CN108781463A - Low latency PRACH designs in unlicensed spectrum - Google Patents

Abstract

The method for the low latency PRACH designs in unlicensed spectrum is generally described herein.The exemplary means of user equipment (UE) include：Memory；And processing circuit, processing circuit are used for：Listem-before-talk (LBT) process is executed on one or more channels of unlicensed spectrum.Processing circuit is additionally operable to：In response to clear channel assessment (CCA) (CCA), the associated with low latency random access (RA) process first first message sent is encoded in unlicensed spectrum.First message includes Physical Random Access Channel (PRACH) lead code and message part.Message part includes Cell Radio Network Temporary Identity symbol (C-RNTI), buffer status reporting (BSR) information, at least one of the mark of the ability of UE, and/or UE.Processing circuit is additionally operable to：Uplink (UL) is received in response to the first step based on low latency RA processes to authorize, coding UL data are for transmission.

Description

Low-Latency PRACH Design in Unlicensed Spectrum

priority statement

This patent application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 62/307,202, filed March 11, 2016, and U.S. Provisional Patent Application Serial No. 62/302,398, filed March 2, 2016, They are hereby incorporated by reference in their entirety.

technical field

Embodiments relate to cellular networks. Some embodiments relate to carrier aggregation in 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) and LTE Advanced (LTE-A) networks as well as 4th Generation (4G) and 5th Generation (5G) networks.

Background technique

Enhancements to LTE in 3GPP Release 13 are used to enable operation in unlicensed spectrum through License Assisted Access (LAA), which extends system bandwidth by utilizing a flexible carrier aggregation (CA) framework. Potential LTE operation in unlicensed spectrum may include LTE operation in unlicensed spectrum via dual connectivity (DC), or a standalone LTE system (eg, MuLTEfire) in unlicensed spectrum.

Description of drawings

Figure 1 illustrates a wireless telecommunications network 100 for performing low-latency RA procedures according to some embodiments of the present disclosure.

FIG. 2 shows a block diagram of components of a user equipment (UE) device 1000 according to an embodiment of the disclosure.

Figure 3 illustrates a signal diagram for a low-latency two-step RA procedure according to some embodiments of the present disclosure.

FIG. 4A illustrates a signal diagram for a failed low-latency single-step RA procedure, according to some embodiments of the present disclosure.

Figure 4B shows a signal diagram for a successful low-latency single-step RA procedure, according to some embodiments of the present disclosure.

FIG. 5 shows a flowchart of a method for performing a low-latency RA procedure according to some embodiments of the present disclosure.

FIG. 6 shows a flowchart of a method for performing a low-latency RA procedure according to some embodiments of the present disclosure.

FIG. 7 shows a flowchart of a method for performing a low-latency RA procedure according to some embodiments of the present disclosure.

Figure 8 shows a block diagram of a machine, exemplified by a computer system, according to some embodiments of the present disclosure.

Detailed ways

The following description and drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may have structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

Embodiments provide systems and methods for low-latency Physical Random Access Channel (PRACH) signaling in unlicensed spectrum via License Assisted Access (LAA) or MulteFire. The PRACH may be used for scheduling requests (SRs), uplink (UL) synchronization, and power control for initial UL transmissions. In general, SR may include a four-step contention-based random access procedure that includes: the UE provides a PRACH preamble signal; the eNodeB responds with a Random Access Request (RAR) signal; the UE A Message 3 signal with a Cell Radio Network Temporary Identifier (C-RNTI) or Temporary C-RNTI is provided; and the eNodeB responds with a contention resolution message (eg, Message 4). When operating in unlicensed spectrum, the radio transmitter's RA procedure can be complicated by the listen-before-talk (LBT) protocol, in which the radio transmitter first senses the medium and only The process of sending when the medium is detected to be free is also called Clear Channel Assessment (CCA). CCA utilizes at least energy detection (ED) to determine the presence of a signal on the channel. With LBT employed, both the UE and the eNodeB may perform the LBT procedure before sending their respective messages associated with the RACH, which may add significant delay to the random access procedure and may limit UL transmissions.

Figure 1 illustrates a wireless telecommunications network 100 for performing low-latency random access (RA) procedures, according to some embodiments of the present disclosure. In some embodiments, the wireless telecommunications network 100 may implement a 3rd Generation Partnership Project (3GPP) fifth generation (5G) wireless network or a 3rd Generation Partnership Project (3GPP) Long Term Evolution Advanced (LTE-A) wireless network.

The illustrative telecommunications network includes an evolved Node B (eNodeB) 120 operable over a respective coverage area or cell 122 and a UE 104 within the coverage area of the cell 122 . The telecommunications network 100 may include more eNodeBs and/or UEs. The coverage area 122 of the eNodeB 120 may be further divided into three sectors. In some examples, each sector of eNodeB 120 may also be considered a cell.

UE 170 may provide transmissions to and receive transmissions from eNodeB 120 in licensed spectrum, unlicensed spectrum, or a combination thereof. Operation in licensed and unlicensed spectrum may include dual connectivity (DC). Only operations in the unlicensed spectrum can use MuLTEfire. In some examples, operation in unlicensed spectrum can be via LAA, which can expand available bandwidth by utilizing a flexible carrier aggregation (CA) framework. To ensure coexistence with incumbent systems and other LAA/MuLTEfire systems, transmissions in unlicensed spectrum may include performing LBT procedures, and reserving transmissions until CCA is complete and the channel is sensed to be free.

In operation, wireless telecommunications network 100 may include the capability for eNodeB 120 and UE 104 to communicate over an unlicensed spectrum. To provide UL data to eNodeB 120, UE 104 may initiate an SR including PRACH signaling. In addition to SR, PRACH signals may be used for uplink (UL) synchronization and power control for initial UL transmissions. Due to the implementation of LBT, the RA procedure may experience large delays and may limit UL transmissions.

In one embodiment that supports low-latency RA procedures in unlicensed spectrum, UE 104 and eNodeB 120 may support low-latency two-step RA procedures (eg, in addition to LBT procedures). In a first step of the low-latency two-step RA procedure, UE 104 may provide a first transmission on the allocated PRACH resources in response to the CCA indicating that the channel is idle (eg, according to the LBT procedure). In one example, the first transmission may include a PRACH preamble and a message portion including a (e.g., temporary or assigned) C-RNTI, buffer status report (BSR) information, UE 104 capabilities, and message 3. The message 3 may include the identity of the UE 104 . In some examples, the message portion may also include a Common Control Channel (CCCH) subheader. The message part may include a Medium Access Control (MAC) part and a Radio Resource Control (RRC) part. The MAC part includes possible C-RNTI, BRS information, and Layer 1 (L1)/MAC UE capabilities. The RRC part includes RRC message identified with the addressed UE. Alternatively, the UE identity can be included in the MAC part.

In response to receiving the first transmission, eNodeB 120 may provide a second transmission including RAR and/or Message 4, the second transmission using the physical downlink control channel (PDCCH) or evolved PDCCH (ePDCCH) used in the first transmission scheduled by one of the C-RNTI received from the UE 104, or a common random access RNTI (RA-RNTI) calculated based on the time-frequency resource used by the first transmitted preamble.

The C-RNTI or RA-RNTI included in the second transmission may be based on eNodeB 120 contention resolution results. Contention resolution may be performed based on one of the PDCCH/ePDCCH, or either the MAC part or the RRC part (eg, whichever was provided by the UE 104 in the first transmission). In the PDCCH/ePDCCH based case, contention resolution may be considered successful if the PDCCH/ePDCCH includes the UE's allocated C-RNTI. In the case based on the MAC part, contention resolution may be considered successful if the MAC part includes the UE 104's assigned C-RNTI, or UE 104 identity provided in the first transmission. In the RRC part based case, contention resolution may be considered successful if the RRC message of the RRC part provided in the first transmission includes the UE 104 identity provided in the first transmission.

The UL grant assignment may be included in the message part of the RAR, the PDCCH/ePDCCH with the assigned C-RNTI of the UE 104, or the PDCCH/ePDCCH with the assigned RA-RNTI. If included in the PDCCH/ePDCCH with the assigned C-RNTI of the UE 104, the UE 104 can decode the downlink (DL ) Control Information (DCI) and UL Authorization. If included in the PDCCH/ePDCCH with RA-RNTI, the UE 104 can decode the DL grant for scheduling RAR/Message 4 and the UL grant for scheduling PUSCH masked with the assigned RA-RNTI.

In another embodiment that supports low-latency RA procedures in unlicensed spectrum, UE 104 and eNodeB 120 may support low-latency one-step RA procedures (eg, in addition to LBT procedures). In a first step of the low-delay one-step RA procedure, the UE 104 may provide a first transmission on the allocated PRACH resources in response to the CCA indicating that the channel is idle (eg, according to the LBT procedure). The first transmission may include a PRACH preamble and a message portion including (e.g., temporary or assigned) C-RNTI, BSR information, CCCH subheader, and/or Message 3, which may include UE 104 The identity of the (for example, can be used for contention resolution). The message part may include a Medium Access Control (MAC) part and an RRC part, the MAC part includes C-RNTI, BRS information, CCCH subheader, Layer 1 (L1)/MAC UE capability, and the RRC part includes a UE with contention resolution The identified RRC message. Alternatively, UE identity for contention resolution can be included in the MAC part. The first transmission may use a Physical Uplink Control Channel (PUCCH) waveform, where a first portion (eg, n symbols) may be used for the PRACH preamble and the remaining portion (eg, the remaining m symbols) may be used for the message portion. The duration of the low-latency PUCCH (sPUCCH) can be up to 4 symbols. The sPUCCH may have an interlace structure with 10 physical resource blocks (PRBs)/interlace in a 20 MHz system. A UE 104 may be assigned one or more interlaces for UL transmission.

If the UL grant is received within a predetermined amount of time (e.g., within k subframes, or before the MAC contention resolution timer for the C-RNTI (indicating successful contention resolution) has expired), the UE 104 may Send UL data normally. The UL grant may be included in a message scheduled via the PDCCH/ePDCCH with the C-RNTI received from the UE 104 for the UL grant. Otherwise, UE 104 may send another first transmission with the new random preamble index at the configured PRACH subframe. The time window of k subframes may be counted in terms of absolute time (eg, Key Management Service (KMS) time) or in terms of valid DL subframes (eg, subframes with DL transmission).

For the first transmission of UE 104 in the two-step RA procedure or the one-step RA procedure, the first N symbols may be used to send the PRACH preamble. The PRACH preamble can also be used for channel estimation after detection. The remaining M symbols can be used for data transmission (eg, C-RNTI, BSR information, CCCH subheader, message 3, etc.). For example, when the first step of PRACH transmission is performed on sPUCCH resources, N and M may be equal to 2, which are the last 4 SC-FDMA symbols of the special subframe. If one interlace is allocated for the first transmission, in a 20MHz system, 20 PRBs are available for data transmission over 2 symbols. With quadrature phase shift keying (QPSK) modulation, each interleave can carry up to 480 bits. In one example, the required payload size for initial access and BSR is 56 bits with an additional 24 cyclic redundancy check (CRC) bits. In the case of a code rate of 1/3, the number of coded bits can be 240, which is much smaller than 480 bits. If the payload size increases beyond 480 bits, additional interlaces can be allocated to the UE 104, or the code rate can be reduced to allow higher density transmissions.

When the PRACH preamble requires four symbols on the PUCCH resource, the Physical Uplink Shared Channel (PUSCH) subframe following the PUCCH resource can be used to carry the message part of the first transmission (e.g., C-RNTI, BSR information, CCCH subheader, and message 3). One or more interlaces of the PUSCH subframe may be allocated for the first transmission, and multiple UEs may be multiplexed in the frequency and/or code domain. In order to reduce the probability of collision, fewer users can be allocated to transmit through the PUSCH subframe. The PRACH preamble sequence can be used for channel estimation. The same structure as conventional PUSCH transmission can be used, where demodulation reference signal (DMRS) symbols can be used for channel estimation. If the first transmitted message part (e.g., C-RNTI, BSR information, message 3, and CCCH subheader) transmitted simultaneously on the allocated PRACH resource cannot be correctly detected, but the PRACH preamble sequence is correctly detected , then the two-step/one-step PRACH can fall back to the traditional RA process.

In systems where eNodeB 120 and UE 104 support more than one RA procedure (e.g., a combination of traditional RA procedures, two-step RA procedures, and one-step RA procedures), eNodeB 120 and/or UE 104 may indicate which RA procedures they support or intend to use method. In a UE-specific example, eNodeB 120 may indicate to UE 104 which RA procedure to use when UE 104 is in RRC connected mode.

In a cell-specific procedure, the eNodeB 120 may indicate (eg, via RRC signaling) which of the traditional RA procedures, two-step RA procedures, and/or one-step RA procedures it supports, and the UE 104 may determine to Which RA process to use. One example of a method by UE 104 to indicate the selected RA procedure to eNodeB 120 may include using a PRACH preamble signature associated with the selected RA procedure. For example, eNodeB 120 may specify a specific set of preamble signatures for each supported RA procedure. UE 104 can use the preamble signal of a set of preamble signatures associated with the selected RA procedure, and eNodeB 120 can detect the selected RA procedure by detecting the preamble signature.

Another example of a method by UE 104 to indicate the selected RA procedure to eNodeB 120 may include using specific resources (eg, time or frequency subcarriers) associated with the selected RA procedure. For example, eNodeB 120 may designate a specific set of resources for each supported RA procedure. UE 104 may use resources from the set of resources associated with the selected RA procedure, and eNodeB 120 may detect the selected RA procedure through the resource on which message 1 was sent.

The eNodeB 120 may provide an indication of the selected RA procedure to the UE 104 in a master information block (MIB). The eNodeB 120 may set the PRACH indication in the MIB to a specific value associated with the selected or supported RA procedure. In one example, the eNodeB 120 may set one or more reserved bits in the payload of the MIB block, or one or more additional bits in the payload of the updated MIB block, to the specific RA procedure associated with the selected RA procedure. value to indicate the selected RA process.

Another example of a method by which eNodeB 120 provides UE 104 with an indication of the selected or supported RA procedures may be indicated in a system information block (SIB) or extended SIB (eSIB). The eNodeB 120 may set the selected RA procedure indication in the SIB/eSIB to a specific value associated with the selected RA procedure, and the UE 104 may detect the selected RA procedure indication based on the selected RA procedure indication in the SIB/eSIB RA process. In one example, the PRACH configuration index parameter of SIB2/eSIB2 may be extended to include support for one or both of a two-step RA procedure and a one-step RA procedure. The eNodeB 120 may indicate the selected RA process by setting the extended PRACH configuration index parameter in SIB2/eSIB2 to a specific value associated with the selected RA process. In another example, new parameters may be added to the SIB/eSIB (eg, in the PRACH configuration field of SIB2/eSIB2) for one or both of the two-step RA procedure and the one-step RA procedure. The eNodeB 120 may indicate the selected RA process by setting parameters associated with the selected RA process in the PRACH configuration field of SIB2/eSIB2.

Another example may include providing an indication of the selected RA procedure in higher layer signaling (eg, RRC signaling). In one example, RRC signaling may configure the RA procedure type for UE 104 when UE 104 is in RRC_CONNECTED mode. This indication method may be limited to situations where UE 104 has completed initial access, and may not be applicable for indication of the selected RA procedure for initial access. For example, the selected PRACH indication method may be used when the UE 104 is in RRC connected mode and needs to perform the selected RA procedure for UL synchronization and/or scheduling requests. This selected PRACH indication method can also be used in handover situations when a contention based PRACH has been issued. This selected PRACH indication method may also be used for RRC reconnection in the event that the UE 104 attempts to recover from a radio link failure.

Embodiments described herein may be implemented in a system using any suitably configured hardware and/or software. FIG. 2 shows a block diagram of components of a user equipment (UE) device 200 according to an embodiment of the disclosure. UE 200 may be implemented in UE 104 in FIG. 1 . In some embodiments, UE device 200 may include application circuitry 202, baseband circuitry 204, radio frequency (RF) circuitry 206, front end module (FEM) circuitry 208, and one or more antennas 210 coupled together at least as shown. .

Application circuitry 202 may include one or more application processors. For example, application circuitry 202 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general and special purpose processors (eg, graphics processors, application processors, etc.). The processor may be coupled to and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system .

Baseband circuitry 204 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. Baseband circuitry 204 may include one or more baseband processors and/or control logic to process baseband signals received from the receive signal path of RF circuitry 206 and generate baseband signals for the transmit signal path of RF circuitry 206 . Baseband processing circuitry 204 may interface with application circuitry 202 for generation and processing of baseband signals and control the operation of RF circuitry 206 . For example, in some embodiments, the baseband circuit 204 may include a second generation (2G) baseband processor 204a, a third (3G) baseband processor 204b, a fourth generation (4G) baseband processor 204c, and/or for Other baseband processor(s) 204d of other existing generations, generations in development, or generations to be developed in the future (eg, fifth generation (5G), 6G, etc.). Baseband circuitry 204 (eg, one or more of baseband processors 204 a - d ) may handle various radio control functions that enable communication with one or more radio networks via RF circuitry 206 . Radio control functions may include, but are not limited to: signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 204 may include Fast Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 204 may include convolutional, tail-biting convolutional, turbo, Viterbi, and/or low-density parity-check (LDPC) encoders /decoder function. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples, and other suitable functionality may be included in other embodiments.

In some embodiments, baseband circuitry 204 may include elements of a protocol stack, for example, elements of the Evolved Universal Terrestrial Radio Access Network (EUTRAN) protocol, including, for example, physical (PHY) elements, medium access control (MAC) elements, radio link A Road Control (RLC) element, a Packet Data Convergence Protocol (PDCP) element, and/or a Radio Resource Control (RRC) element. Central processing unit (CPU) 204e of baseband circuitry 204 may be configured to run elements of a protocol stack for PHY, MAC, RLC, PDCP, and/or RRC layer signaling. In some embodiments, the baseband circuitry may include one or more audio digital signal processors (DSPs) 204f. Audio DSP(s) 204f may be or include elements for compression/decompression and echo cancellation, and in other embodiments may include other suitable processing elements. In some embodiments, the components of the baseband circuitry may be suitably combined in a single chip or a single chipset, or arranged on the same circuit board. In some embodiments, some or all of the constituent components of baseband circuitry 204 and application circuitry 202 may be implemented together, eg, on a system-on-chip (SOC).

In some embodiments, baseband circuitry 204 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 204 may support communication with Evolved Universal Terrestrial Radio Access Network (EUTRAN) and/or other Wireless Metropolitan Area Networks (WMAN), Wireless Local Area Networks (WLAN), Wireless Personal Area Networks (WPAN) communication. Embodiments in which baseband circuitry 204 is configured to support radio communications for more than one wireless protocol may be referred to as multi-mode baseband circuitry.

RF circuitry 206 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, RF circuitry 206 may include switches, filters, amplifiers, etc. to facilitate communication with a wireless network. RF circuitry 206 may include a receive signal path that may include circuitry that downconverts the RF signal received from FEM circuitry 208 and provides a baseband signal to baseband circuitry 204 . RF circuitry 206 may also include a transmit signal path, which may include circuitry that upconverts the baseband signal provided by baseband circuitry 204 and provides the RF output signal to FEM circuitry 208 for transmission.

In some embodiments, RF circuitry 206 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuit 206 may include a mixer circuit 206a, an amplifier circuit 206b, and a filter circuit 206c. The transmit signal path of the RF circuit 206 may include a filter circuit 206c and a mixer circuit 206a. The RF circuit 206 may also include a synthesizer circuit 206d for synthesizing frequencies for use by the mixer circuit 206a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 206a of the receive signal path may be configured to downconvert the RF signal received from the FEM circuit 208 based on the synthesized frequency provided by the synthesizer circuit 206d. Amplifier circuit 206b may be configured to amplify the down-converted signal, and filter circuit 206c may be a low-pass filter (LPF) or filter circuit 206c configured to remove unwanted signals from the down-converted signal to generate an output baseband signal. Band Pass Filter (BPF). The output baseband signal may be provided to baseband circuitry 204 for further processing. In some embodiments, the output baseband signal may be a zero-frequency baseband signal, but this is not a requirement. In some embodiments, the mixer circuit 206a of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 206a of the transmit signal path may be configured to upconvert the input baseband signal based on the synthesized frequency provided by the synthesizer circuit 206d to generate an RF output signal for the FEM circuit 208 . The baseband signal may be provided by baseband circuitry 204 and may be filtered by filter circuitry 206c. Filter circuit 206c may include a low pass filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and /or quadrature upconversion. In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may comprise two or more mixers and may be arranged for image rejection (e.g., Hart Hartley image suppression). In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, RF circuitry 206 may include analog-to-digital converter (ADC) circuitry and digital-to-analog converter (DAC) circuitry, and baseband circuitry 204 may include a digital baseband interface to communicate with RF circuitry 206 .

In some dual-mode embodiments, separate radio IC circuits may be provided to process signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, the synthesizer circuit 206d may be a fractional N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect, as other types of frequency synthesizers may be suitable. For example, the synthesizer circuit 206d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider.

The synthesizer circuit 206d may be configured to synthesize an output frequency for use by the mixer circuit 206a of the RF circuit 206 based on the frequency input and the divider control input. In some embodiments, combiner circuit 206d may be a fractional N/N+1 combiner.

