Computer Networks and Its Types - rlmdtechnical

Computer Network

A network consists of two or four computers that are connected in a series by various means (such as printers and CD ROMS). They are connected like changing FILES or means of electrical communication. Telephone lines, radio rays are connected through satellites and illuminated rays etc. via cable on computer network.

    

There are basically three types of networks.

1. Local Area Network (LAN).

2. Wide Area Network (WAN).

3. Metropolitan Area Network (MAN)

 Local Area Network

A local area network LAN is a network that connects small areas. It is generally limited to a geographical area. Such as a writing lab school or building. Rarely LAN computers have a network of more than 1 mile.

In a particular type of LAN network, a computer is used as a file server, it stores all the software that controls the network. A computer connected to a file server is called a work station. These work stations are less powerful than file servers, and they also keep additional software on their hard drives. Only used for connecting networks on the main LAN. A computer has interfere cards. For more information on LAN networks, the process of connecting to it is done by topology cabling and hardware sector

Wide Area Network

Wide area networks connect slightly larger geographic areas such as Florida and the United States or the entire world DEDICATED TRANSOCEANIC or this type of network is used to connect satellite uplinks. WAN uses telecommunications from Florida to Tokyo within minutes. Without paying long telephone bills. WAN is complex. They use multiplexes to connect local and metropolitan networks like the Global Communication Network to the Internet.

Metropolitan Area Network

A metropolitan area network (MAN) is a network that connects users of a geographic area or a large area larger than a local area network (LAN) but smaller than a Wide Area Network (WAN) with computer resources.

A large computer network spread over a city or large university campus is called the Metropolitan Area Network or MAN. The purpose of MAN (Metropolitan Area Network) is to provide links to the Internet over a long period of time. A MAN (metropolitan area network) can usually consist of multiple LANs to form a network. This large network MAN (Metropolitan Area Network) now consists of optical fiber set-up.

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Synchronous and Asynchronous Transmission - rlmdtechnical

     

                 

  Synchronous and Asynchronous Transmission:

Data transmission by either medium is either asynchronous or synchronous. Asynchronous transmissions are typed with the keyboard as it is. Data character by character is transmitted. Therefore, the distance between the center is the distance. However, it is cheap to implement because it does not have to be secured before sending data. In the synchronous mode on the other hand, secure data is transmitted by one block. There are many factors in each block. It is suitable for remote communication, for example: card reader and printer, among computers and related devices.

The main communication device to be used today:

1. Wire pairs: These are commonly used in local telephone communication and for short-range digital data communication it is made of copper and twisted pair. The speed of data transmission is usually 9600 bits per second at a distance of 100 meters.

2. Coaxial Cable: This is a group of specially wrapped insulated wire which transfers data at a higher speed. They are made of central copper wires around which insulation happens and the copper network is located on it. It is used for a long-distance telephone line and local area network, because it has the ability to transfer data with sound resistance and faster speed.

3. Microwave: This is the use of high frequency radio signals for data transfer by space. The transmitter and receiver of the microwave system should be in line-of-sight because the radio signals are not bend. There is no facility of long-distance transmission by the microwave. Repeaters are used in the distance between 25 to 30 kilometers of transmitting and receiving end to remove the line of site problem and the power amplification of weak signals.

4. Communication Satellite: The problem of line of site and repeaters is overcome by satellite, which is today the most used data transmission medium. Communication is a microwave relay station located in satellite outer space. INSAT-B is the same type of satellite which is accessible from anywhere in India. In satellite communication, microwave signals are sent to the satellite located in the space by the transmitter located on the earth. The satellite amplifies a weak signal and translates the receiver back. Its main advantage is that it is the only microwave station visible from any point in the larger area. The data transmission rate in the microwave is 16 gigabytes per second. These are mostly used to link big cities.

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Data Transmission Modes in Computer Network - rlmdtechnical

                                        Data Transmission Modes in Computer Network

Data Transmission Modes:

There are 3 ways to transmit data from one point to the other.

1. Simplex: Communication can be in one direction in this mode, receivers receive single from transmitting device. In this way the flow of information is unidirectional, it is used very little for data communication.

                  

2. Half-duplex: In this mode the communication channel is used in both directions, but data transfer can be done in only one direction at a time. Hence the half-duplex line can alternately send and receive data.

3. Full duplex: In this mode, communication channels are used in both directions at one time. Using the full duplex line increases the capability because the required line turnaround time in the half-duplex system is overcome. The example is a telephone line.

