In general, broadband refers to telecommunication in which a wide band of frequencies is available to transmit information. Because a wide band of frequencies is available, information can be multiplexed and sent on many different frequencies or channels within the band concurrently, allowing more information to be transmitted in a given amount of time (much as more lanes on a highway allow more cars to travel on it at the same time). Related terms are wideband (a synonym), baseband (a one-channel band), and narrowband (sometimes meaning just wide enough to carry voice, or simply “not broadband,” and sometimes meaning specifically between 50 cps and 64 Kpbs).
Various definers of broadband have assigned a minimum data rate to the term. Here are a few:
Newton’s Telecom Dictionary: “…greater than a voice grade line of 3 KHz…some say [it should be at least] 20 KHz.”
Jupiter Communications: at least 256 Kbps.
IBM Dictionary of Computing: A broadband channel is “6 MHz wide.”
It is generally agreed that Digital Subscriber Line (DSL) and cable TV are broadband services in the downstream direction.
WHAT IS BANDWITH
1) In electronic communication, bandwidth is the width of the range (or band) of frequencies that an electronic signal uses on a given transmission medium. In this usage, bandwidth is expressed in terms of the difference between the highest-frequency signal component and the lowest-frequency signal component. Since the frequency of a signal is measured in hertz (the number of cycles of change per second), a given bandwidth is the difference in hertz between the highest frequency the signal uses and the lowest frequency it uses. A typical voice signal has a bandwidth of approximately three kilohertz (3 kHz); an analog television (TV) broadcast video signal has a bandwidth of six megahertz (6 MHz) — some 2,000 times as wide as the voice signal.
3G(Third Generation Mobile Telephony)
3G is an ITU(International Telecommunication Union) specification for the third generation (analog cellular was the first generation, digital PCS the second) of mobile communications technology.3G promises increased bandwidth up to 384 Kbps when a device is stationary or moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps in fixed applications. Implemented in Europe as UMTS and CDMA2000 in North America, its goals are high-quality multimedia and advanced global roaming.
WCDMA(Wideband Code Division Multiple Access)
A 3G technology that increases data transmission rates in GSM systems by using the CDMA air interface instead of TDMA. WCDMA is based on CDMA and is the technology used in UMTS. WCDMA was adopted as a standard by the ITU under the name “IMT-2000 direct spread”. It has been selected for the third generation of mobile telephone systems in Europe, Japan and the United States.
UMTS(Universal Mobile Telecommunications System)
Third generation telecommunications system based on WCDMA-DS. The goal of UMTS is to enable networks that offer true global roaming and can support a wide range of voice, data and multimedia services. A new-generation technology for rapidly moving data and multimedia over wireless devices. The European implementation of the 3G wireless phone system, UMTS provides service in the 2GHz band and offers global roaming and personalized features; designed as an evolutionary system for GSM network operators, multimedia data rates offered by UMTS are: vehicular – 144 kbit/s; pedestrian 384 kbit/s; in-building 2Mb/s.
HSDPA(High-Speed DownlinkPacket Access)
HSDPA is a packet-based data service in WCDMA downlink with data transmission up to 8-10 Mbps (and 20 Mbps for MIMO systems) over a 5MHz bandwidth in WCDMA downlink. The high speeds of HSDPA are achieved through techniques including: 16 Quadrature Amplitude Modulation, variable error coding, and incremental redundancy.
ATM(Asynchronous Transfer Mode)
A network technology protocol based on encoding and transmitting data in relatively small cells/packets of a fixed length. Allows for high-speed transmission of video, audio and data over the same network.
ATM is a connection-oriented switching technique with very high speed and high bandwidth. The CCITT (Consultative Committee International Telephone and Telegraph) is betting on ATM’s many benefits for the future broadband network.
Surprise: America is No. 1 in Broadband
There is a constant refrain that the United States is falling behind in broadband, as if the speed of Internet service in Seoul represents a new Sputnik that is a challenge to national security.
It’s certainly true that in some countries, like South Korea, far more homes have broadband connections than in the United States. And the speeds in some countries are far higher than is typical here.
But there are many ways to measure the bandwidth wealth of nations. At the Columbia/Georgetown seminar on thebroadband stimulus yesterday, I heard Leonard Waverman, the dean of the Haskayne School of Business at the University of Calgary, describe a measure he developed called the “Connectivity Scorecard.” It’s meant to compare countries on the extent that consumers, businesses and government put communication technology to economically productive use.
Even after deducting the untold unproductive hours spent on Facebook and YouTube, the United States comes out on top in Mr. Waverman’s ranking of 25 developed countries. The biggest reason is that business in the United States has made extensive use of computers and the Internet and it has a technically skilled workforce.
“Korea has great broadband to the house, but businesses in Korea don’t use the best networks and don’t have the skills and computing assets they need to take advantage of them,” Mr. Waverman said.
Also, as dusty as your local motor vehicle office may seem, government use of communications technology is as good in the United States as anywhere in the world, according to Mr. Waverman’s rankings.
After the United States, the ranking found that Sweden, Denmark, the Netherlands, and Norway rounded out the five most productive users of connectivity. Japan ranked 10, and Korea, 18.
And while wired and wireless broadband networks used by consumers lagged other countries, the United States ranked No. 1 in the world for technology use and skills by consumers. (This was measured by comparing countries on five measures: The penetration of Internet use, penetration of Internet banking, wired and wireless voice minutes per capita, SMS messages per capita, and consumer software spending.)
A separate paper based on the survey research of the Pew Internet and American Life project also undercut the idea that Americans are starving for broadband.
First of all, Pew found that 57 percent of people in the country now have access to broadband, compared to only 9 percent who have dial-up Internet access. Another 9 percent of people use the Internet at work or at a library but not at home.
That leaves 25 percent of the population that doesn’t use the Internet at all. When Pew looked at the reasons why people didn’t use broadband (combining dial-up users with those that don’t have Internet access at all), it found that by far the most common reason was that people said that going online was not relevant to their lives. Some 51 percent of people surveyed in these groups said things like they weren’t interested in the Internet or they were too busy.
The second-most common reason was money: 18 percent of the people said that the cost of broadband was too high or that they don’t have a computer. Next came usability, with 17 percent citing reasons like the Internet was too difficult to use or wasted too much time.
Rather significantly, for the debate about broadband in rural areas, only 14 percent of the people who don’t havebroadband now say the reason is that they can’t get it. That represents 4.5 percent of the population. Those figures match up with statistics from the cable industry, which says it now offers broadband service to 95 percent of the homes in America.
Cycle all this back to the findings by Mr. Waverman. Since his research found that, on average, Americans have more technology skills and involvement than people in any other country, maybe the biggest reason that 39 percent of the population doesn’t have broadband is that they know what they’d get — and they don’t want it.