Patent Publication Number: US-2022232670-A1

Title: Method and apparatus for handling emergency services in a wireless network

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 16/903,092, filed Jun. 16, 2020, which is based on and claims priority under 35 U.S.C. § 119(a) to Indian Provisional Application No. 201941024005 filed on Jun. 17, 2019, and Indian complete Application No. 201941024005 filed on Jun. 8, 2020, the disclosures of which are herein incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure relates to the field of wireless networks and more particularly to handling emergency services in a wireless network. 
     2. Description of Related Art 
     To meet the demand for wireless data traffic having increased since deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. The 5G or pre-5G communication system is also called a ‘beyond 4G network’ or a ‘post long term evolution (LTE) system’. The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beamforming, and large scale antenna techniques are discussed with respect to 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like. 
     In the 5G system, hybrid frequency shift keying (FSK) and Feher&#39;s quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed. 
     The Internet, which is a human-centered connectivity network where humans generate and consume information, is now evolving to the Internet of things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of everything (IoE), which is a combination of the IoT technology and the big data processing technology through connection with a cloud server, has emerged. As technology elements, such as “sensing technology”, “wired/wireless communication and network infrastructure”, “service interface technology”, and “security technology” have been demanded for IoT implementation, a sensor network, a machine-to-machine (M2M) communication, machine type communication (MTC), and so forth have been recently researched. Such an IoT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analyzing data generated among connected things. IoT may be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combination between existing information technology (IT) and various industrial applications. 
     In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, MTC, and M2M communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud RAN as the above-described big data processing technology may also be considered to be as an example of convergence between the 5G technology and the IoT technology. 
     As described above, various services can be provided according to the development of a wireless communication system, and thus a method for easily providing such services is required. 
     The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure. 
     SUMMARY 
     Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. 
     Accordingly, an aspect of the disclosure is to provide methods and systems for handling emergency services in a wireless network. A method disclosed herein includes initiating at least one emergency service while operating in a Closed Access Group (CAG) only mode. The method further includes selecting a non-CAG cell from a plurality of non-CAG cells in a Public Land Mobile Network (PLMN). The method further includes performing the initiated at least one emergency service by camping onto the selected non-CAG cell. 
     In an embodiment of the disclosure, wherein the wireless network includes at least one Non-Public Network (NPN) connected to the PLMN, wherein the at least one NPN is at least one CAG cell. 
     In an embodiment of the disclosure, wherein in the CAG only mode, the UE connects only to the at least one CAG cell to access the PLMN, wherein the at least one CAG cell provides at least one private service to the UE. 
     In an embodiment of the disclosure, wherein each of the plurality of non-CAG cells is a public Radio Access Network (RAN) connected to at least one Core Network (CN) of at least one Radio Access Technology (RAT) present in the PLMN. 
     In an embodiment of the disclosure, wherein each non-CAG cell supports the at least one CAG cell and provides at least one normal communication service and the at least one emergency service to the UE. 
     In an embodiment of the disclosure, wherein selecting, by the UE, the non-CAG cell includes: disabling the CAG only mode; determining the plurality of non-CAG cells available in a location of the UE based on at least one signal broadcasted by the plurality of non-CAG cells; and selecting the non-CAG cell from the plurality of non-CAG cells based on at least one factor associated with the at least one signal broadcasted by the plurality of non-CAG cells, wherein the at least one factor includes at least one of signal strength, and reference signal receive power. In an embodiment of the disclosure, wherein the UE selects the non-CAG cell for the initiated at least one emergency service when the UE does not determine the at least one CAG cell in the location, or when the at least one CAG cell connected to the UE does not support the initiated at least one emergency service. 
     In an embodiment of the disclosure, wherein performing, by the UE, the initiated at least one emergency service includes: camping on to the selected non-CAG cell and establishing a Radio Resource Control (RRC) connection with the selected non-CAG cell, wherein the non-CAG cell connects the UE to the associated at least one CN; establishing an emergency Protocol Data Unit (PDU) session with an external data network through the at least one CN by performing an emergency attach procedure with the at least one CN through the selected non-CAG cell; and performing the initiated at least one emergency service over the established emergency PDU session. 
     In an embodiment of the disclosure, the method further comprises: entering, by the UE, into an idle mode on completing the initiated emergency service; remaining, by the UE, in the idle mode for a pre-defined period of time; and enabling, by the UE, the CAG only mode on an expiry of the pre-defined period of time. 
     In an embodiment of the disclosure, wherein the UE enables the CAG only mode by performing a registration update procedure with the at least one CN of the PLMN. 
     In an embodiment of the disclosure, the method further comprising: establishing, by the UE, the emergency PDU session with the at least one CAG cell for performing the initiated at least one emergency service, when the UE is camped on the at least one CAG cell during the CAG only mode; determining, by the UE, a connection loss with the camped at least one CAG cell, while performing the at least one emergency service through the camped at least one CAG cell; and selecting, by the UE, the non-CAG cell for completing the at least one emergency service on determining the connection loss with the camped at least one CAG cell. 
     Accordingly, an aspect of the disclosure is to provide a User Equipment (UE) for managing emergency services in a wireless network, wherein the UE includes a memory and a controller. The controller is configured to initiate at least one emergency service, while the UE is operating in a Closed Access Group (CAG) only mode. The controller is further configured to select a non-CAG cell from a plurality of non-CAG cells in a Public Land Mobile Network (PLMN). The controller is further configured to perform the initiated at least one emergency service by enabling the UE to camp onto the selected non-CAG cell. 
     In an embodiment of the disclosure, wherein the wireless network includes at least one Non-Public Network (NPN) connected to the PLMN, wherein the at least one NPN is at least one CAG cell. 
     In an embodiment of the disclosure, wherein in the CAG only mode, the UE connects only to the at least one CAG cell to access the PLMN, wherein the at least one CAG cell provides at least one private service to the UE. 
     In an embodiment of the disclosure, wherein each of the plurality of non-CAG cells is a public Radio Access Network (RAN) connected to at least one Core Network (CN) of at least one Radio Access Technology (RAT) present in the PLMN. 
     In an embodiment of the disclosure, wherein each non-CAG cell supports the at least one CAG cell and provides at least one normal communication service and the at least one emergency service to the UE. 
     In an embodiment of the disclosure, wherein the controller is further configured to: disable the CAG only mode; determine the plurality of non-CAG cells available in a location of the UE based on at least one signal broadcasted by the plurality of non-CAG cells; and select the non-CAG cell from the plurality of non-CAG cells based on at least one factor associated with the at least one signal broadcasted by the plurality of non-CAG cells, wherein the at least one factor includes at least one of signal strength, and reference signal receive power. 
     In an embodiment of the disclosure, wherein the controller is further configured to; select the non-CAG cell for the initiated at least one emergency service when the UE does not determine the at least one CAG cell in the location, or when the at least one CAG cell connected to the UE does not support the initiated at least one emergency service. 
     In an embodiment of the disclosure, wherein the controller is further configured to: enable the UE to camp on to the selected non-CAG cell and to establish a Radio Resource Control (RRC) connection with the selected non-CAG cell, wherein the non-CAG cell connects the UE to the associated at least one CN; enable the UE to establish an emergency Protocol Data Unit (PDU) session with an external data network through the at least one CN by performing an emergency attach procedure with the at least one CN through the selected non-CAG cell; and perform the initiated at least one emergency service over the established emergency PDU session. 
     In an embodiment of the disclosure, wherein the controller is further configured to: enable the UE to enter into an idle mode on completing the initiated emergency service; enable the UE to remain in the idle mode for a pre-defined period of time; and enable the CAG only mode on an expiry of the pre-defined period of time. 
     In an embodiment of the disclosure, wherein the controller is further configured to enable the CAG only mode by enabling the UE to perform a registration update procedure with the at least one CN of the PLMN. 
     In an embodiment of the disclosure, wherein the controller is further configured to: enable the UE to establish the emergency PDU session with the at least one CAG cell for performing the initiated at least one emergency service, when the UE is camped on the at least one CAG cell during the CAG only mode; determine a connection loss with the camped at least one CAG cell, while performing the at least one emergency service through the camped at least one CAG cell; and select the non-CAG cell for completing the at least one emergency service on determining the connection loss with the camped at least one CAG cell. 
     Accordingly, an aspect of the disclosure is to provide a wireless network system comprising: a Public Land Mobile Network (PLMN) including a plurality of non-Closed Access Group (CAG) cells and at least one Core Network (CN) of at least one Radio Access Technology (RAT); at least one CAG cell coupled to the PLMN, wherein the at least one CAG cell is at least one Non-Public Network (NPN); and a plurality of User Equipments (UEs) supporting the at least one CAG cell and the PLMN, wherein a UE of the plurality of UEs is configured to: initiate at least one emergency service while operating in a CAG only mode; select the non-CAG cell from the plurality of non-CAG cells in the PLMN; and perform the initiated at least one emergency service by camping onto the selected non-CAG cell. 
     In an embodiment of the disclosure, wherein the UE connects only to the at least one CAG cell to access the PLMN in the CAG only mode. 
     In an embodiment of the disclosure, wherein each non-CAG cell supports the at least one CAG cell and provides at least one normal communication service and the at least one emergency service to the UE. 
     In an embodiment of the disclosure, wherein the UE is further configured to: disable the CAG only mode; determine the plurality of non-CAG cells available in a location of the UE based on at least one signal broadcasted by the plurality of non-CAG cells; and select the non-CAG cell from the plurality of non-CAG cells based on at least one factor associated with the at least one signal broadcasted by the plurality of non-CAG cells, wherein the at least one factor includes at least one of signal strength, and reference signal receive power. 
     In an embodiment of the disclosure, wherein the UE is further configured to: camp on to the selected non-CAG cell and to establish a Radio Resource Control (RRC) connection with the selected non-CAG cell, wherein the non-CAG cell connects the UE to the associated at least one CN; establish an emergency Protocol Data Unit (PDU) session with an external data network through the at least one CN by performing an emergency attach procedure with the at least one CN through the selected non-CAG cell; and perform the initiated at least one emergency service over the established emergency PDU session. 
     In an embodiment of the disclosure, wherein the at least one CN is configured to perform a handover of the UE from the at least one CAG cell to the non-CAG cell for completing the at least one emergency service, when the UE loses connection with the at least one CAG cell while performing the at least one emergency service through the at least one CAG cell. 
     According to an embodiment of the disclosure, an aspect of the disclosure is to provide methods and systems for handling emergency services in a wireless network. The method comprising: receiving, by a User Equipment (UE), a periodic registration timer value with a “Strictly Periodic Registration Timer Indication” indication from a Core Network (CN); operating, by the UE, a timer in a strictly periodic registration mode in response to the received periodic registration timer value with the “Strictly Periodic Registration Timer Indication” indication; initiating, by the UE, at least one emergency service while the timer is operating; switching, by the UE, behavior of the timer from the strictly periodic registration mode to a normal periodic registration mode on initiating the at least one emergency service; and performing, by the UE, the initiated at least one emergency service on the behavior of the timer being switched. 
     In an embodiment of the disclosure, wherein in the strictly periodic registration mode, the UE continues to operate the timer with the periodic registration timer value, when the UE moves from an idle mode to a connected mode, and when the UE moves from the connected mode to the idle mode. 
     In an embodiment of the disclosure, wherein in the normal periodic registration mode, the UE terminates the timer, when the UE moves from the idle mode to the connected mode. 
     In an embodiment of the disclosure, wherein in the normal periodic registration mode, the UE resets and restarts the timer, when the UE moves from the connected mode to the idle mode. 
