Patent Description:
MediaTek Inc. , R1-<NUM> relates to RACH procedure in coverage enhancement mode and PRACH resource design. MediaTek, Inc. , R1-<NUM> relates to PDCCH for SIB and other common channels transmission. 3GPP TS <NUM> V15. <NUM> relates to the NR MAC protocol.

Aspects of the invention are provided in the claims.

A user equipment (UE) may transmit a random access channel (RACH) message to a base station as part of a RACH procedure to initiate communication. The base station may respond with a second RACH message (e.g., msg2, msgB) that includes control information on a physical downlink control channel (PDCCH). However, if UE coverage is poor for certain frequencies (e.g., millimeter Wave <NUM>) or if a signal for the first RACH message is weak, the base station may be limited in how to boost transmission of the second RACH message to improve coverage. The PDCCH may present a power bottleneck for RACH messages. In one or more examples, the base station is only able to use two or three symbols in the PDCCH because the PDCCH is limited to a core set of resources (CORESET) and thus transmit power increases are limited to the two or three symbols.

To increase coverage and to improve reception of the second RACH message, the UE may monitor for the second RACH message in time and frequency resources that are not limited to the two or three symbols in the PDCCH. Receiving the second RACH message across a greater number of symbols (e.g., more than three symbols) improves reception of the RACH message. According to various aspects described herein, the UE may monitor for and receive the second RACH message in time and frequency resources outside the PDCCH, or resources that are an alternative to resources that include the PDCCH (resources in downlink control information (DCI) in the PDCCH). The resources for the UE to monitor for the second RACH message may be based at least in part on the transmission of the first RACH message absent DCI. That is, the resources for the second message are based at least in part on the first RACH message, DCI is not used to schedule the second RACH message, and the second RACH message is not received in DCI. This provides for improved coverage for the second RACH message, because the UE may receive more symbols for the second RACH message when DCI is not used.

In a RACH procedure, data for the second RACH message on a physical downlink shared channel (PDSCH) is scheduled by DCI carried in the PDCCH. Instead of scheduling the data on the PDSCH via the PDCCH, the base station may schedule the PDSCH via system information, such as in remaining minimum system information (RMSI). In other words, the UE may monitor for the second RACH message in resources that are not scheduled via DCI (e.g., resources in the PDSCH). In some aspects, the second RACH message may be scheduled via a remaining minimum system information (RMSI) message or other system information.

Resources that are not scheduled via DCI may include resources in a downlink (DL) data portion of a DL-centric slot. The DL data portion may sometimes be referred to as the payload of the DL-centric slot. The DL data portion may include the communication resources utilized to communicate DL data from a scheduling entity (e.g., UE or BS) to a subordinate entity (e.g., UE). In some examples, the DL data portion may be a PDSCH. The data portion may be considered to be outside the PDCCH. If a UE is to receive a RACH message outside of the PDCCH, in which DCI is absent, the UE may monitor for the RACH message in a set of resource candidates (e.g., symbols, subcarriers) that are located in the data portion, such as in a PDSCH rather than in the PDCCH of the control portion. For example, the UE may monitor for the RACH message in a set of resource candidates, which includes more symbols than the two or three symbols that are available for the RACH message in the control portion. The set of resource candidates may also be scheduled absent DCI, or scheduled by signaling that is not in DCI.

The wireless network <NUM> may be an LTE network, a <NUM> or NR network, and/or the like.

The BSs may also communicate with one another directly or indirectly, via a wireless or wireline backhaul.

For example, UEs <NUM> may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol or a vehicle-to-infrastructure (V2I) protocol), and/or a mesh network. In some aspects, UE <NUM> may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station <NUM>.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In <NUM> NR two initial operating bands have been identified as frequency range designations FR1 (<NUM> - <NUM>) and FR2 (<NUM> - <NUM>). It should be understood that although a portion of FR1 is greater than <NUM>, FR1 is often referred to (interchangeably) as a "Sub-<NUM>" band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a "millimeter wave" band in documents and articles, despite being different from the extremely high frequency (EHF) band (<NUM> - <NUM>) which is identified by the International Telecommunications Union (ITU) as a "millimeter wave" (mmWave) band.

As shown in <FIG>, the UE <NUM> may include a communication manager <NUM>. As described in more detail elsewhere herein, the communication manager <NUM> may transmit a first RACH message to a base station and monitor for a second RACH message from the base station in a set of resource candidates that are outside of a PDCCH based at least in part on the transmitted first RACH message. Additionally, or alternatively, the communication manager <NUM> may perform one or more other operations described herein.

Similarly, the base station <NUM> may include a communication manager <NUM>. As described in more detail elsewhere herein, the communication manager <NUM> may receive a first RACH message from a UE and transmit a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message. Additionally, or alternatively, the communication manager <NUM> may perform one or more other operations described herein.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with a RACH message without a PDCCH, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

In some aspects, UE <NUM> may include means for transmitting a first RACH message to a base station, means for monitoring for a second RACH message from the base station in a set of resource candidates that are outside of a PDCCH based at least in part on the transmitted first RACH message, means for monitoring for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information, and/or the like. Additionally, or alternatively, UE <NUM> may include means for performing one or more other operations described herein. In some aspects, such means may include communication manager <NUM>. Additionally, or alternatively, such means may include one or more components of UE <NUM> described in connection with <FIG>.

In some aspects, base station <NUM> may include means for receiving a first RACH message from a UE, means for transmitting a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message, and/or the like. Additionally, or alternatively, base station <NUM> may include means for performing one or more other operations described herein. In some aspects, such means may include the communication manager <NUM>. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

<FIG> is a diagram <NUM> showing an example of a downlink (DL)-centric slot or wireless communication structure, in accordance with various aspects of the present disclosure. The DL-centric slot may include a control portion <NUM>. Control portion <NUM> may exist in the initial or beginning portion of the DL-centric slot. Control portion <NUM> may include various scheduling information and/or control information corresponding to various portions of the DL-centric slot. In some configurations, control portion <NUM> may be a PDCCH, as indicated in <FIG>. In some aspects, control portion <NUM> may include legacy PDCCH information, shortened PDCCH (sPDCCH) information, a control format indicator (CFI) value (e.g., carried on a physical control format indicator channel (PCFICH)), one or more grants (e.g., downlink grants, uplink grants), and/or the like. Downlink control information (DCI) may be received in the PDCCH. A control resource set (CORESET) may also be limited to the PDCCH.

A UE may use a RACH procedure to synchronize with a base station and to establish a radio resource control (RRC) connection to the base station. This may give the UE the capability to transmit data to and receive data from the base station. To start the RACH procedure, the UE may transmit a first RACH message to the base station to initiate communication with the base station. The base station may, in response, transmit a second RACH message to the UE in DCI, which would be in the PDCCH, shown by control portion <NUM> of <FIG>.

The DL-centric slot may also include a DL data portion <NUM>. The DL data portion <NUM> may sometimes be referred to as the payload of the DL-centric slot. In some configurations, the DL data portion <NUM> may be a PDSCH. Data portion <NUM> may be considered to be outside the PDCCH. If a UE is to receive a RACH message outside of the PDCCH, in which DCI is absent, the UE may monitor for the RACH message in a set of resource candidates (e.g., symbols, subcarriers) that are located in data portion <NUM>, such as in a physical downlink shared channel (PDSCH), rather than in the PDCCH of control portion <NUM>. For example, the UE may monitor for second RACH message <NUM> in a set of resource candidates <NUM>, which includes more symbols than the two or three symbols that are available for the second RACH message in control portion <NUM>. The set of resource candidates <NUM> may also be scheduled absent DCI, or scheduled by signaling that is not in DCI.

The DL-centric slot may also include an uplink (UL) short burst portion <NUM>. UL short burst portion <NUM> may sometimes be referred to as an UL burst, an UL burst portion, a common UL burst, a short burst, an UL short burst, a common UL short burst, a common UL short burst portion, and/or various other suitable terms. In some aspects, UL short burst portion <NUM> may include one or more reference signals. Additionally, or alternatively, UL short burst portion <NUM> may include feedback information corresponding to various other portions of the DL-centric slot. For example, UL short burst portion <NUM> may include feedback information corresponding to control portion <NUM> and/or data portion <NUM>. Non-limiting examples of information that may be included in UL short burst portion <NUM> include an acknowledgement (ACK) signal (e.g., a physical uplink control channel (PUCCH) ACK, a physical uplink shared channel (PUSCH) ACK, an immediate ACK), a negative acknowledgement (NACK) signal (e.g., a PUCCH NACK, a PUSCH NACK, an immediate NACK), a scheduling request (SR), a buffer status report (BSR), a hybrid automatic repeat request (HARQ) indicator, a channel state indication (CSI), a CQI, a sounding reference signal (SRS), a demodulation reference signal (DMRS), PUSCH data, and/or various other suitable types of information. UL short burst portion <NUM> may include additional or alternative information, such as information pertaining to RACH procedures, scheduling requests, and various other suitable types of information.

