Scheme for avoiding periodic resource collisions

Abstract

Systems, methods, and circuitry for performing UE autonomous selection in a vehicle-to-everything (V2X) communication environment includes one or more processors configured to schedule resources for a non-contiguous periodic transmission having scheduled non-contiguous time periods in which scheduled resources are not transmitted. The one or more processors are further configured to perform a monitoring operation during the scheduled non-contiguous time periods, the monitoring operation including monitoring for a collision of scheduled resources of the evaluating UE with scheduled resources of a competing UE, and selectively performing a corrective action when a collision of scheduled resources of the evaluating UE with scheduled resources of the competing UE is detected during the monitoring operation.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a solution to avoid periodic resource collision. BACKGROUND

[0002] The C-V2X standard was released by the 3GPP standards body to support V2X (i.e., vehicle-to-everything) communications. NR V2X includes two modes of operation, referred to as Mode 1 and Mode 2. Mode 1 handles gNB (e.g., base station) scheduling, while Mode 2 handles autonomous selection. Mode 2 does not require support of cellular infrastructure, and a vehicle can autonomously select a sub-channel for its V2V transmission. SUMMARY

[0003] The present invention provides systems, methods, and circuitry for performing UE autonomous selection in a vehicle-to-everything (V2X) communications environment, the systems, methods, and circuitry comprising one or more processors configured to schedule resources for a non-continuous periodic transmission having a scheduled non-continuous time period in which scheduled resources are not transmitted. The one or more processors are further configured to perform a monitoring operation during the scheduled non-continuous time period, the monitoring operation comprising monitoring for a collision of the scheduled resources of the evaluating UE with scheduled resources of a competing UE, and selectively performing a corrective action when a collision of the scheduled resources of the evaluating UE with the scheduled resources of the competing UE is detected during the monitoring operation. BRIEF DESCRIPTION OF DRAWINGS

[0004] Some examples of circuitry, apparatus, and / or methods will hereinafter be described merely by way of example. In this context, reference will be made to the accompanying drawings.

[0005] Figure 1 is a time-frequency diagram illustrating a two-step sensing and selection for V2X autonomous selection.

[0006] Figure 2 is a diagram illustrating a potential collision problem in V2X autonomous selection for a periodic transmission scheme.

[0007] Figure 3A is a diagram illustrating a non-continuous periodic transmission scheme that addresses the collision problem with a periodic transmission scheme having a V2X autonomous selection procedure according to one aspect.

[0008] Figure 3B is a flow diagram illustrating a non-continuous periodic transmission scheme according to one aspect. Figure 3A

[0009] Figure 4 ​is a diagram illustrating a unique collision condition with V2X autonomous selection when the resource reservation period (RRP) of a contending UE is an integer multiple of the evaluation UE, according to one aspect.

[0010] Figure 5 is a diagram illustrating a unique collision condition with V2X autonomous selection when the RRP of the evaluation UE is an integer multiple of the contending UE, according to one aspect.

[0011] Figure 6 is a flowchart illustrating different corrective actions depending on the relative RRP of the evaluation UE and the contending UE in a V2X autonomous selection procedure using a non-continuous periodic transmission scheme, according to one aspect.

[0012] Figures 7A-7B is a diagram illustrating a non-continuous periodic transmission scheme in an instance where multiple non-continuous resource blocks are scheduled in each transmission period, according to various aspects.

[0013] Figures 8A-8B is a diagram illustrating a non-continuous periodic transmission scheme in an instance where multiple non-continuous resource blocks are scheduled in each transmission period, according to various aspects.

[0014] Figure 9 is a diagram illustrating signaling performed to“skip” a transmission period to implement a non-continuous periodic transmission.

[0015] Figure 10 is a flowchart illustrating the functionality of one or more processors of an evaluation UE performing a self-collision detection scheme using HARQ feedback information.

[0016] Figure 11 is a block diagram illustrating a UE and various components thereof, according to one aspect. DETAILED DESCRIPTION

[0017] The present disclosure is described with reference to the accompanying drawings. The drawings are not drawn to scale and are provided merely to illustrate the present disclosure. Several aspects of the disclosure are described below with reference to example implementations. Various

[0018] As highlighted above, Mode 1 in NR V2X involves direct communication between vehicles, however, these communications are managed by the cellular infrastructure which selects the sub-channels and time slots or radio resources for each V2V transmission. In contrast, Mode 2 in NR V2X does not require support of the cellular infrastructure and vehicles autonomously select the sub-channels and time slots or radio resources for their V2V transmissions. In this framework, the 3GPP standard defines a distributed semi-persistent scheduling scheme that all vehicles must implement.

[0019] C-V2X supports 10MHz channels and 20MHz channels. Channels are divided in time into 1ms sub-frames and each sub-frame is divided into 180KHz resource blocks (RBs). The standard defines a sub-channel as a set of RBs in the same sub-frame. This sub-channel is used to transmit data and control information. Such data is transmitted in transport blocks (TBs) over the physical sidelink shared channel (PSSCH) and control information is transmitted in sidelink control information (SCI) messages over the physical sidelink control channel (PSCCH). A TB contains a complete packet and can occupy one or several sub-channels. Each TB has an SCI associated with it and both are transmitted in the same sub-frame. The SCI occupies a configurable number of RBs and a configurable number of OFDM symbols and includes information such as the modulation and coding scheme (MCS) used to transmit the TB, the RBs occupied by the TB and the resource reservation period (RRP) for the semi-persistent scheduling scheme. This resource reservation period refers to the periodicity with which a vehicle transmits its packets and the period or interval is specified in multiples of 100ms (e.g. 100ms, 200ms,... 1000ms). The information on the SCI is valuable, therefore, the SCI must be received correctly in order to receive and decode the TB.

[0020] In Mode 2, vehicles autonomously select their sub-channels and time slots using a sensing based semi-persistent scheduling (SPS) scheme, where a vehicle reserves the selected sub-channels and time slots for a number of consecutive packet transmissions determined by a reselection counter value. After this number of transmissions, new resources or sub-channels must be selected and reserved. The process by which a vehicle selects and reserves resources is a multi-step process which can be understood with reference to Figure 1 It is noted that, Figure 1 The LTE two-step procedure is shown technically, but for the purpose of understanding the essence, it is sufficient for the purpose of explanation. At a high level, in the sensing step (or Figure 1 sensing window) shown, the UE listens to the channel, i.e. listens to the channel information (SCI of other vehicles) in order to see which resources have been reserved. In the selection step, candidate resources are identified and then selected or reserved.

[0021] More specifically, whenever a new resource needs to be selected, the vehicle can reserve the resource for a time period known as the selection window, such as... Figure 1 As shown. During this time period, the vehicle identifies candidate single-frame resources (CSRs) to reserve. A CSR is a group of adjacent sub-channels within the same subframe where a packet or SCI and TB reside. If “T” is the start time of the time window (i.e., the selection window) where a new resource selection must be performed, the vehicle senses all packets in the previous sensing window, including the 1000 subframes prior to T. The vehicle creates a list of all CSRs (i.e., candidate CSRs) in the sensing window, except for CSRs that meet two criteria: (1) they indicate a resource in an SCI received from another vehicle (indicating that the other vehicle will simultaneously utilize that resource), and (2) the average reference signal received power (RSRP) measured on the RB used to transmit the TB associated with the SCI of the other vehicle is greater than the RSRP threshold. If both conditions are met, the vehicle excludes that particular CSR as a candidate CSR. The vehicle can then perform resource selection for transmissions from the identified candidate resources (CSRs) within the selection window.

[0022] As discussed above, in cases where periodic resource reservations are made, when a vehicle UE initiates a transmission on the selected resource, it does not monitor the sidelink channel due to half-duplex system constraints, and therefore such competing sidelink transmissions may continuously conflict with each other if another vehicle UE selects the same periodic resource for its own sidelink transmission. Figure 2 The diagram illustrates this undesirable conflict situation, where UE 1 and UE 2 correspond to two different vehicles that are transmitting on the same selected time-frequency resource (i.e., the same subchannel at the same time).

[0023] like Figure 2 As shown, the first UE 202 (e.g., UE 1 corresponding to the first vehicle) has a first periodic resource reservation 204 at time t1, while the second UE 206 (e.g., UE 2 corresponding to the second vehicle) has a second periodic resource reservation 208 that occupies the same time-frequency resources as the first resource reservation 204. Furthermore, in Figure 2 In the example, the two resource reservations 204 and 208 have the same periodicity 210, and therefore the data conflict not only occurs at time t1, but also continues at times t2, t3, t4, etc. In view of the recognized problems highlighted above, this disclosure provides circuitry, methods, and non-transitory computer-readable media for resolving such problems.

[0024] In one aspect, the UE (referred to as the evaluation UE) intentionally does not transmit within a scheduled, reserved time period (which may be called a non-continuous scheduled time period), but instead performs channel monitoring on periodically reserved resources. If an SCI of another UE (referred to as the competing UE) is detected during the monitoring function, some form of corrective action is selectively performed, wherein the form of the corrective action is based on the resource reservation period (RRP) and, in some cases, on the data priority of the competing UE. For example, in an aspect where data priority is not a factor or consideration, the form of the RRP-based corrective action may depend on: (1) whether the RRPs of the evaluation UE and the competing UE are the same; (2) whether the RRP of the competing UE is an integer multiple of the RRP of the evaluation UE; or (3) whether the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE. Figures 3A-5 The three conditions highlighted above are shown to help understand how corrective actions differ based on relative RRPs.

[0025] Figure 3A The above condition (1) is illustrated, where the evaluating UE 302 (e.g., UE 1) and the competing UE 304 (e.g., UE 2) have reserved the same time-frequency resources (e.g., resources 306 and 308 are the same). Furthermore, in this example, the reserved resources 306 and 308 have the same periodicity 310, meaning that the RRPs of resources 306 and 308 are the same. Therefore, if no corrective action is taken, a data collision will occur, and neither UE 302 nor UE 304 will detect the data collision. In this example, UE 302 is the evaluating UE and chooses not to transmit in one time period (i.e., t3), but instead performs a channel monitoring operation 312 in that time period. By not transmitting in another scheduled time period (e.g., a non-continuous scheduled time period), the evaluating UE 302 is performing a non-continuous periodic transmission. If a competing UE's SCI is detected and decoded during monitoring time period t3, and the SCI indicates the same time-frequency resource with the same RRP, then UE 302 ceases transmission on the conflicting resource and initiates a reselection procedure, in which UE 302 performs the procedures outlined above. Figure 1 The two-part sensing and selection process discussed is used to schedule other resources. This is in Figure 3A At point 314, it can be seen that the transmission at time t4 is not performed, but a reselection procedure is initiated.

[0026] The exemplary discussion above ignores the issue of data prioritization. That is, in... Figure 3AIn the example of FIG. 3, the evaluation UE 302 interrupts transmission at t4 regardless of whether the evaluation UE 302’s data transmission priority is higher or lower than the competing UE 304’s data transmission priority. In one aspect, the evaluation UE 302 performs the monitoring operation 312 at t3 and decodes the SCI that indicates a conflicting transmission with a competing UE having the same RRP. The evaluation UE 302 then also evaluates the competing UE 304’s data transmission priority, for example by evaluating the competing UE 304’s decoded SCI, and if the evaluation UE 302’s data transmission priority is higher than the competing UE 304’s data transmission priority, the evaluation UE 302 does not interrupt transmission. In this case, despite the conflict, the evaluation UE 302 does not stop transmission due to the higher data priority and instead continues transmission.

[0027] In one aspect, if each UE operates according to the present disclosure, the competing UE 304 sometimes operates as an evaluation UE and in this case will detect a conflict and higher data priority of the other competing UE and in response will interrupt transmission and initiate a reselection procedure.

[0028] Thus, as highlighted above in connection with Figure 3A the present disclosure contemplates a UE or one or more processors in a UE that, when executing instructions, are configured to perform the process 350 of discontinuous periodic communication with another UE, as Figure 3B shown. The process 350 can be a function of an apparatus comprising the functionality of one or more processors in an evaluation UE, can be a method, and / or can be a non-transitory computer-readable medium containing instructions that, when executed by one or more processors, produce the functionality described herein. At 352, the one or more evaluation UE processors are configured to schedule resources for discontinuous periodic transmission. As highlighted above, this scheduling looks similar to the scheduling of UE1 302, which schedules monitoring operations at the scheduled discontinuous time periods (e.g., t3 of FIG. 3) that would otherwise be used for data transmission. This scheduling includes a reservation of periodic time-frequency resources. Further details of this scheduling will be discussed below. Such scheduling details are listed in the SCI and can include periodicity, data priority, and other parameters characterizing the discontinuous periodic communication. Figure 3A

[0029] Still referring to Figure 3B ​One or more UE processors perform monitoring operations according to one of a variety of methods. In one option, monitoring operations are scheduled based on a random selection with a probability (A), which may be pre-configured or may be a function of other criteria such as data priority. On the other hand, the timing of the monitoring process may follow a predefined pattern, making the discontinuous transmission itself periodic. Further details on how and when such monitoring is performed will be discussed in more detail below.

[0030] During the monitoring operation at 354, one or more UE processors monitor the channel for SCIs of other transmitting UEs (i.e., competing UEs) at 356. If no other transmission is detected, or if an SCI is detected but the reserved resources that would conflict with the evaluated UE are not included during decoding (no at 356), then discontinuous periodic transmission continues at 358 until the next scheduled monitoring event. However, if the detected SCI of a competing UE does indeed conflict with the reserved resources of the evaluated UE (yes at 356), then one or more UE processors (i.e., the evaluated UE) perform corrective action at 360.

[0031] In one aspect, the corrective action taken at 360° includes interrupting the periodic transmission of the UE for evaluation and then initiating a reselection process, in which the UE performs the above-mentioned combination Figure 1 The discussion revolves around a two-step sensing and selection process. On the other hand, corrective actions can be selective, where data transmission interruption depends on relative data priority levels or some other criterion. For example, when decoding the SCI of a competing UE, if there is a scheduling resource conflict, but the relative data priorities of the evaluating UE and the competing UE satisfy a predetermined relationship, the evaluating UE will not interrupt transmission despite the detected conflict. For example, if the data priority of the evaluating UE is greater than that of the competing UE, transmission can continue. Alternatively, other criteria can be employed to selectively perform corrective actions at 360 points.

[0032] As mentioned above, the type of corrective action taken by the evaluated UE can differ based on the RRP of the evaluated UE and the competing UE. Option (2) corresponds to the case where the RRP of the competing UE is an integer multiple of that of the evaluated UE (e.g., if the period of the evaluated UE is 100ms, then the period of the competing UE is 100ms × "N", where N is an integer), and Figure 4 As shown in the image. Figure 4 As shown, the competing UE 404 performs periodic transmission 408, which exhibits a period that is an integer multiple of the periodic transmission 406 of the evaluating UE 402. In this example, the integer is 2, therefore the evaluating UE 402 transmits data at twice the frequency of the competing UE 404. Figure 4As can be seen, in this scenario, no conflict will occur for each transmission of the evaluated UE, but a conflict will occur for each transmission of the competing UE. In this example, the conflict occurs at t1, but not at t2. When the evaluated UE 402 interrupts transmission at t3 and instead performs monitoring operation 410, the evaluated UE 402 decodes the SCI of the competing UE 404 and finds that its RRP is an integer multiple of the evaluated UE's RRP (e.g., 100ms compared to 200ms). At this point, the evaluated UE can choose several different options for its corrective action. In one aspect, the evaluated UE interrupts those transmissions only during the conflicting time periods (e.g., 412 and 414) and continues transmission during other non-conflicting time periods. In this case, the evaluated UE 402 does not initiate a reselection procedure but simply skips the transmission on the conflicting resource. Alternatively, the evaluated UE 402 may choose to initiate a reselection procedure. In yet another alternative aspect, after identifying this condition, the evaluated UE 402 may use other criteria to decide whether to skip the conflicting time periods 412, 414 or initiate a reselection. For example, if the data transmission priority of UE 402 is evaluated as "high" (e.g., above a predefined threshold), a reselection can be initiated. Alternatively, if the priority is "low" according to certain predetermined criteria or thresholds, a reselection can be initiated. Any other substantial criteria may be adopted, and this disclosure takes into account these criteria.

