The invention provides an intelligent spectrum
allocation method and
system for a self-adaptive
signal-to-
noise ratio of a C + L optical network, and relates to the technical field of
optical fiber communication, and the method comprises the steps: initializing a C + L
wave band elastic optical network, and determining nodes, links, spectrum slots and time slot resources; receiving a service request, and defining a source node, a destination node, time slot requirements and capacities; calculating a
link weight according to a transmission distance and spectrum occupation, and selecting an optimal path; determining a modulation format according to the
path distance, and calculating a required spectrum gap; high-order modulation is allocated to a C
wave band, and low-order modulation is allocated to an L
wave band; ensuring that spectrum slots are continuous and links are consistent, otherwise, the request fails; and selecting the spectrum block distribution with the highest OSNR, comparing the OSNR with a threshold value, and determining whether the request is successful or not. According to the invention, the
transmission quality of the service request is improved, and
resource allocation can be carried out more comprehensively and accurately.