The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Fueled by the rapid development of electronic communication technologies, various wireless communication networks employing customer terminals are being developed. Conventional wireless communications have provided voice calling services for subscriber terminal users with no bounds on time and place and the operators offer text message services as a complement for the voice provision.
Ever since the recent development of wireless Internet has introduced a wireless Internet service via wireless communication network for mobile communication service subscribers, more enterprises participated in developing wireless Internet technologies.
Among wireless Internet services using customer terminals, a Location Based Service (LBS) has attracted much attention due to the wide application and convenience. The LBS is a communication service that determines a location of a customer terminal and provides additional information related to the location determined. The LBS is used in various fields and situations such as a rescue request, a countermeasure against a crime report, a Geographical Information System (GIS) for providing adjacent regional information, mobile charge differentiation by locations, traffic information, vehicle navigation, physical distribution control, and location-based Customer Relationship Management (CRM).
A recent LBS tends to expand service coverage by using both location information of a mobile terminal itself and that of other terminals. A scheme of inquiring locations of other terminals is performed through an asynchronous process. That is, a scheme in use provides displays of others' terminal locations by inquiring their locational track records after finally accessing the service. However, although this method of inquiring others' locations tells how much time has passed since the locational log of their terminals on screen, it is very likely that the others' terminals have changed their locations, which makes it difficult for the LBS user or positioner to find the locations and states of the others' terminals at the current location. In particular, a moving positioner may not be interested so much in the very locational information of others moving places as the state information associated with the others' locations. However, the current technology is difficult to inquire the states of neighboring users in real time, but rather permits to check information on who gave positional records along the positioner's route. This limits services from evolving to the stage where the LBS user wants to know people around by their state information.