Reducing Latency in Physical Channels in LTE Networks

Abstract

To reduce latency in a wireless network.SOLUTION: A wireless transmit / receive unit (WTRU) may monitor downlink short transmission time intervals (sTTIs) for an sTTI physical downlink control channel (sPDCCH) region. The WTRU may determine the sPDCCH region from a set of candidate sPDCCH regions for an uplink grant. The sPDCCH may be determined based on a WTRU-specific parameter.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present invention relates to wireless communications. [Background technology]

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 315,490, filed March 30, 2016, U.S. Provisional Patent Application No. 62 / 334,888, filed May 11, 2016, and U.S. Provisional Patent Application No. 62 / 377,181, filed August 19, 2016, the contents of which are incorporated herein by reference in their entireties.

[0003] In Long Term Evolution (LTE) or LTE-Advanced (LTE-A) networks, reduced latency is desired for applications such as alarm systems, automotive safety, factory systems, and machine-type communications (MTC). Additionally, gaming and real-time applications such as voice over LTE (VoLTE), video telephony, and video conferencing can also benefit from reduced latency. Scheduling grant acquisition time, transmission time interval (TTI), processing time, hybrid ARQ (HARQ) round-trip time (RTT), and the like can contribute to end-to-end delay. Therefore, it is desirable to reduce latency in wireless networks by addressing these and other factors that can contribute to delay. Summary of the Invention

[0004] A wireless transmit / receive unit (WTRU) may send transmissions to a network or evolved Node B that may significantly or partially overlap in time. Scaling may be utilized to avoid exceeding a maximum power or energy level for or during a transmission time interval (TTI) or portion of a TTI. The WTRU may be further configured to determine short TTI (sTTI) time resources within a time period comprised of a subframe, radio frame, slot, symbol, etc. to utilize for control or data transmissions where latency may be reduced. Additionally, power headroom (PH) reporting may utilize the TTI or sTTI. [Brief explanation of the drawings]

[0005] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which: [Figure 1A] FIG. 1 is a system diagram of an exemplary communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram of an example wireless transmit / receive unit (WTRU) that may be used within the communication system shown in FIG. 1A. [Figure 1C] 1B is a system diagram of an example radio access network and an example core network that may be used within the communication system shown in FIG. 1A. [Figure 2] FIG. 1 illustrates an example of physical resource block (PRB) mapping for a physical uplink control channel (PUCCH) transmission or PUCCH format transmission. [Figure 3] FIG. 1 illustrates an example of physical uplink shared channel (PUSCH) resource mapping. [Figure 4] FIG. 1 is a diagram illustrating an example of a time division duplex (TDD) special subframe configuration. [Figure 5] FIG. 1 illustrates an example of a short transmission time interval (sTTI) gap indication. [Figure 6]FIG. 10 shows an example of a multi-gap sTTI display. [Figure 7] A figure showing an example of an sTTI resource configuration within the guard period (GP) of a subframe. [Figure 8] FIG. 1 illustrates an example of a short or sTTI PUCCH (sPUCCH) resource configuration provided within a downlink subframe or PRB. [Figure 9] FIG. 1 illustrates an example of a two-symbol short or sTTI PUCCH (sPUCCH). [Figure 10] FIG. 10 is a diagram illustrating an example of a three-symbol sPUCCH. [Figure 11] FIG. 10 is a diagram illustrating an example of a four-symbol sPUCCH. [Figure 12] FIG. 10 is a diagram illustrating an example of a signal structure for a one-symbol sPUCCH. [Figure 13] FIG. 1 illustrates an example signal structure for a multi-symbol sPUCCH without an UL reference signal. [Figure 14] FIG. 1 illustrates an example of a signal structure for a one-symbol sPUCCH with repetition over several resource blocks (RBs). [Figure 15] FIG. 1 illustrates an example of short or sTTI PUSCH (sPUSCH) scheduling with one or more associated short or sTTI Physical Downlink Control Channel (sPDCCH) regions. [Figure 16] FIG. 10 is a diagram illustrating an example of association between an sPUSCH and at least one sPDCCH for HARQ-ACK reception when the UL sTTI length and the DL sTTI length are different. [Figure 17] 1 illustrates an example of an association of an sPUCCH for HARQ-ACK transmission with at least one short or sTTI physical downlink shared data channel (sPDSCH) when the UL sTTI length and the DL sTTI length are different. [Figure 18] FIG. 10 is a diagram illustrating an example of a collision occurring between a PUCCH and an sPUCCH. [Figure 19] FIG. 1 is a diagram illustrating an example of normal HARQ (nHARQ) transmission on an sPUCCH. [Figure 20] FIG. 1 illustrates an example of overlapping or parallel TTIs. [Figure 21] FIG. 1 illustrates an example of a power headroom (PH) report. [Figure 22] FIG. 10 is a diagram illustrating an example of determining an sPDCCH region. DETAILED DESCRIPTION OF THE INVENTION

[0006] Any element shown or described in the figures accompanying this specification may be implemented by one or more functions or components in hardware, software, firmware, etc. Moreover, in the examples accompanying this specification, a transmitter may be a transceiver or part of multi-component hardware where appropriate. A receiver may be a transceiver or part of multi-component hardware where appropriate. Finally, the term data or information in any of the examples accompanying this specification may include control data, control information, control packets, user data, user information, payload data, payload information, data packets, general data, or general information.

[0007] 1A is a diagram of an example communication system 100 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, broadcasts, etc., to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ 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), orthogonal frequency division multiplexing (OFDM), single-carrier FDMA (SC-FDMA), etc.

[0008] 1A , communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, or 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, or network elements. Each of WTRUs 102a, 102b, 102c, or 102d may be any type of device configured to operate or communicate in a wireless environment. By way of example, WTRUs 102a, 102b, 102c, or 102d may be configured to transmit or receive wireless signals and may include user equipment (UE), a mobile station, a fixed unit or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, consumer electronics, etc. The signal may be or include a channel, a physical channel, a control channel, a data channel, a physical channel that may be a control channel or a data channel, etc. The signal may be or include a reference signal (RS). The terms signal and channel may be used interchangeably.

[0009] The communications system 100 may also include a base station 114a and a base station 114b. Each of the base stations 114a or 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, or 102d to facilitate access to one or more communications networks, such as the core network 106, the Internet 110, or other networks 112. By way of example, the base station 114a or 114b may be a base transceiver station (BTS), a Node B, an eNodeB, a Home Node B, a Home eNodeB, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a or 114b are each shown as a single element, it will be understood that the base station 114a or 114b may include any number of interconnected base stations or network elements.

[0010] The base station 114a may be part of the RAN 104, which may also include other base stations or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a or 114b may be configured to transmit or receive wireless signals within a particular geographic area, sometimes 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 employ multiple-input multiple-output (MIMO) technology and thus utilize multiple transceivers for each sector of the cell.

[0011] The base station 114a or 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, or 102d over the air interface 116, which may be any suitable wireless communications 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).

[0012] More particularly, as mentioned above, the communications system 100 may be a multiple-access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, or 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 (W-CDMA). W-CDMA may include communications protocols such as High Speed ​​Packet Access (HSPA) or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) or High Speed ​​Uplink Packet Access (HSUPA).

[0013] In another embodiment, the base station 114a and the WTRUs 102a, 102b, or 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may use Long Term Evolution (LTE) or LTE-Advanced (LTE-A) to establish the air interface 116. Additionally, for the example provided herewith, the WTRU 102a may utilize sidelink resources or frequencies to communicate with the WTRUs 102b or 102c.

[0014] In other embodiments, the base station 114a and the WTRUs 102a, 102b, or 102c may implement a wireless 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), Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0015] The base station 114b in FIG. 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may utilize any suitable RAT for facilitating wireless connectivity in a local area, such as a business, home, vehicle, campus, etc. In one embodiment, the base station 114b and the WTRU 102c or 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 WTRU 102c or 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 WTRU 102c or 102d may utilize a cellular-based RAT (e.g., W-CDMA, cdma2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114 b may not be required to access the Internet 110 via the core network 106 .

[0016] The RAN 104 may be in communication with the core network 106, which may be any type of network configured to provide voice, data, application, or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, or 102d. For example, the core network 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., or may perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be appreciated that the RAN 104 or the core network 106 may be in direct or indirect communication with other RANs employing the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize E-UTRA radio technology, the core network 106 may also be in communication with another RAN (not shown) employing GSM radio technology.

[0017] The core network 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, or 102d to access the PSTN 108, the Internet 110, 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 networks 112 may include wired or wireless communication networks owned or operated by other service providers. For example, the network 112 may include another core network connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0018] Some or all of the WTRUs 102a, 102b, 102c, or 102d in the communications system 100 may include multi-mode capabilities, i.e., the WTRUs 102a, 102b, 102c, or 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may employ cellular-based wireless technology and a base station 114b that may employ IEEE 802.11 wireless technology.

[0019] 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B, 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 above elements while remaining consistent with an embodiment.

[0020] 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), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, or any other function 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. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0021] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit or receive RF signals. In another embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit or receive, for example, IR signals, UV signals, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and receive both RF signals and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit or receive any combination of wireless signals.

[0022] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More particularly, the WTRU 102 may employ MIMO technology. 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.

[0023] The transceiver 120 may be configured to modulate signals to be 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 via multiple RATs, such as, for example, UTRA and IEEE 802.11.

[0024] 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, 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, 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 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, etc. 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 a home computer (not shown).

[0025] The processor 118 may receive power from the power source 134 and may be configured to distribute or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0026] 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 position of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116, or may determine its location based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0027] The processor 118 may further be coupled to other peripherals 138, which may include one or more software or hardware modules that provide additional features, functionality, 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, etc.

[0028] 1C is a system diagram of the RAN 104 and the core network 106 according to one embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, or 102c over the air interface 116. The RAN 104 may also be in communication with the core network 106.

[0029] The RAN 104 may include an eNodeB 140a, 140b, or 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, or 140c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, or 102c over the air interface 116. In an embodiment, the eNodeBs 140a, 140b, or 140c may implement MIMO technology. Thus, the eNodeB 140a may use multiple antennas, for example, to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0030] Each of the eNodeBs 140a, 140b, or 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 in the uplink (UL) or downlink (DL), etc. As shown in FIG. 1C, the eNodeBs 140a, 140b, or 140c may communicate with each other over an X2 interface.

[0031] 1C may include a mobility management entity (MME) gateway 142, a serving gateway 144, and a packet data network (PDN) gateway 146. Although each of the above elements is shown as part of the core network 106, it will be understood that any of these elements may be owned or operated by an entity other than the core network operator.

[0032] The MME 142 may be connected to each of the eNodeBs 140a, 140b, or 140c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 142 may be responsible for authenticating users of the WTRUs 102a, 102b, or 102c, bearer activation / deactivation, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, or 102c, etc. The MME 142 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or W-CDMA.

[0033] The serving gateway 144 may be connected to each of the eNodeBs 140a, 140b, or 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 WTRU 102a, 102b, or 102c. The serving gateway 144 may also perform other functions, such as anchoring the user plane during inter-eNodeB handover, triggering paging when downlink data is available for the WTRU 102a, 102b, or 102c, and managing and storing the context of the WTRU 102a, 102b, or 102c.

[0034] The serving gateway 144 may also be connected to a PDN gateway 146, which may provide the WTRU 102a, 102b, or 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRU 102a, 102b, or 102c and IP-enabled devices.

[0035] The core network 106 may facilitate communication with other networks. For example, the core network 106 may provide the WTRU 102a, 102b, or 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communication between the WTRU 102a, 102b, or 102c and traditional landline 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 serves as an interface between the core network 106 and the PSTN 108. In addition, the core network 106 may provide the WTRU 102a, 102b, or 102c with access to other networks 112, which may include other wired or wireless networks owned or operated by other service providers.

[0036] The other network 112 may be further 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 be in communication with multiple access points (APs) 170a or 170b. Communication between the access router 165 and the APs 170a or 170b may be via wired Ethernet (IEEE 802.3 standard) or any type of wireless communication protocol. The AP 170a may be in wireless communication over an air interface with the WTRU 102d.

[0037] In the examples provided herein, the WTRU 102 may be configured to determine a short TTI (sTTI) time resource within a time period. The sTTI may be a subframe, radio frame, slot, time slot, symbol, multiple symbols, OFDM symbol, multiple OFDM symbols, etc. The terms time or time period may be interchanged with symbol in the disclosure herein. The WTRU may transmit a single physical uplink control channel (PUCCH) comprising multiple short or sTTI hybrid automatic repeat request (sHARQ) transmissions along with one or more regular HARQ transmissions. Additionally, transmissions by the WTRU may be scaled to avoid exceeding a maximum power level. The scaling may comprise scaling the power of a channel, frequency, time slot, symbol, etc., e.g., a calculated power. The WTRU may also be capable of, or may be configured to, perform a power headroom (PH) reporting (PHR) procedure using the nTTI, the sTTI, or a combination of both. The nTTI may be a nominal, normal, or regular TTI or subframe, such as an LTE / LTE-A TTI or subframe. The nTTI may be a TTI longer than the sTTI. The duration of the nTTI may be any value, such as 1 ms or any other duration. The WTRU may receive an indication to perform a PHR procedure, including a resource grant for uplink transmission. In response to receiving the indication, the WTRU may transmit a PH report in the indicated resource grant. The resource grant may indicate the nTTI, the sTTI, or a combination of both to utilize. The nTTI may be of the first serving cell, and the short, or sTTI, may be of the second serving cell. The first and second serving cells may be the same or different serving cells. The WTRU may be capable of or configured to aggregate the first and second serving cells.

[0038] Also, in the examples provided herein, the PUCCH may be used for one or more HARQ-ACK transmissions or reports, which may be associated with one or more Physical Downlink Shared Data Channel (PDSCH) transmissions, one or more Scheduling Request (SR) transmissions, or one or more Channel State Information (CSI) transmissions. One or more PUCCH formats may be defined, determined, or used, for example, based on information carried in the PUCCH. For example, a PUCCH format that can carry HARQ-ACK information (e.g., only HARQ-ACK information) may be referred to as PUCCH format 1a or PUCCH format 1b.

[0039] 2 is an example of a physical resource block (PRB) mapping 200 for a PUCCH transmission or PUCCH format transmission. The PUCCH may be allocated with respect to a physical downlink control channel (PDCCH). The physical resources that may be used for the PUCCH depend on one or more parameters that may be provided by a higher layer, such as a radio resource control (RRC) layer, e.g.,

[0040]

number

[0041] and

[0042]

number

[0043] The parameter

[0044]

number

[0045] (however,

[0046]

number

[0047] A PRB (which may be ≧0) may be or represent a frequency resource, such as a bandwidth in frequency. A PRB or resource block (RB) may be or include a set of subcarriers, such as 12 subcarriers, which may be within or related to the system bandwidth. Scheduling or resource allocation may be in terms of RBs. An RB may represent or correspond to a set of one or more time units. For example, an RB may correspond to a TTI length or a portion of a TTI length. Frequency resources may be defined, allocated, or represented in terms of a PUCCH format or PRBs that can be configured, determined, or used for PUCCH format transmission. Examples of PUCCH formats include 1 / 1a / 1b, 2 / 2a / 2b, and 3. PRBs and RBs may be interchangeable in embodiments and examples herein.

[0048] A PUCCH transmission or PUCCH format transmission may occur in one or more slots or time slots. There may be two slots in a subframe. A PUCCH or PUCCH format transmission may occur in each slot of a subframe. Parameters

[0049]

number

[0050] may be used to determine the number of cyclic shifts that may be used for a PUCCH format, such as PUCCH format 1 / 1a / 1b, in a physical resource block that may be configured for a mix of PUCCH formats, which may be, for example, a mix of formats 1 / 1a / 1b and 2 / 2a / 2b.

[0051]

number

[0052] The value of can be in the range {0,1,...,7}

[0053]

number

[0054] may be an integer multiple of

[0055]

number

[0056] can be provided or signaled by higher layers. A mixed resource block can be, for example,

[0057]

number

[0058] (e.g., there may be non-mixed resource blocks). A resource block, e.g., one resource block or at most one resource block, may support a mix of PUCCH formats, such as PUCCH formats 1 / 1a / 1b and 2 / 2a / 2b, within a slot, e.g., each slot.

[0059] The resources that may be used for transmitting PUCCH formats 1 / 1a / 1b, 2 / 2a / 2b, and 3 are denoted by non-negative indices, respectively.

[0060]

number

[0061] ,

[0062]

number

[0063] , and

[0064]

number

[0065] Slot n can be represented by s physical resource block n that can be configured or used for PUCCH transmission or PUCCH format transmission in PRB For example,

[0066]

number

[0067] The value of m may be determined based on the PUCCH format. For example, for PUCCH formats such as PUCCH formats 1, 1a, and 1b, the following may be used to determine m:

[0068]

number

[0069] For PUCCH formats such as PUCCH formats 2, 2a, and 2b, the following may be used to determine m:

[0070]

number

[0071] For a PUCCH format such as PUCCH format 3, the following may be used to determine m:

[0072]

number

[0073] In the example of FIG. 2, PRB mapping for PUCCH transmission is shown as being based on a parameter m within a subframe.

[0074] A shortened PUCCH format may be provided or used. The last SC-FDMA symbol in the second slot of a subframe may be left empty when a shortened PUCCH format is used. For example, a shortened PUCCH format may be used when there may be simultaneous transmission of a sounding reference signal (SRS) and a PUCCH transmission or PUCCH format transmission. Such a configuration can be utilized for PUCCH format 1, 1a, 1b, or 3 transmission, or with one serving cell.

[0075] 3 is an example of a physical uplink shared channel (PUSCH) resource mapping 300 within a PRB and uplink subframe 302. The PUSCH may be used for transmission of data 314. A demodulation reference signal (DM-RS) 316 for the PUSCH may be signaled, for example, in the center of the first slot 304 or the second slot 306, or in the center or fourth symbol of each slot 308. An acknowledgement (ACK) or negative acknowledgement (NACK) 318 may be communicated on one or more symbols 310. A last symbol 312 of the uplink subframe 302, e.g., a subframe that can be allocated, scheduled, or used for a PUSCH, may be used for a sounding reference signal (SRS) 320. A symbol, e.g., the last symbol in a subframe, may be used for SRS transmission, e.g., by the same WTRU that can transmit a PUSCH in the subframe or by a different WTRU. If an uplink subframe is potentially used for SRS transmission and the PRB allocated for PUSCH transmission can be used for SRS transmission, the WTRU may not send a PUSCH in the last symbol. The first slot 304 may be designated as slot 0, and the second slot 306 may be designated as slot 1. For example, if PUSCH frequency hopping is configured or activated, different frequency or PRB locations may be used for PUSCH transmission in the first slot 304 and the second slot 306.

[0076] Additionally, one or more subframes may be configured or used at least partially for the uplink and at least partially for the downlink. A special subframe may be, or may be used to represent, a subframe that may be configured or used at least partially for the uplink and at least partially for the downlink. A special subframe may be, or may be used to represent, a subframe that may be configured or used at least sometimes for the uplink and at least sometimes for the downlink. A special subframe may be configured or used, for example, within a frame or radio frame. One or more special subframes may apply to time division duplex (TDD) operation, i.e., operation in which a frequency or frequency band may be time-shared between uplink and downlink transmissions. For example, the number of special subframes within a radio frame, or, for example, the time locations for the special subframes within a radio frame, may be determined based on a UL-DL subframe configuration, such as a TDD UL-DL subframe configuration.

[0077] [Table 1]

[0078] Table 1 shows an example of a TDD UL-DL subframe configuration within a radio frame, where D may represent a downlink subframe that may include downlink symbols, U may represent an uplink subframe that may include uplink symbols, and S may represent a special subframe. The special subframe may include at least one of a downlink symbol, an uplink symbol, and a guard time or guard symbol. For example, the special subframe may include at least one downlink symbol, at least one uplink symbol, and at least one symbol (or other time) as a guard period between the downlink and uplink symbols. Within the special subframe, one or more downlink symbols may be referred to as a downlink pilot time slot (DwPTS), and one or more uplink symbols may be referred to as an uplink pilot time slot (UpPTS). Furthermore, one or more symbols (or time) not used for the DwPTS or UpPTS may be referred to as a gap period or guard period (GP).

[0079] The GP in a special subframe may be positioned midway between the DwPTS and the UpPTS. The number of symbols or time periods that may be used for the DwPTS, UpPTS, and GP for a special subframe may be determined based on the special subframe configuration. Table 2 shows an example of a special subframe configuration and the number of symbols that may be used for the DwPTS, UpPTS, and GP.

[0080] [Table 2]

[0081] 4 is an example of a special subframe 408 configuration having a DwPTS symbol 414, a GP symbol 416, and an UpPTS symbol 418. Within the special subframe 408, special subframe configurations 0-8, such as those from Table 2, may be configured or utilized. For example, three downlink symbols 404 may be used for the DwPTS, one uplink symbol 412 may be used for the UpPTS 406, and the remainder of the symbols 410 in the subframe may be used as GP in special subframe configuration #0.

