BR112018070112B1 - METHODS FOR OPERATING A WIRELESS TRANSMISSION/RECEPTION UNIT AND AN EVOLVED B NODE, E, WIRELESS TRANSMISSION/RECEPTION UNIT. - Google Patents

Abstract

comprising transmitting, from the WTRU to an eNB, a request for SPS resources that includes a periodicity of the requested SPS resources and a time offset indicative of a time at which the WTRU expects to have an SPS resource allocated. The method may further comprise receiving, via the WTRU of the eNB, in response to the transmitted SPS resource request, an SPS configuration. The time offset of the transmitted request may include subframe number (SFN) offset relative to SFN 0 of the WTRU. The received SPS configuration may correspond to a PC5 interface, and the SPS configuration may be received through a physical downlink control channel (PDCCH).

Description

REFERENCE TO RELATED DEPOSIT REQUESTS

[001] This application claims the benefit of US provisional application serial No. 62/315,262, filed on March 30, 2016 and US provisional application serial No. 62/366,152, filed on July 25, 2016, the contents of which is incorporated herein by reference.

BACKGROUND

[002] Vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-pedestrian (V2P) (collectively referred to as vehicle-to-everything (V2X)) are vehicular communication systems in which vehicles and roadside units are the communication nodes in a communication network. These nodes provide each other with information such as security warnings and traffic information. In a cooperative approach, vehicle communication systems can be more effective in preventing accidents and traffic congestion than if each vehicle tries to resolve problems individually.

[003] Direct device-to-device (D2D) communications have begun to be supported by major standards bodies such as the Institute of Electrical and Electronics Engineers (IEEE). ) or the Third Generation Partnership Project (3GPP). In the case of 3GPP-based radio access and Long Term Evolution (LTE), support for D2D communications is being introduced to enable cost-efficient, high-capacity public safety communications using LTE technology. This is motivated primarily by the desire to harmonize radio access technology across jurisdictions in order to reduce the company's capital expenditures (CAPEX) and operating expenses (OPEX). radio access technology available for use in public safety (PS) type applications. This is, secondly, driven by the fact that LTE as a scalable broadband radio solution enables efficient multiplexing of different types of services such as voice and video.

[004] Since PS applications typically require radio communications in areas that are often not under the radio coverage of an LTE network, for example, in tunnels, in deep basements, or after catastrophic system outages, there is a need to support D2D communications for PS in the absence of any operating network or prior to the arrival of an AdHoc deployed radio infrastructure. However, even when operating in the presence of an operational network infrastructure, PS communications can typically still require greater reliability than commercial services.

[005] V2X communications standards and technologies can be developed based on current D2D LTE specifications, in addition to potential enhancements to LTE, both D2D and non-D2D, to meet the requirements of the services subgroup to the 3GPP Technical Specification Group on service and system aspects (SA1, or "3GPP Technical Specification Group on Service and System Aspects").

SUMMARY

[006] Methods, apparatus and systems are provided for aligning the generation and transmission of a cooperative awareness message (CAM) with a semi-persistent scheduling resource timing (SPS). "), including transmitting an indication to change an SPS configuration to a node B based on a trigger event, wherein the indication to change the SPS configuration includes a request to change at least one of a scheduling interval and an offset from a current SPS configuration, reconfigure the current SPS configuration based on the indication to change the SPS configuration, and transmit the CAM using SPS resources in accordance with the changed SPS configuration.

[007] A method for operating a wireless transmit/receive unit (WTRU) may comprise transmitting from the WTRU to an evolved Node B (eNB) , a request for semi-persistent scheduling (SPS) resources that includes a periodicity of the requested SPS resources and a time offset indicative of a time at which the WTRU expects to have an SPS resource allocated. The method may further comprise receiving from the eNB, via the WTRU, in response to the transmitted SPS resource request, an SPS configuration. The time offset of the transmitted request may include subframe number (SFN) offset relative to SFN 0 of the WTRU. The received SPS configuration may correspond to a PC5 interface. The SPS configuration can be received over a physical downlink control channel (PDCCH).

BRIEF DESCRIPTION OF THE DRAWINGS

[008] A more detailed understanding can be obtained from the following description, given by way of example in conjunction with the attached drawings, in which: Figure 1A is a system diagram of an exemplary communications system, in which one or more disclosed embodiments may be implemented; Figure 1B is a system diagram of an exemplary wireless transmit/receive unit (WTRU) that may be used in the communications system illustrated in Figure 1A; Figure 1C is a system diagram of an exemplary radio access network and an exemplary backbone network that may be used in the communications system illustrated in Figure 1A; Figure 2 is a diagram of an exemplary CAM timing timeline; Figure 3A is a diagram of an exemplary 4-bit range value indicator used to signal one of 10 or more desired preconfigured SPS ranges; Figure 3B is an illustration of an exemplary MAC control element (CE) design comprising a range indicator value and a frame number system (SFN); Figure 4 is an illustration of an exemplary MAC PDU comprising a plurality of MAC CEs; Figure 5 is a diagram of a procedure exemplifying a requested displacement or displacement change; and Figure 6 is a diagram of an exemplary procedure for an SPS configuration change indication; Figure 7 is a flowchart illustrating a method for reconfiguring shortened SPS using an acknowledgment message; and Figure 8 is a list of exemplary trigger events for SPS reconfiguration.

DETAILED DESCRIPTION

[009] Figure 1A is a diagram of an exemplary communications system 100 in which one or more disclosed embodiments can be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcasting, etc., to multiple wireless users. Communications system 100 may enable multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, communications systems 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 - Frequency Division Multiple Access), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA - Single-Carrier Frequency Division Multiple Access) and similar.

[0010] As shown in Figure 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN). Access Network) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be recognized 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 may be configured to transmit and/or receive wireless signals and may include user equipment (UE - User Equipment), a mobile station, a fixed or mobile subscriber unit, a pager, a cell phone, a personal digital assistant (PDA), a smart phone, a laptop-type computer, a netbook-type computer, a personal computer, a wireless sensor, consumer electronics, and the like .

[0011] The communications system 100 may also include a base station 114a and a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to interface wirelessly with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the main network 106 , the Internet 110 and/or the networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a node B, an eNodeB, a source Node B , a source eNodeB, a site controller, an access point (AP - Access Point), a wireless router and the like. Although base stations 114a, 114b are each shown as a single element, it will be recognized that base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

[0012] Base station 114a may be part of the RAN (Radio Access Network) 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 within a specific geographic region, which may be called a cell (not shown). The cell can also be 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, for example, one for each sector of the cell. In another embodiment, the base station 114a may employ Multiple Input Multiple Output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell.

[0013] Base stations 114a, 114b may communicate with one or more of WTRUs 102a, 102b, 102c, 102d via an air interface 116, which may be any wireless communication link (e.g., radio frequency (RF) ), microwaves, infrared (IR, "infrared"), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0014] More specifically, as indicated above, the communications 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, base station 114a in RAN 104 and WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS), universal terrestrial radio access (UTRA, for "Universal Terrestrial Radio Access") which can establish air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA). ).

[0015] In another embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology, such as evolved UMTS radio terrestrial access (E-UTRA), which may establish the air interface 116 through the use of long term evolution (LTE) and/or LTE advanced (LTE-A).

[0016] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as 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 - Global System for Mobile Communications), Enhanced Data Rates for GSM Evolution (EDGE - Enhanced Data Rates for GSM Evolution), GSM EDGE (GERAN) and similar.

[0017] The base station 114b in Figure 1A may be a wireless router, a source node B, a source eNodeB, or an access point, for example, and may utilize any RAT ("Radio Access Technology", or radio access technology) suitable for facilitating wireless connectivity in a localized area, such as a workplace, a home, a vehicle, a campus, and the like. In one 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 another 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, etc.) to establish a picocell or a femtocell . As shown in Figure 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not be necessary to access the Internet 110 through the main network 106.

[0018] The RAN 104 may be in communication with the core network 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 WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing services, location-based mobile services, prepaid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions. , such as user authentication. Although not shown in Figure 1A, it will be recognized that RAN 104 and/or core network 106 may be in direct or indirect communication with other RANs employing the same RAT, such as RAN 104, or a different RAT. For example, in addition to being connected to RAN 104, which may utilize an E-UTRA radio technology, the core network 106 may also be in communication with another RAN (not shown) that employs a GSM radio technology.

[0019] The main network 106 can also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN ("Public Switched Telephone Network") 108, the Internet 110 and/or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide conventional telephone service (POTS - Plain Old Telephone Service). The Internet 110 may include a global system of computer networks and interconnected devices that use common communication protocols, such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and User Datagram Protocol (UDP). and the Internet Protocol (IP) in the TCP/IP suite of Internet protocols. Networks 112 may include wired or wireless communications networks owned and/or operated by other service providers. For example, networks 112 may include another core network connected to one or more RANs, which may employ the same RAT, such as RAN 104, or a different RAT.

[0020] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities, that is, the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks through different wireless links. For example, the WTRU 102c shown in Figure 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and the base station 114b, which may employ a cellular-based radio technology. IEEE 802.

[0021] Figure 1B is a system diagram of an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a key block 126, a monitor/touchpad 128, a memory no. removable memory 130, a removable memory 132, a power source 134, a global positioning system (GPS) electronic circuitry 136, and other peripherals 138. It will be recognized that the WTRU 102 may include any subcombination of the aforementioned elements while remaining consistent with a modality.

[0022] 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 in association with a DSP core, a controller, a microcontroller, application specific integrated circuits (ASICs), field programmable gate array (FPGA) circuits, any other type of integrated circuit ("Integrated Circuit"), a state machine and the like. The processor 118 may perform signal-to-code conversion, data processing, power control, input/output processing, and/or any other functionality that enables 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 depicts the processor 118 and the transceiver 120 as separate components, it will be recognized that the processor 118 and the transceiver 120 may be integrated together in an electronic package or electronic circuit.

[0023] 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 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 another embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV or visible light signals, for example. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and receive both RF and light signals. It will be recognized that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0024] Furthermore, although the transmit/receive element 122 is depicted in Figure 1B as a single element, 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) to transmit and receive wireless signals over the air interface 116.

[0025] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As indicated above, the WTRU 102 may have capabilities in multiple mode. In this way, transceiver 120 may include multiple transceivers to enable WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, for example.

[0026] The processor 118 of the WTRU 102 may be coupled to the speaker/microphone 124, the key block 126, and/or the monitor/touchpad 128 (e.g., a liquid crystal display (LCD) display unit. "Liquid Crystal Display") or an organic light-emitting diode (OLED) display unit, and may receive user input from the same. Processor 118 may also output user data to speaker/microphone 124, keyboard 126, and/or monitor/touchpad 128. Additionally, processor 118 may access information from any suitable memory type, such as memory. non-removable memory 130 and/or removable memory 132, and store data therein. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of storage device. memory storage. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital memory (SD) card, and the like. In other embodiments, the processor 118 may access information from memory that is not physically located in the WTRU 102, such as in a server or a home computer (not shown), and store data therein.

