Abstract: The present invention is a system, method and network (110) for multicast distribution of presence information to a plurality of communication devices (102, 104, 106, 108). A contact list (122, 124, 126, 128), associated with each communication device, identifies one or more of the other communication devices. The network provides one or more multicast addresses based on the contact lists of the communication devices to the plurality of communication devices. The network also sends multicast messages identified by the one or more multicast addresses to the plurality of communication devices. Each multicast address identifies a group of multicast devices among the plurality of communication devices, and the multicast messages include presence information about the group of multicast devices.

Abstract: The preferred embodiments of the present invention provide a direct response system with instant messaging and role based contact lists. An object of the present invention is to replace traditional dispatch systems. In preferred embodiments of the present invention, a user selects a generic role entry on a messaging client device (102) and establishes communication. The client device (102) transmits an electronic message addressed to a particular responder client device (202). The responder client device (202) address information is transmitted to the initiating client device (102) via a status update received from a public server (112).

Abstract: The present invention is a network (110) and method for conducting a group call among communication devices (102, 104, 106, 108) based on presence information of the communication devices. The presence information (FIGS. 2 and 3) is displayed (410) at a particular communication device (106) that has access to a contact list (126), which identifies members of the group call. The presence information includes a presence status for each of the members of the group call. Next, the network detects (430) an activation of the group call at the particular communication device. In response to detecting the activation, the network establishes (440) the group call among the communication devices based on the contact list of the particular communication device. To establish the group call, a communication link is established with each of the members of the group call.

Abstract: The present invention is a system, method and network (110) for multicast distribution of presence information to a plurality of communication devices (102, 104, 106, 108). A contact list (122, 124, 126, 128), associated with each communication device, identifies one or more of the other communication devices. The network provides one or more multicast addresses based on the contact lists of the communication devices to the plurality of communication devices. The network also sends multicast messages identified by the one or more multicast addresses to the plurality of communication devices. Each multicast address identifies a group of multicast devices among the plurality of communication devices, and the multicast messages include presence information about the group of multicast devices.