1. Field of Invention
The invention relates to services based on location data on mobile stations, particularly to transmitting information based on location data onto the display of a mobile station.
2. Brief Description of Related Developments
Various services based on location data on a mobile station are being developed for present mobile systems. Network operators and service providers operating via them develop present services of mobile systems so as to make them dependent of location data, and also create completely new services based on location data. Services based on location data may be for instance security services, such as emergency or accident notifications directed to a given area, billing service based on location, such as lower tariffs in the area of the home or office cells of a mobile station, positioning services, such as updating location data on a transport company's cars to the office via a mobile network, or general information services, such as information relating to an event or traffic jams in the area of occurrence.
The location of a mobile station can be determined by various methods, each of which provides a different accuracy in defining location data. The location can be determined for example at the accuracy of the cell of the mobile network to which the mobile station is attached at each particular time (COO, Cell of Origin), on the basis of different triangulation methods (E-OTD, Enhanced Observed Time Difference, TOA, Time of Arrival), whereby the signaling of the mobile station to different base stations is utilized, or by means of satellite positioning, such as the GPS system (Global Positioning System). The location update method used in connection with a service typically depends on the accuracy of the location data required for using the service.
The cell broadcast short message service (CBS) has been developed for mobile systems, such as the GSM system (Global System for Mobile Communication), allowing ‘broadcast areas’ to be determined at the accuracy of a cell, and CB short messages to be transmitted to mobile stations located in the area of the cells. CB short messages comprise text-based messages intended for either all mobile stations in the broadcast area, such as billing zone information messages, or only those mobile stations in the broadcast area that have ordered a given service, such as traffic or weather report messages. CB short messages are thus one-way messages, determined by network operators or service providers operating via them, and transmitted to mobile stations located in a given area. As a technical solution, the transmission of CB short messages largely resembles the transmission of short messages (SMS, Short Message Service) from a mobile station, i.e. the transmission of text messages or SMS messages; even through the structure of said messages slightly differs (the maximum length of a CB message is 93 characters and that of an SMS message 160 characters), and the same kind of certainty of the arrival of CB messages at a mobile station is not received as in the transmission of SMS messages. However, both messages are read on a mobile station typically by browsing through the user interface of the mobile station, typically with the keyboard using a function menu of the mobile station.
The problem in the above arrangement is that CB messages are text-based and difficult to read. A service based on location data on a mobile station is typically delivered to the mobile station when it reaches an area according to a given location definition. In this case the user of the mobile station is mobile, e.g. walking or driving, and browsing through the function menu of the mobile station by means of the keyboard causes the attention to be drawn away from the movement, potentially causing risky situations. Once a received CB message is read, the function menu typically returns to an initial state, and if the information in the CB message is to be reread, said CB message has to be retrieved by browsing through the function menu. A further problem is that the information to be transmitted by means of CB messages is limited; although several CB messages may be chained to one longer message, the transmission of a larger amount of information is not practical by means of CB messages. There is therefore a need for a procedure for transmitting information based on location data to a user of a mobile station illustratively so that reading the information does not require any special measures of the user of the mobile station.