Optimization of emerging extended FTTH WDM/TDM PONs and financial overall assessment

Optical access technology has experienced a boost in the last years, thanks to the continuously migrating multimedia services that are offered over the internet. Though the technologies used for deploying Fiber-To-The-x (FTTx) and Fiber-to-the-Home (FTTH) are mostly based on either Active solutions or as far as Passsive Optical Networks (PONs) is concerned, in Time Division Multiplexing (TDM), an evolution towards Hybrid solutions such as Wavelength Division Multiplexing/Time Division Multiplexing (WDM/TDM) can be foreseen. What needs to be researched and finally established are the exact designs for this important step of integration, which should be optimized in terms of transmission performance and cost, to address all requirements of next-generation passive optical networks. As the most critical elements in optical access network, the design and its cost are the main topics of this discussion. The covered topics span over a wide range and include cost estimation of several optical network technologies - architectures and their comparison and furthermore, subjects of design optimization. In this last category, in-line remote amplification, use of an alternative and an extended frequency band, dispersion compensation and equalization techniques have been examined as well as a combination of the aforementioned means of network optimization. Next to the principal proof of the proposed techniques, the benefits are highlighted in different case studies, while the most representative designs are further discussed

L-Band In-Line Remote Amplification for an Extended WDM/PON Ring Architecture

In this paper, a study on a fully passive WDM/PON ring architecture which reaches 19 km distance, while serving more than 1000 users with symmetric several hundred Mbit/s per user is presented. The design is based on SARDANA (Scalable Advanced Ring -based Passive Dense Access Network Architecture) and was generated as an alternative solution, with its novelty laying on the use of L-band in line remote amplification. The simulation of an extended access WDM/TDM PON formed in a double fibre ring with single fiber trees was created. The network’s operation has been tested for several conditions of usage (i.e. maximum number of users,transmission power and pump power) and an optimization of the design has been performed. The target was to achieve, with given transmission and pump power, the reach of more then 1000 users with input power high enough to permit the use of an RSOA at the ONU. The use of L-band signals and special doped fiber has permitted the effective use of RSOAs in the total of the end users.Peer ReviewedPostprint (published version

Techno-economics of resilient extended FTTH PONs

This work analyses different architectures of protected FTTH passive optical networks in terms of device and infrastructure requirements and costs, considering different home density scenarios and volume projections. The results show that the Sardana hybrid resilient network presents a wider scalability range in terms of cost efficiency.Peer ReviewedPostprint (published version

L-Band In-Line Remote Amplification for an Extended WDM/PON Ring Architecture

In this paper, a study on a fully passive WDM/PON ring architecture which reaches 19 km distance, while serving more than 1000 users with symmetric several hundred Mbit/s per user is presented. The design is based on SARDANA (Scalable Advanced Ring -based Passive Dense Access Network Architecture) and was generated as an alternative solution, with its novelty laying on the use of L-band in line remote amplification. The simulation of an extended access WDM/TDM PON formed in a double fibre ring with single fiber trees was created. The network’s operation has been tested for several conditions of usage (i.e. maximum number of users,transmission power and pump power) and an optimization of the design has been performed. The target was to achieve, with given transmission and pump power, the reach of more then 1000 users with input power high enough to permit the use of an RSOA at the ONU. The use of L-band signals and special doped fiber has permitted the effective use of RSOAs in the total of the end users.Peer Reviewe

Techno-economics of resilient extended FTTH PONs

This work analyses different architectures of protected FTTH passive optical networks in terms of device and infrastructure requirements and costs, considering different home density scenarios and volume projections. The results show that the Sardana hybrid resilient network presents a wider scalability range in terms of cost efficiency.Peer Reviewe

The rhombus matrix Definition and properties

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Experimental evaluation and improvement methods for low cost transmitters in long reach PONs

In this paper, we first analyze the degradation stochastic resonance (DSR) effect in the context of adaptive averaging (AD-AVG) architectures. The AD-AVG is the adaptive version of the well-known AVG architecture . It is an optimized fault-tolerant design for future technologies with very high rates of failures and defects. With system degradation the AD-AVG reliability is diminishing, as expected, but at a certain moment in time it increases due to the DSR occurrence, which is counterintuitive. We study this phenomenon under various redundancy levels and noise condition. If we take for example a 20-input AD-AVG with particular noise conditions, our simulations indicate an initial yield decrease from 1 to 0.89 with the system degradation, then a grow up to 0.94 at the DSR peak, and finally a decrease to zero when the system is reaching its end of life. Subsequently, we introduce a method to induce DSR in an AD-AVG structure, regardless of the degradation level, when this results in reliability improvement. To achieve this, we augment the AD-AVG with per input controllable noise injectors that can be utilized to induce virtual circuit degradation and create the required conditions for the DSR peak appearance. With this scheme the beneficial DSR effect is created even though the actual DSR system degradation (aging conditions) is not reached. This allows us to provide an optimum and nearly flat reliability level at any time before the DSR peak degradation level. Our experiments suggest that when we apply this method to the same 20-input AD-AVG, we obtain a guaranteed yield level of 0.94 from fresh devices to the DSR peak degradation level with a maximum yield of 0.97. In this way, a minimum yield level can be guaranteed, by determining at design time the required AD-AVG redundancy that provides it, for the entire life of the system.Peer Reviewe

Modification of natural rubber by graft copolymerisation of non-ionogenic hydrophilic monomers in latex

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Wavelength-tuneable remote node for enhanced resilience and optimization of WDM access networks

A remote node design with a wavelength tuneable optical add/drop element is presented and experimentally demonstrated for application in a resilient ring+tree access network architecture. The flexibility of the network node regarding its allocation to the wavelength dimension of the network can be exploited to retain service delivery in case of subsystem failure at the optical line terminal (OLT) or optical network unit (ONU) as well as for an optimization of the transmission performance when switching from normal to resilient network operation in case of a ring fibre cut. A loss budget of 30 dB is compatible for the passive optical access network.Peer Reviewe

Study of powder injection and dephosphorization processes for high chromium stainless steels

55.00; Translated from Chinese (Iron Steel (China) 1987 v. 22(4) p. 20-27)SIGLEAvailable from British Library Document Supply Centre- DSC:9022.06(BISI-Trans--26324)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo