Synchronization signal block (SSB) operation enhancement in non-terrestrial network (NTN) enhancement
The implementation of band-specific and region-specific SSB periodicity mechanisms and explicit SSB indications in NTN networks addresses synchronization challenges, enhancing UE access and handover efficiency by aligning SSB periodicity with network configurations.
Patent Information
- Application Number
- PCT/CN2024/111059
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2026-02-12
AI Technical Summary
Existing wireless communication systems face inefficiencies in initial access, handover, and RRC redirection processes due to unclear or unsupported SSB periodicity assumptions in non-terrestrial networks (NTN), leading to synchronization failures and access issues for user equipment (UEs) in scenarios where SSB periodicity deviates from the default 20ms.
Implementing a band-specific and region-specific SSB periodicity mechanism for UEs, where predefined mappings in datasets associate NTN bands or regions with various SSB periodicities, allowing UEs to perform cell searches and synchronizations based on these predefined associations, and enabling explicit SSB periodicity indications in handover and RRC redirection commands.
Enhances UE synchronization and access efficiency in NTN networks by reducing initial access failures and improving handover and RRC redirection success rates through tailored SSB periodicity adjustments, ensuring seamless communication across different satellite constellations and beam patterns.
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Figure CN2024111059_12022026_PF_FP_ABST
Abstract
Description
SYNCHRONIZATION SIGNAL BLOCK (SSB) OPERATION ENHANCEMENT IN NON-TERRESTRIAL NETWORK (NTN) ENHANCEMENTFIELD
[0001] The present disclosure is related to wireless technology and synchronization signal block (SSB) enhancements with non-terrestrial network enhancements.BACKGROUND
[0002] Non-terrestrial networks include communication nodes that are located above the earth’s surface. These nodes may orbit the earth, or move over some region of the earth. Mobile communication in the next generation wireless communication system, 5G, or new radio (NR) network will provide ubiquitous connectivity and access to information, as well as ability to share data, around the globe. For example, some wireless communication networks (e.g., fifth generation (5G) or new radio (NR) networks) may be developed to include non-terrestrial networks (NTN) comprising one or more satellites. In such scenarios, the satellites may operate as transparent network nodes linking user equipment (UEs) with a ground-based portions of the network, such as base stations and core network (CN) .BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 illustrates an example non-terrestrial network (NTN) configuration for a synchronization signal block (SSB) enhancement in accordance with various aspects.
[0004] FIG. 2 illustrates another example NTN configuration for SSB enhancement for initial access in accordance with various aspects.
[0005] FIG. 3 illustrates another example NTN configuration for SSB enhancement for initial access in accordance with various aspects.
[0006] FIG. 4 illustrates an example process flow for NTN SSB enhancement for initial access operations in accordance with various aspects or examples.
[0007] FIG. 5 illustrates another example process flow for NTN SSB enhancement for initial access operations in accordance with various aspects or examples.
[0008] FIG. 6 illustrates another example process flow for NTN SSB enhancement for initial access operations in accordance with various aspects or examples.
[0009] FIG. 7 illustrates another example process flow for NTN SSB enhancement for initial access operations in accordance with various aspects or examples.
[0010] FIG. 8 illustrates another example NTN configuration for SSB enhancement in handover (HO) in accordance with various aspects.
[0011] FIG. 9 illustrates another example process flow for NTN SSB enhancement operations in HO in accordance with various aspects or examples.
[0012] FIG. 10 illustrates another example process flow for NTN SSB enhancement operations in HO in accordance with various aspects or examples.
[0013] FIG. 11 illustrates another example process flow for NTN SSB enhancement operations in HO in accordance with various aspects or examples.
[0014] FIG. 12 illustrates another example process flow for NTN SSB enhancement operations in HO in accordance with various aspects or examples.
[0015] FIG. 13 illustrates another example NTN configuration for SSB enhancement in radio resource control (RRC) redirection in accordance with various aspects.
[0016] FIG. 14 illustrates another example NTN configuration for SSB enhancement in RRC redirection in accordance with various aspects.
[0017] FIG. 15 illustrates another example NTN configuration for SSB enhancement RRC redirection in accordance with various aspects.
[0018] FIG. 16 illustrates another example NTN configuration for SSB enhancement RRC redirection in accordance with various aspects.
[0019] FIG. 17 illustrates an exemplary block diagram illustrating an example of UEs communicatively coupled in a NTN network with network components as peer devices useable in connection with various aspects described herein.
[0020] FIG. 18 illustrates an example simplified block diagram of a UE wireless communication device or other network device / component (e.g., NTN satellite, base station, eNB, gNB) in accordance with various aspects.DETAILED DESCRIPTION
[0021] The following detailed description refers to the accompanying drawings. Like reference numbers in different drawings may identify the same or similar features, elements, operations, etc. Additionally, the present disclosure is not limited to the following description as other implementations may be utilized, and structural or logical changes made, without departing from the scope of the present disclosure.
[0022] Various enhancements include the system level and the link level for downlink (DL) coverage targeting support of additional reference satellite parameters covering both geosynchronous orbit (GSO) and non-geostationary orbits (NGSO) constellations operating in frequency range 1 (FR1) –non-terrestrial network (NTN) or frequency range 2 (FR2) -NTN. Aspects include link level and system level enhancements for FR1-NTN / FR2-NTN to enable dynamic and flexible power sharing between satellite beams or different satellite beam patterns / sizes (i.e., wide or narrow) across a satellite beam footprint.
[0023] At the link level enhancements various physical channels / signals can operate with support from the system level enhancements, in particular for an extension of the synchronization signal block (SSB) periodicity, such as with SSB values beyond past releases. Aspects herein address issues that may arise to support the extension of the SSB periodicity with NTN operations that may impact the initial cell selection in an initial access procedure as the process between a user equipment (UE) and a satellite NTN or NTN base station for the UE to acquire uplink synchronization and obtain specified ID (s) for radio access communication; also referred to as a random access channel (RACH) process. In particular, the current initial access for cell selection at the UE is defined such that the UE can be provided per cell by a periodicity parameter (e.g., SSB-periodicityServingCell) of half frames for reception of the synchronization signal (SS) / physical broadcast channel (PBCH) blocks for a serving cell. If the UE is not configured a periodicity of the half frames for reception of the SS / PBSCH (SSB) blocks, the UE assumes a periodicity of a half frame. The UE can assume that the periodicity is a same for all SSB blocks in the serving cell. In particular, for an initial cell selection, the UE may assume that half frames with SSB blocks occur with a periodicity of 2 frames, with the SSB periodicity of 20 milliseconds (ms) (a legacy SSB periodicity) by default.
[0024] The NTN UE can attempt to perform an initial access to the NTN with an SSB periodicity of 20ms. However, if a Release 19, or beyond, NTN network modifies or changes the SSB periodicity to be different from 20ms (e.g., greater than 20ms) an initial access failure could occur in UEs configured for earlier releases of an NTN (e.g., Release 17 or 18 NTN UEs) . Moreover, even for Release 19 or beyond NTN UEs, it is not clear whether the network behavior is currently following any particular release (Release 17 / 18 or Release 19) , and the UE behavior remains unclear for implementation during the initial access when the UE is in a radio resource control (RRC) idle mode or inactive mode, as well as for handover (HO) operation and a radio resource control (RRC) connection release with redirection to new radio (NR) operation, when the UE is in an RRC connected mode of a serving cell.
[0025] As mentioned above, in addition to the initial access, other UE behaviors can demand that the UE assume a by-default or legacy SSB periodicity in previous networks (Rel-17 / 18) . For example, for a handover or a conditional handover (conditional HO) , when the UE is not provided a SSB based measurement timing configuration (SMTC) or a measurement object on a carrier frequency, the UE applies a legacy timing of a reference signal (Trs) that is 5ms by assuming that the SSB transmission periodicity is 5ms. However, if the SSB periodicity for transmission is not 5ms, the UE is not necessarily able to synchronize with a target cell.
[0026] In another example, for a RRC connection release with redirection to NR, when the UE is not provided with a SMTC configuration or a measurement object for a carrier frequency in the RRC connection release, the UE can apply a legacy SSB transmission periodicity not larger than 20ms. However, if the SSB periodicity for transmission is not 20ms, the UE may not be able to synchronize with a target frequency carrier of the cell.
[0027] A SSB refers to a synchronization signal (SS) / physical broadcast channel (PBCH) block information. The SSB contains the primary synchronization signal (PSS) and the secondary synchronization signal (SSS) for synchronization as an initial action to access the NW. The SSB provides the timing and frequency synchronization for the cell, also containing the PBCH that includes the master information block (MIB) . The MIB further includes information broadcast in the NW cell regarding the cell configuration and other information for wireless communication with the base station. The system information block 1 (SIB1) or other SIBS can include other important information for NW operation that contains the physical random access channel (PRACH) configuration information element (IE) , and other information for a Random Access (RA) channel procedure to attach or connect to the NW and request uplink (UL) resources to send data, for example. However, the SSB / SIB1 transmission are performed with a periodicity or periodically. The SSB periodicity for enabling initial access, for example, can be at about 20ms, while the SIB1 is being transmitted by the NW with different periodicities such as 40ms, 80ms, 160ms, 320ms, etc., for example. If the UE is not aware of an extended SSB (e.g., 40ms, 80ms, 160ms, 320ms, etc. ) , the UE potentially may not be able to adequately be able to perform a cell search in an initial access or discover important system information for handover to a target cell or RRC redirection to a target carrier frequency in the NTN cell.
[0028] Various aspects herein address the above inefficiencies in wireless signaling in the NTN for enhancements that include: an initial access when the UE is in idle or inactive mode, HO operations, and RRC redirect (RRC connection release with redirection to NR in the NTN) operations to support SSB enhancement (e.g., SSB extensions) . For example, a UE can operate to initiate an initial access for a NTN satellite while in a RRC idle mode (idle mode) or a RRC inactive mode (inactive mode) , a HO operation in an RRC connect mode, or a RRC redirection in the RRC connect mode.
[0029] In an aspect, the UE can perform a cell search during the initial access on an NTN band based on one of a plurality of (set of) candidate values of SSB periodicities. The candidate values can each correspond to a different specific band ID, respectively, or a region ID, according to a predefined association in a dataset or memory storage of the UE. For example, a band X can mapped to a predefined SSB periodicity M in the dataset, where X or M can be an integer greater than zero. An SSB periodicity M in this disclosure can be, for example, 20ms, 40ms, 80ms, 120ms, 160ms, 360ms or other periodicity greater than or less than 360ms herein. Additionally, or alternatively, other various aspects related to the UE for an initial access the NTN are further described herein with reference to figures.
[0030] Additionally, or alternatively, for a HO operation in the NTN, the UE can receive and process a HO command from the NTN or NTN satellite while in an RRC connected mode. The HO command can include a SSB periodicity of a target cell for the HO. The UE can then perform a synchronization with the target cell based on the SSB periodicity from the HO command.
[0031] Additionally, or alternatively, while in a RRC connected mode (connect mode) for a HO operation in the NTN, the UE can perform a HO from a serving cell to a target cell, based on a predefined mapping in a data set of a plurality of NTN band IDs / NTN region IDs that corresponding to a plurality of SSB periodicities, respectively. Additionally, or alternatively, other various aspects related to the UE for HO operation in the NTN from a serving cell to a target cell are further described herein with reference to the figures.
[0032] Additionally, or alternatively, while in a connect mode for a RRC connection release with redirection to NR operation (RRC redirection) in the NTN, the UE can perform the RRC redirection from a current serving carrier frequency to a target carrier frequency by obtaining a RRC redirection command comprising a SSB periodicity of a target carrier frequency from the NTN satellite. The UE can then perform a synchronization with the target carrier frequency based on the SSB periodicity of the RRC redirection command.
[0033] Additionally, or alternatively, while in a connect mode for a RRC connection release with redirection to NR operation (RRC redirection) in the NTN, the UE can perform the RRC redirection from a current serving carrier frequency to a target carrier frequency based on a predefined mapping in a dataset of NTN band IDs / NTN region IDs corresponding to each of the plurality of candidate values of the SSB periodicities, respectively. Additionally, or alternatively, other various aspects related to the UE for RRC redirection in the NTN from a current serving carrier frequency to a target carrier frequency are further described herein with reference to the figures.
[0034] FIG. 1 illustrates an example NTN network including a NTN satellite 160 that can include at least one or more components of a base station (e.g., an on-board gNB or other network device / component) . The NTN satellite 160 can operate to provide coverage to one or more NTN satellite cells such as NTN cells 102, 104 or others. Each NTN cell 102 and 104 can include NTN beams with particular beam footprints 106 and 108, respectively. Each beam footprint 106, 108 can include one or more NTN bands of frequency carriers.
[0035] A UE 110 can initially acquire access to an NTN cell when in idle mode (e.g., RRC_IDLE mode) after powering up and performing an initial access. The UE 110 can be in one or more of: RRC states; RRC_IDLE (idle mode or state) , RRC_INACTIVE, and RRC_CONNECTED as defined for a 5G NR UE. After power up, the UE 110 can be in idle mode and in order to perform data transfer or to make / receive voice calls, the UE 110 establishes connection with the network which is done by performing initial access operations (e.g., via RRC connection establishment procedure) . Once RRC connection is established, the UE is in RRC_CONNECTED mode.
[0036] Whenever UE 110 needs to perform some activity, it transitions to the connected mode that includes some RRC signaling with the network. 5G NR has defines a RRC_INACTIVE mode or state to reduce network signaling load as well as to reduce latency involved in transitioning to RRC_CONNECTED state. In brief, the UE 110 is in a when an RRC connection (connection mode) has been established or in RRC_INACTIVE (if the UE is connected to 5GC) when RRC connection is suspended. If this is not the case, i.e. no RRC connection is established, the UE is in RRC_IDLE state.
[0037] Initial access can refer to the RACH process between the UE 110 and base station or NTN satellite 160 (network) for the UE to acquire uplink synchronization and specified identification for radio access communication. For initial access operations, the UE 110 can randomly select and transmits a physical random access preamble, for example, and to avoid collision with any other UE connected to the network, a PRACH collision can occur called “contention” , which refers to the RACH process for initial access that allows this type of contention called a contention based RACH process (CBRA) . On the other hand, when the network allocates a physical random access preamble for use to the UE 110 to preemptively avoid such collision, the RACH process for initial access is called a contention free RACH process. When CFRA is utilized, the UE can be configured with a set of candidate beams via an SSB.
[0038] An SMTC defines an SMTC window or occasion, as well as the SSB periodicity that can be used to restrict or enable the UE measurements on certain resources. Within the SMTC window / SMTC occasion including the configured SSB, the UE 110 can conduct the Radio Link Monitoring (RLM) / radio resource measurement (RRM) according to the measurement periodicity and the timing of the SSBs (e.g., SSB periodicity) . The SSBs and SMTC windows (occasions) can be configured differently for each cell, as well as each carrier frequency or band in order to avoid unnecessary measurements and reduce the power consumption of the UE 110. When the UE has been notified of the parameters of an SMTC window by the network, the UE 110 can detect and measure the SSBs within that SMTC window (or occasion) and report the measurement results back to the network.
[0039] When the UE 110 is configured to perform a HO, the UE 110 is mobilized from the serving cell (e.g., NTN cell 102) to a target cell (e.g., NTN cell 104) while operating in a connected mode; in this manner, the HO can enable the UE 110 to stay connected to the network when moving. HO can be triggered, for example, by changing radio conditions (e.g., weakening connection to the source or serving cell 102, network load conditions, or other condition) . Signaling within the network can then ensure that context information is suitably transferred from the serving cell 102 to the target cell 104 for wireless connectivity.
[0040] An RRC redirection or a RRC connection release with redirection to NR can be utilized by the network for the UE 110 to be redirected from a serving carrier frequency to a target carrier frequency, while in an RRC connected mode, which may happen when a source cell or target carrier frequency is powering down for power savings or an interface is not available for handover. After redirection, the UE 110 may be put into an idle mode (state) .
[0041] As reference above, for HO or a conditional HO, if the UE 110 is not provided an SMTC configuration or measurement object on this frequency, a Trs of 5 ms is applied assuming a legacy SSB periodicity of 5ms. However, there is no requirement for HO if the SSB periodicity is not 5ms. For RRC connection release with redirection, if the UE is not provided with the SMTC configuration or measurement object for the frequency that is also configured for the RRC connection release with redirection, then the requirement for this procedure applies with Trs = 20ms if the SSB periodicity is not larger than 20ms; otherwise, there is no requirement if the SSB periodicity for transmission is larger than 20ms. In this context, HO assumes a 5ms SSB periodicity of a target cell and the RRC redirection assumes a 20ms SSB periodicity.
[0042] Various aspects can be configured for initial access. In an aspect, a band specific SSB periodicity mechanism can be utilized or specified for the UE 110 as illustrated at FIG. 200 illustrating a predefined mapping in a dataset 200 or table stored or communicated to the UE 110. The UE 110 can perform an initial access by performing a cell search by searching cells with a specific SSB periodicity corresponding to a specific band or geographical region. Each NTN band or region of a cell can have a predefined mapping to one or more SSB periodicities. NTN band X or region X can be associated with an SSB periodicity M, in which X is an NTN band ID / band index, or region ID / region index, for example; X and M can be an integer of one or greater. The SSB periodicity M, for example, can be 20ms, 40ms, 80ms, 100ms, 120ms, 160ms, 320ms, or other SSB periodicity value based on a predefined mapping of a dataset 200, as specified or stored in a predefined mapping for the UE 110.
[0043] For example, the UE 110 can perform a cell search during an initial access based on the predefined mapping of dataset 200 according to an NTN band ID of X and the SSB periodicity M. Alternatively, if the UE 110 determines the NTN band ID is Y, the SSB periodicity Y is mapped to correspond to NTN band ID Y and be a different SSB periodicity than M, for example. The network or NTN satellite 160 can operate as well in a similar manner as the UE 110 to follow the predefined mapping of the dataset 200 when transmitting the SSB on each specific band X (or Y) by using the associated periodicity M (or N) , for example. The UE 110 in turn can use the dataset to monitor and receive the SSB at the appropriate timing for cell searching with a SSB periodicity for the corresponding NTN band ID.
[0044] By specifying or identifying the dataset 200 with a predefined mapping of various band IDs or geographical region IDs, the UE 110 can perform blind cell searching during the initial access on the band X / region X by using the associated S block periodicity M to band X / region X. For example, the UE chipset can include this relation between the SSB periodicities and band IDs / region IDs, respectively, hard coded into the UE 110, the UE chipset. Then no matter which country this UE powers on, the UE 110 can perform blind detection of a NTN cell by performing a carrier frequency scan from one band to another band in one or more iterations. For example, if the UE scans band X, then UE knows because the hard coded SSB periodicity is like 20 milliseconds and 160 milliseconds, then the UE 110 can attempt both to perform blind searching in an initial access to this band X. Likewise, the network can also follow the specified predefined mapping in the dataset to transmit the SSB of each specific NTN band by using this associated periodicity.
[0045] Additionally, or alternatively, at FIG. 3 for initial access or cell selection, while in idle mode or inactive mode of an NTN network, the UE 110 can operate to initiate cell searching in an initial access a predefined mapping of a dataset 300 according to a geographical region (e.g., USA, China or other region) or a Region ID (e.g., X, Y or other ID) mapped to a particular SSB periodicity (e.g., A, B or other periodicity) . The region specific SSB periodicity mechanism can be used by the UE 110 as predefined in the dataset 300 from memory or specified in standard from the network. The UE 110 can perform initial access by searching cells with a SSB periodicity associated with a specific region. For example, when in region X or region Y the UE 110 can use the corresponding SSB periodicity to perform cell searching in an initial access. Likewise, the network can transmit each SSB in each specific region by using the associated SSB periodicity accordingly.
[0046] Alternatively, or additionally, the UE 110 can initiate an initial access or cell selection, while in idle mode or inactive mode of an NTN network, with a default SSB periodicity (e.g., 20ms) initially according to a process flow 400 of FIG. 4. For example, at 410, the UE 110 perform a cell search during initial access on an NTN band or region based on one of a set (one or more) candidate values of SSB periodicities using a default candidate value (e.g., 20ms) initially. If it is successful, the process flow 400 ends at 410. In response to the cell search during the initial access failing to identify a cell on the NTN band with the default candidate value of the default SSB periodicity, at 420 the UE 110 can perform the cell search with a higher SSB periodicity candidate value (e.g., 40ms or other periodicity) from among the SSB periodicity candidate values to identify an NTN cell on the NTN band or region. If it is successful, the process flow 400 ends at 420; otherwise, the process flow continues. At 430, the UE 110 can perform one or more increasing iterations of the cell search with another candidate value by increasing the legacy candidate value up to a maximum candidate value of a maximum SSB periodicity. The process flow 400 can repeat until at any one act or step (e.g., 410, 420 or 430) the UE 110 identifies a cell on the NTN network or until satisfying a threshold number of access attempts for the cell search failure (e.g., 2, 3, 4 attempts, or more attempts at a cell search) . After a failed number of attempts, the UE 110 could switch to a different carrier frequency for the cell search and repeat the process flow.
[0047] FIG. 5 illustrates another example of a process flow 500 for an initial access or cell selection, while in idle mode or inactive mode of an NTN network. The process flow 500 can begin at 510 with initiating a cell search with a maximum candidate value of a maximum SSB periodicity (e.g., 360ms or other periodicity) among a plurality of SSB periodicity candidate values of SSB periodicities. The process flow 500 continues at 520 with performing the cell search with a lower SSB periodicity candidate value than the maximum SSB periodicity to acquire the NTN band. This can be performed in response to the cell search failing to acquire the NTN band with the maximum candidate value of the maximum SSB periodicity. If it is successful, the process flow 500 ends at 510. If not successful, the process flow 500 continues. At 530, the UE 110 can perform one or more increasing iterations of the cell search with another candidate value by decreasing the maximum candidate value of the maximum SSB periodicity down to a legacy SSB periodicity candidate value (e.g., 20ms) until identifying a cell on the NTN band, or reaching a threshold number of access attempts for a cell search failure. After a failed number of attempts, the UE 110 could switch to a different carrier frequency for the cell search and repeat the process flow.
[0048] FIG. 6 illustrates another example of a process flow 600 for an initial access or cell selection, while in idle mode or inactive mode of an NTN network. The UE 110 can operate to prioritize access to a legacy carrier / band first, and then after reading the system information, the UE 110 can switch or handover to a different or updated NTN band. The process flow 600 can begin at 610 with performing cell search or cell selection in initial access with a legacy NTN band comprising a legacy SSB periodicity / At 620, in response to identifying a NTN cell on the legacy NTN band with a legacy SSB periodicity, acquiring a system information (SI) from the NTN cell. At 630, the UE 110 can obtain or store an updated SSB periodicity from the SI. At 640, the UE can acquire access to an updated NTN band based on the updated SSB periodicity from the SI. The network can then switch or handover the UE to the other NTN with the updated information or SSB periodicity. The network or NTN satellite 160 can anticipate the UE 110 to camp on a cell of the legacy NTN initially and then afterwards operate to switch such UEs to another new NTN band as needed.
[0049] FIG. 7 illustrates another example of a process flow 700 for an initial access or cell selection, while in idle mode or inactive mode of an NTN network. The UE 110 can operate to use previously stored information to determine or decide the SSB periodicity for another initial access after powering up or rebooting again, especially when in a different locality, or geographic region. Initially, the UE 110 could have implemented aspects described above in particular such with data set 200 of FIG. 2, dataset 300 of FIG. 3, or any one or more of process flows 400 thru 600 of FIG 4 thru 6, for example, and stored or recorded system information or other information related to an NTN band before powering down or off. The UE 110 can then use the information recorded to perform an initial access in idle or inactive mode for a new initial access after powering on again, especially in localities not previously provided or stored in the a dataset, for example, to utilize or assume the SSB periodicity for specific NTN bands for cell searching. In particular, the UE 110 could be roaming and use the stored information in an initial access to a current network where the SSB periodicity may be different.
[0050] The process flow 700 can initiate at 710 with processing a system information (SI) from the NTN cell in response to acquiring a NTN cell on the NTN band with the one of the plurality of candidate values of the SSB periodicities. At 720, the UE 110 can record, in memory, information of the NTN band that is associated with the plurality of candidate values of the SSB periodicities. At 730, the UE 110 can further perform the cell search during the initial access based on the information of the NTN band in the memory in response to a rebooting or repowering of the processing circuitry of the UE.
[0051] Additionally, or alternatively, various aspects can be configured for HO in an NTN network when in an RRC connect mode, in which the UE 110 already has a connection with a serving cell such as NTN cell .
[0052] FIG. 8 illustrates an example of a NTN network 800 for HO operation. The UE 110 can be provided, receive and process an HO command 802 from the NTN satellite 160. The NTN satellite 160 provides a trigger or request to initiate HO in the UE 110 from a current serving cell 102 to a target cell 104, for example. The HO command 802 can explicitly indicate a target cell with the associated SSB periodicity directly to avoid ambiguity for HO by the UE 110 and speed up searching for the target cell 104. Once the UE receives the HO command 802, the UE 110 can utilize the SSB periodicity of the HO command 802 to perform cell searching and perform a synchronization with the target cell 104 based on the SSB periodicity from the HO command 802 for connection with the target cell 104 of the NTN satellite 160.
[0053] FIG. 9 illustrates an example process flow 900 for a HO operation based on an information exchange. With process flow 900, the UE 110 can perform an information exchange with a serving cell (e.g., serving cell 102) of NTN satellite 160. The UE 110 can receive and process RRC signaling with preconfigured information upon accessing the serving cell 102. The RRC signaling can be provided to the UE 110 during an RRC (re) configuration operation, for example, in an associated information exchange between the UE 110 and the serving cell of the NTN network at access in RRC connect mode. During the information exchange, the UE 110 receives a band specific SSB periodicity for the UE for future mobility with a HO to a target cell 104 of FIG. 1 or 8, for example. In an example, the NTN serving cell 102 of the NTN satellite 160 can preconfigure the band specific SSB periodicity by providing the UE 110 an SSB periodicity M or A (e.g., 5ms, 20ms, 40ms, 80ms, 120ms, 160ms, 360ms or other periodicity value) associated with a band index or band ID (e.g., band X) , and for others bands not configured by network, legacy 5ms can be assumed.
[0054] The process flow 900 initiates at 910 with performing an information exchange with the NTN serving cell 102, for example. This can be performed upon an RRC connect with the serving cell 102 during an RRC (re) configuration operation, for example. The NTN satellite 160 or network via an RRC signaling layer can provide the SSB periodicity to the UE 110. At 920, the process flow 900 continues with the UE 110 receiving one or more SSB periodicities from the NTN serving cell 102 that correspond to, or is associated with an NTN band, band ID or band index, respectively, for an HO to an NTN target cell 104, for example. After receiving an HO command from the network, the UE 110 can identify the target cell 104 based on the SSB periodicity with the associated band or band ID for HO to the target cell. At 930, the UE 110 can perform operations at 932, 934, or both at different times. At 932, the UE 110 performs the HO to the target cell 104 by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities. Additionally, or alternatively, at 934, the UE 110 can default to use a legacy SSB periodicity of 5 ms for HO when not provided an associated SSB periodicity of the target cell or NTN band by the serving cell of the NTN satellite with the one or more SSB periodicities and the one or more band IDs. In this instance, the UE 110 may have received various candidate values of SSB periodicities with or without associated band ID information in the information exchange and attempting HO to a different target cell than in the provided information, for example.
[0055] FIG. 10 illustrates another example process flow for HO in an NTN network. The process flow 1000 is similar to the process flow with dataset 200 of FIG. 2 or data set 300 of FIG. 3, but at process flow 1000 the UE 110 is in RRC connect mode and performs HO with the predefined dataset 200 or 300 provided to it by RRC signaling, a higher layer signaling or in a storage / memory of the UE 110, for example.
[0056] At 1010, the process flow 1000 initiates with the UE 110 performing a HO from a serving cell 102 to a target cell 104, based on a predefined mapping in a dataset 200 FIG. 2 or dataset 300 of FIG. 3 with a plurality of NTN band IDs / NTN region IDs each mapped to a band ID or region ID, respectively. Upon receiving the HO command, the UE 110 can select a band ID or region ID from among datasets 200 or 300 and utilized the SSB periodicity mapped to it accordingly, based on its location or other conditional parameters. Alternatively, or additionally, at 920, the UE 110 can perform the HO from a serving cell 102 to a target cell 104, for example, based on a legacy SSB periodicity (e.g., 5ms) for HO. After receiving the HO command from the network or NTN serving cell 102, the UE 110 can identify the target cell 104 based on a selected SSB periodicity with the associated band or band ID for HO to the target cell. The UE 110 can then perform the HO to the target cell 104 by using the one or more SSB periodicities and the one or more band IDs / region IDs corresponding to the one or more SSB periodicities. Additionally, or alternatively, at 1020, the UE 110 can default to use a legacy SSB periodicity of 5ms for HO when not provided an associated SSB periodicity of the target cell with an NTN band / region ID by the serving cell 102 of the NTN satellite with the one or more SSB periodicities mapped to the one or more band / region IDs. In this instance, the UE 110 may have received various candidate values of SSB periodicities with or without associated band ID information in the information exchange and attempting HO to a different target cell than in the provided information, for example.
[0057] FIG. 11 illustrates an example process flow 1100 for HO in an NTN cell. Similar to process flow 400 of FIG. 4, but for HO operation, at 1110 the UE 110 can perform a HO from a serving cell 102 to a target cell 104, based on a legacy SSB periodicity (e.g., 5ms for legacy HO) initially. At 1120, the UE 110 can increase the legacy SSB periodicity incrementally to a higher SSB periodicity candidate value to identify the target cell on the NTN when the initial default value results in a cell search failure. At 1130, the UE can continue with additional iterations of HO attempts in one or more handover synchronization iterations up to a maximum SSB periodicity (e.g., 120ms, 360ms, or other periodicity value higher than 20ms) in response to a synchronization to the target cell failing previously by configuring various increments to the SSB periodicity value.
[0058] FIG. 11 illustrates an example process flow 1100 for HO in an NTN cell. Similar to process flow 400 of FIG. 4, but for HO operation, at 1110 the UE 110 can perform a HO from a serving cell 102 to a target cell 104, based on a legacy SSB periodicity (e.g., 5ms for legacy HO) initially. At 1120, the UE 110 can increase the legacy SSB periodicity incrementally to a higher SSB periodicity candidate value to identify the target cell on the NTN when the initial default value results in a cell search failure. At 1130, the UE can continue with additional iterations of HO attempts in one or more handover synchronization iterations up to a maximum SSB periodicity (e.g., 120ms, 360ms, or other periodicity value higher than 5ms, the legacy value) in response to a synchronization to the target cell failing previously by configuring various increments in the value to a different SSB periodicity value. In this manner, the UE 110 can use the legacy 5ms SSB periodicity as the starting point for HO if no explicit SSB periodicity is provided; if the UE cannot synchronize to the target cell, and then the UE can increase the assumption of SSB periodicity to N (N > 5ms) for a new round or iteration of synchronization, until the N reaches the max SSB periodicity.
[0059] FIG. 12 illustrates an example process flow 1200 for HO in an NTN cell. Similar to process flow 500 of FIG. 4, but for HO operation, at 1210 the UE 110 can perform a HO from a serving cell 102 to a target cell 104, based on a maximum candidate value of a maximum SSB periodicity (e.g., 160ms, 360ms or other periodicity value) initially. At 1220, the UE 110 can decrease the maximum SSB periodicity by decrementing to a lower SSB periodicity candidate value in an attempt to identify the target cell 104 on the NTN when the initial default maximum candidate value results in a cell search failure. At 1230, the UE 110 can continue with further iterations of HO attempts in one or more handover synchronization iterations down to a legacy SSB periodicity (e.g., 5ms) in response to a synchronization to the target cell failing previously at 1210 and 1220 by configuring decrements in value to a different SSB periodicity value at each iteration. In this manner, the UE 110 can use candidate value for synchronization with the SSB periodicity as the value for the starting point for HO if no explicit SSB periodicity is provided. If the UE 110 cannot synchronize to target cell 104, and then the UE can decrease the assumption of SSB periodicity to N (N<Tms) for a new round of synchronization, until the N reaches the 5ms SSB periodicity, where the Tms is time value or candidate value in ms for synchronization with the SSB periodicity.
[0060] FIGs. 13 thru 16 are similar to FIGs. 8 thru 12, respectively, and illustrate similar operations for an RRC redirection to a target carrier of the NTN network.
[0061] FIG. 13 illustrates an example of a NTN network 1300 for RRC redirection operation. The UE 110 can be provided, receive and process an RRC redirection command 1302 from the NTN satellite 160. The NTN satellite 160 provides a trigger or request to initiate RRC redirection in the UE 110 from a current serving cell 102 to a target carrier frequency, for example. The RRC redirection command 1302 can explicitly indicate a target carrier frequency with the associated SSB periodicity directly to avoid ambiguity for RRC redirection by the UE 110 and speed up searching for a target carrier frequency. Once the UE receives the RRC redirection command 1302, the UE 110 can utilize the SSB periodicity of the RRC redirection command 1202 to perform synchronization the target carrier frequency based on the SSB periodicity from the RRC redirection command 1302 for connection with the target carrier frequency of the NTN satellite 160.
[0062] FIG. 14 illustrates an example process flow 1400 for RRC redirection operation based on an information exchange. With process flow 1400, the UE 110 can perform an information exchange with a serving cell (e.g., serving cell 102) of NTN satellite 160. The UE 110 can receive and process RRC signaling with preconfigured information upon accessing the serving cell 102. The RRC signaling can be provided to the UE 110 during an RRC (re) configuration operation, for example, in an associated information exchange between the UE 110 and the serving cell of the NTN network at access in RRC connect mode. During the information exchange, the UE 110 can receive a band specific SSB periodicity for RRC redirection. In an example, the NTN serving cell 102 of the NTN satellite 160 can preconfigure the band specific SSB periodicity by providing the UE 110 an SSB periodicity M or A (e.g., 20ms, 40ms, 80ms, 120ms, 160ms, 360ms or other periodicity value) associated with a band index or band ID (e.g., band X) , and for others bands not configured by network, a legacy of 20ms can be assumed.
[0063] The process flow 1400 initiates at 1410 with performing an information exchange with the NTN satellite to receive one or more SSB periodicities and one or more band IDs or one or more target frequency IDs corresponding to the one or more SSB periodicities, respectively, for a RRC redirection to a select target carrier frequency. At 1420, the process flow 1400 continues with the UE receiving one or more SSB periodicities corresponding to one or more target carrier frequencies, respectively. At 1430, the process flow 1400 continues to at 1430 by performing at 1432 the RRC redirection to the target carrier frequency by using the one or more SSB periodicities, or at 1434 using a legacy SSB periodicity of 20ms when the target carrier frequency is not provided with the one or more SSB periodicities, which can be associated with or include a target carrier frequency or target carrier ID, respectively. The SSB periodicities can also associated with a band Id / region ID in which the target carrier is on a certain band.
[0064] FIG. 15 illustrates another example process flow for RRC redirection in an NTN network. At 1510, the process flow 1500 initiates with performing a RRC redirection to a target carrier frequency based on a predefined mapping in a dataset of NTN band IDs / NTN region IDs corresponding to each of the plurality of candidate values of the SSB periodicities, respectively. If the band and SSB is not in the dataset, the UE can default to a legacy value of 20ms SSB periodicity. Alternatively, or additionally, at 1520 the RRC redirection can be based on a legacy SSB periodicity (e.g., 20ms) and the UE can incrementally increase the legacy SSB periodicity incrementally in one or more RRC redirection synchronization iterations up to a maximum SSB periodicity in response to a previous synchronization to the target carrier frequency failing.
[0065] FIG. 16 illustrates an example process flow 1600 for RRC redirection in an NTN cell. At 1610 the UE 110 can perform RRC redirection to a target carrier frequency, based on a maximum candidate value of a maximum SSB periodicity (e.g., 160ms, 360ms or other periodicity value) initially. At 1620, the UE 110 can decrease the maximum SSB periodicity by decrementing to a lower SSB periodicity candidate value in an attempt to identify the target carrier frequency on the NTN when the initial default maximum candidate value results in a carrier frequency search failure / carrier frequency acquire failure. At 1630, the UE 110 can continue with further iterations of RRC redirection attempts in one or more RRC redirection synchronization iterations down to a legacy SSB periodicity (e.g., 20ms) in response to a synchronization to the target carrier failing previously by configuring decrements in value to a different SSB periodicity value at each iteration. In this manner, the UE 110 can use the SSB periodicity as the starting point for RRC redirection if no explicit SSB periodicity is provided. If the UE 110 cannot synchronize to a target carrier frequency, then the UE can decrease the assumption of SSB periodicity to N (N<Tms) for a new iteration round of synchronization, until the N reaches the 20ms SSB periodicity.
[0066] FIG. 17 is an example network 1700 according to one or more implementations described herein. Example network 1700 can include UEs 110-1, 110-2, etc. (referred to collectively as “UEs 110” and individually as “UE 110” ) , a radio access network (RAN) 1722, a core network (CN) 1730, application servers 1740, and external networks 1750 and satellites 160-1, 160-2, etc. (referred to collectively as “satellites 160” and individually as “satellite 160” ) . As shown, network 1700 may include a non-terrestrial network (NTN) comprising one or more satellites 160 (e.g., an NTN satellite of a global navigation satellite system (GNSS) ) in communication with UEs 110 and co-located with a RAN 1722 or configured as a distributed network station.
[0067] UEs 110 can communicate and establish a connection with (be communicatively coupled to) RAN 1722, which can involve one or more wireless channels 1714-1 and 1714-2, each of which can comprise a physical communications interface / layer. In some implementations, a UE can be configured with dual connectivity (DC) as a multi-radio access technology (multi-RAT) or multi-radio dual connectivity (MR-DC) , where a multiple receive and transmit (Rx / Tx) capable UE can use resources provided by different network nodes or base stations 1722 (e.g., 1722-1 and 1722-2) that can be connected via non-ideal backhaul (e.g., where one network node provides NR access and the other network node provides either E-UTRA for LTE or NR access for 5G) . In such a scenario, one network node can operate as a master node (MN) and the other as the secondary node (SN) . The MN and SN can be connected via a network interface, and at least the MN can be connected to the CN 1730. Additionally, at least one of the MN or the SN can be operated with shared spectrum channel access, and functions specified for UE 110 can be used for an integrated access and backhaul mobile termination (IAB-MT) . Similar for UE 110, the IAB-MT can access the network using either one network node or using two different nodes with enhanced dual connectivity (EN-DC) architectures, new radio dual connectivity (NR-DC) architectures, or other direct connectivity such as an SL communication channel as an SL interface 1712.
