Abstract:
A global positioning system using Bluetooth technology, including: a first Bluetooth master that receives satellite orbit information; a Bluetooth slave that communicates with the first Bluetooth master in a Bluetooth protocol; and a second Bluetooth master that transmits an inquiry code for communication with the Bluetooth slave in the Bluetooth protocol. The second Bluetooth master provides positioning information by requesting the satellite orbit information from the first Bluetooth master through the Bluetooth slave and transmitting the satellite orbit information to the second Bluetooth master through the Bluetooth slave.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2008-0005735 filed on Jan. 18, 2008, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
     Field of the Invention 
       [0002]    The present general inventive concept disclosed herein relates to global positioning systems, and more particularly, to a driving method of the global positioning system to obtain satellite orbit information by Bluetooth technology. 
         [0003]    In recent years, with increasing expectations for location-based services (LBS), global positioning systems (GPS) are being regarded as the typical systems capable of estimating locations by themselves. 
         [0004]    Nowadays products basically equipped with GPS chipsets are widely employed in portable electronic apparatuses such as mobile phones or even cameras, navigation-specific terminals as well. 
         [0005]    A GPS calculates its current location by receiving a signal from 24 satellites which are positioned up in the sky over 20,200 km for position estimation. 
         [0006]    A basic theory of position estimation is to calculate a pseudo-range between a satellite and a GPS receiver by means of a gap between a transmission time of the satellite and a reception time of the GPS receiver. Pseudo-ranges between the GPS receiver and more than three satellites are used for estimating a current position of the GPS receiver. 
         [0007]    To calculate a current position by such a manner, it is necessary to find out a correct location of the satellite and to be operable in synchronization. In the meantime, the satellites load data, such as their orbit conditions and time errors, on codes that are provided for calibrating distances between the GPS receiver and them so as to transmit the positioning information. 
       SUMMARY 
       [0008]    The present general inventive concept provides fast positioning information by means of satellite orbit information transmitted from a Bluetooth master including a satellite receiver (or a GPS receiver). 
         [0009]    The present general inventive concept also provides positioning information by means of satellite orbit information transmitted from a Bluetooth master including a satellite receiver, even without a satellite receiver in a GPS. 
         [0010]    Additional features and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept. 
         [0011]    Embodiments of the general inventive concept can be achieved by providing a global positioning system using Bluetooth technology, including: a first Bluetooth master to receive satellite orbit information; a Bluetooth slave to communicate with the first Bluetooth master in a Bluetooth protocol; and a second Bluetooth master to transmit an inquiry code to communicate with the Bluetooth slave in the Bluetooth protocol. The second Bluetooth master can provide positioning information by requesting the satellite orbit information from the first Bluetooth master through the Bluetooth slave and transmitting the satellite orbit information to the second Bluetooth master through the Bluetooth slave. 
         [0012]    In an embodiment, the second Bluetooth master is used to search for the Bluetooth slave, which is capable of receiving a satellite signal, by means of the inquiry code. 
         [0013]    In an embodiment, the Bluetooth slave is already connected to the first Bluetooth master before communicating with the second Bluetooth master. 
         [0014]    In an embodiment, the first Bluetooth master comprises a satellite receiver. 
         [0015]    In an embodiment, the first Bluetooth master receives the satellite orbit information through the satellite receiver. 
         [0016]    In an embodiment, the satellite orbit information includes information received in 4 hours. 
         [0017]    In an embodiment, the second Bluetooth master comprises a satellite receiver. 
         [0018]    In an embodiment, the satellite receiver operated in cold and hot start modes. 
         [0019]    In an embodiment, the satellite receiver operates in the hot start mode by means of the satellite orbit information received from the first Bluetooth master. 
         [0020]    In an embodiment, the Bluetooth protocol includes Bluetooth 2.1. 
         [0021]    Embodiments of the general inventive concept can also be achieved by providing a method of operating a global positioning system (GPS), including: requesting readily available satellite orbit information through a Bluetooth slave upon powering up of a Bluetooth master; and accessing the readily available satellite orbit information from a second Bluetooth master by the Bluetooth slave and transmitting the accessed readily available satellite orbit information to the powering up Bluetooth master. 
         [0022]    A GPS according to an embodiment of the present general inventive concept operates in the hot start mode by means of satellite orbit information transmitted from a Bluetooth master including the satellite receiver. 
         [0023]    The present general inventive concept provides positioning information by means of satellite orbit information transmitted from a Bluetooth master including the satellite receiver, even without a satellite receiver in the GPS. 
         [0024]    A further understanding of the nature and advantages of the present general inventive concept herein may be realized by reference to the remaining portions of the specification and the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    These and/or other aspects and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0026]      FIG. 1  is a block diagram illustrating a general configuration of interconnection between a Bluetooth master and a Bluetooth slave; 
           [0027]      FIG. 2  is a block diagram of a global positioning system using Bluetooth technology according to the present general inventive concept; 
           [0028]      FIG. 3  is a schematic diagram of the DIAC inquiry scheme shown in  FIG. 2 ; and 
           [0029]      FIG. 4  is a schematic diagram illustrating an embodiment of the present general inventive concept in conjunction with  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0030]    Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures. 
         [0031]      FIG. 1  is a block diagram illustrating a general configuration of interconnection between a Bluetooth master and a Bluetooth slave. Referring to  FIG. 1 , a Bluetooth master  1  accesses a Bluetooth slave  2  through two stages, i.e., an inquiry stage of S 01 ˜S 04  and a paging stage of S 05 ˜S 09 . In other words, interconnection between the Bluetooth master  1  and the Bluetooth slave  2  is accomplished by the inquiry stage S 01 ˜S 04  to search for the Bluetooth slave  2  by the Bluetooth master  1 , and the paging stage S 05 ˜S 09  to transmit an ID packet, including an Bluetooth address, to the Bluetooth master  1  from the Bluetooth slave  2 . 
         [0032]    First, in the inquiry stage, the Bluetooth master  1  searches around the area for the Bluetooth slave  2  (operation S 01 ). If there is the Bluetooth slave  2  around the Bluetooth master  1 , the Bluetooth slave  2  responds to the Bluetooth master  1  for the inquiry (operation S 02 ). Unless there is the Bluetooth slave  2  around the Bluetooth master  1 , the Bluetooth master outputs a signal searching for the Bluetooth slave  2 . Then, the Bluetooth master  1  transmits a page signal to the Bluetooth slave  2  to request a Bluetooth address including a clock of the Bluetooth slave  2  (operation S 03 ). The Bluetooth slave  2  transmits a packet, which includes the Bluetooth address, to the Bluetooth master  1  as a paging response signal (operation S 04 ). 
         [0033]    Next, in the paging stage, the Bluetooth master  1  and the Bluetooth slave  2  exchange their features with each other (operation S 05 ). In addition, the Bluetooth master  1  requests connection from the Bluetooth slave  2  (operation S 06 ). The Bluetooth slave  2  accepts the request for connection with the Bluetooth master  1  (operation S 07 ). 
         [0034]    Then, the Bluetooth master  1  and the Bluetooth slave  2  conduct the operation S 08  of pairing and authentication, which makes them exempt from a later authentication requirement once they have been successfully authorized for the first interconnection. Thus, the connection setup operation with the Bluetooth master  1  and the Bluetooth slave  2  is terminated (operation S 09 ). 
         [0035]    Generally, a GPS using the Bluetooth technology does not receive satellite orbit information until completing the connection setup operation by entirely conducting the inquiry and paging stages between the Bluetooth master  1  and the Bluetooth slave  2 . For that reason, such a GPS by the Bluetooth technology takes much time in completing the connection between the Bluetooth master and the Bluetooth slave. 
         [0036]    A GPS generally operates in both cold and hot start modes. The cold start mode refers to a beginning mode to receive new satellite orbit information from a satellite when the GPS operates for the first time or restarts after 4 hours since a termination. In the cold start mode, it takes at least 30 seconds to download data, which are required to estimate a current position, from the satellite. In practice, referring to specification data provided by a manufacturer that produces GPS receiver chipsets, it can be seen that a time for first calculating a current position of a terminal from a satellite (or positioning) signal, i.e., a time-to-first-fix (TIFF), takes in the range of 35˜50 seconds. 
         [0037]    The hot start mode refers to a mode to shorten a TIFF by means of using the previous satellite orbit information when the GPS restarts. The hot start mode is helpful to shorten the TIFF within several seconds, but is limited in that it is available only when the GPS restarts within 4 hours from the prior termination. 
         [0038]    Now a detailed description will be provided regarding a method of receiving new satellite orbit information through the inquiry stage in conjunction with  FIGS. 2 and 3 . 
         [0039]      FIG. 2  is a block diagram of a GPS using the Bluetooth technology according to an embodiment of the present general inventive concept. 
         [0040]    Referring to  FIG. 2 , the Bluetooth-based GPS  100  includes a first Bluetooth master  21 , a Bluetooth slave  22 , and a second Bluetooth master  23 . 
         [0041]    The second Bluetooth master  23  includes a satellite receiver (or GPS receiver; not shown), which receives new satellite orbit information through the satellite receiver. Thus, the second Bluetooth master  23  has satellite orbit information that has been received within the past 4 hours. Here, the satellite receiver usually indicates an apparatus including an antenna to receive a satellite signal (positioning or GPS signal) and a chipset to process the satellite signal transferred from the antenna. Thereby, the first Bluetooth master  21  conducts the hot start mode by means of satellite orbit information that has been received within the past 4 hours from the second Bluetooth master  23  through the Bluetooth slave  22 . 
         [0042]    The second Bluetooth master  23  and the Bluetooth slave  22  are completely set up in connection by an operation S 21 . 
         [0043]    The first Bluetooth master  21  transmits an ID packet to the Bluetooth slave  22 , which is around it, by means of a dedicated inquiry access code (DIAC). 
         [0044]    DIAC refers to an access code used to inquire a Bluetooth slave, which has a specific function, by a Bluetooth master.  FIG. 3  shows a detailed embodiment of DIAC inquiry scheme. 
         [0045]    A first Bluetooth master  31  exemplified in  FIG. 3  is a personal digital assistant (PDA) phone and a second Bluetooth master  36  is a Bluetooth phone embedding a GPS receiver therein. As shown in  FIG. 3 , a first Bluetooth slave  32  is a digital camera operable in the Bluetooth function, a second Bluetooth slave  33  is a printer operable in the Bluetooth function, a third Bluetooth slave  34  is a notebook computer operable in the Bluetooth function, and a fourth Bluetooth slave  35  is a headset operable in the Bluetooth function. As shown in  FIG. 3 , the second Bluetooth master  36  has been already connected to the fourth Bluetooth slave  35  by way of a Bluetooth protocol. 
         [0046]    Referring to  FIG. 3 , the first Bluetooth master  31  transmits a DIAC to the first through fourth Bluetooth slaves  32 ˜ 35  that are placed around an area thereof in order to search for a Bluetooth slave capable of receiving a GPS signal. Then, the fourth Bluetooth slave  35  transmits a response of the DIAC to the first Bluetooth master  31 . 
         [0047]    Thereby, the first Bluetooth master  31  becomes connected to the fourth Bluetooth slave  35 , which is connected to the second Bluetooth master  36  that is capable of receiving a satellite signal, in the inquiry stage. Thus, the first Bluetooth master  31  receives satellite orbit information from the second Bluetooth master  36  by way of the fourth Bluetooth slave  35 . 
         [0048]    Returning to  FIG. 2 , the first Bluetooth master  21  requests satellite orbit information from the second Bluetooth master  23  through the Bluetooth slave  22  (operation S 23 ). The second Bluetooth master  23  transmits the requested satellite orbit information to the Bluetooth slave  22  (operation S 24 ). 
         [0049]    The Bluetooth slave  22  transmits a frequency hop selection (FHS) packet to the first Bluetooth master  21  (operation S 25 ). The FHS packet is provided to set a frequency for Bluetooth communication between the first Bluetooth master  21  and the Bluetooth slave  22 . 
         [0050]    The Bluetooth slave  22  transmits an extended inquiry response (EIR) packet to the first Bluetooth master  21 . The EIR packet is generic information transferred to a Bluetooth master from a Bluetooth slave in the inquiry stage, which was proposed by the Bluetooth 2.1 protocol. 
         [0051]    If the first Bluetooth master  21  embeds a satellite receiver (or GPS receiver), it operates in the hot start mode by means of the satellite orbit information transmitted from the second Bluetooth master  23 . 
         [0052]    Even though the first Bluetooth master  21  do not have a satellite receiver, it is able to calculate positioning information from the satellite orbit information transmitted from the second Bluetooth master  23 . 
         [0053]      FIG. 4  is a schematic diagram illustrating an embodiment of the present general inventive concept in conjunction with  FIG. 2 . 
         [0054]    Referring to  FIG. 4 , the Bluetooth phone  23  as the second Bluetooth master and the headset  22  as the Bluetooth slave are complete therebetween in a connection setup (operation S 41 ). The PDA phone  21  as the first Bluetooth master transmits an ID packet to the headset  22 , which is located in an area around the PDA phone  21 , by means of a DIAC (operation S 42 ). The PDA phone  21  requests satellite orbit information from the Bluetooth phone  23  through the headset  22  (operation S 42 ). Then, the Bluetooth phone  23  transmits the satellite orbit information to the headset  22  (operation S 44 ). The headset  22  transmits an FHS packet to the PDA phone  21  (operation S 45 ). Finally, the headset  22  transmits an EIR packet to the PDA phone  21 . 
         [0055]    Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.