Collection and use of information is an essential process in human civilisation.
Now a days the the knowledge economy makes up a large share of all economic activity in many economies.
Even though the technological developments started in 1800s, the recent information revolution is result of the development of technologies (such as computers, digital communication, microchips) in the second half of the 20th century.
Communication is the transmission of information. It can be achieved through various methods, mediums and technologies.
A medium is a channel or system of communication. It can be broadly classified as
|Personal||Only the message senders and the message receivers understand the message even though it may be transmitted over the same medium used for broadcasting||E-mail
There are various software applications written in various programming languages and running on various platforms. The interoperability between the languages and platforms are essential for those applications to be a part of the internet. Web services are used to exchange data over computer networks.
The basic web services platform is XML + HTTP.
Extensible Markup Language (XML)
Hyper Text Transfer Protocol(HTTP)
GET /IES.htm HTTP/1.1 User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT) Host: www.iesgeneralstudies.com Accept-Language: en-us Accept-Encoding: gzip, deflate Connection: Keep-Alive
Hypertext Markup Language (HTML)
Here are the Dynamic and Static Subjects
Is the infrastructure and components that enable the communications. Some of the technologies are
What are radio waves?
Satellites use different, higher radio frequencies as follows
| Useful for mobile applications such as maritime and aeronautical uses
|Used in GPS, satellite phones|
|Capable of supporting high data rates
Has higher power
| Radar applications
Communications with space stations
|Reach over wide geographic areas
perform better under adverse weather conditions
Requires larger ground equipments
Has low power
|Full-time satellite TV networks
|Helpful for weather monitoring, air traffic control, maritime vessel traffic control, and vehicle speed detection||Primarily used for military applications|
| Higher transmission power
Requires smaller ground equipments
Reach over only smaller geographic areas
|Direct broadcast satellite services|
|Higher transmission speed
Significant information transfer
Requires smaller ground equipments
Navigation is the science of finding a way from one place to another. The present navigation systems typically uses a satellite navigation device .The navigation systems existing at present are,
|GPS||USA||Operational since 1978 and globally available since 1994, GPS is currently the world’s most utilized satellite navigation system
Uses up to 32 satellites
|GLONASS||Russia||Has global coverage
Uses 24 satellites
To be expanded into the whole globe as BeiDou-2 with 35 satellites
|GALILEO||EU||Is expected to be in full service in 2020|
|NAVIC||India||Regional network using 7 satellites
Expected to be fully operational soon
|QZSS||Japan||Regional network under development using 3 satellites|
How Position is determined?
Any radio telephone capable of operating while moving at any speed, and small enough to be carried by a person comes under the mobile communication systems. Mobile phone system was the commercially introduced in 1983. Since then mobile communication systems have witnessed an explosive growth.
Multiplexing (or muxing) is a way of sending multiple signals or streams of information over a communications link at the same time in the form of a single, complex signal. The receiver recovers the separate signals, a process called demultiplexing (or demuxing).
So, this is a technique used to send multiple signals over a single channel. It can be carried out in three dimensions: Time (TDMA), frequency (FDMA, OFDMA) and code (CDMA).
Need for multiplexing
A disadvantage of TDMA systems is that they create interference at a frequency which is directly connected to the time slot length.
1G to 5G
|1G||Analog technology||Released in 1990 to be used in GSM|
There were GSM and CDMA versions
|Enables text and multi media messages|
|2.5G||Combined with GPRS technology(a packet-based wireless communication service)||Users can take part in video conferences and interact with multimedia web sites|
|3G||Introduced higher transfer rates||Supports simultaneous voice and data
Can handle complex data such as video
Faster communication and web streaming
|4G||Mobile broadband internet services provided to external systems, such as laptops, wireless modems, etc
Additional features such as IP telephony, ultrabroadband Internet access, gaming services and HDTV streamed multimedia
100Mbps to 1Gbps speed
|Any kind of service at anytime anywhere as per user requirements|
|5G||High speed(download speeds of 20 GBs/second)
HD video quality
|Can support WWWW(wireless world wide web)
Address network congestion, energy efficiency, cost, reliability, and connection to billions of people and devices
The 5G is a technology that will run the next wave of fast mobile broadband networks in possibly two years from now. The different techniques under development are,
a. Millimetre-Wave technologies
b. Small Cell Networks
c. Massive MIMO
d. Beam Forming
e. Full Duplex
|The Datalink Layer||Ethernet and ARP||Operate on a link that interconnects nodes or hosts in the network|
|The Internet or Networking layer||IP and ICMP.||Connects independent networks to transport the packets containing the data|
|The Transport layer||TCP and UDP||Handles communications between hosts, flow control, multiplexing|
|The Application layer||HTTP, FTP, POP3, SMTP, and SNMP||Data exchange for applications|
TCP (Transmission Control Protocol)
TCP governs how to divide a message or file into packets that are transmitted over the internet and then how they are reassembled when they reach their destination.
IP(The Internet Protocol)
As per the size, capability and geographical coverage, the networks are
Quantum communication uses properties of quantum particles for a secure and fast communication system. The Quantum cryptography is one of its applications.
Internet of Things can connect devices embedded in various systems to the internet. Thus they can be controlled from anywhere. This connectivity helps to capture more data from more places, and helps in increasing efficiency and improving safety & security. Some of the applications are,
There are mainly two types of transmission – one using a physical structure and another using electromagnetic waves as carriers
Wired connected uses different types of cables. The different types are,
b.DSL (Digital Subscriber Line)
c. Optical Fibre
Uses electromagnetic waves. Satellite communications and mobile communications were discussed above. The other methods include,
b. Bluetooth Technology
e. NFC(Near Field Communication)
Microsoft’s White-fi Project
Google’s Project Loon
Face Book’s Solar Drones
Amateur radio (also called ham radio) describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication. The term “amateur” is used to specify “a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest
The amateur radio service (amateur service and amateur-satellite service) is established by the International Telecommunication Union (ITU) through the International Telecommunication Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual stations licenses with an identifying call sign.
What can I do with it?
Ham radio is basically a social hobby — whether you’re talking around town, around the world, at club meetings or conventions, you’ll be getting to know some pretty darn nice people!
In general, broadband refers to telecommunication in which a wide band of frequencies is available to transmit information. Because a wide band of frequencies is available, information can be multiplexed and sent on many different frequencies or channels within the band concurrently, allowing more information to be transmitted in a given amount of time.