Communication devices, methods, and system for network energy saving
Patent Information
- Application Number
- PCT/CN2025/084375
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2026-10-01
Smart Images
Figure CN2025084375_01102026_PF_FP_ABST
Abstract
Description
COMMUNICATION DEVICES, METHODS, AND SYSTEM FOR NETWORK ENERGY SAVINGTECHNICAL FIELD
[0001] The present disclosure generally relates to the field of communications technology. For instance, the present disclosure provides devices, methods, and a system for implementing network energy saving (NES) mechanism. For instance, it concerns a signalling mechanism among an anchor cell, an NES cell, and a terminal device for implementing on-demand synchronization signal block (OD-SSB) and on-demand system information block type 1 (OD-SIB1) signaling.BACKGROUND
[0002] The rapid evolution of wireless communication networks, particularly with the development of 5G and beyond, has significantly increased the demand for energy-efficient solutions. Modern networks are tasked with managing advanced services and applications, such as extended reality (XR) and ultra-reliable low-latency communications (URLLC) , which require extremely high data rates. This has led to denser network deployments, increased use of antennas, larger bandwidths, and more frequency bands. Consequently, controlling the environmental impact of these networks has become paramount for sustainable operations.
[0003] Energy consumption is a critical factor influencing the operational expenses (OPEX) of mobile network operators. According to industry reports, energy costs constitute approximately 23%of an operator’s total expenses, with the radio access network (RAN) contributing the largest share. The RAN’s power consumption can be divided into two categories. The first category is dynamic consumption, which occurs during active data transmission and reception. The second category is static consumption, which is needed to maintain the operational readiness of network devices even when no data transfer is occurring.
[0004] To address these challenges, the concept of Network Energy Saving (NES) has emerged as a critical objective. NES techniques aim to minimize both dynamic and static power consumption, thus reducing the carbon footprint and operational costs of wireless networks. Effective implementation of NES is essential for achieving the environmental sustainability goals of modern communication systems.SUMMARY
[0005] In conventional networks, base stations continuously broadcast system information, including synchronization signal blocks (SSBs) and system information blocks (SIBs) , to enable user equipment (UE) to perform cell search, selection, and mobility procedures.
[0006] 3GPP Release 19 introduces the notion of on-demand system information block type 1 (OD-SIB1) . Unlike conventional cells that constantly transmit SIB1, NES cells operate in an network energy saving mode by not constantly transmitting SIB1 and by providing OD-SIB1 when needed through an on-demand mechanism, such as upon UE request or upon decision of the network side.
[0007] While the OD-SIB1 transmission mechanism provides energy savings, the constant SSB transmission still consume considerable network energy.
[0008] The present disclosure addresses this challenge by extending the on-demand concept by introducing solutions to enable both SSB and SIB1 transmissions on demand, with or without using uplink wake-up signals. This objective is achieved by the subject matter of the independent claims. Further implementation forms are apparent from the dependent claims, the description, and the drawings.
[0009] A first aspect of the present disclosure provides a first network device configured to transmit, to a second network device, a triggering signal for initiating: OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission. The first network device is further configured to transmit, to a terminal device, indication information. The indication information indicates whether the second network device initiates OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.
[0010] It is noted that if the second network device does not initiate any of OD-SSB transmission and OD-SIB1 transmission, the indication information sent by the first network device to the terminal device may indicate that there is no on-demand transmission (no OD-SSB transmission and no OD-SIB1 transmission) from second network device. That is, in general, the indication information may be used to indicate one of the following activation status of on-demand transmission of the second network device: - no on-demand transmission; - OD-SSB transmission only; or - both OD-SSB and OD-SIB1 transmission.
[0011] In this way, a dynamic, on-demand provisioning of synchronization signals and system information can be achieved. The energy consumption of the second network device can be significantly reduced. By triggering the OD-SSB and / or the OD-SIB1 transmissions when required, the second network device can remain in low-power states during idle periods, contributing to overall network energy savings. The use of the indication information can enhance the efficiency of the terminal device by enabling the terminal device to selectively monitor and detect on-demand transmissions as indicated, reducing unnecessary power consumption at the terminal device side.
[0012] The first network device is associated with a primary cell or anchor cell. The second network device is associated with a network-energy saving cell, and is in a network-energy saving mode. The second network device does not constantly transmits its own SSB and SIB1. The first network device is, different from the second network device, not in a network-energy saving mode. The first network device constantly transmits its own SSB and SIB1. In the present disclosure, the SSB and SIB1 constantly provided (e.g., broadcast) by the first network device may be referred to as always-on SSB and always-on SIB1. The SSB and SIB1 provided (e.g., broadcast) by the second network device when required during a period of time may be referred to as OD-SSB and OD-SIB1.
[0013] The first network device may be configured to transmit indication information to the terminal device. The indication information indicates whether only OD-SSB transmission, or both of OD-SSB transmission and OD-SIB1 transmission is to be initiated or already initiated. If the second network device does not initiate any on-demand transmission (i.e., no OD-SSB and no OD-SIB1 transmission) , the indication information may indicate on on-demand transmission (e.g., request refused) . Optionally, different flags or different bit values may be used to indicate different activation status. For instance, a two-bit indication ‘00’ may indicate no transmission, ‘01’ may indicate OD-SSB transmission only, and ‘11’ may indicate both OD-SSB and OD-SIB1 transmission. This example is for illustration purposes only, any other suitable values or flags may be used.
[0014] In an implementation form of the first aspect, the first network device is configured to transmit, to the terminal device, a wake-up signal (WUS) configuration for enabling the terminal device to request OD-SSB transmission and / or OD-SIB1 transmission of the second network device; and receive, from the terminal device, a WUS indicating whether the terminal device requests OD-SSB transmission and / or OD-SIB1 transmission.
[0015] In response to the WUS indicating a request for OD-SSB transmission only, the first network device is configured to transmit a first signal as the triggering signal to the second network device to trigger OD-SSB transmission only.
[0016] In response to the WUS indicating a request for OD-SSB transmission and OD-SIB1 transmission, the first network device is configured to transmit a second signal as the triggering signal to the second network device to trigger both OD-SSB transmission and OD-SIB1 transmission.
[0017] In this way, the interaction between the first network device and the terminal device can be improved by allowing the terminal device to actively request on-demand transmissions, thus improving resource utilization and further optimizing network energy savings.
[0018] The WUS configuration transmitted by the first network device comprises at least one or more of the following information: - first WUS occasion parameters for sending a first UL WUS to the first network device; - second WUS occasion parameters for sending a second UL WUS to the second network device; - time window information of OD-SSB transmission of the second network device; and - time window information of OD-SIB1 transmission of the second network device.
[0019] The first WUS occasion parameters and the second WUS occasion parameters may be transmitted separately or in one signal.
[0020] The WUS occasion parameters may comprise time and frequency resources allocated for the terminal device to send the UL WUS. The time window information may comprise starting position, lengths, and periodicity of the time window.
[0021] Notably, the notions of “first UL WUS” and “second UL WUS” are used to distinguish different UL WUSs sent by the terminal device to the first network device and the second network device, respectively. For instance, if the terminal device sends a first UL WUS to the first network device requesting both OD-SSB and OD-SIB1, then the terminal device does not need to send a second UL WUS to the second network device. If the terminal device sends a first UL WUS to the first network device requesting only OD-SSB, then the terminal device can send a second UL WUS to the second network device requesting OD-SIB1. Similarly, the notions of “first WUS occasion parameters” and “second WUS occasion parameters” are used to distinguishing different WUS occasion parameters of the first network device and the second network device, respectively. Information comprising the first WUS occasion parameters may be referred to as “first WUS configuration” . Information comprising the second WUS occasion parameters may be referred to as “second WUS configuration” .
[0022] The WUS transmitted by the terminal device can be carried over physical channels such as PRACH, PUCCH, or PUSCH, depending on the state of the terminal device (idle, inactive, or connected) , thereby ensuring flexibility in different operational scenarios.
[0023] In a further implementation form of the first aspect, the indication information comprises acknowledgement information indicating whether the request indicated in the WUS is accepted (ACK) or not (NACK) .
[0024] In a further implementation form of the first aspect, the indication information is sent using random-access response (RAR) or downlink control information (DCI) .
[0025] Notably, the indication information is sent using the RAR if the WUS is sent by the terminal device using PRACH. The indication information is sent using the DCI if the WUS is sent by the terminal device using PUCCH or PUSCH.
[0026] In a further implementation form of the first aspect, the first network device is configured to transmit monitoring information to the terminal device for detecting OD-SSB transmission and / or OD-SIB1 transmission of the second network device.