     In an embodiment of the disclosure, a User Equipment (UE) in a wireless network comprising: a memory; and a periodic registration controller coupled to the memory configured to: receive a periodic registration timer value with a “Strictly Periodic Registration Timer Indication” indication from a Core Network (CN); operate a timer in a strictly periodic registration mode in response to the received periodic registration timer value with the “Strictly Periodic Registration Timer Indication” indication; initiate at least one emergency service while the timer is operating; switch behavior of the timer from the strictly periodic registration mode to a normal periodic registration mode on initiating the at least one emergency service; and perform the initiated at least one emergency service on the behavior of the timer being switched. 
     In an embodiment of the disclosure, wherein in the strictly periodic registration mode, the UE continues to operate the timer with the periodic registration timer value, when the UE moves from an idle mode to a connected mode, and when the UE moves from the connected mode to the idle mode. 
     In an embodiment of the disclosure, wherein in the normal periodic registration mode, the UE terminates the timer, when the UE moves from the idle mode to the connected mode. 
     In an embodiment of the disclosure, wherein in the normal periodic registration mode, the UE resets and restarts the timer, when the UE moves from the connected mode to the idle mode. 
     These and other aspects of the example embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating example embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the example embodiments herein without departing from the spirit thereof, and the example embodiments herein include all such modifications. 
     Before undertaking the detailed description below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation, the term “or,” is inclusive, meaning and/or, the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like, and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. 
     Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. 
     Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure. 
     Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. 
     Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. 
     Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
         FIGS. 1A-1D  depict are sequence diagrams depicting conventional methods of handling emergency services while performing a periodic registration procedure using a periodic registration timer and a periodic registration timer with “Strictly Periodic Registration Timer Indication”; 
         FIGS. 2A, 2B, and 2C  depict a wireless communication system/wireless network for handling emergency services, wherein the wireless network includes at least one non-public network (NPN), and at least one public network, according to an embodiment of the disclosure; 
         FIG. 3  depicts the UE configured to perform the emergency services by camping on a non-CAG cell, according to an embodiment of the disclosure; 
         FIGS. 4A and 4B  depict an example scenario of handling the emergency scenarios in the wireless network, according to an embodiment of the disclosure; 
         FIG. 5  is an example sequence diagram depicting the handling of the emergency service using the non-CAG cells, according to an embodiment of the disclosure; 
         FIG. 6  is an example sequence diagram depicting the handling of the emergency service using the non-CAG cells in the wireless network that includes a Standalone-NPN (SNPN), according to an embodiment of the disclosure; 
         FIG. 7  is a flow diagram depicting a method for handling the emergency services in the wireless network including the NPN and the PLMN, according to an embodiment of the disclosure; 
         FIGS. 8A and 8B  depict another wireless network/wireless communication system for handling the emergency services while performing periodic registration procedures, according to an embodiment of the disclosure; 
         FIG. 9A  depicts the wireless network handling the emergency services by switching the behavior of the PTAU timer to the normal periodic registration timer, wherein the wireless network includes a 5G system (5GS), according to an embodiment of the disclosure; 
         FIG. 9B  depicts a UE configured to handle the emergency services by switching the behavior of the PTAU timer to the normal periodic registration timer, according to an embodiment of the disclosure; 
         FIG. 10  is an example sequence diagram depicting the handling of the emergency service by enabling the PTAU timer supporting the “Strictly Periodic Registration Timer Indication” to act as the normal periodic registration timer, according to an embodiment of the disclosure; 
         FIG. 11  is a flow diagram depicting a method for handling the emergency services by switching the behavior of the timer, according to an embodiment of the disclosure; 
         FIGS. 12A, 12B, and 12C  are flow diagrams depicting handling of at least one priority service in the wireless network, according to an embodiment of the disclosure; 
         FIG. 13  schematically illustrates the base station according to an embodiment of the disclosure; and 
         FIG. 14  schematically illustrates a user equipment (UE) according to an embodiment of the disclosure. 
     
    
    
     Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. 
     DETAILED DESCRIPTION 
       FIGS. 1A through 14 , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device. 
     The example embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The description herein is intended merely to facilitate an understanding of ways in which the example embodiments herein can be practiced and to further enable those of skill in the art to practice the example embodiments herein. Accordingly, this disclosure should not be construed as limiting the scope of the example embodiments herein. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents. 
     It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
     Embodiments herein disclose methods and systems for handling emergency services in a wireless network. 
     Embodiments herein enable at least one User Equipment (UE) supporting only Closed Access Group (CAG) cell/non-public network (NPN) to connect to at least one non-CAG cell/public cell of at least one public network for accessing the emergency services. 
     Embodiments herein enable the at least one UE to switch behavior of a timer from a periodic registration procedure with a “Strictly Periodic Registration Timer Indication” to a periodic registration procedure/16 pre-release behavior for accessing the emergency services, while performing the periodic registration procedure. 
     The principal object of the embodiments herein is to disclose methods and systems for handling emergency services in a wireless network. 
     Another object of the embodiments herein is to disclose methods and systems for enabling at least one User Equipment (UE) supporting only Closed Access Group (CAG) cell/non-public network (NPN) to access the emergency services by camping onto at least one non-CAG cell/public network cell. 
     Another object of the embodiments herein is to disclose methods and systems for enabling the at least one UE to handle the emergency services, while performing a periodic registration procedure with a timer, wherein the timer behaves a periodic registration timer with a “Strictly Periodic Registration Timer Indication”. 
     Another object of the embodiments herein is to disclose methods and systems for enabling the at least one UE to switch behavior of the timer from the periodic registration timer with the “Strictly Periodic Registration Timer Indication” to a normal periodic registration timer/pre-release 16 behavior for performing the emergency services. 
     Referring now to the drawings, and more particularly to  FIGS. 1A-1D, 2A-2C, 3, 4A-4B, 5-7, 8A-8B, 9A-9B, 10-11, 12A-12C, 13 to 14 , where similar reference characters denote corresponding features consistently throughout the figures, there are shown example embodiments. 
       FIGS. 1A-1D  depict are sequence diagrams depicting conventional methods of handling emergency services while performing a periodic registration procedure using a periodic registration timer and a periodic registration timer with “Strictly Periodic Registration Timer Indication”. 
     According to 3rd Generation Partnership Project (3GPP) TS 24.501 and 3GPP TS 23.122, the UE can support only private network/non-public networks (NPN). The NPNs may be deployed by enterprises to meet and optimize coverage, performance, and security requirements of their business processes. The NPN may use Closed Access Group (CAG) and/or a non-public network identifier to identify a group of subscribers/UEs, who are permitted to use the one or more NPNs (can be referred hereinafter as CAG cell). 
     When the UE supports only the NPN/CAG cell, the UE can connect to only the CAG cell to access public networks (of any Radio Access Technologies (RAT)) for normal services or emergency services. However, coverage of the CAG cell is very limited; therefore the UE, supporting only the CAG cell, can perform the emergency services only in a limited coverage. Further, when the UE initiates an emergency service/call and the at least one CAG cell is not available or the at least one available CAG cell does not support the emergency services, the UE may not able to complete the initiated emergency service. Also, the UE may not able to select any non-CAG cells of any RATs available at a location for performing the emergency service, as the UE supports only the CAG cell. Thus, in conventional approaches, the UE supporting only CAG cell/NPN may not able to perform the emergency services on the non-CAG cells. 
     According to 3GPP TS 24.501, the UE may perform a periodic registration procedure with at least one Core Network (CN) of any RAT to register the location information and update the mobile registration with the CN. The UE may use a periodic registration timer or a periodic registration timer with “Strictly Periodic Registration Timer Indication” for performing the periodic registration procedure. 
     Consider an example scenario as depicted in  FIG. 1A , wherein the UE performs the periodic registration procedure using the periodic registration timer. The UE sends a periodic registration request to the CN and receives a periodic registration timer value of 12 minutes (for example) from the CN. The periodic registration timer value indicates the time value at which the UE has to perform the periodic registration procedure with the CN. On receiving the periodic registration timer value, the UE starts executing/operating a periodic tracking area update (PTAU) timer by applying the received periodic registration timer value (for example: 12 mins). In an example, the PTAU timer behaves as the periodic registration timer. 
     In an example herein, on starting the PTAU timer, the UE may operate in the connected mode for 4 minutes. After 4 minutes, the UE may enter into the idle mode. After 2 minutes, the UE exits from the idle mode and starts data transmission by entering into the connected mode and enters into the idle mode on completion of the data transmission. When the UE enters into the idle mode, the UE restarts the PTAU timer. Thus, the PTAU timer starts from a value of 0 again. Further, the UE may start the data transmission by entering into the connected mode after 3 minutes of restarting the PTAU timer. On completion of the data transmission, the UE enters into the idle mode and again restarts the PTAU timer. The UE may remain in the idle mode till the expiry of the PTAU timer and may start performing the periodic registration procedure. In an example herein, the UE may remain in the idle mode for 12 minutes, as the PTAU timer expires on reaching the value of 12 minutes and may start performing the periodic registration procedure after 12 minutes. Thus, in the conventional approaches, the UE has to restart the periodic registration timer, whenever the data transmission occurs. 
     Consider another example scenario as depicted in  FIG. 1B , wherein the UE performs the periodic registration procedure using the periodic registration timer and initiates the emergency service while the periodic registration time is operating. The UE sends a periodic registration request to the CN and receives a periodic registration timer value of 12 minutes (for example) from the CN. On receiving the periodic registration timer value, the UE starts the PTAU timer by applying the received periodic registration timer value (for example: 12 mins), and the PTAU timer behaves as the periodic registration timer. 
     In an example herein, on starting the PTAU timer, the UE may operate in the connected mode for 4 minutes. After 4 minutes, the UE may enter into the idle mode. After 2 minutes, the UE exits from the idle mode and starts data transmission by entering into the connected mode and enters into the idle mode on completion of the data transmission. When the UE enters into the idle mode, the UE restarts the PTAU timer. Thus, the PTAU timer starts from a value of 0 again. After 3 minutes of restarting the periodic registration timer, the UE may initiate/execute the emergency service by entering into an emergency registered state. Only on the completion of the emergency service, the UE enters into the idle mode. When the UE enters into the idle mode, the UE restarts the PTAU timer. The UE may remain in the idle mode till the expiry of the PTAU timer and will perform detach procedure on expiry of PTAU timer. In an example herein, the UE may remain in the idle mode for 12 minutes, as the PTAU timer expires by reaching the value of 12 minutes. Within 12 minutes of time, the UE may receive the response/call back from the CN in response to the executed emergency service. Further, the UE performs a detach procedure to exit from the emergency state on the expiry of the PTAU timer. Thus for normal periodic timer the UE gets full 12 mins (PTAU timer value duration) to remain registered with the network to receive any possible emergency call back from the network. 
     Consider an example scenario as depicted in  FIG. 1C , wherein the UE performs the periodic registration procedure using the periodic registration timer with the “Strictly Periodic Registration Timer Indication”. The UE sends a periodic registration request to the CN and receives a periodic registration timer value of 12 minutes (for example) from the CN. The periodic registration timer value indicates time value at which the UE has to perform the periodic registration procedure with the CN. On receiving the periodic registration timer value, the UE starts executing/operating the PTAU timer by applying the received periodic registration timer value (for example: 12 mins) with the “Strictly Periodic Registration Time Indication”. In an example, the PTAU behaves as the periodic registration timer with the “Strictly Periodic Registration Time Indication”, wherein the “Strictly Periodic Registration Time Indication” indicates that the PTAU timer does not require to re-start if the UE enters into the connected mode or the idle mode during the received periodic registration timer value (i.e. while the PTAU timer is operating). 
