Cost sensitivity evaluation of fixed/flexible rate line-cards and transceivers under incremental traffic

The transmission of optical channels above 100 Gb/s poses scalability issues for transport networks, as the optical carrier capacity does not keep up with the client signal demand, forcing the adoption of multiplexed 100 and 200 Gb/s signals on the line side. This scenario motivates the design of line-cards that support multiple transceivers capable of operating individually to carry lower data-rate client signals or jointly to form superchannels. Moreover, these line-cards and transceivers can either support a single fixed-rate or multiple bitrates. The latter option is potentially more suitable to accommodate changing traffic demands. This paper compares the expected network cost when fixed and flexible-rate line-cards and transceivers are deployed optimally over multiple planning cycles, taking into account the parameters that are most likely to affect the cost efficiency of one solution over the other and analysing the influence of these parameters on the overall cost.