WO2023123058A1

WO2023123058A1 - Methods and apparatuses for relaxed measurement

Info

Publication number: WO2023123058A1
Application number: PCT/CN2021/142504
Authority: WO
Inventors: Yingying Li; Zhi YAN; Yuantao Zhang; Hongmei Liu; Haiming Wang
Original assignee: Lenovo (Beijing) Limited
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2023-07-06

Abstract

The present disclosure relates to methods and apparatuses for relaxed measurement. One embodiment of the present disclosure provides a user equipment (UE) including: a first radio frequency (RF) component; a second RF component coupled to the first RF component; and a processor coupled to the first RF component and the second RF component, wherein the first RF component is configured to monitor reception of a first signal indicating to wake up the second RF component, and wherein the second RF component is configured to receive information during a first time duration, or during a second time duration after receiving the first signal.

Description

METHODS AND APPARATUSES FOR RELAXED MEASUREMENT

TECHNICAL FIELD

The present disclosure relates to wireless communication, and in particular relates to methods and apparatuses for relaxed measurement.

BACKGROUND OF THE INVENTION

Currently, low power wake-up signal (WUS) is introduced to reduce power consumption of a user equipment (UE) . However, when a UE is monitoring the low power WUS, its mobility management may be impacted.

Mobility issue of a UE with low power WUS feature is one of the important aspects of low power WUS design in Rel-18. How to perform mobility management while the UE keeps monitoring the low power WUS needs to be addressed.

SUMMARY

One embodiment of the present disclosure provides a user equipment (UE) including: a first radio frequency (RF) component; a second RF component coupled to the first RF component; and a processor coupled to the first RF component and the second RF component, wherein the first RF component is configured to monitor reception of a first signal indicating to wake up the second RF component, and wherein the second RF component is configured to receive information during a first time duration, or during a second time duration after receiving the first signal.

In some embodiments, the processor is configured to determine radio resources management (RRM) measurements based on the received information.

In some embodiments, the first time duration has a periodicity equal to M1×N1×N2 discontinuous reception (DRX) cycles, and has a length equal to T DRX cycles, wherein M1 is 1 or 2, N1 is a first scaling factor associated with a length of the DRX cycle and a frequency range, N2 is a second scaling factor larger than one, and T is a positive integer; or the first time duration has a periodicity equal to N3 synchronization signal block (SSB) periodicities, and has a length equal to P SSB periodicities, wherein N3 and P are positive integers.

In some embodiments, N2 or N3 is configured by a higher layer, preconfigured, associated with a UE capability, or associated with the length of the DRX cycle.

In some embodiments, T is smaller than or equal to M1×N1.

In some embodiments, the length of the first time duration is extended to an integer multiple of T DRX cycles or to an integer multiple of P SSB periodicities when a predefined condition occurs, or is extended until a serving cell of the UE fulfils a cell selection criterion.

In some embodiments, P is configured by a higher layer, fixed, or determined at least by a periodicity of SSB-based RRM measurement timing configuration (SMTC) and the DRX cycle.

In some embodiments, the first time duration immediately follows a third time duration in which the second RF component stops information reception.

In some embodiments, the third time duration is configured by a higher layer, preconfigured, or flexibly determined by the UE.

In some embodiments, the information includes at least one of data transmission (s) , measurement signal (s) , or system information update (s) .

In some embodiments, the second time duration has a length equal to T DRX cycles, P SSB periodicities, X subframes, or Y frames, wherein T, P, X, and Y are positive integers.

In some embodiments, the second time duration immediately follows an offset from reception of the first signal, or starts from a nearest measurement occasion, a nearest measurement signal, or a nearest DRX cycle after the offset from the reception of the first signal.

In some embodiments, the second RF component is further configured to: stop receiving the information after the first time duration or the second time duration, or once a serving cell of the UE fulfils a cell selection criterion, or upon receiving a signal indicating the UE to stop information reception on the second RF component.

Another embodiment of the present disclosure provides a method performed by a UE. The method includes monitoring, by a first RF component of the UE, reception of a first signal indicating to wake up a second RF component of the UE; and receiving, by the second RF component, information during a first time duration, or during a second time duration after receiving the first signal.

In some embodiments, the method further includes determining RRM measurements based on the received information.

