Abstract:
A method for operating a terminal using reduced power consumption in a mobile communication system is provided. The method includes receiving a signal, determining whether the received signal corresponds to a Session Initiation Protocol (SIP) update request message, if the received signal corresponds to an SIP update request message, sending the SIP update request message to an SIP processor in a communication processor; and handling the SIP update request message by the SIP processor.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a mobile communication system. More particularly, the present invention relates to a method and apparatus for consuming low power by a terminal in a mobile communication system. 
         [0003]    2. Description of the Related Art 
         [0004]    Mobile communication systems have been developed to provide voice services while ensuring the user&#39;s activity. However, the mobile communication systems have gradually expanded their respective services from voice services to include data services. At present, the mobile communication systems have evolved to provide high-speed data services. However, mobile communication systems according to the related art suffer from a lack of resources. More advanced wireless communication systems are required to meet the increasing users&#39; demand for high-speed services. 
         [0005]    To meet these needs, standardization for a Long Term Evolution (LTE) communication system, one of the next-generation wireless communication systems under development, is underway in 3rd Generation Partnership Project (3GPP). Because the LTE system basically supports only the packet services, the LTE standard has proposed a Circuit Switched FallBack (CSFB) service, in which in order to provide a voice call to a user, upon receiving an incoming voice call, a terminal camping on an LTE network drops its connection to the LTE network, and accesses the legacy 3rd Generation (3G) network (or Circuit Switched (CS) network) to provide a voice call service. In addition to CSFB, the LTE standard has proposed a Voice over LTE (VoLTE) service as technology for supporting a voice call service in the LTE network. According to the VoLTE service, a terminal converts the user&#39;s voice into packet data and transmits the packet data across the LTE network. 
         [0006]    As the LTE system applies the voice call service that uses the legacy 3G CS network, to the Packet Switched (PS) data network, a protocol for voice call control between a terminal and the network is required. To this end, a Session Initiation Protocol (SIP) protocol is used. The SIP protocol provides multiple functions, such as a message delivery function of sending a call to the other party when a user makes a call, a function of receiving and responding to a call message upon receiving the call message from the other party, a function of accepting, rejecting or dropping the call depending on the user&#39;s input, and a function of determining whether the terminal is normally connected to the network. 
         [0007]      FIG. 1  illustrates a structure of a terminal according to the related art. 
         [0008]    Referring to  FIG. 1 , the terminal includes an Application Processor (AP)  100 , a Session Inter-Process Communication (SIPC)  120 , and a Communication Processor (CP)  130 . The Session Inter-Process Communication (SIPC)  120  operates for interworking between the AP  100  and the CP  130 . 
         [0009]    In the terminal, the SIP protocol is implemented in the AP  100 . 
         [0010]    It is assumed that an SIP message and/or a voice packet are received at the terminal from a network. 
         [0011]    Upon receiving a voice packet from the network, a Packet Data Convergence Protocol (PDCP) filter  134  in the CP  130  of the terminal transfers the voice packet to a voice engine  132  via a Transfer Control Protocol/Internet Protocol (TCP/IP)  136  in the CP  130 , and the voice engine  132  processes the voice packet, allowing the user to hear the voice. 
         [0012]    Upon receiving an SIP message from the network, the PDCP filter  134  in the CP  130  sends the SIP message to an SIP stack  115  in the AP  100 , so that an appropriate operation is performed for each message. For example, upon receiving the SIP message from the network, the PDCP filter  134  in the CP  130  may send the SIP message to the SIP stack  115  in the AP  100  by way of the TCP/IP  105  in the AP  100 . The AP  100  may include an IMS library  110  comprising the SIP stack  115 . 
         [0013]      FIG. 2  is a flowchart illustrating an operation of a terminal according to the related art. 
         [0014]    Referring to  FIG. 2 , in step  201 , the PDCP filter  134  of the CP  130  included in the terminal receives an SIP message in a situation in which there is no user input. In step  203 , the PDCP filter  134  sends the received SIP message to the SIP stack  115  in the AP  100 , which is responsible for processing an SIP protocol, even in the situation in which there is no user input. In step  205 , the SIP stack  115  in the AP  100  handles the received SIP message. 
         [0015]    Because the terminal attempts to ensure the maximum performance and run time within the terminal limitations (e.g., limited size, processing power, and the like), reduction of the power consumption of the terminal is very important. However, because the SIP stack  115  used to control VoLTE voice calls exists in the AP  100 , the AP  100  is responsible for generating an SIP message and handling a received SIP message. When the user takes an action of making (sending) or receiving a voice call, the AP  100  is enabled in order to activate a User Interface (UI) of the terminal. Therefore, the terminal does not need to additionally enable the AP  100  when the terminal needs to handle an SIP message. 
         [0016]    However, when there is a need to handle an SIP message in a situation in which there is no user input, the terminal should enable the AP  100  in order to handle the SIP message, thereby causing the terminal to consume relatively more power. 
         [0017]    Therefore, a need exists for a method and apparatus for consuming low power by a terminal, in which when there is a need to process an Session Initiation Protocol (SIP) protocol in a situation in which there is no user input. 
         [0018]    The above information is presented as background information only to assist with an understanding of the present 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 present invention. 
       SUMMARY OF THE INVENTION 
       [0019]    Aspects of the present invention 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 present invention is to provide a method and apparatus for consuming low power by a terminal, in which when there is a need to process an Session Initiation Protocol (SIP) protocol in a situation in which there is no user input, the SIP protocol is processed not in an Application Processor (AP), but in a Communication Processor (CP). 
         [0020]    Another aspect of the present invention is to provide a method and apparatus for consuming low power by a terminal, in which an AP is enabled only in a situation in which there is a user input (e.g., only when the user takes an action of making or receiving a voice call). 
         [0021]    In accordance with an aspect of the present invention, a method for operating a terminal using reduced power consumption in a mobile communication system is provided. The method includes receiving a signal, determining whether the received signal corresponds to a SIP update request message, if the received signal corresponds to an SIP update request message, sending the SIP update request message to an SIP processor in a communication processor, and handling the SIP update request message by the SIP processor. 
         [0022]    In accordance with another aspect of the present invention, an apparatus for operating a terminal using reduced power consumption in a mobile communication system is provided. The apparatus includes a receiver for receiving a signal, a filter for determining whether the received signal corresponds to an SIP update request message, and if the received signal corresponds to an SIP update request message, sending the SIP update request message to an SIP processor in a communication processor, and the SIP processor for handling the SIP update request message. 
         [0023]    Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
           [0025]      FIG. 1  illustrates a structure of a common terminal according to the related art; 
           [0026]      FIG. 2  is a flowchart illustrating an operation of a common terminal according to the related art; 
           [0027]      FIG. 3  illustrates a structure of a terminal according to an exemplary embodiment of the present invention; and 
           [0028]      FIG. 4  is a flowchart illustrating an operation of a terminal according to an exemplary embodiment of the present invention. 
       
