Patent Publication Number: US-2018041962-A1

Title: Control method and system in a communication system

Description:
PRIORITY 
     This application is a Continuation Application of U.S. patent application Ser. No. 14/321,474 filed in the U.S. Patent and Trademark Office on Jul. 1, 2014, which is a Continuation Application of U.S. patent application Ser. No. 13/237,464 filed in the U.S. Patent and Trademark Office on Sep. 20, 2011, now U.S. Pat. No. 8,767,624, issued on Jul. 1, 2014, which is a Divisional Application of U.S. patent application Ser. No. 11/865,480 filed in the U.S. Patent and Trademark Office on Oct. 1, 2007, which claims priority under 35 U.S.C. §119(a) to a Korean Patent Application filed in the Korean Intellectual Property Office on Sep. 30, 2006 and assigned Serial No. 10-2006-0096685, and a Korean Patent Application filed in the Korean Intellectual Property Office on Apr. 27, 2007 and assigned Serial No. 10-2007-0041644, the contents of each of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention generally relates to a communication system, and in particular, to a control method and system for providing communication services to users at high speed in a communication system that provides communication services of various types to users. 
     Description of the Related Art 
     In general communication systems, power consumption of a Mobile Station (MS) acts as an important factor of the entire system. Therefore, an idle mode operation and a corresponding active mode operation of an MS have been proposed to minimize power consumption of the MS. Generally, when an MS has no data to exchange with a Radio Access Station (RAS) while the communication system is providing a communication service to a user in the active mode, the MS transitions from the active mode to the idle mode in an operation mode by performing a de-registration operation. However, when the RAS has a service to provide to the MS while the MS operates in the idle mode, the RAS sends a Mobile_Paging-Advertisement (MOB_PAG-ADV) message, or a paging message, to the MS, so the MS transitions to the active mode. An MOB_PAG-ADV message, as used herein, refers to a broadcasting message that an RAS sends to all associated MSs in a broadcasting manner, and the RAS uses a Media Access Control (MAC) address hash value of a corresponding MS among the MSs receiving the MOB_PAG-ADV message to notify the associated MS whether the MS will transition from the idle mode to the active mode. The MS that will transition to the active mode upon receipt of the MOB_PAG-ADV message previously activates, to the active state, application programs of all communication service types supportable by the MS to receive data from the RAS. That is, upon receipt of the MOB_PAG-ADV message from the RAS, the MS activates application programs of all service types so that the MS can receive all available communication services associated with the RAS. Thereafter, upon receipt of data of a particular service type from the RAS after activating application programs of all service types as described above, the MS detects a service type of the received data, and then receives a communication service through use of an application program corresponding to the detected service type. 
     In a communication system as described above, various functions using communication technology for an MS tend to be implemented and united in the MS. Therefore, such an MS typically includes therein modules for performing various functions. For example, an MS may be configured as a Personal Computer (PC) such as laptop, a Personal Digital Assistant (PDA), a notebook PC, a Portable Multimedia Player (PMP), an Ultra Mobile PC (UMPC), etc. In addition, an MS can further include a separate external MS-assistant communication module operating in association with the MS, for example, can include headset, small communication MS, etc. 
     An above-described MS typically keeps a Power-On State and supplies power to all modules of the MS during a communication service. If a communication function ends after the communication service through the MS expires, the MS normally performs a Power-Off operation, or transitions to a Power Save state. This is to take into account a limited power resource, i.e. limited battery power, of the MS. 
     When a user of an MS desires to receive a communication service using the MS, he/she should transition to the Power-On State by supplying again power to the MS, and in the communication system, there is an increasing tendency that the MS needs to always operate in a Power-On State. 
     As described above, when an RAS has a communication service to provide to a MS, i.e. has data of a particular service type to transmit to the MS, the RAS sends a MOB_PAG-ADV message to activate application programs of all service types included in the MS, causing unnecessary waste of power of the communication system, especially the MS. 
     In addition, in order to smoothly receive the communication service, the RAS and the MS should operate in the Power-On State, and power is continuously supplied even to the unused modules, causing unnecessary power waste. Therefore, a need exists for a control method and system for controlling power of an MS in a communication system. 
     SUMMARY OF THE INVENTION 
     The present invention substantially addresses at least the above-described problems and/or disadvantages and provides at least the advantages described below. Accordingly, an aspect of the present invention is to provide a control method and system in a communication system. 
     Another aspect of the present invention is to provide a control method and system for controlling power of an MS in a communication system. 
     Another aspect of the present invention is to provide a control method and system for providing a communication service without power waste in a communication system supporting communication services of various types. 
     According to one aspect of the present invention, there is provided a power control method by a first device in a communication system, including activating a first communication module by supplying power to the first communication module without supplying power to a second communication module, receiving data using the first communication module, activating the second communication module by supplying power to the second communication module for transmitting the data to a second device using the second communication module, wherein the second device interacts with the first device and is separated from the first device, transmitting the data to the second device using the second communication module, and interrupting the power supply to the second communication module, if the data transmission is completed. 
     According to another aspect of the present invention, there is provided a first device in a communication system, including a first communication module configured to perform wireless communication, a second communication module configured to communicate with a second device, wherein the second device interacts with the first device and is separated from the first device, and a control module configured to activate the first communication module by supplying power to the first communication module without supplying power to the second communication module, receive data by controlling the first communication module, activate the second communication module by supplying power to the second communication module for transmitting the data to the second device using the second communication module, transmit the data to the second device using the second communication module, and interrupt the power supply to the second communication module, if the data transmission is completed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a block diagram of a communication system according to the present invention; 
         FIG. 2  is a signaling diagram illustrating a transmission/reception flow of a paging signal in a communication system according to the first embodiment of the present invention; 
         FIG. 3  is a block diagram of an MS in a communication system according to the first embodiment of the present invention; 
         FIG. 4  is a block diagram of an MS for performing control in a communication system according to the first embodiment of the present invention; 
         FIG. 5  is a flowchart illustrating an operation of an MS in a communication system according to the present invention; 
         FIGS. 6A and 6B  are block diagrams of an MS for performing power control in a communication system according to second and third embodiments of the present invention; 
         FIG. 7  is a diagram illustrating a state transition diagram based on a power state of an MS in a communication system according to the present invention; 
         FIGS. 8A and 8B  are diagrams illustrating an implemented sub-display module of an MS according to the present invention; 
         FIG. 9  is a flowchart illustrating a first example of a power control operation of an MS according to the present invention; 
         FIG. 10  is a flowchart illustrating a second example of a power control operation of an MS according to the present invention; 
         FIG. 11  is a diagram illustrating an MS with an MS-assistant device according to the present invention; 
         FIG. 12  is a flowchart illustrating a third example of a power control operation of an MS with an MS-assistant device according to the present invention; and 
         FIG. 13  is a flowchart illustrating a fourth example of a power control operation of an MS with an MS-assistant device according to the present invention. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for clarity and conciseness. 
     The present invention provides a control method and system in a communication system. 
