Communications media networks were born with the 1926 radio sign-on of the National Broadcasting Company (NBC), signaling the dawn of a new era of both communications and culture in America. The network concept is purely abstract—even in its practical form nothing but a series of wires or satellite connections. Yet the history and influence of the broadcast networks is one of the great stories of the twentieth century, for though they did not create it, the networks did cement the process of homogenizing American culture. By 1930, for the first time America was whistling to the same tunes, laughing at the same comedians, hearing the same politicians' speeches—instantaneously. The taste and judgement of a relative few urban, Northeastern network executives set national standards of everything from dialect and language to fashion and behavior. Only when the influence of the old-line networks had faded, by the end of the century, was it truly possible to grasp the power they held over the nation for so long.
Though the number of networks has grown exponentially over the decades, with the technology of their distribution methods improving by light-years, the concept has remained the same. A network is simply a set of affiliate stations that receive programming from one central source, then beam that programming by some method, either broadcast wave or cable wire, into the eyes and ears of a waiting public.
The first major radio network, the National Broadcasting Company, debuted in November 1926 with a glittering, distinctly high-brow, multi-city broadcast. Parent company RCA announced that the new network would "provide the best program available for broadcasting in the United States." In those early days, network broadcasting wore the cloak of dignity—announcers in nightclothes and no commercials; only "indirect" advertising was allowed on the air—shrouding its very definite for-profit intentions. A rousing success, NBC was soon running two separate chains, the "Red network" and the "Blue network." Each carried its own programs to its own set of affiliate stations, though the networks sometimes combined efforts to carry an important speech or news event. Meanwhile, the "indirect" advertising rule quickly gave way to the now-familiar "commercial announcement."
By late 1927, NBC faced some competition. William Paley was the restless but ambitious 27-year-old heir to his family's cigar fortune. Having already seen radio's potential as a medium for advertising cigars, Paley jumped at the chance to enter the exciting new business of broadcasting. He bought out the struggling Columbia Broadcasting System (previously known as the United Independent Broadcasters chain, then the Columbia Phonograph Broadcasting System when that company invested heavily), signed up affiliates—and soon, NBC had itself some real, albeit impoverished competition in CBS.
The first genuine fad of the network age hit in 1929, when a pair of Chicago radio performers came to the NBC airwaves in a 15-minute nightly comedy serial called Amos and Andy. The series had been a smash in Chicago and in syndication, but it took national exposure on the NBC network to propel the series' popularity into the stratosphere. Volumes have been written about Amos and Andy : stores and theatres piped in the broadcast to keep customers from fleeing homeward at the appointed hour; you could walk down any street on a warm night and hear the broadcast wafting out open windows at every house and store; most Americans could do their own imitations of such Amos and Andy catchphrases as "I'se regusted" and "Ooh Wah! Ooh Wah!"; both local and national leaders debated whether the program was harmless comedy or racial bigotry. That such scenes were playing themselves out simultaneously in every city, village, and hamlet across the land was the first real testament to the power of this new cultural force, the broadcast network.
By 1930, the old notion of radio as a purely local force was gone forever. Network programming soon stretched from morning 'til midnight, the networks assuming ironclad contractual control over much of their affiliates' airtime. This practice guaranteed maximum "clearance" for advertisers' commercials; it coincidentally ensured that Americans would share a collective common experience each time they sat before their radios.
When vaudevillians like Jack Benny and Eddie Cantor debuted on the networks in the early 1930s, they found themselves playing to a bigger audience in a single half-hour than they would have faced in a lifetime of stage work. Likewise, listeners in Idaho or Alabama who would never have been able to see Benny or Cantor perform soon took for granted a free show—in their own homes yet—each week. When President Franklin Roosevelt took to the network air upon his inauguration in 1933, his efforts at calming a Depression-panicked populace succeeded in large measure because his words were heard instantaneously by millions of Americans.
The Mutual Broadcasting System came next, formed in 1934 as a loosely organized co-op of major independent stations like WGN in Chicago and WOR in New York. Though it eventually found itself with the most affiliates of any of the networks, Mutual never really competed with NBC or CBS in terms of ratings or budget. Attempts at launching new national chains—like comedian Ed Wynn's Amalgamated network in 1934—were notorious failures, though several smaller regional networks did operate successfully: Intercity on the east coast, Don Lee on the west.
The "big boys" continued to thrive, settling into the routines and traditions that exist to this day. The broadcast schedule consisted of news in the morning; soaps and talk shows in the daytime; more news in the evening; then big-time, big-budget entertainment at night. The September to May broadcast "season" became a tradition. Tired shows fell by the wayside; new favorites quickly took their places. A "next wave" of popular entertainers and programs—Fibber McGee and Molly, Bob Hope, Red Skelton, Edgar Bergen—took hold in the late 1930s. But it was an incident that occurred on the night of October 30, 1938 that provided the clearest demonstration yet of the broadcast networks' power over the populace.
It was only a dramatization, but later estimates report more than one million people believed it—and panicked—when Orson Welles and his Mercury Theatre on the Air presented a modern-day version of H.G. Wells' War of the Worlds, told partly through a series of staged but authentic-sounding news bulletins. People ran for their lives; police and radio station switchboards were flooded with frantic calls; at CBS headquarters, armed guards surrounded Welles' studio even as the broadcast proceeded. "War of the Worlds" was a sensation; the panic was front-page news. Ironically, it was CBS' own recent coverage of the European war crisis that had conditioned the radio audience to respond when somebody said, "We interrupt this program." By the time the Japanese attacked Pearl Harbor in December 1941, radio's real-time news capability was commonplace.
It would be impossible to overstate the effect the radio networks had on America's wartime psyche. Entertainment programs never doubted the righteousness of America's cause or the skill of its leaders; indeed, wartime events served as a creative jump-start for many series. Meanwhile, the broadcast journalism of the period successfully walked a fine line between patriotism and jingoism. True, Americans heard scant criticism of war aims or military leadership; but in terms of simple reporting of facts, the networks' news departments were in top form, managed by dedicated professionals who vowed to treat their audience equally seriously. The notion that the entire nation could gather round its radios and hear a status report on the latest battle or campaign—this was an incredible innovation, a revolution of both journalism and its public consumption.
By this time there was a "new" national network, after a government anti-trust decision forced NBC to sell one of its two chains. The network had been accused of using its decidedly second-string Blue network to stifle competition in cities that were just getting their second or third radio station. The Blue was sold to Life Savers candy magnate Edward Noble, becoming the Blue Network of the American Broadcasting Company, then simply the American Broadcasting Company, or ABC, by September 1945.
Those early post-war years were some of the grandest in network history; prime-time entertainment programs were at their slickest, big-budget best. CBS chief William Paley returned from wartime service determined to take his chain to number one; the results would resound for decades. Whereas previously advertising agencies had complete control over the programs broadcast on the network air, CBS began producing many of its own shows, then selling the advertising time. The result was a set of series (Our Miss Brooks, My Friend Irma, My Favorite Husband) that invented the modern-day sitcom. Meanwhile, having apparently despaired of developing his own big-name talent, Paley also managed to steal away many NBC favorites in the legendary 1948-49 talent raids known as "Paley's Comet." Jack Benny, Amos and Andy, Bing Crosby, Burns and Allen, Groucho Marx, Edgar Bergen, and others all defected during this period, for various reasons. CBS ruled the ratings chart for the first time in its history. And while NBC managed to hang on to Bob Hope, Fibber McGee and Molly, One Man's Family, and others, the damage was done. CBS, purposely or not, had also managed to put itself into the best competitive position in that new medium—television.
The networks' TV experimentation had started in earnest nearly a decade-and-a-half earlier; NBC had even begun a pattern of "regular broadcasts" with an extravaganza from the 1939 New York World's Fair. There was not much of an available audience and the war put a halt to most of the experimenting. By 1947, however, the networks were back at full steam. Although initially CBS stubbornly held out for color TV, featuring a system that would have rendered every current black-and-white set useless, the network finally relented when consumers proved unwilling to abandon their existing sets. Meanwhile, the fledgling DuMont network—founded and managed by the electronics manufacturer of the same name—seemed to be in a good position to overtake ABC as the "third network" in the new medium. Without its own radio chain to provide talent and financial support, however, that goal proved unattainable.
None of the big radio stars were willing to take the plunge at this early date, but advertisers were testing the television waters. Even as the papers were full of stories about Jack Benny's switch of radio networks, a definite trend developed: in cities where viewers could choose, TV became the favorite. NBC television found its first bona-fide hit in Milton Berle's Texaco Star Theater in 1948. Viewing outpaced radio listening in city after city by 1949.
Radio ratings didn't collapse all at once; instead, the sun set agonizingly slowly over the networks' glory days. A Korean War freeze on some manufacturing put the brakes on the spread of television during the early 1950s, to interesting effect: even as television ruled the nation's cities, the outlying areas were still totally dependent on radio. Jack Benny, Bob Hope, Burns and Allen, Red Skelton, and others made the jump to television early in the new decade; Jackie Gleason and Lucille Ball joined Milton Berle as the first genuine sensations the new medium had produced on its own. To be sure, network radio was enjoying a creative resurgence during this period; daring new series like Dragnet and Gunsmoke were a breath of fresh air to viewers.
The radio advertising market had collapsed. The city audience had deserted the medium in droves; most remaining listeners joined the exodus when mass manufacturing resumed in 1953. By 1955, of the legendary comedians who had ruled the airwaves for 25 years, only Edgar Bergen remained on the radio. Nighttime drama was all but dead; NBC, in particular, began experimenting with the long-form news/talk format; network "news on the hour" was an innovation during this period. November 25, 1960 is often referred to as "the last day of network radio": on that Friday after Thanksgiving, CBS broadcast the final installments of everything from Ma Perkins to Amos and Andy. The last two network dramas came to an end in 1962. (The long-running detective opus Yours Truly, Johnny Dollar was the last radio network drama). Network television was now the unchallenged king of America's living rooms, a position it would hold for another two decades.
The era was a remarkably stable one for the industry. The DuMont network folded in 1956, but NBC, CBS, and ABC thrived. Their access into the nation's homes—and consciousness—during this period was unparalleled. The networks and their product influenced fashion—everything from coon-skin caps to Capri pants and bouffant hairdos; language—expressions as familiar as "And away we go" and "Here comes the judge" began as TV catchphrases; and politics—television news led the way in questioning America's involvement in Vietnam, and while few Americans had access to the Washington Post, the networks' coverage of Watergate made it into every home in the nation. As NBC and CBS spent the decades fighting it out for first place in the ratings, the networks became adept at turning public fancy into inescapable fad: Westerns gave way to the rural comedies of the early 1960s; series such as The Beverly Hillbillies in turn surrendered to the popularity of All in the Family and other socially relevant comedies of the early 1970s. ABC (which for decades had been nicknamed "Almost a Broadcasting Company") was catapulted to its first-ever reign at the top on the strength of series like Charlie's Angels and Three's Company in the mid-1970s. As late as 1979, the networks could manage to draw nearly 100 percent of the available viewing audience on any single night.
In 1975 the Home Box Office pay channel took to the air via satellite, its signal beamed into homes via the local cable systems whose previous service had been providing clearer signals of faraway broadcast stations. The idea of receiving unedited, recent theatrical films via cable—even for a small fee—proved popular and profitable; other entrepreneurs quickly took the hint. Atlanta businessman Ted Turner was soon uplinking the signal of his UHF independent station; with characteristic modesty, Turner called his baby the "Superstation"—and it soon found a coast-to-coast audience. Turn-er's Cable News Network debuted in 1980. Although the broadcast networks sneered, their contempt soon turned to outright fear.
By the mid-1980s, dozens of cable networks had carved profitable niches for themselves. The television audience that had contented itself for decades with three or four channels suddenly had ten times that many from which to choose: everything from evangelist Pat Robertson's Christian Broadcasting Network to the all-sports ESPN to the all-music MTV—perhaps the first cable network to spark its own generational and cultural revolution.
To be sure, the audience for each of these cable networks was tiny, the barest fraction of the audience for even the lowest-rated traditional network program. But the combined weight of cable viewership sent the old-line networks' ratings into an irreversible downward spiral by the mid-1980s. Their consignment to irrelevance was neither immediate nor quick; like the radio networks before them, the television chains found themselves dying slow, lingering deaths, with few options for salvation. A 1990s cable series, South Park, was considered a smash—featured on the cover of Newsweek, the talk of its generation, and a merchandising bonanza. Yet it drew barely two million viewers per week. True, they were the young, affluent viewers advertisers craved; yet there simply were not enough of them to make the program a success on a traditional broadcast network. It was the great paradox: the old networks' audience was still vast; yet by continuing to program for a mass, homogenous audience in the age of niches and demographic targeting, the networks had effectively ceded their long-standing role as a guiding cultural force. The addition of several new broadcast networks—Fox in the 1980s, UPN, WB, and Pax in the 1990s—served to further disperse the former mass audience.
The networks' decline had no lesser consequences than their rise. The audience became so fragmented, the number of viewing choices so great, that the concept of the great national audience simply vanished: no more universally understood catchphrases, no more monster-hit series, at least not in the old sense. The youngest generation didn't even remember the day of three or four channels; by the end of the twentieth century, even the network concept itself was permanently endangered.
Cable, too, was threatened by rapidly advancing technology. Suddenly, it was possible for consumers to bypass the network setup entirely, and have their own individual choice of program services beamed directly into their homes by satellite. The technology had existed for years, in bulkier and more expensive form, but the direct-satellite industry exploded in the late 1990s. Suddenly there were 500 or more channel choices, a development that served to further fragment the viewing audience. Many cable networks even launched second (or third or fourth) satellite-carried program services, carving their audience niches into even smaller pieces. Meanwhile, the booming satellite industry was the greatest threat yet to the traditional broadcast networks. Most satellite systems bypassed the local network affiliates entirely, in the process rendering the broadcast network apparatus, completely irrelevant.
Indeed, at the end of the century, the once-miraculous notion of radio or TV signals wafting through the air into American homes seemed superfluous, even foreign, to the youngest generation of television viewers. Truly, the era of the networks' cultural dominance was over. However, the era's legacy will live on as long as radio or television, in whatever form, continues to be a factor in American cultural life.
Barfield, Ray E. Listening to Radio, 1920-1950. Westport, Connecticut, Praeger, 1996.
Berke, Sally. When TV Began: The First TV Shows. New York, CPI, 1978.
Brooks, Tim and Earle Marsh. The Complete Directory to Prime Time Network and Cable TV Shows. New York, Ballantine Books, 1995.
Campbell, Robert. The Golden Years of Broadcasting: A Celebration of the First 50 Years of Radio and TV on NBC. New York, Scribner, 1976.
Douglad, George H. The Early Days of Radio Broadcasting. Jefferson, North Carolina, McFarland, 1987.
Dunning, John. On the Air: The Encyclopedia of Old-Time Radio. New York, Oxford University Press, 1998.
Hilmes, Michelle. Radio Voices. Minneapolis, University of Minnesota Press, 1997.
Networks are particular types of human relations or technological creations, sometimes compared to systems and webs, that establish unique exchanges between human beings and spaces. Since the 1700s, and especially since the invention of the Internet, networks have been subject to scientific analysis. Insofar as they define or influence human behavior they may be subject to ethical assessment.
Network Types and Influences
In mathematics a network is commonly defined as a directed graph with vertices (or nodes) and weighted edges (also called arcs or links). As such networks come in different structural types: bus, ring, star (hub and spoke), mesh (web), and more (see Figure 1). Networks can be further distinguished in terms of numbers of vertices and edges. Each structure has its own intrinsic properties, which can be enhanced or modified by giving different weights or strengths to the various links, as when (for instance) one link in a star network is weighted more heavily than another.
Throughout history networks have provided the foundation and infrastructure for humans to conduct wide-ranging economic and social activities. Well-known physical networks in which nodes correspond to locations in space and links to appropriate connections with associated flows include transportation and communication networks. Transportation networks have evolved over the centuries through advances in science and technology and come in a myriad of forms: road, rail, air, or waterway, with a variety of associated modes of travel. They traverse physical distances to facilitate business transactions, military conquest, and visits among colleagues, clients, friends, and family, as well as enabling people to explore new areas and to expand horizons. Communication networks, in turn, allow exchanges of information not only within communities but also across regions and national boundaries by means of postal services, telephones, radio, television, computers, satellites, and microwaves that carry written messages, video, and/or electronic data. Energy networks, as another example, provide the necessary fuel to support many transportation and communication network transactions.
In addition, more abstract networks such as financial networks, a variety of logistical networks (e.g., supply chains), as well as knowledge and social networks (based on transportation and communication networks) play new and not yet completely understood roles in societies and economies. The reliability, efficiency, and accessibility of such networks enhance production and distribution, facilitate the exchange of information and knowledge, and add to the diversity and richness of goods and services. At the same time, the structure of such networks and the connectivity provided by them may yield insights and advantages for particular individuals and organizations.
Organizations today, be they local, regional, national, or global in scope and as diverse as businesses, educational institutions, or governments, are highly dependent on networks, which are becoming increasingly interrelated. Indeed, individuals may now be able to conduct financial transactions electronically and to shop globally from their places of employment and have the products delivered to the desired destinations. They may also, in certain circumstances, be able to work from home or other chosen locations depending on the management of the underlying networks, their utilization and availability, and the auxiliary ethical character of network designs, accessibility, and usage.
Fascinatingly, the structure of social relationships may also be represented as a graph/network, and the study of social relationships has given rise to the multidisciplinary topic of social network analysis. In such a context, important measures include the number of connections for an individual (represented by nodes in the network), the strength of these connections, the centrality of various individuals, and the existence of cliques and subgroups. Moreover, one can calculate the degrees of separation. Clearly, the existence and structure of social networks also affects the usage of physical networks, notably transportation and various communication networks. The latter networks, in turn, play pivotal roles in the evolution of social networks.
The Science of Networks
The topic of networks and network management dates to ancient times with classical examples including the publicly provided Roman road network and the time-of-day chariot policy, whereby chariots were banned from the ancient city of Rome during particular times of the day (Nagurney 2000). The topic of networks as a subject of scientific inquiry originates in a 1736 paper by the Swiss mathematician Leonhard Euler (1707–1783), which is considered the earliest paper on graph theory, where a graph in this context is meant as an abstract or mathematical representation of a system by its depiction in terms of vertices (nodes) and edges (or arcs) connecting various pairs of vertices.
Interestingly, not long thereafter, François Quesnay (1694–1774), in his Tableau économique (1758), conceptualized the circular flow of an economy as a network. Gaspard Monge (1746–1818), who had worked under Napoleon Bonaparte in providing the infrastructure support for his army, published what is probably the first paper on the transportation network model in 1781. Much later, and following the first book on graph theory by Dénes König in 1936, works by the economists Leonid V. Kantorovich (1939), Frank L. Hitchcock (1941), and Tjalling C. Koopmans (1947) considered the network flow problem associated with the classical transportation problem. Thus the study of network flows, primarily in a transportation context, preceded the development of even optimization theory and such elegant algorithmic techniques as the simplex method (see Dantzig 1948).
Indeed, the emergence and evolution of a plethora of physical networks over space and time, coupled with realizations of the importance of abstract networks, and the effects of human decision-making on networks through their utilization and management, has given rise to the development of rich and powerful theories that are rigorous, scientific, and network-based. The novelty of networks lies in that they are pervasive and fundamental and provide the fabric for the connectivity of societies and economies. At the same time, methodologically, network theory has developed into a powerful and dynamic medium for abstracting complex network-based problems. Many contemporary networks (including the Internet) are characterized by a large-scale structure, complexity of interconnections and interrelationships, congestion, and distinct behavior of the users. One illustrative phenomena is the Braess paradox (1968), in which the addition of a new road in a transportation network—or a link in a communications network such as the Internet (see Korilis, Lazar, and Orda 1999)—makes all users of the network worse off. Methodologies for the formulation and analysis of network systems are thus of wide practical significance (see Ahuja, Magnanti, and Orlin 1993; Nagurney 1999; Nagurney and Dong 2002).
Today it is possible, through advances in scientific models, theories, and computational tools, to predict optimal routes on networks from different origins to destinations both from a system-optimized perspective, in which there is a central controller of the network flows, and from a user-optimized one, in which users of the network select their optimal routes in what may be viewed as a selfish manner (see Beckmann, McGuire, and Winsten 1956; Dafermos and Sparrow 1969; Nagurney 1999; Nagurney and Dong 2002). In addition, it is possible to optimize financial portfolios from a network perspective (Nagurney and Siokos 1997; Nagurney 2003), to predict the profit-maximizing production and shipment patterns between tiers of network decision-makers (Nagurney and Dong 2002), and to even determine information flows in an organization (Wu et al.).
More recently, social networks have been integrated with economic networks, in the form of supply chains, through the theory of supernetworks (see Walkobinger and Nagurney 2004) in order to capture relationship levels as flows in addition to product shipments. Such complex networks not only synthesize and integrate the structure of the underlying social and economic relationships but also capture human behavior and decision-making and the associated impacts. Moreover, the dynamics of the interactions between the various decision makers as well as how their relationships evolve over time (and how they compete and/or cooperate) can be modeled, along with the optimal product flows and prices.
There are nevertheless many questions of ethical significance concerning networks, their operation and management, and their accessibility and usage.
Accessibility and Ethics
In regard to accessibility, consider transportation and communication networks. Accessibility concerns the design of the network itself. The number of nodes and the number of links connecting the nodes determine the network topology, whereas the quality of the links affects the ultimate accessibility and usage. For example, well-built roads will support travel and trade, whereas an impoverished transportation network infrastructure can seriously impede development and growth. At the same time, the availability of alternative modes of transportation may enhance employment because workers can reach their (possible) places of work. Similarly, those who cannot drive or cannot afford car ownership may be able to use cost-appropriate transportation modes (if such are available).
