Methods and apparatus for sidelink positioning implemented by a ue

Abstract

Independent ranging sessions initiated by multiple initiator user equipments (UEs) are monitored and combined into a single combined ranging session to reduce overhead. A UE monitors a first set of ranging sessions initiated by a first initiator UE, the first set of ranging sessions including a pre-range message identifying UEs in the first set of ranging sessions, and monitors a second set of ranging sessions initiated by a second initiator UE, the second set of ranging sessions including a pre-range message identifying UEs in the second set of ranging sessions. The UE initiates a third set of ranging sessions by broadcasting a pre-range message identifying UEs in the third set of ranging sessions, the third set of ranging sessions including UEs in the first set of ranging sessions and UEs in the second set of ranging sessions. The original initiator UEs terminate initiation of their ranging sessions upon receiving the pre-range message initiating the third set of ranging sessions.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. nonprovisional application No. 17 / 184,429, filed February 24, 2021, entitled “DYNAMIC MERGE AND SEPARATION OF RANGING SESSIONS IN UE-ENABLED SIDELINK POSITIONING”, which has been assigned to the assignee of this application and is expressly incorporated herein by reference in its entirety.

[0003] background Background Technology

[0004] The subject matter disclosed herein relates to wireless communication systems, and more particularly to methods and apparatus for ranging or locating user equipment in distributed wireless communication systems.

[0005] Relevant background

[0006] Obtaining accurate location information for user equipment (such as cellular phones or other wireless communication devices) is becoming increasingly common in the communications industry. For example, obtaining highly accurate locations of vehicles or pedestrians is crucial for autonomous vehicle driving and pedestrian safety applications.

[0007] One common method for determining device location is using a satellite positioning system (SPS), such as the well-known Global Positioning Satellite (GPS) or Global Navigation Satellite System (GNSS), which employs several satellites in orbit around the Earth. However, in some scenarios, location determination signals from SPS can be unreliable or unavailable, for example, during adverse weather conditions or in areas with poor satellite signal reception (such as tunnels or parking lots). Furthermore, location information generated using SPS is prone to inaccuracy. For example, readily available GPS positioning devices have an accuracy of only a few meters, which is not optimal for ensuring safe autonomous driving and navigation.

[0008] Coordination or autonomous driving requires communication between vehicles, which can be direct or indirect (e.g., via infrastructure components such as roadside units (RSUs)). For vehicle safety applications, both positioning and ranging are crucial. For example, vehicle user equipment (UEs) can use sidelink signaling to perform positioning and ranging, such as broadcasting ranging signals to allow other vehicle UEs or pedestrian UEs to determine the relative position of the transmitter. Accurate and timely knowledge of the relative position or distance to nearby vehicles enables autonomous vehicles to safely maneuver and negotiate traffic conditions. For example, round-trip time (RTT) is a technique commonly used to determine the distance between transmitters. RTT is a two-way messaging technique where the time (minus processing delay) between the first device sending a ranging signal and the second device receiving acknowledgment (e.g., in the form of a returned ranging signal) corresponds to the distance between the two devices.

[0009] Ranging sessions in a distributed system (i.e., without infrastructure support for coordinated message passing) can lead to multiple simultaneous ranging sessions, potentially involving overlapping sets of participating UEs. Each ranging session may include multiple messages and ranging signals exchanged between participating UEs, and each ranging session may include multiple participating UEs. Consequently, with multiple ranging sessions occurring simultaneously, signaling overhead can become excessive and may disrupt UE ranging and positioning.

[0010] Overview

[0011] Independent ranging sessions initiated by multiple initiating user equipment (UEs) are monitored and combined into a single combined ranging session to reduce overhead. Independent ranging sessions can be monitored over time periods based on the speed of the initiating UE; for example, the monitoring period can be longer for a lower speed of the initiating UE. The combined ranging session can be initiated by responding UEs from individual ranging sessions and includes all UEs participating in those individual ranging sessions. The combined ranging session can be executed for a period of time, which can also be based on the speed of the initiating UE; for example, the duration of the combined ranging session can be longer for a lower speed of the initiating UE.

[0012] In one implementation, a ranging method performed by a first UE in a distributed user equipment (UE) system includes: monitoring a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; monitoring a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and initiating a third ranging session set by broadcasting a third plurality of pre-ranging messages identifying UEs in a third ranging session set, the third ranging session set including UEs in the first ranging session set and UEs in the second ranging session set.

[0013] In one implementation, a first UE configured to perform ranging in a distributed user equipment (UE) system includes: a radio transceiver configured to wirelessly communicate with entities in a wireless network; at least one memory; and at least one processor coupled to the radio transceiver and the at least one memory, wherein the at least one processor is configured to: monitor a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; monitor a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and initiate a third ranging session set by being configured to broadcast a third plurality of pre-ranging messages via the radio transceiver identifying UEs in a third ranging session set, the third ranging session set including UEs in the first ranging session set and UEs in the second ranging session set.

[0014] In one implementation, a first UE configured to perform ranging in a distributed user equipment (UE) system includes: means for monitoring a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; means for monitoring a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and means for initiating a third ranging session set by broadcasting a third plurality of pre-ranging messages identifying UEs in a third ranging session set, the third ranging session set including UEs in the first ranging session set and UEs in the second ranging session set.

[0015] In one implementation, a non-transient storage medium includes program code stored thereon, the program code being operable to configure at least one processor in a first user equipment (UE) for ranging in a distributed UE system, the program code including instructions for: monitoring a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; monitoring a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and initiating a third ranging session set by broadcasting a third plurality of pre-ranging messages identifying UEs in a third ranging session set, the third ranging session set including UEs in the first ranging session set and UEs in the second ranging session set.

[0016] In one implementation, a ranging method performed by a first UE in a distributed user equipment (UE) system includes: initiating a first ranging session set by broadcasting a first pre-ranging message identifying the first UE and a first plurality of responding UEs in each ranging session of a first set containing the first ranging session; receiving from a second UE a second pre-ranging message for initiating a second ranging session set, the second pre-ranging message from the second UE identifying the second UE and the second plurality of responding UEs in the second ranging session, the second plurality of responding UEs including the first UE, a third UE initiating a third ranging session set, and responding UEs from the first ranging session set and the third ranging session set; and terminating the initiation of the first ranging session set in response to receiving one of the second pre-ranging message from the second UE for initiating the second ranging session set.

[0017] In one implementation, a first UE configured to perform ranging in a distributed user equipment (UE) system includes: a radio transceiver configured to wirelessly communicate with entities in a wireless network; at least one memory; and at least one processor coupled to the radio transceiver and the at least one memory, wherein the at least one processor is configured to: initiate a first ranging session set by broadcasting a first pre-ranging message identifying the first UE and a first plurality of responding UEs in each ranging session of a first set including a first ranging session; receive from a second UE a second pre-ranging message for initiating a second ranging session set, the second pre-ranging message from the second UE identifying the second UE and the second plurality of responding UEs in the second ranging session, the second plurality of responding UEs including the first UE, a third UE initiating a third ranging session set, and responding UEs from the first ranging session set and the third ranging session set; and terminate the initiation of the first ranging session set in response to receiving one of the second pre-ranging message from the second UE for initiating the second ranging session set.

[0018] In one implementation, a first UE configured to perform ranging in a distributed user equipment (UE) system includes: means for initiating a first ranging session set by broadcasting a first pre-ranging message identifying the first UE and a first plurality of responding UEs in each ranging session of a first set containing a first ranging session; means for receiving from a second UE a second pre-ranging message for initiating a second ranging session set, the second pre-ranging message from the second UE identifying the second UE and the second plurality of responding UEs in the second ranging session, the second plurality of responding UEs including the first UE, a third UE initiating a third ranging session set, and responding UEs from the first ranging session set and the third ranging session set; and means for terminating the initiation of the first ranging session set in response to receiving one of the second pre-ranging messages from the second UE for initiating the second ranging session set.

[0019] In one implementation, a non-transient storage medium includes program code stored thereon, the program code being operable to configure at least one processor in a first user equipment (UE) for ranging in a distributed UE system, the program code including instructions for: initiating a first ranging session set by broadcasting a first pre-ranging message identifying a first UE and a first plurality of responding UEs in each ranging session of a first set containing a first ranging session; receiving from a second UE a second pre-ranging message for initiating a second ranging session set, the second pre-ranging message from the second UE identifying a second UE and a second plurality of responding UEs in the second ranging session, the second plurality of responding UEs including the first UE, a third UE initiating a third ranging session set, and responding UEs from the first ranging session set and the third ranging session set; and terminating the initiation of the first ranging session set in response to receiving one of the second pre-ranging message from the second UE for initiating the second ranging session set. Brief description of the attached diagram

[0021] Non-limiting and non-exhaustive aspects are described with reference to the following figures, wherein, unless otherwise specified, similar reference numerals are used throughout the figures to refer to similar parts.

[0022] Figure 1 The explanation illustrates a wireless communication system with distributed communication, which includes ranging signaling for supporting multiple ranging sessions and / or positioning.

[0023] Figure 2 The signaling diagram explains the timing and frequency of various messages used in a ranging or positioning session that can be sent and received by the initiating UE and three responding UEs.

[0024] Figure 3 The illustration shows two individual ranging sessions that are combined into a single combined ranging session, which includes all participating UEs from the individual ranging sessions.

[0025] Figure 4 A schematic block diagram illustrating certain exemplary features of a UE configured to combine independent ranging sessions into a single ranging session is shown.

[0026] Figure 5 This is a flowchart explaining the method of ranging between UEs.

[0027] Figure 6 This is a flowchart explaining the method of ranging between UEs.

[0028] Detailed description

[0029] Distributed approaches can be used for ranging and locating vehicles, roadside units (RSUs), and pedestrians, avoiding the need for centralized base station coordination and relay communication. This communication can be used in applications such as autonomous driving and vehicle safety. Communication used in distributed approaches can occur, for example, between vehicles or directly between vehicles and RSUs or pedestrians. These communications can include message and information elements (IEs), which vehicles can use to provide the information needed for autonomous driving.

[0030] For example, for the safe operation of autonomous vehicles, it is necessary to determine their relative position or distance to other vehicles. Various methods can be used to derive the relative position between vehicles. For instance, ranging signaling can be used to derive the relative position of vehicles. Ranging signals are sometimes referred to as physical ranging signals, positioning ranging signals, positioning reference signals, or physical reference signals, and are collectively referred to herein as PRS signals. PRS signals can be broadcast, for example, by the user equipment (UE) (sometimes referred to as V-UE) in the vehicle and received by other V-UEs and / or infrastructure (e.g., RSU) or pedestrian-held UEs using direct communication systems such as Dedicated Short Range Communication (DSRC), Cellular Vehicle-to-Everything (C-V2X) communication, and even 5G New Radio (NR) communication. PRS signals are used to determine the distance to the broadcasting vehicle, for example, using one-way ranging, round-trip time (RTT) positioning operations, or other standard positioning operations such as Time of Arrival (TOA), Time Difference of Arrival (TDOA), or Observed Time Difference of Arrival (OTDOA) operations.

[0031] In a distributed system, individual UEs can use messages and location signals directly transmitted to other UEs to perform ranging relative to other nearby UEs. In an RTT-based ranging session, for example, each UE transmits and receives multiple messages and signals. For example, an initial set of pre-ranging signal messages (PRS messages) is transmitted and received to request and accept a ranging session, followed by broadcasting a ranging signal (PRS signal) for measurement, and then exchanging a set of post-ranging signal messages (PRS messages) with measurement payloads. For RTT-based ranging and positioning, for example, the time of arrival (TOA) and departure time (TOD) measurements of the transmitted and received PRS signals can be provided in the PRS messages and used by each UE pair to determine the distance between UEs. PRS messages and PRS messages can be transmitted on licensed spectrum to ensure reliability, while PRS signals can be broadcast on unlicensed spectrum (e.g., to enjoy greater available bandwidth in, for example, the UNI-III spectrum).

[0032] The distributed mechanism ensures minimal overhead, but multiple nearby UEs may initiate separate ranging sessions independently. Therefore, multiple uncoordinated ranging sessions can be initiated autonomously by individual UEs. For example, without overhead communication to control the ranging session, multiple UEs can separately broadcast their own pre-PRS signals to the same set of responding UEs, resulting in two independent ranging sessions involving the same responding UEs and occurring simultaneously. For instance, multiple V-UEs can initiate separate ranging sessions with the same set of RSUs. Furthermore, UEs held by nearby pedestrians can also initiate ranging sessions with the same set of RSUs. The number of messages exchanged in each individual ranging session can be large, especially with several responding UEs present. Additionally, some signaling (such as PRS signals) can be broadcast on unlicensed spectrum, which may be delayed due to the Listen-Before-Broadcast (LBT) protocol used with unlicensed spectrum. Accordingly, significant overhead can exist when multiple overlapping ranging sessions exist. For example, overhead can disrupt ranging and positioning within a session due to additional delays in received signaling.

[0033] Therefore, in implementation, as discussed herein, a UE (such as an RSU or other anchor UE) can monitor multiple ranging session sets initiated by different initiating UEs, where each ranging session set includes a broadcast pre-ranging message identifying the UEs participating in each ranging session set. A UE can take over these ranging sessions by initiating its own combined ranging session by broadcasting a pre-ranging message including all UEs participating in the monitored ranging sessions. Each original initiating UE can terminate the initiation of the ranging session when it is included in the combined ranging session and will participate as a responding UE, for example, by terminating the broadcast pre-ranging signal. For example, the original ranging session may be monitored by the UE for a time period T1 before the UE initiates the combined ranging session. Furthermore, the UE can continue to initiate combined ranging sessions for a time period T2. For example, the lengths of time periods T1 and T2 may be based on the speed of the original initiating UE. For example, if the speed of the original initiating UE is relatively high, the time period T1 may be relatively short, and if the speed of the original initiating UE is relatively low, the time period T1 may be relatively long. Similarly, if the original initiating UE has a relatively high speed, the time period T2 can be relatively short, and if the original initiating UE has a relatively low speed, the time period T2 can be relatively long. An indication of the time period T2 can be sent to the original initiating UEs (e.g., in the PRS pre-message of the combined ranging session) so that these original initiating UEs know when they can start initiating their own separate ranging sessions again.

[0034] Figure 1The wireless communication system 100 describes distributed communication, including ranging signaling as described herein to support multiple ranging sessions and / or positioning. The wireless communication system 100 describes a first vehicle 102 having a first wireless device (e.g., V-UE 102) that wirelessly communicates with another V-UE 104 (described as a second vehicle). V-UE 102 and V-UE 104 may include, but are not limited to, on-board units (OBUs), vehicles or their subsystems, or various other communication devices. V-UE 102 and 104 operate on behalf of their associated vehicles and provide communication; therefore, they may sometimes be simply referred to herein as vehicles 102 and 104 or UE 102 and 104. The first UE 102 and the second UE 104 may, for example, be two vehicles traveling on a road together with other vehicles not described.

[0035] The wireless communication system 100 may use, for example, vehicle-to-everything (V2X) communication standards, in which information is transferred between vehicles and other entities within the wireless communication network. V2X services include, for example, services for vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I), and vehicle-to-network (V2N). V2X standards are designed to develop autonomous or semi-autonomous driving systems (such as Advanced Driver Assistance Systems (ADAS)) that assist drivers in making critical decisions (such as lane changes, gear shifts, and overtaking speeds) and can be used to assist parking, as discussed herein. Low latency communication is used in V2X and is therefore suitable for precise relative positioning, for example, using ranging signals (such as one-way ranging, RTT, TDOA, etc.).

[0036] Generally, there are two operating modes for V2X services, as defined in 3GPP TS23.285. One operating mode uses direct wireless communication between V2X entities, sometimes referred to as sidelink communication. The other operating mode uses network-based wireless communication between entities. These two operating modes can be combined, or other operating modes can be used if needed.

[0037] The wireless communication system 100 can operate using direct or indirect wireless communication between UE 102 and UE 104. For example, wireless communication can be via a proximity-based service (ProSe) direct communication (PC5) reference point as defined in 3GPP TS 23.303, and can be via wireless communication according to IEEE 1609, on-vehicle environment radio access (WAVE), intelligent transportation systems (ITS), and IEEE 802.11p, on the 5.9 GHz ITS band, or other direct wireless connections between entities. Therefore, as explained, UE 102 and UE 104 can communicate directly using vehicle-to-vehicle (V2V) communication link 103. Similarly, UE 102 and UE 104 can communicate directly with roadside unit (RSU) 110 via vehicle-to-infrastructure (V2I) communication links 107 and 109, respectively. RSU 110 may include a backhaul connection to the network as explained by wired connection 111, but may also be connected to a base station via a wireless Uu interface. RSU 110 may be, for example, a fixed infrastructure entity that supports V2X applications and can exchange messages with other entities that support V2X applications. An RSU may be a logical entity that combines V2X application logic with the functionality of a base station in the RAN, such as an eNB, ng-eNB, or eLTE (referred to as an eNB-type RSU), or a gNB, or a UE (referred to as a UE-type RSU). RSU 110 may be used in conjunction with UE 102, 104, or other UEs for ranging, and because the location of RSU 110 can be precisely known, RSU 110 can be used as an anchor UE to determine the location of UE 102, 104, or other UEs. RSU 110 may sometimes be referred to herein as UE 110. UE 102, 104, and UE 110 may communicate with additional entities (such as additional vehicles, RSUs) using direct communication links, or with UE 112 held by pedestrian 114. For example, UE 102 can communicate with UE 112 via V2V communication link 113, UE 104 can communicate with UE 112 via V2V communication link 115, and UE 110 can communicate with UE 112 via V2I communication link 117.

[0038] During direct communication with one or more entities in the V2X wireless communication system 100, each entity may provide V2X information in messages, such as the identifier of the V2X entity and other information, such as Common Awareness Messages (CAM) and Decentralized Notification Messages (DENM) or Basic Security Messages (BSM), which may be used for, for example, ADAS or security use cases.

[0039] In other implementations, UE 102 and UE 104 may communicate indirectly with each other, for example, via V2I communication links 107 and 109 through RSU 110 or via other network infrastructure (not shown), for example, using cellular vehicle-to-everything (CV2X). For example, vehicles may communicate via base stations in a radio access network (RAN), such as evolved B-nodes (eNBs) in LTE radio access and / or evolved LTE (eLTE) radio access or next-generation evolved B-nodes (ng-eNBs) and / or NR B-nodes (gNBs) in fifth-generation (5G) radio access.

[0040] UEs 102 and 104 can initiate and perform ranging / location sessions, including sending pre-PRS messages, broadcasting PRS, and sending post-PRS messages on links 103, 107, 109, 113, or 115. These messages can be used to determine the distance or relative position between UEs 102 and 104. The PRS broadcast by UEs 102 and 104 can be any signal suitable for ranging, such as those defined for DSRC or C-V2X. PRS can be broadcast on licensed or unlicensed spectrum. For example, in some implementations, PRS can be broadcast on one or more unlicensed National Information Infrastructure (UNII) radio bands, including, for example, one or more of the UNII-1, UNII-2A, UNII-2B, or UNII-3 radio bands. When broadcasting on unlicensed spectrum, a Listen-Before-Broadcast (LBT) protocol can be used.

[0041] When UEs 102 and 104 broadcast a PRS on V2V link 103, the distance or relative position between UEs 102 and 104 can be directly determined. When UEs 102 and 104 broadcast a PRS on V2I links 107 and 109 or via links 113 and 115, the distance or relative position between UE 102 and UE 110 or UE 112, and between UE 104 and UE 110 or UE 112, can be directly determined.

[0042] Direct wireless communication between UEs 102 and 104 and UEs 110 and 112 requires no network infrastructure and enables low latency communication, which is beneficial for accurate ranging or positioning. Therefore, such direct wireless communication may be desirable for ranging over short distances, such as with nearby vehicles or infrastructure.

[0043] Figure 1 The UE shown (e.g., any one of V-UE 102, V-UE 104, RSU 110, and UE 112) can be configured to perform ranging and / or positioning operations, such as RTT-based ranging.

[0044] As an example, Figure 2 Signaling diagram 200 illustrates the timing and frequency of various messages used in a ranging or positioning session that can be sent and received by the initiating UE (UEX) and three responding UEs (UEA, UEB, and UEC). For example, Figure 2 The description covers capability message 201 and RTT-based ranging session 202, during which several messages are transmitted between the initiating UE and the responding UE, including a pre-PRS message 204 requesting and accepting the ranging session, a PRS signal 208 for measurement, and a post-PRS message 208 for exchanging measurement payloads. Each set containing pre-PRS 204, PRS 206, and post-PRS 208 can be considered a single unit or PRS cycle. Each PRS cycle includes pre-PRS message 204, PRS signal 206, and post-PRS message 208, and is therefore referred to herein as ranging session 202. The ranging session (PRS cycle) can be periodic with a period T_r, and the capability message can be periodic with a period T_c, where T_r > T_c. Figure 2 In this context, signaling from the initiating UEX is marked as "X", signaling from the first responding UEA is marked as "A", signaling from the second responding UEA is marked as "B", and signaling from the third responding UEA is marked as "C". The signaling from the initiating UEX is the first box in each of the PRS pre-message 204, PRS signal 206, and PRS post-message 208, followed by the responding UEs (UEA, UEB, and UEAC).

[0045] As explained, this includes a UE broadcast capability message 201 for both the initiating UE and the responding UE. The capability message is not part of the ranging session, but may include information that the initiating UE can use to initiate a ranging session with a selected UE. For example, the capability message may include the UE ID, the UE's ranging capabilities, the channels the UE is configured to use, etc. The capability message may additionally indicate whether the UE needs to determine its location, or whether its location is known, and whether it can be used as an anchor UE to locate other UEs. It should be understood that, although... Figure 2 It is explained that capability message 201 has the same order as the messages in ranging session 202, but the order can actually be different.

[0046] The PRS pre-message 204 (e.g., a ranging pre-message message) is used by the UE to request and acknowledge a ranging session. As explained, the PRS pre-message 204 may be transmitted on licensed spectrum to ensure reliability. The PRS pre-message 204 may be broadcast or unicast, for example, via a Radio Resource Control (RRC) connection. The initiating UE broadcasts the initial PRS pre-message 204 (a gray box marked with an X) to indicate a ranging session between the initiating UE and the responding UE, and this message provides information for the ranging session. For example, the PRS pre-message 204 from the initiating UE may include the IDs of the participating UEs, namely the initiating ID and the responding ID. The PRS pre-message may include the PRS ID to be used by the initiating UE, and in some implementations, the PRS ID to be used by the responding UE. If the PRS ID will be fixed on multiple PRS exchanges (e.g., for multiple units in ranging session 202), the initiating UE may include an ID associated with the current PRS exchange, such as a session ID. The initiating UE can determine when the PRS signal 206 will be transmitted, for example, this can be configured from a higher layer within the initiating UE. The initiating UE can indicate the timing of the PRS by sending a timeslot number close to the desired PRS transmission time. In some implementations, the timeslot can be subject to local clock errors. In some implementations, the initiating UE can further provide the timing of the PRS to be transmitted by the responding UE. The initiating UE can further indicate the frequency that will be used by the initiating UE to broadcast the PRS signal 206. For example, the PRS frequency can be selected from the available set of total bandwidth, or the PRS frequency can be selected by sensing interference and selecting one or more channels whose average interference reference received power (RSRP) is less than a threshold. The initiating UE can indicate the number of PRS cycles it will perform during ranging session 202. The number of PRS cycles can be configured from a higher layer. For example, a pre-PRS message for each PRS cycle can indicate the current PRS cycle relative to the total requested PRS cycles, where the number of current cycles increments after each cycle completes.

[0047] The initial PRS pre-message from the initiating UE is received and decoded by the responding UE identified in the initial PRS pre-message. The responding UE may send a response PRS pre-message 204 (marked by gray boxes A, B, and C) to acknowledge receipt of the initial PRS pre-message, which may additionally provide information for the ranging session. For example, each responding UE may determine the timing of its PRS signal 206 (e.g., based on the initiating UE's PRS timing plus a delay, which may be based on hardware constraints and interference levels, as well as the number and order of the responding UEs). For example, the delay may be relatively low when the PRS processing time is short and environmental interference is low, and relatively high when the PRS processing time is long and environmental interference is high. The responding UE may indicate the determined time of its PRS by sending a timeslot number close to the determined PRS transmission time. In some implementations, the timeslot may be subject to local clock errors. Each responding UE may indicate the PRS ID it will use, or may indicate that it will use the PRS ID indicated in the initial PRS pre-message. If the PRS ID will be fixed across multiple PRS exchanges (e.g., multiple PRS cycles in ranging session 202), the responding UE may include an ID associated with the current PRS exchange, such as a session ID, which is received in the initial PRS pre-message from the initiating UE. Each responding UE may further indicate the frequency that will be used to broadcast its PRS signal 206. The responding UE may broadcast a PRS pre-message 204, which can be received by the initiating UE (and other responding UEs). In some implementations, each responding UE may transmit the PRS pre-message 204 to the initiating UE via unicast over an RRC connection.

[0048] PRS signal 206 is exchanged by the participating UEs. The initiating and responding UEs are aware of the expected timing of the PRS signal and the PRS ID (and any session IDs used with this exchange) and the frequency used to broadcast PRS signal 206. PRS signal 206 can be broadcast on unlicensed spectrum subject to LBT constraints. In some implementations, when using unlicensed spectrum, the initiating UE X may reserve transmissions for responding UEs (UEA, UEB, and UEC) so that these responding UEs do not need to perform LBT. For example, the initiating UE X broadcasts its PRS signal 206 at a predetermined time indicated in the pre-PRS message 204 (white box marked X). In some implementations, when the PRS signal is deployed in unlicensed spectrum, the initiating UE broadcasts its PRS signal at a predetermined time plus a random waiting time due to LBT constraints. In some implementations, the LBT may be a Category 2 LBT with a fixed-window open channel assessment (CCA) or a Category 4 LBT with a variable-window CCA. The initiating UE uses the PRS signal corresponding to the PRS ID and the frequency resources indicated in its initial PRS pre-message 204. The initiating UE stores a time instance of when the PRS signal was broadcast, and the responding UE stores a time instance of when the PRS signal was received. In some implementations, the time instance may be subject to local clock errors.

[0049] Similar to the initiating UE, each responding UE broadcasts its PRS signal 206 (marked in white boxes A, B, and C) at a determined time indicated in its PRS pre-message 204 (or a determined time allocated by the initiating UE). In some implementations, when the PRS signal is deployed in unlicensed spectrum, each responding UE may broadcast its PRS signal at the determined time plus a random waiting time due to LBT constraints. In some implementations, the LBT may be a Class 2 LBT with a fixed window CCA or a Class 4 LBT with a variable window CCA. Each responding UE uses the PRS signal corresponding to the PRS ID and uses the frequency resources indicated in its PRS pre-message 204. Each responding UE maintains a time instance at which its PRS signal is broadcast, and the initiating UE (and optionally other responding UEs) maintains a time instance at which the PRS signal is received. In some implementations, the time instance may be subject to local clock errors.

[0050] Therefore, each UE records the time of departure (ToD) of its broadcast PRS signal and measures the time of arrival (ToA) of PRS signals received from other UEs. The PRS signal can be any signal suitable for ranging, such as those defined for DSRC or C-V2X. For example, the PRS signal can be a pseudo-noise (PN) sequence modulated by quadrature phase shift keying (QPSK). The ToA and ToD resolutions of the PRS signal increase with increasing frequency bandwidth. In some implementations, the angle of departure (AoD) and angle of arrival (AoA) of both the broadcast and received PRS signals can also be measured. Broadcasting on unlicensed spectrum is advantageous because a wider bandwidth is available. For example, in some implementations, the PRS can be broadcast on one or more UNII radio bands, including, for example, one or more of the UNII-1, UNII-2A, UNII-2B, or UNII-3 radio bands.

[0051] Post-PRS message 208 is sent by each UE to exchange measurement payloads. As explained, post-PRS message 208 can be transmitted on licensed spectrum to ensure reliability. In some implementations, post-PRS message 208 can be broadcast or unicast via an RRC connection. The initiating UE X sends its post-PRS message 208 (shaded box marked X) and indicates when it broadcasts the PRS signal 206 (ToD) and when it receives the PRS signal from the responding UE (ToA). In some implementations, ToA can be calculated as a relative time to the ToD of its broadcast PRS signal, and this relative time can be provided. In some implementations, the relative time can be approximated to the closest multiple of the time scale shared by the initiating UE and the responding UE. In some implementations, the initiating UE can provide an indication of its location (if known) in the post-PRS message 208. For example, the location of the initiating UE can be its location at a specific time, such as the broadcast time of its PRS signal or the arrival time of the PRS signal from the responding UE. The PRS post-message 208 may further include the orientation of the initiating UE, the broadcast indicator of the PRS signal 206, the reception indicator of the PRS from the responding UE, and other relevant measurements, such as map information and information about the location of reflectors of the UE.

[0052] Similar to the initiating UE, each responding UE transmits its post-PRS signal 208 (shaded boxes labeled A, B, and C) to provide a measurement payload. Each responding UE may indicate whether it received a PRS signal from the initiating UE and may indicate when it broadcast a PRS signal 206 (ToD) and when it received a PRS signal from the initiating UE (and optionally from other responding UEs) (ToA). In some implementations, ToD may be calculated as a relative time with respect to ToA of the PRS signal from the initiating UE (and optionally with respect to ToA of the PRS from other responding UEs). In some implementations, the relative time may approximate the closest multiple of the timescale shared by the initiating UE and the responding UEs. In some implementations, the responding UE may provide an indication of its location (if known) in the post-PRS message 208. For example, the location of the responding UE provided may be a location at a specific time, such as the arrival time of the PRS signal from the initiating UE or the departure time of its broadcast PRS signal. The PRS post-message 208 may further include the orientation of the initiating UE, the broadcast indicator of the PRS signal 206, the reception indicator of the PRS from the responding UE, and other relevant measurements, such as map information and information about the location of reflectors of the UE.

[0053] After receiving the PRS message, the initiating UE can calculate its distance (and in some implementations its location) (e.g., using a Kalman filter), and then transmit the next cycle of the PRS message at a time indicated by the upper layer or at a time determined autonomously by the initiating UE.

[0054] The time between the first PRS pre-message 204 and the last PRS post-message 208 can be the duration of the ranging session, and can be, for example, 100 milliseconds. In some implementations, multiple PRS cycles (e.g., multiple instances of PRS pre-message 204, PRS 206, and PRS post-message 208) can be used together to provide higher accuracy.

[0055] Both the initiating UE and the responding UE can determine the distance between themselves and every other UE in a ranging session based on the ToD and ToA of the broadcast PRS signal. For example, the RTT between any pair of UEs (which can be any pair of initiating and responding UEs) can be based on the PRS. i ToD of the signal i and ToA i (Where, for PRS broadcast from the first UE, i=1, and for PRS broadcast by the second UE, i=2) is determined as the difference between ToD1 and ToA2 minus the difference between ToA1 and ToD2, for example, as follows:

[0056] RTT = (ToD1 – ToA2) – (ToA1 – ToD2) Equation 1

[0057] The RTT value is the round-trip time of a signal, and therefore, the distance (spacing) between UE1 and UE2 can be determined as RTT / 2c, where c is the speed of light.

[0058] If the locations of one or more responding UEs are known, the location of another UE can be determined using the distance between the initiating UE and the responding UEs, as well as the known location of one of these responding UEs; therefore, a ranging session can be a positioning session. A responding UE with a known location that can be used for positioning is sometimes referred to herein as an anchor UE. The location of the anchor UE can be provided to other UEs via message transmission (e.g., in a pre-PRS or post-PRS message). If the distances to multiple anchor UEs are determined, the locations of these multiple anchor UEs can be used for multilateral positioning to determine the location of the initiating UE (or other responding UEs).

[0059] Angular measurements (e.g., AoD and AoA) can be used, for example, to assist in positioning. As an example, the relative positions of two UEs can be determined based on the distance between them and the measured AoA. With the relative positions of the UEs determined, the actual position of the other UE can be determined if the actual position of one of the UEs is known (this can be provided, for example, in PRS pre-message 204 or PRS post-message 208). If a third UE knows the positions of the two UEs, the distance between the third UE and each of the other two UEs will produce two possible positions for the third UE, which can be resolved based on the AoD / AoA information. For example, AoD can be useful if the AoA resolution is poor or incorrect. AoD can be measured, for example, based on the known orientation of the UE (e.g., determined by a magnetometer) and the direction of the transmitted signal relative to the UE (e.g., relative to the antenna array of the UE used for beamforming). AoA can be measured based on the phase difference between the received signal at different antenna elements of the antenna array and (e.g., determined by a magnetometer) the known orientation of the UE. Additionally, geographic constraints can be used to assist in location, for example, by constraining the possible location of a vehicle based on its reach (such as roads).

[0060] As discussed above, due to the distributed mechanism used for ranging, multiple UEs may initiate independent ranging sessions that include at least some of the same responding UEs at approximately the same time. For example, two initiating UEs may separately broadcast their own PRS pre-signals to the same set of responding UEs, resulting in two independent ranging sessions that include the same responding UEs and occur at the same time. To illustrate, two vehicles may be approaching or stopped at an intersection, and the V-UE associated with each vehicle may initiate an uncoordinated ranging session with several anchor UEs (e.g., RSUs and / or V-UEs or pedestrian-held UEs) located near the intersection with known precise locations. Similarly, a pedestrian-held UE may initiate an uncoordinated ranging session with anchor UEs near the intersection. It is desirable to combine the uncoordinated ranging sessions of multiple UEs into a single combined ranging session. Combining ranging sessions can significantly improve the ranging / positioning accuracy of each UE, for example, by reducing the number of overhead messages (e.g., pre-ranging and post-ranging messages) on licensed spectrum and by increasing the opportunity for PRS transmission on unlicensed spectrum.

[0061] As an example, Figure 3 Illustration 300 illustrates two independent ranging session sets 302 and 312 that can be initiated by initiating UEs (UEX and UEY), respectively, and each ranging session 302 and 312 includes the same responding UEs (UEA, UEB, and UEC), which can be anchored UEs, such as stationary RSU UEs, or mobile UEs, such as V-UEs or pedestrian UEs with known accurate locations (e.g., from satellite positioning systems (SPS)). Similar to Figure 2 Each ranging session 302 and 312 (i.e., PRS cycle) includes a pre-ranging message (PRS messages 304 and 314 shown in gray boxes), a ranging signal (PRS signals 306 and 316 shown in white boxes), and a post-ranging message (PRS messages 308 and 318 shown in shaded boxes). Signaling from the initiating UE (UEX and UEY) is the first box in each of the PRS messages 304 and 314, PRS signals 306 and 316, and PRS messages 308 and 318, followed by the responding UE (UEA, UEB, and UEC). Similarly, similar to... Figure 2 Signaling from the initiator UEX is marked as “X”, signaling from the initiator UEY is marked as “Y”, signaling from the first responder UEA is marked as “A”, signaling from the second responder UEB is marked as “B”, and signaling from the third responder UEC is marked as “C”.

[0062] During ranging sessions 302 and 312, the responding UE (e.g., UEB) may monitor the ranging session. For example, the responding UEB may be an anchor UE (such as an RSU or V-UE or a pedestrian-held UE) with a known accurate location (e.g., from an SPS system), wherein the responding UEB provides this known accurate location to the initiating UEX (e.g., in PRS post-message 308) and to the initiating UEY (e.g., in PRS post-message 318). The initiating UEs (UEX and UEY) may perform ranging with the responding UEs and localization using the location of the anchor UE (such as UEB).

[0063] The responding UEB can decode the periodic broadcast of pre-ranging messages (PRS pre-message message 304) from each individual and each initiating UE (e.g., initiating UEX and initiating UEY) in each ranging session over a time period (e.g., T1 seconds). From the PRS pre-message message 304, the responding UEB determines the UE-specific identifiers of the initiating UEs (UEX and UEY) and the responding UEs (UEB, UEB, and UEC) included in their respective ranging sessions. Figure 3 In the example described, ranging sessions 302 and 312 share the exact same responder UE. However, in practice, one or both of ranging sessions 302 and 312 may include a responder UE that is not included in another ranging session. Therefore, the responder UEB identifies the UE participating in each ranging session, for example, based on information provided in the PRS pre-message.

[0064] Additionally, in some implementations, the responding UEB can determine the speed of the initiating UEs (UEX and UEY). For example, in one implementation, the initiating UEs may provide their speed in a pre-PRS message 304 or a post-PRS message 308. In another implementation, the responding UEB can determine the change in the initiating UE's position over a time period to determine the speed. The initiating UEs may provide their position in a post-PRS message 308, or the responding UEB may determine their position from ranging. In yet another implementation, the responding UE can determine the change in distance to the initiating UE over a time period, which can provide an indication of the speed of the initiating UE's travel. For example, the responding UEB may determine the average speed of the initiating UE, or another statistical measurement of the speed.

[0065] The time period T1 for the responding UEB to monitor ranging sessions 302 and 312 can be based on the speed of the initiating UE. For example, if the speed of the initiating UEs (UEX and UEY) is relatively slow (such as when these initiating UEs are stopped at an intersection or in traffic congestion), the responding UEB can monitor ranging sessions 302 and 312 for an extended period, meaning the time period T1 may be relatively long. Conversely, if the speed of these initiating UEs (UEX and UEY) is relatively fast (such as when these initiating UEs are traveling across an intersection or in smooth traffic), the responding UEB can monitor ranging sessions 302 and 312 for a shorter period, meaning the time period T1 may be relatively short. For example, in one implementation, if the average speed of the initiating UE is greater than a threshold speed, the time period T1 may be reduced from the default time period. Conversely, if the average speed of the initiating UE is less than a threshold speed, the time period T1 may be increased from the default time period. In some examples, the amount reduced or increased from the default time period may be based on the difference between the average speed and a predetermined threshold speed, or multiple threshold speeds may be used. In one implementation, additional or other factors may be used to determine the duration of the time period T1. As an example, when determining the duration of time period T1, environmental parameters can be considered, such as whether the traffic lights in the area of ​​the initiating UE are red or green. For instance, if the initiating UEs stop at the intersection because of a red light, the monitoring period T1 can be increased, or if the initiating UEs cross the intersection when the light is green, the monitoring period T1 can be decreased.

[0066] A UEB can become the initiating UE and can initiate a combined ranging session 322, which includes all UEs participating in ranging sessions 302 and 312. Each combined ranging session 322 (i.e., PRS cycle) includes a pre-ranging message (PRS pre-ranging message 324 shown in gray), a ranging signal (PRS signal 326 shown in white), and a post-ranging message (PRS post-ranging message 328 shown in shaded). Therefore, signaling from the new initiating UEB appears as the first box in each of the PRS pre-ranging message 324, PRS signal 326, and PRS post-ranging message 328, followed by the responding UEs (UEX, UEY, UEA, and UEC).

[0067] The original initiating UEs (UEX and UEY) from ranging sessions 302 and 312 receive and decode the broadcast of the pre-PRS message 324 from the new initiating UEB. For example, when the original initiating UEs (UEX and UEY) are identified together with UEs that are responding UEs in the original ranging sessions 302 and 312 as responding UEs in the combined ranging session 322, these original initiating UEs (UEX and UEY) may terminate the initiation of ranging sessions 302 and 312. In another implementation, the new initiating UEB may include an indication in the pre-PRS message 324 that the original initiating UEs wish to terminate the initiation of their independent ranging sessions, or may send this indication to these initiating UEs in a separate V2X message.

[0068] The original initiating UEs (UEX and UEY) act as responding UEs during the combined ranging session 322 and continue performing their ranging (and positioning) determinations. A new initiating UEB may continue initiating the combined ranging session 322 for a period of time, e.g., T2 seconds. After time period T2, the new initiating UEB terminates the initiation of the combined ranging session 322, and the original initiating UEs (UEX and UEY) may restart their independent ranging sessions, which may include the same or different sets of responding UEs. In some implementations, the initiating UEs (UEX and UEY) may start their independent ranging sessions when the new initiating UEB terminates the broadcast of the pre-PRS message for the combined ranging session 322. Alternatively, the new initiating UEB may provide the initiating UEs with an indication of time period T2 or the remaining time within time period T2 (e.g., in the pre-PRS message or a separate V2X message), and the original initiating UEs (UEX and UEY) may use the expiration of time period T2 as a trigger to restart their independent ranging sessions.

[0069] The time period T2 of the combined ranging session 322 can be based on the speed of the initiating UE, similar to the time period T1 discussed above. For example, if the speed of the initiating UEs (UEX and UEY) is relatively slow (e.g., these initiating UEs are stopped at an intersection or there is traffic congestion), the new initiating UEB can initiate the combined ranging session 332 for an extended period, meaning the time period T2 may be relatively long. Conversely, if the speed of these initiating UEs (UEX and UEY) is relatively fast (e.g., these initiating UEs are moving across an intersection or there is no traffic), the responding UEB can initiate the combined ranging session 332 for a shorter period, meaning the time period T2 may be relatively short. For example, in one implementation, if the average speed of the initiating UE is greater than a threshold speed, the time period T2 can be reduced from the default time period. Conversely, if the average speed of the initiating UE is less than a threshold speed, the time period T2 can be increased from the default time period. In some examples, the amount reduced or increased from the default time period can be based on the difference between the average speed and a predetermined threshold speed, or multiple threshold speeds can be used. In one implementation, additional or other factors can be used to determine the duration of the time period T2. As an example, when determining the duration of time period T2, environmental parameters can be considered, such as whether the traffic lights in the area of ​​the initiating UE are red or green. For instance, if these initiating UEs stop at the intersection because of a red light, the combined ranging session period T2 can be increased, or if these initiating UEs cross the intersection when the light is green, the combined ranging session period T2 can be decreased.

[0070] By monitoring multiple ranging sessions and combining them into a single combined ranging session, the total number of pre-PRS messages, PRS signals, and post-PRS messages can be significantly reduced. Furthermore, the number of PRS transmissions on unlicensed spectrum can be reduced, increasing the chances of a successful PRS transmission for each UE.

[0071] Figure 4 The diagram illustrates certain exemplary features of a user equipment (UE) 400, which may be as follows: Figure 1 The UE, RSU 110 in vehicle 102 or 104 as described herein, or UE112 held by pedestrian 114, or Figure 3This refers to any UE described herein. UE 400 can be configured to act as an initiating UE or a responding UE during ranging sessions, which are combined into a single combined ranging session to reduce signaling overhead and improve efficiency, as discussed herein. If UE 400 is a V-UE, it can be configured to control the autonomous driving of a vehicle (e.g., vehicle 102). For example, UE 400 may include a vehicle interface 405 through which commands for autonomous driving are provided to the vehicle, and sensor inputs, including speed and acceleration, can be provided from the vehicle to UE 400. For example, UE 400 may include one or more processors 402, memory 404, an inertial measurement unit (IMU) 407 (which may include, for example, an accelerometer, gyroscope, magnetometer, etc., for detecting orientation relative to a global or local reference frame and motion of a vehicle or one or more motion characteristics), a satellite positioning system (SPS) receiver 409 for determining, for example, GPS location, and external interfaces, including, for example, a wireless wide area network (WWAN) transceiver 410 and a wireless local area network (WLAN) transceiver 414, which may be operatively coupled to a non-transient computer-readable medium 420 and memory 404 via one or more connections 406 (e.g., bus, line, fiber optic, link, etc.). UE 400 may further include additional items not shown, such as a user interface by which a user can interface with a user equipment, which may include, for example, a display, keypad, or other input devices (such as a virtual keypad on a display). In some example implementations, all or part of UE 400 may take the form of a chipset, etc.

[0072] Transceiver 410 can be, for example, a cellular transceiver, which can be configured to transmit and receive direct communication in a wireless network, such as... Figure 1 As explained, transceiver 410 may include a transmitter 411 implemented to transmit one or more signals over one or more types of wireless communication networks, and a receiver 412 to receive one or more signals transmitted over such wireless communication networks. Transceiver 414 may be, for example, a short-range transceiver and may be configured to transmit and receive direct communication in a wireless network, such as... Figure 1As explained, transceiver 414 may include transmitter 415 and receiver 416. Transmitter 415 is implemented to transmit one or more signals (including ranging signals (PRS signals) and pre-ranging (PRS) and post-ranging (PRS) messages) over one or more types of wireless communication networks and to combine and split the messages. Receiver 416 is used to receive one or more signals (e.g., including PRS and PRS and PRS) transmitted over the same or similar wireless communication network and to combine and split the messages. Transceivers 410 and 414 enable UE 400 to communicate with transport entities using D2D communication links such as DSRC, C-V2X, or 5G NR.

[0073] In some embodiments, the UE 400 may include an antenna 409, which may be internal or external. The antenna 409 may be used to transmit and / or receive signals processed by transceiver 410 and / or transceiver 414. In some embodiments, the antenna 409 may be coupled to transceiver 410 and / or transceiver 414. In some embodiments, measurements of signals received (transmitted) by the UE 400 may be performed at the connection point between the antenna 409 and transceiver 410 and / or transceiver 414. For example, a measurement reference point for measuring the received (transmitted) RF signal may be an input (output) terminal of receivers 412, 416 (transmitters 411, 415) and an output (input) terminal of antenna 409. In a UE 400 having multiple antennas 409 or an antenna array, the antenna connector may be considered as a virtual point representing the aggregated output (input) of multiple antennas. The phase difference of the received signals at multiple antennas or antenna arrays can be used to determine the AoA of the signal relative to the antenna array, which can be converted to a local or global reference frame based on the known orientation of the UE 400 (e.g., based on the orientation of the UE 400 relative to a global or local reference frame as measured by the IMU 407).

[0074] The one or more processors 402 may be implemented using a combination of hardware, firmware, and software. For example, the one or more processors 402 may be configured to perform the functions discussed herein by implementing one or more instructions or program code 408 on a non-transient computer-readable medium, such as medium 420 and / or memory 404. In some embodiments, the one or more processors 402 may represent one or more circuits that may be configured to perform at least a portion of a data signal calculation procedure or process associated with the operation of UE 400.

[0075] Medium 420 and / or memory 404 may store instruction or program code 408 containing executable code or software instructions that, when executed by one or more processors 402, cause those processors 402 to operate as a dedicated computer programmed to perform the techniques disclosed herein. As explained in UE 400, medium 420 and / or memory 404 may include one or more components or modules that may be implemented by the one or more processors 402 to perform the methodologies described herein. Although each component or module is explained as software in medium 420 executable by the one or more processors 402, it should be understood that each component or module may be stored in memory 404 or may be dedicated hardware in or outside of the one or more processors 402.

[0076] Several software modules and data tables may reside in medium 420 and / or memory 404 and be utilized by one or more processors 402 to manage both the communication and functionality described herein. It should be understood that the organization of the contents of medium 420 and / or memory 404 as shown in UE 400 is merely exemplary, and thus, the functionality of the individual modules and / or data structures may be combined, separated, and / or constructed in different ways depending on the implementation of UE 400.

[0077] Medium 420 and / or memory 404 may include a ranging module 421, which, when implemented by one or more processors 402, configures one or more processors 402 to participate in a ranging session as an initiating UE or a responding UE, as discussed herein. For example, ranging module 421 may include a pre-ranging module (PRS pre-message module 422), a ranging signal module (PRS module 424), a post-ranging module (PRS post-message module 426), and a ranging module 428.

[0078] Medium 420 and / or memory 404 may include a PRS pre-message module 422, which, when implemented by one or more processors 402, is configured to generate and transmit or receive ranging pre-message messages via transceiver 414, such as PRS pre-message messages for initiating or accepting a ranging session. PRS pre-message messages may be broadcast, multicast, or unicast (via an RRC connection). In some implementations, PRS messages may be transmitted and received on licensed spectrum. A PRS pre-message may be an initiating PRS pre-message message for initiating a ranging session or a responding PRS pre-message message for confirming receipt of an initiating PRS pre-message message. PRS pre-message messages may include identifiers for locating the initiating UE and one or more responding UEs of the session, which may be monitored by UE 400 over multiple ranging sessions. For example, participating UEs may be determined from capability messages received by UE 400 or from monitoring PRS pre-messages broadcast by multiple initiating UEs over a time period. In some implementations, for example, if a combined ranging session is being initiated, the pre-PRS message received by UE 400 may include an indication that UE 400 intends to terminate the ranging session and that UE 400 is a responder in a new ranging session (e.g., a combined ranging session). In some implementations, this indication may be provided in a separate message (e.g., a V2X message). Additionally, in some implementations, the time period (T2) indicating the duration of the combined ranging session may be included in the pre-PRS message, and upon the expiration of this time period, the combined ranging session will terminate and a separate ranging session may be initiated. The pre-PRS message may further include ranging signal attributes to be used in the ranging session. For example, the pre-PRS message may include an identifier for the ranging signal and timing information (e.g., a timeslot number) for the ranging signal, as well as the frequency to be used to broadcast the ranging signal. For example, the frequency may be selected from the available set of bandwidths and may be selected by sensing interference and selecting a channel with an average interference RSRP less than a threshold. In some implementations, the initiator's pre-PRS message may include an indication of the number of PRS cycles requested and the current PRS cycle.

[0079] Medium 420 and / or memory 404 may include a PRS module 424, which, when implemented by one or more processors 402, configures one or more processors 402 to broadcast ranging signals to and receive ranging signals from other UEs in a ranging session, as discussed herein. For example, the ranging signal may be a PRS signal, such as a sequence of pseudo-noise (PN) modulated by quadrature phase shift keying (QPSK) as discussed herein. The ranging signal may be broadcast at a determined time and via an identifier and a frequency indicated on a pre-PRS message. The ranging signal may be broadcast and received on unlicensed spectrum and may be broadcast according to Category 2 or Category 4 LBT constraints. One or more processors 402 may, for example, be configured to measure the ToD of the broadcast ranging signal and the ToA of the received ranging signal, and may be configured to measure the AoD of the broadcast ranging signal and the AoA of the received ranging signal.

[0080] Medium 420 and / or memory 404 may include a PRS post-message module 426, which, when implemented by one or more processors 402, configures one or more processors 402 to send and receive post-range messages to other UEs in a ranging session via transceiver 414, as discussed herein. The PRS post-message may include, for example, an indication of ToD for a broadcast ranging signal and, in some implementations, an indication of AoD, and an indication of ToA for a received ranging signal and, in some implementations, an indication of AoA. In some implementations, the indications of ToD and ToA may be the difference between ToD and ToA. In some implementations, the PRS post-message may include an indication of the UE's location, for example, if the UE is an anchor UE used to locate another UE.

[0081] The medium 420 and / or memory 404 may include a ranging module 428, which, when implemented by one or more processors 402, is configured to determine the distance to other UEs based on broadcast ranging signals as measured by UE 400 and received in PRS post-messages from other UEs, and the ToD and ToA of the received ranging signals.

[0082] The medium 420 and / or memory 404 may include a positioning module 430, which, when implemented by one or more processors 402, is configured to determine the location of the broadcast UE 400 based on one or more distances to the broadcast UE and their location information, for example, using multilateral positioning or other appropriate techniques discussed herein. For example, the one or more processors 402 may implement a Kalman filter or an extended Kalman filter to determine the location of the UE 400.

[0083] Medium 420 and / or memory 404 may include a speed determination module 432, which, when implemented by one or more processors 402, is configured to: determine the speed of another UE (e.g., a UE initiating a ranging session). The speed of the other UE may be determined, for example, in one implementation, the one or more processors 402 may be configured to receive an indication of the UE's speed, for example, in a pre-PRS or post-PRS message received via transceiver 414. The one or more processors 402 may be configured to determine the speed of the other UE based on changes in the UE's location over a time period (where the location of another UE may be received via transceiver 414 in a post-PRS message). The one or more processors 402 may be configured to determine the speed of the other UE based on changes in distance to the other UE over a time period. The one or more processors 402 may be configured to determine the average speed or other statistically relevant speed combinations of the initiating UE.

[0084] The medium 420 and / or memory 404 may include a T1 / T2 determination module 434, which, when implemented by one or more processors 402, configures the one or more processors 402 to determine a time period (T1 period) for monitoring several independent ranging sessions and a time period (T2 period) for performing a combined ranging session. For example, the time periods T1 and T2 may be based on the speed of the initiating UE. For example, if the average speed of the initiating UE is greater than a predetermined threshold, the time periods T1 and T2 may be decreased, and conversely, if the average speed of these initiating UEs is less than the predetermined threshold, the time periods T1 and T2 may be increased. The amount of increase and / or decrease may differ for the time periods T1 and T2 and may vary based on the difference between the average speed and the threshold, or multiple thresholds may be used.

[0085] The medium 420 and / or memory 404 may include a combined ranging module 436, which, when implemented by one or more processors 402, configures the one or more processors 402 to participate in a combined ranging session, for example, by initiating a combined ranging session after monitoring multiple independent ranging sessions and identifying the participating UEs in each ranging session. For example, by initiating a combined ranging session together with all UEs participating in independent ranging sessions via a PRS pre-message. The one or more processors 402 may be further configured to initiate a combined ranging session for a time period T2 and terminate the initiation of the combined ranging session after the time period T2 expires.

[0086] The methodologies described herein can be implemented through various means depending on the application. For example, these methodologies can be implemented in hardware, firmware, software, or any combination thereof. For hardware implementation, the one or more processors 402 can be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0087] For firmware and / or software implementations, these methodologies can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described herein. Any machine-readable medium that tangibly embodies instructions can be used to implement the methodologies described herein. For example, software code can be stored in a non-transient computer-readable medium 420 or memory 404 connected to and executed by one or more processors 402. Memory can be implemented within or outside of the one or more processors. As used herein, the term "memory" means any type of long-term, short-term, volatile, non-volatile, or other memory, and is not limited to any particular type or number of memories, or the type of medium on which memory is stored.

[0088] If implemented in firmware and / or software, the functionality may be stored as one or more instructions or program code 408 on a non-transient computer-readable medium (such as medium 420 and / or memory 404). Examples include computer-readable media encoding data structures and computer-readable media encoding computer programs 408. For example, a non-transient computer-readable medium including program code 408 stored thereon may include program code 408 that supports monitoring multiple ranging sessions and combining these ranging sessions into a single combined ranging session in a manner consistent with the disclosed embodiments. Non-transient computer-readable medium 420 includes physical computer storage media. The storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such non-transient computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage, or other magnetic storage devices, or any other medium that can be used to store desired program code 408 in the form of instructions or data structures and that can be accessed by a computer; as used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs, wherein disks often magnetically reproduce data, while discs optically reproduce data using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0089] In addition to being stored on computer-readable medium 420, instructions and / or data may also be provided as signals included on a transmission medium in a communication apparatus. For example, a communication apparatus may include a transceiver 410 having signals indicating instructions and data. These instructions and data are configured to cause one or more processors to perform the functions described herein. That is, the communication apparatus includes a transmission medium having signals indicating information for performing the disclosed functions.

[0090] Memory 404 can represent any data storage device. Memory 404 may include, for example, main memory and / or secondary memory. Main memory may include, for example, random access memory, read-only memory, etc. Although described in this example as separate from one or more processors 402, it should be understood that all or part of the main memory may be located within one or more processors 402 or otherwise co-located / coupled with one or more processors 402. Secondary memory may include, for example, memory of the same or similar type as the main memory and / or one or more data storage devices or systems (such as, for example, disk drives, optical disc drives, tape drives, solid-state drives, etc.).

[0091] In some implementations, secondary memory may be operatively accommodated or otherwise configured to be coupled to non-transient computer-readable medium 420. Thus, in some example implementations, the methods and / or apparatus presented herein may take the form of a computer-readable medium 420 which may include all or a portion of computer-readable code 408 stored thereon, which, when executed by one or more processors 402, may be operatively implemented to perform all or a portion of the example operations as described herein. Computer-readable medium 420 may be part of memory 404.

[0092] Figure 5 This is a flowchart 500 illustrating a method for performing ranging by a first UE in a distributed user equipment (UE) system. For example, the first UE may be similar to... Figure 3 UEB or Figure 4 UE 400 in the middle.

[0093] In block 502, the first UE monitors a first ranging session set initiated by a first initiating UE. The first ranging session set includes a first plurality of pre-ranging messages broadcast by the first initiating UE that identify UEs in the first ranging session set, such as references. Figure 3The ranging session 302 discussed in the text. An apparatus for monitoring a first set of ranging sessions initiated by a first initiating UE, the first set of ranging sessions including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first set of ranging sessions, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a pre-ranging message module 422.

[0094] In box 504, the first UE monitors a second ranging session set initiated by the second initiating UE. The second ranging session set includes a second plurality of pre-ranging messages broadcast by the second initiating UE that identify UEs in the second ranging session set, such as references. Figure 3 The ranging session 312 discussed in the text. An apparatus for monitoring a second set of ranging sessions initiated by a second initiating UE, the second set of ranging sessions including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second set of ranging sessions, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a pre-ranging message module 422.

[0095] In box 506, the first UE initiates a third ranging session set by broadcasting a third pre-ranging message identifying UEs in the third ranging session set. The third ranging session set includes UEs in the first ranging session set and UEs in the second ranging session set, such as reference... Figure 3 The combined ranging session 322 discussed herein. For example, the first and second ranging session sets terminate in response to the initiation of a third ranging session set, for example, as referred to Figure 3 The combined ranging session 322 discussed in the section. An apparatus for initiating a third ranging session set by broadcasting a third plurality of pre-ranging messages identifying UEs in a third ranging session set, the third ranging session set including UEs in a first ranging session set and UEs in a second ranging session set, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a combined ranging module 436, a ranging module 421 and a pre-ranging message module 422.

[0096] For example, the first UE may be an anchor UE with a known location, which the first UE provides to the first initiating UE and the second initiating UE for positioning, as discussed, for example, with reference to PRS messages 308 and 318 in ranging sessions 302 and 312.

[0097] In one implementation, the first UE can determine the speeds of the first initiating UE and the second initiating UE while monitoring the first ranging session and the second ranging session, for example, as shown in reference Figure 3 The ranging sessions 302 and 312 discussed herein. An apparatus for determining the speeds of a first initiating UE and a second initiating UE while monitoring a first ranging session and a second ranging session, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a speed determination module 432. The first and second ranging session sets may be monitored for a first time period, and a third ranging session set may be executed for a second time period, wherein the first and second time periods are based on the speeds of the first initiating UE and the second initiating UE, for example, as referred to Figure 3 The ranging sessions 302 and 312 in the table discuss this. For example, when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, the first UE may reduce the first time period, and when the average speed of the first initiating UE and the second initiating UE is less than the threshold, the first UE may increase the first time period, for example, as referred to Figure 3 The ranging sessions 302 and 312 in the table discuss this. When the average speed of the first initiating UE and the second initiating UE is greater than a threshold, the first UE may further reduce the second time period, and when the average speed of the first initiating UE and the second initiating UE is less than the threshold, the first UE may further increase the second time period, for example, as referred to Figure 3 The combined ranging session 322 discussed in the document. A means for reducing a first time period when the average speed of the first initiating UE and the second initiating UE is greater than a threshold and increasing the first time period when the average speed of the first initiating UE and the second initiating UE is less than the threshold, and a means for reducing a second time period when the average speed of the first initiating UE and the second initiating UE is greater than the threshold and increasing the second time period when the average speed of the first initiating UE and the second initiating UE is less than the threshold, these means may be, for example, one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a T1 / T2 determination module 434. In one implementation, the first UE may send an indication of a second time period to the first initiating UE and the second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period, for example, as referred to Figure 3The combined ranging session 322 discussed in the text. An apparatus for sending an indication of a second time period to a first initiating UE and a second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a T1 / T2 determination module 434.

[0098] As an example, a first UE may receive a fourth or more pre-ranging messages from UEs in a third set of ranging sessions in response to a third or more pre-ranging messages broadcast by the UE, for example, as referred to Figure 2 The first 204 PRS and Figure 3 This is discussed in the PRS pre-message 324 of the combined ranging session 322. The first UE may broadcast a first plurality of ranging signals in the third ranging session set, and may receive a second plurality of ranging signals from the UEs in the third ranging session set in response to the first plurality of ranging signals broadcast by the UE, for example, as referred to Figure 2 PRS 206 and Figure 3 This is discussed in PRS message 326 within the combined ranging session 322. The first UE may broadcast a first plurality of post-ranging signals in the third ranging session set, and may receive a second plurality of post-ranging signals from UEs in the third ranging session set in response to the first plurality of post-ranging signals broadcast by the UE, for example, as referred to... Figure 2 PRS after 208 and Figure 3The PRS post-message 328 discussed in the combined ranging session 322. An apparatus for receiving a fourth plurality of ranging pre-message messages from a UE in a third ranging session set in response to a third plurality of ranging pre-message messages broadcast by the UE may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS pre-message module 422. An apparatus for broadcasting a first plurality of ranging signals in a third ranging session set and for receiving a second plurality of ranging signals from a UE in the third ranging session set in response to the first plurality of ranging signals broadcast by the UE may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS module 424. An apparatus for broadcasting a first plurality of post-range signals in a third ranging session set and an apparatus for receiving a second plurality of post-range signals from a UE in the third ranging session set in response to the first plurality of post-range signals broadcast by a UE, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS post-message module 426.

[0099] Figure 6 This is a flowchart 600 illustrating a method for performing ranging by the first UE in a distributed user equipment (UE) system. For example, the first UE could be... Figure 3 UEX or Figure 4 UE 400 in the middle.

[0100] In box 602, the first UE initiates the first ranging session set by broadcasting a first pre-ranging message identifying the first UE and the first plurality of responding UEs in each ranging session of the first set containing the first ranging session, such as referring to Figure 3 The discussion is focused on the PRS pre-message 304 in the ranging session 302. An apparatus for initiating a first ranging session set by broadcasting a first pre-message message identifying a first UE and a first plurality of responding UEs in each ranging session within a first set containing first ranging sessions, the apparatus being, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS pre-message module 422.

[0101] In block 604, the first UE receives a second pre-rangement message from the second UE to initiate a second ranging session set. The second pre-rangement message from the second UE identifies the second UE and a plurality of responding UEs in the second ranging session. The plurality of responding UEs includes the first UE, a third UE initiating a third ranging session set, and responding UEs from the first ranging session set and the third ranging session set, such as references. Figure 3 This is discussed in the PRS pre-message 324 of the combined ranging session 322. For example, a second UE may be included in a first plurality of responding UEs, and the second UE may be an anchor UE with a known location, which is provided to the first UE for positioning, for example, as referred to Figure 3 The discussion is based on the PRS post-message 308 in the mid-range session 302. An apparatus for receiving a second pre-range message from a second UE to initiate a second range session set, the second pre-range message from the second UE identifying the second UE and a plurality of responding UEs in the second range session, the plurality of responding UEs including a first UE, a third UE initiating a third range session set, and responding UEs from the first and third range session sets, the apparatus may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as combining a range module 436, a range module 421, and a PRS pre-message module 422.

[0102] In box 606, the first UE terminates the initiation of the first ranging session set in response to receiving from the second UE one of the second pre-ranging messages used to initiate the second ranging session set, for example, as shown in reference Figure 3 The combined ranging session 322 discussed in the section. An apparatus for terminating the initiation of a first ranging session set in response to receiving from a second UE one of a second pre-ranging message for initiating a second ranging session set, the apparatus may be, for example, one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as combined ranging module 436 and ranging module 421.

[0103] In one implementation, the first UE may initiate a fourth ranging session set after the second ranging session set has terminated, for example, as shown in reference Figure 3The combined ranging session 322 discussed in the text. An apparatus for initiating a fourth ranging session set after the termination of a second ranging session set may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a combined ranging module 436 and a ranging module 421. For example, the fourth ranging session set may be initiated in response to termination of receiving a second pre-ranging message from a second UE to initiate the second ranging session set, for example, as referred to Figure 3 This is discussed in the context of combined ranging session 322. In another example, the first UE may receive an indication of a time period for a second ranging session set, wherein a fourth ranging session set is initiated after the expiration of that time period, for example, as referred to Figure 3 The combined ranging session 322 discussed in the example. For example, in one implementation, the length of the time period may be based on the speeds of the first UE and the third UE. An apparatus for receiving an indication of a time period for a second ranging session set, wherein a fourth ranging session set is initiated after the expiration of the time period, may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a combined ranging module 436, a ranging module 421, and a PRS pre-messaging module 422.

[0104] In one implementation, the responding UE from the first ranging session set and the third ranging session set can be any responding UE from the first plurality of responding UEs and the third ranging session set that is not included in the first plurality of responding UEs, for example, as referred to Figure 3 The combined ranging session 322 discussed

[0105] As an example, the first UE may receive a third pre-ranging message from a responding UE in the first ranging session set in response to a first pre-ranging message broadcast by the first UE, for example, as referred to Figure 2 PRS previous message 204 and Figure 3 This is discussed in the PRS pre-message 304 of the ranging session 302. The first UE may broadcast a first plurality of ranging signals and may receive a second plurality of ranging signals from a responding UE in the first ranging session set in response to the first plurality of ranging signals broadcast by the first UE, for example, as referred to Figure 2 PRS message 206 and Figure 3 This is discussed in PRS message 306 within ranging session 302. The first UE may broadcast a first plurality of post-ranging signals and, in response to the first plurality of post-ranging signals broadcast by the first UE, receive a second plurality of post-ranging signals from a responding UE in the first ranging session set, for example, as referred to... Figure 2PRS message 208 and Figure 3 The discussion is based on the PRS post-message 308 in ranging session 302. An apparatus for receiving a third pre-ranging message from a responding UE in a first ranging session set in response to a first pre-ranging message broadcast by a first UE may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS pre-message module 422. An apparatus for broadcasting a first plurality of ranging signals and an apparatus for receiving a second plurality of ranging signals from a responding UE in a first ranging session set in response to the first plurality of ranging signals broadcast by a first UE may be, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS module 424. An apparatus for broadcasting a first plurality of post-ranging signals and an apparatus for receiving a second plurality of post-ranging signals from a responding UE in a first ranging session set in response to the first plurality of post-ranging signals broadcast by a first UE, the apparatus being, for example, a transceiver 414 and one or more processors 402 having dedicated hardware or implementing executable code or software instructions in memory 404 and / or medium 420, such as a ranging module 421 and a PRS post-message module 426.

[0106] Throughout this specification, the terms "an example," "an example," "some examples," or "exemplary implementation" mean that a particular feature, structure, or characteristic described in conjunction with a feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Therefore, phrases appearing throughout the specification such as "an example," "an example," "some examples," or "in some implementations," or other similar phrases, do not necessarily all refer to the same feature, example, and / or limitation. Furthermore, these particular features, structures, or characteristics may be combined in one or more examples and / or features.

[0107] Some portions of the detailed description included herein are presented in the form of algorithms or symbolic representations of operations on binary digital signals stored in the memory of a particular device or dedicated computing device or platform. In the context of this particular specification, the terms "particular device," etc., include general-purpose computers once programmed to perform specific operations according to instructions from program software. Algorithm descriptions or symbolic representations are examples of techniques used by those skilled in the art of signal processing or related fields to convey the essence of their work to others skilled in the art. An algorithm here is generally considered to be a self-consistent sequence of operations or similar signal processing that leads to a desired result. In this context, the operation or processing involves the physical manipulation of physical quantities. Typically, but not necessarily, such quantities may take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, or otherwise manipulated. It has proven convenient at times to refer to such signals as bits, data, values, elements, symbols, characters, items, numbers, numerical values, etc., primarily for reasons of general use. However, it should be understood that all such terms, or similar terms, are to be associated with the appropriate physical quantity and are merely convenient labels. Unless otherwise specifically stated, as will be apparent from the discussion herein, throughout this specification, the use of terms such as “processing,” “calculating,” “determining,” and “determining” refers to the actions or processes of a particular device (such as a dedicated computer, dedicated computing device, or similar dedicated electronic computing device). In the context of this specification, therefore, a dedicated computer or similar dedicated electronic computing device is capable of manipulating or transforming signals that are generally represented as physical electronic or magnetic quantities within the memory, registers, or other information storage, transmission, or display devices of such dedicated computer or similar dedicated electronic computing device.

[0108] In the detailed description above, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter can be practiced without these specific details. In other instances, methods and apparatus known to those of ordinary skill in the art have not been described in detail to avoid obscuring the claimed subject matter.

[0109] As used herein, the terms “and,” “or,” and “and / or” may include a variety of meanings, which are also contemplated, at least in part, depending on the context in which such terms are used. Generally, “or,” when used to relate a list such as A, B, or C, is intended to mean A, B, and C (in the inclusive sense) and A, B, or C (in the exclusive sense). Additionally, the term “one or more” as used herein may be used to describe any feature, structure, or property in the singular form, or to describe multiple features, structures, or characteristics, or some other combination thereof. However, it should be noted that this is merely an illustrative example, and the claimed subject matter is not limited to this example.

[0110] While the features currently considered exemplary have been explained and described, those skilled in the art will understand that various other modifications can be made and equivalents can be substituted without departing from the claimed subject matter. Additionally, numerous modifications can be made to adapt a particular scenario to the teachings of the claimed subject matter without departing from the central concepts described herein.

[0111] Examples of implementations are described in the following numbered clauses:

[0112] 1. A ranging method performed by a first UE in a distributed user equipment (UE) system, the method comprising:

[0113] Monitor a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set;

[0114] Monitor a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and

[0115] The third ranging session set is initiated by broadcasting a third pre-ranging message to identify the UE in the third ranging session set. The third ranging session set includes UEs in the first ranging session set and UEs in the second ranging session set.

[0116] 2. The method of Clause 1, wherein the first UE is an anchor UE with a known location, and the first UE provides the known location to the first initiating UE and the second initiating UE for positioning.

[0117] 3. The method of either clause 1 or 2, wherein the first and second ranging session sets are terminated in response to the initiation of the third ranging session set.

[0118] 4. The method of any of Clauses 1-3 further includes: determining the speeds of the first initiating UE and the second initiating UE while monitoring the first ranging session and the second ranging session.

[0119] 5. The method of Clause 4, wherein the first ranging session set and the second ranging session set are monitored for a first time period, and wherein the third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speed of the first initiating UE and the second initiating UE.

[0120] 6. The method as described in Clause 5 further includes:

[0121] The first time period is decreased when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and the first time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold; and

[0122] The second time period is reduced when the average speed of the first initiating UE and the second initiating UE is greater than the threshold, and the second time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

[0123] 7. The method as described in Clause 5 further includes:

[0124] Instructions for a second time period are sent to the first initiating UE and the second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

[0125] 8. The method of any of Clauses 1-7 further includes:

[0126] In response to a third pre-ranging message broadcast by the UE, a fourth pre-ranging message is received from the UE in the third ranging session set;

[0127] Broadcast the first plurality of ranging signals in the third ranging session set;

[0128] In response to a first plurality of ranging signals broadcast by the UE, a second plurality of ranging signals are received from the UE in the third ranging session set;

[0129] Broadcast the first plurality of post-range signals in the third ranging session set; and

[0130] In response to the first plurality of ranging post-signals broadcast by the UE, a second plurality of ranging post-signals are received from the UE in the third ranging session set.

[0131] 9. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising:

[0132] A wireless transceiver configured to communicate wirelessly with entities in a wireless network;

[0133] At least one memory; and

[0134] At least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to:

[0135] Monitor a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set;

[0136] Monitor a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and

[0137] The third ranging session set is initiated by being configured to broadcast a third plurality of pre-ranging messages identifying UEs in the third ranging session set via the radio transceiver. The third ranging session set includes UEs in the first ranging session set and UEs in the second ranging session set.

[0138] 10. The first UE as described in Clause 9, wherein the first UE is an anchor UE with a known location, and the first UE provides the known location to the first initiating UE and the second initiating UE for positioning.

[0139] 11. The first UE as in either clause 9 or 10, wherein the first ranging session set and the second ranging session set are terminated in response to the initiation of the third ranging session set.

[0140] 12. The first UE as in any of Clauses 9-11, wherein the at least one processor is further configured to: determine the speed of the first initiating UE and the second initiating UE while monitoring the first ranging session and the second ranging session.

[0141] 13. The first UE as described in Clause 12, wherein the first ranging session set and the second ranging session set are monitored for a first time period, and wherein the third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speed of the first initiating UE and the second initiating UE.

[0142] 14. The first UE as described in Clause 13, wherein the at least one processor is further configured to:

[0143] The first time period is decreased when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and the first time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold; and

[0144] The second time period is reduced when the average speed of the first initiating UE and the second initiating UE is greater than the threshold, and the second time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

[0145] 15. The first UE as described in Clause 13, wherein the at least one processor is further configured to:

[0146] Instructions for a second time period are sent to the first initiating UE and the second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

[0147] 16. The first UE as described in any of clauses 9-15, wherein the at least one processor is further configured to:

[0148] In response to a third pre-ranging message broadcast by the UE, a fourth pre-ranging message is received from the UE in the third ranging session set;

[0149] Broadcast the first plurality of ranging signals in the third ranging session set;

[0150] In response to a first plurality of ranging signals broadcast by the UE, a second plurality of ranging signals are received from the UE in the third ranging session set;

[0151] Broadcast the first plurality of post-range signals in the third ranging session set; and

[0152] In response to the first plurality of ranging post-signals broadcast by the UE, a second plurality of ranging post-signals are received from the UE in the third ranging session set.

[0153] 17. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising:

[0154] A means for monitoring a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set;

[0155] A means for monitoring a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and

[0156] A means for initiating a third ranging session set by broadcasting a third plurality of pre-ranging messages identifying UEs in a third ranging session set, the third ranging session set including UEs in a first ranging session set and UEs in a second ranging session set.

[0157] 18. The first UE as in Clause 17, wherein the first UE is an anchor UE with a known location, the first UE providing the known location to the first initiating UE and the second initiating UE for positioning.

[0158] 19. The first UE as in either Clause 17 or 18, wherein the first ranging session set and the second ranging session set are terminated in response to the initiation of the third ranging session set.

[0159] 20. The first UE as described in any of Clauses 17-19, further comprising: means for determining the speeds of the first initiating UE and the second initiating UE while monitoring the first ranging session and the second ranging session.

[0160] 21. The first UE as described in Clause 20, wherein a first ranging session set and a second ranging session set are monitored for a first time period, and wherein a third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speed of the first initiating UE and the second initiating UE.

[0161] 22. As in the first UE of Clause 21, further comprising:

[0162] A means for decreasing a first time period when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and increasing the first time period when the average speed of the first initiating UE and the second initiating UE is less than the threshold; and

[0163] An apparatus for decreasing a second time period when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and increasing the second time period when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

[0164] 23. As in the first UE of Clause 21, further comprising:

[0165] A means for sending an indication of a second time period to a first initiating UE and a second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

[0166] 24. The first UE as described in any of Clauses 17-23 further includes:

[0167] A means for receiving a fourth or more ranging pre-measuring message from a UE in a third ranging session set in response to a third or more ranging pre-measuring message broadcast by a UE;

[0168] A means for broadcasting a first plurality of ranging signals in a third ranging session set;

[0169] A means for receiving a second plurality of ranging signals from a UE in a third ranging session set in response to a first plurality of ranging signals broadcast by a UE;

[0170] A means for broadcasting a first plurality of post-ranged signals in a third ranging session set; and

[0171] A means for receiving a second plurality of ranging signals from a UE in a third ranging session set in response to a first plurality of ranging signals broadcast by a UE.

[0172] 25. A non-transient storage medium including program code stored thereon, the program code being operable to configure at least one processor in a first user equipment (UE) for ranging in a distributed UE system, the program code including instructions for the following operations:

[0173] Monitor a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set;

[0174] Monitor a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; and

[0175] The third ranging session set is initiated by broadcasting a third pre-ranging message to identify the UE in the third ranging session set. The third ranging session set includes UEs in the first ranging session set and UEs in the second ranging session set.

[0176] 26. A non-transient storage medium including program code as described in Clause 25, wherein the first UE is an anchor UE having a known location, and the first UE provides the known location to a first initiating UE and a second initiating UE for positioning.

[0177] 27. A non-transient storage medium including program code, such as that in any of Clauses 25 or 26, wherein the first and second ranging session sets are terminated in response to the initiation of the third ranging session set.

[0178] 28. A non-transient storage medium including program code, such as any of Clauses 25-27, further comprising: determining the speeds of the first initiating UE and the second initiating UE while monitoring the first ranging session and the second ranging session.

[0179] 29. A non-transient storage medium including program code as described in Clause 28, wherein a first ranging session set and a second ranging session set are monitored for a first time period, and wherein a third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speeds of the first initiating UE and the second initiating UE.

[0180] 30. The non-transient storage medium including program code as described in Clause 29 further includes instructions for the following operations:

[0181] The first time period is decreased when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and the first time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold; and

[0182] The second time period is reduced when the average speed of the first initiating UE and the second initiating UE is greater than the threshold, and the second time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

[0183] 31. The non-transient storage medium including program code as described in Clause 29 further includes instructions for the following operations:

[0184] Instructions for a second time period are sent to the first initiating UE and the second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

[0185] 32. A non-transient storage medium comprising program code, such as that described in any of Clauses 25-31, further comprises instructions for the following operations:

[0186] In response to a third pre-ranging message broadcast by the UE, a fourth pre-ranging message is received from the UE in the third ranging session set;

[0187] Broadcast the first plurality of ranging signals in the third ranging session set;

[0188] In response to a first plurality of ranging signals broadcast by the UE, a second plurality of ranging signals are received from the UE in the third ranging session set;

[0189] Broadcast the first plurality of post-range signals in the third ranging session set; and

[0190] In response to the first plurality of ranging post-signals broadcast by the UE, a second plurality of ranging post-signals are received from the UE in the third ranging session set.

[0191] 33. A ranging method performed by a first UE in a distributed user equipment (UE) system, the method comprising:

[0192] The first set of ranging sessions is initiated by broadcasting a first pre-ranging message in each ranging session of the first set containing the first ranging session, identifying the first UE and the first plurality of responding UEs in each ranging session.

[0193] The second UE receives a second pre-range message for initiating a second ranging session set. The second pre-range message from the second UE identifies the second UE and a plurality of responding UEs in the second ranging session. The plurality of responding UEs includes a first UE, a third UE initiating a third ranging session set, and responding UEs from both the first and third ranging session sets.

[0194] The initiation of the first ranging session set is terminated in response to receiving one of the second ranging pre-message messages used to initiate the second ranging session set from the second UE.

[0195] 34. The method of Clause 33, wherein the second UE is included in the first plurality of responding UEs, the second UE being an anchor UE having a known location which is provided to the first UE for positioning.

[0196] 35. The method of any of Clauses 33 or 34 further includes: initiating a fourth ranging session set after the termination of the second ranging session set.

[0197] 36. The method of Clause 35, wherein the fourth ranging session set is initiated in response to the termination of receiving a second ranging pre-messaging message from the second UE to initiate the second ranging session set.

[0198] 37. The method of Clause 35 further includes: receiving an indication of a time period for a second ranging session set, wherein a fourth ranging session set is initiated after the expiration of the time period.

[0199] 38. The method of Clause 37, wherein the length of the time period is based on the speeds of the first UE and the third UE.

[0200] 39. The method of any of Clauses 33-38, wherein the responding UEs from the first ranging session set and the third ranging session set include the first plurality of responding UEs and any responding UEs in the third ranging session set not included in the first plurality of responding UEs.

[0201] 40. The method of any of Clauses 33-39 further includes:

[0202] In response to a first ranging pre-message broadcast by a first UE, a third ranging pre-message message is received from a responding UE in a first ranging session set;

[0203] Broadcast the first multiple ranging signals;

[0204] In response to a first plurality of ranging signals broadcast by a first UE, a second plurality of ranging signals are received from a responding UE in a first ranging session set.

[0205] Broadcast the first multiple ranging signals; and

[0206] In response to a first plurality of ranging post-signals broadcast by a first UE, a second plurality of ranging post-signals are received from a responding UE in a first ranging session set.

[0207] 41. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising:

[0208] A wireless transceiver configured to communicate wirelessly with entities in a wireless network;

[0209] At least one memory; and

[0210] At least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to:

[0211] The first set of ranging sessions is initiated by broadcasting a first pre-ranging message in each ranging session of the first set containing the first ranging session, identifying the first UE and the first plurality of responding UEs in each ranging session.

[0212] The second UE receives a second pre-range message for initiating a second ranging session set. The second pre-range message from the second UE identifies the second UE and a plurality of responding UEs in the second ranging session. The plurality of responding UEs includes a first UE, a third UE initiating a third ranging session set, and responding UEs from both the first and third ranging session sets.

[0213] The initiation of the first ranging session set is terminated in response to receiving one of the second ranging pre-message messages used to initiate the second ranging session set from the second UE.

[0214] 42. The first UE as in Clause 41, wherein the second UE is included in the first plurality of responding UEs, the second UE being an anchor UE having a known location which is provided to the first UE for positioning.

[0215] 43. The first UE as in either clause 41 or 42, wherein the at least one processor is further configured to initiate a fourth ranging session set after the termination of the second ranging session set.

[0216] 44. The first UE as described in Clause 43, wherein the fourth ranging session set is initiated in response to the termination of receiving a second ranging pre-messaging message from the second UE to initiate the second ranging session set.

[0217] 45. The first UE as described in Clause 43, wherein the at least one processor is further configured to: receive an indication of a time period for a second ranging session set, wherein a fourth ranging session set is initiated after the expiration of the time period.

[0218] 46. ​​The first UE as in Clause 45, wherein the length of the time period is based on the speeds of the first UE and the third UE.

[0219] 47. The first UE as in any of Clauses 41-46, wherein the responding UEs from the first ranging session set and the third ranging session set include the first plurality of responding UEs and any responding UEs in the third ranging session set that are not included in the first plurality of responding UEs.

[0220] 48. The first UE as described in any of clauses 41-47, wherein the at least one processor is further configured to:

[0221] In response to a first ranging pre-message broadcast by a first UE, a third ranging pre-message message is received from a responding UE in a first ranging session set;

[0222] Broadcast the first multiple ranging signals;

[0223] In response to a first plurality of ranging signals broadcast by a first UE, a second plurality of ranging signals are received from a responding UE in a first ranging session set.

[0224] Broadcast the first multiple ranging signals; and

[0225] In response to a first plurality of ranging post-signals broadcast by a first UE, a second plurality of ranging post-signals are received from a responding UE in a first ranging session set.

[0226] 49. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising:

[0227] A means for initiating a first set of ranging sessions by broadcasting a first pre-ranging message identifying a first UE and a first plurality of responding UEs in each ranging session of a first set of ranging sessions;

[0228] A means for receiving a second pre-ranging message from a second UE for initiating a second ranging session set, wherein the second pre-ranging message from the second UE identifies the second UE and a plurality of responding UEs in the second ranging session, the plurality of responding UEs including a first UE, a third UE initiating a third ranging session set, and responding UEs from the first ranging session set and the third ranging session set; and

[0229] A means for terminating the initiation of a first ranging session set in response to receiving from a second UE one of a second pre-ranging message for initiating a second ranging session set.

[0230] 50. The first UE as in Clause 49, wherein the second UE is included in the first plurality of responding UEs, the second UE being an anchor UE having a known location which is provided to the first UE for positioning.

[0231] 51. The first UE as described in any of Clauses 49 or 50, further comprising: means for initiating a fourth ranging session set after the termination of the second ranging session set.

[0232] 52. The first UE as described in Clause 51, wherein the fourth ranging session set is initiated in response to the termination of receiving a second ranging pre-messaging message from the second UE to initiate the second ranging session set.

[0233] 53. The first UE as described in Clause 51 further includes: means for receiving an indication of a time period for a second ranging session set, wherein a fourth ranging session set is initiated after the expiration of the time period.

[0234] 54. The first UE as in Clause 53, wherein the length of the time period is based on the speeds of the first UE and the third UE.

[0235] 55. The first UE as in any of Clauses 49-54, wherein the responding UEs from the first ranging session set and the third ranging session set include the first plurality of responding UEs and any responding UEs in the third ranging session set not included in the first plurality of responding UEs.

[0236] 56. The first UE, as in any of clauses 49-55, further includes:

[0237] A means for receiving a third ranging pre-message message from a responding UE in a first ranging session set in response to a first ranging pre-message message broadcast by a first UE;

[0238] A device for broadcasting the first plurality of ranging signals;

[0239] A means for receiving a second plurality of ranging signals from a responding UE in a first ranging session set in response to a first plurality of ranging signals broadcast by a first UE;

[0240] A means for broadcasting the first plurality of ranging signals; and

[0241] A means for receiving a second plurality of ranging signals from a responding UE in a first ranging session set in response to a first plurality of ranging signals broadcast by a first UE.

[0242] 57. A non-transient storage medium including program code stored thereon, the program code being operable to configure at least one processor in a first user equipment (UE) for ranging in a distributed UE system, the program code including instructions for the following operations:

[0243] The first set of ranging sessions is initiated by broadcasting a first pre-ranging message in each ranging session of the first set containing the first ranging session, identifying the first UE and the first plurality of responding UEs in each ranging session.

[0244] The second UE receives a second pre-range message for initiating a second ranging session set. The second pre-range message from the second UE identifies the second UE and a plurality of responding UEs in the second ranging session. The plurality of responding UEs includes a first UE, a third UE initiating a third ranging session set, and responding UEs from both the first and third ranging session sets.

[0245] The initiation of the first ranging session set is terminated in response to receiving one of the second ranging pre-message messages used to initiate the second ranging session set from the second UE.

[0246] 58. A non-transient storage medium including program code as described in Clause 57, wherein a second UE is included in a first plurality of responding UEs, the second UE being an anchor UE having a known location provided to the first UE for positioning.

[0247] 59. The non-transient storage medium including program code as described in Clauses 57 or 58 further includes instructions for initiating a fourth ranging session set after the termination of the second ranging session set.

[0248] 60. A non-transient storage medium including program code, as in Clause 59, wherein a fourth ranging session set is initiated in response to termination of receiving a second pre-ranging message from the second UE to initiate a second ranging session set.

[0249] 61. The non-transient storage medium including program code as described in Clause 59 further includes instructions for receiving an indication of a time period for a second ranging session set, wherein a fourth ranging session set is initiated after the expiration of that time period.

[0250] 62. A non-transient storage medium including program code, as in Clause 61, wherein the length of the time period is based on the speeds of the first UE and the third UE.

[0251] 63. A non-transient storage medium including program code, such as any of the provisions 57-62, wherein the responding UEs from the first ranging session set and the third ranging session set include the first plurality of responding UEs and any responding UEs in the third ranging session set not included in the first plurality of responding UEs.

[0252] 64. A non-transient storage medium comprising program code, such as any of clauses 57-63, further comprising instructions for the following operations:

[0253] In response to a first ranging pre-message broadcast by a first UE, a third ranging pre-message message is received from a responding UE in a first ranging session set;

[0254] Broadcast the first multiple ranging signals;

[0255] In response to a first plurality of ranging signals broadcast by a first UE, a second plurality of ranging signals are received from a responding UE in a first ranging session set.

[0256] Broadcast the first multiple ranging signals; and

[0257] In response to a first plurality of ranging post-signals broadcast by a first UE, a second plurality of ranging post-signals are received from a responding UE in a first ranging session set.

[0258] Therefore, the subject matter claimed is not intended to be limited to the specific examples disclosed, but may also include all aspects falling within the scope of the appended claims and their equivalents.

Claims

1. A ranging method performed by a first UE in a distributed user equipment (UE) system, the method comprising: Monitor a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; Monitor a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; as well as The third ranging session set is initiated by broadcasting a third plurality of pre-ranging messages identifying the UEs in the third ranging session set, the third ranging session set including the UEs in the first ranging session set and the UEs in the second ranging session set.

2. The method of claim 1, wherein the first UE is an anchor UE with a known location, and the first UE provides the known location to the first initiating UE and the second initiating UE for positioning.

3. The method of claim 1, wherein the first ranging session set and the second ranging session set are terminated in response to the initiation of the third ranging session set.

4. The method of claim 1, further comprising: While monitoring the first ranging session and the second ranging session, determine the speeds of the first initiating UE and the second initiating UE.

5. The method of claim 4, wherein the first ranging session set and the second ranging session set are monitored for a first time period, and wherein the third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speeds of the first initiating UE and the second initiating UE.

6. The method of claim 5, further comprising: The first time period is decreased when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and the first time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold; and The second time period is reduced when the average speed of the first initiating UE and the second initiating UE is greater than the threshold, and the second time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

7. The method of claim 5, further comprising: Instructions for the second time period are sent to the first initiating UE and the second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

8. The method of claim 1, further comprising: In response to the third plurality of ranging pre-messaging messages broadcast by the UE, a fourth plurality of ranging pre-messaging messages are received from the UE in the third ranging session set; Broadcast the first plurality of ranging signals in the third ranging session set; In response to the first plurality of ranging signals broadcast by the UE, a second plurality of ranging signals are received from the UE in the third ranging session set; Broadcast the first plurality of post-range signals in the third ranging session set; as well as In response to the first plurality of ranging post-signals broadcast by the UE, a second plurality of ranging post-signals are received from the UE in the third ranging session set.

9. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising: A wireless transceiver configured to communicate wirelessly with an entity in a wireless network; At least one memory; as well as At least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: Monitor a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; Monitor a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; as well as The third ranging session set is initiated by being configured to broadcast a third plurality of pre-ranging messages identifying UEs in the third ranging session set via the radio transceiver, the third ranging session set including UEs in the first ranging session set and UEs in the second ranging session set.

10. The first UE as claimed in claim 9, wherein: The first UE is an anchor UE with a known location, and the first UE provides the known location to the first initiating UE and the second initiating UE for positioning.

11. The first UE as claimed in claim 9, wherein: The first ranging session set and the second ranging session set are terminated in response to the initiation of the third ranging session set.

12. The first UE of claim 9, wherein the at least one processor is further configured to determine the speeds of the first initiating UE and the second initiating UE while monitoring the first ranging session and the second ranging session.

13. The first UE as claimed in claim 12, wherein: The first ranging session set and the second ranging session set are monitored for a first time period, and the third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speed of the first initiating UE and the second initiating UE.

14. The first UE of claim 13, wherein the at least one processor is further configured to: The first time period is decreased when the average speed of the first initiating UE and the second initiating UE is greater than a threshold, and the first time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold; and The second time period is reduced when the average speed of the first initiating UE and the second initiating UE is greater than the threshold, and the second time period is increased when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

15. The first UE of claim 13, wherein the at least one processor is further configured to: Instructions for the second time period are sent to the first initiating UE and the second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

16. The first UE of claim 9, wherein the at least one processor is further configured to: In response to the third plurality of ranging pre-messaging messages broadcast by the UE, a fourth plurality of ranging pre-messaging messages are received from the UE in the third ranging session set; Broadcast the first plurality of ranging signals in the third ranging session set; In response to the first plurality of ranging signals broadcast by the UE, a second plurality of ranging signals are received from the UE in the third ranging session set; Broadcast the first plurality of post-range signals in the third ranging session set; as well as In response to the first plurality of ranging post-signals broadcast by the UE, a second plurality of ranging post-signals are received from the UE in the third ranging session set.

17. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising: A means for monitoring a first ranging session set initiated by a first initiating UE, the first ranging session set including a first plurality of pre-ranging messages broadcast by the first initiating UE identifying UEs in the first ranging session set; A means for monitoring a second ranging session set initiated by a second initiating UE, the second ranging session set including a second plurality of pre-ranging messages broadcast by the second initiating UE identifying UEs in the second ranging session set; as well as A means for initiating a third ranging session set by broadcasting a third plurality of pre-ranging messages identifying UEs in a third ranging session set, the third ranging session set including UEs in a first ranging session set and UEs in a second ranging session set.

18. The first UE as claimed in claim 17, wherein: The first UE is an anchor UE with a known location, and the first UE provides the known location to the first initiating UE and the second initiating UE for positioning.

19. The first UE as claimed in claim 17, wherein: The first ranging session set and the second ranging session set are terminated in response to the initiation of the third ranging session set.

20. The first UE as claimed in claim 17, further comprising: A means for determining the speeds of a first initiating UE and a second initiating UE while monitoring a first ranging session and a second ranging session, wherein the first ranging session set and the second ranging session set are monitored for a first time period, and wherein a third ranging session set is executed for a second time period, wherein the first time period and the second time period are based on the speeds of the first initiating UE and the second initiating UE.

21. The first UE as claimed in claim 20, further comprising: An apparatus for decreasing the first time period when the average speed of the first initiating UE and the second initiating UE is greater than a threshold and increasing the first time period when the average speed of the first initiating UE and the second initiating UE is less than the threshold; as well as An apparatus for decreasing the second time period when the average speed of the first initiating UE and the second initiating UE is greater than the threshold, and for increasing the second time period when the average speed of the first initiating UE and the second initiating UE is less than the threshold.

22. The first UE as claimed in claim 20, further comprising: A means for sending an indication of a second time period to a first initiating UE and a second initiating UE, wherein the first initiating UE initiates a fourth ranging session after the second time period, and the second initiating UE initiates a fifth ranging session after the second time period.

23. A ranging method performed by a first UE in a distributed user equipment (UE) system, the method comprising: The first ranging session set is initiated by broadcasting a first pre-ranging message in each ranging session of the first set containing the first ranging session, identifying the first UE and the first plurality of responding UEs. The second UE receives a second pre-range message for initiating a second range session set. The second pre-range message from the second UE identifies the second UE and a plurality of responding UEs in the second range session. The plurality of responding UEs include the first UE, a third UE that initiates a third range session set, and responding UEs from the first range session set and the third range session set. as well as The initiation of the first ranging session set is terminated in response to receiving one of the second pre-ranging messages used to initiate the second ranging session set from the second UE.

24. The method of claim 23, wherein the second UE is included in the first plurality of responder UEs, the second UE being an anchor UE having a known location, the known location being provided to the first UE for positioning.

25. The method of claim 23, further comprising: A fourth ranging session set is initiated after the second ranging session set terminates.

26. The method of claim 25, wherein the fourth ranging session set is initiated in response to terminating the receipt from the second UE of the second pre-ranging message used to initiate the second ranging session set.

27. The method of claim 25, further comprising: Receive an indication of a time period for the second ranging session set, wherein the fourth ranging session set is initiated after the time period expires.

28. The method of claim 27, wherein the length of the time period is based on the speeds of the first UE and the third UE.

29. The method of claim 23, wherein the responding UEs from the first ranging session set and the third ranging session set include any responding UEs from the first plurality of responding UEs and the third ranging session set that are not included in the first plurality of responding UEs.

30. The method of claim 23, further comprising: A third ranging pre-message message is received from the responding UE in the first ranging session set in response to the first ranging pre-message message broadcast by the first UE; Broadcast the first multiple ranging signals; In response to the first plurality of ranging signals broadcast by the first UE, a second plurality of ranging signals are received from the responding UE in the first ranging session set; Broadcast the first multiple ranging signals; as well as In response to the first plurality of ranging post-signals broadcast by the first UE, a second plurality of ranging post-signals are received from the responding UE in the first ranging session set.

31. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising: A wireless transceiver configured to communicate wirelessly with an entity in a wireless network; At least one memory; as well as At least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: The first ranging session set is initiated by broadcasting a first pre-ranging message in each ranging session of the first set containing the first ranging session, identifying the first UE and the first plurality of responding UEs. The second UE receives a second pre-range message for initiating a second range session set. The second pre-range message from the second UE identifies the second UE and a plurality of responding UEs in the second range session. The plurality of responding UEs include the first UE, a third UE that initiates a third range session set, and responding UEs from the first range session set and the third range session set. as well as The initiation of the first ranging session set is terminated in response to receiving one of the second pre-ranging messages used to initiate the second ranging session set from the second UE.

32. The first UE as claimed in claim 31, wherein: The second UE is included in the first plurality of responder UEs, and the second UE is an anchor UE with a known location, which is provided to the first UE for positioning.

33. The first UE of claim 31, wherein the at least one processor is further configured to initiate a fourth ranging session set after the second ranging session set has terminated.

34. The first UE as claimed in claim 33, wherein: The fourth ranging session set is initiated in response to the termination of receiving the second ranging pre-messaging message from the second UE to initiate the second ranging session set.

35. The first UE of claim 33, wherein the at least one processor is further configured to receive an indication of a time period for the second ranging session set, wherein the fourth ranging session set is initiated after the time period expires.

36. The first UE as claimed in claim 35, wherein: The length of the time period is based on the speeds of the first UE and the third UE.

37. The first UE as claimed in claim 31, wherein: The responding UEs from the first ranging session set and the third ranging session set include the first plurality of responding UEs and any responding UEs in the third ranging session set that are not included in the first plurality of responding UEs.

38. The first UE of claim 31, wherein the at least one processor is further configured to: A third ranging pre-message message is received from the responding UE in the first ranging session set in response to the first ranging pre-message message broadcast by the first UE; Broadcast the first multiple ranging signals; In response to the first plurality of ranging signals broadcast by the first UE, a second plurality of ranging signals are received from the responding UE in the first ranging session set; Broadcast the first multiple ranging signals; as well as In response to the first plurality of ranging post-signals broadcast by the first UE, a second plurality of ranging post-signals are received from the responding UE in the first ranging session set.

39. A first UE configured to perform ranging in a distributed user equipment (UE) system, the first UE comprising: A means for initiating a first ranging session set by broadcasting a first pre-ranging message identifying the first UE and a first plurality of responding UEs in each ranging session of a first set containing the first ranging session; A means for receiving a second pre-range message from a second UE for initiating a second range session set, wherein the second pre-range message from the second UE identifies the second UE and a plurality of responding UEs in the second range session, the plurality of responding UEs including the first UE, a third UE initiating a third range session set, and responding UEs from the first range session set and the third range session set. as well as A means for terminating the initiation of the first ranging session set in response to receiving from the second UE one of the second pre-ranging messages used to initiate the second ranging session set.

40. The first UE as claimed in claim 39, wherein: The second UE is included in the first plurality of responder UEs, and the second UE is an anchor UE with a known location, which is provided to the first UE for positioning.

41. The first UE as claimed in claim 39, further comprising: Means for initiating a fourth ranging session set after the termination of the second ranging session set, wherein the fourth ranging session set is initiated in response to the termination of receiving the second ranging pre-messaging message from the second UE for initiating the second ranging session set.

42. The first UE as claimed in claim 39, further comprising: The first UE further includes means for initiating a fourth ranging session set after the termination of the second ranging session set, wherein the fourth ranging session set is initiated after the expiration of the second ranging session set, and wherein the length of the time period is based on the speeds of the first UE and the third UE.

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