Access and link adaptation method for coverage-extended wireless transmissions - Patents.com

Abstract

To provide a novel system and method related to coverage enhancement for channels in a wireless communication system such as LTE / LTE-A.SOLUTION: Service data is transmitted in a wireless communication system. Coverage enhancement of channels of a cell of a system in a wireless communication system such as Long Term Evolution (LTE) and LTE-Advanced (LTE-A) is provided. Coverage enhancement may include repetition of a channel in a time and / or frequency domain, power boosting of the channel, and reference signal improvement for better channel estimation accuracy. Link adaptation techniques are described and the link adaptation is dependent on a coverage enhancement (CE) or repetition level.SELECTED DRAWING: Figure 2

Description

[Background technology]

[0001] The present invention relates to wireless communications. Summary of the Invention

[0002] (CROSS REFERENCE TO RELATED APPLICATIONS) This application is a nonprovisional application of and claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 61 / 933,300, filed January 29, 2014, U.S. Provisional Application No. 61 / 955,655, filed March 19, 2014, and U.S. Provisional Application No. 62 / 075,630, filed November 5, 2014, the contents of which are incorporated herein by reference in their entireties.

[0003] In Third Generation Partnership (3GPP) Long Term Evolution (LTE) Advanced, coverage extension techniques are being investigated to support wireless transmit / receive units (WTRUs) that may be deployed in areas with limited coverage. [Problem to be solved by the invention]

[0004] Such WTRUs may operate in areas with limited coverage, with delay tolerance, reduced functionality, or limited services. Examples include low-cost or low-complexity machine type communication (LC-MTC) WTRUs such as smart meters or sensors that may be deployed in the basement of a residence where very high penetration losses are expected. [Means for solving the problem]

[0005] Described herein are systems and methods related to coverage extension for channels in wireless communication systems such as LTE / LTE-A. Coverage extension may include channel repetition in time and / or frequency domain, channel power boost, and reference signal improvement for better channel estimation accuracy. In representative embodiments described herein, link adaptation for communication with a wireless transmit / receive unit (WTRU) is based on a coverage extension level or a channel repetition level. Link adaptation techniques are described herein for uplink and downlink channels, including data, control, access, and broadcast channels.

[0006] In an example embodiment, the WTRU may determine a number of repetitions for an uplink channel, derive a transmit power for the uplink channel based on the determined number of repetitions, and transmit the uplink channel at the derived transmit power level with the determined number of repetitions. The WTRU may determine the number of repetitions from at least one of a determined coverage extension (CE) level, a downlink measurement, a random access procedure, and an indication from the network.

[0007] Further described herein are systems and methods for extending UE battery life in coverage extension (CE) mode. In particular, channel-dependent CE level configurations can be used to optimize the number of iterations. Furthermore, (E)PDCCH monitoring in CE mode can be minimized using time window-based transmission.

[0008] A more detailed understanding may be had from the following description, presented by way of example in conjunction with the accompanying drawings, in which: Figures in such drawings, as well as the detailed description, are examples; thus, the figures and detailed description should not be considered limiting, as other equally effective examples are possible and anticipated. Moreover, like reference numerals in the figures refer to like elements. Effect of the Invention

[0009] Systems and methods related to coverage extension for channels in wireless communication systems such as LTE / LTE-A are disclosed. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 1 illustrates an example communication system in which the disclosed embodiments may be implemented. [Figure 1B] FIG. 1B is a system diagram of an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A. [Figure 1C] FIG. 1B is a system diagram of an example radio access network (RAN) and core network that may be used within the communication system of FIG. 1A. [Figure 1D] FIG. 1B is a system diagram of another example RAN and core network that may be used within the communications system of FIG. 1A. [Figure 1E] FIG. 1B is a system diagram of another example RAN and core network that may be used within the communications system of FIG. 1A. [Figure 1F] FIG. 1B is a system diagram illustrating example network entities that may be used within the communication system of FIG. 1A. [Diagram 2] FIG. 1 is a diagram of an example of contention based on a random access (RA) procedure. [Diagram 3] FIG. 1 is a diagram showing an example of a Physical Random Access Channel (PRACH) window according to a CE level. [Figure 4] FIG. 1 illustrates an example of PRACH resource frequency division multiplexing (FDM) between normal mode and CE mode. [Diagram 5] FIG. 1 illustrates an example of PRACH resource code division multiplexing (CDM) between normal mode and CE mode. [Figure 6] FIG. 1 is a flow diagram of a method for setting a repetition level according to some embodiments. [Figure 7]FIG. 1 is a flow diagram of a method for setting a repetition level according to some embodiments. [Figure 8] A diagram showing a method of indicating the starting subframe of a PDSCH window and a PUSCH window using a downlink (DL) offset and an uplink (UL) offset. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A detailed description of exemplary embodiments will now be provided with reference to various figures. However, while the present invention may be described in connection with the representative embodiments, it is not limited thereto, and other embodiments may be used, or modifications or additions may be made to the detailed embodiments, to perform the same functions of the present invention without departing from the present invention. Although the representative embodiments are generally illustrated below using a wireless network architecture, any number of different network architectures may be used, including, for example, networks having wired and / or wireless components.

[0012] 1A illustrates 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 the 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), Single Carrier FDMA (SC-FDMA), etc.

[0013] 1A, the communications system 100 may include WTRUs 102a, 102b, 102c, and / or 102d (which may be referred to generally or collectively as WTRUs 102), a RAN 103 / 104 / 105, a core network 106 / 107 / 109, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, consumer electronics devices, etc. The WTRUs 102a, 102b, 102c and / or 102d may also be referred to as UEs.

[0014] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNodeB, a home NodeB, a home eNodeB, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each shown as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0015] The base station 114a may be part of the RAN 103 / 104 / 105, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals within a particular geographic area, sometimes referred to as a cell (not shown). The cell may be further divided into sectors, e.g., 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 transceiver 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.

[0016] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 115 / 116 / 117, which may be any suitable wireless communications link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 115 / 116 / 117 may be established using any suitable radio access technology (RAT).

[0017] More specifically, as discussed above, the communication 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 103 / 104 / 105 and the WTRUs 102a, 102b, 102c may implement a radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using Wideband CDMA (WCDMA). WCDMA may include communication protocols, such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0018] In another embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 115 / 116 / 117 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A).

[0019] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Global 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.

[0020] The base station 114b of FIG. 1A may be, by way of example, a wireless router, a home NodeB, a home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as a workplace, a home, a vehicle, and a campus. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.11, to establish a wireless local area network (WLAN). In another embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.15, to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not be required to access the Internet 110 via the core network 106 / 107 / 109.

[0021] The RAN 103 / 104 / 105 may communicate with the core network 106 / 107 / 109, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. By way of example, the core network 106 / 107 / 109 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A, it will be understood that the RAN 103 / 104 / 105 and / or the core network 106 / 107 / 109 may communicate directly or indirectly with other RANs employing the same RAT as the RAN 103 / 104 / 105 or a different RAT. For example, in addition to being connected to the RAN 103 / 104 / 105 that can utilize E-UTRA radio technology, the core network 106 / 107 / 109 may communicate with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, or WiFi radio technology.

[0022] The core network 106 / 107 / 109 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) in the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another core network connected to one or more RANs, which may employ the same RAT or a different RAT as the RANs 103 / 104 / 105.

[0023] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities, e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based radio technology, and a base station 114b, which may employ an IEEE 802 radio technology. Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may communicate with other devices using Bluetooth technology.

[0024] FIG. 1B is a system diagram illustrating 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, a non-removable memory 130, a removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138. The transceiver 120 may be implemented as a component of a decoder logic 119. For example, the transceiver 120 and the decoder logic 119 may be implemented on a single LTE or LTE-A chip. The decoder logic may include a processor operative to execute instructions that may be stored on a non-transitory computer-readable medium. Alternatively or additionally, the decoder logic may be implemented using custom and / or programmable digital logic circuitry.

[0025] It will be understood that the WTRU 102 may include any sub-combination of the above elements while remaining consistent with an embodiment. Also, it will be understood that embodiments contemplate that the base stations 114a and 114b and / or nodes that the base stations 114a and 114b may represent, such as, but not limited to, a transceiver station (BTS), a Node-B, a site controller, an access point (AP), a Home Node-B, an evolved Home Node-B (eNodeB), a Home Evolved Node-B (HeNB), a Home Evolved Node-B Gateway, a proxy node, etc., among others, may include some or all of the elements shown in FIG. 1B and described herein.

[0026] 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 in association 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, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0027] The transmit / receive element 122 may be configured to transmit signals to and / or receive signals from a base station (e.g., base station 114a) over the air interface 115 / 116 / 117. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In another embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, by way of example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals. It is contemplated that the terms signal and channel may be used interchangeably.

[0028] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, 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) that transmit and / or receive wireless signals over the air interface 115 / 116 / 117.

[0029] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and / or 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, by way of example, UTRA and IEEE 802.11.

[0030] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a 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, or the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0031] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components within the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. By way of example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0032] 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 a current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 115 / 116 / 117 from a base station (e.g., base stations 114a, 114b) and / or may determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information using any suitable location determination method while remaining consistent with an embodiment.

[0033] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos or videos), a Universal Serial Bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, etc.

[0034] 1C is a system diagram illustrating the RAN 103 and the core network 106 according to an embodiment. As described above, the RAN 103 may employ UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 115. The RAN 103 may also communicate with the core network 106. As shown in FIG. 1C, the RAN 103 may include Node-Bs 140a, 140b, 140c, each of which may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 115. The Node-Bs 140a, 140b, 140c may each be associated with a particular cell (not shown) within the RAN 103. The RAN 103 may also include RNCs 142a, 142b. It will be appreciated that the RAN 103 may include any number of Node-Bs and RNCs while remaining consistent with an embodiment.

[0035] As shown in FIG. 1C, the Node-Bs 140a, 140b can communicate with the RNC 142a. Additionally, the Node-Bs 140c can communicate with the RNC 142b. The Node-Bs 140a, 140b, 140c can communicate with their respective 142a, 142b via an Iub interface. The RNCs 142a, 142b can communicate with each other via an Iur interface. Each of the RNCs 142a, 142b can be configured to control the respective Node-Bs 140a, 140b, 140c to which it is connected. Additionally, each of the RNCs 142a, 142b can be configured to perform or support other functionalities, such as outer loop power control, load control, admission control, packet scheduling, handover control, macro diversity, security functions, data encryption, and the like.

[0036] 1C may include a Media Gateway (MGW) 144, a Mobile Switching Center (MSC) 146, a Serving GPRS Support Node (SGSN) 148, and / or a Gateway GPRS Support Node (GGSN) 150. 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 and / or operated by an entity different from the core network operator.

[0037] The RNC 142a in the RAN 103 may be connected to an MSC 146 in the core network 106 via an IuCS interface. The MSC 146 may be connected to the MGW 144. The MSC 146 and MGW 144 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices.

[0038] The RNC 142a in the RAN 103 may also be connected to an SGSN 148 in the core network 106 via an IuPS interface. The SGSN 148 may be connected to a GGSN 150. The SGSN 148 and GGSN 150 may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0039] As mentioned above, the core network 106 may also be connected to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0040] 1D is a system diagram illustrating the RAN 104 and the core network 107 according to an embodiment. As discussed above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the core network 107.

[0041] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a, for example, may use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0042] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, and scheduling of users on the uplink and / or downlink, etc. As shown in FIG 1D, the eNodeBs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0043] The core network 107 shown in Figure 1D may include a mobility management gateway (MME) 162, a serving gateway 164, and a packet data network (PDN) gateway (PGW) 166. Although each of the above elements is shown as part of the core network 107, it will be understood that any of these elements may be owned and / or operated by an entity different from the core network operator.

[0044] The MME 162 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 162 may be responsible for authentication of users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selection of a particular serving gateway upon initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 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 and / or WCDMA.

[0045] The serving gateway 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The serving gateway 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The serving gateway 164 may also perform other functions, such as anchoring the user plane during inter-eNodeB handover, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, etc.

[0046] The serving gateway 164 may be connected to a PDN gateway 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0047] The core network 107 may facilitate communications with other networks. For example, the core network 107 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the core network 107 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 107 and the PSTN 108. In addition, the core network 107 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0048] 1E is a system diagram illustrating the RAN 105 and the core network 109 according to an embodiment. The RAN 105 may be an Access Service Network (ASN) that employs IEEE 802.16 wireless technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 117. As described further below, communication links between different functional entities of the WTRUs 102a, 102b, 102c, the RAN 105, and the core network 109 may be defined as reference points.

[0049] 1E, the RAN 105 may include base stations 180a, 180b, 180c and an ASN gateway 182, although it will be understood that the RAN 105 may include any number of base stations and ASN gateways while remaining consistent with an embodiment. The base stations 180a, 180b, 180c may each be associated with a particular cell (not shown) in the RAN 105 and each may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 117. In one embodiment, the base stations 180a, 180b, 180c may implement MIMO technology. The base station 180a, for example, may use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a. The base stations 180a, 180b, 180c may also provide mobility management functions such as handoff triggering, tunnel establishment, radio resource management, traffic classification, quality of service (QoS) policy enforcement, etc. The ASN gateway 182 may act as a traffic aggregation point and may be responsible for paging, caching of subscriber profiles, routing to the core network 109, etc.

[0050] The air interface 117 between the WTRUs 102a, 102b, 102c and the RAN 105 may be defined as an R1 reference point that implements the IEEE 802.16 specification. In addition, each of the WTRUs 102a, 102b, 102c may establish a logical interface (not shown) with the core network 109. The logical interface between the WTRUs 102a, 102b, 102c and the core network 109 may be defined as an R2 reference point that may be used for authentication, authorization, IP host configuration management, and / or mobility management.

[0051] The communication link between each of the base stations 180a, 180b, 180c may be defined as an R8 reference point that includes protocols for facilitating WTRU handovers and the transfer of data between base stations. The communication link between the base stations 180a, 180b, 180c and the ASN gateway 182 may be defined as an R6 reference point. The R6 reference point may include protocols for facilitating mobility management based on mobility events associated with each of the WTRUs 102a, 102b, 102c.

[0052] As shown in Figure IE, the RAN 105 may be connected to a core network 109. The communication link between the RAN 105 and the core network 109 may be defined as an R3 reference point, including protocols for facilitating data forwarding functions, mobility management functions, by way of example. The core network 109 may include a Mobile IP Home Agent (MIP-HA) 184, an Authentication, Authorization, and Accounting (AAA) server 186, and a gateway 188. Although each of the above elements is shown as part of the core network 109, it will be understood that any of these elements may be owned and / or operated by an entity different from the core network operator.

[0053] The MIP-HA may be responsible for IP address management and may enable the WTRUs 102a, 102b, 102c to roam between different ASNs and / or different core networks. The MIP-HA 184 may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The AAA server 186 may be responsible for user authentication and support of user services. The gateway 188 may facilitate interworking with other networks. For example, the gateway 188 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. The gateway 188 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0054] Although not shown in FIG. 1E, it will be understood that the RAN 105 may be connected to other ASNs, and the other RANs (e.g., RANs 103 and / or 104) and / or the core network 109 may be connected to other core networks (e.g., core networks 106 and / or 107). The communication link between the RAN 105 and the other ASNs may be defined as an R4 reference point (not shown), which may include protocols for coordinating mobility of the WTRUs 102a, 102b, 102c between the RAN 105 and the other ASNs. The communication link between the core network 109 and the other core networks may be defined as an R5 reference point (not shown), which may include protocols for facilitating interoperation between a home core network and a visited core network.

[0055] Figure 1F is a system diagram illustrating an example network entity 190 that may be used within the communication system 100 of Figure 1A. As shown in Figure 1F, the network entity 190 may include a communication interface 192, a processor 194, and / or non-transitory data storage 196, which may be communicatively linked by a bus, network, or other communication path 198.

[0056] The communication interface 192 may include one or more wired communication interfaces and / or one or more wireless communication interfaces. For wired communication, the communication interface 192 may include one or more interfaces, such as an Ethernet interface, as an example. For wireless communication, the communication interface 192 may include components, such as one or more antennas, one or more transceivers and / or chipsets, that may be designed and / or configured for one or more types of wireless (e.g., LTE) communication, and / or any other components that may be deemed appropriate by those skilled in the relevant art. For wireless communication, the communication interface 192 may be equipped in a scale and / or configuration that may be appropriate for operating on the network side of wireless communication (e.g., LTE and / or LTE-A communication, as well as WiFi communication, etc.). For example, the communication interface 192 may include multiple transceivers and / or other equipment and / or circuitry for serving multiple WTRUs or other access terminals within a coverage area.

[0057] The processor 194 may include any type of processor or processors that may be deemed appropriate by one of ordinary skill in the relevant art, including, by way of example, a general purpose microprocessor and / or a dedicated DSP.

[0058] The data storage 196 may take the form of (e.g., any) non-transitory computer-readable medium or combination of such media, including flash memory, read-only memory (ROM), and random access memory (RAM). Any type or types of non-transitory data storage that may be deemed appropriate by one of ordinary skill in the relevant art may be used. As shown in FIG. 1F, the data storage 196 may include program instructions 197 that may be executable by the processor 194, for example, to perform various combinations of the various network entity functions described herein.

[0059] In some embodiments, the network entity functions described herein may be performed by a network entity that may have a structure similar to network entity 190 of FIG. 1F. In some embodiments, one or more of such functions may be performed by a combined set of multiple network entities, where one or more (e.g., each) network entity may have a structure similar to network entity 190 of FIG. 1F. In various embodiments, network entity 190 may include (one or more entities within) RAN 103, (one or more entities within) RAN 104, (one or more entities within) RAN 105, (one or more entities within) core network 106, (one or more entities within) core network 107, (one or more entities within) core network 109, (one or more entities within) base station 114a, base station 114b, Node-B 140a, Node-B The network entity may be or may include one or more of: Node-B 140b, Node-B 140c, RNC 142a, RNC 142b, MGW 144, MSC 146, SGSN 148, GGSN 150, eNodeB 160a, eNodeB 160b, eNodeB 160c, MME 162, serving gateway 164, PDN gateway 166, base station 180a, base station 180b, base station 180c, ASN gateway 182, MIP-HA 184, AAA 186, and gateway 188. The above list is by way of example and not limitation, and other network entities and / or combinations of network entities may be used to perform the network entity functions described herein in various embodiments.

[0060] A wireless communication system compliant with Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) can support up to 100 Mbps on the downlink (DL) and up to 50 Mbps on the uplink (UL) for a 2×2 configuration. The LTE DL scheme can be based on an Orthogonal Frequency Division Multiple Access (OFDMA) air interface. A radio frame can include ten 1 ms subframes. A subframe can include two 0.5 ms time slots. There can be six or seven Orthogonal Frequency Division Multiplexing (OFDM) symbols per time slot. Seven symbols per time slot can be used with a normal cyclic prefix (CP) length and six symbols per time slot can be used with an extended CP length. The subcarrier spacing of a particular specification can be 15 kHz. A reduced subcarrier spacing mode, for example using 7.5 kHz, can also be possible. A frame can be or refer to a radio frame.

[0061] A resource element (RE) may be associated with a subcarrier in an OFDM symbol interval. A resource block (RB) may contain 12 consecutive subcarriers in a 0.5 ms timeslot. With 7 symbols per timeslot, an RB may contain 12×7=84 REs.

[0062] For dynamic scheduling, a subframe may contain two consecutive time slots, sometimes called an RB pair. Specific subcarriers on some OFDM symbols may be allocated to carry pilot or reference signals in the time-frequency grid. Some subcarriers at the edge of the transmission bandwidth may not be transmitted in order to comply with the spectral mask requirements.

[0063] Uplink channels that may be provided and / or used may include one or more of a Physical UL Shared Channel (PUSCH), a Physical UL Control Channel (PUCCH), and / or a Physical Random Access Channel (PRACH). Control information, sometimes referred to as UL Control Information (UCI), may be transmitted by the WTRU, for example, on the PUSCH or PUCCH in a subframe, or partly on the PUCCH and partly on the PUSCH. The UCI may include one or more of a Hybrid Automatic Repeat Request (HARQ) ACK / NACK, a Scheduling Request (SR), and / or Channel State Information (CSI), which may include one or more of a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), and a Rank Indicator (RI). Resources that may be allocated for PUCCH transmission may be located at or near the edge of the UL band.

[0064] Downlink channels that may be provided and / or used may include a Physical Downlink Shared Channel (PDSCH) and / or a downlink control channel, which may include one or more of a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid-ARQ Indicator Channel (PHICH), a Physical Downlink Control Channel (PDCCH), and / or an Enhanced PDCCH (EPDCCH).

[0065] One or more symbols in each subframe in the DL, e.g., the first one to three OFDM symbols, may be occupied by one or more of the PCFICH, PHICH, and PDCCH depending on the control channel overhead, and the occupied symbols may be referred to as the DL control region. The PCFICH may be transmitted, for example, in the first OFDM symbol (e.g., symbol 0) in each subframe and / or may indicate the number of OFDM symbols used for the DL control region in the subframe. The WTRU may detect a control format indicator (CFI) from the PCFICH, and the DL control region may be defined in the subframe depending on the CFI value. If the subframe can be defined as a non-PDSCH supportable subframe, the PCFICH may be skipped. The DL symbols that are not part of the DL control region may be referred to as data or PDSCH regions. An extended PDCCH (EPDCCH) may be provided and / or used in the PDSCH region. The location of the EPDCCH in that region may be signaled, e.g., via higher layer signaling, such as Radio Resource Control (RRC) signaling, to WTRUs that may (or may be expected to) monitor, receive, or otherwise use the EPDCCH. The PDCCH and / or EPDCCH may provide, e.g., in DL control information (DCI) format, control information, resource allocations (e.g., grants) for UL and / or DL ​​transmissions, etc.

[0066] DL signals and / or channels may be provided or transmitted by an eNodeB (eNB) and / or may be received and / or used by a WTRU. UL signals and / or channels may be provided or transmitted by a WTRU and / or may be received and / or used by an eNB.

[0067] The signals and / or channels may be associated with a cell, which may correspond to a particular carrier frequency and / or geographic area. The carrier frequency may be a center frequency of the cell (e.g., a center frequency of the supported bandwidth of the cell). An eNB may have one or more cells associated with it. An eNB may be a cell or may refer to a cell.

[0068] In some embodiments, the terms eNB and cell may be used interchangeably. In some embodiments, the terms cell and serving cell may be used interchangeably.

[0069] Synchronization signals, which may include a primary synchronization signal (PSS) and / or a secondary synchronization signal (SSS), may be provided or transmitted, for example, by an eNB or cell. A WTRU may use such signals, for example, to acquire time and / or frequency synchronization with an eNB or cell. The PSS and / or SSS may be present in subframes 0 and / or 5 and / or may be present in every radio frame. The transmission may be the central 62 subcarriers of the cell's bandwidth, with 5 subcarriers on each side of the central 62 subcarriers being reserved or unused. For FDD, the PSS transmission may be in the last OFDM symbol and the SSS transmission may be in the penultimate (e.g., next to last) OFDM symbol of timeslot 0 (e.g., the first timeslot of subframe 0) and timeslot 10 (e.g., the first timeslot of subframe 5) of each radio frame. For TDD, the PSS transmission may be in the third OFDM symbol in subframes 1 and 6, and the SSS transmission may be sent in the last OFDM symbol in timeslot 1 (e.g., the second timeslot of subframe 0) and timeslot 11 (e.g., the second timeslot of subframe 5) of each radio frame. A synchronization signal may carry information regarding the physical cell identity (cell ID) of the cell.

[0070] A Physical Broadcast Channel (PBCH), which may be transmitted by an eNB or cell, may carry cell information such as a Master Information Block (MIB). The PBCH may be provided or transmitted in a specific subframe, such as subframe 0 of each radio frame, and may be repeated, for example, over four consecutive radio frames (e.g., a 40 ms time period). The PBCH may be transmitted in the first four OFDM symbols of the second time slot of subframe 0 and may be transmitted on the 72 center subcarriers. The MIB may provide information such as the cell's DL bandwidth, PHICH information, and at least a portion of the system frame number (SFN), for example, the most significant 8 bits of a 10-bit SFN.

[0071] The downlink reference signals may include cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), and / or demodulation reference signals (DM-RS), and / or positioning reference signals (PRS). DL reference signals may be provided and / or used by the WTRU. The CRS may be used by the WTRU for channel estimation for coherent demodulation of (e.g., any) downlink physical channel. A particular DL channel may include at least one of PMCH, EPDCCH, and PDSCH when configured in a particular transmission mode (TM), such as TM7, TM8, TM9, or TM10. The WTRU may use the CRS for channel state information measurements for CQI, PMI, and / or RI reporting, for example, when the WTRU is configured in a transmission mode using the CRS for PDSCH demodulation. The WTRU may also use the CRS for cell selection and / or mobility related measurements. The CRS may be received in a particular subframe (e.g., any subframe) and multiple antenna ports (e.g., up to four antenna ports) may be supported. The WTRU may use the DM-RS for demodulation of a particular channel, which may include at least one of an EPDCCH and a PDSCH configured in TM7, TM8, TM9, or TM10. The DM-RS may be used for demodulation of a channel (e.g., EPDCCH or PDSCH) and may be transmitted in resource blocks assigned to the channel (e.g., EPDCCH or PDSCH). The WTRU may use the CSI-RS, which may be transmitted in a duty cycle, for channel state information measurements, e.g., if the WTRU may be configured in a transmission mode that may use the DM-RS for PDSCH demodulation. The CSI-RS may also be used for cell selection and mobility related measurements, e.g., if the WTRU may be configured in a transmission mode (e.g., TM10). The WTRU may use the PRS for location related measurements.

[0072] The WTRU may transmit an uplink reference signal, including, for example, a sounding reference signal (SRS) and / or a DM-RS. The SRS may be transmitted in the last SC-FDMA symbol in a set of uplink subframes, which may be configured for a WTRU-specific SRS subframe, which may be a subset of the cell-specific SRS subframe. The SRS may be transmitted by the WTRU periodically in the WTRU-specific SRS subframe within a configured and / or predefined frequency bandwidth. The WTRU may transmit the SRS in an aperiodic manner, for example, if the WTRU can receive an aperiodic SRS (A-SRS) transmission trigger in the DCI format. The WTRU may transmit the DM-RS for PUSCH demodulation at the eNB receiver, and the location of the DM-RS may be in the center of the SC-FDMA symbol in each slot for a resource block in which a PUSCH transmission may be granted (e.g., the fourth SC-FDMA symbol in the normal CP).

[0073] The WTRU may receive user plane and / or control plane data in a PDSCH transmission from the eNB. The WTRU may receive, for example, RLC and / or MAC control information in a PDSCH transmission from the eNB.

[0074] The eNB and / or WTRU may: (i) radio resource control (RRC) connection requests, such as for WTRU initial access and / or registration (e.g., to a cell or eNB) and / or initial access or registration; (ii) connection re-establishment, such as an RRC connection re-establishment that may follow a radio link failure; (iii) access to a handover target cell and / or reset or adjust WTRU UL timing with respect to the handover target cell, e.g., for or during a handover; (iv) a WTRU with respect to a particular cell, such as a serving cell, to gain UL synchronization with the cell, e.g., where UL synchronization may be lost and DL data may arrive or there may be UL data to send. The random access (RA) procedure may be used for at least one of: resetting or adjusting UL timing; (v) transmitting and / or receiving a scheduling request (SR), for example, when the WTRU may have UL data to send and there may be no dedicated resources (e.g., PUCCH resources) assigned that can be used for SR; and / or (vi) positioning purposes, such as when a timing advance that can be used for UL timing adjustment may be required for WTRU positioning.

[0075] The RA procedure may be contention-based (sometimes called common) or non-contention-based (sometimes called contention-free or dedicated).

[0076] When using an RA procedure, which may be a contention-based RA procedure, the WTRU may start the process by transmitting an RA preamble, which may be randomly selected from a common pool of preambles, which may be communicated to the WTRU by the network via broadcasted system information, etc. The WTRU may transmit the preamble on a PRACH resource (e.g., a time and frequency resource), which the WTRU may select from a set of allowed resources, which may be communicated to the WTRU by the network via broadcasted system information, etc. The PRACH resources of the configured set of the cell may be or may include this set of allowed PRACH resources. The unit of time for the PRACH resources may be a subframe. The subframe that the WTRU selects (or may select) for the PRACH resource may be the next subframe configured for PRACH, in which the WTRU may transmit the PRACH (e.g., based on timing, measurements, and / or other WTRU considerations). The WTRU may select a frequency aspect (e.g., resource block (RB)) of the PRACH resource in the selected subframe based on parameters that may be communicated by the network to the WTRU via, e.g., broadcasted system information. A frequency resource (e.g., one or at least one frequency resource) may be allocated for the PRACH in the FDD or other subframe. It may be defined by a starting (e.g., lowest) RB number, e.g., prach-FrequencyOffset, that may be provided by the network and may have a fixed bandwidth, such as 6 RBs.

[0077] Multiple WTRUs may select the same resources (eg, preamble and PRACH resources) for random access, and the contention situation may be resolved if a contention-based random access procedure is used or otherwise.

[0078] The WTRU may transmit an RA preamble, e.g., ra-PreambleIndex, which may be signaled (e.g., explicitly) by the network to the WTRU when using a non-contention based RA procedure. The WTRU may transmit the preamble on a PRACH resource that it selects from a particular subset of the cell's configured PRACH resources. The subset (e.g., a mask) may be signaled (e.g., explicitly) by the network to the WTRU, e.g., as ra-PRACH-MaskIndex. The WTRU may use the indicated resource if the subset includes one option or otherwise.

[0079] It is contemplated that the preamble transmission may span or be repeated across multiple subframes, e.g., for contention-based and / or contention-free RA. The selected subframe (e.g., for transmission) may be, e.g., the starting subframe for the transmission in this case and / or other cases.

[0080] The PRACH preamble may be considered as a PRACH resource. For example, the PRACH resource may include a PRACH preamble, a time and / or a frequency resource.

[0081] It is contemplated that the terms RACH resource and PRACH resource may be used interchangeably. It is further contemplated that RA, RACH, and PRACH may be used interchangeably. It is further contemplated that PDCCH and EPDCCH may be used interchangeably. (E)PDCCH may be used to represent PDCCH and / or EPDCCH.

[0082] 2 shows an example random access procedure 200. At 202 (e.g., msg1), the WTRU transmits (or may transmit) a preamble, which may be at a particular power level. The eNB that receives (or may receive) the preamble may respond with a Random Access Response (RAR), e.g., msg2, at 204. If the WTRU does not receive the RAR within a particular time window, the WTRU may transmit another preamble (which may be different from the previous preamble) and transmit it at a higher power (e.g., ramp up the power, such as by following a ramping protocol). The WTRU may wait for a certain backoff time before ramping the power and trying again. The WTRU may repeat transmitting the preamble until at least one of the following events occurs: the WTRU receives a RAR directed (or may be directed) to it, the WTRU reaches (or exceeds) its maximum power, and / or the WTRU reaches (or exceeds) a maximum number of allowed ramps. If the WTRU reaches or exceeds one of the maximum values, the WTRU may consider the random access procedure 200 to have failed. The ramping step (e.g., powerRampingStep) and maximum number of ramps (e.g., preambleTransMax) may be provided by the eNB, such as via system information that may be broadcast.

[0083] When the WTRU receives the RAR, the RAR may include one or more of a grant for resources on which the WTRU may send an UL transmission (e.g., msg3) at 206, a Cell (C)-Radio Network Temporary Identifier (C-RNTI) or a Temporary C-RNTI (TC-RNTI), and / or a Timing Advance (TA). In response to the RAR, the WTRU may transmit in the UL at 206 (e.g., msg3) on the granted resources and may adjust its UL timing according to the TA. In the case of a contention-free RA procedure, the random access procedure 200 may end at 206.

[0084] In the case of a contention-based procedure, contention resolution may occur at 208 (e.g., msg4). The contention resolution message may include information (e.g., C-RNTI or TC-RNTI) that indicates or identifies the WTRU for which the RAR was intended. If the WTRU receives a contention resolution message that indicates that it was the WTRU for which it was intended, the WTRU may consider the random access procedure 200 successful. If not, the WTRU may consider the random access procedure 200 to have failed and may try again.

[0085] At 202, the WTRU may transmit an RA preamble on the selected or identified PRACH resource. After transmitting the preamble, the WTRU may monitor and / or read the PDCCH or EPDCCH and / or look for a Random Access RNTI (RA-RNTI) that corresponds (or may correspond) to the first subframe in which the WTRU transmitted the preamble. The RA-RNTI may indicate the presence of an RAR that may be directed to the WTRU. The RA-RNTI may be determined, for example, according to RA-RNTI=1+t_id+10*f_id, where t_id may be the index of the first subframe of the PRACH used for preamble transmission (e.g., 0≦t_id≦10) and f_id may be the index of the PRACH used for preamble transmission in that subframe, e.g., in ascending order in the frequency domain (e.g., 0≦f_id≦6). The value f_id may always be 0 in the case of one frequency resource per subframe, in the case of FDD, and / or in other cases.

[0086] At 204, an RAR may be provided and / or used. The RAR may be transmitted by the eNB and may include, for example, a timing advance command to adjust the WTRU transmission timing and / or an allocation (e.g., grant) for uplink resources for the WTRU. The RAR may be sent on the PDCCH (or EPDCCH). The RAR may use the RA-RNTI to identify which WTRU group the allocation (e.g., scheduling grant) is (or may be) intended for. Within each group, the RA preamble identifier (RAPID) may be used to further refine (e.g., at the MAC level) the WTRU group identified (or may be) identified by the RA-RNTI, for example, to a subset of WTRUs that used (or may have used) the same preamble during the preamble transmission (202) of the random access procedure. The RA response may include one or more of: (i) an index of a random access preamble sequence that the network may have detected and / or for which the response is (or may be) valid; (ii) a timing correction that may be calculated by the random access preamble receiver; (iii) a scheduling grant; and / or (iv) a TC-RNTI.

[0087] At 206, a scheduled (or granted) transmission may be made by the WTRU. The WTRU may transmit a message, such as an RRC connection request, at 206 using the allocated resources indicated by the scheduling grant (which may be included in the RAR). If the WTRU is connected to a known cell (e.g., in RRC CONNECTED state), the WTRU may have a C-RNTI that it may include in the uplink message. Otherwise, a core network terminal identifier may be used. The uplink transmission (UL SCH) may be scrambled by the WTRU using the TC-RNTI received in the RAR.

[0088] At 208, contention resolution may be performed and / or used. The eNB may send a contention resolution message, for example on the PDCCH (or EPDCCH), which may be based on the C-RNTI or the WTRU contention resolution identity, e.g., a core network terminal identifier, that the WTRU may have sent in msg3 (206). A WTRU that observes a match between the indication or identity received at 208 and the indication or identity it itself transmitted at 206 may declare the RA procedure successful. Contention between WTRUs that select the same PRACH time-frequency resource and the same preamble may be resolved in this manner.

[0089] For an RA, such as a contention-based RA, the WTRU may derive a common pool of preambles from parameters that may be provided by the network. From these parameters, the WTRU may derive a full set of preambles, which may be based on one or more root Zadoff-Chu sequences, e.g., a specific number, such as 64 preambles. The parameter that may specify the sequence or sequences to use may be rootSequenceIndex. The WTRU may receive additional parameters that may indicate a subset of preambles that may be used by the WTRU and how to divide this subset into groups, such as two groups A and B. For example, numberOfRA-Preambles may define the subset of preambles. A first sizeOfRA-PreamblesGroupA is in group A (e.g., preamble 0 to sizeOfRA-PreamblesGroupA-1), and the remaining preambles in the subset, if any (e.g., sizeOfRA-PreamblesGroupA to numberOfRA-Preambles-1), may be in group B. When using group A vs. group B, the preamble may be known to the WTRU. The decision may be based on criteria such as the size of msg3 and / or path loss (PL). Preambles in the full set that are not present in group A or B may be used by the network when it assigns a dedicated preamble, for example, for contention-free RA.

[0090] A PRACH configuration index, e.g., prach-ConfigIndex, may be used by the network to signal to (and / or determined by) the WTRU which of a preconfigured list of possible configurations is (or may be) selected for the PRACH resources of the configured set of the cell. The preconfigured configuration may define, for example, for FDD, one or more of a preamble format, which may define a time for a preamble cyclic prefix (CP) and a time for a preamble sequence, a system frame number (SFN) for which PRACH may be enabled (e.g., any, even only, odd only), and subframes of the enabled SFN for which PRACH may be enabled (e.g., 1, 2, 3, 4, or 5 specific subframes, or all 10 subframes).

[0091] In an UL transmission, the WTRU may perform power control based on several factors, which may include, among others, (1) the measured path loss on the DL carrier, (2) a transmit power control (TPC) command (e.g., from the eNB), (3) the number of resource blocks on which it may transmit, and / or (4) other static or quasi-static parameters.

[0092] Static or semi-static parameters may be provided by the eNB or other network resources. The parameters and / or power control formulas and / or power control procedures may be established or found, for example, based on the LTE or LTE-A standards. The power control procedures may take into account the possibility that the WTRU's calculated transmit power may exceed its maximum allowed transmit power and provide for the WTRU to scale back its transmit power so as not to exceed the maximum allowed transmit power.

[0093] The maximum enabled transmit power (or maximum configured output power) P CMAXmay be a function of one or more of the WTRU's power class, power limits that may be signaled by the eNB, and / or power reductions that the WTRU may be allowed to make, which may be based on, for example, out-of-band emission requirements or signals to be transmitted by the WTRU to avoid exceeding an allowed value or level. For example, for LTE / LTE-A transmissions, the WTRU may reduce its maximum output power based on a maximum power reduction (MPR), an additional MPR (A-MPR), and / or one or more allowed allowable values ​​such as ΔTc and ΔTib, and / or other allowed reductions. The MPR, A-MPR, ΔTc, and ΔTib values ​​may be found in the LTE / LTE-A standards. Which values ​​the WTRU may use may be based on one or more combinations of several transmission characteristics and signaling from the eNB. The values ​​may be considered by the WTRU to be the maximum allowed values, and as such, the WTRU may use the MPR, A-MPR, ΔTc, ΔTib values, and / or other smaller values. Power management power reduction (P-MPR) is CMAX may be used to reduce

[0094] It is contemplated that one or more (e.g., all) of maximum allowed transmit power, maximum enabled power, maximum enabled output power, maximum enabled transmit power, maximum transmit power, maximum power, maximum output power, maximum transmit power, maximum UL transmit power, maximum configured output power, and / or maximum configured output power may be used interchangeably.

[0095] A WTRU that supports carrier aggregation, e.g., according to LTE Release 10 (R10), may be configured with one or more serving cells (or component carriers (CCs)), and for each CC the WTRU may be configured for UL communications. It is contemplated that CC and serving cell may be used interchangeably and still be consistent with the embodiments contained herein.

[0096] The WTRU can perform power control (PC) for each UL channel on each component carrier (or CC). The configured maximum output power P CMAX,c For a UL CC, e.g., a primary CC, there may be multiple P CMAX,c The WTRU may perform PC on a subframe basis and may determine (e.g., only determine) the power for the channel on which it should or will perform UL transmission in the subframe.

[0097] The transmit power for the PUCCH may be determined, for example, by the WTRU. In an example, the PUCCH power, such as the LTE-A PUCCH power, may be

[0098]

number

[0099] It can be determined according to:

[0100] P CMAX,c (i) is the configured maximum output power for the serving cell c, which is determined by the WTRU as MIN(Pemax cThe power reduction may be configured to a value between a high value, which may be equal to Pemax,c,Ppowerclass, and a low value, which may be equal to the minimum of Pemax,c and Ppowerclass minus a combination of allowed power reductions, which may include one or more of MPR, A-MPR, P-MPR, ΔTc, and ΔTib, depending on the circumstances. The power reduction may be WTRU or CC specific. Ppowerclass may be the maximum power of the WTRU's power class. Pemax c p-max may be the maximum allowed output power for CC c, which may be signaled to the WTRU, eg, by the eNB via RRC signaling, and may correspond to the signaled p-max for that CC.

[0101] Δ F_PUCCH (F) is a function of the PUCCH format used for transmission.

[0102] h(n CQI ,n HARQ ,n SR ) is a function of the PUCCH format and the number of bits of each type (CQI, HARQ, SR) being transmitted.

[0103] P O_PUCCH is two parameters (e.g., P O_N0MINAL_PUCCH and P O_UE_PUCCH ) is a parameter that can be constructed from

[0104] PL C is the path loss for the CC, which may be determined by the WTRU, for example, from measurements.

[0105] g(i) is an adjustment factor that can be called the PUCCH power control adjustment state. g(i) is the new P O power ramp-up delta after RA procedure (which may be zeroed if PUCCCHThe accumulation may be as follows:

[0106]

number

[0107] Here, for example, M=1 and K0=4 can be applied to FDD. In another example that applies to TDD, M and k m The value of may be a function of the TDD UL / DL configuration.

[0108] The TPC command for the PUCCH can be transmitted in a particular DCI format (e.g., a PDCCH or EPDCCH having a particular DCI format), such as DCI format 3 / 3A, or with a DL grant in DCI format 1A / 1B / 1D / 1 / 2A / 2B / 2C / 2, and can be, for example, +1 or -1 dB in format 3A, or 0 (hold), -1, +1, or +3 dB in other formats. If a PDCCH (or EPDCCH) having DCI format 1 / 1A / 2 / 2A / 2B is enabled as a semi-persistent scheduling (SPS) activation PDCCH, or if a PDCCH having DCI format 1A is enabled as an SPS release PDCCH, δ PUCCH may be 0 dB.

[0109] The transmit power for the PUSCH may be determined, for example, by the WTRU. In an example, the PUSCH power, such as the LTE-A PUSCH power, may be

[0110]

number

[0111] where the PUCCH term may be present (or non-zero) if or only if PUSCH and PUCCH are being transmitted simultaneously in subframe i.

[0112] The parameters in Equation 2 may be similar to those described for the PUCCH power. For the PUSCH, the adjustment factor, which may be the accumulation of the TPC commands, is CC-specific f c (i) can be expressed as: c (0) may be a function of the power ramp-up after the RA procedure and / or TPC commands that may be received in the RAR.

[0113] M PUSCH,c , may be the bandwidth of the PUSCH resource allocation, which may be expressed in number of resource blocks.

[0114] P O_PUCCH,C (j) is a component P that may have a known value or may be provided by a higher layer. O_N0MINAL_PUCCH,C (j) and component P O_UE_PUCCH,C (j). The value of j may be a function of the type of transmission. For example, for a PUSCH (re)transmission that may correspond to a semi-persistent grant, j may be 0. For a PUSCH (re)transmission that may correspond to a dynamic scheduled grant, j may be 1. For a PUSCH (re)transmission that may correspond to a RAR grant, j may be 2.

[0115] α c (j) can, for example, be based on the value of j, be a known value, or be provided by a higher layer.

[0116] The transmit power for the PRACH may be determined, for example, by the WTRU. In an example, the PRACH power, such as the LTE-A PRACH power, may be P PRACH =min{P CMAX,c (i),PREAMBLE_RECEIVED_TARGET_POWER+PL C} Equation 3 where PREAMBLE_RECEIVED_TARGET_POWER may be indicated by a higher layer.

[0117] P CMAX,c (i) may be, for example, the configured maximum output power for the serving cell c, as described with respect to the PUCCH power. C , may be a path loss for the CC, which may be determined by the WTRU, for example from measurements.

[0118] The PREAMBLE_RECEIVED_TARGET_POWER may be determined at a higher layer, such as the MAC layer, by the WTRU, for example. PREAMBLE_RECEIVED_TARGET_POWER={preamblelnitialReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE TRANSMISSION COUNTER-1)*powerRampingStep} Equation 4 can be followed.

[0119] The values ​​of preamblelinitialReceivedTargetPower and / or powerRampingStep may be configured by the eNB, for example, via signaling such as broadcast or dedicated signaling.

[0120] DELTA_PREAMBLE may be determined as a function of the PRACH format the WTRU can use, which may be according to configuration and / or signaling from the eNB, such as broadcast or dedicated signaling.

[0121] PREAMBLE_TRANSMISSION_COUNTER may be used to ramp the power for the PRACH transmission. PREAMBLE_TRANSMISSION_COUNTER may be set to 1 for the first PRACH transmission and increased by +1 for each PRACH retry or retransmission. Power ramping with powerRampingStep may be achieved in this way.

[0122] The physical resources that may be used for the PUCCH may be determined by parameters that may be provided by higher layers, e.g.,

[0123]

number

[0124] and

[0125]

number

[0126] The parameter, which can be an integer greater than or equal to 0,

[0127]

number

[0128] represents the bandwidth in terms of resource blocks available for use by a particular PUCCH format for transmission, such as PUCCH format 2 / 2a / 2b, in each slot.

[0129]

number

[0130] represents the number of cyclic shifts that may be used for a PUCCH format, such as PUCCH format 1 / 1a / 1b, in a resource block that may be used for a particular mix of formats, such as formats 1 / 1a / 1b and 2 / 2a / 2b.

[0131]

number

[0132] The value of is

[0133]

number

[0134] , which may be in the range {0, 1, ..., 7};

[0135]

number

[0136] may be provided by a higher layer.

[0137]

number

[0138] If , there are no mixed resource blocks. One (e.g., at most one) resource block in each slot can support a mix of formats 1 / 1a / 1b and 2 / 2a / 2b. The resources that can be used for transmitting PUCCH formats 1 / 1a / 1b, 2 / 2a / 2b, and 3 are each denoted by a non-negative index .

[0139]

number

[0140] ,

[0141]

number

[0142] , and

[0143]

number

[0144] It can be represented by:

[0145] Complex Value Symbols

[0146]

number

[0147] For example, a block consisting of the transmission power P PUCCH To match PUCCH can be multiplied by

[0148]

number

[0149] The PUCCH may use one resource block in each of two slots in a subframe. Within the physical resource blocks that may be used for transmission, the PUCCH may be mapped to resource elements (k,l) in antenna port p that are not used for transmitting the reference signal.

[0150]

number

[0151] The mapping of may be first k, then l, and finally in ascending order of slot numbers starting from the first slot in the subframe.

[0152]

number

[0153] An example of the relationship between and antenna port number p may be given by Table 1.

[0154] [Table 1]

[0155] Slot n s The physical resource blocks that can be used for transmitting the PUCCH in

[0156]

number

[0157] where the variable m may depend on the PUCCH format.

[0158] In the example, for formats 1, 1a, and 1b, m is:

[0159]

number

[0160] In another example, for formats 2, 2a and 2b, m can be determined according to:

[0161]

number

[0162] In another example, for format 3, m can be determined according to:

[0163]

number

[0164] It can be determined according to:

[0165] The mapping of modulation symbols for the PUCCH may be, for example, as shown in Table 2.

[0166] [Table 2]

[0167] A shortened PUCCH format may be used, when, for example, in case of simultaneous transmission of SRS and PUCCH, the last SC-FDMA symbol in, for example, the second time slot of a subframe may be left empty. The shortened PUCCH may apply to one or more of PUCCH formats 1, 1a, 1b, and / or 3. The shortened PUCCH may apply when there may be one serving cell configured, or one serving cell with a configured and / or activated UL.

[0168] For a particular PUCCH format, such as PUCCH format 1a / 1b, HARQ-ACK transmission on two antenna ports, for example (p ∈ [p0, p1]), may be supported.

[0169] The WTRU allocates a PUCCH resource for the transmission of HARQ-ACK in subframe n.

[0170]

number

[0171] where:

[0172]

number

[0173] is mapped to antenna port p for a particular PUCCH format, such as PUCCH format 1a / 1b.

[0174] In an example that may include one serving cell and / or may use FDD, for a PDSCH transmission (e.g., in subframe n-4) that may be indicated by detection of a corresponding PDCCH in subframe n-4, or for a PDCCH that may indicate a downlink SPS release in subframe n-4, the WTRU may

[0175]

number

[0176] can be used, where n CCE is the number of first control channel elements (CCEs) used for transmitting the corresponding DCI allocation (e.g., the lowest CCE index used to configure the PDCCH);

[0177]

number

[0178] can be configured by higher layers. For two-antenna port transmission, the PUCCH resource for antenna port p1 is

[0179]

number

[0180] It can be given by:

[0181] In another example where FDD may be used, for example in the case of DL SPS, for a PDSCH transmission on a cell (e.g., a primary cell) for which there may be no corresponding PDCCH detected in subframe n-4:

[0182]

number

[0183] The value of may be determined according to a mapping, such as by a higher tier configuration, and / or a table, such as Table 3. Signaling, such as a PUCCH TPC command, may be used to select the mapping, such as in a table. The PUCCH resource value may be, for example, a single PUCCH resource for antenna port p0 for a single antenna port transmission.

[0184]

number

[0185] For a WTRU configured for two antenna port transmission, for example, the PUCCH resource values ​​in Table 3 may be mapped to two PUCCH resources, for example the first PUCCH resource for antenna port p0.

[0186]

number

[0187] and a second PUCCH resource for antenna port p1

[0188]

number

[0189] can be mapped to

[0190] [Table 3]

[0191] System information may be provided, for example, by an eNB and / or used by the WTRU. The WTRU may acquire system information related to cells and / or networks that it may use, among other things, for cell selection, access, and / or connection establishment. System information may be broadcast by cells in blocks. One or more information blocks may be used by the WTRU for a cell. One cell may provide system information for another cell. For example, a primary cell may provide system information for a secondary cell for carrier aggregation.

[0192] A MIB may be provided and / or used. The MIB may be transmitted on the PBCH in a particular subframe, such as subframe 0, and may have a fixed transmission time interval (TII), for example, 40 ms. The MIB may be repeated every 10 ms. The information included in this block may include one or more of at least a portion of the SFN (e.g., the most significant 8 bits of the SFN), the configured DL bandwidth of the cell, and / or the PHICH configuration for the cell. By acquiring one of the four repeated MBIs in the 40 ms TTI, the WTRU may be able to derive the least significant 2 bits of the SFN for the complete SNF value.

[0193] A system information block (SIB) may be transmitted on the PDSCH. The resource location of the SIB may be indicated by the (E)PDCCH, which may be scrambled by the system information (SI)-RNTI. The SIB, e.g., SIB type 1 (SIB1), may provide information that the WTRU can use to access the cell and / or network, and / or scheduling information regarding other SIBs. The SIB, e.g., SIB1, may be transmitted in a particular subframe, such as subframe 5, may have a TTI that may be fixed (e.g., 80 ms), and / or may be repeated periodically (e.g., every 20 ms).

[0194] The SIB, e.g., SIB type 2 (SIB2), may be transmitted on the PDSCH based on scheduling information that may be included in another SIB, e.g., SIB1. The resource location may be indicated by the (E)PDCCH scrambled by the SI-RNTI. The SIB, e.g., SIB2, may provide information that the WTRU may use to access and / or initiate a connection to a cell and / or network. The information in the SIB, e.g., SIB2, may include one or more of the following: channel common configuration for the PRACH and / or RACH, Multimedia Broadcast multicast service Single Frequency Network (MBSFN) subframe configuration, UL information, among others.

[0195] Scheduling information may be provided and / or used, which may include a scheduling information list for system information (SI) messages. The scheduling information list, e.g., schedulinglnfoList, may provide a mapping of SIBs to SI messages, e.g., except for SIB1. The (e.g., each) SI message may include one or more SIBs, and / or each SIB may be mapped to one or only one SI message. Scheduling of SIs may be based on the periodicity of the system information and / or the SI window length. For example, SIBs (e.g., only SIBs) with the same periodicity may be mapped to the same SI message. SIB2 may be mapped or always mapped to a particular SI message, e.g., the SI message that may correspond to the first entry of a list of SI messages in the scheduling information list. The eNodeB may have some flexibility regarding time and frequency resources for sending SIBs.

[0196] Other SIB information may be related to cell reselection information, handover, Multimedia Broadcast Multicast Service (MBMS), emergency and / or warning system related information that the WTRU can use, among others. Some SIBs may be optional based on the cell and / or network configuration and may not be transmitted by the cell.

[0197] Methods and procedures for link adaptation of the PRACH may be provided and / or used.

[0198] The downlink measurements may include one or more measurements of a reference signal received power (RSRP), a path loss, and / or a wideband channel quality indicator (CQI). The downlink measurements may include one or more of a measurement defined as a function of RSRP, a measurement defined as a function of path loss, and / or a measurement defined as a function of wideband CQI. It is contemplated that RSRP may be replaced with another downlink measurement, in particular path loss, wideband CQI, a measurement defined as a function of RSRP, a measurement defined as a function of band CQI, etc., while remaining consistent with an embodiment.

[0199] The PRACH preamble may be transmitted, e.g., repeatedly across two or more subframes, e.g., to extend coverage. The WTRU may transmit a PRACH preamble that may be selected (e.g., by the WTRU) for random access, such as contention-based random access, in one or more subframes for which PRACH resources may be configured. For example, the number of subframes in which the WTRU may transmit (e.g., repeatedly) the same PRACH preamble may vary, e.g., depending on the coverage extension (CE) level of the WTRU. For example, N1 repetitions may be used for CE level 1. A WTRU that may be configured or may select CE level 1 may be able or need to transmit a PRACH preamble that may be chosen for random access, such as contention-based random access, N1 times (e.g., in N1 subframes), where each transmission may be in an associated PRACH resource that may correspond to N1 subframes. If the WTRU may be configured or may select CE level 2, the WTRU may be able or may need to transmit a PRACH preamble N2 times (e.g., in N2 subframes), where each transmission may be in an associated PRACH resource that may correspond to N2 subframes, which may be chosen for random access, such as contention-based random access. If CE level 2 has better coverage extension than CE level 1, N2 may be a value greater than N1. The CE levels and / or associated parameters for each CE level may include, but are not limited to, one or more of a PRACH resource configuration, a power control parameter, and / or a number of repetitions. There may be or the eNB may support several CE levels, e.g., L or up to L levels, where L may be 3.For example, the number of CE levels that may be supported by an eNB and / or one or more CE levels and / or associated parameters for the CE levels may be provided by signaling, such as broadcast signaling, from an eNB that can support CE or a WTRU in a CE mode.

[0200] A CE mode may correspond to a mode of operation in which one or more CE levels are supported and / or used, and / or coverage extension techniques may be used, for example, by the WTRU and / or eNB.

[0201] It is contemplated that a WTRU configured in or for a particular mode, such as CE mode, may be able to use or be in that mode. In some embodiments, configured in a mode or configured for a mode may be used interchangeably with using a mode or being in a mode.

[0202] In an embodiment, PRACH resources for two or more CE levels may be multiplexed in the code domain, and the same PRACH time / frequency resource may be used for two or more CE levels. PRACH can be configured for CE mode, N PRACH The preambles may be grouped and / or partitioned into subsets that may correspond to the number of CE levels supported in the cell. Time / frequency may correspond to and / or be used to represent time and / or frequency.

[0203] In the example, N PRACH The preambles may be grouped into the number of CE levels supported (e.g., by an eNB or cell), and each CE level may have several (e.g., the same number) PRACH preambles. The number of CE levels may be N CEThe WTRU may be provided by the eNodeB as a parameter such as N PRACH and / or N CE For example, at each CE level, Ngrp[N PRACH / N CE ] preambles may be grouped.

[0204] The PRACH preambles may be grouped, for example, in ascending order. PRACH The first (e.g., lowest number or index) preamble (e.g., Ngrp preamble) that may be in the set of preambles may be associated with the first CE level (e.g., the CE level with the lowest number or configured index, and / or the smallest or lowest CE). The next group (e.g., next higher number or index) of preambles (e.g., Ngrp preamble) may be associated with the next CE level (e.g., the CE level with the next higher number or configured index, and / or the next highest CE), and so on.

[0205] The PRACH preambles may be grouped, for example, in descending order. PRACH The highest possible number or index preamble in the set of preambles (e.g., Ngrp preamble) may be associated with the first CE level (e.g., the CE level with the lowest number or configured index, and / or the smallest or lowest CE). The next group of preambles (e.g., the next lower number or index) (e.g., Ngrp preamble) may be associated with the next CE level (e.g., the CE level with the next higher number or configured index, and / or the next highest CE), and so on.

[0206] The number of PRACH preambles is N CEIf the remainder is not divisible by , then the remainder may belong to a particular CE level. The particular CE level may be the first CE level (e.g., the CE level with the lowest number or configured index and / or the smallest or lowest CE). Alternatively, the particular CE level may be the last CE level (e.g., the CE level with the highest number or configured index and / or the largest or highest CE).

[0207] In another example, the PRACH preambles for each CE level may be indicated (e.g., explicitly) by the eNodeB, e.g., via broadcasting signaling and / or SIBs, etc. A PRACH preamble list may be provided for each CE level, which may identify the specific preambles for each CE level.

[0208] A starting (or initial) PRACH preamble (or preamble index or indicator) and several preambles may be provided for each CE level (eg, both), and the preambles for the CE levels may be consecutive.

[0209] A starting (or first) PRACH preamble (or preamble index or indicator) may be provided, and several preambles may be provided for each CE level. The preambles for each CE level may be consecutive, and the groups of preambles for different CE levels may be adjacent. The WTRU may have knowledge of which level starts with the provided starting (or first) preamble, and may use the number of preambles at the first CE level to determine the starting (or first) PRACH preamble of the second CE level. The WTRU may determine the preambles in each group from the starting preamble, the number of groups, and the number of preambles in each group. If the number of preambles in each group is the same, one value may be used to represent the number of preambles, instead of one value per CE level. If the number of preambles in each group is the same and known to the WTRU (e.g., a fixed known value), the number of preambles in each group may not be provided, e.g., only the starting (or first) PRACH preamble (or preamble indicator) may be provided by the eNodeB.

[0210] In an embodiment, the starting subframe for PRACH preamble transmission may be configured separately for each CE level and / or may differ depending on the CE level. Each CE level may have, for example, a specific PRACH time window in which the PRACH preamble may (or may need to) be transmitted, respectively. Figure 3 shows an example of PRACH transmission time windows depending on the CE level. In the example of Figure 3, the CE level 1 window may include 4 PRACH resources, and thus the PRACH preamble belonging to CE level 1 may (or may need to) be transmitted 4 times in this window, e.g., N1 = 4. The CE level 2 window may include 8 PRACH resources, which may be twice larger than CE level 1, e.g., N2 = 8. In the example of Figure 3, the time windows for the CE levels may overlap.

[0211] The WTRU may select or be configured with a particular CE level and may transmit a PRACH preamble belonging to a set of PRACH preambles that may be associated with the CE level on a PRACH resource (e.g., a selected time / frequency resource). The PRACH preamble may be transmitted in a first PRACH resource in the PRACH window and may be repeatedly transmitted in other PRACH resources in the PRACH window.

[0212] A PRACH window (which may be or may be referred to as a number of consecutive subframes) may be (or may be defined as) a function of a PRACH resource configuration (which may be referred to as a PRACH subframe configuration) and / or a number of repetitions of or associated PRACH preamble transmissions for a particular CE level. Within a PRACH window associated with a CE level, a PRACH preamble that may belong to the CE level may be or may need to be transmitted in one or more (e.g., all) of the PRACH resources configured for the CE level in the window.

[0213] PRACH windows for one or more CE levels may be overlapped in time. For example, as shown in FIG. 3, a CE level 2 PRACH window may be overlapped with one or more CE level 1 PRACH windows. A PRACH resource (e.g., time and / or frequency resource) may be shared by two or more CE levels, and mutually exclusive PRACH preambles (or non-overlapping PRACH preamble sets) may be used, for example, to multiplex one or more CE levels on the same PRACH resource in this and other cases. For example, a PRACH preamble that may belong to a PRACH preamble group (e.g., PRACH preamble indexes 0 to N) associated with CE level 1 may be transmitted, for example, repeatedly across four subframes that include the PRACH resource. Another PRACH preamble belonging to a PRACH preamble group (e.g., PRACH preamble indexes N+1 to M) associated with CE level 2 may be repeatedly transmitted over eight subframes including PRACH resources, and these PRACH resources (e.g., time and / or frequency resources) may be shared by CE level 1 and CE level 2. The PRACH resources (e.g., time and / or frequency resources) may not be overlapped in multiple CE levels. For example, the PRACH resources for CE level 1 may not be used for other CE levels. One or more (e.g., all) PRACH preambles may be the same for multiple (e.g., all) CE levels, for example, when the PRACH resources for the multiple CE levels are not overlapped.

[0214] The PRACH windows for the CE levels may be located in a subset of subframes, for example, the PRACH windows for CE level 1 may be located in (e.g., only in) even-numbered radio frames, and the PRACH windows for CE level 2 may be located in (e.g., only in) odd-numbered radio frames.

[0215] In another embodiment, PRACH resources for two or more CE levels may be multiplexed in non-overlapping or partially overlapping time / frequency resources. For example, PRACH resources for CE levels such as CE level 1 and CE level 2 may be located in one or more different subframes and / or different frequency bands (e.g., different RBs), and / or PRACH resources that may be used for non-CE operation (e.g., legacy PRACH resources). Figures 4 and 5 show examples of time and / or frequency domain multiplexing of PRACH resources for two or more CE levels.

[0216] A set of time and / or frequency PRACH resources may be configured for a CE mode (e.g., one or more CE levels), where the PRACH resources for the CE mode do not overlap (in time and / or frequency) with PRACH (e.g., legacy PRACH) resources that may be used for normal mode (e.g., non-CE mode) and / or that may be used without PRACH repetition.

[0217] The PRACH resources for the CE mode may be located in frequency bands (eg, RBs) that do not overlap with the PRACH resources for normal (eg, non-CE) mode.

[0218] The PRACH resources for the CE mode may be in a subframe containing other (e.g., legacy) PRACH resources in a different frequency band (e.g., RB) than the PRACH resources that may be used for the CE mode. The frequency location for the CE mode may be changed over time, e.g., to obtain frequency diversity gain. For example, a frequency hopping pattern is defined for the PRACH resources for the CE mode, while the frequency location for the normal mode may be fixed or semi-static.

[0219] A set of preambles that may be used for non-CE (e.g., legacy) operation may be reused for CE mode, for example, when the time and / or frequency resources for the PRACH in CE mode do not overlap with the time and / or frequency resources for the PRACH in non-CE mode (e.g., legacy PRACH).

[0220] FIG. 4 shows an example of PRACH resource frequency division multiplexing between normal mode and CE mode.

[0221] A set of PRACH time and / or frequency resources may be configured for CE mode. The PRACH resources may be used for normal mode and / or shared with PRACH resources that do not use or support PRACH repetition (e.g., legacy PRACH resources). The PRACH preambles may be partitioned for normal mode and CE mode. For example, M (e.g., 64) PRACH preambles may be configured (or available) for both normal mode and CE mode, the first N preambles may be used for normal mode, and the next P (P≦MN) preambles may be used for CE mode. This may be applicable when the PRACH resources may be shared for normal and CE. In another example, M (e.g., 64) PRACH preambles may be configured (or available) for both normal mode and CE mode, the first N preambles may be used for normal mode (e.g., for contention-based RA), and the next P (P≦MN) preambles may be used for CE mode (e.g., for contention-based RA). The next Q (Q=MNP or Q≦MNP) preambles may be used for non-contention based RA in normal or CE mode, where the mode may depend on the WTRU to which the preamble is assigned, e.g., based on the mode in which the WTRU may be operating. This may be applicable when the PRACH resource may be shared for normal and CE. Figure 5 shows an example of PRACH resource code division multiplexing (CDM) between normal and CE modes.

[0222] Means for CE level determination for PRACH transmission may be provided and / or used.

[0223] Two or more CE levels may be used for PRACH transmission, and each CE level may be associated with one or more PRACH resources, which may include time / frequency resources and a PRACH preamble. The PRACH resources associated with a CE level may not be overlapped (e.g., in at least one of time and / or frequency and / or preamble). The WTRU may determine the associated PRACH resources for PRACH transmission based on the determined and / or configured CE level.

[0224] In an embodiment, the WTRU may determine a CE level (or a starting CE level) as a function of downlink measurements. The CE level may be changed, e.g., by the WTRU, in or for a subsequent PRACH preamble transmission, e.g., based on a PRACH preamble retransmission (or attempt) at the current CE level.

[0225] The WTRU may determine a CE level (or a starting CE level) in the range of CE levels supported in the cell from the downlink measurements. For example, if the RSRP measurement result is x dB, the WTRU may select a CE level based on x dB.

[0226] A mapping rule between RSRP values ​​or ranges of RSRP values ​​and CL levels may be used. For example, a look-up table may be used in which RSRP measurement results are mapped onto a particular CE level. The WTRU may measure the RSRP and determine the CE level by using a mapping rule (e.g., a look-up table). If the CE level selected from the mapping rule is not supported in the cell, a higher CE level may be selected instead, and the higher CE level may have a larger number of repetitions. The mapping may be a function of the WTRU implementation and / or a configuration that may be provided by the eNB via signaling, e.g., broadcast signaling.

[0227] The CE level may be determined based on the number of iterations that the WTRU can use, and the number of iterations may be determined based on an assumption that a maximum uplink transmit power may be used, e.g., for PRACH transmission. For example, the WTRU may (e.g., initially) estimate or determine one or more CE levels that can provide sufficient CE, e.g., based on downlink measurements. The WTRU may determine a CE level (or a starting CE level) that has a minimum (or lowest) number of iterations within the CE level that can provide sufficient CE, where it may be assumed that the maximum uplink transmit power is used. The maximum uplink transmit power may be determined based on a nominal maximum transmit power (e.g., P EMAX , P powerciass , P CMAX_L , or P CMAX_H ), or P EMAX , P powerciass , P CMAX_L , and P CMAX_H Alternatively, the maximum uplink transmit power may be one or more combinations of P for a particular subframe i, e.g., P CMAX,c It may be (i).

[0228] PRACH power in CE mode, P PRACH is the maximum uplink transmit power (for example, P CMAX,c (i)) in normal mode, P PRACH is (for example, as shown in Equation 3) CMAX,c (i) may be determined as a function of one or more of PREAMBLE_RECEIVED_TARGET_POWER, path loss, or P PRACH , P CMAX,c (i),Path Loss (PL),N OFFSET and PREAMBLE_RECEIVED_TARGET_POWER, N OFFSETcan be determined as a function of at least one of the CE level, the PRACH format, and / or the number of iterations, for example, for the CE level.

[0229] Uplink transmit power P for CE mode PRACH , P PRACH =min{P CMAX,c (i),PREAMBLE_RECEIVED_TARGET_POWER+PL+N OFFSET}, where N OFFSET can be determined as a function of the CE level and / or the number of iterations for the CE level, for example. PREAMBLE_RECEIVED_TARGET_POWER can be determined as a function of the CE level and / or the number of iterations for the CE level, for example.

[0230] PREAMBLE_RECEIVED_TARGET_POWER may be determined as a function of the CE level, e.g., PREAMBLE_RECEIVED_TARGET_POWER=preamblelnitialReceivedTargetPower+DELTA_PREAMBLE+DELTA_OFFSET+(PREAMBLE_TRANSMISSION_COUNTER-1)*powerRampingStep, where DELTA_OFFSET may be a function of the CE level and / or a number of iterations, e.g., for the CE level, and / or a configuration that may be provided via higher layer signaling.