In some embodiments, the frequency input may be provided by a voltage controlled oscillator (VCO), but this is not required. The frequency divider control input may be provided by baseband circuitry 204 or application processor 202 according to the desired output frequency. In some embodiments, the frequency divider control input (eg, N) may be determined from a lookup table based on the channel indicated by the applications processor 202 .

The combiner circuit 206d of the RF circuit 206 may include a frequency divider, a delay locked loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the frequency divider may be a dual-modulus divider (DMD), and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or N+1 (eg, based on a carry out) to provide a fractional divide ratio. In some example embodiments, a DLL may include a cascaded set of tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to break up the VCO cycle into Nd equal phase groupings, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, the synthesizer circuit 206d may be configured to generate a carrier frequency as an output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) , and used in conjunction with a quadrature generator and frequency divider circuit to generate multiple signals at a carrier frequency with multiple phases different from each other. In some embodiments, the output frequency may be the LO frequency (fLO). In some embodiments, RF circuit 206 may include an IQ/polarity converter. In some embodiments, RF circuitry 206 may include a MIMO transceiver.

The FEM circuitry 208 may include a receive signal path that may include RF signals configured to manipulate received RF signals from one or more antennas 210, amplify the received signals, and provide an amplified version of the received signals to the RF Circuit 206 is a circuit for further processing. The FEM circuit 208 may also include a transmit signal path that may include a signal configured to amplify the signal for transmission provided by the RF circuit 206 for reception by one or more of the one or more antennas 210. transmission circuit.

In some embodiments, FEM circuit 208 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuit may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuit may include a low noise amplifier (LNA) to amplify the received RF signal and provide the amplified received RF signal as an output (eg, to the RF circuit 206 ). The transmit signal path of FEM circuitry 208 may include a power amplifier (PA) to amplify the input RF signal (e.g., provided by RF circuitry 206) and may include one or more filters to generate RF signals transmitted by one or more of the one or more antennas 210).

In some embodiments, UE device 200 may include additional elements such as memory/storage, display, camera, sensor, and/or input/output (I/O) interfaces.

In operation, UE device 200 may communicate over both licensed and unlicensed spectrum (eg, via baseband circuitry 204, RF circuitry 206, and FEM circuitry 208). In some examples, UE device 200 may support simultaneous transmission over licensed spectrum (eg, PCell) and unlicensed spectrum (eg, SCell). To provide UL data to the eNodeB, UE device 200 may initiate an SR via PRACH signaling (eg, via FEM circuit 208). In addition to SR, PRACH signals may be used for uplink (UL) synchronization and power control for initial UL transmissions. Because LBT is implemented, the RA procedure may experience large delays and may limit UL transmissions. It should be understood that the LBT process and PRACH transmission may be performed by at least one combination of baseband circuitry 204 , RF circuitry 206 , and FEM circuitry 208 .

In one embodiment supporting low-latency RA procedures in unlicensed spectrum, UE device 200 may support low-latency two-step RA procedures (eg, in addition to LBT procedures). In the first step of the low-latency two-step RA procedure, UE device 200 may provide a first transmission on the allocated PRACH resource in response to the CCA indicating that the channel is idle (eg, according to the LBT procedure). In one example, the first transmission may include a PRACH preamble and a message portion including (e.g., temporary or assigned) C-RNTI, BSR information, UE device 200 capabilities, and message 3, which 3 may include the identity of the UE device 200 (eg, may be used for contention resolution). In some examples, the message portion may also include a CCCH subheader. The message part may include a MAC part including possible C-RNTI, BRS information, and L1/MAC UE capabilities, and an RRC part including an RRC message with UE identity for contention resolution. Alternatively, UE identity for contention resolution can be included in the MAC part. In a second step, UE device 200 may receive a second transmission including RAR and/or Message 4 via PDCCH/ePDCCH using the C-RNTI received from UE 104 in the first transmission, or based on One of the common random access RNTIs (RA-RNTIs) calculated from the time-frequency resource used by the first transmitted preamble is scheduled.

The UL grant assignment may be included in the message part of the RAR, the PDCCH/ePDCCH with the assigned C-RNTI of the UE device 200, or the PDCCH/ePDCCH with the assigned RA-RNTI. If included in the PDCCH/ePDCCH with the assigned C-RNTI of the UE device 200, the UE device 200 can decode the downlink DL masked with the assigned C-RNTI of the UE for scheduling RAR/message 4 DCI and UL authorized. If included in the PDCCH/ePDCCH with the RA-RNTI, the UE device 200 may decode the DL grant for scheduling the RAR/message 4 and the UL grant for scheduling the PUSCH masked with the allocated RA-RNTI.

In another embodiment supporting low-latency RA procedures in unlicensed spectrum, UE device 200 may support low-latency one-step RA procedures (eg, in addition to LBT procedures). For example, UE device 200 may provide a first transmission on the allocated PRACH resource in response to the CCA indicating that the channel is idle (eg, according to an LBT procedure). The first transmission may include a PRACH preamble and a message portion including (e.g., temporary or assigned) C-RNTI, BSR information, CCCH subheader, and Message 3, which may include the UE device 200 Identification (eg, can be used for contention resolution at the eNodeB). The message part may include a medium access control (MAC) part and an RRC part, the MAC part includes temporary C-RNTI, BRS information, CCCH subheader, and Layer 1 (L1)/MAC UE capability, and the RRC part includes content information for contention resolution RRC message of UE identity. Alternatively, UE identity for contention resolution can be included in the MAC part. The first transmission may use a physical uplink control channel (PUCCH) waveform, where the first n symbols may be used for a PRACH preamble and the remaining m symbols may be used for data (eg, BSR, message 3) transmission. The duration of sPUCCH can be up to 4 symbols. The sPUCCH may have an interlace structure with 10 Physical Resource Blocks (PRBs) per interlace in a 20MHz system. One or more interlaces may be allocated to UE device 200 for UL transmission.

If the UL grant is received within a predetermined amount of time (e.g., within k subframes, or before the MAC contention resolution timer for the C-RNTI (indicating successful contention resolution) has expired), the UE device 200 UL data can be sent normally. The UL grant may be included in a message scheduled with the C-RNTI received from the UE device 200 for the UL grant via the PDCCH/ePDCCH. Otherwise, UE device 200 may send another first transmission with the new random preamble index at the configured PRACH subframe. The time window of k subframes may be counted in terms of absolute time (eg, Key Management Service (KMS) time) or in terms of valid DL subframes (eg, subframes with DL transmission).

For the first transmission of the UE device 200 in the two-step process or the one-step process, the first N symbols may be used to transmit the PRACH preamble. The PRACH preamble can also be used for channel estimation after detection. The remaining M symbols can be used for data transmission (eg, C-RNTI, BSR information, CCCH subheader, message 3, etc.). In one embodiment, when PRACH is transmitted through sPUCCH resources, N and M may be equal to 2, which may occupy the last 4 SC-FDMA symbols of the special subframe. If the payload size increases beyond the available payload of a single interlace, additional interlaces may be allocated to the UE device 200, or the coding rate may be reduced to allow higher density transmissions.

When the PRACH preamble requires four symbols on the PUCCH, the Physical Uplink Shared Channel (PUSCH) subframe following the PUCCH can be used to carry the first transmitted message parts (e.g., C-RNTI, BSR information, CCCH subframe header, and message 3). One or more interlaces of the PUSCH subframe may be allocated for the first transmission, and multiple UEs may be multiplexed in the frequency and/or code domain. In order to reduce the probability of collision, fewer users can be allocated to transmit through the PUSCH subframe. The PRACH preamble sequence can be used for channel estimation. The same structure as conventional PUSCH transmission can be used, where demodulation reference signal (DMRS) symbols can be used for channel estimation. If the first transmitted message part (e.g., C-RNTI, BSR information, message 3, and CCCH subheader) transmitted simultaneously on the allocated PRACH resource cannot be correctly detected, but the PRACH preamble sequence is correctly detected , then the two-step/one-step PRACH can fall back to the traditional RA process.

In systems where UE device 200 supports more than one RA procedure (eg, a combination of traditional RA procedures, two-step RA procedures, and one-step RA procedures), the eNodeB and/or UE device 200 may indicate which methods they support or intend to use. In a UE-specific example, UE device 200 may receive an assignment of an RA procedure from an eNodeB when UE device 200 is in RRC mode.

In the cell-specific procedure, the UE device 200 may receive from the eNodeB an indication of which of the traditional RA procedures, two-step RA procedures, and/or one-step RA procedures the eNodeB supports, and the UE device 200 may determine which one to use RA process. One example of a method of indicating the selected RA procedure to the eNodeB by the UE device 200 may include using a PRACH preamble signature associated with the selected RA procedure. For example, the eNodeB may specify a specific set of preamble signatures for each supported RA procedure. The UE device 200 may use a preamble signal of a set of preamble signatures associated with the selected RA procedure, and the eNodeB may detect the selected RA procedure by detecting the preamble signature.

The UE device 200 may receive an indication of the selected RA procedure in a master information block (MIB). The eNodeB may set the PRACH indication in the MIB to a specific value associated with the selected or supported RA procedure. In one example, the eNodeB 120 may set one or more reserved bits in the payload of the MIB block, or one or more additional bits in the payload of the updated MIB block, to be associated with the selected RA procedure. Specific value to indicate the selected RA process.

Another example of a method for the UE device 200 to receive an indication of the selected or supported RA procedure is to receive in a system information block (SIB) or an extended SIB (eSIB). The eNodeB may set the selected RA procedure indication in the SIB/eSIB to a specific value associated with the selected RA procedure, and the UE device 200 may detect the selected RA procedure indication based on the selected RA procedure indication in the SIB/eSIB RA process. In one example, the PRACH configuration index parameter of SIB2/eSIB2 may be extended to include support for one or both of a two-step RA procedure and a one-step RA procedure. The eNodeB may indicate the selected RA process by setting the Extended PRACH Configuration Index parameter in SIB2/eSIB2 to a specific value associated with the selected RA process. In another example, new parameters may be added to the SIB/eSIB (eg, in the PRACH configuration field of SIB2/eSIB2) for one or both of the two-step RA procedure and the one-step RA procedure. The eNodeB may indicate the selected RA procedure by setting parameters associated with the selected RA procedure in the PRACH configuration field of SIB2/eSIB2.

Another example of the method of indicating the selected RA procedure to the eNodeB by the UE device 200 may include an indication of the selected RA procedure associated with the SIB/eSIB (for example, extending the PRACH configuration parameter in the PRACH configuration field of the SIB2/eSIB2 or additional parameters).

Another example may include providing an indication of the selected RA procedure in higher layer signaling (eg, RRC signaling). In one example, when the UE device 200 is in the RRC connected mode, the RRC signaling may configure the RA procedure type for the UE device 200 . This indication method may be limited to the case that the UE device 200 has completed the initial access, and may not be applicable to the indication of the selected RA procedure for the initial access.

FIG. 3 illustrates a signal diagram 300 for a low-latency two-step RA procedure, according to some embodiments of the present disclosure. In an example, a low-latency two-step RA procedure may be established between UE 304 and eNodeB 320 . UE 304 may be implemented by UE 104 in FIG. 1 , UE device 200 in FIG. 2 , or a combination thereof. The eNodeB 320 can be implemented by the eNodeB 120 in FIG. 1 .

UE 304 can communicate with eNodeBs using unlicensed spectrum. Initially, UE 304 may perform LBT procedures. In response to the CCA, UE 304 may provide eNodeB 320 with a first transmission [1]. In one example, the first transmission [1] may include a PRACH preamble and a message part including (e.g., temporary or assigned) C-RNTI, Buffer Status Report (BSR) information, UE 304 capabilities , and message 3, which may include the identity of UE 304 (eg, may be used for contention resolution). In some examples, the message portion may also include a Common Control Channel (CCCH) subheader. The message part may include a Medium Access Control (MAC) part and a Radio Resource Control (RRC) part. The MAC part includes possible C-RNTI, BRS information, and Layer 1 (L1)/MAC UE capabilities. The RRC part includes RRC message identified with the addressed UE. Alternatively, UE identity for contention resolution can be included in the MAC part.

In a second step, the eNodeB 320 may provide a second transmission [2] including the RAR and/or message 4 in response to the CCA (e.g. according to the LBT procedure), which is used via the PDCCH/ePDCCH in The C-RNTI received from the UE 304 in the first transmission, or the common random access RNTI (RA-RNTI) calculated based on the time-frequency resource used by the preamble of the first transmission is scheduled.

Contention resolution may be performed based on one of the PDCCH/ePDCCH, or either the MAC part or the RRC part (eg, whichever was provided by the UE 304 in the first transmission). In the PDCCH/ePDCCH based case, contention resolution may be considered successful if the PDCCH/ePDCCH includes the UE's allocated C-RNTI. In the case based on the MAC part, contention resolution may be considered successful if the MAC part includes the UE 304's assigned C-RNTI or UE 304 identity provided in the first transmission. In the RRC part based case, contention resolution may be considered if the RRC message of the RRC part provided in the first transmission includes the allocated C-RNTI of the UE 304 or the identity of the UE 304 provided in the first transmission success.

The UL grant assignment may be included in the message part of the RAR, the PDCCH/ePDCCH with the assigned C-RNTI of the UE 304, or the PDCCH/ePDCCH with the assigned RA-RNTI. If included in the PDCCH/ePDCCH with the assigned C-RNTI of the UE 304, the UE 304 can decode the downlink DL DCI for scheduling RAR/message 4 masked with the assigned C-RNTI of the UE 304 and UL authorization. If included in the PDCCH/ePDCCH with RA-RNTI, the UE 304 can decode the DL grant for scheduling RAR/Message 4 and the UL grant for scheduling PUSCH masked with the assigned RA-RNTI.

FIG. 4A illustrates a signal diagram 400 for a failed low-latency single-step RA procedure, according to some embodiments of the present disclosure. FIG. 4B illustrates a signal diagram 401 for a successful low-latency single-step RA procedure, according to some embodiments of the present disclosure. In an example, a low-latency one-step RA procedure can be established between UE 404 and eNodeB 420 . UE 404 may be implemented by UE 104 in FIG. 1 , UE device 200 in FIG. 2 , or a combination thereof. The eNodeB 420 can be implemented by the eNodeB 120 in FIG. 1 .

UE 404 can communicate with eNodeBs using unlicensed spectrum. Initially, UE 404 may perform LBT procedures. In response to the CCA, UE 404 may provide a first transmission [1] on the allocated PRACH resources. The first transmission may include a PRACH preamble and a message portion including (e.g., temporary or assigned) C-RNTI, BSR information, CCCH subheader, and message 3, which may include the identity of UE 404 (for example, can be used for contention resolution). The message part may include a MAC part including Temporary C-RNTI, BRS information, CCCH subheader, and L1/MAC UE capability, and an RRC part including an RRC message with UE ID for contention resolution. Alternatively, UE identity for contention resolution can be included in the MAC part. The first transmission may use the PUCCH waveform, where the first n symbols may be used for the PRACH preamble, and the remaining m symbols may be used for data (eg, BSR, message 3) transmission. The duration of sPUCCH can be up to 4 symbols. The sPUCCH may have an interlace structure with 10 Physical Resource Blocks (PRBs) per interlace in a 20MHz system. One or more interlaces can be allocated to UE 404 for UL transmission.

Contention resolution may be performed based on one of the PDCCH/ePDCCH, or MAC part or RRC part (eg, whichever was provided by UE 404 in the first transmission). In the PDCCH/ePDCCH based case, contention resolution may be considered successful if the PDCCH/ePDCCH includes the UE's allocated C-RNTI. In the case based on the MAC part, contention resolution may be considered successful if the MAC part includes the assigned C-RNTI of the UE 404, or the UE 404 identity provided in the first transmission. In the RRC part based case, if the RRC message of the RRC part provided in the first transmission includes the allocated C-RNTI of the UE 404, or the identity of the UE 404 provided in the first transmission, contention resolution can be resolved by Think successful.

The UL grant assignment may be included in the message part of the RAR, the PDCCH/ePDCCH with the assigned C-RNTI of the UE 404, or the PDCCH/ePDCCH with the assigned RA-RNTI. If included in the PDCCH/ePDCCH with the assigned C-RNTI of the UE 404, the UE 404 can decode the downlink DL DCI for scheduling RAR/message 4 masked with the assigned C-RNTI of the UE 404 and UL authorization. If included in the PDCCH/ePDCCH with RA-RNTI, the UE 404 can decode the DL grant for scheduling RAR/Message 4 and the UL grant for scheduling PUSCH masked with the assigned RA-RNTI.

If the UL grant is received within a predetermined amount of time (e.g., within k subframes, or before the MAC contention resolution timer for the C-RNTI (indicating successful contention resolution) has expired), the UE 404 may Send UL data normally. The UL grant may be included in a message scheduled via the PDCCH/ePDCCH with the C-RNTI received from the UE 104 for the UL grant. Otherwise, the UE 404 may send another first transmission [4] with the new random preamble index at the configured PRACH subframe, as shown in the signal diagram 400 . The time window of k subframes may be counted in terms of absolute time (eg, Key Management Service (KMS) time) or in terms of valid DL subframes (eg, subframes with DL transmission).

FIG. 5 shows a flowchart of a method 500 for performing a low-latency RA procedure according to some embodiments of the present disclosure. The method 500 may be implemented in any one of the UE 104 in FIG. 1 , the UE device 200 in FIG. 2 , the UE 304 in FIG. 3 , and the UE 404 in FIG. 4 , or a combination thereof.

Method 500 can include, at 510, performing a listen-before-talk (LBT) procedure on one or more channels of an unlicensed spectrum.

Method 500 can also include, at 520, encoding a first transmitted first message associated with a low-latency random access (RA) procedure on an unlicensed spectrum in response to a clear channel assessment (CCA). The first message may include a PRACH preamble and a message part. The message part may include at least one of C-RNTI, BSR information, capabilities of the UE, and identity of the UE. In some examples, the message portion includes a MAC portion, and the MAC portion includes a MAC message. The MAC message may include at least one of C-RNTI, BSR information, and UE capabilities. The MAC message may also include the identity of the UE. In some examples, the message part may also include an RRC part, which includes an RRC message. The RRC message may include the identity of the UE. The capabilities of the UE may include one of layer 1 UE capabilities, or MAC UE capabilities. The message part may also include a CCCH subheader. The first transmission may use a shortened physical uplink control channel (sPUCCH) waveform, where the first part includes the PRACH preamble and the remaining part includes the message part. In some examples, the first portion includes the first two symbols of message 3 and the remaining portion includes the next two symbols after the first two symbols of message 3 .

In some examples, low-latency RA procedures (e.g., via MIB, SIB /eSIB or RRC signaling) to encode the first message.

Method 500 may also include decoding a second message received in a second transmission associated with a low-latency RA procedure scheduled via a physical downlink control channel (PDCCH). The second message may include a Physical Downlink Shared Channel (PDSCH) transmission including a UL grant and including at least one of a random access response or Message 4 . In some examples, the DCI used to schedule the second message is scrambled via one of the C-RNTI or the RA-RNTI.

The low-latency RA procedure may also include scheduling UL transmissions in response to receiving the UL grant based on the first transmission.

The method may also include, in response to not receiving a UL grant based on the first transmission within a predetermined length of time after the first transmission, encoding a second message of the second transmission on the unlicensed spectrum. The second message may include a second PRACH preamble and a message portion. The predetermined length of time may be based on one of absolute time, a count of valid downlink subframes, or a MAC contention resolution timer. Method 500 can also include, at 530, in response to receiving an uplink (UL) grant based on the first step of the low-latency RA procedure, encoding UL data for transmission.

FIG. 6 shows a flowchart of a method 600 for performing a low-latency RA procedure according to some embodiments of the present disclosure. The method 600 may be implemented in any one of the UE 104 in FIG. 1 , the UE device 200 in FIG. 2 , the UE 304 in FIG. 3 , and the UE 404 in FIG. 4 , or a combination thereof.

Method 600 can include, at 610, receiving an indication that a serving eNodeB supports low-latency RA procedures and legacy RA procedures.

Method 600 can also include, at 620, encoding a first transmitted first message associated with a low-latency RA procedure, the first message including a PRACH preamble and a message portion. Method 600 may also include providing an indication to the serving eNodeB to select a low-latency RA procedure. In some examples, providing the indication may include selecting a preamble from a set of PRACH preambles specified for a low-delay RA procedure. In some examples, providing the indication may include selecting time and/or frequency resources for PRACH preamble transmission. Time and/or frequency resources may be dedicated to low-latency RA procedures. Method 600 can also include receiving time and/or frequency resources dedicated for PRACH preamble transmission from the serving eNodeB.

In some examples, method 600 can include receiving an indication of selection of a low-latency RA procedure from a serving eNodeB. In some examples, method 600 can include receiving an indication of selection of a low-latency RA procedure from a serving eNodeB. For example, receiving an indication of selection of a low-latency RA procedure from the serving eNodeB may include determining selection of a low-latency RA procedure based on a PRACH_ConfigIndex parameter in a system information block 2 (SIB2) or extended SIB2 (eSIB2). In another example, receiving an indication of the selection of the low-delay RA procedure from the serving eNodeB may include determining the selection of the low-delay RA procedure based on SIB2 or a PRACH configuration field in eSIB2. In some examples, receiving an indication of the selection of the low-latency RA procedure from the serving eNodeB may include determining the selection of the low-latency RA procedure based on a value of one or more reserved bits in the master information block. In some examples, receiving an indication of the selection of the low-latency RA procedure from the serving eNodeB may include receiving the selected RA procedure in radio resource control signaling.

