The disclosed technology relates generally to voice call setup, and more particularly to methods and a user equipment (UE), for preventing user equipment (UE) measurement reporting to avoid triggering a switch between radio access technologies (RATs) or handoff prior to completing a call setup procedure.
With the advent of wireless/mobile communications came various technologies, such as the global system for mobile communication (GSM), code division multiple access (CDMA), etc. Moreover, while early wireless/mobile communications systems were reliant on circuit switched networks, later-developed wireless/mobile communications systems moved to packet switched networks. When, for example, a packet switched network, such as a long term evolution (LTE) network, was not available, a feature referred to as circuit switched fallback (CSFB) was used. That is, when an LTE (packet switched) network was not available to support a call, for example, a user equipment (UE) could “fall back” to a legacy/more accessible, circuit switched network, such as a third generation wireless (3G) network.
Similarly, voice over LTE (VoLTE) and voice over new radio (VoNR) can refer to packetizing voice over the Internet Protocol (IP) and transporting signaling/data over a 4G/LTE packet switched data path or the fifth generation wireless (5G) user plane (UP). Evolved packet system (EPS) fallback is another mobility procedure or mechanism where a UE may change radio access from 5G to fourth generation wireless (4G) technologies.
The following acronyms are used throughout the drawings and/or descriptions, and are provided below for convenience although other acronyms may be introduced:
In a first aspect, a method is provided. The method comprises determining whether a user equipment (UE) is performing a voice over internet Protocol (VoIP) call setup procedure. Upon a determination that the UE is performing a VoIP call setup, transmission of measurement report information to a network in which the UE Is operating is selectively enabled or disabled until the VoIP call setup procedure is complete. Selective enablement of the transmission of the measurement report information depends upon a further determination that a serving cell currently serving the UE fails to meet a stability threshold. Selective disablement of the transmission of the measurement report information occurs when redirection or handover of the UE pursuant to the transmission of the measurement report information is a possibility.
In a second aspect, a user equipment (UE) is provided. The UE comprises a processor, and a memory unit. The memory unit includes computer code that when executed causes the processor to: enable transmission of measurement report information to a network in which the UE is operating while the UE is performing a voice over Internet Protocol (VoIP) call setup procedure upon a determination that a serving cell currently serving the UE fails to meet a stability threshold; and disable transmission of the measurement report information when redirection or handover of the UE pursuant to the transmission of the measurement report information is a possibility.
In a third aspect, a method is provided. The method comprises, pursuant to receipt of a handover instruction, determining whether a user equipment (UE) is performing a voice over internet Protocol (VoIP) call setup procedure. The method comprises further determining whether the UE transmitted a measurement report prior to receipt of the handover instruction. Upon a determination that no measurement report was transmitted by the UE ignoring the handover instruction and continue with the VoIP call setup procedure.
The present disclosure, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The figures are provided for purposes of illustration only and merely depict typical or example embodiments.
The figures are not exhaustive and do not limit the present disclosure to the precise form disclosed.
Various wireless technology standards enable communications between connected electronic devices, such as the aforementioned user equipment (UEs). 802.11-based wireless communications (Wi-Fi), third-generation wireless (3G), fourth-generation wireless (4G), Long Term Evolution (LTE), and fifth-generation wireless (5G) are examples of existing radio access technologies (RATs) that have corresponding standards that dictate how communications are performed therewith. These RATs, as well as newly developed RATs and standards, support Internet Protocol (IP) Multimedia Subsystem (IMS) and/or Short Message Service (SMS) communications between corresponding devices. Together, these technologies provide connectivity to most current and future cellular or wireless devices.
In some deployments of any RAT, voice calls and communications employ IMS signaling and/or media. Voice and video communications services in the RATs can be implemented on top of IP data connections such that the IMS provides the services for the corresponding RATs. In other words, the IMS provides voice communications as an application service. For example, in 5G New Radio (5G NR), voice calls may be supported entirely over a packet switched (PS) domain with the IMS signaling and/or media, for example, implemented as end-to-end voice over IP (VoIP) connections managed by the IMS.
