Method To Fast Recover UE From PS Call Failure In 5G NSA

Embodiments include systems and methods for enabling fast recovery by a user equipment (UE) from packet switched (PS) call failure in a fifth generation (5G) non-standalone (NSA) network. Various embodiments for recovering from PS call failure in a 5G NSA network may include determining whether a total number of Evolved Packet System (EPS) bearer deactivation requests received from a base station of a 5G NSA network during a time period exceeds a maximum counter value, and disabling 5G data calls on the UE in response to determining that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network during the time period exceeds the maximum counter value.

BACKGROUND

Long Term Evolution (LTE), Fifth Generation (5G) new radio (NR)(5G-NR), and other recently developed communication technologies allow user equipment to communicate information at data rates (e.g., in terms of Gigabits per second, etc.) that are orders of magnitude greater than what was available just a few years ago.

Today's communication networks are also more secure, resilient to multipath fading, allow for lower network traffic latencies, provide better communication efficiencies (e.g., in terms of bits per second per unit of bandwidth used, etc.). These and other recent improvements have facilitated the emergence of the Internet of Things (IOT), large scale Machine to Machine (M2M) communication systems, autonomous vehicles, and other technologies that rely on consistent and secure communications.

One implementation option for 5G networks being adopted is a 5G non-standalone (NSA) network in which a radio access network (RAN) providing both LTE and NR support (e.g., a RAN including both LTE base stations, such as LTE Evolved nodeBs (eNodeBs or eNBs), and NR base stations, such as Next Generation NodeB (gNodeBs or gNBs)) is connected to an LTE core network (e.g., an Evolved Packet Core (EPC) network). A user equipment (UE) in such 5G NSA networks that can support both LTE and NR communications can signal to the 5G NSA that the UE supports dual connectivity with new radio (DCNR). In such 5G NSA networks, a packet switched (PS) call failure on a UE indicating support for DCNR can sometimes be unrecoverable and can sometimes result in all subsequent PS service setup attempts failing, thereby preventing data traffic communications. Such PS call failure on a UE indicating support for DCNR can result in a negative user experience as data services, such as Internet access, etc., can be unavailable for a period of time.

SUMMARY

Various aspects include systems and methods for enabling fast recovery by a user equipment (UE) from packet switched (PS) call failure in a fifth generation (5G) non-standalone (NSA) network. Various aspects may be performed by a processor of a UE, such as a modem processor of a UE. Various aspects may include determining whether a total number of Evolved Packet System (EPS) bearer deactivation requests received from a base station of a 5G NSA network during a time period exceeds a maximum counter value, and disabling 5G data calls on the UE in response to determining that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network during the time period exceeds the maximum counter value. Some aspects may further include falling back to fourth generation (4G) for data calls in response to disabling 5G data calls on the UE. In some aspects, the time period may be sixty seconds and the maximum counter value may be five.

Various aspects may further include starting a back-off timer in response to disabling 5G data calls on the UE, determining whether the back-off timer has expired, and enabling 5G data calls on the UE in response to determining that the back-off timer has expired. In some aspects, the back-off timer may expire one hour after starting.

Various aspects may further include sending a first tracking area update request to the base station of the 5G NSA network prior to receiving any EPS bearer deactivation requests from the base station of the 5G NSA network, the first tracking area update request indicating dual connectivity with new radio (DCNR) is supported by the UE, and sending a second tracking area update request to the base station of the 5G NSA network in response to disabling 5G data calls on the UE, the second tracking area update request indicating DCNR is not supported.

Further aspects may include a user equipment having a processor configured to perform one or more operations of any of the methods summarized above. Further aspects may include a non-transitory processor-readable storage medium having stored thereon processor-executable instructions configured to cause a processor of a user equipment to perform operations of any of the methods summarized above. Further aspects include a user equipment having means for performing functions of any of the methods summarized above. Further aspects include a system-on-chip for use in a user equipment that includes a processor configured to perform one or more operations of any of the methods summarized above. Further aspects include a system in a package that includes two systems on chip for use in a user equipment that includes a processor configured to perform one or more operations of any of the methods summarized above.

DETAILED DESCRIPTION

Various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and embodiments are for illustrative purposes, and are not intended to limit the scope of the claims.

Various embodiments include systems and methods for recovering from packet switched (PS) call failure in a fifth generation (5G) non-standalone (NSA) network. Various embodiments may disable 5G data calls on a user equipment (UE) in response to PS call failure. Disabling of 5G data calls may trigger fallback to fourth generation (4G) for data calls. Various embodiments may improve user experience by enabling recovery from PS call failure and thereby allowing data traffic communications between a UE and the NSA network. Various embodiments may improve user experience by making data services, such as Internet access, etc., available to a user after a PS call failure.

The term “user equipment” or “UE” is used herein to refer to personal wireless communication devices including any of cellular telephones, smartphones, portable computing devices, personal or mobile multi-media players, laptop computers, tablet computers, smartbooks, ultrabooks, palmtop computers, wireless electronic mail receivers, and multimedia Internet-enabled cellular telephones. Various embodiments may also be implemented on other forms of wireless devices, which may include wireless router devices, wireless appliances, medical devices and equipment, biometric sensors/devices, wearable devices including smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart rings, smart bracelets, etc.), entertainment devices (e.g., wireless gaming controllers, music and video players, satellite radios, etc.), wireless-network enabled Internet of Things (IoT) devices including smart meters/sensors, industrial manufacturing equipment, large and small machinery and appliances for home or enterprise use, wireless communication elements within autonomous and semiautonomous vehicles, wireless devices affixed to or incorporated into various mobile platforms, global positioning system devices, and similar electronic devices that include a memory, wireless communication components and a programmable processor.

The term “system-on-chip” (SOC) is used herein to refer to a single integrated circuit (IC) chip that contains multiple resources and/or processors integrated on a single substrate. A single SOC may contain circuitry for digital, analog, mixed-signal, and radio-frequency functions. A single SOC may also include any number of general purpose and/or specialized processors (digital signal processors, modem processors, video processors, etc.), memory blocks (e.g., ROM, RAM, Flash, etc.), and resources (e.g., timers, voltage regulators, oscillators, etc.). SOCs may also include software for controlling the integrated resources and processors, as well as for controlling peripheral devices.

As used herein, the terms “network,” “system,” “wireless network,” “cellular network,” and “wireless communication network” may interchangeably refer to a portion or all of a wireless network of a carrier associated with a user equipment and/or subscription on a user equipment. The techniques described herein may be used for various wireless communication networks, such as Code Division Multiple Access (CDMA), time division multiple access (TDMA), FDMA, orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA) and other networks. In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support at least one radio access technology, which may operate on one or more frequency or range of frequencies. For example, a CDMA network may implement Universal Terrestrial Radio Access (UTRA) (including Wideband Code Division Multiple Access (WCDMA) standards), CDMA2000 (including IS-2000, IS-95 and/or IS-856 standards), etc. In another example, a TDMA network may implement GSM Enhanced Data rates for GSM Evolution (EDGE). In another example, an OFDMA network may implement Evolved UTRA (E-UTRA) (including LTE standards), IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. Reference may be made to wireless networks that use LTE standards, and therefore the terms “Evolved Universal Terrestrial Radio Access,” “E-UTRAN” and “eNodeB” may also be used interchangeably herein to refer to a wireless network. However, such references are provided merely as examples, and are not intended to exclude wireless networks that use other communication standards.

LTE is a mobile network standard for 4G wireless communication of high-speed data developed by the 3GPP (3rd Generation Partnership Project) and specified in its Release 8 document series. In contrast to the circuit-switched (CS) model of cellular network standards, LTE has been designed to support only packet switched (PS) services. Data services in LTE may be provided over the Internet, while multimedia services may be supported by the Internet Multimedia Subsystem (IMS) framework. The LTE standard is based on the evolution of the Universal Mobile Telecommunications System (UMTS) radio access through the Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The E-UTRAN together with the Evolved Packet Core (EPC) network (core network accommodating LTE) make up an Evolved Packet System (EPS). While the access network in UMTS emulates a circuit-switched connection for real time services and a packet-switched connection for datacom services, the Evolved Packet System (EPS) is purely Internet Protocol (IP) based, and both real time services and datacom services are carried by the IP protocol.

The 5G system is an advanced technology from 4G LTE, and provides a new radio access technology (RAT) through the evolution of the existing mobile communication network structure. A 5G system may support, for example, extended LTE (eLTE) as well as non-3GPP access (e.g., WLAN).

One implementation option for 5G systems or networks currently being adopted is a 5G NSA network in which a radio access network (RAN) providing both LTE (also referred to as 4G) and NR (also referred to a 5G) support (e.g., a RAN including both LTE base stations, such as LTE Evolved nodeBs (eNodeBs or eNBs), and NR base stations, such as Next Generation NodeB (gNodeBs or gNBs)) is connected to an LTE core network (e.g., an Evolved Packet Core (EPC) network). A user equipment (UE) in such 5G NSA networks that can support both LTE and NR communications can signal to the 5G NSA that the UE supports dual connectivity with new radio (DCNR).

In 5G NSA networks, different data traffic may exist for different services. For example, conventional IP-oriented (i.e., “data-centric”) applications (e.g. web-browsers, games, e-mail applications, etc.), may be provided in an LTE and/or 5G system as data services over the public Internet. Real-time communication services (e.g., voice calls, Short Message Service (SMS) communications, etc.) may be provided in an LTE and/or 5G system as IMS services. The IMS architecture allows operators to offer carrier grade services to be offered on packet-switched networks. Examples of services that have been standardized on top of IMS include Open Mobile Alliance (OMA) presence and group list management, Push-to-Talk over Cellular (PoC), Instant Messaging, and TISPAN/3GPP multimedia telephony for IMS (MMTel). Other IMS services that have been developed for deployment as next-generation LTE services include Voice over LTE (VoLTE) and Video Telephony (VT). Thus, although LTE and 5G data is IP-based, the multiple data types/services may be accessed through different packet data networks (PDN) in the 5G NSA network.

In current 5G NSA networks, a PS call failure on a UE indicating support for DCNR can sometimes be unrecoverable resulting in all subsequent PS service setup attempts failing, thereby preventing data traffic communications (also referred to as data-centric services). Such PS call failures on a UE indicating support for DCNR can result in a negative user experience as data services, such as Internet access, can be unavailable for a period of time.

For example, in some current 5G NSA networks, a 5G capable UE may register with the NSA network and initially indicate the UE has a 5G data capability. Some UE can by default operate in 5G for data calls on the UE. As specific example, the UE may send an attach request (ATTACH_REQ)/tracking area update request (TRACKING_AREA_UPDATE_REQ) indicating DCNR is supported by the UE. For example, a DCNR support flag bit may be set (e.g., DCNR=1) in the attach request/tracking area update request sent to a base station of the 5G NSA network, such as an LTE cell (e.g., an eNB). The base station of the 5G NSA network, such as an LTE cell (e.g., an eNB) may return an attachment acceptance (ATTACH_ACCEPT)/tracking area update acceptance (TRACKING_AREA_UPDATE_ACCEPT) to the UE.

In some current 5G NSA networks, the UE may send a service request for data traffic (e.g., data traffic associated with an Internet browser, social media application, etc.) to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), after attaching to the base station and indicating DCNR support. In this manner, the UE can establish a data call (i.e., a PS call) with the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), to send/receive the data traffic.

In some current 5G NSA networks, following the data service request by the UE indicating DCNR is supported, the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), can deactivate an EPS bearer, thereby causing the data call (i.e., the PS call) to terminate. For example, the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), may send an EPS bearer deactivation request (e.g., a deactivate EPS bearer context request number thirty-six indicating regular deactivation by the network) and the UE may respond accepting the EPS bearer deactivation request (e.g., by sending a deactivate EPS bearer context accept). The EPS bearer may be deactivated on the UE, thereby causing the data call (i.e., the PS call) to terminate.

In some current 5G NSA networks, in response to an EPS bearer deactivation and data call termination, the UE may reattempt to establish a data call (i.e., a PS call) with the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB). For example, the UE may send further service requests to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB). In some current 5G NSA networks, the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB) may send EPS bearer deactivation requests following each further service request by the UE, thereby causing each PS call service request by the UE to fail and the UE to be unable to recover from the initial PS call failure. This repeated failure of the UE to establish a PS call, and resulting repeated failure to support data traffic, causes a degraded user experience as users are unable to access the Internet, often for a long period of time.

Various embodiments enable fast recovery by a UE from PS call failure in a 5G NSA network. Various embodiments may provide an automatic recovery mechanism that may support 5G capable UEs to establish data calls using 4G fallback (i.e., establishing a wireless communication link with a 4G network) in response to EPS bearer deactivation by a base station of the 5G NSA network, such as an LTE cell (e.g., an eNB).

In various embodiments, a processor of a UE (e.g., an application processor (AP), modem processor, etc.) may maintain a counter to record the number of EPS bearer deactivation requests received from a 5G NSA network. The counter reaching a maximum counter value may indicate that the 5G NSA network is operating abnormally and PS call failure may be occurring. In some embodiments, the counter may track the total number of EPS bearer deactivation requests received during a time period. As one example, the time period may be sixty seconds and the maximum counter value may be five EPS bearer deactivation requests. In some embodiments, as EPS bearer deactivation requests are received, indications of the EPS bearer requests may be stored. The indications of the EPS bearer deactivation requests may include timestamps of when the EPS bearer deactivation requests were received. The time period, such as sixty seconds, may extend backward from the most recent received EPS bearer deactivation request. The counter may track the number of EPS bearer deactivation request indications having timestamps falling in the time window corresponding to the time period, such as the total number of EPS bearer deactivation requests received in the sixty seconds prior to the most recent EPS bearer deactivation request. In some embodiments, a counter and timer combination may be used to track the total number of EPS bearer deactivation requests received in a time period. For example, the counter may track a total number of EPS bearer deactivation requests received from a base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), during a time period tracked by the timer, and the counter may be reset at each expiration of the timer.

In various embodiments, in response to determining that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), during the time period exceeds the maximum counter value, a processor of a UE (e.g., AP, modem processor, etc.) may disable 5G data calls on the UE. In various embodiments, disabling the 5G data calls may result in the UE falling back to 4G mode by connecting to a 4G network for data calls.

In various embodiments, in response to disabling 5G data calls on the UE, a processor of a UE (e.g., an AP, modem processor, etc.) may send a tracking area update request to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), indicating DCNR is not supported by the UE. For example, a DCNR support flag bit may be unset (e.g., DCNR=0) in the tracking area update request sent to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), in response to disabling 5G data calls on the UE. The base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), may return a tracking area update acceptance to the UE. The UE may send a service request for data traffic (e.g., data traffic associated with an Internet browser, social media application, etc.) to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), and the EPS bearer may be activated in 4G mode. The activation of the EPS bearer in 4G mode may support the PS call between the UE and the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB) and the sending/receiving of data traffic. As a PS call between the UE and the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB) may be successfully established in 4G mode, rather than previously unsuccessfully attempted in 5G mode, the UE may be considered to have recovered from PS call failure (e.g., the 5G mode PS call failure). The user may be able to access the Internet in 4G mode, improving the user experience in comparison to repeated 5G mode failures.

In some embodiments, in response to disabling 5G data calls on the UE, a processor of a UE (e.g., an AP, modem processor, etc.) may start a back-off timer. The back-off timer may be a timer configured to ensure 5G data calls remain disabled on the UE for a selected period of time. As an example, the back-off timer may be a countdown timer configured to expire one hour after starting. 5G data calls may remain disabled on the UE until the back-off timer expires. In response to determining that the back-off timer has expired, a processor of a UE (e.g., an AP, modem processor, etc.) may enable 5G data calls on the UE. For example, a DCNR support flag bit may be set (e.g., DCNR=1) in a tracking area update request sent to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), in response to enabling 5G data calls on the UE when the back-off timer has expired. Sending the tracking area update request with the DCNR support flag bit set (e.g., DCNR=1) may enable the UE to reestablish 5G data service.

FIG.1is a system block diagram illustrating an example communication system100suitable for implementing any of the various embodiments. The communications system100may be a 5G New Radio (NR) network, or any other suitable network such as an LTE network, 5G NSA network, etc.

The communications system100may include a heterogeneous network architecture that includes a core network140and a variety of mobile devices (illustrated as user equipment (UE)120a-120einFIG.1). The communications system100may also include a number of base stations (illustrated as the BS110a, the BS110b, the BS110c, and the BS110d) and other network entities. A base station is an entity that communicates with user equipments, and also may be referred to as a Node B, an LTE Evolved nodeB (eNodeB or eNB), an access point (AP), a Radio head, a transmit receive point (TRP), a New Radio base station (NR BS), a 5G NodeB (NB), a Next Generation NodeB (gNodeB or gNB), or the like. Each base station may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a base station, a base station Subsystem serving this coverage area, or a combination thereof, depending on the context in which the term is used. The core network140may be any type core network, such as an LTE core network (e.g., an EPC network), 5G core network, etc.

A base station110a-110dmay provide communication coverage for a macro cell, a pico cell, a femto cell, another type of cell, or a combination thereof. A macro cell may cover a relatively large geographic area (for example, several kilometers in radius) and may allow unrestricted access by mobile devices with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by mobile devices with service subscription. A femto cell may cover a relatively small geographic area (for example, a home) and may allow restricted access by mobile devices having association with the femto cell (for example, mobile devices in a closed subscriber group (CSG)). A base station for a macro cell may be referred to as a macro BS. A base station for a pico cell may be referred to as a pico BS. A base station for a femto cell may be referred to as a femto BS or a home BS. In the example illustrated inFIG.1, a base station110amay be a macro BS for a macro cell102a, a base station110bmay be a pico BS for a pico cell102b, and a base station110cmay be a femto BS for a femto cell102c. A base station110a-110dmay support one or multiple (for example, three) cells. The terms “eNB”, “base station”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” may be used interchangeably herein.

In some examples, a cell may not be stationary, and the geographic area of the cell may move according to the location of a mobile base station. In some examples, the base stations110a-110dmay be interconnected to one another as well as to one or more other base stations or network nodes (not illustrated) in the communications system100through various types of backhaul interfaces, such as a direct physical connection, a virtual network, or a combination thereof using any suitable transport network

The base station110a-110dmay communicate with the core network140over a wired or wireless communication link126. The user equipment (UE)120a-120emay communicate with the base station110a-110dover a wireless communication link122.

The wired communication link126may use a variety of wired networks (e.g., Ethernet, TV cable, telephony, fiber optic and other forms of physical network connections) that may use one or more wired communication protocols, such as Ethernet, Point-To-Point protocol, High-Level Data Link Control (HDLC), Advanced Data Communication Control Protocol (ADCCP), and Transmission Control Protocol/Internet Protocol (TCP/IP).

The communications system100also may include relay stations (e.g., relay BS110d). A relay station is an entity that can receive a transmission of data from an upstream station (for example, a base station or a mobile device) and transmit the data to a downstream station (for example, a user equipment (UE) or a base station). A relay station also may be a mobile device that can relay transmissions for other user equipments. In the example illustrated inFIG.1, a relay station110dmay communicate with macro the base station110aand the user equipment120din order to facilitate communication between the base station110aand the user equipment120d. A relay station also may be referred to as a relay base station, a relay base station, a relay, etc.

The communications system100may be a heterogeneous network that includes base stations of different types, for example, macro base stations, pico base stations, femto base stations, relay base stations, etc. These different types of base stations may have different transmit power levels, different coverage areas, and different impacts on interference in communications system100. For example, macro base stations may have a high transmit power level (for example, 5 to 40 Watts) whereas pico base stations, femto base stations, and relay base stations may have lower transmit power levels (for example, 0.1 to 2 Watts).

A network controller130may couple to a set of base stations and may provide coordination and control for these base stations. The network controller130may communicate with the base stations via a backhaul. The base stations also may communicate with one another, for example, directly or indirectly via a wireless or wireline backhaul.

The user equipments (UEs)120a,120b,120cmay be dispersed throughout communications system100, and each user equipment may be stationary or mobile. A user equipment also may be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, user equipment (UE), etc.

A macro base station110amay communicate with the communication network140over a wired or wireless communication link126. The user equipments (UEs)120a,120b,120cmay communicate with a base station110a-110dover a wireless communication link122.

The wireless communication links122,124may include a plurality of carrier signals, frequencies, or frequency bands, each of which may include a plurality of logical channels. The wireless communication links122and124may utilize one or more Radio access technologies (RATs). Examples of RATs that may be used in a wireless communication link include 3GPP LTE, 3G, 4G, 5G (e.g., NR), GSM, CDMA, WCDMA, Worldwide Interoperability for Microwave Access (WiMAX), Time Division Multiple Access (TDMA), and other mobile telephony communication technologies cellular RATs. Further examples of RATs that may be used in one or more of the various wireless communication links122,124within the communication system100include medium range protocols such as Wi-Fi, LTE-U, LTE-Direct, LAA, MuLTEfire, and relatively short range RATs such as ZigBee, Bluetooth, and Bluetooth Low Energy (LE).

While descriptions of some embodiments may use terminology and examples associated with LTE technologies, various embodiments may be applicable to other wireless communications systems, such as a new Radio (NR) or 5G network. NR may utilize OFDM with a cyclic prefix (CP) on the uplink (UL) and downlink (DL) and include support for half-duplex operation using time division duplex (TDD). A single component carrier bandwidth of 100 MHz may be supported. NR Resource blocks may span 12 sub-carriers with a subcarrier bandwidth of 75 kHz over a 0.1 millisecond (ms) duration. Each Radio frame may consist of 50 subframes with a length of 10 ms. Consequently, each subframe may have a length of 0.2 ms. Each subframe may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data. Beamforming may be supported and beam direction may be dynamically configured. Multiple Input Multiple Output (MIMO) transmissions with precoding may also be supported. MIMO configurations in the DL may support up to eight transmit antennas with multi-layer DL transmissions up to eight streams and up to two streams per user equipment. Multi-layer transmissions with up to 2 streams per user equipment may be supported. Aggregation of multiple cells may be supported with up to eight serving cells. Alternatively, NR may support a different air interface, other than an OFDM-based air interface.

Some mobile devices may be considered machine-type communication (MTC) or Evolved or enhanced machine-type communication (eMTC) mobile devices. MTC and eMTC mobile devices include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a base station, another device (for example, remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (for example, a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some mobile devices may be considered Internet-of-Things (IoT) devices or may be implemented as NB-IoT (narrowband internet of things) devices. A user equipment (UE)120a-emay be included inside a housing that houses components of the user equipment, such as processor components, memory components, similar components, or a combination thereof.

In general, any number of communication systems and any number of wireless networks may be deployed in a given geographic area. Each communications system and wireless network may support a particular Radio access technology (RAT) and may operate on one or more frequencies. A RAT also may be referred to as a Radio technology, an air interface, etc. A frequency also may be referred to as a carrier, a frequency channel, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between communications systems of different RATs. In some cases, 4G/LTE and/or 5G/NR RAT networks may be deployed. For example, a 5G NSA network may utilize both 4G/LTE RAT in the 4G/LTE RAN side of the 5G NSA network and 5G/NR RAT in the 5G/NR RAN side of the 5G NSA network. The 4G/LTE RAN and the 5G/NR RAN may both connect to one another and a 4G/LTE core network (e.g., an EPC network) in a 5G NSA network.

In some embodiments, two or more user equipments120a-e(for example, illustrated as the user equipment120aand the user equipment120e) may communicate directly using one or more sidelink channels124(for example, without using a base station110a-110das an intermediary to communicate with one another). For example, user equipment120a-emay communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or similar protocol), a mesh network, or similar networks, or combinations thereof. In this case, the user equipment120a-emay perform scheduling operations, resource selection operations, as well as other operations described elsewhere herein as being performed by the base station110a

FIG.2is a component block diagram illustrating an example computing and wireless modem system200suitable for implementing any of the various embodiments. Various embodiments may be implemented on a number of single processor and multiprocessor computer systems, including a system-on-chip (SOC) or system in a package (SIP).

With reference toFIGS.1and2, the illustrated example user equipment200(which may be a SIP in some embodiments) includes a two SOCs202,204coupled to a clock206, a voltage regulator208, and a wireless transceiver266configured to send and receive wireless communications via an antenna (not shown) to/from network wireless devices, such as a base station110a. In some embodiments, the first SOC202operate as central processing unit (CPU) of the user equipment that carries out the instructions of software application programs by performing the arithmetic, logical, control and input/output (I/O) operations specified by the instructions. In some embodiments, the second SOC204may operate as a specialized processing unit. For example, the second SOC204may operate as a specialized 5G processing unit responsible for managing high volume, high speed (e.g., 5 Gbps, etc.), and/or very high frequency short wave length (e.g., 28 GHz mmWave spectrum, etc.) communications.

The first SOC202may include a digital signal processor (DSP)210, a modem processor212, a graphics processor214, an application processor (AP)216, one or more coprocessors218(e.g., vector co-processor) connected to one or more of the processors, memory220, custom circuitry222, system components and resources224, an interconnection/bus module226, one or more temperature sensors230, a thermal management unit232, and a thermal power envelope (TPE) component234. The second SOC204may include a 5G modem processor252, a power management unit254, an interconnection/bus module264, the plurality of mmWave transceivers256, memory258, and various additional processors260, such as an applications processor, packet processor, etc.

Each processor210,212,214,216,218,252,260may include one or more cores, and each processor/core may perform operations independent of the other processors/cores. For example, the first SOC202may include a processor that executes a first type of operating system (e.g., FreeBSD, LINUX, OS X, etc.) and a processor that executes a second type of operating system (e.g., MICROSOFT WINDOWS 10). In addition, any or all of the processors210,212,214,216,218,252,260may be included as part of a processor cluster architecture (e.g., a synchronous processor cluster architecture, an asynchronous or heterogeneous processor cluster architecture, etc.).

