Methods, apparatuses, and systems for supporting vehicle-to-pedestrian (v2p) communications using vehicle-to-everything (v2x) enhancements

Abstract

V2X enhancements to support V2P communications are disclosed. In particular, vehicle-to-pedestrian communications are provided. The disclosure provides methods and apparatus for operation of a direct link with a peer wireless transmit / receive unit (WTRU) using a first key identifier of a root key by an initiating WTRU. In one embodiment, a method includes sending, by an initiating WTRU to a peer WTRU, a release request message to release a direct link with the peer WTRU, the release request message including information indicating first security information associated with a second key identifier of the root key. The method further includes receiving, by the initiating WTRU from the peer WTRU, a response to the release request message, the response including second security information associated with the second key identifier of the root key. The method further includes determining, by the initiating WTRU, the second key identifier of the root key using the first security information and the second security information; and sending, by the initiating WTRU to the peer WTRU, a message including information indicating the second key identifier of the root key.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 976,174, filed February 13, 2020, and U.S. Provisional Patent Application Serial No. 63 / 008,253, filed April 10, 2020, the contents of each of which are incorporated herein by reference. Technical Field

[0003] Embodiments disclosed herein relate generally to wireless communications, and, for example, to methods, apparatus, and systems for supporting V2P communications using V2X enhancements. Background Art

[0004] A V2X communication architecture has been developed for wireless communication systems, including those using the Evolved Packet Core (EPC). V2X communication can include one or more of vehicle-to-vehicle (V2V) communication, vehicle-to-person (V2P) communication, vehicle-to-infrastructure (V2I) communication, and vehicle-to-network (V2N) communication.

[0005] New Radio (NR) V2X may support two modes of operation, Mode 1 and Mode 2. Mode 1 is based on Long Term Evolution (LTE) V2X Mode 3 operation. For example, the network may schedule sidelink (SL) resources via downlink (DL) downlink control information (DCI) signaling, and the wireless transmit / receive unit (WTRU) may apply the received resource reservation to the SL transmission. Mode 2 may use LTE Mode 4 as a baseline for semi-persistent scheduling. In Mode 4, the WTRU may autonomously select and reserve resources from a configured resource pool. In one example, the configured resource pool may be a pre-configured resource pool. Autonomous resource reservation may be based on WTRU sensing to identify available candidate resources. Summary of the Invention

[0006] The present invention discloses V2X enhancements for supporting V2P communications. Specifically, vehicle-to-pedestrian communications and security are provided. The present invention provides methods and apparatus for an initiating wireless transmit / receive unit (WTRU) to implement operations of a direct link with a peer WTRU using a first key identifier of a root key. In one embodiment, a method includes sending a release request message by an initiating WTRU to a peer WTRU to release the direct link with the peer WTRU, the release request message including information indicating first security information associated with a second key identifier of the root key. The method also includes receiving, by the initiating WTRU, a response to the release request message from the peer WTRU, the response including second security information associated with the second key identifier of the root key. The method also includes determining, by the initiating WTRU, the second key identifier of the root key using the first security information and the second security information; and sending, by the initiating WTRU, a message including information indicating the second key identifier of the root key to the peer WTRU. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more detailed understanding may be obtained from the following description given by way of example with reference to the accompanying drawings in which like reference numerals indicate like elements and in which:

[0008] Figure 1A is a system diagram illustrating an exemplary communication system in which one or more disclosed embodiments may be implemented;

[0009] Figure 1B It is shown that according to one embodiment, Figure 1A A system diagram of an exemplary wireless transmit / receive unit (WTRU) for use within the illustrated communication system;

[0010] Figure 1C It is shown that according to one embodiment, Figure 1A a system diagram illustrating an exemplary radio access network (RAN) and an exemplary core network (CN) for use within the illustrated communication system;

[0011] Figure 1D It is shown that according to one embodiment, Figure 1A A system diagram of another exemplary RAN and another exemplary CN used within the illustrated communication system;

[0012] Figure 2 Shown is the non-roaming 5G system architecture for PC5 and Uu-based V2X communications;

[0013] Figure 3 shows an example of a WTRU establishing a dormant PC5 link according to the procedures described herein;

[0014] Figure 4shows the safety procedures when entering the normal link state;

[0015] Figure 5 is a flow chart illustrating a representative method performed by an initiating wireless WTRU for a direct link with a peer WTRU;

[0016] Figure 6 is a flow chart illustrating another representative method performed by an initiating wireless WTRU for a direct link with a peer WTRU;

[0017] Figure 7 is a flow chart illustrating another representative method performed by an initiating wireless WTRU for a direct link with a peer WTRU;

[0018] Figure 8 is a diagram illustrating security procedures implemented by an initiating wireless WTRU for a direct link with a peer WTRU;

[0019] Figure 9 is a flow chart illustrating a representative method implemented by an initiating wireless WTRU for a direct link with a peer WTRU using a first key identifier of a root key; and

[0020] Figure 10 is a flow chart illustrating another representative method implemented by an initiating wireless WTRU for a direct link with a peer WTRU using a first key identifier of a root key. DETAILED DESCRIPTION

[0021] Figure 1A is a schematic diagram illustrating an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0022] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a station (STA)) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, 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 device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated process chain environments), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0023] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a NodeB, an evolved NodeB (eNB), a Home NodeB, a Home evolved NodeB, a next generation NodeB such as a gNodeB (gNB), a New Radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0024] Base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage to a specific geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, one for each sector of the cell. In one embodiment, base station 114a may employ multiple-input, multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0025] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0026] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0027] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0028] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access and may establish the air interface 116 using NR.

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement both LTE radio access and NR radio access, for example, using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0030] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), GSM Enhanced Data rates for Evolution (EDGE), GSM EDGE (GERAN), etc.

[0031] Figure 1AThe base station 114b in the may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a microcell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to the Internet 110. Thus, base station 114b may not need to access the Internet 110 via CN 106.

[0032] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Data may have different quality of service (QoS) requirements, such as different throughput requirements, delay requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform advanced security functions, such as user authentication. Although not described in detail in the text, the CN 106 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Figure 1A Although not shown in the figures, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0033] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) from the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0034] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0035] Figure 1B is a system diagram illustrating an exemplary WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0036] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0037] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It should be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0038] Although the transmit / receive element 122 is Figure 1B Although depicted as a single element in FIG1 , the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0039] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0040] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Furthermore, the processor 118 may access information from and store data in any suitable type of memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, or the like. In other embodiments, the processor 118 may access information from and store data in memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0041] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0042] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0043] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, Module, frequency modulation (FM) radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device, activity tracker, etc. Peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor, altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor, humidity sensor, etc.

[0044] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0045] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As described above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0046] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0047] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0048] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0049] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0050] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNode-B handovers, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0051] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0052] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0053] Even though the WTRU Figures 1A to 1D Although described as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may (eg, temporarily or permanently) employ a wired communications interface with a communications network.

[0054] In a representative embodiment, the other network 112 may be a WLAN.

[0055] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or out of the BSS. Traffic originating from outside the BSS and destined for a STA can reach the AP and be delivered to the STA. Traffic originating from a STA and destined for a destination outside the BSS can be sent to the AP for delivery to the destination. Traffic between STAs within a BSS can be sent through the AP, for example, where a source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within a BSS can be considered and / or referred to as point-to-point traffic. Point-to-point traffic can be sent between a source and destination STA (e.g., directly between them) using direct link setup (DLS). In certain representative embodiments, the DLS can use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

[0056] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may transmit beacons on a fixed channel, such as the primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. With CSMA / CA, STAs (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected by a particular STA and / or determined to be busy, the particular STA may back off. One STA (e.g., only one station) may transmit in a given BSS at any given time.

