Network energy saving enhancement technology

Abstract

A method for a base station (BS) to broadcast one or more synchronization signal blocks (SSBs) is disclosed. The method includes transmitting a synchronization signal block (SSB) type indication to a user equipment (UE); and broadcasting the one or more synchronization signal blocks with a reduced number of antennas.

Description

[0001] Cross-references

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 532,506, filed August 14, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to network energy-saving enhancement technologies, and more specifically, to network energy-saving technologies for base stations (BS). Background Technology

[0004] According to a report released by the GSM Association (GSMA), energy costs for mobile networks account for approximately 23% of operators' total costs. Therefore, mobile network operators are increasingly interested in developing energy-saving methods to reduce operating expenses (OPEX).

[0005] For example, several network power-saving technologies have been proposed, such as asynchronous signal block secondary cells (SCells) for inter-band carrier aggregation (frequency domain), DTX / DRX adaptation (time domain), spatial and power domain adaptation, conditional handover (CHO) enhancement, and cell shielding enhancement. However, base stations (BSs) still require more network power-saving technologies. Summary of the Invention

[0006] In one aspect of this disclosure, a method is provided for a base station (BS) to broadcast one or more synchronization signal blocks (SSBs). The method includes sending a synchronization signal block (SSB) type indication to a user equipment (UE); and broadcasting the one or more synchronization signal blocks with a reduced number of antennas.

[0007] In another aspect of this disclosure, a method is provided for a user equipment to receive one or more synchronization signal blocks (SSBs). The method includes receiving a synchronization signal block type indication from a base station; and receiving the one or more synchronization signal blocks broadcast from the base station with a reduced number of antennas.

[0008] In another aspect of this disclosure, the base station broadcasts the one or more synchronization signal blocks with reduced power levels and a reduced number of antennas.

[0009] In another aspect of this disclosure, the user equipment, in response to the broadcast of a reduced power level of the one or more synchronization blocks, adjusts its beam measurement and reporting behavior according to the synchronization block type indication, including adjusting the Radio Link Monitoring (RLM) or Beam Failure Detection (BFD) threshold, calculating the cumulative power level of the multiple synchronization blocks, or compensating for the measured power of the synchronization blocks using a provided power offset value.

[0010] In another aspect of the disclosure, the one or more synchronization signal blocks are broadcasted by the base station at a reduced power level and at an extendable periodicity.

[0011] In another aspect of the disclosure, one or more physical broadcast channels of the one or more synchronization signal blocks are excluded to form a discovery reference signal for maintaining synchronization of a user equipment and providing coarse cell quality information to the user equipment, which can be used to trigger on-demand synchronization signal blocks (SSBs). The synchronization signal blocks are broadcasted by the base station at a reduced power level and at an extendable periodicity.

[0012] In another aspect of the disclosure, the base station implements an on-demand synchronization signal block (SSB) design functionality, in which transmission of synchronization signal blocks is not made if not triggered. This functionality can be used to further reduce power consumption when the cell is low or no load.

[0013] These and other features and advantages of the disclosure can be better understood in connection with the following embodiments, in conjunction with the figures. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Illustrating a base station broadcasting multiple synchronization signal and physical broadcast channel (SS / PBCH) blocks (SSBs) on different beams, consuming power at a first power level.

[0015] Figure 2 Illustrating a base station in a sleep mode, consuming power at a second power level.

[0016] Figure 3 Illustrating a base station broadcasting multiple synchronization signal blocks (SSBs), consuming power at a third power level.

[0017] Figure 4 Illustrating how a base station transmits information related to synchronization signal blocks to a user equipment in idle / inactive mode.

[0018] Figure 5 Illustrating how a base station transmits information related to synchronization signal blocks to a user equipment in connected mode.

[0019] Figure 6 Illustrating a method for a base station to broadcast one or more synchronization signal blocks (SSBs).

[0020] Figure 7 Illustrating a method for a user equipment to receive one or more synchronization signal blocks (SSBs). DETAILED DESCRIPTION

[0021] The present disclosure is not limited to the embodiments shown below, but rather the principles disclosed herein should be followed. Furthermore, various modifications or changes suggested to a person of ordinary skill are to be included within the spirit and scope of the present application and the appended claims.

