US-12627494-B2 - Communications system with low-bandwidth messaging

Abstract

A communications system may include a satellite constellation and a terrestrial network that convey text messages between first and second user equipment (UE) devices. The terrestrial network may include a core network, an inter-working function (IWF) server, and carrier networks. The IWF server may distribute keys and the first UE device may transmit provisioning data to the core network while the first UE device is on-grid. When the first UE device goes off-grid, the first UE device may transmit an escrow key to the core network for use in decrypting a device public key from the provisioning data. The core network may transmit the device public key and other information to the IWF for use in routing messages via the NTN. The core network may use the handles to enforce an allow list that filters traffic to the first UE device over the NTN.

Inventors

• Abhishek WALIA
• Gregory R Nelson
• Samy Touati
• Nelson M LeDuc

Assignees

• APPLE INC.

Dates

Publication Date

20260512

Application Date

20240926

Claims (20)

1. 1 . A method of operating a user equipment (UE) device, comprising: receiving, using one or more antennas, a first cryptographic key from a core network via terrestrial-based wireless equipment; encrypting, using one or more processors, a second cryptographic key using a third cryptographic key; transmitting, using the one or more antennas, provisioning data to the core network via the terrestrial-based wireless equipment for use after the UE device has gone off grid, wherein the provisioning data includes the encrypted second cryptographic key; and transmitting, using the one or more antennas while the UE device is off grid, the third cryptographic key to the core network via a satellite constellation for use by the core network in decrypting the encrypted second cryptographic key in the provisioning data.
2. 2 . The method of claim 1 , further comprising: transmitting, using the one or more antennas, a mobile originated (MO) message to the core network via the satellite constellation after transmission of the third cryptographic key to the core network.
3. 3 . The method of claim 2 , wherein transmitting the third cryptographic key comprises transmitting the third cryptographic key in a service request message transmitted to the core network via the satellite constellation.
4. 4 . The method of claim 2 , wherein the first cryptographic key is associated with a cellular telephone network of the UE device.
5. 5 . The method of claim 4 , wherein the provisioning data includes: a key identifier associated with the first cryptographic key; and a subscriber identity module (SIM) credential associated with the UE device and the cellular telephone network.
6. 6 . The method of claim 4 , wherein the terrestrial-based wireless equipment comprises a base station of the cellular telephone network or an access point of a wireless local area network.
7. 7 . The method of claim 4 , wherein the MO message is end-to-end encrypted between the UE device and an inter-working function (IWF) server that is separate from the core network and the cellular telephone network.
8. 8 . The method of claim 7 , wherein transmitting the MO message comprises encrypting the MO message based at least on the first cryptographic key.
9. 9 . The method of claim 1 , further comprising: receiving, using the one or more antennas, a mobile terminated (MT) message from the core network via the satellite constellation after transmission of the third cryptographic key to the core network.
10. 10 . The method of claim 9 , wherein the MT message is end-to-end encrypted between the UE device and an inter-working function (IWF) server, the IWF server is separate from the core network and a cellular telephone network associated with the terrestrial-based wireless equipment, the second cryptographic key belongs to a public-private key pair that includes a fourth cryptographic key, and receiving the MT message comprises decrypting the MT message based at least on the fourth cryptographic key.
11. 11 . The method of claim 9 , further comprising: receiving, using the one or more antennas, status information from the core network via the satellite constellation, wherein the status information identifies a status of a message queue maintained at the core network for the UE device; and displaying, using a display, the MT message and the status information.
12. 12 . The method of claim 1 , further comprising: generating, using the one or more processors, a list of handles associated with contacts on a contact list maintained at the UE device, wherein the provisioning data includes the list of handles, the contacts are associated with respective UE identifiers, the handles are generated using a cryptographic function based at least on the respective UE identifiers, the handles are smaller than the UE identifiers, and the cryptographic function is periodically updated after a predetermined time period.
13. 13 . The method of claim 12 , wherein the respective UE identifiers comprise Mobile Station International Subscriber Directory Numbers associated with the contacts on the contact list.
14. 14 . The method of claim 1 , further comprising: transmitting, using the one or more antennas, a mobile originated (MO) message to a recipient UE device via the satellite constellation, the core network, and an inter-working function (IWF) server, wherein the MO message includes a data payload that is end-to-end encrypted between the UE device and the IWF server, the recipient UE device has a corresponding UE identifier, and the MO message includes a handle associated with the UE identifier of the recipient UE device.
15. 15 . The method of claim 14 , further comprising: generating, using the one or more processors, the handle based at least on the UE identifier of the recipient device, a cryptographic function, and the first cryptographic key.
16. 16 . An electronic device comprising: a receiver configured to receive a first cryptographic key from a core network via terrestrial-based wireless equipment; one or more processors configured to generate an encrypted key by encrypting a second cryptographic key using a third cryptographic key; and a transmitter configured to transmit: provisioning data to the core network via the terrestrial-based wireless equipment, wherein the provisioning data includes the encrypted key, and the third cryptographic key to the core network via a satellite constellation.
17. 17 . The electronic device of claim 16 , further comprising: a display, wherein the receiver is configured to receive a mobile terminated (MT) text message from the core network via the satellite constellation after transmission of the third cryptographic key to the core network, and the display is configured to display the MT text message.
18. 18 . The electronic device of claim 17 , wherein the receiver is configured to receive status information from the core network via the satellite constellation, the status information identifies a status of a message queue maintained at the core network for the electronic device, and the display is configured to display a graphical user interface (GUI) that includes the MT text message and the status information.
19. 19 . A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device, the one or more programs comprising instructions for: receiving, while the electronic device is on-grid with a terrestrial-based wireless network, a first cryptographic key from a core network; generating an encrypted key by encrypting a second cryptographic key using a third cryptographic key; transmitting, while the electronic device is on-grid with the terrestrial-based wireless network, the encrypted key to the core network; and transmitting, while the electronic device is off-grid with the terrestrial-based wireless network, the third cryptographic key to the core network via a satellite constellation.
20. 20 . The non-transitory computer readable storage medium of claim 19 , the one or more programs further comprising instructions for: transmitting, while the electronic device is on-grid with the terrestrial-based wireless network, a key identifier associated with the first cryptographic key and a subscriber identity module (SIM) credential of the electronic device; and transmitting, while the electronic device is off-grid with the terrestrial-based wireless network, a mobile originated (MO) text message to the core network via the satellite constellation after transmission of the third cryptographic key to the network, wherein the MO message is end-to-end encrypted between the electronic device and an inter-working function (IWF) server based at least on the first cryptographic key; and displaying, on a display, the MO text message.

Description

This application claims the benefit of U.S. Provisional Patent Application No. 63/657,574 filed Jun. 7, 2024, which is hereby incorporated by reference herein in its entirety. FIELD This relates generally to wireless communications, including wireless communications between user equipment devices. BACKGROUND Communications systems are used to convey data between terminals such as user equipment (UE) devices. A communications system can include a wireless network that wirelessly conveys data between UE devices. In practice, some wireless networks can exhibit limited speed and/or bandwidth in conveying data between UE devices. Care should be taken to ensure that a UE device does not need to wait an excessive amount of time to successfully transmit or receive data and to ensure that the wireless network conveys the data while maintaining sufficient levels of security and user privacy. SUMMARY A communications system may include a non-terrestrial network (NTN) and a terrestrial network that convey wireless data such as text messages between at least first and second user equipment (UE) devices. The terrestrial network may include a core network, an inter-working function (IWF) server, and a set of carrier networks. The NTN may include a constellation of communications satellites. The first UE device may move between being on-grid and connected to the terrestrial network and being off-grid and disconnected from the terrestrial network. The IWF server may distribute IWF keys for each carrier network to the core network. The core network may distribute a public key from the IWF keys to the first UE device while the first UE device is on-grid. The first UE device may transmit provisioning data to the core network while the first UE device is on-grid. The provisioning data may include an allow list of UE handles, a subscriber identity module (SIM) credential of the first UE device, a key identifier associated with the public key distributed to the first UE device, and an encrypted device public key generated by the first UE device using an escrow key. When the first UE device goes off grid, the first UE device may transmit the escrow key to the core network. The core network may decrypt the encrypted device public key from the provisioning data using the escrow key. The core network may transmit the SIM credential, the key identifier, and the decrypted device public key to the IWF. The IWF may use this information to route messages between the first UE device and the second UE device via the core network, the NTN, and the carrier network. The core network may use the handles to enforce an allow list policy to filter traffic to the first UE device over the NTN while hiding the identity of the second UE device from the core network. The IWF may allow the first UE device to appear to the carrier network and the second UE device as if the UE device is on-grid and connected to the terrestrial network. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of an illustrative communications system including user equipment devices that communicate via a terrestrial network and a non-terrestrial network in accordance with some embodiments. FIG. 2 is a schematic diagram of an illustrative user equipment device in accordance with some embodiments. FIG. 3 is a schematic diagram of an illustrative communications satellite in accordance with some embodiments. FIG. 4 is a flow chart of illustrative operations involved in conveying data between first and second user equipment devices using a communications system that includes a terrestrial network and a non-terrestrial network in accordance with some embodiments. FIG. 5 is an illustrative diagram showing how cryptographic keys and provisioning data may be distributed between an inter-working function (IWF) server, a core network, and a user equipment device while the user equipment device is on-grid in accordance with some embodiments. FIG. 6 is a diagram showing how an illustrative user equipment device may store cryptographic keys and generate user equipment handles in accordance with some embodiments. FIG. 7 is a diagram showing how an illustrative user equipment device may generate provisioning data that is distributed to a core network while the user equipment device is on-grid in accordance with some embodiments. FIG. 8 is an illustrative diagram showing how an escrow key and provisioning data may be distributed between a user equipment device, a core network, and an IWF server while the user equipment device is off-grid in accordance with some embodiments. FIG. 9 is a flow chart of illustrative operations involved in provisioning cryptographic keys and user equipment handles while a user equipment device is on-grid in accordance with some embodiments. FIG. 10 is a flow chart of illustrative operations involved in conveying wireless data between a first user equipment device and a second user equipment device using an IWF server and a core network while the first user equipme