Delayed spectrum allocation in elastic optical networks with anycast traffic

We investigate the problem of dynamic routing and spectrum assignment for advance reservation anycast requests using a novel algorithm called Delayed Spectrum Allocation (DSA) which delays allocation of resources until immediately before transmission begins. We evaluate the flexible window STSD (demands that specify start-time and duration) to further improve request blocking. Through extensive simulation results, we show that anycast with flexible STSD using DSA approach can significantly reduce blocking probability of anycast and unicast requests compared to traditional Immediate Spectrum Allocation (ISA). The improvement is up to 50 percent in unicast traffic and even higher in anycasting. We also propose balanced routing for anycast algorithms to reduce the blocking. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement