The JPL Phase B interferometer testbed

Future NASA missions with large optical systems will require alignment stability at the nanometer level. However, design studies indicate that vibration resulting from on-board disturbances can cause jitter at levels three to four orders of magnitude greater than this. Feasibility studies have shown that a combination of three distinct control layers will be required for these missions, including disturbance isolation, active and passive structural vibration suppression, and active optical pathlength compensation. The CSI technology challenge is to develop these design and control approaches that can reduce vibrations in the optical train by a factor of 1000 to 10,000. The focus of the paper is on describing the Phase B Testbed structure and facility, as the experimental results are included in other papers presented at this same conference

Spacelab system analysis: A study of the Marshall Avionics System Testbed (MAST)

An analysis of the Marshall Avionics Systems Testbed (MAST) communications requirements is presented. The average offered load for typical nodes is estimated. Suitable local area networks are determined

Field-Trial of a high-budget, filterless, lambda-to-the-user, UDWDM-PON enabled by an innovative class of low-cost coherent transceivers

©2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We experimentally demonstrate an innovative ultradense wavelength division multiplexing (UDWDM) passive optical networks (PON) that implements the full ¿-to-the-user concept in a filterless distribution network. Key element of the proposed system is a novel class of coherent transceivers, purposely developed with a nonconventional technical approach. Indeed, they are designed and realized to avoid D/A-A/D converter stages and digital signal processing in favor of simple analog processing so that they match system, cost, and power consumption requirements of the access networks without sacrificing the overall performance. These coherent transceivers target different use case scenarios (residential, business, fixed, wireless) still keeping perfect compatibility and co-existence with legacy infrastructures installed to support gray, time division multiplexed PON systems. Moreover, the availability of coherent transceivers of different cost/performance ratios allows for deployments of different quality service grades. In this paper, we report the successful field trial of the proposed systems in a testbed where 14 UDWDM channels (and one legacy E-PON system) are transmitted simultaneously in a dark-fiber network deployed in the city of Pisa (Italy), delivering real-time and/or test traffic. The trial demonstrated filterless operations (each remote node selects individually its own UDWDM channel on a fine 6.25-GHz grid), real-time GbE transmissions (by using either fully analog or light digital signal processing), multirate transmission (1.25 and 10 Gb/s), high optical distribution network loss (18-40 dB) as well as a bidirectional channel monitoring system.Peer ReviewedPostprint (author's final draft

Multicast service for ultraflow access networks

Optical Flow Switching (OFS) is envisaged as an efficient solution for ultra-broadband end-to-end Internet data transfers. In this paper, we investigate the possibility of providing multicast services over a recently proposed UltraFlow access network that offers two types of access service to its end-users at the same time: IP over GPON and OFS. Our focus is set on the viability of multicast in this dual-mode access concept. This paper studies several application scenarios for multicast UltraFlow access and makes a preliminary assessment of practical feasibility of this service.The authors would like to acknowledge the support of the Chair of Excellence of Bank of Santander – UC3M, the National Science Foundation, NSERC and the Spanish projects CRAMnet (grant no. TEC2012-38362-C03-01), and MEDIANET

An FPGA implementation of a sleep enabled PON system

Owing to the growing demand for bandwidth-hungry video-on-demand applications, Passive Optical Network (PON) has been widely considered as one of the most promising solutions for broadband access. Environmental concerns motivated network designers to lower energy consumption of optical access networks. A well-known approach to reduce energy consumption is to allow network elements to switch to the sleep mode. In this framework, an improved Optical network Unit (ONU) architecture in TDM-PON is proposed to reduce the handover time of status switching. Energy-saving performances of current and improved architectures are compared in different scenarios. The simulation results show that by applying a proper sleep mode mechanism, the improved architecture can effectively reduce the ONU energy consumption. We further implement the cycle sleep scheme on a multi-ONU testbed based on the improved ONU architecture. The experimental results have substantiated the viability of the improved ONU architecture

Multilevel bandwidth measurements and capacity exploitation in gigabit passive optical networks

The authors report an experimental investigation on the measurement of the available bandwidth for the users in gigabit passive optical networks (GPON) and the limitations caused by the Internet protocols, and transfer control protocol (TCP) in particular. We point out that the huge capacity offered by the GPON highlights the enormous differences that can be showed among the available and actually exploitable bandwidth. In fact, while the physical layer capacity can reach value of 100 Mb/s and more, the bandwidth at disposal of the user (i.e. either throughput at transport layer or goodput at application layer) can be much lower when applications and services based on TCP protocol are considered. In the context of service level agreements (SLA) verification, we show how to simultaneously measure throughput and line capacity by offering a method to verify multilayer SLA. We also show how it is possible to better exploit the physical layer capacity by adopting multiple TCP connections avoiding the bottleneck of a single connection