WO2023164903A1

WO2023164903A1 - Methods and apparatuses for ue power saving

Info

Publication number: WO2023164903A1
Application number: PCT/CN2022/079117
Authority: WO
Inventors: Yingying Li; Zhi YAN; Yuantao Zhang; Hongmei Liu; Haiming Wang
Original assignee: Lenovo (Beijing) Limited
Priority date: 2022-03-03
Filing date: 2022-03-03
Publication date: 2023-09-07

Abstract

Disclosed are methods and apparatuses for user equipment (UE) power saving. An embodiment of the subject application provides a UE including: a first radio frequency (RF) component and a second RF component; and a processor coupled to the first RF component and the second RF component, wherein the second RF component is configured to receive a signal indicating whether to turn off the second RF component.

Description

METHODS AND APPARATUSES FOR UE POWER SAVING

TECHNICAL FIELD

The present disclosure generally relates to wireless communications, and especially to user equipment (UE) power saving.

BACKGROUND OF THE INVENTION

Currently, low power wake-up signal (WUS) is introduced to reduce power consumption of a UE. The UE may have a main radio and a separate low power wake-up receiver. The main radio works for data transmission and reception and does not need to be kept on all the time. For example, when the data reception/transmission is completed, it can be turned off or set to deep sleep to save power. The low power wake-up receiver has the ability to monitor a wake-up signal with ultra-low power consumption. For example, when receiving the wake-up signal, it may trigger the main radio to turn on.

Therefore, the main radio is not always turned on. Certain issues such as how to turn off the main radio and how the UE aligns with the network on whether the main radio is off need to be addressed.

SUMMARY

Some embodiments of the present disclosure provide a UE including: a first radio frequency (RF) component; a second RF component; and a processor coupled to the first RF component and the second RF component, wherein the second RF component is configured to receive a signal indicating whether to turn off the second RF component.

In some embodiments, the first RF component is configured to monitor reception of information or operate according to received information when the second RF component is turned off.

In some embodiments, the signal is downlink control information (DCI) , a medium access control (MAC) control element (CE) , or a radio resource control (RRC) message.

In some embodiments, the signal is an RRC message, and the processor is configured to release or suspend an RRC connection after a first timing offset from a first start point in response to the signal.

In some embodiments, the first start point is when the second RF component receives the signal or a lower layer indicates a successful reception of the signal.

In some embodiments, the first timing offset is configured by a higher layer or pre-configured.

In some embodiments, the processor is configured to determine to turn off the second RF component after the first timing offset from the first start point in response to the signal.

In some embodiments, the RRC message is an RRC release message.

In some embodiments, the processor is configured to determine whether to turn off the second RF component after the first timing offset from the first start point based on an indication contained in the signal.

In some embodiments, the processor is configured to determine to turn off the second RF component after a second timing offset from a second start point.

In some embodiments, the second timing offset is configured in the signal or pre-configured.

In some embodiments, the second start point is when the second RF component receives the signal, when a lower layer indicates a successful reception of the signal, or when the RRC connection is released or suspended.

Some embodiments of the present disclosure provide a UE including: a first RF component; a second RF component; and a processor coupled to the first RF component and the second RF component, wherein the second RF component is configured to transmit a signal indicating that the UE is to turn off the second RF component.

In some embodiments, the processor is configured to determine to turn off the second RF component in response to that no paging is received in a time window.

In some embodiments, the time window is configured by a higher layer, pre-configured, or determined at least based on a paging cycle.

In some embodiments, the second RF component is further configured to receive random access channel (RACH) configuration (s) containing a plurality of physical RACH (PRACH) preambles and a plurality of RACH occasions (ROs) .

In some embodiments, the signal includes a sequence transmitted on one of the plurality of ROs.

In some embodiments, the sequence is a dedicated preamble configured by a higher layer from the plurality of PRACH preambles, or is different from the plurality of PRACH preambles, or is selected from a set of dedicated preambles configured by a higher layer from the plurality of PRACH preambles.

In some embodiments, the signal is transmitted on a dedicated RO configured by a higher layer which is different from the plurality of ROs.

In some embodiments, the signal is an indication transmitted in a RACH message A (MsgA) payload.

In some embodiments, the second RF component is configured to receive a random access response (RAR) message, and the processor is configured to release or suspend an RRC connection and turn off the second RF component after a first timing offset from reception of the RAR message.

In some embodiments, the first timing offset is configured in the RAR message, pre-configured, or configured by a higher layer.

In some embodiments, the second RF component is configured to receive a contention resolution message and transmit an acknowledgement (ACK) for the contention resolution message, and the processor is configured to release or suspend an RRC connection and turn off the second RF component after a second timing offset from transmission of the ACK.

