Preemptive reservation of communication resources

Abstract

To make it possible to avoid, or at least reduce the likelihood of, two or more UE devices using preemptive reservations to transmit over most recently released communication resources.SOLUTION: A first user equipment (UE) device preemptively reserves a communication resource where the communication resource had been previously reserved by a second UE device for transmission. In response to an indication that the communication resource has been released from the second UE device reservation, the first UE device transmits over the communication resource.SELECTED DRAWING: Figure 4

Description

Claiming priority

[0001] This application claims priority to Provisional Patent Application No. 62 / 910188, "Pre-emptive Resource Reservation in NR-V2V Communication Network," filed on October 3, 2019, Docket No. TPRO 00344 US, which is assigned to the assignee hereof and is expressly incorporated by reference in its entirety. [Technical field]

[0002] The present invention relates generally to wireless communications, and more particularly to preemptive reservation of communications resources. [Background technology]

[0003] Existing and proposed communication systems employ techniques for establishing ad-hoc networks in which communication devices autonomously select communication resources for data transmission. In distributed scheduling, a communication device can reserve future communication resources by sending a message to neighboring communication devices notifying them of the reservation. The neighboring communication devices take the communication resource reservation into account when selecting communication resources for data transmission. Summary of the Invention

[0004] A first user equipment (UE) device preemptively reserves communications resources that were previously reserved by a second UE device for transmission, and in response to an indication that the communications resources have been released from reservation by the second UE device, the first UE device transmits on the communications resources. [Brief description of the drawings]

[0005] [Figure 1A] 1 is a block diagram illustrating an example of a communications system including a plurality of user equipment (UE) devices in which reserved communications resources are released.

[0006] [Figure 1B] FIG. 2 illustrates an example comparison between transmission with and without preemptive reservation.

[0007] [Figure 1C] FIG. 2 illustrates a UE device with high priority data transmitting in preemption of a transmission by another UE device that has previously reserved communication resources.

[0008] [Diagram 2] FIG. 2 is a block diagram illustrating an example of a communication device suitable for use as each communication device.

[0009] [Diagram 3] 1 is a block diagram illustrating an example of a UE device suitable for use as each UE device.

[0010] [Figure 4] 1 is a flow chart illustrating an example method for contending for communications resources using preemptive reservations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As mentioned above, an ad-hoc network can be established by a communication device reserving communication resources for future transmission. For example, the Rel-14 communication standard of the 3rd Generation Partnership Project (3GPP) (registered trademark, the same applies below) specifies communication with vehicles in C-V2X (LTE rel-14 V2X) mode 4 and New Radio (NR) V2X mode 2, where the communication device autonomously selects the time slot / frequency sub-band resource for data transmission. In a vehicular ad-hoc network (VANET) based on time division multiple access (TDMA), autonomously selecting the time slot for data transmission may result in collisions if two or more devices select the same time slot. In a distributed scheduling system, communication devices interested in transmitting data schedule a time slot for a future time (t0+tk ) at time t0 indicating the resources to use for data transmission. Neighboring devices receive and decode the reservation signal before considering their own resource selection for data transmission to avoid collisions. In the examples herein, a user equipment (UE) device preemptively reserves communication resources reserved by other UE devices and uses the communication resources for transmission if the communication resource reservation by the other UE device is released before the transmission time.

[0012] 1A is a block diagram of an example communication system 10 including multiple user equipment (UE) devices 12, 14, 16 in which reserved communication resources are released. While the techniques described herein are applicable to various types of systems and communication standards, the devices in this example operate in accordance with 3GPP New Radio (NR) V2X and LTE C2X (Rel-14).

[0013] In the example herein, three UE devices 12, 14, 16 are located in a region where the same communication resources are available to each UE device 12, 14, 16. The example begins with a first UE device (UE device 1) 12 in communication 18 with a first communication device 20. The first communication device 20 may be any type of device capable of receiving signals from the first UE device 12 and transmitting signals to the first UE device 12, for example, another UE device, a base station, an access point, or a transceiver station. During the communication 18, the first UE device 12 reserves the communication resources and prevents other UE devices in the region from transmitting signals using the reserved communication resources. Continuing with the example, the reserved communication resources 22 are no longer needed for the communication 18 and the communication resources 22 are considered to be released so that other devices can use the communication resources 22. In the present example, a second UE device (UE device 2) 14 has initiated or engaged in a communication 24 with a second communication device 26, and a third UE device 16 has initiated or engaged in a communication 28 with a third communication device 30. Each of the communication devices 26, 30 may be any type of device capable of receiving signals from and transmitting signals to the second UE device 14, the third UE device 16, such as other UE devices, base stations, access points, or transceiver stations. Although the communication devices 20, 26, 30 are shown as separate devices, in some circumstances, two or more of the communication devices may be the same device. For example, the first communication device 20 and the second communication device 26 may be the same device. In conventional systems, two or more UE devices may attempt to transmit on the newly released communication resource 22. For example, the second and third UE devices may transmit at the same time and on the same frequency, resulting in collision of the transmitted signals.

