Cable Modem Research Articles

Low Power Blind Adaptive Equalizer with Word Length Optimization Algorithm

power VLSI is a promising area for developing advanced wireless communication systems. The optimum word length selection for each signal in algorithm is crucial for low power design. This paper proposes a scheme for Word Length Optimization (WLO) using system level parameters such as dynamic range and SNR. The Blind Adaptive Equalizer for channel equalization is optimized with the proposed technique for fixed point implementation in VHDL. Simulation is carried out in MATLAB and also VHDL. Considering IEEE 802.16 wireless broadband network and DSL cable modem standards, the results are validated for Energy per Symbol to Noise density (Es/No) values 8 dB and 12 dB. Power saving up to 34% is observed for Xilinx's Virtex-6 FPGAs, in comparison with conventional implementation. The result shows promising direction of optimization with good scope of automation for low power wireless applications. The suitability of adopted WLO scheme in the context of High Level Synthesis (HLS) is discussed.

Market definition for broadband internet in Slovakia – Are fixed and mobile technologies in the same market?

This paper uses a rich survey of 6446 households in Slovakia to estimate price elasticities of demand for Internet access, and draw implications for market definition. We estimate a mixed logit model, in which households choose between different broadband technologies: DSL, cable modem, fibre, WiFi and mobile. We find that a number of household characteristics influence the technology choices, and there is also significant unobserved heterogeneity. Demand for Internet access is highly price sensitive. The price elasticity of demand for DSL is −3.02, which falls in the middle of the range of elasticities for the other technologies. Furthermore, the price elasticity of demand at the level of all fixed broadband technologies (DSL+cable modem+fibre+WiFi) is equal to −1.98. For a reasonable range of profit margins, this estimate implies that mobile broadband should be included in the relevant antitrust market of fixed broadband. Our findings have implications for competition policy in Central and Eastern European countries where due to poor copper networks mobile broadband is an important alternative to fixed broadband.

A new dynamic bandwidth allocation algorithm based on online–offline mode for EPON

In parallel with the enormous spread of Internet usage, the tendency of users for high capacity applications (HDTV, Online Games, P2P File Transfer) are rising. This increase in needs of data communication, compel the service providers to act to end users better than before. At this point, Passive Optical Networks (PONs) distinguish in access network solutions due to its capability of carrying high amount of data over longer distances. Although they are still in development, existing electronic based data communication techniques (ADSL, double twisted copper telephony systems like VDSL, cable modem coaxial cable CATV systems) can operate over short distances and have large amount of energy consumption. In this paper, basic schemes of dynamic bandwidth allocation algorithms on EPON have been presented and a novel online–offline based method called hcDBA (Half Cycling Dynamic Bandwidth Allocation) has been introduced. In addition, hcDBA algorithm has been improved with early prediction mechanism (p-hcDBA). By the simulation studies, it has been investigated that hcDBA algorithm performs better than existing mechanism in terms of byte loss ratio and access delays criteria. p-hcDBA also improved the performance in terms of access delay. In this study, we stated that when the bandwidth increases the prediction approached has more impact of the overall performance.

Broadband prices in the European Union: Competition and commercial strategies

This paper analyses the determinants of broadband Internet access prices in a group of 15 EU countries between 2008 and 2011. Using a rich panel data set of broadband plans, we find a positive effect of downstream speed on prices, and that the price per Mbps of cable modem and fibre technologies is lower than that of xDSL. Operators’ marketing strategies are also analysed as we show how much prices rise when the broadband service is offered in a bundle with voice telephony and/or television, and how much they fall when download volume caps are included. The most insightful results of this study are provided by a group of metrics that represent the situation of competition and entry patterns in the broadband market. We show that consumer segmentation positively affects prices. Moreover, broadband prices are higher in countries where entrants make greater use of bitstream access and lower in countries where there is an intensive use of direct access (local loop unbundling). We do not find a significant effect of inter-platform competition on prices.

Developments in Regulating High-Speed Internet Access: Cable Modems, DSL, & Citywide Wi-Fi

Developments in Regulating High-Speed Internet Access: Cable Modems, DSL, & Citywide Wi-Fi

Brand X Internet Services v. FCC: The Case of the Missing Policy Argument

People seeking Internet access through their cable lines may soon have new choices. Today, a consumer with Comcast Cable can only purchase cable modem service from Comcast or a Comcast-affiliated provider, usu ally a Comcast subsidiary.1 If the decision in Brand X Internet Services v. Federal Communications Commission2 is upheld by the United States Su preme Court, that consumer will eventually be able to choose from other cable Internet Service Providers (ISPs) operating on Comcast's connection to the customer's home.

Forecasting the fiber penetration based on copper access regulation

Purpose – This paper aims to investigate the impact of copper access regulation on broadband household adoption for each technology (xDSL on copper infrastructure, FTTx on fiber infrastructure and cable modem). It provides a forecast of the penetration rate of broadband access for each technology (copper xDSL, fiber, FTTx and cable modem) through 2020. Design/methodology/approach – This paper uses an empirical approach using a dataset covering 15 European countries. The dynamic of the adoption path is modeled by a logistic function. Copper access regulation is measured by two variables: copper access charge and copper wholesale access share, i.e. the ratio of copper wholesale access provided by the incumbent to alternative operators out of the total number of copper accesses. Findings – This paper shows that tough copper access regulation has a negative impact on fiber and cable modem adoption. Low copper prices decrease consumer adoption of other technologies. This reduces their profitability and thus the incentives to invest in alternative platforms. Practical implications – This paper highlights that an increase in copper access charges or a decrease in copper wholesale access shares could help to achieve the objectives of the Digital Agenda for Europe. Originality/value – This paper provides an empirical evidence of the impact of the copper access regulation on the fiber and ultra-fast broadband adoption from a dynamic point of view.

A 40-MHz-to-1-GHz Fully Integrated Multistandard Silicon Tuner in 80-nm CMOS

To address a worldwide market, silicon tuners have to support a wide range of frequencies and standards, motivating the use of architectures inspired by the software-defined-radio paradigm. DVB-T, DVB-C, ATSC-A/74 as well as cable modems (DOCSIS) and analog TV require low-noise, high-linearity front-ends with high-performance local oscillators. Integrability and cost dictate minimization of external components. Unlike common approaches [1,2], the silicon tuner presented in this paper features one single-ended RF input for the entire 40MHz-to-1GHz band, requires no external SAW filters or balun, and supports channel bandwidths from 5 to 8MHz. The analog IF output is programmable from 5MHz to 44MHz, supporting both modern digital demodulators and legacy analog demodulators. The receiver uses a low-IF architecture and is able to process the broadband input spectrum through the combination of a low-noise programmable RF filter, a digitally calibrated harmonic-rejection mixer, and a wide dynamic range ADC, whose intrinsic filtering nature and large SNDR make the tuner compatible with the very demanding ATSC A/74 standard. The chip's sophisticated digital back-end provides channel filtering and image rejection for the signal path, runs the RF and IF AGCs, and controls a variety of calibration schemes used to improve performance and robustness toward PVT variations. The chip has been designed in a scaled 90nm CMOS technology, requires a 1.8V analog supply and a 1.0V digital supply, and dissipates <450mW during normal operation and <10mW in standby mode. The BoM is limited to a single LNA bias inductor and a 40MHz crystal, thus minimizing the required footprint and cost.

Estimating broadband diffusion in the EU using NUTS 1 regional data

In this paper we use panel data on NUTS 1 regional data for 27 EU countries in the years 2006–2010 to analyze determinants of broadband diffusion. We estimate both linear demand specification and the logistic diffusion function. We find that, after controlling for regional differences due to socioeconomic factors, inter-platform competition approximated by an inter-platform Herfindahl index has a significant positive impact on broadband diffusion. Broadband deployment is lower in countries in which DSL has a greater share in Internet access and it is higher in countries in which cable modem has a greater share in Internet access. Moreover, we find that competition between DSL providers has a significant and positive impact on broadband penetration. First, higher prices for a fully unbundled local loop connection, which represent the cost of providing copper-based Internet services, have a significant and negative impact on broadband penetration. Second, a greater incumbent share in DSL connections has a significant and negative impact on broadband penetration.

