EP0578041A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Shortcut network layer routing for mobile hosts
Assignee: International Business Machines Corp
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Filing: 1993-06-21
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Granted: —
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Expires: 2013-06-21
Abstract
Abstract A method for routing a packet of information between two hosts that are coupled to a network. Each of the hosts have a unique network address, and at least one of the hosts is a mobile host (10) that does not have a fixed network coupling location. The method includes a first step of (a) transmitting a packet from the mobile host to a second, destination host on the network through a wireless link that is established between the mobile host and a base access station (12) that serves a current physical location of the mobile host. The base access station is coupled to the network via a subnetwork (LAN) (14), and the packet includes a first Internet Protocol (IP) Loose Source Routing (LSR) option that includes a network address of the base access station. A second step (b) receives with the destination host the packet that includes the first IP LSR option. A third step (c) transmits a further, reply packet from the second host to the mobile host via the base access station in accordance with a path reversal technique wherein the reply packet includes a second IP LSR option that specifies as a first Routing address the network address of the base access station. As a result, the reply packet is directed through the network to the base access station that serves the current physical location of the mobile host, and an optimal, fast routing of the packet is achieved without involving intermediate gateways (16, 18).
Inventors
- 👤 Charles Edward Perkins
- 👤 Jacob Yakov Rekhter
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 18:42
CPC Classifications
H; H04; H04W; H04W8/00; H04W8/02; H04W8/08; H04W8/082; H04L; H04L9/00; H04L9/40; H04W40/00; H04W40/02; H04W40/24; H04W40/28; H04W80/00; H04W80/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
217 words
A method for routing a packet of information between two hosts that are coupled to a network, each of the hosts having a unique network address, wherein at least one of the hosts is a mobile host that does not have a fixed network coupling location, comprising the steps of: transmitting a packet from the mobile host to a second, destination host on the network through a wireless link that is established between the mobile host and a base access station that serves a current physical location of the mobile host, the base access station being coupled to the network via a subnetwork, the packet including a first Loose Source Routing (LSR) option that includes a network address of the base access station; receiving with the destination host the packet that includes the first LSR option; and transmitting a further packet from the second host to the mobile host via the base access station and the wireless link in accordance with a path reversal technique such that the further packet includes a second LSR option that includes a network address of the base access station that was included within the first LSR option, whereby the further packet is directed through the network to the base access station that serves the current physical location of the mobile host.
Claim 2
Independent Claim
217 words
A method for routing a packet of information between two hosts that are coupled to a network, each of the hosts having a unique network address, wherein at least one of the hosts is a mobile host that does not have a fixed network coupling location, comprising the steps of: transmitting a packet from the mobile host to a second, destination host on the network through a wireless link that is established between the mobile host and a base access station that serves a current physical location of the mobile host, the base access station being coupled to the network via a subnetwork, the packet including a first Loose Source Routing (LSR) option that includes a network address of the base access station; receiving with the destination host the packet that includes the first LSR option; and transmitting a further packet from the second host to the mobile host via the base access station and the wireless link in accordance with a path reversal technique such that the further packet includes a second LSR option that includes a network address of the base access station that was included within the first LSR option, whereby the further packet is directed through the network to the base access station that serves the current physical location of the mobile host.
Claim 3
Dependent Claim
95 words
Method as set forth in Claim 1, further comprising the steps of: in response to the mobile host establishing a wireless link with a second base access station on the same or a different subnetwork, transmitting the network address of the second base access station from the mobile host to a mobile router that is coupled between the subnetwork and the network, the transmission including the network address of the mobile host; and maintaining, with the mobile router, the network address of the mobile host and the network address of the second base access station.
Claim 4
Dependent Claim
34 words
Method as set forth in Claim 2, including a step of transmitting to the network from the mobile router the network address of the mobile router and the network address of the mobile host.
Claim 5
Dependent Claim
179 words
Method as set forth in Claim 1, 2 or 3 wherein the step of transmitting the further packet includes the steps of: receiving the further packet with the base access station; and determining if the mobile host is currently located within the physical area served by the base access station; if it is determined that the mobile host is currently located within the physical area served by the base access station, forwarding the further packet from the base access station over the wireless link to the mobile host; else if it is determined that the mobile host is not currently located within the physical area served by the base access station, and if it is determined that the second LSR option includes no further intermediate addresses, forwarding the further packet from the base access station over the subnetwork to a mobile router that is coupled between the subnetwork and the network; and forwarding the further packet from the mobile router to a second base access station that serves a physical location within which the mobile host is currently located.
