Patent Description:
A platoon is a group of automated vehicles that are equipped with various antenna and sensors to communicate with each other or a base station (BS). Within a platoon, vehicles may exchange information such as position and kinematic status in order to enable context-aware cooperation. This would improve vehicle safety as well as efficiency of the road use because it allows vehicles to be aware of the location and direction of other vehicles in the vicinity. Platoon members (e.g., vehicles) within a same platoon may communicate with each other over PC5 interface, which is handled by an access stratum (AS) layer. The AS layer may need to be configured with a specific range based on platoon specific events and/or characteristics (e.g., a number of platoon members, type of devices, etc.). Thus, in order for the platoon members to join and/or leave the platoon at any moment, methods and apparatuses that dynamically adapt the configuration of PC5 communication are needed.

Patent document <CIT> discloses dynamically adapting the transmission range of group members based on the determination of group density or size. However, it is presented in the context of adhoc networks without external servers.

Further detailed embodiments are defined in the dependent claims.

By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and/or a "STA", may be configured to transmit and/or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a train, an airplane, a helicopter, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like.

The full duplex radio may include an interference management unit <NUM> to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor <NUM>). In an embodiment, the WTRU <NUM> may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

The CN <NUM> shown in <FIG> may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b.

In this disclosure, the terminology UE may be used as a generic term to identify a device on which one or more V2X application(s) may run. As used herein, the terms UE, WTRU and vehicle may be used interchangeably throughout this disclosure.

<FIG> illustrates an example <NUM> of end-to-end communication between user equipments (UEs) in a vehicle to everything (V2X) platoon, which may be used in combination with any of other embodiments described herein. As illustrated in <FIG>, a UE 202a or 202b may comprise one or more V2X applications <NUM> or <NUM>, a V2X layer <NUM> or <NUM>, and an access stratum (AS) layer <NUM> or <NUM>. The V2X application <NUM> or <NUM> may be an application or an application layer that performs main functions of the V2X application <NUM> or <NUM> such as road safety control, group travel management, and device behavior management while communicating with a V2X application server (V2X AS) to report and receive information related to the function of the V2X application <NUM> or <NUM>. For example, a V2X application in a UE (e.g., a truck) may report the amount of the UE's gasoline to the V2X AS and receive the amounts of other UEs' gasoline for group travel management. Another V2X application in a UE (e.g., a truck travels in the front of the group or platoon) may report road condition to other UEs in the same group so that other UEs may increase or decrease their respective traveling speed based on the road condition reported from the front UE. The V2X AS may collect information from one or more UEs in the same group or platoon and make decision based on the collected information. The V2X AS may send control messages to the UEs or the group to manage the behavior of the UEs or the group. The V2X application <NUM> or <NUM> may send a unicast, multicast, groupcast, or broadcast message to other V2X applications in other UEs in the group. It should be noted that a UE 202a or 202b may include one or more V2X applications <NUM> or <NUM> depending on its functionality or service that the V2X application <NUM> or <NUM> provides. The terms V2X application, V2X application layer, application, application layer, or any combination thereof may be used interchangeably throughout this disclosure.

The V2X layer <NUM> or <NUM> may be a layer that handles communication with other UEs, a V2X control function (CF) or a V2X AS. Since the V2X application <NUM> or <NUM> may require unicast, multicast, or broadcast communication with other V2X applications, the V2X layer <NUM> or <NUM> may handle these types of communication, Specifically, the V2X layer <NUM> or <NUM> may establish unicast, multicast, or broadcast communication for the V2X application <NUM> or <NUM> by configuring and/or communicating with the AS layer <NUM> or <NUM>. For example, the V2X layer <NUM> or <NUM> may inform the AS layer <NUM> or <NUM> of the destination L2 ID for the group communication transmission, based on group identifier provided by the V2X application <NUM> or <NUM>. The V2X layer <NUM> or <NUM> may also inform the AS layer <NUM> or <NUM> of the source L2 ID for the group communication transmission. The V2X layer <NUM> or <NUM> may inform the AS layer <NUM> or <NUM> of the communication type, and QoS parameters including 5QI and range (or transmission range) for the group communication traffic. Based on a transmission profile provided by a V2X CF (or PCF) or a V2X AS and RAN decision, the range may be dynamically (re)configured/adjusted and provided to the AS layer <NUM> or <NUM> for the dynamic group communication operation. The V2X layer <NUM> or <NUM> may inform the AS layer <NUM> or <NUM> of the destination L2 ID for the group communication reception. The V2X layer <NUM> or <NUM> may convert the group identifier provided by the V2X application <NUM> or <NUM> into the destination L2 ID. The terms V2X layer and higher layer may be used interchangeably throughout this disclosure. The V2X layer may perform similar functions of a non-access stratum (NAS) layer. The AS layer <NUM> or <NUM> may be a layer that performs radio specific protocols such as PHY and MAC.

As described above, the V2X application <NUM> or <NUM> may determine the group identifier to perform the group management and pass down the group identifier to the V2X layer <NUM> or <NUM>. For the Tx UE 202a side, the V2X layer <NUM> may convert the group identifier into the form of a destination L2 ID. The destination L2 ID may be passed down from the V2X layer <NUM> to the AS layer <NUM>. The source L2 ID may be self-assigned by the UE 202a and may be provided by the V2X layer <NUM> to the AS layer <NUM>. Furthermore, from the V2X application <NUM>, QoS parameters associated with the group communication, identified by the group identifier, may be indicated to the V2X layer <NUM> via the control interface. The QoS parameters may include the characteristics represented by 5QI, and the range (or transmission range). When the V2X application <NUM> passes down the data packet that is associated with the group identifier, the V2X layer <NUM> may tag the data packet with the configured QoS settings (e.g., 5QI and range) and pass those down to the AS layer <NUM>. The V2X layer <NUM> may also indicate to the AS layer <NUM> that it is for group communication, in order to differentiate it from broadcast traffic. At the Rx UE 202b side, the V2X layer <NUM> may also pass the destination L2 ID converted from the group identifier to the AS layer <NUM>, such that it would be able to manage the receiving operation (e.g., performing HARQ).

When UEs 202a use PC5 group communication for the transmission of V2X messages, PC5 QoS parameters (e.g. VQI) and range may be used to (re)configure the V2X group communication over PC5 interface. When the V2X application <NUM> passes down the data packet that is associated with the group Identifier, the V2X application <NUM> may set the PC5 QoS parameters and range for each group identifier when passing V2X messages to the V2X layer <NUM> for transmission.

<FIG> illustrates an example vehicle to everything (V2X) architecture <NUM>, which may be used in combination of any of other embodiments described herein. As illustrated in <FIG>, UEs A-D 302a-d may include V2X applications <NUM>, <NUM>, <NUM>, <NUM> as described in <FIG>. The UEs A-D 302a-d may be connected to each other with PC5 interface and V2X applications <NUM>, <NUM>, <NUM>, <NUM> may use PC5 interface for the group communication. The UEs A-D 302a-d may also use Uu interface to communicate with RAN <NUM> (e.g., gNB). As illustrated in <FIG>, the control plane may comprise Unified Data Management (UDM) <NUM>, Policy Control Function (PCF) <NUM>, Network Exposure Function (NEF) <NUM>, Application Function (AF) <NUM>, V2X control function (V2X CF) <NUM>, AMF <NUM>, and SMF <NUM>. The user plane may comprise UPF <NUM>. The UEs A-D 302a-d may communicate with PCF <NUM>, V2X CF <NUM> via AMF <NUM>. The UEs A-D 302a-d may also communicate the V2X application server (V2X AS) <NUM> in the data network via the V2X CF <NUM> or the PCF <NUM> (not illustrated in <FIG>). The V2X AS <NUM> may be located in the network (e.g., data network) and may interface with V2X applications <NUM>, <NUM><NUM>, <NUM> installed on UEs A-D 302a-d. The V2X CF <NUM> or PCF <NUM> may handle V2X devices' authorization and provisioning (e.g., V2X policy and parameters configuration towards the UEs A-D 302a-d). The V2X CF <NUM> may be located in a <NUM> CN (e.g., for R16) and may be assumed to be part of the service-based architecture. The functionality of V2X CF <NUM> may be handled by the PCF entity <NUM>. The V2X CF <NUM> (or PCF) may interact with UEs A-D 302a-d using non-access stratum (NAS)-based communication over the control plane interface, for example, using the Namf_Communication_N1N2MessageTransfer/N1MessageNotify service of the AMF <NUM> and the NAS transparent container. V2X UE-to-UE communication may be based on two operation modes: one is over LTE-Uu reference point and the other is over PC5 reference point as illustrated in <FIG>.

V2X services are described herein. A UE running one or more V2X applications may be provisioned with V2X specific parameters. Examples of the V2X specific parameters may include, but are not limited to, a list of supported V2X services such as destination V2X_Layer2_IDs and V2X application server address information such as fully qualified domain name (FQDN) or IP address.

A V2X application running on the UE may send data toward a V2X application server. The V2X application server may collect and process information from vehicle UEs, pedestrian UEs and/or road side units (RSUs), and may provide information to vehicle UEs, pedestrian UEs and/or RSUs. A UE may run multiple V2X applications simultaneously, where each of the V2X application may be associated with a different V2X_Layer2_IDs or V2X group IDs.

Vehicle platooning (or UE platooning) may be one of the main use cases for V2X or enhanced V2X (eV2X). Vehicles (or UEs) of the same platoon may dynamically share information to support platoon operation. For example, a group of trucks heading the same destination may share information to support the delivery operation. Examples of the information may include, but are not limited to, distance between vehicles, relative speed, amount of gas for each vehicles and updates from RSU. Sharing of information may be supported by creating a specific V2X group or V2X platoon within a V2X application.

All the vehicles (or UEs) in the platoon may receive periodic data from a leading vehicle (or leading UE), in order to carry on platoon operations. Platoon members may be provisioned by a V2X control function (V2X CF) and may interact with V2X application server (V2X AS). Platoon members may communicate with each other using PC5 communication, for example, proximity-based service (ProSe).

A V2X AS may assign roles (e.g., leader, follower) to V2X platoon members. A platoon leader may be selected and the selected platoon leader may control the group (e.g., handles join, leave requests, or the like); other devices (or UEs) in the platoon may be assigned as followers. The platoon leader may collect information from the platoon and forward the information to the V2X AS. Examples of the information may include, but are not limited to, statistics, alarms, or requests. The platoon leader may share the information with platoon members, potentially from the V2X AS or other platoon members in other platoons. The platoon follower may send information/statistics/alarms to the platoon leader and other platoon members in other platoons.

As described above, UE-to-UE communication (or vehicle-to-vehicle communication) in a platoon may be done over PC5 communication, which is handled at an access stratum (AS) layer. Thus, the AS layer may need to be configured with a specific range, for example, based on the platoon characteristics such as the number of platoon members, distance between UEs, type of devices, or the like. This range configuration may be handled on the UE by the higher layer (e.g., a V2X layer), which is provisioned with this information. The AS layer may pass this range configuration to a BS (e.g., a gNB), which considers it for resource allocation. Moreover, a platoon may need to be dynamic such that the platoon members that form the platoon may join and leave the platoon group at any moment. This means that the PC5 communication may need to adapt to such dynamic behavior. Thus, dynamically adapting the PC5 communication (e.g., range) configuration based on platoon specific events may be needed. In order to dynamically adapt the PC5 communication configuration, it needs to be determined that: (<NUM>) who should handle this dynamic adaptation; (<NUM>) which procedure should be followed; and (<NUM>) how to obtain a new configuration.

Moreover, platooning may be based on multicast communication and V2X multicast communication over PC5, which is not currently supported in <NUM>. Thus, a procedure to setup a multicast communication needs to be determined.

Lastly, potential tracking of L2 IDs may be identified for unicast and multicast communications. In addition, a multicast group identifier may as well be tracked, thus privacy handling needs to address multicast communications identifiers. Thus, handling privacy of a multicast communication (i.e. peers tracking and multicast group tracking) needs to be determined.

Embodiments that dynamically adapt the PC5 communication (e.g., range) configuration based on platoon specific events are described herein. In such embodiments, a platoon leader (e.g., UE) may be assigned with additional responsibilities. For example, the platoon leader may request a new transmission profile under certain conditions to dynamically adapt PC5 communication. The platoon leader may handle mapping of transmission profile to a range value. The platoon leader may also take local decisions for the platoon for the purpose of a V2X AS.

<FIG> illustrates an example high-level overview <NUM> of vehicle to everything (V2X) platooning, which may be used in combination of any of other embodiments described herein. Platooning related parameters may be configured onto the UE 402a. These platooning related parameters may be pre-configured or received at startup and may be updated at any time by a V2X CF (or PCF) and/or a V2X AS. For example, at step <NUM>, the UE 402a may receive, from a V2X CF <NUM> (or PCF) or a V2X AS <NUM>, a V2X provisioning message that includes such parameters related to the V2X platooning. These parameters may be received by the V2X application <NUM> and/or V2X layer (also referred to as higher layer <NUM>) running on the V2X device (i.e. UE 402a). These parameters may be a list of V2X application identifiers that the device is authorized to run. For each application identifier, these parameters may include a list of V2X group identifiers for which the device is a member. For each group identifier, the parameters may include, but are not limited to, a role (e.g. platoon leader or follower) or the like. The parameters such as the maximum number of members allowed, transmission profile, priority, validity timer, validity location or the like may be configured on the selected leader only and/or for each group. The parameters such as a range mapping table and/or mapping of coverage to range may be configured on the selected leader only. In addition, configuration may have an associated validity time and/or validity location, allowing many configuration entries (active/passive) to be selected by the UE (or the higher layer <NUM>). At step <NUM>, the UE <NUM> may locally store and/or maintain these parameters including the transmission profile.

The transmission profile that includes QoS parameters (e.g., transmission rate, maximum end-to-end latency, etc.) may be extended with V2X specific parameters that are used to determine the range to be configured at the AS layer <NUM>. For example, the following V2X specific parameters may be included per platoon: device (e.g., platoon members) maximum size (e.g., length, width, height), distance between devices (e.g., front/back, on the side), platoon arrangement (e.g., single line, double line (i.e. two devices side-by-side), etc.), type of required communication (e.g., each device must be able to reach all other devices, each device must be able to reach at least one other device, etc.), number of platoon members, or the like.

As described above, multiple V2X applications may run on a device and for each of these applications, many multicast groups (i.e. group identifiers) may exist, concurrently. The group identifiers may be unique per application, thus a combination of V2X application identifier and group identifier values may be used to uniquely identify each group. This combination may be referred to as a group ID. This combination may enable a peer UE 402b receiving data destined to a group ID to determine the associated multicast group and application.

Each group may have a different configuration and the communication layer (i.e. PC5 in this case) may adapt its behavior to such configuration on a per packet basis.

The higher layer <NUM> or V2X layer may handle the communication and configuration with the access stratum (AS) layer <NUM>. For this purpose, at step <NUM>, the higher layer <NUM> may map the transmission profile to AS layer parameters such as a range. For example, the higher layer <NUM> may determine the range to be configured on the AS layer <NUM> using: (<NUM>) the configured transmission profile to calculate the required coverage; and/or (<NUM>) the configured range mapping table specifying range values corresponding to the required coverage.

The required platoon coverage may be calculated by considering, for example, the number of members, their size, the platoon arrangement or the like. The obtained coverage value may be used with the range mapping table to determine the range that is needed. A range mapping table may have different forms. For example, it may contain a mapping of platoon coverage to a range (e.g., small, medium, large) to be configured at the AS layer <NUM>. The range mapping table may be preconfigured at the UE 402a or received from the V2X CF <NUM> (or PCF) or the V2X AS <NUM>.

The AS layer <NUM> may maintain a grouplD-to-range table for V2X group ID/communication parameters (e.g., range) mapping. At step <NUM>, the AS layer <NUM> may configure the RAN <NUM> with a list of configured group IDs and their associated range.

A V2X CF <NUM> (or PCF) may also configure the RAN <NUM> with V2X group specific parameters or information about whether a certain UE is allowed to be a platoon leader or request PC5 resources for a particular transmission range. Specifically, at step <NUM>, the V2X CF <NUM> (or PCF) may send a RAN configuration request message to the AMF <NUM>. At step <NUM>, the AMF <NUM> may forward the configuration request message to the RAN <NUM>. The RAN configuration request message or the configuration request message may include a V2X group ID, role, maxim number of members, maximum range, priority level, or the like. Once the RAN <NUM> receives the configuration request message, the RAN <NUM> may locally store or maintain the contents of the configuration message such as a group ID and maximum range. When the UE 402a initiates the RAN configuration at step <NUM>, the RAN <NUM> may accept or reject the configuration requests from UEs based on these parameters. For example, the RAN <NUM> may accept the configuration request from the UE 402a if the range received from the UE 402a is less than the maximum range received from the V2X CF <NUM> (or PCF). Similarly, the RAN <NUM> may reject the configuration request from the UE 402a if the range received from the UE 402a is greater than the maximum range received from the V2X CF <NUM> (or PCF). The RAN <NUM> may reserve resource (e.g., channels)_when the configuration request from a UE 402a is accepted. The RAN <NUM> and AS layer <NUM> may enforce communication parameters (e.g., range) to the platoon members. Once the RAN configuration between the AS layer <NUM> and the RAN <NUM> are completed, the AS layer <NUM> and RAN <NUM> may apply the range for the V2X group associated with the range. For example, the V2X application <NUM> may send data with a group ID to the AS layer <NUM> at step <NUM>. The AS layer <NUM> may send the data with the group ID to the platoon member (i.e. UE 402b) within the range configured by the AS layer <NUM> and RAN <NUM> at step <NUM>.

A platoon role configured on the UEs 402a, 402b may determine the UE's behavior. For example, the UE 402a selected as the platoon leader may share configuration information with platoon members (e.g., UE 402b) and dynamically adapt the communication parameters when required, for example, by querying the V2X AS <NUM> for new parameters under certain conditions. For example, a platoon leader may receive a new transmission profile and map the transmission profile to a range. The platoon leader may then forward the result to the platoon members. Specifically, if the number of members joining the platoon reaches the maximum number of platoon members allowed at step <NUM>, the platoon leader (i.e. UE 402a) may request a new transmission profile from the V2X AS <NUM>, recalculate the range using the new transmission profile and the range mapping table, and configure the AS layer with a new range value associated with the group ID at step <NUM>. This new configuration may, for example, result in an increase (or decrease) of transmission power, modulation and coding scheme (MCS), number of retransmissions, or the like. In addition, the platoon leader (i.e. UE 402a) may configure the platoon members (. g, UE 402b) with the new range value so that these platoon members (e.g., UE 402b) may also adapt their transmission by re-configuring their AS layer as described herein. In order to get the new transmission profile, the UE 402a may send a modification request message <NUM> to the V2X CF <NUM> (or PCF) or the V2X AS <NUM> at step <NUM> and receive a modification accept message <NUM> from the V2X CF <NUM> (or PCF) or the V2X AS <NUM> at step <NUM>. Once the new transmission profile is received, the UE 402a may locally maintain the new transmission profile with a group ID and a role at step <NUM>. The UE 402a may then determine a new range based on the new transmission profile and a range mapping table at step <NUM>.

Roles in a platoon are described herein. As described above, a V2X AS may assign roles to V2X platoon members. The roles may be a leader or a follower. A platoon leader may be selected and control the group; other devices in the platoon may be followers. The platoon leader may interact with devices (i.e. followers) within the platoon and with a V2X CF (or PCF) and a V2X AS. The platoon leader may collect information from the platoon and forward this information to the V2X AS (e.g. statistics, alarms, requests, or the like). The platoon leader may share information with the platoon, potentially from the V2X AS or other platoon members. The platoon leader may receive a range mapping table and save it locally. The platoon leader may receive a transmission profile and save it locally. The platoon leader may fetch or request a new transmission profile when it is needed (e.g., when more than the number of allowed UEs are joining the group or after some validity period). The platoon member may calculate the required coverage for a specific platoon (e.g., using the transmission profile) and maps it to a specific range (e.g., using the range mapping table). The platoon leader may configure the AS layer with the range and grouplD. The platoon leader may forward (e.g., multicasts over PC5) the range value to the platoon members. The platoon leader may function as a local decision maker (i.e. local decisions are forwarded to platoon members (followers)) and eventually to the V2X AS, for quick reaction (compared to going to the V2X CF and/or V2X AS) and to offload the network/V2X CF/V2X AS (local decisions/tasks). Examples of local decision may include, but not limited to: whether to increase the range because of the increased number of members, whether to increase the allowed number of members, whether to split a group which has become too big (i.e. too many members), and whether to select a platoon leader for the newly formed group (i.e. after the split).