[0231] The CE level may be defined as or associated with one or more new PRACH preamble formats, and DELTA_PREAMBLE may be determined as a function of the PRACH preamble format. For example, CE level 1 may be defined as or associated with PRACH preamble format 5, and CE level 2 may be defined as or associated with PRACH preamble format 6. DELTA_PREAMBLE may be defined for the new PRACH preamble format, for example, as a function of the number of repetitions. PREAMBLE_RECEIVED_TARGET_POWER may be determined according to PREAMBLE_RECEIVED_TARGET_POWER=preamblelnitialReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_TRANSMISSION_COUNTER-1)*powerRampingStep.

[0232] Uplink transmit power P for CE mode PRACH , P PRACH =min{P CMAX,c (i), PREAMBLE_RECEIVED_TARGET_POWER+PL}, where PREAMBLE_RECEIVED_TARGET_POWER may be CE mode specific or CE level specific.

[0233] Maximum uplink transmit power (e.g. P CMAX,c (i)) may be used for a subset of CE levels, and the uplink transmit power at other CE levels may be P CMAX,c (i), may be determined as a function of at least one of the path loss, the number of iterations that may be used for the CE level, and PREAMBLE_RECEIVED_TARGET_POWER.

[0234] A maximum uplink transmit power may be assumed for the CE level selection, while the actual uplink transmit power for the PRACH preamble transmission may be calculated according to any of the equations described herein (whether numbered or not), such as, for example, Equation 3, which may be used for non-CE mode and / or legacy PRACH transmission. The maximum uplink transmit power for the CE level selection may be calculated according to any of the equations described herein (whether numbered or not), such as, for example, Equation 3, which may be used for non-CE mode and / or legacy PRACH transmission. EMAX , P powerciass , P CMAX_L , or P CMAX_H ), or the actual maximum uplink transmit power determined for a particular subframe (e.g., P CMAX,c (i)).

[0235] The WTRU may calculate or determine a number of iterations that may be needed, used, and / or sufficient, for example, for use with a CE level. The WTRU may calculate or determine the number of iterations, for example, when the WTRU can determine a CE level (e.g., a starting CE level) that may be for the PRACH transmission. To calculate the number of iterations, the WTRU may assume that a maximum transmit power (e.g., a nominal maximum uplink transmit power or an actual maximum uplink transmit power) may be used. The WTRU may determine a number of iterations that may be included in the number of supported iterations in the cell (e.g., a number that may be sufficient or the closest number equal to or greater than the iterations) and may use that number of iterations.

[0236] The WTRU may, for example, determine the minimum number of iterations supported in the cell, which may be greater than or equal to the number of iterations determined to be necessary or sufficient by the WTRU if the number of iterations calculated or determined by the WTRU is not available or supported in the cell.

[0237] For example, repetition numbers {5, 10, 20} may be supported in a cell, and the repetition numbers may be associated with CE levels {1, 2, 3}. If the number of repetitions calculated (e.g., as needed or sufficient) based on the maximum transmit power is not among the repetition numbers supported in the cell, a number of repetitions supported in the cell that is greater than the calculated number of repetitions may be selected, and the transmit power may be adjusted based on the selected number of repetitions that is not the maximum transmit power.

[0238] The CE level determination may be based on the uplink transmit power for the PRACH preamble transmission, which may be calculated or determined using any of the equations described herein (e.g., Equation 3) that may be used for non-CE mode and / or legacy PRACH.

[0239] The determination of the CE level may be based on the number of iterations that can at least achieve (eg, provide sufficient gain to achieve) the amount that the calculated power can exceed the maximum power.

[0240] The difference power P where the calculated PRACH power exceeds the maximum power E For example, P PRACH_REQ >P MAX If P E =P PRACH_REQ -P MAX where P MAX may be the maximum power (e.g., the nominal maximum uplink transmit power), and P PRACH_REQ P may be the required or calculated transmit power for the PRACH without repetition, which may be determined as PREAMBLE_RECEIVED_TARGET_POWER+path loss. E The number of iterations for, for example, 10log10(number of iterations) = P E If the calculated number of iterations is not an integer, the nearest integer greater than the calculated number of iterations may be selected and / or used.

[0241] In an embodiment, the WTRU may determine the starting CE level as the lowest CE level regardless of the downlink measurement results (e.g., may use a minimum amount of repetitions). For example, the WTRU may determine the uplink transmit power based on the downlink measurements and may use the lowest CE level for the PRACH preamble transmission. The WTRU may use (or assume) the lowest CE level when determining the transmit power. In another example, the WTRU may transmit the maximum uplink transmit power at the lowest CE level for the PRACH preamble transmission.

[0242] In another embodiment, the uplink transmit power for the PRACH preamble may be defined, calculated, and / or determined as a function of the number of repetitions. In an example, a CE level specific power offset may be used depending on the number of PRACH preamble repetitions. For example, the offset may be 10log10(number of repetitions), or subtract a scale factor multiplied by 10log10(number of repetitions). In another example, the uplink transmit power may be scaled by a CE level specific scalar (e.g., α). The scalar may be predefined depending on the CE level or configured by higher layer signaling.

[0243] In an embodiment, the WTRU may determine a mode of operation for a transmission, such as a PRACH transmission. The decision, which may be or may include a selection of normal mode operation or CE mode operation (and / or a CE level), may be based on one or more channels from or on which the WTRU receives (or receives) a MIB. For example, if the WTRU receives (or receives) a MIB from a legacy PBCH (e.g., only legacy PBCH), the WTRU may transmit (or begin transmitting) a PRACH preamble in normal mode operation. If the WTRU receives (or receives) a MIB from a coverage extended PBCH (CE PBCH), the WTRU may transmit (or begin transmitting) a PRACH preamble in CE mode operation. The legacy PBCH may be a PBCH without repetition in a radio frame. The CE PBCH may be a PBCH with repetition in a radio frame. In a CE PBCH, there may be two or more subframes (or transmissions) that include a PBCH in a radio frame. In a legacy PBCH, there may be one (e.g., only one) subframe containing a PBCH per radio frame. The legacy PBCH, which may be transmitted in one of the subframes in a radio frame, may be included or considered as one of the repetitions for the CE PBCH, for example, if the CE PBCH may be the same as (e.g., a repetition of) the legacy PBCH. If the WTRU receives (e.g., successfully receives) the MIB from the PBCH using at least one of the repetitions of the PBCH in a radio frame (e.g., other than the legacy transmission), the WTRU may transmit the PRACH preamble using a CE mode of operation. If the WTRU receives (e.g., successfully receives) the MIB from the PBCH without using any repetitions of the PBCH in a radio frame, the WTRU may transmit the PRACH preamble using a normal mode of operation.The WTRU may determine a mode of operation for PRACH transmission based on at least one or more of the downlink measurements, the channel on which the WTRU can (or may be) receiving the MIB (e.g., legacy PBCH or CE PBCH), and the time that may be required and / or used for initial synchronization and / or MIB acquisition. For a CE PBCH, each repetition of the PBCH may be referred to as a PBCH.

[0244] The WTRU may determine the CE level based at least on the number of PBCH repetitions (e.g., in a frame and / or set of frames, such as frames within the TTI of the MIB) that it requires or may use to successfully receive the MIB.

[0245] In another embodiment, the WTRU may make a RACH CE decision, which may include determining at least one of whether to use CE or normal mode (e.g., for an RA procedure), a CE level and / or a PRACH repetition level (e.g., for an RA procedure), a PRACH resource in time (e.g., subframe) and / or frequency, and a PRACH preamble index for a CE mode RACH procedure. The WTRU may make and / or use at least measurements to make the RACH CE decision. The WTRU may receive and / or use at least information, e.g., from an eNB, to make the RACH CE decision.

[0246] The WTRU may use the received signal strength of the synchronization signals, eg, the PSS and / or SSS, to make the RACH CE decision.

[0247] The WTRU may make a RACH CE decision using the number of PSS and / or SSS that have been accumulated (or that it may accumulate) in time. For example, the WTRU may determine (e.g., by counting or otherwise tracking) the number of subframes over time or total time that the WTRU needs or may use to properly acquire a PSS and / or SSS, and may use that number or time to make a RACH CE decision.

[0248] The WTRU may use the number of iterations that have accumulated (or that it may accumulate) in time to properly receive and / or decode the PBCH and / or MIB that may be included in the PBCH to make a RACH CE (e.g., RACH CE mode and / or level) decision. For example, the WTRU may determine (e.g., by counting or otherwise tracking) the number of PBCHs that it may need or use in a MIB TTI (e.g., 40 ms cycle) to properly decode the PBCH and / or MIB. As it "keeps attempting" a PBCH decoding method (e.g., the WTRU may keep attempting over multiple periods of a MIB TTI to successfully decode the PBCH), the WTRU may determine (e.g., by counting or otherwise tracking) the number of MIB TTI (e.g., 40 ms) PBCH cycles that it may need or use to properly decode the PBCH, and may use that number or time to make a RACH CE (e.g., RACH CE mode and / or level) decision.

[0249] The WTRU may make the RACH CE decision using a means by which the PBCH and / or the MIB (which may be included in the PBCH) may be correctly received and / or decoded, e.g., regardless of whether a repetition burst for coverage extension may be needed and / or used. For example, the WTRU may decide to operate in CE mode for the RACH procedure if the PBCH may be decoded using a repetition burst for coverage extension and / or if the WTRU was not able to properly decode the PBCH during a normal repetition cycle (e.g., a 40 mm repetition cycle), which may include one (e.g., only one) PBCH per radio frame.

[0250] The WTRU may make a RACH CE decision using the number of iterations it may require to correctly receive and / or code a SIB or coverage extension specific SIB that may be transmitted by an eNodeB, e.g., with a particular SIB time window and / or scheduling. For example, the WTRU may determine (e.g., by counting or otherwise tracking) the number of repetitions of a SIB that may be used by the WTRU to properly decode the SIB in one or more scheduled SIB time windows to make a RACH CE (e.g., RACH CE mode and / or level) decision.

[0251] The WTRU may make a RACH CE (e.g., RACH CE mode and / or level) decision using information about the CE mode and / or level that it used when last served by a particular cell or a neighboring cell. For example, the WTRU may store information about the CE mode and / or level usage for a particular cell and use that information to determine the CE mode and / or level when the WTRU can select that cell at another (e.g., later) time.

[0252] The WTRU may receive, e.g., in an RRC connection release message, the CE mode and / or CE level for one or more cells, such as the current serving cell and / or another (e.g., neighboring) cell, e.g., during its transition from connected mode to idle mode. The CE mode and / or CE level may be used or intended to be used by the WTRU when it selects the same cell or another cell, e.g., to remain in idle mode. The WTRU may receive the CE mode and / or level information upon a connection establishment procedure failure (e.g., rejection). The WTRU may use the information for or during a retry of connection establishment in the same cell or another cell.

[0253] A PRACH attempt may refer to a set of PRACH preamble transmissions that may include an initial PRACH preamble followed by a preamble repetition in a particular subframe that may be defined for a CE mode PRACH procedure before the WTRU can attempt to monitor and / or decode, for example, a corresponding RAR from an eNodeB. A PRACH preamble retransmission or retry may refer to a PRACH preamble retransmission and subsequent preamble repetitions that may follow a failed PRACH procedure.

[0254] PRACH power ramping may be provided and / or used.

[0255] In an embodiment, the WTRU may apply independent power ramping for the PRACH procedure for CE mode operation. The WTRU may receive independent power ramping parameters for the PRACH for CE mode operation from the eNodeB, which may differ from normal mode operation. For example, CE mode-specific power ramping parameters may be broadcast, for example, by the eNodeB in a SIB, such as SIB2 or a coverage-enhanced (CE)-SIB. The WTRU may receive one or more power control and / or power ramping-related parameters for the CE mode, which may be specific to the CE mode.

[0256] The WTRU may receive one or more PRACH power control (e.g., open loop power control) parameters, such as an initial power value (e.g., preambleInitialReceivedTargetPower), a power ramping value or step (e.g., powerRampingStep), and / or a number of ramping attempts (e.g., PreambleTransMax), which may be specific to a CE mode PRACH preamble transmission. For example, a WTRU that may perform a CE mode RACH may apply a CE power ramping value to each repetition of the PRACH preamble in a single RACH preamble transmission attempt. The WTRU may maintain the same power (e.g., not increment by a ramping step) for each repetition, or may ramp the power (e.g., increment by a ramping step) for each repetition (or for each group of repetitions). As another example, the WTRU may apply a power ramping value to the preamble transmission power for each initial preamble retransmission attempt, and may apply the same PRACH preamble transmission for each repetition in the preamble attempt. The WTRU may also apply a power ramping value jointly to the preamble repetitions and preamble retransmission attempts. Separate ramping values ​​may be provided and / or used for the preamble repetitions and preamble retransmission attempts.

[0257] The WTRU may receive separate PRACH power control (e.g., open loop power control) parameters for each CE level that the WTRU may apply to the preamble transmit power depending on the CE level that the WTRU can use for PRACH attempts. In an example, the WTRU may receive PreambleTransMax for each CE level, and the WTRU may attempt PRACH preamble transmissions at the particular CE level up to PreambleTransMax. If the WTRU does not receive a corresponding RAR at a particular CE level with a maximum number of attempts (e.g., PreambleTransMax), the WTRU may increase the CE level to the next CE level with a larger number of iterations. In another example, the WTRU may determine the Nth iteration at a particular level based on, for example, an indication or configuration from the eNB. ATTEMPTS The CE level may be or may need to be increased to the next CE level after the PRACH preamble transmission attempt, where N ATTEMPTS N may be one or more of: (i) a predefined number; (ii) a configured number that may be provided via higher layer signaling; (iii) determined as a function of one or more parameters such as power ramping value, initial power value, number of ramping attempts, etc.; (iv) determined by one or more parameters including number of iterations per CE level, downlink measurements, and nominal maximum transmit power. ATTEMPTS may be CE level dependent or common to all CE levels.

[0258] The WTRU may receive a PRACH maximum power usage indication (or configuration) from the eNodeB, which may, for example, inform the WTRU to transmit the PRACH at maximum power for one or more (e.g., all) CE levels and / or CE modes. The indication may be provided and / or received in higher layer signaling, such as broadcast signaling. A WTRU that receives an indication to transmit at maximum power may transmit the initial PRACH preamble and subsequent (e.g., all subsequent) preamble repetitions at the maximum allowed transmit power for the PRACH preamble, which may be determined by the WTRU based on various factors, such as, for example, the WTRU power class, a maximum value that may be provided by the eNodeB, and allowed reductions such as MPR and A-MPR.

[0259] The WTRU may receive an indication of maximum power usage, which may indicate to use (or whether to use) maximum power for all CE levels, or a separate indication may be provided for each CE level. The default (e.g., no indication) may be to not use maximum power and ramp instead. Based on the CE levels the WTRU can use for PRACH transmissions, the WTRU may transmit at maximum power or ramp power accordingly (e.g., using power control, which may be open loop and / or based on RSRP and / or path loss as described in one or more equations herein).

[0260] The WTRU may receive an indication of the maximum power usage per CE level at which maximum power may be used. A default (e.g., no indication) may mean not using maximum power and ramping instead. Based on the CE level the WTRU can use for PRACH transmission, the WTRU may transmit at maximum power or ramp power accordingly (e.g., using power control, which may be open loop and / or based on RSRP and / or path loss as described in one or more equations herein).

[0261] In an example, the WTRU may receive an indication to transmit using maximum power for a PRACH preamble for one CE level, e.g., CE level 2 (e.g., a level for 10 dB extension), and may transmit at maximum power when using that CE level for a PRACH transmission. The WTRU may not receive an indication for another CE level, e.g., CE level 1 (e.g., a level for 5 dB extension), or may receive an indication not to use maximum power for that CE level. For normal mode and its CE level (e.g., CE level 1), the WTRU may use power control, which may be open loop and / or may be based on path loss for RSRP and / or PRACH preamble transmission as described in one or more equations herein.

[0262] The WTRU may receive, e.g., from the eNodeB, an offset value that the WTRU can apply to the PRACH preamble power when transmitting a preamble in CE mode. The WTRU may receive the offset in the system information for the cell, e.g., SIB2 or a CE-specific SIB. The WTRU may receive an offset to apply per CE level or a single offset for all CE levels. The WTRU may apply an offset to the preamble transmit power determined in the PRACH power control, which may be based on the preamble transmit power and / or power ramping parameters, and / or RSRP and / or path loss as described in one or more equations herein.

[0263] The offset may be determined by the WTRU (e.g., alternatively or additionally) based on a number of repetitions (e.g., for a PRACH transmission) that may correspond to a CE level. The WTRU may determine the offset from 10log10(number of repetitions). The WTRU may add or subtract the offset.

[0264] The PRACH power control that may be performed by the WTRU may be or may be considered to be open loop power control, for example, since no power adjustment feedback is received from the eNB.

[0265] A coverage-extended RA procedure may be used, which may include one or more (e.g., four) parts, steps, or messages, e.g., msg1 (e.g., RA preamble), msg2 (RAR), msg3 (scheduled UL transmission), and / or msg4 (contention resolution), which may be similar to those of a normal RA as shown in the example of FIG. 2 and / or may be extended versions thereof.

[0266] The WTRU may perform a PRACH preamble transmission. The WTRU may receive PRACH configuration information from at least one normal SI-message, which may be carried via a non-coverage extended SIB, and / or a CE SI-message, which may be provided and / or used for the CE mode. The WTRU may receive one or more PRACH resources, which may be used for the CE mode and / or may be according to a CE level. For example, the WTRU may receive two coverage extended PRACH resources at CE level 1 and CE level 2, respectively. The WTRU may determine the type of PRACH preamble transmission between a normal PRACH preamble and a CE PRACH preamble based on a channel condition or a predefined WTRU behavior.

[0267] The RAR for the CE mode and / or one or more CE levels may be provided and / or used, for example, when the WTRU may transmit a CE mode or CE level PRACH preamble.

[0268] In an embodiment, the RA-RNTI may be allocated, determined, provided, and / or used with an offset value. For example, if the WTRU transmits a normal PRACH preamble, the WTRU may monitor a PDCCH (or EPDCCH) that may be scrambled by the RA-RNTI, where the RA-RNTI may be determined by or based on RA-RNTI=1+t_id+10*f_id, where f_id may be 0, e.g., for FDD, and t_id may be a value in a range such as 0=<1 t_id=<9. If the WTRU transmits a CE mode or level PRACH preamble, the WTRU may monitor a PDCCH (or EPDCCH) that may be scrambled by the RA-RNTI, where the RA-RNTI may be determined by or based on RA-RNTI=1+t_id+delta_offset+10*f_id. Alternatively, the RA-RNTI may be calculated as RA-RNTI=11+CE level+10*f_id, where the CE level may be one of a set such as {1,2,3}. delta_offset may be a predefined number such as delta_offset=10. Alternatively, delta_offset may be a function of at least one of the system bandwidth, the number of CE levels supported for the CE mode PRACH, and / or the number of iterations for the CE (e.g., CE mode and / or CE level) PRACH.

[0269] In another embodiment, the (E)PDCCH, which may indicate a grant for the RAR, and / or the PDSCH, which may carry the RAR, may be transmitted repeatedly within a time window, which may be predefined. The time window may be located after the last subframe (e.g., several subframes) of the CE PRACH preamble transmission. The WTRU that transmitted (or will transmit) the CE PRACH preamble may monitor the (E)PDCCH and / or the PDSCH, which may carry the RAR with repetitions, which may be based on the configured and / or used RA-RNTI. An RA-RNTI, which may be equal to 1+t_id+delta_offset+10*f_id, may be used. Alternatively, an RA-RNTI, which may be equal to 11+CE level+10*f_id, may be used. The number of time windows and / or repetitions for the PDCCH (or EPDCCH) and / or PDSCH, which may carry the RAR, may be a function of the CE mode and / or one or more CE levels (e.g., respectively).

[0270] The time window and / or number of repetitions for the PDCCH (or EPDCCH) and / or PDSCH that can carry the RAR can be configured separately and / or different. The number of repetitions for the PDCCH (or EPDCCH) and / or PDSCH that can carry the PRACH preamble transmission, the RAR can be configured separately and / or different. One or more of the messages that can be used for the RA procedure can have and / or use and / or be configured for a different number of repetitions for the same mode or CE level.

[0271] In another embodiment, a configured and / or predefined PDSCH resource may be used for the RAR. For example, if the WTRU transmits a CE PRACH preamble, a corresponding PDSCH resource that may include the RAR may be configured and / or predefined for eNB transmission and / or WTRU reception.

[0272] A set of physical resource blocks (PRBs) may be used for the PDSCH, which may carry the RAR. The set of PRBs may be transmitted, for example, repeatedly across multiple subframes. The multiple subframes may be referred to as a time window. In an example, the start subframe of the time window may be defined as n+k, where n may be the last subframe of the repetition of the CE PRACH preamble transmission, and k may be a positive integer that may be predefined (e.g., k=4), configured, or a function of the TDD UL / DL configuration.

[0273] The set of PRBs that may be used for a PDSCH that may carry the RAR, and the frequency locations of the set of PRBs, may be configured and / or predefined.

[0274] In another embodiment, a PDSCH resource may be used to transmit an RAR without an associated PDCCH (or EPDCCH). The PDSCH resource location may be defined as a function of the RA-RNTI used. For example, RA-RNTI=1+t_id+delta_offset+10*f_id may be used for or by a WTRU that transmits (or has transmitted) a CE PRACH preamble. The WTRU may derive or determine, for example, based on the RA-RNTI, which PDSCH resource the WTRU may need to receive.

[0275] The number of PDSCH resources (e.g., up to 10) that can carry the RAR may be defined and / or determined depending on the RA-RNTI. The PDSCH resources may be one-to-one mapped. The WTRU may monitor and / or attempt to decode the PDSCH resources based on the RA-RNTI (e.g., its value).

[0276] In an embodiment, the RAR for a CE PRACH preamble transmission may include an index of a random access preamble sequence that the network may have detected, and / or a timing correction. The RAR may include a scheduling grant, for example, for a UL transmission of msg3 on the PUSCH. The RAR may include, for example, a number of repetitions that the WTRU uses for the PUSCH transmission along with or as part of (e.g., attached to or included in) the scheduling grant. The scheduling grant may include a starting and / or ending subframe for the PUSCH transmission, and / or parameters from which the WTRU may derive or determine the starting and / or ending subframe for the PUSCH transmission. The RAR may include a TC-RNTI. The RAR may include a power offset that the WTRU may use to adjust the transmit power for the PUSCH transmission, and / or a power ramp-up delta of the RA procedure that may affect the PUSCH power. The WTRU may transmit on the UL on a scheduled resource, for example, if the WTRU can receive (e.g., successfully) an RAR that may be directed to it. The WTRU may adjust the timing according to the timing correction and / or adjust the power according to the power offset.

