Transmission with restriction in unlicensed spectrum

Abstract

To provide systems, devices, and methods for operating in an unlicensed band.SOLUTION: There are disclosed systems, devices, and methods for operating in an unlicensed band. In one example, a device may receive configuration information that includes a maximum channel occupancy time (MCOT) and a plurality of parameters including a plurality of transmission opportunity windows (TOWs). Based on the configuration information, the device may split a transmission into a plurality of bursts that may be grouped into sets of bursts based on how many bursts fit within a TOW. The number of bursts in a set of bursts may be less than or equal to the MCOT. The device may perform a clear channel assessment (CCA) to determine if the channel is busy and to determine a start time within the TOW for the bursts. The device may then transmit the set of bursts for the TOW, and each burst may have a burst indicator (BI).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 524,229, filed June 23, 2017, the contents of which are incorporated herein by reference. [Background technology]

[0002] As more devices become wirelessly capable and smartphones become increasingly popular, cellular communications are experiencing a significant increase in demand. Cellular communications can be used to serve a variety of markets, including home telephony, the Internet of Things, and low-latency market segments, to name a few. While regulatory bodies can issue licenses for the use of cellular communications spectrum, opportunities may exist where cellular communications can occur in unlicensed spectrum. Summary of the Invention [Problem to be solved by the invention]

[0003] Operation in unlicensed spectrum may require addressing spectrum sharing with multiple devices by using a channel sensing scheme without a central controller. [Means for solving the problem]

[0004] Systems, devices, and methods for operating in unlicensed bands are disclosed herein. In one example, a device may receive configuration information including multiple parameters, including a maximum channel occupancy time (MCOT) and multiple transmission opportunity windows (TOWs). Based on the configuration information, the device may divide a transmission into multiple bursts, which may be grouped into sets of bursts based on how many bursts fit within the TOW. The number of bursts in the set of bursts may be less than or equal to the MCOT. The device may perform a clear channel assessment (CCA) to determine whether the channel is busy and to determine a start time within the TOW for a burst. The device may then transmit the set of bursts for that TOW, where each burst may have a burst indicator (BI). A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements. [Effects of the Invention]

[0005] Systems, devices and methods for operating in unlicensed bands are provided. [Brief explanation of the drawings]

[0006] [Figure 1A] 1 is a system diagram of an example wireless transmit / receive unit (WTRU) used in a communication system. [Figure 1B] FIG. 1 is a diagram of an exemplary communication system according to one or more embodiments. [Figure 1C] 1B is a system diagram of an example radio access network and core network used in a communication system such as that shown in FIG. [Figure 2A]FIG. 1 is a diagram of an example process for transmitting based on available resources according to one or more embodiments. [Figure 2B] FIG. 1 is a diagram of an exemplary transmission based on available resources according to one or more embodiments. [Figure 3A] FIG. 1 is a diagram of an example process for time-constrained transmission on a set of allocated resources according to one or more embodiments. [Figure 3B] 1 is a diagram of an example time-constrained transmission for a set of allocated resources according to one or more embodiments. [Figure 4A] FIG. 1 is a diagram of an example process for splitting a transmission into bursts according to one or more embodiments. [Figure 4B] FIG. 1 is a diagram of an exemplary transmission using split bursts. [Figure 5] FIG. 10 is a diagram of an example transmission using a burst indicator. [Figure 6] FIG. 10 is a diagram of an example transmission process using a burst indicator. DETAILED DESCRIPTION OF THE INVENTION

[0007] Cellular communications can focus on several communication device market segments, such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and machine-type communications (MTC). The evolution of Internet of Things (IoT) applications can address connectivity solutions for sensors, actuators, meters, appliances, vehicles, and other similar devices. IoT networks can have various design objectives, ranging from localized area coverage to wide-area coverage. These networks can be optimized to provide extended device coverage, reduced device complexity, and long device battery life. As discussed herein, the terms apparatus and device are interchangeable.

[0008] 1A is a device diagram of an example wireless transmit / receive unit (WTRU) 102. The WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the elements described above herein while remaining consistent with any disclosed embodiment.

[0009] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), field programmable gate array (FPGA) circuitry, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1A depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0010] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In another embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and receive both RF and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0011] 1A as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may use MIMO techniques. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0012] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate over multiple RATs, such as, for example, UTRA and IEEE 802.11.

[0013] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Additionally, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0014] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0015] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0016] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos or videos), a Universal Serial Bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, and the like.

[0017] A WTRU may operate in a cellular communication network that may be deployed in a licensed spectrum. However, as the demand for cellular applications increases, the traffic load in the licensed spectrum may increase, in which case the operator may need to purchase more licensed spectrum to meet the demands of the increased traffic load. Because licensed spectrum is expensive, an alternative approach may be to offload cellular traffic to unlicensed bands. Unlicensed spectrum bands may also be used for non-cellular applications such as WiFi, Bluetooth, and applications supported by other wireless protocols.

[0018] 1B is a diagram of an example communication system 100 (e.g., a cellular communication network) in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, and broadcast, to multiple wireless users. The communication system 100 enables the multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may use one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), and the like.

[0019] The term channel may be used herein to refer to a data channel, a control channel, and / or another channel or signal that may be transmitted and / or received. A data channel may be, for example, a Physical Downlink Shared Channel (PDSCH), a Narrowband (NB)-PDSCH, a New Radio (NR)-PDSCH, a Physical Uplink Data Channel (PUSCH), a NB-PUSCH, or a NR-PUSCH, among others. A control channel may be, for example, a Physical Downlink Control Channel (PDCCH), an Enhanced (E)-PDCCH, a NB-PDCCH, a NR-PDCCH, a Physical Uplink Control Channel (PUCCH), a NB-PUCCH, or a NR-PUCCH, among others. A channel may be, for example, a random access channel, such as a Physical Random Access Channel (PRACH), or a broadcast channel, such as a Physical Broadcast Channel (PBCH). The term channel may be used herein to refer to a frequency or operating channel that may be used for transmission and / or reception. A channel may be free or busy, but should be free before transmitting on the channel. The common channel may be a control channel such as a DL control channel, a paging channel, a broadcast channel, a shared channel, among others, and the shared channel may carry common information such as a random access response (RAR), a paging channel or message, and / or system information.

[0020] 1B, communications system 100 may include several interacting elements, such as wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, pagers, cellular telephones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, consumer electronic devices, and the like.

[0021] The communications system 100 may also include a base station 114a and a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communications networks, such as the core network 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a Base Transceiver Station (BTS), a Node B, an eNodeB (eNB), a Home Node B, a Home eNodeB, a site controller, an Access Point (AP), a wireless router, a gNB, a TRP, a STA, a cell, and the like, and may be used interchangeably herein. While the base stations 114a, 114b are each shown as a single element, it will be understood that the base stations 114a, 114b may include / represent any number of interconnected base stations and / or network elements. Similarly, as discussed herein, references to an eNB may be used to represent one or more of a gNB, TRP, STA, cell, base station, and / or the like. The individual elements that make up a node on the network may be considered to be devices such as a base station or a WTRU.

[0022] The base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals within a particular geographic area, which may be referred to as a cell (not shown). A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In another embodiment, the base station 114a may use multiple-input multiple-output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell.

[0023] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0024] More specifically, as noted above, the communications system 100 may be a multiple access system and may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using Wideband CDMA (WCDMA). WCDMA may include communications protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0025] In another embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A).

[0026] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), GSM Evolution Enhanced Data Rates (EDGE), GSM EDGE (GERAN), and the like.

[0027] 1B may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as a workplace, home, vehicle, campus, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1B, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114 b may not need to access the Internet 110 via the core network 106 .

[0028] The RAN 104 may communicate with the core network 106, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1B , it will be understood that the RAN 104 and / or core network 106 may communicate directly or indirectly with other RANs that use the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104 that may utilize E-UTRA radio technology, the core network 106 may also communicate with another RAN (not shown) that uses GSM radio technology.

