Fiber Access Research Articles

Signal quality comparison of customer base and branching methods in fiber to the home network design

One communication medium that is well-known for its outstanding and reliable performance is fiber optic. A social example of its application is the Fiber to the Home (FTTH) network. The goal of this study is to evaluate the signal quality of the customer base method and the branching method, two FTTH-building techniques based on the PT.PLN Icon Plus standards, in order to identify the most practical approach for use in the Air Hitam 2 cluster. Two scenarios were used in this study at the Fiber Access Terminal (FAT) with 1:16 and 1:8 splitters. The fiber optic cable path design findings demonstrate that the branching approach is a wise decision, utilizing optical fiber cables for a total of 9 Km, with the greatest cable distance being 2.5 Km from the Optical Line Terminal (OLT) to the end FAT. According to theory, in the 1:16 splitter situation and the 1:8 splitter scenario, the optical power received by the Optical Network Terminal (ONT) is -19.13 dBm and -16.03 dBm, respectively, with an OLT transmit power of 3 dBm. For these cases, the simulation results are -17.98 dBm and -20.27 dBm. Additionally, the budget value for the rising time reaches 0.253 ns. The bit error rate values in the 1:16 and 1:8 splitter scenarios are 3.157 × 10-10, and 1.63507 × 10-28, respectively, while the Q factor values are 6.18233 and 11.014, respectively. Based on theory and simulation, these findings suggest that the branching strategy can deliver good performance.

The divide between us: internet access among people with and without disabilities in the post-pandemic era

The COVID-19 pandemic highlighted the importance of internet access across various aspects of life, from remote work and online education to healthcare services and social connections. As we transition to a post-pandemic era, a pressing need arises to update our understanding of the multifaceted nature of internet access. This study is one of the first attempts to do so. Using survey data from New Zealand adult internet users (n = 960), it compares internet connection types, frequency of internet use at home, social media use, and concerns about online risk between people with and without disabilities. Results show people with disabilities have restricted fibre access and higher wireless broadband (a much slower connection type). People with disabilities use social media platforms less and are more concerned about certain online risks. The findings highlight persistent disparities in internet access for people with disabilities in the post-pandemic era. Implications of the study are discussed.

Enabling cost-effective wireless THz communication through semiconductor optical amplifier’s direct/cross gain modulation for seamless integration of hybrid fiber-coaxial connectivity

We propose a cost-effective THz wireless communication scheme for future femtocell networks that leverages either direct gain modulation (DGM) or cross gain modulation (XGM) of a semiconductor optical amplifier (SOA) to convert coaxially or optically carried data into intensity-modulated THz waves, respectively. This architecture, based on an SOA and a uni-traveling-carrier photodiode (UTC-PD), has advantages over typical THz modulation schemes involving a resonant tunneling diode or an electro-optic modulator combined with a UTC-PD. Consequently, it facilitates the seamless convergence of hybrid fiber-coaxial networks to THz radio access networks with low cost, straightforward monolithic integration, and a more compact footprint. Furthermore, we experimentally verified the possibility of non-return-to-zero on–off keying wireless communication over 0.5 m in the 300 GHz band, achieving real-time transmission of 4 Gbit/s for coaxial access via an SOA’s DGM and 10 Gbit/s for fiber access via the SOA’s XGM. Notably, these data rates were attained by simple non-coherent THz intensity demodulation based on a Fermi-level managed barrier diode while meeting the 7% hard-decision forward error correction (HD-FEC) threshold (3.4×10−3). Finally, we conducted an analysis of the merits and drawbacks of the proposed THz communication scheme based on the combination of an SOA and a UTC-PD, discussed bottlenecks that hinder further rate improvement, and explored possibilities for optimization. In conclusion, this scheme is crucial for realizing future ultra-high-speed wireless networks that seamlessly connect to fiber-coaxial networks.

B-ROS re-balanced learning method for PS-A-RoF FWA communication

The enhanced remote area communication (eRAC) scenario is an important growth point in the communication market. In some remote areas where optical fiber access cannot be realized or the laying cost is too high, fixed wireless access (FWA) is an appropriate supplementary solution for eRAC. Adopting analog radio over fiber (A-RoF) technology to implement FWA can overcome the bandwidth limitation of electronic devices and realize high-frequency carrier communication economically to achieve high-capacity wireless communication. Also, probabilistic shaping (PS) technology can be combined with A-RoF to further improve the flexibility of the network and coverage of service provision. However, in the PS-A-RoF network, the high RF power introduces more undesired nonlinear effects into the network, and it is often necessary to deploy supervised machine learning (ML) compensation modules in wireless receivers (WRs). But the module performances are affected by the uneven probability distribution of PS-QAM constellation points. In this paper, we employ the PS-A-RoF nonlinear model to theoretically investigate the correlation between the distribution of training symbols and the wireless A-RoF system’s performance. Our analysis reveals that reducing the variance of training symbol power contributes to a lower BER in the A-RoF network. We introduce a borderline random over-sampling (B-ROS) that matches with the PS-A-RoF nonlinear model, instead of the mainstream ROS, which is only at the data level. Based on the B-ROS scheme, only the minority examples below the borderline are over-sampled to reach a better variance performance. Introducing the B-ROS method into the supervised complex value nonlinear compensation module can further improve the decision accuracy of WRs with the restoration of phase information, without increasing additional computational resource consumption. The vector noise power, training symbol power variance, and noise factor metrics have been calculated to optimize the borderline value of our ML-based approach. We also present experimental data on the proof-of-concept A-RoF experiment for PS-64QAM. The results demonstrate a promising nonlinear compensation performance of the B-ROS WR, and the optimal borderline agrees well with the one deduced from the theoretical model under certain transmission conditions. Our proposed B-ROS scheme lessens the training size demand and can improve the receiver sensitivity by 0.51 dB compared to the common ML-based WR and by 0.7 dB compared to the conventional ROS scheme.

Hybrid hierarchical aggregation with semi dynamic optical line terminal distribution algorithms optimization for ethernet passive optical networks

The goal of hybrid fiber-wireless (Fi-Wi) access networks is to ubiquitously integrate the accessible vast amounts of optical network bandwidth with wireless network mobility at minimal cost and simple network installation. Fi-Wi networks can employ both Radio over Fiber (RoF) and Radio and Fiber (R&F) technologies. The difference between them is that R&F uses two MAC controls: one for optical fiber and one for wireless networks. One can reduce interference within the wireless subnetwork while avoiding the negative effects of fiber optic propagation delays on the network. RoF, on the other hand, uses MAC control for both optical and wireless networks, resulting in network latency and congestion. This paper demonstrates (i) the use of semi-dynamic bandwidth allocation and (ii) the use of hierarchical frame aggregation for access in next-level integrated Ethernet passive optical network EPON/WLAN-based generations and presents the ongoing research to improve the Quality of Service in wireless and fiber access networks. The study includes an offered load up to 10 Gbps, reaching the up-to-date levels. The obtained results reveal that the data, voice, and video latency are reduced, respectively, by 35%, 25%, and 30%. At the same time, the corresponding throughput is increased, respectively, for data, voice, and video by 35%, 25%, and 30%.

Optimized Lytic Polysaccharide Monooxygenase Action Increases Fiber Accessibility and Fibrillation by Releasing Tension Stress in Cellulose Cotton Fibers.

Lytic polysaccharide monooxygenase (LPMO) enzymes have recently shaken up our knowledge of the enzymatic degradation of biopolymers and cellulose in particular. This unique class of metalloenzymes cleaves cellulose and other recalcitrant polysaccharides using an oxidative mechanism. Despite their potential in biomass saccharification and cellulose fibrillation, the detailed mode of action of LPMOs at the surface of cellulose fibers still remains poorly understood and highly challenging to investigate. In this study, we first determined the optimal parameters (temperature, pH, enzyme concentration, and pulp consistency) of LPMO action on the cellulose fibers by analyzing the changes in molar mass distribution of solubilized fibers using high performance size exclusion chromatography (HPSEC). Using an experimental design approach with a fungal LPMO from the AA9 family (PaLPMO9H) and cotton fibers, we revealed a maximum decrease in molar mass at 26.6 °C and pH 5.5, with 1.6% w/w enzyme loading in dilute cellulose dispersions (100 mg of cellulose at 0.5% w/v). These optimal conditions were used to further investigate the effect of PaLPMO9H on the cellulosic fiber structure. Direct visualization of the fiber surface by scanning electron microscopy (SEM) revealed that PaLPMO9H created cracks on the cellulose surface while it attacked tension regions that triggered the rearrangement of cellulose chains. Solid-state NMR indicated that PaLPMO9H increased the lateral fibril dimension and created novel accessible surfaces. This study confirms the LPMO-driven disruption of cellulose fibers and extends our knowledge of the mechanism underlying such modifications. We hypothesize that the oxidative cleavage at the surface of the fibers releases the tension stress with loosening of the fiber structure and peeling of the surface, thereby increasing the accessibility and facilitating fibrillation.

Application of no-light fault prediction of PON based on deep learning method

The increased demand for broadband communication services has led to a wider deployment of fiber in the last mile. However, this expansion comes with the challenge of high maintenance costs for optical networks. To address this issue, there is a need for cost-efficient and reliable monitoring solutions that can detect and locate faults in different fiber access architectures. One specific concern in the operation of Passive Optical Networks (PONs) is the occurrence of no-light faults in the PON ports. To tackle this practical problem, we propose an intelligent scheme based on Long Short-Term Memory Networks (LSTMs) and Gated Recurrent Units (GRUs). These deep learning models are trained on historical data of the Optical Line Terminal (OLT) and PON behavior to predict future fault occurrences in real-time. To evaluate the performance of our proposed scheme, we conducted extensive experiments using real-world data. The results demonstrate the superiority of our approach over traditional methods and state-of-the-art models, as evidenced by improved accuracy, precision, recall, and F1 measure.

High-yield production of rod-like and spherical nanocellulose by controlled enzymatic hydrolysis of mechanically pretreated cellulose

In this study, a simple and scalable mechanical pretreatment was evaluated as means of enhancing the accessibility of cellulose fibers, with the objective of improving the efficiency of enzymatic reactions for the production of cellulose nanoparticles (CNs). In addition, the effects of enzyme type (endoglucanase – EG, endoxylanase – EX, and a cellulase preparation – CB), composition ratio (0–200UEG:0–200UEX or EG, EX, and CB alone), and loading (0 U–200 U) were investigated in relation to CN yield, morphology, and properties. The combination of mechanical pretreatment and specific enzymatic hydrolysis conditions substantially improved CN production yield, reaching up to 83 %. The production of rod-like or spherical nanoparticles and their chemical composition were highly influenced by the enzyme type, composition ratio, and loading. However, these enzymatic conditions had minimal impact on the crystallinity index (approximately 80 %) and thermal stability (Tmax within 330–355 °C). Overall, these findings demonstrate that mechanical pretreatment followed by enzymatic hydrolysis under specific conditions is a suitable method to produce nanocellulose with high yield and adjustable properties such as purity, rod-like or spherical forms, high thermal stability, and high crystallinity. Therefore, this production approach shows promise in producing tailored CNs with the potential for superior performance in various advanced applications, including, but not limited to, wound dressings, drug delivery, thermoplastic composites, 3D (bio)printing, and smart packaging.

Fiber to The Home (FTTH) Network Design Using Gigabit Passive Optical Network (GPON) Technology Using Link Power Budget and Rise Time Budget Analysis in Cibeber Village Tasikmalaya

Fiber optic is a transmission medium that can transmit information with large capacity. One of the developments in local fiber access networks is FTTH (Fiber to The Home). The construction of the FTTH network uses Gigabit Passive Optical Network (GPON) technology so that it can provide broadband services to customers with a wider range. This research was studied by designing FTTH based on GPON technology in Cibeber Village, Manonjaya District. The existing condition of the FTTH network in Cibeber Village is that there are 2 Optical Distribution Points (ODP) for 20 customers with each ODP having 10 subscribers. From the results of the location survey by measuring the distance to each customer, the furthest distance to the customer for the two ODPs was obtained, so that 2 new ODPs were needed for the design. From the design of the new optical network infrastructure, it has been analyzed using the link power budget and rise time budget method based on the customer with the farthest distance before the addition of ODP has a Power Receive sensitivity of -16.631 dBm to -15.631 dBm on the uplink and -16.644 dBm to -15.574 dBm on the downlink, these results are in accordance with the expected standard, which ranges from -8 dBm to -27 dBm. In calculating the value of the rise time budget for customers after the addition of ODP, it has a value of 0.2044 ns to 0.2039 ns on the uplink and 0.2188 ns to 0.21574 ns on the downlink. This value is still below the standard time limit set by PT. Telkom Indonesia 0.56 ns for uplink and 0.292 ns for downlink. So based on this the results of the design are feasible to implement.

The South Korean case of deploying rural broadband via fiber networks by implementing universal service obligation and public-private partnership based project

Despite broadband being essential infrastructure for conducting basic socio-economic activities and reducing inequality and the digital divide, expanding broadband coverage in rural areas remains a significant challenge in many countries due to high deployment costs. South Korea, a developed country in terms of fixed broadband penetration, implemented two policies for rural broadband via fiber access networks simultaneously during the COVID-19 pandemic. One is the universal broadband service at 100 Mbps speed introduced in 2020, and the other is the rural broadband project in terms of a public-private partnership (PPP) that proceeded from August 2020 to 2022. While both policies contribute to reducing the broadband gap between the urban and the rural in the country, it is still important to find the optimal cost-effective combination of the plural rural policies as much as possible from the cost perspective. Accordingly, this study proposes an investment cost estimation model for deploying rural broadband via fiber networks in South Korea and evaluates whether implementing two rural broadband policies in the country is cost-effective. The proposed model is designed according to the bottom-up approach, which involves building an efficient network with the latest technologies; thus, it gives a more accurate and reliable estimation of the investment cost of building rural broadband in the South Korean territory. The significant findings of this study are twofold. First, the PPP-based project could make the participating internet service providers (ISPs) deploy broadband at a cost-effective level, similar or lower to the universal service, and then recover the investment cost per building within a reasonable period. Thus, the result implies that governments need to consider the PPP-based project as an effective measure to deploy rural broadband, in addition to the introduction of universal service. Implementing multiple broadband policies to expand rural broadband coverage could be a reasonable and practical approach to improving broadband availability. Second, the governments still needs to make efforts to solve the complicated difficulties in rural areas in South Korea where rural-related broadband policies are still challenging to implement. This study confirmed that in some regions, the PPP-based project was still inferior to universal service in terms of average investment cost. In contrast, universal service had significant constraints to providing broadband because of the end-users cost burden, resulting in low broadband adoption. Therefore, the government needs to consider some measures to increase broadband availability and broadband adoption, such as widening the rural areas under the jurisdiction of participating ISPs, decreasing the proportion of participating ISPs bearing the investment cost of deploying broadband, and improving the cost burden of the end-users of universal service in some limited areas.

Sustainable production and evaluation of the properties of polyester-okra blended knitted fabric

The demand for fashionable knit fabric is increasing. Besides that, blended knit fabric, prepared from the blended yarn as well as using different types of yarn is also very popular to the modern customer. That's why, finding of new resource of raw material for fashionable knit fabric preparation is promising in the recent decade. Okra fiber is a biodegradable long staple bast fiber that can be obtained from abundant natural fiber sources after being extracted from lady's finger plants. It has high cellulosic content, worthy strength and modulus, and better thermal properties, making it a potential candidate as a raw material for the creation of stylish knit fabrics. Because of its rigidity and lack of flexibility, okra fiber cannot be spun into yarn on its own. In the current study, 1 × 1 rib fabric prepared from 30 Tex polyester/okra (PO) blended yarn of 80/20 and 85/15 blend ratio. For better comparison corresponding polyester/flax traditionally known as polyester/linen (PL) blended 1 × 1 rib fabric was also prepared. Current study found that, fabric characteristics, such as fabric weight, fabric dimension, air permeability, and bursting strength of PO blended fabric was compatible with PL blended fabric, with the exception of the fabric's hand feel characteristics. The overall findings revealed that the knit fabric qualities of PO mixed fabric were satisfactory. Due to the affordability and accessibility of okra fiber, the PO blended fabrics are very promising, sustainable and may be a viable choice to address the actual need for blended fabrics in the textile knitting industries.

Integrating clinical access limitations into iPDT treatment planning with PDT-SPACE.

PDT-SPACE is an open-source software tool that automates interstitial photodynamic therapy treatment planning by providing patient-specific placement of light sources to destroy a tumor while minimizing healthy tissue damage. This work extends PDT-SPACE in two ways. The first enhancement allows specification of clinical access constraints on light source insertion to avoid penetrating critical structures and to minimize surgical complexity. Constraining fiber access to a single burr hole of adequate size increases healthy tissue damage by 10%. The second enhancement generates an initial placement of light sources as a starting point for refinement, rather than requiring entry of a starting solution by the clinician. This feature improves productivity and also leads to solutions with 4.5% less healthy tissue damage. The two features are used in concert to perform simulations of various surgery options of virtual glioblastoma multiforme brain tumors.

