Patent Description:
A Geosynchronous Equatorial Orbit (GEO) Satellite based <NUM> system may be deployed, for example, as part of a <NUM> system (5GS). In 5GS protocol, a user terminal (UT) can register with a Core Network (CN), and the registration process can include the CN providing the UT a registration area (RA). The RA is a collection of radio cells, each mutually adjacent to at least one other among the collection. As each cell is covered by a corresponding spot beam, the RA also defines a collection of spot beams. From the UT's perspective the RA defines an area in which the UT, when in its Connection Management (CM)-IDLE state, can move without having to notify the network. Since the notifications impose a signaling load, the allowing of the UT to move among multiple cells without notifying the network reduces signaling load on the system.

Communication functionality of a UT in CM-IDLE state, though, can be limited. For example, a CM-IDLE state UT cannot generally receive data packets. Therefore, when the <NUM> CN receives communication data for transmission to a CM-IDLE state UT, the Access and Mobility Management Function (AMF) must first send a page signal to the UT. The page signal, when received at the UT, causes the UT to switch to an active state to receive the data. When the UT is in CM-Idle state, though, the granularity of the AMF's knowledge of the UT's location is at the RA level. If the RA includes multiple cells, the AMF does not know which of the cells the UT is located in. Therefore, the page must be sent to all the RA's cells. Accordingly, for each of the multiple cells, the satellite radio access network (SRAN) that serves the cell sends the page signal, on an uplink to a satellite, for downlink transmission onto the spot beam that covers the cell. In satellite based <NUM> systems, this multi-cell, i.e., multi-beam, paging requirement can incur costs, in terms of satellite system bandwidth and system power.

Another cost in satellite based <NUM> systems relates to system overhead costs, and UT power and resource overhead costs of UT registration updates.

Accordingly, what is needed is a satellite based <NUM> system and method that can provide, among other features, reduced overhead/power paging of <NUM> UTs and, in some configurations, reduced overhead location reporting by <NUM> UTs.

<NPL>; <NPL>; and <CIT> each disclose satellite based systems.

An example of disclosed systems can include an SRAN, which can include a processor; and a memory that can be communicatively connected to the processor, and can store executable instructions that when executed by the processor cause the processor to receive, via a GEO satellite, a registration request from a UT and, in response, determine a current TA in which the UT is located, based at least in part on a content of the registration request, and send the registration request and an identification of the current TA to an AMF. The executable instructions can further include instructions that when executed by the processor can cause the processor to receive a registration accept from the AMF and, in response, forward the registration accept to the UT, the registration accept indicating a registration area for the UT; and instructions that when executed can cause the processor to receive from the AMF a page command for the UT that identifies the UT and, in response to determine a satellite beam for paging the UT, from among a plurality of satellite beams, based at least in part on the identifier of the current TA, and page the UT on said satellite beam for paging the UT. The executable instructions further include instructions that, when executed by the processor, cause the processor to: store a mapping of TAs to satellite beams. The UT page command includes the identification of the current TA, and determining the satellite beam for paging the UT includes: extracting the identification of the current TA from the UT page command, and applying the extracted identification of the current TA to the mapping of TAs to satellite beams.

An example of disclosed methods can include a method for satellite-based <NUM> resource conserving paging, comprising: receiving, by an SRAN, via a GEO satellite, a registration request from a UT; determining a current TA in which the UT is located, based at least in part on a content of the registration request; sending, from the SRAN to an AMF, the registration request and an identification of the current TA; and can include receiving a registration accept from the AMF, indicating a registration area for the UT, and forwarding the registration accept to the UT; receiving from the AMF a UT page command that identifies the UT and, in response, determining a satellite beam for paging the UT, from among a plurality of satellite beams, based at least in part on the identifier of the current TA, and paging the UT on said satellite beam for paging the UT. The method further includes: storing a mapping of TAs to satellite beams. The UT page command includes the identification of the current TA, and determining the satellite beam for paging the UT includes: extracting the identification of the current TA from the UT page command, and applying the extracted identification of the current TA to the mapping of TAs to satellite beams.

In the following detailed description, numerous specific details are set forth by way of examples to provide a thorough understanding of the disclosed subject matter. It may become apparent to persons of ordinary skill in the art, though, upon reading this disclosure, that one or more disclosed aspects may be practiced without such details. In addition, description of various example implementations according to this disclosure may include referencing of or to one or more known techniques or operations, and such referencing can be at relatively high-level, to avoid obscuring of various concepts, aspects and features thereof with details not particular to and not necessary for fully understanding the present disclosure.

As used in this disclosure, the terms "cell," "beam" and "spot beam" are interchangeable, as each cell is covered by, i.e., is within one spot beam and each spot beam covers one cell. The cell can be uniquely identified by the SRAN from which the UT receives radio signals.

As used in this disclosure, the phrase "based on" will be understood to mean based at least in part on, except where otherwise stated or made clear from the context to have a different meaning.

Systems and methods according to this disclosure can provide TA level tracking of CM-Idle state UTs, combined with TA-based single beam selection and single beam paging of CM-Idle state UTs, instead of current paging of a subject CM-Idle-state UT, which is on all beams covering any portion of the subject UT's current RA. In an implementation, features in the TA-based tracking can include a particular initial registration. In the initial registration, an SRAN can receive a registration request from a subject UT and, in response, can determine the current TA in which the requesting UT is located. In an aspect, the determination can be based, at least in part, on a content of the registration request. An initial registration can also include sending, from the SRAN to the AMF, the registration request and an identification of the determined current TA, followed by receiving at the SRAN a registration accept from the AMF, the registration accept indicating a registration area for the UT, whereupon the SRAN can forward the registration accept to the UT. In an implementation, after the subject UT has switched to CM-Idle state, paging of the UT can include receiving at the SRAN from the AMF a UT page command that identifies the subject UT. The paging can also include the SRAN, in response to the paging command, looking up or otherwise identifying the UT's current TA, followed by the SRAN selecting, for the paging, one beam among a plurality of beams, namely, the beam that covers the identified TA.

An example implementation can additionally or alternatively include a particularly configured UT, a particularly configured SRAN, or both, wherein the UT, before sending a registration request, can send the SRAN a location report that includes the UT's location. The particularly configured SRAN, in response to the location report, can determine the UT's current TA and send the TA to the UT in a location accept. The particularly configured UT can subsequently include, e.g., in its initial registration request to the SRAN, the TA earlier received from the SRAN. The SRAN can forward the registration request, together with its included TA, to the AMF. In an aspect, the UT can encrypt its location in the location report message. This can provide security against a man-in-the-middle determining the UT location.

In another example implementation, the AMF can be particularly configured, or both the SRAN and the AMF can be particularly configured to maintain, in the AMF, an updated TA-level indication of a CM-IDLE state UT. Technical features can include offloading of processing and storage of per UT current TA, from the SRAN to the AMF.

<FIG> is a high-level schematic of an example satellite-based <NUM> system (hereinafter "system <NUM>"). The system <NUM> can include an SRAN <NUM> that can be communicatively connected via a first interface <NUM> to an AMF <NUM>, and communicatively connected via a second interface <NUM> to a <NUM> User Plane Function (UPF) <NUM>, which accesses external IP networks <NUM>. The first interface <NUM> can be, for example, a <NUM> N2 standard interface, and the second interface <NUM> can be, for example, a <NUM> N3 standard interface.

The system <NUM> can include a GEO satellite <NUM>, or other elevated altitude radio frequency (RF) transceiver/receiver. The SRAN <NUM> can transmit various content and control data to the GEO satellite <NUM> over a forward uplink (not separately visible) resource of a two-way "feeder link" <NUM>. The GEO satellite <NUM> can, in turn, provide two-way "service links" <NUM> (not individually visible in <FIG>) within a pattern of spot beams the satellite <NUM> establishes over a service area (not separately labeled in <FIG>). The pattern of spot beams forms a corresponding pattern of cells, such as the <FIG> pattern that includes a first cell <NUM>-<NUM>, second cell <NUM>-<NUM>, third cell <NUM>-<NUM>, and fourth cell <NUM>-<NUM> (hereinafter collectively "cell(s) <NUM>"). The pattern of spot beams can be configured such that the cells <NUM> are hexagonal, as visible in <FIG>. Interface between the feeder link <NUM> and service links <NUM> can be provided by satellite air interface <NUM>. One example satellite air interface <NUM> can be GMR-<NUM><NUM>, which is an evolution of the GMR-<NUM> air interface standards; GMR-<NUM><NUM> has been adopted as a mobile satellite system standard by the European Telecommunications Standards Institute (ETSI) and the International Telecommunications Union (ITU).

<FIG> shows three UTs, numbered respectively as UT <NUM>-<NUM>, UT <NUM>-<NUM>, and UT <NUM>-<NUM> (collectively "UTs <NUM>"). The visible population of three UTs <NUM> is only for illustration, and can be representatives from a much larger population of UTs (not explicitly visible in <FIG>). The UTs <NUM> can be mobile, e.g., placed on, or otherwise supported by a vehicle, aircraft, ship, boat, or other means of transport or conveyance.

<FIG> shows a graphical overlay on the <FIG> cells <NUM> of an example configuration of RAs, each RA being formed of a particular set of TAs. In the example configuration, a first list or set of TAs, visible in <FIG> as "TA1," "TA2," and "TA3," are a first RA, labeled "RA1. " A second set of TAs, visible in <FIG> as "TA4," "TA5," "TA6," and "TA7, are a second RA, which is labeled "RA2. " The TAs forming RA1 result in RA1 extending over or into multiple cells, these being the first cell <NUM>-<NUM> and a portion of the third cell <NUM>-<NUM>. The TAs forming RA2 result in RA2 also extending over or into multiple cells, these being the second cell <NUM>-<NUM>, fourth cell <NUM>-<NUM>, and fifth cell <NUM>-<NUM>.

For purposes of description, TA1, TA2, and TA3 will be alternatively referenced, respectively, as "first RA first TA," "first RA second TA," and "first RA third TA. " Tracking areas TA4, TA5, TA6, and TA7 will be alternatively referenced, respectively, as "second RA first TA," "second RA second TA," "second RA third TA," and "second RA fourth TA. " For convenience the first RA first TA, second TA, and third TA will be alternatively recited, respectively, as "RA1/TA1," "RA1/TA2," and "RA1/TA3. " Likewise, the second RA first TA, second TA, third TA, and fourth TA. " will be alternatively recited, respectively, as "RA2/TA4," "RA2/TA5," "RA2/TA6," and "RA2/TA7.

As described above, the UTs <NUM> can be mobile, and the locations visible in <FIG> of the UTs <NUM> relative to the example RAs and TAs can be a snapshot state. The <FIG> state includes UT <NUM>-<NUM> being located in RA1/TA1, UT <NUM>-<NUM> located in RA1/TA3, and UT <NUM>-<NUM> located in the RA2/TA4. In an operation of the system <NUM>, each of the UTs <NUM> can register with AMF <NUM>. Each of the UTs <NUM> can also re-register, for example, in response to the UT moving a threshold distance from the location at which it most recently registered. An example UT <NUM> registration can include the UT transmitting a registration request message to the SRAN <NUM>, or other SRAN (not visible in <FIG>) serving the cell in which the UT <NUM> is located. The SRAN <NUM> can forward the registration request to the AMF <NUM>, along with identifiers of the UT <NUM>'s current TA and current cell identifier. The AMF <NUM>, in response, can assign the requesting UT an RA, i.e., a particular set of TAs within which the UT <NUM> can move while in the CM-IDLE state without needing to inform the network. In the <FIG> configuration, an example RA assignment can be one among RA1 and RA2. The AMF <NUM> communication of the assignment can include an identifier of the assigned RA, and a list of the RA's TAs.

Each of the UTs <NUM> can be RRC Active upon completion of the registration and, as such, can receive data from the AMF <NUM> received from the core network elements. Each UT <NUM> can also switch from RRC Active to the CM-IDLE state, for example, in response to detecting inactivity. As also described above, the UT <NUM> in the CM-IDLE state generally cannot receive data transmission. Therefore, for data to be delivered to a UT <NUM> currently in the CM-IDLE state, the AMF <NUM> must first page the UT. The AMF, though, only knows the RA in which CM-IDLE state UT <NUM> is located. The AMF <NUM> must therefore send the page signal to all SRANs having jurisdiction of any of the cells into which the UT <NUM>'s current assigned RA extends. This incurs costs in satellite system bandwidth and system power.

As illustration of such costs, an example will assume UT <NUM>-<NUM> has registered, and its assigned TAs are the TAs forming RA2, and UT <NUM>-<NUM> has switched to the CM-IDLE state, and a data addressed to UT <NUM>-<NUM> arrives at the AMF <NUM>, e.g., via the UPF <NUM> and second interface <NUM>, while the UT is in the CM-IDLE state. Since UT <NUM>-<NUM> is in the CM-IDLE state, the AMF <NUM> must first page UT <NUM>-<NUM> to cause the UT to switch to the CM-CONNECTED/RRC-Active state to receive the data. The AMF <NUM>, however, does not know which of the four TAs of RA2 in which UT <NUM>-<NUM> is located, i.e., does not know UT <NUM>-<NUM> is located in RA2/TA4. The AMF <NUM> only knows that the CM-IDLE state UT <NUM>-<NUM> is in RA2. Therefore, the AMF <NUM> page of UT <NUM>-<NUM> causes the SRAN <NUM> to send a page to all <NUM> of the cells <NUM> into which RA2 extends, i.e., second cell <NUM>-<NUM>, third cell <NUM>-<NUM>, fourth cell <NUM>-<NUM>, and fifth cell <NUM>-<NUM>. This is a non-productive expenditure of system <NUM> resources.

<FIG> is a logic diagram of a flow <NUM> of operations in a process of the above-described UT registration and subsequent paging of a CM-IDLE state UT <NUM>. Description of an example instance of the flow <NUM> will refer to UT <NUM>-<NUM>. It will be understood that description using either UT-<NUM> or UT-<NUM> would be substantially identical. An instance of the flow <NUM> can proceed from a start state <NUM> to a sending by UT <NUM>-<NUM> of an initial registration request <NUM> to the AMF <NUM>, e.g., over a reverse uplink resource (not explicitly visible in <FIG>) of the service link <NUM>, then from the GEO satellite <NUM> to the SRAN <NUM> over a reverse downlink resource of the feeder link <NUM>. The SRAN <NUM>, in response, can forward <NUM> the registration request to the AMF <NUM>. The AMF <NUM> can respond by registration operations <NUM>, followed by sending a registration accept <NUM>. The registration operations <NUM> can be according to standard <NUM> techniques and, therefore, further detailed description is omitted. It will be assumed that the registration accept <NUM> assigns RA2 to UT <NUM>-<NUM>. The SRAN <NUM>, in response to the registration accept <NUM> can forward <NUM> the registration accept to UT <NUM>-<NUM>. Upon UT <NUM>-<NUM> receipt of the forwarded registration accept <NUM>, UT <NUM>-<NUM> can be registered in RA2. The UT <NUM>-<NUM> can thereafter move among RA2/TA4, RA2/TA5, RA2/TA6, and RA2/TA7 without having to re-register with the AMF <NUM>.

At some time after the above-described registration process, UT <NUM>-<NUM> can switch <NUM> to the CM-IDLE state. The switch <NUM> to CM-IDLE can be in response to a UT inactivity condition, such as defined under 3GPP TS <NUM>. It will be assumed that while UT <NUM>-<NUM> is in the CM-IDLE state, other core network elements receive, at <NUM>, downlink data having UT <NUM>-<NUM> as the indicated destination. The CN elements, in response, can send an NamfN1N2MessageTransfer <NUM> to the AMF <NUM>. The AMF <NUM> response to the NamfN1N2MessageTransfer <NUM> can include sending an NamfN1N2MessageTransferResponse <NUM> to the core network elements, and sending a page command <NUM> to SRAN <NUM>. The page command is for the SRAN <NUM> to send a page to UT <NUM>-<NUM> to all <NUM> cells <NUM> covered by RA2, these being second cell <NUM>-<NUM>, third cell <NUM>-<NUM>, fourth cell <NUM>-<NUM>, and fifth cell <NUM>-<NUM>. This is due AMF <NUM> awareness of CM-IDLE UT <NUM>-<NUM> location being only that UT <NUM>-<NUM> is in RA2, the RA that UT <NUM>-<NUM> was assigned. The AMF <NUM> response <NUM> to the NamfN1N2MessageTransfer <NUM> therefore sends a page command <NUM> to the SRAN <NUM>, and any other SRAN (not explicitly visible in <FIG>) having jurisdiction over any of the four cells, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> into which RA2 extends. This is a non-productive expenditure of system <NUM> resources.

Systems and methods in accordance with this disclosure can provide, without limitation, via features such as a TA-level tracking of UTs in CM-IDLE state, and corresponding TA-specific beam selection for UT paging, substantial reduction of duplicative expenditure of system resources.

In current 5GS techniques, a UT discovers that it has moved out of the current RA by listening to the System Information Blocks (SIBs) broadcast in the current radio cell. The SIBs transmitted by the SRAN contain the TA identifier of the current cell. If the TA identifier in the SIB is not in the UT's current registration TA list, the UT <NUM> initiates a re-registration process. Each re-registration process, with associated communications between the UT <NUM>, the SRAN <NUM> and AMF <NUM>, can incur satellite system bandwidth and overhead costs.

