Showing papers on "Broadband networks published in 2010"

Wi-fi intelligent selection engine

Abstract: Devices, systems, and methods are disclosed to offload the usage of a cellular network by intelligent selection of broadband network connections such as Wi-Fi access points. A Wi-Fi transceiver on a mobile device is activated when certain conditions are met, such as a time, location, recognition of a radiofrequency (RF) environment, etc. The conditions are correlated with a database of known locations in which a one or more Wi-Fi access points are determined to exist. The Wi-Fi transceiver on the mobile device is activated and commanded to connect to a particular Wi-Fi access point. Dynamic intelligence ensures that the appropriate connection method is used, and minimizes handovers to networks or access points that are unreliable or that are predicted to become inaccessible to the mobile device.

IMT-advanced relay standards [WiMAX/LTE Update]

Abstract: There are two candidates for IMT-Advanced (4 G) standards, LTE-Advanced by 3 GPP and 802.16 m by IEEE. This article focuses on relay architectures in 16 m and LTE-A, and discusses design principles and trade-offs leading to decisions in each standards group. Basically, 16 m relay and LTE-A Release 10 relay are very similar technologies where the relay is essentially an orthogonal frequency-division multiple access base station with a wireless backhaul link. However, some open issues, such as mobility, power saving, multihop architecture, transparent relaying, multi-arrier transmission, and cooperative transmission, are still left as challenges for engineers and researchers. This article provides insights to both relay standards that could be helpful for readers to fully comprehend practical ways of incorporating relays into 4 G wireless broadband networks.

Cognitive femtocell networks: an overlay architecture for localized dynamic spectrum access [Dynamic Spectrum Management]

Abstract: We define and propose a femtocell-based cognitive radio architecture for enabling multitiered opportunistic access in next-generation broadband wireless systems. This architecture combines the conventional femtocell idea with an infrastructure-based overlay cognitive network paradigm. The cognitive femtocell concept leads to simpler and easier proliferation of cognitive radio into practical systems. We highlight the drawbacks and advantages of the proposed network structure with a discussion on research directions for cognitive femtocell architecture. We also provide experimental results to illustrate a general proof of concept for this new modality.

Quality of service in WiMAX and LTE networks [Topics in Wireless Communications]

Abstract: A quality of service framework is a fundamental component of a 4G broadband wireless network for satisfactory service delivery of evolving Internet applications to end users, and managing the network resources. Today's popular mobile Internet applications, such as voice, gaming, streaming, and social networking services, have diverse traffic characteristics and, consequently, different QoS requirements. A rather flexible QoS framework is highly desirable to be future-proof to deliver the incumbent as well as emerging mobile Internet applications. This article highlights QoS frameworks and features of OFDMA-based 4G technologies - IEEE 802.16e, IEEE 802.16m, and LTE - to support various applications' QoS requirements. A few advanced QoS features such as new scheduling service (i.e., aGP), quick access, delayed bandwidth request, and priority controlled access in IEEE 802.16m are explained in detail. A brief comparison of the QoS framework of the aforementioned technologies is also provided.

Novel Ring Resonator-Based Integrated Photonic Beamformer for Broadband Phased Array Receive Antennas—Part II: Experimental Prototype

Abstract: An experimental prototype is presented that illustrates the implementation aspects and feasibility of the novel ring resonator-based optical beamformer concept that has been developed and analyzed in Part I of this paper . This concept can be used for seamless control of the reception angle in broadband wireless receivers employing a large phased array antenna (PAA). The design, fabrication, and characterization of a dedicated chip are described, in which an 8 × 1 optical beamforming network, an optical sideband filter for single-sideband suppressed carrier modulation, and a carrier re-insertion coupler for balanced optical detection are integrated. The chip was designed for satellite television reception using a broadband PAA, and was realized in a low-loss, CMOS-compatible optical waveguide technology. Tuning is performed thermo-optically, with a switching time of 1 ms. Group delay response and power response measurements show the correct operation of the OBFN and OSBF, respectively. Measurements on a complete beamformer prototype (including the electro-optical and opto-electrical conversions) demonstrate an optical sideband suppression of 25 dB, RF-to-RF delay generation up to 0.63 ns with a phase accuracy better than ?/10 radians, and coherent combining of four RF input signals, all in a frequency range of 1-2 GHz.

Digital personal assistance via a broadband access gateway

Abstract: A system and method supporting access, coordination, modification, updating, and management of multiple sources of multimedia information resident on a plurality of access device is disclosed. A broadband access gateway may support applications that perform user services involving multiple sources of multimedia information across a network by acting as a focal point for access to multimedia information related to the applications. Using information that identifies such sources, the broadband access gateway may coordinate modification of one or more multimedia information sources based upon the content of other related sources of multimedia information. One such application may include the coordination of calendars for the planning of a meeting involving multiple participants. A representative embodiment of the present invention may identify available meeting dates and times, and the placement of reservations for appropriate travel accommodations using services accessible to the broadband access gateway via a broadband network.

Building a Green Wireless-Optical Broadband Access Network (WOBAN)

Abstract: Access networks consume a significant portion of overall Internet energy consumption. With the increase of bit-rate requirements in access networks, future-proof access technologies should be energy efficient. In this paper, we show how we can build a very high-throughput “green” hybrid wireless-optical broadband access network (WOBAN). We devise novel energy-saving techniques for WOBAN to improve its energy efficiency and network utilization. We present a mixed integer linear program (MILP) model, which acts as a benchmark for evaluating our techniques. We analyze the impact of energy-aware design and protocols on the performance of WOBAN over dynamic traffic profiles. Illustrative numerical examples show that, with suitable design parameters, we can efficiently reduce energy consumption in WOBAN without significantly impacting the network performance.

A Survey on Methods for Broadband Internet Access on Trains

Abstract: We present a survey of approaches for providing broadband Internet access to trains. We examine some of the barriers that hinder the use of broadband Internet on trains and then discuss some of the opportunities for broadband deployment to trains. This survey considers some of the basic concepts for providing broadband Internet access and then reviews associated network architectures. The review of network architectures shows that we can subdivide networks for providing broadband Internet access to trains into the train-based network, the access network-for connecting the train to the service provider(s)-and the aggregation network-for collecting user packets generated in the access network for transmission to the Internet. Furthermore, our review shows that the current trend is to provide Internet access to passengers on trains using IEEE 802.11; however, a clear method for connecting trains to the global Internet has yet to emerge. A summary of implementation efforts in Europe and North America serves to highlight some of the schemes that have been used thus far to connect trains to the Internet. We conclude by discussing some of the models developed, from a technical perspective, for testing the viability of deploying Internet access to trains.

Quality-driven cross-layer optimized video delivery over LTE

Abstract: 3GPP long term evolution is one of the major steps in mobile communication to enhance the user experience for next-generation mobile broadband networks. In LTE, orthogonal frequency-division multiple access is adopted in the downlink of its E-UTRA air interface. Although cross-layer techniques have been widely adopted in literature for dynamic resource allocation to maximize data rate in OFDMA wireless networks, application-oriented quality of service for video delivery, such as delay constraint and video distortion, have been largely ignored. However, for wireless video delivery in LTE, especially delay-bounded real-time video streaming, higher data rate could lead to higher packet loss rate, thus degrading the user-perceived video quality. In this article we present a new QoS-aware LTE OFDMA scheduling algorithm for wireless real-time video delivery over the downlink of LTE cellular networks to achieve the best user-perceived video quality under the given application delay constraint. In the proposed approach, system throughput, application QoS constraints, and scheduling fairness are jointly integrated into a cross-layer design framework to dynamically perform radio resource allocation for multiple users, and to effectively choose the optimal system parameters such as modulation and coding scheme and video encoding parameters to adapt to the varying channel quality of each resource block. Experimental results have shown significant performance enhancement of the proposed system.

Building Broadband: Strategies and Policies for the Developing World

Abstract: This book provides policymakers and regulators with the frameworks and ideas to help them design strategies and policies to support the growth of the broadband ecosystem in their countries.