    
    
       [0029]    Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0030]    The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
         [0031]    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 invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
         [0032]    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. 
         [0033]    The term ‘terminal’ as used herein may refer to a phone that a user can carry with him or her, and on which a voice service is possible over the packet network. The terminal may include, for example, a smart phone, a cellular phone, a tablet computer, and the like, and can access the network using, for example, Wi-Fi communications, 3rd Generation (3G) communications, Long Term Evolution (LTE) communications, and the like. 
         [0034]    In accordance with an exemplary embodiment of the present invention, while processing a VoLTE call, a terminal prevents, if possible, an AP from waking up (e.g., transitioning to an active state) to handle a message (e.g., an SIP update request message) which is received from the network and used to determine whether the terminal normally accesses the network. As a result, the power consumption of the terminal may be reduced. 
         [0035]      FIG. 3  illustrates a structure of a terminal according to an exemplary embodiment of the present invention. 
         [0036]    Referring to  FIG. 3 , the terminal includes an Application Processor (AP)  300 , a Session Inter-Process Communication (SIPC)  320  and a Communication Processor (CP)  330 . 
         [0037]    The AP  300  includes an IP Multimedia Core Network Subsystem (IMS) stack  315  in an IMS library  310 . The AP  300  may also include a Transfer Control Protocol/Internet Protocol (TCP/IP)  305 . In accordance with an exemplary embodiment of the present invention, the IMS stack  315  does not handle SIP update messages. 
         [0038]    The IMS stack  315  is in charge of signaling related to network elements, and bearer setup. The IMS stack  315  may exchange multimedia-type content such as photos, video clips, sound clips, and the like with the network using session-based messages, because the IMS stack  315  processes various types of packet data services based on the IP transport protocol. 
         [0039]    In addition, during initial Voice over LTE (VoLTE) call setup, the IMS stack  315  in the AP  300  transfers a parameter for handling an SIP update request message to an SIP processor  338  in the CP  330  by session refresh Inter Process Communication (IPC). The parameter for handling an SIP update request message may include ‘Timer Value’, ‘IP Address Info.’, ‘Destination Port Info.’ and the like, which are defined in Table 1 below. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Field 
                 Length (bytes) 
                 Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 SUB_CMD 
                 1 
                 Sub-command code (0x07) 
               
