High-Capacity Time-Domain Wavelength Interleaved Networks

Time-domain wavelength interleaved network (TWIN) is an elegant and cost-effective all-optical network designed by a group of researchers in Bell Labs. It emulates fast optical switching via fast tunable lasers at the network edge, so it does not need optical switching and buffering in the network core. TWIN can be upgraded to provide larger capacity by using more receivers at the nodes, where capacity is the aggregate data rate supported by the network. In this paper, we focus on making this upgrade resource-effective. Specifically, we exploit and optimize wavelength reuse so that the resulting network, called high-capacity TWIN (HC-TWIN), can better utilize its available resources to provide larger capacity while retaining the appealing advantages of TWIN. We formulate the problem of optimizing HC-TWIN, prove its NP-hardness, and design an efficient three-stage algorithm to solve it. Simulation results demonstrate that 1) HC-TWIN can provide larger capacity by realizing larger degree of wavelength reuse and 2) the three-stage algorithm can find optimal or close-to-optimal solutions.