Patent Publication Number: US-11381367-B2

Title: System and method for self-contained subslot bundling

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application of U.S. application Ser. No. 15/703,867, entitled “SYSTEM AND METHOD FOR SELF-CONTAINED SUB SLOT BUNDLING” and filed on Sep. 13, 2017, which claims the benefit of U.S. Provisional Application Ser. No. 62/435,028, entitled “SELF-CONTAINED SUBSLOT BUNDLING” and filed on Dec. 15, 2016. U.S. application Ser. No. 15/703,867 and 62/435,028 are expressly incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates generally to communication systems, and more particularly, to a base station that may configure one or more subframes with a configuration that includes two or more subslots. 
     Introduction 
     Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. 
     These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. 
     SUMMARY 
     The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may configure x subframes with a subslot configuration that includes y subslots, y being greater than x. In an aspect, each subslot of the y subslots may include a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying acknowledgment (ACK)/negative acknowledgment (NACK) information associated with the first portion. In an aspect, the second portion may be between the first portion and the third portion. In an aspect, the second portion and the third portion may include at most one symbol. The apparatus may send information indicating the subslot configuration to at least one neighboring base station. The apparatus may communicate content with a user equipment during at least one of they subslots. In an aspect, a number of symbols in the first portion may be configurable based at least in part on the content to be communicated. In an aspect, the first portion of a first subslot of they subslots includes a different number of the one or more symbols than the first portion of a second subslot of they subslots. In an aspect, a sub slot of they sub slots may cross a subframe boundary. In an aspect, the apparatus may puncture data or control information associated with enhanced mobile broadband (eMBB) with the content, and the content may be associated with ultra-reliable low-latency communication (URLLC). In an aspect, the apparatus may cause at least one other base station to reduce transmission power during the y subslots, wherein the at least one other base station is at least a two-hop neighbor of the base station. 
     To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network. 
         FIGS. 2A, 2B, 2C, and 2D  are diagrams illustrating examples of a DL frame structure, DL channels within the DL frame structure, an UL frame structure, and UL channels within the UL frame structure, respectively. 
         FIG. 3  is a diagram illustrating an example of a base station and user equipment (UE) in an access network. 
         FIG. 4  is a diagram of an example wireless communications system. 
         FIG. 5  is a diagram of an example subframe structure. 
         FIG. 6  is a diagram of an example subslot configuration. 
         FIG. 7  is a diagram of an example subslot configuration. 
         FIG. 8  is a diagram of an example subslot configuration. 
         FIG. 9A  is a flowchart of an example method of wireless communication. 
         FIG. 9B  is a flowchart of an example method of wireless communication. 
         FIG. 10  is a conceptual data flow diagram illustrating the data flow between different means/components in an exemplary apparatus. 
         FIG. 11  is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. 
     By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. 
     Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 
       FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network  100 . The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations  102 , UEs  104 , and an Evolved Packet Core (EPC)  160 . The base stations  102  may include macro cells (high power cellular base station) and/or small cells (low power cellular base station). The macro cells include base stations. The small cells include femtocells, picocells, and microcells. 
     The base stations  102  (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) interface with the EPC  160  through backhaul links  132  (e.g., S1 interface). In addition to other functions, the base stations  102  may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations  102  may communicate directly or indirectly (e.g., through the EPC  160 ) with each other over backhaul links  134  (e.g., X2 interface). The backhaul links  134  may be wired or wireless. 
     The base stations  102  may wirelessly communicate with the UEs  104 . Each of the base stations  102  may provide communication coverage for a respective geographic coverage area  110 . There may be overlapping geographic coverage areas  110 . For example, the small cell  102 ′ may have a coverage area  110 ′ that overlaps the coverage area  110  of one or more macro base stations  102 . A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links  120  between the base stations  102  and the UEs  104  may include uplink (UL) (also referred to as reverse link) transmissions from a UE  104  to a base station  102  and/or downlink (DL) (also referred to as forward link) transmissions from a base station  102  to a UE  104 . The communication links  120  may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations  102 /UEs  104  may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100 MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). 
     Certain UEs  104  may communicate with each other using device-to-device (D2D) communication link  192 . The D2D communication link  192  may use the DL/UL WWAN spectrum. The D2D communication link  192  may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. 
     The wireless communications system may further include a Wi-Fi access point (AP)  150  in communication with Wi-Fi stations (STAs)  152  via communication links  154  in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs  152 /AP  150  may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. 
     The small cell  102 ′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell  102 ′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP  150 . The small cell  102 ′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. 
     The gNodeB (gNB)  180  may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with the UE  104 . When the gNB  180  operates in mmW or near mmW frequencies, the gNB  180  may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band has extremely high path loss and a short range. The mmW base station  180  may utilize beamforming  184  with the UE  104  to compensate for the extremely high path loss and short range. 
     The EPC  160  may include a Mobility Management Entity (MME)  162 , other MMES  164 , a Serving Gateway  166 , a Multimedia Broadcast Multicast Service (MBMS) Gateway  168 , a Broadcast Multicast Service Center (BM-SC)  170 , and a Packet Data Network (PDN) Gateway  172 . The MME  162  may be in communication with a Home Subscriber Server (HSS)  174 . The MME  162  is the control node that processes the signaling between the UEs  104  and the EPC  160 . Generally, the MME  162  provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway  166 , which itself is connected to the PDN Gateway  172 . The PDN Gateway  172  provides UE IP address allocation as well as other functions. The PDN Gateway  172  and the BM-SC  170  are connected to the IP Services  176 . The IP Services  176  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC  170  may provide functions for MBMS user service provisioning and delivery. The BM-SC  170  may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway  168  may be used to distribute MBMS traffic to the base stations  102  belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. 
     The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station  102  provides an access point to the EPC  160  for a UE  104 . Examples of UEs  104  include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a display, or any other similar functioning device. Some of the UEs  104  may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE  104  may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. 
     Referring again to  FIG. 1 , in certain aspects, the base station  102  may configure one or more subframes with a subslot configuration  198  that includes one or more subslots. In other words, the base station  102  may configure x subframes with a subslot configuration that includes y subslots. In an aspect, y may be greater than x. Each of the y subslots may include three portions: a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying acknowledgement (ACK)/negative acknowledgement (NACK) information associated with the first portion. In an aspect, the second portion may be between the first portion and the third portion. In an aspect, the second portion and the third portion may be at most one symbol. 
     The base station  102  may be configured to communicate content (e.g., data or control information) with a UE  104  during the y subslots of the subslot configuration  198 . The base station  102  may communicate at least two types of content, a first of which may be associated with enhanced mobile broadband (eMBB) and a second of which may be associated with ultra-reliable low-latency communication (URLLC). In an aspect, the base station  102  may puncture data or control information associated with eMBB with content that is associated with URLLC and may communicate the content associated with URLLC with the UE  104 . 
     In an aspect, the base station  102  may configure a number of symbols in the first portion of one or more subslots based at least in part on the URLLC content that is to be communicated with the UE  104 . In an aspect, the base station  102  may configure a number of symbols in a first portion of a first subslot to be different from a number of symbols in a first portion of a second subslot. That is, the subslot configuration  198  may include a plurality of subslots, but those plurality of subslots do not necessarily include the same number of symbols during a respective first portion. In an aspect, the base station  102  may configure the subslot configuration  198  such that at least one subslot of the y subslots crosses a subframe boundary. 
     In order to improve communication of URLLC content (e.g., interference mitigation), the base station  102  may send information indicating the subslot configuration  198  to a first neighboring base station  180   a . The first neighboring base station  180   a  may be a one-hop neighbor or first-ring neighbor with respect to the base station  102 . The base station  102  may send the information indicating the subslot configuration  198  to the first neighboring base station  180   a  using a backhaul link  134 . 
     Further, the base station  102  may improve communication of URLLC content (e.g., interference mitigation) by causing a second neighboring base station  180   b  to reduce transmission power during the y subslots. In an aspect, the second neighboring base station  180   b  may be at least a two-hop neighbor with respect to the base station  102 . In an aspect, the first neighboring base station  180   a  may send information indicating that the second neighboring base station  180   b  is to reduce transmission power at least during the y subslots, for example, based on the subslot configuration  198  received from the base station  102 . For example, the first neighboring base station  180   a  may send, using the backhaul link  134 , an indication that the second neighboring base station  180   b  is to perform power fallback at least during one or more subframes configured with one or more subslots. 
       FIG. 2A  is a diagram  200  illustrating an example of a DL frame structure.  FIG. 2B  is a diagram  230  illustrating an example of channels within the DL frame structure.  FIG. 2C  is a diagram  250  illustrating an example of an UL frame structure.  FIG. 2D  is a diagram  280  illustrating an example of channels within the UL frame structure. Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent the two time slots, each time slot including one or more time concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)). The resource grid is divided into multiple resource elements (REs). For a normal cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols (for DL, OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme. 
     As illustrated in  FIG. 2A , some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation at the UE. The DL-RS may include cell-specific reference signals (CRS) (also sometimes called common RS), UE-specific reference signals (UE-RS), and channel state information reference signals (CSI-RS).  FIG. 2A  illustrates CRS for antenna ports  0 ,  1 ,  2 , and  3  (indicated as R 0 , R 1 , R 2 , and R 3 , respectively), UE-RS for antenna port  5  (indicated as R 5 ), and CSI-RS for antenna port  15  (indicated as R). 
       FIG. 2B  illustrates an example of various channels within a DL subframe of a frame. The physical control format indicator channel (PCFICH) is within symbol  0  of slot  0 , and carries a control format indicator (CFI) that indicates whether the physical downlink control channel (PDCCH) occupies 1, 2, or 3 symbols ( FIG. 2B  illustrates a PDCCH that occupies 3 symbols). The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCH may have 2, 4, or 8 RB pairs ( FIG. 2B  shows two RB pairs, each subset including one RB pair). The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) is also within symbol  0  of slot  0  and carries the HARQ indicator (HI) that indicates HARQ acknowledgement (ACK)/negative ACK (NACK) feedback based on the physical uplink shared channel (PUSCH). The primary synchronization channel (PSCH) may be within symbol  6  of slot  0  within subframes  0  and  5  of a frame. The PSCH carries a primary synchronization signal (PSS) that is used by a UE  104  to determine subframe/symbol timing and a physical layer identity. The secondary synchronization channel (SSCH) may be within symbol  5  of slot  0  within subframes  0  and  5  of a frame. The SSCH carries a secondary synchronization signal (SSS) that is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSCH and SSCH to form a synchronization signal (SS) block. The MIB provides a number of RBs in the DL system bandwidth, a PHICH configuration, and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. 
     As illustrated in  FIG. 2C , some of the REs carry demodulation reference signals (DM-RS) for channel estimation at the base station. The UE may additionally transmit sounding reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. 
       FIG. 2D  illustrates an example of various channels within an UL subframe of a frame. A physical random access channel (PRACH) may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial system access and achieve UL synchronization. A physical uplink control channel (PUCCH) may be located on edges of the UL system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI. 
       FIG. 3  is a block diagram of a base station  310  in communication with a UE  350  in an access network. In the DL, IP packets from the EPC  160  may be provided to a controller/processor  375 . The controller/processor  375  implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor  375  provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     The transmit (TX) processor  316  and the receive (RX) processor  370  implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor  316  handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator  374  may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE  350 . Each spatial stream may then be provided to a different antenna  320  via a separate transmitter  318 TX. Each transmitter  318 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     At the UE  350 , each receiver  354 RX receives a signal through its respective antenna  352 . Each receiver  354 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor  356 . The TX processor  368  and the RX processor  356  implement layer 1 functionality associated with various signal processing functions. The RX processor  356  may perform spatial processing on the information to recover any spatial streams destined for the UE  350 . If multiple spatial streams are destined for the UE  350 , they may be combined by the RX processor  356  into a single OFDM symbol stream. The RX processor  356  then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station  310 . These soft decisions may be based on channel estimates computed by the channel estimator  358 . The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station  310  on the physical channel. The data and control signals are then provided to the controller/processor  359 , which implements layer 3 and layer 2 functionality. 
