Communication system transmit information from one place to another place by means of electric energy. This paper describes the analysis and design of electronic circuits used in radio frequency communication systems covering the frequency range up through several hundred megahertz the actual frequency lit depends upon whether the circuit is realized with decree components or as an integrated circuit.
The electromagnetic waves that leave transmitting antenna arrive at the receiving antenna in one of the many waves. These include ground waves, sky waves, space waves, and via satellites. Ground waves travel along the ground and follow the terrain. Radio wave propagation is concerned with how radio signal generated by a transmitter moves to receiver located some distance away. As the portion of electromagnetic frequency spectrum that is used for broadband wireless communication extends from 300 MHz to 300 GHz. The frequency range covers over wavelength from 1m to 1mm. In these frequencies bands, radio waves are transmitted as space waves. That is, neither ground nor sky waves are used at these frequencies.
The simplest radio –propagation environmental is free space with no atmosphere and no solid object along the path between the transmitter and receiver. Such an environmental permits radio signals to travel in a line-of-sight manner and be received as direct waves. Unfortunately, this model is oversimplification of practical propagation environments where the radiated wave comes in contact with solid objects that produce changes in its amplitude, phase, and direction of propagation. Even in the absence of solid objects, the radio signals strength decreases as the probation distance increases. The medium over which the radio wave tra...
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...ts. This means that the network management system must be such that will periodically monitor the RSSI for each mote. When the RSSI is below a predefined threshold, it should be possible to remotely reconfigure the affected mote so that it can access the network via the second access point that it can see.
The task of managing the network is complicated by many factors, which include the different networking technologies, heterogeneous systems from a myriad of vendors; and a number of distributed applications, some of which have vendor specific requirements. Added to this is the fact that many new network applications are imposing great QoS and security demands on the network. The task of configuring the network to meet the end-to-end QoS and security requirement of each application is a tedious one that cannot be handled by traditional network management systems.
through space. This theory came to life when Heinrich Hertz created those waves and seven
Electromagnetic waves are waves that can propagate even though there is no medium. A magnetic field that changes with time can generate an electric field that also changes with time, and an electric field that changes with time can also produce a magnetic field. If the process is continuous it will produce a magnetic field and electric field continuously. If these magnetic fields and electric fields simultaneously propagate (spread) in space in all directions then this is a symptom of the wave. Such a wave is called an electromagnetic wave because it consists of an electric field and a magnetic field that travels in space.
Waves are all around us and come in various forms. Sound waves can travel through air because air is made of molecules, which carry the sound. Another type of wave is electromagnetic waves, which are different than sound waves because they don’t need molecules to travel. This means that electromagnetic waves can travel through air and solid materials as well as empty space (Groleau 2011). The electromagnetic spectrum consists of all waves of energy found in our universe. Radio waves, microwaves, infrared light, visible light, UV light, X-rays, and gamma rays, are the are the most common wavelengths on the spectrum. Wavelength is the distance between one wave crest (peak) to the next. Waves in the electromagnetic spectrum vary in size-- from very long radio waves the size of buildings, to very short gamma rays smaller than the size of the nucleus of an atom. But you may ask, are all of these waves that different from one another? The answer in fact, is no! What differentiates these types of waves is the amount of energy they carry. Photons, the smallest massless unit of energy, bundle up and travel in waves. The amount of photons that travel are measured and classified by the energy they posses. As the wavelength of the waves decrease, the amount of energy of the photons increases (Bitesize 2011).
Nature of wave: It is an electromagnetic wave as it does not necessarily require a medium for p...
By 1920, radio circled the globe and the first radio transmitter was developed and broadcasted programs for the public. Later, the idea of the radio was adopted by television, radar and communication systems, due to the advancement in electronics equipment and enabled radio waves to be sent over greater
During the year of 1895 an Italian man by the name of Guglielmo Marconi invented radio signals. I also believe that this invention will be a great use in the nearest 20th century. This invention will allow people to communicate through radio waves even if the person is far away. As well as that the world might even begin to use this invention to spread the news and music to people all over the world. Marconi’s invention will revolutionize the people connect with each other by allowing communication over hundreds of miles and more.
Around 1886, Heinrich Hertz demonstrated experimentally the existence of radio waves. It is said that Hertz only smiled incredulously when anyone predicted that his waves would one day be sent round the earth. Hertz died in 18...
Radar: detects the presence, distance and speed of passing objects by sending out radio waves;
The waves are large enough to interact with clouds and other atmospheric objects. The waves strike the atmospheric objects and bounce back toward the receiver at the station.
Frink, S. (2012, August). Space Communications Forge Ahead, Military & Aerospace Electronics, 23 (8), p1, 12
The two main parts of a radio telescope are the antenna system and the radio receiver. The antenna system is used to detect radio-frequency radiation that comes from extraterrestrial sources. The radio receiver, also known as a radiometer, is extremely sensitive and takes the radio waves that are received by the antenna and converts them into electrical signals. Radio receivers must be kept a freezing temperatures or below in order to reduce
Network management planning and security planning involves identifying the best and most appropriate systems and hardware that the firm can use to better manage network and plan security systems. Therefore, the management required me to examine the best software and hardware systems in the market place that the company can adopt to enable it to manage the network and security. The management required me to advice on the implementation procedure of various plans that are going to be adopted. My responsibility also involved finding out or predicting the impact of the plan on the future operations. They required me to evaluate the challenges the company might face while adopting the changes in the network management plan and security plans.
Analog communication employs continuous transmission of an electromagnetic wave form that varies in frequency and amplitude.
Networks in organisation are dynamic and complex entities which can be quite challenging to configure and manage. (Kim & Feamster 2013). These corporate networks consist of multiple routers, switches, firewalls, middleboxes and a particular advantage of network management is the ability to monitor the entire business network. As all the devices are interconnected with many event occurring simultaneously, problems with once device can eventually lead and spread throughout...
Radar can be traced back as far as 1832 when British physicist Michael Faraday suggested the existence of an electromagnetic field between certain objects from his scientific observations. Working from these ideas, British physicist James Clerk Maxwell predicted mathematically the existence and behavior of radio waves in 1873. In 1886, physicist Heinrich Hertz from Germany and Elihu Thomson from America confirmed the existence of radio waves with demonstrations showing examples of reflection, refraction, and direction finding of radio waves. By 1904, Christian Hulsmeyer, a German inventor, applied for a patent for a device that used radio waves in a collision-avoidance device for ships.