Mobile location-based voice over internet protocol group call service

Location-based services provide information and entertainment services depending on the current geographical position of a user. This can be used for tourist information, where a foreigner receives a message if he is near a point of interest. Today, an increasing amount of people possesses modern smartphones, which are capable for location-based services. We have combined location-based services with internet telephony to build a position dependent group call service. A user is then able to contact all members of a specified group that are in close proximity or geographical area. Such a service is currently not available and can be seen as the next step of instant messaging, which allows users to communicate more personally than just by text. To ensure security, all participants have to authenticate themselves against the group call service. All recipients are informed in parallel about new voice messages. The presented service is capable to securely distribute voice messages to people in a specific geographical area.