초록 ▼

A system and method which enables access points in a wireless ad-hoc communications network to effectively and efficiently determine the approximate location of a mobile node without performing a broadcast flood. The system and method enables a message to be efficiently communicated from an access p

A system and method which enables access points in a wireless ad-hoc communications network to effectively and efficiently determine the approximate location of a mobile node without performing a broadcast flood. The system and method enables a message to be efficiently communicated from an access point of the network, which provides access to a portion of the network or access to another network, to a wireless mobile node in the network. The system and method employ the operations of determining the access point with which the wireless mobile node is affiliated, storing information in a routing table at the affiliated access point pertaining to a routing path from the affiliated access point to the wireless mobile node, and updating the routing path when the wireless mobile node moves by a certain amount. The wireless mobile node can provide this routing path information to the affiliated access point in data packets sent to the affiliated access point. The frequency at which the updating of the routing path information occurs can be based on the degree of mobility of the wireless mobile node. The system and method further perform the operations of providing the message to the affiliated access point, sending the message from the access point to the wireless mobile node by attempting to send the message along the routing path if the routing path is unchanged, and adaptively sending the message along at least one other routing path if the routing path has changed. The frequency of occurrence of the routing path updating is based on a degree of mobility of the wireless mobile node.

대표청구항 ▼

What is claimed is: 1. A method of sending a message from an access point to a wireless mobile node in an ad-hoc wireless network, said ad-hoc wireless network comprising a plurality of nodes and at least one access point which provides said wireless mobile node and said plurality of nodes with acc

What is claimed is: 1. A method of sending a message from an access point to a wireless mobile node in an ad-hoc wireless network, said ad-hoc wireless network comprising a plurality of nodes and at least one access point which provides said wireless mobile node and said plurality of nodes with access to at least one of a portion of said network and a wired network, wherein said wireless mobile node's location in said ad-hoc wireless network changes at a non-deterministic rate, said method comprising: affiliating said wireless mobile node with said access point; identifying and storing at said affiliated access point a first routing path and associated information from said affiliated access point to said wireless mobile node, said first routing path including at least one other of said nodes between said affiliated access point and said wireless mobile node; identifying and storing at said affiliated access point a second routing path and associated information from said affiliated access point to said wireless mobile node when said wireless mobile node moves by at least a certain amount, said second routing path including at least one other of said nodes between said affiliated access point and said wireless mobile node; providing said message to said affiliated access point; and sending said message from said affiliated access point to said wireless mobile node along said first routing path when said wireless mobile node has not moved by said certain amount and sending said message from said affiliated access point to said wireless mobile node along said second routing path when said wireless mobile node has moved by at least said certain amount. 2. A method as claimed in claim 1, wherein: a frequency of occurrence of identifying said second routing path is based on a degree of mobility of said wireless mobile node. 3. A method as claimed in claim 1, wherein: said storing steps stores said routing path information in a routing table at said affiliated access point. 4. A method as claimed in claim 1, wherein: each of said first routing path and said second routing path includes at least one of said nodes other than said wireless mobile node. 5. A method as claimed in claim 1, wherein: said wireless mobile node provides said routing path information included in data packets sent to said affiliated access point. 6. A method as claimed in claim 1, wherein: said message includes a data packet. 7. A method of communicating between a wireless mobile node in an ad-hoc wireless network comprising a plurality of nodes and an access point with which said wireless mobile node is affiliated, wherein said affiliated access point provides said wireless mobile node and said plurality of nodes with access to at least one of a portion of said ad-hoc wireless network and a wired network, wherein said wireless mobile node's location in said ad-hoc wireless network changes at a non-deterministic rate, said method comprising: sending data from said wireless mobile node via a routing path to said access point, said routing path including at least one other of said nodes between said affiliated access point and said wireless mobile node, and said data including an address of said wireless mobile node and a respective address for each said other node in said routing path; storing information at said affiliated access point pertaining to said routing path from said affiliated access point to said wireless mobile node; sending a second data from said wireless mobile node via a second routing path to said affiliated access point when said wireless mobile node has moved by a certain amount, said second routing path including at least one other of said nodes between said affiliated access point and said wireless mobile node, and said data including an address of said wireless mobile node and a respective address for each said other node in said second routing path; and storing information at said affiliated access point pertaining to said second routing path from said affiliated access point to said wireless mobile node. 8. A method as claimed in claim 7, wherein each of said sending steps comprises: including said address of said wireless mobile node in said data when said wireless mobile node sends said data to said at least one other node; and each said at least one other node including its said respective address in said data when it sends said data along said routing path. 9. A method as claimed in claim 7, wherein: said data is configured as at least one data packet. 10. A method as claimed in claim 7, further comprising: sending a message from said affiliated access point to said wireless mobile node along said routing path when said wireless mobile node has not moved by said certain amount; and sending said message from said affiliated access point to said wireless mobile node along said second routing path when said wireless mobile node has moved by said certain amount. 11. An access point in an ad-hoc wireless network comprising a plurality of nodes, wherein said plurality of nodes comprises at least one wireless mobile node having a location in said ad-hoc wireless network which changes at a non-deterministic rate, said access point providing said nodes with access to at least one of a portion of said ad-hoc wireless network and a wired network, said access point comprising: a controller, for determining whether a wireless mobile node is affiliated with said access point; and a memory, for storing information pertaining to a routing path from said affiliated access point to said wireless mobile node, said routing path including at least one other of said nodes in said network between said affiliated access point and said wireless mobile node, and said information being provided by said wireless mobile node and said at least one other node in said routing path; said controller further operating to: identify and store in said memory a first routing path and associated information from said affiliated access point to said wireless mobile node; identify and store a second routing path and associated information from said affiliated access point to said wireless mobile node when said wireless mobile node moves by at least a certain amount; and send a message to said wireless mobile node along said first routing path when said wireless mobile node has not moved by said certain amount and by sending said message to said wireless mobile node along said second routing path when said wireless mobile node has moved by at least said certain amount. 12. An access point as claimed in claim 11, wherein: a frequency of occurrence of said second routing path identifying is based on a degree of mobility of said wireless mobile node. 13. An access point as claimed in claim 11, wherein: said memory stores said routing path information in a routing table. 14. An access point as claimed in claim 11, wherein: said routing path information is included in at least one data packet. 15. A method as claimed in claim 11, wherein: said message includes a data packet. 16. An ad-hoc wireless communication network, comprising: a plurality of nodes; and at least one access point for providing said nodes with access to at least one of a portion of said network and a wired network; at least one of said nodes being a wireless mobile node, wherein said wireless mobile node's location within said ad-hoc wireless communication network changes at a non-deterministic rate, and wherein said wireless mobile node sends data via a routing path to an affiliated access point with which said wireless mobile node is affiliated, said routing path including at least one other of said nodes between said affiliated access point and said wireless mobile node, and said data including an address of said wireless mobile node and a respective address for each said other node in said routing path; and said affiliated access point operating to: identify and store a first routing path and associated information from said affiliated access point to said wireless mobile node; identify and store a second routing path and associated information from said affiliated access point to said wireless mobile node when said wireless mobile node moves by at least a certain amount; and send at least one message to said wireless mobile node along said first routing path when said wireless mobile node has not moved by said certain amount and by sending said message to said wireless mobile node along said second routing path when said wireless mobile node has moved by at least said certain amount. 17. An ad-hoc wireless communication network as claimed in claim 16, wherein: said wireless mobile node includes said address of said wireless mobile node in said data when said wireless mobile node sends said data to said at least one other node; and each said at least one other node includes its said respective address in said data when it sends said data along said routing path. 18. An ad-hoc wireless communication network as claimed in claim 16, wherein: said data is configured as at least one data packet. 19. A method for locating a mobile node having a location which changes at a non-deterministic rate within an ad-hoc wireless network for communication of a message destined for the mobile node, the method comprising: at a node within the ad-hoc wireless network: receiving the message destined for the mobile node; determining if a current path to the mobile node is stored within the node; sending the message directly to a next hop node in a last recorded path stored within the node when the current path to the mobile node is not stored within the node; verifying whether the next hop node is the mobile node; and when the next hop node is not the mobile node, repeating the receiving, determining, and sending steps within the next hop node for a further next hop node and repeating the verifying and repeating steps. 20. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 19, wherein the node includes a routing table for storing one or more routing paths associated with each of a plurality of nodes, and wherein the determining step comprises querying the routing table for the current path and the last recorded path. 21. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 19, wherein the node comprises an access point, the method further comprising: registering the mobile device with the access point prior to the receiving step, wherein the registering includes providing a routing path to the mobile device. 22. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 19, the method further comprising: sending the message to the mobile node along the current path when the current path to the mobile node is stored within the node. 23. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 19, further comprising prior to the receiving step: receiving one or more routing information associated with the current path from the mobile node. 24. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 23, wherein the one or more routing information is contained within one or more routing information data packets received from the mobile node. 25. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 23, wherein the one or more routing information is contained within one or more data packets along with one or more other data information received from the mobile node via one or more intermediate nodes. 26. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 19, wherein the current path is deleted from the node when one or more of a group of events occurs selected from a group of events comprising a duration of time elapsed since the last recorded path, a speed of the mobile node, and the maximum range of the nodes and access points in the network. 27. A method for locating a mobile node within an ad-hoc wireless network for communication of a message destined for the mobile node as claimed in claim 19, wherein the next hop node is a mobile next hop node, the method further comprising prior to the sending the message directly to a next hop node step: determining whether a direct path to the next hop node is stored within the node; and when the direct path to the next hop node is not stored within the node, identify a previous hop node; identify another next hop node after the previous hop node in the recorded path; and send the message to the another next hop node after the previous hop node in the recorded path.