[0033] As emphasized above, if condition (3) exists, and the RRP of the evaluated UE is an integer multiple of the RRP of the competing UE, then the situation looks like... Figure 5 .like Figure 5 As shown, both the evaluation UE 502 and the competing UE 504 are performing periodic transmissions, and such scheduling will lead to conflicts due to the occupation of some of the same time-frequency resources. In this case, the evaluation UE 502 will experience a conflict on every transmission, while some partial transmissions of the competing UE 504 will experience conflicts (based on integer multiples of RRP). When the evaluation UE 502 performs a monitoring operation 508 at t3 instead of transmitting data and discovers the problem via the competing UE's SCI, the evaluation UE 502 may choose to interrupt the transmission and instead initiate a reselection procedure. Alternatively, upon detecting the condition, the UE may choose to send a message to the competing UE 504 requesting that the competing UE 504 skip the conflicting resources during the specific period in which the conflict occurs. In yet another alternative, the evaluation UE 502 may consider its data priority and / or the data priority of the competing UE 504 when deciding which corrective action to take in such a situation. For example, if the competing UE's data transmission priority is "high," the evaluation UE 502 may choose to interrupt the transmission and initiate a reselection procedure instead of requesting the competing UE 504 to skip the transmission during the conflicting time period.

[0034] In summary,Figure 6 Changes in corrective action based on three different relationships between the RRP of the evaluating UE and the RRP of the competing UE are shown in the middle. Figure 6 Functions performed by one or more processors of the evaluating UE are shown. As Figure 3B shown, when the query at 356 of whether SCI is detected in the evaluating UE's reserved resources is answered in the affirmative (Yes at 356), corrective action 360 is performed. Figure 6 More details are provided regarding corrective action that can be needed to be taken depending on the RRP relationship between the evaluating UE and the competing UE.

[0035] Initially, one or more processors of the evaluating UE compare its RRP to the RRP of the competing UE via the SCI it decodes. If the RRP is the same (Yes at 662), each transmission by each UE will collide, as Figure 3A shown. In one aspect, at 664, the evaluating UE checks whether its data priority is lower than the data priority of the competing UE. If the RRP is not the same (No at 664), at 666, the evaluating UE can choose not to take further corrective action. This can reflect a situation where the evaluating UE has much higher priority data than the competing UE, and if the competing UE is also performing non-continuous periodic transmissions, it will detect the collision, stop transmission, and perform reselection. If it is determined that the data priority of the evaluating UE is lower than the data priority of the competing UE (Yes at 664), the evaluating UE stops transmission and performs a reselection procedure at 668. Note that the analysis at 664 regarding data priority is optional (shown in dashed lines), and optionally, if the conclusion at 662 is positive (Yes), the evaluating UE can proceed directly to 668, interrupt transmission, and perform reselection.

[0036] Still referring to Figure 6 If the RRP of the evaluating UE and the competing UE is not the same (No at 662), it is determined at 670 whether the RLP of the competing UE is an integer multiple of the evaluating UE. If the RRP is the same (Yes at 670), there is Figure 4 shown situation, and the evaluating UE queries at 672 whether its data priority is higher than the data priority of the competing UE. If the evaluating UE data priority is greater (Yes at 672), no corrective action is taken at 674. That is, although there is an apparent data collision at 412 and 414, as Figure 4The evaluating UE can continue transmission, as shown, but because the data priority of the evaluating UE is sufficiently high according to some predetermined criteria, the evaluating UE can continue transmission. If the competing UE is also performing a non-continuous periodic transmission, the competing UE can detect this condition and because the competing UE has a lower data priority, the competing UE can stop transmission and perform reselection. If the query at 672 is negative (NO at 672), the evaluating UE can select one of two different options. In one case, the evaluating UE can stop transmission with respect to the conflicting resources only, as shown at 676, where the resources for the conflicting time periods 412 and 414 are cancelled, but transmission continues for other evaluating UE resources. In another aspect, if the evaluating UE data priority is not "high" according to some pre-defined criteria, the evaluating UE interrupts all data transmission and initiates a reselection procedure at 678. Again, the data priority analysis at 672 can be optional, as shown by the dashed line. Figure 4

[0037] Still referring to Figure 6 If the query at 670 is negative (NO at 670), another query is made at 680 to determine if the RRP of the evaluating UE is an integer multiple of the RRP of the competing UE. If so (YES at 680), the situation is as shown at 682. Under these conditions, the evaluating UE has two available options, where the evaluating UE stops transmission and performs reselection at 682, or the evaluating UE sends a message to the competing UE skipping those transmissions associated with the conflicting resources at 684. However, if the query at 680 is answered negatively (NO at 680), there is a situation where the RRP of the evaluating UE and the RRP of the competing UE are co-prime. For example, if the RRP of the evaluating UE is 30 ms and the RRP of the competing UE is 100 ms, this situation exists. In another alternative, if the RRP of the competing UE is 0, this means that the competing UE is using the resource only once and is not performing periodic transmission. In this case, no corrective action is taken at 674. Figure 5

[0038] In the example provided in Figures 3A-5 , only a single set of resources or resource blocks are scheduled within each transmission period. In an alternative aspect, multiple non-continuous sets of resources or resource blocks can be scheduled for periodic transmission by a UE. This example is shown in Figure 7A , where a first UE 1 702 and a second UE 2 704 are performing periodic transmission, where multiple non-continuous sets of time-frequency resources or resource blocks are scheduled for transmission within each transmission period. For example, the first UE 1 702 has a first resource block 706 and a second resource block 708, while the second UE 2 has a first resource block 710 and a second resource block 712 scheduled within each transmission period. As Figure 7A ​​As shown, according to the scheduling, the first resource blocks 706 and 710 of UE 702 and UE 704 do not conflict, but the second resource blocks 708 and 712 conflict.

[0039] In one aspect, during the third time period 714, the first UE1 702 does not transmit but performs a monitoring operation 716, in which the first UE listens to the channel of the SCI of other competing UEs. In this case, UE1 702 detects the SCI of UE2 704, decodes it, and determines that the second resource blocks 708 and 712 are in conflict, and therefore must take corrective action. In one aspect, as Figure 7A As shown, the first UE1 702 (i.e., the evaluation UE) stops all further transmissions on all reserved resources, in this case, these reserved resources correspond to the two resource blocks 706 and 708, and performs a reselection procedure. In alternative aspects, such as... Figure 7B As shown, in a similar case where only a portion of the scheduled resources conflict (i.e., resource blocks 708 and 712 conflict, but resource blocks 706 and 710 do not conflict), the evaluation UE 702 interrupts transmission on the conflicting resources only in subsequent transmission cycles, and optionally performs a reselection procedure only for the conflicting resources.

[0040] exist Figures 7A-7B In the example, the evaluation UE 702 performs its monitoring operations on each resource block 706, 708 within the same transmission cycle 714. Alternatively, the evaluation UE can schedule and perform monitoring operations for each resource block in a resource block in different transmission cycles. For example, as Figure 8A As shown, the first UE1 802 transmits in each transmission cycle according to the scheduled resource blocks 806 and 808, while the second UE2 804 transmits in each transmission cycle according to the scheduled resource blocks 810 and 812. Figure 8A As shown, the first resource blocks 806 and 810 of UE 802 and UE 804 do not conflict, while the second resource blocks 808 and 812 of UE 802 and UE 804 do experience a conflict. This is consistent with the monitoring operation performed by UE 702 on two blocks 706 and 708 in the same transmission cycle 714. Figure 7A On the contrary, Figure 8A In this regard, the evaluation UE 802 monitors the first block 806 in the second transmission cycle 814 (815) and the second block 808 in the third transmission cycle 816 (817). As shown, the evaluation UE 802 did not detect any conflicting resources regarding block 806 in the second transmission cycle 814, but detected a conflict regarding block 808 in the third transmission cycle 816. In one aspect, as Figure 8AAs shown, the corrective action taken by the evaluating UE 802 is to interrupt transmission of all resources and perform a reselection procedure on all resources.

[0041] In Figure 8B In another alternative aspect, a similar conflict condition is detected, i.e., a partial conflict is detected. More specifically, a conflict of some resources (i.e., resources for the second resource blocks 808 and 812) but not all resources (i.e., resources for the first resource blocks 806 and 810) is detected. In this aspect, the corrective action taken by the evaluating UE 802 is to interrupt transmission of only the conflicting resources (i.e., resources for the second resource block 808) while continuing transmission of the other non-conflicting resources, as shown. Figure 8B In yet another alternative, the corrective action can be conditioned on other criteria. For example, the priority of the data associated with the reserved resource blocks can be considered. If the priority of the data associated with the conflicting resource blocks is “high” (e.g., it exceeds a predetermined threshold), the conflicting resources are rescheduled, and if the priority is not “high” priority, the evaluating UE 802 simply interrupts transmission on the conflicting resources and maintains transmission on the non-conflicting resources.

