Resource reservation

Abstract

An apparatus determines a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations 310, and a resource reservation period, or a time offset between a first transmission associated with a transport block (TB) and at least one second transmission associated with the TB, is selected to be an integer multiple of the monitoring period 320. The plurality of receive configurations comprise at least one of a plurality of beams, a plurality of antennas or a plurality of carriers. Other aspects of the invention include determining a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations 420. At least the first receiver configuration and the second receiver configuration are used for sequential monitoring of the sidelink resource pool according to the monitoring pattern.

Description

FIELDS

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to apparatuses, methods, and computer readable storage medium for resource reservation. BACKGROUND

[0002] In the 3rd Generation Partnership Project (3GPP) Release 18 (Rei-18) work item on NR sidelink evolution, an enhanced sidelink (SL) operation is studied on frequency range 2 (FR2) licensed spectrum. The study is limited to the support of sidelink beam management (including initial beam-pairing, beam maintenance, and beam failure recovery, and / or the like) by reusing an existing sidelink Channel State Information (CSI) framework and reusing Uu beam management concepts wherever possible. The beam management in a FR2 licensed spectrum considers a sidelink unicast communication only.

[0003] For resource allocation with beamformed transmission and reception, in sidelink operations on FR2, the beamformed transmission and reception may have impact on sidelink resource allocation. The sidelink resource allocation scheme may be enhanced for FR2 operations. Thus, sidelink resource allocation with beamformed transmission and reception (in particular resource allocation mode 2) is an open issue. SUMMARY

[0004] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: determine a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; and perform at least one of: selecting a resource reservation period to be an integer multiple of the monitoring period, or selecting a time offset between a first transmission associated with a transport block (TB) and at least one second transmission associated with the TB to be an integer multiple of the monitoring period, where the plurality of receiver configurations comprise at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0005] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; determine a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; and use at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern, where the plurality of receiver configurations comprise at least one of a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0006] In a third aspect of the present disclosure, there is provided a method. The method comprises: determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; and performing at least one of: selecting a resource reservation period to be an integer multiple of the monitoring period, or selecting a time offset between a first transmission associated with a TB and at least one second transmission associated with the TB to be an integer multiple of the monitoring period, where the plurality of receiver configurations comprise at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0007] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; determining a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; and use at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern, where the plurality of receiver configurations comprise at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0008] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; and means for performing at least one of: selecting a resource reservation period to be an integer multiple of the monitoring period, or selecting a time offset between a first transmission associated with a TB and at least one second transmission associated with the TB to be an integer multiple of the monitoring period, where the plurality of receiver configurations comprise at least one of a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0009] In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; means for determining a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; and use at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern, where the plurality of receiver configurations comprise at least one of a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0010] In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect or the fourth aspect.

[0011] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, noris it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0013] FIG. 1 illustrates an example scenario of overlapping resource reservations;

[0014] FIG. 2 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0015] FIG. 3 illustrates a flowchart of an example method implemented at the first apparatus in accordance with some example embodiments of the present disclosure;

[0016] FIG. 4 illustrates a flowchart of an example method implemented at the second apparatus in accordance with some example embodiments of the present disclosure;

[0017] FIG. 5 illustrates a flowchart of an example process of SL resource reservation in accordance with some example embodiments of the present disclosure;

[0018] FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0019] FIG. 7 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0020] Throughout the drawings, the same or similar reference numerals represent the same or similar element. DETAILED DESCRIPTION

[0021] 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 limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0022] 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.

[0023] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0024] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0025] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0026] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. 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. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0028] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0029] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0030] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, 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), the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0031] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0032] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0033] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0034] In 3GPP Release 17 (Rel-17), inter-UE coordination (IUC) scheme 2 was standardized as part of latency and reliability enhancements for SL resource allocation mode 2 (also referred to as “UE autonomous resource selection” in the 3GPP specifications). FIG. 1 illustrates an example scenario 100 of overlapping resource reservations. As shown in FIG. 1, a transmitter UE (Bl) 120 and a transmitter UE (B2) 130 may both transmit sidelink control information (SCI) to a receiver UE (A) 110 to reserve resources in slot 6 140. Therefore, there is a resource overlap 142. The receiver UE (A) 110 may detect the overlapping resource reservations by these two transmitter UEs and transmit a physical sidelink feedback channel (PSFCH) 144 indicating the presence of an expected or potential resource conflict before the conflict occurs so that one of these two transmitter UEs 120 and 130 may reselect a time-frequency resource.

