Abstract:
The present invention relates to bidirectional radio paging systems and methods of paging without limiting destinations wherein at least one bidirectional radio pager and an uplink control device share a database containing information on a plurality of paging destinations and about response messages of various contents, and wherein a specified uplink data format is used for communication between base station equipment and the bidirectional radio pager, whereby the bidirectional radio pager comprises a first data generator for transforming destination information not previously registered in the database to a data format substantially in conformity with a data format associated with the uplink control device and a second data generator for generating radio transmission data containing a free destination flag as a message type, data related to the formatted unregistered destination information provided by the first data generator, and an index indicating an optional message content selected from the database.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to systems and methods for controlling receipt of a calling signal in a bidirectional radio paging system, and more particularly to systems and methods which provide destination non-limiting bidirectional radio paging operation. 
     2. Description of the Related Art 
     In the conventional bidirectional (calling/receiving) radio paging system, the bidirectional radio paging device (hereinafter referred to as “bidirectional radio pager”) has a database for storing limited information on paging parties and various types of response messages for responding to optional paging signals. The above response messages are to be received by paging (calling) parties, and the above paging parties&#39; information is the information as seen by paged (receiving) parties upon issuing a locate command. 
     The base station equipment of the bidirectional radio paging system shares the above database with the above bidirectional radio pager. Accordingly, the above paging party&#39;s information and the selected response message are not directly transmitted and received, but only corresponding indexes are exchanged. 
     However, it is not only inefficient in terms of utilization of the bidirectional radio pager but also inconvenient for users that the bidirectional radio pager can respond only to limited paging parties since the base station and the bidirectional radio pager share the above database. In other words, as compared to the diversity of paging parties, the information on paging parties to which the paged party can respond is limited, so that the users must take measures for making a response separately. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a bidirectional radio paging system and method capable of paging without limiting destinations, whereby the paged party can freely select and respond to the paging party without limiting the scope of the paging parties available for response. 
     In one aspect of the present invention, in a bidirectional radio paging system having at least one paging device and an uplink control device in which the at least one paging device and the uplink control device share a database containing information on a plurality of paging destinations and about response messages of various contents, the at least one paging device comprises: a first data generator for transforming destination information not previously registered in the database to a data format substantially in conformity with a data format associated with the uplink control device; and a second data generator for generating radio transmission data containing a free destination flag as a message type, data related to the formatted unregistered destination information provided by the first data generator, and an index indicating an optional message content selected from the database. 
     These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings, in which like reference symbols indicate the same or similar components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram illustrating a bidirectional radio paging device according to the present invention; 
     FIG. 2 is a block diagram illustrating the uplink code format of the radio pager according to the present invention; 
     FIG. 3 is a schematic diagram of a display panel for illustrating selection of free destination operation according to the present invention; 
     FIG. 4 is a flow chart illustrating the control of paging unlimited destination parties according to the present invention; and 
     FIG. 5 is a block diagram illustrating an example of one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a block diagram illustrating a bidirectional radio paging device according to the present invention is shown. Particularly, a control unit  13  is operatively coupled to a key inputter  10 , a receiving unit  11 , a decoder  12 , a transmission unit  14 , a memory unit  15 , a display unit  16  and an alarm unit  17 . The receiving unit  11  is also operatively coupled to an antenna  18  and the decoder  12 . The transmission unit  14  is also operatively coupled to an antenna  19 . 
     The key inputter  10  comprises keys for inputting user&#39;s paging information, and generating various control signals for operation of the bidirectional radio pager, for example, keys like a power on/off key, a channel scanning key for periodically performing scanning operation during channel scanning mode, and a read key for displaying messages received. 
     The receiving unit  11  amplifies weak RF signals of an assigned channel received from paging terminal equipment through the antenna  18 , converts the amplified signals into an original signal frequency band so as to be demodulated, and subjects the demodulated signals to waveform-shaping such that the signals are modified into digital data. 
     The decoder  12  decodes the digital data received from the RF receiving unit  11  to further transmit. In other words, the decoder  12  decodes the coded data received (usually data in BCH code) to original data, and detects preamble data, wordsync and its own frame data from the data in the form of POCSAG code for further transmitting. 
     The memory unit  15  is a memory for storing information on the bidirectional radio pager itself in which one or more EEPROM devices may preferably be employed. The information stored in the memory  15  includes cap codes consisting of inherent address data and frame data containing area information, reference channel frequencies for setting area channels, and service channel frequencies for receiving radio paging service in the area set by the above reference channel frequencies. Further, the above memory  15  stores a database which contains information on a limited number of optional paging parties intended for response (information about paging parties receiving response message from paged parties) and various types of response messages. 
     The control unit  13  analyzes information in the memory  15  to control the paging function of the bidirectional radio pager, thereby first performing the channel scanning function for initial operation when receiving the power on signal from the key inputter  10 . Namely, the above control unit  13  includes a first data generator for transforming free destination information (i.e., unrestricted or unlimited destination information which is not registered, that is, destination information not previously stored in the above database) into a pure data format conforming with the above uplink data format. The control unit  13  also includes a second data generator for generating radio transmission data containing the a free destination flag as a message type, data related to the above free destination information produced by first data generator, and an index indicating an optional message content selected from the above database. 
     The control unit  13  consecutively selects the reference channel frequencies retrieved from the above memory  15  and outputs the selected reference channel frequencies in specified periods so as to assign channels, thereby checking the presence of data from the assigned channel. 
     Thereupon, if data is received, the control unit  13  analyzes area information contained in the cap code to determine the area in which the bidirectional radio pager is currently located, and then outputs the service channel frequency corresponding to the area so as to analyze the frame data received from the assigned service channel, thereby controlling the overall function of the bidirectional radio pager. 
     The transmission unit  14  assigns the channel and transmitted data depending upon destination and selected messages from the above control unit  13 . 
     The display unit  16  displays various types of status and messages generated and received during radio paging services under the control of the control unit  13 . For example, the display unit  16  may be an LCD panel. The alarm unit  17  generates an alarm signal when receiving messages under the control of the control unit  13 . The above alarm unit  17  comprises an alarm sounding device and a vibrator for generating a vibration signal. 
     When power is first turned on, or when the bidirectional radio pager is moved to another area, the bidirectional radio pager must be able to analyze its regional location and assign the service channel frequency corresponding to the area. For convenience sake, the above state is called the initial operating state which is assumed to be initiated by turning the power switch on. When the initial operating state is initiated, the above control unit  13  reads the information in the memory  15  storing the cap code of the receiver, the reference channel frequency and the service channel frequency, etc. 
     Referring to FIG. 2, the uplink code encodes the data of 36 bits into BCH(63,36,5) code so as to be expanded to 63 bits, and one bit is added thereto to make 64 bits, which is then divided into data words A and B, each of 32 bits respectively. A reference bit ( 0 ) is added to the front of each 32 bit data word, in order to adopt the phase standard for DBPSK (Differential Binary Phase Shift Keying) modulation. The preamble has 33 bits which is an optional bit pattern irrelevant to BCH code. The above 36-bit data contains information on linked network type, inherent ID, message and index to be transmitted, and message type, etc., where 4 bits are allocated for setting the above message type, and the combinations of the above 4 bits can be used to be assigned for free destination information for the implementation of the present invention. 
     When repeating data ata transmission is repeated in order of AB, AB, . . . , after the preamble is repeatedly transmitted. For example, when using the other party&#39;s telephone number as destination information, in order to change the destination information into the above-mentioned data type for transmission, the original data A and B, each of 33 bits, and the above destination information data C and D, each of 33 bits, are transmitted. In this case, when repeating data transmission, the data transmission is repeated in order of ABCD, ABCD . . . , after the preamble is repeatedly transmitted. 