As illustrated in <FIG>, the end of DL data portion <NUM> may be separated in time from the beginning of UL short burst portion <NUM>. The foregoing is one example of a DL-centric wireless communication structure, and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a diagram <NUM> showing an example of an UL-centric slot or wireless communication structure, in accordance with various aspects of the present disclosure. The UL-centric slot may include a control portion <NUM>. Control portion <NUM> may exist in the initial or beginning portion of the UL-centric slot. The control portion <NUM> in <FIG> may be similar to control portion <NUM> described above with reference to <FIG>. The UL-centric slot may also include an UL long burst portion <NUM>. UL long burst portion <NUM> may sometimes be referred to as the payload of the UL-centric slot. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS). In some configurations, control portion <NUM> may be a PDCCH. In some aspects, a UE may receive DCI in control portion <NUM>. If the UE is to receive a RACH message in DCI, the UE may receive the RACH message in control portion <NUM>.

As illustrated in <FIG>, the end of control portion <NUM> may be separated in time from the beginning of UL long burst portion <NUM>.

The UL-centric slot may also include an UL short burst portion <NUM>. UL short burst portion <NUM> in <FIG> may be similar to UL short burst portion <NUM> described above with reference to <FIG>, and may include any of the information described above in connection with <FIG>. The foregoing is one example of an UL-centric wireless communication structure, and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

As explained earlier, a UE may transmit a RACH message to a base station to initiate communication with the base station. The RACH message may be what the UE first transmits when the UE is powered on. The RACH message may be transmitted on a physical RACH (PRACH) and may be referred to more generally as a PRACH communication. The UE may use the RACH message to request an uplink allocation from the base station.

A first RACH message may include a PRACH sequence (also referred to as a PRACH preamble or a PRACH preamble sequence) that may be used to differentiate UEs. The UE may use a PRACH format to determine the PRACH sequence and/or transmission properties of the PRACH sequence. The UE may receive an initial RACH configuration in a transmission from the base station and use the initial RACH configuration for transmitting the first RACH message. The first RACH message may initiate a RACH procedure to obtain the uplink allocation.

<FIG> are diagrams illustrating an example <NUM> of a <NUM>-step RACH procedure and an example <NUM> of a <NUM>-step RACH procedure, respectively. In each example, a UE is performing a RACH procedure with a base station.

In LTE and NR, the <NUM>-step RACH procedure may be a RACH procedure with a four message (msg1, msg2, msg3, msg4) handshake between the UE and the base station. The UE may transmit msg1 with a PRACH preamble to the base station on a PRACH, as an example of a first RACH message. The base station may transmit msg2 to the UE on a PDCCH and a PDSCH, as an example of a second RACH message. Msg2 may include a random access response. In a <NUM>-step RACH procedure, the UE may monitor for the second RACH message (e.g., msg2) in DCI in the PDCCH. However, according to various aspects described herein, the UE may monitor for the second RACH message in a set of resource candidates that are based at least in part on transmitting the first RACH message absent DCI. That is, according to one example, the resources for the second RACH message are based at least in part on the transmitted first RACH message, DCI is not used to schedule the second RACH message, and the second RACH message is not received in DCI. In some aspects, the second RACH message may be scheduled via an RMSI message, or in other system information.

The UE may transmit msg3 on a PUSCH. Msg3 may include a contention request and device information. The base station may transmit msg4 on the PDCCH and the PDSCH. Msg4 may include a contention resolution. The contention request and contention resolution relate to resolving contention from multiple UEs that happen to use the same PRACH preamble.

In NR, the <NUM>-step RACH procedure is another RACH procedure. In the <NUM>-step procedure, a base station broadcasts system information and synchronization signal block (SSB) information to UEs. A UE may transmit a PRACH preamble as part of a msgA message to the base station, as an example of a first RACH message. MsgA may also include a payload. The base station may process the preamble, detect the preamble, and process the payload. The base station may send a response in msgB, as an example of a second RACH message. Msg1 and msg3 of the <NUM>-step RACH may be considered to be collapsed into the msgA, and msg2 and msg4 are considered to be collapsed into msgB.

In a <NUM>-step RACH procedure, the UE may monitor for the second RACH message (e.g., msgB) in DCI in the PDCCH. However, according to various aspects described herein, the UE may instead monitor for the second RACH message in a set of resource candidates that are based at least in part on the transmitted first RACH message absent DCI. That is, the resources for the second RACH message are based at least in part on the first RACH message, DCI is not used to schedule the second RACH message, and the second RACH message is not received in DCI. In some aspects, the second RACH message may be scheduled via an RMSI message, or in other system information.