In some embodiments, the first time duration has a periodicity equal to M1×N1×N2 DRX cycles, and has a length equal to T DRX cycles, wherein M1 is 1 or 2, N1 is a first scaling factor associated with a length of the DRX cycle and a frequency range, N2 is a second scaling factor larger than one, and T is a positive integer; or the first time duration has a periodicity equal to N3 SSB periodicities, and has a length equal to P SSB periodicities, wherein N3 and P are positive integers.

In some embodiments, T is smaller than or equal to M1×N1.

In some embodiments, P is configured by a higher layer, fixed, or determined at least by a periodicity of SMTC and the DRX cycle.

In some embodiments, the method further includes stopping receiving the information after the first time duration or the second time duration, or once a serving cell of the UE fulfils a cell selection criterion, or upon receiving a signal indicating the UE to stop information reception on the second RF component.

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.

Fig. 1A illustrates an exemplary scenario that a UE turns on a main radio in response to a wake-up signal indicating "ON" according to some embodiments of the present disclosure.

Fig. 1B illustrates an exemplary scenario that a UE turns off a main radio in response to a wake-up signal indicating "OFF" according to some embodiments of the present disclosure.

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

Fig. 3 illustrates an example of serving cell measurement.

Fig. 4 illustrates an exemplary method for relaxed measurement according to some embodiments of the present disclosure.

Fig. 5 illustrates another exemplary method for relaxed measurement according to some embodiments of the present disclosure.

Fig. 6 illustrates another exemplary method for relaxed measurement according to some embodiments of the present disclosure.

Fig. 7 illustrates another exemplary method for relaxed measurement according to some embodiments of the present disclosure.

Fig. 8 illustrates a method performed by a UE for relaxed measurement according to some embodiments of the present disclosure.

Fig. 9 illustrates a simplified block diagram of an 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 state or RRC inactive state, the UE needs to periodically wake up once per DRX cycle, which dominates the power consumption in RRC idle state or RRC inactive state. A separate wake-up receiver architecture and a low power WUS are introduced to reduce the power consumption. For example, a 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 may monitor reception of the low power WUS. When receiving the low power WUS indicating to turn on the main radio, the low power wake-up receiver may trigger the main radio to turn on (also referred to as "to wake up" ) .

Fig. 1A illustrates an exemplary scenario that a UE turns on a main radio in response to a wake-up signal indicating "ON" according to some embodiments of the present disclosure. Fig. 1B illustrates an exemplary scenario that the UE turns off the main radio in response to a wake-up signal indicating "OFF" according to some embodiments of the present disclosure.

In Figs. 1A and 1B, the UE includes two RF components, i.e. a main radio and a low power wake-up receiver. The low power wake-up receiver operates in an always "on" manner with very low power consumption, and is configured to receive a wake-up signal (e.g., a low power WUS) . The main radio can perform data or information transmission and reception, and it 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 Figs. 1A and 1B are intended to be illustrative, not limiting.

In the scenario shown in Fig. 1A, the UE receives, by using the low power wake-up receiver, a wake-up signal indicating "ON" (marked as "Wake-up signal (ON) " in Fig. 1A) which indicates the UE to turn on the main radio. The low power wake-up receiver then triggers the main radio to turn on. As a result, the main radio is turned on and in an "ON" mode. In the "ON" mode, the main radio can perform information reception. The information may include at least one of data transmission (s) , measurement signal (s) , or system information update (s) .

In the scenario shown in Fig. 1B, the UE receives, by using the low power wake-up receiver, a wake-up signal indicating "OFF" (marked as "Wake-up signal (OFF) " in Fig. 1B) which indicates the UE to turn off the main radio. The low power wake-up receiver then transmits a signal to turn off the main radio. As a result, the main radio is turned off and goes to an "OFF" mode or "deep sleep" mode. In the "OFF" mode or "deep sleep" mode, the main radio stops information reception.

In some embodiments of the present disclosure, the main radio can be turned on or turned off in an idle mode (e.g., RRC idle state) . In some other embodiments of the present disclosure, in an idle mode, the main radio is turned on (i.e., in the "ON" mode) ; and in a low power mode, the main radio is turned off or in deep sleep (i.e., in the "OFF" mode or "deep sleep" mode) . It should be noted that the low power mode may be referred to as any other terms.