[0082] The WTRU may assume that no downlink signal is present in the GP symbols 416. Within symbols that may be used for or intended for use for GP, the WTRU may not attempt to decode signals or transmissions, receive signals or transmissions, measure signals or transmissions, estimate signals or transmissions, transmit signals or other transmissions, etc.

[0083] One or more downlink (DL) signals, channels, data channels, or control channels may be transmitted or received in a DL symbol or DwPTS symbol 414. One or more DL signals or channels may include one or more reference signals, cell-specific reference signals (CRS), DL DM-RS, etc. One or more uplink (UL) signals, channels, data channels, or control channels may be transmitted or received in a UL symbol or UpPTS symbol 418. One or more UL signals or channels may include one or more reference signals, such as a UL DM-RS or SRS. A pilot signal may also be a reference signal.

[0084] A subframe that may be configured or used as a multicast broadcast single frequency network (MBSFN) subframe for at least some WTRUs may be configured or used as a special subframe for at least some, e.g., some other, WTRUs.

[0085] The WTRU may determine the power or energy for transmission based on one or more of path loss, resources allocated for transmission in time or frequency, desired received power, power control commands, static parameters, semi-static parameters, etc. The static or semi-static parameters may be provided by the base station or other network resources.

[0086] The parameters, power control formulas, or power control procedures may be established based on LTE or Advanced Long Term Evolution (LTE-A) network specifications. The power or energy for each of the set of transmissions may be determined prior to the actual transmission, and one or more of the transmit powers may be adjusted or scaled prior to the transmission. For example, if the transmission, or simultaneous transmission of the set of transmissions, would cause the WTRU to exceed a maximum power limit, the transmit power may be adjusted or scaled.

[0087] The WTRU may calculate the channel power without consideration of, or substantially independent of, a maximum power or maximum energy constraint. For example, the WTRU may adjust the channel power or calculated channel power such that the sum of the powers of the set of channels on which the WTRU can transmit or intends to transmit within a subframe does not exceed the maximum power. For channels whose power has been adjusted, the adjusted power may be used when the WTRU transmits the channel. For other channels, the calculated power may be used when the WTRU transmits the channel.

[0088] P CMAXThe maximum allowed transmit power / energy or configured maximum output power, such as, may vary depending on at least one of the power class of the WTRU, a power limit that may be signaled by the base station, or an allowable power reduction by the WTRU. The power reduction that may be allowed by the WTRU may be based on, for example, the signal to be transmitted by the WTRU to avoid exceeding out-of-band emission requirements or allowable values ​​or levels.

[0089] If the WTRU has multiple serving cells, the WTRU may configure a maximum allowed transmit power or configured maximum output power, P CMAX,c It can have:

[0090] The WTRU may determine the power for channels, e.g., UL channels, on which it can transmit, or for channels, e.g., a UL channel set for transmission, in a subframe. The WTRU may determine the following: (i) whether the total power for channels for a serving cell, e.g., to be transmitted by the WTRU in a subframe, is greater than P CMAX,c or (ii) the sum of the power for channels across some, all, or substantially all serving cells on which the WTRU may transmit, for example, completely or at least partially in a subframe, does not exceed P CMAX The power for the channel can be determined such that at least one of the following is satisfied:

[0091] If the WTRU determines that it may exceed the maximum power within a subframe or TTI, etc., the WTRU may adjust the power of one or more channels. The adjustment may be according to the relative priority of the logical or physical channels.

[0092] When a WTRU has serving cells that belong to different eNodeBs or schedulers, there may be constraints on power allocation. The constraints may be on the power allocation between the eNodeBs or schedulers. A transmission by the WTRU is performed by P CMAX Each eNodeB may have a minimum guaranteed power (MGP), which may be a percentage of . For example, when transmitting in the same, at least partially overlapping, or substantially overlapping subframes, the WTRU may take into account the MGP per eNodeB, e.g., in addition to the channel priority, when determining which channel power to adjust.

[0093] PH may be calculated, determined, or reported by the WTRU. PH for serving cell c (PHc) may be calculated as the difference between the WTRU's calculated power and the WTRU maximum power. The WTRU maximum power is P CMAX,c The computed power of the WTRU, such as Pcomputed_unconstrained,c, may be the configured maximum output power of the WTRU, such as Pcomputed_unconstrained,c. The calculated power of the WTRU, such as Pcomputed_unconstrained,c, may be the power calculated without or prior to adjusting or accounting for one or more constraints. For example, a constraint may be imposed on the transmit power by the WTRU's maximum power or by power allocation to higher priority channels.

[0094] PH can be expressed by equation (5) for serving cell or component carrier (CC) c in TTI or subframe i.

[0095] PHc(i)=P CMAX,c (i)-Pcomputed_unconstrained,c(i) Equation (5) For example, the PH for a TTI, a subframe, an LTE / LTE-A TTI, or an LTE / LTE-A subframe, where there may be a PUSCH with no PUCCH transmission or PUCCH format transmission, can be expressed as follows:

[0096] PH type1,c (i)=P CMAX,c (i)-{10log 10 (M PUSCH,c (i))+P O_PUSCH,c (j)+α c (j)·PL c +Δ TF,c (i)+f c (i)} Equation (6) M PUSCH,c (i) may be the bandwidth of the PUSCH resource allocation, which may be expressed as the number of resource blocks (RBs) available for TTI or subframe i and serving cell c. P O_PUSCH,c (j) is the component P that can be provided by higher layers for j=0 and 1 for serving cell c. O_NOMINAL_PUSCH,c (j) and the component P that can be provided by the upper layer for j = 0 and 1. O_UE_PUSCH,c (j). For PUSCH (re)transmissions corresponding to semi-persistent grants, j may be 0, for PUSCH (re)transmissions corresponding to dynamically scheduled grants, j may be 1, and for PUSCH (re)transmissions corresponding to random access response grants, j may be 2. For j=2, P O_NOMINAL_PUSCH,c The value of (j) may be determined based on the result of the random access procedure, and P O_UE_PUSCH,c (j) can be 0. α c (j) may be a parameter provided by a higher layer or may be a fixed value. c Δ may be a downlink path loss estimate that may be calculated or determined at the WTRU for serving cell c. TF,c (i) may be a parameter calculated by the WTRU based on one or more of the following parameters provided by higher layers: the number of code blocks, the size of each code block, the number of channel quality indicator (CQI) or precoding matrix indicator (PMI) bits to be transmitted, and the number of resource elements. c(i) may be a power control accumulation term, which may be, for example, an accumulation of transmit power control (TPC) commands for the PUSCH on CCc.

[0097] The PHR may be triggered or transmitted periodically, for example, based on a period or periodicity. The periodicity or period may be configured. The PHR may be event-triggered or transmitted based on the occurrence of an event. A triggering event for the PHR may comprise, for example, a change in path loss to the serving cell. A triggering event for the PHR may also comprise a change in power backoff, for example, which may be due to power management for the serving cell. A triggering event for the PHR may also comprise the expiration of a timer (e.g., a periodic timer). A change, for example, that may trigger the PHR, may include passing or progressing above a threshold. A triggering event for the PHR may also comprise the activation of a media access control (SCell) of the WTRU, such as a secondary cell (SCell) of the WTRU's MAC entity with a configured UL. A serving cell change may also be a triggering event. In the examples and embodiments described herein, the WTRU and MAC entity may be used interchangeably.

[0098] Furthermore, the triggering event may be conditioned on the expiration of a timer, such as a prohibition timer that may be used to limit the frequency of PH report transmissions. The triggering event may be conditioned on the availability of UL resources for the transmission of the PHR. The WTRU may transmit the PHR when at least one triggering event may occur. The WTRU may transmit the PHR when it may have an UL grant or allocation, such as for a new data transmission.

[0099] The transmission of requests, grants, HARQ feedback, or data may be performed according to block timing, such as TTIs or subframes. The processing time may be proportional to the transport block (TB) size.

[0100] To reduce latency, a short TTI (sTTI) may be used. Physical channels designed based on a single TTI length, e.g., 1 ms, may not be optimized for or may not work properly with a short TTI length, e.g., one or a few symbols in duration. Shortening the TTI of a control channel, such as a UL control channel, or reducing the number of symbols available for the control channel may affect the performance of the control channel.

[0101] The WTRU may make multiple transmissions that may overlap or parallel in time. In any of the examples provided herewith, overlap or parallelism in time or frequency may mean partially overlapping, substantially partially overlapping, fully overlapping, substantially fully overlapping, etc. When the transmissions use the same TTI, overlapping of transmissions may occur at the beginning or end of the transmissions. The existence of overlap may also be known in advance of both transmissions, for example, because the scheduling for the transmissions may be within ±½ TTI of each other.

[0102] If the maximum power or energy may be exceeded during an overlap of transmissions, the power or energy of one or more of the transmissions may be adjusted, such as by scaling, to avoid exceeding the maximum power during the overlap. For example, if the overlap exceeds a threshold, such as one symbol in duration, the adjustment may be applied to the entire TTI or substantially the entire TTI of the transmissions. For example, if the overlap is below a threshold, i.e., one symbol or less, the adjustment may be applied to the overlapping portion.

[0103] When transmissions use different TTIs, no overlapping of transmissions may occur at the beginning or end of a transmission. An sTTI transmission may occur, e.g., it may start or end, at any point during a longer TTI transmission. Additionally, the existence of an overlap may not be known in advance of both transmissions. For example, scheduling of an sTTI transmission may not be provided or known before the beginning of a longer TTI transmission.

[0104] Low latency transmission, reduced latency transmission, and short or sTTI transmission may be interchanged in the examples and embodiments herein. TTI and TTI length may be interchanged in the examples and embodiments herein.

[0105] Reduced latency transmissions may use a reduced TTI (rTTI) or sTTI. The rTTI or sTTI length may refer to a first TTI length that may be shorter than a second TTI length that may be a preconfigured, predetermined, typical, normal, regular, or legacy TTI length. The second TTI length may be 1 ms, 14 symbols, or 14 SC-FDMA symbols. Regular, normal, or legacy transmissions may use or be configured to use a regular TTI. Typical, normal, regular, and legacy may be interchangeable in examples and embodiments herein. Normal may also be used to represent non-short.

[0106] The sTTI length may be defined as or correspond to Ns OFDM or SC-FDMA symbols, where Ns may be less than the number of OFDM or SC-FDMA symbols for a normal TTI. For example, Ns may be less than 14. An SC-FDMA symbol may be an uplink modulation symbol, a modulation symbol, or a sidelink symbol. One or more sTTI resource units or time units may be used, configured, predefined, or determined in a time period. A resource unit may be a time unit. A time period may be one or more subframes, radio frames, slots, or symbols, and may sometimes be referred to herein as an sTTI time window. An sTTI resource may correspond to a set of one or more time units, where a time unit may be at least one of a time sample, a symbol, or a time slot. The terms sTTI resource unit, sTTI, sTTI resource, and sTTI time resource may be used interchangeably herein.

[0107] The sTTI time window may be determined based on a value that may be defined, predefined, fixed, or configurable. The value may be referred to as NsTTI. The unit of NsTTI may be ms. The sTTI time window may be determined based on an operating mode, such as TDD or FDD. The sTTI time window may be determined based on the sTTI length, for example, the sTTI time window may be a multiple of the sTTI length. The sTTI time window may be determined based on one or more system parameters, such as a cell ID or system bandwidth. The sTTI time window may be determined based on a subframe number (SFN), hyper-SFN, etc. The sTTI time window may be determined based on the TTI length for a normal subframe.

[0108] A control channel, such as a downlink control channel, may be transmitted within the first Nsym symbols in the sTTI time window. Nsym may be an integer equal to or greater than 1. One or more sTTIs or several sTTIs that may be used for gaps, such as DL-UL gaps, may be indicated by at least one of a control channel, a signal, an indication, etc. The control channel may be or include a signal or indication that may indicate a gap, e.g., one or more sTTIs or several sTTIs that may be used for a DL-UL gap. The signal or indication may be a predefined, configured, or known signal or indication. The number of sTTIs may be an integer equal to or greater than 1. For example, the number may be 0 for a direction switch that may not require or use a gap, such as a switch from UL to DL.

[0109] 5 is an example of an sTTI gap indication that may be used to indicate the configuration or use of sTTI resources for the uplink, downlink, and gap. sTTI #3 may be indicated, such as in DL control 502, as the gap sTTI 514 where a switch 510 between DL and UL may occur. A first set of sTTI resources may be sTTIs #0, #1, and #2 and may be utilized as the DL sTTI 512. A second set of sTTI resources may be sTTIs #4, #5, and #6 and may be utilized as the UL sTTI 516. In an example, the sTTI window 506 may be a subframe, and the sTTI time resource unit 508 may be a number of symbols, such as two. The sTTI time window 506 may apply across the bandwidth 504. The terms sTTI window and sTTI time window may be used interchangeably.

[0110] A DL-UL gap may be a gap between the DL and UL directions that can be used for switching, e.g., to switch a radio or RF front end from the DL direction to the UL direction. DL-UL gap, gap, DL-UL switching gap, DL to UL gap, TDD switching gap, switching gap, gap sTTI, sTTI gap, GP, TDD GP, TDD gap may be interchanged in examples and embodiments herein. Additionally, one or more sTTI time windows may be associated with a control channel or PDCCH, e.g., legacy PDCCH, that can carry one or more downlink control information (DCI).

[0111] A first set of sTTI resources that may be within or between the sTTI window may be determined or configured as a set of downlink sTTI resources or DL ​​sTTIs. A second set of sTTI resources that may be within the sTTI window, e.g., the same sTTI window, may be determined or configured as a set of uplink sTTI resources or UL sTTIs. The first set of sTTI resources and the second set of sTTI resources may not overlap or may be mutually exclusive. One or more sTTI resources may be indicated as a gap in the sTTI window. The location of the gap may determine the first set of sTTI resources and the second set of sTTI resources.

[0112] When two or more sTTI resources are indicated as a gap, the sTTI resources indicated as a gap may be contiguous in time or substantially contiguous. The number of sTTI resources used, determined, selected, or configured for the gap may be based on higher layer signaling, one or more system parameters, a dynamic indication from a control channel, an operating mode, etc. The number of sTTI resources for the gap can be determined, configured, or indicated in a cell-specific manner. Cell-specific higher layer signaling may be used to indicate the number of sTTI resources that may be used for the gap.

[0113] The number of sTTI resources for the gap can be determined, configured, or indicated in a WTRU-specific manner. A timing advance value for the WTRU may be used to configure or determine the number of sTTI resources for the gap. WTRU-specific RRC signaling may be used to configure or determine the number of sTTI resources for the gap. DCI associated with the WTRU-ID or Cell Radio Network Temporary Identifier (C-RNTI) may indicate the number of sTTI resources for the gap. The DCI may be received from the base station.

[0114] A number of sTTI resources for the downlink can be indicated. The number of sTTI resources for the downlink can determine the sTTI resource index for the gap. For example, if three sTTI resources can be determined, used, or indicated for downlink transmission, or as DL sTTIs, the fourth sTTI resource in the sTTI time window can be the starting sTTI resource for the gap. If one sTTI resource is used for the gap, the fourth sTTI resource can be used as the gap, and the fifth sTTI resource can be the first sTTI resource for uplink transmission, e.g., the UL sTTI.

[0115] One or more sTTIs may be or may be used for a switch point, such as a DL-to-UL switch point or a UL-to-DL switch point. One or more sTTIs that may be used for a switch point may be indicated or identified by at least one of a control channel, a signal, an indication, etc. For example, a control channel may be or include a signal or indication that may indicate one or more sTTIs as a switch point. The signal or indication may be a predefined, configured, or known signal or indication. A switch point may be the start of a gap, such as a gap for a DL-to-UL switch point or a UL-to-DL switch point. A switch point may also be the start of an sTTI where the direction can switch from a first direction to a second direction. A switch point may be, for example, the start of an sTTI where no gap may be needed or used between the first and second directions by the WTRU.

[0116] Additionally, a switch point may be the start of a gap, which may have a gap size of 0 or substantially 0. An indication of an sTTI gap may include an indication of the switch point, such as an sTTI for the switch point, or a gap size. The gap size may be several sTTIs, which may be consecutive sTTIs. A gap with a size of 0 may indicate or be used to indicate a switch point. Also, a gap size of 0 or no gap size may indicate or be used to indicate a switch point with no gap. Switch points and gaps may be interchangeable in examples and embodiments herein.

[0117] Multiple sTTI gaps may be indicated within the sTTI window. The first sTTI gap may be used to determine the time location of a switch from DL to UL, and the second sTTI gap may be used to determine the time location of a switch from UL to DL. The time location may be or may include one or more sTTI resources. One or more sTTI resources that may be indicated as the first gap may not be used for uplink or downlink transmission. For example, a WTRU may use one or more sTTI resources as switching time, e.g., from DL to UL, within the gap. The number of sTTI resources for a gap may be indicated, predefined, configured, semi-statically configured, or partially statically configured via higher layer signaling. One or more sTTI resources indicated as the second gap may be used for uplink or downlink transmission. The WTRU may receive or transmit signals in the one or more sTTI resources used as the second gap. The number of sTTI resources for the gap may be indicated or known, for example, may be indicated or known to be 0 or substantially 0.

[0118] 6 is an example of a multiple gap sTTI indication. The DL control 602 may comprise at least a portion of a control channel for sending control information to the WTRU. sTTI #2 or sTTI resource #2 may be denoted as the first gap 616, and sTTI #5 or sTTI resource #5 may be denoted as the second gap. The sTTI window 606 may be one or more subframes, and the sTTI time resource unit 608 may be any number of symbols, for example, spanning the bandwidth 604. For example, the sTTI window 606 may be a subframe, and the sTTI time resource unit 608 may be a number of symbols, such as two, spanning the bandwidth 604.

[0119] 6, the set of sTTI resources for downlink transmission 614 or 628 and the set of sTTI resources for uplink transmission 624 may be determined based on the location of the gap sTTI resources, such as the locations of the sTTI resources for the first gap 610 and the sTTI resources for the second gap 612. The sTTI resources designated as the first gap may be designated with a gap size as one sTTI 608. The sTTI resources designated as the second gap may be designated without a gap size or with a gap size as zero or substantially zero. As shown in FIG. 6b, for example, the sTTI resources designated as the second gap may be used as the downlink sTTI when the previous sTTI resource, i.e., the resource preceding the gap sTTI, is used as the uplink sTTI, such as 624.

[0120] An UL sTTI resource configuration using TDD GP may be utilized in the examples given herein. In one embodiment, the GP in a subframe may be used for sTTI signal transmission or reception. For example, one or more UL sTTI resources may be allocated within the GP of a special subframe.

[0121] 7 is an example of an sTTI resource configuration within a GP of a subframe 702. The subframe may be a special subframe. A WTRU may be configured, instructed, or indicated to use a first TTI operation 704, which may be normal TTI operation. The WTRU may determine to use the first TTI operation 704. The DwPTS 706, GP 708, and UpPTS 710 may be determined, for example, by the WTRU, based on a subframe configuration, such as subframe configuration #0, received from higher layer signaling, such as broadcast signaling. The subframe configuration may be a special subframe configuration. The WTRU may assume that no downlink signal may be received or no uplink signal may be transmitted within a symbol that may be used for the GP 708.

[0122] The WTRU may be configured, determined, or indicated to use an sTTI resource or transmit an sTTI. The WTRU may use one or more symbols, which may be determined as a GP based on a subframe configuration, such as the UpPTS or configuration #0, as an sTTI resource.

[0123] For example, one or more symbols that can be determined as a GP 708 based on a subframe configuration, such as subframe configuration #0, may be referred to as a GP symbol. A short or sTTI GP (sGP) 714 or 720 may be determined based on the number of GP symbols used for an sTTI resource. The sGP may be used for one or more of a guard period for sTTI operation, an sTTI transmission scheme, an sTTI operation mode, or DL-UL switching for sTTI transmission. In addition, one or more GP symbols may be used as additional symbols for the DwPTS or UpPTS. For example, seven of the GP 708 symbols may be used or determined as the UpPTS 716. The use of a portion of the GP for the UpPTS is referred to as Type 1 sTTI operation 712 in FIG. 7. An sTTI resource may be or include one or more symbols, e.g., all symbols, in an UpPTS or an UpPTS extended to include one or more GP symbols.

[0124] One or more GP symbols may be used, determined, or indicated as sTTI resources, which may be substantially separate from the DwPTS or UpPTS in the subframe 702. This configuration may be identified as Type 2 sTTI operation 718. GP symbols that may be utilized, determined, or indicated as sTTI resources may be referred to as sTTI symbols. An sTTI symbol may be used for one or more of sTTI UL, sTTI DL, or gap transmission. In the example shown in FIG. 7, seven GP symbols 708 may be used or determined as sTTI resources 722.

