Data communication – of the IEEE 802 type

There is a lot of confusion and misinformation related to data communication.

An interesting snippet related is that data storage occurs in multiples of 1024 per Kilobit or Kilobyte. Data transmission occurs at 1000 per Kilobit or Kilobyte.

Wired communication is typically IEEE 802.3 in a range of speeds 10, 100, 1000 and 10000 Megabits per second. Abbreviated Mb/s. This is often referred to as Ethernet. 10/100 Ethernet, Gigabit Ethernet, and 10 Gigabit Ethernet. Note that 100Mb/s and 100MB/s are different values. Mb is Megabit. MB is Megabyte. A bit is 1/8th of a Byte. A Byte is 8 bits.

Wireless communication is typically IEEE 802.11. 802.11 comes in a few different values also. 802.11a is pretty well obsolete and useless. 802.11b is also pretty useless. 802.11g has a maximum throughput of 54Mb/s and 802.11n has a maximum throughput of 300Mb/s.

MoDems ( an acronymn for Modulate/Demodulate ) communicate at kilobaud rates, not kilobits or kilobytes. Modems are analog devices that connect a computer or other digital device to an analog medium. A baud is the amount of data to create one symbol, but not a bit or a byte.

Any device that connects your computer to a Digital Subscriber Line (DSL) or Cable is not actually a MoDem at all. It is a network bridge. It passes the digital signal of your computer from Ethernet to DSL or Ethernet to RG-58 or even Ethernet to Fibre in some cases. It does not MOdulate or DEModulate the signal. It may multiplex the signal but that’s a story for another day.

Something that often gets overlooked in data communication speed is overhead. No matter what brand or type of hardware, no matter how great the cable or the wireless devices, networks ALWAYS have overhead, some types of networks are more efficient than others. Network layer overhead is the amount of the network capacity that is required to establish and maintain the basics of communication. Typical network layer overhead for IEEE 802.x is twenty percent. The overhead of each PACKET of data sent via Ethernet is 8 percent. There are 2 types of network overhead. A) Protocol Overhead and B) Network Layer Overhead.

A classic example of this in actual use is FTP vs. HTTP for file transfers. FTP is always faster than using HTTP if you are using the same network. FTP does not send a confirmation frame at the end of transmission. HTTP does.

Another commonly maligned term is Bandwidth. Bandwidth is NOT the amount of speed you have available. Bandwidth is the difference between the lowest and highest frequency of the carrier signal. It is a determining factor for the RATE of data flow but not actually the rate of data flow. Think of this as the diameter of the water pipe. The water pipe diameter can determine the maximum flow of water at a given pressure, but it does not determine what the current flow is. It is merely the top end theoretical limiting factor. Bandwidth is measured in hertz. Abbreviated Hz.

Now let’s look at a term called “Goodput”. Goodput is the theoretical maximum taking protocol and network overhead into account. It DOES NOT factor in retransmissions for dropped packets, confirmation packets for TCP, or interframe gap overhead. Goodput on a 100Mb/s Ethernet cable is 12MB/s. You will never actually get that rate of speed from a 100Mb Ethernet connection. Goodput for a Gigabit Ethernet is 120MB/s. Again still a theoretical value. Actual burst rates are usually in the range of 100MB/s for a Gigabit Ethernet connection. Sustained rates often drop to 75MB/s or lower.

These overhead factors effect wired and wireless communication in the same ways.

A 300Mb/s IEEE802.11n connection has a theoretical Goodput rate of 36MB/s. Which is indeed faster than 100Mb/s Ethernet’s Goodput rate of 12MB/s.

So yes, 802.11n can be and typically is faster than 100Mb/s Ethernet. Not as fast as Gigabit Ethernet though.

There are three other major factors to take into consideration when deciding between an 802.3 Network and an 802.11 Network.

1) Security – Hands down 802.3 Wins this point. Even when you employ every security measure possible, 802.11 is not very secure.

2) Price – 802.11 Typically wins this battle by a huge margin. CAT6 cable is not cheap.

3) Mobility – 802.11 ALWAYS wins this point.

We have but one Internet, and yes is has wires in many places. Yes, Internet is a proper noun even.
There is no such thing as Wireless Internet.
I always chuckle when I hear someone in an IT capacity say Wireless Internet, it defines their lack of expertise.