The first and second SOC202,204may include various system components, resources and custom circuitry for managing sensor data, analog-to-digital conversions, wireless data transmissions, and for performing other specialized operations, such as decoding data packets and processing encoded audio and video signals for rendering in a web browser. For example, the system components and resources224of the first SOC202may include power amplifiers, voltage regulators, oscillators, phase-locked loops, peripheral bridges, data controllers, memory controllers, system controllers, access ports, timers, and other similar components used to support the processors and software clients running on a user equipment. The system components and resources224and/or custom circuitry222may also include circuitry to interface with peripheral devices, such as cameras, electronic displays, wireless communication devices, external memory chips, etc.

The first and second SOC202,204may communicate via interconnection/bus module250. The various processors210,212,214,216,218, may be interconnected to one or more memory elements220, system components and resources224, and custom circuitry222, and a thermal management unit232via an interconnection/bus module226. Similarly, the processor252may be interconnected to the power management unit254, the mmWave transceivers256, memory258, and various additional processors260via the interconnection/bus module264. The interconnection/bus module226,250,264may include an array of reconfigurable logic gates and/or implement a bus architecture (e.g., CoreConnect, AMBA, etc.). Communications may be provided by advanced interconnects, such as high-performance networks-on chip (NoCs).

The first and/or second SOCs202,204may further include an input/output module (not illustrated) for communicating with resources external to the SOC, such as a clock206and a voltage regulator208. Resources external to the SOC (e.g., clock206, voltage regulator208) may be shared by two or more of the internal SOC processors/cores.

In addition to the example SIP200discussed above, various embodiments may be implemented in a wide variety of computing systems, which may include a single processor, multiple processors, multicore processors, or any combination thereof.

FIG.3is a component block diagram illustrating a software architecture300including a radio protocol stack for the user and control planes in wireless communications suitable for implementing any of the various embodiments. With reference toFIGS.1-3, the user equipment320may implement the software architecture300to facilitate communication between a user equipment (UE)320(e.g., the user equipment (UE)120a-120e,200) and the base station350(e.g., the base station110a) of a communication system (e.g.,100). In various embodiments, layers in software architecture300may form logical connections with corresponding layers in software of the base station350. The software architecture300may be distributed among one or more processors (e.g., the processors212,214,216,218,252,260). While illustrated with respect to one radio protocol stack, in a multi-SIM (subscriber identity module) user equipment, the software architecture300may include multiple protocol stacks, each of which may be associated with a different SIM (e.g., two protocol stacks associated with two SIMs, respectively, in a dual-SIM wireless communication device). While described below with reference to LTE communication layers, the software architecture300may support any of variety of standards and protocols for wireless communications, and/or may include additional protocol stacks that support any of variety of standards and protocols wireless communications.

The software architecture300may include a Non-Access Stratum (NAS)302and an Access Stratum (AS)304. The NAS302may include functions and protocols to support Packet filtering, security management, mobility control, session management, and traffic and signaling between a SIM(s) of the user equipment and its core network140. The AS304may include functions and protocols that support communication between a SIM(s) and entities of supported access networks (e.g., a base station). In particular, the AS304may include at least three layers (Layer 1, Layer 2, and Layer 3), each of which may contain various sub-layers.

In the user and control planes, Layer 1 (L1) of the AS304may be a physical layer (PHY)306, which may oversee functions that enable transmission and/or reception over the air interface. Examples of such physical layer306functions may include cyclic redundancy check (CRC) attachment, coding blocks, scrambling and descrambling, modulation and demodulation, signal measurements, MIMO, etc. The physical layer may include various logical channels, including the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH).

In the user and control planes, Layer 2 (L2) of the AS304may be responsible for the link between the user equipment320and the base station350over the physical layer306. In the various embodiments, Layer 2 may include a Media Access Control (MAC) sublayer308, a Radio link Control (RLC) sublayer310, and a Packet data convergence protocol (PDCP)312sublayer, each of which form logical connections terminating at the base station350.

In the control plane, Layer 3 (L3) of the AS304may include a Radio Resource Control (RRC) sublayer3. While not shown, the software architecture300may include additional Layer 3 sublayers, as well as various upper layers above Layer 3. In various embodiments, the RRC sublayer313may provide functions including broadcasting system information, paging, and establishing and releasing an RRC signaling connection between the user equipment320and the base station350.

In various embodiments, the PDCP sublayer312may provide uplink functions including multiplexing between different Radio bearers and logical channels, sequence number addition, handover data handling, integrity protection, ciphering, and header compression. In the downlink, the PDCP sublayer312may provide functions that include in-sequence delivery of data packets, duplicate data Packet detection, integrity validation, deciphering, and header decompression.

In the uplink, the RLC sublayer310may provide segmentation and concatenation of upper layer data packets, retransmission of lost data packets, and Automatic Repeat Request (ARQ). In the downlink, while the RLC sublayer310functions may include reordering of data packets to compensate for out-of-order reception, reassembly of upper layer data packets, and ARQ.

In the uplink, MAC sublayer308may provide functions including multiplexing between logical and transport channels, random access procedure, logical channel priority, and hybrid-ARQ (HARQ) operations. In the downlink, the MAC layer functions may include channel mapping within a cell, de-multiplexing, discontinuous reception (DRX), and HARQ operations.

While the software architecture300may provide functions to transmit data through physical media, the software architecture300may further include at least one host layer314to provide data transfer services to various applications in the user equipment320. In some embodiments, application-specific functions provided by the at least one host layer314may provide an interface between the software architecture and the general purpose processor.

In other embodiments, the software architecture300may include one or more higher logical layer (e.g., transport, session, presentation, application, etc.) that provide host layer functions. For example, in some embodiments, the software architecture300may include a network layer (e.g., IP layer) in which a logical connection terminates at a PDN gateway (PGW). In some embodiments, the software architecture300may include an application layer in which a logical connection terminates at another device (e.g., end user device, server, etc.). In some embodiments, the software architecture300may further include in the AS304a hardware interface316between the physical layer306and the communication hardware (e.g., one or more radio frequency (RF) transceivers).

FIG.4is a component block diagram illustrating a communication system400configured for wireless communication in accordance with various embodiments. With reference toFIGS.1-4, the communication system400may include a user equipment (UEs)120and one or more base stations110forming a wireless communication network424, which may provide connections to external resources422. External resources422may include sources of information outside of system400, external entities participating with the system400, and/or other resources.

