DESC:RESERVATION OF RIGHTS
[001] A portion of the disclosure of this patent document contains material, which is subject to intellectual property rights such as, but are not limited to, copyright, design, trademark, Integrated Circuit (IC) layout design, and/or trade dress protection, belonging to Jio Platforms Limited (JPL) or its affiliates (hereinafter referred as owner). The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all rights whatsoever. All rights to such intellectual property are fully reserved by the owner.

FIELD OF DISCLOSURE
[002] The present disclosure relates to a communication network, and specifically to a system and a method for establishing local emergency calls over a wireless network, for example, a Voice Over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network.

BACKGROUND
[003] The following description of related art is intended to provide background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section be used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of prior art.
[004] Prevalent 4th Generation (4G) Long-Term Evolution (LTE) technology has altered course of lives of common people by digitally connecting them for conducting a plethora of activities, such as personal communications, business transactions, cellular services, and emergency services. With an increasing need for the emergency services, establishing emergency calls using Wireless-Fidelity (Wi-Fi) support is obvious for telecom operators. Since Voice Over Wi-Fi (VoWi-Fi) solutions are commercialized and dialing a local emergency number is an important service, all users may be able to use the emergency services. However, for most operators, calling over the local emergency numbers (e.g., 100/101) is supported over a cellular Radio Access Technology (RAT) only. This may be done to maintain user location privacy during the emergency calling services over the Wi-Fi. Further, VoWi-Fi registered devices are incapable of making local emergency calls as most networks reject the call due to user location privacy. Further, locating the users/callers may be tough especially with the use of inexact tools like cell tower triangulation and Global Positioning System (GPS) when the user is VoWi-Fi registered.
[005] There is, therefore, a need in the art to provide an improved system and a method that facilitates emergency services call over the VoWi-Fi along with an existing cellular RAT.

OBJECTS OF THE PRESENT DISCLOSURE
[006] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
[007] It is an object of the present disclosure to provide a system and a method for establishing an emergency call over a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network.
[008] It is an object of the present disclosure to establish and connect an emergency call over a network using Voice Over Wi-Fi (VoWi-Fi) solutions.
[009] It is an object of the present disclosure to determine, by a network operator, location of a user making the emergency call using the VoWi-Fi solutions.
[0010] It is also an object of the present disclosure to enable emergency call services on the VoWi-Fi network along with a cellular Radio Access Technology (RAT).