[0125] For example, the number of sTTI symbols or the location of the sTTI symbols within a GP, such as GP 708 of subframe 702, can be determined or predetermined based on at least one of a received subframe configuration, use of sTTI symbols for UL sTTIs, or use of sTTI symbols for DL ​​sTTIs. Table 3 shows an example of a possible sTTI symbol configuration. The sTTI symbol configuration may be based on a subframe configuration, such as a special subframe configuration. The location, such as a time location, of the sTTI symbols may be determined based on use of the sTTI resources as a DL sTTI or a UL sTTI.

[0126] [Table 3]

[0127] If sTTI symbols are used for UL sTTI, the sTTI symbols are the last N UL If an sTTI symbol is used for DL ​​sTTI, the sTTI symbol may be located in the first N GP symbols. DL When sTTI symbols are utilized for a combination of DL sTTI and UL sTTI, a first set of sTTI symbols may be used for the DL sTTI and a second set of sTTI symbols may be used for the UL sTTI.

[0128] The number of sTTI symbols in a GP, such as GP 708, can be configured via higher layer signaling. One or more parameters that may be related to sTTI operation can be signaled, and the number of sTTI symbols in a GP can be indicated from the one or more parameters. For example, the number of sTTI symbols in a GP may be determined based on a special subframe configuration, one or more parameters related to sTTI operation, or one or more system parameters such as a physical cell identity (cell ID), a virtual cell ID, a system bandwidth, and a frame structure. For example, the number of sTTI symbols in a GP may be determined based on WTRU-specific parameters such as a C-RNTI, a dynamic indication, etc.

[0129] The number of sTTI symbols may be determined based on a timing advance value used, indicated, or determined for or by the WTRU. For example, a WTRU that is indicated, determines, or uses a first timing advance value may use a first number of sTTI symbols in a GP such as GP 708. A WTRU that is indicated, determines, or is able to use a second timing advance value may use a second number of sTTI symbols in a GP such as GP 708.

[0130] One or more downlink sTTI signals, such as a short or sTTI physical downlink shared channel (sPDSCH) or a short or sTTI physical downlink control channel (sPDCCH), may be received by the WTRU in the sTTI resources. One or more uplink sTTI signals, such as a short or sTTI physical uplink control channel (sPUCCH) or a short or sTTI physical uplink shared channel (sPUSCH), may be transmitted by the WTRU in the sTTI resources. One or more reference signals associated with the DL sTTI signals or the UL sTTI signals may be transmitted or received by the WTRU in the sTTI resources.

[0131] 8 is an example of an sPUCCH resource configuration provided or used in a downlink subframe or physical resource block (PRB) 800. In FIG. 8, a first time slot 802 may correspond to an even slot number in a radio frame, e.g., a slot number in a radio frame ns mod 2=0, and a second time slot 804 may correspond to an odd-numbered slot in a radio frame, e.g., ns mod 2=1. In one example, a time slot may be 7 symbols wide across 12 subcarriers. The downlink subframe or PRB 800 may comprise one or more of a CRS 806, a PDCCH 808, a PDSCH 810, a sPDCCH / sPDSCH 812, a sGP 814, and a sPUCCH 816.

[0132] One or more DL symbols in a subframe can be used, configured, or determined as a UL sTTI resource. A DL symbol may be, for example, a symbol in a subframe that may be configured or used for DL ​​for at least one or some WTRUs. A DL symbol that does not have a cell-specific reference signal may be used or determined as a UL sTTI resource. The last N DL symbols in a subframe ULN DL symbols can be used, determined, or configured as UL sTTI resources. UL may be determined based on the number of antenna ports used for the cell-specific reference signal. In one example, if the number of CRS ports is four, e.g., antenna ports 0 / 1 / 2 / 3, then N UL may be a first number, such as 2. If the number of CRS ports may be one or two, N UL may be a second number, such as five.

[0133] N UL N may be determined based on the sTTI length used, determined, indicated, or configured for the associated downlink sTTI transmission. UL may also be determined depending on at least one of a system parameter, a subframe number, SFN, hyper-SFN, a WTRU-specific parameter, a WTRU-ID, a number of OFDM symbols that may be used for a PDCCH region such as a legacy PDCCH region, the time location of the associated downlink sTTI transmission, etc.

[0134] At least two consecutive DL symbols may be used as UL sTTI resources, and the first DL symbol or symbols may be used as sGP. Figure 8 shows an example of an sPUCCH resource configuration using the last two downlink symbols. The first symbol of the sTTI resource may be used for sGP, and the second symbol of the sTTI resource may be used for sPUCCH 816 transmission. The sPUCCH transmission may include a HARQ-ACK transmission or report and may be associated with an sPDSCH transmission. The sPDSCH transmission may be in the same subframe or a previous subframe. The sPUCCH may be utilized for one or more HARQ-ACK transmissions for one or more associated sPDSCH transmissions.

[0135] Additionally, the sPUCCH may be utilized to communicate scheduling requests for uplink resources for reduced latency transmissions.

[0136] The sPUCCH can be defined, determined, configured, or utilized to provide an indication of a particular traffic type of the data in the buffer, including reduced latency traffic, emergency traffic, very low latency traffic, short TTI traffic, very reliable traffic, etc.

[0137] The sPUCCH can be defined, determined, configured, or utilized for (e.g., for transmission of) or to communicate CSI for one or more sTTI resources configured, determined, indicated, or used. The CSI can include CQI associated with one or more sTTI resources. The CSI can include one or more preferred sTTI resources for downlink or uplink sTTI transmission. The CSI can include one or more multiple antenna transmission(s) related CSI, including, but not limited to, a precoding matrix indicator (PMI), a rank indicator (RI), a precoding type indicator (PTI), a CSI-RS index (CRI), a quasi-co-location indication (QCI), etc. The sPUCCH can be defined, determined, configured, or utilized to provide or communicate an uplink reference signal for uplink channel measurements.

[0138] One or more sPUCCH formats, types, structures, or resources may be defined, configured, determined, or used for reduced latency transmission or to improve uplink performance. sPUCCH formats, sPUCCH types, sPUCCH structures, sPUCCH resources, and resources for sPUCCH transmission may be used interchangeably consistent with embodiments and examples herein.

[0139] The sPUCCH type can be determined or identified based on the sTTI length of the sPUCCH transmission, which may be several uplink symbols, the sTTI length of the associated downlink transmission or channel, such as an sPDCCH or sPDSCH, DCI, higher layer signaling, dynamic indication, reference signal location within the sPUCCH transmission, transmit power level or maximum transmit power level, reference signal overhead or density of the sPUCCH transmission, etc. The sPUCCH type can also be determined or identified based on the number of frequency resources used for the sPUCCH transmission, which may be several PRBs, several tones, or several subcarriers. The sPUCCH type can also be determined or identified based on a set of frequency locations, for example, even-numbered subcarriers or odd-numbered subcarriers. The sPUCCH type can also be determined or identified based on the sequence type used, such as a Zadoff-Chu sequence, a Golay sequence, a Gold sequence, etc. The sPUCCH type may also be determined or identified based on the modulation scheme or set of modulation schemes used, such as binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), π / 2-BPSK, π / 4-QPSK, etc. For example, a first set of modulation schemes may be BPSK and QPSK, and a second set of modulation schemes may be π / 2-BPSK and π / 4-QPSK.

[0140] Furthermore, the sPUCCH type can be determined or identified based on a scheme used to transmit a HARQ-ACK transmission or report, such as a subcarrier-based scheme, a cyclic shift-based scheme, or a frequency hopping scheme. In the HARQ-ACK scheme, a set of subcarriers can be determined for the HARQ-ACK transmission or report. For example, a first set of subcarriers may be used or selected for an ACK transmission or report, and a second set of subcarriers may be used or selected for a NACK transmission or report. In another HARQ-ACK scheme, a set of cyclic shifts of a sequence may be used for the HARQ-ACK transmission. For example, a first cyclic shift index may be used or selected for an ACK transmission or report, and a second cyclic shift index may be used or selected for a NACK transmission or report. In another HARQ-ACK scheme, a set of frequency hopping patterns may be used for the HARQ-ACK transmission. For example, a first frequency hopping pattern may be used or selected for ACK transmission or for reporting ACKs, and a second frequency hopping pattern may be used or selected for NACK transmission or for reporting NACKs.

[0141] Within an sTTI time window, such as a subframe, one or more sPUCCH resources or types can be configured, defined, or utilized. One or more sPUCCH resources may be directed to one or more WTRUs. The sTTI time window can be fixed, predefined, preconfigured, or predetermined as a specific value. For example, the sTTI window may be predefined as a normal TTI length or with a length of 1 ms. The sTTI time window may also be determined based on the sTTI length or a multiple, such as an integer multiple of the sTTI length. For example, if the sTTI length is L sTTI It is called N sTTIis a positive integer used to determine the sTTI length, the sTTI window length is L sTTI ×N sTTI The sTTI time window may also be determined based on a downlink sTTI time window, higher layer signaling, RRC signaling, dynamic signaling from a downlink physical channel, etc.

[0142] The sPUCCH type may be determined based on a coverage level, which may be configured or determined. The coverage level may be configured via, but is not limited to, higher layer signaling for at least one of a downlink control channel, a downlink data channel, an uplink control channel, and an uplink data channel. The coverage level may be determined, for example, by the WTRU based on a coverage level selected or determined for a physical random access channel (PRACH) transmission. The sPUCCH type may also be determined based on a downlink measurement level. For example, a predefined or configured threshold may be used to determine the sPUCCH type. The downlink measurement may include at least one of a reference signal received power (RSRP), a reference signal received quality (RSRQ), and a CQI.

[0143] The sPUCCH type may be determined based on the sTTI length of the associated DL channel. The sTTI length used for the sPDCCH or sPDSCH may determine the sPUCCH type. The sPUCCH type may be determined based on higher layer signaling. The sPUCCH type may be indicated implicitly or explicitly by higher layer signaling. The sPUCCH type may be determined based on a dynamic indication. The DCI associated with the sPUCCH transmission may indicate or determine the sPUCCH type for the sPUCCH transmission.

[0144] The sPUCCH type may be determined based on the number of sPDSCHs that can be associated with an sPUCCH transmission. For example, if a single sPDSCH transmission can be associated with an sPUCCH transmission, e.g., for a HARQ-ACK transmission or a report, a first sPUCCH type or format may be used. When two or more sPDSCH transmissions can be associated with an sPUCCH transmission, e.g., for a HARQ-ACK transmission or a report, a second sPUCCH type or format may be used.

[0145] The sPUCCH type may be determined based on the number of HARQ-ACK bits for one or more associated sPDSCHs. For example, a first sPUCCH type or format may be used when the number of HARQ-ACK bits is less than or equal to a threshold, which may be defined, predefined, or configurable. A second sPUCCH type or format may be used when the number of HARQ-ACK bits is greater than a threshold, which may be defined, predefined, or configurable. One or more thresholds may be used in conjunction with one or more sPUCCH types or formats.

[0146] The sPUCCH may be transmitted with repetition, i.e., repeatedly, in one or more sTTI resources. Higher layer signals may indicate the number of repetitions for the sPUCCH transmission. For example, the sPUCCH type and the number of repetitions, i.e., the number of repetitions, of the sPUCCH transmission may be configured via higher layer signaling, such as broadcast or RRC signaling. The number of sPUCCH repetitions may be predefined, configured, dynamically indicated from the associated DCI, or determined based on the sTTI resources used for the sPUCCH transmission.

[0147] The number of repetitions for an sPUCCH transmission may also be determined based on the number of repetitions used for the associated sPDSCH or sPDCCH transmission. The modulation and coding scheme (MCS) level of the associated sPDSCH transmission may determine the number of sPUCCH repetitions. For example, if a higher MCS level is used for the associated sPDSCH transmission, the number of repetitions for the sPUCCH may be smaller. If a lower MCS level is used for the associated sPDSCH transmission, a greater number of repetitions for the sPUCCH may be used. The number of repetitions for the sPUCCH transmission may be determined based on the short or sTTI control channel element (sCCE) aggregation level of the sPDCCH that may be used for the associated sPDCCH. For example, if a higher CCE aggregation level is used for the associated sPDCCH, the number of repetitions for the sPUCCH may be greater. If a lower sCCE aggregation level is used for the associated sPDCCH, a lower number of repetitions for the sPUCCH may be used. In the embodiments and examples described herein, the sPUCCH may be replaced with the sPUSCH, and vice versa.

[0148] An sPUSCH can be defined, determined, configured, or used for uplink data transmission. One or more sPUSCH types, structures, or resources can be defined, configured, determined, or used, for example, for reduced latency transmission or improved uplink performance. sPUSCH types, sPUSCH structures, and sPUSCH resources may be interchangeable in the examples and embodiments herein.

[0149] The sPUSCH type may be determined based on the sTTI length of the sPUSCH transmission, which may be several uplink symbols. The sPUSCH type may be determined based on the sTTI length of the associated downlink control channel for the uplink grant, the sTTI length of the associated sPDCCH carrying the uplink grant, the reference signal location within the sPUSCH transmission, the reference signal overhead or density of the sPUSCH transmission within a PRB, a set of frequency locations such as a PUSCH transmission within a PRB or a subset of subcarriers that may be used for the sPUSCH transmission, a modulation scheme, etc. The subset of subcarriers may be, for example, even-numbered subcarriers or odd-numbered subcarriers.

[0150] Within an sTTI time window, such as a subframe, one or more sPUSCH resources or types may be configured, defined, or used, and one or more sPUSCH resources may be directed to one or more WTRUs.

[0151] sPUSCH link adaptation may be provided or used. The sPUSCH type or the number of repetitions for the sPUSCH transmission may be determined based on the coverage level. The coverage level may be configured or determined. The coverage level may be configured via higher layer signaling for at least one of a downlink control channel, a downlink data channel, an uplink control channel, an uplink data channel, etc. The coverage level may also be determined based on a coverage level selected or determined for the PRACH transmission, such as by the WTRU.

[0152] The sPUSCH type or the number of repetitions for an sPUSCH transmission may also be determined based on a downlink measurement level. For example, a predefined or configured threshold may be used to determine the sPUSCH type or the number of repetitions for an sPUSCH transmission. The downlink measurement may include at least one of RSRP, RSRQ, CQI, etc. The sPUSCH type or the number of repetitions for an sPUSCH transmission may be determined based on the sTTI length of the associated downlink channel.

[0153] The sTTI length used for the sPDCCH or sPDSCH may determine the sPUSCH type or the number of repetitions for the sPUSCH transmission. The sPUSCH type or the number of repetitions for the sPUSCH transmission may be determined based on higher layer signaling, dynamic indication, DCI associated with the sPUSCH transmission, etc. The sPUSCH type or the number of repetitions for the sPUSCH transmission may be implicitly or explicitly indicated from higher layer signaling. The DCI associated with the sPUSCH transmission may indicate the sPUSCH type or the number of repetitions for the sPUSCH transmission. The transport block size (TBS), which may be indicated in the associated DCI for sPUSCH scheduling, may determine or may be used to determine the sPUSCH type or the number of repetitions for the sPUSCH transmission. The MCS level, which may be indicated in the associated DCI for sPUSCH scheduling, may determine or may be used to determine the sPUSCH type or the number of repetitions for the sPUSCH transmission. The sCCE aggregation level of the sPDCCH used for uplink grants of sPUSCH can determine or may be used to determine, for example, the sPUSCH type for the allowed sPUSCH transmissions or the number of repetitions for the sPUSCH transmissions.

[0154] FIG. 9 is an example of a two-symbol short or sTTI PUCCH (sPUCCH) 900, FIG. 10 is an example of a three-symbol sPUCCH 1000, and FIG. 11 is an example of a four-symbol sPUCCH 1100. The sPUCCH 1000 or 1100 can utilize a cover code for the r1 sequence when interference mitigation is desired. The sPUCCH can use several symbols for transmission of one or two bits of information, such as a UL reference signal r2 902 and HARQ feedback 912. The HARQ feedback 912 may be modulated using BPSK, QPSK, etc., and may be combined with the sequence r1 916 by a multiplication operation 914. The output of the multiplication operation 914 may be processed by an inverse fast Fourier transform (IFFT) 918 and may be mapped to resources on symbols 920.

[0155] The UL reference signal r2 902 may be multiplied by 1 at 904. The output of the multiplication operation 904 may be processed by an Inverse Fast Fourier Transform (IFFT) 906 and mapped to resources on symbols 920. Alternatively, the multiplication at 904 may be skipped and the UL reference signal r2 902 may proceed directly to the IFFT 906. The sequences r1 916 and r2 902 may be sequences or pairs of sequences with desirable correlation properties, such as Zadoff-Chu (ZC) or Golay. For a ZC-based configuration, the sequences r1 916 and r2 902 may be based on different root values ​​(or indices) or different cyclic shifts of the same root value (or index). The sPUCCH 900, 1000, or 1100 may be mapped across m PRBs. r i The sequence length for the sequence may be set to cover 12m subcarriers.

[0156] The variables n 910 and n±i, e.g., n±1 922, may indicate that the relative position of the mapping of the UL reference signal r2 902 in time may be before or after the symbol carrying the HARQ feedback 912. The location of the UL reference signal may be placed or moved between the symbols carrying the HARQ feedback 912, for example, to reduce channel estimation errors for other or more distant symbols.

[0157] For the sPUCCH 1000, several symbols may be utilized for transmission of a UL reference signal r2 1002 and one or two bits of information, such as HARQ feedback 1012. The HARQ feedback 1012 may be modulated using BPSK, QPSK, etc., over two symbols. The HARQ feedback 1012 may be combined with a sequence r11 014 by a multiplication operation 1016. The output of the multiplication operation 1016 may be processed by an IFFT 1018 and may be mapped to resources on the symbols 1010 in n±1 1020. The HARQ feedback 1012 may also be combined with a sequence r11 014 by a multiplication operation 1013. The output of the multiplication operation 1013 may be processed by an IFFT 1022 and may be mapped to resources on the symbols 1010 in n±2 1024. The UL reference signal r2 1002 may be multiplied by 1 at 1004, and the output of the multiplication operation 1004 may be processed by an IFFT 1006 and mapped to resources on symbols 1010 at n 1008. Alternatively, the multiplication at 1004 may be skipped.

[0158] For the sPUCCH 1100, several symbols may be utilized for transmission of 1 or 2 bits of information, such as a UL reference signal r2 1102 and HARQ feedback 1112. The HARQ feedback 1112 may be modulated using BPSK, QPSK, etc., over three symbols. The HARQ feedback 1112 may be combined with a sequence r11114 by a multiplication operation 1116. The output of the multiplication operation 1116 may be processed by an IFFT 1118 and may be mapped to resources on the symbols 1108 at n±1 1120. The HARQ feedback 1112 may also be combined with a sequence r11114 by a multiplication operation 1122. The output of the multiplication operation 1122 may be processed by an IFFT 1124 and may be mapped to resources on the symbols 1108 at n±2 1126.

[0159] The HARQ feedback 1112 may also be combined with sequence r 11114 by multiplication operation 1111. The output of multiplication operation 1111 may be processed by IFFT 1128 and may be mapped to resources on symbols 1108 at n±3 1130. The UL reference signal r 1102 may be multiplied by 1 at 1104. The output of multiplication operation 1104 may be processed by IFFT 1106 and may be mapped to resources on symbols 1108 at n 1110. Alternatively, the multiplication at 1104 may be skipped.

[0160] Table 4 shows an example of an sPUCCH configuration for a slot with 7 symbols. The (N)ACK index may indicate the corresponding (s)PDSCH payload. The sPUCCH combination may represent a set of symbols for data, e.g., ACK / NACK or the use of one or more UL reference signals. The set of symbols may be an sPUCCH resource.

[0161] [Table 4]

[0162] 12 is an example of a signal structure for a one-symbol sPUCCH 1200. For the sPUCCH 1200, no UL reference signal may be transmitted. HARQ feedback information 1202, comprising one or two bits, is i 1206. i The sequence length for the sequence may be selected by sequence selection component 1204. The output of sequence selection component 1204 may be processed in IFFT 1208 and may be mapped to resources on symbols 1210 at symbol n 1212. For a ZC-based configuration, HARQ feedback information 1202 may be communicated by choosing different roots of the ZC sequence or based on different cyclic shifts of the same root value.

[0163] The sPUCCH 1200 may be mapped across m PRBs. i The sequence length for the sequence may be configured to cover 12m subcarriers. A multi-symbol sPUCCH may rely on the transmission of one symbol as multiple instantiations. The frequency mapping of each symbol may be on the same PRB or may hop to different PRBs.

