Patent Description:
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 (<NUM>), is new radio access technology (RAT) beyond Long Term Evolution (LTE) which is also referred to as fourth generation (<NUM>). NR may coexist with LTE during network deployments of the new generation.

<CIT> discloses a method implemented at a first user equipment which supports a first radio access technology, the method comprises: determining a sidelink transmission mode for transmitting, wherein the sidelink transmission mode is one of a first mode corresponding to the first radio access technology and a second mode corresponding to a second radio access technology; and transmitting a sidelink signal according to the sidelink transmission mode using a sidelink resource configured by a network node which serves the first user equipment.

<CIT> discloses a method for performing a sidelink communication through a terminal-to-network relay operation. The method for performing the sidelink communication performed by a first terminal may comprise a step of transmitting a control message including indication information indicating whether a radio access technology (RAT) type of a radio interface section with a second terminal is a 3GPP access or a non-3GPP access to a base station; a step of receiving a radio resource for transmitting and receiving signals with the second terminal through the radio interface section from the base station; and a step of transmitting and receiving the signal to and from the second terminal on the basis of the received radio resource.

<NPL>, discloses how to perform Radio Access Technology, RAT, selection for sidelink, SL. More specifically, proposal <NUM> and question <NUM> discuss options which layer should be responsible for RAT selection: Upper layer, AS layer, both upper layer and AS layer.

<NPL>, discloses Radio Access Technology, RAT, selection for V2X transmission.

Aspects of the disclosure provide methods for an application function server system to control sidelink resource in accordance with claim <NUM>. 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.

Various embodiments of this disclosure that are proposed as examples will be described in detail with reference to the following figures, wherein like numerals reference like elements, and wherein:.

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 <NUM> 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 <NUM> core (5GC) network and <NUM> 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> shows a diagram of a cross-RAT wireless communication system <NUM> according to some embodiments of the disclosure. The cross-RAT wireless communication system <NUM> includes 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 the <FIG> example, the cross-RAT wireless communication system <NUM> includes a first sub-system <NUM> and a second sub-system <NUM>. In some examples, the first sub-system <NUM> is an EPS <NUM> that is configured based on LTE technology, and the second sub-system <NUM> is a 5GS <NUM> that is configured based on the NR technology. For example, the EPS <NUM> includes an evolved packet core (EPC) network <NUM> and an evolved universal terrestrial radio access network (E-UTRAN) <NUM> for air interface, and the 5GS <NUM> includes a <NUM> core 5GC) network <NUM> and a next generation (NG) radio access network (NG-RAN) <NUM> for air interface. It is noted that the cross-RAT wireless communication system <NUM> can include other suitable sub-systems, such as an application server system <NUM> and the like. The sub-systems <NUM>, <NUM> and <NUM> are suitably connected, for example by Internet, and the like to enable control signals and/or data communication among the sub-systems.

The E-UTRAN <NUM> includes 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-UTRAN <NUM> are 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-RAN <NUM> includes 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-RAN <NUM> are 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) <NUM> and a second UE <NUM> are respectively connected into the EPS <NUM> and the 5GS <NUM>. For example, the first UE <NUM> is connected with the EPC <NUM> via the E-UTRAN <NUM>, and the second UE <NUM> is connected with the 5GC <NUM> via the NG-RAN <NUM>. In the <FIG> example, the first UE <NUM> is connected into the EPS <NUM> via an eNB <NUM>, and the second UE <NUM> is connected into the 5GS <NUM> via a gNB <NUM>.

Further, according to some aspects of the disclosure, the first UE <NUM> and the second UE <NUM> may perform data communication directly via a sidelink without going through a base station. In an example, both the first UE <NUM> and the second UE <NUM> support LTE technology and NR technology, and may communicate directly over a LTE sidelink or an NR sidelink based on coordination of the EPS <NUM> and 5GS <NUM> in the cross-RAT wireless communication system <NUM>. In another example, the first UE <NUM> supports LTE technology, and the second UE <NUM> supports both LTE and NR technology, and the first UE <NUM> and the second UE <NUM> may communicate directly over a LTE sidelink based on coordination of the EPS <NUM> and 5GS <NUM> in the cross-RAT wireless communication system <NUM>. In another example, the first UE <NUM> supports both LTE technology and NR technology, and the second UE <NUM> supports the NR technology, and the first UE <NUM> and the second UE <NUM> may communicate directly over an NR sidelink based on coordination of the EPS <NUM> and 5GS <NUM> in the cross-RAT wireless communication system <NUM>. In some embodiments, the coordination of t the EPS <NUM> and 5GS <NUM> may go through a third party, such as the application server system <NUM> and the like.

It is noted that, in the <FIG> example, 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 UE <NUM> and the second UE <NUM> can 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 vehicle <NUM> and a second vehicle <NUM> as an example of the first UE <NUM> and the second UE <NUM>, and the description can be modified to suit for other devices.

The EPC network <NUM> includes various network elements. In some examples, the EPC network <NUM> includes a mobility management entity (MME) <NUM>, 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) <NUM>, and the like.

It is noted that, in an example, each network element in the EPC network <NUM> can 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 EPS <NUM>. The serving gateways are the points of interconnection between the E-UTRAN <NUM> and the EPC network <NUM>. 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 network <NUM> and the external IP networks. The PDN gateways route packets to and from the packet data networks for example.

In some examples, the MME <NUM> is configured to handle with the control plane. For example, the MME <NUM> handles the signaling related to mobility and security for accessing E-UTRAN <NUM>.

It is noted that, in some examples, the MME <NUM> and the serving gateways are combined into a network element for performing both functions.

The V2X-CF <NUM> is 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 network <NUM> includes various service functions for providing services. In some examples, the 5GC network <NUM> includes a core access and mobility management function (AMF) <NUM>, policy control function (PCF) <NUM>, 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 network <NUM>. In another example, an AF is implemented in the domain of a third party, such as in the application server system <NUM>, in user equipment, and the like. <FIG> shows that the application server system <NUM> includes an AF <NUM>.

It is noted that, in an example, each function in the 5GC network <NUM> can 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 AMF <NUM> receives 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 PCF <NUM> provides policy rules for control plane functions, such as network slicing, roaming and mobility management. Further, the PCF <NUM> can access subscription information for policy decisions, and supports the quality of service (QoS) policy and charging control functions. In an example, the PCF <NUM> can 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 network <NUM>.

In some embodiments, user equipments use valide V2X policy and parameters provisioned by core networks for sidelink communication. For example, the V2X CF <NUM> can provide V2X policy and parameters for configuring LTE sidelinks for V2X communication; and the PCF <NUM> can provide V2X policy and parameters for configuring NR sidelinks for V2X communication.

According to an aspect of the disclosure, the EPC network <NUM> and the 5GC network <NUM> coordinate to provide suitable V2X policy and parameters to enable cross RAT radio resource control on the sidelink communication between the first UE <NUM> and the second UE <NUM>. Some coordination procedures for cross-RAT sidelink control are shown in <FIG> and <FIG>.

According to another aspect of the disclosure, the coordination of the EPC network <NUM> and the 5GC network <NUM> for providing suitable V2X policy and parameters go through the AF <NUM>. In an example, the application server system <NUM> is a vehicle application server system <NUM> that provides V2X communication service. Some coordination procedures for cross-RAT sidelink control are shown in <FIG> and <FIG>. It is noted that the application server system <NUM> can 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> shows an example of a coordination procedure <NUM> in the cross-RAT wireless communication system <NUM> according to an embodiment of the disclosure. The coordination procedure <NUM> enables the cross-RAT wireless communication system <NUM> to provide valid V2X policy and parameters to the first UE <NUM> and the second UE <NUM> for configuring sidelink communication. In the <FIG> example, the first UE <NUM> supports both LTE and NR technologies, and the second UE <NUM> supports NR technology.

At S205, the first UE <NUM> establishes a radio resource control (RRC) connection with the eNB <NUM>, and is connected into the EPS <NUM>.

At S210, the second UE <NUM> establishes an RRC connection with the gNB <NUM> and is connected into the 5GS <NUM>. It is noted that S205 and S210 may happen at the same time or in a different sequence.

At S220, the first UE <NUM> and the second UE <NUM> respectively execute a V2X application. In an example, the first UE <NUM> performs a suitable discovery process to find the second UE <NUM> that is nearby for sidelink communication. In another example, the second UE <NUM> performs a suitable discovery process to find the first UE <NUM> that 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 the <FIG> example, NR technology is supported by both the first UE <NUM> and the second UE <NUM>, and the NR technology is determined for use in sidelink communication between the first UE <NUM> and the second UE <NUM>.

At S225, the first UE <NUM> checks whether valid V2X policy and parameters for NR technology is available at the first UE <NUM>. When the first UE <NUM> does not have valid V2X policy and parameters, the first UE <NUM> sends a request to the EPC network <NUM>. In an example, the MME <NUM> receives the request.

At S230, the second UE <NUM> checks whether valid V2X policy and parameters for the NR technology is available at the second UE <NUM>. When the second UE <NUM> does not have valid V2X policy and parameters, the second UE <NUM> sends a request to the 5GC network <NUM>. In an example, the AMF <NUM> receives the request.

At S240, the 5GC network <NUM> obtains valid V2X policy and parameters for the NR technology. In an example, the PCF <NUM> provides the valid V2X policy and parameters for the NR technology to the AMF <NUM>. 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 AMF <NUM>.

At S250, the EPC network <NUM> and the 5GC network <NUM> coordinates the cross RAT sidelink resource control. In an example, the MME <NUM> and the AMF <NUM> interact with suitable interfaces, such as via a PDN gateway, a UPF, and connections between the EPS <NUM> and the 5GS <NUM>. For example, the AMF <NUM> provides the valid V2X policy and parameters for the NR technology to the MME <NUM>.

At S255, the EPC network <NUM> provides the valid V2X policy and parameters for the NR technology to the first UE <NUM>. In an example, the MME <NUM> provides the valid V2X policy and parameters for the NR technology to the first UE <NUM> via eNB <NUM>. Then, the air interface between the eNB <NUM> and the first UE <NUM> carries, using the LTE technology, the valid V2X policy and parameters for the NR technology.

At S260, the 5GC network <NUM> provides the valid V2X policy and parameters for the NR technology to the second UE <NUM>. In an example, the AMF <NUM> provides the valid V2X policy and parameters for the NR technology to the second UE <NUM> via gNB <NUM>. Then, the air interface between the gNB <NUM> and the second UE <NUM> carries, using the NR technology, the valid V2X policy and parameters for the NR technology.

It is noted that S255 and S260 may be performed at the same time or in a different sequence. In some examples, S260 may be performed before S250 and after S240.

At S270, both the first UE <NUM> and the second UE <NUM> have 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 UE <NUM> and the second UE <NUM> without go through the base stations.

<FIG> shows an example for a coordination procedure <NUM> in the cross-RAT wireless communication system <NUM> according to an embodiment of the disclosure. The coordination procedure <NUM> enables the cross-RAT wireless communication system <NUM> to provide valid V2X policy and parameters to the first UE <NUM> and the second UE <NUM> for sidelink communication. In the <FIG> example, the first UE <NUM> supports the LTE technology, and the second UE <NUM> supports both LTE and NR technologies.

At S305, the first UE <NUM> establishes a radio resource control (RRC) connection with the eNB <NUM>, and is connected into the EPS <NUM>.

At S310, the second UE <NUM> establishes an RRC connection with the gNB <NUM> and is connected into the 5GS <NUM>. It is noted that S305 and S310 may happen at the same time or in a different sequence.

At S320, the first UE <NUM> and the second UE <NUM> respectively execute a V2X application. In an example, the first UE <NUM> performs a suitable discovery process to find the second UE <NUM> that is nearby for sidelink communication. In another example, the second UE <NUM> performs a suitable discovery process to find the first UE <NUM> that 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 the <FIG> example, the LTE technology is supported by both the first UE <NUM> and the second UE <NUM>, and the LTE technology is determined for use in sidelink communication between the first UE <NUM> and the second UE <NUM>.

At S325, the first UE <NUM> checks whether valid V2X policy and parameters for the LTE technology is available at the first UE <NUM>. When the first UE <NUM> does not have valid V2X policy and parameters, the first UE <NUM> sends a request to the EPC network <NUM>. In an example, the MME <NUM> receives the request.

