DESC:RESERVATION OF RIGHTS
[001] A portion of the disclosure of this patent document contains material which is subject to intellectual property rights such as, but are not limited to, copyright, design, trademark, integrated circuit (IC) layout design, and/or trade dress protection, belonging to Jio Platforms Limited (JPL) or its affiliates (herein after referred as owner). The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all rights whatsoever. All rights to such intellectual property are fully reserved by the owner.

TECHNICAL FIELD
[002] The present disclosure relates to a field of satellite-based communication system, and specifically to a system and a method for enabling delay-tolerant services in a satellite-based communication system.

BACKGROUND
[003] The following description of related art is intended to provide background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section be used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of prior art.
[004] A Non-Terrestrial Network (NTN) in a 3rd Generation Partnership Project (3gpp) provides a non-terrestrial New Radio (NR) access to a User Equipment (UE) by an NTN payload and an NTN gateway, with a service link between the NTN payload and the UE, and a feeder link between the NTN gateway and the NTN payload, as illustrated in FIG. 1.
[005] The NTN payload may transparently forward a radio protocol received from the UE (via the service link) to the NTN gateway (via the feeder link) and vice-versa. The following connectivity may be supported by the NTN payload:
- The NTN gateway may serve multiple NTN payloads, and
- The NTN payload may be served by multiple NTN gateways.
[006] The following three types of the service links may be supported:
- Earth-fixed: provisioned by beam(s) continuously covering the same geographical areas all the time (e.g., the case of geosynchronous orbit (GSO) satellites);
- Quasi-earth-fixed: provisioned by beam(s) covering one geographic area for a limited period and a different geographic area during another period (e.g., the case of Non-GSO (NGSO) satellites generating steerable beams);
- Earth-moving: provisioned by beam(s) whose coverage area slides over an Earth surface (e.g., the case of NGSO satellites generating fixed or non-steerable beams).
[007] With the NGSO satellites, a base station (e.g., a gNodeB (gNB)) may provide either the quasi-earth-fixed service link or the earth-moving service link, while the gNB operating with the GSO satellite provides the earth-fixed service link.
[008] The NGSO satellites, when not deployed properly, like a sufficient number of satellites in constellations and a sufficient number of NTN gateways in appropriate locations, there is a high chance that the satellites lose feeder links and eventually lose connectivity with a core network. During this situation, the satellite may provide coverage on earth without the core network. This mode of operation may be loosely termed as a coreless satellite access mode or operation. To effectively utilize the already deployed infrastructure during such situations until the feeder link is restored, there is a need for a store and forward mechanism for some of the delay tolerant or non-real-time services.
[009] There is, therefore, a need in the art to provide an improved system and a method to enable delay-tolerant services in a satellite-based communication system by overcoming the deficiencies of the prior art(s).
OBJECTS OF THE PRESENT DISCLOSURE
[0010] It is an object of the present disclosure to provide a system and a method for supporting delay tolerance in satellite radio access functionality.
[0011] It is an object of the present disclosure to enable delay-tolerant services including efficient store and forward mechanisms in a satellite system, where the satellite system provides some level of services even when the satellite system loses a feeder link connectivity with a ground station, which is connected to a core network and supported application servers.
[0012] It is an object of the present disclosure to continuously monitor availability of neighboring satellites on a same orbital plane, in a set range.
[0013] It is an object of the present disclosure to detect incoming and outgoing satellites within the neighboring parallel orbital planes, within the set range.
[0014] It is an object of the present disclosure to detect incoming and outgoing satellites within the neighboring perpendicular or heliptical orbital planes, within the set vicinity of interest.
[0015] It is an object of the present disclosure to establish an inter-satellite link with new satellites.
[0016] It is an object of the present disclosure to choose, for any satellite in a network, an exact satellite with an active feeder link for data transfer with least delay and least number of Inter-Satellite Link (ISL) hops.
[0017] It is an object of the present disclosure to apply Store and Forward (S&F) mechanism for all delay tolerant or non-real time services, whenever a serving satellite does not have either direct or indirect feeder link with a ground station, and the serving satellite with a base station payload or a bent pipe payload does not have the feeder link with the ground station in any form.
[0018] It is an object of the present disclosure to enable the satellite in a coreless radio access mode to locally authenticate new User Equipments (UEs) and allow the delay tolerant or non-real-time services for that UE, and once the feeder link is restored, actual authentication with the core network may be initiated.
SUMMARY
[0019] This section is provided to introduce certain objects and aspects of the present disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
[0020] In an aspect, the present disclosure relates to a system for enabling store and forward mechanism in delay-tolerant services of a serving satellite. The system includes one or more processors and a memory operatively coupled to the one or more processors. The memory includes processor-executable instructions, which on execution, cause the one or more processors to receive data from at least one User Equipment (UE), where the at least one UE is available within a predefined range of the serving satellite. The one or more processors detect an availability or unavailability of a feeder link between the serving satellite and an entity upon receiving the data. Based on the detection that the feeder link is unavailable, the one or more processors enable a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored. Upon enabling the store and forward mechanism, the one or more processors continuously monitor and detect one or more neighbouring satellites in proximity to the serving satellite within the predefined range.
[0021] Further, the one or more processors update an Automatic Satellite Neighbour Relations (ASNR) table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites. The one or more processors establish an inter-satellite link (ISL) with the new neighbouring satellite, and broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites. The one or more processors, upon updating the ASNR table and restoration of the feeder link, forward the stored data to at least one of the one or more neighbouring satellites via the ISL.
[0022] In an embodiment, the processor may be configured to continuously monitor and detect the one or more neighbouring satellites in at least one of same orbital plane, neighboring parallel orbital planes, and neighboring perpendicular or heliptical orbital planes.
[0023] In an embodiment, the processor may be configured to establish the ISL with the new neighbouring satellite by sending a ISL setup request message to the new neighbouring satellite, where the ISL setup request message may include information related to the serving satellite as details of one or more source satellites and an ASNR table list of the one or more source satellites. Based on a successful authentication, the processor may be configured to receive a ISL setup response message from the new neighbouring satellite, where the ISL setup response message may include the details of the one or more source satellites, details of the new neighbouring satellite as details of a target satellite, and the ASNR table list of both the one or more source satellites and the target satellite. Upon receiving the ISL setup response message, the processor may be configured to update the ASNR table list of the one or more source satellites with the received ASNR table list of the target satellite, and establish the ISL with the new neighbouring satellite upon updating the ASNR table list of the one or more source satellites.
[0024] In an embodiment, upon updating the ASNR table list of the one or more source satellites, the processor may be configured to send an ISL setup update message to all the one or more neighbouring satellites, where the ISL setup update message may include the updated ASNR table list of the one or more source satellites. The one or more neighbouring satellites may update the ASNR table list with the received updated ASNR table list of the one or more source satellites to enable the one or more neighbouring satellites to initiate ISL establishment with the new neighbouring satellite.
[0025] In an embodiment, the ISL setup request message may include authentication credentials to verify, by the new neighbouring satellite, a legitimacy of the serving satellite before establishing the ISL with the new neighbouring satellite.
[0026] In an embodiment, the processor may be configured to set an ISL link status flag in the serving satellite to enable or disable based on an availability of the ISL.
[0027] In an embodiment, the processor may be configured to set the ISL link status flag to enable upon successful establishment of the ISL with the one or more neighbouring satellites. The processor may be configured to initiate an out-of-synchronization timer and attempt to re-establish synchronization, within a predefined time window, with the one or more neighbouring satellites, based on a detection of an out-of-synchronization condition on the established ISL. The processor may be configured to resume normal operation to forward the stored data to the at least one of the one or more neighbouring satellites, and retain the enable status for the ISL link status flag if the synchronization is restored before an expiry of the out-of-synchronization timer, or set the ISL link status flag to disable for at least one affected neighbouring satellite entry in the ASNR table if the synchronization is not restored upon expiry of the out-of-synchronization timer. The processor may be configured to transmit an ISL capability update message including updated ISL link status flag and the ASNR table to all the one or more neighbouring satellites. Upon receiving the ISL capability update message, the one or more neighbouring satellites may update the ASNR table accordingly and dynamically adjust data routing paths to avoid relying on the affected neighbouring satellite for data transfer.
[0028] In an embodiment, the processor may be configured to set a FL link status flag in the serving satellite to enable or disable based on the availability and establishment of the feeder link with the entity.
[0029] In an embodiment, the processor may be configured to set the FL link status flag to enable, upon successful establishment of the feeder link with the entity. Based on a detection of an out-of-synchronization condition on the feeder link, the processor may be configured to initiate an out-of-synchronization timer and continuously attempt to re-establish synchronization, within a predefined time period, with the entity. The processor may be configured to resume normal operation to forward the stored data to the entity, and retain the enable status for the feeder link if the synchronization is restored before an expiry of the out-of-synchronization timer. The processor may be configured to set the FL link status flag to disable for at least one affected neighbouring satellite entry in the ASNR table if the synchronization is not restored upon expiry of the out-of-synchronization timer. Further, the processor may be configured to transmit an ISL capability update message including updated FL link status flag and the ASNR table to all the one or more neighbouring satellites. Upon receiving the ISL capability update message, the one or more neighbouring satellites may update the ASNR table accordingly and dynamically adjust data routing paths to avoid relying on the affected neighbouring satellite for data transfer toward the entity.
[0030] In an embodiment, the processor may be configured to transmit a FL link status to all one or more connected neighbouring satellites using an FL configuration update message. Upon successful establishment of the feeder link with the entity, the processor may be configured to set the FL link status to enable at both the serving satellite and the entity, where the entity maintains updated ASNR tables of all the one or more connected neighbouring satellites via the feeder link. If the entity experiences an out-of-synchronization condition with the serving satellite, the processor may be configured to initiate an out-of-synchronization timer and continuously attempt to re-establish synchronization, within a predefined time period, with the entity. Further, if synchronization is achieved before an expiry of the out-of-synchronization timer, the processor may be configured to resume normal operation to forward the stored data to the entity. Upon expiry of the out-of-synchronization, the processor may be configured to set the FL link status to disable for corresponding satellite entry in the ASNR table of the entity. The entity may transmit the FL configuration update message to all the one or more connected satellites, prompting the one or more connected satellites to update the ASNR tables and exclude the affected satellite from data transmission paths toward the entity.
[0031] In an embodiment, the processor may be configured to continuously monitor and detect a status of the feeder link. Based on the detection of an active direct feeder link with the entity, the processor may be configured to bypass the store and forward mechanism and immediately forward the received data toward the entity. Based on the detection of disruption of the feeder link, the processor may be configured to dynamically enable to the store and forward mechanism to ensure uninterrupted data transmission.
[0032] In an embodiment, the processor may be configured to detect an availability of an indirect feeder link with the entity via the ISL. Based on a detection of an active ISL with at least one neighbouring satellite that has a direct feeder link to the entity, the processor may be configured to immediately forward the received data to the entity via the ISL without storing the received data. Based on a detection of a disruption of the ISL, the processor may be configured to dynamically switch to the store and forward mechanism to ensure uninterrupted data transmission to the entity.
[0033] In an embodiment, the processor may be configured to identify the unavailability of the feeder link with the entity. Based on the identification, the processor may be configured to store the received data locally in the memory until the feeder link is established. The processor may be configured to continuously monitor the availability of a direct or indirect feeder link with the entity. Upon establishing the active feeder link, either directly or indirectly via the ISL, the processor may be configured to immediately forward the stored data towards the entity.
[0034] In an embodiment, the processor may be configured to dynamically manage a storage capacity of the memory by prioritizing the received data based on predefined criteria.
[0035] In an embodiment, the processor may be configured to apply the store and forward mechanism for all delay-tolerant or non-real-time services when the serving satellite with a payload does not have the feeder link with the entity.
[0036] In an embodiment, the processor may be configured to broadcast one or more capability parameters to the at least one UE to enable the at least one UE to determine a time to transmit the data. The one or more capability parameters may include the store and forward mechanism, the feeder link availability status, and the ISL availability status.
[0037] In an embodiment, the processor may be configured to locally authenticate the at least one UE and facilitate the delay-tolerant or non-real-time services while operating in a coreless radio access mode.
[0038] In an embodiment, the processor may be configured to enable a Satellite Radio Access Network (RAN) entity to manage UE data transmission based on the availability of the feeder link.
[0039] In an embodiment, the entity may be at least one of a ground station and a Non-Terrestrial Network (NTN) Gateway (GW).
[0040] In an aspect, the present disclosure relates to a method for enabling a store and forward mechanism in delay-tolerant services of a serving satellite. The method includes receiving data from at least one UE, where the at least one UE is available within a predefined range of the serving satellite. The method includes detecting an availability or unavailability of a feeder link between the serving satellite and an entity upon receiving the data. Based on the detection that the feeder link is unavailable, the method includes enabling a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored. Upon enabling the store and forward mechanism, the method includes continuously monitoring and detecting one or more neighbouring satellites in proximity to the serving satellite within the predefined range.
[0041] Further, the method includes updating an ASNR table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites. The method includes establishing an ISL with the new neighbouring satellite, and broadcasting an availability of the ISL to the one or more neighbouring satellites and updating the ASNR table of the one or more neighbouring satellites. Upon updating the ASNR table and restoration of the feeder link, the method includes forwarding the stored data to at least one of the one or more neighbouring satellites via the ISL.
[0042] In an aspect, the present disclosure relates to a UE including a processor and a memory operatively coupled to the processor. The memory includes processor-executable instructions, which on execution, cause the processor to transmit data to a system. The processor is communicatively coupled with the system, and the system is configured to receive the data from the UE, and detect an availability or unavailability of a feeder link between the serving satellite and an entity. Based on the detection that the feeder link is unavailable, the system is configured to enable a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored. Upon enabling the store and forward mechanism, the system is configured to continuously monitor and detect one or more neighbouring satellites in proximity to the serving satellite within the predefined range.
[0043] Further, the system is configured to update an ASNR table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites. The system is configured to establish an ISL with the new neighbouring satellite, and broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites. Upon updating the ASNR table and restoration of the feeder link, the system is configured to forward the stored data to at least one of the one or more neighbouring satellites via the ISL.
[0044] In an embodiment, prior to transmitting the data to the system, the processor is configured to establish a connection with the system, receive one or more capability parameters from the system, and determine a time to transmit the data to the system based on the one or more capability parameters.
[0045] In an embodiment, the one or more capability parameters may include a store and forward mechanism, feeder link availability status, and ISL availability status.
[0046] In an embodiment, upon receiving the one or more capability parameters from the system, the processor may be configured to determine an availability or unavailability of the feeder link based on the one or more capability parameters. The processor may be configured to transmit the data immediately either directly or via a single-hop ISL based on a detection that the feeder link is available. Further, the processor may be configured to autonomously decide whether to transmit the data immediately or delay transmission by storing the data locally, based on a detection that the feeder link is unavailable or the feeder link is only accessible via a multi-hop ISL path.
[0047] In an aspect, the present disclosure relates to a non-transitory computer-readable medium comprising processor-executable instructions that cause a processor to receive data from a UE. The processor detects an availability or unavailability of a feeder link between the serving satellite and an entity. Based on the detection that the feeder link is unavailable, the processor enables a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored. Upon enabling the store and forward mechanism, the processor continuously monitors and detects one or more neighbouring satellites in proximity to the serving satellite within the predefined range. The processor updates an ASNR table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites. The processor establishes an ISL with the new neighbouring satellite, and broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites. Upon updating the ASNR table and restoration of the feeder link, the processor forwards the stored data to at least one of the one or more neighbouring satellites via the ISL.

