RFOptical vs. Wireless Communication: A Detailed Comparison
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This article explores the differences between optical communication and wireless communication, outlining the pros and cons of each technology.
Optical Communication
Optical communication leverages light as the medium for data transmission. Like radio waves, light is an electromagnetic signal. By modulating light, we can transmit information across fiber optic cables. Due to the extremely high frequency of light, optical communication supports very wide bandwidths, resulting in high data rates and excellent reliability.
Figure 1 illustrates a typical fiber optic communication system. Here’s a breakdown of how data flows through the system:
- Step 1: The information (voice, video, data) is converted into a format compatible with the medium. This often involves a coder or converter, such as an Analog-to-Digital (A/D) converter, to transform analog signals into digital pulses. Computer data, already in digital form, bypasses this step.
- Step 2: An optical transmitter device, such as an LED (Light Emitting Diode), flashes a light source ON and OFF based on digital pulses. Infrared beams can also be used. Another common optical transmitter is a solid-state laser.
- Step 3: The light beams are carefully fed into a fiber optic cable for long-distance transmission.
- Step 4: At the receiving end, optical receiver devices like photocells or light detectors detect the light pulses. These devices convert the light pulses into electrical signals. An amplifier is used to amplify and reshape the signal back into digital form.
- Step 5: The digital pulses are then fed to a decoder, which converts them back into the original voice/video format. This often involves a Digital-to-Analog (D/A) converter.
For longer distances, optical repeaters are strategically placed along the fiber optic cable to boost the signal.
Refer to the advantages and disadvantages of fiber optic systems for more details.
Wireless Communication
Wireless communication, on the other hand, uses electromagnetic waves as the medium for transmitting information. Different frequency bands are used, depending on the desired distance coverage and terrain requirements. Various modulation schemes are employed to achieve different bandwidths and data rates.
There are many types of wireless communication, including:
- Satellite communication
- Microwave line of sight communication
- Cellular communication (GSM, CDMA, LTE, etc.)
- Short-range wireless communication (WLAN, Bluetooth, Zigbee, Zwave, LoRaWAN, etc.)
Refer to the advantages and disadvantages of wireless communication, what is Wireless, wireless system basics and wireless propagation modes for more information.
Optical vs. Wireless: A Comparative Table
The following table summarizes the key differences between optical and wireless communication:
| Specifications | Optical Communication | Wireless Communication |
|---|---|---|
| Mode of data transport and devices used for it | Light using optical transmitter (LED, Laser diode) and receiver (photo diode) | EM waves using antennas at both transmit and receive end |
| Data capacity | Unlimited | It has become to have capcity in units of Gbps due to advent of wireless technologies such as LTE, LTE-Advanced, WLAN (11ac/11ad) etc. |
| 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 required to be installed | |
| Relocation | Fiber optic cable after deployment can not be reused and difficult to relocate to other places | It is easy to dismantle and install the equipments at other places |
| Effect of Channel (i.e. travel during environment) | No, as light travels within the fiber optic cable | Yes, as electro-magnetic waves travels in the open air from one station to the other |
Emerging Technologies: Optical Wireless Communication
There is a technology emerging which utilizes benefits of both optical and wireless communications and known as Optical Wireless Communication.
