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WO2017151259A1 - Gestion d'état améliorée de repli par commutation de circuits (csfb) - Google Patents

Gestion d'état améliorée de repli par commutation de circuits (csfb) Download PDF

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Publication number
WO2017151259A1
WO2017151259A1 PCT/US2017/015788 US2017015788W WO2017151259A1 WO 2017151259 A1 WO2017151259 A1 WO 2017151259A1 US 2017015788 W US2017015788 W US 2017015788W WO 2017151259 A1 WO2017151259 A1 WO 2017151259A1
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WO
WIPO (PCT)
Prior art keywords
network
communication session
state
call
csfb
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2017/015788
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English (en)
Inventor
Deepak DASH
Nitin GOWDA BASAVARAJAPPA
Anuroop SOBHAN MADUPU
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Intel IP Corp
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Intel IP Corp
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Filing date
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Publication of WO2017151259A1 publication Critical patent/WO2017151259A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0022—Control or signalling for completing the hand-off for data sessions of end-to-end connection for transferring data sessions between adjacent core network technologies
    • H04W36/00224—Control or signalling for completing the hand-off for data sessions of end-to-end connection for transferring data sessions between adjacent core network technologies between packet switched [PS] and circuit switched [CS] network technologies, e.g. circuit switched fallback [CSFB]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/14—Reselecting a network or an air interface
    • H04W36/144—Reselecting a network or an air interface over a different radio air interface technology
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0066—Transmission or use of information for re-establishing the radio link of control information between different types of networks in order to establish a new radio link in the target network
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W60/00—Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
    • H04W60/005—Multiple registrations, e.g. multihoming
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/19—Connection re-establishment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/27—Transitions between radio resource control [RRC] states

Definitions

  • the present disclosure relates to circuit switched fall back (CSFB) enabled long term evolution (LTE) networks and in particular, to a method for improved state handling for CSFB procedure in CSFB enabled LTE networks.
  • CSFB circuit switched fall back
  • LTE long term evolution
  • a mobile network may support communication with mobile devices.
  • a mobile device may experience degradation in performance for any number of reasons.
  • the mobile device may be out of coverage of base stations in the network.
  • the network may experience congestion or other issues.
  • a performance of the device and/or a user experience may suffer. Accordingly, there is a general need for methods and systems for improving performance in these and other scenarios.
  • Fig. 1 illustrates a simplified block diagram of a circuit switched fall back (CSFB) enabled packet switched (PS) network, according to one embodiment of the disclosure.
  • Fig. 2 illustrates a simplified block diagram of a circuit switched fall back (CSFB) enabled long term evolution (LTE) network, according to one embodiment of the disclosure.
  • CSFB circuit switched fall back
  • FIG. 3 illustrates a block diagram of an apparatus for use in a user equipment (UE) in a CSFB enabled PS network, according to various embodiments described herein.
  • UE user equipment
  • Fig. 4a illustrates the events that may occur and/or the operations that may be performed related to a reception of a non-EPS service request for initiating a mobile originating (MO) CS voice call, from the connection management (CM) sub-layer within a user equipment (UE) while the UE operates in a failure state, according to an embodiment of the disclosure.
  • MO mobile originating
  • CM connection management
  • Fig. 4b illustrates the events that may occur and/or the operations that may be performed related to a reception of a CS domain paging for initiating a mobile terminating (MT) CS voice call at a user equipment (UE) while the UE operates in EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state, according to an embodiment of the disclosure.
  • MT mobile terminating
  • UE user equipment
  • FIG. 5 illustrates a flow chart of a method for a UE in a CSFB enabled PS network, according to one embodiment of the disclosure.
  • Fig. 6 illustrates, example components of a User Equipment (UE) device, for the various embodiments described herein.
  • UE User Equipment
  • FIG. 7 is a functional diagram of a 3GPP long term evolution (LTE) network, in accordance with some embodiments.
  • LTE long term evolution
  • an apparatus for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled long term evolution (LTE) network comprises one or more processors; and a memory including instructions comprising operations, for execution via the one or more processors, to determine that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE and determine whether the UE is in a failure state comprising an evolved packet system mobility management (EMM)-REGISTERED.ATTEMPTING-TO-UPDATE-MM or an EMM-REG ISTERED.PLMN-SEARCH or an EMM-REGISTERED.
  • EMM evolved packet system mobility management
  • the instructions comprise further operations to attempt to select an available non-LTE network that supports CS services, when the UE is in the failure state, by providing, via the one or more processors, one or more service related messages to a base station of the available non-LTE network as part of an establishment of a CS communication session comprising the MO CS call.
  • an apparatus for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled packet-switched (PS) network comprises one or more processors; and a memory including instructions comprising operations, for execution via the one or more processors, to determine that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE and determine whether the UE is in a failure state comprising a first state wherein the UE is successfully registered for a PS communication session with a PS-domain associated with the CSFB enabled PS network, and wherein the UE is not registered for a CS-communication session with a CS-domain associated with the CSFB enabled PS network, at least partly due to a temporary issue associated with the CS-domain; or a second state wherein the UE is searching for public land mobile networks (PLMNs); or a third state wherein PLMNs; or a third state wherein
  • the instructions comprise further operations to attempt to select an available CS network, when the UE is in the failure state, by providing, via the one or more processors, one or more service related messages to a CS base station of the available CS network as part of an establishment of the CS communication session comprising the MO CS call.
  • a method for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled packet-switched (PS) network comprises determining that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE, at a processing circuit and determining, at the processing circuit, whether the UE is in a failure state comprising a first state wherein the UE is successfully registered for a PS communication session with a PS-domain associated with the CSFB enabled PS network, and wherein the UE is not registered for a CS- communication session with a CS-domain associated with the CSFB enabled PS network, at least partly due to a temporary issue associated with the CS-domain; or a second state wherein the UE is searching for public land mobile networks (PLMNs); or a third state wherein a cell selected by the UE is known not to be
  • PLMNs public land mobile networks
  • the method further comprises attempting to select an available CS network, by providing , by the processing circuit, one or more service related messages to a CS base station of the available CS network as part of an establishment of the CS communication session comprising the MO CS call, when the UE is in the failure state.
  • a component can be a processor (e.g., a microprocessor, a controller, or other processing device), a process running on a processor, a controller, an object, an executable, a program, a storage device, a computer, a tablet PC and/or a user equipment (e.g., mobile phone, etc.) with a processing device.
  • a processor e.g., a microprocessor, a controller, or other processing device
  • a process running on a processor e.g., a microprocessor, a controller, or other processing device
  • an object running on a server and the server
  • a user equipment e.g., mobile phone, etc.
  • an application running on a server and the server can also be a component.
  • One or more components can reside within a process, and a component can be localized on one computer and/or distributed between two or more computers.
  • a set of elements or a set of other components can be described herein, in which the term "set"
  • these components can execute from various computer readable storage media having various data structures stored thereon such as with a module, for example.
  • the components can communicate via local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network, such as, the Internet, a local area network, a wide area network, or similar network with other systems via the signal).
  • a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network, such as, the Internet, a local area network, a wide area network, or similar network with other systems via the signal).
  • a component can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors.
  • the one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application.
  • a component can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processors therein to execute software and/or firmware that confer(s), at least in part, the functionality of the electronic components.
  • a mobile device may experience degradation in performance for any number of reasons.
  • a circuit switched fall back (CSFB) enabled packet switched (PS) network such as a CSFB enabled 3GPP long term evolution (LTE) network
  • the network comprises a PS-portion (or PS-domain) that handles PS communication sessions or PS services (i.e., data services) associated with the network and a circuit-switched (CS) portion (or CS-domain) that handles CS communication sessions or CS services (i.e., voice calls) associated with the network.
  • PS-portion or PS-domain
  • CS circuit-switched
  • CS services i.e., voice calls
  • a typical PS network supports only PS services.
  • a voice call (also referred to as CS call or a CS voice call throughout the disclosure) is initiated in a CSFB enabled PS network
  • the network may cause the voice call to be transferred from the PS portion of the network to the CS portion of the network. Transferring a voice call in this manner is referred to as the CSFB.
  • a core network associated with the CSFB enabled PS network allows different radio access technologies (RATs) to work together in an integrated manner, in order to support both PS services and CS services associated with the network.
  • RATs radio access technologies
  • the PS-domain can include a 3GPP LTE network that supports only PS services and the CS-domain can include universal mobile telecommunications system (UMTS), global system for mobile communications (GSM) etc. that supports CS services.
  • UMTS universal mobile telecommunications system
  • GSM global system for mobile communications
  • the PS-domain and the CS domain can include other RATs.
  • the LTE coverage should be overlapped by either the GSM or the UMTS coverage, in the CSFB enabled 3GPP LTE network.
  • a user equipment (UE) that is camped on to the CSFB enabled PS network may support multiple RATs and is known as a multi-mode UE.
  • UE user equipment
  • a CSFB enabled multi-mode UE has the capability to switch from the PS portion to the CS portion of the CSFB enabled PS network in order to send/receive CS voice calls using the CSFB procedure.
  • the CSFB enabled PS network redirects the multi-mode UE from the PS portion of the network to the CS portion of the network.
  • these conditions include states or sub-states associated with the UE, referred to herein as failure states.
  • the states include EPS mobility management (EMM) states associated with the UE, as defined in the 3GPP standard for LTE networks and the failure states includes one or more specific EMM states associated with the UE.
  • EMM EPS mobility management
  • a MO CS voice call e.g., user triggered voice call
  • a MT CS voice call at the UE will be rejected or delayed due to additional signaling overhead between the UE and the network to first recover from the failure state before the CS call request can be processed, thus resulting in a dropped phone call. That is, in typical CSFB enabled PS network, for example, the CSFB enabled 3GPP LTE network, a CS voice call through CSFB procedure will be successful only when the UE is in a non-failure state associated therewith.
  • the failure states associated with the UE does not indicate unavailability of CS-domain services for UE in served CSFB enabled PS network or a served LTE cell. Rather these states indicate, in some embodiments, a temporary failure due to race condition with other non-access stratum (NAS) procedure or temporary failure at access stratum (AS) due to bad radio conditions of the serving CSFB enabled PS network or the serving LTE cell. Therefore, in such embodiments, there is a high possibility to make mobile originated CS calls and mobile terminated CS calls successful, even when the UE is in a failure state.
  • NAS non-access stratum
  • AS access stratum
  • Fig. 1 illustrates a simplified block diagram of a circuit switched fall back (CSFB) enabled packet switched (PS) network 100, according to one embodiment of the disclosure.
  • the CSFB enabled PS network 100 comprises a UE 102, a PS base station 104 and a core network 1 12.
  • the core network 1 12 comprises a PS core 106 configured to handle PS communication sessions or services (data services) associated with the CSFB enabled PS network 100 and a CS core 108 configured to handle circuit switched (CS) communication sessions or services (i.e., voice call) associated with the CSFB enabled PS network 100.
  • the CSFB enabled PS network 100 further comprises a CS base station 1 1 0 associated with the CS core 1 08 and configured to facilitate CS services associated with the CSFB enabled PS network 100.
  • CS base station referred to herein comprises base stations supporting CS services and in some instances, PS services.
  • the PS base station 104 and the PS core 106 comprises a PS portion 1 16 of the CSFB enabled PS network 100
  • the CS base station 1 10 and the CS core 108 comprises a CS portion 1 18 of the CSFB enabled PS network 100
  • the CS base station 1 1 0 and the CS core 108 can handle both the CS services and PS services.
  • the PS portion 1 16 may support a packet service such as Evolved Packet Service (EPS) and the PS communication session may include an EPS communication session.
  • EPS Evolved Packet Service
  • the CS portion 1 18 may support both EPS services and non-EPS services and the CS communication session may include a non-EPS communication session.
  • the CS portion 1 18 may comprise one or more CS networks that support both CS and in some instances, PS services.
  • the CSFB enabled PS network 100 further comprises an interface 1 14 that couples the PS core 106 and the CS core 108.
  • the interface 1 14 facilitates the PS portion 1 16 of the network 100 and the CS portion 1 18 of the network 100 to work in an integrated manner to provide both PS services and CS services to the UE 1 02.
  • the UE 102 when camped on to the PS portion 1 16 of the CSFB enabled PS network 100, is configured to be registered to both the PS core 106 and the CS core 108.
  • the CSFB enabled PS network 1 00 allows different radio access technologies (RATs) to work together in an integrated manner, in order to support both PS services and CS services associated with the network.
  • the CSFB enabled PS network 100 can comprise a CSFB enabled 3GPP long term evolution (LTE) network.
  • the CSFB enabled LTE network can comprise a 3GPP LTE network as the PS portion and a non-LTE RAT as the CS portion.
  • the non- LTE RAT can comprise universal terrestrial radio access network (UTRAN) or 3G network.
  • the non-LTE RAT can comprise a GSM EDGE radio access network (GERAN) or 2G network. Further, in other embodiments, the non-LTE RAT can comprise other RATs that supports CS services and in some instances, PS services.
  • GERAN GSM EDGE radio access network
  • 2G network 2G network.
  • the non-LTE RAT can comprise other RATs that supports CS services and in some instances, PS services.
  • the UE 102 when the UE 102 is camped on to the PS portion 1 16 of the CSFB enabled PS network 1 00, the UE 102 is configured to establish a PS communication session or a CS communication session or both, based on a state or sub-state associated with the UE 102.
  • these states correspond to the EPS mobility management (EMM) states associated with a UE.
  • EMM states of the UE result from mobility management (MM) procedures associated with the UE, e.g., attach and tracking area update (TAU) procedures.
  • the state associated with the UE 102 comprises a failure state and a normal state (which may be a non- failure state in some cases).
  • the UE 102 is configured to determine a state associated with the UE 102, prior to establishing a CS communication (i.e., an mobile originated (MO) voice call or a mobile terminated (MT) voice call) for the UE 102. As an example, it may be determined whether the UE 102 is to operate in the failure state and/or normal state based at least partly on a network condition of the PS portion 1 16, such as network congestion and/or other condition.
  • a network condition of the PS portion 1 16 such as network congestion and/or other condition.
  • the UE 102 may be determined that the UE 102 is to operate in the failure state and/or normal state based at least partly on issues related to an air interface between the UE 102 and the PS base station 104, network coverage of the UE 102 and/or other performance measurement related to a wireless link between the UE 102 and the PS base station 104.
  • the failure state associated with the UE 1 02 can comprises one or more failure states.
  • a first failure state comprises a state in which the UE 102 is successfully registered for a PS
  • the UE 102 may enter the first failure state due to temporary issue of the interface 1 14 between the PS core 106 and the CS core 108.
  • the first failure state can comprise an EMM-REG ISTERED.ATTEMPTING-TO-UPDATE-MM state of the UE.
  • a second failure state of the UE 102 comprises a state in which the UE 102 is searching for public land mobile networks (PLMNs).
  • the UE 102 may enter the second failure state due to a network coverage issue of the UE 102 (with the PS portion 1 16) or due to a rejection from a current PLMN the UE 102 is associated with.
  • other factors can also cause the UE 102 to operate in the second failure state.
  • the second failure state can comprise an EMM-REGISTERED. PLMN-SEARCH state of the UE.
  • a third failure state of the UE 102 comprises a state in which the UE 102 is searching for a suitable cell.
  • the UE 102 may enter the third failure state when a cell selected by the UE is known not to be able to provide normal service due to a high-load situation or other factors associated with the network (e.g., the PS portion 1 16).
  • the third failure state can comprise an EMM-REGISTERED. LIMITED- SERVICE state of the UE.
  • a normal state (or non-failure state) associated with the UE 102 comprises a state in which the UE 102 is successfully registered for a PS communication session with the PS core 106 associated with the CSFB enabled PS network 100, and for a CS-communication session with the CS core 108 associated with the CSFB enabled PS network 100 and has no other network related issues.
  • the normal state can comprise an EMM-REGISTERED. NORMAL-SERVICE state of the UE.
  • the UE 102 in order to establish a CS communication session comprising a MO CS voice call or an MT CS voice call for the UE 102 that is camped on to the PS portion 1 16, the UE 102 is configured to determine that a CS communication session (i.e., the MO CS voice call or the MT CS voice call) is to be established.
  • a CS communication session i.e., the MO CS voice call or the MT CS voice call
  • the determination that the CS communication session i.e., mobile originated (MO) voice call
  • CM connection management
  • the determination that the CS communication session comprising the MT CS call is to be established may be based on a CS domain paging indicating that an MT CS call is to be established for the UE 102, received from the core network 1 12 associated with the CSFB enabled PS network 100.
  • the CS communication session may include a non-EPS communication session, although embodiments are not limited as such, and any suitable CS
  • the UE 102 Upon determining that the CS communication session is to be established, the UE 102 is configured to determine a state (e.g., the EMM state in 3GPP) associated with the UE. For example, the UE 102 is configured to determine if the UE 102 is operating in the first failure state, the second failure state, the third failure state or the normal state.
  • a state e.g., the EMM state in 3GPP
  • the UE 102 if it is determined that the UE 1 02 is operating in the normal state (or the non-failure state), the UE 102 is configured to transmit a message, for example, an extended service request message, to the PS base station 104, in order to establish the CS communication session (i.e., the MO CS voice call or the MT CS voice call).
  • the extended service request message may include status information for a PS communication session and may further include an indicator that the CS communication session is to be established.
  • the CS communication session is established by switching the UE 102 from the PS portion 1 16 of the network 100 to the CS portion 1 18 of the network 100.
  • the switching the UE 1 02 from the PS portion 1 1 6 to the CS portion 1 1 8 is initiated by the network (e.g., the PS core 106).
  • the network e.g., the PS core 106.
  • the CS communication session i.e., the MO CS voice call or the MT CS voice call
  • the CSFB procedure comprises switching the UE from an LTE network to a non-LTE RAT (e.g., UTRAN or GERAN), in order to establish the CS communication session.
  • the switching of the UE from an LTE network to the non-LTE RAT is initiated by the LTE network, for example, by a mobility management entity (MME) associated with the LTE network.
  • MME mobility management entity
  • the UE 1 02 is configured to attempt to select an available CS network (e.g., a non-LTE RAT) in order to establish the CS communication session (i.e., the MO voice call).
  • the UE 102 is configured to transmit one or more service related messages to a CS base station of the CS network that facilitates standard mobility management (MM) procedures, in order to establish the CS communication session.
  • MM mobility management
  • the one or more service related messages can include a CS registration message to establish registration with the CS network, in order to establish the CS communication session comprising the MO CS voice call.
  • the UE 102 may transmit, when it is determined that a group of one or more CS base stations is available, a service related message for the CS connection to at least one of the CS base stations in the group.
