1. A new scheme to provide reliable transmission in optical burst switch networks
Yong-xiang Zhao, Chang-jia Chen, Yishuai Chen
Beijing Jiaotong University

2. Optical burst switch (OBS)
contention
few optical buffer
OBS assembles packets into burst to transfer in the optical core netwoks
A key challenge faced by OBS networks is how to resolve burst contention that happens when two or more incoming bursts contend for the same output line (in the same wavelength) at an optical switch.
There are few optical buffer in optical networks

3. Example: Switch E
Input 1
Dropped by contention
Input 2
Output
time

4. How to improve?
Coding?
Add redundancy

5. Random Coding + ACK Block When idle, coding and send ACK Next block
N raw bursts: {1,2,3}
When idle, coding and send
Random coding [1]: {2⊕1,2⊕3}
ID List
ACK
Receiving node ACK to sending edge
reliable transmission
Next block

6. Simulation Dumbbell networks … … Utilization? Change Number of nodes
0.1
Change Number of nodes … … 1
0.1

7. Performance

8. 2 Level Network
Fixed Number
Change Number of nodes

10. Reference
[1] T. Ho, M. M´edard, J. Shi, M. Effros, and D. Karger. On randomized network coding. In Allerton, 2003.