However, issues can arise when a call is being set up as a VoLTE, VoNR, or EPS fallback call, but the UE is redirected or is triggered to perform a handover to another RAT/cell before the call is connected/established. That is, during operation, a UE typically performs measurements for determining link quality in a network, and sends the resulting measurements in/as measurement reports to the network in which it is operating. If the measurement report reflects values or operating states that necessitate or suggest redirection or handover, the UE will move from one RAT/cell to another. If this occurs before call set up is complete, the call will ultimately fail.
In order to avoid the negative user experience of a dropped call, embodiments of the present disclosure prevent or limit the transmission of measurement reports from a UE to its network (such as a base station/node B/eNodeB/gNB), e.g., until after VoLTE, VoNR, or EPS fallback call setup has been completed. In this way, call setup operations can be completed so the call can progress without disruption or interference. After call setup is complete, “normal” operation can resume and the transmission of measurement reports from a UE can proceed/resume, and redirection or handovers can be performed accordingly. In some embodiments, particular events that could cause the triggering of a redirection or handover are not reported in measurement reports. Thus, even if a measurement report is sent by a UE, the information in the measurement report will not include redirection/handover triggering-information.
In other embodiments, or in conjunction with the aforementioned embodiment(s), when the serving cell call quality/state is worse than a given threshold, and there is a risk of radio link failure, the UE may enable the transmission of measurement reports regardless of whether or not the UE is undergoing call setup. Because there is a probability that any established call might fail anyway, the UE intervening with the transmission of a measurement report can mitigate this risk.
In still other embodiments, a UE may ignore a handover command, in the event the handover is a blind handover. That is, blind handovers can be triggered without receipt of a measurement report from a UE. In order to avoid a handover prior to VoLTE/VoNR/EPS fallback call setup, the UE may ignore the command/request to perform an intra- or inter-RAT (LTE/NR) handover if the UE did not send a measurement report preceding the blind handover command/request. In such a scenario, despite receiving instructions/commands to perform a handover, the UE can continue to perform the in-progress VoLTE/VoNR/EPS fallback call setup operation(s). Accordingly, voice call success rates can increase, and negative user's call setup/progress experience can be avoided.
Before describing the details of the various embodiments contemplated herein, it would be beneficial to describe a communications network in which such embodiments may be implemented or utilized.
A mobile network's RAN may include various infrastructure, e.g., base stations/cell towers, masts, in-home/in-building infrastructure, and the like. The RAN allows users of devices (also referred to as UEs, e.g., smartphones, tablet computers, laptops, vehicle-implemented communication devices (e.g., vehicles having vehicle-to-vehicle (V2V) capabilities), to connect to the core network.
Macro cells can refer to (tall, high-powered) “macro” base stations/cell towers that are able to maintain network signal strength across long/large distances. Macro cells may use multiple input, multiple output (MIMO) antennas that may have various components that allow data to be sent and/or received simultaneously. In the example network 100 of
Small cells can refer to wireless transmitters/receivers implemented as micro base stations designed to provide coverage to areas smaller than those afforded coverage by macro cells, e.g., on the order of about 100 meters (m) to 200 m for outdoor 5G small cells. Indoor 5G small cell deployments may provide coverage on the order about 10 m. Small cells can be mounted or integrated into/onto street lights, utility poles, buildings, etc., and like macro cells, may also leverage massive MIMO antennas. In the example network 100 of
The core network may comprise the mobile exchange and data network used to manage the connections made to/from/via the RAN. As illustrated in
It should also be understood that cells s, t, and n may belong to/be operative in the same or different types of networks. For example, cell s may belong to a 5G network, while cell t belongs to an EPS system. 5G systems include both stand-alone (SA) and non-stand-alone (NSA) architectures, the different being that the SA architecture connects the 5G radio directly to the 5G core network. In contrast the NSA architecture utilizes 4G core control signaling for the 5G RAN (i.e., it is built on/over a 4G network, using an evolved packet core (EPC) network and UEs connect to NR over 4G to access the EPC) versus the 5G-independent operation of the SA architecture. The SA of a 5G network may not be able to support voice call service, and thus, relies on an EPS (the EPC core network), and when a UE registered with the 5G system requests a voice call service, the UE must fall back to the EPS, necessitating a handover between systems.
In the example of
It should be understood that redirection (a type of handover) can also be performed when a UE, e.g., smartphone 126 leaves a cell, e.g., cell s and enters the coverage of cell t. Upon entry into the coverage area of cell t, smartphone 126 also changes from its current “connected” state to an idle mode. The source ENB (of cell s) releases its connection to smartphone 126, will instruct smartphone 126 to redirect itself to the target ENB (of cell t) by indicating the requisite carrier frequency or cell id. With both handover and redirection, movement to another RAT/cell is prompted pursuant to a measurement report function.
Again, mobility/handover decisions are based on measurement reports from a UE. Multiple measurements can be taken and reported, including for example: received signal strength indicator (RSSI); reference signal received power (RSRP); reference signal received quality (RSRQ); signal to interference plus noise ratio (SINR); signal to noise ratio (SNR) to name a few. Table 1, below, presents example events (series A and B) that can be reflected in measurement reports. It should be understood that 3GPP specifications provide a defined set of measurement report mechanisms that a UE can perform, where each type of report is referred to as an event. The type of event a UE must report can be specified by radio resource control (RRC) signaling sent, e.g., from a base station of a cell to a UE.
Events A1-A6 apply to same/intra-RAT events while events 131 and B2 apply to inter-RAT events. Event A1 indicates that the serving cell is better than a given threshold. Event A2 indicates the serving cell becomes worse than the threshold. Event A3 indicates that a neighbor cell becomes better than a special cell by some offset. Even A4 indicates that a neighboring cell becomes better than a defined threshold. Event A5 indicates that a special cell becomes worse than a first threshold, while a neighbor cell becomes better than a second threshold (e.g., a combination of events A2 and A4). Even A6 refers to when a neighbor cell becomes better than a special cell by some defined (positive or negative) offset. Event B1 refers to an inter-RAT neighbor cell becoming better than a defined threshold, while event B2 suggests that a primary serving cell becomes worse that a first defined threshold and an inter-RAT neighbor cell is better than a second defined threshold.
When a UE is involved in any such operations or receives/sends any such messages (or sets of messages/operations indicating an EPS fallback call setup, the UE can, in accordance with various embodiments, prohibit the transmission of a measurement report that would trigger a redirection/handover before the EPS fallback is completed. It should be noted that EPS fallback involves redirection/handover, but it is another or different redirection/handover as a result of a measurement report aside from the EPS fallback redirection/handover that is avoided. That is, the EPS fallback call setup is allowed to continue/complete before another redirection/handover occurs. It should also be noted that even without the message flow/operations described above, the UE can, based, e.g., on RAT and IMS voice call type information, determine that an EPS fallback call setup is in progress. In particular, the UE can make such a determination based on what RAT the UE is currently on, and whether or not a fallback operation has been triggered. For example, if a UE is operating on either LTE or NR, but no fallback has yet been triggered, the call is a VoLTE or VoNR call. On the other hand, if the UE is on NR and there is a fallback triggered, the call is an EPS fallback call type. Thus, if a UE determines that an EPS fallback call setup is in progress based on this information, the UE can still prohibit the transmission of a measurement report/ignore a request for a measurement report.
Again, when a UE is involved in any such operations or receives/sends any such messages (or sets of messages/operations indicating VoLTE or VoNR call setup, the UE can, in accordance with various embodiments, prohibit the transmission of/ignore a request for the transmission of a measurement report that would trigger a redirection/handover before the VoLTE/VoNR call setup is completed.
Referring back to
In some embodiments, upon determining that the UE is performing one of VoNR, VoLTE, or EPS fallback call setup, the UE may receive a handover instruction at operation 410. In certain situations, a network will instruct a UE to handover to another RAT/cell without receiving a measurement report indicative of events suggesting handover. At operation 412, the UE determines whether or not it sent a measurement report prior to receipt of the handover instruction. Upon a determination at operation 414 that the UE did not transmit a measurement report prior to receiving the handover instruction, the UE ignores the handover instruction. That is, the network attempted to initiate a blind handover which if performed before call setup is complete, would also result in a dropped call.