[0014] As described in more detail below, the techniques described herein avoid, or at least reduce the likelihood, of two or more UE devices using preemptive reservation to transmit on a recently released communications resource 22. In the example of FIG. 1A, the second UE device 14 preemptively reserves the communications resource 22 after it is reserved by the first UE device 12 and before it is released. The third UE device 16 detects the preemptive reservation and does not transmit a signal using the released communications resource 22. As a result, there is no collision between the transmission 32 from the second UE device 14 and the transmission 34 from the third UE device 16, as occurs in the prior art.

[0015] FIG. 1B illustrates a comparative transmission example 100 of a transmission 102 with preemptive reservation and a transmission 104 without preemptive reservation. The transmission described with reference to FIG. 1B may be performed by the communication arrangement described above with reference to FIG. 1A. In the transmission 104 without preemptive reservation, a collision occurs when two UE devices attempt to use the same communication resource that has been released from reservation by the first UE device 12. In the example of FIG. 1B, the available frequency spectrum is divided into frequency portions (subbands) and by time to create multiple frequency-time communication resources. Thus, each block of frequency and time is a communication resource as described herein. Multiple blocks can be used in combination to create larger communication resources. A particular system may employ any number of communication resources and may use any of several different frequency portion lengths and durations for the communication resources. In the examples herein, the communication resources are in accordance with 3GPP communication standards such as Rel-14 LTE C-V2X and Rel-16 NR V2X. In an example transmission 104, a first subscribing UE device (UE device 1) 12 transmits a first signal 106 at time t0, the first signal 106 including data and a communication reservation indication 108 indicating that the subscribing UE device is transmitting a communication reservation at a future transmission time (t0+t k1B indicates that the first UE device 12 has reserved a communication resource 120 for a future transmission time (t0+t1). The communication resource of FIG. 1B is an example of the communication resource 22 of FIG. 1A. The first signal 106 is part of a communication 18 between the first UE device 12 and a communication device 20, such as another UE device, a base station, or a wireless transceiver. In the example herein, the reservation is a reservation of a transmission based on HARQ from the reserving UE device. If the first signal is not correctly received at the communication device 20, the communication device 20 transmits a negative acknowledgement (NACK) signal. In the example herein, a NACK 114 is transmitted in response to the first signal 106. As a result, the first UE device 12 transmits a second signal 116 using the reserved communication resource 110. The second signal 116 includes data and a communication reservation indication 118, which indicates that the reserving UE device has reserved a communication resource 120 for a future transmission time (t0+t1). k +t m ) 122 indicates that it has reserved the communications resources 120. In response to successful reception of the second signal 116, the communications device 20 transmits an acknowledgement (ACK) signal 124. The ACK signal 124 indicates to UE devices in the area, such as a second UE device (UE device 2) 14 and a third UE device (UE device 3) 16, that the communications resources 120 reserved by the first UE device 12 have been released. As a result, the second UE device 14 and the third UE device 16 transmit signals 126, 128 using the newly released communications resources 120. Although the second UE device 14 and the third UE device 16 may attempt to reserve the communications resources 120 before transmitting, the relatively short time between the ACK signal 124 and the transmission time 112 is insufficient for either UE device to determine that the resources have been reserved. As a result, collisions occur between the signals 126 , 128 and typically neither signal is received correctly by the intended recipient, such as the second communication device 26 and the third communication device 30 .

