8 | Wireless RF Introduction
Wireless RF Introduction
There are currently four widely adopted standards for 802.11
wireless network types: a, b, g, and n. Although 802.11n is the
newest and highest capacity standard, each of the four
standards has its own strengths and weaknesses. This section
provides overviews of these standards.
See the following sections for a brief overview of Radio
Frequency technologies:
• 802.11 Comparison Chart - page 8
• Radio Frequency Barriers - page 8
• RF Interference - page 8
802.11 Comparison Chart
The following table compares signal characteristics as they
apply to the current 802.11standards:
Radio Frequency Barriers
The following tables list some common RF barrier types:
RF Interference
The following table lists several common interference sources:
802.11a 802.11b 802.11g 802.11n
# of Channels in USA 23 11 11 11
# of Channels in EU 23 13 13 13
# of Channels in Japan 15 14 14 14
Frequency Band 5GHz 2.4GHz 2.4GHz 2.4/5GHz
Max. Data Rate 54Mbps 1 1Mbps 54Mbps 150Mbps
300Mbps
Radius (Range) 90ft/25m 120ft/
35m
120ft/
35m
300ft/90m
Barrier Type RF Signal
Blocking
Open air Very Low
Glass, drywall, cubicle partitions Low
Stone floors and walls (brick/marble/granite) Medium
Concrete, security glass, stacked books/paper High
Metal, metal mesh, reinforced concrete, water Very High
Interference Source Possible RF Interference Band(s)
Affected
2.4GHz phones Entire range (hundreds of
feet)
802.11b/g/n
Bluetooth devices Within 30 feet 802.11b/g/n
Microwave oven
a
a.Most newer model microwave ovens have sufficient shielding
to negate possible RF interference.
Within 10-20 feet 802.11b/g/n
Scientific and medical
equipment
Short distance, varies 802.1 1b/g/n
Other wireless devices Entire range All
RF reflective objects Long-range wireless bridging All