[0027] In this case, there is no first UL WUS sent by the terminal device to the first network device. This may be because the first network device does not provide a valid WUS configuration to the terminal device. For instance, the first network device may either not provided a WUS configuration at all, or disable a previously provisioned WUS configuration, or a previously provisioned WUS configuration has expired and no new WUS configuration is provisioned. Therefore, the terminal device cannot send any UL WUS.
[0028] If the indication information indicates that the second network device initiates OD-SSB transmission only, then the monitoring information comprises information for detecting only OD-SSB from the second network device. If the indication information indicates that the second network device initiates both OD-SSB transmission and OD-SIB1 transmission, then the monitoring information comprises information for detecting both OD-SSB and OD-SIB1 from the second network device.
[0029] The monitoring information may be sent together with the indication information, or as part of the indication information.
[0030] In a further implementation form of the first aspect, the monitoring information comprises at least one or more of: - time window information (e.g., the starting position, length, periodicity, etc. ) for acquiring OD-SSB and / or OD-SIB1; and - radio network temporary identifier of the second network device.
[0031] Optionally, the monitoring information may further comprise second WUS occasion parameters for sending a second UL WUS to the second network device. In case that the first network device decides to trigger only OD-SSB for the terminal device, and intends to let the terminal device decide whether to trigger OD-SIB1 transmission, the first network device may be configured to provide, to the terminal device, the second WUS occasion parameters. According to the second WUS occasion parameters, the terminal device can request OD-SIB1 of the second network device by sending the second UL WUS to the second network device, if the terminal device decides to re-select to the second network device after acquiring OD-SSB of the second network device.
[0032] A second aspect of the present disclosure provides a second network device configured to: receive, from a first network device, a triggering signal for initiating: OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission; initiate, according to the triggering signal, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.
[0033] The second network device may share the corresponding features and advantages described above with the first network device of the first aspect.
[0034] In an implementation form of the second aspect, the second network device may be configured to receive, from the first network device, the triggering signal for initiating OD-SSB only. Accordingly, the second network device is configured to initiate OD-SSB transmission only. Then, the second network device may be configured to receive, from a terminal device, an UL WUS (i.e., the second UL WUS mentioned in the first aspect) for triggering the OD-SIB1 transmission. Accordingly, the second network device is configured to initiate OD-SIB1 transmission in response to receiving the second UL WUS from the terminal device.
[0035] A third aspect of the present disclosure provides a terminal device configured to receive, from a first network device, indication information indicating whether a second network device initiates OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission; and detect, from the second network device, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission in accordance with the indication information.
[0036] In an implementation form of the third aspect, the terminal device is configured to: - receive, from the first network device, a wake-up signal, WUS, configuration for requesting OD-SSB transmission or requesting OD-SSB and OD-SIB1 transmission from the second network device; and - send, to the first network device, a WUS requesting either OD-SSB transmission, or both OD-SSB transmission and OD- SIB1 transmission of the second network device.
[0037] In a further implementation form of the third aspect, the terminal device is configured to: - receive, from the first network device, monitoring information; and - detect OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission from the second network device in further accordance with the monitoring information.
[0038] If the indication information indicates that the second network device initiates OD-SSB transmission only, then the monitoring information comprises information for detecting only OD-SSB from the second network device. If the indication information indicates that the second network device initiates both OD-SSB transmission and OD-SIB1 transmission, then the monitoring information comprises information for detecting both OD-SSB and OD-SIB1 from the second network device.
[0039] For instance, the monitoring information may comprise at least one or more of: - time window information (e.g., the starting position, length, periodicity, etc. ) for acquiring OD-SSB and / or OD-SIB1 (depending on the activation status) ; and - radio network temporary identifier of the second network device.
[0040] In general, the indication information indicates what on-demand transmission is activated. The monitoring information indicates how to detect the activated on-demand transmission.
[0041] The terminal device may share the corresponding features and advantages described above with the first network device of the first aspect.
[0042] A fourth aspect of the present disclosure provides a system comprising a first network device according to the first aspect, and one or more second network devices according to the second aspect. The first network device is associated with the one or more second network devices. They cooperate with each other to implement a network energy saving mechanism.
[0043] It is noted that one first network device may be associated with (or cooperate with) a plurality of second network devices. The plurality of second network devices may be in a same NES cell, or in different NES cells. From cell point of view, a primary cell or anchor cell may be associated with (or cooperate with) a plurality of NES cells.