[0016] In contrast, a transmission 102 with preemptive reservation by a UE device avoids collisions. The example transmission 102 is similar to the example transmission 104 without preemptive reservation, except that the second UE device 14 preemptively reserves the communication resources 120 released from reservation by the first UE device 12. After detecting the reservation indicator 118 in the second signal 116, the second UE device 14 transmits a signal 130 including a preemptive reservation indicator 132. The preemptive reservation indicator may be transmitted either in the SCI field of the control channel or in a message of a data channel transmission. Other UE devices in the area, such as the third UE device 16, receive the preemptive reservation indicator 132. After receiving the ACK signal 124, the second UE device 14 determines that the communication resources 120 have been released from the reservation placed by the first UE device 12. The second UE device 14 transmits a signal 134 using the preemptively reserved communication resources 120. Other UE devices in the area, such as a third UE device 16, receive the preemptive reservation indicator 118 and refrain from transmitting over the communications resource 120 in response to receiving the preemptive reservation indicator 118. As a result, signal collisions may be avoided. Continuing with the example, a signal 134 transmitted by a second UE device 14 includes a reservation indicator 136 indicating that another communications resource 138 has been reserved. An intended recipient of the signal 134 transmits a NACK signal 140 indicating that the signal 134 was not successfully received. After receiving the NACK signal 140, the second UE device 14 transmits another signal 142 using the communications resource 138. Because the communications resource 138 has been reserved by the second UE device 14, the other UE device does not transmit using the communications resource 138.

[0017] In some circumstances, the released communication resource 120 may be reserved only for the transmission of high priority data or packets. For example, rules or procedures may be implemented that require a UE device to have high priority data to transmit on the communication resource before preemptively reserving the communication resource. In some circumstances, the newly released communication resource 120 may be used for the transmission of lower priority data if the communication resource 120 has not been preemptively reserved. In accordance with known techniques, data is designated with at least two priorities for such circumstances. Multiple priority levels may be used.

[0018] FIG. 1C illustrates a UE device having higher priority data reserving communication resources in advance. FIG. 1C illustrates a transmission 150 that preempts a transmission by another UE device that has reserved it. In some circumstances, a UE device transmitting higher priority data uses the communication resource after preemptively reserving the communication resource reserved by a UE device transmitting lower priority data, and the UE device with lower priority data refrains from using the communication resource. Referring to FIG. 1C as an example, a first UE device 12 reserves a communication resource 152 and a second UE device 14 preemptively reserves the communication resource 152 by transmitting a preemptive reservation indicator 132. In the example herein, the data transmitted by the second UE device 14 has a higher priority than the priority of the data transmitted on the communication resource 152 reserved by the first UE device 12. A NACK 154 is transmitted indicating that the previous transmission 116 from the first UE device 12 was not successfully received. However, in this example, the first UE device 12 refrains from transmitting on the communication resource 152 due to the relative priority of the data transmitted by the first UE device 12 and the second UE device 14. Thus, the preemptive reservation 132 of the second UE device 14 releases communication resources 152. In the examples herein, the priority level of the data is assigned from higher layers and the priority state (level) of the data is signaled to lower layers. Each UE device indicates the priority of the data in the sidelink control information. Thus, the second UE device determines the priority level of the first data from the sidelink control message transmitted from the first UE device.

[0019] Thus, in this embodiment, the first UE device 12 transmits a reservation indicator 118 to reserve a communication resource 152 for a transmission from the first UE device 12 of a first data having a first priority level. The second UE device 14 determines whether to use the communication resource for a transmission of a second data having the second priority level based at least in part on the first priority level and the second priority level. If the second UE device 14 determines that the communication resource can be used for the transmission of the second data, the second UE device 14 further transmits a preemptive reservation indicator. The preemptive reservation indicator preemptively reserves the communication resource for the transmission of the second data. The second UE device 14 then transmits the second data using the communication resource.

[0020] FIG. 2 is a block diagram of an example of a communication device 200 suitable for use as each of the communication devices 20, 26, 30. The communication device 200 includes a control unit 204, a transmitter unit 206, and a receiver unit 208, as well as other electronics, hardware, and code. The communication device 200 may be any fixed, mobile, or portable device that performs the functions described herein. The various functions and operations of the blocks described with reference to the communication devices 20, 26, 30, 200 may be implemented in any number of devices, circuits, or elements. Two or more functional blocks may be integrated into a single device, and functions described as being performed in any single device may be implemented across several devices. The communication device 200 may be a fixed device or equipment that is installed at a specific location during system installation. Examples of such equipment include fixed base stations or fixed transceiver stations. Although base stations may be referred to by different terms, when operating according to one or more communication standards for 3GPP NR operation, base stations are typically referred to as gNodeBs or gNBs. In some circumstances, the communication device 200 may be a mobile device that is temporarily installed at a particular location. Examples of such devices include mobile transceiver stations equipped with power generating equipment such as generators, solar panels, batteries, etc. Larger, heavier versions of such equipment may be transported on trailers. In still other circumstances, the communication device 200 may be a portable device that is not fixed to any particular location. As mentioned above, the communication device 200 may be a UE device in some circumstances.