The interrelationships between networks in this context also have ethical implications. For example, it is now well-established that transportation and especially vehicular transportation on congested urban networks not only results in a loss of productivity but has serious consequences for the environment because of pollution emissions (Nagurney 2000). Moreover, these emissions are not necessarily local but are often transported over political boundaries. Hence, the choices made by an individual in terms of route/mode selection can negatively affect distant populations. Although there may be economic approaches to ameliorating some of these negative effects through, for example, tolls or pollution charges, there may also be incentives put in place that appeal to humans' individual sense of ethics.
In terms of communication networks, notably the Internet, the accessibility issue has received a great deal of attention especially from a variety of government organizations. Indeed, terms such as the digital divide have become part of the popular lexicon. In certain fields, particularly science, the essentialness of accessibility to the Internet for research, information, and knowledge dissemination is well known (Alberts; Newman 2001). Less emphasized and as important is to increase the connectivity in less-developed and developing nations, which not only may have poor communication infrastructures but may suffer from substandard energy networks, as well.
Not only do scientists benefit from accessibility to communication networks such as the Internet, but educational systems throughout the globe can only be enriched through reliable and efficient Internet connections.
Usage and Ethics
Increased access to interconnected networks also raises ethical issues. For example, given that information on individuals can be retrieved in seconds by anyone with appropriate computer connections, there are serious questions concerning privacy of the information and the right of individuals to check the correctness of the data and information concerning themselves. Moreover, the regulation of the content of what is circulating on the Internet, given its huge and immediate reach, is a subject of both ethical and legal importance. In addition, such computer-based crimes as hacking and computer piracy are examples of illegal and unethical usage of communication networks. Such activities can have serious financial as well as personal consequences (see, e.g., UNESCO).
The Internet, by helping to span the globe and enhancing people's right to communicate, has given freedom to many voices. It has played a major role in social and economic transformations and has helped in the internationalization of trade, especially through electronic commerce and the globalization of nations' economies. In addition, the Internet has allowed new social networks to evolve, oftentimes between individuals and among groups who have never even met face-to-face. Freedom, however, must come with responsibility, a sense of ethics, and solid judgment of the consequences of one's actions on others. Never has the subject of networks and ethics been more timely and relevant.
Ahuja, Ravindra K.; Thomas L. Magnanti; and James B. Orlin. (1993). Network Flows: Theory, Algorithms, and Applications. Englewood Cliffs, NJ: Prentice Hall.
Barabási, Albert-Laszló. (2002). Linked: The New Science of Networks. Cambridge, MA: Perseus.
Braess, Dietrich. (1968). "Über ein Paradoxon der Verkehrsplanung" [On a paradox of traffic planning]. Unternehmenforschung 12: 258–268.
Dafermos, Stella C., and Frederick T. Sparrow. (1969). "The Traffic Assignment Problem for a General Network." Journal of Research of the National Bureau of Standards 73B(2): 91–118.
Dantzig, George B. (1948). "Programming in a Linear Structure." Washington, DC: Comptroller, U.S. Air Force.
Euler, Leonhard. (1736). "Solutio problematis ad geometriam situs pertinentis" [The solution of a problem relating to the geometry of position]. Commetarii Academiae Scientarum Imperialis Petropolitanae 8: 128–140.
Hitchcock, Frank L. (1941). "The Distribution of a Product from Several Sources to Numerous Localities." Journal of Mathematics and Physics 20: 224–230.
Kantorovich, Leonid V. (1939). Mathematischeskiye metody organizatsiyi i planirovanya proizvodstva. Leningrad: Publication House of the Leningrad State University. Translated in 1960 as "Mathematical Methods in the Organization and Planning of Production." Management Science 6: 366–422.
König, Dénes. (1936). Theorie der Endlichen und Unendlichen Graphen [Theory of limited and unlimited graphs]. Leipzig, Germany: Teubner.
Koopmans, Tjalling C. (1947). "Optimum Utilization of the Transportation System." In Proceedings of the International Statistical Conferences. vol. 5: 136–145. Reprinted in Econometrica 17 (supplement) (1949): 136–145.
Korilis, Yannis A.; Aurel A. Lazar; and Ariel Orda. (1999). "Avoiding the Braess Paradox in Non-cooperative Networks." Journal of Applied Probability 36(1): 211–222.
Monge, Gaspard. (1781). "Mémoire sur la théorie des déblais et des remblais" [Memorandum on the theory of excavation and embankment construction]. In Histoire de l'Académie Royale des Sciences, avec les Memoires de Mathematique et de Physique, pour la Meme Annee. Paris: Tires des Registres de Cette Academie.
Nagurney, Anna. (1999). Network Economics: A Variational Inequality Approach, 2nd edition. Boston: Kluwer Academic.
Nagurney, Anna. (2000). Sustainable Transportation Networks. Cheltenham, UK: Edward Elgar.
Nagurney, Anna, ed. (2003). Innovations in Financial and Economic Networks. Cheltenham, UK: Edward Elgar.
Nagurney, Anna, and June Dong. (2002). Supernetworks: Decision-Making for the Information Age. Cheltenham, UK: Edward Elgar.
Nagurney, Anna, and Stavros Siokos. (1997). Financial Networks: Statics and Dynamics. Heidelberg, Germany: Springer-Verlag.
Quesnay, François. (1895 ). Tableau économique. British Economic Society. Reprint, with an introduction by H. Higgs.
Van Alstyne, M., and E. Brynjolfsson. (1996). "Could the Internet Balkanize Science?" Science 274(5292): 1479–1480.
Walkobinger, Tina, and Anna Nagurney. (2004). "Dynamic Supernetworks for the Integration of Social Networks and Supply Chains with Electronic Commerce: Modeling and Analysis of Buyer-Seller Relationships with Computations." Netnomics Amherst: Virtual Center for Supernetworks, Isenberg School of Management, University of Massachusetts at Amherst.
Alberts, Bruce. "Science and Human Needs." President's address, 137th annual meeting of the National Academy of Sciences, Washington DC, May 1, 2000. Available from http://www.nationalacademies.org/president/alberts.html.
United Nations Educational, Scientific and Cultural Organization (UNESCO). "UNESCO and an Information Society for All." Available from http://www.unesco.org/webworld/telematics/gis.htm. Published in 1996.
Wu, Fang; Bernardo A. Huberman; Lada A. Adamic; and Joshua R. Tyler. "Information Flow in Social Groups." Information Dynamics Laboratory, Hewlett-Packard Labs, Palo Alto, CA. Available from http://www.hpl.hp.com/shl/papers/flow/. Published in 2003.
Gregarious people tend to have a wide circle of friends; they enjoy social contact, like to be with people, and have a knack for connecting with others and then staying in touch. When they need something they tend spontaneously to think of a person in their circle who might help or might know someone else who could. Similarly, if they hear of something that might interest a friend, they act. They make a quick call…. This type of temperament and way of behavior is as old as humanity. And successful use of contacts hasn't gone unnoticed either. There is a common saying to the effect that "it's not what you know but who you know"—which attempts to highlight the greater importance of social connectedness than that of abstract knowledge. A very popular bestseller by Dale Carnegie, the motivational teacher and author, was his 1936 title How To Make Friends and Influence People. It was probably not the first book attempting to teach what comes naturally to some. Around about the late 1970s and early 1980s, a time when the baby boom generation was moving into the workforce, the term "networking" appeared. Like Carnegie's method, it was intended to emulate gregarious behavior on purpose and with the goal of gaining benefits in business. Networking has always had an ambiguous character. When it is practiced openly, and the net-worker's desire to make useful business contacts is up front and visible, it is a kind of salesmanship. Quite a few people practice networking openly. Recipients of such attention are not offended; it is, in fact, slightly flattering to be considered important enough to be courted. When the contact-work is disguised as seeking social links or friendship, however, networking has a faintly calculating and exploitive connotation which, once it becomes known, will have the opposite effect from the one intended.
A rather benign form of networking is "social networking" that people engage in when they have problems finding a mate. This often takes the form of self-exposure in environments likely to have a fair supply of eligible partners. People start going to church again, take classes, or take up communal hobbies and sports. Very often others also participating in such activities are also seeking company. Interactions enable people to get to know each other and to test the water. Linkages are formed because of mutual attraction. Both business and social networking have been formalized, the latter in such interesting forms as "five-minute dating" services.
Business networking, certainly in its earlier stages of development, was viewed by many as a valuable new discovery, a kind of leverage with small inputs that have large consequences. But networking is equivalent to marketing a corporate identity, to "institutional advertising," in that nothing specific is being sold except the net-worker's existence—and this to one person at a time. Networking requires concentrated attention, record keeping, and the cultivation of the network—hence it costs time and money. If the networker, realizing the high costs, narrows the field of contacts to individuals deemed more likely to be helpful in the future, networking loses one of its benefits, namely the discovery of unexpected and serendipitous helpers. The more narrowing is introduced, the more networking comes to resemble traditional forms of prospecting, selling, or simply acting in an entrepreneurial manner.
Networking has three basic components: 1) making contacts deliberately; 2) recording contacts made; and 3) cultivating the network. Making contacts means willingness to engage people in conversations (e.g., on airplanes, at parties, at concerts) and to expose oneself to others by visiting events, particularly those likely to yield good links. Showing interest in others, paying attention to them, and engaging in give-and-take are, of course, vital. Business conferences and expositions are a good venue for meeting potentially helpful people in a business context; the active networker will "work the booths" and get to know lots of people. Keeping records is central because relatively brief contacts will fade from the mind, but notes in a database will bring back the memories. The activity requires time and effort. Calling cards must be keyed in or annotated on the back. The use of keywords for contact retrieval is helpful. Cultivating contacts means to renew them from time to time. The more is known about the contact the easier it is to do this. The networker can send contacts clippings that may interest them or call them with some news of interest and thus maintain the linkage. Children's or the contact's birthdays afford opportunities. And so on. The key point regarding cultivation is that networking is a two-way process between any two nodes. The networker must strive to be of help to the contact in order to merit help, down the ways, if it should ever be needed. A natural part of doing this right is to observe the usual courtesies: people should neither be neglected nor smothered and badgered.
Networking in the Internet
Age Not surprisingly, the greatest network of them all, the Internet, has been harnessed to the service of networking, both social and business. In the business networking category, for example, networking clubs have made an appearance. Among them are ItsNotWhatYouKnow (INWYK), LinkedIn, Ryze, and ZeroDegrees. According to Catherine Seda, writing in Enterpreneur, "It's simple to join, and most clubs are free or have a free level of access. Complete the registration form, invite your colleagues to join, and get on each other's 'connections' lists. The bigger your network, the greater your referral opportunities are, because members click on your contacts to see who you know."
Concerning networking in general, the last word on the subject ultimately belongs to George Ball, once Undersecretary of State in the Kennedy and Johnson Administrations. Ball famously said: "Nothing propinques like propinquity."
Horowitz, Alan S. "Social Software: Corporate and Web-based networking software helps people make critical business connections." Computerworld. 19 September 2005.
Lemaire, Barbara C. "52 Tips for Networking Success." New Mexico Business Journal. March 2006.
"Networking." Chartered Management Institute: Checklists: Marketing Strategy. October 2005.
"No Business in Social Networking." eWeek. 4 May 2004.
Pierce, Sarah. "Meet market." Entrepreneur. August 2005.
Seda, Catherine. "The Meet Market: Looking for new business leads? Networking clubs on the web make it easy." Entrepreneur. August 2004.
Shewmake, Brad. "Secrets of Successful Networking." InfoWorld. 3 July 2000.
Wright, Rob. "Before You Make That Next Hire …—Firm finds advisers in unlikely places." VARbusiness. 21 February 2005.
Social networks are social relationships between two or more people (known as nodes) who have developed some kind of tie with each other (Wasserman and Faust 1994). “The social network perspective focuses on relationships among social entities; examples include communications among members of a group, economic transactions between corporations, and trade or treaties among nations” (Wasserman and Faust 1994, p. i). People use social networks to acquire new information, exchange information, find jobs, learn about new opportunities, and exchange new ideas, among other purposes. Individuals can acquire social ties in a number of social settings such as jobs, social organizations, religious organizations, political organizations, sports groups, a group of friends, and so on.
Wasserman and Faust (1994, p. 4) argue that the social network perspective should take into account the following:
- Actors and their actions are viewed as interdependent rather than independent, autonomous units.
- Relational ties (linkages) between actors are channels for transfer or “flow” of resources (either material or nonmaterial).
- Network models focusing on individuals view the network structural environment as providing opportunities for or constraints on individual action.
- Network models conceptualize structure (social, economic, political, and so forth) as lasting patterns of relations among actors.
In general, social networks are seen as providing individuals or larger groups or social entities with positive outcomes as a result of the information and social support the individuals who belong to a specific social network receive. Those who belong to a social network enjoy the advantages of social capital. The concept of social capital (Loury 1977; Bourdieu 1986; Coleman 1988) has been used to account for the advantages that network members accrue as a result of their inclusion.
According to the organizational literature, the position of the actors in a network or the network structure in which those ties are embedded would in most cases dictate the extent to which belonging to a social network can provide individuals with new information and opportunities that can help them perform better in society or facilitate their upward socioeconomic mobility. For example, central actors can influence how information gets distributed to other members in the network, referred as network centrality (Wasserman and Faust 1994). Also, a key actor could control the information that flows between two independent groups, a situation known in the organizational literature as structural holes (Burt 2001). Also, network homogeneity or structural equivalence (if ties are similar), or network heterogeneity (if ties are different), can influence the kinds of advantages or disadvantages network members might experience as a result of their membership in the network (Wasserman and Faust 1994).
Besides the structure and/or the position in the network, tie strength could also dictate the network’s effectiveness. Mark Granovetter, first in his work The Strength of Weak Ties and later on in his book Getting a Job, revolutionized the organizational literature by introducing the concept of the “strength of weak ties” (Granovetter 1973, 1995). He argues that belonging to an open network and having access to weak ties (or acquaintances) can provide individuals with new valuable information that can help them get better jobs. Even though one might not have a strong relationship with those individuals, they are able to share new knowledge and important information that otherwise would not be available in a closed network with mostly strong ties. Those who belong to closed networks with mostly strong ties are considered to be at a disadvantage given the limited amount of information shared by the members of such networks. Studies on racial segregation (Massey and Denton 1993) have suggested that members of closed networks or cliques have less chance to learn about new important information and that the information that flows in those networks tends to be redundant and inefficient.