At S330, the second UE <NUM> checks whether valid V2X policy and parameters for LTE technology is available at the second UE <NUM>. When the second UE <NUM> does not have valid V2X policy and parameters, the second UE <NUM> sends a request to the 5GC network <NUM>. In an example, the AMF <NUM> receives the request.

At S340, the EPC network <NUM> obtains valid V2X policy and parameters for the LTE technology. In an example, the V2X CF <NUM> provides the valid V2X policy and parameters for the LTE technology to the MME <NUM>.

At S350, the EPC network <NUM> and the 5GC network <NUM> coordinate the cross RAT sidelink resource control. In an example, the MME <NUM> and the AMF <NUM> interact with suitable interfaces, such as via a PDN gateway, a UPF, and connections between the EPS <NUM> and the 5GS <NUM>. In an example, the MME <NUM> provides the valid V2X policy and parameters for LTE technology to the AMF <NUM>.

At S355, the EPC network <NUM> provides the valid V2X policy and parameters for the LTE technology to the first UE <NUM>. In an example, the MME <NUM> provides the valid V2X policy and parameters for LTE technology to the first UE <NUM> via eNB <NUM>. Then, the air interface between the eNB <NUM> and the first UE <NUM> carries, using the LTE technology, the valid V2X policy and parameters for LTE technology.

At S360, the 5GC network <NUM> provides the valid V2X policy and parameters for the LTE technology to the second UE <NUM>. In an example, the AMF <NUM> provides the valid V2X policy and parameters for LTE technology to the second UE <NUM> via gNB <NUM>. Then, the air interface between the gNB <NUM> and the second UE <NUM> carries, using the NR technology, the valid V2X policy and parameters for LTE technology.

It is noted that S355 and S360 may be performed at the same time or in a different sequence. In another example, S355 is performed before S350 and after S340.

At S370, both the first UE <NUM> and the second UE <NUM> have 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 UE <NUM> and the second UE <NUM> without go through the base stations.

It is noted that, in another example, both the first UE <NUM> and the second UE <NUM> support both LTE and NR technology. During the discovery step, one of the first UE <NUM> and the second UE <NUM> may 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 procedure <NUM>; and when the LTE technology is determined for the sidelink communication, the coordination procedure is similar to the coordination procedure <NUM>.

<FIG> shows an example for a coordination procedure <NUM> in the cross-RAT wireless communication system <NUM> according to an embodiment of the disclosure. The coordination procedure <NUM> enables the cross-RAT wireless communication system <NUM> to provide valid V2X policy and parameters to the first UE <NUM> and the second UE <NUM> for sidelink communication. In the <FIG> example, the first UE <NUM> supports both LTE and NR technologies, and the second UE <NUM> supports NR technology.

At S405, the first UE <NUM> establishes a radio resource control (RRC) connection with the eNB <NUM>, and is connected into the EPS <NUM>.

At S410, the second UE <NUM> establishes an RRC connection with the gNB <NUM> and is connected into the 5GS <NUM>. It is noted that S505 and S510 may happen at the same time or in a different sequence.

At S420, the first UE <NUM> and the second UE <NUM> respectively execute a V2X application. For example, the first UE <NUM> and the second UE <NUM> are connected with the application server system <NUM> and executes functions provided by the AF <NUM>. In an example, the first UE <NUM> performs a suitable discovery process to find the second UE <NUM> that is nearby for sidelink communication. In another example, the second UE <NUM> performs a suitable discovery process to find the first UE <NUM> that 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 the <FIG> example, NR technology is supported by both the first UE <NUM> and the second UE <NUM>, and the NR technology is determined for use in sidelink communication between the first UE <NUM> and the second UE <NUM>.

At S425, the first UE <NUM> checks whether valid V2X policy and parameters for NR technology is available at the first UE <NUM>. When the first UE <NUM> does not have valid V2X policy and parameters, the first UE <NUM> sends a request to the EPC network <NUM>. In an example, the MME <NUM> receives the request.

At S430, the second UE <NUM> checks whether valid V2X policy and parameters for NR technology is available at the second UE <NUM>. When the second UE <NUM> does not have valid V2X policy and parameters, the second UE <NUM> sends request to the 5GC network <NUM>. In an example, the AMF <NUM> receives the request.

