Sidelink communications with reduced power consumption

Abstract

Example embodiments relate to sidelink communications with reduced power consumption. In one embodiment, a terminal device may include at least one processor and at least one memory containing computer program code. The at least one memory and the computer program code may be configured to: with the at least one processor, cause the terminal device to monitor sidelink transmissions during a monitoring time interval of a transmission period, and, if no sidelink transmission to the terminal device is received within the monitoring time interval, ignore a retransmission time interval following the monitoring time interval within the transmission period.

Description

Technical Field

[0001] The exemplary embodiments described herein relate generally to communication technology, and more particularly to wireless communication devices, methods, and systems for sidelink communications with reduced power consumption. Background Art

[0002] In this specification and / or drawings, certain abbreviations appearing are defined as follows:

[0003] D2D Device to Device

[0004] gNB 5G Node-B

[0005] LTE Long Term Evolution

[0006] MAC Media Access Control

[0007] NR New Radio

[0008] PS Public Safety

[0009] PSCCH Physical Sidelink Control Channel

[0010] PSFCH Physical Sidelink Feedback Channel

[0011] PSSCH Physical Sidelink Shared Channel

[0012] RLC Radio Link Control

[0013] UE User Equipment

[0014] V2X

[0015] VoIP Voice transmission based on IP

[0016] Sidelink was first introduced in 3GPP Rel.12 as a feature of LTE for device-to-device (D2D) communications, and continued to evolve in Rel.13, 14, and 15 for a variety of applications, especially vehicle-to-everything (V2X) scenarios. The first standard for NR-based sidelink was established in Rel.16, which also focused on V2X.

[0017] Recently, enhancements to the NR sidelink have been proposed for the purpose of extending the use of the NR sidelink to public safety and commercial use cases. Since the requirements and traffic characteristics of these use cases are very different from those of V2X, corresponding enhancements are required in addition to the NR V2X sidelink specified in Rel.16. For example, in public safety use cases, UEs are usually sensitive to energy consumption and require efficient energy saving mechanisms. Summary of the invention

[0018] A brief summary of exemplary embodiments is provided below to provide a basic understanding of some aspects of various embodiments. It should be noted that this summary is not intended to identify the key features of the basic elements or define the scope of the embodiments, and its only purpose is to introduce some concepts in a simple form as a prelude to the more detailed description provided below.

[0019] In a first aspect, an example embodiment of a network device is provided. The network device may include: at least one processor and at least one memory including computer program code; the at least one memory and the computer program code may be configured to, using the at least one processor, cause the network device to: configure a transmission period for sidelink communication for a terminal device. The transmission period may include a monitoring time interval for at least a first transmission of a data packet and a retransmission time interval for retransmission of the data packet after the monitoring time interval, respectively.

[0020] In a second aspect, an example embodiment of a terminal device is provided. The terminal device may include: at least one processor and at least one memory including computer program code; the at least one memory and the computer program code may be configured to, using the at least one processor, cause the terminal device to: send a first transmission of a data packet to a receiving terminal device during a monitoring time interval of a transmission cycle; and send subsequent transmissions of the data packet to the receiving terminal device during the monitoring time interval and / or a retransmission time interval after the monitoring time interval of the transmission cycle.

[0021] In a third aspect, an example embodiment of a terminal device is provided. The terminal device may include: at least one processor and at least one memory including computer program code; the at least one memory and the computer program code may be configured to, with the at least one processor, cause the terminal device to: monitor sidelink transmissions during a monitoring time interval of a transmission period; and, if no sidelink transmission to the terminal device is received during the monitoring time interval, ignore a retransmission time interval after the monitoring time interval in the transmission period.

[0022] In a fourth aspect, an example embodiment of a method implemented in a network device is provided. The method may include: configuring a transmission period for a sidelink communication for a terminal device. The transmission period may include a monitoring time interval for at least a first transmission of a data packet and a retransmission time interval for retransmission of the data packet after the monitoring time interval.

[0023] In a fifth aspect, an example embodiment of a method implemented in a terminal device is provided. The method may include: sending a first transmission of a data packet to a receiving terminal device during a monitoring time interval of a transmission cycle; and sending a subsequent transmission of the data packet to the receiving terminal device during the monitoring time interval and / or a retransmission time interval after the monitoring time interval in the transmission cycle.

[0024] In a sixth aspect, there is provided an example embodiment of a method implemented in a terminal device. The method may include: monitoring a sidelink transmission during a monitoring time interval of a transmission period; and ignoring a retransmission time interval after the monitoring time interval in the transmission period if no sidelink transmission to the terminal device is received during the monitoring time interval.

[0025] In a seventh aspect, an example embodiment of a computer program product is provided. The computer program product may be implemented in at least one computer-readable medium and include instructions. The instructions may, when executed by at least one processor in a network device, cause the network device to: configure a transmission period for sidelink communication for a terminal device. The transmission period may include a monitoring time interval for at least a first transmission of a data packet, and a retransmission time interval for retransmission of the data packet after the monitoring time interval.

[0026] In an eighth aspect, an example embodiment of a computer program product is provided. The computer program product may be implemented in at least one computer-readable medium and include instructions. The instructions may, when executed by at least one processor in a terminal device, cause the terminal device to: send a first transmission of a data packet to a receiving terminal device during a monitoring time interval of a transmission cycle; and send subsequent transmissions of the data packet to the receiving terminal device during the monitoring time interval and / or a retransmission time interval after the monitoring time interval in the transmission cycle.