[0027] Processor 118 may receive power from power source 134 and may be configured to distribute and/or control power to other components in WTRU 102. Power source 134 may be any device suitable for powering 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 and the like.

[0028] Processor 118 may also be coupled to the electronic circuitry of GPS 136, which may be configured to provide location information (e.g., longitude and latitude) relative to the current location of WTRU 102. In addition to, or Instead of GPS electronic circuitry information 136, the WTRU 102 may receive location information via air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location with based on the timing of signals received from two or more nearby base stations. It will be recognized that the WTRU 102 can acquire location information through any suitable location determination method, while remaining compatible with one modality.

[0029] The processor 118 may also be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wireless or wired connectivity. For example, peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photographs or video), a Universal Serial Bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, a browser Internet and similar.

[0030] Figure 1C is a system diagram of the RAN 104 and the core network 106, according to one embodiment. As indicated above, RAN 104 may employ an E-UTRA radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. RAN 104 may also be in communication with core network 106.

[0031] RAN 104 may include eNodeBs 140a, 140b, 140c, although it should be recognized that RAN 104 may include any number of eNodeBs, while remaining consistent with one embodiment. The eNodeBs 140a, 140b, 140c may each include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the eNodeBs 140a, 140b, 140c may implement MIMO technology . Thus, the eNodeB 140a, for example, may use multiple antennas to transmit and receive wireless signals from the WTRU 102a.

[0032] Each of the eNodeBs 140a, 140b, 140c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, auto-switch decisions, uplink user scheduling, and /or downlink and similar. As shown in Figure 1C, eNodeBs 140a, 140b, 140c can communicate with each other via an X2 interface.

[0033] The core network 106 shown in Figure 1C may include a mobility management communication port (MME) 142, a server communication port 144, and a packet data network (PDN) communication port ) 146. Although each of the foregoing elements is shown as part of the core network 106, it will be recognized that any of these elements may be owned and/or operated by an entity other than the core network operator.

[0034] The MME 142 may be connected to each of the eNodeBs 140a, 140b, 140c in the RAN 104 via an S1 interface, and may serve as a control node. For example, the MME 142 may be responsible for user authentication of WTRUs 102a, 102b, 102c, bearer activation/deactivation, selection of a specific server communication port during an initial pinning of WTRUs 102a, 102b, 102c, and the like. . The MME 142 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 or WCDMA.

[0035] The server communication port 144 may be connected to each of the eNodeBs 140a, 140b, 140c in the RAN 104 via the S1 interface. The serving communication port 144 may generally route and forward user data packets destined to/from the WTRUs 102a, 102b, 102c. The server communication port 144 may also perform other functions, such as anchoring user planes during automatic changes between eNodeBs, triggering paging when downlink data is available to the WTRUs 102a, 102b, 102c, managing and storing the contexts of the WTRUs 102a, 102b, 102c and similar.

[0036] The serving communications port 144 may also be connected to the PDN communications port 146, 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.

[0037] The main network 106 can facilitate communications with other networks. For example, the core network 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 fixed-line communications devices. For example, the backbone network 106 may include, or may communicate with, an IP communications port (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the core network 106 and the PSTN network 108. Additionally, the core network 106 may provide WTRUs 102a, 102b, 102c with access to networks 112, which may include other wired or wireless networks that are owned and/or operated by other service providers.

[0038] Another network 112 may be additionally connected to a wireless local area network (WLAN) 160 based on IEEE 802.11. The WLAN 160 may include an access router 165. The access router may contain port functionality. The access router 165 may be in communication with a plurality of access points (APs) 170a, 170b. Communication between the access router 165 and the APs 170a, 170b can be via a wired Ethernet (IEEE 802.3 standards), or any type of wireless communication protocol. The AP 170a is in wireless communication via an air interface with the WTRU 102d.

[0039] Vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-pedestrian (V2P) (collectively referred to as vehicle-to-everything (V2X)) are vehicular communication systems in which vehicles and roadside units are the communication nodes in a communication network, which provide each other with information, such as security warnings and traffic information. As a cooperative approach, vehicle communication systems can be more effective in preventing accidents and traffic congestion than if each vehicle tried to resolve these problems individually.

[0040] Generally, vehicular networks are considered to contain two types of nodes: vehicles and roadside stations. Both are dedicated short-range communications (DSRC) devices. DSRC typically operates in the 5.9 GHz band with a bandwidth of 75 MHz and an approximate range of about 1,000 meters.

[0041] A standard for vehicular communications, including V2V, V2I, and V2P, can be developed by adapting current LTE specifications. For example, V2V communications that use an existing device-to-device (D2D) framework, for example, ProSe, can be considered.

[0042] V2X communication requirements were developed in 3GPP by SA1. Specifically, these requirements call for the transmission of short messages, on the order of 50 to several hundred bytes, with high reliability at the same AS level (e.g., up to 90%) and with low latency, e.g., as small as 100 ms. , in order to support specific use cases such as forward collision warning, loss of control warning, and emergency lockout.

[0043] D2D communications are being developed for public safety (PS) communications using LTE technology. Since PS applications typically require radio communications in areas that are often not under the radio coverage of an LTE network, for example, in tunnels, in deep basements, or after catastrophic system outages, there is a need for support D2D communications for PS in the absence of any operating network or before the arrival of an AdHoc deployed radio infrastructure. However, even when operating in the presence of operational network infrastructure equipment, PS communications may typically still require greater reliability than commercial services.

[0044] PS-type applications, for example among first responders, may, at a minimum, include push-to-talk direct speech services with the use of multiple talk groups. Additionally, PS-type applications to make efficient use of the capabilities of LTE broadband radio providers can include services such as video uploading or downloading.

[0045] It is expected that once installed, D2D communications can be available not only for PS-type applications, but also for commercial use cases. An example might be the case of utility companies that often also require support for two-way radio communications in areas not covered by the network infrastructure. Additionally, D2D services such as sensing can be suitable signaling mechanisms to enable proximity-based services and traffic offloading using LTE-based radio access in commercial use cases.

[0046] D2D communications utilizing LTE-based radio access can be designed to operate in network control mode and WTRU standalone mode, hereinafter referred to as Mode 1 and Mode 2, respectively. Mode 1 (i.e. controlled network) may only be possible under certain conditions, for example if the D2D terminal is in radio range of an LTE base station. The D2D terminal can return to Mode 2 operation (i.e. standalone WTRU) in the case where the WTRU cannot communicate with the LTE base station. In this case, it will mainly use channel access parameters pre-stored in the terminal itself.

[0047] For D2D communications using Mode 1, LTE base station may reserve a selected set of uplink (UL) subframes to allow D2D transmissions. The LTE base station may also feature a set of UL subframes with associated parameters in which D2D communications to neighboring cells or Mode 2 terminals may be received. Not necessarily the entire LTE system bandwidth (BW) may be available for D2D transmissions in a subframe reserved for D2D. When operating in mode 1, radio resources for D2D communications can be granted to a D2D terminal by the serving cell. The D2D network grant may be preceded by a UL transmission by the terminal on the cellular UL channel that indicates to the base station the amount of D2D data available. The D2D grant received by the D2D terminal from the LTE base station on the cellular DL channel allows the D2D terminal to use certain selected radio resources, that is, some radio blocks (RBS) occurring in some subframes over a certain scheduling period.

[0048] A D2D terminal may transmit a Schedule Assignment (SA) message in a first set of one or more D2D subframes, and then may transmit the D2D data in a second set of D2D subframes in a scheduling period. Scheduling assignments, among others, may contain an identifier field, a coding and modulation scheme (MCS) field, a resource indicator, and a timing advance (TA) field. D2D data packets, among others, may contain a medium access control (MAC) header with source and destination addresses. Multiple logical channels can be multiplexed and sent as part of a single transport block (TB) in a given D2D subframe by a WTRU.

[0049] For D2D communications using Mode 2, D2D terminals can select time/frequency radio resources autonomously. Channel access parameters such as subframes for use with SA control message transmissions and corresponding D2D data, scheduling periods, or monitoring subframes can be preconfigured and stored on the D2D terminal. Except for traffic volume indication of previous UL and D2D grant phase of DL, Mode 2 terminals can follow the same transmission behavior as Mode 1 terminals and will also transmit SAs followed by D2D data at periods in the schedule .

[0050] For both Mode 1 and Mode 2 D2D communications, D2D terminals can also transmit D2D signals such as, for example, D2D synchronization signals and channel messages to assist receivers in demodulating their transmissions.

[0051] D2D communications using LTE-based radio access may carry voice channels or data packets or data streams. A special case of D2D communications is the D2D discovery service. D2D discovery, unlike voice channels, can typically require only small packet transmissions that can often fit into one, two, or at most a few subframes. For example, these packets may contain application data announcing the availability of devices or software applications (SW) to participate in D2D data exchanges with nearby terminals.

[0052] D2D discovery may or may not use the same channel access protocol as that used for D2D communication for voice or generic D2D data. For D2D discovery when in coverage of an LTE base station, D2D discovery resources may be allocated separately from those used for D2D communication with voice or generic D2D data. Radio resources for sensing D2D messages can be autonomously selected by D2D terminals from a pool of resources reserved by the eNB and time and frequency radio resources that occur periodically in certain UL subframes (e.g., Type 1 discovery ) or they can be explicitly allocated by the LTE serving cell at D2D terminals (e.g., type 2 discovery). The latter case is similar to Mode 1 D2D communications. Transmissions of scheduling assignments may not be necessary when transmitting D2D discovery messages. In some cases, however, even D2D terminals that transmit only D2D discovery messages may still be required to transmit auxiliary D2D synchronization signals to assist receivers.

[0053] 3GPP is currently evaluating the feasibility of V2X communications based on current D2D LTE specifications, as well as identifying potential LTE improvements (both D2D and potentially non-D2D) necessary to satisfy SA1 requirements. As part of the feasibility study, 3GPP identified four main V2X scenarios.

[0054] Scenario 1 supports V2V operation based on PC5 only. PC5 includes transmitting V2X data from a source WTRU, e.g., a vehicle, to a destination WTRU, e.g., another vehicle, a road infrastructure device, a pedestrian, or the like, via direct ProSe communication via an interface PC5 between the WTRUs (side link).

[0055] Scenario 2 supports Uu-based V2V operation only. Uu includes transmission of V2X data from a source WTRU (e.g., a vehicle) to a destination WTRU (e.g., another vehicle, road infrastructure, a pedestrian, etc.) via an eNB via a Uu interface ( uplink and downlink).