IIDWBA algorithm for integrated hybrid PON with wireless technologies for next generation broadband access networks

Optical and wireless technology integration has been proposed as one of the most promising nominees for the next-generation broadband access networks for quite some time. Integration scheme merges the high-speed and high-capacity of the optical networks with the low-cost, wide-coverage and mobility features of the wireless counterparts for the Subscriber Stations (SSs). It is also financially viable for the telecommunication service providers, particularly in the rural area where the development of optical infrastructure or expansion of the existing telecommunication solutions such as Digital Subscriber Line (DSL), Cable Modem (CM) or T-1/E-1 networks are either too costly or unreachable. In order to successfully integrate the two technologies, there are some technical concerns in terms of Architectural aspects, Physical Layer features and Media Access Control (MAC) related issues, which need to be addressed efficiently in order to provide the smooth end-to-end (e2e) integration. This paper is mainly focused upon the analysis of the key topics in MAC-related issues such as E2E wavelength/bandwidth requests and allocations over the converged scenario. It proposes an Inter-channel and Intra-channel Dynamic Wavelength/Bandwidth Allocation (IIDWBA) algorithm where the hybrid Passive Optical Network (PON) acts as a back haul technology for the wireless counterpart. The proposed algorithm works in three phases, namely, Initialisation, Intra-channel bandwidth allocations and Inter-channel bandwidth allocations and is capable of allocating wavelength/bandwidth efficiently and effectively over the converged scenario. Performance of the proposed algorithm is evaluated through conducted simulation scenarios under different simulation parameters, traffic patterns and load values. According to the captured results, IIDWBA algorithm shows a better performance when it is compared to the scenario in which it has not been employed.

The Internet is a Packet-Switched Telecommunications Network

For the second time in five years, the D.C. Circuit in Verizon v. FCC has struck down the jurisdictional theory relied upon by the FCC in creating its Open Internet rules, because the Commission still classifies Internet connections as information rather than telecommunications services. Since the Supreme Court’s decision in Brand X, most legal scholars have considered the question of whether the FCC may choose to regulate Internet access as an information service to be settled law. Drawing on a detailed analysis of the regulatory treatment of protocol processing in the Computer Inquiries and the technical structure of Internet Protocol networks themselves, this essay argues that conventional wisdom is mistaken. The view of ISPs as intermediaries that necessarily store or transform user data is anachronistic, likely taken from the operation of ISPs’ most visible predecessors, online services like CompuServe and America Online. Further, the issue in Brand X was the unbundling of last-mile cable modem transmission facilities, not an end-to-end Internet Protocol service. The factual assumptions underlying the former decision do not hold in the Internet context, a conclusion this paper demonstrates in a way easily replicated by any network engineer. Because of this faulty premise, Internet governance in the U.S. is again dealing with classic telecommunications issues — interconnection, non-discrimination, and vertical integration, but disconnected from existing law and historical precedent.

On the Performance Analysis of Energy-Efficient Upstream Scheduling for Hybrid Fiber-Coaxial Networks with Channel Bonding

We develop a novel QoS-aware energy-efficient upstream traffic scheduling algorithm for channel-bonding cable modems (CMs) in hybrid fiber-coaxial (HFC) networks. Based on their QoS requirements, the algorithm sends incoming packets to different priority queues and controls channel-bonding transmitters (TXs) to forward them. Based on a vacation M/M/n queuing model, we analyze the algorithm's performance with a three-dimensional Markov chain and derive the analytical expressions of packet delay and power consumption.

Sustainable Broadband: A Monitoring Framework for Broadband Policy in Rural Areas in the Netherlands

As General Purpose Technologies (GPTs) (Bresnahan & Trajtenberg, 1995), information and communication technologies (ICT) have been applied in different ways across companies and regions. The differences in ICT adoption across regions have been approached from a variety of perspectives, e.g. from the business users (Forman, 2005) and residential users point of view (Goldfarb & Prince, 2008) showing that regional differences are key characteristics of ICT growth. But these spatial disparities have to be approached with caution as technological characteristics of broadband are important to define rural areas (Grubesic & Murray, 2002). Even if rural areas in the European Union are defined according to technological and geographical dimensions (CEU, 2012), there is ample of room for a variety of interpretations by market parties and local governments. In case of (local) government intervention in broadband markets, there is a need to evaluate broadband initiatives with respect to their economic benefits in rural areas. In order to evaluate the economic impact of broadband, numerous studies in particular in the United States have been conducted to examine the link between broadband availability and a number of economic characteristics of rural regions (Connected Nation, 2008; Gilllett, Lehr, Osorio, & Sirbu, 2006; Whitacre, Gallardo, & Strover, 2013). Just recently the literature has focused on elements which will put broadband on a sustainable path, i.e. taking environmental implications of ICT into account (Ropke, 2012). A number of evaluation exercises of broadband programs have been conducted showing that “encouraging broadband adoption is only part of a larger digital literacy effort, and programs work when they make non-users want to connect, make the Internet cheaper and easier to use, and adjust to users’ preferences” (Hauge & Prieger, 2010). However, there currently there is no generally accepted monitoring framework that can be used to evaluate and monitor the (social) costs and benefits of broadband programs in rural areas. The paper contributes to the discussion in providing a monitoring framework for sustainable broadband in rural areas. This framework is developed by using the (social) cost-benefit analysis (SCBA) methodology applied to (all) large infrastructure programs in the Netherlands since 2003 (Eijgenraam, Koopmans, Tang, & Verster, 2000). This methodology is applied to investigate the implementation of broadband technologies in rural areas. In this context, a DPSIR scheme (originally developed as a framework for environmental indicators) is applied to monitor and a SCBA to evaluate the choice between the different alternatives (Eijgenraam, et al., 2000). As proposed by Ramirez (2007), such alternative monitoring framework is needed to evaluate economic progress in rural areas (Ramirez, 2007). As part of NGA networks (CEU, 2009, 2012), fiber technologies are increasingly considered by provincial governments in the Netherlands as the most future-proof technology of broadband infrastructure in rural areas. Different provinces in the Netherlands have set up large infrastructural broadband funds aimed at stimulating local economic development and bridging the digital divide between rural and urban areas (Provincie Noord-Brabant/ Dialogic, 2012; Provincie Overijssel, 2010). It is expected that fiber technologies will provide higher value-added to society (compared to traditional broadband technologies such as DSL or cable modem technologies) over the long term. For rural areas, these benefits have, in particular, been related to the arrival of e-health services, teleworking and the renewal of rural areas. For residential users, benefits from e-health services are emerging due to smart homes solution supporting greater self-reliance of the elderly which allow people to stay longer at home. For business users, benefits from teleworking are related to the reduction of travel time (Van der Wee et al., 2012). New NGA technologies can also support the renewal of rural areas (McGranahan & Wojan, 2007; Stephens & Partridge, 2011). To complicate matters, provincial governments are facing a number of options with respect to evaluating different project proposals for rural broadband. For example, to what extent do these proposals reflect the goals of provincial plans for rural areas (e.g. do they support renewal of rural areas; do they improve or enhance self-reliance of inhabitants?); to what extent do these proposal opt for the “right” NGA network technology?; do they support a competitive supply structure and new trans-sectoral services? In this context, a monitoring framework for broadband policy in rural areas in the Netherlands will provide more certainty with respect to interventions by provincial government, a better evaluation of the emerging (social) benefits and their allocation with respect to the different stakeholders in provincial programs.

Forecasting the Fiber Penetration According to the Copper Access Regulation

This paper investigates the impact of the copper access regulation on broadband adoption in each technology (xDSL on copper infrastructure, FTTx on fiber infrastructure and cable modem). We modelize adoption with a logistic function. Using a 15 European countries dataset we find a negative impact of copper access regulation on fiber and cable modem adoption. The copper access regulation is measured by two variables: The copper access charge and the copper wholesale access share, i.e. the ratio of copper wholesale access provided by the incumbent to the alternative operators on the total number of copper access). The model allows us to forescast the rate of penetration of broadband access according to the technology (copper xDSL, fiber, FTTx and cable modem) until 2020. An increase of copper access charge or a decrease of copper wholesale access share could help to achieve the objectives of the digital agenda.

Measurement system design and implementation for grid-connected marine substation

A marine substation for a grid-connected wave power plant has been designed and constructed at Uppsala University. The measurement system for the substation has been developed from basics, and the procedure is described in this article. Subsea electrical installations set high constraints on the control and data acquisition systems used, and traditional GSM networks and GPS time synchronization are difficult and inefficient. These circumstances exclude many well-proven methods to be utilized. A compactRIO-based system, with integrated real-time controller and Field-Programmable Gate Array chip, is chosen as most suitable for this task. The system is designed to meet the special requirements encountered in this unusual application, including large data sampling, grid connection control and protection systems. The system is communicating to shore via a subsea copper cable and single-pair high-speed digital subscriber line modems. The design was successful and full-fills all the system requirements. The aim of the article is to provide future researchers with a good design and implementation procedure for setting up large measurement systems.

Research of CMTS Based on Passive Optical Network

This paper presents the implementation of CMTS (Cable Modem Termination System) with PON (Passive Optical Network) technology to transfer IP data in HFC (Hybrid Fiber-Coax) network. By describing the theoretical basis and main function of each module, we introduce work principle of this device: converted the format of data transmitting in HFC network so that it can transfer in IP network, then achieved the aggregation of IP data to transport layer device by PON technology. The results show that the SNR is high and the bandwidth achieves expected value, so this design scheme is feasible.

Design, Simulation and Implementation of the Ethernet Simplified MAC Together With the P2MP Emulation Layer for EPON ONU Devices

The market demand for providing higher bit rate within the access network has raised the requirement of deploying the Ethernet Passive Optical Network (EPON) to replace the old technology based on Digital Subscriber Line (DSL) and Cable Modem (CM). This paper presents the design, simulation and implementation of the Simplified Ethernet Medium access Controller (MAC) together with the Point-To-Multi-Point (P2MP) emulation mechanism that can be used for Optical Network Unit (ONU) devices.

Design of Energy-Saving Algorithms for Hybrid Fiber Coaxial Networks Based on the DOCSIS 30 Standard

We propose energy-saving algorithms to improve the energy efficiency of hybrid fiber coaxial (HFC) networks that support DOCSIS (Data Over Cable Service Interface Specification) 3.0 standard. The algorithms incorporate a traffic-aware approach and modify the operation statuses of the two primary network elements, the cable modem (CM) and the cable modem termination system (CMTS), dynamically. For the CM-side operation, we first propose a basic algorithm that can optimize the CMs’ energy efficiency, regardless of significant increase of the packet delay and the number of operation changes (NoOC). We then propose two modified approaches to reduce the packet delay and NoOC while saving energy. Simulations with these algorithms show 37.5%–42.2% energy saving on the CM side, compared to the traditional case where the CMs’ operation statuses are static. Next, we propose a CMTS-side energy-saving algorithm to find the actual connection mapping between the CM channels and CMTS ports. The proposed algorithm tries to support CM connections with minimal numbers of CMTS ports. To further improve the energy efficiency of the CMTS, we design a readjustment approach that can reorganize CM connections on CMTS ports based on their loads. Simulation results show that 31.08%–32.61% energy saving can be achieved on the CMTS in total. Hence, the proposed algorithms achieve effective energy saving on both the CM and CMTS sides.

