WO2020257995A1

WO2020257995A1 - Method, device and computer readable medium for resource selection in v2x

Info

Publication number: WO2020257995A1
Application number: PCT/CN2019/092607
Authority: WO
Inventors: Gang Wang
Original assignee: Nec Corporation
Priority date: 2019-06-24
Filing date: 2019-06-24
Publication date: 2020-12-30

Abstract

Embodiments of the present disclosure relate to method, device and computer readable medium for resource selection in V2X. The method comprises generating sidelink control information for a transmission of data from the transmitting device to a receiving device. The sidelink control information at least indicates a reserved resource for a retransmission of the data from the transmitting device to the receiving device. The method further comprises transmitting the sidelink control information to the receiving device and in response to that a feedback indicating an unsuccessful reception of the data is not received, releasing the reserved resource. In this way, based on the sensing of the Physical Sidelink Feedback Chanel (PSFCH), it can be determined whether a reserved resource for retransmission is released for a transmission of another device, so that the effective usage of the resource could be achieved.

Description

METHOD, DEVICE AND COMPUTER READABLE MEDIUM FOR RESOURCE SELECTION IN V2X

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field of communication, and in particular, to method, device and computer readable medium for resource selection in V2X.

BACKGROUND

Device to device (D2D) /vehicle to everything (V2X) communications are enabled in 5G New Radio (NR) . A sidelink transmission via a physical sidelink control channel (PSCCH) and a physical sidelink share channel (PSSCH) have been studied to enable communication between terminal devices. In the latest development, a physical sidelink feedback channel (PSFCH) is defined to convey sidelink feedback control information (SFCI) for unicast and groupcast.

To improve transmission reliability, a HARQ mechanism has been widely used in communication systems. In HARQ, a receiver feeds back a positive acknowledgement (ACK) to a transmitter if data from the transmitter is detected correctly and a negative acknowledgement (NACK) if the data is not correctly detected. Then the transmitter may perform a retransmission if an NACK is received from the receiver. For a HARQ-based sidelink transmission, the transmitter may reserve a predetermine resource for the possible retransmission and indicate the reserved resource in the control information for the data transmission.

SUMMARY

In general, example embodiments of the present disclosure provide method, device and computer readable medium for resource selection in V2X.

In a first aspect, there is provided a method implemented at a transmitting device. The method comprises generating sidelink control information for a transmission of data from the transmitting device to a receiving device. The sidelink control information at least indicates a reserved resource for a retransmission of the data from the transmitting device to the receiving device. The method further comprises transmitting the sidelink control information to the receiving device and in response to that a feedback indicating an unsuccessful reception of the data is not received, releasing the reserved resource.

In a second aspect, there is provided a method implemented at a further transmitting device. The method comprises receiving sidelink control information from a transmitting device, the sidelink control information at least indicating a reserved resource for a retransmission of data from the transmitting device to a receiving device. The method further comprises determining the reserved resource based on the sidelink control information. The method also comprises selecting, at least based on the reserved resource, a target resource for a transmission initiated by the further transmitting device from candidate resources for resource selection.

In a third aspect, there is provided a transmitting device. The transmitting device comprises a processor; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform actions according to the first aspect.

In a fourth aspect, there is provided a further transmitting device. The a further transmitting device comprises a processor; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform actions of according to the second aspect.

In the fifth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the first aspect.

In the sixth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the second aspect.

Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

FIG. 1 is a schematic diagram of a communication environment in which some embodiments according to the present disclosure can be implemented;

FIG. 2 illustrates a flowchart of an example method in accordance with some embodiments of the present disclosure;

FIG. 3 illustrates a schematic diagram illustrating an example of reserved resource according to some embodiments of the present disclosure;

FIG. 4 illustrates a flowchart of an example method in accordance with some embodiments of the present disclosure;

FIG. 5 illustrates a schematic diagram illustrating an example of resource selection/reselection according to some embodiments of the present disclosure; and

FIG. 6 is a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

As used herein, the term “network device” or “base station” (BS) refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an Evolved NodeB (eNodeB or eNB) , a NodeB in new radio access (gNB) a Remote Radio Unit (RRU) , a radio head (RH) , a remote radio head (RRH) , a low power node such as a femto node, a pico node, and the like. For the purpose of discussion, in the following, some embodiments will be described with reference to gNB as examples of the network device.

As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of the terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, image capture devices such as digital cameras, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like.

As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.

In some examples, values, procedures, or apparatus are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

FIG. 1 shows an example communication network 100 in which embodiments of the present disclosure can be implemented. In the network 100, vehicles 110-1-110-3 and a personal mobile device 110-4 are terminal devices (collectively or individually referred to as terminal device 110) and can communicate with each other via sidelinks there between. It is to be understood that the number of terminal devices and link there between is only for the purpose of illustration without suggesting any limitations. The network 100 may include any suitable number of network devices and terminal devices adapted for implementing embodiments of the present disclosure. There may be various other terminal devices and network devices in V2X communication in many other ways.

In the following, some embodiments will be described with reference to the terminal device 110-1 and the terminal device as an example of transmitting devices (also referred as source devices) and with reference to the terminal device 110-2 as an example of a receiving device (also referred as a destination device) . For example, the terminal devices 110-1 and 110-3 may also be referred to as the “transmitting device 110-1 and 110-3” and the terminal device 110-2 may also be referred to as the “receiving device 110-2” . It is to be understood that this is merely for the purpose of discussion, without suggesting any limitations to the scope of the present disclosure.

The network 100 illustrates a scenario of V2X communication where vehicles 110-1 to 110-3 and any other devices (for example, a personal mobile device 110-4) can communicate with each other. As mentioned above, V2X communication can be divided into four types, including Vehicle-to-Vehicle (V2V) , Vehicle-to-Pedestrian (V2P) , Vehicle-to-Infrastructure (V2I) , Vehicle-to-Network (V2N) . Communication between terminal devices 110 (that is, V2V, V2P, V2I communications) can be performed via both Uu interface and direct links (or sidelinks) . For sidelink-based V2X communication, information is transmitted from a TX terminal device to one or more RX terminal devices in a broadcast manner.

Depending on the communication technologies, the network 100 may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Address (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency-Division Multiple Access (OFDMA) network, a Single Carrier-Frequency Division Multiple Access (SC-FDMA) network or any others. Communications discussed in the network 100 may use conform to any suitable standards including, but not limited to, New Radio Access (NR) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , cdma2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

As described above, a sidelink transmission via a physical sidelink control channel (PSCCH) and a physical sidelink share channel (PSSCH) have been studied to enable communication between terminal devices for Device to device (D2D) /vehicle to everything (V2X) communications. In the latest development, a physical sidelink feedback channel (PSFCH) is defined to convey sidelink feedback control information (SFCI) for unicast and groupcast.

For a HARQ-based sidelink transmission between a transmitting device 110-1 and a receiving device 110-2, the transmitting device 110-1 may reserve a predetermined resource for the possible retransmission from the transmitting device 110-1 and the receiving device 110-2 and transmitting sidelink control information including an indication of the reserved resource to the receiving device 110-2. If the sidelink transmission between a transmitting device 110-1 and a receiving device 110-2 is not successful, for example, the transmitted data has not decoded correctly by the receiving device 110-2, the receiving device 110-2 may feed HARQ-NACK back to the transmitting device 110-1. The transmitting device 110-1 then may retransmit the data on the reserved resource.

It is proposed that the reserved resource may be released if the retransmission is not required. For example, the transmitted data has decoded correctly by the receiving device 110-2. The released resource may be available for any other terminal devices for a transmission.

Other terminal device, for example, a further transmitting device 110-3, may sense the sidelink control information transmitted from the transmitting device 110-1 and determine which resource is reserved for a possible retransmission. The further transmitting device 110-3 may also sense the feedback information transmitted from the receiving device 110-2 to determine whether the reserved resource could be released.

For a HARQ-based sidelink transmission, in which condition the reserved resource will be released and how to select a resource for a transmission initiated by a further transmitting device is highly concerned.

For this propose, a method for determining whether the reserved resource will be released and a method for selecting the resource for a transmission will be discussed in the present disclosure.

Principle and example embodiments will now be described in detail below with reference to the accompanying drawings. However, those skilled in the art would readily appreciate that the detailed description given herein with respect to these drawings is for explanatory purpose as the present disclosure extends beyond theses limited embodiments.

FIG. 2 illustrates a flowchart of an example method 200 in accordance with some embodiments of the present disclosure. The method 200 can be implemented at the transmitting device 110-1 shown in FIG. 1. It is to be understood that the method 300 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard. For the purpose of discussion, the method 200 will be described with reference to FIG. 1.

As shown in FIG. 2, at block 210, the transmitting device 110-1 generates sidelink control information for a transmission of data from the transmitting device 110-1 to a receiving device 110-2. The sidelink control information may at lease indicate a reserved resource for a retransmission of the data from the transmitting device 110-1 to a receiving device 110-2.

The transmitting device 110-1 may predetermine a suitable resource reserved for a possible retransmission. If the transmitting device 110-1 receives a feedback from the receiving device 110-2 indicating the data is not received successfully or correctly, the transmitting device 110-1 may retransmit the data on the reserved resource.

At block 220, the transmitting device 110-1 transmits the sidelink control information to a receiving device 110-2, to schedule a data transmission from the transmitting device 110-1 to the receiving device 110-2. Except for the reserved resource, the control information may also comprise the indication of a resource for the receiving device 110-2 to receive the data and the indication of resource for the receiving device 110-2 to transmit the feedback for the transmission.

In a unicast mode, the transmitting device 110-1 may transmit the sidelink control information to the receiving device 110-2. In a groupcast mode, the transmitting device 110-1 may transmit the sidelink control information to the receiving device 110-2 and other receiving devices.

FIG. 3 shows a schematic diagram illustrating an example of reserved resource according to some embodiments of the present disclosure. As shown in FIG. 3, the transmitting device 110-1 may transmit the sidelink control information via a physical sidelink control channel (PSCCH) between the transmitting device 110-1 and the receiving device 110-2 at time slot S. This control information may indicate that the resource at time slot C is reserved for a possible retransmission.

Referring back to FIG. 2, at block 230, the transmitting device 110-1 may determine whether a feedback indicating an unsuccessful reception of the data is received within a predetermined time interval for the feedback. At block 240, if the transmitting device 110-1 determines that a feedback indicating an unsuccessful reception of the data is not received, the transmitting device 110-1 release the reserved resource.

For example, as shown in Fig. 3, if the transmitting device 110-1 has not received a feedback indicating an unsuccessful reception of the data before time slot D, the transmitting device 110-1 may determine the prior transmission is successful and release the reserved resource.

In some embodiments, if the transmitting device 110-1 receives a feedback indicating a successful reception of the data from the receiving device, the transmitting device 110-1 may release the reserved resource.

In some embodiments, the transmitting device 110-1 may determine whether a receiving power on a physical sidelink feedback channel between the transmitting device 110-1 and the receiving device 110-2 is lower than a threshold power. If the transmitting device 110-1 determines that the receiving power is lower than the threshold power, which may mean that no sidelink control information is received by the receiving device, the transmitting device 110-1 may release the reserved resource.

In some embodiments, the transmitting device 110-1 may transmit the sidelink control information and data in a groupcast mode. That is to say, the sidelink control information may be transmitted to a plurality of the receiving devices. For example, the transmitting device 110-1 may transmit the sidelink control information and data to the receiving device 110-2 and 110-4.

In some embodiments, only the HARQ-NACK will be fed back. In this case, if the transmitting device 110-1 has not received a feedback indicating an unsuccessful reception of the data from any receiver, the transmitting device 110-1 may release the reserved resource.

In some embodiments, also in this case, if the power measured on the PSFCH resource associated with the resource for the control information and data is lower than a specific threshold, the transmitting device 110-1 may release the reserved resource. For a possible case, if the transmitting device 110-1 determines that the receiving power is lower than the threshold power, which may mean that all receiving devices have decoded data correctly, the transmitting device 110-1 may release the reserved resource. The threshold power is configured, pre-configured or specified.

In some embodiments, both the HARQ-ACK and the HARQ-NACK will be fed back. In this case, if the first feedback and the second feedback both indicate a successful reception of the data, the transmitting device 110-1 may release the reserved resource.

For another option in a case that both the HARQ-ACK and the HARQ-NACK will be fed back, if a feedback indicating a successful reception of the data is received from one of the receiving device 110-2 and the receiving device 110-4 and no feedback is received from the other of the receiving device 110-2 and the receiving device 110-4, the transmitting device 110-1 may release the reserved resource.

In some embodiments, receiving device 110-2 feedback both the HARQ-ACK and the HARQ-NACK, and receiving device 110-4 only feedback NACK. In this case, if the transmitting device 110-1 has not received a feedback indicating an unsuccessful reception, and has received a successful reception, the transmitting device 110-1 may release the reserved resource.

It should be noted that “releasing the reserved resource” herein means the transmitting device will not retransmit the data on the reserved resource anymore and the reserved resource is changed to be an available resource.

The conditions for releasing the reserved resource have been described in detail above. According to the embodiments of the present disclosure, the released resource may be available for other transmitting device, which avoids the waste of the release resource.

For the sidelink control information transmitted in a unicast or in a groupcast mode, except from the receiving device, a further transmitting device 110-3 may also sense the sidelink control information. Thus, the further transmitting device 110-3 may aware of the reserve resource. In response to the reserved resource will be released or will not be released, as mentioned above, the further transmitting device 110-3 may also select the resource for a transmission of date initiated by the further transmitting device 110-3.

FIG. 4 illustrates a flowchart of an example method 400 in accordance with some embodiments of the present disclosure. The method 400 can be implemented at the transmitting device 110-3 shown in FIG. 1. It is to be understood that the method 400 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard. For the purpose of discussion, the method 400 will be described with reference to FIG. 1.

At block 410, the transmitting device 110-3 receives sidelink control information from the transmitting device 110-1. As described above, the sidelink control information may at least indicate a reserved resource for a retransmission of data from the transmitting device 110-1 to a receiving device 110-2.

At block 420, the transmitting device 110-3 determines the reserved resource based on the sidelink control information. By means of the sensing of PSSCH, the transmitting device 110-3 may obtain sidelink control information and aware of the reserved resource.

The transmitting device 110-3 may intend to initiate a transmission. Thus, a resource selection of the transmitting device 110-3 may be triggered and the transmitting device 110-3 may select an expected resource for this new transmission within a selection window, i.e. a predetermined set of resources. However, the resources within the selection window may be overlapped with the reserved resource. In order to avoid the collision, the transmitting device 110-3 may consider the reserved resource during the resource selection.

At block 430, the transmitting device 110-3 selects a target resource for transmission initiated by the further transmitting device from candidate resources for resource selection at least based on the reserved resource.

FIG. 5 illustrates a schematic diagram illustrating an example of resource selection/reselection according to some embodiments of the present disclosure. Taken the reserved resource in consideration, the resource selection for the transmitting device 110-3 may be discussed with reference to FIG. 5 as below.

As shown in FIG. 5, the transmitting device 110-1 may transmit, at time slot S, the sidelink control information indicating a reserved resource at time slot C. The transmitting device 110-3 may sense the sidelink control information and aware of the reserved resource.

At time slot N, the transmitting device 110-3 may intend to initiate a transmission and the resource selection/re-selection is triggered. The transmitting device 110-3 may select resource for transmission in a selection window [time slot A, time slot B] . The resource in the selection window may be referred to the candidate resources for the resource selection.

The transmitting device 110-3 may also sense the feedback for the data transmission between the transmitting device 110-1 and the receiving device 110-2 from the receiving device 110-2 and determine whether the reserved resource will be released.

In some embodiments, the transmitting device 110-3 may determine whether a feedback from the receiving device 110-2 is received until a reference time prior to the time slot A, e.g. slot A-z, where z is configured, preconfigured or specified. If the feedback is not detected by the transmitting device 110-3, the transmitting device 110-3 may not determine whether the reserved resource will be released.

In this case, as an option, the reserved resource may be precluded from the selection window [time slot A, time slot B] . That is, the transmitting device 110-3 may select the target resource from the candidate resources excluding the reserved resource. For example, as shown in FIG. 5, the transmitting device 110-3 may select time slot R for transmission as a target resource.

However, before the time slot R selected by the transmitting device 110-3 and the time slot C reserved by the transmitting device 110-1, e.g. before slot min (c-x, r-y) , where x and y are configured, preconfigured or specified the transmitting device 110-3 may sense the feedback from the receiving device 110-2 and aware of a release of the reserved resource. The transmitting device 110-3 may reselect the resource from the selection window.

In some embodiments, the transmitting device 110-3 may determine whether an estimated receiving power of the target resource is higher than an estimated receiving power of another resource which is overlapping with the reserved resource. For example, the transmitting device 110-1 may estimate the Sidelink-Reference Signal Strength Indicator/Sidelink-Reference Signal Receiving Power based on sensing. If the transmitting device 110-3 determines the receiving power of the target resource is higher than the receiving power of the other resource, the transmitting device 110-3 may reselect the other resource as the target resource.

In some embodiments, the transmitting device 110-3 may determine that the reserved resource is release based on the sensed feedback from the receiving device 110-2.

In some embodiments, for the case of unicast mode as mentioned above, if the transmitting device 110-3 receives a feedback indicating a successful reception of the data from the receiving device 110-2, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, also in this cast, the transmitting device 110-3 may determine whether a receiving power on a physical sidelink feedback channel between the transmitting device 110-1 and the receiving device 110-2 is lower than a threshold power. If the transmitting device 110-3 determines that the receiving power is lower than the threshold power, which may mean that no sidelink control information is received by the receiving device 110-2, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, for the case of the groupcast mode as mentioned above and only the HARQ-NACK will be fed back, if the transmitting device 110-3 has not received a feedback indicating an unsuccessful reception of the data from any receiver, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, also in this case, if the power measured on the PSFCH resource associated with the reserved resource is lower than a specific threshold, the transmitting device 110-3 may determine a release of the reserved resource. The specific threshold is configured, pre-configured or specified.

For the case that both the HARQ-ACK and the HARQ-NACK will be fed back, if the first feedback and the second feedback both indicate a successful reception of the data, the transmitting device 110-3 may determine a release of the reserved resource.

For another option in a case that both the HARQ-ACK and the HARQ-NACK will be fed back, if a feedback indicating a successful reception of the data is received from one of the receiving device 110-2 and the receiving device 110-4 and no feedback is received from the other of the receiving device 110-2 and the receiving device 110-4, the transmitting device 110-3 may determine a release of the reserved resource.

For the case that receiving device 110-2 feedback both the HARQ-ACK and the HARQ-NACK, and receiving device 110-4 only feedback NACK, if no feedback indicating an unsuccessful reception is detected, and a successful reception is detected, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, as another option, if the feedback is not detected by the transmitting device 110-3, the transmitting device 110-3 may select the target resource from the candidate resources regardless of whether the reserved resource is released. That is, the transmitting device 110-3 may select a resource overlapping with the target resource from the selection window [time slot A, time slot B] . For example, as shown in FIG. 5, the transmitting device 110-3 may select a resource overlapping with the reserved resource in time slot C for transmission as a target resource.

However, before the time slot C selected by the transmitting device 110-3, the transmitting device 110-3 may sense the feedback from the receiving device 110-2 and realize that the reserved resource is not released. The transmitting device 110-3 may reselect the resource from the selection window excluding the reserved resource after slot f, e.g. not later than slot f+z.

The transmitting device 110-3 may determine that the reserved resource is not released based on the following cases.

In some embodiments, for the case of unicast as mentioned above, if the transmitting device 110-3 receives a feedback from the receiving device 110-2 indicating an unsuccessful reception of the data, or if the transmitting device 110-3 determines the receiving power on the sidelink feedback channel between the transmitting device 110-1 and the receiving device 110-2 is lower than a threshold power, the transmitting device 110-3 may determine that the reserved resource is not released.

In some embodiments, for the case of the groupcast mode as mentioned above and only the HARQ-NACK will be fed back, if the transmitting device 110-3 receives a feedback indicating an unsuccessful reception of the data from any receiver, the transmitting device 110-3 may determine that the reserved resource is not released. In some embodiments, for the case that both the HARQ-ACK and the HARQ-NACK will be fed back, if the transmitting device 110-3 receives a feedback indicating an unsuccessful reception of the data from either receiving device 110-2 or the receiving device 110-4, or if the transmitting device 110-3 determines the receiving power on the sidelink feedback channel between the transmitting device 110-1 and at least one receiving device is lower than a threshold power, the transmitting device 110-3 may determine that the reserved resource is not released.

In some embodiments, if the feedback is not detected by the transmitting device 110-3, the transmitting device 110-3 may determine whether a first priority of the data to be retransmitted is lower than a second priority of data to be transmitted by the transmitting device 110-3. If the transmitting device 110-3 determines that the first priority is lower than the second priority, the transmitting device 110-3 may select the target resource from the candidate resources regardless of whether the reserved resource is released. The transmitting device 110-3 may further transmit a message indicating the selected target resource to other devices. This message indicating the selected target resource may be also referred to a reservation signaling.