     The controller/processor  359  can be associated with a memory  360  that stores program codes and data. The memory  360  may be referred to as a computer-readable medium. In the UL, the controller/processor  359  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC  160 . The controller/processor  359  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     Similar to the functionality described in connection with the DL transmission by the base station  310 , the controller/processor  359  provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     Channel estimates derived by a channel estimator  358  from a reference signal or feedback transmitted by the base station  310  may be used by the TX processor  368  to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor  368  may be provided to different antenna  352  via separate transmitters  354 TX. Each transmitter  354 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     The UL transmission is processed at the base station  310  in a manner similar to that described in connection with the receiver function at the UE  350 . Each receiver  318 RX receives a signal through its respective antenna  320 . Each receiver  318 RX recovers information modulated onto an RF carrier and provides the information to a RX processor  370 . 
     The controller/processor  375  can be associated with a memory  376  that stores program codes and data. The memory  376  may be referred to as a computer-readable medium. In the UL, the controller/processor  375  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE  350 . IP packets from the controller/processor  375  may be provided to the EPC  160 . The controller/processor  375  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
       FIG. 4  is a diagram of a wireless communications system  400 . The wireless communications system  400  may include a plurality of base stations  402 ,  410 ,  414 , each configured to provide a respective cell  408 ,  411 ,  418 . Each of the base stations  402 ,  410 ,  414  may be configured to communicate with one or more UEs  404 ,  406 ,  412 ,  416  operating on the respective cells  408 ,  411 ,  418 . 
     In one aspect, the first base station  402  may be configured to communicate according to eMBB as well as URLLC. In the illustrated aspect, the first base station  402  may communicate with a first UE  404  according to URLLC and, additionally, may communicate with a second UE  406  according to eMBB. The neighboring base stations  410 ,  414  may be configured to communicate according to at least eMBB. According to one or more 3GPP technical specifications, both URLLC and eMBB may be regarded as 5G technologies. 
     In an aspect, the base stations  402 ,  410 ,  414  may be configured to use a NR frame structure at least within a cyclic prefix (CP) overhead. The description of NR frame structure is to be regarded as illustrative, and the present disclosure comprehends other structures or arrangements in addition to those described herein. 
     In one aspect, the reference numerology for a subframe definition may be fourteen (14). For example, the base stations  402 ,  410 ,  414  may be configured to communicate during a subframe that includes fourteen symbols. 
     In an aspect, the NR frame structure may include slots of a duration that is less than the reference numerology for a subframe (e.g., a number of symbols per slot may be fewer than a number of symbols per subframe). In an aspect, an integer number of slots may fit within one subframe duration (e.g., at least for subcarrier spacing that is larger than or equal to the reference numerology). In an aspect, this slot structure may allow for control information at the beginning, end, or both the beginning and end of a slot. The slot configuration may be one possible scheduling unit implemented by the one or more base stations  402 ,  410 ,  414 . 
     In an aspect, the NR frame structure may include a subslot configuration, which may also be known as a “mini-slot” or another naming convention related to a transmission time interval (TTI). The subslot configuration may support transmission time that is shorter than the reference numerology (and, possibly, the slot numerology). For example, the reference numerology for a subframe may be fourteen, and the numerology for a subslot may be less than fourteen (and may be less than the slot numerology, as well). In one aspect, a subslot may be the smallest scheduling unit implemented by one or more base stations  402 ,  410 ,  414 . In one aspect, the subslot configuration may indicate that control information may occur at the beginning of a subslot, the end of a subslot, or both the beginning and the end of a subslot. In one aspect, the slot structure and subslot structure may be merged or, alternatively, the slot configuration may be absent. 
     As indicated, the first base station  402  may communicate URLLC content. In one aspect, URLLC content may be predictable (e.g., periodic), in which case at least one semi-static resource may be reserved for frequency-division multiplexing (FDM) or time-division multiplexing (TDM) of URLLC content with eMBB information. In one aspect, URLLC content may be less predictable (e.g., sporadic), in which case the first base station  402  may be configured to puncture eMBB information with URLLC content. URLLC may require packet delivery to occur with stringent latency constraints and/or relatively low packet error rate. Therefore, interference due to coexistence with other systems may have detrimental consequences to the performance of URLLC. URLLC content may be prioritized over eMBB information and, therefore, the first base station  402  may perform one or more operations in order to mitigate inter-cell interference and improve quality of URLLC communication. 
     According to aspects, the first base station  402  may configure x subframes (including a first subframe  430 ) with a sub slot configuration that includes y sub slots (including a set of subslots  420   a ,  420   b ,  422   a ,  422   b ). In an aspect, y may be greater than x—i.e., the number of subslots may be greater than the number of subframes and, consequently, the duration (e.g., number of symbols) of each subframe may be greater than the duration (e.g., number of symbols) of each sub slot. 
     In the illustrated aspect, a subframe may include fourteen symbols (e.g., the reference numerology); however, the present disclosure contemplates subframe configurations having a different number of the one or more symbols. The first base station  402  may configure a first subframe  430  with a sub slot configuration that includes a plurality of subslots  420   a ,  420   b ,  422   a ,  422   b . For example, the first base station  402  may configure the first subframe  430  to include two subslots  420   a ,  420   b  associated with eMBB. The subslots  420   a ,  420   b  associated with eMBB may carry data or control information associated with eMBB, which may be communicated with the second UE  406 . Additionally, the first base station  402  may configure the first subframe  430  to include two subslots  422   a ,  422   b  associated with URLLC. The subslots  422   a ,  422   b  associated with URLLC may carry data or control information associated with URLLC, which may be communicated with the first UE  404 . 
     Each of they subslots may include three portions: a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying ACK/NACK information associated with the first portion. In an aspect, the second portion may be between the first portion and the third portion. In an aspect, the second portion and the third portion may be at most one symbol. 
     In the illustrated aspect, the first base station  402  may configure a first eMBB subslot  420   a  to include first portion  440   a  that is two symbols, but may configure a second eMBB subslot  420   b  to include a first portion  440   b  that is four symbols. Each of the eMBB subslots  420   a ,  420   b  may include a respective second portion  442   a ,  442   b  having a gap and a respective third portion  444   a ,  444   b  for carrying ACK/NACK information. 
     Similarly, the first base station  402  may configure a first URLLC subslot  422   a  to include first portion  450   a  that is two symbols and may configure a second URLLC subslot  422   b  to include a first portion  450   b  that is also two symbols. Each of the URLLC subslots  422   a ,  422   b  may include a respective second portion  452   a ,  452   b  having a gap and a respective third portion  454   a ,  454   b  for carrying ACK/NACK information. 
     According to this configuration, each subslot  420   a ,  420   b ,  422   a ,  422   b  may be regarded as “self-contained” because each subslot  420   a ,  420   b ,  422   a ,  422   b  includes both a respective first portion  440   a ,  440   b ,  450   a ,  450   b  for carrying data or control information and a respective third portion  444   a ,  444   b ,  454   a ,  454   b  for carrying ACK/NACK information associated with the respective first portion  440   a ,  440   b ,  450   a ,  450   b.    
     While the present disclosure illustrates a specific number of symbols for the set of subslots  420   a ,  420   b ,  422   a ,  422   b , other configurations are possible without departing from the present disclosure. For example, the URLLC subslots  422   a ,  422   b  may include greater or fewer than two symbols and/or may include a different number of the one or more symbols with respect to other URLLC subslots. Furthermore, the first base station  402  may configure a subslot to cross a subframe boundary. 
     The first base station  402  may be configured to communicate content  484  (e.g., data or control information) with the first UE  404  during the URLLC subslots  422   a ,  422   b . In an aspect, the first base station  402  may puncture data or control information associated with eMBB with content  484  that is associated with URLLC and may communicate the content  484  associated with URLLC with the first UE  404 . According to one aspect, the first base station  402  may configure the number of symbols of each first portion  450   a ,  450   b  of each URLLC subslot  422   a ,  422   b  based at least in part on the content  484  to be communicated. For example, the first base station  402  may determine URLLC content to be communicated to the first UE  404  (e.g., based on arrival of one or more URLLC packets from a higher layer) and may determine a number of symbols that are to carry the content. The first base station  402  may configure the first subframe  430  to include the two URLLC subslots  422   a ,  422   b  having respective two-symbol first portions  450   a ,  450   b  based on the content  484  to be communicated to the first UE  404 . 
     In various aspects, the first base station  402  may reconfigure the subslot configuration following the subframe  430 . For example, the first base station  402  may determine that a different number of symbols are to be used to communicate content during a subsequent subframe, for example, because URLLC traffic may be sporadic and/or unpredictable. Consequently, the subslot configuration may not be static, and the first base station  402  may reconfigure the subslot configuration at any time. 
     In order to improve communication of URLLC content (e.g., interference mitigation), the first base station  402  may send information  480  indicating the subslot configuration to a first neighboring base station  410 . The information  480  indicating the subslot configuration may include, for example, a number of subslots, an indication of a number of symbols for a respective first portion of each subslot, or essentially any other information from which the first neighboring base station  410  may derive the subslot configuration implemented by the first base station  402 . 
     Based on the information  480  indicating the subslot configuration, the first neighboring base station  410  may configure x subframes into y subslots. Accordingly, the subslots  460   a ,  460   b ,  460   c ,  460   d  during which the first neighboring base station  410  communicates may be synchronized with the subslots  420   a ,  420   b ,  422   a ,  422   b  during which the first base station  402  communicates. That is, the first neighboring base station  410  may configure boundaries of subslots  460   a ,  460   b ,  460   c ,  460   d  to be synchronized with the boundaries of the subslots  420   a ,  420   b ,  422   a ,  422   b  configured by the first base station  402 . However, the type of data carried in a first portion of the subslots  460   a ,  460   b ,  460   c ,  460   d  of the first neighboring base station  410  may not be synchronized. For example, the first neighboring base station  410  may communicate according to eMBB and not URLLC and, therefore, the first neighboring base station  410  may not include URLLC subslots, such as the URLLC subslots  422   a ,  422   b  configured by the first base station  402 . 
     The first neighboring base station  410  may be a one-hop neighbor or first-ring neighbor with respect to the first base station  402 . In one aspect, a one-hop neighbor or first-ring neighbor may be a base station with which the first base station  402  may communicate without traversing any intervening nodes (e.g., another base station). The first base station  402  may send the information  480  indicating the subslot configuration to the first neighboring base station  410  using a backhaul link (e.g., via the X2 interface). Because the subslot configuration may be reconfigured (e.g., by the first base station  402 ), the first base station  402  and the first neighboring base station  410  may maintain synchronization of subslots. For example, the first base station  402  may send information  480  indicating a subslot configuration each time the first base station  402  reconfigures the subslot configuration. 
     In various aspects, the first base station  402  may improve communication of URLLC content (e.g., interference mitigation) by causing a second neighboring base station  414  to reduce transmission power during the y subslots. In an aspect, the second neighboring base station  414  may be at least a two-hop neighbor with respect to the first base station  402 . In one aspect, a two-hop neighbor or second-ring neighbor may be a base station with which the first base station  402  may communicate by traversing at least one intervening node (e.g., the first neighboring base station  410 ). Because the second neighboring base station  414  is a two-hop neighbor, the first neighboring base station  410  may send the information  482  indicating that the second neighboring base station  414  is to perform power fallback during the subframe  470  that overlaps with URLLC subslots  422   a ,  422   b . The first neighboring base station  410  may send the information  482  over a wireless and/or wired connection, including over the air interface or over a backhaul link. 
     In an aspect, the first neighboring base station  410  may send information  482  indicating that the second neighboring base station  414  is to reduce transmission power at least during at least one of the y subslots, for example, based on the information  480  indicating the subslot configuration received from the first base station  402 . For example, when the first base station  402  sends the information  480  indicating the subslot configuration to the first neighboring base station  410 , the first base station  402  may indicate to the second neighboring base station  414  that the second neighboring base station  414  to perform power fallback during a subframe  470  that overlaps with URLLC subslots  422   a ,  422   b . In an aspect, power fallback may be performed for a portion of the subframe  470 , such as the portion that overlaps with the URLLC subslots  422   a ,  422   b.    
     Based on the information  482  indicating that the second neighboring base station  414  is to perform the power fallback, the second neighboring base station  414  may reduce transmission power during the subframe  470 . This power fallback by the second neighboring base station  414  may avoid a ripple effect in which base stations configure subframes with a subslot configuration that may not be necessary. Additionally, the power fallback may protect an uplink common burst (UCB) channel used in the first neighboring cell  411  (e.g., the UCB channel may carry ACK/NACK information associated with the subslots  460   a ,  460   b ,  460   c ,  460   d ). In an aspect, the second neighboring base station  414  may perform power fallback during a portion of the subframe  470  (rather than during the entire subframe  470 ). 
     The second neighboring base station  414  may, in a subsequent subframe, increase transmission power (e.g., return to a transmission power utilized prior to reception of the information  482  indicating that the second neighboring base station  414  is to perform the power fallback). However, because the subslot configuration may be reconfigured (e.g., by the first base station  402 ), the first base station  402  may cause the second neighboring base station  414  to reduce transmission power in one or more additional subframes, for example, when the first base station  402  sends information  480  indicating a subslot reconfiguration. 
       FIG. 5  illustrates a subframe structure  500 , according to an aspect. The subframe structure  500  may include a self-contained subframe  510 . That is, the self-contained subframe  510  may include a portion  518  for carrying ACK/NACK information. In an aspect, the ACK/NACK information may be carried on an UCB channel. 
     In aspects, a base station may communicate content in a URLLC cell  508  during the self-contained subframe  510 . When a URLLC packet  540  arrives (e.g., from a higher layer), the base station may puncture data or control information associated with eMBB with URLLC content derived from the URLLC packet  540 . For example, the URLLC content from the URLLC packet  540  may be carried in two symbols of a URLLC portion  514  of the self-contained subframe  510 . The corresponding ACK/NACK information  520  for the URLLC content carried in the URLLC portion  514  may occur during the ACK/NACK portion  518  at the end of the self-contained subframe  510 . 
     Because URLLC may adhere to low-latency and/or low-error rate requirements, the URLLC content may be punctured into the self-contained subframe  510  as soon as the URLLC packet  540  arrives. Consequently, an eMBB portion  512   b  may occur between the URLLC portion  514  and the ACK/NACK portion  518 . This intervening eMBB portion  512   b  may lead to an unsatisfactory delay in communicating ACK/NACK information  520 , for example, because a base station would be unaware of the reception status of the URLLC content (communicated in the middle of the self-contained subframe  510 ) until the end of the self-contained subframe  510 . Accordingly, a URLLC cell may benefit from a self-contained subslot configuration. 
       FIG. 6  illustrates a subslot configuration  600 , according to an aspect. In an aspect, an eMBB/URLLC cell  602  (e.g., the first cell  408  provided by the first base station  402 ) may configure x subframes (including the subframe  608 ) with a subslot configuration that includes y subslots (including the self-contained subslot  620 ). At least one subslot may be a self-contained subslot (e.g., the self-contained subslot  620 ). The subslot  620  may be regarded as “self-contained” because the subslot  620  includes at least a first portion  622  for carrying data or control information and a third portion  626  for carrying ACK/NACK information associated with the first portion  622  (n.b., the subslot  620  may include a second portion  624  that is a gap between the first and third portions). That is, the self-contained subslot  620  may include a portion  626  for carrying ACK/NACK information. 
     The subframe  608  configured with the self-contained subslot  620  may include a separate portion  616  for carrying ACK/NACK information (e.g., associated with eMBB data or control information carried in another portion  612  of the subframe). In an aspect, the ACK/NACK information may be carried on a UCB channel. 
     In aspects, a base station may communicate content in a EMBB/URLLC cell  602  during the subframe  608 . When a URLLC packet  640  arrives (e.g., from a higher layer), the base station may puncture data or control information associated with eMBB with URLLC content derived from the URLLC packet  640 . For example, the URLLC content from the URLLC packet  640  may be carried in two symbols of a self-contained subslot  620 . Because URLLC may adhere to low-latency and low-error rate requirements, the URLLC content may be punctured into the self-contained subslot  620  as soon as the URLLC packet  640  arrives. 
     In an eMBB cell  604 , which may neighbor the eMBB/URLLC cell  602 , data or control information associated with eMBB may be communicated during a subframe  606  that overlaps with the self-contained subslot  620 . This eMBB traffic during the eMBB subframe  606  may cause interference  642  to the self-contained subslot  620 . For example, the interference  642  may prevent a base station from receiving and/or decoding ACK/NACK information associated with the first portion  622  of the self-contained subslot  620 . Accordingly, the URLLC (or URLCC/eMBB) cell may benefit when the subslot configuration of the URLLC cell is synchronized with a neighboring cell. For example, interference  642  may be absent during the third portion  626  if the subframe  606  of the eMBB cell  604  is configured so that eMBB data or control information is not communicated during a portion of the subframe  606  that overlaps with the third portion  626  of the self-contained subslot  620 . 
       FIG. 7  illustrates a subslot configuration  700 , according to various aspects. In various aspects, a subframe  702  may be configured in cell (e.g., the first cell  408 , the EMBB/URLLC cell  602 ) based on a reference numerology, such as fourteen. The subframe  702  may include a portion  704  that is to carry data and/or control information, a gap  706 , and a portion  708  that is to carry ACK/NACK information (e.g., on a UCB channel). According to aspects, the subframe  702  may be configured in order to carry data associated with eMBB. 
     In various aspects, a base station (e.g., the first base station  402 ) may configure the subframe  702  into the plurality of subslots  712   a ,  712   b ,  712   c ,  712   d . Each subslot  712  may be configured to include a first portion  714  having one or more symbols for carrying at least one of data or control information. Each subslot  712  may include a second portion  716  having a gap. Each subslot  712  may include a third portion  718  for carrying ACK/NACK information associated with the first portion  714 . The second portion  716  may occur between the first portion  714  and the third portion  718 . In an aspect, the second portion  716  and the third portion  718  may be at most one symbol. 
     The base station may puncture one or more of the subslots  712   a ,  712   b ,  712   c ,  712   d  with URLLC data or control information, for example, when a URLLC packet is received (e.g., from a higher layer). In one aspect, the base station may configure a number of symbols for the first portion  714  based at least in part on URLLC content (e.g., data and/or control information) to be communicated. In an aspect, the base station may configure the number of symbols for the first portion before determining the URLLC content (e.g., before a URLLC packet arrives from a higher layer). Accordingly, the base station may be able to puncture eMBB information with URLLC content as soon as the URLLC content is determined. 
     The base station may send information indicating the subslot configuration  710  to at least one neighboring base station (e.g., the first neighboring base station  410 ). Based on the information indicating the subslot configuration  710 , the neighboring base station may configure at least one subframe to by synchronized with the subslot configuration  710  configured by the base station. Accordingly, the respective first, second, and third portions of subslots in the neighboring cell provided by the neighboring base station may occur contemporaneously with the respective first portions  714   a ,  714   b ,  714   c ,  714   d , second portions  716   a ,  716   b ,  716   c ,  716   d , and third portions  718   a ,  718   b ,  718   c ,  718   d  during which the base station communicates. This synchronization may mitigate interference. For example, the ACK/NACK information carried in the third portions  718   a ,  718   b ,  718   c ,  718   d  may not experience interference  642  from downlink transmissions that occur during the subframe  606  in a neighboring eMBB cell  604 . 
       FIG. 8  illustrates a subslot configuration  800 , according to various aspects. In various aspects, two subframes  806   a ,  806   b  may be configured in cell (e.g., the first cell  408 , the eMBB/URLLC cell  602 ) into a plurality of subslots  810   a ,  810   b ,  810   c ,  810   d ,  810   e ,  810   f ,  810   g.    
     In various aspects, a base station (e.g., the first base station  402 ) may configure the subframes  806   a ,  806   b  into the plurality of subslots  810   a ,  810   b ,  810   c ,  810   d ,  810   e ,  810   f ,  810   g . Each subslot  810  may be configured to include a first portion  812  having one or more symbols for carrying at least one of data or control information. Each subslot  810  may include a second portion  814  having a gap. Each subslot  810  may include a third portion  816  for carrying ACK/NACK information associated with the first portion  812 . The second portion  814  may occur between the first portion  812  and the third portion  816 . In an aspect, the second portion  814  and the third portion  816  may be at most one symbol. In various aspects, the base station may configure the subframes  806   a ,  806   b  with a subslot configuration that crosses a subframe boundary  804 . 
     While the subslots  810   a ,  810   b ,  810   c ,  810   d ,  810   e ,  810   f ,  810   g  are illustrated as each including four symbols, the base station may configure the subframes  806   a ,  806   b  with a subslot configuration in which a subslot has another number of symbols (e.g., two, three, five, seven, etc.). Additionally, the base station may configure the subframes  806   a ,  806   b  with a subslot configuration in which at least two subslots have a different number of symbols from one another—e.g., the first subslot  810   a  may include four symbols, whereas the second subslot  810   b  may include two symbols. 
       FIG. 9A  is a flowchart of a method  900  of wireless communication. The method may be performed by a base station (e.g., the base station  102 , the base station  402 , the apparatus  1002 / 1002 ′). While the method  900  illustrates a plurality of discrete operations, the present disclosure contemplates aspects in which one or more operations are transposed, omitted, and/or contemporaneously performed. 
     Beginning at  902 , a first base station may configure x subframes with a subslot configuration that includes y subslots. For example, the first base station may schedule at least one subframe, and the first base station may schedule a plurality of subslots during the at least one subframe. In aspects, y may be greater than x. Each subslot of the y subslots may include a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying ACK/NACK information associated with the first portion. The second portion may occur between the first portion and the third portion. In aspects, the second portion and the third portion may include at most one symbol. 
     In one aspect, the first portion of a first subslot of they subslots may include a different number of the one or more symbols than the first portion of a second subslot of the y subslots. For example, the first subslot may include a first portion having two symbols for carrying at least one of data or control information, whereas the second subslot may include a first portion having four symbols for carrying at least one of data or control information. 
     In one aspect, the number of symbols in the first portion may be configurable based at least in part on content that is to be communicated to a UE. For example, the first base station may determine a number of symbols required to communicate content (e.g., URLLC content) based on one or more packets (e.g., packet(s) received from a higher layer of the first base station). 
     In the context of  FIG. 4 , the first base station  402  may configure the first subframe  430  with a subframe configuration that includes the set of subslots  420   a ,  420   b ,  422   a ,  422   b . According to another example, a base station may configure a subframe that includes the self-contained subslot  620 . According to another example, a base station may configure a subframe  702  with the subslot configuration  710 . According to another example, a base station may configure a plurality of subframes  806   a ,  806   b  with a subframe configuration that includes a plurality of subslots  810   a ,  810   b ,  810   c ,  810   d ,  810   e ,  810   f ,  810   g , and at least one subslot  810   d  may cross a subframe boundary  804 . 
     At operation  904 , the first base station may send information indicating the subslot configuration to at least a first neighboring base station. Based on the information indicating the sub slot configuration, the first neighboring base station may configure x subframes with a subframe configuration that includes y subslots so that the subslot configuration used in a cell provided by the first neighboring base station is synchronized with the subslot configuration used in a cell provided by the first base station. The first neighboring base station may be a one-hop neighbor or first-ring neighbor with respect to the first base station, and this subslot configuration synchronization may mitigate interference, introduced by the first neighboring base station, to content (e.g., URLLC content) communicated by the first base station during one or more subslots of they subslots. In the context of  FIG. 4 , the first base station  402  may send information  480  indicating the subslot configuration. 
     At operation  910 , the first base station may communicate content with a UE during at least one of they subslots. For example, the first base station may send content (e.g., URLLC content, data or control information, etc.) in at least one subslot of the y subslots. In the context of  FIG. 4 , the first base station  402  may communicate content  484  (e.g., data or control information) with the first UE  404  during at least one of the URLLC subslots  422   a ,  422   b.    
       FIG. 9B  is a flowchart of a method  920  of wireless communication. The method may be performed by a base station (e.g., the base station  102 , the base station  402 , the apparatus  1002 / 1002 ′). While the method  900  illustrates a plurality of discrete operations, the present disclosure contemplates aspects in which one or more operations are transposed, omitted, and/or contemporaneously performed. 
     Beginning at  922 , a first base station may configure x subframes with a subslot configuration that includes y subslots. For example, the first base station may schedule at least one subframe, and the first base station may schedule a plurality of subslots during the at least one subframe. In aspects, y may be greater than x. Each subslot of the y subslots may include a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying ACK/NACK information associated with the first portion. The second portion may occur between the first portion and the third portion. In aspects, the second portion and the third portion may include at most one symbol. 
     In one aspect, the first portion of a first subslot of they subslots may include a different number of the one or more symbols than the first portion of a second subslot of the y subslots. For example, the first subslot may include a first portion having two symbols for carrying at least one of data or control information, whereas the second subslot may include a first portion having four symbols for carrying at least one of data or control information. 
     In one aspect, the number of symbols in the first portion may be configurable based at least in part on content that is to be communicated to a UE. For example, the first base station may determine a number of symbols required to communicate content (e.g., URLLC content) based on one or more packets (e.g., packet(s) received from a higher layer of the first base station). 
     In the context of  FIG. 4 , the first base station  402  may configure the first subframe  430  with a subframe configuration that includes the set of sub slots  420   a ,  420   b ,  422   a ,  422   b . According to another example, a base station may configure a subframe that includes the self-contained subslot  620 . According to another example, a base station may configure a subframe  702  with the subslot configuration  710 . According to another example, a base station may configure a plurality of subframes  806   a ,  806   b  with a subframe configuration that includes a plurality of subslots  810   a ,  810   b ,  810   c ,  810   d ,  810   e ,  810   f ,  810   g , and at least one subslot  810   d  may cross a subframe boundary  804 . 
     At operation  924 , the first base station may send information indicating the subslot configuration to at least a first neighboring base station. Based on the information indicating the sub slot configuration, the first neighboring base station may configure x subframes with a subframe configuration that includes y subslots so that the subslot configuration used in a cell provided by the first neighboring base station is synchronized with the subslot configuration used in a cell provided by the first base station. The first neighboring base station may be a one-hop neighbor or first-ring neighbor with respect to the first base station, and this subslot configuration synchronization may mitigate interference, introduced by the first neighboring base station, to content (e.g., URLLC content) communicated by the first base station during one or more subslots of they subslots. In the context of  FIG. 4 , the first base station  402  may send information  480  indicating the subslot configuration. 
     At operation  926 , the first base station may cause a second neighboring base station to reduce transmission power during at least one subslot of the y subslots. For example, the first base station may send information intended (e.g., addressed) for a second neighboring base station, and the information may indicate a request or instruction for the second neighboring base station to reduce a transmission power. In an aspect, the second neighboring base station may be at least a two-hop neighbor or second-ring neighbor with respect to the first base station. Because the second neighboring base station is at least a two-hop neighbor, the first neighboring base station may send the information indicating that the second neighboring base station is to reduce transmission power during at least one subslot of the y subslots, for example, based on the information indicating the subslot configuration that is sent by the first base station. Based on the information indicating that the second neighboring base station is to reduce transmission power, the second neighboring base station may reduce transmission power during at least one subslot of they subslots (e.g., during a subframe that occurs contemporaneously with the at least one subslot of the y subslots). 
     In the context of  FIG. 4 , the first base station  402  may cause the second neighboring base station  414  to reduce transmission power during at least one of the URLLC subslots  422   a ,  422   b . The first base station  402  may cause the second neighboring base station  414  to reduce transmission power by sending the information  480  indicating the subslot configuration to the first neighboring base station  410 . Based on the information  480  indicating the subslot configuration received from the first base station  402 , the first neighboring base station  410  may send information  482  indicating that the second neighboring base station  414  is to reduce transmission power at least during at least one of the URLLC subslots  422   a ,  422   b.    
     At operation  928 , the first base station may puncture data or control information associated with eMBB content with content associated with URLLC. For example, the first base station may obtain a URLLC packet (e.g., from a higher layer of the first base station). According to one aspect, when a URLLC packet arrives (e.g., from a higher layer of the first base station), the first base station may puncture data or control information associated with eMBB with URLLC content included in the URLLC packet. For example, the first base station may remove one or more bits associated with eMBB and include one or more bits associated with URLLC content. In an aspect, the URLLC content from a URLLC packet may be carried in two symbols of a first portion of at least one subslot of the y subslots, and the first base station may puncture information associated with eMBB with URLLC content to be carried in the two symbols of the first portion of the at least one subslot of they subslots. 
     In the context of  FIG. 4 , the first base station may puncture data or control information associated with eMBB that would be carried in at least one of the two URLLC subslots  422   a ,  422   b  with URLLC content  484 . In another example, a base station may puncture data or control information associated with eMBB that would be carried in the first portion  622  of the self-contained sub slot  620  with URLLC content included in the URLLC packet  640 . 
     At operation  930 , the first base station may communicate content with a UE during at least one of they subslots. For example, the first base station may send the URLLC content punctured at the at least one sub slot of they sub slots. In the context of  FIG. 4 , the first base station  402  may communicate content  484  (e.g., data or control information) with the first UE  404  during at least one of the URLLC sub slots  422   a ,  422   b.    
       FIG. 10  is a conceptual data flow diagram  1000  illustrating the data flow between different means/components in an exemplary apparatus  1002 . The apparatus  1002  may be a base station. The various components and data flow are intended to be illustrative, and other components and data flow may be present. 
     The apparatus  1002  may include a reception component  1004  configured to receive signals (e.g., from a UE  1050  and/or from a neighboring base station  1060 ,  1070 ). The apparatus  1002  may include a transmission component  1010  configured to transmit signals (e.g., to the UE  1050  and/or to a neighboring base station  1060 ,  1070 ). 
