Hybrid Fiber Coax Research Articles

Topology reconstruction using time series data in telecommunication networks

AbstractWe consider Hybrid fiber‐coaxial (HFC) networks in which data is transmitted from a root node to a set of customers using a series of splitters and coaxial cable lines that make up a tree. The physical locations of the components in a HFC network are always known but frequently the cabling is not. This makes cable faults difficult to locate and resolve. In this study we consider time series data received by customer modems to reconstruct the topology of HFC networks. We assume that the data can be translated into a series of events, and that two customers sharing many connections in the network will observe many similar events. This approach allows us to use maximum parsimony to minimize the total number of character‐state changes in a tree based on observations in the leaf nodes. Furthermore, we assume that nodes located physically close to each other have a larger probability of being closely connected. Hence, our objective is a weighted sum of data distance and physical distance. A variable‐neighborhood search heuristic is presented for minimizing the combined distance. Furthermore, three greedy heuristics are proposed for finding an initial solution. Computational results are reported for both real‐life and synthetic network topologies using simulated customer data with various degrees of random background noise. We are able to reconstruct large topologies with a very high precision.

Big-Data Platform for Performance Monitoring of Telecom-Service-Provider Networks

Large telecom-service-provider networks are typically based on complex communications infrastructures comprising millions of network devices. The performance monitoring of such networks is a very demanding and challenging task. A large amount of data is collected and processed during performance monitoring to obtain information that gives insights into the current network performance. Using the obtained information, providers can efficiently detect, locate, and troubleshoot weak spots in the network and improve the overall network performance. Furthermore, the extracted information can be used for planning future network expansions and to support the determination of business-strategy decisions. However, traditional methods for processing and storing data are not applicable because of the enormous amount of collected data. Thus, big-data technologies must be used. In this paper, a big-data platform for the performance monitoring of telecom-service-provider networks is proposed. The proposed platform is capable of collecting, storing, and processing data from millions of devices. Typical challenges and problems in the development and deployment process of the platform, as well as the solutions to overcome them, are presented. The proposed platform is adjusted to HFC (Hybrid Fiber-Coaxial) network and currently operates in the real HFC network, comprising millions of users and devices.

Impact of the HFC migration to FTTH on the efficiency and reliability of the internet provider services business (A case Study)

This paper presents the impact on the efficiency, reliability, and quality of the Internet provider services due to the migration of the Hybrid Fiber Coaxial (HFC) to the Fiber To The Home (FTTH) infrastructure. The implementation of the emerging technology on communication caused an increase in the internet service provider business competition and it makes the company that engaged in this field will compete to provide the best service to the customers as especially on the efficiency and reliability of the services to whom using the FTTH. The comparison and analysis of the impact of the HFC stand-alone to the FTTH technology migration process on both of the customers sides as well as the Network Availability and the percentage of uptime (connection to the ISP’s) of customer devices are provided. In this case study, it is found that the infrastructure cost of the technology HFC system is cheaper about 53.93 percent than the technology FTTH system. However, from a reliability perspective, FTTH is much better than HFC. It is found that the impact of the migration from HFC to FTTH shows the yearly Network Availability was 98.635 percent with a downtime of 2,819,473 minutes. And it provides an increase of Network Availability after construction (during commissioning or acceptance test). In addition, it was found that the correlation between uptime/downtime before migrating during employed the HFC technology, there were many problems caused by power supply problems and high losses of the coaxial cable. So if the coaxial cable is replaced by the fiber optic cable, will be there is an increase in the availability of the Network Availability during 2020 by 1.301 percent. Also by takeout the FDT on the FTTH, it is predicted that the cost reduction about 10 percent, faster implementation for the schedule and fewer cables maintain.

Detection and Localization of Failures in Hybrid Fiber–Coaxial Network Using Big Data Platform

Modern HFC (Hybrid Fiber–Coaxial) networks comprise millions of users. It is of great importance for HFC network operators to provide high network access availability to their users. This requirement is becoming even more important given the increasing trend of remote working. Therefore, network failures need to be detected and localized as soon as possible. This is not an easy task given that there is a large number of devices in typical HFC networks. However, the large number of devices also enable HFC network operators to collect enormous amounts of data that can be used for various purposes. Thus, there is also a trend of introducing big data technologies in HFC networks to be able to efficiently cope with the huge amounts of data. In this paper, we propose a novel mechanism for efficient failure detection and localization in HFC networks using a big data platform. The proposed mechanism utilizes the already present big data platform and collected data to add one more feature to big data platform—efficient failure detection and localization. The proposed mechanism has been successfully deployed in a real HFC network that serves more than one million users.

RoIP Compression Method in Burst Noise Upstream Environment for CATV Network

A hybrid fiber coaxial (HFC) network uses both optical fibers and coaxial cables for cable TV networks. Coaxial cables are mainly used for access networks. Recently, fiber to the home (FTTH) is being widely deployed. For cable TV companies to utilize readily deployed FTTH, legacy coax network-based customer premise equipment (CPE) such as cable modems and set top boxes may have to be replaced with fiber network based CPE. In order to reduce the expenditure incurred in this process, radio over Internet Protocol (RoIP) technology has been proposed. In the RoIP system, RF signal for coax generated by legacy CPE toward the headend is first sampled, and digitized, and then encapsulated in IP packets, which are then sent to the headend using FTTH access technologies such as passive optical network (PON). In the process of digitizing RF signal, a huge amount of data much more than the base band data is generated. So, a data compression method is required to lower the upstream bit rate maintaining the signal quality. Most compression methods are significantly degraded due to the interference caused by burst noise in the upstream link. Therefore, this paper proposes a new compression method which combines linear predictive coding (LPC), block scaling and non-linear quantization for CATV upstream links. The proposed method is demonstrated to greatly reduce the impact of burst noise while maintaining the compression performance.

A closer look at Deep-fibre FTTdp

In this paper we outline a number of matters that have been raised in relation to Deep-fibre Fibre-to-the-Distribution-Point (FTTdp), and address practical ways that FTTdp can be expected to deliver a maximum overall cost-benefit outcome for the Australian NBN. We present brief discussions of some HFC (Hybrid Fibre Coax) and FTTN (Fibre-to-the-Node) issues considered of concern, to place FTTdp in perspective. We touch briefly on the threat from wireless communications to the fixed line technologies. We discuss the FTTdp equipment ecosystem, migration from legacy services to FTTN or FTTdp, in-building copper concerns, and LFN architecture savings emerging from the FTTdp approach. As previously, we conclude that FTTdp must be honestly evaluated if the nation is to achieve a maximal NBN capability outcome.

A Comprehensive Study of DSCP Markings’ Impact on VOIP QoS in HFC Networks

Various factors can have a significant degrading impact on the residential Voice over Internet Protocol (VoIP) phone services’ quality. Hybrid fibre- coaxial (HFC) networks typically carry three types of traffic that include voice, data, and video. Unlike data and video, some delays or packet loss can result in a noticeable degraded impact on a VoIP’s phone conversation. This paper will analyze and assess VoIP traffic prioritization and its impact on VoIP’s quality of service (QoS) based on the concept of differentiated services code point (DSCP) markings. Call testing examines two types of calls. The first set of tests focus on calls that originate from a VoIP network and terminate on a signalling system 7 (SS7) network. The second experiment focuses on calls that originate from SS7 network and terminate on a VoIP network. The research results provide DSCP markings configurations that can improve phone conversations’ quality.

Getting some reality into debates about NBN FTTP

Sentiment about fibre-to-the-premises (FTTP) runs hot in Australia, fuelled by the NBN initiative for Australia's next generation of broadband. Unfortunately most of the debate is ill-informed, focusing on plumbing rather than the uses to which the network may be put. The base of users subscribing to the higher speeds made possible by FTTP is limited right now, and much of their communication will be speed-limited by constraints outside of the NBN FTTP segment. In addition, a growing proportion of Australians choose to operate entirely on mobile connections. For all these reasons, the number of users who would benefit from FTTP in the short term is modest.
 The Coalition has proposed greater use of existing infrastructure – in particular, using fibre-to-the-node (FTTN)/DSL technology and potentially hybrid-fibre-coax (HFC) technology – to deliver an upgrade earlier and at lower cost. In the face of cost pressures, it is likely that the original 93% FTTP target would be adjusted with greater use of wireless and satellite technologies in rural areas and the use of copper for the final link in multi-dwelling complexes. More generally, there is no question that FTTN/DSL solutions can deliver good quality broadband, but further work will be needed to determine where this can be done cost-effectively. Similarly, with appropriate upgrades, HFC networks can deliver next-generation broadband speeds. When practical factors are taken into consideration, the gap between Labor and Coalition plans closes somewhat.
 Developing the best strategy for Australia needs to take cost into consideration, and there is scope for NBN Co to improve its performance in this area. Any major cost blowout would have significant ramifications for broadband users and use in Australia. If the rollout of FTTP is scaled back, users with a need may still get access on a user-pays principle – though the practicality of this has yet to be demonstrated. Widespread FTTP remains the right long-term goal for Australia, but the approach for getting there needs to be finessed.