SUMMARY OF INVENTION
[0011] This section is provided to introduce certain objects and aspects of the present disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
[0012] In an aspect, the present disclosure relates to a system for establishing an emergency call over a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network. The system includes a processor, and a memory operatively coupled to the processor, where the memory includes processor-executable instructions, which on execution, cause the processor to determine that the VoWi-Fi network is turned on in at least one computing device and the at least one computing device is in a network coverage zone, and receive an invite including a Cellular Network Information (CNI) header from the at least one computing device to initiate the emergency call on the at least one computing device based on the determination. The memory includes processor-executable instructions, which on execution, cause the processor to determine if the at least one computing device is in a cellular out-of-service zone in response to initiation of the emergency call, and perform one of: reject the emergency call over the VoWi-Fi network if the at least one computing device is in the cellular out-of-service zone, and read the CNI header available in the invite and accept the invite to establish the emergency call over the VoWi-Fi network, if the at least one computing device is not in the cellular out-of-service zone.
[0013] In an embodiment, the memory includes processor-executable instructions, which on execution, may cause the processor to determine a cell identifier (ID) included in the invite, and route the emergency call to a public safety answering point (PSAP) over the VoWi-Fi network using the CNI header based on the determination.
[0014] In an embodiment, the processor may determine a location or a cell ID of the at least one computing device associated with a user requesting the emergency call using the cell ID included in the invite.
[0015] In an embodiment, if the at least one computing device is in the cellular out-of-service zone, the memory includes processor-executable instructions, which on execution, may cause the processor to enable the at least one computing device to initiate a forceful handover from the VoWi-Fi network to a Voice over Long Term Evolution (VoLTE) network and establish the emergency call over the VoLTE network based on the initiation of the forceful handover.
[0016] In an embodiment, the invite may further include a P-Access-Network-Information (PANI) header with Wireless Local-Area Network (WLAN) information, and a cell-information age parameter.
[0017] In an embodiment, if the at least one computing device is in the cellular out-of-service zone, the memory includes processor-executable instructions, which on execution, may cause the processor to determine initiation of a new call by the at least one computing device, and toggle a bit pertaining to the cell-information age parameter to 1, based on the determination.
[0018] In an embodiment, the memory includes processor-executable instructions, which on execution, may cause the processor to determine an alternative VoLTE network is available, and toggle the bit pertaining to the cell-information age parameter to 0 to establish the emergency call.
[0019] In an aspect, the present disclosure relates to a method for establishing an emergency call over a VoWi-Fi network. The method includes determining, by a processor associated with a system, that the VoWi-Fi network is turned on in at least one computing device and the at least one computing device is in a network coverage zone. The method includes receiving, by the processor, an invite including a Cellular Network Information (CNI) header from the at least one computing device to initiate the emergency call on the at least one computing device based on the determination. The method includes determining, by the processor, if the at least one computing device is in a cellular out-of-service zone in response to initiating the emergency call. The method includes performing, by the processor, one of: rejecting the emergency call over the VoWi-Fi network if the at least one computing device is in the cellular out-of-service zone, and reading the CNI header available in the invite and accepting the invite to establish the emergency call over the VoWi-Fi network, if the at least one computing device is not in the cellular out-of-service zone.
[0020] In an embodiment, the method may include determining, by the processor, a cell identifier (ID) included in the invite, and routing, by the processor, the emergency call to a public safety answering point (PSAP) over the VoWi-Fi network using the CNI header based on the determination.
[0021] In an embodiment, the method may include determining, by the processor, a location or a cell ID of the at least one computing device associated with a user (102) requesting the emergency call using the cell ID included in the invite.
[0022] In an embodiment, if the at least one computing device is in the cellular out-of-service zone, the method may include enabling, by the processor, the at least one computing device to initiate a forceful handover from the VoWi-Fi network to a VoLTE network, and establishing, by the processor, the emergency call over the VoLTE network based on the initiation of the forceful handover.
[0023] In an embodiment, the invite may include a P-Access-Network-Information (PANI) header with Wireless Local-Area Network (WLAN) information, and a cell-information age parameter.
[0024] In an embodiment, if the at least one computing device is in the cellular out-of-service zone, the method may include determining, by the processor, initiation of a new call by the at least one computing device, and toggling, by the processor, a bit pertaining to the cell-information age parameter to 1, based on the determination.
[0025] In an embodiment, the method may include determining, by the processor, an alternative VoLTE network is available, and toggle the bit pertaining to the cell-information age parameter to 0 to establish the emergency call.
[0026] In an aspect, the present disclosure relates to a user equipment (UE) including one or more processors and a memory operatively coupled to the one or more processors. The memory includes processor-executable instructions, which on execution, cause the one or more processors to register to a VoWi-Fi network, and send an invite including a CNI header to a system. The one or more processors are communicatively coupled with the system, and the system is configured to determine that the VoWi-Fi network is turned on in the UE and the UE is in a network coverage zone. The system is configured to receive the invite from the UE to initiate an emergency call on the UE based on the determination, determine if the UE is in a cellular out-of-service zone in response to initiating the emergency call, and perform one of: reject the emergency call over the VoWi-Fi network if the UE is in the cellular out-of-service zone, and read the CNI header available in the invite and accept the invite to establish the emergency call over the VoWi-Fi network, if the UE is not in the cellular out-of-service zone.

BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings, which are incorporated herein, and constitute a part of this invention, illustrate exemplary embodiments of the disclosed methods and systems in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that invention of such drawings includes the invention of electrical components, electronic components or circuitry commonly used to implement such components.
[0028] The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[0029] FIG. 1 illustrates an exemplary network architecture (100) in which or with which embodiments of the present disclosure may be implemented.
[0030] FIG. 2 illustrates an exemplary block diagram (200) of a proposed system (108), in accordance with an embodiment of the present disclosure.
[0031] FIG. 3 illustrates an exemplary architecture (300) of a system (108) for establishing an emergency call over a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) VoWi-Fi network, in accordance with an embodiment of the present disclosure.
[0032] FIG. 4 illustrates an exemplary flowchart (400) for implementing a method for establishing an emergency call over the VoWi-Fi network, in accordance with an embodiment of the present disclosure.
[0033] FIG. 5 illustrates an exemplary representation (500) depicting a call flow for establishing the emergency call utilizing a Cellular-Network-Information (CNI) header, in accordance with an embodiment of the present disclosure.
[0034] FIGs. 6A and 6B illustrate exemplary representations (600A,600B) depicting call flows for establishing the emergency call if a User Equipment (UE) is VoWi-Fi registered and cellular connection is Out of Service (OOS), in accordance with an embodiment of the present disclosure.
[0035] FIG. 7 illustrates an exemplary computer system (700) in which or with which embodiments of the present disclosure may be utilized in accordance with embodiments of the present disclosure.
[0036] The foregoing shall be more apparent from the following more detailed description of the disclosure.

DETAILED DESCRIPTION
[0037] In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein.
[0038] The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.
[0039] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.
[0040] Also, it is noted that individual embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed but could have additional steps not included in a figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function.
[0041] The word “exemplary” and/or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising” as an open transition word without precluding any additional or other elements.
[0042] Reference throughout this specification to “one embodiment” or “an embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0043] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0044] As per Third Generation Partnership Project (3GPP), when a User Agent (UA) supporting one or more cellular Radio Access Technology (RAT) (e.g., Evolved-Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) is using a non-cellular Internet Protocol (IP) Connectivity Access Network (IP-CAN) to access an IP Multimedia (IM) Core Network (CN) subsystem, details of a radio cell identity of the cellular RAN on which a User Equipment (UE) is camped are transported in a Session Initiation Protocol (SIP) Cellular-Network-Information (CNI) header, which is conveyed in SIP signaling through IP Multimedia Subsystem (IMS) nodes.
[0045] The present disclosure provides a system and a method to establish emergency calls over a Voice Over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network. The system may enable network operators to establish the emergency calls over the VoWi-Fi network along with a cellular RAT using the CNI header. The system may enhance the capability of cellular services to use local emergency services, for example, 100/100 on Wi-Fi. The system may be incorporated in both cellular RATs and over Wi-Fi to establish the emergency calls over the VoWi-Fi network using the CNI header in an efficient manner.
[0046] Various embodiments of the present disclosure will be explained in detail with reference to FIGs. 1-7.
[0047] FIG. 1 illustrates an exemplary network architecture (100) in which or with which a proposed system may be implemented.
[0048] As illustrated in FIG. 1, by way of an example and not by limitation, the exemplary network architecture (100) may include a plurality of computing devices (104-1,104-2…104-N), which may be individually referred as the computing device (104) and collectively referred as the computing devices (104). The plurality of computing devices (104) may include, but not be limited to, scanners such as cameras, webcams, scanning units, and the like.
[0049] In an embodiment, the computing device (104) may include smart devices operating in a smart environment, for example, an Internet of Things (IoT) system. In such an embodiment, the computing device (104) may include, but is not limited to, smartphones, smart watches, smart sensors (e.g., mechanical, thermal, electrical, magnetic, etc.), networked appliances, networked peripheral devices, networked lighting system, communication devices, networked vehicle accessories, networked vehicular devices, smart accessories, tablets, smart television (TV), computers, smart security system, smart home system, other devices for monitoring or interacting with or for the users and/or entities, or any combination thereof.
[0050] A person of ordinary skill in the art will appreciate that the computing device (104) may be interchangeably referred to as user equipment (UE) and may include, but is not limited to, intelligent, multi-sensing, network-connected devices, that may integrate seamlessly with each other and/or with a central server or a cloud-computing system or any other device that is network-connected.
[0051] In an embodiment, the computing device (104) may include, but is not limited to, a handheld wireless communication device (e.g., a mobile phone, a smartphone, a phablet device, and so on), a wearable computer device (e.g., a head-mounted display computer device, a head-mounted camera device, a wristwatch computer device, and so on), a Global Positioning System (GPS) device, a laptop computer, a tablet computer, or another type of portable computer, a media playing device, a portable gaming system, and/or any other type of computer device with wireless communication capabilities, and the like. In an embodiment, the computing device (104) may include, but is not limited to, any electrical, electronic, electro-mechanical, or an equipment, or a combination of one or more of the above devices such as virtual reality (VR) devices, augmented reality (AR) devices, laptop, a general-purpose computer, desktop, personal digital assistant, tablet computer, mainframe computer, or any other computing device, wherein the computing device (104) may include one or more in-built or externally coupled accessories including, but not limited to, a visual aid device such as a camera, an audio aid, a microphone, a keyboard, and input devices for receiving input from the user or the entity such as touchpad, touch enabled screen, electronic pen, and the like. A person of ordinary skill in the art may appreciate that the computing device (104) may not be restricted to the mentioned devices and various other devices may be used.
