|
Abstract of Cellular Radio
Cellular mobile
radio systems aim to provide high-mobility, wide-ranging, two-way wireless voice
communications. These systems accomplish their task by integrating wireless access
with large-scale networks, capable of managing mobile users. Cellular radio technology
generally uses transmitter power at a level around 100 times that used by a cordless
telephone (approximately 2 W for cellular). Standards
Cellular
radio has evolved into digital radio technologies, using the systems standards
of GSM (at 900 and 1800 MHz) in Europe, PDC in Japan, and IS-136A and IS-95A in
the United States. Third-generation systems, such as wideband code division multiple
access (WCDMA) and cdma2000, are currently under development. Design
Considerations
One of the most significant consideration in designing digital
systems is the high cost of cell sites. This has motivated system designers to
try to maximize the number of users per megahertz, and users per cell site.
Another
important consideration is maintaining adequate coverage in areas of varying terrain
and population density. For example, in order to cover sparsely populated regions,
system designers have retained the high-power transmission requirement to provide
maximum range from antenna locations.
Communications engineers have also been
developing very small coverage areas, or microcells. Microcells provide increased
capacity in areas of high user density, as well as improved coverage of shadowed
areas. Some microcell base stations are installed in places of high user concentrations,
The mobile radio is a two-way communication gadget that operates through radio frequencies. As such, the channel of information and messages in a mobile radio is variable. Used to be known as radiophone, the earlier versions of the mobile radio, were one-way communication systems used for broadcast.
Contemporary mobile radio systems can have as much as a hundred channels and may be controlled by microprocessors. These types require the use of software to encode channels and operate their integrated functions. The mobile radio, also known as a two-way radio system, allows the exchange of messages only with other mobile radios through push-to-talk (PTT) functions. A mobile radio also features wireless transceivers, making mobile radios portable. Mobile radio systems may be used for communications in aircraft, ships, automobiles, and other vehicles. The power supply on which mobile radios run depend on the type of vehicle these are mounted on.
A mobile radio system is composed of a transceiver and microphone with a push-to-talk key. It has an antenna that links to the transceiver. Since most types of mobile radio are used in moving vehicles, where the surrounding noise can be loud, some mobile radio types come with an external speaker. Other models have headsets and microphones with noise-reduction capabilities.
How does a mobile radio work?
Most mobile radios operate on a single band of frequency. The radio transceiver contains transmit and receive frequencies. Very high frequency (VHF) and ultra high frequency (UHF) allow a mobile radio to operate on maximum coverage. This means that its average operating range is from 150 to 470 MHz.
To transmit a message, the PTT key must be pressed during talk-time to allow the voice message to be dispatched by the sending party. During this period, the sending party cannot hear or receive any incoming messages from the mobile radio. Once the PTT button is released, the sender may hear the response of the receiving party.
Why do we need a mobile radio
The use of mobile radio in transportation, security, and general operations makes communication fast, efficient and safe. It allows control centers to monitor location of vehicles and dispatch announcements to several receivers simultaneously.
Additionally, the range of its area coverage is very high and is not dependent on a cellular network, which may fluctuate during emergency situations. Different types of mobile radio are portable and capable of withstanding shock and severe weather conditions. Most countries impose certain requirements on the manufacture, sale and use of two-radio systems. This helps ensure that the communication gadget functions according to standards and that its use does not interfere with other communication systems.
You may also like this : Bio Battery, Paper Battery , Smart Antenna, Mobile Train Radio Communication, Hydrogen Super Highway , Humanoids Robotics, Optical Ethernet , Transparent Electronics , Thermography , Surface Plasmon Resonance , Microwave Superconductivity , Memristor , Earthing transformers For Power systems, Direct Current Machines , DD Using Bio-robotics , Wireless LAN Security , Smart Note Taker , Clos Architecture in OPS, 4G Wireless Systems , Wearable Bio-Sensors , Poly Fuse , Non Visible Imaging , Nuclear Batteries-Daintiest Dynamos , MILSTD 1553B , Micro Electronic Pill , MOBILE IPv6 , Chip Morphing , Challenges in the Migration to 4G, CAN , BIT for Intelligent system design, A 64 Point Fourier Transform Chip , Anthropomorphic Robot hand: Gifu Hand II , ANN for misuse detection, Adaptive Optics in Ground Based Telescopes , Aluminum Electrolytic Capacitors , IBOC Technology , Honeypots , Immersion Lithography , Grating Light Valve Display Technology , Fractal Antennas , HART Communication ,E-Textiles, Electro Dynamic Tether , FPGA in Space , DV Libraries and the Internet , Co-operative cache based data access in ad hoc networks , Mesh Topology , Mesh Radio, Metamorphic Robots, Low Energy Efficient Wireless Communication Network Design,Electronics Seminar Reports, PPT and PDF.
|
Labels : Advanced Technical Seminar Topics for ECE, IEEE Seminar Topics for ECE 2012|2011|2009, Electronics Seminar Topics for Diploma Students, Seminar PPT Electronics Communication, Electronics Seminar PPT Abstract, Electronics Seminar Topic Full Paper Download, Latest PPT for Electronics, Latest Electronics Seminars PPT, Electronics Seminars for You, Electronics Seminars Topics Latest, Electronics Seminars PPT,Electronics Seminars 2012|2011|2010
<<back |
