Method for avoiding periodic resource collisions

Abstract

Systems, methods, and circuits for performing UE autonomous selection in a vehicle-to-everything (V2X) communication environment are provided, including one or more processors configured to schedule resources for discontinuous periodic transmissions with scheduled discontinuous periods during which the scheduled resources are not transmitted, wherein the one or more processors perform monitoring operations during the scheduled discontinuous periods, the monitoring operations including monitoring for collisions between the scheduled resources of the evaluating UE and the scheduled resources of a competing UE, and are further configured to selectively perform corrective actions when a collision between the scheduled resources of the evaluating UE and the scheduled resources of a competing UE is detected during the monitoring operations.

Description

Background Art

[0001] The 3GPP standardization body released the C-V2X standard to support V2X (i.e., vehicle-to-vehicle and vehicle-to-roadside) communication. NR V2X includes two operating modes identified as Mode 1 and Mode 2. Mode 1 deals with gNB (e.g., base station) scheduling, and Mode 2 deals with autonomous selection. Mode 2 does not require the support of a cellular infrastructure, and vehicles can autonomously select subchannels for V2V transmission.

[0002] Some examples of circuits, devices, and / or methods are described below by way of example only. In this context, reference is made to the accompanying drawings.

Brief Description of the Drawings

[0003]

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DETAILED DESCRIPTION OF THE INVENTION

[0004] The present disclosure will be described with reference to the accompanying drawings. The figures are not drawn to scale and are provided merely to illustrate the present disclosure. Some aspects of the present disclosure will be described below with reference to exemplary uses for illustration. Many specific details, relationships, and methods are described to provide an understanding of the present disclosure. The present disclosure is not limited to the illustrated order of operations or events because some operations may occur in a different order and / or simultaneously with other operations or events. Further, not all of the illustrated operations or events are necessary to implement the selected methodology according to the present disclosure.

[0005] As emphasized above, Mode 1 in NR V2X involves direct vehicle-to-vehicle communication with each other, but those communications are managed by a cellular infrastructure that selects subchannels and time slots or radio resources for each V2V transmission. In contrast, Mode 2 in NR V2X does not require the support of a cellular infrastructure, and vehicles autonomously select subchannels and time slots or radio resources for V2V transmission. In this framework, the 3GPP standard defines a distributed semi-persistent scheduling scheme that all vehicles must implement.

[0006] C-V2X supports 10 MHz channels and 20 MHz channels. The channels are each divided temporally into 1 ms subframes and 180 kHz resource blocks (RBs). The standard defines subchannels as groups of RBs within the same subframe. Subchannels are used to transmit data and control information. Such data is transmitted in transport blocks (TBs) via the physical sidelink shared channel (PSSCH), and control information is transmitted in sidelink control information (SCI) messages via the physical sidelink control channel (PSCCH). A TB contains a full packet and can occupy one or more subchannels. Each TB has an SCI associated with it, and both are transmitted in the same subframe. The SCI occupies a configurable number of RBs and a configurable number of OFDM symbols, and contains 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. The resource reservation period refers to the periodicity used by the vehicle to transmit its packets, and the period or interval is specified in multiples of 100 ms (e.g., 100 ms, 200 ms,....1000 ms). The information on the SCI is valuable, and therefore the SCI must be received accurately to receive and decode the TB.

[0007] In Mode 2, the vehicle autonomously selects the vehicle's subchannels and time slots using a detection-based semi-persistent scheduling (SPS) method, and the vehicle reserves the selected subchannels and time slots for several consecutive packet transmissions indicated by a reselection counter value. After such a number of transmissions, new resources or subchannels must be selected and reserved. The process by which the vehicle selects and reserves resources is a multi-step process that can be understood with reference to Figure 1. Note that although Figure 1 technically shows the two-step procedure of LTE, it should be noted that it is sufficient as an explanation for understanding the substance. At a high level, in the detection phase (or the detection window shown in Figure 1), the UE listens to the channel, i.e., listens to the channel information (SCI of other vehicles) to check which resources are already reserved. In the selection phase, candidate resources are identified and subsequently selected or reserved.

[0008] More specifically, whenever a new resource is selected, the resource can be reserved by the vehicle during a period called the selection window, as shown in FIG. 1. During this period, the vehicle identifies candidate single subframe resources (CSRs) to be reserved. A CSR is a group of adjacent subchannels within the same subframe where a packet or SCI and TB are present. If "T" is the start time of the time window (i.e., the selection window) when a new resource selection must be made, the vehicle detects all packets within the preceding detection window that includes 1000 subframes before T. The vehicle creates a list that includes all CSRs (i.e., candidate CSRs) within the detection window, except for CSRs that meet two criteria: (1) indicated in an SCI received from another vehicle (indicating that the other vehicle is using that resource simultaneously), and (2) the average reference signal received power (RSRP) measured over the resource blocks (RBs) 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 from the candidate CSRs. Thereafter, the vehicle may perform a resource selection for transmission from the identified candidate resources (CSRs) during the selection window.

[0009] As described above, in the case where periodic resource reservation is performed, when a vehicle UE starts transmission on the selected resource, it does not monitor the sidelink channel due to the half-duplex system constraint. Therefore, if another vehicle UE selects the same periodic resource for its own sidelink transmission, such competing sidelink transmissions may sometimes collide with each other continuously. This undesirable collision state is shown in FIG. 2, where UE1 and UE2 correspond to two different vehicles transmitting on the same selected time-frequency resource (i.e., the same subchannel simultaneously).

[0010] As shown in FIG. 2, the first UE 202 (e.g., UE1 corresponding to the first vehicle) has a first periodic resource reservation 204 at time t1, and the second UE 206 (e.g., UE2 corresponding to the second vehicle) has a second periodic resource reservation 208 that occupies the same time-frequency resource as the first resource reservation 204. Further, in the example of FIG. 2, both resource reservations 204 and 208 have the same periodicity 210, and thus there is not only a collision at time t1, but also data collisions continue at times t2, t3, t4, etc. In view of the understood problem highlighted above, the present disclosure provides a circuit, method, and non-transitory computer-readable medium for discontinuous periodic transmission to address this problem.

[0011] In one aspect, a UE (referred to as an evaluation UE) does not intentionally transmit in one of the scheduled reserved periods (which may also be referred to as scheduled discontinuous periods), and instead performs channel monitoring on the periodically reserved resources. During the monitoring function, if the SCI of another UE (referred to as a competing UE) is detected, some form of corrective action is selectively performed, and the form of the corrective action is based on the resource reservation period (RRP), and in some cases, based on the data priority of the competing UE. For example, in one aspect where data priority is not a factor or consideration, the form of the corrective action based on the RRP may depend on whether the RRP of the evaluation UE and the competing UE is (1) the same, (2) the RRP of the competing UE is an integer multiple of the RRP of the evaluation UE, or (3) the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE. FIGS. 3A-5 show the three conditions highlighted above to help understand how the corrective action may differ based on the relative RRP.