As an option, if the transmitting device 110-1 detected a reservation signaling before the time slot C, e.g. not later than C-k, and the indicated resource overlapping with the reserved resource, the transmitting device 110-1 may release the reserved resource. The value of k is configured or pre-configured, and the value of k can be a function of the priority and/or delay budget of the data to be transmitted by the device 110-1.

In some embodiments, if the feedback is detected by the transmitting device 110-3 before a reference time prior to the time slot A, that is, the transmitting device 110-3 may determine whether the reserved resource is release, the transmitting device 110-3 may select the target resource from the selection window [time slot A, time slot B] excluding the reserved resource or including the reserved resource depending on whether the reserved resource is released.

In some embodiments, in case of unicast as mentioned above, if the transmitting device 110-3 receives a feedback indicating a successful reception of the data from the receiving device 110-2, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, the transmitting device 110-3 may determine whether a receiving power on a physical sidelink feedback channel between the transmitting device 110-1 and the receiving device 110-2 is lower than a threshold power. If the transmitting device 110-3 determines that the receiving power is lower than the threshold power, which may mean that no sidelink control information is received by the receiving device 110-2, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, for the case of the groupcast mode as mentioned above and only the HARQ-NACK will be fed back, if the transmitting device 110-3 has not received a feedback indicating an unsuccessful reception of the data from any receiving device, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, also in this case, if the receiving power on a physical sidelink feedback channel associated with the reserved resource is lower than the threshold power, the transmitting device 110-3 may determine a release of the reserved resource.

In some embodiments, in case of unicast as mentioned above, if the transmitting device 110-3 receives a feedback from the receiving device 110-2 indicating an unsuccessful reception of the data, or if the transmitting device 110-3 determines the receiving power on the sidelink feedback channel between the transmitting device 110-1 and the receiving device 110-2 is lower than a threshold power, the transmitting device 110-3 may determine that the reserved resource is not released. The threshold power is configured, pre-configured or specified.

In some embodiments, for the case of the groupcast mode as mentioned above and only the HARQ-NACK will be fed back, if the transmitting device 110-3 receives a feedback indicating an unsuccessful reception of the data from any receiving device, the transmitting device 110-3 may determine that the reserved resource is not released. In some embodiments, also for this case, if the power measured on the PSFCH resource associated with the reserved resource is higher than a specific threshold, the transmitting device 110-3 may determine that the reserved resource is not released. The specific threshold is configured, pre-configured or specified.

In some embodiments, for the case that both the HARQ-ACK and the HARQ-NACK will be fed back, if the transmitting device 110-3 receives a feedback indicating an unsuccessful reception of the data from either receiving device 110-2 or the receiving device 110-4, or if the transmitting device 110-3 detects a feedback indicating a successful reception of the data is received from one of the receiving device 110-2 and the receiving device 110-4, and no feedback is received from the other of the first receiving device 110-2 and the second receiving device 110-4, the transmitting device 110-3 may determine that the reserved resource is not released.

In some embodiments, if the feedback is detected by the transmitting device 110-3 and the transmitting device 110-3 may determine that the reserved resource is not released, the transmitting device 110-3 may determine whether a first priority of the data to be retransmitted by the transmitting device 110-1 is lower than a second priority of data to be transmitted by the transmitting device 110-3. If the transmitting device 110-3 determines that the first priority is lower than the second priority, the transmitting device 110-3 may select the target resource from the candidate resources with the reserved resource included. The transmitting device 110-3 may further transmit a reservation signaling to indicate the selected target resource to other devices.

In this way, the resource could be used effectively without collision. Based on the sensing of the Physical Sidelink Feedback Chanel (PSFCH) , it can be determined whether a reserved resource for retransmission is released for a transmission of another device, so that the effective usage of the resource could be achieved.

FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 can be considered as a further example implementation of the terminal device 110 as shown in FIG. 1. Accordingly, the device 600 can be implemented at or as at least a part of the terminal device 110.

As shown, the device 600 includes a processor 610, a memory 620 coupled to the processor 610, a suitable transmitter (TX) and receiver (RX) 640 coupled to the processor 610, and a communication interface coupled to the TX/RX 640. The memory 610 stores at least a part of a program 630. The TX/RX 640 is for bidirectional communications. The TX/RX 640 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the eNB, Un interface for communication between the eNB and a relay node (RN) , or Uu interface for communication between the eNB and a terminal device.

The program 630 is assumed to include program instructions that, when executed by the associated processor 610, enable the device 600 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to FIGs. 2-5. The embodiments herein may be implemented by computer software executable by the processor 610 of the device 600, or by hardware, or by a combination of software and hardware. The processor 610 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 610 and memory 610 may form processing means 650 adapted to implement various embodiments of the present disclosure.

The memory 610 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 610 is shown in the device 600, there may be several physically distinct memory modules in the device 600. The processor 610 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to FIG. 2. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, 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 disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A method implemented at a transmitting device comprising:

generating sidelink control information for a transmission of data from the transmitting device to a receiving device, the sidelink control information at least indicating a reserved resource for a retransmission of the data from the transmitting device to the receiving device;

transmitting the sidelink control information to the receiving device; and

in response to that a feedback indicating an unsuccessful reception of the data is not received, releasing the reserved resource.
The method of Claim 1, wherein releasing the reserved resource comprises:

receiving a feedback for the transmission from the receiving device; and

in response to determining the feedback indicating a successful reception of the data, releasing the reserved resource.
The method of Claim 1, wherein releasing the reserved resource comprises:

in response to that no feedback for the transmission is received in a preconfigured time interval after starting the transmission, releasing the reserved resource.
The method of Claim 3, further comprising:

determining whether a receiving power on a sidelink feedback channel between the transmitting device and the receiving device is lower than a threshold power; and

in response to determining that the receiving power is lower than the threshold power, determining that no feedback for the transmission is received.
The method of Claim 1, wherein the receiving device comprises a plurality of receiving devices, and wherein releasing the reserved resource comprises:

in response to that a feedback indicating an unsuccessful reception of the data is received from none of the plurality of receiving devices, releasing the reserved resource.
The method of Claim 1, wherein the receiving device comprises a plurality of receiving devices, and wherein releasing the reserved resource comprises:

in response to determining that a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is lower than a threshold power and a feedback indicating an unsuccessful reception of the data is received from none of the other of the plurality of receiving devices, releasing the reserved resource.
The method of Claim 1, wherein the receiving device comprises a plurality of receiving devices, and wherein releasing the reserved resource comprises:

in response to determining that a feedback indicating a successful reception of the data is received from each of the receiving devices, releasing the reserved resource.
The method of Claim 1, wherein the receiving device comprises a plurality of receiving devices, and wherein releasing the reserved resource comprises:

in response to determining that a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is lower than a threshold power and a feedback indicating a successful reception of the data is received from the other of the plurality of receiving devices, releasing the reserved resource.
The method of Claim 1, wherein the transmitting device is a terminal device and the receiving device is a terminal device.
A method implemented at a further transmitting device comprising:

receiving sidelink control information from a transmitting device, the sidelink control information at least indicating a reserved resource for a retransmission of data from the transmitting device to a receiving device;

determining the reserved resource based on the sidelink control information; and

selecting, at least based on the reserved resource, a target resource for transmission initiated by the further transmitting device from candidate resources for resource selection.
The method of Claim 10, wherein determining the target resource comprises:

in response to the resource selection is triggered, determining whether a feedback from the receiving device is received until a first reference time point prior to an initial time point of the candidate resources; and

in response to that a feedback is not received, selecting the target resource from the candidate resources excluding the reserved resource.
The method of Claim 11, further comprising:

in response to determining that the reserved resource is release at a second reference time point prior to an initial time point of the reserved resource or an initial time point of the target resource, determining whether a first receiving power of the target resource is higher than a second receiving power associated with the reserved resource; and

in response to determining that the first receiving power is higher than the second receiving power, reselecting the reserved resource as the target resource.
The method of Claim 12, further comprising:

determining that the reserved resource is release at the second reference time point in response to that at least one of the following:

a feedback from the receiving device indicating a successful reception of the data is received; and

a receiving power on a sidelink feedback channel between the transmitting device and the receiving device is lower than a threshold power.
The method of Claim 12, wherein the receiving device comprises a plurality of receiving devices, and the method further comprising:

determining that the reserved resource is release at the second reference time point in response to that at least one of the following:

a feedback indicating an unsuccessful reception of the data is received from none of the plurality of receiving devices;

a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is lower than a threshold power and a feedback indicating an unsuccessful reception of the data is received from none of the other of the plurality of receiving devices;

a feedback indicating a successful reception of the data is received from each of the receiving devices; and

a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is lower than a threshold power and a feedback indicating a successful reception of the data is received from the other of the plurality of receiving devices.
The method of Claim 10, wherein determining the target resource comprises:

in response to the resource selection is triggered, determining whether a feedback from the receiving device is received until a first reference time point prior to an initial time point of the candidate resources; and

in response to that a feedback is not received, selecting the target resource from the candidate resources including the reserved resource.
The method of Claim 15, further comprising:

in response to determining that the reserved resource is not release at a third reference time point posterior to a feedback time point of the receiving device, reselecting the target resource from the candidate resources excluding the reserved resource.
The method of Claim 16, further comprising:

determining that the reserved resource is not released at the third reference time point in response to that at least one of the following:

a feedback from the receiving device indicating an unsuccessful reception of the data is received; and

a receiving power on a sidelink feedback channel between the transmitting device and the receiving device is lower than a threshold power.
The method of Claim 16, wherein the receiving device comprises a plurality of receiving devices, and the method further comprising:

determining that the reserved resource is not release at the third reference time point in response to that at least one of the following:

a feedback indicating an unsuccessful reception of the data is received from one of the plurality of receiving devices; and

a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is higher than a threshold power and a feedback indicating a successful reception of the data is received from the other of the plurality of receiving devices.
The method of Claim 10, wherein determining the target resource comprises:

in response to the resource selection is triggered, determining whether a feedback from the receiving device is received until a first reference time point prior to an initial time point of the candidate resources;

in response to that a feedback is not received, determining whether a first priority of the data to be retransmitted is lower than a second priority of data to be transmitted by the further transmitting device;

in response to determining that the first priority is lower than the second priority, transmitting, to the transmitting device, a message indicating the reserved resource is not reserved for the transmitting device; and

selecting the target resource from the candidate resources including the reserved resource.
The method of Claim 10, wherein determining the target resource comprises:

in response to the resource selection is triggered, selecting the target resource from the candidate resources excluding the reserved resource in response to that that at least one of the following:

a feedback from the receiving device indicating an unsuccessful reception of the data is received no later than a first reference time point prior to an initial time point of the candidate resources; and

a receiving power on a sidelink feedback channel between the transmitting device and the receiving device is lower than a threshold power.
The method of Claim 10, wherein determining the target resource comprises:

in response to the resource selection is triggered, selecting the target resource from the candidate resources including the reserved resource in response to that that at least one of the following:

a feedback from the receiving device indicating a successful reception of the data is received; and

a receiving power on a sidelink feedback channel between the transmitting device and the receiving device is lower than a threshold power.
The method of Claim 10, wherein the receiving device comprises a plurality of receiving devices, and wherein determining the target resource comprises:

selecting the target resource from the candidate resources excluding the reserved resource in response to that that at least one of the following:

a feedback indicating an unsuccessful reception of the data is received from one of the plurality of receiving devices; and

a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is higher than a threshold power and a feedback indicating a successful reception of the data is received from the other of the plurality of receiving devices.
The method of Claim 10, wherein the receiving device comprises a plurality of receiving devices, and wherein determining the target resource comprises:

selecting the target resource from the candidate resources including the reserved resource in response to that that at least one of the following:

a feedback indicating an unsuccessful reception of the data is received from none of the plurality of receiving devices;

a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is lower than a threshold power and a feedback indicating an unsuccessful reception of the data is received from none of the other of the plurality of receiving devices;

a feedback indicating a successful reception of the data is received from each of the receiving devices; and

a receiving power on a sidelink feedback channel between the transmitting device and one of the plurality of receiving devices is lower than a threshold power and a feedback indicating a successful reception of the data is received from the other of the plurality of receiving devices.
The method of Claim 10, wherein the transmitting device is a terminal device, the receiving device is a terminal device and a further transmitting device is a terminal device.
A transmitting device, comprising:

a processor; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the transmitting device to perform the method according to any of claims 1-9.
A further transmitting device, comprising:

a processor; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the further transmitting device to perform the method according to any of claim 10-24.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 1-9.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claim 10-24.