Megabits per second (Mbps) refers to data transfer speeds as measured in megabits (Mb). This term is commonly used in communications and data technology to demonstrate the speed at which a transfer takes place. A megabit is just over one million bits, so "Mbps" indicates the transfer of one million bits of data each second. Data can be moved even faster than this, measured by terms like gigabits per second (Gbps).
Understanding the Megabit
A bit is a single unit of data, expressed as either a "0" or a "1" in binary code. A string of eight bits equals one byte. Any character formed, such as a letter of the alphabet, a number, or a punctuation mark, requires eight binary bits to describe it. For example:
- A = 01000001
- B = 01000010
- a = 01100001
- b = 01100010
- 6 = 00110110
- 7 = 00110111
- ! = 00100001
- @ = 01000000
A megabit actually has two different values, depending on the context of the term. When used to describe data storage, a megabit (Mb) is the equivalent of 220 or 1,048,576 bits. However, when used to describe data transfer rates, one Mb equals 1,000,000 bits. Therefore, 1 Mbps is equal to 1,000,000 bits per second, not 1,048,576.
Distinction Between Megabits and Megabytes
In addition to the confusion over the value of a megabit, some people can also confuse the megabit (Mb) and the megabyte (MB). As noted earlier, one byte (B) is comprised of 8 bits (b). The distinction between megabytes in data storage and transfer contexts is the same as megabits and can lead to additional confusion. However, 1 megabyte per second (MBps) is equal to 8 Mbps (megabits per second). It is important to notice that the capital "B" is what distinguishes between megabits per second (Mbps) and megabytes per second (MBps).
Usage in Networks
Networking technologies are commonly rated in terms of megabits per second. This includes phone-line networks, wireless communications, and commercial or public networks like the Internet. Companies that sell high-speed service often advertise data transfer speeds in terms of Mbps, though some also use 1,000 bits or kilobits per second (kbps). Wireless routers and network interface cards (NICs) are among the hardware devices generally evaluated and advertised in terms of data transfer rates.
When purchasing equipment, customers should compare speeds properly between components to ensure they get the best possible rates. It is important to buy components that support equal speeds, as the slowest component will often determine the speed of the connection. For example, if a wireless router supports speeds up to 54 Mbps, upgrading to an NIC that supports up to 108 Mbps will make little difference without upgrading the router as well. The higher speed of the card may get data more quickly from the router to the computer, but the router itself can only transfer data at half that speed.
As communications technology continues to advance, the speed of data transfers also increases. In much the same way that memory has moved from megabytes to gigabytes, data rates are also changing from megabits to gigabits. A gigabit is one billion bits or 1,000 megabits.