BRIEF DESCRIPTION OF THE DRAWINGS
[0048] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
[0049] The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[0050] FIG. 1 illustrates an exemplary representation (100) for depicting an existing Non-Terrestrial Network (NTN) in a 3rd Generation Partnership Project (3gpp).
[0051] FIG. 2A illustrates an exemplary network architecture (200A) in which or with which embodiments of the present disclosure may be implemented.
[0052] FIG. 2B illustrates an example block diagram (200B) of a system for enabling a store and forward mechanism in delay-tolerant services of a serving satellite, in accordance with an embodiment of the present disclosure.
[0053] FIG. 3 illustrates an exemplary representation (300) depicting a satellite coverage area and probable neighbor satellites, in accordance with an embodiment of the present disclosure.
[0054] FIG. 4 illustrates an exemplary sequential diagram (400) for establishing an inter-satellite link with new satellites, in accordance with an embodiment of the present disclosure.
[0055] FIG. 5 illustrates an exemplary sequential diagram (500) for updating Automatic Satellite Neighbour Relations (ASNR) tables with inter-satellite link (ISL) status of satellites, in accordance with an embodiment of the present disclosure.
[0056] FIGs. 6A and 6B illustrate exemplary sequential diagrams (600A, 600B) for updating ASNR tables with a feeder link (FL) status of satellites, in accordance with an embodiment of the present disclosure.
[0057] FIG. 7 illustrates an exemplary representation (700) depicting a satellite with a direct feeder link, in accordance with an embodiment of the present disclosure.
[0058] FIG. 8 illustrates an exemplary representation (800) depicting a satellite having access to a ground station through an indirect feeder link via ISL links, in accordance with an embodiment of the present disclosure.
[0059] FIG. 9 illustrates an exemplary representation (900) depicting a satellite in a coreless mode without direct feeder link, in accordance with an embodiment of the present disclosure.
[0060] FIG. 10 illustrates an exemplary representation (1000) depicting a satellite in a coreless mode without either direct or indirect feeder link, in accordance with an embodiment of the present disclosure.
[0061] FIG. 11 illustrates an exemplary representation (1100) depicting a satellite with gNodeB-Distribution Unit (gNB-DU) payload in a coreless mode without a direct feeder link, in accordance with an embodiment of the present disclosure.
[0062] FIG. 12 illustrates an exemplary representation (1200) depicting a satellite with gNB-Radio Unit (gNB-RU) payload in a coreless mode without a direct feeder link, in accordance with an embodiment of the present disclosure.
[0063] FIG. 13 illustrates an exemplary representation (1300) depicting a satellite with a bent pipe payload in a coreless mode without a direct feeder link, in accordance with an embodiment of the present disclosure.
[0064] FIG. 14 illustrates an exemplary representation (1400) depicting a satellite broadcasting a store and forward (S&F) support and other status flags, in accordance with an embodiment of the present disclosure.
[0065] FIG. 15 illustrates an exemplary computer system (1500) in which or with which embodiments of the present disclosure may be implemented.

DETAILED DESCRIPTION
[0066] In the following description, for explanation, various specific details are outlined in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein.
[0067] The ensuing description provides exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.
[0068] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail to avoid obscuring the embodiments.
[0069] Also, it is noted that individual embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed but could have additional steps not included in a figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function.
[0070] The word “exemplary” and/or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive like the term “comprising” as an open transition word without precluding any additional or other elements.
[0071] Reference throughout this specification to “one embodiment” or “an embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0072] The terminology used herein is to describe particular embodiments only and is not intended to be limiting the disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any combinations of one or more of the associated listed items.
[0073] 5th Generation/6th Generation (5G/6G) satellite access aiming to support delay tolerant services may enable efficient mechanisms where a satellite system provides some level of services even when the satellite lose a feeder link connectivity with a ground station, which inturn may be connected to a core network and supported application servers. When a satellite transponder lose the feeder link, the satellite may operate as good as in a core less Radio Access Network (RAN) mode.
[0074] Low Earth Orbit (LEO)-based satellites are becoming more popular than other Medium Earth Orbit (MEO) and Geostationary (GEO) variants for a communication domain, due to their inherent characteristics, like the LEO satellites have circular (or elliptical) orbit at a height of 250–2000 km from an earth surface with an orbit period, ranging between 90–120 min, mainly depending on an altitude of the orbit. As the altitude of the LEO satellites is low, the velocity of the LEO satellites is very high (>25,000 km/h) and the LEO satellites make 12–16 earth turns per earth day. This means that the LEO satellite experiences at least 12 to 16 sunlight and night periods in 24 hours. Consequently, in the LEO orbit, the maximum time during which the satellite is above the local horizon for an observer on the earth is up to 20 min. This time is used to transfer data, images, and photographs to selected ground stations positioned in strategic locations. Hence, to maintain coverage continuity in a specific geography, constellation of the LEO satellites is deployed across multiple orbital planes. So, in reality, a satellite foot print or a group of spot beams coverage moves form one satellite to another satellite every 20min approximately, based on the altitude. During this satellite/coverage movement, there are high chances of losing the connectivity with the ground station more frequently or intermittently, which leaves the satellite without a core network, until the feeder link is restored, leading to coreless satellite radio access. During these periods, the LEO satellite may be able to provide delay-tolerant services or continue services without any major issues.
[0075] The present disclosure provides a system and a method to support store and forward functionality at satellite radio base stations. The system enables a store and forward mechanism in a satellite base station depending on availability or non-availability of feeder links/core network connectivity. The system enables inter-satellite link discovery for multi-hop backhaul/feeder link scenarios. The store and forward mechanism is effectively utilized for delay tolerant or non-real-time services.
[0076] The various embodiments of the present disclosure will be explained in detail with reference to FIGs. 2A to 15.
[0077] FIG. 2A illustrates an exemplary network architecture (200A) in which or with which embodiments of the present disclosure may be implemented.
[0078] Referring to FIG. 2, the network architecture (200) may include one or more user equipments (UEs) (204-1, 204-2…204-N) associated with one or more users (202-1, 202-2…202-N) in an environment. A person of ordinary skill in the art will understand that one or more users (202-1, 202-2…202-N) may be individually referred to as the user (202) and collectively referred to as the users (202). Similarly, a person of ordinary skill in the art will understand that one or more UEs (204-1, 204-2…204-N) may be individually referred to as the user equipment (204) and collectively referred to as the UE (204). A person of ordinary skill in the art will appreciate that the terms “computing device(s)” and “user equipment” may be used interchangeably throughout the disclosure. Although three UEs (204) are depicted in FIG. 2A, however any number of the UEs (204) may be included without departing from the scope of the ongoing description.
[0079] In an embodiment, the user equipment (204) may include smart devices operating in a smart environment, for example, an Internet of Things (IoT) system. In such an embodiment, the user equipment (204) may include, but is not limited to, smart phones, smart watches, smart sensors (e.g., mechanical, thermal, electrical, magnetic, etc.), networked appliances, networked peripheral devices, networked lighting system, communication devices, networked vehicle accessories, networked vehicular devices, smart accessories, tablets, smart television (TV), computers, smart security system, smart home system, other devices for monitoring or interacting with or for the users (202) and/or entities, or any combination thereof. A person of ordinary skill in the art will appreciate that the user equipment (204) may include, but is not limited to, intelligent, multi-sensing, network-connected devices, that can integrate seamlessly with each other and/or with a central server or a cloud-computing system or any other device that is network-connected.
[0080] In an embodiment, the UE (204) may include, but is not limited to, a handheld wireless communication device (e.g., a mobile phone, a smart phone, a phablet device, and so on), a wearable computer device (e.g., a head-mounted display computer device, a head-mounted camera device, a wristwatch computer device, and so on), a Global Positioning System (GPS) device, a laptop computer, a tablet computer, or another type of portable computer, a media playing device, a portable gaming system, and/or any other type of computer device with wireless communication capabilities, and the like. In an embodiment, the user equipment (204) may include, but is not limited to, any electrical, electronic, electro-mechanical, or an equipment, or a combination of one or more of the above devices such as virtual reality (VR) devices, augmented reality (AR) devices, laptop, a general-purpose computer, desktop, personal digital assistant, tablet computer, mainframe computer, or any other computing device, wherein the UE (204) may include one or more in-built or externally coupled accessories including, but not limited to, a visual aid device such as a camera, an audio aid, a microphone, a keyboard, and input devices for receiving input from the user (202) or the entity such as touch pad, touch enabled screen, electronic pen, and the like. A person of ordinary skill in the art will appreciate that the UE (204) may not be restricted to the mentioned devices and various other devices may be used.
[0081] Referring to FIG. 2A, the UE (204) may communicate with a system (208) through a network (206). In an embodiment, the network (206) may include at least one of a Fifth-Generation (5G) network, a Sixth-Generation (6G) network, or the like. The network (206) may enable the UE (204) to communicate with other devices in the network architecture (200) and/or with the system (208). The network (206) may include a wireless card or some other transceiver connection to facilitate this communication. In another embodiment, the network (206) may be implemented as, or include any of a variety of different communication technologies such as a wide area network (WAN), a local area network (LAN), a wireless network, a mobile network, a Virtual Private Network (VPN), the Internet, the Public Switched Telephone Network (PSTN), or the like.
[0082] In accordance with embodiments of the present disclosure, the system (208) may support store and forward functionality at satellite radio base stations. The system (208) may enable a store and forward mechanism in a satellite base station (referred to as a serving satellite) depending on availability or non-availability of feeder links/core network connectivity. The system (208) may enable inter-satellite link discovery for multi-hop backhaul/feeder link scenarios. The store and forward mechanism may be effectively utilized for delay-tolerant or non-real-time services.
[0083] Although FIG. 2A shows exemplary components of the network architecture (200), in other embodiments, the network architecture (200) may include fewer components, different components, differently arranged components, or additional functional components than depicted in FIG. 2A. Additionally, or alternatively, one or more components of the network architecture (200) may perform functions described as being performed by one or more other components of the network architecture (200).
[0084] FIG. 2B illustrates an example block diagram (200B) of a system (208) for enabling a store and forward mechanism in delay-tolerant services of a serving satellite, in accordance with an embodiment of the present disclosure.
[0085] In an embodiment, and as shown in FIG. 2B, the system (208) may be associated with the serving satellite. The system (208) may include one or more processors (212). The one or more processors (212) may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processors (212) may be configured to fetch and execute computer-readable instructions stored in a memory (214) of the system (208). The memory (214) may store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory (214) may include any non-transitory storage device including, for example, volatile memory such as Random-Access Memory (RAM), or non-volatile memory such as an Erasable Programmable Read-Only Memory (EPROM), a flash memory, and the like.
[0086] In an embodiment, the system (208) may also include an interface(s) (216). The interface(s) (216) may include a variety of interfaces, for example, interfaces for data input and output devices, referred to as I/O devices, storage devices, and the like. The interface(s) (216) may facilitate communication of the system (208) with various devices coupled to it. The interface(s) (216) may also provide a communication pathway for one or more components of the system (208). Examples of such components include, but are not limited to, processing engine(s) (218) and a database (220).
[0087] In an embodiment, the processing engine(s) (218) may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine(s) (218). In examples, described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine(s) (218) may be processor-executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the one or more processors (212) may include a processing resource, to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing engine(s) (218). In such examples, the system (208) may comprise the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the system (208) and the processing resource. In other examples, the processing engine(s) (218) may be implemented by an electronic circuitry.
[0088] In an embodiment, the database (220) may include data that may be either stored or generated as a result of functionalities implemented by any of the components of the processors (212) or the processing engine(s) (218) or the system (208). In an embodiment, the database (220) may store data received from the UE (204).
[0089] In an exemplary embodiment, the processing engine(s) (218) may include one or more engines selected from any of a data ingestion engine (222) and other units/engines (224). The other units/engines (224) may include, but are not limited to, a monitoring engine, a determination engine, and the like.
[0090] In an embodiment, the one or more processors (212) may, via the data ingestion engine (222), receive data from the UE (204) which is available within a predefined range of a serving satellite, and detect an availability or unavailability of a feeder link between the serving satellite and an entity upon receiving the data. Based on the detection that the feeder link is unavailable, the one or more processors (212) may, via the data ingestion engine (222), enable store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored. The one or more processors (212) may be configured to dynamically manage a storage capacity of the memory (214) by prioritizing the received data based on predefined criteria.
[0091] Upon enabling the store and forward mechanism, the one or more processors (212) may, via the data ingestion engine (222), continuously monitor and detect one or more neighbouring satellites in proximity to the serving satellite within the predefined range. Further, the one or more processors (212) may, via the data ingestion engine (222), update an Automatic Satellite Neighbour Relations (ASNR) table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellite.
[0092] Furthermore, the one or more processors (212) may, via the data ingestion engine (222), establish an inter-satellite link (ISL) with the new neighbouring satellite, and broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites. Upon updating the ASNR table and restoration of the feeder link, the one or more processors (212) may, via the data ingestion engine (222), forward the stored data to at least one of the one or more neighbouring satellites via the ISL.
[0093] Further, the one or more processors (212) may, via the data ingestion engine (222), enable a Satellite Radio Access Network (RAN) entity to manage the UE data transmission based on the availability of the feeder link.
[0094] Although FIG. 2B shows exemplary components of the system (208), in other embodiments, the system (208) may include fewer components, different components, differently arranged components, or additional functional components than depicted in FIG. 2B. Additionally, or alternatively, one or more components of the system (208) may perform functions described as being performed by one or more other components of the system (208).
[0095] FIG. 3 illustrates an exemplary representation (300) depicting a satellite coverage area and probable neighbor satellites, in accordance with an embodiment of the present disclosure.
[0096] A moving satellite (referred to as the serving satellite) may continuously monitor the availability of the neighboring satellites on a same orbital plane, in a set range. The moving satellite may detect incoming and outgoing satellites within the neighboring parallel orbital planes, within the set range. Further, the moving satellite may detect the incoming and outgoing satellites within the neighboring perpendicular or heliptical orbital planes, within a set vicinity of interest. For each detected new neighbour satellite or incomming satellite, the serving satellite may update its Automatic Satellite Neighbour Relations [ASNR] table with new entries.
[0097] With respect to FIG. 3, in an embodiment, a satellite S6 may be considered as a serving satellite for a highlighted coverage area in black. When the serving satellite S6 detects satellite S5 as one neighbor in an orbit plane, the serving satellite S6 may add the satellite S5 in its orbit plane ASNR table. Similarly, when the serving satellite S6 detects satellite S2 as one neighbor on an adjacent parallel orbit plane, the serving satellite S6 may add the satellite S2 in its parallel orbit plane ASNR table. Also, when the serving satellite S6 detects satellite S22 and satellite S26 as other neighbors on a nearby perpendicular orbit plane, the serving satellite S6 may add the satellite S22 and the satellite S26 in its perpendicular orbit plane ASNR table. Therefore, all the prospective neighbors may be populated in the ASNR table, detected directly via an ISL link or via an assistance from the connected UEs (204). The serving satellite S6 may also create and maintain the table from intra-constellation, inter-constellation, and multi-vendor perspectives.
