Methods and apparatus for supporting micro-mobility within a radio access network
First Claim
1. A system for forwarding data packets to a mobile terminal comprising:
- a radio access network comprising at least one externally connected gateway node, a plurality of packet routers, and a plurality of radio access nodes each having a respective coverage area and each capable of establishing a wireless communications link with mobile terminals within the respective coverage area, each packet router and each radio access node having a respective network address, each packet router associating a next-hop forwarding entry with each of the radio access nodes;
a first protocol adapted to provide an assigned network address to a mobile terminal for a communications session initially through a particular radio access node within whose coverage area the mobile terminal is located and to broadcast the assigned network address and the network address of the particular radio access node to the plurality of packet routers so as to cause each packet router to create a new next-hop forwarding entry for the mobile terminal, the new next-hop forwarding entry for the mobile terminal corresponding with the next-hop forwarding entry for the particular radio access node;
a second protocol adapted to update the next-hop forwarding entries for the mobile terminal for a subset of the packet routers when the mobile terminal moves from the coverage area of the particular radio access node to the coverage area of a subsequent radio access node by causing each packet router in the subset of packet routers to change the next-hop forwarding entry for the mobile terminal to correspond with the next-hop forwarding entry for the subsequent radio access node;
a third protocol adapted to define said subset of the packet routers for each {particular radio access node, subsequent radio access node} pair such that only the subset of packet routers are required to update their next-hop forwarding entries for a mobile terminal handoff from the particular radio access node to the subsequent radio access node.
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Accused Products
Abstract
The invention provides a novel protocol suite for supporting micro-mobility within a radio access network (RAN). The protocol suite and comprises three separate protocols, namely a Mobile Registration Protocol, a Handoff Affected Router Discovery Protocol (HARDP) and a Mobile Location Update Protocol. The Mobile Registration Protocol is used to register mobile terminals within a RAN while the Mobile Location Update Protocol is used to update mobile terminal reachability during a handoff. The HARDP protocol is used at network boot-up time to identify a subset of routers that needs to be updated when a mobile terminal handoff occurs between two neighboring radio access nodes.
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Citations
36 Claims
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1. A system for forwarding data packets to a mobile terminal comprising:
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a radio access network comprising at least one externally connected gateway node, a plurality of packet routers, and a plurality of radio access nodes each having a respective coverage area and each capable of establishing a wireless communications link with mobile terminals within the respective coverage area, each packet router and each radio access node having a respective network address, each packet router associating a next-hop forwarding entry with each of the radio access nodes;
a first protocol adapted to provide an assigned network address to a mobile terminal for a communications session initially through a particular radio access node within whose coverage area the mobile terminal is located and to broadcast the assigned network address and the network address of the particular radio access node to the plurality of packet routers so as to cause each packet router to create a new next-hop forwarding entry for the mobile terminal, the new next-hop forwarding entry for the mobile terminal corresponding with the next-hop forwarding entry for the particular radio access node;
a second protocol adapted to update the next-hop forwarding entries for the mobile terminal for a subset of the packet routers when the mobile terminal moves from the coverage area of the particular radio access node to the coverage area of a subsequent radio access node by causing each packet router in the subset of packet routers to change the next-hop forwarding entry for the mobile terminal to correspond with the next-hop forwarding entry for the subsequent radio access node;
a third protocol adapted to define said subset of the packet routers for each {particular radio access node, subsequent radio access node} pair such that only the subset of packet routers are required to update their next-hop forwarding entries for a mobile terminal handoff from the particular radio access node to the subsequent radio access node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 30, 31, 34)
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13. A method for forwarding data packets to a mobile terminal within a radio access network comprising a plurality of packet routers and a plurality of radio access nodes each having a respective network address, the method comprising:
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providing each packet router with a respective next-hop forwarding table populated with next-hop forwarding entries for each of the plurality of radio access nodes;
providing an assigned network address to a mobile terminal for a communications session initially through a particular radio access node within whose coverage area the mobile terminal is located;
broadcasting the assigned network address and the network address of the particular radio access node to the plurality of packet routers so as to cause each packet router to create a new next-hop forwarding entry for the mobile terminal, the new next-hop forwarding entry for the mobile terminal corresponding with the next-hop forwarding entry for the particular radio access node;
updating the next-hop forwarding tables of a subset of the plurality of packet routers when the mobile terminal moves from the coverage area of the particular radio access node to the coverage area of a subsequent radio access node by causing each packet router in the subset of packet routers to change the next-hop forwarding entry for the mobile terminal to correspond to the next-hop forwarding entry for the subsequent radio access node.
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19. A packet router comprising:
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a next-hop forwarding table populated with a next-hop forwarding entry for each of a plurality of mobile terminals and radio access nodes;
an input adapted to receive a message identifying a network address for a mobile terminal and a network address for a particular radio access node within whose coverage area the mobile terminal is located;
a message processor adapted to process said message by;
in the event no next-hop forwarding entry exists for the mobile terminal, adding a new next-hop forwarding entry to the next-hop forwarding table for the mobile terminal, the new next-hop forwarding entry corresponding to the next-hop forwarding entry already in the table for the particular radio access node;
and in the event a next-hop forwarding entry exists for the mobile terminal, changing the next-hop forwarding entry for the mobile terminal to correspond to the next-hop forwarding entry already in the table for the particular radio access node;
wherein a data packet to be routed contains a destination network address of a mobile terminal to which the packet is to be routed, and the packet router forwards the packet according to the next-hop forwarding entry for the destination network address contained in the packet.
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27. A radio access node adapted to provide wireless access service to a mobile terminal within a radio access network comprising a plurality of packet routers and an address server, the radio access node being adapted to:
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receive a first message from the mobile terminal requesting a network address for the mobile terminal from the address server;
process said first message by sending a second message to the address server requesting a network address to be assigned to the mobile terminal;
receive a second message from the address server comprising the assigned network address;
process said second message by sending a third message to the mobile terminal comprising the assigned network address from the address server;
broadcast a fourth message to the plurality of packet routers, the fourth message comprising the network address of the radio access node and the assigned network address for the mobile terminal.
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28. A radio access node adapted to provide wireless access service to a mobile terminal within a radio access network, the radio access network comprising a plurality of packet routers and a plurality of radio access nodes each having a respective coverage area and each capable of establishing a wireless communications link with mobile terminals within the respective coverage area, each packet router and each radio access node having a respective network address, the radio access network further comprising an address server for assigning a multicast address to represent a subset of the packet routers that needs to be updated when the mobile terminal moves from the coverage area of the particular radio access node to the coverage area of a subsequent radio access node, the radio access node comprising:
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a message processor adapted to send a first message to the subsequent radio access node;
an input adapted to receive a second message from the subsequent radio access node comprising the multicast address assigned by the address server;
the message processor further adapted to broadcast a third message to the plurality of packet routers, the third message comprising the network address of the particular radio access node, the network address of the subsequent radio access node and the assigned multicast address for said subset of packet routers.
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29. A radio access node adapted to provide wireless access service to a mobile terminal within a radio access network, the radio access network comprising a plurality of packet routers and a plurality of radio access nodes each having a respective coverage area and each capable of establishing a wireless communications link with mobile terminals within the respective coverage area, each packet router and each radio access node having a respective network address, the radio access network further comprising an address server for assigning a multicast address to represent a subset of the packet routers that needs to be updated when the mobile terminal moves from the coverage area of the particular radio access node to the coverage area of a subsequent radio access node, the radio access node comprising:
a message processor adapted to implement a third protocol wherein the third protocol defines said subset of packet routers for the particular radio access node, subsequent radio access node pair.
- 32. A method of providing micro-mobility support to a radio access network wherein only a reduced number of routers update their next-hop forwarding tables when a mobile terminal performs a handoff.
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36. A mobility agent adapted to be connected with other mobility agents using IP tunnels, the mobility agent being adopted to provide a protocol suite comprising:
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a first protocol adapted to provide an assigned network address to a mobile terminal for a communications session initially through a particular radio access node within whose coverage area the mobile terminal is located and to broadcast the assigned network address and the network address of the particular radio access node to a plurality of packet routers so as to cause each packet router to create a new next-hop forwarding entry for the mobile terminal, the new next-hop forwarding entry for the mobile terminal corresponding with the next-hop forwarding entry for the particular radio access node;
a second protocol adapted to update the next-hop forwarding entries for the mobile terminal for a subset of the packet routers when the mobile terminal moves from the coverage area of the particular radio access node to the coverage area of a subsequent radio access node by causing each packet router in the subset of packet routers to change the next-hop forwarding entry for the mobile terminal to correspond with the next-hop forwarding entry for the subsequent radio access node;
a third protocol adapted to define said subset of the packet routers for each {particular radio access node, subsequent radio access node} pair such that only the subset of packet routers are required to update their next-hop forwarding entries for a mobile terminal handoff from the particular radio access node to the subsequent radio access node.
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Specification