Abstract:
A method of receiving a Short Message Service (SMS) message by a mobile station in a wireless communication system is provided. The method includes receiving a paging message including a first field indicating whether there is a broadcast SMS message to be received from a base station, if the first field is set to a value indicating that the broadcast SMS message is to be received, recognizing a broadcast transport Connection IDentifier (CID) indicating a channel over which to transmit the broadcast SMS message, and a data burst allocation region by decoding a broadcast MAP Information Element (IE), and receiving the broadcast SMS message, transmitted using a resource of the data burst allocation region, through the channel over which to transmit the broadcast SMS message.

Description:
PRIORITY 
     This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Industrial Property Office on Sep. 3, 2007, and assigned Serial No. 2007-0088968, the entire disclosure of which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wireless communication system. More particularly, the present invention relates to a system and method for providing a Short Message Service (hereinafter referred to as “SMS”) in a wireless communication system. 
     2. Description of the Related Art 
     There are various services for users in a wireless communication system. More particularly, an SMS service is a service that users frequently use. 
       FIG. 1  illustrates an operation of providing SMS in a conventional Code Division Multiple Access (CDMA) communication system. 
     Referring to  FIG. 1 , a base station performs paging to inform an idle mode mobile station that there is an SMS message to be delivered. Subsequently, the base station receives an ADDS page message from a Mobile Switching Center (MSC), and transmits an SMS message included in the ADDS page message to the mobile station in the form of a data burst message. 
     Along with the growth of communication technology, wideband frequencies are used in next generation wireless communication systems. That is, while conventional 3rd generation wireless communication systems use divided codes, next generation wireless communication systems use divided orthogonal frequencies. For example, the mobile WiMax system that is in the spotlight as a next generation wireless communication system employs an Orthogonal Frequency Division Multiple Access (OFDMA) scheme. 
     As mentioned above, a wireless communication system using divided orthogonal frequencies is different from a CDMA-based wireless communication system. Therefore, the wireless communication system using divided orthogonal frequencies needs to perform a procedure of providing SMS in a different manner from that in the CDMA-based wireless communication system. However, a concrete procedure for providing SMS in a wireless communication system using divided orthogonal frequencies is not yet defined. 
     Therefore, a need exists for a system and method for providing a Short Message Service (SMS) in a wireless communication system. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention is 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 system and method for providing a broadcast SMS message in a wireless communication system using orthogonal frequencies. 
     Further, another aspect of the present invention is to provide a system and method for providing a unicast SMS message in a wireless communication system using orthogonal frequencies. 
     In accordance with an aspect of the present invention, a method of receiving an SMS message by a mobile station in a wireless communication system is provided. The method includes receiving a paging message including a first field indicating whether or not there is a broadcast SMS message to be received from a base station, if the first field is set to a value indicating that the broadcast SMS message is to be received, recognizing a broadcast transport Connection IDentifier (CID) indicating a channel over which to transmit the broadcast SMS message, and a data burst allocation region by decoding a broadcast MAP Information Element (IE), and receiving the broadcast SMS message, transmitted using a resource of the data burst allocation region, through the channel over which to transmit the broadcast SMS message. 
     In accordance with another aspect of the present invention, a method of transmitting an SMS message by a base station in a wireless communication system is provided. The method includes, if there is a broadcast SMS message to be transmitted, transmitting a paging message including a first field set to a value indicating that there is the broadcast SMS message to be transmitted, configuring a broadcast MAP Information Element (IE) including a broadcast transport Connection IDentifier (CID) indicating a channel over which to transmit the broadcast SMS message, and information on a data burst allocation region, and transmitting the broadcast SMS message by using the channel over which to transmit the broadcast SMS message and a resource of the data burst allocation region indicated by the broadcast MAP IE. 
     In accordance with yet another aspect of the present invention, a method of receiving an SMS message by an idle mode mobile station in a wireless communication system is provided. The method includes receiving a paging message from a base station, if a specific field in the paging message is set to a value indicating that a broadcast SMS message is to be transmitted, receiving the broadcast SMS message from the base station, if the specific field in the paging message is set to a value indicating that no broadcast SMS message is to be transmitted, determining if the paging message includes a value indicating the mobile station, if the paging message includes the value indicating the mobile station, identifying an action code field value of the paging message, if the action code field value corresponds to a value indicating that there is a unicast SMS message to be received from the base station, transitioning to an awake mode, and receiving the unicast SMS message from the base station after transitioning to the awake mode. 
     In accordance with still yet another aspect of the present invention, a method of transmitting an SMS message by a base station in a wireless communication system is provided. The method includes, if there is a broadcast SMS message to be transmitted to at least two or more mobile stations, setting a value of a specific field in a paging message to a value indicating the broadcast SMS message is to be transmitted, if there is a unicast SMS message to be transmitted a specific mobile station, setting the value of the specific field to a value indicating that the unicast SMS message is to be transmitted, and if the value of the specific field is the value indicating that the unicast SMS message is to be transmitted, transmitting the paging message including a value indicating the specific mobile station. 
     In accordance with still yet another aspect of the present invention, a wireless communication system is provided. The system includes a base station for, if there is a broadcast SMS message to be transmitted, transmitting a paging message including a first field set to a value indicating that there is the broadcast SMS message to be transmitted, configuring a broadcast MAP Information Element (IE) including a broadcast transport Connection IDentifier (CID) indicating a channel over which transmit the broadcast SMS message, and information on a data burst allocation region, including the broadcast MAP IE in a MAP region, and transmitting the broadcast SMS message by using the channel over which to transmit the broadcast SMS message and a resource of the data burst allocation region indicated by the broadcast MAP IE, and a mobile station for receiving a paging message including a first field indicating whether or not there is a broadcast SMS message to be received from the base station, recognizing a broadcast transport CID indicating a channel over which to transmit the broadcast SMS message if the first field is set to a value indicating that the broadcast SMS message is to be received, and a data burst allocation region by decoding a broadcast MAP IE, and receiving the broadcast SMS message, transmitted using a resource of the data burst allocation region, through the channel over which to transmit the broadcast SMS message. 
     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 
       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: 
         FIG. 1  is a signal flowchart illustrating an operation of providing SMS in a conventional CDMA communication system; 
         FIG. 2  is a view illustrating an operation of a mobile terminal in response to a receipt of a paging message in accordance with an exemplary embodiment of the present invention; 
         FIG. 3  is a view illustrating a frame structure indicating a broadcast burst carrying an SMS message in accordance with an exemplary embodiment of the present invention; 
         FIG. 4  is a flowchart illustrating an operation of receiving an SMS message by a mobile station in accordance with an exemplary embodiment of the present invention; and 
         FIG. 5  is a timing chart illustrating a procedure of providing broadcast SMS in accordance with an exemplary embodiment of the present invention. 
     
    
    
     Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the present 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. Also, descriptions of well-known functions and configurations are omitted for clarity and conciseness. 
     Exemplary embodiments of the present invention provide a system and method for providing SMS in a wireless communication system using orthogonal frequencies. 
     According to exemplary embodiments of the present invention, SMS may be provided to a specific mobile station that is in an idle mode, or may also be provided to some or all mobile stations, as in the case of emergency SMS. 
       FIG. 2  illustrates an operation of a mobile terminal in response to a receipt of a paging message according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 2 , the reference numeral “ 200 ” represents a conventional operation of a mobile station that is in an idle mode. The idle mode mobile station can periodically receive a mobile paging advertisement (hereinafter referred to as “MOB_PAG_ADV”) message in a listening interval. 
     The reference numeral “ 210 ” represents an operation in which the idle mode mobile station receives a MOB_PAG-ADV message, transitions to an awake mode if the received MOB_PAG-ADV message includes a Medium Access Control (MAC) address corresponding to the mobile station, and then receives traffic. 
     The reference numeral “ 220 ” represents an operation in which the idle mode mobile station receives a MOB_PAG-ADV message, transitions to an awake mode if the received MOB_PAG-ADV message includes a MAC address corresponding to the mobile station, receives a unicast SMS message, and then transitions to an idle mode again. 
     The reference numeral “ 230 ” represents an operation in which the idle mode mobile terminal receives a MOB_PAG-ADV message, and then receives a broadcast SMS message according to a broadcast SMS message receipt indication of the MOB_PAG-ADV message. 
     An exemplary embodiment of the present invention proposes a new operation related to the operations represented by the reference numerals “ 220 ” and “ 230 ”. That is, the exemplary embodiment of the present invention is intended to introduce a system and method for providing SMS, which is not yet defined in a wireless communication system using divided orthogonal frequencies. 
     The above-mentioned MOB_PAG-ADV message is used to awake at least one mobile station that is in an idle mode. In an exemplary embodiment of the present invention, a mobile station that has received a MOB_PAG-ADV message from a base station confirms an SMS message in an awake mode, and then transitions to an idle mode again, or confirms an SMS message in an idle mode. 
     For this end, an exemplary embodiment of the present invention newly proposes a MOB_PAG-ADV message having a format as presented below in Table 1. 
     
       
         
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Syntax 
                 Size 
                 Notes 
               
               
                   
               
             
             
               
                 MOB_PAG-ADV_Message_format( ) { 
                 — 
                   
               
               
                 Management Message Type = 62 
                 8 bits 
               
               
                 Num_Paging_Group_Ids 
                 8 bits 
               
               
                 For(i=0;i&lt;Num_Paging_group_IDs;i++) { 
                 — 
               
               
                 Paging Group ID 
                 16 bits  
               
               
                 } 
                 — 
               
               
                 Broadcast SMS Indication 
                 1 bit 
                 Indication to SMS 
               
               
                 If(Broadcast SMS Indication = 1) { 
                 — 
               
               
                 Action Code 
                 3 bits 
                 0b000 = No Action 
               
               
                   
                   
                 Required 
               
               
                   
                   
                 0b001 = Perform Ranging to 
               
               
                   
                   
                 established location and 
               
               
                   
                   
                 acknowledge message 
               
               
                   
                   
                 0b010 = Enter network 
               
               
                   
                   
                 0b011 = Unicast SMS 
               
               
                   
                   
                 0b100 = Broadcast SMS 
               
               
                 Reserved 
                 5 bits 
               
               
                 } 
                 — 
               
               
                 else { 
                 — 
               
               
                 Num_MACs 
                 8 bits 
               
               
                 For(j=0;j&lt;Num_MACs;j++) { 
                 — 
               
               
                 MS MAC Address Hash 
                 24 bits  
               
               
                 Action Code 
                 3 bits 
               
               
                 Reserved 
                 5 bits 
               
               
                 } 
                 — 
               
               
                 } 
                 — 
               
               
                 Padding 
                 Variable 
               
               
                 TLV Encoded Information 
                 Variable 
               
               
                 } 
                 — 
               
               
                   
               
             
          
         
       
     
     The MOB_PAG-ADV message newly proposed in the exemplary embodiment of the present invention includes a 1-bit broadcast SMS indication field and a 3-bit action code field. 
     On receiving the MOB_PAG-ADV message, a mobile station determines whether the broadcast SMS indication field has a value of zero (0) or one (1). 
     If the broadcast SMS indication field has a value of zero (0), the mobile station determines if the MOB_PAG-ADV message includes a MAC address corresponding to the mobile station. If the message includes the mobile station&#39;s MAC address, the mobile station performs an operation corresponding to the value of the action code field. If the action code field has a value of 0b011, the mobile station transitions to an awake mode, receives an SMS message, and then transitions to an idle mode again. 
     If the broadcast SMS indication field has a value of one (1), the mobile station recognizes that there is an SMS message to be received by all mobile stations. Thus, the mobile station waits for receipt of the SMS message in a listening interval of an idle mode state. After the mobile station receives the SMS message, it maintains a normal paging cycle. 
     As described above, a unicast SMS message may be provided to a specific mobile station when the broadcast SMS indication field of a MOB_PAG-ADV message has a value of zero (0), and a broadcast SMS message may be provided to a plurality of mobile stations when the broadcast SMS indication field has a value of one (1). 
     For a broadcast SMS message to be received by some or all mobile stations, the mobile stations must receive the broadcast SMS message irrespective of which mode they are in. That is, the mobile stations must be able to receive the broadcast SMS message in an idle mode, as well as an awake mode. For this end, the exemplary embodiment of present invention newly defines a Broadcast_MAP_IE for a broadcast SMS message. Also, the exemplary embodiment of the present invention newly defines a broadcast transport Connection IDentifier (CID) indicating a channel for broadcast SMS message transmission. The broadcast transport CID is a unique identifier needed to broadcast the same data burst to all mobile stations within a base station. Tables 2 and 3 as given below show a CID list to which the broadcast transport CID is added and the Broadcast_MAP_IE respectively. In table 2, contents to be entered in the description field follow the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard documents, of which is incorporated by reference. 
     
       
         
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 CID 
                 Value 
                 Description 
               
               
                   
               
             
             
               
                 Ranging CID 
                 0x0000 
                   
               
               
                 Basic CID 
                 0x0001 − m 
               
               
                 Primary management 
                 M + 1 − 2m 
               
               
                 Transport CISs, Secondary Mgt CIDs 
                 2m + 1 − FE9E 
               
               
                 Broadcast transport CID 
                 FE9F 
               
               
                 Multicast CIDs 
                 0xFEA0-0xFEFE 
               
               
                 AAA initial ranging CID 
                 0xFEFE 
               
               
                 Multicast polling CIDs 
                 0xFF00-0xFFF9 
               
               
                 Normal mode Multicast CID 
                 0xFFFA 
               
               
                 Sleep mode multicast CID 
                 0xFFFB 
               
               
                 Idle mode multicast CID 
                 0xFFFC 
               
               
                 Fragmentable broadcast CID 
                 0xFFFD 
               
               
                 Padding CID 
                 0xFFFE 
               
               
                 Broadcast CID 
                 0xFFFF 
               
               
                   
               
             
          
         
       
     
     
       
         
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Syntax 
                 Size 
                 Notes 
               
