Method and apparatus for non-terrestrial network storage and forwarding procedure in wireless communication system

Abstract

Methods, systems, and devices are provided for non-terrestrial network storage and forwarding procedures in a wireless communication system wherein a method of a first network node includes receiving a transmission from a user equipment, and determining to respond to the transmission of the user equipment based on the feed link of the first network node being unavailable and the service associated with the transmission being a short message service.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 544,064, filed on October 13, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates generally to wireless communication networks, and more particularly, to methods and apparatus for non-terrestrial network (NTN) store and forward procedures in wireless communication systems. Background Art

[0003] With the rapid growth of the demand for transmitting large amounts of data to and from mobile communication devices, traditional mobile voice communication networks have evolved into networks that communicate using Internet Protocol (IP) packets. This IP packet communication can provide IP-bearing voice, multimedia, multicast and on-demand communication services to users of mobile communication devices.

[0004] An exemplary network structure is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The E-UTRAN system can provide high data throughput to implement the above-mentioned IP-bearing voice and multimedia services. Currently, the 3GPP standards organization is discussing new radio technologies for the next generation (e.g., 5G). Therefore, changes to the current body of 3GPP standards are currently being submitted and considered to evolve and complete the 3GPP standards. Summary of the invention

[0005] A method, system and apparatus are provided for a non-terrestrial network (NTN) store and forward (S&F) procedure in a wireless communication system, wherein the procedure can operate well in an S&F mode.

[0006] In various embodiments, a method of a first network node includes receiving a transmission from a user equipment (UE) and determining to respond to the transmission to the UE based on a feeder link of the first network node being unavailable and a service associated with the transmission being a short message service (SMS). BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A diagram showing a wireless communication system according to an embodiment of the present invention is shown.

[0008] Figure 2is a block diagram of a transmitter system (also referred to as an access network) and a receiver system (also referred to as a user equipment or UE) according to an embodiment of the present invention.

[0009] Figure 3 is a functional block diagram of a communication system according to an embodiment of the present invention.

[0010] Figure 4 According to an embodiment of the present invention Figure 3 Functional block diagram of the program code.

[0011] Figure 5 It is in 3GPP TR 38.821 V16.0.0 Figure 4 .1-1: Reproduction of a typical scenario for non-terrestrial networks based on transparent payload.

[0012] Figure 6 It is in 3GPP TR 38.821 V16.0.0 Figure 4 .1-2: Reproduction of a typical scenario for non-terrestrial networks based on regenerative payload.

[0013] Figure 7 It is in 3GPP TR 38.821 V16.0.0 Figure 5 .2.1-1: Reproduction of regenerated satellite without ISL, gNB processed payload.

[0014] Figure 8 It is in 3GPP TR 38.821 V16.0.0 Figure 5 .2.1-2: Reproduction of regenerated satellite with ISL, gNB processed payload.

[0015] Fig. 9 It is in 3GPP TR 38.821 V16.0.0 Figure 5 .2.2-1: Re-emergence of NG-RAN with satellite-based regeneration based on gNB-DU.

[0016] Fig.10 It is a reproduction of Figure A-1 in 3GPP TR 22.865 V2.0.0: Illustration of “Normal / Default Operation” and “S&F Operation” modes in a 5G system with satellite access.

[0017] Fig.11 It is in 3GPP TR 22.865 V2.0.0 Figure 5 .4.3-1: Re-emergence of animal tracking in remote areas.

[0018] Fig.12is a reproduction of the diagram of a possible call flow for an intermittent feeder link in 3GPP RWS-230178.

[0019] Fig.13 It is in 3GPP TS 23.501 V18.1.0 Figure 4 .2.3-1: Re-enactment of the non-roaming 5G system architecture.

[0020] Fig.14 is a diagram showing an example of an NTN network according to an embodiment of the present invention.

[0021] Fig.15 is an example diagram of UP data flow in S&F mode according to an embodiment of the present invention.

[0022] Fig.16 is an example diagram of a procedure in a normal mode according to an embodiment of the present invention.

[0023] Fig.17 is an example diagram of a failure of a program / transfer according to an embodiment of the present invention.

[0024] Fig.18 is an example diagram showing that a UE may initiate a first procedure based on whether the UE is in an S&F mode and / or whether a feeder link is available according to an embodiment of the present invention.

[0025] Fig.19 is an example diagram showing that a network node may receive a request for a first procedure from a UE according to an embodiment of the present invention.

[0026] Fig. 20 is an example diagram showing that a network node may receive a request for a first procedure from a UE and may suspend the request if the network node is in an S&F mode according to an embodiment of the present invention.

[0027] Fig.21 is an example diagram showing that a network node may receive a request for a first procedure from a UE and the network node (eg, a satellite NW) may transmit (or restore, or forward, or relay) the request to a terrestrial NW according to an embodiment of the present invention.

[0028] Fig. 22 1 is an example diagram showing that a configuration (or pre-configuration) regarding a first program may be provided to a first network node (eg, a satellite NW) by, for example, a second network node (eg, a terrestrial NW) according to an embodiment of the present invention.

[0029] Fig.23 is an example diagram illustrating that a first network node may respond to a transmission based on an operation mode (eg, whether the first network node is in S&F mode) according to an embodiment of the present invention.

[0030] Fig.24 is an example diagram illustrating that a first network node may (determine whether to) respond to a transmission based on an operation mode (eg, whether the first network node is in a normal mode) according to an embodiment of the present invention.

[0031] Fig.25 is a flow chart of a method of a UE according to an embodiment of the present invention, the method comprising receiving an indication of operating in an S&F mode, and determining whether to initiate a procedure based on whether the UE is operating in the S&F mode.

[0032] Fig.26 is a flow chart of a method of a first network node according to an embodiment of the present invention, the method comprising transmitting an indication of operating in S&F mode, receiving a request for a procedure from a UE, and determining whether to reject the request based on whether the first network node is operating in S&F mode.

[0033] Fig. 27 is a flow chart of a method of a first network node according to an embodiment of the present invention, the method comprising transmitting an indication of operating in S&F mode, receiving a request for a procedure from a UE, and determining whether to store the request based on whether the first network node is operating in S&F mode.

[0034] Fig.28 is a flow chart of a method of a first network node according to an embodiment of the present invention, the method comprising transmitting an indication of operating in S&F mode, receiving a request for a procedure from a UE, and determining whether to respond to the request based on whether the first network node is operating in S&F mode.

[0035] Fig.29 is a flow chart of a method of a first network node according to an embodiment of the invention, the method comprising receiving a transmission from a UE, and determining a response to the transmission to the UE based on a feeder link of the first network node being unavailable and a service associated with the transmission being SMS. DETAILED DESCRIPTION

[0036] The present invention described herein may be applied to or implemented in the exemplary wireless communication systems and devices described below. In addition, the present invention is mainly described in the context of the 3GPP architecture reference model. However, it should be understood that with the help of the disclosed information, those skilled in the art can easily adapt and use and implement aspects of the present invention in the 3GPP2 network architecture as well as other network architectures.

[0037] The exemplary wireless communication systems and devices described below employ wireless communication systems that support broadcast services. Wireless communication systems are widely deployed to provide various types of communications, such as voice, data, etc. These systems can be based on code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), 3GPP Long Term Evolution (LTE) radio access, 3GPP Long Term Evolution Advanced (LTE-A) radio access, 3GPP2 Ultra Mobile Broadband (UMB), WiMax, 3GPP New Radio (NR), or some other modulation technology.

[0038] In particular, the exemplary wireless communication systems and devices described below may be designed to support one or more standards, such as those provided by a consortium named "3rd Generation Partnership Project" referred to herein as 3GPP, including: [1] 3GPP TR 38.821 V16.0.0, "Solutions for NR Support of Non-Terrestrial Networks (NTN)"; [2] 3GPP TR 22.865 V2.0.0, "Study of Satellite Access Phase 3 (Release 19)"; [3] 3GPP TS 23.501 V18.1.0, "System Architecture for 5G System (5GS)"; and [4] 3GPP RWS-230178, "NR and IoT NTN". The standards and documents listed above are hereby expressly and completely incorporated herein by reference in their entirety.

[0039] Figure 1 1 shows a multiple access wireless communication system according to an embodiment of the present invention. An access network 100 (AN) includes multiple antenna groups, one including 104 and 106, another including 108 and 110, and another including 112 and 114. Figure 1, only two antennas are shown for each antenna group, however, more or fewer antennas may be utilized for each antenna group. Access terminal (AT) 116 communicates with antennas 112 and 114, where antennas 112 and 114 transmit information to access terminal 116 via forward link 120 and receive information from AT 116 via reverse link 118. AT 122 communicates with antennas 106 and 108, where antennas 106 and 108 transmit information to AT 122 via forward link 126 and receive information from AT 122 via reverse link 124. In an FDD system, communication links 118, 120, 124, and 126 may use different frequencies for communication. For example, forward link 120 may use a different frequency than the frequency used by reverse link 118.

[0040] Each group of antennas and / or the area in which they are designed to communicate is often referred to as a sector of the access network. In an embodiment, the antenna groups are each designed to communicate with access terminals in a sector of the area covered by the access network 100.

[0041] In communicating via forward links 120 and 126, the transmit antennas of access network 100 may utilize beamforming in order to improve the signal-to-noise ratio of the forward links for the different access terminals 116 and 122. Additionally, an access network transmitting to access terminals randomly dispersed throughout its coverage area using beamforming may cause less interference to access terminals in neighboring cells than an access network transmitting to all of its access terminals via a single antenna.

[0042] AN can be a fixed station or base station for communicating with a terminal and can also be referred to as an access point, Node B, base station, enhanced base station, eNodeB or some other term. AT can also be referred to as User Equipment (UE), a wireless communication device, a terminal, an access terminal or some other term.

[0043] Figure 2 2 is a simplified block diagram of an embodiment of a transmitter system 210 (also referred to as an access network) and a receiver system 250 (also referred to as an access terminal (AT) or user equipment (UE)) in a MIMO system 200. At the transmitter system 210, traffic data for a number of data streams is provided from a data source 212 to a transmit (TX) data processor 214.

[0044] In one embodiment, each data stream is transmitted through a respective transmit antenna.TX data processor 214 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

[0045] The decoded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and decoded data for each data stream are then modulated (e.g., symbol mapped) based on a specific modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected for each data stream to provide modulation symbols. Instructions executed by processor 230 may determine the data rate, coding, and modulation for each data stream. Memory 232 is coupled to processor 230.

[0046] The modulation symbols for all data streams are then provided to a TX MIMO processor 220, which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 220 then provides NT modulation symbol streams to NT transmitters (TMTR) 222a through 222t. In certain embodiments, TX MIMO processor 220 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

[0047] Each transmitter 222 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and up-converts) the analog signals to provide a modulated signal suitable for transmission via the MIMO channel. NT modulated signals from transmitters 222a through 222t are then transmitted from NT antennas 224a through 224t, respectively.

[0048] At receiver system 250, the transmitted modulated signals are received by NR antennas 252a through 252r and the received signal from each antenna 252 is provided to a respective receiver (RCVR) 254a through 254r. Each receiver 254 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream.

[0049] RX data processor 260 then extracts the N R The receiver 254 receives and processes N R received symbol streams to provide N T The RX data processor 260 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by the RX data processor 260 is complementary to the processing performed by the TX MIMO processor 220 and the TX data processor 214 at the transmitter system 210.

[0050] Processor 270 periodically determines which pre-coding matrix to use (discussed below). Processor 270 formulates a reverse link message comprising a matrix index portion and a rank value portion.

[0051] The reverse link message may include various types of information regarding the communication link and / or the received data stream. The reverse link message is then processed by the TX data processor 238 (which also receives traffic data for a number of data streams from the data source 236), modulated by the modulator 280, conditioned by the transmitters 254a to 254r, and transmitted back to the transmitter system 210.

[0052] At the transmitter system 210, the modulated signal from the receiver system 250 is received by the antenna 224, conditioned by the receiver 222, demodulated by the demodulator 240, and processed by the RX data processor 242 to extract the reverse link message transmitted by the receiver system 250. The processor 230 then determines which precoding matrix to use to determine the beamforming weights and then processes the extracted message.

[0053] The memory 232 may be used to temporarily store some buffer / calculated data from 240 or 242 via the processor 230, store some buffer data from 212, or store some specific program codes. Also, the memory 272 may be used to temporarily store some buffer / calculated data from 260 via the processor 270, store some buffer data from 236, or store some specific program codes.

[0054] Go to Figure 3 , this figure shows an alternative simplified functional block diagram of a communication device according to one embodiment of the present invention. Figure 3 As shown, the communication device 300 in the wireless communication system can be used to implement Figure 1 UE (or AT) 116 and 122 in the communication device 300, and the wireless communication system is preferably an NR system. The communication device 300 may include an input device 302, an output device 304, a control circuit 306, a central processing unit (CPU) 308, a memory 310, a program code 312, and a transceiver 314. The control circuit 306 executes the program code 312 in the memory 310 through the CPU 308, thereby controlling the operation of the communication device 300. The communication device 300 can receive a signal input by a user through the input device 302 (for example, a keyboard or a keypad), and can output images and sounds through the output device 304 (for example, a monitor or a speaker). The transceiver 314 is used to receive and transmit wireless signals, pass the received signals to the control circuit 306, and wirelessly output the signals generated by the control circuit 306.

[0055] Figure 4 According to one embodiment of the present invention, Figure 3 4. In this embodiment, program code 312 includes application layer 400, layer 3 portion 402, and layer 2 portion 404, and is coupled to layer 1 portion 406. Layer 3 portion 402 typically performs radio resource control. Layer 2 portion 404 typically performs link control. Layer 1 portion 406 typically performs physical connectivity.

[0056] For LTE, LTE-A or NR systems, the layer 2 portion 404 may include a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer. The layer 3 portion 402 may include a Radio Resource Control (RRC) layer.

[0057] Any two or more of the following paragraphs, (sub)bullets, points, actions or claims described in each invention paragraph or section may be logically, reasonably and appropriately combined to form a specific method.

[0058] Any sentence, paragraph, (sub) bullet point, key point, action or claim described in each of the following invention paragraphs or sections can be implemented independently and individually to form a specific method or device. Dependencies such as "based on", "more specifically", "example" and the like in the following disclosure of the present invention are only one possible embodiment that does not limit a specific method or device.

[0059] In 3GPP TR 38.821 ([1] 3GPP TR 38.821 V16.0.0), the study of NR NTN (Non-Terrestrial Network) is introduced. NTN can be considered as a network or network segment that uses airborne or satellite-borne vehicles to carry transmission equipment relay nodes or base stations. Further descriptions are specified in [1] 3GPP TR 38.821 V16.0.0:

[0060]

[0061] 4.1 Overview of Non-terrestrial Networks

[0062] Non-terrestrial networks are networks or network segments that use RF resources on satellites (or UAS platforms).

[0063] The following depicts a typical scenario where a non-terrestrial network provides access to a user equipment:

[0064] Figure 5 It is in 3GPP TR 38.821 V16.0.0 Figure 4.1-1: Reproduction of a typical scenario for non-terrestrial networks based on transparent payload.

[0065] Figure 6 It is in 3GPP TR 38.821 V16.0.0 Figure 4 .1-2: Reproduction of a typical scenario for non-terrestrial networks based on regenerative payload.

[0066] Non-terrestrial networks typically have the following elements:

[0067] - One or more satellite gateways to connect non-terrestrial networks to the public data network

[0068] -GEO satellites are fed by one or several satellite gateways deployed across the satellite's target coverage area (e.g. regional or even continental coverage). We assume that a UE in a cell is served by only one satellite gateway

[0069] - Non-GEO satellites continuously served by one or several satellite gateways at a time. The system ensures service and feeder link continuity between continuously served satellite gateways with sufficient duration for mobility anchoring and handover

[0070] -Feeder link or radio link between satellite gateway and satellite (or UAS platform)

[0071] - The service link or radio link between the user equipment and the satellite (or UAS platform).

[0072] - Satellites (or UAS platforms) that may implement transparent or regenerative (with onboard processing) payloads. A satellite (or UAS platform) generates beams, typically several beams over a given service area bounded by its field of view. The footprint of the beam is typically elliptical in shape. The field of view of a satellite (or UAS platform) depends on the onboard antenna pattern and the minimum elevation angle.

[0073] - Transparent payload: RF filtering, frequency conversion and amplification. Therefore, the waveform signal repeated by the payload is unchanged;

[0074] - Regenerative payload: RF filtering, frequency conversion and amplification as well as demodulation / decoding, switching and / or routing, coding / modulation. This is effectively equivalent to carrying all or part of the base station functionality (e.g., gNB) onboard a satellite (or UAS platform).

[0075] -Optionally Inter-Satellite Links (ISL) in case of satellite constellations. This will require a regenerative payload onboard the satellites. ISLs can operate in RF frequencies or in the optical band.

[0076] -The user equipment is served by a satellite (or UAS platform) within the target service area.

[0077] There may be different types of satellites (or UAS platforms) listed below:

[0078]

[0079] generally

[0080] ●GEO satellites and UAS are used to provide continental, regional or local services.

[0081] Clusters of LEO and MEO satellites are used to provide services in the northern and southern hemispheres. In some cases, clusters can even provide global coverage including the polar regions. For the latter, this requires appropriate orbital inclination, adequate beamforming, and inter-satellite links.

[0082] HEO satellite systems are not considered in this paper.

[0083]

[0084] 5.2 Regenerative Satellite Based on NG-RAN Architecture

[0085] 5.2.1 Payload processed by gNB

[0086] 5.2.1.1 Overview

[0087] The NG-RAN logical architecture described in TS 38.401 is used as a baseline for the NTN scenario.

[0088] The satellite payload performs the regeneration of the signal received from the Earth.

[0089] NR-Uu radio interface over the service link between the UE and the satellite

[0090] Satellite Radio Interface (SRI) on the feeder link between the NTN gateway and the satellite.

[0091] SRI (Satellite Radio Interface) is the transmission link between NTN GW and the satellite.

[0092] Figure 7 It is in 3GPP TR 38.821 V16.0.0 Figure 5 .2.1-1: Reproduction of regenerated satellite without ISL, gNB processed payload.

[0093] Note: Satellites can enable additional traffic routing capabilities beyond the RAN range.

[0094] The satellite payload also provides inter-satellite links (ISL) between satellites.

[0095] ISL (Inter-Satellite Link) is the transmission link between satellites. ISL can be a radio interface or an optical interface, which can be 3GPP or non-3GPP defined, but this is outside the scope of the study item.

[0096] The NTN GW is a transport network layer node and supports all required transport protocols.

[0097] Figure 8 It is in 3GPP TR 38.821 V16.0.0 Figure 5 .2.1-2: Reproduction of regenerated satellite with ISL, gNB processed payload.

[0098] The figure above shows that a UE served by a gNB on a satellite can access the 5GCN via an ISL.

[0099] gNBs on different satellites can connect to the same 5GCN on the ground.

[0100] If the satellite carries more than one gNB, the same SRI will carry all corresponding NG interface instances.

[0101]

[0102] 5.2.2 Payload processed by gNB-DU

[0103] 5.2.2.1 Overview

[0104] The NG-RAN logical architecture with CU / DU split described in TS 38.401 is used as the baseline for the NTN scenario.

[0105] The satellite payload performs the regeneration of the signal received from the Earth.

[0106] ●NR-Uu radio interface over the service link between satellite and UE

[0107] ● Satellite Radio Interface (SRI) on the feeder link between the NTN gateway and the satellite. SRI transports the F1 protocol.

[0108] Satellite payloads can provide inter-satellite links between satellites.

[0109] SRI (Satellite Radio Interface) is the transport link; the logical interface F1 they transport is specified by 3GPP.

[0110] The NTN GW is a transport network layer node and supports all required transport protocols.

[0111] DUs on different satellites can connect to the same CU on the ground.

[0112] If the satellite carries more than one DU, the same SRI shall transmit all corresponding F1 interface instances.

[0113] Fig. 9 It is in 3GPP TR 38.821 V16.0.0 Figure 5 .2.2-1: Re-emergence of NG-RAN with satellite-based regeneration based on gNB-DU.

[0114]

[0115] In 3GPP TR 22.865 ([2] 3GPP TR 22.865 V2.0.0), store and forward (S&F) operation is introduced. S&F is an operation mode of a 5G system with satellite access, in which the 5G system can provide a certain level of service (in terms of store and forward data) when satellite connectivity is intermittently / temporarily unavailable, for example, providing communication services to UEs under satellite coverage without the need for a simultaneous active feeder link connection to the terrestrial segment.

[0116] [2] 3GPP TR 22.865 V2.0.0 also specifies more details, including use cases and potential requirements for S&F operations:

[0117]

[0118] Annex A (Informative):

[0119] Store and forward satellite operations

[0120] Store and forward satellite operation in 5G systems with satellite access is intended to provide a certain level of communication service to UEs under satellite coverage with intermittent / temporary satellite connectivity (e.g., when the satellite is not connected to the terrestrial network via a feeder link or via an ISL) to provide a delay tolerant communication service.

[0121] An example of “S&F Satellite Operation” is shown in Figure A-1, in contrast to what may currently be considered the “Normal / Default Satellite Operation” assumption for a 5G system with satellite access.

[0122] As shown in Figure A-1:

[0123] - In the "normal / default satellite operation" mode, the signaling and data traffic exchange between a UE with satellite access and a remote terrestrial network requires that the serving link and the feeder link are active simultaneously, so that there is a continuous end-to-end connection path between the UE, the satellite and the terrestrial network when the UE interacts with the satellite through the serving link.

[0124] - In contrast, in the "S&F Satellite Operation" mode, the end-to-end exchange of signaling / data traffic is now handled as a time Different The satellite is a combination of two steps (steps A and B in Figure A-1). In step A, signaling / data is exchanged between the UE and the satellite without the satellite being simultaneously connected to the terrestrial network (i.e., the satellite is able to operate a serving link without an active feeder link connection). In step B, a connection is established between the satellite and the terrestrial network, allowing communication between the satellite and the terrestrial network. Thus, the satellite moves from being connected to the UE in step A to being connected to the terrestrial network in step B.

[0125] Fig.10 It is a reproduction of Figure A-1 in 3GPP TR 22.865 V2.0.0: Illustration of “Normal / Default Operation” and “S&F Operation” modes in a 5G system with satellite access.

[0126] The concept of "S&F" services is widely used in the field of delay tolerant networks and outage tolerant networks. In the 3GPP context, a service that can be assimilated as an S&F service is SMS, for which there is no need to have an end-to-end connection between the endpoints (e.g. one endpoint can be a UE and the other an application server), but only between the endpoints and the SMSC acting as an intermediate node responsible for storage and dependency.

[0127] Support of S&F satellite operations is particularly applicable to NGSO satellites delivering delay tolerant / non-real-time IoT satellite services.

[0128]

[0129] 5.1 Use Case for Store and Forward - MO

[0130] 5.1.1 Description

[0131] This use case shows the implementation of S&F services between a UE with satellite access and an application server for delay tolerant / non-real-time IoT NTN services in case of mobile originated messages.

[0132] A description of the store and forward operation is provided in Appendix A.

[0133] Tracking Inc provides remote monitoring services to the field and deploys and tracks many battery powered IoT type UEs across the globe. All IoT remote monitoring UEs deployed include 5G communications with satellite access. Some UEs are deployed in remote areas where there is no mobile coverage of MNOs and only satellite is possible.

[0134] For satellite access, TrackingInc uses IoTSAT’s services for 5G IoT connectivity via satellite, and IoTSAT uses a LEO cluster that supports S&F operating modes.

[0135] All IoT remote monitoring UEs regularly send information about the area they monitor to Tracking Inc's application server and sometimes receive new parameters from the application server. In most cases, the messages exchanged are delay tolerant / non-real-time IoT.

[0136] 5.1.2 Prerequisites

[0137] In this use case, the IoT remote monitoring UE is in a remote area with no ground station available for feeder link connectivity, and the IoT remote monitoring UE is aware that the IoT SAT cluster is operating in S&F mode.

[0138] 5.1.3 Service Flow

[0139] IoT Remote Monitoring UE needs to send a message to TrackingInc application server. UE waits for satellite network coverage and sends its message when a satellite passes by.

[0140] The IoT remote monitoring UE and the satellite providing coverage interact through a service link, allowing the UE to transmit messages to the satellite, which has no connectivity to the ground segment. And therefore, the satellite must locally store the received messages.

[0141] at this time:

[0142] 1. Limitations on the size / amount of data that can be sent from a UE may be imposed.

[0143] 2. The forwarding priority of the stored data to the ground station and the data retention period of the exchanged data can be established.

[0144] 3. Acknowledgements of data received by the satellite may be issued.

[0145] At a later time, the satellite with the stored message establishes connectivity with the ground network via the feeder link and relays / forwards / downloads the message to the ground network. Once the feeder link is available, all accumulated and stored MO messages are delivered to the ground, and at the same time, all accumulated and stored related MT messages are also delivered to the satellite via the same feeder link, which will significantly affect the performance of the feeder link, 5GC and satellite. Therefore, relevant performance optimization methods will be considered.

[0146] Based on the established connectivity configuration and routing, the ground network delivers the message to the TrackingInc application server.

[0147] 5.1.4 Postconditions

[0148] Messages generated by the IoT remote monitoring UE have been successfully delivered to the Tracking Inc application server without relying on a continuous end-to-end network connectivity path therebetween, or the message has been discarded if the data retention period has exceeded.

[0149]

[0150] 5.2 Use Cases for Store and Forward - MT

[0151] 5.2.1 Description

[0152] This use case shows the implementation of S&F services between a UE with satellite access and an application server for delay tolerant / non-real-time IoT NTN services in case of mobile terminated messaging.

[0153] A description of the store and forward operation is provided in Appendix A.

[0154] Tracking Inc provides remote monitoring services to the field and deploys and tracks many battery powered IoT type UEs across the globe. All IoT remote monitoring UEs deployed include 5G communications with satellite access. Some UEs are deployed in remote areas where there is no mobile coverage of MNOs and only satellite is possible.

[0155] For satellite access, TrackingInc uses IoTSAT’s services for 5G IoT connectivity via satellite, and IoTSAT uses a LEO cluster that supports S&F operating modes.

[0156] All IoT remote monitoring UEs regularly send information about the area they monitor to Tracking Inc's application server and sometimes receive new parameters from the application server. In most cases, the messages exchanged are delay tolerant / non-real-time IoT.

[0157] 5.2.2 Prerequisites

[0158] In this use case, the IoT remote monitoring UE is in a remote area with no ground station available for feeder link connectivity, and the IoT remote monitoring UE is aware that the IoT SAT cluster is operating in S&F mode.

[0159] 5.2.3 Service Flow

[0160] The TrackingInc application server needs to send new parameters to the IoT remote monitoring UE. Based on the information provided by the network, the application server knows that the communication with the UE is in S&F mode.

[0161] The TrackingInc application server message will send the new parameters to the network entry point (e.g. SCEF, PDN-GW, SMSC) via dedicated messages via conventional means (e.g. IP routing, tunneling) and may provide additional information about delivery priority, confirmation, etc. to the network.

[0162] at this time:

[0163] 1. Limitations on the amount of data to be delivered to the IoT remote monitoring UE may be imposed.

[0164] 2. Forwarding priority to UE can be established.

[0165] 3. An acknowledgement of data received by the network may be issued to the application server, possibly with additional information regarding store and forwarding, such as an estimated time to deliver the message.

[0166] 4. End-to-end confirmation strategy can be established.

[0167] The network stores the message until it can be delivered / relayed to a satellite that is expected to fly over and provide coverage to the destination IoT remote monitoring UE.

[0168] When the satellite is connected to the ground network via a feeder link, the message is uploaded to the satellite. All accumulated and stored MT messages are uploaded to the satellite via the feeder link. At the same time, all accumulated and stored MO messages are also delivered to the 5GC via the same feeder link, which will cause performance impact on the feeder link, satellite and 5GC. Performance optimization methods are needed here. When flying over the area where the IoT remote monitoring UE is located, the satellite with stored messages triggers paging on the service link for the UE to connect to the network. (How does the satellite know where to page the UE (e.g., it must associate the stored data to the UE's location and its UE identity)? And what happens if the UE moves?)

[0169] Stored messages are delivered / downloaded from the satellite to the IoT remote monitoring UE. Acknowledgements may be requested / issued. Mechanisms to ensure the integrity of the delivered information may be in place.

[0170] 5.2.4 Postconditions

[0171] Messages generated by the TrackingInc application server have been successfully delivered to the IoT remote monitoring UE without relying on a continuous end-to-end network connectivity path therebetween.

[0172]

[0173] 5.4 Store and Forward Use Case - Data Delivery for IoT Devices in Remote Areas

[0174] 5.4.1 Description

[0175] Data transfer at remote sites is a very common requirement. Research institutions can obtain data from remote sites for scientific research, for example, animal tracking [5]. Government agencies can obtain data from remote sites, for example, via remote sensing, for disaster mitigation and avoidance [6]. Commercial companies can obtain data from remote sites for appropriate resource allocation. Data transmission at many remote sites is delay-insensitive, and satellite coverage does not always ensure that the satellite is connected to both the service link and the feeder link. In the past 30 years, many scholars have devoted themselves to studying the data transmission problem at remote sites and developed storage and forwarding mechanisms to solve the problem [7][8][9].

[0176] In remote areas, there is no terrestrial network for various reasons, for example, it is difficult to build and maintain communication towers. Therefore, this makes it challenging to collect information in these areas for environmental protection purposes. For example, sensors installed on animals need to be monitored regularly. In this scenario, the sensors installed on the animals send status information such as the movement, physiological function and surrounding environment of the animals to the satellite; and the satellite stores the received status information of the animals and forwards the information to the scientific center when the feed link becomes available.

[0177] 5.4.2 Preconditions

[0178] EA Science Center has installed sensors (IoT devices) on animals to collect information in these remote areas for environmental protection purposes. Satelles, a satellite communications operator, has launched store and forward satellite operations to support data delivery in remote areas. EA Science Center has signed a contract with Satelles to allow sensors installed on animals to send status information (e.g., animal movement, physiology, and surroundings) to the Science Center via satellite.

[0179] The satellite and IoT device are properly configured with sufficient information, such as credentials / certificates, required for the device to verify the satellite’s authenticity.

[0180] 5.4.3 Service Flow

[0181] Fig.11 It is in 3GPP TR 22.865 V2.0.0 Figure 5 .4.3-1: Re-emergence of animal tracking in remote areas.

[0182] 1. IoT devices are mounted on animals and powered, and they register in the 5G network for store-and-forward satellite operations. Satellites with store-and-forward capabilities enable IoT devices to deliver data to the network even when the feed link to the ground is unavailable. A secure connection is established between the IoT device and the satellite to protect data security and privacy.

[0183] 2. The IoT device sends sensor status information to the satellite, and the satellite stores the sensor status information received from the IoT device.

[0184] 3. When the satellite has a feeder link available for the ground segment, the satellite forwards the sensor status information and other necessary information to the ground core network. The ground core network verifies the IoT device based on the received information; if allowed, the ground core network forwards the sensor status information to its destination data network.

[0185] 4. The ground core network sends the results of the operation to the satellite (either through the same satellite or a different satellite in a remote area).

[0186] 5. When the satellite (or the next satellite) passes over a remote area, the satellite pages the UE and based on the results received from the ground core network, the satellite sends the operation results to the IoT device.

[0187] 6. If the IoT device needs to update the sensor status information, it can send it to the satellite when it is connected to the satellite. The satellite stores it and forwards the sensor status information to the ground core network when the feed link is available.

[0188] 5.4.4 Postconditions

[0189] After receiving the sensor status information at the science center, scientists can analyze the sensor status information and track the animal status.

[0190]

[0191] 5.16 Store and Forward Use Case - Emergency Reporting

[0192] 5.16.1 Description

[0193] This use case shows the implementation of S&F services between a UE with satellite access and an application server for emergency reporting service.

[0194] A description of the store and forward operation is provided in Appendix A.

[0195] Bob is sailing on an intercontinental container ship, which for some exogenous reason sinks. Bob is now stranded on a remote island, and while he is not in immediate danger, he will need to be rescued within a few days as food and water are scarce.

[0196] Several items from the container ship washed ashore with Bob, one of which was an IoT device from Tracking Inc, which had a subscription to IoTSAT for 5G IoT connectivity via satellite, and IoTSAT used a LEO cluster that supported the S&F mode of operation.

[0197] The IoT device allows Bob to send an emergency report including his location via the S&F network. The IoT device receives confirmation that the emergency report has "passed" as soon as possible. When the indicator light of the emergency button of the IoT device starts flashing green, Bob knows it is only a matter of time before Alice comes to rescue him.

[0198] 5.16.2 Prerequisites

[0199] In this use case, the emergency reporting UE is in a remote area with no ground station available for feeder link connectivity, and the emergency reporting UE is aware that the IoT SAT cluster is operating in S&F mode.

[0200] 5.16.3 Service Flow

[0201] 1. Bob is sailing on an intercontinental container ship and the ship sinks.

[0202] 2. Bob is on shore and finds TrackingInc's IoT device, which has a subscription to IoTSAT for 5G IoT connectivity via satellite.

[0203] 3. Bob uses TrackingInc’s IoT device to send an emergency report including his location via IoTSAT.

[0204] 4. Bob's emergency report is received by a flying satellite of the IoTSAT cluster and stored in the satellite awaiting delivery, since there is no feeder link available in Bob's area on shore.

[0205] 5. Satellites of the IoTSAT cluster are able to deliver the “Emergency Report” from Bob within seconds as soon as the first feeder link is available, since they identify the service as an emergency and there is no restriction to use any feeder link and ground station for such service.

[0206] 6. Notify Bob at the next flyby of a satellite from the IoTSAT cluster that the emergency report has been delivered.

[0207] 5.16.4 Postconditions

[0208] The emergency report generated by the IoT UE has been successfully delivered to the TrackingInc application server and forwarded to a service capable of processing the report, and the response has been forwarded to the IoT UE without relying on a continuous end-to-end network connectivity path therebetween.

[0209]

[0210] 6.2 Store and Forward Satellite Operation

[0211] Potential requirements for support of store and forward satellite information are listed in the following table.

[0212]

[0213]

[0214] In [4] 3GPP RWS-230178, it is specified that intermittent feeder link (FL) connectivity to ground stations may also exist over discontinuous coverage in areas where deployment of ground stations (GS) is not feasible or economical. The potential invocation flows for intermittent feeder links are specified:

[0215]

[0216] Fig.12 is a reproduction of the diagram of a possible call flow for an intermittent feeder link in 3GPP RWS-230178.

[0217]

[0218] In 3GPP TS 23.501 ([3] 3GPP TS 23.501 V18.1.0), the 5G system architecture is shown:

[0219]

[0220] 4.2.3 Non-roaming reference architecture

[0221] Figure 4 .2.3-1 describes the non-roaming reference architecture. Uses service-based interfaces within the control plane.

[0222] Fig.13 It is in 3GPP TS 23.501 V18.1.0 Figure 4 .2.3-1: Re-enactment of the non-roaming 5G system architecture.

[0223]

[0224] A non-terrestrial network (NTN) is a network that provides non-terrestrial access to a user equipment (UE), for example, by means of an NTN payload and an NTN gateway carried in the air or on a satellite NTN vehicle. The NTN may include one or more network nodes, such as a Next Generation Radio Access Network (NG-RAN) node or a Next Generation Node B / New Radio (NR) Node B (gNB). The UE may be linked to, reside on and / or connected to the NTN network for transmission and / or reception.

[0225] NTNs may include various platforms, including low earth orbit (LEO) satellites, medium earth orbit (MEO) satellites, highly elliptical orbit (HEO) satellites, geostationary orbit (GEO) satellites, geostationary synchronous orbit (GSO) satellites, non-geostationary synchronous orbit (NGSO) satellites and / or high altitude communication platforms (HAPS). LEO satellites may have geo-fixed beams (e.g., beams temporarily fixed at one location during a period of time) or geo-mobile beams (e.g., beams continuously moving together with the satellite). LEO satellites may serve / provide geo-mobile cells (e.g., having geo-fixed beams) and / or (quasi) geo-fixed cells (e.g., having geo-mobile beams).

[0226] NTN can provide large area coverage and network (NW) access in scenarios where terrestrial networks (TN) are not feasible (e.g., deserts, polar regions, and / or on airplanes). For more details on different NTN platforms, see TR 38.821 ([1] 3GPP TR 38.821 V16.0.0).

[0227] Store and forward (S&F) operation can be viewed as an operational mode of satellite access that provides a certain level of service (in terms of store and forward data) when satellite connectivity is intermittently / temporarily unavailable, e.g., providing communication services to UEs under satellite coverage without the need for an active feeder link connection to the ground segment at the same time.

[0228] A network supporting S&F operations may be based on an architecture with regenerative payload (e.g., as specified in TR 38.821 (e.g., [1] 3GPP TR 38.821 V16.0.0)). The network may include a radio access network (RAN) and / or a core network (CN). The RAN may include one or more RAN nodes. The CN may include one or more CN nodes. The RAN (or RAN node) may be (or include) an NG-RAN node, a gNB, a gNB distributed unit (DU), a gNB central unit (CU), an evolved universal terrestrial radio access network (E-UTRAN) node, an evolved Node B (eNB), and / or a base station. The CN (or CN node) may be (or include) an evolved packet core (EPC), a mobility management entity (MME), a serving gateway (S-GW), a 5G core (5GC), a user plane function (UPF), an access and mobility management function (AMF), a session management function (SMF) and / or a network node specified in TS 23.501 (e.g., [3] 3GPP TS 23.501 V18.1.0).

