Method, user equipment and communication system for inter-rat handover in 3G LTE

A method for enabling inter-radio access technology handover in a communication system comprising a first network utilizing a first radio access technology and a second network utilizing a second radio access technology, when a user equipment moves from the first network into the second network and a handover is to be made, said method comprising:

• processing, by the user equipment, protocol data units in non-internet protocol packet format and buffered in the user equipment into internet protocol packets in response to a handover confirmation sent by equipment of the second radio access technology;
• and
• retransmitting, by the user equipment, the processed internet protocol packets to the second radio access technology equipment of the second network after the user equipment is switched to the second network.

A user equipment configured to communicate with a first network utilizing a first radio access technology and to communicate with a second network utilizing a second radio access technology, said user equipment comprising:

• a processor for processing protocol data units in non-internet protocol packet format and buffered in the user equipment into internet protocol packets in response to a handover confirmation sent by the second network;
• and
• a transmitter for retransmitting the processed internet protocol packets after the user equipment is switched to the second network.

A method for enabling inter-radio access technology handover in a communication system comprising a first network utilizing equipment of a first radio access technology and a second network utilizing equipment of a second radio access technology, when a user equipment moves from the first network into the second network and a handover is to be made, said method comprising:

• forwarding internet protocol packets processed from protocol data units in non-internet protocol packet format in response to a handover confirmation sent by the second network and buffered in the first radio access technology equipment of the first network comprising an evolved Node B from the first radio access technology equipment of the first network to the second radio access technology equipment of the second network;
• and
• retransmitting the internet protocol packets after the user equipment is switched to the second network.