               
                 CMD_TYPE 
                 1 
                 EXECUTE (0x01) 
               
               
                 OPERATION 
                 1 
                 0x01: START 
               
               
                   
                   
                 0x02: STOP 
               
               
                   
                   
                 0x03: INIT 
               
               
                 SESSION_ID 
                 4 
                 Session ID 
               
               
                 REFRESHER 
                 1 
                 0x01: UE 
               
               
                   
                   
                 0x02: Network 
               
               
                 RERESH_TIMER_E 
                 2 
                 Session Refresh Time for Timer E (sec) 
               
               
                 REFRESH_TIMER_F 
                 2 
                 Session Refresh Time for Timer F (sec) 
               
               
                 REFRESH_TIMER_K 
                 2 
                 Session Refresh Time for Timer K (sec) 
               
               
                 REFRESH_TIMER_J 
                 2 
                 Session Refresh Time for Timer J (sec) 
               
               
                 REFRESH_TIMER_VAL 
                 2 
                 Session Refresh timer val 
               
               
                 REMOTE_IP_TYPE 
                 1 
                 0x1: IP v4 
               
               
                   
                   
                 0x2: IP v6 
               
               
                 REMOTE_IP 
                 16 
                 Specifies the IP address to be transmitted. 
               
               
                   
                   
                 The address must be given in the format 
               
               
                   
                   
                 wxyz, where wxyz are all integers between 0 
               
               
                   
                   
                 and 255. 
               
               
                 REMOTE_PORT 
                 2 
                 Destination Port Number 
               
               
                   
                   
                 (Valid integer numbers must be in the range 
               
               
                   
                   
                 1024 to 65535) 
               
               
                 IMS_BUFFER_LEN 
                 4 
                 Length of UPDATE SIP msg 
               
               
                 IMS_BUFFER 
                 IMS_BUFFER_LEN 
                 UPDATE SIP MSG (1000 bytes max) 
               
               
                   
               
             
          
         
       
     
         [0040]    The SIPC  320  is a protocol for handling message exchange between the AP  300  and the CP  330 . The CP  330  may also include an SIPC that is responsible for the communication (or message exchange). 
         [0041]    Data exchanged between the AP  300  and the CP  330  may include Circuit Switched Video Telephony (CS VT), Packet Switched Video Telephony (PS VT), Pulse Code Modulation (PCM) data, PS data, and the like that use a raw channel, such as the SIPC message. The data exchanged between the AP  300  and the CP  330  may also include a formatted packet channel and an RFS packet channel. Each channel is sent to a related processing block in a driver. If control and data delivery between the AP  300  and the CP  330  is needed, the SIPC  320  may be used. 
         [0042]    If the AP  300  sends a message via the SIPC  320 , an SIPC block of the CP  330  receives the message. Thereafter, the SIPC block analyzes the message and delivers the analysis results to a related block in the form of a message. Each of the parameters included in the message is stored in the form defined in advance with the processing block, and thereafter delivered (e.g., later on). 
         [0043]    Referring to Table 1, an IMS REFRESH SESSION Message is defined. The IMS REFRESH SESSION Message is determined based on 0x07 in a Sub CMD field that the message corresponds to an IMS refresh session message. The SIPC block calls a relevant function depending on 0x1 (start), 0x2 (stop), and 0x3 (init) in an Operation field. 
         [0044]    The CP  330  includes a voice engine  332 , a PDCP filter  334 , a TCP/IP  336 , and the SIP processor  338 . 
         [0045]    The PDCP filter  334  performs filtering on the received voice packet and/or SIP message. Upon receiving an SIP message from the network, the PDCP filter  134  according to the related art (e.g., as illustrated in  FIG. 1 ) sends the received SIP message from the CP  130  of the terminal to the SIP stack  115  in the AP  100 . 
         [0046]    However, according to exemplary embodiments of the present invention, the PDCP filter  334  operates as follows. 
         [0047]    An exemplary embodiment of the present invention in which there is no terminal user input will is described below. 
         [0048]    According to exemplary embodiments of the present invention, upon receiving a voice packet from the network, the PDCP filter  334  transfers the received voice packet to the voice engine  332  via the TCP/IP  336 . The voice engine  332  processes the received voice packet and transmits the received voice packet via the TCP/IP  336 . Processing the voice packet received from the network may be formed in a similar or same way as the procedure according to the related art. 
         [0049]    In contrast, upon receiving an SIP message, the PDCP filter  334  determines whether the received SIP message corresponds to an SIP update request message. In other words, the PDCP filter  334  extracts an SIP update request message. If the received SIP message corresponds to an SIP update request message, the PDCP filter  334  sends the SIP update request message to the SIP processor  338  in the CP  330  via the TCP/IP  336 , instead of sending the SIP update request message to the AP  300 . 
         [0050]    Upon receiving the SIP update request message, the SIP processor  338  generates a response message (e.g., an SIP update response message) to the SIP update request message, and sends the response message to the network via the TCP/IP  336 . 
         [0051]      FIG. 4  is a flowchart illustrating an operation of a terminal according an exemplary embodiment of the present invention. 
         [0052]    Referring to  FIG. 4 , an operation of a terminal that consumes relatively low power (e.g., to process an SIP protocol) according an exemplary embodiment of the present invention is illustrated. It will be assumed that before step  401 , during initial VoLTE call setup, the IMS stack  315  in the AP  300  transfers a parameter for handling an SIP update request message to the SIP processor  338  in the CP  330  by session refresh IPC. 
         [0053]    In step  401 , in a situation in which there is no terminal user input, the PDCP filter  334  receives an SIP message/voice packet from the network. 
         [0054]    In step  403 , the PDCP filter  334  determines whether the received SIP message corresponds to an SIP update request message based on an SIP protocol. 
         [0055]    If the PDCP determines that the SIP message corresponds to an SIP update request message in step  403 , then the PDCP proceeds to step  405  in which the PDCP filter  334  sends the SIP update request message to the SIP processor  338  in the CP  330  via the TCP/IP  336 , instead of sending the SIP update request message to the AP  300 . 
         [0056]    In step  407 , upon receiving the SIP update request message, the SIP processor  338  generates an SIP update response message in response to the SIP update request message. 
         [0057]    In step  409 , the SIP processor  338  sends the generated SIP update response message to the network via the TCP/IP  336 . 
         [0058]    Conversely, if the PDCP filter  334  determines that the received message does not correspond to an SIP update request message in step  403  (e.g., if the received message corresponds to a voice packet), then the terminal proceeds to step  411  in which the terminal allows the voice engine  332  to process the voice packet. 
         [0059]    According to exemplary embodiments of the present invention, through this process, the AP is not required to wake up to handle an SIP update request message based on the SIP protocol during a VoLTE call, thereby contributing to a reduction in power consumption of the terminal. 
         [0060]    Exemplary embodiments of the present invention may be implemented as computer-readable codes in non-transient computer-readable recording media. The non-transient computer-readable recoding media may include all kinds of recording devices storing computer-readable data. Examples of the recording media may include Read Only Memory (ROM), Random Access Memory (RAM), Compact Disk (CD)-ROM, magnetic tape, floppy disk, optical data storage device, and the like. 
         [0061]    As is apparent from the foregoing description, according to exemplary embodiments of the present invention, the AP is not required to wake up to handle an SIP update request message upon receiving a VoLTE voice call, thereby contributing to a reduction in power consumption of the terminal during a VoLTE call. 
         [0062]    If there is a need to process an SIP protocol in a situation in which there is no user input, the terminal processes the SIP protocol not in the AP but in the CP, thereby reducing the power consumption of the terminal. 
         [0063]    For example, the terminal enables the AP only in the situation in which there is a user input (e.g., only when the user takes an action of making or receiving a voice call), thereby reducing the power consumption of the terminal. 
         [0064]    While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.