The unguided media is also known as the wireless media and uses electromagnetic and light signals to transmit the information. There are various advantages of using unguided media such as the information can be transmitted over a long distance with the help of the electromagnetic rays with the speed of light, there are fewer requirements of the physical equipment as compared to the guided or wired media which requires ethernet cables, repeaters, routers and switches to work. The wireless media consists of various transmission methods they are
Radio Waves transmission
Infrared waves transmission
Microwaves (Terrestrial microwaves)
The microwaves are used to transmit the data or information without the use of cables or wire from one place to another. For the transmission of the microwaves, the antennas are mounted over the tall buildings or towers, these are parabolic antennas and are used to transmit the data beams from one antenna to another that may be kilometers away.
Let’s see what are some important characteristics of microwave transmission. In microwave transmission, the higher the height of the tower the more is the range for the distance of the beam transmitted from the antennas. These antennas also work in the line of sight only. Microwave transmission is relatively inexpensive for the transmission of information for smaller distances but as the distance increases the costlier the transmission becomes as more cost is required in the construction of the tower of greater heights. The loss of signals or attenuation can occur by the atmospheric conditions and instructions such as buildings, the attenuation is heavily affected by the environment conditions, signal strength, and the size of the antenna.
Radio waves transmission
The radio wave transmission uses 10KHz to 1 GHz of the frequency for the transmission of the information. The wave form of the radio waves transmission occurs are the continuous sine waves. There are three types of radio waves that occur in the transmission these are short radio waves, VHF ( Very High Frequency) Radio waves, and the UHF (Ultra High Frequency) Radio waves are all different types of radio waves. The short radio waves are also used in AM (Amplitude Modulation) radio which is used for transmission of signals for a long distance. The VHF radio waves are used in FM ( Frequency Modulation ) and also they are used in TV broadcasting. The UHF radio transmissions are used in the TV remote.
There are two most important components in radio wave transmission these are the transmitter and the receiver. The transmitter is the component that converts the electronic signal to electromagnetic waves and after encoding the signals it sends it to the destination. The other component of the radio waves is the receiver which converts the received encoded electromagnetic signals and decodes them into the electronic signals to be processed by the devices.
The advantages and disadvantages of radio wave transmission are the same as the microwave. The radio waves can travel a long-distance without being affected by the problem of land acquisition. The radio waves are able to offer mobility to its users and the communication can easily be established in the mountains and high altitude terrains where the wired medium is absolutely difficult to transmit the information.
There are also some disadvantages of the radio waves such as that they are susceptible to weather conditions and can be obstructed by bad weather conditions. The communication of the radio waves can be susceptible to eavesdropping which makes it less secure.