[0044] A fifth aspect of the present disclosure provides a method applied to a first network device. The method comprises the following steps: - transmitting, to a second network device, a triggering signal for initiating: OD-SSB, transmission only, or both OD-SSB transmission and OD-SIB1 transmission; and - transmitting, to a terminal device, indication information indicating whether the second network device initiates OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.
[0045] The method of the fifth aspect may share the same features and advantages as described above with the first network device of the first aspect.
[0046] A sixth aspect of the present disclosure provides a method applied to a second network device. The method comprises the following steps: - receiving, from a first network device, a triggering signal for initiating: OD-SSB transmission only, or both ON-SSB transmission and OD-SIB1 transmission; - initiating, according to the triggering signal, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.
[0047] The method of the sixth aspect may share the corresponding features and advantages as described above with the first network device of the first aspect.
[0048] A seventh aspect of the present disclosure a method applied to a terminal device. The method comprises the following steps: - receiving, from a first network device, indication information indicating whether a second network device initiates OD- SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission; and - detecting, from the second network device, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission in accordance with the indication information.
[0049] The method of the seventh aspect may share the corresponding features and advantages as described above with the first network device of the first aspect.
[0050] An eighth aspect of the present disclosure provides a computer program (product) comprising a program code for performing the method according to the fifth aspect, the sixth aspect, or the seventh aspect.
[0051] A ninth aspect of the present disclosure provides a non-transitory storage medium storing executable program code which, when executed by a processor (or a chipset) , causes the method according to the fifth aspect, the sixth aspect, or the seventh aspect to be performed.
[0052] It has to be noted that all devices, elements, units and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of the present disclosure, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The above-described aspects and implementation forms will be explained in the following description in relation to the enclosed drawings, in which
[0054] FIG. 1 shows an example timeline of a first network and a second network device;
[0055] FIG. 2 shows a further example timeline of a first network and a second network device;
[0056] FIG. 3 shows a signaling diagram according to the present disclosure; and
[0057] FIG. 4 shows a further signaling diagram according to the present disclosure.DETAILED DESCRIPTION
[0058] A list of key terms and their acronyms / abbreviations used in the present disclosure is given as follows: 3rd Generation Partnership Project -3GPP; Base Station –BS; Downlink Control Information -DCI; Downlink –DL; gNodeB –gNB; New Radio –NR; On-Demand –OD; Orthogonal Frequency-Division Multiplexing –OFDM; Physical broadcast channel -PBCH; Physical Downlink Control Channel –PDCCH; Physical Downlink Shared Channel -PDSCH; Physical Random Access Channel –PRACH; Network Energy Saving –NES; Random Access –RA; Random Access Response–RAR; Radio Resource Control –RRC; System Information Block –SIB; System Information Block Type 1 –SIB1; Uplink –UL; User Equipment –UE; Wake Up Signal -WUS.
[0059] It is noted that SSB may correspond to Synchronization Signal Block, or Synchronization Signal / PBCH block.
[0060] The present disclosure provides improvements in implementing network energy saving measures for mobile communications.
[0061] FIG. 1 shows an example timeline of a first network (Cell A) and a second network device (NES Cell) .
[0062] The first network device is associated with a primary cell or anchor cell (Cell A) . The first network device is not in a network energy saving mode and therefore, constantly transmit its SSB and SIB1. In the present disclosure, term “Cell A” may be used to refer to the first network device. The SSB and SIB1 that are constantly broadcast by the Cell A may be referred to as “always-on SSB” and “always-on SIB1” .
[0063] The second network device is associated with an NES Cell, and thus, is in a network energy saving mode. The second network device does not constantly transmit its SSB and SIB1, but only transmits its SSB and SIB1 when needed (e.g., upon request or upon its own decision) . In the present disclosure, term “NES Cell” may be used to refer to the second network device. The SSB and SIB1 that are broadcast by the NES Cell in an on-demand manner may be referred to as “OD-SSB” and “OD-SIB1” .
[0064] In general, the present disclosure provides a mechanism that allows the Cell A to trigger only OD-SSB transmission, or both OD-SSB and OD-SIB1 transmission of the NES Cell for a terminal device (referred to as a UE) . That is, the Cell A is configured to send a triggering signal to the NES Cell. The triggering signal is used to request the NES Cell to initiate OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission. The Cell A is also configured to send indication information to the UE. The indication information is used to indicate whether the second network device initiates OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.