According to Granovetter (1982), strong ties and closed networks could be advantageous only for those who face risk and high levels of uncertainty. However, studies of entrepreneurial networks among Asian immigrants in the United States have shown that for certain immigrant groups, having access to strong ties in a closed network of highly educated or high status individuals who share high levels of socioeconomic status tend to receive the social support necessary to be successful as new entrepreneurs (Light, Sabagh, Bozorgmehr, and Der-Martirosian 1994).
Also, the distinction between kin and nonkin ties is fundamental to the understanding of how social networks operate (Adams 1967; Fischer 1982). While individuals can pick their neighbors, friends, or coworkers, they cannot pick the members of their kin (Wierzbicki 2004). In addition, kin ties are everlasting, while any other kind of ties can be dropped at any time (Wierzbicki 2004). Kin ties can be extremely important because they can provide assistance in times of crises, while any other kind of tie might not.
Neighbors can also be important ties in social networks depending on the relationship between neighbors. According to Fischer (1982), neighbors tend to be similar in race and socioeconomic status, and the individual has the freedom to develop or avoid strong ties with neighbors. Proximity is the most important factor in ties between neighbors. Such proximity can become important because it allows for social interactions that could be more difficult to achieve with other kinds of ties.
Today, technological advances such as the development of personal computers, Internet access, e-mail, and cell phones has provided advantages and disadvantages to the development of social ties. While individuals can communicate more often through e-mail and share more information, physical contact has become less frequent. People who are far from each other, even on the other side of the planet, can be in touch every day through the Internet, while those who work together next to each other can also communicate through the computer, limiting their physical and social contact.
Organizational and management literature also uses social networks as the basis for the distribution of information, which could lead to the spread of ideas and innovations and the development of new enterprises (Coleman, Katz, and Menzel 1957; Burt 1987).
Several topics have been studied using the social network perspective approach, including occupational mobility (Breiger 1981, 1990), networks of friends in urban cities (Fischer 1982), the world political and economic system (Snyder and Kick 1979), markets (Berkowitz 1988; White 1981), six degrees of separation (Watts 2003), social networks and international migration (Wierzbicki 2004), and the networks of elite Americans and politicians (Domhoff 1998), among many other. Most people around the world are now aware of the power of social networks and how knowing someone or meeting someone could change one’s future. Advances in technology are helping this task, greatly facilitating communication among actors from any part of the world.
SEE ALSO Bureaucracy; Crony Capitalism; Network Analysis; Networks, Communication; Organization Theory; Organizations; Social Capital
Adams, Bert N. 1967. Interaction Theory and the Social Network. Sociometry 30: 64–78.
Berkowitz, S. D. 1988. Markets and Market-Areas: Some Preliminary Formulations. In Social Structures: A Network Approach, eds. B. Wellman and S. D. Berkowitz, 261–303. Cambridge, U.K.: Cambridge University Press.
Bourdieu, P. 1986. The Forms of Capital. In Handbook of Theory and Research for the Sociology of Education, ed. J. G. Richardson, 241–258. New York: Greenwood Press.
Breiger, R. L. 1981. The Social Class Structure of Occupational Mobility. American Journal of Sociology 87 (3): 578–611.
Burt, Ronald S. 1987. Social Contagion and Innovation: Cohesion versus Structural Equivalence. American Journal of Sociology 92 (6): 1287–1335.
Burt, Ronald S. 2001. Structural Holes versus Network Closure as Social Capital. In Social Capital: Theory and Research, eds. Nan Lin, Karen S. Cook, and Ronald S. Burt, 31–56. New York: Aldine de Gruyter.
Coleman, James S., E. Katz, and H. Menzel. 1957. The Diffusion of an Innovation among Physicians. Sociometry 20: 253–270.
Coleman, J. S. 1988. Social Capital in the Creation of Human Capital. American Journal of Sociology 94: S95-S120.
Domhoff, G. William. 1998. Who Rules America? Power and Politics in the Year 2000, 3rd ed. Mountain View, CA: Mayfield.
Fischer, Claude S. 1982. To Dwell among Friends: Personal Networks in Town and City. Chicago: University of Chicago Press.
Granovetter, Mark. 1973. The Strength of Weak Ties. American Journal of Sociology 78 (6): 1360–1380.
Granovetter, Mark. 1982. The Strength of Weak Ties: A Network Theory Revisited. In Social Structure and Network Analysis, eds. Peter V. Marsden and Nan Lin, 105–130. London: Sage.
Granovetter, Mark. 1995. Getting a Job: A Study of Contacts and Careers. Chicago: University of Chicago Press.
Light, Ivan, Georges Sabagh, Mehdi Bozorgmehr, and Claudia Der-Martirosian. 1994. Beyond the Ethnic Enclave Economy. Social Problems 41: 65–79.
Loury, G. C. 1977. A Dynamic Theory of Racial Income Differences. In Women, Minorities and Employment Discrimination, eds. P. A. Wallace and A. M. LaMond, 153–186. Lexington, MA: Heath.
Massey, Douglas S., and Nancy A. Denton. 1993. American Apartheid: Segregation and the Making of the Underclass. Cambridge, MA: Harvard University Press.
Snyder, D., and E. Kick. 1979. Structural Position in the World System and Economic Growth 1955–1970: A Multiple-Network Analysis of Transnational Interactions. American Journal of Sociology 84 (5): 1096–1126.
Wasserman, Stanley, and Katherine Faust. 1994. Social Network Analysis: Methods and Applications. Cambridge, U.K., and New York: Cambridge University Press.
Watts, Duncan J. 2003. Six Degrees: The Science of a Connected Age. New York: Norton.
White, H. C. 1981. Where Do Markets Come From? American Journal of Sociology 87: 517–547.
Wierzbicki, Susan. 2004. Beyond the Immigrant Enclave: Network Change and Assimilation. New York: LFB Scholarly Publishing.
Nadia Y. Flores
Computer networks consist of multiple computers and other electrical devices linked together. Networks are classified as local area networks (LANs) or wide area networks (WANs). The difference between LANs and WANs is usually determined by the length of the network. Generally, a LAN's distance includes only several hundred yards. LANs reside mostly in offices, work areas, classrooms, one building, or within several buildings. WANs exist over many miles, across several cities, and even around the world. WANs are multifaceted and complex networks. They require many devices that connect different computers using diverse communication services. WAN communication speed, reliability, and connectivity are more challenging to manage than those of a LAN.
HISTORICAL ACHIEVEMENTS IN COMMUNICATION AND TRANSPORTATION
Networks were developed as a communication method between computers at remote sites. They trace their roots back to nineteenth-century communication and transportation historical achievements. In America, people have always strived for faster travel and communication systems, particularly between the East and West Coasts. These systems included technology and experiments of varying complexity. For example, the Pony Express operated between 1860 and 1861. It provided seven-day mail service between St. Joseph, Missouri, and Sacramento, California.
In 1861 the Western Union Telegraph Company replaced the Pony Express and provided a faster, more reliable communication service. Furthermore, the transcontinental railroad was completed at Promontory, Utah, in 1869. These events improved the telegraph industry. The telephone was invented in 1876, and the first transcontinental telephone line was joined at Wendover, Utah, in 1915. This national telephone network provided a foundation for the wide area computer networks that evolved later in the twentieth century.