As illustrated in Figs. 1A and 1B, a UE may transition from the low power mode to the idle mode in response to receiving a wake-up signal indicating "ON, " and may transition from the idle mode to the low power mode in response to receiving a wake-up signal indicating "OFF. "

In some embodiments of the present disclosure, the wake-up signal may only indicate "ON" and never indicate "OFF" (i.e., there is no "Wake-up signal (OFF) " ) . In such embodiments, the UE may turn on the main radio upon receiving a wake-up signal, and turn off the main radio when the wake-up signal is not received for a time duration, or when the wake-up signal is received for a time duration, or other conditions occur. That is, the UE may transition from the low power mode to the idle mode in response to receiving a wake-up signal, and may transition from the idle mode to the low power mode in response to the wake-up signal not received for a time duration, or the wake-up signal received for a time duration, or other conditions.

In the examples illustrated in Figs. 1A and 1B, the main radio of the UE wakes up only when it is triggered by a wake-up signal. In this way, power consumption can be dramatically reduced. However, the behavior of the UE in the state illustrated in Fig. 1B (i.e., the main radio is in the "OFF" mode or "deep sleep" mode) may be different from that of the UE in the state illustrated in Fig. 1A (i.e., the main radio is in the "ON" mode) . For example, since the low power wake-up receiver may not be able to detect SSB, the UE in the state illustrated in Fig. 1B cannot perform RRM measurement. Therefore, the mobility management may be impacted, and the mobility issue should be resolved for the UE with low power WUS feature.

Fig. 3 illustrates an example of serving cell measurement.

A UE does not need to measure cell signals with a periodicity as the SSB and the appropriate measurement periodicity can be configured according to the channel condition. This is desirable and can help the UE to avoid unnecessary measurements and reduce the power consumption of UE. According to 3GPP specifications, an SMTC periodicity is introduced to define a measurement periodicity and timings of SSBs that a UE can use for measurements. For example, the UE may only detect SSB burst (s) in a window duration in each SMTC periodicity as measurement occasion (s) .

The SMTC periodicity can be set in the same range of SSB periodicity, e.g., 5, 10, 20, 40, 80 or 160 ms. The window duration can be set to, for example, 1, 2, 3, 4, or 5 ms, according to the number of SSBs transmitted on the cell being measured.

According to 3GPP specifications, a UE shall measure the synchronization signal based reference signal received power (SS-RSRP) and synchronization signal based reference signal received quality (SS-RSRQ) level of a serving cell and evaluate a cell selection criterion S for the serving cell at least once every M1×N1 DRX cycle (s) , where:

M1=2 if SMTC periodicity (T _SMTC) > 20 ms and DRX cycle ≤ 0.64 s,

otherwise M1=1.

The UE shall filter the SS-RSRP and SS-RSRQ measurements of the serving cell using at least 2 measurements. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least a half of the DRX cycle.

If the UE has performed measurements in N _serv consecutive DRX cycles (please refer to Table 1 below) , and the serving cell does not fulfil the cell selection criterion S, the UE shall initiate the measurements of all neighbor cells indicated by the serving cell, regardless of the measurement rules currently limiting UE measurement activities.

Table 1: N _serv

The first column of Table 1 is DRX cycle lengths in units of second. For example, the first row is for a DRX cycle of 0.32s, the second row is for a DRX cycle of 0.64s, the third row is for a DRX cycle of 1.28s, and the fourth row is for a DRX cycle of 2.56s. The scaling factor N1 is associated with frequency range (FR) . For FR1, which ranges from 450MHz to 6000MHz, N1 is 1; while for FR2, which ranges from 24250MHz to 52600MHz, N1 is associated with DRX cycle lengths, which is 8, 5, 4, and 3 for different DRX cycle lengths respectively. N _serv in units of number of DRX cycles is M1×N1×4, M1×N1×4, N1×2, and N1×2 for different DRX cycle lengths respectively.

If the UE in RRC idle state has not found any new suitable cell based on searches and measurements using the intra-frequency, inter-frequency and inter-radio access technology (RAT) information indicated in the system information for 10s, the UE shall initiate cell selection procedures for the selected public land mobile network (PLMN) .

