System and method for achieving continuous connectivity to an access point or gateway in a wireless network following an on-demand routing protocol, and to perform smooth handoff of mobile terminals between fixed terminals in the network
First Claim
1. A method for maintaining a route to an access point in a wireless communication network, the method comprising:
- transmitting an access point advertisement from the access point to at least one node of the network in a broadcast range of the access point;
transmitting a route request message from said at least one node to the access point upon receipt of the access point advertisement with desired criteria by said at least one node;
transmitting a reply message from the access point to said at least one node upon receipt of the route request message by the access point;
rebroadcasting the access point advertisement from said at least one node to at least one other node of the network in a broadcast range of said at least one node;
transmitting a route request message from said at least one other node to said at least one node upon receipt of the rebroadcast access point advertisement with desired criteria by said at least one other node;
if a destination only flag of the route request message from said at least one other node is not set, the transmitting a reply message from said at least one node to said at least one other node, and a gratuitous reply message from said at least one node to the access point, upon receipt of the route request message by said at least one node; and
if the destination only flag of the route request message is set, then forwarding the route request message from said at least one node to the access point.
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Accused Products
Abstract
A system and method for enabling an ad-hoc communication network to maintain connectivity with the mobile nodes in the network in an effective and efficient manner with minimal overhead. The system and method enables an ad-hoc communication network to maintain connectivity between intelligent access points of the network and mobile nodes in the network while performing an on-demand protocol. The system and method further uses an improved distance vector routing algorithm and unicast messages, to thus avoid an increase routing advertisement frequency in the network while keeping network overhead at a minimum. The system and method also modifies the Ad Hoc On-Demand Distance Vector Routing (AODV) protocol to facilitate smooth handoff of subscriber devices in an ad-hoc communication network while also eliminating unidirectional links between nodes in the network.
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Citations
24 Claims
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1. A method for maintaining a route to an access point in a wireless communication network, the method comprising:
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transmitting an access point advertisement from the access point to at least one node of the network in a broadcast range of the access point;
transmitting a route request message from said at least one node to the access point upon receipt of the access point advertisement with desired criteria by said at least one node;
transmitting a reply message from the access point to said at least one node upon receipt of the route request message by the access point;
rebroadcasting the access point advertisement from said at least one node to at least one other node of the network in a broadcast range of said at least one node;
transmitting a route request message from said at least one other node to said at least one node upon receipt of the rebroadcast access point advertisement with desired criteria by said at least one other node;
if a destination only flag of the route request message from said at least one other node is not set, the transmitting a reply message from said at least one node to said at least one other node, and a gratuitous reply message from said at least one node to the access point, upon receipt of the route request message by said at least one node; and
if the destination only flag of the route request message is set, then forwarding the route request message from said at least one node to the access point. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A wireless communication network, comprising:
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an access point, adapted to provide access to a portion of the network; and
a plurality of wireless nodes, adapted to communicate with each other and gain access to said portion of said network via the access point;
the access point being further adapted to transmit an access point advertisement to said nodes which are in its broadcast range, the nodes being further adapted to transmit a respective route request message to the access point upon receipt of the access point advertisement with desired criteria, and the access point being further adapted to transmit a respective reply message to the nodes upon receipt of the respective route request messages; and
each of the nodes being adapted to rebroadcast the access point advertisement to other nodes of the network in its respective broadcast range, to receive a respective route request message from each of said other nodes that received the rebroadcast access point advertisement, and, upon receipt of the respective route request messages, to transmit a respective reply message to the respective other nodes and a respective gratuitous reply message to the access point for those of said respective route request messages whose destination only flag is not set, and to instead forward to the access point those of said respective route request messages whose destination only flag is set. - View Dependent Claims (8, 9)
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10. A method for performing handoff of a mobile subscriber device between first and second wireless routers in a communication network, the method comprising:
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when the subscriber device is moving from a coverage area of the first wireless router to a coverage area of the second wireless router, unicast transmitting a routing advertisement, including information identifying the subscriber device, from the subscriber device to the second wireless router;
updating a routing table of the second wireless router in accordance with the information included in the routing advertisement when the second wireless router receives the routing advertisement; and
unicast transmitting another routing advertisement, including information identifying the subscriber device, along a path of communication between the second wireless router and an access point via which the second wireless router gains access to a portion of the network, to inform the access point of the subscriber device. - View Dependent Claims (11, 12)
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13. A wireless communication network, comprising:
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a plurality of wireless routers associated with an access point via which the wireless routers gain access to a portion of the network; and
a mobile subscriber device, adapted to communicate with any said wireless router within its broadcast range;
wherein when the subscriber device is moving from a coverage area of a first wireless router to a coverage area of a second wireless router, the subscriber device unicast transmits a routing advertisement, including information identifying the subscriber device, to the second wireless router, and when the second wireless router receives the routing advertisement, the second wireless router updates its routing table in accordance with the information included in the routing advertisement, and unicast transmits another routing advertisement, including information identifying the subscriber device, along a path of communication between the second wireless router and the access point, to inform the access point of the subscriber device. - View Dependent Claims (14, 15)
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16. A method for performing handoff of a mobile subscriber device between wireless routers in a communication network, the method comprising:
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controlling the mobile subscriber device to transmit at a periodic rate a routing request message for an associated access point to the communication network;
receiving the routing request message at one of the wireless routers; and
providing the routing request message from the wireless router at which it was received to the associated access point to inform the associated access point of a route to the mobile subscriber device. - View Dependent Claims (17, 18)
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19. A wireless communication network, comprising:
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a plurality of wireless routers associated with an access point via which the wireless routers gain access to a portion of the network; and
a mobile subscriber device, adapted to communicate with any said wireless router within its broadcast range, to transmit at a periodic rate a routing request message for an associated said access point to said any wireless router, which is adapted to provide the routing request message to the associated access point to inform the associated access point of a route to the mobile subscriber device. - View Dependent Claims (20, 21)
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22. A method for performing handoff of a mobile subscriber device between wireless routers in a communication network, the method comprising:
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controlling the mobile subscriber device to evaluate respective routing metrics associated with the respective wireless routers as the mobile subscriber device is moving; and
controlling the mobile subscriber device to send a routing request message to the wireless router whose respective said routing metrics meet a desired criteria. - View Dependent Claims (23, 24)
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Specification