Service Bundling and Churn of Fiber Users: Evidence from the Netherlands

In Europe, switching of broadband users has been a key problem for internet service providers (ISPs) for some time now (CEC, 2009). In the Netherlands, ISPs have introduced a form of self-regulation in the industry in order to influence the switching behavior of broadband users. Churn of broadband users has been at rates of around 3.5 percent over the past five years (OPTA, 2010). To deal with churn of broadband users, ISPs have offered a large variety of service bundles aimed at segmenting the residential broadband market based on speed and bundling differences. There has been a “sharp uptake” of triple-play and double-play bundles in the Netherlands since 2006 (CEC, 2009). As a result, the Netherlands has not only achieved one of the highest levels of broadband penetration in the world (OECD, 2012), but is also leading with respect to service bundles offered in Europe (CEC, 2009). Interestingly, residential broadband users often choose a service bundle not only based on a (lower) price tag, but are willing to pay (premium) prices for higher internet speed even if the service bundle remains (practically) unchanged. In particular, the (collective) switching pattern of residential users preferring fiber access over traditional (xDSL and Cable modem) broadband access technologies has been an example of this trend (Sadowski, Nucciarelli, & de Rooij, 2009). Due to competitive pressure and technological challenges posed by traditional broadband providers, ISPs offering fiber based access have become affected by churn of residential users. In the literature, competitive bundling has been considered as a strategic option to reduce churn by users (Belleflamme & Peitz, 2010). In contrast to conventional product bundling, service bundling (i.e. the promotion of two or more separate services e.g. TV, Internet or Telephony in a package at a single price) by ISPs has been aimed at either attracting new users to or preventing existing users from leaving the network (Prince & Greenstein, 2011). In this context, the paper examines the extent to which bundles provided by an ISP have an effect on residential users leaving the fiber network between 2009 and 2011 at a time when triple play service became pervasive in the Netherlands. Due to data limitations, research on churn of residential users on fiber networks has been rather scarce as most large scale surveys do not sufficiently distinguish between different categories of broadband. As a result, a number of propositions have been put forward in the literature ranging from churn rates which are “no different” (compared to traditional broadband networks) to churn rates which are “close to zero” . In the paper, churn, i.e. the abandonment of an ISP by an existing user (household), is linked to extent to which residential users adopt different service bundles by the ISP. To examine churn, we used data on the socio-economic characteristics of residential users from an on-line survey carried out in July 2009 (about 2,700 respondents) in the Eindhoven area in the Netherlands and linked it to survey data in 2011. The paper employs a dynamic probability panel model to explain household choices. The paper shows that service bundling has been an important factor in retaining residential users on the fiber network and to reduce churn. In particular, different service bundles involving TV services and a (high) preference of residential users for (higher) internet speed have been crucial for residential users to keep their existing subscription.

RF Transport Over Optical Fiber in Urban Wireless Infrastructures [Invited

The technology for transport of RF signals over optical fibers at long (metropolitan-scale) distances which enables today's hybrid fiber/coax networks for community antenna TV and cable modem access is being leveraged for coverage and capacity enhancements in wireless networks providing affordable anywhere/anytime services. This is particularly important in high-traffic urban and in-building arenas where RF propagation is challenging. A hybrid Fiber/Cable (HFCa) approach utilizing legacy urban cabling infrastructures is shown to be highly cost effective, since the installation cost (which often dominates over equipment cost) is greatly reduced or eliminated. Optimum HFCa system architectures are discussed in this paper with Ca = C (coax) and C5 (Cat-5 unshielded twisted pair cables) for outdoor urban/metropolitan and indoor/in-building arenas, respectively. The general results in this paper apply to both. A quantitative evaluation of capacity gain by traffic trunking in a distributed antenna system is given. All-fiber RF transport for remote radio head systems serving outdoor metropolitan areas is briefly discussed.