Patent Publication Number: US-2018035455-A1

Title: Techniques for adaptive transmissions during urllc

Description:
CLAIM OF PRIORITY UNDER 35 U.SC. §119 
     The present Application for Patent claims priority to U.S. Provisional Application No. 62/367,988 entitled “TECHNIQUES FOR ADAPTIVE TRANSMISSIONS DURING URLLC” filed Jul. 28, 2016, which is assigned to the assignee hereof and hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     Aspects of this disclosure relate generally to telecommunications, and more particularly to techniques for adapting uplink transmissions for Ultra-Reliable Low-Latency Communications (URLLC) during wireless communications. 
     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 (e.g., bandwidth, transmit power). 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 of an emerging telecommunication standard is Long Term Evolution (LTE). In particular, 5G communications technology for example, 5G communications technology is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations. In an aspect, 5G communications technology includes enhanced mobile broadband addressing human-centric use cases for access to multimedia content, services and data; ultra-reliable-low latency communications (URLLC) with strict requirements, especially in terms of latency and reliability; and massive machine type communications for a very large number of connected devices and typically transmitting a relatively low volume of non-delay-sensitive information. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in 5G communications technology and beyond. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. 
     Methods are needed to provide efficient and improved process for adapting uplink transmissions during wireless communications. In certain instances, as the next generation of wireless communications come into existence, specific latency and reliability requirements are needed to be met in order to ensure adequate levels of wireless communications. Specifically, high reliability delivery and overcoming fading and error in open loop power controls are needed in order to satisfy the specific latency and reliability requirements. Thus, improvements in adapting uplink transmissions during wireless communications are desired. 
     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 accordance with an aspect, a method includes adapting uplink transmission for URLLC during wireless communications. The described aspects include transmitting, by a UE operating in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved frequency division multiplexing (FDM) region of an uplink channel. The described aspects further include receiving an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. The described aspects further include adapting the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. 
     In another aspect, an apparatus for adapting uplink transmission for URLLC during wireless communications may include a transceiver, a memory; and at least one processor coupled to the memory and configured to transmit, by a UE operating in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. The described aspects further receive an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. The described aspects further adapt the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. 
     In another aspect, a computer-readable medium may store computer executable code for adapting uplink transmission for URLLC during wireless communications. The described aspects include code for transmitting, by a UE operating in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. The described aspects further include code for receiving an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. The described aspects further include code for adapting the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. 
     In another aspect, an apparatus for adapting uplink transmission for URLLC during wireless communications is described. The described aspects include means for transmitting, by a UE operating in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. The described aspects further include means for receiving an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. The described aspects further include means for adapting the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. 
     Various aspects and features of the disclosure are described in further detail below with reference to various examples thereof as shown in the accompanying drawings. While the present disclosure is described below with reference to various examples, it should be understood that the present disclosure is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and examples, as well as other fields of use, which are within the scope of the present disclosure as described herein, and with respect to which the present disclosure may be of significant utility. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, nature, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout, where dashed lines may indicate optional components or actions, and wherein: 
         FIG. 1  is a schematic diagram of a communication network including an aspect of an uplink adaptation component during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 2  is flow diagram illustrating an example method of adapting uplink transmissions for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 3  is a diagram of an example transmission scheme for initial transmissions and retransmissions on an uplink channel for adapting uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 4  is a diagram of an example of a transmission scheme for initial transmissions and retransmissions using a fixed-length TTI on an uplink channel to adapt uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 5  is a diagram of an example of a transmission scheme for initial transmissions and downlink grants to adapt uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 6  is a diagram of a transmission scheme for initial transmissions and downlink grants to adapt uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 7  is a diagram of an example of a hybrid transmission scheme for initial transmissions and retransmissions to adapt uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 8  is a data flow diagram illustrating the data flow between different means/components in an exemplary apparatus including a uplink adaptation component to adapt uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
         FIG. 9  is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system including a uplink adaptation component for adapting uplink transmission for URLLC during wireless communications in accordance with various aspects of the present disclosure. 
