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Prestige 2802HW(L)-Ix Support Notes
All contents copyright (c) 2007 ZyXEL Communications Corporation.
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What is 802.11b ?
802.11b is the first revision of 802.11 standard allowing data rates up to 11Mbps in the 2.4GHz ISM band.
Also known as 802.11 High-Rate and Wi-Fi. 802.11b only uses DSSS, the maximum speed of 11Mbps
has fallbacks to 5.5, 2 and 1Mbps.
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 utilise the
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.
Is it possible to use products from a variety of vendors ?
Yes. As long as the products comply to the same IEEE 802.11 standard. The Wi-Fi logo is used to define
802.11b compatible products. Wi-Fi5 is a compatibility standard for 802.11a products running in the
5GHz band.