bandwidth

The amount of data you can transmit over a period of time. E.g. a 56k modem can transmit (theortically) 56 * 1024 bits of information per second. A 1mb broadband connection can theoretically transmit 1000 * 1024 bits of information a second. Analagous to and often called pipe size.
 
Bandwidth is actually misused a lot of the time. An example might explain better..

If a signals lowest frequency is 2MHz and the highest 5Mhz the bandwidth is 3Mhz.

In common terminology it refers to how much data can be pushed across a medium (e.g. telephone lines). A high bandwidth means a high data rate such as broadband (DSL) which could be 512k bits / sec or better. A low bandwidth would be a dial up account 56k bits / sec. Strictly speaking this has not a lot to do with bandwidth but data rate.
 
Eddie - must have beat me to it. I like the analogy to pipes for a plumber!! I find plumbing a good way to understand electronics - Is this normal?
 
thanks for the replies

eddie that was how it was explained to me but i had been at the brown bottles at the time :oops:

porker when i went to college after chasing the dinosour from the end of the street one of the lecturers used to explain things thus

im a bit of gas where can i go and if i cant why ?

so i suppose its not really strange :D
 
Porker said:
Eddie - must have beat me to it. I like the analogy to pipes for a plumber!! I find plumbing a good way to understand electronics - Is this normal?

It is an actual technical term! For example with ADSL, you are connected to your exchange via the phone lines, your exchange is connected to your ISP via what is often referred to as a "fat pipe". Not to be confused with the tubing on liposuction equipment.

Of course, the term "broadband" is open to much debate and possibly rather subjective. Most would say that with respect to an internet connection, it is any connection faster than a single international standard digital phone channel (i.e. 64 kbps). Some ISPs have expressed that they feel it is misleading when other ISPs are selling 150kbps and 256 kbps services as "broadband", and Wannadoo in particular want 512kbps to be accepted as the minimum speed to class as "broadband" internet.

Porker is indeed correct on misuse of "bandwidth". It has gone the way of "baud rate", which is often (incorrectly) used when describing transfer speeds.

If I recall my old transmission lines lectures the available bandwidth of a single mode fibre is currently 1.6THz... not bad!
 
Broadband is/ or was defined as any baud rate over 1Mb/s so most people don't have broadband...... but I do!! :lol:
 
Eddie M said:
Broadband is/ or was defined as any baud rate over 1Mb/s so most people don't have broadband...... but I do!! :lol:

BAH! I thought about upgrading to a 1mbit or 2mbit adsl (not in central London so can't get anything faster than 2mbit out here). Then I realised I don't really use all my bandwidth anyway so decided not to (not just yet, anyway :D )

Well, baud rate... [geek] remember that both adsl and cable modem use modulation methods where the bitrate is several times greater than the baudrate. I am sure that you know this already, but a 2mbit connection will have a baudrate no greater than 256 or 512... [/geek]

I'm just jealous. :lol:
 
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