wimax priya

8/8/2019 WiMAX Priya

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By Murthy. Priyanka. M.



AgendaIntroductionWhy Wireless?

Comparison between IEEE 802.11 and 802.16WiMAX ApplicationsWiMAX ArchitectureWiMAX MAC

WiMAX PHYDisadvantages of WiMAXFuture Developments



IntroductionWorldwide Interoperability for Microwave Ac ce s sprovides wireless data over long distances in a variety of

ways (point-to-point links to full mobile cellular typeaccess)

based on the IEEE 802.16 standard (WirelessMAN)



Why Wireless?Where wires cannot be physically installedWhere wires cannot be economically

justified (Wireless is cheaper)Where Mobility is a factor



Wireless Technologies- Big picture



IEEE 802.11 vs. 802.16802.11 802.16

Range Optimized for 100m Optimized for 7-10km upto50kmMultipath delays tolerated

Coverage Optimized for indoor Optimized for outdoor, Adaptive Modulation, Advanced Antenna

Scalability Fixed 20 MHz channel 1.5 MHz to 20 MHz Channels

MAC Contention based Grant based

QOS Simple Sophisticated



IEEE 802.16 (WiMAX)Provide broadband wireless access up to50km.coverage area--- Urban area, Suburban area,Rural area

Types of Wireless Access--- Fixed Wireless Access,Portable or Nomadic Wireless Access, Mobile Wireless AccessExpected speed (From WiMAX Forum)--- 40Mbps for fixed and nomadic wireless access, 15 Mbps for mobile

wireless accessSpeed is depending on--- Channel Bandwidth(1.75 to20MHz), Modulation schemes, Error correcting code



IEEE 802.16 Applications



IEEE 802.16 ApplicationsLast mile connection to home and small office(comparing to DSL and cable modem)

WiMAX connection for enterprise (replace lease line)Wi-Fi hotspot backhaulCellular backhaulPublic safety services

Broadband Internet Access



How WiMAX works?



IEEE 802.16 System Architecture



IEEE 802.16 ArchitectureSS/MS: the Subscriber Station/Mobile Station

ASN: the Access ServiceNetworkBS: Base station, belongsto ASNCSN: the ConnectivityService NetworkNAP: a Network AccessProvider NSP: a Network ServiceProvider



IEEE 802.16

Communication link between the mobile stationand active base station.



IEEE 802.16 MAC



802.16 MACTwo directions ± uplink and downlinkTwo duplex schemes ± FDD (Frequen cy Divi s ionDuplex) , TDD (Time Division Duplex)One Duplex Scheme ± TDMA (Time Division Multiple

Access)



IEEE 802.16 MAC

Two directions ± uplink and downlinkTwo duplex schemes ± FDD(Frequency DivisionDuplex), T DD ( T ime Divi s ion Duplex)One Duplex Scheme ± TDMA (Time Division Multiple

Access)



IEEE 802.16 PHY

Based PHY Technologies--- Single Carrier, OFDM(Orthogonal Frequency Division Multiplexing)-FixedBWA, OFDMA (Orthogonal Frequency DivisionMultiplexing Access)-Mobile BWABenefits of OFDM, OFDMA--- High Spectral Efficiency,Provide high speed



IEEE 802.16 PHY

Modulation S ch eme s ± QPSK, 16QAM,64QAM

Forward Error Corre c tion (FEC)



IEEE 802.16 PHY



IEEE 802.16 PHY

AAS ( Adaptive Antenna S ys tem)



Disadvantages of WiMAX

1 ) Line of sight is needed for longer connections

2 ) Weather conditions like rain could interrupt the signal.

3) 0ther wireless equipment could cause interference.

4) Multiplied frequencies are used.

5) WiMAX is very power intensive technology andrequires strong electrical support.



Thank You

wimax priya

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