Features provided by disclosed systems and methods can also include a particular conditioning, at the UT, for transmitting location reports. Benefits of the particular conditioned transmission of UT location reports can include, without limitation, substantial reduction in UT transmission of location reports, and corresponding reduction in the reports' concomitant consumption of system resources.

In one implementation of conditioned transmission of UT location reports, in accordance with this disclosure, vertices of all TAs can be broadcast in System Information Blocks (SIBs) by an SRAN. A particularly configured UT can perform cell selection/reselection by first comparing its GPS position with the SIB broadcast information. For initial selection, the configured UT can send a registration request to the SRAN which, in response, can determine the TA based on cell identification, in combination with the identity of the beam from which the registration request was received. The SRAN can append the UT TA to the registration accept it sends to the AMF <NUM>. The AMF <NUM>, in response, will assign an RA (multiple TAs). The UT does not need to update its location if its location is within the assigned RA. When a paging signal arrives from the AMF <NUM>, the SRAN determines, for example from a mapping it can establish, the UTs current TA and sends the paging signal only to the correct beam to reach the UT.

In an aspect, implementation of conditioned transmission of UT location reports can include particularly configured UTs that can include an adaptive distance threshold logic. Features of the adaptive distance threshold logic can include adaptive setting of the distance threshold based, for example, on the UT's distance from the border of the advertised cell vertices. Benefits of this feature include, but are not limited to, reduction in UT need to initiate cell reselection.

<FIG> is a block schematic of one example implementation of a satellite-based <NUM> high efficiency paging, tracking, and communication system <NUM> (hereinafter "system <NUM>") in accordance with this disclosure. To avoid obfuscation with detailed description of a new cell and RA configuration, various features and operations of system <NUM> will be described using the <FIG> configuration of cells <NUM>, and example configuration of RA1 and RA2.

Features provided by the system <NUM> can include, as described in greater detail in paragraphs that follow, resource conserving, reduced overhead/power paging of <NUM> UTs. Features provided by the system <NUM> can also include reduced overhead location reporting by <NUM> user terminals, and reduced re-registration.

The system <NUM> can include a selective beam paging SRAN <NUM>, which can be communicatively connected via the first interface <NUM> to the AMF <NUM>, and communicatively connected via the second interface <NUM> to the <NUM> UPF <NUM> to access external IP networks <NUM>. In one or more implementations, certain functionalities of the <FIG> SRAN <NUM> can be carried into the selective beam paging SRAN <NUM>. Further detailed description of such functionalities will be omitted except where incidental to description of features or operations particular to the selective paging SRAN <NUM>. To reduce repetition of "selective beam paging" in the context of "selective beam paging SRAN <NUM>," subsequent description will alternatively recite "selective beam paging SRAN <NUM>" as "SB paging SRAN <NUM>.

To avoid obscuring concepts with description of protocol not necessarily specific to practices according to this disclosure, description of example operations of the system <NUM> will assume UT registration requests are configured to conform to or to be compatible with 3GPP TS <NUM>. This is only for purposes of example and is not intended as a limitation on practices in accordance with this disclosure or its appended claims.

An implementation of the SB paging SRAN <NUM> can include a TA/location determination logic <NUM>. Functionality of the TA/location determination logic <NUM> can include determining the current TA in which the UT <NUM>-<NUM>, UT <NUM>-<NUM>, and UT <NUM>-<NUM> (collectively "UT <NUM>" or "UTs <NUM>") are located. As described in greater detail later, the TA/location determination logic <NUM> can be configured to determine the UT <NUM> current TA from a location report from the UT <NUM> that indicates the UT <NUM>'s geolocation. The SB paging SRAN <NUM> can be configured to include the UT <NUM>'s current TA in the forwarding to the AMF <NUM> of the registration request. In an implementation, the UTs <NUM> can also include a UT location detection/ reporting logic <NUM>. Functionalities of the UT location detection/reporting logic <NUM> can include detection of the UT <NUM>'s current location and sending location reports as identified above. The UT location detection/reporting logic <NUM> can also be configured to determine the UT <NUM>'s current TA and to include that TA in its location reports and in its initial and subsequent registration requests to the SB SRAN <NUM>.

Functionalities of the UT location detection/reporting logic <NUM> can include adaptive distance threshold logic, in which the distance threshold the UT <NUM> must move to initiate a location report can be adaptively set. In an aspect, the adaptive setting can be based, at least in part, on the UT's distance from the border of the cell vertices advertised via the cell vertices advertised by system information broadcast (SIB). For purposes of description, UTs <NUM> with the UT location detection/reporting logic <NUM> will be alternatively referred to as "resource conserving UTs" UTs <NUM>. To reduce repetition of "resource conserving" in the context of "resource conserving UT <NUM>," subsequent description will alternatively recite "RSC UT <NUM>.

In an implementation, the RSC UTs <NUM> can be configured to send to the SB paging SRAN <NUM> a location report prior to initial registration. The SB paging SRAN <NUM> can be configured to respond by determining the current TA of the UT <NUM>, e.g., using the TA determination logic <NUM>, based on the location report together with the identity of the cell in which the location report was received. The SB paging SRAN <NUM> can be configured to send the determined TA to the RSC UT <NUM>. The RSC UT <NUM> can subsequently, when it sends its initial registration request, include the TA it received earlier from the SB paging SRAN <NUM>.

The SB paging SRAN <NUM> can be configured to respond to receipt of a registration request by forwarding the request to the AMF <NUM>, together with the UT <NUM>'s current TA that the SB paging SRAN <NUM> determined from, or extracted from the request. The SB paging SRAN <NUM> can subsequently receive from the AMF <NUM> a registration accept that can define an RA for the UT <NUM>. The SB paging SRAN <NUM> can be configured to forward the registration accept content, including the newly assigned RA, to the UT.

Upon completion of the UT <NUM> registration process, the UT <NUM> can be in a CM-CONNECTED/RRC-Active state in which the UT can receive data from the AMF <NUM>, via transmission from the SB paging SRAN <NUM>. At some time subsequent to the above-described registration process, the UT <NUM> can switch from RRC Active to CM-IDLE state, for example, in response to detecting inactivity. Subsequent to the RSC UT <NUM> switching to a CM-IDLE state, the UT SB paging SRAN <NUM> can receive from the AMF <NUM> a page command for the RSC UT <NUM>. The SB paging SRAN <NUM> can be configured to respond to the page command by determining a satellite beam, e.g., selected among <FIG> satellite beams <NUM>, for paging the RSC UT <NUM>. The SB paging SRAN <NUM> can be configured to perform the selection by a look-up or other process for determining the subject RSC UT <NUM>'s current TA, followed by look-up or reference to a TA-to-satellite beam table or record. The SB paging SRAN <NUM> can be configured to then page the RSC UT <NUM> on the determined satellite beam.

Technical benefits provided by the above-described SB paging SRAN <NUM>, logic <NUM> and operations of the UTs <NUM> with location reporting logic <NUM> can include, without limitation, beam-selective, resource conserving, lowered cost paging and activation of registered CM-IDLE state UTs to receive transmission of UT-destined packets.

<FIG> is a flow diagram of operations in processes <NUM> in satellite based UT <NUM> registration, tracking, paging, and packet transmission in implementations of systems and methods in accordance with this disclosure. For convenience, example instances of the flow <NUM> will be described in reference to the system <NUM>. Instances will assume, as a start state, a RSC UT <NUM> that is within one of the cells <NUM> and has not yet registered with the AMF <NUM>. In describing example operations that relate to or reference a particular one of the RSC UTs <NUM>, for example, a RSC UT <NUM> from which a registration request is received, the UT <NUM> will be referred to as "the subject RSC UT <NUM>. " For convenience, the registration request will be alternatively referenced as "REG RQST," in accordance with the <FIG> labeling.

Operations in the flow <NUM> can proceed from a start state <NUM> to <NUM> upon the SB paging SRAN <NUM> receiving from a subject RSC UT <NUM> a REG RQST. The flow <NUM> can proceed from <NUM> to <NUM>, where the SB paging SRAN <NUM> operations can determine the subject UT <NUM>'s current TA. The operations at <NUM> can be configured to determine the current TA based, at least in part, on a content of the REG RQST. Referring to <FIG>, the labeling visible on block <NUM> abbreviates "based at least in part" as "BTLP. " In one example implementation RSC UT <NUM> operations at <NUM> can include in the REG RQST an identity of the RSC UT <NUM>'s current cell. In such implementation, the system <NUM> can provide the SB paging SRAN <NUM> (appearing in <FIG> as "SB SRAN") an identity of the particular spot beam on which the REG RQST was received. In another implementation of operations at <NUM>, the RSC UTs <NUM> can send an encrypted location report to the SB paging SRAN <NUM>, prior to sending an initial REG RQST to the AMF <NUM>. The location report can include the subject RSC UT <NUM>'s geolocation. The SB paging SRAN <NUM> can be configured to respond to the location report by determining the RSC UT <NUM>'s TA, e.g., by use of a geolocation-to-TA database (not explicitly visible in <FIG>), and then including the determined TA, in an encrypted location report response the SB paging SRAN <NUM> sends to the RSC UT <NUM>. Further to this implementation, the RSC UT <NUM> can be configured to include the received TA in the REG RQST it sends for reception at <NUM> by the SB paging SRAN <NUM>.

After the SB paging SRAN <NUM> determines the subject RSC UT <NUM>'s current TA at <NUM>, the flow <NUM> can proceed to <NUM> where the SB paging SRAN <NUM> can send the REG RQST, with the determined TA appended or included, to the AMF <NUM>. After the sending at <NUM>, the SB paging SRAN <NUM> can, as represented by block <NUM>, wait for receipt of a registration accept from the AMF <NUM>. Description will assume, only for purposes of example, that registration accept is in accordance or compatible with 3GPP TS <NUM>.

It will be understood that "wait," in the context of block <NUM> functionality, does not necessarily require the SB paging SRAN <NUM> terminate operations until receipt of the registration accept. For example, during the wait at block <NUM> the SB paging SRAN <NUM> may perform various other operations, communications, and processes (not visible in <FIG>). These can include, for example, other instances of the flow <NUM> for other UTs. Upon receipt of the registration accept from the AMF <NUM>, the flow <NUM> can proceed to <NUM> and send the registration accept to the RSC UT <NUM>. The RSC UT <NUM> may respond to receipt of the registration accept forwarded at <NUM> by transmitting a registration complete (not visible in <FIG>) to the SB paging SRAN <NUM>.

Subsequent to the registration associated in response to <NUM>, the subject RSC UT <NUM> can switch, e.g., in association with inactivity, to the <NUM> CM-IDLE state. The trigger for switching to the CM-IDLE state, and the switching operations, are not necessarily specific to practices according to this disclosure and can be performed, for example, using standard <NUM> techniques.

When the subject registered RSC UT <NUM> is in the CM-IDLE state, core network elements of the system <NUM> can receive at <NUM> downlink data addressed to the RSC UT <NUM>. The AMF <NUM>, in response, can send a page command to the SB paging SRAN <NUM>. In an aspect, the page command can include an S-TMSI (Temporary Mobile Subscriber Identity) assigned to the RSC UT <NUM> and an identifier of the most recent RA assigned to the UT <NUM>. The SB paging SRAN <NUM>, upon receiving the page command for the subject UT <NUM>, can proceed from <NUM> to <NUM>, and can apply a process according to this disclosure for determining a best beam, among the plurality of beams <NUM>, for sending a page to the registered RSC UT <NUM>.

<FIG> is a sequence diagram illustrating a flow <NUM> of operations in UT registration, tracking, paging, and data delivery, in satellite-based <NUM> systems and methods in accordance with this disclosure. Example operations of the flow <NUM> will be described in reference to <FIG> and <FIG>. An instance of the <NUM> can begin with any RSC UT <NUM>, e.g., RSC UT <NUM>-<NUM>, sending at <NUM> an initial REG RQST <NUM> to the SB paging SRAN <NUM>. The SB paging SRAN <NUM>, in response, can determine the present TA of the subject RSC UT <NUM>, based on UT current TA indicative information included in, or associated with the SB paging SRAN <NUM>'s reception of the REG RQST <NUM>, or both. In one or more implementations, the RSC UTs <NUM> can be configured to include, as the RSC UT's TA indicative information in the REG RQST <NUM>, a UT current cell identifier. In an implementation, the SB paging SRAN <NUM> can be provided with information identifying the specific satellite beam or cell <NUM> in which the REG RQST <NUM> was received. The SB paging SRAN <NUM> can include logic, e.g., SB paging SRAN <NUM> logic <NUM>, configured for resolving the RSC UT <NUM>'s current TA from the UT current cell identifier and the above-described beam identification. In another implementation, described in greater detail in subsequent paragraphs, the UT TA indicative information carried in the REG RQST <NUM> can include a TA identifier inserted by the subject RSC UT <NUM>.

The SB paging SRAN <NUM>, upon receiving the REG RQST <NUM>, can send to the AMF <NUM> a forwarded REG RQST <NUM>, which can include the determined current TA of the RSC UT <NUM>. Upon AMF <NUM> receiving the forwarded REG RQST <NUM>, the flow <NUM> can perform at <NUM> remaining operations in the UT registration procedure. Operations at <NUM> can be in accordance with known <NUM> UT registration techniques and can include the AMF <NUM> determining an RA for the subject RSC UT <NUM>, and the AMF <NUM> including the RA in a registration accept <NUM> the AMF <NUM> can send back to the SB paging SRAN <NUM>. The registration accept <NUM> can include the S-TMSI of the requesting RSC UT <NUM>. AMF <NUM> assignment of the S-TMSI can be, for example, according to known <NUM> AMF S-TMSI assignment techniques. The SB paging SRAN <NUM>, in response to the registration accept <NUM>, can at <NUM> forward the registration accept <NUM>, with its included AMF-assigned RA and AMF-assigned TMSI, to the subject RSC UT <NUM>. The RSC UT <NUM> can, but does not necessarily, respond to the forwarded registration accept <NUM> by transmitting a registration complete (not visible in <FIG>) to the SB paging SRAN <NUM>.

Upon receipt of the forwarded registration accept <NUM> the subject RSC UT <NUM> can switch to the <NUM> CM-CONNECTED state. If the core network elements deliver data, the data can be immediately delivered to the <NUM> CM-CONNECTED RSC UT <NUM>, without paging. Operations associated with the delivery can include packets being sent by the UPF <NUM>, which can be handling the user plane, to SB paging SRAN <NUM>, and the AMF <NUM> handling the control plane. Since the RSC UT <NUM> is in the CM-CONNECTED state, the AMF <NUM> can notify the UPF <NUM> to proceed to send the data to the RSC UT <NUM> via the SB paging SRAN <NUM>.

While in the CM-CONNECTED state, the registered subject RSC UT <NUM> can send one or more location reports to the SB paging SRAN <NUM>. Such location reports can include the registered RSC UT <NUM>'s S-TMSI. <FIG> shows, as an example, a location report <NUM> from the registered RSC UT <NUM> to the SB paging SRAN <NUM>. The location report <NUM> can indicate the registered RSC UT <NUM>'s current cell and assigned S-TMSI.

In an aspect, the SB paging SRAN <NUM> can be configured to not forward the location report <NUM> to the AMF <NUM>, and configured to instead notify the AMF <NUM> of UT movement only by forwarding registered subject RSC UT <NUM> requests for mobility registration updating, as described in greater detail in later paragraphs. The SB paging SRAN <NUM> can be further configured to respond to the location report <NUM> by applying, at <NUM>, operations for determining the registered subject RSC UT <NUM>'s current TA. Operations at <NUM> can be configured to determine the TA based on or utilizing, for example, the registered RSC UT <NUM>'s S-TMSI and indication of current cell carried by the location report <NUM>. The SB paging SRAN <NUM> can also be configured to send to the registered subject RSC UT <NUM> a location response <NUM> that includes the UT's current TA determined at <NUM>. It will be understood that the meaning of "update" and variants thereof, as used herein in contexts such as but not limited to operations <NUM>, can include a first instance and can include instances wherein a selective adjustment maintains an adjustment object or target at a current state or value.

Referring to <FIG>, flow <NUM> operations subsequent to the above-described registration can include the registered subject RSC UT <NUM> switching at <NUM> from the CM-CONNECTED state to the CM-IDLE state, for example, due to inactivity of the RSC UT <NUM>. Subsequent to the registered subject RSC UT <NUM> switching at <NUM> to CM-IDLE state, core network elements of the system <NUM> can receive at <NUM> downlink data addressed to the registered RSC UT <NUM>. The core network elements can respond, for example, by sending to the AMF <NUM> a Namf_Comm_N1N2MessageTransfer service request <NUM>.

The Namf_Comm_N1N2MessageTransfer service request <NUM> can be defined, for example, in accordance with 3GPP TS <NUM>. The AMF <NUM>, in response, can send to the core network elements a Namf_Comm_N1N2MessageTransfer Response <NUM>, followed by sending a page request <NUM> to the SB paging SRAN <NUM>. The page request <NUM> can include the RA and can carry the S-TMSI the AMF <NUM> assigned to the registered subject RSC UT <NUM>. The SB paging SRAN <NUM> can be configured to respond to the page request <NUM> by applying at <NUM> operations for determining a best beam, among the plurality of <FIG> beams <NUM>, for sending a page to the registered subject RSC UT <NUM>. In an aspect, determination at <NUM> can be based on reference to a TA-to-beam mapping using the registered subject RSC UT <NUM>'s S-TMSI included in the page request <NUM>.

After determining at <NUM> the best beam for paging the registered subject RSC UT <NUM> the flow <NUM> can proceed to <NUM>, where the SB paging SRAN <NUM> can send a paging command to the GEO satellite <NUM>, specifying the determined best beam. After the sending at <NUM>, the flow <NUM> can proceed to <NUM>, where remaining <NUM> UT CM-IDLE to CM-CONNECTED registration operations can be performed. The flow <NUM> can then proceed from <NUM> to <NUM>, where the core network elements can send the downlink data received at <NUM> to the SB paging SRAN <NUM> and can then proceed to <NUM>, where the SB paging SRAN <NUM> can transmit the data to the now RRC-ACTIVE state subject RSC UT <NUM>.

It will be understood that <FIG> showing one instead of, for example, a plurality of instances of the location report <NUM>, is for convenience of description, and is not intended as a limitation of practices in accordance with this disclosure.

<FIG> is a sequence diagram illustrating an example sequence <NUM> that can include portions of the above-described sequence <NUM>, with alternative UT initial registration portions, for UT registration tracking, paging, and data delivery in satellite-based <NUM> systems and methods in accordance with this disclosure. The <FIG> example sequence <NUM> includes portions of the flow <NUM> initial registration sequence, e.g., operations <NUM>-<NUM>, and location update operations at <NUM>-<NUM>, as well as switching to CM-IDLE at <NUM>. The <FIG> example sequence <NUM> also includes data arrival, paging and data delivery operations <NUM>-<NUM>. This is for convenience in description, e.g., to avoid redundancy or obfuscation with added examples of features or blocks already described in the context of <FIG> and is not intended as a limitation on the scope of practices in accordance with the flow <NUM>.

Features of the sequence <NUM> can include the RSC UT <NUM> sending a location report <NUM> to the SB paging SRAN <NUM>, prior to the RSC UT <NUM> sending an initial REG RQST, e.g., the flow <NUM> sending of the initial REG RQST <NUM>. The RSC UT <NUM> can also be configured to determine, prior to operations at <NUM>, the RSC UT <NUM>'s geolocation and to include in the geolocation in the location report <NUM>. The SB paging SRAN <NUM> can be configured to respond to the location report <NUM> by proceeding to <NUM> where the logic <NUM> of the SB paging SRAN <NUM> can use the RSC UT <NUM>'s geolocation to look up or otherwise access a geolocation-to-TA database (not explicitly visible in <FIG>). SB paging SRAN <NUM> operations <NUM> can include inserting the determined TA into a location report response <NUM>, and sending such response to the RSC UT <NUM>.

In an implementation, the RSC UT <NUM> can be configured to store the TA included in the location report response received at <NUM>. The RSC UT <NUM> can be further configured such that, when it generates and sends a REG RQST such as <NUM>, the stored TA is included in that REG RQST. This differs from the REG RQST <NUM> sent by the RSC UT <NUM> in the <FIG> sequence <NUM>. Operations by the SB paging SRAN <NUM> in response to receiving the REG RQST <NUM> can therefore differ from operations the SB paging SRAN <NUM> applied upon receiving the <FIG> flow <NUM> REG RQST <NUM>. As an example, in the sequence <NUM>, SB paging SRAN <NUM> operations can simply extract the TA from the REG RQST <NUM> and append it to the forwarded REG RQST <NUM>. In one or more implementations the SB paging SRAN <NUM> can be configured to store the TA received in the REG RQST <NUM>. In other implementations, one example of which will be described in greater later in this disclosure, the SB paging SRAN <NUM> can be configured to discard or otherwise not maintain a stored TA for the RSC UT <NUM>.

<FIG> is a flow diagram illustrating a sequence <NUM> of operations in UT registration, tracking, paging, and data delivery, with features of movement-based mobility registration updating, for satellite-based <NUM> systems and methods for satellite resource conserving <NUM> UT paging. The <FIG> example sequence <NUM> can be implemented, and will be described accordingly, as an extension of the above-described <FIG> sequence <NUM>. Description of an instance of the sequence <NUM> will assume that operations <NUM>-<NUM> have been performed, and that prior to time "T1" the subject UT has switched back to the CM-IDLE state. It will also be assumed that at <NUM> the subject RSC UT <NUM> has determined that its movement exceeded a threshold distance and, in response, the RSC UT <NUM> sends the SB paging SRAN <NUM> a location report <NUM>. The location report <NUM> can include the S-TMSI assigned to the subject RSC UT <NUM>, and can include an updated UT location data. The SB paging SRAN <NUM> can, in response, determine the subject RSC UT <NUM>'s current TA based, for example, on the updated UT location data, and the send the subject RSC UT <NUM> a location response <NUM>, which includes the newly determined TA. The subject RSC UT <NUM> can, upon receiving the newly determined TA, check to see if that TA is in its currently assigned RA. If the answer is affirmative the flow <NUM> can return to <NUM> and continue until, for example, a next instance of above-threshold movement by the subject RSC UT <NUM>.

Assuming the subject RSC UT <NUM> finds the newly determined TA is not in its currently assigned RA, the RSC UT <NUM> can send a REG RQST <NUM> to the SB paging SRAN <NUM>. The REG RQST <NUM> can be configured, for example, as a mobility registration updating under 3GPP TS <NUM>, version <NUM>. <NUM>, Release <NUM>. The SB paging SRAN <NUM>, in response to REG RQST <NUM>, can perform a forwarding <NUM> of the REG RQST <NUM>, with the newly determined TA, to the AMF <NUM>. The AMF <NUM>, upon receiving the forwarding <NUM> of the REG RQST <NUM>, with the newly determined TA, can initiate additional mobility registration updating operations <NUM>. The AMF <NUM> can then proceed from <NUM> to <NUM>, where operations can include sending a mobility registration update accept <NUM> back to the SB paging SRAN <NUM> for delivery to the RSC UT <NUM>. The SB paging SRAN <NUM>, in response, can perform a forwarding <NUM> of the mobility registration update accept <NUM>.

<FIG> is a flow diagram illustrating a flow <NUM> of operations in alternative UT initial registration portions, for operations in UT registration tracking, resource conserving paging, and data delivery for satellite-based <NUM> systems and methods in accordance with this disclosure. The <FIG> example flow <NUM> can be implemented and will be described as an extension of the above-described <FIG> flow <NUM>. Operations <NUM>-<NUM> of the flow <NUM> can be identical to such operations in the context of the <NUM>. Therefore, <FIG> is self-descriptive and additional description is not necessary.

When there is downlink data for a subject RSC UT <NUM> in CM-IDLE state, the AMF <NUM> can send to the SB paging SRAN <NUM> a Paging signal. The Paging signal can include the S-TMSI and the current RA of the subject UT <NUM> RA. Based on an SB paging SRAN <NUM> stored mapping of TA to satellite beam, the SB paging SRAN <NUM> can send the paging signal to a beam that covers the subject RSC UT <NUM>'s current TA. This can provide substantial savings of satellite system resources, i.e., bandwidth and power, compared to the conventional satellite <NUM> paging of the entire registration area of the RSC UT <NUM>.

For a UT in CM-CONNECTED/RRC-INACTIVE state, the paging can be originated by the SB paging SRAN <NUM>, instead of the SRAN receiving and forwarding a paging from the AMF <NUM>. A reason is that, from the AMF <NUM> vantage point, a subject RSC UT <NUM> in the CM-CONNECTED/RRC-INACTIVE state appears to be in the CM-CONNECTED state, and AMF <NUM> sending data to a CM-CONNECTED UT does not require a preceding page of the UT. Referring to <FIG>, specific operations can include the AMF <NUM> handling the control plane and the UPF <NUM> handling the user plane, and when data for a subject RSC <NUM> arrives at the UPF <NUM> the UPF notifies the AMF <NUM> about the data. Since the UT in the CM-CONNECTED/RRC-INACTIVE state appears to be in the CM-CONNECTED state, the AMF <NUM> response includes notifying the UPF <NUM> to proceed with sending the data to the subject RSC UT <NUM> via the SB paging SRAN <NUM>. This distinguishes from AMF <NUM> - UPF <NUM> communication and operations when data for a subject RSC <NUM> arrives at the UPF <NUM> while the subject RSC UT is in the CM-IDLE state. Such communication and operation includes the AMF <NUM> notifying the UPF <NUM> to hold the data while the AMF <NUM> is paging the subject RSC UT <NUM>.

