WO2020006733A1

WO2020006733A1 - Methods and apparatus related to forming and/or managing a group of devices

Info

Publication number: WO2020006733A1
Application number: PCT/CN2018/094666
Authority: WO
Inventors: Yiqing Cao; Yan Li; Lu Gao
Original assignee: Qualcomm Incorporated
Priority date: 2018-07-05
Filing date: 2018-07-05
Publication date: 2020-01-09
Also published as: WO2020007126A1

Abstract

Various features and aspects related to forming and/or managing a group of devices (e.g., a platoon of vehicles) in a V2V and/orV2X network are described. In accordance one aspect, a UE may desire to form a group including one or more other UEs to utilize the advantages and benefits of operating as a platoon. The UE may volunteer to become a head of the group and facilitate coordination between group members traveling together as the group. For an existing group, a group head that may no longer desire to be the group head may announce a quit decision and facilitate selection of a new group head. In one configuration, the UE may transmit a volunteer message indicating an intention to be a head of the group. The first UE may determine whether to become the group based on a number of ACKs received in response to the volunteer message.

Description

METHODS AND APPARATUS RELATED TO FORMING AND/OR MANAGING A GROUP OF DEVICES

Technical Field

The present disclosure relates generally to communication systems, and more particularly, to methods and apparatus related to forming and/or managing a group of user equipments (e.g., vehicles) in a wireless communication system including, e.g., a vehicular communication system.

Introduction

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

Various features and aspects related to forming and/or managing a group of devices (e.g., a platoon of vehicles) in a wireless communication system (e.g., including vehicular systems such as vehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X) networks) are described. In accordance with the described methods and features thereof, a user equipment (UE) may desire to form a platooning group including one or more other UEs to utilize the advantages and benefits of operating as the platooning group. The UE may volunteer to become a head of the group and facilitate coordination between group members traveling together as the group. Furthermore, in accordance with the disclosed methods, for an existing group, a group head that may no longer desire to be the head of the group may announce a quit decision and facilitate selection of a new group head.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a first UE (e.g., a vehicle in a V2V/V2X network) . The first UE may be configured to transmit (e.g., broadcast or multicast) a first volunteer message indicating an intention to be a head of the group. In some configurations, the first UE may be further configured to determine whether to become the head of the group based on a first number of acknowledgments (ACKs) received in response to the first volunteer message.

Various additional aspects and features are described in the following detailed description.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram illustrating an example of a wireless communications system and an access network.

FIGs. 1B-1D are diagrams illustrating examples of some architecture options that may be used with the access network of FIG. 1A.

FIGs. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a DL frame structure, DL channels within the DL frame structure, an UL frame structure, and UL channels within the UL frame structure, respectively.

FIG. 2E is a diagram illustrating an example of a DL subframe within an example 5G/NR frame structure.

FIG. 2F is a diagram illustrating an example of an SS Block within a DL subframe within a 5G/NR frame structure.

FIG. 2G is a diagram illustrating an example of an UL subframe within a 5G/NR frame structure.

FIG. 2H is a diagram illustrating an example of a DM-RS configuration type within an UL subframe in an example for 5G/NR.

FIG. 2I illustrates various examples of CSI-RS patterns that may be employed within a slot.

FIG. 3 is a diagram illustrating an example of a base station and UE in an access network.

FIG. 4A illustrates an example of group formation and signaling between UEs (e.g., vehicles) as part of the group formation, in accordance with one aspect.

FIG. 4B illustrates an example of a new group head selection when a current head of group does not wish to remain the group head, in accordance with one aspect.

FIG. 5A illustrates an example process via which an individual UE may volunteer to form a new group and become head of the group.

FIG. 5B illustrates an example process via which a head of a group may quit being the head of the group and facilitate selection of a new group head.

FIG. 6 illustrates two different types of control messages and two different types of data messages that may be used for communication between UEs (e.g., vehicles) in some configurations.

FIG. 7, which comprises a combination of FIG. 7A and FIG. 7B, is a flowchart of a method of wireless communication.

FIG. 8 is a conceptual data flow diagram illustrating the data flow between different means/components in an exemplary apparatus.

FIG. 9 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

FIG. 1A is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, and an Evolved Packet Core (EPC) 160. The base stations 102 may include macro cells (high power cellular base station) and/or small cells (low power cellular base station) . The macro cells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) interface with the EPC 160 through backhaul links 132 (e.g., S1 interface) . In another example, the wireless communications system may comprise 5G Core (5GC) 190. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over backhaul links 134 (e.g., X2 interface) . The backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102'may have a coverage area 110'that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100 MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 192. The D2D communication link 192 may use the DL/UL WWAN spectrum. The D2D communication link 192 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102'may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102'may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

A base station 102, whether a small cell 102'or a large cell (e.g., macro base station) , may include an eNB, gNodeB (gNB) or other type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW /near mmW radio frequency band has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 184 with the UE 104 to compensate for the extremely high path loss and short range.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

In the 5GC example, the base stations 102, may be referred to as Next Generation RAN (NG-RAN) that interface with the 5GC 190 through backhaul links 193 (e.g., S1 interface) . The 5GC 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 194, a Session Management Function (SMF) 196, and a User Plane Function (UPF) 199. The AMF 192 may be in communication with a Unified Data Management (UDM) 191. The AMF 192 is the control node that processes the signaling between the UEs 104 and the 5GC 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 199. The UPF 199 provides UE IP address allocation as well as other functions. The UPF 199 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1A, in certain aspects, a first UE (e.g., such as UE 104 which may be a vehicle or a device installed in a vehicle) may transmit (e.g., broadcast or multicast) a first volunteer message indicating an intention to be a head of a group (198) . The first UE and the group (e.g., a platoon) may be part of a V2V communication network, e.g., within the communication system 100. The first UE determine whether to become the head of the group based on a first number of ACKs received in response to the first volunteer message (198) . Various additional aspects and details of the disclosed methods and apparatus are discussed infra with respect to FIGs 4-10. As discussed infra, various features of the methods described herein support communication and signaling for forming a platooning group including a plurality of vehicles. Furthermore, in accordance with the disclosed methods, for an existing group, a group head that may no longer desire to operate as the head and may announce a quit decision as well as facilitate selection of a new group head.

FIGS. 1B-1D are diagrams 100b, 100c, and 100d illustrating examples of non-standalone (NSA) architecture deployment which may be used in the access network of 100 of FIG. 1A. In some configurations, the UE 104 may simultaneously connect to a first base station (e.g., eNB 102) via a first radio access technology (RAT) and a second base station (e.g., gNB 180) via a second RAT, as shown in FIGS. 5A-5C. For example, the first RAT may comprise and/or support LTE wireless access technology, and the second RAT may comprise and/or support 5G NR wireless access technology.

FIG. 1B illustrates a first option (e.g., option 3x) of an NSA architecture deployment that may be used in the access network 100 in some configurations. In this option, base station 180 (e.g., gNB) may have an S1-U connection to the core network (e.g., EPC 160) via the SGW 166/PGW 172. Base station 102 (e.g., eNB) may have an S1-MME connection to the EPC 160 via the MME 162. This configuration may comprise a DC, split bearer. Thus, with this option, the data may go through both the first base station 102 via LTE and the second base station 180 via 5G NR. The data may combine, or merge at the second base station 180, because the dual connectivity split bearer is anchored at the second base station 180. The consolidated data may be sent to the core network EPC 160 by the second base station 180.

FIG. 1C illustrates a second option (e.g., option 3) of the NSA architecture deployment that may be used in the access network 100 in some configurations. In this option, data may similarly go through both the first base station 102 via LTE and the second base station 180 via 5G NR. However, in this example, the data may combine, or merge at the first base station 102 because the dual connectivity split bearer is anchored at the first base station 102. The consolidated data may be sent to the core network EPC 160 by the first base station 102.

FIG. 1D illustrates a third option (e.g., option 3a) of the NSA architecture deployment that may be used in the access network 100 in some configurations. In this option, the data may only go through the second base station 180, and the second base station 180 may send the data the core network EPC 160.

FIG. 2A is a diagram 200 illustrating an example of a DL subframe within a 5G/NR frame structure. FIG. 2B is a diagram 230 illustrating an example of channels within a DL subframe. FIG. 2C is a diagram 250 illustrating an example of an UL subframe within a 5G/NR frame structure. FIG. 2D is a diagram 280 illustrating an example of channels within an UL subframe. The 5G/NR frame structure may be FDD in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be TDD in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G/NR frame structure is assumed to be TDD, with subframe 4 a DL subframe and subframe 7 an UL subframe. While subframe 4 is illustrated as providing just DL and subframe 7 is illustrated as providing just UL, any particular subframe may be split into different subsets that provide both UL and DL. Note that the description infra applies also to a 5G/NR frame structure that is FDD.

.A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE (indicated as R) . The RS may include demodulation RS (DM-RS) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .

FIG. 2B illustrates an example of various channels within a DL subframe of a frame. The physical control format indicator channel (PCFICH) is within symbol 0 of slot 0, and carries a control format indicator (CFI) that indicates whether the physical downlink control channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustrates a PDCCH that occupies 3 symbols) . The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol. A UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCH may have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subset including one RB pair) . The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) is also within symbol 0 of slot 0 and carries the HARQ indicator (HI) that indicates HARQ acknowledgement (ACK) /negative ACK (NACK) feedback based on the physical uplink shared channel (PUSCH) . The primary synchronization channel (PSCH) may be within symbol 6 of slot 0 within

subframes

0 and 5 of a frame. The PSCH carries a primary synchronization signal (PSS) that is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. The secondary synchronization channel (SSCH) may be within symbol 5 of slot 0 within

subframes

0 and 5 of a frame. The SSCH carries a secondary synchronization signal (SSS) that is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSCH and SSCH to form a synchronization signal (SS) /PBCH block. The MIB provides a number of RBs in the DL system bandwidth, a PHICH configuration, and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 2C, some of the REs carry demodulation reference signals (DM-RS) for channel estimation at the base station. The UE may additionally transmit sounding reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various channels within an UL subframe of a frame. A physical random access channel (PRACH) may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial system access and achieve UL synchronization. A physical uplink control channel (PUCCH) may be located on edges of the UL system bandwidth. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

Other examples may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2 ^μ*15 kKz, where μ is the numerology 0-5. The symbol length/duration is inversely related to the subcarrier spacing. FIGs. 2A, 2C provide an example of a slot configuration with 14 symbols per slot and numerology 0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and symbol duration is approximately 66.7 μs.

FIG. 2E is a diagram 220 illustrating an example of a DL subframe within an example 5G/NR frame structure. FIG. 2F is a diagram 240 illustrating an example of an SS Block within a DL subframe within a 5G/NR frame structure. FIG. 2G is a diagram 260 illustrating an example of an UL subframe within a 5G/NR frame structure. FIG. 2H is a diagram 280 illustrating an example of a DM-RS configuration type within an UL subframe in an example for 5G/NR. Similar to the examples in FIGs. 2A and 2C, the 5G/NR frame structure may be FDD or may be TDD. In the examples provided by FIGs. 2E, 2G, the 5G/NR frame structure is assumed to be TDD, with subframe 4 a DL subframe and subframe 7 an UL subframe. While subframe 4 is illustrated as providing just DL and subframe 7 is illustrated as providing just UL, any particular subframe may be split into different subsets that provide both UL and DL. Note that the description infra applies also to a 5G/NR frame structure that is FDD.

As with the example of FIGs. 2A-2D, a resource grid may be used to represent the 5G NR frame structure. Each time slot includes an RB (also referred to as PRBs) that extends 12 consecutive subcarriers. The resource grid is divided into multiple REs. The number of bits carried by each RE depends on the modulation scheme. The example slot in FIGs. 2E and 2G comprise 14 OFDM symbols. There may be multiple slots in a subframe, e.g., based on the numerology used. Mini-slots may also be supported, e.g., with a mini-slot being as small as 2 OFDM symbols and having a variable length. Mini-slots may also be positioned asynchronously with a beginning of a slot.

FIG. 2E illustrates an example frame structure 220 for an uplink slot. The uplink slot may comprise CSI-RS. Any of a number of different CSI-RS patterns may be used for CSI-RS transmissions from a base station. FIG. 2I shows various examples of CSI-RS patterns that may be employed within a slot.

Example patterns

201, 202, 203, 204, 206, and 209 show examples in which CSI-RS may be transmitted only in a first symbol, e.g., symbol 0, of the slot.

Example patterns

205, 207, 208, 210, 211, and 212 illustrate examples in which CSI-RS may be transmitted only in symbol 0 and symbol 1 of a slot.

Example patterns

215 and 218 show examples in which CSI-RS is transmitted in the first four symbols of the slot.

Example patterns

213, 214, 218, and 217 illustrate patterns in which CSI-RS is transmitted in symbol 0, symbol 1, symbol 6, and symbol 7 of a slot. CSI-RS from different Code Division Multiplexed (CDM) groups may be comprised within a slot. Different patterns are used to indicate CSI-RS for different CDM groups. Thus,

example patterns

201, 202, and 203 illustrate example CSI-RS patterns for a single CDM group. Example patters 204, 205, and 208 show CSI-RS patterns for two different CDM groups. Example,

patterns

206, 210, and 215 illustrate example CSI-RS patterns for three different CDM groups, and so forth. For a given pattern, different CSI-RS components can be placed anywhere in the RB. For a given pattern, when different CSI-RS components are not shown in adjacent OFDM symbols, they can be placed anywhere in the slot. In a first example, CSI-RS may be transmitted by a single CDM group in a symbol 0, with the CSI-RS transmitted every 4 subcarriers. In another example, the CSI-RS may be transmitted in a single subcarrier in symbol 0. In another example, the CSI-RS may be transmitted two adjacent subcarriers in symbol 0.

FIG. 2F illustrates an example of various channels within a DL subframe of an SS Block in 5G NR. The SS Block may comprise a PSS, SSS, and PBCH. The SS block may comprise 4 OFDM symbols, as illustrated in the example of FIG. 2F. The SS block may comprise multiple RBs, e.g., 20 RBs corresponding to 240 subcarriers in frequency. In a slot of 14 symbols, two possible locations of the SS block include symbol 2-symbol 5, as illustrated in FIG. 2F and symbol 8-symbol 11. As illustrated, an SS block may comprise 1 symbol of PSS, 1 symbol of SSS, and at least two symbols of PBCH. The PSS, SSS, and PBCH may be time division multiplexed in consecutive symbols, e.g., for both a single beam example and multi-beam example. FIG. 2F illustrates an example time domain mapping, with PSS in one symbol, followed by a symbol comprising PBCH. The, a symbol of both SSS and PBCH is followed by a symbol comprising PBCH. Different subcarrier spacing for PSS/SSS may be used in connection with different frequency ranges. For example, a first subcarrier spacing for PSS/SSS may be used for a sub-6 frequency range a 15 kHz or 30kHz subcarrier spacing may be used. For a frequency range above the sub-6 range, a 120 kHz or 240 kHz subcarrier spacing may be used.

As illustrated in FIG. 2G, DM-RS may start at symbol 2 in a slot. While illustrated as only a single symbol the DM-RS may comprise both symbol 2 and symbol 3. There may be multiple configuration types for the DM-RS. A first configuration type, e.g., Configuration type 1, may transmit the DM-RS from two different ports, and within the same symbol, each subcarrier may have DM-RS from a different port. Configuration type 1 may include one OFDM symbol, as illustrated in FIG. 2G. In another example, the Configuration type 1 DM-RS may include two OFDM symbols, with the same port transmitting DM-RS within a subcarrier. Different phases of a complex sequence value for the DM-RS may be used in adjacent symbols in some patterns. In other patterns, the same phase may be used in adjacent symbols. Different phases of the complex sequence value for the DM-RS may be used in adjacent subcarriers in some patterns. In other patterns, the same phase may be used in adjacent subcarriers. FIG. 2H illustrates an example of Configuration type 2 DM-RS in which three different ports are used for the DM-RS. In Configuration type 2 DM-RS, every two subcarriers may carry DM-RS from one of three ports. As with Configuration 1, the DM-RS may be transmitted in a single symbol, e.g., at symbol 2, or may be transmitted in two symbols, e.g., symbol 2 and symbol 3. Uplink communication in the example of FIG. 2G may also comprise SRS. Rather than being located in the last symbol, as illustrated in FIG. 2C, the SRS can be configured to occupy a location within any of the last 6 symbols in a slot. The frequency domain starting position of the SRS allocation be configuration in a UE specific manner.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 and/or 5GC 190 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression /decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160 and/or 5GC 190. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression /decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission. In some configurations, the UE 350 (e.g., vehicle) may operate in a half-duplex mode where the UE 350 may only either transmit or receive at a given time. The half-duplex mode operation may be due to a given deployment scenario (e.g., such as when performing V2V and/or V2X communications) that may desire a half-duplex operation by devices, or due to UE capability (e.g., such as where the UE 350 may have a single TX/RX chain (354TX/RX) . In such configurations where the UE 350 may operate in the half-duplex mode, the UE 350 may not perform simultaneous transmission and reception.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160 and/or 5GC 190. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Platooning may be described as operating a group of vehicles in a closely linked manner such that the vehicles may move in a coordinated manner as if connected by virtual strings. To maintain distance between the vehicles, the vehicles may share status information such as speed, heading and intentions such as braking, acceleration, etc. By use of platooning, the distances between vehicles may be reduced, overall fuel consumption may be lowered (and thus fuel efficiency may be improved) , and the number of needed drivers may be reduced. In addition, an overall user experience may be improved with a sense of traveling together in a group and being connected with others.

However, mechanisms and signaling desired for establishing (e.g., forming) a platooning group and/or voluntarily heading the group are not well support in the current wireless communication systems. Further, techniques and signaling for selecting a new group head when an existing heads wants to leave the group or does not wish to remain the head of the group are also not well defined and support in the existing systems. In view of the above, it should be appreciated methods, apparatus and signaling that support forming and/or managing a group (e.g., a platoon of vehicles) in a wireless communication system are desired.