               
                   
                   
               
             
             
               
                   
                 Broadcast_MAP_IE( ) { 
                   
                   
               
               
                   
                 DIUC 
                 4 bits 
               
               
                   
                 Broadcast Transport CID 
                 16 bits  
                 FE9F 
               
               
                   
                 OFDMA Symbol offset 
                 8 bits 
               
               
                   
                 Subchannel offset 
                 6 bits 
               
               
                   
                 Boosting 
                 3 bits 
               
               
                   
                 NO. OFDMA Symbols 
                 7 bits 
               
               
                   
                 NO. Subchannels 
                 6 bits 
               
               
                   
                 Repetition Coding Indication 
                 2 bits 
               
               
                   
                 } 
               
               
                   
                   
               
             
          
         
       
     
     For example, when a mobile station receive a MOB_PAG-ADV message, and the broadcast SMS indication field of the received MOB_PAG-ADV message has a value of one (1), the mobile station receives a Broadcast_MAP_IE as presented in Table 3, and then confirms a broadcast transport CID included in the Broadcast_MAP_IE. A value used as the broadcast transport CID is known in advance by the mobile station, as given in Table 2. Thus, the mobile station recognizes the existence of traffic for broadcast, that is, a broadcast SMS message, by confirming the broadcast transport CID, and decodes a corresponding data burst region. Here, the traffic for broadcast may be SMS traffic. The mobile station can receive SMS by decoding the corresponding data burst region. 
     An awake mode mobile terminal can receive a Broadcast_MAP_IE without receiving a MOB_PAG-ADV message. Therefore, the awake mode mobile station may receive SMS at any time, and an idle mode mobile station may receive SMS after transitioning to an awake mode through a paging procedure. 
       FIG. 3  illustrates a frame structure indicating a broadcast burst carrying an SMS message. 
     Referring to  FIG. 3 , a Broadcast_MAP_IE  300  having a format as presented above in Table 3 is located in the downlink MAP (DL-MAP) region of the frame, and the Broadcast_MAP_IE indicates a data burst region  310  carrying a broadcast SMS message. 
       FIG. 4  illustrates an operation of receiving an SMS message by a mobile station according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 4 , the mobile station receives a MOB_PAG-ADV message from a base station in step  402 , and then proceeds to step  404 . The mobile station identifies the value of the broadcast SMS indication field of the MOB_PAG-ADV message in step  404 . When the broadcast SMS indication field has a value of one (1), that is, when there is a broadcast SMS message to be received by the mobile station, the mobile station proceeds to step  406 . The mobile station receives the broadcast SMS message in a listening interval in step  406 . On receiving the broadcast SMS message, the mobile station returns to an unavailable listening interval and maintains a normal paging cycle. 
     In contrast, when the broadcast SMS indication field has a value of zero (0), that is, when there is no broadcast SMS message, the mobile station proceeds to step  408  and determines if its MAC address is included in the MOB_PAG-ADV message. When the mobile station&#39;s MAC address is included in the MOB_PAG-ADV message, the mobile station proceeds to step  410  and determines if the action code field of the MOB_PAG-ADV message has a value of 0b011. The action code field value of 0b011 indicates that there is a unicast message to be received by the mobile station. When the action code field has a value of 0b011, the mobile station transitions to an awake mode in step  414 , and then proceeds to step  416 . The mobile station receives the unicast SMS message in step  416 , and then proceeds to step  418 . The mobile station transitions to an idle mode in step  418 . However, when the action code field does not have a value of 0b011 in step  410 , the mobile station proceeds to step  412 , and performs an operation corresponding to a relevant action field value in step  412 . 
     An operation of receiving a unicast SMS message by an awake mode mobile station may be the same as a conventional operation of receiving data. 
       FIG. 5  illustrates a procedure of providing SMS according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 5 , if a broadcast message to be transmitted is generated, a gateway  520  informs a base station  510  of a need for paging in step  501 . The gateway  520  transmits the broadcast message to the base station  510  in step  503 . 
     The base station  510  transmits a MOB_PAG-ADV message, the broadcast SMS indication field of which is set to one (1), to a mobile station  500  in step  505 . The base station  510  transmits the broadcast message, that is, a broadcast SMS message, to the mobile station  500  in step  507 . Steps  505  and  507  may be repeated in steps  509  and  511 . 
     The mobile station  500  decodes a DL-MAP message in step  513 , and then decodes a data burst included in a data burst region, the location of which is discovered by decoding the DL-MAP message in step  515 . The number of mobile stations receiving the broadcast message may be at least one. 
     As described above, the present invention defines a procedure of receiving an SMS message by a mobile station in a wireless communication system using orthogonal frequencies, so that users can be provided with SMS, and service providers can create profit. 
     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.