In this work, we report the designing and simulative analysis of a novel 400 Gbps coherent detection-orthogonal frequency division multiplexing (CO-OFDM) based inter-satellite optical wireless communication (IsOWC) system incorporating polarization division multiplexing (PDM) for enhancing information carrying capacity of the link. The performance of the proposed system has been discussed for 4-level phase shift keying and quadrature amplitude modulation encoding schemes using signal-to-noise ratio, total received power, and constellation diagram of the received signal as performance metrics. Also, the impact of different parameters such as operating wavelength, transmission power, and receiver pointing error angle on the performance of the proposed system has been investigated. Furthermore, an enhanced detection technique for link reach enhancement has been reported in this work. Finally, the performance of the proposed CO-OFDM based IsOWC system has been compared for with and without using the PDM technique.

Modeling and Performance Analysis of 400 Gbps CO-OFDM Based Inter-satellite Optical Wireless Communication (IsOWC) System Incorporating Polarization Division Multiplexing with Enhanced Detection

Soft-failure localization frameworks typically use if-else rules to localize failures based on the received telemetry data. However, in certain cases, particularly in disaggregated networks, some devices may not implement telemetry, or their telemetry may not be readily available. Alternatively, machine-learning-based (ML-based) frameworks can automatically learn complex relationships between telemetry and the fault location, incorporating information from the telemetry data collected network-wide. This paper evaluates an ML-based soft-failure localization framework in scenarios of partial telemetry. The framework is based on an artificial neural network (ANN) trained by optical signal and noise power models that simulate the network telemetry upon all possible failure scenarios. The ANN can be trained in less than 2 min, allowing it to be retrained according to the available partial telemetry data. The ML-based framework exhibits excellent performance in scenarios of partial telemetry, practically interpolating the missing data. We show that in the rare cases of incorrect failure localization, the actual failure is in the localized device’s vicinity. We also show that ANN training is accelerated by principal component analysis and can be carried out using cloud-based services. Finally, the evaluated ML-based framework is emulated in a software-defined-networking-based setup using the gNMI protocol for streaming telemetry.

Machine-learning-based soft-failure localization with partial software-defined networking telemetry

To meet the 5G requirements for higher bandwidth, the focus has been shifted to millimeter waves paving the way to radio over fiber (RoF) in order to minimize radio losses Dual wavelength transmission within RoF for electromagnetic immunity interference (EMI) can be utilized within local area network and long-haul transmission Health care services will also be able to utilize the technology to transmit health-related data from thousands of patients to the specific destination by connecting to the long-haul fiber optic cable connection To make dual-wavelength transmission stable and reliable, the formation of the two-wavelength light source is proposed in this paper by means of the double coupled micro-ring resonators The proposed RoF system will be able to transmit EMI signals of patients over 300 km of optical fiber link and 3 m wireless link without the need for any intermediate signal amplifying device All the patient’s data will be available to any doctor in any hospital securely by integrating with currently available wireless and the internet of things systems

Dual-wavelength transmission system using double micro-resonator system for EMI healthcare applications

On solving the capacitated routing and spectrum allocation problem for flexgrid optical networks

Elastic optical networks (EONs) are a promising technology for the next-generation optical network, and advanced reservation (AR) applications have been growing expeditiously over the past few years. Thus, the routing and spectrum allocation problem for AR requests has become a significant concern. This paper proposes an approach named outright fit advanced resource reservation to improve the spectral resource allocation efficiency for AR connection requests. Our proposed approach works in two stages: The proposed resource reservation strategy first uses an outright fit resource allocation strategy to reserve the spectral resource for a connection request within the absolute best service window and leaves adequate spectral resources for subsequent requests. If a connection request cannot get resources in the first stage, the proposed optimal rescheduling technique then is applied to serve the request. Our proposed optimal rescheduling technique uses spectrum shifting and reallocation without altering the routing paths, and its optimal characteristic decreases the number of rescheduling operations, thereby decreasing the rescheduling computational complexity and cost, which improves the network’s quality of service. Moreover, this rescheduling approach increases the opportunities for successful rescheduling of the requests without inducing many spectrum fragments, significantly reducing the blocking probability. The simulation results illustrate that the proposed approach can considerably enhance the blocking performance and obtains high spectrum utilization.

Outright fit resource allocation approach for advance reservation requests in elastic optical networks

Proposal and performance analysis on the PDM microwave photonic link for the mm-wave signal with hybrid QAM-MPPM-RZ modulation

Considering the flexibility characteristic of advanced reservation (AR) requests, the problem of static routing, modulation, spectrum, and time assignment (RMSTA) of AR requests in elastic optical networks is studied in this paper, in order to deploy the spectrum resource economically and enable more requests to be served. The multi-objective integer linear program (ILP) model, which can minimize the maximum utilized frequency and time slot indices as well as find a trade-off between them, is used to formulate the RMSTA problem. Then the proportion optimal RMSTA (PO-RMSTA) heuristic algorithm with three sorting strategies is proposed to get the sub-optimal solutions. The PO-RMSTA algorithm and sorting strategies, ascending order of elastic time (AET), descending order of data volume (DDV), and ascending order of alternative schemes (AAS), are simulated in our work and proved to obtain the approximate optimal solutions. The sorting policy AET achieved the best performance when minimizing the maximum utilized frequency slot index, whereas the sorting policy DDV worked best when minimizing the maximum utilized time slot index. As for the compromise between two indices, both AET and AAS provided satisfying results.

Static resource allocation of advanced reservation requests in elastic optical networks.

Embodiments of the invention provide a network resource reservation method and device The method includes the following steps: converging and assembling a source data packet according to QOS of the source data packet to generate a burst data packet, and performing fragmentation processing on the generated burst data packet to generate a fragmentation packet; generating a burst control packet by utilizing the fragmentation packet and the burst data packet; transmitting the burst control packet to a core node, and determining a shortest path and an alternate path for transmitting the burst datapacket; in view of incapable of transmitting the burst data packet by a channel resource of the determined shortest path, based on the weight of the generated fragmentation packet and the size of thefragmentation packet, reserving the channel resource for a first fragmentation packet on the shortest path according to the size of the channel resource of the shortest path; and reserving the channel resource for a second fragmentation packet on the alternate path According to the scheme applied to embodiments of the method and the device, additional network delay can be avoided on the basis ofensuring the resource utilization rate and reducing occurrence of a large number of resource request conflicts at the core node

Network resource reservation method and device

The embodiment of the invention provides a dynamic service grooming processing method and device in an elastic optical network, and the method comprises the steps: building a virtual network topological structure, and initializing a network busy state value; receiving a service request and taking the service request as a sub-service request, converging the sub-service requests which have the samesource and destination nodes and meet conditions into a current service request, and carrying out weight and bandwidth marking on the sub-service request; updating a network busy state value based onthe network state of the current virtual network topology structure, and determining whether the current service request belongs to a high-priority service request or not; if so, determining a virtuallink for the current service request by using a first service grooming strategy; if not, determining a virtual link for the current service request by using a second service grooming strategy; and performing routing and spectrum allocation on the determined virtual link in a physical network topology. According to the invention, the service requests with different requirements can be intelligently groomed based on the network state, and the service dredging performance is improved.

Yi Zhao

Papers

Proposal and performance analysis on the PDM microwave photonic link for the mm-wave signal with hybrid QAM-MPPM-RZ modulation

Static resource allocation of advanced reservation requests in elastic optical networks.

Network resource reservation method and device

Dynamic service grooming processing method and device in elastic optical network