[0277] In an embodiment, the network (eNodeB) can send a contention resolution message on the downlink based on the C-RNTI, for example on the PDCCH (or EPDCCH). The PDCCH (or EPDCCH), which may be scrambled with the C-RNTI, can be transmitted across multiple subframes.

[0278] A WTRU that transmits (or has transmitted) a PUSCH with a TC-RNTI (e.g., in RACH msg3) may monitor a PDCCH (or EPDCCH) that may be scrambled with the TC-RNTI in a configured and / or predefined time window. Within the time window, the WTRU may expect that a PDCCH (or EPDCCH) that may be scrambled with the TC-RNTI may be transmitted repeatedly at configured and / or predefined positions. For example, a PDCCH (or EPDCCH) that may be scrambled with the TC-RNTI may be transmitted in a configured and / or predefined set of CCEs in a common search space.

[0279] A WTRU transmitting (or having transmitted) RACH meg3 in CE mode may monitor a PDCCH (or EPDCCH) that may be scrambled with the TC-RNTI in a PDCCH (or EPDCCH) common search space, e.g., with or using CE mode. A PDCCH (or EPDCCH) common search space with or using CE mode may have one or more CE PDCCH (or EPDCCH) candidates. A CE PDCCH (or EPDCCH) candidate may be defined as or by an aggregation level and / or a repetition level. The WTRU may monitor a PDCCH (or EPDCCH) that may be scrambled with the TC-RNTI, e.g., to receive a DL grant for a contention resolution message.

[0280] In another embodiment, the network (eNB) can send the contention resolution message on the downlink based on the PDSCH without an associated PDCCH (or EPDCCH), in which case the location of the PDSCH that can contain the contention resolution message can be configured based on the uplink scheduling grant for the RACH msg3.

[0281] Link adaptation of the PDSCH and / or PUSCH may be provided and / or used.

[0282] The WTRU may receive an indication from the eNB regarding the mode of operation (e.g., normal mode operation or CE mode operation) and / or the CE level (e.g., repetition level). The WTRU may receive the indication dynamically, e.g., via physical layer signaling, such as via a DCI format. For example, the WTRU may be provided with an indication (e.g., explicit) in a DCI format that may grant, e.g., a UL PUSCH and / or a DCI format that may assign a DL PDSCH transmission. The indication may be an (e.g., absolute) repetition level (which may be or correspond to a number of repetitions). The indication may be, e.g., a relative repetition level, such that the repetition level may be determined from a previous repetition level plus (or minus) a relative repetition level provided, e.g., in a DCI. For example, the WTRU may be configured with a repetition level of N (e.g., 4), which may be in order of least to most repetitions. The DCI (or other mechanism) may include a dynamic indication that the repetition level may (or should) be increased or decreased. For example, the indicator may be two bits and have the following meanings: "00" - decrease the repeat level by 1, "01" - maintain the repeat level, "10" - increase the repeat level by 1, and "11" - increase the repeat level by 2.

[0283] It is contemplated that the terms CE level, iteration level, and number of iterations may be used interchangeably. Additionally, it is contemplated that the terms number of iterations and number of iterations may be used interchangeably.

[0284] For a UL transmission, for example, when a repetition level may be received along with the UL grant, the WTRU may apply the received repetition level starting with the PUSCH transmission for which the UL grant was received.

[0285] For UL transmission, for example, when a repetition level may be received along with a DL grant, the WTRU may apply the received repetition level starting with a PUSCH (or other UL) transmission, which may be at least a certain number k of subframes after the subframe in which the DL grant may be received (or may have been received). For example, k may be 4 (e.g., for FDD). In another example, k may be a function of the TDD UL / DL configuration.

[0286] The indication of the CE level in the DCI may be via a DCI format (e.g., an existing legacy DCI format), which may have one or more bits that may be used (or may be intended to be used) for non-CE mode as one use and CE mode as another use.

[0287] FIG. 6 illustrates an example method for setting a CE level (or repetition level). The WTRU determines a level of coverage extension in step 602, e.g., using one or more of the techniques described herein. In step 604, the WTRU receives a DCI message, e.g., from an eNodeB. If the WTRU is in a coverage extension mode (step 606), the WTRU uses information in the DCI message in step 608 to set a repetition level for one or more shared channels, such as a PDSCH and / or a PUSCH. If the WTRU is not in a coverage extension mode, the bits of the DCI message may be interpreted in step 610 according to known techniques, such as known LTE or LTE-A techniques (e.g., as may be described in Releases 8, 9, and / or 10). DCI, DCI format, and DCI message may be used interchangeably.

[0288] The TPC commands may be provided and / or used to indicate a CE or repetition level for PUSCH coverage extension, for example.

[0289] UL transmissions on the PUSCH may be granted via a DCI format, such as DCI format 0 or 4. Such DCI may include a field for TPC commands. A WTRU in CE mode operation may assume or expect, for example, that TPC commands may be used (e.g., may only be used) to dynamically indicate the repetition level (e.g., in an absolute or relative / accumulated manner) if or when the WTRU can (or may be configured to) operate (e.g., transmit) at a fixed power for the CE mode or for one or more CE or repetition levels. In an example, the WTRU may operate (e.g., transmit) at a particular power level (e.g., full power) for any repetition level. In another example, the WTRU may be semi-statically configured with one or more specific UL transmit powers that may be used for one or more (e.g., each) repetition levels. In another example, the transmit power may depend on the subframe in which the UL transmission occurs. For example, in a first subset of subframes, transmissions for the repetition levels may use a first set of transmit powers (which may correspond, for example, to a CE level or a set of repetition levels), and in a second subset of subframes, transmissions for the repetition levels may use a second set of transmit powers (which may correspond, for example, to a CE level or a set of repetition levels). The meaning of the TPC command (e.g., indicating a change in PUSCH transmit power or a change in repetition level) may be set semi-statically, possibly via an RRC configuration. Repetition level and number of repetitions may be used interchangeably.

[0290] The TPC command may be used to indicate at least one of a change in UL transmit power or a repetition level (or a change therein). For example, the WTRU may be pre-configured with a vector (or set) of PUSCH transmit powers and repetition levels. The TPC command may indicate to the WTRU whether it should move to a different PUSCH transmit power and / or repetition level (e.g., in an absolute value, such as by pointing to a vector entry, or in a relative value, such as by indicating a shift in a vector entry). The TPC command indicates no change in the PUSCH transmit power and / or repetition level (e.g., in an absolute value, such as by pointing to a vector entry, which may be the same as the current value or vector, or in a relative value, such as by indicating no or zero change or shift in the value of the vector entry).

[0291] As an example, a WTRU may be configured with transmit powers such as A, B, and C, and the WTRU may be configured with repetition levels 1, 2, and 3. A vector of PUSCH transmit powers and repetition levels may be written as 1A, IB, 1C, 2A, 2B, 2C, 3A, 3B, 3C. In such an example, if a TPC command indicates a relative shift of +2, the WTRU may move two levels to the right, and a relative shift of -1 may represent a move one level to the left. For example, if a WTRU is transmitting at repetition level 2 and power level B and receives a TPC command indicating a shift of +2, the WTRU may change its next transmission to repetition level 3 and power level A. The power level / repetition level vector may not (or need not) include all possible combinations of power levels and repetition levels.

[0292] The meaning of the TPC commands may depend on whether the WTRU is configured for (using) a CE mode. For example, the TPC commands may map to one interpretation (e.g., relative power change) when in a non-CE mode, and another interpretation (e.g., relative or absolute repetition level) when in a CE mode. In another example, in a CE mode, the TPC commands may be (or always be) more than one bit, with some bits mapping to absolute or relative PUSCH transmit power and other bits mapping to absolute or relative repetition levels. The repetition level may be configured semi-statically, and / or the interpretation of the TPC command table may depend on the repetition level (or CE level). For example, in one repetition level (or CE level), a TPC command with two bits may be interpreted as "-1,0,1,2", in another repetition level (or CE level), the two bits of the TPC command may be interpreted as "-2,0,2,4", etc.

[0293] 7 shows an example method for setting the CE level (or repetition level). After the WTRU receives a TPC command in step 704, the WTRU determines whether the WTRU is in CE mode in step 706. If the WTRU is in CE mode, the WTRU uses the information in the TPC to set the repetition level for the PUSCH and / or PDSCH in step 708. If the WTRU is not in CE mode, the WTRU employs conventional techniques, e.g., uses the information in the TCP command to set the transmitter power level in step 710.

[0294] The applicability of TPC commands to power levels, repetition levels, or both may be determined at least in part by the configuration (or use) of CE mode. For example, a WTRU that has CE mode on (or may be configured for and / or operating in CE mode) may interpret TPC commands as applicable to (or only to) the repetition level, or to both the power level and the repetition level.

[0295] The applicability of TPC commands to power levels, repetition levels, or both may be determined at least in part by an explicit indication. For example, the WTRU may receive an indication regarding the meaning of TPC commands that may be applied, e.g., when configured in CE mode. In another example, the WTRU may receive an indication regarding the meaning of TPC commands that may be applied, e.g., when configured in CE mode and / or when operating in CE mode. The indication may be provided via higher layer signaling, such as broadcast or dedicated signaling, from the eNB.

[0296] The applicability of a TPC command for a power level, a repetition level, or both may be determined at least in part by the subframe number. For example, a TPC command received in subframe n for a PUSCH transmission in subframe n+k may have different meanings depending on the values ​​of n, k, or both, e.g., for CE and non-CE modes.

[0297] The applicability of TPC commands to power levels, repetition levels, or both may be determined at least in part by the DCI format. For example, a new DCI format may be designed for CE mode transmissions. In such a DCI format, TPC commands may be applicable to combinations of transmit power and repetition levels in the manner described herein.

[0298] The applicability of the TPC command to a power level, a repetition level, or both may be determined at least in part by the resource on which the DCI carrying the TPC is transmitted (or was transmitted). For example, the search space (e.g., WTRU-specific or common), the type of PDCCH (regular PDCCH or EPDCCH), or the EPDCCH resource may (e.g., implicitly) indicate the meaning of the TPC command to the WTRU.

[0299] In CE mode, the WTRU may receive the (E)PDCCH in the DCI that it can monitor. and the associated PDSCH and / or PUSCH The iterations that can be used for Number The DCI may be provided by and / or received from the eNB. In an example, a parameter to indicate the number of repetitions for the (E)PDCCH, e.g., N EPDCCH_REP , and another parameter to indicate the number of repetitions for the associated PDSCH or PUSCH, e.g., N DATA_REP may be received from a DCI (e.g., a monitored DCI). In another example, a single parameter may be used to indicate the number of repetitions for the (E)PDCCH and associated PDSCH or PUSCH.

[0300] In an embodiment, some parameters of the PUSCH grant may be restricted in CE mode (e.g., limited or not used in their typical or legacy use). Such restrictions may enable the eNodeB to indicate the repetition level by reusing some of the bits allocated in the DCI.

[0301] For example, the number of supported carriers may be limited in CE mode to allow at least a portion of the carrier indicator field to be used for CE mode. Part or all of the carrier indicator field may be reused to indicate a repetition level or a meaning of a TPC command. In another example, multiple carriers (e.g., carrier aggregation) and the carrier indicator field may not be used in CE mode. If the WTRU is configured for multi-carrier operation (e.g., multiple carriers are configured) in normal mode operation, the PCell in normal mode operation may be used for single-carrier operation in CE mode operation. Alternatively, the WTRU may receive an indication from the eNB that identifies which carriers in the configured multiple carriers the WTRU can use in CE mode operation. Upon or after switching to CE mode, the WTRU may switch from multi-carrier operation to single-carrier operation and use the PCell or a designated cell as its single serving cell.

[0302] The modulation and coding schemes (MCS) and / or redundancy versions supported and / or used in CE mode may be restricted. Some MCS levels and / or redundancy versions may be restricted in CE mode operation. For example, the MCS table may be interpreted differently by the WTRU in CE mode operation and / or each MCS level may be assigned a repetition level. In another example, a subset of modulation orders in the MCS table may be used in CE mode operation, and the remainder (e.g., of the entries in the table) may be reused to indicate the number of repetitions.

[0303] Resource block allocation may be restricted in CE mode, e.g., some RRBs and / or resource allocation sizes may be restricted, and allocation may be used to indicate (e.g., implicitly) a repetition level.

[0304] In CE mode, the CSI request may be limited to a one-bit field, with the other bits being used to indicate the repetition level to the WTRU (or to indicate the meaning of the TPC command to the WTRU).

[0305] The number of layers may be limited in CE mode. For example, DCI format 4 allows transmission on up to a certain number of antenna ports (e.g., 4 antenna ports), some of which may not be used in CE mode. Some elements of the precoding information field table may be restricted and / or reinterpreted to indicate the repetition level.

[0306] One or more restrictions on or that may affect a DCI format or field (e.g., as described herein) may depend on a repetition level (e.g., in CE mode). For example, a WTRU may be configured (e.g., pre-) with and / or use a repetition level, and the meaning of the MCS field in the DCI may depend on the repetition level.

[0307] A new DCI format may be designed with limited or restricted values ​​for some of the fields, thereby allowing for the inclusion of a new field that may indicate (e.g., explicitly) the repetition level for the PUSCH transmission.

[0308] In a DCI granting a PDSCH, the TPC command (e.g., command bit) may be intended for use with HARQ feedback on the PUCCH for DL ​​allocation, etc. A WTRU in CE mode may reinterpret or be configured to reinterpret the TPC command as a repetition level indicator for the assigned PDCCH and / or PUCCH. The TPC command may indicate to the WTRU a combination of repetition levels for the assigned PDCCH and / or PUCCH combined with a power level for the PUCCH, e.g., in a manner similar to that described herein for the PUSCH. For example, the WTRU may be configured with a vector of combinations of repetition values ​​for the PDCCH, repetition values ​​for the PUCCH, and power levels for the PUCCH, and the TPC command may be mapped to one of the vector values ​​(e.g., in an absolute or relative / accumulated manner). In an example, for each PUCCH repetition level, the WTRU may use a fixed (and possibly different) transmit power. The TPC command may map to (e.g., only to) the PDSCH and / or PUCCH repetition levels. In another example, the repetition level and transmission level of the PUCCH may be fixed (and possibly different) for each PDSCH repetition level, and the TPC commands may be mapped to (e.g., mapped only to) the PDSCH repetition level.

[0309] To determine the meaning of the TPC command (e.g., whether it may be intended to be used for PUCCH power control, PUCCH repetition level, and / or PDSCH repetition level) and / or to determine the PUCCH repetition level and / or PDSCH repetition level, the eNodeB and / or WTRU may use at least one of: (i) whether a PDCCH or EPDCCH is used, (ii) the EPDCCH resource used, (iii) the (E)PDCCH search space used (e.g., whether it is WTRU-specific or common), (iv) the values ​​of n, k, or n+k for the grant in subframe n and the HARQ feedback in subframe n+k, (v) the DCI format used, (vi) new fields in existing or new DCI formats for CE mode, (vii) RRC signaling, and / or (viii) whether the WTRU is in CE mode.

[0310] In CE mode, the WTRU may have restrictions (e.g., limitations) on some parameters of the DL allocation. The meaning of at least one of the fields in the DL allocation DCI may be reinterpreted to indicate the repetition level (for PDSCH and / or PUCCH) and / or the meaning of the TPC command, e.g., by reusing bits. For example, some or all of the carrier indicator field (CIF) may be reused and / or reinterpreted. The number of carriers may be limited in CE mode, and some values ​​of the CIF may be limited and / or reused and / or reinterpreted. In another example, the HARQ-ACK resource offset may be reused in the PDCCH as a flag, e.g., in CE mode (e.g., to indicate the repetition level or the TPC command meaning). In another example, the resource block allocation may be limited or limited in CE mode. Some values ​​of the PRB and / or allocation size may be limited, and some bits of this field may be reused and / or reinterpreted. In another example, the transport block to codeword swap flag may be reused and / or reinterpreted. In another example, some elements of the MCS table may be reused and / or reinterpreted. In another example, precoding information may be restricted in CE mode. Some precoders and / or layers and / or transmission ranks may be restricted and some of the fields may be reused and / or reinterpreted.

[0311] For CRS-based demodulation of the PDSCH and / or CSI feedback measurements, the WTRU may be configured with a power offset assumption between the CSR and the PDSCH. The WTRU may be configured with multiple such power offsets, e.g., one for each repetition level. Thus, once (or subsequently) configured with a new PDSCH repetition level, the WTRU may use a new appropriate power offset value. The CRS vs. PDSCH power offset value may be configured, e.g., simultaneously, with the (e.g., any) new repetition level.

[0312] The WTRU may report a recommended repetition level for the PDSCH, for example, in a new CSI feedback report type (which may be or may include a repetition level indicator, for example). Such a report may be transmitted periodically or aperiodically. For example, when (or only when) a new repetition level may be needed or requested, for example, by the WTRU, the WTRU may autonomously report the new repetition level, for example, in at least the (e.g., next or nearest) CSI feedback time / frequency resource that may be configured for the new CSI feedback report. A flag (e.g., a reserved bit in the CSI feedback) may be used to indicate whether the CSI feedback may include a (e.g., updated) repetition level recommendation. In an example, if a new repetition level (or an updated repetition level) is included in the CSI feedback, the current and / or subsequent CSI feedback (e.g., CQI, PMI, and / or RI) that may be determined and / or reported by the WTRU may be based on the new repetition level (e.g., based on the PDSCH with the assumed new repetition level). In another example, the CSI feedback may be based on a repetition level configured and / or used (e.g., by the NodeB) for the PDSCH, which may not be related to a (e.g., new) repetition level that may be recommended by the WTRU. In another example, the repetition level that may be assumed for the CSI feedback may be determined as a function of at least one of the subframe position, the subframe type, and the subframe configuration. In another example, the eNodeB may configure the WTRU with multiple CSI processes, where each process may be configured with a separate and / or different repetition level assumption.

[0313] A PUCCH resource allocation for CE mode may be provided and / or used.

[0314] In an embodiment, the PUCCH resource may be dynamically allocated as a separate PUCCH resource for the CE mode. In an example, the PUCCH resource is

[0315]

number

[0316] where n CCE is the number of initial CEEs used for transmission of the corresponding DCI allocation (e.g., the lowest CCE index that can be used to construct a PDCCH),

[0317]

number

[0318] can be configured by a higher layer, and the PUCCH resource in the k-th subframe within the repetition window is

[0319]

number

[0320] can be assigned based on

[0321]

number

[0322] For example, the PUCCH repetition window may be defined as 20 subframes, and a WTRU that can transmit a coverage extended PUCCH may allocate a PUCCH resource in the first subframe in the PUCCH repetition window.

[0323]

number

[0324] , and the PUCCH resource in the second subframe

[0325]

number

[0326] etc. can be used.

[0327] One or more of the subframes in the PUCCH repetition window may not have an allocated PUCCH. The one or more subframes that do not include an allocated PUCCH resource may be defined as a function of at least one of the CE level, subframe number, C-RNTI, and / or number of repetitions for the corresponding PDSCH or (E)PDCCH, which may be predefined, configured via a higher layer, or configured and / or used for the uplink and / or downlink. k may be used as the kth repetition subframe. For example, if 10 PUCCH repetitions are used in a PUCCH repetition window of 20 subframes, the second repetition in the PUCCH repetition window is the kth repetition, regardless of the subframe number in the PUCCH repetition window.

[0328]

number

[0329] It could be.

[0330] n CCE,m m may be defined as the first CCE in the mth subframe within the PDCCH repetition window (e.g., the lowest CCE index used for the associated PDCCH received for the corresponding PDSCH reception). If the number of repetitions is the same for the PDCCH and PUCCH, m=k may be assumed.

[0331] For example, to avoid collisions between PUCCH resources in normal mode and PUCCH resources in coverage extended mode,

[0332]

number

[0333] may be defined for PUCCH resource allocation in CE mode.

[0334]

number

[0335] may be at least one of predefined as a fixed number, configured via higher layer signaling, and / or defined (e.g., implicitly) as a function of at least one of the downlink system bandwidth, the CE-level, and / or the C-RNTI.

[0336]

number

[0337] teeth,

[0338]

number

[0339] When the WTRU is configured in normal mode,

[0340]

number

[0341] and when the WTRU is configured in CE mode,

[0342]

number

[0343] The PUCCH can be transmitted using the

[0344] The PUCCH resource in the kth subframe in the repetition window is

[0345]

number

[0346] where n ID may be defined as a function of one or more of the system parameters and / or the WTRU parameters. ID may be configured via higher layer signaling in a WTRU-specific manner. In this case, ID may be defined as a function of the WTRU-ID (e.g., C-RNTI). For example, modulo arithmetic may be used to ID =n RNTI modn mod And so on, n RNTI (e.g. C-RNTI) and n mod nID can be determined using mod may be a predefined number, and n mod may be configured via higher layer signaling, or mod may be defined as a function of the system bandwidth.

[0347] A higher layer configured PUCCH resource may be used. For example,

[0348]

number

[0349] may be configured via higher layers for CE mode, and the WTRU may transmit the PUCCH repeatedly in the higher layer configured PUCCH resources over one or multiple subframes.

[0350] The higher layer configured PUCCH resources for CE mode shall be the same as the higher layer configured PUCCH resources for HARQ-ACK repetitions in normal mode.

[0351]

number

[0352] can be configured via higher layer signaling, and if the WTRU is configured with ackNackRepetition at higher layers in a normal mode of operation, when the WTRU receives (or has received) a PDSCH along with a corresponding PDCCH, the WTRU shall

[0353]

number

[0354] Use and send N ANrep -1 iterations, where N ANrep may be configured via higher layer signaling. If the WTRU is configured as and / or uses CE mode, the WTRU may not acknowledge the HARQ-ACK response even if the WTRU receives (or has received) a PDSCH along with a corresponding PDCCH.

[0355]

number

[0356] Use Send N' ANrepIt may or may not be repeated times.

[0357] N' ANrep is N ANrep N' can be configured via higher layer signaling independently of ANrep can have more than one candidate parameter. For example, N' ANrep = {n10, n20, n40, spare2}, which may suggest that 10, 20, and 40 repetitions may be used for HARQ-ARQ response transmission.

[0358] N' ANrep is N ANrep Same as N' ANrep =N ANrep may be also possible.

[0359] N' ANrep is N ANrep For example, N ANrep A multiple of N' ANrep In the example, N' ANrep =N ANrep ×N temp where N temp may be a predefined positive integer.