[0098] FIG. 4 illustrates an exemplary sequential diagram (400) for establishing an inter-satellite link with new satellites, in accordance with an embodiment of the present disclosure.
[0099] With respect to FIG. 4, the system (208) may be associated with a serving satellite (404), or the serving satellite (404) itself may act as the system (208) to establish the inter-satellite link with the new satellites, as illustrated below.
[00100] At 412, whenever a new satellite (402) or any in coming satellite is detected, the serving satellite (404) may send an ISL SETUP REQUEST message to the detected satellite (402). The ISL SETUP REQUEST message may include serving satellite details as source satellite details and also include a source satellite’s Automatic Satellite Neighbour Relations (ASNR) table list. At 414, upon receiving the ISL SETUP REQUEST message by the new satellite (402), the new satellite (402) may initiate an authentication procedure to assertain that a sender is a genuine satellite and admit the request once the authentication is successful. That is, the ISL SETUP REQUEST message may include authentication credentials to verify, by the new satellite, a legitimacy of the serving satellite (404) before establishing the ISL with the new satellite. At 416, the new satellite (402) may respond by sending an ISL SETUP RESPONSE message, which carries both the source and target satellite details and also carries its ASNR table list, and establish ISL link with the serving satellite (404).
[00101] At 418, the serving satellite (404) may update its ASNR table with the received source satellite ASNR table list. At 420a and 420b, the serving satellite (404) after receiving the response message, may update its ASNR table with the received target satellite ASNR table list, and send an ISL SETUP UPDATE message to all its neighbor satellites (406a, 406b,…,406n) as per its ASNR table, which carries the updated serving satellite’s ASNR table list. At 422a and 422b, the neighbor satellites (406a,406b,…,406n) may update their ASNR table list with the received updated serving satellite ASNR table list. This may enable the neighbor satellites (406a, 406b, …, 406n) to initiate an ISL link establishment with the new neighbor satellite entries, so that an optimized satellite mesh network may be created or maintained for quick data transfer. The satellite mesh network may enable any satellite in the network to choose the right satellite with an active feeder link for its data transfer with least delay and least number of ISL hops.
[00102] FIG. 5 illustrates an exemplary sequential diagram (500) for updating ASNR tables with ISL link status of satellites, in accordance with an embodiment of the present disclosure.
[00103] With respect to FIG. 5, the serving satellite (502) may use a flag ISL_Link_Status which may be set to either enabled or disabled according to the availability or non-availability of the ISL link with the serving satellite (502). The status of this flag may be notified to all its neighbor satellites (504a,504b,….,504n) using a message ISL_CAPABILITY_UPDATE. FIG. 5 illustrates a scenario where, when the serving satellite (502) successfully establishes the ISL link with other neighbor satellites, the flag ISL_Link_Status may be set to enabled. Whenever the serving satellite (502) experiences an out-of-synchronization condition on the ISL link with one of its neighbour satellite-1 (504a), then the serving satellite (502) may start a out-of-synchronization timer and during the time till it expires, the serving satellite (502) may keep on trying to synchronization up on the ISL link. If any synchronization on the ISL link is achieved, the serving satellite (502) may stop the timer and proceed as normal. At the expiry of the timer, the serving satellite (502) may set a flag ISL_Link_Status as disabled, for the neighbour satellite-1 (504a) entry in the ASNR table. This flag and the updated ASNR table may be updated to all its neighbour satellites (504a,504b,….,504n) by sending an ISL_CAPABILITY_UPDATE message. All the neighbour satellites (504a,504b,….,504n) receiving this message may update their ASNR tables and try to avoid the particular satellite in their path to transfer any data.
[00104] FIGs. 6A and 6B illustrate exemplary sequential diagrams (600A, 600B) for updating ASNR tables with feeder link (FL) status of satellites, in accordance with an embodiment of the present disclosure.
[00105] In an embodiment, the serving satellite (602) may use the flag FL_Link_Status which may be set to either enabled or disabled according to the availability or non-availability of the feeder link with the serving satellite. The status of this flag may be notified to all its neighbor satellites using the message ISL_CAPABILITY_UPDATE.
[00106] FIG. 6A illustrates a scenario where, when the serving satellite (602) successfully establishes the feeder link with an entity, the flag FL_Link_Status may be set to enabled. The entity may be one of a Non-Terrestrial Network Gateway (NTN GW) (604) or a ground station. Whenever the serving satellite (602) experiences an out-of-synchronization on the feeder link with one of its ground station, then the serving satellite (602) may start an out-of-synchronization timer, and during the time till it expires, the serving satellite (602) may keep on trying to synchronize up on the feeder link. If the serving satellite (602) achieves any synchronization on the ISL link, the serving satellite (602) may stop the timer and proceed as normal. At the expiry of the timer, the serving satellite (602) may set the flag FL_Link_Status as disabled, for the serving satellite entry in the ASNR table. This flag and the updated ASNR table may be updated to all its neighbour satellites (606a, 606b, ….., 606n) by sending the ISL_CAPABILITY_UPDATE message. All the neighbour satellites (606a, 606b, ….., 606n) which receives this message may update their ASNR tables and try to avoid the particular satellite in their path to transfer any data towards the ground station.
[00107] In an embodiment, the serving satellite (602) may use the flag FL_Link_Status which may be set to either enabled or disabled according to the availability or non-availability of the feeder link with the ground station or NTN GW (604). The status of this flag may be notified to all its connected neighbor satellites (606a,606b,…..,606n) using the message FL_CONFIGURATION_UPDATE.
[00108] FIG. 6B illustrates a scenario where, when the serving satellite (602) successfully establishes the feeder link with one of the NTN GW (604) or the ground station, the flag FL_Link_Status may be set to enabled at both the satellite and the ground station. The ground station may also store the ASNR tables of all the connected satellites via the feeder links and it may be getting all the updates related to the ASNR table. Whenever the ground station experiences an out-of-synchronization on the feeder link with one of its serving satellite (602), then the NTN GW (604) may start an out-of-synchronization timer and during the time till it expires, the NTN GW (604) may keep on trying to synchronize up on the feeder link. If the NTN GW (604) achieves any sync on the feeder link, the NTN GW (604) may stop the timer and proceed as normal. At the expiry of the timer, the NTN GW (604) may set the flag FL_Link_Status as disabled, for the serving satellite entry in its ASNR table. This flag and the updated ASNR table may be updated to all its connected satellites (606a,606b,…..,606n) by sending the FL_CONFIGURATION_UPDATE message. All the neighbour satellites (606a,606b,…..,606n) which receives this message may update their ASNR tables and try to avoid the particular satellite in their path to transfer any data towards the ground station.
[00109] UE (204) may also aid the serving satellites (602), by measuring neighboring satellite’s signals and updating a measurement report to the serving satellite (602). The serving satellite (602) may use this information to trigger ISL link establishment with the new satellites and update its ASNR table.
[00110] The use case on the realization of a store and forward (S&F) service between the UE (204) with the satellite access and an application server for a delay-tolerant/non-real-time Internet of Things (IoT) NTN service in the case of a mobile originated message may be described.
[00111] The service on remote monitoring (e.g., of fields) may demand deployment and tracking of many battery-powered IoT type UEs across a globe. All the IoT remote monitoring UEs going to be deployed may include a 4G/5G/6G communication with satellite access. Some of the UEs may get deployed in remote areas where there is no mobile coverage by a mobile network operator (MNO) and only satellite coverage is possible.
[00112] For the satellite access, the more popular option is to use an LEO constellation which supports an S&F operation mode.
[00113] All IoT remote monitoring UEs may regularly send information related to the area they are monitoring to the relevant application server and sometimes receive new parameters from the application server. In most of the cases, the messages exchanged may be delay-tolerant/non-real-time IoT.
[00114] FIG. 7 illustrates an exemplary representation (700) depicting a satellite with a direct feeder link, in accordance with an embodiment of the present disclosure.
[00115] In an embodiment, the S&F may not be applied even for the delay tolerant or non-real time services, whenever a serving satellite (702) has a direct feeder link with a ground station. FIG. 7 illustrates a use case scenario, where S&F support is not needed, as the serving satellite (702) has a direct active feeder link with an NTN GW (706). Hence, the serving satellite (702) may immediately forward the message from an IoT device (704) towards the NTN GW (706), the moment the message is received.
[00116] FIG. 8 illustrates an exemplary representation (800) depicting a satellite having access to a ground station through an indirect feeder link via ISL links, in accordance with an embodiment of the present disclosure.
[00117] In an embodiment, the S&F may not be applied even for the delay tolerant or non-real-time services, whenever the serving satellite has the indirect feeder link with the ground station via the ISL link. FIG. 8 illustrates the use case scenario, where the S&F support is not needed, as the satellite has the indirect active feeder link with the NTN GW (806), via ISL link. Hence, the satellite A (802a) immediately forwards the message from the IoT device (804), the moment the message is received, towards the Satellite B (802b) via the ISL link, which in turn forwards it towards the NTN GW (806) immediately.
[00118] FIG. 9 illustrates an exemplary representation (900) depicting a satellite in a coreless mode without direct feeder link, in accordance with an embodiment of the present disclosure.
[00119] In an embodiment, the S&F may be applied for all the delay tolerant or non-real-time services, whenever the serving satellite does not have the feeder link with the ground station. FIG. 9 illustrates the use case scenario, where an S&F support is needed, as a satellite (902) does not have direct active feeder link with an NTN GW (906). Hence, the satellite (902) may immediately store the message received from an IoT device (904) locally, the moment the message is received. Later, when the satellite (902) establishes the active feeder link directly or indirectly, the satellite (902) may forward the stored messages towards the NTN GW (906).
[00120] FIG. 10 illustrates an exemplary representation (1000) depicting a satellite in a coreless mode without either direct or indirect feeder link, in accordance with an embodiment of the present disclosure.
[00121] In an embodiment, the S&F may be applied for all the delay tolerant or non-real-time services, whenever the serving satellite does not have either direct or indirect feeder link with the ground station. FIG. 10 illustrates the use case scenario, where the S&F support is needed, as the satellite does not have both direct and indirect active feeder links with the NTN GW (1006). Even though, the satellite gNB A (1002a) have the active ISL link with the satellite gNB B (1002b), the satellite gNB B (1002b) may not have its active feeder link in any form. Hence, the satellite gNB A (1002a) may immediately store the message locally, the moment the message is received. Later, when the satellite gNB A (1002a) learns from the satellite gNB B (1002b) regarding the availability of the active feeder link via ISL link, the satellite gNB A (1002a) may forward the stored messages towards the satellite gNB B (1002b) via the ISL link, which in turn forwards all the received messages towards the NTN GW (1006) via its active feeder link.
[00122] FIG. 11 illustrates an exemplary representation (1100) depicting a satellite with gNodeB-Distribution Unit (gNB-DU) payload in a coreless mode without a direct feeder link, in accordance with an embodiment of the present disclosure.
[00123] In an embodiment, the S&F may be applied for all the delay tolerant or non-real-time services, whenever the serving satellite with a gNB-DU payload does not have the feeder link with the ground station in any form. S&F functionality may be storing L2-level packets for each UE (204). FIG. 11 illustrates the use case scenario, where the S&F support is needed, as the satellite gNB-DU (1102) does not have direct active feeder link with an NTN GW (1106). Hence, the satellite gNB-DU (1102) may immediately store the message (packets) at L2 level locally, the moment the message (packets) is received. Later, when the satellite gNB-DU (1102) establishes the active feeder link directly or indirectly, the satellite gNB-DU (1102) may forward the stored messages (packets) towards the NTN GW (1106).
[00124] FIG. 12 illustrates an exemplary representation (1200) depicting a satellite with gNB-Radio Unit (gNB-RU) payload in a coreless mode without a direct feeder link, in accordance with an embodiment of the present disclosure.
[00125] In an embodiment, the S&F may be applied for all the delay tolerant or non-real-time services, whenever the serving satellite with gNB-RU payload does not have the feeder link with the ground station in any form. S&F functionality may be storing the L1 level packets for each UE (204). FIG. 12 illustrates the use case scenario, where S&F support is needed, as the satellite gNB-RU (1202) does not have direct active feeder link with the NTN GW (1206). Hence, the satellite gNB-RU (1202) may immediately store the message (Transport Blocks (TBs)) at L1 PHY level locally, the moment the message (TBs) is received. Later, when the satellite gNB-RU (1202) establishes the active feeder link directly or indirectly, the satellite gNB-RU (1202) may forward the stored messages (TBs) towards the NTN GW (1206).
[00126] FIG. 13 illustrates an exemplary representation (1300) depicting a satellite with a bent pipe payload in a coreless mode without a direct feeder link, in accordance with an embodiment of the present disclosure.
[00127] In an embodiment, the S&F may be applied for all the delay tolerant or non-real-time services, whenever the serving satellite with bent pipe payload does not have the feeder link with the ground station in any form. S&F functionality may be storing Radio Frequency (RF) level data for each UE (204). FIG. 13 illustrates the use case scenario, where S&F support is needed, as the satellite (1302) with bent pipe payload does not have direct active feeder link with the NTN GW (1306). Hence, the satellite (1302) may immediately store the message locally at the RF level [low PHY level], the moment the message [data] is received. Later, when the satellite (1302) establishes the active feeder link directly or indirectly, the satellite (1302) may forward the stored messages [data] towards the NTN GW (1306).
[00128] FIG. 14 illustrates an exemplary representation (1400) depicting a satellite broadcasting a store and forward (S&F) support and other status flags, in accordance with an embodiment of the present disclosure.
[00129] In another embodiment, the serving satellite (1402) may broadcast one or more capability parameters to the UEs (204) to enable the UEs (204) to determine a time to transmit the data. The one or more capability parameters may include a store and forward mechanism, feeder link availability status, and ISL availability status. The serving satellite (1402) may be broadcasting its capability on supporting S&F functionalities, FL_Link_Status, ISL_Link_Status, and enabling the UEs (204) to autonomously decide on when to send and when to delay sending the messages towards the serving satellite (1402). FIG. 14 illustrates a notification mechanism about its capabilities. The S&F capability indicates to the IoT device (1404) that the satellite access has S&F support. When the IoT device (1404) learns from the notification that the feeder link available status is either direct or via ISL, the IoT device (1404) may blindly send the messages any time towards the satellite (1402) via a service link. When the notification says there is no feeder link available or the feeder link is available via ISL link which is multi-HOP, then the IoT device (1404) may take the decision whether to send the message now or delay sending the message, may be by storing the message locally. Only in this case, the S&F may be used either at the satellite (1402), or at the device (1404), or both.
[00130] FIG. 15 illustrates an exemplary computer system (1500) in which or with which embodiments of the present disclosure may be implemented.
[00131] As shown in FIG. 15, the computer system (1500) may include an external storage device (1510), a bus (1520), a main memory (1530), a read only memory (1540), a mass storage device (1550), a communication port (1560), and a processor (1570). A person skilled in the art will appreciate that the computer system (1500) may include more than one processor (1570) and communication ports (1560). Processor (1570) may include various modules associated with embodiments of the present disclosure.
[00132] In an embodiment, the communication port (1560) may be any of an RS-232 port for use with a modem-based dialup connection, a 10/100 Ethernet port, a Gigabit or 10 Gigabit port using copper or fiber, a serial port, a parallel port, or other existing or future ports. The communication port (1560) may be chosen depending on a network, such a Local Area Network (LAN), Wide Area Network (WAN), or any network to which the computer system (1500) connects.