[0027] In a ninth aspect, an example embodiment of a computer program product is provided. The computer program product may be implemented in at least one computer-readable medium and include instructions. The instructions, when executed by at least one processor in a terminal device, may cause the terminal device to: monitor sidelink transmissions during a monitoring time interval of a transmission period; and if no sidelink transmission to the terminal device is received during the monitoring time interval, ignore a retransmission time interval after the monitoring time interval in the transmission period.

[0028] When read in conjunction with the accompanying drawings, the accompanying drawings illustrate the principles of the exemplary embodiments of the present application; other features and advantages of the exemplary embodiments of the present application will also be apparent from the following description of the specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Some example embodiments will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

[0030] Figure 1 A schematic diagram showing an example communication system in which embodiments of the present application may be implemented;

[0031] Figure 2 An interaction diagram illustrating sidelink communication operations according to some embodiments of the present application;

[0032] Figure 3 A schematic diagram showing a sidelink configuration for a receiving terminal device according to some embodiments of the present application;

[0033] Figure 4 A schematic diagram showing a sidelink configuration for a receiving terminal device according to some embodiments of the present application;

[0034] Figure 5A , 5B and 5C show an example of resource selection for sidelink transmission according to some embodiments of the present application;

[0035] Figures 6A-6B An example of resource selection for sidelink transmission according to some embodiments of the present application is shown;

[0036] Figure 7 A flow chart showing a sidelink communication method implemented in a network device according to some embodiments of the present application;

[0037] Figure 8 A flowchart of a sidelink communication method implemented in a terminal device according to some embodiments of the present application is shown;

[0038] Fig. 9 A flowchart of a sidelink communication method implemented in a terminal device according to some embodiments of the present application is shown;

[0039] Fig.10 A schematic block diagram of a device according to some embodiments of the present application is shown.

[0040] Throughout all the drawings, the same or similar reference numerals indicate the same or similar elements, and repeated description of the same elements will be omitted. DETAILED DESCRIPTION

[0041] Some example embodiments are described in detail below with reference to the accompanying drawings. In order to provide a thorough understanding of various concepts, the following description includes specific details. However, it is apparent to those skilled in the art that these concepts can be implemented without these specific details. In some cases, in order to avoid confusion between the concepts and features described, well-known circuits, technologies and components are shown in the form of block diagrams.

[0042] As used in this application, the term "network equipment" refers to any suitable entity or device that can provide cellular or coverage, through which a terminal device can access a network or receive services. Network equipment can generally be referred to as a base station. The term "base station" used in this application may represent a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), or a gNB. A base station can be implemented as a macro base station, a relay node, or a low-power node, such as a micro base station or a femto base station. A base station can be composed of several distributed network units, such as a central unit (CU), one or more distributed units (DU), one or more remote radio heads (RRH) or remote radio units (RRU). The number and functionality of these distributed units depends on the selected separation RAN architecture.

[0043] As used in this application, the term "terminal device" or "user equipment" (UE) refers to any entity or device that can communicate wirelessly with network devices or with each other. Examples of terminal devices may include mobile phones, mobile terminals (MT), mobile stations (MS), subscriber stations (SS), portable subscriber stations (PSS), access terminals (AT), computers, wearable devices, vehicle-mounted communication devices, machine type communication (MTC) devices, D2D communication devices, V2X communication devices, sensors, etc. The term "terminal device" can be used interchangeably with UE, user terminal, mobile terminal, mobile station or wireless device.

[0044] As used in this application, the term "circuitry" may refer to one, more than one, or all of the following: (a) hardware circuit implementations only (such as implementations only in analog and / or digital circuitry); and (b) combinations of hardware circuitry and software, such as (applicable to): (i) a combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) any portion of hardware processor(s) with software (including (multiple) digital signal processors), software, and (multiple) memory(s) that work together to enable a device such as a mobile phone or server to perform various functions); and (c) hardware circuit(s) and / or processor(s) that require software (e.g., firmware) to operate, such as microprocessor(s) or a portion of microprocessor(s), but the software may not be present when not required for operation. This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover implementations of hardware circuitry or processor(s) only or a portion of a hardware circuitry or processor and its (or their) accompanying software and / or firmware. For example, and if applicable to a particular claim element, the term circuitry would also cover a baseband integrated circuit or a processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or networking device.

[0045] The term "including" and its variations should be understood as open-ended terms of "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least another embodiment". Other term-related definitions will be described in the following description.

[0046] Figure 1 FIG. 1 is a schematic diagram of an exemplary communication system 100 in which exemplary embodiments of the present application may be implemented. Figure 1, a communication system 100 as part of a communication network includes a network device 120 and a plurality of terminal devices (hereinafter referred to as "UE") 110-1, 110-2, 110-3 (collectively referred to as "UE110") in a group 130. The network device 120 and the UE 110 can communicate on an uplink (UL), a downlink (DL) and / or a supplementary uplink (SUL); and the UEs 110-1, 110-2, 110-3 can communicate with each other on a sidelink. It should be understood that the UE group 130 may include different numbers of UEs, such as 2, 4, 5 or more UEs; and the communication system 100 may include different numbers of network devices, and / or different numbers of terminal devices, and / or different numbers of UE groups. For example, the communication system 100 may include a UE group for police public safety (PS) and a UE group for firefighter PS; and the UE may belong to one or both of these groups. For sidelink communications between UEs, each UE 110 may act as a transmitting device for transmitting sidelink transmissions to other one (or more) UEs, and as a receiving device for receiving sidelink transmissions from other one (or more) UEs. Any UE 110 in group 130 may also act as a group leader for periodically transmitting and / or receiving data to group members, or group 130 may not include a group leader. For simplicity and clarity, in this document, terminal device 120 is described as a gNB, UE 110-1 is described as a transmitting UE, UE 110-2 as a receiving UE, and UE 110-3 as an additional UE, but it should be understood that the embodiments are not limited to this in any way.

[0047] It should be understood that Figure 1 As shown in , some embodiments may be implemented when UE 110 is within the coverage of network device 120; some embodiments may be implemented when UE 110 is outside the coverage of network device 120; and some embodiments may also be implemented when some of UE 110 are within the coverage of network device 120 and the rest of UE 110 are outside the coverage of network device 120.

[0048] In public safety and commercial use scenarios, UEs are generally more energy sensitive than vehicle-mounted devices. According to the power consumption model disclosed in 3GPP TR36.746, a UE in a receiving state consumes 40 to 100 times more power than a UE in a sleep or idle state. In the receiving state, the UE needs to perform blind decoding of the physical sidelink control channel (PSCCH) in each time slot of the sidelink resource pool for the UE so as not to miss any packets of interest. Blind decoding operations consume a lot of power. Therefore, it is expected to reduce inefficient blind decoding and put the UE into a sleep or idle state more often to reduce power consumption.

[0049] Figure 2 An interaction diagram for sidelink communication operations according to some embodiments of the present application is shown. Figure 2 The process shown in can reduce the power consumption of the receiving UE for sidelink communication without causing any sidelink transmission to the receiving UE to be lost. Figure 2 , at box 1, an operation of configuring a sidelink for the receiving UE 110-2 is performed. The operation may be performed at the gNB 120 as indicated by the dashed arrow 1.1, at the transmitting (Tx) UE 110-1 as indicated by the dashed arrow 1.2, at the receiving (Rx) UE 110-2 itself as indicated by the dashed box 1.3, or at the additional UE 110-3 as indicated by the dashed arrow 1.4. In some embodiments, the additional UE 110-3 may serve as a UE group leader in the group 130 including the UEs 110-1, 110-2, and 110-3. When the sidelink of the Rx UE 110-2 is configured by the Tx UE 110-1, the Rx UE 110-2 itself, or the additional UE 110-3, they may also report the sidelink configuration of the Rx UE 110-2 to the gNB 120.

[0050] In particular, in operation 1, Rx UE 110-2 may be configured with a transmission period for sidelink communication, Figure 3 An example is shown. Figure 3 , each transmission period of the sidelink communication may include a monitoring time interval in the time domain and a retransmission time interval after the monitoring time interval. The monitoring time interval may include one or more time slots for at least the first transmission of a data packet to Rx UE 110-2, and the retransmission time interval may include one or more time slots for retransmission of a data packet to Rx UE 110.2. It should be understood that the time slots for the transmission period may be selected from a resource pool allocated to Rx UE 110-2.

[0051] In some embodiments, the first m transmissions of the data packet to the Rx UE 110-2 may be sent during the monitoring time interval, and the remaining n transmissions of the data packet may be sent during the retransmission time interval, wherein m is an integer equal to or greater than 1, and n is an integer equal to or greater than zero. The numbers m and n may be configured to the Rx UE 110-2, for example, by a first parameter m and a second parameter n, respectively. The number m may be determined by the channel quality between the Tx UE 110-1 and the Rx UE 110-2. If the channel quality is good, m may have a small value; if the channel quality is poor, m may have a large value.

[0052] In some embodiments, Rx UE 110-2 may be configured to have the same monitoring time interval as other UEs in the same service group 130. For example, the UEs used by the police belong to the police public safety (PS) group, and they are configured with the same monitoring time interval (or transmission period) so that each UE in the police PS group can receive sidelink transmissions from other UEs in the group; the UEs used by the firefighters belong to the fire brigade PS group, and they are configured with the same monitoring time interval (or transmission period) so that each UE in the fire brigade PS group can receive sidelink transmissions from other UEs in the group. Since the UEs in the police PS group do not need to receive transmissions from the UEs in the fire brigade PS group, the monitoring time interval of the police PS group may not overlap with the monitoring time interval of the fire brigade PS group. In some embodiments, the same monitoring time interval may be configured for the police PS group and the fire brigade PS group to facilitate inter-departmental communications.

[0053] In some embodiments, the size of the monitoring time interval may be determined based on the transmitter density, the number m, the channel busy ratio (CBR), and / or the resource selection method. For example, if many Tx UEs transmit data to Rx UE 110-2, the number m has a large value, and / or the channel is busy, the monitoring time interval may be configured with a large value. For another example, in the case of random resource selection, the monitoring time interval may be configured with a larger value than in the case of sensing-based resource selection.

[0054] In some embodiments, the size of the transmission period can be determined based on the service provided by the sidelink communication. For example, in a public safety use scenario, the most important service that needs to be supported is VoIP (voice over IP), and the voice codec typically sends a VoIP packet every 20ms. Therefore, a suitable choice of the transmission period can be 20ms or a multiple of 20ms, such as 40ms, 60ms, etc., as long as it is shorter than the latency requirement of the sidelink communication.

[0055] Figure 4 A sidelink configuration for Rx UE 110-2 according to some embodiments of the present application is shown, wherein Figure 3 The multiple consecutive transmission cycles shown are configured as long cycles. For example, Figure 4 In the example, 5 transmission cycles are configured as long cycles, each of which includes 5 monitoring time intervals and 5 retransmission time intervals. It should be understood that more or fewer transmission cycles can be configured as long cycles, as long as the long cycle is shorter than the delay requirement of the sideline communication. For example, when the transmission cycle is 20ms, Figure 4 The size of the long period is 100 ms, which is shorter than the typical end-to-end delay requirement of VoIP service (ie, 200 ms).

[0056] The long cycle may be inactive or active. Rx UE 110-2 always monitors the first monitoring time interval of the long cycle to determine whether the long cycle is active or inactive. If no sidelink transmission is scheduled for Rx UE 110-2 in the first monitoring time interval, Rx UE 110-2 determines that the long cycle is inactive, and then it does not need to monitor subsequent monitoring time intervals in the long cycle. On the other hand, if at least one sidelink transmission is scheduled for Rx UE 110-2 in the first monitoring time interval, Rx UE 110-2 determines that the long cycle is active, and it keeps monitoring each monitoring time interval in the long cycle.

[0057] Return to reference Figure 2 , at box 2, when Tx UE 110-1 has data packets to send to Rx UE 110-2, a sidelink transmission is scheduled for Rx UE 110.2. For example, when the medium access control layer of Tx UE 110-1 receives a packet data unit (PDU) to be sent to Rx UE 110-2 from a higher layer, Tx UE 110-1 needs to schedule resources for the transmission of the data packet. In some embodiments, the sidelink transmission to Rx UE 110-2 can be scheduled by gNB 120, as shown in dashed box 2.1. For example, Tx UE 110-1 can send a scheduling request to gNB 120 to notify it that it has one or more data packets to send to Rx UE 110-2. The gNB 120 will then select available resources for the transmission of the data packet and send a scheduling grant carried in downlink control information (DCI) to Tx UE 110-1 to notify the resource selection. In some embodiments, the sidelink transmission to Rx UE 110-2 can be scheduled by the additional UE 110-3, as shown in the dashed box 2.3. Similar to gNB 120, the additional UE 110-3 can notify the Tx UE 110-1 of the resource selection carried in the PSSCH or sidelink control information (SCI). In some embodiments, the sidelink transmission to Rx UE 110-2 can be scheduled by Tx UE 110-1 itself, as shown in the dashed box 2.2. Various resource selection methods can be applied, including but not limited to random resource selection or sensing-based resource selection. For sensing-based resource selection, Tx UE 110-1 may sense the status of control and data channels used by the transmitting UE and select available resources for transmission to Rx UE 110-2.

[0058] Figure 5A , 5B5C shows an example of resource selection for sidelink transmission according to some embodiments of the present application. As described above, Rx UE 110-2 is configured for periodic monitoring and retransmission time intervals. When a data packet arrives, at least the first transmission of the data packet must be scheduled during the monitoring time interval, and subsequent transmissions of the data packet may be scheduled during the monitoring time interval and / or the retransmission time interval.

[0059] Figure 5A FIG. 1 shows a case where a data packet to Rx UE 110-2 arrives during a retransmission time interval. Figure 5A , the first two transmissions of the data packet are scheduled during the next monitoring time interval (m=2), and the subsequent two transmissions of the data packet are scheduled during the retransmission time interval corresponding to the monitoring time interval for the first two transmissions (n=2). It should be understood that four transmissions of the data packet are shown only by way of example, and more or fewer transmissions may be scheduled for the data packet. In addition, the number of transmissions (m, n) scheduled for the monitoring time interval and the retransmission time interval may also vary depending on the channel state between the Tx UE 110-1 and the Rx UE 110-2 and / or the configuration of the communication system 100. For example, if the channel between the Tx UE 110-1 and the Rx UE 110-2 has good quality, the number of transmissions (m) scheduled during the monitoring time interval may be reduced to, for example, 1, and the number of transmissions (n) scheduled during the retransmission time interval may be increased to, for example, 3. On the other hand, if the channel between Tx UE 110-1 and Rx UE 110-2 has poor quality, the number of scheduled transmissions (m) during the monitoring time interval may be increased to, for example, 3, and the number of scheduled transmissions (n) during the retransmission time interval may be decreased to, for example, 1.

[0060] It should also be understood that the four transmissions of the data packet can be scheduled one by one. For example, when Tx UE 110-1 sends the first transmission to Rx UE 110-2, Rx UE 110-2 can send a hybrid automatic repeat request (HARQ) feedback to Tx UE 110-1 on a physical sidelink feedback channel (PSFCH). If the HARQ feedback is an acknowledgment (ACK) indicating that Rx UE 110-2 has successfully received the transmission, Tx UE 110-1 will not schedule the retransmission of the data packet to Rx UE 110-2. Instead, Tx UE 110-1 will empty its HARQ buffer and start a new transmission. On the other hand, if the HARQ feedback is a negative acknowledgment (NACK) indicating that Rx UE 110-2 did not receive the transmission, Tx UE 110-1 will schedule the retransmission of the data packet to Rx UE 110-2. This process may be repeated until Rx UE 110-2 successfully receives the data packet or the number of transmissions of the data packet reaches a predetermined maximum value.

[0061] In some embodiments, resources for four transmissions may also be determined at one time. For example, gNB 120 (block 2.1), Tx UE 110-1 (block 2.2), or additional UE 110-3 (block 2.3) may select resources for four transmissions of a data packet at one time. Specifically, resources for the first two transmissions are selected from a monitoring time interval, and resources for the subsequent two transmissions are selected from a retransmission time interval corresponding to the monitoring time interval. Tx UE 110-1 will then send the four transmissions using the selected resources, and Rx UE 110-2 will send HARQ feedback to Tx UE 110-1 after the last transmission.

