METHOD AND APPARATUS FOR REDUCING THE LENGTH OF A PACKET STORM IN A WIRELESS MESH NETWORK

• US 20170034760A1
• Filed: 04/02/2015
• Published: 02/02/2017
• Est. Priority Date: 04/16/2014
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting Holding BV (Signify N.V.)
• Inventors: GE, XIAODONG
• Granted Patent: US 10,321,379 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/025 Updating only a limited number of routers, e.g. fish-eye update
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/023 Limited or focused flooding to selected areas of a network
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A broadcast transmission will generate a packet storm in a mesh network, which will last for a very long time and block the network for other traffic. There is a parameter in a broadcast control mechanism named radius which controls the duration of the packet storm. The invention proposes to dynamically select the smallest radius to reduce the packet storm to a minimum, by reporting the smallest possible radius parameter for the broadcast control mechanism. Each device or node of the network comprises a neighbor table for tracking which of its neighboring devices or nodes has successfully relayed the broadcast transmission. Additionally, each device or node comprises a broadcast transaction table to keep a record of any new broadcast transmission or transaction that is either initiated locally or received from a neighboring device or node. Each broadcast transmission comprises a so called radius parameter R which indicates an allowed number of hops through the mesh network before the broadcast transmission is discarded. The mechanism to report broadcast status may be realized in an exemplary embodiment of the invention by adding two new tables to track broadcasting status from neighboring devices: the child table, to which the concerned network node or network device has transmitted or relayed a broadcast transmission, and the broadcast listening table; and by adding three fields into the broadcast transaction table: the radius, report interval and report timeout; and also by adding two new parameters into broadcast message itself: report interval and report timeout.

Claims

1. An apparatus for controlling information broadcast in a wireless mesh network, the apparatus comprising:

at least one device table for tracking which device has successfully relayed a broadcast transmission;

at least one broadcast table for keeping a record of any new broadcast transmission that has been initiated by said apparatus or received from a neighboring device;

wherein each broadcast transmission includes a radius parameter, which indicates an allowed number of hops through said mesh network before the broadcast transmission is discarded;

wherein the apparatus is adapted to add to a new broadcast transmission a radius parameter, or to reduce the radius parameter, by one when a received broadcast transmission is forwarded; and

wherein the apparatus is adapted to check information provided in the device table and the broadcast table so as to report to a message initiator a maximum repetition number representative of the number of hops which was necessary to transmit the message.

2. The apparatus of claim 1, wherein the at least one device table includes a neighbor table for tracking which neighboring device, which is a device within a transmission or reception range of the apparatus, has successfully relayed a broadcast transmission;

and wherein the at least one broadcast table includes

a broadcast transaction table for keeping a record of any new broadcast transmission that has been initiated by said apparatus or received from a neighboring device.

3. The apparatus of claim 2, wherein the at least one device table includes

a child table for tracking which child device, which is a device to which said apparatus has transmitted a broadcast transmission, has successfully relayed the broadcast transmission;

and wherein the at least one broadcast table includes

a broadcast listening table for keeping a record of any new broadcast transmission that has been received by a child device.

4. The apparatus of claim 2, wherein the apparatus is adapted to compare the radius parameter, of a new broadcast transmission with a previous one when updating an existing entry in the broadcast transaction table and to record the smaller one in the broadcast transaction table.

5. The apparatus of claim 3, wherein the apparatus is adapted to check a report interval, provided for each recorded broadcast message of the broadcast transaction table, to search for the same broadcast message in the broadcast listening table when the report interval has been reached, and to flag all child devices having received the same broadcast message so at to form a status report message.

6. The apparatus of claim 3, wherein the apparatus is adapted to check a report timeout, provided for each recorded broadcast message of the broadcast transaction table, to search for the same broadcast message in the broadcast listening table when the report timeout has expired, and to flag all child devices having received the same broadcast message so at to form a status report message.

7. The apparatus of claim 1, wherein the apparatus is adapted to retransmit a new broadcast transmission if after a timeout any of the devices listed in the device table has not relayed the new broadcast transmission.

8. The apparatus of claim 1, wherein the apparatus is adapted to search for a message with the shortest radius parameter, in the broadcast table if a status report message in generated, to extract a sending address of the message with the shortest radius parameter, and to send the status report message to the extracted sending address using a unicast transmission.

9. The apparatus of claim 3, wherein, if a status report message has been received by said apparatus, the apparatus is adapted to search for the same message with the shortest radius parameter, in the broadcast transaction table if there is a child device having the same message and to extract a device address of the message with the shortest radius parameter, or to discard the status report message if there is no such message in the broadcast transaction table.

10. The apparatus of claim 1, wherein the apparatus is adapted to compare all values of the radius parameter, in the broadcast table for all devices having received the same broadcast message and to insert the largest repetition number in a status report message.

13. A mesh network comprising a plurality of network nodes comprising an apparatus according to claim 1.

11. An apparatus for initiating information broadcast in a wireless mesh network, said apparatus being adapted to extract from at least one received status report message a maximum repetition number which indicates the number of hops necessary to reach a device, and to select the largest value of extracted maximum repetition number as a calibration value to generate a radius parameter to be inserted into a broadcast transmission, said radius parameter being indicative of an allowed number of hops through said mesh network before the broadcast transmission is discarded.

12. The apparatus of claim 11, wherein the apparatus is adapted to initiate a re-calibration if it determines that a device of the wireless mesh network is not able to receive a broadcast transmission or that the number of devices not able to receive the broadcast transmission decreases, and wherein the apparatus is adapted to start re-calibration by selecting an initial value for the radius parameter that is larger than a current value and smaller than a default value.

14. A method of controlling information broadcast in a wireless mesh network, the method comprising, at an apparatus:

tracking which device has successfully relayed a broadcast transmission with at least one device table;

recording any new broadcast transmission that has been initiated by said apparatus or received from a neighboring device with at least one broadcast table; and

adding to a new broadcast transmission a radius parameter, which indicates an allowed number of hops through said mesh network before the broadcast transmission is discarded, or reducing the radius parameter, by one when a received broadcast transmission is forwarded, wherein each broadcast transmission includes the radius parameter;

checking the recorded broadcast transmissions; and

determining and reporting to a message initiator a maximum repetition number, representative of the number of hops which was necessary to transmit the message.

15. A method of initiating information broadcast in a wireless mesh network, the method comprising, at a message initiator:

extracting from at least one received status report message a maximum repetition number which indicates the number of hops necessary to reach a device, and

selecting the largest value of extracted maximum repetition number as a calibration value to generate a radius parameter to be inserted into a broadcast transmission, said radius parameter being indicative of an allowed number of hops through said mesh network before the broadcast transmission is discarded.