Chapter VIChapter VI

Data Communication: Data Communication: Delivering Information Delivering Information Anywhere and AnytimeAnywhere and Anytime

By:AP CHEN P. JOVER

BSIT - III

Defining Data CommunicationDefining Data Communication

Data communication is the electronic transfer of data from one location to another. An information system’s effectiveness is measured in part by how efficiently it delivers information, and data communication system is what enables an information system to carry out this function.

Why Managers Need to Know Why Managers Need to Know About Data CommunicationAbout Data Communication

◦Data communication has become so interwoven into fabric of corporate activity that separating an organization’s core function from the data communication systems that enable and support them is difficult. It can enhance decision makers’ efficiency and effectiveness in many ways. For example, they support just-in-time delivery of goods, which reduces inventory cost and improves competitive edge. It also enable organizations to use e-mail and electronic file transfer to improve efficiency and productivity.

How data communication How data communication technologies are used in the technologies are used in the workplace:workplace:

Employees can get training online, through virtual classrooms using data communication technologies.

Internet searches for information on products, services, and innovation immediately.

The Internet and data communication systems facilitate lifelong learning, which will be an asset for knowledge workers of the future.

Boundaries between work and personal life are less clear-cut, as data communication is more available in both homes and business.

Improved data communication technologies make Web and video conferencing easier, which can reduce the cost of business travel.

Managers need a clear Managers need a clear understanding of the following understanding of the following concepts in data concepts in data communication:communication:

The basic of data communication and networking

The internet, intranets and extranets

Wired and wireless networksNetwork Security issues and

measuresOrganozational and social effects

of data communicationGlobalization IssuesApplication of data communication

Words to note:Words to note:Bandwidth is the amount of data that

can be transferred from one point to another in a certain period of time.

Attenuation is the loss of power in a signal as it travels from the sending device to the receiving device.

Broadband data transmission multiple pieces of data are sent simultaneously to increase the transmission rate.

Narrowband Is a voice-grade transmission channel capable of transmitting a maximum of 56,000 bps.

Protocols are rules that govern data communication.

Basic Components of Data Communication Basic Components of Data Communication SystemSystem

Sender and Receiver Devices-An input/output device, or a “thin client,” is used only for

sending or receiving information and has no processing power.

-An intelligent terminal, a workstation, or a personal computer servers as an input/output devices or as a stand-alone system.

Modems-A modem (“modulator-demodulator”) is a device that

connects a user to the Internet. Not all Internet connection requires a modem; for example, wireless uses connection via access point, and and satellite users use a satellite dish. Digital subscriber line (DSL) a common carrier service, is a high-speed service that uses ordinary phone lines.

Communication Media Communication media, or channels, connects sender and

receiver devices. It can be conducted ( wired or guided) or radiated (wireless). Conducted Media provide a physical path along which signals are transmitted and include twisted-pair cable, coaxial cable, and fiber optics. Radiated media use an antenna for transmitting data through air or water. It can be point-to-point or a multi point system.

Processing ConfigurationsProcessing ConfigurationsCentralized ProcessingIn a centralize processing system, all

processing is done at one central computer. The main advantage of this configuration is being able to excersice tight control on system operation and application.

Decentralization ProcessingIn Decentralization Processing, each

user, department or division has its own computer for performing processing task. It is more certainly more responsive to user than centralized processing unit. 

Distributed Processing-Distributed Processing maintains centralized

control and decentralizes operation. Processing power is distributed among several location.

The Advantages of Distributed Processing:

Accessing unused processing power is possibleModular design means computer power can be

added or removed, based on need.Distance and location aren’t limiting It is more compatible with organizational

growthFault tolerance is improved because of

availability of redundant resources.Resources, such high-quality laser printers, can

be shared to reduce costs.Reliability is improved because system failures

can be limited to only one site.The system is more responsive to user.

Open Systems Interconnection Model

The Open Systems Interconnection (OSI) model is a seven layer architecture for defining how data is transmitted from computer to computer in a network, from the physical connection to the network to applications users run.

OSI Architecture Layers: Application Layer serves as the window through which

application access network services. Presentation Layer responsible for formatting messages

packets. Session Layer Establishes communication session between

computers Transport Layer generates the receiver’s address and ensures

packets are delivered without error, in sequence and with no loss or duplication.

Network Layer Responsible for routing. Data Link Layer Oversees establishing and controlling the

communication link. Physical Layer Electrical Connection between computers and

the transmission medium and defines the physical medium used for communications.

That’s all Thank you <3