A Comprehensive Study of Dscp Markings’ Impact on Voip Qos in Hfc Networks

Various factors can have a significant degrading impact on the residential Voice over Internet Protocol (VoIP) phone services’ quality. Hybrid fibre- coaxial (HFC) networks typically carry three types of traffic that include voice, data, and video. Unlike data and video, some delays or packet loss can result in a noticeable degraded impact on a VoIP’s phone conversation. This paper will analyze and assess VoIP traffic prioritization and its impact on VoIP’s quality of service (QoS) based on the concept of differentiated services code point (DSCP) markings. Call testing examines two types of calls. The first set of tests focus on calls that originate from a VoIP network and terminate on a signalling system 7 (SS7) network. The second experiment focuses on calls that originate from SS7 network and terminate on a VoIP network. The research results provide DSCP markings configurations that can improve phone conversations’ quality.

Revisiting Mackay Online

Revisiting Mackay Online

A Novel Approach for Profile Optimization in DOCSIS 3.1 Networks Exploiting Traffic Information

The latest release of the data over cable service interface specification (DOCSIS), namely DOCSIS 3.1, has introduced the use of adaptive bit loading profiles. The design of these profiles is critical for the overall performance of a hybrid fiber coaxial (HFC) cable system. Previous works on profile optimization for DOCSIS networks have mainly focused on grouping cable modems (CMs) based on their signal-to-noise ratio (SNR) similarity to maximize the system’s capacity. However, this approach can be inefficient due to effect of data demand and traffic variations that can highly affect the overall system performance. In this paper, we introduce a profile design approach to maximize the average throughput of an HFC system while considering the effect of both CMs’ traffic and channels SNRs on the system’s performance. Moreover, the profile optimization should not require knowledge of future instantaneous data arrival rates, which is not possible to obtain in practice. Thus, our proposed approach uses only average information which can be easily predicted using learning techniques. We show that the proposed approach yields significantly high performance, particularly for scenarios with high degree of heterogeneity in the CMs’ traffic.

How to Transition the National Broadband Network to Fibre To The Premises

NBN Co, the government business enterprise rolling out the National Broadband Network (NBN) adopted the Coalition Government’s Multi-Technology Mix (MTM) plan upon receipt of a revised Statement of Expectations following the September 2013 Federal election. The MTM NBN plan included rolling out the outdated Fibre to the Node technology and remediating and upgrading the existing Telstra and Optus Hybrid Fibre Coaxial networks. This paper discusses the migration from the MTM NBN to a Fibre to the Curb or ubiquitous Fibre to the Premises (FTTP) NBN. The paper also discusses the MTM NBN cost blowout, delays and rationale for the MTM NBN to be immediately replaced with a future-proof FTTP NBN.

QoE-Aware Bandwidth Broker for HTTP Adaptive Streaming Flows in an SDN-Enabled HFC Network

This paper proposes a software defined networking based bandwidth broker solution for improving viewer experience for any type of content delivered to any type of consumer device using HTTP adaptive streaming (HAS) in a hybrid fiber coax network. This solution is designed to meet per-session and per-group quality-of-experience objectives, to avoid common HAS culprits such as video instability, unfair and unequal quality distribution and network resource underutilization, and to scale to a large number of concurrent HAS sessions without introducing too much overhead. The mathematical framework behind our solution solves a convex optimization problem, which relies on a concave network utility maximization function. Results confirm the effectiveness of the proposed solution over the state-of-the-art bitrate adaptation and bandwidth allocation schemes.