<FIG> is a sequence diagram <NUM> of operations of UT registration, followed by switching to RRC-INACTIVE State, and proceeding to direct-to-SRAN paging, for satellite-based <NUM> systems and methods for satellite resource conserving <NUM> UT paging in accordance with this disclosure.

The <FIG> example sequence <NUM> can be implemented and will be described as an extension of the above-described <FIG> flow <NUM>. In an instance of the sequence <NUM>, operations <NUM>-<NUM> will be assumed to have been performed, and that at "T2" the subject RSC UT <NUM> is in the CM-CONNECTED state. It will be assumed that at <NUM> the subject UT <NUM> switches to the RRC-INACTIVE state, for example, based on an inactivity and that, at <NUM>, other CN elements have data for delivery to the subject RSC UT <NUM>. The sequence <NUM> can then proceed to <NUM> to transfer the data to the subject RSC UT <NUM>. Operations at <NUM> are in accordance with the subject RSC UT <NUM> in the RRC-INACTIVE state being seen as CM-CONNECTED by the AMF <NUM>. Accordingly, with the AMF <NUM> handling the control plane and the UPF <NUM> handling the user plane, the AMF <NUM> notifies the UPF <NUM> to proceed with sending the data to the subject RSC UT <NUM> via the SB paging SRAN <NUM>. The SB paging SRAN <NUM>, in response, can determine at <NUM> the best beam for paging the subject RSC UT <NUM>. The determination at <NUM> can be identical to the above-described determination at <NUM> of sequences <NUM>, <NUM>, <NUM>, and <NUM>. The SB paging SRAN <NUM>, after the determination at <NUM>, can send a page command <NUM> to the GEO satellite <NUM>. Assuming the page signal reaches the RSC UT <NUM>, the RSC <NUM> UT can send a page response <NUM>, whereupon the SB paging SRAN <NUM> can send downlink data <NUM>.

<FIG> is a sequence diagram illustrating alternative UT initial registration portions, in a sequence <NUM> of operations in UT registration, switch to RRC-INACTIVE State, and direct to SRAN paging, for satellite-based <NUM> systems and methods for satellite resource conserving <NUM> paging. The <FIG> example sequence <NUM> can be implemented and will be described as an extension of the above-described <FIG> sequence <NUM>. Operations <NUM>-<NUM> of the sequence <NUM> can be identical such operations in the context of the sequence <NUM>. Therefore, <FIG> is self-descriptive and additional description is not necessary.

In the above-described flow <NUM>, and sequences <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, the SB SRAN <NUM> maintained a record of the subject RSC UT <NUM> current TA. In another implementation, a record of each RSC UT <NUM> current TA can be maintained by a modification of the AMF <NUM>, which for purposes of convenience can be referred to as a "TA-Level UT Paging AMF.

<FIG> is a block diagram for a system <NUM> for TA-Level AMF paging control for satellite-based <NUM> systems and methods for satellite resource conserving <NUM> paging. The <FIG> example implementation is described as a modification of system <NUM>. The system <NUM> can include, for example, in place of the system <NUM> AMF <NUM>, a TA-Level UT Paging AMF <NUM> and can include, for example, in place of the system <NUM> SB paging SRAN <NUM>, a modified SB paging SRAN <NUM>. The TA-Level UT Paging AMF <NUM> can be configured to include standard <NUM>-defined AMF features and functionalities, and to include an AMF S-TMSI-to-TA mapping logic <NUM>, and an AMF-based TA-inserted paging logic <NUM>. The AMF S-TMSI-to-TA mapping logic <NUM> and AMF-based TA-inserted paging logic <NUM> can be respectively implemented, for example and without limitation, as processor-executable instructions, e.g., logic table creation instructions and modified <NUM> paging instructions, stored in an instruction memory resource (not explicitly visible in <FIG>) of a COTS-implemented <NUM> AMF. The instruction memory resource can be coupled to the COTS processor resource (not explicitly visible in <FIG>) of the COTS-implemented <NUM> AMF. An example paging process by the system <NUM> can be in accordance with the following modification of <FIG> flow <NUM>: block <NUM> can be modified to carry the TA determined at <NUM>; block <NUM> can be modified such that the SB SRAN <NUM> receives the subject RSC UT <NUM> TA in the page command, and block <NUM> can be modified such that the SB SRAN <NUM> determines the best beam based at least in part on the RSC UT <NUM>'s TA received at <NUM>, as opposed to the SB SRAN <NUM>'s stored TA for the UT <NUM>.

<FIG> is a flow diagram of a flow <NUM> for operation in a process of TA-Level AMF paging control, for satellite-based <NUM> systems and methods for satellite resource conserving, beam-selective <NUM> paging in accordance with this disclosure. An example instance of the flow <NUM> will be described in reference to <FIG> and <FIG>. In the example instance, operations can proceed from a start <NUM> to <NUM> upon a UT, such as the <FIG> RSC UT <NUM>-<NUM> (appearing as sending a REG RQST to the modified SB paging SRAN <NUM> (appearing as "MSBP SRAN" in <FIG>) having jurisdiction over the RSC UT <NUM>'s current cell. It will be assumed, for this example instance, that the modified SB paging SRAN <NUM> and the TA-Level UT Paging AMF <NUM> have jurisdiction over the RSC UT <NUM>'s current cell. Upon the modified SB paging SRAN <NUM> receiving the REG RQST that the RSC UT <NUM> sent at <NUM>, the flow <NUM> can proceed to <NUM>, where operations of the modified SB paging SRAN <NUM> can determine the subject UT <NUM>'s current TA, append the determined TA to the REG RQST, and forward the REG RQST with the TA to the TA-Level UT Paging AMF <NUM>. In one or more implementations of TA-Level AMF paging control in accordance with this disclosure, the modified SB paging SRAN <NUM> may be configured to not store the TA determined at <NUM> or any association between the TA and the subject RSC UT <NUM>. This can reduce processing load and memory requirements of the modified SB paging SRAN <NUM>.

After the modified SB paging SRAN <NUM> forwards the REG RQST with appended TA to the TA-Level UT Paging AMF <NUM>, the flow <NUM> can proceed from <NUM> to <NUM>, where the TA-Level UT Paging AMF <NUM>, in response, can generate and send to the modified SB paging SRAN <NUM> a REG accept having the S-TMSI and the RA assigned to the subject RSC UT <NUM>. According to an aspect of TA-Level AMF paging control in accordance with this disclosure, the TA-Level UT Paging AMF <NUM> can be configured to store, e.g., in association with the subject RSC UT <NUM>-TMSI, the TA that block <NUM> received with the REG RQST. The flow <NUM> can proceed from <NUM> to <NUM> where the modified SB paging SRAN <NUM> can forward the registration accept to the subject RSC UT <NUM>.

At <NUM>, sometime after the subject RSC UT <NUM> receives the registration accept forwarded at <NUM>, and otherwise completes the registration process (not fully visible in <FIG>), the subject RSC UT <NUM> can switch to the CM-IDLE state. The switch at <NUM> can be associated, for example, with standard <NUM> UT inactivity-based state switching. While in the CM-IDLE state the subject RSC UT <NUM> can, for example as a background process, apply operations at <NUM> to determine if the UT has moved more than a threshold distance from its previous location, e.g., such as described in reference to sequence <NUM>, <NUM>-<NUM>. The flow <NUM> can also include reception operations <NUM>, at the TA-Level UT Paging AMF <NUM>, of a CN-core generated Namf_Comm_N1N2MessageTransfer associated, for example, with the CN having data for delivery to the subject RSC UT <NUM>. The operations at <NUM> can be configured, for example, as an interrupt-type service. It will be understood that the relative placements and arrangement of the <FIG> blocks <NUM> and <NUM> are arbitrary and are not intended to define or to imply any requisite timing, or any sequencing or dependency of operations implementing the blocks. Also, it will be understood that reception at <NUM> is not necessarily conditioned on first applying operations at <NUM>.

For purposes of description it will be assumed that a Namf_Comm_N1N2MessageTransfer, invoking operations at <NUM>, occurs prior to a first instance of a detection at <NUM> of an above-threshold movement of the UT <NUM>. Operations at <NUM> can include reading or extracting the UT identifier from the Namf_Comm_N1N2MessageTransfer, whereupon the flow <NUM> can proceed to <NUM>, where operations of the TA-Level UT Paging AMF <NUM> can determine the S-TMSI of the subject UT <NUM>, for example, if the S-TMSI is not contained by the Namf_Comm_N1N2MessageTransfer. Operations at <NUM> can then retrieve the UT <NUM>'s TA, using the determined S-TMSI and the UT S-TMSI to current TA mapping <NUM>. It will be understood that "determined S-TMSI," in the above-described context of determining the S-TMSI of the RSC UT <NUM> relating to the Namf_Comm_N1N2MessageTransferTA, can encompasses a two-layer mapping of UT S-TMSI to current TA, which can effect a direct mapping, from the form or protocol by which the Namf_Comm_N1N2MessageTransfer identifies the UT <NUM>, to the UT <NUM>'s current TA stored at time of registration.

