Patent Application
20100302095
1. Field of the Invention
The present invention relates to global positioning systems (GPS), and more particularly to a system for sharing GPS protocol data and a method thereof, capable of sharing the GPS protocol data among a plurality of application devices or application programs.
2. Related Art
The development and applications of Global Positioning System (GPS) is initiated by the U.S. Department of Defense, and the GPS technology was only used in military at early time Recently, GPS is widely applied to commercial purpose. A GPS system includes 24 GPS satellites in the outer space, 1 master control station, 3 data upload stations, 5 monitor stations, and GPS receivers at subscriber ends.
The most popular one of the commercial GPS receivers is the GPS receiver used for vehicle navigation. In general, the GPS receiver transmits GPS protocol data through serial ports (a.k.a. COM Ports), and when the GPS protocol data is transferred during communication, a most commonly used communication protocol is national marine electronics association (NMEA) (for example, NMEA-0183 protocol). An application device of the subscriber end is, for example, a personal digital assistant (PDA) or a navigation device, the application device is connected to the GPS receiver through a serial port, so as to obtain the GPS protocol data (for example, NMEA Data or SiRF Binary Data), and then the application device obtains geographic data of a position of the GPS receiver through parsing the GPS protocol data. However, being limited by the serial port, the GPS protocol data transmitted by the GPS receiver cannot be utilized by two or more application devices or application programs.
Recently, software solving the problem by establishing virtual serial ports has been developed. Similar to a software pipes, the GPS protocol data is directly guided in and out these virtual serial ports, such that different application devices or application programs may obtain the GPS protocol data by being connected to different virtual serial ports. However, in the method, GPS commands sent by the application devices or the application programs of the subscriber end are directly transmitted to the GPS receiver without being appropriately processed, such that other application devices or application programs sharing the software pipe are easily disordered.
In the conventional art, the virtual COM port (serial port) is used to receive GPS protocol data, but is only limited to a COM port format capable of be accepted by a geographic information system (GIS) map engine module. For a subscriber end, only one GIS map engine module may use the satellite coordinate data, and the satellite coordinate data cannot be utilized by two or more application devices or application programs. In addition, in the prior art, a service of converting the GPS protocol data having different formats is not provided. For example, if the two application devices or application programs respectively require the GPS protocol data having different formats, such as NMEA and SiRF Binary, in the prior art, the application devices or the application programs respectively using the GPS protocol data having the two different formats cannot be served.
The present invention is directed to a system for sharing GPS protocol data, which is used to provide the GPS protocol data to a plurality of clients (such as a plurality of application device or application programs) for use.
In order to achieve the above object, the system for sharing the GPS protocol data according to a preferred embodiment of the present invention includes a GPS receiver, a GPS protocol data server, a service application program, and a virtual serial port driver.
The GPS receiver receives raw GPS protocol data from a satellite.
The GPS protocol data server has a physical serial port for establishing a communication with the GPS receiver to obtain the raw GPS protocol data (NMEA, SiRF Binary, Other . . . ), and has a communication interface.
The service application program is executed on the GPS protocol data server, and includes a GPS protocol data parsing procedure for parsing the raw GPS protocol data, and a transfer control protocol/Internet protocol (TCP/IP) based multi-thread communication procedure. The service application program is for providing a TCP/IP based communication service through the communication interface, so as to serve service requests from the clients and provide the parsed GPS protocol data.
The virtual serial port driver provides a plurality of virtual serial ports for a plurality of clients to establish communication connections. Each virtual serial port communicates with the service application program of the GPS protocol data, so the plurality of clients respectively communicate with the service application program through the virtual serial ports, thus obtaining the GPS protocol data provided by the service application program.
The present invention is further directed to a system for sharing GPS protocol data, for providing the GPS protocol data to a plurality of clients for use, and providing a format converting service. The system accepts service requests from the plurality of clients, so as to provide the GPS protocol data having different formats.
In order to achieve the above object, the system for sharing the GPS protocol data according to the present invention further has a GPS protocol data converting procedure, which is capable of accepting service requests from a plurality of clients, and converting a certain GPS protocol data format to another GPS protocol data format.
The present invention further provides a method for sharing GPS protocol data, which includes the following steps.
In step A, raw GPS protocol data from a satellite is obtained.
In step B, a plurality of virtual serial ports is provided for being connected to a plurality of clients, and service requests from the clients are obtained.
In step C, a service application program is executed to parse the raw GPS protocol data, so as to provide a service of resolving the GPS protocol data.
In step D, the service requests of parsing the GPS protocol data from the clients are sent to the service application program.
In step E, the service application program responds to the service requests from the clients through a TCP/IP based multi-thread communication path.
The advantages of the present invention are:
1. The problem that one GPS receiver may only be started and utilized by a single application device or application program is solved. Through the technique of the present invention, the GPS receiver may be started and simultaneously utilized by a plurality of application devices or application programs intending to read the GPS protocol signal data.
2. The GPS protocol data server is simulated as a plurality of real GPS receivers through software, but has a stronger function. The common GPS receiver may only output the GPS protocol data format of one communication protocol at the same time, however, through the GPS protocol data converting procedure of the present invention, the raw GPS protocol data is converted to various GPS protocol data having different formats through processing by the software.
3. A certain application device or application program of the client may be served. According to the service requests from the application device or the application program to the service application program, the setting of reading the GPS protocol data of the application device or the application program, such as the format of the output GPS protocol data, the GPS protocol, or transfer rate, may be modified. The service application program of the present invention provides the services for the clients by utilizing the TCP/IP based multi-thread communication procedure, such that other application devices or application programs of the client are not interfered.
4. The GPS protocol data of the GPS receiver may be read by a remote end (non-Local end) application device or application program. The service application program of the present invention provides the services for the clients by utilizing the TCP/IP based multi-thread communication procedure, so that the distal end application device or application program may access thereto.
The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein:
Referring to
The GPS receiver 10 receives raw GPS protocol data from a satellite.
The GPS protocol data server 20 has a physical serial port 21 (physical serial port/physical COM Port) for establishing a communication with the GPS receiver 10 to obtain the raw GPS protocol data, and has a communication interface 22 for communicating with the clients. Preferably, the communication interface may be a network interface card (NIC) or a wireless local area network (WLAN) card.
The service application program 30 is executed on the GPS protocol data server 20, and includes a GPS protocol data parsing procedure 31 and a TCP/IP based multi-thread communication procedure 32. The GPS protocol parsing procedure 31 is provided for parsing the raw GPS protocol data of different communication protocols (such as NMEA, SiRF Binary . . . ), and is used to parse the received raw GPS protocol data to the data including one or any combination of longitude, latitude, height, speed, and time. The service application program 30 provides a TCP/IP based communication service through the communication interface 22, so as to serve service requests from the clients, for example, to provide the parsed GPS protocol data or the raw GPS protocol data, or a transfer rate of the GPS protocol data.
The virtual serial port driver 40 simulates a plurality of virtual serial ports 41A, 41B and 41N. Each virtual serial port 41A, 41B and 41N communicates with the service application program 30 through the TCP/IP protocol, so the application devices or the application programs 50 of the clients may respectively establish communication connections with the virtual serial ports 41A, 41B, and 41N, so as to obtain the GPS protocol data or the raw GPS protocol data parsed by the service application program 30 through the virtual serial ports 41A, 41B, and 41N. In addition, the application devices or the application programs 50 of the clients may send service requests or operating instructions to the service application program 30 through the virtual serial ports 41A, 41B, and 41N.
Referring to
In step A, raw GPS protocol data from a satellite is obtained.
In step B, a plurality of virtual serial ports is provided for being connected to a plurality of clients, and service requests from the clients are obtained.
In step C, a service application program is executed to parse the raw GPS protocol data, so as to provide a service of parsing the GPS protocol data.
In step D, the service requests of parsing the GPS protocol data from the clients are sent to the service application program.
In step E, the service application program responds to the service requests from the clients through a TCP/IP based multi-thread communication path.
The service application program 30 of the present invention provides the service for the clients by utilizing the TCP/IP based multi-thread communication procedure 32, such that the service requests or the operating instructions from the plurality of clients are not interfered with each other. In a preferred embodiment according to the prevent invention, the GPS protocol data server 20 may be implemented as a server, a desktop computer, a laptop computer, or other computer devices. The virtual serial port driver 40 may be directly executed on the GPS protocol data server 20 (as shown in
Referring to
Referring to
