The BREAD - co-ordination action, funded by the European Commission through the Framework 6 Programme (FP6) aims at developing a multi-disciplinary approach for the realization of the 'Broadband for All' concept within Europe, bringing together societal, economic, regulatory and technological disciplines and presenting information from regional "success stories" of actual deployment. The EU objective of achieving "Broadband for All" will not be reached by solely a 'technology push' strategy but will need this multi-disciplinary approach and sharing of views and knowledge to develop new strategies and good practice recommendations in the area of 'Broadband for All'. As a co-ordination action the project wants to unite all players active in the field of the end-to-end broadband provisioning for all. It performs a multi-technological analysis of the current and evolving situation, starting from the roadmap information generated by different projects and IST instruments which focus on specific technological domains. The BREAD consortium simultaneously studies the techno-economic, societal and regulatory aspects of this "Broadband for All" concept. It tries to identify the impact of the EU regulatory framework on the successful implementation of new broadband communication services.

FAST Copper is a multi-year, U.S. NSF funded project that started in 2004, and is jointly pursued by the research groups of Mung Chiang at Princeton University, John Cioffi at Stanford University, and Alexader Fraser at Fraser Research Lab, and in collaboration with several industrial partners including AT&T. The goal of the FAST Copper Project is to provide ubiquitous, 100 Mbps, fiber/DSL broadband access to everyone in the U.S. with a phone line. This goal will be achieved through two threads of research: dynamic and joint optimization of resources in Frequency, Amplitude, Space, and Time (thus the name 'FAST') to overcome the attenuation and crosstalk bottlenecks, and the integration of communication, networking, computation, modeling, and distributed information management and control for the multi-user twisted pair network.

The European MUSE project, which aims to enable "MUlti Service and access Everywhere", studies architectures, technologies and business scenarios facilitating the deployment of new Broadband Access Networks and Services. This paper gives an overview and particularly discusses results of some of the high-speed access technologies that are developed.

High-speed communication using the copper network, originally installed for telephony, is one of the dominant Internet access techniques. Several variants of a technology referred to as digital subscriber line (DSL) have been developed, standardized and installed during the last two decades. Essentially, DSL achieves high rates by exploiting wide bands of the copper cable channel. The shorter the cable, the wider the band that can be used efficiently for communication. Current DSL standards foresee the use of bands up to 30MHz. Cable properties have been studied by means of measurements, characterization and modeling up to frequencies of 30MHz. Recent investigations have shown that it is feasible both from technical and from economical point of view to exploit very short cables (up to 200m) even further and use bands above 30MHz. A prerequisite for further evaluation and the design of such ultra-wideband copper (UWBC) systems is the extension of existing cable models to higher frequencies. This paper presents wideband measurement results of insertion loss and crosstalk coupling in a 10-pair cable of various length values for frequencies up to 200MHz. We compare the results with extrapolations of cable models that are established in the 30MHz-range.

Digital broadcasting service and variety of communication services, 4th generation mobile, broadband wireless-LAN etc. are developed recently. Broadband wireless service over fiber technologies may play an essential role for emerging integrated services of broadcasting and communications in the area of entrance network. Low-distortion transmission of broadband radio signals are developed as a collaborative work of Osaka University, Advanced Telecommunication research Institute (ATR) and Osaka Institute of Technology supported by Strategic Information and Communication R&D Promotion Program (SCOPE) of Government.

Fiber to the home (FTTH) is now the most popular fixed Internet access service in Japan; it has been attracting far more customers than ADSL since early 2005. Gigabit-capable passive optical networks (PONs) have been proven to be the most promising approach since they realize not only point-to-multipoint bidirectional connections for broadband data communication but also video distribution in a very cost effective manner. This paper first reviews such PON technologies as well as other optical technologies to support the massive deployment of these PONs in terms of further reducing the cost, especially with regard to operation/installation and to further increasing user friendliness towards the full-scale FTTH era. It next discusses possible technical directions for future optical access networks (OANs), and review recent research towards them. Wavelength-division multiplexing (WDM) is one of the important technologies in realizing the future OANs.

This paper proposes a novel Ethernet-based wired/wireless broadband access networking architecture that utilizes the existing wired trunk feeder fiber of typical PON infrastructure along with a hybrid FSO/RF reliable wireless connectivity to the end-users. By combining the benefits of both FSO and RF technologies, the proposed integrated networking solution can provide a downstream bandwidth of up to 2.5 Gbps per wavelength and 99.999% availability at a range of 1 km in all weather conditions [2]. All the previous work on hybrid FSO/RF was based on point to point, our proposed architecture is unique in the sense of providing point to multipoint access to end users and bringing all wired/wireless network in to single network, which is transparent to the users.

This paper proposes new resource management schemes for multiple data streams in an orthogonal frequency and space division multiplex access (OFSDMA) system using Radio-on-Fiber (RoF) ubiquitous antennas. The proposed schemes classify the services into some classes in which the number of sub-carriers is dynamically assigned according to the requested data rate. The computer simulation results show that the proposed schemes improve the number of users satisfying the required bit error rate (BER) level as well as the average throughput and also show that the RoF ubiquitous antennas can improve system capacity.

Designing broadband access networks involves selecting the topology that satisfies the network requirements, and comparing the performance of different what-if scenarios in order to achieve the optimal network layout. Modeling software tools are instrumental for each phase of the design cycle and help answering to complex questions such as what is the impact of single- and multi-mode fiber linear and nonlinear effects, what is maximum fiber length before eye closure, how many regenerators are needed and where they have to be placed. This paper shows through a series of examples how modeling tools can be used for single- and multi-mode broadband access network design and planning.

The linear optical intensity modulator is a key component in any broadband optical access-based analog fiber-optic link systems such as sub-carrier multiplexing (SCM) systems, ultra-dense CATV, Radio-over-Fiber (RoF) communications, and other platform access systems. Previously, we have proposed a super-linear optical modulator, having SFDR = 130 -140 dB-Hz^2/3, based on a unique combination of phase-modulator (PM) and a weak ring resonator (RR) modulator within a Mach-Zehnder interferometer (MZI). We presented some of its unique features. In this paper, we characterize further this ultra-linear optical intensity modulator, analyze its RF performance and provide method for parameter optimization. Other excellent features of this modulator design such as high manufacturing tolerance, effect of link insertion loss, adaptive characteristic and device simplicity are also discussed.

Radio Frequency (RF) communications are generally reliable and well understood but cannot support emerging data rate needs unless they use a large portion of the precious radio spectrum. Free Space Optical (FSO) communications offer enormous data rates but operate much more at the mercy of the environment. The perennial limitations of FSO communications are manifested in the channel attributes of scintillation (optical turbulence) and path obscurations. Both phenomena reduce the availability of the optical channel to support reliable communications. Since RF paths are relatively immune to the same phenomenology, combining the attributes of a high data rate but bursty link (FSO) with the attributes of a low data rate (by comparison) but reliable link (RF) could yield attributes better than either one alone: high availability with high data rates. This paper is based on a recently devised system that uses ultra-short pulses of laser light that provide greater bandwidth and improved reliability over conventional optical wireless links. The approach uses a technique called "Fractal Modulation", which is a form of Wavelet Packet Modulation (WPM), to produce wavelets that can co-exist in a signal channel without interference, and provide frequency and time diversity, concurrently. By sending the same message at several different rates (multi-rate), one can get through adverse weather conditions. Also, in this paper we investigate channel equalization and channel coding for such a multi-rate communications scenario. As for the equalization, we considered a MMSE linear equalization after photo-detection. For the channel coding, we have used Fountain Codes, a new class of erasure correction codes, in concatenation with an inner convolutional code. We argue that for a parallel multi-rate system Fountain coding is a flexible method for receiving data from multiple streams.

High-speed free-space communications have been increasingly studied for applications ranging from short-distance ground-to-ground transmissions to inter-spacecraft links. Optical communications involving moving parties, especially at extra-long distances, require precise beam pointing and mutual tracking of communicating transceivers. The design concept and preliminary test results of a free-space communicator incorporating novel nonlinear optical tracking subsystem are presented. The development goal is to demonstrate a cost-effective terminal for Gbps optical links at a distance of up to 5 km. The tracking system consists of three subsystems: the coarse tracker (a 10.5 cm-diameter motorized Maksutov telescope); the electro-optical tracker (a voice-coil and a Si-based position detector); and the nonlinear optical fine tracker (a nonlinear cell with an IR-sensitive liquid crystal). Three-stage tracking allows for link budget improvement and maintaining a microradian pointing precision.

Free-space optical communication has emerged as a competitive and viable technology for offering high data rates, improved capacity, cost-effective and an easy to deploy solution for providing connectivity between two points which are up to a few kilometers apart. In this paper we present experimental work which demonstrates the practicality of next generation free-space optical (FSO) communication systems suitable for short-haul, high-speed and robust data links. This experimental system is placed between two buildings in the Waseda University campus area for a communication link spanning a distance of 1 km. We outline the design of the optical antenna which uses 1550 nm wavelength and directly coupling a freespace optical beam to a single-mode fiber without the need for OE/EO conversion, to offer a communication link with data rates from 2.5 Gbps to 10 Gbps. The antenna is capable of overcoming most common limitations inherent in FSO communication systems, such as atmospheric induced beam wander and scintillation effects. A high-speed tracking mechanism which utilizes a fine positioning mirror (FPM) capable of tracking and controlling the received beam and focusing/steering most of beam power into the fiber is presented. This FPM is capable of suppressing the frequent power fluctuations caused by beam angle-of-arrival (AOA) variations. This paper presents experimental results of the FSO communication system capable offering stable performance in terms of measured bit-error-rate (BER). Performance results showing increasing the systems data rate from 2.5 Gbps to 10 Gpbs are also presented.

In digital communications, as an alternative to conventional time domain equalization (TEQ), frequency domain equalization (FEQ) has been of interest, in particular for OFDM. In any optical channels, such as in fiber optic transmission or free-space optical communications (FSO), there can be channel dispersion, causing intersymbol interference (ISI). One feasible solution to this is FEQ of the distorted light signal by established theory of equalization. A new idea is presented that examines possibility of adaptive optical frequency-domain pulse shaping and equalization to remedy the optical channel dispersion problem in the light spectral domain.

In the current national scene, many actions point at projects of digital inclusion and citizenship. In this context, providing access technologies as a requisite for the implementation of these actions is primordial. In this way, many innovative experiences have been presented in the past few years. This paper presents a study on the Powerline Communication- PLC technology; as a proposal for a feasible access network for Brazilian Amazon. First, the characteristics of the PLC technology are studied from an implanted indoor prototype at Federal University of Para. The measures used in this prototype serve as input for a created model, from which it is intended to study the system more widely, considering factors such as: scalability, reliability and the physical characteristics.

Next generation wireless networks need to support broadband wireless services at significantly reduced cost. The existing wireless systems can hardly provide transmission capacity of the order of few Mbps. However, millimeter waves and optical fiber can provide data capacity of the order of Mbps and Tbps respectively. Hence the requirements of broadband wireless system can be achieved through the integration of optical fiber and millimeter wireless systems. We suggest modified millimeter wireless system, with optical fiber as feeder network. Simulations have been carried out for AWGN and optical fiber channels using MATLAB code, so as to compare their individual performance. When compared it is observed that the performance of MMOF link even for distance of 80 KM is better than that of the AWGN channel with SNR of 50 dB and above. Hence, an integrated fiber radio network is an excellent cost effective media for higher data rate (>100Mbps).

Access control based on RBAC makes the system suitable to the security strategy for special application, relieves burden of system administrators and can adapt itself to the adjustment of the system structure flexibly. But all the existing security mechanisms of the middleware technology can't support the RBAC model very well. The method using J2EE security mechanisms to support RBAC is showed in this paper. First, the configuration of J2EE security systems is given in the paper and the algorithm of J2EE authorization decision is designed. Then, the language of J2EE security description is used to define RBAC, and realization of the requirement of J2EE security service is given. It has achieved the anticipative effect in virtue of deployment and application on the platform of the national science technology infrastructure.

In order to qualify a subscriber loops for xDSL transmission, basic parameters like transfer function, scattering parameter S11 and characteristic impedance should be known. The aim of this paper is to present a test methodology for measurements of these basic parameters. The characteristic impedance is measured by open/short method and it is compared with the terminated measurement method defined in IEC (International Electrotechnical Commission) 611156-1. Transfer function and scattering parameter S11 of DSL loop are also measured on a real cable. The methodology is based on measurements of a 0.4 mm, 10 pairs, balanced twisted-pair cable of 1400 m of length. In order to improve the analysis of results, we compared the measurements from real cable with results from wireline simulators. The measurement of parameters of xDSL copper loop is done in an infrastructure set up in the LABIT (Technological Innovation in Telecommunications Lab) at UFPA (Federal University of Para), that consist of a wireline simulators, a precision impedance analyzer, and a network analyzer. The results show a difference between the measurements performed with real cables and wireline simulators for transfer function parameter. Characteristic impedance obtained by both methods presented quite similar results.

This paper presents methodologies that could be used for characterizing subscriber telephone loops that carry DSL services (ADSL and ADSL2+), by determination and analysis of frequency response, time domain reflectometry, and impulse response of the line. From this analysis, the subscriber loop length, identification and location of impairments such as bridged taps, gauge changes, and open ended termination across the line are carried out. To verify the methodologies presented, results obtained from measurements are drawn and compared to results obtained from computational simulations.

Due to the excessive amount of security threats, the need of a firewall is felt. Again, this firewall also acts as a proxy server to talk to the Internet. Any internal network can be masqueraded against the external world through this firewall. In case of different TCP/IP services like smtp, snmp, udp, tcp, http, and https, it can be restricted userwise. This firewall uses the Squid.conf configuration file as well as PAM (Password Authentication Module), the html files and other configuration files of the Linux operating system. The web browser used is Mozilla. Some CGI/PERL scripts are used. Different Intranet services are also provided userwise and mentioned in the squid.conf file. The major finding in this paper is the simplified way to create a security firewall.

Resilient Packet Ring (RPR) is a more promising solution to the bottleneck of metropolitan-area networks (MANs). The ring network architecture and associated protocol has been standardized by the IEEE 802.17 working group in 2004. To achieve high bandwidth utilization, optimum spatial reuse and fairness simultaneously, a policy of fair bandwidth assignment must be implemented in current RPR network. The existing fairness mechanisms suffer from severe oscillations under certain conditions, such as unbalanced traffic scenario and noticeable time delay. With our proposed fairness algorithm, the system performance of the three-node unbalanced traffic scenario, where the traffic loads are fixed, can be sustained by simply adjusting the compensating factor with respect to the time delay. In this paper, the time delay is constant, we investigate how this compensating factor should be adjusted with respect to the degree of unbalance. Furthermore, we study a four-node scenario, each node-to-node pair has different time-delay as well as unbalance degree. The simulation results show that the system performance remains excellent with the guidelines summarized.