Upon operations at <NUM>, e.g., by the TA-Level UT Paging AMF <NUM>, of obtaining the UT <NUM>'s current TA, remaining operations at <NUM> can complete the page command, in a configuration that carries the current TA of the UT <NUM> retrieved or looked up at <NUM> and can send the page command to the modified SB paging RAN <NUM>. Upon the modified SB paging SRAN <NUM> receiving the page command, the flow <NUM> can proceed to <NUM> where operations of the modified SB paging SRAN <NUM> can include determining or selecting a best beam for paging the subject UT <NUM>. When the determining or selecting operations at <NUM> are completed, the modified SB paging SRAN <NUM> can send the appropriate page command to the GEO satellite <NUM>. Operations at <NUM> of determining or selecting a best beam can be implemented, for example, by a TA-to-beam map or table (not separately visible in the figures).

In the above-described operations, the phrase "current TA of the RSC UT <NUM>" is applied to the current TA obtained from the mapping stored at <NUM>. In the described example the Namf_Comm_N1N2MessageTransfer was received prior to a detection at <NUM> of the RSC UT having moved beyond the threshold distance. In an illustrative continuation of the example above, after the described paging and transfer of data to the RSC UT <NUM> (not visible in <FIG>), it will be assumed that such detection at <NUM> occurs and, in response, the flow <NUM> can proceed back to <NUM>, where the subject RSC UT <NUM> can send another REG RQST to the modified SB paging SRAN <NUM>. This flow <NUM> can then repeat, basically, operations at <NUM>-<NUM>. The repeat, though, may be mobility registration updating such as described above in reference to operations <NUM>-<NUM> in sequenced <NUM> and <NUM>. In such operations, the subject UT <NUM> can be in the CM-IDLE state and, therefore, the "UT Switches to CM-IDLE" operation at <NUM> can be omitted.

For a vehicular or otherwise mobile RSC UT, the UT can update its location by sending REG RQST to the SRAN, e.g., the SB paging SRAN <NUM> or the modified SB paging SRAN <NUM> to initiate mobility registration updating such that the SRAN and the AMF have the UT's latest location or RA. A trigger for the RSC UT to send the location update can be based on the UT's travel distance. One implementation of such a trigger can be as follows: when the UT travels more than a threshold (TH) distance, e.g., TH kilometers, the RSC UT is triggered to update its location. In another implementation, a RSC UT can be configured to receive or otherwise be associated with a travel map, and to include a location update triggering configuration that can trigger the RSC UT to send updates of its location based, at least in part, on elapsed time. For example, for a RSC UT carried on an aircraft that flies according to a flight plan, the RSC UT can send the travel map, which includes the UT's projected speed, to the SRAN in advance. The SRAN can therefore estimate the RSC UT location in advance.

Example implementations according to this disclosure can be practiced in application environments that include adjacent countries covered by respectively different RAs. The assignment of respectively different RA for different countries can be needed, for example, for legal interception, billing and other purposes. Example implementations according to this disclosure can also be practiced in application environments wherein one or more countries receive more than one beam. In such a case, the country can be assigned multiple RAs, one RA for each beam.

<FIG> shows such an environment <NUM> having aspects that include a simulated or constructed hypothetical geographical area (visible but not collectively numbered) that can include a simulated or constructed hypothetical first country, labeled "Country <NUM>," and adjacent Country <NUM> a simulated or constructed hypothetical second country, labeled "Country <NUM>. " The <FIG> environment also includes one or more satellites (not explicitly visible in <FIG>), providing four beams, which are first beam <NUM>-<NUM>, second beam <NUM>-<NUM>, third beam <NUM>-<NUM>, and fourth beam <NUM>-<NUM> (collectively referenced as "beams <NUM>"). Country <NUM> is covered by two of the beams <NUM>, which are first beam <NUM>-<NUM> and second beam <NUM>-<NUM>. Country <NUM> is covered by three of the beams <NUM>, which are first beam <NUM>-<NUM>, third beam <NUM>-<NUM>, and fourth beam <NUM>-<NUM>.

In the <FIG> configuration, Country <NUM> is assigned two RAs, numbered respectively as <NUM>-<NUM> and <NUM>-<NUM> (collectively "first country RAs <NUM>"). RAs <NUM>-<NUM> and <NUM>-<NUM> will be alternatively referred to, respectively, as "first country first RA" <NUM>-<NUM>, and "first country second RA" <NUM>-<NUM>. " As seen in <FIG>, one of the first country RAs <NUM> is assigned to each of the two beams covering Country <NUM>, i.e., first country first RA <NUM>-<NUM> is assigned to the first beam <NUM>-<NUM>, and first country second RA <NUM>-<NUM> is assigned to the second beam <NUM>-<NUM>. Country <NUM> is assigned three (<NUM>) RAs, numbered respectively as <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> (collectively "second country RAs <NUM>"). RAs <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> will be alternatively referred to, respectively, as "second country first RA" <NUM>-<NUM>, "second country second RA" <NUM>-<NUM>, and second country third RA <NUM>-<NUM>. " As shown in <FIG>, one of the second country RAs <NUM> is assigned to each of the three beams covering Country <NUM>, i.e., second country first RA <NUM>-<NUM> is assigned to first beam <NUM>-<NUM>, second country second RA <NUM>-<NUM> is assigned to the third beam <NUM>-<NUM>, and second country third RA <NUM>-<NUM> is assigned to the fourth beam <NUM>-<NUM>.

A first RSC UT <NUM>-<NUM>, is shown located in the second country first RA <NUM>-<NUM>, a second RSC UT <NUM>-<NUM> is shown in second country third RA <NUM>-<NUM>, and a third RSC UT <NUM>-<NUM> is shown in first country second RA <NUM>-<NUM>. In one or more paging processes according to this disclosure, paging to the first RSC UT <NUM>-<NUM> will be sent only to the first beam <NUM>-<NUM>, since UT <NUM>-<NUM> is in the second country first RA <NUM>-<NUM> which is in beam <NUM>-<NUM>. Likewise, paging to the second RSC UT <NUM>-<NUM> will be sent only to the fourth beam <NUM>-<NUM> since the second RSC UT <NUM>-<NUM> is in the second country third RA <NUM>-<NUM> which is in the fourth beam <NUM>-<NUM>. Paging to the third RSC UT <NUM>-<NUM> will be sent only to the second beam <NUM>-<NUM> since RSC UT <NUM>-<NUM> is in second country second RA <NUM>-<NUM>, which is in the second beam <NUM>-<NUM>. In each of the above-described pagings, the paging is sent to only one beam.

In practices in accordance with this disclosure, the SB paging <NUM> will be updated, for example, by location reporting and re-registration processes provided by systems and methods described above in reference to one or more among <FIG>. Also in accordance with disclosed processes, systems, and methods, as UT <NUM>-<NUM> and UT <NUM>-<NUM> travels within Country <NUM>, each will send a registration update when it moves from one of the country's RAs to the other.

As described above, in various mobility registration updating processes in accordance with terrestrial <NUM> systems, a UT can be required to determine, with a substantial frequency of execution, whether the UT has moved out of its registration area. A similar type issue, in terrestrial <NUM> systems, is that UTs can be required to transmit location reports or updates to the system RAN.

<FIG> is a flow diagram of a flow <NUM> in a process for reduced UT and system overhead UT location reporting, for satellite-based <NUM> systems and methods for satellite resource conserving <NUM> paging in accordance with this disclosure. Example operations in an instance of the flow <NUM> will be described in reference to the <FIG> system <NUM>. This is only for purposes of example and is not intended as a limitation regarding implementations and practices in accordance with this disclosure. For example, and without limitation, the operations described in reference to <FIG> can be adapted to the <FIG> system <NUM>.