The platoon follower may interact with a platoon leader (directly/indirectly) and other platoon members. The platoon follower may send information/statistics/alarms to a platoon leader. In addition, the platoon follower may receive communication related configuration from the platoon leader (e.g., range) and configure the AS layer accordingly.

<FIG> illustrates an example platoon configuration and PC5 communication setup <NUM>, which may be used in combination of any of other embodiments described herein. As illustrated in <FIG>, at step <NUM>, a V2X device (e.g., UE 502a or UE 502b) that has a V2X application <NUM>, a higher layer <NUM> (or V2X layer) and an AS layer <NUM> may initially attach to the network that has V2X capabilities are enabled. After the UE 502a is attached to the network, the first steps for platoon creation may be the platoon leader selection and its provisioning. This may be handled by the V2X AS <NUM> (e.g., for the platoon leader selection at step <NUM>) and the V2X CF (or PCF) (e.g., for the provisioning at step <NUM>). Specifically, the V2X CF <NUM> (or PCF) may send a V2X provisioning message to the UE 502a at step <NUM> after the V2X CF <NUM> (or PCF) is triggered by a configuration message from the V2X AS at step <NUM>. The V2X provisioning message may include, but is not limited to, the role (e.g., a leader, a member, or a follower), V2X application identifiers and V2X group identifiers. A more complete list may be provided as described above. The information about the role of a particular UE may also come from the V2X application <NUM> running on the UE 502a.

The V2X AS <NUM> may configure platoons based on various factors. Examples of such factors may include, but are not limited to, UE's location, UE's capabilities and capacities, number of devices in the platoon, amount of time the UE has been/not been a leader, or information stored in unified data management (UDM).

The V2X device (e.g., UE 502a or UE 502b) may be provisioned by the V2X CF <NUM> (or PCF) at startup, during registration or UE configuration update procedures. The V2X device may register to the network and may provide identification information, its capabilities (e.g., V2X support, or V2X applications), its capacities (e.g., maximum range, speed, device type, or the like), location information, or the like. The V2X device may be provisioned with V2X specific parameters. The V2X device may also be configured later from the V2X AS <NUM> via the V1 interface.

The V2X device (e.g., UE 502a or UE 502b) may receive the complete configuration or a minimal configuration in the V2X provisioning message at step <NUM>. The V2X device (e.g., UE 502a) may locally store the configuration information such as a group ID and a role. If it is a minimal configuration, the V2X device may be configured with the role and the group ID. In the latter case, the V2X device (e.g., UE 502a) configured as a platoon leader may request a transmission profile, range mapping table, or the like when it is needed at step <NUM>. For example, the UE 502a (i.e. the platoon leader) may send a message requesting a transmission profile when a V2X application <NUM> is started, initialized, or running. This is illustrated at steps <NUM> and <NUM>, and steps <NUM> and <NUM> in <FIG>, which are two alternatives for the UE 502a (i.e. the platoon leader) to fetch the transmission profile associated to the specified group. The steps <NUM> and <NUM> illustrates how the profile can be obtained from the V2X CF (or PCF). Specifically, the higher layer <NUM> (or V2X layer) may send a get request message that includes a group ID and a role to the V2X CF (or PCF) at step <NUM>. The higher layer <NUM> (or V2X layer) may receive a get response message that includes a maximum number of allowed members and a transmission profile from the V2X CF <NUM> (or PCF) and forward the transmission profile to the V2X application <NUM> at step <NUM>. Alternatively, the steps <NUM> and <NUM> illustrates how the profile may be obtained from the V2X AS <NUM>. Specifically, the V2X application <NUM> may send a get request message that includes a group ID and a role to the V2X AS at step <NUM>. The V2X application <NUM> may receive a get response message that includes a maximum number of allowed members and a transmission profile from the V2X AS <NUM> and forward the transmission profile to the higher layer <NUM> (or V2X layer) at step <NUM>. The same transmission profile may be received using either of these alternatives (i.e. steps <NUM>, <NUM> and steps <NUM>, <NUM>).

The transmission profile received from the V2X CF <NUM> (or PCF) or the V2X AS <NUM> may be per group ID (i.e. per V2X application) and may be only sent to the platoon leader, UE 502a, (i.e. not to the followers). At step <NUM>, the platoon leader (i.e. UE 502a) may locally store and maintain the group ID, the role, and the transmission profile. At step <NUM>, the platoon leader (i.e. UE 502a) may use this transmission profile to determine the range to be configured at the AS layer. The range may be determined based on a range mapping table that is associated with the transmission profile. Thus, the range may be different per a transmission profile. The range mapping table may be received or downloaded once from the network, but it may be received or downloaded multiple times from the network when it is needed. Alternative or additionally, the range mapping table may be pre-stored or predetermined in UEs 502a, 502b.

The range mapping table may be only sent to the platoon leader. The range mapping table may be provisioned at startup or may be queried later by the platoon leader (e.g., UE 502a) (as the transmission profile). The range mapping table may have different forms or formats. For example, it may comprise a mapping of platoon coverage to range (e.g., small, medium, large) to be configured at the AS layer <NUM>. The platoon coverage may be obtained by calculating number of members, their size, arrangement, or the like. The obtained values may be used with the range mapping table. It may be configured only once. It is however possible for the V2X device (e.g., UE 502a, UE 502b) to fetch an updated range mapping table (e.g., to refresh it) in case the range mapping table has been downloaded a long time ago. The V2X CF <NUM> (or PCF) or V2X AS <NUM> may also decide to re-send the range mapping table with the transmission profile from time to time or when it's updated.

The platoon leader (e.g., UE 502a) may create the V2X platoon or group that comprises the platoon leader and platoon followers or members. For example, the platoon leader (e.g., UE 502a) may enable the multicast communication for a specific V2X group. As described above, PC5 communication is handled at the AS layer <NUM>. Thus, the platoon leader (e.g., UE 502a) may need to configure the AS layer <NUM> prior to the platoon creation and enablement of communication between platoon members.

The platoon leader (e.g., UE 502a) may configure the AS layer <NUM> with received configuration impacting the AS layer <NUM>, for example, range, priority and associated V2X group ID. The AS layer <NUM> may keep track of the received configuration and apply the specified range when transmitting data is related to the associated V2X group ID. In order to apply the range to the V2X platoon, the platoon leader (e.g., UE 502a) may need to configure the range with the RAN <NUM> and other platoon members (e.g., UE 502b). Specifically, once the range is determined at step <NUM>, the V2X application <NUM> and/or the higher layer <NUM> (or V2X layer) may send a set request message to the AS layer <NUM> at step <NUM> to configure the AS layer <NUM> with the range. This set request message may include the range and a group ID associated with the range. The AS layer <NUM> may then send another set request message to the RAN <NUM> (e.g., a gNB) with the range and the group ID at step <NUM>. If the range (i.e. requested range) received from the AS layer <NUM> is smaller than the maximum range configured or predetermined in the RAN <NUM>, the RAN <NUM> may accept the range (i.e. requested range) and allocate resources (e.g., channels) for the UE 502a at step <NUM>. The RAN <NUM> may send a set response message to the UE 502a indicating which resources (e.g., channels) the UE 502a or the V2X platoon may use at step <NUM>. If the range (i.e. requested range) received from the AS layer <NUM> is greater than the maximum range configured or predetermined in the RAN <NUM>, the RAN <NUM> may send a set response message to the UE 502a indicating that the requested range is not accepted at step <NUM>. The set response message transmitted from the RAN <NUM> may also include a group ID, a range (e.g., accepted range, rejected range, or maximum range allowed in the RAN <NUM>), and/or an indicator indicating the acceptance or rejection of the range. The RAN <NUM> (e.g., gNB) may locally store or maintain the group ID, the maximum range, the requested range, or the like at step <NUM>. Once the AS layer <NUM> receives the set response message from the RAN <NUM>, the AS layer <NUM> may send another set response message to the higher layer <NUM> (or V2X layer) and the V2X application <NUM> with the range (e.g., accepted range, rejected range, or maximum range allowed in the RAN <NUM>) at step <NUM>.

As described above, a V2X device (e.g., UE 502b) may be configured as a member of multiple V2X groups and each group may have different communication requirements (i.e. a different configuration). In this case, there can be a single same platoon leader (e.g., UE 502a) for each group or multiple different platoon leaders for each group. To support per group configuration, the AS layer <NUM> may maintain a grouplD-to-range table for V2X group ID vs specific configuration (e.g., range). The configuration may be applied on a per-packet basis (e.g., using the groupID-to-range table). As well, a different leader for each group may be selected or a specific device may be selected as the leader for many platoons. In any case, each device may be configured with a role per platoon. For example, the device selected as a leader may be leader in multiple platoons or in one only.

The platoon leader (e.g., UE 502a) may then advertise its presence, specifying the group ID and listen for followers' join request. For example, as illustrated in <FIG>, at step <NUM>, the V2X application <NUM> of the platoon leader 505a may send a V2X send message to the AS layer <NUM> with the group ID. The AS layer <NUM> may send the V2X send message to the UE 502b with the group ID. Other devices (i.e. platoon members) may also be configured with their role and V2X group ID. These devices may wait for the platoon creation. For example, they may configure their AS layer with minimal parameters (e.g. pre-configured generic range and group ID) and they may listen on PC5 for multicast messages from the platoon leader (e.g., UE 502a). Once communication is established (i.e. followers have received a message for the group ID), these devices (i.e. followers) may contact the platoon leader (e.g., UE 502a) to join the group. The platoon leader (e.g., UE 502a) may configure the followers with communication parameters such as range specific to the group ID or the like. The followers may also configure their AS layer with the received parameters such as specific range and group ID. For example before the UE 502b become a member of the V2X platoon where the UE 502a is the platoon leader, the UE 502b may request the platoon leader (i.e. UE 502a) to join the V2X group as a follower at step <NUM>. The platoon leader (i.e. US 502a) may accept or reject the request. If the request is accepted, the platoon leader (i.e. UE 502a) may send the range to the UE 502b for this V2X group. The UE 502b may configure its AS layer with the range.

In an embodiment, the multicast communication may be initiated by the platoon leader sending a message (e.g., advertisement message) using the platoon leader's L2 ID as the source L2 ID and the destination L2 ID is set to the group ID. This message may specify the required QoS parameters that the UE who want to join needs to support. There may be no QoS parameters negotiation. The advertisement message may be sent by the platoon leader using a configured (in the UE or by the V2X CF or PCF) broadcast layer <NUM> destination ID. Interested V2X UE may use this broadcast layer <NUM> ID to tune to the PC5 broadcast information. The PC5 broadcast information may provide information about the source/destination ID corresponding to particular V2X group/multicast communication. It should be noted that if the platoon leader decides to change the group ID of the multicast communication, it may need to update the information sent on the broadcast PC5 channel. The source/destination ID broadcasted using the broadcast PC5 group ID may also be used by the V2X UEs (e.g., follower UEs) to establish the unicast link with the platoon leader if needed.

All devices registered as followers (e.g., platoon members) may listen for this specific destination L2 ID. The received message may be passed up to the V2X layer, which is able to decode the message since it is configured with the security related parameters (e.g., keys) that makes PC5 communication secured.

The followers that want to contact the platoon leader (e.g., to join the group) may use their own L2 ID as the source L2 ID and the leader's L2 ID as the destination L2 ID. The leader's L2 ID may be learned from the multicast message. The group ID may be specified in a field of the join request. The leader may save the follower's L2 ID and may use it if needed for unicast communication. For example, if the platoon leader wants to configure a follower as the new leader, it may directly contact the follower using its L2 ID.

The required/advertised QoS parameters for a specific group ID may change, for example, if new QoS parameters are received as part of the transmission profile update procedure (i.e. Get REQ/Get RSP as illustrated in <FIG>). In this case, a new advertisement message may be multicast, including the new required QoS parameters. All members may need to adapt to the new QoS parameters.

For privacy reasons (e.g., to avoid tracking an L2 ID), the unicast (or destination) L2 ID of the platoon leader and followers may need to be changed periodically for ongoing communication. For multicast communication, since the group ID is used as the destination, the potential tracking issue may also apply to this case. The multicast identifier (i.e. group ID) may also need to be changed periodically. Thus, a method for changing the multicast identifier (group ID) needs to be determined.

Embodiments for a platoon leader and follower L2 ID change are described herein.

The platoon leader may change its L2 ID periodically (e.g., based on time, location, request from upper layer or peer UE, or the like). The platoon leader may generate a new L2 ID and multicast it to its followers. A platoon leader may use a distinct L2 ID per multicast group. If the same L2 ID is used for many multicast groups, then the new L2 ID may be multicast to all these groups. The leader may multicast its L2 ID few times to make sure all followers received it or may request a response from the followers. A specific time to apply this new L2 ID (i.e. validity time) may be specified to ensure that all followers will use the new L2 ID at the same time.

Followers may change their L2 ID as well periodically (e.g., same triggers as leader). The follower may generate a new L2 ID and send it to the leader using the join message. The current L2 ID may be specified as well as the new L2 ID. The leader receiving this join message may know that the new L2 ID needs to be kept and used in following communication. A join acknowledgement may be sent back to the follower still using the old L2 ID as the destination L2 ID. Further communication may use the new L2 ID. Followers that are allowed to multicast to the group and receive unicast messages from other members may use the multicast method described for the leader (above) to let the members know their new L2 ID.

Embodiments for group ID change are described herein.

All followers (i.e. devices that have successfully joined the multicast group) may be configured by the platoon leader (or V2X CF) with a new group ID, possibly security parameters, and upper layer identifier that may be applied at a specific time as an example. All followers and platoon leader may then start using this new configuration at the same time and stop using the previous group ID for communication. To make sure that all devices received the new group ID, the leader may multicast it multiple times or may request a response from the followers.

The original information (e.g., group ID and security parameters) may be still maintained at the V2X CF and/or V2X AS and at the leader. Devices may be still provisioned with this information.

A multicast message using the original group ID (with related security parameters and possibly upper layer identifier) may continue to be sent periodically by the platoon leader in case devices listening to the group ID would like to join. Devices that want to join may use the provisioned information and once the join request is accepted, these devices may be reconfigured by the platoon leader with the new parameters, on a secured link. These new followers may then immediately start using the new group ID and security parameters, and receive the multicast messages.

<FIG> illustrates an example <NUM> of range adaptation based on a new transmission profile, which may be used in combination of any of other embodiments described herein. In this example <NUM>, it is assumed that a V2X platoon (or group) is already formed and V2X communication between the platoon members is already established as described above. As illustrated in <FIG>, a platoon leader 602a may comprise a V2X application <NUM>, a higher layer <NUM> (or V2X layer), and an access stratum (AS) layer <NUM>. The platoon leader 602a may be configured with various parameters for V2X communication and platoon support as described above. Examples of those parameters may include, but are not limited to, a range mapping table, a group ID, a transmission profile and maximum number of allowed platoon or group members. As described above, the platoon leader 602a may determine the range to be configured at the AS layer <NUM> and share this range value with the platoon members such as UE 602b. UEs or devices that join the platoon or group later may also be configured with this range value.

For example, in case where the number of UEs joining the V2X platoon (or group) reaches the maximum number of allowed members in the platoon at step <NUM> (or a threshold is reached), the platoon leader 602a may request a new transmission profile to obtain additional coverage (i.e. range), which maps to a new range, allowing all platoon members to communicate with each other. In case where the number of UEs joining the V2X platoon (or group) does not reach the maximum number allowed (or a threshold is not reached), the platoon leader 602a may not request a new transmission profile.

Specifically, at step <NUM> or step <NUM>, the platoon leader 602a may query the V2X CF <NUM> (or PCF) or V2X AS <NUM> to obtain a new transmission profile. For example, when the number of UEs joining the V2X platoon exceeds the maximum number, the V2X application <NUM> may send a request to the higher layer <NUM> (or V2X layer) indicating that the threshold is reached at step <NUM>. The higher layer <NUM> (or V2X layer) may then generate a modification request message requesting the new transmission profile. The modification request message may include, but are not limited to, a group ID associated with the V2X application <NUM>, a current number of platoon members, and a number of UEs joining the V2X platoon. At step <NUM>, the higher layer <NUM> (or V2X layer) may transmit the modification request message to the V2X CF <NUM> (or PCF) through RAN <NUM> and AMF <NUM>. The V2X CF <NUM> (or PCF) or V2X AS <NUM> may accept the modification request and provide a new transmission profile or it may reject the modification request. For example, if the modification request is accepted by the V2X CF <NUM> (or PCF) or V2X AS <NUM>, at step <NUM>, the V2X CF <NUM> (or PCF) may transmit a modification accept message to the higher layer <NUM>. The modification accept message may include, but are not limited to, a new maximum number of platoon members, and a new transmission profile associated with the group ID. Although it is not illustrated in <FIG>, if the modification request is not accepted (i.e. rejected) by the V2X CF <NUM> (or PCF) or V2X AS <NUM>, a modification reject message may be returned to the higher layer <NUM> (or V2X layer) with a reason code. The higher layer <NUM> (or V2X layer) may then send the response message to the V2X application <NUM> at step <NUM> indicating whether the request at step <NUM> is accepted or not. The response message at step <NUM> may include, but is not limited to, an indicator indicating whether the request is accepted or not, the new maximum number of platoon members, the new transmission profile, and/or the reason code depending on the result. At step <NUM>, the V2X CF <NUM> (or PCF) may exchange configuration request and response messages with the V2X AS <NUM> to obtain a new transmission profile and/or transmission range and then the V2X CF (or PCF) may configure the network (i.e. RAN <NUM>) with the new transmission profile and/or transmission range.

Alternatively or additionally, when the number of UEs joining the V2X platoon exceeds the maximum number of allowed UEs, the V2X application <NUM> may generate and send a modification request message at step <NUM> to request the new transmission profile. The modification request message may include, but are not limited to, a group ID associated with the V2X application <NUM>, current number of platoon members, and number of UEs joining the V2X platoon. The modification request message may be transmitted to the V2X AS <NUM> through V1 interface as shown in <FIG>. The V2X AS <NUM> may accept the modification request and provide a new transmission profile or it may reject the modification request. For example, if the modification request is accepted by the V2X AS <NUM>, at step <NUM>, the V2X AS <NUM> may transmit a modification accept message to the V2X application <NUM>. The modification accept message may include, but are not limited to, a new maximum number of platoon members, and a new transmission profile associated with the group ID. At step <NUM>, once the modification request is accepted, the V2X AS <NUM> may also exchange configuration request and response messages with the V2X CF <NUM> (or PCF) to configure the network (i.e. RAN <NUM>) with the new transmission profile and/or transmission range. Although it is not illustrated in <FIG>, if the modification request is not accepted (i.e. rejected) by the V2X AS <NUM>, a modification reject message may be returned to the V2X application <NUM> with a reason code. Once the V2X application <NUM> receives the modification accept message at step <NUM>, the V2X application may send the new transmission profile to the higher layer <NUM> (or V2X layer) at step <NUM> to configure the AS layer <NUM> with the new transmission profile.

The V2X CF <NUM> (or PCF) or V2X AS <NUM> may optionally configure the RAN <NUM> with a new maximum range associated with the new transmission file. For example, at step <NUM>, the V2X CF <NUM> (or PCF) may transmit a RAN configuration request message to the AMF <NUM>. The RAN configuration request message may include a V2X group ID, a new maximum range associated with the new transmission profile, and the like. Upon receiving the RAN configuration request message, at step <NUM>, the AMF <NUM> may send a configuration request message to the RAN <NUM> (or a base station). The configuration request message may also include a V2X group ID, a new maximum range associated with the new transmission profile. Upon receiving the configuration request message, the RAN <NUM> may configure the maximum range of the V2X platoon group that requested the new transmission profile.

