IEEE 802.11n is wireless Network standard that In compare with prior standards have very higher speed from 54 Mbit/s to ...
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
Wireless N 802.11N Assumption University of Thailand ICT 6201- Mobile and Wireless Network (3/2011) Term paper Ali Ghalehban Zanajab
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Introduction IEEE 802.11n is wireless Network standard that In compare with prior standards have very higher speed from 54 Mbit/s to 600 Mbit/s
this standard standard improve
network throughput over the two previous standards 802.11a and 802.11g .802.11n standardized support for multiple-input multiple-output and frame aggregation, and security improvements, among other features. With speeds of up to 600 Mbps, the emerging 802.11n standard is the next generation of wireless networking, delivering the speed, range, and reliability reliability to support the most most bandwidth intensive applications. 802.11n incorporates
multiple technologies including Spatial
Multiplexing MIMO (Multi-In, Multi- Out), 20 and 40 MHz channels, and dual bands (2.4 GHz and 5 GHz) to generate the high speeds speeds and at the same time communicate with 802.11b/g 802.11b/g
devices. 802.11n specification was approved approved in in
September 2009. Manufactureres
are committed to collaborating with the IEEE
and WiFi Alliance to ensure ensure that 802.11n 802.11n devices will interoperate interoperate at the highest speeds
without degrading performance of neighboring 802.11b/g wireless
networks.
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Assumption University Of Thailand – Ali Ghalehban
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
802.11 N vs 802.11a/b/g Here in blowe we will have a brief compartion between other wireless standards and Wireless N standard standard . if you check 2 last column you you can see that Wireless Wireless N Outdoor & indoor range (70 m – 250 m ) is higher than other Standards .
802.11 network standards Table
802.11
Freq.
protocol
(GHz)
Bandwi dth (MHz)
Data rate per stream
Modulatio
(Mbit/s)
n
— Legacy
2.4
20
1, 2
mode
DSSS,FH SS
5 a
20
6, 9, 12, 18, 24, 36, 48, 54
2.4
20
g
2.4
20
20 n
1, 2, 5.5, 11
DSSS
6, 9, 12, 18, 24, 36, 48,
OFDM,DS
54
SS
7.2, 14.4, 21.7, 28.9, 43.3, 57.8, 65, 72.2
2.4/5
indoor range
range
(m)
(ft)
(m)
(ft)
20
66
100
330
35
115
120
390
—
—
5,000
16,000
35
115
140
460
38
125
140
460
70
230
250
820
70
230
250
820
OFDM 40
2
Approximate outdoor
OFDM
3.7
b
Approximate
15, 30, 45, 60, 90, 120, 135, 150
Assumption University Of Thailand – Ali Ghalehban
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
802.11 N More Antenna = Higher Speed 802.11 N uses multiple technologies including Spatial Multiplexing MIMO (MultiIn, Multi-Out), 20 and 40 MHz channels, and dual bands (2.4 GHz and 5 GHz) to make High speed an also in other hand for communicate with devices that use 802.11b and g standards . This standard with using of above ways is able to to supports much faster wireless connections over longer distances.also support of multiple radios and antennas that can transmit/receive multiple data streams . send and receive Antenna Antenna configuration configuration in 802.11 N must must be in 1×1, 1×2, 2×2, or 3×3 status these numbers show us how many transmit and receive antennas and radios are in an 802.11n access point (AP) or client. And also when you want to buy a 802.11 N device pay attention to below table .as you see in table in every device
speed is different different and it’s related related to Antenna More Antenna = Higher Speed but I must mention In general multiple antennas do not by themselves increase data rate or range infact Those improvements come from how the MIMO device actually uses its multiple antennas .
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Assumption University Of Thailand – Ali Ghalehban
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
Data Encoding & Rate in 802.11 N
In multi-user multi-user MIMO, a multi-antenna multi-antenna transmitter transmitter communicates communicates simultaneously with multiple receivers This is known as space-division multiple access (SDMA) and because 802.11 802.11 use MIMO for for transmit and receive data data and because MIMO MIMO use multilayer multilayer for working working 802.11 use precoding precoding techniques for this actions actions . Precoding is a generalization of beamforming to support multi-layer transmission
in multi-antenna wireless communications .
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Assumption University Of Thailand – Ali Ghalehban
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
802.11 N Data rate Table Data rates up to 600 Mbit/s are achieved only with the maximum of four spatial streams using one 40 MHz-wide channel. Various modulation schemes and coding rates are defined by the standard and are represented by a Modulation and Coding Scheme (MCS) index value. The table below shows the relationships between the variables that allow for the maximum data rate
20/40 MHz Channels APs and stations stations must exchange exchange information information about the the channels they will use to communicate. In 802.11n, this this is done by sending HT Information and Capabilities Elements to indicate channel width (20 or 40 MHz), primary channel number, and 40 MHz secondary channel channel offset. To promote promote peaceful coexistence, coexistence, an 802.11n AP can can automatically move to another channel or switch to 20 MHz operation if another AP starts operating in either half of the designated 40 MHz channel 5
Assumption University Of Thailand – Ali Ghalehban
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
802.11 N Operation modes There are three 802.11n operating modes: HT : AP using High High Throughput (HT) mode mode also known as as Greenfield mode . Non-HT: AP using Non-HT mode sends all frames in the old 802.11a/g format so that legacy stations can understand them HT Mixed : HT enhancements can be used simultaneously with HT Protection mechanisms that permit communication with legacy stations.
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Assumption University Of Thailand – Ali Ghalehban
[WIRELESS N 802.11 N – ALI GHALEHBAN – ASSUMPTION UNIVERSITY ]
Migration to 802.11 N & 802.11 N in Market
Maybe 802.11 N isn’t enough famous famous between people in social but if everybody everybody be familiar with this standard speed doubtless will move from older standards to this new one Now Now days you can can to find 802.11 802.11 N supported devices in market market is easy and with compare with other standard price is not so high . Here in below I will introduce some company with its 802.11 N supported Device.
Belkin Company wireless broadband router (F5D8320-4)
Linksys WRT300N Wireless-N Broadband Router
TRENDnet TEW-631BRP
NETGEAR WNR834B RangeMax NEXT Wireless-N Router
References: http://en.wikipedia.org/wiki/IEEE_802.11n-2009#Data_encoding http://www.arubanetworks.com/technology/upgrade-to-802-11n/ http://en.wikipedia.org/wiki/IEEE_802.11 http://www.computerworld.com/s/article/9019472/FAQ_802.11n_wireless_networking http://www.everymac.com/systems/apple/apple-tv/apple-tv-faq/what-is-802. http://www.everymac.com /systems/apple/apple-tv/apple-tv-faq/what-is-802.11n-differences-between-802.1 11n-differences-between-802.11n-802.11a1n-802.11a802.11b-802.11g.html
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Assumption University Of Thailand – Ali Ghalehban
