Apparatus to enable fallback to circuit switched domain from packet switched domain
First Claim
1. A wireless transmit/receive unit (WTRU), comprising:
- a transmitter configured to transmit a service request to an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN); and
a processor, coupled to the transmitter, the processor configured to implement a Non-Access Stratum (NAS) layer to;
determine to request a Circuit Switched (CS) fallback;
generate, after the determining to request the CS fallback, the service request including a request to perform the CS fallback and CS service information; and
receive, from another layer of the WTRU, an indication of a mode change to one of;
an A/Gb mode or an Iu mode, as a notification of completion of the CS fallback.
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Accused Products
Abstract
An apparatus is used to perform a Circuit Switched (CS) fallback in wireless communications. The Non-Access Stratum (NAS) of the apparatus determines whether to perform a CS fallback based on an Internet Protocol (IP) Multimedia Subsystem (IMS) registration status, and sends a service request indicating a request to perform the CS fallback when the WTRU is attached to a CS domain. The apparatus also includes an Access Stratum (AS) that receives the CS service request from the NAS, sends an indication of the CS service request in a Radio Resource Control (RRC) message to an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), wherein the RRC message includes CS service information, and receives a handover command in response to the CS service request.
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Citations
20 Claims
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1. A wireless transmit/receive unit (WTRU), comprising:
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a transmitter configured to transmit a service request to an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN); and a processor, coupled to the transmitter, the processor configured to implement a Non-Access Stratum (NAS) layer to; determine to request a Circuit Switched (CS) fallback; generate, after the determining to request the CS fallback, the service request including a request to perform the CS fallback and CS service information; and receive, from another layer of the WTRU, an indication of a mode change to one of;
an A/Gb mode or an Iu mode, as a notification of completion of the CS fallback. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for circuit switched (CS) fallback performed by a wireless transmit/receive unit (WTRU) comprising a transmitter, and a processor coupled to the transmitter, the processor configured to implement a Non-Access Stratum (NAS) layer, the method comprising:
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determining, by the NAS layer, to request a CS fallback; after the determining to request the CS fallback, generating, by the NAS layer, a service request including a request to perform the CS fallback and CS service information; transmitting the service request, by the transmitter, to an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN); and receiving, by the NAS layer from another layer of the WTRU, an indication of a mode change to one of;
an A/Gb mode or an Iu mode, as a notification of completion of the CS fallback. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A wireless transmit/receive unit (WTRU), comprising:
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a transmitter; a receiver; and a processor, coupled to the transmitter and the receiver, configured to implement a Non-Access Stratum (NAS), wherein the NAS is configured to; determine whether to request a Circuit Switched (CS) fallback; and responsive to determining to request the CS fallback, generate a service request including a request to perform the CS fallback, wherein the service request includes CS service information, wherein the transmitter is configured to transmit the service request to an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), and wherein the receiver is configured to receive a Radio Resource Control (RRC) message including redirection information in response to the service request. - View Dependent Claims (19, 20)
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Specification