  • the available CS base stations may be part of the CS portion 1 18 of the CSFB enabled PS network 100. However, in other embodiments, the available CS base stations may not be inclusive to the CS portion 1 18 of the CSFB enabled PS network 100.
  • the UE 102 is further configured to refrain from transmission of messages (e.g., the extended service request message to initiate the CSFB procedure) to the PS base station 104 for the establishment of the CS
  • messages e.g., the extended service request message to initiate the CSFB procedure
  • the network e.g., the PS core 106
  • the network is not involved in initiating the CS communication session and is initiated by the UE 102 itself.
  • the UE when the UE is in a failure state comprising the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM or the EMM-REGISTERED. PLMN- SEARCH or the EMM-REGISTERED. LIMITED-SERVICE, the UE is configured to select an available UTRAN or a GERAN network (i.e., legacy networks), in order to establish the CS communication session (i.e., the MO CS voice call).
  • a GERAN network i.e., legacy networks
  • the UE 102 is configured to determine an availability of one or more CS networks, prior to selecting a CS network for the CS communication session.
  • CS networks may include UMTS, GERAN and/or other CS network which may or may not operate in accordance with the 3GPP standard.
  • the determination of the availability of the CS network(s) may be based at least partly on a monitoring for transmissions by CS networks. For instance, the UE 102 may monitor for such transmissions by attempting to receive a signal (such as a beacon signal or other) from a CS network. Accordingly, the UE 102 may attempt to detect a presence of one or more CS base stations based at least partly on a monitoring, by the UE 102, for CS network signals.
  • a signal such as a beacon signal or other
  • the UE 102 may attempt to determine an availability of at least one CS base station to support the CS communication session.
  • the UE 202 may enter the first failure state due to temporary issue of the interface 1 14 between the PS core 106 and the CS core 108.
  • the CS core 1 08 may not be able to provide an MT CS paging message to the UE 1 02, in order to establish a CS communication session comprising the MT CS voice call.
  • the CS core 1 08 is configured to provide a paging message (e.g., the MT CS paging) to the UE 102 via the PS core 106, with the IMSI identifier that identifies the UE 1 02, in order to initiate a re-registration of the UE 102 with the CS core 108.
  • a paging message e.g., the MT CS paging
  • the UE 202 can receive the MT CS paging message that indicates that an MT voice call is to be established for the UE 102, even when the UE 102 is in the first failure state.
  • the UE 102 upon receiving the MT CS paging, when the UE 102 is in the first failure state, the UE 102 is configured to provide/receive one or more registration related messages to the core network 1 12, in order to register (or reregister) the UE 102 with the PS core 1 06 and the CS core 1 08.
  • the UE 102 Upon completion of the re-registration or registration procedure, the UE 102 is establish the MT voice call through appropriate CSFB procedure.
  • the UE 102 is configured to provide an extended service request message comprising an indicator that the CS communication session comprising the MT CS voice call is to be established, in order to initiate the CSFB procedure.
  • Fig. 2 illustrates a simplified block diagram of a circuit switched fall back (CSFB) enabled long term evolution (LTE) network 200, according to one embodiment of the disclosure.
  • the CSFB enabled LTE network 200 depicts one possible way of implementation of the CSFB enabled PS network 100 in Fig. 1 .
  • the CSFB enabled LTE network 200 comprises a UE 202, an EUTRAN (or eNodeB) 204 and a core network 21 2.
  • the core network 212 comprises a mobility management entity (MME) 206 configured to handle PS communication sessions or services (data services) associated with the CSFB enabled LTE network 200 and a non-LTE core 207 configured to handle circuit switched (CS) communication sessions or services (i.e., voice call) associated with the CSFB enabled LTE network 200.
  • MME mobility management entity
  • CS circuit switched
  • the CSFB enabled LTE network 200 further comprises a non-LTE base station 210 associated with the non-LTE core 207 and configured to facilitate CS services associated with the CSFB enabled PS network 200.
  • the non- LTE core 207 and the non-LTE base station 21 0 facilitates both PS services and CS services.
  • the EUTRAN 204 and the MME 206 comprises an LTE network 21 6 which forms a PS portion of the CSFB enabled LTE network 200
  • the non-LTE base station 210 and the non-LTE core 207 comprises a legacy network 21 8, which forms a CS portion of the CSFB enabled LTE network 200
  • the legacy network 218 can comprise one or more legacy networks or CS networks, for example, UTRAN (i.e., 3G), GERAN (i.e., 2G) etc.
  • UTRAN i.e., 3G
  • GERAN i.e., 2G
  • other CS networks can also be part of the legacy network 21 8, in other embodiments.
  • the non-LTE base station 210 can comprise one or more base stations associated with the one or more legacy networks, for example, GERAN, UTRAN etc.
  • the non-LTE core 207 comprises an MSC server 208 configured to handle CS services associated with the legacy network 218 and a serving GPRS support node (SGSN) 209 configured to handle PS services associated with the legacy network 218.
  • the CSFB enabled LTE network 200 further comprises an SGs interface 214 that couples the MME 206 and the MSC server 208.
  • the SG interface 214 facilitates the LTE network 216 and the legacy network 218 of the CSFB enabled LTE network 200 to work in an integrated manner to provide both PS services and CS services to the UE 202.
  • the UE 202 when camped on to the LTE network 21 6 of the CSFB enabled LTE network 200, is configured to be registered to both the MME 206 and the MSC server 208.
  • the UE 202 when the UE 202 is camped on to the LTE network 21 6 of the CSFB enabled LTE network 200, the UE 202 is configured to establish a PS communication session or a CS communication session or both, based on a state or sub-state associated with the UE 202. In some embodiments, these states correspond to the EPS mobility management (EMM) states associated with the UE 202. In some embodiments, the EMM states of the UE 202 result from mobility management (MM) procedures associated with the UE 202, e.g., attach and tracking area update (TAU) procedures.
  • MM mobility management
  • TAU attach and tracking area update
  • the state associated with the UE 202 comprises a failure state and a normal state (which may be a non-failure state in some cases).
  • the UE 202 is configured to determine a state associated with the UE 202, prior to establishing a CS communication (i.e., a mobile originating (MO) CS voice call or mobile terminating (MT) CS voice call) for the UE 202.
  • a CS communication i.e., a mobile originating (MO) CS voice call or mobile terminating (MT) CS voice call
  • the failure state associated with the UE 202 comprises one or more failure states, for example, a first failure state, a second failure state and a third failure state.
  • the first failure state can comprise an EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state of the UE 202.
  • the UE 202 in the EMM-REG ISTERED.ATTEMPTING-TO-UPDATE-MM state, the UE 202 is successfully registered for a PS communication session with the MME 206 not registered for a CS-communication session with the MSC server 208.
  • the UE 202 may enter the EMM-REGISTERED. ATTEMPTING-TO- UPDATE-MM state due to temporary issue of the SG interface 214 between the MME 206 and the MSC server 208.
  • the UE 202 can enter the EMM-REG ISTERED.ATTEMPTING-TO-UPDATE-MM state when a combined attach procedure or a combined tracking area update (TAU) procedure for the UE 202 in the CSFB enabled LTE network 200 is successful for EPS services only, as indicated in the 3GPP technical specification (TS) 24.301 .
  • TAU tracking area update
  • the UE 202 enters the EMM-REG ISTERED.ATTEMPTING-TO-UPDATE-MM state when an attach accept message associated with the combined attach procedure or a TAU accept message associated with the combined TAU procedure, returns EMM cause values #16 (MSC temporarily not reachable), #17 (Network failure) or # 22 (Congestion), as indicated in the 3GPP TS 24.301 .
  • EMM cause values #16 MSC temporarily not reachable
  • #17 Network failure
  • # 22 Congestion
  • other factors can also cause the UE 202 to operate in the EMM-REG ISTERED.ATTEMPTING-TO- UPDATE-MM state.
  • the second failure state of the UE 202 can comprise an EMM-REGISTERED. PLMN-SEARCH state of the UE 202.
  • the UE 202 in the EMM-REGISTERED. PLMN-SEARCH state, the UE 202 is searching for public land mobile networks (PLMNs).
  • PLMNs public land mobile networks
  • the UE 202 may enter the EMM-REGISTERED. PLMN-SEARCH state due to a network coverage issue of the UE 202 or due to a rejection from a current PLMN the UE 202 is associated with.
  • the UE 202 can enter the EMM- REGISTERED.
  • the PLMN-SEARCH state if tracking area updating/combined tracking area updating of the UE 202 cannot be accepted by the network 216 and the MME 206 sends a TRACKING AREA UPDATE REJECT message to the UE 202 including an appropriate EMM cause value, for example, #13 (roaming not allowed in this tracking area), as indicated in the3GPP TS 24.301 .
  • the UE 202 can enter the EMM-REGISTERED.
  • the PLMN-SEARCH state if a service request from the UE 202 cannot be accepted by the network 216 and the MME 206 shall return a SERVICE REJECT message to the UE 202 including an appropriate EMM cause value, for example, #13 (roaming not allowed in this tracking area), as indicated in the3GPP TS 24.301 . However, in other embodiments, other factors can also cause the UE 202 to operate in the EMM-REGISTERED. PLMN- SEARCH state. [0042] In some embodiments, the third failure state of the UE 202 can comprise an EMM-REGISTERED.LIMITED-SERVICE state.