[0229] A network (e.g., a 5G system) can be divided into at least two parts. One part of the network, including one or more network nodes or network segments, is located on a satellite. Another part of the network, including one or more network nodes or network segments, that is not located on a satellite is located on the ground. The network node and / or network segment may be a part and / or combination of one or more network nodes (e.g., a RAN node or a CN node) and / or a network node mentioned or not mentioned above. For simplicity, a network, network node, and / or network segment located or deployed in a satellite (or, for example, a related network mentioned above) may be referred to as an NW on a satellite (or a satellite NW). A network, network node, and / or network segment located or deployed on the ground (or, for example, a related network mentioned above) may be referred to as an NW on the ground (or a ground NW).

[0230] For example, the satellite NW may be (or include) a RAN (e.g., NG-RAN, gNB, and / or eNB). The terrestrial NW may be (or include) a CN (e.g., EPC, 5GC, MME, S-GW, AMF, and / or UPF). For example, the satellite NW may be (or include) a gNB-DU. The terrestrial NW may be (or include) a gNB-CU and / or one or more CN nodes (e.g., AMF, UPF). For example, the satellite NW may be (or include) a RAN (e.g., NG-RAN, gNB, and / or eNB) and / or one or more CN nodes (or segments) (e.g., AMF, UPF, MME, S-GW). The terrestrial NW may be other one or more CN nodes (or segments) (e.g., excluding a portion of the satellite NW). For example, the satellite NW may be (or include) a first part of the MME (e.g., on a satellite). The terrestrial NW may be (or include) a second part of the MME (e.g., on the ground). The first part of the MME and the second part of the MME may be different. The first part and the second part of the MME may be mutually exclusive.

[0231] The link / connection / interface between the satellite NW and the terrestrial NW may be referred to as a feeder link. The link / connection / interface between the satellite NW and the UE may be referred to as a service link. Fig.14 An example is shown in FIG.

[0232] The UE and / or the network node (e.g., first network node, satellite NW) may be considered to be in S&F mode (or using S&F operation) if at least one or more of the following conditions are met:

[0233] - the feeder link (of the UE and / or the network node) is unavailable; and / or

[0234] - an indication that S&F Mode (and / or S&F Mode is enabled) is received (or transmitted); and / or

[0235] - received (or transmitted) a configuration related to (and / or enabled by) S&F mode; and / or

[0236] - Enabling and / or activating the S&F mode (of the UE and / or the network node).

[0237] The UE and / or the network node (e.g., first network node, satellite NW) may be considered to be in normal mode (e.g., compared to S&F mode) if at least one or more of the following conditions are met:

[0238] - a feeder link (of the UE and / or network node) is available; and / or

[0239] - no indication of S&F mode being received (or transmitted); and / or

[0240] - an indication is received (or transmitted) to deactivate (or deactivate) S&F mode; and / or

[0241] - no configuration related to (and / or enabled by) S&F mode was received (or transmitted); and / or

[0242] - received (or transmitted) a configuration to deactivate (or deactivate) S&F mode; and / or

[0243] - The S&F mode (of the UE and / or the network node) is deactivated and / or deactivated.

[0244] The UE and / or the network node may enter the S&F mode from the normal mode, and / or leave the S&F mode and enter the normal mode.

[0245] When the UE and / or the network node (eg, the first network node, the satellite NW) is in the S&F mode (or uses the S&F operation), at least one or more of the following may be performed:

[0246] - The UE may know (or be informed by the NW) that the NW is (or starts) using S&F to handle data (and / or signaling); and / or

[0247] - the UE may initiate a procedure to request (or instruct) the (satellite) NW to handle data (and / or signalling) using S&F; and / or

[0248] - the UE may perform data (and / or signalling) transfer to be handled by the S&F in the (satellite) NW; and / or

[0249] - The UE may (be ready to) perform reception of data (and / or signalling) stored in the (satellite) NW.

[0250] For user plane (UP) data, the data may be stored in the satellite NW for a period of time and then forwarded to the terrestrial NW when a feeder link between the satellite NW and the terrestrial NW is available. Fig.15 An example is shown in FIG.

[0251] For some control plane (CP) procedures (e.g., involving requests and responses) and / or UP transmissions (e.g., involving transmissions and acknowledgements, or in which a ground NW is involved), the responses (or acknowledgements) for the procedures and / or transmissions are generated by the ground NW (e.g., in normal mode, as compared to S&F mode), such as Fig.16 However, when the satellite NW is operating in S&F mode and / or the feeder link of the satellite NW is unavailable, the satellite NW is (at least temporarily) unable to communicate with the terrestrial NW. The procedure and / or transmission may thus fail, for example due to the expiration / expiration of a timer controlling the duration of the procedure and / or transmission, such as Fig.17As shown. Therefore, the procedure and / or transmission may not be performed (or completed) in a conventional manner (e.g., in normal mode). This may be due to the ground NW needing to process / handle / respond to something (e.g., response, confirmation) in the procedure and / or transmission while the ground NW is temporarily unreachable. It is not clear how to handle the procedure and / or transmission in S&F mode (or using S&F operation).

[0252] For example, the UE may initiate a registration (or attach) procedure and transmit a registration (or attach) request to the network, e.g., for initial registration (or attach), for periodic registration, and / or for mobility registration. Typically (e.g., in normal mode), a response message (e.g., registration or attach accept or reject) is generated by a CN node (e.g., MME, AMF). If the CN node is located on the ground and is not reachable when the feeder link is unavailable, it is not clear how the satellite NW handles the UE request in response to the request.

[0253] For example, the UE may initiate a service request procedure and transmit a service request to the network, e.g., for initiating a new service, for updating a service, and / or for terminating a service. Typically (e.g., in normal mode), a response message (e.g., service acceptance or rejection) is generated by a CN node (e.g., MME, AMF). If the CN node is located on the ground and is not reachable when the feeder link is unavailable, it is unclear how the satellite NW handles the UE request in response to the request.

[0254] For example, the UE may initiate a mobile originated (MO) short message service (SMS) to the NW. The UE may transmit a transfer protocol data unit (TPDU) to the NW. The UE may transmit a relay protocol-data message (RP-DATA) to the NW. The UE may start a timer (e.g., TR1*) in response to a transmission (e.g., MO SMS, TPDU, RP-DATA). The UE may expect to receive a response (e.g., confirmation, RP-Acknowledgement (ACK)) to the transmission before the expiration of the timer. After the timer expires, the UE may consider the transmission to have failed. After the timer expires, the UE may abort the transmission. When the satellite NW is in S&F mode or the feeder link of the satellite NW is unavailable, the NW may not be able to respond to the transmission in a timely manner (e.g., before the timer expires).

[0255] To solve the problem, the UE may not be allowed to initiate (or execute) a procedure and / or transmission at least in S&F mode (or using S&F operation, or when the feeder link is not available). The procedure and / or transmission may at least involve (or be related to, or be associated with) a network node (or segment) of the ground NW (for example, a response message or an acceptance message of the procedure and / or transmission is generated by the ground NW). The UE may be allowed to initiate (or execute) a procedure and / or transmission at least in normal mode (and / or not in S&F mode).

[0256] The UE may determine whether to initiate (or perform) a procedure (or transmission) based on (at least) one or more of the following conditions:

[0257] - mode of operation; and / or

[0258] - -For example, if (or when) the UE is in S&F mode (or using S&F operation).

[0259] - -For example, if (or when) the UE can only use S&F operations (e.g., for transmission).

[0260] - -For example, if (or when) the NW (eg, satellite NW, serving cell) is in S&F mode (or using S&F operation).

[0261] - Feeder link (or terrestrial NW) availability; and / or

[0262] - - For example, if (or when) a feeder link (or UE, serving cell and / or NW) is available.

[0263] - -For example, if (or when) ground NW is reachable.

[0264] - the nature of the program (or delivery); and / or

[0265] - For example, if (or when) the procedure (or transmission) is related to terrestrial NW.

[0266] - For example, if (or when) the ground NW is involved in the procedure (e.g., the response message or acceptance message is generated by the ground NW).

[0267] - services associated with the Program (or its delivery); and / or

[0268] - -For example, if (or when) a service associated with the program can be serviced (e.g., in S&F mode).

[0269] - For example, if (or when) the requirements of the service (associated with the program) can be met (e.g., in the S&F model).

[0270] - the purpose of the procedure; and / or

[0271] - For example, if (or when) the purpose is to establish (e.g., connection, registration, service).

[0272] - For example, if (or when) the purpose is to modify (e.g., connection, registration, service).

[0273] - For example, if (or when) the purpose is to release (e.g., connection, registration, service).

[0274] - For example, if (or when) the purpose is for initialization (e.g., connection, registration, service).

[0275] - For example, if (or when) the purpose is for periodic updates (e.g., connection, registration, service).

[0276] - For example, if (or when) the purpose is for mobility update (e.g., connection, registration, service).

[0277] -UE status.

[0278] - For example, if (or when) the UE is (or has been) authenticated, authorized and / or registered.

[0279] - -For example, if (or when) the UE is (or has been) connected to a network (eg, terrestrial NW).

[0280] - -For example, if (or when) the UE is (or has been) in connected state.

[0281] If / when / in response to / based on at least one or more conditions being met, the UE may not be allowed to initiate (or execute) a procedure (or transmit). If / when / in response to / based on at least one or more conditions being met, the UE may be prohibited from initiating (or executing) a procedure (or transmitting). If / when / in response to / based on at least one or more conditions being met, the UE may not initiate (or execute) a procedure (or transmit). If / when / in response to / based on at least one or more conditions not being met, the UE may be allowed to initiate (or execute) a procedure (or transmit). If / when / in response to / based on at least one or more conditions not being met, the UE may not be prohibited from initiating (or executing) a procedure (or transmitting). If / when / in response to / based on at least one or more conditions not being met, the UE may initiate (or execute) a procedure (or transmit).

[0282] If / when / in response to / based on at least one or more conditions not being satisfied, the UE may not be allowed to initiate (or execute) a procedure (or transmit). If / when / in response to / based on at least one or more conditions not being satisfied, the UE may be prohibited from initiating (or executing) a procedure (or transmitting). If / when / in response to / based on at least one or more conditions not being satisfied, the UE may not initiate (or execute) a procedure (or transmit). If / when / in response to / based on at least one or more conditions being satisfied, the UE may be allowed to initiate (or execute) a procedure (or transmit). If / when / in response to / based on at least one or more conditions being satisfied, the UE may not be prohibited from initiating (or executing) a procedure (or transmitting). If / when / in response to / based on at least one or more conditions being satisfied, the UE may initiate (or execute) a procedure (or transmit).

[0283] If the UE wishes (or needs) to initiate (or execute) a procedure (or transmission) but is prohibited (or not allowed) to do so due to at least one or more of the conditions mentioned above (e.g., satisfying the at least one or more conditions), the UE may initiate (or execute) the procedure (or transmission) when the at least one or more conditions become unsatisfied.

[0284] If the UE wishes (or needs) to initiate (or execute) a procedure (or transmission) but is prohibited (or not allowed) to do so due to at least one or more of the conditions mentioned above (for example, the at least one or more conditions are not satisfied), the UE may initiate (or execute) the procedure (or transmission) when the at least one or more conditions become satisfied.

[0285] In one or more instances, the UE may initiate the first procedure based on whether it is in the S&F mode and / or whether the feeder link is available. For example, if the UE is in the S&F mode (or the feeder link is not available), the UE is not allowed to initiate the first procedure. For example, if the UE is in the normal mode (e.g., not in the S&F mode, or the feeder link is available), the UE is allowed to initiate the first procedure. Fig.18 An example is shown in FIG.

[0286] The UE may be allowed to initiate (or execute) the second procedure when the UE is in the S&F mode (or the feeder link is unavailable).

[0287] The UE may be allowed to initiate the third procedure regardless of whether the UE is in S&F mode (or whether the feeder link is available).

[0288] The first program, the second program, and / or the third program may be different programs. The first program, the second program, and / or the third program may be the same program with different purposes (or reasons). The same program with different purposes (or reasons) may be considered as different programs here.

[0289] The treatment may be different for different programs (or transfers).

[0290] To solve the problem, if (at least) the network node is in S&F mode (or using S&F operation), the network node (e.g., satellite NW) may reject (or not accept) at least a request for a procedure (or transmission) from the UE. The procedure and / or transmission may at least involve (or be related to, or associated with) a network node (or segment) of the terrestrial NW (e.g., a response message or an acceptance message for the procedure and / or transmission is generated by the terrestrial NW).

[0291] The UE may transmit a request for at least a procedure to a network node. The network node (e.g., satellite NW) may (determine whether to) reject (or accept) the request for at least a procedure (or transmission) from the UE based on (at least) one or more of the following conditions:

[0292] - mode of operation; and / or

[0293] - -For example, if (or when) the UE is in S&F mode (or using S&F operation).

[0294] - -For example, if (or when) the UE can only use S&F operations (e.g., for transmission).

[0295] - -For example, if (or when) the NW (eg, satellite NW, serving cell) is in S&F mode (or using S&F operation).

[0296] - Feeder link or terrestrial NW availability; and / or

[0297] - - For example, if (or when) a feeder link (or UE, serving cell and / or NW) is available.

[0298] - -For example, if (or when) ground NW is reachable.

[0299] - the nature of the program (or delivery); and / or

[0300] - For example, if (or when) the procedure (or transmission) is related to terrestrial NW.

[0301] - For example, if (or when) the ground NW is involved in the procedure (e.g., the response message or acceptance message is generated by the ground NW).

[0302] - services associated with the Program (or its delivery); and / or

[0303] - -For example, if (or when) a service associated with the program can be serviced (e.g., in S&F mode).

[0304] - For example, if (or when) the requirements of the service (associated with the program) can be met (e.g., in the S&F model).

[0305] - the purpose of the procedure; and / or

[0306] - For example, if (or when) the purpose is to establish (e.g., connection, registration, service).

[0307] - For example, if (or when) the purpose is to modify (e.g., connection, registration, service).

[0308] - For example, if (or when) the purpose is to release (e.g., connection, registration, service).

[0309] - For example, if (or when) the purpose is for initialization (e.g., connection, registration, service).

[0310] - For example, if (or when) the purpose is for periodic updates (e.g., connection, registration, service).

[0311] - For example, if (or when) the purpose is for mobility update (e.g., connection, registration, service).

[0312] - The status of the UE; and / or

[0313] - For example, if (or when) the UE is (or has been) authenticated, authorized and / or registered.

[0314] - -For example, if (or when) the UE is (or has been) connected to a network (eg, terrestrial NW).

[0315] - -For example, if (or when) the UE is (or has been) in connected state.

[0316] - To configure or instruct.

[0317] - For example, if (or when) a configuration or instruction is received, for example from a ground NW.

[0318] - For example, if (or when) a network node has a (local or stored) configuration (e.g., for responding or accepting procedures).

[0319] - For example, if (or when) the network node is configured by the ground NW to, for example, handle / process / respond to a procedure.

[0320] If / when / in response to / based on satisfying at least one or more conditions, the network node (e.g., satellite NW) may reject (or not accept) the request for a procedure (or transmission) from the UE. If / when / in response to / based on not satisfying at least one or more conditions, the network node (e.g., satellite NW) may accept the request for a procedure (or transmission) from the UE.

[0321] If / when / in response to / based on at least one or more conditions not being met, the network node (e.g., satellite NW) may reject (or not accept) the request for a procedure (or transmission) from the UE. If / when / in response to / based on at least one or more conditions being met, the network node (e.g., satellite NW) may accept the request for a procedure (or transmission) from the UE.

[0322] For example, when the feeder link is available, the network node (eg, satellite NW) may receive configuration and / or indication from the ground NW. The configuration and / or indication may configure and / or indicate (whether to) reject the request for the procedure from the UE.

[0323] The network node (e.g., satellite NW) may transmit a response message to the UE, e.g., in response to a request for a procedure from the UE. The response message may be a rejection message or an acceptance message. The response message may include a cause value, e.g., a rejection cause. The cause value may be (or be related to, or associated with) S&F mode (or S&F operation), and / or feeder link unavailable.

[0324] The response message may include a timer value. The timer may be a wait timer. The value may indicate (or be used to derive) a time at which the feeder link is (expected) available (or the terrestrial NW is reachable). The UE may, for example, in response to or after receiving the response message, start a timer (e.g., a wait timer) with a value set to a value included in the response message. If / when / in response to the timer expiring, the UE may transmit (or retransmit) the request. If / when / in response to the UE detecting that the feeder link becomes available (or the terrestrial NW becomes reachable), the UE may transmit (or retransmit) the request.

[0325] In one or more instances, the network node may receive a request for a first procedure from the UE. If the network node is in S&F mode (or using S&F operation, or a feeder link of the network node is unavailable), the network node may reject the request. The network node may transmit a response message to the UE to reject the request. Fig.19 An example is shown in FIG.

[0326] The network node may not reject the request for the second procedure from the UE based on (or due to) the S&F mode (or operation) and / or the feeder link being available.

[0327] The first program and the second program may be different programs. The first program and the second program may be the same program with different purposes (or reasons). The same program with different purposes (or reasons) may be considered as different programs here.

[0328] The treatment may be different for different programs (or transfers).

[0329] To solve the problem, if (at least) the network node is in S&F mode (or uses S&F operation), the network node (e.g., satellite NW) may (temporarily) suspend at least (the request for) a procedure (or transmission) from the UE. The procedure and / or transmission may at least involve (or be related to, or be associated with) a network node (or segment) of the terrestrial NW (e.g., a response message or an acceptance message of the procedure and / or transmission is generated by the terrestrial NW). If (at least) the network node is not in S&F mode (or does not use S&F operation), for example, enters normal mode, the network node (e.g., satellite NW) may resume or continue (the request for) the procedure.

[0330] The UE may transmit a request for at least a procedure to a network node. The network node (eg, satellite NW) may (determine whether to) suspend (the request for) at least a procedure (or transmission) from the UE based on (at least) one or more of the following conditions:

[0331] - mode of operation; and / or

[0332] - -For example, if (or when) the UE is in S&F mode (or using S&F operation).

[0333] - -For example, if (or when) the UE can only use S&F operations (e.g., for transmission).

[0334] - -For example, if (or when) the NW (eg, satellite NW, serving cell) is in S&F mode (or using S&F operation).

[0335] - Feeder link or terrestrial NW availability; and / or

[0336] - - For example, if (or when) a feeder link (or UE, serving cell and / or NW) is available.

[0337] - -For example, if (or when) ground NW is reachable.

[0338] - the nature of the program (or delivery); and / or

[0339] - For example, if (or when) the procedure (or transmission) is related to terrestrial NW.

[0340] - For example, if (or when) the ground NW is involved in the procedure (e.g., the response message or acceptance message is generated by the ground NW).

[0341] - services associated with the Program (or its delivery); and / or

[0342] - -For example, if (or when) a service associated with the program can be serviced (e.g., in S&F mode).

[0343] - For example, if (or when) the requirements of the service (associated with the program) can be met (e.g., in the S&F model).

[0344] - the purpose of the procedure; and / or

[0345] - For example, if (or when) the purpose is to establish (e.g., connection, registration, service).

[0346] - For example, if (or when) the purpose is to modify (e.g., connection, registration, service).

[0347] - For example, if (or when) the purpose is to release (e.g., connection, registration, service).

[0348] - For example, if (or when) the purpose is for initialization (e.g., connection, registration, service).

[0349] - For example, if (or when) the purpose is for periodic updates (e.g., connection, registration, service).

[0350] - For example, if (or when) the purpose is for mobility update (e.g., connection, registration, service).

[0351] - The status of the UE; and / or

[0352] - For example, if (or when) the UE is (or has been) authenticated, authorized and / or registered.

[0353] - -For example, if (or when) the UE is (or has been) connected to a network (eg, terrestrial NW).

[0354] - -For example, if (or when) the UE is (or has been) in connected state.

[0355] - To configure or instruct.

[0356] - For example, if (or when) a configuration or instruction is received, for example from a ground NW.

[0357] - For example, if (or when) a network node has a (local or stored) configuration (e.g., for responding or accepting procedures).

[0358] - For example, if (or when) the network node is configured by the ground NW to, for example, handle / process / respond to a procedure.

[0359] If / when / in response to / based on at least one or more conditions being met, the network node (e.g., satellite NW) may suspend (the request of) a procedure (or transmission) from the UE. If / when / in response to / based on at least one or more conditions not being met, the network node (e.g., satellite NW) may not suspend (the request of) a procedure (or transmission) from the UE. If / when / in response to / based on at least one or more conditions not being met, the network node (e.g., satellite NW) may resume (the request of) a procedure (or transmission).

[0360] If / when / in response to / based on not satisfying at least one or more conditions, the network node (e.g., satellite NW) may suspend (the request for) a procedure (or transmission) from the UE. If at least one or more conditions are satisfied, the network node (e.g., satellite NW) may not suspend (the request for) a procedure (or transmission) from the UE. If at least one or more conditions are satisfied, the network node (e.g., satellite NW) may resume (the request for) a procedure (or transmission).

[0361] For example, when the feeder link is available, the network node (e.g., satellite NW) may receive a configuration and / or an instruction from the ground NW. The configuration and / or the instruction may configure and / or indicate (whether) to suspend (the request of) a procedure. The configuration may indicate (or be used to derive) how long the request and / or procedure is (expected to) be suspended.

[0362] The network node (e.g., satellite NW) may transmit a response message to the UE, e.g., in response to a request for a procedure from the UE. The response message may indicate that the procedure and / or request is suspended. The response message may include a cause value. The cause value may be (or related to, or associated with) S&F mode (or S&F operation), and / or the feeder link is unavailable. The UE may treat the procedure as suspended in response to (or when) receiving the response message.

[0363] The response message may include the value of the first timer. The first timer may be a waiting timer. The value may indicate (or be used to derive) the time when the feed link is (expected) available (or the ground NW is reachable). The value may be or may not be zero. The UE may, for example, start the first timer (e.g., waiting timer) with a value set to the value contained in the response message in response to (or when) receiving the response message. The UE may regard the program as suspended during / when the first timer is running. If / when / in response to receiving the response message (and / or the value of the first timer), the UE may regard the program as suspended. If the first timer expires / when the first timer expires / after the first timer expires / in response to the first timer expiring, the UE may regard the program as resumed. If the first timer expires / when the first timer expires / after the first timer expires / in response to the first timer expiring, the UE may re-initiate the program or retransmit the request.

[0364] For example, when the first timer is running, the UE may receive another message terminating (or rejecting) the procedure. The UE may terminate the procedure and / or regard the procedure as failed (or rejected) in response to receiving the message.

[0365] The response message may include a value for a second timer. The second timer may be a validity timer. The value may indicate (or be used to derive) a time for which the request and / or procedure is valid. The value may be or may not be zero. The UE may, for example, in response to or after receiving the response message, start a second timer (e.g., a validity timer) with a value set to a value included in the response message. If / when / in response to the second timer expiring, the UE may deem the procedure to have failed.

[0366] For example, if / when / in response to suspending the request and / or the procedure, the network node may start a third timer. The third timer may be a validity timer. The third timer may be set to a value configured by the ground NW. The value and / or the third timer may indicate (or be used to derive) how long the request and / or the procedure is (expected) to be suspended. If the third timer expires / when the third timer expires / after the third timer expires / in response to the third timer expiration / based on the expiration of the third timer, the network node may terminate the procedure, remove the (previously received) request, and / or not transmit (or restore, or forward, or relay) the (previously received) request to the ground NW. For example, if the third timer expires / when the third timer expires / after the third timer expires / in response to the third timer expiration / based on the expiration of the third timer, the network node may transmit a message to the UE to terminate the procedure.

[0367] The first timer, the second timer and / or the third timer may be the same. The first timer, the second timer and / or the third timer may be different.

[0368] For example, when the procedure is paused, when the first timer is running, and / or when the UE does not want to continue the procedure, the UE may transmit a message to the network node to terminate (or cancel) the procedure. In response to receiving the message, the network node may terminate (or cancel) the procedure, remove the (previously received) request, and / or not transmit (or resume, or forward, or relay) the (previously received) request to the ground NW.

[0369] For example, after the procedure is resumed, after the request message is forwarded or relayed to the ground NW, and / or in response to the request message being transmitted to the ground NW, the network node (e.g., satellite NW) may receive a response message from the ground NW. For example, in response to receiving the response message, the network node (e.g., satellite NW) may transmit / forward / relay the response message (received from the ground NW) to the UE. The response message may be an acceptance message of the procedure. In response to receiving the message, the UE may complete the procedure.

[0370] In one or more instances, the network node may receive a request for a first procedure from the UE. If the network node is in S&F mode (or using S&F operation, or a feeder link of the network node is unavailable), the network node may suspend the request. The network node may transmit a response message to the UE to suspend the request. If / when / in response to / based on the feeder link becoming available (or the terrestrial NW becoming reachable), the network node (e.g., a satellite NW) may resume the procedure. For example, if / when / in response to / based on the feeder link becoming available (or the terrestrial NW becoming reachable), the network node (e.g., a satellite NW) may transmit (or resume, or forward, or relay) the request to the terrestrial NW. Fig. 20 or Fig.21 An example is shown in FIG.

[0371] The network node may not suspend the request for the second procedure from the UE based on (or due to) the S&F mode (or operation) and / or the feeder link being available.