     The present invention, as described below, provides a control method and system in a communication system, for example, in an Institute of Electrical and Electronics Engineers (IEEE) 802.16 communication system, which is a Broadband Wireless Access (BWA) communication system. The BWA communication systems described below provide communication services of various types to users, and also provides high-speed communication services having various Quality of Service (QoS) classes. Although the present invention described below refers to IEEE 802.16 communication systems, by way of example, the control method and system provided by the present invention can also be applied to other communication systems. 
     In addition, the present invention provides a control method and system between a Mobile Station (MS) and a Radio Access Station (RAS) serving as a Base Station (BS) in a communication system. For example, the present invention, described below, provides a control method and system in which when an RAS has data to transmit to an MS, i.e. has a communication service to provide to a user, while the MS and the RAS are operating in the idle mode, the RAS sends a Mobile_Paging-Advertisement (MOB_PAG-ADV) message, or a paging message, to the MS in order to minimize power consumption of the MS. 
     The MOB_PAG-ADV message includes service information corresponding to a service type of the data to be transmitted to the MS. In the idle mode, the MS receives a MOB_PAG-ADV message including service information corresponding to a service type of the data to be transmitted to the MS itself, thereby recognizing a service type of the data to be transmitted upon transition of the MS from the idle mode to the active mode. As a result, when the MS makes transition to the active mode, the MS previously activates, to the active state, only the application corresponding to the recognized service type among the applications of all communication service types supportable by the MS to receive data from the RAS. That is, upon receipt of a MOB_PAG-ADV message including service information corresponding to a service type of its data to be transmitted from the RAS, the MS activates an application corresponding to the service type to receive a communication service by receiving data of a particular service type to be transmitted by the RAS. Upon receipt of data of the particular service type from the RAS after activating the application of the service type corresponding to the service information included in the MOB_PAG-ADV message, the MS receives a communication service through use of the activated application. 
     In this manner, in a communication system according to the present invention, when the RAS has a communication service to provide to the MS, i.e. has data of a particular service type to transmit to the MS, the RAS sends to the MS a MOB_PAG-ADV message including service information corresponding to the service type of the transmission data, and upon receipt of the MOB_PAG-ADV message, the MS can activate only the application of the service type corresponding to the service information, i.e. only the application corresponding to the service type of the data to be transmitted by the RAS, thereby preventing unnecessary waste of power and memory of the communication system, especially the MS. In addition, the MS, because it recognizes a service type of the data to be transmitted by the RAS by receiving the MOB_PAG-ADV message, can share only the resource corresponding to the transmission data, thereby preventing resource waste. When the communication system provides a communication service to the user, in other words, when there is data exchange between the RAS and the MS, the MS previously activates an application corresponding to the data to be exchanged, thereby facilitating fast data transmission/reception. With reference to  FIG. 1 , a description will now be made of an example of a communication system according to the present invention. 
       FIG. 1  shows a communication system according to the present invention. 
     In  FIG. 1 , the communication system includes an MS  101  for making an access to the communication system to receive a communication service, an RAS  103 , serving as a BS as described above, for exchanging data with the MS  101 , an Access Control Router (ACR)  107 , an Internet Protocol (IP)-connected to the RAS  103  via an IP network  105 , for controlling the RAS  103 , and servers, IP-connected to the ACR  107  via an IP network  109 , for providing a communication service to the MS  101  via the ACR  107 , for example, a Video on Demand and Audio on Demand (VoD/AoD) server  111  for providing video and audio services, a web server  113  for providing an Internet web service, a Voice over IP and Virtual Terminal (VoIP/VT) server  115  for providing voice and image services, and a messenger server  117  for providing an Instant Messaging (IM) service. 
     The RAS  103  processes a wireless access standard with the MS  101  accessing the communication system, i.e. processes the IEEE 802.16 standard, because the communication system herein is assumed to be an IEEE 802.16 communication system, and performs a function of the BS, i.e. performs an initial procedure for exchanging data with the MS  101  and a data transmission/reception function. In other words, the RAS  103  performs Radio Frequency (RF) signal processing with the MS  101 , performs functions in a Physical (PHY) layer and a Media Access Control (MAC) layer, and performs scheduling and ranging operation with the MS  101 . In addition, the RAS  103  transmits, to the MS  101 , initialization and communication system information of the cell capable of receiving a communication service therefrom, and controls inter-sector handoff of the MS  101  when the MS  101  moves between sectors in the cell. 
     The ACR  107  performs a function of controlling the RAS  103 , and the one ACR  107  can control multiple RASs. In addition, the ACR  107  transmits communication services provided by the servers  111 ,  113 ,  115  and  117  to the RAS  103  to provide the communication services to the MS  101  accessing the communication system, and to this end, performs authentication for the MS  101 , MAC protocol processing, IP address allocation, routing, etc. More specifically, the ACR  107  performs a function in a MAC layer, which is an upper layer of the MAC layer where the RAS  103  performs the function, controls handoff between RASs and also controls the idle mode and active mode between MS  101  and the RAS  103 , and performs authentication and accounting for the MS  101 , and a proxy function necessary for account management. The IP networks  105  and  109  process interfacing with the RAS  103 , the ACR  107 , and the servers for providing communication services, i.e. the VoD/AoD server  111 , the web server  113 , the VoIP/VT server  115 , and the messenger server  117 , thereby forming a network. With reference to  FIG. 2 , a detailed description will now be made of signal transmission/reception in a communication system according to the present invention. 
       FIG. 2  is a signaling diagram illustrating a transmission/reception flow of a paging signal in a communication system according to the present invention.  FIG. 2  shows a schematic transmission/reception flow of a signal where while providing a communication service to a user, the communication system, after transitioning from the active mode to the idle mode due to absence of data to be exchanged between the MS and the RAS, transitions back to the active mode as it has a service to provide to the user in the idle mode. 
     Referring to  FIG. 2 , if, as assumed above, an MS  201  has no data to be exchanged with a RAS  203  in the active mode, the MS  201  sends a De-Registration Request (DREG-REQ) message to the RAS  203  to transition from the active mode to the idle mode in step  211 . Then the RAS  203  sends a De-Registration Request to an ACR  205  in response to the received DREG-REQ message in step  213 . In response to the Request, the ACR  205  sends a De-Registration Response so that the RAS  203  and the MS  201  transition from the active mode to the idle mode in step  215 . Thereafter, the RAS  203  sends a De-Registration Command (DREG-CMD) message to the MS  201  in response to the Response from the ACR  205  in step  217 . Then the MS  201 , the RAS  203  and the ACR  205  operate in the idle mode in step  219 . 
     If the ACR  205  has, as user traffic, a communication service to provide to the MS  201 , i.e. has data to transmit to the MS  201  from an arbitrary server among the servers for providing communication services, described in  FIG. 1  in step  220 , the ACR  205  includes, in a Paging Advertisement, service information corresponding to a service type of the transmission data, i.e. a service type of the data to be transmitted by the arbitrary server that desires to provide a particular communication service to the MS  201 , and instructs the RAS  203  to send the Paging Advertisement to the MS  201  in step  221 . Then the RAS  203  broadcasts, to the MS  201 , a MOB_PAG-ADV message including service information corresponding to the service type of the data to be transmitted to the MS  201  in step  223 . As described above, in the communication system according to the present invention, the MOB_PAG-ADV message including service information corresponding to a service type of the data to be transmitted to the MS  201 , i.e. the MOB_PAG-ADV message according to the present invention, includes service information corresponding to the service type of the data to be transmitted to the MS  201 , in a TLV (Type, Length, Value) Encoded Information field or a Reserved field of the MOB_PAG-ADV message shown in Table 1 below. Table 1 shows a format of a MOB_PAG-ADV message, a description of each field of which will be omitted herein. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Size 
                   
               
               
                 Syntax 
                 (bits) 
                 Notes 
               
               
                   
               
             
            
               
                 MOB_PAG- 
                 — 
                 — 
               
               
                 ADV_Message_format( ) { 
               
            
           
           
               
               
               
               
            
               
                   
                 Management Message Type = 62 
                 8 
                 — 
               
               
                   
                 Num_Paging_Group_IDs 
                 8 
                 Number of Paging Group IDs in 
               
            
           
           
               
               
            
               
                   
                 this message 
               
            
           
           
               
               
               
               
            
               
                   
                 For (i=0; 
                 — 
                 — 
               
            
           
           
               
            
               
                 i&lt;Num_Paging_Group_IDs; i++) { 
               
            
           
           
               
               
               
               
            
               
                   
                 Paging Group ID 
                 8 
                 — 
               
            
           
           
               
               
               
               
            
               
                   
                 } 
                 — 
                 — 
               
               
                   
                 Num_MACs 
                 8 
                 Number of MS MAC addresses 
               
               
                   
                 For (i=0; j&lt;Num_MACs; j++) { 
                 — 
                 — 
               
            
           
           
               
               
               
               
            
               
                   
                 MS MAC Address hash 
                 24  
                 The hash is obtained by 
               
            
           
           
               
               
            
               
                   
                 computing a CRC24 on the MS 
               
               
                   
                 48-bit MAC address. The 
               
               
                   
                 polynomial for the calculation is 
               
               
                   
                 0x1864CFB. 
               
            
           
           
               
               
               
               
            
               
                   
                 Action Code 
                 2 
                 Paging action instruction to MS 
               
            
           
           
               
               
            
               
                   
                 0b00 = No Action Required 
               
               
                   
                 0b01 = Perform Ranging to 
               
               
                   
                 establish location and 
               
               
                   
                 acknowledge message 
               
               
                   
                 0b10 = Enter Network 
               
               
                   
                 0b11 = reserved 
               
            
           
           
               
               
               
               
            
               
                   
                 Reserved 
                 6 
                   
               
            
           
           
               
               
            
               
                   
                 } 
               
            
           
           
               
               
               
            
               
                 padding 
                 variable 
                 Padding bits to ensure octet 
               
               
                   
                   
                 aligned 
               
               
                 TLV Encoded Information 
                 variable 
                 TLV specific 
               
               
                 } 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     Upon receipt of the MOB_PAG-ADV message including the service information corresponding to the service type of the data to be transmitted to the MS  201  from the RAS  203 , the MS  201  activates an application program corresponding to the service type of the transmission data, and then sends a Ranging-Request (RNG-REQ) message to the RAS  203  in step  225 . In this case, the MS  201  recognizes a service type of the data to be transmitted, i.e. a type of the communication service to be provided from the servers described in  FIG. 1 , upon its transition from the idle mode to the active mode, by receiving the MOB_PAG-ADV message including the service information corresponding to the service type of the data to be transmitted to the MS  201  in the idle mode. As a result, the MS  201 , when it makes transition to the active mode, previously activates, to the active state, only the application program corresponding to the recognized service type among the application programs of all communication service types supportable by the MS  201  to receive data from the RAS  203 . 
     Thereafter, the RAS  203  sends a Ranging Setup to the ACR  205  in response to the received RNG-REQ message in step  227 , and the ACR  205  sends a Ranging Setup Reply to the RAS  203  in step  229 . Then the RAS  203  sends a Ranging-Response (RNG-RSP) message, or a response message to the RNG-REQ message, to the MS  201  in step  231 . Upon receipt of the RNG-RSP message, the MS  201  sends a Subscriber Station&#39;s Basic Capability Negotiation Request (SBC-REQ) message to the RAS  203  in step  233 . The SBC-REQ message herein is a MAC message that the MS  201  sends for negotiation on its basic capability with the RAS  203 , and the SBC-REQ message can include information on a modulation and coding scheme supportable by the MS  201 . 
     The RAS  203  detects a modulation and coding scheme supportable by the MS  201 , included in the SBC-REQ message received from the MS  201 , and then sends a Subscriber Station&#39;s Basic Capability Negotiation Response (SBC-RSP) message, or a response message to the SBC-REQ message, to the MS  201  in step  235 . In addition, the RAS  203  sends a Basic Capability Setup of the MS  201  to the ACR  205  in step  237 , and the ACR  205  sends a Basic Capability Setup Acknowledgment (ACK) to the RAS  203  in step  239 . As the MS  201  receives the SBC-RSP message from the RAS  203  in this manner, the MS  201  completes its basic capability negotiation, completing authentication with an authentication server  207  in step  241 . 
     Thereafter, the MS  201  sends a Registration Request (REG-REQ) message to the RAS  203  in step  243 . The REG-REQ message herein includes MS registration information of the MS  201 . Upon receipt of the REG-REQ message, the RAS  203  detects MS registration information included in the REG-REQ message, and sends a Registration Request for the MS  201  to the ACR  205  in step  245 . Then the ACR  205  acquires a user profile, i.e. a profile of the MS  201 , from the authentication server  207  in step  247 , and then sends a Registration Response to the RAS  203  in response to the Registration Request in step  249 ). Thereafter, the RAS  203  registers the MS  201  therein, and sends a Registration Response (REG-RSP) message, or a response message to the REG-REQ message, to the MS  201  in step  251 . 
     Next, the ACR  205  and the authentication server  207  perform QoS Policy Negotiation on the data to be transmitted to the MS  201  in step  253 , and then the ACR  205  sends a Service Add Request to the RAS  203  in step  255 . Then the RAS  203  sends a Dynamic Service Addition Request (DSA-REQ) message to the MS  201  in step  257 . Upon receipt of the DSA-REQ message from the RAS  203 , the MS  201  sends a Dynamic Service Addition Response (DSA-RSP) message, or a response message to the DSA-REQ message, to the RAS  203  in step  259 . 
     Then the RAS  203  sends a Service Add Response to the ACR  205  in response to the Service Add Request in step  261 , and sends a Dynamic Service Addition Acknowledgment (DSA-ACK) message to the MS  201  in step  263 . Through use of theses procedures, an active data session is kept between the MS  201  and the communication system, i.e. between the MS  201 , and the RAS  203  and ACR  205  in step  265 . In this case, the MS  201  transmits/receives data through use of the application program that the MS  201  has previously activated according to the MOB_PAG-ADV message including the service information corresponding to the service type of the data to be transmitted in step  225 . With reference to  FIG. 3 , a description will now be made of a second example of an MS in a communication system according to the present invention. 
       FIG. 3  shows a first example of an MS in a communication system according to the present invention. 
     In  FIG. 3 , the MS includes an input unit  301  for receiving input information from a user, an RF module  303  for processing data exchanged with a RAS, a CPU  305  for processing all operations of the MS, a modem  304  for processing data exchanged with the RF module  303 , a memory  307  for storing information of the MS, and an output unit  309  for providing the transmission/reception data of the MS and the processing results to the user. With reference to  FIGS. 4 and 5 , a description will now be made of operation of the MS of  FIG. 3 , related to the present invention. 
       FIG. 4  shows modules for the MS of  FIG. 3  for performing control in a communication system according to the present invention. 
     As shown in  FIG. 4 , the MS includes a PHY module  401  for processing an MS operation in a PHY layer, a MAC module  403  for processing an MS operation in a MAC layer, a device driver  405  for processing operations of all elements of the MS, an IP module  407  for processing an IP connection of the MS, a Transmission Control Protocol (TCP)/User Datagram Protocol (UDP) module  409  for processing a data transmission/reception operation of the MS, a service management module  411  for controlling application programs of the MS according to a service type of the data transmitted/received by the MS, and application programs for processing the data according to a communication service type supportable by the MS, e.g. a service type of the data that the MS exchanges with a RAS, to allow the MS to exchange the data with the RAS. For example, the application programs can include a VoIP application program  413  for processing data of a voice service type, a VT application program  415  for processing data of an image service type, a VoD application program  417  for processing data of a video service type, an AoD application program  419  for processing data of an audio service type, an IM application program  421  for processing data of an IM service type, a web application program  423  for processing data of an Internet web service type, and other application programs  425  for processing data of other service types. 
     Upon receipt of a MOB_PAG-ADV message including service information corresponding to a service type of the data to be transmitted to the MS itself from the RAS in the idle mode, the MS activates only the application program corresponding to the service information included in the received MOB_PAG-ADV message, e.g. corresponding to the service type of the data to be transmitted to the MS itself. Thereafter, upon receipt of data of a particular service type from the RAS, the MS receives a communication service by processing the data through use of the application program already activated after receiving the MOB_PAG-ADV message, e.g. through use of the application program corresponding to the service type of the received data. 
     For example, when data to be transmitted to the MS is data of an IM service type, the MOB_PAG-ADV message includes service information indicating that a service type of the data to be transmitted to the MS is an IM service, and upon receipt of the MOB_PAG-ADV message including the IM service information, the MS activates only the IM application program  421  among the application programs described above. Thereafter, when an active data session between the MS and the communication system is kept as described in  FIG. 2 , the MS exchanges data of the IM service type with the communication system, e.g. receives the IM service. With reference to  FIG. 5 , a description will now be made of an operation of the MS of  FIG. 3  in a communication system according to the present invention. 
       FIG. 5  shows an operation of an MS in a communication system according to the present invention. 
     In  FIG. 5 , in step  501 , the MS receives from an RAS a MOB_PAG-ADV message including information on a communication service that the MS will receive from a communication system, e.g. including service information corresponding to a service type of the data to be transmitted to the MS itself. Thereafter, in step  503 , the MS recognizes a type of the communication service, received through the service information included in the MOB_PAG-ADV message, e.g. the service type of the data to be transmitted to the MS itself, and activates an application program corresponding to the recognized service type of the data to exchange the data with the RAS. Thereafter, in step  505 , the MS shares resource corresponding to the recognized service type of the data, i.e. connects a channel to the RAS, to receive the data to be transmitted from the RAS. 
     If a channel is connected to the RAS in step  505 , the MS receives the data from the RAS over TCP/IP in step  507 . In step  509 , the MS distributes the received data to the application corresponding to the service type, e.g. allows the application program previously activated in step  503  to process the received data. Thereafter, in step  511 , the MS exchanges data with the RAS through use of the application program, thereby receiving the communication service. 
     As described above, in the communication system according to the present invention, if the RAS has a communication service to provide to the MS, i.e. has data of a particular service type to transmit to the MS, it sends to the MS a MOB_PAG-ADV message including service information corresponding to the service type of the transmission data, and upon receipt of the MOB_PAG-ADV message, the MS activates only the application program of the service type corresponding to the service information, i.e. activates only the application program corresponding to the service type of the data that the RAS will transmit, thereby preventing unnecessary waste of power and memory of the communication system, especially the MS. In addition, because the MS receives a MOB_PAG-ADV message and recognizes a service type of the data to be transmitted by the RAS depending on the received MOB_PAG-ADV message, the MS can share only the resource corresponding to the transmission data, thereby preventing waste of the resource. When the communication system provides a communication service to the user, in other words, when there is data exchange between the RAS and the MS, the MS previously activates an application program corresponding to the data to be exchanged, thereby preventing power waste and thus facilitating fast reception of the communication service. Before a description of power control for controlling power of modules in the MS is given, a second example of an MS for controlling power in a communication system according to the present invention will now be described with reference to  FIGS. 6A and 6B . 
       FIGS. 6A and 6B  shows second and third examples of an MS for performing power control in a communication system according to the present invention. 
     In  FIG. 6A , the MS includes an input module in the form of a key board/button module  611  for receiving user input information from a user through use of a key board/button, a sub-display module  613  for displaying a received message or a received service request for the user, a main display module  615  for displaying functions provided by the MS for the user, an audio module  617  for processing an audio signal, a disk module  619  for storing information, and a power supply module  621  for supplying power to the modules of the MS. The MS of  FIG. 6A  also includes a main memory  623 , used as a main memory of the MS, for storing information based on an operation of the MS, a main controller in the form of a main control processor  625  for controlling operations of all modules in the MS, a communication memory  627  for storing information based on a communication service through use of a communication module of the MS, a communication controller in the form of communication processor  629  for controlling communication modules, a wireless broadband communication transmitter/receiver  631  for performing data exchange with the RAS, and a wireless Local Area Network and Personal Area Network (LAN/PAN) communication transmitter/receiver  633  for performing data exchange with an MS-assistant device that interacts with the MS and can perform simple data communication such as voice, for example, performing data exchange via Wireless Local Area Network (WLAN), Personal Area Network (PAN), Bluetooth, etc. 