Digital and Analog Transmission:

Data transmits from 1 point to electrical signals, which are digital or analog. Therefore, it is necessary to know the difference between analog and digital. An analog signal changes in the continuous range between power, sound, light and radio waves. On the other hand, digital signal accepts only discreditable set of values ​​in the given range. Examples are computer and computer related tools. Analog signal is measured in volts and its frequency is in hertz. Digital signal is the order of the voltage displayed in the binary form. When digital data is sent to analog medium, then the digital signal is converted to analog. The technique to convert digital signals into analog is called modulation.

Conversely, conversion to analog to digital is called demodulation. The device that is analog and digital to the digital is called modem.

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Data Communication System in Computer Network - rlmdtechnical

                 Data Communication System in computer network

       

Introduction
Today the computer is available in many offices and homes, and hence the need to share data and programs between different computer users with the promotion of data communication facility. The communication between computers has increased so that it brings the computer power out of the computer room. Today, sitting in one place can contact the computer located on a remote site through the Communication channel is there.

Data communication

In everyday life, we use some kind of communication medium. For the communication of information and messages we use telephone and postal communication systems. Similarly, data and information communication from one system to another may also be transmitted outside the geographical area. Data transmission is the dissemination of information by using some standard rules. These methods include communication of electrical signals through conductor, optical fiber and communication of optical signal by electromagnetic field.

Assume that the manager has to write some letters to all his clients. To prepare a letter, first he will have to use his PC and word processing package. If all clients are connected to PC through PC networking, then data and information, computer files and other programs are transmitted from one computer system to another in a few seconds. New forms of communication such as email and internet are only due to computer networking.

The main elements of the communication system:

The following are some of the main requirements for the functioning of any communication system-

1. A sender who prepares the message to be transmitted.

2. Message carrying medium.

3. A receiver who receives the message.

In the data communication, 4 words are mainly used in the work.

1. Data: A group of raw data that takes the form of information after processing.

2. Signal: Electrical electromagnetic encoding of data.

3. Signaling: Signaling on the communication medium.

4. Transmission: Communication of data received by signal processing.

Communication links.

The answer is Data Communication Software. This is software which facilitates interaction with other systems. Data Communication Software directs computer systems and devices to transfer data from one place to another. The method of data transformation in the form of software is called protocol.

Data transmission software or protocols do the following for transmission error-free transmission.

1. Data Sequencing: The long message to be transmitted is broken into small packets, so that the data transmission error is free.

2. Data routing: Before sending this data, the process of finding the most suitable route between the source and the destination is processed.

3.flow control: All machines in the context of motion do not have the same capability. Hence, the control of dataflow, the process of sending data between the fast sender and the slow receiver.

4. Error Control: There are two main functions of error detection and error recovery communication software to see that the data is transmitted without error.

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RRC GROUP D 2019 EXAM SYLLABUS

1/3 अंक का ऋणात्मक अंकन होगा। इसका मतलब है कि प्रत्येक गलत उत्तर के लिए 1/3 अंक काटा जाएगा।

(कंप्यूटर आधारित परीक्षा-वस्तुनिष्ठ प्रकार)

Dates of Computer Based Exam	Part	Subject	Number of questions/maximaum marks	Time duration for all parts
Notified soon	I	General Science	25/25	90 minutes (120 minutes for scrible candidate)
	II	Quantitative Aptitude(Basic Arithmetic Skill)	25/25
	III	General Intelligence and reasoning	30/30
	IV	General Awareness and current affairs	20/20

1. General Science :

इसके अंतर्गत पाठ्यक्रम 10 वीं कक्षा के भौतिक विज्ञान(physics), रसायन विज्ञान(chemistry) और जीवन विज्ञान(life Science) को कवर करेगा।

2. Quantitative Aptitude:मात्रात्मक योग्यता:

Number Systems:संख्या प्रणाली, BODMAS, Decimals(दशमलव), Fractions(भिन्न), LCM, HCF, Ratio and Proportion(अनुपात और अनुपात), Percentages(प्रतिशत), Mensuration:(क्षेत्रमिति) Time and work(समय और काम), Time and distance(समय और दूरी), Interest (Simple and Compound)(ब्याज (सरल और यौगिक)), Profit and Loss(लाभ और हानि), Algebra (बीजगणित), Trigonometry(त्रिकोणमिति), Geometry(ज्यामिति), Elementary Statics(प्राथमिक सांख्यिकी), Square roots(वर्गमूल), Age Calculation(आयु गणना), Calender and Clock (कैलेंडर और घड़ी), Pipe and Cistern(पाइप और सिस्टर्न).

