Optical Network Terminals Research Articles

O-band QKD link over a multiple ONT loaded carrier-grade GPON for FTTH applications.

We have successfully demonstrated the integration of a commercial O-band Quantum Key Distribution (QKD) system over a testbed that replicates a carrier-grade Fiber-to-the-Home (FTTH) optical access network consisting of components and systems installed in real-life FTTH operational deployments. The experiment demonstrated a QKD transmission over a 1:16 user Gigabit Optical Passive Network (GPON) configuration featuring a total of 9 Optical Network Terminals (ONTs) at the premises of the Telecom Operator COSMOTE that followed the operator's standard FTTH divided in two splitting stages. The architecture we implemented was a downstream access network with the quantum transmitter located at the operator's Central Office (CO) and the quantum receiver located on the end user's side.

Intelligent optical transceiver technology based on federated learning traffic prediction

With the development of optical network, modern optical network needs better performance. Because the traditional optical transceiver technology has a delay according to the flow switching transmission configuration, the delay optical network service still adopts the original configuration transmission, so a certain degree of frequency spectrum resources waste and high blocking rate will be caused. The above situation can be improved if the transmission configuration can be deployed in advance based on the predicted traffic. Federated learning is a scheme of distributed training model, which can train the traffic prediction model in distributed way under the premise of ensuring the privacy of client data, which is very suitable for the traffic prediction of optical network terminals. This paper proposes an intelligent optical transceiver technology based on federal learning traffic prediction, applies the federal learning on the traffic prediction of optical communication network terminal, distributed training traffic prediction model, and deploy the optical transceiver early transmission configuration such as modulation format and baud rate parameters, thus to weaken the delay of optical transceiver technology, reduce the network blocking rate and improve the transmission performance of optical network.

Feasibility analysis of 2-dimensional permutation vector optical code division multiple access passive optical network

This paper analyzes the feasibility of a 2-dimensional (2D) permutation vector (PV) optical code division multiple access (OCDMA) passive optical network (PON) in terms of transmission capacity, network reliability, power budget, and the number of subscribers. The proposed PON is built with a novel 2D PV-OCDMA code having ideal auto- and cross-correlation properties. Furthermore, a ring-based topology at the feeder level and a tree-based topology at the distribution level are utilized to support ubiquitous computing. The proposed architecture also employs multiple remote nodes at the feeder level to facilitate adequate power budget and cardinality for high-capacity applications. Simulation results indicate that the proposed PON elevates system transmission capacity by eliminating phase-induced intensity noise and multiple access interference. Furthermore, reliability analysis using mathematical formalism demonstrates that the proposed architecture can provide a connection availability of ≈0.099993 (5 nines), which is significantly higher than the conventional tree-based topology. Power budget analysis also determines that the proposed PON can support well above 320 subscribers at adequate receiver sensitivity and optical network terminals (ONTs) per remote node.

Laser Sharing Uplink Polarization Division Multiplexing FBMC Passive Optical Network

In this paper, we proposed and experimentally demonstrated a laser sharing filter bank multicarrier passive optical network (FBMC-PON) uplink architecture, to provide high spectrum efficiency frequency division multiple access (FDMA) to the optical network terminals (ONTs) with aggregated uplink data rate of up to 100 Gb/s/λ for each optical network unit (ONU), in a fiber to the frontage (FTTF) scenario utilizing existing copper infrastructure. Intensity modulation (IM) and heterodyne detection are implemented, combined with polarization division multiplexing (PDM) to double the system capacity. The uplink performance of FBMC-PON is emulated with two asynchronous ONT bands in transmission over 20 km single mode fiber (SMF). FBMC with prototype filters (PFs) PHYDYAS, extended Gaussian filter (EGF) and isotropic orthogonal transform algorithm (IOTA) is discussed in comparison with orthogonal frequency division multiplexing (OFDM) in terms of frequency guard band and multiple access interference (MAI). The laser from an external cavity laser (ECL) is split and shared among ONTs. The experimental results show that FBMC can achieve significant improved receiver sensitivity compared to OFDM in the asynchronous uplink. FBMC with PHYDYAS can avoid MAI with frequency guard interval of one time the subcarrier spacing. With optical receiving power (ROP) of −23 dBm, to support 2, 4 and 8 ONTs, the required optical power of the narrow linewidth laser is respectively 10, 16 and 22 dBm with bit error rate (BER) at the hard decision forward error correction (HD-FEC) threshold.

Enhanced Energy Savings with Adaptive Watchful Sleep Mode for Next Generation Passive Optical Network

A single watchful sleep mode (WSM) combines the features of both cyclic sleep mode (CSM) and cyclic doze mode (CDM) in a single process by periodically turning ON and OFF the optical receiver (RX) of the optical network terminal (ONT) in a symmetric manner. This results in almost the same energy savings for the ONTs as achieved by the CSM process while significantly reducing the upstream delays. However, in this study we argue that the periodic ON and OFF periods of the ONT RX is not an energy efficient approach, as it reduces the ONT Asleep (AS) state time. Instead, this study proposes an adaptive watchful sleep mode (AWSM) in which the RX ON time of ONT is minimized during ONT Watch state by choosing it according to the length of the traffic queue of the type 1 (T1) traffic class. The performance of AWSM is compared with standard WSM and CSM schemes. The investigation reveals that by minimizing the RX ON time, the AWSM scheme achieves up to 71% average energy saving per ONT at low traffic loads. The comparative study results show that the ONT energy savings achieved by AWSM are 9% higher than the symmetric WSM with almost the same delay and delay variance performance.

The architecture of hybrid mm-wave ARoF Super-PON system for 5G implementation

Fifth-generation mobile communications are delivering higher data rates and low latency services for costumer by utilizing the benefits of optical fiber. In this paper, we propose the architecture of a hybrid millimeter-wave (mm-wave) analog radio-over-fiber (ARoF) Super-PON optical network for future broadband service and the latest fifth-generation 5G/5G + cellular mobile communications. Our proposed infrastructure shows the trade-off between technology and costs where the optical access network architecture is technologically transformed to transport intermediate frequencies (IF) through the existing fiber optical distribution network (ODN) by integrating baseband units (BBUs) into optical line terminals (OLTs) and the remote radio units (RU) into optical network terminals (ONTs), leaving the traditional broadband architecture unchanged. Performance of investigated mm-wave ARoF Super-PON transmission systems in the C-band downlink scenario for both broadband and mobile service is shown. With the proposed hybrid architecture, it is possible to provide cost-effective deployment of future 5G/5G+ networks as 5G key performance indicators (KPIs) are met and increase PON’s utilization for multiple services by sharing frequency bands and infrastructure. Several intermediate frequencies in Ka-band (26.5 – 40 GHz) are addressed to evaluate the performance of our investigated ARoF Super-PON transmission system for each corresponding frequency in different scenarios of up to 50 km over standard single-mode optical fiber (SMF) link.

Planning, Design and Simulation of a Network Access Based on FTTH-EPON for Hadhramout University

In our country copper infrastructure from Central Office (CO) to the end user is responsible for delivering poor Broadband services with loss reach 86% of the overall capacity speed. Not to mention the high prices and the impact of this inferior service to the education and economy of the country. Therefore, This paper presents a procedural proposal solution for planning, design and simulation of Ethernet Passive Optical Network (EPON) performance through Fiber-to-the-Home (FTTH) technology applied on College Of Engineering and Petroleum campus at Hadhramout University as it the best way to overcome all the problems related with copper. Since the fiber terminates at the campus, we termed the network, Fiber To The Campus (FTTCampus). FTTCampus planning the location network was developed through Google Earth and AUTOCAD software which was implemented to map out the college location areas. The proposed optical network system design has been simulated based on EPON IEEE 802.3ah standards through Optisystem software program. Simulation network components such as optical transmitters, Optical network terminals (ONTs), and optical splitters among others were allocated at different coverage areas and various network links were connected among these coverage areas. A downstream network of EPON has been simulated using Continuous Wave Laser (CW Laser) and Directed-modulated Laser (DM Laser) as different optical. Validation was performed with consistent output performance indicators like quality factor, optical source power (dBm) and bit error rate (BER). This paper has a main objective in designing an affordable and feasible network and it is accomplished by utilizing EPON that merges the low-cost Ethernet technology and low-cost PON structure with the DM Laser as an optical source. This unique work revealed that, FTTCampus could be a reliable technology in an educational academic institution, if implemented.

