Methods and device for energy saving enhancement

Abstract

Methods and devices for energy saving enhancement are provided. In the method, a network device transmits a set of first reference signals at a first rate to a terminal device. Further, the network device transmits to the terminal device, in at least one time duration, one or more second reference signals for an activity associated with at least one of the terminal device or the network device. Accordingly, enhancement of network energy saving can be achieved.

Description

METHODS AND DEVICE FOR ENERGY SAVING ENHANCEMENTFIELD

[0001] Embodiments of the represent disclosure relate to the field of telecommunication and in particular, to methods and devices for energy saving enhancement.BACKGROUND

[0002] This section introduces aspects that may facilitate better understanding of the present disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.

[0003] Network (NW) energy consumption in New Radio (NR) increases with respect to LTE due to more complex hardware (HW), e.g., higher bandwidth (BW) and a larger number of transceivers. This is particularly more evident when the NW operates in higher frequencies. Hence it is important for the NW to turn ON / OFF unused HW modules during inactivity times. For example, in FR2, an NR gNB can be configured with up to 64 beams and transmit up to 64 Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Blocks (SSBs). This implies 64 ports with many transceiver chains involved. Such SSBs are transmitted every 20ms in during 5ms windows for the sake of providing coverage to potential UEs even if there actually are no UEs present in the cell.

[0004] An NR gNB may be configured with up to 64 SSBs. The configured SSBs in a cell have all the same periodicity and output power. The gNB can provide information to the UEs about how many / which SSBs that are active (present) within the serving cell and neighboring cells. The gNB can further provide information about the rate / periodicity at which these SSBs are provided on cell level. User equipment (UEs) are configured with the above SSB presence and timing / rate information either in RRC IDLE / INACTIVE mode via broadcast system information or in RRC CONNECTED mode via dedicated Radio Resource Control (RRC) messages.SUMMARY

[0005] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] In a first aspect, a method performed at a network device is proposed. In the method, the network device transmits a set of first reference signals at a first rate to a terminal device. Further, the network device transmits to the terminal device, in at least one time duration, one or more second reference signals for an activity associated with at least one of the terminal device or the network device.

[0007] In a second aspect, a method performed at a terminal device is proposed. In the method, the terminal device receives a set of first reference signals at a first rate from a network device. Further, in at least one time duration, the terminal device receives, from the network device, one or more second reference signals for an activity associated with at least one of the terminal device or the network device.

[0008] In a third aspect, a network device is proposed. The network device comprises a processor and a memory, and the memory contains instructions executable by the processor whereby the network device is operative to perform a method in accordance with the first aspect of the present disclosure.

[0009] In a fourth aspect, a terminal device is proposed. The terminal device comprises a processor and a memory, and the memory contains instructions executable by the processor whereby the terminal device is operative to perform a method in accordance with any of the second aspect of the present disclosure.

[0010] In a sixth aspect, a computer readable storage medium is provided. The computer readable storage medium may comprise instructions, which, when executed on at least one processor, cause the at least one processor to carry out the method according to any of the first aspect or the second aspect.

[0011] Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] These and other objects, features and advantages of the disclosure will become apparent from the following detailed description of illustrative embodiments thereof, which are to be read in connection with the accompanying drawings.

[0013] FIG. 1 shows a communication system in which embodiments of the disclosure can be implemented;

[0014] FIG. 2 illustrates a signaling chart for communications in accordance with some embodiments of the present disclosure;

[0015] FIG. 3 illustrates an example diagram of an aperiodic time duration for the second reference signals in accordance with some embodiments of the present disclosure;

[0016] FIG. 4 illustrates an example diagram of periodic time durations for the second reference signals in accordance with some embodiments of the present disclosure;

[0017] FIG. 5 illustrates a flowchart of a method implemented at a network device in accordance with an embodiment of the present disclosure;

[0018] FIG. 6 illustrates a flowchart of a method implemented at a terminal device in accordance with an embodiment of the present disclosure;

[0019] FIG. 7 illustrates a block diagram showing an apparatus suitable for use in practicing some embodiments of the present disclosure;

[0020] FIG. 8 illustrates a block diagram showing a terminal device or a network device suitable for use in practicing some embodiments of the present disclosure;

[0021] FIG. 9 illustrates an example of a communication system in accordance with some embodiments of the present disclosure;

[0022] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0023] For the purpose of explanation, details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed. It is apparent, however, to those skilled in the art that the embodiments may be implemented without these specific details or with an equivalent arrangement.

[0024] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained withinthe scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0025] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0026] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present disclosure should be or are in any single embodiment of the disclosure. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Furthermore, the described features, advantages, and characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the disclosure may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the disclosure.

[0027] As used herein, the terms “first”, “second” and so forth refer to different elements. The singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including” as used herein, specify the presence of stated features, elements, and / or components and the like, but do not preclude the presence or addition of one or more otherfeatures, elements, components and / or combinations thereof. The term “based on” is to be read as “based at least in part on”. The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment”. The term “another embodiment” is to be read as “at least one other embodiment”. Other definitions, explicit and implicit, may be included below. The term “one or more elements” used is to be read as “only one element” or “a plurality of elements”. The term “at least element” used is to be read as “only one element” or “more than one element”.

[0028] As used herein, the term “terminal device” / “communication device” may be any device intended for accessing services via an access network and configured to communicate over the access network. For instance, the terminal device / communication device may be, but is not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, television, radio, lighting arrangement, tablet computer, laptop, or PC. The terminal device / communication device may be a portable, pocket storable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and / or data, via a wireless or wireline connection. The term “terminal device” may be referred to as a mobile station (MT). Alternatively, the term “terminal device” may be referred to as a user equipment (UE). The terms “terminal device” and “UE” can be used interchangeably hereinafter.

[0029] The term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology.

[0030] FIG. 1 illustrates a communication system 100 in which embodiments of the disclosure can be implemented. As shown in FIG. 1, the communication system 100 includes a network device 110. The communication system 100 also includes a terminal device 120. The terminal device 120 is currently served by a cell 101 managed by the network device 110.

[0031] It can be understood that the number of devices and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication system 100 may include any suitable number of devices configured to implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional terminal devices may be located in the cell 101, and one or more additional cells may be deployed in the communication system 100. The number of terminal device(s) in a cell or network device(s) does not suggest any limitation.

[0032] In some embodiments, a channel from the network device 110 to the terminal device 120 is referred to as a downlink (DL), while a channel from the terminal device 120 to the network device 110 is referred to as an uplink (UL). In the DL, the network device 110 is a transmitting (TX) device (or a transmitter) and the terminal device 120 is a receiving (RX) device (or a receiver). In the UL, the terminal device 120 is a TX device (or a transmitter) and the network device 110 is a RX device (or a receiver). In some embodiments, device-to-device (D2D) or sidelink (SL) communication may be conducted between terminal devices 120. A direct link may be established between the terminal devices 120 for the D2D or SL communication. The direct link may also be referred to as a SL or D2D link. In the D2D or SL communication, a terminal device 120 may act as a TX device (or a transmitter), and one or more terminal devices 120 may act as a TX device(s) (or a receiver(s)).

[0033] Communications in the communication system 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0034] Many communication systems use reference signals (sometimes also called “pilot symbols”), which are pre-determined signals that are transmitted over a communication channel and used in the receiver to, for example, improve the quality of reception by allowing estimation of unknown parameters such as the channel response (also referred to as channel information). Reference signals may be transmitted in UL, DL, or SL. In UL, a transmitter of reference signals is a terminal device, e.g., the terminal device 120, and a receiver of the reference signals is a network device, e.g., a network device 110. For example, at least one terminal device may transmit reference signals to at least one network device for estimation of channel information about the corresponding channel from the at least one terminal device to the network device. In DL, a transmitter of reference signals is a network device, e.g., a network device 110, and a receiver of the reference signals is a terminal device, e.g., the terminal device 120. For example, at least one network device may transmit reference signals to at least one terminal device for estimation of channel information about the corresponding channel from the at least one network device to the terminal device. In SL, a transmitter of reference signals may be a terminal device, and one or more other terminal devices may be a receiver(s) of the reference signals. The reference signals transmitted between the terminal devices may be similarly used to estimate the channel between the terminal devices.

[0035] In wireless communication systems, a reference signal (RS) is typically used for various purposes such as channel estimation, synchronization, and interference cancellation. For instance, the reference signal may include but not limited to the following examples:• Synchronization Signal (for example, SSB): a synchronization signal refers to a signal used in communication systems to synchronize the receiver and transmitter. It is usually used to synchronize clock, frequency, phase, and other parameters to ensure that the receiver can correctly receive and process the data sent by the transmitter.• Cell Reference Signal (CRS): In LTE and 5G NR, CRS is a reference signal for all users in a cell. It may be broadcast on all resource blocks and used for channel estimation and synchronization.• Demodulation Reference Signal (DM-RS): In LTE and 5G NR, DM-RS is a reference signal for a specific UE. It may be used for UE modulation and demodulation to improve reception performance.• Positioning Reference Signal (PRS): In LTE and 5GNR, PRS is a reference signal for positioning services. It may be broadcast at specific time and frequency locations to support location-based services.• Sounding Reference Signal (SRS): In LTE and 5G NR, SRS is a reference signal for channel state information (CSI) measurement. UE sends SRS to help a base station evaluate channel quality and perform resource allocation.

[0036] These are common examples of reference signals in 3 GPP standards, and the specific reference signals may vary depending on the different wireless communication systems. Typically, the SSBs transmission rate is configured for the most demanding scenarios. For example, most deployments use 20ms period for SSB transmission, especially on the Global Synchronization Channel Number (GSCN), to ensure optimal performance in UE cell search time, and also to have high enough provision rate for RRC CONNECTED mode operations. In the context of NES, it is desirable to decrease the rate of SSBs, especially when Idle / Inactive mode Rx / Tx activities are condensed in time. The rate of SSBs could e.g. be in the range of once every 960ms rather than today’s 20ms period. The problem with lower SSB density in time is that the UEs may not be able to perform well for certain activities. This is especially true for UEs in poor coverage. For example, a UE in poor coverage my need up to 3-4 instances of SSBs for its loop convergence (Automatic Generation Control (AGC) / Automatic Frequency Control (AFC)) to be able to decode the paging channel. If the distance between the SSB occasions is too sparse, the UEs may not be able to carry out its Idle mode operations.

[0037] Generally, a periodic RS implies a constant resource energy consumption penalty for the network device 110 while the RS is activated. Thus, there is a need for an approach that allows complementing a baseline low-rate periodic SSB with additional RS to support specific operations of the terminal device 120 without imposing a periodic transmission task on the network device 110.

[0038] To solve the above and other potential issues, embodiments of the present disclosure proposes a solution for energy saving enhancement. In the proposed solution, a network device operates in a relaxed mode such that it provides reference signals (e.g., cell-defining SSBs) for operations of terminal device(s) in IDLE / INACTIVE mode in a sparse manner. In relation to certain occasions / activities, such as paging occasions (POs), random access occasions, system information, and so on, the network device provides a burst (one or multiple) of SSBsprior / during / after the occasions. For example, prior to the POs, the network device ensures that there exists a time duration (for instance, a time window) which includes a number of RSs (e.g., 3-4 instances of densely provided SSBs) a certain time offset before the POs. In another example, the network device may provide multiple bursts of SSBs in time durations periodically.

[0039] As such, the network device can enjoy deeper sleep states outside the time duration(s), e.g., SSB burst windows, while terminal device(s) (even poor coverage UE) can carry out necessary operations.

[0040] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0041] Reference is now made to FIG. 2, which shows a signaling chart 200 for communications according to some embodiments of the present disclosure. As shown in FIG. 2, the signaling chart 200 involves a network device and a terminal device. For purpose of discussion, the network device and the terminal device in embodiments of FIG. 2 will be discussed with reference to the network device 110 and the terminal device 120, as discussed in FIG. 1. It is to be understood that this is just for illustration, rather than suggest any limitation. Other suitable network devices and terminal devices other than the network device 110 and the terminal device 120 may be also applied to embodiments of the present disclosure.

[0042] In the signaling flow 200, the network device 110 transmits (205) a set of first reference signals at a first rate to the terminal device 120.

[0043] In some embodiments, the set of first reference signals may be associated with at least one of: cell evaluation, cell section, or cell reselection of the terminal device 120. For example, the first reference signals may be synchronization signals, which are referred to as first synchronization signals hereafter. The terminal device 120 may mainly rely on the first synchronization signals (e.g., cell defining SSBs) for the basic idle mode operations such as serving cell evaluation, cell (re-)selection, and so on. Specifically, the terminal device 120 may perform the above basic idle mode operations based on the first synch signal provision.

[0044] In addition to the set of first reference signals, the network device 110 transmits (215) one or more second reference signals for an activity associated with the network device 110 and / or the terminal device 120 to the terminal device 120 in at least one time duration.

[0045] In some embodiments of the present disclosure, the activity may include, for example,but not limited to paging, a random-access procedure, a system information transmission, a broadcast, a multi-cast transmission, and so on.

[0046] The second reference signal may be implemented in various ways. For example, a second reference signal may comprise a synchronization signal. The synchronization signal may comprise either of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), or both.

[0047] In the case that both the PSS and the SSS are included in the second reference signal, they may be separated by a predetermined time interval. The length of the predetermined time interval may be predefined in specification or configured by the network device 110. Thus, the PSS and the SSS included in a single second reference signal may be lightly separated. In some embodiments, the length of the predetermined time interval may be 0, which means that the PSS and the SSS included in a single second reference signal may be transmitted back-to-back.

[0048] In some embodiments, the one or more second reference signals may be transmitted prior to or during an occasion for the activity, for example, a paging occasion, a random-access occasion, an occasion for a system information transmission, an occasion for a broadcast, or an occasion for a multi-cast transmission.

[0049] In some embodiments, second reference signal(s) may be transmitted (215) in one or more time durations. The duration(s) may be aperiodic or periodic. For example, there may be only one aperiodic time duration for transmitting the second reference signals. For example, if a burst of SSBs are to be transmitted for a certain activity, for example, paging, the network device 110 may transmit in a single time duration to transmit the burst of SSBs. In this case, the time duration is aperiodic. In another case where the second reference signals are regularly needed, the network device 110 may transmit the second reference signals in periodic time durations, and one or more second reference signals are transmitted in each of the periodic time durations.

[0050] In some embodiments, there may be only one second reference signal, for example, one SSB, in each time duration. Alternatively, in some embodiments, there may be a plurality of second reference signals, e.g., SSBs, in each time duration. The number of second reference signals in a time duration may determined in several ways. In some embodiments, the network device 110 may determine the number of second reference signals in the one or more second reference signals based on the activity, for example, but not limited to paging, a random-access procedure, a system information transmission, a broadcast, and a multi-cast transmission.

[0051] The second reference signals may have the same time type, or may have different types, where each type of the second reference signals corresponds to a type of terminal device 120, for example, a type of terminal devices or the activity. The terminal device 120 may have various types, for example, it may be a device to device (D2D) UE, a vehicular to vehicular (V2V) device, a machine type UE, a MTC UE or a UE capable of machine to machine (M2M) communication, a PDA, a tablet, a mobile terminal, a smart phone, a laptop embedded equipment (LEE), a laptop mounted equipment (LME), a USB dongle, and so on.

[0052] In some embodiments, the second reference signals in a single time duration may be of the same type. Alternatively, the second reference signals in a single time duration may have at least two types. That is, different types of the second reference signals may be transmitted in a single time period. As a further alternative, the second reference signals transmitted in one time durations may be different from the second reference signals transmitted in another time duration.

[0053] Additionally, in some embodiments, the network device 110 may configure the terminal device 120 regarding the transmission of the second reference signals. For example, the network device 110 may configure which signal transmissions or procedures are accompanied by the second reference signal bursts. In an embodiment, the network device 110 may transmits configuration information (also referred to as “first configuration information” for purpose of discussion) to the terminal device 120. The first configuration information may be about a length of a time duration, a periodicity of periodic time durations, the number of second reference signals in the time duration, a periodicity of the second reference signals in the time duration, a time offset of the time duration relative to a first reference signal, a time offset relative to the activity, and / or the like.

[0054] The first configuration information is transmitted via a variety of messages / information. For instance, the network device 110 may transmit the first configuration information may be transmitted via System Information Block (SIB) information, for example, in IDLE / INACTIVE mode. Alternatively, the first configuration information may be transmitted via a Radio Resource Control (RRC) signaling or a Medium Access Control Control Element (MAC CE), for example, in a CONNECTED mode. As a further alternative, the first configuration information may be transmitted via Downlink Control Information (DCI). For example, if there is an associated upcoming paging message, in a paging early indication(PEI) DCI, the network device 110 may indicate that there is also a burst of SSBs prior to the paging message.

[0055] It is to be understood that the above examples are just illustrated for purpose ofdiscussion, without suggesting any limitation. Other signaling or information may be also applied to embodiments of the present disclosure.

[0056] In some embodiments, some configuration may be performed during one of the at least one time duration. For example, in one time duration, the network device 110 may transmit second configuration information to the terminal device 120. The second configuration information may include a reference signal burst occasion, the number of reference signal burst occasions within the time duration, a periodicity of the reference signal, or a length of the reference signal. In an implementation, the second configuration information may be about, for example, a SSB burst occasion, the number of SSB burst occasions within the time duration, a periodicity of the SSB, a length of the SSB, and / or the like.