Details of other relevant technique involved may be found in 3GPP specification documents, such as TS38.211, TS38.212, TS38.213, TS38.214, or TS38.331, etc.

Fig. 3 shows five SSB burst sets. The time duration between starts of two consecutive SSB burst sets is referred to as an SSB periodicity. A periodicity of M1×N1 DRX cycle (s) in the example shown in Fig. 3 includes four SSB burst sets. In other words, a base station transmits four SSB burst sets in a periodicity of M1×N1 DRX cycle (s) . The base station may be referred to as an access point, an access terminal, a base, a base unit, a macro cell, a Node-B, an evolved Node B (eNB) , a gNB, an ng-eNB, a home node-B, a relay node, or a device, or described using other terminology used in the art. In this example, the SMTC periodicity includes two SSB burst sets, and the window duration includes one SSB burst set. Accordingly, the UE may detect SSBs in two window durations respectively within two SMTC periodicities as measurement occasions in a periodicity of M1×N1 DRX cycle (s) .

In view of the above, measurements for the UE in an idle mode have certain requirements. The UE should perform measurements at least once every M1×N1 DRX cycle (s) and the measurement occasions are determined by the SMTC configuration. If the UE has evaluated in N _serv consecutive DRX cycles that the serving cell does not fulfil the cell selection criterion S, the UE shall initiate the measurements of neighbor cells.

When the main radio is off or in a deep sleep mode, the UE cannot wake up according to a periodicity (e.g., SMTC periodicity) to receive SSB to perform measurement to fulfil the above measurement requirements. Furthermore, measurement requirements not fulfilled may result in that the UE initiates the measurements of all neighbor cells indicated by the serving cell frequently. Therefore, relaxing measurement should be considered to address the mobility issue.

In these embodiments, the UE turns on the main radio to perform the SSB-based RRM measurement for the serving cell periodically with a periodicity larger than the periodicity of M1×N1 DRX cycle (s) as explained in Fig. 3.

The present disclosure proposes a new scaling factor, which may be referred to as "N2, " to define the periodicity. For example, as shown in Fig. 4, the periodicity is M1×N1×N2 DRX cycle (s) , where N2 is larger than one.

The value of N2 may be determined in various manners as follows:

a) The value of N2 may be configured by a higher layer.

For example, a higher layer may configure a cell specific or UE specific value of N2. In an embodiment, the higher layer may configure a single cell specific value of N2. In another embodiment, the higher layer may configure multiple cell specific values of N2, and the UE can select a value of N2 by the UE's implementation from the multiple values.

b) The value of N2 may be determined by a UE type.

For example, it is supposed that there are two types of UEs, where one has a low power WUS feature, and the other does not. In an embodiment of the present disclosure, the value of N2 for the UE having the low power WUS feature may be "2" , "3" , or any other value, and the UE without the low power WUS feature may not be configured or specified with the parameter N2. The value of N2 for the UE having the low power WUS feature may be preconfigured, defined in specifications, or the like. The new UE type may be specified in specifications.

c) The value of N2 may be determined by a UE capability.

UEs with different capabilities may have different periodicities or different values of N2. Taking mobility as an example, a UE with low mobility may be configured with a larger value of N2, and a UE with high mobility may be configured with a smaller value of N2.

d) The value of N2 may be associated with a DRX cycle length.

For example, different values of N2 may be specified for different DRX cycle lengths for FR2. An example is shown in Table 2 below.

Table 2. N _sev

Compared to Table 1, Table 2 further includes a new column of "Scaling Factor (N2) " . In the first row with a DRX cycle length being 0.32, for FR2, N2 is 8; in the second row with a DRX cycle length being 0.64, for FR2, N2 is 5; in the third row with a DRX cycle length being 1.28, for FR2, N2 is 4; in the fourth row with a DRX cycle length being 2.56, N2 is 3. N2 is 2 for FR1. The above configuration of N2 is merely exemplary, and N2 may be configured with other values.

With the periodicity of M1×N1 DRX cycle (s) defined, the UE shall measure SS-RSRP and SS-RSRQ level of a serving cell and evaluate a cell selection criterion S for the serving cell at least once every M1×N1×N2 DRX cycle (s) .

In each periodicity of M1×N1×N2 DRX cycle (s) , the main radio keeps in the "ON" mode for a time duration (which can be referred to as an "on duration" ) and then enters the "OFF" mode or "deep sleep" mode. In some embodiments, the main radio is turned off once the serving cell fulfils the cell selection criterion S or the UE receives a signal indicating the UE to turn off the main radio. In some embodiments, the length of the on duration is T DRX cycle (s) , where T is a positive integer.

The value of T may be determined in various manners as follows:

a) The value of T may be M1×N1.

This is the case shown in Fig. 4. The UE may measure SS-RSRP and SS-RSRQ level of the serving cell and evaluate the cell selection criterion S for the serving cell at least once in the T DRX cycle (s) , i.e., M1×N1 DRX cycle (s) . Measurement occasions are selected based on the SMTC periodicity and the window duration in the same manner as that described with respect to Fig. 3. In the example shown in Fig. 4, the periodicity of M1×N1×N2 DRX cycle (s) includes four SSB burst sets, the on duration (i.e., M1×N1 DRX cycle (s) ) includes two SSB burst sets, the SMTC periodicity includes one SSB burst set, and the window duration includes one SSB burst set. Accordingly, the UE may detect SSBs in two window durations respectively within two SMTC periodicities as measurement occasions in a periodicity of M1×N1×N2 DRX cycle (s) .

b) The value of T may be an integer smaller than M1×N1, such as 1, M1, N1, etc.

In such cases, a higher layer may configure a smaller SMTC periodicity for UEs with low power WUS feature. In this way, the UEs with low power WUS feature can perform measurement in a shorter time window with denser measurement occasions.

In some embodiments of the present disclosure, the length of the on duration can be extended to an integer multiple of T DRX cycle (s) . In an embodiment, in the case that the measurement in the first T DRX cycle (s) does not meet the cell selection criterion S, the UE can extend the length of the on duration to 2×T DRX cycles, 3×T DRX cycles, etc. For example, if the value of T is 1, and the first DRX cycle does not meet the cell selection criterion S, then the length of the on duration is extended to 2 DRX cycles, etc. In an embodiment, the UE can extend the length of the on duration until a serving cell of the UE fulfils a cell selection criterion.

If the UE has performed measurements in N _serv consecutive DRX cycles (please refer to Table 2) , and the serving cell does not fulfil the cell selection criterion S, the UE shall initiate the measurements of all neighbor cells indicated by the serving cell, regardless of the measurement rules currently limiting UE measurement activities. The values of N _serv listed in Table 2 are equal to the values of N _serv listed in Table 1 scaled by N2 (i.e., larger than the values of N _serv listed in Table 1) . In some other embodiments, the value of N _serv may be defined in other way.

If the UE in RRC idle state has not found any new suitable cell based on searches and measurements using the intra-frequency, inter-frequency and inter-RAT information indicated in the system information for N2×10 s, the UE shall initiate cell selection procedures for the selected PLMN.

In these embodiments, the UE turns on the main radio to perform the SSB-based RRM measurement for the serving cell with a periodicity of N3 SSB periodicity (s) (which is referred to as "Tssb" ) . That is, the length of the periodicity is N3×Tssb. Similar to N2, the value of N3 may be configured by a higher layer, preconfigured (e.g., associated with a UE type) , associated with a UE capability, or associated with a DRX cycle length.

With the periodicity of N3×Tssb defined, the UE shall measure SS-RSRP and SS-RSRQ level of a serving cell and evaluate a cell selection criterion S for the serving cell at least once every N3×Tssb.

In each periodicity of N3×Tssb, the main radio keeps in the "ON" mode for a time duration (which can be referred to as an "ON duration" ) and then enters the "OFF" mode or "deep sleep" mode. In some embodiments, the main radio is turned off once the serving cell fulfils the cell selection criterion S or the UE receives a signal indicating the UE to turn off the main radio. In some embodiments, the length of the ON duration is P×Tssb (i.e., P SSB periodicity (s) ) , where P is a positive integer.

The value of P may be determined in various manners as follows:

a) The value of P may be configured by a higher layer.

b) The value of P may be determined at least by an SMTC periodicity and DRX cycle configured according to the specifications.