[0052] In an exemplary embodiment, the computing device/user equipment (104) may communicate with the system (108) through a network (106). The network (106) may include, by way of example but not limitation, at least a portion of one or more networks having one or more nodes that transmit, receive, forward, generate, buffer, store, route, switch, process, or a combination thereof, etc. one or more messages, packets, signals, waves, voltage or current levels, some combination thereof, or so forth. The network (106) may include, by way of example but not limitation, one or more of: a wireless network, a wired network, an internet, an intranet, a public network, a private network, a packet-switched network, a circuit-switched network, an ad hoc network, an infrastructure network, a public-switched telephone network (PSTN), a cable network, a cellular network, a satellite network, a fiber optic network, some combination thereof.
[0053] In an embodiment, the system (108) may determine that a VoWi-Fi network is turned on in the computing device (104) and the computing device (104) is in a network coverage zone.
[0054] In an embodiment, the system (108) may receive an invite including a Cellular Network Information (CNI) header from the computing device (104) to initiate the emergency call on the computing device (104).
[0055] In an embodiment, the system (108) may determine if the computing device (104) is in a cellular out-of-service (OOS) zone in response to the initiation of the emergency call.
[0056] In an embodiment, the system (108) may reject the emergency call over the VoWi-Fi network if the computing device (104) is in the cellular OOS zone.
[0057] In an embodiment, if the computing device (104) is in the cellular OOS zone, the system (108) may initiate a forceful handover from the VoWi-Fi network to a Voice over Long Term Evolution (VoLTE) network, and establish the emergency call over the VoLTE network based on the initiation of the forceful handover.
[0058] In an embodiment, the system (108) may read the CNI header available in the invite and accept the invite to establish the emergency call over the VoWi-Fi network, if the computing device (104) is not in the cellular out-of-service zone.
[0059] In an embodiment, the system (108) may determine a cell identifier (ID) associated with the invite, and route the emergency call to a public safety answering point (PSAP) over the VoWi-Fi network using the CNI header.
[0060] In an embodiment, the system (108) may determine a location or a cell ID of the computing device (104) associated with a user (102) requesting the emergency call using the cell ID associated with the invite.
[0061] Although FIG. 1 shows exemplary components of the network architecture (100), in other embodiments, the network architecture (100) may include fewer components, different components, differently arranged components, or additional functional components than depicted in FIG. 1. Additionally, or alternatively, one or more components of the network architecture (100) may perform functions described as being performed by one or more other components of the network architecture (100).
[0062] FIG. 2 illustrates an exemplary block diagram (200) of the proposed system (108), in accordance with embodiments of the present disclosure.
[0063] With respect to FIG. 2, the system (108) may include one or more processors (202). The one or more processors (202) may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processor(s) (202) may be configured to fetch and execute computer-readable instructions stored in a memory (204) of the system (108). The memory (204) may store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory (204) may include any non-transitory storage device including, for example, volatile memory such as Random-Access Memory (RAM), or non-volatile memory such as Erasable Programmable Read-Only Memory (EPROM), flash memory, and the like.
[0064] In an embodiment, the system (108) may also include an interface(s) (206). The interface(s) (206) may comprise a variety of interfaces, for example, a variety of interfaces, for example, interfaces for data input and output devices, referred to as I/O devices, storage devices, and the like. The interface(s) (206) may facilitate communication of the system (108) with various devices coupled to it. The interface(s) (206) may also provide a communication pathway for one or more components of the system (108). Examples of such components include, but are not limited to, processing engine(s) (208) and a database (210).
[0065] In an embodiment, the processing engine(s) (208) may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine(s) (208). In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine(s) (208) may be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the one or more processors (202) may comprise a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing engine(s) (208). In such examples, the system (108) may comprise the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the system (108) and the processing resource. In other examples, the processing engine(s) (208) may be implemented by an electronic circuitry.
[0066] In an exemplary embodiment, the processing engine(s) (208) may include a determination engine (212), a receiving engine (214), a call establishment engine (216), and other engine(s) (218). The other engine(s) (218) may be selected from any of an input/output engine, data acquisition engine, and the like.
[0067] In an embodiment, the processor (202) may determine that the VoWi-Fi network is turned on in the computing device (104) and the computing device (104) is in a network coverage zone, via the determination engine (212).
[0068] In an embodiment, the processor (202), via the receiving engine (214), may receive an invite including a Cellular Network Information (CNI) header from the computing device (104) to initiate the emergency call on the computing device (104) based on the determination.
[0069] In an embodiment, the processor (202), via the call establishment engine (216), may determine if the computing device (104) is in a cellular OOS zone in response to initiating the emergency call. The processor (202), via the call establishment engine (216), may read the CNI header available in the invite and accept the invite to establish the emergency call over the VoWi-Fi network, if the computing device (104) is not in the cellular OOS zone.
[0070] In an embodiment, the processor (202) may reject the emergency call over the VoWi-Fi network if the computing device (104) is in the cellular out-of-service zone.
[0071] In an embodiment, the database (210) may comprise data that may be either stored or generated as a result of functionalities implemented by any of the components of the processor(s) (202) or the processing engine(s) (208) or the system (108).
[0072] Although FIG. 2 shows the exemplary components of the system (108), in other embodiments, the system (108) may include fewer components, different components, differently arranged components, or additional functional components than depicted in FIG. 2. Additionally, or alternatively, one or more components of the system (108) may perform functions described as being performed by one or more other components of the system (108).
[0073] FIG. 3 illustrates an exemplary architecture (300) of a system (108) for establishing an emergency call over a VoWi-Fi network, in accordance with an embodiment of the present disclosure.
[0074] With respect to FIG. 3, the system (108) may include a UE (302) connected to Wi-Fi and to a Wireless Local Area Network (WLAN). The UE (302) may be, via the Wi-Fi and the WLAN, connected to an Evolved Packet Data Gateway (ePDG) (304) that acts as an interface between an operator network and a public internet. The WLAN and the ePDG (304) may be connected to a Packet Data Network (PDN) Gateway (P-GW) (306). The PDN GW (306) may be a point of interconnect between an Evolved Packet Core (EPC) and external Internet Protocol (IP) networks. The UE (302) may be further connected to a serving Gateway (GW) (308) that may be connected to a Mobility Management Entity (MME) (324), a Home Subscriber Server (HSS) (326), and a Domain Name Server (DNS) (328).
[0075] The PDN GW (306) may be connected to a Proxy-Call Session Control Function (P-CSCF) (310) that may be further connected to an Emergency-Call Session Control Function (E-CSCF) (312). The P-CSCF (310) may be connected to a Serving–Call Session Control Function (S-CSCF) (330), a Telephony Application Server (TAS) (332), and a Multimedia Resource Function (MRF) (334). The E-CSCF (312) may be connected to a Local Retrieval Function (LRF) (314) that may be connected to an Emergency Call server (ECS) (316) to route EC calls. Furthermore, the PDN GW (306) may be connected to a Media Gateway (MGW) (318) that may be connected to a Media Gateway Control Function (MGCF) (320). The E-CSCF (312) may be connected to the MGCF (320) that may be in turn connected to a Public Switched Telephone Network (PSTN) (322) for providing local emergency services.
[0076] FIG. 4 illustrates an exemplary flowchart (400) for implementing a method for establishing an emergency call over a VoWi-Fi network, in accordance with an embodiment of the present disclosure. It must be obvious to a person skilled in the art that a user equipment (104) or a computing device (104) may be registered to a VoWi-Fi network to avail the VoWi-Fi calling services. Also, to use the VoWi-Fi calling services, the VoWi-Fi may have to be turned on at the computing device (104).
[0077] With respect to FIG. 4, the method may include determining that the computing device (104) is in a network coverage zone, and the VoWi-Fi network is turned on in the computing device (104), at 402 and 404.
[0078] At 406, the computing device (104) may itself register over the VoWi-Fi network to avail the VoWi-Fi calling services.
[0079] The method may support local emergency call services over the VoWi-Fi network. In an emergency situation, a user (102) associated with the computing device (104) may initiate the emergency call, at 408. At 410, the computing device (104) may send an invite to the system (108).
[0080] Upon receiving the invite, the system (108) may respond in multiple responses depending on whether the computing device (104) is in a cellular Out of Service (OOS) zone or not. For example, the system (108) may send a response code-604 DOES_NOT_EXIST_ANYWHERE to the computing device (104) and the call fails to connect, if the computing device (104) is in the OOS zone. This may be due to the fact that at Internet Protocol (IP) Multimedia Subsystem (IMS) core, local emergency call 100/101/108 routing may be implemented as location-based. The system (108) may reject the call due to user location privacy in the VoWi-Fi calling services.
[0081] Although in the VoWi-Fi network, the user device or the computing device (104) may send the invite including a hotspot Identifier (ID) (i.e., WLAN information) in a P-Access-Network-Information (PANI) header, and a cell ID in a Cellular Network Information (CNI) to the system (108), at 410. The CNI header may be considered by the system (108) for emergency calls over the VoWi-Fi network.
[0082] As per 3GPP specifications, the system (108) may use the CNI header to determine the cell ID of the computing device (104) which has sent the invite in step 410, over the Wi-Fi RAT. The system (108) may not depend on the PANI header to determine the cell ID of the invite over the Wi-Fi, instead the system (108) may accurately route the emergency calls over the VoWi-Fi in case of Wi-Fi and Long-term Evolution (LTE) conditions being available.
[0083] Further, a location or a cell ID of the user (102) requesting for the emergency services may be determined during a VoWi-Fi emergency call, because the invite sent in the emergency situation by the computing device (104) at step 410 contains the cell ID in the CNI header.
[0084] However, with the VoWi-Fi registered and no-service scenario, if the emergency call, e.g., 100/101 call is initiated, the system (108) may use the last registered cell ID on which a Device Under Test (DUT), for example, the computing device (104) is camped before entering a no-service zone in the CNI header.
[0085] With cell-information-age parameter indicated in the invite, the system (108) may determine if the DUT is in an LTE coverage zone or not. The cell-information-age parameter may change to non-zero value only if the device, e.g., the DUT, is moved to OOS zone (e.g., as shown in step 414). In other cases, the value of the cell-information-age parameter may remain unchanged (i.e., 0).
[0086] For the above-mentioned VoWi-Fi registered and no-service scenario, the system (108) may consider the parameter of cell-information-age. The system (108) may determine if the computing device (104) is in the cellular service zone or not. In an embodiment, if the computing device (104) moves to the OOS zone, the cell-information-age bit may toggle to “1”, i.e., non-zero, when the computing device (104) initiates a new call. In such situation, the system (108) may reject the calls because of non-availability of cellular service.
[0087] Further, in another embodiment, when the next LTE RAT is available after the OOS zone, the computing device (104) may update the new cell ID information in the CNI header field and the cell-information-age bit may toggle to “0”, indicating the availability of the cellular service (e.g., LTE coverage zone). Till then during VoWi-Fi and LTE no-service scenarios, the system (108) may reject the emergency call request, at 416.
[0088] In yet another embodiment, a forceful handover (HO) may be triggered from the computing device (104) during the emergency call over the VoWi-Fi network, in the availability of the cellular service, at 420.
[0089] Therefore, if the local emergency call (e.g., 100/102/108, etc.,) is dialled over the Wi-Fi RAT, the computing device (104) may perform immediate handover from the VoWi-Fi network to the available LTE network, and process the local emergency call as VoLTE emergency call, at 422.
[0090] However, handover may not work in case of VoWi-Fi registered and no-service condition as the computing device (104) may fail to handover to the LTE network.
[0091] Furthermore, if the computing device (104) is not in the cellular OOS zone, the computing device (104) may share the PANI header with WLAN information and the last registered cellular cell ID information within the CNI header along with the invite to the system (108), at 410a.
[0092] Upon receiving the CNI header in step (410/410a), the system (108) may read the CNI header available in the shared invite. Further, the system (108) may accept the invite and establish the emergency call over the VoWi-Fi network, at 418.
[0093] In an embodiment, if the system (108) determines that the VoWi-Fi network is not turned on the computing device (104) and the computing device (104) is not in the VoWi-Fi coverage zone, then the method may be halted.
[0094] FIG. 5 illustrates an exemplary representation (500) depicting a call flow for establishing the emergency call utilizing a CNI header, in accordance with an embodiment of the present disclosure.
[0095] With respect to FIG. 5, the UE (302) may send a SIP register (WLAN) request to a P-CSCF/E-CSCF (310/312). On receiving the request, the P-CSCF/E-CSCF (310/312) may send a response message (e.g., 200 OK message) to the UE (302). The UE (302) may send an invite (i.e., initiate a local emergency call 100, etc.) which includes the cell ID information in the CNI header. The P-CSCF/E-CSCF (310/312) may send a 100 trying and a 180 ringing response to the UE (302). Further, the UE (302) may send a PRACK response to the P-CSCF/E-CSCF (310/312) and receive a 200 OK response message. Further, a 200 OK (INVITE) may be received by the UE (302), and thereafter an ACK may be shared by the UE (302) to the P-CSCF/E-CSCF (310/312).
[0096] With respect to FIG. 5, instead of rejecting the call due to “604 (User Location Mapping Does Not Exist)”, the P-CSCF/E-CSCF (310/312) may utilize the CNI header for identifying the location and route the call to a PSAP.
[0097] FIGs. 6A and 6B illustrate exemplary representations (600A,600B) depicting the call flows for establishing the emergency call if the UE (104) is VoWi-Fi registered and the cellular connection is OOS, in accordance with an embodiment of the present disclosure.
[0098] With respect to FIG. 6A, the UE (302) may send a SIP register (WLAN) request to the P-CSCF/E-CSCF (310/312) and receive a 200 OK response message. The UE (302) may then send an invite (i.e., initiate a local emergency call 100 etc.,) to the P-CSCF/E-CSCF (310/312). The P-CSCF/E-CSCF (310/312) may respond with 100 trying message and then send a DOES_NOT_EXIST_ANYWHERE (604) response to the UE (302). On receiving the response, the UE (302) may send an ACK to the P-CSCF/E-CSCF (310/312).
[0099] According to FIG. 6A, the system (108) may reject the call due to “604 (User Location Mapping Does Not Exist)”.
[00100] With respect to FIG. 6B, the UE (302) may send a SIP register (WLAN) message to the P-CSCF/E-CSCF (310/312) and receives a 200 OK response message. The UE (302) may send an invite (i.e., initiate a local emergency call 100, etc.) which includes the cell ID information in the CNI header and send a SIP register (cellular) message to the P-CSCF/E-CSCF (310/312). Upon receiving the invite, the P-CSCF/E-CSCF (310/312) may send a 200 OK response to the UE (302). The UE (302) may again send the invite (i.e., initiate a local emergency call 100 etc.), which includes the updated cell ID information in the CNI header to the P-CSCF/E-CSCF (310/312), and receive a 100 trying response, followed by 180 ringing response from the P-CSCF/E-CSCF (310/312). Further, the UE (302) may send a PRACK response to the P-CSCF/E-CSCF (310/312) and receive a 200 OK and a 200 OK (INVITE) message from the P-CSCF/E-CSCF (310/312). Finally, the UE (302) may share an acknowledgement response to the P-CSCF/E-CSCF (310/312).