[0360] A single repetitionFactor may be configured via higher layers, and repetitionFactor is in PUCCH-ConfigCommon and may be interpreted differently depending on the mode of operation. ANrep = {n2,n4,n6,spare1} and N' ANrep = {n10,n20,n40,spare2} is used depending on the repetitionFactor. Thus, if the WTRU is configured with repetitionFactor=1, N ANrep = n2 and N' ANrep =n10 can be implicitly constructed.

[0361] N' ANrepN′ may be defined as a function of at least one of the number of repetitions for the corresponding (E)PDCCH transmission, the number of repetitions for the corresponding PDSCH transmission, and / or the CE-level used. ANrep may be defined as a function of the total aggregation level of the (E)PDCCH, where the total aggregation level may be defined as the multiplication of the aggregation level and the number of repetitions.

[0362] N' ANrep may be dynamically indicated via the corresponding (E)PDCCH. For example, the DCI format in the corresponding (E)PDCCH may include one or more explicit bits to indicate the number of repetitions to use (or that may be required and / or used) for the HARQ-ACK response in CE mode.

[0363] The higher layer configured PUCCH resource for the CE mode can be (implicitly) indicated, for example, using a predefined offset with the higher layer configured PUCCH resource for HARQ-ACK repetition in normal mode. For example, PUCCH resource

[0364]

number

[0365] can be configured via higher layer signaling for normal mode, and then

[0366]

number

[0367] can be used for the coverage extended mode. offset may be a predefined number. For example, Δ offset = 1 may be used. offset may be a configured value of a higher tier.

[0368] The HARQ-ACK repetitions in normal mode may be reused for CE mode by adding an additional number of repetitions. For example, the repetition factor in normal mode, e.g., N ANrep A reserved state of n = {n2, n4, n6, spare1}, e.g., spare1, may be used for the CE mode to indicate the number of repetitions required for the CE mode. For example, n32 may be substituted for spare1 to indicate that a HARQ-ACK response transmission (e.g., a PUCCH resource configured via higher layer signaling carrying a HARQ-ACK response transmission) requires or uses 32 repetitions, and N ANrep It can be shown that ={n2,n4,n6,n32} is used. ANrep may be updated when the mode of operation is changed from normal mode to coverage extended mode or vice versa.

[0369] A higher layer configured PUCCH resource may be used and may be defined as a function of subframe number. The PUCCH resource may be changed from subframe to another subframe.

[0370]

number

[0371] is n RNTI (e.g., C-RNTI), a subframe number, and / or a SFN number.

[0372]

number

[0373] may be used, where A and D are predefined positive integers,

[0374]

number

[0375] For example, A=39827 and D=2014 may be used, or D may be configured via higher layer signaling.

[0376] value

[0377]

number

[0378] may be used, where n is the slot number.

[0379] UL transmissions on the PUSCH may be granted via DCI formats such as DCI formats 0 and 4. DL transmissions for the PDSCH may be granted by several possible DCI formats including DCI formats 1, 1A, 1C, 2, 2A, 2B, 2C, and 2D. Such DCI may include fields for resource block allocation and resource allocation type, including, for example, support for contiguous or non-contiguous RB allocation, as well as support for different DL resource allocation types 0, 1, and 2, and UL resource allocation types 0 and 1.

[0380] In an embodiment, the DCI resource allocation field included in the DCI is used to distinguish between resource allocations for a WTRU operating in a CE mode and a WTRU operating in a non-CE mode (e.g., normal mode). For example, in, e.g., a first step, a WTRU receiving the DCI can determine whether it is operating in a CE mode or a non-CE mode. The WTRU can determine which mode it is operating in as a function of a previously received configuration, such as RRC, or it can use radio link measurements to decide which mode to apply, or it can derive the applicable mode from the received signaling in the DCI or through the MAC CE for the time period under consideration. Two or more coverage extension levels may or may need to be distinguished and / or used when operating in a CE mode. In another (e.g., next) step, the WTRU can interpret the DCI resource allocation feed according to the determined mode from the first step, and the WTRU can configure receiver operation to decode the allocated PDSCH or configure transmitter operation to send the allocated PUSCH, e.g., according to the interpreted DCI.

[0381] A WTRU that may operate or decide to operate in a non-CE mode may decode the DCI resource allocation field according to the coding of the existing LTE resource allocation type, but upon deciding to operate in a CE mode, the WTRU may decode the resource DCI allocation field according to a resource allocation type and / or coding scheme that may be valid for a WTRU operating in one or more CE modes and / or with one or more CE levels.

[0382] In an embodiment, the encoding and / or interpretation of DCI resource allocation for a WTRU operating in CE mode may include, or may be selected to include, one or more limitations on the number and / or maximum number of allocated RBs. For example, the maximum number of allocated RBs may not exceed a maximum of N RBs for a given CE level. For example, the maximum value of N may be 6 for all CE levels.

[0383] In another example, the number of allocated RBs may correspond (or correspond only to) a well-defined (or clearly determined) set of possible RBs, e.g., 1, 2 or 4 RBs or 2, 4, 6 RBs, etc. Each CE level may have a well-defined (or clearly determined) set, such as 1, 2 or 4 RBs for one CE level (e.g., CE level 2) and 2, 4, 6 RBs for another CE level (e.g., CE level 1).

[0384] In another example, the RB allocation may include (or only include) a selected subset of OFDM tones that are part of the allocated PRBs, e.g., PRBs in which only REs 1-6 and not REs 7-12 are used to carry the signal. In this example, one advantage is that a WTRU operating in CE mode may be assigned PDSCH or PUSCH transmission resources that can maximize the power spectral density, e.g., the receive or transmit power per RE, for the PDSCH reception or PUSCH transmission period under consideration. Similarly, restricting or selecting a well-defined set of allocatable RBs may enable the application of a channel coding rate that can maximize the coding gain for a typical small payload for MTC type applications given the parameterization of the LTE air interface in the time / frequency domain that may increase the link budget and communication range.

[0385] In another embodiment, a portion of the resource allocation bit field in a particular DCI format may be used in CE mode (or may be used only in CE mode). The particular DCI format may include DCI formats 0 and 4. For example, the NCE_RA bits of the NRA bits may be used in CE mode, where NRA is the number of bits for resource allocation in a particular DCI in normal mode, and NRA may be equal to or greater than NCE_RA. Consecutive NCE_RA bits may be selected in ascending or descending order.

[0386] In an example, the remaining NRA-NCE_RA bits may be reused for CE mode specific operations. For example, the remaining bits may be used to indicate a CE mode repetition level for a PUSCH or PDSCH transmission. In another example, the remaining bits may be used to indicate a CE mode and / or CE level frequency hopping pattern for a PUSCH or PDSCH transmission with repetition. In this case, frequency hopping may be used from a subframe to another subframe.

[0387] In another example, the remaining NRA-NCE_RA bits can be used as a virtual CRC, allowing a predefined bit sequence such as 0 or 1 to be used for all remaining bits.

[0388] In another embodiment, the number of resource blocks, the number of MCS levels, and / or the number of HARQ processes may be limited in CE mode. In an example, NCE_RA may be defined according to the CE level. A smaller NCE_RA may be used for higher CE levels, in which case a higher CE level may represent a smaller number of repetitions. The DCI payload size may be smaller for lower CE levels, e.g., due to smaller NCE_RA bits. The DCI payload size may be kept the same for all CE levels, and the unused bits may be used as a virtual CRC.

[0389] In another example, a subset of MCS levels may be used for CE mode, and the number of supported MCS levels may vary depending on the CE level. Fewer bits may be used for the MCS field for lower CE levels. For example, a 5-bit MCS field may be used for normal mode, whereas a 4-bit MCS field may be used for a CE mode with CE level 1. A 3-bit MCS field may be used for a CE mode with CE level 2. The DCI payload size may be smaller for lower CE levels, e.g., due to a smaller MCS field. The DCI payload size may be kept the same for all CE levels, and the unused bits may be used as a virtual CRC.

[0390] In another example, a subset of HARQ processes may be used for CE mode, and the number of supported HARQ processes may vary depending on the CE level. Fewer HARQ processes may be used for CE mode and lower CE levels. For example, eight HARQ processes may be used for normal mode, whereas fewer than eight HARQ processes may be used for CE mode. In an example, four HARQ processes may be supported in a CE mode with CE level 1, and two HARQ processes may be supported in a CE mode with CE level 2.

[0391] The resource allocation in the CE mode or for the CE level is determined based on a predetermined number N alloc In the example, N alloc PRBs (e.g., N=6) may be used, for example, at all times for CE mode or for a particular level of CE mode. If the system bandwidth is greater than six PRBs, the locations of the N PRBs may be predetermined, configured via higher signaling, or dynamically indicated from the DCI. In another example, N alloc can be determined as a function of the iteration level (or number of iterations).

[0392] For one or more UL power control parameters and / or values, the WTRU may at least one of receive (e.g., from an eNodeB), configure, be configured (e.g., by the eNodeB), determine, calculate, use, or intend to use separate values ​​for CE mode and non-CE mode (e.g., normal mode). The separate values ​​may be equal or unequal.

[0393] For one or more UL power control parameters and / or values, the WTRU may at least one of receive (e.g., from an eNodeB), configure, be configured (e.g., by the eNodeB), determine, calculate, use, or intend to use a separate value for each of one or more CE levels (e.g., iteration levels). The separate values ​​may be equal or unequal.

[0394] PUSCH (e.g., P PUSCH,c (i)) and / or PUCCH (e.g. P PUCCH The UL transmit power of (i) may be determined based on one or more UL power control parameters and values, where the UL power control parameters and values ​​are (i)P CMAX,c (i), (ii)Δ F_PUCCH (F), (iii)P O_PUCCH , and / or P O_NOMINAL_PUCCH and P O_UE_PUCCH (iv) at least one or more of the parameters thereof may include O_PUSCH,c (j), and / or P O_NOMINAL_PUSCH,c (j) and P O_UE_PUSCH,c At least one or more of the parameters may include (j), c (j), (vi)Δ TF,cThe UL power control parameter may include at least one of: (i), (vii) total transmit power for PUCCH and / or PUSCH and / or SRS, e.g., in subframe i; and / or (viii) any other UL power control related parameters.

[0395] For example, in CE mode, the UE may transmit P CMAX,c (i), P PUSCH,c (i), and / or P PUCCH The value of (i) may be set to a fixed value (or a value determined at the first subframe of a particular time window), and the particular time window may be located within a repetition window that may be associated with a CE level. The particular time window (e.g., may be or may be referred to as several consecutive subframes) may be a predefined number (or a number configured by the eNB), which may be less than or equal to the minimum number of repetitions in the CE mode for PUSCH transmission. Alternatively, the particular time window may be the same as the number of repetitions for a particular CE level at which the UE can operate.

[0396] As another example, in CE mode, the UE may c The value of (j), e.g., a path loss scalar, may be set (or configured to be set) to a fixed value such as 1. The UE may increase the UL power to reduce the path loss, e.g., PL C As another example, in CE mode, the UE may set α to a fixed value such as 0, which may configure the transmit power independently of the path loss. c The value of (j) may be set (or may be configured to be set).

[0397] As another example, in CE mode, the WTRU may set the value of the PUSCH and / or PUCCH total power to a maximum value, e.g., P CMAX,c(i). The WTRU may not need to receive closed loop power control commands, e.g., TPC commands, in this case, since the transmit power may be fixed at a particular value. However, TPC signaling may be used for other purposes that are not closed loop power control TPC.

[0398] As another example, in CE mode, the WTRU may be configured with N, e.g., 4, different values ​​of alpha, e.g., {1, 8, 6, 4}, each of which may be used by the WTRU for a correspondingly specific iteration, e.g., {1, 2, 4, 8}.

[0399] PUCCH transmission may be performed differently depending on the mode of operation (normal mode or CE mode) and / or the CE level. For example, a maximum transmit power may be used for PUCCH transmission when the WTRU is configured with or using a CE mode. In another example, the power control formula may be different for PUCCH transmission depending on the mode of operation and / or the CE level.

[0400] In normal mode, the PUCCH power may be determined according to a power control formula or equation, such as Equation 1. Formula and equation may be used interchangeably.

[0401] In CE mode, the scaled path loss may be used in the power control equation, e.g., as shown in Equation 5, where the path loss term PL C may be scaled by β, where β may have a value from 0 to 1. Alternatively, β may have a value of “0”, and no path loss is compensated.

[0402]

number

[0403] P O_PUCCH can be configured differently in normal mode and CE mode.O_PUCCH A value, for example one of two values, may be used depending on the mode of operation. O_PUCCH The value can be individually configured depending on the CE level.

[0404] Repeat compensation may be provided and / or used.

[0405] The impact of the repetition level on the UL transmit power in CE mode may be modeled by the addition of a new component to the power control and / or power headroom equation. This component may be modeled as a function of the repetition level. An example of this additional component in the UL power control equation may be dc(Rp), where Rp indicates the coverage extension repetition level (e.g., Rp=2 when 2 repetitions may be used) and dc(.) represents a function of Rp that may or may not be the same for all component carriers c. In this way, the PUSCH and / or PUCCH power control equation may become as follows:

[0406]

number

[0407]

number

[0408] An example of this additional component that may be used in the UL power control formula, e.g., dc(Rp), is α×10log 10 (b×Rp+c), where a, b, and c may be parameters with values ​​that may be fixed or determined by the implementation and / or may be configured dynamically and / or semi-statically by the eNodeB, for example by signaling. Examples of such parameters may be a=b=1 and c=0. This may result in having the following power control additional component:

[0409] dc (Rp)=10log 10 (Rp) The PUSCH and PUCCH power control equations may be as follows:

[0410]

number

[0411]

number

[0412] Using the above or similar equations for power control can result in the WTRU adjusting its UL transmit power for a given repetition level, for example, on a subframe-by-subframe basis (or at least on a subframe-by-subframe basis in which it may transmit).

[0413] The initial PUCCH and / or PUSCH transmit power may be set based on the power ramp-up of the PRACH transmission for which the WTRU may have received a random access response (RAR) from the eNodeB, e.g., the PRACH that may have been successfully received and / or decoded by the eNodeB. For example, an initial value of the TPC accumulation term fc(i) in the PUSCH power calculation may be set based on the PRACH power ramp-up value, which may be set equal to the total power ramp-up from the first to last preamble transmitted in the serving cell c, plus any adjustments based on TPC commands that may be included in the random access response from the eNodeB.

[0414] For example, the initial value of the accumulator is fc(0)=ΔP rampup,c +δ msg2,c It can be said that:

[0415] CE mode may be used to represent operation or intended operation in a manner that can (or may be intended to) extend coverage.

[0416] In one example, a WTRU that may use coverage extension (CE) or may be in a CE mode may transmit at a fixed power, such as its maximum power (e.g., the maximum power configured by the WTRU).

[0417] In another example, the transmit power may be determined by the WTRU based on factors that may include one or more of the path loss, the TPC commands, the received parameters, any one or more factors that may be included in the legacy power control equation, the number of iterations, etc. The WTRU may transmit at this power as long as it does not exceed its maximum allowed power, which may be the WTRU's configured maximum output power.

[0418] Power headroom (PH) and PH reporting for CE mode may be provided and / or used.

[0419] For example, the power headroom for the serving cell, PHc, is calculated by multiplying the calculated power of the WTRU by the configured maximum output power of the WTRU, e.g., P CMAX,c and Pcomputed_unconstrained,c, where this calculated power, e.g., Pcomputed_unconstrained,c, may be the calculated power that does not take into account (or prior to) constraints that may be imposed on the transmit power by the WTRU's maximum power or power allocation to higher priority channels.

[0420] The power headroom may be expressed by the following equation for a serving cell (or CC) c in subframe i: PHc(i)=Pcmax,c(i)-Pcomputed_unconstrained,c(i) Equation 6

[0421] For example, PH for LTE (or LTE-A) for a subframe with PUSCH without PUCCH transmission is 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 7 It can be given by:

[0422] For a WTRU that may use or require coverage extension, the path loss (PL) that may be measured or determined by the WTRU may be higher than what may be a typical PL for a non-CE mode WTRU, which may include cell edge WTRUs. This may result in a calculated power that is higher and a PH that is more negative than may be expected for the range of reported values ​​in the PH Report (PHR).

[0423] As an example, a legacy WTRU may report a power headroom value using a particular number of bits (e.g., 6) that can correspond to a particular number of possible values ​​(e.g., 64) that can represent a particular range of PH values ​​(e.g., [-23:40] dB) with particular steps (e.g., 1 dB) between values. A WTRU that may experience a higher PL may need to report a value outside of that range.

[0424] For CE mode, there may be at least one different mapping of PH (e.g., from a legacy mapping) to PH values ​​for reporting, for PH reporting when operating in a CE manner (e.g., when employing repetition for coverage extension), or for another reason or condition. For example, there may be one new mapping for CE mode. In another example, one CE (or repetition) level may have a different mapping from another CE (or repetition) level. There may be different mappings for each CE (or repetition level).

[0425] In CE mode, for PH reporting when operating in a coverage extension manner (e.g., when employing repetition for coverage extension), or for another reason or condition, the WTRU may use one or more of a different number of bits, a different number of available values, a different range, and / or a different step size when mapping a calculated or otherwise determined PH value to a PH value for reporting. The mapping that the WTRU uses may depend on whether the WTRU is in CE mode or is otherwise operating (or intended to operate) in a coverage extended manner and / or a CE level or repetition level that the WTRU uses (or intends to use) or can use (or intends to use).

[0426] As an example, a WTRU not operating in CE mode may use a non-CE mode or legacy mapping, e.g., [-23:40] dB with 1 dB steps. A WTRU that may be operating in CE mode may use a different mapping, such as [-40:23] dB with a 1 dB step size or [-80:47] dB with a 2 dB step size. In another example, a WTRU that may be operating in CE mode with one CE level, e.g., CE level 1, may use a mapping such as [-28:35] dB with a 1 dB step size, and a WTRU that may be operating in CE mode with another CE level, e.g., CE level 2, may use a mapping such as [-33,30] with a 1 dB step size.

[0427] The WTRU may change between CE and non-CE modes and / or between CE (or repetition) levels. The WTRU may use a PHR mapping that may correspond to that mode or CE (or repetition) level when it determines and / or transmits a PHR.

[0428] The WTRU's calculated transmit power may include a compensation factor for the iterations that the WTRU may be performing in the UL. Such iterations may provide gains across multiple subframes that may allow the WTRU to reduce its power in each subframe. As previously described herein, a compensation factor, e.g., dc(Rp), may be included in the calculation.

[0429] If the calculated power for transmission includes a compensation factor, then the PH calculation in its use of the calculated power may also include the compensation factor. This may provide the eNodeB with a more accurate representation of the WTRU's headroom in the subframe. Alternatively, the compensation factor may be removed from the calculated power for the PH calculation. This may provide the eNodeB with a more accurate representation of the PL the WTRU may be experiencing in the subframe. If the compensation factor may be determined by the eNodeB, it does not matter which approach may be taken as long as the WTRU and the eNodeB have the same understanding.

[0430] If the calculated power for transmission does not include a compensation factor, then the PH calculation in that use of the calculated power may not include a compensation factor either, or a compensation factor may be included in the calculated power for (e.g., only for) the PH calculation.

[0431] In the event that the WTRU does not calculate the transmit power for a transmission, as may be the case, for example, with a fixed transmit power (e.g., using its maximum transmit power), it may (e.g., still be) useful for the WTRU to calculate (or otherwise determine) the PH and report it, for example, to the eNodeB.

[0432] PH can be calculated in the normal manner, or one or more coefficients included in the legacy PH calculation can be removed, set to zero, or set to a fixed value.

[0433] For example, for transmission at a fixed power, TPC commands may not be used and, as a result, the TPC accumulation coefficient may be removed or set to zero.

[0434] Since the eNodeB may be aware of (or be able to calculate) the values ​​of some of the elements in a normal or legacy PH calculation, e.g., Type 1 PH shown in Equation 7, it may be useful to send a modified or virtual PH report that may use or be based on a reference grant or format.

[0435] For example, the WTRU may use a reference grant (eg, 1RB) instead of an actual grant for a subframe, which may be equivalent to removing a term that may be based on the grant (eg, MPUSCH,c(i)).

[0436] In another example, the WTRU may remove all terms other than the PL term (or the PL term and the repetitive compensation term) and may calculate PH based on that term (or those terms). The WTRU may apply a multiplier (e.g., α c ) may be included or excluded. For example, the WTRU may transmit a PHR, which may correspond to a PH value, which may be calculated as follows:

[0437] PHc(i) = Pcmax,c(i) - 10log10(PL)

[0438] or

[0439] PHc(i) = Pcmax,c(i) - 10log10(α c ×PL)

[0440] The PHR may include values ​​representing PHc and / or Pcmax,c.

[0441] The PHR may or may not include an indication as to whether the P-MPR may be affecting the reported Pcmax,c value. The P-MPR may be a power management reduction that the WTRU may take to meet certain requirements, such as, for example, specific absorption rate (SAR) requirements, when the WTRU may be in close proximity to a human body and / or when the WTRU may transmit over multiple radio access technologies (RATs).

[0442] For example, regardless of whether the PH value may be useful to the eNodeB when the WTRU transmits at a fixed power, such as maximum power, the value of Pcmax,c may be useful to the eNodeB, for example, to know the power at which the WTRU may be transmitting.

[0443] For example, a WTRU that may require or use coverage extension may have its maximum power influenced by the P-MPR, e.g., based on human proximity, and the WTRU's maximum transmit power (or configured maximum output power) may vary.

[0444] In one embodiment, the WTRU may send a PHR, which may include Pcmax,c for serving cell c, for example, without any PHc value.

[0445] Certain triggers (eg, legacy triggers), such as PL and / or Scell ​​activation triggers, may not be used by a CE mode WTRU. P-MPR triggers may or may not be used by a CE mode WTRU.

[0446] In another embodiment, a new mechanism, e.g., a new MAC Control Element (MAC-CE) or RRC signaling, may be used to send Pcmax,c by the WTRU to the eNodeB. An indication as to whether the P-MPR may have affected the reported Pcmax,c value may be included in the new signaling. One or more PHR triggers (e.g., legacy PHR triggers) may be used to trigger this signaling.

[0447] Link adaptation for the DL control channel may be provided and / or used. In an embodiment, the WTRU-specific search space for the (E)PDCCH may depend on the mode of operation (eg, normal mode or CE mode) and / or the CE level.

[0448] In (or for) normal mode, a WTRU-specific search space may be configured in all downlink subframes, whereas in (or for) CE mode, a WTRU-specific search space may be configured in a subset DL subframes. When the WTRU is configured in normal mode, the WTRU may monitor the (E)PDCCH in all downlink subframes and / or when the WTRU is configured in CE mode, the WTRU may monitor the (E)PDCCH in a subset of DL subframes.

[0449] The subset of subframes for the (E)PDCCH in CE mode may differ depending on the CE level. The subset of subframes for each CE level may be partially overlapped. The WTRU may monitor the (E)PDCCH in different sets of subframes based on the CE level used.

[0450] The subset of subframes for (E)PDCCH monitoring may be defined as a function of the number of (E)PDCCH repetitions for the CE level.

[0451] (E) The subset of subframes for PDCCH monitoring may be predefined depending on the CE level.

[0452] (E) The subset of subframes for PDCCH monitoring may be configured via higher layer signaling.

[0453] The WTRU-specific search space may be defined with the number of iterations for the CE mode. For example, a table for the WTRU-specific search space may be defined as a combination of the aggregation level and the number of iterations. An example is provided in Table 4.

[0454] For the PDCCH, the WTRU may monitor an aggregation level set, such as {1,2,4,8}, with the number of repetitions being predefined or configurable by higher layer signaling. For a particular aggregation level, more than one repetition may be used.

[0455] In the EPDCCH distributed mode, the WTRU may monitor an aggregation level set, such as {1, 2, 4, 8, 16}, combining the number of iterations, which may be predefined or configured by higher layer signaling.

[0456] For a particular aggregation level with multiple repetition levels, (E)PDCCH resources may be partially overlapped. For example, if there may be two candidates with aggregation level 4, one using 4 repetitions and the other using 8 repetitions, the first 4 repetitions may be overlapped for the two candidates. If the WTRU receives an (E)PDCCH with an (E)PDCCH candidate with 4 repetitions, the WTRU may skip decoding the (E)PDCCH candidate with 8 repetitions.

[0457] The number of iterations may vary depending on the aggregation level, for example as shown in Table 4.

[0458] [Table 4]

[0459] In another embodiment, the set of aggregation levels in the WTRU-specific search space may depend on the mode of operation (eg, normal mode or CE mode) and / or the CE level, eg, as shown in Table 5.

[0460] A subset of aggregation levels may be used depending on the CE level, for example, an aggregation level set with a set of repetitions {1,2} may be used for CE level 1, and an aggregation level set with a set of repetitions {4,8} may be used for CE level 2, where the set of repetitions may be predefined or configured by higher layer signaling.

[0461] The sets of aggregation levels may overlap for each CE level, for example, CE level 2 may use aggregation level set {4,8}, and CE level 3 may use aggregation level set {8,16}.

[0462] EPDCCH localized transmission may be supported in a particular mode of operation or at a particular CE level. For example, EPDCCH localized transmission may be supported in (or only in) normal mode and / or CE level 1 (e.g., the lowest CE level that can use a minimum number of repetitions).

[0463] [Table 5]

[0464] In another embodiment, a particular aggregation level may be used in CE mode, and the number of repetitions may be determined as a function of the CE level. The aggregation level may be a maximum number of (E)CCEs within a particular number of PRBs (e.g., PRBs that may be used for CE mode, or a maximum number of allocated PRBs for (E)PDCCH in CE mode) in a particular subframe, a configured number of higher layers, or a predefined number. For example, (E)PDCCH candidates that may be monitored may be defined based on the number of repetitions for each CE level with a particular number of aggregation levels (e.g., 16). An example is provided in Table 6.

[0465] [Table 6]

[0466] In another embodiment, the repetition number of the (E)PDCCH can be indicated in the DCI (e.g., received DCI), e.g., to avoid ambiguity between (E)PDCCH candidates with the same aggregation level with different repetition numbers. Alternatively, a different C-RNTI can be used for each repetition number. For example, C-RNTI-1 can be used for a first repetition number in a particular CE level (e.g., R=2 at CE level 1 and R=8 at CE level 2 in the example of Table 6), and C-RNTI-2 can be used for a second repetition number in the same CE level. The received, indicated, or detected repetition number for or by or for use with (E)PDCCH (or for or used by) can be used to determine the starting subframe of the associated PDSCH and / or PUSCH.

[0467] In another embodiment, the WTRU (eg, a WTRU receiver implementation) may monitor the (E)PDCCH depending on the mode of operation (eg, normal mode or CE mode) and / or the CE level.

[0468] The WTRU may start decoding a lower aggregation level and number of repetitions, where a lower aggregation level may be a smaller L and a lower number of repetitions may be a smaller R. If the WTRU successfully receives the (E)PDCCH, the WTRU may skip decoding the (e.g., additional or different) (E)PDCCH.

[0469] When a WTRU monitors an (E)PDCCH with repetitions R in CE mode, the WTRU may aggregate a received signal that may include decoded soft bits, modulation symbols, and / or OFDM symbols. The WTRU will not attempt to decode the aggregated signal until the number of repetitions is completed.

[0470] When the WTRU monitors the (E)PDCCH with repetition R in CE mode, the WTRU may synthesize the received signal and may keep attempting to decode and check the CRC at each repetition.

[0471] (E) Link adaptation of the PDCCH common search space may be provided and / or used.

[0472] In an embodiment, the (E)PDCCH common search space may be defined or configured separately for normal mode operation and CE mode operation, where the separation may be based on different resources, such as (i) different time / frequency resources, (ii) different sets of (E)CCEs, and / or (iii) different sets of (E)REGs. The resources for normal mode and CE mode may be mutually exclusive or may partially overlap.

[0473] The WTRU may monitor separate (E)CCEs that may be reserved for CE mode operation. For example, the first 16 CCEs in each subframe (e.g., (E)CCE#0 through (E)CCE#15) may be used for the (E)PDCCH common search space in normal mode operation, and (E)CCEs that are not overlapped with the (E)CCEs used for normal mode may be defined or configured for the CE mode-specific common search space.

[0474] The (E)CCEs for the CE mode-specific common search space may be located at (E)CCE #16 to (E)CCE #23. A WTRU operating in CE mode may monitor the (E)PDCCH in the CE mode-specific common search space.

[0475] The WTRU may monitor a subset of (E)PDCCHs (or DCIs) in a CE mode-specific common search space and other (E)PDCCHs (or DCIs) in a normal mode common search space. For example, an (E)PDCCH having a P-RNTI and a RA-RNTI may be monitored in a CE mode-specific common search space, while other (E)PDCCHs may be monitored in a normal mode common search space.

[0476] In another embodiment, a subset of RNTIs may be supported in the (E)PDCCH common search space for CE mode operation. For example, the WTRU may monitor DCI that may be scrambled by one or more of RA-RNTI, SI-RNTI, P-RNTI, and eIMTA-RNTI in the normal mode common search space, whereas the WTRU may monitor (e.g., monitor only) RA-RNTI and P-RNTI in the CE mode common search space. (E)PDCCH common search space and common search space may be used interchangeably.

[0477] In the normal mode common search space, an aggregation level, for example, {4,8}, may be used with iterations, whereas in the CE mode specific common search space, a single aggregation level (for example, the maximum aggregation level) may be used.

[0478] In another embodiment, the (E)PDCCH common search space may be defined separately for each CE level. For example, the common search space for CE level 1 and CE level 2 may be at different time and / or frequency locations, or at the same time and / or frequency locations with different sets of (E)CCEs. The WTRU may monitor a particular DCI in the corresponding common search space based on the determined or configured CE level. In another example, the common search space for a lower CE level may be a subset of the common search space for a higher CE level, where the lower CE level may have a smaller number of iterations. The common search space for different CE levels may have a different number of aggregation levels and / or iterations.

[0479] The (E)PDCCH candidates in the CE mode specific common search space are determined by the aggregation level (N AL ) and iteration level (N R ) can be defined as a combination of a specific total aggregation level (N TAL =N AL *N ROne or more (E)PDCCH candidates for the RA-RNTI may be defined in a CE mode-specific common search space. The (E)PDCCH candidates in the CE mode-specific common search space may have a single aggregation level and multiple repetition levels. The (E)PDCCH candidates in the CE mode-specific common search space may have multiple aggregation levels with a single repetition level. The repetition level and / or aggregation level may be determined as a function of at least one of the RNTI and the DCI format. In an example, an (E)PDCCH carrying a DCI scrambled by an RA-RNTI may be monitored with a repetition level N1 (e.g., 20), and an (E)PDCCH carrying a DCI scrambled by a P-RNTI may be monitored with a repetition level N2 (e.g., 30). In another example, an (E)PDCCH carrying DCI format A (e.g., DCI format 1A) may be monitored at a repetition level N1 (e.g., 20), and an (E)PDCCH carrying DCI format B (e.g., DCI format 1C) may be monitored at a repetition level N2 (e.g., 30).

[0480] The CE mode specific common search space may be located in a subset of subframes. In an example, the CE mode specific common search space may be located in a subset of N consecutive subframes. CSS A WTRU in a CE mode operation may monitor the CE mode specific common search space (e.g., only) in a subset of subframes that may be defined as a common search space burst. CSS Within this subframe, (E)PDCCH candidates may be transmitted repeatedly.

[0481] In another embodiment, a subset of the (E)CCEs used for the normal mode (E)PDCCH common search space may be used for the CE mode-specific (E)PDCCH common search space.

[0482] The first eight (E)CCEs (e.g., (E)CCE#0 to (E)CCE#7) may be used for the CE mode-specific common search space. Alternatively, the first four (E)CCEs may be used for the CE mode-specific common search space. A single aggregation level may be used. For example, an aggregation level of 8 may be used in the CE mode-specific common search space. A repetition window may be defined, and the (E)PDCCH, which may be transmitted in the CE mode-specific common search space, may be transmitted repeatedly within the repetition window. The aggregation level may be changed depending on the repetition window. For example, a non-overlapping repetition window may be defined for the CE mode-specific common search space, and the aggregation level may be changed depending on the repetition window.

[0483] The CE mode-specific common search space may be located in a subset of subframes. A subset of (E)CCEs used for CE mode may be reserved in (e.g., only in) a subset of subframes. A WTRU operating in CE mode may monitor the common search space in a subset of subframes if the subframe includes a CE mode-specific common search space. The subset of subframes that include the CE mode-specific common search space may be configured via higher layer signaling. The subset of subframes that include the CE mode-specific common search space may be defined as a function of at least one of a subframe number, a SFN number, a physical cell ID, and / or a WTRU-ID.

[0484] In another embodiment, an RNTI-specific repetition window may be defined and / or used. For example, multiple repetition windows that do not overlap in the time domain may be defined and / or used, and a specific RNTI-based (E)PDCCH may be transmitted for each repetition window. The (E)PDCCH carrying DCI scrambled by the RA-RNTI may be transmitted in a specific repetition window, and the (E)PDCCH carrying DCI scrambled by the P-RNTI may be transmitted in another repetition window that does not overlap with the repetition window for the (E)PDCCH carrying DCI scrambled by the RA-RNTI. The (E)PDCCH received in a specific repetition window may be determined (e.g., implicitly) as a specific RNTI based on the time position of the repetition window. The repetition window for the RA-RNTI may be placed several frames after the last subframe of the coverage extended PRACH resource. Resource configuration information for the RNTI-specific repetition window may be transmitted on a broadcast channel (e.g., SIB).

[0485] Link adaptation of the broadcast channel may be provided and / or used. Two types (or at least two types) of PBCHs may be transmitted in a cell, such as a legacy PBCH and a CE PBCH. A legacy PBCH may be a PBCH transmitted in subframe 0 in all radio frames and is not repeated in a radio frame. A CE PBCH may be a PBCH transmitted in a subframe other than subframe 0 and may be repeated in a radio frame. A CE PBCH may be transmitted in subframe 0 in an OFDM symbol that does not contain a legacy PBCH. A WTRU may receive the legacy PBCH and / or the CE PBCH to obtain master information block (MIB) information. In some embodiments, for example, if the CE PBCH is a repetition of the legacy PBCH in a radio frame, the legacy PBCH may be considered as one of the repetitions of the CE PBCH. A CEr PBCH may be used to represent a CE PBCH transmission that does not include a legacy PBCH transmission.

[0486] In an embodiment, a WTRU or WTRU receiver (e.g., a WTRU receiver for PBCH reception) may attempt to decode the legacy PBCH, and if that fails, may attempt to decode the CEr PBCH and / or combine one or more repetitions of the legacy PBCH and / or the CEr PBCH in order to successfully decode the PBCH and obtain the MIB.

[0487] The WTRU may attempt to decode the legacy PBCH (e.g., initially). If the WTRU fails to receive and / or decode the legacy PBCH within a particular PBCH cycle (where a particular PBCH cycle may be a 40 ms window during which the MIB information is not (or may not be) changed), the WTRU may continue to attempt to receive and / or decode the legacy PBCH.

[0488] One or more events may trigger the WTRU to decode (or attempt to decode) the CEr PBCH. Receiving and / or decoding the CEr PBCH may include combining multiple repetitions of the CEr PBCH with each other and / or with the legacy PBCH. For example, if the WTRU fails to decode the legacy PBCH K times, the WTRU may start receiving and / or decoding the CEr PBCH. The number K may be a fixed number in the WTRU implementation. Alternatively, the number K may be a different number depending on the RSRP measurement level. A timer may be used to receive the MIB over the legacy PBCH, and if the WTRU cannot successfully decode the PBCH before the timer expires, the WTRU may start receiving and / or decoding the CEr PBCH when or after the timer expires.

[0489] The WTRU may check whether the CEl PBCH is supported in the cell, and may use the CEl PBCH if supported.

[0490] The WTRU may perform a cell search procedure, and once the cell search procedure is completed, the WTRU may start receiving the PBCH. If the WTRU consumes (or has consumed) more time than a certain (e.g., predefined) threshold to complete the cell search procedure (e.g., receive a synchronization channel), the WTRU may start receiving and / or decoding the CEr PBCH. The WTRU may otherwise start receiving and / or decoding the legacy PBCH. The threshold may be set as the time requirement for synchronization channel reception in normal mode. If the WTRU consumes (or has consumed) more time than a predefined threshold to complete the cell search procedure, the WTRU may first check whether the CEr PBCH is supported in the cell. For the CEr PBCH probing, the WTRU may use a correlator to allow correlation of the legacy PBCH signal and repetitions of the legacy PBCH at other time positions in the radio frame. If the autocorrelation of these two signals is higher than a predefined level, the WTRU may assume that the CEr PBCH is supported in the cell. The WTRU may then perform the PBCH reception procedure over the CEl PBCH.

[0491] The SIBs may be transmitted in specific subframes. For example, SIB1 may be transmitted in subframe #5 in every radio frame, and the associated (E)PDCCH, which may carry scheduling information, may be CRC scrambled by the SI-RNTI in the subframe. Resource allocation and MCS level may be dynamically selected in each subframe for SIB1 transmission.

[0492] A coverage enhanced SIB (CE-SIB) may carry system information for CE mode operation and / or for a WTRU that may be operating in CE mode.

[0493] In an embodiment, an associated (E)PDCCH for a CE-SIB may be transmitted over multiple subframes. For example, the associated (E)PDCCH may be transmitted repeatedly over multiple subframes within a time window. The WTRU may (e.g., initially) receive the associated (E)PDCCH for the CE-SIB within the time window and (e.g., then) receive the CE-SIB based on the information carried via the associated (E)PDCCH. The associated (E)PDCCH for the CE-SIB may be transmitted with a specific RNTI for the CE-SIB.

[0494] In another embodiment, the CE-SIB may be transmitted at a specific time / frequency (e.g., time and / or frequency) location and / or at a specific MCS level. The WTRU may receive the CE-SIB without an associated (E)PDCCH. The specific time / frequency location may be predefined. The specific time / frequency location may be determined as a function of a cell ID. The specific time / frequency location may be indicated via a MIB. In an example, the WTRU may receive an indication from an eNB (e.g., an indication that may be signaled in a MIB) that may provide scheduling information for the CE-SIB. The scheduling information may include one or more of a time and frequency location, a schedule (e.g., periodicity, offset, etc.), and / or an MCS level of the CE-SIB. If the information does not include the MCS level, the WTRU may, or may need to attempt to, decode a CE-SIB with a set of MCS levels that may be used for the CE-SIB transmission, e.g., to determine the MCS level that may be used. The MCS level may be determined as a function of the TBS size of the CE-SIB, and the modulation order may be fixed (e.g., QPSK). In another example, the MCS level for a particular time / frequency location and / or CE-SIB may be predefined as a set. The WTRU may need to attempt to decode the CE-SIB within the set of time / frequency locations and / or MCS levels until it receives the CE-SIB.

[0495] In an embodiment, the CE-SIB may be transmitted in a subset of radio frames. The radio frames that include the CE-SIB may be defined as a function of the physical cell ID (PCI). The radio frames that include the CE-SIB may be determined from a modulo operation that may be used with the SFN and the PCI. For example, the CE-SIB may be placed in a radio frame where the SFN mod PCI=0. The radio frames that may include the CE-SIB may be determined from a list of radio frames that may include the CE-SIB (e.g., the SFN of the radio frame).

[0496] The radio frame that includes the CE-SIB may depend on the location of the CE-PBCH. For example, a timing relationship between the CE-SIB and the CE-PBCH may be defined and / or known. The radio frame that includes the CE-SIB may be located in the n+k radio frame, where the last radio frame that includes the CE-PBCH is n, and k may be a positive integer.

[0497] The frequency resources allocated to the CE-SIB in a subframe that includes (or may include) the CE-SIB may be predefined in the subframe that includes (or may include) the CE-SIB. For example, the central x PRBs may be used for CE-SIB transmission in the subframe that includes the CE-SIB, where x may be a positive integer. Alternatively, the frequency resources may be defined as a function of the system bandwidth and / or the subframe number.

[0498] It is contemplated that the CE level, extended coverage level, repetition number, repetition window length, and CE amount may be used interchangeably. Furthermore, it is contemplated that the channel, physical channel, and LTE (or LTE-A) physical channel may be used interchangeably. The LTE (or LTE-A) physical channel may be at least one of a PDSCH, a PUSCH, a PUCCH, an (E)PDCCH, a PRACH, and / or a PBCH.

[0499] In some embodiments, more than one CE level may be defined and / or configured for a channel. The number of CE levels may depend on the physical channel and / or traffic type. Alternatively, the number of CE levels may be defined and / or configured independently for each physical channel or group of physical channels.

[0500] The number of CE levels supported (or may be used) for the PRACH may be different from the number of CE levels supported (or may be used) for one or more data channels, such as the PDSCH and / or PUSCH. For example, three CE levels may be used for the PRACH, whereas six CE levels may be used for the PDSCH and / or PUSCH. The CE level for the PRACH may be defined as the number of repetitions for the PRACH preamble transmission. The number of repetitions for each CE level may be predefined, broadcast, configured in a higher layer, and / or determined as a function of the number of repetitions of the PBCH. The CE level of the data channel (e.g., the PDSCH and / or the PUSCH) may be defined as the number of repetitions, where the number of repetitions may be determined by a higher layer signaling or broadcast channel (e.g., SIB) or by a dynamic indicator from the DCI format, and the CRC of the DCI may be scrambled by the RNTI used (or may be used) for the data channel (e.g., the C-RNTI) or the RNTI used (or may be used) for the CE level indicator.

[0501] The same number of CE levels may be used for the group of channels, and a determined CE level among the supported CE levels may be applied to the channels of the group. CEA CE level of may be defined for a group of channels including PRACH and (E)PDCCH, where a CE level is determined for PRACH and the same CE level may be used for (E)PDCCH for corresponding RAR reception. If a CE level is determined for PRACH, the CE level may be used for (E)PDCCH. In some embodiments, a number of repetitions may be used as the CE level for a channel, and the number of repetitions for a channel for a particular CE level may differ from the number of repetitions used for a CE level for another channel in the group. For example, CE level 1 for PRACH may use 10 repetitions, whereas CE level 1 for (E)PDCCH may use 15 repetitions. In other embodiments, a power boost level may be used as the CE level for a channel, and the power boost level for a channel at a particular CE level may differ from the power boost level for another channel in the group at the same CE level. In an example, a 3 dB boost may be considered as a CE level 1 for the (E)PDCCH, a 4 dB boost may be considered as a CE level for the PDSCH, and a power boost level may be defined as a power ratio between a reference signal and a PDSCH RE.

[0502] Different numbers of CE levels may be used depending on the type of information or traffic that may be carried on the physical channel. For example, a PDSCH containing unicast traffic may have N CE levels. CE CE level can be used, whereas PDSCH containing broadcast information is CE The following CE levels may be used:

[0503] The CE level may be dynamically indicated in the associated DCI for the (E)PDCCH, PDSCH, and / or PUSCH. CE can be used for PDSCH including unicast traffic, and log2[N CEA 1-bit CE level indicator field may be defined in the associated DCI scrambled by the C-RNTI. CE may be used for the PDSCH containing broadcast information, and log2[M CE A 1-bit CE level indicator field may be defined in the associated DCI scrambled by the SI-RNTI. The number of bits of the CE level indicator field in the DCI may be defined as a function of the RNTI type. The number of CE levels indicated in the DCI may be determined depending on the RNTI type. The number of bits of the CE level indicator field may be defined as a function of the DCI format. The number of repetitions used for the CE level may be determined as a function of the RNTI type, DCI format and / or information type that may be included in the PDSCH, as predefined, e.g., signaled by higher layer signaling.

[0504] The CE level may be dynamically indicated in the associated DCI for the PDSCH and / or PUSCH, such as a DCI whose CRC may be scrambled by a C-RNTI. The CE level of a DCI whose CRC is scrambled by an RNTI other than the C-RNTI may be determined based on the CE level used for the PRACH. The CE level for the PDSCH, paging, and / or PMCH, including the SIB, may be determined as a function of the CE level that may be determined in the RACH procedure. The CE level for the PDSCH, including unicast traffic, may be the same as the CE level that may be determined during the RACH procedure, for example, unless otherwise configured by a higher layer or indicated by the DCI format.

[0505] In some embodiments, the CE level may be indicated (e.g., implicitly) by the associated (E)PDCCH CE level used and / or detected from blind decoding. For example, a WTRU in CE mode may monitor the (E)PDCCH at multiple CE levels, and if it receives an (E)PDCCH at a particular CE level, the WTRU may assume that the same CE may be used for the associated PDSCH or PUSCH.

