HIMCOM-Heritage Institute of Management & Communication

                                                                          Remote control Radio remote control is the use of electronic control signals sent by radio waves from a transmitter to control the actions of a device at a remote location. Remote control systems may also include telemetry channels in the other direction, used to transmit real-time information of the state of the device back to the control station. Unmanned spacecraft are an example of remote controlled machines, controlled by commands transmitted by satellite ground stations. Most handheld remote controls used to control consumer electronics products like televisions or DVD players actually operate by infrared light rather than radio waves, so are not examples of radio remote control. A security concern with remote control systems is spoofing , in which an unauthorized person transmits an imitation of the control signal to take control of the device. Examples of radio remote control: ·          Unaman

                                    Radio location Radio locating  is the process of finding the location of something through the use of radio waves. It generally refers to passive uses, particularly radar—as well as detecting buried cables, water mains and other public utilities. It is similar to radio navigation, but radiolocation usually refers to passively finding a distant object rather than actively one's own position. Both are types of radio determination. Radiolocation is also used in real-time locating system (RTLS) for tracking valuable assets. Basic Principal An object can be located by measuring the characteristics of received radio waves. The radio waves may be transmitted by the object to be located, or they may be  backs cattered waves (as in radar or passive RFID). A stud finder uses radiolocation when it uses radio waves rather than ultrasound. One technique measures a distance by using the difference in the power of the received signal strength

                                                                                                             Radar Radar is a  radio location method used to locate and track aircraft, spacecraft, missiles, ships, vehicles, and also to map weather patterns and terrain. A radar set consists of a transmitter and receiver. The transmitter emits a narrow beam of radio waves which is swept around the surrounding space. When the beam strikes a target object, radio waves are reflected back to the receiver. The direction of the beam reveals the object's location. Since radio waves travel at a constant speed close to the speed of light, by measuring the brief time delay between the outgoing pulse and the received "echo", the range to the target can be calculated. The targets are often displayed graphically on a map display called a  radar screen .  Doppler radar can measure a moving object's velocity, by measuring the change in frequency of the return radio waves due

                                                                              Space communication This is radio communication between a spacecraft and an Earth-based ground station, or another spacecraft. Communication with spacecraft involves the longest transmission distances of any radio links, up to billions of kilometers for interplanetary spacecraft. In order to receive the weak signals from distant spacecraft, satellite ground station s use large parabolic “ dish antennas  up to 25 metres (82 ft) in diameter and extremely sensitive receivers. High frequencies in the microwav band are used, since microwaves pass through the ionosphere without refraction, and at microwave frequencies the high gain antennas needed to focus the radio energy into a narrow beam pointed at the receiver are small and take up a minimum of space in a satellite. Portions of the UHF, L,C, S, K, and k band are allocated for space communication. A radio link which transmits data from the Earth's

                                                                                 Data communications Wireless Networking:   Automated radio links which transmit digital data between computer and other wireless devices using radio waves, linking the devices together transparently in a computer network. Computer networks can transmit any form of data: in addition to email and web pages, they also carry phone call audio, and video content Security is more of an issue for wireless networks than for wired networks since anyone nearby with a wireless modem can access the signal and attempt to log in. The radio signals of wireless networks are encrypted using WPA. Wireless LAN: b ased on the IEEE802.11   standards, these are the most widely used computer networks, used to implement local area network   without cables, linking computers, laptops, cell phones, video game consoles , smart TV  and printers  in a home or office together, and to a wireless router  connecti

                                             One way voice communication One way, unidirectional radio transmission is called simplex Baby Monitor: this is a crib side appliance for mothers of infants that transmits the baby's sounds to a receiver carried by the mother, so she can monitor the baby while she is in other parts of the house. These transmit in FM on 49.300, 49.830, 49.845, 49.860, or 49.875 MHz with low power. Many baby monitors have duplex channels so the mother can talk to the baby, and video cameras to show a picture of the baby, this is called a  baby cam . Wireless Microphone: a battery powered microphone with a short range with a short-range transmitter which is handheld or worn on a person's body which transmits its sound by radio to a nearby receiver unit connected to a sound system. Wireless microphones are used by public speakers, performers, and television personalities so they can move freely without trailing a microphone cord. Analo

                                                               Two way voice communication A  two-way radio  is an  audio   transceiver , a  receiver  and  transmitter  in the same device, used for bidirectional person-to-person voice communication. An older term for this mode of communication is  radio telephony . The radio link may be  half-duplex , as in a  walkie-talkie , using a single radio channel in which only one radio can transmit at a time, so different users take turns talking, pressing a " push to talk " button on their radio which switches off the receiver and switches on the transmitter. Or the radio link may be  full duplex , a bidirectional link using two radio channels so both people can talk at the same time, as in a cell phone. ·          Cell phone  – a portable wireless  telephone  that is connected to the  telephone network  by radio signals exchanged with a local antenna at a  cellular base station  ( cell tower ).   The service area covered b

                                                  Bandwidth A modulated radio wave, carrying an information signal, occupies a range of  frequencies . See diagram. The information ( modulation ) in a radio signal is usually concentrated in narrow frequency bands called  sidebands  ( SB ) just above and below the  carrier  frequency. The width in  hertz  of the frequency range that the radio signal occupies, the highest frequency minus the lowest frequency, is called its  bandwidth  ( BW ). A given amount of bandwidth can carry the same amount of information ( data rate  in  bits  per second) regardless of where in the radio frequency spectrum it is located, so bandwidth is a measure of  information-carrying capacity . The bandwidth required by a radio transmission depends on the data rate of the information (modulation signal) being sent, and the  spectral efficiency  of the  modulation  method used; how much data it can transmit in each kilohertz of bandwidth. Different type

                                                                                Radio communication In radio communication systems, information is carried across space using radio waves. At the sending end, the information to be sent is converted by some type of  transducer  to a time-varying  electrical signal  called the modulation signal. The modulation signal may be an  audio signal  representing sound from a  microphone , a  video signal  representing moving images from a  video camera , or a  digital signal  consisting of a sequence of  bits  representing binary data from a computer. The modulation signal is applied to a  radio transmitter . In the transmitter, an  electronic oscillator  generates an  alternating current oscillating at a  radio frequency , called the  carrier wave  because it serves to "carry" the information through the air. The information signal is used to  modulate  the carrier, varying some aspect of the carrier wave, impressing the informa