[0012] FIG. 3A shows the above condition (1) where the evaluation UE 302 (e.g., UE1) and the competing UE 304 (e.g., UE2) reserve the same time-frequency resource (e.g., resource 306 and resource 308 are the same). In addition, in this example, the reserved resources 306, 308 have the same periodicity 310, which means that the RPS of resources 306, 308 is the same. Therefore, without a correction operation, a data collision occurs and is not detected by either UE 302 or 304. In this example, UE 302 is the evaluation UE and selects not to transmit during a certain period (i.e., t3), and instead performs a channel monitoring operation 312 during that period. By not transmitting during the otherwise scheduled period (e.g., the scheduled discontinuous period), the evaluation UE 302 performs discontinuous periodic transmission. During the monitoring period t3, if the SCI of a competing UE indicating the same time-frequency resource having the same RRP is detected and decoded, the evaluation UE 302 stops transmitting on the colliding resources and instead starts a reselection procedure. UE 302 performs the two-step detection and selection procedure described above with respect to FIG. 1 to schedule other resources. This can be seen at 314 in FIG. 3A, where transmission is not performed at time t4, and instead a reselection procedure is started.

[0013] The above exemplary description does not consider the issue of data priority. That is, in the example of FIG. 3A, the evaluation UE 302 interrupts transmission at t4 regardless of whether the data transmission priority of the evaluation UE 302 is higher or lower than that of the competing UE 304. In one aspect, the evaluation UE 302 performs a monitoring operation 312 at t3 and decodes an SCI indicating a colliding transmission with a competing UE having the same RRP. Thereafter, the evaluation UE 302 further evaluates the data transmission priority of the competing UE 304, for example, by evaluating the decoded SCI of the competing UE 304. If the data transmission priority of the evaluation UE 302 is higher than the data transmission priority of the competing UE 304, the evaluation UE 302 does not interrupt transmission. In this case, despite the collision, due to the higher data priority, the evaluation UE 302 does not stop transmission but instead continues transmission.

[0014] In one aspect, when each of the UEs operates according to the present disclosure, the competing UE 304 may operate as an evaluation UE. In such a case, it detects the collision and higher data priority of other competing UEs, and accordingly, interrupts the transmission and starts the reselection procedure.

[0015] Thus, as emphasized above in connection with FIG. 3A, the present disclosure contemplates a UE configured to execute a process 350 of discontinuous periodic communication with another UE, or one or more processors within the UE, as described in FIG. 3B, when executing an instruction. The process 350 may be a function of an apparatus having the functions of one or more processors in the evaluation UE, may be a method, and / or may be a non-transitory computer-readable medium including instructions that, when executed by one or more processors, provide the functions described herein. At 352, one or more evaluation UE processors are configured to schedule resources for discontinuous periodic transmission. As emphasized above, such scheduling may appear similar to the scheduling of the UE 1 302 that schedules a monitoring operation during a scheduled discontinuous period (e.g., t3 in FIG. 3A) that would otherwise be used for data transmission. Such scheduling includes reservation of periodic time-frequency resources. Further details of such scheduling are described below. Details of such scheduling are described in the SCI and may include periodicity, data priority, and other parameters characterizing discontinuous periodic communication.

[0016] Referring further to FIG. 3B, one or more UE processors perform a monitoring operation by one of various methods. In one option, the monitoring operation may be pre-configured or scheduled by random selection with a probability (A) that may be a function of other criteria such as data priority. In another aspect, the selection of the monitoring process timing may follow a predefined pattern such that the nature of the discontinuous transmission itself has periodicity. Further details of how and when such monitoring is performed are described in more detail below.

[0017] During the monitoring operation at 354, one or more UE processors monitor the channel for the SCI of other transmitting UEs (i.e., competing UEs) at 356. If no other transmission is detected, or if an SCI is detected but it does not include reserved resources that would collide with the evaluation UE upon decoding ( "no" at 356), the discontinuous periodic transmission continues at 358 until the next scheduled monitoring event. However, if an SCI of a competing UE that collides with the reserved resources of the evaluation UE is detected ( "yes" at 356), one or more UE processors (i.e., the evaluation UE) perform a correction operation at 360.

[0018] In one aspect, the correction operation performed at 360 includes interrupting the periodic transmission by the evaluation UE and then starting a reselection process, and the UE performs the two-step detection and selection procedure described above in connection with FIG. 1. In another aspect, the correction operation may be selective, and the interruption of data transmission depends on the relative data priority level or some other criterion. For example, when decoding the SCI of a competing UE, if the scheduled resources collide but the relative data priorities of the evaluation UE and the competing UE satisfy some predetermined relationship, the evaluation UE does not interrupt the transmission despite the detection of the collision. For example, if the data priority of the evaluation UE is higher than that of the competing UE, the transmission may continue. Alternative other criteria may be used to make the correction operation at 360 selective.

[0019] As described above, the type of correction operation performed by the evaluation UE may vary based on the RRP of the evaluation UE and the competing UE. Option (2) corresponds to the condition where the RRP of the competing UE is an integer multiple of the evaluation UE (e.g., if the period of the evaluation UE is 100 ms, the period of the competing UE is "N" times 100 ms, where N is an integer), and is shown in FIG. 4. As shown in FIG. 4, the competing UE 404 performs a periodic transmission 408 that indicates a period that is an integer multiple of the periodic transmission 406 of the evaluation UE 402. In this example, the integer is 2, and thus, the evaluation UE 402 transmits data at twice the frequency of the competing UE 404. As seen in FIG. 4, in such a situation, collisions occur not for all evaluation UE transmissions, but for all competing UE transmissions. In this example, a collision occurs at t1, but does not occur at t2. When the evaluation UE 402 interrupts its transmission and instead performs a monitoring operation 410 at t3, the evaluation UE 402 decodes the SCI of the competing UE 404 and verifies that it has an RRP that is an integer multiple of the evaluation UE RRP (e.g., 100 ms compared to 200 ms). At this point, the evaluation UE may select any of several different options for its correction operation. In one aspect, the evaluation UE interrupts only those of its transmissions during the collision periods (e.g., 412 and 414) and continues transmission during other non-competing periods. In this case, the evaluation UE 402 does not initiate a reselection procedure and instead simply skips transmission on the colliding resources. Alternatively, the evaluation UE 402 may choose to initiate a reselection procedure. In yet another alternative aspect, when identifying the condition, the evaluation UE 402 may use other criteria when determining whether to skip the colliding periods 412, 414 or initiate a reselection. For example, if the data transmission priority of the evaluation UE 402 is "high" (e.g., above a predetermined threshold), reselection may be initiated. Alternatively, if the priority is "low" according to some predetermined criteria or threshold, reselection can be initiated. Any other substantial criteria can be used, as will be understood to be contemplated by the present disclosure.

[0020] As emphasized above, when condition (3) exists and the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE, the situation is as shown in Figure 5. As shown in Figure 5, both the evaluation UE 502 and the competing UE 504 perform periodic transmissions, and such scheduling results in collisions to occupy some of the same time-frequency resources. In this case, the evaluation UE 502 will collide in each transmission, while a part of the transmission of the competing UE 504 will collide (based on an integer multiple of the RRP). When the evaluation UE 502 executes the monitoring operation 508 at t3 instead of data transmission and discovers a problem via the SCI of the competing UE, the evaluation UE 502 may choose to interrupt the transmission and instead start a reselection process. Alternatively, upon detection of the condition, the UE may choose to message the competing UE 504 a request that the competing UE 504 skip the resources that will collide during a certain period when there will be collisions. In yet another alternative form, when determining what corrective action to take under such circumstances, the evaluation UE 502 may take into account the data priority of the evaluation UE 502 and / or the data priority of the competing UE 504. For example, when the data transmission priority of the competing UE is "high", instead of requesting the competing UE 504 to skip the transmission during the collision period, the evaluation UE 502 may choose to interrupt the transmission and start a reselection procedure.

