Patent Description:
The following abbreviations are herewith defined, at least some of which are referred to within the following description: Third Generation Partnership Project ("3GPP"), Positive-Acknowledgment ("ACK"), Binary Phase Shift Keying ("BPSK"), Clear Channel Assessment ("CCA"), Cyclic Prefix ("CP"), Cyclical Redundancy Check ("CRC"), Channel State Information ("CSI"), Common Search Space ("CSS"), Discrete Fourier Transform Spread ("DFTS"), Downlink Control Information ("DCI"), Downlink ("DL"), Downlink Pilot Time Slot ("DwPTS"), Enhanced Clear Channel Assessment ("eCCA"), Enhanced Mobile Broadband ("eMBB"), Evolved Node B ("eNB"), European Telecommunications Standards Institute ("ETSI"), Frame Based Equipment ("FBE"), Frequency Division Duplex ("FDD"), Frequency Division Multiple Access ("FDMA"), Guard Period ("GP"), Hybrid Automatic Repeat Request ("HARQ"), Internet-of-Things ("IoT"), Licensed Assisted Access ("LAA"), Load Based Equipment ("LBE"), Listen-Before-Talk ("LBT"), Long Term Evolution ("LTE"), Multiple Access ("MA"), Modulation Coding Scheme ("MCS"), Machine Type Communication ("MTC"), Multiple Input Multiple Output ("MIMO"), Multi User Shared Access ("MUSA"), Narrowband ("NB"), Negative-Acknowledgment ("NACK") or ("NAK"), Next Generation Node B ("gNB"), Non-Orthogonal Multiple Access ("NOMA"), Orthogonal Frequency Division Multiplexing ("OFDM"), Primary Cell ("PCell"), Physical Broadcast Channel ("PBCH"), Physical Downlink Control Channel ("PDCCH"), Physical Downlink Shared Channel ("PDSCH"), Pattern Division Multiple Access ("PDMA"), Physical Hybrid ARQ Indicator Channel ("PHICH"), Physical Random Access Channel ("PRACH"), Physical Resource Block ("PRB"), Physical Uplink Control Channel ("PUCCH"), Physical Uplink Shared Channel ("PUSCH"), Quality of Service ("QoS"), Quadrature Phase Shift Keying ("QPSK"), Radio Resource Control ("RRC"), Random Access Procedure ("RACH"), Random Access Response ("RAR"), Radio Network Temporary Identifier ("RNTI"), Reference Signal ("RS"), Resource Spread Multiple Access ("RSMA"), Round Trip Time ("RTT"), Receive ("RX"), Sparse Code Multiple Access ("SCMA"), Scheduling Request ("SR"), Single Carrier Frequency Division Multiple Access ("SC-FDMA"), Secondary Cell ("SCell"), Shared Channel ("SCH"), Signal-to-Interference-Plus-Noise Ratio ("SINR"), System Information Block ("SIB"), Transport Block ("TB"), Transport Block Size ("TBS"), Time-Division Duplex ("TDD"), Time Division Multiplex ("TDM"), Transmission Time Interval ("TTI"), Transmit ("TX"), Uplink Control Information ("UCI"), User Entity/Equipment (Mobile Terminal) ("UE"), Uplink ("UL"), Universal Mobile Telecommunications System ("UMTS"), Uplink Pilot Time Slot ("UpPTS"), Ultra-reliability and Low-latency Communications ("URLLC"), and Worldwide Interoperability for Microwave Access ("WiMAX"). As used herein, "HARQ-ACK" may represent collectively the Positive Acknowledge ("ACK") and the Negative Acknowledge ("NACK"). ACK means that a TB is correctly received while NACK (or NAK) means a TB is erroneously received.

In certain wireless communications networks, multiple random access procedures may be triggered. In such configurations, there may not be a way to handle the multiple random access procedures.

<CIT> concerns methods to support multiple timing advance groups for multi-carrier user equipment, utilizing timing advance group synchronization information across multiple timing advance groups, and performing random access procedures in relation to timing advance groups that may not include a primary component carrier. Some embodiments utilize timing advance group indexes to enable cross-carrier random access procedure management. Other embodiments support parallel random access procedures across multiple timing advance groups. Some embodiments provide for a reference downlink component carrier for timing within a timing advance group.

<CIT> concerns a method for performing a random access procedure, comprising the steps of: generating a random access preamble to a first cell; generating a random access preamble to a second cell; determining whether the random access preamble to the first cell and the random access preamble to the second cell are triggered so as to be simultaneously transmitted in the same subframe; selecting the random access preamble to any one of the cells according to a pre-set priority when triggered so as to be simultaneously transmitted; and transmitting the any one selected random access preamble.