     In aspects, the apparatus  1002  may include a configuration component  1008  that may configure x subframes with a subslot configuration that includes y subslots, and y may greater than x. The configuration component  1008  may configure each subslot of the y subslots to include a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying ACK/NACK information associated with the first portion. The configuration component  1008  may configure each subslot such that the second portion may be between the first portion and the third portion. The configuration component  1008  may configure the second portion and the third portion to span at most one symbol. In an aspect, the configuration component  1008  may configure a number of symbols in the first portion of one or more subslots based at least in part on content to be communicated. In an aspect, the configuration component  1008  may configure a first sub slot of they sub slots to include a different number of the one or more symbols than the first portion of a second subslot of they subslots. In an aspect, the configuration component  1008  may configure they subslots such that at least one subslot of they subslots crosses a subframe boundary. 
     The configuration component  1008  may provide this configuration information to a content component  1006 , the transmission component  1010 , and/or a synchronization component  1012 . 
     The content component  1006  may be configured to determine content that is to be communicated with the UE  1050 , such as URLLC content that is determined from a URLLC packet (e.g., a packet received from a higher layer) and/or eMBB content. The content may include data and/or control information. In one aspect, the content component  1006  may be configured to puncture data or control information associated with eMBB with content associated with URLLC. For example, the content component  1006  may puncture eMBB content with URLLC content in one or more subslots of they subslots. The content component  1006  may provide the content to the transmission component  1010 . The transmission component  1010  may communicate content to the UE  1050  during at least one subslot of they subslots. 
     The synchronization component  1012  may be configured to determine information to be sent to one or more neighboring base station  1060 ,  1070 , for example, to mitigate interference. The first neighboring base station  1060  may be a one-hop or first-ring neighbor with respect to the apparatus  1002 , and the second neighboring base station  1070  may be a two-hop or second-ring neighbor with respect to the apparatus  1002 . 
     In one aspect, the synchronization component  1012  may be configured to determine information indicating the subslot configuration based on information from the synchronization component  1012 . The synchronization component  1012  may cause the transmission component  1010  to send, to the first neighboring base station  1060 , information indicating the subslot configuration. 
     In one aspect, the synchronization component  1012  may be configured to cause the second neighboring base station  1070  to reduce transmission power during at least one subslot of they subslots. For example, the provision of the subslot configuration to the first neighboring base station  1060  may cause the first neighboring base station to send, to the second neighboring base station  1070 , an indication that the second neighboring base station  1070  is to reduce transmission power during at least one subslot of they subslots. 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of  FIGS. 9A-9B . As such, each block in the aforementioned flowcharts of  FIGS. 9A-9B  may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
       FIG. 11  is a diagram  1100  illustrating an example of a hardware implementation for an apparatus  1002 ′ employing a processing system  1114 . The processing system  1114  may be implemented with a bus architecture, represented generally by the bus  1124 . The bus  1124  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  1114  and the overall design constraints. The bus  1124  links together various circuits including one or more processors and/or hardware components, represented by the processor  1104 , the components  1004 ,  1006 ,  1008 ,  1010 ,  1012  and the computer-readable medium/memory  1106 . The bus  1124  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. 
     The processing system  1114  may be coupled to a transceiver  1110 . The transceiver  1110  is coupled to one or more antennas  1120 . The transceiver  1110  provides a means for communicating with various other apparatus over a transmission medium. The transceiver  1110  receives a signal from the one or more antennas  1120 , extracts information from the received signal, and provides the extracted information to the processing system  1114 , specifically the reception component  1004 . In addition, the transceiver  1110  receives information from the processing system  1114 , specifically the transmission component  1010 , and based on the received information, generates a signal to be applied to the one or more antennas  1120 . The processing system  1114  includes a processor  1104  coupled to a computer-readable medium/memory  1106 . The processor  1104  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory  1106 . The software, when executed by the processor  1104 , causes the processing system  1114  to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory  1106  may also be used for storing data that is manipulated by the processor  1104  when executing software. The processing system  1114  further includes at least one of the components  1004 ,  1006 ,  1008 ,  1010 ,  1012 . The components may be software components running in the processor  1104 , resident/stored in the computer readable medium/memory  1106 , one or more hardware components coupled to the processor  1104 , or some combination thereof. The processing system  1114  may be a component of the base station  310  and may include the memory  376  and/or at least one of the TX processor  316 , the RX processor  370 , and the controller/processor  375 . 
     In one configuration, the apparatus  1002 / 1002 ′ for wireless communication includes means for configuring x subframes with a subslot configuration that includes y subslots, and y may be greater than x. In an aspect, each subslot of the y subslots including a first portion having one or more symbols for carrying at least one of data or control information, a second portion having a gap, and a third portion for carrying ACK/NACK information associated with the first portion. In an aspect, the second portion may be between the first portion and the third portion. In an aspect, the second portion and the third portion may be at most one symbol. The apparatus  1002 / 1002 ′ may further include means for sending information indicating the subslot configuration to at least one neighboring base station. The apparatus  1002 / 1002 ′ may further include means for communicating content with a user equipment during at least one of the y subslots. 
     In an aspect, a number of the one or more symbols in the first portion for at least one subslot of the y subslots is based at least in part on the content to be communicated. In an aspect, the first portion of a first sub slot of the y sub slots includes a different number of the one or more symbols than the first portion of a second subslot of the y subslots. In an aspect, at least one subslot of the y subslots crosses a subframe boundary. In an aspect, the means for communicating the content further is configured to puncture data or control information associated with eMBB with the content, wherein the content is associated with URLLC. 
     In an aspect, the apparatus  1002 / 1002 ′ further includes means for causing at least one other base station to reduce transmission power during at least one sub slot of the y subslots, and the at least one other base station may be at least a two-hop neighbor of the base station. 
     The aforementioned means may be one or more of the aforementioned components of the apparatus  1002  and/or the processing system  1114  of the apparatus  1002 ′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system  1114  may include the TX Processor  316 , the RX Processor  370 , and the controller/processor  375 . As such, in one configuration, the aforementioned means may be the TX Processor  316 , the RX Processor  370 , and the controller/processor  375  configured to perform the functions recited by the aforementioned means. 
     It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”