[0021] The controller 204 includes any combination of hardware, software, and / or firmware for performing the functions described herein and facilitating the overall functionality of the communication device 200. An example of a suitable controller 204 includes code running on a microprocessor or processor array coupled to memory. The transmitter 206 includes electronics for transmitting wireless signals. In some circumstances, the transmitter 206 may include multiple transmitters. The receiver 208 includes electronics for receiving wireless signals. In some circumstances, the receiver 208 may include multiple receivers. The receiver 208 and the transmitter 206 receive and transmit signals, respectively, through an antenna 210. The antenna 210 may include separate transmit and receive antennas. In some circumstances, the antenna 210 may include multiple transmit and receive antennas.

[0022] The transmitter 206 and receiver 208 in the example of FIG. 2 perform radio frequency (RF) processing including modulation and demodulation. Thus, the receiver 208 may include components such as a low noise amplifier (LNA) and a filter. The transmitter 206 may include a filter and an amplifier. Other components may include isolators, matching circuits, and other RF components. These components may perform the functions of the communication device in combination or cooperation with other components. The required components may depend on the particular functions required by the communication device.

[0023] The transmitter 206 includes a modulator (not shown) and the receiver 208 includes a demodulator (not shown). The modulator modulates the signal transmitted as part of the downlink signal and may apply any one of a number of modulation orders. The demodulator demodulates any uplink signal received by the communication device 200 according to one of a number of modulation orders.

[0024] If the communication device is a base station, the communication device 200 includes a communication interface 212 for transmitting and receiving messages to and from other base stations. The communication interface 212 may be connected to a backhaul or network that allows communication with other base stations. In some circumstances, the link between base stations may include at least some wireless portions. Thus, the communication interface 212 may include wireless communication capabilities and may utilize some of the components of the transmitter 206 and / or receiver 208.

[0025] The communication device 200 has the capability to monitor one or more channels to determine if the channel is currently occupied. That is, the communication device 200 can determine if another device is transmitting in the channel. In the example herein, the receiver 208 detects energy in the channel and the controller 204 makes a determination if the measured energy indicates that the channel is in use. For example, the measured energy can be compared to a threshold. Other techniques can be used depending on the circumstances.

[0026] FIG. 3 is a block diagram of an example of a UE device 300 suitable for use as each of the UE devices 12, 14, 16. In some examples, the UE device 300 is any wireless communication device, such as a mobile phone, a walkie-talkie modem, a personal digital assistant (PDA), a tablet, or a smartphone. In other examples, the UE device 300 is a Machine Type Communication (MTC) communication device or an Internet-of-Things (IOT) device. The UE devices 300, (12, 14, 16) are therefore any fixed, mobile, or portable device that performs the functions described herein. The various functions and operations of the blocks described with reference to the UE device 300 may be implemented in any number of devices, circuits, or elements. Also, two or more functional blocks may be integrated into one device, and functions described as being performed in any one device may be implemented across multiple devices.

[0027] The UE device 300 includes at least a controller 302, a transmitter 304, and a receiver 306. The controller 302 includes any combination of hardware, software, and / or firmware to perform the functions described herein and facilitate the overall functionality of the communications device. An example of a suitable controller 302 includes code executing on a microprocessor or processor array coupled to a memory. The transmitter 304 includes electronics for transmitting wireless signals. In some circumstances, the transmitter 304 may include multiple transmitters. The receiver 306 includes electronics for receiving wireless signals. In some circumstances, the receiver 306 may include multiple receivers. The receiver 306 and the transmitter 304 receive and transmit signals, respectively, through an antenna 308. The antenna 308 may include separate transmit and receive antennas. In some circumstances, the antenna 308 may include multiple transmit and receive antennas.

[0028] The transmitter 304 and receiver 306 in the example of FIG. 3 perform radio frequency (RF) processing including modulation and demodulation. Thus, the receiver 306 may include components such as a low noise amplifier (LNA) and a filter. The transmitter 304 may include a filter and an amplifier. Other components may include isolators, matching circuits, and other RF components. These components may perform the functions of the communication device in combination or cooperation with other components. The required components may depend on the particular functions required by the communication device.