     Referring to FIG. 3, in the present embodiment, it is assumed that the other party&#39;s telephone number is the destination information. Accordingly, the numerals “0”˜“9” are displayed on the screen, and a cursor  41  blinks under any one of the numerals, whereby the numerals are selected by moving the cursor  41 . The key inputter  10  comprises direction keys  42 ,  43  for moving the cursor  41  in the right or left direction, and a return key for inputting the selected numerals. 
     Referring to FIG. 4, when a user actuates the response message function key (key for setting the response message transmitting function), in Step  4   a , the control unit  13  detects the above key actuation, and proceeds to Step  4   b  to retrieve the destination selecting screen information prestored in the memory  15  and displays such information on the display unit  16 . In Step  4   c , when the user selects a destination on the screen of the display unit  16  by means of the key inputter  10 , the control unit  13  proceeds to Step  4   d  to access to the memory  15  for checking whether the selected destination exists, i.e, is registered in the corresponding information table (i.e., database). However, if the selected destination is not registered, the control unit  13  recognizes it as being free destination information (i.e., not previously registered destination). In this case, when entering free destination information not registered in advance, the user can additionally enter a specific key (e.g., ‘*’) to inform the control unit  13  that the destination status of the information is free, so that the above checking operation may be skipped. 
     When a free destination status is selected, the control unit  13  proceeds to Step  4   e  to set the free destination flag, and then proceeds to Step  4   f  to select one of the preset various response messages. Thereafter in Step  4   g , the control unit  13  transmits the message having the same format as shown in FIG. 2, which is a bit combination representing a message type, which includes the free destination information. 
     A central control system receives the above message through the base station equipment and analyzes the message type to detect the destination information, and calls the corresponding destination, thereby transmitting a response message. The above destination may be a conventional telephone apparatus, a facsimile machine, a telephone connected to a PC, or another bidirectional radio pager. 
     Referring to FIG. 5, the radio paging system  100  of the present invention comprises a plurality of radio paging devices, e.g.,  52 ,  54 ,  56  carried by users, a plurality of base station equipment units, e.g.,  22  and  24 , and a central control system  32 . While, for the sake of simplicity, only a few radio paging devices and base station equipment units are shown in FIG. 5, it is to be appreciated that more or less devices and units may be employed in the invention. 
     In the case where the radio paging system  100  is a bidirectional radio paging system, the above paging devices  52 ,  54 ,  56  each have a respective transmitter, and the above base station equipment units  22 ,  24  each have a respective reverse paging terminal capable of receiving signals transmitted by the above radio paging devices  52 ,  54 ,  56 . Further, the above central control system  32  has a downlink/uplink control device. For the downlink operation, the POCSAG coding system, used worldwide at the present time, is preferably adopted. The POCSAG coding system is proposed expressly by the CCIR Recommendation No. 584. For the uplink operation, the aforementioned code format as shown in FIG. 2 is used. In the present embodiment, the device for controlling uplink operation is referred to as an “uplink control device”. 
     For example, when the paging device  52  transmits paging messages in the operational area of the base station equipment  22 , messages intended for the conventional telephone  300 , the facsimile machine  400 , and/or the personal computer  500  are received through the switchboard (PSTN)  200 , and response messages intended for another paging device  56  are received through the corresponding base station equipment unit  22 . When the base station equipment unit  22  transmits a response message to the telephone  300  under the control of the central control system  32 , the above switchboard  200  calls the telephone  300  according to the received destination information (telephone number) and at the same time, the voice mail unit  250  provides corresponding voice information according to the response message index information received simultaneously. When transmitting messages to the facsimile machine  400 , the PC  500 , or to the other bidirectional radio pager  56 , character messages are chiefly used. 
     As mentioned above, the present invention advantageously provides that the paged party can freely select and respond to the paging party without limiting the scope of the paging parties available for response, so that the efficiency of the bidirectional radio pager can be significantly improved in terms of utilization thereof, and the user can respond also to non-registered paging parties without taking additional measures for response. 
     Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention.