Radio types microwave wifi cellular satellite

In addition, businesses use wireless transmission media in locations where it is impossible to install cables. Types of wireless transmission media used in communications include infrared, broadcast radio, cellular radio, microwaves, and communications satellites.

As discussed earlier in the chapter, infrared IR is a wireless transmission medium that sends signals using infrared light waves. Mobile computers and devices, such as a mouse, printer, and smart phone, often have an IrDA port that enables the transfer of data from one device to another using infrared light waves. Broadcast Radio.

Broadcast radio is a wireless transmission medium that distributes radio signals through the air over long distances such as between cities, regions, and countries and short distances such as within an office or home. Cellular Radio. Cellular radio is a form of broadcast radio that is used widely for mobile communications, specifically wireless modems and cell phones.

A cell phone is a telephone device that uses high-frequency radio waves to transmit voice and digital data messages. Some mobile users connect their notebook computer or other mobile computer to a cell phone to access the Web, send and receive e-mail, enter a chat room, or connect to an office or school network while away from a standard telephone line.

Read Looking Ahead for a look at the next generation of cellular communications. Microwaves are radio waves that provide a high-speed signal transmission. Microwave transmission, often called fixed wireless, involves sending signals from one microwave station to another shown in Figure on page Microwaves can transmit data at rates up to 4, times faster than a dial-up modem.

MIMO antennas are applied in radio. They are used at the receiving and transmitting points to enhance the process of communication. MIMO antenna is among the best technologies in smart antenna. There are two ways of exploiting multiple antennas in MIMO.

One, they are used in creating highly effective antenna directivity. They are also used in the transmission of parallel data streams. These antennas receive and radiate energy in all horizontal directions equally. Omnidirectional antennas offer a perfect solution for applications that need good all-around coverage.

In special applications, the antennas can be used to accommodate a specific down tilt to achieve a near field coverage. These designs are made specifically to stabilize and align the antenna automatically. At the same time, they maintain the point to point path in the movement of a platform in unstable surroundings. Tracking antenna is routinely used in aviation, offshore drilling, marine, and mobile platforms. Here, the operators depend on Line-of-Sight LoS communications. This is a versatile antenna that utilizes a driven element.

Behind the driven element is a reflector while in front of it is a director or several directors. The design of the yagi antenna is significant as it is easy to optimize for features such as bandwidth, front-to-back ratio, and gain using the available modern antenna design software. Some of the antenna designs use a corner reflector at the back of the driven element to enhance performance. Yagi antennas are easy to construct.

This is only when there is available material. These antennas are used in various airborne platforms as radio navigation and communication systems. In order to increase the communication distance of the system repeaters are used. It may or may not does frequency conversion before retransmission depending upon applications of use. Following are the two main repeater types based on data type it can handle.

Analog Repeater : It can amplify the analog signal in order to boost its amplitude. Usually trunking system employs FDM type of multiplexer which uses multiple analog signals in the form of current or voltage whose amplitude gets attenuated over transmission medium. The analog repeater is used here. It cosists of linear amplifier and filters. Digital Repeater or Digipeater : It can amplify the digital signal to compensate for losses over medium.

It is also known by name "Digipeater". This digipeater helps in pulse re-shaping, demodulation, decoding and re-synchronization at the receiver end. Let us understand repeater types based on technologies it can serve viz. In microwave link, repeater is employed between transmitting station and receiving station. Depending upon distance between them, there may be one or multiple repeater stations in between.

This type of repeaters use sensitive receivers, high power transmitters and high mounted antennas. They are very effective to increase the communication range of microwave link. In microwave relay stations, one repeater pickes the signal at one frequency, amplifies it and retransmits it on another frequency to the next repeater in the chain.

The next repeater does the same task.