[0068] In some implementations, a base station (as described herein) can be an example of network node 1722. As shown, UE 110 can additionally, or alternatively, connect to access point (AP) 1716 via connection interface 1718, which can include an air interface enabling UE 110 to communicatively couple with AP 1716. AP 1716 can comprise a wireless local area network (WLAN) , WLAN node, WLAN termination point, etc. The connection 1718 can comprise a local wireless connection, such as a connection consistent with any IEEE 702.11 protocol, and AP 1716 can comprise a wireless fidelity router or other AP. AP 1716 could be also connected to another network (e.g., the Internet) without connecting to RAN 1722 or CN 1730.
[0069] RAN 1722 can also include one or more RAN nodes 1722-1 and 1722-2 (referred to collectively as RAN nodes 1722, and individually as RAN node 1722) that enable channels 1714-1 and 1714-2 to be established between UEs 110 and RAN 1722. RAN nodes 1722 can include network access points configured to provide radio baseband functions for data or voice connectivity between users and the network based on one or more of the communication technologies described herein (e.g., 2G, 3G, 4G, 5G, WiFi, etc. ) . As examples therefore, a RAN node can be an E-UTRAN Node B (e.g., an enhanced Node B, eNodeB, eNB, 4G base station, etc. ) , a next generation base station (e.g., a 5G base station, NR base station, next generation eNBs (gNB) , etc. ) . RAN nodes 1722 can include a roadside unit (RSU) , a transmission reception point (TRxP or TRP) , and one or more other types of ground stations (e.g., terrestrial access points) . In some scenarios, RAN node 1722 can be a dedicated physical device, such as a macrocell base station, or a low power (LP) base station for providing femtocells, picocells or other like having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells. As described below, in some implementations, satellites 160 can operate as bases stations (e.g., RAN nodes 1722) with respect to UEs 110. As such, references herein to a base station, RAN node 1722, etc., can involve implementations where the base station, RAN node 1722, etc., is a terrestrial network node and also to implementation where the base station, RAN node 1722, etc., is a non-terrestrial network node.
[0070] Some or all of RAN nodes 1722 can be implemented as one or more software entities running on server computers as part of a virtual network, which can be referred to as a centralized RAN (CRAN) or a virtual baseband unit pool (vBBUP) . In these implementations, the CRAN or vBBUP can implement a RAN function split, such as a packet data convergence protocol (PDCP) split wherein radio resource control (RRC) and PDCP layers can be operated by the CRAN / vBBUP and other Layer 2 (L2) protocol entities can be operated by individual RAN nodes 1722; a media access control (MAC) / physical (PHY) layer split wherein RRC, PDCP, radio link control (RLC) , and MAC layers can be operated by the CRAN / vBBUP and the PHY layer can be operated by individual RAN nodes 1722; or a “lower PHY” split wherein RRC, PDCP, RLC, MAC layers and upper portions of the PHY layer can be operated by the CRAN / vBBUP and lower portions of the PHY layer can be operated by individual RAN nodes 1722. This virtualized framework can allow freed-up processor cores of RAN nodes 1722 to perform or execute other virtualized applications, for example.
[0071] In some implementations, an individual RAN node 1722 can represent individual gNB-distributed units (DUs) connected to a gNB-control unit (CU) via individual F1 interfaces. In such implementations, the gNB-DUs can include one or more remote radio heads or radio frequency (RF) front end modules (RFEMs) , and the gNB-CU can be operated by a server (not shown) located in RAN 1722 or by a server pool (e.g., a group of servers configured to share resources) in a similar manner as the CRAN / vBBUP. Additionally, or alternatively, one or more of RAN nodes 1722 can be next generation eNBs (i.e., gNBs) that can provide evolved universal terrestrial radio access (E-UTRA) user plane and control plane protocol terminations toward UEs 110, and that can be connected to a 5G core network (5GC) 1730 via a Next Generation (NG) interface 1724.
[0072] Any of the RAN nodes 1722 can terminate an air interface protocol and can be the first point of contact for UEs 110. In some implementations, any of the RAN nodes 1722 can fulfill various logical functions for the RAN 1722 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. UEs 110 can be configured to communicate using orthogonal frequency-division multiplexing (OFDM) communication signals with each other or with any of the RAN nodes 1722 over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an OFDMA communication technique (e.g., for downlink communications) or a single carrier frequency-division multiple access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink (SL) communications) , although the scope of such implementations cannot be limited in this regard. The OFDM signals can comprise a plurality of orthogonal subcarriers.
[0073] A physical downlink shared channel (PDSCH) can carry user data and higher layer signaling to UEs 110. The physical downlink control channel (PDCCH) can carry information about the transport format and resource allocations related to the PDSCH channel, among other things. The PDCCH can also inform UEs 110 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information related to the uplink shared channel. Typically, downlink scheduling (e.g., assigning control and shared channel resource blocks to UE 110-2 within a cell) can be performed at any of the RAN nodes 1722 based on channel quality information fed back from any of UEs 110. The downlink resource assignment information can be sent on the PDCCH used for (e.g., assigned to) each of UEs 110.
[0074] The PDCCH uses control channel elements (CCEs) to convey the control information, wherein a number of CCEs (e.g., 6 or other number) can consists of a resource element groups (REGs) , where a REG is defined as a physical resource block (PRB) in an OFDM symbol. Before being mapped to resource elements, the PDCCH complex-valued symbols can first be organized into quadruplets, which can then be permuted using a sub-block interleaver for rate matching, for example. Each PDCCH can be transmitted using one or more of these CCEs, where each CCE can correspond to nine sets of four physical resource elements known as REGs. Four quadrature phase shift keying (QPSK) symbols can be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the DCI and the channel condition. There can be four or more different PDCCH formats with different numbers of CCEs (e.g., aggregation level, L=1, 2, 4, 8, or 16) .
[0075] The RAN nodes 1722 may be configured to communicate with one another via interface 1723. In implementations where the system is an LTE system, interface 1723 may be an X2 interface. In LTE networks, X2 and S1 interface are defined as the interfaces between RAN nodes and between RAN and Core Network. 5G may operate in two modes as non-standalone and standalone mode. For non-standalone operation the specification defines the extension for S1 and X2 interfaces as for standalone operation as X2 / Xn for the interface between RAN nodes 1722 and S1 / NG for the interface 1724 between RAN 1722 and CN 1730. The interface 1724 may be defined between two or more RAN nodes 1722 (e.g., two or more eNBs / gNBs or a combination thereof) that connect to evolved packet core (EPC) , the CN 1730, or between eNBs connecting to an EPC. In some implementations, the X2 / Xn interface may include an X2 / Xn user plane interface (X2-U / Xn-U) and an X2 control plane interface (X2-C / Xn-C) . The X2-U / Xn-U may provide flow control mechanisms for user data packets transferred over the X2 / Xn interface and may be used to communicate information about the delivery of user data between eNBs or gNBs. For example, the X2-U / Xn-U may provide specific sequence number information for user data transferred from a master eNB (MeNB) to a secondary eNB (SeNB) ; information about successful in sequence delivery of PDCP packet data units (PDUs) to a UE 110 from an SeNB for user data; information of PDCP PDUs that were not delivered to a UE 110; information about a current minimum desired buffer size at the SeNB for transmitting to the UE user data; and the like. The X2-C / Xn-C may provide intra-LTE access mobility functionality (e.g., including context transfers from source to target eNBs, user plane transport control, etc. ) , load management functionality, and inter-cell interference coordination functionality.
[0076] Alternatively, or additionally, RAN 1722 can be also connected (e.g., communicatively coupled) to CN 1730 via a Next Generation (NG) interface as interface 1724. The NG interface 1724 can be split into two parts, a Next Generation (NG) user plane (NG-U) interface 1726, which carries traffic data between the RAN nodes 1722 and a User Plane Function (UPF) , and the S1 control plane (NG-C) interface 1728, which is a signaling interface between the RAN nodes 1722 and Access and Mobility Management Functions (AMFs) .
[0077] CN 1730 can comprise a plurality of network elements 1732, which are configured to offer various data and telecommunications services to customers / subscribers (e.g., users of UEs 110) who are connected to the CN 1730 via the RAN 1722. In some implementations, CN 1730 can include an evolved packet core (EPC) , a 5G CN, and / or one or more additional or alternative types of CNs. The components of the CN 1730 can be implemented in one physical node or separate physical nodes including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) .
[0078] As shown, CN 1730, application servers 1740, and external networks 1750 can be connected to one another via interfaces 1734, 1736, and 1738, which can include IP network interfaces. Application servers 1740 can include one or more server devices or network elements (e.g., virtual network functions (VNFs) offering applications that use IP bearer resources with CN 1730 (e.g., universal mobile telecommunications system packet services (UMTS PS) domain, LTE PS data services, etc. ) . Application servers 1740 can also, or alternatively, be configured to support one or more communication services (e.g., voice over IP (VoIP sessions, push-to-talk (PTT) sessions, group communication sessions, social networking services, etc. ) for UEs 110 via the CN 1730. Similarly, external networks 1750 can include one or more of a variety of networks, including the Internet, thereby providing the mobile communication network and UEs 110 of the network access to a variety of additional services, information, interconnectivity, and other network features.
[0079] As shown, example network 1700 may include an NTN that may comprise one or more satellites 160-1 and 160-2 (collectively, “satellites 160” ) . Satellites 160 may be in communication with UEs 110 via service link or wireless interface 1762 and / or RAN 1722 via feeder links or wireless interfaces 1764 (depicted individually as 1764-1 and 1764) . In some implementations, satellite 160 may operate as a passive or transparent network relay node regarding communications between UE 110 and the terrestrial network (e.g., RAN 1722) . In some implementations, satellite 160 may operate as an active or regenerative network node such that satellite 160 may operate as a base station to UEs 110 (e.g., as a gNB of RAN 1722) regarding communications between UE 110 and RAN 1722. In some implementations, satellites 160 may communicate with one another via a direct wireless interface 1766 or an indirect wireless interface (e.g., via RAN 1722 using interfaces 1764-1 and 1764-2) . Additionally, or alternatively, satellite 160 may include a GEO satellite, LEO satellite, or another type of satellite. Satellite 160 may also, or alternatively pertain to one or more satellite systems or architectures, such as a global navigation satellite system (GNSS) , global positioning system (GPS) , global navigation satellite system (GLONASS) , BeiDou navigation satellite system (BDS) , etc. In some implementations, satellites 160 may operate as bases stations (e.g., RAN nodes 1722) with respect to UEs 110. As such, references herein to a base station, RAN node 1722, etc., may involve implementations where the base station, RAN node 1722, etc., is a terrestrial network node and implementation, where the base station, RAN node 1722, etc., is a non-terrestrial network node (e.g., satellite 160) .
[0080] In an aspect, the UE 110, baseband process of the UE 110 or processing circuitry thereof can operate to initiate an initial access for a NTN satellite 160, and perform a cell search during the initial access on an NTN band based on one of a plurality of candidate values of SSB periodicities. The plurality of candidate values can each correspond to a different specific band ID, respectively, or a region ID, according to a predefined mapping association in a dataset. The UE 110 can further initiate the cell search with a default candidate value of a default SSB periodicity, and in response to the cell search during the initial access failing to identify a cell on the NTN band with the default candidate value of the default SSB periodicity, perform the cell search with a higher SSB periodicity candidate value to identify a cell on the NTN band. The UE 110 can initiate the cell search with a legacy candidate value of a legacy SSB periodicity comprising 20ms. In response to a cell search failure of the cell search, the UE 110 can increase the legacy candidate value of the SSB periodicity to a higher candidate value from among a plurality of SSB periodicity candidate values, and further perform one or more increasing iterations of the cell search with another candidate value by increasing the legacy candidate value up to a maximum candidate value of a maximum SSB periodicity until identifying a cell on the NTN band or until satisfying a threshold number of access attempts for the cell search failure. The UE 110 can initiate the cell search with a maximum candidate value of a maximum SSB periodicity among a plurality of SSB periodicity candidate values. In response to the cell search failing to acquire the NTN band with the maximum candidate value of the maximum SSB periodicity, the UE 110 can further perform the cell search with a lower SSB periodicity candidate value to acquire the NTN band, and perform one or more increasing iterations of the cell search with another candidate value by decreasing the maximum candidate value of the maximum SSB periodicity down to a legacy SSB periodicity candidate value until identifying a cell on the NTN band, or reaching a threshold number of access attempts for a cell search failure. The UE can be in an idle mode or an inactive mode when performing the cell search and the NTN band can be a legacy NTN band comprising a legacy SSB periodicity, and, in response to identifying a NTN cell on the legacy NTN band with the legacy SSB periodicity, the UE can acquire a system information (SI) from the NTN cell; obtain an updated SSB periodicity from the SI; and acquire access to an updated NTN band based on the updated SSB periodicity from the SI.
[0081] Alternatively, or additionally, in response to acquiring a NTN cell on the NTN band with the one of the plurality of candidate values of the SSB periodicities, the UE 110 can process a system information (SI) from the NTN cell; record, in the memory, information of the NTN band that is associated with the plurality of candidate values of the SSB periodicities; and in response to a rebooting or repowering of the processing circuitry of the UE, perform the cell search during the initial access based on the information of the NTN band in the memory (e.g., memory 1530 of FIG. 18 or other memory in a baseband processor of the UE.
[0082] Alternatively, or additionally, the UE 110 can process a handover (HO) command while in a radio resource control (RRC) connected mode, the HO command comprising a SSB periodicity of a target cell from a serving cell of the NTN satellite. The UE can then perform a synchronization with the target cell based on the SSB periodicity from the HO command.
[0083] Alternatively, or additionally, the UE 110 can perform an information exchange with a serving cell of the NTN satellite to receive one or more SSB periodicities and one or more band IDs corresponding to the one or more SSB periodicities, respectively, for a handover to a target cell. The UE can then perform the handover to the target cell by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities, or use a legacy SSB periodicity of 5 ms when not provided an associated SSB periodicity of the target cell or NTN band by the serving cell of the NTN satellite with the one or more SSB periodicities and the one or more band IDs.
[0084] Alternatively, or additionally, the UE 110 can perform a handover from a serving cell to a target cell, based on a predefined mapping in a dataset of a plurality of NTN band IDs / NTN region IDs corresponding to a plurality of SSB periodicities, respectively. Alternatively, or additionally, the UE 110 can perform the handover from the serving cell to the target cell based on a legacy SSB periodicity and increasing the legacy SSB periodicity incrementally in one or more handover synchronization iterations up to a maximum SSB periodicity in response to a synchronization to the target cell failing.
[0085] Alternatively, or additionally, the UE 110 can perform a handover from a serving cell to a target cell based on a SSB periodicity and decreasing the SSB periodicity incrementally in one or more handover synchronization iterations down to a legacy SSB periodicity of 5 ms in response to a synchronization to the target cell failing.
[0086] Alternatively, or additionally, the UE 110 can process a RRC redirection command comprising a SSB periodicity of a target carrier frequency from the NTN satellite, and further perform a synchronization with the target carrier frequency based on the SSB periodicity of the RRC redirection command.
[0087] Alternatively, or additionally, the UE 110 can perform an information exchange with the NTN satellite to receive one or more SSB periodicities and one or more band IDs corresponding to the one or more SSB periodicities, respectively, for a RRC redirection to a target carrier frequency. The UE 110 can then perform the RRC redirection to the target carrier frequency by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities, or using a legacy SSB periodicity of 20ms when the target carrier frequency is not provided with the one or more SSB periodicities.
[0088] Alternatively, or additionally, the UE 110 can perform a RRC redirection to a target carrier frequency based on a predefined mapping in a dataset of NTN band IDs / NTN region IDs corresponding to each of the plurality of candidate values of the SSB periodicities, respectively, or based on a legacy SSB periodicity and increasing the legacy SSB periodicity incrementally in one or more RRC redirection synchronization iterations up to a maximum SSB periodicity in response to a synchronization to the target carrier frequency failing.
[0089] Alternatively, or additionally, the UE 110 can perform an RRC redirection to a target carrier frequency based on a SSB periodicity and decreasing the SSB periodicity incrementally in one or more RRC redirection synchronization iterations down to a legacy SSB periodicity of 20 ms in response to a synchronization to the target carrier frequency failing.
[0090] One or more network components, devices or systems of network 1700 is configured to process, perform, generate, communicate or cause execution of any one or more combined aspects described herein or in association with any of the FIGs. 1 thru 16 herein.
[0091] Referring to FIG. 18, illustrated is a block diagram of a UE device 110 (e.g., UE 110-1 or 110-2) or other network device / component 1800 (e.g., V-UE / P-UE, IoT, gNB, eNB, base station, NTN satellite 160 or other participating network entity / component) . The device 1800 includes one or more processors 1810 (e.g., one or more baseband processors) comprising processing circuitry and associated interface (s) , transceiver circuitry 1820 (e.g., comprising RF circuitry, which can comprise transmitter circuitry (e.g., associated with one or more transmit chains) and / or receiver circuitry (e.g., associated with one or more receive chains) that can employ common circuit elements, distinct circuit elements, or a combination thereof) , and a memory 1830 (which can comprise any of a variety of storage mediums and can store instructions and / or data associated with one or more of processor (s) 1810 or transceiver circuitry 1820) .
[0092] Memory 1830 (as well as other memory components discussed herein, e.g., memory, data storage, or the like) can comprise one or more machine-readable medium / media including instructions that, when performed by a machine or component herein cause the machine or other device to perform acts of a method, an apparatus or system for communication using multiple communication technologies according to aspects, embodiments and examples described herein. It is to be understood that aspects described herein can be implemented by hardware, software, firmware, or any combination thereof. When implemented in software, functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium (e.g., the memory described herein or other storage device) . Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media or a computer readable storage device can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or other tangible and / or non-transitory medium, that can be used to carry or store desired information or executable instructions. Any connection can be also termed a computer-readable medium.
[0093] Memory 1830 can include executable instructions, and be integrated in, or communicatively coupled to, processor or processing circuitry 1810. The executable instructions of the memory 1830 can cause processing circuitry 1810 to receive / process the instructions to receive / process / determine / generate NW operations associated with beam hopping according to aspects herein.
[0094] The device 1800 is configured to process, perform, generate, communicate or cause execution of any one or more combined aspects described herein or in association with any of the FIGs. 1 thru 17.
[0095] While the methods described within this disclosure are illustrated in and described herein as a series of acts or events, it will be appreciated that the illustrated ordering of such acts or events are not to be interpreted in a limiting sense. For example, some acts can occur in different orders and / or concurrently with other acts or events apart from those illustrated and / or described herein. In addition, not all illustrated acts can be required to implement one or more aspects or embodiments of the description herein. Further, one or more of the acts depicted herein can be carried out in one or more separate acts and / or phases. Reference can be made to the figures described above for ease of description. However, the methods are not limited to any particular embodiment, aspect or example provided within this disclosure and can be applied to any of the systems / devices / components disclosed herein.
[0096] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.
[0097] The present disclosure is described with reference to attached drawing figures, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As utilized herein, terms “component, ” “system, ” “interface, ” and the like are intended to refer to a computer-related entity, hardware, software (e.g., in execution) , and / or firmware. For example, a component can be a processor (e.g., a microprocessor, a controller, or other processing device) , a process running on a processor, a controller, an object, an executable, a program, a storage device, a computer, a tablet PC and / or a user equipment (e.g., mobile phone, etc. ) with a processing device. By way of illustration, an application running on a server and the server can be also a component. One or more components can reside within a process, and a component can be localized on one computer and / or distributed between two or more computers. A set of elements or a set of other components can be described herein, in which the term “set” can be interpreted as “one or more. ”
[0098] Further, these components can execute from various computer readable storage media having various data structures stored thereon such as with a module, for example. The components can communicate via local and / or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and / or across a network, such as, the Internet, a local area network, a wide area network, or similar network with other systems via the signal) .
[0099] As another example, a component can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors. The one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application. As yet another example, a component can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processors therein to execute software and / or firmware that confer (s) , at least in part, the functionality of the electronic components.