In some embodiments, the second timing offset is configured in the contention resolution message, pre-configured, or configured by a higher layer.

Some embodiments of the present disclosure provide a base station (BS) including: a transmitter; a receiver; and a processor coupled to the transmitter and the receiver, wherein the transmitter is configured to transmit a signal indicating whether to turn off an RF component of a UE.

In some embodiments, the signal is DCI, a MAC CE, or an RRC message.

In some embodiments, the signal is an RRC message, and the signal further indicates the UE to release or suspend an RRC connection after a first timing offset from a first start point.

In some embodiments, the first start point is when the UE receives the signal or a lower layer of the UE indicates a successful reception of the signal.

In some embodiments, the first timing offset is configured or pre-configured to the UE.

In some embodiments, the signal indicates the UE to turn off the RF component after the first timing offset from the first start point.

In some embodiments, the RRC message is an RRC release message.

In some embodiments, the signal contains an indication indicating whether to turn off the RF component after the first timing offset from the first start point.

In some embodiments, the signal indicates the UE to turn off the RF component after a second timing offset from a second start point.

In some embodiments, the second start point is when the UE receives the signal, or when a lower layer of the UE indicates a successful reception of the signal, or when the RRC connection is released or suspended.

Some embodiments of the present disclosure provide a BS including: a transmitter; a receiver; and a processor coupled to the transmitter and the receiver, wherein the receiver is configured to receive a signal indicating that a UE is to turn off an RF component

In some embodiments, the transmitter is configured to transmit RACH configuration (s) containing a plurality of PRACH preambles and a plurality of ROs.

In some embodiments, the signal includes a sequence received on one of the plurality of ROs.

In some embodiments, the sequence is a dedicated preamble configured to the UE from the plurality of PRACH preambles, or is different from the plurality of PRACH preambles, or is selected from a set of dedicated preambles configured to the UE from the plurality of PRACH preambles.

In some embodiments, the signal is received on a dedicated RO configured to the UE which is different from the plurality of ROs.

In some embodiments, the signal is an indication received in a RACH MsgA payload.

In some embodiments, the transmitter is configured to transmit an RAR message in response to the signal such that the UE releases or suspends an RRC connection and turns off the RF component after a first timing offset from reception of the RAR message.

In some embodiments, the first timing offset is configured in the RAR message, pre-configured to the UE, or configured by a higher layer.

In some embodiments, the transmitter is configured to transmit a contention resolution message and the receiver is configured to receive an ACK for the contention resolution message from the UE such that the UE releases or suspends an RRC connection and turns off the RF component after a second timing offset from transmission of the ACK.

In some embodiments, the second timing offset is configured in the contention resolution message, pre-configured to the UE, or configured by a higher layer.

Some embodiments of the present disclosure provide a method performed by a UE which includes a first RF component and a second RF component. The method includes receiving a signal indicating whether to turn off the second RF component.

In some embodiments, the method further includes monitoring reception of information or operating according to received information by the first RF component when the second RF component is turned off.

In some embodiments, the signal is DCI, a MAC CE, or an RRC message.

In some embodiments, the signal is an RRC message, and the method further includes releasing or suspending an RRC connection after a first timing offset from a first start point in response to the signal.

In some embodiments, the method further includes determining to turn off the second RF component after the first timing offset from the first start point in response to the signal.

In some embodiments, the RRC message is an RRC release message.

In some embodiments, the method further includes determining whether to turn off the second RF component after the first timing offset from the first start point based on an indication contained in the signal.

In some embodiments, the method further includes determining to turn off the second RF component after a second timing offset from a second start point.

Some embodiments of the present disclosure provide a method performed by a UE which includes a first RF component and a second RF component. The method includes transmitting a signal indicating that the UE is to turn off the second RF component.

In some embodiments, the method further includes determining to turn off the second RF component in response to that no paging is received in a time window.

In some embodiment, the time window is configured by a higher layer, pre-configured, or determined at least based on a paging cycle.

In some embodiments, the method further includes receiving RACH configuration (s) containing a plurality of PRACH preambles and a plurality of ROs.

In some embodiments, the signal is an indication transmitted in a RACH MsgA payload.

In some embodiments, the method further includes: receiving an RAR message; and releasing or suspending an RRC connection and turning off the second RF component after a first timing offset from reception of the RAR message.

In some embodiments, the method further includes: receiving a contention resolution message; transmitting an ACK for the contention resolution message; and releasing or suspending an RRC connection and turning off the second RF component after a second timing offset from transmission of the ACK.

Some embodiments of the present disclosure provide a method performed by a BS. The method includes transmitting a signal indicating whether to turn off an RF component of a UE.