For example, the value of P can be determined by the number of measurement occasions that are included in M1×N1 DRX cycle (s) as determined in the manner described with respect to Fig. 3.

As another example, the value of P can be determined by the number of measurement occasions that are contained in N _serv DRX cycle, where N _serv is defined as shown in Table 1.

c) The value of P is a fixed value, e.g., 2, 3, etc.

When the value of P is 2, there are 2 measurements that the UE can use to filter the SS-RSRP and SS-RSRQ measurements of the serving cell.

In some embodiments of the present disclosure, the length of the ON duration can be extended to an integer multiple of P SSB periodicity (s) . In an embodiment, in the case that the measurement in the first P SSB periodicity (s) does not meet the cell selection criterion S, the UE can extend the length of the ON duration to 2×P SSB periodicities, 3×P SSB periodicities, etc. In an embodiment, the UE can extend the length of the ON duration until a serving cell of the UE fulfils a cell selection criterion.

In the ON duration, the UE detects all the transmitted SSBs as measurement occasions. For example, as shown in Fig. 5, the periodicity of N3×Tssb includes four SSB burst sets, and the ON duration includes two SSB burst sets. Thus, the UE may detect SSBs in the two SSB burst sets as measurement occasions in a periodicity of N3×Tssb.

In these embodiments, after the UE operates with the main radio off (e.g., the UE is in the low power mode) for an OFF duration, the UE may turn on the main radio to perform the SSB-based RRM measurement for the serving cell at least once. The OFF duration may be configured by a higher layer, preconfigured, or flexibly determined by the UE.

After the main radio of the UE is turned on, the main radio keeps in the "ON" mode for a time duration (which can be referred to as an "ON duration" ) and then enters the "OFF" mode or "deep sleep" mode. In some embodiments, the main radio is turned off once the serving cell fulfils the cell selection criterion S or the UE receives a signal indicating the UE to turn off the main radio. In some embodiments, the length of the ON duration and the measurement occasions in each ON duration may be determined in any manner as described with respect to Figs. 4 and 5. For example, as shown in Fig. 6, the OFF duration includes three SSB burst sets, and the length of the ON duration and the measurement occasions in each ON duration are determined in the same manner as that described with respect to Fig. 4. Thus, the UE may detect SSBs in the two SSB burst sets in the ON duration as measurement occasions.

According to some embodiments of the present disclosure, the configuration of the ON duration and/or the OFF duration may be flexible. For instance, at time t ₁, the length of the ON duration is configured as 3 SSB periodicities, and the length of the OFF duration is configured as 2 SSB periodicities. At time t ₂, the length of the ON duration is configured as 1 SSB periodicity, and the length of the OFF duration is configured as 4 SSB periodicities. In this scenario, the RRM measurements performed by the UE are not periodic.

In these embodiments, a wake up signal, which is marked by "trigger" in Fig. 7, is introduced to wake up the main radio. Upon receiving the wake up signal, the UE turns on the main radio, and after an offset from reception of the wake up signal, the UE starts to perform the SSB-based RRM measurement for the serving cell. The offset may be configured for at least hardware turning on and/or synchronization.

The wake up signal may be generated by different sequences as follows:

a) sequence 1: the wake up signal generated based on sequence 1 is referred to as wake up signal 1, and wake up signal 1 is used to wake up the main radio for receiving data transmission, wherein the data transmission may include or exclude earthquake and tsunami warning system (ETWS) information, commercial mobile alert system (CMAS) information, or system information update, etc. In response to receiving wake up signal 1, the UE wakes up to receive SSBs and/or paging signals, and performs subsequent procedures (e.g., physical downlink control channel (PDCCH) blind detection, physical downlink shared channel (PDSCH) reception, etc. ) .

b) sequence 2: the wake up signal generated based on sequence 2 is referred to as wake up signal 2, and wake up signal 2 is used to wake up the main radio for RRM measurement (there is no data transmission) . In response to receiving wake up signal 2, the UE wakes up to receive SSBs to perform RRM measurement.

c) sequence 3: the wake up signal generated based on sequence 3 is used to wake up the main radio for receiving information on direct indication, e.g. ETWS information, CMAS information, or system information update, etc. The UE can wake up to receive information on direct indication without paging occasion (PO) monitoring.