As indicated above, <FIG> are provided as two examples of a RACH procedure.

A UE may transmit a first RACH message to a base station to initiate communication. The base station may respond with a second RACH message (e.g., msg2, msgB) that includes information on a PDCCH. However, if UE coverage or signal strengths are below a threshold level for certain frequencies (e.g., millimeter Wave <NUM>), the base station may be limited in how the base station can boost transmission of the second RACH message. The PDCCH may present a bottleneck for RACH messages. The base station is only able to use two or three symbols in the PDCCH because the PDCCH is limited to a CORESET and thus transmit power increases are limited to the two or three symbols.

According to various aspects described herein, the UE may monitor for and receive the second RACH message in time and frequency resources outside the PDCCH. This may be referred to as a PDCCH-less second RACH message (e.g., PDCCH-less msg2, PDCCH-less msgB) or a RACH message without a PDCCH. In one example, because DCI is included in the PDCCH, a RACH message without a PDCCH may be a RACH message without DCI. That is, the DCI may be absent from the RACH message that is without a PDCCH. By transmitting the second RACH message outside the PDCCH, the UE may have a better chance to receive the second RACH message because the UE may receive more symbols for the second RACH message (e.g., up to <NUM> symbols).

In a RACH procedure, data for the second RACH message on the PDSCH may normally be scheduled by DCI carried in the PDCCH. Instead of scheduling the data on the PDSCH via the PDCCH, the base station may schedule the PDSCH via information in the second RACH message, information in an RMSI message, other system information, and/or the like.

<FIG> illustrates an example <NUM> of a base station transmitting a RACH message without a PDCCH, in accordance with various aspects of the present disclosure. <FIG> shows a base station (BS) <NUM> (e.g., BS <NUM> depicted in <FIG> and <FIG>) and a UE <NUM> (e.g., UE <NUM> depicted in <FIG> and <FIG>) that may communicate with one another.

As shown by reference number <NUM>, UE <NUM> may transmit a first RACH message as part of a RACH procedure (e.g., <NUM>-step RACH, <NUM>-step RACH). The first RACH message may include a PRACH preamble. UE <NUM> may transmit the first RACH message in a first format that is selected from among the first format and a second format, where the first format indicates that BS <NUM> may transmit a responsive second RACH message in alternate resources outside the PDCCH, and the second format indicates that the second RACH message may be transmitted in the PDCCH, as normally expected.

In some aspects, UE <NUM> may determine to transmit the first RACH message in the first format based at least in part on a RACH type (e.g., <NUM>-step, <NUM>-step), a signal measurement, a RACH format, a set of RACH sequences (e.g., a preamble sequence subset), a RACH time resource, RACH occasions, a subset of RACH occasions, or a combination thereof. For example, UE <NUM> may be configured to use a RACH format and thus the first format may be the RACH format. UE <NUM> may receive the RACH format in a configuration message from BS <NUM>, such as in an RMSI message or in other system information. BS <NUM> may determine to instruct UE <NUM> to transmit the first RACH message in the first format based at least in part on a RACH type, a signal measurement, a RACH format, a set of RACH sequences, a preamble sequence subset, RACH occasions, or a subset of RACH occasions, a RACH time resource, or a combination thereof.

In some aspects, UE <NUM> may determine to transmit the first RACH message in the first format, rather than the second format, based at least in part on a result of a signal measurement. UE <NUM> may measure an RSRP of an SSB broadcast and determine that the RSRP does not satisfy an RSRP threshold. As a result, UE <NUM> may determine to use a first format that may trigger a responsive second RACH message that is able to use more symbols and/or more transmit power in alternative resources outside the PDCCH. The RSRP threshold may be a threshold for the PDCCH.

In some aspects, UE <NUM> may determine to transmit the first RACH message in the first format based at least in part on a RACH type or a number of RACH sequences. For example, UE <NUM> may determine that a particular RACH type, a preamble sequence subset, and/or a threshold number of RACH sequences in a PRACH preamble may be necessary to identify UE <NUM>. UE <NUM> may thus determine that the second RACH message may be better received in alternate resources outside the PDCCH.

In some aspects, UE <NUM> may determine to transmit the first RACH message in the first format based at least in part on any combination of factors discussed above. In some aspects, BS <NUM> may configure UE <NUM> with rules for selecting the first format over the second format (or any other format) and/or for monitoring the alternative resources for the second RACH message.

As shown by reference number <NUM>, BS <NUM> may receive the first RACH message and determine how to transmit the second RACH message. For example, BS <NUM> may determine to transmit the second RACH message in the alternative resources outside the PDCCH based at least in part on receiving the first RACH message in the first format. BS <NUM> may schedule the RACH message via an RMSI message or another system information message that does not involve downlink control information in a PDDCH. In some aspects, BS <NUM> may determine to transmit the second RACH message in the alternative resources based at least in part on other characteristics of the first RACH message such as a RACH type, a signal measurement, a RACH format, a set of RACH sequences, a preamble sequence subset of the first RACH message, a RACH time resource, RACH occasions, a subset of RACH occasions, or a combination thereof.

As shown by reference number <NUM>, BS <NUM> may transmit the second RACH message on the alternative resources outside of the PDCCH. These alternative resources may be part of a set of resource candidates. The set of resource candidates may be in the PDSCH. As shown by reference number <NUM>, UE <NUM> may monitor the set of resource candidates for the second RACH message, because the alternative resources may be one or more of resources in the set of resource candidates. UE <NUM> may perform blind detection on the set of resource candidates to detect on which alternative resources UE <NUM> may receive the second RACH message. UE <NUM> may also perform a cyclic redundancy check (CRC) for any data received on the alternative resources. The set of resource candidates may be based at least in part on a RACH occasion, which may be a time window for receiving a RACH message. In some aspects, UE <NUM> may receive the set of resource candidates from BS <NUM> in an RMSI message or in other system information.

UE <NUM> may normally receive control information, such as DCI, in the PDCCH for determining a location and/or schedule for receiving data on the PDSCH, but if UE <NUM> is to monitor for the second RACH message outside of the PDCCH, there may have to be another way for UE <NUM> to receive the control information. In some aspects, UE <NUM> may receive the control information in the second RACH message, an RMSI message, or in other system information.

In some aspects, an SSB may include resources that carry a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) <NUM>, and/or the like. An SSB may also be referred to as a synchronization signal and PBCH block. A UE may monitor for and/or measure SSBs using different receive (Rx) beams during an initial network access procedure. Based at least in part on the monitoring and/or measuring, the UE may indicate one or more SSBs with a best signal parameter (e.g., an RSRP parameter and/or the like) to a base station. The base station and the UE may use the one or more indicated SSBs to select one or more beams to be used for communication between the base station and the UE (e.g., for a RACH procedure and/or the like). In some aspects, UE <NUM> may determine that a PDSCH is quasi-colocated with an SSB beam and thus UE <NUM> may use SSB beam information to locate the PDSCH.

UE <NUM> may monitor and receive the second RACH message outside the PDCCH, such as in resources that are based on the first RACH message, absent DCI. The second RACH message may have been boosted by BS <NUM> to improve coverage beyond what is available in the PDCCH. UE <NUM> may proceed with and complete the RACH procedure and successfully connect to BS <NUM> without wasting resources and without adding latency.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the UE (e.g., UE <NUM> depicted in <FIG> and <FIG>, UE <NUM> depicted in <FIG>, and/or the like) performs operations associated with a RACH message without the PDCCH.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting a first RACH message to a base station (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit a first RACH message to a base station, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include monitoring for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may monitor for a second RACH message from the base station in a set of resource candidates that are outside of a PDCCH based at least in part on the transmitted first RACH message, as described above.

In a first aspect, monitoring for the second RACH message in the set of resource candidates is based at least in part on one or more of a RACH type, a preamble sequence subset of the first RACH message, RACH occasions, or a subset of RACH occasions.

In a second aspect, alone or in combination with the first aspect, process <NUM> includes receiving information identifying the set of resource candidates from the base station.

In a third aspect, alone or in combination with one or more of the first and second aspects, receiving the information identifying the set of resource candidates includes receiving the information identifying the set of resource candidates in a remaining minimum system information message or in another system information message.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, monitoring for the second RACH message includes performing blind detection on one or more resource candidates of the set of resource candidates.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process <NUM> includes determining control information for data on a physical downlink shared channel based at least in part on the second RACH message.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the set of resource candidates is based at least in part on a RACH occasion.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process <NUM> includes determining that a physical downlink shared channel is quasi-colocated with an SSB beam based at least in part on a determination that the second RACH message from the base station is outside of the PDCCH.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, monitoring for the second RACH message includes performing a CRC on one or more resource candidates of the set of resource candidates.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the base station (e.g., BS <NUM> depicted in <FIG> and <FIG>, BS <NUM> depicted in <FIG>, and/or the like) performs operations associated with a RACH message without the PDCCH.