In some embodiments, the signal is DCI, a MAC CE, or an RRC message.

In some embodiments, the RRC message is an RRC release message.

Some embodiments of the present disclosure provide a method performed by a BS. The method includes receiving a signal indicating that a UE is to turn off an RF component.

In some embodiments, the method further includes transmitting RACH configuration (s) containing a plurality of PRACH preambles and a plurality of ROs.

In some embodiments, the method further includes transmitting an RAR message in response to the signal such that the UE releases or suspends an RRC connection and turns off the RF component after a first timing offset from reception of the RAR message.

In some embodiments, the method further includes transmitting a contention resolution message and receiving an ACK for the contention resolution message from the UE such that the UE releases or suspends an RRC connection and turns off the RF component after a second timing offset from transmission of the ACK.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the application can be obtained, a description of the application is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only example embodiments of the application and are not therefore to be considered limiting of its scope.

Figure 1 illustrates an exemplary RF architecture of a UE according to some embodiments of the present disclosure.

Figure 2 illustrates an exemplary mode transition between a low power mode and an RRC idle mode according to some embodiments of the present disclosure.

Figure 3 illustrates an exemplary timing sequence diagram of UE operations according to some embodiments of the present disclosure.

Figure 4 illustrates another exemplary timing sequence diagram of UE operations according to some embodiments of the present disclosure.

Figure 5 illustrates a simplified block diagram of an exemplary apparatus according to some embodiments of the present disclosure.

Figure 6 illustrates a simplified block diagram of another exemplary apparatus according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the currently preferred embodiments of the present invention, and is not intended to represent the only form in which the present invention may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present invention.

While operations are depicted in the drawings in a particular order, persons skilled in the art will readily recognize that such operations need not be performed in the particular order as shown or in a sequential order, or that all illustrated operations need be performed, to achieve desirable results; sometimes one or more operations can be skipped. Further, the drawings can schematically depict one or more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing can be advantageous.

Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as the 3rd generation partnership project (3GPP) 5G (NR) , 3GPP long-term evolution (LTE) , and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principle of the present disclosure.

When a UE is in RRC idle mode or RRC inactive mode, the UE needs to periodically wake up once per discontinuous reception (DRX) cycle, which dominates the power consumption in RRC idle mode or RRC inactive mode. A separate wake-up receiver architecture and a low power WUS may be introduced to reduce the power consumption.

Figure 1 illustrates an exemplary RF architecture of a UE according to some embodiments of the present disclosure. As shown in Figure 1, the UE may include two RF components: one can be referred to as a main radio, which may work for data or information transmission and reception; and the other can be referred to as a low power wake-up receiver, which is coupled to the main radio and has the ability to monitor reception of information (e.g., the low power WUS) with very low power consumption or operate according to received information (e.g., trigger the main radio to turn on or turn off) . The main radio may be turned off or set to deep sleep or keep in a deep sleep mode unless it is turned on. The main radio may be turned off or set to deep sleep or keep in a deep sleep mode for a long time for power saving. The low power wake-up receiver may also be referred to as a low power consumption wake-up receiver or the like. The main radio may also be referred to as a main wireless communication module, a main wireless communication device, or the like. The components in Figure 1 are intended to be illustrative, not limiting.

In some embodiments, the low power wake-up receiver may only work when the main radio is turned off. For example, when the main radio is turned off, the low power wake-up receiver monitors reception of WUS; when the low power wake-up receiver detects a WUS indicating the UE to turn on the main radio, it triggers the main radio to turn on (or wake up) . In some embodiments, the low power wake-up receiver may be also kept on when the main radio is turned on; however, the UE may ignore or stop the detection on the low power wake-up receiver. When the main radio is turned off, the low power wake-up receiver operates according to received information. For example, when the main radio is turned off and the low power wake-up receiver detects a WUS indicating the UE to turn on the main radio, it triggers the main radio to turn on (or wake up) .

Based on this RF architecture design, the UE needs to align with the BS about the state of the main radio (or whether to turn on or turn off the main radio) and the usage of the separate low power wake-up receiver.

According to some embodiments of the present disclosure, the main radio may be turned on by the UE independently from the network (e.g., a BS) , or turned on when the low power wake-up receiver receives a WUS (e.g., from a BS) indicating the UE to turn on the main radio, such as when data or information reception or transmission is needed to be performed by the UE.

According to some embodiments of the present disclosure, the main radio may be turned off (or set to be in deep sleep) by the UE independently from the network (e.g., a BS) , or turned off upon reception of a signal (e.g., from a BS) indicating the UE to turn off the main radio, such as when data or information reception or transmission is completed. In some embodiments, the signal is received by the main radio.