[0022] Now referring to Figure 1 , the figure shows a base station (100) broadcasting one or more synchronization signals and physical broadcast channel (SS / PBCH) blocks (SSBs) at a first power level on different beams.

[0023] The base station (100) can periodically broadcast one or more SSBs, including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, and / or a PBCH demodulation reference signal (DM-RS), to serve multiple user equipments within the base station (100) cell.

[0024] The PBCH signal (or simply PBCH) can include a current system frame number (SFN) and an SSB time index of the base station (100) cell to facilitate time synchronization of the UE with the base station (100). The PBCH can also include a master information block (MIB) of one or more parameters. The UE can locate remaining minimum system information (RMSI) related to the cell according to the parameters of the MIB. The RMSI can include a system information block type 1 (SIB1). The SIB1 can include information for the UE to access the cell. Furthermore, the UE can monitor a PDCCH according to a parameter of the MIB, which can be used to schedule a PDSCH.

[0025] In the process of selecting a cell, the UE decodes the SIB1 of each detected cell. The UE camps on the cell selected by the selection mechanism according to the parameters contained in the SIB1 of each detected cell.

[0026] In the process of cell reselection, the UE has to decode the SIB1 transmitted by other cells it camps on because the UE previously camped on a cell. The other SIB1 can be transmitted on demand.

[0027] Furthermore, the SSBs can include a system information block type 2 (SIB2) to facilitate intra-frequency cell reselection and a system information block type 4 (SIB4) to facilitate inter-frequency cell reselection.

[0028] Back to Figure 1 , to achieve wider coverage of the base station (100), when the cell load is high, i.e. there are multiple UEs in the connected mode in the cell of the base station (100), the base station (100) can broadcast a set of SSBs in 4 beams pointing in different directions at a first power level in an SSB burst (such asFigure 1 The 4 SSBs in the SSB burst are transmitted by exploiting time-division multiplexing technique. It can be seen that if more beams are used to broadcast SSBs, the base station (100) will consume more power.

[0029] The UE receives the SSBs to synchronize in time and frequency with the cell of the base station (100). The UE can report measurements of reference signals related to one or more beams to the base station (100). For example, the UE can report measurements of reference signals related to the best beam or the top two best beams.

[0030] Now refer to Figure 2 , which shows the base station (100) in the dormant mode. To save power, when the cell load is empty, i.e. there is no UE or the UE is in idle / inactive state in the cell of the base station (100), the base station (100) can enter the dormant mode. When the base station (100) is in the dormant mode, it consumes power at a second power level, which is much lower than the first power level, to implement, for example, the on-demand SSB mechanism, which allows idle / inactive UEs, i.e. UEs in idle / inactive mode, to request SSBs when needed (see 3GPP Release 19 for details). In other words, during the on-demand SSB mechanism, no transmission of SSBs occurs if not triggered.

[0031] Now refer to Figure 3 , which shows the base station (100) broadcasting multiple SSBs at a third power level. To save power further, when the cell load is low, i.e. there are a small number of UEs in connected mode in the cell of the base station (100), the base station (100) can broadcast SSBs with a reduced number of antennas. As Figure 1 shown, when the cell load is high, the base station (100) broadcasts 4 SSBs using 4 antennas. In contrast, when the cell load is low, the base station (100) broadcasts 4 SSBs with a reduced number of antennas, e.g. using a single antenna or 2 antennas. In one case, the base station (100) can choose to broadcast the 4 SSBs in one or more wider beams. In another case, the base station (100) can choose to broadcast the 4 SSBs at a third power level, which is lower than the first power level and higher than the second power level, and with a reduced number of antennas. In another case, the base station (100) can choose to broadcast the 4 SSBs at the third power level in one or more wider beams.

[0032] The base station (100) can broadcast SSBs at the third power level with an extended periodicity. The PBCH in the SSBs can be excluded to form a discovery reference signal (DRS) for maintaining synchronization of the UE and providing coarse cell quality information to the UE, which can then be used to trigger on-demand SSBs.

[0033] User equipment (UE) receives a synchronization signal block (SSB) transmitted from base station (100) at a third power level. To avoid the UE potentially misinterpreting all received beams as faulty due to a low received beam power level, base station (100) needs to notify the UE in advance that the synchronization signal block is transmitted at a reduced power level (e.g., the third power level). In one scenario, the synchronization signal block type indication and / or configuration associated with the synchronization signal block (e.g., via System Information Block (SIB) or Radio Resource Control (RRC)) is transmitted from base station (100) to the UE before the synchronization signal block is broadcast. In another scenario, the synchronization signal block type indication and / or configuration associated with the synchronization signal block are transmitted from base station (100) along with the synchronization signal block, meaning the UE can distinguish whether the synchronization signal block is transmitted at a first or third power level upon receiving broadcast information from base station (100).

[0034] For user equipment, the above-mentioned configuration related to the synchronization signal block is transmitted from the base station (100) to the user equipment in idle / inactive mode via the system information block (SIB) and to the user equipment in connected mode via the radio resource control (RRC).

[0035] In addition, the synchronization signal block type indicates higher-layer information transmitted by the base station (100).

[0036] Furthermore, in one scenario, the synchronization block type indicator can be used to instruct the user equipment (UE) to adjust the Radio Link Detection (RLM) threshold or the Beam Failure Detection (BFD) threshold. The UE can adjust the RLM or BFD threshold based on the synchronization block type indicator. Therefore, if the threshold is lowered, the UE will not detect a link or beam failure.

[0037] Furthermore, the synchronization block type indicator can be used to request the user equipment to send measurement reports for multiple received beams associated with the synchronization block. In another case, the measurement report includes a cumulative power level calculated based on the power level of the synchronization block measured by the user equipment. Therefore, if several received power levels are accumulated, the user equipment will not determine that the beam is faulty and can estimate the optimal beam power through beamforming.

[0038] In this case, the aforementioned cumulative power level associated with the synchronization block can be calculated on multiple synchronization block occasions (SSB occasions) within a single synchronization block burst, or on multiple synchronization block occasions (SSB occasions) within multiple synchronization block bursts.

[0039] Furthermore, the synchronization block type indicator can be used to provide a power offset value for user equipment (UE) in connected mode. In another scenario, UE can use the power offset value for each beam to compensate for the power level of the received synchronization block. Therefore, if the power level is compensated, the UE will not detect a beam failure.

[0040] In this case, the user equipment can send a measurement report to the base station (100), which includes the measurement results based on the measured power of the synchronization signal block and the provided power offset value.

[0041] Furthermore, the Synchronization Signal Block Type Indicator can be used to instruct the user equipment to adjust the cell reselection threshold in the System Information Block (SIB), such as SIB1, SIB2, or any other SIB. The user equipment can adjust the reselection threshold according to the Synchronization Signal Block Type Indicator. Therefore, if the threshold is increased, the user equipment will not detect beam failure leading to unwanted cell reselection.

[0042] In summary, the base station (100) can instruct user equipment how to adjust its beam measurement and reporting behavior. For example, the base station (100) can perform any one or any combination of the following methods: (a) instructing user equipment to adjust the RLM threshold or BFD threshold; (b) requesting user equipment to report the cumulative power levels of multiple beams and estimate the optimal beam power through beamforming; and / or (c) providing a power offset value and requesting user equipment in connected mode to compensate for the power level of the received synchronization signal block measured by user equipment in connected mode.

[0043] Please see now Figure 4 This figure illustrates how a base station (100) transmits information related to synchronization signal blocks to a user equipment (200) in an idle / inactive mode. Figure 4 As shown, the base station (100) transmits a synchronization signal block type indication and / or configuration related to the synchronization signal block to the user equipment (200) via a System Information Block (SIB) (S410). The base station (100) then transmits the synchronization signal block type indication and / or configuration related to the synchronization signal block to the user equipment (200) via a System Information Block (SIB) (S420) after a predetermined time period. That is, the base station (100) periodically transmits the synchronization signal block type indication and / or configuration related to the synchronization signal block to the user equipment (200) in idle / inactive mode via a System Information Block (SIB), such as SIB1 or SIB2.

