US 6,799,039 B2Granted

Network resource sharing during handover of a mobile station between cellular wireless networks

AssigneeNortel Networks Limited

InventorsGeng Wu, Mo-Han Fong

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Abstract

System components of cellular wireless networks are shared during and after a mobile station handover from a first cellular wireless network (system A) to a second cellular wireless network (system B). According to one aspect, layer 2/3 call control functions are anchored in a base station controller (BSC) of system A, even after a data communication is handed over from system A to system B. According to another aspect, a link layer supporting the data communication is anchored in the BSC of system A servicing the data communication. In this case, the BSC of system A interfaces with a serving BTS of system B to service the ongoing data communication. According to still another aspect, the link layer is handed over to system B but the link layer of system B continues to use a link layer transmit buffer of system A that remains in the servicing BSC of system A.

Claims21

Dependent claims

A method for servicing a data communication for a mobile station before, during and after handover of the mobile station from a first wireless network to a second wireless network, the method comprising:

centralized link layer protocol functions of a base station controller of the first wireless network and distributed link layer protocol functions of a base station of the first wireless network servicing the mobile station before handover;
initiating a handover of the mobile station from the first wireless network to the second wireless network;
determining a first set of data communication functions to be serviced by the first wireless network after handover, including the centralized link layer protocol functions of the base station controller of the first wireless network;
determining a second set of data communication functions to be serviced by the second wireless network after handover, wherein the second set of data communication functions include at least wireless link functions and distributed link layer protocol functions of a base station of the second wireless network;
handing over the mobile station from the first wireless network to the second wireless network;
and
servicing the mobile station after handover using the first set of data communication functions provided by the first wireless network and the second set of data communication functions performed by the second wireless network.

4 more elements

A base station controller of a first wireless network, the base station controller comprising:

a packet data serving node interface;
a base station interface that interfaces the base station controller to a plurality of base stations;
and
at least one digital processor coupled to the packet data serving node interface and the base station interface that executes software instructions causing the base station controller to:
service a data communication for a mobile station using centralized link layer protocol functions of the base station controller and distributed link layer protocol functions of a base station of the first wireless network coupled via the base station interface;
initiate a handover of the mobile station to a second wireless network;
determine a first set of data communication functions to be serviced by the first wireless network after handover, including the centralized link layer protocol functions of the base station controller;
determine a second set of data communication functions to be serviced by the second wireless network after handover, wherein the second set of data communication functions include at least wireless link functions and distributed link layer protocol functions of a base station of the second wireless network;
hand over the mobile station from the first wireless network to the second wireless network;
and
service the mobile station after handover using the first set of data communication functions provided by the first wireless network.

8 more elements

Dependencies are inferred from the claim text.