In an example instance of the flow <NUM>, operations can begin with a RSC UT, such as any of the system <NUM> RSC UTs <NUM>, proceeding from a start <NUM> to <NUM> where RSC UT operations can send, for example, a REG RQST to an available SB paging SRAN (appearing as "MSB SRAN" in <FIG>) to register, for example, with the AMF having jurisdiction over the RSC UT <NUM>'s current cell. It will be assumed, for purposes of the present example, that the available SB paging SRAN is the SB paging SRAN <NUM> and the AMF having jurisdiction over RSC UT <NUM>'s current cell, is the AMF <NUM>. Upon the SB paging SRAN <NUM> receiving the REG RQST the RSC UT <NUM> sent at <NUM>, the flow <NUM> can proceed to <NUM>, where operations of the SB paging SRAN <NUM> can determine the subject RCS UT <NUM>'s current TA, append the determined TA to the REG RQST, and forward the REG RQST with TA to the AMF <NUM>. The flow <NUM> can then proceed from <NUM> to <NUM>, where the AMF <NUM> can generate an S-TMSI and RA for the subject RSC UT <NUM>, and send to the SB paging SRAN <NUM> a registration accept having the S-TMSI and RA.

Upon the SB paging SRAN <NUM> receiving the registration accept sent at <NUM>, the flow <NUM> can proceed to <NUM>, where the SB paging SRAN <NUM> can generate a UT-specific movement threshold UTS-TH and can send the registration accept, with UTS-TH, to the subject RSC UT <NUM>. The UTS-TH value can be, for example, in terms of kilometers, miles, or any other distance metric. The distance metric can be absolute e.g., kilometers or miles, or can be a value normalized to another spacing. The UTS-TH value can be independent of direction, i.e., can define a circular perimeter. In an aspect, UTH-TH value may define a perimeter having non-uniform distance from a center reference. The subject RSC UT <NUM> can store the UTS-TH value in its UT location detection/ reporting logic <NUM>.

In an aspect, operations at <NUM> can include or can effect completion of initial registration of the subject RSC UT <NUM>, whereupon the subject RSC UT <NUM> can be placed, for example, in the CM-CONNECTED state. Subsequent to the initial registration the now-registered subject RSC UT <NUM> can switch, as shown by operations <NUM>, from the CM-CONNECTED state to the CM-IDLE state, for example, due to inactivity of the RSC UT <NUM>. The RSC UTs <NUM> can be configured such that each of the UT, after switching to the CM-IDLE state, can periodically apply RSC operations at <NUM> that, based at least in part on UT receipt of SIBs carrying TA vertices, can determine present RSC UT distance or position, e.g., relative to the position at initial registration. From <NUM> the flow <NUM> can proceed to <NUM> where the RSC UT location detection/ reporting logic <NUM> of the RSC UT <NUM> can compare the distance or position determined at <NUM> to the UTS-TH value. It will be understood that the meaning of "compared," in this context, does not necessarily require direct comparison of the determination at <NUM> to the UTS-TH value. For example, operations at <NUM> can be implemented using a measurement or extraction of a parameter value indicative of a relation between a determination at <NUM> and the UTS-TH value, or using a scalar that can be computed based, in whole or on a determination at <NUM>. It will also be understood that operations at <NUM> can be configured as estimation or classifier operations. For example, operations at <NUM> can be configured as a binary classifier, between, e.g., "distance exceeded" and "distance not exceeded.

The flow <NUM> can be configured such only upon a "Yes" determination at <NUM> will the flow <NUM> proceed to <NUM> for the RSC UT <NUM> to determine if it has moved to a different changed TA. In such a configuration, if the determination at <NUM> is "No," the flow <NUM> can return to <NUM>. The return to <NUM> can be direct or, for example, can be performed in accordance with a scheduling condition. Technical benefits of conditioning the RSC UT <NUM>'s determination of whether it has moved to a different TA on a distance threshold, as opposed to the RSC UT <NUM> applying periodic automatic determination, can include conservation of UT <NUM> processing resources, and conservation of UT <NUM> battery power.

In instances where the determination at <NUM> is "Yes," the flow <NUM> can proceed to <NUM>, where operations can determine if the subject RSC UT <NUM>'s TA has changed. If the determination at <NUM> is that the TA has not changed the flow <NUM> can return, as shown by the "No" outbranch of flow decision block <NUM>, back to <NUM>. If the determination at <NUM> is that the TA has changed, flow <NUM> can proceed, as shown by the "Yes" outbranch of flow decision block <NUM>, back to <NUM> to re-register.

<FIG> is a block diagram showing an example a computer system <NUM> upon which aspects of this disclosure may be implemented. It will be understood that functional blocks illustrated in <FIG> are logical blocks, and do not necessarily correspond to particular hardware.

The computer system <NUM> may include a bus <NUM> or other communication mechanism for communicating information, and a processor <NUM> coupled with the bus <NUM> for processing information. The computer system <NUM> may also include a main memory <NUM>, such as a random-access memory (RAM) or other dynamic storage device, coupled to the bus <NUM> for storing information and executable instructions to be executed by the processor <NUM>. The executable instructions can include instruction that, when executed by the processor <NUM>, cause the processor to perform operations in accordance with the flow diagrams of <FIG>, <FIG>, and <FIG> sequence diagrams of <FIG>, and <FIG>. The main memory <NUM> may also be used for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor <NUM>. The computer system <NUM> may implement, for example, UT, SRAN, AMF, UPF.

The computer system <NUM> may further include a read only memory (ROM) <NUM> or other static storage device coupled to the bus <NUM> for storing static information and instructions for the processor <NUM>. A storage device <NUM>, such as a flash or other non-volatile memory may be coupled to the bus <NUM> for storing information and instructions.

The computer system <NUM> may be coupled via the bus <NUM> to a display <NUM>, such as a liquid crystal display (LCD), for displaying information. One or more user input devices, such as the example user input device <NUM> may be coupled to the bus <NUM>, and may be configured for receiving various user inputs, such as user command selections and communicating these to the processor <NUM>, or to the main memory <NUM>. The user input device <NUM> may include physical structure, or virtual implementation, or both, providing user input modes or options, for controlling, for example, a cursor, visible to a user through display <NUM> or through other techniques, and such modes or operations may include, for example virtual mouse, trackball, or cursor direction keys.

The computer system <NUM> may include respective resources of the processor <NUM> executing, in an overlapping or interleaved manner, respective program instructions. Instructions may be read into the main memory <NUM> from another machine-readable medium, such as the storage device <NUM>. In some examples, hard-wired circuitry may be used in place of or in combination with software instructions. The term "machine-readable medium" as used herein refers to any medium that participates in providing data that causes a machine to operate in a specific fashion. Such a medium may take forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media may include, for example, optical or magnetic disks, such as storage device <NUM>. Transmission media may include optical paths, or electrical or acoustic signal propagation paths, and may include acoustic or light waves, such as those generated during radio-wave and infra-red data communications, that are capable of carrying instructions detectable by a physical mechanism for input to a machine.

The computer system <NUM> may also include a communication interface <NUM> coupled to the bus <NUM>, for two-way data communication coupling to a network link <NUM> connected to a local network <NUM>. The network link <NUM> may provide data communication through one or more networks to other data devices. For example, the network link <NUM> may provide a connection through the local network <NUM> to a host computer <NUM> or to data equipment operated by an Internet Service Provider (ISP) <NUM> to access through the Internet <NUM> a server <NUM>, for example, to obtain code for an application program.

While various embodiments have been described, the description is intended to be exemplary, rather than limiting, and it is understood that many more embodiments and implementations are possible that are within the scope of the embodiments. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any embodiment may be used in combination with or substituted for any other feature or element in any other embodiment unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the embodiments are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.

While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections <NUM>, <NUM>, or <NUM> of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.

Claim 1:
A satellite radio access network, SRAN (<NUM>,<NUM>,<NUM>), comprising:
a processor; and
a memory communicatively connected to the processor and storing executable instructions that, when executed by the processor, cause the processor to:
receive (<NUM>), via a GEO satellite (<NUM>), a registration request from a user terminal, UT (<NUM>), and in response:
determine (<NUM>) a current tracking area, TA, in which the UT (<NUM>) is located, based at least in part on a content of the registration request, and
send (<NUM>) the registration request and an identification of the current TA to an access and mobility management function, AMF (<NUM>,<NUM>);
receive (<NUM>) a registration accept from the AMF (<NUM>,<NUM>) and, in response, forward (<NUM>) the registration accept to the UT (<NUM>), the registration accept indicating a registration area for the UT; and
receive (<NUM>) from the AMF (<NUM>,<NUM>) a UT page command that identifies the UT (<NUM>) and, in response:
determine (<NUM>) a satellite beam for paging the UT (<NUM>), from among a plurality of satellite beams, based at least in part on the identifier of the current TA, and
page (<NUM>) the UT on said satellite beam for paging the UT (<NUM>);
and wherein the executable instructions further include instructions that, when executed by the processor, cause the processor to:
store a mapping of TAs to satellite beams, and
wherein:
the UT page command includes the identification of the current TA, and determining the satellite beam for paging the UT (<NUM>) includes:
extracting the identification of the current TA from the UT page command, and
applying the extracted identification of the current TA to the mapping of TAs to satellite beams.