Channel Modeling and MIMO Capacity for Outdoor Millimeter Wave Links

Abstract: Recent work has shown that mesh networks based on short-range outdoor millimeter (mm) wave links in the unlicensed 60 GHz band are a promising approach to providing an easily deployable broadband infrastructure. In this paper, we investigate the robustness of such links, focusing in particular on the effect of multipath fading resulting from reflections from the ground and building walls for a lamppost deployment of mm wave nodes. Our ray tracing based model shows that, while only a small number of paths are significant for the highly directional links considered, they can cause significant fluctuations in the received signal strength. Our simulations show that 10-20 dB fades below the benchmark of free space propagation can occur quite easily (e.g., 5-15% of the time, averaging across typical deployment scenarios), and that the received power is extremely sensitive to small variations in geometry (e.g., altering the position of the antenna by 1 cm can reduce the received power as much as 46.7 dB). We also demonstrate, however, that extremely robust performance can be obtained by employing multiple antennas at appropriately chosen separations, using standard space-time communications strategies such as transmit precoding (when the transmitter knows the channel) and space-time coding (when the transmitter does not know the channel).

Cost vs. reliability performance study of fiber access network architectures

Abstract: Fiber to the home is the future-proof technology for broadband access networks. Several fiber access network architectures have been developed (e.g., point-to-point, active optical network, and passive optical network). PON is considered the most promising solution due to the relatively low deployment cost and high resource efficiency. Meanwhile, because of the growing demand for reliable service delivery, fault management is becoming more significant in all parts of communications networks. However, there is a trade-off between the cost of protection and the level of service reliability. Since economical aspects are most critical in the access part of networks, improving reliability performance by duplication of network resources (and capital expenditures) could be too expensive. Therefore, recent work has focused on PON protection schemes with reduced CAPEX. The future trend will probably migrate toward minimizing operational expenditures during the access network lifetime. The main contributions of this article include providing a general method for CAPEX and OPEX analysis that can be applied to any type of fiber access network with consideration of changed component cost in time and variable take rates, and comparing the total cost (i.e., sum of CAPEX and OPEX) for the selected representative architectures with and without protection for business and residential users in relation to reliability performance. The aim is to give a guideline for the design of the most cost-effective protection schemes, while maintaining acceptable service reliability.

Usage patterns in an urban WiFi network

Abstract: While WiFi was initially designed as a local-area access network, mesh networking technologies have led to increasingly expansive deployments of WiFi networks. In urban environments, the WiFi mesh frequently supplements a number of existing access technologies, including wired broadband networks, 3G cellular, and commercial WiFi hotspots. It is an open question what role citywide WiFi deployments play in the increasingly diverse access network spectrum. We study the usage of the Google WiFi network deployed in Mountain View, CA, and find that usage naturally falls into three classes based almost entirely on client device type, which we divide into traditional laptop users, fixed-location access devices, and PDA-like smartphone devices. Moreover, each of these classes of use has significant geographic locality, following the distribution of residential, commercial, and transportation areas of the city. When comparing the network usage of each device class, we find a diverse set of mobility patterns that map well to the archetypal use cases for traditional access technologies. To help place our results in context, we also provide key performance measurements of the mesh backbone and, where possible, compare them to those of previously studied urban mesh networks.

Cost-Effective Optical Millimeter Technologies and Field Demonstrations for Very High Throughput Wireless-Over-Fiber Access Systems

Abstract: The broadband penetration and continuing growth of Internet traffic among residential and business customers are driving the migration of today's end user's network access from cable to optical fiber and superbroadband wireless systems The integration of optical and wireless systems operating at much higher carrier frequencies in the millimeter-wave (mm-wave) range is considered to be one of the most promising solutions for increasing the existing capacity and mobility, as well as decreasing the costs in next-generation optical access networks. In this paper, several key enabling technologies for very high throughput wireless-over-fiber networks are reviewed, including photonic mm-wave generation based on external modulation or nonlinear effects, spectrum-efficient multicarrier orthogonal frequency-division multiplexing and single-carrier multilevel signal modulation. We also demonstrated some applications in wireless-over-fiber trials using these enabling techniques. The results show that the integrated systems are practical solutions to offer very high throughput wireless to end users in optically enabled wireless access networks.

