WO2018058597A1 - Signalisation d'autorisation de canal de liaison montante autonome multefire - Google Patents

Signalisation d'autorisation de canal de liaison montante autonome multefire Download PDF

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Publication number
WO2018058597A1
WO2018058597A1 PCT/CN2016/101243 CN2016101243W WO2018058597A1 WO 2018058597 A1 WO2018058597 A1 WO 2018058597A1 CN 2016101243 W CN2016101243 W CN 2016101243W WO 2018058597 A1 WO2018058597 A1 WO 2018058597A1
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WIPO (PCT)
Prior art keywords
channel clearance
clearance signal
autonomous uplink
uplink mode
channel
Prior art date
Application number
PCT/CN2016/101243
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English (en)
Inventor
Peng Cheng
Vinay Chande
Arumugam Chendamarai Kannan
Chirag Patel
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Qualcomm Incorporated
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Qualcomm Incorporated filed Critical Qualcomm Incorporated
Priority to PCT/CN2016/101243 priority Critical patent/WO2018058597A1/fr
Priority to PCT/CN2017/102865 priority patent/WO2018059311A1/fr
Priority to CN201780060045.XA priority patent/CN109792753B/zh
Priority to EP17854761.8A priority patent/EP3520527B1/fr
Priority to US16/326,290 priority patent/US11576206B2/en
Publication of WO2018058597A1 publication Critical patent/WO2018058597A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
    • H04W74/0816—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA] with collision avoidance

Definitions

  • the following relates generally to wireless communication and more specifically to autonomous uplink channel clearance signaling for mobile devices in an unlicensed radio frequency spectrum band.
  • Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) .
  • multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system) .
  • CDMA code division multiple access
  • TDMA time division multiple access
  • FDMA frequency division multiple access
  • OFDMA orthogonal frequency division multiple access
  • LTE Long Term Evolution
  • a wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .
  • UE user equipment
  • multiple nodes may attempt to access a medium by sending a messages to other nodes. Once a node wins access to the medium, the node may communicate with the other nodes over the medium for a given time.
  • a neighboring node such as a UE may be unaware that the medium is occupied. The UE may thus operate without recognizing constraints on the medium or without regard to interference that it might cause to other nodes.
  • a user equipment (UE) operating in a shared or unlicensed radio frequency spectrum band may initiate a channel clearance procedure before transmitting other uplink messages in order to confirm channel availability and avoid interference.
  • the UE may operate in an autonomous uplink mode, which may support unscheduled uplink transmissions in an unlicensed radio frequency spectrum band.
  • the UE may transmit a first channel clearance signal (e.g., a request-to-send message) to a base station in the unlicensed radio frequency spectrum band.
  • the base station may transmit a second channel clearance signal (e.g., a clear-to-send message) to the UE which, in some cases, may include control information.
  • the UE may transmit an uplink message in the autonomous uplink mode with confidence that the medium is available for transmission to the base station.
  • a method of wireless communication may include selecting an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, wherein the autonomous uplink mode supports unscheduled uplink transmissions (e.g., non-scheduled uplink transmissions) , transmitting a first channel clearance signal based at least in part on selecting the autonomous uplink mode, receiving a second channel clearance signal from a base station in response to the first channel clearance signal, and transmitting an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, wherein the uplink message is transmitted based at least in part on receiving the second channel clearance signal.
  • unscheduled uplink transmissions e.g., non-scheduled uplink transmissions
  • the apparatus may include means for selecting an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, wherein the autonomous uplink mode supports unscheduled uplink transmissions, means for transmitting a first channel clearance signal based at least in part on selecting the autonomous uplink mode, means for receiving a second channel clearance signal from a base station in response to the first channel clearance signal, and means for transmitting an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, wherein the uplink message is transmitted based at least in part on receiving the second channel clearance signal.
  • the apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory.
  • the instructions may be executable by the processor to cause the apparatus to select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, wherein the autonomous uplink mode supports unscheduled uplink transmissions, transmit a first channel clearance signal based at least in part on selecting the autonomous uplink mode, receive a second channel clearance signal from a base station in response to the first channel clearance signal, and transmit an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, wherein the uplink message is transmitted based at least in part on receiving the second channel clearance signal.
  • the non-transitory computer-readable medium may include instructions operable to select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, wherein the autonomous uplink mode supports unscheduled uplink transmissions, transmit a first channel clearance signal based at least in part on selecting the autonomous uplink mode, receive a second channel clearance signal from a base station in response to the first channel clearance signal, and transmit an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, wherein the uplink message is transmitted based at least in part on receiving the second channel clearance signal.
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for performing a successful CCA before transmitting the first channel clearance signal, wherein a format of the CCA may be based at least in part on the autonomous uplink mode and the first channel clearance signal may be transmitted based at least in part on the successful CCA.
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving, from the base station, a radio resource control (RRC) message that comprises a configuration for channel clearance signaling, wherein the first channel clearance signal may be transmitted based at least in part on receiving the configuration.
  • RRC radio resource control
  • the first channel clearance signal comprises a RTS message and the second channel clearance signal comprises a CTS message.
  • the first channel clearance signal comprises a UE identifier.
  • the second channel clearance signal comprises a frame structure indication.
  • the frame structure indication comprises a time division duplex (TDD) configuration for the autonomous uplink mode.
  • the second channel clearance signal comprises a modulation and coding scheme for the autonomous uplink mode, a transmission opportunity (TxOP) duration for the autonomous uplink mode, or hybrid automatic repeat request (HARQ) information for the autonomous uplink mode, or any combination thereof.
  • TxOP transmission opportunity
  • HARQ hybrid automatic repeat request
  • the first channel clearance signal may be transmitted and the second channel clearance signal may be received in a same transmission time interval (TTI) .
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for determining a power level for transmission of the first channel clearance signal based at least in part on a characteristic of another UE. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting the first channel clearance signal based at least in part on the determined power level.
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for determining a power level associated with the second channel clearance signal, wherein the uplink message may be transmitted according to the autonomous uplink mode based at least in part on the determined power level.
  • the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for identifying a signal strength indicator associated with a neighbor wireless node, wherein the uplink message may be transmitted according to the autonomous uplink mode based at least in part on the identified signal strength indicator.
  • the first channel clearance signal comprises a UE identifier.
  • a method of wireless communication may include selecting an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a user equipment, wherein the autonomous uplink mode supports unscheduled uplink transmissions, receiving a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode, transmitting a second channel clearance signal to the UE in response to the first channel clearance signal, and receiving an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • the apparatus may include means for selecting an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a user equipment, wherein the autonomous uplink mode supports unscheduled uplink transmissions, means for receiving a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode, means for transmitting a second channel clearance signal to the UE in response to the first channel clearance signal, and means for receiving an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • the apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory.
  • the instructions may be executable by the processor to cause the apparatus to select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a user equipment, wherein the autonomous uplink mode supports unscheduled uplink transmissions, receive a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode, transmit a second channel clearance signal to the UE in response to the first channel clearance signal, and receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • a non-transitory computer readable medium for wireless communication may include instructions executable to select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a user equipment, wherein the autonomous uplink mode supports unscheduled uplink transmissions, receive a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode, transmit a second channel clearance signal to the UE in response to the first channel clearance signal, and receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting, to the UE, a radio resource control message that comprises a configuration for channel clearance signaling, wherein the second channel clearance signal may be transmitted based at least in part on transmitting the configuration.
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for identifying one or more hidden nodes for the UE, wherein the RRC message may be transmitted based at least in part on identifying the one or more hidden nodes.
  • At least one of the one or more hidden nodes may be another UE associated with a same base station.
  • the first channel clearance signal comprises a RTS message and the second channel clearance signal comprises a CTS message.
  • the second channel clearance signal comprises a modulation and coding scheme for the autonomous uplink mode, a TxOP duration for the autonomous uplink mode, or HARQ information for the autonomous uplink mode, or any combination thereof.
  • the second channel clearance signal comprises a frame structure indication.
  • the frame structure indication comprises a TDD configuration for the autonomous uplink mode.
  • the first channel clearance signal may be received and the second channel clearance signal may be transmitted in a same TTI.
  • Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for determining a power level for transmission of the second channel clearance signal based at least in part on a characteristic of another UE. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting the second channel clearance signal based at least in part on the determined power level.
  • FIG. 1 illustrates an example of a wireless communication system that supports autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 2 illustrates an example of a wireless communication system that supports autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 3A and 3B illustrates examples of contention procedure timelines that may support autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 4 illustrates an example of a wireless communication system that supports autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 5A and 5B illustrate example aspects of wireless communication systems that support autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 6 and 7 illustrate examples of contention procedure timelines that support autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 8 illustrates an example of a process flow that supports autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIGs. 9 through 11 show block diagrams of a device or devices that support autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 12 illustrates a block diagram of a system, including a device (e.g., a user equipment (UE) ) , that supports autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • a device e.g., a user equipment (UE)
  • UE user equipment
  • FIGs. 13 through 15 show block diagrams of a device or devices that support autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • FIG. 16 illustrates a block diagram of a system, including a device (e.g., a base station) , that supports autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • a device e.g., a base station
  • FIGs. 17 through 21 illustrate methods for autonomous uplink channel clearance signaling in accordance with aspects of the present disclosure.
  • UE User equipment
  • a wireless system operating in a shared or unlicensed radio frequency spectrum band may initiate a channel clearance procedure (e.g., a request-to-send/clear-to-send (RTS/CTS) handshake) between the UE and a base station in order to resolve UE ambiguity and reduce potential collisions (e.g., from hidden nodes) .
  • a UE may perform a clear channel assessment (CCA) in attempt to access the medium.
  • CCA clear channel assessment
  • the UE may transmit a busy signal (e.g., to reserve the channel) prior to initiating channel clearance signaling, such as an RTS/CTS handshake.
  • a busy signal e.g., to reserve the channel
  • the UE may transmit a channel clearance signal (e.g., an RTS) following the busy signal, which may prompt a base station to respond with a corresponding second channel clearance signal (e.g., a CTS) .
  • the UE may then begin transmission (e.g., physical uplink shared channel (PUSCH) transmission) upon receiving the second channel clearance signal.
  • a channel clearance signal e.g., an RTS
  • PUSCH physical uplink shared channel
  • the UE may transmit a signal to indicate that it intends to occupy the shared medium; this signal may be referred to as a busy signal and may serve as the first channel clearance signal (e.g., serve the purpose of the RTS) .
  • the UE may then begin transmission upon receiving a subsequent channel clearance signal (e.g., a CTS) from the base station, which may indicate the medium is clear to send.
  • a subsequent channel clearance signal e.g., a CTS
  • a UE and base station may exchange control signaling in the channel clearance signaling.
  • base station channel clearance signaling may include a modulation and coding scheme (MCS) for an autonomous uplink mode, a transmission opportunity (TxOP) duration for an autonomous uplink mode, hybrid automatic repeat request (HARQ) information for an autonomous uplink mode, or the like.
  • UE channel clearance signaling may also include control signaling (e.g., UE identification information) . Including such control information in channel clearance signaling may reduce the need for subsequent control signaling (e.g., physical uplink control channel (PUCCH) resources) .
  • PUCCH physical uplink control channel
  • the channel clearance signaling may include preambles (e.g., Wi-Fi waveform-like signaling) , in which case timing synchronization (e.g., alignment of subframe boundaries) may already be achieved.
  • the base station and UE channel clearance signaling may be power controlled to convey additional information, and reduce intra-cell UE ambiguity. That is, channel clearance signaling (e.g., RTS, CTS) may be power controlled such that nearby UEs and base stations may identify themselves or neighbors as potential hidden nodes.
  • FIG. 1 illustrates an example of a wireless communications system 100 in accordance with various aspects of the present disclosure.
  • the wireless communications system 100 includes base stations 105, UEs 115, and a core network 130.
  • the wireless communications system 100 may be a Long Term Evolution (LTE) /LTE-Advanced (LTE-A) network.
  • LTE Long Term Evolution
  • LTE-A LTE-Advanced
  • wireless communications system 100 may be an example of a wireless local area network (WLAN) (e.g., a Wi-Fi network) or a MulteFire network.
  • WLAN wireless local area network
  • the system 100 may include an access point (AP) and multiple associated UEs 115, which may represent devices such as wireless stations, mobile stations, personal digital assistant (PDAs) , other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (e.g., TVs, computer monitors, etc. ) , printers, etc.
  • a UE 115 may also be referred to as a station (STA) , mobile station, a subscriber station, a remote unit, a wireless device, an access terminal (AT) , a handset, a user agent, a client, cellular phone, a wireless modem, a handheld device, a personal computer, a tablet, a personal electronic device, a machine type communication (MTC) device, or the like.
  • STA station
  • AT access terminal
  • MTC machine type communication
  • wireless communications system 100 When wireless communications system 100 is configured as a MulteFire network, the AP may be configured as a MulteFire eNB or base station.
  • wireless communications system 100 may include aspects of an LTE/LTE-A network, a Wi-Fi network, a MulteFire network, a neutral host small cell network, or the like, operating with overlapping coverage areas.
  • the system 100 may include an access point (AP) and multiple associated UEs 115, which may represent devices such as wireless stations, mobile stations, personal digital assistant (PDAs) , other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (e.g., TVs, computer monitors, etc. ) , printers, etc.
  • a UE 115 may also be referred to as a mobile station, a subscriber station, a remote unit, a wireless device, an access terminal (AT) , a handset, a user agent, a client, cellular phone, a wireless modem, a handheld device, a personal computer, a tablet, a personal electronic device, a machine type communication (MTC) device, or the like.
  • AP access point
  • PDAs personal digital assistant
  • a UE 115 may also be referred to as a mobile station, a subscriber station, a remote unit, a wireless device, an access terminal (AT) , a handset, a user agent, a client
  • wireless communications system 100 When wireless communications system 100 is configured as a MulteFire network, the AP may be configured as a MulteFire eNB or base station.
  • wireless communications system 100 may include aspects of an LTE/LTE-Anetwork, a Wi-Fi network, a MulteFire network, a neutral host small cell network, or the like, operating with overlapping coverage areas.
  • a MulteFire network may include access points (APs) and/or base stations 105 communicating with UEs 115 in an unlicensed radio frequency spectrum band, e.g., without a licensed frequency anchor carrier.
  • the MulteFire network may operate without an anchor carrier in the licensed spectrum.
  • Wireless communications system 100 may support autonomous uplink channel clearance signaling techniques which may, e.g., increase the efficiency of MulteFire communications within system 100.
  • Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. Each base station 105 may provide communication coverage for a respective geographic coverage area 110. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions, from a base station 105 to a UE 115. UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. Although a base station 105 may generally refer to aspects of wireless wide area networks (WWANs) and an AP may generally refer to aspects of WLANs, base station and AP may be used interchangeably. As discussed below, base stations 105 may participate in or respond to a channel clearance procedure initiated by a UE 115.
  • WWANs wireless wide area networks
  • AP may generally refer to aspects of WLANs
  • base station and AP may be used interchangeably.
  • base stations 105 may participate in or respond to a channel clearance procedure initiated by a UE
  • Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e. g, S1, etc. ) . Base stations 105 may communicate with one another over backhaul links 134 (e. g, X2, etc. ) either directly or indirectly (e. g, through core network 130) . Base stations 105 may perform radio configuration and scheduling for communication with UEs 115, or may operate under the control of a base station controller (not shown) . In some examples, base stations 105 may be macro cells, small cells, hot spots, or the like. Base stations 105 may also be referred to as eNodeBs (eNBs) 105. Base stations 105 may also be MulteFire base stations 105, which may have limited or non-ideal backhaul links 134 with other base stations 105.
  • backhaul links 132 e. g, S1, etc.
  • backhaul links 134 e. g, X
  • a UE 115, AP, or base station 105 may operate in a shared or unlicensed radio frequency spectrum band. These devices may perform a CCA prior to communicating in order to determine whether the channel is available.
  • a CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, the device may infer that a change in a received signal strength indication (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter.
  • RSSI received signal strength indication
  • the receiver can advantageously assess the RSSI from that packet.
  • the RSSI typically increases, whereas if the channel conditions become worse, the RSSI typically decreases.
  • the RSSI of the packet can be reported by the hardware in the status portion of the transmitter’s receive descriptor.
  • a CCA may also include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence.
  • a CCA procedure may be used in combination with other channel clearance procedures, including an RTS/CTS procedure, as described below.
  • UEs 115 and base stations 105 may employ a hybrid automatic repeat request (HARQ) feedback mechanism, which may be a method of ensuring that data is received correctly over a wireless communication link 125.
  • HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) .
  • FEC forward error correction
  • ARQ automatic repeat request
  • HARQ may improve throughput at the media access control (MAC) layer in poor radio conditions (e.g., signal-to-noise conditions) .
  • MAC media access control
  • Incremental Redundancy HARQ incorrectly received data may be stored in a buffer and combined with subsequent transmissions to improve the overall likelihood of successfully decoding the data.
  • redundancy bits are added to each message prior to transmission. This may be useful in poor conditions. In other cases, redundancy bits are not added to each transmission, but are retransmitted after the transmitter of the original message receives a negative acknowledgement (NACK) indicating a failed attempt to decode the information.
  • NACK negative acknowledgement
  • the chain of transmission, response and retransmission may be referred to as a HARQ process. In some cases, a limited number of HARQ processes may be used for a given communication link 125. Control signaling related to HARQ may be exchanged in channel clearance signaling, in some examples.
  • wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands.
  • wireless communications system 100 may employ LTE License Assisted Access (LTE-LAA) or LTE Unlicensed (LTE U) radio access technology in an unlicensed band such as the 5GHz Industrial, Scientific, and Medical (ISM) band.
  • LTE-LAA LTE License Assisted Access
  • LTE U LTE Unlicensed
  • the ISM band may also be used for other communications, such as MulteFire or Wi-Fi.
  • wireless devices such as base stations 105 and UEs 115 may employ LBT procedures, such as a CCA, to ensure the channel is clear before transmitting data.
  • LBT procedures such as a CCA
  • operations in unlicensed bands may be based on a carrier aggregation (CA) configuration in conjunction with component carriers (CCs) operating in a licensed band.
  • Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, or both.
  • Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD) , time division duplexing (TDD) or a combination of both.
  • FDD frequency division duplexing
  • TDD time division duplexing
  • Bidirectional communications may use FDD (e.g., using paired spectrum resources) or TDD operation (e.g., using unpaired spectrum resources) .
  • Frame structures for FDD (e.g., frame structure type 1) and TDD (e.g., frame structure type 2) may be defined.
  • each subframe may carry uplink or downlink traffic, and special subframes may be used to switch between downlink and uplink transmission.
  • Allocation of uplink and downlink subframes within radio frames may be symmetric or asymmetric and may be statically determined or may be reconfigured semi-statically.
  • Special subframes may carry downlink or uplink traffic and may include a Guard Period (GP) between downlink and uplink traffic.
  • GP Guard Period
  • Switching from uplink to downlink traffic may be achieved by setting a timing advance at the UE 115 without the use of special subframes or a guard period.
  • UL-DL configurations with switch-point periodicity equal to the frame period (e.g., 10 ms) or half of the frame period (e.g., 5 ms) may also be supported.
  • TDD frames may include one or more special frames, and the period between special frames may determine the TDD DL-to-UL switch-point periodicity for the frame.
  • Use of TDD offers flexible deployments without requiring paired UL-DL spectrum resources.
  • interference may be caused between uplink and downlink communications (e.g., interference between uplink and downlink communication from different base stations, interference between uplink and downlink communications from base stations and UEs, etc. ) .
  • a UE 115 attempting to receive and decode a downlink transmission from a serving base station 105 may experience interference from uplink transmissions from other, proximately located UEs 115.
  • a UE 115 may be detectable by a central AP, but not by other UEs 115 in the coverage area 110 of the central AP.
  • one UE 115 may be at one end of the coverage area 110 of the central AP while another UE 115 may be at the other end (e.g., a hidden node) .
  • both UEs 115 may communicate with the AP, but may not receive the transmissions of the other. This may result in colliding transmissions for the two UEs 115 in a contention-based environment (e.g., carrier sense multiple access with collision avoidance (CSMA/CA) ) because the UEs 115 may not refrain from transmitting on top of each other.
  • CSMA/CA carrier sense multiple access with collision avoidance
  • a UE 115 whose transmissions are not identifiable, but that is within the same coverage area 110 may be known as a hidden node.
  • CSMA/CA may be supplemented by the exchange of a request-to-send (RTS) packet transmitted by a sending UE 115 (or AP) and a clear-to-send (CTS) packet transmitted by the receiving UE 115 (or AP) . This may alert other devices within range of the sender and receiver not to transmit for the duration of the primary transmission.
  • RTS/CTS may help mitigate a hidden node problem.
  • a UE 115 and AP of interest may be referred to as a victim UE or victim AP when in the presence of a potentially interfering neighbor UE or AP (e.g., a hidden node) , which may be further referred to as an aggressor UE or aggressor AP.
  • a potentially interfering neighbor UE or AP e.g., a hidden node
  • intra-cell UE ambiguity and transmission collisions may result in decreased system performance (e.g., due to timing synchronization issues) .
  • Intra-cell UE ambiguity and/or transmission collisions may arise in scenarios where two or more UEs are unable to detect each other (e.g., the hidden node issue described above) .
  • a grant may be used by a base station 105 to allocate resources to UEs 115.
  • autonomous uplink e.g., grant-less uplink
  • the base station may detect the presence of the PUSCH and identify a UE through a demodulated reference signal (DMRS) or scheduling request (SR) .
  • DMRS demodulated reference signal
  • SR scheduling request
  • the base station may detect its PUSCH. However, since other intra-cell UEs may not detect the DMRS and SR from this UE, another intra-cell UE (e.g., an aggressor) may also successfully contend the medium. As a result, the base station may have a misaligned TDD configuration and frame start timing, which may result in a collision between the transmissions from the two UEs as further described below with respect to FIG. 6.
  • SFN system frame number
  • Each frame may include ten 1ms subframes numbered from 0 to 9; other frame structures may also be employed, as discussed below.
  • a subframe may be further divided into two . 5ms slots, each of which contains 6 or 7 modulation symbol periods (depending on the length of the cyclic prefix prepended to each symbol) .
  • a resource element may consist of one symbol period and one subcarrier (a 15 KHz frequency range) .
  • a resource block may contain 12 consecutive subcarriers in the frequency domain and, for a normal cyclic prefix in each orthogonal frequency division multiplexing (OFDM) symbol, 7 consecutive OFDM symbols in the time domain (1 slot) , or 84 resource elements.
  • OFDM orthogonal frequency division multiplexing
  • each symbol may contain 2048 sample periods.
  • the subframe may be the smallest scheduling unit, also known as a transmission time interval.
  • a TTI may be shorter than a subframe or may be dynamically selected (e.g., in short TTI bursts or in selected component carriers using short TTIs) .
  • a subframe may have different structures depending on the type and direction of information to be transmitted.
  • a subframe type may be an uplink subframe, a downlink subframe, or a special (S) subframe. Special subframes may facilitate a switch from downlink to uplink transmission. Further, the structure of a subframe may vary in terms of length.
  • wireless communications system 100 may be organized by transmission opportunities (TxOPs) , which may be organized according to the frame structure described above and which a may be separated by periods of time during which the wireless medium may be unavailable for devices (e.g., UEs 115 or base stations 105) within wireless communications system 100.
  • TxOPs transmission opportunities
  • a UE 115 may benefit from operating in an autonomous uplink mode or the UE 115 may benefit from operating in a grant-based uplink mode, depending on various factors within a system.
  • UE115 or a base station 105 may select an autonomous uplink mode, which may support unscheduled uplink transmissions in an unlicensed radio frequency spectrum band.
  • the UE 115 may initiate a channel clearance scheme by transmitting a first channel clearance signal (e.g., a request-to-send message) to a base station 105.
  • a first channel clearance signal e.g., a request-to-send message
  • the base station 105 may transmit a second channel clearance signal (e.g., a clear-to-send message) to the UE 115.
  • a second channel clearance signal e.g., a clear-to-send message
  • the UE 115 may transmit an uplink message in the autonomous uplink mode, confident that uplink transmissions are likely to be received by the base station 105 and unlikely to interfere with other UEs 115.
  • FIG. 2 illustrates an example of a wireless communications system 200 for autonomous uplink channel clearance signaling.
  • wireless communications system 200 may represent a system (e.g., a MulteFire system) that supports grant-based and grant-less communications coexisting in an unlicensed radio frequency spectrum band that may be shared with systems (e.g., Wi-Fi networks) employing unscheduled communications.
  • Wireless communications system 200 may include a base station 105-a in communication with UE 115-a and UE 115-b, each of which may be an example of the corresponding devices described with reference to FIG. 1.
  • UEs 115 may attempt to transmit communication 205 to base station 105.
  • both UE 115-a and UE 115-b (e.g., a neighbor UE) may attempt to transmit communication 205 to base station 105-a within a certain time range.
  • UE 115-a may be unable to detect communication 205-b transmitted by UE 115-b, which may result in a hidden node scenario.
  • Energy detection range 210 may represent a coverage area within which nearby UEs (e.g., UE 115-b) may detect a transmission from UE 115-a (e.g., communication 205-a) .
  • UEs 115 within energy detection range 210 may refrain from transmitting upon detection of communication 205-a from UE 115-a.
  • UEs 115 outside energy detection range 210 e.g., UE 115-b
  • Wireless communications system 200 may therefore employ autonomous uplink channel clearance signaling (e.g., an RTS/CTS signaling exchange or “handshake” ) between UEs 115 and base station 105-a in order to resolve the UE ambiguity and reduce the potential for collisions.
  • UEs 115 may perform a CCA in attempt to access the medium prior to proceeding with communications 205.
  • the UE 115 may transmit a busy signal (e.g., to reserve the channel) prior to initiating channel clearance signaling, such as an RTS/CTS handshake.
  • UE 115-a may subsequently transmit a channel clearance signal (e.g., an RTS) following the busy signal, which may prompt base station 105-a to respond with a corresponding second channel clearance signal (e.g., a CTS) .
  • the UE 115-a may then begin transmission of communication 205-a upon receiving the second channel clearance signal from base station 105-a, which may indicate the medium is clear to send.
  • the busy signal may serve as the first channel clearance signal (e.g., serve the purpose of the RTS) .
  • a busy signal may be modified to include channel clearance signaling.
  • the channel clearance signaling may include preambles (e.g., Wi-Fi waveform-like signaling) , in which case timing synchronization (e.g., alignment of subframe boundaries) may already be achieved.
  • the base station 105-a and UE 115-a channel clearance signaling may be power controlled to convey additional information, and reduce intra-cell UE ambiguity. That is, channel clearance signaling (e.g., RTS, CTS) may be power controlled such that nearby UEs 115 and base stations 105 may identify themselves or neighbors as potential hidden nodes.
  • channel clearance signaling e.g., RTS, CTS
  • base station 105-a may respond to a respond to channel clearance signaling from UE 115-a with power controlled channel clearance signaling (e.g., a power controlled CTS) .
  • power controlled channel clearance signaling e.g., a power controlled CTS
  • the power of the channel clearance signaling transmitted by base station 105-a may be based off an energy detection threshold, a difference in RSSI between paths of communication 205-a and communication 205-b, path loss between base station 105-a and UE 115-a, a constant factor, etc.
  • UE 115-a may proceed with communication 205-a.
  • UE 115-b may detect the power of the channel clearance signaling (e.g., the received power of the CTS) , determine the channel clearance signaling is intended for a different UE 115, and refrain from transmitting communication 205-b.
  • control signaling may also be included in the channel clearance signaling.
  • base station 105-a channel clearance signaling may include a modulation and coding scheme (MCS) for an autonomous uplink mode, a transmission opportunity (TxOP) duration for an autonomous uplink mode, hybrid automatic repeat request (HARQ) information for an autonomous uplink mode, or any combination thereof.
  • UE 115-a channel clearance signaling may also include control signaling (e.g., UE identification information) . Including such control information in channel clearance signaling may reduce the need for subsequent control signaling (e.g., physical uplink control channel (PUCCH) resources) .
  • PUCCH physical uplink control channel
  • UE channel clearance signaling may contain identification information specific to the transmitting UE 115-a (e.g., a UE identifier) .
  • aspects of communication 205 e.g., frame start timing and subframe configuration
  • may be specified by the UE 115-a e.g., via channel clearance signaling
  • may be specified by base station 105-a e.g., via RRC, channel clearance signaling, etc. .
  • FIG. 3A illustrates an example of a timeline 301 for grant-based uplink channel clearance signaling in accordance with one or more aspects of the present disclosure.
  • Timeline 301 may include UE 115-c and base station 105-b, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-2.
  • base station 105-b is in communication with UE 115-c.
  • base station 105-b may initiate a CCA procedure 305 to determine whether the channel is available for communication.
  • base station 105-b may then transmit a preamble 315, which may include a reservation signal (e.g., CTS message) to reserve the medium for uplink transmission.
  • a reservation signal e.g., CTS message
  • preamble 315 may indicate to UE 115-c that the medium is reserved for a given TxOP.
  • the TxOP includes a special subframe followed by 8 ms (i.e., 9 consecutive 1 ms subframes) , but other durations may also be employed.
  • UE 115-c may also initiate its own CCA procedure at 320, and may transmit a busy signal 325 indicating that the channel is reserved. This process may occur during switching subframe 310.
  • neighbor UEs 115 may remain silent when UE 115-c is transmitting. This occurs because neighbor UEs 115 may be within the preamble detection range of the base station 105-b.
  • Base station 105-b may send a preamble transmission (e.g., preamble 315) and an uplink grant to the UE 115-c.
  • Neighbor UEs 115 may hear the preamble and defer transmission.
  • neighbor UEs 115 may remain silent and elect not to send uplink transmission.
  • FIG. 3B illustrates an example of a timeline 302 for autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Timeline 302 may include operations of UE 115-d and base station 105-c, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-2.
  • base station 105-c may not need to initiate a CCA or transmit a preamble. As a result, there may be no need for allocating a subframe as a special subframe, as no preamble detection and decoding is performed by UE 115-d.
  • UE 115-d may initiate a CCA procedure 330 to determine whether the channel is available for communication. If it is determined that the channel is available, the UE 115-d may transmit a busy signal 335, which may be a burst of energy, indicating that the channel is reserved for communication. Based on successfully performing the CCA procedure 330, UE 115-d may initiate an uplink transmission without requiring base station 105-c to initiate its own CCA or transmit a preamble indicating that the UE 115-d has been granted access to the channel.
  • a base station 105 may result in strong interference experienced at a base station 105 in a hidden node scenario. Therefore, in some examples, techniques for channel clearance signaling may be employed to provide for more efficient communication between a base station 105 and a UE 115.
  • FIG. 4 illustrates an example of a wireless communication system 400 for autonomous uplink channel clearance signaling.
  • Wireless communication system 400 may include a base station 105-d, a UE 115-e, and a UE 115-f, which may be examples of the corresponding devices described with reference to FIGs. 1 and 2.
  • base station 105-d is capable of communicating with UE 115-e over communication link 405.
  • Base station 105-d is also configured to communicate with UE 115-f over communication link 410.
  • UE 115-f When operating in a grant-based mode, UE 115-f, a neighboring node with respect to UE 115-e, will remain silent when UE 115-e is communicating with base station 105-d. This may occur when neighbor UE 115-f is within a preamble detection range 420 of base station 105-d, and is therefore capable of receiving a preamble message transmitted by base station 105-d to UE 115-e. For example, UE 115-e and UE 115-f may each contend for access to a medium of wireless communication system 400 by sending separate request to the base station 105-d.
  • the requests may contain information related to the UE 115 (e.g., UE ID) or the data to be communicated (e.g., the data size or transmission duration based on a given MCS) .
  • the base station 105-d may grant access to UE 115-e and may send a preamble transmission and an UL grant to the UE 115-e granting access to the medium.
  • Neighbor UE 115-f may receive the preamble, determine that UE 115-e has gained access to the medium, and defer transmitting during a TxOP duration (e.g., which may be obtained by decoding the preamble) allocated to UE 115-e.
  • TxOP duration e.g., which may be obtained by decoding the preamble
  • wireless communication system 400 is operating in an autonomous uplink mode (e.g., a grant-less mode) , communication issues may arise when a neighbor UE 115-f is a hidden node.
  • a base station 105-d may be located closer to neighbor UE 115-f than UE 115-e and neighbor UE 115-f may be outside of an energy detection range 415 associated with UE 115-e.
  • UE 115-e may initiate its UL transmission over communication link 405 without receiving a grant from the base station 105-d.
  • neighbor UE 115-f may not be able to detect the transmission over communication link 405 and may therefore initiate its own UL transmission over communication link 410. Due to the reception of two messages (one from each of UEs 115-e and 115-f, over the same resources at approximately the same time) at base station 105-d, strong interference may occur at base station 105-d. Thus, to more efficiently communicate when operating according to an autonomous uplink mode, a base station 105-d may determine whether a number of hidden nodes are associated with a given UE 115. Based on the number of hidden nodes, a UE 115 and a base station 105-d may be configured to communicate according to an autonomous uplink mode and may employ additional channel clearance techniques as described herein.
  • UE 115-e may identify or measure the signal strength of neighboring nodes (e.g., UE 115-f) .
  • measurements may be taken in different ways. For example, measurements may be made through Wi-Fi beacons or DRS for a neighbor node that is an AP or a base station, respectively. Measurements may be made through STA ACK/NACK received signal strength indicator (RSSI) measurements or LTE-Direct (LTE-D) discovery signals for a neighbor node that is a STA or a UE, respectively.
  • RSSI received signal strength indicator
  • LTE-D LTE-Direct
  • measurements may be made through IEEE 802.11k measurements for a STA. Other measurement may be considered without departing from the scope of the present disclosure.
  • a UE 115-e may measure neighboring nodes based on a measurement scheme.
  • the measurement scheme may be transmitted to the UE 115-e (e.g., from base station 105-d) and may indicate to the UE 115-e what types of neighboring nodes should be measured.
  • the measurement scheme may also include information relating to the report type (e.g., triggered or periodic) when reporting the measurements back to the base station 105-d. For example, any combination of measurements made for a neighboring AP, STA, UE, or base station, may be indicated in the measurement scheme.
  • UE 115-e may identify or measure only one type of neighboring node and in other cases, the UE may identify or measure several or all types of neighboring nodes.
  • the measurement scheme may be indicated to the UE 115-e through RRC signaling, for example.
  • base station 105-d may request a measurement capability of UE 115-e using a capability check request. For instance, base station 105-d may transmit a capability check request to determine whether UE 115-e is capable of measuring one or more measurement parameters (e.g., frequency, scan type (e.g., active/passive) , scan dwell time, or RSSI threshold) .
  • the capability check request may include a request for an indication of whether UE 115-e is capable of measuring one or more signals (e.g., signals from a Wi-Fi AP or signals from a Wi-Fi STA) .
  • the request may also indicate the reporting type, such as whether UE 115-e should report measurements periodically or based on a trigger.
  • UE 115-e may determine that a neighboring node (e.g., UE 115-f) is a hidden node. For example, the measured signal strength (s) may be compared to a threshold value (i.e., an energy detection (ED) threshold or a preamble detection (PD) threshold) . In some cases, measured RSSI between various devices may be used to indicate whether a neighbor node is a hidden node. For instance, because the location or configuration of a neighboring node may affect the measured signal strength, neighbor UE 115-f may not hear UE 115-e when UE 115-e initiates an UL transmission.
  • a threshold value i.e., an energy detection (ED) threshold or a preamble detection (PD) threshold
  • ED energy detection
  • PD preamble detection
  • measured RSSI between various devices may be used to indicate whether a neighbor node is a hidden node. For instance, because the location or configuration of a neighboring node may affect the measured signal strength, neighbor
  • UE 115-e may be capable of measuring a signal strength from a neighbor UE 115-f, but may not backoff in an autonomous uplink system (e.g., due to the measured signal strength being below a threshold) . In such cases, UE 115-e may initiate its own UL transmission.
  • base station 105-d may determine to configure operations with UE 115-e according to an autonomous uplink mode.
  • UE 115-e may measure one or more nearby neighbors, such as UE 115-f.
  • UE 115-e may then transmit a hidden node indication to base station 105-d.
  • the hidden node indication may be based on, for example, the measured signal strength of one or more neighboring nodes, as discussed above.
  • the hidden node indication may also include a set of nodes that may be potential hidden nodes with respect to UE 115-e.
  • the base station 105-d may also measure nearby neighboring nodes according to the measurement scheme. This measurement may include identifying signal strength from a neighboring node. Based on these measurements and the information contained in the hidden node indication, base station 105-d may identify a number of hidden nodes associated with UE 115-e. To do so, base station 105-d may generate a set difference between the set of neighboring nodes contained in the hidden node indication and a set of neighboring nodes determined by the base station 105-d.
  • the neighboring node may be identified as a hidden node.
  • the base station 105-d may determine a number of hidden nodes associated with UE 115-e.
  • the base station 105-d may determine the number of hidden nodes associated with UE 115-e, as discussed above. If the number of nodes is below a given threshold, the base station 105-d may select an autonomous uplink mode for communication with UE 115-e. In such cases, the base station 105-d may transmit an indication of the autonomous uplink mode to UE 115-e. This indication may be transmitted in a RRC message, for example. The UE 115-e may then configure itself to operate in the autonomous uplink mode and transmit and uplink message to the base station 105-d over an unlicensed spectrum according to the autonomous uplink mode. UE 115-e may also employ channel clearance procedures to increase the efficiency of autonomous operation with respect to uplink transmissions to base station 105-d.
  • FIG. 5A and 5B illustrate examples of a measurement configuration that supports autonomous uplink mode operation in accordance with various aspects of the present disclosure.
  • Wireless communication system 501 may include UE 115-g and UE 115-h, and base station 105-e, which may be examples of or which may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-4.
  • a UE 115-g may determine whether a neighbor UE 115-h is a hidden node. This may be accomplished by determining the RSSI between various devices. For example, UE 115-g may measure the RSSI-b 510. If the measured RSSI-b 510 is less than some energy detection (ED) threshold, then neighbor UE 115-h will not backoff. That is, neighbor UE 115-h and UE 115-g may be located or configured with respect to base station 105-e as discussed in FIG. 4. If such is the case, neighbor UE 115-h may not hear UE 115-g when it initiates its uplink transmission. In such cases, neighbor UE 115-h will not backoff, but will initiate its own uplink transmission.
  • ED energy detection
  • UE 115-g may determine that measured RSSI-a 510 is less than some threshold, and that neighbor UE 115-h will not backoff. This determination may indicate that neighbor UE 115-h is a hidden node, and that the base station 105-e should engage in a grant based system, instead of an autonomous uplink mode with respect to UE 115-g.
  • RSSI-b 510 it may be difficult to measure RSSI information between a UE 115-g and a neighbor UE 115-h (e.g., RSSI-b 510) .
  • the ED threshold may depend upon the node type. For example, if the node is a UE in an LTE system, then the ED threshold may be equal to -72 dBm. In another example, if the node is a STA in a Wi-Fi system, then the ED threshold may be equal to -62 dBm.
  • base station 105-e may measure the RSSI-a 505 of the neighbor UE 115-h. If the measured RSSI-a 505 is less than some preamble detection (PD) threshold, then neighbor UE 115-h may not backoff. That is, neighbor UE 115-h and UE 115-g may be located or configured with respect to base station 105-e as discussed in FIG. 4. If such is the case, neighbor UE 115-h may be capable of receiving a grant from base station 105-e, as demonstrated by the measured RSSI 505. However, neighbor UE 115-h may not backoff in an autonomous uplink system. Thus, by measuring RSSI-a 505, base station 105-e may determine that neighbor UE 115-h is a hidden node, and that the base station 105-e may configure UEs 115 accordingly.
  • PD preamble detection
  • base station 105-e may determine a difference between RSSI-a 505, and RSSI-c 515.
  • a difference that is less than or equal to some threshold may indicate a signal-interference-noise ratio (SINR) change at base station 105-e.
  • SINR signal-interference-noise ratio
  • the value of this threshold may depend on the type of neighbor node.
  • the neighbor might be a UE, or a Wi-Fi STA. That is, UE 115-g and neighbor UE 115-h may be located or configured with respect to base station 105-e as discussed in FIG. 4.
  • the signal strength of UE 115-g is strong enough, such that neighbor UE 115-h may receive a transmission from UE 115-g and backoff.
  • the SINR degradation may become so great as to limit the ability of neighbor UE 115-h to receive a transmission from UE 115-g.
  • neighbor UE 115-h may not backoff. This determination may indicate that neighbor UE 115-h is a hidden node, and that the base station 105-e should engage in a grant based system, instead of an autonomous uplink mode with respect to UE 115-g.
  • FIG. 5A may illustrate techniques for identifying potential hidden nodes in a distributive fashion.
  • UE 115-g may complete a CCA and may subsequently transmit an RTS signal to base station 105-e on a channel of UE 115-g, which may prompt base station 105-e to transmit a CTS signal.
  • base station 105-e may determine a measure of the channel 515.
  • the measure of the channel 515 may be a path loss (PL) value.
  • the measure of the channel 515 may be an RSSI value (e.g., RSSI-c).
  • base station 105-e may broadcast a CTS with a special transmission power to allow neighboring UEs (e.g., UE 115-h) to estimate a signal strength metric for channel 515 (e.g., PL between base station 105-e and UE 115-g).
  • neighboring UEs e.g., UE 115-h
  • a signal strength metric for channel 515 e.g., PL between base station 105-e and UE 115-g.
  • the CTS transmission power may be based at least partially on an ED threshold for base station 105-e, a threshold of the difference in RSSIs between the base station 105-e and various UEs (e.g., UE 115-g and UE 115-h) that allows the base station 105-e to distinguish overlapping transmissions (e.g., “RSSI threshold”), and a signal strength metric for channel 515 (e.g., a PL) .
  • the transmission power may be computed as,
  • P CTS represents the transmitted signal power
  • ED is an energy detection threshold associated with a base station (e.g., base station 105-e)
  • Th is an RSSI threshold (e.g., an allowable difference between RSSI-c 515 and RSSI-a 505)
  • PL(S) is a pathloss along channel 515
  • C is a constant that may be required from an implementation standpoint.
  • the equation above and those that follow are exemplary; other implementations are also contemplated. Thus, the equations themselves may be modified without affecting the scope of the inventive concept.
  • the ED threshold (ED) as well as the RSSI threshold (Th) may be known by all UEs within the cell (e.g., UE 115-g, UE 115-h).
  • a potential hidden node e.g., UE 115-h
  • the received power at the neighbor UE may depend at least partly on the special transmission power and some metric associated with channel of a UE 115 (e.g., a PL or RSSI-a) , such as,
  • P NEIGHBOR is the received power (e.g., at UE 115-h) and PL(APAT) is the PL along channel of UE 115.
  • a neighbor UE may use other known information (e.g., the ED threshold, the RSSI threshold, and some metric associated with channel of a UE 115 (e.g., a PL value)) to estimate a difference between channels of a UE 115 ( ⁇ RSSI) , as
  • a neighbor UE may determine whether or not a potential hidden node scenario exists and elect to backoff or transmit accordingly. Specifically, if
  • UE 115-h would therefore decide to backoff and refrain from transmitting because the ⁇ RSSI is below some pre-specified threshold, meaning that the aggressor UE (e.g., UE 115-h) represents a hidden node for victim UE 115-g.
  • the aggressor UE e.g., UE 115-h
  • a CTS signal may be utilized to carry some control signaling information.
  • Such signaling information may include a new TDD configuration to be used by UE 115-g for autonomous uplink transmission.
  • This type of signal e.g., 3 signaling bits
  • the signaling information may contain a MCS to be used in autonomous uplink transmission.
  • the signaling information e.g., 2-3 bits
  • the signaling information may contain uplink HARQ information.
  • the payload size of the uplink HARQ information of an upcoming autonomous uplink TxOP may be reduced based on a HARQ process limitation in consecutive subframes of an autonomous uplink TxOP.
  • UE 115-g may transmit certain UE-specific information in the first subframe of a uplink TxOP and allow base station 105-e to derive this information in subsequent subframes. Incorporating this signaling information into a CTS signal may reduce PUCCH resources required for the communication session between, e.g., UE 115-g and base station 105-e.
  • wireless communication system 402 includes a UE 115-i, base station 105-f, and base station 105-g, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-4.
  • a UE 115-i may determine whether a neighbor UE 115-f is a hidden node. This may involve determining a RSSI associated with one or more devices in wireless communication system 402.
  • UE 115-i may measure the RSSI-e 525, which may include measuring a signal (e.g., a WiFi beacon or a DRS) from base station 105-g.
  • a signal e.g., a WiFi beacon or a DRS
  • the UE 115-i may then compare the measured RSSI-e 525 to a given ED threshold, which may depend upon the neighbor node type. For example, if the node is a base station in an LTE system, then the ED threshold may be equal to -72 dBm. In another example, if the node is an AP in a WiFi system, then the ED threshold may be equal to -62 dBm.
  • UE 115-i may determine that neighbor base station 105-g will not backoff from communication. That is, neighbor base station 105-g may not hear UE 115-i when it initiates a UL transmission or base station 105-g may hear the transmission from UE 115-i but may determine that because the transmission energy is below a given threshold, the base station 105-g is able to transmit on top of the transmission from UE 115-i. In such cases, because neighbor base station 105-g may not backoff, UE 115-i may determine that neighbor base station 105-g is a potential hidden node.
  • base station 105-f may measure the RSSI-d 520 of neighbor base station 105-g. If the measured RSSI-d 520 is less than a given PD threshold, base station 105-f may determine that neighbor base station 105-g may not backoff communication. That is, neighbor base station 105-g may not be capable of receiving a preamble message used to indicate reservation of a medium. For example, base station 105-f may transmit a preamble message to reserve a medium for UE 115-i. This preamble message may not be successfully heard and/or decoded by base station 105-g as the measured RSSI-d 520 may be below a given PD threshold. In such instances, neighbor base station 105-g may not backoff in an autonomous uplink system and base station 105-f may determine that neighbor base station 105-g is a hidden node.
  • base station 105-f may determine a difference between RSSI-d 520 and RSSI-f 530.
  • a difference that is less than or equal to given RSSI difference threshold may indicate a SINR change at base station 105-f.
  • the value of the SINR threshold may depend on the type of neighbor node.
  • the neighbor base station 105-g may be a base station or a WiFi AP and if the difference between RSSI-d 520 and RSSI-f 530 is above a RSSI difference threshold, it may be determined that the signal strength of UE 115-i is strong enough that neighbor base station 105-g will be able to hear a transmission from UE 115-i and backoff.
  • the SINR degradation may limit the ability of neighbor base station 105-g to hear a transmission from UE 115-i. Thus, neighbor base station 105-g may not backoff. In such cases, base station 105-f may then determine that neighbor base station 105-g is a hidden node.
  • FIG. 6 illustrates an example of a timeline 600 that supports autonomous uplink channel clearance signaling.
  • timeline 600 demonstrates a scenario associated with intra-cell UE ambiguity and potential transmission collisions of transmissions according to TDD configurations 605 in an unscheduled wireless communication system (e.g., a system employing grant-less communications) .
  • Example timeline 600 may include reference to UE 115-j and UE 115-k, which may be examples of UEs 115 described above with respect to FIG. 1.
  • TDD configuration 605-a may correspond to a transmission associated with UE 115-j while TDD configuration 605-b may correspond to a transmission associated with UE 115-k, where the timing of such transmissions are illustrated along example timeline 600.
  • the subframe formats or frame-start timings of the TDD configurations 605 may be independently configured by the UEs (e.g., UE 115-j and UE 115-k may configure TDD configuration 605-a and TDD configuration 605-b respectively) .
  • TDD configurations 605 may include a number of subframes 610 (e.g., 10 subframes in the example of FIG. 2) .
  • Subframes 610 may be configured as uplink subframes, downlink subframes, or special subframes as discussed above with reference to FIG. 1.
  • UE 115-j may successfully complete a CCA at time 615 following a contention window (not shown) . Subsequently, UE 115-j may begin transmission during uplink subframe 610-aat time 620 using, for example, PUSCH.
  • a base station 105 may detect the presence of UE 115-j based on the presence of the transmitted PUSCH. Additionally, base station 105 may identify UE 115-j through a UE-specific DMRS, which may be assigned through RRC. In another example, base station 105 may detect and identify UE 115-j through a scheduling request (SR) , which may be sent through a PUCCH.
  • SR scheduling request
  • UE 115-k e.g., a neighbor or aggressor UE 115 associated with the same base station 105 may not detect the DMRS or SR from UE 115-j, and thus may also successfully complete a CCA, for instance at time 625. Accordingly, UE 115-k may then begin transmission during subframe 610-b at time 630. As a result, configuration 605-a and configuration 605-b may be misaligned in time, which may cause base station 105 to misunderstand the TDD configuration and frame-start timing.
  • TDD configuration 605-a has a special subframe configured for subframe 610-c and TDD configuration 605-b may have an uplink subframe configured for subframe 610-c due to timing misalignment arising from UE 115-j and UE 115-k contention procedures. That is, at time 630, base station 105 may not anticipate transmissions in subframe 610-c, which may result in collisions and degraded data rates.
  • UE 115-j and UE 115-k may employ channel clearance signaling with a base station 105 for enhanced timing synchronization and alignment of subframe boundaries.
  • FIG. 7 illustrates an example of a timeline 700 that supports autonomous uplink channel clearance signaling.
  • timeline 700 may demonstrate channel clearance signaling techniques to reduce intra-cell UE ambiguity and collisions that may occur in an autonomous uplink wireless system.
  • Timeline 700 may illustrate channel clearance signaling (e.g., a RTS/CTS signaling exchange or handshake) between a UE 115-l and a base station 105-h within a TDD configuration 705.
  • UE 115-l and base station 105-h may be examples of UEs 115 and base stations 105 described above with reference to FIG. 1.
  • UE 115-l may successfully complete a CCA 715 at a time 740.
  • a TDD configuration for the uplink transmission may be specified.
  • the TDD configuration for the uplink transmission may be specified by the UE 115-l, based on the amount of data available for uplink transmission, for example.
  • the TDD configuration for the uplink transmission may be specified by the base station 105-h (e.g., through RRC) .
  • the TDD uplink configuration may include a number of subframes 710 (e.g., 12 subframes in the example of FIG. 7) .
  • Subframes 710 may be configured as uplink subframes, downlink subframes, or special subframes as discussed above with reference to FIGs. 1 and 6.
  • the initial uplink subframe 710-a of the TDD uplink configuration may be configured as a special subframe.
  • a UE 115-l may begin transmission of a busy signal 720 (e.g., at time 740) .
  • Busy signal 720 may be used to reserve the channel until UE 115-l can initiate channel clearance signaling (e.g., an RTS/CTS handshake) with base station 105-h (e.g., at time 745) .
  • channel clearance signaling e.g., an RTS/CTS handshake
  • busy signal 720 is transmitted until a first part of an initial special subframe 710-a.
  • UE 115-l may then send an RTS signal 725 at some first portion of the initial special subframe 710-a (e.g., at time 745) following the cessation of the busy signal 720.
  • Base station 105-h may receive RTS signal 725 and subsequently transmit a CTS signal 730 at some later time 750 during the initial special subframe 710-a.
  • the CTS signal 730 may be sent at a later portion (e.g., the end) of the initial special subframe 710-a.
  • the CTS signal 730 may contain control and identification information, as discussed herein.
  • UE 115-l may receive the CTS signal 730 and subsequently begin transmitting uplink data 735 at some time 755.
  • the channel clearance signals may be Wi-Fi waveforms transmitted with a Wi-Fi radio of a UE 115 or the channel clearance signals may be similar in structure to Wi-Fi waveforms, which may affect subframe boundary alignment.
  • the RTS/CTS signals correspond to Wi-Fi waveforms, they may be sent with a preamble.
  • implementation constraints may preclude a UE 115-l from sending an RTS 725 with a preamble.
  • the inclusion of a preamble in RTS 725 may, in some cases, result in undesirable overhead for the transmission.
  • some neighbor UEs (not shown) within a preamble detection (PD) threshold may be muted, which may or may not be desirable in different implementations.
  • the channel clearance signals may be sent without a preamble.
  • an RTS 725 without a preamble may effectively function as an extension of busy signal 720.
  • the RTS 725 may prevent other UEs within an energy detection (ED) threshold from attempting to access the channel.
  • the RTS 725 may contain UE 115-l identification information.
  • a CTS signal 730 sent without a preamble may reach other UEs within an ED threshold and prevent them from transmitting. These UEs may represent potential hidden nodes as discussed above with respect to FIG. 4.
  • either the RTS 725 or CTS 730 may be sent with a preamble while the other may be sent without a preamble.
  • FIG. 8 illustrates an example of a process flow 800 diagram in a system that supports autonomous uplink channel clearance signaling.
  • Process flow 800 may include UE 115-n and base station 105-j, which may be examples of UEs 115 and base stations 105 as described with reference to FIGs. 1-7. Additionally, process flow 800 may refer to an RTS signal and/or a CTS signal, which may resemble aspects of RTS signal 725 and CTS signal 730, respectively, as discussed above with reference to FIGs. 7.
  • UE 115-n may select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band (e.g., 5 MHz) at step 805.
  • the autonomous uplink mode may support unscheduled uplink transmissions (e.g., transmissions without a predicate assignment of resources) .
  • UE 115-n may, in some cases, perform a CCA at step 810.
  • the CCA may involve energy detection or preamble detection, wherein the specific format may be based at least in part on the selected autonomous uplink mode at step 805.
  • UE 115-n may transmit a first channel clearance signal (e.g., an RTS) .
  • the first channel clearance signal may be based on or configured according to a an RRC message received from base station 105-j.
  • the RRC message may contain a configuration for channel clearance signaling.
  • the first channel clearance signal may further depend on the selected autonomous uplink mode at step 805 and/or whether a successful CCA has been performed at step 810.
  • the first channel clearance signal may contain a UE identifier (e.g., to help base station 105-j distinguish UE 115-n) .
  • the transmission power level of the first channel clearance signal may be based at least in part on a characteristic of another UE (not shown) . In some cases, the characteristic of the other UE may be determined based on the CCA performed at step 810.
  • base station 105-j may transmit a second channel clearance signal (e.g., a CTS) , in response to receiving the first channel clearance signal.
  • the second channel clearance signal may contain scheduling information.
  • the second clearance signal may contain a TDD frame structure configuration for use in autonomous uplink.
  • the second channel clearance signal may contain some combination of a MCA, TxOP duration, HARQ information, or the like, for the autonomous uplink mode selected at step 805.
  • the second channel clearance signal may further be transmitted at a special power level. An example calculation is described above with reference to FIG. 5A.
  • step 815 and step 820 may occur within a time transmission interval.
  • UE 115-n may begin transmission of an uplink message (e.g., transmission of unscheduled uplink) .
  • the uplink message may be transmitted based on receiving the second channel clearance signal at step 820.
  • the uplink message may additionally be transmitted based on identifying a signal strength indicator (e.g., RSSI) associated with a neighboring wireless node (not shown) .
  • RSSI signal strength indicator
  • FIG. 9 shows a block diagram 900 of a wireless device 905 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Wireless device 905 may be an example of aspects of a user equipment (UE) 115 as described with reference to FIG. 1.
  • UE user equipment
  • Wireless device 905 may include receiver 910, UE communication manager 915, and transmitter 920.
  • Wireless device 905 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • Receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink channel clearance signaling, etc. ) . Information may be passed on to other components of the device.
  • the receiver 910 may be an example of aspects of the transceiver 1235 described with reference to FIG. 12.
  • UE communication manager 915 may be an example of aspects of the UE communication manager 1215 described with reference to FIG. 12.
  • UE communication manager 915 may select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, where the autonomous uplink mode supports unscheduled uplink transmissions, transmit, in combination with transmitter 920, a first channel clearance signal based on selecting the autonomous uplink mode, receive, in combination with receiver 910, a second channel clearance signal from a base station in response to the first channel clearance signal, and transmit, in combination with transmitter 920, an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, where the uplink message is transmitted based on receiving the second channel clearance signal.
  • Transmitter 920 may transmit signals generated by other components of the device.
  • the transmitter 920 may be collocated with a receiver 910 in a transceiver module.
  • the transmitter 920 may be an example of aspects of the transceiver 1235 described with reference to FIG. 12.
  • the transmitter 920 may include a single antenna, or it may include a set of antennas.
  • FIG. 10 shows a block diagram 1000 of a wireless device 1005 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Wireless device 1005 may be an example of aspects of a wireless device 905 or a UE 115 as described with reference to FIGs. 1 and 9.
  • Wireless device 1005 may include receiver 1010, UE communication manager 1015, and transmitter 1020.
  • Wireless device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • Receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink channel clearance signaling, etc. ) . Information may be passed on to other components of the device.
  • the receiver 1010 may be an example of aspects of the transceiver 1235 described with reference to FIG. 12.
  • UE communication manager 1015 may be an example of aspects of the UE communication manager 1215 described with reference to FIG. 12. UE communication manager 1015 may also include uplink mode component 1025, RTS component 1030, CTS component 1035, and uplink message component 1040.
  • Uplink mode component 1025 may select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, where the autonomous uplink mode supports unscheduled uplink transmissions.
  • RTS component 1030 may transmit a first channel clearance signal based on selecting the autonomous uplink mode and transmit the first channel clearance signal based on the determined power level.
  • the first channel clearance signal includes a UE identifier.
  • the first channel clearance signal is transmitted and the second channel clearance signal is received in a same transmission time interval (TTI) .
  • the first channel clearance signal includes a UE identifier.
  • the CTS component 1035 may receive a second channel clearance signal from a base station in response to the first channel clearance signal.
  • the first channel clearance signal includes a request-to-send (RTS) message and the second channel clearance signal includes a clear-to-send (CTS) message.
  • the second channel clearance signal includes a frame structure indication.
  • the frame structure indication includes a time division duplex (TDD) configuration for the autonomous uplink mode.
  • the second channel clearance signal includes a modulation and coding scheme for the autonomous uplink mode, a TxOP duration for the autonomous uplink mode, or (HARQ) information for the autonomous uplink mode, or any combination thereof.
  • Uplink message component 1040 may determine a power level associated with the second channel clearance signal, where the uplink message may be transmitted according to the autonomous uplink mode based on the determined power level, transmit an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, where the uplink message may be transmitted based on receiving the second channel clearance signal, and identify a signal strength indicator associated with a neighbor wireless node, where the uplink message may be transmitted according to the autonomous uplink mode based on the identified signal strength indicator.
  • Transmitter 1020 may transmit signals generated by other components of the device.
  • the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module.
  • the transmitter 1020 may be an example of aspects of the transceiver 1235 described with reference to FIG. 12.
  • the transmitter 1020 may include a single antenna, or it may include a set of antennas.
  • FIG. 11 shows a block diagram 1100 of a UE communication manager 1115 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the UE communication manager 1115 may be an example of aspects of a UE communication manager 915, a UE communication manager 1015, or a UE communication manager 1215 described with reference to FIGs. 9, 10, and 12.
  • the UE communication manager 1115 may include uplink mode component 1120, RTS component 1125, CTS component 1130, uplink message component 1135, clear channel assessment (CCA) component 1140, RTS/CTS configuration component 1145, and RTS power component 1150.
  • Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .
  • Uplink mode component 1120 may select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, where the autonomous uplink mode supports unscheduled uplink transmissions.
  • RTS component 1125 may transmit a first channel clearance signal based on selecting the autonomous uplink mode and transmit the first channel clearance signal based on the determined power level.
  • the first channel clearance signal includes a UE identifier.
  • the first channel clearance signal is transmitted and the second channel clearance signal is received in a same TTI.
  • the first channel clearance signal includes a UE identifier.
  • the CTS component 1130 may receive a second channel clearance signal from a base station in response to the first channel clearance signal.
  • the first channel clearance signal includes an RTS message and the second channel clearance signal includes a CTS message.
  • the second channel clearance signal includes a frame structure indication.
  • the frame structure indication may include a TDD configuration for the autonomous uplink mode.
  • the second channel clearance signal includes a modulation and coding scheme for the autonomous uplink mode, a TxOP duration for the autonomous uplink mode, or HARQ information for the autonomous uplink mode, or any combination thereof.
  • Uplink message component 1135 may determine a power level associated with the second channel clearance signal, where the uplink message may be transmitted according to the autonomous uplink mode based on the determined power level, transmit an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, where the uplink message may be transmitted based on receiving the second channel clearance signal, and identify a signal strength indicator associated with a neighbor wireless node, where the uplink message may be transmitted according to the autonomous uplink mode based on the identified signal strength indicator.
  • CCA component 1140 may perform a successful CCA before transmitting the first channel clearance signal, where a format of the CCA may be based on the autonomous uplink mode and the first channel clearance signal may be transmitted based on the successful CCA.
  • RTS/CTS configuration component 1145 may receive, from the base station, a RRC message that includes a configuration for channel clearance signaling, where the first channel clearance signal may be transmitted based on receiving the configuration.
  • RTS power component 1150 may determine a power level for transmission of the first channel clearance signal based on a characteristic of another UE.
  • FIG. 12 shows a diagram of a system 1200 including a device 1205 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Device 1205 may be an example of or include the components of wireless device 905, wireless device 1005, or a UE 115 as described above, e.g., with reference to FIGs. 1, 9 and 10.
  • Device 1205 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communication manager 1215, processor 1220, memory 1225, software 1230, transceiver 1235, antenna 1240, and I/O controller 1245. These components may be in electronic communication via one or more busses (e.g., bus 1210) .
  • Device 1205 may communicate wirelessly with one or more base stations 105.
  • Processor 1220 may include an intelligent hardware device, (e.g., a general-purpose processor, a digital signal processor (DSP) , a central processing unit (CPU) , a microcontroller, an application-specific integrated circuit (ASIC) , an field-programmable gate array (FPGA) , a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) .
  • processor 1220 may be configured to operate a memory array using a memory controller.
  • a memory controller may be integrated into processor 1220.
  • Processor 1220 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting autonomous uplink channel clearance signaling) .
  • Memory 1225 may include random access memory (RAM) and read only memory (ROM) .
  • the memory 1225 may store computer-readable, computer-executable software 1230 including instructions that, when executed, cause the processor to perform various functions described herein.
  • the memory 1225 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.
  • BIOS basic input/output system
  • Software 1230 may include code to implement aspects of the present disclosure, including code to support autonomous uplink channel clearance signaling.
  • Software 1230 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 1230 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.
  • Transceiver 1235 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above.
  • the transceiver 1235 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver.
  • the transceiver 1235 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.
  • the wireless device may include a single antenna 1240. However, in some cases the device may have more than one antenna 1240, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.
  • I/O controller 1245 may manage input and output signals for device 1205. I/O controller 1245 may also manage peripherals not integrated into device 1205. In some cases, I/O controller 1245 may represent a physical connection or port to an external peripheral. In some cases, I/O controller 1245 may utilize an operating system such as or another known operating system.
  • FIG. 13 shows a block diagram 1300 of a wireless device 1305 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Wireless device 1305 may be an example of aspects of a base station 105 as described with reference to FIG. 1.
  • Wireless device 1305 may include receiver 1310, base station communication manager 1315, and transmitter 1320.
  • Wireless device 1305 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • Receiver 1310 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink channel clearance signaling, etc. ) . Information may be passed on to other components of the device.
  • the receiver 1310 may be an example of aspects of the transceiver 1635 described with reference to FIG. 16.
  • Base station communication manager 1315 may be an example of aspects of the base station communication manager 1615 described with reference to FIG. 16.
  • Base station communication manager 1315 may select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a UE, where the autonomous uplink mode supports unscheduled uplink transmissions, receive, in combination with receiver 1310, a first channel clearance signal from the UE based on selecting the autonomous uplink mode, transmit, in combination with transmitter 1320, a second channel clearance signal to the UE in response to the first channel clearance signal, and receive, in combination with receiver 1310, an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based on receiving the second channel clearance signal.
  • Transmitter 1320 may transmit signals generated by other components of the device.
  • the transmitter 1320 may be collocated with a receiver 1310 in a transceiver module.
  • the transmitter 1320 may be an example of aspects of the transceiver 1635 described with reference to FIG. 16.
  • the transmitter 1320 may include a single antenna, or it may include a set of antennas.
  • FIG. 14 shows a block diagram 1400 of a wireless device 1405 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Wireless device 1405 may be an example of aspects of a wireless device 1305 or a base station 105 as described with reference to FIGs. 1 and 13.
  • Wireless device 1405 may include receiver 1410, base station communication manager 1415, and transmitter 1420.
  • Wireless device 1405 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • Receiver 1410 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink channel clearance signaling, etc. ) . Information may be passed on to other components of the device.
  • the receiver 1410 may be an example of aspects of the transceiver 1635 described with reference to FIG. 16.
  • Base station communication manager 1415 may be an example of aspects of the base station communication manager 1615 described with reference to FIG. 16.
  • Base station communication manager 1415 may also include uplink mode component 1425, RTS component 1430, CTS component 1435, and uplink message component 1440.
  • Uplink mode component 1425 may select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a UE, where the autonomous uplink mode supports unscheduled uplink transmissions.
  • RTS component 1430 may receive a first channel clearance signal from the UE based on selecting the autonomous uplink mode.
  • CTS component 1435 may transmit a second channel clearance signal to the UE in response to the first channel clearance signal and transmit the second channel clearance signal based on the determined power level.
  • the first channel clearance signal includes an RTS message and the second channel clearance signal includes a CTS message.
  • the second channel clearance signal includes a modulation and coding scheme for the autonomous uplink mode, a TxOP duration for the autonomous uplink mode, or HARQ information for the autonomous uplink mode, or any combination thereof.
  • the second channel clearance signal includes a frame structure indication.
  • the frame structure indication may include a TDD configuration for the autonomous uplink mode.
  • the first channel clearance signal is received and the second channel clearance signal is transmitted in a same TTI.
  • Uplink message component 1440 may receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based on receiving the second channel clearance signal.
  • Transmitter 1420 may transmit signals generated by other components of the device.
  • the transmitter 1420 may be collocated with a receiver 1410 in a transceiver module.
  • the transmitter 1420 may be an example of aspects of the transceiver 1635 described with reference to FIG. 16.
  • the transmitter 1420 may include a single antenna, or it may include a set of antennas.
  • FIG. 15 shows a block diagram 1500 of a base station communication manager 1515 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the base station communication manager 1515 may be an example of aspects of a base station communication manager 1615 described with reference to FIGs. 13, 14, and 16.
  • the base station communication manager 1515 may include uplink mode component 1520, RTS component 1525, CTS component 1530, uplink message component 1535, RRC component 1540, node identification component 1545, and CTS power component 1550. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .
  • Uplink mode component 1520 may select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a UE, where the autonomous uplink mode supports unscheduled uplink transmissions.
  • RTS component 1525 may receive a first channel clearance signal from the UE based on selecting the autonomous uplink mode.
  • CTS component 1530 may transmit a second channel clearance signal to the UE in response to the first channel clearance signal and transmit the second channel clearance signal based on the determined power level.
  • the first channel clearance signal includes a request-to-send (RTS) message and the second channel clearance signal includes a clear-to-send (CTS) message.
  • the second channel clearance signal includes a modulation and coding scheme for the autonomous uplink mode, a TxOP duration for the autonomous uplink mode, or HARQ information for the autonomous uplink mode, or any combination thereof.
  • the second channel clearance signal includes a frame structure indication.
  • the frame structure indication may include a TDD configuration for the autonomous uplink mode.
  • the first channel clearance signal is received and the second channel clearance signal is transmitted in a same TTI.
  • Uplink message component 1535 may receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based on receiving the second channel clearance signal.
  • RRC component 1540 may transmit, to the UE, a RRC message that includes a configuration for channel clearance signaling, where the second channel clearance signal may be transmitted based on transmitting the configuration.
  • Node identification component 1545 may identify one or more hidden nodes for the UE, where the RRC message may be transmitted based on identifying the one or more hidden nodes. In some cases, at least one of the one or more hidden nodes is another UE associated with a same base station. CTS power component 1550 may determine a power level for transmission of the second channel clearance signal based on a characteristic of another UE.
  • FIG. 16 shows a diagram of a system 1600 including a device 1605 that supports autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • Device 1605 may be an example of or include the components of base station 105 as described above, e.g., with reference to FIG. 1.
  • Device 1605 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communication manager 1615, processor 1620, memory 1625, software 1630, transceiver 1635, antenna 1640, network communications manager 1645, and base station communications manager 1650. These components may be in electronic communication via one or more busses (e.g., bus 1610) .
  • Device 1605 may communicate wirelessly with one or more UEs 115.
  • Processor 1620 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) .
  • processor 1620 may be configured to operate a memory array using a memory controller.
  • a memory controller may be integrated into processor 1620.
  • Processor 1620 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting autonomous uplink channel clearance signaling) .
  • Memory 1625 may include RAM and ROM.
  • the memory 1625 may store computer-readable, computer-executable software 1630 including instructions that, when executed, cause the processor to perform various functions described herein.
  • the memory 1625 may contain, among other things, a BIOS which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.
  • Software 1630 may include code to implement aspects of the present disclosure, including code to support autonomous uplink channel clearance signaling.
  • Software 1630 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 1630 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.
  • Transceiver 1635 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above.
  • the transceiver 1635 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver.
  • the transceiver 1635 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.
  • the wireless device may include a single antenna 1640. However, in some cases the device may have more than one antenna 1640, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.
  • Network communications manager 1645 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1645 may manage the transfer of data communications for client devices, such as one or more UEs 115.
  • Base station communications manager 1650 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the base station communications manager 1650 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, base station communications manager 1650 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.
  • FIG. 17 shows a flowchart illustrating a method 1700 for autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the operations of method 1700 may be implemented by a UE 115 or its components as described herein.
  • the operations of method 1700 may be performed by a UE communication manager as described with reference to FIGs. 9 through 12.
  • a UE 115 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects the functions described below using special-purpose hardware.
  • the UE 115 may select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, wherein the autonomous uplink mode supports unscheduled uplink transmissions.
  • the operations of block 1705 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1705 may be performed by a uplink mode component as described with reference to FIGs. 9 through 12.
  • the UE 115 may transmit a first channel clearance signal based at least in part on selecting the autonomous uplink mode.
  • the operations of block 1710 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1710 may be performed by a RTS component as described with reference to FIGs. 9 through 12.
  • the UE 115 may receive a second channel clearance signal from a base station in response to the first channel clearance signal.
  • the operations of block 1715 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1715 may be performed by a CTS component as described with reference to FIGs. 9 through 12.
  • the UE 115 may transmit an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, wherein the uplink message may be transmitted based at least in part on receiving the second channel clearance signal.
  • the operations of block 1720 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1720 may be performed by a uplink message component as described with reference to FIGs. 9 through 12.
  • FIG. 18 shows a flowchart illustrating a method 1800 for autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the operations of method 1800 may be implemented by a UE 115 or its components as described herein.
  • the operations of method 1800 may be performed by a UE communication manager as described with reference to FIGs. 9 through 12.
  • a UE 115 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects the functions described below using special-purpose hardware.
  • the UE 115 may select an autonomous uplink mode for transmission in an unlicensed radio frequency spectrum band, wherein the autonomous uplink mode supports unscheduled uplink transmissions.
  • the operations of block 1805 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1805 may be performed by a uplink mode component as described with reference to FIGs. 9 through 12.
  • the UE 115 may perform a successful CCA before transmitting the first channel clearance signal, wherein a format of the CCA may be based at least in part on the autonomous uplink mode and the first channel clearance signal may be transmitted based at least in part on the successful CCA.
  • the operations of block 1810 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1810 may be performed by a CCA component as described with reference to FIGs. 9 through 12.
  • the UE 115 may transmit a first channel clearance signal based at least in part on selecting the autonomous uplink mode.
  • the operations of block 1815 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1815 may be performed by a RTS component as described with reference to FIGs. 9 through 12.
  • the UE 115 may receive a second channel clearance signal from a base station in response to the first channel clearance signal.
  • the operations of block 1820 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1820 may be performed by a CTS component as described with reference to FIGs. 9 through 12.
  • the UE 115 may determine a power level associated with the second channel clearance signal, wherein the uplink message may be transmitted according to the autonomous uplink mode based at least in part on the determined power level.
