BR112017024977B1 - FREE CHANNEL EVALUATION PROCEDURE ON MASTER AND SLAVE DEVICES - Google Patents

Abstract

FREE CHANNEL EVALUATION PROCEDURE IN MASTER AND SLAVE DEVICES. To provide a generic access rule, the present disclosure proposes a new potential set of adaptation rules for LBE based on LBT. The generic access rule of the present disclosure provides LTE-U and Wi-Fi coexistence and DL/UL coexistence on both LTE-U and Wi-Fi. The equipment receives, from the first master device, an allocation of resources for communication with the second master device. The equipment also determines a type of CCA procedure to perform before communicating with the second master device on an unlicensed channel. The equipment further performs a CCA procedure to obtain a transmission opportunity based on the determination, the CCA procedure being one of an ICCA procedure or an ECCA procedure. Furthermore, the equipment transmits data to the second master device according to the resource allocation on the unlicensed channel when the transmission opportunity is obtained.

Description

References to related deposit requests

[001] This application claims the benefit of U.S. Provisional Application Serial No. 62/165,861, entitled “CCA PROCEDURE AT MASTER AND SLAVE DEVICES”, filed on May 22, 2015 and U.S. Patent Application Serial No. 15/153,516 , entitled “CLEAR CHANNEL ASSESSMENT PROCEDURE AT MASTER AND SLAVE DEVICES” and deposited on May 12, 2016, which are expressly incorporated herein in full, by way of reference.

BACKGROUND Field

[002] The present disclosure relates generally to communication systems and more particularly, to the use of an unlicensed radio frequency spectrum band for at least a portion of dispute-based communications over a wireless communication system.

Background

[003] Wireless communication systems are widely used to provide various telecommunications services, such as telephony, video, data, messages and broadcasts. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, frequency division multiple access systems (OFDMA), single carrier frequency division multiple access systems (SC-FDMA), and time division synchronous code division multiple access systems (TD-SCDMA).

[004] These various multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that allows different wireless devices to communicate on a municipal, national, regional and even global level. An exemplary telecommunications standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP). LTE is designed to support mobile broadband access through improved spectral efficiency, cost reduction, and improved services using OFDMA in DL, SC-FDMA in UL, and multiple-input multiple-output (MIMO) antenna technology. However, as demand for mobile broadband access continues to increase, there is a need for further improvements in LTE technology. These improvements may also be applicable to other multi-access technologies and telecommunications standards that use these technologies.

[005] Some communication modes may allow communication between a base station and a UE over a contention-based shared radio frequency spectrum band, or over different radio frequency spectrum bands (e.g., a radio frequency spectrum band). radio frequency spectrum band or an unlicensed radio frequency spectrum band) of a cellular network. With the increase in data traffic on cellular networks that use a licensed radio frequency spectrum band, offloading at least some data traffic to an unlicensed radio frequency spectrum band may provide a cellular operator with opportunities to improved data transmission capacity. An unlicensed radio frequency spectrum may also provide service in areas where access to a licensed radio frequency spectrum band is unavailable.

[006] Before gaining access to, and communicating over, a contention-based shared radio frequency spectrum band, a base station or UE may perform a Listen Before Talk (LBT) procedure to attempt access to the base station's band. shared radio frequency spectrum. An LBT procedure may include performing a clear channel assessment (CCA) procedure to determine whether a channel in the contention-based shared radio frequency spectrum band is available. When it is determined that the channel of the contention-based shared radio frequency spectrum band is available, a channel reservation signal such as a channel usage beacon signal (CUBS) may be transmitted to reserve the channel.

[007] There is an unmet need to coordinate an LBT procedure between base stations and UEs, where one base station helps coordinate the process for another (type of) BS. For example, there is a need for a licensed BS to support the unlicensed BS, or an unlicensed BS to support other unlicensed BS.

SUMMARY

[008] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not a broad overview of all aspects covered, and is not intended to identify key or critical elements of all aspects, nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented below.

[009] Before gaining access to and communicating over a contention-based radio frequency spectrum band, a base station or UE may perform a Listen Before Talking (LBT) procedure to attempt access to the frequency spectrum band shared radio. An LBT procedure may include performing a clear channel assessment (CCA) procedure to determine whether a channel in the contention-based shared radio frequency spectrum band is available. When it is determined that the channel of the contention-based shared radio frequency spectrum band is available, a channel reservation signal such as a channel usage beacon signal (CUBS) may be transmitted to reserve the channel.

[0010] There is an unmet need to coordinate an LBT procedure between base stations and UEs, where one base station helps coordinate the process for another (type of) BS. For example, there is a need for a licensed BS to support the unlicensed BS, or an unlicensed BS to support other unlicensed BS.

[0011] To coordinate an LBT procedure between base stations and UE, the present disclosure proposes a new potential set of adaptation rules for Load Based Equipment (LBE) based on Listen Before Talking (LBT). The LBT procedure of the present disclosure provides LTE-unlicensed (LTE-U) and Wi-Fi coexistence and DL/UL coexistence on both LTE-U and Wi-Fi.

[0012] In one aspect of the disclosure, a method, a computer readable medium and an apparatus are provided. The device receives, from the first master device, an allocation of resources for communication with the second master device. The device also determines a type of CCA procedure to perform before communicating with the second master device on an unlicensed channel. The apparatus further performs a CCA procedure to obtain a transmission opportunity based on the determination, the CCA procedure being one of an initial CCA procedure (ICCA) or an extended CCA procedure (ECCA). Furthermore, the device transmits data to the second master device according to the resource allocation on the unlicensed channel when the transmission opportunity is obtained.

[0013] In a further aspect, the apparatus transmits a resource allocation to a slave device to communicate with the second master device. The device transmits resource allocation information to the second master device on a backhaul link. The apparatus further indicates a CCA type and CCA parameters to the slave device by at least one of providing configuration information in a communication before transmitting the resource allocation, establishing an indicator on the resource allocation, transmitting the resource allocation. resources on a channel type, or broadcasting resource allocation on a selected channel.

[0014] In another aspect, the apparatus receives, from the second master device, resource allocation information for the first master device on a backhaul channel link, the resource allocation being transmitted on a licensed channel and the resource allocation information, including an indication to reserve the unlicensed channel. The device also receives data according to resource allocation on an unlicensed channel from the slave device. The apparatus further performs, on the first master device, an ICCA procedure or an ECCA procedure to obtain a transmission opportunity on the unlicensed channel before receiving the data. The device also occupies, through the first master device, the unlicensed channel in the transmission opportunity.

[0015] To achieve the above and related purposes, the one or more aspects comprise the following characteristics fully described and particularly highlighted in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. These aspects are indicative, however, of only some of the various ways in which the principles of various embodiments may be employed and the embodiments described are intended to include all of these aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a diagram illustrating an example of a wireless communication system and access network.

[0017] FIGS. 2A, 2B, 2C and 2D are diagrams illustrating examples of LTE of a DL frame structure, DL channels within the DL frame structure, a UL frame structure, and UL channels within the UL frame structure, respectively.

[0018] FIG. 3 is a diagram illustrating an example of an Evolved Node B (eNB) and user equipment (UE) in an access network.

[0019] FIG. 4, shows a diagram illustrating an example of a wireless communication using an unlicensed spectrum, in accordance with aspects of the present disclosure.

[0020] FIG. 5 is an illustration of an example of a CCA procedure performed by a transmitting apparatus when seeking access to a contention-based shared radio frequency spectrum band, in accordance with various aspects of the present disclosure.

[0021] FIG. 6 is an illustration of an example of an extended CCA (ECCA) procedure performed by a transmitting apparatus when seeking access to a contention-based shared radio frequency spectrum band, in accordance with various aspects of the present disclosure.

[0022] FIG. 7 is a diagram illustrating communication between master devices and slave devices.

[0023] FIG. 8 is a diagram illustrating an ECCA procedure.

[0024] FIG. 9 is a diagram illustrating channel access procedures of a master device and a slave device on an unlicensed channel.

[0025] FIG. 10 is a diagram illustrating master devices and a slave device communicating in accordance with a CoMP procedure.

[0026] FIG. 11 is another diagram illustrating master devices and a slave device communicating in accordance with a CoMP procedure.

[0027] FIG. 12 is a flowchart of a wireless communication method.

[0028] FIG. 13 is a conceptual data flowchart illustrating the flow of data between different media/components in an exemplary apparatus.

[0029] FIG. 14 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0030] FIG. 15 is a flowchart of a wireless communication method.

[0031] FIG. 16 is a conceptual data flowchart illustrating the flow of data between different media/components in an exemplary apparatus.

[0032] FIG. 17 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0033] FIG. 18 is a flowchart of a wireless communication method.

[0034] FIG. 19 is a conceptual data flowchart illustrating the flow of data between different media/components in an exemplary apparatus.

[0035] FIG. 20 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

[0036] The detailed description presented below in connection with the attached drawings is intended to be a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a complete understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0037] Various aspects of telecommunications systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the detailed description below and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and design limitations imposed on the overall system.

[0038] By way of example, an element, or any portion of an element, or any combination of the elements can be implemented as a “processing system”, which includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, closed logic, discrete hardware circuits, and other suitable hardware configured to perform the various features described throughout this disclosure. One or more processors in the processing system may execute the software. Software should be interpreted broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, execution chains, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0039] Consequently, in one or more exemplary embodiments, the described functions can be implemented in hardware, software or any combination thereof. If implemented in software, functions may be stored in or encoded as one or more instructions or code in a computer-readable medium. Computer-readable medium includes computer storage medium. The storage medium can be any available medium that can be accessed by a computer. By way of example, and not as a limitation, such computer-readable media may comprise a random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, on magnetic disk, other magnetic storage devices, combinations of the above types of computer-readable media, or any other medium that can be used to store program code in the form of instructions or data structures that can be accessed by a computer .

[0040] FIG. 1 is a diagram illustrating an example of a wireless communication system and an access network 100. The wireless communication system (also known as a wireless wide area network (WWAN)) includes base stations 102, UEs 104 and an Evolved Package Core (EPC) 160. The base stations 102 may include macro cells (high-power cellular base station) and/or small cells (low-power cellular base station). Macro cells include eNBs. Small cells include femto cells, pico cells and micro cells.

