosure. The coordination procedure500enables the cross-RAT wireless communication system100to provide valid V2X policy and parameters to the first UE180and the second UE190for sidelink communication. In theFIG. 5example, the first UE180supports both LTE technology, and the second UE190supports both LTE and NR technologies.

At S505, the first UE180establishes a radio resource control (RRC) connection with the eNB131, and is connected into the EPS110.

At S510, the second UE190establishes an RRC connection with the gNB161and is connected into the 5GS140. It is noted that S505and S510may happen at the same time or in a different sequence.

At S520, the first UE180and the second UE190respectively execute a V2X application. In an example, the first UE180performs a suitable discovery process to find the second UE190that is nearby for sidelink communication. In another example, the second UE190performs a suitable discovery process to find the first UE180that is nearby for sidelink communication. It is noted that, in the present disclosure, the discovery process can be any suitable discovery process, such as an in-application discovery process, a discovery process independent of applications, and the like. In theFIG. 5example, the LTE technology is supported by both the first UE180and the second UE190, and the LTE technology is determined for use in sidelink communication between the first UE180and the second UE190.

At S525, the first UE180checks whether valid V2X policy and parameters for LTE technology is available at the first UE180. When the first UE180does not have valid V2X policy and parameters, the first UE180sends a request to the EPC network120. In an example, the MME122receives the request.

At S530, the second UE190checks whether valid V2X policy and parameters for LTE technology is available at the second UE190. When the second UE190does not have valid V2X policy and parameters, the second UE190sends a request to the 5GC network150. In an example, the AMF152receives the request.

At S540, the EPC network120obtains valid V2X policy and parameters for the LTE technology, and provides to the AF171in the application server system170. In an example, the V2X CF121provides the valid V2X policy and parameters for the LTE technology to the MME122. The MME122interacts with suitable interfaces, such as via UPN, and connections between the EPS110and the application server system170to provide the valid V2X policy and parameters for the LTE technology to the AF171. In some embodiments, the 5GC network150obtains valid V2X policy and parameters for the NR technology, and provides to the AF171in the application server system170. In an example, the PCF151provides the valid V2X policy and parameters for the NR technology to the AMF152. The AMF152interacts with suitable interfaces, such as via a PDN gateway, and connections between the 5GS140and the application server system170to provide the valid V2X policy and parameters for the NR technology to the AF171.

At S555, the application server system170provides the valid V2X policy and parameters for the LTE technology to the first UE180, for example in the application layer. In an example, a channel in the application layer is setup between the application server system170and the first UE180, and the valid V2X policy and parameters for the LTE technology is included in a message and provided via the channel from the AF171to the first UE180. It is noted that, in some examples, suitably encryption and authentication techniques are used on the message. It is noted that, in some examples, the application server system170provides the valid V2X policy and parameters for the NR technology to the first UE180, for example in the application layer.

At S560, the application server system170provides the valid V2X policy and parameters for the LTE technology to the second UE190, for example in the application layer. In an example, a channel in the application layer is setup between the application server system170and the second UE190, and the valid V2X policy and parameters for the LTE technology is included in a message and provided via the channel from the AF171to the second UE190. It is noted that, in some examples, suitably encryption and authentication techniques are used on the message. It is noted that, in some examples, the application server system170provides the valid V2X policy and parameters for the NR technology to the second UE190, for example in the application layer.

It is noted that S555and S560may be performed at the same time or in a different sequence.

At S570, both the first UE180and the second UE190have valid V2X policy and parameters for the LTE technology, and thus can setup sidelink communication in the LTE technology to transmit data in the user plane between the first UE180and the second UE190without go through the base stations.

It is noted that, in another example, both the first UE180and the second UE190support both LTE and NR technology. During the discovery step, one of the first UE180and the second UE190may determine the technology for the sidelink communication. When the NR technology is determined for the sidelink communication, the coordination procedure is similar to the coordination procedure400; and when the LTE technology is determined for the sidelink communication, the coordination procedure is similar to the coordination procedure500.

FIG. 6shows a flow chart outlining a process600according to an embodiment of the disclosure. The process600is executed by a first network, such as the EPS110, the 5GS140, and the like. In some examples, the process600is executed by circuitry, such processing circuitry, transceiver circuitry, and the like. In some examples, one or more processors execute software instructions stored in memory circuitry to execute the process600. The process starts at S601and proceeds to S610.

