ZyXEL Communications 1123-AC User Manual

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Appendix E Wireless LANs
NWA1000 Series User’s Guide
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Use short preamble if you are sure all wireless devices on the network support it, and to provide 
more efficient communications.
Use the dynamic setting to automatically use short preamble when all wireless devices on the 
network support it, otherwise the NWA uses long preamble.
Note: The wireless devices MUST use the same preamble mode in order to communicate.
Wireless LAN Standards
The IEEE 802.11b wireless access standard was first published in 1999. IEEE 802.11b has a 
maximum data rate of 11 Mbps and uses the 2.4 GHz band.
IEEE 802.11g also works in the 2.4 GHz band and is fully compatible with the IEEE 802.11b 
standard. This means an IEEE 802.11b adapter can interface directly with an IEEE 802.11g access 
point (and vice versa) at 11 Mbps or lower depending on range. IEEE 802.11g has several 
intermediate rate steps between the maximum and minimum data rates (54 Mbps and 1 Mbps 
respectively).
IEEE 802.11a has a data rate of up to 54 Mbps using the 5 GHz band. IEEE 802.11a is not 
interoperable with IEEE 802.11b or IEEE 802.11g.
IEEE 802.11n can operate both in the 2.4 GHz and 5 GHz bands and is backward compatible with 
the IEEE 802.11a, IEEE 802.11b, and IEEE 802.11g standards. It improves network throughput and 
increases the maximum raw data rate from 54 Mbps to 300 Mbps by using multiple-input multiple-
output (MIMO), a channel width of 40 MHz, frame aggregation and short guard interval.
Wireless Security Overview
Wireless security is vital to your network to protect wireless communication between wireless 
clients, access points and the wired network.
Wireless security methods available on the NWA are data encryption, wireless client authentication, 
restricting access by device MAC address and hiding the NWA identity.
Table 55   
Wireless LAN Standards Comparison Table
WIRELESS LAN 
STANDARD
MAXIMUM NET 
DATA RATE
FREQUENCY 
BAND
COMPATIBILITY
IEEE 802.11b
11 Mbps
2.4 GHz
IEEE 802.11g
IEEE 802.11n
IEEE 802.11g
54 Mbps
2.4 GHz
IEEE 802.11b
IEEE 802.11n
IEEE 802.11a
54 Mbps
5 GHz
IEEE 802.11n
IEEE 802.11n
300 Mbps
2.4 GHz, 5 GHz
IEEE 802.11b
IEEE 802.11g
IEEE 802.11a