<CIT> method for processing a collision between a random access procedure and a measurement gap, which involves a terminal and a base station, and the terminal is configured with a measurement gap; the method includes: when the random access procedure is a contention-based random access procedure, the terminal cancels the measurement gap if a random access response window or the operating time of a contention resolution timer has an overlap with the measurement gap. The concrete solution, that the priority of the random access procedure is higher than that of the measurement gap in the method provided by the present invention, improves the reliability of the random access procedure, reduces failure probability of the random access procedure, reduces the delay of the random access procedure, and effectively utilizes a measurement gap.

<CIT> discloses a method and apparatus for handling transmission in a wireless communication system. In one embodiment, the method includes initiating a RA procedure, by a UE, in a serving cell (<NUM>). The method also includes deciding whether to transmit a RA Preamble, by the UE, in the serving cell at a specific timing during the RA procedure based on at least one information that includes beam(s) (or beam group(s)) of the serving cell detected by the UE (<NUM>).

<CIT> discloses a method for performing random access by a User Equipment (UE) in a wireless network, comprising configuring at least one UE transmit beam for a transmission of a random access signal, generating the at least one UE transmit beam using an antenna array according to the configuration, and transmitting the random access signal to a base station (BS) on the at least one UE transmit beam. An user equipment for performing random access in a wireless network, the User Equipment comprises a processing circuit configured to configure at least one UE transmit beam for a transmission of a random access signal, and generate the at least one UE transmit beam using an antenna array according to the configuration, and transmit the random access signal to the Base Station (BS) on the at least one UE transmit beam.

Apparatuses for performing multiple random access procedures are disclosed. Methods and systems also perform the functions of the apparatus.

<FIG> depicts an embodiment of a wireless communication system <NUM> for performing multiple random access procedures. In one embodiment, the wireless communication system <NUM> includes remote units <NUM> and base units <NUM>. Even though a specific number of remote units <NUM> and base units <NUM> are depicted in <FIG>, one of skill in the art will recognize that any number of remote units <NUM> and base units <NUM> may be included in the wireless communication system <NUM>.

The base units <NUM> may be distributed over a geographic region. In certain embodiments, a base unit <NUM> may also be referred to as an access point, an access terminal, a base, a base station, a Node-B, an eNB, a gNB, a Home Node-B, a relay node, a device, or by any other terminology used in the art. The base units <NUM> are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding base units <NUM>.

In one implementation, the wireless communication system <NUM> is compliant with the 3GPP protocol, wherein the base unit <NUM> transmits using an OFDM modulation scheme on the DL and the remote units <NUM> transmit on the UL using a SC-FDMA scheme or an OFDM scheme. More generally, however, the wireless communication system <NUM> may implement some other open or proprietary communication protocol, for example, WiMAX, among other protocols.

In one embodiment, a remote unit <NUM> may determine that multiple random access procedures are triggered. In some embodiments, the remote unit <NUM> may perform the multiple random access procedures in parallel (e.g., at the same time), select a prioritized random access procedure of the multiple random access procedures to perform based on a priority corresponding to the multiple random access procedures, or some combination thereof. Accordingly, a remote unit <NUM> may be used for performing multiple random access procedures.

In certain embodiments, a base unit <NUM> may receive multiple random access preambles corresponding respectively to multiple random access procedures in parallel, receive a prioritized random access preamble of the multiple random access preambles based on a priority corresponding to the multiple random access procedures, or some combination thereof. Accordingly, a base unit <NUM> may be used for performing multiple random access procedures.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for performing multiple random access procedures. The apparatus <NUM> includes one embodiment of the remote unit <NUM>. Furthermore, the remote unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. In some embodiments, the input device <NUM> and the display <NUM> are combined into a single device, such as a touchscreen. In certain embodiments, the remote unit <NUM> may not include any input device <NUM> and/or display <NUM>. In various embodiments, the remote unit <NUM> may include one or more of the processor <NUM>, the memory <NUM>, the transmitter <NUM>, and the receiver <NUM>, and may not include the input device <NUM> and/or the display <NUM>.

In various embodiments, the processor <NUM> may determine that multiple random access procedures are triggered. In some embodiments, the processor <NUM> may perform the multiple random access procedures in parallel and/or select a prioritized random access procedure of the multiple random access procedures to perform based on a priority corresponding to the multiple random access procedures. In some embodiments, the priority may be determined based on configuration from the base unit <NUM> and/or based on a specification. In one embodiment, the priority may include a ranking order of each random access procedure in which a higher ranking random access procedure has a higher priority. In some embodiments, random access procedures with a higher priority are performed before random access procedures with a lower priority.