[0042] In one aspect, this non-continuous periodic transmission scheme highlighted herein can be selectively enabled or disabled, while in another aspect, the non-continuous periodic transmission scheme can be a fixed solution or can be configured or preconfigured on a resource pool basis. The disclosure contemplates either alternative.

[0043] As discussed above, the problem associated with conflicts in periodic transmission is addressed by the evaluating UE interrupting its periodic transmission and performing a monitoring operation during the time period in which it would have otherwise transmitted in order to determine whether there is a competing UE with a reserved resource that will conflict with the resources of the evaluating UE in the manner discussed herein and illustrated in Figure 3A , Figures 4-5 , Figures 7A-7B and Figures 8A-8B One or more ways in which the scheduling monitoring function is described below to form the non-continuous periodic transmission.

[0044] In one aspect of the disclosure, prior to each transmission on a resource in a given period, the UE determines whether to transmit on the next transmission period and, if it determines to transmit, the UE fills its SCI fields accordingly. In one aspect, the determination of whether to transmit (or monitor) on the next period is based on a random selection of whether to monitor in the next transmission period, with the random selection having a configurable or preconfigured probability (A), or based on criteria such as data priority. For example, if the probability (A) is configured or preconfigured to be 10%, the evaluating UE will select not to transmit while the opportunity to monitor during the next transmission period will be 10%.

[0045] According to an alternative aspect, the probability (A) can depend on various criteria, for example, in one aspect, the probability (A) can depend on data priority. For example, in one aspect, the probability (A) can be increased for high priority data to ensure reliable data transmission, while it can be decreased for low priority data. Alternatively, the probability (A) can be decreased for high priority data to enable more continuous data transmission, while it can be increased for low priority data to avoid collision with high priority data in competing UEs.

[0046] According to another alternative aspect, the probability (A) can depend on collision history. If a relatively high number of collisions is detected in a recent predefined time period (according to some predetermined threshold or criterion), the probability (A) can be increased to monitor more frequently, and if the recent history does not show collisions or shows infrequent collisions, the probability (A) can be decreased. In other aspects, multiple factors or criteria can be considered collectively in forming or otherwise configuring the probability (A).

[0047] Further, for a non-continuous number of resources reserved in each transmission period, such as Figure 8A As shown, the probability can be applied independently to each of the scheduled resources in the time period.

[0048] In another aspect, the monitoring by the UE can follow a predetermined pattern or periodicity. For example, in one aspect, the periodic transmission is non-continuous since monitoring is performed every "B" time periods. The value B can be (pre-)configured, or can be randomly selected from a set of pre-configured periods. For example, the set can be a set of prime numbers, such as {2, 3, 5, 7, 11}, which can avoid consecutive identical non-continuous resources from different UEs. In another aspect, the selection of the value B can depend on data priority. For example, for high priority data, the value B can be selected to be a lower value so that monitoring is performed more frequently to ensure more reliable transmission, while for low priority data, B can be set to a larger value. In another aspect, for high priority data, B can be higher to ensure more continuous transmission of such data. Further, in one aspect, once the periodicity B is selected, the starting point also needs to be determined. In one aspect, the starting period of the non-continuous resource time periods can be randomly selected between 0 and B-1. Alternatively, the starting point can be configured or pre-configured, or based on other criteria.

[0049] The above discussion discloses determining a frequency of making otherwise periodic transmissions non-consecutive by scheduling monitoring operations. The manner in which such non-consecutive transmissions are signaled can be performed in a variety of different ways. In one aspect, if the evaluating UE determines a non-consecutive transmission in the next time period, the evaluating UE changes the RRP (i.e., resource reservation period) field of the SCI to skip the next transmission time period. In one aspect, if the current RRP is set to 100 ms, the evaluating UE sets the RRP in the SCI associated with the PSSCH one period before the non-consecutive transmission to 200 ms (twice the periodicity). In another example, if the RRP is set to 400 ms, the RRP of the SCI one period before the non-consecutive transmission is set to 800 ms to double the periodicity and effectively “skip” that particular transmission period so that it can be utilized to monitor the channel. In Figure 9 One example of this feature is shown in the middle where the SCI field indicates one period for the normal periodic transmission and then indicates a “2x period” on the period before the monitoring operation 914 to indicate that the transmission on the scheduled resource skips to the “next” transmission period after the non-consecutive (monitoring) time period.

[0050] In another aspect, an additional bit can be employed in the SCI field to indicate a non-consecutive transmission in the next transmission period. For example, if the additional bit is set to “0”, the resources in the next transmission period are reserved and the periodic transmission continues. For example, if the additional bit is set to “1”, the resources in the next transmission period are not reserved and monitoring can be performed and the resources will be reserved for transmission in the period after the monitoring period.

[0051] In the various aspects discussed above, a non-consecutive periodic transmission scheme is disclosed in which the evaluating UE stops transmission during the non-consecutive time period to monitor the channel for potential collisions. In another aspect, rather than discontinuing the periodic transmission, the transmitting UE operates as the evaluating UE and performs self-detection of the collision operation by evaluating the feedback from one or more receiving UEs when HARQ feedback is enabled. Alternatively, the transmitting UE operates as the evaluating UE by looking for HARQ feedback on the sidelink feedback channel (PSFCH) resources corresponding to PSCCH and PSSCH transmissions made by other transmitting UEs to inferentially determine a collision when HARQ feedback is disabled.

[0052] In one aspect, self-detection of a collision can be performed by the transmitting UE that performs the periodic transmission. For example, in a sidelink unicast or groupcast transmission in which HARQ feedback is enabled, the transmitting UE can evaluate the received feedback by multiple evaluating feedback messages and calculate the percentage of negative acknowledgements (NACKs) in such messages. If the percentage of such NACKs exceeds a predetermined threshold, a collision is determined to exist with respect to the scheduled resources and a competing UE.

[0053] As is known, unicast transmission is a one-to-one communication in which the transmitting UE is transmitting periodic transmissions to a single, specific receiving UE. In response to unicast transmissions, when HARQ feedback is enabled, the transmitting UE receives a response from the receiving UE to the sidelink data packet. Generally, HARQ-ACK refers to a response indicating whether the sidelink data packet was successfully received. Available HARQ-ACK responses include, among others, positive acknowledgement (ACK), negative acknowledgement (NACK), and DTX. Since only ACK indicates successful reception of the transmitted data, for the purposes of this disclosure, NACK or DTX are considered as “NACK” and thus represent an unsuccessful transmission, possibly due to a collision. Thus, in periodic transmissions, the reception of NNACK or DTX is considered as “failure” for a successive transmission of data, while ACK is considered as “success”. If the percentage of “failures” is greater than a threshold, the transmitting UE concludes that there is a collision on the scheduled periodic resources. In such cases, a corrective action is performed, e.g., interrupting the periodic transmissions and initiating a reselection procedure.

[0054] In an aspect, the threshold for concluding that a collision has occurred is pre-configured or configured. In another aspect, the threshold can be based on a data quality of service (QoS) parameter or data priority level. For example, if the QoS or data priority is high, the threshold can be lower to trigger a reselection operation if there is a small chance of a collision.

[0055] Reference Figure 10 A UE functionality 1000 is provided for self-detecting collisions in a periodic communication environment employing, for example, autonomous selection. Such UE is a transmitting UE which also operates as an evaluating UE to detect collisions with contending UEs. Figure 10 There can also correspond a method of performing self-detection of collisions in the above-described environment using one or more processors, and possibly also a non-transitory computer readable medium containing instructions that, when executed by one or more processors, perform the methods described herein.

[0056] In an aspect, the functionality 1000 starts at 1002 with a query whether HARQ feedback is enabled in the UE. Since this criterion allows for selectively enabling HARQ feedback, the functionality 1000 provides two different options. If HARQ feedback is enabled (Yes at 1002), the transmitting UE will receive ACK / NACK type feedback in response to the periodic transmissions.