[00133] In an embodiment, the memory (1530) may be Random Access Memory (RAM), or any other dynamic storage device commonly known in the art. Read-only memory (1540) may be any static storage device(s) e.g., but not limited to, a Programmable Read Only Memory (PROM) chips for storing static information e.g., start-up or Basic Input/Output System (BIOS) instructions for the processor (1570).
[00134] In an embodiment, the mass storage device (1550) may be any current or future mass storage solution, which may be used to store information and/or instructions. Exemplary mass storage solutions include, but are not limited to, Parallel Advanced Technology Attachment (PATA) or Serial Advanced Technology Attachment (SATA) hard disk drives or solid-state drives (internal or external, e.g., having Universal Serial Bus (USB) and/or Firewire interfaces), one or more optical discs, Redundant Array of Independent Disks (RAID) storage, e.g., an array of disks (e.g., SATA arrays).
[00135] In an embodiment, the bus (1520) communicatively couples the processor(s) (1570) with the other memory, storage and communication blocks. The bus (1520) may be, e.g., a Peripheral Component Interconnect (PCI)/PCI Extended (PCI-X) bus, Small Computer System Interface (SCSI), Universal Serial Bus (USB) or the like, for connecting expansion cards, drives and other subsystems as well as other buses, such a front side bus (FSB), which connects the processor (1570) to the computer system (1500).
[00136] Optionally, operator and administrative interfaces, e.g., a display, keyboard, joystick, and a cursor control device, may also be coupled to the bus (1520) to support direct operator interaction with the computer system (1500). Other operator and administrative interfaces may be provided through network connections connected through the communication port (1560). Components described above are meant only to exemplify various possibilities. In no way should the aforementioned exemplary computer system (1500) limit the scope of the present disclosure.
[00137] While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The scope of the present disclosure is determined by the claims that follow. The present disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the present disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[00138] The present disclosure provides a system and a method for supporting delay tolerance in satellite radio access functionality.
[00139] The present disclosure enables efficient mechanisms where a satellite system provides some level of services even when a satellite loses a feeder link connectivity with a ground station, which is connected to a core network and supported application servers.
[00140] The present disclosure continuously monitors availability of neighboring satellites on a same orbital plane, in a set range.
[00141] The present disclosure detects incoming and outgoing satellites within the neighboring parallel orbital planes, within the set range.
[00142] The present disclosure detects incoming and outgoing satellites within the neighboring perpendicular or heliptical orbital planes, within the set vicinity of interest.
[00143] The present disclosure establishes an inter-satellite link with new satellites.
[00144] The present disclosure chooses, for any satellite in a network, an exact satellite with an active feeder link for data transfer with least delay and least number of ISL hops.
[00145] The present disclosure applies Store and Forward (S&F) mechanism for all delay tolerant or non-real time services, whenever a serving satellite does not have either direct or indirect feeder link with a ground station, and the serving satellite with a base station payload or a bent pipe payload does not have the feeder link with the ground station in any form.
[00146] The present disclosure enables the satellite in a coreless radio access mode to locally authenticate new User Equipments (UEs) and allow the delay tolerant or non-real-time services for that UE, and once the feeder link is restored, actual authentication with the core network may be initiated.
,CLAIMS:1. A system (208) for enabling a store and forward mechanism in delay-tolerant services of a serving satellite, the system (208) comprising:
a processor (212); and
a memory (214) operatively coupled to the processor (212), wherein the memory (214) comprises processor-executable instructions, which on execution, cause the processor (212) to:
receive data from at least one User Equipment (UE) (204), wherein the at least one UE (204) is available within a predefined range of the serving satellite;
detect an availability or unavailability of a feeder link between the serving satellite and an entity upon receiving the data;
based on the detection that the feeder link is unavailable, enable store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored;
upon enabling the store and forward mechanism, continuously monitor and detect one or more neighbouring satellites in proximity to the serving satellite within the predefined range;
update an Automatic Satellite Neighbour Relations (ASNR) table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites;
establish an inter-satellite link (ISL) with the new neighbouring satellite;
broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites; and
upon updating the ASNR table and restoration of the feeder link, forward the stored data to at least one of the one or more neighbouring satellites via the ISL.
2. The system (208) as claimed in claim 1, wherein the processor (212) is configured to continuously monitor and detect the one or more neighbouring satellites in at least one of: same orbital plane, neighboring parallel orbital planes, and neighboring perpendicular or heliptical orbital planes.
3. The system (208) as claimed in claim 1, wherein the processor (212) is configured to establish the ISL with the new neighbouring satellite by:
sending a ISL setup request message to the new neighbouring satellite, wherein the ISL setup request message comprises information related to the serving satellite as details of one or more source satellites and an ASNR table list of the one or more source satellites;
based on a successful authentication, receiving a ISL setup response message from the new neighbouring satellite, wherein the ISL setup response message comprises the details of the one or more source satellites, details of the new neighbouring satellite as details of a target satellite, the ASNR table list of both the one or more source satellites and the target satellite;
upon receiving the ISL setup response message, update the ASNR table list of the one or more source satellites with the received ASNR table list of the target satellite; and
establish the ISL with the new neighbouring satellite upon updating the ASNR table list of the one or more source satellites.
4. The system (208) as claimed in claim 3, wherein upon updating the ASNR table list of the one or more source satellites, the processor (212) is configured to:
send an ISL setup update message to all the one or more neighbouring satellites, wherein the ISL setup update message comprises the updated ASNR table list of the one or more source satellites,
wherein the one or more neighbouring satellites update the ASNR table list with the received updated ASNR table list of the one or more source satellites to enable the one or more neighbouring satellites to initiate ISL establishment with the new neighbouring satellite.
5. The system (208) as claimed in claim 3, wherein the ISL setup request message comprises authentication credentials to verify, by the new neighbouring satellite, a legitimacy of the serving satellite before establishing the ISL with the new neighbouring satellite.
6. The system (208) as claimed in claim 3, wherein the processor (212) is configured to set an ISL link status flag in the serving satellite to enable or disable based on an availability of the ISL.
7. The system (208) as claimed in claim 6, wherein the processor (212) is configured to:
set the ISL link status flag to enable upon successful establishment of the ISL with the one or more neighbouring satellites;
initiate an out-of-synchronization timer and attempt to re-establish synchronization, within a predefined time window, with the one or more neighbouring satellites, based on a detection of an out-of-synchronization condition on the established ISL;
perform at least one of:
resume normal operation to forward the stored data to the at least one of the one or more neighbouring satellites and retain the enable status for the ISL link status flag if the synchronization is restored before an expiry of the out-of-synchronization timer; and
set the ISL link status flag to disable for at least one affected neighbouring satellite entry in the ASNR table if the synchronization is not restored upon expiry of the out-of-synchronization timer; and
transmit an ISL capability update message comprising updated ISL link status flag and the ASNR table to all the one or more neighbouring satellites,
wherein upon receiving the ISL capability update message, the one or more neighbouring satellites update the ASNR table accordingly and dynamically adjust data routing paths to avoid relying on the affected neighbouring satellite for data transfer.
8. The system (208) as claimed in claim 1, wherein the processor (212) is configured to set a FL link status flag in the serving satellite to enable or disable based on the availability and establishment of the feeder link with the entity.