[0057] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a primary 20 MHz channel combined with adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0058] Very high throughput (VHT) STAs can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 40 MHz and / or 80 MHz channels can be formed by combining consecutive 20 MHz channels. A 160 MHz channel can be formed by combining eight consecutive 20 MHz channels, or by combining two non-contiguous 80 MHz channels (this may be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, the data can pass through a segment parser that can separate the data into two streams. Each stream can be individually processed using an inverse fast Fourier transform (IFFT) and time domain processing. These streams can be mapped to two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration can be reversed, and the combined data can be sent to the medium access control (MAC).

[0059] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0060] WLAN systems that support multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah include a channel that can be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (that supports the minimum bandwidth operating mode) from among all STAs operating in the BSS. In the example of 802.11ah, for a STA (e.g., an MTC-type device) that supports (e.g., only supports) 1 MHz mode, the primary channel may be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, because a STA (that only supports 1 MHz operating mode) is transmitting to the AP, the entire available frequency band may be considered busy even if most of the available frequency band remains idle.

[0061] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0062] Figure 1D 1 is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0063] The RAN 104 may include gNBs 180a, 180b, and 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, and 180c. Thus, the gNB 180a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, and 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, and 180c may implement coordinated multi-point (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0064] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable parameter sets. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths).

[0065] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate or connect with the gNBs 180a, 180b, 180c while also communicating or connecting with other RANs, such as the eNode-Bs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may serve as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0066] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR, and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0067] Figure 1D The illustrated CN 106 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 data networks (DNs) 185a, 185b. While the aforementioned elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0068] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, managing registration areas, terminating non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRUs 102a, 102b, 102c based on the type of services used by the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on Ultra Reliable Low Latency (URLLC) access, services relying on enhanced Mobile Broadband (eMBB) access, services for MTC access, etc. The AMFs 182 a and 182 b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0069] The SMF 183a, 183b may connect to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also connect to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notifications, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0070] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N3 interface. These gNBs may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184a, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, and the like.

[0071] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. Additionally, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may connect to the local DNs 185a, 185b through the UPFs 184a, 184b via the N3 interface to the UPFs 184a, 184b and the N6 interface between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0072] Given that Figures 1A to 1D as well as Figures 1A to 1D

[0015] As described herein, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more emulated devices (not shown): the WTRUs 102a-102d, the base stations 114a-114b, the eNodeBs 160a-160c, the MME 162, the SGW 164, the PGW 166, the gNBs 180a-180c, the AMFs 182a-182b, the UPFs 184a-184b, the SMFs 183a-183b, the DNs 185a-185b, and / or any other devices described herein. An emulated device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, an emulated device may be used to test other devices and / or simulate network and / or WTRU functions.

[0073] The emulation device may be designed to implement one or more tests of other devices in a lab environment and / or in a carrier network environment. For example, the one or more emulation devices may perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0074] The one or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test lab and / or a non-deployed (e.g., testing) wired and / or wireless communication network to enable testing of one or more components. The one or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which can include one or more antennas) can be used by the simulation device to transmit and / or receive data.

[0075] As used herein, the term WTRU is also used as a general term to identify a device in which one or more V2X applications are running. A V2X Application Server (V2X AS) may be located in the network and may interface with V2X applications installed on the WTRU. A V2X Control Function (CF) may handle the authorization and provisioning of V2X devices. This may include, for example, configuring V2X policies and / or parameters for the WTRU. V2XCF functions may be handled at the PCF. V2X WTRU-to-WTRU communications may be based on two modes of operation: over the Uu reference point and over the PC5 reference point.

[0076] V2X communication over the PC5 reference point may be a type of ProSe communication. One-to-one ProSe direct communication may be achieved by establishing a secure Layer 2 link over PC5 between two WTRUs, which is often referred to as unicast communication (e.g., the communication may involve two peers).

[0077] Figure 2 The non-roaming 5G system architecture for V2X communication based on PC5 and Uu is shown. Figure 2As shown, some examples of V2X WTRUs 102 may be vehicle WTRUs (WTRU 102b and WTRU 102c) or pedestrian WTRUs (WTRU 102a). V2X communication may also occur between two pedestrian WTRUs. V2X communication may also occur between a mobile WTRU 102a, 102b, and / or 102c and a fixed / stationary WTRU 102c (e.g., a roadside unit (RSU) or other fixed equipment). The communication between WTRU 102b or 102c (vehicle) and WTRU 102a (pedestrian) may be referred to as V2P communication, while the communication between WTRU 102b (vehicle) and WTRU 102c (vehicle) may be referred to as V2V communication. Figure 2 As shown, both V2V and V2P communications may occur via the PC5 interface, and characteristics such as message frequency, power, etc. of V2V communications may differ from those of V2P type communications.

[0078] refer to Figure 2The V2X communication network 200 may include a DN 185 executing / running one or more V2X applications, a first vehicle (e.g., vehicle WTRU 102b) executing / running one or more V2X applications, a second vehicle (e.g., vehicle WTRU 102c) executing / running one or more V2X applications, a pedestrian (e.g., pedestrian / V2P WTRU 102a) executing / running one or more V2X applications, a stationary / fixed device (e.g., stationary WTRU 102d) executing / running one or more V2X applications, an NG-RAN 104, and a core network (CN) 106. The CN 106 may include an AMF 182, an SMF 183, an UPF 184, a DN 185, a unified data management (UDM) 186 that may be paired with a user data repository (UDR, not shown), a policy and control function (PCF) 187, a network exposure function (NEF) 188, and / or an application function (AF) 189. WTRUs (e.g., vehicle WTRU 102b, vehicle WTRU 102c, pedestrian WTRU 102a, and / or stationary WTRU 102d) may communicate using the PC5 interface (e.g., PC5 communications). V2X applications executing on the WTRUs (e.g., vehicle WTRU 102b, vehicle WTRU 102c, pedestrian WTRU 102a, and / or stationary WTRU 102d) may communicate using the V5 interface. The vehicle WTRU 102b and the stationary WTRU 102d may communicate with the NG-RAN 104 using the Uu interface. The NG-RAN 104 may communicate with the AMF 182 of the CN 106 using the N2 interface and with the UPF 184 of the CN 106 using the N3 interface. The DN 185 may be located within the CN 106 or interface with the CN 104 using the N6 interface. The UPF 184 and the SMF may communicate using the N4 interface.

[0079] A V2P WTRU 102a supporting a V2P application sends a message that includes or contains V2P application information. The V2P application information may be sent by a WTRU supporting a V2X application in a vehicle, such as a warning to a pedestrian, or by a WTRU supporting a V2X application associated with a vulnerable road user, such as a warning to a vehicle. 3GPP transmissions of messages that include / contain V2P application information may include direct transmissions between WTRUs 102 and / or transmissions between WTRUs via infrastructure supporting V2X communications (e.g., roadside units (RSUs), application servers, etc.), for example, due to limited direct communication range. As described herein and based on Figure 2In the architecture described above, V2X may support both vehicle-type WTRUs 102b / 102c and pedestrian-type WTRUs 102a. V2X may also support other specific functions for pedestrian-type WTRUs 102a carried by pedestrian users, cyclists, etc. Special resource selection mechanisms (i.e., partial sensing or random selection) for pedestrian-type WTRUs 102a may be used in PC5 communications. Generally, there is no optimization for pedestrian-type WTRUs 102a, which have power and computational limitations compared to vehicle-type WTRUs 102b / 102c. It is desirable to support V2X usage for vulnerable road users (VRUs) and thereby provide enhancements in related areas (e.g., energy savings, etc.).

[0080] Privacy for PC5 unicast link identifiers may also be included. The link identifier update procedure may provide privacy for identifiers used in PC5 unicast links. New identifiers may be exchanged using a three-way exchange of protected messages. The new identifiers may then be used for the connection. The exchanged identifiers include a new L2 ID for the peer WTRU 102 and a new KD session ID. The peer WTRUs 102 may periodically exchange new identifiers to prevent linkability and traceability attacks, as these identifiers are sent in the clear with every transmission (L2 frame, PDCP packet).