China Telecom’s Research and Applications of Business-Enterprise Full-Optical Networking

With the continuous development of optical fiber access and other network infrastructure, cloud conference, online education, online office, cloud VR and other innovative services requiring high bandwidth are widely developed, which puts forward higher requirements on network bandwidth, delay, jitter and stability. Upgrading the legacy optical fiber network, building a gigabit optical broadband network, and promoting the further extension of optical fiber network to the enterprises help to improve the operation efficiency of information infrastructure and solve the problem of network coverage. High-quality business and enterprise broadband services can be realized, which stimulate potential consumer demand, and lay a solid foundation for the sustainable development of internet services. The business-enterprise full-optical network technology and the applications are studied, the related industrial chain and standardization progress are introduced, and the application mode and development trend are analyzed in this paper.

Simultaneous microwave-assisted phosphotungstic acid catalysis for rapid improvements on the accessibility and reactivity of Kraft-based dissolving pulp

Improving the cellulose accessibility and reactivity in an efficient and convenient way has become the focused issue in the field of dissolving pulp manufacturing. We herein demonstrate a simple yet efficient strategy, namely a simultaneous microwave (MW)-assisted phosphotungstic acid (PTA) catalysis (MW-PTAsim). The MW-PTAsim treatment was efficient to improve Fock reactivity from 49.1 % to 85.8 % and decrease viscosity from 561 to 360 mL/g within 10 min, which was superior to the single MW treatment and the sequential MW-PTAseq treatment. Besides, the MW-PTAsim treated fiber had rougher and more fibrillated surfaces with an enhanced fiber accessibility, showing increased specific surface area (SSA) from 1.43 to 6.31 m2/g, mean pore diameter (MPD) from 6.92 to 11.20 nm and water retention value (WRV) from 101 % to 172 %. These positive enhancements are mainly due to a synergy that MW-enhanced rotation of PTA mediums was served as “spinning cutters” to attack the fibers, plus MW-accelerated PTA transfer and catalytic hydrolysis further improved the fiber accessibility. Moreover, PTA also demonstrates a high reusability and chemical stability. This process offers an effective and sustainable alternative for manufacturing a premium dissolving pulp.

Development of Gis and Web Maps in Order to Extend Water Supply and Sewerage Infrastructure in Lechința Village, Iernut Town, Mureș County

In Romania’s most rural parts, the urban networks are not sufficiently developed. In order to improve the living standards of the inhabitants of Lechinta village, Iernut city, Mures county, it is necessary to extend water supply and sewerage infrastructure. For a better visualization and understanding of the interest area, a database was created in which the constructions, buildings, electrical and optical fiber networks, infrastructure and access ways were digitized. Considering the created database and the digital elevation model of the terrain, it was possible to easily design the water supply and sewerage infrastructure that allowed a better management of the field measurements. In order to ensure a higher degree of details, but also to complete and verify the measurements made with GPS receivers, photogrammetric and LiDAR data were obtained using a UAS equipped with the TopoDrone LiDAR 100 Lite sensor and the Zenmuse X4S DJI camera. The field data were imported into the ArcGIS application and analyzed in order to achieve the water supply and sewerage infrastructure. In order to visualize the digitization of the elements in the field, web maps were made using ArcGIS online application. The first map allows a 3D view of the area of interest and the second map includes 5 applications: database visualization, selection of desired layers, determination of distances and surfaces, use of different basemaps as well as sharing information through email, Facebook, etc. Database and webmaps that were created contribute to an easier design of urban networks and the visualization of the land in real time.

Effects of Lipase and Xylanase Pretreatment on the Structure and Pulping Properties of Wheat Straw.

Based on the reduction of environmental pollution, a biological enzyme assisted alkali-oxygen pulping method was explored to improve the delignification efficiency and fiber accessibility of wheat straw and improve the properties of wheat straw pulp. In this paper, lipase and xylanase were used to pretreat wheat straw and the effects of different enzyme types and enzyme dosage on the microstructure and pulp properties of wheat straw were investigated and experimented. The results showed that the lipase can remove fat and wax on the surface of wheat straw, while xylanase degraded the hemicellulose components, such as xylan, of wheat straw fiber, destroyed the structure of the lignin-carbohydrate complex, increasing lignin removal as a result and enhancing the impregnating, diffusion and penetration of alkali. Compared with wheat straw without enzyme pretreatment, the skeleton of wheat straw pretreated by enzyme became looser, the internal cavity appeared and the wall cavity became thin and transparent. The fines decreased obviously and the length of fibers increased. After combined pretreatment with lipase (15 U·g-1) and xylanase (15 U·g-1), the pulping performance of wheat straw was improved and the tensile index (97.37 N·m·g-1), brightness (40.9% ISO) and yield (58.10%) of the pulp increased by 12.9%, 19.9% and 9.9%, respectively. It can be seen that enzyme pretreatment is a green and effective approach to improving the alkali-oxygen pulping performance of wheat straw.

Evaluation of mechanical and physical properties of coconut fibre biocomposite reinforced with soya adhesive

In the present study, the investigation is to analyse the probability of using natural fibre-reinforced composites for structural applications. The availability, ample accessibility, and low cost of natural coconut fibres have gained their commercial value for some applications, such as panels, ceilings, partition boards, and automotive components. Coconut fibres (10, 20, and 30 mm) of 15% by weight and soybean adhesive of 85% of weight coconut fibre bio-composites (CFC) were manufactured. CFC-10, CFC-20, and CFC-30 are the different samples prepared by varying the size of the coconut fibres, respectively. Physical properties such as thickness swelling, water absorption, and mechanical properties such as flexural strength, and tensile strength were analysed. It was found that the CFC-10 composite is showing better results. As compared to the other natural fibres, it is observed that coconut fibres have given better results in both mechanical and physical aspects.

Oxidative delignification: The roles of lignin reactivity and accessibility

This study compared oxidative delignification of birch kraft pulp fibers to pulp fibers from acid hydrotropic fractionation (AHF) using p-toluenesulfonic acid (p-TsOH). Under oxygen delignification at 20% consistency, AHF pulps with lower hemicellulose content showed higher delignification than kraft pulps with similar lignin content despite its residual lignin (cellulosic enzymatic lignin, CEL) being less reactive with fewer β-O-4 ether aryl linkages based on 2D13C-1H nuclear magnetic resonance (NMR) spectroscopy. The water retention value (WRV) of AHF pulp fibers, a measure of fiber accessibility to water or oxidative chemicals, was substantially greater than that of kraft pulp fibers. Similar comparison of various AHF pulps further suggested that fibers with lower hemicellulose content were easier to delignify (bleach) despite having more lignin with lower reactivity (fewer β-O-4 linkages). Additionally, the present study also indicated that oxygen delignification was more effective at high fiber consistency, which can be attributed to thinner water films on the fiber surfaces at higher fiber loadings. These results indicated that mass transfer was the rate controlling process in oxidative delignification of wood fibers.

Holocellulosic fibers and nanofibrils using peracetic acid pulping and sulfamic acid esterification

Cellulose provides promising alternatives to synthetic plastics to achieve a low carbon footprint and biodegradable materials, which have significant positive impacts on environmental protection and on human health. In this work, sulfated holocellulose fibers and sulfated holocellulose nanofibrils (SHCNFs) are prepared using a combination of delignification with derivatization to achieve high fiber yield, superior recycling performance, and less energy consumption of the final products by means of preserving hemicellulose. Derivatization of the surface with sulfate groups provides a further means to avoid excessive aggregation between adjacent cellulose surfaces. Interestingly, hemicellulose increases the accessibility of holocellulose fibers and reduces the embodied energy during sulfate esterification. The presence of hemicellulose imparts high optical transmittance, mechanical performance (ultimate strength, 390 MPa; Young's modulus, 33 GPa), and recyclability for SHCNFs. This combination of two treatments can unlock the greater potential of cellulose as a sustainable material over its entire life cycle.

Integrated Fiber-FSO WDM Access System with Fiber Fault Protection

In this study, we propose a new wavelength-division-multiplexing passive optical network (WDM-PON) system to support the blended fiber-free space optics (FSO) signal access. To provide the fiber and FSO traffics simultaneously, the C- and L-band channels are applied in the presented PON, respectively. Moreover, to avoid the fiber breakpoint in the fiber access traffic, the proposed WDM access architecture also can provide the self-restored mechanism by applying simple fiber routing path. In addition, the corresponding signal performances of fiber and FSO channels are also executed experimentally for demonstration.