At S610, the first network receives a request from a first UE. The first network is based on a first RAT. The first UE is connected with the first network based on the first RAT. The request requests sidelink control information for a second RAT.

At S620, first network obtains the sidelink control information for the second RAT. In some examples, the first network coordinates with a second network that is based on the second RAT to receive the sidelink control information for the second RAT from the second network.

At S630, the first network provides, via the first RAT, the sidelink control information for the second RAT to the first UE. Thus, in some examples, the first UE can setup a sidelink in the second RAT with a second UE in the second network. Then, the process proceeds to S699and terminates.

FIG. 7shows a flow chart outlining a process700according to an embodiment of the disclosure. The process700is executed by an application function, such as the AF171in the application server system170, and the like. In some examples, the process700is executed by circuitry, such processing circuitry, transceiver circuitry, and the like. In some examples, one or more processors execute software instructions stored in memory circuitry to execute the process700. The process starts at S701and proceeds to S710.

At S710, the AF receives sidelink control information for a first RAT from a first network based on a first RAT and/or sidelink control information for a second RAT from a second network based on a second RAT. In an example, the EPC120receives a request from the UE180for sidelink control information for LTE. In response to the request, the EPC120provides the sidelink control information for LTE to the AF171. In an example, when the EPC120receives a request from the UE180for sidelink control information for NR, the EPC120does not have the sidelink control information for NR, and may forward the request to the AF171. It is noted that, the EPC120can forward the request for the sidelink control information of NR to the AF171, and provides the sidelink control information for LTE to the AF171. In an example, the 5GC150receives a request from the UE190for sidelink control information for NR. In response to the request, the 5GC150provides the sidelink control information for NR to the AF171. In an example, when the 5GC150receives a request from the UE190for sidelink control information for LTE, the 5GC150does not have the sidelink control information for LTE, and may forward the request to the AF171. It is noted that, the 5GC150can forward the request for the sidelink control information of LTE to the AF171, and provides the sidelink control information for NR to the AF171.

At S720, the AF coordinates with a first UE accessing the first NW and a second UE accessing the second UE using channels in the application layer. In an example, the application layer contains the communications protocols and interface methods used in process-to-process communications across, for, example, an Internet Protocol (IP) computer network. The application layer standardizes communication and depends upon the underlying transport layer protocols to establish host-to-host data transfer channels and manage the data exchange in a client-server or peer-to-peer networking model. For example, a first channel is setup between the AF171and the first UE180, messages are sent between the AF171and the first UE180by the first channel. The messages can be suitably encrypted, thus although the eNB131may transmit and receive signals carrying the messages, but is not able to decrypt messages in an example. Similarly, a second channel is setup between the AF171and the second UE190, messages are sent between the AF171and the second UE190by the second channel.

At S730, the AF provides at least one of the sidelink control information for the first RAT and the sidelink control information for the second RAT to the first UE and the second UE using the channels in the application layer. In an example, the AF171provides the sidelink control information for LTE to the first UE180via the first channel and provides the sidelink control information for the LTE to the second UE190via the second channel. Thus, the first UE180and the second UE190can setup LTE sidelink. In another example, the AF171provides the sidelink control information for NR to the first UE180via the first channel and provides the sidelink control information for the NR to the second UE190via the second channel. Thus, the first UE180and the second UE190can setup NR sidelink. In another example, the AF171provides the sidelink control information for LTE and NR to the first UE180via the first channel and provides the sidelink control information for the LTE and NR to the second UE190via the second channel. Thus, the first UE180and the second UE190can setup LTE or NR sidelink. Then, the process proceeds to S799and terminates.

FIG. 8shows a flow chart outlining a process800according to an embodiment of the disclosure. The process800is executed by an UE, such as the first UE180, the second UE190and the like. In some examples, the process800is executed by circuitry in the UE, such processing circuitry, transceiver circuitry, and the like. In some examples, one or more processors in the UE execute software instructions stored in memory circuitry to execute the process800. The process starts at S801and proceeds to S810.

At S810, a first UE establishes an RRC with a first NW based on a first RAT. In an example, the first UE180in theFIG. 1example establishes an RRC with the E-UTRAN130based on LTE, and is then connected into the EPS110. The second UE190in theFIG. 1example establishes an RRC with NG-RAN160, and is then connected into the 5GS140.

