WIRELESS NETWORKED MESSAGE ROUTING

• US 20030043763A1
• Filed: 07/29/1998
• Published: 03/06/2003
• Est. Priority Date: 07/29/1997
• Status: Active Grant

• Current Assignee: Philips Lighting Holding BV (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: GRAYSON, PAUL D
• Granted Patent: US 6,665,278 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04W 40/32 for defining a routing cluster membership
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A wireless communication system includes a number of devices to be clustered for the exchange of data and control message packets. Each node (ON, IN1 to IN5) has a unique address within the cluster and is arranged to accept only messages transmitted to it. A dynamic re-routing technique is provided whereby a message packet (M) not received by its target node is detected and re-routed via one or a succession of other nodes of the cluster until either transmission is successful or a predetermined number of failed attempts has been made. The system provides distributed control and intelligence with intermediate nodes for re-routing being selected randomly and current count values for unsuccessful transmission attempts being included within the transmitted packet.

Claims

1. A wireless communications system comprising a plurality of nodes clustered for the exchange of data and control message packets, each node having a unique address within the system, and being arranged to ignore received messages not containing their own node address, and each being arranged to generate and transmit an acknowledgement message to the originating node of a data packet received directly, characterised in that each node further comprises a store holding a node address for each other node of the system, each node being arranged, on determining lack of receipt of an acknowledgement message for a message packet transmitted to a target node, to select a further node address from the store and transmit the said message packet to said further node as a re-routed message packet, each node being configured to identify the original target of a received re-routed message packet and to transmit said re-routed message packet to its original target.

2. A system as claimed in claim 1, wherein each node is configured to generate and transmit an acknowledgement message to the transmitting node of a successfully received message packet, with each node re-transmitting a message packet a predetermined number of times to a destination node if an acknowledgement is not received within a predetermined period.

3. A system as claimed in claim 2, wherein each node is operable to select, on determining the lack of a received acknowledgement message for a re-routed message packet, a still further node address from store, other than those of the target node and message originating node, and to transmit said message packet to said still further node as a re-routed message.

4. A system as claimed in claim 3, including means to limit the number of re-routed transmissions of a message packet to a pre-determined number of re-routed transmissions.

5. A system as claimed in claim 4, wherein each message packet carries a data field reserved to indicating unsuccessful transmission of said message packet as a re-routed packet, each node having means to modify said data field to increment the value on determination that no acknowledgement message has been received following transmission of the packet as a re-routed message packet.

6. A device for use as a node within a system as claimed in claim 1, said device comprising control means coupled with an address data store and a transceiver, the control means being operable to format data packets according to a predetermined protocol and transmit said packets via the transceiver, to extract data from such packets received via the transceiver, said device having an identifying address and being configured to ignore all received message packets not including said address.