At S440, the 5GC network <NUM> obtains valid V2X policy and parameters for the NR technology, and provides to the AF <NUM> in the application server system <NUM>. In an example, the PCF <NUM> provides the valid V2X policy and parameters for the NR technology to the AMF <NUM>. The AMF <NUM> interacts with suitable interfaces, such as via a PDN gateway, and connections between the 5GS <NUM> and the application server system <NUM> to provide the valid V2X policy and parameters for the NR technology to the AF <NUM>. In some embodiments, the EPC network <NUM> obtains valid V2X policy and parameters for the LTE technology, and provides to the AF <NUM> in the application server system <NUM>. In an example, the V2X CF <NUM> provides the valid V2X policy and parameters for the LTE technology to the MME <NUM>. The MME <NUM> interacts with suitable interfaces, such as via UPN, and connections between the EPS <NUM> and the application server system <NUM> to provide the valid V2X policy and parameters for the LTE technology to the AF <NUM>.

At S455, the application server system <NUM> provides the valid V2X policy and parameters for NR technology to the first UE <NUM>, for example in the application layer. In an example, a channel in the application layer is setup between the application server system <NUM> and the first UE <NUM>, and the valid V2X policy and parameters for NR technology is included in a message and provided via the channel from the AF <NUM> to the first UE <NUM>. 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 system <NUM> also provides the valid V2X policy and parameters for the LTE technology to the first UE <NUM>, for example in the application layer.

At S460, the application server system <NUM> provides the valid V2X policy and parameters for the NR technology to the second UE <NUM>, for example in the application layer. In an example, a channel in the application layer is setup between the application server system <NUM> and the second UE <NUM>, and the valid V2X policy and parameters for NR technology is included in a message and provided via the channel from the AF <NUM> to the second UE <NUM>. 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 system <NUM> provides the valid V2X policy and parameters for the LTE technology to the second UE <NUM>, for example in the application layer.

It is noted that S455 and S460 may be performed at the same time or in a different order.

At S470, both the first UE <NUM> and the second UE <NUM> have 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 UE <NUM> and the second UE <NUM> without go through the base stations.

<FIG> shows an example for a coordination procedure <NUM> in the cross-RAT wireless communication system <NUM> according to an embodiment of the disclosure. The coordination procedure <NUM> enables the cross-RAT wireless communication system <NUM> to provide valid V2X policy and parameters to the first UE <NUM> and the second UE <NUM> for sidelink communication. In the <FIG> example, the first UE <NUM> supports both LTE technology, and the second UE <NUM> supports both LTE and NR technologies.

At S505, the first UE <NUM> establishes a radio resource control (RRC) connection with the eNB <NUM>, and is connected into the EPS <NUM>.

At S510, the second UE <NUM> establishes an RRC connection with the gNB <NUM> and is connected into the 5GS <NUM>. It is noted that S505 and S510 may happen at the same time or in a different sequence.

At S520, the first UE <NUM> and the second UE <NUM> respectively execute a V2X application. In an example, the first UE <NUM> performs a suitable discovery process to find the second UE <NUM> that is nearby for sidelink communication. In another example, the second UE <NUM> performs a suitable discovery process to find the first UE <NUM> that 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 the <FIG> example, the LTE technology is supported by both the first UE <NUM> and the second UE <NUM>, and the LTE technology is determined for use in sidelink communication between the first UE <NUM> and the second UE <NUM>.

At S525, the first UE <NUM> checks whether valid V2X policy and parameters for LTE technology is available at the first UE <NUM>. When the first UE <NUM> does not have valid V2X policy and parameters, the first UE <NUM> sends a request to the EPC network <NUM>. In an example, the MME <NUM> receives the request.

At S530, the second UE <NUM> checks whether valid V2X policy and parameters for LTE technology is available at the second UE <NUM>. When the second UE <NUM> does not have valid V2X policy and parameters, the second UE <NUM> sends a request to the 5GC network <NUM>. In an example, the AMF <NUM> receives the request.

At S540, the EPC network <NUM> obtains valid V2X policy and parameters for the LTE technology, and provides to the AF <NUM> in the application server system <NUM>. In an example, the V2X CF <NUM> provides the valid V2X policy and parameters for the LTE technology to the MME <NUM>. The MME <NUM> interacts with suitable interfaces, such as via UPN, and connections between the EPS <NUM> and the application server system <NUM> to provide the valid V2X policy and parameters for the LTE technology to the AF <NUM>. In some embodiments, the 5GC network <NUM> obtains valid V2X policy and parameters for the NR technology, and provides to the AF <NUM> in the application server system <NUM>. In an example, the PCF <NUM> provides the valid V2X policy and parameters for the NR technology to the AMF <NUM>. The AMF <NUM> interacts with suitable interfaces, such as via a PDN gateway, and connections between the 5GS <NUM> and the application server system <NUM> to provide the valid V2X policy and parameters for the NR technology to the AF <NUM>.

At S555, the application server system <NUM> provides the valid V2X policy and parameters for the LTE technology to the first UE <NUM>, for example in the application layer. In an example, a channel in the application layer is setup between the application server system <NUM> and the first UE <NUM>, and the valid V2X policy and parameters for the LTE technology is included in a message and provided via the channel from the AF <NUM> to the first UE <NUM>. 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 system <NUM> provides the valid V2X policy and parameters for the NR technology to the first UE <NUM>, for example in the application layer.

At S560, the application server system <NUM> provides the valid V2X policy and parameters for the LTE technology to the second UE <NUM>, for example in the application layer. In an example, a channel in the application layer is setup between the application server system <NUM> and the second UE <NUM>, and the valid V2X policy and parameters for the LTE technology is included in a message and provided via the channel from the AF <NUM> to the second UE <NUM>. 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 system <NUM> provides the valid V2X policy and parameters for the NR technology to the second UE <NUM>, for example in the application layer.

It is noted that S555 and S560 may be performed at the same time or in a different sequence.

At S570, both the first UE <NUM> and the second UE <NUM> have 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 UE <NUM> and the second UE <NUM> without go through the base stations.

<FIG> shows a flow chart outlining a process <NUM> according to an embodiment of the disclosure. The process <NUM> is executed by a first network, such as the EPS <NUM>, the 5GS <NUM>, and the like. In some examples, the process <NUM> is 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 process <NUM>. The process starts at S601 and 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 S699 and terminates.

<FIG> shows a flow chart outlining a process <NUM> according to an embodiment of the disclosure. The process <NUM> is executed by an application function, such as the AF <NUM> in the application server system <NUM>, and the like. In some examples, the process <NUM> is 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 process <NUM>. The process starts at S701 and 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 EPC <NUM> receives a request from the UE <NUM> for sidelink control information for LTE. In response to the request, the EPC <NUM> provides the sidelink control information for LTE to the AF <NUM>. In an example, when the EPC <NUM> receives a request from the UE <NUM> for sidelink control information for NR, the EPC <NUM> does not have the sidelink control information for NR, and may forward the request to the AF <NUM>. It is noted that, the EPC <NUM> can forward the request for the sidelink control information of NR to the AF <NUM>, and provides the sidelink control information for LTE to the AF <NUM>. In an example, the 5GC <NUM> receives a request from the UE <NUM> for sidelink control information for NR. In response to the request, the 5GC <NUM> provides the sidelink control information for NR to the AF <NUM>. In an example, when the 5GC <NUM> receives a request from the UE <NUM> for sidelink control information for LTE, the 5GC <NUM> does not have the sidelink control information for LTE, and may forward the request to the AF <NUM>. It is noted that, the 5GC <NUM> can forward the request for the sidelink control information of LTE to the AF <NUM>, and provides the sidelink control information for NR to the AF <NUM>.

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 AF <NUM> and the first UE <NUM>, messages are sent between the AF <NUM> and the first UE <NUM> by the first channel. The messages can be suitably encrypted, thus although the eNB <NUM> may 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 AF <NUM> and the second UE <NUM>, messages are sent between the AF <NUM> and the second UE <NUM> by 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 AF <NUM> provides the sidelink control information for LTE to the first UE <NUM> via the first channel and provides the sidelink control information for the LTE to the second UE <NUM> via the second channel. Thus, the first UE <NUM> and the second UE <NUM> can setup LTE sidelink. In another example, the AF <NUM> provides the sidelink control information for NR to the first UE <NUM> via the first channel and provides the sidelink control information for the NR to the second UE <NUM> via the second channel. Thus, the first UE <NUM> and the second UE <NUM> can setup NR sidelink. In another example, the AF <NUM> provides the sidelink control information for LTE and NR to the first UE <NUM> via the first channel and provides the sidelink control information for the LTE and NR to the second UE <NUM> via the second channel. Thus, the first UE <NUM> and the second UE <NUM> can setup LTE or NR sidelink. Then, the process proceeds to S799 and terminates.

<FIG> shows a flow chart outlining a process <NUM> according to an embodiment of the disclosure. The process <NUM> is executed by an UE, such as the first UE <NUM>, the second UE <NUM> and the like. In some examples, the process <NUM> is 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 process <NUM>. The process starts at S801 and 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 UE <NUM> in the <FIG> example establishes an RRC with the E-UTRAN <NUM> based on LTE, and is then connected into the EPS <NUM>. The second UE <NUM> in the <FIG> example establishes an RRC with NG-RAN <NUM>, and is then connected into the 5GS <NUM>.

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 UE <NUM> and the second UE <NUM> conduct a discovery process, and decides to setup NR sidelink between the first UE <NUM> and the second UE <NUM>. The first UE <NUM> checks whether the first UE <NUM> has valid sidelink control information for NR, and sends a request for valide sidelink control information for NR to the EPC <NUM>.

At S830, the first UE receives the sidelink control information for the second RAT. In an example, the EPC <NUM> and the 5GC <NUM> coordinate, and the 5GC <NUM> provides the valid sidelink control information (e.g., sidelink policy and parameters) for NR to the EPC <NUM>, and the EPC <NUM> provides the valid sidelink control information for NR to the first UE <NUM>. In another example, the 5GC <NUM> provides the valid sidelink control information for NR to the AF <NUM>, and then the AF <NUM> then sends the valid sidelink control information for NR to the first UE <NUM> via a channel in the application layer. The AF <NUM> may also sends the valid sidelink control information for NR to the second UE <NUM> via 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 S899 and terminates.

<FIG> shows a block diagram of a UE <NUM> according to embodiments of the disclosure. In an example, the first UE <NUM> and the second UE <NUM> can be respectively configured in the same manner as the UE <NUM>. The UE <NUM> can be configured to perform various functions in accordance with one or more embodiments or examples described herein. Thus, the UE <NUM> can provide means for implementation of techniques, processes, functions, components, systems described herein. For example, the UE <NUM> can be used to implement functions of the first UE <NUM> or the second UE <NUM> in various embodiments and examples described herein. The UE <NUM> can 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 UE <NUM> can include processing circuitry <NUM>, a memory <NUM>, a radio frequency (RF) module <NUM>, and an antenna <NUM>.

In various examples, the processing circuitry <NUM> can 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 circuitry <NUM> can be a central processing unit (CPU) configured to execute program instructions to perform various functions and processes described herein. Accordingly, the memory <NUM> can be configured to store program instructions. The processing circuitry <NUM>, when executing the program instructions, can perform the functions and processes. The memory <NUM> can 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 memory <NUM> can 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 module <NUM> receives processed data signal from the processing circuitry <NUM> and transmits the signal in a beam-formed wireless communication network via an antenna <NUM>, or vice versa. The RF module <NUM> can 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 module <NUM> can include multi-antenna circuitry (e.g., analog signal phase/amplitude control units) for beamforming operations. The antenna <NUM> can include one or more antenna arrays.

The UE <NUM> can optionally include other components, such as input and output devices, additional or signal processing circuitry, and the like. Accordingly, the UE <NUM> may 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.

Claim 1:
A method for sidelink resource control, comprising:
receiving by a first network (<NUM>) a request for sidelink control information for a first radio access technology from a first user equipment (<NUM>) that accesses the first network using the first radio access technology;
in response to the request, providing by the first network the sidelink control information for the first radio access technology to an application function, AF, server system,
receiving, by the application function, AF, server system (<NUM>), the sidelink control information for the first radio access technology from the first network configured based on the first radio access technology;
coordinating with the first user equipment that accesses the first network using the first radio access technology, and a second user equipment (<NUM>) that accesses a second network (<NUM>) using a second radio access technology, via channels in an application layer; and
providing 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.