At S820, the first UE sends a request to the first NW requesting sidelink control information for a second RAT. In an example, the first UE180and the second UE190conduct a discovery process, and decides to setup NR sidelink between the first UE180and the second UE190. The first UE180checks whether the first UE180has valid sidelink control information for NR, and sends a request for valide sidelink control information for NR to the EPC120.

At S830, the first UE receives the sidelink control information for the second RAT. In an example, the EPC120and the 5GC150coordinate, and the 5GC150provides the valid sidelink control information (e.g., sidelink policy and parameters) for NR to the EPC120, and the EPC120provides the valid sidelink control information for NR to the first UE180. In another example, the 5GC150provides the valid sidelink control information for NR to the AF171, and then the AF171then sends the valid sidelink control information for NR to the first UE180via a channel in the application layer. The AF171may also sends the valid sidelink control information for NR to the second UE190via a channel in the application layer.

At S840, the first UE and the second UE set up a sidelink of the second RAT based on the sidelink control information for the second RAT, and transmit user data in the sidelink. Then, the process proceeds to S899and terminates.

FIG. 9shows a block diagram of a UE900according to embodiments of the disclosure. In an example, the first UE180and the second UE190can be respectively configured in the same manner as the UE900. The UE900can be configured to perform various functions in accordance with one or more embodiments or examples described herein. Thus, the UE900can provide means for implementation of techniques, processes, functions, components, systems described herein. For example, the UE900can be used to implement functions of the first UE180or the second UE190in various embodiments and examples described herein. The UE900can be a general purpose computer in some embodiments, and can be a device including specially designed circuits to implement various functions, components, or processes described herein in other embodiments. The UE900can include processing circuitry910, a memory920, a radio frequency (RF) module930, and an antenna940.

In various examples, the processing circuitry910can include circuitry configured to perform the functions and processes described herein in combination with software or without software. In various examples, the processing circuitry can be a digital signal processor (DSP), an application specific integrated circuit (ASIC), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), digitally enhanced circuits, or comparable device or a combination thereof.

In some other examples, the processing circuitry910can be a central processing unit (CPU) configured to execute program instructions to perform various functions and processes described herein. Accordingly, the memory920can be configured to store program instructions. The processing circuitry910, when executing the program instructions, can perform the functions and processes. The memory920can further store other programs or data, such as operating systems, application programs, and the like. The memory can include transitory or non-transitory storage medium. The memory920can include a read only memory (ROM), a random access memory (RAM), a flash memory, a solid state memory, a hard disk drive, an optical disk drive, and the like.

The RF module930receives processed data signal from the processing circuitry910and transmits the signal in a beam-formed wireless communication network via an antenna940, or vice versa. The RF module930can include a digital to analog convertor (DAC), an analog to digital converter (ADC), a frequency up convertor, a frequency down converter, filters, and amplifiers for reception and transmission operations. The RF module930can include multi-antenna circuitry (e.g., analog signal phase/amplitude control units) for beamforming operations. The antenna940can include one or more antenna arrays.

The UE900can optionally include other components, such as input and output devices, additional or signal processing circuitry, and the like. Accordingly, the UE900may be capable of performing other additional functions, such as executing application programs, and processing alternative communication protocols.

The processes and functions described herein can be implemented as a computer program which, when executed by one or more processors, can cause the one or more processors to perform the respective processes and functions. The computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with, or as part of, other hardware. The computer program may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. For example, the computer program can be obtained and loaded into an apparatus, including obtaining the computer program through physical medium or distributed system, including, for example, from a server connected to the Internet.

The computer program may be accessible from a computer-readable medium providing program instructions for use by or in connection with a computer or any instruction execution system. The computer readable medium may include any apparatus that stores, communicates, propagates, or transports the computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable medium can be magnetic, optical, electronic, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. The computer-readable medium may include a computer-readable non-transitory storage medium such as a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a magnetic disk and an optical disk, and the like. The computer-readable non-transitory storage medium can include all types of computer readable medium, including magnetic storage medium, optical storage medium, flash medium, and solid state storage medium.

When implemented in hardware, the hardware may comprise one or more of discrete components, an integrated circuit, an application-specific integrated circuit (ASIC), etc. While aspects of the present disclosure have been described in conjunction with the specific embodiments thereof that are proposed as examples, alternatives, modifications, and variations to the examples may be made. Accordingly, embodiments as set forth herein are intended to be illustrative and not limiting. There are changes that may be made without departing from the scope of the claims set forth below.