[0056] Scenario 3A includes a WTRU that transmits a V2X message to other WTRUs on a lateral link. One of the receiving WTRUs is a WTRU type roadside unit (RSU) that receives the V2X message on a lateral link and transmits it to the E-UTRAN on an uplink. E-UTRAN receives the V2X message from the WTRU type RSU and then transmits it to multiple WTRUs in a local area on downlink.

[0057] Scenario 3B includes a WTRU that transmits a V2X message to the uplink E-UTRAN and the E-UTRAN transmits the V2X message to one or more RSUs of type WTRU. Then, the WTRU type RSU transmits the V2X message to other WTRUs on a lateral link.

[0058] LTE can use semi-persistent scheduling (SPS) as its form of semi-static resource allocation which is used to avoid scheduling overhead associated with dynamic resource scheduling for services with regular transmissions of relatively small payloads (e.g., VoIP ). SPS is possible for both uplink and downlink transmissions.

[0059] For uplink SPS, as new data arrives into a buffer of a WTRU, the WTRU may report an indication of its buffer status using a buffer state report (BSR) message. buffer status report"). BSR control elements typically contain a logical channel group ID and one or more fields that correspond to the buffer size. A sidelink-specific BSR may also include a destination index, since any data temporarily stored on the sidelink is for transmission to another WTRU rather than the reporting eNB.

[0060] With SPS, a terminal may be provided with scheduling on a physical download control channel (PDCCH) to indicate a grant that is valid for every Nth subframe. The periodicity, or value of N, of SPS resources is provided by Radio Resource Control (RRC) signaling, while activation/deactivation and resource details are provided by PDCCH signaling using the SPS cellular radio network temporary identifier (C-RNTI). A dynamic scheduling command that occurs in the same subframe as an SPS resource can take precedence over the SPS resource. This behavior is useful in the case where the regular resource allocated in a WTRU needs to be increased occasionally.

[0061] SPS retransmissions for downlink can always be dynamically scheduled, while for uplink, they can be dynamically scheduled, or can follow semi-persistently allocated subframes. SPS is further supported only on the primary cell (PCell) or primary secondary cell (PSCell) (in case of dual connectivity (DC)).

[0062] One of the main basic message types transmitted to V2X as V2X traffic is a cooperative awareness message (CAM). CAM messages contain cooperative awareness information that road users and roadside infrastructure exchange to be informed about other vehicle position, dynamics and attributes. Regularly exchanging this information can be key to many highway safety and traffic efficiency applications.

[0063] The CAM is made up of specific containers, which can be mandatory or optional. Each CAM message may contain at least one basic container (which contains basic information related to the source intelligent transport system station (ITS-S)) and one high-frequency container which contains highly dynamic information from the ITS-S In addition, a CAM message may also contain a low-frequency container that contains static, non-highly dynamic information from the originating ITS-S and one or more special containers that contain information specific to the ITS vehicle function. -S for original vehicle - namely for special vehicles.

[0064] Some exemplary ITS elements include active traffic management systems, traffic cameras to monitor weather conditions, traffic congestion or other incidents, variable message signs that may contain amber alerts or other messages, highway information systems, of road and weather information, ramp meter, traffic data collectors and traffic management centers.

[0065] Transmission of CAM messages may be periodic, with certain deviations or adjustments in the period that are based on vehicle position, vehicle speed, vehicle position, and the time elapsed since the last generation of a CAM message. Additionally, the low-frequency container needs to be included in a CAM if the time elapsed since the generation of the last CAM with the same low-frequency container is equal to or greater than 500 ms. This same rule also applies to the special container.

[0066] To employ V2X communications, E-UTRAN must be able to support a maximum latency of 100 ms for most use cases. While a pre-collision detection use case has a more stringent 20 ms requirement, the basic assumption in 3GPP for standardizing any V2X-related enhancements has been a 100 ms requirement for RAN-associated latency.

[0067] SPS is a preferred candidate for transmitting V2V messages in the UL for scenario 2 and scenario 3 described above due to the primarily periodic nature of CAM traffic. However, UL capacity in Uu is difficult to meet for SPS periods of 40 ms or less due to the large number of vehicles in an urban scenario that would need to transmit on the uplink, and therefore longer SPS periods may need to be considered.

[0068] Methods for determining, reporting, and receiving SPS periodicity and displacement change indicators are provided. The latency in transmitting a CAM message by E-UTRAN may comprise one or more of the following factors. As a first component, latency can be understood as a time between when the CAM message is generated by the V2X application and when the next UL SPS resource allocating in the WTRU becomes available. As a second component, latency can be comprised of a time required to receive and process the CAM message in the network and can further depend on whether the CAM message is sent to the main network, or whether processing remains in the eNB. As a third component, latency can be understood as the time required to transmit the message on the downlink channel to the destination WTRU using Singlecell Point-to-Multipoint (SC-PTM) scheduling. , evolved multimedia broadcast and multicast service (eMBMS - evolved Multimedia Broadcast Multicast Service) or point-to-point broadcast.

[0069] As the SPS period increases, the portion of latency attributed to the first component increases. This increase can only be avoided if CAM message generation is truly periodic and if the SPS period can be aligned with CAM message generation.

[0070] Based on the CAM generation frequency, true periodicity may not be assumed and the CAM generation pattern, compared to the SPS pattern, may be subjected to changes in periodicity and changes in displacement.

[0071] Changes in periodicity may occur in the CAM generation pattern. For example, the CAM generation interval can be changed dynamically, moving between 100 ms when the vehicle position, heading and speed are changing, and 1 second when the vehicle position, heading and speed do not change. Additionally, there may be time periods where the periodicity may be somewhere in between these values, for various CAM generation intervals specified by the basic Cooperative Awareness (CA) service. As a result, the CAM generation period can change dynamically over time and assume any period between 100 ms and 1 second, in theory.

[0072] Changes in displacement may occur in the cam generation pattern. Transitions between one CAM interval and another CAM interval when these intervals are not multiples of 100 ms can result in a change in offset between message generation and a fixed SPS schedule.

[0073] Consequently, these changes to the CAM message generation pattern may result in an increase in the first latency component and potentially not meeting the 100 ms latency requirements when SPS is used.

[0074] Additionally, there may be a payload of variable size. SPS is best suited for periodic traffic with a fixed resource allocation size, such as Voice over Internet Protocol (VoIP). Although deviations in message size can be easily handled through dynamic scheduling, frequent dynamic scheduling can result in increased scheduling overhead and significantly reduce the benefit of SPS. This reduction in benefit may be even more pronounced in the case of V2V traffic, where the assumption (at least for urban scenarios) is that there is a dense concentration of vehicles, and these vehicles need to receive this dynamic scheduling on a regular basis. On the other hand, resource allocation results in a waste of SPS resources that could be used by the scheduler for other purposes.

[0075] CAM messages can be about 190 bytes when they include only one high-frequency container or about 300 bytes when they contain the high-frequency container and one or more low-frequency containers. It is also possible for CAM messages with the special container to deviate from these sizes. The sizes of CAM messages are therefore quite variable. An SPS allocation size can be defined more dynamically without relying exclusively on dynamic scheduling.

[0076] It should be understood that the term D2D data may refer to any type of D2D-related communication between D2D terminals. For example, without loss of generality, D2D data may include data packets, such as those containing voice or segments thereof, may include Internet Protocol (IP) packets or segments thereof, such as those used to transfer files by downloading or uploading , continuous or bidirectional video transmission, may include D2D control signaling and/or may include D2D discovery or service or availability messages. Furthermore, the embodiments described herein are described in the general context of the 3GPP D2D communications capability, but the concept may be applicable to other capabilities such as D2D discovery, for example.

[0077] The following concepts are introduced in the present invention: a WTRU can send a requested offset or offset change to SPS; a WTRU may send an indication to change an SPS configuration; a WTRU can send an indication to release specific resources; multiple SPS configurations can be provided and methods of enabling/disabling the configurations are disclosed; SPS message size can be configured via an application layer; the size of the SPS message can be associated with a QCI for the logical channel; allocation size changes can be accumulated based on SPS transmissions; methods for periodic SPS allocation size increases are disclosed; WTRU may request SPS based on a trigger from an application; enhancements to an SPS configuration can be received by a WTRU. Enhancements may include the format and timing of assistance information, allowed offsets that the WTRU can request to change, an index of an SPS configuration, logical channels allowed for the SPS configuration or resource configuration. A new trigger for side-link BSR can be provided to send offset change information. Access stratum (AS) and application-based calculated triggers to send configuration/offset change or SPS activation/deactivation can be based on higher layer information. A logical channel prioritization (LCP) can be applied to an SPS grant based on the logical channel association and SPS configuration. A WTRU may select a single SPS grant in the case of grants occurring simultaneously. An LTE adaptation layer is presented to enable/disable the use of SPS, and provide timing, based on timing offset and interval information.

[0078] As described in the present invention, the term "WTRU" may represent a single D2D-enabled device, which may be an actual mobile device, a vehicle that has D2D communication capability, and/or a roadside unit intended for optimize V2X system performance. A "WTRU" can also represent a mobile device that communicates directly with an eNB. Similarly, the term "eNB" represents a traditional eNB employed in LTE infrastructure communication, and which can provide communication services for D2D communications in coverage. The eNB may be installed on a cell tower, or it could be properly installed as a roadside unit, in which case, in the latter case, the eNB may have functionality limited to D2D communication only.

[0079] As further described in the present invention, reference is made to CAM messages that are specifically referencing V2V-related application messages, which are transmitted over an AS radio interface. In the described embodiments, CAM messages can represent any type of upper layer messages that a WTRU would need to transmit using SPS, whether via uplink or sidelink. This message can have the property of time criticality or delay sensitivity. These messages can also be considered periodic for most of the time, or for a significant amount of time, with occasional changes in the period, timing (offset) or size of the message.

[0080] Figure 2 illustrates a diagram of an exemplary timeline of CAM 200 timing. In view of the exemplary timeline shown in Figure 2, potential problems may become apparent in connection with the use of a fixed period (e.g. , 100 ms) 202 for SPS in the case of a highly plausible high traffic scenario for a vehicle. In this example, the vehicle performs the following actions identified by the following exemplary timeline.

[0081] After a period of time in which the vehicle satisfies a first condition, for example, a speed, position or heading, the vehicle stops satisfying condition 1, for example, the vehicle stops 204. The vehicle again begins to satisfy condition 1, when it starts moving again 206. The vehicle may start to decelerate 208. The vehicle stops satisfying condition 1, the same for 210. The vehicle again, after 160 ms, after the last CAM, starts to satisfy condition 1, for example, starts moving again, but only very temporarily 212. The CAMs then become spaced 160 ms apart for 3 intervals, until they reoccur at a 1 second interval.

