10,295 research outputs found

    Wireless Networking to Support Data and Voice Communication Using Spread Spectrum Technology in The Physical Layer

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    Wireless networking is rapidly growing and becomes an inexpensive technology which allows multiple users to simultaneously access the network and the internet while roaming about the campus. In the present work, the software development of a wireless LAN(WLAN) is highlighted. This WLAN utilizes direct sequence spread spectrum (DSSS) technology at 902MHz RF carrier frequency in its physical layer. Cost effective installation and antijaming property of spread spectrum technology are the major advantages of this work.Comment: international conference on information technology, March 2007. 7 pages,4 figures, 2 table

    Wireless Lan to Support Multimedia Communication Using Spread Spectrum Technology

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    Wireless LAN is currently enjoying rapid deployment in University departments, business offices, hospitals and homes. It becomes an inexpensive technology and allows multiple numbers of the households to simultaneously access the internet while roaming about the house. In the present work, the design and development of a wireless LAN is highlighted which utilizes direct sequence spread spectrum (DSSS) technology at 900MHz RF carrier frequency in its physical layer. This provides enormous security in the physical layer and hence it is very difficult to hack or jam the network. The installation cost is also less due to the use of 900 MHz RF carrier frequency..Comment: URSI 0ctober 22-29 2005, 4pages, 6 figure

    Aeronautical Ad Hoc Networking for the Internet-Above-The-Clouds

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    The engineering vision of relying on the ``smart sky" for supporting air traffic and the ``Internet above the clouds" for in-flight entertainment has become imperative for the future aircraft industry. Aeronautical ad hoc Networking (AANET) constitutes a compelling concept for providing broadband communications above clouds by extending the coverage of Air-to-Ground (A2G) networks to oceanic and remote airspace via autonomous and self-configured wireless networking amongst commercial passenger airplanes. The AANET concept may be viewed as a new member of the family of Mobile ad hoc Networks (MANETs) in action above the clouds. However, AANETs have more dynamic topologies, larger and more variable geographical network size, stricter security requirements and more hostile transmission conditions. These specific characteristics lead to more grave challenges in aircraft mobility modeling, aeronautical channel modeling and interference mitigation as well as in network scheduling and routing. This paper provides an overview of AANET solutions by characterizing the associated scenarios, requirements and challenges. Explicitly, the research addressing the key techniques of AANETs, such as their mobility models, network scheduling and routing, security and interference are reviewed. Furthermore, we also identify the remaining challenges associated with developing AANETs and present their prospective solutions as well as open issues. The design framework of AANETs and the key technical issues are investigated along with some recent research results. Furthermore, a range of performance metrics optimized in designing AANETs and a number of representative multi-objective optimization algorithms are outlined

    Performance Analysis and Special Issues of Broadband Strategies in the Computer Communication

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    Broadband communications consists of the technologies and equipment required to deliver packet-based digital voice, video, and data services to end users. Broadband affords end users high-speed, always-on access to the Internet while affording service providers the ability to offer value-added services to increase revenues. Due to the growth of the Internet, there has been tremendous buildout of high-speed, inter-city communications links that connect population centers and Internet service providers (ISPs) points of presence (PoPs) around the world. This build out of the backbone infrastructure or core network has occurred primarily via optical transport technology. Broadband access technologies are being deployed to address the bandwidth bottleneck for the "last mile," the connection of homes and small businesses to this infrastructure. One important aspect of broadband access to the home is that it allows people to telecommute effectively by providing a similar environment as when they are physically present in their office: simultaneous telephone and computer access, high-speed Internet and intranet access for e-mail, file sharing, and access to corporate servers.Comment: 16 page

    Low Power Wide Area Networks: An Overview

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    Low Power Wide Area (LPWA) networks are attracting a lot of attention primarily because of their ability to offer affordable connectivity to the low-power devices distributed over very large geographical areas. In realizing the vision of the Internet of Things (IoT), LPWA technologies complement and sometimes supersede the conventional cellular and short range wireless technologies in performance for various emerging smart city and machine-to-machine (M2M) applications. This review paper presents the design goals and the techniques, which different LPWA technologies exploit to offer wide-area coverage to low-power devices at the expense of low data rates. We survey several emerging LPWA technologies and the standardization activities carried out by different standards development organizations (e.g., IEEE, IETF, 3GPP, ETSI) as well as the industrial consortia built around individual LPWA technologies (e.g., LORa Alliance,WEIGHTLESS-SIG, and DASH7 Alliance). We further note that LPWA technologies adopt similar approaches, thus sharing similar limitations and challenges. This paper expands on these research challenges and identifies potential directions to address them. While the proprietary LPWA technologies are already hitting the market with large nationwide roll-outs, this paper encourages an active engagement of the research community in solving problems that will shape the connectivity of tens of billions of devices in the next decade.Comment: \c{opyright} 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work