FIG. 7 shows a flowchart of a method 700 for performing a low-latency RA procedure according to some embodiments of the present disclosure. The method 700 may be implemented in any one of eNodeB 120 in FIG. 1 , eNodeB 320 in FIG. 3 , eNodeB 420 in FIG. 4 , or a combination thereof.

Method 700 can include, at 710, decoding a first message received from a UE in a first transmission associated with a low-latency RA procedure on an unlicensed spectrum. The first message may include a PRACH preamble and a message part. The message part may include at least one of a Cell Radio Network Temporary Identifier (C-RNTI), Buffer Status Report (BSR) information, capabilities of the UE, or identity of the UE. The message part may include a Media Access Control (MAC) part, the MAC part including a MAC message. The MAC message may include at least one of a C-RNTI, BSR information, or capabilities of the UE, wherein performing contention resolution includes the processing circuit determining whether the MAC portion includes the C-RNTI. In some examples, the message portion may also include a radio resource control (RRC) portion, which includes RRC messages. The RRC message may include the identity of the UE. In some examples, the message portion may also include a Common Control Channel (CCCH) subheader.

Method 700 can also include, at 720, performing a listen-before-talk (LBT) procedure on one or more channels of the unlicensed spectrum. Method 700 can also include, at 730, encoding a second transmitted second message associated with the low-latency RA procedure in response to the clear channel assessment. The second message may include at least one of RAR or Message 4. The second message may be scheduled via a Physical Downlink Control Channel (PDCCH), and/or the second message includes an uplink (UL) grant. In some examples, the second message, PDSCH, may be scheduled via downlink control information (DCI) scrambled by one of a C-RNTI or a random access RNTI (RA-RNTI).

In some examples, method 700 may further include determining the UE's selection of the low-delay RA procedure based on a comparison of the PRACH preamble with a set of PRACH preambles specified for the low-delay RA procedure. In some examples, determining the selection of the low-latency RA procedure may include determining the selection based on a set of time and/or frequency resources used for the first transmission. In some examples, method 700 may also include indicating selection of a low-latency RA procedure based on one or more bits in a master information block or a system information block.

8 generally illustrates an example of a block diagram of a machine 800 on which any one or more techniques (eg, methods) discussed herein may be performed in accordance with some embodiments. In alternative embodiments, machine 800 may operate as a standalone device, or may be connected (eg, networked) to other machines. In a networked deployment, the machine 800 can operate as a server machine, a client machine, or both in a server-client network environment. In an example, machine 800 may function as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. Machine 800 may be a personal computer (PC), tablet PC, set top box (STB), personal digital assistant (PDA), mobile phone, web appliance, network router, switch, or bridge, or a computer capable of performing actions specified for the machine to take. An arbitrary machine of instructions (sequential or otherwise). In addition, while a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods discussed herein. Various methods, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

Examples as described herein may comprise or may operate on logic or multiple components, modules, or mechanisms. A module is a tangible entity (eg, hardware) capable of performing specified operations when operated. Modules include hardware. In an example, hardware may be specifically configured (eg, hardwired) to perform certain operations. In an example, hardware may include configurable execution units (eg, transistors, circuits, etc.) and a computer-readable medium including instructions that, when operative, configure the execution units to perform certain operations. Configuration can be directed by the execution unit or the loading mechanism. Thus, in operation of the apparatus, the execution unit is communicatively coupled to the computer-readable medium. In this example, an execution unit may be a member of more than one module. For example, under operation, an execution unit may be configured by a first set of instructions to implement a first module at one point in time, and reconfigured by a second set of instructions to implement a second module.

Machine (e.g., computer system) 800 may include a hardware processor 802 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), main memory 804, and static memory 806 , some or all of which may communicate with each other via an interlink (eg, bus) 808 . Machine 800 may also include a display unit 810, an alphanumeric input device 812 (eg, a keyboard), and a user interface (UI) navigation device 814 (eg, a mouse). In an example, the display unit 810, the alphanumeric input device 812, and the UI navigation device 814 may be a touch screen display. The machine 800 may also include a storage device (e.g., a drive unit) 816, a signal generating device 818 (e.g., a speaker), a network interface device 820, and one or more sensors 821, such as a global positioning system (GPS) sensor, compass, Accelerometer, or other sensors. Machine 800 may include an output controller 828, e.g., for communicating with or controlling serial communication with one or more peripheral devices (e.g., printers, card readers, etc.) Serial (eg, Universal Serial Bus (USB)), parallel, or other wired or wireless (eg, infrared (IR), near field communication (NFC), etc.) connections.

Storage devices 816 may include non-transitory machine-readable media 822 having stored thereon one or more sets of data structures or instructions 824 (e.g., software) embodying techniques or functions described herein Any one or more of the techniques or functions in, or utilized by, any one or more of the techniques or functions described herein. Instructions 824 may also reside, completely or at least partially, within main memory 804 , within static memory 806 , or within hardware processor 802 during execution by machine 800 . In an example, one or any combination of hardware processor 802, main memory 804, static memory 806, or storage device 816 may constitute a machine-readable medium.

Although machine-readable medium 822 is shown as a single medium, the term "machine-readable medium" may include a single medium or multiple media configured to store one or more instructions 824 (e.g., a centralized or distributed database, and/or associated caches and servers).

The term "machine-readable medium" may include instructions capable of storing, encoding, or carrying instructions executed by the machine 800 and causing the machine 800 to perform any one or more of the techniques of the present disclosure, or capable of storing, encoding, or carrying such instructions. Any medium of data structures used by instructions or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memory, and optical and magnetic media. In an example, a mass machine-readable medium includes a machine-readable medium having a plurality of particles having a constant (eg, rest) mass. Accordingly, a mass machine-readable medium is not a transitory propagating signal. Specific examples of large-capacity machine-readable media may include nonvolatile memories such as semiconductor memory devices (e.g., Electronically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and Flash memory devices; magnetic disks, such as internal and removable hard disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

It can also be transmitted via any one of a number of transmission protocols (for example, Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc. Protocol network interface device 820 to use transmission media to send or receive instructions 824 over communication network 826 . Example communication networks may include: local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile telephone networks (e.g., cellular networks), plain old telephone (POTS) networks, and wireless data networks (e.g., is called The Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards, known as IEEE 802.16 standard family), IEEE 802.15.4 standard family, peer-to-peer (P2P) network and so on. In an example, network interface device 820 may include one or more physical jacks (eg, Ethernet, coaxial, or telephone jacks) or one or more antennas to connect to communication network 826 . In an example, the network interface device 820 may include multiple antennas to communicate wirelessly using at least one of: single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) technology. The term "transmission medium" shall be taken to include any intangible medium capable of storing, encoding, or carrying instructions for execution by machine 800, and includes digital or analog communication signals or other intangible media to facilitate communication of such software.

As used herein, the term "circuitry" may refer to, may be part of, or may include the following: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a (shared , dedicated, or group) processor and/or memory (shared, dedicated, or group), combinational logic, and/or other suitable hardware components that provide the described functionality. In some embodiments, a circuit may be implemented in one or more software or firmware modules, or functionality associated with a circuit may be implemented by one or more software or firmware modules. In some embodiments, circuitry may include logic at least partially operable in hardware.

In some embodiments, UE device 1000 may include additional elements such as memory/storage, display, camera, sensors, and/or input/output (I/O) interfaces.

Additional notes and examples:

Example 1 is an apparatus of a user equipment (UE), comprising: a memory; and processing circuitry for: performing a listen before talk (LBT) procedure on one or more channels of an unlicensed spectrum; and responding For clear channel assessment (CCA), a first transmitted first message associated with a low-delay random access (RA) procedure is encoded on an unlicensed spectrum, wherein the first message includes a PRACH preamble and at least One, wherein the message part includes at least one of Cell Radio Network Temporary Identifier (C-RNTI), Buffer Status Report (BSR) information, UE capabilities, and/or UE identity; An uplink (UL) grant is received and UL data is encoded for transmission.

In Example 2, the subject matter of Example 1 optionally includes wherein the message portion includes a Medium Access Control (MAC) portion, the MAC portion includes at least one MAC message, wherein the MAC message includes C-RNTI, BSR information, or at least one of the capabilities.

In Example 3, the subject matter of Example 2 optionally includes wherein the MAC message further includes an identification of the UE.

In Example 4, the subject matter of any one or more of Examples 2-3 optionally includes wherein the message portion further includes a Radio Resource Control (RRC) portion, the RRC portion includes an RRC message, wherein the RRC message includes the UE's logo.

In Example 5, the subject matter of any one or more of Examples 2-4 optionally includes wherein the capabilities of the UE include one of layer 1 UE capabilities, or MAC UE capabilities.

In Example 6, the subject matter of any one or more of Examples 1-5 optionally includes wherein the message portion further includes a Common Control Channel (CCCH) subheader.

In Example 7, the subject matter of Example 6 optionally includes wherein the processing circuit is configured to encode on the unlicensed spectrum in response to not receiving a UL grant based on the first transmission within a predetermined length of time after the first transmission The second message is sent second, where the second message includes a second PRACH preamble and a message part.

In Example 8, the subject matter of Example 7 optionally includes wherein the predetermined length of time is based on one of an absolute time, a count of valid downlink subframes, or a MAC contention resolution timer.

In Example 9, the subject matter of any one or more of Examples 1-8 optionally includes, wherein the first transmission uses a shortened physical uplink control channel (sPUCCH) waveform, wherein the first portion includes a PRACH preamble , and the remainder includes the message part.

In Example 10, the subject matter of Example 9 optionally includes wherein the first portion includes the first two symbols of message 3, and wherein the remaining portion includes the next two symbols after the first two symbols of message 3.

In Example 11, the subject matter of any one or more of Examples 1-10 optionally includes wherein the first transmission comprises one or more of the first shortened physical uplink control channel (sPUCCH) subframes The PRACH preamble is transmitted in the symbol, and the message part is transmitted in the second sPUCCH subframe.

In Example 12, the subject matter of any one or more of Examples 1-11 optionally includes, wherein the processing circuit is configured to: decode a low-latency RA procedure associated with a low-latency RA process scheduled via a Physical Downlink Control Channel (PDCCH) A second message received in a second transmission of the connection, wherein the second message comprises a physical downlink shared channel (PDSCH) transmission, the PDSCH transmission comprises a UL grant and comprises at least one of a random access response or a contention resolution message .

In Example 13, the subject matter of Example 12 optionally includes wherein the downlink control information (DCI) used to schedule the second message is received via one of a C-RNTI, or a random access RNTI (RA-RNTI) scrambling.

In Example 14, the subject matter of any one or more of Examples 1-13 optionally includes wherein the processing circuit initiates the low-latency RA procedure based on receiving an indication that the serving evolved NodeB (eNodeB) supports the low-latency RA procedure of.

In Example 15, the subject matter of Example 14 optionally includes wherein the processing circuit is configured to: indicate to the eNodeB the need for the low-delay RA procedure based on selecting the PRACH preamble from a set of PRACH preambles specified for the low-delay RA procedure s Choice. .

In Example 16, the subject matter of any one or more of Examples 14-15 optionally includes wherein the processing circuitry is configured to: select time and/or frequency resources dedicated to PRACH preamble transmission for low-delay RA procedures based on , to indicate to the eNodeB the selection of the low-latency RA procedure.

In Example 17, the subject matter of any one or more of Examples 1-16 optionally includes wherein the processing circuit is configured to encode the first message in response to a size of the first message exceeding a size allocated to a single PRACH interlace for sending on multiple PRACH interlaces.

In Example 18, the subject matter of any one or more of Examples 1-17 optionally includes wherein the processing circuit is configured to: encode the message portion for transmission on the plurality of PRACH interlaces.

In Example 19, the subject matter of any one or more of Examples 1-18 optionally includes wherein the processing circuit is configured to reduce the size of the first message in response to the size of the first message exceeding the size allocated to a single PRACH interlace. The size of a message.

Example 20 is an apparatus of a user equipment (UE), the apparatus comprising: a memory; and a processing circuit configured to: receive a service evolved Node B (eNodeB) supporting a low-latency random access (RA) procedure and a legacy RA procedure indicating; and encoding a first transmitted first message associated with a low-latency RA procedure, the first message comprising a PRACH preamble and a message portion.

In Example 21, the subject matter of Example 20 optionally includes wherein the processing circuit is configured to: provide an indication to the serving eNodeB to select the low latency RA procedure.

In Example 22, the subject matter of Example 21 optionally includes, wherein providing the indication to the serving eNodeB to select the low-delay RA procedure includes the processing circuit to: select a preamble from a set of PRACH preambles specified for the low-delay RA procedure code.

In Example 23, the subject matter of any one or more of Examples 21-22 optionally includes, wherein providing the indication to the serving eNodeB to select a low-latency RA procedure comprises the processing circuit being configured to: select for PRACH preamble transmission time and/or frequency resources, wherein the time and/or frequency resources are dedicated to low-latency RA procedures.

In Example 24, the subject matter of Example 23 optionally includes wherein the processing circuit is configured to: receive time and/or frequency resources dedicated to PRACH preamble transmission from the serving eNodeB.

In Example 25, the subject matter of any one or more of Examples 20-24 optionally includes wherein the processing circuit is configured to: receive an indication of selection of the low-latency RA procedure from the serving eNodeB.

In Example 26, the subject matter of Example 25 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure includes the processing circuit being configured to: based on a System Information Block 2 (SIB2) or Extended SIB2 (eSIB2) The PRACH_ConfigIndex parameter in to determine the selection of the low-latency RA process.

In Example 27, the subject matter of any one or more of Examples 25-26 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure includes the processing circuit being configured to: based on system information block 2 (SIB2) or the PRACH configuration field in extended SIB2 (eSIB2) to determine the selection of low-latency RA procedures.

In Example 28, the subject matter of any one or more of Examples 25-27 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure includes the processing circuit being configured to: based on the The value of one or more reserved bits of , to determine the selection of low-latency RA procedures.

In Example 29, the subject matter of any one or more of Examples 25-28 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure includes the processing circuit being configured to: via a radio resource control signal command to receive selection of a low-latency RA process.

Example 30 is an evolved Node B (eNodeB) apparatus comprising: a memory; and a processing circuit configured to: decode a low-latency random access (RA) on an unlicensed spectrum from a user equipment (UE) ) procedure associated with the first transmission received in the first message, wherein the first message includes a Physical Random Access Channel (PRACH) preamble and a message part, wherein the message part includes a cell radio network temporary identifier (C- At least one of RNTI), buffer status report (BSR) information, UE capability, or UE identity; perform a listen-before-talk (LBT) process on one or more channels of the unlicensed spectrum; and respond to an idle channel Evaluating, encoding a second sent second message associated with a low-latency RA procedure, wherein the second message includes at least one of a random access response (RAR), or a contention resolution message, wherein the second message is transmitted via a physical The downlink control channel (PDCCH) schedule and/or the second message includes an uplink (UL) grant.

In Example 31, the subject matter of Example 30 optionally includes wherein the message portion includes a Medium Access Control (MAC) portion, the MAC portion includes a MAC message, wherein the MAC message includes a C-RNTI, BSR information, or a capability of the UE at least one of the .

In Example 32, the subject matter of Example 31 optionally includes wherein the message portion further includes a Radio Resource Control (RRC) portion, the RRC portion includes an RRC message, wherein the RRC message includes an identification of the UE.

In Example 33, the subject matter of any one or more of Examples 30-32 optionally includes wherein the message portion further includes a Common Control Channel (CCCH) subheader.

In Example 34, the subject matter of any one or more of Examples 30-33 optionally includes wherein the second message PDSCH is scrambled via one of a C-RNTI or a Random Access RNTI (RA-RNTI) The downlink control information (DCI) is used for scheduling.

In Example 35, the subject matter of any one or more of Examples 30-34 optionally includes wherein the processing circuit is configured to: provide an indication to support low-latency RA procedures via radio resource control (RRC) signaling signaling.

In Example 36, the subject matter of Example 35 optionally includes wherein the processing circuit is configured to: determine the UE's response to the low-delay PRACH procedure based on a comparison of the PRACH preamble with a set of PRACH preambles specified for the low-delay PRACH procedure choose.

In Example 37, the subject matter of Example 36 optionally includes wherein the processing circuit is configured to determine the UE's selection of the low-delay PRACH procedure based on the set of time and/or frequency resources used for the first transmission.

In Example 38, the subject matter of any one or more of Examples 36-37 optionally includes, wherein the processing circuit is configured to: allocate a corresponding frequency resource and/or code domain to each UE of the plurality of UEs, to allow multiplexing of transmissions from multiple UEs.

In Example 39, the subject matter of any one or more of Examples 35-38 optionally includes wherein the processing circuit is configured to: Delayed selection of RA procedures.

In Example 40, the subject matter of any one or more of Examples 30-39 optionally includes wherein the processing circuit is configured to: perform channel estimation based on the first subset of symbols of the PRACH preamble.

In Example 41, the subject matter of any one or more of Examples 30-40 optionally includes wherein the processing circuit is configured to: perform channel estimation based on the first subset of symbols of the PRACH preamble.

In Example 42, the subject matter of any one or more of Examples 30-41 optionally includes wherein the processing circuit is configured to: based on a PRACH preamble sent over a previously shortened Physical Uplink Control Channel (sPUCCH) subframe code to perform channel estimation.

In Example 43, the subject matter of Example 42 optionally includes wherein the processing circuit is to: decode a UL subframe for message transmission subsequent to a previous sPUCCH subframe lacking a demodulation reference signal.

In Example 44, the subject matter of any one or more of Examples 30-43 optionally includes, wherein the processing circuit is to revert to a legacy RA procedure in response to the message portion of the first message being erroneously detected.

Example 45 is at least one machine-readable medium comprising instructions for performing a Physical Random Access Channel (PRACH) procedure in an unlicensed spectrum, the instructions, when executed by a machine, cause the machine to perform the following operations: in one or more of the unlicensed spectrum performing a listen-before-talk (LBT) procedure on a plurality of channels; encoding a first transmitted first message associated with a low-latency random access (RA) procedure on an unlicensed spectrum in response to a clear channel assessment (CCA), Wherein, the first message includes at least one of a PRACH preamble and a message part, wherein the message part includes a Cell Radio Network Temporary Identifier (C-RNTI), Buffer Status Report (BSR) information, UE capability, or UE identity at least one of; and in response to receiving an uplink (UL) grant based on a low-latency RA procedure, encoding UL data for transmission.

In Example 46, the subject matter of Example 45 optionally includes wherein the message portion includes a Medium Access Control (MAC) portion, the MAC portion includes a MAC message, wherein the MAC message includes a C-RNTI, BSR information, or a capability of the UE at least one of the .

In Example 47, the subject matter of Example 46 optionally includes wherein the MAC message further includes an identification of the UE.

In Example 48, the subject matter of any one or more of Examples 46-47 optionally includes wherein the message portion further includes a radio resource control (RRC) portion, the RRC portion includes an RRC message, wherein the RRC message includes the UE's logo.

In Example 49, the subject matter of any one or more of Examples 46-48 optionally includes wherein the capabilities of the UE include one of layer 1 UE capabilities, or MAC UE capabilities.

In Example 50, the subject matter of any one or more of Examples 45-49 optionally includes wherein the message portion further includes a Common Control Channel (CCCH) subheader.

In Example 51, the subject matter of Example 50 optionally includes instructions, when executed by a machine, causing the machine to, in response to not receiving a UL grant based on the first transmission within a predetermined length of time after the first transmission, upon non-grant A second message to be sent is coded on a frequency spectrum, where the second message includes a second PRACH preamble and a message part.

In Example 52, the subject matter of Example 51 optionally includes wherein the predetermined length of time is based on one of an absolute time, a count of valid downlink subframes, or a MAC contention resolution timer.

In Example 53, the subject matter of any one or more of Examples 45-52 optionally includes wherein the first transmission uses a shortened Physical Uplink Control Channel (sPUCCH) waveform, wherein the first portion includes a PRACH preamble , and the remainder includes the message part.

In Example 54, the subject matter of Example 53 optionally includes wherein the first portion includes the first two symbols of Message 3 , and wherein the remaining portion includes the next two symbols after the first two symbols of Message 3 .

In Example 55, the subject matter of any one or more of Examples 45-54 optionally includes instructions that, when executed by a machine, cause the machine to decode a low-latency A second message received in a second transmission associated with the RA procedure, wherein the second message includes a Physical Downlink Shared Channel (PDSCH) transmission, the PDSCH transmission includes a UL grant and includes a random access response or a contention resolution message at least one of the .

In Example 56, the subject matter of Example 55 optionally includes wherein the downlink control information (DCI) used to schedule the second message is received via one of a C-RNTI, or a random access RNTI (RA-RNTI) scrambling.

In Example 57, the subject matter of any one or more of Examples 45-56 optionally includes wherein the first message is encoded based on receiving an indication that the serving evolved NodeB (eNodeB) supports low-latency RA procedures.

In Example 58, the subject matter of Example 57 optionally includes instructions that, when executed by a machine, cause the machine to indicate to the eNodeB the need for Selection of low latency RA process.

Example 59 is at least one machine-readable medium comprising instructions for performing a Physical Random Access Channel (PRACH) procedure in an unlicensed spectrum, the instructions, when executed by a machine, cause the machine to: receive a serving eNodeB ( The eNodeB) supports an indication of a low-latency random access (RA) procedure and a legacy RA procedure; and encodes a first transmitted first message associated with the low-latency RA procedure, the first message including a PRACH preamble and a message portion.

In Example 60, the subject matter of Example 59 optionally includes instructions, when executed by the machine, causing the machine to provide an indication to the serving eNodeB to select the low latency RA procedure.

In Example 61, the subject matter of Example 60 optionally includes, wherein providing the indication to the serving eNodeB to select the low-latency RA procedure includes instructions that, when executed by a machine, cause the machine to preamble from the set of PRACHs specified for the low-latency RA procedure Select Preamble in Code.

In Example 62, the subject matter of any one or more of Examples 60-61 optionally includes, wherein providing the indication to the serving eNodeB to select a low-latency RA procedure includes instructions that, when executed by a machine, cause the machine to select a procedure for Time and/or frequency resources for PRACH preamble transmission, wherein the time and/or frequency resources are dedicated to low-delay RA procedures.

In Example 63, the subject matter of Example 62 optionally includes instructions that, when executed by the machine, cause the machine to receive time and/or frequency resources dedicated to PRACH preamble transmission from the serving eNodeB.

In Example 64, the subject matter of any one or more of Examples 59-63 optionally includes instructions that, when executed by the machine, cause the machine to receive an indication of selection of the low latency RA procedure from the serving eNodeB.

In Example 65, the subject matter of Example 64 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure comprises instructions that, when executed by a machine, cause the machine to, based on a System Information Block 2 (SIB2) or extended The PRACH_ConfigIndex parameter in SIB2 (eSIB2) is used to determine the selection of the low-latency RA process.

In Example 66, the subject matter of any one or more of Examples 64-65 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure comprises instructions that, when executed by a machine, cause the machine to, based on The PRACH Configuration field in System Information Block 2 (SIB2) or Extended SIB2 (eSIB2) to determine the selection of low-latency RA procedures.

In Example 67, the subject matter of any one or more of Examples 64-66 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure comprises instructions that, when executed by a machine, cause the machine to, based on The value of one or more reserved bits in the main information block to determine the selection of low-latency RA procedures.

In Example 68, the subject matter of any one or more of Examples 59-67 optionally includes, wherein receiving from the serving eNodeB an indication of selection of a low-latency RA procedure comprises instructions that, when executed by a machine, cause the machine to via Radio resource control signaling to receive selection of low-latency RA procedures.

Example 69 is at least one machine-readable medium comprising instructions for performing a Physical Random Access Channel (PRACH) procedure in an unlicensed spectrum, the instructions, when executed by a machine, cause the machine to: decode a message from a user equipment (UE) ), wherein the first message comprises a PRACH preamble and a message part, wherein the message part comprises At least one of Cell Radio Network Temporary Identifier (C-RNTI), Buffer Status Report (BSR) information, UE capabilities, or UE identity; perform Listen Before Talk ( LBT) procedure; and in response to the clear channel assessment, encoding a second sent second message associated with the low-delay RA procedure, wherein the second message includes at least one of a random access response (RAR), or a contention resolution message One, wherein the second message is scheduled via a physical downlink control channel (PDCCH) and/or includes an uplink (UL) grant.

In Example 70, the subject matter of Example 69 optionally includes wherein the message portion includes a Medium Access Control (MAC) portion, the MAC portion includes a MAC message, wherein the MAC message includes a C-RNTI, BSR information, or a capability of the UE at least one of the .

In Example 71, the subject matter of Example 70 optionally includes wherein the message portion further includes a Radio Resource Control (RRC) portion, the RRC portion includes an RRC message, wherein the RRC message includes an identification of the UE.

In Example 72, the subject matter of any one or more of Examples 69-71 optionally includes wherein the message portion further includes a Common Control Channel (CCCH) subheader.

In Example 73, the subject matter of any one or more of Examples 69-72 optionally includes that the second message PDSCH is via a downlink scrambled by one of a C-RNTI or a Random Access RNTI (RA-RNTI) Link Control Information (DCI) to schedule.

In Example 74, the subject matter of any one or more of Examples 69-73 optionally includes instructions, when executed by the machine, causing the machine to provide support for low-latency RA via radio resource control (RRC) signaling Process indication signaling.

In Example 75, the subject matter of Example 74 optionally includes instructions that, when executed by a machine, cause the machine to determine that the UE is sensitive to low delay based on a comparison of the PRACH preamble with a set of PRACH preambles specified for low delay PRACH procedures Selection of the PRACH process.

In Example 76, the subject matter of Example 75 optionally includes instructions, when executed by a machine, causing the machine to determine the UE's selection of a low-latency PRACH procedure based on a set of time and/or frequency resources for the first transmission .

In Example 77, the subject matter of any one or more of Examples 74-76 optionally includes instructions that, when executed by a machine, cause the machine to perform an operation based on one or more bits in a master information block or a system information block Indicates selection of a low-latency RA procedure.

Example 78 is an apparatus comprising: means for performing a listen-before-talk (LBT) procedure on one or more channels of an unlicensed spectrum; Means for spectrally encoding a first transmitted first message associated with a low-delay random access (RA) procedure, wherein the first message includes at least one of a PRACH preamble and a message portion, wherein the message portion includes a cell radio At least one of Network Temporary Identifier (C-RNTI), Buffer Status Report (BSR) information, UE capability, and/or UE identity; and for receiving an uplink (UL ) authorization to encode UL data for transmission.

In Example 79, the subject matter of Example 78 optionally includes wherein the message portion includes a Medium Access Control (MAC) portion, the MAC portion includes a MAC message, wherein the MAC message includes a C-RNTI, BSR information, or a capability of the UE at least one of the .

In Example 80, the subject matter of Example 79 optionally includes wherein the MAC message further includes an identification of the UE.

In Example 81, the subject matter of any one or more of Examples 79-80 optionally includes wherein the message portion further includes a radio resource control (RRC) portion, the RRC portion includes an RRC message, wherein the RRC message includes the UE's logo.

In Example 82, the subject matter of any one or more of Examples 79-81 optionally includes wherein the capabilities of the UE comprise one of layer 1 UE capabilities, or MAC UE capabilities.

In Example 83, the subject matter of any one or more of Examples 78-82 optionally includes wherein the message portion further includes a Common Control Channel (CCCH) subheader.

In Example 84, the subject matter of Example 83 optionally includes encoding the second transmission on the unlicensed spectrum in response to not receiving a UL grant based on the first transmission within a predetermined length of time after the first transmission. An apparatus for two messages, wherein the second message includes a second PRACH preamble and a message part.

In Example 85, the subject matter of Example 84 optionally includes wherein the predetermined length of time is based on one of an absolute time, a count of valid downlink subframes, or a MAC contention resolution timer.

In Example 86, the subject matter of any one or more of Examples 78-85, optionally comprising, wherein the first transmission uses a shortened physical uplink control channel (sPUCCH) waveform, wherein the first portion includes a PRACH preamble , and the remainder includes the message part.

In Example 87, the subject matter of Example 86 optionally includes wherein the first portion includes the first two symbols of message 3, and wherein the remaining portion includes the next two symbols after the first two symbols of message 3.

In Example 88, the subject matter of any one or more of Examples 78-87 optionally includes decoding a second transmission associated with a low-delay RA procedure scheduled via a Physical Downlink Control Channel (PDCCH) The apparatus for the second message received in the present invention, wherein the second message includes a physical downlink shared channel (PDSCH) transmission, the PDSCH transmission includes a UL grant and includes at least one of a random access response or a contention resolution message.

In Example 89, the subject matter of Example 88 optionally includes wherein the downlink control information (DCI) used to schedule the second message is received via one of a C-RNTI, or a random access RNTI (RA-RNTI) scrambling.

In Example 90, the subject matter of any one or more of Examples 78-89 optionally includes wherein the first message is encoded based on receiving an indication that the serving evolved NodeB (eNodeB) supports low-latency RA procedures.

In Example 91, the subject matter of Example 90 optionally includes means for indicating to the eNodeB selection of a low-delay RA procedure based on selecting time and/or frequency resources dedicated to PRACH preamble transmission for the low-delay RA procedure .

Example 92 is an apparatus comprising: means for receiving an indication that a serving evolved NodeB (eNodeB) supports low-delay random access (RA) procedures and legacy RA procedures; and encoding associated with the low-delay RA procedures A first connected means for sending a first message, where the first message includes a PRACH preamble and a message part.

In Example 93, the subject matter of Example 92 optionally includes means for providing an indication to the serving eNodeB to select the low-latency RA procedure.

In Example 94, the subject matter of Example 93 optionally includes wherein the means for providing an indication to the serving eNodeB to select a low-delay RA procedure further comprises, for selecting from the set of PRACH preambles specified for the low-delay RA procedure Select the device for the preamble.

In Example 95, the subject matter of any one or more of Examples 93-94 optionally includes wherein the means for providing an indication to the serving eNodeB of selecting a low-delay RA procedure further includes selecting an RA procedure for the PRACH preamble An apparatus for time and/or frequency resources for code transmission, wherein the time and/or frequency resources are dedicated to a low-latency RA process.

In Example 96, the subject matter of Example 95 optionally includes means for receiving time and/or frequency resources for PRACH preamble transmission from the serving eNodeB.

In Example 97, the subject matter of any one or more of Examples 92-96 optionally includes means for receiving an indication of selection of a low-latency RA procedure from the serving eNodeB.

In Example 98, the subject matter of Example 97 optionally includes wherein the means for receiving from the serving eNodeB an indication of the selection of a low-latency RA procedure further comprises, for based on system information block 2 (SIB2) or extended SIB2( The PRACH_ConfigIndex parameter in eSIB2) is used to determine the means for selecting the low-latency RA process.

In Example 99, the subject matter of any one or more of Examples 97-98 optionally includes, wherein the means for receiving from the serving eNodeB an indication of selection of a low-latency RA procedure further includes, based on system information means for determining the selection of a low-latency RA procedure using the PRACH configuration field in block 2 (SIB2) or extended SIB2 (eSIB2).

In Example 100, the subject matter of any one or more of Examples 97-99 optionally includes, wherein the means for receiving from the serving eNodeB an indication of the selection of a low-latency RA procedure further includes, based on the master information Means that the value of one or more reserved bits in the block is used to determine the selection of the low-latency RA process.

In Example 101, the subject matter of any one or more of Examples 92-100 optionally includes, wherein the means for receiving from the serving eNodeB an indication of the selection of a low-latency RA procedure further includes, via the radio resource Control signaling to receive means for selecting a low-latency RA procedure.

