Connection optimization and control in agile networks

摘要

An agile network is provided with a layered control system for maintaining a network-wide target performance parameter (e.g. power) along all end-to-end connections. A connection is controlled at the physical layer using optical control loops that have a concatenated response based on a set of loop time constants. The network is separated into gain based span loops and power based switch loops; each link has a gain profile, and requires a per-wavelength power target as the output power target for the switch loop at the start of the link. Use of achievable gain for the span loops allow to optimize the performance of the link. Use of individual achievable power targets allows each switch loop to autonomously ramp on and off channels without causing interference with existing and other ramping channels. A loop control uses a model-based rules block, to distribute control signals to an optical section encompassing a plurality of optical components. Results from a set of tests performed during link commissioning are used as parameters for the expert system. After examining the current status of the entire optical section and collecting a set of measurements, the rules block determines the best way to achieve the target, whilst maximizing performance. Use of an embedded expert system enables to perform accurate real time performance estimation. Use of a model for all optical sections allows a level of abstraction at the loop boundaries, such that changes can be made independently. A device template is used for all optical devices in the network. The template defines the control and monitoring points for the respective device and specifies the type, range, and points to the device constants. With each iteration, the model and the current optical path measurements are used to adjust the optical path settings and update the model.