wimax

Worldwide Interoperability for Microwave Access

Prepared by,•Deval Naik•Rohit Kulkarni•Ashley T•Tushar Sharma•Siddharth Sinha•Sanket Kulkarni

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802.16a(Jan 2003)

• Extension for 2-11 GHz• Non-LOS, Point-to-Multi-

Point applications such as “last mile” access & B/H

802.16(Dec 2001)

• Original fixed wireless broadband air Interface for 10 – 66 GHz, Line-of-sight only, Point-to-Point applications

802.16c(2002)

802.16 amendmentfor Line of Sight,

Point to Point backhaul using spectrum

between 10 - 66 GHz

802.16d(Q3 2004)

• Published as 802.16 –2004, replacing earlier revisions

• Fixed & Portable applications 2 – 6 GHz

• HIPERMAN compatibility

802.16e(Q4 2005)

• Mobility to highway speeds in licensed bands from 2-6 GHz

• Roaming within & between service areas

• WiBRO Compatibility

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Improved Performance Much Greater Distances Much Better MAC NLOS Ability (Non line of sight)

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Broadband Internet Access

Voip , IPTV services

Cellular Phones

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IEEE 802.16 (2001) Air Interface for Fixed Broadband Wireless Access System MAC and PHY Specifications for

10 – 66 GHZ (LoS) One PHY: Single Carrier Connection-oriented, TDM/TDMA MAC, QoS, Privacy

IEEE 802.16a (January 2003) Amendment to 802.16, MAC Modifications and Additional PHY Specifications for 2 – 11

GHz (NLoS) Three PHYs: OFDM, OFDMA, Single Carrier Additional MAC functions: OFDM and OFDMA PHY support, Mesh topology support, ARQ

IEEE 802.16d (July 2004) Combines both IEEE 802.16 and 802.16a Some modifications to the MAC and PHY

IEEE 802.16e (2005) Amendment to 802.16-2004 MAC Modifications for limited mobility

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Coverage range up to 50km and speeds up to 70Mbps (shared among users)

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Source: Understanding WiMAX and 3G for Portable/Mobile Broadband Wireless, Technical White Paper, Intel.

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WiMaxFeatures

High Data Rate

All IP –Based

Network Architecture

OFDM based air interface

Deployment flexibility (System Profiles)

QoS

Mobility

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The duplex scheme is Usually specified by regulatory bodies, e.g., FCC

Time-Division Duplex (TDD) Downlink & Uplink time share the same RF channel

Dynamic asymmetry

does not transmit & receive simultaneously (low cost)

Frequency-Division Duplex (FDD) Downlink & Uplink on separate RF channels

Full Duplexing (FDX): can Tx and Rx simultaneously;

Half-duplexing (HDX) SSs supported (low cost)

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frame

Broadcast

Full Duplex Capable User

Half Duplex Terminal #1

Half Duplex Terminal #2

UPLINK

DOWNLINK

DL

MAPUL

MAP

DL

MAPUL

MAP

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WiMax Forum Board Denotation Purpose

SPWG Service provider working group

To influence ongoing standardization

AWG Application working group To uniquely enrich the system application network

NWG Network working group Responsible for everything beyond the PHY and MAC

TWG Technical working group To provide inter operatibilitybetween MS’s/SS’s and BS’s

CWG Certification working group Issues related to certification

RWG Regulatory working group To provide globally spectrum

MWG Marketing working group Promotion of WiMax forum12

ASN V-CSN

BS

BS

H-CSN

DHCP DHCP

IMS orsimilar

IMS orsimilar

PST N

Internet

HA HA

ROUTER ROUTER

AAA AAA

ASN-GW

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Base Station (BS)

Place from where signals are broadcasted

It cover up to 10 Km, it can reach up to 50 Km if geographical area supports

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ASN-GW (ASN Gateway)

Supports connection management

Mobility across cell sites

Inter service provider network boundary through processing of subscriber control and bearer data traffic

Serves as the Extensible Authentication Protocol (EAP), authenticator for subscriber identity and acts as radius client to the operator’s AAA servers

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AAA

Authentication, Authorization, Accounting

Home Network Service Provider (H-NSP)

▪ Provides backbone for ISP, most web users uses to access internet and ISP connects to Internet Exchange

Session accounting for subscriber sessions

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Home Agent

Provides efficient and scalable mechanism for mobility within the network

Provides temporary IP address to visiting client

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Dynamic Host Configuration Protocol (DHCP) Computer networking protocol use by hosts (DHCP

clients) to retrieve IP address assignments and other configuration information

Uses client server architecture▪ Client sends a broadcast request for configuration information

▪ DHCP server receives the request and responds with configuration information from its configuration database

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IP Multimedia Subsystem (IMS) Provides the foundation for developing and

delivering rich multimedia services and applications

Service Delivery Platforms allow you to expose application programming interfaces (APIs) for all network infrastructure components

Aid the access of multimedia and voice application i.e., create a form of fixed mobile convergence

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Available Bandwidth No . Of Subcarriers ∆f T(b)

