We have been using the cross layer design tools that have been extremely successful in the wireless domain to develop algorithms for efficient operation of optical networks. These algorithms will leverage the recent advances in optical real time measurements and dynamic optical devices (such devices enable, for example, dynamic power, bandwidth, and modulation control) to adapt the behavior of the optical networks based on real time measurements, traffic patterns, and service level agreements. Dynamic operation will lead to significantly improved performance in terms of throughput, delay, and energy consumption. Moreover, enabling dynamic operation at the optical domain will provide an important step towards Software Defined Networking (SDN) for the optical (physical) layer.
Our work in this area is done in collaboration with the Columbia Lightwave Research Lab and takes places mostly within the NSF Center for Integrated Access Networks (CIAN) Engineering Research Center (ERC). The center develops the CIAN Box which is an information aggregation node that uses real-time optical performance measurements and energy consumption monitoring, to enable application and impairment-aware switching, regeneration, and adaptive coding. Due to the capability of the CIAN Box to react to measurements of the optical link and to adapt to traffic characteristics, there is a need for network management algorithms that span the various layers of the protocol stack. As a first step, we developed and evaluated a network-wide optimization algorithm that leverages measurements to dynamically control the wavelengths’ power levels. Hence, it allows adding and dropping wavelengths quickly while mitigating the impacts of impairments caused by these actions, thereby facilitating efficient operation of higher layer protocols.
In addition, we have been developing cross-layered algorithms for converged wireless-optical networks. For example, the video below demonstrates a preliminary wireless-optical testbed that connects a WIMAX base station (deployed in Columbia as part of the GENI project by the Internet Real Time Lab) and an optical network (within the Columbia Lightwave Research Lab).
For more details on our ongoing work in this area, see the Fall 2012 issue of the Columbia Engineering Magazine.