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2.4 Ghz Services - Channel to Frequency Chart...


Occupies part of the 13cm amateur radio band 2400-2450 Mhz with
aTV assigned to: 2406-2424 Mhz for aTV1 & 2430-2448 Mhz for aTV2

2.4 Ghz Services in Mhz - Video - Audio - Data and Telephone devices share this band.
As do microwave ovens (for cooking / heating water)

Typical distance of most communication gear is ~10 meters to 100 meters (300feet)
more if using specially designed narrowcast antenna (dish like objects on poles...)

Wireless
Audio
Services
Security
TV
Wireless
Video
Services
"Bluetooth"
Headsets
Cordless
Phones
IEEE
802.11b
=DSSS
802.11g
=OFDM
Wireless
Data
Services
Microwave
Ovens
Cooking
Food
Water
Audio
Services
Video
Services
18 Mhz
Bandwidth
2.402 -
2.480Ghz
2.4Ghz
Data.Ch.
5 Mhz
Bandwidth
50 Mhz
Bandwidth
Phones
Cordless
. . Audio
Channels
-- 2402 Mhz .
Intercoms . . Audio
Channels
-- 2407 .
wireless
headsets
. . Audio
Channels
01 2412 .
wireless
speakers
2.4Ghz
TV Ch.1
2413 Mhz Audio
Channels
-- ---- .
"Bluetooth" . . Audio
Channels
02 2417 Mhz .
InfraRed
extenders
. . Audio
Channels
03 2422 .
. . . Audio
Channels
04 2427 .
. 2.4Ghz
TV Ch.2
2432 Mhz Audio
Channels
05 2432 .
. . . Audio
Channels
06 2437 .
. . . Audio
Channels
07 2442 .
. . . Audio
Channels
08 2447 .
2450 Mhz
. 2.4Ghz
TV Ch.3
2452 Mhz Audio
Channels
09 2452 Mhz .
. . . Audio
Channels
10 2457 .
Data
Services
. . Audio
Channels
11 2462 .
Data
Loggers
. . Audio
Channels
12 2467 .
WiFi
Networks
2.4Ghz
TV Ch.4
2472 Mhz Audio
Channels
13 2472 .
. . . Audio
Channels
-- 2477 .
. . . Audio
Channels
-- 2482 .
. . . Data
Channel
14 2484 .
. . . Out of band
/ guard band
-- 2487 - 2497
Mhz
.



Terms:
DSSS = Direct Sequence Spread Spectrum
OFDM = Orthogonal Frequency Division Multplexing
"Bluetooth" also uses this frequency, hoping many 1000's times a second.

"Frequency Hoping" Allows more people to use this narrow part of the radio frequency spectrum by changing channels rapidly in predefined sequences. Thus allowing the "electronic smarts" to easily recover the audio / video / data information from what sounds like a hash of noise. Older video / audio systems show this noise as pulsating line interference or strong varying audio hiss.

2.4Ghz is considered a poor long distance (10's of km) terrestrial communication frequency due to the physics of water (vapor) absorption. As microwave ovens exploit this feature and operate at 1000's of watts inside a metal box to heat food. Because of this and an ever increasing list of devices using this band, Interference is very high. For short range with in 1 meter to 250 meters depending upon transmitted output power, interlinking devices is very good and with encoded signals turned on quite secure from other users of the frequencies / band. The other "public license" bands / frequencies that have similar uses for voice (phone) video (security) data (internet) are 900Mhz, 1.8Ghz, 5.8Ghz. Some of these bands are also used for mobile / cell phones, hence the ease of "bluetooth" or wireless functionality with your other communication / multi-media devices.
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