Design, implementation and evaluation of a Fiber To The Home (FTTH) access network based on a Giga Passive Optical Network GPON

Requirements such as high bandwidth and capacity for high speed internet, High Definition Television “HDTV” and Voice Over Internet Protocol “VOIP”, lead to the proposals for Fibre To Home FTTH Access Network. FTTH based on Giga Passive Optical Network (GPON) technology is one techniques that can provide triple play services at a reasonable cost. It uses only passive equipment except at the central office and the customer premises. Most telecom operators now use FTTH networks based on GPON due to its flexibility in handling extended technologies and services in the future. For a GPON technology, a maximum of 128 uses can be included in a network with maximum reach of 60 ​km and maximum distance between consecutive optical network terminals of 20 ​km as per G.984.6 ITU-T specification. GPON uses 2.44 Gbps downstream and 1.24Gbps upstream data transmission.

A Green Converged TWDM-PON and 5G HetNet Catering Applications Demanding Low Latency

Abstract Integration of Passive Optical Network (PON) and wireless network technologies can offer a high data rate with ubiquitous Internet access to the end-users. Due to the growing importance of reducing the carbon footprint of telecommunication networks, energy-saving mechanisms are dispensed in the networking equipment. One of the commonly used approaches to reduce energy consumption is the “sleep mode” in which a network equipment periodically turns off some of its components so as to reduce energy consumption. Note that, the current PON and wireless access network technologies have their own power-saving modes. In order to gain power-saving and meet latency of applications in an integrated PON and wireless access network technologies, both optical and wireless access technologies need to have consent on how traffic management (bandwidth allocation, traffic forwarding path), as well as power-saving modes, should be managed in the network. That is, there needs to have synchronization of these two network segments. Otherwise, the end-users would experience longer delay and lower throughput. In this paper, we introduce a Delay-Aware Integrated Sleep Mode (DISM) solution designed considering 5G Heterogeneous Networks (HetNets) architecture which connected with core networks through Time and Wavelength Division Multiplexed Passive Optical Network (TWDM-PON). In particular, we propose a power saving mechanism using sleep mode for TWDM-PON taking into account packet forwarding delay from the optical network termination point to the end-users’ mobile terminal so as to maximize energy-saving in TWDM-PON while meeting latency requirements of applications with stringent latency requirements. Results obtained through simulations impart that our proposed scheme can significantly satisfy the delay requirement of the traffic while it can still reduce energy consumption in TWDM-PON. Furthermore, the results provide insights on how power saving mechanism in PON should be managed for such 5G HetNet and optical integrated networks in order to satisfy the latency requirement of the traffic.

A Framework for an Energy-Efficient Bandwidth Allocation Approach through Dynamic ONTs Grouping in Flexible GPON Access Networks

The growing demands for high speed connectivity to keep pace with bandwidth intensive applications and services have spawned the idea of developing PONs with capabilities beyond those of copper and wireless-based technologies in access network. In this article, an approach for the design of an energy efficient bandwidth allocation mechanism for the shared upstream communication link in the Fiber to the Home (FTTH) access network is presented and evaluated using Mixed Integer Linear Programming (MILP) model. In the MILP model, two objective functions for minimization of power consumption and minimization of blocking were evaluated. The results have shown that with the objective of power minimization approach, Optical Network Terminals (ONTs) are efficiently grouped to the minimum number of active networking Optical Line Terminal (OLT) switches, traffic is groomed, ports are efficiently utilized, and hence total power consumption is minimized. Results have shown that with energy efficient bandwidth allocation approach consideration, energy savings can reach up to 80% for different examined traffic loads following uniform distribution.

