Abstract:
There is disclosed a method of providing location services in a worldwide interoperability for microwave access (WiMAX) network. The method includes: at a serving base station of a mobile station, receiving a location service request of the mobile station; transmitting a scanning interval allocation response message (MOB-SCN-RSP) defined in a WiMAX wireless standard in response to the location service request; receiving a scanning result report message (MOB-SCN-REP) defined in the WiMAX wireless standard and transmitted by the mobile station in response to the scanning interval allocation response message (MOB-SCN-RSP); and transmitting a location service response upon receiving the scanning result report message (MOB-SCN-REP).

Description:
[0001]    The present application claims priority from Korean Patent Application Nos. 10-2006-124954 (filed on Dec. 8, 2006) and 10-2007-112482 (filed on Nov. 6, 2007), the entire subject matters of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a method of providing location services in a mobile communication network, and more particularly to a method of providing location services by using messages defined in the Institute of Electrical and Electronic Engineers (IEEE) 802.16 standard in a worldwide interoperability for microwave access (WiMAX) network. 
         [0004]    2. Background of the Invention 
         [0005]    The 802.16 WiMAX technology is a next-generation wireless broadband communication technology providing wide-area outdoor services with more extended functions and coverage than Wi-Fi, which is a wireless communication technology providing indoor services around a hot spot. While the coverage of Wi-Fi (802.11b/g) is about 30 to 200 m and the transmission rate thereof is no more than 4 to 11 Mbps, the coverage of WiMAX can be extended up to 10 km and the available transmission rate thereof is 40 Mbps. This offers a substantial technical advantage. 
         [0006]    With the development of mobile communication systems and the increase in subscribers, locations services have been provided to inform the geographical location of a mobile communication terminal. The location services are useful when there is a need for emergency calls, tracking illegal users or logistics management. 
         [0007]    There has been no method, which provides location services in a WiMAX network proposed as a next-generation wireless broadband communication technology. Consequently, there is a need for an efficient method of providing location services. 
       SUMMARY OF THE INVENTION 
       [0008]    Thus, the present invention provides a method of providing location services by using messages defined in the WiMAX wireless standard (IEEE 802.16 standard) without any change in the messages. 
         [0009]    According to one embodiment of the present invention, there is provided a 
         [0010]    According to another embodiment of the present invention, there is provided a 
         [0011]    According to yet another embodiment of the present invention, there is provided a storage medium that stores computer-readable instructions for executing each of the methods described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic diagram showing the structure of a portable internet network, to which a portable internet-based wireless positioning in accordance with the present invention is applied; 
           [0013]      FIG. 2  shows a call flow for providing location services in accordance with one embodiment of the present invention; and 
           [0014]      FIG. 3  shows a call flow for providing location services in accordance with another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Hereinafter, a method of providing location services in a WiMAX network in accordance with embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
         [0016]      FIG. 1  shows a schematic structure of a WiMAX network  100 , to which a location service method in accordance with embodiments of the present invention is applied. 
         [0017]    A connectivity service network (CSN)  10  is a set of networks for providing a subscriber of a broadband wireless access system provided by an operator with the connectivity of application services, such as Internet and voice over Internet protocol (VoIP), the home agent (HA) of a mobile IP, authentication and charging functions, and location services. CSN  10  includes an AAA server (authentication, authorization and accounting server)  11 , a HA server  12 , a location service (LCS) server  13 , etc. Especially, the LCS server  13  serves as a positioning server (PS), which processes a location service request from an LCS client and calculates the position of a mobile station (MS). 
         [0018]    An access service network (ASN)  20  is a set of networks for providing a subscriber with broadband wireless access. ASN  20  includes a plurality of base stations (BSs)  21  and ASN gateways (ASN_GWs)  22 , and supports the functions such as connection setup between BSs  21  and MSs  30 , network discovery, network selection, radio resource management, etc. Each of BSs  21  performs the basic functions of BSs, including connecting MSs  30  and ASN_GWs  22  and converting a signal format to adapt the signal to wireless and wired links. Each of BSs  21  includes an LCS module. ASN_GWs  22  perform the functions of session mobility management and ASN radio resource management. 
         [0019]    BSs  21  and ASN_GWs  22  may be configured in one unit or in two independent units, and may be seen as one unit logically. 
         [0020]    In this embodiment, an operator IP network  40  is a private operator network that provides a mobile communication service. The operator IP network  40  can be connected to a public network  50 , which is managed and operated by a national telecommunications infrastructure provider. Alternatively, the operator IP network  40  may be a public network. 
         [0021]      FIG. 2  shows a call flow for providing location services. 
         [0022]    Hereinafter, one embodiment of the present invention will be described in detail with reference to  FIGS. 1 and 2 . 
         [0023]    In this embodiment, an LCS client requesting for a location set-vice may be any one of MSs  30  of subscribers, MS of a subscriber of another operator&#39;s network (not shown) to be connected to the operator IP network  40 , or a wired/wireless terminal receiving communication services via the public network  50 , e.g., a wired/wireless terminal of a police station. 
         [0024]    The LCS client makes a request  71  for the location service of a target MS 1 , which receives wireless services from BS 1  within ASN. The request  71  for the location service from the LCS client contains the identifier of the target MS 1 , e.g., a terminal address or telephone number information. At this time, BS 1  serves as a serving BS of the target MS 1 . 
         [0025]    The location service request  71  includes a location service request  71   a  to the LCS sever  13  from the LCS client, LCS client authentication  71   b  in the LCS server  13 , detection  71   c  of the location of the BS 1  in the LCS server  13 , and transmission of a location service request  71   d  to the BS 1  from the LCS server  13 . 
         [0026]    When the location service request  71  is received, the LCS module of BS 1  transmits a scanning interval allocation response (MOB-SCN-RSP) message  72  defined in the WiMAX wireless standard (IEEE 802.16 standard). The MOB-SCN-RSP message  72  contains a time interval allocation message for scanning peripheral BSs of the target MS 1 . The peripheral BSs are BSs except for the serving BS 1  among BSs, the downlink transmission of which can be demodulated by the target MS 1 . 
         [0027]    When the MOB-SCN-RSP message  72  is received, the target MS 1  scans the peripheral BSs during an allocated scanning interval and transmits a scanning result report (MOB-SCAN-REP) message  73  defined in the above-mentioned standard. The scanning result includes at least one of carrier to interface and noise ratio (CINR), receive signal strength indicator (RSSI), relative delay, and round trip delay (RTD) of each BS. 
         [0028]    When the MOB-SCAN-REP message  73  is received, the LCS module of BS 1  transmits a location service response  74  containing the scanning result. Upon receiving the location service response  74 , the LCS server  13  extracts the scanning result from the location service response  74  received from BS 1 . The LCS server then generates location information  75  of the target MS 1  by using the location information of BS 1  and the scanning result. The location of MS 1  is expressed in terms of latitude, longitude and altitude. The LCS server  13  provides the LCS client with the generated location information as a location service  76 . 
         [0029]      FIG. 3  shows a call flow, which describes a method of providing location services in accordance with another embodiment of the present invention. In this embodiment, MS serves as an LCS client. 
         [0030]    According to this embodiment, MS serves as an LCS client and makes a request  91  for its own location service to a serving BS. When a MS location service request  91  of the LCS client is received, an LCS module of the serving BS transmits a scanning interval allocation response (MOB-SCN-RSP) message  92  to MS. Then, MS transmits a scanning result report (MOB-SCN-REP) message  93  in response to the MOB-SCN-RSP message  92 . Based on the MOB-SCN-REP message  93 , the serving BS generates location information of MS and provides a location service  94 . 
         [0031]    As can be seen from the above-described embodiments, the present invention can provide location services by employing handover execution messages defined in the WiMAX wireless standard (IEEE 802.16 standard), i.e., the MOB-SCN-RSP message and the MOB-SCN-REP message, without any change. 
         [0032]    In another embodiment of the present invention, a storage medium can be employed to store computer-readable instructions for executing each of the above-described embodiments. 
         [0033]    According to the embodiments of the present invention, it is possible to provide a WiMAX location service without changing the configuration of mobile stations used in a WiMAX network by using messages defined in the existing WiMAX wireless standard (IEEE 802.16 standard) without any change. 
         [0034]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure.