Elimination of all-optical cycles in wavelength-routed optical networks
Elimination of all-optical cycles in wavelength-routed optical networks
复制标题
消除波长路由光网络中的全光循环
DOI：
10.1109/50.511622
复制
发表时间：
1996
影响因子：
4.7
通讯作者：
Krishna Bala
中科院分区：
文献类型：
--
作者：
Jason Iness;B. Ramamurthy;B. Mukherjee;Krishna Bala
波长交叉连接的交换机通过光纤连接在一起形成任意网状结构，可以构建透明（广域）波长路由光网络。这个网络是通过连接到一些交叉连接的电子站来访问的。这些波长交叉连接开关具有可以将自己配置为未指定状态的特性。交换机的每个输入端口总是连接到交换机的某个输出端口，无论这种连接是否用于信息传输。由于这些未指定状态的存在，存在在网络中建立非预期的全光周期的可能性（即，其中没有终端电子的环路）。如果这样一个周期包含放大器[例如，掺铒光纤放大器（EDFA’s）]，则存在净环路增益大于净环路损耗的可能性。来自放大器的放大的自发发射（ASE）噪声可以在这样的反馈环路中积累，使放大器饱和并导致环路中ASE噪声的振荡。如上所述的全光周期（以后称为“白”周期）必须从光网络中消除，以使网络执行任何有用的操作。此外，对于波长交叉连接导致信号串扰的实际情况，存在具有振荡串扰信号的闭合周期的可能性。我们研究了根据请求建立新的透明光连接的算法，同时避免了在网络中产生这种循环。这些算法试图为连接找到一条路由，然后（以后处理的方式）配置交换机，使可能产生的白循环自动消除。此外，我们的呼叫建立算法可以避免串扰周期的可能性。
A transparent (wide-area) wavelength-routed optical network may be constructed by using wavelength cross-connect switches connected together by fiber to form an arbitrary mesh structure. The network is accessed through electronic stations that are attached to some of these cross-connects. These wavelength cross-connect switches have the property that they may configure themselves into unspecified states. Each input port of a switch is always connected to some output port of the switch whether or not such a connection Is required for the purpose of information transfer. Due to the presence of these unspecified states, there exists the possibility of setting up unintended all-optical cycles in the network (viz., a loop with no terminating electronics in it). If such a cycle contains amplifiers [e.g., erbium-doped fiber amplifiers (EDFA's)], there exists the possibility that the net loop gain is greater than the net loop loss. The amplified spontaneous emission (ASE) noise from amplifiers can build up in such a feedback loop to saturate the amplifiers and result in oscillations of the ASE noise in the loop. Such all-optical cycles as defined above (and hereafter referred to as "white" cycles) must be eliminated from an optical network in order for the network to perform any useful operation. Furthermore, for the realistic case in which the wavelength cross-connects result in signal crosstalk, there is a possibility of having closed cycles with oscillating crosstalk signals. We examine algorithms that set up new transparent optical connections upon request while avoiding the creation of such cycles in the network. These algorithms attempt to find a route for a connection and then (in a post-processing fashion) configure switches such that white cycles that might get created would automatically get eliminated. In addition, our call-set-up algorithms can avoid the possibility of crosstalk cycles.