Patent ID: 6137791
Filing Date: 2000-10-24
Classification: H04W

Abstract:
A system for enabling a mobile station belonging to a first mobile telecommunications network utilizing a first packet communications standard to roam within a second mobile telecommunications network utilizing a second packet communications standard, said system comprising:a packet data network capable of forwarding packet data toward said first mobile telecommunications network, wherein said first mobile telecommunications network is incompatible with said second mobile telecommunications network;said first mobile telecommunications network including a home agent capable of receiving the packet data from said packet data network;a first IP tunnel located between said first mobile telecommunications network and said second mobile telecommunications network;said second mobile telecommunications network including:a foreign agent capable of receiving the packet data from the home agent through said first IP tunnel;a gateway node capable of receiving the packet data from the foreign agent;a first visited packet serving node capable of receiving the packet data from the gateway node through a second IP tunnel located between the first visited packet serving node and the gateway node;a first visited mobile switching center capable of receiving the packet data from the first visited packet serving node; anda base station capable of receiving the packet data from the first visited mobile switching center and further capable of forwarding the packet data to the mobile station, and in case the mobile station travels into a new geographic area being served by a second visited mobile switching center associated with a second visited packet serving node, said gateway node is also capable of establishing a third IP tunnel between said gateway node and said second visited packet serving node and releasing the second IP tunnel between said gateway node and said first visited packet serving node.