[0029] The core network 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Protocol (IP) in the TCP / IP Internet protocol suite. The network 112 may include wired or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another core network connected to one or more RANs, which may use the same RAT as the RAN 104 or a different RAT.

[0030] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links.) For example, the WTRU 102c shown in FIG. 1B may be configured to communicate with a base station 114a that can use cellular-based wireless technology and with a base station 114b that can use IEEE 802 wireless technology.

[0031] 1C is a system diagram of the RAN 104 and the core network 106 according to an embodiment. As mentioned above, the RAN 104 may use E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the core network 106.

[0032] The RAN 104 may include eNodeBs 140a, 140b, and 140c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 140a, 140b, and 140c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNodeBs 140a, 140b, and 140c may implement MIMO technology. Thus, for example, the eNodeB 140a may use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0033] Each of the eNodeBs 140a, 140b, 140c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users on the uplink and / or downlink, and the like. As shown in FIG. 1C, the eNodeBs 140a, 140b, 140c may communicate with one another via an X2 interface.

[0034] 1C may include a mobility management entity gateway (MME) 142, a serving gateway 144, and a packet data network (PDN) gateway 146. Although each of the foregoing elements is shown as part of the core network 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the core network operator.

[0035] The MME 142 may be connected to each of the eNodeBs 140a, 140b, 140c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 142 may handle authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 142 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that use other radio technologies, such as GSM or WCDMA.

[0036] The serving gateway 144 may be connected to each of the eNodeBs 140a, 140b, 140c in the RAN 104 via an S1 interface. The serving gateway 144 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The serving gateway 144 may also perform other functions such as fixing the user plane during handover between eNodeBs, triggering paging when downlink data is available to the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0037] The serving gateway 144 may also be connected to a PDN gateway 146, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0038] The core network 106 may facilitate communication with other networks. For example, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communication between the WTRUs 102a, 102b, 102c and traditional land-line communication devices. For example, the core network 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the core network 106 and the PSTN 108. Additionally, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to networks 112, which may include other wired or wireless networks owned and / or operated by other service providers.

[0039] The other network 112 may further be connected to an IEEE 802.11-based wireless local area network (WLAN) 160. The WLAN 160 may include an access router 165. The access router may include a gateway function. The access router 165 may communicate with multiple access points (APs) 170a, 170b. Communication between the access router 165 and the APs 170a, 170b may be via wired Ethernet (IEEE 802.3 standard) or any type of wireless communication protocol. The AP 170a wirelessly communicates with the WTRU 102d via an air interface.

[0040] In either of the systems shown in Figures 1B and 1C, an operator may choose to use both licensed and unlicensed spectrum for reasons discussed herein. There may be constraints imposed on using unlicensed spectrum bands, such as using a channel sensing scheme to share spectrum with multiple WTRUs without a central controller. The operation or use of a cell, transmission / reception point (TRP), or carrier in an unlicensed band may be standalone or may be assisted by the operation or use of a cell, TRP, or carrier in a licensed band. Such an assisted deployment scenario may be referred to herein as Licensed Assisted Access (LAA). In the case of LAA, the licensed cell, TRP, or carrier may be a primary or anchor cell, TRP, or carrier.

[0041] When considering cellular system operation in an unlicensed spectrum, for example, coexistence with cellular systems having other unlicensed technologies, such as WiFi, as well as other cellular operators may need to be addressed in order to minimize interference and provide fairness among users of the spectrum. Mechanisms such as Listen-Before-Talk (LBT) or Clear Channel Assessment (CCA) may be used. With LBT and CCA, system nodes such as access points (APs), eNodeBs (eNBs), gNodeBs (gNBs), TRPs, user equipment (UEs), WTRUs, and the like, may receive a channel (e.g., a frequency band with a certain center frequency and bandwidth) to determine whether there is another WTRU using the channel before transmitting on that channel or portion of a channel. Receiving and / or determining the use of another WTRU may include or be based on measurements, which may include energy detection.

[0042] LBT, CCA, and LBT / CCA may be used interchangeably herein. If a measurement (e.g., of energy) is above a threshold, the channel may be determined to be busy, occupied, or in use. If a measurement (e.g., of energy) is below a threshold, the channel may be determined to be idle, free, vacant, or unused.

[0043] Clear, free, idle, available, not occupied, and not busy can be used interchangeably. Not clear, not free, not idle, not available, occupied, and busy can be used interchangeably. Channel, frequency channel, and operating channel can be used interchangeably. CCA failure can mean that the channel was found to be busy. CCA pass can mean that the channel was found to be clear.

[0044] In an example, a transmitter on a channel, such as a WTRU with a potential UL transmission and / or an eNB with a potential DL transmission, may evaluate and / or monitor (i.e., receive) the channel to measure and / or determine the presence of a signal or interference on the channel before transmitting to determine whether the channel may be in use (e.g., busy and / or occupied) by another system, WTRU, or signal. The transmitter may, for example, compare the received signal and / or interference from the channel to some criteria, such as one or more threshold levels, and based on the comparison, determine whether the channel is free as part of an LBT / CCA step. If the transmitter determines that the channel is free, the transmitter may transmit on that channel. If the transmitter determines that the channel is not free, the transmitter may not transmit on that channel and / or may postpone and / or discard the potential transmission. As discussed herein, a transmitter may refer to any transmitting device, such as a WTRU, an eNB, etc. Similarly, a receiver may refer to any receiving device, such as a WTRU, an eNB, etc. In one example, the transmitter may be a WTRU (e.g., for UL transmission) and / or an eNB (e.g., for DL ​​transmission). In another example, the receiver may be a WTRU (e.g., for DL ​​reception) and / or an eNB (e.g., for UL reception).

[0045] A frame-based device (FBE) may refer to a device whose transmission / reception timing is fixed and / or may be structured. A load-based device (LBE) may not perform LBT / CCA with a fixed frame structure (e.g., at a fixed or defined time). An LBE may perform LBT / CCA whenever it has data to transmit. As discussed herein, an FBE may be any node or device, such as a WTRU, UE, eNB, gNB, TRP, STA, or AP, that can transmit and / or receive on licensed or unlicensed channels.

[0046] Regarding channel evaluation, before transmitting or transmitting a burst of transmissions on an operating channel, a device may perform an LBT / CCA check to detect channel energy, as discussed herein. The LBT / CCA time period for channel evaluation may be a fixed or minimum amount of time. Channel Occupancy Time (COT) may be the total time a transmitter may transmit on a given channel without re-evaluating the availability of that channel. A maximum COT (MCOT) value may be configured by the system and / or as dictated by relevant wireless standards or regulations. The MCOT for any transmitter may be set by the device manufacturer but may be lower than the system's MCOT value. Exemplary values ​​for MCOT may be 4 ms or 10 ms.

[0047] An idle period can be a time (e.g., a continuous period of time) during which a device cannot transmit on a channel. An idle period can have a minimum requirement for COT, such as, for example, 5% of the COT that can be used by the device for the current fixed frame period.

[0048] If a transmitter determines, during or as a result of LBT / CCA, that one or more operating channels are free, it can transmit on the free channel or channels (e.g., immediately). If a transmitter determines, during or as a result of LBT / CCA, that an operating channel is occupied, it cannot transmit on that channel until it performs a subsequent LBT / CC that determines that the channel is free. If a transmitter determines, during or as a result of LBT / CCA, that an operating channel is occupied, it cannot transmit on that channel during the next fixed frame period. LBT / CCA can be performed subsequently after determining that a channel is not free and can include a waiting or backoff period before checking for a free channel.

[0049] In some scenarios, such as for 3GPP LAA, the WTRU may perform CCA to determine whether the channel is free. If the WTRU determines that the channel is not free, the WTRU may then add a backoff or waiting time, such as an additional contention window amount of time. After the WTRU determines that the channel is free, the WTRU may check again before actually transmitting (i.e., the actual transmission may not begin immediately after the channel is determined to be free). For example, if the WTRU is not within a check window (e.g., 25 μs) before actual transmission, the WTRU may perform CCA for at least the check window amount of time before actual transmission, and the WTRU may transmit only if the channel is determined to be free for at least a portion of the check window amount of time.

[0050] Any reference to CCA may be full CCA or short CCA. Full CCA may include adding one or more backoff times when the channel is determined to be busy. Short CCA may perform a quick check (e.g., an energy detection check) in a check window before starting a transmission or intended / planned transmission. For example, when a WTRU performs CCA for the first subframe (SF) or symbol, the WTRU may perform full CCA to determine if the channel is free. The WTRU may perform short CCA before the actual transmission to recheck that the channel is still free, for example, if there is a gap between the end of full CCA and the start of the actual transmission.

[0051] In some scenarios, such as LTE LAA UL, the WTRU may perform CCA for transmissions that start on the starting boundary of a time period or on the boundary of a time unit that may be within a time period.

[0052] A subframe is used herein as a non-limiting example of a time period, a time unit, and / or a time resource. Other examples of a time period include a set of subframes, a frame, a set of frames, a slot, a minislot, a set of slots or minislots, a TTI, a short TTI, a multi-symbol TTI, a symbol, a set of TTIs, a set of symbols, a sync burst, a sync block, a set of sync bursts or sync blocks, and the like. A symbol is used herein as a non-limiting example of a time unit that may be included in a time period. A time period may include one or more time units. Other examples of a time unit include a slot, a minislot, a TTI, a short TTI, a multi-symbol TTI, a set of symbols, a sync burst, a sync block, and the like. In some examples, a time unit and a time period may be used interchangeably. In some examples, a time unit may be a subframe. In some examples, a time resource may be or may be used to represent one or more time periods and / or one or more time units.

[0053] In an example, a WTRU may perform full CCA for transmissions starting on a subframe boundary or for transmissions starting on an indicated symbol boundary within a subframe. The WTRU may receive a grant for one subframe (e.g., a full or partial subframe) or for a set of consecutive subframes. The WTRU may perform short CCA before transmitting on the granted subframes. If the WTRU determines that CCA fails (e.g., the channel is busy or not idle) for the set of granted subframes, the WTRU may perform full / short CCA for the next or subsequent granted subframe. If the WTRU determines that the channel is free for a subframe in the set of granted subframes, the WTRU may transmit on that subframe and on the remaining subframes in the granted set. For example, if the transmission is continuous, transmissions may be performed on subsequent subframes without performing CCA. If there is an interruption in transmission, the WTRU may perform another short CCA for transmissions on subframes in the set after the interruption.

[0054] In embodiments, channel sharing may be implemented using time durations (e.g., windows or gaps) during which a device (e.g., a WTRU) cannot use the channel. The time durations during which a channel can and / or cannot be used may be pre-configured. A coexistence gap may be used to represent the time duration during which a channel cannot be used, for example, based on a configuration.

[0055] A device cannot use the channel for transmission and / or reception during a coexistence gap. A device may consider a channel to be busy or unavailable during a coexistence gap. A device may consider a channel to be free, usable, or available at times other than during a coexistence gap, for example, when one or more coexistence gaps are configured (e.g., determined based on a configuration) and / or when CCA is not used to determine channel availability.

[0056] In an embodiment, the WTRU may use Coverage Enhancement (CE) techniques. For example, the WTRU may use repetition to improve transmission or reception performance or coverage. The transmission repetitions may be combined (e.g., soft combining) at the receiver to improve transmission or reception performance or coverage. In a CE example, the transmitter may repeat a transmission X times (i.e., X time periods or units), and the receiver may combine up to X transmissions to successfully receive the transmission, where successful reception may be determined based on a CRC check. There may be one or more CE levels supported in a cell and / or by an eNB. The WTRU may determine and / or operate using the CE level. The CE level may use, correspond to, and / or be configured with several repetitions. The number of repetitions that may be used for a CE level may be different for different WTRUs and / or for different purposes (e.g., different signals or channels). The WTRU may transmit and / or receive according to a CE level and / or according to a number of repetitions that may be configured (e.g., configured for a CE level). A higher CE level (e.g., a CE level with more CEs) may use more repetitions.

[0057] In some scenarios, a device (e.g., a WTRU) may operate or be limited to operate within a bandwidth (BW) that may be less than the operating BW of a cell or node (e.g., system bandwidth, carrier bandwidth in the system, etc.), where the cell or node may be at least one of: a) the cell or node to which the WTRU is camped, b) the cell or node to which the WTRU is connected or in communication, and / or c) the cell or node that is the WTRU's serving cell or node. Such a WTRU may be considered a bandwidth (BW)-limited or narrowband (NB) WTRU. A bandwidth-limited or NB WTRU will have limited capability to simultaneously transmit and / or receive signals in the limited bandwidth or narrowband. BW-limited and NB may be used interchangeably herein.

[0058] The BW limit of the WTRU may be the BW limit of the RF, which may be a value such as 200 kHz or 1 Physical Resource Block (PRB), 1.4 MHz or 6 PRB, or 3 MHz or 15 PRB.

[0059] A BW-limited or NB WTRU, which may be limited to operate at an NB, such as 1 or 6 PRB, may be limited per time duration, time period, or time unit. For example, a BW-limited WTRU may transmit and / or receive at one NB at or during a first time unit or time period and at another NB at or during a second time unit or time period. For example, there may be, or need to be, a gap in time between the first and second time units or time periods so that the WTRU can tune to the second NB.

[0060] A WTRU of a NB may transmit (or receive) a portion of its transmission (or a transmission from another node) in each of multiple time units or time periods, for example, to compensate for its BW limitations. For example, a WTRU that may be limited to one PRB in a time unit or time period may transmit (or receive) a 6 PRB transmission, with one PRB in each of six time units or time periods.

[0061] A WTRU that is not BW-limited may transmit or receive (e.g., a transmission that may be or include a signal, a channel, a transport block, etc.) using or over a first time unit (or time period), such as a subframe. A WTRU that is BW-limited may transmit or receive using a second time unit (or time period), which may be a multiple of the first time unit.

[0062] As previously discussed, the amount of time a device can occupy (e.g., transmit, etc.) an unlicensed channel may be limited by a configured value, such as, for example, MCOT, which may be based on at least one of fairness, a standard, or a regulation.

[0063] For some applications, such as narrowband, bandwidth-limited, and / or CE applications, a transmission (e.g., of a control channel, data channel, or transport block) requires or can use a set of time units and / or time periods to complete the transmission. The set of time units and / or time periods can exceed a limit such as an MCOT. The transmitter may need to release or release the channel before the transmission is complete. For example, a CE transmission may use 100 subframes, and the MCOT may be 10 ms (e.g., 10 subframes).

[0064] A need may exist for a system, method, and device that allows a transmitter to release a channel at least once during a transmission and subsequently complete the transmission, and allows a receiver to receive (e.g., successfully receive) the complete transmission. To address this need, one or more of the following may be used: a transmission may be based on available resources when the channel is free; a transmission may be on N of M allocated resources for both a single assignment and a set of assignments; a transmission may be split into multiple bursts; and / or an indicator may be included (used) in each burst to allow a receiver to assemble or combine bursts. For example, a WTRU may send a transmission of at least one channel (e.g., a data or control channel) and / or transport block using a set of resources (e.g., in time and / or frequency) when a channel (frequency channel) is determined to be usable or available (e.g., when CCA is determined to pass), if the transmission fits in a remaining subset of the set of resources.

[0065] As discussed herein, a transmission may be or include at least one channel, signal, transport block, code block group, or code block, where a transmission block may correspond to one or more code blocks or code block groups. A transmission may be or include one or more repetitions (e.g., sets of repetitions) of a channel, signal, or transport block that may be combined (e.g., soft-combined) to receive and / or decode (e.g., successfully receive and / or decode) the channel or transport block.

[0066] A burst may be, or may include, e.g., at least a portion of a transmission that may or may need to be transmitted and / or received on a set of resources. A burst may be, or may include, e.g., at least a portion of a channel (e.g., a data channel, a control channel, a random access channel, and / or a broadcast channel, etc.), a signal, a code block, a code block group, or a transport block that may or may need to be transmitted and / or received on a set of resources. A burst may be, or may include, e.g., a set of repetitions, or a subset of a set of repetitions, of a channel, signal, code block, code block group, or transport block that may be transmitted and / or received on a set of resources.

[0067] 2A shows an example process for transmission based on available / allocated resources. In this example, transmission may be based on available resources when the channel is free. At 202, a transmitter (e.g., a WTRU) may receive a grant, assignment, or configuration for a transmission (e.g., an UL transmission). The grant, assignment, or configuration may include a set of transmission parameters and / or a set of resources (e.g., time and / or frequency resources such as subframes or PRBs). For example, a set of M time resources (e.g., M SFs) may be granted, assigned, and / or configured. The M time resources may be contiguous or non-contiguous time resources. The term “allocated,” as discussed herein, may be used to denote granted and / or configured.

[0068] At 204, the transmitter may perform CCA (e.g., full CCA) and determine a start time for a first time resource (e.g., a first subframe), where the first time resource may be the first of the M allocated resources. The start time for transmission may be configured or indicated for the allocated time resource. The start time may be the start of the time resource or the start of a time unit, such as the nth symbol within the time resource. At 205, the transmitter may perform CCA (e.g., short CCA) on the first resource (e.g., the first of the M subframes) immediately before the time at which transmission starts (i.e., the start time).

[0069] If the channel is determined to be free for transmission in the time resource at 206Y, the WTRU may begin transmission in that time resource at 209. If the channel is not free for transmission at 206N, the transmitter may not transmit in that time resource. At 207, the transmitter may determine when it can transmit (i.e., check whether the channel is free by performing CCA) in the next time resource among the M time resources and may postpone transmission until that time.

[0070] At 208, the transmitter may determine whether the transmission fits within the remaining time resources of the M resource allocation (e.g., begin transmitting on the next resource). If the transmitter determines at 208N that the transmission does not fit, the transmitter may not use the remainder of the allocation and may end the process at 213. If the transmitter determines at 208Y that the transmission does fit, the transmitter may transmit on the next resource, for example, after determining at 205 that the channel is available based on performing CCA.

[0071] 2B illustrates some examples and exemplary processes of FIG. 2A in which there is a transmission based on available / allocated resources. As discussed above, the transmitter may receive a grant / allocation of M resources 222 (e.g., 6 subframes numbered 4 through 9), and a transmission 230 (e.g., of a channel or transmission block (TB)) may be K resources in length 224 (e.g., 2 subframes). There may be a total of 12 possible subframes 231 numbered 1 through 12. Subframes 231 with dotted lines may indicate that they are outside the grant M 222, and subframes 231 with solid lines may indicate that they are within the grant M 222.

[0072] In one example 230A, the transmitter may determine that the channel is available for transmission at a certain point in time 226A (e.g., a start time after subframe 7). The transmitter may then determine that the remaining resources, which are the number of resources remaining in that grant between the start time 226A and the end of grant M 222, are equal to or greater than the resources the transmitter may need for transmission 224A. In this example, assuming a transmission K in length (e.g., two subframes), transmission 224A fits into grant 222 for the remaining time indicated by the shaded block (i.e., subframes 8 and 9), and therefore the transmitter may be able to send transmission 224A.

[0073] In one example 230B, the transmitter may perform CCA (e.g., full CCA) and determine that the channel is available for transmission at a certain point in time, in a particular subframe 226B. The transmitter may then determine that the remaining resources (e.g., the number of remaining subframes) in the grant (e.g., one subframe) are less than transmission 224B, and the transmitter cannot transmit. Specifically, the next transmission opportunity is at the end of subframe 8, and because transmission 224B requires two subframes, it does not fit within grant M 222, which has only one subframe remaining between the end of grant M 222 and the next available transmission 226B. As discussed herein, the allocation of M resources may be configured semi-statically (e.g., via semi-persistent scheduling, SPS, etc.) or dynamically (e.g., via a control channel and / or DCI, etc.).

[0074] 3A shows an example process for time-constrained transmission for a set of assigned resources. In some cases, the transmission may have one or more restrictions, such as when a transmitter receives an assignment for a set of M resources and can only use N (e.g., at most N) of the M resources for transmission, where the actual values ​​of M and N may be pre-configured. The M resources may be contiguous in time, and the transmitter may use (e.g., pass through) up to N time-consecutive resources. In some examples, N may be or correspond to MCOT.

[0075] As discussed herein, M and / or N may be configured semi-statically (e.g., via higher layer signaling) or dynamically (e.g., via a control channel and / or DCI). Furthermore, in some examples, M and / or N may be included in or along with the triggering of an UL grant or DCI.

[0076] 3A, at 301, a transmitter (e.g., a WTRU) may receive a configuration of a maximum transmission length N, where N may be a number of resources (e.g., contiguous or adjacent resources) that the transmitter can use for transmission. At 302, the transmitter may receive an assignment (e.g., an UL assignment or grant) for a set of M resources (e.g., M subframes). In this example, N is less than or equal to M, and N may be set to MCOT to meet the MCOT requirement.

[0077] At 304, the transmitter may perform CCA (e.g., full CCA) and determine a start time for a first time resource (e.g., a first subframe), where the first time resource may be the first of the M granted resources. The start time for the transmission may be configured or indicated with respect to the assigned time resource. The start time may be the start of the time resource or the start of a time unit, such as the nth symbol within the time resource.

[0078] At 305, the transmitter may perform CCA (e.g., short CCA) immediately before the start of the first transmission time within the set of M resources (e.g., subframes) and thus determine whether the channel is free and available.

[0079] If the transmitter determines 306Y that the channel is available, the transmitter may transmit on one or more resources within the M allocated resources at 309. The transmitter may transmit on up to N consecutive resources, and the number of consecutive resources on which the transmitter can transmit may be determined (e.g., by the transmitter) based on at least one of the following: M, N, the remaining time resources in the allocation (e.g., when the transmitter determines that the channel is free), the number of resources the transmitter needs or can use for its transmission (e.g., for at least one channel or transport block), and / or the amount of data the transmitter must transmit. For example, the transmitter may transmit on up to N of the M resources after determining that there are sufficient remaining resources for its transmission (e.g., for at least one channel or transport block). In some examples, the transmitter may not recheck channel availability between consecutive (e.g., adjacent) transmissions, but may recheck channel availability if there is a break in transmission.

[0080] If the transmitter determines that the channel is busy at 306N, the transmitter cannot transmit at the start of the first transmission time. At 307, the transmitter can determine the next transmission time (e.g., included in the assignment), if one exists. The transmitter can determine whether the transmitter's transmission fits into the remaining transmission time (e.g., one starting at the next transmission time). When the transmitter determines that the transmission cannot fit into the remaining transmission time at 308N, the transmitter cannot use the remainder of the assignment at 313. When the transmitter determines that the transmission can fit into the remainder of the assignment at 308Y, the transmitter can try again at the next transmission time, and at 305, the transmitter can perform CCA to determine whether the channel is free for transmission before the start of the next transmission time (e.g., included in the assignment).

[0081] Figure 3B shows a visual illustration, along with some examples of the process of Figure 3A, in which time-bounded transmissions are made to a set of allocated resources. At 330, a transmitter may receive an allocation of M resources 322 (e.g., 6 subframes out of a total of 12 subframes 331), and the transmitter's transmission (e.g., of a channel or transmission block) may use K resources 324, indicated by blocks with diagonal lines (e.g., 2 subframes). The transmitter may receive resources for a configured maximum transmission length of N 328 (e.g., 4 subframes). When a channel is busy, it may be indicated by a box 321 with dots. Subframe 331 boxes with dotted lines may indicate they are outside the grant M 322, and any subframe boxes 331 outlined with solid lines may be within the grant M 322.

[0082] In the examples of 330A and 330B, when the transmitter determines that the channel is available for transmission, the remaining resources (e.g., the number of subframes) in the grant M 322 in the assignment (e.g., 5 subframes for 330A and 4 subframes for 330B) may be greater than (or equal to) the maximum transmission length N. Specifically for 330A, based on CCA, the transmitter may determine that the channel is busy in subframe 4, and therefore the start time for transmission may be 326A, and transmission N 324A should fit within the grant M 322. Similarly, for 330B, the start transmission time may be determined to be 326B after the channel is no longer busy, and transmission N 324B should fit within the grant M 322. The transmitter may transmit with up to N 328 (e.g., 4 subframe) resources, but in some examples may transmit less. For example, the transmitter may transmit two transport blocks of length K324 over four resources (i.e., subframes), and therefore the transmitter can transmit two transport blocks. In another example, N may be 3, and only one transmission block can fit on three resources, and therefore only one transmission block will be transmitted by the transmitter.

[0083] If the transmitter has enough data for N resources (eg, subframes), the transmitter can transmit multiple times (eg, multiple consecutive transport blocks).

[0084] In the examples of 330C and 330D, when the transmitter determines that the channel is available for transmission, the number of remaining resources (e.g., subframes) in grant M 322 may be less than the configured maximum value N 328. The transmitter can determine whether it can transmit one or more times (e.g., multiple transport blocks). In both 330C and 330D, the number of remaining subframes in the allocation is not large enough to accommodate two transmissions (e.g., two transport blocks) by the transmitter. In particular, for 330C, the transmitter can determine that the channel is busy until 326C, at which point transmission N 324C only has room for one transport block, and subframe 9 cannot be used. Similarly for 330D, the transmitter can start at 326D, which only leaves room for one transport block for transmission 324D. In another example, the transport block length K can be a different length, such as one, in which case for 330D, for example, three transport blocks can be accommodated after the determined start time 326D.

[0085] In an embodiment, an allocation of resources (i.e., a set of M resources) may be referred to as a transmit opportunity window (TOW) that may be used by a transmitter (e.g., a WTRU or eNB) to send a transmission to a receiver (e.g., an eNB or WTRU). The transmitter (e.g., a WTRU) may complete a transmission in a TOW when, for example, the WTRU determines that a channel (e.g., a frequency channel) may be free and transmits at least one channel (e.g., a data or control channel) or TB in the remaining resources of the TOW allocation. Multiple TOW allocations may be valid until cancelled, such as in semi-persistent scheduling (SPS), or may be configured with a duration or number of TOWs (e.g., a W-set).

[0086] One or more parameters of one or more sets of resource allocations or TOWs may be signaled by higher layer signaling (e.g., RRC signaling, etc.) and / or by a control channel (e.g., in DCI). The parameters may be pre-configured, periodic, scheduled, or triggered aperiodically. The device (e.g., eNB) can configure or indicate to the transmitter parameters, where the parameters can include at least one of the following: the number of time resources (e.g., subframes) per set / TOW (M), the maximum transmission length within a set / TOW (N), the number of sets / TOWs (W) or total duration of the multi-set / TOW assignment, the timing of the assignment (e.g., frame, subframe, slot, etc. of the set / TOW of the multi-set assignment), the time duration / period between successive sets / TOWs (e.g., measured in frames, subframes, slots, etc.), the periodicity of the set / TOW, the offset to the next set / TOW (e.g., in resources or subframes), an indication of the start and / or first set / TOW (e.g., first resource or subframe), an indication of the end and / or last set of resources / TOW (e.g., last resource or subframe), the duration (e.g., M in resources or subframes), and / or an indication of how the assignment can be activated and / or deactivated.

[0087] The transmitter may provide an indication to another entity (e.g., from the WTRU to the eNB or gNB) that the transmitter no longer needs the allocation and / or that the allocation may be released or deactivated. For example, the WTRU may transmit at least one of the following (e.g., in the last transmission) to provide an indication to terminate the allocation: a buffer status report indicating a size of zero, an indication in a control channel (e.g., an UL control channel), a reference signal (e.g., a configured reference signal), a sequence (e.g., a unique or configured sequence), and / or reserved PRACH resources. The transmitter may provide an indication when it has no more data to send. The indication may be used as an end marker for a set / TOW of one or more transmissions. The indication may be provided and / or used to indicate and / or determine the last burst of a split-burst transmission. The transmitter may provide the indication in or along with a transmission (e.g., an UL transmission or a DL transmission), and the receiver may receive the indication.

[0088] In some situations, a device (e.g., an eNB) may allocate or schedule multiple TOWs, which may be discontinuous, for example, when a transmission (e.g., to or by a WTRU) may exceed a time limit (e.g., N, or MCOT limit). The device may, for example, allocate W TOWs, where (e.g., each) TOW includes M time resources, and the transmitter may only transmit using up to N of the M time resources of a TOW. Furthermore, the device (e.g., an eNB) may, for example, indicate multiple start times for aperiodic scheduling. In the case of TOWs with different durations, the device may indicate a duration for one or more (e.g., each) TOW.

[0089] 4A shows an example process of a transmission divided into bursts. As discussed herein, the entire message (e.g., data or control) that a transmitter may wish to transmit may be referred to as a transmission. In some situations, the entire transmission (total message) may not be able to fit into an allocation set of resources (e.g., TOW) (e.g., the transmission may use or need to use more than N resources, or more than the MCOT) and may need to be divided into one or more bursts. The bursts may be organized into a set of one or more bursts, where the burst size and / or number of bursts transmitted for a given TOW are only transmitted with N or fewer resources. In one example, the transmission may be a NB (e.g., NB-IoT), bandwidth-limited (BL), or CE transmission.

[0090] At 401, a transmitter (e.g., an eNB or a WTRU) may receive a configuration of a maximum transmission length of N resources (e.g., time resources). At 402, the transmitter is assigned one or more sets of M resources for one or more transmissions, but may use only N of the M resources.

[0091] At 403, the transmission may be divided (e.g., separated or segmented) (e.g., by the WTRU, eNB, or transmitting device) into a set of B bursts, in which case the transmission needs to or can use K resources (e.g., in time), where K may be less than N; otherwise, each burst may use (e.g., be transmitted on) N resources (e.g., not more than N), which may be pre-configured. The bursts in the set of bursts may be the same size or different sizes. Generally, the transmitter may determine the number / size of bursts for a transmission based on at least one of the following: a) the resource (e.g., the first resource) in the set of resources when the transmitter determines the channel is free; b) the remaining time in the set of resources, for example, when the transmitter determines the channel is free; c) the number of bursts still to be transmitted, which may be B or less; and / or d) N. In some examples, the transmission may be adapted (e.g., padding or rate matching may be used) so that the bursts may be the same size. For example, the transmitter may transmit up to the number of bursts that can fit into the remaining or remaining time (e.g., when the channel is determined to be free or when starting with a transmission opportunity when the channel is determined to be free), but not exceed the MCOT or N (e.g., the maximum allowed number of consecutive time resources (e.g., subframes) that can be used for transmission).

[0092] At 404, the transmitter may perform CCA (e.g., full CCA) and determine a start time for transmitting on the first resource of the TOW. At 405, the transmitter may transmit a subset of B bursts (e.g., B bursts) on up to N of the M resources. サブ CCA (e.g., short CCA) can be used to determine channel availability immediately before transmitting a burst (e.g., a number of bursts).

[0093] As discussed herein, an allocation of one or more sets of M resources that can be used for a transmission can include a finite number of TOWs (e.g., W), or can be allocated until cancelled or deactivated. In some cases, the allocation can be for a particular transmission, and the value of M can be the same or different for different TOWs. Furthermore, the value of N can be the same or different for different TOWs. For example, the value of N can vary (e.g., be configured or reconfigured) depending on the set of resources or for different TOWs.

[0094] If the channel is free at 406Y based on CCA (e.g., short CCA) at 405, the transmitter may transmit one or more bursts (e.g., based on what fits) on the remaining resources, or the fewer of the N resources, in the set of allocated resources M of the TOW at 409. A B I may be included for each burst or set of bursts. If there are no more bursts to transmit from the original burst B at 410N, the transmission process may end at 413. If there are more bursts to transmit from the original burst B at 410Y, the transmitter determines whether there are more TOWs available at 411. If there are more TOWs available at 411Y, the next transmission time is determined at 412, and the process loops back to the CCA check before transmission at 405. If there are no more TOWs available at 411N, the transmission process may end at 413.

[0095] If the channel is not free for transmission at 406N, the next transmission time must be determined at 407. The transmitter can then determine if the burst fits in the remaining time of a given TOW (i.e., set of available resources) at 408. If the burst does not fit at 408N, the transmitter determines if more TOWs are available, as discussed herein, at 411. If the burst fits in the remaining time at 408Y, the process loops back to performing a CCA check at 405 before transmitting.

[0096] 4B shows a further example of FIG. 4A and an exemplary process for transmission using segmented bursts. In the example shown in FIG. 4B, resources may be subframes, the granted M resources 422 may be equal to 6 subframes, all sets of granted resources (i.e., TOW) may be the same, the maximum transmission length N 428 may be equal to 4 subframes, a burst may use one subframe, and a transmission opportunity may start on a subframe boundary.

[0097] In the example of 430A, the transmitter may attempt to send a transmission, where the number of bursts (B) may be 7, and the transmitter may only transmit a maximum of four bursts (N=4) at a given time. The transmitter may determine that a channel is available after subframe 1 of TOW 431A (e.g., at a subframe boundary). The transmitter may transmit N, or four, bursts in TOW 431A because the transmitter must transmit a total of seven bursts, but the maximum it can transmit in a given TOW, or transmit opportunity N 428, is four. As a result, the transmitter cannot use the last subframe of TOW 431A. The transmitter may transmit the remaining bursts (e.g., the remaining three bursts) in TOW 432A, the next TOW in the allocation, if and / or when the channel is available. In the second TOW 432A, no subframes are busy, so the channel is available to transmit at the first available opportunity, and the transmitter can then transmit the remaining three bursts of the seven total bursts. In the subsequent TOW 433A, all transmissions of the bursts have been completed, so there is no need for any further transmissions.

[0098] In the example of 430B, there may be eight bursts. In the first TOW 431B, the transmitter may determine that the channel is busy for the entire TOW 431B. In the second TOW 432B, the transmitter finds that the channel is available in the first transmit opportunity (i.e., subframe 1 of TOW 432B). The transmitter may transmit bursts for the maximum allowed length N 428 (e.g., four subframes). The transmitter may transmit the remaining bursts in the next available TOW (or a later TOW) if and / or when the channel is available. In a slightly later TOW 433B (i.e., the next TOW or a slightly later TOW), the channel may be available in the second transmit opportunity (i.e., subframe 2), and the transmitter may transmit the remaining four bursts of the total eight bursts it needs to transmit.

[0099] In the example of 430C, there may be eight bursts. In the first TOW 431C, the transmitter may determine that the channel is busy until the fifth transmit opportunity (i.e., subframe 5) and may transmit as many bursts as it can fit in the remaining grant M 422 of TOW 431C, which in this example is two bursts. In the second TOW 432C, the transmitter may determine that the channel is immediately free and may transmit the maximum transmission length N 428, which in this example is four bursts, in the first transmit opportunity (i.e., subframe 1 of TOW 432C). The transmitter may transmit the remaining bursts in the next available TOW (or a subsequent TOW) if and / or when the channel is available. In a slightly later set 433C (i.e., the next set, or a slightly later set), the channel is available in the second transmit opportunity (i.e., subframe 2) and the transmitter may transmit the remaining two bursts of the total eight bursts that need to be transmitted.

[0100] In one example, the transmitter may be a WTRU with parameters configured by the base station, and the WTRU may perform CCA before starting the TOW and / or may determine whether the channel is available or will be available for transmission at the start of the TOW. If the channel is determined to be available, the WTRU may transmit on up to N resources (e.g., starting from the start of the TOW). If the channel is determined to be unavailable at the start of the TOW, the WTRU may perform (i.e., continue to perform) CCA for a later transmission. When the WTRU determines that the channel is idle within the TOW and that sufficient resources remain to support the WTRU's transmission, the WTRU may transmit its transmission.

[0101] 5 shows an example transmission process using a burst indicator (BI). Burst indicator and burst ID can be used interchangeably and can be unique for each burst (e.g., burst counter). In one example, different BIs can be transmitted in or with the first and second bursts of a split burst transmission. A BI that can be transmitted in or with a burst can indicate which burst (e.g., which burst number) of the split burst transmission or of a set burst the burst can be.

[0102] A BI may be, include, or comprise one or more (e.g., a set) of a pattern, a signature, a signal (e.g., a reference signal (RS)), or a sequence. The terms signal and / or sequence may be used to denote a signature, a signal, and / or a sequence. A signal may be a reference signal (RS), such as a cell-specific RS (CRS), a demodulation RS (DMRS), a channel state information RS (CSI-RS), among others. A sequence may be a Zadov-Chu sequence. A BI, and / or a signal / sequence (or a set or pattern of signals / sequences) that may be used for a BI may be unique and / or may be for or configured for a WTRU, an objective, a channel or set of channels, a burst, a set of bursts, a transmission, a split-burst transmission, among others. The configuration may be by higher layer signaling (e.g., RRC signaling) and / or physical layer signaling.

[0103] For example, the BI may be transmitted in or along with an UL burst transmission and may be indicated or identified in a DCI. The DCI may be or include, for example, an UL grant or allocation for a full transmission, which may be a split-burst transmission. The WTRU may transmit the indicated (e.g., identified) BI in a full burst transmission or at least one of a split-burst transmission.

[0104] Alternatively, the BI may be transmitted in or along with a DL burst transmission and may be indicated or identified in a DCI. The DCI may be or include a DL grant or allocation for a complete transmission, which may be, for example, a split burst transmission. The WTRU may combine one or more bursts that the WTRU may receive and that may include or be associated with a transmission of the indicated (e.g., identified) BI.

[0105] The one or more signals / sequences or patterns of one or more signals / sequences of a BI may be at least one of the following: WTRU-specific (e.g., configured for the WTRU), burst or split-burst-specific (e.g., configured for and / or associated with burst or split-burst transmission), cell-specific (e.g., configured for a cell), group-specific, channel-specific (e.g., specific to one or more channels, such as one or more common channels), channel-type-specific, and / or HARQ process or HARQ process ID-specific (e.g., configured for and / or associated with a HARQ process or HARQ process ID).

[0106] In one example, the WTRU may transmit a BI (e.g., an HARQ process ID) configured for an HARQ process if the WTRU is able to transmit a burst for the HARQ process. The WTRU may combine one or more bursts that may be associated with an HARQ process based on receiving a BI in or along with one or more bursts that may indicate that the burst is associated with an HARQ process.

[0107] The example shown in FIG. 5 may be similar to the process described with respect to FIGS. 4A and 4B, except that the transmission parameters are different and a burst indicator / burst identification may be indicated. Associated control signaling may be transmitted for each burst, and the associated control signaling may include a BI. Initially, a transmitter (e.g., a WTRU) may be configured with (e.g., receive a configuration for) one or more parameters associated with dividing / segmenting at least one transmission or transmission type into bursts. For a given transmission, the transmitter (e.g., a WTRU) may receive and process configuration information in advance (e.g., determine the number of bursts for a given transmission). The transmitter may receive a configuration, which may include at least one parameter, via higher layer signaling (e.g., RRC signaling) and / or physical layer signaling (e.g., via a control channel and / or DCI).

[0108] The configuration (e.g., one or more parameters) may include at least one of the following: maximum transmission length / time resources within a set (N), code block size (e.g., when a burst is based on a code block), burst size (e.g., in time, number of resources, number of code blocks, or number of repetitions), minimum and / or maximum burst size, number of bursts (B), whether to insert a CRC per burst, scheduling parameters (e.g., MCS, frequency resources, transmit power, etc.) for the burst, set of bursts, or subset of bursts, number of time resources (i.e., time units) to which a burst may be mapped (e.g., number of slots, minislots, OFDM / DFT-s-OFDM symbols, subframes, and the like), one or more parameters capable of identifying and / or configuring a signature, signal, scrambling code, sequence, and / or pattern that may be included in or with a burst transmission, and / or one or more parameters capable of identifying and / or configuring a burst indicator (BI) that may be included in or with a burst transmission.

[0109] For one or more parameters that can identify and / or configure a signature, signal, scrambling code, sequence, and / or pattern that may be included in or with a burst transmission, each burst in a set of bursts may have a burst identification (e.g., a burst ID), and the burst ID may be used to scramble the bits in each burst. For example, the coded bits of a burst may be scrambled with its associated burst ID (e.g., the burst ID may be used to start the scrambling code for the burst).

[0110] Referring to the example of FIG. 5, a transmitter may send a transmission 530 using a set of resources, such as a multi-subframe grant M 522. The transmission 530 may be broken down into bursts based on a received configuration, such as a burst size 525 of 2 subframes. A maximum transmission length N 528 may be set to MCOT and may be equal to 4 subframes. In this example, the entire uplink transmission 530 may include 8 subframes and may be broken down into 4 bursts. Each burst may have a burst ID 539, such as 501, 502, 503, and 504, and each burst may contain 2 subframes. For the first TOW 531, the start time can be determined by performing a CCA (e.g., a full CCA), where the transmitter can determine that the channel will not be busy after subframe 4, at which point the transmitter determines how many bursts can fit into the remaining grant of resources 522 when the channel (e.g., frequency channel) is determined to be usable or available (e.g., when CCA is determined to pass). For example, in the first TOW 531, a first burst with burst ID 501 is transmitted in subframes 5 and 6, and subframe 7 cannot have a burst. The process can continue until the entire UL transmission 530 is sent.

[0111] In the second TOW 532, the channel is busy until subframe 6, meaning that there are not enough subframes left in the grant M 522 to send any bursts. The process continues to the third TOW 533, where after subframe 1 the channel is free and three bursts can fit into the remaining grant M 522, but only the next two bursts 502 and 503 can be sent because there is an MCOT 528 of four subframes (i.e., two bursts). In the next TOW 534, the channel is immediately free and the last burst, burst ID 504, can be sent without leaving any more bursts in the remaining SF to send since the entire UL transmission 530 has been sent.

[0112] In the example of FIG. 5, the burst ID may be used to scramble bits in each burst. Furthermore, for one or more parameters that can identify and / or configure a signature, signal, scrambling code, sequence, and / or pattern that may be included in or with a burst transmission, a DM-RS sequence / pattern for the burst may be determined based on its associated burst ID. In an example, a burst may be transmitted with an associated DM-RS, and the associated DM-RS sequence / pattern may be determined based on the burst ID. In such a case, at least one of the following may be applied: one or more cyclic shifts of a base sequence (e.g., a Zadov-Chu sequence, a Golay sequence, an m-sequence) may be used as the DM-RS sequence, and the cyclic shift for the DM-RS may be determined based on the burst ID; and / or one or more DM-RS patterns may be used based on interleaved frequency domain multiplexing (IFDM), and the DM-RS pattern may be determined based on a frequency offset, and the frequency offset for the DM-RS (e.g., the DM-RS pattern) may be determined based on the burst ID.

[0113] A CRC may be used or appended to each burst for one or more parameters that identify and / or configure a burst indicator (BI) included in or with the burst transmission, and the burst indicator (BI) may be transmitted implicitly using CRC scrambling. For example, the CRC may be scrambled with the associated BI at the transmitter, and the receiver may descramble the CRC with the associated BI for CRC checking.

[0114] Further with respect to one or more parameters that may identify and / or configure a burst indicator (BI) that may be included in or with a burst transmission, a subset of resource elements (REs) in the burst may be reserved (e.g., REs adjacent to the DM-RS), and the BI may be transmitted on the subset of REs.

[0115] In some cases, one or more bursts of a split-burst transmission can be the same. For example, the first burst of a transmission, which may be divided into B bursts, can be a duplicate of the second burst of the transmission. Furthermore, if a burst may be used to convey a repetition of a signal or channel (e.g., a CE repetition), one or more (e.g., all) bursts of a split-burst transmission can be the same (e.g., comprise, include, or convey the same bits, which may be coded bits). One or more bursts can be the same with or without a BI that may be included in or with the burst transmission. A repetition of a transmission can include repeated transmission of the same information bits, but the redundancy version of the coded bits can be different in each repetition. For example, the same information bits can be channel coded, and different portions of the coded bits can be transmitted based on the number of repetitions.

[0116] In another example, a first burst of a split-burst transmission may carry a subset of the bits or symbols of the transmission, and a second burst of the split-burst transmission may carry a different subset of the bits or symbols of the transmission. For example, a transport block (e.g., one that allows multiple resources to be used for a transmission) may be partitioned into B bursts, where each burst may carry a subset (e.g., a different subset) of the bits or symbols of the transport block. Further, partitioning may be performed at the code block level, where a burst may comprise, include, or carry one or more code blocks of a transmission (e.g., of a transmission block).

[0117] 6 shows an example of a process for receiving a transmission using a bit indicator. At 601, the receiver may receive a configuration for a BI and / or determine a BI or set of BIs to use for receiving a split-burst transmission. At 602, the receiver may monitor a BI, or at least one BI of a set of BIs, in one or more resources (e.g., subframes). The receiver may attempt to receive one or more bursts of the split-burst transmission. If a BI is not received at 603N and this is the last resource or set of resources / TOWs to monitor at 606Y, the process will end at 607. If a BI is not received at 603N and it is not the last resource or set of resources / TOWs to monitor at 606N, the process may return to monitoring 602.

[0118] If a BI is received at 603Y, the receiver will receive, store, and / or combine the associated burst with one or more other bursts of the split-burst transmission at 604. If the bursts carry a subset (e.g., of bits) of a complete transmission, the receiver can combine (e.g., assemble or concatenate) the bursts to obtain, receive, and / or decode (e.g., successfully receive and / or decode) the complete transmission. If the bursts carry repetitions (e.g., of bits) of a transmission, the receiver can combine (e.g., soft combine) the bursts to receive and / or decode (e.g., successfully receive and / or decode) the transmission. For example, a BI may be provided (e.g., transmitted) and / or used (e.g., by a transmitter) to enable the receiver to combine bursts of a split-burst transmission. The receiver can use at least one BI to determine when and / or how to combine one or more bursts of a split-burst transmission.

[0119] If the last burst or split burst transmission is successfully received at 605Y, the process may end at 607. If the last burst or split burst transmission is not successfully received at 605N, the receiver determines whether this is the last resource or set of resources / TOW to monitor.

[0120] Generally, a receiver may monitor resources (e.g., each resource), such as subframes or slots, for a BI. For example, a WTRU may monitor each resource, which may be at least one of DL resources, resources configured for burst transmission and / or reception, and / or resources configured for transmission and / or reception of a particular burst transmission or a type of burst transmission (e.g., common or WTRU-specific transmission). When the receiver receives a BI, it may receive an associated burst and / or combine the associated burst with a previously received burst that may be associated with the same BI.

[0121] The BIs may be received in several possible ways, for example, the BIs may be included in (e.g., as part of) a burst transmission (e.g., each burst transmission), the BIs may precede (e.g., be transmitted and / or received before) a burst transmission or set of burst transmissions, the BIs may follow (e.g., be transmitted and / or received after) a burst transmission or set of burst transmissions, the BIs may be transmitted and / or received during a burst transmission, and / or the BIs (e.g., BI transmissions) may be interleaved and / or overlap (e.g., at least partially) in time and / or frequency with the burst transmissions.

[0122] In some cases, the receiver can successfully receive the BI in or based on a single transmission of the BI without repetition (e.g., in multiple bursts). The BI enables the receiver to determine or detect the presence of a burst, for example, to combine with one or more previously received bursts. The receiver can determine that a burst is present (e.g., on a resource) based on reception of the BI (e.g., in or with a resource). The receiver can use the BI to combine (e.g., assemble or soft-combine) the received burst with a previously received burst (e.g., based on the received BI). For example, a transmission (e.g., of a channel or transport block) can be repeated over multiple bursts.

[0123] Repeated bursts and / or BIs may be used and / or provided (e.g., when CE is used). The BI may be used by a receiver to determine that a transmission may be a burst of a split-burst transmission and / or a repetition of a transmission. The receiver may combine, or may determine to combine, a first burst or transmission with a second burst or transmission based on receiving the BI along with the first and / or second burst and / or transmission. Furthermore, the receiver may combine a set of repetitions of a BI that may be received in or with a set of bursts transmitted together or consecutively to receive a BI (e.g., successfully).

[0124] A BI (e.g., the same BI) may be transmitted in one or more of the bursts of a split-burst transmission, such as in all of the soft-combinable bursts or repetitions of a transmission that are combined to successfully receive the burst or transmission. A BI may be transmitted in or with a set of bursts, e.g., a BI may be repeated in or with each of a set of bursts that may be transmitted together or consecutively in time.

[0125] In an example, a BI may be transmitted and / or received on a set of time / frequency resources (e.g., of a transmission or burst transmission). The time / frequency resources may be resource elements (REs). An RE may include a frequency or a set of subcarriers of at least one symbol (e.g., in time). The time / frequency resources that may be used for BI transmission may differ from the resources used for burst transmission. For example, the burst transmission may be rate-matched around the time / frequency resources (e.g., REs) that may be used for BI transmission. Furthermore, any increment of time resources discussed herein may include a BI. Furthermore, the BI may be present in or included in control information (e.g., DL or UL control information) that may be transmitted on a control channel and / or along with the burst.

[0126] The density of the BI signals / sequences (e.g., in time / frequency resources such as REs) or the pattern of one or more signals / or sequences may depend on the CE level required or available. The pattern may be repeated in a time unit or time resource (e.g., subframe or slot) to achieve a gain (e.g., a desired gain). The density may be higher (e.g., more CEs) for higher CE levels. The pattern repetition may be increased or higher for higher CE (e.g., more CEs) levels.

[0127] In some cases, non-repeated bursts and / or BIs may be provided and / or used. Non-repeated bursts and / or BIs may be used for NB transmissions, such as NB-IoT transmissions, where multiple resources may be used to transmit a transmission (e.g., a channel or transmission block). Non-repeated bursts and / or BIs may be used, for example, when a CE is unavailable.

[0128] In some cases, the BI may be associated with or responsive to a WTRU-ID or C-RNTI. The WTRU may use or combine (e.g., only combine) one or more bursts that may be intended for it. The WTRU may determine that a burst may be intended for it based on a BI that may be associated with and / or transmitted in or with the burst. Further, the WTRU may transmit a BI in or with the burst based on its WTRU-ID or C-RNTI. The eNB may determine that a burst may be from a WTRU (e.g., a particular WTRU) based on a BI that may be transmitted in or with the burst.

[0129] In some cases, a BI may be associated with or configured for a common channel. For example, a WTRU may determine that a burst may be associated with or configured for a common channel based on a BI associated with, transmitted on, or with the burst, and / or that may be received by the WTRU on or with the burst. The WTRU may use or combine, or only combine, one or more bursts that the WTRU may determine to be associated with or configured for a common channel, e.g., to receive and / or decode (e.g., successfully receive and / or decode) the common channel.

[0130] Although features and elements are described above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with the other features and elements. Additionally, the methods described herein can be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution on a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor storage devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor associated with software can be used to implement a radio frequency transceiver used in a WTRU, a WTRU, a terminal, a base station, an RNC, or any host computer. [Industrial Applicability]

[0131] The present invention can be used in wireless communication.

Claims

1. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: receiving resource allocation information for a set of transmissions, each transmission in the set of transmissions being allocated for transmission of at least one repetition of a transport block, the resource allocation information indicating a number of time resources allocated for each of the set of transmissions; transmitting the transport block using a first transmission of the set of transmissions, the transport block being transmitted in the first transmission using the number of time resources indicated by the resource allocation information; determining that at least one time resource associated with a second transmission of the set of transmissions is not available for transmission by the WTRU; transmitting the transport block using the second transmission of the set of transmissions, the transport block being transmitted in the second transmission using a number of time resources that is less than the number indicated by the resource allocation information based on the determination that at least one time resource associated with the second transmission of the set of transmissions was not available for transmission by the WTRU; A method for providing the above.

2. 10. The method of claim 1, wherein the number of time resources allocated for each transmission in the set of transmissions corresponds to a number of Orthogonal Frequency Division Multiple Access (OFDM) symbols.

3. 10. The method of claim 1, wherein the resource allocation information is received in downlink control information (DCI).

4. The method of claim 1 , wherein the resource allocation information indicates the number of the sets of transmissions utilized for repetition of the transport block.

5. 10. The method of claim 1, wherein at least one transmission of the set of transmissions is utilized for transmitting multiple repetitions of the transport block.

6. performing a listen-before-talk (LBT) operation prior to transmitting the transport block using the first transmission of the set of transmissions. The method of claim 1 further comprising:

7. The method of claim 1 , wherein each transmission in the set of transmissions is consecutive in time.

8. 1. A wireless transmit / receive unit (WTRU), comprising: a processor and a transmitter; receiving resource allocation information for a set of transmissions, each transmission of the set of transmissions being allocated for transmission of at least one repetition of a transport block, the resource allocation information indicating a number of time resources allocated for each of the set of transmissions; transmitting the transport block using a first transmission of the set of transmissions, the transport block being transmitted in the first transmission using the number of time resources indicated by the resource allocation information; determining that at least one time resource associated with a second transmission of the set of transmissions is not available for transmission by the WTRU; Transmitting the transport block using the second transmission of the set of transmissions, the transport block being transmitted in the second transmission using a number of time resources that is less than the number indicated by the resource allocation information based on the determination that at least one time resource associated with the second transmission of the set of transmissions was not available for transmission by the WTRU. Processor configured to A WTRU comprising:

9. 10. The WTRU of claim 8, wherein the number of time resources allocated for each transmission of the set of transmissions corresponds to a number of Orthogonal Frequency Division Multiple Access (OFDM) symbols.

10. The WTRU of claim 8 , wherein the resource allocation information is received in downlink control information (DCI).

11. The WTRU of claim 8 , wherein the resource allocation information indicates the number of the sets of transmissions utilized for repetition of the transport block.

12. The WTRU of claim 8 , wherein each transmission in the set of transmissions is associated with a respective redundancy version of the transport block.

13. The WTRU of claim 8, wherein at least one transmission of the set of transmissions is utilized for transmitting multiple repetitions of the transport block.

14. The processor: performing a listen-before-talk (LBT) operation prior to transmitting the transport block using the first transmission of the set of transmissions. The WTRU of claim 8 further configured to:

15. The WTRU of claim 8 , wherein each transmission in the set of transmissions is consecutive in time.

16. The WTRU of claim 8 , wherein the first transmission of the set of transmissions is a repetition.

17. 1. A method implemented by a base station, comprising: transmitting resource allocation information for a set of transmissions, each transmission of the set of transmissions being allocated for the transmission of at least one repetition of a transport block, the resource allocation information indicating a number of time resources allocated for each of the set of transmissions; receiving the transport block using a first transmission of the set of transmissions, the transport block being received in the first transmission using the number of time resources indicated by the resource allocation information; receiving the transport block using a second transmission of the set of transmissions, the transport block being received in the second transmission using a number of time resources that is less than the number indicated by the resource allocation information; A method for providing the above.

18. 20. The method of claim 17, wherein the number of time resources allocated for each transmission in the set of transmissions corresponds to a number of Orthogonal Frequency Division Multiple Access (OFDM) symbols.

19. 20. The method of claim 17, wherein the resource allocation information is received in downlink control information (DCI).

20. 20. The method of claim 17, wherein at least one transmission of the set of transmissions is utilized for transmitting multiple repetitions of the transport block.

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