Question

Compare a wireless radio system with a fiber-optic communication system for digital data communications over a distance of 1 km. Assume a desired data rate of 75 Mbps. Give pros and cons, advantages and disadvantages of each. Which one would be better, all factors being considered?

Answer 1

Whenever the word fiber optics comes the very first concept strikes to mind is total internal reflection (TIR) Fiber-optic cable systems convert packets of data into array of light. The light travels through the cable from sender to the receiver, which converts it back into its original form. Wireless communication converts the data it transmits into electromagnetic waves.

In terms of distance wireless signals degrade wIth the distance: The far the user is from the broadcast station, the weaker the signal. Onnthe other hand fiber-optic wires can convey a clear signal much farther: A user at any point gets the same signa as far as if the person is miles away the line.

As far as speed is concerned theoretically a wireless network can transmit data at the same speed as optical fiber. In practice, fiber-optics attains maximum speeds particularly when networks become congested, as all users of wireless networks share the same bandwidth. The more users at one time, the more congested and slower the wireless network becomes cumbersome and slow.

Also as frequency of light is extremely high, it can accommodate very wide bandwidths of information. This results into support for high data rates with excellent reliability.

The optical fiber communication system consist of the following parts-

1.optical fiber transmister 2. Optical fiber cable and 3 Receiver

There are two modes of optical fiber communication system-

1. Multimode fiber. 2. Single mode fiber. These classifications are based on how many times the ray is reflected weyher multiple times or just one time. Let's see the optical fiber communication systems advantages and disadvantages- let's begin with advantages which are as follows

1. Enormous bandwidth

2.Low transmission loss

3.Immunity to cross talk

4.signal security as it won't fail if users increase

5. Flexible and reliable.

5.Ease of installation and

6. Electrical isolation

Besides these advantages fiber optics communication systems has the following disadvantages-

1.cost and expensive

2. Effected by chemicals

3.scattering and absorption

4. Exposed to radiation etc.

Optic fiber communication systems play a major role in aerospace and avionics.

On the other hand wireless communication systems the transmission and all other communication part is done in open space through electromagnetic waves. The information is passed from sender to receiver through a frequency band.called channel. Each channel has its unique frequency. Number of channels can Be used to transmit data in parallel.

It uses different frequency bands based on distance coverage and communication requirements. Various types of modulation methods are used which helps in achieving different bandwidth/data rate.Radio communication is a type of wireless communication which works on the same concept of frequency band called channel concept.The main advantages of radio wireless transmission is-

1. Can be easily generated

2. Omni ddirectional

3.Able to travel long distances

3. Can peneratre through buildings.

The main drawback is its frequency dependence and the relatively lower bandwidth for communication.

Wireless communications relies on the transmission and reception of signals modulated with the information to be carried

Specifications	Optical Communication	Wireless Communication
Mode of data transport	Light using optical transmitter	EM waves are transmitted and received based upon frequency
Data capacity	Unlimited	It has capcity in units of Gbps
Deployment time	Depends on distance to be covered using fiber optic cable	Quick
Deployment in terrain or hilly region	Difficult	Easy as just antennas and equipments are installed to transmit and receive signals
Relocation	Fiber optic cable after deployment can not be reused and difficult to relocate to other places	It is easy to relocate
Effect of Channel (i.e. travel )	No effect as light travels through the fiber optic cable	Yes, as electro-magnetic waves travels in the space from one station to the other

Despite of all these difference communications systems use both fiber optics and wireless transmissions.

Fiber-optic cables are capable of supporting almost unlimited number of bandwidthe due to frequency of light being high.Fixed wireless links since they are sending signals through free space rather than through a medium like ptical fiber or other confined medium, operate within fixed segments of frequency spectrum that must be licensed for different applications to avoid interference from other signals within the same frequency channel in the same location. As a result, the limited bandwidth of wireless system also limit the amount of data to be transferred.