  • the UE 202 in the EMM- REGISTERED.LIMITED-SERVICE state, the UE 202 is searching for a suitable cell. In some embodiments, the UE 202 may enter the EMM-REGISTERED.LIMITED- SERVICE state when a cell selected by the UE is known not to be able to provide normal service due to a high-load situation or other factors associated with the LTE network 216.
  • the UE 202 can enter the EMM-REGISTERED.LIMITED-SERVICE state if tracking area updating/combined tracking area updating of the UE 202 cannot be accepted by the network 216 and the MME 206 sends a TRACKING AREA UPDATE REJECT message to the UE 202 including an appropriate EMM cause value, for example, #15 (no suitable cells in the tracking area), #25 (not authorized for this CSG), as indicated in the3GPP TS 24.301 .
  • EMM cause value for example, #15 (no suitable cells in the tracking area), #25 (not authorized for this CSG), as indicated in the3GPP TS 24.301 .
  • the UE 202 can enter the EMM-REGISTERED.LIMITED-SERVICE state, if a service request from the UE 202 cannot be accepted by the network 216 and the MME 206 shall return a SERVICE REJECT message to the UE 202 including an appropriate EMM cause value, for example, #15 (no suitable cells in the tracking area), #25 (not authorized for this CSG), as indicated in the3GPP TS 24.301 .
  • EMM cause value for example, #15 (no suitable cells in the tracking area), #25 (not authorized for this CSG), as indicated in the3GPP TS 24.301 .
  • other factors can also cause the UE 202 to operate in the EMM-REGISTERED.LIMITED-SERVICE state.
  • a normal state (or non-failure state) associated with the UE 202 can comprise an EMM-REGISTERED. NORMAL-SERVICE state.
  • the UE 202 is configured to determine that a CS communication session is to be established, in order to establish a mobile originated (MO) CS voice call or an MT CS voice call for the UE 202 that is camped on to the LTE network 216.
  • the determination that the CS communication session (i.e., the MO CS voice call) is to be established may be based at least partly on a service request generated, at the UE 202, by a connection management (CM) sublayer of the UE 202.
  • CM connection management
  • the determination that the CS communication session comprising the MT CS call is to be established may be based on a CS domain paging indicating that an MT CS call is to be established for the UE 202, received from the core network 212 associated with the CSFB enabled LTE network 200.
  • the CS communication session may include a non-EPS communication session, although embodiments are not limited as such, and any suitable CS communication session may be used.
  • the UE 202 is configured to determine the EMM state associated with the UE 202. For example, the UE 202 is configured to determine if the UE 102 is operating in the first failure state, the second failure state, the third failure state or the normal state.
  • the UE 202 if it is determined that the UE 202 is operating in the EMM-REGISTERED. NORMAL-SERVICE, the UE 202 is configured to establish the CS communication session (i.e., an MO voice call or a mobile terminating (MT) voice call) through the CSFB procedure.
  • the CSFB procedure comprises switching the UE 202 from the LTE network 216 to the non-LTE network 218.
  • the switching the UE 202 from the LTE network 216 to the non-LTE network 218 is initiated by the LTE network 216 (e.g., the MME 206).
  • the UE 202 in order to establish the MO CS voice call or the MT CS through the CSFB procedure, the UE 202 is configured to transmit a message, for example, an extended service request message to the eNodeB 204.
  • the extended service request message may include status information for a PS
  • the communication session and may further include an indicator that the CS communication session (i.e., the MO CS voice call or the MT CS voice call) is to be established.
  • the determination that the MT CS voice call is established for the UE 202 is made, based on a paging message from the MME.
  • UE 202 if it is determined that UE 202 is operating in the EMM-REGISTERED. ATTEMPTING-TO-UPDATE-MM state or the EMM- REGISTERED. PLMN-SEARCH state or the EMM-REGISTERED. LIMITED-SERVICE state, and it is determined that the UE 202 is configured to establish a CS
  • UE 202 is configured to transmit one or more service related messages to a non-LTE base station (e.g., the non-LTE base station 210) that facilitates standard mobility management (MM) procedures, as part of an establishment of the CS communication session (i.e., the MO CS voice call).
  • a non-LTE base station e.g., the non-LTE base station 210 that facilitates standard mobility management (MM) procedures
  • MM mobility management
  • the UE 202 may transmit, when it is determined that a group of one or more non-LTE base stations (e.g., GERAN, UTRAN etc.) is available, one or more service related messages for the CS connection to at least one of the non-LTE base stations in the group.
  • a group of one or more non-LTE base stations e.g., GERAN, UTRAN etc.
  • the available non- LTE base stations may be part of the non-LTE base stations 210 of the non-LTE network 218. However, in other embodiments, the available non-LTE base stations may not be inclusive to the non-LTE network 218 of the CSFB enabled LTE network 200.
  • the MME 206 is not involved in initiating the CS communication session and is initiated by the UE 202 itself.
  • the UE 202 is further configured to refrain from transmission of messages (e.g., the extended service request message) to the MME 206 for the establishment of the CS communication session through the CSFB procedure.
  • the UE 202 is configured to determine an availability of one or more non-LTE networks, prior to transmitting the one or more service related messages message to the non-LTE base stations of the one or more non-LTE networks.
  • the UE 202 is configured to determine an availability of one or more non-LTE networks, prior to transmitting the one or more service related messages message to the non-LTE base stations of the one or more non-LTE networks.
  • determination of the availability of the non-LTE network(s) may be based at least partly on a monitoring for transmissions by the non-LTE networks.
  • the UE 202 may monitor for such transmissions by attempting to receive a signal (such as a beacon signal or other) from a non-LTE network.
  • the UE 202 may enter the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state due to temporary issue of the SG interface 214 between the MME 206 and the MSC server 208.
  • the MSC server 208 is configured to provide a paging message (i.e., an MT CS paging) to the UE 202 via the MME 206, with the IMSI identifier that identifies the UE 202, in order to initiate a re-registration of the UE 202 with the MSC server 208.
  • a paging message i.e., an MT CS paging
  • the UE 202 is configured to receive the MT CS paging message that indicates that an MT voice call is to be established for the UE 202, even when the UE 202 is in the EMM-REG ISTERED.ATTEMPTING-TO- UPDATE-MM state.
  • the UE 202 upon receiving the MT CS paging, when the UE 202 is in the EMM-REG ISTERED.ATTEMPTING-TO-UPDATE-MM state, the UE 202 is configured to provide/receive one or more registration related messages to the core network 212, in order to register (or re-register) the UE 202 with the MME 206 and the MSC server 208.
  • the UE 202 Upon completion of the re-registration or registration procedure, the UE 202 is configured to establish the MT CS voice call through appropriate CSFB procedure. In some embodiments, the UE 202 is configured to provide a service request message, for example, an extended service request message comprising an indicator that the CS communication session comprising the MT CS voice call is to be established, in order to initiate the CSFB procedure, upon completion of the re-registration procedure.
  • a service request message for example, an extended service request message comprising an indicator that the CS communication session comprising the MT CS voice call is to be established
  • Fig. 3 illustrates a block diagram of an apparatus 300 for use in a user equipment (UE) in a CSFB enabled PS network, according to various embodiments described herein.
  • the apparatus 300 can be included within the UE 102 in Fig. 1 or the UE 202 in Fig. 2.
  • the apparatus 300 is described herein with reference to the UE 102 in Fig. 1 and the UE 202 in Fig. 2.
  • the apparatus 300 includes a receiver circuit 310, a processing circuit 330, and a transmitter circuit 320.
  • the apparatus 300 comprises a memory circuit 340 coupled to the processing circuit 330.
  • the memory circuit 340 comprises a computer readable storage device that includes instructions to be executed by the processor 330.
  • the memory circuit 340 can be an independent circuit and in other embodiments, the memory circuit 340 can be integrated on chip with the processor 330. Alternately, in other embodiments, the instructions to be executed by the processor 330 can be stored on a non-transitory storage medium like CR-ROM, flash drive etc., and can be downloaded to the memory circuit 340 for execution.
  • Each of the receiver circuit 310 and the transmitter circuit 320 are configured to be coupled to one or more antennas, which can be the same or different antenna(s).
  • the receiver circuit 310 and transmitter circuit 320 can have one or more components in common, and both can be included within a transceiver circuit, while in other aspects they are not.
  • the apparatus 300 can be included within a UE, for example, with apparatus 300 (or portions thereof) within a receiver and transmitter or a transceiver circuit of a UE.
  • the processing circuit 330 is configured to determine that a CS communication session comprising the MO voice call or the MT voice call is to be established for the UE.
  • the determination that the CS communication session comprising the MO CS voce call is to be established at the processing circuit 330 may be based at least partly on a service request generated, at the processing circuit 330, by a connection management (CM) sub-layer of the UE.
  • CM connection management
  • the determination that the CS communication session comprising the MT CS call is to be established at the processing circuit 330 may be based on a CS domain paging indicating that an MT CS call is to be established for the UE, received from the core network associated with the CSFB enabled PS network.
  • the processing circuit 330 is further configured to determine a state (e.g., the EMM state in 3GPP) associated with the UE.
  • the processing circuit 330 is configured to determine the state associated with the UE, based on instructions stored in the memory circuit 340.
  • the state associated with the UE can comprise a failure state or a non-failure state.
  • the failure state comprises a first failure state, a second failure state or a third failure state, as explained above with respect to Fig. 1 and Fig. 2.
  • the UE is determined to be in a failure state, if the EMM state associated with the UE comprises an EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state or an EMM- REGISTERED. PLMN-SEARCH state or an EMM-REGISTERED. LIMITED-SERVICE state.
  • a UE is determined to be in a non-failure state (i.e., a normal state), if the EMM state associated with the UE comprises an EMM-REGISTERED. NORMAL- SERVICE state.
  • the state associated with the UE is determined to be a failure state, and it is determined that the CS communication session to be
  • the processing circuit 330 is configured to transmit one or more service request messages to establish standard mobility management (MM) procedures, via the transmitter circuit 320, to a CS base station
  • MM mobility management
  • the processing circuit e.g., the CS base station 1 10 or the non-LTE base station 21 0 of an available CS network (or a non-LTE network), as part of the establishment of the CS communication session comprising the MO CS voice call.
  • the processing circuit e.g., the CS base station 1 10 or the non-LTE base station 21 0 of an available CS network (or a non-LTE network), as part of the establishment of the CS communication session comprising the MO CS voice call.
  • the processing circuit 330 is further configured to process one or more messages (e.g., communication signals) received from the CS base station, via the receive circuit 310, in response to the one or more service request messages, in order to complete the CS communication session.
  • the processing circuit 330 is configured to determine an availability of one or more CS networks (or non-LTE networks), prior to transmitting the one or more service request messages to the CS base station of the one or more CS networks.
  • the determination of the availability of the CS network(s) at the processing circuit 330 may be based at least partly on a monitoring for transmissions by the CS networks, received at the processing circuit 330, via the receive circuit 310.
  • the processing circuit 330 is configured to transmit a message (e.g., an extended service request message) comprising an indicator that the CS communication session is to be established, via the transmit circuit 320, to the PS base station (e.g., the eNodeB 204 in Fig. 2), in order to establish the CS communication session comprising the MT CS voice call through the CSFB procedure.
  • a message e.g., an extended service request message
  • the processing circuit 330 is configured to establish the CS communication session comprising the MO CS voice call or the MT CS voice call through the standard 3GPP circuit switched fall back (CSFB) procedure.
  • the processing circuit 330 is configured to transmit a message (e.g., an extended service request message) comprising an indicator that the CS communication session is to be established, via the transmit circuit 320, to the PS base station (e.g., the eNodeB 204 in Fig. 2), in order to establish the CS communication session comprising the MO CS voice call and the MT CS voice call through the CSFB procedure.
  • a message e.g., an extended service request message
  • Fig. 4a illustrates the events that may occur and/or the operations that may be performed related to a reception of a non-EPS service request for initiating a mobile originating (MO) CS voice call, from the connection management (CM) sub-layer within a user equipment (UE) 400 while the UE operates in a failure state, according to an embodiment of the disclosure.
  • the UE 400 is assumed to be camped onto a CSFB enabled LTE cell or a CSFB enabled PS network.
  • the UE 400 described herein can comprise the UE 102 of Fig. 1 or the UE 202 of Fig. 2.
  • the UE 400 comprises a non-access stratum (NAS) layer and/or module 404, an access stratum (AS) layer and/or module 406 and a user/application layer 402 (which may include and/or be part of a connection
  • NAS non-access stratum
  • AS access stratum
  • user/application layer 402 which may include and/or be part of a connection
  • the UE 400 may include other modules and/or layers.
  • the UE 102 of Fig. 1 or the UE 202 of Fig. 2 may also include same or similar modules/layers.
  • the user/application layer 402 of the UE 400 is configured to initiate a non-EPS service request 41 0 (e.g., a voice call).
  • the non-EPS service request 410 is provided by the user/application layer 402 to the NAS layer 404 of the UE 400.
  • the UE 400 is assumed to be in a failure state in this embodiment.
  • the failure state of the UE 400 can comprise the first failure state, the second failure state or the third failure state, as explained above with respect to Fig. 1 .
  • the failure state of the UE 400 can comprise the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state or the EMM- REGISTERED. PLMN-SEARCH state or the EMM-REGISTERED. LIMITED-SERVICE, as explained above with respect to Fig. 2.
  • the NAS layer 404 Upon receiving the non-EPS service request 41 0 from the user/application layer 402 and upon determining that the UE 400 is in the failure state, the NAS layer 404 is configured to generate a non-LTE camp request 412 and provide the non-LTE camp request 41 2 to the AS layer 406 of the UE 400, in order to complete the voice call through the non-LTE cell.
  • the AS layer 406 Upon receiving the non-LTE camp request 412, the AS layer 406 is configured to camp on to an available non-LTE RAT. In some embodiments, camping on to a suitable non-LTE cell comprises identifying a non-LTE cell in the vicinity of the UE 400.
  • the AS layer 406 is further configured to generate and provide a non-LTE cell camp confirm message 414 to the NAS layer 404.
  • the UE 400 or the NAS layer 404 is configured to provide one or more messages (e.g., the service related messages in Fig. 1 and Fig. 2) to a non-LTE base station associated with the non-LTE RAT, in order to initiate the non-LTE registration.
  • the NAS layer 404 is further configured to process the CM sub-layer request (i.e., the MO voice call) using standard mobility management (MM) procedures.
  • MM mobility management
  • the NAS layer 404 is configured to directly process the CM sub-layer request (i.e., the voice call), via the one or more service related messages, using standard mobility management (MM) procedures, upon receiving the non-LTE camp confirm message 414.
  • MM mobility management
  • Fig. 4b illustrates the events that may occur and/or the operations that may be performed related to a reception of a CS domain paging for initiating a mobile terminating (MT) CS voice call at a user equipment (UE) 450 while the UE operates in EMM-REG ISTERED.ATTEMPTING-TO-UPDATE-MM state, according to an embodiment of the disclosure.
  • the UE 450 is assumed to be camped onto a CSFB enabled LTE cell or a CSFB enabled CS network.
  • the UE 450 described herein can comprise the UE 102 of Fig. 1 or the UE 202 of Fig. 2.
  • an MT CS voice call is initiated at the UE 450 based on a CS domain paging 460 received from the network 458.
  • the AS layer 456 of the UE 450 is configured to receive the CS domain paging 460 from the network 458.
  • the UE 450 is assumed to be in a failure state in this embodiment.
  • the failure state of the UE 450 comprises a state wherein the UE 450 is successfully registered for a PS communication session with a PS-domain associated with network 458, and wherein the UE 458 is not registered for a CS- communication session with a CS-domain associated with the network 458, at least partly due to a temporary issue associated with the CS-domain.
  • the failure state of the UE 450 can comprise the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state.
  • the AS layer 450 of the UE 450 Upon receiving the CS domain paging 460, the AS layer 450 of the UE 450 is configured to generate and provide a CS paging notification 462 to the NAS layer 454 of the UE 450.
  • the NAS layer 454 Upon receiving the CS paging notification 462, the NAS layer 454 is configured to initiate the CSFB procedure in Fig. 1 and Fig. 2) to the network 458.
  • the CSFB procedure is initiated by the NAS layer 454 by generating and providing a service request message (e.g., an extended service request message in some embodiments) to the network 458.
  • the service request message indicates the network 458 that an MT CS call is to be established for the UE 450.
  • the network 458 Upon receiving the extended service request message, the network 458 is configured to initiate the MT CSFB procedure as per the 3GPP standard. Alternately, in other embodiments, the NAS layer 454 can initiate the CSFB procedure
  • Fig. 5 illustrates a flow chart of a method 500 for a UE in a CSFB enabled PS network, according to one embodiment of the disclosure.
  • the UE is explained herein with reference to the apparatus 300 in Fig. 3.
  • the UE can comprise the UE 102 in the CSFB enabled PS network 100 in Fig. 1 and in some embodiments, the UE can comprise the CSFB enabled LTE network 200 in Fig. 2.
  • the method 500 can be utilized for any UE in any CSFB enabled PS network.
  • a determination that a CS communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE is made at the processing circuit 330.
  • the determination that the CS communication session comprising the MO CS call is to be established at the processing circuit 330 may be based at least partly on a service request generated, at the processing circuit 330, by a connection management (CM) sub-layer (e.g., the user/application layer 402 in Fig. 4) of the UE. Further, in some embodiments, the determination that the CS communication session comprising the MT CS call is to be established at the processing circuit 330, may be based on a CS domain paging indicating that an MT CS call is to be established for the UE, received from a core network associated with the CSFB enabled PS network.
  • CM connection management
  • the failure state of the UE can comprise the first failure state, the second failure state or the third failure state, as explained above with respect to Fig. 1 .
  • the failure state of the UE can comprise the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state or the EMM- REGISTERED. PLMN-SEARCH state or the EMM-REGISTERED. LIMITED-SERVICE, as explained above with respect to Fig. 2.
  • one or more registration related messages is provided to a PS base station of the PS network, by the processing circuit, in order to initiate registration with the core network of the CSFB enabled PS network, as part of the establishment of the CSFB procedure for establishing the MT CS voice call, when the UE is in a failure state comprising EMM-REGISTERED. ATTEMPTING- TO-UPDATE-MM state.
  • one or more service related messages is provided to a CS base station of an available CS network, by the processing circuit, in order to attempt to select the available CS network, as part of an establishment of a CS communication session comprising the MO CS voice call, when the UE is in the failure state.
  • an extended service request message is provided to a PS base station of the PS network, by the processing circuit 330, in order to establish a CSFB procedure, when the UE is in the normal state.
  • Fig. 6 illustrates, for one embodiment, example components of a User Equipment (UE) device 600.
  • the UE device 600 may include application circuitry 602, baseband circuitry 604, Radio Frequency (RF) circuitry 606, front-end module (FEM) circuitry 608 and one or more antennas 610, coupled together at least as shown.
  • RF Radio Frequency
  • FEM front-end module
  • the UE 600 can be a part of the UE 204 in Fig. 2 or the UE 304 in Fig. 3.
  • the application circuitry 602 may include one or more application processors.
  • the application circuitry 602 may include circuitry such as, but not limited to, one or more single-core or multi-core processors.
  • the processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.).
  • the processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.
  • the baseband circuitry 604 may include circuitry such as, but not limited to, one or more single-core or multi-core processors.
  • the baseband circuitry 604 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 606 and to generate baseband signals for a transmit signal path of the RF circuitry 606.
  • Baseband processing circuity 604 may interface with the application circuitry 602 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 606.
  • the baseband circuitry 604 may include a second generation (2G) baseband processor 604a, third generation (3G) baseband processor 604b, fourth generation (4G) baseband processor 604c, and/or other baseband processor(s) 604d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.).
  • the baseband circuitry 604 e.g., one or more of baseband processors 604a-d
  • the radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc.
  • modulation/demodulation circuitry of the baseband circuitry 604 may include Fast-Fourier Transform (FFT), precoding, and/or constellation
  • encoding/decoding circuitry of the baseband circuitry 604 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality.
  • LDPC Low Density Parity Check
  • Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.
  • the baseband circuitry 604 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements.
  • EUTRAN evolved universal terrestrial radio access network
  • a central processing unit (CPU) 604e of the baseband circuitry 604 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers.
  • the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 604f.
  • DSP audio digital signal processor
  • the audio DSP(s) 604f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments.
  • Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments.
  • some or all of the constituent components of the baseband circuitry 604 and the application circuitry 602 may be implemented together such as, for example, on a system on a chip (SOC).
  • SOC system on a chip
  • the baseband circuitry 604 may provide for communication compatible with one or more radio technologies.
  • the baseband circuitry 604 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN).
  • EUTRAN evolved universal terrestrial radio access network
  • WMAN wireless metropolitan area networks
  • WLAN wireless local area network
  • WPAN wireless personal area network
  • multi-mode baseband circuitry Embodiments in which the baseband circuitry 604 is configured to support radio communications of more than one wireless protocol.
  • RF circuitry 606 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium.
  • the RF circuitry 606 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network.
  • RF circuitry 606 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 608 and provide baseband signals to the baseband circuitry 604.
  • RF circuitry 606 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 604 and provide RF output signals to the FEM circuitry 608 for transmission.
  • the RF circuitry 606 may include a receive signal path and a transmit signal path.
  • the receive signal path of the RF circuitry 606 may include mixer circuitry 606a, amplifier circuitry 606b and filter circuitry 606c.
  • the transmit signal path of the RF circuitry 606 may include filter circuitry 606c and mixer circuitry 606a.
  • RF circuitry 606 may also include synthesizer circuitry 606d for synthesizing a frequency for use by the mixer circuitry 606a of the receive signal path and the transmit signal path.
  • the mixer circuitry 606a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 608 based on the synthesized frequency provided by synthesizer circuitry 606d.
  • the amplifier circuitry 606b may be configured to amplify the down-converted signals and the filter circuitry 606c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals.
  • LPF low-pass filter
  • BPF band-pass filter
  • Output baseband signals may be provided to the baseband circuitry 604 for further processing.
  • the output baseband signals may be zero- frequency baseband signals, although this is not a requirement.
  • mixer circuitry 606a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.
  • the mixer circuitry 606a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 606d to generate RF output signals for the FEM circuitry 608.
  • the baseband signals may be provided by the baseband circuitry 604 and may be filtered by filter circuitry 606c.
  • the filter circuitry 606c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.
  • LPF low-pass filter
  • the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively.
  • the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection).
  • the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a may be arranged for direct downconversion and/or direct upconversion, respectively.
  • the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may be configured for super-heterodyne operation.
  • the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect.
  • the output baseband signals and the input baseband signals may be digital baseband signals.
  • the RF circuitry 606 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 604 may include a digital baseband interface to communicate with the RF circuitry 606.
  • ADC analog-to-digital converter
  • DAC digital-to-analog converter
  • a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the
  • the synthesizer circuitry 606d may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable.
  • synthesizer circuitry 606d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.
  • the synthesizer circuitry 606d may be configured to synthesize an output frequency for use by the mixer circuitry 606a of the RF circuitry 606 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 606d may be a fractional N/N+1 synthesizer.
  • frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement.
  • VCO voltage controlled oscillator
  • Divider control input may be provided by either the baseband circuitry 604 or the applications processor 602 depending on the desired output frequency.
  • a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 602.
  • Synthesizer circuitry 606d of the RF circuitry 606 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator.
  • the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA).
  • the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio.
  • the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip- flop.
  • the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line.
  • Nd is the number of delay elements in the delay line.
  • synthesizer circuitry 606d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other.
  • the output frequency may be a LO frequency (fLO).
  • the RF circuitry 606 may include an IQ/polar converter.
  • FEM circuitry 608 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 610, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 606 for further processing.
  • FEM circuitry 608 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 606 for transmission by one or more of the one or more antennas 61 0.
  • the FEM circuitry 608 may include a TX/RX switch to switch between transmit mode and receive mode operation.
  • the FEM circuitry may include a receive signal path and a transmit signal path.
  • the receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 606).
  • LNA low-noise amplifier
  • the transmit signal path of the FEM circuitry 608 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 606), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 61 0.
  • PA power amplifier
  • the UE device 600 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.
  • FIG. 7 is a functional diagram of a 3GPP network in accordance with some embodiments. It should be noted that embodiments are not limited to the example 3GPP network shown in FIG. 7, as other networks may be used in some embodiments. Such networks may or may not include some or all of the components shown in FIG. 7, and may include additional components and/or alternative components in some cases.
  • the network comprises a radio access network (RAN) (e.g., as depicted, the E-UTRAN or evolved universal terrestrial radio access network)701 and the core network 720 (e.g., shown as an evolved packet core (EPC)) coupled together through an S1 interface 715.
  • RAN radio access network
  • EPC evolved packet core
  • the core network 720 includes a mobility management entity (MME) 722, a serving gateway (serving GW) 724, and packet data network gateway (PDN GW) 726.
  • the RAN 701 includes Evolved Node-B's (eNBs) 704 (which may operate as base stations) for communicating with User Equipment (UE) 702.
  • the eNBs 704 may include macro eNBs and low power (LP) eNBs.
  • the UE 702 may exchange data signals, control signals and/or other signals with the eNB 704.
  • the signals may be exchanged, in some embodiments, according to one or more packet- switched (PS) techniques, including but not limited to Evolved Packet System (EPS) techniques.
  • PS packet- switched
  • EPS Evolved Packet System
  • the MME 722 is similar in function to the control plane of legacy Serving GPRS Support Nodes (SGSN).
  • the MME 722 manages mobility aspects in access such as gateway selection and tracking area list management.
  • the serving GW 724 terminates the interface toward the RAN 701 , and routes data packets between the RAN 701 and the core network 720. In addition, it may be a local mobility anchor point for inter-eNB handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement.
  • the serving GW 724 and the MME 722 may be implemented in one physical node or separate physical nodes.
  • the PDN GW 726 terminates an SGi interface toward the packet data network (PDN).
  • PDN packet data network
  • the PDN GW 726 routes data packets between the EPC 720 and the external PDN, and 5 may be a key node for policy enforcement and charging data collection. It may also provide an anchor point for mobility with non-LTE accesses.
  • the external PDN can be any kind of IP network, as well as an IP Multimedia Subsystem (IMS) domain.
  • IMS IP Multimedia Subsystem
  • the OFDM signals may comprise a plurality of orthogonal subcarriers.
  • the S1 interface 715 is the interface that separates the RAN 701 and the EPC 720. It is split into two parts: the S1 -U, which carries traffic data between the eNBs 704 and the serving GW 724, and the S1 -MME, which is a signaling interface between the eNBs 704 and the MME 722.
  • the X2 interface is the interface between eNBs 704.
  • the X2 interface comprises two parts, the X2-C and X2-U.
  • the X2-C is the control plane interface between the eNBs 704, while the X2-U is the user plane interface between the eNBs 704.
  • a picocell is a wireless communication system typically covering a small area, such as in- building (offices, shopping malls, train stations, etc.), or more recently in-aircraft.
  • a picocell eNB can generally connect through the X2 link to another eNB such as a macro eNB through its base station controller (BSC) functionality.
  • BSC base station controller
  • LP eNB may be implemented with a picocell eNB since it is coupled to a macro eNB via an X2 interface.
  • Picocell eNBs or other LP eNBs may incorporate some or all functionality of a macro eNB. In some cases, this may be referred to as an access point base station or enterprise femtocell.
  • a downlink resource grid may be used for downlink transmissions from an eNB 704 to a UE 702, while uplink transmission from the UE 702 to the eNB 704 may utilize similar techniques.
  • the grid may be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot.
  • a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation.
  • Each column and each row of the resource grid correspond to one OFDM symbol and one OFDM subcarrier, respectively.
  • the duration of the resource grid in the time domain corresponds to one slot in a radio frame.
  • the smallest time-frequency unit in a resource grid is denoted as a resource element (RE).
  • Each resource grid comprises a number of resource blocks (RBs), which describe the mapping of certain physical channels to resource elements.
  • Each resource block comprises a collection of resource elements in the frequency domain and may represent the smallest quanta of resources that currently can be allocated.
  • the physical downlink shared channel (PDSCH) carries user data and higher- layer signaling to a UE 702 (FIG. 7).
  • the physical downlink control channel (PDCCH) carries information about the transport format and resource allocations related to the PDSCH channel, among other things. It also informs the UE 702 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information related to the uplink shared channel.
  • HARQ hybrid automatic repeat request
  • downlink scheduling (e.g., assigning control and shared channel resource blocks to UEs 702 within a cell) may be performed at the eNB 704 based on channel quality information fed back from the UEs 702 to the eNB 704, and then the downlink resource assignment information may be sent to a UE 702 on the control channel (PDCCH) used for (assigned to) the UE 702.
  • PDCCH control channel
  • the PDCCH uses CCEs (control channel elements) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols are first organized into quadruplets, which are then permuted using a sub-block inter-leaver for rate matching. Each PDCCH is transmitted using one or more of these control channel elements (CCEs), where each CCE corresponds to nine sets of four physical resource elements known as resource element groups (REGs). Four QPSK symbols are mapped to each REG.
  • CCEs control channel elements
  • REGs resource element groups
  • circuitry may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality.
  • ASIC Application Specific Integrated Circuit
  • the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules.
  • circuitry may include logic, at least partially operable in hardware. Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software.
  • circuitry or a similar term can be a processor, a process running on a processor, a controller, an object, an executable program, a storage device, and/or a computer with a processing device.
  • an application running on a server and the server can also be circuitry.
  • circuitry can reside within a process, and circuitry can be localized on one computer and/or distributed between two or more computers.
  • a set of elements or a set of other circuitry can be described herein, in which the term "set” can be interpreted as "one or more.”
  • circuitry or similar term can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors.
  • the one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application.
  • circuitry can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processors therein to execute software and/or firmware that confer(s), at least in part, the functionality of the electronic components.
  • an element when referred to as being “electrically connected” or “electrically coupled” to another element, it can be physically connected or coupled to the other element such that current and/or electromagnetic radiation can flow along a conductive path formed by the elements.
  • Intervening conductive, inductive, or capacitive elements may be present between the element and the other element when the elements are described as being electrically coupled or connected to one another.
  • one element when electrically coupled or connected to one another, one element may be capable of inducing a voltage or current flow or propagation of an electromagnetic wave in the other element without physical contact or intervening components.
  • a voltage, current, or signal when referred to as being "applied" to an element, the voltage, current, or signal may be conducted to the element by way of a physical connection or by way of capacitive, electro-magnetic, or inductive coupling that does not involve a physical connection.
  • Examples can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including instructions that, when performed by a machine cause the machine to perform acts of the method or of an apparatus or system for concurrent communication using multiple communication technologies according to embodiments and examples described herein.
  • Example 1 is an apparatus for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled long term evolution (LTE) network, comprising one or more processors; and a memory including instructions comprising operations, for execution via the one or more processors, to determine that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE; determine whether the UE is in a failure state comprising an evolved packet system mobility management (EMM)- REGISTERED.ATTEMPTING-TO-UPDATE-MM or an EMM-REGISTERED. PLMN- SEARCH or an EMM-REGISTERED.
  • EMM evolved packet system mobility management
  • Example 2 is an apparatus including the subject matter of example 1 , wherein the instructions comprise further operations, for execution via the one or more processors to provide, when the failure state of the UE comprises EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM, one or more registration related messages to a core network associated with the CSFB enabled LTE network to register to the core network, as part of an establishment of a CS communication session comprising the MT CS call.
  • Example 3 is an apparatus including the subject matter of examples 1 -2, including or omitting elements, wherein the instructions comprise further operations, for execution via the one or more processors to determine an availability of the CS network based at least partly on a monitoring for transmissions by CS networks, prior to selecting the CS network for establishing the MO CS call.
  • Example 4 is an apparatus including the subject matter of examples 1 -3, including or omitting elements, wherein the determination that the CS communication session comprising the MO CS call is to be established is based at least partly on a service request generated, at the UE, by a connection management (CM) sublayer of the UE.
  • CM connection management
  • Example 5 is an apparatus including the subject matter of examples 1 -4, including or omitting elements, wherein the determination that the CS communication session comprising the MT CS call is to be established is based on a CS domain paging message received from a core network associated with the LTE network.
  • Example 6 is an apparatus including the subject matter of examples 1 -5, including or omitting elements, wherein the instructions comprise further operations, for execution via the one or more processors to, when the UE is operating in a non-failure state comprising an EMM-REGISTERED. NORMAL-SERVICE, establish the CS communication session comprising the MO CS call or the MT CS call through CSFB procedure.
  • Example 7 is an apparatus including the subject matter of examples 1 -6, including or omitting elements, wherein the instructions comprise further operations, for execution via the one or more processors to, provide an extended service request message comprising an indicator that the CS communication session comprising the MO CS call or the MT CS call is to be established, to an evolved node-B (eNodeB) of the CSFB enabled LTE network, in order to establish the CS communication session through the CSFB procedure.
  • eNodeB evolved node-B
  • Example 8 is an apparatus including the subject matter of examples 1 -7, including or omitting elements, wherein the CSFB enabled LTE network includes a packet-switched (PS) core and a CS core associated therewith.
  • PS packet-switched
  • Example 9 is an apparatus including the subject matter of examples 1 -8, including or omitting elements, wherein the failure state comprising the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM of the UE comprises a state in which the UE is successfully registered for a PS communication session with the PS core, and wherein the UE is not registered for a CS-communication session with the CS core, at least partly due to a temporary issue associated with the CS core of the CSFB enabled LTE network.
  • Example 10 is an apparatus including the subject matter of examples 1 -9, including or omitting elements, wherein the failure state comprising the EMM- REGISTERED.
  • PLMN-SEARCH of the UE comprises a state in which the UE is searching for public land mobile networks (PLMNs).
  • Example 1 1 is an apparatus including the subject matter of examples 1 -1 0, including or omitting elements, wherein the failure state comprising the EMM- REGISTERED.
  • LIMITED-SERVICE of the UE comprises a state wherein a cell selected by the UE is known not to be able to provide normal service and wherein the UE is searching for a suitable cell.
  • Example 12 is an apparatus including the subject matter of examples 1 -1 1 , including or omitting elements, wherein the available CS network comprises a non-LTE network.
  • Example 13 is an apparatus for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled packet-switched (PS) network, comprising one or more processors; and a memory including instructions comprising operations, for execution via the one or more processors, to determine that a circuit-switched (CS)
  • UE user equipment
  • CSFB circuit-switched fall back
  • PS packet-switched
  • a communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE; determine whether the UE is in a failure state comprising a first state wherein the UE is successfully registered for a PS communication session with a PS-domain associated with the CSFB enabled PS network, and wherein the UE is not registered for a CS-communication session with a CS-domain associated with the CSFB enabled PS network, at least partly due to a temporary issue associated with the CS-domain; or a second state wherein the UE is searching for public land mobile networks (PLMNs); or a third state wherein a cell selected by the UE is known not to be able to provide normal service and wherein the UE is searching for a suitable cell; and attempt to select an available CS network, when the UE is in the failure state, by providing, via the one or more processors, one or more service related messages to a CS base station of the available CS network as part of an establishment
  • Example 15 is an apparatus including the subject matter of examples 13-14, including or omitting elements, wherein the CSFB enabled PS network comprises a third-generation partnership project (3GPP) long term evolution (LTE) network that supports CSFB.
  • 3GPP third-generation partnership project
  • LTE long term evolution
  • Example 16 is an apparatus including the subject matter of examples 13-15, including or omitting elements, wherein the first state comprises an EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state, wherein the second state comprises an EMM-REGISTERED. PLMN-SEARCH state and wherein the third state comprises an EMM-REGISTERED. LIMITED-SERVICE state.
  • Example 17 is an apparatus including the subject matter of examples 13-16, including or omitting elements, wherein the instructions comprise further operations, for execution via the one or more processors to, when the UE is operating in a non-failure state comprising an EMM-REGISTERED. NORMAL-SERVICE, establish the CS communication session comprising the MO CS call or the MT CS call through CSFB procedure.
  • Example 18 is an apparatus including the subject matter of examples 13-17, including or omitting elements, wherein the instructions comprise further operations, for execution via the one or more processors to, provide an extended service request message comprising an indicator that the CS communication session comprising the MO CS call or the MT CS call is to be established, to an evolved node-B (eNodeB) of the 3GPP LTE network, in order to establish the CS communication session through the CSFB procedure.
  • eNodeB evolved node-B
  • Example 19 is an apparatus including the subject matter of examples 13-18, including or omitting elements, wherein the PS communication session includes an evolved packet system (EPS) communication session and the CS communication session includes a non-EPS communication session.
  • EPS evolved packet system
  • Example 20 is a method for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled packet-switched (PS) network, comprising determining that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE, at a processing circuit; determining, at the processing circuit, whether the UE is in a failure state comprising a first state wherein the UE is successfully registered for a PS communication session with a PS-domain associated with the CSFB enabled PS network, and wherein the UE is not registered for a CS-communication session with a CS-domain associated with the CSFB enabled PS network, at least partly due to a temporary issue associated with the CS-domain; or a second state wherein the UE is searching for public land mobile networks (PLMNs); or a third state wherein a cell selected by the UE is known not to be able to provide normal service and
  • Example 21 is a method including the subject matter of example 20, further comprising providing, by the processing circuit, one or more registration related messages to a core network associated with the CSFB enabled PS network to register to the core network, as part of an establishment of a CS communication session comprising the MT CS call, when the failure state of the UE comprises the first state.