In some embodiments, the memory <NUM> stores data relating to random access procedures.

The transmitter <NUM> is used to provide UL communication signals to the base unit <NUM> and the receiver <NUM> is used to receive DL communication signals from the base unit <NUM>.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for performing multiple random access procedures. The apparatus <NUM> includes one embodiment of the base unit <NUM>. Furthermore, the base unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. As may be appreciated, the processor <NUM>, the memory <NUM>, the input device <NUM>, the display <NUM>, the transmitter <NUM>, and the receiver <NUM> may be substantially similar to the processor <NUM>, the memory <NUM>, the input device <NUM>, the display <NUM>, the transmitter <NUM>, and the receiver <NUM> of the remote unit <NUM>, respectively.

In some embodiments, the receiver <NUM> may be used to receive multiple random access preambles corresponding respectively to multiple random access procedures in parallel and/or receive a prioritized random access preamble of the multiple random access preambles based on a priority corresponding to the multiple random access procedures. Although only one transmitter <NUM> and one receiver <NUM> are illustrated, the base unit <NUM> may have any suitable number of transmitters <NUM> and receivers <NUM>.

In some embodiments, performing multiple random access procedures may be performed by enabling only one random access procedure to performed at a time using various steps, such as the steps that follow, that may be performed in any suitable order and/or some steps may not be performed.

In a first step, a base unit <NUM> may transmit random access parameters to a remote unit <NUM> to configure the remote unit <NUM>. In various embodiments, the parameters may include information that indicates priority of certain random access procedures. In some embodiments, a random access procedure for transitioning from an inactive state (e.g., RRC_Inactive) to a connected state (e.g., RRC_Connected) may have priority over a random access procedure for on-demand system information ("SI") request. In a claimed embodiment, a random access procedure for a beam recovery request has priority over a random access procedure for an uplink synchronization. As used herein, a first random access procedure having "priority over" a second random access procedure may mean that the first random access procedure has a higher priority than the second random access procedure and/or that the first random access procedure is performed before the second random access procedure.

In a second step, a new random access procedure may be triggered during a time in which a random access procedure is being performed.

In a third step, the remote unit <NUM> may perform a random access procedure. The random access procedure that is performed may be the new random access procedure triggered in the second step, the random access procedure being performed in the second step, or another triggered random access procedure. Specifically, the remote unit <NUM> selects one of multiple triggered random access procedures to perform based on the random access parameters related to priority received by the remote unit <NUM> in the first step. In one embodiment, the selected random access procedure may be a random access procedure having the highest priority. In response to the remote unit <NUM> selecting a random access procedure to perform, the remote unit <NUM> may stop performing any unselected random access procedures and perform the selected random access procedure.

In a fourth step, the remote unit <NUM> receives a random access response from the base unit <NUM> in response to the remote unit <NUM> transmitting a preamble corresponding to the selected random access procedure. In certain embodiments, in response to the random access response received in a beam including a backoff indicator, the backoff indicator may be applied only to the random access procedure associated with the beam (e.g., the selected random access procedure).

In a fifth step, in response to random access preamble identifiers included in the random access response matching the transmitted random access preamble, the remote unit <NUM> may transmit a message indicating that a corresponding resource is allocated by the random access response.

In a sixth step, the remote unit <NUM> may receive a response from the base unit <NUM> related to the message transmitted in the fifth step.

In some embodiments, performing multiple random access procedures may be performed by enabling multiple random access procedure to performed in parallel using various steps, such as the steps that follow, that may be performed in any suitable order and/or some steps may not be performed.

In a first step, a base unit <NUM> may transmit random access parameters to a remote unit <NUM> to configure the remote unit <NUM>. In certain embodiments, the random access parameters may include a separate parameter set for different random access procedures.

In a third step, the remote unit <NUM> may perform a random access procedure. Specifically, the remote unit <NUM> may perform multiple random access procedures in parallel based on the separate pamameter sets configured in the first step.

In a fourth step, the remote unit <NUM> may receive a random access response from the base unit <NUM> in response to the remote unit <NUM> transmitting a preamble corresponding to a random access procedure. In certain embodiments, in response to the random access response received in a beam including a backoff indicator, the backoff indicator may be applied only to the random access procedure associated with the beam.

In a fifth step, in response to random access preamble identifiers included in the random access response matching the transmitted random access preamble, the remote unit <NUM> may transmit a message indicating that a corresponding resource is allocated by the random access response. For example, in response to the remote unit <NUM> receiving a random access response for handover or reestablishment, the message may include an on-demand SI request.

<FIG> is a schematic flow chart diagram illustrating one embodiment of a method <NUM> for performing multiple random access procedures. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> may include determining <NUM> that multiple random access procedures are triggered. As used herein, a random access procedure being "triggered" may mean that the random access procedure is initiated and/or started, such as in response to a threshold being reached and/or an event occurring. In some embodiments, the method <NUM> includes performing <NUM> the multiple random access procedures in parallel, selecting a prioritized random access procedure of the multiple random access procedures to perform based on a priority corresponding to the multiple random access procedures, or some combination thereof.

In one embodiment, a random access procedure for a transition from an inactive state to a connected state has priority over a random access procedure for an on-demand system information request. In a claimed embodiment, a random access procedure for a beam recovery request has priority over a random access procedure for an uplink synchronization. In certain embodiments, the method <NUM> includes selecting the prioritized random access procedure to perform based on a random access procedure for a transition from an inactive state to a connected state having priority over a random access procedure for an on-demand system information request, a random access procedure for a beam recovery request having priority over a random access procedure for an uplink synchronization, or some combination thereof. In various embodiments, the method <NUM> includes performing the prioritized random access procedure and stopping unselected random access procedures from being performed while the prioritized random access procedure is being performed. In some embodiments, the method <NUM> includes receiving a random access response in a beam. In such embodiments, the random access response includes a backoff indicator.

In certain embodiments, the backoff indicator is applied to a random access procedure associated with the beam. In some embodiments, in response to performing the multiple random access procedures in parallel, the method <NUM> includes assigning a separate parameter set for each random access procedure of the multiple random access procedures. In various embodiments, in response to performing the multiple random access procedures in parallel, the method <NUM> includes performing the multiple random access procedures in parallel based on the separate parameter set for each random access procedure.

In one embodiment, the method <NUM> includes receiving a random access response corresponding to a first random access procedure. In such an embodiment, in response to a random access preamble identifier included in the random access response matching a transmitted random access preamble, the method <NUM> includes transmitting a message including information corresponding to a second random access procedure. In certain embodiments, the method <NUM> includes receiving a random access response corresponding to a random access procedure. In such an embodiment, in response to receiving the random access response and in response to the random access procedure corresponding to a handover or reestablishment, the method <NUM> includes transmitting a message including an on-demand system information request.

<FIG> is a schematic flow chart diagram illustrating another embodiment of a method <NUM> for performing multiple random access procedures. In some embodiments, the method <NUM> is performed by an apparatus, such as the base unit <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> may include receiving <NUM> multiple random access preambles corresponding to multiple random access procedures in parallel, receiving a prioritized random access preamble of the multiple random access preambles based on a priority corresponding to the multiple random access procedures, or some combination thereof. As used herein, a "prioritized random access preamble" may refer to a random access preamble that corresponds to a random access procedure having a highest priority and/or a random access procedure that is selected by a remote unit <NUM> to be performed.

In certain embodiments, a random access procedure for a transition from an inactive state to a connected state has priority over a random access procedure for an on-demand system information request. In various embodiments, a random access procedure for a beam recovery request has priority over a random access procedure for an uplink synchronization. In some embodiments, the prioritized random access preamble is selected based on a random access procedure for a transition from an inactive state to a connected state having priority over a random access procedure for an on-demand system information request, a random access procedure for a beam recovery request having priority over a random access procedure for an uplink synchronization, or some combination thereof.

In certain embodiments, the method <NUM> includes transmitting a random access response corresponding to a first random access preamble. In some embodiments, in response to transmitting the random access response, the method <NUM> receives a message including information corresponding to a second random access preamble. In various embodiments, the method <NUM> includes transmitting a random access response corresponding to a random access preamble. In one embodiment, in response to transmitting the random access response and in response to the random access preamble corresponding to a handover or reestablishment, the method <NUM> includes receiving a message including an on-demand system information request.

Claim 1:
An apparatus (<NUM>) comprising:
a processor (<NUM>) configured to:
determine that a plurality of random access procedures is triggered; and
select a prioritized random access procedure of the plurality of random access procedures to perform based on a priority corresponding to the plurality of random access procedures;
wherein the processor (<NUM>) is configured to select the prioritized random access procedure to perform based on a random access procedure for a beam recovery request having priority over a random access procedure for an uplink synchronization, and
wherein the processor (<NUM>) is configured to perform the prioritized random access procedure for a beam recovery request and to stop unselected random access procedures from being performed while the prioritized random access procedure is being performed.