     
    
    
     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 components are shown in block diagram form in order to avoid obscuring such concepts. In an aspect, the term “component” as used herein may be one of the parts that make up a system, may be hardware or software, and may be divided into other components. 
     The present aspects generally relate to adapting uplink transmissions for URLLC during wireless communications. With regard to URLLC, the user plane latency is defined as successful delivery of application layer packet from layer 2/3 service data unit (SDU) ingress point to layer 2/3 SDU egress point through radio interface. For URLLC, the target for user plane latency is 0.5 ms for uplink communications and 0.5 ms for downlink communications. For eMBB that target for user plane latency is 0.5 ms for both uplink and downlink communications. For mMTC, the occurrence of infrequent small packets may only be no worse than 10 s on uplink communications for 20 byte application packets (with uncompressed IP headers it is 105 PHY) at 164 dB MCL. 
     Reliability is defined as the successful probability of transmitting a number of bytes within 1 ms, which is the time to deliver a small packet from protocol layer 2/3 SDU ingress point to egress point, at a certain channel quality. Specifically, for URLLC, the requirement is 1-10 −5  within 1 ms for the number of bytes (e.g. 20 bytes) with a user plane latency of 1 ms. The user plane latency me be 3-10 ms for direct communications via sidelink and communication ranges of, for example, a few meters. Moreover, the user plane latency may be 2 ms when the packet is relayed via a base station. 
     A need exists for a communication design that fulfills the latency and reliability requirements for URLLC. For example, in order to satisfy a low latency design, the UE needs to be self-scheduling and be configured for contention based SR/PUSCH. Further, for reduced symbol/TTI duration, symbol duration may be configured at 32 us and the TTI may be one or two symbols in length. In order to reduce downlink and uplink turnaround time, one symbol of in-between time may be set. Moreover, pre-emptive vacancy from regular users may be used to avoid interference whenever UL URLLC data is detected. Dynamic termination of eMBB data traffic may occur in shared frequency regions. For demodulation, front loaded control and reserve signaling may be configured. 
     In an example, in order to satisfy a high reliability design, multiple transmissions with adaptive retransmission may be used to ensure high reliable delivery. Further, leveraged feedback may be used for channel adaptation so as to minimize fade and interference margins. Moreover, feedback from eNB provides adjustments for the second transmission as well as interference avoidance. Limited retransmissions may be used, such as two HARQ retransmissions within 1 ms. For reliability split, each transmission of 10 −3  is delivered combined with 10 −6 . In another example, progressive transmissions with early terminations may be used, such as, beginning with high transmit power to overcome fading and error in open loop power control. This example may be used when a user is in a relatively poor channel condition. In a further example, a combination of the two previous examples may be used (e.g., a hybrid HARQ with circuit switched schemes). 
     Accordingly, in some aspects, the present methods and apparatuses may provide an efficient solution, as compared to current solutions, by adapting uplink transmission for URLLC during wireless communications. In other words, in the present aspects, a UE that is operating in an URLLC mode may adjust how uplink transmissions occur in order to fulfill the latency and reliability requirements for URLLC. As such, the present aspects provide one or more mechanisms for transmitting, by a UE operating in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. Moreover, the present aspects also provide one or more mechanisms for receiving an adjustable downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. Additionally, the present aspects also provide one or more mechanisms for adapting the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. 
     Referring to  FIG. 1 , in an aspect, a wireless communication system  100  includes at least one user equipment (UE)  115  in communication coverage of at least network entities  105 . The UE  115  may communicate with network via network entity  105 . In an example, UE  115  may transmit and/or receive wireless communication to and/or from network entity  105  via one or more communication channels  125 , which may include an uplink communication channel (or simply uplink channel) and a downlink communication channel (or simply downlink channel), such as but not limited to an uplink data channel and/or downlink data channel. Such wireless communications may include, but are not limited to, data, audio and/or video information. 