[0062] Figure 5B and 5C 1 shows the arrival of data packets to Rx UE 110-2 during the monitoring time interval. Figure 5B As shown, the first m transmissions of the data packet can be selected from the next monitoring time interval ( Figures 5A-5C In some embodiments, the resource of m=2) is selected instead of the resource of the current monitoring time interval. Figure 5C As shown, resources for the first m transmissions of a data packet can be selected from the current monitoring time interval. Resources for the subsequent n transmissions of a data packet ( Figures 5A-5C The resources for n=2) can be selected from the retransmission time intervals corresponding to the monitoring time intervals of the previous m transmissions. Figure 5B Compared to the example shown, Figure 5CThe example shown has a shorter latency, but it may increase the probability of transmission collisions. Therefore, sensing-based resource selection is preferred. Sensing-based resource selection can be performed to check whether there are sufficient good transmission resources in the current monitoring time interval. If not, transmission resources can be selected from the next monitoring time interval. It should also be understood that if Figures 5A-5B As shown, there are not enough good transmission resources in the next monitoring time interval, then the first m transmissions can be scheduled to the next monitoring time interval.

[0063] Figure 6A-6B Other examples of resource selection for sidelink transmission according to some embodiments of the present application are shown. Figure 6A-6B In the example of FIG. 1 , Rx UE 110-2 is configured as follows Figure 4 The long transmission cycle shown in FIG. 1 and each long cycle includes multiple Figure 3 The transmission cycle shown (such as Figure 4 , 6A -5 of 6B). Fig. 6A , when one or more data packets ( Fig. 6A 2) when an inactive long cycle arrives, wherein the first monitoring time interval of the inactive long cycle has no transmission scheduled to Rx UE 110-2, the first m transmissions of at least one of the one or more data packets are scheduled during the first monitoring time interval of the next long cycle. That is, the next long cycle will be an active long cycle. If the first monitoring time interval of the next long cycle has sufficiently good transmission resources, all one or more data packets arriving during the previous inactive long cycle can have their first m transmissions scheduled during the first monitoring time interval of the next long cycle. When a data packet to Rx UE 110-2 arrives during an active long cycle, wherein the first monitoring time interval of the active long cycle is scheduled for transmission to Rx UE 110-2, the first m transmissions of the data packet will be scheduled within the current or next available monitoring time interval, within the current long cycle or within the next long cycle. Although Fig. 6A Not shown in FIG. 1 , but each of the subsequent n transmissions of the data packet will be scheduled during a retransmission time interval corresponding to the monitoring time interval used for the previous m transmissions of the data packet.

[0064] Figure 6B It shows that the data packet has a long transmission period ( Figure 6BIn some embodiments, the first transmission of the data packet may be scheduled during the first monitoring time interval of the long transmission cycle. Therefore, the long transmission cycle becomes the activated long cycle, and Rx UE 110-2 will monitor each monitoring time interval in the activated long cycle. In some embodiments, the first transmission of the data packet may also be scheduled during the first monitoring time interval of the next long transmission cycle. Therefore, the current long transmission cycle becomes inactive, and the next long transmission cycle becomes active.

[0065] Return to reference Figure 2 , in operation 3, Tx UE 110-1 sends a data packet to Rx UE 110-2 using the resources selected in operation 2, and Rx UE 110-2 receives the sidelink transmission in operation 4. In particular, Rx UE 110-2 monitors the monitoring interval of the transmission period. For example, Rx UE 110-2 performs blind decoding of the physical sidelink control channel (PSCCH) in each time slot of the monitoring time interval, and may further attempt to decode the corresponding physical sidelink shared channel (PSSCH) based on the decoded PSCCH. If the PSCCH portion of one or more transmissions of the data packet to Rx UE 110-2 is correctly received / decoded during the monitoring time interval, and the corresponding PSSCH portion of the transmission of the data packet is not correctly received / decoded, then Rx UE 110-2 will further decode the subsequent transmission of the data packet at the resources in the corresponding retransmission time interval indicated in the previous transmission (or multiple transmissions) of the data packet. In some embodiments, if the PSCCH portion of the previous transmission (or multiple transmissions) is correctly decoded and decoding of the PSSCH portion of the previous transmission (or multiple transmissions) is not performed, the Rx UE 110-2 can decode the subsequent transmission (or multiple transmissions) of the data packet at the resources in the corresponding retransmission time interval indicated in the previous (multiple) transmissions of the data packet, and the Rx UE 110-2 can combine all transmissions to determine the data packet, thereby improving the reliability of communication. Figures 5A-5C, the previous transmission can indicate the resources of the subsequent two transmissions. Therefore, Rx UE 110-2 can directly decode the transmission in the retransmission time interval, avoiding blind decoding of each time slot in the retransmission time interval. If no transmission to Rx UE 110-2 is received in the monitoring time interval, or a transmission of a data packet to Rx UE 110-2 is received in the monitoring time interval and both the PSCCH part and the PSSCH part of the transmission are correctly decoded, then Rx UE 110-2 will ignore the retransmission time interval corresponding to the monitoring time interval. In other words, Rx UE 110-2 can be set to sleep / idle mode to turn off its receiver circuit. In this way, Rx UE 110-2 can skip receiving / decoding the entire retransmission time interval, or avoid receiving / decoding most of the time slots in the retransmission time interval. Compared to the situation of blindly decoding all time slots, Figure 2 The process allows to significantly reduce the power consumption of sidelink communications.

[0066] When Rx UE 110-2 is configured as Figure 4 In the long cycle shown, it always monitors the first monitoring time interval in each long cycle. Rx UE 110-2 turns on its receiving circuit in the first monitoring time interval of each long cycle and receives / decodes (multiple) PSCCH / PSCCH in this time interval (see Figure 4 If at least one transmission is received in the first monitoring time interval of the long cycle, Rx UE 110-2 considers the long cycle to be active and keeps monitoring each subsequent monitoring time interval in the long cycle (e.g. Figure 4 If no transmission is received in the first monitoring time interval of the long cycle, Rx UE 110-2 considers the long cycle inactive and ignores all subsequent transmission cycles in the long cycle (such as Figure 4 Because there is a lot of silence time between the talk bursts of the VoIP data traffic, this receiver mode can further reduce the power consumption of the Rx UE 110-2, and it can also meet the latency requirement of the VoIP service.

[0067] Figure 7 A flowchart of a sidelink communication method 200 implemented in a network device (e.g., gNB 120) according to some embodiments of the present application is shown. Figure 7 , the method 200 may include step S210: configuring a transmission period for the sidelink communication for the terminal device (eg, Rx UE110-2). Figure 3As discussed, the transmission period may include a monitoring time interval for at least a first transmission of a data packet to Rx UE 110-2, and a retransmission time interval following the monitoring time interval for retransmissions of the data packet.

[0068] In some embodiments, optionally, the method 200 may further include step S220: configuring parameters m and n for the Rx UE 110-2. The first parameter m indicates that the first m transmissions of the data packet to the Rx UE 110-2 will be scheduled during the monitoring time interval, and the parameter n indicates that the subsequent n transmissions of the data packet will be scheduled during the retransmission time interval after the monitoring time interval.

[0069] In some embodiments, optionally, the method 200 may further include step S230: configuring a long cycle for the Rx UE 110-2, each long cycle including the above-mentioned multiple transmission cycles.

[0070] In some embodiments, optionally, the method 200 may further include step S240: scheduling a first transmission of a data packet to the Rx UE 110-2 during a monitoring time interval of a transmission cycle, and scheduling subsequent transmissions of the data packet to the Rx UE 110-2 during a monitoring time interval and / or a retransmission time interval of the transmission cycle. For example, if the Rx UE 110-2 is configured with first and second parameters m, n, the first m transmissions of the data packet may be scheduled during the monitoring time interval, and the subsequent n transmissions of the data packet may be scheduled during a retransmission time interval after the monitoring time interval. In some embodiments, when the Rx UE 110-2 is configured with the first and second parameters m, n, the first m transmissions of the data packet may be scheduled during the monitoring time interval, and the subsequent n transmissions of the data packet may be scheduled during a retransmission time interval after the monitoring time interval. Figure 4 In the case of the long cycle shown, if a data packet arrives during an inactive long cycle, where no transmission to Rx UE 110-2 is scheduled for the first monitoring time interval of the long cycle, the first transmission of the data packet can be scheduled during the first monitoring time interval in the next long cycle. If a data packet arrives during an active long cycle, where at least one transmission to Rx UE 110-2 is scheduled during the first monitoring time interval of the long cycle, the first transmission of the data packet can be scheduled during the current or next available monitoring time interval in the current activated long cycle or the next long cycle. If a data packet arrives during the first monitoring time interval of a long transmission cycle, the first transmission of the data packet can be scheduled during the first monitoring time interval of the current long transmission cycle or during the first monitoring time interval in the next long transmission cycle. Subsequent transmissions of the data packet can be scheduled during the monitoring time interval of the first transmission and / or the retransmission time interval corresponding to the monitoring time interval.

[0071] Figure 8FIG. 1 is a flowchart of a sidelink communication method 300 implemented in a terminal device (eg, Tx UE 110-1) according to some embodiments of the present application. Figure 8 , the method 300 may optionally include step S310a: receiving a resource selection for sidelink transmission of a data packet to the Rx UE 110-2 from the gNB 120 or the additional UE 110-3, or step S310b: selecting resources for transmission of the data packet to the Rx UE 110-2. As described above, the resources for the first transmission of the data packet to the Rx UE 110-2 may be selected from the monitoring time interval of the transmission cycle; and, the resources for subsequent transmissions of the data packet to the Rx UE 110-2 may be selected from the monitoring time interval and / or subsequent retransmission time interval in the transmission cycle. In particular, when a data packet arrives during the monitoring time interval, the resources for the first transmission of the data packet may be selected from the current or next available monitoring time interval. When a data packet arrives during the retransmission time interval, the resources for the first transmission of the data packet may be selected from the next available monitoring time interval. In some embodiments, as Figure 4 In the case where the Rx UE 110-2 is configured to have a long cycle, if a data packet arrives during an inactive long cycle, wherein no transmission to the Rx UE 110-2 is scheduled during the first monitoring time interval of the long cycle, the resources for the first transmission of the data packet can be selected from the first monitoring time interval in the next long cycle. If the data packet arrives during an active long cycle, wherein at least one transmission to the Rx UE 110-2 is scheduled in the first monitoring time interval of the long cycle, the resources for the first transmission of the data packet can be selected from the current or next available monitoring time interval in the current active long cycle or the next long cycle. If the data packet arrives during the first monitoring time interval of the long transmission cycle, the resources for the first transmission of the data packet can be selected from the first monitoring time interval of the current long transmission cycle or from the first monitoring time interval in the next long transmission cycle. The resources for subsequent transmissions of the data packet can be selected from the monitoring time interval of the first transmission and / or the retransmission time interval corresponding to the monitoring time interval.

[0072] In some embodiments, before step S310b of selecting resources for transmission of data packets, method 300 may further include step S320: receiving a sidelink configuration for Rx UE 110-2 from gNB 120, Rx UE 110-2, or additional UE 110-3. As described above, the sidelink configuration for Rx UE 110-2 may include a monitoring time interval, a retransmission time interval, a transmission cycle including monitoring and retransmission time intervals, a long cycle including multiple transmission cycles, and / or parameters m, n configured for Rx UE 110-2.

[0073] Then, in step S330, a transmission of the data packet is sent to Rx UE 110-2 using the resource selection received from another device in step S310a or the resource selection determined at Tx UE 110-2 in step S310b. In particular, the first transmission of the data packet is sent during the monitoring time interval, and subsequent transmissions of the data packet are sent during the monitoring time interval and / or a retransmission time interval after the monitoring time interval.

[0074] Fig. 9 FIG. 4 is a flowchart of a sidelink communication method 400 implemented in a terminal device (eg, Rx UE 110-2) according to some embodiments of the present application. Fig. 9 , the method 400 may optionally include step S410: applying a sidelink configuration at the Rx UE 110-2. The sidelink configuration may be received from another device (e.g., the gNB 120, the Tx UE 110-1, or the additional UE 110-3), or it may be determined at the Rx UE 110-2. As described above, the sidelink configuration may include a monitoring time interval, a retransmission time interval, a transmission period including a monitoring and retransmission time interval, a long period including a plurality of transmission periods, and / or parameters m, n configured for the Rx UE 110-2.

[0075] Then, at step S420, Rx UE 110-2 monitors the sidelink transmission during the monitoring time interval of the transmission cycle. For example, Rx UE 110-2 may perform blind decoding of the sidelink control channel in each time slot of the monitoring time interval. Rx UE 110-2 may also decode the sidelink shared channel based on the decoded sidelink control channel.

[0076] If it is determined in step S430 that at least one transmission of a data packet to Rx UE 110-2 is received in a monitoring time interval and the PSCCH portion of the transmission is correctly decoded, while the corresponding PSSCH portion is not correctly decoded or the decoding of the corresponding PSSCH portion is not performed, then in step S440, Rx UE 110-2 may monitor subsequent transmissions of the data packet in a retransmission time interval after the monitoring time interval. For example, Rx UE 110-2 may directly decode the subsequent transmission using the resources indicated in the previous transmission received in the monitoring time interval. Alternatively, if Rx UE 110-2 is configured to have a long cycle, and the monitoring time interval monitored in step S420 is the first monitoring interval in the long cycle, method 400 may further include step S450: monitoring subsequent monitoring time intervals of the long cycle.

[0077] If it is determined at step S430 that the transmission to Rx UE 110-2 during the monitoring time interval is not received, or the transmission of the data packet to Rx UE 110-2 is received during the monitoring time interval and the PSCCH part and the PSSCH part of the transmission are correctly decoded, then Rx UE 110-2 will ignore the retransmission time interval after the monitoring time interval in the transmission cycle at step S460. For example, during the retransmission time interval, Rx UE 110-2 can turn off its receiver circuit to save power. Alternatively, if Rx UE 110-2 is configured to have a long cycle and the monitoring time interval monitored at step S420 is the first monitoring time interval in the long cycle, Rx UE 110-2 can also ignore subsequent transmission cycles in the long cycle. For example, during all monitoring time intervals except the first of the long cycle, and during all retransmission time intervals of the long cycle, Rx UE 110-2 can turn off its receiver circuit to save power. This will further reduce the power consumption of the sidelink communication.

[0078] Because in the discussion Figure 2 The details of the operations shown have been described herein, and methods 200, 300, and 400 are briefly described herein. Figure 2 The descriptions related to the illustrated operations also apply to methods 200 , 300 , and 400 discussed herein.

[0079] Fig.10 A schematic block diagram of a device 500 according to some embodiments of the present application is shown. The device 500 may be implemented in any one of the network device 120 or the UE 110 to perform any one of the operations and / or methods discussed above.

[0080] refer to Fig.10, the device 500 may include: one or more processors 511, one or more memories 512, and one or more transceivers 513 interconnected by one or more buses 514. The one or more buses 514 may be address, data, or control buses, and may include any interconnection mechanism, such as serial lines on a motherboard or integrated circuit, optical fibers, optical devices, or other optical communication devices. Each of the one or more transceivers 513 may include a receiver and a transmitter connected to one or more antennas 516. The device 500 may communicate wirelessly with other devices via one or more antennas 516. For example, the device 500 may be implemented in a terminal device, and it may communicate with other terminal devices on a sidelink and / or communicate with one or more network devices on an uplink and a downlink. The one or more memories 512 may include a computer program code 515. The one or more memories 512 and the computer program code 515 may be configured to, when executed by the one or more processors 511, cause the device 500 to perform the operations and / or methods described above.

[0081] The one or more processors 511 may be of any appropriate type suitable for the local technical network, and may include one or more general-purpose processors, dedicated processors, microprocessors, digital signal processors (DSPs), one or more processors based on a multi-core processor architecture, and dedicated processors such as those developed based on field programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). The one or more processors 511 may be configured to control other elements of the UE / network device and operate in cooperation with them to implement the above process.

[0082] The one or more memories 512 may include at least one storage medium in various forms, such as volatile memory and / or non-volatile memory. Volatile memory may include, but is not limited to, for example, random access memory (RAM) or cache. Non-volatile memory may include, but is not limited to, for example, read-only memory (ROM), hard disk, flash memory, etc. In addition, the one or more memories 512 may include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any combination thereof.

[0083] It should be understood that Figures 1 to 10 The present invention may be implemented in various ways, including software, hardware, firmware, or any combination thereof. In some embodiments, one or more blocks may be implemented using software and / or firmware, such as machine executable instructions stored in a storage medium. In addition to or in lieu of machine executable instructions, Figure 1-10Some or all of the blocks in the embodiment may be implemented at least in part by one or more hardware logic elements. For example, but not limited to, exemplary types of hardware logic elements that may be used include: field programmable gate array (FPGA), application specific integrated circuit (ASIC), application specific standard product (ASSP), system on chip (SOC), complex programmable logic device (CPLD), etc.

[0084] Some exemplary embodiments also provide computer program codes or instructions that, when executed by one or more processors, can cause a device or apparatus to perform the above process. The computer program code for executing the process of the exemplary embodiments can be written in any combination of one or more programming languages. The computer program code can be provided to one or more processors or controllers of a general-purpose computer, a special-purpose computer, or other programmable data processing device so that when the program code is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the computer and partially on a remote machine, or entirely on a remote machine or server.

[0085] Some exemplary embodiments also provide a computer program product implemented in a computer-readable medium including computer program code or instructions. A computer-readable medium may be any tangible medium that may contain or store a program used or associated with an instruction execution system, device, or apparatus. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium would include an electrical connection with one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0086] In addition, although the operation is described in a specific order, it should not be understood as requiring such operation to be performed in the specific order or sequence shown, or performing all illustrated operations to obtain the desired result. In some cases, multitasking and parallel processing can be advantageous. Similarly, although several specific implementation details are included in the above discussion, it should not be interpreted as limiting the scope of the application, but as a description of the features of a specific embodiment that can be specific. Some features described in the context of a single embodiment can also be combined with a single embodiment to achieve. On the contrary, the various features described in the context of a single embodiment can also be achieved individually or in any suitable sub-combination in multiple embodiments.

[0087] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims.

Claims

1. A terminal device, comprising: at least one processor; as well as at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the terminal device to: monitoring the sidelink transmission during a monitoring time interval of the transmission cycle; ignoring a retransmission time interval following the monitoring time interval within the transmission period if no sidelink transmission to the terminal device is received during the monitoring time interval; as well as monitoring subsequent transmissions of the data packets during the retransmission time interval following the monitoring time interval in the event that the control channel portion of one or more transmissions of the data packets to the terminal device during the monitoring time interval is correctly received and the corresponding data channel portion is not correctly received; Wherein, a sidelink configuration is applied in the terminal device, and the sidelink configuration indicates: a first parameter m, indicating that the first m transmissions of the data packet during the monitoring time interval are allowed to be sent to the receiving terminal device, wherein the first parameter m is an integer equal to or greater than 1; and A second parameter n indicates that subsequent n transmissions of the data packet are allowed to be sent to the terminal device during the retransmission time interval, wherein the second parameter n is an integer equal to or greater than zero.

2. The terminal device according to claim 1, wherein: Monitoring the sidelink transmission during the monitoring time interval includes performing blind decoding of the sidelink control channel during the monitoring time interval.

3. The terminal device according to claim 1, wherein: Monitoring a subsequent transmission of the data packet within the retransmission time interval includes decoding the subsequent transmission at resources indicated in a prior transmission of the data packet.

4. The terminal device according to claim 1, wherein: The at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to: In the event that no sidelink transmission to the terminal device is received within a first monitoring time interval of a long transmission cycle comprising a plurality of transmission cycles, subsequent transmission cycles within the long transmission cycle are ignored.

5. The terminal device according to claim 4, wherein: The at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to: In case one or more transmissions of data packets to the terminal device within the first monitoring time interval of the long transmission cycle are received, a subsequent monitoring time interval of the long transmission cycle is monitored.

6. The terminal device according to claim 1, wherein: The at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to: A sidelink configuration is applied at a terminal device, the sidelink configuration being determined by a network device, a sending terminal device that sends the sidelink transmission to the terminal device, an additional terminal device in sidelink communication with the terminal device, or the terminal device, and the sidelink configuration further indicating one or more of: the monitoring time interval; the retransmission time interval; the transmission period comprising the monitoring time interval and the retransmission time interval; A long transmission cycle consisting of multiple transmission cycles.

7. A method implemented in a terminal device, comprising: monitoring the sidelink transmission during a monitoring time interval of the transmission cycle; ignoring a retransmission time interval following the monitoring time interval in the transmission cycle if no sidelink transmission to the terminal device is received within the monitoring time interval; as well as monitoring subsequent transmissions of the data packets during the retransmission time interval following the monitoring time interval in the event that the control channel portion of one or more transmissions of the data packets to the terminal device during the monitoring time interval is correctly received and the corresponding data channel portion is not correctly received; Wherein, a sidelink configuration is applied in the terminal device, and the sidelink configuration indicates: a first parameter m, indicating that the first m transmissions of the data packet during the monitoring time interval are allowed to be sent to the receiving terminal device, wherein the first parameter m is an integer equal to or greater than 1; and A second parameter n indicates that subsequent n transmissions of the data packet are allowed to be sent to the terminal device during the retransmission time interval, wherein the second parameter n is an integer equal to or greater than zero.

8. The method according to claim 7, wherein: Monitoring the sidelink transmission during the monitoring time interval includes performing blind decoding of the sidelink control channel during the monitoring time interval.

9. The method according to claim 7, wherein: Monitoring a subsequent transmission of the data packet within the retransmission time interval includes decoding the subsequent transmission at resources indicated in a prior transmission of the data packet.

10. The method according to claim 7, further comprising: In the event that no sidelink transmission to the terminal device is received within a first monitoring time interval of a long transmission cycle comprising a plurality of transmission cycles, subsequent transmission cycles within the long transmission cycle are ignored.

11. The method according to claim 10, further comprising: In case one or more transmissions of data packets to the terminal device within the first monitoring time interval of the long transmission cycle are received, a subsequent monitoring time interval of the long transmission cycle is monitored.

12. The method according to claim 7, further comprising: A sidelink configuration is applied at a terminal device, the sidelink configuration being determined by a network device, a sending terminal device that sends the sidelink transmission to the terminal device, an additional terminal device in sidelink communication with the terminal device, or the terminal device, and the sidelink configuration further indicating one or more of: the monitoring time interval; the retransmission time interval; the transmission period comprising the monitoring time interval and the retransmission time interval; A long transmission cycle consisting of multiple transmission cycles.

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