Impairment-aware lightpath provisioning using inverse multiplexing in mixed-line-rate networks

Abstract

In Mixed-Line-Rate (MLR) networks, different line rates on different wavelengths can coexist on the same fiber. MLR brings flexibility to handle diverse demands by allowing each lightpath to be established end-to-end with different line rates, if necessary. High line rates require advanced modulation techniques, such as DQPSK and DP-QPSK. On the other hand, signals being propagated over transparent paths are exposed to detrimental effects of physical-layer impairments (PLIs). Advanced modulation techniques are highly susceptible to PLI, especially to the cross-phase modulation (XPM) induced by intensity-modulated channels. Inverse multiplexing (IM), in MLR networks, is a technique which exploits the advantage of transmitting the signals with low line rates where the high line rate is not possible due to PLIs. In this study, we propose new algorithms employing IM to account for the impairment-aware dynamic lightpath establishment problem in MLR networks. Experimental results show that our approaches improve the performance in terms of blocking ratio with a cost of additional network resource usage.