Flexible optical networks (FONs) are being adopted to accommodate the increasingly heterogeneous traffic in today's Internet. However, in presence of high traffic load, not all offered traffic can be satisfied at all time. As carried traffic load brings revenues to operators, traffic blocking due to limited spectrum resource leads to revenue losses. In this study, given a set of traffic requests to be provisioned, we consider the problem of maximizing operator's revenue, subject to limited spectrum resource and physical layer impairments (PLIs), namely amplified spontaneous emission noise (ASE), self-channel interference (SCI), cross-channel interference (XCI), and node crosstalk. In FONs, adaptive modulation, multiple FEC, and the tuning of power spectrum density (PSD) can be effectively employed to mitigate the impact of PLIs. Hence, in our study, we propose a universal bandwidth-related impairment evaluation model based on channel bandwidth, which allows a performance analysis for different PSD, FEC and modulations. Leveraging this PLI model and a piecewise linear fitting function, we succeed to formulate the revenue maximization problem as a mixed integer linear program. Then, to solve the problem on larger network instances, a fast two-phase heuristic algorithm is also proposed, which is shown to be near-optimal for revenue maximization. Through simulations, we demonstrate that using adaptive modulation enables to significantly increase revenues in the scenario of high signal-to-noise ratio (SNR), where the revenue can even be doubled for high traffic load, while using multiple FECs is more profitable for scenarios with low SNR.
翻译:采用灵活光学网络(FONs)来适应今天互联网上日益多样化的流量。 但是,在交通负荷高的情况下,并非所有提供的交通都能够随时满足。随着交通负荷给运营商带来收入,由于频谱资源有限,交通阻塞导致收入损失。在这项研究中,鉴于一系列交通请求有待提供,我们考虑最大限度地增加运营商收入的问题,但需视频谱资源和物理层缺陷(PLI)有限,即自发性噪音增加,自来通道干扰(SCI),跨通道干扰(XCI),以及无交叉跟踪。在FONs,适应性调节、多重FEC以及调频谱密度(PSD)的调整可以有效地用于减轻PLIs的影响。因此,我们在研究中提出了基于频道带宽的宽度的普遍带宽值评估模型,从而可以对不同的私营部门司、FEC和调制系统进行绩效分析。 利用这种低频流干扰模型和直线性调整功能,我们成功地将收入接近于收入最大化的收益最大化,同时使用混合的线性轨道模型来大幅提高收入。