  • the operations of block 1825 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1825 may be performed by a uplink message component as described with reference to FIGs. 9 through 12.
  • the UE 115 may transmit an uplink message in the unlicensed radio frequency spectrum band according to the autonomous uplink mode, wherein the uplink message may be transmitted based at least in part on receiving the second channel clearance signal.
  • the operations of block 1830 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1830 may be performed by a uplink message component as described with reference to FIGs. 9 through 12.
  • FIG. 19 shows a flowchart illustrating a method 1900 for autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the operations of method 1900 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 1900 may be performed by a base station communication manager as described with reference to FIGs. 13 through 16.
  • a base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may perform aspects the functions described below using special-purpose hardware.
  • the base station 105 may select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a UE, wherein the autonomous uplink mode supports unscheduled uplink transmissions.
  • the operations of block 1905 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1905 may be performed by a uplink mode component as described with reference to FIGs. 13 through 16.
  • the base station 105 may receive a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode.
  • the operations of block 1910 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1910 may be performed by a RTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may transmit a second channel clearance signal to the UE in response to the first channel clearance signal.
  • the operations of block 1915 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1915 may be performed by a CTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • the operations of block 1920 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 1920 may be performed by a uplink message component as described with reference to FIGs. 13 through 16.
  • FIG. 20 shows a flowchart illustrating a method 2000 for autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the operations of method 2000 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 2000 may be performed by a base station communication manager as described with reference to FIGs. 13 through 16.
  • a base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may perform aspects the functions described below using special-purpose hardware.
  • the base station 105 may select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a UE, wherein the autonomous uplink mode supports unscheduled uplink transmissions.
  • the operations of block 2005 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2005 may be performed by a uplink mode component as described with reference to FIGs. 13 through 16.
  • the base station 105 may identify one or more hidden nodes for the UE, wherein the RRC message may be transmitted based at least in part on identifying the one or more hidden nodes.
  • the operations of block 2010 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2010 may be performed by a node identification component as described with reference to FIGs. 13 through 16.
  • the base station 105 may transmit, to the UE, an RRC message that comprises a configuration for channel clearance signaling, wherein the second channel clearance signal may be transmitted based at least in part on transmitting the configuration.
  • the operations of block 2015 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2015 may be performed by a RRC component as described with reference to FIGs. 13 through 16.
  • the base station 105 may receive a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode.
  • the operations of block 2020 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2020 may be performed by a RTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may transmit a second channel clearance signal to the UE in response to the first channel clearance signal.
  • the operations of block 2025 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2025 may be performed by a CTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • the operations of block 2030 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2030 may be performed by a uplink message component as described with reference to FIGs. 13 through 16.
  • FIG. 21 shows a flowchart illustrating a method 2100 for autonomous uplink channel clearance signaling in accordance with various aspects of the present disclosure.
  • the operations of method 2100 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 2100 may be performed by a base station communication manager as described with reference to FIGs. 13 through 16.
  • a base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may perform aspects the functions described below using special-purpose hardware.
  • the base station 105 may transmit the second channel clearance signal based at least in part on the determined power level.
  • the operations of block 2105 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2105 may be performed by a CTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may select an autonomous uplink mode for communication in an unlicensed radio frequency spectrum band with a UE, wherein the autonomous uplink mode supports unscheduled uplink transmissions.
  • the operations of block 2110 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2110 may be performed by a uplink mode component as described with reference to FIGs. 13 through 16.
  • the base station 105 may receive a first channel clearance signal from the UE based at least in part on selecting the autonomous uplink mode.
  • the operations of block 2115 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2115 may be performed by a RTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may determine a power level for transmission of the second channel clearance signal based at least in part on a characteristic of another UE.
  • the operations of block 2120 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2120 may be performed by a CTS power component as described with reference to FIGs. 13 through 16.
  • the base station 105 may transmit a second channel clearance signal to the UE in response to the first channel clearance signal.
  • the operations of block 2125 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2125 may be performed by a CTS component as described with reference to FIGs. 13 through 16.
  • the base station 105 may receive an uplink message from the UE in the unlicensed radio frequency spectrum band according to the autonomous uplink mode and based at least in part on receiving the second channel clearance signal.
  • the operations of block 2130 may be performed according to the methods described with reference to FIGs. 1 through 8. In certain examples, aspects of the operations of block 2130 may be performed by a uplink message component as described with reference to FIGs. 13 through 16.
  • a CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc.
  • CDMA2000 covers IS-2000, IS-95, and IS-856 standards.
  • IS-2000 Releases may be commonly referred to as CDMA2000 1X, 1X, etc.
  • IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc.
  • UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA.
  • a TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) .
  • GSM Global System for Mobile Communications
  • An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc.
  • UMB Ultra Mobile Broadband
  • E-UTRA Evolved UTRA
  • IEEE Institute of Electrical and Electronics Engineers
  • Wi-Fi Institute of Electrical and Electronics Engineers
  • WiMAX IEEE 802.16
  • IEEE 802.20 Flash-OFDM
  • UTRA and E-UTRA are part of Universal Mobile Telecommunications system (UMTS) .
  • 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of Universal Mobile Telecommunications System (UMTS) that use E-UTRA.
  • UTRA, E-UTRA, UMTS, LTE, LTE-A, and Global System for Mobile communications are described in documents from the organization named “3rd Generation Partnership Project” (3GPP) .
  • CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) .
  • the techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. While aspects an LTE system may be described for purposes of example, and LTE terminology may be used in much of the description, the techniques described herein are applicable beyond LTE applications.
  • the term eNB may be generally used to describe the base stations.
  • the wireless communications system or systems described herein may include a heterogeneous LTE/LTE-A network in which different types of eNBs provide coverage for various geographical regions.
  • each eNB or base station may provide communication coverage for a macro cell, a small cell, or other types of cell.
  • the term “cell” may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc. ) of a carrier or base station, depending on context.
  • Base stations may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, eNodeB, Home NodeB, a Home eNodeB, or some other suitable terminology.
  • the geographic coverage area for a base station may be divided into sectors making up only a portion of the coverage area.
  • the wireless communications system or systems described herein may include base stations of different types (e.g., macro or small cell base stations) .
  • the UEs described herein may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like. There may be overlapping geographic coverage areas for different technologies.
  • a macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider.
  • a small cell is a lower-powered base station, as compared with a macro cell, that may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells.
  • Small cells may include pico cells, femto cells, and micro cells according to various examples.
  • a pico cell for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider.
  • a femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) .
  • An eNB for a macro cell may be referred to as a macro eNB.
  • An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB.
  • An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers) .
  • a UE may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like.
  • the wireless communications system or systems described herein may support synchronous or asynchronous operation.
  • the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time.
  • the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time.
  • the techniques described herein may be used for either synchronous or asynchronous operations.
  • Each communication link described herein including, for example, wireless communications system 100 and 200 of FIGs. 1 and 2—may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies) .
  • Information and signals described herein may be represented using any of a variety of different technologies and techniques.
  • data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
  • a general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
  • a processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .
  • the functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
  • Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
  • a non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer.
  • non-transitory computer-readable media may comprise RAM, ROM, electrically erasable programmable read only memory (EEPROM) , compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.
  • RAM random access memory
  • ROM read only memory
  • EEPROM electrically erasable programmable read only memory
  • CD compact disk
  • magnetic disk storage or other magnetic storage devices or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or
  • any connection is properly termed a computer-readable medium.
  • the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave
  • the coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.
  • Disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

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Abstract

L'invention concerne des procédés, des systèmes et des dispositifs de communication sans fil. Un équipement d'utilisateur (UE) ou une station de base peut sélectionner un mode de liaison montante autonome, qui peut prendre en charge des transmissions de liaison montante non planifiées dans une bande de spectre de radiofréquences sans licence. Un UE peut initier un schéma d'autorisation de canal en transmettant un premier signal d'autorisation de canal (par exemple, un message de requête à envoyer), qui peut comprendre un identifiant d'UE, à une station de base, avant de transmettre un message de liaison montante dans la bande de spectre de radiofréquences sans licence. En réponse, la station de base peut transmettre un second signal d'autorisation de canal (par exemple, un message prêt à envoyer) à l'UE qui, dans certains cas, peut comprendre des informations de commande. Dans certains exemples, le second signal d'autorisation de canal peut être transmis à un niveau de puissance qui est basé sur une caractéristique de l'UE. Après réception du second signal d'autorisation de canal, l'UE peut transmettre un message de liaison montante dans le mode de liaison montante autonome.
PCT/CN2016/101243 2016-09-30 2016-09-30 Signalisation d'autorisation de canal de liaison montante autonome multefire WO2018058597A1 (fr)

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Application Number Priority Date Filing Date Title
PCT/CN2016/101243 WO2018058597A1 (fr) 2016-09-30 2016-09-30 Signalisation d'autorisation de canal de liaison montante autonome multefire
PCT/CN2017/102865 WO2018059311A1 (fr) 2016-09-30 2017-09-22 Signalisation de dégagement de canal de liaison montante autonome multefire
CN201780060045.XA CN109792753B (zh) 2016-09-30 2017-09-22 Multefire自主上行链路信道清除信令
EP17854761.8A EP3520527B1 (fr) 2016-09-30 2017-09-22 Signalisation de dégagement de canal de liaison montante autonome multefire
US16/326,290 US11576206B2 (en) 2016-09-30 2017-09-22 Multefire autonomous uplink channel clearance signaling

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PCT/CN2016/101243 WO2018058597A1 (fr) 2016-09-30 2016-09-30 Signalisation d'autorisation de canal de liaison montante autonome multefire

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WO2020068392A1 (fr) * 2018-09-27 2020-04-02 Qualcomm Incorporated Accès à la nouvelle radio multicanal sans licence pour équipement d'utilisateur à capacité de basse radiofréquence

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US20160128024A1 (en) * 2014-10-29 2016-05-05 Qualcomm Incorporated Methods and apparatus for multiple user uplink access
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WO2020068392A1 (fr) * 2018-09-27 2020-04-02 Qualcomm Incorporated Accès à la nouvelle radio multicanal sans licence pour équipement d'utilisateur à capacité de basse radiofréquence
EP3858072A1 (fr) * 2018-09-27 2021-08-04 QUALCOMM Incorporated Accès à la nouvelle radio multicanal sans licence pour équipement d'utilisateur à capacité de basse radiofréquence
US11751242B2 (en) 2018-09-27 2023-09-05 Qualcomm Incorporated Radio-unlicensed multi-channel access for low-radio frequency-capable user equipment

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