Patent ID: 7447765

Claim:
A method for processing an emergency call from an anonymous user device in a packet data network communication system, the user device having an identity that is not valid for non-emergency use of the packet data network communication system, the method comprising: receiving an attach request message and an activate packet data protocol (PDP) context request message from an anonymous user device, the attach request message including at least an identity for the user device and the activate PDP context request message including at least a protocol configuration options information element; determining whether the identity for the user device is valid for non-emergency packet data communications in the packet data network communication system; determining whether the protocol configuration options information element indicates an emergency context; in the event that the protocol configuration options information element indicates an emergency context and the identity for the user device is not valid for non-emergency packet data communications in the packet data network communication system: determining that the activate PDP context request message is a request to establish an emergency context for an emergency call, determining an interim identify for the user device, establishing a PDP context for the emergency call, wherein the PDP context for the emergency call remains active through a predetermined callback period, assigning an interim internet protocol (IP) address to the user device for use during the PDP context for the emergency call only and associating the interim IP address to the interim identity for the user device, and determining at least one authorized IP address that is permitted to send data packets to and receive data packets from the interim IP address while the PDP context for the emergency call is active, wherein the at least one authorized IP address corresponds to at least one device used to provide communication for emergency services in response to the emergency call; receiving data packets while the PDP context for the emergency call is active; determining whether the received data packets include the interim IP address and the at least one authorized IP address; in the event that the received data packets include the interim IP address and the at least one authorized IP address, routing the received data packets between the interim IP address and the at least one authorized IP address; and in the event that the received data packets include the interim IP address but not the at least one authorized IP address, blocking the received data packets from being routed in the packet data network communication system to thereby prohibit communication between the interim IP address and unauthorized IP addresses while the PDP context for the emergency call is active.