In still other embodiments, upon determining at operation 420 that the UE is performing one of VoNR, VoLTE, or EPS fallback call setup, the UE may compare at least one serving cell measurement to a given threshold regarding quality of service/cell performance. Such a threshold can be based, for example, on RSRP alone, with in combination with RSRQ. Ultimately, the basis on which the threshold can vary, so long as the threshold reflects some value/level indicating that the serving cell is stable enough to remain camped thereon. In some embodiments, the threshold can be derived from test data or other data indicative of cell stability. It should be understood that the threshold can be RAT dependent, e.g., an LTE-related threshold may differ from a 5G-related threshold. At operation 424, upon a determination that the serving cell measurement indicates worse performance than the threshold, the transmission of measurement reports by the UE is enabled. Again, if call setup is allowed with the UE's current serving cell, even if call setup is completed, the call is at risk of being dropped. Thus, in some embodiments, the threshold may be determined such that the threshold delineates some given potential for being dropped against potential for acceptable performance. If the serving cell's performance is deemed to be worse than the given threshold, enabling measurement reporting and undergoing redirection/handover to a better performing target cell first would be preferable to completing call setup when the probability of dropping the call that has been setup is unacceptably high.
The computer system 500 also includes a main memory 506, such as a random access memory (RAM), cache and/or other dynamic storage devices, coupled to bus 502 for storing information and instructions to be executed by processor 504. Main memory 506 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 504. Such instructions, when stored in storage media accessible to processor 504, render computer system 500 into a special-purpose machine that is customized to perform the operations specified in the instructions.
The computer system 500 further includes a read only memory (ROM) 508 or other static storage device coupled to bus 502 for storing static information and instructions for processor 504. A storage device 510, such as a solid state disk (SSD), magnetic disk, optical disk, or USB thumb drive (Flash drive), etc., is provided and coupled to bus 502 for storing information and instructions.
The computer system 500 may be coupled via bus 502 to a display 512, such as a liquid crystal display (LCD) (or touch screen), for displaying information to a computer user. An input device 514, including alphanumeric and other keys, is coupled to bus 502 for communicating information and command selections to processor 504. Another type of user input device is cursor control 516, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 504 and for controlling cursor movement on display 512. In some embodiments, the same direction information and command selections as cursor control may be implemented via receiving touches on a touch screen without a cursor.
The computing system 500 may include a user interface module to implement a GUI that may be stored in a mass storage device as executable software codes that are executed by the computing device(s). This and other modules may include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, bitstreams, data, databases, data structures, tables, arrays, and variables.
In general, the word “component,” “engine,” “system,” “database,” data store,” and the like, as used herein, can refer to logic embodied in hardware or firmware, or to a collection of software instructions, possibly having entry and exit points, written in a programming language, such as, for example, Java, C or C++. A software component may be compiled and linked into an executable program, installed in a dynamic link library, or may be written in an interpreted programming language such as, for example, BASIC, Perl, or Python. It will be appreciated that software components may be callable from other components or from themselves, and/or may be invoked in response to detected events or interrupts. Software components configured for execution on computing devices may be provided on a computer readable medium, such as a compact disc, digital video disc, flash drive, magnetic disc, or any other tangible medium, or as a digital download (and may be originally stored in a compressed or installable format that requires installation, decompression or decryption prior to execution). Such software code may be stored, partially or fully, on a memory device of the executing computing device, for execution by the computing device. Software instructions may be embedded in firmware, such as an EPROM. It will be further appreciated that hardware components may be comprised of connected logic units, such as gates and flip-flops, and/or may be comprised of programmable units, such as programmable gate arrays or processors.
The computer system 500 may implement the techniques described herein using customized hard-wired logic, one or more ASICs or FPGAs, firmware and/or program logic which in combination with the computer system causes or programs computer system 500 to be a special-purpose machine. According to one embodiment, the techniques herein are performed by computer system 500 in response to processor(s) 504 executing one or more sequences of one or more instructions contained in main memory 506. Such instructions may be read into main memory 506 from another storage medium, such as storage device 510. Execution of the sequences of instructions contained in main memory 506 causes processor(s) 504 to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions.
The term “non-transitory media,” and similar terms, as used herein refers to any media that store data and/or instructions that cause a machine to operate in a specific fashion. Such non-transitory media may comprise non-volatile media and/or volatile media. Non-volatile media includes, for example, optical or magnetic disks, such as storage device 510. Volatile media includes dynamic memory, such as main memory 506. Common forms of non-transitory media include, for example, a floppy disk, a flexible disk, hard disk, solid state drive, magnetic tape, or any other magnetic data storage medium, a CD-ROM, any other optical data storage medium, any physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, NVRAM, any other memory chip or cartridge, and networked versions of the same.
Non-transitory media is distinct from but may be used in conjunction with transmission media. Transmission media participates in transferring information between non-transitory media. For example, transmission media includes coaxial cables, copper wire and fiber optics, including the wires that comprise bus 502. Transmission media can also take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications.
The computer system 500 also includes communication interface 518 coupled to bus 502. Communication interface 518 provides a two-way data communication coupling to one or more network links that are connected to one or more local networks. For example, communication interface 518 may be an integrated services digital network (ISDN) card, cable modem, satellite modem, or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 518 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN (or WAN component to communicate with a WAN). Wireless links may also be implemented. In any such implementation, communication interface 518 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.
A network link typically provides data communication through one or more networks to other data devices. For example, a network link may provide a connection through local network to a host computer or to data equipment operated by an Internet Service Provider (ISP). The ISP in turn provides data communication services through the world wide packet data communication network now commonly referred to as the “Internet.” Local network and Internet both use electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on network link and through communication interface 518, which carry the digital data to and from computer system 500, are example forms of transmission media.
The computer system 500 can send messages and receive data, including program code, through the network(s), network link and communication interface 518. In the Internet example, a server might transmit a requested code for an application program through the Internet, the ISP, the local network and the communication interface 518.
The received code may be executed by processor 504 as it is received, and/or stored in storage device 510, or other non-volatile storage for later execution.
Each of the processes, methods, and algorithms described in the preceding sections may be embodied in, and fully or partially automated by, code components executed by one or more computer systems or computer processors comprising computer hardware. The one or more computer systems or computer processors may also operate to support performance of the relevant operations in a “cloud computing” environment or as a “software as a service” (SaaS). The processes and algorithms may be implemented partially or wholly in application-specific circuitry. The various features and processes described above may be used independently of one another, or may be combined in various ways. Different combinations and sub-combinations are intended to fall within the scope of this disclosure, and certain method or process blocks may be omitted in some implementations. The methods and processes described herein are also not limited to any particular sequence, and the blocks or states relating thereto can be performed in other sequences that are appropriate, or may be performed in parallel, or in some other manner. Blocks or states may be added to or removed from the disclosed example embodiments. The performance of certain of the operations or processes may be distributed among computer systems or computers processors, not only residing within a single machine, but deployed across a number of machines.
As used herein, a circuit might be implemented utilizing any form of hardware, software, or a combination thereof. For example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routines or other mechanisms might be implemented to make up a circuit. In implementation, the various circuits described herein might be implemented as discrete circuits or the functions and features described can be shared in part or in total among one or more circuits. Even though various features or elements of functionality may be individually described or claimed as separate circuits, these features and functionality can be shared among one or more common circuits, and such description shall not require or imply that separate circuits are required to implement such features or functionality. Where a circuit is implemented in whole or in part using software, such software can be implemented to operate with a computing or processing system capable of carrying out the functionality described with respect thereto, such as computer system 500.
As used herein, the term “or” may be construed in either an inclusive or exclusive sense. Moreover, the description of resources, operations, or structures in the singular shall not be read to exclude the plural. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps.
Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. Adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known,” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.
This application is a continuation of International Application No. PCT/US2022/014363, filed Jan. 28, 2022, which claims priority to U.S. Provisional Application No. 63/143,325, filed Jan. 29, 2021, the disclosures of which are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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63143325 | Jan 2021 | US |
Number | Date | Country | |
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Parent | PCT/US2022/014363 | Jan 2022 | US |
Child | 18353853 | US |