Typically, in today's third generation (3G) networks, a limited number of centrally placed Gateway GPRS Support Nodes (GGSNs) are used to provide wireless capabilities for users. For example, there may be four GGSNs that provide wireless coverage for the United States, each serving a different coverage area. One of the main functions of a GGSN is that it assigns an internet protocol (IP) address to a mobile device when the mobile device enters into its coverage area. For example, the IP address of the mobile device does not change as it moves throughout the coverage area of one GGSN. However, when the mobile device enters into a new coverage area corresponding to a different GGSN, the new GGSN will assign a new IP address for the mobile device to use. In fourth generation (4G) networks, a public data network gateway (P-GW) maybe used instead of the GGSN to provide IP address assignment.
The conventional method of assigning IP addresses by a centrally located gateway may cause problems relating to reliability and scalability. For example, in terms of reliability, if one of the limited number of central gateways is inoperable, wireless capabilities may be affected for a significant portion of mobile devices. Also, in terms of scalability, when the mobile device enters into a different coverage area that is served by another central gateway, the mobile device will lose connectivity (as it re-configures its new IP address), thereby causing a disruption in service. For some applications of the mobile device such as any type of voice application, the mobile device may lose critical information during such disruptions in service. Furthermore, as internet traffic increases, the centralized solution becomes less practical due to scalability requirements. As a result, some methods use a distributed solution involving more central gateways in order to provide increased scalability. However, the increased number of central gateways may result in further disruptions in service caused by the mobile device receiving a new IP address every time the mobile device enters into a new coverage area.