[0065] The triggering mechanism may be based on at least two solutions: WUS-based solution in the Cell A, and non-WUS-based solution in the Cell A.
[0066] In WUS-based solution, the UE is configured to send an UL WUS to the Cell A.
[0067] For sending the UL WUS, the UE may be configured to obtain a WUS configuration from the Cell A. The WUS configuration may indicate an WUS occasion during which the UE is allowed to send the UL WUS to request on-demand transmission (s) .
[0068] The UL WUS may request only OD-SSB transmission of the NES Cell, or both OD-SSB transmission and OD-SIB1 transmission of the NES Cell. Accordingly, the Cell A is configured to send a respective triggering signal to the NES Cell to request the same transmission indicated in the UL WUS.
[0069] Alternatively, the UL WUS may request only OD-SSB transmission of the NES Cell. Accordingly, the Cell A is configured to request only OD-SSB transmission of the NES Cell. In this case, the OD-SIB1 transmission may be requested directly by the UE itself, e.g., after the UE acquires SSB of the second network device and decides to re-select to the NES Cell. For directly requesting the OD-SIB1 transmission, the UE transmit an UL WUS directly to the NES Cell after acquiring SSB from the NES Cell.
[0070] Optionally, the indication information may be sent using an RAR if the UL WUS is sent by the UE using PRACH. Alternatively, the indication information may be sent using DCI if the UL WUS is sent by the UE using PRACH or PUCCH or PUSCH.
[0071] In non-WUS-based solution, the UE does not send any UL WUS to the Cell A (not shown in FIG. 1) . In this case, the UE does not have a valid WUS configuration. For instance, the UE does not obtain any WUS configuration from the Cell A at all; or a previously provisioned WUS configuration has expired; or the Cell A promptly disables a previously provisioned WUS configuration for the UE. In any case, the UE cannot send any UL WUS to the Cell A. The Cell A is configured to decide which on-demand transmission of the NES Cell to be triggered for the UE, and notify its decision to the UE accordingly. Therefore, the WUS triggering depicted in FIG. 1 is optional.
[0072] In both solutions, as shown in FIG. 1, the NES Cell is configured to broadcast its OD-SSB and OD-SIB1 in respective time window. The time window during which OD-SSB is transmitted may be referred to as OD-SSB window. The time window during which OD-SIB1 is transmitted may be referred to as OD-SIB1 window. The OD-SSB window and the OD-SIB1 window may be the same or different. Information on the OD-SSB window and the OD-SIB1 window (e.g., the starting position, length, periodicity, etc. ) of the NES Cell may be sent by the Cell A to the UE.
[0073] It is noted that during the OD-SIB1 window, the NES Cell may be configured to: - stop broadcasting OD-SSB, or - continue broadcasting OD-SSB.
[0074] Stopping broadcasting OD-SSB during the OD-SIB1 window may further reduce network power consumption. Continuing broadcasting OD-SSB during the OD-SIB1 window may improve UE performance in accessing the NES Cell, increasing successful cell access chance for the UE and / or improving the measurements of the UEs camping on the NES Cell.
[0075] FIG. 2 shows a further example timeline of a first network (Cell A) and a second network device (NES Cell) .
[0076] Based on the example shown in FIG. 1, FIG. 2 shows specifically that the Cell A is configured to trigger only OD-SSB transmission of the NES Cell. In this case, the UE may request only OD-SSB transmission of the NES Cell through the UL WUS sent to the Cell A (as shown in FIG. 2) , or the Cell A decides that only OD-SSB transmission of the NES Cell is appropriate for the UE.
[0077] After receiving the triggering signal requesting only OD-SSB transmission, the NES Cell is configured to initiate OD-SSB transmission. The UE is configured to acquire one or more SSBs from the NES Cell. The acquired SSB (s) may be used by the UE for cell synchronization and measurement, which may help the UE in deciding whether to re-select to the NES Cell. If the UE decides to re-select to the NES Cell, the UE is configured to send an UL WUS to the NES Cell. To distinguish the UL WUS sent to the Cell A, the UL WUS sent to the NES Cell is referred to as a second UL WUS; the UL WUS sent to the Cell A is referred to as a first UL WUS. The second UL WUS is used to trigger the NES Cell to initiate OD-SIB1 transmission, so that the UE can camp on the NES Cell. The second UL WUS may be sent using PRACH. In response to receiving the UL WUS, the NES Cell may be configured to send an RAR or DCI for acknowledging the UL WUS.