As shown in <FIG>, in some aspects, process <NUM> may include receiving a first RACH message from a UE (block <NUM>). For example, the base station (e.g., using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive a first RACH message from a UE, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message (block <NUM>). For example, the base station (e.g., using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may transmit a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message, as described above.

In a first aspect, process <NUM> includes determining a RACH configuration that specifies that the UE is to transmit the first RACH message in a first format from among the first format and a second format based at least in part on one or more of a RACH type, a signal measurement, a RACH format, a set of RACH sequences, a RACH time resource, or a combination of two or more of the signal measurement, the RACH format, the set of RACH sequences, or the RACH time resource; and transmitting the RACH configuration to the UE.

In a second aspect, alone or in combination with the first aspect, transmitting the RACH configuration includes transmitting the RACH configuration in a remaining minimum system information message or in another system information message.

In a third aspect, alone or in combination with one or more of the first and second aspects, process <NUM> includes transmitting information identifying the set of resource candidates to the UE.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, transmitting the information identifying the set of resource candidates includes transmitting the information identifying the set of resource candidates in a remaining minimum system information message or in another system information message.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the set of resource candidates is based at least in part on a RACH occasion.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the second RACH message includes control information for data on a physical downlink shared channel.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the transmitting of the second RACH message in the set of resource candidates outside of the PDCCH is based at least in part on information in the first RACH message, where the information indicates one or more of a RACH message type, a preamble sequence subset of the first RACH message, RACH occasions, or a subset of RACH occasions.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the transmitting of the second RACH message in the set of resource candidates outside of the PDCCH is based at least in part on a determination that a signal measurement satisfies a threshold.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process <NUM> includes transmitting a RACH configuration that indicates that the second RACH message is to be transmitted in the set of resource candidates outside of the PDCCH based at least in part on a RACH type, a preamble sequence subset of the first RACH message, RACH occasions, or a subset of RACH occasions associated with the first RACH message.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the set of resource candidates are located in a PDSCH.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the second RACH message is scheduled via an RMSI message or another system information message.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication in accordance with various aspects of the present disclosure. The apparatus <NUM> may be, be similar to, include, or be included in a UE (e.g., UE <NUM> shown in <FIG>). In some aspects, the apparatus <NUM> includes a reception component <NUM>, a communication manager <NUM>, and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a client, a server, a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally, or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> may include one or more components of the first UE described above in connection with <FIG>.

The reception component <NUM> may provide means for receiving communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus <NUM>. The reception component <NUM> may provide received communications to one or more other components of the apparatus <NUM>, such as the communication manager <NUM>. In some aspects, the reception component <NUM> may provide means for signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components. In some aspects, the reception component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the first UE described above in connection with <FIG>.

The transmission component <NUM> may provide means for transmitting communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus <NUM>. In some aspects, the communication manager <NUM> may generate communications and may transmit the generated communications to the transmission component <NUM> for transmission to the apparatus <NUM>. In some aspects, the transmission component <NUM> may provide means for performing signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus <NUM>. In some aspects, the transmission component <NUM> may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the first UE described above in connection with <FIG>.

In some aspects, the communication manager <NUM> may provide means for transmitting a first RACH message to a base station, and means for monitoring for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information. In some aspects, the communication manager <NUM> may include a controller/processor, a memory, or a combination thereof, of the first UE described above in connection with <FIG>. In some aspects, the communication manager <NUM> may include the reception component <NUM>, the transmission component <NUM>, and/or the like. In some aspects, the means provided by the communication manager <NUM> may include, or be included within, means provided by the reception component <NUM>, the communication manager <NUM>, and/or the like.

In some aspects, the communication manager <NUM> and/or one or more components of the communication manager <NUM> may include or may be implemented within hardware (e.g., one or more of the circuitry described in connection with <FIG>). In some aspects, the communication manager <NUM> and/or one or more components thereof may include or may be implemented within a controller/processor, a memory, or a combination thereof, of the UE <NUM> described above in connection with <FIG>.

In some aspects, the communication manager <NUM> and/or one or more components of the communication manager <NUM> may be implemented in code (e.g., as software or firmware stored in a memory), such as the code described in connection with <FIG>. For example, the communication manager <NUM> and/or a component (or a portion of a component) of the communication manager <NUM> may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the communication manager <NUM> and/or the component. If implemented in code, the functions of the communication manager <NUM> and/or a component may be executed by a controller/processor, a memory, a scheduler, a communication unit, or a combination thereof, of the UE <NUM> described above in connection with <FIG>.

<FIG> is a diagram illustrating an example <NUM> of a hardware implementation for an apparatus <NUM> employing a processing system <NUM>. The apparatus <NUM> may be, be similar to, include, or be included in the apparatus <NUM> shown in <FIG>.

The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by a processor <NUM>, the illustrated components, and the computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, and/or the like.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatuses over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically a reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically a transmission component <NUM>, and generates a signal to be applied to the one or more antennas <NUM> based at least in part on the received information.

The processor <NUM> is coupled to the computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described herein in connection with a client. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> may include any number of additional components not illustrated in <FIG>. The components illustrated and/or not illustrated may be software modules running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware modules coupled to the processor <NUM>, or some combination thereof.

In some aspects, the processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>. In some aspects, the apparatus <NUM> for wireless communication provides means for transmitting a first RACH message to a base station, and means for monitoring for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information. The aforementioned means may be one or more of the aforementioned components of the processing system <NUM> of the apparatus <NUM> configured to perform the functions recited by the aforementioned means. As described elsewhere herein, the processing system <NUM> may include the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>. In one configuration, the aforementioned means may be the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM> configured to perform the functions and/or operations recited herein.

<FIG> is a diagram illustrating an example <NUM> of an implementation of code and circuitry for an apparatus <NUM> for wireless communication. The apparatus <NUM> may be, be similar to, include, or be included in the apparatus <NUM> shown in <FIG> and/or the apparatus <NUM> shown in <FIG>. The apparatus <NUM> may include a processing system <NUM>, which may include a bus <NUM> coupling one or more components such as, for example, a processor <NUM>, computer-readable medium / memory <NUM>, a transceiver <NUM>, and/or the like. As shown, the transceiver <NUM> may be coupled to one or more antennas <NUM>.

As further shown in <FIG>, the apparatus <NUM> may include circuitry for transmitting a first RACH message to a base station (circuitry <NUM>). For example, the apparatus <NUM> may include circuitry <NUM> to enable the apparatus <NUM> to transmit a first RACH message to a base station.

As further shown in <FIG>, the apparatus <NUM> may include circuitry for monitoring for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information (circuitry <NUM>). For example, the apparatus <NUM> may include circuitry <NUM> to enable the apparatus <NUM> to monitor for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information.

As further shown in <FIG>, the apparatus <NUM> may include, stored in computer-readable medium <NUM>, code for transmitting a first RACH message to a base station (code <NUM>). For example, the apparatus <NUM> may include code <NUM> that, when executed by the processor <NUM>, may cause the transceiver <NUM> to transmit a first RACH message to a base station.

As further shown in <FIG>, the apparatus <NUM> may include, stored in computer-readable medium <NUM>, code for monitoring for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information (code <NUM>). For example, the apparatus <NUM> may include code <NUM> that, when executed by the processor <NUM>, may cause the transceiver <NUM> to monitor for a second RACH message from the base station in a set of resource candidates that are based at least in part on the transmitted first RACH message absent downlink control information.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication in accordance with various aspects of the present disclosure. The apparatus <NUM> may be, be similar to, include, or be included in a base station (e.g., base station <NUM> shown in <FIG> and/or base station <NUM> shown in <FIG> and <FIG>). In some aspects, the apparatus <NUM> includes a reception component <NUM>, a communication manager <NUM>, and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a client, a server, a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally, or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> may include one or more components of the base station described above in connection with <FIG>.

The reception component <NUM> may provide means for receiving communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus <NUM>. The reception component <NUM> may provide received communications to one or more other components of the apparatus <NUM>, such as the communication manager <NUM>. In some aspects, the reception component <NUM> may provide means for performing signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components. In some aspects, the reception component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

The transmission component <NUM> may provide means for transmitting communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus <NUM>. In some aspects, the communication manager <NUM> may generate communications and may transmit the generated communications to the transmission component <NUM> for transmission to the apparatus <NUM>. In some aspects, the transmission component <NUM> may provide means for performing signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus <NUM>. In some aspects, the transmission component <NUM> may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

The communication manager <NUM> may provide means for receiving a first RACH message from a UE, and means for transmitting a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message. In some aspects, the communication manager <NUM> may include a controller/processor, a memory, a scheduler, a communication unit, or a combination thereof, of the base station described above in connection with <FIG>. In some aspects, the communication manager <NUM> may include the reception component <NUM>, the transmission component <NUM>, and/or the like. In some aspects, the means provided by the communication manager <NUM> may include, or be included within means provided by the reception component <NUM>, the transmission component <NUM>, and/or the like.

In some aspects, the communication manager <NUM> and/or one or more components thereof may include or may be implemented within hardware (e.g., one or more of the circuitry described in connection with <FIG>). In some aspects, the communication manager <NUM> and/or one or more components thereof may include or may be implemented within a controller/processor, a memory, or a combination thereof, of the BS <NUM> described above in connection with <FIG>.

In some aspects, the communication manager <NUM> and/or one or more components thereof may be implemented in code (e.g., as software or firmware stored in a memory), such as the code described in connection with <FIG>. For example, the communication manager <NUM> and/or a component (or a portion of a component) of the communication manager <NUM> may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the communication manager <NUM> and/or the component. If implemented in code, the functions of the communication manager <NUM> and/or a component may be executed by a controller/processor, a memory, a scheduler, a communication unit, or a combination thereof, of the BS <NUM> described above in connection with <FIG>.

The processor <NUM> is coupled to the computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described herein in connection with a server. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> may include any number of additional components not illustrated in <FIG>. The components illustrated and/or not illustrated may be software modules running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware modules coupled to the processor <NUM>, or some combination thereof.

In some aspects, the processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>. In some aspects, the apparatus <NUM> for wireless communication provides means for receiving a first RACH message from a UE, and means for transmitting a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message. The aforementioned means may be one or more of the aforementioned components of the processing system <NUM> of the apparatus <NUM> configured to perform the functions recited by the aforementioned means. As described elsewhere herein, the processing system <NUM> may include the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>. In one configuration, the aforementioned means may be the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM> configured to perform the functions and/or operations recited herein.

<FIG> is a diagram illustrating an example <NUM> of an implementation of code and circuitry for an apparatus <NUM> for wireless communication. The apparatus <NUM> may be, be similar to, include, or be included in the apparatus <NUM> shown in <FIG>, and/or the apparatus <NUM> shown in <FIG>. The apparatus <NUM> may include a processing system <NUM>, which may include a bus <NUM> coupling one or more components such as, for example, a processor <NUM>, computer-readable medium / memory <NUM>, a transceiver <NUM>, and/or the like. As shown, the transceiver <NUM> may be coupled to one or more antennas <NUM>.

As further shown in <FIG>, the apparatus <NUM> may include circuitry for receiving a first RACH message from a UE (circuitry <NUM>). For example, the apparatus <NUM> may include circuitry <NUM> to enable the apparatus <NUM> to receive a first RACH message from a UE.

As further shown in <FIG>, the apparatus <NUM> may include circuitry for receiving the update from the UE based at least in part on the federated learning configuration (circuitry <NUM>). For example, the apparatus <NUM> may include circuitry <NUM> to enable the apparatus <NUM> to receive the update from the UE based at least in part on the federated learning configuration.

As further shown in <FIG>, the apparatus <NUM> may include, stored in computer-readable medium <NUM>, code for receiving a first RACH message from a UE (code <NUM>). For example, the apparatus <NUM> may include code <NUM> that, when executed by the processor <NUM>, may cause the transceiver <NUM> to receiving a first RACH message from a UE.

As further shown in <FIG>, the apparatus <NUM> may include, stored in computer-readable medium <NUM>, code for transmitting a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message (code <NUM>). For example, the apparatus <NUM> may include code <NUM> that, when executed by the processor <NUM>, may cause the transceiver <NUM> to transmit a second RACH message in a set of resource candidates that are outside of a PDCCH based at least in part on receiving the first RACH message.

The following provides an overview of aspects of the present disclosure:.

Claim 1:
A device for wireless communication, comprising:
a memory (<NUM>); and
one or more processors (<NUM>, <NUM>, <NUM>) coupled to the memory, configured to:
transmit a first random access channel, RACH, message to a network entity; and
receive a second RACH message from the network entity in a set of resource candidates that are outside of a physical downlink control channel, PDCCH, based at least in part on the transmitted first RACH message and based on one or more of:
a signal measurement satisfying a threshold,
a RACH type,
a preamble sequence subset of the first RACH message, RACH occasions, or
a subset of RACH occasions associated with the first RACH message.