According to some embodiments of the present disclosure, the main radio can be turned on or turned off (or in deep sleep) when the UE is in an RRC idle mode or RRC inactive mode; it is contemplated that, when the main radio is turned off, certain operations (such as cell selection) cannot be performed, and radio resource management (RRM) measurement may be different from that performed when the main radio is kept on in the RRC idle mode or RRC inactive mode.

According to some embodiments of the present disclosure, the main radio is kept on when the UE is in the RRC idle mode or RRC inactive mode and turned off (or in deep sleep) when the UE is in a low power mode. It is contemplated that the low power mode may be referred to as other terms.

Figure 2 illustrates an exemplary mode transition between the low power mode and the RRC idle mode according to some embodiments of the present disclosure. A UE may transition from the low power mode to the RRC idle mode in response to that the UE receives a signal (e.g., a low power WUS) indicating to turn on the main radio or the UE turns on the main radio independently from the network, such as for data or information transmission or reception. The UE may transition from the RRC idle mode to the low power mode in response to that the UE receives a signal indicating to turn off the main radio or the UE turns off the main radio independently from the network, such as when there is no data or information transmission or reception for a period of time. It is contemplated that similar mode transition may occur between the low power mode and the RRC inactive mode or an RRC connected mode.

Various embodiments regarding how to turn off the main radio and how to keep alignment between the UE and the network on whether the main radio of the UE is off are described below.

According to some embodiments of the present disclosure, the network may indicate a UE whether to turn off its main radio. For example, the UE may receive a first signal (e.g., from a BS) indicating whether to turn off the main radio. The first signal can be received by the main radio. In some embodiments, the first signal may be DCI, a MAC CE, or an RRC message.

In some embodiments, the first signal is an RRC release message (e.g., an RRCRelease message as defined in the 3GPP standards) . In some embodiments, the first signal is an RRC message different from legacy or conventional RRC messages and specific to UEs with low power features (e.g., UE with low-power wake-up receiver or UE which has the capability to detect low-power WUS) . Herein, "legacy or conventional RRC messages" may refer to those RRC messages defined in the 3GPP standards prior to the present disclosure.

Upon reception of the first signal which is an RRC message, the UE may release or suspend an RRC connection after a first timing offset from a first start point in response to the first signal, as shown in Figure 3. In Figure 3, the time point t1 is the first start point, and the UE releases or suspends the RRC connection at the time point t2.

In some embodiments, the first start point (i.e., t1) is the time when the UE receives the RRC message.

In some embodiments, the first start point (i.e., t1) is the time when a lower layer of the UE indicates that the RRC message is successfully received (e.g., when the lower layer sends an ACK for the RRC message to the BS) , namely, the time when the lower layer indicates that the receipt of the RRC message has been successfully acknowledged.

In some embodiments, the first start point may be the earlier one of the time when the UE receives the RRC message and the time when the lower layer indicates that the RRC message is successfully received.

In the case that the RRC message is the RRC release message, the first timing offset between t1 and t2 may be configured by a higher layer or pre-configured. For example, the first timing offset may be 60ms as specified in the 3GPP standards for an RRC connection release procedure or may be another value depending upon e.g., the UE type or the UE capability. In the case that the RRC message is different from the legacy or conventional RRC messages, the first timing offset may be configured by a higher layer or pre-configured in the 3GPP standards. For example, the first timing offset can be configured or pre-configured to be the same as that of the RRC connection release procedure, i.e., 60ms, or a different value.

In some embodiments, the first timing offset being configured by a higher layer may refer to that: the first timing offset may be transmitted in configuration information by the BS to the UE via a higher layer signaling, e.g., an RRC signaling or a system information block (SIB) , such that the UE may receive the first timing offset from the BS.

In some embodiments, the first timing offset being pre-configured may refer to that: the first timing offset may be hard-wired into the UE or stored on a subscriber identity module (SIM) or universal subscriber identity module (USIM) card for the UE, such that the UE may obtain the first timing offset within the UE.

In some embodiments, besides releasing or suspending the RRC connection, the UE may also determine to turn off the main radio at t2 in response to receiving the RRC message. In some cases, the UE may enter the RRC idle mode or RRC inactive mode and turn off the main radio at t2. In some other cases, the UE may enter the low power mode (in which the main radio is turned off) at t2. When the main radio is turned off, certain operations (such as cell selection) cannot be performed, and RRM measurement may be different from that performed when the main radio is kept on. For example, relaxed measurement may be performed when the main radio is turned off.

In some other embodiments, the RRC message may contain a first indication for indicating the UE whether to turn off the main radio. For example, the RRC message may be an RRC release message containing the first indication. The UE may determine whether to turn off the main radio at t2 based on the first indication. When the first indication indicates the UE to turn off the main radio, the UE may both release or suspend the RRC connection and turn off the main radio at t2. In some cases, the UE may enter the RRC idle mode or RRC inactive mode and turn off the main radio at t2. In some other cases, the UE may enter the low power mode (in which the main radio is turned off) at t2. When the first indication indicates the UE not to turn off the main radio, the UE may only release or suspend the RRC connection at t2 and keep the main radio on. That is, the UE may enter the RRC idle mode or RRC inactive mode at t2 and keep the main radio on.

For example, the first indication may be "On-MainRadio. " When "On-MainRadio" is set to "true, " the UE determines not to turn off the main radio at t2. When "On-MainRadio" is set to "false, " the UE determines to turn off the main radio at t2. When the field of "On-MainRadio" is absent, the UE may apply the value of "true, " i.e., the UE may determine not to turn off the main radio at t2.

For example, the first indication may be "Off-MainRadio. " When "Off-MainRadio" is set to "true, " the UE determines to turn off the main radio at t2. When "Off-MainRadio" is set to "false, " the UE determines not to turn off the main radio at t2. When the field of "Off-MainRadio" is absent, the UE may apply the value of "false, " i.e., the UE may determine not to turn off the main radio at t2.

In some other embodiments, in response to receiving the RRC message, the UE may release or suspend the RRC connection at t2, and turn off the main radio after a second timing offset from a second start point, as shown in Figure 4. In this case, the RRC message may be an RRC release message (e.g., an RRCRelease message as defined in the 3GPP standards) or an RRC release message containing the second timing offset. In Figure 4, t1 and t2 are the same as those shown in Figure 3, the time point t3 is the second start point, and the UE releases or suspends the RRC connection at t2 and turns off the main radio at t4. Although Figure 4 shows a specific order for t1, t2, t3, and t4, it is contemplated that such an order is provided for illustration and other orders may be applied. For example, t3 may be the same time point as t1 or t2.

In some embodiments, the second start point (i.e., t3) is the time when the UE receives the RRC message.

In some embodiments, the second start point is the time when a lower layer of the UE indicates a successful reception of the RRC message (e.g., when the lower layer sends an ACK for the RRC message to the BS) .

In some embodiments, the second start point may be the earlier one of the time when the UE receives the RRC message and the time when the lower layer indicates a successful reception of the RRC message.

In some embodiments, the second start point is the time when the RRC connection is released or suspended. In this case, t3 is the same as t2.

In some embodiments, the second timing offset between t3 and t4 is configured in the first signal or pre-configured in the 3GPP standards. The second timing offset being pre-configured may refer to that: the second timing offset may be hard-wired into the UE or stored on a SIM or USIM card for the UE, such that the UE may obtain the second timing offset within the UE. In some embodiments, the second timing offset may have one value or multiple values mapped to different UE types or capabilities.

In the case that the second timing offset is set to infinite, the UE may leave the main radio on unless there are other conditions to turn it off. In the case that the second timing offset is set to zero and the second start point (i.e., t3) is the time when the RRC connection is released or suspended, the UE may turn off the main radio once it releases or suspends the RRC connection. In this case, t4 is the same as t2. It is contemplated that t4 should not be earlier than t2.

In the case that t4=t2, the UE both releases or suspends the RRC connection and turns off the main radio at t2. In some cases, the UE may enter the RRC idle mode or RRC inactive mode and turn off the main radio at t2. In some other cases, the UE may enter the low power mode (in which the main radio is turned off) at t2.

In the case that t4 is later than t2, the UE first releases or suspends the RRC connection at t2 and then turns off the main radio at t4. In some cases, the UE may enter the RRC idle mode or RRC inactive mode at t2, and turn off the main radio at t4 while staying in the RRC idle mode or RRC inactive mode. In some other cases, the UE may first enter the RRC idle mode or RRC inactive mode at t2, and then enter the low power mode at t4.

According to some embodiments of the present disclosure, a UE may determine to turn off the main radio independently from the network (e.g., a BS) and notify the network that it will turn off the main radio.

For example, when the UE receives a low power WUS (for data or information reception) on the low power wake-up receiver, the UE may turn on the main radio and monitor paging in a time window. The time window may be configured by a higher layer, pre-configured in the 3GPP standards, or determined at least based on a paging cycle. For example, the time window may be an integer multiple of the paging cycle, where the integer multiple may be configured by a higher layer or pre-configured in the 3GPP standards. If no paging is received in the time window (e.g., the UE misses the paging, or there is no paging transmitted, or the UE turns on the main radio by false detection of a low power WUS) , the UE may determine to turn off the main radio.

As another example, when the BS does not trigger the UE to turn off the main radio (e.g., when the BS does not configure the first indication as described above to indicate the UE whether to turn off the main radio in the RRC message) , the UE may determine to turn off the main radio independently.

When the UE determines to turn off the main radio independently from the network, it needs to notify the network to keep alignment between the UE and the network. In some embodiments, the UE may transmit a second signal indicating that the UE is to turn off the main radio, e.g., to the BS. For example, the second signal may be transmitted through a procedure similar to a RACH procedure.

The 3GPP NR supports two kinds of RACH procedures, i.e., 2-step RACH procedure and 4-step RACH procedure. Both types of RACH procedures support contention based random access (CBRA) and contention-free random access (CFRA) .

A BS may configure a plurality of PRACH preambles and a plurality of ROs for UEs. To perform CBRA, a UE may randomly select a PRACH preamble from the plurality of PRACH preambles and transmit the selected PRACH preamble to the BS on an RO of the plurality of ROs. It is possible that multiple UEs may select the same PRACH preamble, so contention and conflict between the multiple UEs may occur. The BS may transmit a contention resolution message to the UEs to indicate which UE succeeds in the CBRA.

To perform CFRA, a UE may be configured with a dedicated PRACH preamble (e.g., via an RA preamble assignment message) and transmit the dedicated PRACH preamble to the BS on an RO of the plurality of ROs. In response, the BS may transmit an RAR to the UE to indicate that the CFRA is successful.

In a 4-step RACH procedure, the PRACH preamble is transmitted in Msg1. In a 2-step RACH procedure, the PRACH preamble is transmitted in MsgA. MsgA has two parts: PRACH preamble transmission (MsgA preamble) and MsgA-physical uplink shared channel (PUSCH) transmission (MsgA payload) .

According to some embodiments of the present disclosure, the second signal indicating that a UE is to turn off its main radio may include a sequence transmitted on an RO.

In some embodiments, before the UE transmits the second signal, the UE may receive (e.g., by the main radio) RACH configuration (s) (e.g., from the BS) containing a plurality of PRACH preambles and a plurality of ROs. In some embodiments, the UE may use the received RACH configuration (s) for performing RACH procedures.

In some embodiments, the second signal is a sequence transmitted on one of the plurality of ROs, and the sequence is a preamble of the plurality of PRACH preambles which is configured by a higher layer and dedicated for indicating that the UE is to turn off the main radio. When the BS receives the dedicated preamble on the RO, the BS can determine that the UE is to turn off the main radio.

In some embodiments, the second signal is a sequence transmitted on one of the plurality of ROs, and the sequence is different from and orthometric to the plurality of PRACH preambles and is dedicated for indicating that the UE is to turn off the main radio. When the BS receives the dedicated sequence on the RO, the BS can determine that the UE is to turn off the main radio.

In some embodiments, the second signal is a sequence transmitted on one of the plurality of ROs, and the sequence is selected from a set of preambles that are configured by a higher layer and dedicated for indicating that the UE is to turn off the main radio. The set of preambles may be included in the plurality of PRACH preambles. When the BS receives the sequence selected from the dedicated set of preambles on the RO, the BS can determine that the UE is to turn off the main radio.

In some embodiments, the second signal is a sequence transmitted on a dedicated RO which is configured by a higher layer and is different from the plurality of ROs. The sequence may be assigned or configured to the UE by the BS or selected from a set of sequences by the UE. When the BS receives the sequence on the dedicated RO, the BS can determine that the UE is to turn off the main radio.

In some embodiments, the UE is configured to be able to perform a 2-step PRACH procedure, and the second signal may be a second indication transmitted in a RACH MsgA payload. The second indication may be a sequence. When the BS receives the RACH MsgA containing the second indication, the BS can determine that the UE is to turn off the main radio.

In the case that the second signal is a sequence assigned or configured by a higher layer dedicated for indicating that the UE is to turn off the main radio, or the second signal is an indication transmitted in a RACH MsgA payload and the preamble of the RACH MsgA is a dedicated preamble assigned or configured by a higher layer, the BS may transmit an RAR message in response to the second signal, and the UE may turn off the main radio after a third timing offset from reception of the RAR message. In some embodiments, the UE may use the dedicated preamble for performing contention-free 2-step RACH.

In some embodiments, the third timing offset may be configured in the RAR message, pre-configured in the 3GPP standards, or configured by a higher layer. For example, when the UE receives the RAR message in slot n and the third timing offset is k slot (s) , it may turn off the main radio at slot n+k, where n and k are non-negative integers.

