MAC forwarding method for multi-hop routing in communication system between vehicles

• US 20070110067A1
• Filed: 07/13/2006
• Published: 05/17/2007
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: Carrum Technologies, LLC (Pratima Instruments, LLC)
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Hyun, Chae, Jong-Suk, Lee, Hyuk-Joon, Pyo, Cheol-Sig, Shin, Chang-Sub, Cho, Han-Byeog
• Granted Patent: US 7,933,271 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04W 40/26 for hybrid routing by combining proactive and reactive routing

Abstract

Provided is a Media Access Control (MAC) forwarding method for multi-hop routing in a communication system between vehicles. The method includes the steps of: a) receiving a frame from all nodes and checking whether there are duplicate frames; b) partly updating forwarding cache table (FCT) information, or updating SNT information and checking whether a destination address is a corresponding node; c) updating the FCT information, transmitting an Ack signal and transferring the frame to the upper layer, or searching whether the destination address is registered as “d_addr”; d) updating the FCT information and transmitting a delay ACK frame or checking whether the transmitted frame is a flooding frame; and e) updating the FCT information, checking whether the other node does not transmit the “d_ack” and inserting a flooding frame, otherwise, updating the FCT information and abandoning the frame.

Claims

1. A Media Access Control (MAC) forwarding method for multi-hop routing in a communication system between vehicles, comprising the steps of:

a) receiving frames in nodes and checking whether there are duplicate frames;

b) at each node partly updating forwarding cache table (FCT) information when there are duplicate frames or updating a sequence number table (SNT) information when there is no duplicate frame and checking whether a destination address is the node'"'"'s own address;

c) when the destination address is the node'"'"'s own address, updating the FCT information transmitting an Ack signal and transferring the frame to the upper layer, or when the destination address is not the node'"'"'s own address, searching whether the destination address is registered as “

d_addr”

in the FCT;

d) when the destination address is registered, updating the FCT information and transmitting a delay ACK frame, which is “

d_ack”

, or when the destination address is not registered in the FCT, checking whether the transmitted frame is a flooding frame; and

e) updating the FCT information, checking whether there is no other node transmitting the “

d_ack” and

inserting a flooding frame when the transmitted frame is the flooding frame, otherwise, updating the FCT information and abandoning the frame.

2. The method as recited in claim 1, wherein the frame to be transmitted from each node is selected between implicit unicast frame (IUF) and the flooding frame based on whether the destination address is on a forwarding table of the node.

3. The method as recited in claim 1, wherein in the step c), the flooding frame is transmitted when there is no destination address in the forwarding table of the node, or otherwise the IUF is transmitted.

4. The method as recited in claim 1, wherein in the step b), each node receiving the frame compares the transmitted frame with the flooding table of the node, and transmits the Ack signal in case that the node is the destination.

5. The method as recited in claim 1, wherein in the step b), the node transmits the “

d_ack”

signal in case that the node is on the list.

6. The method as recited in claim 1, wherein in the step b), the node is forwarded to the flooding frame in case that the node is not the destination and is not on the list.

7. The method as recited in claim 1, wherein the frame defines Type and Sub-Type fields and the data type in the Type field is the IUF and the data type in the Sub-Type field is the flooding frame.

8. The method as recited in claim 7, wherein the MAC forwarding uses 4 address fields including a transmitter address, a receiver address, a source address and a destination address, and the MAC Forwarding is performed on the receiver address based on a broadcasting address.