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US-20260129417-A1 - HANDLING OF RAT UTILIZATION UNDER DISASTER CONDITIONS

US20260129417A1US 20260129417 A1US20260129417 A1US 20260129417A1US-20260129417-A1

Abstract

Systems, methods, and devices for handling of RAT utilization under disaster conditions. The WTRU registers with a first public land mobile network (PLMN) on a first radio access technology (RAT). The WTRU receives, from the first PLMN, information indicating that a restriction on a second RAT is applicable for the first PLMN. The WTRU receives information indicating that the first PLMN is under a disaster condition. The WTRU transmits a registration request to a second PLMN. The WTRU receives a registration rejection message from the second PLMN. The WTRU receives, from the second PLMN, information indicating that the restriction on the second RAT is not applicable for the first PLMN. The WTRU registers with the first PLMN on the second RAT.

Inventors

  • Anuj SETHI
  • Michael Starsinic
  • Samir Ferdi
  • Taimoor ABBAS
  • Saad Ahmad

Assignees

  • INTERDIGITAL PATENT HOLDINGS, INC.

Dates

Publication Date
20260507
Application Date
20241107

Claims (20)

  1. 1 . A method for use in a wireless transmit/receive unit (WTRU), the method comprising: registering with a first public land mobile network (PLMN) on a first radio access technology (RAT); receiving, from the first PLMN, information indicating that a restriction on a second RAT is applicable for the first PLMN; receiving information indicating that the first PLMN is under a disaster condition; transmitting a registration request to a second PLMN; receiving a registration rejection message from the second PLMN; receiving, from the second PLMN, information indicating that the restriction on the second RAT is not applicable for the first PLMN; and registering with the first PLMN on the second RAT.
  2. 2 . The method of claim 1 , wherein the information indicating that the first PLMN is under the disaster condition is received in a broadcast from the second PLMN.
  3. 3 . The method of claim 2 , wherein the broadcast comprises a system information block (SIB).
  4. 4 . The method of claim 3 , further comprising requesting an additional SIB that includes information indicating that the restriction on the second RAT is not applicable for the first PLMN, and location information, responsive to the broadcast SIB.
  5. 5 . The method of claim 1 , wherein the registration request to the second PLMN indicates a request for disaster roaming service.
  6. 6 . The method of claim 1 , wherein the registration request to the second PLMN indicates a request for normal service.
  7. 7 . The method of claim 1 , wherein the registration rejection message from the second PLMN includes information indicating that the restriction on the second RAT is not applicable to the WTRU for the first PLMN.
  8. 8 . The method of claim 7 , wherein the information indicating that the first PLMN is under the disaster condition includes location information, wherein the information indicating that the restriction on the second RAT is not applicable to the WTRU for the first PLMN is applicable within a geographic area that is based on the location information.
  9. 9 . The method of claim 1 , wherein the first RAT comprises a 5G RAT.
  10. 10 . The method of claim 1 , wherein the second RAT comprises a 4G RAT.
  11. 11 . A wireless transmit/receive unit (WTRU) comprising: circuitry configured to register with a first public land mobile network (PLMN) on a first radio access technology (RAT); circuitry configured to receive, from the first PLMN, information indicating that a restriction on a second RAT is applicable for the first PLMN; circuitry configured to receive information indicating that the first PLMN is under a disaster condition; circuitry configured to transmit a registration request to a second PLMN; circuitry configured to receive a registration rejection message from the second PLMN; circuitry configured to receive, from the second PLMN, information indicating that the restriction on the second RAT is not applicable for the first PLMN; and circuitry configured to register with the first PLMN on the second RAT.
  12. 12 . The WTRU of claim 11 , wherein the circuitry configured to receive the information indicating that the first PLMN is under the disaster condition is configured to receive the information indicating that the first PLMN is under the disaster condition in a broadcast from the second PLMN.
  13. 13 . The WTRU of claim 12 , wherein the broadcast comprises a system information block (SIB).
  14. 14 . The WTRU of claim 13 , further comprising circuitry configured to receive an additional SIB that includes information indicating that the restriction on the second RAT is not applicable for the first PLMN, and location information, responsive to the broadcast SIB.
  15. 15 . The WTRU of claim 11 , wherein the registration request to the second PLMN indicates a request for disaster roaming service.
  16. 16 . The WTRU of claim 11 , wherein the registration request to the second PLMN indicates a request for normal service.
  17. 17 . The WTRU of claim 11 , wherein the registration rejection message from the second PLMN includes information indicating that the restriction on the second RAT is not applicable to the WTRU for the first PLMN.
  18. 18 . The WTRU of claim 17 , wherein the information indicating that the first PLMN is under the disaster condition includes location information, wherein the information indicating that the restriction on the second RAT is not applicable to the WTRU for the first PLMN is applicable within a geographic area that is based on the location information.
  19. 19 . The WTRU of claim 11 , wherein the first RAT comprises a 5G RAT.
  20. 20 . The WTRU of claim 11 , wherein the second RAT comprises a 4G RAT.

Description

BACKGROUND Roaming services may provide connectivity for wireless transmit/receive units (WTRUs), e.g., in areas where a primary network operator lacks coverage. Allowing the WTRU to have unrestricted use of Radio Access Technologies (RAT) during roaming may, in some cases, result in technical challenges, such as interoperability issues, quality of service concerns and network congestion concerns. Accordingly, in some cases, a WTRU may be restricted from using a particular RAT, e.g., when roaming. SUMMARY Some implementations provide systems, methods, and devices for handling of RAT utilization under disaster conditions. The WTRU registers with a first public land mobile network (PLMN) on a first radio access technology (RAT). The WTRU receives, from the first PLMN, information indicating that a restriction on a second RAT is applicable for the first PLMN. The WTRU receives information indicating that the first PLMN is under a disaster condition. The WTRU transmits a registration request to a second PLMN. The WTRU receives a registration rejection message from the second PLMN. The WTRU receives, from the second PLMN, information indicating that the restriction on the second RAT is not applicable for the first PLMN. The WTRU registers with the first PLMN on the second RAT. BRIEF DESCRIPTION OF THE DRAWINGS A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, wherein like reference numerals in the figures indicate like elements, and wherein: FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented; FIG. 1B is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment; FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A according to an embodiment; FIG. 1D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1A according to an embodiment; FIG. 2 is a message sequence chart illustrating an example procedure for delivery and handling of information for RAT utilization under disaster handling conditions; FIG. 3 is a flow chart illustrating an example method for RAT utilization handling under disaster conditions, with pre-disaster configuration; FIG. 4 is a message sequence chart illustrating aError! Reference source not found.n example procedure for a WTRU which receives RAT utilization information applicability per PLMN after a disaster has occurred; FIG. 5 is a flow chart illustrating an example method 500 for RAT utilization handling under disaster conditions, with post-disaster provisioning; and FIG. 6 is a flowchart illustrating an example method for handling of RAT utilization under disaster conditions. DETAILED DESCRIPTION Some implementations provide a method for use in a wireless transmit/receive unit (WTRU). The WTRU registers with a first public land mobile network (PLMN) on a first radio access technology (RAT). The WTRU receives, from the first PLMN, information indicating that a restriction on a second RAT is applicable for the first PLMN. The WTRU receives information indicating that the first PLMN is under a disaster condition. The WTRU transmits a registration request to a second PLMN. The WTRU receives a registration rejection message from the second PLMN. The WTRU receives, from the second PLMN, information indicating that the restriction on the second RAT is not applicable for the first PLMN. The WTRU registers with the first PLMN on the second RAT. In some implementations, the information indicating that the first PLMN is under the disaster condition is received in a broadcast from the second PLMN. In some implementations, the broadcast comprises a system information block (SIB). Some implementations also include requesting an additional SIB that includes information indicating that the restriction on the second RAT is not applicable for the first PLMN, and location information, responsive to the broadcast SIB. In some implementations, the registration request to the second PLMN indicates a request for disaster roaming service. In some implementations, the registration request to the second PLMN indicates a request for normal service. In some implementations, the registration rejection message from the second PLMN includes information indicating that the restriction on the second RAT is not applicable to the WTRU for the first PLMN. In some implementations, the information indicating that the first PLMN is under the disaster condition includes location information, wherein the information indicating that the restriction on the second RAT is not applicable to the WTRU for the first PL