CH-4 Communication Devices Marks: 06(09)
Introduction:
In the present days, wireless communication system has become an essential part.
Various types of wireless communication devices that permits user to communicate even from remote operated areas.
There are many devices used for wireless communication like mobiles, Cordless telephones, GPS, Wi-Fi, satellite television, broadcast radio, Microwave radio, and Bluetooth and wireless computer parts.
Current wireless phones include 3G and 4G networks, Bluetooth and Wi-Fi technologies.
Wi-Fi:
Wi-Fi is Wireless Local Area Networking. It is a low power wireless communication, that is used by various electronic devices like smart phones, laptops etc.
In this setup, a router works as a communication hub wirelessly.
These networks allow users to connect only within close proximity to a router.
Wi-Fi is very common in networking applications which affords portability wirelessly.
These networks need to be protected with passwords for the purpose of security, otherwise it will access by others.
Routers:
Routers are internetwork connectivity devices. A router is a networking device that forwards data packets between computer networks.
The most familiar type of routers are home and small office routers that simply pass IP packets between the home computers and the Internet.
Broadcast routers can be used to connect two different computers or to connect two computers to the Internet.
Wireless routers connect to your modem and create a wireless signal in your home or office. So, any computer within range can connect to your wireless router and use your broadband Internet for free. The only way to keep anyone from connecting to your system is to secure your router.
Routers can also be used to divide large, busy LANs into smaller segments.
Routers are also employed to connect LAN to wide area network (WAN).
Routers are of two types – 1. Static routers 2. Dynamic routers
Bluetooth Technology:
It is Wireless Personal Area Networking. The main function of the Bluetooth technology is to connect a various electronic devices wirelessly to a system for the transferring of data.
Cell phones are connected to hands free earphones, mouse, and wireless keyboard.
By using Bluetooth device the information from one device to another device.
This technology has various functions and it is used commonly in the wireless communication market.
It uses short wavelength radio waves in UHF band from 2402MHz to 2480MHz or 2400 to 2583.5MHz. Maximum speed is 25Mbits/s and maximum range 10 meters.
Applications of Bluetooth:
Wireless control of communication between a mobile phone and hands free headset.
Wireless control of communication between a mobile phone and Bluetooth compatible car stereo system.
Wireless Bluetooth headset and intercom.
Wireless networking between PCs where little bandwidth is required.
Wireless communication with PC input and output devices.
Global Positioning System (GPS):
GPS is space based radio navigational system owned by United States Government. Its primary function is navigation.
This system is basically a network of 24 low earth satellites spaced equally around the world in overlapping patterns.
Each satellite transmits a unique signal back to earth on microwave frequencies such as 1575.42MHz and 1227.6MHz.
Receivers on earth pick up transmissions from four satellites simultaneously. The receiver uses the signals in microprocessors to compute exact position of receiver on earth.
The receiver output is display giving the latitude, longitude and latitude of the receiver.
GPS can be used by military, individuals and industries foe general navigation purposes.
The accuracy is less than 100m from the actual from the actual location for civilian.
The military system error is less than 40m.
Therefore you can know your position on earth at any time using low cost hand held microwave GPS receiver.
Applications of GPS:
Civilian Applications
Navigation – Used by navigators for orientation and precise velocity measurements.
Surveying – Surveyors create maps and verify the boundaries of the property.
Map-making – Used by civilians and military cartographers.
In agriculture
In astronomy
In automated vehicles for applying location and routes for cars and trucks to function without a hums driver.
In cell phones
In disaster relief services
Military Applications
Navigation – Soldiers can find objectives in the dark and unknown regions with the help of GPS.
Search and Rescue
Target tracking – Military weapon systems use GPS to track air.
Nuclear detonation detectors
Missile and projectile guidance
Advantages of Wireless Communication:
Any data or information can be transmitted faster and with a high speed
Maintenance and installation is less cost for these networks.
The internet can be accessed from anywhere wirelessly
It is very helpful for workers, doctors working in remote areas as they can be in touch with medical centers.
Disadvantages of Wireless Communication:
An unauthorized person can easily capture the wireless signals which spread through the air.
It is very important to secure the wireless network so that the information cannot be misused by unauthorized users
Questions
Marks wise Questions: 1M(3), 3M(2)
1. Fill in the blanks-
-------- is used for looking your destination through satellite on your phone.
(i) Bluetooth (ii) GPS (iii) Wi-Fi
In GPS for knowing location on earth signals from minimum ------------ satellites are necessary.
(i) One (ii) Two (iii) Four
------- is used for two way voice communication.
(i)Radio (ii) Bluetooth (iii) Mobile
----------- technology is used for exchanging data over short distance.
(i) Satellite (ii) Bluetooth (iii) GPS
2. Match the following.
A B
(a) Bluetooth (i) Navigation
(b) Wi-Fi (ii) Wireless Personal Area networking
(c) GPS (iii) Wireless Local Area Networking
3. Answer the following
Write a note on Wi-Fi
Explain Bluetooth technology. Write its applications.
Explain Global Positioning System.
Write difference between Wi-Fi and Bluetooth.
State applications of GPS for civilians and military.
State advantages and disadvantages of wireless communication system.