Understanding Broadband Speed Measurements

Abstract: Broadband speed has emerged as the single most commonly cited metric for characterizing the quality of broadband offerings However speed measurements for the same service can vary significantly These differences arise from a complex set of factors including different test methodologies and test conditions For any testing methodology, teasing apart the end-to-end tests and attributing performance bottlenecks to constituent parts is technically challenging While the broadband access network can be the bottleneck, significant bottlenecks arise in home networks, end users' computers, and server side systems and networks Consequently, inferences regarding how ISP delivered speeds compare with their advertised speeds need to be undertaken with careful attention to the testing methodologies employed Many testing methodologies are inappropriate for the purposes of assessing the quality of a broadband network

Broadband and Economic Development: A Municipal Case Study from Florida

Abstract: In this paper, we explore whether broadband investment by municipalities has an effect on economic growth. To do so, we employ an econometric model to compare economic growth in Lake County, Florida, with other similar Florida counties. In 2001, Lake County - a small county in central Florida - began generally offering private businesses and municipal institutions access to one of Florida's most extensive, municipally-owned broadband networks, with fiber optic connections to hospitals, doctor offices, private businesses, and 44 schools. Our econometric model shows that Lake County has experienced approximately 100% greater growth in economic activity - a doubling - relative to comparable Florida counties since making its municipal broadband network generally available to businesses and municipal institutions in the county. Our findings are consistent with other analyses that postulate that broadband infrastructure can be a significant contributor to economic growth. Our results suggest that efforts to restrict municipal broadband investment could deny communities an important tool in promoting economic development.

A comparative study of deployment options, capacity and cost structure for macrocellular and femtocell networks

Abstract: In this paper we will compare the cost & capacity performance of femtocell and macrocellular networks. The motivation is the possibility to use femtocells as complement or as replacement of wide area networks and hence to save investments in macrocell networks. In this study the femtocells thus are used as a tool for operators to reduce network costs for mobile broadband. This represents another business case than the often presented cases with focus on improved indoor coverage in homes with focus on voice services. Our techno-economic analysis is made as a comparative case study where capacity and cost is analyzed for wireless broadband deployed in a newly built office area with high user density. In addition to wall penetration losses we take into account; the level of user demand, the density of existing macro base station sites, the recent improvements in cost and spectral efficiency for radio access technologies, and the use of wider system bandwidths. The main finding of the study is that femtocell solutions, for the considered demand levels, are more cost efficient when new macro base station sites need to be deployed, otherwise macrocell solutions are more cost-efficient.

Physical layer for future broadband radio systems

Abstract: Future broadband radio systems have ambitious objectives in terms of performance and quality of service. Moreover, new network topologies are likely to be introduced. Therefore, the physical layer has to evolve to meet the new requirements. With this in mind, the filter bank multicarrier (FBMC) technique is proposed as an enhancement to the present OFDM technique. After a brief presentation of the FBMC principle, the adaptation to the radio context is described. Then, the main features which impact radio networks are reviewed with emphasis on the potential benefits of the evolution. The paper provides an overview of the work carried out in the European research project EC-FP7-Phydyas (physical layer for dynamic access and cognitive radio).

Computer readable medium with embedded instructions for providing communication services between a broadband network and an enterprise wireless communication platform within a residential or business environment

Abstract: The present invention sets forth computer-readable non-transitory medium having computer-executable instructions for providing network-centric service distribution method that integrates a wireless access system/service with conventional telecommunications services in the residence, SOHO, business or public environment through the use of a local broadband network, such as a Residential-Business Broadband Network (RBN). The RBN communicates with the service provider's broadband transport network and broadband packet network to facilitate end-to-end packet telecommunication services. Signals from a plurality of wireless devices are accepted and forwarded to an IEEE 802.11b interface for a wireless modem and/or to an Ethernet interface for a Voice over Internet Protocol (VOIP)/Ethernet Processor, where the forwarded signals comprise intranet telephony and data.

Optimal Relay Station Placement in Broadband Wireless Access Networks

Abstract: To satisfy the stringent requirement of capacity enhancement in wireless networks, cooperative relaying is envisioned as one of the most effective solutions. In this paper, we study the capacity enhancement problem by way of relay stations (RSs) placement to achieve an efficient and scalable design in broadband wireless access networks. To fully exploit the performance benefits of cooperative relaying, we develop an optimization framework to maximize the capacity as well as to meet the minimal traffic demand by each subscriber station (SS). In specific, the problem of joint RS placement and bandwidth allocation is formulated into a mixed-integer nonlinear program. We reformulate it into an integer linear program which is solvable by CPLEX. To avoid exponential computation time, a heuristic algorithm is proposed to efficiently solve the formulated problem. Numerical analysis is conducted through case studies to demonstrate the performance gain of cooperative relaying and the comparison between the proposed heuristic algorithm against the optimal solutions.

IEEE 1901 access system: An overview of its uniqueness and motivation

Abstract: In 2005 the IEEE P1901 Working Group began standardization activities for broadband over power line networks. The process is now in its final stages, and the latest P1901 draft standard is available for sale to the public. The standard is designed to meet both in-home multimedia and utility application requirements including smart grid. The utility requirements and the resulting features that support those requirements were clustered together and form the basis of what is referred to as the utility access cluster. This article explains the aspects of P1901 power line communication technologies designed to address the access cluster. The differences between access and in-home applications, including addressing methods, clock synchronization, smart repetition, quality of service, power saving, and other access unique mechanisms, are also explained.

Experimental Analysis of Pattern and Polarization Reconfigurable Circular Patch Antennas for MIMO Systems

Abstract: In this paper, we investigate the performance achievable with pattern and polarization multielement reconfigurable antennas in narrowband and broadband multiple-input-multiple-output (MIMO) systems by means of two-port reconfigurable circular patch antennas (RCPAs). We use field measurements collected in an indoor environment to determine the channel capacity achievable with the RCPAs when used at one or at both ends of the communication link. To conduct this analysis, we use two types of RCPAs: 1) an RCPA with two different antenna configurations, exploiting only pattern diversity and 2) an RCPA with three different antenna configurations, exploiting both pattern and polarization diversity. The benefits offered by each state (i.e., excited radiation pattern and polarization) of the RCPAs are investigated in both line-of-sight (LOS) and nonline-of-sight (NLOS) scenarios. The analysis shows the effectiveness of each array configuration in increasing the diversity level of the system and the amount of signal power received in LOS and NLOS communication links. The radiation efficiency and the level of pattern and polarization diversity of each configuration are investigated to explain the performance offered by this class of antennas in MIMO systems. Finally, we show the difference in performance achievable with these antennas when employed in narrowband or broadband communication systems.

Studies of OFDM signal for broadband optical access networks

Abstract: Using orthogonal-frequency-division-multiplexing (OFDM) format for passive optical network (PON) is a subject of great interest for recent research works. OFDM signal has high spectral efficiency, high tolerance to the fiber chromatic dispersion and the high flexibility on both multiple services provisioning and dynamic bandwidth allocation. In this paper we study the use of OFDM signals for optical access networks, including carrier distributed PON, heterogeneous optical wired/wireless network and a 100 Gb/s OFDM-PON. We first quantify the performance of the OFDM signal when subjected to the noise produced by two different Rayleigh backscattering (RB) components that are present in the carrier-distributed PON. Then, based on these results, we also study the possibility of using OFDM for signal remodulation in a long-reach (LR)-PON. We propose carrier-distributed OFDM PONs using a dual-feeder fiber architecture and wavelength-shifting to mitigate the RB noise. Afterwards, we propose heterogeneous optical wired/wireless access networks, combining 10 Gb/s PON and 10 Gb/s OFDM radio-over-fiber (ROF) network. Finally, we propose a 100 Gb/s OFDM-PON using subcarrier multiplexing (SCM).

Channel management in IEEE 802.22 WRAN systems

Abstract: Channel management policy is one of the key functions of any cognitive radio system. The channel management decision in a cognitive radio system depends on various factors such as government regulations, limitations of transmission power between communicating devices, availability of geo-location information, and the quality of various available channels. The main purpose of channel management in a cognitive radio system is to protect the incumbent users (licensed users). The first international standard based on cognitive radio technology is IEEE 802.22, Wireless Regional Area Networks, which aims at providing broadband access in rural areas by effectively utilizing the unused TV channels. This standard aims at describing both PHY and MAC layer functionalities in an infrastructure- based broadband wireless access network for communication between consumer premises equipment using a base station. This article presents the cognitive radio functionality of this standard in detail. The cognitive functionality is provided by the dynamic channel management using channel sensing, channel classification, and maintenance of channel information. Using these techniques, this standard effectively protects the incumbent users and dynamically manages the channel allocation in IEEE 802.22 WRAN systems.

