2,405 research outputs found
Cellular Underwater Wireless Optical CDMA Network: Potentials and Challenges
Underwater wireless optical communications is an emerging solution to the
expanding demand for broadband links in oceans and seas. In this paper, a
cellular underwater wireless optical code division multiple-access (UW-OCDMA)
network is proposed to provide broadband links for commercial and military
applications. The optical orthogonal codes (OOC) are employed as signature
codes of underwater mobile users. Fundamental key aspects of the network such
as its backhaul architecture, its potential applications and its design
challenges are presented. In particular, the proposed network is used as
infrastructure of centralized, decentralized and relay-assisted underwater
sensor networks for high-speed real-time monitoring. Furthermore, a promising
underwater localization and positioning scheme based on this cellular network
is presented. Finally, probable design challenges such as cell edge coverage,
blockage avoidance, power control and increasing the network capacity are
addressed.Comment: 11 pages, 10 figure
Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment
In the last decade, integrated logistics has become an important challenge in
the development of wireless communication, identification and sensing
technology, due to the growing complexity of logistics processes and the
increasing demand for adapting systems to new requirements. The advancement of
wireless technology provides a wide range of options for the maritime container
terminals. Electronic devices employed in container terminals reduce the manual
effort, facilitating timely information flow and enhancing control and quality
of service and decision made. In this paper, we examine the technology that can
be used to support integration in harbor's logistics. In the literature, most
systems have been developed to address specific needs of particular harbors,
but a systematic study is missing. The purpose is to provide an overview to the
reader about which technology of integrated logistics can be implemented and
what remains to be addressed in the future
Transmission Delay of Multi-hop Heterogeneous Networks for Medical Applications
Nowadays, with increase in ageing population, Health care market keeps
growing. There is a need for monitoring of Health issues. Body Area Network
consists of wireless sensors attached on or inside human body for monitoring
vital Health related problems e.g, Electro Cardiogram (ECG),
ElectroEncephalogram (EEG), ElectronyStagmography(ENG) etc. Data is recorded by
sensors and is sent towards Health care center. Due to life threatening
situations, timely sending of data is essential. For data to reach Health care
center, there must be a proper way of sending data through reliable connection
and with minimum delay. In this paper transmission delay of different paths,
through which data is sent from sensor to Health care center over heterogeneous
multi-hop wireless channel is analyzed. Data of medical related diseases is
sent through three different paths. In all three paths, data from sensors first
reaches ZigBee, which is the common link in all three paths. After ZigBee there
are three available networks, through which data is sent. Wireless Local Area
Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX),
Universal Mobile Telecommunication System (UMTS) are connected with ZigBee.
Each network (WLAN, WiMAX, UMTS) is setup according to environmental
conditions, suitability of device and availability of structure for that
device. Data from these networks is sent to IP-Cloud, which is further
connected to Health care center. Main aim of this paper is to calculate delay
of each link in each path over multihop wireless channel.Comment: BioSPAN with 7th IEEE International Conference on Broadband and
Wireless Computing, Communication and Applications (BWCCA 2012), Victoria,
Canada, 201
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Performance measurements and analysis of the existing wireless communication technology in Iraq.