[0372] The first program and the second program may be different programs. The first program and the second program may be the same program with different purposes (or reasons). The same program with different purposes (or reasons) may be considered as different programs here.

[0373] The treatment may be different for different programs (or transfers).

[0374] To solve the problem, a first network node (e.g., a satellite NW) may act as a proxy for a second network node (e.g., a ground NW). If (at least) the first network node is in S&F mode (or uses S&F operation), the first network node (e.g., a satellite NW) may handle / process / respond to at least a procedure (or transmission) on behalf of the second network node (e.g., a ground NW). The procedure and / or transmission may involve (or be related to, or be associated with) at least a network node (or segment) of the ground NW (e.g., at least in normal mode, a response message or an acceptance message or confirmation of the procedure and / or transmission is generated by the ground NW). The first network node may be (or include) a satellite NW. The second network node may be (or include) a ground NW.

[0375] The UE may transmit a request for a procedure or initiate a transfer to a network (e.g., a first network node). In response to receiving the request or transfer, the first network node may respond to the UE's request or transfer (e.g., by transmitting a response or confirmation). The first network node may (determine whether to) generate and / or transmit a response message for the procedure (or transfer) to the UE based on one or more of the following conditions:

[0376] - mode of operation; and / or

[0377] - -For example, if (or when) the UE is in S&F mode (or using S&F operation).

[0378] - -For example, if (or when) the UE can only use S&F operations (e.g., for transmission).

[0379] - -For example, if (or when) the NW (eg, satellite NW, serving cell) is in S&F mode (or using S&F operation).

[0380] - -For example, the operation mode may be (or include) an S&F mode. The UE and / or the NW may be in the S&F mode.

[0381] - -For example, the operation mode may be (or include) a normal mode. The UE and / or the NW may be in the normal mode.

[0382] - Feeder link or terrestrial NW availability; and / or

[0383] - -For example, if (or when) a feeder link (of the UE, serving cell and / or NW) is available.

[0384] - -For example, if (or when) ground NW is reachable.

[0385] - -For example, a feeder link (of UE, serving cell and / or NW) may be available.

[0386] - -For example, the feeder link (of the UE, serving cell and / or NW) may not be available.

[0387] - the nature of the program (or delivery); and / or

[0388] - For example, if (or when) the procedure (or transmission) is related to a terrestrial NW.

[0389] - For example, if (or when) the ground NW is involved in the procedure (e.g., the response message or acceptance message is generated by the ground NW).

[0390] - services associated with the Program (or its delivery); and / or

[0391] - -For example, if (or when) a service associated with the program can be serviced (e.g., in S&F mode).

[0392] - For example, if (or when) the requirements of the service (associated with the program) can be met (e.g., in the S&F model).

[0393] - -For example, the service may be (or include) SMS (Short Message Service).

[0394] - -For example, the service may be (or include) an Internet of Things (IoT) service.

[0395] - -For example, the service may be (or include) a delay tolerant service.

[0396] - the purpose of the procedure; and / or

[0397] - For example, if (or when) the purpose is to establish (e.g., connection, registration, service).

[0398] - For example, if (or when) the purpose is to modify (e.g., connection, registration, service).

[0399] - For example, if (or when) the purpose is to release (e.g., connection, registration, service).

[0400] - For example, if (or when) the purpose is for initialization (e.g., connection, registration, service).

[0401] - For example, if (or when) the purpose is for periodic updates (e.g., connection, registration, service).

[0402] - For example, if (or when) the purpose is for mobility update (e.g., connection, registration, service).

[0403] - The status of the UE; and / or

[0404] - For example, if (or when) the UE is (or has been) authenticated, authorized and / or registered.

[0405] - -For example, if (or when) the UE is (or has been) connected to a network (eg, terrestrial NW).

[0406] - -For example, if (or when) the UE is (or has been) in connected state.

[0407] - To configure or instruct.

[0408] - - For example, if (or when) a configuration or indication, for example from a ground NW, is received (or available).

[0409] - For example, if (or when) a network node has a (local or stored) configuration (e.g., for responding or accepting procedures).

[0410] - For example, if (or when) the network node is configured by the ground NW to, for example, handle / process / respond to a procedure.

[0411] If / when / in response to / based on at least one or more conditions being met, the first network node may respond to the UE's request (or transmission) with a response message for the transmission or transmission procedure (e.g., accepting the request, confirming the transmission). If / when / in response to / based on at least one or more conditions not being met, the first network node may not respond to the UE's request (or transmission) with a response message for the transmission or transmission procedure (e.g., accepting the request, confirming the transmission). If / when / in response to / based on at least one or more conditions not being met, the first network node may respond to the UE's request (or transmission) with a response message for the transmission or transmission procedure (e.g., rejecting the request, suspending the request, confirming the transmission). If / when / in response to / based on at least one or more conditions not being met, the first network node may suspend the procedure in response to the UE's request.

[0412] If / when / in response to / based on not satisfying at least one or more conditions, the first network node may respond to the transmission or a response message of the transmission procedure (e.g., accepting the request, confirming the transmission) in response to the UE's request (or transmission). If / when / in response to / based on satisfying at least one or more conditions, the first network node may not respond to the transmission or a response message of the transmission procedure (e.g., accepting the request, confirming the transmission) in response to the UE's request (or transmission). If / when / in response to / based on satisfying at least one or more conditions, the first network node may respond to the transmission or a response message of the transmission procedure (e.g., rejecting the request, suspending the request, confirming the transmission) in response to the UE's request (or transmission). If / when / in response to / based on satisfying at least one or more conditions, the first network node may suspend the procedure in response to the UE's request.

[0413] The second network node may provide the first network node with instructions / information / configuration regarding the procedure (or transmission), for example, how and / or whether to handle / process / respond to the procedure (or transmission). The instructions / information / configuration may be provided in response to a request by the first network node. The instructions / information / configuration may be provided when a feeder link is available (or when the first network node is not in S&F mode).

[0414] In one or more instances, the first network node (e.g., satellite NW) may be provided with a configuration (or pre-configuration) about the first procedure, for example, by the second network node (e.g., terrestrial NW). When the first network node is in S&F mode (e.g., the feeder link is unavailable), the first network node may receive a request for the first procedure from the UE. The first network node may transmit a response message of the first procedure based on the configuration (or pre-configuration) to accept the request. Fig. 22 An example is shown in FIG.

[0415] In one or more instances, the first network node (e.g., satellite NW) may (determine) respond to a transmission from the UE (e.g., in response to receiving a transmission from the UE). The first network node may respond to the transmission by transmitting a response to the UE. The transmission may be an SMS transmission (e.g., RP-DATA). The transmission may be associated with an SMS service. The transmission may be a request. The request may be associated with a procedure. The response may be an acknowledgement (e.g., RP-ACK). The response may be a delivery report.

[0416] The first network node may (determine whether to) respond to the transmission based on (e.g., the first network node's) feeder link availability (e.g., whether the feeder link is available). For example, if (at least) the feeder link is not available, the first network node may respond to the transmission. If (at least) the feeder link is available, the first network node may not respond to the transmission. If (at least) the feeder link is available, the second network node may (be responsible for) responding to the transmission. The second network node may be a service center (SC).

[0417] The first network node may (determine whether to) respond to the transmission based on the (first network node's) operating mode (e.g., whether the first network node is in S&F mode or normal mode). If (at least) the first network node is in S&F mode, the first network node may respond to the transmission. If (at least) the first network node is in normal mode, the first network node may not respond to the transmission. If (at least) the first network node is not in S&F mode, the first network node may not respond to the transmission. If (at least) the first network node is in normal mode (or not in S&F mode), the second network node may (be responsible for) responding to the transmission.

[0418] The first network node may respond to the transmission based on a service associated with the transmission. If (at least) the service is a first service (e.g., SMS) (or a first program), the first network node may respond to the transmission. The first service may be (or include) an SMS service. If (at least) the service is a second service (or a second program), the first network node may not respond to the transmission.

[0419] Fig.23 (for S&F mode) and Fig.24 An example is shown in (for normal mode). The first network node may not accept a request for the second procedure from the UE when the first network is in S&F mode (or the feeder link is not available).

[0420] The first program and the second program may be different programs. The first program and the second program may be the same program with different purposes (or reasons). The same program with different purposes (or reasons) may be considered as different programs here.

[0421] The treatment may be different for different programs (or transfers).

[0422] The program (eg, the first program, the second program, the third program) or the transmission may be (or include) an SMS (or be associated with an SMS).

[0423] The procedures (eg, the first procedure, the second procedure, the third procedure) may be (or include) non-access stratum (NAS) procedures.

[0424] The procedure (eg, NAS procedure) may be (or include) a registration procedure. The procedure (eg, NAS procedure) may be (or include) a deregistration procedure.

[0425] The registration procedure may be used for initial registration. The UE may be in Registration Management (RM)-DETEGISTERED state.

[0426] The registration procedure can be used for mobility registration. The registration procedure can be used for periodic registration.

[0427] The registration process can be used for emergency registration. The registration process can be used for disaster roaming registration.

[0428] A procedure (eg, a NAS procedure) may be (or include) a service request procedure.

[0429] The procedure (e.g., NAS procedure) may be (or include) a (UE requested) protocol data unit (PDU) session establishment procedure. The procedure (e.g., NAS procedure) may be (or include) a (UE requested) PDU session modification procedure. The procedure (e.g., NAS procedure) may be (or include) a (UE requested) PDU session release procedure.

[0430] The program (eg, NAS program) may be (or include) a NAS transport program.

[0431] A program (eg, a NAS program) may be (or include) an attached program. A program (eg, a NAS program) may be (or include) a detached program.

[0432] The procedure (eg, NAS procedure) may be (or include) a tracking area update procedure.

[0433] The procedure (eg, NAS procedure) may be (or include) a packet data network (PDN) connectivity procedure. The procedure (eg, NAS procedure) may be (or include) a PDN disconnection procedure.

[0434] The procedure (eg, NAS procedure) may be (or include) a bearer resource allocation procedure. The procedure (eg, NAS procedure) may be (or include) a bearer resource modification procedure.

[0435] The procedure (eg, the first procedure, the second procedure, the third procedure) may be (or include) a radio resource control (RRC) procedure.

[0436] The procedure (eg, RRC procedure) may be (or include) an RRC connection establishment procedure.

[0437] The procedure (eg, RRC procedure) may be (or include) an RRC connection re-establishment procedure.

[0438] The procedure (eg, RRC procedure) may be (or include) an RRC connection recovery procedure.

[0439] The procedure (eg, RRC procedure) may be (or include) a measurement reporting procedure.

[0440] The procedure (eg, RRC procedure) may be (or include) an uplink (UL) information transfer procedure.

[0441] The procedure (eg, RRC procedure) may be (or include) a UE assistance information procedure.

[0442] The procedure (eg, RRC procedure) may be (or include) a UL message segment delivery procedure.

[0443] The procedure (eg, RRC procedure) may be (or include) a sidelink UE information procedure.

[0444] Configurations (and / or indications / parameters) related to S&F (or S&F configuration) may be associated (or specific) to an object. An object may be (or include) a UE, a cell, a connection (e.g., an RRC connection, a NAS connection), a PDU session, and / or a Quality of Service (QoS) flow. The NW may indicate (or configure) to which object the configuration (and / or indication / parameter) is associated. The NW may provide (at least) one configuration (and / or indication / parameter) to (at least) one object.

[0445] The configuration (and / or indication / parameter) related to S&F may be / include / use / indicate one or more of the following:

[0446] S&F mode indication

[0447] The indication may (at least) indicate whether S&F operation is enabled (e.g., in the cell, for the UE, to the NW). The indication may (at least) indicate whether a feeder link to the NW is available. The indication may (at least) indicate whether the UE is allowed to use S&F operation (e.g., in the cell, to the NW).

[0448] The UE may determine (whether to) use the S&F operation based on (at least) the indication. For example, if the UE receives the indication, the UE may consider the S&F operation to be enabled (and / or activated). If the UE does not receive the indication, the UE may consider the S&F operation to be not enabled (and / or activated). If the UE receives the indication, the UE may be allowed to use the S&F operation. If the UE does not receive the indication, the UE may not be allowed to use the S&F operation. The UE may have a specific UE type. The UE type is described below.

[0449] UE Type

[0450] The configuration may (at least) indicate what (types of) UEs are allowed to use S&F operation. The configuration may (at least) indicate what (types of) UEs are allowed to perform transmission and / or reception to the NW (e.g., using S&F operation). The transmission and / or reception may be (UP) data and / or (CP) signaling.

