Design cost and spectrum efficiency comparison of fixed-grid and flex-grid optical networks with grooming

Abstract

-This paper deals with the design of optical networks aiming to minimize the design cost and the spectrum usage. We present an optimization method that is able to find the optimal solutions of relevant sized instances. We apply the method to realistic case studies. With the obtained solutions, we make a cost and spectrum efficiency comparison analysis between fixed-grid and flex-grid optical networks. The results show that flex-grid gains are significant over the fixed-grid alternatives only after the introduction of 400 Gbps line rates and marginal gains are obtained without this line rate.

A Performance Comparison of Centralized and Distributed Spectrum Management Techniques in Elastic Optical Networks

“…Many studies that deal with signaling aspects have used the basic First Fit and Random Fit spectrum assignment algorithms in their simulations and we borrowed the idea in this paper [29]. Numerous sophisticated routing and spectrum allocation algorithms have been developed that achieve better capacity utilization but require a higher level of processing or complexity including [4,7,10,15,16,26,29,33]. EON planning using statistical path models is demonstrated in [30].…”

“…Realistic case studies [33] have been simulated for a network's busy hour, with a lesser number of connection requests, in a near parallel mode to differentiate between the efficiency of Centralized Network Operation Mode (C-NOM) and (vs.) a Distributed Network Operation Mode (D-NOM). These case studies provide some optimal frequency, bandwidth, and base slot values [33] to achieve a 100% success rate in a centralized network operation during the busy hour of network state, which we utilize in this work. The two types of distributed reservation protocols that were used in simulations are Backward Reservation Protocol (BRP) and Forward Reservation Protocol (FRP).…”

“…In this section, a centralized network operation is compared with respect to distributed network operation in the busy hour operation scenario for connection establishment. A specific set of 8 case studies is used for this comparative study [33] via the simulation tool for the results generated. The simulation tool has been completely developed in C++ and has a Graphical User Interface (GUI) to input specific user defined network parameters.…”

“…The Finland network topology has 12 network nodes and 19 fiber links and the Germany network topology has 17 nodes and 26 fiber links. As in [33], which serves as the source of our 8 case studies for optimal capacity assignment, as well as many other EON studies, each link is assumed to have 160 frequency slots of 25 GHz (2x12.5 GHz), with a total spectrum capacity of 4 THz. As in many EON studies, we have not explicitly considered guard bands in our simulations for simplicity.…”

“…This section covers the BRP signaling in C-NOM and D-NOM. Again, the data that has been used in C-NOM, i.e., , , , , h, and , have been referred from realistic network case studies [33]. The simulation parameters are the same as in Table 1.…”