Delta-Sigma Digitization and Optical Coherent Transmission of DOCSIS 3.1 Signals in Hybrid Fiber Coax Networks

We first demonstrate delta-sigma digitization and coherent transmission of data over cable system interface specification (DOCSIS) 3.1 signals in a hybrid fiber coax (HFC) network. Twenty 192-MHz DOCSIS 3.1 channels with modulation up to 16384QAM are digitized by a low-pass cascade resonator feedback (CRFB) delta-sigma analog-to-digital converter (ADC) and transmitted over 80-km fiber using coherent single-λ 128-Gb/s dual-polarization (DP) quadrature phase-shift keying (QPSK) and 256-Gb/s DP-16QAM optical links. Both one-bit and two-bit delta-sigma digitization are implemented and supported by the QPSK and 16QAM coherent transmission systems, respectively. To facilitate its practical application in access networks, the coherent system is built using a low-cost narrow-band optical modulator and RF amplifiers. Modulation error ratio (MER) larger than 50 dB is successfully demonstrated for all 20 DOCSIS 3.1 channels, and high-order modulation up to 16384QAM is delivered over fiber for the first time in HFC networks. The raw DOCSIS data capacity is 54 Gb/s with net user information ~45 Gb/s. Moreover, the bit error ratio (BER) tolerance is evaluated by measuring the MER performance as BER increases. Negligible MER degradation is observed for BER up to 1.5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> and 1.7 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> for one-bit and two-bit digitization, respectively.

High performance gain demodulate system for hybrid fiber-coaxial

Gigabit capable of Hybrid Fiber-Coaxial (HFC) represented an increase. The goals of the next generation HFC system are to efficiently utilize the precious last 100m of the coaxial cable and to achieve a Gigabit transmission rate. This target demands higher requirements regarding the physical layer (PHY) throughput. Firstly, the PHY architecture of next generation HFC system is given in detail. Secondly, in order to meet challenging high PHY throughput, a class of Low Density Parity Check (LDPC) code is selected as the Forward Error Correction (FEC) scheme, the ultimate choice is made on the basis of system with a better bit error rate performance. Finally, this paper combines the characteristics of Gray code symbol mapping for Quadrature Amplitude Modulation (QAM) constellation to design a soft decision algorithm based on signal diversity. Especially in terms of power efficiency, this algorithm can beyond the performance of log-MAP algorithm.

R-FFT: Function Split at IFFT/FFT in Unified LTE CRAN and Cable Access Network

The Remote-PHY (R-PHY) modular cable network for Data over Cable Service Interface Specification (DOCSIS) service conducts the physical layer processing for the transmissions over the broadcast cable in a remote node. In contrast, the cloud radio access network (CRAN) for Long-Term Evolution (LTE) cellular wireless services conducts all baseband physical layer processing in a central baseband unit and the remaining physical layer processing steps towards radio frequency (RF) transmission in remote nodes. Both DOCSIS and LTE are based on Orthogonal Frequency Division Multiplexing (OFDM) physical layer processing. We propose to unify cable and wireless cellular access networks by utilizing the hybrid fiber-coax (HFC) cable network infrastructure as fiber fronthaul network for cellular wireless services. For efficient operation of such a unified access network, we propose a novel Remote-FFT (R-FFT) node that conducts the physical layer processing from the Fast-Fourier Transform (FFT) module towards the RF transmission, whereby DOCSIS and LTE share a common FFT module. The frequency domain in-phase and quadrature (I/Q) symbols for both DOCSIS and LTE are transmitted over the fiber between remote node and cable headend, where the remaining physical layer processing is conducted. We further propose to cache repetitive quadrature amplitude modulation (QAM) symbols in the R-FFT node to reduce the fronthaul bitrate requirements and enable statistical multiplexing. We evaluate the fronthaul bitrate reductions achieved by R-FFT node caching, the fronthaul transmission bitrates arising from the unified DOCSIS and LTE service, and illustrate the delay implications of moving part of the cable R-PHY remote node physical layer processing to the headend.