     As for separate basic communication modules for performing separate communication operations, a basic communication block includes the communication memory  627 , the communication processor  629 , the first transmitter/receiver  631  and the second transmitter/receiver  633 . 
     The MS includes a separate external MS-assistant device interacting with the MS, for example, includes a headset, a small communication MS, etc. Therefore, the second transmitter/receiver  633  is used for communication with the external MS-assistant device. The second transmitter/receiver  633  can be disposed in either inside or outside of the communication block. 
     In addition, the second transmitter/receiver  633  can selectively be included in the MS according to use/non-use of the external MS-assistant device. 
       FIG. 6A  shows where a communication-only processor for communication and a communication-only memory are separately provided. In this case, the main control processor  625  can receive the communication service only with the operation of the communication processor  629  in a Power-Off State when the main controller  625  performs in a communication operation. 
       FIG. 6B  shows where the separate communication modules, for example, the communication memory  627  and the communication processor  629 , are not provided. 
     The MS shown in  FIG. 6B  includes an input module  611  for receiving user input information from the user through use of a key board/button, a sub-display module  613  for displaying a received message or a received service request for the user, a main display module  615  for displaying functions provided by the MS for the user, an audio module  617  for processing audio signal, a disk module  619  for storing information, a power supply module  621  for supplying power to the modules of the MS. The MS shown in  FIG. 6B  also includes a main memory  623 , used as a main memory of the MS, for storing information based on an operation of the MS, a main controller  625  for controlling operations of all modules in the MS, a wireless broadband communication transmitter/receiver  631  for performing data exchange with the RAS, and a wireless LAN/PAN communication transmitter/receiver  633  for performing data exchange with an MS-assistant device that interacts with the MS and can perform simple data communication such as voice, for example, performing data exchange via WLAN, PAN, Bluetooth, etc. 
     In  FIG. 6B , operations of the communication memory  627  and the communication processor  629  of  FIG. 6A  are performed by the main memory  623  and the main control processor  625 , respectively. Therefore, in the MS shown in  FIG. 6B , the communication block includes the main memory  623 , the main processor  625 , the first transmitter/receiver  631 , and the second (or LAN/PAN) transmitter/receiver  633 . 
     A description of the operations of the modules shown in  FIGS. 6A and 6B  will be omitted herein for simplicity. 
     In the MS&#39;s shown in  FIGS. 6A and 6B , solid lines between the modules are paths via which signal information and data are transmitted, and dotted lines between the modules are paths via which power is supplied to the modules. Some modules of the MS, for example, the input module, the main controller and the communication controller, can control the power supply module  621 . With reference to  FIG. 7 , a description will now be made of state transition based on a power state of the MS, provided by the present invention. 
       FIG. 7  shows a state transition diagram based on a power state of an MS in a communication system according to the present invention. 
     Referring to  FIG. 7 , the MS according to the present invention includes, for example, a Power-On State, a Power-Off State, a Power Save_1 State, and a Power Save_2 State. 
     Basically, the MS is in the Power-Off State, when no power is supplied thereto. In the state where no power is supplied to all elements in the MS, the MS performs no operation. 
     The MS enters the Power-On State upon receipt of a Power-On request from the user through use of a power button and the like. In this state, power is supplied to all elements in the MS, maximizing the power consumption of the MS. 
     The present invention provides the Power Save_1 State and the Power Save_2 State, by way of example. In the Power Save_1 State and the Power Save_2 State, power is supplied only to some of the modules in the MS, and power supply to other modules except for the power-supplied modules is interrupted. The MS can enter the Power Save_1 State and the Power Save_2 State, if its user does not use the MS for a time or makes a request for state transition through use of an input module. 
     The Power Save_1 State interrupts the power supply to all modules in the MS except for, for example, the basic communication block. Therefore, in the Power Save_1 State, the MS, though it can communicate with the RAS, does not enable additional functions performed using the non-power-supplied modules. Meanwhile, the Power Save_1 State can be classified into a Power Save_1_Active State where all the communication blocks normally operate in the active state, and a Power Save_1_Idle State where the communication blocks operate in the idle state, and these states correspond to the active mode and the idle mode of the general MS, respectively. 
     The Power Save_2 State interrupts the power supply to all modules in the MS except for, for example, the basic communication block and the sub-display module. Therefore, in the Power Save_2 State, the MS can communicate with the RAS and can display a received message and/or the contents received at a service request through use of the sub-display module. However, the MS does not enable the additional functions performed using the non-power-supplied modules except for the communication block and the sub-display module. Similarly, the Power Save_2 State can be classified into a Power Save_2 Active State where all the communication blocks normally operate in the active state, and a Power Save_2_Idle State where the communication blocks operate in the idle state, and these states correspond to the active mode and the idle mode of the general MS, respectively. In the Power Save_2 State, when the sub-display module is not supported or use of the main display module is possible, the MS can enable the main display module rather than the sub-display module. 
     In  FIG. 7 , state transition between the individual states is possible depending on the MS&#39;s operation state and/or the MS user&#39;s request. With reference to  FIGS. 8A and 8B , a description will now be made of implementation of the sub-display module. 
       FIGS. 8A and 8B  show an implemented sub-display module of an MS according to the present invention. 
     Referring to  FIG. 8A , there are shown a variety of main displays of MSs, for example, a Personal Digital Assistants (PDA), a Tablet PC, etc., and sub-display modules can be included inside or outside of the main display modules. 