In the case that the main radio is waked up by wake up signal 2, the main radio keeps in the "ON" mode for a time duration (which can be referred to as an "ON duration" ) and then enters the "OFF" mode or "deep sleep" mode. The ON duration may be started from the nearest measurement occasion (e.g., the nearest window duration) , the nearest measurement signal (e.g., the nearest SSB) , or the nearest DRX cycle after the offset from the reception of wake up signal 2, or immediately follows the offset from the reception of wake up signal 2. In the example shown in Fig. 7, the ON duration immediately follows the offset from the reception of wake up signal 2, and the UE may detect SSBs in the two SSB burst sets in the ON duration as measurement occasions.

The length of the ON duration may be determined in any manner as described with respect to Figs. 4 and 5. For example, the length of the ON duration may be configured as T DRX cycle (s) or P SSB periodicity (s) , where T and P may be determined in the same manner as that described with respect to Figs. 4 and 5 or may be any integer. In some embodiments, the length of the ON duration may be configured as an integer number of subframes or frames. Measurement occasions in each ON duration may be determined in any manner as described with respect to Fig. 4, 5, or 6.

In some other embodiments, the main radio is turned off once the serving cell fulfils the cell selection criterion S or the UE receives a signal indicating the UE to turn off the main radio.

According to some embodiments of the present disclosure, the method described with respect to Fig. 7 can be combined with those described with respect to Figs. 4, 5, and 6. For example, the UE may first turn on the main radio in response to receiving a wake up signal as described in Fig. 7, and then periodically turn on the main radio as described in Figs. 4, 5, and 6.

In step 801, the UE monitors, with the first RF component, reception of a first signal indicating to wake up a second RF component of the UE. In step 802, the UE receives, with the second RF component, information during a first time duration, or during a second time duration after receiving the first signal. For example, the first RF component (e.g., the low power wake-up receiver) monitors reception of a first signal (e.g., a wake up signal) , which indicates the UE to wake up the second RF component (e.g., the main radio) , and the second RF component (e.g., the main radio) receives information including at least one of data transmission (s) , measurement signal (s) , or system information update (s) when it is in the "ON" mode.

The UE may determine the RRM measurements based on the received information, for example, SSB.

In some embodiments, the first time duration has a periodicity equal to M1×N1×N2 DRX cycles, and has a length equal to T DRX cycles, wherein M1 is 1 or 2, N1 is a first scaling factor associated with a length of the DRX cycle and a frequency range, N2 is a second scaling factor larger than one, and T is a positive integer. Alternatively, the first time duration has a periodicity equal to N3 SSB periodicities, and has a length equal to P SSB periodicities, wherein N3 and P are positive integers.

In some embodiments, N2 or N3 is configured by a higher layer, preconfigured, associated with a UE capability, or associated with the length of the DRX cycle. Taking mobility as an example, a UE with low mobility may be configured with a larger value of N2 or N3, and a UE with high mobility may be configured with a smaller value of N2 or N3.

In some embodiments, T is smaller than or equal to M1×N1.

In some embodiments, P is configured by a higher layer, fixed, or determined by a periodicity of SMTC and the DRX cycle.

In some embodiments, the first time duration immediately follows a third time duration in which the second RF component stops information reception. For example, in the example shown in Fig. 6, the ON duration immediately follows the OFF duration.

In some embodiments, the third time duration is configured by a higher layer, preconfigured, or flexibly determined by the UE. For example, in the example shown in Fig. 6, the OFF duration may be flexibly determined by the UE.

In some embodiments, the second time duration immediately follows an offset from reception of the first signal, or starts from a nearest measurement occasion, a nearest measurement signal, or a nearest DRX cycle after the offset from the reception of the first signal. For example, in the example shown in Fig. 7, the ON duration immediately follows an offset from reception of the wake-up signal.

In some embodiments, the UE stops receiving the information after the first time duration or the second time duration, or once a serving cell of the UE fulfils a cell selection criterion, or upon receiving a signal indicating the UE to stop information reception on the second RF component.

Fig. 9 illustrates a simplified block diagram of an exemplary apparatus 900 according to some embodiments of the present disclosure. The apparatus 900 may be or include at least a part of a UE, or other device with similar functionality.

