Investigation of cost, power, and spectral efficiency in fixed- and flexi-grid networks

Abstract

With the steady growth of traffic volume in core networks, it is predicted that future optical network communication will be constrained mainly by cost and power consumption. Thus, for Internet sustainability, it will be necessary to ensure cost and power efficiency in optical networks. The aims of this study are (i) to identify the main sources of cost and power consumption in fixed-grid (SLR and MLR) and flexi-grid (OFDM) optical networks, and (ii) to compare techniques for improving cost and power efficiency in SLR/MLR-and OFDM-based networks. To this end, we conducted a comparative analysis of cost and power efficiency for the OFDM-and MLR/SLR-based networks, and considering realistic networks, evaluated the cost and power consumed by different components in the optical layer. Our results show that (i) OFDM-based networks outperform those based on MLR/SLR in terms of both cost and power-efficiency, (ii) the extra equipment cost incurred due to under-utilization of spectrum is reduced by switching to a flexi-grid network, (iii) lower power consumption per bit is obtained when the networking solution ensures a finer bit-rate granularity, and (iv) there exists a power and spectrum minimization trade-off that is network characteristic dependent.

Multiple-period planning of Internet Protocol-over-Elastic Optical Networks

“…In regard to BVTs, we assume the availability of two BVT types, namely one with 400 Gbps maximum rate, and the other with 1 Tbps maximum rate which is assumed to be available only after the year 2020. Following studies in Iyer and Singh (2017b) and IDEALIST Project (2014), in Table 2, we present various other parameters in regard to BVTs. In regard to IP routers, cost model which is adopted accounts for utilized number(s) of (i) linecard(s), (ii) linecard chassis and (iii) linecard chassis fitted into a fibrecard chassis, with a cost of 6.04 U.C., 9.3 U.C.…”

“…In regard to IP routers, cost model which is adopted accounts for utilized number(s) of (i) linecard(s), (ii) linecard chassis and (iii) linecard chassis fitted into a fibrecard chassis, with a cost of 6.04 U.C., 9.3 U.C. for (i) and (ii), respectively (Iyer & Singh, 2017b). Furthermore, for hosting linecards, core routers have a slot capability that ranges between 16 and 1152 slots; and a single linecard type of cost 2.58 U.C.…”

“…In the current study, we adopt the EON architecture from our previous study (Iyer & Singh, 2017b) in which the EON is assumed to consist of (i) fibre links comprising single-mode fibre spans, and Erbium Doped Fiber Amplifiers (EDFAs) and (ii) optical switches which operate as Reconfigurable Optical Add Drop Multiplexers (ROADMs) that employ flexigrid technology, and also support lightpaths of individual or multiple contiguous 12.5 GHz slots of spectrum. The IP/MPLS routers comprise optical domain edges, and it may occur that no, single or multiple such routers are connected to an optical switch.…”

“…Following (IDEALIST Project, 2014), the IP/MPLS router model assumed in the current study is that of a modular type which is constructed by using one or many chassis, and further, within every slot in the router, a linecard is also installed, whose speed corresponds to that provided by the chassis. Within the optical layer, it is assumed that the tuples of transmission detail the capability of transmission of the transponders (Iyer & Singh, 2017b). Every tuple T (i) is used to specify a certain transponder configuration in terms of the bit-rate and the spectrum and (ii) has a relation to a certain TR which accounts for the optical physical layer model.…”

On routing, modulation format, space and spectrum allocation with protection in space division multiplexing-based elastic optical networks

“…In addition to considering protection, RMFSSA-w-P also utilizes different MFs which are chosen in accordance with the distance between the source and the destination since, with higher numbers of bits in every symbol, attenuation of the signal is more which results in incorrect signal decoding at the receiver (Iyer, 2017a). Also, the MFs with higher numbers of bits in every symbol have higher power consumption than those MFs which have lesser number of bits in every symbol; however, such MFs are more efficient owing to their power consumed in every bit ratio being higher (Iyer & Singh, 2017b). Following the studies conducted by (Iyer, 2018;Khodashenas et al, 2017;Perelló, Gené, Pagès, Lazaro, & Spadaro, 2016), the considered MFs in the current study along with their various parameters are detailed in Table 2.…”