The 103 series uses the FSK modulation scheme, which through the use of a slow speed (300 bits per second
) is able to use closer-spaced frequency pairs.
* Compliance with the CCITT V.32 standard for full-duplex, 9600 bps (bits per second
) data transmission with Trellis encoding and echo cancellation
The most common method of communicating with a laptop computer is through a modem, a device that talks to other modems over ordinary telephone lines at speeds of 300, 1200 or 2400 bits per second
Alcatel-Lucent and BT have today announced trial speeds of up to 1.4Tb/s with a record spectral efficiency of 5.7 bits per second
per Hertz (b/s/Hz)on an existing core fiber connection.
Operating at a rate of 10 bits per second
, their computer-controlled, shoebox-sized, light-tight setup had polarized photons, generated by tiny diode lasers, traveling about 30 centimeters in air (SN: 6/20/90, p.
There remain many lower-speed (under 1 million bits per second
) local area networks supporting small numbers of PCs primarily for printer sharing and inter-PC file transfer, but these represent aging technology and are unlikely to support future networking needs.
Galileo's low-gain antennas could then step up data transmission from 10 bits per second
to 100 bits per second
24 in getting the craft to send 1,200 bits of information per second, not just the 40 bits per second
to which it dropped during its recovery from the first signal loss.
Magellan resumed communications with Earth last week only after it had entered a second safe mode, which sent information at 40 bits per second
instead of the usual 1,200.
The programs have already slowed data transmission rates to 600 bits per second
-- down from former rates of tens of thousands of bits per second
Earlier this year, the National Science Foundation (NSF) and the Defense Advanced Research Projects Agency awarded $15.8 million to the Corporation for National Research Initiatives, based in Reston, Va., to lead a research effort focusing on how to operate computer networks that transmit information at rates of a billion bits per second
Gans at AT&T Bell Laboratories in Holmdel, N.J., report theoretical calculations suggesting that a future superconducting coaxial cable made with a magnetically levitated core could transmitt data at a rate of 100 billion bits per second
over a distance of 600 kilometers, or about 375 miles.
To create a movie running at a rate of 30 pictures per second requires a flow of at least 240 million bits per second
Originally, the researchers had wanted to use a high-speed, satellite-based communications system, but they had to settle for a data network called NSFNET, which presently transmits information at 56,000 bits per second
. This transmission rate is too low for sending pictures, which typically require millions of bits of data each.
For example, a message for station A might be encoded in every fourth bit that passes by in a stream that could consist of several billion bits per second
. The connection for station A would then take out every fourth bit and send it to the receiver.