Abstract:
When a message source user desires to advertise an object such as an event or a sight-seeing resort on an electronic board, a write request is formulated with a message and auxiliary information as to the position and state of affairs of the object, and transmitted to a server finder. Using the position information of the request, the server finder selects one of a number of message board servers for retransmission of the request. On receiving the write request, the selected server maps the contents of this request in a database. When a message recipient user desires to read a message, a read request is formulated with auxiliary information of a desired object and transmitted to the server finder, which retransmits it to one of the servers corresponding to its position information. On receiving the read request the selected server searches its database for messages having likeness to the auxiliary information of the request.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to message communication systems and more specifically to a system and method for advertising messages on an electronic board. 
   2. Description of the Related Art 
   The message board is one form of communication between message source users and message recipient users over a communications network. The message board is a database provided in a message board server. Message source users send write requests to the server to write their messages on the message board and message recipient users send read requests to the server to read the contents of the message board. In the prior art, a string of characters known as URL (Uniform Resource Locator) is used to identify the message board. If the message source user creates a message board, he is required to acquire the URL of the server. However, this is tedious and time-consuming if the message source user moves around a people-gathering place and instantly writes an advertising message of a public event that reflects the state of affairs of the place. In addition, a technical knowledge is necessary to create a message board. 
   Therefore, a need exists to allow users to access a message board server without the need to acquire the URL of the message board. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a system and method for instantly accessing a desired message board server. 
   According to one aspect of the present invention, there is provided a communication system comprising a communications network, a message source terminal, a message recipient terminal, a plurality of message board servers and a server finder. The message source terminal transmits a write request via the network to the server finder, containing a message of an advertised object and auxiliary information as to the position and state of affairs of the object. In response to the write request, the server finder selects one of the servers based on the position information of the write request and retransmits the write request via the network to the selected server. The message recipient terminal transmits a read request via the network to the server finder, containing auxiliary information as to the position and state of affairs of an object. In response to the read request, the server finder selects one of servers based on the position information of the read request and retransmits the read request via the network to the selected server. Each of the message board servers, on receiving the write request from the server finder, stores the contents of the write request in an entry of a database, and on receiving the read request from the server finder, makes a search through the database for detecting a plurality of messages having likeness to the contents of the received read request. 
   Preferably, each message board server detects a plurality of differences in quantitative terms between the state-of-affairs information contained in the read request and a plurality of state-of-affairs information stored in the database, compares the differences with a decision threshold to select a group of the differences smaller than the decision threshold, and reads the group of messages from the database corresponding to the group of differences. 
   According to a second aspect, the present invention provides a method of advertising messages comprising the steps of (a) transmitting a write request from a message source terminal to a server finder via a communications network, the write request containing a message and auxiliary information, the auxiliary information indicating the position of an object to be advertised and state of affairs of the object, (b) receiving, at the server finder, the write request, selecting one of a plurality of message board servers based on the position information of the write request and retransmitting the write request via the network to the selected server, (c) receiving, at the server selected by step (c), the retransmitted write request and storing the message and the auxiliary information contained in the write request in an entry of a database, (d) transmitting a read request from a message recipient terminal to the server finder via the communications network, the read request containing auxiliary information indicating the position of an advertised object and state of affairs of the object, (e) receiving, at the server finder, the read request, selecting one of the servers based on the position information of the read request and retransmitting the read request via the network to the selected server, and (f) receiving, at the server selected by step (e), the retransmitted read request and detecting a group of auxiliary information in the database having likeness to the auxiliary information contained in the received read request, and reading a group of messages from the database corresponding to the group of auxiliary information for transmission to the message recipient terminal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described in detail further with reference to the following drawings, in which: 
       FIG. 1  is a block diagram of a communications network of the present invention; and 
       FIG. 2  is a flowchart of the operation of a message source terminal when a write request is transmitted to the network; 
     Fig,  3  is a flowchart of the operation of the service provider of  FIG. 1  when the write request is received from a message source terminal; 
       FIG. 4  is a flowchart of the operation of a message board server when a write request is received from the service provider; 
       FIG. 5  is a flowchart of the operation of a message recipient terminal when a read request is transmitted to the network; 
       FIG. 6  is a flowchart of the operation of the service provider when a write request is received from a message recipient terminal; and 
       FIG. 7  is a flowchart of the operation of a message board server when a read request is received from the service provider. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , there is shown a communication system of the present invention. The system is comprised of a communications network  10 , and a service provider (server finder)  11  and a plurality of message board servers  12 . Communications network  10  includes a wireless mobile network and the Internet (not shown) to allow wireless mobile terminals  13  and  14  to access the service provider  11 . 
   Service provider  11  includes a processor  21  that is connected to the network  10  via an interface  20  and a URL database  22 . URL database  22  has a plurality of entries for mapping state-of-affairs information and corresponding URLs identifying the message board servers  12 . 
   Each message board server  12  has a processor  31  connected to the network via an interface  30  and a message database  32 , which is an electronic message board. Database  32  has a plurality of entries for mapping state-of-affairs information and corresponding messages. Message processor  31  monitors the time lapse of each entry of the database to delete its stored information when it exceeds a predetermined length of time. 
   The following is a description of the operation of the system with reference to the flowcharts of  FIGS. 2  to  7  by assuming that the mobile terminal  13  is a cellular mobile phone of a message source user and the mobile terminal  14  is likewise a mobile phone of a message recipient user. 
   When the message source user intends to write a message about an event to be advertised into the electronic message board, he enters a message of an object such as a public event and a sight-seeing resort to be advertised and auxiliary information as to the position and state of affairs of the advertised object. The state-of-affairs information includes one of more of information as to the best season of the year, the date, the time of day, the weather, depending on the type of the advertised object. The write request contains the address information of the service provider  11 . The write request is transmitted to the network and routed to the service provider  11 . 
   In  FIG. 2 , when the message and state-of-affairs information are entered (step  201 ), the source mobile terminal  13  transmits a write request to the network containing the entered data and the URL of the service provider  11  ( 202 ). 
   In  FIG. 3 , when the processor  21  at the service provider receives the write request at step  301 , it makes a search through the URL database for the URL of a message board server corresponding to the state-of-affairs information (particularly, the location data) contained in the write request (step  302 ). If no corresponding URL is found (step  303 ), the processor  31  proceeds to make a further search through the network  10  to obtain the URL (step  304 ). If the corresponding URL is obtained (step  305 ), the state-of-affairs information is mapped to the obtained URL in one entry of the URL database  22  (step  306 ). At step  307 , the processor  21  formulates a write request with the data received from the message source terminal  13  and the obtained URL of the message server and transmits the write request to the network  10 . 
   The write request transmitted from the service provider  11  is routed through the network  10  to one of the message board servers  12  that is identified by the URL contained in the write request. 
   In  FIG. 4 , when the URL-identified message board server  12  receives the write request from the service provider  11  (step  401 ), the server stores the message and auxiliary information contained in the write request in one entry of the message database  22  (step  402 ). 
   When the user at the message recipient terminal  14  wishes to read a message from the network, he enters auxiliary information such as the current geographical location of a desired object and the current time of day and the URL of the service provider to the mobile terminal  14 . If the user is in the neighborhood of the desired object such as a music concert, the current location is the location where the user is in, When such data is entered (step  501 ), the mobile terminal  14  formulates a read request with the entered auxiliary information and sends it to the network  10  (step  502 ). As a result, the read request of the mobile terminal  14  is routed through the network  10  to the service provider (server finder)  11 . 
   In  FIG. 6 , when the server finder  11  receives the read request (step  601 ), the processor  21  selects a URL from the URL database  22  based on the position data of the auxiliary information of the read request (step  602 ) and retransmits the read request via the network  10  to the message board server  12  identified by the selected URL (step  603 ). 
   In  FIG. 7 , when the URL-identified message board server receives the read request from the service provider  11  (step  701 ), the processor  31  of the server reads the auxiliary information contained in the received read request (step  702 ). Processor  31  makes a search through the database  22  for a group of auxiliary information having a high degree of likeness to the received auxiliary information and reads a group of messages corresponding to such a group of auxiliary information. This database search proceeds as follows: 
   At step  703 , the server reads auxiliary information stored in one entry of the message database  22 . At step  704 , the processor  31  compares between the auxiliary information of the read request with the that stored in that entry of the database to calculate differences between them and yields a total value of the calculated differences as a measure of likeness to the auxiliary information the message recipient user has transmitted to the network (step  705 ). The total value of the differences is compared with a decision threshold (step  706 ). Since the auxiliary information contained in the read request includes information as to the current geographical location of the message recipient user and the current time of day, the calculated differences represent a geographical distance and a time difference (i.e., space and time differences). Therefore, the total value of these differences represents a vector sum of different dimensions. 
   If the total value is smaller than the decision threshold, the decision at step  706  is affirmative and the processor advances to step  707  to copy the message stored in the current entry of the message database  32 , and proceeds to step  708 . If the total value is not smaller than the decision threshold, flow proceeds to step  708 , without copying the message of that entry, 
   At step  708 , the processor  31  checks to see if auxiliary information has been read from all entries of the message database  32 . If not, flow returns to step  703  to repeat the search process on the next entry of the message database  32 , If likeness evaluations have been made for all entries of the database  32 , the decision at step  708  is affirmative and flow proceeds to step  709  to transmit the message copies to the service provider  11 . 
   Returning to  FIG. 6 , when the service provider  11  receives the messages from the message board server (step  604 ), the processor  21  transmits the received messages to the recipient mobile terminal  14  (step  605 ). 
   In  FIG. 5 , when the mobile terminal  14  receives a group of messages from the service provider  11  (step  503 ), the messages are displayed (step  504 ). The user at the recipient mobile terminal  14  treats the displayed messages as a group having a relatively high degree of likeness to the state-of-affair information he has transmitted on the read request. If the recipient user is located near or at the location of an advertised public event, the displayed messages may contain a message that is best fit to the current location of the user. 
   Assume that a message to be advertised by the message board server  11  is a notice of tickets for a music concert by an amateur band for advertising to young people. The message source user may hunt for public places which are popular to young people and make a trip to such places to determine the time of day at which many young people gather. If the message source user considers that the place is appropriate for holding a music concert, then he formulates a write message with state-of-affairs information including the geographical location of the public place, the time of day at which the concert will start and the time of day at which it will end, and transmits the request to the network. Additionally, the auxiliary information also contains cache data that specifies the date at which that the music concert will begin and the date at which it will end. Processor  21  allows recipient users to access the advertising message of the music concert for a period between the opening and closing dates specified by the cache data. 
   As a result, the message source user can benefit from the advantage of an approach analogous to what is known as a direct marketing approach. 
   The present invention can also be used in tourist guidance applications. In such applications, the message source user (or tourist guide) visits a sight-seeing resort and moves around looking for high spots of the tour, places for taking a rest and warning notices in exciting places and formulates a message with a description of what he has observed. The auxiliary information supplied from the message source terminal includes the season of the year and the weather condition, in addition to the geographical location and the time of day at which the information is sent to the network. The inclusion of the season and weather information serves to narrow the range of target tourist resorts with the result that message recipient users (sightseers) can easily choose best places for a particular season of the year. 
   The decision threshold used for assessing the degree of likeness to the auxiliary information entered by a tourist may be varied depending on the type of resort. For instance, if the tourist resort is a place for mountain climbing, the likeness to the season and weather information may be given priority over the likeness to the information as to the geographical location. The prioritization can be implemented by evaluating such information in quantitative terms and scaling them with different weight factors.