[0164] FIG. 13 is an example of a signal structure for a multi-symbol sPUCCH without a UL reference signal 1300 transmission, where PRB i and PRB j may be different. The HARQ feedback information 1302 comprising 1 or 2 bits is i 1304. i The sequence length for the sequence may be selected by sequence selection component 1301. The output of sequence selection component 1301 is the resource (n, PRB i ) 1310 may be processed in IFFT 1306, which is mapped to resources on symbols 1308. The output of sequence selection component 1301 may also be mapped to resources (n±1, PRB j) 1314 may be processed in IFFT 1312 mapped to resources on symbols 1308 .

[0165] Figure 14 shows an example of a signal structure for a one-symbol sPUCCH with repetition over several RBs 1400. HARQ feedback information 1402 with 1 or 2 bits is i 1404. i The sequence length for the sequence may be selected by sequence selection component 1401. The output of sequence selection component 1401 may be processed in IFFT 1406 in resource n 1410, mapped to m RBs by repetition 1408. For this configuration, a sequence having a length, such as length 12, may be selected and mapped to m RBs on that symbol. i may be repeated across the used RBs.

[0166] When there are multiple symbols available for transmission, the selected sequence may be repeated across m RBs on the symbols allocated for data transmission. Table 5 shows an example where sequence r may be repeated across RBs k and k+1 in symbols n and n+3.

[0167] [Table 5]

[0168] One or more sPUCCH combination configurations that may be available or that may be used can be fixed, configured, signaled, signaled via higher layer signaling, dynamically signaled, indicated in physical layer signaling such as in a DL grant or DCI, etc. For example, an sPUCCH combination to be used for HARQ-ACK feedback related to a PDSCH can be indicated in a DCI granting or allocating the PDSCH.

[0169] The sPUCCH combination configuration may be fixed for all configured subframes or may vary according to subframe number. The sPUCCH combination configuration may be based on the frequency location of the PRBs that may be used for sPUCCH transmission or the subframe number. In FDD, the sPUCCH combination configuration for subframes 0 and 5 may be different from that of other subframes.

[0170] A WTRU or group of WTRUs may be able to use or be configured to use the same i-th location for the sPUCCH substantially most of the time for a fixed or semi-static sPUCCH combining configuration, which may be dynamically signaled through reuse of an existing DCI field or a new 2-3 bit DCI field.

[0171] The WTRU may be capable of or configured to use a subset of sequences for the sPUCCH that may be defined or used for the regular PUCCH. The WTRU may also be capable of or configured to use a set for sPUCCH operation that may not be the same as or overlap with the set that may be used for the regular PUCCH.

[0172] One or more uplink short or sTTI transmissions may have a first sTTI length, and one or more downlink transmissions may have a second sTTI length, where the first sTTI length and the second sTTI length may be the same or different. One or more uplink short or sTTI channels, such as sPUCCH or sPUSCH, may have the same or different sTTI lengths. One or more downlink sTTI channels, such as sPDSCH or sPDCCH, may have the same or different sTTI lengths. The terms short channel and sTTI channel may be used interchangeably.

[0173] 15 is an example of short, or sTTI, PDCCH (sPUSCH) scheduling in a communication 1500 having one or more associated short, or sTTI, PDCCH (sPDCCH) regions for an sPDCCH transmission 1502. One or more sPDCCH candidates may be configured, transmitted, monitored, or decoded by a WTRU in an sPDCCH region or transmission. The WTRU may receive a scheduling grant for an sPUSCH transmission 1510 in one or more associated sPDCCH regions or transmissions. sPUSCH resource #1 for the sPUSCH transmission 1510 may be associated with two sPDCCH regions or transmissions, such as sPDCCH #1 in subframe n and sPDCCH #2 in subframe n+k. Correspondingly, sPUSCH resource #2 for sPUSCH transmission 1510 may be associated with two sPDCCH regions or transmissions, such as sPDCCH #3 in subframe n+k and sPDCCH #4 in subframe n+k+1.

[0174] The sTTI length for the sPUSCH transmission 1510 may be configured to be longer than the sTTI length for the associated sPDSCH. The WTRU may also receive, decode, attempt to decode, or monitor DCI for scheduling grants for the sPUSCH transmission 1510. The sPDCCH candidates may carry DCI for uplink or downlink scheduling.

[0175] 16 shows an example of an association between an sPUSCH and at least one sPDCCH 1602 for HARQ-ACK reception when the UL sTTI length and the DL sTTI length are different. In communication 1600, one or more sPDCCH regions can be associated with an sPUSCH region for sPUSCH scheduling or HARQ-ACK transmission or reporting. For example, an sPUSCH transmission in communication 1600 within an sPUSCH region, i.e., transmission #0 in subframe n, can be associated with sPDCCH regions, i.e., transmissions #0, #1, #2, and #3 in subframe n+2. In addition, the sTTI length of the sPDCCH may be longer than that of the sPUSCH.

[0176] For the sPUSCH transmission 1610, the WTRU may receive a HARQ-ACK, such as on a Physical Hybrid ARQ Indicator Channel (PHICH) associated with the sPUSCH transmission. If the WTRU receives a negative HARQ-ACK, i.e., a NACK, the WTRU may transmit the same transport block at a default or predetermined location. The WTRU may receive an indication of a retransmission, e.g., an uplink grant with a new data indicator. For this configuration, the new data indicator bit in the uplink grant may not be toggled, and the WTRU may retransmit the transport block in the scheduled uplink resources associated with the uplink grant; if the new data indicator bit is toggled, the new data indicator bit is changed from 0 to 1 or from 1 to 0. Otherwise, the new data indicator bit is not toggled.

[0177] The number of sPUSCH regions or transmissions, sPUSCH sTTI resources, or sPDCCH regions associated with an sPUSCH sTTI may be determined based on the sPDCCH sTTI length and the sPUSCH sTTI length. As an example, Nsp sPDCCH regions may be associated with an sPUSCH region. Nsp may be determined based on the sPUSCH sTTI length. If one or more sPUSCH regions have different sTTI lengths, Nsp may be different for one or more sPUSCH regions. For some configurations, an sPUSCH region with a shorter sTTI length may have fewer associated sPDCCH regions, and an sPUSCH region with a longer sTTI length may have a greater number of associated sPDCCH regions.

[0178] Nsp may be determined based on the sTTI length of the sPDCCH or sPDCCH region, or the time location of the sPDCCH or sPUSCH region. For example, the first sPUSCH region in an sTTI time window may have a larger Nsp than the subsequent or last sPUSCH region in the same sTTI time window. Nsp may be determined based on the SFN or hyper-SFN for the sPUSCH region, the sPUSCH region index within the sTTI time window, the sPUCCH type, the sPUSCH type, etc.

[0179] The WTRU may monitor, attempt to decode, or receive UL DCI or DL ​​HARQ-ACK for sPUSCH transmission in the sPDCCH region. The WTRU may monitor a subset of the Nsp sPDCCH regions for UL DCI, UL grant, uplink grant, sPUSCH scheduling DCI, DCI for UL grant, etc. The UL DCI may include scheduling information related to the sPUSCH transmission. The UL DCI or the CRC of the UL DCI may be scrambled using WTRU-specific parameters such as C-RNTI, WTRU-ID, etc. The UL DCI size may be the same as the DL DCI. The subset of the Nsp sPDCCH regions may be configured as a single sPDCCH region. The WTRU may monitor, receive, or attempt to decode one sPDCCH region exclusively for UL DCI within the Nsp sPDCCH regions. For example, a subset of Nsp sPDCCH regions for UL DCI for a WTRU may be determined based on one or more WTRU-specific parameters.

[0180] The sPDCCH region within the Nsp sPDCCH regions may be determined by the WTRU as a function of a modulo operation of Nsp, the WTRU-ID, the C-RNTI, etc. By distributing the sPDCCH regions for UL DCI in a WTRU-specific manner, the sPDCCH blocking probability for UL DCI may be reduced. Additionally, when more than one sPDCCH region is included, e.g., by or for the WTRU, in the subset of Nsp sPDCCH regions that may be used for UL DCI, the number of sPDCCH candidates that can be monitored by the WTRU may be divided among the subset of sPDCCH regions.

[0181] An sPDCCH region within the Nsp sPDCCH regions associated with an sPUSCH resource may have an sPDCCH region index. The index may be a function of the time or frequency location of the sPDCCH region. The index may be a function of its position in time or frequency within the Nsp sPDCCH regions. In addition, for example, a subset of the Nsp sPDCCH regions for UL DCI for one or more WTRUs may be determined based on the time (or frequency) location or sPDCCH region index. For example, a first sPDCCH region among the Nsp sPDCCH regions may be determined as the subset of the Nsp sPDCCH regions that may be used for UL DCI. The first sPDCCH region may be the earliest region in time, the region with the lowest frequency, the region with the highest frequency, the region with the smallest index, etc.

[0182] The subset of Nsp sPDCCH regions may be determined based on an sPDCCH region index and / or system parameters, where the system parameters may include at least one of a physical cell ID (PCID), a slot number, a subframe number, and a radio frame number. For example, a modulo operation using the sPDCCH region index and the PCID may be used. The subset of Nsp sPDCCH regions may also be determined based on sPDCCH regions that may be used, monitored, determined, or configured for DL ​​DCI for sPDSCH transmission. For example, the WTRU is configured or determined to monitor a subset of sPDCCH regions for DL ​​DCI, which may be the same subset for UL DCI.

[0183] The WTRU may monitor DL ​​DCI and UL DCI within the same set of sPDCCH regions, transmissions, or candidates. The DL DCI may be the DCI used for fallback transmission and may be determined based on a configured transmission scheme or mode. In the configuration, a subset of Nsp sPDCCH regions may be determined based on the presence of a pre-defined signal. For example, the pre-defined signal may be transmitted in a first sPDCCH region, and the pre-defined signal may indicate the subset of Nsp sPDCCH regions for UL DCI.

[0184] sPDCCH candidates for UL DCI may be arranged in Nsp sPDCCH regions. At least one of the sPDCCH candidates arranged in the Nsp sPDCCH regions may be used for UL DCI. For example, when Nsp = 1, Ntot sPDCCH candidates can be used, configured, or monitored in an sPDCCH region. For example, when Nsp > 1, the Ntot sPDCCH candidates may be divided among the Nsp sPDCCH regions. The Ntot sPDCCH candidates may be evenly distributed across the Nsp sPDCCH regions. For example, if Ntot = 16 and Nsp = 4, each sPDCCH region may include four sPDCCH candidates for UL grants.

[0185] A subset of sCCE aggregation levels (ALs) may be monitored within an sPDCCH region. For example, if sCCE aggregation levels {1,2,4,8} are used and Nsp=4, sPDCCH candidates with sCCE AL{1} may be monitored within a first sPDCCH region, sPDCCH candidates with sCCE AL{2} may be monitored within a second sPDCCH region, and so on. The search space for each sPDCCH region, e.g., the starting sCCE number per sCCE aggregation level, may be determined based on the sPDCCH region index, the WTRU-ID, a predefined value, a hashing parameter, etc.

[0186] An sPDCCH candidate may be transmitted via one or more sPDCCH regions within the Nsp sPDCCH regions. In addition, one or more sPDCCH candidates in the search space may be repeatedly transmitted across the Nsp sPDCCH regions. sCCEs for the sPDCCH candidate may also be distributed across the Nsp sPDCCH regions. The number of repetitions of the sPDCCH candidate within the Nsp sPDCCH regions may be determined based on the search space type, the WTRU-specific search space, the common search space, the number of sPDCCH regions, Nsp, the WTRU coverage level, the configured coverage level, the determined coverage level, or a numerical value configured by higher layers. sCCEs may be numbered from 0 to Ncce-1 by using all configured sCCEs in the Nsp sPDCCH regions. Furthermore, a set of sCCEs may be selected, determined, configured, or used based on the search space determination.

[0187] 17 illustrates an example of an association of an sPUCCH 1710 for HARQ-ACK transmission with at least one short or sTTI physical downlink shared data channel (sPDSCH) when the UL sTTI length and DL sTTI length are different. In communication 1700, the sTTI length for sPDSCH transmission 1702 may be shorter than the sTTI lengths for sPUCCH regions #0-#4. For example, sPDSCH regions #0, #1, #2, and #3 in subframe n+1 may be associated with sPUCCH region #0. In other words, in communication 1700, the sTTI length for sPUCCH region #0 is longer than the sTTI length for sPDSCH transmission 1702.

[0188] One or more sPDSCH regions may be associated with an sPUCCH region, resource, or transmission for a HARQ-ACK transmission. For example, in communication 1700, the WTRU may receive sPDSCH in the first sPDSCH region #1 and in the second sPDSCH region #3, while HARQ-ACK transmissions or reports for the first sPDSCH region #1 and the second sPDSCH region #3 may be associated with sPUCCH region #0.

[0189] In communication 1700, sPUCCH#0 may be associated with one or more sPDSCHs and may include one or more sPUCCH resources. After receiving the sPDSCH, the WTRU may send a HARQ-ACK in the uplink using the sPUCCH resources in the associated sPUCCH region.

[0190] Within an sPUCCH region, one or more sPUCCH resources can be defined, configured, determined, or indicated as at least one of a PRB index, an UL symbol number, a cyclic shift index, a tone, a subcarrier index, etc. One or more DL sTTI transmissions, e.g., sPDCCH or sPDSCH, may be associated with the sPUCCH region and sPUCCH resources based on a starting DL symbol, an OFDM symbol number of the DL sTTI transmission, a DL sTTI resource index, an sTTI number or index within the sTTI time window, etc. One or more DL sTTI transmissions within an sTTI time window may also have different starting DL symbol numbers or indexes. For example, the first DL sTTI transmission may start at DL symbol #2, and the second DL sTTI transmission may start at DL symbol #4. The one or more DL sTTI transmissions within an sTTI time window may be indexed in ascending order.

[0191] A set of sPUCCH resources can be configured, reserved, used, determined, or indicated to be associated with a DL sTTI. When an sPUCCH region is associated with Ndstti downlink sTTI resources, Ndstti sets of sPUCCH resources can be configured, used, or determined within the sPUCCH region, and the set of sPUCCH resources may be determined based on the downlink sTTI time location, the starting OFDM symbol, the DL sTTI number, etc. The Nstti sets of sPUCCH resources may be non-overlapping, fully overlapping, partially overlapping, etc. within the sPUCCH region.

[0192] In one embodiment, the WTRU may receive one or more DL sTTI transmissions associated with the sPUCCH region and may transmit an sPUCCH resource as a HARQ-ACK transmission or report. The sPUCCH resource may include one or more HARQ-ACKs associated with one or more DL sTTI transmissions. When the WTRU receives two or more DL sTTI transmissions that may be associated with the sPUCCH region, a single sPUCCH resource may be transmitted. For this configuration, a single sPUCCH resource may be used to transmit a bundled HARQ-ACK transmission or report. For example, the WTRU may send a negative HARQ-ACK, i.e., NACK, for one or more DL sTTI transmissions if at least one of the DL sTTI transmissions has an error. An error may occur when the WTRU may fail to receive at least one of the DL sTTI transmissions. When all configured DL sTTI transmissions are received without error, the WTRU may send a positive HARQ-ACK, i.e., ACK.

[0193] The first sPUCCH resource may be used for a bundled HARQ-ACK transmission or report that may be associated with a first DL sTTI transmission within one or more DL sTTI transmissions to the WTRU. A single sPUCCH resource within the set of sPUCCH resources may be selected, determined, or used to indicate one or more HARQ-ACK transmissions or reports. The selection of the sPUCCH resource may indicate HARQ-ACK information. For example, if the WTRU selects or uses the first sPUCCH resource, the selection may indicate a negative HARQ-ACK for the second DL sTTI transmission. If the WTRU selects or uses the second sPUCCH resource, the selection may indicate a positive HARQ-ACK for the second DL sTTI transmission. Additionally, for the examples given herein, the modulation scheme constellation, or modulation scheme such as BPSK or QPSK, may be used to indicate a positive / negative HARQ-ACK.

[0194] Table 6 shows an example of HARQ-ACK transmission or reporting with sPUCCH resource selection and QPSK modulation when an sPDSCH among one or more sPDSCH resources associated with an sPUCCH region is scheduled to a WTRU. If a single sPDSCH is scheduled among one or more sPDSCH resources, the sPUCCH resource can be associated with the sPDSCH for HARQ-ACK transmission or reporting. If multiple codewords are transmitted, a QPSK constellation, e.g., constellations 0 (00), 1 (01), 2 (10), and 3 (11), can indicate HARQ-ACK information for two codewords. If a single codeword is used, BPSK may be used, or a subset of the QPSK constellation may be used.

[0195] [Table 6]

[0196] Tables 7 and 8 show examples of HARQ-ACK transmission or reporting with sPUCCH resource selection and QPSK modulation. The WTRU may select or determine the sPUCCH resource selection and QPSK constellation to indicate HARQ-ACK for one or more sPDSCH transmissions. If multiple sPDSCHs scheduled for the WTRU are associated with the sPUCCH, the WTRU may select or determine the sPUCCH resource within the set of sPUCCH resources and the constellation of the modulation scheme. The combination of the sPUCCH resource selection and the constellation selection of the modulation scheme may indicate HARQ-ACK information for the received sPDSCH(s). If the WTRU receives one or more sPDSCHs associated with the sPUCCH region, HARQ-ACK(k) may be sent, where k may be determined based on the ACK, NACK, or DTX of the received sPDSCH(s). In Table 8, NACK may be used interchangeably with discontinuous transmission (DTX) and NACK / DTX.

[0197] [Table 7]

[0198] In one embodiment, one or more HARQ-ACK(k) association rules or types may be used to support different combinations of sPDSCH scheduling or sPDSCH and normal PDSCH (nPDSCH) scheduling. Table 8 shows an example Type 1 association rule. Table 9 shows an example Type 2 association rule. The one or more HARQ-ACK(k) association rules may be predefined, preconfigured, or determined based on at least one of the number of sPDSCHs associated with an sPUCCH region, the sTTI length of the sPDSCH and / or sPUCCH, or the sTTI time window (e.g., the sTTI time window size). The HARQ-ACK(k) association rule or type for an sTTI time window may be determined based on an indication from a DCI, a first DCI, such as the first DCI in or for the sTTI time window, that may be used to schedule or indicate sTTI resources, an indication from a DCI that may be used to schedule one or more sPDSCHs, the number of sPDSCHs scheduled in the sTTI time window, higher layer configuration, the sTTI time window number, etc. The HARQ-ACK(k) association rule or type for an sTTI time window may also be determined based on a subframe number, a larger time window such as a radio frame, an SFN number, a hyper-SFN number, or a predetermined or known signal that may be used as an sTTI resource indicator, for example, that may be used to indicate the presence of sTTI resources within the sTTI time window.

[0199] [Table 8]

[0200] [Table 9]

[0201] The first HARQ-ACK(k) Type 1 association rule may be used when a WTRU is scheduled for multiple sPDSCHs in the sTTI time window, e.g., four sPDSCHs. The second HARQ-ACK(k) Type 2 association rule may be used when one or more WTRUs can be scheduled for one or more sPDSCHs in the sTTI time window. The Type 1 HARQ-ACK(k) association rule may allow a WTRU to be scheduled with N1 sPDSCHs in the sTTI time window, and the Type 2 HARQ-ACK(k) association rule may allow a WTRU to be scheduled with N2 sPDSCHs. N1 and N2 may be different.

[0202] In one embodiment, the WTRU may perform sPUCCH resource selection for HARQ-ACK transmission or reporting based on several sPDSCH transmissions within the sTTI time window or the number of sPDSCHs associated with the sPUCCH region. The sTTI time window may be determined based on the number of sPDSCHs associated with the sPUCCH region or the sTTI length of each sPDSCH. For example, if the sPDSCH length is Nstti symbols and Nsp sPDSCHs are associated with the same sPUCCH, the sTTI time window may be Nstti × Nsp [symbols]. The sTTI time window may also be a predefined parameter, a configured parameter, a subframe, etc. If a single sPDSCH is received or scheduled within the sTTI time window, the WTRU may use the sPUCCH resource corresponding to the sPDSCH for HARQ-ACK transmission or reporting. If multiple sPDSCHs are received or scheduled within the sTTI time window, the WTRU may determine or select an sPUCCH resource within the set of sPUCCH resources for HARQ-ACK transmission or reporting.

[0203] In some examples and embodiments described herein, two transmissions with different TTIs may be used if one TTI is shorter than the other. The examples and embodiments may apply to any number of transmissions, TTIs, and overlaps. In examples, the shorter TTI may be referred to as sTTI, and the longer TTI may be referred to as nTTI. nTTI may be a normal or regular TTI or subframe that may have a duration of 1 ms. nTTI may be an LTE-A TTI or subframe. A subframe may be a non-limiting example of nTTI. Other TTIs or time periods may be used and still be consistent with the examples and embodiments described herein.