Hybrid Fiber Coaxial망에서 VoIP 서비스 구현

최근 모바일기기 및 네트워크에 대한 관심이 높아짐에 따라 기존의 IP (internet protocol) 망을 이용하여 음성데이터를 전송하는 기술인 VoIP (voice over internet protocol)서비스가 급속히 확산됨에 따라 무선 인터넷망을 활용하여 언제 어디서나 저렴한 음성 통화 서비스가 가능해졌다. 그리고 디지털방송서비스가 보급되면서 방송과 통신의 융합을 통해 광대역케이블망을 이용하는 HFC (hybrid fiber coaxial)망 기술은 기존의 통신시스템 및 망설비를 활용하여 양방향 방송서비스 및 인터넷, 전화 등 다양한 신규 서비스를 제공하고 있다. 따라서 실제 HFC 인터넷서비스망에서 음성데이터의 품질보장을 위해 VoCM에 UGS-AD를 MTA에는 RTPS를 적용하면 실제 상용 HFC 인터넷서비스망에서 문제가 되는 협소한 상향대역에서의 음성데이터 전송을 원활히 수행할 수 있음을 확인하였으며, HFC 인터넷서비스 망에서 음성데이터의 QoS개선을 통해 기존 대비 개선된 VoIP서비스를 구현하는 방안을 제시하였다. As interest in mobile devices and networks has increased recently, voice over internet protocol (VoIP) service, which is a technology for transmitting voice data using an existing internet protocol (IP) network, has rapidly spread, Cheap voice call service has become possible. As the digital broadcasting service becomes popular, hybrid fiber coaxial (HFC) network technology, which uses broadband cable network through fusion of broadcasting and communication, utilizes existing communication system and network equipment to provide various new services such as interactive broadcasting service. Therefore, if UGS-AD is applied to VoCM and RTPS is applied to MTA in order to guarantee the quality of voice data in actual HFC Internet service network, it is possible to smoothly perform voice data transmission in narrow upstream band which is a problem in actual commercial HFC network We also proposed a method to improve VoIP service by improving QoS of voice data in HFC Internet service network.

Techno-economic analysis of NGNs implementation in rural areas based on the geographic and socio-demographic characteristics of Serbia

This paper presents a comprehensive techno-economic evaluation of the hybrid fiber-coax (HFC) networks and the multichannel Ethernet passive optical networks (EPONs) as two main next generation broadband technologies. The focus within this study is the comparison of these technologies in the case of their deployment in the rural area. Moreover, this paper analyzes how these technologies could be profitably deployed and what could be the optimal migration path for the operators in Europe.

Future Broadband Access Networks [Point of View

Since the development of practical optical fiber, people have been predicting the widespread introduction of broadband access. The original vision was to replace the copper telephone lines with fiber, but that has not happened. Instead, we see a wide variety of fiberdeeper architectures (where the fiber network is taken closer to the end customer), including very high speed digital subscriber line (VDSL)-based fiber to the node, data over cable service interface specification (DOCSIS)-based hybrid fiber coax (HFC), and passive optical network (PON)-based fiber to the premise. Why such a diversity? And why hasn't the best technology won? The answers to these questions may help us to understand why we have gotten to the present situation, and give us clues to what may come next.

Analysis of the dynamic broadband technology competition

Purpose – The purpose of this paper is to investigate the effect of inter-platform competition on the adoption of different broadband technologies (i.e. among xDSL, fibre-optic technologies, and hybrid fibre coaxial (HFC)), examine the direction of the effect, and identify potential technology convergence and the speed of technology innovation. Design/methodology/approach – It uses Lotka-Volterra equation to determine the dynamic competition pattern for xDSL, fibre-optic technologies, and HFC. Findings – The influence of inter-platform competition on the adoption rate may vary depending on the market conditions, the phase of the adoption period, and the types of competing technology. Even though new technology has competitive advantage, it still requires time to acquire market share. Even though fibre-optic is leading in the market, alternative technologies have also garnered significant market share in the early stage. Specifically, HFC has gained its own market position, making it a valuable alternative in the short term. Nonetheless, the market will eventually converge to fibre-optics. Originality/value – The findings show that inter-platform competition does not always exert positive influence on broadband adoption as indicated in previous literature. Instead, the influence may vary from negative to neural. This information is an important knowledge addition to the literature. Overall, the study has important implications to governmental effort in managing market competitions and in planning national broadband infrastructure policies. It also provides valuable implications on how ISPs should strategize their investment in new broadband technologies.