[0082] Consequently, the resulting timing of CAMs using an SPS configuration over a period of 100 ms is shown on timeline 200. This configuration can result in potentially large amounts of SPS resources that are not used by WTRU 214 216, which the scheduler cannot reuse. Although resources may be implicitly freed after a series of empty transmissions by the WTRU, frequent transitions between the two states may still cause some resource waste, and the WTRU may still need to communicate with the eNB to reallocate resources. Additionally, potentially large wait delays (in the range of 30 ms to 90 ms) can result from this configuration. These large hold delays would need to be added to the overall E-UTRAN latency for V2X messages, and will likely result in the loss of the 100 ms requirement.

[0083] It will be understood that although the aforementioned problems are described with reference to CAM messages, problems may occur for other types of application-related traffic, such as VoIP, real-time control, etc. As a result, the embodiments disclosed in the present invention can apply not only to the V2V use case, but to any use case in which the traffic has properties similar to CAM.

[0084] An SPS configuration is described in which a WTRU may request the use of SPS and/or an SPS configuration is provided by the eNB. For example, a WTRU may request the use of SPS from the eNB. This request can be sent by the WTRU through RRC signaling. For example, a WTRU that requests SPS from the eNB can do so using an RRC WTRUSidelinkInformation message. The WTRU may send the request for use of SPS as a result of a trigger from the upper layers, in one embodiment, using an adaptation layer described herein.

[0085] The WTRU may include one or more information elements related to SPS parameters in the SPS configuration request. For example, the WTRU may include information relating to one or more desired SPS configurations, each including one or more of a periodicity and/or offset of the SPS configuration, transmission size (e.g., transport block size ( TBS)), number of RBs resource blocks, etc. In another example, the WTRU may include information related to the desired parameters of one or more requested SPS configurations in the form of a set of indices, each pointing to a row in a preconfigured table, where each row in the table references a set of desired SPS parameters for this desired SPS configuration.

[0086] In response to the SPS request from the WTRU, the eNB may transmit an SPS configuration to the WTRU. Alternatively, the eNB may transmit an SPS configuration to the WTRU without an SPS request and may thereby transmit the SPS configuration autonomously or by some other trigger.

[0087] To transmit messages via Uu, the WTRU can use the uplink SPS existing in LTE. Furthermore, a similar SPS configuration can be configured for side-link SPS, and the side-link SPS configuration can be sent through RRC messages, or the combination of RRC messages with a MAC control element (CE) and messages PHY at PDCCH. The uplink or sidelink SPS configuration may further contain a configuration (e.g., configuration information) of WTRU assistance information and/or a sidelink configuration.

[0088] WTRU assistance information includes information sent by the WTRU to the eNB to assist the eNB in adjusting the SPS parameters. Various types of configuration information in relation to WTRU assistance information are possible. The WTRU may receive configuration assistance information from the WTRU regarding whether assistance information can be provided to the eNB related to the SPS schedule, and what type of assistance information can be provided (e.g. timing, period) and how send this information. The WTRU assistance information configuration can allow or disallow the WTRU to transmit SPS scheduling assistance information. The WTRU may receive a list of possible timing offsets for the SPS resource pattern, where the offset may be set relative to a specific SFN/subframe number and/or relative to the start of the scheduling period. The WTRU may receive a list of possible SPS periods/intervals from which it may select or request changes. The list of possible SPS periods/intervals may be a subset of the possible SPS that the WTRU can support or that the eNB can configure or assign to a given WTRU. The WTRU can potentially only request a change to one of the list of configured eNB periodicities. The WTRU may receive the configuration of the resource (e.g., a UL) used to send the assistance information. For example, assistance information can be sent using dedicated SR resources configured by the eNB specifically for this purpose. The WTRU can receive the permissible time instances and frequency with which assistance can be sent. For example, the WTRU may be configured to provide assistance at the end of each scheduling period, or periodically based on a period configured by the eNB.

[0089] For a side link, an SPS configuration of the subframes in each scheduling period that corresponds to the SPS resource may be provided. These subframes can be the same in each scheduling period, and can also define the subframes for retransmission of data transmitted using SPS, as well as the number of retransmissions required.

[0090] The WTRU may receive, in an SPS configuration, a list of possible SPS resource configurations that can be activated. This list can be implemented using a set of indexes pointing to a predefined lookup table. The WTRU can activate one of the possible SPS configurations from the list. Alternatively, the WTRU can have multiple SPS configurations active simultaneously.

[0091] The resource configuration of the SPS configuration, or each configuration in the SPS configuration list, may be provided. For example, each SPS configuration can correspond to a specific pattern of SPS resources with a periodicity (i.e., interval), timing offset, allocation size, actual resources used (resource blocks), or allocation size pattern. An allocation size pattern can be set such that 1 in a specific number of SPS resources has a different number (that is, an increase or decrease) in the amount of resources relative to the SPS allocation size. For sidelink SPS, the resource configuration can be configured as in the case of uplink SPS, where the interval/period is configured in the RRC, and the timing/offset and resource configuration can be indicated to the WTRU by the eNB, for example, by PHY layer signaling. In the case of a lateral link, the PHY layer signaling could be PDCCH with DIC format 5, sent using an SPS C-RNTI configured at the RRC layer. Alternatively, for side-link SPS, the entire resource configuration can be sent in RRC messages (for example, the allocation interval, offset and size and/or allocation pattern can be sent through RRC messages).

[0092] An SPS configuration may further include identifying the data that the WTRU must transmit or prioritize when using each specific SPS configuration, which could be in the form of an allowable logical channel, group of logical channels, priority (e.g. example, ProSe Per-Packet Priority (PPPP), radio bearer, application ID, QCI, or similar. For example, the WTRU can be configured with multiple SPS configurations and each SPS configuration must be used to transmit data for a specific logical channel or group of logical channels.

[0093] An SPS configuration may further include an identification of the destination ID (or IDs) of the side link to which the SPS configuration applies.

[0094] An SPS timing change is provided. A WTRU that sends a requested offset or offset change to the SPS is provided. As shown in the timeline shown in Figure 2, in order to avoid additional delay for the delivery of CAM messages associated with waiting for the next SPS resource to transmit the pending CAM, CAM message generation must be aligned to the timing of the SPS resource. Assuming the same interval for both CAM and SPS, the waiting delay will be zero.

[0095] However, the SPS offset configured by the eNB (i.e. the timing of granting PDCCH with C-RNTI of SPS in the case of SPS of UL) is completely decided by the eNB, therefore this cannot be guaranteed using the mechanisms Current SPS.

[0096] In one example, a WTRU may send the desired initial subframe (i.e., offset) for the SPS resources to the eNB to allow the eNB to activate the allocation/reallocation of SPS resources so that it is generation-aligned. CAM message. Specifically, a WTRU may send a time offset, for example, in the form of a system frame number (SFN) and/or subframe index, to the eNB that indicates the time at which it is expected to (start) have a resource of available SPS. The time offset (or "offset") can also be sent to the eNB implicitly, assuming that the SFN and/or the subframe is a predefined fixed number of subframes after transmission of a signal by the WTRU to the eNB.

[0097] Alternatively, the WTRU may instruct the eNB to delay or change the current displacement of the SPS by a certain period of time. For example, the WTRU may already be configured with an SPS configuration and a specific time offset or starting point for resources for that SPS configuration. The WTRU may instruct the eNB to shift, delay, advance the timing or starting point for that SPS configuration by a certain number of subframes relative to the current timing of the resources.

[0098] The WTRU can be configured with multiple timing options. For example, to reduce signaling associated with the offset change required by the eNB, the WTRU may be additionally configured with a set of timing offsets possible by the eNB, where a specific timing offset may be active at a given time, and the WTRU may request an alternate timing offset in an offset change requested message.

[0099] The WTRU can receive multiple possible offsets in an RRC message by configuring the SPS. These offsets can be indicated as an offset from a specific subframe/SFN, whether defined or provided in the same configuration, or as an offset from the initial resource configuration in the PDCCH message indicated by the SPS C-RNTI that can allocate the SPS resources to the configuration for the first time.

[00100] The WTRU can also receive, or be associated with, an index for each of the possible displacements in the RRC message.

[00101] When sending the requested offset change to the eNB, the WTRU may indicate the desired offset it wishes to use by indicating the index associated with one of the configured offsets.

[00102] Figure 3A reveals the use of a 4-bit range value indicator 300. With four bits, a value 302 can represent a range size. Up to 16 different ranges are shown in this example, assuming four bits. Here, the value 0000 304 corresponds to a minimum interval of 100 milliseconds 306. The maximum value shown, 1001 308, corresponds to a long interval of 1 second 310. Figure 3B illustrates an exemplary MAC control element 320 comprised of the indicator 4-bit range 322 and a 10-bit system frame number 324 used as an offset. The 10-bit system frame number can be made smaller by using an SFN offset from a current SFN instead of 0.

[00103] Different types of information can be provided in the request for displacement or displacement change message. The request for offset or change in offset may contain any of: SFN and/or SPS subframe offset (i.e. timing of one of the SPS resources), required time offset (positive or negative, and potentially in terms of frames, subframes, or some unit of subframes, such as scheduling periods) of the SPS resource pattern relative to the current timing pattern, index that identifies one of several possible timing offsets for the SPS resource pattern (potentially configured by the eNB or default), and identification of the SPS process (if multiple are configured) for which the timing needs to be changed.

[00104] An SFN and/or subframe offset of the SPS, for example, a timing of one of the SPS resources, may be represented by any of the following: the absolute SFN and subframe of the first SPS resource with the other resources separated for the configured SPS period, the offset from a predefined fixed subframe (e.g., SFN 0 (mod x) and subframe 0), the offset from the start of the scheduling period associated with a sidelink resource set, any/or the offset from the original transmission by the eNB of PDCCH with SPS C-RNTI, PDCCH with DCI format 5, or any similar PDCCH message used by the eNB to initiate SPS resource allocation after its configuration.

[00105] With respect to an index that identifies one of several possible timing offsets for the SPS resource pattern, potentially configured by the eNB, or predetermined, the eNB may send, in the SPS configuration, a set of indexed allowable offsets, and the WTRU can provide the offset change by providing the index that corresponds to the desired offset.

[00106] Regarding an identification of the SPS process (if multiple are configured) for which the timing needs to be changed, this identification can be done by sending an index that references the index provided by the eNB in the configuration of the multiple SPSs. This identification can also be done by sending an index that corresponds to the order of SPS grants relative to a specific frame/subframe combination (e.g. SFN x mod y, subframe 0).

[00107] Such information related to a request for displacement or change in displacement is additionally called displacement change information.