[0081] The KD session ID identifies the security context being used by the peer WTRU 102 to protect communications on the PC5 unicast link. The session key KD session may be derived from the root key KD established by the peer WTRU 102 during their mutual authentication. The KD ID identifies the root key KD and may be sent in plain text in a Direct Communication Request (DCR) message during link establishment (e.g., when the WTRU 102a reestablishes a connection with an already authenticated peer WTRU 102b).

[0082] As described herein, the V2X procedures described are largely defined for V2V communications. These procedures are applicable to V2P communications and may be optimized for pedestrian WTRUs due to the different characteristics of such devices. A WTRU 102a supporting V2P applications for pedestrian use may, for example, have a lower battery capacity, limited radio range (e.g., due to antenna design), and therefore may not be able to send messages with the same periodicity as a WTRU supporting V2V applications and / or may not be able to receive messages. The WTRU 102 may be used for safety purposes, such as exchanging safety messages and information, such as information about the environment, with other WTRUs 102b, 102c, 102d (e.g., vehicles, RSUs, etc.). For vehicles or fixed RSUs, power may not be an issue, however, for smartphones, power may be limited and may need to be managed efficiently. The present disclosure enhances the 5G system to support the uses, requirements, and / or characteristics of V2P communications.

[0083] Enhanced privacy may be provided for PC5 unicast communications. The link identifier update procedure may enable peer WTRUs to periodically change the L2 ID and / or KD session ID to maintain the privacy of these identifiers throughout the lifetime of a given connection. Unlike the identifiers described above, the root key KD and its identifier KD ID may be reused across multiple subsequent connections (e.g., when a peer WTRU disconnects and subsequently reconnects). An attacker may be able to use the KD ID sent in clear text in a DCR message to link a given connection and subsequent reconnections between these peer WTRUs 102.

[0084] Establishing the KD ID during the link identifier update procedure may not be sufficient to fully mitigate the threat because the peer WTRUs 102 may disconnect and subsequently reconnect before any link identifier update procedure is completed. Using the link identifier update procedure to perform a change of the KD ID may introduce unnecessary overhead because such a change may be used / required to be performed once before a new connection between the peer WTRUs 102 is reestablished, and because the KD ID may not be sent as clear text with every transmission, as is the case with the KD session ID and L2 ID.

[0085] In certain representative embodiments, this procedure may be implemented, for example, to enhance support (e.g., in an efficient manner) for V2X operations of the WTRU 102 for pedestrian WTRUs 102a and / or vulnerable road users. Pedestrian users and their smartphones (which may be examples of V2P WTRUs 102a) may participate in V2X communications or potentially support safety. When the WTRU 102 is in a specific location (e.g., inside a building and / or not required to participate in V2X communications), certain V2X features of the WTRU 102 may be dormant and / or used sparingly. V2X communications of the V2P WTRU 102a or WTRU 102 to support V2P applications may be enabled using "state change triggers" used by the WTRU, for example, to effectively adapt its behavior to the requirements of V2P communications, as already described. For example, an application client running on the WTRU, such as a V2P application, may have the ability to derive and / or obtain the WTRU's application characteristics or precise location (e.g., whether the WTRU 102 is located indoors or outdoors), speed, and direction. The WTRU 102 may provide multiple profiles for each application ID. The WTRU 102 may establish a PC5 unicast link indicating its desired PC5 link state. If the link is established in a dormant PC5 state, the WTRU 102 may establish a limited connectivity PC5 link. A limited connectivity PC5 link may include lower QoS, very low keep-alive frequency (e.g., keep-alive messages), etc. The WTRU 102 may receive triggers from the application layer based on, for example, the WTRU's precise location. The WTRU 102 may adjust its behavior based on its context information, including the location, current state, and / or configuration profile (e.g., profile information) of a particular application, such as changing from a dormant state to a normal PC5 state (e.g., from a limited connectivity PC5 link to a full PC5 connectivity link). The WTRU 102 may notify its peer WTRU 102 of its state modification status by sending a PC5 link modification request with its new state (e.g., transitioning to a full connectivity (normal) PC5 link).

[0086] During registration, the WTRU 102 may send one or more pedestrian capabilities and may receive profile and / or configuration information. When the V2P WTRU 102a performs a registration procedure with the network, the WTRU 102 may include its capabilities for performing V2P communications in the registration message. Upon receiving the registration message, the AMF 182 may check the WTRU's subscription to the UDM / UDR 186. If the WTRU 102 is authorized to perform V2P communications based on the subscription, the AMF 182 may also retrieve configuration parameters from the PCF 187. The V2P configuration parameters are returned by the AMF 182 to the pedestrian WTRU 102a in a Registration Accept message. V2P configuration parameters may include one or more of the following: applications or application IDs authorized for V2P communication; profile information that may trigger a state change (e.g., the profile / profile information may be based on multiple context parameters, such as: location, altitude, direction, speed, battery level, PC5 link status; the location value may be, for example: pedestrian outside, pedestrian inside, fast moving; the battery level value may be, for example: full, half, low; and the link status may be, for example, normal, dormant / restricted). For example, a profile with link status / battery level for each location may include pedestrian outside, full / half battery to normal PC5 connection for V2P; pedestrian outside, low battery to dormant PC5 for V2P; pedestrian inside (office, shopping mall), battery level to dormant PC5 for V2P; fast moving (e.g., in a car), full / half battery to normal PC5 connection; pedestrian outside to normal PC5 connection; value of the keep-alive timer during dormant PC5 state; value of the timer to maintain dormant PC5 state or the inactivity timer to enter dormant PC5 state; bit rate of dormant / restricted PC5 connection, such as AMBR; configurable certificates or keys in case of establishing a PC5 link in dormant / restricted state; and / or the maximum number of PC5 connections when in dormant / restricted state.

[0087] The pedestrian WTRU 102a may use the received configuration parameters in conjunction with information received from the application layer. The application layer may determine whether the pedestrian WTRU 102a is indoors or outdoors and / or at a specific location. This information may be passed down to the V2X or PC5 layer. The PC5 layer may trigger (e.g., then trigger) state change behavior based on input from the application and / or the received configuration parameters.

[0088] During the registration procedure, the AMF 182 may notify the RAN (ng-NB) via N2 messaging that the pedestrian WTRU 102a is authorized for V2P communication. Applications on the pedestrian WTRU 102a may determine / calculate the location (e.g., whether the pedestrian WTRU 102a is indoors or outdoors, etc.). The network may decide / determine to change and update V2P WTRU configuration parameters. The pedestrian WTRU 102a may receive the new / updated parameters via the WTRU configuration procedure.

[0089] The WTRU 102 may establish unicast PC5 communications. When a pedestrian WTRU 102a (sometimes referred to as a V2P WTRU) establishes unicast PC5 communications with a peer WTRU (e.g., another pedestrian WTRU 102a, a vehicle WTRU 102b / 102c, or an RSU (e.g., a stationary WTRU 102d, etc.)), the V2P WTRU 102a may indicate that the PC5 connection / link is for V2P communication. Such an indication may be in the form of one or more pedestrian capability IEs and / or explicit pedestrian information in the connection type information element and / or application ID of the V2P application. The V2P WTRU 102a may indicate the "link state" (e.g., "required link state") of the PC5 unicast link (dormant or normal) and / or may indicate its battery level. The WTRU 102 may send these new information elements in a Direct Communication Request (DCR) message. Unicast link establishment may be completed when the peer WTRU sends a Direct Communication Accept (DCA) message. Based on the state information (e.g., "desired state" information) exchanged during the link establishment procedure, the PC5 link may be in a dormant state or a normal state. If the link is established in the normal state, the peer WTRU 102 may operate / behave according to normal PC5 unicast operation.

[0090] A WTRU 102 that has a normal unicast link with a peer WTRU 102 may use the battery level of its peer WTRU to determine whether or should establish more PC5 links with other surrounding WTRUs 102. For example, if the battery level of the peer WTRU is advertised as medium (e.g., intermediate) and a number of V2P messages (e.g., a threshold number of messages) have been exchanged, then it is expected that the existing PC5 link state may change from a normal state to a dormant state. A WTRU 102 that has a dormant unicast link with a peer WTRU 102 and a low battery level may establish a minimum number of PC5 links for a particular application, as indicated in the profile / profile information (e.g., set based on rules according to the profile), e.g., not exceeding a maximum number of PC5 links when in a dormant / restricted state, e.g., to conserve power.

[0091] Figure 3is a diagram illustrating an example procedure for a WTRU (eg, WTRU 102a) to establish a dormant PC5 link according to the procedures described herein.

[0092] refer to Figure 3 The procedure 300 may include, at 310, the WTRU 102a sending a message (e.g., a DCR message or another type of direct message) to the peer WTRU 102b. At 320, the peer WTRU 102b may send a message (e.g., a Direct Communication Accept (DCA) message or another type of direct message) to the WTRU 102a. For example, the message from the WTRU 102a may include information indicating that the requested or desired state is a first link state (e.g., a dormant link state or a normal link state), and in response, the message from the WTRU 102b may include information indicating acceptance of the first link state (e.g., the dormant link state or the normal link state).

[0093] In certain representative embodiments, during PC5 operation, the normal PC5 link state may be changed to a dormant link state. Changing states is further described herein.

[0094] When establishing a unicast link in the "dormant" or restricted PC5 state, the behavior of the peer WTRU may differ compared to the "normal" state as follows. A requesting WTRU (e.g., WTRU 102a) may request a PC5 link with a default value of the lowest QoS value (PQI), or a responding WTRU (e.g., WTRU 102b) may respond with a low QoS value. A PC5-S channel may be established, and the establishment of a PC5-U or data channel may be delayed until a change of state is triggered. Information between the WTRU V2X / PC5 layer and the access layer may be exchanged during link establishment for the AS layer to provide (e.g., only) resources for the PC5-S channel.

[0095] If a WTRU (e.g., WTRU 102a) has some data to send (possibly a small amount of data), WTRU 102a may use the PC5-S channel to exchange data with a peer WTRU (e.g., WTRU 102b). A WTRU (e.g., WTRU 102a) may use a low-rate PC5 AMBR (e.g., received in the V2P configuration information) to limit / reduce the data rate used for transmission in this dormant link state (e.g., via the PC5-S channel). The WTRU (e.g., WTRU 102a) may send an indication to the RAN 104 that the WTRU's 102a current PC5 state is "dormant" or limited. The RAN 104 may use this information for resource allocation to the WTRU 102a in this state.

[0096] A privacy timer may be used to update a link identifier that may be ignored by a WTRU (e.g., WTRU 102a). For example, a link identifier update procedure may not be performed. A WTRU (e.g., WTRU 102a) may ignore triggers from upper layers (applications) to update a link identifier (L2 ID, application ID, IP address / prefix, etc.).

[0097] If the unicast link is no longer used / needed, the WTRU (e.g., WTRU 102a) may implicitly disconnect the PC5 unicast link, the WTRU (e.g., WTRU 102a) may indicate the link disconnection in the next keep-alive message it sends to the peer WTRU (e.g., WTRU 102b), or the WTRU 102a may send a link release request without waiting for a response from the peer WTRU 102b.

[0098] A WTRU (e.g., WTRU 102a) may request that security establishment be delayed during the PC5 link establishment procedure. In this case, pre-configured security credentials (e.g., one or more certificates and / or one or more security keys) may be used. An indication to skip the security procedure may be sent by the requesting WTRU (e.g., WTRU 102a) in a DCR message, or by the responding WTRU (e.g., WTRU 102b) in a DCA message with such an indication and skipping the security procedure.

[0099] IP address assignment or Dynamic Host Configuration Protocol (DHCP) procedures after link establishment may be delayed until the WTRU returns to (eg, re-enters) the normal PC5 state.

[0100] A WTRU (e.g., WTRU 102a) may limit / reduce the number of its PC5 connections as indicated in the profile / profile information. For example, it may drop inactive PC5 links or release some of the multiple PC5 links if they have different peers and are for the same application ID.

[0101] Figure 4 The security procedure when entering the normal link state is shown. In the case where the state transitions from "dormant / restricted" to "normal" and the security procedure and / or IP address allocation procedure for the PC5 link were skipped during link establishment, the security procedure and / or IP address / prefix allocation procedure are triggered at this time, for example, after the link modification procedure (first embodiment) or during the link modification procedure (second embodiment).

[0102] The security parameters sent in the initial Direct Communication Request message may be saved on the T-WTRU / S-WTRU (T-UE / S-UE) and reused to establish the security context in the first embodiment. Otherwise, the security parameters may be sent in the Link Modification Request message in the second embodiment.

[0103] refer to Figure 4 , the security procedure 400 may include, at 410, a WTRU (e.g., WTRU 102a) and WTRU 102b having established a PC5 unicast link in a dormant link state. At 420, in a first alternative, WTRU 102a may send a request to WTRU 102b (e.g., a link modification request or another type of request to WTRU 102b). The request may include information indicating the changed state (e.g., may include a state change indication and / or may include a new state (e.g., indicating that the new state is "normal")). At 430, WTRU 102b may send an accept message (e.g., a link modification accept message) to WTRU 102a. The accept message may include information indicating the new accepted state (e.g., "normal"). At 440, WTRU 102a may send a command message (e.g., a direct security mode command message) to WTRU 102b. At 450, WTRU 102b may send a completion message (e.g., a direct security mode complete message) to WTRU 102a. In a second alternative, at 460, the WTRU 102a may send a request to the WTRU 102b (e.g., a link modification request or another type of request to the WTRU 102b). The request may include information indicating the changed state (e.g., may include a state change indication and / or may include the new state (e.g., indicating that the new state is "normal"). At 470, the WTRU 102b may send a command message (e.g., a direct security mode command message) to the WTRU 102a. At 480, the WTRU 102b may send a completion message (e.g., a direct security mode complete message) to the WTRU 102a. At 490, the WTRU 102b may send an accept message (e.g., a link modification accept message) to the WTRU 102a. The accept message may include information indicating the new accepted state (e.g., "normal").

[0104] The security procedure 400 may enable transitions between states (e.g., dormant link state and normal link state). Based on information received from the application layer and corresponding configuration information, the WTRU (e.g., WTRU 102a) may change the PC5 link state (from dormant to normal PC5, and vice versa). For example, a user moving from an indoor building to an outdoor street may be a trigger for the WTRU (e.g., WTRU 102a) to change a dormant / restricted PC5 link to an active (e.g., full) PC5 link. The opposite example (moving from indoors to outdoors) may trigger an active (e.g., full) PC5 link to enter a dormant / restricted / inactive state.

[0105] A state change timer (e.g., an inactivity timer received in the V2P configuration information) may trigger a state change from the normal PC5 state to the dormant / restricted / inactive PC5 state. The inactivity timer may start when a WTRU (e.g., WTRU 102a) receives a user plane packet on the PC5 channel / link and may be reset when a new packet is received. Upon expiration of the inactivity timer, the WTRU (e.g., WTRU 102a) may transition the link from a normal PC5 link to a dormant PC5 link by initiating a link modification procedure.

[0106] The battery charge level may also trigger a change in link state. For example, a change from a half-charged state to a low-charged state may trigger a WTRU (e.g., WTRU 102a) to change an active PC5 link to a dormant / restricted PC5 link. This may also occur when the WTRU battery is fully charged. In this case, the battery state may change from low to half to full, thereby triggering a WTRU (e.g., WTRU 102a) to change a dormant / restricted PC5 link to an active PC5 link.