Various features and aspects related to forming a group (e.g., a platooning group or simply a platoon) and/or managing such a group in a wireless communication system (e.g., including vehicular communication networks such as V2V/V2X and/or eV2X networks) are described. In accordance with the described methods and features thereof, a UE may desire to form a platooning group including one or more other UEs to utilize the advantages and benefits of operating as the platooning group. The UE may volunteer to become a head of the group and facilitate coordination between group members traveling together as the group. Furthermore, in accordance with the disclosed methods, for an existing group, a group head that may no longer desire to be the head of the group may announce a quit decision and facilitate selection of a new group head. Various additional aspects and features are discussed infra in more detail.

FIG. 4A illustrates a diagram 400 of an example of forming a platooning group 401 in accordance with one aspect. For discussion purposes, consider that in the example initially multiple individual UEs (e.g.,

UEs

402, 404, 406, 408, and 410) may exist (e.g., may be traveling in the same direction) within V2V communication range but not as a group (e.g., initially group 401 does not exist) . A UE (e.g., UE 410) , that may be interested in traveling with a group (e.g., a platoon) to utilize the advantages of coordinated movement and other benefits of platooning, may determine whether a platoon already exists. For example, determination regarding existence of a group may be based on group announcement messages heard from a neighboring UE. Assuming that the UE 410 determines that no group exists at the given time, in an aspect the UE 410 may decide to attempt to form a group, e.g., with neighboring UEs that may also be interested in traveling as a platoon. In accordance with one aspect, the UE may transmit a first volunteer message 412 including information indicating an intention to form a group. The first volunteer message 412 may further indicate that the UE 410 volunteers to become the head of the proposed group. In some configurations, the first volunteer message may be transmitted as a broadcast that may be received by the neighboring

UEs

402, 404, 406, and 408.

In accordance with one aspect, following transmission of the first volunteer message, the UE 410 may monitor for a response to the first volunteer message 412 from other neighboring UEs for a predetermined time period, e.g., a first time period. In some configurations, the first time period may be preconfigured. In some other configurations, the first time period may be configured by the UE 410 or a network node (e.g., base station or another core network node) . In accordance with one aspect, one or more other UEs that may wish to join the group with the UE 410 as the head may respond with an acknowledgement (ACK) . In one configuration, the ACKs from such one or more UEs may be broadcast. In an aspect, the UE 410 may determine (at 422) whether to become the head of the group based on a number of ACKs received in response to the first volunteer message 412. In some configurations, an ACK may include an explicit indication (e.g., a UE identifier) regarding the UE (e.g., UE 410) for which the ACK is intended. In some other configurations, the time and frequency resources on which an ACK is transmitted by a responding UE (such as

UEs

402, 404, 406, or 408) may correspond to and/or be associated with the time and frequency resources used for the transmission of the corresponding volunteer message. Accordingly, the UE 410 monitoring for a response to the first volunteer message 412 may be able to determine whether one or more detected ACKs are in response to the first volunteer message 412 (e.g., are intended for the UE 410) , e.g., based on an explicit indication of an identifier of the UE 410 in the one or more ACKs, and/or the time and frequency resources on which the one or more ACKs are received (e.g., based on the correspondence/association between the resources used for transmitting the first volunteer message and the resources on which an ACK is received) .

Based on the monitoring and the above criteria, the UE 410 may determine the number of ACKs received in response to the first volunteer message 412. For instance, in the illustrated example, a first ACK 416 (from UE 402) and a second ACK 418 (from UE 404) may both be in response to the first volunteer message 412. In one configuration, the UE 410 may determine (at 420) to become the head of the group when the number of ACKs received in response to the first volunteer message 412 within the predetermined time period is greater than or equal to a threshold number, and to not become the head when the number of ACKs is less than the threshold number. For example, the threshold number may be 1 or a higher number. In one configuration, the UE 410 may determine to form the group and become the head if the number of received ACKs in response to volunteer message 412 is greater than or equal to the threshold number, otherwise may refrain from forming the group.

However, in some configurations, the UE 410 may be configured to determine (at 422) whether to become the head of the group further based on a number of ACKs intended for one or more other UEs that may also have transmitted volunteer message with the intention of forming a group and becoming a head. For example, in diagram 400, UE 406 may have transmitted a second volunteer message 414 (with the intention of forming a group and becoming a head) that may be heard by the

UEs

402, 404, 408, and 410. Furthermore, the ACK 420 may be transmitted from UE 408 in response to the second volunteer message 414. When monitoring for responses, UE 410 and UE 406 may both hear the ACKs, 416, 418, and 420, and may determine how many ACKs each of the

UEs

410 and 406 received in response to its own volunteer message transmission (412 and 414) . In accordance with one aspect, the UE (406 or 410) that may receive the most ACKs in response to its transmitted volunteer message may form the group and become the head. Thus, UE 410 and UE 406 may each individually determine whether to form the group and become the head based on the number of ACKs received in response to its own volunteer message as compared to the number of ACKs intended for the other candidate. For example, in the case illustrated in diagram 400, based on an explicit or implicit indication in the

ACKs

416, 418, and 420, UE 406 and UE 410 may each determine (e.g., at 424 and 422 respectively) that only one ACK (ACK 420) is received in response to the second volunteer message 414 transmitted by UE 406, whereas two ACKs (ACK 416 and 418) are received in response to the first volunteer message transmitted by UE 410. Accordingly, in this example, UE 410 may determine to form the group and become the head while UE 406 may yield and determine to not form a group and become the head.

Having determined to form the group and become the head, the UE 410 may transmit a first type of control message 430 including information indicating formation of the group 401 and that the UE is the head of the group 401. The control message 430 may be transmitted as an announcement to indicate formation of the group 401. In one configuration, the first type of control message 430 may include at least one of an indication to form the group, an indication to be the head of the group, transmission resources for a first type of data message, and transmission parameters for the first type of data message. One or more of the

other UEs

402, 404, 406, and 408 that may be interested in joining the group 401 may communicate with UE 410 (group head) and join the group 401 if desired.

FIG. 4B is a diagram 450 illustrating an example of a new group head selection when a current head of a group 401 does not wish to remain the group head, in accordance with one aspect. In the example of FIG. 4B,

UEs

402, 404, 406, 408, and 410 may be a part of the group 401 (e.g., a platoon in a vehicular communication system that supports V2V, V2X, and eV2X communications) . In the example of FIG. 4B, the group 401 may be headed by UE 410. At some point of time during the operation, UE 410 may determine that the UE 410 does not want to remain the head of the group 401. Such a determination may be due to shortage in available power and/or other resources (e.g., battery power, fuel and/or other resources utilized by the UE 410) . In some cases, operating as the group head may be associated with more power/resource consumption due to a relatively heavier use of power and/or other resources by the UE 410 to manage the platooning group 401 and function as the group head. Accordingly, in certain situations, the UE 410 may desire to no longer remain the head of the group 401.

In accordance with one aspect, when the UE 410 determines to no longer remain the head of the group 401, the UE 410 may transmit a quit message 454 indicating an intention to quit as the head of the group 401. In some configurations, the quit message may be a broadcast message, or a multicast to the group members. In one aspect, in addition to indicating the intention of the UE 410 to no longer operate as the head of the group 401, the quit message 454 may also serve as an announcement that a new group head is needed for the group 401. The quit message 454 may also serve as an implicit/explicit solicitation for volunteers (e.g., among group members and/or non-members) to become the head of the group 401.

In accordance with one aspect, one or more of the UEs that may receive the quit message 454 and may be interested in becoming the group head may each transmit a volunteer message in response to the quit message 454 to indicate an intention to become the head of the group 401. For example, as illustrated in diagram 450,

UEs

406 and 408 may be both interested in becoming the head and transmit their

respective volunteer messages

456 and 458. In accordance with one aspect, the current group head UE 410 may be configured to select (at 465) a new head from the one or more UEs (e.g., UEs 406 and 408) that indicate an intention to become the head via their volunteer messages. In some configurations, the UE 410 may select, as the new group head, the UE that receives the maximum number of ACKs in response to its volunteer message. In the illustrated example, consider that

UEs

402 and 404 may each transmit an ACK (e.g., ACK 460 and ACK 462) in response to the volunteer message 456 from UE 406. Thus, in this example, 2 ACKs are intended for UE 406 while no ACK was transmitted in response to the volunteer message 458 from the other volunteer UE (UE 408) . The current group head UE 410 may hear the

ACKs

460 and 462 and may determine that out of the two

volunteers UE

406 and 408, UE 406 received a higher number of ACKs. Accordingly, the UE 410 may select (at 465) UE 406 as the new head of the group 401. In one configuration, the UE 410 and/or the new head UE 406 may transmit a message 466 indicating that UE 406 is the new head of the group 401.

In an example where no volunteer message is received in response to the quit message 454 within a predetermined time period, the UE 410 may either monitor for volunteer messages from one or more UEs for an extended time period, or alternatively dismiss the group, e.g., if the UE 410 may no longer have the resources/power to operate as the group head and/or to conserve resources/power.

In another configuration, the selection of the new head may not be centralized (e.g., may not be by the current head UE 410) and may rather be made in a manner similar to the example discussed above in connection with FIG. 4A. For example, there may be a plurality of volunteers that may transmit volunteers messages (such as UE 406 and 408) and the UE that receives a greater number of ACKs may declare itself the head of the group.

FIG. 5A illustrates a diagram 500 depicting an example process of forming a new group. The illustrated example merely shows a few steps of the process to facilitate an understanding of the proposed concepts. In the illustrated example, at stage 502, a first UE (e.g., a vehicle) that may be interested in forming a new group (e.g., a platoon may volunteer to be a head of a proposed group. For example, with reference to FIG. 4A, the UE 410 may broadcast a volunteer message 414 indicating an intention to form and group and become the head of the group.

In the illustrated example process, at processing stage 504, following the transmission of the volunteer message, the first UE may monitor for responses (e.g., ACKs) from other neighboring UEs that may be interested in joining the proposed group in response to the volunteer message. In accordance with an aspect, the first UE may monitor for ACKs for a first time period (e.g., T) . If the first UE receives equal to or more than a threshold number (e.g., K) of ACKs, the new group may be formed and the first UE may become the head as described supra with regard to the example discussed in connection with of FIG. 4A. However, if the received number of ACKs is less than the threshold number (K) , the first UE may decide to not form the new group.

FIG. 5B illustrates a diagram 550 depicting an example process via which a new group head may be selected in a case where the current head of the group no longer desires to operate as the group head. The illustrated example merely shows a few steps of the process. For a better understanding of the proposed concepts, the example process shown in diagram 550 may be discussed with reference to FIG. 4B. In the illustrated example, at stage 552, a first UE (e.g., group head such as UE 410 in FIG. 4B) may determine that the first UE does not want to remain the head of the group. For example, with reference to FIG. 4B, for one or more reasons such as due to shortage in available power and/or other resources (e.g., battery power, fuel and/or other resources utilized by the UE 410) , the UE 410 may decide to no longer operate as the head of the group 401. In accordance with one aspect, the first UE may transmit a quit message (e.g., such quit message 454) indicating an intention to quit as the head of the group. In some configurations, the quit message may be a broadcast message, or a multicast to the group members.

In accordance with one aspect, at processing stage 554, one or more of the UEs that may receive the quit message and may be interested in becoming the group head may each respond to the quit message to indicate an intention to become the head of the group 401. For example, as illustrated in diagram 450,

UEs

406 and 408 may be both interested in becoming the head and transmit their

respective volunteer messages

456 and 458, e.g., following the announcement by the head UE 410 to quit. Each of the one or more UEs (e.g., UEs 406 and 408) and/or the group head (e.g., UE 410) may monitor for ACKs in response to the transmitted volunteer messages.

At processing stage 554, a decision regarding the new head of the group may be made. In accordance with one aspect, the current group head UE 410 may select a new head from the one or more UEs (e.g., UEs 406 and 408) that indicate an intention to become the head, e.g., based on a corresponding number of ACKs received, within a predetermined time period, in response to the volunteer messages (e.g., such as messages 456 and 458) transmitted by each of the one or more UEs. For example, the UE 410 may select, as the new group head, the UE that receives the maximum number of ACKs in response to its volunteer message. Alternatively, the selection of the new head may not be centralized (e.g., may not be by the current head UE) and may rather be made by the volunteer UEs in a manner similar to the example discussed above in connection with FIG. 4A. For example, the volunteer UE that receives a greater number of ACKs in response to its volunteer message may declare itself the head of the group. As discussed supra, each ACK may explicitly or implicitly indicate the intended recipient (even though the ACK may be broadcast by the transmitter and heard by more than just the intended receiver) . Thus, the current head as well as various volunteer UEs may be able to detect the various transmitted ACKs and thus may determine which volunteer UE has the most ACKs.

Stage 558 corresponds to an example case where no volunteers are detected (e.g., no volunteer messages may be received in response to the quit message from the current head) within a predetermined time period. In such a case, at stage 558 when no volunteers for becoming the group head are detected within the predetermined time period, the current head (e.g., UE 410) may either decide to monitor for volunteer messages from one or more UEs for an extended time period, or alternatively dismiss the group, e.g., to conserve resources/power.

FIG. 6 is a diagram 600 illustrating two different types of control messages and two different types of data messages that may be used for communication between UEs (e.g., vehicles) in some configurations. In accordance with one aspect, two types of control messages are supported, e.g., control message type-1 610 and control message type-2 620, and two types of data messages, e.g., data message type 1 630 and data message type 2 640, are supported. The first type of control message (control message type-1) 610 may be transmitted by individual UEs (e.g., members and a head of a platooning group as well as other individual non-member UEs) , whereas the second type of control message (control message type-2) 620 may be transmitted only by the head of a platooning group. Similarly, the first type of data message (data message type-1) 630 may be transmitted by individual UEs (e.g., members and a head of a platooning group as well as other individual non-member UEs) , whereas the second type of data message (data message type-2) 640 may be transmitted only by the head of a platooning group.

The control message type-1 610 may be transmitted by a UE (e.g., as an individual UE or as a group head) and may include, for example, one or more of the following types of information: an indication to form a group, an indication to be the head of a group, a query/invitation to join a group, transmission resources for the first type of data message (data message type-1) , and transmission parameters for the first type of data message. For example, a control message type-1 610 may indicate transmission resources on which a corresponding data message type-1 630 may be transmitted. The transmission resources may comprise one or more of time, frequency and spatial resources. Similarly, the control message type-1 610 may indicate one or more parameters for the corresponding data message type-1 630. For example, the parameters for the first type of data message comprise one or more of a modulation and coding scheme (MCS) , a new data indicator, and a retransmission indicator. As another example, the control message type-1 610 may include the vehicle’s speed and/or position. The control message type-1 610 may include a transmit power for the UE, e.g., a transmit power at which the UE transmits communication to the group of UEs. For example, with reference to FIG. 4A, the message 430 (transmitted by the UE 410) including information indicating formation of the group and that the UE 410 is the head of the group may be the control message type-1 630.

The control message type-2 620 may be transmitted by a UE (e.g., UE 410 operating as the group head) and may include, for example, one or more of the following information: a group identifier (ID) of a group with which the head is associated, transmission resources for the second type of data message transmitted by the group head (e.g., data message type-2 640) , transmission parameters for the second type of data message, and a HARQ resource indicator. For example, the indicated transmission resources for the second type of data message may comprise one or more of time, frequency and spatial resources, and the indicated transmission parameters may comprise one or more of an MCS, and a retransmission indicator.

The data message type-1 630 may be transmitted by a UE (e.g., as an individual UE or as a group head) and may include, for example, information indicating one or more of: information corresponding to the transmitting UE (e.g., vehicle information such as speed of the UE, direction of the UE, position of the UE, etc. ) , a request to join a group (e.g., including a group ID of the group) when the transmitting UE is requesting to join the platooning group, and an ACK to a group head (e.g., in response to a message from the group head) .

The data message type-2 640 transmitted by a UE (e.g., group head) may include one or more of: information indicating a need for a new group head, group information for a platooning group such as a group ID, a speed of the group, a direction of the group, positioning information of the group, a braking indication/instruction, and an acceleration indication/instruction, and information indicating an acceptance of a request to join a group, group member IDs of one or more members, a number of members in the group, and a route of the group. In some configurations, the data message type-2 640 may further include one or more of inter-vehicle distance information (e.g., distance between adjacent members) , individual vehicle control information (e.g., proposed speed for each group member, position, proposed transmission power for each group member) . For example, with reference to FIG. 4B, the quite message 454 transmitted by the UE 410 as the head of the group 401 may be a second type of data message (data message type-2 640) .

From the perspective of a receiving UE, both types of control messages and data messages may be accessible by the receiving UE whether the receiving UE is the group head, a member, or a non-member UE. Various additional features and aspects are discussed infra in connection with the flowchart 700 of FIG. 8.

FIG. 7 is a flowchart 700 of a method of wireless communication at a first UE. The method may be performed, for example, by the UE (e.g.,

UE

104, 350, 410 (or another UE shown in diagrams 400/450) , the apparatus 802/802') . To facilitate an understanding of the techniques and concepts described herein, the method of flowchart 700 may be discussed with reference to the examples illustrated in FIGs. 4A and 4B. For discussion purposes, consider that the first UE may be the UE 410. At 702, the first UE may be powered on and initialized.

At 704, the first UE may transmit (e.g., broadcast or multicast) a first volunteer message indicating an intention to be a head of the group. For example, with reference to FIG. 4A, the first volunteer message may be the message 412 transmitted by the UE 410 with the intention of becoming a head of platooning group. In one configuration, there may be no existing group (e.g., as in FIG. 4A example) in which case the first volunteer message may indicate a request or interest to form a new group and serve as the head of the proposed group. In another configuration, a platooning group may already exist (e.g., as in FIG. 4B example) and the transmitted first volunteer message may be in response to a quit message or announcement for need of a new head by a current group head.

At 706, the first UE may determine whether to become the head of the group, e.g., based at least on a first number of ACKs received in response to the first volunteer message and/or other factors discussed below. For example, with reference to FIG. 4A, the UE 410 may determine (at 422) whether to become the head of the group based on a number of ACKs received in response to the first volunteer message 412. As discussed supra in connection with FIG. 4A, following transmission of the first volunteer message (e.g., message 412) , the first UE may monitor for a response to the first volunteer message from other neighboring UEs for a predetermined time period, e.g., a first time period. One or more other UEs that may be interested in the first UE becoming the head of the group and/or formation of a new group (if a new group is being formed) may respond with an ACK.

As part of the operation (block 706) of determining whether to become the head of the group, one or more sub-operations illustrated within block 706 may be performed. At 708, the first UE may determine whether one or more ACKs are detected during the monitoring within a first time period from one or more other UEs. In some configurations, the first time period may be preconfigured. In some other configurations, the first time period may be configured by the first UE 410 or a network node (e.g., base station or another core network node) . If, at 708, it is determined that no ACK was detected within the first time period (e.g., no other vehicle transmitted ACK or the first UE failed to receive) , the operation may proceed to 710. At 710, the first UE may determine to not become the head of the group, e.g., due to a failure to receive one or more ACKs in response to the transmitted first volunteer message. In the case where a group does not exist, the determination at 710 may further include the first UE determining to not form a new group. If a group already exists, then at 710, the first UE may simply determine to not become the head.

If, at 708, it is determined that one or more ACKs are detected within the first time period, the operation may proceed to 712. At 712, the first UE may receive and process (e.g., decode, demodulate, recover information) the one or more ACKs.

Next, at 714, the first UE may determine if the received one or more ACKs are in response to the first volunteer message (e.g., intended for the first UE) . As discussed supra, in some configurations, an ACK may include an explicit indication (e.g., a first UE identifier) regarding the first UE for which the ACK is intended. In some other configurations, the time and frequency resources on which an ACK is transmitted by a responding UE may correspond to and/or be associated with the time and frequency resources used the transmission of a corresponding volunteer message. Thus, the first UE monitoring for a response to the first volunteer message may be able to determine whether one or more detected ACKs are in response to the first volunteer message (e.g., are intended for the UE) or intended for another UE. If, at 714, it is determined that the received one or more ACKs are not in response to the first volunteer message, the operation may proceed to 710 where the first UE may determine to not become the head of the group as discussed above. If, at 714, it is determined that the received one or more ACKs are in response to the first volunteer message (e.g., are intended for the first UE) , the operation may proceed to 716.

At 716, the first UE may determine if the number of ACKs received in response to the first volunteer message is greater than or equal to a threshold number. In some configurations, the threshold number may be preconfigured. In some configurations, the threshold number may be configured by the head of the group (e.g., if the group with a head already exists) or a network node (e.g., base station or another core network node) . If, at 716, it is determined that the number of ACKs received in response to the first volunteer message is less than the threshold number, the operation may proceed to 710 where the first UE may determine to not become the head of the group as discussed above. If, at 716, it is determined that the number of ACKs received in response to the first volunteer message is greater than or equal to the threshold number, the operation may proceed to 718.

At 718, the first UE may determine if any ACKs in response to at least one other volunteer message (e.g., which may have been transmitted by other volunteers) have been detected. For example, with reference to FIG. 4A, the UE 410 may determine if any of the ACKs detected within the first time period are intended for another UE and may further determine a number of such ACKs intended for one or more other UEs that may also have transmitted volunteer messages. For example, with reference to FIG. 4A, the UE 410 may determine that one received ACK (e.g., ACK 420) is in response to the second volunteer message 414 transmitted by UE 406, whereas two ACKs (e.g., ACKs 416 and 418) are received in response to the first volunteer message transmitted by UE 410. If at 718, it is determined that none of the received ACKs are intended for another UE (e.g., all received ACKs are in response to the first volunteer message) , the operation may proceed to 720.

At 720, the first UE may determine to become the head of the group, e.g., based on the criteria that the number of ACKs in response to the first volunteer message is greater than or equal to the threshold number, and there may be no other competing volunteers as no other ACKs intended for other UEs are detected. Operation may proceed from block 720 to block 724.

If, at 718, it is determined that the received ACKs include one or more ACKs intended for one or more other UEs (e.g., ACKs in response to at least one other volunteer message have been detected) , the operation may proceed to 722. At 722, the first UE may perform a comparison to determine if the number of ACKs received in response to the first volunteer message is greater than the number of ACKs (e.g., intended for other UE (s) ) in response to the at least one other volunteer message. As discussed supra, such a comparison may be performed to determine whether the first UE or another different UE received a greater number of ACKs. If, at 722, it is determined that the number of ACKs received by at least one other UE in response to its volunteer message is greater than the number of ACKs received by the first UE in response to the first volunteer message transmitted by the first UE, the operation may proceed to 710 via block 723. As discussed supra, at 710 the first UE may determine to not become the head of the group. If, at 722, it is determined that the number of ACKs received by the first UE in response to the first volunteer message is greater than the number of ACKs received by the at least one other UE (e.g., the first UE has the greatest number of ACKs) , the operation may proceed to 720 where the first UE may determine to become the head of the group as discussed supra. Thus, in accordance with one aspect, the first UE may determine to become the head of the group when the number of ACKs received in response to the first volunteer message within the predetermined time period is greater than the number of ACKs received by other UEs in response to their volunteer message transmissions as discussed in more detail in connection with FIG. 4A.

Operation proceeds from 720 to 724. Having determined to become the group head, next at 724, the first UE may determine whether the group already exists or a new group is to be formed for which the first UE is to become the head. If the group already exists (e.g., an existing group may need a new head as discussed in FIG. 4B example) , the operation may proceed from 724 to 726. At 726, a prior head of the group is replaced and the first UE becomes the head of the group. Next, at 728, the first UE may transmit a first type of control message including information indicating that the first UE is the new head of the group. Operation may proceed from 728 to 732 via connecting node A 731.

On the other hand, if at 724, it is determined that a new group is to be formed (e.g., no group exists and the first UE is to form a new group as discussed in FIG. 4A example) , the operation proceed may proceed from 724 to 730. At 730, the first UE may transmit a first type of control message including information indicating formation of the group and that the first UE is the head of the group. Operation may proceed from 730 to 732 via connecting node A 731.

At 732, the first UE may start operating as the head of the group, e.g., the first UE may control and/or coordinate movement of group members to travel together as a platooning group.

At some point of time during the operation, the first UE may determine that the first UE does not want to remain the head of the group. Accordingly, at 734, the first UE may transmit (e.g., broadcast, or group multicast to group members) a quit message indicating an intention to quit as the head of the group. The quit message may also indicate that a new group head is needed. For example, with reference to FIG. 4B, the UE 410 may transmit a quit message 454 indicating an intention to quit as the head of the group 401. One or more member UEs of the group and possibly non-members UEs as well (e.g., in case the quit message is broadcast) may receive the transmitted quit message. The one or more of the UEs that may receive the quit message and interested in becoming the group head may each transmit a second volunteer message in response to the quit message to indicate an intention to become the head of the group.

At 736, the first UE may determine whether one or more volunteer messages are detected within a second time period, e.g., in response to the quit message, e.g.. For example, the second time period may be a predetermined time period, or a set time period configured by the group head, or a time period configured by a network node. The second time period may be the same or different from the first time period. In some configurations, as part of the operation at 736, the first UE may determine whether more than a threshold number of volunteer messages are detected within the second time period. For example, the threshold number may be as low as 1, or may be set (e.g., by group head or a network node) as a higher number. In one configuration, if volunteer messages less than the threshold number are detected, then it may be considered as if no volunteer messages are detected. However, in some other configurations, threshold number criteria may not be followed. If, at 738, it is determined that no volunteer messages are detected within the second time period, the operation may proceed to 738.

At 738, the first UE may either decide to continue monitoring for volunteer messages from other UEs in response to the quit message for an extended time period (e.g., for another duration corresponding to a multiple of the second time period) or otherwise may decide to dismiss the group. In some configurations, if no volunteer message is detected even during one or more iterations (e.g., during the monitoring for extended time period) , the first UE may dismiss the group.

If, at 738, it is determined that volunteer messages are detected within the second time period (one or more UEs may each transmit a volunteer message in response to the quit message) , the operation may proceed to 740. At 740, the first UE may receive and process a second volunteer message (e.g., in response to the quit message) from one or more UEs. For example, as illustrated in diagram 450,

UEs

406 and 408 may be both interested in becoming the head and transmit their

respective volunteer messages

456 and 458 that is received by the head UE 410.

Finally at 742, the first UE may select a new head of the group from the one or more UEs that transmitted the second volunteer message. For example, in accordance with one aspect, the new head may be selected based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs. For example, the first UE may monitor for ACKs in response to the second volunteer message and may select, as the new group head, the UE that receives the maximum number of ACKs in response to its corresponding volunteer message. For example, with reference to Fig. 4B, that

UEs

402 and 404 may each transmit an ACK (e.g., ACK 460 and ACK 462) in response to the volunteer message 456 from UE 406. whereas no ACK may be transmitted for UE 408. Thus, in such an example, the first UE (current group head) may select UE 406 (that received the most ACKs) as the new head of the group 401. In one configuration, the first UE 410 and/or the newly selected head of the group may transmit a message announcing the new head.

FIG. 8 is a conceptual data flow diagram 800 illustrating the data flow between different means/components in an exemplary apparatus 802. The apparatus may be a first UE, e.g., a first vehicle in a V2V/V2X/eV2X communication network, that may implement the method of flowchart 700. In one configuration, the apparatus 802 may include a reception component 804, a control and data message component 805 (including a group message component 812, a volunteer message component 814, and quit message component 816) , an ACK determination component 806, a determination component a determination component 808, a selection component 810, and a transmission component 818. The apparatus 802 may include additional components that may perform one or more additional operations/functions discussed supra in connection with FIGs. 4-8. The UE 850 may include the same or similar components as shown with respect to the apparatus 802 and discussed below. The apparatus 802 and the UE 850 may each be a vehicle or included in a vehicle.

The reception component 804 may be configured to receive various types of messages described herein (e.g., volunteer messages, group messages, quit messages, ACKs, etc. ) and/or other information from other devices (e.g., vehicles) including UE 850. The messages/information may be received via the reception component 804 in accordance with the methods discussed supra, including the method of flowchart 700. For example, via the reception component 804, the apparatus 802 (or the components included therein) may receive the first type and/or the second type of control and data messages discussed supra. The received messages/information may be provided to one or more components of the apparatus 802 for further processing and use in performing various operations. In some configurations, the reception component 804 may operate in combination with and/or under the control of one or more other components of the apparatus 802. For example, in some configurations, under the control and/or in coordination with one or more of the other components, the reception component 804 may be configured to monitor for various types of messages for different time periods a preconfigured or set time period, e.g., in accordance with the method of flowchart 700.

The control and data message component 805 may be configured to generate and transmit (e.g., via the transmission component 818) the first type and/or the second type of control and data messages discussed supra. Furthermore, the control and data message component 805 may be configured to receive (e.g., via the reception component 804) and process the first type and/or the second type of control and data messages. In some configuration, the control and data message component 805 may include a group message component 812, a volunteer message component 814, and quit message component 816. For example, the volunteer message component 814 may be configured to generate and transmit (e.g., via the transmission component 818) a first volunteer message indicating an intention (of the apparatus 802) to be a head of the group. As discussed supra, in some configurations, the first volunteer message may be broadcast or multicast. The other components of the control and data message component 805 are discussed infra.

The ACK determination component 806 may be configured to determine whether one or more received ACKs (received via the reception component 804) are in response to the first volunteer message (e.g., are intended for the apparatus 802) based on at least one of: an explicit indication of an identifier of the intended recipient (e.g., apparatus 802) in the one or more ACKs, or time and frequency resources on which the one or more ACKs are received. The apparatus 802 may receive (via the reception component 804) various ACKs transmitted by various other devices. Some of such received ACKs may be intended for the apparatus 802 (e.g., in response to the first volunteer message transmitted by the apparatus 802) while some of the ACKs may be intended for others. Based on the implicit or explicit indication in a received ACK, the ACK determination component 806 may determine whether the received ACK is intended for the apparatus 802 or another UE. The ACK determination component 806 may be further configured to determine a total number (e.g., a first number ) of ACKs received in response to the first volunteer message, and a number of ACKs received for other devices.

The determination component 808 may be configured to determine whether the apparatus 802 is to become the head of the group based on a first number of ACKs received in response to the first volunteer message. For example, in one configuration, the determination component 808 may be configured to determine, for the apparatus 802, to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than or equal to a threshold number. In one configuration, the determination component 808 may be configured to determine, for the apparatus 802, to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the threshold number.

In some configurations, the determination component 808 may be configured to determine whether the apparatus 802 is to become the head of the group further based on a second number of ACKs received by at least one other UE in response to a second volunteer message transmitted by the at least one other UE. For example, in one configuration, the determination component 808 may be configured to determine, for the apparatus 802, to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than the second number of ACKs (e.g., received in response to the second volunteer message) . In one configuration, the determination component 808 may be further configured to determine, for the apparatus 802, to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the second number of ACKs.

In one configuration, based on a determination (from the determination component 808) for the apparatus 802 to become the head of the group, the group message component 812 may generate and transmit (e.g., via the transmission component 818) to transmit a group message (e.g., a first type of control message transmitted by the apparatus 802 as an individual node) including information indicating the apparatus 802 is the head of the group. In an example, where the group may already exist and the apparatus 802 is determined to become the head (e.g., based on the criteria discussed above) , the group message may further indicate replacement of a prior head of the group with the apparatus 802 as the new head of the group. In another example, where the group does not exist and the apparatus 802 intends to form the group and become the head, the group message may further include information indicating formation of the group (e.g., an announcement that the apparatus 802 has formed the group and is the head of the group) . In some such configurations, the first volunteer message transmitted by the apparatus 802 may further indicate a request/intention to form the group.

The quit message component 816 may be configured to generate and transmit (e.g., via the transmission component 818) a quit message indicating an intention to quit as the head of the group. The quit message may be broadcast to members and non-members of the group, or may be just multicast to group members in some configurations.

In various configurations, in response to the quit message transmitted by the apparatus 802 indicating that a new group head may be needed and the intention of the apparatus to quit as the head of the group, one or more UEs may volunteer to become the head and may each transmit a volunteer message (e.g., a second volunteer message) . The volunteer message component 814 may be further configured to receive (e.g., via the reception component 804) and process such volunteer messages. For example, the volunteer message component 814 may be further configured to receive (e.g., via the reception component 804) and process a second volunteer message from the one or more UEs, e.g., in response to the quit message.

The selection component 810 may be configured to select a new head of the group from the one or more UEs, e.g., the UEs that may have transmitted the second volunteer message. In some configurations, the selection component 810 may be further configured to select the new head based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs as discussed supra (e.g., in connection with FIG. 4B and flowchart 700) .

In some configurations, under the control and/or in coordination with the quit message component 816, the reception component 804 may be configured to monitor for the second volunteer message for a predetermined time period. In one configuration, when no volunteer message is received in response to the quit message within the predetermined time period, the volunteer message component 814 may control the reception component 804 to monitor for the second volunteer message (e.g., in response to the quit message) from one or more UEs for an extended time period. In some configurations, when no volunteer message is received in response to the quit message within the predetermined time period, the control component 817 may dismiss the group. For example, dismissing the group may include that the control component 817 generate and transmit (e.g., via the transmission component 818) a dismiss message indicating that the group has been dismissed/dissolved.

The transmission component 818 may be configured to transmit messages and/or other information to one or more external devices including, e.g., UE 850. In some configurations, the transmission component 818 may operate in combination with and/or under the control of one or more component of the apparatus 802 (e.g., such as the control component 817 and/or the control and data message component 805. The messages/information may be transmitted by the transmission component 812 in accordance with the methods discussed supra including the method of flowchart 700. For example, various first type and/or second type control and data messages discussed supra may be transmitted via the transmission component 818.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowchart of FIG. 7. As such, each block in the aforementioned flowchart of FIG. 7 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 9 is a diagram 900 illustrating an example of a hardware implementation for an apparatus 802'employing a processing system 914. The processing system 914 may be implemented with a bus architecture, represented generally by the bus 924. The bus 924 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 914 and the overall design constraints. The bus 924 links together various circuits including one or more processors and/or hardware components, represented by the processor 904, the

components

804, 805, 806, 808, 810, 812, 814, 816, 817, 818 and the computer-readable medium/memory 906. The bus 924 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system 914 may be coupled to a transceiver 910. The transceiver 910 is coupled to one or more antennas 920. The transceiver 910 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 910 receives a signal from the one or more antennas 920, extracts information from the received signal, and provides the extracted information to the processing system 914, specifically the reception component 804. In addition, the transceiver 910 receives information from the processing system 914, specifically the transmission component 818, and based on the received information, generates a signal to be applied to the one or more antennas 920. The processing system 914 includes a processor 904 coupled to a computer-readable medium/memory 906. The processor 904 is responsible for general processing, including the execution of software stored on the computer-readable medium/memory 906. The software, when executed by the processor 904, causes the processing system 914 to perform the various functions described supra for any particular apparatus. The computer-readable medium /memory 906 may also be used for storing data that is manipulated by the processor 904 when executing software. The processing system 914 further includes at least one of the

components

804, 805, 806, 808, 810, 812, 814, 816, 817, 818. The components may be software components running in the processor 904, resident/stored in the computer readable medium/memory 906, one or more hardware components coupled to the processor 904, or some combination thereof. In one configuration, the processing system 914 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359.

In a first configuration, the apparatus 802/802'may be a first UE for wireless communication including means for transmitting a first volunteer message indicating an intention to be a head of the group. The apparatus 802/802'may further comprise means for determining whether to become the head of the group based on a first number of acknowledgments (ACKs) received in response to the first volunteer message. In some configurations, the means for determining whether to become the head of the group may be configured to determine to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than or equal to a threshold number, and determine to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the threshold number.

In some configurations, determining whether to become the head of the group is further based on a second number of ACKs received by at least one other UE in response to a second volunteer message transmitted by the at least one other UE. In some such configurations, the means for determining whether to become the head of the group may be further configured to determine to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than the second number of ACKs, and determine to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the second number of ACKs.

In some configurations, the apparatus 802/802'may further comprise means for receiving one or more ACKs from one or more UEs. In some configurations, the apparatus 802/802'may further comprise means for determining that the one or more ACKs are in response to the first volunteer message based on at least one of: an explicit indication of an identifier of the first UE in the one or more ACKs, or time and frequency resources on which the one or more ACKs are received.

In some configurations, the first volunteer message further indicates a request to form the group. In some configurations, the means for determining whether to become the head of the group is configured to determine to become the head of the group. The apparatus may further comprise means for transmitting a first type of control message including information indicating formation of the group and that the first UE is the head of the group. In some configurations, the means for transmitting may be further configured to transmit a quit message indicating an intention to quit as the head of the group.

In some configurations, the apparatus 802/802'may further comprise means for receiving a second volunteer message from one or more UEs in response to the quit message. In some such configurations, the apparatus may further comprise means for selecting a new head of the group from the one or more UEs. In some configurations, the new head may be selected based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs. The one or more UEs may be existing members of the group or non-members. In some configurations, the apparatus may further comprises at least one of: means for monitoring for a second volunteer message from one or more UEs in response to the quit message for an extended time period when no volunteer message may be received in response to the quit message within a predetermined time period, or means for dismissing the group when no volunteer message may be received in response to the quit message within a predetermined time period.

The aforementioned means may be one or more of the aforementioned components of the apparatus 802 and/or the processing system 914 of the apparatus 802'configured to perform the functions recited by the aforementioned means. As described supra, in one configuration the processing system 914 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

Example 1 is a method of wireless communication at a first UE that includes transmitting a first volunteer message indicating an intention to be a head of a group, and determining whether to become the head of the group based on a first number of ACKs received in response to the first volunteer message.

In Example 2, the method of the example 1 further includes that the first UE comprises a first vehicle, and the first UE and the group are part of a V2V communication network.

In Example 3, the method of any of examples 1-2 further includes that the group comprises a platoon including the first vehicle and one or more other vehicles traveling together in a coordinated manner.

In Example 4, the method of any of examples 1-3 further includes that the first vehicle and the one or more other vehicles coordinate movement of the group via control messages and data messages.

In Example 5, the method of any of examples 1-4 further includes that determining whether to become the head of the group comprises: determining to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than or equal to a threshold number, and determining to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the threshold number.

In Example 6, the method of any of examples 1-5 further includes that the threshold number is preconfigured.

In Example 7, the method of any of examples 1-6 further includes that the threshold number is configured by the head of the group or a network node.

In Example 8, the method of any of examples 1-7 further includes that the determining whether to become the head of the group is further based on a second number of ACKs received by at least one other UE in response to a second volunteer message transmitted by the at least one other UE, determining to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than the second number of ACKs, and determining to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the second number of ACKs.

In Example 9, the method of any of examples 1-8 further includes that the predetermined time period is preconfigured, or indicated by a network node.

In Example 10, the method of any of examples 1-9 further includes receiving one or more ACKs from one or more UEs, and determining that the one or more ACKs are in response to the first volunteer message based on at least one of: an explicit indication of an identifier of the first UE in the one or more ACKs, or time and frequency resources on which the one or more ACKs are received.

In Example 11, the method of any of examples 1-10 further includes that the first volunteer message further indicates a request to form the group, that determining whether to become the head of the group comprises determining to become the head of the group, and transmitting a first type of control message including information indicating formation of the group and that the first UE is the head of the group.

In Example 12, the method of any of examples 1-11 further includes transmitting a quit message indicating an intention to quit as the head of the group.

In Example 13, the method of any of examples 1-12 further includes receiving a second volunteer message from one or more UEs in response to the quit message, and selecting a new head of the group from the one or more UEs.

In Example 14, the method of any of examples 1-13 further includes that the new head is selected based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs.

In Example 15, the method of any of examples 1-14 further includes that the one or more UEs are existing members of the group or non-members of the group.

In Example 16, the method of any of examples 1-15 further includes performing at least one of: monitoring for a second volunteer message from one or more UEs in response to the quit message for an extended time period or dismissing the group when no volunteer message is received in response to the quit message within a predetermined time period.

In Example 17, the method of any of examples 1-16 further includes receiving one or more ACKs from one or more UEs in response to the first volunteer message, and replacing a prior head of the group to become the head of the group.

In Example 18, the method of any of examples 1-17 further includes that the messages between the first UE and one or more other UEs comprise control messages and data messages, that the control messages comprise a first type of control message transmitted by individual UEs and a second type of control message transmitted by the head to the group, and that the data messages comprise a first type of data message transmitted by the individual UEs, and a second type of data message transmitted by the head to the group.

In Example 19, the method of any of examples 1-18 further includes that the first type of control message indicates at least one of an indication to form the group, an indication to be the head of the group, transmission resources for the first type of data message, and transmission parameters for the first type of data message.

In Example 20, the method of any of examples 1-19 further includes that the transmission resources for the first type of data message comprises one or more of time, frequency and spatial resources, and that the transmission parameters for the first type of data message comprise one or more of a modulation and coding scheme (MCS) , a new data indicator, and a retransmission indicator.

In Example 21, the method of any of examples 1-20 further includes that the second type of control message indicates one or more of a group identifier of the group, transmission resources for the second type of data message, transmission parameters for the second type of data message, and a hybrid automatic repeat request (HARQ) resource indicator.

In Example 22, the method of any of examples 1-21 further includes that the transmission resources for the second type of data message comprises one or more of time, frequency and spatial resources, and that the transmission parameters comprise one or more of a MCS, and a retransmission indicator.

In Example 23, the method of any of examples 1-22 further includes that the first type of data message comprises information indicating one or more of: speed of the first UE, direction of the first UE, position of the first UE, a group identifier for the group when the first UE is requesting to join the group, and an ACK to a group head.

In Example 24, the method of any of examples 1-23 further includes that the second type of data message indicates at least one of: a need for a new group head, a group identifier, a speed for the group, a direction for the group, positioning for the group, a brake instruction, an accelerate instruction, an acceptance of a request to join the group, an identifier for at least one group member, a number of members in the group, and a route for the group.

Example 25 is a system or apparatus including means for implementing a method or realizing an apparatus as in any of examples 1-24.

Example 26 is a device including one or more processors and memory in electronic communication with the one or more processors storing instructions executable by the one or more processors to cause the system or apparatus to implement a method as in any of examples 1-24.

Example 27 is a non-transitory computer readable medium storing instructions executable by one or more processors to cause the one or more processors to implement a method as in any of examples 1-24.

While some specific examples are discussed above, it should be appreciated that many variations are possible. The features discussed in the above examples 1-39 may also be used in combination with any of the other aspects and/or features discussed herein.

It is understood that the specific order or hierarchy of blocks in the processes /flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”

Claims

A method of forming a group at a first user equipment (UE) , comprising:

transmitting a first volunteer message indicating an intention to be a head of the group; and

determining whether to become the head of the group based on a first number of acknowledgments (ACKs) received in response to the first volunteer message.
The method of claim 1, wherein the first UE comprises a first vehicle; and

wherein the first UE and the group are part of a vehicle-to-vehicle (V2V) communication network.
The method of claim 2, wherein the group comprises a platoon including the first vehicle and one or more other vehicles traveling together in a coordinated manner.
The method of claim 3, wherein the first vehicle and the one or more other vehicles coordinate movement of the group via control messages and data messages.
The method of claim 1, wherein determining whether to become the head of the group comprises:

determining to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than or equal to a threshold number; and

determining to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the threshold number.
The method of claim 5, wherein the threshold number is preconfigured.
The method of claim 5, wherein the threshold number is configured by the head of the group or a network node.
The method of claim 1, wherein determining whether to become the head of the group is further based on a second number of ACKs received by at least one other UE in response to a second volunteer message transmitted by the at least one other UE, the method further comprising:

determining to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than the second number of ACKs; and

determining to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the second number of ACKs.
The method of claim 5, wherein the predetermined time period is preconfigured, or indicated by a network node.
The method of claim 1, further comprising:

receiving one or more ACKs from one or more UEs; and

determining that the one or more ACKs are in response to the first volunteer message based on at least one of: an explicit indication of an identifier of the first UE in the one or more ACKs, or time and frequency resources on which the one or more ACKs are received.
The method of claim 1, wherein the first volunteer message further indicates a request to form the group, the method further comprising:

wherein determining whether to become the head of the group comprises determining to become the head of the group; and

transmitting a first type of control message including information indicating formation of the group and that the first UE is the head of the group.
The method of claim 11, further comprising:

transmitting a quit message indicating an intention to quit as the head of the group.
The method of claim 12, further comprising:

receiving a second volunteer message from one or more UEs in response to the quit message; and

selecting a new head of the group from the one or more UEs.
The method of claim 13, wherein the new head is selected based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs.
The method of claim 13, wherein the one or more UEs are existing members of the group.
The method of claim 13, wherein the one or more UEs are not existing members of the group.
The method of claim 12, further comprising:

when no volunteer message is received in response to the quit message within a predetermined time period, performing at least one of:

monitoring for a second volunteer message from one or more UEs in response to the quit message for an extended time period, or dismissing the group.
The method of claim 1, further comprising:

receiving one or more ACKs from one or more UEs in response to the first volunteer message; and

replacing a prior head of the group to become the head of the group.
The method of claim 1, wherein messages between the first UE and one or more other UEs comprise control messages and data messages;

wherein the control messages comprise a first type of control message transmitted by individual UEs, and a second type of control message transmitted by the head to the group; and

wherein the data messages comprise a first type of data message transmitted by the individual UEs, and a second type of data message transmitted by the head to the group.
The method of claim 19, wherein the first type of control message indicates at least one of an indication to form the group, an indication to be the head of the group, transmission resources for the first type of data message, and transmission parameters for the first type of data message.
The method of claim 20, wherein the transmission resources for the first type of data message comprises one or more of time, frequency and spatial resources, and

wherein the transmission parameters for the first type of data message comprise one or more of a modulation and coding scheme (MCS) , a new data indicator, and a retransmission indicator.
The method of claim 19, wherein the second type of control message indicates one or more of a group identifier of the group, transmission resources for the second type of data message, transmission parameters for the second type of data message, and a hybrid automatic repeat request (HARQ) resource indicator.
The method of claim 22, wherein the transmission resources for the second type of data message comprises one or more of time, frequency and spatial resources, and

wherein the transmission parameters comprise one or more of a modulation and coding scheme (MCS) , and a retransmission indicator.
The method of claim 19, wherein the first type of data message comprises information indicating one or more of: speed of the first UE, direction of the first UE, position of the first UE, a group identifier for the group when the first UE is requesting to join the group, and an ACK to a group head.
The method of claim 19, wherein the second type of data message indicates at least one of: a need for a new group head, a group identifier, a speed for the group, a direction for the group, positioning for the group, a brake instruction, an accelerate instruction, an acceptance of a request to join the group, an identifier for at least one group member, a number of members in the group, and a route for the group.
A first user equipment (UE) for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

transmit a first volunteer message indicating an intention to be a head of a group; and

determine whether to become the head of the group based on a first number of acknowledgments (ACKs) received in response to the first volunteer message.
The first UE of claim 26, wherein the first UE comprises a first vehicle; and

wherein the first UE and the group are part of a vehicle-to-vehicle (V2V) communication network.
The first UE of claim 27, wherein the group comprises a platoon including the first vehicle and one or more other vehicles traveling together in a coordinated manner.
The first UE of claim 28, wherein the first vehicle and the one or more other vehicles coordinate movement of the group via control messages and data messages.
The first UE of claim 26, wherein the at least one processor is further configured, as part of being configured to determine whether to become the head of the group, to:

determine to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than or equal to a threshold number; and

determine to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the threshold number.
The first UE of claim 30, wherein the threshold number is preconfigured.
The first UE of claim 30, wherein the threshold number is configured by the head of the group or a network node.
The first UE of claim 26, wherein the at least one processor is configured to determine whether to become the head of the group further based on a second number of ACKs received by at least one other UE in response to a second volunteer message transmitted by the at least one other UE, the at least one processor being further configured to:

determine to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than the second number of ACKs; and

determine to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the second number of ACKs.
The first UE of claim 30, wherein the predetermined time period is preconfigured, or indicated by a network node.
The first UE of claim 26, wherein the at least one processor is configured to:

receive one or more ACKs from one or more UEs; and

determine that the one or more ACKs are in response to the first volunteer message based on at least one of: an explicit indication of an identifier of the first UE in the one or more ACKs, or time and frequency resources on which the one or more ACKs are received.
The first UE of claim 26, wherein the first volunteer message further indicates a request to form the group, and

wherein the at least one processor is further configured to:

determine to become the head of the group; and

transmit a first type of control message including information indicating formation of the group and that the first UE is the head of the group.
The first UE of claim 36, wherein the at least one processor is further configured to:

transmit a quit message indicating an intention to quit as the head of the group.
The first UE of claim 37, wherein the at least one processor is further configured to:

receive a second volunteer message from one or more UEs in response to the quit message; and

select a new head of the group from the one or more UEs.
The first UE of claim 38, wherein the new head is selected based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs.
The first UE of claim 38, wherein the one or more UEs are existing members of the group.
The first UE of claim 38, wherein the one or more UEs are not existing members of the group.
The first UE of claim 37, wherein the at least one processor is further configured to perform at least one of:

monitor for a second volunteer message from one or more UEs in response to the quit message for an extended time period, or dismiss the group, when no volunteer message is received in response to the quit message within a predetermined time period.
The first UE of claim 26, wherein the at least one processor is further configured to:

receive one or more ACKs from one or more UEs in response to the first volunteer message; and

replace a prior head of the group to become the head of the group.
The first UE of claim 26, wherein messages between the first UE and one or more other UEs comprise control messages and data messages;

wherein the control messages comprise a first type of control message transmitted by individual UEs, and a second type of control message transmitted by the head to the group; and

wherein the data messages comprise a first type of data message transmitted by the individual UEs, and a second type of data message transmitted by the head to the group.
The first UE of claim 44, wherein the first type of control message indicates at least one of an indication to form the group, an indication to be the head of the group, transmission resources for the first type of data message, and transmission parameters for the first type of data message.
A first UE for wireless communication, comprising:

means for transmitting a first volunteer message indicating an intention to be a head of a group; and

means for determining whether to become the head of the group based on a first number of acknowledgments (ACKs) received in response to the first volunteer message.
The first UE of claim 46, wherein the first UE comprises a first vehicle; and

wherein the first UE and the group are part of a vehicle-to-vehicle (V2V) communication network.
The first UE of claim 47, wherein the group comprises a platoon including the first vehicle and one or more other vehicles traveling together in a coordinated manner.
The first UE of claim 48, wherein the first vehicle and the one or more other vehicles coordinate movement of the group via control messages and data messages.
The first UE of claim 46, wherein the means for determining whether to become the head of the group is configured to:

determine to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than or equal to a threshold number; and

determine to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the threshold number.
The first UE of claim 50, wherein the threshold number is preconfigured.
The first UE of claim 50, wherein the threshold number is configured by the head of the group or a network node.
The first UE of claim 46, wherein determining whether to become the head of the group is further based on a second number of ACKs received by at least one other UE in response to a second volunteer message transmitted by the at least one other UE,

wherein the means for determining whether to become the head of the group is further configured to:

determine to become the head of the group when the first number of ACKs received in response to the first volunteer message within a predetermined time period is greater than the second number of ACKs; and

determine to not become the head when the first number of ACKs received in response to the first volunteer message within the predetermined time period is less than the second number of ACKs.
The first UE of claim 50, wherein the predetermined time period is preconfigured, or indicated by a network node.
The first UE of claim 46, further comprising:

means for receiving one or more ACKs from one or more UEs; and

means for determining that the one or more ACKs are in response to the first volunteer message based on at least one of: an explicit indication of an identifier of the first UE in the one or more ACKs, or time and frequency resources on which the one or more ACKs are received.
The first UE of claim 46, wherein the first volunteer message further indicates a request to form the group;

wherein the means for determining whether to become the head of the group is configured to determine to become the head of the group; and

wherein the first UE further comprises means for transmitting a first type of control message including information indicating formation of the group and that the first UE is the head of the group.
The first UE of claim 56, further comprising:

wherein the means for transmitting is further configured to transmit a quit message indicating an intention to quit as the head of the group.
The first UE of claim 57, further comprising:

means for receiving a second volunteer message from one or more UEs in response to the quit message; and

means for selecting a new head of the group from the one or more UEs.
The first UE of claim 58, wherein the new head is selected based on a corresponding number of ACKs received, within a predetermined time period, in response to the second volunteer message transmitted by each of the one or more UEs.
The first UE of claim 58, wherein the one or more UEs are existing members of the group.
The first UE of claim 58, wherein the one or more UEs are not existing members of the group.
The first UE of claim 57, further comprising at least one of:

means for monitoring for a second volunteer message from one or more UEs in response to the quit message for an extended time period when no volunteer message is received in response to the quit message within a predetermined time period, or

means for dismissing the group when no volunteer message is received in response to the quit message within the predetermined time period.
The first UE of claim 46, wherein messages between the first UE and one or more other UEs comprise control messages and data messages;

wherein the control messages comprise a first type of control message transmitted by individual UEs, and a second type of control message transmitted by the head to the group; and

wherein the data messages comprise a first type of data message transmitted by the individual UEs, and a second type of data message transmitted by the head to the group.
The first UE of claim 63, wherein the first type of control message indicates at least one of an indication to form the group, an indication to be the head of the group, transmission resources for the first type of data message, and transmission parameters for the first type of data message.
The first UE of claim 64, wherein the transmission resources for the first type of data message comprises one or more of time, frequency and spatial resources, and

wherein the transmission parameters for the first type of data message comprise one or more of a modulation and coding scheme (MCS) , a new data indicator, and a retransmission indicator.
A computer-readable medium of a first UE, the computer-readable medium storing computer executable code, comprising code to:

transmit a first volunteer message indicating an intention to be a head of a group; and

determine whether to become the head of the group based on a first number of acknowledgments (ACKs) received in response to the first volunteer message.