1.25 MHz 128 10.94 KHz 91.4 µs

3.50 MHz 512 7.81 KHz 128 µs

5.00 MHz 512 10.94 KHz 91.4 µs

7.00 MHz 1024 7.81 KHz 128 µs

8.75 MHz 1024 9.77 KHz 102.4 µs

10.00 MHz 1024 10.94 KHz 91.4 µs

20.00 MHz 2048 10.94 KHZ 91.4 µs

Typically heavily supported bandwidth are 5 MHz, 7MHz and 10 MHz

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Frequency of all the subcarrier of must be an integer multiple of lowest subcarrier frequency

Capable of multi carrier transmission Supports high speed devices still being

bandwidth efficient Adjacent subcarrier must be orthogonal

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3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3

2 2 2 2 2 2 2 2

2 2 2 2 2 2 2 2

1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1

Time

Subcarrier

Time

Subcarrier

3 3 3 2 3 3 3 3

3 3 3 1 3 3 3 3

2 2 1 2 2 1 2 2

2 1 2 2 1 2 2 3

1 1 2 1 1 1 3 1

1 1 2 2 2 1 1 1

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DlA/Radius

UDP

MS

EAP-XYZ

BS

MAC-CPS

MAC-SS

802.16 Layer-1

Layer-2

IP

DlA/Radius

UDP

Layer-1

Layer-2

IP

ASN-Ctrl

UDP

Layer-1

Layer-2

IP

ASN-Ctrl

UDP

Layer-1

Layer-2

IP

MAC-CPS

MAC-SS

802.16

BS

ASN-GW AAAR1 R3R6

EAP Msgs

ASN-Ctrl

Msgs

MAC-CtrlMsgs

Basic

ClD

Prim Mgmt

ClD

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Each SS has 3 management connections in each direction: Basic Connection:

▪ short and time-urgent MAC management messages

▪ MAC mgmt messages as MAC PDU payloads

Primary Management connection:

▪ longer and more delay tolerant MAC mgmt messages

▪ MAC mgmt messages as MAC PDU payloads

Secondary Management Connection:

▪ Standard based mgmt messages, e.g., DHCP, SNMP, …etc

▪ IP packets based CS PDU as MAC PDU payload

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IP Address Assignment

Simple IP Mobile IP

Proxy MIP

Client MIP

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SSASN-GW(DHCP Relay)

CSN DHCPServer

DHCP DiscoverDHCP Discover

DHCP Offer

DHCP Offer

DHCP RequestDHCP Request

DHCP ACK

DHCP ACK

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Power Consumption

Initial data transfer

Normal mode

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Sleep Mode

Power Consumption

Initial data transfer

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Idle Mode

Power Consumption

Initial data transfer

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WiMaxTraffic classes

UGS RT-VR NRT-VR BE ERT-VR

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UGS

Unsolicitated Grant Service

Fixed rate traffic

You can’t request new more bandwidth once the connection is setup

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RT-VR

Real time variable rate service

Variable rate of traffic allows to change the allocated burst sizes

Rescheduling of bandwidth in any frame is possible

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NRT-VR

Non real time variable rate service

Reservation of some guaranteed rate is mandatory

Delay in sensitive

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BE

Best effort service

Only the maximum data rate is defined

Bandwidth depends on the resources in the cell at a given time

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ERT-VR

Extended real time variable rate service

According to data rate, rescheduling of the bandwidth is possible

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QoSProfile

Unsolicited Grant

IntervalMaximum

Traffic sustain

traffic rate

Maximum latency

Traffic priority

Maximum traffic burst

Unsolicited polling interval

Tolerated Jitter

Minimum reserved

traffic rate

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Handover Types

Hard Handover

Break Before Make

Make Before Break

Soft Handover

RegularFBSS (Fast

BS Switching)

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Authentication

For authentication X.509 certificate at the subscriber station

Privacy and Key Management (PKM) provides service provider authentication

IEEE 802.16e supports the Extensible Authentication Protocol (Optional for service providers)

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Encryption

The AES cipher is available, provides strong support to confidentiality of data traffic

Management frames are not encrypted

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Three potential attacks open to adversaries,

Rogue base station

DoS attacks

Man in middle attacks

Network manipulation with spoofed management frames

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Population: 1.15 Billion people India’s Tele-density

- Overall: 31% Rural: 8.8% Urban: 65% Broadband: 0.4% Internet: 4%

500 Million phone connections byyear 2010

High GDP Growth-8% Increased Income of middle class

(300M) PC Penetration: 2%

The Opportunity in India

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Growth of Telephone Connections

Wireline Wireless Total

The Opportunity in India-Growth Pattern

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Deployment in 3.3-3.4 Ghz band only Most of the deployment are of proprietory

technology or 802.16 d version BSNL has already deployed WiMax ‘802.16 d’

version equipment in ten cities VSNL,Reliance and few other operators/ISPs have

also deployed WiMAX systems mainly for enterprise customers

India WiMAX Environment

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WiMAX 802.16 e technology is still

evolving.

High WiMAX CPE cost

Competitive/Alternate technologies-

3G,HSDPA,LTE, EVDO etc

Low PC Penetration

Less-availability of A.C. power in rural

areas

Challenges

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“Future of eMobility”

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