     In an example, on starting the PTAU timer, the UE remains in the connected mode for 4 minutes and enter into the idle mode. After 2 minutes of entering into the idle mode, the UE starts the data transmission by entering into the connected mode. The UE may enter into the idle mode on completion of the data transmission. The UE may continue the periodic registration timer without restating it when the UE enters into the idle mode. Further, after 3 minutes of entering into the idle mode, the UE starts the data transmission by entering into the connected mode. The UE may enter into the idle mode on completion of the data transmission and remain in the idle mode till the expiry of the PTAU timer. In an example scenario, the UE may remain in the idle mode for 3 minutes, as the periodic registration timer expires after 3 minutes of the UE entering into the idle mode (that is after 12 minutes of initiating the periodic registration timer). The expiry of the periodic registration timer triggers the UE to perform the registration procedure. The UE strictly performs the registration procedure after 12 minutes (i.e., after the expiry of the PTAU timer), irrespective of a number of times the UE had been to the connected mode during the 12 minutes duration. Thus, in the conventional approaches, the UE performing periodic registration procedure with the “Strictly Periodic Registration Timer Indication” does not restart the timer on completing each data transmission i.e. each time UE goes to connected mode the PTAU timer is not stopped and neither started again when the UE goes back to IDLE mode. 
     Consider an example scenario as depicted in  FIG. 1D , wherein the UE performs the periodic registration procedure using the periodic registration timer with the “Strictly Periodic Registration Timer Indication”. The UE sends a periodic registration request to the CN and receives a periodic registration timer value of 12 minutes (for example) from the CN. On receiving the periodic registration timer value, the UE starts executing/operating the PTAU timer by applying the received periodic registration timer value (for example: 12 mins) with the “Strictly Periodic Registration Time Indication”. In an example, the PTAU timer behaves as the periodic registration timer with the “Strictly Periodic Registration Time Indication”. 
     In an example herein, on starting the PTAU timer, the UE remains in the connected mode for 4 minutes and enters into the idle mode. After 2 minutes of entering into the idle mode, the UE starts the data transmission by entering into the connected mode. The UE may enter into the idle mode on completion of the data transmission. The UE may continue the periodic registration timer without restarting it when the UE enters into the idle mode. Further, after 3 minutes of entering into the idle mode, the UE executes the emergency service (for example, when the UE faces an authentication procedure failure) by entering into the emergency registered state. Once the emergency service is completed, the UE enters into the idle mode and remains in the idle mode until the expiry of the periodic registration timer. In an example scenario, the UE will remain in the idle mode only for 3 minutes. The expiry of the periodic registration timer triggers the UE to initiate the deregistration procedure. However, the duration/time in which the UE can remain in the idle mode has been drastically reduced due to the “Strictly Periodic Registration Timer Indication”. Therefore, the UE may obtain a less period of time (in the current example, only 3 minutes when compared to 12 minutes as discussed in  FIG. 1 b   ) for receiving the emergency response or call back from the core network (CN). 
     Further, according to the current 3GPP TS 24.501, the UE may perform a registration procedure to access mission critical services (MCSs). The UE sends a registration request message to the CN for an initial registration for the MCSs. If the UE does not receive any response from the network, the UE enters into a 5GMM DEREGISTERED.REGISTRATION.ATTEMPTING-REGISTRATION state and starts a timer T3511. The UE re-starts the registration procedure after an expiry of a timer T3511 (for example: after 10 seconds). After a certain number of unsuccessful attempts, the UE starts a timer T3502. On expiry of the timer T3502 (for example: after 14 minutes), the UE initiates a next registration procedure. However, the UE may not able to initiate the registration procedure on receiving a request for the MCSs when the timer T3511 or T3503 is operating. Similarly, the MCSs are delayed, when the UE is in 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE state and when the timer T3510 or T3502 is operating. 
     In addition, when a service request procedure fails a certain number of times after the registration procedure, the UE starts a T3525 timer. In such a case, the UE is not allowed to initiate the next service request procedure for the MCSs till an expiry of the T3525 timer. Further, the UE may start a T3346 timer on the successful service request procedure. In such a case, the UE may not able to initiate any mobility management or connection management procedure till the expiry of the T3346 timer. 
     Thus, in the conventional approaches, the MCS is delayed for a considerable duration of time. This may lead to serious consequences during an emergency scenario. 
       FIGS. 2A, 2B, and 2C  depict a wireless communication system/wireless network  200  for handling emergency services, wherein the wireless network  200  includes at least one non-public network, and at least one public network, according to an embodiment of the disclosure. The wireless network  200  referred herein can be configured for handling emergency services during an emergency event/scenario. The emergency services can support real-time, high priority total conversation services such as, but not limited to, voice calls, video calls, real-time text messages, IP Multimedia Subsystem (IMS) emergency calls, or the like. Examples of the emergency event can be, but is not limited to, a medical event, a criminal attack, a natural disaster, an accident, an injury, and so on. 
     The wireless network  200  includes at least one Public Land Mobile Network (PLMN)  202 , at least one non-public network (NPN)  204 , and a plurality of User Equipments (UEs)  206 . The PLMN  202  can be configured to provide PLMN services to the UEs  206  in a specific region. The PLMN services include normal communication services and the emergency services. Examples of the normal communication services can be, but is not limited to, a streaming service (streaming of multimedia data such as audio, video, text and so on), a file download service, a carousel service (a service for combining file download service and streaming service), a television (TV) service, an Internet Protocol (IP) Multimedia Subsystem (IMS) service, a non-3rd Generation Partnership Project (non-3GPP) service (for example: firewalling or the like), a short messaging service, a Multimedia Messaging Service (MMS), and so on. Examples of the emergency services can be, but is not limited to, an emergency call to local Fire/Ambulance/Police stations, an IMS call, text messages, and so on. The PLMN  202  can be operated by a mobile network operator (MNO) and can be identified using a PLMN_identifier (PLMN_ID). Embodiments herein use the terms such as “PLMN”, “cellular network”, “public network”, “3GPP access network”, and so on interchangeably to refer to a network that provides the emergency services, and the normal communication services in a given region. 
     As depicted in  FIG. 2B , the PLMN  202  includes one or more different public cellular networks/Radio Access Technologies (RATs)  202   a  such, as, but not limited to, a Long Term Evolution (LTE) network, an advanced LTE network, a New Radio (NR)/5G network, a Narrowband Internet of Things (NB-IoT), a Universal Mobile Telecommunications Service (UMTS), a Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN) system or any other next generation networks. 
     As depicted in  FIG. 2C , a RAT  202   a  of the PLMN  202  may include a plurality of Radio Access Networks (RANs)/public RANs  202   b , and at least one Core Networks (CN)  202   c . The RAN  202   b  and the CN  202   c  may comprise of one or more processors/Central Processing Units (CPUs), a memory, a storage, a transceiver, and so on, for performing at least one intended function/operation. The RAN  202   b  may comprise of nodes/Base Stations (BSs) such as, but not limited to, evolved nodes (eNBs), New Radio nodes (gNBs), and so on. The RAN  202   b  can be configured to connect the at least one UE  206  to the CN  202   c . The RAN  202   b  can be configured to perform radio resource management functions such as, but not limited to, radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to the UE  206  in uplink/downlink (scheduling), and so on. Embodiments herein use the terms such as “RAN”, “public RAN”, “PLMN RAN”, “public cell”, and so on interchangeably to refer to an access node of the PLMN  202  that connects the UEs  206  to the at least one CN  202   c.    
     The CN  202   c  referred herein can be at least one of an Evolved Packet Core (EPC), a 5G core (5GC) network, or the like. The CN  202   c  can be connected to the RAN  202   b  and an external data network. Examples of the external data network can be, but not limited to, the Internet, a Packet Data Network (PDN), an Internet Protocol (IP) Multimedia Core Network Subsystem, and so on. The CN  202   c  can be configured to connect the UEs  206  (that are connected to the associated RAN  202   b ) to the external data network for the communication services or the emergency services. Embodiments herein use the terms such as “CN”, “public CN”, “PLMN CN”, and so on interchangeably to refer to a core network of the PLMN  202  that connects the UEs  206  to the external data network. In an example, as depicted in  FIG. 2C , the PLMN  202  includes a 5G system (5GS)  202   a  and a LTE network  202   b . The 5GS includes one or more gNBs/public cells  202   b  connected to a 5GC network  202   c . The LTE network  202   b  includes one or more eNBs/public cells connected to an EPC network  202   c.    
     The NPN(s)  204  can be configured to provide coverage and private services to the UEs  206  present within a location/premises such as, but is not limited to, an organization, an enterprise, an industry/factory, a campus, a room, a floor, a hospital, a stadium, an airport, a shopping center, and so on. The private services can include services that are defined by the respective premises. Examples of the private services can be, but is not limited to, a streaming service (streaming of multimedia data such as audio, video, text and so on), a file download service, a mission-critical service (for example; autonomous driving, control of a smart grid, smart operation of industrial automation processes, or any other service which requires different levels of security), and so on. The NPN  204  can be deployed as a non-standalone NPN, or a standalone NPN (SNPN). The non-standalone NPN can be deployed in conjunction with the PLMN  202  using a network slicing and/or a Closed Access Group (CAG) cell (as specified in 3GPP TS 23.501). The network slicing provides dedicated data network names (DNNs) networks, or one or more network slice instances that can make the NPN  204  available to the UEs  206  via the PLMN  202 . The stand-alone NPN may be deployed without requiring the support of the PLMNs  202 . The stand-alone NPN may use the CAG and/or a non-public network identifier to identify a group of subscribers/UEs, who are permitted to access the NPN. The CAG may be used by the NPN  204  to prevent users/UEs from automatically selecting and registering from a location/region/area, which does not provide access to the NPNs  204  for the UEs  206 . The CAG may be used by the NPN  204  to prevent users/UEs from automatically selecting and registering from a location/region/area, where the UEs  206  are not allowed to access the NPNs  204 . The NPN can be assigned a CAG Identifier (CAG ID) to identify it. Embodiments herein use the terms “CAG Identifier” and “non-public network identifier” interchangeably to refer to the CAG ID. The CAG ID can be the CAG-ID and/or NPN-ID. Embodiments herein use the terms such as, but not limited to, “NPN”, “private network”, “public network integrated NPN”, “non-3GPP access network”, “SNPN”, “CAG cells”, and so on interchangeably to refer to a network that confines the communication services within boundaries of the defined premises for the UEs  206 . Embodiments herein are further explained considering the NPN  204  as the SNPN for example, but it may be obvious to a person skilled in the art that the non-standalone NPN can also be considered. 
     As depicted in  FIG. 2B , the NPN  204  includes at least one non-public RAN  204   a , and a non-public Core Network (CN)  204   b . The non-public RAN referred herein can be a CAG cell including at least one of 3GPP access nodes, non-3GPP access nodes, and so on. Examples of the 3GPP access nodes can be, but not limited to, eNBs, gNBs, and so on. Examples of the non-3GPP access nodes can be, but is not limited to, a Local Access Network (LAN) node, a Wireless LAN (WLAN) node, a Wi-Fi node, and so on. The non-public RAN  204   a  can be configured to broadcast CAG IDs of the NPN  204  to the UEs  206 . The UE  206  can identify and connect to the corresponding NPN  204  using the broadcasted CAG IDs, if the broadcasted CAG ID is present in an allowed list of CAG IDs configured for the UE  206 . In an embodiment, the non-public RAN  204   a  can be configured to connect the UE  206  to the non-public CN  204   b . In an embodiment, the NPN  204  can share the non-public RAN  204   a  with the PLMN  202  by assigning its own cell identities and tracking area codes to the non-public RAN  204   a . In such a case, the non-public RAN of the NPN  204  can be a RAN of the PLMN  202  including an assistance of the CAG IDs. Embodiments herein use the terms such as “non-public RAN”, “CAG cell RAN”, “CAG cell”, “SNPN RAN”, “non-public/SNPN BS”, “private RAN/BS”, and so on interchangeably to refer to a node that broadcasts the CAG IDs to the UE  206  and connects the authorized UE  206  to the PLMN  202 . 
     The non-public CN  204   b  referred herein can be at least one of an EPC network, a 5GC network, or the like. The non-public CN  204   b  can be connected to the non-public RAN  204   a , a private data network/private enterprise network, and the CN  202   c  of the PLMN  202 . The private data network/private enterprise may be operated by at least one of the enterprise, the organization, the industry, an external entity, or the like. Examples of the private data network can be, but is not limited to, an Intranet, a cloud platform, a server, and so on. In an embodiment, the non-public CN  204   b  can be configured to connect the UE  206  (that is connected to the non-public RAN  204   a ) to the private data network for the private services defined within the premises. In an embodiment, the non-public CN  204   b  can also be configured to connect the UE  206  (that is connected to the non-public RAN  204   a ) to the PLMN  202  for the PLMN services (i.e., the normal communication services and the emergency services). In an embodiment, the NPN  204  can share control plane functionalities of the non-public CN  204   b  with the PLMN  202 . Embodiments herein use the terms such as “non-public CN”, “private CN”, and so on interchangeably to refer to a core network of the NPN  204 . 
     In an embodiment, the NPN  204  including the CAG cell/non-public RAN  204   a  and the non-public CN  204   b  may be referred hereinafter as the CAG cell  204  through the document. 
     As depicted in  FIGS. 2A-2C , the UE(s)  206  can be a user device that is capable of supporting the PLMN  202  and the NPN/CAG cell  204 . Examples of the UE  206  can be, but is not limited to, a mobile phone, a smartphone, a tablet, a phablet, a personal digital assistant (PDA), a laptop, a computer, a wearable computing device, a vehicle infotainment device, an Internet of Things (IoT) device, a Virtual Reality (VR) device, a Wireless Fidelity (Wi-Fi) router, a USB dongle, a sensor, a robot, an auto-guided vehicle, and so on. The UE  206  can include one or more processors/Central Processing Units (CPUs), a memory, a transceiver, and so on, for performing at least one intended function/operation. 
     The UE  206  can be configured to register with the PLMN  202  (that can be a home PLMN (HLPMN)) and obtain the allowed list of CAG IDs/permission to access the CAG cells  204  and other permission/subscription details from the PLMN  202 , wherein the CAG IDs identify the CAG cells  204 . The UE  206  can select the CAG cell based on the received allowed list of CAG IDs for accessing the private services and for connecting to the PLMN  202  for the PLMN services. The UE  206  can automatically select the NPN/CAG cell  204  corresponding to one of the received allowed list of CAG IDs that is available in the location. The UE  206  can also provide the received allowed list of CAG IDs to the user and allow the user to select the NPN/CAG cell  204  corresponding to one of the allowed list of CAG LDs. 
     In an embodiment, the UE  206  can be configured to operate in a CAG only mode/CAG only feature. In the CAG only mode operation, the UE  206  can connect only to the allowed CAG cell  204  to access the PLMN  202  for the PLMN services. Embodiments herein use the terms such as “CAG only mode”, “NPN access mode”, “SNPN access mode”, “SNPN support capability” and so on interchangeably to refer to a mode/state in which the UE  206  can only connect to the NPN/CAG cell  204 . 
     In order to operate in the CAG only mode, the UE  206  sends a registration request to the CN  202   c  of the PLMN  202  through the public RAN  202   b  that supports the CAG cell. The public RAN  202   b  can be referred herein after as a non-CAG cell  202   b  through the document. Embodiments herein use the terms such as “non-CAG cell”, “non-CAG RAN”, “RAN”, “public RAN”, “PLMN RAN”, “public cell”, and so on, interchangeably through the document. The non-CAG cell/RAN  202   b  can be a public cell/RAN, which can be accessed by the UE  206  to obtain the normal communication service (for example: IMS voice call, internet services, and so on) provided by the public PLMN  202 . The registration request may specify the CAG cell  204  selected by the UE  206  to connect and other permission/subscription details of the UE  206 . The CN  202   c  of the PLMN  202  checks if the UE  206  has the permissions to connect to the selected CAG cell  204  based on the allowed list of CAG IDs configured for the UE  206  (according to 3GPP TS 24.501 specification). If the UE  206  has the permissions to connect to the selected CAG cell  204 , the CN  202   c  of the PLMN  202  sends a registration accept message including an indicator, which can indicate to the UE  206  to operate in the CAG only mode. 
     The UE  206 , which is enabled to operate in the CAG only mode, can initiate the emergency services in the emergency scenarios where the authentication of the UE  206  fails or the authentication of the UE  206  may not be performed. In an embodiment, the UE  206  can complete/perform the emergency services on the connected CAG cell  204 , if the connected CAG cell  204  supports the emergency services. In such a case, the connected CAG cell  204  allows the UE  206  to connect to the CN  202   b  for performing/completing the emergency services. 
     In an embodiment, the UE  206  can be configured to operate in an emergency mode on initiating the emergency services. In an embodiment, the UE  206  can be configured to operate in the emergency mode, if the connected CAG cell  204  does not support the initiated emergency services or if the CAG cells  204  are not available in the location of the UE  206  when the UE  206  initiates the emergency services. In the emergency mode, the UE  206  connects to at least one non-CAG cell/public RAN  202   b  of the PLMN  202  for availing the emergency services. The emergency mode can be a limited mode that is enabled only on the initiation of the emergency services. Further, performing the emergency services in the emergency mode can be subjected to local regulation. 
     In order to be operated in the emergency mode, the UE  206  disables the CAG only mode (i.e. deselects the connected CAG cell for the emergency service) and sends an indication to the CN  202   c  of the PLMN  202  indicating that the UE  206  is not operating in the CAG only mode. On receiving the indication, the CN  202   c  of the PLMN  202  enables the UE  206  to operate in the emergency mode. 
     In the emergency mode, the UE  206  determines the one or more non-CAG cells  202   b  of the PLMN  202  available in the location of the UE  206  based on signals broadcasted by the one or more non-CAG cells  202   b  of the PLMN  202 . The UE  206  selects the non-CAG cell  202   b  from the determined one or more non-CAG cells  202   b  that connects to the at least one CN  202   c  of the PLMN  202 . The UE  206  attaches to the selected non-CAG cell  202   b  by establishing a Radio Resource Control (RRC) connection with the selected non-CAG cell  202   b . On attaching to the selected non-CAG cell  202   b , the UE  206  performs an emergency attach procedure with the CN  202   c  of the selected non-CAG cell  202   b  and establishes an emergency Protocol Data Unit (PDU) session with the external data network through the CN  202   c . The UE  206  performs the emergency service over the established emergency PDU session. In an embodiment, in a 5G network, the emergency attach procedure may be referred to a registration performed with 5GS registration type “emergency registration” in the REGISTRATION REQUEST message. In an embodiment, in an Evolved Packet System (EPS)/LTE, the emergency attach procedure may be referred to attached for emergency bearer services. The UE  206  may be attached for the emergency bearer services, if the UE  206  has only a Public Data Network (PDN) connection for the established emergency bearer services. 
     In an embodiment, the UE  206  may establish the PDU session with the connected CAG cell  204  for performing the initiated emergency service. The UE  206  then selects the non-CAG cell  202   b  for completing the initiated emergency service. 
     In an embodiment, the CN  202   c  of the PLMN  202  enables the UE  206  to switch into the emergency mode from the CAG only mode, when the UE  206  loses the connection with the CAG cell  204  during an ongoing emergency service or when the emergency service is established. In the emergency mode, the CN  202   c  may handover the UE  206  from the connected CAG cell  204  to the non-CAG cell  202   b  of the PLMN  202  for completing the on-going/established emergency service. 
     On completion or release of the emergency service, the UE  206  enters into an idle mode and remains in the idle mode for a pre-defined period of time. In an embodiment, the period of time/value of the time can be pre-defined based on an implementation of the UE  206 . In an example, the UE  206  may define the period of time in such a way that the period of time has to be long enough in case an emergency personal wants to re-initiate the emergency service with the user of the UE  206 , if the initiated emergency service by the user of the UE  206  is dropped. In the idle mode, the UE  206  does not establish the RRC connection with any of the CAG cell  204  or the non-CAG cell  202   b . Once the pre-defined period of time has passed, the UE  206  enables the CAG only mode automatically or by performing a registration update procedure with the CN  202   c  of the PLMN  202 . 
       FIGS. 2A, 2B, and 2C  depict exemplary units/components of the wireless network  200 , but it is to be understood that other embodiments are not limited thereon. In other embodiments, the wireless network  200  may include less or a greater number of units. Further, the labels or names of the units are used only for illustrative purpose and does not limit the scope of the embodiments herein. One or more units can be combined together to perform same or substantially similar function in the wireless network  200 . 
       FIG. 3  depicts the UE  206  configured to perform the emergency services by camping on the non-CAG cell  202   a , according to an embodiment of the disclosure. 
     The UE  206  includes a memory  302 , a communication unit  304 , a display  306 , and a controller  308 . The UE  206  can also include at least one transceiver, a processing circuitry, a storage unit, an input/output (I/O) module, and so on (not shown). 
     The memory  302  can store at least one of the PLMN IDs, the allowed list of CAG IDs, and so on. Examples of the memory can be, but not limited to, NAND, embedded Multi Media Card (eMMC), Secure Digital (SD) cards, Universal Serial Bus (USB), Serial Advanced Technology Attachment (SATA), solid-state drive (SSD), and so on. Further, the memory  302  may include one or more computer-readable storage media. The memory  302  may include one or more non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory  302  may, in some examples, be considered a non-transitory storage medium. The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term “non-transitory” should not be interpreted to mean that the memory  302  is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache). 
     The communication unit  304  can be configured to enable the UE  206  to connect with at least one of the NPN/CAG cell  204 , and the PLMN  202  over an interface. Examples of the interface can be, but is not limited to, a wired interface, a wireless interface (for example: an air interface, an Nu interface, or the like), a wireless fronthaul interface, a wired or wireless backhaul interface, or any structure supporting communications over a wired or wireless connection. 
     The display  306  can be configured to enable the user to interact with the UE  206 . The display  306  can also be configured to display the PLMN_IDs and the CAG IDs to the user. The display  306  can also be configured to allow the user to select the PLMN  202  corresponding to one of the PLMN IDs and the CAG cell  204 , corresponding to one of the CAG IDs. 
     The controller  308  can be at least one of a single processer, a plurality of processors, multiple homogeneous or heterogeneous cores, multiple Central Processing Units (CPUs) of different kinds, microcontrollers, special media, and other accelerators. The controller  308  can be configured to handle the emergency services by enabling the UE  206  to camp onto the at least one non-CAG cell  202   b  of the PLMN  202 . 
     The controller  308  includes a reception module  308   a , a CAG-only mode enabling module  308   b , an emergency mode enabling module  308   c , and a mode switching module  308   d.    