[0451] The UE type (e.g., the first type) may be based on (or identified by / represented by / specific to) UE capabilities, UE mobility, QoS characteristics of the UE, UE status. The UE type may be (or include) (at least) an enhanced machine type communication (eMTC UE), a narrowband (NB)-IoT UE, a reduced capability (RedCap) UE, a new radio (NR)-supporting UE, a 5GC-supporting UE, a NTN-supporting UE, a regenerative payload-supporting UE, a UE with a global navigation satellite system (GNSS), and / or a UE supporting S&F operations. The UE type may be (or include) (at least) a stationary UE, a low mobility UE, and / or a UE in a restricted area. The UE type may be (or include) (at least) a UE with low QoS requirements, and / or a UE without ultra-reliable low latency communication (URLLC).

[0452] The configuration may (also) be pre-configured. For example, if the UE receives an S&F mode indication, then the first type of UE is allowed to use S&F operation. For example, the first type of UE is (always) allowed to use S&F operation.

[0453] The UE may determine (whether to) use the S&F operation based on (at least) the configuration. For example, if the UE receives the configuration and / or the UE belongs to the UE type in the configuration (or pre-configuration), the UE may consider that the S&F operation is enabled (and / or activated, and / or allowed). If the UE receives the configuration and / or the UE does not belong to the UE type in the configuration (or pre-configuration), the UE may consider that the S&F operation is not enabled (and / or activated, and / or allowed). If the UE does not receive the configuration, the UE may consider that the S&F operation is not enabled (and / or activated, and / or allowed).

[0454] Business Type

[0455] The configuration may (at least) indicate what (types of) services are allowed to use S&F operation. The configuration may (at least) indicate what (types of) services are allowed to be transmitted to the NW (e.g. using S&F operation). Services may be (UP) data and / or (CP) signaling. Services may be at access stratum (AS) level and / or NAS level. The configuration may (also) be pre-configured. The configuration may be based on QoS requirements of the services (or service types).

[0456] The service (or service type) may be based on (or identified by / represented by / specific to) a QoS flow, a PDU session, a radio bearer (a signaling radio bearer (SRB) and / or a data radio bearer (DRB)), a radio link control (RLC) bearer and / or a logical channel.

[0457] Explicit configuration may be used for some services (or service types), and implicit configuration (or pre-configuration) may be used for some (other) services (or service types). For example, whether a first service (or service type) is allowed to use S&F operations may be based on configuration. Whether a second service (or service type) is allowed to use S&F operations may be based on pre-configuration (e.g., allowed, not allowed, no configuration).

[0458] The UE may determine (whether to) use the S&F operation (e.g., for a specific service or service type) based on (at least) the configuration. For example, if the UE receives the configuration and / or the service of the UE is included in the configuration (or pre-configuration), the UE may consider the S&F operation to be (or not) enabled (and / or activated, and / or allowed), for example, for the service. If the UE receives the configuration and / or the service of the UE is not included in the configuration (or pre-configuration), the UE may consider the S&F operation not to be (or is) enabled (and / or activated, and / or allowed), for example, for the service. If the UE receives the configuration and / or the service of the UE can meet the conditions / restrictions / constraints / requirements of the configuration (or pre-configuration), the UE may consider the S&F operation to be enabled (and / or activated, and / or allowed), for example, for the service. If the UE receives the configuration and / or the service of the UE cannot meet the conditions / restrictions / constraints / requirements of the configuration (or pre-configuration), the UE may consider the S&F operation not to be (or is) enabled (and / or activated, and / or allowed), for example, for the service. If the UE does not receive a configuration, the UE may consider that S&F operation is (or is not) enabled (and / or activated, and / or allowed), for example, for each (or all) services of the UE.

[0459] If the UE considers that the S&F operation is allowed / enabled / activated for the service, the UE may perform transmission (and / or reception) of the service (e.g., using the S&F operation), initiate a procedure to (or for) perform transmission (and / or reception) of the service (e.g., using the S&F operation), and / or request permission / establishment / resources for the service (e.g., using the S&F operation). The procedure may be a registration procedure (e.g., for initial and / or mobility update), a service request procedure, a PDU session establishment (or modification) procedure.

[0460] QoS parameters

[0461] The parameters may be used by the UE (e.g. based on at least the parameters) to determine (at least) whether the QoS requirements of a UE request (e.g. for a service, connection, PDU session and / or QoS flow) may be met. The parameters may be used by the UE (e.g. based on at least the parameters) to determine (at least) whether to initiate a UE request (e.g. for a service, connection, PDU session and / or QoS flow).

[0462] The parameter may be (at least) based on (or identified by / represented by / specific to) a UE, a connection, a service, a PDU session and / or a QoS flow. The configuration may (at least) indicate what type of UE, connection, service, PDU session and / or QoS flow is associated to the parameter. The parameter may be (at least) based on (or identified by / represented by / specific to) a radio bearer (SRB and / or DRB), an RLC bearer and / or a logical channel. The configuration may (at least) indicate what type of radio bearer, RLC bearer and / or logical channel is associated to the parameter.

[0463] The parameters may be (or include) (at least) a QoS flow identifier (QFI), a 5G QoS identifier (5QI), an allocation and retention priority (ARP), a resource type, a priority, a packet error rate, an averaging window, a delay budget (e.g., a packet delay budget), and / or a data volume (maximum data burst size).

[0464] The parameters may (at least) indicate the QoS (related) levels / requirements / characteristics that are allowed to use S&F operations. The parameters may (at least) indicate the maximum QoS level (e.g. latency) that the NW can satisfy. The parameters may (at least) indicate how long data (or signaling) received from the UE is expected to be stored by the NW before delivery. The parameters may (at least) indicate how long a response to a UE request is (expected) to be transmitted (or received).

[0465] The UE may determine (whether to) use the S&F operation (e.g., for a specific object, for a service, for a PDU session) based on (at least) the configuration. For example, if the UE receives the configuration and / or the UE's object (or service, or PDU session) is included in the configuration (or pre-configuration), the UE may consider the S&F operation to be (or not) enabled (and / or activated, and / or allowed), for example, for the object, for the service, and / or for the PDU session. If the UE receives the configuration and / or the UE's object (or service, or PDU session) is not included in the configuration (or pre-configuration), the UE may consider the S&F operation not to be (or is) enabled (and / or activated, and / or allowed), for example, for the object, for the service, and / or for the PDU session. If the UE receives the configuration and / or the UE's object (or service, or PDU session) can meet the conditions / restrictions / constraints / requirements of the configuration (or pre-configuration), the UE may consider the S&F operation to be enabled (and / or activated, and / or allowed), for example, for the object, for the service, and / or for the PDU session. If the UE receives a configuration and / or an object (or service, or PDU session) of the UE fails to meet the conditions / restrictions / constraints / requirements of the configuration (or pre-configuration), the UE may consider that the S&F operation is not (or is) enabled (and / or activated, and / or allowed), for example, for the object, for the service, and / or for the PDU session. If the UE does not receive a configuration, the UE may consider that the S&F operation is (or is) enabled (and / or activated, and / or allowed), for example, for each (or all) objects (or services, or PDU sessions) of the UE.

[0466] If the UE considers that the S&F operation is allowed / enabled / activated for the object (or service, or PDU session), the UE may perform transmission (and / or reception) of the object (or service, or PDU session) (e.g., using the S&F operation), initiate a procedure to (or for) perform transmission (and / or reception) of the object (or service, or PDU session) (e.g., using the S&F operation), and / or request permission / establishment / resources for the object (or service, or PDU session) (e.g., using the S&F operation). The procedure may be a registration procedure (e.g., for initial and / or mobility update), a service request procedure, a PDU session establishment (or modification) procedure.

[0467] In order to determine whether a service (or PDU session, or UE) is allowed to use S&F operations, at least the objects of the service (or PDU session, or UE) need to meet the configured QoS. For example, if no object of the service (or PDU session, or UE) meets the configured QoS, the UE may not be allowed to use S&F operations for the service (or PDU session, or UE). If each object of the service (or PDU session, or UE) meets the configured QoS, the UE may be allowed to use S&F operations for the service (or PDU session, or UE). If some (certain) object (e.g., a first object) of the service (or PDU session, or UE) meets the configured QoS and some (certain) other object (e.g., a second object) of the service (or PDU session, or UE) does not meet the configured QoS, the UE may be allowed to use S&F operations for the first object and may not be allowed to use S&F operations for the second object. If some(certain) object(s) of a service (or PDU session, or UE) (e.g., the first object) satisfies the configured QoS and some(certain) other object(s) of the service (or PDU session, or UE) (e.g., the second object) does not satisfy the configured QoS, the UE may not be allowed to use S&F operations for the service (or PDU session, or UE) (e.g., including the first object and the second object). If some(certain) object(s) of a service (or PDU session, or UE) (e.g., the first object) satisfies the configured QoS and some(certain) other object(s) of the service (or PDU session, or UE) (e.g., the second object) does not satisfy the configured QoS, the UE may be allowed to use S&F operations for the service (or PDU session, or UE) (e.g., including the first object and the second object).

[0468] An object may be (or include) (at least) a connection, a service, a PDU session and / or a QoS flow. An object may be (or include) (at least) a radio bearer, an RLC bearer and / or a logical channel.

[0469] Data volume

[0470] The configuration may (at least) indicate a limit on the amount of data allowed using S&F operation. The configuration may (at least) indicate how much data may be transferred to the NW (e.g. using S&F operation). The data may be (or include) UP data and / or CP signaling. The data may be AS level and / or NAS level.

[0471] The configuration may be (at least) based on (or identified by / represented by / specific to) a UE, a connection, a service, a PDU session and / or a QoS flow. The configuration may (at least) indicate what (or which) UE, connection, service, PDU session and / or QoS flow is associated to the configuration. The configuration may be (at least) based on (or identified by / represented by / specific to) a radio bearer (SRB and / or DRB), an RLC bearer and / or a logical channel. The configuration may (at least) indicate what (or which) radio bearer, RLC bearer and / or logical channel is associated to the parameter.

[0472] The UE may determine (whether) to use the S&F operation (e.g., for a specific object) based on (at least) the configuration. The UE may determine (whether) to stop the S&F operation (e.g., for a specific object) based on (at least) the configuration. The UE may determine (whether) the S&F operation (e.g., for a specific object) may continue based on (at least) the configuration.

[0473] An object may be (or include) (at least) a UE, a connection, a service, a PDU session and / or a QoS flow. An object may be (or include) (at least) a radio bearer, an RLC bearer and / or a logical channel.

[0474] For example, if the UE receives a configuration and / or the UE's service (e.g., for an object) has not exceeded the data amount, the UE may (be allowed to) use the S&F operation, e.g., for the service. If the UE receives a configuration and / or the UE's service (e.g., for an object) has exceeded the data amount, the UE may not (be allowed to) use the S&F operation, e.g., for the service. If the UE does not receive a configuration, the UE may assume that there is no data amount limitation for using the S&F operation, e.g., for the UE, for the object.

[0475] If the UE considers that the S&F operation is allowed (e.g., for the service), the UE may perform (or continue) transmission (and / or reception) of the service (e.g., using the S&F operation), initiate a procedure to (or for) perform transmission (and / or reception) of the service (e.g., using the S&F operation), and / or request permission / establishment / resources for the service (e.g., using the S&F operation). The procedure may be a registration procedure (e.g., for initial and / or mobility update), a service request procedure, a PDU session establishment (or modification) procedure.

[0476] If the UE has transmitted data exceeding the data volume, the UE may stop S&F operation, stop transmitting data, stop the (ongoing) procedure. If the UE has transmitted data exceeding the data volume, the UE may transmit an indication to the NW (e.g., indicating that the data volume limit has been reached), initiate a (RRC and / or NAS) connection release (request) procedure, initiate a deregistration procedure, and / or initiate a PDU session release (or modification) procedure (e.g., release a PDU session). If the UE has transmitted data exceeding the data volume, the UE may release the (RRC and / or NAS) connection, and / or enter an (RRC and / or NAS) idle mode (e.g., RRC_IDLE, Connection Management (CM)_IDLE).

[0477] The NW may be (or include) a satellite NW. The satellite NW may be (or include) a network node, a CN node, a RAN node, an AMF, an SMF, an MME, a RAN, a NG-RAN, an eNB, a gNB, a part of the above (e.g., a satellite part of the above), and / or a combination of the above.

[0478] The NW may be (or include) a terrestrial NW. The terrestrial NW may be (or include) a network node, a CN node, a RAN node, an AMF, an SMF, an MME, a RAN, an NG-RAN, an eNB, a gNB, a part of the above items (e.g., the terrestrial part of the above items), and / or a combination of the above items.

[0479] Satellite NW and terrestrial NW may be mutually exclusive.

[0480] NW may be (or include) a cell. NW may be (or include) a serving cell. NW may be (or include) a neighboring cell. NW may be (or include) a source cell. NW may (or include) a target cell.

[0481] The UE may be in RRC connected mode. The UE may be in RRC idle mode. The UE may be in RRC inactive mode.

[0482] The UE may be in CM Idle state. The UE may be in CM Connected state.

[0483] The UE may be in RM deregistered state. The UE may be in RM registered state.

[0484] The UE may be in a cell of the NTN. The UE may be connected to a cell of the NTN. The UE may be connected to LEO, GEO, MEO, HEO and / or HAPS.

[0485] UE may be referred to as UE, an RRC entity of UE, or a MAC entity of UE.

[0486] The UE may be a NR device. The UE may be a NR light device. The UE may be a device with insufficient capabilities. The UE may be a mobile phone. The UE may be a wearable device. The UE may be a sensor. The UE may be a fixed device.

[0487] NW may be a network node. NW may be a base station. NW may be an access point. NW may be an eNB. NW may be a gNB. NW may be a gateway.

[0488] Exemplary embodiments of the present invention are described below.

[0489] See also Fig.25 , with respect to such and other concepts, systems and methods of the present invention, a method 1000 for a UE in a wireless communication system includes receiving an indication of operating in an S&F mode (step 1002), and determining whether to initiate a procedure based on whether the UE is operating in the S&F mode (step 1004).

[0490] In various embodiments, the UE is not allowed to initiate the procedure if (at least) the UE is operating in S&F mode.

[0491] Reference now Figure 3 and 4 In one or more embodiments from the perspective of a UE in a wireless communication system, the apparatus 300 includes program code 312 stored in a memory 310 of a transmitter. The CPU 308 may execute the program code 312 to: (i) receive an indication of operating in an S&F mode; and (ii) determine whether to initiate a procedure based on whether the UE is operating in an S&F mode. In addition, the CPU 308 may execute the program code 312 to perform all described actions, steps, and methods described above, below, or otherwise herein.

[0492] See also Fig.26 , with respect to such and other concepts, systems and methods of the present invention, a method 1010 for a first network node in a wireless communication system includes transmitting an indication to operate in an S&F mode (step 1012), receiving a request for a procedure from a UE (step 1014), and determining whether to deny the request based on whether the first network node is operating in the S&F mode (step 1016).

[0493] In various embodiments, if (at least) the first network node is operating in the S&F mode, the first network node transmits a rejection message in response to the request.

[0494] Reference now Figure 3 and 4, in one or more embodiments from the perspective of a first network node in a wireless communication system, the apparatus 300 includes program code 312 stored in a memory 310 of a transmitter. The CPU 308 may execute the program code 312 to: (i) transmit an indication of operating in S&F mode; (ii) receive a request for a procedure from a UE; and (iii) determine whether to deny the request based on whether the first network node is operating in S&F mode. In addition, the CPU 308 may execute the program code 312 to perform all described actions, steps, and methods described above, below, or otherwise herein.

[0495] See also Fig. 27 , with respect to such and other concepts, systems and methods of the present invention, a method 1020 for a first network node in a wireless communication system includes transmitting an indication of operating in an S&F mode (step 1022), receiving a request for a procedure from a UE (step 1024), and determining whether to store the request based on whether the first network node is operating in the S&F mode (step 1026).

[0496] In various embodiments, if (at least) the first network node is operating in S&F mode, the first network node stores the request.

[0497] In various embodiments, the first network node transmits the request to the second network node when (at least) the first network node leaves the S&F mode.

[0498] Reference now Figure 3 and 4 , in one or more embodiments from the perspective of a first network node in a wireless communication system, the apparatus 300 includes program code 312 stored in a memory 310 of a transmitter. The CPU 308 may execute the program code 312 to: (i) transmit an indication of operating in S&F mode; (ii) receive a request for a procedure from a UE; and (iii) determine whether to store the request based on whether the first network node is operating in S&F mode. In addition, the CPU 308 may execute the program code 312 to perform all described actions, steps, and methods described above, below, or otherwise herein.

[0499] See also Fig.28 , with respect to such and other concepts, systems and methods of the present invention, a method 1030 for a first network node in a wireless communication system includes transmitting an indication of operating in an S&F mode (step 1032), receiving a request for a procedure from a UE (step 1034), and determining whether to respond to the request based on whether the first network node is operating in the S&F mode (step 1036).

[0500] In various embodiments, the method further includes the first network node determining whether to respond to the request based on whether the first network node receives a configuration regarding the procedure from the ground NW.

[0501] In various embodiments, the first network node is located or deployed in a satellite.

[0502] Reference now Figure 3 and 4 , in one or more embodiments from the perspective of a first network node in a wireless communication system, the apparatus 300 includes program code 312 stored in a memory 310 of a transmitter. The CPU 308 may execute the program code 312 to: (i) transmit an indication of operating in S&F mode; (ii) receive a request for a procedure from a UE; and (iii) determine whether to respond to the request based on whether the first network node is operating in S&F mode. In addition, the CPU 308 may execute the program code 312 to perform all described actions, steps, and methods described above, below, or otherwise herein.

[0503] See also Fig.29 , with respect to such and other concepts, systems and methods of the present invention, a method 1040 for a first network node in a wireless communication system includes receiving a transmission from a UE (step 1042), and determining a transmission to the UE in response based on that a feeder link of the first network node is unavailable and a service associated with the transmission is SMS (step 1044).

[0504] In various embodiments, the first network node is in S&F mode or transmits an S&F mode indication to the UE.

[0505] In various embodiments, the first network node determines to respond to the transmission to the UE based on feeder link availability of the first network node, a service associated with the transmission and / or whether the first network node is in S&F mode.

[0506] In various embodiments, the transmitted response is generated by the second network node when a feeder link of the first network node is available and / or the first network node is in normal mode.

[0507] In various embodiments, the second network node is on the ground, belongs to a ground network, and / or comprises another part of the MME.

[0508] In various embodiments, the first network node responds to the transmission to the UE on behalf of the second network node.

[0509] In various embodiments, the first network node is on a satellite, belongs to a satellite network, and / or comprises a part of an MME.

[0510] In various embodiments, the feeder link is between the first network node and the second network node.

[0511] In various embodiments, the first network node stores the transmission when a feeder link of the first network node is unavailable and / or the first network node is in S&F mode.

[0512] In various embodiments, S&F mode allows satellite access to provide a certain level of service when satellite connectivity is temporarily unavailable.

[0513] Reference now Figure 3 and 4 , in one or more embodiments from the perspective of a first network node in a wireless communication system, the apparatus 300 includes program code 312 stored in a memory 310 of a transmitter. The CPU 308 may execute the program code 312 to: (i) receive a transmission from a UE; and (ii) determine a response to the transmission to the UE based on that a feeder link of the first network node is unavailable and that a service associated with the transmission is SMS. In addition, the CPU 308 may execute the program code 312 to perform all described actions, steps, and methods described above, below, or otherwise herein.

[0514] Any combination of the concepts or teachings above or herein may be fully or partially combined or formed into new embodiments. The disclosed details and embodiments may be used to at least (but not limited to) solve the problems mentioned above and herein.

[0515] It should be noted that any of the methods, alternatives, steps, examples and embodiments presented herein may be applied independently, individually and / or in combination with multiple methods, alternatives, steps, examples and embodiments.

[0516] Various aspects of the present disclosure have been described above. It should be clear that the teachings herein can be implemented in a wide variety of forms, and any specific structure, function, or both disclosed herein are only representative. Based on the teachings herein, it should be understood by those skilled in the art that the aspects disclosed herein can be implemented independently of any other aspects, and two or more of these aspects can be combined in different ways. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, by using other structures, functionality, or structures and functionality other than one or more aspects of the aspects set forth herein or different from one or more aspects of the aspects set forth herein, this device can be implemented or this method can be practiced. As an example of some of the above concepts, in some aspects, parallel channels can be established based on pulse repetition frequencies. In some aspects, parallel channels can be established based on pulse positions or offsets. In some aspects, parallel channels can be established based on time hopping sequences. In some aspects, parallel channels can be established based on pulse repetition frequencies, pulse positions or offsets, and time hopping sequences.

[0517] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0518] Those of ordinary skill in the art will further appreciate that the various illustrative logical blocks, modules, processors, components, circuits, and algorithm steps described in conjunction with the various aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which may be designed using source decoding or some other technique), and various forms of programs or design codes with instructions (which may be referred to herein as "software" or "software modules" for convenience), or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing a deviation from the scope of the present disclosure.

[0519] In addition, the various illustrative logical blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented within or performed by an integrated circuit ("IC"), an access terminal, or an access point. The IC may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute code or instructions residing within the IC, outside the IC, or both. A general-purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0520] It should be understood that any specific order or hierarchy of steps in any disclosed process is an example of an exemplary method. It should be understood that based on design preferences, the specific order or hierarchy of steps in a process can be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order and are not intended to be limited to the specific order or hierarchy presented.

[0521] The steps of the method or algorithm described in conjunction with the various aspects disclosed herein may be implemented directly in hardware, in software modules executed by a processor, or in a combination of the two. Software modules (e.g., containing executable instructions and associated data) and other data may reside in a data memory, such as a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of a computer-readable storage medium known in the art. A sample storage medium may be coupled to a machine such as a computer / processor (for convenience, the machine may be referred to herein as a "processor") so that the processor may read information (e.g., code) from the storage medium and write information to the storage medium. A sample storage medium may be integrated with a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user device. In an alternative, the processor and the storage medium may reside in a user device as discrete components. In addition, in some aspects, any suitable computer program product may include a computer-readable medium, the computer-readable medium including code related to one or more of the various aspects of the present disclosure. In some aspects, a computer program product may include packaging materials.

[0522] Although the present invention has been described in conjunction with various aspects and examples, it will be appreciated that the present invention is capable of further modifications. This application is intended to cover any changes, uses or adaptations of the present invention, which generally follow the principles of the present invention and include such deviations from the present disclosure, which are within the scope of known and customary practice in the technical field to which the present invention belongs.

Claims

1. A method for a first network node, characterized in that include: receiving a transmission from a user device; as well as Responding to the transmission to the user equipment is determined based on a feeder link of the first network node being unavailable and a service associated with the transmission being a short message service.

2. The method according to claim 1, characterized in that The first network node is in a store and forward mode or transmits a store and forward mode indication to the user equipment.

3. The method according to claim 1, characterized in that The first network node determines to respond to the transmission to the user equipment based on feeder link availability of the first network node, the service associated with the transmission and / or whether the first network node is in store and forward mode.

4. The method according to claim 1, characterized in that: The transmitted response is generated by the second network node when the feeder link of the first network node is available and / or the first network node is in normal mode.

5. The method according to claim 1, characterized in that The first network node responds to the transmission to the user equipment on behalf of a second network node.

6. The method according to claim 1, characterized in that The first network node is on a satellite, belongs to a satellite network, and / or comprises a part of a mobility management entity.

7. The method according to claim 4, characterized in that The second network node is on the ground, belongs to a ground network, and / or comprises another part of a mobility management entity.

8. The method according to claim 1, characterized in that The feeder link is between the first network node and a second network node.

9. The method according to claim 1, characterized in that: The first network node stores the transmission when the feeder link of the first network node is unavailable and / or the first network node is in store and forward mode.

10. The method according to claim 1, characterized in that The store and forward mode allows satellite access to provide a certain level of service when satellite connectivity is temporarily unavailable.

11. A first network node, characterized in that: include: Memory; as well as a processor operatively coupled to the memory, wherein the processor is configured to execute program code to: receiving a transmission from a user device; as well as Responding to the transmission to the user equipment is determined based on a feeder link of the first network node being unavailable and a service associated with the transmission being a short message service.

12. The first network node according to claim 11, characterized in that: The first network node is in a store and forward mode or transmits a store and forward mode indication to the user equipment.

13. The first network node according to claim 11, characterized in that: The first network node determines to respond to the transmission to the user equipment based on feeder link availability of the first network node, the service associated with the transmission and / or whether the first network node is in store and forward mode.

14. The first network node according to claim 11, characterized in that: The transmitted response is generated by the second network node when the feeder link of the first network node is available and / or the first network node is in normal mode.

15. The first network node according to claim 11, characterized in that: The first network node responds to the transmission to the user equipment on behalf of a second network node.

16. The first network node according to claim 11, characterized in that: The first network node is on a satellite, belongs to a satellite network, and / or comprises a part of a mobility management entity.

17. The first network node according to claim 14, characterized in that: The second network node is on the ground, belongs to a ground network, and / or comprises another part of a mobility management entity.

18. The first network node according to claim 11, characterized in that: The feeder link is between the first network node and a second network node.

19. The first network node according to claim 11, characterized in that: The first network node stores the transmission when the feeder link of the first network node is unavailable and / or the first network node is in store and forward mode.

20. The first network node according to claim 11, characterized in that: The store and forward mode allows satellite access to provide a certain level of service when satellite connectivity is temporarily unavailable.

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