[0078] This is particularly helpful in cases where the UE determines that the Cell A is not suitable for camping. The UE can request SSBs of surrounding cells to see if any of them is more suitable than the Cell A. When the UE finds such a suitable NES Cell, the UE can trigger OD-SIB1 and re-select to it. This mechanism can save more network energy, since whether OD-SIB1 transmission of the NES Cell is initiated or not is based on UE measurement. This can avoid un-necessary OD-SIB1 transmission, as sometimes the UE may decide not to re-select to the NES Cell after cell measurement based on SSB from the NES Cell. On the other hand, when both OD-SSB and OD-SIB1 transmissions are requested, the UE can timely access the NES Cell, as it is not necessary for the UE to separately request OD-SIB1 transmission. Cell re-selection delay can be reduced.
[0079] In general, whether to request OD-SSB only, or both OD-SSB and OD-SIB1 depends on specific application scenario, traffic type, and UE capability.
[0080] FIG. 3 shows a signaling diagram of a system.
[0081] The system comprises a first network device 310 (or Cell A) , and a second network device 320 (or NES Cell) . The system may further comprise at least one terminal device 330 (or UE) . It shall be noted that the number of the first network device, the second network device, the terminal device is not limited in the system. For instance, one first network device may be associated with one or more second network devices; one or more terminal devices may be camped on one first network device. For simplicity, the signaling diagram is described with respect to one first network device 310, one terminal device 320, and one second network device 330.
[0082] The signaling of FIG. 3 is based on the timeline of FIG. 1. Therefore, features disclosed with respect to FIG. 1 and FIG. 3 may be combined. The signaling of FIG. 3 may involve the following steps.
[0083] In Step 31, the UE 330 may be configured to send an UL WUS to the Cell A 310. The UL WUS requests both OD-SSB and OD-SIB1 transmissions of the NES Cell 320.
[0084] When the UE 330 is camped on the Cell A 310, the UE may receive multiple configurations informing the existence of surrounding NES Cells (e.g., their PCIs and frequencies, etc. ) . These configurations may be provided in SIBx of the Cell A (where x=1, 2, 3, 4 etc., indicating a specific type of the SIB) . The UE may receive corresponding WUS configurations to trigger either OD-SSB or OD-SIB1. When the UE is in idle or inactive state, the resources for sending UL WUS may be PRACH, Msg3, or the like. The UE may receive RAR window and / or reception parameters for receiving a response to the UL WUS.
[0085] When the UE 330 is connected mode with the Cell A 310, the UE may receive further configurations, which allows the UE to send UL WUS in connected mode. In this case, the UL WUS may be carried by PUCCH, PUSCH, or SRS, etc. In the case of FIG. 3, the UL WUS sent by the UE 330 to the Cell A 310 is used to request both OD-SSB and OD-SIB1 transmissions of the NES Cell 320.
[0086] This could be useful for some situations. For instance, when the UE 330 is about to lose connection with the Cell A 310 and before the loss of connection, the UE 330 can trigger both OD-SSB and OD-SIB1 transmission of an existing NES Cell, in order to timely camp on this NES Cell.
[0087] Step 31 is optional, as in non-WUS-based solution, it is also possible that the Cell A 310 can decide to trigger both OD-SSB and OD-SIB1 transmissions of the NES Cell 320 for the UE 330.
[0088] In Step 32, the Cell A 310 is configured to send a triggering signal to the NES Cell 320. The triggering signal is used to trigger the NES Cell 320 to initiate both OD-SSB and OD-SIB1 transmissions.
[0089] In Step 33, the NES Cell 320 may be configured to send acknowledgment information to the Cell A 310. The acknowledgment information may indicate whether the triggering signal is accepted or not.
[0090] Step 33 is optional, as it is not required in non-WUS-based solution.
[0091] In Step 34, the Cell A 310 is configured to send notification information to 330. The notification information indicates that the NES Cell initiates both OD-SSB and OD-SIB1 transmissions.
[0092] The notification information may be sent using DCI, such as group common DCI.
[0093] Optionally, the Cell A 310 may be configured to send acknowledgement information (ACK or NACK) of the request in the UL WUS sent in Step 31. The acknowledgement information may be sent using RAR.
[0094] In general, the UE 330 is informed about the acceptance of its request (if UL WUS is sent in Step 31) and / or about the availability of OD-SSB and / or OD-SIB1 transmissions of the NES Cell.
[0095] The acceptance of the request can be carried by an RAR in case the UL WUS is sent using PRACH, or by PDSCH / PDCCH in case the UL WUS is sent using PRACH / PUSCH / PDCCH.
[0096] The availability of OD-SSB and / or OD-SIB1 in the next one or more windows could be carried by a group common DCI to inform all the UEs camping or connecting to Cell A about the availability of OD-SSB and / or OD-SIB1 from one or more NES cells.
[0097] In Step 35, the NES Cell 320 is configured to broadcast OD-SSB and OD-SIB1 in respective time window.
[0098] In Step 36, the UE 330 is configured to acquire OD-SSB and OD-SIB1 of the NES Cell 320. For instance, the UE is configured to perform cell synchronization and measurement based on OD-SSB, and detect OD-SIB1, so as to camp on the NES Cell 320.
[0099] FIG. 4 shows a further signaling diagram of a system. The composition of the system in FIG. 4 is the same as the system in FIG. 3, which are not repeated herein.
[0100] Different from FIG. 3, the Cell A 310 is configured to send a triggering signal for initiating only OD-SSB transmission of the NES Cell 320 in Step 42. This may be because the UE 330 requests only OD-SSB transmission in Step 41, or the Cell A 310 makes this decision for the UE 330 without receiving any UL WUS from the UE 330. Other than this difference, Steps 41-44 may be built based on Steps 31-34, and share the same features as Steps 31-34.
[0101] In some cases, it may be beneficial for the UE 330 to send UL WUS to the Cell A 310 to trigger OD-SSB before switching to the NES Cell 320 to use UL WUS to trigger OD-SIB1. For instance, the UE 330 could start to see that Cell A measurements indicate that the Cell A 310 is close to not being suitable for camping on. In this case, the UE 330 could request for OD-SSBs of surrounding NES Cells to see if any NES Cell is more suitable than the Cell A 310 to camp on. This decision can also be made by the Cell A. When the UE 330 find such a suitable NES cell, it can decide to re-select to it and then trigger OD-SIB1.
[0102] If the UE 310 cannot find any suitable NES cell to camp on, then OD-SIB1 will not be triggered (e.g., the following Steps 47-49 are not performed, and the UE 330 is still camped on the Cell A 310) . In this case, the NES cell can still saving part of its energy (by not providing OD-SIB1) .
[0103] In Step 45, the NES Cell 320 is configured to broadcast only OD-SSB during the OD-SSB window.
[0104] In Step 46, the UE 330 is configured to acquire OD-SSB from the NES Cell 320.
[0105] In this case, the UE may be configured to perform cell measurement based on the OD-SSB of the NES Cell 320, and optionally, report cell measurement to the Cell A 310.
[0106] In Step 47: the UE 330 is configured to send an UL WUS to the NES Cell 320. The UL WUS is used to trigger OD-SIB1 of the NES Cell 330.
[0107] Necessary information for sending the UL WUS to the NES Cell 320 may be provisioned by the Cell A 310.
[0108] In Step 48: The NES Cell 320 is configured to broadcast OD-SIB1 during the OD-SIB1 window.
[0109] It is noted that during the OD-SIB1 window, the NES Cell 320 may be configured to: - stop broadcasting OD-SSB, or - continue broadcasting OD-SSB.
[0110] In Step 49: The UE 330 is configured acquire OD-SIB1 from the NES Cell, so as to camp on the NES Cell 320.
[0111] The present disclosure may be applied to any telecommunications networks / systems, such as but not limited to 5G (or NR) and the like. The network devices and the terminal device in this disclosure each may comprise processing circuitry or a chipset (not shown) configured to respectively perform, conduct, or initiate the various operations described herein. The processing circuitry may comprise hardware and software. The hardware may comprise analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs) , field-programmable arrays (FPGAs) , digital signal processors (DSPs) , or multi-purpose processors. Optionally, the processing circuitry (or the chipset) comprises one or more processors and a non-transitory memory connected to the one or more processors. The non-transitory memory may carry executable program code which, when executed by the one or more processors, causes the devices to perform, conduct or initiate the operations or methods described herein.
[0112] The present invention has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed invention, from the studies of the drawings, this disclosure, and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.
Claims
1.A first network device (310) configured to:transmit, to a second network device (320) , a triggering signal for initiating: on-demand synchronization signal block, OD-SSB, transmission only, or both OD-SSB transmission and on-demand system information block type 1, OD-SIB1, transmission; andtransmit, to a terminal device (330) , indication information indicating whether the second network device (320) initiates OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.2.The first network device (310) according to claim 1, configured to:transmit, to the terminal device (330) , a wake-up signal, WUS, configuration for enabling the terminal device (330) to request OD-SSB transmission and / or OD-SIB1 transmission of the second network device (320) ;receive, from the terminal device (330) , a WUS indicating whether the terminal device (330) requests OD-SSB transmission and / or OD-SIB1 transmission;in response to the WUS indicating a request for OD-SSB transmission only, transmit a first signal as the triggering signal to the second network device (320) to trigger OD-SSB transmission only;in response to the WUS indicating a request for OD-SSB transmission and OD-SIB1 transmission, transmit a second signal as the triggering signal to the second network device (320) to trigger both OD-SSB transmission and OD-SIB1 transmission.3.The first network device (310) according to claim 2, wherein the indication information comprises acknowledgement information indicating whether the request indicated in the WUS is accepted or not.4.The first network device (310) according to claim 3, wherein the indication information is sent using random-access response or downlink control information.5.The first network device (310) according to claim 1, wherein the first network device (310) is configured to transmit monitoring information to the terminal device (330) for detecting OD-SSB transmission and / or OD-SIB1 transmission of the second network device (320) .6.The first network device (310) according to claim 5, wherein the monitoring information comprises one or more of:- time window information for acquiring SSB and / or SIB; and- radio network temporary identifier of the second network device (320) .7.A second network device (320) configured to:receive, from a first network device (310) , a triggering signal for initiating: on-demand synchronization signal block, OD-SSB, transmission only, or both OD-SSB transmission and on-demand system information block type 1, OD-SIB1, transmission; andinitiate, according to the triggering signal, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.8.A terminal device (330) configured to:receive, from a first network device (310) , indication information indicating whether a second network device (320) initiates on-demand synchronization signal block, OD-SSB transmission only, or both OD-SSB transmission and on-demand system information block type 1, OD-SIB1, transmission; anddetect, from the second network device (320) , OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission in accordance with the indication information.9.The terminal device (330) according to claim 8, configured toreceive, from the first network device (310) , a wake-up signal, WUS, configuration for requesting OD-SSB transmission and / or OD-SIB1 transmission of the second network device (320) ; andsend, to the first network device (310) , a WUS requesting either OD-SSB transmission, or both OD-SSB transmission and OD-SIB1 transmission of the second network device (320) .10.The terminal device (330) according to claim 8, configured toreceive, from the first network device (310) , monitoring information; anddetect OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission from the second network device (320) in further accordance with the monitoring information.11.A system comprising a first network device (310) according to any one of claims 1 to 6, one or more second network devices (320) according to claim 7.12.A method applied to a first network device, the method comprising:transmitting (32, 42) , to a second network device, a triggering signal for initiating: on-demand synchronization signal block, OD-SSB, transmission only, or both OD-SSB transmission and on-demand system information block type 1, OD-SIB1, transmission; andtransmitting (34, 44) , to a terminal device, indication information indicating whether the second network device initiates OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.13.A method applied to a second network device, the method comprising:receiving (32, 42) , from a first network device, a triggering signal for initiating: on-demand synchronization signal block, OD-SSB, transmission only, or both OD-SSB transmission and on-demand system information block type 1, OD-SIB1, transmission;initiating (35, 45, 48) , according to the triggering signal, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission.14.A method applied to a terminal device, the method comprising:receiving (34, 44) , from a first network device, indication information indicating whether a second network device initiates on-demand synchronization signal block, OD-SSB, transmission only, or both OD-SSB transmission and on-demand system information block type 1, OD-SIB1, transmission; anddetecting (36, 46, 49) , from the second network device, OD-SSB transmission only, or both OD-SSB transmission and OD-SIB1 transmission in accordance with the indication information.15.A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to any one of claims 12 to 14.