4. General Intelligence and reasoning: (जनरल इंटेलिजेंस)

Analogies(समानता), number and alphabetical series(संख्या और वर्णमाला श्रृंखला), Coding and Decoding, Mathematical operations(गणितीय संक्रियाएँ ), Similaristies and differences (समानता और भिन्नता), Blood Relation(रक्त सम्बन्ध), Analytical Reasoning(विश्लेष्णात्मक तर्कशक्ति), Syllogism(न्यायवाक्य), Jumbling(बिना क्रम के मिलाना), Venn Diagrams(वेन डायग्राम), Data Sufficiency(आकड़ो की पर्याप्तता ), Statement and Conclusion(कथन और निष्कर्ष), Classification(वर्गीकरण), Decision Making(न्याय निगमन), Direction(दिशा), Statement - Argument and assumptions(कथन - तर्क और धारणाएँ), etc.

विभिन्न श्रेणियों में पात्रता के लिए न्यूनतम प्रतिशत अंक: UR- 40%, EWS-40%, OBC-30%, SC-30%, ST 25%।

DOWNLOAD RRC GROUP D 2019 EXAM SYLLABUS FOR 103769 VACANCY IN HINDI AND ENGLISH

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RRB NTPC 2019 PAPER I EXAM SYLLABUS

1/3 अंक का ऋणात्मक अंकन होगा। इसका मतलब है कि प्रत्येक गलत उत्तर के लिए 1/3 अंक काटा जाएगा।

Tier-I (कंप्यूटर आधारित परीक्षा-वस्तुनिष्ठ प्रकार)

Dates of Computer Based Exam Tier I	Part	Subject	Number of questions/maximaum marks	Time duration for all parts
NOTIFIED SOON	II	General Intelligence and reasoning	30/30	90 minutes (120 minutes for scrible candidate)
	III	Quantitative Aptitude(Basic Arithmetic Skill)	30/30
	IV	General Awareness	40/40

4. General Intelligence and reasoning: (जनरल इंटेलिजेंस)
Analogies(समानता), Compeletion of number and alphabetical series, Coding and Decoding, Mathematical operations(गणितीय संक्रियाएँ ), Similaristies and differences (समानता और भिन्नता), Blood Relation(रक्त सम्बन्ध), Analytical Reasoning(विश्लेष्णात्मक तर्कशक्ति), Syllogism(न्यायवाक्य), Jumbling(बिना क्रम के मिलाना), Venn Diagrams(वेन डायग्राम), Puzzle(पहेली परीक्षण), Data Sufficiency(आकड़ो की पर्याप्तता ), Statement and Conclusion(कथन और निष्कर्ष), Statement- Courses of action(कथन एवं कार्यवाहियां ), Decision Making(न्याय निगमन), Maps, Interpretation of Graphs(रेखांकन की व्याख्या), etc.

DOWNLOAD RRB NTPC FULL SYLLABUS IN PDF

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SSC MTS 2019 PAPER I EXAM SYLLABUS

पेपर- I में वस्तुनिष्ठ प्रकार, बहुविकल्पीय प्रश्न होंगे। प्रश्न भाग- II, III और IV के लिए अंग्रेजी और हिंदी दोनों में सेट किए जाएंगे।
1/4 अंक का ऋणात्मक अंकन होगा। इसका मतलब है कि प्रत्येक गलत उत्तर के लिए 1/4 अंक काटा जाएगा।

Tier-I (कंप्यूटर आधारित परीक्षा-वस्तुनिष्ठ प्रकार)

Dates of Computer Based Exam Tier I	Part	Subject	Number of questions/maximum marks	Time duration for all four part
02-08-2019 to 06-09-2019	I	English Language(basic knowledge)	25/25	90 minutes (120 minutes for scribble candidate)
	II	General Intelligence	25/25
	III	Quantitative Aptitude(Basic Arithmetic Skill)	25/25
	IV	General Awareness	25/25

1. English Language:(अंग्रेजी भाषा:)
Spot the Error(स्पॉट द एरर), Fill in the Blanks(फिल इन द ब्लैंक्स), Synonyms/ Homonyms(पर्यायवाची / समरूपता), Antonyms(विलोम), Spellings/ Detecting mis-spelt words(वर्तनी / गलत शब्दों की पहचान),Idioms & Phrases(मुहावरे और वाक्यांश), , Active/ Passive Voice of Verbs(क्रियाओं की सक्रिय / निष्क्रिय आवाज़), Conversion into Direct/ Indirect narration(प्रत्यक्ष / अप्रत्यक्ष कथन में रूपांतरण), Cloze Passage(क्लोएज पैसेज), Comprehension Passage(समझदारी मार्ग)

DOWNLOAD SSC MTS 2019 EXAM PAPER I FULL SYABLUSS IN HINDI AND ENGLISH

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