[0100] Use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or” . That is, unless specified otherwise, or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Furthermore, to the extent that the terms “including” , “includes” , “having” , “has” , “with” , or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising. ” Additionally, in situations wherein one or more numbered items are discussed (e.g., a “first X” , a “second X” , etc. ) , in general the one or more numbered items can be distinct, or they can be the same, although in some situations the context can indicate that they are distinct or that they are the same.
[0101] As used herein, the term “circuitry” can refer to, be part of, or include an Application Specific Integrated Circuit (ASIC) , an electronic circuit, a processor (shared, dedicated, or group) , or associated memory (shared, dedicated, or group) operably coupled to the circuitry that execute one or more software or firmware programs, a combinational logic circuit, or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry can be implemented in, or functions associated with the circuitry can be implemented by, one or more software or firmware modules. In some embodiments, circuitry can include logic, at least partially operable in hardware.
[0102] As it is employed in the subject specification, the term “processor” can refer to substantially any computing processing unit or device including, but not limited to including, single-core processors; single-processors with software multithread execution capability; multi-core processors; multi-core processors with software multithread execution capability; multi-core processors with hardware multithread technology; parallel platforms; and parallel platforms with distributed shared memory. Additionally, a processor can refer to an integrated circuit, an application specific integrated circuit, a digital signal processor, a field programmable gate array, a programmable logic controller, a complex programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions and / or processes described herein. Processors can exploit nano-scale architectures such as, but not limited to, molecular and quantum-dot based transistors, switches and gates, in order to optimize space usage or enhance performance of mobile devices. A processor can also be implemented as a combination of computing processing units.
[0103] Examples (aspects) can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including instructions that, when performed by a machine (e.g., a processor with memory, an application-specific integrated circuit (ASIC) , a field programmable gate array (FPGA) , or the like) cause the machine to perform acts of the method or of an apparatus or system for concurrent communication using multiple communication technologies according to embodiments and examples described herein.
[0104] A first example is a UE, comprising: a memory; and processing circuitry, comprising the memory, configured to execute instructions that cause the UE to: initiate an initial access for a non-terrestrial network (NTN) satellite; and perform a cell search during the initial access on an NTN band based on one of a plurality of candidate values of synchronization signal block (SSB) periodicities.
[0105] A second example can include the first example, wherein the plurality of candidate values each correspond to a different specific band ID, respectively, or a region ID, according to a predefined association in a dataset.
[0106] A third example can include the first or second example, the processing circuitry is further configured to cause the UE to: initiate the cell search with a default candidate value of a default SSB periodicity; and in response to the cell search during the initial access failing to identify a cell on the NTN band with the default candidate value of the default SSB periodicity, perform the cell search with a higher SSB periodicity candidate value to identify a cell on the NTN band.
[0107] A fourth example can include any one or more of the first through third examples, the processing circuitry is further configured to cause the UE to: initiate the cell search with a legacy candidate value of a legacy SSB periodicity comprising 20 milliseconds (ms) ; in response to a cell search failure of the cell search, increase the legacy candidate value of the SSB periodicity to a higher candidate value from among a plurality of SSB periodicity candidate values; and perform one or more increasing iterations of the cell search with another candidate value by increasing the legacy candidate value up to a maximum candidate value of a maximum SSB periodicity until identifying a cell on the NTN band or until satisfying a threshold number of access attempts for the cell search failure.
[0108] A fifth example can include any one or more of the first through fourth examples, the processing circuitry is further configured to cause the UE to: initiate the cell search with a maximum candidate value of a maximum SSB periodicity among a plurality of SSB periodicity candidate values; in response to the cell search failing to acquire the NTN band with the maximum candidate value of the maximum SSB periodicity, perform the cell search with a lower SSB periodicity candidate value to acquire the NTN band; and perform one or more increasing iterations of the cell search with another candidate value by decreasing the maximum candidate value of the maximum SSB periodicity down to a legacy SSB periodicity candidate value until identifying a cell on the NTN band, or reaching a threshold number of access attempts for a cell search failure.
[0109] A sixth example can include any one or more of the first through fifth examples, wherein the UE is in an idle mode or an inactive mode when performing the cell search and the NTN band comprises a legacy NTN band comprising a legacy SSB periodicity, and the processing circuitry is further configured to cause the UE to: in response to identifying a NTN cell on the legacy NTN band with the legacy SSB periodicity, acquire a system information (SI) from the NTN cell; obtain an updated SSB periodicity from the SI; and acquire access to an updated NTN band based on the updated SSB periodicity from the SI.
[0110] A seventh example can include any one or more of the first through sixth examples, the processing circuitry is further configured to cause the UE to: in response to acquiring a NTN cell on the NTN band with the one of the plurality of candidate values of the SSB periodicities, process a system information (SI) from the NTN cell; record, in the memory, information of the NTN band that is associated with the plurality of candidate values of the SSB periodicities; and in response to a rebooting or repowering of the processing circuitry of the UE, perform the cell search during the initial access based on the information of the NTN band in the memory.
[0111] An eighth example can include any one or more of the first through seventh examples, the processing circuitry is further configured to cause the UE to: process a handover (HO) command while in a radio resource control (RRC) connected mode, the HO command comprising a SSB periodicity of a target cell from a serving cell of the NTN satellite; and perform a synchronization with the target cell based on the SSB periodicity from the HO command.
[0112] A ninth example can include any one or more of the first through eighth examples, the processing circuitry is further configured to cause the UE to: perform an information exchange with a serving cell of the NTN satellite to receive one or more SSB periodicities and one or more band IDs corresponding to the one or more SSB periodicities, respectively, for a handover to a target cell; and perform the handover to the target cell by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities, or using a legacy SSB periodicity of 5 ms when not provided an associated SSB periodicity of the target cell or NTN band by the serving cell of the NTN satellite with the one or more SSB periodicities and the one or more band IDs.
[0113] A tenth example can include any one or more of the first through ninth examples, the processing circuitry is further configured to cause the UE to: perform a handover from a serving cell to a target cell, based on a predefined mapping in a dataset of a plurality of NTN band IDs / NTN region IDs corresponding to a plurality of SSB periodicities, respectively; or perform the handover from the serving cell to the target cell based on a legacy SSB periodicity and increasing the legacy SSB periodicity incrementally in one or more handover synchronization iterations up to a maximum SSB periodicity in response to a synchronization to the target cell failing.
[0114] An eleventh example can include any one or more of the first through tenth examples, the processing circuitry is further configured to cause the UE to: perform a handover from a serving cell to a target cell based on a SSB periodicity and decreasing the SSB periodicity incrementally in one or more handover synchronization iterations down to a legacy SSB periodicity of 5 ms in response to a synchronization to the target cell failing.
[0115] A twelfth example can include any one or more of the first through eleventh examples, the processing circuitry is further configured to cause the UE to: process a RRC redirection command comprising a SSB periodicity of a target carrier frequency from the NTN satellite; and perform a synchronization with the target carrier frequency based on the SSB periodicity of the RRC redirection command.
[0116] A thirteenth example can include any one or more of the first through twelfth examples, the processing circuitry is further configured to cause the UE to: perform an information exchange with the NTN satellite to receive one or more SSB periodicities and one or more band IDs corresponding to the one or more SSB periodicities, respectively, for a RRC redirection to a target carrier frequency; and perform the RRC redirection to the target carrier frequency by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities, or using a legacy SSB periodicity of 20ms when the target carrier frequency is not provided with the one or more SSB periodicities.
[0117] A fourteenth example can include any one or more of the first through thirteenth examples, the processing circuitry is further configured to cause the UE to: perform a RRC redirection to a target carrier frequency based on a predefined mapping in a dataset of NTN band IDs / NTN region IDs corresponding to each of the plurality of candidate values of the SSB periodicities, respectively, or based on a legacy SSB periodicity and increasing the legacy SSB periodicity incrementally in one or more RRC redirection synchronization iterations up to a maximum SSB periodicity in response to a synchronization to the target carrier frequency failing.
[0118] A fifteenth example can include any one or more of the first through sixteenth examples, the processing circuitry is further configured to cause the UE to: perform an RRC redirection to a target carrier frequency based on a SSB periodicity and decreasing the SSB periodicity incrementally in one or more RRC redirection synchronization iterations down to a legacy SSB periodicity of 20 ms in response to a synchronization to the target carrier frequency failing.
[0119] A sixteenth example can be a method a UE comprising: initiating, via processing circuitry of the UE, an initial access for a non-terrestrial network (NTN) satellite; and performing a cell search during the initial access on an NTN band based on one of a plurality of synchronization signal block (SSB) periodicities that each map to a different NTN band, or a different NTN region, respectively.
[0120] A seventeen example can include the sixteenth example, further comprising: initiating the cell search with a legacy SSB periodicity comprising 20 milliseconds (ms) or with a maximum SSB periodicity; and in response to a cell search failure of the cell search: incrementally increasing the legacy SSB periodicity to a higher value from among the plurality of SSB periodicities by performing one or more additional iterations of the cell search up to the maximum SSB periodicity until acquiring the NTN band; or incrementally decreasing the maximum SSB periodicity to a lower value from among the plurality of SSB periodicities by performing one or more additional iterations of the cell search down to the legacy SSB periodicity until acquiring the NTN band.
[0121] An eighteenth example can include any one or more of the sixteenth through the seventeenth examples, further comprising: processing a handover (HO) command from a serving cell of the NTN satellite in a radio resource control (RRC) connected mode; obtaining an SSB periodicity of a target cell from the HO command; and performing a synchronization with the target cell based on the SSB periodicity from the HO command.
[0122] A nineteenth example can include any one or more of the sixteenth through the eighteenth examples, further comprising: processing a RRC redirection command comprising a SSB periodicity of a target carrier frequency from the NTN satellite; and perform a synchronization with the target carrier frequency based on the SSB periodicity of the RRC redirection command.
[0123] A twentieth example can be a baseband processor configured to, when executing instructions stored in a memory, perform operations comprising: initiating an initial access for a non-terrestrial network (NTN) satellite; and performing a cell search during the initial access on an NTN band based on one of a plurality of synchronization signal block (SSB) periodicities that each map to a different NTN band ID, or a different NTN region ID in a predefined dataset, respectively.
[0124] Moreover, various aspects or features described herein can be implemented as a method, apparatus, or article of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc. ) , optical disks (e.g., compact disk (CD) , digital versatile disk (DVD) , etc. ) , smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc. ) . Additionally, various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term “machine-readable medium” can include, without being limited to, wireless channels and various other media capable of storing, containing, and / or carrying instruction (s) and / or data. Additionally, a computer program product can include a computer readable medium having one or more instructions or codes operable to cause a computer to perform functions described herein.
[0125] Communications media embody computer-readable instructions, data structures, program modules or other structured or unstructured data in a data signal such as a modulated data signal, e.g., a carrier wave or other transport mechanism, and includes any information delivery or transport media. The term “modulated data signal” or signals refers to a signal that has one or more of its characteristics set or changed in such a manner as to encode information in one or more signals. By way of example, and not limitation, communication media include wired media, such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.
[0126] An exemplary storage medium can be coupled to processor, such that processor can read information from, and write information to, storage medium. In the alternative, storage medium can be integral to processor. Further, in some aspects, processor and storage medium can reside in an ASIC. Additionally, ASIC can reside in a user terminal. In the alternative, processor and storage medium can reside as discrete components in a user terminal. Additionally, in some aspects, the processes and / or actions of a method or algorithm can reside as one or any combination or set of codes and / or instructions on a machine-readable medium and / or computer readable medium, which can be incorporated into a computer program product.
[0127] In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding Figures, where applicable, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same, similar, alternative, or substitute function of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims below.
[0128] In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, systems, etc. ) , the terms (including a reference to a "means" ) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent) , even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature can have been disclosed with respect to only one of several implementations, such feature can be combined with one or more other features of the other implementations as can be desired and advantageous for any given or particular application.
Claims
1.A user equipment (UE) , comprising:a memory; andprocessing circuitry, comprising the memory, configured to execute instructions that cause the UE to:initiate an initial access for a non-terrestrial network (NTN) satellite; andperform a cell search during the initial access on an NTN band based on one of a plurality of candidate values of synchronization signal block (SSB) periodicities.2.The UE of claim 1, wherein the plurality of candidate values each correspond to a different specific band ID, respectively, or a region ID, according to a predefined association in a dataset.3.The UE of claim 1, the processing circuitry is further configured to cause the UE to:initiate the cell search with a default candidate value of a default SSB periodicity; andin response to the cell search during the initial access failing to identify a cell on the NTN band with the default candidate value of the default SSB periodicity, perform the cell search with a higher SSB periodicity candidate value to identify a cell on the NTN band.4.The UE of claim 1, the processing circuitry is further configured to cause the UE to:initiate the cell search with a legacy candidate value of a legacy SSB periodicity comprising 20 milliseconds (ms) ;in response to a cell search failure of the cell search, increase the legacy candidate value of the SSB periodicity to a higher candidate value from among a plurality of SSB periodicity candidate values; andperform one or more increasing iterations of the cell search with another candidate value by increasing the legacy candidate value up to a maximum candidate value of a maximum SSB periodicity until identifying a cell on the NTN band or until satisfying a threshold number of access attempts for the cell search failure.5.The UE of claim 1, the processing circuitry is further configured to cause the UE to:initiate the cell search with a maximum candidate value of a maximum SSB periodicity among a plurality of SSB periodicity candidate values;in response to the cell search failing to acquire the NTN band with the maximum candidate value of the maximum SSB periodicity, perform the cell search with a lower SSB periodicity candidate value to acquire the NTN band; andperform one or more increasing iterations of the cell search with another candidate value by decreasing the maximum candidate value of the maximum SSB periodicity down to a legacy SSB periodicity candidate value until identifying a cell on the NTN band, or reaching a threshold number of access attempts for a cell search failure.6.The UE of claim 1, wherein the UE is in an idle mode or an inactive mode when performing the cell search and the NTN band comprises a legacy NTN band comprising a legacy SSB periodicity, and the processing circuitry is further configured to cause the UE to:in response to identifying a NTN cell on the legacy NTN band with the legacy SSB periodicity, acquire a system information (SI) from the NTN cell;obtain an updated SSB periodicity from the SI; andacquire access to an updated NTN band based on the updated SSB periodicity from the SI.7.The UE of claim 1, the processing circuitry is further configured to cause the UE to:in response to acquiring a NTN cell on the NTN band with the one of the plurality of candidate values of the SSB periodicities, process a system information (SI) from the NTN cell;record, in the memory, information of the NTN band that is associated with the plurality of candidate values of the SSB periodicities; andin response to a rebooting or repowering of the processing circuitry of the UE, perform the cell search during the initial access based on the information of the NTN band in the memory.8.The UE of claim 1, the processing circuitry is further configured to cause the UE to:process a handover (HO) command while in a radio resource control (RRC) connected mode, the HO command comprising a SSB periodicity of a target cell from a serving cell of the NTN satellite; andperform a synchronization with the target cell based on the SSB periodicity from the HO command.9.The UE of claim 1, the processing circuitry is further configured to cause the UE to:perform an information exchange with a serving cell of the NTN satellite to receive one or more SSB periodicities and one or more band IDs corresponding to the one or more SSB periodicities, respectively, for a handover to a target cell; andperform the handover to the target cell by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities, or using a legacy SSB periodicity of 5 ms when not provided an associated SSB periodicity of the target cell or NTN band by the serving cell of the NTN satellite with the one or more SSB periodicities and the one or more band IDs.10.The UE of claim 1, the processing circuitry is further configured to cause the UE to:perform a handover from a serving cell to a target cell, based on a predefined mapping in a dataset of a plurality of NTN band IDs / NTN region IDs corresponding to a plurality of SSB periodicities, respectively; orperform the handover from the serving cell to the target cell based on a legacy SSB periodicity and increasing the legacy SSB periodicity incrementally in one or more handover synchronization iterations up to a maximum SSB periodicity in response to a synchronization to the target cell failing.11.The UE of claim 1, the processing circuitry is further configured to cause the UE to:perform a handover from a serving cell to a target cell based on a SSB periodicity and decreasing the SSB periodicity incrementally in one or more handover synchronization iterations down to a legacy SSB periodicity of 5 ms in response to a synchronization to the target cell failing.12.The UE of claim 1, the processing circuitry is further configured to cause the UE to:process a RRC redirection command comprising a SSB periodicity of a target carrier frequency from the NTN satellite; andperform a synchronization with the target carrier frequency based on the SSB periodicity of the RRC redirection command.13.The UE of claim 1, the processing circuitry is further configured to cause the UE to:perform an information exchange with the NTN satellite to receive one or more SSB periodicities and one or more band IDs corresponding to the one or more SSB periodicities, respectively, for a RRC redirection to a target carrier frequency; andperform the RRC redirection to the target carrier frequency by using the one or more SSB periodicities and the one or more band IDs corresponding to the one or more SSB periodicities, or using a legacy SSB periodicity of 20ms when the target carrier frequency is not provided with the one or more SSB periodicities.14.The UE of claim 1, the processing circuitry is further configured to cause the UE to:perform a RRC redirection to a target carrier frequency based on a predefined mapping in a dataset of NTN band IDs / NTN region IDs corresponding to each of the plurality of candidate values of the SSB periodicities, respectively, or based on a legacy SSB periodicity and increasing the legacy SSB periodicity incrementally in one or more RRC redirection synchronization iterations up to a maximum SSB periodicity in response to a synchronization to the target carrier frequency failing.15.The UE of claim 1, the processing circuitry is further configured to cause the UE to:perform an RRC redirection to a target carrier frequency based on a SSB periodicity and decreasing the SSB periodicity incrementally in one or more RRC redirection synchronization iterations down to a legacy SSB periodicity of 20 ms in response to a synchronization to the target carrier frequency failing.16.A method of a user equipment (UE) comprising:initiating, via processing circuitry of the UE, an initial access for a non-terrestrial network (NTN) satellite; andperforming a cell search during the initial access on an NTN band based on one of a plurality of synchronization signal block (SSB) periodicities that each map to a different NTN band, or a different NTN region, respectively.17.The method of claim 16, further comprising:initiating the cell search with a legacy SSB periodicity comprising 20 milliseconds (ms) or with a maximum SSB periodicity; andin response to a cell search failure of the cell search:incrementally increasing the legacy SSB periodicity to a higher value from among the plurality of SSB periodicities by performing one or more additional iterations of the cell search up to the maximum SSB periodicity until acquiring the NTN band; orincrementally decreasing the maximum SSB periodicity to a lower value from among the plurality of SSB periodicities by performing one or more additional iterations of the cell search down to the legacy SSB periodicity until acquiring the NTN band.18.The method of claim 16, further comprising:processing a handover (HO) command from a serving cell of the NTN satellite in a radio resource control (RRC) connected mode;obtaining an SSB periodicity of a target cell from the HO command; andperforming a synchronization with the target cell based on the SSB periodicity from the HO command.19.The method of claim 16, further comprising:processing a RRC redirection command comprising a SSB periodicity of a target carrier frequency from the NTN satellite; andperform a synchronization with the target carrier frequency based on the SSB periodicity of the RRC redirection command.20.A baseband processor configured to, when executing instructions stored in a memory, perform operations comprising:initiating an initial access for a non-terrestrial network (NTN) satellite; andperforming a cell search during the initial access on an NTN band based on one of a plurality of synchronization signal block (SSB) periodicities that each map to a different NTN band ID, or a different NTN region ID in a predefined dataset, respectively.
Citation Information
Patent Citations
Irregular SSB beam pattern for network energy saving
WO2023130445A1