Burst scheduling methods in optical burst switching system
View Patent ↗Provided is a burst scheduling method in an Optical Burst Switching (OBS) system in which a plurality of nodes are connected through a mesh-type network. When a TDB which has used many network resources via a plurality of nodes and an SHG burst generated in a previous node, among bursts including BCPs transmitted from the previous node, compete in a current node so as to occupy a specific output channel, scheduling is performed to cause the TDB to have a higher priority than the SHG burst such that the corresponding output channel is occupied. Therefore, it is possible to minimize a burst loss in a network node, thereby enhancing the overall system performance.
1. A computer program encoded on a non-transitory computer readable medium comprising a burst scheduling method in an Optical Burst Switching (OBS) system in which a plurality of nodes are connected through a mesh-type network, the method comprising:
(a) determining, using a Burst Control Packet (BCP) transmitted from a previous node, whether an input burst is a Transit Data Burst (TDB) or an Several Hop Going (SHG) burst;
(b) when the input burst is a TDB as a determination result of step (a) and an output channel to be used is already occupied by a specific SHG burst, reassigning the corresponding output channel such that the corresponding TDB burst occupies the output channel; and
(c) when the input burst is an SHG burst as a determination result of step (a) and an output channel to be used is already occupied by another burst, discarding the corresponding SHG burst.
2. The burst scheduling method according to claim 1 further comprising when the output channel to be used is occupied by another TDB in step (b), the corresponding input TDB burst is discarded.
3. The burst scheduling method according to claim 1 further comprising when the output channel to be used is available in step (b), the corresponding burst occupies the output channel.
4. The burst scheduling method according to claim 1 , wherein in step (b), if the output channel is occupied by the SHG burst, the SHG burst is removed from the output channel before the reassigning, and a retransmission request signal is transmitted to the previous node such that the corresponding SHG burst is retransmitted.
5. The burst scheduling method according to claim 1 further comprising in step (c), when the output channel to be used is available, the corresponding SHG burst occupies the output channel.
6. The burst scheduling method according to claim 1 , wherein in step (c), when the corresponding SHG burst is discarded, a retransmission request signal is transmitted to the previous node such that the corresponding SHG burst is retransmitted.
7. A computer program encoded on a non-transitory computer readable medium comprising a burst scheduling method in an Optical Burst switching (OBS) system in which a plurality of nodes are connected through a mesh-type network, further comprising when a TDB which has used many network resources via a plurality of nodes and an SHG burst generated in a previous node, among bursts including BCPs transmitted from the previous node, compete in a current node so as to occupy a specific output channel, scheduling is performed to cause the TDB to have a higher priority than the SHG burst such that the corresponding output channel is occupied.