[00101] According to FIG. 6B, the UE (302) may hold the invite in buffer and try forceful HO from the VoWi-Fi network to a VoLTE network if the computing device (104) is in the cellular OOS zone.
[00102] FIG. 7 illustrates an exemplary computer system (700) in which or with which embodiments of the present disclosure may be utilized in accordance with embodiments of the present disclosure.
[00103] As shown in FIG. 7, the computer system (700) may include an external storage device (710), a bus (720), a main memory (730), a read-only memory (740), a mass storage device (750), a communication port (760), and a processor (770). A person skilled in the art will appreciate that the computer system (700) may include more than one processor and communication ports. The processor (770) may include various modules associated with embodiments of the present disclosure.
[00104] In an embodiment, the communication port (760) may be any of an RS-232 port for use with a modem dialup connection, a 10/100 Ethernet port, a Gigabit or 10 Gigabit port using copper or fiber, a serial port, a parallel port, or other existing or future ports. The communication port (760) may be chosen depending on a network, such as a Local Area Network (LAN), a Wide Area Network (WAN), or any network to which the computer system (700) connects.
[00105] In an embodiment, the memory (730) may be a Random Access Memory (RAM), or any other dynamic storage device commonly known in the art. The read-only memory (740) may be any static storage device(s), for e.g., but not limited to, a Programmable Read Only Memory (PROM) chips for storing static information e.g., start-up or BIOS instructions for processor (770).
[00106] In an embodiment, the mass storage (750) may be any current or future mass storage solution, which may be used to store information and/or instructions. Exemplary mass storage solutions may include, but are not limited to, Parallel Advanced Technology Attachment (PATA), or Serial Advanced Technology Attachment (SATA) hard disk drives, or solid-state drives (internal or external, e.g., having Universal Serial Bus (USB) and/or Firewire interfaces).
[00107] In an embodiment, the bus (720) may be communicatively coupled with the processor(s) (770) with the other memory, storage, and communication blocks. The bus (720) may be, e.g., a Peripheral Component Interconnect (PCI)/PCI Extended (PCI-X) bus, Small Computer System Interface (SCSI), USB, or the like, for connecting expansion cards, drives, and other subsystems as well as other buses, such a front side bus (FSB), which connects the processor (770) to the software system.
[00108] Optionally, operator and administrative interfaces, e.g., a display, a keyboard, a joystick, and a cursor control device, may also be coupled to the bus (720) to support direct operator interaction with the computer system (700). Other operator and administrative interfaces may be provided through the network connections connected through the communication port (760).
[00109] In an embodiment, the external storage device (710) may be any kind of external hard-drives, floppy drives, zip drives, Compact Disc-Read Only Memory (CD-ROM), Compact Disc-Re-Writable (CD-RW), Digital Video Disk-Read Only Memory (DVD-ROM). The components described above are meant only to exemplify various possibilities. In no way should the aforementioned exemplary computer system limit the scope of the present disclosure.
[00110] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[00111] The present disclosure provides a system and a method for establishing an emergency call over a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network.
[00112] The present disclosure establishes and connects an emergency call over a network using Voice Over Wi-Fi (VoWi-Fi) solutions.
[00113] The present disclosure determines, by a network operator, location of a user making the emergency call using the VoWi-Fi solutions.
[00114] The present disclosure enables emergency call services on the VoWi-Fi network along with a cellular Radio Access Technology (RAT).
,CLAIMS:1. A system (108) for establishing an emergency call over a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network, the system (108) comprising:
a processor (202); and
a memory (204) operatively coupled to the processor (202), wherein the memory (204) comprises processor-executable instructions, which on execution, cause the processor (202) to:
determine that the VoWi-Fi network is turned on in at least one computing device (104) and the at least one computing device (104) is in a network coverage zone;
receive an invite comprising a Cellular Network Information (CNI) header from the at least one computing device (104) to initiate the emergency call on the at least one computing device (104) based on the determination;
determine if the at least one computing device (104) is in a cellular out-of-service zone in response to the initiation of the emergency call; and
perform one of:
reject the emergency call over the VoWi-Fi network if the at least one computing device (104) is in the cellular out-of-service zone; and
read the CNI header available in the invite and accept the invite to establish the emergency call over the VoWi-Fi network, if the at least one computing device (104) is not in the cellular out-of-service zone.

2. The system (108) as claimed in claim 1, wherein the memory (204) comprises processor-executable instructions, which on execution, cause the processor (202) to determine a cell identifier (ID) comprised in the invite, and route the emergency call to a public safety answering point (PSAP) over the VoWi-Fi network using the CNI header based on the determination.

3. The system (108) as claimed in claim 2, wherein the processor (202) is to determine a location or a cell ID of the at least one computing device (104) associated with a user (102) requesting the emergency call using the cell ID comprised in the invite.

4. The system (108) as claimed in claim 1, wherein if the at least one computing device (104) is in the cellular out-of-service zone, the memory (204) comprises processor-executable instructions, which on execution, cause the processor (202) to enable the at least one computing device (104) to:
initiate a forceful handover from the VoWi-Fi network to a Voice over Long Term Evolution (VoLTE) network; and
establish the emergency call over the VoLTE network based on the initiation of the forceful handover.

5. The system (108) as claimed in claim 1, wherein the invite comprises at least one of: a P-Access-Network-Information (PANI) header with Wireless Local-Area Network (WLAN) information, and a cell-information age parameter.

6. The system (108) as claimed in claim 5, wherein if the at least one computing device (104) is in the cellular out-of-service zone, the memory (204) comprises processor-executable instructions, which on execution, cause the processor (202) to determine initiation of a new call by the at least one computing device (104), and toggle a bit pertaining to the cell-information age parameter to 1, based on the determination.

7. The system (108) as claimed in claim 6, wherein the memory (204) comprises processor-executable instructions, which on execution, cause the processor (202) to determine that an alternative Voice over Long Term Evolution (VoLTE) network is available, and toggle the bit pertaining to the cell-information age parameter to 0 to establish the emergency call.

8. A method for establishing an emergency call over a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network, the method comprising:
determining, by a processor (202) associated with a system (108), that the VoWi-Fi network is turned on in at least one computing device (104), and the at least one computing device (104) is in a network coverage zone;
receiving, by the processor (202), an invite comprising a Cellular Network Information (CNI) header from the at least one computing device (104) to initiate the emergency call on the at least one computing device (104) based on the determination;
determining, by the processor (202), if the at least one computing device (104) is in a cellular out-of-service zone in response to the initiation of the emergency call; and
performing, by the processor (202), one of:
rejecting the emergency call over the VoWi-Fi network if the at least one computing device (104) is in the cellular out-of-service zone; and
reading the CNI header available in the invite and accepting the invite to establish the emergency call over the VoWi-Fi network, if the at least one computing device (104) is not in the cellular out-of-service zone.

9. The method as claimed in claim 8, comprising:
determining, by the processor (202), a cell identifier (ID) comprised in the invite; and
routing, by the processor (202), the emergency call to a public safety answering point (PSAP) over the VoWi-Fi network using the CNI header based on the determination.

10. The method as claimed in claim 9, comprising determining, by the processor (202), a location or a cell ID of the at least one computing device (104) associated with a user (102) requesting the emergency call using the cell ID comprised in the invite.

11. The method as claimed in claim 8, wherein if the at least one computing device is in the cellular out-of-service zone, the method comprises:
enabling, by the processor (202), the at least one computing device (104) to initiate a forceful handover from the VoWi-fi network to a Voice over Long Term Evolution (VoLTE) network; and
establishing, by the processor (202), the emergency call over the VoLTE network based on the initiation of the forceful handover.

12. The method as claimed in claim 8, wherein the invite comprises at least one of: a P-Access-Network-Information (PANI) header with Wireless Local-Area Network (WLAN) information, and a cell-information age parameter.

13. The method as claimed in claim 12, wherein if the at least one computing device (104) is in the cellular out-of-service zone, the method comprises determining, by the processor (202), initiation of a new call by the at least one computing device (104), and toggling, by the processor (202), a bit pertaining to the cell-information age parameter to 1, based on the determination.

14. The method as claimed in claim 13, wherein the method comprises determining, by the processor (202), an alternative VoLTE network is available, and toggling, by the processor (202), the bit pertaining to the cell-information age parameter to 0 to establish the emergency call.

15. A user equipment (UE) (104), comprising:
one or more processors; and
a memory operatively coupled to the one or more processors, wherein the memory comprises processor-executable instructions, which on execution, cause the one or more processors to:
register to a Voice over Wireless-Fidelity (Wi-Fi) (VoWi-Fi) network; and
send an invite comprising a Cellular Network Information (CNI) header to a system (108),
wherein the one or more processors are communicatively coupled with the system (108), and wherein the system (108) is configured to:
determine that the VoWi-Fi network is turned on in the UE (104) and the UE (104) is in a network coverage zone;
receive the invite from the UE (104) to initiate an emergency call on the UE (104) based on the determination;
determine if the UE (104) is in a cellular out-of-service zone in response to initiating the emergency call; and
perform one of:
reject the emergency call over the VoWi-Fi network if the UE (104) is in the cellular out-of-service zone; and
read the CNI header available in the invite and accept the invite to establish the emergency call over the VoWi-Fi network, if the UE (104) is not in the cellular out-of-service zone.