Wireless master-slave distributed communications network

• US 20020173321A1
• Filed: 05/15/2002
• Published: 11/21/2002
• Est. Priority Date: 05/17/2001
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Marsden, Ian A., Marshall, Paul R.
• Granted Patent: US 8,359,051 B2
• Time in Patent Office: Days
• US Class Current: 455/500
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A master-slave distributed communications network comprises a master node (10), a plurality of slave nodes (12 to 22), and links (VL) operatively interconnecting the slave nodes and the master node in accordance with a routing plan. Each slave node has means for storing an address of the next node in the routing plan for a message to be routed on an uplink to the master node and when sending a data packet to the master node it appends the prestored address and forwards the data packet to the next node. If the next node is not the master node, it, in turn, adds the prestored address of the next following slave node to the data packet thus lengthening the data packet and re-transmits it, and so on until the data packet reaches the master node.

For a downlink message, the master node (10) using a prestored routing table includes in the data packet the addresses of all the slave nodes on the selected route. As the data packet is progressed from slave node to slave node, the address of each slave node which has forwarded the data packet is deleted thus shortening the overall length of the data packet.

Claims

1. A master-slave distributed communications network comprising a master node and a plurality of slave nodes, the master node and the slave nodes being operatively interconnected, wherein each slave node has means for storing an address of the next node in a route of a message to the master node.

2. A network as claimed in claim 1, characterised in that each slave node has means for appending the stored address of the next node in a route of a message to be sent to the master node.

3. A method of operating a master-slave distributed network comprising a master node and a plurality of slave nodes, the master node and the slave nodes being operatively interconnected, wherein a slave node wishing to send a data packet to the master node includes in the data a prestored address of the next node in a route to the master node and transmits the data packet.

4. A method as claimed in claim 3, characterised in that a slave node receiving a data packet includes in the data packet the stored address of the next node in the route to the master node before transmitting the data packet.

5. A method as claimed in claim 3 or 4, characterised by the master node including addresses of the slave nodes on a route to a destination slave node in a data packet to be transmitted.

6. A method as claimed in claim 5, characterised by a slave node receiving a data packet removing its own address from the data packet and transmitting the altered data packet.

7. A method as claimed in any one of claims 3 to 6, characterised by a new slave node transmitting an invitation message requesting routing information from in-range slave nodes, the new slave node receiving routing information and determining which of the in-range slave nodes is the preferred node in its route to the master node and storing its address.

8. A method as claimed in any one of claims 3 to 7, characterised by, after an alteration in the network, slave nodes re-examining their routes to the master node and in response to a slave node finding that its route does not comply with predetermined routing criteria, that slave node setting-up a new route by storing the address of the next node in its route.

9. A method as claimed in claim 3, 4 or 5, characterised by a new slave node transmitting a “

request route to master”

message with the number of hops set to a predetermined minimum value and in response to not receiving a reply repeating the transmission of the “

request route to master”

message with the number of hops increased in value.

10. A slave station for use as a slave node in a master-slave distributed communications network including a master node and a plurality of slave nodes, the slave station comprising transceiving means for communicating with at least one of the master node and the plurality of slave nodes, first memory means for storing the address of the slave station, second memory means for storing the address of the next node in a route to the master node, and processing means coupled to the transceiving means and the first and second memory means for adding the address of the said next node to a data packet to be transmitted to the master node.

11. A slave station as claimed in claim 10, characterised in that the processing means deletes the address of the slave station which is present in a data packet originating from the master node and received by the slave station.

12. A master station for use in a master-slave distributed communications network including the master station and a plurality of slave stations, the master station comprising transceiving means for communicating with the plurality of slave stations, memory means for storing routing data, and processing means for compiling routing information from the stored routing data and for adding the compiled routing information to a data packet, the routing information comprising the address of a destination slave station and, where applicable, the address of the or each intermediate slave station(s) through which the data packet will be passed.