[0044] User equipment (200) in idle / inactive mode does not need to send measurement reports of received beams. User equipment (200) needs to adjust its beam measurement and / or reporting behavior according to the indication and / or configuration of the synchronization block type. For example, user equipment (200) may increase the cell reselection threshold in response to a synchronization block to reduce power level transmission. Specifically, user equipment (200) adjusts its beam measurement and / or reporting behavior according to the indication and / or configuration of the synchronization block type associated with S410 (S430). Furthermore, user equipment (200) further adjusts its beam measurement and / or reporting behavior according to the indication and / or configuration of the synchronization block type associated with S420 (S440).

[0045] Please see now Figure 5 This diagram illustrates how a base station (100) transmits information related to synchronization blocks to user equipment (200) in connected mode. User equipment in connected mode means they have successfully established a Radio Resource Control (RRC) connection with the network. Figure 5 As shown, the base station (100) transmits a synchronization block type indication and / or configuration related to the synchronization block to the user equipment (200) via Radio Resource Control (RRC) (S510).

[0046] In one scenario, the synchronization block type indicator and / or configuration notification to the user equipment (200) indicates that the synchronization block will be transmitted at a first power level. In this case, the base station (BS) (100) broadcasts the synchronization block to the user equipment (200) at the first power level (S520). The user equipment (200) then receives the synchronization block and measures the power level of the received synchronization block. The user equipment (200) then sends a measurement report of multiple beams associated with the synchronization block (S530). The measurement report indicates the optimal beam or the first two optimal beams.

[0047] In another scenario, the synchronization block type indication and / or configuration notifies the user equipment (200) that the synchronization block will be transmitted at a reduced power level, i.e., a third power level. In this case, in response to the synchronization block being transmitted at a reduced power level, the user equipment (200) needs to adjust its beam measurement and reporting behavior according to the synchronization block type indication and / or configuration (S540). For example, the user equipment (200) in connected mode may accordingly lower the thresholds for Radio Link Detection (RLM) and Beam Failure Detection (BFD), raise the threshold for cell reselection, or compensate for the power level with a power offset value to avoid inappropriate cell reselection. Furthermore, in this scenario, the base station (100) broadcasts the synchronization block to the user equipment (200) at the third power level (S520). The user equipment (200) then receives the synchronization block and measures the power level of the received synchronization block. The user equipment (200) then sends a measurement report of multiple beams associated with the synchronization block (S530). The measurement report of multiple beams associated with the synchronization signal block includes a cumulative power level calculated based on the power level of the synchronization signal block measured by the user equipment (200).

[0048] Given the above, base station behavior and user equipment behavior can be... Figure 6 and Figure 7 The explanation is as follows.

[0049] exist Figure 6 The present invention describes a method (600) for a base station to broadcast one or more synchronization signal blocks (SSBs). The method (600) includes sending a synchronization signal block type indication to a user equipment (step 610); and broadcasting the one or more synchronization signal blocks with a reduced number of antennas (step 620).

[0050] exist Figure 7 The present invention describes a method (700) for a user equipment to receive one or more synchronization signal blocks (SSBs). The method (700) includes receiving a synchronization signal block type indication from a base station (step 710); and receiving the one or more synchronization signal blocks broadcast from the base station with a reduced number of antennas (step 720).

[0051] Embodiments of the present invention have been described above. However, it will be readily recognized by those skilled in the art that the disclosure described above can be used in various devices, environments, and situations. Although the invention has been prepared with reference to specific embodiments and implementations, various changes and modifications may be proposed by those skilled in the art. It is intended that this disclosure cover such changes and modifications falling within the scope of the appended claims.

[0052] For example, those skilled in the art will understand that the device may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are used to perform the method according to the embodiments described above.

[0053] For example, a person with a general technical skill will understand that, despite the network power-saving techniques for the base station (BS) described above, user equipment (UE) can also save power accordingly. For instance, UE can be equipped with a low-power wake-up receiver (LP-WUR), which allows the UE to monitor only the wake-up receiver (WUR), thus keeping the main receiver (MR) in sleep mode and significantly saving UE power. More frequent measurement / accumulation of synchronization signal block power compared to the main receiver can further reduce UE power consumption. To maximize the benefits of the LP-WUR, the base station can further provide low-power paging indications and / or low-power synchronization signals so that the LP-WUR can operate for as long as possible, while the main receiver can be woken up when necessary.

[0054] For example, someone with a basic level of technical expertise would understand that even if a user equipment (UE) adjusts its beam measurement and beam reporting behavior according to synchronization block type indications to broadcast a reduced power level in response to one or more synchronization blocks, and then detects the reduced power level beam associated with one or more synchronization blocks, it will not function if the UE cannot transmit measurement reports on the uplink channel. To address this issue, it is possible to relax the measurement requirements under higher operating signal-to-noise ratio conditions.

Claims

1. A method for broadcasting one or more synchronization signal blocks at a base station, the method comprising: Send a synchronization signal block type indication to the user equipment; as well as The one or more synchronization signal blocks are broadcast with a reduced number of antennas.

2. The method of claim 1, wherein the base station broadcasts the one or more synchronization signal blocks at a reduced power level and a reduced number of antennas.

3. The method of claim 1, wherein the synchronization signal block type indicator indicates that the user equipment is adjusting the wireless link monitoring threshold or the beam failure detection threshold.

4. The method of claim 1, further comprising: Receive measurement reports of multiple beams associated with the one or more synchronization signal blocks, wherein the measurement reports include a cumulative power level calculated based on one or more power levels of the one or more synchronization signal blocks measured by the user equipment.

5. The method of claim 4, wherein the cumulative power level is calculated on one or more synchronization block occasions (SSB occasions) within a single synchronization block burst or multiple synchronization block bursts.

6. The method of claim 2, further comprising: Provide the power offset value to the user equipment.

7. The method of claim 6, further comprising: Receive the measurement results based on the measured power of the synchronization signal block and the provided power offset value.

8. The method of claim 1, wherein the synchronization signal block type indicator indicates the cell reselection threshold in the system information block (SIB).

9. The method of claim 1, further comprising: Implement the on-demand SSB design feature, where the transmission of the SSB will not occur if it is not triggered.

10. The method of claim 3, wherein the base station broadcasts the one or more synchronization signal blocks at a reduced power level and with an extended periodicity, and one or more physical broadcast channels of the one or more synchronization signal blocks are excluded to form a discovery reference signal for maintaining synchronization of user equipment and providing coarse cell quality information to the user equipment, which can be used to trigger on-demand synchronization signal blocks (SSBs).

11. A method for a user equipment (UE) to receive one or more synchronization signal blocks (SSBs), the method comprising: Receive synchronization signal block type indication from base station (BS); as well as Receive one or more synchronization signal blocks broadcast from the base station with a reduced number of antennas.

12. The method of claim 11, wherein the one or more synchronization signal blocks are broadcast from the base station with reduced power levels and reduced number of antennas.

13. The method of claim 11, wherein the synchronization signal block type indicator indicates that the user equipment is adjusting the wireless link monitoring threshold or the beam failure detection threshold.

14. The method of claim 11, further comprising: Send measurement reports of multiple beams associated with the one or more synchronization signal blocks, wherein the measurement reports include a cumulative power level calculated based on one or more power levels of the one or more synchronization signal blocks measured by the user equipment.

15. The method of claim 14, wherein the cumulative power level is calculated over one or more synchronization block occasions (SSB occasions) in a single synchronization block burst or multiple synchronization block bursts.

16. The method of claim 12, further comprising: Receive the power offset value sent from the base station.

17. The method of claim 16, further comprising: The measurement results are transmitted based on the measured power of the synchronization signal block and the received power offset value.

18. The method of claim 11, wherein the synchronization signal block type indicates the cell reselection threshold in the system information block (SIB).

19. The method of claim 11, further comprising: Implement the on-demand SSB design feature, where the transmission of the SSB will not occur if it is not triggered.

20. The method of claim 13, wherein the base station broadcasts the one or more synchronization signal blocks at a reduced power level and with an extended periodicity, and one or more physical broadcast channels of the one or more synchronization signal blocks are excluded to form a discovery reference signal for maintaining synchronization of user equipment and providing coarse cell quality information to the user equipment, which can be used to trigger on-demand synchronization signal blocks (SSBs).

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