查看文章

We consider the problem of serving traffic in a spectrum-flexible optical network, where the spectrum allocated to an end-to-end connection can change so as to adapt to the time-varying required transmission rate. In the proposed framework, each connection is assigned a route and is allocated a reference frequency over that route, using an appropriate Routing and Spectrum Allocation (RSA) algorithm, but the spectrum it utilizes around the reference frequency is allowed to expand and contract to match source rate fluctuations. We propose and analyze three spectrum expansion/contraction (SEC) policies for modifying the spectrum allocated to each connection. The first policy, named the Constant Spectrum Allocation (CSA) policy, allocates a number of spectrum slots for exclusive use by each connection. We also present two policies that enable the dynamic sharing of spectrum slots among connections, named …