  • Example 22 is a method including the subject matter of examples 20-21 , including or omitting elements, wherein the CSFB enabled PS network comprises a third-generation partnership project (3GPP) long term evolution (LTE) network that supports CSFB.
  • 3GPP third-generation partnership project
  • LTE long term evolution
  • Example 23 is a method including the subject matter of examples 20-22, including or omitting elements, wherein the first state comprises an EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state, wherein the second state comprises an EMM-REGISTERED. PLMN-SEARCH state and wherein the third state comprises an EMM-REGISTERED. LIMITED-SERVICE state.
  • Example 24 is a method including the subject matter of examples 20-23, including or omitting elements, further comprising establishing, by the processing circuit, the CS communication session comprising the MO CS call or the MT CS call through CSFB procedure, when the UE is operating in a non-failure state comprising an EMM- REGISTERED. NORMAL-SERVICE.
  • Example 25 is an apparatus for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled long term evolution (LTE) network, comprising one or more processors to: determine that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE; determine whether the UE is in a failure state comprising an evolved packet system mobility management (EMM)-REGISTERED.ATTEMPTING-TO-UPDATE-MM or an EMM-REGISTERED. PLMN- SEARCH or an EMM-REGISTERED.
  • EMM evolved packet system mobility management
  • Example 26 is an apparatus including the subject matter of example 25, wherein the one or more processors is further configured to provide, when the failure state of the UE comprises EMM-REGISTERED. ATTEMPTING-TO-UPDATE-MM, one or more registration related messages, via the transceiver circuitry, to a core network associated with the CSFB enabled LTE network to register to the core network, as part of an establishment of a CS communication session comprising the MT CS call.
  • Example 27 is an apparatus including the subject matter of examples 25-26, including or omitting elements, wherein the one or more processors is further configured to determine an availability of the CS network based at least partly on a monitoring for
  • Example 28 is an apparatus including the subject matter of examples 25-27, including or omitting elements, wherein the determination that the CS communication session comprising the MO CS call is to be established is based at least partly on a service request generated, at the UE, by a connection management (CM) sublayer of the UE.
  • CM connection management
  • Example 29 is an apparatus including the subject matter of examples 25-28, including or omitting elements, wherein the determination that the CS communication session comprising the MT CS call is to be established is based on a CS domain paging message received from a core network associated with the LTE network.
  • Example 30 is an apparatus including the subject matter of examples 25-29, including or omitting elements, wherein the one or more processors is further configured to, when the UE is operating in a non-failure state comprising an EMM-REGISTERED. NORMAL- SERVICE, establish the CS communication session comprising the MO CS call or the MT CS call through CSFB procedure.
  • Example 31 is an apparatus including the subject matter of examples 25-30, including or omitting elements, wherein the one or more processors is further configured to, provide an extended service request message comprising an indicator that the CS
  • a communication session comprising the MO CS call or the MT CS call is to be established, to an evolved node-B (eNodeB) of the CSFB enabled LTE network, via the transceiver circuitry, in order to establish the CS communication session through the CSFB procedure.
  • eNodeB evolved node-B
  • Example 32 is an apparatus including the subject matter of examples 25-31 , including or omitting elements, wherein the CSFB enabled LTE network includes a packet- switched (PS) core and a CS core associated therewith.
  • PS packet- switched
  • Example 33 is an apparatus including the subject matter of examples 25-32, including or omitting elements, wherein the failure state comprising the EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM of the UE comprises a state in which the UE is successfully registered for a PS communication session with the PS core, and wherein the UE is not registered for a CS-communication session with the CS core, at least partly due to a temporary issue associated with the CS core of the CSFB enabled LTE network.
  • Example 34 is an apparatus including the subject matter of examples 25-33, including or omitting elements, wherein the failure state comprising the EMM- REGISTERED.
  • PLMN-SEARCH of the UE comprises a state in which the UE is searching for public land mobile networks (PLMNs).
  • Example 35 is an apparatus including the subject matter of examples 25-34, including or omitting elements, wherein the failure state comprising the EMM- REGISTERED.
  • LIMITED-SERVICE of the UE comprises a state wherein a cell selected by the UE is known not to be able to provide normal service and wherein the UE is searching for a suitable cell.
  • Example 36 is an apparatus including the subject matter of examples 25-35, including or omitting elements, wherein the available CS network comprises a non-LTE network.
  • Example 37 is an apparatus for a user equipment (UE) in a circuit-switched fall back (CSFB) enabled packet-switched (PS) network, comprising: one or more processors to determine that a circuit-switched (CS) communication session comprising a mobile originating (MO) CS call or a mobile terminating (MT) CS call is to be established for the UE; determine whether the UE is in a failure state comprising: a first state wherein the UE is successfully registered for a PS communication session with a PS-domain associated with the CSFB enabled PS network, and wherein the UE is not registered for a CS-communication session with a CS-domain associated with the CSFB enabled PS network, at least partly due to a temporary issue associated with the CS-domain; or a second state wherein the UE is searching for public land mobile networks (PLMNs); or a third state wherein a cell selected by the UE is known not to be able to provide normal service and wherein the UE is searching
  • Example 38 is an apparatus including the subject matter of example 37, wherein the one or more processors is further configured to provide, when the failure state of the UE comprises the first state, one or more registration related messages, via the transceiver circuitry, to a core network associated with the CSFB enabled PS network to register to the core network, as part of an establishment of a CS communication session comprising the MT CS call.
  • Example 40 is an apparatus including the subject matter of examples 37-39, including or omitting elements, wherein the first state comprises an EMM- REGISTERED.ATTEMPTING-TO-UPDATE-MM state, wherein the second state comprises an EMM-REGISTERED. PLMN-SEARCH state and wherein the third state comprises an EMM- REGISTERED. LIMITED-SERVICE state.
  • Example 41 is an apparatus including the subject matter of examples 37-40, including or omitting elements, wherein the one or more processors is further configured to, when the UE is operating in a non-failure state comprising an EMM-REGISTERED. NORMAL- SERVICE, establish the CS communication session comprising the MO CS call or the MT CS call through CSFB procedure.
  • Example 42 is an apparatus including the subject matter of examples 37-41 , including or omitting elements, wherein the one or more processors is further configured to, provide an extended service request message comprising an indicator that the CS
  • a communication session comprising the MO CS call or the MT CS call is to be established, to an evolved node-B (eNodeB) of the 3GPP LTE network, via the transceiver circuitry, in order to establish the CS communication session through the CSFB procedure.
  • eNodeB evolved node-B
  • Example 43 is an apparatus including the subject matter of examples 37-42, including or omitting elements, wherein the PS communication session includes an evolved packet system (EPS) communication session and the CS communication session includes a non-EPS communication session.
  • EPS evolved packet system
  • Example 44 is an apparatus comprising, means for executing any of the methods of examples 20-24.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array

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Abstract

L'invention concerne un appareil pour un équipement d'utilisateur (UE) dans un réseau d'évolution à long terme (LTE) autorisant un repli par commutation de circuits (CSFB). L'appareil comprend un ou plusieurs processeurs conçus pour déterminer qu'une session de communication par commutation de circuits (CS) comprenant un appel vocal par CS provenant d'un mobile (MO) doit être établie pour l'UE et déterminer si l'UE est dans un état de défaillance comprenant -ENREGISTRÉ.TENTATIVE-DE-MISE-À-JOUR-MM, un EMM-ENREGISTRÉ.PLMN-RECHERCHE ou un EMM-ENREGISTRÉ.SERVICE-LIMITÉ de gestion de mobilité de système évolué en mode paquet (EMM). Lesdits processeurs sont configurés en outre pour tenter de sélectionner un réseau non LTE disponible prenant en charge des services par CS, par la fourniture d'un ou de plusieurs messages relatifs aux services à une station de base du réseau non LTE disponible en tant que partie d'un établissement d'une session de communication par CS comprenant l'appel par CS, lorsque l'UE est dans l'état de défaillance.
PCT/US2017/015788 2016-03-04 2017-01-31 Gestion d'état améliorée de repli par commutation de circuits (csfb) Ceased WO2017151259A1 (fr)

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Cited By (5)

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WO2019061427A1 (fr) * 2017-09-30 2019-04-04 深圳市云中飞网络科技有限公司 Procédé et appareil d'estimation de détection de point de fréquence anormal et support de stockage informatique
WO2019061435A1 (fr) * 2017-09-30 2019-04-04 深圳市云中飞网络科技有限公司 Procédé et appareil de détection de résultat de rétroaction de csfb et support d'informations
WO2019061438A1 (fr) * 2017-09-30 2019-04-04 深圳市云中飞网络科技有限公司 Procédé et dispositif de détection du résultat de repli d'un repli par commutation de circuits (csfb), et support de stockage
WO2019080064A1 (fr) * 2017-10-26 2019-05-02 深圳市云中飞网络科技有限公司 Procédé de détection d'appel d'équipement utilisateur et produit associé
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US12108363B2 (en) 2018-10-08 2024-10-01 Samsung Electronics Co., Ltd. Method and user equipment for handling service connectivity in wireless communication system

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