Subscription-based satellite access

Abstract

Example embodiments of the present disclosure relate to subscription-based satellite access. The method comprises the following steps: sending a registration message to first network equipment; and receiving, from the first network device, an indication of whether the user equipment has subscribed to satellite access.

Description

TECHNICAL FIELD

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunications, and in particular, to apparatuses, methods, and computer-readable storage media for subscription-based satellite access. BACKGROUND

[0002] User Equipment (UE)-Satellite-UE (also referred to as UE-Sat-UE) communication refers to communication between UEs under the coverage of one or more serving satellites without using a terrestrial network. There is a direct satellite-satellite link that can be used for user plane traffic. Data can be sent directly from one satellite to another satellite, rather than sending data from one satellite to a terrestrial network and then from the terrestrial network to another satellite. In order to support Internet Protocol (IP) Multimedia Subsystem (IMS) media (e.g., video call) via UE-Sat-UE routing, an IMS Access Gateway (AGW) needs to be installed on each satellite. The direct satellite-satellite link can reduce the latency of IMS media routing. SUMMARY

[0003] In a first aspect of the present disclosure, a user equipment is provided. The user equipment comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to at least: send, to a first network equipment, a registration message; and receive, from the first network equipment, an indication of whether the user equipment has subscribed to the satellite access.

[0004] In a second aspect of the present disclosure, a first network equipment is provided. The first network equipment comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first network equipment to at least: receive, from a user equipment, a registration message; in response to receiving the registration message from the user equipment, forward the registration message to a second network equipment; and receive, from the second network equipment, subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to the satellite access.

[0005] In a third aspect of the present disclosure, a second network equipment is provided. The second network equipment comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second network equipment to at least: receive, from a first network equipment, a registration message of a user equipment; and obtain subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to the satellite access.

[0006] In a fourth aspect of the disclosure, a method is provided. The method comprises: sending, to a first network device, a registration message; and receiving, from the first network device, an indication of whether the user equipment has subscribed to the satellite access.

[0007] In a fifth aspect of the disclosure, a method is provided. The method comprises: receiving, from a user equipment, a registration message; forwarding, to a second network device, the registration message in response to receiving the registration message from the user equipment; and receiving, from the second network device, subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0008] In a sixth aspect of the disclosure, a method is provided. The method comprises: receiving, from a first network device, a registration message of a user equipment; and obtaining subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0009] In a seventh aspect of the disclosure, a user equipment is provided. The user equipment comprises: means for sending, to a first network device, a registration message; and means for receiving, from the first network device, an indication of whether the user equipment has subscribed to the satellite access.

[0010] In an eighth aspect of the disclosure, a first network device is provided. The first network device comprises: means for receiving, from a user equipment, a registration message; means for forwarding, to a second network device, the registration message in response to receiving the registration message from the user equipment; and means for receiving, from the second network device, subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0011] In a ninth aspect of the disclosure, a second network device is provided. The second network device comprises: means for receiving, from a first network device, a registration message of a user equipment; and means for obtaining subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0012] In a tenth aspect of the disclosure, a computer readable medium is provided. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

[0013] In an eleventh aspect of the disclosure, a computer readable medium is provided. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fifth aspect.

[0014] In a twelfth aspect of the disclosure, a computer readable medium is provided. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the sixth aspect.

[0015] It is to be understood that the Summary is not intended to identify key or essential features of embodiments of the disclosure, nor is it intended to limit the scope of the disclosure. Other features of the disclosure will be apparent from review of the disclosure, which is described in its entirety in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0016] Some example embodiments will now be described with reference to the following drawings:

[0017] Figure 1 FIGURE 1 illustrates an example communication environment in which example embodiments of the disclosure can be implemented;

[0018] Figure 2A FIGURE 2 illustrates an example of an IMS user plane without UE-Sat-UE optimization;

[0019] Figure 2B FIGURE 3 illustrates an example of an IMS user plane using UE-Sat-UE optimization;

[0020] Figure 2C FIGURE 4 illustrates an example of AGW resource allocation in a satellite;

[0021] Figure 3 FIGURE 5 illustrates a signaling diagram of an example procedure for subscription based satellite access according to some example embodiments of the disclosure;

[0022] Figure 4 FIGURE 6 illustrates an example procedure for removing additional header information based on subscription information according to some example embodiments of the disclosure;

[0023] Figure 5 FIGURE 7 illustrates an example procedure for subscription information acquisition at IMS registration according to some example embodiments of the disclosure;

[0024] Figure 6 FIGURE 8 illustrates a signaling diagram for subscription based UE-Sat-UE communication according to some example embodiments of the disclosure;

[0025] Figure 7 FIGURE 9 illustrates an example procedure for subscription based UE-Sat-UE communication according to some example embodiments of the disclosure;

[0026] Figure 8 FIGURE 10 illustrates a flow diagram of an example method implemented at a user equipment according to some example embodiments of the disclosure;

[0027] Figure 9 FIGURE 11 illustrates a flow diagram of an example method implemented at a first network device according to some example embodiments of the disclosure;

[0028] Figure 10FIG. 1 illustrates a flow diagram of an example method implemented at a first network device, according to some example embodiments of the present disclosure;

[0029] Figure 11 is a simplified block diagram of a device suitable for implementing example embodiments of the present disclosure; and

[0030] Figure 12 FIG. 1 illustrates a flow diagram of an example method implemented at a first network device, according to some example embodiments of the present disclosure;

[0031] Throughout the drawings, identical or similar reference numerals designates identical or similar elements. DETAILED DESCRIPTION

[0032] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only and help the skilled person to understand and implement the present disclosure, without implying any limitation to the scope of the present disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0033] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0034] Reference in the specification to “one (1) embodiment”, “an (1) embodiment”, “one (1) example embodiment” or similar terms, means that a described embodiment might include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Furthermore, such phrases or phrases do not necessarily refer to the same embodiment. Also, depending on the circumstances, the particular feature, structure, or characteristic can be combined with one or more other particular features, structures, or characteristics.

[0035] It should be understood that although the terms “first”, “second” … etc. before the noun(s) can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another, and do not limit the order of the noun(s). For example, a first element can also be referred to as a second element, and similarly a second element can also be referred to as a first element, without departing from the scope of the example embodiments. As used herein, the term “and / or” includes any combination and all combinations of one or more of the listed terms.

[0036] As used herein, "at least one of " and "one or more of " and similar phrases, where a list of two or more elements is preceded by "at least one of" or "one or more of," means that at least any one of the listed elements, or at least any two or more of the listed elements, or at least all of the listed elements.

[0037] Unless specifically stated otherwise, as used herein, performing an action "in response to" an event does not mean the action is performed immediately after the event occurs and that no intervening actions can be included.

[0038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and / or "including" when used herein, specify the presence of stated features, elements and / or components etc. but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0039] As used in this application, the term "circuitry" can refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) combinations of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processors); software, including one or more applications, and sub-processors, that work together to cause an apparatus, such as a mobile phone or server, to perform various functions and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s), or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but need not necessarily have software present at all times that the hardware circuit(s) and or processor(s) are operating.

[0040] This definition of "circuitry" applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation consisting of processor(s) or digital signal processor(s) ("DSP") and memory combined with software such that the memory provides at least in part the instruction

[0041] As used herein, the term "communication network" refers to a network that follows any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT), etc. Further, the communication between terminal devices and network devices in a communication network can be performed in accordance with any suitable generation communication protocol, including but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), 5.5G, sixth generation (6G) communication protocols, and / or any other protocol that is currently known or that will be developed in the future. Embodiments of the present disclosure can be applied to various communication systems. In light of the rapid development of communication, there will of course also be future types of communication technologies and systems that the present disclosure can utilize without deviating from the scope of the present disclosure. It should not be seen as limiting the scope of the present disclosure to only the above-described systems.

[0042] As used herein, the term “network device” refers to a node in a communication network via which terminal devices access the network and receive services therefrom. Depending on the terminology used, network devices can include network devices of an access network, including base stations (BSs) or access points (APs), e.g., NodeBs (NodeB or NB), evolved NodeBs (eNodeB or eNB), NR NBs (also referred to as gNBs), remote radio units (RRUs), radio heads (RHs), remote radio heads (RRHs), relays, integrated access and backhaul (IAB) nodes, low power nodes (such as femto, pico), non-terrestrial networks (NTN) or non-ground based network devices (such as satellite network devices, low earth orbit (LEO) satellites, and geosynchronous earth orbit (GEO) satellites), aerial network devices, etc. In some example embodiments, a radio access network (RAN) split architecture includes a centralized unit (CU) at an IAB donor node and a distributed unit (DU). An IAB node includes a mobile termination (IAB-MT) part that behaves like a UE towards a parent node, and a DU part of the IAB node that behaves like a base station towards a next-hop IAB node.

[0043] Network devices can also include network devices of a core network, examples of which can include one or more functions of a mobility management entity (MME), an evolved packet data gateway (ePDG), a home subscriber server (HSS), an access and mobility management function (AMF), a session management function (SMF), a network slice selection function (NSSF), a serving gateway (SGW), a packet gateway (PGW), a policy control function (PCF), a session management function (SMF), an authentication server function (AUSF), a subscription identifier de-crypt function (SIDF), a unified data management (UDM), a security edge protection proxy (SEPP), a network exposure function (NEF), and / or a user plane function (UPF).

[0044] The term "terminal device" refers to any terminal device that can be capable of wireless communication. By way of example and not limitation, a user device can also be referred to as a communication device, user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). A terminal device can include, but is not limited to, a mobile phone, a cellular phone, a smartphone, a voice over Internet Protocol (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device, such as a digital camera, a game terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a USB dongle, a smart device, a wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots in industrial and / or

[0045] As used herein, the terms "resource," "transmission resource," "resource block," "physical resource block" (PRB), "uplink resource," or "downlink resource" can refer to any resource used to perform communication, such as a terminal device and a network device, such as a resource on a time domain, a resource on a frequency domain, a resource on a spatial domain, a resource on a code domain, or any other combination of time, frequency, spatial, and / or code domain resources that enable communication, etc. Hereinafter, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources to describe some example embodiments of the present disclosure. It should be noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0046] Satellites can be used to enhance service coverage to UEs. For example, during an IMS call, media can be routed from a UE to a satellite, and then a feeder link can be used to route the media from the satellite to a terrestrial IMS network, in turn to another satellite. However, the bandwidth of the feeder link can not be consistent, and the bandwidth can be limited. This makes the use of the feeder link for the user plane a non-preferred way for IMS voice or video calls. Operators are seeking ways to provide UE-Sat-UE media routing optimization for premium customers. UE-Sat-UE can enable media routing via a satellite without the need to use terrestrial resources, which can reduce routing latency.

[0047] In a non-terrestrial network (NTN) scenario, when a UE requests a call (e.g., an IMS video call), a proxy call session control function (P-CSCF) can know that the UE has been connected to a satellite access node, and that UE-Sat-UE is generally available in the NTN. Traditionally, the P-CSCF can add a specific header including satellite related information. However, in some cases, UE-Sat-UE mode can not be supported.

[0048] Example embodiments of the present disclosure provide a solution for subscription based satellite access. In the solution, a user equipment (such as a UE) sends a registration message to a first network device (such as a P-CSCF). In response to receiving the registration message from the user equipment, the first network device forwards the registration message to a second network device (such as a serving call session control function (S-CSCF)). The second network device obtains subscription information of the user equipment, which indicates whether the user equipment has subscribed to satellite access (e.g., UE-Sat-UE). The subscription information can be obtained by a network device (such as a home subscriber server). Based on the subscription information, the second network device determines whether the user equipment is allowed or not allowed to have satellite access. Then, a call setup procedure of the user equipment can be performed based on the subscription information to enable or disable satellite access (e.g., UE-Sat-UE), which is more flexible and efficient.

[0049] In some example embodiments, the second network device can send the subscription information to the first network device, and the first network device can further send the subscription information to the user equipment. During the call setup procedure of the user equipment, the user equipment and / or the first network device can utilize the subscription information to flexibly enable or disable satellite access in the subsequent call setup procedure.

[0050] Figure 1 FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented.

[0051] As Figure 1As shown in FIG. 1, the communication environment 100 can include a user equipment 110 (such as a UE), an access network device 140 (such as a gNB), and a non-terrestrial network device 150. The non-terrestrial network device 150 can operate as a satellite or any other non-terrestrial network device. The access network device 140 can provide service with the non-terrestrial network device 150 and other non-terrestrial network devices (not shown) within a coverage area, referred to as a cell 125. The non-terrestrial network device 150 can communicate with the user equipment 110 via a service link or wireless interface, and the non-terrestrial network device 150 can communicate with the access network device 140 via a feeder link or wireless interface.

[0052] The access network device 210 can also be connected to a core network 160 in a wired or wireless manner. The core network 160 can include the first network device 120, the second network device 130, and other network devices (not shown) to provide management functions to the access network device 140, the non-terrestrial network device 150, and the user equipment 110. The first network device 120 and the second network device 130 can communicate with each other to provide various management services. In an example, the first network device 120 can operate as a P-CSCF that can be deployed in the core network. The second network device 130 can operate as a serving call session control function (S-CSCF) that can be deployed in the core network.

[0053] It should be understood that Figure 1 The number of devices shown in FIG. 1 and their connections is for illustration only, and does not imply any limitation with regard to the examples embodiments of the present disclosure. The communication environment 100 can include any suitable number of devices configured to implement the example embodiments of the present disclosure. For example, the communication environment 100 can include any suitable number of user equipment, access network devices, non-terrestrial network devices, and core network devices for implementing the example embodiments of the present disclosure.

[0054] In some example embodiments, the transmission direction from the access network device 210 to the user equipment 110 is referred to as the downlink (DL), and the transmission direction from the user equipment 110 to the access network device 210 is referred to as the uplink (UL). In the DL, the access network device 210 is a transmitting (TX) device (or transmitter), and the user equipment 110 is a receiving (RX) device (or receiver). In the UL, the user equipment 110 is a TX device (or transmitter), and the access network device 210 is an RX device (or receiver).

[0055] Communications in the communication environment 100 can be implemented according to any appropriate communications protocol(s), including but not limited to cellular communications protocols, wireless local area network communications protocols (such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc.), and / or any other protocol(s) that are currently known or that will be developed in the future. Additionally, communications can utilize any appropriate wireless communications technology, including but not limited to code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple-input multiple-output (MIMO), orthogonal frequency division multiple access (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other technology that is currently known or that will be developed in the future.

[0056] For example, UE-Sat-UE can be used to enhance routing for IMS media. Figure 2A An example procedure for an IMS call without UE-Sat-UE optimization is illustrated. As shown in Figure 2A The feeder link is used to route media to the ground IMS network. Because of the use of the feeder link, this increases latency (additional path delay). Figure 2B An example procedure for an IMS call using UE-Sat-UE optimization is illustrated. As shown in Figure 2B The direct satellite-satellite link is used for user plane traffic. Instead of sending media from satellite 1 210 to the ground and then from the ground to satellite 2 220, it is sent directly from satellite 1 110 to satellite 2 220, with lower latency. Figure 2C An example procedure for AGW resource allocation in satellites using UE-Sat-UE optimization is illustrated. As shown in Figure 2C The operator needs to deploy on each satellite the intermediate user plane function (I-UPF) piggybacked on that satellite as well as the AGW, and use satellite resources to route media.

[0057] According to embodiments of the present disclosure, subscription information of the user equipment 110 (which indicates whether the user equipment 110 has subscribed to satellite access) can be used to enable or disable satellite access (e.g., UE-Sat-UE). For example, in the communication environment 100, the subscription information can be provided between the user equipment 110, the first network device 120, and the second device 130. Based on the subscription information, UE-Sat-UE media routing optimization can be allowed during an IMS call. Some example implementations are described below with reference to Figures 3 to 7

[0058] Figure 3 A signaling diagram for a registration procedure is illustrated according to some example embodiments of the present disclosure.

[0059] As​Figure 3 As shown in FIG. 3, a user equipment 110 (such as a UE) sends 302 a registration message to a first network equipment 120 (such as a P-CSCF). Correspondingly, the first network equipment 120 receives 304 the registration message from the user equipment 110. For example, after the first network equipment 120 has obtained IP connectivity, it can perform IMS registration.

[0060] In response to receiving the registration message from the user equipment 110, the first network equipment 120 forwards 306 the registration message to a second network equipment 130. After the second network equipment 130 receives 308 the registration message, the second network equipment 130 obtains 310 subscription information for the user equipment 110, which indicates whether the user equipment 110 has subscribed to satellite access.

[0061] In some example embodiments, the subscription information can be obtained from a third network equipment. For example, the third network equipment can comprise a home subscriber server (HSS). After the second network equipment 130 obtains the subscription information from the HSS, the second network equipment 130 can locally store or maintain the subscription information for future use. For example, during a next call setup procedure for the user equipment 110, the second network equipment 130 can obtain the locally stored subscription information and determine whether the user equipment 110 is allowed or not allowed for satellite access.

[0062] In some example embodiments, based on the subscription information, the second network equipment 130 can determine whether the user equipment 110 is allowed or not allowed for satellite access. Such a determination can be applied during a call setup procedure for the user equipment. For example, in some example embodiments, the user equipment 110 can send a first request to the first network equipment 120 to setup a call, and the first network equipment 120 can send 314 a second request to the second network equipment 130 to setup the call for the user equipment 110. The second request can include additional satellite access information for the user equipment 110. Based on the subscription information indicating whether the user equipment 110 has subscribed to satellite access, the second network equipment can determine whether the user equipment 110 is allowed or not allowed for satellite access. Then, the second network equipment 130 can send a third request to a remote network equipment to setup the call for the user equipment 110, the third request including or excluding the additional satellite access information based on the determination.

[0063] In some example embodiments, the additional satellite access information can be excluded based on a determination that the user equipment 110 is not allowed for satellite access. In another example embodiment, the additional satellite access information can be included based on a determination that the user equipment 110 is allowed for satellite access.

[0064] Since the second network device 130 has obtained the subscription information, when the second network device 130 receives the call request including the additional satellite access information (which can be carried in an added header, hence also referred to as additional header information) from the first network device 120, the second network device 130 can remove the additional header information. The additional satellite access information can include any information related to satellite access, such as satellite identity (ID) and access network information. In this way, the additional header information that has been added by the first network device 120 and forwarded to the second network device 130 on the caller party side will not be forwarded to the corresponding network device on the called party side. Thus, the signaling for NTN using UE-Sat-UE for IMS media can be reduced.

[0065] The second network device 130 can then send a second response to the first network device 120 for the second request, the second response excluding the additional satellite access information, to indicate that the terminating user equipment of the first call has not subscribed to satellite access. Based on the second response, the first network device 120 can determine that the satellite access is disabled for the first call.

[0066] An example procedure for removing the additional header information at the second network device 130 based on the subscription information will be described below with reference to Figure 4 described. In this example, the UE 410 is an example of the user equipment 110, the P-CSCF 420 is an example of the first network device 120, and the S-CSCF 430 is an example of the second network device 130.

[0067] As shown in Figure 4 At 401, the UE 410 can obtain an IP address from an evolved packet system (EPS) / 5G system (5GS) in an access network according to an IP connectivity access network (IP CAN) procedure over current standards. At 403, a service management function (SMF) 450 can obtain default policy and charging control (PCC) rules and associate them with the IP CAN. The policy control function (PCF) 470 can provide these rules according to current standards. At 405, using the IP address obtained in step 401, the UE 410 can perform an IMS registration. The session initiation protocol (SIP) message is IP routed to the P-CSCF 420 by the 5GS via a PDU session anchoring user plane function (PSA-UPF) on the ground. When the P-CSCF 420 receives the REGISTER message, it can interact with the PCF 470 to subscribe to signaling bearer state changes and satellite access information.

[0068] At 407, using the IP address in the Session Description Protocol (SDP) obtained in step 401, the UE 410 can initiate a SIP session. An INVITE request (as an example of a first request to establish a call) can be routed from the 5GS to the P-CSCF 420 in the home network. At 409, if the P-CSCF 420 determines that the UE 410 is under satellite access, it can include additional satellite access information, such as satellite ID and access network information. The determination can be based on the P-CSCF 420 subscription to the PCF 470. The PCF 470 can then obtain from the SMF 450 that the UE 410 is in satellite. At 411, the INVITE (as an example of a second request to establish a call) continues from the P-CSCF 420 to the S-CSCF 430 and onward. If the UE 410 is not subscribed to UE-Sat-UE, the S-CSCF 430 can remove the additional header information (as an example of additional satellite access information) included by the P-CSCF 420 based on the subscription information described in step 409 (during IMS registration). If the UE 410 has subscribed to allow UE-Sat-UE, the S-CSCF 430 can allow the additional header information to be included when contacting the remote S-CSCF / P-CSCF (not shown). At 413, the offer is received by the P-CSCF 420 from the far end. If an IMS-AGW on board a satellite is allocated for the far end UE (not shown), the P-CSCF 420 can receive additional satellite access information, such as satellite ID and access network information. Otherwise, the additional satellite access information can be removed, and thus the P-CSCF 420 can determine that UE-Sat-UE is disabled.

[0069] At 415, if the P-CSCF 420 determines the possibility of UE-Sat-UE communication based on the additional satellite access information received from the far end, the IMS-AGW on board a satellite resource allocation can continue. At 417, if the P-CSCF 420 decides to route media via satellite, resources in the IMS-AGW on board a satellite can be allocated and the offered SDP answer is changed accordingly. At 419, the P-CSCF 420 can provide session information to the PCF 470.

[0070] At 421, based on the IP address included in the session information, the PCF 470 can provide PCC rules to the SMF 450. At 423, based on the indication, the SMF 450 can insert an I-UPF on board a satellite, configure N6 of the I-UPF to point to the IMS-AGW on board a satellite, and configure N9 in the PSA-UPF and the I-UPF.

[0071] At 425, the PCSCF 420 can forward the Offer Response message to the originating endpoint (UE 410). At 427, the UE 410 can acknowledge receipt of the Offer Response and send a Response Confirmation to the P CSCF 420. The P CSCF 420 can forward this message to the S-CSCF 430. The P-CSCF 420 can include the modified SDP per the resource allocation in step 415. The terminating endpoint can respond to the originating endpoint with the acknowledgement. At 429, when the destination answers, the terminating endpoint can send a SIP 200-OK final response to the S-CSCF 430 / P-CSCF 420 along the signaling path to the originating endpoint. At 431, the IMS-AGW resources can be updated if the SDP has changed after receiving the modified SDP in step 427.

[0072] At 433, the P CSCF 420 can pass the 200-OK response back to the UE 410. The P CSCF 420 can indicate that the media stream authorized for this session will be enabled. At 435, the media exchanged between the UE 410 and the far-end UE can now be routed via the IMS AGW on-board the serving satellite, between the I-UPF on-board the serving satellite and the IMS-AGW on-board the satellite serving the far-end UE.

[0073] Still referring to Figure 3 After the second network equipment 130, the second network equipment 130 sends (320) to the first network equipment 120 subscription information of the user equipment 110, the subscription information indicating whether the user equipment 110 has subscribed to satellite access. Correspondingly, the first network equipment 120 receives (322) the subscription information of the user equipment 110.

[0074] Then, the first network equipment 120 sends (324) to the user equipment 110 an indication of whether the user equipment 110 has subscribed to satellite access. Correspondingly, the user equipment 110 receives (326) the indication from the first network equipment 120.

[0075] An example procedure for subscription information acquisition at IMS registration will be described below with reference to Figure 5

[0076] As Figure 5 ​As shown, at 501, after the UE 410 has obtained IP connectivity, the UE 410 can perform an IMS registration. The UE 410 can send a registration information flow to the proxy, which includes a public user identity, a private user identity, a home network domain name, a UE IP address, an instance identifier, a GRUU support indication. At 503, the P-CSCF 420 can forward the registration message to the S-CSCF 430, which can include a P-CSCF address / name, a public user identity, a private user identity, a P-CSCF network identifier, a UE IP address.

[0077] At 505, the S-CSCF 430 can send a Cx-Put / Cx-Pull to a home subscriber server (HSS) 590, which can include a public user identity, a private user identity, an S-CSCF name. At 507, the HSS 590 can store the S-CSCF name for this user and return an information flow Cx-Put Resp / Cx-Pull Resp (User Info) to the S-CSCF 430. The user info passed from the HSS 590 to the S-CSCF 430 can include an indication in the user's service profile whether the UE 410 has subscribed to the "UE-Sat-UE" call feature (as an example of subscription information).

[0078] At 509, the S-CSCF 430 can determine whether the UE 410 is allowed to make "UE-Sat-UE" calls based on the response from the HSS 590. At 511, if the UE 410 is allowed to make "UE-Sat-UE" calls, the S-CSCF 430 can send subscription information to the P-CSCF 420 in a 200 OK message to indicate that the UE 410 is allowed to make "UE-Sat-UE" calls. It should be understood that the communication between the P-CSCF 420 and the S-CSCF 430 can be via an interrogating call session control function (I-CSCF), which is not shown in the call flow. At 512, the P-CSCF 420 can store the home network contact information and an indication of whether "UE-Sat-UE" is allowed for the UE 410. At 513, the P-CSCF 420 can send subscription information (indication - UE-Sat-UE allowed / not allowed) to the UE 410 in an information flow 200 OK.

[0079] As described above, the second network device 130 is making the first network device 120 aware of the UE-Sat-UE applicability during IMS registration. The first network device 120 can make a decision whether to allow UE-Sat-UE during call setup based on the applicability information shared during IMS registration. Then, once a call is requested, the first network device 120 can directly look up whether the subscriber is allowed to use UE-Sat-UE and only in case the subscriber is allowed, additional satellite access information can be added in the header by the first network device 120. Thus, adding the header and forwarding the header can be completely saved.

[0080] Figure 6 FIG. 3 illustrates a signaling diagram for a subscription-based call setup procedure according to some example embodiments of the present disclosure.

[0081] As Figure 6 As shown in FIG. 3, the first network device 120 can create (302) a subscription for the user equipment 110. The subscription can be independent of satellite access information based on subscription information indicating that the user equipment has not subscribed to satellite access.

[0082] The user equipment 110 can send (304) a first request to the first network device 120 to establish a first call. Correspondingly, the first network device 120 can receive (306) the first request. In some example embodiments, the first request can indicate a preference for satellite access.

[0083] After the first network device 120 receives the first request, the first network device 120 can send (308) a second request to the second network device 130 to establish the first call for the user equipment 110, the second request including or excluding additional satellite access information based on subscription information indicating whether the user equipment has subscribed to satellite access. In some example embodiments, the first network device 120 can determine whether to enable satellite access based on the preference of the user equipment 110 indicated in the first request to establish the call. Correspondingly, the second network device 130 can receive (310) the second request.

[0084] In some example embodiments, the additional satellite access information can be excluded based on the subscription information indicating that the user equipment has not subscribed to satellite access. In another example embodiment, the additional satellite access information can be included based on the subscription information indicating that the user equipment has subscribed to satellite access. For example, if the first network device 120 determines that the user equipment 110 is under satellite access and determines whether the user is allowed to make a “UE-Sat-UE” call based on the user service profile, the first network device 120 can include additional satellite access information, such as a satellite ID and access network information. If the user equipment 110 is not subscribed to UE-Sat-UE optimization, the first network device 120 can not include the additional satellite access information.

[0085] The first network device 120 can then send (618) a first response to the first request to the user equipment 110, the first response indicating whether the satellite access is disabled for the call based on the subscription information indicating whether the user equipment has subscribed to satellite access. Correspondingly, the user equipment can receive (620) the first response to the first request.

[0086] In some example embodiments, the user equipment 110 can skip transmission of a request for a change of satellite during movement of the user equipment based on an indication that the user equipment 110 has not subscribed to satellite access. In an example, the request for a change of satellite can include a re-invite message (or “re-invite”).

[0087] During a satellite change or movement, a handover event at the UE can cause the UE to send a re-invite to request for a change of satellite. The P-CSCF can need this re-invite to re-allocate a new AGW in the target satellite and to inform other parties of the new AGW resource. It should be noted that AGW change does not occur in a terrestrial network or in a non-UE-Sat-UE call. This is a specific enhancement made in 3GPP standards for the UE-Sat-UE feature.

[0088] This re-invite is a special behavior because a normal IMS re-invite is triggered only when the IMS layer of the UE detects any IP-CAN change (e.g., a change in IP address due to an anchor UPF change or AGW reassignment of a new IP / port). In the case of UE-Sat-UE, the UE can not be generating a re-invite because of an IMS layer related trigger, but because of a lower layer indication that the serving satellite has changed (satellite ID).

[0089] If the UE is not participating in a UE-Sat-UE call, this re-invite can need to be restricted. Thus, the UE can need to be informed during call setup whether the call is routed via UE-Sat-UE media. Thus, UE-Sat-UE eligibility is sent to the UE during IMS registration to avoid re-invites. By skipping the re-invite message (as an example for a request to change satellites), signaling overhead can be reduced and resource utilization can be improved.

[0090] In some example embodiments, the first network device 120 can receive, from a third network device (not shown), a third request for establishing a second call terminated at the user equipment 110, the third request including additional satellite access information to indicate that an originating user equipment of the second call has subscribed to satellite access. Then, the first network device 120 can send, to the third network device, a third response for the third request, the third response including or excluding the additional satellite access information based on the subscription information indicating whether the user equipment 110 has subscribed to satellite access. For example, if the user equipment 110 has not subscribed to satellite access, the first network device 120 can remove the additional satellite access information even if the originating user equipment has subscribed to satellite access.

[0091] An example call setup procedure based on subscription information will be described below with reference to Figure 7 FIG. 6.

[0092] As Figure 7 shown in FIG. 7, at 701, the UE 410 can obtain an IP address from an EPS / 5GS in the access network according to an IP CAN procedure specified by current standards. At 703, the SMF 450 can obtain default PCC rules and associate them with this IP-CAN. The PCF can provide these rules according to current standards. At 705, using the IP address obtained in 701, the UE 410 can perform IMS registration. This SIP message is IP-routed by the 5GS to the P-CSCF 420 via the PSA-UPF on the ground. When the P-CSCF 420 receives the REGISTER message, it can interact with the PCF 470 to subscribe to signaling bearer state changes and satellite access information. The P-CSCF 420 can pick not to create a subscription related to satellite access information for UEs that are not subscribed to non-UE-Sat-UE.

[0093] At 707, using the IP address obtained in the SDP in step 701, the UE 410 can initiate the SIP session by sending a SIP INVITE message (as an example of a first request to establish a call). The SIP REGISTER message can additionally include an indication of preference for "UE-Sat-UE" calls (as an example for satellite access). The INVITE request can be routed from the 5GS to the P-CSCF 420. At 709, if the P-CSCF 420 determines that the UE 410 is under satellite access and determines whether the user is allowed to make "UE-Sat-UE" calls based on the user service profile, the P-CSCF 420 can include additional satellite access information, such as satellite ID and access network information, in the SIP INVITE message to the S-CSCF 430 (as an example of a second request to establish a call). This determination is based on a P-CSCF subscription to the PCF 470. The PCF 470 can then obtain the UE's presence in a satellite from the SMF 450. If the UE 410 is not subscribed to UE-Sat-UE optimization, the P-CSCF 420 can not include additional header information, such as satellite access information of satellite ID.

[0094] At 711, the INVITE continues from the P-CSCF 420 to the S-CSCF 430 and continues. At 713, a provision (as an example of a second response for the second request) can be received by the P-CSCF 420 from the far-end UE (not shown). If an IMS-AGW on-boarded on a satellite is allocated for the far-end UE, the P-CSCF 420 can receive additional satellite access information, such as satellite ID and access network information. If the near-end UE is subscribed to UE-Sat-UE, while the far-end UE is not subscribed to UE-Sat-UE, the response from the far-end can not contain additional satellite access information, such as satellite ID and access network information (same behavior as described in steps 705-709).

[0095] At 715, if the P-CSCF 420 determines the possibility of UE-Sat-UE communication based on the satellite access information received from the far-end UE, the P-CSCF 420 can continue the IMS-AGW resource allocation on-boarded on a satellite. Alternatively, the P-CSCF 420 can determine at this stage whether the UE is allowed to make "UE-Sat-UE" calls. At 717, if the P-CSCF 420 decides to route the media via a satellite, the P-CSCF 420 can allocate resources in the IMS-AGW on-boarded on a satellite and accordingly alter the provisioned SDP answer. At 719, the P-CSCF 420 can provide session information to the PCF 470.

[0096] At 721, based on the IP address included in the session information, the PCF 470 can provide PCC rules to the SMF 450. At 723, based on the indication, the SMF 450 can insert a satellite-onboard I-UPF, configure the N6 of the I-UPF to point to a satellite-onboard IMS-AGW, and configure N9 in the PSA-UPF and the I-UPF. At 725, the P-CSCF 420 can forward a provisioning response message (as an example of a first response to the first request) to the originating endpoint and optionally include an indication of whether a UE-Sat-UE call is possible. This is to ensure that even if the UE 410 is marked as a subscription UE-Sat-UE during registration, the UE 410 does not attempt to re-invite after a change of satellite.

[0097] At 727, the UE 410 can acknowledge receipt of the provisioning response and send a response acknowledgement to the P-CSCF 420. The P-CSCF 420 can forward this message to the S-CSCF 430. The P-CSCF 420 can include the modified SDP as per the resource allocation in step 715. The terminating endpoint can respond to the originating endpoint with an acknowledgement message. At 729, when the destination answers, the terminating endpoint can send a SIP 200-OK final response to the S-CSCF 430 / P-CSCF 420 along the signaling path to the originating endpoint.

[0098] At 731, if the SDP has changed after receiving the modified SDP in step 727, the IMS-AGW resources can be updated. At 733, the PCSCF can pass a 200-OK response back to the UE 410. The PCSCF 420 can indicate that the media stream authorized for this session can be enabled. At 735, the media exchanged between the UE 410 and the remote UE can now be routed via the IMS AGW onboard serving the satellite, between the I-UPF onboard serving the satellite and the IMS-AGW onboard serving the satellite of the remote UE.

[0099] Figure 8 A flowchart illustrating an example method 800 implemented at a user equipment is shown, in accordance with some example embodiments of the present disclosure. For purposes of discussion, the method 800 will be described from the perspective of the user equipment 110 in Figure 1 FIG. 1.

[0100] At block 810, the user equipment 110 sends a registration message to a first network device.

[0101] At block 820, the user equipment 110 receives an indication from the first network device whether the user equipment has subscribed to satellite access.

[0102] In some example embodiments, user equipment 110 may send a first request to a first network device to establish a first call; and may receive a first response from the first network device in response to the first request, the first response indicating whether satellite access for the call is disabled.

[0103] In some example implementations, the first request may indicate a preference for satellite access.

[0104] In some example embodiments, the first network device may include proxy call session control functionality.

[0105] In some exemplary embodiments, the user equipment may skip the transmission of a request to change satellites during the user equipment's mobility period, based on an indication that the user equipment has not yet subscribed to satellite access.

[0106] Figure 9 A flowchart of an example method 900 implemented at a first network device according to some exemplary embodiments of the present disclosure is shown. For discussion purposes, method 900 will be discussed from... Figure 1 The angle of the first network device 120 in the diagram is described.

[0107] At box 910, the first network device 120 receives a registration message from the user equipment.

[0108] At box 920, in response to receiving a registration message from the user equipment, the first network device 120 forwards the registration message to the second network device.

[0109] At box 930, the first network device 120 receives subscription information from the second network device, which indicates whether the user equipment has subscribed to satellite access.

[0110] In some example embodiments, the first network device 120 may send an indication to the user equipment whether the user equipment has subscribed to satellite access.

[0111] In some example embodiments, the first network device 120 may create a subscription for a user device that is based on subscription information indicating that the user device has not yet subscribed to satellite access, and is unrelated to satellite access information.

[0112] In some example embodiments, a first network device 120 may receive a first request from a user equipment to establish a first call; and may send a second request to a second network device to establish the first call for the user equipment, the second request including or excluding additional satellite access information based on subscription information indicating whether the user equipment has subscribed to satellite access.

[0113] In some exemplary embodiments, the first request may indicate a preference for satellite access.

[0114] In some example embodiments, the first network device 120 can send, to the user equipment, a first response to the first request, the first response indicating whether satellite access is disabled for the call based on the subscription information indicating whether the user equipment has subscribed to satellite access.

[0115] In some example embodiments, the additional satellite access information can be excluded based on the subscription information indicating that the user equipment has not subscribed to satellite access.

[0116] In some example embodiments, the additional satellite access information can be included based on the subscription information indicating that the user equipment has subscribed to satellite access.

[0117] In some example embodiments, the first network device 120 can receive, from the second network device, a second response to the second request, the second response excluding the additional satellite access information to indicate that the terminating user equipment of the first call has not subscribed to satellite access; and determine, based on the second response, that satellite access is disabled for the first call.

[0118] In some example embodiments, the first network device 120 can receive, from a third network device, a third request for establishing a second call terminated at the user equipment, the third request including the additional satellite access information to indicate that an originating user equipment of the second call has subscribed to satellite access; and send, to the third network device, a third response to the third request, the third response including or excluding the additional satellite access information based on the subscription information indicating whether the user equipment has subscribed to satellite access.

[0119] In some example embodiments, the first network device 120 can comprise a proxy call session control function, and the second network device can comprise a serving call session control function.

[0120] Figure 10 A flowchart illustrating an example method 1000 implemented at a second network device according to some example embodiments of the present disclosure is shown. For purposes of discussion, the method 1000 will be described from the perspective of the second network device 130 in Figure 1

[0121] At block 1010, the second network device 130 receives, from a first network device, a registration message of a user equipment.

[0122] At block 1020, the second network device 130 obtains subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0123] ​In some example embodiments, the second network device 130 can receive, from the first network device, a second request to establish a call for the user equipment, the second request including additional satellite access information for the user equipment; and can send, to the remote network device, a third request to establish a call for the user equipment, the third request including or excluding the additional satellite access information based on the determination.

[0124] In some example embodiments, the additional satellite access information can be excluded based on a determination that the user equipment is not allowed for satellite access.

[0125] In some example embodiments, the additional satellite access information can be included based on a determination that the user equipment is allowed for satellite access.

[0126] In some example embodiments, the second network device 130 can send, to the first network device, subscription information for the user equipment to indicate whether the user equipment has subscribed to satellite access.

[0127] In some example embodiments, the subscription information can be obtained from a third network device.

[0128] In some example embodiments, the third network device can comprise a home subscriber server.

[0129] In some example embodiments, the first network device can comprise a proxy call session control function, and the second network device 130 can comprise a serving call session control function.

[0130] In some example embodiments, a user equipment (e.g., the user equipment 110 in Figure 1 ) capable of performing any of the method 800 can include means for performing the corresponding operations of the method 800. The means can be implemented in any suitable form. For example, the means can be implemented in the form of circuitry or software modules. The first apparatus can be implemented as the user equipment 110 in Figure 1 , or included in the user equipment 110 in Figure 1 .

[0131] In some example embodiments, the user equipment comprises: means for sending, to a first network device, a registration message; and means for receiving, from the first network device, an indication of whether the user equipment has subscribed to satellite access.

[0132] In some example embodiments, the user equipment further comprises: means for sending, to the first network device, a first request to establish a first call; and means for receiving, from the first network device, a first response to the first request, the first response indicating whether satellite access is disabled for the call.

[0133] In some example embodiments, the first request can indicate a preference for satellite access.

[0134] In some example embodiments, the first network device can comprise a proxy call session control function.

[0135] In some example embodiments, the user equipment further comprises means for skipping transmission of the request for changing the satellite during user equipment mobility based on the indication that the user equipment has not subscribed to satellite access.

[0136] In some example embodiments, a first network device (e.g., the first network device 120 in Figure 1 may comprise means for performing the corresponding operations of the method 900. The means can be implemented in any suitable form. For example, the means can be implemented in the form of circuitry or software modules. The second apparatus can be implemented as the first network device 120 in Figure 1 or be included in the first network device 120 in Figure 1 .

[0137] In some example embodiments, the first network device comprises means for receiving a registration message from the user equipment; means for forwarding the registration message to a second network device in response to receiving the registration message from the user equipment; and means for receiving subscription information for the user equipment from the second network device, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0138] In some example embodiments, the first network device further comprises means for sending an indication to the user equipment of whether the user equipment has subscribed to satellite access.

[0139] In some example embodiments, the first network device further comprises means for creating a subscription for the user equipment, the subscription being independent of satellite access information based on the subscription information indicating that the user equipment has not subscribed to satellite access.

[0140] In some example embodiments, the first network device further comprises means for receiving a first request from the user equipment to establish a first call; and means for sending a second request to a second network device to establish the first call for the user equipment, the second request including or excluding additional satellite access information based on the subscription information indicating whether the user equipment has subscribed to satellite access.

[0141] In some example embodiments, the first request can indicate a preference for satellite access.

[0142] In some example embodiments, the first network device further includes means for sending, to the user equipment, a first response to the first request, the first response including or excluding the additional satellite access information based on subscription information indicating whether the user equipment has subscribed to satellite access.

[0143] In some example embodiments, the additional satellite access information can be excluded based on the subscription information indicating that the user equipment has not subscribed to satellite access.

[0144] In some example embodiments, the additional satellite access information can be included based on the subscription information indicating that the user equipment has subscribed to satellite access.

[0145] In some example embodiments, the first network device further includes means for receiving, from a second network device, a second response to a second request, the second response excluding the additional satellite access information to indicate that a terminating user equipment of the first call has not subscribed to satellite access, and means for determining that satellite access is disabled for the first call based on the second response.

[0146] In some example embodiments, the first network device further includes means for receiving, from a third network device, a third request for establishing a second call terminated at the user equipment, the third request including the additional satellite access information to indicate that an originating user equipment of the second call has subscribed to satellite access, and means for sending, to the third network device, a third response to the third request, the third response including or excluding the additional satellite access information based on subscription information indicating whether the user equipment has subscribed to satellite access.

[0147] In some example embodiments, the first network device can include a proxy call session control function, and the second network device can include a serving call session control function.

[0148] In some example embodiments, a second network device (e.g., the second network device 130 in Figure 1 may include means for performing the corresponding operations of the method 1000. The means can be implemented in any suitable form. For example, the means can be implemented in circuitry or software modules. The third apparatus can be implemented as Figure 1 the second network device 130 in Figure 1 or included in the second network device 130 in

[0149] In some example embodiments, the second network device includes means for receiving, from a first network device, a registration message of a user equipment, and means for obtaining subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

[0150] In some example embodiments, the second network device further comprises: means for receiving, from the first network device, a second request to establish a call for the user equipment, the second request including additional satellite access information for the user equipment; and means for sending, to the remote network device, a third request to establish a call for the user equipment, the third request including or excluding the additional satellite access information based on the determination.

[0151] In some example embodiments, the additional satellite access information can be excluded based on a determination that the user equipment is not allowed for satellite access.

[0152] In some example embodiments, the additional satellite access information can be included based on a determination that the user equipment is allowed for satellite access.

[0153] In some example embodiments, the second network device comprises: means for sending, to the first network device, subscription information for the user equipment to indicate whether the user equipment has subscribed to satellite access.

[0154] In some example embodiments, the subscription information can be obtained from a third network device.

[0155] In some example embodiments, the third network device can comprise a home subscriber server.

[0156] In some example embodiments, the first network device can comprise a proxy call session control function, and the second network device can comprise a serving call session control function.

[0157] Figure 11 is a simplified block diagram of a device 1100 suitable for implementing example embodiments of the present disclosure. The device 1100 can be provided to implement a communication device, for example, a user equipment 110, a first network device 120, or a second network device 130, as shown in Figure 1 FIG. 1. As shown, the device 1100 includes one or more processors 1110, one or more memories 1120 coupled to the processor(s) 1110, and one or more communication modules 1140 coupled to the processor(s) 1110.

[0158] The communication module 1140 is for bidirectional communication. The communication module 1140 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface can represent any interface that is needed to communicate with other network elements. In some example embodiments, the communication module 1140 can include at least one antenna.

[0159] The processor 1110 can be of any type such as, but not limited to: a central processing unit (CPU), a semiconductor-based microprocessor, a microprocessor that is based on a multi-core processor architecture, a macroprocessor, a coordinated field programmable gate array (FPGA), or any combination thereof. The device 1100 can have multiple processors 1110, such as a master integrated circuit chip that is in communication with a secondary integrated circuit chip, where the secondary integrated circuit chip is utilized to implement one or more aspects of the functionality of the device 1100.

[0160] The memory 1120 can include one or more non-transitory memories and one or more volatile memories. Examples of non-transitory memories include, but are not limited to: read only memories (ROM), electrically programmable read only memories (EPROM), flash memories, hard disks, compact disks (CDs), digital video disks (DVDs), optical disks, laser disks, and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to: random access memories (RAM) 1122 and other volatile memories that do not maintain data bits when power is off.

[0161] The computer program 1130 includes computer executable instructions that are executed by the associated processor 1110. The instructions of the program 1130 can include instructions for performing the operations / acts of some example embodiments of the present disclosure. The program 1130 can be stored in a memory (e.g., ROM 1124). The processor 1110 can perform any suitable action and processing by loading a program 1130 into the RAM 1122.

[0162] Example embodiments of the present disclosure can be implemented with the aid of the program 1130, such that the device 1100 can perform any processes of the present disclosure, as discussed with reference to Figures 3 to 7 Example embodiments of the present disclosure can also be implemented by means of hardware or by means of a combination of software and hardware.

[0163] In some example embodiments, the program 1130 can be tangibly embodied in a computer readable medium, which can be included in the device 1100 (such as in the memory 1120) or in another storage device that is accessible by the device 1100. The device 1100 can load the program 1130 from the computer readable medium into the RAM 1122 for execution. In some example embodiments, the computer readable medium can include any type of non-transitory storage medium, such as a ROM, an EPROM, a flash memory, a hard disk, a CD-ROM, a DVD, and the like. As used herein, the term "non-transitory" is merely an art-accepted term to refer to the medium itself (i.e., tangible, as opposed to a signal), and not a limitation on the data storage durability (e.g., RAM vs. ROM).

[0164] Figure 12An example of a computer readable medium 1200 is shown, which can be in the form of a CD, DVD, or other optical storage disk. The computer readable medium 1200 has stored thereon the program 1130.

[0165] In general, the various embodiments of the present disclosure can be implemented in hardware or special-purpose circuits, software, logic or any combination thereof. Some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software which can be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or other diagrams, it will be understood that any

[0166] Some example embodiments of the present disclosure also provide at least one computer program product which is tangibly stored on a machine-readable medium, such as a non-transitory machine-readable medium. The computer program product includes instructions that, when executed by a device (such as a target physical or virtual processor), perform any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules can be combined or split between program modules as desired in various embodiments. Machine executable instructions for program modules can be executed within the same device or in a different device with respect to other machine executable instructions. In a distributed device, program modules can be located in both local and remote memory storage media.

[0167] Program code for carrying out methods of the present disclosure can be written in any combination of one or more programming languages. The program code can be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the program code, when executed by the processor or controller, causes the machine to perform the functions / acts specified in the flowcharts and / or block diagrams. The program code can execute entirely on a machine, partly on a machine, as a stand-alone software package, partly on a machine and partly on a remote machine or entirely on a remote machine or server.

[0168] In the context of the present disclosure, computer program code or related data can be carried by any suitable carrier and means to enable a device, apparatus, or processor to execute the various processes and operations described above. Examples of carriers include signals, computer readable media, etc.

[0169] The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. It can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0170] Moreover, while operations are depicted in a particular order, this should not be understood as requiring the operations to be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing can be advantageous. Likewise, while a number of specific implementation details are included for the purpose of providing a thorough description of certain embodiments, these details are not intended to limit the scope of the disclosure, but rather are considered as descriptive form of implementing specific embodiments. Descriptions of one or more embodiments in the context of separate embodiments can also be combined with one another in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments or in any suitable sub-combination.

[0171] Although the present disclosure has been described using specific language, it is to be understood that the disclosure defined in the accompanying claims should not be limited to the specific details described above. Rather, the specific features of the disclosure are disclosed as examples of one way of implementing the claims.

Claims

1. A user equipment, comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions, when executed by the at least one processor, cause the user equipment to at least: Send a registration message to the first network device; as well as Receive an indication from the first network device as to whether the user equipment has subscribed to satellite access.

2. The user equipment of claim 1, wherein the instructions, when executed by the at least one processor, further cause the user equipment to: Send a first request to the first network device to establish a first call; and Receive a first response from the first network device in response to the first request, the first response indicating whether satellite access is disabled for the call.

3. The user equipment of claim 2, wherein the first request indicates a preference for the satellite access.

4. The user equipment according to any one of claims 1 to 3, wherein the first network device includes a proxy call session control function.

5. The user equipment according to any one of claims 1 to 4, wherein the instructions, when executed by the at least one processor, further cause the user equipment to: Based on the indication that the user equipment has not yet subscribed to the satellite access, the transmission of the request to change satellites is skipped during the user equipment's movement.

6. A first network device, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the first network device to at least: Receive registration messages from user equipment; In response to receiving the registration message from the user equipment, the registration message is forwarded to the second network device; as well as The user equipment receives subscription information from the second network device, the subscription information indicating whether the user equipment has subscribed to satellite access.

7. The first network device of claim 6, wherein the instructions, when executed by the at least one processor, further cause the first network device to: Send an indication to the user equipment whether the user equipment has subscribed to the satellite access.

8. The first network device according to claim 6 or 7, wherein the instructions, when executed by the at least one processor, further cause the first network device to: A subscription is created for the user equipment, the subscription being independent of the satellite access information and based on the subscription information indicating that the user equipment has not yet subscribed to the satellite access.

9. The first network device according to any one of claims 6 to 8, wherein the instructions, when executed by the at least one processor, further cause the first network device to perform: Receive a first request from the user equipment to establish a first call; and A second request is sent to the second network device to establish the first call for the user equipment. The second request includes or excludes additional satellite access information based on the subscription information indicating whether the user equipment has subscribed to the satellite access.

10. The first network device of claim 9, wherein the first request indicates a preference for the satellite access.

11. The first network device according to claim 9 or 10, wherein the instructions, when executed by the at least one processor, further cause the first network device to: Send a first response to the first request to the user equipment, the first response indicating whether the satellite access is disabled for the call based on the subscription information indicating whether the user equipment has subscribed to the satellite access.

12. The first network device according to any one of claims 9 to 11, wherein the additional satellite access information is excluded based on the subscription information indicating that the user equipment has not yet subscribed to the satellite access.

13. The first network device according to any one of claims 9 to 12, wherein the additional satellite access information is included based on the subscription information indicating that the user equipment has subscribed to the satellite access.

14. The first network device of claim 13, wherein the instructions, when executed by the at least one processor, further cause the first network device to: Receive a second response from the second network device in response to the second request, the second response excluding the additional satellite access information to indicate that the user equipment terminating the first call has not subscribed to the satellite access; and Based on the second response, it is determined that the satellite access for the first call is disabled.

15. The first network device according to any one of claims 6 to 8, wherein the instructions, when executed by the at least one processor, further cause the first network device to perform: A third request is received from a third network device, the third request being used to establish a second call terminated at the user equipment, the third request including additional satellite access information to indicate that the originating user equipment of the second call has subscribed to the satellite access; and A third response to the third request is sent to the third network device, the third response including or excluding the additional satellite access information based on indicating whether the user equipment has subscribed to the subscription information for the satellite access.

16. The first network device according to any one of claims 6 to 15, wherein the first network device includes a proxy call session control function, and the second network device includes a service call session control function.

17. A second network device, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the second network device to at least: Receive user device registration messages from the first network device; as well as Obtain the subscription information of the user equipment, which indicates whether the user equipment has subscribed to satellite access.

18. The second network device of claim 17, wherein the instructions, when executed by the at least one processor, further cause the second network device to perform: Receive a second request from the first network device, the second request being used to establish a call for the user equipment, the second request including additional satellite access information of the user equipment; and A third request is sent to a remote network device to establish the call for the user equipment, the third request including or excluding the additional satellite access information based on a determination.

19. The second network device of claim 18, wherein the additional satellite access information is excluded based on determining that the user equipment is not permitted for the satellite access.

20. The second network device of claim 19, wherein the additional satellite access information is included based on determining that the user equipment is permitted for the satellite access.

21. The second network device of claim 17, wherein the instructions, when executed by the at least one processor, further cause the second network device to: The user equipment's subscription information is sent to the first network device to indicate whether the user equipment has subscribed to the satellite access.

22. The second network device according to any one of claims 17 to 21, wherein the subscription information is obtained from the third network device.

23. The second network device of claim 22, wherein the third network device includes a home subscriber server.

24. The second network device according to any one of claims 17 to 23, wherein the first network device includes a proxy call session control function, and the second network device includes a service call session control function.

25. A method comprising: Send a registration message to the first network device; as well as The first network device receives an indication of whether the user equipment has subscribed to the satellite access.

26. A method comprising: Receive registration messages from user equipment; In response to receiving the registration message from the user equipment, the registration message is forwarded to the second network device; as well as The user equipment receives subscription information from the second network device, the subscription information indicating whether the user equipment has subscribed to satellite access.

27. A method comprising: Receive user device registration messages from the first network device; as well as Obtain the subscription information of the user equipment, which indicates whether the user equipment has subscribed to satellite access.

28. A user equipment, comprising: Components used to send registration messages to the first network device; as well as A component for receiving an indication from the first network device as to whether the user equipment has subscribed to the satellite access.

29. A first network device, comprising: Components used to receive registration messages from user equipment; Components for forwarding the registration message to a second network device in response to receiving the registration message from the user equipment; as well as A component for receiving subscription information of the user equipment from the second network device, the subscription information indicating whether the user equipment has subscribed to satellite access.

30. A second device, comprising: Components used to receive registration messages from user equipment from a first network device; as well as A component for obtaining subscription information of the user equipment, the subscription information indicating whether the user equipment has subscribed to satellite access.

31. A computer-readable medium comprising instructions stored thereon, the instructions being configured to cause a device to perform at least the method of claim 25, the method of claim 26, or the method of claim 27.

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