Example 102 is an apparatus comprising: for decoding a first message received from a user equipment (UE) in a first transmission associated with a low-latency random access (RA) procedure on an unlicensed spectrum The apparatus, wherein the first message includes a PRACH preamble and a message part, wherein the message part includes a Cell Radio Network Temporary Identifier (C-RNTI), buffer status report (BSR) information, UE capability, or UE identity at least one of; means for performing a listen-before-talk (LBT) procedure on one or more channels of the unlicensed spectrum; and for encoding a second transmission associated with the low-delay RA procedure in response to the clear channel assessment An apparatus for a second message, wherein the second message includes at least one of a random access response (RAR) or a contention resolution message, wherein the second message is scheduled and/or via a Physical Downlink Control Channel (PDCCH) Includes uplink (UL) grants.

In Example 103, the subject matter of Example 102 optionally includes wherein the message portion includes a Medium Access Control (MAC) portion, the MAC portion includes a MAC message, wherein the MAC message includes a C-RNTI, BSR information, or a capability of the UE at least one of the .

In Example 104, the subject matter of Example 103 optionally includes wherein the message portion further includes a radio resource control (RRC) portion, the RRC portion includes an RRC message, wherein the RRC message includes an identification of the UE.

In Example 105, the subject matter of any one or more of Examples 102-104 optionally includes wherein the message portion further includes a Common Control Channel (CCCH) subheader.

In Example 106, the subject matter of any one or more of Examples 102-105 optionally includes that the second message PDSCH is via a downlink Link Control Information (DCI) to schedule.

In Example 107, the subject matter of any one or more of Examples 102-106 optionally includes means for providing indication signaling to support low-latency RA procedures via radio resource control (RRC) signaling.

In Example 108, the subject matter of Example 107 optionally includes means for determining the UE's selection of the low-delay RA procedure based on a comparison of the PRACH preamble with a set of PRACH preambles specified for the low-delay RA procedure.

In Example 109, the subject matter of Example 108 optionally includes means for determining the UE's selection of the low-delay PRACH procedure based on the set of time and/or frequency resources used for the first transmission.

In Example 110, the subject matter of any one or more of Examples 107-109 optionally includes indicating selection of a low-latency RA procedure based on one or more bits in a master information block or a system information block installation.

The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments that may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, examples that include elements shown or described are also contemplated. In addition, with respect to the specific example (or one or more aspects thereof) shown or described herein, or to other examples (or one or more aspects thereof) shown or described herein, it is also contemplated that the use of those shown or described Examples of any combination or permutation of elements (or one or more aspects thereof) of .

Publications, patents, and patent documents mentioned in this document are hereby incorporated by reference in their entirety as if each were incorporated by reference. If there are inconsistent usages between those documents incorporated by reference and this document, the usage in the reference(s) incorporated by reference is in addition to the usage in this document; for incompatible For inconsistencies, the usage in this document shall prevail.

In this document, as is common in patent documents, the term "a" or "an" is used to include one or more, independently of any other instance or use of "at least one" or "one or more" . In this document, unless otherwise indicated, the term "or" is used to denote a non-exclusive or, i.e. "A or B" includes "A and not B", "B and not A", and "A and B ". In the appended claims, the terms "comprising" and "wherein" are used as the plain-English equivalents of the respective terms "comprising" and "wherein". Furthermore, in the appended claims, the terms "comprising" and "comprising" are open-ended, meaning that a system, device, article, or process that includes elements other than those listed after such term is still to be considered considered to fall within the scope of protection of the claims. Furthermore, in the appended claims, the terms "first", "second", and "third", etc. are used only as labels and are not intended to imply a numerical ordering of their objects.

The foregoing description is intended to be illustrative, not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in combination with each other. After reading the above description, other embodiments can be used by those of ordinary skill in the art. The abstract is intended to enable the reader to quickly ascertain the nature of the technical disclosure, for example, to comply with 37 C.F.R §1.72(b) in the US. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, in the foregoing Detailed Description, various features may be grouped together to simplify the disclosure. However, not every feature disclosed herein is set forth by the claims, as an embodiment may characterize a subset of said features. Additionally, an embodiment may include fewer features than disclosed in a particular example. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. The scope of the embodiments disclosed herein is to be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims (25)

1. An apparatus for a user equipment (UE), the apparatus comprising: memory; and processing circuitry for: performing a listen-before-talk (LBT) procedure on one or more channels of the unlicensed spectrum; encoding a first transmitted first message associated with a low-latency random access (RA) procedure on the unlicensed spectrum in response to a clear channel assessment (CCA), wherein the first message includes a PRACH preamble and at least one of message parts, wherein the message part includes a Cell Radio Network Temporary Identifier (C-RNTI), Buffer Status Report (BSR) information, capabilities of the UE, and/or an identity of the UE at least one; and In response to receiving an uplink (UL) grant based on the low-latency RA procedure, UL data is encoded for transmission. 2. The apparatus of claim 1 , wherein the message portion comprises a Medium Access Control (MAC) portion, the MAC portion comprising at least one MAC message, wherein the MAC message comprises the C-RNTI, the at least one of the BSR information, or the capability of the UE. 3. The apparatus of claim 2, wherein the MAC message further includes an identity of the UE. 4. The apparatus of claim 2, wherein the message portion further comprises a radio resource control (RRC) portion, the RRC portion comprising an RRC message, wherein the RRC message comprises an identity of the UE. 5. The apparatus of claim 2, wherein the UE capabilities comprise one of layer 1 UE capabilities, or MAC UE capabilities. 6. The apparatus of claims 1-5, wherein the message portion further comprises a Common Control Channel (CCCH) subheader. 7. The apparatus of claims 1-5, wherein the processing circuit is configured to respond to the UL grant based on the first transmission not being received within a predetermined length of time after the first transmission , Encoding a second sent second message on the unlicensed frequency spectrum, where the second message includes a second PRACH preamble and the message part. 8. The apparatus of claim 7, wherein the predetermined length of time is based on one of an absolute time, a count of valid downlink subframes, or a MAC contention resolution timer. 9. The apparatus of claim 1, wherein the first transmission uses a shortened physical uplink control channel (sPUCCH) waveform, wherein a first portion comprises the PRACH preamble and a remaining portion comprises the message part. 10. The apparatus of claim 9, wherein the first portion comprises the first two symbols of message 3, and wherein the remaining portion comprises the next two symbols following the first two symbols of message 3. symbols. 11. The apparatus of claim 1 , wherein the first sending comprises sending the PRACH preamble over one or more symbols of a first shortened physical uplink control channel (sPUCCH) subframe and sending the PRACH preamble over one or more symbols of a first shortened physical uplink control channel (sPUCCH) subframe. The message part is sent in two sPUCCH subframes. 12. The apparatus of claim 1, wherein the processing circuit is configured to decode a second transmission associated with the low-latency RA procedure scheduled via a Physical Downlink Control Channel (PDCCH) A second message, wherein the second message includes a physical downlink shared channel (PDSCH) transmission that includes the UL grant and that includes at least one of a random access response or a contention resolution message. 13. The apparatus of claim 12, wherein downlink control information (DCI) for scheduling the second message is received via one of the C-RNTI or a random access RNTI (RA-RNTI) scrambling. 14. An apparatus for an evolved Node B (eNodeB), the apparatus comprising: memory; and processing circuitry for: decoding a first message received from a user equipment (UE) in a first transmission associated with a low-latency random access (RA) procedure on an unlicensed spectrum, wherein the first message includes a physical random access a channel (PRACH) preamble and a message part, wherein the message part includes a Cell Radio Network Temporary Identifier (C-RNTI), buffer status report (BSR) information, capabilities of the UE, or an identity of the UE at least one of performing a listen-before-talk (LBT) procedure on one or more channels of the unlicensed spectrum; and encoding a second sent second message associated with the low-delay RA procedure in response to the clear channel assessment, wherein the second message includes at least one of a random access response (RAR) or a contention resolution message, Wherein, the second message is scheduled via a Physical Downlink Control Channel (PDCCH) and/or the second message includes an uplink (UL) grant. 15. The apparatus of claim 14, wherein the processing circuit is configured to provide indication signaling for supporting low-latency RA procedures through radio resource control (RRC) signaling. 16. The apparatus of claim 15, wherein the processing circuit is configured to determine that the UE pair The selection of the low-latency PRACH procedure. 17. The apparatus according to claim 16, wherein the processing circuit is configured to determine the UE's response to the low-latency PRACH procedure based on a set of time and/or frequency resources used for the first transmission s Choice. 18. The apparatus according to claim 16, wherein the processing circuit is configured to: allocate corresponding frequency resources and/or code domains to each of a plurality of UEs to allow transmission from the plurality of UEs for multiplexing. 19. At least one machine-readable medium comprising instructions for performing a Physical Random Access Channel (PRACH) procedure in an unlicensed spectrum, the instructions, when executed by a machine, cause the machine to: receiving an indication that the serving evolved Node B (eNodeB) supports low-latency random access (RA) procedures and legacy RA procedures; and Encoding a first transmitted first message associated with the low-latency RA procedure, the first message comprising a PRACH preamble and a message portion. 20. The at least one machine-readable medium of claim 19, further comprising instructions that, when executed by a machine, cause the machine to provide an indication to the serving eNodeB to select the low-latency RA procedure. 21. The at least one machine-readable medium of claim 20, wherein providing an indication to the serving eNodeB to select the low-latency RA procedure comprises instructions that, when executed by a machine, cause the machine to proceed from the A preamble is selected from a set of PRACH preambles specified by the low-delay RA process. 22. The at least one machine-readable medium of claim 20, wherein providing an indication to the serving eNodeB to select the low-latency RA procedure comprises instructions that, when executed by a machine, cause the machine to select an RA procedure with Time and/or frequency resources for PRACH preamble transmission, wherein the time and/or frequency resources are dedicated to the low-delay RA process. 23. The at least one machine-readable medium of claim 19 , further comprising instructions that, when executed by a machine, cause the machine to receive an indication of selection of the low-latency RA procedure from the serving eNodeB . 24. The at least one machine-readable medium of claim 23, wherein receiving an indication from the serving eNodeB of selection of the low-latency RA procedure comprises instructions that, when executed by a machine, cause the The machine determines the selection of the low-latency RA procedure based on the PRACH_ConfigIndex parameter in System Information Block 2 (SIB2) or Extended SIB2 (eSIB2). 25. The at least one machine-readable medium of claim 23, wherein receiving an indication from the serving eNodeB of selection of the low-latency RA procedure comprises instructions that, when executed by a machine, cause the The machine determines the selection of the low-latency RA procedure based on a PRACH configuration field in a system information block 2 (SIB2) or an extended SIB2 (eSIB2).