Method and system for disseminating witness information in multi-hop broadcast network

• US 8,068,016 B2
• Filed: 02/04/2009
• Issued: 11/29/2011
• Est. Priority Date: 02/04/2009
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Toh, Chai Keong
• Primary Examiner(s): Lee; Benjamin C
• Assistant Examiner(s): PHAM, QUANG
• Application Number:
  US12/365,265
• Publication Number:
  US 20100194558A1
• Time in Patent Office: 1,028 Days
• Field of Search: 340/902, 340/905, 340/436, 340/539.1, 340/995.13, 340/425.5, 701117-119
• US Class Current: 340/425.5
• CPC Class Codes: G08G 1/162 event-triggered
• CPC Class Codes: G08G 1/205 Indicating the location of the monitored vehicles as destination, e.g. accidents, stolen, rental
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels

Abstract

Information related to a vehicular environment is disseminated in a multi-hop broadcast network of nodes. Vehicles and roadside units are equipped with the nodes. An event is sensed at a location by a source node. In response, zones are associated with respect to the location of the source node. Each zone is logically asymmetric and disjoint from the other zones. An alert message is broadcast, received, and then rebroadcast by other vehicles according to the locations of the vehicles in the zones. The nodes can also disseminate witness information.

Claims

1. A method for broadcasting witness information related to a vehicular environment using a multi-hop broadcast network of nodes, and wherein the nodes include a source node and a set of relay nodes in a plurality of zones, wherein each node includes a transceiver and a processor for performing steps of the method, and wherein the vehicular environment includes a plurality of vehicles, and wherein each vehicle is equipped with one of the nodes, comprising the steps of:

sensing an event at a location in the vehicular environment by the source node;

broadcasting, in response sensing the event, an alert message including the location of the event by the source node;

receiving the alert message in the set of relay nodes in the plurality of zones;

rebroadcasting the alert message by selected relay nodes selected by the distance to the event, and further comprising;

receiving the alert message and broadcasting witness messages by the selected relay nodes in response to receiving the alert message, wherein each witness message includes witness information related to the event, wherein the witness information depends on angles between the selected relay nodes and the source node with respect to a direction of travel of the vehicles, and vehicle identification number of the selected relay nodes.

2. The method of claim 1, wherein the witness information includes primary and secondary witness information.

3. The method of claim 1, wherein the witness information includes location information.

4. The method of claim 2, wherein the primary witness information is from the nodes within line of sight of the event.

5. The method of claim 1, wherein the witness information depends on a distance to the event.

6. The method of claim 3, wherein the locations of the nodes are stored as a “

1”

bit in a bit map grid, wherein a center bit in the grid corresponds to the location of the source node, and further comprising;

applying an exclusive OR to the bits in rows, columns and diagonals of the grid, and if the exclusive OR produces a “

1”

bit the corresponding node is in one of the vehicles occupied by a potential witness.

7. The method of claim 1, wherein the alert message includes fields for a location of the vehicle, a vehicle lane, a number of lanes open, a travel direction, a last exit, and a time of the event.

8. The method of claim 1, wherein the alert message is filtered.

9. The method of claim 1, wherein the alert message is fused with other alert message.

10. The method of claim 1, further comprising:

receiving the alert message and the witness messages in a stationary roadside unit equipped with one of the nodes.

11. The method of claim 10 wherein the stationary roadside unit relates the alert and witness messages to an emergency response agency.