Abstract: user equipment while the user equipment is disconnected from the system. The user equipment connects to the proxy and establishes a proxy session with the proxy. The proxy opens a proxy session for the user equipment, establishes a registration within said IMS network for IMS services on behalf of the user equipment; and maintains the registration for the user equipment for the duration of the proxy session. While the proxy session is ongoing, the user equipment can disconnect from the IP proxy.

Abstract: A network node provides presence updates to mobile users. The node reduces the amount of network traffic by eliminating the need for explicit messaging used to inform a user of presence updates. Additionally, the node reduces network traffic by consolidating presence updates, and sending the user only changed portions of the presence information.

Abstract: There is described an interconnect hub for routing an Instant Message (IM) or related communication between a sending IM device in a first IM community and a recipient IM device in one of a plurality of potential second IM communities. The interconnect hub comprises a router for determining the destination of IM communications and routing the IM communications to the intended recipient, a search function for finding the service provider providing IM services to the user identifier, and a cache comprising a plurality of records associating user identifiers with corresponding service providers (mobile or Internet). When the IM communication is received by the interconnect hub, the router examines the recipient user identifier, accesses the cache keying on the recipient user identifier, retrieves the service provider associated with the recipient user identifier, and forwards the IM communication to the associated service provider for delivery to the intended recipient.

Abstract: In an instant messaging system, message latency is reduced by initiating traffic channel set-up at a receiving device concurrently while a sending device is generating the instant message. When a user begins generating an instant message, the sending device transmits a service request to a payload and connection server to indicate that an instant message is pending. Upon receipt of the service request, the payload and connection server notifies the receiving device so that the receiving device can initiate traffic channel set-up concurrently while the instant message is being recorded. When the traffic channel is established, the receiving device polls the server. If the instant message is not yet received by the payload and connection server when the polling request is received, the payload and connection server waits a predetermined period of time to receive the pending instant message and forwards the instant message when it is received.

Abstract: A presence server comprises a state machine to maintain current machine states for a plurality of users, and a mapper to map the current machine state for each user to a corresponding presence status.

Abstract: Methods and systems for protecting the privacy of a user of a communication system that include enabling a first user to block a second user so that the first user generally appears to the second user to be unavailable. The method includes allowing a third user to establish a group that includes the first user and the second user. The group may be any sort of group that involves communication among three or more users. For example, the group may be an instant message group, voice chat, conference call, video conference, or any other suitable group communication. The method also enables a blocked user to be temporarily unblocked so as to prevent his blocking decision to be revealed to the blocked user.