In the case that the second signal is a sequence selected from a set of sequences, or the second signal is an indication transmitted in a RACH MsgA payload and the preamble of the RACH MsgA is selected from a set of preambles (preamble selection is same as contention-based 2-step RACH) , the BS may transmit a contention resolution message. After receiving the contention resolution message, the UE may transmit an ACK for the contention resolution message. The UE may turn off the main radio after a fourth timing offset from transmission of the ACK.

In some embodiments, the fourth timing offset is configured in the contention resolution message, pre-configured, or configured by a higher layer. For example, when the UE receives the contention resolution message in slot n and the fourth timing offset is k slot (s) , it may turn off the main radio at slot n+k, where n and k are non-negative integers.

Figure 5 illustrates a simplified block diagram of an exemplary apparatus 500 according to some embodiments of the present disclosure. The apparatus 500 may be or include at least a part of a UE, or other device with similar functionality.

As shown in Figure 5, the apparatus 500 may include a first RF component 502 (e.g., a low power wake-up receiver) , a second RF component 504 (e.g., a main radio) , and a processor 506. The second RF component 504 is coupled to the first RF component 502. The processor 506 is coupled to the first RF component 502 and the second RF component 504. It is contemplated that the apparatus 500 may include other components not shown in Figure 5.

The first RF component 502, the second RF component 504, and the processor 506 can be configured to perform any of the methods described in the present disclosure, for example, the method described with respect to any of Figures 3 and 4.

For example, the second RF component 504 may be configured to receive a signal indicating whether to turn off the second RF component 504. In some embodiments, the first RF component 502 may be configured to monitor reception of information or operate according to received information when the second RF component 504 is turned off. In some embodiments, the processor 506 may be configured to release or suspend an RRC connection after a first timing offset from a first start point in response to the signal. In some embodiments, the processor 506 may be configured to determine to turn off the second RF component 504 after the first timing offset from the first start point in response to the signal. In some other embodiments, the processor 506 may be configured to determine whether to turn off the second RF component 504 after the first timing offset from the first start point based on an indication contained in the signal. In some other embodiments, the processor 506 may be configured to determine to turn off the second RF component 504 after a second timing offset from a second start point.

As another example, the second RF component 504 may be configured to transmit a signal indicating that the apparatus 500 is to turn off the second RF component 504. In some embodiments, the first RF component 502 may be configured to monitor reception of information or operate according to received information when the second RF component 504 is turned off. In some embodiments, the processor 506 may be configured to determine to turn off the second RF component 504 in response to that no paging is received in a time window. In some embodiments, the second RF component 504 may be further configured to receive RACH configuration (s) containing a plurality of PRACH preambles and a plurality of ROs. In some embodiments, the second RF component 504 may be configured to receive an RAR message, and the processor 506 may be configured to release or suspend an RRC connection and turn off the second RF component 504 after a third timing offset from reception of the RAR message. In some other embodiments, the second RF component 504 may be configured to receive a contention resolution message and transmit an ACK for the contention resolution message, and the processor 506 may be configured to release or suspend an RRC connection and turn off the second RF component 504 after a fourth timing offset from transmission of the ACK.

Figure 6 illustrates a simplified block diagram of an exemplary apparatus 700 according to some embodiments of the present disclosure. The apparatus 700 may be or include at least a part of a BS or other device with similar functionality.

As shown in Figure 6, the apparatus 700 may include a transceiver 710 and a processor 720. The transceiver 710 may be coupled to the processor 720. In some embodiments, the transceiver 710 may include a transmitter and a receiver integrated together. In some embodiments, the transceiver 710 may include a transmitter and a receiver which are separated from each other. In some embodiments, the transceiver 710 may be a wireless transceiver.

Furthermore, the apparatus 700 may include non-transitory computer-readable medium 730 with computer-executable instructions 740 stored thereon, wherein the non-transitory computer-readable medium 730 may be coupled to the processor 720 and the transceiver 710. The computer-executable instructions 740 may be configured to be executable by the processor 720. In some embodiments, the transceiver 710, the non-transitory computer-readable medium 730, and the processor 720 may be coupled to each other via one or more local buses.

Although in Figure 6, elements such as the transceiver 710, the non-transitory computer-readable medium 730, and the processor 720 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the apparatus 700 may further include other components for actual usage.

In some embodiments, the processor 720 may be configured to cause the apparatus 700 at least to perform, with the transceiver 710, any method described above which is performed by a BS.

For example, the transceiver 710 may be configured to transmit a signal indicating whether to turn off an RF component of a UE.