[0506] In another embodiment, the same number of CE levels may be defined for all physical channels. However, the number of iterations for the CE levels may be determined as a function of the channel and / or the traffic type carried on the channel. As an example, CE CE levels can be defined for the PRACH, where CE level 1 is N rep repetitions, and CE level 1 for PDSCH is M rep It can accommodate N iterations, where rep and M. rep In another example, N CE CE levels can be defined or configured for the PDSCH, where CE level 1 is N if the PDSCH contains broadcast information. rep If the PDSCH can support M repetitions and the PDSCH contains unicast traffic, CE level 1 is rep The number of CE levels may be predefined (or signaled) and the corresponding number of repetitions may be configured by higher layer signaling per channel.

[0507] In some embodiments, a window-based transmission may be used. In such embodiments, a time window may be defined for the physical channel, and the physical channel may be transmitted repeatedly within the time window. In one example, a time window may be defined for the (E)PDCCH, PDSCH, and PUSCH, among other options, and the WTRU may receive the (E)PDCCH within the (E)PDCCH window with repetition. The associated PDSCH or PUSCH may be transmitted or received in the following PDSCH or PUSCH window.

[0508] The windows for the physical channels may overlap partially or completely, regardless of the direction of communication (e.g., DL or UL). For example, the WTRU may monitor the (E)PDCCH in the (E)PDCCH window, while the WTRU may transmit the PUSCH in the PUSCH window, which may overlap completely or partially with the (E)PDCCH window. The WTRU may transmit and receive simultaneously in a subframe.

[0509] The windows of the physical channels may only overlap partially or completely in the same direction of communication (e.g. DL or UL). The (E)PDCCH window may overlap partially or completely with the PDSCH window. The (E)PDCCH window may not overlap with the PUSCH window.

[0510] In another embodiment, an offset from the last subframe of the (E)PDCCH may be used to indicate the starting subframe of at least one of the PDSCH, PUSCH, and / or PUCCH windows as shown by way of example in FIG. 8. For example, if the (E)PDCCH window ends at subframe n, then the starting subframe of the PDSCH window is subframe n+N. DL and the starting subframe of the PUSCH window is subframe n+N UL where N DL and N UL can be an offset.

[0511] Number NDL and N UL N may be a predefined number that applies to all WTRUs. DL and N UL may be configured via higher layer signaling in a cell-specific or WTRU-specific manner. For example, UL may depend on the length of the PDSCH window. UL may be determined as a function of the length of the PDSCH window, for example when the PDSCH window length is N PDSCH If so, N UL is N PDSCH +1, i.e. N UL =N PDSCH It can be +1. N DL and N UL may be indicated in the associated DCI. For example, N DL may be indicated in the associated DCI for the PDSCH, and N UL may be indicated in the associated DCI for the PUSCH. DL and N UL may be indicated in the associated DCI for the PDSCH and / or PUSCH if the WTRU is configured in CE mode.

[0512] N DL and N UL The relationship between N and N may depend on the WTRU capabilities. For example, if the WTRU has full-duplex mode capabilities, then N DL =1 and N UL = 4 may be used, whereas if the WTRU has half-duplex and / or time-duplex mode capabilities, N DL =1 and N UL =N OFF may be used.

[0513] In some embodiments, the PUSCH and PUCCH windows may overlap partially or completely. If the WTRU receives a PDSCH allocation and a PUSCH grant in the same (E)PDCCH window, the WTRU may transmit both PUSCH and PUCCH in the PDSCH region. Thus, the HARQ_ACK may be piggybacked on the data. Alternatively, if the WTRU receives a PDSCH allocation and a PUSCH grant in the same (E)PDCCH window, the WTRU may discard one of the channels in the uplink.

[0514] In an embodiment, a method performed in a wireless transmit / receive unit (WTRU) includes determining a number of repetitions for an uplink signal, deriving an uplink transmit power for the uplink signal, the transmit power being based on the number of repetitions, and transmitting the uplink signal with repetitions using the determined number of repetitions and the derived uplink transmit power.

[0515] In such an embodiment, a determination of the number of repetitions for an uplink signal used for a physical random access channel (PRACH) is based on downlink measurements. The determination of the number of repetitions may be made by selecting a number of repetitions from a set of repetition levels. The set of repetition levels may be configured by an enhanced Node-B (eNB). The determination of the number of repetitions may be made by selecting a number of repetitions from the set of repetition levels.

[0516] The determination of the number of repetitions may be made based on information received from an enhanced Node-B (eNB). The uplink signal may be sent on a physical uplink shared data channel (PUSCH). The determination of the number of repetitions may be made based on information received in a downlink control indicator (DCI). The derivation of the uplink transmit power may be made using a power control equation that includes an offset parameter, the offset parameter being determined as a function of the number of repetitions. Deriving the uplink transmit power may include determining a target received power and deriving the uplink transmit power from the target received power.

[0517] The target received power may be determined based on information received from an enhanced Node-B (eNB). The target received power may be determined as a function of the number of iterations.

[0518] An uplink signal with repetition may be an uplink signal that is repeatedly transmitted over multiple subframes.

[0519] In an embodiment, a method performed in a wireless transmit / receive unit (WTRU) includes receiving a downlink control information (DCI) message from a radio access network, and setting a repetition level for at least one shared channel between the WTRU and the radio access network based at least in part on the downlink control information message.

[0520] In such an embodiment, a transmit power of the WTRU may be set, the transmit power depending at least in part on the repetition level. The downlink control information message may include a transmit power control (TPC) command, the repetition level being based at least in part on the transmit power control command. The repetition level may be set for a physical downlink control channel (PDCCH) based on the transmit power control (TPC) command. The repetition level may be set for a physical uplink control channel (PUCCH) based on the transmit power control (TPC) command. The shared channel is a physical downlink shared channel (PDSCH). The WTRU may be configured to receive data on the physical downlink shared channel (PDSCH) using the repetition level.

[0521] A power offset can be set between the cell-specific reference signal (CRS) and the physical downlink shared channel (PDSCH), where the power offset is determined at least in part by a repetition level of the physical downlink shared channel (PDSCH).

[0522] The shared channel may be a Physical Uplink Shared Channel (PUSCH). The method may further include transmitting data on the Physical Uplink Shared Channel using the repetition level.

[0523] In an embodiment, a wireless transmit / receive unit (WTRU) includes a transceiver operative to receive a transmit power control (TPC) command from a radio access network, and decoder logic operative to set a repetition level for at least one shared channel between the WTRU and the radio access network in response to the transmit power control (TPC) command, where the repetition level is based at least in part on the transmit power control (TPC) command.

[0524] In such an embodiment, the shared channel may be a physical downlink shared channel (PDSCH), and the decoder logic may be further operative to receive data on the physical downlink shared channel (PDSCH) using the repetition level. The shared channel may be a physical uplink shared channel (PUSCH), and the transceiver may be operative to transmit data on the physical uplink shared channel using the repetition level.

[0525] In an embodiment, a method performed in a wireless transmit / receive unit (WTRU) includes the steps of receiving a transmission from a radio access network, the transmission including a plurality of subframes, each subframe including a plurality of control channel elements (CCEs); determining whether the WTRU is in a coverage extension mode; and if the WTRU is not in the coverage extension mode, monitoring a first set of CCEs for physical downlink control channel (PDCCH) communications, the first set of CCEs being a first search space; and if the WTRU is in the coverage extension mode, monitoring a second set of CCEs for physical downlink control channel (PDCCH) communications, the second set of CCEs being a second search space, the search space being different from the first search space.

[0526] In such an embodiment, the physical downlink control channel may be an enhanced physical downlink control channel (EPDCCH). The first search space may be monitored at multiple aggregation levels and the second search space may be monitored at a single aggregation level. The second search space may be monitored at a single aggregation level and multiple repetition levels. The second search space may be monitored at multiple aggregation levels and a single repetition level.

[0527] In an embodiment, a wireless transmit / receive unit (WTRU) includes a transceiver operative to receive a transmission from a radio access network comprising a plurality of subframes, each subframe comprising a plurality of control channel elements (CCEs). In this embodiment, the transceiver is operative to monitor a first set of CCEs for physical downlink control channel (PDCCH) communications when the WTRU is not in a coverage extension mode, the first set of CCEs being a first search space, and the transceiver is operative to monitor a second set of CCEs for physical downlink control channel (PDCCH) communications when the WTRU is in a coverage extension mode, the second set of CCEs being a second search space, the search space being different from the first search space.

[0528] In such an embodiment, the physical downlink control channel may be an enhanced physical downlink control channel (EPDCCH). The first search space may be monitored at multiple aggregation levels and the second search space may be monitored at a single aggregation level. The second search space may be monitored at a single aggregation level and multiple repetition levels. The second search space may be monitored at multiple aggregation levels and a single repetition level.

[0529] In an embodiment, a method performed in a wireless transmit / receive unit (WTRU) includes selecting a first coverage extension level for a first communication channel from a first number of coverage extension levels, selecting a second coverage extension level for a second communication channel from a second number of coverage extension levels, communicating with a radio access network over the first communication channel using the first coverage extension level, and communicating with the radio access network over the second communication channel using the second coverage extension level.

[0530] In such an embodiment, the first number of coverage extension levels may be different from the second number of coverage extension levels. Communicating using the first coverage extension level may include communicating using a first number of iterations determined by the first coverage extension level, and communicating using the second coverage extension level may include communicating using a second number of iterations determined by the second coverage extension level. The number of iterations associated with the first coverage extension level is determined by signaling from the radio access network.

[0531] The step of communicating using the first coverage extension level may include the step of communicating using a first power boost level determined by the first coverage extension level, and the step of communicating using the second coverage extension level may include the step of communicating using a second power boost level determined by the second coverage extension level.

[0532] The first communication channel may be a Physical Random Access Channel (PRACH) and the second communication channel may be a shared channel. The shared channel may be a Physical Downlink Shared Channel (PDSCH). The shared channel may be a Physical Uplink Shared Channel (PUSCH).

[0533] Communicating over the PRACH can include transmitting a PRACH preamble having a number of repetitions determined by a first coverage extension level, where a second number of coverage extension levels can be determined at least in part based on a type of traffic carried on the second communication channel.

[0534] The second communication channel may be a physical downlink shared channel (PDSCH), and the second number of coverage extension levels may be determined based at least in part on whether the PDSCH carries unicast or broadcast traffic.

[0535] In an embodiment, a wireless transmit / receive unit (WTRU) includes a transceiver operative to perform a set of functions, the set of functions including: selecting a first coverage extension level for a first communication channel from a first number of coverage extension levels; selecting a second coverage extension level for a second communication channel from a second number of coverage extension levels; communicating with a radio access network over the first communication channel using the first coverage extension level; and communicating with a radio access network over the second communication channel using the second coverage extension level.

[0536] In such an embodiment, the first number of coverage extension levels may be different from the second number of coverage extension levels.

[0537] The capability of communicating using the first coverage extension level may include capability of communicating using a first number of iterations determined by the first coverage extension level, and the capability of communicating using the second coverage extension level may include capability of communicating using a second number of iterations determined by the second coverage extension level.

[0538] The number of iterations associated with the first coverage extension level may be determined by signaling from the radio access network.

[0539] The capability of communicating using the first coverage extension level may include a capability of communicating using a first power boost level determined by the first coverage extension level, and the capability of communicating using the second coverage extension level may include a capability of communicating using a second power boost level determined by the second coverage extension level.

[0540] The first communication channel may be a Physical Random Access Channel (PRACH) and the second communication channel may be a shared channel. The shared channel may be a Physical Downlink Shared Channel (PDSCH). The shared channel may be a Physical Uplink Shared Channel (PUSCH). Communicating via the PRACH may include transmitting a PRACH preamble having a number of repetitions determined by the first coverage extension level.

[0541] The second number of coverage extension levels may be determined based at least in part on a type of traffic carried on a second communication channel. The second communication channel may be a physical downlink shared channel (PDSCH), and the second number of coverage extension levels may be determined at least in part on whether the PDSCH carries unicast or broadcast traffic.

[0542] In an embodiment, a method performed in a wireless transmit / receive unit (WTRU) includes the steps of determining whether the WTRU is in a coverage extension mode, receiving a first downlink physical channel with repetition from a radio access network within a first downlink time window after determining that the WTRU is in a coverage extension mode, and transmitting a first uplink physical channel with repetition to the radio access network within a first uplink time window.

[0543] In such an embodiment, the first downlink physical channel may be a Physical Downlink Control Channel ((E)PDCCH). The first downlink physical channel may be a Physical Downlink Shared Channel (PDSCH). The first uplink physical channel may be a Physical Uplink Shared Channel (PUSCH). The first uplink physical channel may be a Physical Uplink Control Channel (PUCCH).

[0544] The first downlink time window may at least partially overlap with the first uplink time window.

[0545] There may be at least one subframe in which at least a portion of the receiving step and at least a portion of the transmitting step both occur.

[0546] The method may further include receiving, with repetition, a second downlink physical channel from the radio access network within a second downlink time window, the second downlink time window may at least partially overlap with the first downlink time window.

[0547] The first downlink physical channel may be a Physical Downlink Control Channel ((E)PDCCH) and the second downlink physical channel may be a Physical Downlink Shared Channel (PDSCH).

[0548] The method may further include sending the second uplink physical channel with repetitions to the radio access network within a second uplink time window.

[0549] The second uplink time window may at least partially overlap with the first uplink time window.

[0550] The first uplink physical channel may be a Physical Uplink Control Channel (PUCCH), and the second uplink physical channel may be a Physical Uplink Shared Channel (PUSCH).

[0551] In an exemplary method, the first downlink physical channel can be a physical downlink control channel ((E)PDCCH) having a terminal subframe and the first uplink physical channel can be a physical uplink shared channel (PUSCH). In such an embodiment, the method can further include receiving with repetitions the physical downlink shared channel from the radio access network within a second downlink time window, the second downlink time window starting from a downlink offset after the terminal subframe and the first uplink time window starting from an uplink offset after the terminal subframe.

[0552] In an embodiment, a wireless transmit / receive unit (WTRU) includes a transceiver operative to perform a set of functions, the set of functions including: determining whether the WTRU is in a coverage extension mode; receiving a first downlink physical channel with repetition from a radio access network within a first downlink time window after determining that the WTRU is in a coverage extension mode; and transmitting a first uplink physical channel with repetition to the radio access network within a first uplink time window.

[0553] In such an embodiment, the first downlink physical channel may be a Physical Downlink Control Channel ((E)PDCCH). The first downlink physical channel may be a Physical Downlink Shared Channel (PDSCH). The first uplink physical channel may be a Physical Uplink Shared Channel (PUSCH). The first uplink physical channel may be a Physical Uplink Control Channel (PUCCH).

[0554] The first downlink time window may at least partially overlap with the first uplink time window. There may be at least one subframe in which at least a portion of the receiving and at least a portion of the transmitting both occur.

[0555] The transceiver may be further operative to receive, with repetition, a second downlink physical channel from the radio access network within a second downlink time window. The second downlink time window may at least partially overlap with the first downlink time window. The first downlink physical channel may be a Physical Downlink Control Channel ((E)PDCCH), and the second downlink physical channel may be a Physical Downlink Shared Channel (PDSCH).

[0556] The transceiver may be further operative to send the second uplink physical channel with repetition to the radio access network within a second uplink time window. The second uplink time window may at least partially overlap with the first uplink time window. The first uplink physical channel may be a Physical Uplink Control Channel (PUCCH), and the second uplink physical channel may be a Physical Uplink Shared Channel (PUSCH).

[0557] In an embodiment, a method performed in a wireless transmit / receive unit (WTRU) includes the steps of determining whether the WTRU is in a coverage extension mode; receiving a first downlink physical channel with repetition from a radio access network within a first downlink time window after determining that the WTRU is in the coverage extension mode; determining a second downlink time window and a first uplink time window based at least in part on the first downlink physical channel; receiving the second downlink physical channel with repetition from the radio access network within the second downlink time window; and transmitting the first uplink physical channel with repetition to the radio access network within the first uplink time window.

[0558] In such an embodiment, the first downlink physical channel may be an (E)PDCCH, the second downlink physical channel may be a PDSCH, and the first uplink physical channel may be a PUSCH. Determining the second downlink time window and the first uplink time window may include defining the second downlink time window as starting at a downlink offset with respect to the first downlink time window, and defining the second uplink time window as starting at an uplink offset with respect to the first downlink time window.

[0559] The downlink offset and the uplink offset may be predefined. The downlink offset and the uplink offset may be configured by higher layer signaling. The uplink offset may depend on the length of the second downlink time window. At least one of the downlink offset and the uplink offset may be configured by a downlink control information (DCI) message. The downlink offset and the uplink offset may depend at least in part on whether the WTRU supports full-duplex communication.

[0560] In an embodiment, a wireless transmit / receive unit (WTRU) includes a transceiver operative to perform a set of functions, the set of functions including: receiving a first downlink physical channel from a radio access network within a first downlink time window with repetition; determining a second downlink time window and a first uplink time window based at least in part on the first downlink physical channel; receiving the second downlink physical channel from the radio access network within the second downlink time window with repetition; and transmitting the first uplink physical channel to the radio access network within the first uplink time window with repetition.

[0561] The first downlink physical channel may be an (E)PDCCH, the second downlink physical channel may be a PDSCH, and the first uplink physical channel may be a PUSCH. The function of determining the second downlink time window and the first uplink time window may include a function of defining the second downlink time window as starting at a downlink offset with respect to the first downlink time window, and a function of defining the second uplink time window as starting at an uplink offset with respect to the first downlink time window.

[0562] The downlink offset and the uplink offset may be predefined. The downlink offset and the uplink offset may be configured by higher layer signaling. The uplink offset may depend on the length of the second downlink time window. At least one of the downlink offset and the uplink offset may be configured by a downlink control information (DCI) message. The downlink offset and the uplink offset may depend at least in part on whether the WTRU supports full-duplex communication.

[0563] Although the features and elements are described above in certain combinations, one skilled in the art will understand that each feature or element may be used alone or in any combination with other features and elements. In addition, 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 over 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). Software and associated processors may be used to implement a radio frequency transceiver for use in a WTRU, a WTRU, a terminal, a base station, an RNC, or any host computer. [Industrial Applicability]

[0564] The present invention can be generally applied to wireless communication systems. [Explanation of symbols]

[0565] 102a~102d WTRU 103, 104, 105 RAN 106, 109 Core Network 107, 108 PSTN 110 Internet 112 Other Networks 114a, 114b base station 118 processors 120 Transceiver (transmitter / receiver) 122 Antenna

Claims

1. A method implemented in a network node, comprising: receiving a physical random access channel preamble on a first uplink resource; transmitting a random access response, the random access response including a scheduling grant, the scheduling grant including a first bit field and a second bit field, the first bit field indicating a second uplink resource, the second bit field indicating a modulation and coding scheme index or at least a portion of the second bit field indicating a number of repetitions; receiving a physical uplink shared channel transmission, the physical uplink shared channel transmission is received on the second uplink resource a number of times corresponding to the number of repetitions; the physical uplink shared channel transmission is received on the second uplink resource without repetition based on the second bit field indicating the modulation and coding scheme index; A method for providing the above.

2. The at least a portion of the second bit field indicating a number of repetitions comprises: a physical random access channel preamble from a set of one or more physical random access channel preambles designated for coverage extension; and the first uplink resource from a set of one or more uplink resources designated for coverage extension; 2. The method of claim 1 , further comprising: said at least a portion of said second bit field indicating said number of iterations based on at least one of:

3. 3. The method of claim 1, wherein the at least a portion of the second bit field includes a first portion of a plurality of portions of the second bit field, and a second portion of the plurality of portions of the second bit field indicates a modulation and coding scheme index.

4. 3. The method of claim 1 or 2, further comprising the step of transmitting configuration information indicating one or more candidate numbers of repetitions, the number of repetitions indicated by the at least a portion of the second bit field being an indication of one of the one or more candidate numbers of repetitions.

5. The method of claim 1 or 2, wherein the random access response is a physical downlink shared channel transmission associated with a physical downlink control channel transmission having a cyclic redundancy check scrambled by a random access radio network temporary identifier.

6. The method of claim 1 or 2, wherein the random access response includes a power offset for uplink transmission on at least one of the second uplink resources.

7. The method of claim 1 or 2, wherein the random access response includes a power offset for a Physical Uplink Shared Channel (PUSCH) transmit power.

8. The method of claim 1 or 2, wherein the random access response includes a timing correction for an uplink transmission on at least one of the second uplink resources.

9. transmitting an indication of a mode of operation that is a Coverage Extension (CE) mode of operation. The method of claim 1 or 2, further comprising:

10. A network node comprising a transmitter, a receiver, a processor and a circuit including a memory, The circuit comprises: receiving a physical random access channel preamble on a first uplink resource; transmitting a random access response including a scheduling grant, the scheduling grant including a first bit field and a second bit field, the first bit field indicating a second uplink resource, the second bit field indicating a modulation and coding scheme index or at least a portion of the second bit field indicating a number of repetitions; Receive a physical uplink shared channel transmission; the physical uplink shared channel transmission is received on the second uplink resource a number of times corresponding to the number of repetitions; The physical uplink shared channel transmission is received on the second uplink resource without repetition based on the second bit field indicating the modulation and coding scheme index. A network node configured as follows:

11. The at least a portion of the second bit field indicating a number of repetitions comprises: a physical random access channel preamble from a set of one or more physical random access channel preambles designated for coverage extension; and the first uplink resource from a set of one or more uplink resources designated for coverage extension; 11. The network node of claim 10, further comprising: said at least a portion of said second bit field indicating said number of iterations based on at least one of:

12. 12. The network node of claim 10 or 11, wherein the at least a portion of the second bit field includes a first portion of a plurality of portions of the second bit field, and a second portion of the plurality of portions of the second bit field indicates a modulation and coding scheme index.

13. 12. The network node of claim 10 or 11, wherein the circuitry is configured to transmit configuration information indicating one or more possible numbers of iterations, and the number of iterations indicated by the at least a portion of the second bit field is an indication of one of the one or more possible numbers of iterations.

14. 12. A network node according to claim 10 or 11, wherein the random access response is a physical downlink shared channel transmission associated with a physical downlink control channel transmission having a cyclic redundancy check scrambled by a random access radio network temporary identifier.

15. 12. The network node of claim 10 or 11, wherein the random access response includes a power offset for uplink transmissions on at least one of the second uplink resources.

16. 12. The network node of claim 10 or 11, wherein the random access response includes a power offset for a Physical Uplink Shared Channel (PUSCH) transmit power.

17. 12. The network node of claim 10 or 11, wherein the random access response includes a timing correction for an uplink transmission on at least one of the second uplink resources.

18. 12. A network node according to claim 10 or 11, further configured to transmit an indication of a mode of operation being a Coverage Extension (CE) mode of operation.

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