[0057] Upon learning that HARQ feedback is enabled, at 1004, the transmitting UE receives resources for periodic communications and utilizes one or more feedback-based collision detection parameters to schedule such resources. Non-limiting examples of such feedback-based collision detection parameters can be as follows. One parameter can be the total number of transmissions 1006 in a periodic transmission. For example, if the transmitting UE is associated with a vehicle, the transmitting UE can periodically transmit vehicle speed a total of 100 times or 500 times before needing to reschedule. This information can also include the period that determines the frequency of such data transmissions. Another feedback collision detection parameter can be the number of data collection transmissions 1008 used to collect NACK statistics. In one example, if the total number of periodic transmissions is 100, the number of transmissions to be used or evaluated to collect NACK statistics can be 10. Thus, the UE will evaluate the first 10 HARQ feedbacks regarding 100 transmissions and base its decision on the 10 HARQ feedbacks.

[0058] Still referring to Figure 10 , another feedback collision detection parameter can include a data collection format 1010. For example, in the example provided, the analysis of potential collisions can be based on 10 / 100 transmissions. In one data collection format 1010, only the first 10 HARQ feedbacks are considered. In another aspect, the 10 HARQ feedbacks are evaluated in every subsequent set throughout the transmissions, such that transmissions 1-10 are evaluated, then 11-20 are evaluated, then 21-30 are evaluated, and so on. In another aspect, the data collection format can be a sliding window, where a segment of HARQ feedback information 1-10 is evaluated, then 5-15, then 10-20, then 15-25, and so on. The data collection format 1010 allows for flexible customization of the manner in which the self-collision data analysis will be performed.

[0059] Another feedback collision detection parameter is a threshold 1012. For example, when collecting NACK statistics, the percentage of NACKs received can be compared to a threshold, and if the percentage of NACKs exceeds the threshold, a conclusion is drawn that there is a collision on the scheduled resources. For example, if 10 out of 100 transmissions are evaluated for their HARQ feedback responses, and 2 of the 10 HARQ feedback responses are NACKs, the percentage of NACKs is 20%. If the threshold 1012 is 30%, a conclusion is drawn that there is no collision, and if the threshold is 10%, a conclusion is drawn that there is a collision with a competing UE on the reserved resources.

[0060] Referring back to Figure 10Once the reserved resources are scheduled with the feedback-based collision detection parameters at 1004, periodic transmissions are initiated and occur at 1014 by the transmitting UE. As the periodic transmissions occur at 1014, NACK statistics are collected at the transmitting UE via HARQ feedback at 1016, and such NACK statistics are collected in accordance with one or more of the feedback-based collision detection parameters. Functionality 1000 continues to 1018, where the NACK statistics are converted to, for example, a percentage, and compared to the threshold 1012. If the threshold is not exceeded (NO at 1018), a conclusion can be drawn that there is no collision currently with the reserved resources, and if the periodic transmissions are still continuing (NO at 1020), additional NACK statistics can be collected in accordance with the data collection format 1010. If the periodic transmissions have completed (YES at 1020), no corrective action is needed because no resource collision was detected.

[0061] Referring back to Figure 10 Action 1018 of FIG. 1, if the calculated NACK percentage does exceed the threshold (YES at 1018), a conclusion is drawn that a collision has occurred, and corrective action is selectively performed at 1024. In one aspect, the corrective action is to interrupt the periodic transmissions and initiate a reselection procedure. In one aspect, the corrective action can be selected based on various other criteria.

[0062] Referring back to Figure 10 Query 1002 of FIG. 1, if HARQ feedback is not enabled (NO at 1002), the transmitting UE will not receive HARQ feedback information. However, if other contending UEs are transmitting and employing HARQ feedback, at 1030, the evaluating UE can detect such information on the feedback channel (e.g., the Physical Sidelink Feedback Channel (PSFCH)). If HARQ feedback is detected during monitoring of the PSFCH (YES at 1032), it can be inferred that the periodic transmissions by the evaluating UE are colliding with transmissions by the contending UEs, and corrective action is performed at 1024. In one example, the corrective action is to interrupt the periodic transmissions and initiate a reselection procedure. If, for example, no HARQ feedback is detected on the PSFCH (NO at 1032), a conclusion is drawn that there is no collision, and no corrective action is taken at 1034. For example, the periodic transmissions by the evaluating UE continue.

[0063] In the descriptions above, descriptions are made in connection with several flowcharts outlining example methods. In this specification and the appended claims, the term “determining” used in reference to describing steps or functions of a method is broadly interpreted to cover, for example, receiving and parsing a communication encoding an entity or a value of an entity. “Determining” is to be interpreted to cover accessing and reading a memory storing an entity or a value for an entity (e.g., a look-up table, a register, a device memory, a remote memory, etc.). “Determining” is to be interpreted to cover calculating or deriving an entity or a value for an entity based on other quantities or entities. “Determining” is to be interpreted to cover any manner of inferring or identifying an entity or a value for an entity.

[0064] As used herein, the term “identifying” when used in reference to some entity or a value of an entity is to be broadly interpreted to cover any manner of determining an entity or a value for an entity. For example, the term “identifying” is to be interpreted to cover, for example, receiving and parsing a communication encoding an entity or a value of an entity. The term “identifying” is to be interpreted to cover accessing and reading a memory storing an entity or a value for an entity (e.g., a device queue, a look-up table, a register, a device memory, a remote memory, etc.).

[0065] As used herein, the term “selecting” when used in reference to some entity or a value of an entity is to be broadly interpreted to cover any manner of determining an entity or a value for an entity from a plurality or a range of possible selections. For example, the term “selecting” is to be interpreted to cover accessing and reading a memory storing an entity or a value for an entity (e.g., a look-up table, a register, a device memory, a remote memory, etc.) and returning one entity or entity value from those stored. The term “selecting” is to be interpreted to apply one or more constraints or rules to a set of input parameters to determine an appropriate entity or entity value. The term “selecting” is to be interpreted to broadly cover any manner of selecting an entity based on one or more parameters or conditions.

[0066] As used herein, the term “deriving” when used in reference to some entity or a value of an entity is to be broadly interpreted. “Deriving” is to be interpreted to cover accessing and reading a memory storing some initial value or base value (e.g., a look-up table, a register, a device memory, a remote memory, etc.) and performing processing and / or logical / mathematical operations on one or more values to generate a derived entity or a value for an entity. “Deriving” is to be interpreted to cover calculating or deriving an entity or a value for an entity based on other quantities or entities. “Deriving” is to be interpreted to cover any manner of inferring or identifying an entity or a value for an entity.

[0067] As described herein, for discussion purposes, each vehicle employing V2X communication principles will be described as a UE (i.e., user equipment). Figure 11A non-limiting example of a platform 1100 (or “device 1100”) in accordance with various aspects that can constitute circuitry forming a UE is shown. In aspects, computer platform 1100 can be suitable to use as a UE and / or any of the other elements / devices discussed herein. Platform 1100 can include any combinations of the components shown in the example. The components of platform 1100 can be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof adapted in the computer platform 1100, or as components otherwise incorporated within a chassis of a larger system. Figure 11 The depiction of platform 1100 as an example is not meant to limit the scope of the application. Other platforms that have fewer components, different components, or different arrangements of the components can also be used, and are within the scope of the application. Moreover, the platform 1100 can be a device that is separate from a UE, such as a desktop computer, a computer server, or a computer workstation, among others. The platform 1100 can also be a device that is integrated within a UE, such as an application-specific integrated circuit (ASIC) or system on a chip (SoC).

