Mobile instant messaging service over cellular networks

The popularity of Internet-based instant messaging services (e.g. MSN Messenger, ICQ) is rapidly increasing. Due to the huge number of mobile subscribers, there is a real demand to provide such a service to mobile clients. In order to do so, there is a need to keep track on both the presence and the locations of the participating clients. That is, each subscriber must be always aware about the whereabout of all the other members in its group, and who are the active members at any given moment. A Mobile Instant Messaging (MIM) service is expected to provide to its members an improved, easy-to-use inter-group connectivity, and to support advanced services such as a conference call, a multicast message, and a group search, in an efficient manner. A method for handling an instant messaging service for mobile users over a cellular infrastructure is developed in this study. The main focus is on tracking the presence and the locations of the participating members in an efficient manner, and on the wireless cost of providing advanced group services, such as multicast messages and a conference call, to the group members.