Micro-sleep techniques in star topology sidelink communications

Abstract

Methods, systems, and devices for wireless communication are described. A central user equipment (UE) in a star topology can broadcast to a set of peripheral UEs to indicate time slots in which the central UE will not be in a transmit mode. The central UE can broadcast a time slot format indication to the peripheral UEs to indicate a mode of operation in a set of time slots. In a first group of time slots, the central UE can operate in a forward mode, transmitting sidelink communications to the peripheral UEs. In a second group of time slots, the central UE can operate in a reverse mode, receiving sidelink communications from the peripheral UEs. In a time slot in which the central UE operates in the reverse mode, if the peripheral UEs have no data or control information, the peripheral UEs can enter a sleep mode in one or more time slots in the second group to conserve power.

Description

[0001] Cross Reference to Related Applications

[0002] This Patent Application claims priority to U.S. Patent Application No. 17 / 360,697 by XUE et al., entitled “MICRO SLEEP TECHNIQUES IN STAR TOPOLOGY SIDELINK COMMUNICATIONS,” filed June 28, 2021; which claims benefit of U.S. Provisional Patent Application No. 63 / 064,385 by XUE et al., entitled “MICRO SLEEP TECHNIQUES IN STAR TOPOLOGY SIDELINK COMMUNICATIONS,” filed August 11, 2020; each of which is assigned to the assignee hereof. TECHNICAL FIELD

[0003] The following relates to wireless communications, including micro sleep techniques in star topology sidelink communications. BACKGROUND

[0004] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems can be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple- access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which can be referred to as New Radio (NR) systems. These systems can employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system can include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which can be otherwise known as user equipment (UE). SUMMARY

[0005] The present disclosure relates to methods, systems, devices, and apparatuses that support micro-sleep techniques in star topology sidelink communications. Generally, the described techniques provide for enabling a hub user equipment (UE) to broadcast to a set of peripheral UEs in a star topology to indicate time slots in which the hub UE will not be in a transmitting mode, which can enable the peripheral UEs to enter a power saving sleep mode in time slots in which the hub UE is not transmitting. The hub UE can broadcast a slot format indication (SFI) to the peripheral UEs to indicate operating modes in a set of time slots. In one aspect, in a first group of time slots, the hub UE can operate in a “forward” mode, transmitting sidelink communications to the peripheral UEs. In a second group of time slots, the hub UE can operate in a “reverse” mode, receiving sidelink communications from the peripheral UEs. In some aspects, the hub UE can operate in an “unavailable” mode in a third group of time slots, in which the hub UE is neither in a transmitting mode nor a receiving mode with respect to the peripheral UEs. In time slots in which the hub UE operates in the reverse mode, if the peripheral UEs have no data or control information, the peripheral UEs can enter a sleep mode (e.g., micro-sleep) in one or more time slots in the second group to conserve power. In some aspects, the SFI can be arranged as an array indicating time slots and corresponding operating modes. In some aspects, the SFI can be broadcast in a sidelink control information (SCI) message or higher layer signaling.

[0006] A method of wireless communication implemented by a first UE is described. The method can include determining, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes, transmitting, to a set of second UEs, a slot format indication for the set of slots indicating the respective operating modes, and communicating, with one or more second UEs of the set of second UEs, in one or more slots of the set of slots based on transmitting the slot format indication.

[0007] A wireless communication apparatus implemented by a first UE is described. The apparatus can include a processor, a memory coupled with the processor, and instructions stored in the memory. The instructions can be executable by the processor to cause the apparatus to determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes, transmit, to a set of second UEs, a slot format indication for the set of slots indicating the respective operating modes, and communicate, with one or more second UEs of the set of second UEs, in one or more slots of the set of slots based on transmitting the slot format indication.

[0008] Another apparatus for wireless communication implemented by a first UE is described. The apparatus can include means for determining, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes; transmitting, to a set of second UEs, a slot format indication for the set of slots indicating the respective operating modes; and communicating, with one or more second UEs of the set of second UEs, in one or more slots of the set of slots based on transmitting the slot format indication.

[0009] A non-transitory computer-readable medium storing code for wireless communication implemented by a first UE is described. The code can include instructions executable by a processor to determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes; transmit, to a set of second UEs, a slot format indication for the set of slots indicating the respective operating modes; and communicate, with one or more second UEs of the set of second UEs, in one or more slots of the set of slots based on transmitting the slot format indication.

[0010] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for generating an array indicating the set of slots and the respective operating modes, where the slot format indication includes the array.

[0011] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for identifying, based on determining the respective operating modes for the set of slots, a first operating mode corresponding to a first subset of the set of slots and a second operating mode corresponding to a second subset of the set of slots, and transmitting, based on identifying the first operating mode, a first sidelink transmission to a second UE of the set of second UEs in one or more slots of the first subset.

[0012] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, based on identifying the second operating mode, a second sidelink transmission from a second UE of the set of second UEs in one or more slots of the second subset.

[0013] In some examples of the method, apparatus, and non-transitory computer-readable medium described herein, transmitting the slot format indication can include operations, features, means, or instructions for transmitting the slot format indication in a sidelink control information message.

[0014] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, transmitting the slot format indication in the sidelink control information message can include operations, features, means, or instructions for identifying control information in the sidelink control information message, and appending the slot format indication to the control information in the sidelink control information message based on a determination that a modulation and coding scheme used for the sidelink control information message can be compatible with transmitting the slot format indication.

[0015] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the sidelink control information message includes an indication of the slot format indication and a network identifier associated with the first UE and the set of second UEs.

[0016] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for identifying a configured grant occasion associated with a slot of the set of slots, where the configured grant occasion schedules a sidelink communication with a second UE of the set of second UEs in the slot, determining a mismatch between the scheduled sidelink communication and a respective operating mode for the slot, and refraining from transmitting the sidelink communication with the second UE in the slot based on the determination of the mismatch.

[0017] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for identifying a third operating mode corresponding to a third subset of the set of slots based on determining the respective operating mode of the set of slots, and refraining from communicating with the set of second UEs in one or more slots of the third subset based on identifying the third operating mode.

[0018] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for deactivating one or more transmission components at the first UE in one or more slots of the third subset based on identifying the third operating mode, where refraining from communicating with the set of second UEs in one or more slots of the third subset can be further based on deactivating the one or more transmission components.

[0019] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for transmitting, to the set of second UEs, a feedback indication indicating a fourth subset of the set of slots for feedback associated with the sidelink communication, identifying a respective operating mode of each slot of the fourth subset based on determining the respective operating mode of the set of slots, and transmitting the feedback with one or more second UEs of the set of second UEs in one or more slots of the fourth subset based on transmitting the feedback indication and identifying the respective operating mode.

[0020] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, determining the respective operation modes for the set of slots can include operations, features, means, or instructions for determining a respective operation mode for a set of subbands in each slot of the set of slots, where the slot format indication for the set of slots indicates the respective operation mode for the set of subbands.

[0021] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, transmitting the slot format indication can include operations, features, means, or instructions for transmitting the slot format indication in each subband of the set of subbands.

[0022] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, transmitting the slot format indication can include operations, features, means, or instructions for transmitting the slot format indication in a medium access control control element, a radio resource control message, or any combination thereof.

[0023] A method of wireless communication implemented by a second UE is described. The method can include receiving, from a first UE, a slot format indication indicating respective operation modes for sidelink communications in a set of slots, each operation mode selected from a set of operation modes; determining, based on receiving the slot format indication, a first operation mode corresponding to a first subset of the set of slots and a second operation mode corresponding to a second subset of the set of slots; and communicating with the first UE in one or more slots of the set of slots based on determining the first operation mode and the second operation mode.

[0024] A apparatus of wireless communication implemented by a second UE is described. The apparatus can include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions can be executable by the processor to cause the apparatus to receive, from a first UE, a slot format indication indicating respective operation modes for sidelink communications in a set of slots, each operation mode selected from a set of operation modes; determine, based on receiving the slot format indication, a first operation mode corresponding to a first subset of the set of slots and a second operation mode corresponding to a second subset of the set of slots; and communicate with the first UE in one or more slots of the set of slots based on determining the first operation mode and the second operation mode.

[0025] Another apparatus for wireless communication implemented by a second UE is described. The apparatus can include means for receiving, from a first UE, a slot format indication indicating respective operating modes for sidelink communications in a set of slots, each operating mode selected from a set of operating modes; determining, based on receiving the slot format indication, a first operating mode corresponding to a first subset of the set of slots and a second operating mode corresponding to a second subset of the set of slots; and communicating with the first UE in one or more slots of the set of slots based on determining the first operating mode and the second operating mode.

[0026] A non-transitory computer-readable medium storing code for wireless communication implemented by a second UE is described. The code can include instructions executable by a processor to receive, from a first UE, a slot format indication indicating respective operating modes for sidelink communications in a set of slots, each operating mode selected from a set of operating modes; determine, based on receiving the slot format indication, a first operating mode corresponding to a first subset of the set of slots and a second operating mode corresponding to a second subset of the set of slots; and communicate with the first UE in one or more slots of the set of slots based on determining the first operating mode and the second operating mode.

[0027] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for identifying an array indicating the set of slots and the respective operating modes, where the slot format indication includes the array.

[0028] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for receiving, from the first UE, a first sidelink transmission in one or more slots of the first subset based on determining the first operating mode.

[0029] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for transmitting, to the first UE, a second sidelink transmission in one or more slots of the second subset based on determining the second operating mode.

[0030] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for entering a sleep mode in at least a portion of the slots of the second subset based on determining the second operating mode, and refraining from communicating with the first UE in the at least the portion of the slots of the second subset based on entering the sleep mode.

[0031] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, receiving the slot format indication can include operations, features, means, or instructions for receiving the slot format indication in a sidelink control information message.

[0032] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the sidelink control information message includes an indication of the slot format indication and a network identifier associated with the first UE and the second UE.

[0033] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include identifying a configured grant occasion associated with a slot of the set of slots, where the configured grant occasion schedules a sidelink communication with the first UE in the slot, determining a mismatch between the scheduled sidelink communication and a respective operating mode for the slot, and refraining from communicating with the first UE in the slot based on determining the mismatch.

[0034] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for entering a sleep mode in the slot based on determining the mismatch, where refraining from communicating with the first UE in the slot can be further based on entering the sleep mode.

[0035] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, refraining from communicating with the first UE in the slot can include operations, features, means, or instructions for refraining from decoding a sidelink communication with the first UE in the slot based on determining the mismatch.

[0036] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for determining a third operating mode corresponding to a third subset of the set of slots based on receiving the slot format indication, entering a sleep mode in at least a portion of the slots in the third subset based on determining the third operating mode, and refraining from communicating with the first UE in the at least portion of the slots in the third subset based on entering the sleep mode.

[0037] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for receiving, from the first UE, a feedback indication indicating a fourth subset of the set of slots for feedback associated with the sidelink communication, identifying a respective operating mode for each slot in the fourth subset based on receiving the slot format indication, and transmitting feedback with the first UE in one or more slots in the fourth subset based on receiving the feedback indication and identifying the respective operating mode.

[0038] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, communicating the feedback with the first UE can include operations, features, means, or instructions for refraining from communicating the feedback with the first UE in a first slot of the fourth subset based on identifying a respective operation mode of the first slot, and communicating the feedback with the first UE in a second slot of the fourth subset based on identifying a respective operation mode of the second slot.

[0039] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the slot format indication indicates respective operation modes for a set of subbands in each slot of the set of slots.

[0040] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, receiving the slot format indication can include operations, features, means, or instructions for receiving the slot format indication in one or more subbands of the set of subbands.

[0041] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, receiving the slot format indication can include operations, features, means, or instructions for receiving the slot format indication in a medium access control control element, a radio resource control message, or any combination thereof. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 AND Figure 2 An example of a wireless communications system that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure.

[0043] Figure 3 AND Figure 4 An example of a timing diagram that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure.

[0044] Figure 5 An example of a process flow that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure.

[0045] Figure 6 AND Figure 7 A block diagram of a device that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure.

[0046] Figure 8 A block diagram of a communications manager that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure.

[0047] Figure 9 A diagram of a system including a device that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure.

[0048] Figures 10 to 13 A flow diagram illustrating a method that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0049] Some wireless communications systems can include one or more user equipment (UEs) and one or more base stations, such as next generation NodeBs or giga-NodeBs (any of which can be referred to as a gNB), which can support one or more multiple radio access technologies, including 4G systems such as Long Term Evolution (LTE) systems, fifth generation (5G) systems which can be referred to as New Radio (NR) systems, and Wi-Fi systems (e.g., wireless local area network (WLAN) systems). According to one or more of these example radio access technologies (RATs), one or more UEs can communicate directly with each other in a sidelink communication channel without transmitting through a base station or through a relay point. Sidelink communications can be an example of device-to-device (D2D) communications, vehicle-to-everything (V2X) communications, or another example of sidelink communications in a wireless communications system.

[0050] In certain cases, a set of UEs can be arranged in a star topology, where one UE can act as a central UE for a set of peripheral UEs. The peripheral UEs can not be aware of the scheduling of sidelink communications from the central UE. As a result, the peripheral UEs can continuously monitor for transmissions from the central UE, which can increase power consumption of the peripheral UEs.

[0051] According to the techniques described herein, a central UE can broadcast to peripheral UEs to indicate time slots in which the central UE will not be in a transmitting mode, which can enable the peripheral UEs to enter a power saving sleep mode in time slots in which the central UE is not transmitting. The central UE can broadcast a slot format indication (SFI) to the peripheral UEs to indicate operating modes in a set of time slots. In one aspect, in a first group of time slots, the central UE can operate in a “forward” mode, transmitting sidelink communications to the peripheral UEs. In a second group of time slots, the central UE can operate in a “reverse” mode, receiving sidelink communications from the peripheral UEs. In some aspects, the central UE can operate in an “unavailable” mode in a third group of time slots, in which the central UE is neither in a transmitting mode nor in a receiving mode with respect to the peripheral UEs. In time slots in which the central UE operates in the “reverse” mode, if the peripheral UEs have no data or control information, the peripheral UEs can enter a sleep mode (e.g., micro-sleep) in one or more time slots in the second group to conserve power. In some aspects, the SFI can be arranged as an array indicating time slots and corresponding operating modes. In some aspects, the SFI can be broadcast in a sidelink control information (SCI) message or higher layer signaling.

[0052] Aspects of the disclosure are initially described in the context of a wireless communications system. Further aspects of the disclosure are illustrated and described in further detail with reference to timing diagrams, process flow diagrams, apparatus diagrams, system diagrams, and flow diagrams related to micro-sleep techniques in star topology sidelink communications.

[0053] Figure 1 An example of a wireless communications system 100 that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure. The wireless communications system 100 can include one or more base stations 105, one or more UEs 115, and a core network 130. In some aspects, the wireless communications system 100 can be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some aspects, the wireless communications system 100 can support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0054] The base stations 105 can be dispersed throughout the geographic area 100 and can be of different forms or have different capabilities. The base stations 105 and UEs 115 can wirelessly communicate via one or more communication links 125. Each base station 105 can provide a coverage area 110 over which UEs 115 and base stations 105 can establish one or more communication links 125. The coverage area 110 can be an example of a geographic area over which base stations 105 and UEs 115 can support communication in accordance with one or more radio access technologies.

[0055] The UEs 115 can be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 can be stationary, or mobile, or both at different times. The UEs 115 can be devices in different forms or having different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein can be able to communicate with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in FIG. 1. Figure 1 The UEs 115 described herein can be able to communicate as relay devices in a mesh network of UEs 115, as shown in FIG. 1. For example, a mesh network of UEs 115 can be used to communicate traffic between base stations 105, between core network nodes, or a combination thereof.

[0056] The base stations 105 can communicate with the core network 130, or with one another, or both. In an aspect, the base stations 105 can interface with the core network 130 through one or more backhaul links 120 (e.g., via an SI, N2, N3, or other interface). The base stations 105 can communicate with the core network 130 through the backhaul links 120 (e.g., using S I, N2, N3, or other interface) using wired or wireless communication protocols. In some aspects, the backhaul links 120 can be or include one or more wireless links.

[0057] One or more of the base stations 105 described herein can include or can be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or giga-NodeB (either of which can be referred to as a gNB), a Home NodeB, or a Home eNodeB, among other examples. The UEs 115 described herein can be able to communicate with various types of base stations, such as eNode-Bs (eNBs), giga-Node-Bs (gNBs), or other types of base stations.

[0058] The UEs 115 described herein can include or can be referred to as mobile devices, wireless devices, remote devices, handheld devices, or subscriber devices, or some other suitable terminology, where the “device” can also be referred to as a unit, a station, a terminal, a client, a customer device, etc. The UEs 115 can also include or can be referred to as personal electronic devices such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some aspects, the UE 115 can include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which can be implemented in various objects such as appliances, or vehicles, meters, etc.

[0059] The UEs 115 described herein can be able to communicate with various types of devices, such as other UEs 115, base stations 105, or network equipment including Figure 1 Other UEs 115 and base stations 105 are shown that can sometimes act as relays, and a network equipment including a macro eNB or gNB, a small cell eNB or gNB, or a relay base station, among other examples.

[0060] The UEs 115 and the base stations 105 can wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” can refer to a set of radio frequency spectrum resources (e.g., frequency channels) with a defined physical layer structure configured for supporting

[0061] Signal waveforms transmitted over a carrier can be composed of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In

[0062] Time intervals for the base stations 105 or the UEs 115 can be expressed in multiples of a basic time unit which may, for example, be a T s = 1 / (Df max · N f ) seconds, where Df max may represent the maximum supported subcarrier spacing, and N f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource can be organized as radio frames, each

[0063] Each frame can include a plurality of sequentially numbered subframes or slots, and each subframe or slot can have the same duration. In some aspects, a frame can be partitioned (e.g., in the time domain) into subframes, and each subframe can be further partitioned into a number of slots. Alternatively, each frame can include a variable number of slots, and the number of slots can depend on the subcarrier spacing. Each slot can include a plurality of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communication systems 100, slots can also be partitioned into a number of mini-slots containing one or more symbols. Depending on the protocol, a mini-slot can contain one symbol period or multiple symbol periods. A subframe, a slot, a mini-slot, or a symbol can be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and can be referred to as a transmission time interval (TTI). In some aspects, the TTI duration (e.g., the number of symbol periods in a TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)). f ) sampling periods. The duration of a symbol period can depend on the subcarrier spacing or the operating band.

[0064] A subframe, a slot, a mini-slot, or a symbol can be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and can be referred to as a transmission time interval (TTI). In some aspects, the TTI duration (e.g., the number of symbol periods in a TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0065] Physical channels can be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel on the downlink carrier can be multiplexed using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel can be defined by a number of symbol periods and can extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. In one aspect, one or more UEs 115 can monitor or search control regions for control information according to one or more search space sets, and each search space set can include one or more control channel candidates arranged in a cascaded manner according to one or more aggregation levels. An aggregation level for a control channel candidate can refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with an encoded information for a control information format having a given payload size. Search space sets can include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets used for sending control information to a specific UE 115.

[0066] In some aspects, base stations 105 can be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some aspects, different geographic coverage areas 110 associated with different technologies can overlap, but the different geographic coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communications system 100 can include, in one aspect, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0067] Some UEs 115, such as MTC or IoT devices, can be low cost or low complexity devices and can provide for automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with one another or a base station 105 without the need for human intervention. In some aspects, M2M communication or MTC can include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that makes use of the information or presents the information to humans in interaction with the application program. Some UEs 115 can be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

[0068] Some UEs 115 can be configured to employ operating modes that reduce power consumption, such as a half-duplex

[0069] The wireless communications system 100 can be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. In an aspect, the wireless communications system 100 can be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. UEs 115 can be designed to support ultra-reliable, low-latency, or mission critical (e.g., mission critical function) functions. Ultra-reliable communications can include private communication or group communication and can be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions can include prioritization of services, and mission critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low- latency are used interchangeably herein.

[0070] In some aspects, UE 115 can also be able to communicate directly with other UEs 115 using a D2D communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communications can be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group can be outside the geographic coverage area 110 of a base station 105 or be otherwise unable to receive transmissions from a base station 105. In some aspects, groups of UEs 115 communicating via D2D communications can utilize a one-to-many (1 :M) system in which each UE 115 transmits to every other UE 115 in the group. In some aspects, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between UEs 115 without the involvement of a base station 105.

[0071] In some systems, the D2D communication link 135 can be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115). In some aspects, vehicles can communicate using V2X communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle can signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some aspects, vehicles in a V2X system can communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or with both.

[0072] The core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 can be an evolved packet core (EPC) or 5G core (5GC), which can include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets to and from user equipment (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity can manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the core network 130. User IP packets can be transferred through the user plane entity, which can provide IP address allocation as well as other functions. The user plane entity can be connected to the network operators IP services 150. The operators IP services 150 can include access to the Internet, Intranet(s), an IP multimedia subsystem (IMS), or a packet-switched streaming service.

[0073] Some of the network devices, such as a base station 105, can include subcomponents such as an access network entity 140, which can be an example of an access node controller (ANC). Each access network entity 140 can communicate with the UEs 115 through one or more other access network transmission entities 145, which can be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transmission entity 145 can include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 can be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105).

[0074] The wireless communications system 100 can operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves can be blocked or redirected by buildings and environmental features, but the waves can penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the low frequency (LF) or very high frequency (VHF) parts of the spectrum below 300 MHz.

[0075] Wireless communications system 100 can utilize both licensed and unlicensed radio spectrum bands. In one aspect, wireless communications system 100 can employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed radio frequency spectrum band such as the 5 GHz Industrial, Scientific, and Medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, base stations 105 and UEs 115 such as base station 105 and UE 115 can employ carrier sensing for collision detection and avoidance in the unlicensed radio frequency spectrum band. In some aspects, operations in unlicensed bands can be based on a carrier aggregation configuration in conjunction with operations in a licensed band (e.g., LAA). Operations in unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, D2D transmissions, or the like.

[0076] Base stations 105 or UEs 115 can be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. Base stations 105 or UEs 115 can have one or more antenna arrays or antenna panels that support MIMO operations or beamforming. In one aspect, one or more base station antennas or antenna arrays can be co-located at an antenna assembly, such as an antenna tower. In some aspects, the antennas or antenna arrays associated with a base station 105 can be located in different geographic locations. A base station 105 can have an antenna array with a number of rows and columns of antenna ports that the base station 105 can use to support beamforming of communications with UEs 115. Similarly, a UE 115 can have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, antenna panels can support radio frequency beamforming of signals transmitted via antenna ports.

[0077] Beamforming, which can also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer a beam of energy in the manner of fan or lobe in a specific spatial direction. Beamforming can be achieved by combining the signals transmitted or received by antennas of an array of antennas such that signals at particular orientations experience constructive interference while others experience destructive interference. The combination of signals can be performed with signal processing, such as by adding, subtracting, or phase shifting the signals transmitted or received by the antennas. The signal processing can be performed in place on the array of antennas, which can be referred to as analog beamforming. In some aspects, the

[0078] UE 115 and base station 105 can support data retransmission to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique to increase the likelihood of correct data reception over communication link 125. HARQ can include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve throughput at the Media Access Control (MAC) layer under poor radio conditions (e.g., low signal-to-noise ratio conditions). In some aspects, the equipment can support simultaneous time-slot HARQ feedback, where the equipment can provide HARQ feedback in a specific time slot for data received in a previous symbol within that time slot. In other cases, the equipment can provide HARQ feedback in subsequent time slots or according to some other time interval.

[0079] According to the techniques described herein, in a star topology, the central UE 115 can broadcast to the peripheral UE 115 indicating that the central UE 115 will not be in a transmit mode in a time slot. This allows the peripheral UE 115 to enter a power-saving sleep mode in the time slots where the central UE 115 is not transmitting. The central UE 115 can broadcast an SFI to the peripheral UE 115 to indicate the operating mode in the time slot set. In one aspect, in a first time slot group, the central UE 115 can operate in a "forward" mode, transmitting sidelink communication to the peripheral UE 115. In a second time slot group, the central UE 115 can operate in a "reverse" mode, receiving sidelink communication from the peripheral UE 115. In some aspects, the central UE 115 can operate in an "unavailable" mode in a third time slot group, wherein the central UE 115 is neither in transmit nor receive mode relative to the peripheral UE 115. In a time slot where the central UE 115 is operating in reverse mode, if the peripheral UE 115 has no data or control information, the peripheral UE 115 may enter a sleep mode (e.g., micro-sleep) in one or more time slots in the second group to conserve power. In some aspects, the SFI can be arranged as an array indicating time slots and corresponding operating modes. In some aspects, the SFI can be broadcast in an SCI message or higher-level signaling.

[0080] Figure 2 An example of a wireless communication system 200 supporting microsleep technology in star topology sidelink communication is shown according to various aspects of this disclosure. In some aspects, the wireless communication system 200 may implement various aspects of the wireless communication system 100. The wireless communication system 200 may include a base station 205 and a UE 215, which may be referenced... Figure 1Aspects of the corresponding apparatus are described. The wireless communications system 200 can include features for improved sidelink communication operations, among other benefits.

[0081] The UEs 215 can transmit and receive communications under the scheduling of the base stations 205. In some aspects, the UEs 215 can communicate directly with one another (e.g., through reference Figure 1 to the D2D communication links 135 described) without transmitting through the base stations 205. The sidelink communications 225 can illustrate aspects of D2D communication, V2X communication, or another communication aspect in the wireless communications system 200. In some aspects, the sidelink communications 225 can include physical sidelink control channel (PSCCH) transmissions, physical sidelink shared channel (PSSCH) transmissions, physical sidelink feedback channel (PSFCH) transmissions, or any combination thereof.

[0082] In certain cases, the UEs 215 can communicate with one another in a star topology (which can be referred to as a star network), where the UE 215-a can act as a hub coordinating communications with the UEs 215-b, 215-c, and 215-d (which can be referred to as peripheral UEs 215). That is, the peripheral UEs 215-b, 215-c, and 215-d can transmit data to and receive data from the hub UE 215-a in the sidelink communications 225. In some aspects, the roles of the hub UE 215 and the peripheral UEs 215 can be determined dynamically based on temporal traffic flows, rather than being fixed. That is, in Figure 2 In the illustrated aspects, the UE 215-a can act as a hub UE 215, and in another aspect, the UE 215-b (or the UE 215-c, the UE 215-d, etc.) can act as a hub UE 215 for the set of UEs 215.

[0083] In some aspects, the star topology can include additional peripheral UEs 215 (not shown). The star topology can provide large capacity for extensive use of the peripheral UEs 215. In certain cases, traffic to or from a single peripheral UE 215 (e.g., the UE 215-b) can be indeterminate (e.g., random, or having non-trivial jitter on a coarse pattern such as the sidelink communications 225-a between the UEs 215-a and 215-b).

[0084] In some cases, one or more peripheral UEs 215 can operate on battery power and power efficiency can be an important consideration for communications between UEs 215 in a star topology. However, the peripheral UEs 215 can not be aware of the scheduling of sidelink communications 225 from the central UE 215-a. As a result, the peripheral UEs 215 can continuously monitor for transmissions from the central UE 215-a, which can increase power consumption of the peripheral UEs 215.

[0085] According to the techniques described herein, the central UE 215-a can broadcast an SFI 220 to the peripheral UEs 215 to indicate the mode of operation in a set of slots. In one aspect, in a first group of slots, the central UE 215-a can operate in a “forward” mode, transmitting sidelink communications 225 to the peripheral UEs 215. In a second group of slots, the central UE 215-a can operate in a “reverse” mode, receiving sidelink communications 225 from the peripheral UEs 215. In slots in which the central UE 215-a operates in the reverse mode, if a peripheral UE 215 (e.g., UE 215-b) does not have data or control information to transmit to the central UE 215-a, the peripheral UE 215 can enter a sleep mode (e.g., micro-sleep) in one or more slots (or partial slots) in the second group to conserve power. In some aspects, the SFI 220 can be arranged as an array indicating the slots and corresponding modes of operation.

[0086] In some aspects, the SFI 220 can be broadcast in a SCI message. The UE 215-a can transmit the SFI 220 in a separate (e.g., dedicated) second stage SCI (SCI-2) message. Additionally or alternatively, the UE 215-a can append the SFI 220 to another SCI-2 message when the same modulation and coding scheme (MCS) can be used to save cyclic redundancy check (CRC) bits. In some aspects, the SFI 220 can be carried directly in a first stage (SCI-1) message, such as in a bandwidth of legacy (e.g., LTE) devices. The SCI-1 message can include an identifier of the star topology and an indication of the SFI 220 to enable early detection of the SFI 220. In some aspects, the SFI 220 can be broadcast to the peripheral UEs 215 via higher layer signaling (e.g., a MAC control element (MAC-CE) or a radio resource control (RRC) message, among other aspects).

[0087] In some aspects, the base station 205 can transmit a configured grant 230 that schedules transmission occasions for the UEs 215. The central UE 215-a can use the SFI 220 to temporarily invalidate transmission occasions scheduled for the peripheral UEs 215, or to partially invalidate slots of transmission occasions scheduled for blind retransmissions on a set of slots. In one aspect, the SFI 220 can invalidate transmission occasions that schedule transmissions from a peripheral UE 215 (e.g., UE 215-d) to the central UE 215-a in a “forward” slot. Similarly, the SFI 220 can invalidate transmission occasions that schedule transmissions from the central UE 215-a to a peripheral UE 215 (e.g., UE 215-c) in a “reverse” slot. In some aspects, the peripheral UEs 215 can enter a sleep mode in slots with transmissions that are invalidated, where the peripheral UEs 215 can skip blind decodes in the slots.

[0088] In some aspects, the central UE 215-a can operate in an “unavailable” mode in a third group of slots, where the central UE 215-a does not operate in either a transmit mode or a receive mode with respect to the peripheral UEs 215. The peripheral UEs 215 can enter a sleep mode in the “unavailable” slots to conserve power. In some aspects, the central UE 215-a can use the “unavailable” slots to communicate with another device in the wireless communications system 200 (e.g., the base station 205) instead of the peripheral UEs 215. Additionally, or alternatively, the central UE 215-a can switch to another channel for communication or radio resource management (RRM) measurements. In some aspects, the central UE 215-a can power down one or more transmission components (e.g., radios or modems, among other examples) in the “unavailable” slots to conserve power. In some aspects, the SFI 220 can invalidate transmission occasions scheduled by the configured grant 230 in the “unavailable” slots.

[0089] In some aspects, the central UE 215-a can determine the individual operating modes of the frequency subbands of the channels used for sidelink communication 225. In one aspect, the central UE 215-a can determine whether to operate in an "unavailable" mode for one or more subbands based on the limited processing capabilities at the central UE 215-a or for power saving. Based on the individual operating modes, the central UE 215-a can include subband-related dimensions in SFI 220. In some aspects, the central UE 215-a can replicate SFI 220 on multiple sidelink channels leading to each peripheral UE 215. That is, the SFI 220 transmitted on a given sidelink channel can include information for the operating modes of all subbands. Replicating SFI 220 allows the central UE 215-a to schedule sidelink communication 225 for peripheral UEs 215 with reduced capabilities (e.g., bandwidth capability, beamforming capability, etc.) compared to other UEs 215 in the wireless communication system 200, to improve efficiency and provide other benefits. Additionally or alternatively, replicating SFI220 can enable peripheral UE 215 to monitor a portion of the receive resource pool to save power.

[0090] Figure 3 An example of a timing diagram 300 supporting microsleep technology in star topology sidelink communication is shown according to various aspects of this disclosure. In some aspects, timing diagram 300 may be implemented by wireless communications 100 and 200 or may be implemented by aspects of wireless communication systems 100 and 200. Timing diagram 300 may be shown in reference to Figure 1 The operation performed at one or more UEs 115 is described.

[0091] The UE set can be arranged in a star topology, where one UE can act as the central UE of the peripheral UE set, coordinating sidelink communication (e.g., PSCCH, PSSCH, or PSFCH transmissions) within the set of time slots 305. That is, peripheral UEs can send and receive data to and from the central UE in sidelink communication. In some aspects, the roles of the central and peripheral UEs can be dynamically determined based on time-based traffic flows, rather than being fixed.

[0092] According to the techniques described herein, the central UE can broadcast an SFI to the peripheral UEs in slot 305-a to indicate the mode of operation in slot 305. In one aspect, in slot 305-b, the central UE can operate in a “forward” mode, transmitting sidelink communications to the peripheral UEs. Conversely, in slots 305-c and 305-e, the central UE can operate in a “reverse” mode, receiving sidelink communications from the peripheral UEs. In some aspects, if a peripheral UE does not have data or control information to transmit to the central UE, the peripheral UE can enter a sleep mode (e.g., microsleep) in slot 305-c or slot 305-e (or a portion of slot 305-c or slot 305-e) to conserve power. In some aspects, the SFI in slot 305-a can be arranged as an array indicating slots 305 and corresponding modes of operation. In certain cases, a slot 305 (e.g., slot 305-d) within the plurality of slots 305 can be unallocated or empty.

[0093] In some aspects, the central UE can operate in an “unavailable” mode in slot 305-f, in which the central UE does not operate in either a transmit mode or a receive mode with respect to the peripheral UEs. The peripheral UEs can enter a sleep mode in the “unavailable” slot to conserve power. In some aspects, the central UE can use the “unavailable” slot to communicate with another device (e.g., a base station or another UE outside of the star topology, among other examples) instead of communicating with the peripheral UEs. Additionally or alternatively, the central UE can switch to another channel to communicate or perform RRM measurements. In some aspects, the central UE can deactivate one or more transmission components (e.g., radios or modems, among other examples) in the “unavailable” slot to conserve power.

[0094] Based on indicating the mode of operation, the central UE can reduce power consumption and improve reliability of sidelink communications with the peripheral UEs, among other benefits.

[0095] Figure 4 An example of a timing diagram 400 that supports microsleep techniques in star topology sidelink communications is shown, in accordance with aspects of the present disclosure. In some aspects, the timing diagram 400 can be implemented by or can implement aspects of the wireless communications 100 and 200. The timing diagram 400 can illustrate operations performed at one or more of the UEs 115 described with reference to FIGs. 1-3. Figure 1

[0096] ​The UE set can be arranged in a star topology, where one UE can act as the central UE of the peripheral UE set. The central UE can coordinate sidelink communications (e.g., PSCCH, PSSCH, or PSFCH transmissions) within the set of time slots 405. That is, peripheral UEs can send and receive data to and from the central UE in sidelink communications. In some aspects, the roles of the central UE and peripheral UEs can be dynamically determined based on time-based traffic flows, rather than being fixed.

[0097] According to the techniques described herein, the central UE can broadcast an SFI to peripheral UEs to indicate the operating mode in time slot 405. In one aspect, in time slot 405-a, the central UE can operate in "forward" mode, sending sidelink communications to the peripheral UEs. Conversely, in time slot 405-b, the central UE can operate in "reverse" mode, receiving sidelink communications from the peripheral UEs. In some aspects, if the peripheral UEs have no data or control information to send to the central UE, they can enter a sleep mode (e.g., microsleep) in time slot 405-b (or a portion of time slot 405-b) to conserve power. In some aspects, one or more time slots 405 (e.g., time slot 405-d) can be empty.

[0098] In some aspects, the central UE can indicate the corresponding operating mode for the feedback timing 410 in time slot 405 (e.g., time slots 405-c and 405-e). In one aspect, in time slot 405 operating in "forward" mode, the central UE can send feedback to peripheral UEs (e.g., HARQ feedback in PSFCH transmission), but miss feedback sent by peripheral UEs. Similarly, in time slot 405 operating in "reverse" mode, the central UE can receive feedback from peripheral UEs, but cannot send feedback to peripheral UEs. In some aspects, the central UE can determine the operating mode of time slot 405 based on scheduling feedback in the feedback timing 410 of time slot 405. The feedback timing 410 can be scheduled periodically in time slot 405 (e.g., every two time slots 405). The feedback timing 410 can be scheduled in the resources of time slot 405 according to FDM technology.

[0099] like Figure 4 As shown, the peripheral UE can be scheduled to send feedback in feedback timing 410-a within time slot 405-c, where the feedback corresponds to the forward transmission in time slot 405-a. Similarly, the central UE can be scheduled to send feedback in feedback timing 410-b within time slot 405-c, where the feedback corresponds to the reverse transmission from the peripheral UE in time slot 405-b.

[0100] In some aspects, the slot 405-c can be configured by the central UE to have a “reverse” or “unavailable” mode of operation. A peripheral UE waiting for feedback in the feedback occasion 410-b can be configured to interpret the pending feedback as a HARQ negative acknowledgement (NACK) response. That is, if the peripheral UE detects the feedback occasion 410-b in a slot that is not configured by the SFI to carry “forward” mode traffic, the peripheral UE can interpret the feedback occasion 410-b as a NACK response. Additionally, or alternatively, the peripheral UE can attempt to receive the pending feedback at a fall-back feedback occasion 410-f in the slot 405-f (e.g., in the next feedback occasion that falls on a “forward” slot). If the fall-back feedback occasion 410-f is also configured as a “reverse” or “unavailable” mode of operation, the feedback occasion 410-f can be interpreted as carrying a NACK response.

[0101] In some aspects, the slot 405-c can be configured by the central UE to have a “forward” or “unavailable” mode of operation. A peripheral UE configured to transmit feedback in the feedback occasion 410-a can assume that the central UE receives a HARQ NACK response in the feedback occasion 410-a. Additionally, or alternatively, the peripheral UE can attempt to transmit the pending feedback at a fall-back feedback occasion 410-e in the slot 405-f. If the fall-back feedback occasion 410-e is also configured as a “forward” or “unavailable” mode of operation, the peripheral UE can assume that the central UE receives a HARQ NACK response in the feedback occasion 410-e.

[0102] Based on the indicated mode of operation of the slot 405 and the feedback occasion 410, the central UE can reduce power consumption and improve reliability of sidelink communications with the peripheral UE, among other benefits.

[0103] Figure 5 A process flow 500 that supports micro-sleep techniques in star topology sidelink communications is shown in accordance with aspects of the present disclosure. In some aspects, the process flow 500 can be implemented by or can implement aspects of the wireless communications 100 and 200. In one aspect, the process flow 500 can include operations associated with a set of UEs 515, which can be the UEs 515 described with reference to FIGs. 1-4. The process flow 500 can also include operations associated with a central UE 505, which can be the central UE 505 described with reference to FIGs. 1-4. Figure 1 And Figure 2Aspects of the corresponding apparatus are described. In the following description of the process flow 500, the operations between the UEs 515 can be performed in a different order than shown, or the operations performed by the UEs 515 can be performed at different times or in different orders. Some operations can also be omitted from the process flow 500, and other operations can be added to the process flow 500. The operations performed by the UEs 515 can facilitate improvements in efficiency and reliability of sidelink communications between the UEs 515, among other benefits.

[0104] The UEs 515 can communicate with each other in a star topology, which can be referred to as a star network, where the UE 515-a can act as a central UE 515-a that coordinates communications with the UEs 515-b, which can be referred to as peripheral UEs 515-b. That is, the peripheral UEs 515-b can transmit data to and receive data from the central UE 515-a in sidelink communications that are coordinated by the central UE 515-a. In some aspects, the roles of the central UE 515 and the peripheral UEs 515 can be dynamically determined based on temporal traffic flows, rather than being fixed. That is, in some aspects, the UE 515-a can act as a central UE 515 in a first time period, and the UE 515-b can act as a central UE 515 in a second time period. Figure 5 In the illustrated aspects, the UE 515-a can act as a central UE 515, and in another aspect, the UE 515-b can act as a central UE 515 for the set of UEs 515. In some aspects, the star topology can include additional peripheral UEs 515 (not shown).

[0105] At 520, the central UE 515-a can determine respective operating modes for a set of slots for sidelink communications with the peripheral UE 515-b. In one aspect, in a first group of slots, the central UE 515-a can operate in a “forward” mode to transmit sidelink communications to the peripheral UE 515-b. In a second group of slots, the central UE 515-a can operate in a “reverse” mode to receive sidelink communications from the peripheral UE 515-b. In some aspects, the central UE 515-a can operate in an “unavailable” mode in a third group of slots, where the central UE 515-a does not operate in either a transmit mode or a receive mode with respect to the peripheral UE 515-b.

[0106] In some aspects, at 525, the central UE 515-a can generate an array indicating the slots and the corresponding operating modes. The array can include respective elements for a subset of the set of slots or all of the slots. In one aspect, the array can have entries for the set of slots with respective operating modes. Each entry can specify a slot or a range of slots and an operating mode. Thus, the array can be a list of slot numbers (e.g., specified by a number of slots from a reference slot such as a current slot) and corresponding modes.

[0107] In some aspects, at 530, the center UE 515-a can identify a configured grant (CG) that schedules transmission occasions for the UE 515. Based on the determination of the operating mode, the center UE 515-a can temporarily invalidate transmission occasions scheduled for the peripheral UE 515-b, or partially invalidate slots of transmission occasions that schedule blind retransmissions over a set of slots. In one aspect, the center UE 515-a can invalidate transmission occasions that schedule transmissions from the peripheral UE 515-b to the center UE 515-a by configuring the corresponding slots as “forward” mode. Similarly, the center UE 515-a can invalidate transmission occasions that schedule transmissions from the center UE 515-a to the peripheral UE 515-b by configuring the corresponding slots as “reverse” mode.

[0108] At 535, the center UE 515-a can transmit an SFI to the peripheral UE 515-b. In some aspects, the SFI can include the generated array. In some aspects, the center UE 515-a can broadcast the SFI in a SCI message. The center UE 515-a can transmit the SFI in a standalone (e.g., dedicated) SCI-2 message. Additionally or alternatively, the center UE 515-a can append the SFI to another SCI-2 message, where the same MCS can be used (e.g., when the MCS used for the SCI-2 message is compatible with the broadcast of the SFI) to save CRC bits. In some aspects, the SFI can be carried directly in a SCI-1 message, such as in the bandwidth of legacy (e.g., LTE) devices. In one aspect, the SFI can be carried in a new format for the SCI-1 message. The SCI-1 message can include an identifier of the star topology and an indication of the SFI to enable early detection of the SFI. In some aspects, the SFI can be broadcast to the peripheral UE 515-b via higher layer signaling (e.g., MAC-CE or RRC message, among other aspects). In some aspects, the center UE 515-a can include a subband-dependent dimension in the SFI or duplicate the SFI on multiple sidelink channels.

[0109] In some aspects, at 540, the center UE 515-a can transmit a feedback indication to the peripheral UE 515-b. The feedback indication can schedule resources for a feedback occasion corresponding to the set of slots. In some aspects, the feedback occasion can be scheduled in resources of the slots according to a FDM technique.

[0110] At 545, the peripheral UE 515-b can determine an operating mode based on the SFI. In some aspects, at 550, the peripheral UE 515-b can enter a sleep mode (e.g., microsleep) in one or more slots to conserve power. In one aspect, the peripheral UE 515-b can enter the sleep mode in slots (or portions of slots) when the central UE 515-a operates in an “unavailable” mode, or slots when the central UE 515-a operates in a “reverse” mode and the peripheral UE 515-b has no data or control information to transmit to the central UE 515-a.

[0111] At 555, the UE 515 can communicate sidelink communications in the set of slots in accordance with the indicated operating modes. In some aspects, the sidelink communications can include PSCCH transmissions, PSSCH transmissions, or any combination thereof. In some aspects, at 560, the UE 515 can communicate feedback in a feedback occasion scheduled by the central UE 515-a. Based on the indicated operating modes for the slots and the feedback occasion, the central UE 515-a can reduce power consumption and improve reliability of sidelink communications with the peripheral UE 515-b, among other benefits.

[0112] Figure 6 A block diagram 600 of a device 605 that supports microsleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The device 605 can be an example of aspects of a UE 115 as described herein. The device 605 can include a receiver 610, a communications manager 615, and a transmitter 620. The device 605 can also include a processor. Each of these components can be in communication with one another (e.g., via one or more buses).

[0113] The receiver 610 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to microsleep techniques in star topology sidelink communications, etc.). Information can be passed on to other components of the device 605. The receiver 610 can be Figure 9 The described receiver 610 can be an example of aspects of the transceiver 920 described with reference to FIG. 9. The receiver 610 can utilize a single antenna or a set of antennas.

[0114] In some aspects, the communications manager 615 can determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes, transmit, to a second set of UEs, a slot format indication for the set of slots indicating the respective operating modes, and communicate, with one or more second UEs of the second set of UEs, in one or more slots of the set of slots based on transmitting the slot format indication.

[0115] In some aspects, the communication manager 615 can receive, from a first UE, a slot format indication indicating respective operating modes for sidelink communications in a set of slots, each operating mode selected from a set of operating modes, determine, based on receiving the slot format indication, a first operating mode corresponding to a first subset of the set of slots and a second operating mode corresponding to a second subset of the set of slots, and communicate with the first UE in one or more slots of the set of slots based on determining the first operating mode and the second operating mode.

[0116] The communication manager 615 described herein can be implemented to realize one or more potential advantages. One implementation can allow the device 605 to save power by more efficiently communicating with UEs 115 (e.g., as shown in FIG. 1) in sidelink communications. For example, the device 605 can improve reliability of communications with UEs 115 because the device 605 can be able to determine whether a sidelink transmission is likely to be successful based on determining an operating mode. Using the techniques described herein, the device 605 can more accurately identify slots of a sleep mode, which can improve power efficiency of the device 605. The communication manager 615 can be an example of aspects of the communication manager 910 described herein. Figure 1

[0117] The communication manager 615, or its sub-components, can be implemented in hardware, code (for example, software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615, or its sub-components can be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field- programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0118] The communication manager 615, or its sub-components, can be physically located in various places in the apparatus, including but not limited to with one or more of the processor(s) described in the present disclosure. In some aspects, the communication manager 615, or its sub-components, can be a separate and distinct component in accordance with various aspects of the present disclosure. In some aspects, the communication manager 615, or its sub-components, can be combined with one or more other hardware components, including but not limited to an input / output (I / O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

[0119] The transmitter 620 can transmit signals generated by other components of the device 605. In some aspects, the transmitter 620 can be collocated with a receiver 610 in a transceiver module. In one aspect, the transmitter 620 can be a separate component from the receiver 610. However, it will be appreciated that the transmitter 620 and receiver 610 can be combined in a transceiver module as Figure 9 ​Examples of aspects of the described transceiver 920. The transmitter 620 can utilize a single antenna or a set of antennas.

[0120] Figure 7 A block diagram 700 of a device 705 that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The device 705 can be an example of aspects of a device 605 or a UE 115 as described herein. The device 705 can include a receiver 710, a communications manager 715, and a transmitter 735. The device 705 can also include a processor. Each of these components can be in communication with one another (e.g., via one or more buses).

[0121] The receiver 710 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to micro-sleep techniques in star topology sidelink communications, etc.). Information can be passed on to other components of the device 705. The receiver 710 can be a receiver as described with reference to FIG. 9. Figure 9 Examples of aspects of the described transceiver 920. The receiver 710 can utilize a single antenna or a set of antennas.

[0122] The communications manager 715 can be an example of aspects of the communications manager 615 described herein. The communications manager 715 can include an operational mode manager 720, an SFI manager 725, and a sidelink communications manager 730. The communications manager 715 can be an example of aspects of the communications manager 910 described herein.

[0123] In some aspects, the operational mode manager 720 can determine, for a set of slots, respective operational modes for sidelink communications, each operational mode selected from a set of operational modes. The SFI manager 725 can transmit, to a set of second UEs, a slot format indication for the set of slots indicating the respective operational modes. The sidelink communications manager 730 can communicate, with one or more second UEs of the set of second UEs, in one or more slots of the set of slots based on transmitting the slot format indication.

[0124] In some aspects, the SFI manager 725 can receive, from a first UE, a slot format indication indicating respective operational modes for sidelink communications in a set of slots, each operational mode selected from a set of operational modes. The operational mode manager 720 can determine, based on receiving the slot format indication, a first operational mode corresponding to a first subset of the set of slots and a second operational mode corresponding to a second subset of the set of slots. The sidelink communications manager 730 can communicate, with the first UE, in one or more slots of the set of slots based on determining the first operational mode and the second operational mode.

[0125] Transmitter 735 can transmit signals generated by other components of the device 705. In some aspects, the transmitter 735 can be collocated with a receiver 710 in a transceiver module. In one aspect, the transmitter 735 can be part of a transceiver module. The transmitter 735 can utilize a single antenna or a set of antennas. Figure 9

[0126] Figure 8 A block diagram 800 of a communications manager 805 that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The communications manager 805 can be an example of aspects of a communications manager 615, a communications manager 715, or a communications manager 910 described herein. The communications manager 805 can include an operational mode manager 810, an SFI manager 815, a sidelink communication manager 820, an SCI manager 825, a feedback manager 830, and a sleep mode manager 835. Each of these modules can communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0127] In some aspects, the operational mode manager 810 can determine, for a set of slots, respective operational modes for sidelink communications, each operational mode selected from a set of operational modes. In some aspects, the operational mode manager 810 can identify, based on determining the respective operational modes for the set of slots, a first operational mode corresponding to a first subset of the set of slots and a second operational mode corresponding to a second subset of the set of slots. In some aspects, the operational mode manager 810 can identify, based on determining the respective operational modes for the set of slots, a third operational mode corresponding to a third subset of the set of slots.

[0128] In some aspects, the operational mode manager 810 can identify, based on determining the respective operational modes for the set of slots, a respective operational mode for each slot in a fourth subset. In some aspects, the operational mode manager 810 can determine a respective operational mode for a set of subbands in each slot of the set of slots, where a slot format indication for the set of slots indicates the respective operational mode for the set of subbands.

[0129] In some aspects, the SFI manager 815 can transmit, to a second set of UEs, a slot format indication for the set of slots indicating the respective operational modes. In some aspects, the SFI manager 815 can generate an array indicating the set of slots and the respective operational modes, where the slot format indication includes the array. In some aspects, the SFI manager 815 can transmit the slot format indication in each of a set of sub-channels. In some aspects, the SFI manager 815 can transmit the slot format indication in a MAC-CE, an RRC message, or any combination thereof.

[0130] ​In some aspects, the sidelink communication manager 820 can communicate, with one or more second UEs of the second set of UEs, in one or more slots of the set of slots based on transmitting the slot format indication. In some aspects, the sidelink communication manager 820 can transmit, to a second UE of the second set of UEs, a first sidelink transmission in one or more slots of the first subset based on identifying the first mode of operation. In some aspects, the sidelink communication manager 820 can receive, from a second UE of the second set of UEs, a second sidelink transmission in one or more slots of the second subset based on identifying the second mode of operation.

[0131] In some aspects, the sidelink communication manager 820 can identify a configured grant occasion associated with a slot of the set of slots, where the configured grant occasion schedules a sidelink communication with a second UE of the second set of UEs in the slot. In some aspects, the sidelink communication manager 820 can determine a mismatch between the scheduled sidelink communication and a respective mode of operation for the slot. In some aspects, the sidelink communication manager 820 can refrain from communicating the sidelink communication with the second UE in the slot based on determining the mismatch.

[0132] In some aspects, the sidelink communication manager 820 can refrain from communicating with the second set of UEs in one or more slots of the third subset based on identifying the third mode of operation. In some aspects, the sidelink communication manager 820 can deactivate one or more transmission components at the first UE in one or more slots of the third subset based on identifying the third mode of operation, where refraining from communicating with the second set of UEs in one or more slots of the third subset is further based on deactivating the one or more transmission components.

[0133] In some aspects, the SCI manager 825 can transmit the slot format indication in a sidelink control information message. In some aspects, the SCI manager 825 can identify control information in the sidelink control information message. In some aspects, the SCI manager 825 can append the slot format indication to the control information in the sidelink control information message based on determining that a modulation and coding scheme for the sidelink control information message is compatible with transmitting the slot format indication.

[0134] In some aspects, the feedback manager 830 can transmit, to the second set of UEs, a feedback indication that indicates a fourth subset of the set of slots for feedback associated with sidelink communications. In some aspects, the feedback manager 830 can communicate feedback with one or more second UEs of the second set of UEs in one or more slots of the fourth subset based on transmitting the feedback indication and identifying a respective mode of operation.

[0135] In some aspects, the operation mode manager 810 can determine, based on receiving the slot format indication, a first operation mode corresponding to a first subset of the set of slots and a second operation mode corresponding to a second subset of the set of slots. In some aspects, the operation mode manager 810 can determine, based on receiving the slot format indication, a third operation mode corresponding to a third subset of the set of slots. In some aspects, the operation mode manager 810 can identify, based on receiving the slot format indication, a respective operation mode for each slot in a fourth subset.

[0136] In some aspects, the SFI manager 815 can receive, from a first UE, a slot format indication indicating respective operation modes for sidelink communications in a set of slots, each operation mode selected from a set of operation modes. In some aspects, the SFI manager 815 can identify an array indicating the set of slots and the respective operation modes, where the slot format indication includes the array. In some aspects, the SFI manager 815 can receive the slot format indication in one or more of a set of subchannels. In some aspects, the SFI manager 815 can receive the slot format indication in a MAC-CE, a RRC message, or any combination thereof. In some cases, the slot format indication indicates a respective operation mode for a set of subbands in each slot in the set of slots.

[0137] In some aspects, the sidelink communication manager 820 can communicate with the first UE in one or more slots of the set of slots based on determining the first operation mode and the second operation mode. In some aspects, the sidelink communication manager 820 can receive a first sidelink transmission from the first UE in one or more slots of the first subset based on determining the first operation mode. In some aspects, the sidelink communication manager 820 can transmit a second sidelink transmission to the first UE in one or more slots of the second subset based on determining the second operation mode. In some aspects, the sidelink communication manager 820 can refrain from communicating with the first UE in at least a portion of the slots of the second subset based on entering the sleep mode.

[0138] In some aspects, the sidelink communication manager 820 can identify a configured grant occasion associated with a slot of the set of slots, where the configured grant occasion schedules a sidelink communication with the first UE in the slot. In some aspects, the sidelink communication manager 820 can determine a mismatch between the scheduled sidelink communication and a respective operation mode for the slot. In some aspects, the sidelink communication manager 820 can refrain from transmitting the sidelink communication with the first UE in the slot based on determining the mismatch. In some aspects, the sidelink communication manager 820 can refrain from decoding the sidelink communication with the first UE in the slot based on determining the mismatch.

[0139] In some aspects, the sidelink communication manager 820 can refrain from communicating with the first UE in at least a portion of the slots of the third subset based on entering the sleep mode.

[0140] In some aspects, the SCI manager 825 can receive, in the sidelink control information message, an indication of a slot format indication. In certain cases, the sidelink control information message includes an indication of the slot format indication and a network identifier associated with the first UE and the set of second UEs. In certain cases, the sidelink control information message includes an indication of the slot format indication and a network identifier associated with the first UE and the second UE.

[0141] In some aspects, the feedback manager 830 can receive, from the first UE, a feedback indication indicating a fourth subset of the set of slots for feedback associated with the sidelink communication. In some aspects, the feedback manager 830 can transmit, with the first UE, feedback in one or more slots of the fourth subset based on receiving the feedback indication and identifying the respective operating mode. In some aspects, the feedback manager 830 can refrain from transmitting, with the first UE, feedback in a first slot of the fourth subset based on identifying the respective operating mode of the first slot. In some aspects, the feedback manager 830 can transmit, with the first UE, feedback in a second slot of the fourth subset based on identifying the respective operating mode of the second slot.

[0142] In some aspects, the sleep mode manager 835 can enter a sleep mode in at least a portion of the slots of the second subset based on determining the second operating mode. In some aspects, the sleep mode manager 835 can enter the sleep mode in the slot based on determining the mismatch, wherein refraining from communicating with the first UE in the slot is further based on entering the sleep mode. In some aspects, the sleep mode manager 835 can enter a sleep mode in at least a portion of the slots of the third subset based on determining the third operating mode.

[0143] Figure 9 A diagram illustrating a system 900 including a device 905 that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The device 905 can be an example of or include the components of device 605, device 705, or a UE 115 as described herein. The device 905 can include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communication manager 910, an I / O controller 915, a transceiver 920, an antenna 925, memory 930, and a processor 940. These components can be in electronic communication via one or more buses (e.g., bus 945).

[0144] In some aspects, the communication manager 910 can determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes, transmit, to a set of second UEs, a slot format indication for the set of slots indicating the respective operating modes, and communicate with one or more second UEs of the set of second UEs in one or more slots of the set of slots based on transmitting the slot format indication.

[0145] In some aspects, the communication manager 910 can receive, from a first UE, a slot format indication indicating respective operating modes for sidelink communications in a set of slots, each operating mode selected from a set of operating modes, determine, based on receiving the slot format indication, a first operating mode corresponding to a first subset of the set of slots and a second operating mode corresponding to a second subset of the set of slots, and communicate with the first UE in one or more slots of the set of slots based on determining the first operating mode and the second operating mode.

[0146] The I / O controller 915 can manage input and output signals for the device 905. The I / O controller 915 can also manage peripherals not integrated into the device 905. In some cases, the I / O controller 915 can represent a physical connection or port to or another well-known operating system. In other cases, the I / O controller 915 can represent a modem, a keyboard, a mouse, a touchscreen, or similar device or interact with such devices. In some cases, the I / O controller 915 can be implemented as part of a processor. In some cases, a user can interact with the device 905 via the I / O controller 915 or via hardware components controlled by the I / O controller 915.

[0147] The transceiver 920 can include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. As described above, the transceiver 920 can communicate bi-directionally with another wireless transceiver via the one or more antennas, wired, or wireless links. In some aspects, the transceiver 920 can represent a wireless transceiver and can communicate bi-directionally with another wireless transceiver. The transceiver 920 can also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0148] In some cases, the wireless device can include a single antenna 925. However, in some cases the device can have more than one antenna 925, which can be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0149] The memory 930 can include random access memory (RAM) and read-only memory (ROM). The memory 930 can store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 930 can contain, among other things, a basic input / output system (BIOS) which can

[0150] The processor 940 can include an intelligent hardware device, (e.g., a general- purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 940 can be configured to operate a memory array using a memory controller. In other cases, a memory controller can be integrated into the processor 940. The processor 940 can be configured to execute computer-readable instructions stored in a memory (e.g., the memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks supporting micro-sleep techniques in star topology sidelink communications).

[0151] According to the techniques described herein, the processor 940 of the device 905 (e.g., controlling the receiver 610, the transmitter 620, or the transceiver 920) can reduce power consumption and increase sidelink transmission reliability. In some aspects, the processor 940 of the device 905 can adjust sidelink communications based on determining an operating mode. For example, the processor 940 of the device 905 can turn on one or more processing units used to identify the operating mode, increase a processing clock, or similar mechanisms within the device 905. Thus, when a subsequent sidelink communication is scheduled, the processor 940 can more accurately identify time slots for sleep modes. Improvements in scheduling can result in improvements in power savings and sidelink communication reliability, which can further improve power efficiency at the device 905 (e.g., by eliminating unnecessary repeated sidelink communications, identifying time slots for sleep modes, etc.).

[0152] The code 935 can include instructions to implement aspects of the present disclosure including instructions to support wireless communications. The code 935 can be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 935 can not be directly executable by the processor 940 but can cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0153] Figure 10A flow diagram illustrating a method 1000 that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The operations of method 1000 can be implemented by a UE 115 or its components as described herein. In one aspect, the operations of method 1000 can be performed by a UE 115 as described with reference to FIGS. 1-2 by a communications manager 650 described with reference to FIGS. 5-6. Additionally or alternatively, the operations of method 1000 can be performed by a processor or processing system, such as the processing system 1010 of the UE 115 described with reference to FIG. 10, or the processing system 810 of the base station 105 described with reference to FIG. 8. Figures 6 to 9 The communications manager described with reference to FIGS. 5-6. In some aspects, a first UE can execute a set of instructions to control its functional elements to perform the functions described below. Additionally or alternatively, the first UE can perform aspects of the functions described below using special-purpose hardware.

[0154] At 1005, the first UE can determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes. The operations of 1005 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1005 can be performed by an operating mode manager as described with reference to FIGS. 5-6. Figures 6 to 9 The operating mode manager described with reference to FIGS. 5-6.

[0155] At 1010, the first UE can transmit, to a set of second UEs, a slot format indication for the set of slots indicating the respective operating modes. The operations of 1010 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1010 can be performed by an SFI manager as described with reference to FIGS. 5-6. Figures 6 to 9 The SFI manager described with reference to FIGS. 5-6.

[0156] At 1015, the first UE can communicate with one or more second UEs of the set of second UEs in one or more slots of the set of slots based on transmitting the slot format indication. The operations of 1015 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1015 can be performed by a sidelink communications manager as described with reference to FIGS. 5-6. Figures 6 to 9 The sidelink communications manager described with reference to FIGS. 5-6.

[0157] Figure 11 A flow diagram illustrating a method 1100 that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The operations of method 1100 can be implemented by a UE 115 or its components as described herein. In one aspect, the operations of method 1100 can be performed by a UE 115 as described with reference to FIGS. 1-2 by a communications manager 650 described with reference to FIGS. 5-6. Additionally or alternatively, the operations of method 1100 can be performed by a processor or processing system, such as the processing system 1010 of the UE 115 described with reference to FIG. 10, or the processing system 810 of the base station 105 described with reference to FIG. 8. Figures 6 to 9 The communications manager described with reference to FIGS. 5-6. In some aspects, a first UE can execute a set of instructions to control its functional elements to perform the functions described below. Additionally or alternatively, the first UE can perform aspects of the functions described below using special-purpose hardware.

[0158] At 1105, the first UE can determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes. The operations of 1105 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1105 can be performed by an operating mode manager as described with reference to Figures 6 to 9 FIG. 15.

[0159] At 1110, the first UE can generate an array indicating the set of slots and the respective operating modes. The operations of 1110 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1110 can be performed by an SFI manager as described with reference to Figures 6 to 9 FIG. 15.

[0160] At 1115, the first UE can transmit, to a set of second UEs, a slot format indication indicating the respective operating modes for the set of slots, wherein the slot format indication includes the array. The operations of 1115 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1115 can be performed by an SFI manager as described with reference to Figures 6 to 9 FIG. 15.

[0161] At 1120, the first UE can communicate with one or more second UEs of the set of second UEs in one or more slots of the set of slots based on transmitting the slot format indication. The operations of 1120 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1120 can be performed by a sidelink communications manager as described with reference to Figures 6 to 9 FIG. 15.

[0162] Figure 12 A flow diagram illustrating a method 1200 that supports micro-sleep techniques in star topology sidelink communications in accordance with aspects of the present disclosure is shown. The operations of method 1200 can be implemented by a UE 115 or its components as described herein. In one aspect, the operations of method 1200 can be performed by a communications manager as described with reference to Figures 6 to 9 FIG. 15. In some aspects, a first UE can execute a set of instructions to control the functional elements of the first UE to perform the functions described below. Additionally or alternatively, the first UE can perform aspects of the functions described below using special-purpose hardware.

[0163] At 1205, the first UE can determine, for a set of slots, respective operating modes for sidelink communications, each operating mode selected from a set of operating modes. The operations of 1205 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1205 can be performed by an operating mode manager as described with reference to Figures 6 to 9 FIG. 15.

[0164] At 1210, the first UE can identify a first operational mode corresponding to a first subset of the set of slots and a second operational mode corresponding to a second subset of the set of slots based on determining the respective operational modes for the set of slots. The operations of 1210 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1210 can be performed by an operational mode manager as described with reference to Figures 6 to 9 FIG. 15.

[0165] At 1215, the first UE can transmit, to the set of second UEs, a slot format indication for the set of slots indicating the respective operational modes. The operations of 1215 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1215 can be performed by an SFI manager as described with reference to Figures 6 to 9 FIG. 15.

[0166] At 1220, the first UE can communicate with one or more second UEs of the set of second UEs in one or more slots of the set of slots based on transmitting the slot format indication. The operations of 1220 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1220 can be performed by a sidelink communications manager as described with reference to Figures 6 to 9 FIG. 15.

[0167] At 1225, the first UE can transmit, to a second UE of the set of second UEs, a first sidelink transmission in one or more slots of the first subset based on identifying the first operational mode. The operations of 1225 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1225 can be performed by a sidelink communications manager as described with reference to Figures 6 to 9 FIG. 15.

[0168] At 1230, the first UE can receive, from a second UE of the set of second UEs, a second sidelink transmission in one or more slots of the second subset based on identifying the second operational mode. The operations of 1230 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1230 can be performed by a sidelink communications manager as described with reference to Figures 6 to 9 FIG. 15.

[0169] Figure 13 A method 1300 that supports micro-sleep techniques in star topology sidelink communications is shown in FIG. 13. The operations of method 1300 can be implemented by a UE 115 or its components as described herein. In one aspect, the operations of method 1300 can be performed by a UE 115 as described with reference to Figures 6 to 9The described communication manager performs. In some aspects, the second UE can execute a set of instructions to control its functional elements to perform the functions described below. Additionally or alternatively, the second UE can perform aspects of the functions described below using special-purpose hardware.

[0170] At 1305, the second UE can receive, from a first UE, a slot format indication indicating respective operating modes for sidelink communications in a set of slots, each operating mode selected from a set of operating modes. The operations of 1305 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1305 can be performed by a slot format indication manager as described with reference to FIGs. 9 through 12. Figures 6 to 9 The described SFI manager performs.

[0171] At 1310, the second UE can determine, based on receiving the slot format indication, a first operating mode corresponding to a first subset of the set of slots and a second operating mode corresponding to a second subset of the set of slots. The operations of 1310 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1310 can be performed by an operating mode manager as described with reference to FIGs. 9 through 12. Figures 6 to 9 The described operating mode manager performs.

[0172] At 1315, the second UE can communicate with the first UE in one or more slots of the set of slots based on determining the first operating mode and the second operating mode. The operations of 1315 can be performed according to the methods described herein. In some aspects, aspects of the operations of 1315 can be performed by a sidelink communication manager as described with reference to FIGs. 9 through 12. Figures 6 to 9 The described sidelink communication manager performs.

[0173] The following provides an overview of aspects of the disclosure:

[0174] Aspect 1 : A method for wireless communication implemented by a first UE, comprising: transmitting, to a set of second UEs, a slot format indication for a set of slots indicating respective operating modes for sidelink communications in the set of slots, each operating mode selected from a set of operating modes; and communicating with one or more second UEs of the set of second UEs in one or more slots of the set of slots based at least in part on transmitting the slot format indication.

[0175] Aspect 2: The method of aspect 1, further comprising: generating an array indicating the set of slots and the respective operating modes, wherein the slot format indication comprises the array.

[0176] Aspect 3: The method of any one of aspects 1 through 2, further comprising: transmitting, to a second UE of the set of second UEs, a first sidelink transmission in one or more slots of a first subset of the set of slots based at least in part on a first operating mode corresponding to the first subset.

[0177] Aspect 4: The method of aspect 3, further comprising: receiving, from a second set of UEs, a second sidelink transmission in one or more slots of a second subset of the set of slots based at least in part on a second operating mode corresponding to the second subset.

[0178] Aspect 5: The method of any of aspects 1-4, wherein transmitting the slot format indication comprises: transmitting the slot format indication in a sidelink control information message.

[0179] Aspect 6: The method of aspect 5, wherein transmitting the slot format indication in the sidelink control information message comprises: appending the slot format indication to control information in the sidelink control information message based at least in part on determining that a modulation and coding scheme used for the sidelink control information message is compatible with transmitting the slot format indication.

[0180] Aspect 7: The method of any of aspects 5-6, wherein the sidelink control information message comprises an indication of the slot format indication and a network identifier associated with the first and second sets of UEs.

[0181] Aspect 8: The method of any of aspects 1-7, further comprising: identifying a configured grant occasion associated with a slot of the set of slots, wherein the configured grant occasion schedules a sidelink communication with a second UE of the second set of UEs in the slot; determining a mismatch between the scheduled sidelink communication and a respective operating mode for the slot; and refraining from transmitting the sidelink communication with the second UE in the slot based at least in part on determining the mismatch.

[0182] Aspect 9: The method of any of aspects 1-8, further comprising: refraining from communicating with the second set of UEs in one or more slots of a third subset of the set of slots based at least in part on a third operating mode corresponding to the third subset.

[0183] Aspect 10: The method of aspect 9, further comprising: deactivating one or more transmission components at the first UE in the one or more slots of the third subset based at least in part on identifying the third operating mode, wherein refraining from communicating with the second set of UEs in the one or more slots of the third subset is further based at least in part on deactivating the one or more transmission components.

[0184] Aspect 11: The method of any of aspects 1-10, further comprising: transmitting, to the second set of UEs, a feedback indication indicating a fourth subset of the set of slots for feedback associated with the sidelink communication; and transmitting the feedback with one or more second UEs of the second set of UEs in one or more slots of the fourth subset based at least in part on a respective operating mode for each slot of the fourth subset and transmitting the feedback indication.

[0185] Aspect 12: The method of any of aspects 1-11, wherein the slot format indication for the set of slots indicates respective operation modes for a set of subbands in each slot in the set of slots.

[0186] Aspect 13: The method of any of aspects 1-12, wherein transmitting the slot format indication comprises: transmitting the slot format indication in each subchannel in the set of subchannels.

[0187] Aspect 14: The method of any of aspects 1-13, wherein transmitting the slot format indication comprises: transmitting the slot format indication in a medium access control control element, a radio resource control message, or any combination thereof.

[0188] Aspect 15: A method for wireless communication implemented by a second UE, comprising: receiving, from a first UE, a slot format indication indicating respective operation modes for sidelink communications in a set of slots, each operation mode selected from a set of operation modes; and based at least in part on receiving the slot format indication, communicating with the first UE in one or more slots of the set of slots based at least in part on a first operation mode corresponding to a first subset of the set of slots and a second operation mode corresponding to a second subset of the set of slots.

[0189] Aspect 16: The method of aspect 15, wherein the slot format indication comprises an array indicating the set of slots and the respective operation modes.

[0190] Aspect 17: The method of any of aspects 15-16, further comprising: receiving, from the first UE, a first sidelink transmission in one or more slots of the first subset based at least in part on the first operation mode.

[0191] Aspect 18: The method of any of aspects 15-17, further comprising: transmitting, to the first UE, a second sidelink transmission in one or more slots of the second subset based at least in part on the second operation mode.

[0192] Aspect 19: The method of any of aspects 15-18, further comprising: entering a sleep mode in at least a portion of the slots of the second subset based at least in part on the second operation mode; and refraining from communicating with the first UE in the at least a portion of the slots of the second subset based at least in part on entering the sleep mode.

[0193] Aspect 20: The method of any of aspects 15-19, wherein receiving the slot format indication comprises: receiving the slot format indication in a sidelink control information message.

[0194] Aspect 21 : The method of aspect 20, wherein the sidelink control information message includes an indication of a slot format indication and a network identifier associated with the first UE and the second UE.

[0195] Aspect 22: The method of any of aspects 15 through 21, further comprising: identifying a configured grant occasion associated with a slot of the set of slots, wherein the configured grant occasion schedules a sidelink communication with the first UE in the slot; determining a mismatch between the scheduled sidelink communication and a respective operating mode for the slot; and refraining from transmitting the sidelink communication with the first UE in the slot based at least in part on determining the mismatch.

[0196] Aspect 23: The method of aspect 22, further comprising: entering a sleep mode in the slot based at least in part on determining the mismatch, wherein refraining from communicating with the first UE in the slot is further based at least in part on entering the sleep mode.

[0197] Aspect 24: The method of any of aspects 22 through 23, wherein refraining from communicating with the first UE in the slot comprises refraining from decoding a sidelink communication with the first UE in the slot based at least in part on determining the mismatch.

[0198] Aspect 25: The method of any of aspects 15 through 24, further comprising: entering a sleep mode in at least a portion of slots of a third subset of the set of slots based at least in part on a third operating mode corresponding to the third subset; and refraining from communicating with the first UE in the at least a portion of slots of the third subset based at least in part on entering the sleep mode.

[0199] Aspect 26: The method of any of aspects 15 through 25, further comprising: receiving, from the first UE, a feedback indication indicating a fourth subset of the set of slots for feedback associated with the sidelink communication; and transmitting the feedback with the first UE in one or more slots of the fourth subset based at least in part on a respective operating mode of each slot of the fourth subset and receiving the feedback indication.

[0200] Aspect 27: The method of aspect 26, wherein transmitting the feedback with the first UE comprises: refraining from transmitting feedback with the first UE in a first slot of the fourth subset based at least in part on a respective operating mode of the first slot; and transmitting feedback with the first UE in a second slot of the fourth subset based at least in part on a respective operating mode of the second slot.

[0201] Aspect 28: The method of any of aspects 15 through 27, wherein the slot format indication indicates a respective operating mode for a set of subbands in each slot of the set of slots.

[0202] Aspect 29: The method of any of aspects 15 through 28, wherein receiving the slot format indication comprises receiving the slot format indication in one or more of the set of sub-channels.

[0203] Aspect 30: The method of any of aspects 15 through 29, wherein receiving the slot format indication comprises receiving the slot format indication in a medium access control control element, a radio resource control message, or any combination thereof.

[0204] Aspect 31: An apparatus for wireless communication implemented by a first UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of aspects 1 through 14.

[0205] Aspect 32: An apparatus for wireless communication implemented by a first UE, comprising at least one means for performing the method of any of aspects 1 through 14.

[0206] Aspect 33: A non-transitory computer-readable medium storing code for wireless communication by a first UE, the code comprising instructions executable by a processor to perform the method of any of aspects 1 through 14.

[0207] Aspect 34: An apparatus for wireless communication implemented by a second UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of aspects 15 through 30.

[0208] Aspect 35: An apparatus for wireless communication implemented by a second UE, comprising at least one means for performing the method of any of aspects 15 through 30.

[0209] Aspect 36: A non-transitory computer-readable medium storing code for wireless communication by a second UE, the code comprising instructions executable by a processor to perform the method of any of aspects 15 through 30.

[0210] It should be noted that the methods described herein describe possible implementations, and that the operations and the steps can be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods can be combined.

[0211] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems can be described for purposes of example, and it can be contemplated that the techniques described herein are applicable to LTE, LTE-A, LTE-A Pro, or NR networks. In one aspect, the described techniques can be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and others, for which the teachings herein can be adapted to

[0212] Information and signals described herein can be represented using any of a variety of different technologies and techniques. In one aspect, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0213] The various illustrative blocks and components described in connection with the disclosure herein can be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor can be a microprocessor, but in the alternative, the processor can be any processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0214] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. In one aspect, due to the nature of software, functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions can also be physically located at various positions, including being distributed as discrete components or other ways serving essentially the same functionality without tangible physical limitations. The features implementing functions can also be physically and functionally distributed across various entities including end stations.

[0215] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium can be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. In one aspect, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0216] As used herein, including in the claims “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of’ or “one or more of’) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” can be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.”

[0217] In the drawings, like reference numerals can be used to denote similar components throughout the several views. Further, various components of the same type can be distinguished by following the convention of placing the primary reference number in the hundreds column and a secondary reference number in the tens column of the reference number. For example, 102, 102a, 102b, and 102c can each refer to different components of the same type. If only the primary reference number is used in the specification, the description is applicable to any one of the components having the same primary reference number.

[0218] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that can be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “superior” over other examples. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0219] The description herein is presented to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for wireless communication implemented by a first user equipment (UE), comprising: processor, A memory coupled to the processor; as well as Instructions, which are stored in the memory and can be executed by the processor, to cause the device to: Send a time slot format indication for a time slot set to a second set of UEs, the time slot format indication being used for a corresponding operating mode for side link communication in the time slot set, each operating mode being selected from a set of operating modes; At least in part, based on a first operating mode corresponding to a first subset of the time slot set, a first sidelink transmission is sent to a second UE in the second UE set in one or more time slots of the first subset; At least in part, based on a second operating mode corresponding to a second subset of the time slot set, a second side link transmission is received from a second UE in the second UE set in one or more time slots of the second subset; as well as In at least a portion of the time slots in the second subset, at least one second UE in the second UE set enters a sleep mode, and the first UE does not communicate with the at least one second UE.

2. The apparatus of claim 1, wherein the instructions are further executable by the processor to cause the apparatus to: Generate an array indicating the set of time slots and the corresponding operating modes, wherein the time slot format indication includes the array.

3. The apparatus of claim 1, wherein the instructions are further executable by the processor to cause the apparatus to: The time slot format indication is sent in the side link control information message.

4. The apparatus of claim 3, wherein the instructions are further executable by the processor to cause the apparatus to: The control information in the side link control information message is appended with the time slot format indication, at least in part, based on the determination that the modulation and decoding scheme used for the side link control information message is compatible with the transmission time slot format indication.

5. The apparatus of claim 3, wherein the sidelink control information message includes an indication of the time slot format indication and a network identifier associated with the first UE and the second UE set.

6. The apparatus of claim 1, wherein the instructions are further executable by the processor to cause the apparatus to: Based at least in part on a third operating mode corresponding to a third subset of the time slot set, communication with the second set of UEs is avoided in one or more time slots of the third subset.

7. The apparatus of claim 6, wherein the instructions are further executable by the processor to cause the apparatus to: Based at least in part on identifying the third operating mode, one or more transmission components at the first UE are disabled in one or more time slots in the third subset, wherein the avoidance of communication with the second UE set in one or more time slots in the third subset is also based at least in part on disabling the one or more transmission components.

8. The apparatus of claim 1, wherein the instructions are further executable by the processor to cause the apparatus to: Send a feedback indication to the second set of UEs, the feedback indication indicating a fourth subset of the time slot set for feedback associated with the sidelink communication; and The feedback is transmitted with one or more second UEs in the second UE set in one or more time slots of the fourth subset, based at least in part on the corresponding operating mode for each time slot in the fourth subset and the transmission of the feedback instruction.

9. The apparatus of claim 1, wherein the time slot format indication for the time slot set indicates a corresponding operating mode for a sub-band set in each time slot of the time slot set.

10. The apparatus of claim 1, wherein the instructions are further executable by the processor to cause the apparatus to: The time slot format indication is transmitted in each subchannel of the subchannel set.

11. An apparatus for wireless communication implemented by a second user equipment (UE), comprising: processor, A memory coupled to the processor; as well as Instructions, which are stored in the memory and can be executed by the processor, to cause the device to: The first UE receives a slot format indication, which indicates a corresponding operating mode for sidelink communication in a set of slots, each operating mode being selected from a set of operating modes; At least in part based on a first operating mode, the first sidelink transmission is received from the first UE in one or more time slots in a first subset of the time slot set; At least in part based on the second operating mode, a second sidelink transmission is sent to the first UE in one or more time slots in a second subset of the time slot set; as well as The second UE is operable to enter a sleep mode in at least a portion of time slots in a second subset of time slots corresponding to the second operating mode.

12. The apparatus of claim 11, wherein the time slot format indication includes an array indicating the time slot set and corresponding operating modes.

13. The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to: Based at least in part on determining the second operating mode, entering sleep mode in at least a portion of the time slots in the second subset; and At least in part, based on entering the sleep mode, communication with the first UE is avoided during at least a portion of the time slots in the second subset.

14. The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to: The time slot format indication is received in the side link control information message.

15. The apparatus of claim 14, wherein the sidelink control information message includes an indication of the time slot format indication and a network identifier associated with the first UE and the second UE.

16. The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to: At least in part, based on a third operating mode corresponding to a third subset of the time slot set, a sleep mode is entered in at least a portion of the time slots in the third subset; and Based at least in part on entering the sleep mode, communication with the first UE is avoided in at least a portion of the time slots in the third subset.

17. The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to: Receive a feedback indication from the first UE, the feedback indication indicating a fourth subset of the time slot set for feedback associated with the sidelink communication; and The feedback is transmitted with the first UE in one or more time slots in the fourth subset, based at least in part on the corresponding operating mode of each time slot in the fourth subset and the receipt of the feedback indication.

18. The apparatus of claim 17, wherein the instructions are further executable by the processor to cause the apparatus to: Based at least in part on the corresponding operating mode of the first time slot in the fourth subset, the feedback is avoided from being transmitted with the first UE in the first time slot; and The feedback is transmitted with the first UE in the second time slot, at least in part based on the corresponding operating mode of the second time slot in the fourth subset.

19. The apparatus of claim 11, wherein the time slot format indication indicates a corresponding operating mode for a set of subbands in each time slot of the time slot set.

20. The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to: The time slot format indication is received in one or more sub-channels of the sub-channel set.

21. The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to: The time slot format indication is received in a media access control control element, a radio resource control message, or any combination thereof.

22. A method for wireless communication implemented by a first user equipment (UE), comprising: Send a time slot format indication for a time slot set to a second set of UEs, the time slot format indication indicating a corresponding operating mode for side link communication in the time slot set, each operating mode being selected from a set of operating modes; At least in part, based on a first operating mode corresponding to a first subset of the time slot set, a first sidelink transmission is sent to a second UE in the second UE set in one or more time slots of the first subset; At least in part, based on a second operating mode corresponding to a second subset of the time slot set, a second side link transmission is received from a second UE in the second UE set in one or more time slots of the second subset; as well as In at least a portion of the time slots in the second subset, at least one second UE in the second UE set enters a sleep mode, and the first UE does not communicate with the at least one second UE.

23. The method of claim 22, further comprising: Generate an array indicating the set of time slots and the corresponding operating modes, wherein the time slot format indication includes the array.

24. A method for wireless communication implemented by a second user equipment (UE), comprising: The first UE receives a slot format indication, which indicates a corresponding operating mode for sidelink communication in a set of slots, each operating mode being selected from a set of operating modes; At least in part based on a first operating mode, the first sidelink transmission is received from the first UE in one or more time slots in a first subset of the time slot set; At least in part based on the second operating mode, a second sidelink transmission is sent to the first UE in one or more time slots in a second subset of the time slot set; as well as The second UE is operable to enter a sleep mode in at least a portion of time slots in a second subset of time slots corresponding to the second operating mode.

25. The method of claim 24, further comprising: Identify an array that indicates the set of time slots and the corresponding operating modes, wherein the time slot format indication includes the array.

26. A computer-readable medium storing program code, wherein the program code is executable by one or more processors of a user equipment (UE) to cause the processor to perform the method of any one of claims 22-23.

27. An apparatus for performing wireless communication on a user equipment (UE), the apparatus comprising means for performing the method of any one of claims 24-25.

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