[0068] The application circuitry 1105 includes circuitry such as, but not limited to, one or more processors (or processor cores), cache memory, and one or more of LDOs, interrupt controllers, serial interfaces such as SPI, I2C or general purpose serial interface modules, RTC, timers, general purpose I / O, memory card controllers such as SD MMC or similar, USB interfaces, MIPI interfaces, and JTAG test access ports. The processors (or cores) of the application circuitry 1105 can be coupled with or include memory / storage elements and can be configured to

[0069] For example, the processors of the application circuitry 1105 can include general- purpose or special-purpose processors such as: ARM-based processors available from Inc., Cupertino, CA (e.g., Apple A13 Bionic) or any other such processors. The processors of the application circuitry 1105 can also be one or more of: Advanced Micro Devices (AMD) Ryzen® or Athlon® processors; Intel Pentium®, Core®, Celeron®, and Atom® processors; and / or the like. The processors of the application circuitry 1105 can be a system on a chip, such as a system on a chip that has a plurality of Technologies, Inc. Snapdragon® processors; Texas Instruments, Inc. Davinci® processors; and / or the like. In some embodiments, the processors of the application circuitry 1105 can be a part of a SoC, along with other components such as storage media, graphics processing units, image signal processors, and so forth. TM processors; Texas Instruments, Inc. Davinci® processors; and / or the like. In some embodiments, the processors of the application circuitry 1105 can be a part of a SoC, along with other components such as storage media, graphics processing units, image signal processors, and so forth. Open Multimedia Applications Platform (OMAP) TM Processor; MIPS-based designs from MIPS Technologies, Inc., such as MIPS Warrior M-class, Warrior I-class, and Warrior P-class processors; ARM-based designs licensed from ARM Holdings, Ltd., such as the ARM Cortex-A, Cortex-R, and Cortex-M family of processors; etc. In some implementations, the application circuitry 1105 can be a part of a system on a chip (SoC) where the application circuitry 1105 and other system components are formed into a single integrated circuit, or a single package.

[0070] The baseband circuitry 1110 can be implemented, for example, as a solder-down substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board, or a multi-chip module including two or more integrated circuits.

[0071] The platform 1100 can also include interface circuitry (not shown) for connecting external devices with the platform 1100. The external devices connected to the platform 1100 via the interface circuitry include sensor circuitry 1121 and electro-mechanical components (EMCs) 1122, as well as removable memory devices coupled to removable memory circuitry 1123.

[0072] The battery 1130 can power the platform 1100, and can be rechargeable or non-rechargeable. The battery 1130 can be a lithium-ion battery, a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, the battery 1130 can be a typical lead-acid automotive battery, which can be recharged. In some implementations, the battery 1130 can have a battery management system (BMS) that balances, charges, discharges, monitors, and / or maintains the battery 1130. In some implementations, the BMS can be part of the platform 1100, part of the battery 1130, or a separate device coupled to the platform 1100 and / or the battery 1130.

[0073] While the method is illustrated and described above as a series of acts or events, it will be appreciated that not all of the illustrated acts or events are necessarily present in every instance, and / or that the order of the acts or events can be changed, and / or that some of the acts or events can be performed concurrently, and / or that some of the acts or events can be performed at different times. Further, some of the acts or events can not be necessary in every instance. Additionally, some of the acts or events can be performed in one or more separate acts or phases. In some embodiments, the methods illustrated above can be implemented using instructions stored in a memory and executed by a processor. Many other embodiments and variations are possible based on the scope of the disclosure as claimed.

[0074] Example

[0075] Example 1 is an evaluation user equipment (UE), the evaluation UE comprising: a memory; and one or more processors communicatively coupled to the memory. The one or more processors are configured to: schedule resources for a non-contiguous periodic transmission, the non-contiguous periodic transmission having scheduled non-contiguous time periods in which scheduled resources are not transmitted; and perform a monitoring operation in the scheduled non-contiguous time periods, the monitoring operation comprising monitoring for a collision of the scheduled resources of the evaluation UE with scheduled resources of a competing UE. The one or more processors are further configured to selectively perform a corrective action when a collision of the scheduled resources of the evaluation UE with the scheduled resources of the competing UE is detected during the monitoring operation.

[0076] Example 2 includes the subject matter of Example 1, wherein when scheduling resources for a non-contiguous periodic transmission, the one or more processors are configured to determine whether the evaluation UE will transmit on a next transmission time period based on a random selection, the random selection having a probability that the next transmission time period is a non-contiguous time period and thus not scheduled for data transmission on the next transmission time period.

[0077] Example 3 includes the subject matter of Example 2, wherein the probability is a preconfigured probability value.

[0078] Example 4 includes the subject matter of Claim 2, wherein the probability depends on a data priority associated with the scheduled resources.

[0079] Example 5 includes the subject matter of Example 4, wherein if the data priority is greater than a predefined threshold, the probability is a high probability value that is greater than a nominal probability value.

[0080] Example 6 includes the subject matter of Example 1, wherein when scheduling resources for a non-contiguous periodic transmission, the one or more processors are configured to determine whether the evaluation UE will transmit on a next transmission time period based on a predefined periodicity of the scheduled non-contiguous time periods in which scheduled resources are not transmitted.

[0081] Example 7 includes the subject matter of Example 6, wherein the predefined periodicity is randomly selected from a set of preconfigured periods.

[0082] Example 8 includes the subject matter of Example 6, wherein the predefined periodicity depends on a data priority associated with the scheduled resources.

[0083] Example 9 includes the subject matter of Example 1, wherein when scheduling resources for non-consecutive periodic transmissions, the one or more processors are configured to: determine that a next period will be a non-consecutive transmission period; and set a resource reservation period (RRP) field of a sidelink control information (SCI) message of the evaluating UE to a new value that doubles a periodicity of the previous RRP field value for the evaluating UE.

[0084] Example 10 includes the subject matter of Example 1, wherein when scheduling resources for non-consecutive periodic transmissions, the one or more processors are configured to: determine that a next period will be a non-consecutive transmission period; and set a bit in a sidelink control information (SCI) message field to a predetermined value that indicates that scheduled resources in the next transmission period are not reserved for data transmissions, but the scheduled resources in a transmission period after the next transmission period are reserved for data transmissions.

[0085] Example 11 includes the subject matter of Example 1, wherein when performing the monitoring operation at the scheduled non-consecutive time periods, the one or more processors are configured to: evaluate one or more relevant frequency channels of sidelink control information (SCI) messages for one or more contending UEs; and for each SCI message detected in the relevant frequency channels, determine whether any scheduled resources of the one or more contending UEs conflict with the scheduled resources of the evaluating UE.

[0086] Example 12 includes the subject matter of Example 1, wherein when selectively performing the corrective action when a conflict is detected, the one or more processors are configured to: evaluate whether a resource reservation period (RRP) of a contending UE is the same as the evaluating RRP’s RRP; and selectively stop non-consecutive periodic transmissions of the evaluating UE on the scheduled resources and perform a reselection operation to reschedule resources for non-consecutive periodic transmissions on different reserved resources.

[0087] Example 13 includes the subject matter of Example 12, wherein the one or more processors are further configured to: determine whether a data priority of the evaluating UE is greater than a data priority of the contending UE; and if the data priority of the evaluating UE is greater than the data priority of the contending UE, then not take a corrective action.

[0088] Example 14 includes the subject matter of Example 1, wherein when selectively performing the corrective action upon detecting a collision, the one or more processors are configured to: evaluate whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and selectively stop periodic transmissions of the evaluating UE only on those reserved resources that collide with transmissions of the contending UE when the RRP of the contending UE is an integer multiple of the RRP of the evaluating UE.

[0089] Example 15 includes the subject matter of Example 14, wherein the one or more processors are configured to: determine whether a data priority of the evaluating UE is greater than a data priority of the contending UE; and if the data priority of the evaluating UE is greater than the data priority of the contending UE, not take a corrective action.

[0090] Example 16 includes the subject matter of Example 1, wherein when selectively performing the corrective action upon detecting a collision, the one or more processors are configured to: evaluate whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and send, from the evaluating UE to the contending UE, a message to skip periodic transmissions on scheduled resources that collide with the scheduled resources of the evaluating UE when the RRP of the evaluating UE is an integer multiple of the RRP of the contending UE.

[0091] Example 17 includes the subject matter of Example 1, wherein when selectively performing the corrective action upon detecting a collision, the one or more processors are configured to: evaluate whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and stop discontinuous periodic transmissions and perform a reselection operation to reschedule resources for discontinuous periodic transmissions on different reserved resources.

[0092] Example 18 relates to a method of performing UE autonomous selection in an evaluating user equipment (UE). The method includes scheduling, using the one or more processors, resources for discontinuous periodic transmissions, the discontinuous periodic transmissions having a scheduled discontinuous time period in which scheduled resources are not transmitted; and performing, using the one or more processors, a monitoring operation during the scheduled discontinuous time period, the monitoring operation including monitoring for collisions of scheduled resources of the evaluating UE with scheduled resources of a contending UE. The method further includes selectively performing, using the one or more processors, a corrective action when a collision of the scheduled resources of the evaluating UE with the scheduled resources of the contending UE is detected during the monitoring operation.

[0093] Example 19 includes the subject matter of Example 18, wherein when scheduling resources for non-consecutive periodic transmissions, the method includes determining whether the evaluating UE will transmit on a next transmission time period based on a random selection having a probability that the next transmission time period is a non-consecutive time period and thus not scheduled for data transmission on the next transmission time period.

[0094] Example 20 includes the subject matter of Example 19, wherein the probability is a preconfigured probability value.

[0095] Example 21 includes the subject matter of Example 19, wherein the probability depends on a data priority associated with the scheduled resources.

[0096] Example 22 includes the subject matter of Example 21, wherein if the data priority is greater than a predefined threshold, the probability is a high probability value that is greater than a nominal probability value.

[0097] Example 23 includes the subject matter of Example 18, wherein when scheduling resources for non-consecutive periodic transmissions, the method includes determining whether the evaluating UE will transmit on a next transmission time period based on a predefined periodicity of the scheduled non-consecutive time periods in which the scheduled resources are not transmitted.

[0098] Example 24 includes the subject matter of Example 23, wherein the predefined periodicity is randomly selected from a set of preconfigured periodicities.

[0099] Example 25 includes the subject matter of Example 23, wherein the predefined periodicity depends on a data priority associated with the scheduled resources.

[0100] Example 26 includes the subject matter of Example 18, wherein when scheduling resources for non-consecutive periodic transmissions, the method includes determining, using the one or more processors, that a next period will be a non-consecutive transmission period, and setting, using the one or more processors, a resource reservation period (RRP) field of a sidelink control information (SCI) message of the evaluating UE to a new value that doubles a periodicity of the previous RRP field value of the evaluating UE with respect to transmissions.

[0101] Example 27 includes the subject matter of Example 18, wherein when scheduling resources for non-consecutive periodic transmissions, the method includes determining that a next period will be a non-consecutive transmission period, and setting a bit in a sidelink control information (SCI) message field to a predetermined value that indicates that the scheduled resources in the next transmission period are not reserved for data transmission, but the scheduled resources in a transmission period after the next transmission period are reserved for data transmission.

[0102] Example 28 includes the subject matter of Example 18, wherein when the monitoring operation is performed at the scheduled non-consecutive time periods, the method includes: evaluating one or more relevant frequency channels for sidelink control information (SCI) messages of one or more contending UEs; and for each SCI message detected in the relevant frequency channels, determining whether any scheduled resources of the one or more contending UEs conflict with the scheduled resources of the evaluating UE.

[0103] Example 29 includes the subject matter of Example 18, wherein when the corrective action is selectively performed upon detecting a conflict, the method includes: evaluating whether a resource reservation period (RRP) of a contending UE is the same as an RRP of the evaluating RRP; and selectively stopping the evaluating UE from non-consecutive periodic transmissions on the scheduled resources and performing a reselection operation to reschedule resources for non-consecutive periodic transmissions on different reserved resources.

[0104] Example 30 includes the subject matter of Example 29, and the subject matter further includes: determining whether a data priority of the evaluating UE is greater than a data priority of the contending UE; and if the data priority of the evaluating UE is greater than the data priority of the contending UE, then not taking a corrective action.

[0105] Example 31 includes the subject matter of Example 18, wherein when the corrective action is selectively performed upon detecting a conflict, the method includes: evaluating whether a resource reservation period (RRP) of a contending UE is an integer multiple of the RRP of the evaluating UE; and when the RRP of the contending UE is an integer multiple of the RRP of the evaluating UE, selectively stopping the evaluating UE from periodic transmissions on only those reserved resources that conflict with transmissions of the contending UE.

[0106] Example 32 includes the subject matter of Example 31, and the subject matter further includes: determining whether a data priority of the evaluating UE is greater than a data priority of the contending UE; and if the data priority of the evaluating UE is greater than the data priority of the contending UE, then not taking a corrective action.

[0107] Example 33 includes the subject matter of Example 18, wherein when the corrective action is selectively performed upon detecting a conflict, the method further includes: evaluating whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and when the RRP of the evaluating UE is an integer multiple of the RRP of the contending UE, sending a message from the evaluating UE to the contending UE to skip periodic transmissions on scheduled resources that conflict with the scheduled resources of the evaluating UE.

[0108] Example 34 includes the subject matter of Example 18, wherein when the corrective action is selectively performed upon detecting a collision, the method further comprises: evaluating whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and discontinuing discontinuous periodic transmissions and performing a reselection operation to reschedule resources for discontinuous periodic transmissions on different reserved resources.

[0109] Example 35 relates to a non-transitory computer-readable medium containing instructions, where such instructions, when executed by one or more processors, are configured to perform a method of performing UE autonomous selection in an evaluating user equipment (UE). The method includes scheduling resources for discontinuous periodic transmissions using the one or more processors, the discontinuous periodic transmissions having a scheduled discontinuous time period in which scheduled resources are not transmitted; performing a monitoring operation using the one or more processors during the scheduled discontinuous time period, the monitoring operation comprising monitoring for a collision of the evaluating UE’s scheduled resources with a contending UE’s scheduled resources; and selectively performing a corrective action using the one or more processors when a collision of the evaluating UE’s scheduled resources with the contending UE’s scheduled resources is detected during the monitoring operation.

[0110] Example 36 includes the subject matter of Example 35, wherein when scheduling resources for discontinuous periodic transmissions, the method comprises determining whether the evaluating UE will transmit on a next transmission time period based on a random selection, the random selection having a probability that the next transmission time period is a discontinuous time period and is therefore not scheduled for data transmission on the next transmission time period.

[0111] Example 37 includes the subject matter of Example 36, wherein the probability is a preconfigured probability value.

[0112] Example 38 includes the subject matter of Example 36, wherein the probability depends on a data priority associated with the scheduled resources.

[0113] Example 39 includes the subject matter of Example 38, wherein if the data priority is greater than a predefined threshold, the probability is a high probability value that is greater than a nominal probability value.

[0114] Example 40 includes the subject matter of Example 35, wherein when scheduling resources for discontinuous periodic transmissions, the method comprises determining whether the evaluating UE will transmit on a next transmission time period based on a predefined periodicity of the scheduled discontinuous time period in which scheduled resources are not transmitted.

[0115] Example 41 includes the subject matter of Example 40, wherein the predefined periodicity is randomly selected from a set of preconfigured periodicities.

[0116] Example 42 includes the subject matter of Example 40, wherein the predefined periodicity depends on a data priority associated with the scheduled resources.

[0117] Example 43 includes the subject matter of Example 35, wherein when scheduling resources for non-consecutive periodic transmissions, the method comprises: determining, using the one or more processors, that a next period will be a non-consecutive transmission period; and setting, using the one or more processors, a resource reservation period (RRP) field of a sidelink control information (SCI) message of the evaluating UE to a new value that doubles a periodicity of the previous RRP field value with respect to the evaluating UE.

[0118] Example 44 includes the subject matter of Example 35, wherein when scheduling resources for non-consecutive periodic transmissions, the method comprises: determining that a next period will be a non-consecutive transmission period; and setting a bit in a sidelink control information (SCI) message field to a predetermined value that indicates that the scheduled resources in the next transmission period are not reserved for data transmissions, but the scheduled resources in a transmission period after the next transmission period are reserved for data transmissions.

[0119] Example 45 includes the subject matter of Example 35, wherein when performing the monitoring operation in the scheduled non-consecutive time periods, the method comprises: evaluating one or more relevant frequency channels for sidelink control information (SCI) messages of one or more contending UEs; and for each SCI message detected in the relevant frequency channels, determining whether any scheduled resources of the one or more contending UEs conflict with the scheduled resources of the evaluating UE.

[0120] Example 46 includes the subject matter of Example 35, wherein when selectively performing the corrective action when a conflict is detected, the method comprises: evaluating whether a resource reservation period (RRP) of a contending UE is the same as the evaluating RRP’s RRP; and selectively stopping non-consecutive periodic transmissions of the evaluating UE on the scheduled resources and performing a reselection operation to reschedule resources for non-consecutive periodic transmissions on different reserved resources.

[0121] Example 47 includes the subject matter of Example 46, and the subject matter further comprises: determining whether a data priority of the evaluating UE is greater than a data priority of the contending UE; and if the data priority of the evaluating UE is greater than the data priority of the contending UE, then not taking a corrective action.

[0122] Example 48 includes the subject matter of Example 35, wherein when selectively performing the corrective action upon detecting a collision, the method comprises: evaluating whether a resource reservation period (RRP) of a contending UE is an integer multiple of the RRP of the evaluating UE; and selectively stopping periodic transmissions of the evaluating UE only on those reserved resources that collide with transmissions of the contending UE when the RRP of the contending UE is an integer multiple of the RRP of the evaluating UE.

[0123] Example 49 includes the subject matter of Example 48, and the subject matter further comprises: determining whether a data priority of the evaluating UE is greater than a data priority of the contending UE; and not taking a corrective action if the data priority of the evaluating UE is greater than the data priority of the contending UE.

[0124] Example 50 includes the subject matter of Example 35, wherein when selectively performing the corrective action upon detecting a collision, the method further comprises: evaluating whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and sending a message from the evaluating UE to the contending UE to skip periodic transmissions on scheduled resources that collide with the scheduled resources of the evaluating UE when the RRP of the evaluating UE is an integer multiple of the RRP of the contending UE.

[0125] Example 51 includes the subject matter of Example 35, wherein when selectively performing the corrective action upon detecting a collision, the method further comprises: evaluating whether a resource reservation period (RRP) of the evaluating UE is an integer multiple of the RRP of the contending UE; and stopping discontinuous periodic transmissions and performing a reselection operation to reschedule resources for discontinuous periodic transmissions on different reserved resources.

[0126] The term“coupled” is used throughout the specification. This term can cover a connection, a communication, or a signal path that enables a functional relationship consistent with the description of the present disclosure. For example, if device A generates a signal to control device B to perform an action, then in a first example, device A is coupled to device B, or in a second example, device A is coupled to device B through intermediate component C if component C does not substantially alter the functional relationship between device A and device B such that device B is controlled by device A via the control signal generated by device A.

[0127] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a way to minimize risk of unintentional or unauthorized access or use, and privacy rights of users should be clearly explained before collecting such information.

Claims

1. An evaluating user equipment (UE), the evaluating UE comprising: a memory; one or more processors communicatively coupled to the memory and configured to cause the evaluating UE to: schedule periodic resources for a non-contiguous periodic transmission, the periodic resources comprising a plurality of transmission time periods for data transmission and a non-contiguous time period in which non-contiguous resources of the periodic resources are used to monitor the periodic resources for collision with scheduled resources of a contending UE, wherein the non-contiguous resources are selected based on a probability value; when the collision is detected, perform a corrective action; wherein the probability value is a low probability value less than a nominal probability value if a priority of the data transmission is greater than a predefined threshold.

2. The evaluating UE of claim 1, wherein a plurality of resources are scheduled for each period of the non-contiguous periodic transmission, and the probability value is applied independently to each resource of the plurality of resources.

3. The evaluating UE of claim 1, wherein the probability value is a preconfigured or configured probability value.

4. The evaluating UE of claim 1, wherein a resource reservation period (RRP) of the evaluating UE is an integer multiple of a RRP of the contending UE, and the collision is detected, transmit a message to the contending UE to skip data transmission on the scheduled resources of the contending UE that collide with the periodic resources.

5. The evaluating UE of claim 1, wherein when scheduling the periodic resources, the one or more processors are configured to: in response to determining that a next period will be the non-contiguous time period, set a resource reservation period (RRP) field of a sidelink control information (SCI) message of the evaluating UE to a new value that doubles a previous RRP field value of the evaluating UE.

6. The evaluating UE of claim 1, wherein when scheduling the periodic resources, the one or more processors are configured to: set a bit in a sidelink control information (SCI) message to a predetermined value to indicate that a next period is the non-contiguous time period.

7. The evaluating UE of claim 1, wherein when performing the corrective action, the one or more processors are configured to: evaluate whether a resource reservation period (RRP) of the contending UE is an integer multiple of the RRP of the evaluating UE; and when the RRP of the contending UE is an integer multiple of the RRP of the evaluating UE, stop the non-contiguous periodic transmission on only resources of the periodic resources in which the collision occurs.

8. A method of performing UE autonomous selection in an evaluating user equipment (UE) within a vehicle-to-everything (V2X) communication environment, the method comprising: scheduling periodic resources for a non-contiguous periodic transmission, the periodic resources comprising a plurality of transmission time periods for data transmission and a non-contiguous time period in which non-contiguous resources of the periodic resources are used to monitor the periodic resources for collision with scheduled resources of a contending UE, wherein the non-contiguous resources are selected based on a probability value; when the collision is detected, performing a corrective action; when the conflict is detected, performing a corrective action; wherein the probability value is a low probability value less than a nominal probability value if a priority of the data transmission is greater than a predefined threshold.

9. The method of claim 8, wherein multiple resources are scheduled for each period of the non-contiguous periodic transmission, and the probability value is applied independently to each of the multiple resources.

10. The method of claim 8, wherein the probability value is a preconfigured or configured probability value.

11. The method of claim 8, wherein in response to the evaluating UE’s resource reservation period (RRP) is an integer multiple of the RRP of the contending UE, and the conflict is detected, sending a message to the contending UE to skip data transmission on the contending UE’s scheduled resources that conflict with the periodic resources.

12. The method of claim 8, wherein when scheduling the periodic resources, the method comprises: in response to determining that a next period will be the non-contiguous time period, setting a resource reservation period (RRP) field of a sidelink control information (SCI) message of the evaluating UE to a new value that doubles a previous RRP field value of the evaluating UE.

13. The method of claim 8, wherein when scheduling the periodic resources, the method comprises: setting a bit in a sidelink control information (SCI) message to a predetermined value to indicate that a next period is the non-contiguous time period.

14. The method of claim 8, wherein when performing the corrective action, the method comprises: evaluating whether a resource reservation period (RRP) of the contending UE is an integer multiple of the RRP of the evaluating UE; and when the RRP of the contending UE is an integer multiple of the RRP of the evaluating UE, stopping the non-contiguous periodic transmission on resources where the conflict occurs only in the periodic resources.

15. A non-transitory computer-readable medium containing instructions, wherein such instructions, when executed by one or more processors, are configured to perform a method of performing UE autonomous selection in an evaluating user equipment (UE), the method comprising: scheduling, using the one or more processors, periodic resources for a non-contiguous periodic transmission, the periodic resources comprising a plurality of transmission time periods for data transmission and a non-contiguous time period in which non-contiguous resources of the periodic resources are used to monitor for a conflict of the periodic resources with scheduled resources of a contending UE, wherein the non-contiguous resources are selected based on a probability value; when the conflict is detected, performing a corrective action; wherein the probability value is a low probability value less than a nominal probability value if a priority of the data transmission is greater than a predefined threshold.

16. The non-transitory computer-readable medium of claim 15, wherein multiple resources are scheduled for each period of the non-contiguous periodic transmission, and the probability value is applied independently to each of the multiple resources.

17. The non-transitory computer-readable medium of claim 15, wherein the probability value is a preconfigured or configured probability value.

18. The non-transitory computer-readable medium of claim 16, wherein in response to the evaluating that a resource reservation period (RRP) of the evaluating UE is an integer multiple of a RRP of the contending UE, and the collision is detected, transmitting a message to the contending UE to skip data transmission on scheduled resources of the contending UE that collide with the periodic resources.

19. The non-transitory computer-readable medium of claim 15, wherein when scheduling the periodic resources, the method comprises: in response to determining that a next period will be the non-consecutive time period, setting, using the one or more processors, a resource reservation period (RRP) field of a sidelink control information (SCI) message of the evaluating UE to a new value that doubles a previous RRP field value of the evaluating UE.

20. The non-transitory computer-readable medium of claim 15, wherein when scheduling the periodic resources, the method comprises: setting a bit in a sidelink control information (SCI) message to a predetermined value to indicate that a next period is the non-consecutive time period.

21. The non-transitory computer-readable medium of claim 15, wherein when performing the corrective action, the method comprises: evaluating whether a resource reservation period (RRP) of the contending UE is an integer multiple of the RRP of the evaluating UE; and when the RRP of the contending UE is an integer multiple of the RRP of the evaluating UE, stopping the non-consecutive periodic transmission on resources where the collision occurs only in the periodic resources.

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