[0107] In certain representative embodiments, a WTRU (e.g., WTRU 102a) may use a link modification procedure or similar PC5-S message to indicate a change of state to a peer WTRU (e.g., WTRU 102b). New information may be added, for example, to a link modification request message to notify the peer WTRU (e.g., WTRU 102b) of the state change (e.g., a state change indication) and / or the WTRU (e.g., WTRU 102a) may include the new state in a link modification request message to the peer (new link state = dormant / restricted or normal). Accordingly, the peer WTRU (e.g., WTRU 102b) may acknowledge the new state and, accordingly, change its state for the PC5 link. The peer WTRU (e.g., WTRU 102b) may then send a PC5 message (e.g., link modification accept) to indicate its new state to the other WTRU 102a. In the event that the peer WTRU (e.g., WTRU 102b) is unable to change the link state, WTRU 102b may send back a Link Modification Reject message with a cause value indicating the reason for rejecting the request and may include the current state (which has not changed, e.g., dormant / restricted link state). WTRU 102a and WTRU 102b may accordingly send information to the access layer so that the AS layer adjusts the resources provided for the PC5-S channel / link and possibly for the PC5-U channel / link (if the modification is accepted by the peer WTRU (e.g., WTRU 102b). WTRU (e.g., WTRU 102a) behavior corresponding to the new state (active / normal link state or dormant / restricted link state) as previously described may then ensue.

[0108] Figure 5 is a flow chart illustrating a representative method implemented by an initiating WTRU for establishing a direct link with a peer WTRU using a first key identifier (eg, for unicast communication between the WTRU and the other WTRU).

[0109] refer to Figure 5 The representative method 500 may include, at block 510, sending, by the initiating WTRU 102a, a link request message to the peer WTRU 102b for a direct link to the peer WTRU 102b and including information indicating a requested link state, the requested link state being a dormant state associated with a limited connectivity PC5 link. At block 520, the initiating WTRU 102a may receive a response to the connection request message from the peer WTRU 102b, the response including information indicating acceptance of the dormant state of the initiating WTRU 102a. At block 530, the initiating WTRU 102a may configure the initiating WTRU 102a for direct communication over the limited connectivity PC5 link.

[0110] In certain representative embodiments, the link request message may be a direct communication request (DCR) message, and the response to the link request message may be a direct communication accept (DCA) message.

[0111] In certain representative embodiments, limited connectivity PC5 links may use only control plane (C-plane) resources.

[0112] In certain representative embodiments, the initiating WTRU 102a may send information to a network entity indicating that direct communication with the peer WTRU 102b is over a limited connectivity PC5 link.

[0113] In certain representative embodiments, direct communication over the PC5 link may be used for vehicle-to-pedestrian (V2P) communication.

[0114] In certain representative embodiments, the initiating WTRU 102a may be a pedestrian WTRU.

[0115] Figure 6 is a flow chart illustrating another representative method implemented by an initiating WTRU for a direct link with a peer WTRU using a first key identifier (eg, for unicast communication between the WTRU and other WTRUs).

[0116] refer to Figure 6 The representative method 600 may include, at block 610, establishing, by the initiating WTRU 102a, a direct link in a first link state with the peer WTRU 102b based on the profile information. The first link state may be a dormant link state associated with a limited connectivity PC5 link, while the second link state may be a normal link state associated with a full connectivity PC5 link. At block 620, the initiating WTRU 102a may receive a trigger from the application layer by lower layers of the initiating WTRU 102a. At block 630, the initiating WTRU 102a may modify the link state associated with the direct link to a normal link state.

[0117] In certain representative embodiments, the initiating WTRU 102a may send a link modification request message to the peer WTRU 102 including information indicating the modified link state.

[0118] In certain representative embodiments, establishment of a direct link in a first link state may include sending, by the initiating WTRU 102a, to the peer WTRU 102b, a link request message including information indicating the first link state; and may include receiving, by the initiating WTRU 102a, from the peer WTRU 102b, a response to the link request message including information indicating acceptance of the first link state.

[0119] In certain representative embodiments, limited connectivity PC5 links may include connections / links that use only control plane (C-plane) resources, while full connectivity PC5 links may include connections / links that use both user plane (U-plane) and C-plane resources.

[0120] In certain representative embodiments, the initiating WTRU 102a may be configured such that the quality of service (QoS) level associated with a limited connectivity PC5 link is lower than the QoS level associated with a full connectivity PC5 link.

[0121] In certain representative embodiments, the initiating WTRU 102a may be configured such that the frequency of keep-alive messages over a limited connectivity PC5 link is less than the frequency of keep-alive messages over a full connectivity PC5 link.

[0122] In certain representative embodiments, under the condition that the direct link is associated with a dormant link state, the WTRU 102a may wait until the direct link is associated with a normal link state to perform a security establishment procedure.

[0123] In certain representative embodiments, the WTRU 102a may trigger a security establishment procedure when modifying the link state associated with the direct link to a normal link state.

[0124] In certain representative embodiments, the initiating WTRU 102a may send information to a network entity (e.g., the RAN 104 or gNB 180) indicating that the direct link is associated with the first link state.

[0125] In certain representative embodiments, the direct link on PC 5 may be used for vehicle-to-pedestrian (V2P) communications.

[0126] In certain representative embodiments, the initiating WTRU 102a may be a pedestrian WTRU.

[0127] In certain representative embodiments, the profile information may indicate any of: (1) the battery level of the initiating WTRU 102a; or (2) the maximum value of the PC5 link established by the initiating WTRU 102a.

[0128] In certain representative embodiments, the triggering item may be based on any of the following: (1) the location of the initiating WTRU 102a; (2) the battery level of the initiating WTRU 102a; (3) the battery level of the peer WTRU 102b; (4) determining whether the initiating WTRU 102a is indoors or outdoors; and (5) the current state of the application executing on the initiating WTRU 102a.

[0129] Figure 7is a flow chart illustrating another representative method implemented by an initiating WTRU for a direct link with a peer WTRU using a first key identifier (eg, for unicast communication between the WTRU and other WTRUs).

[0130] refer to Figure 7 The representative method 700 may include, at block 710, establishing, by the initiating WTRU 102a, a direct link with a peer WTRU 102b based on profile information, a first link state, where the first link state may be a normal link state associated with a full connectivity PC5 link, and a second link state may be a dormant link state associated with a limited connectivity PC5 link. At block 720, the initiating WTRU 102a may receive a trigger from the application layer by lower layers of the initiating WTRU 102a. At block 730, the initiating WTRU 102a may modify the link state associated with the direct link to a dormant link state.

[0131] In certain representative embodiments, the initiating WTRU 102a may send a link modification request message to the peer WTRU 102b including information indicating the modified link state.

[0132] In certain representative embodiments, establishment of a direct link in a first link state may include sending, by the initiating WTRU 102a, to the peer WTRU 102b, a link request message including information indicating the first link state; and receiving, by the initiating WTRU 102a, from the peer WTRU 102b, a response to the link request message including information indicating acceptance of the first link state.

[0133] In certain representative embodiments, a limited connectivity PC5 link may comprise a link that uses only control plane (C-plane) resources, while a full connectivity PC5 link may comprise a connection that uses both user plane (U-plane) and C-plane resources.

[0134] In certain representative embodiments, the initiating WTRU 102a may be configured such that the quality of service (QoS) level associated with a limited connectivity PC5 link is lower than the QoS level associated with a full connectivity PC5 link.

[0135] In certain representative embodiments, the initiating WTRU 102a may be configured such that the frequency of keep-alive messages over a limited connectivity PC5 link is less than the frequency of keep-alive messages over a full connectivity PC5 link.

[0136] In certain representative embodiments, the initiating WTRU 102a may send information to a network entity (e.g., the RAN 104 and / or gNB 180) indicating that the direct link is associated with the first link state.

[0137] In certain representative embodiments, the direct link on PC 5 may be used for vehicle-to-pedestrian (V2P) communications.

[0138] In certain representative embodiments, the initiating WTRU 102a may be a pedestrian WTRU.

[0139] In certain representative embodiments, the profile information may indicate any of: (1) the battery level of the initiating WTRU 102a; or (2) the maximum value of the PC5 link established by the initiating WTRU 102a.