[0204] A PDSCH transmission based on or using nTTIs may be referred to as nPDSCH. A PDSCH transmission based on or using sTTIs may be referred to as sPDSCH. A PUCCH transmission or PUCCH format transmission based on or using nTTIs may be referred to as nPUCCH, and a PUSCH transmission based on or using nTTIs may be referred to as nPUSCH. In examples and embodiments described herein, PDSCH may be used to represent PDSCH, nPDSCH, or sPDSCH. In examples and embodiments described herein, PUSCH may be used to represent PUSCH, nPUSCH, or sPUSCH. In examples and embodiments described herein, PUCCH may be used to represent PUCCH, nPUCCH, or sPUCCH.

[0205] When a PDSCH can be received by a WTRU in TTI n, the associated HARQ-ACK for the PDSCH, such as nPDSCH or sPDSCH, may be transmitted in TTI n+k, where k may be a positive integer. For example, if a WTRU receives an sPDSCH in TTI n, the WTRU may transmit the associated HARQ-ACK in TTI n+k. In the examples and embodiments described herein, the TTI may be replaced by nTTI or sTTI. Additionally, if the TTI length is the same as the subframe length, the TTI may be replaced by a subframe.

[0206] The WTRU may receive an nPDSCH in a subframe. The WTRU may receive one or more sPDSCHs in a subframe, for example, instead of or in addition to the nPDSCH. When the UL HARQ-ACK timing differs between the nPDSCH and the sPDSCH, the associated HARQ-ACKs for both the nPDSCH and the sPDSCH may need to be transmitted or may be scheduled to be transmitted in the same uplink subframe from the WTRU, which may be referred to as a HARQ-ACK collision for the nTTI and the sTTI.

[0207] 18 is an example of a HARQ-ACK collision occurring between nPUCCH and sPUCCH. Communication 1800 may comprise nTTI DL 1802, sTTI DL 1816, nTTI UL A / N 1818, and sTTI UL A / N 1820. A HARQ-ACK collision for nTTI and sTTI may occur when a WTRU receives nPDSCH in nTTI n and sPDSCH(1) and sPDSCH(2) in nTTI n+2, and the WTRU may transmit a HARQ-ACK for these transmissions in the same uplink subframe nTTI n+4 as nPUCCH, sPUCCH(1), or sPUCCH(2).

[0208] HARQ-ACK for nPDSCH may be or may be referred to as normal or nTTI HARQ (nHARQ), nACK, nNACK, nHARQ-ACK, nHARQ-NACK, nACKNACK, etc. nHARQ, nACK, nNACK, nHARQ-ACK, nHARQ-NACK, nACKNACK may be used interchangeably herein. Additionally, HARQ-ACK for sPDSCH may be or may be referred to as short or sTTI HARQ (sHARQ), sACK, sNACK, sHARQ-ACK, sHARQ-NACK, sACKNACK, etc. sHARQ, sACK, sNACK, sHARQ-ACK, sHARQ-NACK, and sACKNACK may be used interchangeably herein. Additionally, HARQ, ACK, NACK, HARQ-ACK, HARQ-NACK, and ACKNACK may be used interchangeably herein.

[0209] In one embodiment, when a WTRU can or may need to transmit nHARQ and sHARQ in a subframe, nHARQ and sHARQ may be multiplexed within a PUCCH transmission. The PUCCH transmission may be an nPUCCH transmission or an sPUCCH transmission. For example, one or more sHARQs may be transmitted together with nHARQ using a single PUCCH transmission or PUCCH format transmission.

[0210] One or more nPUCCH formats may be used, where a first nPUCCH format may be used when nHARQ is transmitted and a second nPUCCH format may be used when nHARQ and sHARQ are multiplexed in a PUCCH transmission. The first nPUCCH format may be or be configured as PUCCH format 1a / 1b, and the second nPUCCH format may be or be configured as PUCCH format 2 / 2a / 2b. The HARQ-ACK bits for sHARQ may be transmitted in the CQI section of PUCCH format 2a / 2b, and the HARQ-ACK bits for nHARQ may be transmitted in the ACK / NACK section of PUCCH format 2a / 2b. The HARQ-ACK bits for nHARQ and sHARQ may be transmitted in the CQI section of PUCCH format 2 / 2a / 2b.

[0211] Additionally, the first nPUCCH format may be PUCCH format 1a / 1b, and the second nPUCCH format may be PUCCH format 3. The first nPUCCH format may be PUCCH format 1a, and the second nPUCCH format may be PUCCH format 1b. When PUCCH format 1b may be utilized, bit locations for nHARQ and sHARQ may be predetermined. For example, the first HARQ-ACK bit in the format may be used for nHARQ, and the second HARQ-ACK bit may be used for sHARQ, or vice versa. When two or more HARQ-ACK bits for nHARQ or two or more HARQ-ACK bits for sHARQ should or will be transmitted, bundling may be utilized. For example, when two or more HARQ-ACK bits for nHARQ may or should be transmitted, one or more HARQ-ACK bits for nHARQ may be bundled. If more than one HARQ-ACK bit for sHARQ may be or should be transmitted, one or more HARQ-ACK bits for sHARQ may be bundled. nHARQ and sHARQ HARQ-ACK bits may be bundled separately or may be bundled separately.

[0212] The nPUCCH format may be a PUCCH format such as a legacy PUCCH format. One or more sPUCCH formats may be used, where a first sPUCCH format may be used if sHARQ is transmitted, e.g., if only sHARQ is transmitted, and a second sPUCCH format may be used if sHARQ and nHARQ are multiplexed within the sPUCCH transmission.

[0213] One or more PUCCH types, which may be nPUCCH types or sPUCCH types, may be used for nHARQ or sHARQ transmissions. The associated DCI for the nPDSCH or sPDSCH may indicate the corresponding PUCCH type to use. For example, the WTRU may receive an indication related to the PUCCH type from the DCI associated with the sPDSCH, and the WTRU may determine the multiplexing of nHARQ and sHARQ based on the indication. The PUCCH type may be a PUCCH format, and vice versa.

[0214] The PUCCH type may be determined based on the number of HARQ-ACK types that can be transmitted, where the HARQ-ACK type may be nHARQ or sHARQ. For example, if one HARQ-ACK type, such as nHARQ or sHARQ, may be transmitted, a first PUCCH type may be used, and if two or more HARQ-ACK types, such as nHARQ and sHARQ, may be transmitted, a second PUCCH type may be used.

[0215] The WTRU can determine the presence of an nPDSCH in an earlier subframe based on the PUCCH type indicated in the DCI. For example, for a subframe in which the WTRU can transmit one or more sHARQs, the WTRU can determine or transmit whether to transmit an nHARQ or whether to also transmit an nHARQ based on the PUCCH type indication. The nHARQ may be associated with an nPDSCH that may have been present but that the WTRU was unable to receive or successfully receive. The WTRU can determine the presence of an nPDSCH associated with the nHARQ for a subframe for HARQ transmission based on the PUCCH type indication. The PUCCH type indication may be received by the WTRU using DCI associated with the sPDSCH transmission for which the sHARQ is to be transmitted. Furthermore, the PUCCH type indication may be replaced by an nPDSCH presence indication. The nPDSCH presence indication may be provided or received in nTTIs, such as nTTIs that may be associated with nHARQ transmissions or nTTIs that may be associated with sHARQ transmissions in the same uplink subframe as nHARQ transmissions for the transmitted nPDSCH. The nTTIs that may be associated with sHARQ transmissions may be nTTIs in which an sPDSCH associated with sHARQ can be received.

[0216] For example, if a WTRU may be able or need to transmit nHARQ and sHARQ in the same subframe, the WTRU may also be able or configured to transmit nHARQ by using an sPUCCH. For example, when the WTRU may not have any uplink transmissions associated with an sTTI, e.g., scheduled or configured uplink transmissions, the WTRU may transmit nHARQ by using an sPUCCH in the sTTI.

[0217] sPUCCH resources in a subframe may be reserved for nHARQ. The WTRU may determine sPUCCH resources for nHARQ in a subframe. The sPUCCH resources for nHARQ in a subframe may be determined based on higher layer signaling, a dynamic indication from DCI, DCI for sPDSCH, sPUCCH in the first sTTI for which the WTRU may not be scheduled, sPUCCH in a reserved sTTI for nHARQ, etc. In the case of a reserved sTTI, a WTRU-specific manner may be utilized to determine the sTTI. WTRU-specific higher layer signaling may be used to indicate or determine the reserved sTTI. One or more WTRU-specific parameters, such as a WTRU-ID, may be used, for example, by the WTRU, to determine the reserved sTTI. The reserved sTTI may be determined in a cell-specific manner or from cell-specific parameters.

[0218] The WTRU may determine available sPUCCH resources in a subframe for transmitting nHARQ. The WTRU may transmit nHARQ in the sPUCCH resources when there are available sPUCCH resources. When sPUCCH resources are not available, the WTRU may be able to or configured to drop one or more nHARQs in the subframe, delay transmission of one or more nHARQs until a later subframe, transmit an sPUCCH for sHARQ and an nPUCCH for nHARQ in parallel, etc. When sPUCCH resources are not available, the WTRU may be able to or configured to multiplex nHARQ and sHARQ within a PUCCH transmission, such as an nPUCCH transmission or an sPUCCH transmission, multiplex nHARQ and sHARQ within a PUSCH transmission, such as an nPUSCH transmission or an sPUSCH transmission, etc.

[0219] A set of sTTI resources in a subframe may be restricted or reserved, for example, for sPUCCH or sHARQ, or an sPUCCH carrying sHARQ. For example, a number of sTTI resources, such as four, may be defined or configured in a subframe, and a subset of that number of sTTI resources may be configured in or used by the WTRU. The configuration may identify or restrict the use of a subset of resources for a particular use, such as sPUCCH or sHARQ, or an sPUCCH carrying sHARQ. The UE may use sTTI resources in the subset for sPUCCH or sHARQ, or an sPUCCH carrying sHARQ. sTTI resources that may not be in the subset may be used as available sPUCCH resources for nHARQ.

[0220] 19 is an example of HARQ transmission on an sPUCCH. Communication 1900 may comprise nTTI DL 1902, sTTI DL 1916, nTTI UL A / N 1920, and sTTI UL A / N 1922. In the example, unused sPUCCH resources in the sTTI may be used for nHARQ transmission. In communication 1900, sPUCCH resources in the second sTTI, i.e., sTTI s+5 in nTTI n+4, may be used for nHARQ transmission because the WTRU may not have an uplink transmission associated with the sTTI. Unused sPUCCH resources may be referred to as sPUCCH resources in an sTTI even when the WTRU may not be scheduled for uplink transmission. Unused sPUCCH resources may be available sPUCCH resources for nHARQ, and vice versa.

[0221] In one embodiment, one or more sPUCCH resources in an sTTI may be used to transmit nHARQ and sHARQ. For example, Ncs sPUCCH resources in an sTTI may be reserved for the WTRU, and one of the reserved sPUCCH resources may be selected or determined based on HARQ-ACK information (e.g., ACK or NACK) of nHARQ.

[0222] The set of sPUCCH resources can be reserved, determined, configured, or used based on the sPUCCH resources associated with the sPDSCH transmission. For example, a first sPUCCH resource in the set may be determined based on one or more parameters of the sPDSCH transmission, and the remainder of the sPUCCH resources in the set may be determined according to a first sPUCCH resource index. Ncs consecutive sPUCCH resource indices from the first sPUCCH resource index may be used for the set. Parameters of the sPDSCH transmission from which the set of sPUCCH resources can be determined may include a starting CCE index of the DCI associated with the sPDSCH transmission, a starting PRB index of the sPDSCH transmission, a starting symbol index of the sPDSCH transmission, a number of allocated PRBs, an MCS level, a transport block size, etc.

[0223] The set of sPUCCH resources may be reserved, determined, configured, or used based on higher layer configuration or dynamic indication from the DCI.

[0224] In examples and embodiments, nHARQ and sHARQ may be substituted or replaced with each other. In examples and embodiments, sPUCCH and nPUCCH may be substituted or replaced with each other.

[0225] For 1-bit nHARQ transmission, two sPUCCH resources in the sTTI may be reserved, allocated, or used, where one of the two sPUCCH resources may be selected or determined by the WTRU based on HARQ-ACK information of nHARQ. For example, a first sPUCCH resource may be selected to indicate nHARQ ACK, and a second sPUCCH resource may be selected to indicate nHARQ NACK. The selected sPUCCH resource may be used for the sHARQ transmission. Alternatively, the sPUCCH resource may be selected or determined based on HARQ-ACK information of sHARQ, and the selected or determined sPUCCH resource may be used for the nHARQ transmission. The HARQ-ACK information may be an ACK or a NACK.

[0226] One or more nPUCCH resources in n TTIs may be used to transmit nHARQ and sHARQ. Ncs nPUCCH resources in n TTIs may be reserved or allocated, and one of the Ncs nPUCCH resources may be selected or determined based on HARQ-ACK information for sHARQ. The selected nPUCCH resource may be used to transmit nHARQ.

[0227] When a WTRU is scheduled to transmit an nPUCCH and an sPUCCH in an sTTI, the WTRU may drop the nPUCCH or sPUCCH transmission in the sTTI if the frequency resources of the nPUCCH and the sPUCCH overlap completely or partially. For the examples given herewith, dropping a transmission may include not transmitting or not transmitting, scaling the power of the transmission to 0, setting the power of the transmission to 0, substantially 0, etc. Dropping an nPUCCH in an sTTI may include dropping an nPUCCH symbol that may be located in the sTTI or dropping the nPUCCH in a subframe. If an sPUCCH in an sTTI is dropped, then no sPUCCH transmission may be made in the sTTI.

[0228] The WTRU may also drop either the nPUCCH or the sPUCCH in an sTTI independent of or substantially independent of the frequency resources that overlap between the nPUCCH and the sPUCCH. When the frequency resources for the nPUCCH and the sPUCCH overlap fully or partially, the WTRU may drop either the nPUCCH or the sPUCCH regardless of the available transmit power or energy. When the frequency resources for the nPUCCH and the sPUCCH do not overlap, the WTRU may drop either the nPUCCH or the sPUCCH in an sTTI based on, for example, the available transmit power or energy in or for the sTTI, or the WTRU maximum transmit power or energy. The available WTRU transmit power or energy may be determined when the total transmit power for transmitting the nPUCCH and the sPUCCH is less than, for example, the maximum WTRU transmit power for the sTTI, for example, P CMAX or P CMAX,c The maximum WTRU transmit power may be determined based on whether the maximum WTRU transmit power exceeds the maximum output power of the WTRU configuration.

[0229] The dropping of nPUCCH or sPUCCH within an sTTI may be determined based on default priority rules for nPUCCH and sPUCCH. For example, sPUCCH may be of higher priority than nPUCCH. The WTRU may drop the lower priority channel. The priority rules may also be based on the information type carried in nPUCCH or sPUCCH. An nPUCCH carrying HARQ-ACK may be of higher priority than an sPUCCH carrying CSI such as CQI / PMI / RI. An sPUCCH carrying HARQ-ACK may be of higher priority than an nPUCCH carrying HARQ-ACK or CSI. Similar priority rules based on information type may apply to nPDSCH or sPDSCH.

[0230] If the nPUCCH and sPUCCH can be located on different frequencies, the WTRU may transmit the nPUCCH and sPUCCH, for example, in parallel, within a short sTTI. The WTRU may transmit or decide to transmit the nPUCCH and sPUCCH simultaneously, for example, within an sTTI, based on at least one of: (i) receiving a higher layer configuration for parallel nPUCCH / sPUCCH transmission; (ii) the WTRU capability for supporting parallel nPUCCH / sPUCCH transmission; (iii) receiving a DCI or DCI for the nPDSCH or sPDSCH that may indicate parallel nPUCCH / sPUCCH transmission or for transmitting nPUCCH / sPUCCH in parallel; or (iv) the WTRU determining that the total transmit power of the nPUCCH and sPUCCH is lower than a predefined threshold. The predefined threshold may be the maximum output power of the WTRU configuration, i.e., P CMAX or P CMAX,c It may be.

[0231] When the WTRU is not configured for parallel nPUCCH / sPUCCH or does not support parallel nPUCCH / sPUCCH, the WTRU may drop the nPUCCH or sPUCCH in a TTI. When the WTRU does not receive a DCI indicating parallel nPUCCH / sPUCCH transmission or for transmitting nPUCCH / sPUCCH in parallel, the WTRU may drop the nPUCCH or sPUCCH in a sTTI.

[0232] When the WTRU determines that the total transmit power or energy of the nPUCCH and sPUCCH is higher than a predefined threshold, the WTRU may drop the nPUCCH or sPUCCH in the sTTI. The predefined threshold may be the maximum output power of the WTRU configuration, i.e., P CMAX or P CMAX,c The total transmit power may be the transmit power of nPUCCH (e.g., P nPUCCH ) and the transmit power of the sPUCCH (e.g., P sPUCCH ) can be determined as a function of

[0233] An sTTI may be or correspond to one or more symbols (e.g., OFDM or SC-FDMA symbols), such as N symbols (where N may be less than 14). An sTTI may correspond to a timeslot. In examples and embodiments, an sTTI may be replaced by an nTTI, or vice versa.

[0234] The WTRU may transmit one or more physical channels or signals, such as one or more of a PUSCH, a PUCCH, a PRACH, an SRS, etc. The WTRU may transmit one or more channels with a TTI, such as nTTI. One or more channel transmissions may be simultaneous or may at least partially overlap or parallel. If the WTRU determines that it will exceed maximum power during the overlap, the WTRU may scale one or more of the channel powers prior to transmission so as not to exceed maximum power. The determination may be based on calculated channel powers that may not take overlap into account. The channel scaling may be based on channel priority, where priority may be defined or known. For example, the PRACH may have the highest priority, the PUCCH may have the next highest priority, a PUSCH carrying UCI may have the next highest priority, and a PUSCH that does not carry UCI may have the next highest priority.

[0235] When a WTRU is to transmit channels with the same TTI, the WTRU can plan ahead based on one or more transmission parameters of the channels, such as scheduling parameters, and can scale the channels as needed. The scaling of the channels can be or may be based on the intended receiver of the channels. For example, a transmission directed to an eNodeB in a dual connectivity scenario can have a minimum guaranteed power, which can affect the power allocation and scaling among the channels to be transmitted.

[0236] The WTRU may transmit one or more of a PUSCH, a PUCCH, a PRACH, an SRS, etc. The WTRU may transmit one or more channels having a TTI, such as an nTTI or an sTTI. One or more sTTI channel transmissions, e.g., a set of sTTI channel transmissions, may at least partially overlap, or may substantially partially overlap, with one or more nTTI channel transmissions or sets of nTTI channel transmissions.

[0237] The term scaling a channel is sometimes used to refer to scaling the power (eg, calculated power) of a channel.

[0238] A WTRU may transmit one or more channels having a TTI, such as nTTI, and / or one or more channels having a TTI, such as sTTI. One or more sTTI transmissions, such as a set of sTTI channel transmissions, may at least partially overlap or parallel with one or more nTTI channel transmissions, such as a set of nTTI channel transmissions. Channel and channel transmission may be used interchangeably herein. A UE may transmit in the UL to one or more eNBs. A UE may transmit in the sidelink to one or more other UEs.

[0239] FIG. 20 is an example of overlapping or parallel TTIs in communications 2000 using nTTIs and sTTIs. For examples provided herein, overlapping portions of channels or resources may be used to refer to a portion of an nTTI channel / resource that overlaps with at least one sTTI channel / resource, or a portion of an sTTI channel / resource that overlaps with at least one nTTI channel / resource. An sTTI may overlap with one, at least one, or only one nTTI. An nTTI may overlap with at least one sTTI. An nTTI may overlap with M or at most M sTTIs. An sTTI may be an UL sTTI or a DL sTTI. An nTTI may be an UL nTTI or a DL nTTI.

[0240] For nTTI configuration 2002 with nTTI as a subframe, which may be 14 symbols or 1 ms in length, and sTTI configuration 2004 with sTTI1 as a timeslot, which may be 7 symbols or 0.5 ms in length, M may be 2. For sTTI configurations 2006 and 2008 with nTTI, which may be comprised of 14 symbols, and sTTI2 or sTTI3, which may be comprised of 4 symbols or 2 symbols, M may be 3 or 7, respectively. The time or overlap relationship between nTTIs and sTTIs may be fixed or known. For communication 2000, an sTTI may be at least partially overlapped by an nTTI, substantially completely overlapped, or completely overlapped. In another example, an sTTI may overlap or partially overlap multiple nTTIs, such as two nTTIs. For example, an nTTI may be an exemplary sTTI1, and an sTTI may be an exemplary sTTI2. In the exemplary communication 2000, the second and fifth occurrences of sTTI2 overlap with two occurrences of sTTI1.

[0241] The set of nTTI channels and the set of short or sTTI channels that may be transmitted by a WTRU may be directed to one, i.e., the same eNodeB, or to one or more serving cells belonging to one, i.e., the same eNodeB. The eNodeB may include or use a scheduler that can schedule or make scheduling decisions for WTRU transmissions. The eNodeB and scheduler may be used interchangeably. The eNodeB may schedule sTTI channels or nTTI channels. The eNodeB may know, for example, exactly or roughly, when the set of sTTI channels and the set of nTTI channels that may be transmitted by a WTRU may partially overlap or be parallel. The eNodeB may know this information because it can schedule both sets of channels.

[0242] Prior to transmitting a set of short or sTTI channels, the WTRU may determine whether the transmission of the set of sTTI channels overlaps or will overlap with the WTRU's transmission of the set of nTTI channels. Prior to transmitting a set of sTTI channels, the WTRU may determine whether the transmission of the set of sTTI channels will cause the WTRU to exceed a maximum power or maximum budget when the sTTI channels overlap with the nTTI channels. The determination may be based, for example, on a channel power calculation without considering the overlap constraint.

[0243] If the WTRU determines that it will exceed the maximum power during the overlap, the WTRU may adjust the power of one or more channels. Such adjustments may be based on channel priority. The WTRU may adjust (e.g., reduce) the power of lower priority channels and may not adjust the power of higher priority channels. The WTRU may transmit the adjusted and / or unadjusted channels.

[0244] The WTRU may determine which channel power or powers to adjust, how to adjust the channel power, on what time scale or time increment to adjust the channel power, etc. This determination may be based on the time relationship between the set of short or sTTI channels and the set of nTTI channels that may overlap (e.g., sTTI / nTTI time relationship), the overlap time between the set of sTTI channels and the set of nTTI channels that may overlap (e.g., sTTI / nTTI time overlap), etc.

[0245] The determination may also be based on whether, prior to the transmission of the set of nTTI channels or prior to the start of the nTTI, the WTRU has scheduling information for a set of sTTI channels that may overlap with the set of nTTI channels. For example, the determination may be based on whether, prior to the transmission of the set of nTTI channels, at least some time prior to such transmission, such as a threshold amount of time, or prior to the start of the nTTI, the WTRU has scheduling information for a set of sTTI channels that may overlap with the set of nTTI channels.

[0246] The determination may also be based on the channel modulation type or MCS of a channel that may be overlapped by another channel. The determination may also be based on the presence of a reference signal, such as a DM-RS, in the overlapped portion of the channel. The determination may also be based on the presence of a reference signal, such as a DM-RS, in the non-overlapping portion of the channel. The determination may also be based on whether a set of sTTI channels that may overlap with a set of nTTI channels may be directed to the same destination, the same serving cell, the same eNodeB, the same base station, the same access point, or the same MAC entity. The determination may also be based on whether a set of sTTI channels that may overlap with a set of nTTI channels may be scheduled by the same scheduler, the same serving cell, the same eNodeB, the same base station, the same access point, or the same MAC entity.

[0247] In this configuration, adjusting the power of a channel or adjusting it may include scaling at least a portion of the channel, such as in time, or dropping at least a portion of the channel, such as in time.

[0248] For some configurations, the WTRU may know the sTTI scheduling information in advance of the nTTI scheduling. For example, the WTRU may expect to receive scheduling information for a set of sTTI channels that may overlap with the set of nTTI channels prior to the transmission of the set of nTTI channels, or at least some time, such as a time threshold, prior to such transmission, or within sufficient time prior to such transmission, or prior to the start of the nTTI. Dropping may be the same as scaling or setting the power to 0. Adjusting a channel may be used to refer to adjusting the power of a channel. Adjusting a channel and adjusting the power of a channel may be used interchangeably.

[0249] The term overlap portion of a channel may refer, for example, to a portion of a channel that overlaps, in time, with another channel. For example, the overlap portion of a channel may be used to refer to a portion of an nTTI channel that overlaps with at least one sTTI channel, or a portion of an sTTI channel that overlaps with at least one nTTI channel. The overlap portion and overlapped portion may be used interchangeably.

[0250] When the WTRU has the scheduling information, power adjustments may be made. The WTRU may know the sTTI scheduling information in advance of the nTTI. For example, the WTRU may know or receive scheduling information for a set of sTTI channels that may overlap with the set of nTTI channels prior to transmission of the set of nTTI channels, at least some time prior to such transmission, e.g., a time threshold, or sufficient time prior to such transmission, or prior to the start of the nTTI.

[0251] For example, when the WTRU knows sTTI scheduling information in advance of nTTI, the WTRU may determine which channel or channels to tune, such as short or sTTI or nTTI channels, prior to the nTTI transmission or prior to nTTI. The WTRU may determine which channel or channels to tune based on a channel priority rule, such as a normal or legacy channel priority rule.

[0252] For a channel determined to be adjusted, for example, when the WTRU knows scheduling information n TTIs in advance, the WTRU may perform channel adjustments over the entire TTI or substantially the entire TTI (e.g., sTTI or nTTI) of the channel. As an example, when the overlap is equal to or greater than a threshold, the WTRU may perform adjustments over the entire TTI or substantially the entire TTI (e.g., sTTI or nTTI) of the channel. The threshold may be fixed, defined (e.g., predefined), configurable, etc., and may be received from a base station such as an eNodeB. The threshold may be, for example, 3 or 4 symbols.

[0253] For sTTI channels determined to be adjusted, e.g., when and / or always when the WTRU knows the sTTI scheduling information nTTIs in advance, the WTRU may adjust across the entire sTTI or substantially the entire sTTI of the channel. For nTTI channels determined to be adjusted, e.g., when the WTRU knows the sTTI scheduling information nTTIs in advance, the WTRU may adjust across the entire nTTI or substantially the entire nTTI of the channel when the overlap is above a threshold.

[0254] For channels determined to be adjusted, for example, the WTRU may, at least occasionally, adjust to the overlapping portion of the channels, eg, only the overlapping portion of the channels.

[0255] For example, for channels determined to be adjusted, when the overlap is below or equal to a threshold, e.g., 1 or 2 symbols, or between two thresholds, e.g., between 1 and 2 symbols, the WTRU may adjust to, e.g., only, the overlapping portions of the channels. The one or two thresholds may be configurable and may be received from the base station or eNodeB. The WTRU may transmit adjusted and / or unadjusted channels.

[0256] The WTRU may not know the sTTI scheduling information prior to the nTTI. For example, prior to the transmission of the set of nTTI channels (e.g., at least some time prior, such as a time threshold, or sufficiently prior thereto), or prior to the start of the nTTI, the WTRU may not know, e.g., may not receive, scheduling information for a set of sTTI channels that may overlap with the set of nTTI channels.

[0257] For example, when the WTRU may not know the sTTI scheduling information prior to the nTTI, the WTRU may determine which channel or channels (e.g., the sTTI channel and / or the nTTI channel) to adjust prior to the nTTI transmission or prior to the nTTI. For example, the WTRU may not know or receive scheduling information for a set of sTTI channels that may overlap with the set of nTTI channels prior to the transmission of the set of nTTI channels or prior to the start of the nTTI. The WTRU may determine which channel or channels to adjust based on channel priority rules (e.g., normal or legacy channel priority rules) and / or other rules.

[0258] For nTTI channels to be adjusted, for example, when the WTRU does not know sTTI scheduling information nTTIs in advance, the WTRU may adjust to the overlapping portion of the channel.

[0259] For an sTTI channel to be adjusted, for example, when the WTRU does not know the sTTI scheduling information prior to the nTTI, the WTRU may adjust over the entire sTTI (e.g., over substantially the entire sTTI) or over the overlap time between the nTTI and sTTI channels.

[0260] For an sTTI channel to be adjusted, for example, when the WTRU does not know the sTTI scheduling information prior to nTTI, the WTRU may adjust for the entire sTTI (e.g., substantially across the entire sTTI) when the overlap with nTTI exceeds a threshold, e.g., one symbol, or always.

[0261] For an sTTI channel to be adjusted, the WTRU may adjust on the overlapping portion, eg, only the overlapping portion, if the overlap with the nTTI is below a threshold, eg, 1 symbol.

[0262] The WTRU may perform short, or sTTI, channel adjustment over the entire sTTI, substantially the entire sTTI, or over the overlap time between the nTTI and sTTI channels. This operation may be performed when sTTI scheduling information is unknown prior to the nTTI. This operation may also be performed when the overall sTTI overlap with the nTTI exceeds a threshold, e.g., a predetermined number of symbols.

[0263] For sTTI channels that are to be adjusted (e.g., scaled), the WTRU may make adjustments to the overlapping portion without adjustments to the other portions. The WTRU may perform this operation if the overlap with nTTI is below a threshold, e.g., 1 symbol.

[0264] For channel adjustments to be made to a portion of a channel, if the portion to be adjusted includes a portion of a symbol, the WTRU may adjust the channel within the complete symbol (e.g., according to the adjustments determined for one or more complete symbols). The WTRU may perform this action if the partial overlap is greater than a threshold.

[0265] If the portions of the channels to be adjusted span full and partial symbols, the rules for determining which channels to adjust may apply to the full symbols and / or to symbols that are overlapped by at least a threshold amount, e.g., only to such symbols. Adjustments across the remaining partially overlapped symbols may follow other rules or be left to the WTRU implementation.

[0266] For channel adjustments to be made to a portion of a channel, if the portion to be adjusted includes a portion of a symbol, how the power in the partially overlapped symbols should be adjusted so as not to exceed the maximum power during the partially overlapped symbols may follow various rules or may be left to the WTRU implementation, for example, if the partial overlap is below a threshold.

[0267] If the portion of the channel to be adjusted spans a full symbol and a partial symbol, the rule for determining which channel, symbol, or full symbol to adjust may be based on overlapping by at least a threshold amount. Additionally, channel power or energy adjustment in partially overlapped symbols may be performed by the WTRU according to different rules or thresholds so as not to exceed a maximum power during the partially overlapped symbols.

[0268] Scaling a portion of a channel may affect performance for modulation schemes that may use constellation amplitude information, such as, for example, quadrature amplitude modulation (QAM) or x-QAM (where x may be 16, 64, 256, or another integer). Scaling a portion of a channel may not affect performance for modulation schemes that may not use constellation amplitude information, such as, for example, BPSK or QPSK.

[0269] The WTRU may determine a channel to be adjusted, for example, according to the examples herein. The WTRU may determine whether to scale or drop a portion of the channel to be adjusted based on the modulation scheme used for the channel, e.g., based on whether the modulation scheme used for or by the channel may use amplitude. For example, the WTRU may determine to drop (or scale) a portion of the channel when the modulation scheme used for the channel transmission does not use amplitude, e.g., when the modulation scheme is QPSK or BPSK.

[0270] For example, the WTRU may determine that a portion of a channel should be adjusted, e.g., at the nTTI / sTTI overlap time. The WTRU may determine whether to scale or drop a portion of a channel based on the modulation scheme used for the channel. For example, the WTRU may determine that a portion of a channel should be scaled (or dropped) when the modulation scheme used for channel transmission uses amplitude, e.g., when the modulation scheme is QAM or x-QAM. The WTRU may determine that a portion of a channel should be dropped (or scaled) when the modulation scheme used for channel transmission does not use amplitude, e.g., when the modulation scheme is QPSK. The WTRU may scale or drop the portion of the channel according to the determination.

[0271] The WTRU may transmit a partially modulated channel that may have portions scaled or dropped based on, for example, the modulation scheme used.

[0272] Adjusting, e.g., scaling and / or dropping, a portion (e.g., any portion) of the channel may be applied to a complete symbol. If the overlapping portion spans one or more complete symbols and portions of one or more symbols, the WTRU may apply the adjustment to the entire symbol, which may be partially overlapped, e.g., if the partial overlap is greater than a threshold. The WTRU may not apply the adjustment to a symbol if the overlap is less than a threshold.

[0273] A base station (e.g., an eNodeB) may be aware of possible adjustments, e.g., due to a WTRU's power limitations or power budget, and may adapt or account for the adjustments when receiving or decoding a channel transmitted by the WTRU. For example, the base station may be aware of the time location of possible adjustments because nTTI and sTTI transmissions may be based on scheduling by the base station. The base station may be aware that the WTRU may scale or drop based on the modulation used for transmission. The base station may take this knowledge into account when receiving and / or decoding a channel transmitted by the WTRU.

[0274] The WTRU may consider signal priority, such as physical layer signals, in determining which channel or channels to tune, or may also consider such priority. For example, the DM-RS may have priority. The WTRU may consider the priority of the DM-RS when determining which channel or channels to tune. The DM-RS is used as a non-limiting example. Other single or multi-symbol signals may be used and still be consistent with this disclosure.

[0275] For example, regardless of the relative priorities of nTTI and sTTI channels when reference signals are not considered, for example, an nTTI channel that has a DM-RS during a short, overlapping time with an sTTI channel may have a higher priority than an sTTI channel. Giving a higher priority to a channel that has a DM-RS during the overlap can avoid the DM-RS from being scaled or punctured.

[0276] The WTRU may determine that the maximum power or maximum energy may be exceeded for or during short, i.e., overlap between the sTTI channel and the nTTI channel. The WTRU may determine that the nTTI channel includes a DM-RS in the overlap. The DM-RS may have a higher priority than one or more channels, such as one or more of the PUCCH, the PUSCH with UCI, and the PRACH. If the sTTI channel with which the nTTI channel may overlap is a channel with a lower priority than the DM-RS, the WTRU may determine that the sTTI channel should be adjusted. If the sTTI channel with which the nTTI channel may overlap is a channel that does not have a lower priority than the DM-RS, the WTRU may determine which channel to adjust based on its regular rules, e.g., channel priority and / or guaranteed power (e.g., guaranteed minimum power) rules.

[0277] If an nTTI channel includes multiple DM-RSs and at least one DM-RS in the nTTIs is not in the overlapping time, the presence of the DM-RS in the overlapping time may not be considered (e.g., by the WTRU) when determining channel priority or channel adjustment. The DM-RS in the overlapping time may be scaled or punctured, for example, according to one or more examples described herein.

[0278] If an nTTI channel includes multiple DM-RSs, and at least one DM-RS in the nTTIs precedes the overlap time, the presence of the DM-RS in the overlap time may not be considered (e.g., by the WTRU) when determining channel priority or channel adjustment. The DM-RS in the overlap time may be scaled or punctured, for example, according to one or more examples described herein.

[0279] When the WTRU knows the sTTI scheduling information in advance of nTTIs, the presence of a DM-RS in the overlapping time may not be considered (e.g., by the WTRU) when making channel priority or channel adjustment decisions. In this configuration, the WTRU may or may be able to scale the nTTI channel across the entire nTTI or substantially the entire nTTIs, and scaling the DM-RS may be acceptable. When the WTRU knows the sTTI scheduling information in advance of nTTIs, the presence of a DM-RS in the overlapping time may be considered (e.g., by the WTRU) when making channel priority or channel adjustment decisions.

[0280] The base station may take into account possible DM-RS scaling and / or puncturing in the overlapping time, and may, for example, use or only use the DM-RS in the non-overlapping time for channel demodulation.

[0281] For example, because a short or sTTI channel may be coordinated across the entire sTTI or substantially the entire sTTI, an nTTI channel that has a DM-RS during its overlap time with a short or sTTI channel may have a higher priority than the short or sTTI channel, for example, regardless of whether the short or sTTI channel includes a DM-RS in the overlap.

[0282] In some configurations (e.g., sometimes or always), an nTTI DM-RS may have priority over a short or sTTI DM-RS. For example, when the WTRU may not know the sTTI scheduling information prior to the nTTI, the nTTI DM-RS may have priority over a short or sTTI DM-RS. For example, when the nTTI channel does not include a DM-RS in the overlap, a short or sTTI channel that has a DM-RS during the overlap time with the nTTI channel may have higher priority than the nTTI channel. For a short or sTTI channel to be adjusted, when the short or sTTI channel includes a DM-RS or when the overlapping portion of the channel includes a DM-RS, the WTRU may adjust for the entire sTTI or substantially the entire sTTI.

[0283] The WTRU may consider TTI length priority when deciding which channel or channels to tune, or may also consider such priority. For example, TTI length priority may be used for channels with the same channel and / or signal priority but different TTI lengths. Short or sTTI channels may have higher priority than nTTI channels, or vice versa. Which TTI length has higher priority may be configured. The configuration may be per serving cell.

[0284] One or more DM-RS patterns can be defined, configured, and / or used, for example, by the WTRU. The configuration can be provided to and / or received by the WTRU, for example, by a base station. The one or more DM-RS patterns can be considered a set of patterns. One of the set can be a default regular or normal pattern or can be configured as such. The pattern can indicate, for example, in what symbol or symbols the WTRU can transmit the DM-RS when transmitting a PUCCH or PUSCH channel.

[0285] The WTRU may use or modify the DM-RS pattern of a channel (e.g., a short or sTTI channel or an nTTI channel) based on an indication that may be provided. The indication may be provided and / or received in a scheduling grant, a DL control channel such as a PDCCH or EPDCCH, a DCI format, etc. The indication may be referred to as a DM-RS indicator. The indication may be provided by the base station. The indication may be received by the WTRU.

[0286] The DM-RS indicator may indicate a DM-RS pattern to use when transmitting, for example, in the UL. For example, the DM-RS indicator in a DL grant may indicate a pattern to use when transmitting a PUCCH, which may include an ACK / NACK for a DL transmission. The DM-RS indicator in a UL grant may indicate a pattern to use when transmitting a PUSCH scheduled by the UL grant. The WTRU may receive the indication. The WTRU may transmit a channel associated with the DL grant, for example, the granted PUSCH or PUCCH, using the indicated DM-RS pattern.

[0287] The DM-RS indicator may indicate whether a DM-RS (e.g., any DM-RS) should be included in the UL transmission. Based on the received DM-RS indicator, the WTRU may transmit a channel using a DM-RS pattern, e.g., the indicated DM-RS pattern, or without a DM-RS pattern. The DM-RS indicator may indicate, e.g., to move or place a DM-RS of a first channel, e.g., a short or sTTI channel, from its default or regular location so that it aligns with a DM-RS of a second channel, e.g., an nTTI channel, with which the first channel may overlap. The WTRU may use or modify the DM-RS pattern of a first channel (e.g., a short or sTTI channel) so that one or more DM-RS align (e.g., in time) with a DM-RS in a second channel, e.g., an nTTI channel, e.g., an overlapping second channel. The WTRU may use or modify the DM-RS of a first channel based on the received DM-RS indicator, which may indicate to do so.

[0288] In one or more examples described herein, the first channel may be a short or sTTI channel and the second channel may be an nTTI channel, or, for example, when the WTRU knows the sTTI scheduling information nTTI in advance.

[0289] The WTRU may determine that a first channel, e.g., a short or sTTI channel, and a second channel, e.g., an nTTI channel, may overlap. The WTRU may use or modify the DM-RS pattern of the first channel such that one or more DM-RSs align (e.g., in time) with the DM-RSs in the second channel. This operation may be performed by the WTRU based on a determination that the first and second channels may overlap. Additionally, the WTRU may use or modify the pattern autonomously, e.g., without explicit indication from the base station. The WTRU may use or modify the pattern autonomously, e.g., when the overlapping short or sTTI and nTTI channels may be directed to the same eNodeB or to serving cells of the same eNodeB.

[0290] The WTRU may use or modify the DM-RS pattern of a second channel (e.g., an nTTI channel) such that one or more DM-RS of the second channel, which may overlap with the first channel, do not overlap with the second channel. The WTRU may use or modify the DM-RS pattern of the second channel, for example, based on an indication received from the base station or autonomously (e.g., without explicit indication). The WTRU may have or be configured to have a configured or default DM-RS pattern for the second channel. The WTRU may move at least one DM-RS of the second channel, which may overlap with the first channel, to a symbol after the end of the overlap, such as the first symbol after the overlap.

[0291] The WTRU may puncture data intended for symbols to be used for the DM-RS (e.g., later symbols). The WTRU may change at least one intended symbol for the data. For example, if the DM-RS in symbol 5 is moved to symbol 8, then the data intended for symbols 6, 7, and 8 may be shifted to symbols 5, 6, and 7, respectively.

[0292] Transmissions by the WTRU may be prioritized. The set of nTTI channels and the set of short or sTTI channels that may be transmitted by the WTRU may be directed to different base stations (e.g., eNodeBs) or to one or more serving cells belonging to different base stations (e.g., eNodeBs). A base station may schedule the short or sTTI channels, and another base station may schedule the nTTI channels. The base station may not know when the set of short or sTTI channels and the set of nTTI channels that may be transmitted by the WTRU may overlap.

[0293] Prior to transmission of a set of short or sTTI channels, the WTRU may determine whether the set of sTTI channels may overlap with the set of nTTI channels and whether the maximum power or maximum energy may be exceeded during the overlap. If or when the WTRU determines that it will exceed the maximum power or maximum energy during the overlap, the WTRU may adjust the power or energy of one or more channels.

[0294] Embodiments that may be described for WTRU communication with one base station, eNodeB, or scheduler may apply to WTRU communication with two or more base stations, eNodeBs, or schedulers, and vice versa. Application to one scenario or another is for illustrative and not limiting purposes.

[0295] For n TTIs, when scheduling information for short, i.e., sTTI channels is not known prior to the n TTI transmission, e.g., a threshold amount of time prior to the n TTI transmission, the WTRU can use a virtual grant or allocation for one or more short, i.e., sTTI channels to determine the power or energy available for the n TTI channels. The terms grant and allocation may be used interchangeably. A virtual allocation may be a configured allocation that may have a configured set of one or more parameters. The virtual allocation may be configured by higher layer signaling, e.g., from a base station. The parameters may include at least one of a channel indicator, e.g., an indication of a PUSCH channel and / or a PUCCH channel, and / or scheduling information, e.g., resource allocation information for the PUSCH and / or PUCCH. The virtual allocation may be determined, e.g., by the WTRU, based on at least one previous transmission in the sTTI, such as an sTTI transmission, e.g., an UL sTTI transmission and / or a DL sTTI transmission, in the previous n TTIs or subframes. The virtual allocation may be determined, for example, by the WTRU, based on at least one previous transmission in an sTTI, such as one or more sTTI transmissions, e.g., an sTTI UL and / or DL ​​transmission, in the last N nTTIs. For example, N may be 1 or 2. N may be configurable by higher layers. N may be a function of one or more of the sTTI length, the maximum sTTI length, and / or the nTTI length.

[0296] The virtual allocation may be based on scheduling or resource allocation for at least one UL and / or DL ​​channel or transmission, e.g., at least one UL and / or DL ​​channel scheduled, allocated, or transmitted in the previous n TTIs or subframes. For example, if the WTRU transmitted an sPUSCH in the previous n TTIs (e.g., the previous subframe), the WTRU may use a scaled version of the scheduling information and / or calculated power or resource allocation of the previous PUSCH for that sPUSCH as the scheduling information or calculated power for the virtual sPUSCH for the current n TTI. In another example, the WTRU may use a scaled version of the calculated power of the previous PUSCH for the virtual sPUSCH. The scale factor may be configured and / or be a function of the time elapsed since the sPUSCH was transmitted, e.g., if the last sPUSCH was transmitted more than one n TTI earlier.

[0297] The WTRU may determine the power allocation for the nTTI channels in the normal manner, using the virtual short or sTTI channels and / or virtual short or sTTI channel powers instead of the actual short or sTTI channels and / or channel powers. The WTRU may determine the power allocation over the entire nTTI or substantially the entire nTTI. The WTRU may apply the determined power allocation over the nTTI. For example, for short or sTTI channels scheduled after the start of the nTTI transmission, the WTRU may adjust the power for the nTTI during the nTTI, e.g., if an unaccounted short or sTTI channel is scheduled and / or allocated. For the calculation of the power of the channel for the virtual sTTI, the WTRU may use the path loss used for the actual transmission when the channel was previously transmitted, or the WTRU may calculate the power using a more recent or current path loss.

[0298] A virtual channel may be applicable to one or more channel types, or may only be applicable to those channel types. For example, a virtual channel type may be applicable to one or more of a PUCCH, a PUSCH, and a PUSCH carrying UCI. The WTRU may use DL traffic, e.g., previous PDSCH scheduling and / or reception, to determine the virtual PUCCH allocation. The WTRU may use UL traffic, e.g., previous PUCCH allocation or transmission, to determine the virtual PUCCH allocation. The WTRU may use UL traffic, e.g., previous PUSCH scheduling and / or transmission, to determine the virtual PUSCH allocation.

[0299] The WTRU may use, or may determine to use, a virtual allocation for an sTTI based on the number of short or sTTI channels, i.e., Ncstti, that were scheduled, allocated, and / or transmitted in the previous M nTTIs. M may be 1, 2, or any number and may be configured by higher layers. If Ncstti exceeds a threshold (e.g., if the WTRU determines that Ncstti exceeds a threshold), the WTRU may use the virtual allocation for one or more short or sTTI channels when determining the power for the nTTI.

[0300] If Ncstti does not exceed a threshold (e.g., if the WTRU determines that Ncstti does not exceed a threshold), the WTRU may not use the virtual allocation for one or more sTTI channels when determining the power for nTTI. For example, if a short or sTTI channel was not scheduled, allocated, and / or transmitted in the last M nTTIs, the WTRU may not use the virtual allocation for the power determination for nTTI.

[0301] If a short or sTTI transmission, e.g., a short or sTTI transmission that may not have been accounted for in determining the nTTI power, is scheduled or allocated and it is determined that the maximum power may be exceeded for or during the sTTI, one or more short or sTTI or nTTI channels or signals may be adjusted or modified to avoid exceeding the maximum power, e.g., in accordance with one or more of the embodiments described herein.

[0302] The WTRU may include an indication in an nTTI transmission, e.g., to indicate to the base station, that the transmission of a channel has been modified due to a maximum power condition encountered on one or more short or sTTI channels. The WTRU may include an indication in the last symbol, in one or more PRBs that may be configured or used for such an indication, etc.

[0303] The WTRU may be configured for and / or use nTTI in the first serving cell and sTTI in the second serving cell. The first and second serving cells may be the same or different serving cells. The WTRU may use carrier aggregation, for example, to aggregate carriers of the first and second serving cells. The first and second serving cells may have or belong to the same or separate schedulers, MAC entities, base stations, and / or eNodeBs. Dual connectivity may be applied to the first and second serving cells.

[0304] For a TTI, eg, an nTTI or an sTTI, the WTRU or MAC entity may determine whether at least one PHR may have been triggered, eg, using the PH reporting procedure of the WTRU or MAC entity.

[0305] The MAC entity may transmit a PHR, for example, when the WTRU determines that a PHR may have been triggered. The WTRU may transmit a PHR, for example, in a MAC-CE and / or on a PUSCH or sPUSCH channel, for example, when the WTRU determines that a PHR may have been triggered. The WTRU may transmit a PHR on a channel for which the WTRU may have a resource grant or allocation, for example, on a PUSCH or sPUSCH, for example, when the WTRU may have UL resources that may be for a new transmission.

[0306] A MAC entity can or may be configured, e.g., by signaling, to prioritize transmission of PHRs and / or other MAC-CEs in one TTI length over another TTI length. In one example, a MAC entity that may be configured with and / or capable of using nTTIs and sTTIs may determine, or may only determine, whether at least one PHR has been triggered for the nTTI or the sTTI, e.g., for one of the nTTIs or the sTTIs. In another example, a MAC entity that may be configured with and / or capable of using nTTIs and sTTIs may transmit, or may only transmit, a PHR in an nTTI resource, e.g., a PUSCH, or an sTTI resource, e.g., an sPUSCH, when both nTTI and sTTI resources may be available.

[0307] An sTTI, e.g., a UL sTTI, may, for example, overlap with at least one or only one nTTI, e.g., a UL nTTI. An nTTI may overlap with at least one sTTI. An nTTI may overlap with M, e.g., at most M, sTTIs.

[0308] A PHR, e.g., a PHR that may be transmitted within an nTTI, may include a PH for the nTTI and one or more PHs that may correspond to sTTIs that may overlap with the nTTI. A PHR that may be transmitted within an sTTI may include a PH for the sTTI and one or more PHs that may correspond to nTTIs that may overlap with the sTTI.

[0309] The WTRU may send, e.g., transmit, a PHR to, e.g., a base station. The PHR may include at least one of the following, e.g., the WTRU may include at least one of the following in the PHR: a PH that can correspond to an nTTI (nTTI PH), e.g., an nTTI that may overlap with an sTTI for which a PH may be reported; a PH that can correspond to an sTTI (sTTI PH), e.g., an sTTI that can overlap with an nTTI for which a PH may be reported; a set of sTTI PHs, e.g., an sTTI for or for each sTTI in a set of sTTIs that may overlap with an nTTI for which a PH may be reported. PH; for example, an indication that the sTTI channel or the influence of the sTTI or sTTI channel may be included in the calculation and / or determination of at least one of the power, the maximum power that may be reported, and / or the PH that may be reported for the nTTI; an indication of the sTTI, for example, which sTTI may be reported in the PHR or may be included in the PHR for which PH, for example, an indication of an sTTI within a set of sTTIs that may overlap with an nTTI for which PH may be reported; CMAX,c ; sTTI compatible P CMAX,ca virtual / real indicator flag or field (V flag) for the nTTI PH, which may indicate whether the corresponding nTTI PH may be real or virtual, e.g., may be based on a real transmission or reference format; a virtual / real indicator flag or field (V flag) for the sTTI PH, which may indicate whether the corresponding sTTI PH may be real or virtual, e.g., may be based on a real transmission or reference format; a power management flag or field, e.g., a P flag, which may be reported and may be used in calculating and / or determining the PH, e.g., which may be reported; CMAX,c A P flag for the PH or each PH that can indicate whether power backoff due to power management may be applied when determining the

[0310] The PH, e.g., sTTI PH and / or nTTI PH, which may be included in the PHR, may be real or virtual. PH determination and / or PH reporting may be configured, provided, supported, and / or used, e.g., when supporting nTTI and sTTI. As used herein, the terms calculate or calculate and determine or determine may be interchangeable in the disclosed examples and embodiments.

[0311] There may be one or more PH types. For example, Type 1 PH may be a PH for a PUSCH. Type 1 PH may be calculated from or based on PUSCH power. Type 1 PH may not include PUCCH channel power, e.g., may not be calculated from or based on PUCCH channel power. Type 1 PH may include the impact of PUSCH transmission, e.g., scheduling of PUSCH transmission, on the maximum power that may be used to determine the PH. Type 1 PH may not include the impact of PUCCH transmission, e.g., scheduling of PUCCH transmission, on the maximum power that may be used to determine the PH. Type 1 PH may be a real PH when a PUSCH may be transmitted within the TTI for which the PH may be calculated. Type 1 PH may be a virtual PH, e.g., a reference format may be used, when a PUSCH may not be transmitted within the TTI for which the PH may be calculated.

[0312] In one example, Type 2 may be a PH for a PUSCH and / or a PUCCH. Type 2 PH may be calculated from or based on PUSCH power and / or PUCCH power. Type 2 PH may be calculated from or based on PUSCH power, for example, when PUSCH transmissions may occur within the TTI for which PH may be calculated. Type 2 PH may be calculated from or based on PUCCH power, for example, when PUCCH transmissions may occur within the TTI for which PH may be calculated. Type 2 PH may include the effect of PUSCH and / or PUCCH transmissions, for example, that may occur within the TTI for which PH may be calculated, on the maximum power that may be used to determine PH.

[0313] When the PUSCH and / or PUCCH may not be transmitted within the TTI for which the PH may be calculated, the reference format may be used for the PUSCH and / or PUCCH. When both the PUSCH and the PUCCH can use the reference format, the Type 2 PH may be considered or denoted as virtual.

[0314] A PH type may apply to a TTI type or TTI length, or to a channel as a TTI type or TTI length. For example, for an sTTI in and / or for which a PH may be reported, a Type A PH may be an sTTI PH. An sTTI PH may be a Type A PH.

[0315] A Type-A PH may be a PH for an sPUSCH. A Type-A PH may be a Type-1 PH in which the PUSCH may be an sPUSCH. A Type-B PH may be a PH for an nPUSCH. A Type-B PH may be a Type-1 PH in which the PUSCH may be an nPUSCH. A Type-C PH may be a PH for an nPUSCH and / or an sPUSCH that may at least partially overlap. A Type-C PH may be calculated from or based on nPUSCH power and / or sPUSCH power, e.g., the power of one or more of an nPUSCH and an sPUSCH that may overlap. For example, when an nPUSCH transmission may occur within a TTI for which a PH may be calculated, e.g., nTTI, a Type-C PH may be calculated from or based on nPUSCH power. For example, when nPUSCH transmissions occur in a TTI, e.g., nTTI, in which or for which a PH may be reported, a Type-C PH may be calculated from or based on the nPUSCH power. For example, when nPUSCH transmissions may overlap with sTTIs in which or for which a PH may be reported, a Type-C PH may be calculated from or based on the nPUSCH power. For example, when sPUSCH transmissions may occur in a TTI (e.g., sTTI) for which a PH may be calculated, a Type-C PH may be calculated from or based on the sPUSCH power. For example, when sPUSCH transmissions may occur in a TTI (e.g., sTTI) in which or for which a PH may be reported, a Type-C PH may be calculated from or based on the sPUSCH power. For example, Type-C PH may be calculated from or based on the sPUSCH power when sPUSCH transmissions may overlap n TTIs in or for which PH may be reported.Type-C PH may include the effect on the maximum power that can be used to determine PH of, for example, nPUSCH and / or sPUSCH transmissions that may occur within or overlap with the TTIs for which PH may be calculated.

[0316] A Type-D PH may be a PH for nPUSCH and / or nPUCCH. A Type-D PH may be a Type-2 PH where the PUSCH may be nPUSCH and the PUCCH may be nPUCCH. A Type-E PH may be a PH for sPUSCH and / or sPUCCH. A Type-D PH may be a Type-2 PH where the PUSCH may be sPUSCH and the PUCCH may be sPUCCH. A Type-F PH may be a PH for nPUSCH, sPUSCH, nPUCCH, and / or sPUCCH. A Type-F PH may be calculated from or based on nPUSCH power as described herein for one or more of PH types B, C, and D. A Type-F PH may be calculated from or based on sPUSCH power as described herein for one or more of PH types A, C, and E. A Type-F PH may be calculated from or based on nPUCCH power as described herein for PH Type D. A Type-F PH may be calculated from or based on sPUCCH power as described herein for PH Type E. A Type-F PH may include the effect on the maximum power that may be used to determine PH, for example, of nPUSCH, sPUSCH, nPUCCH, and / or sPUCCH transmissions that may occur within or overlap with the TTI for which PH may be calculated.

[0317] An sTTI PH may be a PH as at least one of types A, C, E, and / or F. An nTTI PH may be a PH as at least one of types B, C, D, and / or F. A PHR may include one or more PH types, e.g., for a serving cell, e.g., one or more of PH types 1, 2, A, B, C, D, E, and / or F. A PH may be a real PH or a virtual PH. A real PH may use or be based on real transmission parameters, e.g., scheduling information. A virtual PH may use or be based on a reference format, e.g., reference scheduling information.

[0318] A PH may be a realistic PH when a channel that may be used to determine a PH may be transmitted within the TTI for which the PH may be calculated. A PH may be a realistic PH when scheduling information for a channel that may be used to determine a PH may be available for PH calculation, for example, for the TTI for which the PH may be calculated.

[0319] A PH may be a virtual PH when a channel that may be used to determine a PH may not be transmitted within a TTI for which the PH may be calculated. A PH may be a virtual PH when scheduling information for a channel that may be used to determine a PH may not be available, for example, for a PH calculation for a TTI for which the PH may be calculated.

[0320] For a PHR that may be reported in an nTTI, at least one of the power, maximum power, and PH may be determined based on the nTTI scheduling and available, e.g., worst-case available, overlapping sTTI scheduling, and / or the PHR may include the nTTI PH and sTTI PH for one or more overlapping sTTIs.

[0321] As used herein, the terms scheduling and scheduling information may be used interchangeably. The scheduling information may include at least one of a resource grant or allocation, which may include frequency locations, such as frequency locations for several RBs and / or a set of RBs, a processing parameter, such as a TBS or number of coded bits, a UCI or number of HARQ feedback bits, a modulation and coding scheme (MCS), etc. The scheduling information may be received, decoded, and / or determined prior to transmission. The availability of scheduling information, e.g., sTTI for nTTIs, may vary depending on when the scheduling information can be received, decoded, and / or determined prior to transmission, e.g., nTTIs prior to transmission.

[0322] The scheduling information may be for a channel such as a PUSCH or a PUCCH. The scheduling information may vary depending on the type of bits, e.g., UCI or data bits, that may be transmitted in a TTI or on a channel. The scheduling information for an UL transmission may be determined based on a DL transmission. For example, the number of HARQ feedback or UCI bits that may be transmitted may be determined based on a DCI that may provide a DL grant.

[0323] The calculation and / or determination of nTTI PH and one or more associated values ​​that may be used in calculating and / or determining PH, for example, may use scheduling information for nTTI. The associated value may be at least one of power or maximum power.

[0324] For n TTI of a serving cell, e.g., a first serving cell, the WTRU may determine a scheduled transmission for the serving cell n TTI, e.g., a power for a channel, e.g., a physical channel of the serving cell, e.g., a maximum power for the serving cell, and / or a PH, based at least on parameters of the scheduled transmission, e.g., a number of RBs for the scheduled transmission. The scheduled transmission may be a PUSCH transmission or a PUCCH transmission. The scheduled transmission may be a transmission for which resources may be implicitly or explicitly granted or allocated. For example, a PUCCH or sPUCCH transmission for transmitting HARQ feedback may be considered a scheduled transmission.

[0325] The maximum power for a serving cell, e.g., a first serving cell, may be affected by another serving cell, e.g., a second serving cell, which may be an in-band serving cell, e.g., a neighboring in-band serving cell. The WTRU may determine the maximum power based at least on a scheduled transmission for the other serving cell, e.g., the second serving cell, e.g., an nTTI that may overlap the serving cell nTTI completely or at least by a fixed or configured amount, e.g., the in-band serving cell nTTI.

[0326] The calculation and / or determination of the nTTI PH and one or more associated values ​​may use scheduling information for overlapping sTTIs, e.g., when the scheduling information may be available. For a serving cell nTTI, e.g., a first serving cell nTTI, the WTRU may determine, e.g., the power for a channel, such as a physical channel of the serving cell, e.g., the maximum power for the serving cell, and / or PH, based on scheduled transmissions for an sTTI of the serving cell (and / or another, e.g., second serving cell) that may overlap with the serving cell nTTI, e.g., when the scheduling information for the sTTI may be available.

[0327] For example, scheduling information may be available or considered available when the WTRU can have scheduling information for an sTTI at least some amount of time before the start of the nTTI, which may be sufficient time to use the scheduling information.

[0328] The amount of time may be a number of sTTIs, e.g., an UL sTTI or a DL sTTI, a number of symbols, and / or a number of time samples. The amount of time may be fixed or configurable. The amount of time may be WTRU-specific. The amount of time may be a function of a timing advance, e.g., an applied timing advance, and / or a receive-transmit (Rx-Tx) time difference, e.g., with respect to the serving cell. The Rx-Tx time difference may be the time difference between the receive timing and transmit timing of the WTRU.

[0329] In one example, the WTRU Rx-Tx time difference may be defined as TUE_RX-TUE_TX. TUE_RX may be defined by the first detected path in time, e.g., the WTRU receive timing of downlink time unit (e.g., subframe or radio frame) #i from the serving cell. TUE_TX may be the WTRU transmit timing of uplink time unit (e.g., subframe or radio frame) #i. The reference point for the WTRU Rx-Tx time difference measurement may be the WTRU antenna connector.

[0330] The nTTI PH may use one sTTI from the set of sTTIs. For nTTIs that may overlap in the set of sTTIs, for example, the calculation and / or determination of power, maximum power, and / or PH may use at least one or only one of the set of sTTIs.

[0331] The calculation and / or determination may, for example, use an sTTI from among a set of sTTIs, where the sTTI may be an sTTI for which the WTRU may have scheduling information (e.g., available scheduling information), an sTTI with the most RBs scheduled, a sTTI with the largest maximum power reduction tolerance, e.g., maximum power, e.g., P CMAX,c sTTI, e.g., a maximum power, e.g., P, that can result in, e.g., a maximum MPR and / or a maximum additional MPR (A-MPR), for use in determining CMAX,c The sTTI may be at least one of the sTTI that can result in the largest maximum power reduction tolerance, which may relate to the placement of scheduled resources for use in determining, for example, being near or not near a band edge, and / or the sTTI that can result in the lowest maximum power for the PH calculation, which may be, for example, an nTTI PH calculation.

[0332] The WTRU may include at least one of the following in the PHR, e.g., a PHR that may be transmitted in nTTIs: an sTTI PH for an sTTI or for an sTTI in a set of sTTIs that the WTRU can use in determining the power, maximum power, and / or PH for the nTTI transmission; and / or an indication of an sTTI, which may be an sTTI in a set of sTTIs that the WTRU can use to determine the power, maximum power, and / or PH that may be reported in the PHR.

[0333] Scheduling information availability may depend on at least one of the TTI length, e.g., sTTI length, e.g., UL sTTI length and / or DL ​​sTTI length, and nTTI length, e.g., UL nTTI length and / or DL ​​nTTI length. Scheduling information availability may be a function of the time between the TTI that schedules or causes a transmission and the TTI in which the transmission may occur.

[0334] Some scheduling information may not be available for a first TTI, eg, sTTI, that may overlap with a second TTI, eg, nTTI.

