Cyclic-linked flexibility: An architectural approach for reconfigurable optical WDM-TDM access networks
Cyclic-linked flexibility: An architectural approach for reconfigurable optical WDM-TDM access networks
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DOI：
10.1364/jocn.5.000574
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发表时间：
2013-06
期刊：
影响因子：
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通讯作者：
N. Tran;C. Okonkwo;E. Tangdiongga;Hyun-Do Jung;A. Koonen
中科院分区：
文献类型：
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作者：
N. Tran;C. Okonkwo;E. Tangdiongga;Hyun-Do Jung;A. Koonen
下一代光接入网络不仅应该增加容量，而且还应该能够在运行中重新分配容量，以便管理流量模式的更大变化。波长可重配置性是一种能够实现这种网络带宽重新分配能力的工具，因为它允许在WDM-TDM光接入网络中动态共享波长和时隙。然而，可重构性通常需要在用户侧的可调谐激光器和可调谐滤波器，从而导致成本高昂的光网络单元（ONU）。在本文中，我们提出了一个新的概念，称为循环链接灵活性，以解决成本过高的问题。通过使用循环链接的灵活性，ONU只需要在两个预先规划的波长的子集内进行切换，但是波长的循环链接结构允许通过重新布置过程将空闲带宽转移到任何波长。一个基本的重排算法的发展表明，循环链接的灵活性执行接近一个完全灵活的网络的阻塞概率，数据包延迟，和数据包丢失。此外，我们表明，重新安排过程中有最小的影响在服务中的ONU。为了实现循环链接的灵活性，提出了一个可行的成本和波长无关的ONU设计的物理实现。
Next-generation optical access networks should not only increase capacity but also be able to redistribute capacity on the fly in order to manage larger variations in traffic patterns. Wavelength reconfigurability is an instrument that can enable such capability of network-wide bandwidth redistribution since it allows dynamic sharing of both wavelengths and timeslots in WDM-TDM optical access networks. However, reconfigurability typically requires tunable lasers and tunable filters at the user side, resulting in cost-prohibitive optical network units (ONUs). In this paper, we propose a novel concept, named cyclic-linked flexibility, to address the cost-prohibitive problem. By using cyclic-linked flexibility, the ONU needs to switch only within a subset of two preplanned wavelengths, but the cyclic-linked structure of wavelengths allows free bandwidth to be shifted to any wavelength by a rearrangement process. A basic rearrangement algorithm is developed to demonstrate that cyclic-linked flexibility performs close to a fully flexible network in terms of blocking probability, packet delay, and packet loss. Furthermore, we show that the rearrangement process has minimum impact on in-service ONUs. To realize cyclic-linked flexibility, a physical implementation is proposed with a feasible cost and wavelength-agnostic ONU design.