Claim 6
Dependent Claim
161 words
A method as set forth in Claim 2, 3 or 4 wherein, in response to a reception of a packet by the mobile router from the network, the packet not including an LSR option and having the network address of a mobile host as a destination address, the method includes the steps of: converting the received packet into a packet that includes an LSR option, the LSR option being provided by the mobile router with the network address of the mobile host, the received packet further being provided with a destination address of a base access station that is serving the physical location within which the mobile host is currently located; forwarding the converted packet from the mobile router to the base access station that serves the physical location within which the mobile host is currently located; and receiving the converted packet and forwarding the received converted packet from the base access station over the wireless link to the mobile host.
Claim 7
Dependent Claim
213 words
Method as set forth in Claim 4 or 5 wherein, if it is determined that the mobile host is not currently located within the physical area served by the base access station, the step of forwarding the further packet from the base access station over the subnetwork to the mobile router includes an initial step of deleting the address of the base access station from the further packet, or if it is determined that the mobile host is currently located within the physical area served by the base access station, the step of forwarding the further packet from the base access station over the wireless link to the mobile host includes an initial step of advancing an LSR option address pointer beyond a last LSR option address, or if it is determined that the mobile host is not currently located within the physical area served by the base access station, the method includes a step of: deleting the address of the base access station from the further packet; and, if it determined that the LSR option includes a further address other than the address of the mobile host, the method further includes the steps of: advancing a LSR option address pointer to the next address; and forwarding the packet to the next address.
Claim 8
Independent Claim
198 words
A method for routing a packet of information between two hosts that are coupled to a network, each of the hosts having a unique network address, wherein at least one of the hosts is a mobile host that does not have a fixed network coupling location, comprising the steps of: in response to a reception of a packet from the network by a mobile router, the packet not including an LSR option and having the network address of a mobile host as a destination address, converting the received packet into a packet that includes a LSR option, the LSR option being provided by the mobile router with the network address of the mobile host, the received packet further being provided with a destination address of a base access station that is serving with a wireless communication link a physical location within which the mobile host is currently located; forwarding the converted packet from the mobile router to the base access station that serves the physical location within which the mobile host is currently located; and receiving the converted packet and forwarding the received converted packet from the base access station over the wireless link to the mobile host.
Claim 9
Independent Claim
198 words
A method for routing a packet of information between two hosts that are coupled to a network, each of the hosts having a unique network address, wherein at least one of the hosts is a mobile host that does not have a fixed network coupling location, comprising the steps of: in response to a reception of a packet from the network by a mobile router, the packet not including an LSR option and having the network address of a mobile host as a destination address, converting the received packet into a packet that includes a LSR option, the LSR option being provided by the mobile router with the network address of the mobile host, the received packet further being provided with a destination address of a base access station that is serving with a wireless communication link a physical location within which the mobile host is currently located; forwarding the converted packet from the mobile router to the base access station that serves the physical location within which the mobile host is currently located; and receiving the converted packet and forwarding the received converted packet from the base access station over the wireless link to the mobile host.
Claim 10
Dependent Claim
154 words
Method as set forth in Claim 7 wherein the step of receiving the converted packet includes the steps of: determining if the mobile host is currently located within the physical area served by the base access station; if it is determined that the mobile host is currently located within the physical area served by the base access station, forwarding the converted packet from the base access station over the wireless link to the mobile host; else if it is determined that the mobile host is not currently located within the physical area served by the base access station, and if it is determined that the LSR option includes no further intermediate addresses, forwarding the converted packet from the base access station over to the mobile router; and forwarding the converted packet from the mobile router to a second base access station that serves a physical location within which the mobile host is currently located.
Claim 11
Dependent Claim
18 words
Method as set forth in Claim 7 wherein the network address and the destination address are Internet addresses.
Claim 12
Dependent Claim
20 words
Method as set forth in Claim 7 wherein the steps of receiving and forwarding are accomplished using an Internet Protocol.
Claim 13
Dependent Claim
22 words
Method as set forth in any one of the Claims 1 to 9 wherein the wireless link is an infrared radiation link.
References Cited (Backward Citations)
No citation records indexed.
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