     In accordance with the present disclosure, UE  115  may include a memory  44 , one or more processors  20  and a transceiver  60 . The memory, one or more processors  20  and the transceiver  60  may communicate internally via a bus  11 . In some examples, the memory  44  and the one or more processors  20  may be part of the same hardware component (e.g., may be part of a same board, module, or integrated circuit). Alternatively, the memory  44  and the one or more processors  20  may be separate components that may act in conjunction with one another. In some aspects, the bus  11  may be a communication system that transfers data between multiple components and subcomponents of the UE  115 . In some examples, the one or more processors  20  may include any one or combination of modem processor, baseband processor, digital signal processor and/or transmit processor. Additionally or alternatively, the one or more processors  20  may include an uplink adaptation component  130  for carrying out one or more methods or procedures described herein. The uplink adaptation component  130  may comprise hardware, firmware, and/or software and may be configured to execute code or perform instructions stored in a memory (e.g., a computer-readable storage medium). 
     In some examples, the UE  115  may include the memory  44 , such as for storing data used herein and/or local versions of applications or communication with uplink adaptation component  130  and/or one or more of its subcomponents being executed by the one or more processors  20 . Memory  44  can include any type of computer-readable medium usable by a computer or processor  20 , such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory  44  may be a computer-readable storage medium (e.g., a non-transitory medium) that stores one or more computer-executable codes defining uplink adaptation component  130  and/or one or more of its subcomponents, and/or data associated therewith, when UE  115  is operating processor  20  to execute uplink adaptation component  130  and/or one or more of its subcomponents. In some examples, the UE  115  may further include a transceiver  60  for transmitting and/or receiving one or more data and control signals to/from the network via network entity  105 . The transceiver  60  may comprise hardware, firmware, and/or software and may be configured to execute code or perform instructions stored in a memory (e.g., a computer-readable storage medium). The transceiver  60  may include a first ( 1 st) radio access technology (RAT) radio  160  (e.g. UMTS/WCDMA, LTE-A, WLAN, Bluetooth, WSAN-FA) comprising a modem  165 , and a second (2nd) RAT radio  170  (e.g., 5G) comprising a modem  175 . The 1st RAT radio  160  and 2nd RAT radio  170  may utilize one or more antennas  64 - a  and  64 - b  for transmitting signals to and receiving signals from the network entity  105 . 
     In a blended radio environment such as system  100 , different RATs may make use of different channels at different times. Because different RATs are sharing the spectrum and operating partly independently of others, access to one channel may not imply access to another channel. Accordingly, a device capable of transmitting using multiple channels may need to determine whether each channel is available before transmitting. In order to increase bandwidth and throughput, it may be beneficial in some situations to wait for an additional channel to become available rather than transmitting using currently available channel(s). 
     In some examples, the uplink adaptation component  130  may be configured to adapt uplink transmissions for URLLC during wireless communications. For example, multiple transmissions with adaptive retransmission may be used to ensure high reliable delivery. In another example, progressive transmissions with early terminations may be used. In a further example, a combination of the two examples may be used. 
     In an aspect, for example, UE  115  may perform a random access procedure to connect with the network entity  105 . When UE  115  has connected with network entity  105  and has access to the network, UE  115  may execute uplink adaptation component  130  to transition to the URLLC mode  132 . In an instance, UE  115  may transition to the URLLC mode  132  immediately in response to connecting with the network entity  105 . In another instance, UE  115  may transition to the URLLC mode  132  at any later time after connecting with the network entity  105 . Once in URLLC mode  132 , UE  115  may execute uplink adaptation component  130  to adapt uplink transmissions. For example, uplink adaptation component  130  may adapt uplink transmissions using a number of approaches including, but not limited to: adapting multiple transmissions with adaptive retransmissions, determining a dedicated resource assignment for continuous transmissions, and/or using a combination of these two approaches. 