As another example, the transceiver 710 may be configured to receive a signal indicating that a UE is to turn off an RF component. In some embodiments, the transceiver 710 may be configured to transmit RACH configuration (s) containing a plurality of PRACH preambles and a plurality of ROs. In some embodiments, the transceiver 710 may be configured to transmit an RAR message in response to the signal such that the UE releases or suspends an RRC connection and turns off the RF component after a third timing offset from reception of the RAR message. In some other embodiments, the transceiver 710 may be configured to transmit a contention resolution message and receive an ACK for the contention resolution message from the UE such that the UE releases or suspends an RRC connection and turns off the RF component after a fourth timing offset from transmission of the ACK.

In various example embodiments, the processor 720 may include, but is not limited to, at least one hardware processor, including at least one microprocessor such as a CPU, a portion of at least one hardware processor, and any other suitable dedicated processor such as those developed based on for example Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) . Further, the processor 720 may also include at least one other circuitry or element not shown in Figure 6.

In various example embodiments, the non-transitory computer-readable medium 730 may include at least one storage medium in various forms, such as a volatile memory and/or a non-volatile memory. The volatile memory may include, but is not limited to, for example, a RAM, a cache, and so on. The non-volatile memory may include, but is not limited to, for example, a ROM, a hard disk, a flash memory, and so on. Further, the non-transitory computer-readable medium 730 may include, but is not limited to, an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.

Further, in various example embodiments, the apparatus 700 may also include at least one other circuitry, element, and interface, for example antenna element, and the like.

In various example embodiments, the circuitries, parts, elements, and interfaces in the apparatus 700 may be coupled together via any suitable connections including, but not limited to, buses, crossbars, wiring and/or wireless lines, in any suitable ways, for example electrically, magnetically, optically, electromagnetically, and the like.

The methods of the present disclosure can be implemented on a programmed processor. However, controllers, flowcharts, and modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit such as a discrete element circuit, a programmable logic device, or the like. In general, any device that has a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.

While the present disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements shown in each figure are not necessary for operation of the disclosed embodiments. For example, one skilled in the art of the disclosed embodiments would be capable of making and using the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the present disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

The terms "includes, " "comprising, " "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more. The terms "including, " "having, " and the like, as used herein, are defined as "comprising. "

In this disclosure, relational terms such as "first, " "second, " and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Claims

A user equipment (UE) , comprising:

a first radio frequency (RF) component and a second RF component; and

a processor coupled to the first RF component and the second RF component,

wherein the second RF component is configured to receive a signal indicating whether to turn off the second RF component.
The UE of Claim 1, wherein the signal is downlink control information (DCI) , a medium access control (MAC) control element (CE) , or a radio resource control (RRC) message.
A user equipment (UE) , comprising:

a first radio frequency (RF) component and a second RF component; and

a processor coupled to the first RF component and the second RF component,

wherein the second RF component is configured to transmit a signal indicating that the UE is to turn off the second RF component.
The UE of Claim 3, wherein the processor is configured to determine to turn off the second RF component in response to that no paging is received in a time window.
The UE of Claim 4, wherein the time window is configured by a higher layer, pre-configured, or determined at least based on a paging cycle.
The UE of Claim 3, wherein the second RF component is further configured to receive random access channel (RACH) configuration (s) containing a plurality of physical RACH (PRACH) preambles and a plurality of RACH occasions (ROs) .
The UE of Claim 6, wherein the signal comprises a sequence transmitted on one of the plurality of ROs.
The UE of Claim 7, wherein the sequence is a dedicated preamble configured by a higher layer from the plurality of PRACH preambles, or is different from the plurality of PRACH preambles, or is selected from a set of dedicated preambles configured by a higher layer from the plurality of PRACH preambles.
The UE of Claim 6, wherein the signal is transmitted on a dedicated RO configured by a higher layer which is different from the plurality of ROs.
The UE of Claim 6, wherein the signal is an indication transmitted in a RACH message A (MsgA) payload.
The UE of Claim 3, wherein the second RF component is configured to receive a random access response (RAR) message, and wherein the processor is configured to release or suspend an RRC connection and turn off the second RF component after a first timing offset from reception of the RAR message.
The UE of Claim 11, wherein the first timing offset is configured in the RAR message, pre-configured, or configured by a higher layer.
The UE of Claim 3, wherein the second RF component is configured to receive a contention resolution message and transmit an acknowledgement (ACK) for the contention resolution message, and wherein the processor is configured to release or suspend an RRC connection and turn off the second RF component after a second timing offset from transmission of the ACK.
The UE of Claim 13, wherein the second timing offset is configured in the contention resolution message, pre-configured, or configured by a higher layer.
A base station (BS) , comprising:

a transmitter;

a receiver; and

a processor coupled to the transmitter and the receiver,

wherein the receiver is configured to receive a signal indicating that a user equipment (UE) is to turn off a radio frequency (RF) component.