     The reception module  308   a  can be configured to receive subscription/permission details from the PLMN  202 , while subscribing/registering with the PLMN  202 . The permission details can be, but not limited to, the allowed list of CAG IDs/allowed CAG list (i.e. a list of CAG Identifiers corresponding to the NPN/CAG cells  204  that the UE  206  is allowed to access); and optionally, a CAG-only indication whether the UE  206  is only allowed to access the PLMN  202  via the CAG cells  204  (according to 3GPP TS 38.304). The reception module  308   a  stores the received permission details in the memory  302 . 
     The CAG-only mode enabling module  308   b  can be configured to enable the UE  206  to operate in the CAG only mode. In the CAG only mode, the UE  206  can connect only to the CAG cell  204  to access the at least one CN  202   c  of the PLMN  202  for the normal communication services and/or the emergency services. The CAG-only mode enabling module  308   b  can perform the registration procedure with the at least one CN  202   c  of the PLMN  202  for enabling the UE  206  to operate in the CAG only mode, according to the 3GPP TS 24.501. 
     For enabling the UE  206  to operate in the CAG only mode, the CAG-only mode enabling module  308   b  uses the received allowed list of CAG IDs for selecting the at least one CAG cell  204  automatically or manually (i.e. allowing the user to select one of the CAG IDs corresponding to the CAG cell). The CAG-only mode enabling module  308   b  sends a registration request in a Non-Access Stratum (NAS) message to the CN  202   c  through the associated public-RAN  202   b  to enable the UE  206  to operate in the CAG only mode. The CN  202   c  verifies if the UE  206  is allowed to access the selected CAG cell  204  using the maintained permission details of the UE  206  (i.e. according to the 3GPP TS 24.501). If the UE  206  is allowed to access the selected CAG cell  204 , the CN  202   c  of the PLMN  202  sends a registration accept in the NAS message with the indication to the UE  206 . The indication indicates to the UE  206  that the UE is to operate in the CAG only mode. Thereby, the UE  206  can connect only to the CAG cell  204  for accessing the at least one CN  202   c  of the PLMN  202 . 
     The emergency mode enabling module  308   c  can be configured to enable the UE  206  to operate in the emergency mode on initiating the emergency services. In an embodiment, in the emergency mode, the UE  206  can connect to any one of the non-CAG cells/public RANs  202   b  of the PLMN  202  to access any one of the CNs  202   c  of the PLMN  202 . In an embodiment, the emergency mode enabling module  306  can enable the UE  206  to operate in the emergency mode, if the connected CAG cell does not support the initiated emergency services. In an embodiment, the emergency mode enabling module  306  can enable the UE  206  to operate in the emergency mode, if the UE  206  is not able to identify and connect to the CAG cell  204  available at the location for performing the initiated emergency services. 
     The emergency mode enabling module  308   c  may receive a request from the user through the display  306  for the emergency service (for example; to make a call to ambulance). In response to the received request, the emergency mode enabling module  308   c  initiates the requested emergency service. On initiating the requested emergency service, the UE  206  disables the CAG only mode by allowing the UE  206  to locally detach from the connected CAG cell  204 , thereby the UE  206  enters into the emergency mode. 
     On disabling the CAG only mode, the emergency mode enabling module  308   c  determines/searches for the one or more non-CAG cells  202   b  of the PLMN  202  that are available in the location of the UE  206 . The emergency mode enabling module  308   c  determines the one or more non-CAG cells  202   b  based on the signals broadcasted by the one or more non-CAG cells  202   b . The emergency mode enabling module  308   c  then selects the non-CAG cell  202   b  from the determined one or more non-CAG cells  202   b  based on at least one factor. Examples of the factor can be, but not limited to, signal strength, reference signal strength power (RSRP), and so on. 
     Once the non-CAG cell  202   b  of the PLMN  202  is selected, the emergency mode enabling module  308   c  enables the UE  206  to connect to/camp on to the selected non-CAG cell  202   b . The emergency mode enabling module  308   c  further enables the UE  206  to establish the RRC connection with the camped non-CAG cell  202   b . The non-CAG cell  202   b  connects the UE  206  to the associated CN  202   c  in the PLMN  202 . The emergency mode enabling module  308   c  then enables the UE  206  to perform the emergency attach procedure with the CN  202   c  through the connected non-CAG cell  202   b . In the emergency attach procedure, the emergency mode module  3038   c  enables the UE  206  to send an emergency attach request to the CN  202   c  through the connected non-CAG cell  202   b . The CN  202   c  establishes the emergency PDU session between the external data network and the UE  206  without authenticating the UE  206 , as it receives the emergency attach request. Once the emergency PDU session is established, the emergency mode enabling module  308   c  enables the UE  206  to perform the initiated emergency service over the established PDU session. Thus, the UE  206  supporting the CAG only mode can perform the emergency services using the non-CAG cells  202   b.    
     The mode switching module  308   d  can be configured to enable the UE  206  to enter into the idle mode on completion of the initiated emergency service using the non-CAG cell  202   b . In the idle mode, the UE  206  can support the CN  202   c  of the PLMN  202 . The mode switching module  308   d  can enable the UE  206  to remain in the idle mode for the pre-defined period of time. On the expiry of the pre-defined period of time, the mode switching module  308   d  enables the CAG only mode for the UE  206 . In an embodiment, the mode switching module  308   d  enables the CAG only mode by itself that is without communicating with the PLMN  202 . In an embodiment, the mode switching module  308   d  enables the CAG only mode by performing the registration updating procedure with the CN  202   c  of the PLMN  202 . 
       FIG. 3  depicts exemplary units/components of the UE  206  configured for performing the emergency services using the non-CAG cells  202   b , but it is to be understood that other embodiments are not limited thereon. In other embodiments, the UE  206  may include less or a greater number of units. Further, the labels or names of the units are used only for illustrative purpose and does not limit the scope of the embodiments herein. One or more units can be combined together to perform same or substantially similar function in the UE  206 . 
       FIGS. 4A and 4B  depict an example scenario of handling the emergency scenarios in the wireless network  200 , according to an embodiment of the disclosure. Consider an example scenario, wherein the PLMN  202  includes a 5G system (5GS)  202   a , and an LTE system/Evolved Packet System (EPS)  202   a  and the at least one CAG cell/NPN  204  is connected to the 5GS  202   a . The 5 GS  202   a  includes one or more gNBs/non-CAG cells  202   b  connected to the 5GC network  202   c , and the LTE system  202   a  includes the one or more non-CAG cells  202   b  connected to the EPC network  202   c . The 5GC  202   c  may include an access and mobility management function (AMF)  402 , and other modules such as, but not limited to, an authentication server function (AUSF), a unified data management (UDM), and so on for performing the at least one intended function. The AMF  402  is configured to support functions such as, but not limited to, termination of NAS signaling, NAS ciphering and integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management, and so on. 
     In such a scenario, the UE  206  initiates the registration procedure with the 5GC  202   c , such that the UE  206  operates in the CAG only mode. The UE  206  selects the CAG cell  204  for which the UE has the permissions to access. Thereafter, the UE  206  sends the registration request in the NAS message to the AMF  402  of the 5GC  202   c  through one of the gNBs/non-CAG cell  202   b  for configuring the UE  206  to operate in the CAG only mode. The AMF  402  may verify the permissions of the UE  206  to allow the selected CAG cell and configure the UE  206  to operate in the CAG only mode when the UE  206  has the permissions to access the selected CAG cell  204 . Thus, in the CAG only mode, the UE  206  can connect only to the CAG cell  204  to access the 5GS  202   a  of the PLMN  202  for the 5GS/PLMN services. 
     The UE  206 , configured to operate in the CAG only mode, may initiate the emergency services during the emergency event. In an example herein, consider that the UE  206  supporting the CAG only mode receives a request from the user to make an emergency call to a fire station and the UE  206  does not find the CAG cell  206  to perform the emergency call. In such a scenario, embodiments herein enable the UE  206  to disable the CAG only mode and to connect to the one of the non-CAG cells  202   b  of the PLMN  202  to perform the emergency call. 
     For performing the emergency call, the UE  206  performs a search to determine the available non-CAG cells  202   b  of the PLMN  202  in the location of the UE  206 , wherein non-CAG cells  202   b  may connect to the 5GC  202   c  of the 5GS  202   a  or to the EPC  202   c  of the LTE. In an example herein as depicted in  FIG. 4A , consider that the UE  206  determines the non-CAG cell/gNB  202   b  connected to the 5GC  202   c  and selects the determined non-CAG cell  202   b  for performing the emergency call. The UE  206  connects to/camp on to the selected non-CAG cell/gNB  202   b . The UE  206  performs the emergency attach procedure with the AMF  402  of the 5GC  202   c  through the connected non-CAG cell/gNB  202   b  and establishes the emergency PDU session with the external data network through the 5GC  202   c . On establishing the PDU session, the UE  206  can perform the emergency call to the fire exchange over the established emergency PDU session. 
     In an example herein as depicted in  FIG. 4B , consider that the UE  206  determines the non-CAG cells/eNBs  202   b  connected to the EPC  202   c  and selects the one of the determined non-CAG cells/eNBs  202   b  based on the associated signal strength for performing the emergency call. The UE  206  connects to/camp on to the selected non-CAG cell/eNB  202   b . The UE  206  performs the emergency attach procedure with the EPC  202   c  through the connected non-CAG cell/eNB  202   b  and establishes the emergency PDU session with the external data network through the EPC  202   c . On establishing the PDU session, the UE  206  can perform the emergency call to the fire station over the established emergency PDU session. Thus, the UE  206 , configured to operate in the CAG only mode, can also camp on the non-CAG cells (supporting different RATs) only during the emergency events for performing the emergency services. 
       FIG. 5  is an example sequence diagram depicting the handling of the emergency service using the non-CAG cells  202   b , according to an embodiment of the disclosure. In an example herein, consider that the CAG cell/NPN  204  is connected to the 5GS of the PLMN  202 . The 5GS of the PLMN  202  includes a plurality of non-CAG cells/gNBs  202   b , and the 5GC  202   c.    
     At step  501 , the UE  206  registers with the AMF  402  of the 5GC  202   c  to be configured to operate in the CAG only mode. In the CAG only mode, the UE  206  can connect only to the CAG cell  204  to access the 5GC  202   c.    
     At step  502 , the UE  206  receives a request from the user for the emergency service. In such a case, the UE  206  disables the CAG only mode. The UE  206  may select any one of the non-CAG cells that are available in the location of the UE  206 , wherein the non-CAG cells can be gNBs or eNBs connecting to the 5GC or the EPC. In an example herein, the UE  206  may select any one of the non-CAG cell/gNBs  202   b  of the 5GS  202   a  that are available in the location of the UE  206 . The UE  206  camps onto the selected non-CAG cell/gNB  202   b  for initiating the emergency service. The UE  206  performs the emergency attach procedure with the AMF  402  of the 5GC  202   c  that is connected to the camped non-CAG cell/gNB  202   b  and establishes the PDU session with the external data network through the 5GC  202   c . The UE  206  thereafter can perform the emergency services over the established PDU session. 
     At step  503 , the UE  206  enters into the idle mode on the release/completion of the initiated emergency service. The UE  206  remains in the idle mode for the pre-defined period of time. On the expiry of the pre-defined time, at step  504 , the UE  206  again enables the CAG only mode by itself or by performing the registration update procedure with the AMF  402  of the 5GC  202   c.    
       FIG. 6  is an example sequence diagram depicting the handling of the emergency service using the non-CAG cells  202   b  in the wireless network  200  that includes the SNPN  204 , according to an embodiment of the disclosure. In an example herein, consider that the wireless network  200  includes the SNPN  204  as the NPN  204 . The SNPN  204  can connect to the 5GS  202   a . The UE  206  can support the SNPN  204  and the PLMN  202 . In such a case, at step  601 , the UE  206  registers with the SNPN  204  and camps onto the SNPN cells/CAG cells for accessing the 5GC  202   a  (i.e., configured to operate in the SNPN access mode (CAG only mode)). 
     At step  602 , the UE  206  receives a request from the user for the emergency service. In such a case, the UE  206  disables the SNPN access mode by disabling an Access Stratum (AS) layer and NAS capability related to SNPN. The UE  206  may select any one of the non-CAG cells that are available in the location of the UE  206 , wherein the non-CAG cells can be gNBs or eNBs connecting to the 5GC or the EPC. In an example herein, consider that the UE  206  may select any one of the non-CAG cell/gNBs  202   b  of the 5GS  202   a  that are available in the location of the UE  206 . The UE  206  camps onto the selected non-CAG cell/gNB  202   b  for initiating the emergency service. The UE  206  performs the emergency attach procedure with the AMF  402  of the 5GC  202   c  that is connected to the camped non-CAG cell/gNB  202   b  and establishes the PDU session with the external data network through the 5GC  202   c . The UE  206  thereafter can perform the emergency services over the established PDU session. 
     At step  603 , the UE  206  enters into the idle mode on the release/completion of the initiated emergency service. The UE  206  remains in the idle mode for the pre-defined period of time. Once the pre-defined period of time has passed, at step  604 , the UE  206  again enables the SNPN access mode. 
       FIG. 7  is a flow diagram  700  depicting a method for handling the emergency services in the wireless network  200  including the NPN  204  and the PLMN  202 , according to an embodiment of the disclosure. 
     At step  702 , the method includes initiating, by the UE  206 , the at least one emergency service while operating in the CAG only mode. In the CAG only mode, the UE  206  access only the at least one CAG cell/NPN  204 . 
     At step  704 , the method includes selecting, by the UE  206 , the non-CAG cell  202   b  from the plurality of CAG cells in the PLMN. The non-CAG cell  202   b  can be a public RAN that provides the normal communication services and the emergency services to the UE  206  by supporting the at least one CAG cell  204 . The UE  206  can perform the initiated at least one emergency service by establishing the PDU session or by establishing the emergency attach procedure with the non-CAG cell  202   b . The various actions in method  700  may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in  FIG. 7  may be omitted. 
       FIGS. 8A and 8B  depict another wireless network/wireless communication system  800  for handling the emergency services while performing periodic registration procedures, according to an embodiment of the disclosure. The wireless network  800  referred herein can be configured for handling emergency services while performing periodic registration procedures by at least one UE. The emergency services can support real-time, high priority total conversation services such as, but not limited to, voice calls, video calls, real-time text messages, IP Multimedia Subsystem (IMS) emergency calls, or the like. Examples of the emergency event can be, but is not limited to, a medical event, a criminal attack, a natural disaster, an accident, an injury, and so on. The periodic registration procedure may be performed to update location information of the at least one UE and mobility registered state with the network  800  for tracking the at least one UE. 
     The wireless network  800  includes at least one PLMN  802  and a plurality of UEs  804 . The PLMN  802  can be configured to provide PLMN services to the UEs  804  in a specific region. The PLMN services include communication services and emergency services. Examples of the communication services can be, but is not limited to, a streaming service (streaming of multimedia data such as audio, video, text and so on), a file download service, a carousel service (a service for combining file download service and streaming service), a television (TV) service, an Internet Protocol (IP) Multimedia Subsystem (IMS) service, a non-3rd Generation Partnership Project (3GPP) service (for example: firewalling or the like), a short messaging service, a Multimedia Messaging Service (MMS), and so on. Examples of the emergency services can be, but not limited to, emergency calls to local Fire/Ambulance/Police stations, IMS calls, text messages, and so on. The PLMN  802  can be operated by a mobile network operator (MNO) and can be identified using a PLMN_identifier (PLMN_ID). Embodiments herein use the terms such as “PLMN”, “cellular network”, “public network”, “3GPP access network”, and so on, interchangeably to refer to a network that provides the emergency services, and the communication services to public use in a given region. 
     The PLMN  802  includes one or more different public cellular networks/RATs  806  such, as, but not limited to, a Long Term Evolution (LTE) network, an advanced LTE network, a New Radio (NR)/5G network, a Narrowband Internet of Things (NB-IoT), a Universal Mobile Telecommunications Service (UMTS), a Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN) system or any other next generation networks. The RATs  806  includes a plurality of RANs  806   a , and at least one CN  806   b . The RAN  806   a  and the CN  806   b  may comprise of one or more processors/Central Processing Units (CPUs), a memory, a storage, a transceiver, and so on, for performing at least one intended function/operation. 
     The RAN  806   a  may comprise of nodes/Base Stations (BSs) such as, but not limited to, evolved nodes (eNBs), New Radio nodes (gNBs), a new radio access network supporting both an eNB, and a gNB, and so on. The RAN  806   a  can connect the at least one UE  804  to the at least one CN  806   b . The RAN  806   a  can be configured to perform radio resource management functions such as, but not limited to, radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to the UE in uplink/downlink (scheduling), and so on. 
     The CN  806   b  referred herein can be at least one of an Evolved Packet Core (EPC), a 5G core (5GC) network, or the like. The CN  806   b  can be connected to the RAN  806   a  and an external data network. Examples of the external data network can be, but not limited to, the Internet, a Packet Data Network (PDN), an Internet Protocol (IP) Multimedia Core Network Subsystem, and so on. The CN  806   b  can be configured to connect the at least one UE  804  to the external data network for the communication services or the emergency services. In an example, as depicted in  FIG. 8B , the PLMN  802  includes a 5G system (5GS)  806  and a LTE network  808 . The 5GS  806  includes a plurality of gNBs/RANs  806   a  connected to at least one 5GC  806   b . The LTE network  808  includes a plurality of eNBs/RANs  806   a  connected to at least one EPC  806   b.    
     The UE(s)  804  can be a user device that is capable of supporting the PLMN  802 . Examples of the UE  804  can be, but is not limited to, a mobile phone, a smartphone, a tablet, a phablet, a personal digital assistant (PDA), a laptop, a computer, a wearable computing device, a vehicle infotainment device, an Internet of Things (IoT) device, a Virtual Reality (VR) device, a Wireless Fidelity (Wi-Fi) router, a USB dongle, a sensor, a robot, an auto-guided vehicle, and so on. The UE  804  can include one or more processors/Central Processing Units (CPUs), a memory, a transceiver, and so on, for performing at least one intended function/operation. In an embodiment, the UE  804  can be configured to operate in a Mobile Initiated Connection Only (MICO) mode by registering with the CN  806   b  of the PLMN  802 . The UE  804  may operate in the MICO mode, when the UE  804  wants to perform only an uplink data transfer. Thus, in the MICO mode, the UE  804  can only send data (for example: text messages, media (for example; audio, video, images, and so on), sensor data, and so on)) to the at least one CN  806   b  of the PLMN  802  without receiving any downlink data from the CN  806   b . Thus, in the MICO mode, the CN  806   b  does not perform paging for the UE  804 . 
     In an embodiment, the UE  804  has to perform a registration management procedure and a signaling/connection management procedure in order to register location information and ensure that information about where the UE  804  is currently located is continuously up-to-date and correct in the location registers of the PLMN  802 . Thus, the CN  806   b  can track the UE  804  continuously. In an embodiment, the UE  804  performs the registration and connection management procedures according to 3GPP 23.501 subclause 5.3.7. 
     The UE  804  performs the registration management procedure to register/de-register with the at least one CN  806   b  of the PLMN  802  and establish UE context in the CN  806   b . The UE  804  performs a registration procedure to register with the CN  806   b  to receive the services that requires registration. On registering with the CN  806   b , if applicable, the UE can update its registration to the CN  806   b  to periodically maintain reach ability/location (i.e., periodic registration update), or update its capability or re-negotiate protocol parameters upon movement (mobility registration update). Further, the UE  804 , and the CN  806   b  uses two states; a de-registered state (RM-DEREGISTERED/5GMM-DEREGISTERED state) and a registered state (RM-REGISTERED/5GMM-REGISTERED state); that reflect a registration status of the UE  804  in the PLMN  802 . In the de-registered state, the UE  804  is not registered with the CN  806   b  of the PLMN  802 . The UE context in CN  806   b  holds no valid location or routing information for the UE  804 , so the UE  804  is not reachable by the CN  806   b  of the PLMN  802 . However, some parts of the context of the UE may still be stored in the UE  804  and the CN  806   b  to avoid performing an authentication procedure during every registration procedure. In the registered state, the UE  804  can be registered with the CN  806   b  and the UE  804  can receive the services that require registration with the CN  806   b.    
     The UE  804  performs the connection management procedure for establishing and releasing a NAS signaling connection between the UE  804  and the CN  806   b  of the PLMN  802 . The NAS signaling connection enables NAS signaling exchange between the UE  804  and the CN  806   b . In the connection management, two connection management states (an idle state (CM-IDLE/5GMM-IDLE state) state and a connected state (CM-CONNECTED/5GMM-CONNECTED state)) can be used to reflect the NAS signaling connection of the UE  804  with the CN  806   b . In the idle state, the UE  804  may be in the registered state without having the NAS signaling connection established with the CN  806   b . In the idle state, the UE  804  performs at least one of cell section, cell re-selection, PLMN selection, and so on. In the connected state, the UE  804  establishes the NAS signaling with the CN  806   b.    
     The UE  804  performs a periodic registration procedure with the CN  806   b  of the PLMN  802  during the registration state to initially update its reach ability or the location information with the CN  806   b . The UE  804  may perform the periodic registration procedure, according to the 3GPP specification. In an embodiment, the UE  804  can operate in the MICO mode to perform the periodic registration procedure during the registration state. In response to the periodic registration procedure performed during the registration state, the CN  806   b  allocates a periodic registration timer value for the UE  804  and sends the allocated periodic registration timer value with a strict indication (“Strictly Periodic Timer Registration Indication”) to the UE  804 . The periodic registration timer value may indicate time/duration within which, the UE  804  has to perform the periodic registration procedure again to periodically update its reach ability or the location to the CN  806   b . In an embodiment, the CN  806   b  may allocate the periodic registration timer value to the UE  804  based on factors such as, but not limited to, local policies, subscription information, information that has been provided by the UE  804 , and so on. During the received periodic registration timer value, the UE  804  can enter into the connected state for the data transmission and into the idle state on completion of the data transmission for a number of times. 
     In order to track the periodic registration timer value, the UE  804  maintains a periodic tracking area update (PTAU) timer (for example; a T3512 timer). In an embodiment, on receiving the periodic registration timer value with the “Strictly Periodic Timer Registration Indication” from the CN  806   b , the UE  804  operates the PTAU timer in a strictly periodic registration mode. In the strictly periodic registration mode, the UE  804  applies the received periodic registration timer value to the PTAU timer with the strict indication (“Strictly Periodic Timer Registration Indication”). Thus, the PTAU timer may behave as a periodic registration timer with “Strictly Periodic Timer Registration Indication”. While operating in the strictly periodic registration mode, the PTAU timer does not terminate/stop, when the UE  804  moves from the idle state/mode to the connected state/mode. While operating in the strictly periodic registration mode, the PTAU timer does not restart, when the UE  804  moves from the connected mode/state to the idle state/mode. Thus, in the strictly periodic registration mode, the PTAU timer starts operating with a value of 0 and expires only when the PTAU timer reaches the received periodic registration timer value, irrespective of the movement of the UE  804  from the idle state to the connected state or vice-versa. The UE  804  strictly performs the periodic registration procedure with the CN  806   b  of the PLMN  802  only on the expiry of the PTAU timer and irrespective of the number of times that the UE had been to the connected state or the idle state during the received periodic registration timer value. 
     Further, the UE  804  may initiate the emergency service during the received periodic registration timer value or while the PTAU timer is operating. In an embodiment, the UE  804  switches the behavior of the PTAU timer from the strictly periodic registration mode to a normal periodic registration mode, on initiating the emergency service. In the normal periodic registration mode, the UE  804  may apply the periodic registration timer value to the timer without the strict indication. In the normal periodic registration mode, the PTAU timer may terminate, when the UE  804  moves from the idle state to the connected state. In the normal periodic registration mode, the PTAU timer may reset and restarted, when the UE  804  moves from the connected state to the idle state. The UE  804  performs the initiated at least one emergency service on the behavior of the timer being switched. 
     On initiating the emergency service, the UE  804  performs an emergency attach procedure with the CN  806   b  and establishes an emergency PDU session with the external data network through the CN  806   b  (according to 3GPP specification). In an embodiment, on establishing the emergency PDU session, the UE  804  stops operating/disables the PTAU timer and switches the behavior of the PTAU timer from the periodic registration timer value with the “Strictly Periodic Timer Registration Indication” into a normal periodic registration timer/pre-release 16 behavior. In an embodiment, switching the behavior of the PTAU timer on initiating the emergency service includes applying the received periodic registration timer value to the PTAU timer without “Strictly Periodic Timer Registration Indication”. 
     In an embodiment, if the UE  804  initiates the emergency service while operating in the MICO mode, the UE  804  disables the MICO mode, and the CN  806   b  disables the registered MICO mode of the UE  804 . Further, the UE  804  performs an emergency attach procedure with the CN  806   b  and establishes an emergency PDU session with the external data network through the CN  806   b . Thereafter, the UE  804  stops operating the PTAU timer and the CN  806   b  stops monitoring the PTAU timer of the UE  804 . The UE  804  then switches the behavior of the PTAU timer from the periodic registration timer value with the “Strictly Periodic Timer Registration Indication” into the normal periodic registration timer/pre-release 16 behavior. Thus, when the UE  804  and the CN  806   b  disables the MICO mode on initiating the emergency service, the UE  804  and the CN  806   b  may behave as if there was no ‘Strictly Periodic Registration Timer Indication’ indication has been provided to the UE  804  in the last registration procedure. 
     Once the PTAU timer stops operating and the behavior of the PATU timer is switched, the UE  804  performs the emergency service over the established emergency PDU session (according to the 3GPP specification). On completion or release of the emergency service, the UE  804  enters into the idle state, starts the PTAU timer to operate and remains in the idle state till the expiry of the PTAU timer. In an embodiment, as the behavior of the PTAU timer is switched, the PTAU timer starts operating from a value of zero and expires once the PTAU timer reaches the received periodic registration timer value. Thus, duration of the idle mode may be increased, which further provides a sufficient time/duration for the UE  804  to receive an emergency call back from the CN  806   b  of the PLMN  802 . 
     On the expiry of the PATU timer, the UE  804  performs the periodic registration procedure with the CN  806   b  to update the location information and receives the periodic registration timer value. The UE  804  may keep track of the periodic registration timer value by applying the received periodic registration timer value with the “Strictly Periodic Timer Registration Indication” and initiating the timer to operate. Thus, the UE  804  may continue to operate the PTAU as the periodic registration timer with the “Strictly Periodic Timer Registration Indication” till the initiation of the emergency service and to switch the behavior of the PTAU timer to the normal periodic registration timer/pre-release 16 behavior on the initiation of the emergency service. Thus, avoiding possible issues to the emergency services. 
       FIGS. 8A and 8B  depict exemplary units/components of the wireless network  800 , but it is to be understood that other embodiments are not limited thereon. In other embodiments, the wireless network  800  may include less or a greater number of units. Further, the labels or names of the units are used only for illustrative purpose and does not limit the scope of the embodiments herein. One or more units can be combined together to perform same or substantially similar function in the wireless network  800 . 
       FIG. 9A  depicts the wireless network  800  handling the emergency services by switching the behavior of the PTAU timer to the normal periodic registration timer, wherein the wireless network  800  includes a 5G system (5GS), according to an embodiment of the disclosure. Embodiments herein are further explained considering the PLMN  802  of the wireless network  800  including a 5G system (5GS)  806 , as an example. As depicted in  FIG. 9A , the 5GS  806  includes at least one gNB  806   a , and a 5GC  806   b . The 5GC network  806   b  may include an AMF  902  configured to support functions such as, but not limited to, termination of NAS signaling, NAS ciphering and integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management, and so on. The 5GC network  806   b  also includes an authentication server function (AUSF), a unified data management (UDM)/an authentication credential Repository (ARPF), a session management function (SMF), a user plane functionality (UPF), a policy control function, an application function, a network exposure function (NEF), a NF repository function (NRF), a network slice selection function (NSSF), and so on (not shown). 
     The UE  804  can be configured to connect to the 5GC network  806   b  through the gNB  806   a . The UE  804  can also be configured to perform the registration management procedure with the AMF  902  of the CN  806   b  to register its reach ability/location information, mobility registered state, and so on. 
     As depicted in  FIG. 9B , the UE  804  includes a memory  904 , a communication interface  906 , a display  908 , and a periodic registration controller  910 . The UE  804  can also include at least one transceiver, processing circuitry, a storage unit, a input/output (I/O) module, and so on (not shown). 
     The memory  904  can store at least one of the received periodic registration value, the PLMN_IDs, and so on. Examples of the memory  904  can be, but not limited to, NAND, embedded Multi Media Card (eMMC), Secure Digital (SD) cards, Universal Serial Bus (USB), Serial Advanced Technology Attachment (SATA), solid-state drive (SSD), and so on. Further, the memory  904  may include one or more computer-readable storage media. The memory  904  may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory  904  may, in some examples, be considered a non-transitory storage medium. The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term “non-transitory” should not be interpreted to mean that the memory  904  is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache). 
     The communication unit  906  can be configured to enable the UE  804  to connect with at least one of the at least one RAN  806   a  of the PLMN  802  over an interface. Examples of the interface can be at least one of a wired interface, a wireless interface (for example: an air interface, an Nu interface, or the like), a wireless fronthaul interface, a wired or wireless backhaul interface, or any structure supporting communications over a wired or wireless connection. The display  908  can be configured to enable the user to interact with the UE  804 . The display  908  can also be configured to receive a request from the user for initiating the emergency services. 
     The periodic registration controller  910  can be at least one of a single processer, a plurality of processors, multiple homogeneous or heterogeneous cores, multiple Central Processing Units (CPUs) of different kinds, microcontrollers, special media, and other accelerators. The periodic registration controller  910  can be configured to perform the registration management procedure and the connection management procedure with the AMF  902  of the 5GC  806   b.    
     The periodic registration controller  910  performs the registration management procedure to register/de-register with the AMF  902  of the CN  806   b  and to establish the UE context in AMF  902  of the CN  806   b . The periodic registration controller  910  maintains a registered state or a registration attempting state or a registration update needed state (5GMM REGISTERED state or 5GMMREGISTERED.ATTEMPTING-REGISTRATION-UPDATE, or 5GMM-REGISTERED.UPDATE-NEEDED state) and a 5GMM-DEREGISTERED state for reflecting the registration status of the UE  804 . In the 5GMM-DEREGISTERED state, the periodic registration controller  910  may not be registered with the AMF  902  of the CN  806   b . In the 5GMM-REGISTERED state, the periodic registration controller  910  may perform the periodic registration procedure with the AMF  902  of the CN  806   b  to periodically update the location information/reach ability, mobility registration update, and so on with the AMF  902 . The periodic registration controller  910  performs the connection management procedure for establishing and releasing the NAS signaling connection between the UE  804  and the AMF  902 . The NAS signaling connection enables NAS signaling exchange between the UE  804  and the CN  806   b . In the connection management, two connection management states a CM-5GMM-IDLE state and a 5GMM-CONNECTED state can be used to reflect the NAS signaling connection of the UE  804  with the AMF  902 . In the CM-5GMM-IDLE state, the UE  804  may be in the registered state without having the NAS signaling connection established with the AMF  902 . In the CM-5GMM-IDLE state, the periodic registration controller  910  of the UE  804  performs at least one of cell section, cell re-selection, PLMN selection, and so on. In the connected state, the periodic registration controller  910  of the UE  804  establishes the NAS signaling with the AMF  902 . 
     The periodic registration controller  910  can be configured to perform the periodic registration procedure with the AMF  902  of the CN  806   b  and receives the periodic registration timer value from the AMF  902 . In an embodiment, the periodic registration controller  910  can enable the UE  804  to operate in the MICO mode to perform the registration procedure. 
     The periodic registration controller  910  can be further configured to maintain the PTAU timer for tracking the received periodic registration timer value. The periodic registration controller  910  enables the PTAU timer to operate/behave as the periodic registration timer with the “Strictly Periodic Registration Timer Indication” by applying the received periodic registration timer value and the “Strictly Periodic Registration Timer Indication” to the PTAU timer. The PTAU timer may start from the value of 0 and expires on reaching the received periodic registration timer value. When the PTAU timer expires, the periodic registration controller  910  enables the UE  804  to perform the periodic registration procedure with the AMF  902  by entering into the 5GMM_REGISTERED state for updating the location information/mobility registration update with the AMF  902 . In an embodiment, the periodic registration controller  910  does not restart the PTAU timer if the UE  804  enters into the 5GMM-CONNECTED state for the data transmission or into the 5GMM-IDLE state on completion of the data transmission. 
     The periodic registration controller  910  can be further configured to switch the behavior of the PTAU timer from the periodic registration timer with the “Strictly Periodic Registration Timer Indication” into the normal periodic registration timer value when the UE  804  initiates the emergency service on receiving a request from the user for the emergency service. In an embodiment, the UE  804  may initiate the emergency service when the UE  804  is in the 5GMM-CONNECTED state. In an embodiment, the UE  804  may initiate the emergency service when the UE  804  is operating in the MICO mode. 
     When the emergency service is initiated in the 5GMM-CONNECTED state of the UE  804 , the periodic registration controller  910  enables the UE  804  to perform the emergency attach procedure with the AMF  902  for establishing the emergency PDU session. During the emergency attach procedure, the periodic registration controller  910  of the UE  804  sends an emergency registration request to the AMF  902  through the associated RAN/gNB  806   a  by enabling the UE  804  to enter into an emergency registered state. On receiving the emergency registration request from the periodic registration controller  910  of the UE  804 , the AMF  902  establishes the emergency PDU session between the UE  804  and the external data network without authenticating the UE  804 . Once the emergency PDU session has been established for the UE  804 , the periodic registration controller  910  stops operating the PTAU timer. The periodic registration controller  910  then applies the received periodic registration timer value without the “Strictly Periodic Registration Timer Indication” to the PTAU timer. Thus, the PTAU timer may switch its behavior from the periodic registration timer with the “Strictly Periodic Registration Timer Indication” into the normal periodic registration timer value. 
     When the emergency service is initiated in the MICO mode of the UE  804 , the periodic registration controller  910  enables the UE  804  to disable the MICO mode. The periodic registration controller  910  also sends a disable request to the AMF  902  for disabling the registered MICO mode for the UE  804 . On disabling the MICO mode, the periodic registration controller  910  performs the emergency attach procedure with the AMF  902  for establishing the emergency PDU session between the UE  804  and the external data network. Once the emergency PDU session has been established for the UE  804 , the periodic registration controller  910  stops operating the PTAU timer, and the AMF  902  stops monitoring the periodic registration timer value allocated for the UE  804 . Further, the periodic registration controller  910  of the UE  804  and the AMF  902  behaves as if no “Strictly Periodic Registration Timer Indication” was given to the UE  804  in the last registration attempt. The periodic registration controller  910  then switches the behavior of the PTAU timer by applying only the received periodic registration timer value (i.e. without the “Strictly Periodic Registration Timer Indication”) to the PTAU timer. Thus, the PTAU timer may act as the normal periodic registration timer/pre-release 16 behavior. 
     On switching the behavior of the PTAU timer to the normal periodic registration timer, the periodic registration controller  910  enables the UE  804  to perform the emergency services over the established emergency PDU session. Once the emergency service is completed, the periodic registration controller  910  enables the UE  804  to enter into the 5GMM-IDLE state and starts the PTAU timer. The periodic registration controller  910  allows the UE  804  to remain in the 5GMM-IDLE state till the expiry of the PTAU timer. When the PTAU timer expires, the periodic registration controller  910  enables the UE  804  to detach locally from the AMF  902  of the CN  806   b  (according to 3GPP TS 24.501 subclause 5.3.7) due to its emergency registered state. The periodic registration controller  910  then performs the periodic registration procedure with the AMF  902  by entering into the 5GMM-REGISTERED state. 
       FIG. 10  is an example sequence diagram depicting the handling of the emergency service by enabling the PTAU timer supporting the “Strictly Periodic Registration Timer Indication” to act as the normal periodic registration timer, according to an embodiment of the disclosure. 
     At step  1001 , the UE  804  performs the periodic registration procedure with the CN  806   b  of the PLMN  802  during the registered state and receives the periodic registration timer value from the CN  806   b . In an example herein, consider that the UE  804  may operate in the MICO mode, and the periodic registration timer value may be 12 minutes (mins). At step  1002 , the UE  804  initiates the PTAU timer by applying the received periodic registration timer value with the “Strictly Periodic Registration Timer Indication”. At step  1003 , the UE  804  then enters into the connected state. After 4 mins of entering into the connected state, at step  1004 , the UE  804  enters into the idle mode. After 2 mins of entering into the idle state, at step  1005 , the UE  804  starts the data transmission to the CN  806   b  by entering into the connected state and enters into the idle state on completion of the data transmission. In an embodiment, the UE  804  does not re-start the PTAU timer, as the PTAU timer behaves as the periodic registration timer with the “Strictly Periodic Registration Timer Indication”. 
     After 3 mins of entering into the idle mode, at step  1006 , the UE  804  may receive a request from the user to initiate an emergency call. The UE  804  initiates the emergency call by disabling the MICO mode. The UE  804  further performs the emergency attach procedure with the CN  806   b  by entering into the emergency registered state to establish the emergency PDU session with the external data network. Once the emergency PDU session is established, the UE  804  stops the PTAU timer, and the CN  806   b  stops monitoring the periodic registration timer value sent to the UE  804 . The UE  804  further switches the behavior of the PTAU timer from the periodic registration timer with the “Strictly Periodic Registration Timer Indication” to the periodic registration timer value. 
     On switching the behavior of the PTAU timer, the UE  804  performs the emergency call over the established PDU session. Once the emergency call is completed, at step  1007 , the UE  804  enters into the idle mode. When the UE  804  enters into the idle state, the UE  804  starts the PTAU timer. As the behavior of the PTAU timer is switched, the PTAU timer starts from a value of 0 and expires on the timer reaching 12 mins. The UE  804  further remains in the idle state till the expiry of the PTAU timer, which provides a sufficient time (for example: 12 mins) for the UE  804  to receive the emergency call back from the CN  806   b.    
     When the PTAU timer expires, at step  1008 , the UE  804  locally detaches from the CN  806   b , since the UE  804  has attached with the CN  806   b  for performing the emergency attach procedure. The UE  804  further performs the periodic registration procedure with the CN  806   b  by entering into the registration state. 
       FIG. 11  is a flow diagram  1100  depicting a method for handling the emergency services by switching the behavior of the timer, according to an embodiment of the disclosure. 
     At step  1102 , the method includes receiving, by the UE  804 , the periodic registration timer value with the “Strictly Periodic Registration Timer Indication” indication from the CN  806   b.    
     At step  1104 , the method includes operating, by the UE  804 , the timer in the strictly periodic registration mode in response to the received periodic registration timer value with the “Strictly Periodic Registration Timer Indication” indication. 
     At step  1106 , the method includes initiating, by the UE  804 , the at least one emergency service while the timer is operating. At step  1108 , the method includes switching, by the UE  804 , the behavior of the timer from the strictly periodic registration mode to a normal periodic registration mode on initiating the at least one emergency service. 
     At step  1110 , the method includes performing, by the UE  804 , the initiated at least one emergency service on the behavior of the timer being switched. The various actions in method  1100  may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in  FIG. 11  may be omitted. 
     Embodiments herein further enable the UE  804  connected to at least one of the CN  806   b  of the PLMN  802  to handle priority services. Examples of the priority services can be, but not limited to, Mission Critical Services (MCS), Vehicle-to-everything (V2X) communication, Mobile Positioning System (MPS) network related services, Ultra-reliable low-latency communication (URLLC) services, and so on. 
       FIGS. 12A, 12B, and 12C  are flow diagrams depicting the handling of the at least one priority service, according to an embodiment of the disclosure. The UE  804  executes  1201   a - 1203   a ,  1201   b - 1203   b ,  1201   c - 1203   c , when the UE receives data or signaling related to at least one of the Mission Critical Service, the V2X communication, the MPS network related services, the URLLC services, and so on. 
     As depicted in  FIG. 12A , at step  1201   a , the UE  804  may be in a registration attempting state (for example: 5GMM.DEREGISTERED.ATTEMPTING-REGISTRATION) state and the UE  804  executes/operates a timer (for example; at least one of a T3510 timer, a T3511 timer, a T3502 timer, or the like). At step  1202   a , the UE  804  receives a request from an upper layer for the at least one priority service to establish signaling (for example: MCS signaling, V2 signaling, URLCC signaling, or the like) or user data. In such a case, at step  1203   a , the UE  804  stops operating the timer and sends a registration request with an initial registration to the CN  806   b.    
     As depicted in  FIG. 12B , at step  1201   b , the UE  804  may be in a registration attempting update state (for example: 5GMMREGISTERED.ATTEMPTING-REGISTRATION UPDATE state and the UE  804  operates the timer (for example; at least one of the T3510 timer, the T3511 timer, the T3502 timer, or the like). At step  1202   b , the UE  804  the UE  804  receives a request from an upper layer for the at least one priority service to establish signaling or user data. In such a case, at step  1203   b , the UE  804  stops operating the timer and sends the registration request with the initial registration to the CN  806   b.    
     As depicted in  FIG. 12C , at step  1201   c , the UE  804  is in a register with an idle state (for example: 5GMMREGISTERED with 5GMM IDLE state) and the UE  804  executes/operates a T3525 timer. At step  1202   c , the UE  804  receives a request from an upper layer for the at least one priority service to establish signaling or user data. In such a case, at step  1203   c , the UE  804  transmits a service request message related to the at least one priority service to the CN  806   b.    
     In an embodiment, the UE  804  may operate a back off timer, T3346. In such a case, if the UE receives a request from the normal services, the UE  804  does not transmit a NAS signaling message (for example: a registration message, a service message, or the like) related to the normal service to the CN  806   b . In an embodiment, the UE  804  continues operating the back off timer and does not send the NAS signaling message to the CN  806   b . In an embodiment, the UE  804  stops operating the back off timer and the NAS signaling to resume the allowed normal service. 
     In an embodiment, if the UE  804  receives the request for the at least one priority service to establish the signaling or the user while the back off timer is operating, the UE  804  transmits a NAS message (for example, a registration request or service request message) related to the at least one priority service to the CN  806   b.    
     The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the elements. The elements shown in  FIGS. 2A-12C  can be at least one of a hardware device, or a combination of hardware device and software module. 
       FIG. 13  schematically illustrates the base station according to an embodiment of the disclosure. 
     Referring to the  FIG. 13 , the Base station  1300  may include a processor  1310 , a transceiver  1320  and a memory  1330 . However, all of the illustrated components are not essential. The Base station  1300  may be implemented by more or less components than those illustrated in  FIG. 13 . In addition, the processor  1310  and the transceiver  1320  and the memory  1330  may be implemented as a single chip according to another embodiment. 
     The aforementioned components will now be described in detail. 
     The processor  1310  may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the Base station  1300  may be implemented by the processor  1310 . 
     The transceiver  1320  may include a RF transmitter for up-converting and amplifying a transmitted signal, and a RF receiver for down-converting a frequency of a received signal. However, according to another embodiment, the transceiver  1320  may be implemented by more or less components than those illustrated in components. 
     The transceiver  1320  may be connected to the processor  1310  and transmit and/or receive a signal. The signal may include control information and data. In addition, the transceiver  1320  may receive the signal through a wireless channel and output the signal to the processor  1310 . The transceiver  1320  may transmit a signal output from the processor  1310  through the wireless channel. 
     The memory  1330  may store the control information or the data included in a signal obtained by the Base station  1300 . The memory  1330  may be connected to the processor  1310  and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory  1330  may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices. 
     In an embodiment, the transceiver  1320  may transmit, to a User Equipment (UE), at least one signal for selecting a plurality of non-CAG cells available in a location of the UE, connect to the UE based on the at least one signal and provide at least one emergency service to the UE. 
       FIG. 14  schematically illustrates a user equipment (UE) according to an embodiment of the disclosure. 
     Referring to the  FIG. 14 , the UE  1400  may include a processor  1410 , a transceiver  1420  and a memory  1430 . However, all of the illustrated components are not essential. The UE  1400  may be implemented by more or less components than those illustrated in  FIG. 14 . In addition, the processor  1410  and the transceiver  1420  and the memory  1430  may be implemented as a single chip according to another embodiment. 
     The aforementioned components will now be described in detail. 
     The processor  1410  may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the UE  1400  may be implemented by the processor  1410 . 
     The transceiver  1420  may include a RF transmitter for up-converting and amplifying a transmitted signal, and a RF receiver for down-converting a frequency of a received signal. However, according to another embodiment, the transceiver  1420  may be implemented by more or less components than those illustrated in components. 
     The transceiver  1420  may be connected to the processor  1410  and transmit and/or receive a signal. The signal may include control information and data. In addition, the transceiver  1420  may receive the signal through a wireless channel and output the signal to the processor  1410 . The transceiver  1420  may transmit a signal output from the processor  1410  through the wireless channel. 
     The memory  1430  may store the control information or the data included in a signal obtained by the UE  1400 . The memory  1430  may be connected to the processor  1410  and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory  1430  may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices. 
     The embodiments disclosed herein describe methods and systems for handling emergency services in a wireless network. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in a preferred embodiment through or together with a software program written in e.g. Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device may also include means which could be e.g. hardware means like e.g. an ASIC, or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g. using a plurality of CPUs. 
     Although the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.