Patent ID: 7961663

Claim:
A method of establishing an instant messaging session between mobile devices that support a data packet-based communications service over a digital mobile network system, the method comprising: opening a listening software port on an initiating mobile device to receive communications through the data packet-based communications service; transmitting an invitation message to a target mobile device through a page-mode messaging service, wherein the invitation message comprises a network address associated with the initiating mobile device and port information corresponding to the opened listening software port, and wherein the target mobile device is located by providing a unique identifier to the page-mode messaging service; receiving a response from the target mobile device at the listening software port on the initiating wireless device; and establishing a stateful instant messaging session through the data packet-based communications service between the initiating mobile device and the target mobile device, wherein the stateful instant messaging session is established in a peer-to-peer fashion without a server intermediating communications through the established stateful instant messaging session between the initiating mobile device and the target mobile device.