A two-level scheduling algorithm for QoS support in the downlink of LTE cellular networks

Abstract: Long Term Evolution represents an emerging and promising technology for providing a broadband ubiquitous Internet access. But several aspects have to be considered in order to provide an effective service to users. In particular, in this work, we consider the problem of optimizing the performance of real time downlink communications using a novel two-level scheduling algorithm. The upper level exploits an innovative approach based on discrete-time linear control theory. At the lower level, instead, a maximum throughput scheduler has been properly tailored to our purposes. The performance and the complexity of the proposed scheme have been evaluated theoretically and by using simulations. Both the analyses demonstrate the effectiveness of the proposed approach.

Broadband Transmission via Underground Medium-Voltage Power Lines—Part II: Capacity

Abstract: The end-to-end transfer function of three-phase underground medium-voltage broadband over power-lines (MV/BPL) cables with common shield and armor is determined based on a new exact version of the chain scattering matrix method. The various topologies of the underground MV grid are studied with regard to the spectral behavior of the end-to-end attenuation and to the respective capacity and are compared to the corresponding overhead cases. The numerical results reveal that broadband transmission via underground MV power lines depends drastically on the type of cables used and the topology of the underground MV grid. Also, the relaxed power injection limits and the lower noise power levels characterizing underground MV/BPL transmission counteract the extremely high inherent attenuation, making the capacity achieved compatible to that achieved in overhead MV/BPL transmission.

Energy Source Aware Target Cell Selection and Coverage Optimization for Power Saving in Cellular Networks

Abstract: The spread of mobile connectivity is generating major social and economic benefits around the world, while along with the rapid growth of new telecommunication technologies like mobile broadband communication and M2M (Machine-to-Machine) networks, larger number of various base stations will be employed into the network, which will greatly increase the power expense and CO2 emission. In order to degrade the system power expense, variety of researches on new energy and novel transmission technology are put in agenda. In this paper, instead of reducing the absolute power expense, the research focuses on guiding more power consumption into green source energy, which implying that the UEs (User Equipment), especially the cell edge UEs, will have preferential access to the BSs (Base Station) with natural energy supply. To realize the tendentious connection, two detailed approaches are proposed, the HO (Hand Over) parameter tuning for target cell selection and power control for coverage optimization. The system evaluation shows that, by proper setting of parameters in HO and power control, both of the two approaches can achieve good balance between energy saving effect and system throughput impact.

WiMAX or LTE: Who will Lead the Broadband Mobile Internet?

Abstract: Two main technologies are competing for the International Mobile Telecommunications (IMT)-Advanced initiative: WiMAX and LTE. This comparison reviews their development and deployment and provides an outlook on their adoption as 4G technologies.

Open access networks, the Swedish experience

Abstract: In the open access network model, the roles of the service provider and the network owner are separated, and the service providers get access to network and the end customers on fair and non-discriminatory conditions. This should be compared to the traditional vertically integrated business model where the service provider and the network operator are the same. A large number of open access networks have been deployed in Sweden over the last 10 years. In this paper we give an overview of such networks, draw conclusions from the Swedish experiences with open access, and outline the perspectives for future deployments both within and outside ol Sweden.

Traffic analysis and characterization of Internet user behavior

Abstract: Internet usage has changed, and the demands on the broadband access networks have increased, both regarding bandwidth and QoS. Characterizing the traffic, as seen by a broadband access network, can help understanding both the demands of today and the demands of tomorrow. In this paper we analyze traffic measurements from a Swedish municipal broadband access network and derive corresponding user behavior models. The paper focuses on Internet usage in terms of traffic patterns, volumes and applications. Also, user activity characteristics, as session lengths and traffic rate distributions, are analyzed and modeled. Notably, the resulting models for user session lengths turn out different than traditionally assumed.