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Research on energy consumption and bandwidth allocation is the basis for achieving the standard of service and fairness requirements for various traffic classes within the integrated optical-wireless access networks. The energy consumption issue is increasingly vital nowadays. The access segment of both optical and wireless networks is well-known for its domination over total network power consumption. In this research paper, the full power consumption and energy efficiency of integrated Ethernet Passive Optical Network (EPON) and two wireless technologies, namely Worldwide Interoperability for Microwave Access (WiMAX) and Long-Term Evolution (LTE) with a unique EPON-based semi-dynamic bandwidth allocation (SD-DBA), are evaluated. A semi-analytical power consumption model is proposed and applied within the simulation process for energy performance evaluation. Furthermore, various issues that will affect the energy performance like split ratio, Femtocell Base Station (FBS) range, analysis of broadcast elements, and modulation schemes are considered. The obtained results prove that the EPON-WiMAX with SD-DBA has better energy efficiency compared to EPON-LTE with SD-DBA that offers the best data rates with an increase of 12% in splitting ratio, 3.846% in FBS range and 8.6957% in broadcast factor. [ABSTRACT FROM AUTHOR]

Ethernet Passive Optical Network (EPON) is that technology that can rule out the congestion in local loop at the level of user and local exchange. At present, there are many simulators to analyze the EPON but the simplest one is using MATLAB. In this paper, we have first analyzed the bit rate performance of WDM EPON and verified the result using NS2 software. After that in the presented WDM EPON model, we proposed an algorithm for wavelength and bandwidth allocation with full QoS support. The result indicates that traffic generation in both NS2 and MATLAB follow the same trend and the proposed algorithm optimizes the various throughput parameters. We found that the bit error rate varies from 14-22 Mbps, 14-55 Mbps, and 36-48 Mbps for EF, AF, and BE traffic respectively.

The recent evolution of passive optical network standards and related research activities for physical layer solutions that achieve bit rates well above 10 Gbps per wavelength (λ) is discussed. We show that the advancement toward 50, 100, and 200 Gbps/λ will certainly require a strong introduction of advanced digital signal processing (DSP) technologies for linear, and maybe nonlinear, equalization and for forward error correction. We start by reviewing in detail the current standardization activities in the International Telecommunication Union and the Institute of Electrical and Electronics Engineers, and then we present a comparison of the DSP approaches for traditional direct detection solutions and for future coherent detection approaches. [ABSTRACT FROM AUTHOR]

This paper focusses on Service Level Agreement (SLA) based end-to-end Quality of Service (QoS) maintenance across a wireless optical integrated network. We use long term evolution/5G based spectrum access system (SAS) in the wireless network and the optical network is comprised of an Ethernet Passive Optical Network (EPON). The proposal targets a learning-based intelligent SAS where opportunistic allocation of any available bandwidth is done after meeting the SLA requirements. Such an opportunistic allocation is particularly beneficial for nomadic users with varying QoS requirements. The opportunistic allocation is carried out with the help of Vickrey-Clarke-Groves (VCG) auction. The proposal allows the users of the integrated network to decide the payment they want to make in order to opportunistically avail bandwidth. Learning automata is used for the users to intelligently converge to the optimal payment value based on the network load. The payment made by the users is later used by the optical network units of the EPON to prepare the bids for the auction. The proposal has been verified through extensive simulations. [ABSTRACT FROM AUTHOR]

As a promising technology, Flex Ethernet (FlexE) helps to realize deterministic and ultra-low latency in metro and transport networks. Meanwhile, previous studies have confirmed the advantages of the symbiosis of FlexE and elastic optical network (EON) (i.e., a FlexE-over-EON) on resource utilization and cost-effectiveness. In this paper, we consider the cross-layer restoration (CLR) in FlexE-over-EONs based on the FlexE-aware architecture. Specifically, we address the situation where an outage happened on one FlexE switch in the packet layer to bring it offline temporarily and then the affected client flows need to be recovered quickly and proactively. Three CLR strategies are first proposed to fully explore the flexibility of FlexE-over-EON for restoring the affected flows. Then, with the strategies, we formulate an integer linear programming (ILP) model and design an auxiliary graph (AG) based algorithm to reroute the affected flows as well as minimize the additional operational expense (OPEX) incurred during the CLR. Extensive simulations verify the effectiveness of our proposed CLR algorithms. [ABSTRACT FROM AUTHOR]

Integration of Ethernet passive optical network and WiMAX technologies is viewed as a great solution for next-generation broadband access networks. In the systems adopting this strategy, weighty bandwidth allocation schemes are fundamental to fulfill the quality of service and fairness requirements of different traffic classes. Existing proposals to overcome the bandwidth allocation problem in EPON/WiMAX networks dismiss collaboration between the self-interested EPON and WiMAX service providers. This study presents a novel EPON-based semi-dynamic bandwidth allocation algorithm to allow the integration process. In the proposed algorithm depending on the auction process, the optical line terminal runs an auction to adequately post the optical network unit bandwidth that distributes the most elevated bidders based on the measurement of the accessible bandwidth. Simulation results demonstrate massive upgrades compared with fair sharing using dual-service-level agreements, limited-service interleaved polling with adaptive cycle time methods, bandwidth allocation strategy using Stackelberg game, and bandwidth allocation strategy using coalition game regarding the quality of service parameters such as throughput and time delay. This will be extremely helpful for optical system upgrading and improvement with minimal effort. [ABSTRACT FROM AUTHOR]

In Ethernet Passive Optical Network, with Load Adaptive Polling Sequence Arrangement (LASA) method, the Optical Line Terminal assigns delayed polling sequence arrangement for a set of Optical Network Units (ONUs) over the cycles. This arrangement has resulted in identical cycle time with Constant Bit Rate traffic. In addition, the LASA through its arrangement provides sleep mode to different set of ONUs over the cycles and provides maximum sleep time for ONUs. With these advantages of LASA and keeping the scenario with different cycle times for the ONUs, in this work, the Variable Bit Rate (VBR) based LASA method is analyzed. The variation in the cycle times has resulted in two cases and in each case by varying the maximum (Mxi) and the minimum (Mni) idle times, a maximum of 40.6% reduction in power consumption is observed in LASA with VBR scheduling method than traditional one. [ABSTRACT FROM AUTHOR]

Ethernet Passive Optical Network (EPON) is that technology that can rule out the congestion in local loop at the level of user and local exchange. At present, there are many simulators to analyze the EPON but the simplest one is using MATLAB. In this paper, we have first analyzed the bit rate performance of WDM EPON and verified the result using NS2 software. After that in the presented WDM EPON model, we proposed an algorithm for wavelength and bandwidth allocation with full QoS support. The result indicates that traffic generation in both NS2 and MATLAB follow the same trend and the proposed algorithm optimizes the various throughput parameters. We found that the bit error rate varies from 14-22 Mbps, 14-55 Mbps, and 36-48 Mbps for EF, AF, and BE traffic respectively. [ABSTRACT FROM AUTHOR]

An Ethernet passive optical network (EPON) is an optical access network that allows a higher data rate with low power consumption. To improve energy savings for an EPON, the sleep and doze modes for the optical network units (ONUs) play a pivotal role. Many prediction schemes have been proposed to control these modes. To increase the prediction accuracy, this study proposes an energy-efficient approach that uses a support vector regression (SVR) model. A dynamic bandwidth allocation (DBA) scheme called SVR-DBA is designed to allocate bandwidth to ONUs more efficiently and fairly. To determine the effectiveness of the proposed scheme, simulations are performed. The simulation results show that the proposed scheme decreases energy consumption for ONUs by up to 47% and fulfills the quality-of-service (QoS) requirements in terms of delay, jitter, and packet loss. [ABSTRACT FROM AUTHOR]

Fiber Wireless (Fi-Wi) access innovation is one of the current advances to satisfy clients' current requests in a cost-proficient manner. What's more, on the other hand, WSN-based on Precision Agriculture (PA) is likely to be a significant innovation in meeting food production needs. The utilization of Fi-WSN in PA can better control agricultural information flow from WSN to the central office (CO). A great deal of utilizations of WSN in PA are crop checking, boundary observing, and irrigation water system frameworks. The study was conducted on an automated irrigation system for farmers in 2020 at NFC Faisalabad, Pakistan. This actualized the WSN-based irrigation water system framework in Fi-WSN with high and low need information gathered through sensors. The basic purpose of this research was to overcome the delay factor of high demand information in Fi-WSN with the Class-of-Service (CoS) priority queue's gateway design that leads to increase the farming traffic performance. The planned passage for farming traffic in Fi-WSN furnished low-delay values with two CoS queues rather than a single CoS queue. The results showed that the proposed gateway with two CoS lines greatly reduces the start-to-end delay of high and low-demand information and improved the network performance 40% to 60% depending on traffic load. [ABSTRACT FROM AUTHOR]

The scattered Optical Network Units (ONUs) in an optical access network have different propagation delays. In an Ethernet passive optical network (EPON) adopting the traditional Interleaved Polling with Adaptive Cycle Time (IPACT) scheme, such ONU propagation delay difference will waste network resources and will degrade both network delay performance and network energy efficiency in delivering low-latency services. In this article, to deal with the heterogeneous ONU propagation delays problem, two solutions are proposed and investigated. The first solution, namely the Upstream Postponing with ONU Dozing (UP-OD) scheme, is to properly postpone the upstream transmissions of those ONUs having relatively short propagation delays to improve channel utilization efficiency, and ONU doze mode is incorporated to enhance network energy efficiency. The second solution, namely the Identical Fiber Length with ONU Sleeping (IFL-OS) scheme, is to adopt an identical distribution fiber length for ONUs to enhance channel utilization, and ONU sleep mode is incorporated for energy consumption reduction. Simulation results show that both the UP-OD scheme and the IFL-OS scheme reduce network delay and improve network energy efficiency in delivering low-latency (

The most important challenge in an Ethernet Passive Optical Network (EPON) is bandwidth allocation. This is because it is a mandatory service to satisfy the end users' service level agreement (SLA). Dynamic allocation of bandwidth on the diversified characteristics of services such as high definition video, audio cloud computing resource sharing, and virtual reality games is required, especially in point-to-point and multipoint-to-point architectures. Hence, we propose an integrated Unified Dynamic Bandwidth Allocation Scheme (UDBAS) framework for wired and wireless network devices. Our proposed UDBAS framework can provide superior execution of the process of bandwidth partitioning with regard to the acceptance probability and bandwidth utilization, particularly when short-term variations in bandwidth requirements occur. More specifically, owing to the requirement of bandwidth at each customer premises, the present scheme is not efficient for scheduling bandwidth management. Therefore, in this paper, we introduce a UDBAS scheme that is based on the predictive user's bandwidth requirement and regulates bandwidth resources. We show both analytically and by simulation that the proposed scheme can be efficiently applied to an EPON network.

The post-embedding immunogold (PI) technique for immunolabeling of neuronal tissues utilizing standard thin-section transmission electron microscopy (TEM) continues to be a prime method for understanding the functional localization of key proteins in neuronal function. Its main advantages over other immunolabeling methods for thin-section TEM are (1) fairly accurate and quantifiable localization of proteins in cells; (2) double-labeling of sections using two gold particle sizes; and (3) the ability to perform multiple labeling for different proteins by using adjacent sections. Here we first review in detail a common method for PI of neuronal tissues. This method has two major parts. First, we describe the freeze-substitution embedding method: cryoprotected tissue is frozen in liquid propane via plunge-freezing, and is placed in a freeze-substitution instrument in which the tissue is embedded in Lowicryl at low temperatures. We highlight important aspects of freeze-substitution embedding. Then we outline how thin sections of embedded tissue on grids are labeled with a primary antibody and a secondary gold particle-conjugated antibody, and the particular problems encountered in TEM of PI-labeled sections. In the Discussion, we compare our method both to earlier PI methods and to more recent PI methods used by other laboratories. We also compare TEM immunolabeling using PI vs. various pre-embedding immunolabeling methods, especially relating to neuronal tissue. [ABSTRACT FROM AUTHOR]

Next-generation Ethernet passive optical networks (NG-EPONs) were standardized by the IEEE 802.3 Working Group in 2020 [IEEE 802.3ca-2020–IEEE Standard for Ethernet Amendment 9: physical layer specifications and management parameters for 25 Gb/s and 50 Gb/s passive optical networks, 2020]. Due to the channel bonding technology ["Recent progress on 25G EPON and beyond," in 42nd European Conference on Optical Communication (ECOC) (2016).] adopted by NG-EPONs, multiple wavelengths can be assigned to an optical network unit (ONU) simultaneously, leading to higher peak transmission rates. As a result, assigning traffic in multiple wavelength channels provides greater scheduling flexibility, a higher peak upstream rate, and better upstream transmission performance (i.e., lower latency); however, it leads to the use of high-cost ONUs with multiple transceivers and further increases the total cost of NG-EPONs. Therefore, selecting a proper wavelength deployment scheme is very important when designing future NG-EPONs. In this paper, we focus on the trade-off between ONU cost and the upstream performance in a static scenario, and we develop an integer linear programming model to formulate the problem. In addition, we propose a heuristic wavelength deployment scheme comparison and selection (WDSCS) algorithm to effectively select appropriate wavelength deployment schemes. According to our simulation results, our proposed WDSCS algorithm can efficiently find a finer number of deployment wavelengths to balance the cost of ONUs and the upstream transmission performance. The wavelength deployment schemes for future NG-EPONs can also be specified based on whether network operators prioritize network performance or cost. [ABSTRACT FROM AUTHOR]

This article proposes a novel architecture of a time division multiplexing passive optical network (TDM-PON) system with general-purpose hardware. The system operates with the point-to-point (P2P) Ethernet protocol and software processing. The architecture is redesigned from the ground up, differing from conventional PON system architectures. In recent years, researchers have attempted to softwarize a number of PON functions such as media access control (MAC) and physical functions, which run on a general-purpose central processing unit (CPU). On the other hand, these existing systems still required PON-dedicated or programmable hardware for processing the PON specific protocol. This paper proposes a TDM-PON system that requires only general-purpose hardware; a network interface card with the use of the P2P Ethernet protocol and a general-purpose server with the use of software processing. To operate the proposed system, we newly developed burst-mode operation and multipoint MAC control schemes, while taking Link Fault Signaling and CPU processing jitter into account. We quantitatively evaluated the burst-mode transmission with P2P generic Ethernet TRx as a preliminary experiment, which showed that Ton and Toff were 75 μs and less than 1 μs, respectively. Then, we measured our developed prototype system's performance for verifying the feasibility of our proposal. In specific, it achieved a 5.2 Gbps PON system consisting of an optical line terminal (OLT) server and two optical network unit (ONU) servers under the condition of a 500-ms grant cycle including a 100-ms discovery window. [ABSTRACT FROM AUTHOR]

An Ethernet passive optical network (EPON) is an optical access network that allows a higher data rate with low power consumption. To improve energy savings for an EPON, the sleep and doze modes for the optical network units (ONUs) play a pivotal role. Many prediction schemes have been proposed to control these modes. To increase the prediction accuracy, this study proposes an energy-efficient approach that uses a support vector regression (SVR) model. A dynamic bandwidth allocation (DBA) scheme called SVR-DBA is designed to allocate bandwidth to ONUs more efficiently and fairly. To determine the effectiveness of the proposed scheme, simulations are performed. The simulation results show that the proposed scheme decreases energy consumption for ONUs by up to 47% and fulfills the quality-of-service (QoS) requirements in terms of delay, jitter, and packet loss.

A new framework for Ethernet Passive Optical Network (EPON) is proposed wherein the Dynamic Bandwidth Allocation (DBA) estimation is shared by the Optical Line Terminal (OLT) and Optical Network Units (ONU) thereby reducing the load on the OLT and reducing the delay and improving the bandwidth utilization. The proposed framework was evaluated under heavy load conditions and with the help of OPNET simulations it has been demonstrated that our framework outperforms the conventional scheme in terms of throughput, percentage of utilization and other QoS services. However, in order to employ the algorithm for commercial purpose, the performance of the algorithm should be evaluated in a WiMAX switch to verify its hardware compatibility. This paper focuses on implementing and testing the performance of the DDA-EPON (Distributed DBA) algorithm in a WiMAX switch using the Intel's IXP 2400 Network Processor. The performance of the algorithm is further compared with the conventional process in terms of machine clock cycles before arriving at conclusions. Copyright © 2020 Praise Worthy Prize S.r.l. - All rights reserved. [ABSTRACT FROM AUTHOR]

In order to meet the requirements of services and applications envisioned for post-5G and 6G networks, research efforts are heading towards the convergence of architectures aiming to support the wide variety of new compute-demanding and latency-sensitive applications in the context of Tactile Internet. In this article, we study the resource allocation and association of users with different delay requirements in a shared-backhaul fiber-wireless (FiWi) enhanced Heterogeneous Cloud Radio Access Network (h-cran) with Multi-access Edge Computing (mec) and offloading. As opposed to traditional resource and association management, we propose a decentralized algorithm based on a full dual decomposition of the optimization problem to operate the network. Results show that this approach outperforms the traditional one in terms of average delay and energy consumption, achieving up to 80% average delay improvement in high-load scenarios. [ABSTRACT FROM AUTHOR]

In time division, multiple access (TDMA)-based passive optical network (PONs), a dynamic bandwidth assignment (DBA) is necessary for efficient utilization of the available bandwidth of the upstream link. An efficient DBA scheme can improve the upstream performance of a traffic class of an ONU in two ways. First, it can increase the bandwidth assignment to it by efficiently utilizing the available bandwidth. Secondly, it can reduce the channel and frame idle time by increasing the polling frequency and by assigning extra surplus bandwidth not used by the other ONUs. Many DBA schemes have been reported for both ITU PONs (GPON and XGPON) and IEEE PONs (EPON and 10 G EPON). In this study, we explain the impact of DBA scheme on the upstream performance of PON and then do a thorough survey of both PON standards, categorize the DBA schemes and review them critically. Based on the literature review we also give our opinion on the most suitable DBA scheme for both type PONs on the basis of upstream delays, frame loss and bandwidth utilization efficiency. [ABSTRACT FROM AUTHOR]

Geometrically shaped (GS) 8-, 16, and 32-ary modulation formats are investigated for use in coherent passive optical networks. The modulation formats are designed to improve receiver sensitivity when paired with a binary, soft-decision forward error correction code (SD-FEC), such as a low density parity check (LDPC). Herein we consider the LDPC code specified in the draft 50G EPON standard, and show how this type of code can be particularly advantageous in a coherent transmission system. A receiver sensitivity of $-$ 26.7 dBm is achieved at a post-FEC bit error rate below 3.8 $\times 10^{-6}$ for a polarization-scrambled 32-ary GS modulation format at 25 GBd, received using a single-polarization, phase-diverse coherent receiver. This yielded a bit rate of 100 Gbit/s, net of coding and pilot overhead. This modulation format was shown to perform equally well in transmission, with no observed dispersion penalty after 80 km standard single mode fiber. Finally, this modulation format was received, at a reduced data rate of 50 Gbit/s, using a heterodyne coherent receiver based on a single balanced photodiode. The receiver sensitivity for this simplified receiver configuration was $-$ 28.5 dBm, yielding a power budget of 34.2 dB. [ABSTRACT FROM AUTHOR]

In light of the 5G deployments, edge computing, and future high bandwidth services, the industry is rethinking the optical access network architecture design. Passive optical network (PON) with its efficient fiber infrastructure plays an essential role in this design transformation. This article reviews the driving forces shaping the new generations of PON systems in the coming years; and discusses the course of action in the FSAN Group, ITU-T, and IEEE standards bodies to address the impending requirements. [ABSTRACT FROM AUTHOR]

Broadband telecommunication networks are the future of communication and distribution of multimedia services. Thanks to the high transmission potential and capacity of optical fibres, the optical networks are predestined to be more widely used in telecommunications considering the higher data rates through Triple Play services. This paper describes the impact of selected quality parameters on multimedia services defined as Triple Play within an optical network based on the EPON standard. The Triple Play services are then evaluated with measuring instruments and software applications according to QoS requirements and using evaluation methods based on generally defined standards. These are mainly subjective (listening and conversational) and objective (MSE, PSNR, SSIM) methods, or parameters (MOS) and factors (bitrate, delay, packet loss rate, jitter, BER) that are defined for the respective service. The values measured during the experimental tests were related to the limiting parameters of optical topology based on EPON networks for individual services according to their QoS requirements and objective user evaluation.

BACKGROUND: Doxorubicin is a cytostatic drug from the group of anthracycline antibiotics that is widely used as a chemotherapeutic agent. Side effects of the active substance include cardiotoxicity and nephrotoxicity. Doxorubicin-treated renal epithelial cells and (sarcoma) tumors are examined by correlative light and electron microscopy (CLEM) to investigate the subcellular localization of doxorubicin. METHODS: The kidney epithelial cell line MDCK II (Madin-Darby Canine Kidney) grown on culture dishes were treated with doxorubicin. Subsequently, the cells are analyzed by means of fluorescence and transmission electron microscopy (TEM). In vivo, alveolar rhabdomyosarcoma (RH 30) tumor cells are transferred to the chorioallantoic membrane (CAM) of the chicken embryo. Doxorubicin is injected into a vein of the chicken embryo. After 24 hours, the tumor is removed and examined using CLEM. RESULTS: The kidney epithelial cells and the doxorubicin-injected tumors show a clear staining of the cell nucleus, which correlates with electron-dense regions (heterochromatin). High-resolution TEM shows that doxorubicin treatment leads to an enormous stress situation with an increased formation of membrane blebbings. CONCLUSIONS: CLEM is a promising new method to visualize the pattern of fluorescing drugs (e.g. doxorubicin) in renal epithelial cells and tumors, and to localize the drug in its subcellular context combined with high resolution. [ABSTRACT FROM AUTHOR]

The limited scheme with excess distribution (LS-ED), being a superior grant-sizing protocol in terms of average delay minimization while providing fairness and quality of service (QoS) satisfaction in Ethernet passive optical networks (EPONs), has already been deployed in diverse technologies. An analysis of the protocol is of paramount importance for obtaining deeper insight into several network design and deployment aspects. Thus, the primary objective of this paper is to perform a rigorous mathematical analysis of LS-ED, for the first time to the best of our knowledge, with the help of a discrete time Markov chain (DTMC). Owing to the dependency of the grant size of a particular optical network unit (ONU) on the queue length of other ONUs, the exact queuing analysis of this scheme necessitates solving a Markov model of the same dimension as the number of ONUs, which makes the analysis complicated and mathematically intractable. A lower-dimensional valid approximation model may allow us to perform such an analysis. In this paper, for the first time to the best of our knowledge, we present an analysis of the scheme, wherein the system dynamics are captured from the perspective of the scheduler leading to an approximate model. The model aids in obtaining a closed-form expression for the average cycle time and throughput along with closed-form expressions for average buffer occupancy and average delay at low load. Finally, we provide useful design insights for EPONs employing LS-ED. [ABSTRACT FROM AUTHOR]

Starting from the research of RFoG optical network technology and combining with the development of PON network, this paper puts forward a kind of integrated optical network structure, which can multiply the access bandwidth; furthermore, it analyzes the key technologies such as optical devices and integrated terminal equipment, and provides a technical scheme for upgrading the network. [ABSTRACT FROM AUTHOR]

Industrial Ethernet is a technology widely spread in factory floors and critical infrastructures where a high amount of data need to be collected and transported. Fiber optic networks at gigabit rates fit well with that type of environment, where speed, system performance, and reliability are critical. In this paper, a new encryption method for high-speed optical communications suitable for such kinds of networks is proposed. This new encryption method consists of a symmetric streaming encryption of the 8b/10b data flow at physical coding sublayer level. It is carried out thanks to a format preserving encryption block cipher working in CTR (counter) mode. The overall system has been simulated and implemented in a field programmable gate array. Thanks to experimental results, it can be concluded that it is possible to cipher traffic at this physical level in a secure way. In addition, no overhead is introduced during encryption, getting minimum latency and maximum throughput. [ABSTRACT FROM AUTHOR]

