What Is 802.11B; How Fast Is 802.11B; What Is 802.11A - ZyXEL Communications SBG3300 series User Manual

The IEEE 802.11 is a wireless LAN industry standard, and the objective of IEEE 802.11
is to make sure that different manufacturers' wireless LAN devices can communicate
with each other. 802.11 provides 1 or 2 Mbps transmission data rates in the 2.4 GHz
ISM band using either FHSS or DSSS modulation.

What is 802.11b?

802.11b is the first revision of 802.11 standard allowing data rates up to 11 Mbps in
the 2.4GHz ISM band. It is also known as 802.11 High-Rate and Wi-Fi. 802.11b only
uses DSSS modulation, and the maximum speed of 11 Mbps has fallbacks to 5.5, 2
and 1 Mbps.

How fast is 802.11b?

The IEEE 802.11b standard has a nominal speed of 11 megabits per second (Mbps).
However, depending on signal quality and how many other people are using the
wireless Ethernet through a particular Access Point, usable speed will be much lower
(on the order of 4 or 5 Mbps, which is still substantially faster than most dialup, cable
and DSL modems).

What is 802.11a?

802.11a is the second revision of 802.11 that operates in the unlicensed 5 GHz band
and allows transmission rates of up to 54 Mbps. 802.11a uses OFDM (orthogonal
frequency division multiplexing) modulation as opposed to FHSS or DSSS. Higher data
rates are possible by combining channels. Due to higher frequency, range is less than
lower frequency systems (i.e., 802.11b and 802.11g) and can increase the cost of the
overall solution because a greater number of access points may be required. 802.11a
is not directly compatible with 802.11b or 802.11g networks. In other words, a user
equipped with an 802.11b or 802.11g radio card will not be able to interface directly
with an 802.11a access point. Multi-mode NICs can solve this problem.