[0041] The base stations 102 (collectively referred to as the Evolved Universal Mobile Telecommunications System (E-UTRAN) Terrestrial Radio Access Network (UMTS)) interface with the EPC 160 via backhaul channel links 132 ( e.g. SI interface). In addition to the other functions, the base stations 102 may perform one or more of the following functions: user data transfer, radio channel encryption and decoding, integrity protection, header compression, mobility control functions (e.g., handover , dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, non-access stratum (NAS) message distribution, NAS node selection, synchronization, radio access network (RAN) sharing ), multicast broadcast multimedia service (MBMS), subscriber and equipment registration, RAN information management (RIM), paging, positioning, and warning message delivery. Base stations 102 may communicate directly or indirectly (e.g., via EPC 160) with each other via backhaul links 134 (e.g., X2 interface). The backhaul links 134 may be wired or wireless.

[0042] The base stations 102 may communicate remotely with the UEs 104. Each of the base stations 102 may provide communications coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the cell small 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cells and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Domestic Evolved B Nodes (eNBs) (HeNBs), which can provide service to a restricted group known as a closed subscriber group (CSG). Communication links 120 between base stations 102 and UE 104 may include UL transmissions (also referred to as reverse link) from a UE 104 to a base station 102 and/or DL transmissions (also referred to as forward links) from a base station 102 to a UE 104. Communication links 120 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmission diversity. Communication links can be through one or more carriers. The base stations 102/UEs 104 may use spectrum bandwidth of up to Y MHz (e.g., 5, 10, 15, 20 MHz) per carrier allocated in a carrier aggregation of up to a total of Y x MHz (x carriers component) used for transmission in each direction. The carriers may or may not be adjacent to each other. Carrier allocation may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL than to UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell).

[0043] The wireless communications system may further include a Wi-Fi access point (AP) 150 communicating with Wi-Fi stations (STAs) 152 via communication links 154 in an unlicensed 5 GHz frequency spectrum When communicating in an unlicensed frequency spectrum, STAs 152/AP 150 may perform a clear channel assessment (CCA) before communicating to determine whether the channel is available.

[0044] The small cell 102' can operate in a licensed and/or unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ LTE and use the same unlicensed 5 GHz frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing LTE in an unlicensed frequency spectrum, can increase coverage and/or increase the capacity of the access network. LTE in an unlicensed spectrum may be referred to as LTE-unlicensed (LTE-U), and may employ techniques associated with Licensed Assisted Access (LAA) or MuLTEfire.

[0045] The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Server Gateway 166, a Multicast Broadcast Multimedia Service (MBMS) Gateway 168, a Multicast Broadcast Service Center (BM) -SC) 170, and a Packet Data Network (PDN) gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides carrier and connection management. All user Internet Protocol (IP) packets are transferred through the Server Gateway 166, which in turn is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and BM-SC 170 were connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and /or other IP services. The BM-SC 170 can provide MBMS user service provisioning and delivery functions. The BM-SC 170 can serve as an entry point for content provider MBMS transmission, can be used to authorize and initiate MBMS Bearer Services within a public mobile network (PLMN), and can be used to schedule MBMS transmissions. MBMS port 168 may be used to distribute MBMS traffic to base stations 102 belonging to an area of the Multicast Single Frequency Broadcast Network (MBSFN) that transmits a particular service, and may be responsible for session management (start /stop) and to collect billing information related to eMBMS.

[0046] The base station may also be referred to as a Node B, an Evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a set service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station 102 provides an access point for the EPC 160 to a UE 104. Examples of UEs 104 include a cell phone, a smartphone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant ( PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g. MP3 player), a camera, a game console, a tablet, a device smart device, a device worn on the body or any other device that functions similarly. The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, an apparatus, a user agent, a mobile client, a client, or some other appropriate terminology.

[0047] Referring again to FIG. 1, in certain aspects, the UE 104/eNB 102 may be configured for contention-based communications using unlicensed spectrum (198).

[0048] FIG. 2A is a diagram 200 illustrating an example of a DL frame structure in LTE. FIG. 2B is a diagram 230 illustrating an example of channels within the DL frame structure in LTE. FIG. 2C is a diagram 250 illustrating an example of a UL frame structure in LTE. FIG. 2D is a diagram 280 illustrating an example of channels within the UL frame structure in LTE. Other wireless communication technologies may have a different frame structure and/or different channels. In LTE, a frame (10 ms) can be divided into 10 equally sized subframes. Each subframe can include two consecutive time partitions. A resource grid can be used to represent the two time partitions, each time partition including one or more time-concurrent resource blocks (RBs) (also called physical RBs (PRBs)). The resource grid is divided into several resource elements (REs). In LTE, for a normal cyclic prefix, an RF contains 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols (for DL, OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB contains 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0049] As illustrated in FIG. 2A, some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation in the UE. DL-RS may include cell-specific reference signals (CRS) (also sometimes called common RS), UE-specific reference signals (UE-RS), and channel state information reference signals (CSI-RS). . FIG. 2A illustrates CRS for antenna ports 0, 1, 2, and 3 (denoted as R0, R1, R2, and R3, respectively), UE-RS for antenna port 5 (denoted as R5), and CSI-RS for antenna port antenna 15 (indicated as R). FIG. 2B illustrates an example of multiple channels within a DL subframe of a frame. The physical control format indicator channel (PCFICH) is within symbol 0 of partition 0 and has a control format indicator (CFI) that indicates whether the physical downlink control channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustrates a PDCCH that occupies 3 symbols). The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A UE can be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCH can have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subset including one RB pair). The physical ARQ (HARQ) hybrid autoretry request indicator channel (PHICH) is also within symbol 0 of partition 0 and carries the HARQ indicator (HI) which indicates the return of HARQ (ACK)/negative ACK ( NACK) based on physical uplink shared channel (PUSCH). The primary synchronization channel (PSCH) is within symbol 6 of partition 0 within subframes 0 and 5 of a frame and carries a primary synchronization signal (PSS) that is used by a UE to determine subframe timing and an identity of the physical layer. The secondary synchronization channel (SSCH) is within symbol 5 of partition 0 within subframes 0 and 5 of a frame and carries a secondary synchronization signal (SSS) that is used by a UE to determine an identity group number of physical layer cell. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical transmission channel (PBCH) is within symbols 0, 1, 2, 3 of partition 1 dp subframe 0 of a frame and carries a master information block (MIB). The MIB provides a series of RBs in DL system bandwidth, a PHICH configuration, and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, transmission system information not transmitted through the PBCH, such as system information blocks (SIB) and paging messages.

[0050] As illustrated in FIG. 2C, some of the REs carry demodulation reference signals ((DM-RS) for channel estimation in the eNB. The UE may in addition transmit sound reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure and a UE can transmit SRS in one of the combs. The SRS are used by an eNB for channel quality estimation to enable frequency dependent scheduling in the UL. within a UL subframe of a frame. A physical random access channel (PRACH) can be within one or more subframes within a frame based on the PRACH configuration. The PRACH can include six consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial access to the system and achieve UL synchronization. A physical uplink control channel (PUCCH) can be located at the bandwidth edges of the UL system. , such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a classification indicator (RI), and HARQ ACK/NACK feedback. PUSCH carries data and in addition can be used to load a Buffer Status Report (BSR), Power Level Report (PHR), and/or UCI.

[0051] FIG. 3 is a block diagram of an eNB 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a media access control (MAC) layer. Controller/processor 375 provides RRC layer functionality associated with transmitting system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and releasing RRC connection technology), inter-radio access technology (RAT) mobility and measurement configuration for UE measurement reports; PDCP layer functionality associated with header compression/decompression, security (encryption, decryption, integrity protection, integrity checking) and handover support functions; RLC layer functionality associated with transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC service PDUs RLC data and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs into transport blocks (TBs), demuliplexing MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority management and logical channel prioritization.

[0052] The transmit processor (TX) 316 and the receive processor (RX) 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical layer (PHY), may include error detection on transport channels, forward error correction (FEC) encoding/decoding of transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels and processing of MIMO antennas. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M phase shift keying ( M-PSK), M quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols are then split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., the pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel that carries a time-domain OFDM symbol stream. The OFDM stream is spatially pre-coded to produce multiple spatial streams. Channel estimates from a channel estimator 374 can be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each 318TX transmitter can modulate an RF carrier with a respective spatial flow for transmission.

[0053] In UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers modulated information over an RF carrier and provides the information to the receive processor (RX) 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover the spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The 356 RX processor then converts the OFDM symbol stream from the time domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the signal constellation points most likely transmitted by the eNB 310. These soft decisions may be based on channel estimates calculated by the channel estimator 358. The decisions soft signals are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the eNB 310 on the physical channel. The data and control signals are then provided to the controller/processor 359 which implements layer 3 and layer 2 functionality.

[0054] Controller/processor 359 may be associated with a memory 360 that stores program codes and data. Memory 360 may be referred to as a computer-readable medium. In UL, controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from UE 160. Controller/processor 359 is also responsible by detecting errors using an ACK and/or NACK protocol to support HARQ operations.

[0055] Similar to the functionality described in connection with DL transmission by eNB 310, controller/processor 359 provides RRC layer functionality associated with system information acquisition (e.g., MIB, SIBs), RRC connections, and measurement reports; PDCP layer functionality associated with header compression/decompression and security (encryption, decryption, integrity protection, integrity checking); RLC layer functionality associated with transferring upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs into TBs, demuliplexing MAC SDUs from TBs, scheduling information reports, error correction through HARQ, priority management and logical channel prioritization.

[0056] Channel estimates obtained by a channel estimator 358 from a reference or return signal transmitted by the eNB 310 may be used by the TX processor 368 to select appropriate modulation and coding schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to the different antenna 352 via separate transmitters 354TX. Each 354TX transmitter can modulate an RF carrier with a respective spatial flow for transmission.

[0057] The UL transmission is processed in the eNB 310 in a manner similar to that described in relation to the receiver function in the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers the modulated information about a RF carrier and provides information to the RX 370 processor.

[0058] Controller/processor 375 may be associated with a memory 376 that stores program codes and data. Memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to retrieve IP packets from the UE 350. IP packets from the controller/ processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK) and/or NACK protocol to support HARQ operations.

[0059] Before gaining access to and communicating over a contention-based radio frequency spectrum band, a base station or UE may perform a Listen Before Talking (LBT) procedure to attempt access to the frequency spectrum band. shared radio. An LBT procedure may include performing a clear channel assessment (CCA) procedure to determine whether a channel in the contention-based shared radio frequency spectrum band is available. When it is determined that the channel of the contention-based shared radio frequency spectrum band is available, a channel reservation signal such as a channel usage beacon signal (CUBS) may be transmitted to reserve the channel.

[0060] There is an unmet need to coordinate an LBT procedure between base stations and UEs, where one base station helps coordinate the process for another (type of) BS. For example, there is a need for a licensed BS to support the unlicensed BS, or an unlicensed BS to support other unlicensed BS.

[0061] To coordinate an LBT procedure between base stations and UE, the present disclosure proposes a new potential set of adaptation rules for Load Based Equipment (LBE) based on Listen Before Talking (LBT). The LBT procedure of the present disclosure provides LTE-unlicensed (LTE-U) and Wi-Fi coexistence and DL/UL coexistence on both LTE-U and Wi-Fi.

[0062] FIG. 4 is an illustration of an example 400 of a wireless communication over an unlicensed radio frequency spectrum band, in accordance with various aspects of the present disclosure. FIG. 4 illustrates a downlink free channel assessment (CCA) procedure 402 may be performed by one or more base stations, such as one or more of the base stations 102 described with reference to FIG. 1 to reserve, for a period of time, a channel of the contention-based shared radio frequency spectrum band over which wireless communication occurs. Following a successful downlink CCA procedure 445 by a base station, the base station may transmit a preamble, such as a Wi-Fi preamble 404 and/or channel usage beacon signal (CUBS) 406 (e.g., a CUBS downlink (D-CUBS 450)) to provide an indication to other base stations or appliances (e.g. UEs, WiFi access points, etc.) that the base station has reserved the channel.

[0063] The eNB may then transmit a number of downlink subframes (D) 408. The eNB may transmit an indication of a number of DL subframes that it will transmit, for example, in FIG. 4, and an indication is provided by the eNB that it will transmit 6 D subframes. There may also be a special subframe (S) 410, which may be a transitional subframe, for example, between D and U subframes. Some of the D subframes may include a grant 410 to a UE(s) to transmit UL communication during several uplink subframes (U) 412. FIG. 4 illustrates the UL grants communicated to two different UEs, UE1 414 and UE2 416. The UE1 and UE2 may be, for example, one or more of the UEs 104 described above with reference to FIG. 1. Based on UL grant 410, UE1 414 and UE2 416 may perform a CCA or extended CCA (ECCA) 418 procedure, and, when successful, transmit a series of UL 412 subframes in accordance with UL grant 410 .

[0064] As indicated above, FIG. 4 is provided as an example. Other examples are possible and may differ from what has been described in connection with FIG. 4.

[0065] FIG. 5 is an illustration of an example 500 of a CCA procedure 515 performed by a transmitting apparatus when seeking access to a contention-based shared radio frequency spectrum band, in accordance with various aspects of the present disclosure. In some examples, the CCA procedure 515 may be an example of the CCA DL procedure 445 or CCA UL procedure 465 described with reference to FIG. 4. The CCA 515 procedure may have a fixed duration. In some examples, the CCA 515 procedure may be performed in accordance with an LBT frame-based equipment (LBT-FBE) protocol (e.g., the LBT-FBE protocol described by EN 301 893). Following the procedure of CCA 515, a channel reservation signal, such as a CUBS 520, may be transmitted, followed by a data transmission (e.g., a UL transmission or a DL transmission). By way of example, the data transmission may have a desired duration 505 of three subframes and an actual duration 510 of three subframes.

[0066] As indicated above, FIG. 5 is provided as an example. Other examples are possible and may differ from what has been described in connection with FIG. 5.

[0067] FIG. 6 is an illustration of an example 600 of an extended CCA (ECCA) procedure 615 performed by a transmitting apparatus when seeking access to a contention-based shared radio frequency spectrum band, in accordance with various aspects of the present disclosure. . In some examples, the ECCA procedure 615 may be an example of the CCA DL procedure 445 or CCA UL procedure 465 described with reference to FIG. 4. ECCA procedure 615 may include a random number of CCA procedures, and in some examples may include a plurality of CCA procedures. The ECCA 615 procedure may therefore have a variable duration. In some examples, the ECCA 615 procedure may be performed in accordance with an LBT load-based equipment (LBT-LBE) protocol (e.g., the LBT-LBE protocol described by EN 301 893). The ECCA 615 procedure may provide a greater probability of winning the contest to access the contest-based shared radio frequency spectrum band, but at the potential cost of shorter data transmission. Following the procedure of ECCA 615, a channel reservation signal, such as a CUBS 620, can be transmitted, followed by a data transmission. By way of example, the data transmission may have a desired duration 605 of three subframes and an actual duration 610 of two subframes.

[0068] As indicated above, FIG. 6 is provided as an example. Other examples are possible and may differ from what has been described in connection with FIG. 6.

[0069] A device, such as a UE, may have multiple antennas (N) to be used for receiving and/or transmitting signals. The device may divide the usage and assignment of the antennas to use for certain radio access technologies (RATs) such as LTE, Wi-Fi, etc., for certain frequency carriers, or both. For example, the device may use a fixed number of antennas for a carrier in cases of AC, or it may use a fixed number of antennas for WiFi when the device supports both Wi-Fi and other technologies such as LTE. In an example, the UE may have four antennas and assign two of the antennas for WiFi communication and two of the antennas for LTE communications. A device, such as a UE, can also dynamically or semi-statically select a number of antennas for a technology or a carrier (antenna selection). In such semi-static or dynamic schemes, sharing or selection may be triggered by a particular measurement result, such as a CQI, reference signal reception power (RSRP), and the like.

[0070] Communication networks, such as LTE, may have frequency division multiplexing (FDM) implementations and time division multiplexing (TDM) implementations. The sharing options in FDM implementations are not truly sharing different antennas, but rather sharing frequency spectrum received across the antenna. For example, a UE may use a duplexer/switch in order to use all antennas at the same time for different air interfaces. The duplexer/switch works like a filter, filtering out unwanted frequencies. However, in such FDM sharing schemes, there is typically a considerable loss in signal strength as signals are filtered. These losses can also increase with higher frequency bands. TDM implementations can actually use or assign separate antennas for each air interface/technology. Thus, when communications over these air interfaces/technologies are not in use, those antennas that have been assigned or designated for unused communications can be shared with other air interfaces/technologies. Various aspects of the present invention are directed to communication systems utilizing TDM implementations.

[0071] FIG. 7 is a diagram 700 illustrating communication between master devices and slave devices. A master device 702 and a master device 704 are each in communication with one or more of the slave devices 706-a, 706-b, 706-c and a UE 708 on an unlicensed channel 710 or a channel 712. The master device 702 and master device 704 may be in communication on a backhaul link 780.

[0072] Each of the devices illustrated in FIG. 1 (e.g., base stations 102 and UEs 104) can act as a master device or slave device. Some of the devices can operate in master mode or slave mode. When the device is operating in master mode, this device acts as a master device. When the device is operating in slave mode, this device acts as a slave device. For example, each of the base stations 102 can act as a master device. Each of the UEs 102 may act as a slave device.

[0073] The master device may have one or more slave devices associated with the master device. A slave device can be associated with one or more master devices. FIG. 7 shows, as an example, the master device 702 and the slave devices 706-a, 706-b, 706-c associated with each other in a first association. The master device 704 and the slave devices 706-a, 706-b, 706-c are associated with each other in a second association. The master device 702, the master device 704, and the slave device 706-a may be associated with each other in a third association. The master device 702 can operate on multiple channels. Furthermore, the master device 702 may operate in-band, out-of-band, or both.

[0074] Specifically, the master device 702 (e.g., the base stations 102) may communicate, on the unlicensed channel 710, with the slave devices 706-a, 706-b, 706-c (e.g., the UEs 104 ). Communication between the master device 702 and the slave devices 706-a, 706-b, 706-c on the unlicensed channel 710 can be considered as in-band communication of the master device and the associated slave devices. Additionally, the master device 702 may communicate with the UE 708 on channel 712. The master device 702 may also communicate with the slave device 706-a on channel 712. The channel 712 may be either a licensed channel or an unlicensed channel. licensed. Communication on channel 712 is out-of-band communication with respect to communication on unlicensed channel 710. Additionally, master device 704 and slave devices 706-a, 706-c may also communicate on unlicensed channel 710. In addition Furthermore, a master device can control the channel access behavior of each of the associated slave devices. For example, as described below, the master device 702 may send to the slave devices 706-a, 706-b, 706-c an indication that instructs the slave devices 706-a, 706-b, 706-c to perform a check procedure. ICCA, an ECCA procedure, or a deferral period to gain access to the unlicensed channel 710. During the deferral period, slave devices 706-a, 706-b, 706-c may postpone execution of a CCA procedure. The delay period may be a function of the type of traffic within the cell. The deferral period may be different for data and control information. Information indicating whether the slave devices 706-a, 706-b, 706-c use ICCA, ECCA, or a delay period may be communicated by the master device 702 on a common DL control channel (e.g., common PUCCH). In one aspect, the indication may include a common CRNTI (CCRNTI).

[0075] Additionally, the master devices can jointly control the channel access behavior of slave devices associated with all master devices. For example, the master device 702 and the master device 704 may jointly control the channel access behavior of the slave devices 706-a, 706-c. The operation of multiple master devices (e.g., master device 702 and master device 704), including channel access behavior, may be coordinated by a network controller. For example, LBT procedures can be dynamically changed for slave devices 706-a, 706-b, 706-c on master device 702.

[0076] Furthermore, a slave device can operate on multiple channels. For example, slave device 706-a operates on unlicensed channel 710 and channel 712. A slave device may be associated with more than one master device. For example, slave devices 706-a, 706-c are each associated with master device 702 and master device 704.

[0077] Additionally, a slave device may support dual connectivity. A slave device (e.g., slave device 706-a) may operate on a licensed channel (e.g., channel 712), or an unlicensed channel (e.g., unlicensed channel 710), or both. For example, slave device 706-a may communicate simultaneously or concurrently with master device 702 on unlicensed channel 710 and channel 712.

[0078] The associated master device and slave devices may support a coordinated multipoint procedure (CoMP). For example, the slave device 706-c can communicate with the master device 702 and the master device 704 via the CoMP procedure. The master device 702 and the master device 704 communicate on the backhaul link 780 to implement scheduling, transmission, reception, etc.

[0079] Additionally, multiple master devices can control functions of a slave device. For example, in a CoMP UL procedure, slave device 706-a or slave device 706-c may receive DL and UL grants from one of master device 702 and master device 704 and may transmit data in the UL to the other. The slave device 706-a or the slave device 706-c may receive from the master device 702 or the master device 704 an indication that instructs the slave device 706-a and the slave device 706-c to perform an ICCA procedure or an ECCA procedure to obtain access to the unlicensed channel 710. That is, both the master device 702 and the master device 704 can control the channel access behavior of the slave devices 706-a, 706-c.

[0080] FIG. 8 is a diagram 800 illustrating an ECCA procedure. The exemplary master device 702 or the exemplary slave device 706-a may perform the ECCA procedure to obtain a transmission partition 840 (or a transmission opportunity) on the unlicensed channel 710 to communicate with each other. Within the ECCA procedure, the master device 702 may observe, based on a contention window 820, a first idle observation partition 830-1, a second idle observation partition 830-2, observation partitions 832 (including observation partitions 830-m and occupied observation partitions 833), an ith idle observation partition 830-i, consecutive idle observation partitions 834, a j-th idle observation partition 830j, observation partitions 836 and an Nth idle observation partition 830-N.

[0081] The master device 702 or the slave device 706-a may determine the length of the contention window 820. Particularly, the contention window 820 may be determined between a maximum contention window size and a minimum contention window size . The master device 702 may determine the maximum contention window size and the minimum contention window size by itself. Additionally or alternatively, a network controller, for example, may configure the maximum contention window size and the minimum contention window size used by the master device 702. The slave device 706-a may determine the maximum window size dispute window and the minimum size of the dispute window itself. Additionally or alternatively, the master device 702 may configure the maximum contention window size and the minimum contention window size used by the slave device 706-a

[0082] The master device 702 may further determine the length of the contention window 820 based on the channel condition of the unlicensed channel 710. The master device 702 may determine the contention window 820 based on a configuration received from a controller. network. Particularly, the master device 702 may determine the contention window 820 semi-statically or dynamically by observing the channel condition and response/feedback reports sent by the slave device 706-a. For example, the master device 702 may monitor ACKs or negative acknowledgments (NACKs) sent by the slave device 706-a for data transmitted from the master device 702 to the slave device 706-a. Based on the ACKs and/or NACKs, the master device 702 may determine the channel condition of the unlicensed channel 710.

[0083] The slave device 706-a may also determine the length of the contention window 820 based on the channel condition of the unlicensed channel 710. The slave device 706-a may further determine the contention window 820 based on a configuration received from the master device 702. Particularly, the slave device 706-a may determine the contention window 820 semi-statically or dynamically by observing the channel condition and response/return reports sent by the master device 702. For example, the slave device 706 -a can monitor the ACKs or NACKs sent by the master device 702 to the data transmitted from the slave device 706-a to the master device 702. Based on the ACKs and NACKs, the slave device 706-a can determine the channel condition of the channel unlicensed 710.

[0084] When determining the length of the contention window 820, the master device 702 or the slave device 706-a may obtain a number N between 1 and the length of the contention window 820. For example, the master device 702 or the device slave 706-a may generate a random number N uniformly distributed between 1 and the length of the contention window 820. The value of N may be selected whenever an ECCA is performed and may be stored in a counter.

[0085] Subsequently, the master device 702 or the slave device 706-a may initiate an ECCA procedure, in which the master device 702 or the slave device 706-a observes that the unlicensed channel 710 is inactive for an observation period of N multiplied by an observation partition. An observation partition is the smallest unit of channel observation time and, for example, can be 20 μ*. That is, N defines the number of unoccupied (idle) observation partitions in a total idle observation period that need to be observed before the master device 702 or the slave device 706-a determines that the transmission partition 840 is obtained. The counter, whose initial value is N, is decremented each time an observation partition is considered unoccupied or inactive. The master device 702 or the slave device 706-a may consider that the unlicensed channel 710 should be occupied if the power level on the channel exceeds a threshold, which may be configurable in the master device 702 or the slave device 706-a. When the counter reaches 0, the master device 702 or the slave device 706-a may determine that it has obtained the transmission partition 840 and may transmit data in the transmission partition 840.

[0086] For example, under certain circumstances described below with reference to FIGs. 9-11, the master device 702 or the slave device 706-a can perform the ECCA procedure. Specifically, at time point t1, the master device 702 or the slave device 706-a may set the counter to N. In this example, after the time point t1, the master device 702 or the slave device 706-a observes the first idle watch partition 830-1 and the second idle watch partition 830-2, and decreases the counter by 2. That is, the counter is at N-2. Thereafter, the master device 702 or the slave device 706-a observes the observation partitions 832, which may include one or more occupied observation partitions 833 and one or more idle observation partitions 830-m. Thereafter, the master device 702 or the slave device 706-a may observe consecutive idle observation partitions 834, which begin at the ith idle observation partition 830-i and end at the jth idle observation partition 830-j. Thereafter, the master device 702 or the slave device 706-a watches the watch partitions 836, which may include one or more occupied watch partitions 833. The master device 702 or the slave device 706-a decrements the counter according to the idle watch partitions observed during the process. After observing the observation partitions 836, the counter is set to 1. Then, the master device 702 or the slave device 706-a observes the Nth idle observation partition 830-N, and the counter reaches 0. master device 702 or slave device 706-a, at time point t1, determines that it has obtained transmission partition 840 and can begin transmitting data in transmission partition 840.

[0087] In certain configurations, after the master device 702 or the slave device 706-a observes each occupied observation partition 833, the master device 702 or the slave device 706-a may optionally wait a delay period 837 before observe the next observation partition. The master device 702 may choose not to set the deferral period 837 or set the deferral period 837 to zero. If the deferral period 837 is not set to zero, the duration of the deferral period 837 may be the duration of one or more observation partitions. The master device 702 may also decide and configure the delay period 837 used by the slave device 706-a

[0088] FIG. 9 is a diagram 900 illustrating channel access procedures of a master device and a slave device on an unlicensed channel. The exemplary master device 702 may perform an ICCA procedure 932, an ECCA procedure 936, and an ECCA procedure 946 to obtain transmission partitions on the unlicensed channel 710 to communicate with the slave device 706-a. The master device 702 and the slave device 706-a may communicate subframes 938 on the unlicensed channel 710. In certain configurations, the master device 702 may communicate subframes 968, which may include a resource allocation 972 and a transmission partition indication 976 , with the slave device 706-a on channel 712, which may be a licensed channel or a different unlicensed channel. Furthermore, an AP 912 and an STA 916 may communicate packets 922, 924, 926, 928 on the unlicensed channel 710.

[0089] As shown, the master device 702 and the slave device 706-a share the unlicensed channel 710 with the AP 912 and the STA 916. In certain configurations, when the master device 702 or the slave device 706-a is inactive on the unlicensed channel 710, the master device 702 or the slave device 706-a is configured to perform an ICCA procedure initially to gain access to the channel. In the ICCA procedure, a device (e.g., master device 702 or slave device 706-a) observes the unlicensed channel 710 for a predetermined period of time (e.g., 1, 2, or 5 observation partitions) and determines whether the unlicensed channel 710 is idle for the predetermined period of time. When the unlicensed channel 710 is determined to be idle for the predetermined period of time, the master device 702 or the slave device 706-a may begin transmission on the unlicensed channel 710 immediately.

[0090] In this example, at time point t3, the master device 702 is idle on the unlicensed channel 710. The master device 702 still wants to communicate subframes 938 with the slave device 706-a. Accordingly, under this circumstance, the master device 702 consequently performs an ICCA procedure. In the ICCA procedure, the master device 702 observes the unlicensed channel 710 during the predetermined period of time, i.e., from time point t3 to time point t5, and determines whether the unlicensed channel 710 is idle in the period predetermined time. In this example, at time t0, the AP 912 and the STA 916 begin communicating packets 922 on the unlicensed channel 710. The transmission period of packets 922 overlaps with the predetermined time period of the ICCA procedure 932. Thus, the device master 702, in ICCA procedure 932, determines that the unlicensed channel 710 is busy.

[0091] In certain configurations, upon determining that the unlicensed channel 710 is busy in the ICCA procedure 932, the master device 702 may subsequently perform the ECCA procedure 936, as described above, to obtain a transmit partition. Specifically, the master device 702, at time point t5, begins executing the ECCA procedure 936. Subsequently, at time t7, the AP 912 and STA 916 begin communicating packets 924. At time t13, the AP 912 and The STA 916 begins communicating packets 926. Thus, in this example, just at time point t23, the ECCA procedure counter 936 as described above reaches 0. Consequently, at time point t23, the master device 702 determines that it has obtained a transmission partition and begins communicating subframes 938 with slave device 706-a. The subframes 938 may be the LBT radio structure 415.

[0092] In certain configurations, the transmission time of subframes 938 may be limited to a maximum channel occupancy duration, which is the maximum time for which a device can transmit continuously on an unlicensed channel. The device needs to perform another ECCA procedure to obtain a transmit partition again after transmitting for the maximum channel occupancy duration. In this example, the maximum channel occupancy duration lasts from time point t23 to time point t33. Consequently, at time point t33, the master device 702 performs the ECCA procedure 946 to obtain another transmission partition. In this example, the AP 912 and the STA 916 may communicate packets 928 on the unlicensed channel 710, which overlaps the time period of the ECCA procedure 946.

[0093] In another example, at time point t3, the slave device 706-a, rather than the master device 702, may want to transmit data to the other device. The slave device 706-a may perform operations similar to those described above with respect to the master device 702 (i.e., the ICCA procedure 932, the ECCA procedure 936, etc.) to obtain a transmission partition and then transmit data.

[0094] In certain configurations, as described above, the master device 702 and the slave device 706-a may communicate subframes 968 with each other on channel 712, simultaneously with communication on the unlicensed channel 710. Channel 712 may be a licensed channel or an unlicensed channel other than the unlicensed channel 710. In this example, the master device 702 and the slave device 706-a begin communication on channel 712 at time point t1. Before time point t3, the master device 702 may transmit resource allocation 972 (e.g., subframe allocation for LBT radio frame 415) for the unlicensed channel 710 to the slave device 706-a in subframes 968. Upon receiving resource allocation 972, slave device 706-a may perform an ICCA procedure and an ECCA procedure to obtain a transmission partition. In this example, the slave device 706-a executes the ICCA procedure 932 and the ECCA procedure 936 and consequently obtains a transmission partition at time point t23 as described above. Furthermore, at t23, the slave device 706-a may send a transmission partition indication 976 in subframes 968 on channel 712 to the master device 702 to indicate a transmission partition obtained on the unlicensed channel 710. Upon receiving the indication of the transmission partition 976, the master device 702 may begin transmitting, on the unlicensed channel 710, subframes 938 to the slave device 706-a.

[0095] FIG. 10 is a diagram 1000 illustrating master devices and a slave device communicating in accordance with a CoMP procedure. The exemplary master devices 702, 704 and the exemplary slave device 706-a are associated with each other. The master device 702 may perform an ICCA procedure 1022 and an ECCA procedure 1024 and may transmit a resource allocation 1026 to the slave device 706-a on the unlicensed channel 710. The slave device 706-a may perform an ECCA procedure 1034 and may communicate subframes 1038 with the master device 702 and/or the master device 704.

[0096] More specifically, at t1, the master device 702 determines to transmit, on the unlicensed channel 710, a resource allocation for the slave device 706-a to communicate with the master device 704 on the unlicensed channel 710 in accordance with a CoMP procedure. In this example, the master device 702 determines that it is idle on the unlicensed channel 710. That is, the master device 702 is not actively transmitting or receiving a signal on the unlicensed channel 710. Consequently, the master device 702 determines to perform a procedure of ICCA 1022 to obtain a transmission partition. Otherwise, the master device 702 may determine to perform an ECCA procedure to obtain the transmission partition. Additionally or alternatively, the master device 702 may determine that none of the master devices 702 and the devices associated with the master device 702, i.e., the master device 704 and the slave device 706-a, are active on the unlicensed channel 710 before Use the ICCA procedure to obtain the transmission partition. In other words, if any of the master device 702, master device 704, or slave device 706-a is active, the master device 702 may determine to perform an ECCA procedure to obtain a transmission partition.

[0097] In this example, the master device 702 determines that the unlicensed channel 710 is busy during the ICCA procedure 1022, as the transmission period of the packets 1012 transmitted between the AP 912 and the STA 916 overlaps the period of ICCA procedure time 1022. Subsequently, at time point t4, the master device 702 executes the ECCA procedure 1024 to obtain another transmission partition. Upon obtaining the transmission partition, from t7 to t8, the master device 702 transmits the resource allocation 1026 to the slave device 706-a on the unlicensed channel 710. The master device 702 may transmit information regarding the resource allocation 1026 to the master device 704 through the backhaul link 780 so that the master device 704 can communicate with the slave device 706-a in accordance with the CoMP procedure.

[0098] The resource allocation 1026 may direct the slave device 706-a to transmit data to the master device 704 immediately after receiving the resource allocation 1026 or at a specific point of time. At the transmission time point, the slave device 706-a can determine whether any of the slave devices 706-a and the associated devices (i.e., the master device 702 and the master device 704) are active on the unlicensed channel 710 or were active within a predetermined period of time (e.g., 1, 3, or 5 observation partitions). When one of the devices is active or was active for the predetermined period of time, the slave device 706-a may determine to perform the ECCA procedure to gain access to the unlicensed channel 710. In this example, based on resource allocation 1026, the slave device 706-a determines the transmission of data to the master device 702 immediately upon receipt of resource allocation 1026. The slave device 706-a further determines that the associated master device 702 was active at time point t8 and, consequently, performs the ECCA procedure 1034 to obtain a transmission partition on the unlicensed channel 710. The time period of the ECCA procedure 1034 may overlap with the transmission time period of the packets 1014 transmitted between the AP 912 and the STA 916. Through the ECCA procedure 1034, the slave device 706-a obtains a transmission partition at time point t12. Accordingly, at time point t12, slave device 706-a communicates subframes 1038 on unlicensed channel 710 to master device 704 in accordance with resource allocation 1026.

[0099] In another configuration, the resource allocation 1026 may be for the slave device 706 to communicate with the master device 702 on the unlicensed channel 710 as well. Particularly, in this example, resource allocation 1026 may allow master devices 702, 704 to use a CoMP joint reception procedure to receive UL subframes simultaneously and use a joint transmission procedure to transmit DL subframes to the slave device 706-a simultaneously.

[00100] FIG. 11 is another diagram 1100 illustrating master devices and a slave device communicating in accordance with a CoMP procedure. The exemplary master devices 702, 704 and the exemplary slave device 706-a are associated with each other. The master device 702 may communicate subframes 1168, which include a resource allocation 1172, with the slave device 706-a on channel 712. The channel 712 may be either a licensed channel or an unlicensed channel. The master device 704 may, on the unlicensed channel 710, perform an ICCA procedure 1142 and an ECCA procedure 1144, and may transmit signals 1146. The slave device 706 may perform an ICCA procedure 1132, an ICCA procedure 1152 and an ECCA procedure 1154 on the unlicensed channel 710. The slave device 706-a may communicate subframes 1138 and subframes 1158 with the master devices 702, 704 on the unlicensed channel 710 in accordance with a CoMP procedure.

[00101] In one aspect, channel 712 is a licensed channel. More specifically, at time point t1, the master device 702 communicates subframes 1168 on the unlicensed channel 712 with the slave device 706-a. Subframes 1168 include resource allocation 1172 for slave device 706-a to communicate with master device 704 on unlicensed channel 710 in accordance with a CoMP procedure. The master device 702 may transmit information regarding resource allocation 1172 to the master device 704 via the backhaul link 780 so that the master device 704 may communicate with the slave device 706-a in accordance with the procedure CoMP. The information may include an indication that instructs the master device 704 to reserve the unlicensed channel 710 in advance of and for use in data communication between the master device 704 and the slave device 706-a in accordance with resource allocation 1172. Such as master device 704 will reserve the unlicensed channel 710, the resource allocation 1172 may also include an indication that instructs the slave device 706-a to perform an ICCA procedure to gain access to the unlicensed channel 710.

[00102] Upon receiving the resource allocation information 1172 and accordingly determining the expected time point for receiving the UL transmission from the slave device 706-a on the unlicensed channel 710, the master device 704 may reserve the unlicensed channel 710 for expected communication in accordance with resource allocation 1172. Specifically, in this example, the master device 704, at time point t4, determines that it is idle on the unlicensed channel 710. Accordingly, the master device 704 determines to perform the ICCA 1142 procedure for the procedure for obtaining a transmission partition. Otherwise, the master device 704 may determine to perform an ECCA procedure to obtain the transmission partition. Additionally or alternatively, the master device 704 may determine whether any of the master devices 704 and the devices associated with the master device 704, i.e., the master device 702 and the slave device 706-a, are active on the unlicensed channel 710 before Use the ICCA procedure to obtain the transmission partition. If any of the master device 702, master device 704, or slave device 706-a is active, the master device 704 may determine to perform an ECCA procedure to obtain a transmission partition.

[00103] In this example, the master device 704 determines that the unlicensed channel 710 is busy during the ICCA procedure 1142, as the transmission period of the packets 1112 transmitted between the AP 912 and the STA 916 overlaps the period of ICCA procedure time 1142. Subsequently, at time point t6, the master device 702 executes the ECCA procedure 1144 to obtain another transmission partition. Upon obtaining the transmission partition, starting from time point t8, the master device 702 can transmit signals 1146 on the unlicensed channel 710 to occupy the channel until the expected UL transmission time (i.e., time point t10) to the slave device 706 transmits according to the resource allocation 1172.

[00104] Slave device 706-a receives resource allocation 1172 from subframes 1168 transmitted on licensed channel 712 from master device 702. Slave device 706-a also determines that resource allocation 1172 includes an indication to perform a ICCA to gain access to the channel. Accordingly, based on resource allocation 1172, slave device 706-a determines to execute ICCA procedure 1132 to obtain channel access at time point t10. Upon obtaining a transmission partition through the ICCA procedure 1132, at time point t12, the slave device 706-a transmits the subframes 1138 on the unlicensed channel 710 to the master device 704 in accordance with the resource allocation 1172.

[00105] In certain configurations, the master device 702 may further determine whether to include the ICCA procedure indication in the resource allocation 1172, the master device 702 based on the total channel occupancy time (i.e., from the time point t4 to time point t18) of the master device 704 and the associated devices (i.e., the slave device 706-a) on the unlicensed channel 710. The master device 702 can determine or estimate the length of the channel occupancy time. If the length is not greater than a preconfigured maximum channel occupancy duration (e.g., 10 ms), the master device 702 may determine to include the ICCA procedure indication in resource allocation 1172. If the length is greater than the maximum occupancy duration, the master device 702 may determine to include the ECCA procedure indication in the resource allocation 1172. Consequently, instead of executing the ICCA procedure 1132, the slave device 706-a may perform the ECCA to obtain the transmission partition.

[00106] In certain configurations, resource allocation 1172 may be for the slave device 706 to communicate with the master device 702 on the unlicensed channel 710 as well. Particularly, in this example, resource allocation 1172 may allow master devices 702, 704 to use a CoMP joint reception procedure to receive UL subframes simultaneously and use a joint transmission procedure to transmit DL subframes to the slave device 706-a simultaneously.

[00107] In certain configurations, resource allocation 1172 may also be for coordinated scheduling of slave device 706-a to communicate with master device 702 (or other master device) subsequent to communication of subframes 1138. Master device 702 may not reserve (or instruct the other master device to reserve) the unlicensed channel 710 for this communication. Thus, the master device 702 does not include in the resource allocation 1172 an indication that instructs the slave device 706-a to perform the ICCA procedure or the ECCA procedure to obtain a transmission partition for this subsequent communication. Based on resource allocation 1172, slave device 706-a may determine to gain access to unlicensed channel 710 at time point t24. Particularly, the slave device 706-a may determine whether any of the master devices 706-a and the devices associated with the slave device 706-a, i.e., the master device 702 and the slave device 704, are active or were active within the period of predetermined time on the unlicensed channel 710. If any of the master device 702, master device 704, or slave device 706-a is active, the master device 704 may determine to perform an ECCA procedure to obtain a transmission partition. In this example, the slave device 706-a determines that the unlicensed channel 710 is busy during the ICCA procedure 1152 as the transmission period of packets 1114 transmitted between the AP 912 and the STA 916 overlaps the period of time of the ICCA procedure 1152. Subsequently, at time point t26, the slave device 706-a executes the ECCA procedure 1154 to obtain a transmission partition. Upon obtaining the transmit partition, the master device 702 may, at time point t28, transmit the subframes 1158 on the unlicensed channel 710 to the master device 702 (or the other master device).

[00108] In another aspect, channel 712 is an unlicensed channel that is different from unlicensed channel 710. Slave device 706-a may determine the type of CCA procedure to be used on unlicensed channel 710 based on whether the resource allocation for the unlicensed channel 710 is transmitted to the slave device 706-a on the unlicensed channel 710 (i.e., the same unlicensed carrier) or on the unlicensed channel 712 (i.e., a different unlicensed carrier). . For example, as described above, when resource allocation 1026 is transmitted on unlicensed channel 710, slave device 706-a may determine to perform ECCA procedure 1034 to gain access to unlicensed channel 710. When resource allocation 1172 for the unlicensed channel 710 is transmitted on the unlicensed channel 712, in a manner similar to that described above, with respect to the licensed channel, the slave device 706-a may determine to perform ICCA, simple CCA or the ECCA procedure based on prior configuration information, an indication on resource allocation 1172, or based on transmission activity by the slave device 706-a or the master device 702 on the unlicensed channel 712.

[00109] FIG. 12 is a flowchart 1200 of a method (process) of operating a slave device (e.g., slave devices 706-a, 706-b, 706-c, apparatus 1402/1402'). The slave device can be associated with the first master device and a second master device.

[00110] At 1202, the slave device may receive, from the first master device, an allocation of resources for communication with the second master device. For example, with reference to FIG. 11, the master device 702 may communicate subframes 1168 that include a resource allocation 1172 with the slave device 706-a on channel 712. Channel 712 may be either a licensed channel or an unlicensed channel.

[00111] At 1204, the slave device may determine a type of CCA procedure to perform before communicating with the second master device on an unlicensed channel. For example, with reference to FIG. 11, the slave device 706-a may determine the type of CCA procedure to be used on the unlicensed channel 710 based on whether the resource allocation for the unlicensed channel 710 is transmitted to the slave device 706-a on the unlicensed channel 710. licensed 710 (i.e., the same unlicensed carrier) or on unlicensed channel 712 (i.e., a different unlicensed carrier). For example, as described above, when resource allocation 1026 is transmitted on unlicensed channel 710, slave device 706-a may determine to perform ECCA procedure 1034 to gain access to unlicensed channel 710. When resource allocation 1172 for the unlicensed channel 710 is transmitted on the unlicensed channel 712, in a manner similar to that described above, with respect to the licensed channel, the slave device 706-a may determine to perform ICCA, simple CCA or the ECCA procedure based on prior configuration information, an indication on resource allocation 1172, or based on transmission activity by the slave device 706-a or the master device 702 on the unlicensed channel 712.

[00112] At 1206, the slave device may perform a CCA procedure to obtain a transmission opportunity based on the determined type of CCA procedure. The CCA procedure can be either an ICCA procedure or an ECCA procedure. For example, with reference to FIG. 11, as described above, when the resource allocation 1026 is transmitted on the unlicensed channel 710, the slave device 706-a may determine to perform the ECCA procedure 1034 to obtain access to the unlicensed channel 710. When the resource allocation 1172 for the unlicensed channel 710 is transmitted on the unlicensed channel 712, in a manner similar to that described above, with respect to the licensed channel, the slave device 706-a may determine to perform ICCA, simple CCA or the information-based ECCA procedure configuration settings, an indication on resource allocation 1172, or based on transmission activity by the slave device 706-a or the master device 702 on the unlicensed channel 712.

[00113] At 1208, the slave device may transmit data to the second master device according to the resource allocation on the unlicensed channel when the transmission opportunity is obtained. For example, with reference to FIG. 10, the resource allocation 1026 may direct the slave device 706 to transmit data to the master device 704 immediately after receiving the resource allocation 1026 or at a specific point of time. At the transmission time point, the slave device 706-a can determine whether any of the slave devices 706-a and the associated devices (i.e., the master device 702 and the master device 704) are active on the unlicensed channel 710 or were active within a predetermined period of time (e.g., 1, 3, or 5 observation partitions). When one of the devices is active or was active for the predetermined period of time, the slave device 706-a may determine to perform the ECCA procedure to gain access to the unlicensed channel 710. In this example, based on resource allocation 1026, the slave device 706-a determines the transmission of data to the master device 702 immediately upon receipt of resource allocation 1026. The slave device 706-a further determines that the associated master device 702 was active at time point t8 and, consequently, performs the ECCA procedure 1034 to obtain a transmission partition on the unlicensed channel 710. The time period of the ECCA procedure 1034 may overlap with the transmission time period of the packets 1014 transmitted between the AP 912 and the STA 916. Through the ECCA procedure 1034, the slave device 706-a obtains a transmission partition at time point t12. Accordingly, at time point t12, slave device 706-a communicates subframes 1038 on unlicensed channel 710 to master device 704 in accordance with resource allocation 1026.

[00114] FIG. 13 is a conceptual data flowchart 1300 illustrating the flow of data between different media/components in an exemplary apparatus 1302. The apparatus may be a UE. The apparatus includes a receiving component 1304 that receives a resource allocation 1305 from a first master device 1350. The apparatus also includes a determining component 1306 that determines a type of CCA procedure (e.g., ICCA or ECCA) to execute before of communicating with the second master device on an unlicensed channel based on information associated with resource allocation 1315 received from the receiving component 1304. The apparatus further includes a CCA performance component 1308 that performs a CCA procedure 1335 to obtain a transmission opportunity based on information received from the determining component 1306. The apparatus further includes a transmission component 1310 that transmits the data 1355 to a second master device 1360 using the transmission opportunity 1345.

[00115] The apparatus may include additional components that perform each of the algorithm blocks in the flowchart mentioned above in FIG. 12. As such, each block in the above-mentioned flowchart of FIG. 12 can be realized through a component and the apparatus can include one or more of said components. The components may be one or more hardware components specifically configured to perform the indicated process/algorithm, implemented by a processor configured to perform the indicated processes/algorithm, stored within a computer-readable medium for execution by a processor, or some combination thereof.

[00116] FIG. 14 is a diagram 1400 illustrating an example of a hardware implementation for an apparatus 1302' that employs a processing system 1414. The processing system 1414 may be implemented with a bus architecture, generally represented by bus 1424. The bus 1424 may include any number of interconnect buses and bridges depending on the specific application of the 1414 processing system and general design constraints. Bus 1424 connects together various circuits, including one or more processors and/or hardware components, represented by processor 1404), components 1304, 1306, 1308, 1310, and the computer-readable medium/memory 1406. Bus 1424 can also connect various other circuits, such as timing sources, peripherals, voltage regulators and power management circuits, which are well known in the art, and therefore will not be described later.

[00117] The processing system 1414 may be coupled to a transceiver 1410. The transceiver 1410 is coupled to one or more antennas 1420. The transceiver 1410 provides a means for communicating with various other devices via a transmission medium. The transceiver 1410 receives a signal from one or more antennas 1420, extracts information from the received signal, and provides the extracted information to the processing system 1414, specifically the receiving component 1304. Additionally, the transceiver 1410 receives the information from the processing system 1414, specifically the transmission module 1310, and based on the information received, generates a signal to be applied to one or more antennas 1420. The processing system 1414 includes a processor 1404 coupled to a medium/memory computer-readable medium 1406. Processor 1404 is responsible for general processing, including executing software stored on computer-readable medium/memory 1406. The software, when executed by processor 1404, causes processing system 1414 to perform various functions described above for any particular device. The computer-readable medium/memory 1406 may also be used for storing data that is manipulated by the processor 1404 when executing the software. The processing system 1414 further includes at least one of the components 1304, 1306, 1308 and 1310. The components may be software components running on the processor 1404, resident/stored in the computer readable medium/memory 1406, one or more components of hardware coupled to the processor 1404, or some combination thereof. The processing system 1414 may be a component of the UE 350 and may include memory 360 and/or at least one of TX processor 368, RX processor 356 and controller/processor 359.

[00118] In one configuration, the apparatus 1302/1302' for wireless communication includes means for receiving, from the first master device, a resource allocation for communication with the second master device. In one aspect, the resource allocation is received on at least one of an unlicensed channel or a licensed channel. In another embodiment, the apparatus 1302/1302' for wireless communication includes means for determining a type of CCA procedure to perform before communicating with the second master device on an unlicensed channel. In one aspect, the means for determining is configured to determine the type of CCA procedure to perform based on at least one of an indicator included in the resource allocation, configuration information provided by the first master device prior to receiving the resource allocation. , whether the first master device or the second master device reserved the unlicensed channel for transmission by the slave device, whether the resource allocation was received on the unlicensed channel or another channel, or whether the resource allocation was received on the unlicensed channel, or on a licensed channel. For example, the other channel may include a different unlicensed channel, the same unlicensed channel, or a licensed channel. In a further embodiment, the apparatus 1302/1302' for wireless communication includes means for further performing a CCA procedure to obtain a transmission opportunity based on the determination, the CCA procedure being one of an ICCA procedure or a ECCA. In yet another embodiment, the apparatus 1302/1302' for wireless communication includes means for transmitting data to the second master device in accordance with the resource allocation on the unlicensed channel when the transmission opportunity is obtained. In one aspect, the resource allocation is still for communication with the first master device. In another aspect, the means for transmission is configured to transmit the data to the first master device in accordance with the resource allocation. In another aspect, the means for transmission is configured to transmit other data to the first master device in accordance with resource allocation. For example, the other data may include control data and/or user data. In yet another aspect, the slave device is user equipment. In another aspect, the first master device includes a first eNB macro, a first RRH, or a first femto cell. In another aspect, the second master device includes one of a second eNB, a second RRH, or a second femto cell. The aforementioned means may be one or more of the aforementioned components of the apparatus 1302 and/or the processing system 1414 of the apparatus 1302' configured to perform the functions recited by the aforementioned means. As described above, the processing system 1414 may include the TX processor 368, the RX processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX processor 368, the RX processor 356 , and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

[00119] It is understood that the specific order or hierarchy of blocks in the disclosed processes/flowcharts is an illustration of exemplary approaches. Based on design preferences, it is understood that the order or hierarchy of blocks in specific processes/flowcharts may be changed. Additionally, some blocks can be combined or omitted. The accompanying method claims present elements of various blocks in a sample order, and are not intended to be limited to the specific order or hierarchy presented.

[00120] FIG. 15 is a flowchart 1500 of a wireless communication method. The method can be performed by an eNB (e.g., the master device 702, the device 1502/1502'). It should be understood that the operations indicated with dashed lines represent optional operations for various aspects of the disclosure.

[00121] At 1502, the eNB may transmit a resource allocation to a slave device. For example, with reference to FIG. 11, the master device 702 may communicate subframes 1168 that include a resource allocation 1172 with the slave device 706-a on channel 712. Channel 712 may be either a licensed channel or an unlicensed channel.

[00122] At 1504, the eNB may transmit resource allocation information to the second master device on a backhaul link. For example, with reference to FIG. 11, the master device 702 may transmit resource allocation information 1172 to the master device 704 via the backhaul link 780 so that the master device 704 may communicate with the slave device 706-a in accordance with the CoMP procedure. The information may include an indication that instructs the master device 704 to reserve the unlicensed channel 710 in advance of and for use in data communication between the master device 704 and the slave device 706-a in accordance with resource allocation 1172. Such as master device 704 will reserve the unlicensed channel 710, the resource allocation 1172 may also include an indication that instructs the slave device 706-a to perform an ICCA procedure to gain access to the unlicensed channel 710.

[00123] At 1506, the eNB may indicate a CCA type and CCA parameters for the slave device. For example, FIG. 11, the slave device 706-a may perform an ICCA procedure 1132, an ICCA procedure 1152, and an ECCA procedure 1154 on the unlicensed channel 710. The eNB may also indicate other configuration parameters, such as the delay period, value of the ECA counter, etc.

[00124] At 1508, the eNB may provide configuration information in a communication prior to transmitting the resource allocation. For example, with reference to FIG. 11, when the resource allocation 1172 for the unlicensed channel 710 is transmitted on the unlicensed channel 712, in a manner similar to that described above, with respect to the licensed channel, the slave device 706-a may determine to perform the ICCA, the CCA simple or the ECCA procedure based on previous configuration information, an indication in resource allocation 1172, or based on transmission activity by the slave device 706-a or the master device 702 on the unlicensed channel 712.

[00125] At 1510, the eNB may configure an indicator on resource allocation. For example, with reference to FIG. 11, when the resource allocation 1172 for the unlicensed channel 710 is transmitted on the unlicensed channel 712, in a manner similar to that described above with respect to the licensed channel, the slave device 706-a may determine to perform the ICCA procedure of the CCA simple or ECCA based on previous configuration information, an indication in resource allocation 1172, or based on transmission activity by the slave device 706-a or the master device 702 on the unlicensed channel 712. The master device 702 may further determine whether to include the indication of the ICCA procedure in the resource allocation 1172 of the master device 702 based on the total channel busy time (i.e., from time point t4 to time point t18) of the master device 704 and the associated devices (i.e., from time point t4 to time point t18) is, the slave device 706-a) on the unlicensed channel 710. The master device 702 can determine or estimate the length of the channel occupancy time. If the length is not greater than a preconfigured maximum channel occupancy duration (e.g., 10 ms), the master device 702 may determine to include the ICCA procedure indication in resource allocation 1172. If the length is greater than the maximum occupancy duration, the master device 702 may determine to include the ECCA procedure indication in the resource allocation 1172. Consequently, instead of executing the ICCA procedure 1132, the slave device 706-a may perform the ECCA to obtain the transmission partition.

[00126] At 1512, the eNB may transmit resource allocation on a channel type. For example, with reference to FIG. 11, the master device 702 may communicate subframes 1168 that include a resource allocation 1172 with the slave device 706-a on channel 712. Channel 712 may be either a licensed channel or an unlicensed channel.

[00127] At 1514, the eNB may transmit resource allocation on a selected channel. For example, with reference to FIG. 11, the master device 702 may communicate subframes 1168 that include a resource allocation 1172 with the slave device 706-a on channel 712. Channel 712 may be either a licensed channel or an unlicensed channel.

[00128] At 1516, the eNB may determine that at least one of the first master device, second master device, and slave device is active on the unlicensed channel prior to receiving the data. For example, with reference to FIG. 11, the master device 702 may determine that none of the master devices 702 and the devices associated with the master device 702, i.e., the master device 704 and the slave device 706-a, are active on the unlicensed channel 710 before using the procedure from ICCA to obtain the transmission partition. In other words, if any of the master device 702, master device 704, or slave device 706-a is active, the master device 702 may determine to perform an ECCA procedure to obtain a transmission partition.

[00129] FIG. 16 is a conceptual data flowchart 1600 illustrating the flow of data between different media/components in an exemplary apparatus 1602. The apparatus may be an eNB. The apparatus includes a receiving component 1604 that receives data transmission 1605, 1615 from a slave device 1650 and a master eNB 1660. Additionally, the apparatus includes an indicating component 1606 that indicates a CCA type and CCA parameters 1625 for the slave device 1650. The apparatus further includes a transmission component 1608 that transmits the CCA type, CCA parameters, and resource allocation 1635 to the slave device 1650. Additionally, the transmission component 1608 transmits information 1645 regarding to resource allocation for the master device 1660.

[00130] The apparatus may include additional modules that perform each of the steps of the algorithm in the above-mentioned flow diagram of Figure 15. As such, each block in the above-mentioned flow diagram of FIG. 15 can be realized through a component and the apparatus can include one or more of said components. The components may be one or more hardware components specifically configured to perform the indicated process/algorithm, implemented by a processor configured to perform the indicated processes/algorithm, stored within a computer-readable medium for execution by a processor, or some combination thereof.

[00131] FIG. 17 is a diagram 1700 illustrating an example of a hardware implementation for an apparatus 1602' that employs a processing system 1714. The processing system 1714 may be implemented with a bus architecture, generally represented by the bus 1724. The bus 1724 may include any number of interconnect buses and bridges depending on the specific application of the 1714 processing system and general design constraints. Bus 1724 connects together various circuits, including one or more processors and/or hardware components, represented by processor 1704), components 1604, 1606, 1608, and the computer/memory readable medium 1706. Bus 1724 can also connect various other circuits, such as timing sources, peripherals, voltage regulators and power management circuits, which are well known in the art, and therefore will not be described further.

[00132] The processing system 1714 may be coupled to a transceiver 1710. The transceiver 1710 is coupled to one or more antennas 1720. The transceiver 1710 provides a means for communicating with various other devices via a transmission medium. The transceiver 1710 receives a signal from one or more antennas 1720, extracts information from the received signal, and provides the extracted information to the processing system 1714, specifically the receiving component 1604. Additionally, the transceiver 1710 receives the information from the processing system 1714, specifically the transmission component 1606, and based on the information received, generates a signal to be applied to one or more antennas 1720. The processing system 1714 includes a processor 1704 coupled to a medium/memory computer-readable medium 1706. Processor 1704 is responsible for general processing, including executing software stored on computer-readable medium/memory 1706. The software, when executed by processor 1704, causes processing system 1714 to perform various functions described above for any particular device. The computer readable medium/memory 1706 may also be used for storing data that is manipulated by the processor 1704 when executing the software. The processing system 1714 further includes at least one of the components 1604, 1606, 1608. The components may be software components running on the processor 1704, resident/stored in the computer readable medium/memory 1706, one or more hardware components coupled to the 1704 processor, or some combination thereof. The processing system 1714 may be a component of the eNB 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

[00133] In one configuration, the apparatus 1602/1602' for wireless communication includes means for transmitting a resource allocation to a slave device for communication with the second master device. In another embodiment, the apparatus 1602/1602' for wireless communication includes means for transmitting resource allocation information to the second master device on a backhaul link. In a further embodiment, the apparatus 1602/1602' for wireless communication includes means for indicating a CCA type and CCA parameters for the slave device. In one aspect, the means for indicating is configured to provide configuration information in a communication prior to transmitting the resource allocation. In another aspect, the means for indicating is configured to define an indicator in resource allocation. In a further aspect, the means for indicating is configured to convey resource allocation on a channel type. In yet another aspect, the means for indicating is configured to convey resource allocation on a selected channel. In one aspect, the slave device is user equipment. In another aspect, the first master device includes a first macro eNB, a first radio RRH, or a first femto cell. In another aspect, the second master device includes one of a second eNB, a second RRH, or a second femto cell.

[00134] The aforementioned means may be one or more of the aforementioned components of the apparatus 1602 and/or the processing system 1714 of the apparatus 1602' configured to perform the functions recited by the aforementioned means. As described above, the processing system 1714 may include the TX processor 316, the RX processor 370, and the controller/processor 375. As such, in one configuration, the aforementioned means may be the TX processor 316, the RX processor 370 , and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

[00135] FIG. 18 is a flowchart 1800 of a wireless communication method. The method can be performed by an eNB (e.g., the master device 704, the device 1502/1502'). It should be understood that the operations indicated with dashed lines represent optional operations for various aspects of the disclosure.

[00136] At 1802, the eNB may receive, from the second master device, resource allocation information for the first master device on a backhaul link. For example, with reference to FIG. 11, the master device 702 may transmit resource allocation information 1172 to the master device 704 via the backhaul link 780 so that the master device 704 may communicate with the slave device 706-a in accordance with the CoMP procedure. The information may include an indication that instructs the master device 704 to reserve the unlicensed channel 710 in advance of and for use in data communication between the master device 704 and the slave device 706-a in accordance with resource allocation 1172. Such as master device 704 will reserve the unlicensed channel 710, the resource allocation 1172 may also include an indication that instructs the slave device 706-a to perform an ICCA procedure to gain access to the unlicensed channel 710.

[00137] At 1804, the eNB may receive data according to resource allocation on an unlicensed channel of the slave device. For example, with reference to FIG. 10. For example, with reference to FIG. 10, the resource allocation 1026 may direct the slave device 706-a to transmit data to the master device 704 immediately after receiving the resource allocation 1026 or at a specific point of time. At the transmission time point, the slave device 706-a can determine whether any of the slave devices 706-a and the associated devices (i.e., the master device 702 and the master device 704) are active on the unlicensed channel 710 or were active within a predetermined period of time (e.g., 1, 3, or 5 observation partitions). When one of the devices is active or was active for the predetermined period of time, the slave device 706-a may determine to perform the ECCA procedure to gain access to the unlicensed channel 710. In this example, based on resource allocation 1026, the slave device 706-a determines the transmission of data to the master device 702 immediately upon receipt of resource allocation 1026. The slave device 706-a further determines that the associated master device 702 was active at time point t8 and, consequently, performs the ECCA procedure 1034 to obtain a transmission partition on the unlicensed channel 710. The time period of the ECCA procedure 1034 may overlap with the transmission time period of the packets 1014 transmitted between the AP 912 and the STA 916. Through the ECCA procedure 1034, the slave device 706-a obtains a transmission partition at time point t12. Accordingly, at time point t12, slave device 706-a communicates subframes 1038 on unlicensed channel 710 to master device 704 in accordance with resource allocation 1026.

[00138] At 1806, the eNB may perform, on the first master device, an ICCA procedure or an ECCA procedure to obtain a transmission opportunity on the unlicensed channel prior to receiving the data. For example, with reference to FIG. 11, the master device 704 determines that the unlicensed channel 710 is busy during the ICCA procedure 1142 as the transmission period of the packets 112 transmitted between the AP 912 and the STA 916 overlaps with the time period of the ICCA procedure 1142. ICCA 1142. Subsequently, at time point t6, the master device 702 performs the ECCA procedure 1144 to obtain another transmission partition. Upon obtaining the transmission partition, starting from time point t8, the master device 702 can transmit signals 1146 on the unlicensed channel 710 to occupy the channel until the expected UL transmission time (i.e., time point t10) to the slave device 706 transmits according to the resource allocation 1172.

[00139] At 1808, the eNB may occupy, by the first master device, the unlicensed channel in the transmission opportunity. For example, with reference to FIG. 11, upon obtaining the transmission partition, starting from time point t8, the master device 702 can transmit signals 1146 on the unlicensed channel 710 to occupy the channel until the expected UL transmission time (i.e., time point t10 ) for slave device 706-to transmit according to resource allocation 1172.

[00140] FIG. 19 is a conceptual data flowchart 1900 illustrating the flow of data between different media/components in an exemplary apparatus 1902. The apparatus may be an eNB. The apparatus includes a receiving component 1904 that receives information 1905 associated with a resource allocation of a slave device from a master device 1950. Additionally, the receiving component 1904 receives data transmissions 1915 from the slave device 1960 in a licensed or unlicensed channel. Additionally, the apparatus includes CCA performance component 1906 that performs an ICCA procedure or an ECCA procedure to obtain a transmission opportunity on the unlicensed channel prior to reception of the data transmissions. In one aspect, the CCA performance component 1906 may use information associated with the resource allocation 1925 received from the receive component 1904 to obtain the transmission opportunity. The apparatus also includes an occupancy component 1908 that occupies the unlicensed channel at transmission opportunity 1945 based on information associated with ICCA/ECCA 1935. The apparatus further includes a transmission component 1910 that sends data transmissions 1955, 1965 to a 1950 master device and a 1960 slave device.

[00141] The apparatus may include additional modules that perform each of the steps of the algorithm in the above-mentioned flow diagram of Figure 18. As such, each block in the above-mentioned flow diagram of FIG. 18 can be realized through a component and the apparatus can include one or more of said components. The components may be one or more hardware components specifically configured to perform the indicated process/algorithm, implemented by a processor configured to perform the indicated processes/algorithm, stored within a computer-readable medium for execution by a processor, or some combination thereof.

[00142] FIG. 20 is a diagram 2000 illustrating an example of a hardware implementation for an apparatus 1902' that employs a processing system 2014. The processing system 2014 may be implemented with a bus architecture, generally represented by bus 2024. The bus 2024 may include any number of interconnect buses and bridges depending on the specific 2014 processing system application and general design constraints. Bus 2024 connects together various circuits, including one or more processors and/or hardware components, represented by processor 2004), components 1904, 1906, 1908, 1910, and the computer-readable medium/memory 2006. Bus 2024 can also connect various other circuits, such as timing sources, peripherals, voltage regulators and power management circuits, which are well known in the art, and therefore will not be described later.

[00143] The processing system 2014 may be coupled to a transceiver 2010. The transceiver 2010 is coupled to one or more antennas 2020. The transceiver 2010 provides a means for communicating with various other devices via a transmission medium. The transceiver 2010 receives a signal from one or more antennas 2020, extracts information from the received signal, and provides the extracted information to the processing system 2014, specifically the receiving component 1904. Additionally, the transceiver 2010 receives the information from the processing system 2014, specifically the transmission component 1910, and based on the information received, generates a signal to be applied to one or more antennas 2020. The processing system 2014 includes a processor 2004 coupled to a medium/memory computer-readable medium 2006. The processor 2004 is responsible for general processing, including executing software stored on the computer-readable medium/memory 2006. The software, when executed by the processor 2004, causes the processing system 2014 to perform various functions described above for any particular device. The computer readable medium/memory 2006 can also be used for storing data that is manipulated by the processor 2004 when executing the software. The processing system 2014 further includes at least one of the components 1904, 1906, 1908 and 1910. The components may be software components running on the processor 2004, resident/stored in the computer readable medium/memory 2006, one or more components hardware coupled to the 2004 processor, or some combination thereof. The processing system 2014 may be a component of the eNB 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

[00144] In one configuration, the apparatus 1902/1902' for wireless communication includes means for receiving, from the second master device, resource allocation information for the second master device on a backhaul link. In one aspect, the resource allocation is transmitted on a licensed channel, and the resource allocation information includes an indication to reserve the unlicensed channel. In another embodiment, the apparatus 1902/1902' for wireless communication includes means for receiving data in accordance with resource allocation on an unlicensed channel from the slave device. In another aspect, the apparatus 1902/1902' for wireless communication includes means for performing, on the first master device, an ICCA procedure or an ECCA procedure to obtain a transmission opportunity on the unlicensed channel prior to receiving the data. In another configuration, the apparatus 1902/1902' for wireless communication includes means for occupying, by the master device, the unlicensed channel at the transmission opportunity. In one aspect, the slave device is user equipment. In another aspect, the first master device includes a first eNB macro, a first RRH, or a first femto cell. In another aspect, the second master device includes one of a second eNB, a second RRH, or a second femto cell. The aforementioned means may be one or more of the aforementioned components of the apparatus 1902 and/or the processing system 2014 of the apparatus 1902' configured to perform the functions recited by the aforementioned means. As described above, the processing system 2014 may include the TX processor 316, the RX processor 370, and the controller/processor 375. As such, in one configuration, the aforementioned means may be the TX processor 316, the RX processor 370 , and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

[00145] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein, but are to be in accordance with the full scope consistent with the claims of the language, with reference to an element in the singular not being intended to mean “one and only one” unless which specifically so stated, but instead “one or more.” The word “exemplary” is used here to mean “serving as an example, case, or illustration.” Any aspect described here as “exemplary” should not necessarily be construed as preferred or advantageous over other aspects. Unless specifically indicated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B or C”, “one or more of A, B or C”, “at least one of A, B or C”, “one or more of A, B and C” and “A, B, C, or any combination thereof” includes any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A , B, or C”, “one or more of A, B, or C”, “at least one of A, B, and C”, “one or more of A, B, and C” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to elements of the various aspects described throughout this disclosure, which are known or will later become known to those skilled in the art are expressly incorporated herein by reference and are intended to be encompassed for the demands. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. The words “module”, “mechanism”, “element”, “device” and the like may not be substitutes for the word “means”. Thus, no claim element should be construed as a means plus function unless the element is expressly recited using the phrase “means to.”

Claims (11)

1. Method (1200) of wirelessly communicating a slave device (706-a), wherein the slave device (706-a) is associated with a first master device (702) and a second master device (704), characterized in that the slave device is a user equipment, the first master device includes one of a first Evolved Node B macro, eNB, a first radio resource head, RRH, or a first femto cell, and wherein the second master device includes one of a second eNB, a second RRH or a second femto cell, the method comprising: receiving (1202), from the first master device (702), an allocation of resources (1172) for communicating with the second device master (704); determining (1204) a type of clear channel evaluation procedure, CCA, to perform before communicating with the second master device (704) on an unlicensed channel; performing (1206) a CCA procedure to obtain a transmission opportunity based on the determination, the CCA procedure being one of an initial CCA procedure, ICCA, or an extended CCA procedure, ECCA; and transmitting (1208) data to the second master device according to the resource allocation on the unlicensed channel when the transmission opportunity is obtained. 2. Method according to claim 1, characterized by the fact that the slave device determines the type of CCA procedure to perform based on at least one of: an indicator included in the resource allocation, configuration information provided by the first master device before receiving the resource allocation, whether the first master device or the second master device reserved the unlicensed channel for transmission by the slave device, whether the resource allocation was received on the unlicensed channel or another channel, or whether the resource allocation was received on the unlicensed channel or a licensed channel. 3. The method of claim 1, wherein the resource allocation is received on at least one of the unlicensed channel or a licensed channel. 4. The method of claim 1, wherein the resource allocation further serves to communicate with the first master device, wherein the transmission further includes transmitting the data to the first master device in accordance with the resource allocation. resources. 5. The method of claim 1, wherein the resource allocation further serves to communicate with the first master device, wherein the transmission further includes transmitting other data to the first master device in accordance with the resource allocation. resources. 6. Apparatus (1300) for wireless communication, wherein the apparatus is a slave device that is associated with a first master device and a second master device, characterized in that the slave device is user equipment, the first device master includes one of a first Evolved Node B macro, eNB, a first radio resource head, RRH, or a first femto cell, and wherein the second master device includes one of a second eNB, a second RRH, or a second femto cell, the apparatus comprising: means (1304) for receiving, from the first master device, an allocation of resources for communication with the second master device; means (1306) for determining a type of clear channel evaluation, CCA, procedure to perform before communicating with the second master device on an unlicensed channel; means (1308) for performing a CCA procedure to obtain a transmission opportunity based on the determination, the CCA procedure being one of an initial CCA procedure, ICCA, or an extended CCA procedure, ECCA; and means (1310) for transmitting data to the second master device in accordance with the resource allocation on the unlicensed channel when the transmission opportunity is obtained. 7. Apparatus according to claim 6, characterized by the fact that the means for determining are configured to determine the type of CCA procedure to perform based on at least one of the following factors: an indicator included in the resource allocation, information of configuration provided by the first master device before receiving the resource allocation, if the first master device or the second master device reserved the unlicensed channel for transmission by the slave device, if the resource allocation was received on the unlicensed channel or on another channel, or if the resource allocation was received on the unlicensed channel on the licensed channel. 8. The apparatus of claim 6, wherein the resource allocation is received on at least one of the unlicensed channel and a licensed channel. 9. The apparatus of claim 6, wherein the resource allocation is additionally for communicating with the first master device, wherein the means for transmission is configured to transmit the data to the first master device in accordance with the allocation. of resources. 10. The apparatus of claim 6, wherein the resource allocation is further to communicate with the first master device, wherein the means for transmission is configured to transmit other data to the first master device in accordance with the allocation. of resources. 11. Computer-readable memory comprising instructions stored therein, the instructions being executable by a computer to perform the method steps as defined in any one of claims 1 to 5.