19 resultados para Bluetooth wireless technology
em Aston University Research Archive
Resumo:
The existing literature has given little consideration to social values of information technology in general or of wireless technology in particular. The purpose of this paper is thus to shed new light on this issue. Based on an interpretive case study, we examine two healthcare organisations and discover that social values are often manifested beyond, as well as within, organisations. A matrix of social values in relation to technology changes and their interactions with various stakeholders is further discussed. The matrix helps understand how various social values emerge from and revolve around organisations’ strategic management of information technology. The implications of the findings about social values are discussed and future research directions are suggested.
Resumo:
This paper investigates and implicates how organisations renovate their service operations and improve business productivity in the context of wireless networks and mobile technologies. Drawing from two case studies conducted in healthcare institutions situated in southwest USA, the findings suggested that wireless networks and relevant technologies evidently enhanced business productivity and fundamentally changed service provision and, in turn, shaped or reshaped organisational images in the community. The implications reinforced the notions that technology could provide foundation for an organisation’s economic growth and that organisations’ business and IT strategies need to seriously consider aligning with this technological trend. For researchers, how organisations in different industries manoeuvre their ways around these technologies might provide interesting venues for future investigation.
Resumo:
Despite growing attention, social values, compared to economic aspects, of information technology (IT) capture substantially less attention in the mainstream IT literature. In the context of mobile technology, social values might be as critical to help justify technology investment as the predominant economics perspective in the existing IT literature. As wireless networks and relevant mobile technologies continue to penetrate the global society and business world, an emerging social phenomenon rapidly reshapes how organizations interact with the technology and reposition themselves in their specific institutional context where organizations often develop networked alliance to compete against one another. This study thus seeks to shed light on how organizations make sense of the social aspects of wireless network implementation. Preliminary understanding derived from two higher education organizations' experiences is summarized. Implications for future research endeavor are suggested.
Resumo:
Wireless Mesh Networks (WMNs) have emerged as a key technology for the next generation of wireless networking. Instead ofbeing another type of ad-hoc networking, WMNs diversify the capabilities of ad-hoc networks. There are many kinds of protocols that work over WMNs, such as IEEE 802.11a/b/g, 802.15 and 802.16. To bring about a high throughput under varying conditions, these protocols have to adapt their transmission rate. While transmission rate is a significant part, only a few algorithms such as Auto Rate Fallback (ARF) or Receiver Based Auto Rate (RBAR) have been published. In this paper we will show MAC, packet loss and physical layer conditions play important role for having good channel condition. Also we perform rate adaption along with multiple packet transmission for better throughput. By allowing for dynamically monitored, multiple packet transmission and adaptation to changes in channel quality by adjusting the packet transmission rates according to certain optimization criteria improvements in performance can be obtained. The proposed method is the detection of channel congestion by measuring the fluctuation of signal to the standard deviation of and the detection of packet loss before channel performance diminishes. We will show that the use of such techniques in WMN can significantly improve performance. The effectiveness of the proposed method is presented in an experimental wireless network testbed via packet-level simulation. Our simulation results show that regardless of the channel condition we were to improve the performance in the throughput.
Resumo:
Culture defines collective behavior and interactions among people in groups. In organizations, it shapes group identity, work pattern, communication schemes, and interpersonal relations. Any change in organizational culture will lead to changes in these elements of organizational factors, and vice versa. From a managerial standpoint, how to cultivate an organizational culture that would enhance these aforementioned elements in organizational workplace should thus be taken into serious consideration. Based on cases studies in two hospitals, this paper investigates how organizational culture is shaped by a particular type of information and communication technology, wireless networks, a topic that is generally overlooked by the mainstream research community, and in turn implicates how such cultural changes in organizations renovate their competitiveness in the marketplace. Lessons learned from these cases provide valuable insights to emerging IT management and culture studies in general and in wireless network management in the healthcare sector in particular.
Resumo:
Orthogonal frequency division multiplexing (OFDM) is becoming a fundamental technology in future generation wireless communications. Call admission control is an effective mechanism to guarantee resilient, efficient, and quality-of-service (QoS) services in wireless mobile networks. In this paper, we present several call admission control algorithms for OFDM-based wireless multiservice networks. Call connection requests are differentiated into narrow-band calls and wide-band calls. For either class of calls, the traffic process is characterized as batch arrival since each call may request multiple subcarriers to satisfy its QoS requirement. The batch size is a random variable following a probability mass function (PMF) with realistically maximum value. In addition, the service times for wide-band and narrow-band calls are different. Following this, we perform a tele-traffic queueing analysis for OFDM-based wireless multiservice networks. The formulae for the significant performance metrics call blocking probability and bandwidth utilization are developed. Numerical investigations are presented to demonstrate the interaction between key parameters and performance metrics. The performance tradeoff among different call admission control algorithms is discussed. Moreover, the analytical model has been validated by simulation. The methodology as well as the result provides an efficient tool for planning next-generation OFDM-based broadband wireless access systems.
Resumo:
Existing wireless systems are normally regulated by a fixed spectrum assignment strategy. This policy leads to an undesirable situation that some systems may only use the allocated spectrum to a limited extent while others have very serious spectrum insufficiency situation. Dynamic Spectrum Access (DSA) is emerging as a promising technology to address this issue such that the unused licensed spectrum can be opportunistically accessed by the unlicensed users. To enable DSA, the unlicensed user shall have the capability of detecting the unoccupied spectrum, controlling its spectrum access in an adaptive manner, and coexisting with other unlicensed users automatically. In this article, we propose a radio system Transmission Opportunity-based spectrum access control protocol with the aim to improve spectrum access fairness and ensure safe coexistence of multiple heterogeneous unlicensed radio systems. In the scheme, multiple radio systems will coexist and dynamically use available free spectrum without interfering with licensed users. Simulation is carried out to evaluate the performance of the proposed scheme with respect to spectrum utilisation, fairness and scalability. Comparing with the existed studies, our strategy is able to achieve higher scalability and controllability without degrading spectrum utilisation and fairness performance.
Resumo:
Wireless Mesh Networks (WMNs) have emerged as a key technology for the next generation of wireless networking. Instead of being another type of ad-hoc networking, WMNs diversify the capabilities of ad-hoc networks. Several protocols that work over WMNs include IEEE 802.11a/b/g, 802.15, 802.16 and LTE-Advanced. To bring about a high throughput under varying conditions, these protocols have to adapt their transmission rate. In this paper, we have proposed a scheme to improve channel conditions by performing rate adaptation along with multiple packet transmission using packet loss and physical layer condition. Dynamic monitoring, multiple packet transmission and adaptation to changes in channel quality by adjusting the packet transmission rates according to certain optimization criteria provided greater throughput. The key feature of the proposed method is the combination of the following two factors: 1) detection of intrinsic channel conditions by measuring the fluctuation of noise to signal ratio via the standard deviation, and 2) the detection of packet loss induced through congestion. We have shown that the use of such techniques in a WMN can significantly improve performance in terms of the packet sending rate. The effectiveness of the proposed method was demonstrated in a simulated wireless network testbed via packet-level simulation.
Resumo:
Wireless power transmission technology is gaining more and more attentions in city transportation applications due to its commensurate power level and efficiency with conductive power transfer means. In this paper, an inductively coupled wireless charging system for 48V light electric vehicle is proposed. The power stages of the system is evaluated and designed, including the high frequency inverter, the resonant network, full bridge rectifier, and the load matching converter. Small signal modeling and linear control technology is applied to the load matching converter for input voltage control, which effectively controls the wireless power flow. The prototype is built with a dsPIC digital signal controller; the experiments are carried out, and the results reveal nature performances of a series-series resonant inductive power charger in terms of frequency, air-gap length, power flow control, and efficiency issues.
