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Future optical metro access networks will connect heterogeneous access technologies like beyond 5G radio access networks and edge computing interconnections. These access networks and their diversified use cases will impose significant challenges on network capacity, wavelength resource and network synchronization. In this paper, we present and investigate a novel time slotted optical metro access network controlled by a multifunctional supervisory channel for precise time distribution, nodes synchronization, and fast wavelength reusing to improve the overall network performance for low and deterministic latency applications. The supervisory channel carries timestamps of different nodes in different time slots, and the labels with the data channels destinations in every time slot. By analyzing the supervisory channel at each node, the timestamps and add/drop information can be precisely and fast exchanged. A network testbed has been implemented for assessing the proposed network operation and precise time synchronization. The results show successful time slotted network operation, 82% of bandwidth usage and 2.5 s latency have been achieved. Below 12 ns time accuracy has been measured for a metro ring and 5G front haul network with a single time reference. To assess the scalability and wavelength saving of the proposed network in a larger network, a simulation model has been developed in OMNeT++ based on the experimental parameters. Numerical results show more than 16 % wavelengths can be saved by our technology compared with Cloud Burst Optical-Slot Switching (CBOSS)[1].

To solve the issues of low resource utilization and performance bottleneck in current server-centric data center networks (DCNs), we propose and experimentally demonstrate a disaggregated application-centric optical network (DACON) for data center infrastructures based on hybrid optical switches. DACON achieves flexible provision and dynamic reconfiguration of hardware nodes exploiting the softwared-define networking (SDN) orchestration plane. A four-node SDN-enabled disaggregated prototype is implemented with a field-programmable-gate-array-based controller of hardware nodes and nanosecond optical switches, performing a minimal node-to-node network latency of 378.6 ns and zero packet loss. Based on the unmodified Linux kernel and two different applications (distributed computing and a Memcached database), the application runtime of the disaggregated prototype is investigated and compared with the server-centric architecture. Experimental results show that the disaggregated prototype performs better with Memcached database applications, achieving a 1.46 × faster runtime than the server-centric network at a memory node access ratio of 0.9. Based on the customized control plane orchestrator and dynamic resource reallocation, the node-to-node latency is reduced by 21% when CPU nodes access memory nodes. The scalability of DACON is then numerically assessed based on experimentally measured parameters. Results show that the intra-rack node-to-node latency is less than 404.8 ns with a 6144-node network and memory node access ratio of 0.9. Finally, the cost and power consumption are also studied and compared with current DCN architectures. Results indicate DACON saves 13.4% of the cost of an interconnect network compared with current disaggregated architecture and consumes up to 31.1% less power with respect to server-centric DCN architectures.