[0035] In Rel-17, a UE is assumed to use an omnidirectional antenna when it performs sensing (i.e. physical sidelink control channel (PSCCH) decoding and associated reference signal received power (RSRP) measurement, as described in clause 8.1.4 of 3GPP TS 38.214). When non-omnidirectional transmission and / or reception (e.g., beamforming) is introduced in SL for operation in FR2 spectrum, it may not be possible for a UE to monitor more than one beam at a time (i.e., in a given slot). The inability to monitor more than one beam at a time may result in many non-monitored slots for a given beam. For example, if a UE monitors beam ao in even slots and beam ai in odd slots, then half of the slots are non-monitored for each beam. This may result in a potential resource conflict for a given beam not being detected by a receiver UE and thus the undetected resource conflict may impact PSCCH and physical sidelink shared channel (PSSCH) reception at the receiver UE on the given beam. In addition, this may result in resource over-exclusion, for example, in step 5 of the standard resource selection procedure as specified in clause 8.1.4 of 3GPP TS 38.214.

[0036] Example embodiments of the present disclosure propose a solution for resource reservation. With this solution, a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations is determined by a first apparatus. Then, the first apparatus selects a resource reservation period to be an integer multiple of the monitoring period and / or selects a time offset between a first transmission associated with a transport block (TB) and at least one second transmission associated with the TB to be an integer multiple of the monitoring period. In addition, a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations is determined by a second apparatus. A periodic monitoring pattern based on the monitoring period is determined by the second apparatus and the monitoring pattern is associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations. Then, the second apparatus uses at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern.

[0037] By determining a monitoring period and a periodic monitoring pattern, the first apparatus and the second apparatus are allowed to use sensing and IUC to effectively protect receptions on their receiver configurations (e.g., beams, carriers, antennas, and / or the like). In this way, resource conflict detection (i.e., collision avoidance) may be improved, for example, in SL resource allocation mode 2 when operating in FR2 with beamformed PSCCH and PSSCH transmission and reception.

[0038] It is to be noted that although the issue is originating from SL resource allocation mode 2 in FR2, the proposed scheme herein may be applied in general for different resource allocation modes and may also be applied in general for different frequency ranges.

[0039] FIG. 2 illustrates an example communication environment 200 in which example embodiments of the present disclosure can be implemented.

[0040] The communication environment 200 includes a first apparatus 210, a second apparatus 220, a third apparatus 230 and a fourth apparatus 240 which may operate as terminal devices such as UEs. In a vehicle-to-everything (V2X) scenario, these apparatuses may be installed on vehicles. In addition, these apparatuses may communicate with each other via SL communication.

[0041] Communications in the communication environment 200 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0042] It is to be understood that the number and types of apparatuses are shown in FIG. 2 for the purpose of illustration without suggesting any limitation. For example, the communication environment 200 may comprise any number and type of apparatuses.

[0043] In some example embodiments, the first apparatus 210, the third apparatus 230 and the fourth apparatus 240 may operate as transmitters. The second apparatus 220 may operate as a receiver. As shown in FIG. 2, the second apparatus 220 may use a first beam 250 and a second beam 260 to receive PSCCH / PSSCH from the first apparatus 210 and the third apparatus 230 (e.g., in resources ro 270 and ri 280, respectively). If the second apparatus 220 is not capable of monitoring both the beams 250 and 260 at a time, it may monitor the first beam 250 in some slots (e.g., even slots) and monitor the second beam 260 in other slots (e.g., odd slots).

[0044] In an example, the fourth apparatus 240 may send a sidelink control information (SCI) reserving a resource n 290 that overlaps with n 280 and may thus impact PSCCH / PSSCH reception at the second apparatus 220. If the SCI happens to be transmitted in a slot in which the second apparatus 220 is not monitoring the second beam 260 (e.g., an even slot), the potential resource conflict between n 280 and r2 290 may not be detected by the second apparatus 220, which may impact PSCCH / PSSCH reception at the second apparatus 220 on the given beam.

[0045] In various example embodiments of the present disclosure, a beam monitoring period (denoted by N), which may be (pre)configurable, is introduced for periodic monitoring of a sidelink resource pool (RP) using a fixed or same beam. Resource reservation is constrained by allowing a resource reservation period and / or a time offset between a plurality of transmissions associated with a TB (for example, including a time offset between SCI and a resource indicated by that SCI and a time offset between the first transmission and the retransmission) to take values that are an integer multiple of N. Some example implementations will be described below with reference to FIGS. 3 to 5.

[0046] FIG. 3 shows a flowchart of an example method 300 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of illustration, the method 300 will be described from the perspective of the first apparatus 210 in FIG. 2.

[0047] At block 310, the first apparatus 210 determines a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations.

[0048] In an example, the first apparatus 210 may be a transmitter UE. The plurality of receiver configurations may include at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers, which may be available for monitoring the SL resource pool (RP). Although the example embodiments of the present disclosure described below refer to beams (i.e., beam monitoring period, beam monitoring pattern, etc.), the present disclosure may be applied in other contexts, such as when multiple carriers need to be monitored by a UE but they cannot be monitored simultaneously, e.g., in sidelink carrier aggregation (SL CA). The following will explain the solution provided by example embodiments of the present disclosure in conjunction with beams as an example of receiver configurations. It can be understood that the solution provided by the present disclosure will be similarly applied to other receiver configurations, such as antennas, carriers, etc.

[0049] In some example embodiments, the monitoring period may be configured by a network or pre-configured for the sidelink resource pool. The monitoring period may be an integer, such as 3, 4, 5, etc. The monitoring period may be configured by a cellular network or preconfigured at the time of manufacturing the first apparatus 210. For example, a beam monitoring period may be configured or pre-configured by a new RRC parameter (e.g., sl-beamMonitoringPeriod) indicating the number of logical slots of the RP between monitored slots on each beam. In this way, all UEs using the RP have a consensus of the monitoring period. In other examples, after determining the monitoring period, the first apparatus 210 may notify the monitoring period to other UEs.

[0050] The (pre)configured beam monitoring period may result in an upper bound on the number of beams that may be monitored by a UE in a time division multiplexing (TDM) fashion. For example, if the beam monitoring period is 4, up to 4 beams may be monitored by a UE periodically (every 4 slots). In order to allow for a larger number of monitored beams, the beam monitoring period may be (pre)configured to a larger value (e.g., 8). However, the larger value of the beam monitoring period may result in a larger resource reservation gap (i.e., an SCI may only reserve a resource that is a multiple of 8 slots after the SCI is transmitted), which may increase latency (e.g., if multiple re-transmissions of a TB are needed for successful reception). Therefore, the (pre)configuration of the beam monitoring period may need to balance user requirements.

[0051] At block 320, the first apparatus 210 performs at least one of: selecting a resource reservation period to be an integer multiple of the monitoring period, or selecting a time offset between a first transmission associated with a TB and at least one second transmission associated with the TB to be an integer multiple of the monitoring period.

[0052] In an example, the first apparatus 210 may re-transmit a same transport block (TB) based on HARQ feedback (e.g., Acknowledgment or Negative Acknowledgment). When performing resource selection for multiple transmissions (i.e., initial transmission and retransmissions) of the TB, the first apparatus 210 may be constrained to select resources that are spaced by a multiple of the (pre)configured beam monitoring period. In this way, it may be ensured that the intended receiver of the TB may monitor the same beam for the multiple transmissions. For example, the monitoring period is N, the time offset (ti, t2) between the initial transmission and the retransmission may be allowed to take values that are an integer multiple of N (i.e., N, 2N, 3N, 4N, etc.).

[0053] In an example, if the parameter sl-MaxNumPerReserve is equal to 3, i.e., one SCI can reserve up to two future transmissions of the same TB in addition to indicating the transmission in the same slot. The resource reservation gap constraint may be relaxed by applying the constraint to the time gap between every other transmission of the TB instead of every transmission of the TB. To be specific, assuming the ith transmission of the TB takes place in slot Si, the resource reservation gap constraint becomesSi+2 “Sj — m*N instead of Si+1 - Si = m*N, where m is an integer and N is the monitoring period (e.g., 8). For example, a first SCI transmitted in slot so = n may reserve future transmissions (of the same TB) in slots si = n+3 and S2 = n+8 (gap of N slots relative to the first SCI), a second SCI transmitted in slot si = n+3 may reserve future transmissions (of the same TB) in slots S2 = n+8 and S3 = n+11 (gap of N slots relative to the second SCI) and a third SCI transmitted in slot S2 = n+8 may reserve future transmissions (of the same TB) in slots S3 = n+11 and S4 = n+16 (gap of N slots relative to the third SCI). In this way, it is ensured that every transmission (except for the first two) is reserved by an SCI that is N slots before the reserved transmission, and thus the reservation can be detected by a receiver UE requiring the full beam monitoring period N.

[0054] In another example, for periodic traffic, the first apparatus 210 may select a resource reservation period. If the monitoring period is N, the first apparatus 210 may be constrained to select a resource reservation period (P’rsvp tx) that is an integer multiple of N(i.e.,N, 2N, 3N, 4N, etc.).

[0055] In some example embodiments, after selecting the resource reservation period and / or the time offset, the first apparatus 210 may transmit control information indicating the resource reservation period and / or the time offset as an integer multiplier corresponding to the integer multiple of the monitoring period. The “Resource reservation period” and / or “Time resource assignment” fields in SCI format 1-A may be reinterpreted to indicate the resource reservation period and / or the time offset as an integer multiplier(s) corresponding to the integer multiple(s) of the monitoring period. For example, if the monitoring period is 4 and the time offset 12, the first apparatus may transmit the control information indicating that the time offset as 3 (i.e., 12 / 4). In this way, the code points which are not allowed to indicate resource reservation time gaps may be reused, and thus these code points are not wasted, and overhead is reduced.

[0056] FIG. 4 shows a flowchart of an example method 400 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of illustration, the method 400 will be described from the perspective of the second apparatus 220 in FIG. 2.

[0057] At block 410, the second apparatus 220 determines a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations.

[0058] In an example, the second apparatus 220 may be a receiver UE. The plurality of receiver configurations may include at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers, which may be available at the second apparatus 220 for monitoring the SL RP. Although the example embodiments of the present disclosure described below refer to beams (i.e., beam monitoring period, beam monitoring pattern, etc.), the present disclosure may be applied in other contexts, such as when multiple carriers need to be monitored by a UE but they cannot be monitored simultaneously, e.g., in sidelink carrier aggregation (SL CA). The following will explain the solution provided by example embodiments of the present disclosure in conjunction with beams as examples of receiver configurations. It can be understood that the solution provided by the present disclosure will be similarly applied to other receiver configurations, such as antennas, carriers, etc.

[0059] In some example embodiments, the monitoring period may be configured by a network or pre-configured for the sidelink resource pool. The monitoring period may be an integer, such as 3, 4, 5, etc. The monitoring period may be configured by a cellular network or preconfigured at the time of manufacturing the second apparatus 220. For example, a beam monitoring period may be configured or pre-configured by a new RRC parameter (e.g., sl-beamMonitoringPeriod) indicating the number of logical slots of the RP between monitored slots on each beam. In this way, all UEs using the RP have a consensus of the monitoring period. In an example, after determining the monitoring period, the second apparatus 220 may notify the monitoring period to transmitter UEs.

[0060] At block 420, the second apparatus 220 determines a periodic monitoring pattern based on the monitoring period and the monitoring pattern is associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations.

[0061] In an example, based on the (pre)configured monitoring period, the second apparatus 220 may determine a periodic beam monitoring pattern (or schedule) (bm, b(2), ..., b(N)) that repeats over time every N slots. For example, if the monitoring period is 4 and the second apparatus 220 monitors 4 beams (ao, ai, a2, a.3), the beam monitoring pattern is associated with these 4 beams and may be (b(1), b(2), b(3), b(4)) = (ao, ai, a2, as), i.e., the second apparatus 220 monitors the beams according to the periodic sequence (ao, ai, a2, as, ao, ai, a2, as, ...). In another example, if the second apparatus 220 is monitoring only 2 beams (ao, ai), the beam monitoring pattern may be (ao, ai, ao, ai) or (ao, ao, ai, ai), in which case the UE monitors the 2 beams alternately (every 1 or 2 slots). However, the beam monitoring pattern may also be (ao, ao, ao, ai) or (ao, ai, ai, ai), in which case the second apparatus 220 spends more time (i.e., slots) monitoring one of the beams over the other.

[0062] In some example embodiments, the second apparatus 220 may determine a number of time resources within the monitoring period for the periodic monitoring of the SL RP using the same receiver configuration based on various criteria. In an example, the second apparatus 220 may determine the number of time resources within the monitoring period for the periodic monitoring of the SL RP using the same receiver configuration based on an expected amount of traffic to be received using the same receiver configuration. The second apparatus 220 may assign more time resources (e.g., slots) monitoring a beam if it expects a higher amount of traffic to be received on that beam.

[0063] In an example, the second apparatus 220 may determine the number of time resources within the monitoring period for the periodic monitoring of the SL RP using the same receiver configuration based on a channel busy ratio (CBR) measurement associated with the same receiver configuration. If a high CBR is determined on a beam, the second apparatus 220 may increase the number of slots allocated for monitoring the congested beam and assign fewer slots for monitoring other less congested beams.

[0064] In an example, the second apparatus 220 may determine the number of time resources within the monitoring period for the periodic monitoring of the SL RP using the same receiver configuration based on a priority of at least one transmission to be received using the same receiver configuration. The second apparatus 220 may assign more slots to beams associated with higher priority transmissions or higher priority links. For example, if there are two beams (i.e., ao and ai), the monitoring period is 4 and the second apparatus 220 expects high priority transmissions to be received on beam ao, and low priority transmissions on beam ai, the second apparatus 220 may determine the beam monitoring pattern (ao, ao, ao, ai) or even (ao, ao, ao, ao) (i.e., full-time monitoring of a single, high-priority beam).

[0065] In another example, the second apparatus 220 may determine the number of time resources within the monitoring period for the periodic monitoring of the SL RP using the same receiver configuration based on the number of active receiver configurations being used for monitoring. The number of time resources may also depend on the number of beams being actively monitored by the second apparatus 220. For example, the monitoring period is N and the second apparatus 220 expects to monitor N different beams, it may only be possible to monitor one slot per beam within each beam monitoring period (i.e., slot is 1 for all monitored beams).

[0066] In some example embodiments, the monitoring pattern is determined to minimize a time gap between consecutive monitored time resources associated with the same receiver configuration. In a case that the number of beams being actively monitored is smaller than the (pre)configured beam monitoring period (N), when determining the beam monitoring pattern, the second apparatus 220 may minimize the time gap between consecutive monitoring occasions for any given beam. For example, assuming N = 4, if the second apparatus 220 is monitoring only two beams (ao, ai), the interleaved monitoring pattern (ao, ai, ao, ai) results in a maximum time gap of 1 slot between consecutive monitored slots on each beam, whereas the monitoring pattern (ao, ao, ai, ai) results in a maximum time gap of 2 slots between consecutive monitored slots on each beam.

[0067] In some example embodiments, the second apparatus 220 may transmit coordination information indicating at least one of the monitoring period or the monitoring pattern. For example, the second apparatus 220 may transmit coordination information, e.g., using SCI or higher layer signaling (such as a MAC CE) for inter-UE coordination (IUC), indicating the determined beam monitoring period and / or the determined beam monitoring pattern. Such coordination information may be used by nearby peer UEs to select appropriate time resources for communicating with the second apparatus 220, e.g., slots in which the second apparatus 220 is expected to monitor a preferred receive beam to receive transmissions from the respective peer UE. In an example, the second apparatus 220 may encrypt the coordination information in the application layer such that only the intended recipients will be able to decrypt and receive it. In this way, malicious attackers will not be able to identify the beam monitoring pattern and cannot create further interference intentionally.

[0068] At block 430, the second apparatus 220 uses at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern.

[0069] In an example, if there are 2 beams (ao and ai) and the beam monitoring pattern is (ao, ai, ao, ai), the second apparatus 220 may use ao for sequential monitoring of the SL RP (e.g. in slot 0, 2, 4, etc.) and may use ai for sequential monitoring of the SL RP (e.g. in slot 1, 3, 5, etc.). In another example, if there are 4 beams (ao, ai, a2, as) and the beam monitoring pattern is (ao, ai, a2, as), the second apparatus 220 may use ao for sequential monitoring of the SL RP (e.g. in slot 0, 4, 8, etc.), ai for sequential monitoring of the SL RP (e.g. in slot 1, 5, 9, etc.), a2 for sequential monitoring of the SL RP (e.g. in slot 2, 6, 10, etc.) and as for sequential monitoring of the SL RP (e.g. in slot 3, 7, 11, etc.).

[0070] In an example, the second apparatus 220 may only monitor a subset of (currently active / monitored) beams at any given time, but it may also establish new links over other (currently inactive / non-monitored) beams by using (pre)configured dedicated slots to periodically monitor reference signals (RS) for initial beam pairing (IBP) (such as standalone SL channel state information reference signals (CSI-RSs)) on those other beams. For example, if the current beam monitoring pattern at the second apparatus 220 is (ao, ao, ao, ao), it may use periodically (pre)configured IBP-RS slots to monitor beam al and, in case an IBP-RS is detected, e.g., from UE Bl,establish a new link with UE Bl and start periodically monitoring beam ai, e.g., by adapting its beam monitoring pattern to (ao, ai, ao, ai).

[0071] In some example embodiments, the monitoring period is shorter than a reference monitoring period and the reference monitoring period is configured by a network or preconfigured for the SL RP. The reference monitoring period may also be configured by a cellular network or pre-configured at the time of manufacturing the second apparatus 220 for the SL RP.

[0072] In an example, when the reference monitoring period (M) is determined as 4 and the beam monitoring pattern is (ao, ai, ao, ai), the actual monitoring period (N) for a given beam may be shorter (i.e., N = 2) than the reference monitoring period which is which is (pre)configured for the SL RP. Therefore, the resource reservation gap constraint may be relaxed (e.g., reduced from 4 to 2 slots) to reduce latency. Such relaxation may depend on certain conditions being fulfilled. For example, if all (or a large subset of) nearby UEs, in particular those located within the angular range of a beam to be used for transmission by the second apparatus 220, are known (e.g., via IUC) to use a shorter beam monitoring period (e.g., N = 2) than the reference monitoring period which is (pre)configured in the RP (e.g., M = 4), the logical slot offset(s) (ti, t2) between an initial transmission and a retransmission, or the resource reservation period (PUvpT\). may be allowed to take values that are an integer multiple of the shorter beam monitoring period (i.e., N = 2). The second apparatus 220 may determine which UEs are located within the angular range of its transmitting beam based on RSRP measurements using the intended transmit beam as a receive beam (i.e., exploiting TX / RX beam correspondence).

