171 research outputs found
Wireless technology: current status and future directions
Wireless Technology is expected to be the dominant
mode of access technology in the future. Besides voice, a
new data range of services such as multimedia and high
speed data are being offered for delivery over wireless
network. Mobility will be seamless, realizing the concept
of persons' being in contact anywhere, at any time.
Throughout this paper, we review the long, interesting
development of wireless communication in the past,
examine the current progress in standards and
technologies, and finally discuss possible trends for
wireless communication solutions
Efficient Handoff for QoS Enhancement in Heterogeneous Wireless Networks (UMTS/WLAN Interworking)
Today’s Wireless Communications technologies prove us that wireless communications will in the long run be composed of different communication networks as a way to benefit from each other. This can however be achieved from cellular networks and wireless local area networks that show some compatible characteristics that enable them be integrated. Scenarios typically behind these integrations is the UMTS and WLAN interworking where UMTS network is known for its wide area of coverage and nearly roaming however, known for lack of enough data rate. This is contrary with WLAN which is known for high data rate and cheaper compared to UMTS. WLAN however has a small area of coverage and lacks roaming. This in regard brings the idea that the two different networks being integrated could provide the means for mobile users to be gratified with a supported coverage and quality at anywhere and anytime with seamless access to internet
Realizing mobile multimedia systems over emerging fourth-generation wireless technologies
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (p. [161]-167) and index.by Pei-Jeng Kuo.M.Eng
A study on stryi-icnos potatorum and pisum sativum as natural coagulants for meat food processing wastewater
Slow maintained load test is widely used by contractors in Malaysia to ensure the driven pile could accommodate the design load of the structure. Slow maintained load test is a test to determine load-settlement curve and pile capacity for a period of time using conventional load test. Conventional static pile load test equipment is large in size thus making it heavier and takes a long time to install. In addition, it consumes a lot of space which causes congestion at construction sites. Therefore, the objective of this thesis is to conduct a conventional load test by replacing the pile kentledge load with anchorage and reaction pile. Preparations of ten designs comprising six commercial designs were reviewed. In addition, four proposed designs were suggested for the setup. Final design was produced based on its safety factors and criteria referred via literature review. The test frame consists of reaction frame with four reaction helical pile with two helixes per reaction pile. The deformation shapes, safety factor, stress, and strain of the design and finite element of the model has been analysed with the use of SolidWorks and Pia.xis 30 software. SolidWorks software emphasizes on the model load-deflection relationship while Plaxis 30 ensures a correlation of reaction between pile uplift force and soil. Then, the model was tested on site to determine the relationship between physical loaddeflection and pile-soil uplift force. The results of uplift force and displacement for numerical and physical test were nearly identical which increment of loaddisplacement graph pattern. The higher the uplift force, the higher the displacement obtained. In conclusion, the result obtained and the design may be considered as a guideline for future application of sustainable slow maintained pile load test
Technology Directions for the 21st Century
New technologies will unleash the huge capacity of fiber-optic cable to meet growing demands for bandwidth. Companies will continue to replace private networks with public network bandwidth-on-demand. Although asynchronous transfer mode (ATM) is the transmission technology favored by many, its penetration will be slower than anticipated. Hybrid networks - e.g., a mix of ATM, frame relay, and fast Ethernet - may predominate, both as interim and long-term solutions, based on factors such as availability, interoperability, and cost. Telecommunications equipment and services prices will decrease further due to increased supply and more competition. Explosive Internet growth will continue, requiring additional backbone transmission capacity and enhanced protocols, but it is not clear who will fund the upgrade. Within ten years, space-based constellations of satellites in Low Earth orbit (LEO) will serve mobile users employing small, low-power terminals. 'Little LEO's' will provide packet transmission services and geo-position determination. 'Big LEO's' will function as global cellular telephone networks, with some planning to offer video and interactive multimedia services. Geosynchronous satellites also are proposed for mobile voice grade links and high-bandwidth services. NASA may benefit from resulting cost reductions in components, space hardware, launch services, and telecommunications services
InfoTech Update, Volume 13, Number 1, January/February 2004
https://egrove.olemiss.edu/aicpa_news/5002/thumbnail.jp
Design And Analysis Of a Multi-channel Optical Fibre Lan Based On Modified Csma/cd Protocol
Nowadays, optical communication is widely employed by telecommunication
providers in the whole world due to its ability to support high bit rate applications. The
urge to provide end-to-end fibre connectivity arises to overcome the bottleneck problem
that occurs when packets are transmitted on the slower speed medium such as copper. In
optical transmission, bandwidth utilisation can be improved further by using multiple
wavelengths or channels in a single fibre.
This thesis discusses the implementation of multiple wavelengths technique for
Local Area Network (LAN) environment. It proposes a new Ethernet-based protocol that
uses multiple wavelengths for transmission, which runs on a single fibre. Ethernet/IEEE
802.3 is chosen because of its widespread employment in today's network and the
ability of extending the transmission rate up to gigabit transmission. Even though light
does not collide with each other, receiver contention might occur if more than one signal
arrives at the receiver at the same time. Therefore, some arbitration mechanism is
needed to synchronise the transmission and the tuning time of the respective transmitter and receiver. The proposed design is based on the physical bus topology with n number
of connected nodes and m number of operating wavelengths. All nodes are able to listen
to all wavelengths. A fast control unit is used, which is responsible for packet
scheduling.
The packets are scheduled based on a pre-computed time. Both transmitter and
receiver will be asked to tune to the· allocated wavelength. The transmitter can start
transmitting and the receiver will start tuning at a specified time. Control packets are
used for handshaking purposes. The main operation is placed at the control unit so that
no added complexity is experienced by the receiver. Thus, this technique further reduces
the cost. A suitable range of channels is obtained from the result. The network
performance is evaluated against several design parameters by comparing the
performance of each channel. The result shows a significant improvement whereby the
throughput and efficiency are increased and average delay is minimised compared to the
conventional system
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