Telecommunications channels for wide area networks can be owned by an organization or provided by other companies. In the United States, several companies have traditionally used a variety of communications media to create networks that can provide a broad range of communications services.
These common carriers provide Common Carriers the wide area communications networks used by most computer-using firms and individuals. They have traditionally been authorized by government agencies to provide a selected number of communication services to the public. Examples are line former Bell operating companies. General Telephone and Electronics, Western Union, and many independent telephone companies. Some common carriers specialize in selling long-distance voice and digital data communications services in high-density areas of the country and the world.
Common carriers can provide an organization needing the data communications capabilities of a wide area telecommunications network with several options. For example, an organization could use regular, voice-grade, Direct Distance Dialing (DDD), which is more expensive, slower, and less reliable than other options due to delays caused by excessive communications traffic and the noise of voice-switching circuits. Or it could sign up for a Wide Area Telephone Service (WATS) and pay a monthly fee for unlimited use of a set amount of telephone line capacity.
This would be cheaper for an organization with a lot of communications activity, but it would have the same reliability problem as DDD. Or it could lease its own communications lines (called leased lines) from telephone companies and be guaranteed exclusive use -6t-a low-noise, fast communications channel. However, this is an expensive alternative that is economically feasible only for large corporations and government agencies with massive data communications needs.
Value Added Carriers.
The other major communications carriers are companies called value-added carriers. These are third-party vendors who lease communications lines from common carriers and offer communications services to customers. Typically, messages from customers are transmitted in groupings called packets, via packet-switching networks. However, the networks of such carriers are known as Value-Added Networks (VANs), because they add “value” to their leased communications lines by using communications hardware and software and their expertise to provide not only packet switching but other telecommunications services. Value-added networks also take over the responsibility for the management of the network, thus relieving their customers of the technical problems inherent in long distance telecommunications.
Value-added carriers offer their customers or subscribers high-quality, relatively low-cost service in return for a membership fee and usage charges based on the amount of communications activity accomplished. By spreading the cost of leasing the lines among many subscribers and using the capacity of the lines intensively, they are able to sell their services at attractive prices and still make a profit. Examples of value-added companies are GTE Telenet, General Electric’s Mark Net, CompuServ, and Tymnet by Tymeshare.
Applications of telecommunications.
Telecommunications applications provide invaluable capabilities and benefits to organizations and their end users. There are groups of a large number of specific applications of telecommunications into the major categories of data communications, voice communications, text and messaging communications, information retrieval, image transmission, and monitoring and control. Telecommunications can help a firm capture and provide information quickly to end users at remote locations at reduced costs, and support its strategic organizational objectives. Let’s take a brief look now at several major categories of telecommunications applications.
Transaction Processing and Inquiry/ Response.
Telecommunications networks allow data generated by business transactions to be captured immediately by online terminals and transmitted from many remote sites to computer systems for processing. Transactions data can also be accumulated into batches, stored on magnetic disk or tape devices, and transmitted periodically to a central computer for processing from remote locations. Telecommunications networks allow business offices, banks, retail stores, and distribution centers to minimize manual data entry and expedite transaction processing, thus cutting costs, reducing errors, and improving service. In particular, Electronic Data Interchange (EDI) networks support direct electronic transmission of business transaction data I among businesses and their customers and suppliers
Electronic funds transfer (EFT.
Electronic funds transfer (EFT) systems in banking and retailing industries specialize in the capture and processing of money and credit transfers between businesses and customers. Bank telecommunications systems support teller terminals in all branch offices, and automated teller machines at locations throughout a city or region. Also supported are pay-by-phone services, which allow bank customers to use their telephones as computer terminals to electronically pay bills. Wide area networks also connect POS terminals in retail stores to bank EFT systems.
Inquiry/response systems allow end users to make inquiries about information stored in personal, departmental, corporate, and external databases and receive I immediate responses through telecommunications networks. This can provide up-to-date information for business operations and managerial decision making. End users can also access external data bank services providing economic, demographic, and financial data. to individual and corporate users.
Distributed and Cooperative Processing.
Distributed processing and cooperative processing are major applications of telecommunications. In distributed processing, information processing activities in an organization are accomplished by a network of computers interconnected by telecommunications links instead of relying on one large centralized computer facility or on the decentralized operation of several independent computers. For example, a distributed processing network may consist of mainframes, minicomputers, and microcomputers, dispersed over a wide geographic area and interconnected by wide area “networks, or they may be distributed within end user departments and work groups in local area networks.
Cooperative processing takes this concept’ one step further. It allows the various types of computers in a distributed processing network to share the processing of parts of an end user’s application. Application software packages are available which have common user interfaces and functions so they can operate consistently on networks of micro, mini, and mainframe computer systems.
With distributed and cooperative processing, local users can handle a broad range of information processing tasks. This includes data entry, database inquiry, and transaction processing, updating databases, generating reports, and providing decision support. Thus, data can be completely processed locally, where most input and output (and errors and problems) must be handled anyway, while still providing access to the resources of other computers in the network. This provides computer processing more tailored to the needs of end users and increases information processing efficiency and effectiveness as end users become more responsible for their own application systems.
Office Automation and End User Computing.
Telecommunications plays a vital role in office automation and end user computing. Local area networks allow end users in an office or other work site to share hardware, software, and data resources. Office workstations are typically tied together in local area networks with other office devices such as intelligent copiers, laser printers, and facsimile machines, and may be linked to department and corporate networks. Software packages and common databases are typically shared in such networks. Services such as electronic mail, voice mail, facsimile, and teleconferencing allow end users to send and receive messages electronically in text, voice, image, or video form. Telecommunications networks also support work group computing where end users work together on joint projects. Networks allow them to share data perform joint analysis, and integrate the results of individual efforts by members the work group.
Personal Information Services.
Personal information services are another major category of telecommunications applications. For example, companies such as CompuServe and The Source offer a variety of information services for a fee to anyone with an appropriately equipped personal computer. They offer such services as electronic mail, financial market information, use of software packages for personal computing, electronic games, home banking and shopping, news/sports/weather information, and a variety of specialized data banks. Gaining access to these services is easy if you have a personal computer equipped with a communications interface board, a modem, and a communications software package.
Another way end users can get information using an information services network is videotex. In its simplest form (teletext), videotex is a one-way, repetitive broadcast of pages of text and graphics information to your TV set. This method uses cable, telephone lines, or standard TV transmission. A control device allows you to select the page you want to display and examine. Videotex, however, is meant to be an interactive information service provided over phone lines or cable TV channels. End users can select video displays of data and information. Such as electronic Yellow Pages and personal bank checking account registers. End users can also use a special terminal or personal computer to be banking and shopping electronically.