Method and system for maintaining routing between mobile workstations and selected network workstation using routing table within each router device in the network

• US 5,530,963 A
• Filed: 12/16/1993
• Issued: 06/25/1996
• Est. Priority Date: 12/16/1993
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Moore, Victor S., Van Duren, Richard G., Wu, David C.
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): MEKY, MOUSTAFA M
• Application Number:
  US08/168,693
• Time in Patent Office: 922 Days
• Field of Search: 395/200, 395/200.2, 395/200.09, 395/200.12, 395/200.15, 370/85.1, 370/95.1, 379/59, 455/33.1
• US Class Current: 709/243
• CPC Class Codes: H04L 12/4604 LAN interconnection over a backbone network, e.g. Internet, Frame Relay
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 40/246 Connectivity information discovery

Abstract

A method and system for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation wherein individual segments within the multisegment local area network are interconnected by a router device and wherein selected segments within the multisegment local area network include radio frequency transceivers adapted to provide a wireless communications link with mobile workstations. Each time communication is established between a mobile workstation and a selected workstation within the multisegment local area network via a radio frequency transceiver a routing table entry is established which identifies a segment location for the mobile workstation within a routing table associated with each router device within the multisegment local area network. A routing table entry is also established which identifies a segment location for the selected workstation within the routing table associated within each router device within the multisegment local area network in response to each attempt at establishment of communication between the selected workstation and the mobile workstation. Thereafter, all routing table entries which identify the segment location for a mobile workstation are automatically deleted in response to a termination of communications between the mobile workstation and the radio frequency transceiver. Routing path determination for communications between a mobile workstation and any workstation within the multisegment local area network may then be determined by reference to a routing table associated with each router device within a multisegment local area network without requiring the maintenance of routing path information at each workstation within the multisegment local area network.

Claims

1. A method for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation, wherein individual segments within said multisegment local area network are each interconnected utilizing a router device and wherein selected individual segments of said multisegment local area network include a radio frequency transceiver adapted to communicate with said mobile workstation, said method comprising the steps of:

coupling said mobile workstation to said multisegment local area network in response to an initiation of communication between said mobile workstation and a selected radio frequency transceiver within a segment within said multisegment local area network;

establishing a routing table only within each router device;

automatically establishing a routing table entry which identifies a location of said mobile workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said mobile workstation and a selected workstation within said multisegment local area network;

automatically establishing a routing table entry which identifies a location of said selected workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said selected workstation and said mobile workstation; and

automatically deleting each routing table entry which identifies a location of said mobile workstation within each routing table associated with a router device within said multisegment local area network in response to a termination of communication between said mobile workstation and said selected radio frequency transceiver by transmitting an address delete request to each router device within said multisegment local area network from said selected radio frequency transceiver in response to a termination of communication between said mobile workstation and said selected radio frequency transceiver, wherein a routing path between said selected workstation and said mobile workstation may be determined from a routing table associated with each router device within said multisegment local area network without requiring the maintenance of routing path information at each workstation within a set multisegment local area network.

2. The method for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation according to claim 1, wherein said step of automatically establishing a routing table entry which identifies a location of said mobile workstation within a routing table associated with each router device within said multisegment local area network further comprises the step of establishing a routing table entry which identifies a segment location for said mobile workstation and a proposed destination segment location for said selected workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said mobile workstation and said selected workstation.

3. The method for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation according to claim 1, wherein said step of automatically establishing a routing table entry which identifies a location of said selected workstation within a routing table associated with each router device within said multisegment local area network further comprises the step of establishing a routing table entry which identifies a segment location for said selected workstation and a proposed destination segment location for said mobile workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said selected workstation and said mobile workstation.

4. A system for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation, wherein individual segments within said multisegment local area network are each interconnected utilizing a router device and wherein selected individual segments of said multisegment local area network include a radio frequency transceiver adapted to communicate with said mobile workstation, said system comprising:

means for establishing a routing table only within each router device;

means for coupling said mobile workstation to said multisegment local area network in response to an initiation of communication between said mobile workstation and a selected radio frequency transceiver within a segment within said multisegment local area network;

means for automatically establishing a routing table entry which identifies a location of said mobile workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said mobile workstation and a selected workstation within said multisegment local area network;

means for automatically establishing a routing table entry which identifies a location of said selected workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said selected workstation and said mobile workstation; and

means for automatically deleting each routing table entry which identifies a location of said mobile workstation within each routing table associated with a router device within said multisegment local area network in response to a termination of communication between said mobile workstation and said selected radio frequency transceiver by transmitting an address delete request to each router device within said multisegment local area network from said selected radio frequency transceiver in response to a termination of communication between said mobile workstation and said selected radio frequency transceiver, wherein a routing path between said selected workstation and said mobile workstation may be determined from a routing table associated with each router device within said multisegment local area network without requiring the maintenance of routing path information at each workstation within a set multisegment local area network.

5. The system for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation according to claim 4, wherein said means for automatically establishing a routing table entry which identifies a location of said mobile workstation within a routing table associated with each router device within said multisegment local area network further comprises means for establishing a routing table entry which identifies a segment location for said mobile workstation and a proposed destination segment location for said selected workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said mobile workstation and said selected workstation.

6. The system for maintaining a routing path between a selected workstation within a multisegment local area network and a mobile workstation according to claim 4, wherein said means for automatically establishing a routing table entry which identifies a location of said selected workstation within a routing table associated with each router device within said multisegment local area network further comprises means for establishing a routing table entry which identifies a segment location for said selected workstation and a proposed destination segment location for said mobile workstation within a routing table associated with each router device within said multisegment local area network in response to an attempted initiation of communication between said selected workstation and said mobile workstation.