Improved self-seeding and carrier remodulation performance for WDM-PON by means of double RSOA erasure

In this work, we investigated a novel wavelength division multiplexing passive optical network (WDM-PON) configuration, based on cascaded reflective semiconductor optical amplifiers (RSOA) data erasure for combined self-seeding and wavelength reuse. Improved performance is achieved by enhanced erasure efficiency using a self-seeded double-RSOA cavity at the optical line terminal (OLT) and cascaded RSOAs at the optical network terminal (ONT). To carry out the study, our experimental results for our earlier combined topology layout operating at a symmetric transmission were used to validate the simulation framework for the proposed double-RSOA erasure configuration. Using our original single-cavity self-seeding WDM-PON architecture as a benchmark, downstream extinction ratio (ERD) margins of 6.5 dB and 9.0 dB are obtained, for generating self-seeded downstream signals and upstream remodulation, respectively. Also, bidirectional transmission of 1.25 Gb/s over links reach up to 45 km is achieved by the double-RSOA cavity, surpassing in 25 km our original combined topology. The results indicated that our proposition effectively addresses a fundamental trade-off for WDM-PONs based on the wavelength reuse and/or self-seeding techniques. Specifically, the double erasure procedure allows the use of relatively high levels of ERD, thereby providing improved bit error rate (BER) at the ONT, while assuring high-quality generation of the self-seeding carrier and loopback operation.

Desain JaringaniFiberiToiThe HomeiTeknologiiGigabit Passive Optical Network (Gpon) Menggunakan Optisystem Untuk Area Sukawati

A Planning for fiber optic network using optical simulation from STO to ONT (optical Network Termination) with the farthest distance of ± 6.22 km done in the area of Jl. Batuyang, Kangin Batubulan, Sukawati, with an estimated number of customers of 270 customers aiming to switch networks from Multi Services Access Network (MSAN) to Gigabit Passive Optical Network (GPON). Planning starts from the survey area that will be built by the network, determines the customer's estimation, estimates the placement of the device and determines the specifications of the device to be used. Planning starting from STO to ONT / customer uses an optical application which will result from planning in the form of PRx on ODP (Optical Distribution Pack), PRx on ONT and bit error rate. The results of the analysis carried out, the Rx power generated in the ODP with the farthest distance of ± 6.22 km, which is for measuring results -26,893 dBm while in the planning results can be as much as -22,744 dBm, and PRx in ONT obtained for measuring results while in the planning obtained a result of -24.722 dBm, from the PRx results obtained the attenuation value is still below the ITU-T G.984 standard which is -28 dBm. BER value (Bit Error Rate) that is produced with the farthest distance of ± 6.12 km is 3,33x10?19 bit/s, this value is below the standard, namely 10?9 bit/s, with this result, optical fiber network planning using an optical system is feasible.

Lossless WDM PON Photonic Integrated Receivers Including SOAs

The role of a semiconductor optical amplifier (SOA) for amplifying downstream traffic at optical network terminals (ONT) within a silicon-photonics integrated receiver in a high capacity passive optical network (PON) is investigated. The nearly traveling wave SOA effects are evaluated by considering fabrication and link loss constraints through numerical analysis and experimental validation. The impact of hybrid integration of a SOA chip on a silicon on insulator (SOI) photonic chip using the flip chip bonding technique on SOA design is evaluated through numerical analysis of a multi section cavity model. The performance of the proposed ONT receiver design employing twin parallel SOAs is evaluated experimentally on a 32 × 25 Gb/s OOK WDM transmission system considering cross gain modulation (XGM) and amplified spontaneous emission (ASE) constraints. The XGM impact is evaluated through 32 channel wavelength division multiplexing (WDM) transmission and a likely PON worst case scenario of high channel power difference (~10 dB) between adjacent channels. The impact of ASE is evaluated through the worst-case polarization condition, i.e., when all of the signal is coupled to only one. Successful transmission was achieved in both worst-case conditions with limited impact on performance. SOA results indicate that a maximum residual facet reflectivity of 4 × 10−4 for the chip-bonded device can lead to a power penalty below 2 dB in a polarization-diversity twin SOAs receiver.

Unconventional plastic optical fiber design for very short multimode fiber link.

We introduce a graded-index plastic optical fiber (GI POF) design for very short-distance household applications, in which the transmission quality is predominantly determined by system noise rather than the loss and bandwidth. The developed GI POF has strong mode coupling with low accompanying scattering loss, which is closely related to the specific microscopic heterogeneities in the core material. Such characteristic mode coupling significantly decreases reflection noise, improving the transmission quality compared with silica GI multimode fiber (MMF) for lengths below 30 m. Moreover, in the GI POF link, the transmission quality tends to improve with increasing fiber length, despite the increased loss and decreased bandwidth. This feature suggests that the system noise can be controlled by the microscopic heterogeneous properties of the GI POF for a very short MMF link, where the fiber loss and bandwidth are sufficiently low and high, respectively. This unconventional concept for optical-fiber design can advance fiber-optic communication in emerging applications in households located near optical network terminals.

Low-Noise Graded-Index Plastic Optical Fiber for Significantly Stable and Robust Data Transmission

Internet traffic continues to grow with the increase of network-connected smartphones, tablets, televisions, and monitoring devices in the Internet-of-Things (IoT) era. This trend will be significantly accelerated by the introduction of ultrahigh-definition (UHD) imaging technologies in various applications, and existing optical networks including datacenter networks are under urgent development to accommodate this traffic. However, optical fibers have not been introduced into households located in optical network terminal areas, even though UHD device connections require decompressed high-volume data transmission at more than 100 Gb/s, where a multilevel modulation scheme is vital. In UHD applications, very short optical cables (typically less than several meters) are connected and disconnected by consumers in a manner similar to metal interface cables. Under such conditions, a data transmission quality is predominantly limited by noise and instability rather than bandwidth and loss. Here, we propose low-noise graded-index plastic optical fibers (GI POFs) that enable significantly stable and robust data transmission through strong mode coupling, whose mechanism is fundamentally different from that of silica optical fibers. The low-noise GI POF link eliminates the need for the precise fiber alignment, angled fiber facets, and optical isolators typically used in conventional links. Our proposed GI POF material paves the way for quick optical fiber connections for multilevel UHD video transmission, becoming the first “capillaries of light” from optical network terminals in the IoT era.

Broadband Network Fiber to the Home (FttH) Design for Improving Performance of Information and Telecommunication Network in Riau University

Increased demand for information and telecommunications at the University of Riau demanding reliable carrier network availability. Copper cable network that now exists less support for multimedia network performance. Therefore, it is necessary to design a new access networks. One alternative is to implement fiber optic technology Fiber to the Home (FttH). This research design a FttH network for information access needs on the campus site, located in Panam, Pekanbaru. The results show the needs of Optical Network Terminal (ONT) as many as 209 units and 34 units of Optical Distribution Point (ODP), using passive splitter 1: 8 type of wall. Optical Distribution Cabinet (ODC) 1 unit to serve all the region in UR with a capacity of 24 core, using ODC 144 type. Calculation of the sample data taken, showing the speed of each customer in the Engineering Faculty using FttH is approximately 3 Mbps. Link Budget Calculations indicate that power received by each faculty on average -23.17 dB, it can be concluded FttH network design is feasible and appropriate ethical standards that have been determined shall not exceed -28 dB. Attenuation of each faculty obtained the average value of -21.17 dB.

Link Power Budget and Traffict QoS Performance Analysis of Gygabit Passive Optical Network

Data service of telecommunication network is needed widely in the world; therefore extra wide bandwidth must be provided. For this case, PT. Telekomunikasi Tbk. applies GPON (Gigabit Passive Optical Network) as optical fibre based on telecommunication network system. GPON is a point to a multipoint technology of FTTx (Fiber to The x) that transmits information signals to the subscriber over optical fibre. In GPON trunking system, from OLT (Optical Line Terminal), the network is split to many ONT (Optical Network Terminal) of the subscribers, so it causes path loss and attenuation. In this research, the GPON performance is measured from the link power budget system and the Quality of Service (QoS) of the traffic. And the observation result shows that the link power budget system of this GPON is in good condition. The link power budget values from the mathematical calculation and direct measurement are satisfy the ITU-T G984 Class B standard, that the power level must be between -8 dBm to -27 dBm. While from the traffic performance, the observation result shows that the network resource utility of the subscribers of the observed area is not optimum. The mean of subscriber utility rate is 27.985 bps for upstream and 79.687 bps for downstream. While maximally, It should be 60.800 bps for upstream and 486.400 bps for downstream.

Fiber Fault Localization in FTTH Using Online Monitoring

At present optical fiber cable is used as media to design network and it support high Band width in Gbps speed. Earlier OFC is used to connect the long distance places called OTN (Optical Transport Network) and presently used even in local/access network called OAN (Optical Access Network). Inorder to provides the broadband accessing the PON (Passive Optical Network) used which splits the voice and data at the customer end and this technique has been improved to GPON (Gigabit Passive Optical Network) which provides the higher data rate then the PON . It is also accessible in the Ethernet connectivity called GEPON (Gigabit Ethernet Passive Optical Network). GEPON/GPON/PON terminals used in between the ONT (Optical Network Terminal) and OLT (Optical Line Terminal) terminals.OLT is located at the service providers end and ONT is located at the customer end. Customers are required high QoS and BW and they interested to make SLA (Service Level Agreement) for their service which are expecting from the service providers. The biggest challenge is the maintenance of the network includes localization and identification cable fault in network that ensures maximum QoS.

In-Service Monitoring of PON Access Networks With Powerline Independent Devices

In this paper we describe and demonstrate a new remote in-service monitoring technique for passive optical access networks. New microwatt off-grid powered devices are introduced that may be installed at any location in the network. These monitors are equipped with a unique software-defined address, allow status monitoring of network parameters, facilitate the integration of remote active elements such as switches, and scale up easily to thousands of devices. Such monitors may be used to identify and measure the power levels and connection availability of a customer’s site independent of the subscribers’ optical network termination (ONT). Even physical disconnection of a rogue or erroneous ONT is demonstrated. A hardware implementation using off-the-shelf components together with a special communication protocol was successfully demonstrated in a gigabit passive optical network (GPON) testbed, where random data were transmitted. The lowest power consumption with less than 2 μW allows for powering with an optical supply channel or a small battery that lasts for a decade.

Design and Performance Analysis of Passively Extended XG-PON With CWDM Upstream

In this paper, we evaluate the design and performance of an entirely passive extended 10-gigabit-capable PON (XG-PON) using eight channels of coarse wavelength-division multiplexing (CWDM) in upstream transmission, which is called the Cu-XG-PON, with a first demonstration of the upstream physical layer specification for the extended class in ITU-T G.987 series of recommendations. In the new scheme, a single burst-mode receiver (BMRx) within an optical line terminal (OLT) receives arbitrary upstream data from the optical network terminals (ONTs) divided into eight groups, each group sharing a CWDM wavelength, through a CWDM filter and a power splitter as cascaded remote nodes (RNs) for the upstream link bridge. The downstream link is designed such that a high power OLT transmitter compensates for link loss using two power splitters as cascaded RNs. Based on the proposed architecture, we first analyze the overall system performance in the upstream and downstream links, and then evaluate the practical extension capabilities in terms of fiber distance and split ratio by conducting experiments to probe the upstream performance using a developed BMRx. We demonstrate that the BMRx is capable to -34.5 dBm sensitivity, which is feasible for a 36 dB optical path loss and a 0.5 dB optical path penalty with a 2 dBm ONT transmitter power. Based on the numerical analysis and experimental results, we confirm that the proposed Cu-XG-PON is capable of reaching 28 km for 256 ONTs, or 42 km for 64 ONTs, and furthermore, for ONT groups at long wavelength channels, maximum 40 km for 256 ONTs, or 60 km for 64 ONTs.