What is Bandwidth?

In Internet terms, Bandwidth is a measure of potential throughput (speed) in "bits per second" (bps), of the amount of data that can be sent over a particular cable or interface.

The higher a network's bandwidth, the faster a volume of data that can be transmitted.

How do I compare bandwidth?

You may already be familiar with the following expressions of bandwidth:

• 56 kbps - the bandwidth of your dial-up modem
  
• 256 kbps - the bandwidth of your ADSL home broadband
  
• 1.5 Mbps (1,500 kbps) - the bandwidth of business ADSL
  
• 100 Mbps - the bandwidth of your LAN.
• 2 Gbps (2,000 Mbps) - Seriously High-Bandwidth from OFW

100 Mbps Ethernet is now the minimum bandwidth recommended for local area network traffic. Many new networks are being installed with Gigabit Ethernet (1,000 Mbps Ethernet)

What is High-Bandwidth broadband?

The goal posts keep moving with this one. Until very recently a
2 Mbps E1 would have been considered a very fast Internet connection. Today however, with the advent of many new online services this is no longer the case. 10 Mbps is now the minimum bandwidth required to keep up with innovations.

Many organisations connect their office WANs at 100 Mbps creating seamless connectivity between their offices.

Optic Fibre & Wireless (OFW) can connect your organisation together at speeds up to 2 Gbps (2,000 Mbps) or 20 x faster than your LAN!

How much bandwidth do you need?

Nielsen's Law of Internet bandwidth states that Internet connection speeds will grow 50% every 12 months.

Faster computing always leads to greater productivity. How much bandwidth you need today may be insignificant to your needs in the future. Choosing a broadband platform that is scalable and can grow with your needs will provide greatest flexibility for your organisation. OFW can provide advice on your bandwidth needs.

bits, kilobits, megabits.... What do they all mean?

To understand bandwidth and the speed it provides as comfortably as we understand "kilometres per hour" we first need to understand the units of measure; bit, kilobit, megabit and gigabit. Handy tip: Bit is to kilobit as metre would be to kilometre.

bit
This is the smallest unit of measure in a computer. It is represented by a 0 (off) or 1 (on). It can be thought of a bit as a switch. If it is in the on position, it is a 1, and if the switch is off, it is a 0. All computer communication is in bits.

byte
A set of bits that represent a single character. Usually there are 8 bits in a byte.

kilobit
(kbit) - There are usually 1,024 bits in one kilobit. (kilo = thousand) To calculate the average number of bytes in a kilobit, divide the number of bits - 1,024 by 8 = 128 bytes. Knowing this will be helpful later.

kilobyte
(kB) - One kilobyte is 1,024 bytes or 8 kbit. Microsoft Internet Explorer uses kB as the unit of measure when downloading a file from the Internet.

megabit
(Mbit) - This is roughly one million bits. 1,048,576 bits (mega = million). 1 Mbit also equals 1,024 kbits.

megabyte
(MB) - One megabyte is 1,024 kilobytes or 8 Mbits. (Your trusty 3.5 inch floppy diskette holds 1.44 MB).

gigabit
(Gbit) This refers to approximately 1 billion bits. More exactly, it is 2^30 or 1,073,741,824 bits. (giga = billion) 1 Gbit also equals 1,024 Mbits.

In summary, one Gbit = 1,024 Mbits and one Mbit = 1,024 kbits.

Now that we understand our units of volume we can describe the rate at which we transfer it from one location to the other. This rate is measured "per second"

bps
(bits per second) This is a measure of how fast some devices communicate, usually in thousands of bits per second (kbps) or millions of bits per second (Mbps).

kbps
(kilobits per second) A measurement of the transmission speed of data measured in 1,024 bits per second.

kB/Sec
(kilobytes per second) This is the figure you observe when you are downloading a file using Microsoft Internet Explorer. Your "speedometer" if you like. Below we teach you how to convert your bandwidth (kbps) into kB/Sec.

Mbps
(megabits per second) This is a measure of throughput in megabits per second or one million bits per second.

Gbps (gigabits per second) This is a measure of throughput in gigabits per second 1 billion bits per second. (1,000 Mbps)

Dial-up and DSL bandwidth is measured kbps. Speed is usually measured in kB/Sec (on most Microsoft interfaces):

How do I convert my bandwidth into "download speed"?

To convert your bandwidth into "download speed", divide the number of kbps (of your connection) by 8 to convert to kB/Sec,

Here are some examples:

Dial-up 56 kbps: divide 56 / 8 = download speed of 7 kB/Sec
ADSL 256 kbps: divide 256 / 8 = download speed of 32 kB/Sec
ADSL 512 kbps: divide 512 / 8 = download speed of 64 kB/Sec
ADSL 1,500 kbps: divide 1500 / 8 = download speed of 187.5 kB/Sec

NB. It is important to consider that these calculations do not take into account any network overhead. Allow a 10 - 20 % reduction in speeds for real world speeds. For example, the maximum download speed for a 56 kbps would rarely be more than 5 kB/Sec. ADSL 256 is up to 5 x faster (25 kB/Sec) than 56 kbps. Also, the Internet does not guarantee speeds for data tranfer. At peak times data traffic will be slower, just like motorcar traffic on a highway.

Data transfer rates for OFW broadband solutions and LANs are measured in Mbps and Gbps:

10 Mbps (10,000 kbps): 10,000 / 8 = 1,250 kB/Sec
(nearly one floppy diskette every second)

100 Mbps: 100,000 / 8 = 12,500 kB/Sec or 12.5 MB/Sec
(Over 8 floppy diskettes every second)

1 Gbps: 1,000,000,000 / 8 = 125,000,000 kB/Sec or
125,000 MB/Sec (Over 86,000 floppy diskettes every second)

OFW can provide solutions up to 2 Gbps (2,000 Mbps).

Copper technologies may ease some short-term pain, but the bandwidth limitations of 2 megabits to 4 megabits makes them a marginal solution, even on a good day.

OFW can provide your organisation with a flexible and scalable broadband solution with speeds from 1 Mbps to 2 Gbps:

• Optic Fibre (Fibre Broadband)
• Free Space Optics (FSO Broadband)
• Microwave (Wireless Broadband via Wi-Fi and WiMax)
• DSL (Digital Subscriber Line)
• E1 (Leased Line)

Are you located nearby to high-bandwidth resources? Check here