LTS PMD Project Overview

The work on this project can be divided into several main activity areas:

1. Sensor design, construction, and testing

This will be the initial focus, as the sensor design may impact the eventual software implementation. Several different sensor schemes that have been demonstrated in the literature will be evaluated, based on both published results and numerical simulations performed at UMBC. Once a design is chosen, we will construct a prototype version, and test the sensor at the UMBC laboratory using a DGD emulator to simulate transmission impairments.

2. Software development

Once the sensor design is finalized, efforts will begin to modify the DRAGON software. The modified software will be able to poll the sensor output, compare it to a pre-programmed threshold level, and alert the routing components when the threshold level is crossed, preventing any newly created connections from using the PMD-impaired link. This work will be performed by software engineers at MAX.

3. Construction and characterization of a network testbed

The final demonstration experiments will take place on an installed fiber link connecting the laboratories at UMBC and MAX. The fiber link will be characterized for transmission loss, chromatic dispersion, and PMD. The equipment for each end point must be collected and installed, including ethernet switches, 1 and 10 Gb/s optical transceivers, amplifiers, and add-drop multiplexers. Finally, the link performance will be characterized.

4. Proof-of-principle demonstration

Finally, the sensor and DGD emulator will be installed at either end of the link, and modified DRAGON code will be ready for installation. We will perform a series of measurements which test the system performance under different PMD impairments levels, and show that when the sensing protocol is used, the system performance remains satisfactory, even for very high impairment levels which would normally disable traffic.