Proxy based approach for IP address assignment to decrease latency of hand-offs in mobile IP telephony
AssigneeXG Technology, Inc.
InventorsShashidhar R. Gandham, Amit Shukla
Life of this patent
Estimating the term…
Abstract
A mechanism for decreasing the latency in an IP address assignment process for mobile systems using IP as network layer protocol is described. The proposed system is aimed at supporting seamless hand-offs for real-time applications like VOIP. A set of optimized messages is defined to eliminate the need for exchanging long DHCP messages to acquire an IP address. The mechanism involves splitting the IP address assignment functionality into two parts, with the base station being responsible for assigning IP addresses to individual end user devices, and the Mobile Switching Center assigning a block of IP addresses to each base station.
Claims2
A system for decreasing the latency in the IP address assignment process by splitting the IP assignment function into two separate functions for mobile wireless networks using IP as a network layer protocol comprising:
- one or more base stations;
- one or more mobile switching centers;
- one or more mobile devices;
- each of said one or more said mobile switching centers in electrical communication with one or more sub networks of said one or more base stations;
- each of said one or more mobile switching centers having a pool of IP addresses and assigning a separate sub pool of IP addresses from said pool of IP addresses to each of said one or more base stations in each of said sub networks;
- one or more mobile devices in electrical communication with one of said one or more base stations;
- each of said one or more base stations assigning an IP address from the separate sub pool of IP addresses to each of said one or more mobile devices such that as said one or more mobile devices transfer electrical communication from a current base station to a new base station within said sub network said one or more mobile devices do not have to be assigned a new IP address and said new base station sends a message to said mobile switching center that the IP address is now included in the new base station's separate sub pool of IP addresses;
- and,
- when said one or more mobile devices transfer electrical communication from a current base station to a new base station outside said sub network said one or more mobile devices sends a message requesting a new IP address assignment from said new base station, said new base station assigns a new IP address from said new base station's separate sub pool of IP addresses, and said one or more mobile devices sends a message to said current base station relinquishing the old IP address.
The system of claim 2 wherein each of said one or more base stations has an IP address timer and each of said one or more mobile devices sends a periodic keep alive message to said one or more base stations such that when a base station assigns an IP address to a mobile device said base station's IP address timer is set to a time that is counted down until said base station receives a keep alive message from said mobile device indicating said mobile device is still in use at which point the IP address timer resets and begins counting down again, or if no keep alive message is received by said base station the IP address timer counts to zero at which point the IP address is unassigned from said mobile device and is available to reassign to a different mobile device.
Dependencies are inferred from the claim text.