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NetCHEIF Articles

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, ,

( Channel Bonding, MIMO
-Spatial Stream N)

N ( 802.11N) 300Mbps 600Mbps.  , (MIMO), (Spatial Stream), -Guard Time, (Channel Bonding) '.

, N .  " " (Channel Bonding) -" " (Spatial Stream), .

 

, , .  , "".  , (frequency) , (modulation) (channel)

:

:  - .  (Hz).  2.4Ghz 2.4 .

:  -.  , .  - -LINK- .

:  .

 

-- 802.11B (" B") -- 1999

B -11Mbps ( -6Mbps).  , , -72Mhz 2.4Ghz.

, B -11 (""), 22Mhz, 5Mhz.

B -DSSS ( Direct-sequence Spread Spectrum).

12 -13, , 14 .  12 -13 5Mhz, 14 12Mhz 13.  B -84Mhz ".

, , -5Mhz , .

13 , 3 - 1, 6 -11.

B, , / (5.5Mhz, 2Mhz -1Mhz) .  , .

 

802.11G (" G") -- 2003

B , .  G, 2003 B, OFDM ( Orthogonal frequency-division multiplexing). 

-OFDM 5 -54Mbps ( -23Mbps), G B -- 2.4Mhz

B - -G B. 

, G B, .  -48, 36, 24, 18, 12, 9, 6, 2 -1Mhz G "" 12 -- 10 G 2 B - 11Mbps -5.5Mbps ( 1 -2Mbps ).

2.4Mhz, G , Bluetooth, 2.4Mhz .  .

, G , , (repeater), (, , ) .  .

 

802.11N (" N") -- 2009

G, 2003 .  , , B G.

(coverage), , , N (range) .  , N, G .  -- , N, G, , G.

N / "" -- .  N , , G.

, N, 2009 .  6 , (Pre N -Draft 2) .

N , , :

  • G (-OFDM) -54Mbps -58.5Mbps.

  • -58.5Mbps -65Mbps.

  • (GI - Guard Interval) -800ns -400ns, -65Mbps -72.2Mbps.

  • (Channel Bonding) / -20Mhz -40Mhz -72.2Mbps -150Mbps.

  • (MIMO) -" " (Spatial Stream), , -150Mbps -300Mbps.  , -4 , 600Mbps.

300Mbps 600Mbps.  , 150Mbps N.  N -MIMO 150Mbps 150Mbps 1X1 ( ).

/ 95Mbps.

, -54Mbps -300Mpbs -- (MIMO) -" " (Spatial Stream) (Channel Bonding). 

 

(MIMO) (Spatial Stream)

(MIMO - Multiple In, Multiple Out) (Spatial Stream) N.

MIMO , RF .  , , .

-RF (, ), .  N ( ) RF - ( 4 ).

(specifications) TxR, T -R 1 -4.  , T -RF (transmit) -R -RF (receive).  2X2, RF RF .

( ) -RF ( ).  -RF , ( ).  , RF, 2X2.

, .  , .  . 

, , -11 ( , ).

B G, , .  N, - , . 

N " " (Spatial Stream) , 3X3 2X2 .

, .  .

MIMO -" " N, (Channel Bonding) .

(Channel Bonding), B, G -N -- .

 

B -G, N -13 , -20Mhz.  , 13 , - 1, 6 -11.  , .

.  -14 -25 .

, .  , , . 

, .

N G - N .

 

(Channel Bonding)

2.4Ghz, N .  .  " " (Channel Bonding).

, N, , -90Mbps.  -70Mbps.

5 (, 6 4, 5, 7 -8), , 9 .

, 6 , 10 .  6 -10 ( 8 ), 4, 5, 7, 8, 9, 11 12.

-Channel Bonding.  1, 6 11 .

, N 9 .  , .

N .  -Auto 20/40Mhz.

, .  , , .

, , Auto 20/40Mhz, 20Mhz ( ).

, , .  iperf .