Lightweight multicast method and apparatus for data distribution service

1. A lightweight multicast apparatus, comprising:

a network congestion detection unit for multicasting packets to a plurality of subscriber node terminals, and detecting a cause of network congestion using a negative response message transferred from a relevant subscriber node terminal that could not receive the packets among the plurality of subscriber node terminals; and

a network recovery control unit for determining a recovery control policy depending on the cause of the congestion detected by the network congestion detection unit, and solving the cause of the congestion,

wherein the negative response message comprises a first subscriber congestion reason generated based on a cross-layered congestion tracking table of the relevant subscriber node terminal that could not receive the packets.

2. The lightweight multicast apparatus of claim 1 , wherein the network congestion detection unit receives an affirmative response message transferred from the relevant subscriber node terminal received the packets, and deletes information about the relevant subscriber node terminal transferred the affirmative response message from a recovery subscriber list.

3. The lightweight multicast apparatus of claim 2 , wherein the network congestion detection unit adds information about the relevant subscriber node terminal transferred the negative response message to the recovery subscriber list.

4. The lightweight multicast apparatus of claim 2 , wherein the network congestion detection unit receives second subscriber congestion reasons generated based on each of cross-layered congestion tracking tables of a neighboring intermediate node terminal and a neighboring subscriber node terminal included in a route for multicasting of the packets.

5. The lightweight multicast apparatus of claim 4 , wherein the second subscriber congestion reasons are generated by a neighboring intermediate node terminal and a neighboring subscriber node terminal included in a route for multicasting of the packets based on the negative response message or the affirmative response message transferred to the network congestion detection unit.

6. The lightweight multicast apparatus of claim 4 , wherein the network congestion detection unit detects the cause of the network congestion using the first subscriber congestion reason and the second subscriber congestion reasons.

7. The lightweight multicast apparatus of claim 6 , wherein the recovery control policy comprises a naive recovery policy, a fast recovery policy, and a proactive recovery policy.

8. The lightweight multicast apparatus of claim 7 , wherein the network recovery control unit determines whether the congestion is global congestion or local congestion depending on colors for levels of congestion flags included in the first subscriber congestion reason and the second subscriber congestion reasons.

9. The lightweight multicast apparatus of claim 8 , wherein the network recovery control unit selects the proactive recovery policy and relieves the global congestion when the congestion is the global congestion.

10. The lightweight multicast apparatus of claim 8 , wherein the network recovery control unit selects the naive recovery policy or the fast recovery policy and relieves the local congestion when the congestion is the local congestion.

11. The lightweight multicast apparatus of claim 4 , wherein each of the cross-layered congestion tracking tables comprises a route field for routes for multicasting of the packets, a field for a number of received packets, a field for a number of lost packets, a hop count field, a Media Access Control (MAC) delay time field, and a congestion flag field.

12. A lightweight multicast method, comprising:

multicasting packets to a plurality of subscriber node terminals;

receiving a negative response message transferred from a relevant subscriber node terminal that could not receive the packets among the plurality of subscriber node terminals;

detecting a cause of network congestion using the negative response message; and

determining a recovery control policy depending on the cause of the network congestion,

wherein the detecting the cause of the occurrence of the network congestion comprises,

detecting a first subscriber congestion reason included in the negative response message,

receiving second subscriber congestion reasons from a neighboring intermediate node terminal and a neighboring subscriber node terminal included in a route for multicasting of the packets, and

detecting the cause of the network congestion using the first and second subscriber congestion reasons.

13. A lightweight multicast method, comprising:

multicasting packets to a plurality of subscriber node terminals;

receiving a negative response message transferred from a relevant subscriber node terminal that could not receive the packets among the plurality of subscriber node terminals;

detecting a cause of network congestion using the negative response message;

determining a recovery control policy depending on the cause of the network congestion;

receiving an affirmative response message transferred from a relevant subscriber node terminal received the packets among the plurality of subscriber node terminals; and

deleting information about the relevant subscriber node terminal transferred the affirmative response message from a recovery subscriber list.

14. The lightweight multicast method of claim 13 , wherein the receiving the negative response message comprises adding information about the relevant subscriber node terminal transferred the negative response message to the recovery subscriber list.

15. The lightweight multicast method of claim 12 , wherein the recovery control policy comprises a naive recovery policy, a fast recovery policy, and a proactive recovery policy.

16. The lightweight multicast method of claim 15 , wherein the determining the recovery control policy comprises:

determining whether the congestion is global congestion or local congestion depending on colors for levels of congestion flags included in the first subscriber congestion reason and the second subscriber congestion reasons;

selecting the proactive recovery policy and then relieving the global congestion when the congestion is the global congestion; and

selecting the naive recovery policy or the fast recovery policy and then relieving the local congestion when the congestion is the local congestion,.

17. The lightweight multicast method of claim 12 , wherein the first subscriber congestion reason is generated based on a cross-layered congestion tracking table of the relevant subscriber node terminal that could not receive the packets.

18. The lightweight multicast method of claim 12 , wherein the second subscriber congestion reasons are generated based on each of cross-layered congestion tracking tables of the neighboring intermediate node terminal and the neighboring subscriber node terminal included in the route for multicasting of the packets.