    HELPER: Heterogeneous Efficient Low Power Radio for Enabling Ad Hoc Emergency Public Safety Networks

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    Natural and man-made disasters have been causing destruction and distress to humanity all over the world. In these scenarios, communication infrastructures are the most affected entities making emergency response operations extremely challenging. This invokes a need to equip the affected people and the emergency responders with the ability to rapidly set up and use independent means of communication. Therefore, in this work, we present a complete end-to-end solution that can connect survivors of a disaster with each other and the authorities using a completely self-sufficient ad hoc network that can be setup rapidly. Accordingly, we develop a Heterogeneous Efficient Low Power Radio (HELPER) that acts as an access point for end-users to connect using custom website application. These HELPERs then coordinate with each other to form a LoRa based ad hoc network. To this end, we propose a novel cross-layer optimized distributed energy-efficient routing (SEEK) algorithm that aims to maximize the network lifetime. The HELPER is prototyped using WiFi enabled Raspberry Pi and LoRa module that is configured to run using Li-ion batteries. We implement the required cross-layer protocol stack along with the SEEK routing algorithm. We have conducted demonstrations to establish the feasibility of exchanging of text messages over the HELPER network, live map updates, ability to send distress messages to authorities. Emergency responders can leverage this technology to remotely monitor the connectivity of the affected area and alert users of imminent dangers. SEEK algorithm was shown to outperform a greedy geographical routing algorithm implemented on HELPER testbed by up to 53 % in terms of network lifetime and up to 28 % in terms of throughput. Overall, we hope this technology will become instrumental in improving the efficiency and effectiveness of public safety activities

    A Survey on High-Speed Railway Communications: A Radio Resource Management Perspective

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    High-speed railway (HSR) communications will become a key feature supported by intelligent transportation communication systems. The increasing demand for HSR communications leads to significant attention on the study of radio resource management (RRM), which enables efficient resource utilization and improved system performance. RRM design is a challenging problem due to heterogenous quality of service (QoS) requirements and dynamic characteristics of HSR wireless communications. The objective of this paper is to provide an overview on the key issues that arise in the RRM design for HSR wireless communications. A detailed description of HSR communication systems is first presented, followed by an introduction on HSR channel models and characteristics, which are vital to the cross-layer RRM design. Then we provide a literature survey on state-of-the-art RRM schemes for HSR wireless communications, with an in-depth discussion on various RRM aspects including admission control, mobility management, power control and resource allocation. Finally, this paper outlines the current challenges and open issues in the area of RRM design for HSR wireless communications.Comment: 40 pages, 10 figures. Submitted to Computer Communication

    Wi-Fi & WiMAX: A Comparative Study

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    Usually broadband wireless access networks are considered to be enterprise level networks providing us with more capacity as well as coverage. We have seen that in remote inaccessible areas wired networks are not at all cost effective. Wireless networking has offered us an alternative solution for such problem of information access. They have definitely changed the way people communicate and share information among themselves by overcoming problems nowadays associated with distance and location. This paper provides a comparison and technical analysis of alternatives for implementing last-mile wireless broadband services. It provides detailed technical differences between 802.11 (Wi-FI) wireless networks with 802.16 (WiMAX), a new technology that solves many of the difficulties in last-mile implementations.Comment: 5 pages, 4 figures, 1 tabl

    Towards combinatorial modeling of wireless technology generations

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    The paper addresses the following problems: (1) a brief survey on wireless mobile communication technologies including evolution, history evolution (e.g., chain of system generations 0G, 1G, 2G, 3G, 4G, 5G, 6G, 7G); (2) using a hierarchical structural modular approach to the generations of the wireless communication systems (i.e., hierarchical combinatorial modeling of the communication technologies), (3) illustrative usage of two-stage combinatorial approach to improvement/forecasting of the communication technology (a version of 5G) (on the basis of multiple choice problem). Numerical examples illustrate the suggested combinatorial approach.Comment: 20 pages, 13 figures, 9 table

    A Novel Solution to the Short Range Bluetooth Communication

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    Bluetooth is developed for short range communication. Bluetooth Devices are normally having low power and low cost. This is a wireless communication technology designed to connect phones, laptops and PDAs. The greater availability of portable devices with Bluetooth connectivity imposes wireless connection between enabled devices. On an average the range of Bluetooth devices is about 10 meters. The basic limitation of the Bluetooth communication is this range limitation. In this paper I have studied the limitations of Bluetooth communication and consider range constraint as the major limitation. I propose a new expanded Blue tooth network to overcome the range constraint of Bluetooth device. This creates a network of Bluetooth enabled devices that will include laptops, set top devices and also mobile phones. The main purpose of this proposal is to establish a network will enable the users to communicate outside the range without any range constraint.Comment: 10 pages; IJANS-2011 October Issu
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