     Referring to  FIG. 8B , there are shown various external cases of, for example, a Personal Computer (PC) such as laptop, a notebook PC, a Portable Multimedia Player (PMP), a Ultra Mobile PC (UMPC), etc., and similarly, the sub-display modules can be implemented inside or outside of the main display modules. 
     In the Power-On State of  FIG. 7 , the MS can transition to the Power-Off State, the Power Save_1 State and the Power Save_2 State depending on the MS&#39;s state and/or the user input of the MS. In the Power-On State, the MS does not need to power ON all modules in the MS in performing data communication and respective functions in the MS. With reference to  FIGS. 7 and 9 , a description will now be made of an operation of an MS according to the present invention in the Power Save_1 State. 
       FIG. 9  shows an example of a power control operation of an MS according to the present invention. 
     Referring to  FIG. 9 , in step  911 , the MS operates in a Power Save_1 State. In the Power Save_1 State, an MS, as described above, enables only the modules in the communication block, and supplies power only to the modules included in the communication block. 
     In step  913 , the MS determines whether the MS has received data. The MS can receive the data, by receiving from a RAS a paging message, for example, a MOB_PAG-ADV message, recognizing a service type of received data depending on the MOB_PAG-ADV message, and previously activating to the active state only the application program corresponding to the recognized service type, as described above. When it is determined in step  913  that the MS has received no data, the MS waits for data. 
     However, when it is determined in step  913  that the MS has received data, the MS proceeds to step  915  where the MS enables a sub-display module by supplying power to the sub-display module, and then proceeds to step  917 . When the MS supplies power to the sub-display module, the MS enters a Power Save_2 State. 
     In step  917 , the MS displays a message corresponding to the received data on the sub-display module, and then proceeds to step  919 . The MS displays all or a part of a text message corresponding to the received data through use of the sub-display module. In addition, if the received data is service request-related data, the MS displays a service request message corresponding to the data through use of the sub-display module. 
     In step  919 , the MS determines whether an input from the user, e.g. user input information, is detected. 
     If it is determined in step  919  that no user input information is detected within a certain time, the MS proceeds to step  925  where the MS powers OFF the sub-display module. After powering off the sub-display module, the MS operates in the Power Save_1 State. Alternatively, the MS can operate in the Power Save_2 State where the sub-display module and the communication block are enabled, instead of performing step  925 . 
     However, when it is determined in step  919  that user input information is detected, the MS proceeds to step  921  where it powers ON the remaining modules except for the communication module and the sub-display module in the MS, and then proceeds to step  923 . In step  921 , the MS enters a Power-On State. 
     In step  923 , the MS performs a communication service using the received data, or activates an application program based on a received service request through use of corresponding modules. In this manner, the MS performs an operation appropriate for the application program corresponding to the received data. With reference to  FIGS. 7 and 10 , a description will now be made of an operation of an MS according to the present invention in the Power Save_2 State. 
       FIG. 10  shows another example of a power control operation of an MS according to the present invention. 
     Referring to  FIG. 10 , in step  1011 , the MS operates in a Power Save_2 State. In the Power Save_2 State, the MS enables only the modules in the communication block and the sub-display module, and supplies power only to the modules in the communication block and the sub-display module. 
     In step  1013 , the MS determines whether it has received data. The MS can receive the data, using a paging message, for example, a MOB_PAG-ADV message, as described above, and a detailed description thereof will be omitted herein for simplicity. If it is determined in step  1013  that it has received no data, the MS waits for data. 
     However, if it is determined in step  1013  that it has received data, the MS proceeds to step  1015  where it displays a message corresponding to the received data, and then proceeds to step  1017 . The MS displays all or a part of a text message corresponding to the received data through use of the sub-display module. In addition, when the received data is service request-related data, the MS displays a service request message corresponding to the data through use of the sub-display module. 
     In step  1017 , the MS determines whether an input from the user, i.e. user input information, is detected. 
     If it is determined in step  1017  that no user input information is detected within a time, the MS ends the operation. In this case, when the MS powers OFF the sub-display module, the MS can operate in the Power Save_1 State. 
     However, if it is determined in step  1017  that user input information is detected, the MS proceeds to step  1019  where it powers ON the remaining modules except for the communication modules in the MS and the sub-display module, and then proceeds to step  1021 . In step  1019 , the MS enters the Power-On State. 
     In step  1021 , the MS performs a communication service using the received data, or activates an application program based on a received service request through use of corresponding modules. In this manner, the MS performs an operation appropriate for the application program corresponding to the received data. 
     The operation of an MS, as shown in  FIGS. 9 and 10 , can be controlled by the main controller or the communication controller included in the communication block, as shown in  FIGS. 6A and 6B . In addition, the application program means a program for driving a service available for each individual MS according to each MS&#39;s characteristic. Further, the MS, as described above, receives a paging message from the RAS, recognizes a service type of the data to be received from the RAS depending on the paging message, and previously activates to the active state only the application program corresponding to the recognized service type, thereby reducing the power consumption. With reference to  FIG. 11 , a description will now be made of an operation of an MS including an external MS-assistant device in a communication system according to the present invention. 
       FIG. 11  shows an MS with an MS-assistant device according to the present invention. 
     Referring to  FIG. 11 , an MS  1113  communicates with a RAS  1111 , and transmits a signal received from the RAS  1111  to an MS-assistant device  1115 . 
     The MS-assistant device  1115 , a separate external MS-assistant device interacting with the MS  1113 , can include, for example, a headset, a small communication MS, etc.  FIG. 11  shows where a user performs communication with a separate external assistant device capable of a voice call, when it is inconvenient for the user to perform the voice call through use of such device as a notebook PC. 
