PLI-aware cost management for green backbone all-optical WDM networks via dynamic topology optimization

To cope with the energy inefficiency as well as the temporal uncertainty of real-world traffic in all-optical backbone networks, we explore the performance gains obtained from adaptively putting network elements into sleep mode, taking into account physical layer impairments (PLIs). Despite recent progress on link sleep mechanisms, the beneficial impacts of periodically activating and deactivating line amplifiers are seriously restricted by extra incurred operational expenditures due to accelerated aging of network equipment, which is a direct consequence of temperature fluctuations. In this paper, we revisit the problem of green PLI-constrained lightpath establishment, paying close attention to minimizing the number of on/off transitions. Toward this end, we formulate green lightpath establishment as a nonlinear multi-objective optimization problem, which addresses not only the energy efficiency, but also the grade of service and quality of service, using accurate models of a wide variety of linear/nonlinear PLIs. To tackle the developed problem under realistic scenarios, we propose the so-called green adaptive time-aware algorithm, which consists of lightpath establishment as well as wake-up/sleep procedures. The presented analysis followed by verifying simulations confirms that the proposed algorithm stands as a practical solution to the cost-efficient green impairment-constrained lightpath establishment problem under temporal uncertainly of incoming traffic.