Wimax (802

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    Wimax (802.16)Wimax (802.16)

    Presentation by:Presentation by:

    P.Devendar(07S11A0406)P.Devendar(07S11A0406)

    J.Sandeep(07S11A0444)J.Sandeep(07S11A0444)

    P.Nageshwar rao(07S11A0419)P.Nageshwar rao(07S11A0419)

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    History of WirelessHistory of Wireless

    PhotophonePhotophone

    audio conversations wirelessly overaudio conversations wirelessly over

    modulatedmodulated light beamslight beams limited by the availability of both sunlightlimited by the availability of both sunlight

    and good weatherand good weather

    http://en.wikipedia.org/wiki/Light_beamhttp://en.wikipedia.org/wiki/Light_beamhttp://en.wikipedia.org/wiki/Light_beam
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    WimaxWimax

    WWorldwideorldwide IInteroperability fornteroperability for

    MMicrowaveicrowave AAccccessess

    A certification mark for products that passA certification mark for products that passconformity and interoperability tests for the IEEEconformity and interoperability tests for the IEEE

    802.16 standards802.16 standards

    Run by Wimax ForumRun by Wimax Forum

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    WiMAX is a wireless digital communications

    system, also known as IEEE 802.16, that is

    intended for wireless "metropolitan areanetworks

    WiMAX can provide broadband wireless access

    (BWA) up to 30 miles (50 km) for fixed stations,

    and 3 - 10 miles (5 - 15 km) for mobile stations With WiMAX, WiFi-like data rates are easily

    supported, but the issue of interference is

    lessened. WiMAX operates on both licensed and

    non-licensed frequencies, providing a regulated

    environment and viable economic model for

    wireless carriers.

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    WiMAX is a highly scalable, long-range system,

    covering many kilometers using licensed

    spectrum to deliver a point-to-point connection tothe Internet from an ISP to an end user.

    WiMAX can also be used to Connect many Wi-Fi

    hotspots with each other and also to other parts

    of the Internet.

    When using WiMAX device with directional

    antennas, speeds of10 Mbit/s at 10 km

    distance is possible, while for WiMAX deviceswith omni-directional antennas only 10 Mbit/s

    over 2 km is possible.

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    WiMAX could connect remote Indian villages to

    the Internet using broadband. This would avoid

    hassles in cabling through the forests and otherdifficult terrain only to reach a few people in

    remote places.

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    WimaxWimax

    Goal: Provide high-speed Internet access toGoal: Provide high-speed Internet access tohome and business subscribers, without wires.home and business subscribers, without wires.

    Base stations (BS) and subscriber stations (SS)Base stations (BS) and subscriber stations (SS)

    Centralized access control to prevents collisionsCentralized access control to prevents collisions

    Supports applications with different QOSSupports applications with different QOSrequirementsrequirements

    WiMAX is a subset of IEEE 802.16 standardWiMAX is a subset of IEEE 802.16 standard

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    IEEE 802.16 standardsIEEE 802.16 standards

    802.16.1 (10-66 GHz, line-of-sight, up to802.16.1 (10-66 GHz, line-of-sight, up to134Mbit/s)134Mbit/s)

    802.16.2 (minimizing interference between802.16.2 (minimizing interference between

    coexisting WMANs)coexisting WMANs)

    802.16a (2-11 Ghz, Mesh, non-line-of-sight)802.16a (2-11 Ghz, Mesh, non-line-of-sight)

    802.16b (5-6 Ghz)802.16b (5-6 Ghz) 802.16c (detailed system profiles)802.16c (detailed system profiles)

    P802.16e (Mobile Wireless MAN)P802.16e (Mobile Wireless MAN)

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    Physical layerPhysical layer

    Allows use of directional antennasAllows use of directional antennas Allows use of two different duplexing schemes:Allows use of two different duplexing schemes:

    Frequency Division Duplexing (FDD)Frequency Division Duplexing (FDD)

    Time Division Duplexing (TDD)Time Division Duplexing (TDD)

    Support for both full and half duplex stationsSupport for both full and half duplex stations

    Adaptive Data Burst profilesAdaptive Data Burst profiles Transmission parameters (e.g. Modulation, FEC) canTransmission parameters (e.g. Modulation, FEC) can

    be modified on a frame-by-frame basis for each SSbe modified on a frame-by-frame basis for each SS Profiles are identified by Interval Usage CodeProfiles are identified by Interval Usage Code

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    Time Division Duplexing (TDD)Time Division Duplexing (TDD)

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    TDD Downlink subframeTDD Downlink subframe

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    Uplink subframeUplink subframe

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    Bandwidth requestBandwidth request

    SSs may request bandwidth in 3 ways:SSs may request bandwidth in 3 ways:Use the contention request opportunitiesUse the contention request opportunities

    interval upon being polled by the BSinterval upon being polled by the BS

    Send a standalone MAC message called BWSend a standalone MAC message called BW

    request in an allready granted slotrequest in an allready granted slot

    Piggyback a BW request message on a dataPiggyback a BW request message on a data

    packetpacket

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    PLANPLAN

    I Transmission of the dataI Transmission of the data

    II ARQII ARQ

    III SchedulingIII Scheduling

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    MacMac and physicaland physical layerlayerss

    II ARQII ARQ

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    II ARQII ARQ

    A ARQA ARQ1.1. Stop and WaitStop and Wait

    2.2. Sliding window techniqueSliding window technique

    3.3. Feedback ( go back-N)Feedback ( go back-N)

    4.4. Selective repeatSelective repeat

    B FECB FEC

    C H-ARQC H-ARQ

    D Methods used by WIMAXD Methods used by WIMAX

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    Stop and WaitStop and Wait

    Transmitting

    Data

    1 32 3Time

    Received Data 1 2 3 Time

    ACK

    ACK

    NAK

    Output Data 1 2 3 Time

    Error

    ACK: Acknowledge

    NAK: Negative ACK

    retransmission

    II ARQII ARQ

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    II ARQII ARQ

    A ARQA ARQ1.1. Stop and WaitStop and Wait

    2.2. Sliding window techniqueSliding window technique

    3.3. Feedback ( go back-N)Feedback ( go back-N)

    4.4. Selective repeatSelective repeat

    B FECB FEC

    C H-ARQC H-ARQ

    D Methods used by WIMAXD Methods used by WIMAX

    II ARQII ARQ

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    II ARQII ARQ

    The sliding window techniqueThe sliding window technique

    Without window With a sliding windowWithout window With a sliding windowsize=0 (stop and wait) size=3size=0 (stop and wait) size=3

    Tran

    sm

    itte

    r

    Rec

    ep

    tor

    Tran

    sm

    itte

    r

    Recep

    tor

    II ARQII ARQ

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    II ARQII ARQ

    A ARQA ARQ1.1. Stop and WaitStop and Wait

    2.2. Sliding window techniqueSliding window technique

    3.3. Feedback ( go back-N)Feedback ( go back-N)

    4.4. Selective repeatSelective repeat

    B FECB FEC

    C H-ARQC H-ARQ

    D Methods used by WIMAXD Methods used by WIMAX

    F db k ( b k N)

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    Feedback ( go back-N)Feedback ( go back-N)

    1Time

    NAK

    Time

    Error

    Go-back 3

    2 3 4 5 3 44 5 6 7 5

    1 2 3 44 5

    Error

    NAK

    Go-back 5

    1 2 3 44 5

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    Selective repeatSelective repeat

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    Selective repeatSelective repeat

    1Time

    NAK

    Error

    Retransmission

    2 3 4 5 3 6 7 8 9 7

    1 Time2 4 3 6 8 7Error

    NAK

    Retransmission

    5 9

    1Time

    2 4 3 6 8 75 9

    1Time

    2 43 6 875 9

    II ARQII ARQ

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    II ARQII ARQ

    A ARQA ARQ1.1. Stop and WaitStop and Wait

    2.2. Sliding window techniqueSliding window technique

    3.3. Feedback ( go back-N)Feedback ( go back-N)

    4.4. Selective repeatSelective repeat

    B FECB FEC

    C H-ARQC H-ARQ

    DD Methods used by WIMAXMethods used by WIMAX

    FECFEC

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    FECFEC

    II ARQII ARQ

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    II ARQII ARQ

    A ARQA ARQ1.1. Stop and WaitStop and Wait

    2.2. Sliding window techniqueSliding window technique

    3.3. Feedback ( go back-N)Feedback ( go back-N)

    4.4. Selective repeatSelective repeat

    B FECB FEC

    C H-ARQC H-ARQ

    DD Methods used by WIMAXMethods used by WIMAX

    H-ARQH-ARQ

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    H-ARQH-ARQ

    H-ARQ= FEC+ARQH-ARQ= FEC+ARQ

    FEC: turbo codes/ convolution codes/ blockFEC: turbo codes/ convolution codes/ block

    codes/codes/

    ARQ: selective repeat (SR) / stop and waitARQ: selective repeat (SR) / stop and wait

    (SAW)/ go-back-N (GBN)(SAW)/ go-back-N (GBN)

    II ARQII ARQ

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    II ARQII ARQ

    A ARQA ARQ1.1. Stop and WaitStop and Wait

    2.2. Sliding window techniqueSliding window technique

    3.3. Feedback ( go back-N)Feedback ( go back-N)

    4.4. Selective repeatSelective repeat

    B FECB FEC

    C H-ARQC H-ARQ

    D Methods used by WIMAXD Methods used by WIMAX

    Methods used by WIMAXMethods used by WIMAX

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    Methods used by WIMAXMethods used by WIMAX

    ARQ mechanism is an optional part of theMAC layer in WIMAX.

    WIMAX can use ARQ ,FEC or H-ARQ.

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    SchedulingScheduling

    Radio resources have to be scheduled according toRadio resources have to be scheduled according tothe QOS (Quality of Service) parametersthe QOS (Quality of Service) parameters

    WIMAX Downlink scheduling:WIMAX Downlink scheduling:

    the flows are simply multiplexedthe flows are simply multiplexed the standard scheduling algorithms can be used :the standard scheduling algorithms can be used :

    WRR (Weighted Round Robin)WRR (Weighted Round Robin)VT (Virtual Time)VT (Virtual Time)

    WFQ (Weighted Fair Queuing)WFQ (Weighted Fair Queuing)WFFQ (Worst-case Fair weighted Fair Queuing)WFFQ (Worst-case Fair weighted Fair Queuing)DRR (Deficit Round Robin)DRR (Deficit Round Robin)DDRR (Distributed Deficit Round Robin)DDRR (Distributed Deficit Round Robin)

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    ConclusionConclusion

    Framework for the evolution of wirelessFramework for the evolution of wireless

    broadbandbroadband

    Everything will be coordinated with WimaxEverything will be coordinated with Wimax

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    Queries???