Once the modification accept message is received at step <NUM> or step <NUM>, the UE 602a may locally maintain the new maximum number, the new transmission profile, a group ID associated with the new transmission profile, and its role in the V2X platoon. At step <NUM>, the UE 602a, the platoon leader, may then determine the range associated with the new transmission profile and configure its AS layer <NUM> with the new range value. For example, the UE 602a may calculate a coverage value based on the new transmission profile. The UE 602a may then compare the coverage value with a range mapping table, and determine, based on the new range mapping table, the range associated with the new transmission profile. Specifically, the V2X application <NUM> or the higher layer <NUM> (or V2X layer) may calculate the coverage that is needed, by considering the current number of members, their size, the platoon arrangement, the distance between the devices, or the like. These parameters may be specified in the transmission profile as described above. Once the required coverage is calculated, the higher layer <NUM> may use the range mapping table to figure out which range value should be configured at the AS layer <NUM>. For example, a platoon may comprise devices of large size (e.g., trucks with long van), maximum <NUM> members, arrangement of platoon 1x1, or the like. These parameters may map to a range value of medium (e.g., range value = medium). If a new transmission profile increases the maximum number of members to <NUM> as an example, then the new range value obtained may be large (e.g., range value = large). In another example, a platoon may comprise devices of small size (drone), maximum <NUM> members, arrangement of platoon 4x5, or the like. This may map to a range value of small (e.g., range value = small). The platoon leader 602a may save the new range locally with the associated group ID. It is noted that the range mapping table may be predetermined in the UE 602a or received from the V2X CF <NUM> (or PCF) or the V2X AS <NUM> during the V2X provisioning procedure ad described above.

Once the range is determined, the V2X application <NUM> or the higher layer <NUM> (or V2X layer) may send a set request message to the AS layer <NUM> at step <NUM> to configure the AS layer <NUM>. This set request message may include the range and a group ID associated with the range. The AS layer <NUM> may then send another set request message to the RAN <NUM> (e.g., a gNB) with the range and the group ID at step <NUM>. If the range (i.e. requested range) received from the AS layer <NUM> is smaller than the maximum range configured or predetermined in the RAN <NUM>, the RAN <NUM> may accept the range (i.e. requested range) and allocate resources (e.g., channels) for the UE 602a or the V2X group associated with the UE 602a at step <NUM>. The RAN <NUM> may send a set response message to the UE 602a indicating which resources (e.g., channels) the UE 602a or the V2X platoon may use at step <NUM>. If the range (i.e. requested range) received from the AS layer <NUM> is greater than the maximum range configured or predetermined in the RAN <NUM>, the RAN <NUM> may send a set response message to the UE 602a indicating that the requested range is not accepted at step <NUM>. The set response message transmitted from the RAN <NUM> may also include a group ID and a range (e.g., accepted range, rejected range, or maximum range allowed in the RAN <NUM>). The RAN <NUM> (e.g., gNB) may locally store or maintain the group ID, the maximum range, the requested range, or the like at step <NUM>. Once the AS layer <NUM> receives the set response message from the RAN <NUM>, the AS layer <NUM> may send another set response message to the higher layer <NUM> (or V2X layer) and the V2X application <NUM> with the range (e.g., accepted range, rejected range, or maximum range allowed in the RAN <NUM>) at step <NUM>.

At step <NUM>, the new range (i.e. accepted range) may be sent to all followers or members of the V2X platoon to re-configure their respective AS layer to apply the new range value. The new transmission profile may needs to be applied to the existing V2X platoon. For example, the new transmission profile may replace the existing transmission profile to be applied to the existing V2X platoon. Specifically, a V2X platoon identifier (i.e. group ID) may initially be associated with the first received transmission profile. After the new transmission profile is received, the same V2X platoon identifier (i.e. grouplD) may be associated with the new transmission profile.

The V2X AS <NUM> may also configure the V2X CF <NUM> (or PCF) with the new range. This is to allow the V2X CF <NUM> (or PCF) to forward that new configuration to the concerned RAN. It should be noted that configuring the RAN <NUM> at this point may be optional The configuration of the RAN <NUM> may not be required if the new range allocated for this platoon is smaller than the maximum range that was previously configured at the RAN <NUM>.

<FIG> illustrates an example procedure <NUM> for range adaption based on a new transmission profile, which may be used in combination of any of other embodiments described herein. For example, at step <NUM>, a UE may receive, from a V2X CF (or PCF) or a V2X AS, a V2X provisioning message that includes configuration information for the V2X platoon such as a transmission profile. The transmission profile may include quality of service (QoS) parameters, V2X specific parameters, or the like. The QoS parameters may include a transmission rate, maximum end-to-end latency, or the like. The V2X specific parameters may include, but are not limited to, a maximum size of a UE, a distance between UEs in the V2X platoon, an arrangement of the V2X platoon, a type of required communication between UEs in the V2X platoon, a number of UEs in the V2X platoon and a maximum number of UEs in the V2X platoon. The V2X provisioning message may also include a V2X group ID, a maximum number of UEs in a V2X platoon, a range mapping table, or the like.

Upon receiving the V2X provisioning message, at step <NUM>, the UE may determine, based on the transmission profile, a first range that is used to configure the PC5 communication (e.g., AS layers) of other UEs (i.e. followers or members) associated with the V2X platoon. Specifically, the UE may calculate a coverage value using the QoS parameters and/or the V2X specific parameters in the transmission profile. Once the UE obtained the coverage value, the UE may compare the coverage value with data in the range mapping table and determine, based on the range mapping table, the first range. The range determined based on the range mapping table may indicate small range, medium range, or large range. Examples of parameters from the transmission profile and used to calculate the range may include, but are not limited to, the distance that a signal can reach within a platoon, the distance between devices within a platoon (e.g., from the first vehicle to the last vehicle), a number of device in a platoon, a transmission power. The term range and transmission range may be interchangeably used throughout this disclosure.

Upon determining the first range, the UE may transmit, to a base station (BS) associated with the RAN, a request message that includes the first range and an indicator indicating that resource allocation associated with the first range is requested to the RAN. If RAN accepts the request (i.e. the first range), the RAN may allocate resources (e.g., channels) for the V2X platoon. The RAN (e.g., BS) may then send a response message to the UE. The response message may include the first range, the resource allocation associate with the first range, and an indicator indicating that the resource allocation associated with the first range is accepted by the RAN. The UE may then transmit, to the members of the V2X platoon, the first range and each member in the platoon may configure its respective PC5 communication with the received range. Specifically, each member may configure its respective AS layer to adapt the coverage of the V2X platoon associated with the first range.

Once the PC5 communication of the V2X platoon is configured with the first range, at step <NUM>, the UE may monitor for one or more V2X specific events that may trigger the reconfiguration of the first range. If one or more V2X specific events are occurred, the UE may transmit a modification request message to the V2X CF (or PCF) or the V2X AS at step <NUM>. If one or more V2X specific events have not occurred, the UE may keep monitoring the V2X specific events at step <NUM>. For example, when a number of UEs joining the V2X platoon exceeds a maximum number of allowed UEs in the V2X platoon (i.e. V2X specific event occurred), the UE may transmit, to the V2X CF (or PCF) or the V2X AS, a modification request message requesting a second transmission profile at step <NUM>. The UE may then receive, from the V2X CF (or PCF) or the V2X AS, a modification response message that includes the second transmission profile at step <NUM>. Similar to the first transmission profile, the second transmission profile may include one or more quality of service (QoS) parameters and one or more V2X specific parameters. The one or more V2X specific parameters in the second transmission profile may comprise a maximum size of a UE, a distance between UEs in the V2X platoon, an arrangement of the V2X platoon, a type of required communication between UEs in the V2X platoon, a number of UEs in the V2X platoon and a maximum number of UEs in the V2X platoon.

Upon receiving the modification response message, at step <NUM>, the UE may determine, based on the second transmission profile, a second range that is used to reconfigure the PC5 communication of other UEs (e.g., followers or members) associated with the V2X platoon. Specifically, the UE may calculate the coverage value using the QoS parameters and/or the V2X specific parameters in the second transmission profile. Once the UE obtained the new coverage value, the UE may compare the coverage value with data in the range mapping table. The UE may then determine, based on the range mapping table, a new range (or second range). The new range determined based on the range mapping table may indicate small range, medium range, or large range Examples of the V2X parameters specified in the transmission profile may include, but are not limited to, the distance that a signal can reach within a platoon, the distance between devices within a platoon (e.g., from the first vehicle to the last vehicle), a number of device in a platoon, a transmission power.

Once the new range is determined, the UE may transmit, to the base station (BS) associated with the RAN, a request message that includes the new range and an indicator indicating that resource allocation associated with the new range is requested to the RAN at step <NUM>. The RAN may compare the new range to a maximum range that is predetermined or configured by the V2X CF (or PCF). If the RAN accepts the request (i.e. the new range is less than the maximum range), the RAN may allocate resources (e.g., channels) for the V2X platoon. The RAN (e.g., BS) may then send a response message to the UE and the UE may receive the response message at step <NUM>. The response message may include the new range, the resource allocation associated with the new range, and an indicator indicating that the resource allocation associated with the new range is accepted by the RAN. The UE may then transmit, to the members of the V2X platoon, the new range at step <NUM>. Each member in the platoon may configure its respective PC5 communication. Specifically, each member may configure its respective AS layer to adapt the PC5 communication of the V2X platoon associated with the second range.

The RAN may need to be configured with a range for resource allocation. This configuration may be received from the V2X CF (or PCF) via the AMF. As described above, the range may be applicable per platoon. Thus, the associated group ID may be specified as well. The RAN may maintain and enforce this range. The V2X CF (or PCF) may also configure other parameters such as priority level. The RAN configuration from the V2X CF (or PCF) and UE side is illustrated in <FIG> and <FIG>.

The RAN may be configured (e.g., as part of the UE profile at the RAN) with the maximum allowed range and may adapt its transmission with the value specified by the platoon leader. For example, the platoon leader may be configured with a range value smaller than the allowed maximum range value configured at the RAN. The platoon leader may configure its AS layer with its range value, which may then configure the RAN with this same value. This value may then be used for PC5 communication. The platoon leader may eventually request a range increase (or decrease) which goes up to the RAN. Examples of such triggers may be members joining/leaving the group. The RAN may accept/reject the request depending of its maximum allowed range configuration (previously received from the V2X CF or PCF) and potentially other factors such as load. The RAN may return the applied range to the AS layer, which forwards the information to the higher layer (i.e. V2X layer) and up to V2X application.

Platoon splitting and merging are described herein. A V2X AS may decide to split a platoon for various reasons. For example, a platoon may be split when the platoon is becoming too big (i.e. too many members), thereby requiring a very large range. The platoon may be split when some devices may go to different final destinations although a portion of the route is the same (i.e. the whole group may move together for some time and then the group is split when specific location is reached). The platoon may be split for temporary split and merge, (i.e. sub-groups are expected to eventually leave the main group and potentially merging back). The platoon may be split due to hierarchical leadership roles: one group leader and many sub-groups leaders. For example, a group of trucks of different formats is subdivided into two groups. Each group may be configured to stop at a gas station. However, the configuration is different for each group. Specifically, trucks with bigger gas tanks stop later while the trucks with smaller gas tanks stop sooner and more often. Trucks may merge back again somewhere on the route after fueling is done.

Splitting may be done by sending a new configuration to platoon members. A device may need to be selected as the platoon leader for the new platoon. Devices selected to be in this new platoon may be configured with the new group ID. A validity time may be associated with this new configuration to make sure that all members apply the new configuration at the same time.

The former platoon, which is now smaller, may be reconfigured to, for example, adjust the maximum number of members. The platoon leader may recalculate the required coverage/range once multiple devices have left the group and then reconfigure the AS layer and group members.

Local decision handled by a platoon leader is described herein. The platoon leader may be configured with a certain level of autonomy. For example, it may be configured to wait for configuration from the V2X CF (or PCF) or V2X AS and then apply and/or forward it to platoon members. Alternatively or additionally, the platoon leader may be configured with local decision authority. This means that the platoon leader may be allowed to take local decisions to be applied immediately to the platoon. The V2X AS may be informed of the decisions and triggering events and may eventually revert or confirm the local decisions.

Authority for local decisions may be allowed to quickly react to certain conditions.

The platoon leader may also be configured to decide or allocate the lead role to another device based on time as a leader, capabilities, load, or the like as the platoon size changes.

For example, when a group is becoming too large, the platoon leader that is allowed to take local decisions may decide to increase the range while waiting for the V2X AS decision. The platoon leader may configure its AS layer with the new range value and advertise this new value to the platoon members for their own AS layer configuration. The V2X AS is also informed of this new configuration.

In order to achieve this functionality, the platoon leader may be configured with multiple transmission profiles, for example, one profile to be used now and the other profile for increased or decreased number of members. The platoon leader may keep track of the number of members and apply a local decision, for example, when the maximum number of members is reached.

Later, the V2X AS may decide to maintain the leader's decision, further increasing the range or split the platoon as examples. Specifically, the V2X AS may decide to split a platoon as described above. This may be done by sending a new configuration to the platoon members. A device needs to be selected as the leader for a new platoon. The device selected to be a leader in the new platoon may be configured with the new group ID. A validity time may be associated with this new configuration to make sure that all members will apply the new configuration at the same time.

Claim 1:
A method for use in a wireless transmit/receive unit, WTRU, the method comprising:
receiving, from a vehicle to everything application server, V2X AS, a vehicle to everything, V2X, provisioning message that includes a plurality of V2X group-related parameters indicating a role of the WTRU in a V2X group, a size of the V2X group, and a V2X group identifier associated with the V2X group, wherein the V2X group comprises a plurality of WTRUs for group-based PC5 communication; and
transmitting a transmission range associated with the plurality of V2X group-related parameters to the plurality of WTRUs to enable the group-based PC5 communication, wherein the indication of the role of the WTRU in the V2X group indicates that the WTRU is a group leader, and the transmission range associated with the V2X group-related parameters is determined based on mapping information received from a V2X control function, V2X CF.