     In an aspect, uplink adaptation component  130  may adapt uplink transmissions for URLLC during wireless communications. For example, UE  115  may execute transceiver  60  to transmit, while operating in a URLLC mode  132 , a first transmission to a network entity in a first frequency region  134 . In an example, the first frequency region  132  may correspond to a reserved frequency division multiplexing (FDM) region of an uplink channel. UE  115  may execute transceiver  60  to transmit the first transmission using a number of methods. In one example, UE  115  may first reserve the reserved FDM region of the uplink channel. Then, UE  115  may execute transceiver  60  to transmit a service request in the reserved FDM region of the uplink channel to the network entity  105 . In another example, UE  115  may first execute transceiver  60  to receive a physical uplink shared channel (PUSCH) assignment from the network entity  105 . The PUSCH assignment includes, at least a demodulation reference signal (DMRS) sequence. Then, UE  115  may execute transceiver  60  to transmit an orthogonal DMRS to the network entity  105  based on the DMRS sequence. In both examples, the first transmission includes a bundle size of 2 to 4 symbols in length. 
     UE  115  may execute transceiver  60  to receive an downlink grant  136  from the network entity  105  in response to transmitting the first transmission. In an example, the downlink grant  136  indicates at least a second frequency region  138  for uplink transmissions and is different from the first frequency region  134 . For example, the downlink grant  136  includes a fixed timing indication that corresponds to a number of symbols to wait before transmitting the one or both of the retransmission or the subsequent transmission. Moreover, the downlink grant  136  may also include adaptive grant information for transmitting the one or both of the retransmission or the subsequent transmission, the adaptive grant information include at least one of a transmit power, starting time position, time duration, and position in the second frequency region  138 . 
     After receiving the downlink grant  136  from the network entity  105 , UE  115  may execute uplink adaptation component  130  to adapt the first frequency region  134  to the second frequency region  138  for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant  136 . For example, in order to adapt the first frequency region  134  to the second frequency region  138 , UE  115  may execute transceiver  60  to transmit all of the retransmissions and/or subsequent transmissions in the second frequency region  138  instead of the first frequency region  134 . In an example, the second frequency region  138  may correspond to either a reserved frequency region or a non-reserved frequency region compared to the first frequency region  134  which corresponds to a reserved frequency region. Additionally, UE  115  may execute transceiver  60  to transmit the one or both of the retransmission or the subsequent transmission in the second frequency region  138  until a control timer expires. 
     In another aspect, uplink adaptation component  130  may determine a dedicated resource assignment for continuous transmissions. For instance, continuous transmissions may correspond to transmissions that continuously occur until an ACK or some other type of indication to halt transmissions is received. For example, the downlink grant  136  that UE  115  and/or uplink adaptation component  130  receives, may include an indication that the one or both of the retransmission or the subsequent transmission are based on a dedicated resource assignment. UE  115  may execute transceiver  60  to transmit the one or both of the retransmission or the subsequent transmission as a continuous transmission in the second frequency region until an acknowledgement (ACK) signal is received from the network entity indicating a termination of the continuous transmission. In an example, UE  115  may execute transceiver  60  to transmit the one or both of the retransmission or the subsequent transmission irrespective of receiving a retransmission request. Moreover, UE  115  may execute transceiver  60  to increase a transmit power level during the continuous transmission 
     In a further aspect, uplink adaptation component  130  may use a combination of the approaches including a hybrid approach where the first transmission is a contention based transmission or an adaptive based transmission on HARQ, and the subsequent transmissions are based on circuit switching. For example, UE  115  and/or uplink adaptation component  130  may first transmit a first transmission to a network entity in a first frequency region  134 . UE  115  and/or uplink adaptation component  130  may receive an downlink grant  136  from the network entity  105  in response to transmitting the first transmission and adapt the first frequency region to the second frequency region  138 . Then UE  115  and/or uplink adaptation component  130  may transmit the one or both of the retransmission or the subsequent transmission as a continuous transmission in the second frequency region until an ACK signal is received from the network entity indicating a termination of the continuous transmission. 
     In another aspect, uplink adaptation component  130  may use another combination of the approaches including that the first transmission  132  includes a service request and a DMRS sequence, and wherein transmitting the first transmission to the network entity in the first frequency region comprises transmitting the service request and the DMRS sequence on a PUSCH to the network entity in the first frequency region; and transmitting a PUSCH with the DMRS to the network entity in a separate frequency region, the separate frequency region differing from the first frequency region. For example, instead of requiring 1-10 −5  reliability of the service request channel, the system may target lower reliability, e.g. 1-10 −2 . Then network entity detection of DMRS and PUSCH may occur to ensure a higher overall reliability, e.g. 1-10 −5 . 
     A UE  115  may also be referred to by those skilled in the art as 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. A UE  115  may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wearable item such as a watch or glasses, a wireless local loop (WLL) station, or the like. A UE  115  may be able to communicate with macro eNodeBs, small cell eNodeBs, relays, and the like. A UE  115  may also be able to communicate over different access networks, such as cellular or other WWAN access networks, or WLAN access networks. 
     Additionally, as used herein, the one or more wireless nodes, including, but not limited to, network entity  105  of wireless communication system  100 , may include one or more of any type of network component, such as an access point, including a base station or node B, a relay, a peer-to-peer device, an authentication, authorization and accounting (AAA) server, a mobile switching center (MSC), a radio network controller (RNC), etc. In a further aspect, the one or more wireless serving nodes of wireless communication system  100  may include one or more small cell base stations, such as, but not limited to a femtocell, picocell, microcell, or any other base station having a relatively small transmit power or relatively small coverage area as compared to a macro base station. 
     Referring to  FIG. 2 , an example of one or more operations of an aspect of uplink adaptation component  130  ( FIG. 1 ) according to the present apparatus and methods are described with reference to one or more methods and one or more components that may perform the actions of these methods. Although the operations described below are presented in a particular order and/or as being performed by an example component, it should be understood that the ordering of the actions and the components performing the actions may be varied, depending on the implementation. Also, although the uplink adaptation component  130  is illustrated as having a number of subcomponents, it should be understood that one or more of the illustrated subcomponent may be separate from, but in communication with, the uplink adaptation component  130  and/or each other. Moreover, it should be understood that the following actions or components described with respect to the uplink adaptation component  130  and/or its subcomponents may be performed by a specially-programmed processor, a processor executing specially-programmed software or computer-readable media, or by any other combination of a hardware component and/or a software component specially configured for performing the described actions or components. 
     In an aspect, at block  202 , method  200  includes transmitting, by a UE operating in a 
     URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. In an aspect, for example, UE  115 , may execute transceiver  60  and/or uplink adaptation component  130  ( FIG. 1 ) to transmit, while in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. 
     In an aspect, at block  204 , method  200  includes receiving an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. In an aspect, for example, UE  115 , may execute transceiver  60  and/or uplink adaptation component  130  ( FIG. 1 ) to receive an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. 
     In an aspect, at block  206 , method  200  includes adapting the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. In an aspect, for example, UE  115 , may execute uplink adaptation component  130  ( FIG. 1 ) to adapt the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant. 
       FIG. 3  is a diagram illustrating an example transmission scheme  300  for initial transmissions  302  and retransmissions  304  on an uplink channel for adapting uplink transmission for URLLC during wireless communications. For example, initial transmissions  302  and retransmissions  304  may be transmitted from a UE, such as UE  115  ( FIG. 1 ) to a network entity, such as network entity  105  ( FIG. 1 ), using uplink adaptation component  130  ( FIG. 1 ). 
     In an aspect, initial transmissions  302  may include uplink data bursts  306 ,  308 ,  310 ,  312 , and  314 . Further, UE  115  and/or uplink adaptation component  130  may transmit the initial transmissions  302  in a URLLC mode in a first frequency region of the uplink channel. In an example, the initial transmissions  302  may correspond to contention based initial transmissions in a reserved frequency band, such as, a reserved FDM region of the uplink channel. 
     In an aspect, retransmissions  304  may include uplink data bursts  306 ′,  308 ′,  310 ′,  312 ′, and  314 ′. For example, UE  115  and/or uplink adaptation component  130  may determine that retransmissions of the initial transmissions  302  are needed. Further, UE  115  and/or uplink adaptation component  130  may receive an adjustable downlink grant from the network entity  105  in response to transmitting one or more uplink data bursts of the initial transmissions  302 . Based on a determination that retransmissions of the initial transmissions  302  are needed and the reception of the adjustable downlink grant from the network entity  105 , UE  115  and/or uplink adaptation component  130  may transmit retransmissions  304  of uplink data bursts in separate frequency regions. 
     Due to full adaptation based on the received adjustable downlink grant, retransmissions may be transmitted with an adapted load distribution, bandwidth/transmission time interval (TTI) allocation, geometry, payload size, etc. In an example, uplink data burst  306  may be retransmitted as uplink data burst  306 ′ with an extended TTI allocation. In another example, uplink data burst  308 ′ may be transmitted on a different frequency region of the uplink channel. In another example, uplink data burst  310 ′ may be transmitted on an extended frequency region of the uplink channel. In another example, uplink data burst  312 ′ may be transmitted in a similar manner as uplink data burst  312 , In another example, uplink data burst  314 ′ may be transmitted with an extended TTI allocation and on an extended frequency region of the uplink channel. 
       FIG. 4  is a diagram illustrating an example of a transmission scheme  400  for initial transmissions  402  and retransmissions  406  using a fixed-length TTI on an uplink channel for adapting uplink transmission for URLLC during wireless communications. For example, initial transmissions  402  and retransmissions  406  may be transmitted from a UE, such as UE  115  ( FIG. 1 ) to a network entity, such as network entity  105  ( FIG. 1 ), using uplink adaptation component  130  ( FIG. 1 ). 
     In an aspect, initial transmissions  402  may include uplink data bursts  408 ,  410 , and  412 . 
     Further, UE  115  and/or uplink adaptation component  130  may transmit the initial transmissions  402  in a URLLC mode in a first frequency region of the uplink channel. In an example, the initial transmissions  402  may correspond to contention based initial transmissions in a reserved frequency band, such as, a reserved FDM region of the uplink channel. Moreover, these initial transmissions  402  may be transmitted using a fixed transmission scheme that employs a fixed-length TTI. For example, the duration of the TTI for each of uplink data bursts  408 ,  410 , and  412  are the same. 
     In an aspect, downlink grants  404 , including adaptive grants  414  and  416 , may be transmitted on a downlink channel from network entity  105  to UE  115 . For example, the downlink grants  404  may include information corresponding to at least one of the transmit power or an MCS adjustment. Due to the fixed transmission scheme employing a fixed-length TTI, the downlink grants  404  may not be configured to include information corresponding to the TTI duration. 
     Based on the reception of adaptive grant  414 , UE  115  may be configured to transmit uplink data burst  408 ′ with the same TTI duration as uplink data burst  408 , and during the same time slot as uplink data burst  412 . Similarly, UE  115  may receive adaptive grant  416 , and transmit uplink data burst  410 ′ with the same TTI duration as uplink data burst  410 ′. 
       FIG. 5  is a diagram illustrating an example of a transmission scheme  500  for initial transmissions  502  and downlink grants  504  for adapting uplink transmission for URLLC during wireless communications. For example, initial transmissions  502  may be transmitted from a UE, such as UE  115  ( FIG. 1 ) to a network entity, such as network entity  105  ( FIG. 1 ), using uplink adaptation component  130  ( FIG. 1 ). Further, downlink grants  504  may be transmitted from network entity  105  to UE  115  on a downlink channel. 
     In an aspect, multiple transmissions may be made within a specified time period (e.g., 1 ms). For example, initial transmissions  502  may be transmitted on the uplink channel with 1 symbol TTI. In this example, UE  115  may be configured to transmit a plurality of uplink data bursts  506 ,  508 ,  510 , and  512  within a specified time period. This direct adaptive transmissions with 1 symbol TTI requires a substantial amount of overhead. 
       FIG. 6  is a diagram illustrating an example of a transmission scheme  600  for initial transmissions  602  and downlink grants  604  for adapting uplink transmission for URLLC during wireless communications. For example, initial transmissions  602  may be transmitted from a UE, such as UE  115  ( FIG. 1 ) to a network entity, such as network entity  105  ( FIG. 1 ), using uplink adaptation component  130  ( FIG. 1 ). Further, downlink grants  604  may be transmitted from network entity  105  to UE  115  on a downlink channel. 
     In an aspect, uplink data bursts may be bundled together for an extended TTI as compared to the uplink data bursts of  FIG. 5 . For example, if a downlink grant  604 , such as adaptive grants  612 ,  614 , and  616 , may be received within 1 symbol using power boosting and/or wider frequency assignment, then uplink data bursts  606 ,  608 , and  610  may be bundled. In this example, uplink data bursts  606 ,  608 , and  610  may be transmitted with 2 symbols TTI. 
       FIG. 7  is a diagram illustrating an example of a hybrid transmission scheme  700  for initial transmissions  702  and retransmissions  706  for adapting uplink transmission for URLLC during wireless communications. For example, initial transmissions  702  and retransmissions  706  may be transmitted from a UE, such as UE  115  ( FIG. 1 ) to a network entity, such as network entity  105  ( FIG. 1 ), using uplink adaptation component  130  ( FIG. 1 ). Further, downlink grants  704  may be transmitted from network entity  105  to UE  115  on a downlink channel. 
     In an aspect, the hybrid transmission scheme  700  may employ initial transmissions  702  may correspond to contention based initial transmissions in a reserved frequency band, such as, a reserved FDM region of the uplink channel and/or an adaptive based transmission on hybrid automatic repeat request (HARQ). For example, initial transmissions  702  may include uplink data bursts  708 ,  710 , and  712 . Further, UE  115  and/or uplink adaptation component  130  may transmit the initial transmissions  702  in a URLLC mode in a first frequency region of the uplink channel. 
     In an aspect, the hybrid transmission scheme  700  may employ downlink grants  704 , including adaptive grants  714  and  716 , which include an indication that the at least one or both of the retransmission or the subsequent transmission are based on a dedicated resource assignment. For example, adaptive grants  714  and  716  may indicate at least a second frequency region for uplink transmissions different from the first frequency region in which the initial transmissions  702  were transmitted on. 
     In an aspect, the hybrid transmission scheme  700  may include retransmissions  706 , such as a continuous transmission  708 ′ in the second frequency region until an ACK signal is received from the network entity  105  indicating a termination of the continuous transmission. Further, UE  115  may transmit the continuous transmission  708 ′ irrespective of receiving a retransmission request. Moreover, UE  115  may increase a transmit power level during the continuous transmission  708 ′. 
       FIG. 8  is a conceptual data flow diagram  800  illustrating the data flow between different means/components in an exemplary apparatus  802  that includes uplink adaptation component  808 , which may be the same as or similar to uplink adaptation component  130  for adapting uplink transmission for URLLC during wireless communications. The apparatus  802  may be a UE, which may include UE  115  of  FIG. 1 . The apparatus  802  includes a transmission component  806  that transmits, by UE  115  operating in a URLLC mode, a first transmission to a network entity  850  in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel. The apparatus  802  includes a reception component  804  that receives an adjustable downlink grant from the network entity in response to transmitting the first transmission, the adjustable downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. The apparatus  802  includes an uplink adaptation component  808  that adapts the first frequency region to the second frequency region for transmitting at least one or both of a retransmission or a subsequent transmission based on the adjustable downlink grant. 