A user equipment120may be configured by machine-readable instructions406. Machine-readable instructions406may include one or more instruction modules. The instruction modules may include computer program modules. The instruction modules may include one or more of EPS bearer deactivation request monitoring module408, 5G enabling/disabling module410, back-off timer monitoring module412, tracking area update request module414, 4G enabling/disabling module416, and/or other instruction modules.

The EPS bearer deactivation request monitoring module408may be configured to maintain a counter to record the number of EPS bearer deactivation requests received from a 5G NSA network. The EPS bearer deactivation request monitoring module408may be configured to determine whether a total number of EPS bearer deactivation requests received from a base station of a 5G NSA network, such as an LTE cell (e.g., an eNB), during a time period exceeds a maximum counter value. As one example, the time period may be sixty seconds and the maximum counter value may be five. The EPS bearer deactivation request monitoring module408may be configured to determine whether an EPS bearer deactivation request is received from a base station of a 5G NSA network, such as an LTE cell (e.g., an eNB). The EPS bearer deactivation request monitoring module408may be configured to store indications of EPS bearer deactivation requests in a memory (e.g., electronic storage424). The EPS bearer deactivation request monitoring module408may be configured to include timestamps with the indications of the EPS bearer deactivation requests, such as timestamps of when the EPS bearer deactivation requests were received by the user equipment (UE)120a-120e. The EPS bearer deactivation request monitoring module408may be configured to track the number of EPS bearer deactivation request indications having timestamps falling in the time window corresponding to the time period, such as the total number of EPS bearer deactivation requests received in the sixty seconds prior to the most recent EPS bearer deactivation request. The EPS bearer deactivation request monitoring module408may be configured to operate as a counter and timer combination to track the total number of EPS bearer deactivation requests received in a time period. For example, the EPS bearer deactivation request monitoring module408may track a total number of EPS bearer deactivation requests received from a base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), during a time period tracked by the timer, and the counter may be reset at each expiration of the timer. The EPS bearer deactivation request monitoring module408may be configured to indicate to the 5G enabling/disabling module410that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), during the time period exceeds the maximum counter value.

The 5G enabling/disabling module410may be configured to disable and/or enable 5G data calls on the UE. The 5G enabling/disabling module410may be configured to receive an indication that a total number of EPS bearer deactivation requests received from the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), during a time period exceeds the maximum counter value from the EPS bearer deactivation request monitoring module408. The 5G enabling/disabling module410may be configured to disable the 5G data calls on the UE in response to determining that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network during the time period exceeds the maximum counter. The 5G enabling/disabling module410may be configured to signal to the tracking area update request module414that 5G data calls are enabled on the UE and/or that 5G data calls are disabled on the UE. The 5G enabling/disabling module410may be configured to signal to the back-off timer monitoring module412that 5G data calls are disabled on the UE. The 5G enabling/disabling module410may be configured to receive an indication from the back-off timer monitoring module412that a back-off timer has expired. The 5G enabling/disabling module410may be configured to enable 5G data calls on the UE in response to determining that the back-off timer has expired. The 5G enabling/disabling module410may be configured to signal to the 4G enabling/disabling module416that 5G data calls are enabled on the UE and/or that 5G data calls are disabled on the UE.

The back-off timer module412may be configured to receive an indication from the 5G enabling/disabling module410that 5G data calls are disabled on the UE. The back-off timer monitoring module412may be configured to start a back-off timer in response to disabling 5G data calls on the UE. The back-off timer monitoring module412may be configured to determine whether the back-off timer has expired. The back-off timer monitoring module412may be configured to send an indication that the back-off timer has expired to the 5G enabling/disabling module410in response to determining that the back-off timer has expired.

The tracking area update request module414may be configured to send tracking area update requests to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB). The tracking area update request module414may be configured to indicate DCNR is supported by the UE in the tracking area update requests and/or that DCNR is not supported by the UE in the tracking area update requests. For example, the tracking area update request module414may be configured to set (e.g., DCNR=1) or unset (e.g., DCNR=0) flag bits indicating DCNR support (or lack thereof) by the UE in tracking area update requests. The tracking area update request module414may be configured to receive an indication that 5G data calls are enabled on the UE and/or that 5G data calls are disabled on the UE from the 5G enabling/disabling module410. The tracking area update request module414may be configured to receive an indication that 4G data calls are enabled on the UE and/or that 4G data calls are disabled on the UE from the 4G enabling/disabling module416.

The 4G enabling/disabling module416may be configured to disable and/or enable 4G data calls on the UE. The 4G enabling/disabling module416may be configured receive an indication from the 5G enabling/disabling module410that 5G data calls are enabled on the UE and/or that 5G data calls are disabled on the UE. The 4G enabling/disabling module416may be configured to fall back to 4G for data calls in response to disabling 5G data calls on the UE. The 4G enabling/disabling module416may be configured to send an indication that 4G data calls are enabled on the UE and/or that 4G data calls are disabled on the UE to the tracking area update request module414.

The user equipment120, remote platform(s)110, and/or external resources422may be operatively linked via one or more electronic communication links of the wireless communication network. For example, the wireless communication network may establish links via a network such as the Internet and/or other networks.

The user equipment120may include electronic storage424, one or more processors426(e.g., an AP processor216, modem processor212,252, etc.), one or more wireless transceivers266, and/or other components. The user equipment120a-120emay include communication lines, or ports to enable the exchange of information with a network and/or other user equipment. The illustration of the user equipment120is not intended to be limiting. The user equipment120may include a plurality of hardware, software, and/or firmware components operating together to provide the functionality attributed herein to user equipment120.

Electronic storage424may include non-transitory storage media that electronically stores information. The electronic storage media of electronic storage424may include one or both of system storage that is provided integrally (i.e., substantially non-removable) with the user equipment120and/or removable storage that is removably connectable to the user equipment120via, for example, a port (e.g., a universal serial bus (USB) port, a firewire port, etc.) or a drive (e.g., a disk drive, etc.). Electronic storage424may include one or more of optically readable storage media (e.g., optical disks, etc.), magnetically readable storage media (e.g., magnetic tape, magnetic hard drive, floppy drive, etc.), electrical charge-based storage media (e.g., EEPROM, RAM, etc.), solid-state storage media (e.g., flash drive, etc.), and/or other electronically readable storage media. Electronic storage424may include one or more virtual storage resources (e.g., cloud storage, a virtual private network, and/or other virtual storage resources). Electronic storage424may store software algorithms, information determined by processor(s)426, information received from the user equipment120, information received from remote platform(s)110, and/or other information that enables the user equipment120to function as described herein.

The processor(s)426may be configured to provide information processing capabilities in the user equipment120. As such, the processor(s)426may include one or more of a digital processor, an analog processor, a digital circuit designed to process information, an analog circuit designed to process information, a state machine, and/or other mechanisms for electronically processing information. Although the processor(s)426is illustrated as a single entity, this is for illustrative purposes only. In some embodiments, the processor(s)426may include a plurality of processing units and/or processor cores. The processing units may be physically located within the same device, or processor(s)426may represent processing functionality of a plurality of devices operating in coordination. The processor(s)426may be configured to execute modules408,410,412,414, and/or416and/or other modules by software; hardware; firmware; some combination of software, hardware, and/or firmware; and/or other mechanisms for configuring processing capabilities on processor(s)426. As used herein, the term “module” may refer to any component or set of components that perform the functionality attributed to the module. This may include one or more physical processors during execution of processor readable instructions, the processor readable instructions, circuitry, hardware, storage media, or any other components.

It should be appreciated that although modules408,410,412,414, and/or416are illustrated as being implemented within a single processing unit, in embodiments in which the processor(s)426includes multiple processing units and/or processor cores, one or more of modules408,410,412,414, and/or416may be implemented remotely from the other modules. The description of the functionality provided by the different modules408,410,412,414, and/or416described below is for illustrative purposes, and is not intended to be limiting, as any of modules408,410,412,414, and/or416may provide more or less functionality than is described. For example, one or more of the modules408,410,412,414, and/or416may be eliminated, and some or all of its functionality may be provided by other modules408,410,412,414, and/or416. As another example, the processor(s)426may be configured to execute one or more additional modules that may perform some or all of the functionality attributed below to one of the modules408,410,412,414, and/or416.

FIG.5is a process flow diagram illustrating a method500that may be performed by a processor of a user equipment for recovering from PS call failure in a 5G NSA network. With reference toFIGS.1-5, the method500may be implemented by one or more processors (e.g.,210,212,214,216,218,252,260,426) of a UE (e.g.,120,120a-120e,200,320).

In block502, the processor may send a tracking area update request to a base station of a 5G NSA network, the tracking area update request indicating DCNR is supported by the UE. For example, a DCNR support flag bit may be set (e.g., DCNR=1) in a tracking area update request sent to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB). DCNR support may be a default setting for 5G enabled UEs in 5G NSAs. Indicating DCNR is supported by the UE in the tracking area update request may enable the UE to attempt to establish 5G data calls (PS calls) in the 5G NSA network.

In determination block504, the processor may determine whether an EPS bearer deactivation request is received from the base station of the 5G NSA network. The base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), can deactivate an EPS bearer, thereby causing the data call (i.e., the PS call) to terminate. For example, the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), may send an EPS bearer deactivation request (e.g., a deactivate EPS bearer context request number thirty-six indicating regular deactivation by the network) to the UE.

In response to determining that an EPS bearer deactivation request is not received (i.e., determination block504=“No”), the processor may await an EPS bearer deactivation request and continue to determine whether an EPS bearer deactivation request is received from the base station of the 5G NSA network in determination block504.

In response to determining that an EPS bearer deactivation request is received (i.e., determination block504=“Yes”), the processor may store an indication of the EPS bearer deactivation request in block506. In some embodiments, as EPS bearer deactivation requests are received, indications of the EPS bearer requests may be stored. The indications of the EPS bearer deactivation requests may include timestamps of when the EPS bearer deactivation requests were received.

In determination block508, the processor may determine whether a total number of EPS bearer deactivation requests received from a base station of a 5G NSA network during a time period exceeds a maximum counter value. As an example, the time period may be sixty seconds and the maximum counter value may be five EPS bearer deactivation requests. The time period, such as sixty seconds, may extend backward from the most recent received EPS bearer deactivation request. The processor may implement a counter to track the number of EPS bearer deactivation request indications having timestamps falling in the time window corresponding to the time period, such as the total number of EPS bearer deactivation requests received in the sixty seconds prior to the most recent EPS bearer deactivation request. A number of EPS bearer deactivation request indications having timestamps in the time window (i.e., during the time period tracked by the timer) may be compared to the maximum counter value to determine whether a total number of EPS bearer deactivation requests received from a base station of a 5G NSA network during a time period exceeds a maximum counter value.

In some embodiments, a counter and timer combination may be used to track the total number of EPS bearer deactivation requests received in a time period and the operations of block506may be optional. For example, the counter may track a total number of EPS bearer deactivation requests received from a base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), during a time period tracked by the timer, and the counter may be reset at each expiration of the timer. In such embodiments, the processor may compare the counter value to the maximum counter value to determine whether a total number of EPS bearer deactivation requests received from a base station of a 5G NSA network during a time period exceeds a maximum counter value.

In response to determining that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network during the time period does not exceed the maximum counter value (i.e., determination block508=“No”), the processor may await an EPS bearer deactivation request and continue to determine whether an EPS bearer deactivation request is received from the base station of the 5G NSA network in determination block504.

In response to determining that the total number of EPS bearer deactivation requests received from the base station of the 5G NSA network during the time period exceeds the maximum counter value (i.e., determination block508=“Yes”), the processor may disable 5G data calls on the UE in block510. For example, the processor may change a DCNR status from DCNR supported to DCNR not supported to disable 5G data calls.

In block512, the processor may send a tracking area update request to the base station of the 5G NSA network, the tracking area update request indicating DCNR is not supported. In this manner, the processor may cause the tracking area update request to be sent to the base station of the 5G NSA network in response to disabling 5G data calls on the UE. In response to disabling 5G data calls on the UE, a processor of a UE (e.g., an AP, modem processor, etc.) may send a tracking area update request to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), indicating DCNR is not supported by the UE. For example, a DCNR support flag bit may be unset (e.g., DCNR=0) in the tracking area update request sent to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB), in response to disabling 5G data calls on the UE.

In block514, the processor may fall back to 4G mode for data calls on the UE. For example, the processor may scan for and then camp on a 4G wireless network. Thus, the processor may cause the fallback to 4G for data calls on the UE in response to disabling 5G data calls on the UE. The fallback to 4G mode for data calls may result in service requests for data traffic (e.g., data traffic associated with an Internet browser, social media application, etc.) to be issued as 4G mode service requests and the EPS bearer may be activated in 4G mode. The activation of the EPS bearer in 4G mode may support the PS call between the UE and the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB) and the sending/receiving of data traffic. As a PS call between the UE and the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB) may be successfully established in 4G mode, rather than previously unsuccessfully attempted in 5G mode, the UE may be considered to have recovered from PS call failure (e.g., the 5G mode PS call failure). The user may be able to access the Internet in 4G mode, improving the user experience in comparison to repeated 5G mode failures.

In block516, the processor may start a back-off timer in response to disabling 5G data calls on the UE. The back-off timer may be a timer configured to ensure 5G data calls remain disabled on the UE for a selected period of time while permitting the UE to switch back to a 5G network for other service. As one example, the back-off timer may be a countdown timer configured to expire one hour after starting.

In determination block518, the processor may determine whether the back-off timer has expired.

In response to determining that the back-off timer has not expired (i.e., determination block518=“No”), the processor may continue to await the expiration of the back-off timer and determine whether the back-off timer has expired in determination block518. 5G data calls may remain disabled on the UE while the back-off timer has not expired.

In response to determining that the back-off timer has expired (i.e., determination block518=“Yes”), the processor may enable 5G data calls on the UE in block520. For example, the processor may change a DCNR status from DCNR not supported to DCNR supported to enable 5G data calls.

In response to enable 5G data calls on the UE, the processor may send a tracking update request to a base station of a 5G NSA network, the tracking area update request indicating DCNR is supported by the UE, in block502. For example, a DCNR support flag bit may be set (e.g., DCNR=1) in a tracking area update request sent to the base station of the 5G NSA network, such as an LTE cell (e.g., an eNB). The sending of a tracking area update request with the DCNR support flag bit set (e.g., DCNR=1) may enable the UE to reestablish 5G data service.

FIG.6is a call flow diagram illustrating example interactions between one or more processors (such as210,212,214,216,218,252,260,426) of a UE (such as the user equipment120a-120e,200,320,120a-120e) and a base station (e.g., base station110a,350,110) of a 5G NSA network (e.g., network100) accordance with various embodiments. With reference toFIGS.1-6, the interactions illustrated inFIG.6may reflect example implementations of the various embodiment methods for recovering from PS call failure in a 5G NSA network, such as one or more operations of method500.FIG.6illustrates an example implementation in which some operations are performed by an AP processor of the UE and some operations are performed by a modem processor of the UE while the UE is communicating with an LTE cell of the 5G NSA network (labeled LTE Cell_1 inFIG.6).FIG.6illustrates that in response to determining a max counter for EPS bearer deactivation requests being reached, the AP processor may start a back-off timer for 5G and disable 5G data calls.FIG.6further illustrates that upon expiration of the back-off timer, the AP processor may enable 5G data calls.

FIG.7is a component block diagram of a network computing device700suitable for use with various embodiments. Such network computing devices may include at least the components illustrated inFIG.7. With reference toFIGS.1-7, the network computing device700may include a processor701coupled to volatile memory702and a large capacity nonvolatile memory, such as a disk drive703. The network computing device700may also include a peripheral memory access device such as a floppy disc drive, compact disc (CD) or digital video disc (DVD) drive706coupled to the processor701. The network computing device700may also include network access ports704(or interfaces) coupled to the processor701for establishing data connections with a network, such as the Internet and/or a local area network coupled to other system computers and servers. The network computing device700may include one or more antennas707for sending and receiving electromagnetic radiation that may be connected to a wireless communication link. The network computing device700may include additional access ports, such as USB, Firewire, Thunderbolt, and the like for coupling to peripherals, external memory, or other devices.

FIG.8is a component block diagram of a user equipment800suitable for use with various embodiments. With reference toFIGS.1-8, various embodiments may be implemented on a variety of user equipment800(e.g., the user equipment120a-120e,200,320,120a-120e), an example of which is illustrated inFIG.8in the form of a smartphone. The user equipment800may include a first SOC202(e.g., a SOC-CPU) coupled to a second SOC204(e.g., a 5G capable SOC). The first and second SOCs202,204may be coupled to internal memory424,816, a display812, and to a speaker814. Additionally, the user equipment800may include an antenna804for sending and receiving electromagnetic radiation that may be connected to a wireless transceiver266coupled to one or more processors in the first and/or second SOCs202,204. The user equipment800may also include menu selection buttons or rocker switches820for receiving user inputs.

The user equipment800also includes a sound encoding/decoding (CODEC) circuit810, which digitizes sound received from a microphone into data packets suitable for wireless transmission and decodes received sound data packets to generate analog signals that are provided to the speaker to generate sound. Also, one or more of the processors in the first and second SOCs202,204, wireless transceiver266and CODEC810may include a digital signal processor (DSP) circuit (not shown separately).

The processors of the wireless network computing device700and the user equipment800may be any programmable microprocessor, microcomputer or multiple processor chip or chips that can be configured by software instructions (applications) to perform a variety of functions, including the functions of the various embodiments described below. In some mobile devices, multiple processors may be provided, such as one processor within an SOC204dedicated to wireless communication functions and one processor within an SOC202dedicated to running other applications. Software applications may be stored in the memory424,816before they are accessed and loaded into the processor. The processors may include internal memory sufficient to store the application software instructions.

A number of different cellular and mobile communication services and standards are available or contemplated in the future, all of which may implement and benefit from the various embodiments. Such services and standards include, e.g., third generation partnership project (3GPP), LTE systems, third generation wireless mobile communication technology (3G), fourth generation wireless mobile communication technology (4G), fifth generation wireless mobile communication technology (5G), global system for mobile communications (GSM), universal mobile telecommunications system (UMTS), 3GSM, general Packet Radio service (GPRS), code division multiple access (CDMA) systems (e.g., cdmaOne, CDMA1020™), enhanced data rates for GSM evolution (EDGE), advanced mobile phone system (AMPS), digital AMPS (IS-136/TDMA), evolution-data optimized (EV-DO), digital enhanced cordless telecommunications (DECT), Worldwide Interoperability for Microwave Access (WiMAX), wireless local area network (WLAN), Wi-Fi Protected Access I & II (WPA, WPA2), and integrated digital enhanced network (iDEN). Each of these technologies involves, for example, the transmission and reception of voice, data, signaling, and/or content messages. It should be understood that any references to terminology and/or technical details related to an individual telecommunication standard or technology are for illustrative purposes only, and are not intended to limit the scope of the claims to a particular communication system or technology unless specifically recited in the claim language.

Various embodiments illustrated and described are provided merely as examples to illustrate various features of the claims. However, features shown and described with respect to any given embodiment are not necessarily limited to the associated embodiment and may be used or combined with other embodiments that are shown and described. Further, the claims are not intended to be limited by any one example embodiment.