Effect of Channel Spacing on the Design of Mixed Line Rate Optical Wavelength Division Multiplexed Networks (original) (raw)

2017, Journal of Optical Communications

The ever increasing heterogeneity and growing traffic volume has resulted in significant innovations and paradigm shifts within the telecom backbone networks. In order to cost-effectively respond to the diverse variety of traffic requirements having heterogeneous service demands, wavelength division multiplexed (WDM) optical networks have adopted the mixed line rate (MLR) strategy. In MLR networks, many wavelength channels with various line rates can co-exist within the same fiber which, however, raises many important design issues; one of them being the choice of the channel spacing. The quality of signal is affected by the channel spacing in terms of the bit-error rate (BER), which in turn affects the maximum optical reach of the lightpaths that depends on the line rates. In regard to the aforementioned, different methods can be adopted in order to set the width of the channel spacing, viz., (a) choice of a 50 GHz uniform fixed channel spacing specified by the ITU-T grid, (b) expl...

Impact of channel spacing on the design of a mixed-line-rate optical network

2009

Due to the increasing heterogeneity and the growing volume of traffic, telecom backbone networks are going through new innovations and paradigm shift. The wavelength-division multiplexed (WDM) optical networks may cost-effectively support the growing heterogeneity of traffic demands by having mixed line rates (MLR) over different wavelength channels. The coexistence of wavelength channels with different line rates in the same fiber brings up the important issue of the choice of the channel spacing that one can have in these MLR networks. The channel spacing affects the signal quality in terms of bit-error rate (BER), and hence affects the maximum reach of the lightpaths, which is a function of line rates. Various approaches to set an opportunistic width of the channel spacing can be considered: i) on a practical side, one may choose uniform fixed channel spacing specified by the ITU-T grid (typically 50 GHz); ii) alternatively, to optimize the usage of the fiber spectrum, one can explore different channel spacing for different line rates, also referred to as the "one-size-does-not-fit-all" approach; iii) else an optimal value of channel spacing that leads to minimum cost can be sought. In this work, we investigate the third case by evaluating the cost of a MLR network for different channel spacings. Our results show that, even under the assumption of uniform channel spacing for a MLR network, it is possible to identify optimal values of channel spacing for a minimum-cost MLR network design.

Adapting the transmission reach in mixed line rates WDM transport networks

We consider the problem of planning a mixed line rates (MLR) wavelength division multiplexing (WDM) transport optical network. In such networks, different modulation formats are usually employed to support the transmission at different line rates. Previously proposed planning algorithms, have used a transmission reach limit for each modulation format/line rate, mainly driven by single line rate systems. However, transmission experiments in MLR networks have shown that physical layer interference phenomena are more significant between transmissions that utilize different modulation formats. Thus, the transmission reach of a connection with a specific modulation format/line rate depends also on the other connections that co-propagate with it in the network. To plan a MLR WDM network, we present routing and wavelength assignment (RWA) algorithms that take into account the adaptation of the transmission reach of each connection according to the use of the modulation formats/line rates i...

Loading...

Loading Preview

Sorry, preview is currently unavailable. You can download the paper by clicking the button above.