1. UCB Notes on Optical Networks Jean Walrand EECS

2. UCB Outline Dynamic Configuration? Wavelength Assignment Too Much Bandwidth?

3. UCB Dynamic Configuration? Consider IP/ON:

4. UCB Dynamic Configuration? (cd) Model: Note: Assuming TDM of the two configurations, we can get any combination of service rates that add up to 3m. However, the optimal scheduling is dynamic. In the case where the two arrival rates are equal, it is shown above. Question: How much do we gain?

5. UCB Wavelength Assignment Example 1 N users. Each user listens to some wavelengths and transmits on others. There are W wavelengths. N users choose among W to send and N users choose among W to receive => W 2N choices. There are N! connection matrices. Hence W 2N > N! > (N/e) N => W > (N/e) 0.5 Example: W = 160 => N < e(160) 2 = 70,000.

6. UCB Wavelength Assignment (cd) Example 1 (cd) Constructing a network to achieve this bound: Full broadcast. However, this is not practical. Introducing constraints limits N.

7. UCB Wavelength Assignment (cd) Example 2 Selecting wavelengths: Greedy: lowest from L to R 1 2 1 3 2 Note: For general networks, a greedy algorithm is not optimal. In fact, an optimal algorithm is known to be NP hard.

8. UCB Too Much Bandwidth? Assumptions: 84M houses 20Mbps incoming, 2Mbps outgoing / house Assume 80% incoming traffic is coming from local server, rest from anywhere Outgoing traffic goes anywhere Problem: Design a network: switches, links, …

9. UCB Too Much Bandwidth? (cd) Rough attempt: 12 metro areas of 7M houses each Into each area: 11/12 of 4Mbpsx7M = 26Tbps Questions: Include multicast model Design network (optical core + routers)