Search results

1 – 10 of over 10000
Article
Publication date: 1 August 2004

Mounir A. Khalil

Wireless LANs (WLAN) offer network flexibility and end‐user mobility, making them one of the hottest technologies today. They have great impact on individuals and organizations…

1711

Abstract

Wireless LANs (WLAN) offer network flexibility and end‐user mobility, making them one of the hottest technologies today. They have great impact on individuals and organizations. Now people can use wireless networks in every application where recent findings indicate that growth in WLAN market continues to be driven by the corporate and educational sectors, where the desire to increase productivity and the benefit of enhanced mobility and learning outcomes continue to fuel demand. A questionnaire was developed to survey the behavior of end‐users, especially students and faculty, in using wireless laptops in accessing information from the Internet, digital libraries and many electronic sources in their education and research. The paper presents the advantages and disadvantages of using wireless network laptops as well as barriers for not using them in Higher Education. Special new update on wireless network security will be included. Guidelines for implementing wireless laptops in higher education are discussed.

Details

Library Hi Tech News, vol. 21 no. 7
Type: Research Article
ISSN: 0741-9058

Keywords

Article
Publication date: 13 October 2021

Zhifang Wang, Jianguo Yu, Shangjing Lin, Junguo Dong and Zheng Yu

The paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, this paper aims to propose a distributed robust H adaptive…

169

Abstract

Purpose

The paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, this paper aims to propose a distributed robust H adaptive fault-tolerant control algorithm suitable for the system to distribute to solve the problem of control and communication failure at the same time.

Design/methodology/approach

In the paper, the authors propose a distributed robust H adaptive fault-tolerant control algorithm suitable for the air-ground integrated wireless ad hoc network-integrated system.

Findings

The results show that the integrated system has good robustness and fault tolerance performance indicators for flight control and wireless signal transmission when confronted with external disturbances, internal actuator failures and wireless network associated failures and the flight control curve of the quadrotor unmanned aerial vehicle (UAV) is generally smooth and stable, even if it encounters external disturbances and actuator failures, its fault tolerance performance is very good. Then in the range of 400–800 m wireless communication distance, the success rate of wireless signal loop transmission is stable at 80%–100% and the performance is at least relatively improved by 158.823%.

Originality/value

This paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, based on the robust fault-tolerant control algorithm, the authors propose a distributed robust H adaptive fault-tolerant control algorithm suitable for the system and through the Riccati equation and linear matrix inequation method, the designed distributed robust H adaptive fault-tolerant controller further optimizes the fault suppression factor γ, so as to break through the limitation of only one Lyapunov matrix for different fault modes to distribute to solve the problem of control and communication failure at the same time.

Article
Publication date: 1 April 2000

Technology Task Group 3

Addresses the current state of the art of wireless technologies and infrastructures, projects where the field will be in the next decade, and discusses some of the challenges that…

5173

Abstract

Addresses the current state of the art of wireless technologies and infrastructures, projects where the field will be in the next decade, and discusses some of the challenges that must be met. Elaborates on the established major areas of commercial wireless access technology in the USA, ranked by deployment extent, which are: terrestrial mobile wireless access; terrestrial broadband wireless access; and mobile satellite service.

Details

info, vol. 2 no. 2
Type: Research Article
ISSN: 1463-6697

Keywords

Article
Publication date: 20 September 2023

Zhifang Wang, Quanzhen Huang and Jianguo Yu

In this paper, the authors take an amorphous flattened air-ground wireless self-assembling network system as the research object and focus on solving the wireless self-assembling…

Abstract

Purpose

In this paper, the authors take an amorphous flattened air-ground wireless self-assembling network system as the research object and focus on solving the wireless self-assembling network topology instability problem caused by unknown control communication faults during the operation of this system.

Design/methodology/approach

In the paper, the authors propose a neural network-based direct robust adaptive non-fragile fault-tolerant control algorithm suitable for the air-ground integrated wireless ad hoc network integrated system.

Findings

The simulation results show that the system eventually tends to be asymptotically stable, and the estimation error asymptotically tends to zero with the feedback adjustment of the designed controller. The system as a whole has good fault tolerance performance and autonomous learning approximation performance. The experimental results show that the wireless self-assembled network topology has good stability performance and can change flexibly and adaptively with scene changes. The stability performance of the wireless self-assembled network topology is improved by 66.7% at maximum.

Research limitations/implications

The research results may lack generalisability because of the chosen research approach. Therefore, researchers are encouraged to test the proposed propositions further.

Originality/value

This paper designs a direct, robust, non-fragile adaptive neural network fault-tolerant controller based on the Lyapunov stability principle and neural network learning capability. By directly optimizing the feedback matrix K to approximate the robust fault-tolerant correction factor, the neural network adaptive adjustment factor enables the system as a whole to resist unknown control and communication failures during operation, thus achieving the goal of stable wireless self-assembled network topology.

Article
Publication date: 1 July 2004

Bouchaib Bahli and Younes Benslimane

Wireless computing, as a way of providing mobile services, has been growing steadily during the past few years. While wireless communications offer organizations and users many…

3512

Abstract

Wireless computing, as a way of providing mobile services, has been growing steadily during the past few years. While wireless communications offer organizations and users many benefits such as portability, flexibility, increased productivity, and lower installation costs; on the other hand, risks inherent and exacerbated by wireless connectivity are widely reported, wherein networks are open to intruders who may cause unwanted consequences to an organization's information resources. Hence, understanding these risks will help protect against unforeseen threats, delays and costs. This paper aims at the development of a taxonomy for wireless computing risks. Six levels are identified including risks associated with the users, mobile devices, wireless networks, wireless applications, the Internet and the corporate gateway. The findings show that there is a need for systematic studies on wireless risk assessment and management. The implications of these findings for both researchers and practitioners are discussed.

Details

Information Management & Computer Security, vol. 12 no. 3
Type: Research Article
ISSN: 0968-5227

Keywords

Article
Publication date: 31 December 2007

Eric Hsiao‐Kuang Wu and Yu‐Chen Cheng

Emerging real‐time multimedia services over IP have penetrated into the daily lives of normal people with the advent of advanced broadband communications and innovated…

Abstract

Purpose

Emerging real‐time multimedia services over IP have penetrated into the daily lives of normal people with the advent of advanced broadband communications and innovated interconnection technologies. To protect shared Internet from unfairness and further congestion collapse, rate control plays a crucial role for many multimedia services such as streaming applications. Streaming applications such as video on demand (VoD) or voice over IP (VoIP) services face some critical problems such as insufficient bandwidth and improper performance of transmission protocols. Besides, the new generation networks are anticipated to integrate all heterogeneous wired and wireless networks and offer seamless customized multimedia services anywhere, anytime. However, wireless networks usually with low and variable bandwidth, and non‐congestion related loss do bring the challenge to the existing transport protocol, such as TCP, TFRC etc.

Design/methodology/approach

The paper uses simulations and compares other methods. The purpose of this paper is to address these issues. The paper, proposes a rate control scheme named Jitter‐based Rate Control (JRC) to fit wired‐wireless hybrid network which has better performance than the current rate control scheme.

Findings

Extensive simulations and comparisons with other methods verify the effectiveness of our method for accurate and smooth estimation, no matter whether the wireless links are located.

Originality/value

The paper introduces the JRC.

Details

International Journal of Pervasive Computing and Communications, vol. 3 no. 3
Type: Research Article
ISSN: 1742-7371

Keywords

Article
Publication date: 7 November 2008

Karri Huhtanen, Heikki Vatiainen, Sami Keski‐Kasari and Jarmo Harju

eduroam™ has already been proved to be a scalable, secure and feasible way for universities and research institutions to connect their wireless networks into a WLAN roaming…

Abstract

Purpose

eduroam™ has already been proved to be a scalable, secure and feasible way for universities and research institutions to connect their wireless networks into a WLAN roaming community, but the advantages of eduroam™ have not yet been fully discovered in the wireless community networks aimed at regular consumers. This aim of this paper is to describe how eduroam™ architecture and technologies can be utilised in building these kinds of wireless community networks and to present the experiences gathered in building the Wireless Tampere community network.

Design/methodology/approach

The eduroam™ architecture and technologies were chosen as the basis of Wireless Tampere community network architecture because of their scalability and security. Deploying eduroam™ technologies and architecture to a wider user base both confirmed old and revealed new issues and solutions in improving the usability and the deployment effort of eduroam™ and similar technologies.

Findings

The eduroam™ technology and architecture can be utilised to build wireless community networks, but additional effort must be allocated in improving the usability and the ease of deployment when consumers, company and other regular users are involved. The improvements achieved would not have been developed if the concept and architecture had not been exposed to consumer and company users. The development of both the eduroam™ and Wireless Tampere concept requires deploying them to a wider audience and improving them iteratively utilising the existing solutions as the basis for new improvements.

Originality/value

The paper presents the issues and problems, which were confronted when applying eduroam™ technologies in building the Wireless Tampere community network. The solutions found and deployment experiences presented can be utilised in improving eduroam™ as well as a basis for developing new, open and inter‐connected wireless community networks.

Details

Campus-Wide Information Systems, vol. 25 no. 5
Type: Research Article
ISSN: 1065-0741

Keywords

Article
Publication date: 3 January 2022

Zhifang Wang, Jianguo Yu and Shangjing Lin

To solve the above problems and ensure the stability of the ad hoc network node topology in the process of wireless signal transmission, this paper aims to design a robust…

Abstract

Purpose

To solve the above problems and ensure the stability of the ad hoc network node topology in the process of wireless signal transmission, this paper aims to design a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system.

Design/methodology/approach

This paper designs a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system.

Findings

The simulation results show that the amorphous flat wireless self-organizing network system has good nonlinear distortion fault-tolerant correction ability under the feedback control of the designed controller, and the system has the asymptotically stable convergence ability; the test results show: the node topology of the self-organizing network structural stability is significantly improved, which provides a foundation for the subsequent realization of long-distance transmission of ad hoc network nodes.

Research limitations/implications

Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further.

Originality/value

The controller can extract the fault information caused by nonlinear distortion in the wireless signal transmission process, and at the same time, its feedback matrix K can gradually converge the generated wireless signal error to zero, to realize the stable transmission of the wireless signal.

Article
Publication date: 12 February 2020

Peter Reji Ramanatt, K. Natarajan and K.R. Shobha

Aircraft manufacturers for a long time have been looking to reduce the weight of on board equipment to enhance performance both from commercial aspect and from military aspect…

Abstract

Purpose

Aircraft manufacturers for a long time have been looking to reduce the weight of on board equipment to enhance performance both from commercial aspect and from military aspect. The existing wired technology, using cables to connect different on board line replaceable unit apart from increasing the weight also increases the complexity related to electromagnetic interference, installation and maintenance. With continuous technology upgradation in the wireless domain, aviation industry is in the process of using wireless technology for intra-aircraft communication. Wireless technology can meet most of the challenges of modern avionics systems and significantly reduce the weight. This paper aims to look at various aspects of implementing a wireless network including issues related to wired network, aircraft channel, interference issues, suitable wireless protocols for aircraft applications and security aspects.

Design/methodology/approach

The paper has relied on literature study on wireless avionics intra-communications (WAIC) and the research work carried out in specific areas related to channel inside an aircraft, interference issues of wireless systems with onboard and external systems operating in the same band and security issues related to wireless network and security requirements of implementing an avionics wireless network (AWN). To identify suitable wireless protocol for AWN literature review and simulation to compare different protocols was carried out.

Findings

A single wireless protocol may not be suitable for all aircraft systems, and therefore, there may be a requirement to use multiple technologies. Mutual interference is not expected between WAIC systems with on board and external systems operating in the same band. The channel inside an aircraft is expected to be Rician (LOS) or Rayleigh (NLOS). However, additional measurements may have to be undertaken to have a generalized channel model. Security aspects in an AWN are critical and needs to be analyzed in detail prior to any wireless deployment.

Practical implications

Implementation of wireless technology can pave the way for usage of wireless technology for future generation avionics. With International Telecommunication Union allotting dedicated band for WAIC operations, considerable amount of research has been initiated in this field. It is believed that in the coming 2-3 years, the designers will be ready to replace the existing data wires with wireless transceivers. With radio technical commission for aeronautics and EURACAE involved in development of minimum operations performance standards for WAIC systems use of wireless for intra communication is bound to happen. Therefore, it is necessary to look at different issues for integrating wireless in the avionics domain.

Originality/value

The existing studies have been carried out in individual domains of using wireless in avionics. Separate studies and research work has been carried out for identifying wireless protocols, aircraft channel models, interference issues and security aspects. The paper has attempted to look at all these aspects together including certification.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 12 October 2018

David Espinoza and David Reed

This paper aims to compare the costs of deploying different wireless terrestrial broadband technologies in the Andes and Amazon Regions of Peru. These areas are representatives of…

Abstract

Purpose

This paper aims to compare the costs of deploying different wireless terrestrial broadband technologies in the Andes and Amazon Regions of Peru. These areas are representatives of different and challenging geographic regions throughout the globe that currently are severely underserved or unserved for vital broadband services necessary to bridge the “Digital Divide”.

Design/methodology/approach

The broadband technologies studied include Wi-Fi, Worldwide Interoperability for Microwave Access (WiMAX), long term evolution (LTE), TVWS and new stratospheric platforms (super-pressure balloons). This study conducts a technical analysis (design and simulation) of wireless broadband networks, and a bottom-up engineering cost analysis to estimate and compare the deployment and operating costs of the networks over a 10-year period. The analysis also identifies potential regulatory barriers to deployment associated with spectrum allocation licenses and overbooking requirements intended to improve quality of service.

Findings

Comparison of the capital and operating expenses of these options over a 10-year period finds that LTE and Wi-Fi can be the lowest cost alternatives, though significantly, stratospheric balloons have the lowest initial costs for the first few years and can factor as a low-cost broadband catalyst early in deployment. Finally, the lowest cost technology broadband roadmap for the 10-year period is presented, which includes using stratospheric balloons (carrying micro-LTE base stations) for the first years and deploying complementary terrestrial LTE networks for the rest of the 10-year period.

Originality/value

This study presents detailed technical and engineering cost analysis results of wireless access network deployments, including advanced wireless technologies and new unmanned aerial systems, to expand broadband services to rural areas in mountainous (Andes Region) and rainforest (Amazon Region) geographies to reduce the digital divide in emerging countries. Results aim to aid governments, regulators, internet service providers (incumbents and competitive) and content providers to assess current alternatives to expand broadband service in these rural areas.

Details

Digital Policy, Regulation and Governance, vol. 20 no. 5
Type: Research Article
ISSN: 2398-5038

Keywords

1 – 10 of over 10000