Resumo:
IEEE 802.15.4 standard has been recently developed for low power wireless personal area networks. It can find many applications for smart grid, such as data collection, monitoring and control functions. The performance of 802.15.4 networks has been widely studied in the literature. However the main focus has been on the modeling throughput performance with frame collisions. In this paper we propose an analytic model which can model the impact of frame collisions as well as frame corruptions due to channel bit errors. With this model the frame length can be carefully selected to improve system performance. The analytic model can also be used to study the 802.15.4 networks with interference from other co-located networks, such as IEEE 802.11 and Bluetooth networks. © 2011 Springer-Verlag.
Resumo:
The existing body of knowledge has generally supported that organizational culture plays a significant role in shaping group identity, work pattern, communication schemes, and interpersonal relations; all of these cultural elements are important organizational factors that shape workplaces and operational routines. In the context of emerging information technology, it has also been suggested that organizational culture could affect IT implementation and management. However, little is known about how emerging information technology shapes organizational culture, which in turn helps reshape the organization as a whole. The purpose of this paper is thus to build empirical understanding of how IT in general and emerging wireless networks in particular reshapes organizational culture. Case studies conducted in two hospitals situated in southwest U.S.A. illustrated that the implementation of wireless networks indeed helped shape and/or reshape organizational culture in the healthcare sector and in turn enhance healthcare organizations’ competitiveness in the marketplace. For IT managers and practitioners in healthcare institutions, effective strategy to plan and manage emerging ITs such as wireless networks will thus have long-term implications on cultivating organizational culture that could eventually reshape workplace and competitiveness.
Resumo:
Cost efficiency has been a dominant perspective in the traditional IT literature. However, in complex technology and business environment, the widely recognized cost efficient assumption of information technology has been increasingly challenged. Drawing from a case study of wireless network implementation situated in a politically sensitive workplace, this paper provided practice insights for IT managers in today’s networked economy. More specifically, stories experienced in the case study illustrated that despite well-calculated cost efficiency of wireless network infrastructure, the radical implementation process in the case organization encountered enormous challenges and opposition due to the fact that administrators failed to consider various stakeholders’ positions and interests. Eventually, the implementation objectives and outcome were considerably undermined. Implications from this empirical case research reemphasized the significance of understanding political forces situated in any business environment where different stakeholders hold conflicting interests. Lessons learned from the case story further encouraged IT managers and policy makers to better strategize emerging information technology in general and wireless networks in particular as the whole global society and business environment are increasingly facing an emerging wireless world.
Resumo:
This paper analyzes a case study of wireless network implementation in a politically sensitive environment and seeks to gain practical insights for IT managers in today’s networked economy. The case evolved around an urgent decision to implement wireless networks that were a radical replacement for the existing wired network infrastructure. Although the wireless network infrastructure was well calculated as being considerably cost-efficient, inexperienced administrators and IT department failed to consult various involved stakeholders. Consequently, unintended results of wireless network implementation entangled with the cost efficiency of technology outcome and in turn undermined the objectives and achievement of the initial project plan. Drawing from social perspectives, this case study challenges traditionally dominant perspectives of technology efficiency and summarizes several lessons that could help IT managers and policy makers to better strategize ICT in general, and wireless networks in particular.
Resumo:
In this paper, we study the management and control of service differentiation and guarantee based on enhanced distributed function coordination (EDCF) in IEEE 802.11e wireless LANs. Backoff-based priority schemes are the major mechanism for Quality of Service (QoS) provisioning in EDCF. However, control and management of the backoff-based priority scheme are still challenging problems. We have analysed the impacts of backoff and Inter-frame Space (IFS) parameters of EDCF on saturation throughput and service differentiation. A centralised QoS management and control scheme is proposed. The configuration of backoff parameters and admission control are studied in the management scheme. The special role of access point (AP) and the impact of traffic load are also considered in the scheme. The backoff parameters are adaptively re-configured to increase the levels of bandwidth guarantee and fairness on sharing bandwidth. The proposed management scheme is evaluated by OPNET. Simulation results show the effectiveness of the analytical model based admission control scheme. ©2005 IEEE.