[0057] In some embodiments, before the start of the signaling chart 200, the terminal device 120 may first transmit capability information to the network device 110 to indicate its capability about receiving both the set of first reference signals and the one or more second reference signals. The network device 110, upon receiving the capability information, may be aware whether the terminal device 120 is capable of receiving both the set of first reference signals and the one or more second reference signals. Thus, the network device 110 will know the second reference signal(s) to be transmitted (215) can be received and / or employed properly.

[0058] The terminal device 110 receives (210) the set of first reference signals from a network device 120 and receives (220), in at least one time duration, one or more second reference signals for the activity associated with at least one of the terminal device 120 or the network device 110.

[0059] In an example, the first set of reference signals may include sparse SSBs. The terminal device 120, which is capable of processing the sparse SSBs, may search the SSBs based on NES-based SSB configuration, such as a sparse SSB periodicity.

[0060] In some embodiments, the terminal device 120 may select a subset from the received set of the second reference signals based on a processing capability or a coverage of the terminal device. As such, the terminal device 120 may choose to use fewer number of the second reference signals depending on its capabilities and coverage. In an implementation, for a terminal device 120, e.g., a UE, in good coverage, or equipped with advanced receiver, fewer second reference signals may suffice for carrying out the intended activity.

[0061] Sometimes, the terminal device 120 may not find a master information block (MIB) from the second reference signal which is implemented as a synchronization signal, e.g.,including PSS+SSS only. Then the terminal device 120 may reuse the same MIB from the first reference signals. In some embodiments, the terminal device 120 may determine whether a MIB is present in the one or more second reference signals. If not, the terminal device 120 may obtain a MIB from the set of the first reference signals.

[0062] In view of the above, rather than constantly providing first references signals (e.g., SSBs) at a high rate (e.g., every 20ms) to cater for the most demanding scenarios (e.g., terminal devices in CONNECTED mode), the network device 110 only needs to transmit SSBs at a low rate. As such, there will be a very long gaps between each transmission occasions. During these long gaps, the network device 110 will enter a long deep sleep mode, leading to lower energy consumption. Only in relation to certain activities, the network device 110 provides a burst of extra SSBs. In this way, certain activities, such as a burst matter, may be performed while achieving energy saving.

[0063] FIG. 3 illustrates an example diagram of an aperiodic time duration for the second reference signals in accordance with some embodiments of the present disclosure. In embodiments described with respect to FIG. 3, the first reference signals may be discussed as first synchronization signals, and the second reference signals may be discussed as second synchronization signals, for example. There is only one burst of the second synchronization signals. The time duration 310 for this burst is also referred to as a monitoring window 310. The first synchronization signals are transmitted periodically, for example, in a sparse periodicity 320.

[0064] As shown in the time duration 310, a plurality of second synchronization signals (e.g., 4 SSBs) are transmitted periodically. The periodicity of the second synchronization signals, for example, the periodicity of SSBs, may be indicated by a time period 330.

[0065] As discussed above, the network device 110 may configure the terminal device 120 by transmitting during the time duration 310 configuration information, for example, but not limited to, a SSB burst occasion 301, the number of SSB burst occasions within the time duration 310, a SSB periodicity 330, or the SSB length 302. The terminal device 120 may receive the SSBs in the time duration 310 and perform the related activity, such as paging, the random-access procedure, the system information transmission, the broadcast or the multi-cast transmission.

[0066] FIG. 4 illustrates an example diagram of periodic time durations for the second reference signals in accordance with some embodiments of the present disclosure. In embodimentsdescribed with respect to FIG. 4, the first reference signals may be discussed as first synchronization signals, and the second reference signals may be discussed as second synchronization signals, for example. Different from embodiments of FIG. 3, there are periodic time durations for transmitting the second reference signals, for example, a first time duration 410-1, a second time duration 410-2 and so on. That is, there are several monitoring windows for the second reference signals. The first synchronization signals are transmitted periodically, for example, in a sparse periodicity 420.

[0067] As shown in the first time duration 410-1, a plurality of second synchronization signals (e.g., 4 SSBs) are transmitted periodically. The periodicity of the second synchronization signals, for example, the periodicity of SSBs, may be indicated by a time period 430. The second time duration 410-2 also includes 4 SSBs for example, which have the same SSB periodicity 430. As shown in FIG. 4, a periodicity of the periodic time durations (the first time duration 410-1 and the second time duration 410-2) is denoted with a time interval 440.

[0068] As discussed above, the network device 110 may configure the terminal device 120 by transmitting configuration information, for example, but not limited to, a length of a time duration 410-1 and / or 410-2, a periodicity 440 of periodic time durations, the number of second reference signals in the time duration (in this case, 4), a periodicity 43 Oof the second reference signals in the time duration, a time offset of the time duration relative to a first reference signal, or a time offset relative to the activity.

[0069] It is to be noted that the above discussion are just for example, rather than suggest any limitations. The above discussed or other configuration information may be transmitted or changed from the netwrok device 110 to the terminal device 120 at any suitable time, for example, before any time duration for transmitting the second reference signal(s), in a first one of the period time durations, in the aperiodic time duration, and so on.

[0070] More details will be discussed with reference to embodiments below. In the following embodiments, the network device 110 may be also referred to as a network node or NW, and the terminal device 120 may also referred to as a UE. Examples of network nodes may be for example, NodeB, base station (BS), multi-standard radio (MSR) radio node such as MSR BS, eNodeB, gNodeB, MeNB, SeNB, location measurement unit (LMU), integrated access backhaul (IAB) node, network controller, radio network controller (RNC), base station controller (BSC), relay, donor node controlling relay, base transceiver station (BTS), CentralUnit (e.g. in a gNB), Distributed Unit (e.g. in a gNB), Baseband Unit, Centralized Baseband, C-RAN, access point (AP), transmission points, transmission nodes, transmission reception point (TRP), RRU, RRH, nodes in distributed antenna system (DAS), core network node (e.g. MSC, MME etc), O&M, OSS, SON, positioning node (e.g. E-SMLC), etc.

[0071] The non-limiting term UE refers to any type of wireless device communicating with a network node and / or with another UE in a cellular or mobile communication system. Examples of UE are target device, device to device (D2D) UE, vehicular to vehicular (V2V), machine type UE, MTC UE or UE capable of machine to machine (M2M) communication, PDA, tablet, mobile terminals, smart phone, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles etc.

[0072] The term radio access technology, or RAT, may refer to any RAT e.g. UTRA, E-UTRA, narrow band internet of things (NB-IoT), WiFi, Bluetooth, next generation RAT, New Radio (NR), 4G, 5G, NR NTN, loT NTN, LTE NTN, etc. Any of the equipment denoted by the term node, network node or radio network node may be capable of supporting a single or multiple RATs.

[0073] The term signal or radio signal used herein can be any physical signal or physical channel. Examples of DL physical signals are reference signal (RS) such as PSS, SSS, CSI-RS, DMRS signals in SS / PBCH block (SSB), discovery reference signal (DRS), CRS, PRS etc. RS may be periodic e.g. RS occasion carrying one or more RSs may occur with certain periodicity e.g. 20 ms, 40 ms etc. The RS may also be aperiodic. Each SSB carries NR-PSS, NR-SSS and NR-PBCH in 4 successive symbols. One or multiple SSBs are transmit in one SSB burst which is repeated with certain periodicity e.g. 5 ms, 10 ms, 20 ms, 40 ms, 80 ms and 160 ms. The UE is configured with information about SSB on cells of certain carrier frequency by one or more SS / PBCH block measurement timing configuration (SMTC) configurations. The SMTC configuration comprising parameters such as SMTC periodicity, SMTC occasion length in time or duration, SMTC time offset wrt reference time (e.g. serving cell’s SFN) etc. Therefore, SMTC occasion may also occur with certain periodicity e.g. 5 ms, 10 ms, 20 ms, 40 ms, 80 ms and 160 ms. Examples of UL physical signals are reference signal such as SRS, DMRS etc. The term physical channel refers to any channel carrying higher layer information e.g. data, control etc. Examples of physical channels are PBCH, NPBCH, PDCCH, PDSCH, sPUCCH, sPDSCH, sPUCCH, sPUSCH, MPDCCH, NPDCCH, NPDSCH, E-PDCCH, PUSCH, PUCCH, NPUSCH etc.

[0074] Embodiments of the present disclosure aims to change the conventional provision scheme where all SSBs are constantly provided at the same rate irrespective of UE’s operation. Rather than constantly providing SSBs at a high rate (e.g., every 20ms) to cater for the most demanding scenarios (e.g., CONNECTED mode UEs), the gNB only transmits SSBs at a lower rate than typical existing configurations, e.g. every 640 or 960ms instead of the typical 20ms rate. As such, there will be a very long gaps between each transmission occasions. During these long gaps, NW will enter a long deep sleep mode, leading to lower energy consumption in the RAN.

[0075] In relation to certain activities, an extra set of synchronization signals (e.g., SSBs) are provided. The NW ensures that the aggregate of the first and second synchronization signals are enough for a UE to carry out intended activity. For example, extra set (burst) of SSB instances are provided in conjunction / prior to the paging occasions, or random access signals.

[0076] In one aspect, the number of instances is configured based on a periodical patterns in FIG. 4. For example, there could always be 4 extra SSBs provided in conjunction to the activities.

[0077] In another aspect, the number of instances is tailored to each intended activity. For example, it may be enough for UEs, even if in poor coverage, to process a single SSB for its loop convergence for decoding a PDCCH message while more instances may be needed for the sake of PDSCH decoding. For example, the UEs may be provided a single extra SSB prior to the PDCCH-based Paging Early Indication (PEI), while be provided with more instances e.g., 4 SSB, in case there is a PDCCH / PDSCH paging message. Thus, aperiodic SMW can be indicated to UE with different number of 2nd SSB occasions.

[0078] In one embodiment, the availability of the extra synch signal instances may be indicated via lower layer signaling. For example, the PEI may carry an indicator that in relation / prior to an upcoming PDCCH / PDSCH paging message there will be a burst of SSBs.

[0079] In one embodiment, the second synchronization signals are provided in adjacent symbols (back-to-back) in relation to a certain activity.

[0080] In another embodiment, the second synchronization signals, even though provided in a denser manner than that of the first synchronization signals, are spread in a window in relation to the intended activity.

[0081] In one embodiment, the second synchronization signals are swept by all beams or a partial of all beams, which depends on UE's RRC status. For one example, the second synchronization signals are swept by all beams for IDLE / IN ACTIVE mode UE. For another example, the second synchronization signals are sent on specific beams for RRC connected UE, since the beams direction of that UE is known and traced by NW. Since NW sends the second synchronization signals on less beams, it is possible to have more instances for RRC connected UE.

[0082] In another embodiment, the second and first synchronization signals are provided by different cells or nodes. E.g., the first synchronization signals are provided by capacity cell and the second synchronization signals are provided by coverage cell. Or the opposite, the first synchronization signals are provided by coverage cell and the second synchronization signals are provided by capacity cell. For the latter case, the capacity cell can stay asleep if no synch signal burst is needed.

[0083] In one embodiment, the second synchronization signals could be a non-SSB signals, e.g., PSS+SSS. In one example, all instances of second synchronization signals are non-SSB signals or SSB signals. In another examples, instances are composed of non-SSB signals and SSB signals. UE shall follow the MIB information from the first synchronization signals if not provided by 2nd synchronization signals.

[0084] In yet another embodiment, if the second and first synchronization signals are provided by different cells, the second synchronization signals can be non-SSB signals, e.g., PSS+SSS, and UE should extract cell info, e.g., MIB from the first synchronization signals.

[0085] In another embodiment, the second synchronization signals which composed of multiple instances e.g. 3-4 instances may have different beam compositions for better coverage. For example, the first instance have different beam directions than the second instance, and so on.

[0086] In another embodiment, the second synch signal can be activated in a specific time where demand for initial access of UEs are high e.g. sudden arrival of train, airplane etc. on a specific places like airport, train station, etc.

[0087] In another embodiment, the second synchronization signals can be applicable to multiple cells with overlapping coverage area. In order to avoid interference during multiple transmission instances from difference cells, there should be coordination from multiple cellson how to transmit the second synchronization signals in a burst matter. The multiple cells can use low rate SSB transmission and transmit the second synchronization signals in a coordinate manner during 960ms time window. For example, the first to fourth instances (can be around 80ms) will be from cell A while the next first to fourth instances will be from cell B. In another embodiment, the first to fourth instances can be created from different cells, e.g. first instance can be from cell A, second instance can be from cell B., and so on.

[0088] In another embodiment, the second synch signal can be use for handover such that the target cell only uses low rate SSB transmission while transmit the second synch signal during handover in a burst manner. In order to have successful handover, the UE may require assistance from the current cell on how to capture the burst synch signal from the target cell e.g. timing of receiving the second synch signal e.g. via RRCReconfiguration during CHO configuration. The UE may report to the current cell if no successful reception of the burst synch signal so that the target cell may transmit another instance of second synch signal.

[0089] A legacy UE may not be able to camp on the cell with the NES mode. As such, the network device may set the indication to notify the legacy UE which can not camp on it, e.g., by setting the cellBarred flag in MIB or any other information element so that the legacy UE does not camp on it. The legacy UE may then continue to search for other cells in that area, potentially overlapping.

[0090] Fig. 5 illustrates a flowchart of a method 500 implemented at a network device in accordance with embodiments of the present disclosure. For purpose of discussion, embodiments of FIG. 5 are discussed with reference FIG. 1. The network device is described with the network device 110 of FIG. 1, and the terminal device is described with the terminal device 120 of FIG. 1.

[0091] At block 510, the network device 110 transmits, to the terminal device 120, a set of first reference signals at a first rate.

[0092] At block 520, the network device 110 transmits, in at least one time duration and to the terminal device, one or more second reference signals for an activity associated with at least one of the terminal device 120 or the network device 110.

[0093] In some embodiments, a second reference signal comprises a synchronization signal, the synchronization signal comprises one or more of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and the PSS and the SSS areseparated by a predetermined time interval.

[0094] In some embodiments, the one or more second reference signals are transmitted prior to or during an occasion for at least one of the following activities: paging, a randomaccess procedure, a system information transmission, a broadcast, or a multi-cast transmission.

[0095] In some embodiments, in addition to the above, the network device 110 may further determine the number of second reference signals in the one or more second reference signals based on the activity.

[0096] In some embodiments, the second reference signals in the one or more second reference signals are of one type or of a plurality of types, and each type of the second reference signals corresponds to a type of terminal devices or the activity.

[0097] In some embodiments, the at least one time duration is aperiodic or periodic.

[0098] In some embodiments, the method 500 further comprises: transmitting, to the terminal device, first configuration information about at least one of: a length of a time duration, a periodicity of periodic time durations, the number of second reference signals in the time duration, a periodicity of the second reference signals in the time duration, a time offset of the time duration relative to a first reference signal, or a time offset relative to the activity.

[0099] In some embodiments, the first configuration information is transmitted via at least one of SIB information, a RRC signaling, a MAC CE, or DCI.

[0100] In some embodiments, in addition to the above, the network device 110 may transmit, to the terminal device and during one of the at least one time duration, second configuration information about at least one of a reference signal burst occasion, the number of reference signal burst occasions within the time duration, a periodicity of the reference signal, or a length of the reference signal. For example, the second configuration information may include a SSB burst occasion, the number of SSB burst occasions within the time duration, a periodicity of the SSB, or a length of the SSB.

[0101] In some embodiments, the set of first reference signals are associated with at least one of: cell evaluation, cell section, or cell reselection of the terminal device 120.

[0102] In some embodiments, the network device 110 may further receive, from theterminal device 120, capability information about whether the terminal device 120 is capable of receiving both the set of first reference signals and the one or more second reference signals.

[0103] In some embodiments, the activity comprises at least one of paging, a randomaccess procedure, a system information transmission, a broadcast, or a multi-cast transmission.

[0104] Fig. 6 illustrates a flowchart of a method 600 performed at a terminal device in accordance with embodiments of the present disclosure. For purpose of discussion, embodiments of FIG. 6 are discussed with reference FIG. 1. The network device is described with the network device 110 of FIG. 1, and the terminal device is described with the terminal device 120 of FIG. 1.

[0105] At block 610, the terminal device 120 receives, from the network device 110, a set of first reference signals transmitted at a first rate.

[0106] At block 620, the terminal device 120 receives, in at least one time duration and from the network device 110, a one or more second reference signals for an activity associated with at least one of the terminal device 120 or the network device 110.

[0107] In some embodiments, a second reference signal comprises a synchronization signal, the synchronization signal comprises one or more of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and the PSS and the SSS are separated by a predetermined time interval.

[0108] In some embodiments, the one or more second reference signals are transmitted prior to or during an occasion for at least one of the following activities: paging, a randomaccess procedure, a system information transmission, a broadcast, or a multi-cast transmission.

[0109] In some embodiments, the second reference signals in the one or more second reference signals are of one type or of a plurality of types, and each type of the second reference signals corresponds to a type of terminal devices or the activity.

[0110] In some embodiments, the at least one time duration is aperiodic or periodic.

[0111] In some embodiments, the terminal device 120 may further receive, from the network device 110, first configuration information about at least one of: a length of atime duration, a periodicity of periodic time durations, the number of second reference signals in the time duration, a periodicity of the second reference signals in the time duration, a time offset of the time duration relative to a first reference signal, or a time offset relative to the activity.

[0112] In some embodiments, the first configuration information is received via at least one of: SIB information, a RRC signaling, a MAC CE, or DCI.

[0113] In some embodiments, the terminal device 120 may further receive from the network device 110 and during one of the at least one time duration, second configuration information about at least one of a reference signal burst occasion, the number of reference signal burst occasions within the time duration, a periodicity of the reference signal, or a length of the reference signal. For example, the second configuration information may include a SSB burst occasion, the number of SSB burst occasions within the time duration, a periodicity of the SSB, or a length of the SSB.

[0114] In some embodiments, the set of first reference signals are associated with at least one of: cell evaluation, cell section, or cell reselection of the terminal device 120.

[0115] In some embodiments, the terminal device 120 may further transmit to the network device 110, capability information about whether the terminal device 120 is capable of receiving both the set of first reference signals and the one or more second reference signals.

[0116] In some embodiments, the terminal device 120 may further select a subset from the received set of the second reference signals based on a processing capability or a coverage of the terminal device 120.

[0117] In some embodiments, the terminal device 120 may further determine whether the one or more second reference signals comprise a master information block (MIB) is present in the one or more second reference signals; and in accordance with a determination that the MIB is absent from the one or more second reference signals, obtain a MIB from the set of the first reference signals.

[0118] In some embodiments, the activity comprises at least one of: paging, a randomaccess procedure, a system information transmission, a broadcast, or a multi-cast transmission.

[0119] FIG. 7 is a block diagram showing an apparatus 700 suitable for use in practicing some embodiments of the disclosure. For example, the network device 110 or the terminal device 120 described above may be implemented through the apparatus 700. As shown, the apparatus 700 may include a processor 710, a memory 720 that stores a program, and optionally a communication interface 730 for communicating data with other external devices through wired and / or wireless communication.

[0120] The program includes program instructions that, when executed by the processor 710, enable the apparatus 700 to operate in accordance with the embodiments of the present disclosure, as discussed above. That is, the embodiments of the present disclosure may be implemented at least in part by computer software executable by the processor 710, or by hardware, or by a combination of software and hardware.

[0121] The memory 720 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memories, magnetic memory devices and systems, optical memory devices and systems, fixed memories and removable memories. The processor 710 may be of any type suitable to the local technical environment, and may include one or more of general- purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi-core processor architectures, as non-limiting examples.

[0122] FIG. 8 shows a block diagram showing an apparatus 800 suitable for use in practicing some embodiments of the present disclosure. For example, the apparatus 800 may be the network device 110 or the terminal device 120 shown in FIG. 1. As shown in FIG. 8, the apparatus 800 may include a transceiver module 810 and a processing module 820. The transceiver module 810 and the processing module 820 may be configured to perform the method described with reference to any of FIGS. 1-6.

[0123] FIG. 9 shows an example of a communication system 3100 in accordance with some embodiments.

[0124] In the example, the communication system 3100 includes a telecommunication network 3102 that includes an access network 3104, such as a radio access network (RAN), and a core network 3106, which includes one or more core network nodes 3108. The access network 3104 includes one or more access network nodes, such as network nodes 3110a and 3110b (one or more of which may be generally referred to as network nodes 3110), or any other similar 3rdGeneration Partnership Project (3 GPP) access node or non-3GPP access point. The network nodes 3110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 3112a, 3112b, 3112c, and 3112d (one or more of which may be generally referred to as UEs 3112) to the core network 3106 over one or more wireless connections.

[0125] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 3100 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 3100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0126] The UEs 3112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 3110 and other communication devices. Similarly, the network nodes 3110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 3112 and / or with other network nodes or equipment in the telecommunication network 3102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 3102.

[0127] In the depicted example, the core network 3106 connects the network nodes 3110 to one or more hosts, such as host 3116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 3106 includes one more core network node (e.g., core network node 3108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 3108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM),Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0128] The host 3116 may be under the ownership or control of a service provider other than an operator or provider of the access network 3104 and / or the telecommunication network 3102 and may be operated by the service provider or on behalf of the service provider. The host 3116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0129] As a whole, the communication system 3100 of FIG. 9 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0130] In some examples, the telecommunication network 3102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 3102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 3102. For example, the telecommunications network 3102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC)ZMassive loT services to yet further UEs.

[0131] In some examples, the UEs 3112 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit informationto the access network 3104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 3104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi -standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e., being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0132] In the example, the hub 3114 communicates with the access network 3104 to facilitate indirect communication between one or more UEs (e.g., UE 3112c and / or 3112d) and network nodes (e.g., network node 3110b). In some examples, the hub 3114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 3114 may be a broadband router enabling access to the core network 3106 for the UEs. As another example, the hub 3114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 3110, or by executable code, script, process, or other instructions in the hub 3114. As another example, the hub 3114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 3114 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 3114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 3114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 3114 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

[0133] The hub 3114 may have a constant / persistent or intermittent connection to the network node 3110b. The hub 3114 may also allow for a different communication scheme and / or schedule between the hub 3114 and UEs (e.g., UE 3112c and / or 3112d), and between the hub 3114 and the core network 3106. In other examples, the hub 3114 is connected to the core network 3106 and / or one or more UEs via a wired connection. Moreover, the hub 3114 may be configured to connect to an M2M service provider over the access network 3104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 3110 while still connected via the hub 3114 via a wired or wireless connection. In some embodiments, the hub 3114 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the networknode 3110b. In other embodiments, the hub 3114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 3110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0134] In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the exemplary embodiments of this disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0135] As such, it should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be practiced in various components such as integrated circuit chips and modules. It should thus be appreciated that the exemplary embodiments of this disclosure may be realized in an apparatus that is embodied as an integrated circuit, where the integrated circuit may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor, a digital signal processor, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this disclosure.

[0136] It should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be embodied in computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, RAM, etc. As will be appreciated by one skilled in the art, the function of the program modules may be combined or distributed as desired in various embodiments. In addition, thefunction may be embodied in whole or in part in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like.

[0137] References in the present disclosure to “one embodiment”, “an embodiment” and so on, indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0138] It should be understood that, although the terms “first”, “second” and so on may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the disclosure. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed terms.

[0139] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. The terms “connect”, “connects”, “connecting” and / or “connected” used herein cover the direct and / or indirect connection between two elements. It should be noted that two blocks shown in succession in the above figures may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

[0140] The present disclosure includes any novel feature or combination of features disclosed herein either explicitly or any generalization thereof. Various modifications and adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with theaccompanying drawings. However, any and all modifications will still fall within the scope of the non-Limiting and exemplary embodiments of this disclosure.

Claims

Claims1. A method (500) performed at a network device, comprising: transmitting (205, 510), to a terminal device, a set of first reference signals at a first rate; and transmitting (215, 520), in at least one time duration and to the terminal device, one or more second reference signals for an activity associated with at least one of the terminal device or the network device.

2. The method (500) of claim 1, wherein a second reference signal comprises a synchronization signal, the synchronization signal comprises one or more of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and the PSS and the SSS are separated by a predetermined time interval.

3. The method (500) of claim 1, wherein the one or more second reference signals are transmitted prior to or during an occasion for the activity.

4. The method (500) of claim 1, further comprising: determining the number of second reference signals in the one or more second reference signals based on the activity.

5. The method (500) of claim 1, wherein the one or more second reference signals are of one type or of a plurality of types, and each type of the second reference signals corresponds to a type of terminal devices or the activity.

6. The method (500) of claim 1, wherein the at least one time duration is aperiodic or periodic.

7. The method (500) of claim 1, further comprising: transmitting, to the terminal device, first configuration information about at least one of: a length of a time duration, a periodicity of periodic time durations, the number of second reference signals in the time duration,a periodicity of the second reference signals in the time duration, a time offset of the time duration relative to a first reference signal, or a time offset relative to the activity.

8. The method (500) of claim 7, wherein the first configuration information is transmitted via at least one of:System Information Block (SIB) information, a Radio Resource Control (RRC) signaling, a Medium Access Control Control Element (MAC CE), or Downlink Control Information (DCI).

9. The method (500) of claim 1, further comprising: transmitting, to the terminal device and during one of the at least one time duration, second configuration information about at least one of: a reference signal burst occasion, the number of reference signal burst occasions within the time duration, a periodicity of the reference signal, or a length of the reference signal.

10. The method (500) of claim 1, wherein the set of first reference signals are associated with at least one of: cell evaluation, cell section, or cell reselection of the terminal device.

11. The method (500) of claim 1, further comprising: receiving, from the terminal device, capability information about whether the terminal device is capable of receiving both the set of first reference signals and the one or more second reference signals.

12. The method (500) of any of claims 1 to 11, wherein the activity comprises at least one of: paging, a random-access procedure, a system information transmission, a broadcast, or a multi-cast transmission.

13. A method (600) performed at a terminal device, comprising:receiving (210, 610), from a network device, a set of first reference signals transmitted at a first rate; and receiving (220, 620), in at least one time duration and from the network device, one or more second reference signals for an activity associated with at least one of the terminal device or the network device.

14. The method (600) of claim 13, wherein a second reference signal comprises a synchronization signal, the synchronization signal comprises one or more of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and the PSS and the SSS are separated by a predetermined time interval.

15. The method (600) of claim 13, wherein the one or more second reference signals are transmitted prior to or during an occasion for the activity.

16. The method (600) of claim 13, wherein the one or more second reference signals are of one type or of a plurality of types, and each type of the second reference signals corresponds to a type of terminal devices or the activity.

17. The method (600) of claim 13, wherein the at least one time duration is aperiodic or periodic.

18. The method (600) of claim 13, further comprising: receiving, from the network device, first configuration information about at least one of: a length of a time duration, a periodicity of periodic time durations, the number of second reference signals in the time duration, a periodicity of the second reference signals in the time duration, a time offset of the time duration relative to a first reference signal, or a time offset relative to the activity.

19. The method (600) of claim 18, wherein the first configuration information is received via at least one of:System Information Block (SIB) information,a Radio Resource Control (RRC) signaling, a Medium Access Control Control Element (MAC CE), or Downlink Control Information (DCI).

20. The method (600) of claim 13, further comprising: receiving, from the network device and during one of the at least one time duration, second configuration information about at least one of: a reference signal burst occasion, the number of reference signal burst occasions within the time duration, a periodicity of the reference signal, or a length of the reference signal.

21. The method (600) of claim 13, wherein the set of first reference signals are associated with at least one of: cell evaluation, cell section, or cell reselection of the terminal device.

22. The method (600) of claim 13, further comprising: transmitting, to the network device, capability information about whether the terminal device is capable of receiving both the set of first reference signals and the one or more second reference signals.

23. The method (600) of claim 13, further comprising: selecting a subset from the received set of the second reference signals based on a processing capability or a coverage of the terminal device.

24. The method (600) of claim 13, further comprising: determining whether a master information block (MIB) is present in the one or more second reference signals; and in accordance with a determination that the MIB is absent from the one or more second reference signals, obtaining a MIB from the set of the first reference signals.

25. The method (600) of any of claims 13 to 24, wherein the activity comprises at least one of: paging, a random-access procedure, a system information transmission, a broadcast, or a multi-cast transmission.

26. A network device (700) comprising: a processor (710) and a memory (720), the memory (720) containing instructions executable by the processor (710) whereby the network device is operative to perform a method (500) of any of claims 1-12.

27. A terminal device (700) comprising: a processor (710) and a memory (720), the memory (720) containing instructions executable by the processor (710) whereby the terminal device is operative to perform a method (600) of any of claims 13-25.

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