[00108] The WTRU may send a request for displacement or change in displacement using one or more of the following. An offset request may be provided in an RRC message containing the offset change information, which may occur following the RRCRadioResourceConfiguration message that configures the SPS in the WTRU, or at any time after connecting the WTRU to the eNB. An offset request may be provided in a MAC control element (CE) containing the offset change information.

[00109] A displacement request may be provided in a BSR containing the displacement change information. Specifically, a WTRU may trigger a BSR when it determines that the timing of SPS allocations requires a change. The BRS can be a sidelink BSR in the case where the SPS resources and transmissions are on PC5 instead of UL. The offset change information may be included in the BSR or the sidelink BSR.

[00110] For example, the sidelink BSR or BRS may include, in a new field, the SFN and subframe, time shift, or SPS configuration index for the SPS configuration. This information may be further associated with a group of logical channels for which the WTRU may use said SPS configuration to transmit data. The information may be in the form of one or more additional fields for the buffer size associated with the logical channel group.

[00111] The BSR or side link BSR may include the SFN, subframe, the timing shift may be sent in place of the buffer size for a specific logical channel group. The WTRU may use a special target index field, a logical channel group, or a combination of the two, to indicate that the corresponding buffer size fields indicate SPS timing information instead.

[00112] The BRS or sidelink BRS may contain a special flag that indicates that a change in the SPS timing is requested as a result of the BRS transmission. The requested new timing of the SPS configuration can be indicated by the occurrence of the time at which the WTRU sends the BSR. For example, the WTRU may indicate that the new SPS timing offset corresponds to a number of subframes (possibly 0) following the subframe in which the BRS was transmitted.

[00113] The BSR or side-link BSR may contain the index that is associated with one of the predefined or permitted timing offsets for the SPS standard.

[00114] A shift request may be provided in a physical layer (PHY) message, such as, but not limited to, a scheduling request (SR), a scheduling channel, physical uplink control channel (PUCCH), a sounding reference signal (SRS), or a random access procedure (RACH). For example, a special dedicated SR resource can be allocated in the WTRU to send the desired SPS offset. Different SRs can be configured in the case where multiple SPS configurations are present. The actual SFN and offset to the start of the SPS resource could be understood as occurring a certain number of subframes after the subframe in which the special SR was transmitted by the WTRU, for example, in the same subframe, or after a predefined number of subframes , known for both WTRU and eNB.

[00115] The WTRU may transmit the requested offset message at any time during operation to change the offset of the current SPS resources. For example, as a result of one of the transitions shown in the timeline shown in Figure 2, which may change the offset between the SPS and the CAM, but where the intervals for both remain the same, the WTRU may transmit the offset message requested for eNB. More detailed triggers for the WTRU transmitting the requested offset message are further described below.

[00116] The WTRU receives a timing change confirmation from the eNB. In particular, after transmission of the requested offset message, the WTRU may receive a timing change acknowledgment from the eNB that may provide the new timing for the SPS configuration. This acknowledgment can be received using any of the following: PDCCH message, MAC CE message, or RRC message.

[00117] With regard to the PDCCH message, the timing change confirmation may be indicated with an SPS C-RNTI that identifies the SPS configuration as well as the new timing of the SPS resources. In the case of multiple SPS configurations, each SPS configuration can be represented by a separate SPS C-RNTI.

[00118] Figure 4 is an illustration of an exemplary MAC header 402 and MAC payload 404 comprising a plurality of MAC CE messages 406, 408. With respect to one or more of the MAC CE messages 406, 408, confirmation of the timing change can be indicated by the message containing the new timing, using, for example, an SFN and/or subframe offset, and identification of the SPS configuration, denoted here by the I2 interval. Subframe number 412 may be included in a MAC CE. The MAC payload 404 may additionally comprise one or more MAC SDU 414 and padding 416.

[00119] In relation to the RRC message, confirmation of the timing change can be indicated by the message containing the new timing (SFN and/or subframe shift) and identification of the SPS configuration.

[00120] The WTRU may apply/assume/infer the new resource timing upon receipt of the timing change confirmation from the eNB. The WTRU may further assume that the new timing is the one provided in the requested offset message (if the eNB does not provide a timing), or it may assume that the new timing is the timing provided in the eNB's timing change confirmation.

[00121] The WTRU can receive confirmation from the eNB using PDCCH or MAC CE. In this case, the WTRU can assume that the existing SPS RRC configuration is maintained and the timing change is simply applied using the information in the acknowledgment message. If the WTRU receives confirmation using RRC, the confirmation may also provide a new SPS configuration. The WTRU can then update its RRC configuration with the configuration provided in the acknowledgment message.

[00122] For example, after transmission of the requested offset message, the WTRU may receive a corresponding PDCCH using SPS C-RNTI to signal the change in SPS timing with the new offset. The WTRU may assume that the previous SPS timing (with the old offset) persists until it receives the PDCCH with the SPS C-RNTI (which must occur at the requested offset).

[00123] Figure 5 shows an example of a timing of messages 500 in accordance with the request for an offset or offset change in which the WTRU sends the requested offset or offset change to SPS. A vehicle or WTRU 502 may transmit an RRC connection request 506 to an eNB 502. The WTRU 502 may receive an RRC connection reset message 508 in response. The RRC connection reset message can include a spsConfig. CAM messages may be initiated by an application layer 510. The WTRU 502 may transmit a shift request message 512. The WTRU may receive, on the PDCCH, a C-RNTI from SPS 514. The WTRU may begin using the SPS resources at the requested offset 516. If a change in the CAM message offset 518 is determined by the application or otherwise, the WTRU 502 may transmit a request message from another offset 520. Upon receiving a PDCCH with a C-RNTI From SPS 522, the WTRU may begin using SPS resources on a newly requested shift 524.

[00124] WTRU triggers for sending an offset or offset change to the eNB are provided. Based on any of the information provided by the upper layers defined below (e.g., upper layer indication of message arrival timing, indication of a change in periodicity, indication of a timing change, message marked by higher layers, WTRU-based information which provides timing to the upper layers, and information related to vehicle dynamics changes) the WTRU may determine the need to send a displacement change to the eNB based on one or more of the following triggers.

[00125] A trigger may be when a timing change indication is received from upper layers.

[00126] A trigger may be indicated by the timing of message arrivals from higher layers, possibly associated with a specific PPPP or QCI, or of message arrival for a specific radio bearer, logical channel or the like, satisfies one of the following conditions.

[00127] A trigger may occur when the time between receipt of the upper layer indication and the next scheduled subsequent SPS resource exceeds a certain threshold Ta, or is less than a certain threshold Tb. The threshold Tb may correspond to an assumed processing latency as AS, and therefore the case of a time difference smaller than a threshold corresponds to having the processing latency required by the AS that exceeds this difference.

[00128] A trigger may incur when the time difference between the current and previous message arrival is different (e.g., by a configured amount) from previous Na intervals of the timing between message arrivals, or different (e.g. example, by a predefined configured quantity) from a determined periodicity of messages (this periodicity could be provided by the application layer or determined by the lower WTRU layers).

[00129] A trigger may occur when the message arrival timing becomes closer in time to another potential timing for the SPS resources (e.g., configured by the eNB).

[00130] A trigger may occur when the timing conditions described above occur consecutively a number of times (xNb).

[00131] If the WTRU sends information of the desired offset or timing to the SPS, the WTRU may compute this information based on one or more of the following.

[00132] The WTRU may select the timing offset to match any subframe that is at least Tc milliseconds after the CAM message timing (where Tc may be zero).

[00133] The WTRU may select the timing offset to match a subset of allowed subframes or allowed timing, which lies at least Td milliseconds after the CAM message timing, but minimizes the timing difference between the SPS resource and the CAM message timing. The subset of allowed subframes can be configured by the eNB. For example, the subset of allowed subframes may consist of the D2D subframes allowed for the side link, as defined by the TRPT or D2D subframe standard for the WTRU defined by the eNB, or by the WTRU transmission set on PC5. The WTRU can select one of the configured timing offsets, preconfigured by the eNB, that minimizes the timing difference between the SPS resource and the CAM message timing.

[00134] In another example, a WTRU may send an indication to change an SPS configuration to the network (e.g., an eNB) to change the period and/or scheduling interval of the SPS configuration. For example, a WTRU may send an indication to the eNB to request a change in the scheduling interval of the current SPS configuration. Specifically, the WTRU, upon triggering from higher layers (such as detecting the need to change the CAMs frequency due to a change in vehicle dynamics), can inform the eNB about the need to change the SPS configuration (e.g. the interval and/or scheduling offset). The WTRU may assume that the configuration change may take effect as a result of this indication. Alternatively, the WTRU may receive a message from the eNB with a new SPS configuration or confirm the configuration change requested by the WTRU. The configuration change can then take effect (i.e., the WTRU starts using the new configured SPS resources) in any of the following time cases: upon receipt of the indication by the eNB (e.g., based on the WTRU that receives an acknowledgment (ACK) from the eNB, for example, via a physical hybrid AEQ indicator channel (PHICH)); at some future time point indicated by WTRU; at some future time instant that is statically defined (i.e., in the WTRU specification) and which may be relative to the last SPS resource allocation, the time at which the eNB received the indication (e.g., as determined by the transmission and/or reception by WTRU of an ACK from the eNB through the PHICH), the time at which the WTRU transmitted the indication to the eNB, or a time instant explicitly provided in the indication; upon receipt by the WTRU of a new SPS configuration by the eNB; and/or upon receipt by WTRU of a confirmation that the indication has been received by the eNB. Confirmation that the indication has been received by the eNB may be sent via one or more of the following: one or more RRC messages, such as an SPS release followed by a new SPS configuration; a PDCCH grant using the SPS C-RNTI associated with the configuration; a PDCCH using a new C-RNTI or using a new downlink control information (DCI) format; and/or a new MAC CE.

[00135] Based on any of the information provided by the upper layers defined in section 4.1.5, the WTRU may determine the need to send an indication to change the SPS configuration. An indication to the eNB to change the SPS configuration may be sent by the WTRU as a result of a trigger.

[00136] A WTRU trigger for sending an SPS configuration change is provided. For example, based on any of the information provided by the upper layers defined below (e.g., upper layer indication of message arrival timing, indication of a change in periodicity, indication of a timing change, message marked by higher layers, information based on the WTRU that provides timing to the upper layers, and information related to vehicle dynamics changes) the WTRU may determine the need to send a displacement change to the eNB based on one or more of the following triggers.

[00137] A trigger may be incurred by a determination, by the AS, an adaptation layer described below, or an application layer, that the period of CAM messages has changed. This determination, whether performed by the AS or the adaptation layer, may follow the rules defined below for the adaptation layer to manage SPS for CAM messages described below, and may be based on information provided by higher layers.

[00138] A trigger may be incurred from the AS or from the V2X application layer running in the WTRU before, during, or after the generation of a CAM that is being sent with a CAM interval different from the previous interval.

