Cost analysis for elastic optical networking: Single channel vs. multi channels

Elastic optical networking (EON) equipped with multiple modulation formats has recently emerged as a promising solution to flexible provisioning in optical networks. To overcome the limit of high-order modulation formats for long distance transmission, traffic can be split and carried by multiple channels, with each modulated at lower rates. However, the flexibility offered by EON and its multi-channel variant comes with a higher cost for extra hardware components (e.g., laser and modulator array). This paper studies the single- and multi- channel EON schemes from a cost effectiveness point of view, with comparison to the conventional 40/100G provisioning scheme based on the ITU-T grid. We first propose and discuss the hardware module implementation of the EON schemes. By decomposing the hardware module into mechanics and electrical, analog/digital conversion, and optics, we propose cost models for each part based on current and historical market data. Two key metrics, hardware cost and traffic-share cost, are calculated and analyzed. We show that the hardware cost based on the proposed model well matches the market trend. Also, the result indicates that the two EON schemes, though are more expensive due to hardware complexity, can effectively reduce the traffic-share cost according to our simulation of a network-wide provisioning scenario. In particular, the multi-channel EON can reduce the traffic-share cost by up to 21.1% from the single-channel EON in the investigated scenarios, achieving the highest cost effectiveness among the three schemes.