Flooding method in ad-hoc network

• US 20060045066A1
• Filed: 08/31/2005
• Published: 03/02/2006
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Choi, Soon-jin, Jeong, Min-seop, Lim, Yu-jin, Kim, Il-whan, Kang, Chung-gu
• Granted Patent: US 7,532,598 B2
• Time in Patent Office: Days
• US Class Current: 370/351
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/32 Flooding denial of service attacks H04L63/1458
• CPC Class Codes: H04W 40/08 based on transmission power

Abstract

A method for flooding a route request packet that is received at a node in a communication system constructed of at least three nodes including a source node that requests to establish a route and a destination node that receives the route request. One of a plurality of levels having different transmission periods is determined using a strength of a received signal of a measured packet. A transmission start point is selected at the determined level, and it is determined whether a route request packet is re-received before the selected transmission start point. The received packet is broadcast at the selected transmission start point when the packet is not re-received. The transmission start point is randomly selected within the transmission period or at the level in consideration of the number of the connected nodes.

Claims

1. A method for flooding a route request packet that is received at a first node in a communication system constructed of at least three nodes including a source node that requests to establish a route and a destination node that receives the route request, the method comprising:

determining one of a plurality of levels having different transmission periods using a strength of a received signal of a measured packet;

selecting a transmission start point at the determined level and determining whether a route request packet is re-received before the selected transmission start point; and

broadcasting the received packet at the selected transmission start point when the packet is not re-received.

2. The method according to claim 1, wherein whether the route request packet is re-received is determined by comparing a source address and a destination address.

3. The method according to claim 2, wherein the signal strength of the received packet is measured only when a destination address in the received packet is different from an address of the node.

4. The method according to claim 2, wherein a received packet is dropped if the received packet is the re-received route request packet.

5. The method according to claim 1, wherein the first node stores information relating to the strength of the received signal by levels.

6. The method according to claim 5, wherein a low signal strength has a relatively earlier transmission start point than a high signal strength.

7. The method according to claim 6, wherein transmission periods at each of the levels are defined to a uniform size.

8. The method according to claim 1, wherein the transmission periods at each of the levels do not overlap with each other.

9. A method for selecting a transmission start point to flood a route request packet received at a node in a communication system constructed of at least three nodes including a source node that requests to establish a route and a destination node that receives the route request, the method comprising:

determining one of a plurality of levels having different transmission periods using a strength of a received signal of a measured packet; and

selecting a transmission start point at the determined level based on a number of connected nodes.

10. The method according to claim 9, wherein the node having a greater number of connected nodes selects an earlier transmission start point.

11. The method according to claim 9, wherein the selection of the transmission start point comprises:

re-setting a transmittable period within a transmission period in accordance with the number of the connected nodes; and

randomly selecting a transmission start point within the re-set transmittable period.

12. The method according to claim 11, wherein a start point of the transmittable period is the same as a start point of the transmission period, and an end point of the transmittable period is determined based on the number of the connected nodes.

13. The method according to claim 12, wherein a greater number of the connected nodes indicates a shorter transmittable period.

14. The method according to claim 13, wherein the transmittable period is determined between CW_K,min and

${\mathrm{CW}}_{K,\min }+\frac{d}{R},$

wherein CW_K,min is a start point of a K-th transmission period, d is an arbitrary positive constant, and R is the number of the connected nodes.