Provide Broadband Internet Access Research Articles

Antenna Systems with Wide-Angle Mechanoelectrical Beam Steering

Introduction. The active development of satellite communication networks determines the need for new antenna systems for ground terminals. The Sphere Federal program implies the commissioning of new satellite constellations for communication and remote sensing of the Earth. The Skif (providing broadband Internet access) and Express-RV (providing the Internet and communications for Arctic) satellite constellations are not geostationary, thus requiring constant satellite tracking even for stationary terminals. Deflecting structures operating on the principle of quasi-optical beam control make it possible to develop scanning antenna systems for organizing continuous satellite communications. Aim. Investigation of various types of dielectric structures for radiation pattern deflection and scanning antenna systems on their basis, as well as identification of a configuration with improved characteristics compared to the ideal structure in the shape of a dielectric wedge. Materials and methods. Mathematical modeling, electrodynamic modeling using CAD by the finite element method and the finite integration method, as well as an experimental study of an antenna system prototype in an anechoicchamber by measuring methods in the far-field and near-field of the antenna. Results. Electrodynamic simulation was carried out for three types of dielectric structures, analogues of a dielectric wedge, including a structure assembled from various dielectrics of fixed sizes with different dielectric constants; a structure of triangular dielectric plates; and a perforated dielectric structure. In addition, scanning antenna systems based on the presented configurations were analyzed. Radiation patterns were obtained for all structural types for various rotation angles of the deflecting systems. The structure assembled from various dielectrics of fixed sizes with different dielectric constants was found to possess the most optimal characteristics. This structure was used to develop a model for experimental confirmation of the conducted electrodynamic simulation. The maximum tilt angle of the radiation pattern was about 60°, the decrease in the directivity relative to the maximum value was 6 dB; for tilt angles up to 55°, the directivity degradation did not exceed 4 dB, the level of the side lobes did not exceed –12 dB (calculated) and –14 dB (measured). Conclusion. The results of studies into various types of structures for quasi-optical beam control of the radiation pattern show the possibility of using these configurations when creating low-profile antenna systems with wide-angle mechanoelectric scanning for organizing satellite communications for both mobile and stationary consumers using medium earth orbit spacecrafts.

High-Speed Trains Access Connectivity Through RIS-Assisted FSO Communications

Free-space optic (FSO) is a promising solution to provide broadband Internet access for high-speed trains (HSTs). Besides, reconfigurable intelligent surfaces (RIS) are considered as hardware technology to improve performance of optical wireless communication systems. In this paper, we propose a RIS-assisted FSO system to provide access connectivity for HTSs, as an upgrade for the existing direct and relay-assisted FSO access setups. Our motivation is mainly based on well-proven results indicating that a RIS-assisted optical wireless system, with a large enough number of RIS elements, outperforms a relay-assisted one thanks to its programmable structure. We firstly compute the statistical expressions of the considered RIS-assisted FSO channels under weak and moderate-to-strong fading conditions. Then, the network's average signal-to-noise ratio and outage probability are formulated based on the assumed fading conditions, and for two fixed- and dynamic-oriented RIS coverage scenarios. Our results reveal that the proposed access network offers up to around 44% higher data rates and 240% wider coverage area for each FSO base station (FSO-BS) compared to those of the relay-assisted one. The increase of coverage area, on average, reduces 67% the number of required FSO-BSs for a given distance, which results in fewer handover processes compared to the alternative setups. Finally, the results are verified through Monte-Carlo simulations.

Вопросы радиочастотного обеспечения космических систем на основемногоспутниковых группировок с учетом требований МСЭ-R и результатов ВКР-19

Deployment of space systems based on multi-satellite constellations to provide broadband Internet access and communication services acutely raises the question of their radio frequency support including issues of electromagnetic compatibility (EMC) between competing space systems using multi-satellite constellations (StarLink, OneWeb, Kuiper, etc.), their EMC with traditional space systems (satellite communication systems that employ spacecraft in geostationary and non-geostationary orbits, space systems of other services), as well as regulatory issues of entering into service and staged deployment of space systems. The article formulates the problematic issues of radio frequency support of modern space systems taking into account the trends of satellite constellations deployment and proposes the solutions with consideration to international and national requirements in the regulation of radio frequency spectrum including the ITU requirements and the requirements of Russian State Commission for Radio Frequencies. The paper shows the ways to share the radio frequency spectrum to meet new requirements of the World Radiocommunication Conference 2019 (WRC-19).

A Review on Future Security Challenges in 5G

The 5th Generation Mobile Technology will provide broadband internet access anywhere enabling users to connect with multiple devices on the go with Internet of Things (IoT). Technological enablers such as fog and cloud computing with Software defined Networking and Network function Virtualization. With the evolution from 4G to 5G there are many security challenges to be investigated for growing demands of user privacy. In this paper we provide an overview of different cryptographic attacks that can take place inside a 5G mobile network. Furthermore, we present the countermeasures for all the possible attacks and analyze future security challenges.

Prospects for the Development of Global Satellite Communication Constellations in the Context of New Services in the Telecommunications Market

A technique for assessing the market of advanced global telecommunication networks, including the space segment, as global coverage communication megaconstellations is considered. According to our results, the worldwide traffic consumption by 5G mobile devices by 2022 will be almost 8.5 EB/month. The possible cost of deploying a megaconstellation of communications to provide broadband Internet access at any place in the world can range from $5 to $50 billion, depending on service requirements. We have shown that modern and prospective space communications constellations can be integrated into a new-generation global telecommunication infrastructure. Deployment of a constellation of 600 or more devices with a cost of almost $10 billion can provide traffic transit from base stations in remote areas delivering the population with broadband Internet through 5G networks.

LoPoFly: Location and Positioning Optimization for Flying Networks

In areas that demand short-term Internet connectivity, like events and mobile offices, it is not feasible to have a permanent wireless Internet infrastructure. To provide broadband Internet access to temporary clients, we propose the use of flying networks. These networks need to be carefully managed, mainly due to the limitation on their nodes’ battery capacity. Considering these issues, we introduce a new Location and Positioning Optimization Technique for Flying Networks (LoPoFly). LoPoFly includes two modules: (i) location that uses the Deterministic Annealing (DA) metaheuristic to find a location where a flying node is required based on client distribution and (ii) positioning that manages relocation and exchange of flying nodes. To the best of our knowledge, this is the first approach that employs the DA metaheuristic to manage the flying networks covering restrictions related to energy, replacement, communication, and mobility together. Through simulations, we analyze the performance of LoPoFly in two different mobility scenarios. The results show that in both scenarios, LoPoFly mitigates the number of required flying nodes, even serving a higher number of clients.

Trends Towards Multi-Radio and Multi-Channel based Wireless Mesh Networks

This paper is a review on QoS issue of wireless mesh networks. QoS comes up with a great collection of networking technologies and procedures that guarantees the capability of a network to deliver with predictable consequences. WMNs have emerged as a flexible, reliable and cost effective way of providing broadband internet access over wide areas through multi hop communication. This paper has reviewed different routing protocols used in the WMNs. The overall objective of this paper is to explore the various short comings of the routing protocols of WMNs.

Design of Multicarrier Broadband Power Line Communication System for Tanzania Homes

Broadband Power Line Communication (BPLC) is a method of providing broadband internet access to consumers using High Frequency (HF) radio signals coupled into the mains power wiring. In the BPLC system, data signals are modulated at HF and injected into the power lines using broadband modulation techniques. Design of a BPLC system requires a complete understanding of the Power line network (PLN) topologies involved. PLN can be classified as Indoor or In-home, Low voltage, Medium voltage and High voltage respectively. In this study four maps representing typical Tanzania houses were selected randomly, and then four indoor power-line networks were derived from their circuit diagrams. The Impulse response was estimated at the switch sockets using the recent power-line channel model by Anatory et al. The delay spread estimated from the impulse response was used to design the OFDM system and the OFDM system performance was evaluated. General Terms Indoor Power Line Communications, Anatory et. al.

QoS in Wireless Mesh Networks- A Review

This paper is a review on QoS issue of Wireless mesh networks. QoS comes up with a great collection of networking technologies and procedures that guarantees the capability of a network to deliver with predictable consequences. WMNs have emerged as a flexible, reliable and cost effective way of providing broadband internet access over wide areas through multi hop communication. This paper has reviewed different routing protocols used in the WMNs. The overall objective of this paper is to explore the various short comings of the routing protocols of WMN.

Adjusting the TCP Sending Rate and Retransmissions after Retransmission Timeouts Based on One-Way Queuing Delay in Wireless Mesh Network

Wireless Mesh Network (WMN) is regarded as a viable solution to provide broadband Internet access flexibly and cost efficiently. Improving the performance of Transmission Control Protocol (TCP) in WMNs is an active research area in the networking community. The existing solutions proposed for improving the TCP performance has concentrated on differentiating the DATA packet drops in the forward direction induced by both network congestion as well as transmission errors. However, the recent studies show that in WMNs packet drops occur not only in the forward direction but also in the reverse direction particularly due to hidden terminal, hidden capture terminal, link asymmetry etc. The loss of ACK packets in the reverse direction cause frequent retransmission timeouts subject to needless retransmissions and unnecessary slowing down the growth of congestion window, which causes the performance degradation of TCP. In this paper, we introduce a sender side TCP algorithm, called detection of packet loss (DPL), which is capable to distinguish the type of packet drops either DATA or ACKs caused by transmission errors as well as network congestion based on one-way queuing delay and react accordingly. To justify our contributions, we implement DPL in Qualnet simulator and compare its performance against existing TCP solutions via extensive simulations. Our simulation results show that the proposed algorithm can accurately distinguish the type of packet drops whether it is a DATA or ACK caused by transmission error or congestion and can significantly improve the performance under a wide range of scenarios in WMNs.

Clustering based Load Balanced Gateway Placement Approach

Wireless mesh networks (WMN) is a promising technology to provide broadband Internet access. Gateway placement is an important part of WMN design that determines how to place the gateways in WMN. Various approaches have been given by various researchers for Gateway placement taking care of various parameters. In this paper, we proposed a clustering based load balanced algorithm to find an approximating optimal solution of gateway placement in WMN. The aim of our research is to focus on load balanced gateway placement problem.

New combined WiMAX/DSRC infrastructure design for efficient vehicular networking

Abstract In this article, a new infrastructure of a combined Worldwide Interoperability for Microwave Access (WiMAX) and Dedicated Short-Range Communications (DSRC) link layer is proposed with the purpose of reducing simultaneous WiMAX connections. WiMAX offers wide area connectivity of vehicles to ground-based base stations, while DSRC offers relatively shorter communication that allows for vehicles in proximity of each other to communicate directly. The proposed design uses the fact that WiMAX amendments support the concept of a WiMAX relay node, and substitutes the WiMAX relay nodes with nodes that are capable of both WiMAX and DSRC communications. This change allows for the number of WiMAX connections to be concentrated while supporting more subscribing users via WiMAX tunnelled over DSRC relay. The focus of this design is on the use case of providing broadband Internet access to a large number of DSRC capable vehicles in a WiMAX served region. The design uses DSRC as a WiMAX tunnel, but with changes to the WiMAX protocol, specifically network entry and handover processes are redesigned to have different behaviour only when operating over DSRC. Network entry over DSRC modifications are described and illustrated with comparison to existing WiMAX standards. Handover process facilitated over both WiMAX and DSRC layers are described, illustrated and are also standard compliant. Unified modeling language is used to assist with the explanations of the components to improve understanding of the design in relation to existing WiMAX standards. In addition to standard WiMAX operability, the design can also support WiMAX data subscription using a software-defined WiMAX radio via DSRC relay connectivity. This proposed design improves WiMAX communication by reducing the number of WiMAX connections between vehicles. We plotted the throughput of various cluster sizes of WiMAX only mobile relay, versus our proposed DSRC-enabled WiMAX mobile relay in order to show the efficiency benefit of our design. We also provide a simulated curve of percentage improvement efficiency for varying amount of active users. We show that as the total number of users in the system increases, our proposed system significantly improves the overall system efficiency, especially in heavily congested traffic.

Energy-Efficient Mobile Data Uploading from High-Speed Trains

Recent decades have witnessed the fast development of high-speed railway systems in many countries, which have significantly shortened the travel time between distant cities. Accompanied with this convenience is the challenge for cell phone vendors to provide broadband Internet access for passengers, particularly considering the fast changing channel conditions in high-speed trains and the limited battery of cell phones, which often cannot be re-charged in trains. In this paper, inspired by the unique spatial-temporal characteristics of wireless signals along high-speed railways, we propose a novel energy-efficient scheduling approach for uploading data from cell phones, both with soft deadlines (e.g., documents) and hard deadlines (e.g., video streaming). Our solution effectively predicts the signal strength through its spatial-temporal periodicity in this new application scenario, and smartly adjusts the transmission rate to maximize the overall data transmission rate and yet conserves the energy consumption. Performance evaluation based on realistic railway scenarios and H.264 video traces demonstrate the effectiveness of our solution and its superiority as compared to the existing solutions.

PEACE: A Novel Privacy-Enhanced Yet Accountable Security Framework for Metropolitan Wireless Mesh Networks

Recently, multihop wireless mesh networks (WMNs) have attracted increasing attention and deployment as a low-cost approach to provide broadband Internet access at metropolitan scale. Security and privacy issues are of most concern in pushing the success of WMNs for their wide deployment and for supporting service-oriented applications. Despite the necessity, limited security research has been conducted toward privacy preservation in WMNs. This motivates us to develop PEACE, a novel Privacy-Enhanced yet Accountable seCurity framEwork, tailored for WMNs. On one hand, PEACE enforces strict user access control to cope with both free riders and malicious users. On the other hand, PEACE offers sophisticated user privacy protection against both adversaries and various other network entities. PEACE is presented as a suite of authentication and key agreement protocols built upon our proposed short group signature variation. Our analysis shows that PEACE is resilient to a number of security and privacy related attacks. Additional techniques were also discussed to further enhance scheme efficiency.

A Survey on Methods for Broadband Internet Access on Trains

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.

How IMS Enables Converged Services for Cable and 3G Technologies: A Survey

The IP multimedia subsystem (IMS) is a service control overlay standardized by the 3GPP. The IMS is based on session initiation protocol (SIP) to establish, modify, and terminate the sessions. It provides a clean separation between services, signaling, and media with the potential to enable control and management of services over multiple transport technologies. In the scope of fixed-mobile convergence, this paper is dedicated to presenting a review of how cable networks can be integrated into IMS technology to achieve 3G-cable horizontal convergence. Cable networks, as one of the major fixed broadband access technologies with PacketCable architecture, are able to provide broadband internet access and VoIP in addition to cable TV. In this article, we review the evolution in PacketCable architecture to take up IMS. In this way, we consider the standardization and research activities to address this integration. We review some important challenges such as SIP protocol compatibility, defining unique user profile, required enhancement in authentication process, QoS and charging system.

Optimal placement and channel assignment of relay stations in heterogeneous wireless mesh networks by modified Bender’s decomposition

Fixed Broadband Wireless Access (FBWA) technology is designed to serve as a wireless DSL replacement to provide broadband Internet access in underserved areas where no other access technology exists. Due to the enormousness of the target service area, relay equipment play an important role in such networks, and the installation and maintenance cost of the network is directly proportional to the cost of the relay equipment. To minimize the network operational cost, an optimization framework which computes the minimum number of relay stations and their corresponding placements and channel assignments in the network is desired. Because the problem is NP-hard, we propose an efficient optimization algorithm based on a modified version of Bender’s decomposition to iteratively compute converging bounds to the problem solution. Our numerical results show that by using a few relay stations in a rural community, broadband Internet access can be established in a cost effective manner.

Mitigating the gateway bottleneck via transparent cooperative caching in wireless mesh networks

Wireless mesh networks (WMNs) are characterized by mesh routers connected by wireless links to each other and to a few gateway nodes. The most significant application of such networks is to provide broadband Internet access to static or mobile hosts in areas where wired infrastructure is difficult or economically infeasible to deploy. Since most WMN traffic flows through a few gateway nodes, this can cause significant congestion around the gateway.

Radio-over-fiber-based solution to provide broadband internet access to train passengers [Topics in Optical Communications

Nowadays, combining high-bandwidth connections (e.g., 5 Mb/s/user) and fast-moving users (e.g., on a train at 300 km/h) while keeping a sufficient level of QoS is still an unsolved bottleneck. In this article we propose a cellular trackside solution for providing broadband multimedia services to train passengers. A radio-over-fiber network in combination with moving cells forms the base of this realization

Internet Adoption Among Lecturers In Ghana\'s premier University, Expectations and Realities

The study investigated the use of the Internet amongst the academic staff of the University of Ghana. The survey technique was adopted for this study since a large number of people was involved in the study. Results showed that academic staff make use of educational databases, and the performance of searches in locating information. They also make use of electronic mail, the World Wide Web, companion lecturing websites, and professional article databases in conducting research and teaching. Electronic mail is the most commonly used tool in research whilst educational databases are the most commonly used tools in teaching. Recommendations for making the resource more available included providing broadband Internet access and the government promoting private sector investment. Article Type: Case Study Key words: Internet, University, Ghana, Lecturer The Information Technologist Vol.2(1) 2005: 1-14