[0021] In summary, variant forms of the corrective actions based on three different relationships between the RRP of the evaluation UE and the RRP of the competing UE are described in Figure 6. Figure 6 shows the functions executed by one or more processors of the evaluation UE. As shown in Figure 3, when a positive answer is given at 356 to the query of whether the SCI is detected in the reserved resources of the evaluation UE ( "yes" at 356), the corrective action 360 is executed. Figure 6 provides a more detailed explanation of what the corrective action may involve depending on the relationship of the ARPs between the evaluation UE and the competing UE.

[0022] First, one or more processors of the evaluation UE compare the RRP of the evaluation UE with the RRP of the competing UE via the decoded SCI of the competing UE. If the RRPs are the same (yes in 662), as shown in Figure 3A, each transmission of each UE collides. In one aspect, the evaluation UE checks, at 664, whether the data priority of the evaluation UE is lower than the data priority of the competing UE. If not (no in 664), the evaluation UE may choose, at 666, not to perform further corrective actions. This may reflect a situation where the evaluation UE has much higher priority data than the competing UE, and if the competing UE is also performing discontinuous periodic transmissions, the competing UE detects the collision, stops the transmission, and performs reselection. If it is determined that the data priority of the evaluation UE is lower than the data priority of the competing UE (yes in 664), the evaluation UE stops the transmission and performs a reselection procedure at 668. Note that the analysis at 664 regarding data priority is optional (as represented by the dashed line), and alternatively, if the conclusion at 662 is affirmative (yes), the evaluation UE may proceed directly to 668, interrupt the transmission, and perform reselection.

[0023] Referring further to FIG. 6, if the RRP of the evaluation UE and the competing UE is not the same (No in 662), at 670, it is determined whether the RRP of the competing UE is an integer multiple of the evaluation UE. If so (Yes in 670), the situation shown in FIG. 4 exists, and the evaluation UE queries at 672 whether its data priority is higher than that of the competing UE. If the evaluation UE data priority is greater (Yes in 672), no correction operation is performed at 674. That is, as shown in FIG. 4, although there are clearly data collisions at 412 and 414, since the data priority of the evaluation UE is sufficiently high according to some predetermined criterion, the evaluation UE may continue transmission. If the competing UE is also performing discontinuous periodic transmission, the competing UE may detect the condition, and since the competing UE has a lower data priority, the competing UE may stop transmission and perform reselection. If the query at 672 is negative (No in 672), the evaluation UE may choose one of two different options. In one case, the evaluation UE may stop transmitting only with respect to the colliding resources at 676 as shown in FIG. 4, canceling the resource transmission that collides with period 412 and resource 414, but continue transmission for other evaluation UE resources. In another aspect, if the evaluation UE data priority is not "high" according to some predefined criterion, the evaluation UE interrupts all data transmissions at 678 and starts a reselection process. Here too, the data priority analysis at 672 may be optional, as indicated by the dashed line.

[0024] Referring further to FIG. 6, if the result of the query at 670 is negative (i.e., "no" at 670), then at 680, another query is made as to whether the RRP of the evaluation UE is an integer multiple of the competing UE. If so (i.e., "yes" at 680), the situation is as shown in FIG. 5. Under these conditions, the evaluation UE has two available options. At 682, the evaluation UE stops transmission and performs reselection, or at 684, the evaluation UE sends a message to the competing UE to skip the transmission associated with the colliding resource. However, if the query at 680 results in a negative answer (i.e., "no" at 680), there is a situation where the RPSs of the evaluation UE and the competing UE are relatively prime to each other. For example, this situation exists when the RRP of the evaluation UE is 30 ms and the RRP of the competing UE is 100 ms. In another alternative, when the RRP of the competing UE is 0, it means that the competing UE uses only one resource and does not perform periodic transmission. In such a case, no corrective action is taken at 674.

[0025] In the examples shown in FIGS. 3 to 5, only a single set or block of resources is scheduled within each transmission period. In an alternative embodiment, multiple discontinuous sets or blocks of resources may be scheduled for periodic transmission by the UE. This example is shown in FIG. 7A, where a first UE1 702 and a second UE2 704 are performing periodic transmission, and within each transmission period, multiple discontinuous sets or blocks of time-frequency resources are scheduled for transmission. For example, the first UE1 702 has a first resource block 706 and a second resource block 708, and the second UE2 has a first resource block 710 and a second resource block 712 scheduled within each transmission period. As shown in FIG. 7A, according to the scheduling, the first resource blocks 706, 710 of the UEs 702, 704 do not collide, but the second resource blocks 708, 712 collide.

[0026] In one aspect, during the third period 714, the first UE1 702 does not transmit. Instead, it performs a monitoring operation 716 of listening for channels for the SCIs of other competing UEs. In this case, UE1 702 detects the SCI of UE2 704, decodes it, determines that the second resource blocks 708, 712 collide, and thus a correction operation must be performed. In one aspect, as shown in FIG. 7A, the first UE1 702 (i.e., the evaluation UE) stops all further transmissions on all reserved resources corresponding to both of the resource blocks 706, 708 in this case and executes a reselection procedure. In an alternative aspect, as shown in FIG. 7B, in a similar situation where only a part of the scheduled resources collide (i.e., resource blocks 708, 712 collide, but resource blocks 706, 710 do not collide), the evaluation UE702 interrupts only the transmissions on the collided resources in subsequent transmission periods and selectively executes the reselection procedure only for the collided resources.

[0027] In the example of FIGS. 7A - 7B, the evaluation UE 702 performed its monitoring operation for each resource block 706, 708 within the same transmission period 714. Alternatively, the evaluation UE may schedule, and thus perform, the monitoring operation for each of the resource blocks in different transmission periods. For example, as shown in FIG. 8A, the first UE1 802 transmits in each transmission period by the scheduled resource blocks 806, 808, and the second UE2 804 transmits within each transmission period by the scheduled resource blocks 810, 812. As shown in FIG. 8A, the first resource blocks 806, 810 of the UEs 802, 804 do not collide, but the second resource blocks 808, 812 of the UEs 802, 804 will collide. In contrast to FIG. 7A where the evaluation UE 702 performs the monitoring operation for both blocks 706, 708 in the same transmission period 714, in the manner of FIG. 8A, the evaluation UE 802 monitors 815 for the first block 806 in the second transmission period 814 and monitors 817 for the second block 808 in the third transmission period 816. As shown, the evaluation UE 802 does not detect conflicting resources for block 806 in the second transmission period 814, but detects a collision for block 808 in the third transmission period 816. In one aspect, as shown in FIG. 8A, the correction operation performed by the evaluation UE 802 is to interrupt the transmission of all resources and execute a reselection procedure for all resources.

[0028] In an alternative embodiment shown in FIG. 8B, a similar collision state is detected, i.e., a partial collision is detected. More specifically, collisions are detected for some resources (i.e., resources 808, 812 for the second resource block), but not for all resources (i.e., resources 806 and 810 for the first resource block). In this embodiment, the correction operation performed by the evaluation UE802 is, as shown in FIG. 8B, to interrupt the transmission of only the colliding resources (i.e., resources 808, 812 for the second resource block) while continuing the transmission of other non-colliding resources. In yet another alternative embodiment, the correction operation may be conditional on other criteria. For example, the priority of the data associated with the reserved resource block may be considered. If the priority of the data associated with the colliding resource block is "high" (e.g., exceeds a predetermined threshold), the colliding resources are rescheduled, and if not "high" priority, the evaluation UE802 simply interrupts the transmission on the colliding resources and maintains the transmission on the non-colliding resources.