[0140] In certain representative embodiments, the triggering item may be based on any of the following: (1) the location of the initiating WTRU 102a; (2) the battery level of the initiating WTRU 102a; (3) the battery level of the peer WTRU 102b; (4) determining whether the initiating WTRU 102a is indoors or outdoors; and (5) the current state of the application executing on the initiating WTRU 102a.

[0141] Figure 8 is a diagram illustrating security procedures implemented by an initiating WTRU for a direct link with a peer WTRU.

[0142] refer to Figure 8 , including the privacy of the root key identifier (KD ID). The peer WTRU 102 may establish a new root key identifier (KD ID) during the direct link release procedure. When reconnecting with the peer WTRU by including the new KD ID in the DCR message, either WTRU may use the new KD ID. The Link Release Request / Response message may be integrity, confidentiality, and replay protected.

[0143] At block 810, the initiating WTRU 102a may decide / determine to exchange a new KD ID for use in a subsequent connection with the peer WTRU 102b by assigning a new most significant byte (MSB) of the new KD ID. At block 820, the initiating WTRU (e.g., WTRU 102a) may notify the peer WTRU (e.g., WTRU 102b) that it wishes to update the current KD ID shared with the peer WTRU (e.g., WTRU 102b) by sending a Direct Link Release Request message that may include the MSB of the new KD ID.

[0144] At block 830, the peer WTRU 102b may allocate a new least significant byte (LSB) of a new KD ID and may combine the LSB of the new KD ID with the MSB of the received new KD ID to form a new KD ID. The peer WTRU 102b may store the new KD ID by replacing the current KD ID. At block 840, the initiating WTRU (e.g., WTRU 102a) may receive a direct link release response message from the peer WTRU (e.g., WTRU 102b) that may include the least significant byte of the new KD ID. At block 850, the initiating WTRU (e.g., WTRU 102a) may combine the MSB of the new KD ID with the received LSB of the new KD ID to form a new KD ID and may store the new KD ID, replacing the current KD ID.

[0145] A peer WTRU (e.g., WTRU 102b) may receive a Direct Link Release Request message including the MSB of a new KD ID from an initiating WTRU (e.g., WTRU 102a). The peer WTRU (e.g., WTRU 102b) may allocate the LSB of the new KD ID and may combine it with the received MSB of the new KD ID to form a new KD ID. The peer WTRU (e.g., WTRU 102b) may store the new KD ID, replacing the current KD ID. The peer WTRU (e.g., WTRU 102b) may send a Direct Link Release Response message including the LSB of the new KD ID to the initiating WTRU (e.g., WTRU 102a).

[0146] Alternatively, the peer WTRU 102b may establish a new KD ID during a (subsequent) link establishment procedure. The WTRU 102a or 102b may use the new KD ID when reconnecting with its peer WTRU 102b or 102a by including the new KD ID in a DCR message. The Direct Security Mode Command (DSMC) Complete and Direct Communication Accept (DCA) messages used to exchange the KD ID are integrity, confidentiality, and replay protected.

[0147] The initiating WTRU 102a may notify the peer WTRU 102b that it wishes to / will update the identifier of the current KD ID shared with the peer WTRU 102b by sending a Direct Security Mode Command Complete message including the MSB of the new KD ID. The initiating WTRU 102a may receive a Direct Communication Accept message from the peer WTRU 102b including the LSB of the new KD ID. The initiating WTRU 102a may combine the MSB of the new KD ID with the LSB of the new KD ID to form a new KD ID and store the new KD ID, thereby replacing the current KD ID.

[0148] The peer WTRU 102b may receive a Direct Security Mode Command Complete message from the initiating WTRU 102a including the MSB of the new KD ID. The peer WTRU 102b may allocate the LSB of the new KD ID and may combine it with the received MSB of the new KD ID to form a new KD ID. The peer WTRU 102b may store the new KD ID, replacing the current KD ID. The peer WTRU 102b may send a Direct Communication Accept message to the initiating WTRU 102a including the LSB of the new KD ID.

[0149] Figure 9 is a flow chart illustrating a representative method implemented by an initiating wireless WTRU for a direct link with a peer WTRU using a first key identifier of a root key (eg, used for unicast communication between the WTRU and other WTRUs).

[0150] refer to Figure 9 The representative method 900 may include, at block 910, sending, by the initiating WTRU 102a, a release request message to the peer WTRU 102b to release the direct link with the peer WTRU 102b. The release request message may include information indicating first security information associated with a second key identifier of the root key. At block 920, the initiating WTRU 102a may receive a response to the release request message from the peer WTRU 102b, the response including second security information associated with the second key identifier of the root key. At block 930, the initiating WTRU 102a may determine the second key identifier of the root key using the first security information and the second security information. At block 940, the initiating WTRU 102a may send a message including information indicating the second key identifier of the root key to the peer WTRU 102b.

[0151] In certain representative embodiments, the root key identified by the second key identifier is used to provide security for direct communications between the initiating WTRU 102a and the peer WTRU 102b via the new direct link.

[0152] In certain representative embodiments, the first security information includes a first portion of the second key identifier of the root key, and the second security information includes a second portion of the second key identifier of the root key.

[0153] In certain representative embodiments, the first portion includes a set of most significant bits (MSBs) of the second key identifier of the root key, and the second portion includes a set of least significant bits (LSBs) of the second key identifier of the root key.

[0154] In certain representative embodiments, the first portion includes a set of LSBs of the second key identifier of the root key, and the second portion includes a set of MSBs of the second key identifier of the root key.

[0155] In certain representative embodiments, a message including information indicating the second key identifier of the root key may be sent in the clear.

[0156] In certain representative embodiments, a root key identified by the first key identifier may be used to securely protect the release request message and the response to the release request message.

[0157] In certain representative embodiments, the security protection applied to the release request message includes any of the following: integrity protection or confidentiality protection; and the security protection applied to the response to the release request message includes any of the following: integrity protection or confidentiality protection.

[0158] In certain representative embodiments, the initiating WTRU 102a may establish direct communications using a secure layer 2 link over PC5.

[0159] In certain representative embodiments, the release request message may be a direct link release (DLR) request message, and the response to the release request message may be a DLR response message.

[0160] In certain representative embodiments, direct communication may be used for vehicle-to-pedestrian (V2P) communication.

[0161] In certain representative embodiments, the initiating WTRU 102a may be a pedestrian WTRU.

[0162] In certain representative embodiments, the initiating WTRU 102a may store the second key identifier by replacing the first key identifier.

[0163] Figure 10 is a flow chart illustrating another representative method implemented by a peer wireless WTRU to establish a direct link with an initiating WTRU using a first key identifier of a root key (eg, used for unicast communication between the WTRU and other WTRUs).

[0164] refer to Figure 10The representative method 1000 may include, at block 1010, the peer WTRU 102b receiving a release request message from the initiating WTRU 102a to release the direct link with the peer WTRU 102b. The release request message may include information indicating first security information associated with a second key identifier of the root key. At block 1020, the peer WTRU 102b may send a response to the release request message to the initiating WTRU 102a, the response including second security information associated with the second key identifier of the root key. At block 1030, the peer WTRU 102b may determine the second key identifier of the root key using the first security information and the second security information. At block 1040, the peer WTRU 102b may receive a message from the initiating WTRU 102a including information indicating the second key identifier of the root key.

[0165] In certain representative embodiments, the root key identified by the second key identifier is used to provide security for direct communication between the initiating WTRU 102a and the peer WTRU 102b via a new direct link or a direct relink.

[0166] In certain representative embodiments, the first security information includes a first portion of the second key identifier of the root key, and the second security information includes a second portion of the second key identifier of the root key.

[0167] In certain representative embodiments, the first portion includes a set of most significant bits (MSBs) of the second key identifier of the root key, and the second portion includes a set of least significant bits (LSBs) of the second key identifier of the root key.

[0168] In certain representative embodiments, the first portion includes a set of LSBs of the second key identifier of the root key, and the second portion includes a set of MSBs of the second key identifier of the root key.

[0169] In certain representative embodiments, a message including information indicating the second key identifier of the root key may be sent in the clear.

[0170] In certain representative embodiments, a root key identified by the first key identifier may be used to securely protect the release request message and the response to the release request message.

[0171] In certain representative embodiments, the security protection applied to the release request message includes any of the following: integrity protection or confidentiality protection; and the security protection applied to the response to the release request message includes any of the following: integrity protection or confidentiality protection.

[0172] In certain representative embodiments, the peer WTRU 102b may establish direct communications using a secure layer 2 link over PC5.

[0173] In certain representative embodiments, the release request message may be a direct link release (DLR) request message, and the response to the release request message may be a DLR response message.

[0174] In certain representative embodiments, direct communication may be used for vehicle-to-pedestrian (V2P) communication.

[0175] In certain representative embodiments, the peer WTRU 102b may be a pedestrian WTRU.

[0176] In certain representative embodiments, the peer WTRU 102b may store the second key identifier by replacing the first key identifier.

[0177] The system and method for processing data according to a representative embodiment can be executed by one or more processors that execute a sequence of instructions contained in a memory device. Such instructions can be read into the memory device from other computer-readable media such as an auxiliary data storage device. The execution of the sequence of instructions contained in the memory device causes the processor to operate, for example, as described above. In an alternative embodiment, hard-wired circuits can be used instead of software instructions or hard-wired circuits can be combined with software instructions to implement the present invention. Such software can be run remotely on a processor housed in a robotic assistance / apparatus (RAA) and / or another mobile device. In the latter case, data can be transmitted between a RAA or other mobile device containing a sensor and a remote device containing a processor running software by wired or wireless means, and the software performs the scale estimation and compensation as described above. According to other representative embodiments, some of the above-mentioned processing on positioning can be performed in a device containing a sensor / camera, and the remainder of the processing can be performed in a second device after receiving partially processed data from the device containing the sensor / camera.

[0178] Although features and elements are described above in particular combinations, it will be understood by one of ordinary skill in the art that each feature or element may be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a WTRU 102, UE, terminal, base station, RNC, or any host computer.

[0179] In addition, in the above-mentioned embodiments, processing platforms, computing systems, controllers and other devices containing processors are pointed out. These devices may include at least one central processing unit ("CPU") and memory. According to the practice of those skilled in the art of computer programming, references to symbolic representations of actions and operations or instructions may be performed by various CPUs and memories. Such actions and operations or instructions may be considered to be "performed," "computer-executed," or "CPU-executed."

[0180] Those skilled in the art will appreciate that the actions and symbolic representations of operations or instructions comprise manipulation of electrical signals by the CPU. The electrical system represents data bits, which may result in the ultimate transformation or reduction of the electrical signal and the retention of the data bits at memory locations in the memory system, thereby reconfiguring or otherwise changing the operation of the CPU and performing other signal processing. The memory location that retains the data bits is a physical location having specific electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be understood that the representative embodiments are not limited to the aforementioned platforms or CPUs, and that other platforms and CPUs may also support the provided methods.

[0181] The data bits may also be maintained on computer-readable media, including magnetic disks, optical disks, and any other volatile (e.g., random access memory ("RAM")) or non-volatile (e.g., read-only memory ("ROM")) mass storage system readable by the CPU. The computer-readable media may include cooperating or interconnected computer-readable media that reside solely on the processing system or distributed across multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that representative embodiments are not limited to the aforementioned memories, and that other platforms and memories may also support the described methods. It should be understood that representative embodiments are not limited to the aforementioned platforms or CPUs, and that other platforms and CPUs may also support the provided methods.

[0182] In an exemplary embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0183] There is little distinction between hardware implementations and software implementations of various aspects of the system. The use of hardware or software is typically (but not always, as the choice between hardware and software may become important in certain contexts) a design choice that represents a trade-off between cost and efficiency. There may be a variety of media (e.g., hardware, software, and / or firmware) that can implement the processes and / or systems and / or other technologies described herein, and the preferred media may vary depending on the context in which the processes and / or systems and / or other technologies are deployed. For example, if the implementer determines that speed and accuracy are most important, the implementer may choose a media that is primarily hardware and / or firmware. If flexibility is most important, the implementer may choose an implementation that is primarily software. Alternatively, the implementer may choose some combination of hardware, software, and / or firmware.

[0184] The foregoing detailed description has set forth various embodiments of devices and / or processes through the use of block diagrams, flow charts, and / or examples. Where such block diagrams, flow charts, and / or examples include one or more functions and / or operations, it will be understood by those skilled in the art that each function and / or operation within such block diagrams, flow charts, or examples may be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Suitable processors include, by way of example, general-purpose processors, special-purpose processors, conventional processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), field-programmable gate arrays (FPGAs), any other type of integrated circuit (IC), and / or state machines.

[0185] The present disclosure is not limited to the specific embodiments described in this patent application, which are intended to serve as illustrations of various aspects. Many modifications and variations can be made without departing from the spirit and scope of the present invention, as they will be apparent to those skilled in the art. Unless expressly provided as such, any element, action, or description used in this application specification should not be understood as being essential or necessary to the present invention. Based on the foregoing description, functionally equivalent methods and devices within the scope of the present disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and the full scope of equivalents to such entitled claims. It should be understood that the present disclosure is not limited to a particular method or system.

[0186] It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting. As used herein, the term "station" and its abbreviation "STA", "user equipment" and its abbreviation "UE", when referred to herein, may mean: (i) a wireless transmit and / or receive unit (WTRU), such as described below; (ii) any of several embodiments of a WTRU, such as described below; (iii) a device with wireless functionality and / or with wired functionality (e.g., tetherable) configured with (in particular) some or all of the structure and functionality of a WTRU, such as described below; (iii) a device with wireless functionality and / or with wired functionality configured with less than all of the structure and functionality of a WTRU, such as described below; or (iv), etc. The following relative to Figures 1A to 1D Details are provided for an exemplary WTRU that may represent any of the UEs described herein.

[0187] In certain representative embodiments, several portions of the subject matter described herein may be implemented via application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein may be equivalently implemented in whole or in part in an integrated circuit as one or more computer programs running on one or more computers (e.g., one or more programs running on one or more computer systems), one or more programs running on one or more processors (e.g., one or more programs running on one or more microprocessors), firmware, or virtually any combination thereof, and that designing circuits and / or writing code for the software and / or firmware will be well within the skill of those skilled in the art in light of the present disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as program products in a variety of forms, and that the exemplary embodiments of the subject matter described herein apply regardless of the specific type of signal-bearing medium used to actually perform the distribution. Examples of signal-bearing media include, but are not limited to, the following: recordable type media (such as floppy disks, hard drives, CDs, DVDs, digital tapes, computer memory, etc.); and transmission type media (such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.)).

[0188] The subject matter described herein sometimes shows different components contained within or connected to different other components. It should be understood that the architectures depicted in this type are merely examples, and in fact many other architectures that achieve the same function can be implemented. In a conceptual sense, any arrangement of components that achieve the same function is effectively "associated" so that the desired function can be achieved. Therefore, any two components combined herein to achieve a specific function can be considered to be "associated" with each other so that the desired function is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered to be "operably connected" or "operably coupled" to each other to achieve the desired function, and any two components that can be so associated can also be considered to be "operably couplable" to each other to achieve the desired function. Specific examples of operably couplable include, but are not limited to, components that can physically cooperate and / or physically interact and / or components that can wirelessly interact and / or wirelessly interact and / or components that can logically interact and / or components that can logically interact.

[0189] With respect to substantially any plural and / or singular terms used herein, those skilled in the art may convert from the plural to the singular and / or from the singular to the plural, as appropriate, depending on the context and / or application. For clarity, various singular / plural permutations may be explicitly listed herein.

