Search Results (16)

With the increasing number of end users that are using multimedia services, demand for access network high-bitrate systems with sufficient quality of services is also increasing. However, this might not always be ensured by telecom operators, as they must optimize networks according to the Quality of Service (QoS) and multimedia data transmission. In this work, we tested Gigabit Passive Optical Network (GPON) performance with the help of various tools (iPerf, RFC 6349 or ITU-T Y.1564). The Grafana software v7.3.3 tool is used to monitor data streams. Measurements were made to limit the downstream bitrate of up to 20 end users at 1 Gbit/s, 500 Mbit/s, 300 Mbit/s and 100 Mbit/s. Based on repeated measurements, an aggregation curve was modelled, indicating the available bitrate with respect to the network load. Full article

This study evaluates the performance of a hybrid passive optical network–radio over fiber (PON–RoF) architecture for long-term evolution (LTE)-based video transmission, focusing on the analysis of the block error rate (BLER) with and without an external RF amplifier. The results show that removing it improves receiver sensitivity by 4.04 dB in the optical link and 16 dB in the hybrid RoF link. The internal gain control of the USRP-2944R (Universal Software Radio Peripheral) is sufficient for signal processing without saturating the receiver. Furthermore, the received power levels are consistent with typical GPON sensitivity and overload ranges reported in standards, although the experimental setup corresponds to a continuous point-to-point laboratory link rather than a full GPON burst-mode configuration. Full article

With the growing global deployment of Fiber-to-the-Home (FTTH) networks driven by the demand for ensuring high-capacity broadband services, mobile network operators (MNOs) face challenges of excessive energy consumption (EC) of wired optical access networks (OANs). This paper presents a comprehensive review of methods aimed at improving the energy efficiency (EE) of wired access passive optical networks (PONs) and active optical networks (AONs). The most important energy management and power-saving methods for Optical Line Terminals (OLTs) and Optical Network Units (ONUs), as key OAN components, are overviewed in the paper. Special attention in the paper is further given to analyzing the impact of a constant increase in the number of subscribers and average data rate per subscriber on global instantaneous power and annual energy consumption trends of FTTH Gigabit PONs (GPONs) and FTTH point-to-point (P-t-P) networks. The analysis combines the real ONU/OLT device-level power profiles and the number of installed OLT and ONU devices with data traffic and subscriber growth projections for the period 2025–2035. A comparative EE analysis is performed for different MNO FTTH OAN architectures and technologies, point-of-presence (PoP) subscriber capacities, and GPON-to-P-t-P subscriber distribution ratios. The findings indicate that different FTTH PON and AON architectures, FTTH technologies, and PON-to-AON subscriber distributions can yield significantly different EE gains in the future. This review paper can serve as a decision-making guide for MNOs in balancing performance and sustainability goals, and as a reference for researchers, engineers, and policymakers engaged in designing next-generation wired optical access networks with minimized environmental impact. Full article

Time Division Multiplexing Passive Optical Networks (TDM-PONs) serve as a key enabler for the evolution of broadband access network infrastructure. As TDM-PONs adapt to support 6G networks, reducing energy consumption becomes increasingly critical. Sleep modes have been widely adopted as an effective energy-saving solution. However, their use can introduce delays that compromise performance. This issue becomes especially problematic in 6G PONs, where ultra-low latency and stringent service requirements leave minimal tolerance for delay-related inefficiencies. In this paper, we propose a novel sleep synchronization mechanism for both single and multiple TDM-PONs, allowing Optical Network Units (ONUs) to join one or more sleep/wake-up groups based on the service type and delay tolerance. Our practical design framework incorporates delay-based grouping and existing sleep modes to address the operational complexities of multi-PON systems while remaining fully compatible with current PON standards. The simulation results show that our approach satisfies the requirements of delay-sensitive traffic and achieves up to 37% energy savings. Compared to baseline methods such as adaptive scheduling and fixed-interval cyclic sleep, it offers a 15–20% improvement in the energy–delay trade-off. These results demonstrate the potential for near-term deployment of 6G PONs and lay the foundation for more advanced, delay-aware energy management strategies in next-generation optical access networks. Full article

The increasing demand for high-speed internet and advanced digital services necessitates the deployment of robust and scalable broadband infrastructure, particularly in smaller urban and rural areas. This paper presents the design and implementation of a passive optical network (PON) based on a gigabit-capable passive optical network (GPON) standard to deliver fiber-to-the-home (FTTH) services in a small-town setting. The proposed solution prioritizes cost-effectiveness, scalability, and minimal energy consumption by leveraging passive splitters and unpowered network elements. We detail the topology planning, splitter architecture, installation practices, and technical specifications that ensure efficient signal distribution and future network expansion. The results demonstrate the successful implementation of an optical access infrastructure that supports high-speed internet, Internet Protocol television (IPTV), and voice services while maintaining flexibility for diverse urban layouts and housing types. Full article