[0029] In one embodiment, this discontinuous periodic transmission scheme highlighted herein may be selectively enabled or disabled, or in another embodiment, it may be a fixed solution, or configured per resource pool, or pre-configured. Any alternative embodiment is contemplated by the present disclosure.

[0030] As described above, the problems associated with collisions in periodic transmission are addressed by having the evaluation UE interrupt its periodic transmission and, during the period when the evaluation UE is otherwise transmitting, performing a monitoring operation to determine whether there is a competing UE having a reserved resource that conflicts with the resources of the evaluation UE, in the manner described herein and shown in FIGS. 3A, 4-5, 7A-7B, and 8A-8B. One or more ways in which the monitoring function is scheduled to form a discontinuous periodic transmission are described below.

[0031] In one aspect of the present disclosure, before each transmission on a resource within a given period, the UE determines whether to transmit in the next transmission period. If a determination is made to transmit, the UE inputs information into its SCI field information accordingly. In one aspect, the determination of whether to transmit (or monitor) in the next transmission period is made based on a random selection of whether to monitor in the next period. The random selection may have a configured or pre-configured probability (A), or may be made based on criteria such as data priority. For example, if configured or pre-configured such that the probability (A) is 10%, there is a 10% chance that the evaluation UE will not transmit but instead select to monitor during the next transmission period.

[0032] According to an alternative aspect, the probability (A) may depend on various criteria. For example, in one aspect, the probability (A) may depend on data priority. For example, in one aspect, the probability (A) may be increased for high-priority data and decreased for low-priority data in order to ensure reliable data transmission. Alternatively, the probability (A) may be decreased for high-priority data and increased for low-priority data in order to achieve more continuous data transmission and avoid collisions with higher-priority data in competing UEs.

[0033] According to another alternative aspect, the probability (A) may depend on the collision history. If a relatively large number of collisions are detected (by some predetermined threshold or criterion) in a recently predefined period, the probability (A) may be increased to monitor more frequently. If the recent history shows no collisions or few collisions, the probability (A) may be decreased. In other aspects, multiple factors or criteria may be collectively considered when forming or otherwise configuring the probability (A).

[0034] In addition, for a plurality of discontinuous resources reserved within each transmission period, such as those shown in FIG. 8A, the probability may be applied independently to each of the various scheduled resources within the period.

[0035] In another aspect, monitoring the evaluation UE may follow a predetermined pattern or periodicity. For example, in one aspect, the periodic transmission is discontinuous for monitoring every "B" period. The value B may be (pre-)configured or randomly selected from a set of pre-configured periods. For example, this set may be prime numbers to each other, such as {2, 3, 5, 7, 11}, which may avoid continuous identical discontinuous resources from different UEs. In another aspect, the selection of the value B may depend on the data priority. For example, the value B may be selected to be a smaller value for high-priority data in order to monitor more frequently to ensure more reliable transmission, and B may be a larger value for lower-priority data. In another aspect, B may be a larger value for high-priority data in order to ensure more continuous transmission for such data. In addition, in one aspect, when the periodicity B is selected, the start point also needs to be determined. In one aspect, the start period of the discontinuous resource period may be randomly selected between 0 and B-1. Alternatively, the start point may be configured, or pre-configured, or may be based on other criteria.

[0036] The above description discloses determining the frequency of making periodic transmissions discontinuous by scheduling the monitoring operation. Such a method of signal transmission with discontinuous transmissions can be implemented in various different ways. In one aspect, if the evaluation UE determines a discontinuous transmission within the next period, the evaluation UE changes the RRP (i.e., resource reservation period) field of the SCI to skip the next transmission period. In one aspect, if the current RRP is set to 100 ms, the evaluation UE sets the RRP in the SCI associated with the PSSCH one period before the discontinuous 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 discontinuous transmission is set to 800 ms to double the periodicity and effectively "skip" that particular transmission period, and thus can be used for monitoring the channel. An example of this feature is shown in FIG. 9, where the SCI field indicates one period for normal periodic transmission, and then indicates a "multiple of two periods" in the period before the monitoring operation 914 to show that the transmission on the scheduled resources skips to the "next" transmission period after the discontinuous (monitoring) period.

[0037] In another aspect, additional bits may be used in the SCI field to indicate a discontinuous transmission within the next transmission period. For example, if the spare bit is set to "0", for example, the resources within the next transmission period are reserved and the periodic transmission continues. For example, if the spare bit is set to "1", the resources within the next transmission period are not reserved, monitoring may be performed, and the resources are reserved for transmission within the period following the monitoring period.

[0038] In the various aspects described above, a discontinuous periodic transmission scheme is disclosed, and the evaluation UE stops transmission during discontinuous periods to monitor the channel for potential collisions. In another aspect, the periodic transmission is not interrupted, but instead, the transmitting UE operates as an evaluation UE and performs self-detection of collision behavior by evaluating feedback from one or more receiving UEs when HARQ feedback is enabled. Alternatively, the transmitting UE operates as an evaluation UE by looking for HARQ feedback on the sidelink feedback channel (PSFCH) resources corresponding to PSCCH and PSSCH transmissions by other transmitting UEs to inferentially confirm a collision when HARQ feedback is disabled.

[0039] In one aspect, self-detection of a collision may be performed by a transmitting UE that performs periodic transmission. For example, in sidelink unicast or groupcast transmission where HARQ feedback is enabled, the transmitting UE can evaluate the feedback received over several evaluated feedback messages and calculate what percentage of such messages are negative acknowledgments (NACK). If such a percentage of NACKs exceeds a predetermined threshold, it is determined that there is a collision with a competing UE for the scheduled resources.

[0040] As is known, unicast transmission is one-to-one communication, and the transmitting UE transmits periodic transmissions to a single specific receiving UE. In response to the unicast transmission, when HARQ feedback is enabled, the transmitting UE receives a response from the receiving UE for the sidelink data packet. Generally, HARQ-ACK is a response indicating whether the reception of the sidelink data packet was successful. The available HARQ-ACK responses include, among others, a positive response (ACK), a negative response (NACK), and DTX. Since only ACK indicates successful reception of the transmitted data, either NACK or DTX is considered "NACK" for the purposes of the present disclosure, and thus represents a transmission failure that may be due to a collision. Therefore, in periodic transmission, for continuous transmission of data, the reception of NACK or DTX is counted as a "failure", and ACK is treated as a "success". If the ratio of "failures" is greater than a threshold, the transmitting UE concludes that there is a collision with respect to the scheduled periodic resources. In such a case, for example, if the periodic transmission is interrupted and a reselection procedure is initiated, a corrective action is performed.

[0041] In one aspect, the threshold used to conclude that a collision has occurred is preconfigured or configured. In another aspect, the threshold may be based on a data service quality (QoS) parameter or a data priority level. For example, if the QoS or data priority is high, the threshold may be set lower to trigger a reselection operation only if there is only a slight possibility of a collision.

[0042] Referring to FIG. 10, for example, a UE function 1000 for self-detecting collisions in a periodic communication environment using autonomous selection is shown. Such a UE is also a transmitting UE that operates as an evaluating UE to detect collisions with competing UEs. FIG. 10 may also correspond to a method of performing self-detection of collisions in the above environment using one or more processors, and further may be accompanied by a non-transitory computer-readable medium including instructions for performing the methods described herein when executed by one or more processors.

[0043] In one aspect, function 1000 starts at 1002, and an inquiry is made as to whether HARQ feedback is enabled at the UE. Since the standard allows HARQ feedback to be selectively enabled, function 1000 provides two different options. If HARQ feedback is enabled (i.e., "yes" at 1002), the transmitting UE receives ACK / NACK type feedback in response to periodic transmissions.

[0044] Upon learning that HARQ feedback is enabled, the transmitting UE receives resources for periodic communication at 1004 and schedules such resources using one or more feedback-based collision detection parameters. Non-limiting examples of such feedback-based collision detection parameters may be as follows. One parameter may be the number of total transmissions 1006 in periodic transmission. For example, if the transmitting UE is associated with a vehicle, the transmitting UE may periodically transmit a total of 100, or 500, vehicle speeds before rescheduling is required. This information may also include a period indicating the frequency at which such data is transmitted. Another feedback collision detection parameter may be the number of data collection transmissions 1008 for collecting NACK statistics. In one example, if the total number of periodic transmissions is 100, the number of transmissions used or evaluated for collecting NACK statistics may be 10. Thus, the UE evaluates the first 10 HARQ feedbacks for 100 transmissions and makes its determination based on the 10 HARQ feedback data.

[0045] Referring further to FIG. 10, another feedback collision detection parameter may include a data collection format 1010. For example, in the example already shown, the analysis of potential collisions may be based on 10 / 100 transmission. In one data collection format 1010, only the first 10 HARQ feedback data are considered. In another aspect, each subsequent set of 10 HARQ feedback information is evaluated for transmissions 1-10, then transmissions 11-20, then transmissions 21-30, and so on throughout the transmission. In another aspect, the data collection format may be a sliding window, where 10 HARQ feedback information 1-10 are evaluated, then HARQ feedback information 5-15, then HARQ feedback information 10-20, then HARQ feedback information 15-25, and so on. The data collection format 1010 allows flexibility in customizing the way self-collision data analysis is performed.

[0046] Another feedback collision detection parameter is a threshold 1012. For example, when NACK statistics are collected, the ratio of received NACKs can be compared to a threshold, and if the ratio of NACKs exceeds the threshold, it is concluded that a collision exists on the scheduled resource. For example, if 10 out of 100 transmissions are evaluated for their HARQ feedback responses and 2 out of the 10 HARQ feedback responses are NACKs, the ratio of NACKs is 20%. If the threshold 1012 is 30%, it is concluded that there is no collision, and if the threshold is 10%, it is concluded that a collision has occurred with a competing UE on the reserved resource.

[0047] Referring back to FIG. 10, at 1004, when reserved resources are scheduled using feedback-based collision detection parameters, periodic transmission is initiated by the transmitting UE and is performed at 1014. Since the periodic transmission is being performed at 1014, NACK statistics are collected at the transmitting UE at 1016 via HARQ feedback, and such NACK statistics are collected by one or more feedback-based collision detection parameters. Function 1000 continues at 1018, and the NACK statistics are, for example, converted to a ratio and compared to a threshold 1012. If the threshold is not exceeded (a "no" at 1018), it may be concluded that there are no current collisions with respect to the reserved resources, and if the periodic transmission is still continuing (a "no" at 1020), additional NACK statistics may be collected depending on the data collection format 1010. If the periodic transmission is complete (a "yes" at 1020), since no resource collisions have been detected, no corrective action is necessary.

[0048] Referring back to operation 1018 of FIG. 10, if the calculated ratio of NACKs exceeds the threshold (a "yes" at 1018), it is concluded that a collision has occurred, and a corrective action is selectively performed at 1024. In one aspect, the corrective action is to interrupt the periodic transmission and initiate a reselection process. In one aspect, the corrective action may be selective based on various other criteria.

[0049] Returning to query 1002 in FIG. 10, if HARQ feedback is not enabled (i.e., "No" in 1002), the transmitting UE has not received HARQ feedback information. However, if another competing UE transmits and uses HARQ feedback, such information may be detected by the evaluating UE on a feedback channel such as the Physical Sidelink Feedback Channel (PSFCH) at 1030. During the monitoring of the PSFCH, if HARQ feedback is detected (i.e., "Yes" in 1032), it can be inferred that the periodic transmission performed by the evaluating UE collides with the transmission of the competing UE, and a correction operation is executed at 1024. In one example, the correction operation is to interrupt the periodic transmission and start a reselection process. For example, if HARQ feedback is not detected on the PSFCH (i.e., "No" in 1032), it is concluded that there is no collision, and no correction operation is performed at 1034. For example, the periodic transmission of the evaluating UE continues.

[0050] In the above description, the explanation has been made in relation to several flowcharts outlining exemplary methods. In this specification and the appended claims, the use of the term "determine" or "judge" when describing a method step or function with respect to some entity (e.g., parameter, variable, etc.) should be interpreted broadly. For example, "determine" or "judge" should be interpreted to include, for example, receiving and analyzing a communication encoding an entity or a value of an entity. "Determine" or "judge" should be interpreted to include accessing and reading from a memory (e.g., lookup table, register, device memory, remote memory, etc.) storing an entity or a value of an entity. "Determine" or "judge" should be interpreted to include calculating or deriving an entity or a value of an entity based on other quantities or entities. "Determine" or "judge" should be interpreted to include any method of inferring or identifying an entity or a value of an entity.

[0051] As used herein, the term "identify", when used with respect to any entity or value of an entity, should be construed broadly to include any method of determining the entity or value of the entity. For example, the term "identify" should be construed to include, for example, receiving and analyzing a communication that encodes the entity or value of the entity. The term "identify" should be construed to include accessing and reading a memory (such as a device queue, a lookup table, a register, a device memory, a remote memory, etc.) that stores the entity or value of the entity.

[0052] As used herein, the term "select", when used with respect to any entity or value of an entity, should be construed broadly to include any method of determining the entity or value of the entity from among a plurality or a range of possible choices. For example, the term "select" should be construed to include accessing and reading a memory (such as a lookup table, a register, a device memory, a remote memory, etc.) that stores the entity or value of the entity and returning one of the stored entities or values of the entity. The term "select" should be construed as applying one or more constraints or rules to a set of input parameters to determine the appropriate entity or value of the entity. The term "select" should be construed broadly to include any method of selecting an entity based on one or more parameters or conditions.

[0053] As used herein, the term "derive" should be broadly construed when used with respect to any entity or value of an entity. "Derive" shall be construed to include accessing and reading from a memory (e.g., a look-up table, a register, a device memory, a remote memory, etc.) that stores some initial value or base value, and performing processing and / or logical / mathematical operations on one or more values to generate the derived entity or value of the entity. "Derive" shall be construed to include calculating or computing an entity or value of an entity based on other quantities or entities. "Derive" shall be construed to include any method of inferring or identifying an entity or value of an entity.

[0054] As described herein, for purposes of illustration, each vehicle that uses the V2X communication principle is described as a UE (i.e., a user equipment). FIG. 11 shows a non-limiting example of a platform 1100 (or "device 1100") in various manners that may constitute the circuitry of a UE. In a plurality of manners, the computer platform 1100 may be suitable for use as a UE and / or any other element / device described herein. The platform 1100 may include any combination of the components shown by way of example. The components of the platform 1100 may be implemented as an integrated circuit (IC) adapted to the computer platform 1100, a part of an integrated circuit, an individual electronic device, or other module, logic, hardware, software, firmware, or a combination thereof, or as components incorporated in some other manner within the chassis of a larger system. The block diagram of FIG. 11 is intended to show an overview of the components of the computer platform 1100. However, some of the components shown may be omitted, additional components may exist, and different arrangements of the components shown may occur in other embodiments.

[0055] The application circuit 1105 includes, but is not limited to, one or more processors (or processor cores), cache memory, and one or more serial interfaces such as LDOs, interrupt controllers, SPI, I2C, or universal programmable serial interface modules, a timer counter including an RTC, interval and watchdog timers, general-purpose I / Os, a memory card controller such as an SD MMC, a USB interface, a MIPI interface, and a JTAG test access port. The processor (or core) of the application circuit 1105 may be coupled to a memory / storage element or may include the memory / storage element and may be configured to execute instructions stored in the memory / storage device to enable various applications or operating systems to be executed on the system 1100. In some implementations, the memory / storage element may be an on-chip memory circuit, which may include any suitable volatile and / or non-volatile memory such as DRAM, SRAM, EPROM, EEPROM, flash memory, solid state memory, and / or any other type of memory device technology as described herein.

[0056] As an example, one or more processors of the application circuit 1105 may include general-purpose processors or dedicated processors such as A-series processors (e.g., A13 Bionic) available from Apple® Inc. of Cupertino, California, or any other such processors. The processor of the application circuit 905 may also include one or more Ryzen® processors of Advanced Micro Devices (AMD), or Accelerated Processing Units (APUs), or one or more Core processors of Intel® Inc., one or more Snapdragon™ processors of Qualcomm® Technologies Inc., one or more Open Multimedia Application Platform (OMAP)™ processors of Texas Instruments Incorporated, or 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 processors of the ARM Cortex-A, Cortex-R, and Cortex-M families, and the like. In some implementations, the application circuit 1105 may be part of a system-on-chip (SoC) in which the application circuit 1105 and other components are formed on a single integrated circuit or in a single package.

[0057] The baseband circuit 1110 may be implemented, for example, as a soldered substrate including one or more integrated circuits, a single package integrated circuit soldered to the main circuit board, or a multi-chip module including two or more integrated circuits.

[0058] The platform 1100 may also include an interface circuit (not shown) used to connect an external device to the platform 1100. An external device connected to the platform 1100 via the interface circuit includes a detection circuit 1121 and an electromechanical component (EMC) 1122, and a removable memory device coupled to a removable memory circuit 1123.

[0059] The battery 1130 may supply power to the platform 1100 and may have a power source coupled to a power grid. The battery 1130 may be a lithium-ion battery, or a metal-air battery such as a zinc-air battery, an aluminum-air battery, or a lithium-air battery. In some implementations such as V2X applications, the battery 1130 may be a typical lead-acid automotive battery.

[0060] Although the method has been illustrated and described above as a series of operations or events, it is understood that the illustrated order of such operations or events should not be construed in a limiting sense. For example, some operations may occur in a different order and / or concurrently with other operations or events not illustrated and / or described herein. Additionally, not all illustrated operations are required to implement one or more aspects or examples of the present disclosure. Also, one or more of the operations shown herein may be performed in one or more separate operations and / or stages. In some examples, the above method may be implemented on a computer-readable medium using instructions stored in a memory. Many other examples and variations are possible within the scope of the claimed disclosure. Examples

[0061] Example 1 is an evaluation user equipment (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 discontinuous periodic transmission having a scheduled discontinuous period during which the scheduled resources are not transmitted, and to perform a monitoring operation during the scheduled discontinuous period, the monitoring operation including monitoring for a collision between the scheduled resources of the evaluation UE and the scheduled resources of a competing UE. The one or more processors are also configured to selectively perform a correction operation when a collision between the scheduled resources of the evaluation UE and the scheduled resources of a competing UE is detected during the monitoring operation.

[0062] Example 2 includes the subject matter of Example 1, and when scheduling resources for discontinuous periodic transmission, the one or more processors are configured to determine whether the evaluation UE will transmit during the next transmission period based on a random selection having a probability that the next transmission period is a discontinuous period and thus not scheduled for data transmission within the next transmission period.

[0063] Example 3 includes the subject matter of Example 2, and the probability is a preconfigured probability value.

[0064] Example 4 includes the subject matter of claim 2, and the probability depends on the data priority associated with the scheduled resources.

[0065] Example 5 includes the subject matter of Example 4, and when the data priority is greater than a predefined threshold value, the probability is a high probability value greater than the nominal probability value.

[0066] Example 6 includes the subject matter of Example 1, and when scheduling resources for discontinuous periodic transmission, one or more processors are configured to determine whether the evaluated UE will transmit within the next transmission period based on a predefined periodicity of the scheduled discontinuous periods during which the scheduled resources are not transmitted.

[0067] Example 7 includes the subject matter of Example 6, and the predefined periodicity is randomly selected from a set of preconfigured periods.

[0068] Example 8 includes the subject matter of Example 6, and the predefined periodicity depends on the data priority associated with the scheduled resources.

[0069] Example 9 includes the subject matter of Example 1, and when scheduling resources for discontinuous periodic transmission, one or more processors are configured to determine that the next period is a discontinuous transmission period and set the resource reservation period (RRP) field of the sidelink control information (SCI) message of the evaluated UE to a new value that doubles the period of periodic transmission with respect to the previous RRP field value of the evaluated UE.

[0070] Example 10 includes the subject matter of Example 1, and when scheduling resources for discontinuous periodic transmission, one or more processors are configured to determine that the next period is a discontinuous transmission period and set the bits in the sidelink control information (SCI) message field to a predetermined value indicating that the scheduled resources within the next transmission period are not reserved for data transmission, but the scheduled resources within the transmission period following the next transmission period are reserved for data transmission.

[0071] Example 11 includes the subject matter of Example 1, and when performing a monitoring operation during a scheduled discontinuous period, one or more processors evaluate one or more associated frequency channels for side link control information (SCI) messages of one or more competing UEs, and for each SCI message detected on an associated frequency channel, determine whether any scheduled resources of one or more competing UEs collide with the scheduled resources of the evaluating UE.

[0072] Example 12 includes the subject matter of Example 1, and when selectively performing a correction operation when a collision is detected, one or more processors evaluate whether the resource reservation period (RRP) of a competing UE is the same as the RRP of the evaluating RRP, selectively stop discontinuous periodic transmission by the evaluating UE on the scheduled resources, and perform a reselection operation for rescheduling resources for discontinuous periodic transmission on different reserved resources.

[0073] Example 13 includes the subject matter of Example 12, and one or more processors determine whether the data priority of the evaluating UE is greater than the data priority of the competing UE, and when the data priority of the evaluating UE is greater than the data priority of the competing UE, are further configured not to perform a correction operation.

[0074] Example 14 includes the subject matter of Example 1, and when selectively performing a correction operation when a collision is detected, one or more processors evaluate whether the resource reservation period (RRP) of a competing UE is an integer multiple of the RRP of the evaluating UE, and when the RRP of the competing UE is an integer multiple of the RRP of the evaluating UE, are configured to selectively stop periodic transmission only on the reserved resources of the evaluating UE that collide with the transmission of the competing UE.

[0075] Example 15 includes the subject matter of Example 14, and one or more processors determine whether the data priority of the evaluating UE is greater than the data priority of the competing UE, and when the data priority of the evaluating UE is greater than the data priority of the competing UE, are configured not to perform a correction operation.

[0076] Example 16 includes the subject matter of Example 1, and when selectively performing a corrective action when a collision is detected, one or more processors evaluate whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE. When the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE, a message is sent from the evaluation UE to the competing UE, and it is configured to skip periodic transmissions on the scheduled resources that collide with the scheduled resources of the evaluation UE.

[0077] Example 17 includes the subject matter of Example 1, and when selectively performing a corrective action when a collision is detected, one or more processors evaluate whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, stop discontinuous periodic transmissions, and are configured to perform a reselection action to reschedule resources for discontinuous periodic transmissions on different reserved resources.

[0078] Example 18 relates to a method for performing user equipment (UE) autonomous selection in an evaluation UE. The method includes scheduling resources for discontinuous periodic transmissions having a scheduled discontinuous period during which the scheduled resources are not transmitted using one or more processors, and performing a monitoring operation during the scheduled discontinuous period, the monitoring operation including monitoring, by one or more processors, for a collision between the scheduled resources of the evaluation UE and the scheduled resources of a competing UE. The method also includes selectively performing a corrective action using one or more processors when a collision between the scheduled resources of the evaluation UE and the scheduled resources of the competing UE is detected during the monitoring operation.

[0079] Example 19 includes the subject matter of Example 18, and when scheduling resources for discontinuous periodic transmission, the method includes determining whether an evaluated UE transmits within a next transmission period based on a random selection having a probability that the next transmission period is a discontinuous period and thus not scheduled for data transmission within the next transmission period.

[0080] Example 20 includes the subject matter of Example 19, and the probability is a preconfigured probability value.

[0081] Example 21 includes the subject matter of Example 19, and the probability depends on a data priority associated with the scheduled resources.

[0082] Example 22 includes the subject matter of Example 21, and the probability is a high probability value greater than a nominal probability value when the data priority is greater than a predefined threshold.

[0083] Example 23 includes the subject matter of Example 18, and when scheduling resources for discontinuous periodic transmission, the method includes determining whether an evaluated UE transmits within a next transmission period based on a predefined periodicity of a scheduled discontinuous period in which the scheduled resources are not transmitted.

[0084] Example 24 includes the subject matter of Example 23, and the predefined periodicity is randomly selected from a set of preconfigured periods.

[0085] Example 25 includes the subject matter of Example 23, and the predefined periodicity depends on a data priority associated with the scheduled resources.

[0086] Example 26 includes the subject matter of Example 18. When scheduling resources for discontinuous periodic transmission, the method uses one or more processors to determine that the next period is a discontinuous transmission period, and uses one or more processors to set the resource reservation period (RRP) field of the sidelink control information (SCI) message of the evaluation UE to a new value that doubles the period of periodic transmission with respect to the previous RRP field value of the evaluation UE.

[0087] Example 27 includes the subject matter of Example 18. When scheduling resources for discontinuous periodic transmission, the method determines that the next period is a discontinuous transmission period, and sets the bits in the sidelink control information (SCI) message field to a predetermined value indicating that the scheduled resources within the next transmission period are not reserved for data transmission, but the scheduled resources within the transmission period following the next transmission period are reserved for data transmission.

[0088] Example 28 includes the subject matter of Example 18. When performing a monitoring operation during a scheduled discontinuous period, the method evaluates one or more associated frequency channels for the sidelink control information (SCI) messages of one or more competing UEs, and for each SCI message detected on the associated frequency channel, determines whether any of the scheduled resources of one or more competing UEs collide with the scheduled resources of the evaluation UE.

[0089] Example 29 includes the subject matter of Example 18. When selectively performing a correction operation when a collision is detected, the method evaluates whether the resource reservation period (RRP) of the competing UE is the same as the RRP of the evaluation RRP, and selectively stops the discontinuous periodic transmission by the evaluation UE on the scheduled resources, and performs a reselection operation for rescheduling resources for discontinuous periodic transmission on different reserved resources.

[0090] Example 30 includes the subject matter of Example 29, and further includes determining whether the data priority of the evaluation UE is greater than the data priority of the competing UE, and when the data priority of the evaluation UE is greater than the data priority of the competing UE, not performing a correction operation.

[0091] Example 31 includes the subject matter of Example 18. When selectively executing a correction operation when a collision is detected, the method includes evaluating whether the resource reservation period (RRP) of the competing UE is an integer multiple of the RRP of the evaluation UE, and when the RRP of the competing UE is an integer multiple of the RRP of the evaluation UE, selectively stopping the periodic transmission only on the reserved resources by the evaluation UE that collides with the transmission of the competing UE.

[0092] Example 32 includes the subject matter of Example 31, and further includes determining whether the data priority of the evaluation UE is greater than the data priority of the competing UE, and when the data priority of the evaluation UE is greater than the data priority of the competing UE, not performing a correction operation.

[0093] Example 33 includes the subject matter of Example 18. When selectively executing a correction operation when a collision is detected, the method includes evaluating whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, and when the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE, further includes sending a message from the evaluation UE to the competing UE to skip the periodic transmission on the scheduled resources that collide with the scheduled resources of the evaluation UE.

[0094] Example 34 includes the subject matter of Example 18. When selectively executing a correction operation when a collision is detected, the method includes evaluating whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, and performing a re-selection operation to stop the discontinuous periodic transmission and re-schedule resources for the discontinuous periodic transmission on different reserved resources.

[0095] Example 35 relates to a non-transitory computer-readable medium including instructions that, when executed by one or more processors, are configured to perform a method for performing user equipment (UE) autonomous selection in an evaluation UE. Such a method includes using one or more processors to schedule resources for discontinuous periodic transmissions having scheduled discontinuous periods during which the scheduled resources are not transmitted, and performing a monitoring operation during the scheduled discontinuous periods, the monitoring operation including monitoring, by one or more processors, for a collision between the scheduled resources of the evaluation UE and the scheduled resources of a competing UE, and selectively performing a correction operation using one or more processors when a collision between the scheduled resources of the competing UE and the scheduled resources of the evaluation UE is detected during the monitoring operation.

[0096] Example 36 includes the subject matter of Example 35 and, when scheduling resources for discontinuous periodic transmissions, the method includes determining, based on a random selection having a probability that the next transmission period is a discontinuous period and thus not scheduled for data transmission within the next transmission period, whether the evaluation UE will transmit within the next transmission period.

[0097] Example 37 includes the subject matter of Example 36 and the probability is a preconfigured probability value.

[0098] Example 38 includes the subject matter of Example 36 and the probability depends on the data priority associated with the scheduled resources.

[0099] Example 39 includes the subject matter of Example 38 and the probability is a high probability value greater than a nominal probability value when the data priority is greater than a predefined threshold.

[0100] Example 40 includes the subject matter of Example 35. When scheduling resources for discontinuous periodic transmission, the method includes determining whether the evaluated UE will transmit within the next transmission period based on a predefined periodicity of the scheduled discontinuous periods during which the scheduled resources are not transmitted.

[0101] Example 41 includes the subject matter of Example 40, and the predefined periodicity is randomly selected from a set of preconfigured periods.

[0102] Example 42 includes the subject matter of Example 40, and the predefined periodicity depends on the data priority associated with the scheduled resources.

[0103] Example 43 includes the subject matter of Example 35. When scheduling resources for discontinuous periodic transmission, the method includes using one or more processors to determine that the next period is a discontinuous transmission period, and using one or more processors to set the resource reservation period (RRP) field of the sidelink control information (SCI) message of the evaluated UE to a new value that doubles the period of periodic transmission with respect to the previous RRP field value of the evaluated UE.

[0104] Example 44 includes the subject matter of Example 35. When scheduling resources for discontinuous periodic transmission, the method includes determining that the next period is a discontinuous transmission period, and setting bits in the sidelink control information (SCI) message field to a predetermined value indicating that the scheduled resources within the next transmission period are not reserved for data transmission, but the scheduled resources within the transmission period following the next transmission period are reserved for data transmission.

[0105] Example 45 includes the subject matter of Example 35. When performing a monitoring operation during a scheduled discontinuous period, the method includes evaluating one or more associated frequency channels for side link control information (SCI) messages of one or more competing UEs, and for each SCI message detected on an associated frequency channel, determining whether any scheduled resources of one or more competing UEs collide with the scheduled resources of the evaluating UE.

[0106] Example 46 includes the subject matter of Example 35. When selectively performing a correction operation when a collision is detected, the method includes evaluating whether the resource reservation period (RRP) of a competing UE is the same as the RRP of the evaluating RRP, and selectively stopping discontinuous periodic transmission by the evaluating UE on the scheduled resources and performing a reselection operation for rescheduling resources for discontinuous periodic transmission on different reserved resources.

[0107] Example 47 includes the subject matter of Example 46 and further includes determining whether the data priority of the evaluating UE is greater than the data priority of the competing UE, and when the data priority of the evaluating UE is greater than the data priority of the competing UE, not performing a correction operation.

[0108] Example 48 includes the subject matter of Example 35. When selectively performing a correction operation when a collision is detected, the method includes evaluating whether the resource reservation period (RRP) of a competing UE is an integer multiple of the RRP of the evaluating UE, and when the RRP of the competing UE is an integer multiple of the RRP of the evaluating UE, selectively stopping periodic transmission only on the reserved resources that collide with the transmission of the competing UE by the evaluating UE.

[0109] Example 49 includes the subject matter of Example 48 and further includes determining whether the data priority of the evaluating UE is greater than the data priority of the competing UE, and when the data priority of the evaluating UE is greater than the data priority of the competing UE, not performing a correction operation.

[0110] Example 50 includes the subject matter of Example 35. When selectively performing a corrective operation when a collision is detected, the method further includes evaluating whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, and when the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE, sending a message from the evaluation UE to the competing UE to skip periodic transmissions on the scheduled resources that collide with the scheduled resources of the evaluation UE.

[0111] Example 51 includes the subject matter of Example 35. When selectively performing a corrective operation when a collision is detected, the method includes evaluating whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, and performing a reselection operation to stop discontinuous periodic transmissions and re-schedule resources for discontinuous periodic transmissions on different reserved resources.

[0112] The term "coupled" is used throughout this specification. This term can cover a connection, communication, or 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 operation, in a first example, Device A is coupled to Device B, or in a second example, if the intervening component C does not substantially change the functional relationship between Device A and Device B such that Device B is controlled by Device A via a control signal generated by Device A, then Device A is coupled to Device B via the intervening component C.

[0113] The use of personal information should be fully understood to comply with privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personal information data should be managed and handled to minimize the risk of unintended or unauthorized access or use, and the nature of the permitted use should be clearly indicated to the user.

Claims

1. A user equipment (UE) for evaluation, comprising a memory and one or more processors communicatively coupled to the memory, wherein the one or more processors schedule a periodic resource having a plurality of transmission periods for data transmission and discontinuous periods not for data transmission by the evaluation UE for discontinuous periodic transmission, and the plurality of transmission periods and the discontinuous periods are separated in the time domain, configured to perform a monitoring operation in the scheduled discontinuous period without performing data transmission, the monitoring operation monitoring for a collision between the scheduled periodic resource and the scheduled resources of competing UEs, evaluating whether a resource reservation period (RRP) of the competing UE is an integer multiple of the RRP of the evaluation UE, when the RRP of the competing UE is an integer multiple of the RRP of the evaluation UE, stopping the discontinuous periodic transmission only on the resource of the periodic resource where the collision occurs, including performing a correction operation when the collision is detected. The evaluation UE.

2. When scheduling the periodic resource for the discontinuous periodic transmission, the one or more processors are configured to determine whether the evaluation UE transmits within the next transmission period based on a random selection having a probability that the next transmission period is the discontinuous period. The evaluation UE according to claim 1.

3. The evaluation UE according to claim 2, wherein the probability is a preconfigured or configured probability value.

4. The evaluation UE according to claim 2, wherein the probability depends on a data priority associated with the scheduled resource.

5. The evaluation UE according to claim 4, wherein the probability is a high probability value greater than a nominal probability value when the data priority is greater than a predefined threshold.

6. When scheduling the periodic resource for the discontinuous periodic transmission, the one or more processors determine that the next period will be the discontinuous period, [[ID ​ ​ The evaluation UE according to claim 1, wherein a resource reservation period (RRP) field of the sidelink control information (SCI) message of the evaluation UE is configured to be set to a new value that doubles a previous RRP field value of the evaluation UE.

7. When scheduling the periodic resources for the discontinuous periodic transmission, the one or more processors determine that a next period is the discontinuous period, and configure bits in a sidelink control information (SCI) message field to be set to a predetermined value indicating that the scheduled resources within the next transmission period are not reserved for data transmission, but the scheduled resources within a transmission period following the next transmission period are reserved for data transmission. The evaluation UE according to claim 1.

8. A non-transitory computer-readable medium including instructions, wherein when such instructions are executed by one or more processors, they are configured to execute a method for performing user equipment (UE) autonomous selection in an evaluation UE, and the method includes scheduling periodic resources for discontinuous periodic transmission, wherein the periodic resources include a plurality of transmission periods for data transmission and discontinuous periods for monitoring collisions between the scheduled resources of competing UEs and the periodic resources, and the plurality of transmission periods and the discontinuous periods are separated in a time domain; evaluating whether a resource reservation period (RRP) of a competing UE is an integer multiple of the RRP of the evaluation UE; when the RRP of the competing UE is an integer multiple of the RRP of the evaluation UE, stopping periodic transmission only on the resources of the periodic resources where the collision occurs; and when the collision is detected, performing a correction operation. A non-transitory computer-readable medium including instructions.

9. When monitoring the collision, the method includes evaluating one or more associated frequency channels for sidelink control information (SCI) messages of one or more competing UEs; For each SCI message detected on the associated frequency channel, determining whether any scheduled resource of the one or more competing UEs collides with the periodic resource, the non-transitory computer-readable medium according to claim 8.

10. The method being When the data priority of the evaluation UE is greater than the data priority of the competing UE, not performing a correction operation, The non-transitory computer-readable medium according to claim 8.

11. When executing the correction operation, the method being Evaluating whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, When the RRP of the evaluation UE is an integer multiple of the RRP of the competing UE, further including transmitting a message to the competing UE to skip data transmission on the resource of the scheduled resource of the competing UE that collides with the scheduled periodic resource of the evaluation UE, the non-transitory computer-readable medium according to claim 8.

12. When executing the correction operation, the method being Evaluating whether the resource reservation period (RRP) of the evaluation UE is an integer multiple of the RRP of the competing UE, Stopping the discontinuous periodic transmission and performing a reselection operation for rescheduling resources for the discontinuous periodic transmission on different reserved resources, the non-transitory computer-readable medium according to claim 8.

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