     The MS  1113  can transmit the signal received from the RAS  1111  to the MS-assistant device  1115  only with an operation of a communication block, and the communication block further includes a transmission/reception module for transmitting the signal received from the RAS  1111  to the MS-assistant device  1115 . 
     With reference to  FIGS. 7 and 12 , a description will now be made of an operation of an MS according to the present invention that performs communication using the MS-assistant device in the Power Save_1 State. 
       FIG. 12  shows a power control operation of an MS with an MS-assistant device according to the present invention. 
     In  FIG. 12 , in step  1211 , the MS operates in a Power Save_1 State. In the Power Save_1 State, the MS enables only the modules in a communication block, and supplies power only to the modules included in the communication block. In addition, a second transmitter/receiver in the communication module can be either powered ON or powered OFF. 
     In step  1213 , the MS determines whether the MS has received data. The MS can receive the data using, for example, a paging message. When it is determined in step  1213  that the MS has received no data, the MS returns to step  1213  and waits for data. 
     However, if it is determined in step  1213  that the MS has received data, the MS proceeds to step  1215  where it enables a sub-display module by supplying power to the sub-display module, and then proceeds to step  1217 . After supplying power to the sub-display module, the MS enters a Power Save_2 State. 
     In step  1217 , the MS displays a message corresponding to the received data, and then proceeds to step  1219 . The received data can be voice data, and the MS displays the receipt of the data on the sub-display module. 
     In step  1219 , the MS determines whether an input from the user, e.g. user input information, is detected. 
     If it is determined in step  1219  that no user input information is detected within a time, the MS proceeds to step  1229  where it powers OFF the sub-display module and then ends the operation. After powering OFF the sub-display module, the MS operates in the Power Save_1 State. Alternatively, the MS can operate in the Power Save_2 State where the sub-display module and the communication block are enabled, instead of performing step  1229 . 
     However, if it is determined in step  1219  that user input information is detected, the MS proceeds to step  1221  where it powers ON the second transmitter/receiver in the MS, and then proceeds to step  1223 . The second transmitter/receiver enables communication with the MS-assistant device, making it possible to provide a communication service through data exchange between the MS and the MS-assistant device. 
     In step  1223 , the MS performs a communication service through use of the second transmitter/receiver, and then proceeds to step  1225 . 
     In step  1225 , the MS powers OFF the sub-display module and then ends the operation, after terminating the data exchange with the MS-assistant device, e.g. after closing the communication service. After powering OFF the sub-display module, the MS operates in the Power Save_1 State. Alternatively, the MS can operate in the Power Save_2 State where the sub-display module and the communication block are enabled, instead of performing step  1227 . 
     With reference to  FIGS. 7 and 13 , a description will now be made of an operation of an MS according to the present invention that performs communication using the MS-assistant device in the Power Save_2 State. 
       FIG. 13  shows another example of a power control operation of an MS with an MS-assistant device according to the present invention. 
     In  FIG. 13 , in step  1311 , the MS operates in a Power Save_2 State. In the Power Save_2 State, the MS enables only the modules in the communication block and the sub-display module, and supplies power only to the modules in the communication block and the sub-display module. In addition, a second transmitter/receiver in the communication module can be either powered ON or powered OFF. 
     In step  1313 , the MS determines whether the MS has received data. The MS can receive the data using a paging message, for example, a MOB_PAG-ADV message, and a detailed description thereof will be omitted herein for simplicity. If it is determined in step  1313  that it has received no data, the MS waits for data. 
     However, if it is determined in step  1313  that it has received data, the MS proceeds to step  1315  where the MS displays a message corresponding to the received data, and then proceeds to step  1317 . The received data can be voice data, and the MS displays the receipt of the data on the sub-display module. 
     In step  1317 , the MS determines whether an input from the user, i.e. user input information, is detected. 
     If it is determined in step  1317  that no user input information is detected within a time, the MS ends the operation. In this case, when the MS powers OFF the sub-display module, the MS can operate in the Power Save_1 State. 
     However, if it is determined in step  1317  that user input information is detected, the MS proceeds to step  1319  where the MS powers ON the second transmitter/receiver in the MS, and then proceeds to step  1321 . The second transmitter/receiver enables communication with the MS-assistant device, making it possible to provide a communication service through data exchange between the MS and the MS-assistant device. 
     In step  1321 , the MS performs a communication service through use of the second transmitter/receiver, and then proceeds to step  1323 . 
     In step  1323 , the MS ends the operation after terminating the data exchange with the MS-assistant device, i.e. after closing the communication service. In this case, the MS operates in the Power Save_2 State where the sub-display module and the communication block are enabled. In addition, after closing the communication service and powering OFF the sub-display module, the MS can operate in the Power Save_1 State. 
     In  FIGS. 12 and 13 , each user may not check the sub-display module. In this case, steps  1219  and  1317  can be omitted. In this case, the MS can proceed from step  1213  to step  1221 , or can proceed from step  1313  to step  1319 . 
     Further, in  FIGS. 12 and 13 , the MS is generally assumed to transmit voice data, and the MS can send to the communication block a paging message including information on a set port number corresponding to traffic information used by a voice service, thereby transmitting only the voice data to the MS-assistant device. 
     Although the MS receives data using the paging message in  FIGS. 9, 10, 12 and 13 , by way of example, it generally means a first message for resuming communication connection to transmit information in the communication system, for the MS having no wireless communication connection. 
     As can be appreciated from the foregoing description, the present invention can send to the MS a message including information on the communication service type to be provided to the user, thereby preventing unnecessary power waste of the MS. 
     While the invention has been shown and described with reference to certain preferred 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.