Interview Questions

What is difference between WiMAX and WLAN/WiFi

WLAN testing FAQ

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What is difference between WiMAX and WLAN/WiFi

Both wimax and wlan are mainly used for data communication. Wimax covers greater distance(about 50 km) compare to the WLAN(about 30 m).
WiMAX is short form of Worldwide Interoperability for Microwave Access. WiMAX network consists of wimax base station and wimax subacriber stations. The locations of base stations are decided based on RF link budget and other factors similar to any GSM,CDMA cellular technologies. WiMAX devices are developed according to the IEEE standards 802.16-2004(i.e. 802.16d, OFDM) and 802.16e-2005(i.e. 802.16e,OFDMA). WiMAX supports data rate of about 70Mbps with higher modulation schemes such as QAM. 16d version of wimax is referred as fixed wimax and 16e version of wimax is referred as mobile wimax.
WLAN is short form of Wireless Local Area Network. It is mainly an extension to the normal LAN(Local Area Network) with the advanced wireless devices. The wireless devices in WLAN network is referred as WLAN routers and WLAN Access points or WLAN stations. WLAN devices are developed according to IEEE 802.11 standards which include 11a,11b,11g,11n,11ac,11ad etc. This different flavors of the 802.11 standards are evolving to take care of more data rates and bandwidth.
WLAN has become more pupular than WiMAX, due to less infrastructure cost and application of use. Unlike wimax,wlan is meant for smaller area of coverage and hence its application is limited to organizational premises/building,restaurants,hotels etc. Now-a-days each of this malls,cafes,restaurants provide wifi service so that visitors can make use of the internet facility with the use of the wifi hot spots also referred as wifi kiosks.

Major technical specification differences are mentioned below in the table.

Specifications WiMAX WLAN
IEEE Standard 802.16d,802.16e 802.11
Bandwidth support 3.5MHz,7MHz for 16d(OFDM)
1.75/2.5/3/3.5/5/5.5/7/10MHz for 16e(OFDMA)
20MHz for 11a,20MHz/40MHz for 11n
Frequency bands supported 2.5,3.5 and 5.8GHz supported 2.4 GHz and 5 GHz supported
Data rate About 70Mbps in OFDM case maximum supported data rate is 54Mbps in 11a
subcarrier spacing 90KHz for OFDM and 11.16KHz for OFDMA 312.5 kHz
Cyclic Prefix 1/4,1/8,1/16,1/32 same as WiMAX
IFFT point 256 point FFT for OFDM,
128/512/1024/2048 point FFT for OFDMA
64 point FFT including 48 data and 4 pilot carriers,rest guard carriers and 1 DC
MIMO support Mobile wimax(OFDMA) support MIMO 11n version support MIMO

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