Data Communication

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Data Communication
Data: Raw fact is a term used to
describe data:
Unprocessed value
Information: Collection of data
Unprocessed value

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Four Fundamental Characteristics
Jitter: Jitter refers to the variation in the packet arrival time.
Uneven delay in the delivery of audio and video packets.
Delivery: The system must deliver data to the correct destination.
Accuracy: The system must deliver the data
accurately.
Timeliness: The system must deliver data in a timely manner.

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Data Communication
Data communications are the exchange of data between two devices via some
form of transmission medium such as a wire cable.

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Networks
Network: A group of interconnected (via cable
and/or wireless) computers and peripherals that
is capable of sharing software and hardware
resources between many users.
1. Distributed Processing: Task is divided among
multiple computers.
Advantages:
1. Security
2. Distributed Database
3. Faster problem solving
4. Security through redundancy
5. Collaborative processing
Networking: The practice of
transporting and exchanging data
between nodes over a shared medium
in an information system.

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Networks
2. Network Criteria 1. Performance
1. Number of users
2. Type of Transmission medium
3. Hardware
4. Software
2. Reliability
1. Frequency of failure
2. Recovery time of network after a failure
3. Catastrophe
3. Security
1. Unauthorized access
2. Viruses

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Networks
3. Applications

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Protocols and standards
Protocols: A Set of Rules
1. What is communicated?
2. How it is communicated?
3. When it is communicated?
Key factors:
1. Syntax (data format and coding)
2. Semantics (control information and error handling)
3. Timing (speed matching and sequencing)
Standards: Model for development, provides
guidelines to
1. Manufacturers,
2. Ventors,
3. Government agencies
4. Other service providers

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Standards

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Standards Organization
Standards are essential in creating and maintaining an open and competitive market
For equipment manufacturers and also in guaranteeing national and international
Of data and telecommunications technologies.
Developed by cooperation among
1. Standards creation committees
2. Forum
3. Regulatory agencies.

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Standards Organization

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Standards Organization

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Standards Organization

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Standards Organization
Regulatory Agencies
FCC(Federal Communications Commission): All communications technology is subject to regulation by
this government agencies in United States
The purpose of these agencies is to protect the public interest by
1. Regulating radio
2. Television
3. Wire/cable communications
Responsibilities:
1. To review rate and service charge applications made by telegrahp and telephone providers
2. To review the technical specifications of communications hardware
3. To establish reasonable common carrier rates of return
4. To divide and allocate radio frequencies
5. To assign carrier frequencies for radio and television broadcasts.

16. Data Representation
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