[0335] In a non-limiting example, a WTRU may be configured with nTTIs for a first cell (cell 1) and sTTIs for a second cell (cell 2). The sTTIs may overlap with one nTTI, and the nTTIs may overlap with M sTTIs. The WTRU may receive scheduling information for N of the M sTTIs, or may only receive such scheduling information, within a sufficient time, e.g., a threshold amount of time, before the start of the nTTI to be able to use that information for, e.g., power, max power, and / or PH calculations and / or determinations, where the calculations and / or determinations may be for nTTIs.

[0336] For example, scheduling information can be received several TTIs prior to transmission. In a non-limiting example, the number may be four. Referring to sTTI3 in the example in FIG. 20, seven sTTIs overlap with n TTIs. When scheduling information is received four sTTIs prior to transmission, scheduling for transmission in the fifth sTTI will be received in the first sTTI. Scheduling information for the fifth sTTI may be received after the start of transmission for n TTIs and may not be available or usable, for example, for calculation and / or determination for n TTIs. In this example, N may be four or less.

[0337] The sTTI PH may use sTTI scheduling. The calculation and / or determination of the sTTI PH and one or more associated values ​​may use scheduling information for the sTTI. For a serving cell (e.g., a first serving cell) sTTI, the WTRU may determine the power (e.g., for a channel such as a physical channel of the serving cell), the maximum power (e.g., for the serving cell), and / or the PH based on the scheduled transmission for the serving cell sTTI (e.g., a parameter of the scheduled transmission, such as a number of RBs for the scheduled transmission).

[0338] The WTRU may determine the maximum power based at least on scheduled transmissions for another serving cell (e.g., a second serving cell) sTTI, e.g., an in-band serving cell sTTI, which may overlap the serving cell sTTI completely or at least by a fixed or configured amount.

[0339] The sTTI PH may use nTTI scheduling. The calculation and / or determination of the sTTI PH and one or more associated values ​​may use scheduling information for overlapping nTTIs, for example, when the scheduling information may be available. For sTTIs that may be overlapped by one nTTI, scheduling information for the nTTI may be available or may always be available.

[0340] For a serving cell sTTI, e.g., a first serving cell sTTI, the WTRU may determine the power for a channel, e.g., a physical channel of the serving cell, e.g., the maximum power for the serving cell, and / or PH, based on scheduled transmissions for nTTI of the serving cell (and / or another, e.g., second serving cell) that may overlap with the serving cell sTTI, e.g., when scheduling information for nTTI may be available. Scheduling information may be available, or considered available, when the WTRU may have scheduling information for nTTI at least some amount of time before the start of the sTTI, which may be sufficient time to use the scheduling information.

[0341] The configuration may be provided, for example, by a base station. The configuration may be received and / or used, for example, by a WTRU. The WTRU may be configured with and / or use nTTIs and / or sTTIs, for example, in the same or different serving cells. The WTRU may be able to and / or configured to report PH in or for nTTIs, only in or for nTTIs, and / or in or for sTTIs. The WTRU may report PH in or for sTTIs, for example, only when configured or configured to report PH in or for sTTIs.

[0342] Several exemplary PH reporting examples are disclosed herein: In one example, a Cell 1n TTI with a trigger overlaps with a Cell 2s TTI.

[0343] In one example of PH reporting, the WTRU may be triggered for PHR (e.g., the WTRU may determine that PH may be triggered) in or for n TTIs, e.g., for a first cell (e.g., a first serving cell). The WTRU may have resources granted, allocated, and / or available for n PUSCH in the first cell, e.g., for n TTIs. The grant or allocation may be for new data. The WTRU may determine the n TTI PH, e.g., for the first cell.

[0344] The WTRU may, for example, determine whether it may have at least one sTTI in the second cell (e.g., the second serving cell) that may overlap with the nTTI. The WTRU may, for example, determine an sTTI PH (e.g., at least one or only one sTTI PH) when the WTRU may have (e.g., when the WTRU may determine that it may have) at least one overlapping sTTI in the second cell (e.g., the second serving cell). The WTRU may, for example, determine an sTTI PH for the second cell.

[0345] The WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH, e.g., on the nPUSCH. The WTRU may send a MAC-CE, which may include the nTTI PH and / or the sTTI PH, e.g., on the nPUSCH.

[0346] The reported PH may be real or virtual. The reported nTTI PH may be, for example, a Type B PH or a Type C PH. The reported sTTI PH may be, for example, a Type A PH or a Type C PH. For transmissions that may include control channels, e.g., nPUCCH and / or sPUCCH, one or more of Types D, E, and / or F may be determined, reported, and / or used. As used herein, the terms send, transmit, and report may be used interchangeably in examples and embodiments.

[0347] 21 is an example of a PH report 2100. The illustrated steps may be performed in a different order. In example 2100, a WTRU may be triggered for a PHR in or for n TTIs, e.g., for a first cell (e.g., a first serving cell) (e.g., the WTRU may determine that a PHR may be triggered) 2102. The WTRU may determine whether it has resources granted, allocated, and / or available for nPUSCH (e.g., for n TTIs), e.g., in the first cell 2104. The WTRU may further determine whether nPUSCH resources may be used for PH transmission or reporting. If the WTRU determines 2104 that it has nPUSCH resources that may be used for PH transmission or reporting in or for nTTIs, the WTRU may determine whether there are or whether it has overlapping sTTIs, for example for a second cell (e.g., a second serving cell) 2106. If the WTRU determines 2106 that there are or it has overlapping sTTIs, the WTRU may determine at least one overlapping sTTI at 2108 and an sTTI PH for the at least one determined overlapping sTTI at 2110. The WTRU may determine the nTTI PH at 2112 and may transmit or report the determined PH at 2114. The PH reporting procedure may terminate and / or restart for the next TTI at 2116. If there is no PHR trigger for n TTI, the WTRU may not transmit a PH and the procedure may end or the WTRU may wait for the next TTI, at 2116. If the WTRU determines, at 2104, that there are no n PUSCH resources in the n TTI that may be used to transmit or report a PH in the n TTI, the procedure may end or the WTRU may wait for the next TTI, at 2116.If, in 2106 , the WTRU determines that there are no overlapping sTTIs or that it does not have overlapping sTTIs, the WTRU may determine nTTI PH in 2112 and may proceed to steps 2114 and 2116 .

[0348] In one example, cell 1 n TTI with the trigger overlaps with cell 2 s TTI. In one example of PH reporting, the WTRU may be triggered for PHR in or for n TTI, for example, for a first cell (e.g., a first serving cell) (e.g., the WTRU may determine that PH may be triggered). The WTRU may have resources granted, allocated, and / or available for n PUSCH (e.g., for n TTI) in the first cell. The grant or allocation may be for new data. The WTRU may determine the power for n PUSCH.

[0349] The WTRU may have or may also have scheduling information, grants, and / or allocations for short or sTTI channels (e.g., channels for sTTI) in a second cell (e.g., a second serving cell). sPUSCH is used as a non-limiting example of an sTTI channel. Another channel, such as sPUCCH, may be used.

[0350] An sTTI channel, e.g., an sPUSCH, may fully or at least partially overlap with an nPUSCH. For example, resources (e.g., in time) for an sTTI channel and / or transmissions of the sTTI channel may overlap with resources (e.g., in time) for an nPUSCH and / or transmissions of the nPUSCH. An sTTI may overlap (e.g., fully or at least partially) with an nTTI (e.g., the nTTI for which a PHR may be triggered). The WTRU may determine the sTTI channel (e.g., sPUSCH) power.

[0351] The WTRU may determine at least one maximum power. For example, the WTRU may determine a maximum power for the first cell and / or the second cell. The WTRU may determine a maximum power for the first cell and the second cell, e.g., P CMAX,c The WTRU may determine a maximum power for the first cell, e.g., P CMAX,c 1, and the maximum power for the second serving cell, e.g., P CMAX,c You may decide 2. P CMAX,c 1 and P CMAX,c 2 may be the same. For example, when the first and second cells may be different cells, which may be inter-band cells and / or non-adjacent (e.g., non-adjacent intra-band) cells, P CMAX,c 1 and P CMAX,c The two can be different.

[0352] The WTRU may, for example, determine nTTI PH (eg, for nPUSCH) for a first serving cell. The WTRU may, for example, determine sTTI PH (eg, for sPUSCH) for a second serving cell.

[0353] nTTI PH is P CMAX,c , or P CMAX,c 1 - determined nPUSCH power. CMAX,c , or P CMAX,c 2-Determined sPUSCH Power: nTTI PH or sTTI PH may be determined based on the nPUSCH power and / or the sPUSCH power.

[0354] The WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH, e.g., on the nPUSCH. The WTRU may send a MAC-CE, which may include the nTTI PH and / or the sTTI PH, e.g., on the nPUSCH. CMAX,c The WTRU may include P CMAX,c 1 and / or P CMAX,c 2 may be included in the PHR.

[0355] The reported nTTI PH may be, for example, a Type B PH or a Type C PH. The reported sTTI PH may be, for example, a Type A PH or a Type C PH. For transmissions that may include a control channel (e.g., nPUCCH and / or sPUCCH), one or more of Types D, E, and / or F may be determined, reported, and / or used.

[0356] Alternatively, the WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH, for example, on an sPUSCH, which may overlap with the nPUSCH.

[0357] In one example, cell 1 n TTIs with a trigger overlap M cell 2 s TTIs. In another example of PH reporting, the WTRU may be triggered for PHR in or for n TTIs, for example, for a first cell (e.g., a first serving cell) (e.g., the WTRU may determine that PH may be triggered). The WTRU may have resources granted, allocated, and / or available for n PUSCH (e.g., for n TTIs) in the first cell. The grant or allocation may be for new data. The WTRU may determine the power for n PUSCH.

[0358] For example, the M sTTIs on or for the second cell may, for example, fully or at least partially overlap with the nTTIs on or for the first cell, for example, the nTTIs for which a PHR may be triggered.

[0359] The WTRU may, e.g., also have scheduling information, grants, and / or allocations for at least one sTTI channel in the N sTTIs or each of the N sTTIs in the second cell (e.g., second serving cell). The N sTTIs may be a subset of the M sTTIs that may overlap with the nTTI. The N sTTIs may overlap (e.g., fully or at least partially) with the nTTI. One or more (e.g., all) of the sTTI channels in the N sTTIs may overlap with the nPUSCH.

[0360] The overlap may be complete or at least partial. One or more of the sTTI channels may be an sPUSCH. One or more of the sTTI channels may be an sPUCCH. The WTRU may determine or select at least one of the M sTTIs to use for at least PH reporting. The WTRU may determine at least one of the N sTTIs to use for at least PH reporting. The determined sTTI may be the kth sTTI among the M sTTIs.

[0361] The determined sTTI may be, for example, at least one of an sTTI determined according to a WTRU implementation, an sTTI for which the WTRU may have scheduling information for an sPUSCH, an sTTI for which the WTRU may have scheduling information for an sPUCCH, the first, e.g., earliest in time, sTTI among N or M sTTIs for which the WTRU may have scheduling information for an sPUSCH or an sPUCCH, an sTTI among N or M sTTIs for which the power reduction tolerance (e.g., at least one of MPR, A-MPR, P-MPR, etc., or a combination thereof) may be the largest, an sTTI among N or M sTTIs for which the maximum power may be the smallest, and / or, for example, the first (e.g., earliest in time) sTTI among M sTTIs regardless of whether the WTRU may have scheduling information for the sTTI (e.g., for an sPUSCH or sPUCCH).

[0362] The WTRU may determine an sTTI channel, e.g., an sPUSCH, to use for at least PH reporting, e.g., by selecting from among the sTTI channels among the N sTTIs. The determined sTTI channel may correspond to the kth sTTI among the M sTTIs.

[0363] The determined sTTI channel may be, for example, at least one of an sTTI channel determined according to a WTRU implementation, an sPUSCH or an sPUCCH, for example, an sPUSCH or sPUCCH for which the WTRU may have scheduling information, the first, e.g., earliest sPUSCH in time, among the sPUSCHs for which the WTRU may have scheduling information, the first, e.g., earliest sPUCCH in time, among the sPUCCHs for which the WTRU may have scheduling information, an sTTI channel among the sTTI channels for which the power reduction tolerance (e.g., at least one of MPR, A-MPR, P-MPR, etc., or a combination thereof) may be the largest, and / or an sTTI channel among the sTTI channels for which the maximum power may be the smallest.

[0364] The WTRU may determine a power for the determined sTTI channel. The WTRU may determine a power for the sTTI channel in the determined sTTI. The WTRU may determine at least one maximum power. For example, the WTRU may determine a maximum power for the first cell and / or the second cell. The WTRU may, for example, determine nTTI PH for nPUSCH. nTTI PH may be determined by P CMAX,c , or P CMAX,c 1 - may be the determined nPUSCH power.

[0365] The WTRU may, for example, determine an sTTI PH for the determined or selected sTTI channel. The WTRU may, for example, determine an sTTI PH for the determined or selected sTTI based on the determined power for one or more sTTI channels within the determined or selected sTTI.

[0366] sTTI PH is P CMAX,c , or P CMAX,c 2-It may be the determined power of at least one sTTI channel.

[0367] The WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH, e.g., on the nPUSCH. The WTRU may send a MAC-CE, which may include the nTTI PH and / or the sTTI PH, e.g., on the nPUSCH. CMAX,c The WTRU may include P CMAX,c 1 and / or P CMAX,c 2 may be included in the PHR.

[0368] Alternatively, the WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH, for example, on an sPUSCH, which may overlap with the nPUSCH.

[0369] The WTRU may include an indication in the PHR to indicate which sTTI or sTTI channel (e.g., sPUSCH and / or sPUCCH) the sTTI PH can correspond to. For example, the WTRU may include an indication that the sTTI PH can correspond to the kth sTTI out of M sTTIs that may overlap with nTTIs. For example, the WTRU may include a value of k or k-1.

[0370] A number of bits (B) may be used for indication. The value of B may be fixed or configurable. B may be, for example, 1, 2, or 3. B may be a function of the sTTI length and / or nTTI length. For example, for nTTI as 1 subframe or 14 symbols, B may be 1 for sTTI as 1 timeslot or 7 symbols, B may be 1 or 2 for sTTI as 4 symbols, and / or B may be 2 or 3 for sTTI as 2 symbols.

[0371] Alternatively, the WTRU may determine an sTTI PH for at least one (e.g., each) of the M sTTIs that may overlap the nTTI. The determined sTTI PH may be real or virtual. The WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH (e.g., M sTTI PH), for example, on the nPUSCH (or an sPUSCH that may overlap the nPUSCH).

[0372] In one example, cell 1 sTTI with a trigger overlaps cell 2 nTTI. In one example of PH reporting, the WTRU may be triggered for PHR (e.g., the WTRU may determine that PH may be triggered) within or for the sTTI, for example, for a first cell (e.g., a first serving cell). The WTRU may have resources granted, allocated, and / or available for the sPUSCH (e.g., for the sTTI) in the first cell. The grant or allocation may be for new data. The WTRU may determine the power for the sPUSCH.

[0373] The WTRU may use and / or be configured, or may use and / or be configured, for operation with nTTI in the second cell. The sTTI may overlap completely or at least partially with the nTTI.

[0374] The WTRU may, for example, determine an sTTI PH for an sPUSCH. The WTRU may, for example, determine an nTTI PH for an nTTI that may overlap an sTTI.

[0375] The WTRU may determine a realistic nTTI, e.g., when the sPUSCH may overlap with an nPUSCH for which resources may be granted or allocated. The WTRU may determine a virtual nTTI PH, e.g., when the sPUSCH may not overlap with an nPUSCH.

[0376] The WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH, e.g., on an sPUSCH. The WTRU may send a MAC-CE, which may include the nTTI PH and / or the sTTI PH, e.g., on an sPUSCH. The WTRU may determine one or more maximum powers, e.g., P CMAX,c , P CMAX,c 1, and / or P CMAX,c At least one of the two can be included in the PHR.

[0377] Alternatively, the WTRU may send, transmit, include, or report the determined nTTI PH and / or the determined sTTI PH on the nPUSCH, for example, when the PHR trigger may be before the start of the nTTI (e.g., within a sufficient time before that).

[0378] Figure 22 is an example of sPDCCH region determination 2200. A WTRU may monitor a short TTI PDCCH (sPDCCH) region 2202. The WTRU may perform monitoring when the downlink sTTI length is configured to be shorter than the uplink sTTI length. The WTRU may determine an sPDCCH region from among a set of candidate sPDCCH regions for an uplink grant based on WTRU-specific parameters 2204. The WTRU-specific parameters may include a WTRU-ID. An uplink grant may be received by the WTRU in the determined sPDCCH region 2206. The WTRU may communicate within the network using the uplink grant 2208.

[0379] 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 may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by 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 memory 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 in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. a processor; A transceiver; 1. A wireless transmit / receive unit (WTRU) comprising: the processor and the transceiver are configured to receive configuration information for transmitting a power headroom (PH) report comprising PH information for a plurality of cells, a first cell of the plurality of cells being associated with a first time interval of a first length and a second cell of the plurality of cells being associated with a second time interval of a second length, the first length being greater than the second length; the transceiver is configured to transmit a first uplink transmission using a first carrier frequency associated with the first cell during one of the first time intervals; the processor and the transceiver are configured to transmit the PH report, and based on the configuration information, the PH report includes first PH information of the first cell corresponding to one of the first time intervals and second PH information of the second cell corresponding to an earliest one of the second time intervals that completely overlaps one of the first time intervals. WTRU.

2. 10. The WTRU of claim 1, wherein the PH report is transmitted in one of the first time intervals using the first carrier frequency.

3. 10. The WTRU of claim 1, wherein the PH report is transmitted in a second uplink transmission using a second carrier frequency associated with the second cell.

4. 2. The WTRU of claim 1, wherein the first length is 1 millisecond (ms) and the second length is 0.5 ms.

5. 2. The WTRU of claim 1, wherein the first cell is associated with a first base station using a first radio access technology (RAT) and the second cell is associated with a second base station using a second RAT.

6. The WTRU of claim 1 , wherein the PH report including the first PH information and the second PH information is included in the first uplink transmission.

7. The WTRU of claim 1 , wherein the PH report is a Type 1 PH report.

8. 2. The WTRU of claim 1, wherein the first PH information and the second PH information are determined based on a calculated transmit power for the first uplink transmission and based on a calculated PH for a reference format associated with a second carrier frequency, the second carrier frequency being associated with the second cell.

9. 2. The WTRU of claim 1, wherein the first PH information includes an indication of a maximum transmit power associated with the first carrier frequency and a PH indicating a difference between the maximum transmit power and a calculated transmit power determined independently of the maximum transmit power.

10. 10. The WTRU of claim 9, wherein the maximum transmit power associated with the first carrier frequency is one of a plurality of maximum transmit powers configured for carrier frequencies associated with the first cell.

11. 1. A method performed by a wireless transmit / receive unit (WTRU), comprising: receiving configuration information for transmitting a power headroom (PH) report comprising PH information for a plurality of cells, wherein a first cell of the plurality of cells is associated with a first time interval of a first length and a second cell of the plurality of cells is associated with a second time interval of a second length, the first length being greater than the second length; transmitting a first uplink transmission using a first carrier frequency associated with the first cell during one of the first time intervals; transmitting the PH report, wherein based on the configuration information, the PH report includes first PH information of the first cell corresponding to one of the first time intervals and second PH information of the second cell corresponding to an earliest one of the second time intervals that completely overlaps one of the first time intervals; A method for providing

12. The method of claim 11 , wherein the PH report is transmitted during one of the first time intervals using the first carrier frequency.

13. 12. The method of claim 11, wherein the PH report is transmitted in a second uplink transmission using a second carrier frequency associated with the second cell.

14. 12. The method of claim 11, wherein the first length is 1 millisecond (ms) and the second length is 0.5 ms.

15. 12. The method of claim 11, wherein the first cell is associated with a first base station using a first radio access technology (RAT) and the second cell is associated with a second base station using a second RAT.

16. The method of claim 11 , wherein the PH report including the first PH information and the second PH information is included in the first uplink transmission.

17. The method of claim 11 , wherein the PH report is a Type 1 PH report.

18. 12. The method of claim 11, wherein the first PH information and the second PH information are determined based on a calculated transmit power for the first uplink transmission and based on a calculated PH for a reference format associated with a second carrier frequency, the second carrier frequency being associated with the second cell, respectively.

19. 12. The method of claim 11, wherein the first PH information includes an indication of a maximum transmit power associated with the first carrier frequency and a PH indicating a difference between the maximum transmit power and a calculated transmit power determined independently of the maximum transmit power.

20. 20. The method of claim 19, wherein the maximum transmit power associated with the first carrier frequency is one of a plurality of maximum transmit powers configured for carrier frequencies associated with the first cell.

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