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityIraq may be considered as the largest wireless market in the Gulf region. A key driving factor in the market of wireless communication, it has seen enormous growth in the mobile phone market over the last five years leading to almost 24 million subscribers in 2011. Moreover, there are several technologies and services working in Iraq; three GSM Operators, three CDMA national operators and three CDMA provinces operators. The recent growth in the mobile phone market is based on the Global System for Mobile (GSM) communications and Code Division Multiple Access (CDMA) standards creating the next-generation wireless technologies in the Iraqi Wireless Communication market. One of the essential issues of this research is to investigate the performance of the decreased Quality Of Service (QoS) caused by interferences in the services on GSM/CDMA operators in Iraq. Many issues should be studied and taken into consideration, such as; does the Multi-Coalition Forces cause the interferences, jamming, higher rate of calls drop and false ringing; or are they caused by bad design and planning? Do we need to optimise our network due to the large number of users? All these factors are investigated and the measurements of most service providers and government agencies will be gathered. A detailed analysis was included from the providers with measurements of performance and the reasons for the deterioration of wireless services. The novel contributions of this thesis is the extensive radio measurement campaign over the three mobile an CDMA operator networks and the analysis and recommendations that were drawn to suggest the best approach to improve the QoS of Wireless communication technologies. Awareness of actual reasons behind the deterioration of services will be raised to the Iraqi Government, CMC and the wireless service providers
A direct-sequence spread-spectrum communication system for integrated sensor microsystems
Some of the most important challenges in health-care technologies have been identified to be development of noninvasive systems and miniaturization. In developing the core technologies, progress is required in pushing the limits of miniaturization, minimizing the costs and power consumption of microsystems components, developing mobile/wireless communication infrastructures and computing technologies that are reliable. The implementation of such miniaturized systems has become feasible by the advent of system-on-chip technology, which enables us to integrate most of the components of a system on to a single chip. One of the most important tasks in such a system is to convey information reliably on a multiple-access-based environment. When considering the design of telecommunication system for such a network, the receiver is the key performance critical block. The paper describes the application environment, the choice of the communication protocol, the implementation of the transmitter and receiver circuitry, and research work carried out on studying the impact of input data characteristics and internal data path complexity on area and power performance of the receiver. We provide results using a test data recorded from a pH sensor. The results demonstrate satisfying functionality, area, and power constraints even when a degree of programmability is incorporated in the system
Analyzing Delay in Wireless Multi-hop Heterogeneous Body Area Networks
With increase in ageing population, health care market keeps growing. There
is a need for monitoring of health issues. Wireless Body Area Network (WBAN)
consists of wireless sensors attached on or inside human body for monitoring
vital health related problems e.g, Electro Cardiogram (ECG), Electro
Encephalogram (EEG), ElectronyStagmography (ENG) etc. Due to life threatening
situations, timely sending of data is essential. For data to reach health care
center, there must be a proper way of sending data through reliable connection
and with minimum delay. In this paper transmission delay of different paths,
through which data is sent from sensor to health care center over heterogeneous
multi-hop wireless channel is analyzed. Data of medical related diseases is
sent through three different paths. In all three paths, data from sensors first
reaches ZigBee, which is the common link in all three paths. Wireless Local
Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX),
Universal Mobile Telecommunication System (UMTS) are connected with ZigBee.
Each network (WLAN, WiMAX, UMTS) is setup according to environmental
conditions, suitability of device and availability of structure for that
device. Data from these networks is sent to IP-Cloud, which is further
connected to health care center. Delay of data reaching each device is
calculated and represented graphically. Main aim of this paper is to calculate
delay of each link in each path over multi-hop wireless channel.Comment: arXiv admin note: substantial text overlap with arXiv:1208.240
Enhanced Optical Wireless Channel For Indoor And Intravehicle Communications: Power Distribution And Signal To Noise Ratio Analysis
Visible light communicationâ(VLC) provides wide bandwidth and high security
capabilities for free space optical communication. This thesis presents the key concepts,
underlying principles and practical applications of visible light communications. In
particular, this thesis focuses on the received power distribution pattern and signal to noise
ratio for line-of-sight indoor and vehicular applications. Several methods are used to
modify the SNR and power distribution levels. It is shown that in the absence of
obstruction, the optical footprint is nearly circular and offers a platform for large- scale
deployment in commercial environments, which is similar to micro and Pico cells.
By studying various kinds of commonly used VLC channel analysis: diffuse and
line of sight channels, a simple improved indoor and intra-vehicular VLC transmission
model for power distribution and SNR is presented. Employing optical wireless
communications within the vehicle not only enhances user mobility, but also alleviates
radio frequency interference, and lowers system cost through the utilization of license free
spectrum. Moreover, a solution to increase the received power by changing the semi angle
at half power is presented. The simulation results show the improved received power
distribution and SNR. A VLC system, based on color-shift-keying (CSK) modulation and
code-division multiple-access (CDMA) is presented. CSKâCDMA VLC system is used to
enhance the VLC system capacity and mitigate single color light interference, which allows
multiple users to access the network
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