[0190] It will be understood by those skilled in the art that, in general, terms used herein, and particularly in the appended claims (e.g., the bodies of the appended claims), are generally intended to be “open-ended” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “comprising” should be interpreted as “including but not limited to,” etc.). It will also be understood by those skilled in the art that if a specific number of an introduced claim recitation is intended, such intent will be explicitly recited in the claim, and in the absence of such recitations, no such intent is present. For example, where only one item is intended, the term “single” or similar language may be used. To aid understanding, the following appended claims and / or the description herein may contain the use of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that any particular claim containing such introduced claim recitation is limited to embodiments containing only one such recitation by the indefinite article “a” or “an” to introduce the claim recitation. This is true even when the same claim includes the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). The same applies to the use of definite articles to introduce claim recitations. In addition, even if a specific number of introduced claim recitations is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., a bare recitation of "two recitations" without other modifiers means at least two recitations, or two or more recitations). In addition, in those instances where a convention similar to "at least one of A, B, and C, etc." is used, generally speaking, the meaning of such construction is that those skilled in the art will understand the convention (e.g., "a system having at least one of A, B, and C" will include, but is not limited to, systems having A alone, B alone, C alone, both A and B, both A and C, both B and C, and / or both A, B, and C, etc.). In those instances where a convention similar to "at least one of A, B, or C, etc." is used, generally speaking, such construction means that one skilled in the art will understand the convention (e.g., "a system having at least one of A, B, or C" will include, but is not limited to, systems having A alone, B alone, C alone, both A and B, both A and C, both B and C, and / or both A, B, and C, etc.). One skilled in the art will also understand that, in fact, any discrete words and / or phrases presenting two or more alternative terms, whether in the specification, claims, or drawings, should be understood to contemplate the possibility of including one, either, or both of the terms.For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Additionally, as used herein, the term "any of" followed by a listing of a plurality of items and / or a plurality of categories of items is intended to include "any of," "any combination," "any multiples," and / or "any combination of multiples" of the items and / or categories of items, alone or in combination with other items and / or other categories of items. Additionally, as used herein, the terms "group" or "grouping" are intended to include any number of items, including zero. Additionally, as used herein, the term "quantity" is intended to include any quantity, including zero.

[0191] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also described in terms of any individual member or subgroup of members of the Markush group.

[0192] As will be understood by those skilled in the art, for any and all purposes (such as for providing a written description), all ranges disclosed herein also encompass any and all possible subranges and combinations of their subranges. Any listed range can be readily identified as fully describing and enabling the same range to be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily divided into a lower third, a middle third, and an upper third, etc. As will be understood by those skilled in the art, all language such as "up to," "at least," "greater than," "less than," etc. includes the referenced numerals and refers to ranges that can subsequently be divided into subranges as described above. Finally, as will be understood by those skilled in the art, ranges include each individual numeral. Thus, for example, a group having 1 to 3 units refers to groups having 1, 2, or 3 units. Similarly, a group having 1 to 5 units refers to groups having 1, 2, 3, 4, or 5 units, etc.

[0193] Furthermore, the claims should not be read as limited to the order or elements presented unless otherwise stated. Additionally, use of the term "means for..." in any claim is intended to invoke 35 USC §112, 6 or means-plus-function claim format, and any claim without the term "means for..." is not intended to be so.

[0194] A processor associated with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, mobility management entity (MME) or evolved packet core (EPC), or any host. The WTRU may be used in conjunction with a module and may be implemented in hardware and / or software including: a software defined radio (SDR) and other components such as a camera, a video camera module, a video phone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands-free headset, a keyboard, module, a frequency modulation (FM) radio unit, a near field communication (NFC) module, a liquid crystal display (LCD) display unit, an organic light emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an internet browser, and / or any wireless local area network (WLAN) or ultra-wideband (UWB) module.

[0195] Throughout this disclosure, skilled artisans will appreciate that certain representative embodiments may be used in place of or in combination with other representative embodiments.

[0196] In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated into a computer-readable storage medium as instructions for a computer or processor to perform the actions described above. Examples of non-transitory computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method, performed by an initiating wireless transmit / receive unit (WTRU), of establishing a direct link with a peer WTRU using a first key identifier of a root key, the method comprising: sending a release request message to the peer WTRU to release the direct link with the peer WTRU, the release request message including information indicating first security information associated with a second key identifier of the root key; receiving a response message to the release request message from the peer WTRU, the response message including second security information associated with the second key identifier of the root key; determining the second key identifier of the root key using the first security information and the second security information; storing the second key identifier of the root key by replacing the first key identifier of the root key; as well as During a link establishment request with the peer WTRU, a message including information indicating the second key identifier of the root key is sent to the peer WTRU.

2. The method of claim 1 , wherein the root key identified by the second key identifier is used to provide security protection for direct communication between the initiating WTRU and the peer WTRU via a new direct link. 3 . The method of claim 1 , wherein the first security information indicates a first portion of the second key identifier of the root key, and the second security information indicates a second portion of the second key identifier of the root key.

4. The method of claim 3 , wherein the first portion of the second key identifier comprises a set of most significant bits (MSBs) of the second key identifier of the root key, and the second portion of the second key identifier comprises a set of least significant bits (LSBs) of the second key identifier of the root key.

5. The method of claim 1 , wherein the release request message and the response message are security protected; and wherein the security protection applied to the release request message comprises any one of the following: integrity protection or confidentiality protection; and / or the security protection applied to the response message comprises any one of the following: integrity protection or confidentiality protection. The method of claim 1 , further comprising establishing direct communication via a PC5 link. The method of claim 6 , further comprising establishing the direct communication using a secure layer 2 link.

8. The method of claim 7, wherein the release request message is a direct link release (DLR) request message, and the response message to the release request message is a DLR response message. 9 . The method according to claim 7 , wherein the message including information indicating the second key identifier of the root key is a direct communication request message.

10. An initiating wireless transmit / receive unit (WTRU) configured to implement a direct link with a peer WTRU using a first key identifier of a root key, the initiating WTRU comprising: A transmitter / receiver unit, the transmitter / receiver unit being configured to: sending a release request message to the peer WTRU to release the direct link with the peer WTRU, the release request message including information indicating first security information associated with a second key identifier of the root key; receiving a response message to the release request message from the peer WTRU, The response message includes second security information associated with the second key identifier of the root key; a processor configured to determine the second key identifier of the root key using the first security information and the second security information; storing the second key identifier of the root key by replacing the first key identifier of the root key; and and Wherein the transmitter / receiver unit is configured to send a message including information indicating the second key identifier of the root key to the peer WTRU during a link establishment request with the peer WTRU.

11. The initiating WTRU of claim 10, wherein the root key identified by the second key identifier is used to provide security protection for direct communication between the initiating WTRU and the peer WTRU via a new direct link.

12. The initiating WTRU of claim 10, wherein the first security information indicates a first portion of the second key identifier of the root key, and the second security information indicates a second portion of the second key identifier of the root key.

13. The initiating WTRU of claim 12 , wherein the first portion of the second key identifier comprises a set of most significant bits (MSBs) of the second key identifier of the root key, and the second portion of the second key identifier comprises a set of least significant bits (LSBs) of the second key identifier of the root key.

14. The initiating WTRU according to claim 10, wherein the release request message and the response message are security protected; and wherein the security protection applied to the release request message includes any one of the following: integrity protection or confidentiality protection; and / or the security protection applied to the response message includes any one of the following: integrity protection or confidentiality protection.

15. The initiating WTRU of claim 10, wherein the transmitter / receiver unit is configured to establish direct communication via a PC5 link.

16. The initiating WTRU of claim 15, wherein the transmitter / receiver unit is configured to establish direct communication using a secure layer 2 link.

17. The initiating WTRU of claim 16, wherein the release request message is a direct link release (DLR) request message, and the response message to the release request message is a DLR response message.

18. The initiating WTRU of claim 16, wherein the message including information indicating the second key identifier of the root key is a direct communication request message.

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