The IEEE 802.3ca task force is studying the next generation Ethernet passive optical network (NG-EPON), which introduces channel bonding to enable optical network units (ONUs) to bundle multiple wavelength channels to achieve higher peak rates. In order to register these multi-channel ONUs, the optical line terminal (OLT) needs to acquire ONUs' device information, assign working parameters, and verify the connectivity of each channel. Traditional ONU registration protocol, designed for singlechannel ONUs, is not suitable for multi-channel ONUs because it cannot guarantee the channel connectivities of all channels. Therefore, it is essential to extend the traditional registration protocol or design a new registration protocol for NG-EPON multi-channel ONUs. In this paper, we first extend the traditional registration protocol directly to satisfy the requirements of registering multi-channel ONUs. Besides, we propose a novel registration protocol based on the coordination of channel terminals. In order to compare the performances of two registration protocols, we model their registration processes, analyze their registration delays, and find their corresponding influence factors. Simulation results show that our proposed registration protocol has a smaller registration delay as well as better horizontal scalability. [ABSTRACT FROM AUTHOR]

Managing large data volumes requires high-capacity networks due to increasing internet users and bandwidth-intensive applications. Optical fiber, particularly Ethernet passive optical network (EPON), is vital for cost-efficient last-mile connectivity. EPON handles data traffic, while WiMAX demands extensive bandwidth due to rising mobile users. Both the networks experience bursty user-generated traffic with fluctuating bandwidth needs. That's why, the bandwidth requirements of each subscriber fluctuates dynamically. Moreover, access networks must provide distinct service quality to support a large number of users and ensure the requirement of 5G and beyond (5 GB) communication standards. To address these difficulties, in this paper, we propose a prediction-based hybrid dynamic bandwidth allocation (PHDBA) algorithm for EPON-WiMAX converge network. Due to the increasing value of trustworthy network service access, we have implemented a statistical modeling technique. Our technique predicts the heavily loaded ONUs from a randomly generated dataset and provides an approximation of the amount of data that can be strongly loaded. To make this prediction, we have proposed a statistical modeling technique and updated the auction-based semi dynamic bandwidth allocation (SDBA) algorithm. To validate our proposed algorithm, computer simulation is used to evaluate different performance parameters in terms of end-to-end delay, jitter, throughput, and fairness. From the comparative analyses, it is proved that our proposed scheme surpasses the competition over the existing SDBA algorithm. [ABSTRACT FROM AUTHOR]

This article presents a numerical implementation of the activation process for gigabit and 10 gigabit next generation and Ethernet passive optical networks. The specifications are completely different because GPON, XG-PON and NG-PON2 were developed by the International Telecommunication Union, whereas Ethernet PON was developed by the Institute of Electrical and Electronics Engineers. The speed of an activation process is the most important in a blackout scenario because end optical units have a timer after expiration transmission parameters are discarded. Proper implementation of an activation process is crucial for eliminating inadvisable delay. An OLT chassis is dedicated to several GPON (or other standard) cards. Each card has up to eight or 16 GPON ports. Furthermore, one GPON port can operate with up to 64/128 ONUs. Our results indicate a shorter duration activation process (due to a shorter frame duration) in Ethernet-based PON, but the maximum split ratio is only 1:32 instead of up to 1:64/128 for gigabit PON and newer standards. An optimization improves the reduction time for the GPON activation process with current PLOAM messages and with no changes in the transmission convergence layer. We reduced the activation time from 215 ms to 145 ms for 64 ONUs. [ABSTRACT FROM AUTHOR]

Energy and power are key challenges in high-performance computing. System energy efficiency must be significantly improved, and this requires greater efficiency in all subcomponents. An important target of optimization is the interconnect, since network links are always on, consuming power even during idle periods. A large number of HPC machines have a primary interconnect based on Ethernet (about 40 percent of TOP500 machines), which, since 2010, has included support for saving power via Energy Efficient Ethernet (EEE). Nevertheless, it is unlikely that HPC interconnects would use these energy saving modes unless the performance overhead is known and small. This paper presents PerfBound, a self-contained technique to manage on/off-based networks such as EEE, minimizing interconnect link energy consumption subject to a bound on the performance degradation. PerfBound does not require changes to the applications and it uses only local information already available at switches and NICs without introducing additional communication messages, and is also compatible with multi-hop networks. PerfBound is evaluated using traces from a production supercomputer. For twelve out of fourteen applications, PerfBound has high energy savings, up to 70 percent for only 1 percent performance degradation. This paper also presents DynamicFastwake, which extends PerfBound to exploit multiple low-power states. DynamicFastwake achieves an energy–delay product 10 percent lower than the original PerfBound technique. [ABSTRACT FROM AUTHOR]

Emerging modular cable network architectures distribute some cable headend functions to remote nodes that are located close to the broadcast cable links reaching the cable modems (CMs) in the subscriber homes and businesses. In the remote-PHY (R-PHY) architecture, an R-PHY device conducts the physical layer processing for the analog cable transmissions, while the headend runs the data over cable service interface specification (DOCSIS) medium access control (MAC) for the upstream transmissions of the distributed CMs over the shared cable link. In contrast, in the remote MACPHY (R-MACPHY) architecture, an R-MACPHY device (RMD) conducts both the physical and MAC layer processing. In this paper, we conduct a comprehensive performance comparison of the R-PHY and R-MACPHY architectures. We first develop analytical delay models for the polling-based MAC with gated bandwidth allocation of Poisson traffic in the R-PHY and R-MACPHY architectures. We then conduct extensive simulations to assess the accuracy of the analytical model and to evaluate the delay-throughput performance of the R-PHY and R-MACPHY architectures for a wide range of deployment and operating scenarios. Our evaluations include long converged interconnect network (CIN) distances between remote nodes and headend, bursty self-similar traffic, and double-phase polling to mask long CIN propagation distances. We find that for long CIN distances above 100 miles, the R-MACPHY architecture achieves significantly shorter mean upstream packet delays than the R-PHY architecture, especially for bursty traffic. Our extensive comparative R-PHY and R-MACPHY evaluation can serve as a basis for the planning of modular broadcast cable based access networks. [ABSTRACT FROM PUBLISHER]

This paper presents an energy efficient Power over Ethernet interface for applications that require higher power delivery than that of IEEE 802.3af and 802.3at standards allow. The proposed architecture increases the power delivered to the powered-device by utilizing all four pairs of the CAT5 cable. Maximum power is guaranteed by a current-balancing control block which equalizes the currents in the CAT5 cable. The current-balancing control is implemented in an efficient way of regulating the pass p-type metal-oxide-semiconductor transistor in the diode bridge stage. The proposed interface also includes a hot-swapping control block that protects the devices in the power conduction path by limiting both the maximum load current and the maximum voltage ramping rate. The voltage and current-limiting functions are controlled by two separated regulation loops. To reduce the power loss, a single pass n-type metal-oxide-semiconductor transistor is inserted in the ground current path and is shared by both regulation loops. The experimental result of the assembled prototype showed balanced currents among all four pairs in the CAT5 cable. In cases of hot-plugging, the proposed prototype exhibited both well-controlled inrush current and limited voltage-ramping rate under various load capacitance conditions. [ABSTRACT FROM PUBLISHER]

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The infrastructure to develop the next generation optical access network is the Ethernet passive optical network (EPON). Interleaved polling with adaptive cycle time (IPACT) is a common polling method of an EPON. However, the mean waiting time of packets (= the mean packet delay) with IPACT is large depending on the arriving time of the packets. In this paper, a novel media access method for IPACT is proposed in order to minimize the mean packet delay. The mean packet delay with the proposed method is also derived as the exact solution. This solution is based on the non-trivial simplification of the previous work on the analytical solution for general IPACT. We confirm a close match between simulation and our theoretical results and show the effectiveness of our method. [ABSTRACT FROM PUBLISHER]

Bandwidth requirements of both wireless and wired clients in access networks continue to increase rapidly, primarily due to the growth of video traffic. Application awareness can be utilized in access networks to optimize quality of experience (QoE) of end clients. In this study, we utilize information at the client-side application (e.g., video resolution) to achieve superior resource allocation that improves user QoE. We emphasize optimizing QoE of the system rather than quality of service (QoS), as user satisfaction directly relies on QoE and optimizing QoS does not necessarily optimize QoE, as shown in this study. We propose application-aware resource-allocation schemes on an Ethernet passive optical network (EPON), which supports wireless (utilizing orthogonal frequency division multiple access) and wired clients running video-conference applications. Numerical results show that the application-aware resource-allocation schemes improve QoE for video-conference applications for wired and wireless clients. [ABSTRACT FROM PUBLISHER]