[0029] The transmitter 304 includes a modulator (not shown) and the receiver 306 includes a demodulator (not shown). The modulator modulates the signal transmitted as part of the uplink signal and may apply any one of a number of modulation orders. The demodulator demodulates the downlink signal according to one of a number of modulation orders.

[0030] The UE device 300 has the capability to monitor one or more uplink channels to determine if the channel is currently occupied. That is, the UE device 300 can determine if another device is transmitting in the channel. In the example herein, the receiver 306 detects energy in the channel and the controller 302 determines if the measured energy indicates that the channel is in use. For example, the measured energy can be compared to a threshold. Other techniques can be used depending on the circumstances.

[0031] 4 is a flow chart illustrating an example of a method for contending for communications resources using preemptive reservations. The method may be performed by any device transmitting in a frequency band. In the example herein, the method is performed by a UE device operating in an NR V2X or LTE C-V2X system, such as the communications system 10 described above. Thus, the method may be performed by a second UE device 14.

[0032] In step 402, a communication resource reservation by another UE device is detected. In the example herein, the other device transmits a reservation indicator to reserve communication resources for HARQ-based data transmission.

[0033] In step 404, a preemptive reservation indicator is transmitted. The preemptive reservation indicator indicates that the same communication resources reserved for the HARQ based transmission are preemptively reserved. The preemptive reservation indicator may be transmitted either in the SCI field of the control channel or in a message of the data channel transmission.

[0034] In step 406, it is determined whether the communication resources have been released. In the example herein, the UE device determines whether an acknowledgement (ACK) has been sent to the other device in response to a successfully received transmission from the other device. The device receiving the transmission from the other device may respond with an ACK or a negative acknowledgement (NACK) if it was unable to successfully receive the transmission. In step 406, if an ACK is detected, it is determined that the communication resources have been released. If an ACK is not detected or if a negative acknowledgement (NACK) is detected, it is determined that the communication resources have not been released. If it is determined that the communication resources have been released, the method proceeds to step 408 where a signal is transmitted using the preemptively reserved communication resources. Otherwise, the method continues to step 410 where no communication resources are used for transmission.

[0035] It will be apparent that other embodiments and modifications of the present invention will occur to those skilled in the art in light of these disclosures. The above description is illustrative and not limiting. The present invention should be limited only by the claims, which include all such embodiments and modifications, when viewed in conjunction with the above specification and the accompanying drawings. Therefore, the scope of the present invention should not be determined with reference to the above description, but instead with reference to the appended claims and their full scope of equivalents.

Claims

1. 1. A method comprising: a user equipment (UE) device transmitting an indicator indicating that communication resources for sidelink transmissions are reserved by the UE device; The UE device receives a signal from another UE device, the signal being different from a resource reservation and transmitted on a predetermined resource used for feedback transmission; and refraining from transmitting the sidelink transmission using the communication resources in response to receiving the signal transmitted on the predetermined resource by the UE device. method.

2. A user equipment (UE) device, comprising: a transmitter for transmitting an indicator indicating that communication resources for sidelink transmissions are reserved by the UE device; A receiving unit that receives a signal from another UE device, the signal being different from the resource reservation and transmitted on a predetermined resource used for feedback transmission; The transmitter, in response to receiving the signal transmitted on the predetermined resource, refrains from the sidelink transmission using the communication resource. UE device.

3. A processor for controlling a user equipment (UE) device, comprising: transmitting an indicator that communication resources for sidelink transmissions are reserved by the UE device; receiving a signal from another UE device, the signal being different from the resource reservation and transmitted on a predetermined resource used for feedback transmission; and in response to receiving the signal transmitted on the predetermined resource, refraining from the sidelink transmission using the communication resource. Processor.

4. A program for controlling a user equipment (UE) device, comprising: transmitting an indicator that communication resources for sidelink transmissions are reserved by the UE device; receiving a signal from another UE device, the signal being different from the resource reservation and transmitted on a predetermined resource used for feedback transmission; and in response to receiving the signal transmitted on the predetermined resource, the UE device executes a process of refraining from the sidelink transmission using the communication resource. program.

5. A mobile communication system including a first user device and a second user device, the first user equipment transmitting an indicator indicating that communications resources for sidelink transmissions are reserved by the first user equipment; The second user equipment transmits to the first user equipment a signal that is different from the resource reservation and is transmitted on a predetermined resource used for feedback transmission; The first user equipment refrains from the sidelink transmission using the communication resources in response to receiving the signal transmitted on the predetermined resources. Mobile communication system.

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