     The apparatus  802  may include additional components that perform each of the blocks of the algorithm in the aforementioned flowchart of  FIG. 2 . As such, each block in the aforementioned flowchart of  FIG. 2  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. 9  is a diagram  900  illustrating an example of a hardware implementation for an apparatus  802 ′ employing a processing system  914  that includes uplink adaptation component  808  ( FIG. 9 ), which may be the same as or similar to uplink adaptation component  130  for adapting uplink transmission for URLLC during wireless communications. The processing system  914  may be implemented with a bus architecture, represented generally by the bus  924 . The bus  924  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  914  and the overall design constraints. The bus  924  links together various circuits including one or more processors and/or hardware components, represented by the processor  904 , the components  804 ,  806 ,  808 , and the computer-readable medium/memory  906 . The bus  924  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  914  may be coupled to a transceiver  910 . The transceiver  910  is coupled to one or more antennas  920 . The transceiver  910  provides a means for communicating with various other apparatus over a transmission medium. The transceiver  910  receives a signal from the one or more antennas  920 , extracts information from the received signal, and provides the extracted information to the processing system  914 , specifically the reception component  804 . In addition, the transceiver  910  receives information from the processing system  914 , specifically the transmission component  806 , and based on the received information, generates a signal to be applied to the one or more antennas  920 . The processing system  914  includes a processor  904  coupled to a computer-readable medium/memory  906 . The processor  904  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory  906 . The software, when executed by the processor  904 , causes the processing system  914  to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory  906  may also be used for storing data that is manipulated by the processor  904  when executing software. The processing system  914  further includes at least one of the components  804 ,  806 , and  808 . The components may be software components running in the processor  904 , resident/stored in the computer readable medium/memory  906 , one or more hardware components coupled to the processor  904 , or some combination thereof 
     In one configuration, the apparatus  802 / 802 ′ for wireless communication includes means for transmitting, by a UE operating in a URLLC mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved FDM region of an uplink channel, means for receiving an adjustable downlink grant from the network entity in response to transmitting the first transmission, the adjustable downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region, and means for adapting the first frequency region to the second frequency region for transmitting at least one or both of a retransmission or a subsequent transmission based on the adjustable downlink grant. The aforementioned means may be one or more of the aforementioned components of the apparatus  802  and/or the processing system  914  of the apparatus  802 ′ configured to perform the functions recited by the aforementioned means. 
     In some aspects, an apparatus or any component of an apparatus may be configured to (or operable to or adapted to) provide functionality as taught herein. This may be achieved, for example: by manufacturing (e.g., fabricating) the apparatus or component so that it will provide the functionality; by programming the apparatus or component so that it will provide the functionality; or through the use of some other suitable implementation technique. As one example, an integrated circuit may be fabricated to provide the requisite functionality. As another example, an integrated circuit may be fabricated to support the requisite functionality and then configured (e.g., via programming) to provide the requisite functionality. As yet another example, a processor circuit may execute code to provide the requisite functionality. 
     It should be understood that any reference to an element herein using a designation such as “first,” “second,” and so forth does not generally limit the quantity or order of those elements. Rather, these designations may be used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in some manner. Also, unless stated otherwise a set of elements may comprise one or more elements. In addition, terminology of the form “at least one of A, B, or C” or “one or more of A, B, or C” or “at least one of the group consisting of A, B, and C” used in the description or the claims means “A or B or C or any combination of these elements.”For example, this terminology may include A, or B, or C, or A and B, or A and C, or A and B and C, or 2A, or 2B, or 2C, and so on. 
     Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof 
     Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. 
     The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. 
     Accordingly, an aspect of the disclosure can include a computer readable medium embodying a method for dynamic bandwidth management for transmissions in unlicensed spectrum. Accordingly, the disclosure is not limited to the illustrated examples. 
     While the foregoing disclosure shows illustrative aspects, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Furthermore, although certain aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.