[00139] The AS in the WTRU or the eNB itself may trigger an indication to the eNB upon determining that the CAM interval has changed (e.g., whether a CAM message was received with a shorter interval than the previous interval, or a CAM message was not received within the expected time relative to the last interval).

[00140] The number of future intervals in which the CAM interval is expected to remain the same (and its corresponding value) may trigger an indication to the eNB.

[00141] An indication that the CAM interval has changed to its maximum value (1 second) may trigger an indication to the eNB.

[00142] The WTRU may send, as part of the activated indication to the eNB, one or more of the following information: a new scheduling interval requested for the SPS configuration; a subframe in which SPS resources with the new scheduling interval should begin (i.e., offset); a resource size required for the SPS resources; an index that identifies one of several possible timing offsets for the SPS resource pattern; and/or identification of the SPS process (for example, if multiple processes are configured) for which the timing needs to be changed.

[00143] With regard to the new scheduling interval requested for the SPS configuration. The WTRU can provide the eNB with one of the possible SPS periodicities that were initially configured by the eNB. Alternatively, the WTRU can provide the eNB with any supported periodicity for SPS (predefined or standardized).

[00144] With respect to the index that identifies one of several possible timing offsets for the SPS resource pattern (potentially configured by the eNB, or predetermined), the eNB may send, in the SPS configuration, a set of indexed allowed offsets, and the WTRU can provide the offset change by providing the index that corresponds to the desired offset.

[00145] Regarding identification of the SPS process (e.g., if multiple are configured) for which the timing needs to be changed, this identification can be done by sending an index that references the index provided by the eNB in the configuration of the multiple SPSs . Alternatively, this identification can be done by sending an index that corresponds to the order of SPS grants relative to a specific frame/subframe combination (e.g. SFN x mod y, subframe 0).

[00146] The indication can be sent by the WTRU to the eNB using one of the following methods: a new MAC CE; a new special BSR that can maintain the information provided above; an SR potentially sent on a resource that is predefined to inform the eNB of this event, followed by transmission of the above information using a BRS or MAC CE; a PUCCH, potentially sent on a resource that is predefined to inform the eNB of this event; a new MAC CE, but sent in the SPS resource itself; a RACH or similar transmission by the WTRU performed on the next available RACH resource; or an RRC message.

[00147] After transmitting the indication to the eNB, the WTRU may continue to use the existing SPS configuration for transmitting CAMs until receiving confirmation from the eNB. Alternatively, if an acknowledgment is not expected, the WTRU may change the SPS resources to use CAM transmission for the new configuration in any of the start time cases described above (i.e., the SPS implicitly changes based on the sending indication).

[00148] Figure 6 is a message flow diagram for an exemplary embodiment. In Figure 6, the WTRU Access Stratum may receive a message from the application layer 602 when the trigger condition (1) or (2) described below occurs. According to condition (1), a time elapsed since the last CAM generation is equal to or greater than T_GenCam_Dcc and one of the following dynamics-related conditions is given: the absolute difference between the current bearing of the source ITS-S and the bearing included in the CAM previously transmitted by the originating ITS-S exceeds 4°; the distance between the current position of the source ITS-S and the position included in the CAM previously transmitted by the source ITS-S exceeds 4 m; or the absolute difference between the current speed of the source ITS-S and the speed included in the CAM previously transmitted by the source ITS-S exceeds 0.5 m/s. Here, T_GenCam_Dcc provides the minimum time interval between two consecutive CAM generations in order to reduce the CAM generation according to the Decentralized Congestion Control (DCC) channel usage requirements. According to condition (2), a time elapsed since the last CAM generation is equal to or greater than T_GenCam and equal to or greater than T_GenCam_Dcc. Here, T_GenCam represents current valid upper limit of CAM generation interval.

[00149] A trigger of the application or entity that manages vehicle dynamics that the speed, direction or position has changed from a state in which trigger condition (1) above is valid to a state in which condition (1) is not valid.

[00150] The WTRU access stratum, upon determining that the SPS range needs to change from application layer I1 to range I2 (e.g., upon receipt of an application layer message when the trigger condition ( 1) or (2) occurs), it may send a MAC CE 604 to the eNB containing I2, as well as the subframe in which the RAN expects to be able to send the next CAM message (i.e., the new offset timing). . Subsequently, the WTRU can be scheduled with dynamic resources, or can send an SR to the trigger schedule of these dynamic resources, and can send any pending CAM messages using the dynamically scheduled resources. At some point after referral using the MAC CE, the WTRU access stratum can be scheduled on the PDCCH using the SPS C-RNTI. Upon receipt of this schedule on the PDCCH, the WTRU may assume that the SPS configuration is changed, and the schedule interval is I2 for that SPS. Consequently, the WTRU may also change the corresponding configuration element in RRC.

[00151] The Figure. 7 illustrates an exemplary embodiment that can shorten the time required for an eNB to signal the SPS change. The WTRU access layer may receive a message from the application layer 702 when a trigger condition occurs, for example, when condition (1) or (2) described above occurs. The WTRU access stratum, upon determining that the SPS range needs to change from the I1 range to the I2 range 704, may send a new special BSR 706 that contains the I2 range and the subframe in which the access stratum expects to be able to send the next CAM message (i.e. new timing offset). Upon receipt of the ACK associated with the MAC protocol data unit (PDU) on which the special BSR is transmitted, the WTRU may assume that the SPS configuration has been changed in accordance with the request. Consequently, the WTRU may also change the corresponding configuration element in RRC.

[00152] In another exemplary embodiment, the WTRU access layer may receive a message from the application layer or higher layers indicating that the periodicity of the CAM messages has been changed, for example, from 1 second to 200 ms. The WTRU access stratum, upon receipt of this information, may send a MAC CE containing the identification of the SPS configuration whose period must be changed, as well as the new period required for the SPS configuration. The WTRU may continue to assume the current SPS configuration until it receives a new SPS configuration (e.g., by RRC messages) from the eNB. The WTRU may cancel the current SPS configuration upon receipt of the new SPS configuration and only activate the new SPS configuration upon receipt of a PDCCH message (e.g., DCI format 5 for side link) encoded with C-RNTI of SPS associated with the new SPS configuration.

[00153] The WTRU may also send an indication, message and/or notification to release specific resources (e.g., a subset of SPS resources). For example, a WTRU may send a message to the eNB to release a specific set of SPS resources associated with an SPS configuration, but not release the entire configuration. For example, the WTRU may indicate that it does not need (does not plan to use) the SPS resources associated with the upcoming SPS X scheduling slots. This would allow the eNB to schedule these resources for other WTRUs. After the X scheduling intervals, the WTRU can then assume that it again has access to SPS resources according to the existing SPS configuration.

[00154] The WTRU may send the indication to release specific resources using one of the following methods: a new MAC CE; a new special BSR that can maintain the information provided above; an SR potentially sent on a resource that is predefined to inform the eNB of this event, followed by transmission of the above information using a BRS or MAC CE; a PUCCH, potentially sent on a resource that is predefined to inform the eNB of this event; a new MAC CE, but sent in the SPS resource itself; a RACH or similar transmission by the WTRU performed on the next available RACH resource; or an RRC message.

[00155] Various SPS configurations are provided. In particular, multiple SPS settings and activation/deactivation settings are provided, and the activation and deactivation thereof can be performed dynamically on a real-time basis according to trigger conditions and events. For example, a WTRU may be configured with multiple SPS configurations, but may only have one configuration active at any given time. A WTRU can then request a change (cycle) between a configuration and one or more other configurations, deactivating the current active configuration and activating another configuration.

[00156] The WTRU may receive the various configurations together with the RRC connection reconfiguration message from the eNB. The WTRU can receive the active configuration of the provided settings from the eNB. Alternatively, it may be necessary for the WTRU to assume that neither configuration is active and instead indicate to the eNB at a later time which configuration to activate. The WTRU may send, in an SPS enable/disable message, to the eNB an identifier associated with the SPS configuration to activate or deactivate the corresponding SPS configuration.

[00157] The WTRU may send an activation/deactivation message or indicator configuration using one of the following methods: a new MAC CE; a new special BSR that indicates the configuration for activation/deactivation; an SR, potentially sent on a resource that is predefined to inform the eNB of this event; a PUCCH, potentially sent on a resource that is predefined to inform the eNB of this event, and potentially where the specific PUCCH resource selected by the WTRU may also indicate the SPS configuration for activation or deactivation; a RACH or similar transmission by the WTRU performed on the next available RACH resource; an RRC message; a message such as SRS, where the location of the SRS resource can potentially also indicate the SPS configuration for activation or deactivation. Furthermore, the position of the SR can also indicate which SPS setting to activate/deactivate.

[00158] A WTRU may consider the requested configuration activated upon transmission of the activation/deactivation message. Alternatively, the WTRU may consider the requested configuration activated upon confirmation by the eNB, either through: a hybrid automatic repeat (HARQ) request to the MAC PDU carrying the MAC CE, an explicit RRC message, or a layer message. PHY, such as the PDCCH message (for example, PDCCH with C-RNTI of SPS).

[00159] In one embodiment, the WTRU may send a new MAC CE to activate one SPS configuration while deactivating the other configurations. Activation may occur in the subframe in which the WTRU receives a C-RNTI from the eNB.

[00160] A WTRU can potentially use the above mechanisms to disable all SPS configurations based on higher layer triggers. For example, a WTRU may receive (e.g., from the adaptation layer) an indication not to use SPS.

[00161] Triggers for requesting a change to the SPS configuration include: an application layer, an adaptation layer, or higher layers indicate when the traffic period has changed (e.g., from 1 second to 100 ms or vice versa); application layer, adaptation layer, or higher layers indicate that the timing (offset) has changed, what the new offset is, and that the timing has changed by a certain amount (e.g., greater than a threshold); and WTRU determines that one configuration may be better than another based on information provided by the application layer, adaptation layer, or higher layers.

[00162] Figure 8 illustrates a number of application-level trigger events in relation to V2X communications. For example, an autonomous mode change may be detected when a vehicle switches from a human driver to an electronic drive control 802. It may be desirable for a WTRU to be allocated a higher (or lower) SPS periodicity, such that an autonomous vehicle can be allocated more system bandwidth to consequently transmit/receive information. The same may be true with a driver indication below 18 804. Another exemplary trigger event includes a system capability change that may be related to a vehicle's firmware updates software or WTRU. In some cases, software updates may be frequent. Adding new software or applications may also cause a change in system capacity.

[00163] Logical channel prioritization applied to the SPS grant is provided. In particular, a WTRU, when transmitting using a lease associated with a given SPS configuration, may select the logical channel data to be transmitted using that lease. Selection of logical channel data to be transmitted may be based on the use of a combination of the following criteria which may be prioritized in any order: transmit data with the highest priority, based on PPPP; transmit data with decreasing PPPP priority; transmit data whose periodicity corresponds to, is less than or greater than the periodicity of the SPS configuration associated with the concession; transmitting data whose size corresponds to, is less than, or greater than the grant size of the SPS configuration associated with the grant; transmit data based on a configured mapping between the data/service or higher layer logical channel, and the SPS configuration; defer data transmission until a grant for the associated SPS configuration is received; and length of time until the next grant associated with a specific SPS configuration. This selection can apply whether the WTRU has multiple SPS configurations active simultaneously or a single SPS configuration active.

[00164] In one example, a WTRU may select the SPS resource to use for transmitting data from higher layers based on the SPS configuration of the eNB. A WTRU may receive an SPS configuration that is associated with one or more logical channels, logical channel groups, radio bearers, PPPP, QCI, or the like.

[00165] The WTRU may only transmit data from one or more logical channels, or the like, using the SPS grants for the SPS configuration associated with the logical channels.

[00166] Alternatively, the WTRU may first transmit all data from the associated logical channels and then transmit any remaining data (potentially from other logical channels not associated with the SPS configuration) if the lease allows transmission of additional data, but all data in the buffers for the associated logical channels can be transmitted using the grant.

[00167] Additionally, the WTRU may first transmit all data with priority (e.g., PPPP or logical channel group (LCG) (i.e., LCP)) that is greater than the configured logical channel associated with the SPS configuration before from transmitting any data on the configured logical channel. Alternatively, the WTRU may first consider all data associated with an SPS configuration before considering data with higher priority (e.g., PPPP or LCG priority).

[00168] In another example, a WTRU may determine which SPS resource to use based on the configured periodicity and/or allocation size of the SPS resource, as well as application layer information. In this case, the WTRU can determine the required transmission interval for a specific application layer packet based on the application layer information included in the packet. This information could be in the form of a parameter such as QCI that indicates the periodicity or timing requirements attached to the packet. This may also be provided to the WTRU in the form of a PPPP, where specific PPPPs may be used to indicate data with a specific transmission period (e.g. CAM traffic).

[00169] The WTRU, when selecting data to be transmitted on an SPS resource, may identify the periodicity associated with the SPS configuration associated with the specific SPS resource; selecting upper layer PDUs that require a corresponding periodicity for multiplexing into the MAC PDU for transmission; if all data of the corresponding periodicity has been included, select upper layer PDUs that require lower periodicity for multiplexing into the MAC PDU for transmission; and, if all of the above have been included, select upper layer PDUs for any periodicity, or select upper layer PDUs not associated with any specific periodicity or timing requirement for multiplexing into the MAC PDU for transmission.

[00170] In another example, selection of a WTRU may defer selection of an RLC PDU for transmission until the grant occurs from the associated SPS configuration (configured or based on mapping determined by WTRU) and select that PDU only when this grant is received. In this case, a WTRU may, when selecting RLC PDUs for transmission from a MAC PDU, avoid selecting the RLC PDU from a logical channel (regardless of its priority) and select an RLC PDU from the highest logical channel (in priority) for transmission. The WTRU may also avoid PDU selection under the condition that the time until the arrival of the next grant for the associated SPS configuration is less than some pre-configured threshold. Otherwise, the WTRU can be configured to transmit the packet using the legacy mechanism (for example, using the current lease through the legacy mechanism to request a lease).

[00171] Management of concurrently occurring SPS grants is provided. In particular, a WTRU may be configured with multiple SPS configurations active such that grants from the different SPS configurations occur simultaneously. This may consist of grants that occur in the same UL subframe (for UL SPS transmission) or in the same scheduling period (for example, for sidelink (SL) SPS transmission). SL SPS refers to an SPS configured for device-to-device (D2D) communication.

[00172] In an example, a WTRU configured with concurrently occurring SPS grants may be required or expected to transmit using only one of the grants. This may be the case, for example, if the eNB assumes that the WTRU will use only one of the configured leases, and allocates the UL resources to other WTRUs. The grant to be used by WTRU may be selected according to any of the following criteria.

[00173] The concession that has the largest allocated resource, for example in terms of resource blocks, can be selected. The grant for which the allocated resource size is closest to the size of the data to be transmitted by the WTRU, for example as transmitted in the BSR to the WTRU, can be selected. Potentially, in this scenario, the grant must be additionally greater than or equal to the amount of data to be transmitted by the WTRU, or indicated by the WTRU in the BSR. The grant with the best channel properties (e.g. based on measurements made by WTRU or eNB) can be selected. The grant for which the WTRU has detected, for example, through detection, that has the least interference from other transmitting WTRUs or has the least overlap (in terms of resources) with the transmission resources selected by another WTRU for the same period of Scheduling can be selected.

[00174] In this example, a WTRU may further use the rules for logical channel prioritization (LCP) discussed above to select data to transmit on the configured and selected grant.

[00175] In another example, a WTRU configured with concurrently occurring SPS leases may be required or expected to transmit on all leases in the given scheduling period or UL subframe. In this case, the WTRU may additionally use the rules for LCP discussed above to select data to transmit in the concurrently occurring grants. The WTRU may also perform the LCP in this case while following any of the rules below.

[00176] For example, the WTRU may assume that the sum of the grant sizes of the simultaneously occurring grants is available for transmission of a MAC PDU, and perform LCP given the sum of the grant sizes. Additionally or alternatively, the WTRU may select the lease to use to transmit an RLC PDU so that the RLC PDU does not need to be segmented. Additionally or alternatively, WTRU may consider each grant separately and apply the previously mentioned rules for LPC. For example, the WTRU may select only one RLC SDU from a logical channel associated with an SPS configuration for transmission on that configured SPS grant.

[00177] A WTRU may indicate when not to use a specific lease so that the eNB can relocate under the condition of multiple configured SPS leases. For example, when the WTRU is configured with multiple leases and uses only a subset (e.g., one) of the SPS leases configured in a specific subframe, the WTRU can be configured to indicate to the eNB that the lease will not be used for the eNB so that the eNB can reallocate the resources to another device. In one example, the WTRU may first determine which grant it will use and then signal to the eNB (e.g., using a physical channel or another channel) which SPS grant (e.g., via an index) it will hold. using. The eNB can determine from this information which SPS grant or grants are not used so that the eNB can allocate the resources to another device). This approach is advantageous when multiple SPS leases are configured and the WTRU uses only one of the SPS leases. In another example, the WTRU may be configured with two SPS grants, and the WTRU may indicate the SPS grant index of the SPS grant that is not intended to be used (for example, the canceled SPS grant). To be effective, the indication may require that it be transmitted at a specific time before the actual granting of SPS occurs.

[00178] Higher layer assistance for triggering SPS scheduling assistance is provided. For example, as already noted above, the WTRU may receive information from higher layers (e.g., upper layer indication of message arrival timing, indication of a change in periodicity, indication of timing change, message marked by higher layers, information based on the WTRU that provides timing to the upper layers and information related to changes in vehicle dynamics). The WTRU can determine the need to send an offset or periodicity change to the eNB based on information from higher layers. This may correspond to information from the application layer, or from an adaptation layer whose modalities are described below.

[00179] Information received from upper layers is further described. The upper layer information may include upper layer indication of message arrival timing. For example, the WTRU may receive, from the application layer or higher layers, an indication of the arrival of a CAM message. This indication can be received each time the upper layer sends this message to the AS.

[00180] The upper layer information may include an indication of a change in periodicity. For example, the WTRU may receive, from the application layer or higher layers, an indication of a change in the periodicity or interval for the CAM messages, as well as the new CAM message period.

[00181] The upper layer information may include a timing change indication. For example, the WTRU may receive, from the application layer or higher layers, an indication that a change in the timing of CAM messages (or messages requiring SPS alignment) has occurred as determined by the higher layers. This indication may also contain the absolute time of the new timing of messages transmitted to the lower layers (for example, the transmission time of an instance of the periodic message flow). Alternatively, the indication may be sent to coincide with the transmission of a message with the new timing (e.g., the timing of the indication represents the timing of the message).

[00182] The upper layer information may include a message marked by higher layers. For example, a CAM message, or message that requires SPS alignment, may be marked or indicated as such by the upper layers. For example, the message can be marked with a Specific Packet Data Convergence. The Service Data Unit (SDU) type of Protocol (PDCP) that identifies the message as a message requires SPS alignment. The message may contain a specific PPPP value (per packet priority) that indicates that this message requires SPS alignment. Additionally, this message may be received with other QoS-related information, such as QCI or similar information, where a specific QCI value may represent the need for SPS alignment and/or timing-related requirements, e.g., a value specific to the packet delay budget (PDB) that represents a 100 ms latency requirement and/or periodic data.

[00183] A WTRU can further be configured by the eNB so that all traffic or messages that require alignment with SPS are assigned to a specific logical channel, radio bearer or the like. This restriction can be based on application layer information such as QCI or PPPP. For example, the WTRU may assign all messages to a specific PPPP or QCI that indicates the need for SPS alignment for a specific logical channel.

[00184] The upper layer may include WTRU-based information that provides timing to higher layers. For example, a WTRU, potentially upon SPS configuration by the eNB, can provide the upper layers with the configured SPS timing in any of the following ways: The WTRU can provide the upper layers or the application layer with the absolute timing instance the occurrence of one of the SPS resources; and/or the WTRU may provide, in some or each of the occurrences of an SPS resource, an indication or signal of the presence of that resource in the AS. The application layer may additionally provide an indication to the lower layers that a change in the timing of the SPS as currently configured is required, and the additional information required to create the offset change message for the eNB (e.g., the timing change of SPS resources or resource pattern required to meet current application message generation).

[00185] Upper layer information may include information related to changes in vehicle dynamics. For example, the AS may receive information relating to changes in vehicle dynamics such as: an indication of a change in speed, heading or acceleration that exceeds the event trigger thresholds defined in conditions (1) and (2) described herein; an indication that either the trigger condition (1) or (2) described above occurs; and/or an indication that the speed, direction, or position has changed from a state in which the trigger condition (1) is valid to a state in which it is not valid.

[00186] As described above, the CAM size may change periodically depending on whether the V2X application wants to transmit a high-frequency container, a low-frequency container, or other special containers. As a result, a fixed SPS allocation is not ideal for providing the resources needed to transmit the CAM. Furthermore, the eNB would need to be aware of the SPS allocation size required for the CAM message, but this information is only present in the WTRU (e.g. in the vehicles).

[00187] Consequently, the size of the SPS message can be configured via an application layer. For example, the V2X application in the WRTU may provide the size information to a corresponding application in the network or eNB through application layer signaling, for example, as a CA basic service message. Size information that can be sent via application layer messages can include: container sizes; a pattern in which a high-frequency container, a low-frequency container, or special containers are sent; and/or any dynamic changes in patterns that occur during operation, for example, when a WTRU V2X decides to send the low-frequency container more frequently than necessary.

[00188] The application layer in the network or eNB may provide this information to the eNB to define an appropriate SPS allocation size and provide any additional dynamic scheduling for time instances where the allocated SPS size needs to be increased, e.g. Additional containers can be included in the CAM message.

[00189] In another example, the SPS message size may be associated with a Quality of Service (QOS) Class Identifier (QCI) for a logical channel. For example, the required SPS allocation size, and potentially the pattern of CAM message changes can be coupled with the QCI associated with the V2X logical channel. When the V2X logical channel is established, the eNB may know or determine (for example, based on predefined mapping, or from information obtained from a V2X application service in the network), the required size of the SPS allocation to be able to maintain CAM messages.

[00190] A WTRU may transmit a synchronization message to the eNB to indicate the timing and transmission frequency of the high-frequency container and the low-frequency container, so that the WTRU can know or determine the time instances at which SPS allocations need to be increased or replaced with a dynamic allocation. For example, the message may indicate an SFN and a subframe corresponding to the transmission of a low-frequency container, and which low-frequency containers are transmitted every X CAM messages.

[00191] In another example, allocation size changes may be accumulated across SPS transmissions. For example, a WTRU may send a message indicating that the next following CAM message will have an increased size (e.g., that it contains a low-frequency container) and potentially also the increment in size compared to the current SPS allocation. This message could be accumulated as a MAC CE in the current CAM message transmission. The advantage of this solution compared to dynamic scheduling is that the WTRU does not need to send a separate SR or BSR when the larger CAM message arrives, and thus can avoid additional delays (and also additional signaling) associated with the SR/BSR method.

[00192] In another example, the SPS allocation size may be increased periodically. For example, the WTRU can be configured with an SPS allocation that periodically increases beyond the resource allocation specified in the PDCCH with SPS C-RNTI. The increase in resource allocation can be fixed (e.g. always 2 times the SPS allocation), or it can be determined by the WTRU from the signaling received from the eNB. For example, the SPS configuration itself in the RRC signaling may contain the details of the increase in resource allocation for the SPS, the frequency with which it occurs, and the relationship of the additional resource elements to the regular SPS allocation. In another example, the PDCCH with SPS C-RNTI itself, potentially using a new DCI, can indicate the amount of increase in SPS allocation, and how often this increase occurs, along with the time-frequency location of the increased allocation.

[00193] An adaptation layer for managing SPS for CAM messages is provided. The V2X application that manages the construction and transmission of CAM messages (and other V2X messages like Basic Security Message (BSM) or Decentralized Environmental Notification Message (DENM)) can interface with different types of transports like LTE (e.g. side link and Uu), as well as dedicated short-range communications (DSRC). Since latency requirements need to be met regardless of the transport used, it may be better from an implementation point of view to create an adaptation layer that allows the V2X application to interface with the specific transport while satisfying the latency requirements of the V2X message without the need to add transport layer specific information in the V2X application itself.

[00194] The adaptation layer for V2X to LTE can provide the following functionality in relation to SPS: enabling/disabling SPS based on whether vehicle dynamics justify its use; and providing information to the AS to determine the period and timing of SPS traffic. It should be noted that the functionality described for the adaptation layer may be within the AS or the application layer as well, depending on the specific implementation of the WTRU or the application layer residing in the WTRU.

[00195] Regarding enabling/disabling SPS for CAM traffic, the adaptation layer may send an indication to lower layers to indicate when it may be advantageous to configure SPS (e.g., when CAM traffic is relatively periodic). A WTRU may additionally transmit this indication to the eNB to enable/disable the use of SPS (as described above).

[00196] The adaptation layer can determine the use of SPS (i.e., enabling/disabling it) based on vehicle dynamics or other information provided by the application layer, such as: whether the vehicle speed is above a certain threshold (indicating highway driving), the proximity of the vehicles to other vehicles traveling in the same or opposite direction, information from the vehicle's global positioning system (GPS), the type of road on which the WTRU is traveling moving and/or traffic information, such as the number of vehicles in the area surrounding the vehicle, or the direction of travel of the vehicle.

[00197] Based on the above information, the adaptation layer can determine the periodicity level of the CAM messages generated by the V2X application layer, and can send an indication to the lower layers in the WTRU as to whether the SPS should be configured or not.

[00198] In another example, the adaptation layer, when performing the same determination defined above, can provide indication to a similar adaptation layer residing in the network. This adaptation layer in the network can provide this information (e.g., for a specific WTRU) directly to the eNB.

[00199] To determine the periodicity of SPS, the LTE adaptation layer may receive, from the application layer, the instantaneous speed of the vehicle. This speed can be provided to the adaptation layer periodically. Alternatively, the LTE adaptation layer may receive a new speed or trigger when a change in speed exceeding a certain threshold has occurred. The adaptation layer can determine the required SPS periodicity and inform the AS layers about the required periodicity based on a simple lookup table. For example, a periodicity of x1 can be set when the velocity is in the range y11 to y12, a periodicity of x2 can be set when the velocity is in the range y21 to y22, and so on.

[00200] In order to determine the SPS timing the LTE adaptation layer may receive, from the application layer, triggers that correspond to a CAM generation (i.e., trigger conditions (1) and (2) ) described above. Namely: the absolute difference in heading exceeds a threshold (e.g. 4 degrees), the distance exceeds a threshold (e.g. 4m) and/or a change in speed exceeds a threshold (e.g. 0.5 m/s ). These triggers can be received from the application layer using separate signaling (e.g., side information), or they can be included in the CAM message itself.

[00201] The LTE adaptation layer may be provided, by the AS, with frame and subframe timing based on any of the following methods: a signal or event sent for each subframe or interval or subframes, a frame and subframe counter maintained by the AS and readable/accessible by the LTE adaptation layer and/or an AS-provided function that converts the absolute (maintained in the WTRU) to a frame and subframe time. The LTE adaptation layer can maintain the exact timing associated with the current SPS configuration based on your previous SPS enablement on the AS. Accurate timing can be maintained based on absolute timing or based on frame/subframe timing. Alternatively, the LTE adaptation layer may receive from the AS, the absolute time of the currently configured SPS configuration (e.g., as configured by the eNB), and the currently configured periodicity. Based on this information, the LTE adaptation layer may be able to calculate the timing of each SPS resource in time.

[00202] Compensation for AS delay is provided. For example, the adaptation layer can provide the AS with the desired SPS timing. This timing may include compensation for AS delay (e.g., from the time the CAM message is generated to the time it is ready for over-the-air transmission). This compensation factor can be provided dynamically by the AS. This compensation factor can be determined by the LTE adaptation layer using a static value that is related to the required delay. For example, given a maximum delay of 100 ms, the LTE adaptation layer can be configured with a compensation factor of 10 ms to account for AS delay. This compensation factor may be determined by the LTE adaptation layer based on the capacity of the WTRU, network, etc., which may be provided on a subscriber identification module (SIM) card, WTRU storage/configuration, provided by the AS after network connection and/or provided as part of application layer or NAS layer signaling over the network.

[00203] Although the features and elements are described above in specific combinations, one skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. Furthermore, the methods of the present invention described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired and/or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard drives and removable disks, magneto-optical media, and optical media such as CD-ROM disks and/or digital versatile discs (DVDs). A processor in association with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC and/or any host computer.

Claims (17)

1. Method executed by a wireless transmission/reception unit (WTRU), the method being characterized by the fact that it comprises: transmitting, from the WTRU to an evolved node B (eNB), a message, the message indicating a periodicity of traffic, a transport block size, and a timing offset with respect to subframe number 0 of system frame number 0; receiving from the eNB, via the WTRU, in response to the transmitted message, an index identifying a sidelink semi-persistent scheduling configuration (SPS) and an indication of one or more parameters associated with the sidelink SPS configuration; and transmitting data on a sidelink channel, through the WTRU, in accordance with the SPS configuration, wherein the sidelink SPS configuration is a sidelink SPS configuration of a plurality of sidelink SPS configurations associated with the WTRU. 2. Method according to claim 1, characterized by the fact that the received SPS configuration corresponds to a PC5 interface. 3. The method of claim 1, wherein the SPS configuration is received via a physical downlink control channel (PDCCH). 4. Method according to claim 1, characterized by the fact that the message includes an index of an SPS configuration. 5. Method, according to claim 1, characterized by the fact that it additionally comprises: transmitting the data, according to a logical channel priority (LCP). 6. The method of claim 1, wherein the transmitted message includes a PPPP information element. 7. Wireless transmission/reception unit (WTRU), characterized by the fact that it comprises: a transmitter configured to transmit, from the WTRU to an evolved node B (eNB), a message, wherein the message indicates a traffic periodicity, a transport block size, and a timing offset with respect to subframe number 0 of system frame number 0; a receiver configured to receive from the eNB, via the WTRU, in response to the transmitted message, an index identifying a link-side semi-persistent scheduling (SPS) configuration and an indication of one or more parameters associated with the link-side SPS configuration side; and the transmitter is further configured to transmit data on a sidelink channel in accordance with the SPS configuration, wherein the sidelink SPS configuration is a sidelink SPS configuration of a plurality of sidelink SPS configurations side associated with the WTRU. 8. WTRU, according to claim 7, characterized by the fact that the received SPS configuration corresponds to a PC5 interface. 9. WTRU, according to claim 7, characterized by the fact that the SPS configuration is received through a physical downlink control channel (PDCCH). 10. WTRU, according to claim 7, characterized by the fact that the message includes an index of an SPS configuration. 11. WTRU, according to claim 7, characterized by the fact that the transmitter is additionally configured to transmit the data, according to a logical channel priority (LCP). 12. WTRU, according to claim 7, characterized by the fact that the message includes a PPPP information element. 13. Method executed by an evolved node B (eNB), the method being characterized by the fact that it comprises: receiving, from a WTRU, a message, with the message indicating a periodicity, a transport block size, and an offset of timing with respect to subframe number 0 of system frame number 0; and transmitting to the WTRU, in response to the received message, an index identifying a sidelink semi-persistent scheduling (SPS) configuration and an indication of one or more parameters associated with the sidelink SPS configuration; wherein the sidelink SPS configuration is a sidelink SPS configuration of a plurality of sidelink SPS configurations associated with the WTRU. 14. Method according to claim 13, characterized by the fact that the SPS configuration corresponds to a PC5 interface. 15. The method of claim 13, wherein the SPS configuration is received via a physical downlink control channel (PDCCH). 16. The method of claim 13, wherein the message includes an index of an SPS configuration. 17. The method of claim 13, wherein the message includes a PPPP information element.