The capacity of passive optical networks (PONs) is continuously increasing, and it has been standardized up to 50 Gbit/s. The two main standardization organizations, IEEE and ITU-T, are actively working on the next-generation PON, which appears to be a 100G-PON still based on intensity modulation. Even though direct detection would be preferred for its cost and simplicity, the choice of coherent detection seems inevitable when the bit rate reaches 200–400 Gbit/s, specifically to guarantee the optical power budget requirement of an access network. The introduction of coherent systems in the PON scenario, allowing high-power-budget performances, should encouragetelecom operators to merge the metro and access networks into a single domain. This paper analyzes the mentioned metro + PON convergence scenario with experimental results focusing on a 400 Gbit/s fully coherent transmission (50 GBaud PM-16QAM). We characterize three different transceivers, two of which are pre-commercials. We perform experimental demonstrations, with real urban fiber and laboratory set ups, of the metro–access convergence network in terms of the minimum OSNR value of the metro path, producing an acceptable optical power budget within the access network. Our work demonstrates feasibility of merging the metro–access network by using currently coherent optical transceivers for PON applications. Full article

In ITU-T standards, auxiliary management and control channels (AMCCs), as defined, facilitate the rapid deployment and efficient management of wavelength division multiplexing passive optical network (WDM-PON) systems. The super-imposition of an AMCC introduces additional interference to a PON signal, resulting in the degradation of the performance of the overall transmission. In prior research, we proposed employing a Gaussian mixture model (GMM) to fit a baseband-modulated AMCC signal. Following the analysis of the interference model and the distribution characteristics of received signal errors, we propose a combined optimization method for a transmitter and receiver in this paper. This method, grounded in probabilistic shaping (PS) techniques, optimizes the probability distribution of the transmitted signal based on the AMCC interference model, with the objective of reducing the error rate in PON signal transmission. We have validated this approach within a 50G-PON experimental system by utilizing PAM4 modulation. The experimental results demonstrate the effectiveness of this method for mitigating the impact of baseband-modulated AMCC, thereby reducing the error rate in PON signal transmission. The approach presented in this paper can further minimize the performance degradation introduced by baseband-modulated AMCC in WDM-PON systems, enhancing the efficiency of WDM-PON deployment. Full article

For a 50G passive optical network (PON) low-density parity-check (LDPC) decoder, decoding performance and area efficiency must be balanced. This paper adopts a layered decoder method to improve the area efficiency of the decoder. By parallel processing of three submatrices and storage reuse of node information, optimizing the matrix partitioning and processing order of the 50G-PON standard, the throughput of 1235 bps was reached under 100 MHz circuit frequency in field-programmable gate array (FPGA) implementation, and 9.864 Gbps was achieved based on Taiwan semiconductor manufacturing company (TSMC) 65 nm synthesis with 800 MHz circuit frequency in an area of 2.61 mm${}^2$ by proposing a mechanism of spare decision storage to avoid errors caused by quantization overflow of the decoder and using full verification to terminate decoding in advance to improve performance. Finally, at an input bit error rate (BER) of $2.3\times {10}^{-2}$ (signal-to-noise ratio (SNR) of about 3.72 dB), the output BER was lower than ${10}^{-12}$, and the throughput area rate (TAR) also increased by 2 to 4 times compared with other papers. In conclusion, an area-efficient LDPC decoder without sacrificing decoding performance is made. Full article

The integration of Software Defined Networking (SDN) technologies in Passive Optical Networks (PONs) would provide great advantages to Internet Service Providers (ISPs) and Network Operators, since they can optimize the network operation and reduce its complexity. However, some tasks regarding online service and network configuration strategies are difficult to move to external SDN-controllers since they are time-critical operations. However, the control of some of these policies by SDN techniques could lead to better network and management configuration in a centralized and automatic way. As a consequence, we propose and experimentally test the integration of an OpenFlow approach over legacy Gigabit Passive Optical Networks (GPONs), which allows moving some global service configuration policies to an external SDN controller implementing an SDN management layer that adjust these strategies according to dynamic Quality of Service (QoS) requirements of services in residential users. The viability and efficiency of our approach are demonstrated using a GPON testbed and proposing a new business scenario for ISPs and Network Operators. Full article

This paper discusses the possibility of analyzing the orchestration protocol used in gigabit-capable passive optical networks (GPONs). Considering the fact that a GPON is defined by the International Telecommunication Union Telecommunication sector (ITU-T) as a set of recommendations, implementation across device vendors might exhibit few differences, which complicates analysis of such protocols. Therefore, machine learning techniques are used (e.g., neural networks) to evaluate differences in GPONs among various device vendors. As a result, this paper compares three neural network models based on different types of recurrent cells and discusses their suitability for such analysis. Full article