As shown in Fig. 9, the apparatus 900 may include a first RF component 902 (e.g., a low power wake-up receiver) , a second RF component 904 (e.g., a main radio) , and a processor 906. The second RF component 904 is coupled to the first RF component 902. The processor 906 is coupled to the first RF component 902 and the second RF component 904. It is contemplated that the apparatus 900 may include other components not shown in Fig. 9.

The first RF component 902, the second RF component 904, and the processor 906 can be configured to perform any of the methods described in the present disclosure, for example, the method described with respect to any of Figs. 4-8. For example, the first RF component 902 may be configured to monitor reception of a first signal indicating to wake up the second RF component 904. The second RF component 904 may be configured to receive information during a first time duration, or during a second time duration after receiving the first signal. In some embodiments, the processor 906 may be configured to determine RRM measurements based on the received information. In some embodiments, the second RF component 904 may be further configured to stop receiving the information after the first time duration or the second time duration, or once a serving cell of the UE fulfils a cell selection criterion, or upon receiving a signal indicating the UE to stop information reception on the second RF component. According to some embodiments, the first RF component 902 and the second RF component 904 may perform actions under the control of the processor 906.

The method 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 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.

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. The terms "comprises, " "comprising, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises 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 comprises 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. "

Claims

A user equipment (UE) , comprising:

a first radio frequency (RF) component;

a second RF component coupled to the first RF component; and

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

wherein the first RF component is configured to monitor reception of a first signal indicating to wake up the second RF component, and

wherein the second RF component is configured to receive information during a first time duration, or during a second time duration after receiving the first signal.
The UE of Claim 1, wherein the processor is configured to determine radio resources management (RRM) measurements based on the received information.
The UE of Claim 1, wherein

the first time duration has a periodicity equal to M1×N1×N2 discontinuous reception (DRX) cycles, and has a length equal to T DRX cycles, wherein M1 is 1 or 2, N1 is a first scaling factor associated with a length of the DRX cycle and a frequency range, N2 is a second scaling factor larger than one, and T is a positive integer; or

the first time duration has a periodicity equal to N3 synchronization signal block (SSB) periodicities, and has a length equal to P SSB periodicities, wherein N3 and P are positive integers.
The UE of Claim 3, wherein N2 or N3 is configured by a higher layer, preconfigured, associated with a UE capability, or associated with the length of the DRX cycle.
The UE of Claim 3, wherein T is smaller than or equal to M1×N1.
The UE of Claim 3, wherein the length of the first time duration is extended to an integer multiple of T DRX cycles or to an integer multiple of P SSB periodicities when a predefined condition occurs, or is extended until a serving cell of the UE fulfils a cell selection criterion.
The UE of Claim 3, wherein P is configured by a higher layer, fixed, or determined at least by a periodicity of SSB-based RRM measurement timing configuration (SMTC) and the DRX cycle.
The UE of Claim 1, wherein the first time duration immediately follows a third time duration in which the second RF component stops information reception.
The UE of Claim 8, wherein the third time duration is configured by a higher layer, preconfigured, or flexibly determined by the UE.
The UE of Claim 1, wherein the information includes at least one of data transmission (s) , measurement signal (s) , or system information update (s) .
The UE of Claim 1, wherein the second time duration has a length equal to T DRX cycles, P SSB periodicities, X subframes, or Y frames, wherein T, P, X, and Y are positive integers.
The UE of Claim 1, wherein the second time duration immediately follows an offset from reception of the first signal, or starts from a nearest measurement occasion, a nearest measurement signal, or a nearest DRX cycle after the offset from the reception of the first signal.
The UE of Claim 1, wherein the second RF component is further configured to:

stop receiving the information after the first time duration or the second time duration, or once a serving cell of the UE fulfils a cell selection criterion, or upon receiving a signal indicating the UE to stop information reception on the second RF component.
A method performed by a user equipment (UE) , comprising:

monitoring, by a first radio frequency (RF) component of the UE, reception of a first signal indicating to wake up a second RF component of the UE; and

receiving, by the second RF component , information during a first time duration, or during a second time duration after receiving the first signal.
The method of Claim 14, further comprising:

determining radio resources management (RRM) measurements based on the received information.