On the effectiveness of optical parallel transmission in IP offloading

The use of dynamic optical circuits for IP offloading, also referred to as optical bypass, was proposed to counter overloading in IP networks caused by sudden traffic surges. Approaches proposed to date use single path routing to setup optical bypass. However, the discrete bandwidth granularities of optical circuits may lead to the so-called bandwidth mismatch issue where the capacity of an optical circuit can either be far greater or smaller than the bandwidth required for IP offloading. This eventually increases the cost of IP offloading and leads to inefficient capacity utilization of optical bypasses. In this paper, we propose to employ optical parallel transmission to counter the bandwidth mismatch in IP offloading with consideration of differential delay caused by path diversity. We formulate the problem using Integer Linear Programming (ILP) and analyze the effectiveness of optical parallel transmission to counter bandwidth mismatch in IP offloading. We model the problem under conditions where a) the complete IP traffic matrix is known or b) only typical IP traffic measurements are available. The numerical results show that the use of optical parallel transmission in IP offloading can better match bandwidth requirements of IP offloading, thereby improving resource utilization and reducing the cost of optical bypasses comparing with single path routing.