LANs consist of computers, scanners, printers, and cables, which are privately owned. WANs connect computers, scanners, printers, and other devices that sometimes may be leased or rented from public and private telephone companies or data communication companies. These networks place high demands on security and reliability.
In addition, the communication line or medium that a company uses for its network is either cable or a wireless technology. When a business creates a WAN, it might not manage all the lines. Sometimes a business leases lines from a communication company. These companies are data and voice carriers such as MCI, Sprint, Verizon, Williams Communications, and AT&T. In these cases, the WAN is not entirely owned by the initial business. The business owns the line up to the point where the handoff with the data carrier occurs. Then, the carrier company handles the transfer of data and hands it back to the business's private LAN network at a location many miles away.
The size of a LAN is set by the type of LAN configuration and specifications. For example, a LAN in a building might use an Ethernet technology such as 10Base2, also known as Thin Ethernet. This network technology can have one segment 656 feet (200 meters) in length or five linked segments up to 3,281 feet (1,000 meters) in length. A segment is the length of cable between two computers. For 10Base2, the 10 stands for 10 megabits per second, Base means baseband, and 2 equals 200 meters. Another technology is fiber distributed data interface (FDDI). FDDI networks can be up to 124 miles (200 kilometers) in length; these, however, are mostly used as backbone cables that link several LANs.
Because WANs cover large areas, they consist of network technology that extends farther distances than LANs. They incorporate technologies such as FDDI, DSL (digital subscriber line), satellite, and microwave communications. Also, they require routers, switches, and hubs that amplify and direct signals to other routers, switches, and hubs. They can increase their distances nationally and globally.
Another characteristic of a computer network is speed. Network speeds are measured in bits per second. For example, a byte consists of 8 bits, and one alphabetic character or numeric digit consists of 1 byte. If an average word length is five characters and an average double-spaced page is about 200 words, then a page (counting words and spaces) would consist of about 9,600 bits—((200 words×5 characters)+199 spaces)×8 bits. If a network speed is 9,600 bits per second (bps), then a normal double-spaced page is transmitted every second. If a network speed is 56,000 bits per second (56Kbps), about six pages of information per second would be transmitted.
LANs and WANs, however, are typically faster than 9,600 and 56,000 bps. Many networks are 10, 16, or 100 megabits per second (Mbps). A 100 Mbps network can send 100,000,000 bits in one second—or 10,416 pages per second. Some networks can transmit 2 billion to 8 billion bits per second (gigabits, or Gbps). At 2 Gbps (2,000,000,000/9600), 208,000 pages flash by every second—more than most people read in a lifetime. Network speeds are even reaching terabits per second. One Gbps equals a thousand gigabits—almost unthinkable!
The medium used to carry signals on a network can be conducted or radiated. Electric signals over wire are conducted. Fiber optic, microwave, infrared, and radio waves are examples of radiated media.
Wire can be shielded (STP) or unshielded (UTP) twisted pair or coaxial cable. UTP is cheaper to install than STP or coaxial cable; therefore, it is a popular network choice. STP or coaxial cable, however, should be used if there is electromagnetic interference on the network. Other networks overcome electromagnetic interference using fiber optic lines and wireless media. They are more expensive, however, than UTP wiring.
Twisted pair wires are rated by the American Wire Gauge (AWG) standard. Smaller numbers mean thicker wires. Regular telephone wire is rated a 28—too thin for most LANs. LANs use AWG ratings between 22 and 26. Another characteristic of twisted pair wires are the number of twists per foot. More twists may reduce cross talk and interference. Cross talk is when one line picks up noise or voices from another line during a conversation or data transmission. Usually 2 twists per foot are a minimum, while 4 are preferred.
Furthermore, the Electronic Industries Association (EIA) has another standard for rating wires. The EIA classifies LAN wires for different uses. For example, Category 3 (Cat 3) must contain 3 twists per foot and is commonly used in creating 10 Mbps LANs. Cat 5 is good for 100 Mbps and has sustained speeds up to 2 Gbps. Cat 7 reliably supports speeds up to 600 Mbps.
Baseband versus Broadband
Currently, most LANs use baseband transmission. Baseband means that there is one signal transmission per line. This means the channel or line is full when one device is sending data. It is easier for baseband LANs than for broadband LANs to have high speeds, behave reliably, and operate with low error rates. Also, baseband LANs are easily monitored by network administrators.
Broadband, on the other hand, means that the line can handle several transmission signals at one time. This is accomplished using different frequencies that act as separate channels. This is called frequency division multiplexing. Broadband networks have the capacity to handle more channels than baseband networks, but they are more expensive and intricate. A single cable that transmits many television channels is an example of broadband technology.
Because of the high interest in obtaining Internet services, broadband technology is becoming more affordable and widespread. For example, some cities are implementing a technology called broadband over power lines (PBL). PBL is a computer network providing Internet data service using broadband transmissions over public power lines. These networks operate at speeds of 90 Mbps.
Networks are diverse connections of components that are susceptible to interference, such as unauthorized breaches by attackers. Because of these vulnerabilities, network administrators have ongoing challenges keeping networks secure. Some of the vulnerabilities include eavesdropping, viruses, denial of service (DoS), spoofing, and e-mail bombs. These potential hazards can disrupt and curtail the goals of effective networks. Government networks, financial institutions, educational institutions, and specialty businesses are highly susceptible to attackers. Some of the methods to assure better security are established network firewalls, computer user policies, filter rules, incoming packet inspection mechanisms, and server isolation. While these can be successful, they are not foolproof. Network security planning and implementation is ongoing and constantly improving.
Wireless LANs are becoming more useful in homes, businesses, and schools. They are also known as Wi-Fi networks. Most of these networks use radio waves for their transmission medium, but some use infrared light waves. Radio waves travel free at the speed of 186,000 miles per second. Unlike light waves, radio waves can travel long distances and can penetrate through nonmetallic objects. Radio waves spread out over vast areas. Because of these advantages, wireless LAN and WAN networks are expanding rapidly.
A concern on wireless networks, interoperability results when vendors produce wireless components that do not work together. Efforts to prevent this from happening have been implemented. One example is the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standard. Most wireless vendors have agreed to follow this standard when producing wireless components. Also, the Wireless Ethernet Compatibility Alliance began certifying vendors who produce components that adhere to 802.11 provisions.
Security on Wi-Fi networks is also a major concern. Security protocols for wireless networks are provided in the 802.11i IEEE data communication standard. This standard defines security protocols that prevent the major security issues such as eavesdropping, spoofing, DoS, and others.
Networks have become an operational necessity for just about every business, government entity, school, and household. Burgeoning information demands make it necessary to link computers for efficient data sharing, storage, and communication. E-mail services are becoming a communication staple among computer owners. Additionally, enhanced services such as electronic commerce, graphics, and videoconferencing are causing networks to grow and expand. Properly managed networks increase productivity and assist managers and administrators with communication demands. Consequently, networks are an essential component of the information system plan of every business. Networks provide a crucial advantage for end users.
see also Information Systems ; Videoconferencing
Dennis J. LaBonty
In its simplest form, networking takes place between two devices that are directly connected. However, it is often impractical for devices to be directly connected, such as when devices are far apart or when more than two devices want to communicate. The solution is to attach each device to a communication network. Communication networks can be categorized on the basis of architecture and techniques to transfer data:
- broadcast networks, where a transmission from any device is broadcast and received by all other stations;
- circuit-switched networks, where a dedicated connection is established between devices on a network across switching nodes within the network;
- packet-switched networks, where data are sent in smaller units, called "packets," from node to node within a network from source to destination.
The basic configuration, or topology , of a network is the geometric representation of all the links and nodes of a network. A link is the physical communication path that transfers data from one device to another. A node is a network-addressable device. There are five basic topologies: mesh, star, tree, bus, and ring. In a mesh topology, every node has a dedicated point-to-point link to every other node, which requires n (n 1)/2 links to connect n nodes. For example, a network with 5 nodes would need 10 links to connect the nodes. In a star topology, each node has a dedicated point-to-point link to a central hub. If one node wants to send data to another, it sends to the hub, which then relays the data to the destination node. A tree topology occurs when multiple star topologies are connected together such that not every node is directly connected to a central hub. In a bus topology, one long cable connects all nodes in the network; in a ring topology, each node has a dedicated point-to-point connection to the nodes on either side in a physical ring such that a signal from a source travels around the ring to the destination and back to the source.
Network devices use signals in the form of electromagnetic energy to represent data. Electromagnetic energy, a combination of electrical and magnetic fields vibrating in relation to each other, includes electrical current, radio waves, and visible light. Unguided, or wireless, media transport electromagnetic waves without using a physical conductor to guide the wave. Instead, signals are broadcast through media, such as air or water, and are thus available to any device capable of receiving them. Guided, or wired, communications direct electromagnetic waves within the physical limitations of a conductor, which may be metallic wire, a hollow tube waveguide, or optical fiber.
Optical fiber uses light as a transmission medium. Light is electromagnetic energy at a specific range of frequencies (430 to 750 terahertz) whose speed depends on the density of the medium through which it is traveling. Theoretically, rays of light injected into strands of pure glass at specific angles will experience total internal reflection, meaning that no loss of energy occurs when light travels down the strand. In practice, some attenuation (loss of energy) and dispersion (mixing of frequencies) does occur because of impure glass and injected light signals at multiple frequencies; however, the range of frequencies, and thus data rates, that can be supported is dramatically higher than is possible with copper cables.
Copper cabling that accepts and transports signals in the form of electrical current comes in four different types:
- unshielded, which is used most commonly in telephone systems;
- twisted pair, which consists of two copper conductors surrounded by an insulating material and wrapped around each other to reduce significantly the impact of noise;
- shielded twisted pair, which has a metal foil encasing each twisted pair;
- coaxial cable, which carries signals of higher-frequency ranges because of its different construction (a central core conductor enclosed in an insulating sheath that is encased in an outer foil, or braid, that is protected by a plastic cover).
Types of Transmission
Asynchronous Transfer Mode (ATM) is a packet-switched technology where all the packets are the same size, referred to as "cells." Asynchronous means that the cells are independent of each other with potentially different gaps between them. The fixed cell size of 53 bytes allows ATM to have traffic characteristics such as increased switching speed and predictably decreased delay/cell loss, which is preferable for the convergence of real-time voice and video with data.
Other important networking techniques include Ethernet and frame relay. Ethernet is a standard for network devices communicating over a bus topology . Any device wishing to transmit will listen to the bus to determine whether the bus is clear; if the bus is clear, transmission can commence. If a collision between signals from different devices occurs, transmission stops and the process is repeated. Frame relay is a packet-switching protocol with no error correction that is appropriate for fiber optic links with their corresponding low error rates.
A local area network (LAN) is usually privately owned and connects nodes within a single office or building designed to share hardware, such as a printer; software, such as an application program; or data. A wide area network (WAN) provides long-distance transmission over large geographic areas that may constitute a nation, a continent, or even the whole world. A WAN that is wholly owned by a single company is referred to as an "enterprise network," but WANs may buy or lease network capacity from other companies. A metropolitan area network (MAN) is designed to extend over an entire campus or city. A MAN may be a single network, as with cable television, or a series of interconnected LANs.
Two other concepts that are relevant are the Internet and intranets. The Transmission Control Protocol/Internetworking Protocol (TCP/IP) is a set of protocols (or protocol suite) that defines how all transmissions are exchanged across the Internet. The Internet itself is a network of networks connected with the TCP/IP protocol suite connecting more than 200 million devices worldwide in virtually all populated countries. Conversely, an intranet is an organizational network of private addresses not directly accessible from the Internet.
see also Internet; Intranet; Telecommunications; World Wide Web.
Comer, Douglas E. The Internet Book: Everything You Need to Know about Computer Networking and How the Internet Works, 3rd ed. Englewood Cliffs, NJ: Prentice Hall, 2000.
Forouzan, Behrouz. Introduction to Data Communications and Network, 2nd ed. New York: McGraw-Hill, 2000.
Halsall, Fred. Data Communications, Computer Networks and Open Systems, 4th ed. New York: Addison-Wesley, 1996.
Stallings, William. Data and Computer Communications, 6th ed. New York: Macmillan, 2000.
A system of communication praised by many in the New Age movement as the best means of organizing people horizontally around common concerns (rather than veritically around leadership structures) and of data sharing. Networking of one kind or another has been practiced for many decades by means of directories, yearbooks, encyclopedias, specialized magazines, and groups, but with the development of modern computer resources, the facilities for accumulating, storing, and disseminating data on a wide scale have been greatly enhanced and accelerated. R. Buckminster Fuller observed,
"The new human networks emergence represents the natural evolutionary expansion into the just completed, thirty-years-inits-building, world-embracing, physical communications network. The new reorienting of human 'networking' constitutes the heart and mind pumped flow of life and intellect into the world arteries."
The concept of rapid access to topical information has special value in relation to New Age beliefs and practices, since so many groups and centers flourish for a while, then change name or address or disappear, sometimes giving rise to splinter movements. Many networking guides are presented in magazine format for distribution at occult and holistic health shops. Some have related publications in different countries through international networking. Many such publications have diaries of forthcoming events, exhibitions, and lectures. Other networking publications appear in a more traditional directory format, regularly updated.
Networking makes it possible to accumulate and disseminate New Age information in a variety of formats and at local, state, or city levels. Typical networking publications in magazine and/or tabloid newspaper format include Common Ground (San Francisco), PhenomeNews (Detroit), Whole Life (New York), and Whole Life Times (Los Angeles). Such publications tend to have a relatively short life, though these mentioned have lasted for more than a decade.
The Whole Life World Fair Expo, organized annually by the Whole Life Times, publishes a catalog that includes networking information on related events, individuals, and publications. The comparable British annual Festival for Mind-Body-Spirit has a special networking feature, inviting the public to "play the Networking Game," i.e., join a network to exchange information with other people, to keep track of meetings and contacts, and to benefit from the use of computers for exchange of information.
The Networking Game charges a small fee and provides guidance notes, a personal networking diary, a networking badge, personal address labels, and information on contacts in one's local area, as well as information on such facilities as Net Workshops, Playshops, a Networking Market for goods and services, and a computer conferencing network for "screen-to-screen" meetings. The Networking Game may be contacted c/o Sabine Kurjo, 21A Goldhurst Terrace, London, NW6 3HD, England.
Lipnack, Jessica, and Jeffrey Stamps. The Networking Book: People Connecting with People. New York: Methuen; London: Routledge & Kegan Paul, 1986.