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P-870HN-5xb Support Notes
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 less
(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 the second revision of 802.11 that operates in the unlicensed 5 GHz band
and allows transmission rates of up to 54Mbps. 802.11a uses OFDM (orthogonal
frequency division multiplexing) 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
to an 802.11a access point. Multi-mode NICs will solve this problem.
What is 802.11g?
802.11g is an extension to 802.11b. 802.11g increases 802.11b's data rates to 54
Mbps and still utilize the 2.4 GHz ISM. Modulation is based upon OFDM (orthogonal
frequency division multiplexing) technology. An 802.11b radio card will interface
directly with an 802.11g access point (and vice versa) at 11 Mbps or lower depending
on range. The range at 54 Mbps is less than for 802.11b operating at 11 Mbps.
What is 802.11n?
802.11n is a recent amendment which improves upon the previous 802.11 standards
by adding
multiple-input multiple-output
(MIMO) and many other newer features.
The IEEE has approved the amendment with an expected publication in mid October
2009.
All contents copyright (c) 2009 ZyXEL Communications Corporation.
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