This work is focused on creating an open-source software-based solution for monitoring traffic transmitted through gigabit passive optical network. In this case, the data are captured by the field-programmable gate array (FPGA) card and reassembled using parsing software from a passive optical network built on the International Telecommunication Unit telecommunication section (ITU-T) G.984 gigabit-capable passive optical network GPON recommendation. Then, the captured frames are converted by suitable software into GPON frames, which will be further processed for analysis. Due to the high transfer rate of GPON recommendations, the work describes the issue of writing to the Mongo database system. In order to achieve the best possible results and minimal loss of transmitted frames, a series of tests were performed. The proposed test scenarios are based on different database writing approaches and are implemented in the Python and C# programming languages. Based on our results, it has been shown that the high processing speed is too high for Python processing. Critical operations must be implemented in the C# programming language. Due to rapid application development, Python can only be used for noncritical time-consuming data processing operations. Full article

For many years, passive optical networks (PONs) have received a considerable amount of attraction regarding their potential for providing broadband connectivity to almost every citizen, especially in remote areas where fiber optics can attract people to populate regions that have been abandoned. Error-free connectivity without dropouts can offer new opportunities to communicate, earn money and enjoy cultural events. Transmission speeds are multigigabit with distances of a few tens of kilometers; these specifications were previously reserved for high-speed and long-haul backbone networks. PONs can also support a new class of applications, such as accurate time transfer or distributed fiber sensing and follow new trends in open networking. An outline of past and current standards and standards that have been proposed for the latest generation of multigigabit PONs is provided. Full article

This work presents a reconfigurable RF converter for DVB-T television applications using triple-play over GPON. The system takes the DVB-T input, a wavelength division multiplexing (WDM) signal with spectral inversion in the range from 47 $\mathrm{M}$ $\mathrm{Hz}$ –1000 $\mathrm{M}$ $\mathrm{Hz}$ , up-converts its frequency to the band-pass of a highly selective surface-acoustic wave (SAW) filter centered at $1.3$ $\mathrm{G}$ $\mathrm{Hz}$ , and then down-converts it so that it is compatible with the antenna input of conventional television sets. The designed RF converter incorporates two pairs of frequency synthesizer and mixer, based, respectively, on an integer-N phase-locked loop (PLL) with two LC-tank VCOs with 128 coarse tuning bands in the range from 1.35 $\mathrm{G}$ $\mathrm{Hz}$ –2.7 $\mathrm{G}$ $\mathrm{Hz}$ , and a double-balanced Gilbert cell, modified for better impedance matching and improved linearity. It is fed with regulated supplies compensated in temperature and programmed by an I ${}^2$ C interface operating on five 16-bit registers. This work presents the experimental characterization of the whole system plus selected cells for stand-alone testing, which have been fabricated in a $0.18$ $\mathrm{m}$ CMOS process. Full article

This article presents a design of a database model used to gather and analyze data frames transmitted over gigabit passive optical network (GPON) in the downstream direction. An issue with this kind of system is the difficulty in analyzing a transmission on the optical part which is caused by the difference among devices using Ethernet frames technology and passive optical network technology with usage gigabit encapsulation method. In this article, a principle of the downstream direction is described. Next, the design of the database model for the analysis of transmitted data is discussed. Based on the design and implementation of the database, a script capable of processing data gathered by a programmable network card is proposed. The script for physical layer operation, admission, and maintenance (PLOAM) messages analysis is written in the Python programming language. Full article

Platelet interaction with collagens, via von Willebrand factor, is a potent trigger of shear-dependent thrombus formation mediated by subsequent engagement of the signaling collagen receptor glycoprotein (GP)VI, enforced by integrin α₂β₁. Protein tyrosine kinase Syk is central in the GPVI-induced signaling pathway, leading to elevated cytosolic Ca²⁺. We aimed to determine the Syk-mediated thrombogenic activity of several collagen peptides and (fibrillar) type I and III collagens. High-shear perfusion of blood over microspots of these substances resulted in thrombus formation, which was assessed by eight parameters and was indicative of platelet adhesion, activation, aggregation, and contraction, which were affected by the Syk inhibitor PRT-060318. In platelet suspensions, only collagen peptides containing the consensus GPVI-activating sequence (GPO)_n and Horm-type collagen evoked Syk-dependent Ca²⁺ rises. In whole blood under flow, Syk inhibition suppressed platelet activation and aggregation parameters for the collagen peptides with or without a (GPO)_n sequence and for all of the collagens. Prediction models based on a regression analysis indicated a mixed role of GPVI in thrombus formation on fibrillar collagens, which was abolished by Syk inhibition. Together, these findings indicate that GPVI-dependent signaling through Syk supports platelet activation in thrombus formation on collagen-like structures regardless of the presence of a (GPO)_n sequence. Full article