[0073] In a case where the resource reservation gap constraint is relaxed (i.e., reduced compared to the (pre)configured reference monitoring period), the second apparatus 220 may indicate the actual value of the monitoring period it is currently using (e.g., using a new SCI field). For example, assuming the reference monitoring period equals 4, if the second apparatus 220 determines that all nearby UEs within the angular range of its transmit beam are respectively monitoring a single beam on every slot (i.e., the actual beam monitoring period is 1), the second apparatus 220 may ignore the resource reservation gap constraint in its resource selection, and indicate the actual beam monitoring period in its SCI (e.g., by indicating 1).

[0074] In some example embodiments, the second apparatus 220 may determine, at least based on the monitoring period, whether a candidate resource is excluded from a candidate resource set of the sidelink resource pool.

[0075] In some example embodiments, in accordance with a determination that the candidate resource occurs in a slot expected, according to the monitoring period, to be monitored with a receiver configuration other than a receiver configuration determined for sidelink reception in the candidate resource, the second apparatus 220 may exclude the candidate resource from the candidate resource set. When performing candidate resource exclusion (i.e., based on sensing) from a candidate resource set, the UE may take into account the monitoring period. For example, when determining a preferred resource set for a corresponding transmitter UE, the second apparatus 220 may exclude candidate resources occurring in slots in which the second apparatus 220 does not expect to monitor the associated receive beam (e.g., a beam that has previously been determined as preferred for receiving transmissions from the transmitter UE).

[0076] In some example embodiments, in accordance with a determination that a time offset between the candidate resource and a non-monitored slot is an integer multiple of the monitoring period, the second apparatus 220 may exclude the candidate resource from the candidate resource set. The second apparatus 220 may take into account the beam monitoring period when performing resource exclusion based on non-monitored slots. For example, if the monitoring period is 4 and a SCI transmitted in slot n (i.e., the nonmonitored slot) reserves the candidate resource in slot n+8 (8 is the multiple of the monitoring period), the second apparatus 220 may exclude the candidate resource from the candidate resource set because there may be an overlapping resource reservation.

[0077] In some example embodiments, in accordance with a determination that the time offset between the candidate resource and the non-monitored slot is not an integer multiple of the monitoring period, the second apparatus 220 may abstain from excluding the candidate resource from the candidate resource set. If a hypothetical SCI which was transmitted in a non-monitored slot cannot indicate a resource in a given candidate slot in the resource selection window (RSW), there is no need to exclude candidate resources in that slot. For example, if the monitoring period is 4 and a SCI transmitted in slot n (i .e., the non-monitored slot) reserves the candidate resource in slot n+7 (7 is not the multiple of the monitoring period), the second apparatus 220 may abstain from excluding the candidate resource from the candidate resource set. In this way, unnecessary candidate resource exclusion may be avoided.

[0078] An example SL resource reservation process will be described in detail below with reference to FIG. 5.

[0079] FIG. 5 illustrates a flowchart of an example process 500 of SL resource reservation in accordance with some example embodiments of the present disclosure. In this example, a UE A 510 operates as an example implementation of the second apparatus 220 in FIG. 2, and a UE B 520 operates as an example implementation of the first apparatus 210 in FIG. 2.

[0080] As shown in FIG. 5, in the process 500, at 522, a monitoring period for periodic monitoring (N) for periodic monitoring of sidelink RP using the same beam / carrier (as an example implementation of the receiver configuration) may be determined in the UE B 520. The monitoring period may be configured by a network or pre-configured for the SL RP. In an example, a beam monitoring period may be configured or pre-configured by a new RRC parameter (e.g., sl-beamMonitoringPeriod) indicating the number of logical slots of the RP between monitored slots on each beam. In this way, all UEs using the RP have a consensus of the monitoring period.

[0081] At 524, a monitoring period for periodic monitoring (N) for periodic monitoring of SL RP using the same beam / carrier (as an example implementation of the receiver configuration) may be determined in the UE A 510. In an example, the monitoring period determined in the UE A 510 may be the same as the monitoring period determined in the UEB 520.

[0082] At 526, the UE A 510 may determine a periodic monitoring pattern (b(1), b(2), b(3), 5(4)) comprising at least two beams / carriers. The monitoring pattern maps slots to beams / carriers. In an example, if the monitoring period is 4 and the UE A 510 monitors 4 beams (ao, ai, a2, as), the beam monitoring pattern is associated with these 4 beams and may be (b(1), b(2), b(3), b(4)) = (ao, ai, a2, as).

[0083] At 528, the UE A 510 may use the at least two beams / carriers for sequential monitoring of RP according to the monitoring pattern. In an example, if there are 2 beams (ao and ai) and the beam monitoring pattern is (ao, ai, ao, ai), the UE A 510 may use aofor sequential monitoring of the SL resource pool (e.g. in slot 0, 2, 4, etc.) and may use ai for sequential monitoring of the SL resource pool (e.g. in slot 1, 3, 5, etc.).

[0084] At 530, the UE A 510 may transmit coordination information indicating the monitoring period and the monitoring pattern. Therefore, such coordination information may be used by the UE B 520 select appropriate time resources for communicating with the UE A 510.

[0085] At 532, the UE B 520 may select time offset (ti, ta) or resource reservation period (P’rsvp tx) to be an integer multiple of the monitoring period. In an example, if the monitoring period is N, the time offset (t 1, ts) or resource reservation period (P’rsvp tx) may be allowed to take values that are an integer multiple of N (i.e., N, 2N, 3N, 4N, etc.).

[0086] At 534, the UE B 520 may transmit SCI indicating time offset or resource reservation period as integer multiplier corresponding to integer multiple of the monitoring period. In an example, if the monitoring period is 4 and the time offset 12, the UE B 520 may transmit the control information indicating that the time offset as 3 (i.e., 12 / 4).

[0087] In some example embodiments, a first apparatus capable of performing the method 300 (for example, the first apparatus 210 in FIG. 2) may comprise means for performing the respective operations of the method 300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 210 in FIG. 2.

[0088] In some example embodiments, the first apparatus comprises means for determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; and means for performing at least one of: selecting a resource reservation period to be an integer multiple of the monitoring period, or selecting a time offset between a first transmission associated with a transport block (TB) and at least one second transmission associated with the TB to be an integer multiple of the monitoring period, wherein the plurality of receiver configurations comprise at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0089] In some example embodiments, the monitoring period is configured by a network or pre-configured for the sidelink resource pool.

[0090] In some example embodiments, the first apparatus further comprises: means for transmitting control information indicating the resource reservation period and / or the time offset as an integer multiplier corresponding to the integer multiple of the monitoring period.

[0091] In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 300 or the first apparatus 210 in FIG. 2. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

[0092] In some example embodiments, a second apparatus capable of performing the method 400 (for example, the second apparatus 220 in FIG. 2) may comprise means for performing the respective operations of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 220 in FIG. 2.

[0093] In some example embodiments, the second apparatus comprises means for determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; means for determining a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; and means for using at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern, wherein the plurality of receiver configurations comprise at least one of: a plurality of beams, a plurality of antennas, or a plurality of carriers.

[0094] In some example embodiments, the second apparatus further comprises: means for determining a number of time resources within the monitoring period for the periodic monitoring of the sidelink resource pool using the same receiver configuration based on at least one of: an expected amount of traffic to be received using the same receiver configuration, a channel busy ratio measurement associated with the same receiver configuration, a priority of at least one transmission to be received using the same receiver configuration, a priority of at least one link associated with the same receiver configuration, or a number of active receiver configurations being used for monitoring.

[0095] In some example embodiments, the monitoring pattern is determined to minimize a time gap between consecutive monitored time resources associated with the same receiver configuration.

[0096] In some example embodiments, the second apparatus further comprises: means for transmitting coordination information indicating at least one of the monitoring period or the monitoring pattern.

[0097] In some example embodiments, the monitoring period is shorter than a reference monitoring period, the reference monitoring period being configured by a network or pre-configured for the sidelink resource pool.

[0098] In some example embodiments, the second apparatus further comprises: means for determining, at least based on the monitoring period, whether a candidate resource is excluded from a candidate resource set of the sidelink resource pool.

[0099] In some example embodiments, the second apparatus further comprises: means for in accordance with a determination that the candidate resource occurs in a slot expected, according to the monitoring period, to be monitored with a receiver configuration other than a receiver configuration determined for sidelink reception in the candidate resource, excluding the candidate resource from the candidate resource set.

[0100] In some example embodiments, the second apparatus further comprises: means for in accordance with a determination that a time offset between the candidate resource and a non-monitored slot is an integer multiple of the monitoring period, excluding the candidate resource from the candidate resource set, and / or means for in accordance with a determination that the time offset between the candidate resource and the non-monitored slot is not an integer multiple of the monitoring period, abstaining from excluding the candidate resource from the candidate resource set.

[0101] In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 400 or the second apparatus 220 in FIG. 2. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the second apparatus.

[0102] FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, for example, the first apparatus 210 or the second apparatus 220 as shown in FIG. 2. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0103] The communication module 640 is for bidirectional communications. The communication module 640 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 640 may include at least one antenna.

[0104] The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: 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.

[0105] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

[0106] A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The instructions of the program 630 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 630 may be stored in the memory, e.g., the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[0107] The example embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIG. 3 to FIG. 5. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0108] In some example embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e g., RAM vs. ROM).

[0109] FIG. 7 shows an example of the computer readable medium 700 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 700 has the program 630 stored thereon.

[0110] 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, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method 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.

[0111] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. 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.

[0112] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code 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 code, 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.

[0113] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0114] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer 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 computer 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.

[0115] Further, although 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, although 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. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0116] Although the present disclosure has been described in languages 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

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:determine a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; andperform at least one of:selecting a resource reservation period to be an integer multiple of the monitoring period, orselecting a time offset between a first transmission associated with a transport block, TB, and at least one second transmission associated with the TB to be an integer multiple of the monitoring period,wherein the plurality of receiver configurations comprise at least one of:a plurality of beams,a plurality of antennas, ora plurality of carriers.

2. The first apparatus of claim 1, wherein the monitoring period is configured by a network or pre-configured for the sidelink resource pool.

3. The first apparatus of claim 1 or 2, wherein the at least one memory and the at least one processor further cause the first apparatus to:transmit control information indicating the resource reservation period and / or the time offset as an integer multiplier corresponding to the integer multiple of the monitoring period.

4. A second apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:determine a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations;determine a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; anduse at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern,wherein the plurality of receiver configurations comprise at least one ofa plurality of beams,a plurality of antennas, ora plurality of carriers.

5. The second apparatus of claim 4, wherein the at least one memory and the at least one processor cause the apparatus to:determine a number of time resources within the monitoring period for the periodic monitoring of the sidelink resource pool using the same receiver configuration based on at least one of:an expected amount of traffic to be received using the same receiver configuration,a channel busy ratio measurement associated with the same receiver configuration,a priority of at least one transmission to be received using the same receiver configuration,a priority of at least one link associated with the same receiver configuration, or a number of active receiver configurations being used for monitoring.

6. The second apparatus of claim 4 or 5, wherein the monitoring pattern is determined to minimize a time gap between consecutive monitored time resources associated with the same receiver configuration.

7. The second apparatus of any of claims 4-6, wherein the at least one memory and the at least one processor further cause the apparatus to:transmit coordination information indicating at least one of the monitoring period or the monitoring pattern.

8. The second apparatus of any of claims 4-7, wherein the monitoring period is shorter than a reference monitoring period, the reference monitoring period being configured by a network or pre-configured for the sidelink resource pool.

9. The second apparatus of any of claims 4-8, wherein the at least one memory and the at least one processor further cause the apparatus to:determine, at least based on the monitoring period, whether a candidate resource is excluded from a candidate resource set of the sidelink resource pool.

10. The second apparatus of claim 9, wherein the at least one memory and the at least one processor cause the apparatus to:in accordance with a determination that the candidate resource occurs in a slot expected, according to the monitoring period, to be monitored with a receiver configuration other than a receiver configuration determined for sidelink reception in the candidate resource, exclude the candidate resource from the candidate resource set.

11. The second apparatus of claim 9, wherein the at least one memory and the at least one processor cause the apparatus to:in accordance with a determination that a time offset between the candidate resource and a non-monitored slot is an integer multiple of the monitoring period, exclude thecandidate resource from the candidate resource set, and / orin accordance with a determination that the time offset between the candidate resource and the non-monitored slot is not an integer multiple of the monitoring period, abstain from excluding the candidate resource from the candidate resource set.

12. A method comprising:determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; andperforming at least one of:selecting a resource reservation period to be an integer multiple of the monitoring period, orselecting a time offset between a first transmission associated with a transport block, TB, and at least one second transmission associated with the TB to be an integer multiple of the monitoring period,wherein the plurality of receiver configurations comprise at least one of:a plurality of beams,a plurality of antennas, ora plurality of carriers.

13. A method comprising:determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations;determining a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; anduse at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern,wherein the plurality of receiver configurations comprise at least one of:a plurality of beams,a plurality of antennas, or a plurality of carriers.

14. A first apparatus comprising:means for determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations; andmeans for performing at least one of:selecting a resource reservation period to be an integer multiple of the monitoring period, orselecting a time offset between a first transmission associated with a transport block, TB, and at least one second transmission associated with the TB to be an integer multiple of the monitoring period,wherein the plurality of receiver configurations comprise at least one of:a plurality of beams,a plurality of antennas, ora plurality of carriers.

15. A second apparatus comprising:means for determining a monitoring period for periodic monitoring of a sidelink resource pool with a same receiver configuration among a plurality of receiver configurations;means for determining a periodic monitoring pattern based on the monitoring period, the monitoring pattern being associated with at least a first receiver configuration and a second receiver configuration among the plurality of receiver configurations; andmeans for using at least the first receiver configuration and the second receiver configuration for sequential monitoring of the sidelink resource pool according to the monitoring pattern.

16. A computer readable medium comprising instructions stored thereon for causingan apparatus at least to perform the method of claim 12 or the method of claim 13.

Images