9. The system (208) as claimed in claim 8, wherein the processor (212) is configured to:
set the FL link status flag to enable, upon successful establishment of the feeder link with the entity;
based on a detection of an out-of-synchronization condition on the feeder link, initiate an out-of-synchronization timer and continuously attempt to re-establish synchronization, within a predefined time period, with the entity;
perform at least one of:
resume normal operation to forward the stored data to the entity and retain the enable status for the feeder link if the synchronization is restored before an expiry of the out-of-synchronization timer; and
set the FL link status flag to disable for at least one affected neighbouring satellite entry in the ASNR table if the synchronization is not restored upon expiry of the out-of-synchronization timer; and
transmit an ISL capability update message comprising updated FL link status flag and the ASNR table to all the one or more neighbouring satellites,
wherein upon receiving the ISL capability update message, the one or more neighbouring satellites update the ASNR table accordingly and dynamically adjust data routing paths to avoid relying on the affected neighbouring satellite for data transfer toward the entity.
10. The system (208) as claimed in claim 8, wherein the processor (212) is configured to:
transmit a FL link status to all one or more connected neighbouring satellites using an FL configuration update message;
upon successful establishment of the feeder link with the entity, set the FL link status to enable at both the serving satellite and the entity, wherein the entity maintains updated ASNR tables of all the one or more connected neighbouring satellites via the feeder link;
if the entity experiences an out-of-synchronization condition with the serving satellite, initiate an out-of-synchronization timer and continuously attempt to re-establish synchronization, within a predefined time period, with the entity; and
perform at least one of:
if synchronization is achieved before an expiry of the out-of-synchronization timer, resume normal operation to forward the stored data to the entity; or
upon expiry of the out-of-synchronization, set the FL link status to disable for corresponding satellite entry in the ASNR table of the entity,
wherein the entity transmits the FL configuration update message to all the one or more connected satellites, prompting the one or more connected satellites to update the ASNR tables and exclude the affected satellite from data transmission paths toward the entity.
11. The system (208) as claimed in claim 1, wherein the processor (212) is configured to:
continuously monitor and detect a status of the feeder link; and
perform one of:
based on the detection of an active direct feeder link with the entity, bypass the store and forward mechanism and immediately forward the received data toward the entity; and
based on the detection of disruption of the feeder link, dynamically enable to the store and forward mechanism to ensure uninterrupted data transmission.
12. The system (208) as claimed in claim 1, wherein the processor (212) is configured to:
detect an availability of an indirect feeder link with the entity via the ISL; and
perform at least one of:
based on a detection of an active ISL with at least one neighbouring satellite that has a direct feeder link to the entity, immediately forward the received data to the entity via the ISL without storing the received data; or
based on a detection of a disruption of the ISL, dynamically switch to the store and forward mechanism to ensure uninterrupted data transmission to the entity.
13. The system (208) as claimed in claim 1, wherein the processor (212) is configured to:
identify the unavailability of the feeder link with the entity;
based on the identification, store the received data locally in the memory until the feeder link is established;
continuously monitor the availability of a direct or indirect feeder link with the entity; and
upon establishing the active feeder link, either directly or indirectly via the ISL, immediately forward the stored data towards the entity.
14. The system (208) as claimed in claim 13, wherein the processor (212) is configured to dynamically manage a storage capacity of the memory by prioritizing the received data based on predefined criteria.
15. The system (208) as claimed in claim 1, wherein the processor (212) is configured to apply a store and forward mechanism for all delay-tolerant or non-real-time services when the serving satellite with a payload does not have the feeder link with the entity.
16. The system (208) as claimed in claim 1, wherein the processor (212) is configured to broadcast one or more capability parameters to the at least one UE (204) to enable the at least one UE (204) to determine a time to transmit the data, and wherein the one or more capability parameters comprise a store and forward mechanism, feeder link availability status, and ISL availability status.
17. The system (208) as claimed in claim 1, wherein the processor (212) is configured to locally authenticate the at least one UE (204) and facilitate the delay-tolerant or non-real-time services while operating in a coreless radio access mode.
18. The system (208) as claimed in claim 1, wherein the processor (212) is configured to enable a Satellite Radio Access Network (RAN) entity to manage UE data transmission based on the availability of the feeder link.
19. The system (208) as claimed in claim 1, wherein the entity is at least one of: a ground station and a Non-Terrestrial Network (NTN) Gateway (GW).
20. A method for enabling a store and forward mechanism in delay-tolerant services of a serving satellite, the method comprising:
receiving, by a processor (212) associated with a system (208), data from at least one User Equipment UE (204), wherein the at least one UE (204) is available within a predefined range of the serving satellite;
detecting, by the processor (212), an availability or unavailability of a feeder link between the serving satellite and an entity;
based on the detection that the feeder link is unavailable, enabling, by the processor (212), a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored;
upon enabling the store and forward mechanism, continuously monitoring and detecting, by the processor (212), one or more neighbouring satellites in proximity to the serving satellite within the predefined range;
updating, by the processor (212), an Automatic Satellite Neighbour Relations (ASNR) table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites;
establishing, by the processor (212), an inter-satellite link (ISL) with the new neighbouring satellite;
broadcasting, by the processor (212), an availability of the ISL to the one or more neighbouring satellites and updating the ASNR table of the one or more neighbouring satellites; and
upon updating the ASNR table and restoration of the feeder link, forwarding, by the processor (212), the stored data to at least one of the one or more neighbouring satellites via the ISL.
21. A User Equipment UE (204) comprising:
a processor; and
a memory operatively coupled to the processor, wherein the memory comprises processor-executable instructions, which on execution, cause the processor to:
transmit data to a system,
wherein the processor is communicatively coupled with the system, and wherein the system is configured to:
receive the data from the UE (204);
detect an availability or unavailability of a feeder link between the serving satellite and an entity upon receiving the data;
based on the detection that the feeder link is unavailable, enable a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored;
upon enabling the store and forward mechanism, continuously monitor and detect one or more neighbouring satellites in proximity to the serving satellite within the predefined range;
update an Automatic Satellite Neighbour Relations (ASNR) table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites;
establish an inter-satellite link (ISL) with the new neighbouring satellite;
broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites; and
upon updating the ASNR table and restoration of the feeder link, forward the stored data to at least one of the one or more neighbouring satellites via the ISL.
22. The UE (204) as claimed in claim 21, wherein prior to transmitting the data to the system, the processor is configured to:
establish a connection with the system;
receive one or more capability parameters from the system; and
determine a time to transmit the data to the system based on the one or more capability parameters.
23. The UE (204) as claimed in claim 22, wherein the one or more capability parameters comprise a store and forward mechanism, feeder link availability status, and ISL availability status.
24. The UE (204) as claimed in claim 23, wherein upon receiving the one or more capability parameters from the system, the processor is configured to:
determine an availability or unavailability of the feeder link based on the one or more capability parameters;
transmit the data immediately either directly or via a single-hop ISL based on a detection that the feeder link is available; and
autonomously decide whether to transmit the data immediately or delay transmission by storing the data locally, based on a detection that the feeder link is unavailable or the feeder link is only accessible via a multi-hop ISL path.
25. A non-transitory computer-readable medium comprising processor-executable instructions that cause a processor to:
receive data from a User Equipment UE (204);
detect an availability or unavailability of a feeder link between the serving satellite and an entity upon receiving the data;
based on the detection that the feeder link is unavailable, enable a store and forward mechanism in delay-tolerant services within the serving satellite to temporarily store the received data until the feeder link is restored;
upon enabling the store and forward mechanism, continuously monitor and detect one or more neighbouring satellites in proximity to the serving satellite within the predefined range;
update an Automatic Satellite Neighbour Relations (ASNR) table of a new neighbouring satellite based on a detection that the new neighbouring satellite is available, within the predefined range, other than the one or more neighbouring satellites;
establish an inter-satellite link (ISL) with the new neighbouring satellite;
broadcast an availability of the ISL to the one or more neighbouring satellites and update the ASNR table of the one or more neighbouring satellites; and
upon updating the ASNR table and restoration of the feeder link, forward the stored data to at least one of the one or more neighbouring satellites via the ISL.