Patent ID: 9521110
Filing Date: 2016-12-13
CPC Classification: H04L,H04W

Claim Text:
1. A method for releasing an internet protocol (IP) address by a packet data network gateway (PGW) in a mobile communication system, the method comprising: allocating an IP version 4 (IPv4) address and an IP version 6 (IPv6) address to a terminal to establish a packet data network (PDN) connection between the terminal and the PGW; detecting release of the IPv4 address allocated to the terminal; identifying a PDN type associated with the PDN connection in response to detecting the release of the IPv4 address; transmitting to a serving gateway (SGW), a binding revocation message if the identified PDN type is IPv4 and IPv6, the binding revocation message including information indicating that the IPv4 address is released and the PDN connection is maintained; and receiving, from the SGW, a binding revocation acknowledge message in response to the binding revocation request message.