RESUMO
Software Defined Networking represents a mature technology for the control of optical networks, though all open controller implementations present in the literature still lack the adequate level of maturity and completeness to be considered for (pre)-production network deployments. This work aims at experimenting on, assessing and discussing the use of the OneM2M open-source platform in the context of optical networks. Network elements and devices are implemented as IoT devices, and the control application is built on top of an OneM2M-compliant server. The work concretely addresses the scalability and flexibility performances of the proposed solution, accounting for the expected growth of optical networks. The two experiment scenarios show promising results and confirm that the OneM2M platform can be adopted in such a context, paving the way to other researches and studies.
RESUMO
We propose and demonstrate a programmable and self-adaptive VCSEL-based transponder for short-reach applications that is easily extensible up to access and metro scenarios. The transponder presents a monitoring system that feeds the transponder controller in order to maintain the proper transmission performance. The emerging NETCONF protocol including the YANG model controls and manages the transponder. NETCONF messages are reported for two reference scenarios - uncooled and cooled systems - together with performance at varying environment conditions. For the uncooled scenario heating processes on the board are emulated with various dynamics, the effect on the performance of a 25 Gbps WDM channel is checked through optical power monitoring and the control plane reacts so as to optimize the performance by suitably controlling the bias current. For slow temperature variations the system is able to avoid service outage whereas for variations faster than 1.3 °C/s outage occurs and corresponding notifications are opportunely triggered. For the cooled scenario, an optical power loss is emulated with consequent service outage, leading to a reconfiguration of the transponder data rate from 25 to 10 Gbps, so as to recover successful transmission.
RESUMO
This paper proposes an energy-saving passive optical network framework (ESPON) that aims to incorporate optical network unit (ONU) sleep/doze mode into dynamic bandwidth allocation (DBA) algorithms to reduce ONU energy consumption. In the ESPON, the optical line terminal (OLT) schedules both downstream (DS) and upstream (US) transmissions in the same slot in an online and dynamic fashion whereas the ONU enters sleep mode outside the slot. The ONU sleep time is maximized based on both DS and US traffic. Moreover, during the slot, the ONU might enter doze mode when only its transmitter is idle to further improve energy efficiency. The scheduling order of data transmission, control message exchange, sleep period, and doze period defines an energy-efficient scheme under the ESPON. Three schemes are designed and evaluated in an extensive FPGA-based evaluation. Results show that whilst all the schemes significantly save ONU energy for different evaluation scenarios, the scheduling order has great impact on their performance. In addition, the ESPON allows for a scheduling order that saves ONU energy independently of the network reach.