20 Tcil Overview On Wimax

WiMAX Worldwide Interoperability for Microwave Access

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Agenda           

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IEEE Standards View of Wireless Network Technologies Brief on WiMAX WiMAX Forum Usage Models of IEEE 802.16 WiMAX Architecture WiMAX Setup WiMAX Development Stages Problems with other Internet Access Technologies WiMAX Applications Advantages & Disadvantages of WiMAX Comparison between WiMAX & Wi-Fi 2

IEEE Standards View of Wireless Network Technologies WWAN 802.20 (proposed)

WiMAX

New standard for Fixed broadband Wireless. Trying to do for MAN what Wi-Fi did for LAN.

Wi-Fi®

Includes 802.11a/b/g. Products must be Approved for Interoperability by the Wi-Fi Alliance.

MAN 70 Mbps ~50 Km 802.16a/e

WLAN 11-54 Mbps ~100m 802.11a/b/g

PAN ~1.5 Mbps <10 m 802.15.1 (Bluetooth)

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Brief on WiMAX IEEE 802.16 standard Wireless Solution to metropolitian area network (MAN) Evolving standard for PTP & PMP wireless networking Provides QoS Solution for the “Last mile” & “Backhaul” Main Features:

Wireless Speed Broad coverage

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WiMAX Forum Formed in April 2001 It is the group incharge of promoting

& asserting the

interoperability of WiMAX standard Sponsored by IEEE & ETSI Products must comply with the WiMAX standards and document their security and interoperability before receiving Forum endorsement Key Members: Nokia Intel OFDM Ensemble Harris Crossspan Fujitsu

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Services provided by WiMAX Line-of-sight service Line-of-sight between transmitter & receiver 11 GHz to 66 GHz frequency range At Higher frequencies, there is less interference and lots more

bandwidth

Non-line-of-sight Line-of-sight is not required in between a small antenna on CPE

and receiver 2 GHz to 11 GHz frequency range •Longer-wavelength transmissions are not as easily disrupted by physical obstructions – they are better able to diffract, or bend, around obstacles

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Usage Models of IEEE 802.16  Fixed  IEEE 802.16 standard  Portable  IEEE 802.16-2004 standard ( revises & replaces

IEEE 802.16a & 802.16REVd versions)

 Mobile  IEEE 802.16e

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IEEE 802.16

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

Fixed access in LOS connections



Operate in 10-66 Ghz frequency bands



Data bandwidths of 32- 124 Mbps



Cell Radius of 1 to 3 miles



RF channel BW can be 20, 25, 28 MHz



Uses Request/Grant access method



Modulation is adaptive from 64 QAM to QPSK

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IEEE 802.16-2004  Fixed & Portable access in LOS & NLOS  Operate in 2-11 Ghz frequency bands  Data bandwidths of 70Mbit/s  Cell Radius of 4 to 7 miles ( PMP Architecture)  Maximum Range of 30 miles ( PTP Architecture)  Flexible RF channel BW between 1.5 MHz to 20 MHz  Request/Grant access method  Modulation is adaptive from 64 QAM to QPSK

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IEEE 802.16e  Mobile access in NLOS  Operate in 2-6 Ghz frequency bands  Data bandwidths of 50Mbps  Cell Radius of 1 to 3 miles  Mobility upto 120 km/h  Flexible RF channel BW between 1.25 MHz to 20 MHz  Request/Grant access method  SOFDMA technology  Supports Handoff and Roaming

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WiMAX Standards 802.16/c

802.16a/REVd/2004

802.16e

Spectrum

11-66 GHz

2-11 GHz

2-6 GHz

Channel Conditions

LOS

LOS, NLOS

NLOS

Bit Rate

32-124 Mbps

1-70 Mbps

Up to 50 Mbps

Modulation

QPSK, 16QAM and 64QAM

OFDM 256 sub-carriers, QPSK, 16QAM and 64QAM

SOFDMA

Mobility

Fixed

Fixed, Portable

Mobile (upto 120Km/h)

Channel Bandwidths

20, 25 and 28 MHz

Selectable channel bandwidths between 1.5 and 20 MHz

Selectable channel bandwidths between 1.25 and 20 MHz

Typical Cell Radius

1-3 miles

3-5 miles Maximum range 30 miles based on the tower height

1-3 miles

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Broadband Wireless Access 802.16/a Backhaul WiFi

802.16 LOS to fixed outdoor antenna

WiFi

802.16e NLOS to MSS (laptop/PDA.)

802.16a 802.16a NLOS to fixed outdoor antenna

WiFi

NLOS to fixed Indoor antenna

MSS: Mobile Subscriber Station; LOS: Line of Sight; NLOS: Non Line of Sight 26/03/09

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WiMAX Architecture WiMAX Tower (Base Station)

Similar in concept to a cell-phone tower – a single WiMAX BS can provide coverage to a very large area as big as 30 miles WiMAX Receiver (Subscriber Station)

The receiver could be a small box or PCMCIA card, or they could be built into a laptop

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WiMAX Architecture (Contd.) 

The communication path between SS and BS has two directions  

 

A base station can connect directly to the Internet using a high-bandwidth, wired connection It can also connect to another WiMAX tower using a line-of-sight, microwave link.  

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Uplink (from SS to BS) Downlink (from BS to SS)

Often referred to as a backhaul Allows WiMAX to provide coverage to remote rural areas.

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WiMAX Setup  Setup a WiMAX base station  WiMAX-enabled computer or upgrade computer to add

WiMAX capability  Service Provider issues encryption code that would give access to the base station  Base Station would beam data to computer via radio signals  For Local Network, WiMAX base station would send data to a WiMAX-enabled switch, which would then send the data to other computers on that network

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802.16 Network Topology

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WiMAX Development Stages  Fixed Wireless: • Phase 1: Fixed wireless access using outdoor installed antennae providing high speed service to businesses. Also, will serve in a “backhaul” role, linking WiFi hot spots to the Internet. • Phase 2: Introduction of indoor, self-installable Customer Premises Equipment (CPE). Consumers will be able to bring home a box resembling a cable modem, plop it down anywhere in the house and receive high speed service.  Mobile Wireless: 

Phase 3: Manufacturers to integrate WiMAX into PC cards, laptops, and other portable devices to enjoy high speed connectivity at home, around town, and even while speeding down the highway.

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Problems with Current Internet Access Technologies  Cable and DSL technologies





Last Mile Problem: DSL can only reach about 18,000 feet (3 miles) from the central office switch—many urban, suburban and rural locations may not be served.



Many older cable networks have not been equipped to provide a return channel, and converting these network to support high-speed broadband can be expensive.



Cost of deploying cable is a significant deterrent to the extension of wired broadband service in areas with low subscriber density.

Wi-Fi (802.11) access 

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Hot spots are very small, so coverage is sparse.

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WiMAX Applications 

Cellular backhaul Uses PTP antennas to connect aggregate subscriber stations to each other and to base stations across long distances.



Last mile Uses PMP antennas to connect residential or business subscribers to the BS.



Broadband ‘On-demand’ It enables the service provider to offer instantly configurable high speed connectivity for temporary events.

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WiMAX Applications (Contd.) 

Residential broadband: filling the gaps in cable & DSL coverage The range, absence of a LOS requirement, high BW, flexibility and low cost helps to overcome the limitations of traditional wired and proprietary wireless technologies.



Underserved Areas Local utilities and governments work together with a local Wireless Internet Service Provider (WISP) to deliver service.



Mobility IEEE 802.16e allow users to connect to a WISP even when they roam outside their home or business, or go to another city that also has a WISP.

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Advantages of WiMAX          

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Full support for WMAN service Improved user connectivity Longer Ranges High Throughput Higher Quality of Service (QoS) Ensures Interoperability Line of sight not required 802.16e version allows for Mobility Easy Installation lower cost CPE

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Disadvantages of WiMAX 







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Line-of-sight (LOS) is required for long distance (5-30 mile) connections Certain conditions —terrain, weather and large buildings —can act to reduce the maximum range Other wireless electronics can interfere with the WiMAX connection & cause a reduction in data throughput licensed airwave frequencies are limited availability. Unlicensed airwaves are free but all can use them— difficult to control service quality as other users of the same band could cause interference

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WiMAX Forum Frequency Allocation Band

Frequencies

License Required

Availability

2.5 GHz

2.5 to 2.69 GHz

Yes

Allocated in Brazil, Mexico, some Southeast Asian countries and the U.S.

3.5 GHz

3.3 to 3.8 GHz, but primarily 3.4 GHz to 3.6 GHz

Yes, in some countries

Worldwide Available Band, some new allocations between 3.3–3.4 and 3.6–3.8 GHz In most countries, the 3.4 GHz to 3.6 GHz band is allocated broadband wireless.

5 GHz

5.25 to 5.85 GHz

No

5.25 and 5.85 GHz is mainly used for private Networks (Public Utilities and Municipalities)

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Expected players 

 

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Intel is producing chips and currently managing 50 test sites around the country (India) Covad (currently a big DSL provider) Motorola Canopy

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Comparison between Wi-Fi & WiMAX (IEEE 802.11 & IEEE 802.16a)

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Scalability 802.11 Wide (20MHz) channels ■

802.16a frequency

1.5 MHz to 20 MHz width channels. Channel bandwidths can be chosen by operator ■

■ MAC designed to support 10’s MAC designed to thousands of users. of users ■

support

802.16a is designed for subscriber density 26/03/09

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Relative Performance Channel Bandwidth

Maximum Data Rate

802.11

20 MHz

54 Mbps

802.16a

Selectable channel bandwidths between 1.25 and 20 MHz

70 Mbps*

* Assuming a 14 MHz channel

802.16a is designed for metropolitan performance 26/03/09

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Quality of Service (QoS) 802.11 Contention-based MAC (CSMA/CA) => no guaranteed QoS ■

Standard cannot currently guarantee latency for Voice, Video

802.16a Grant-request MAC -TDM (for DL) -TDMA (for UL) ■

■

TDD only – asymmetric

■

802.11e (proposed) QoS is prioritization only ■

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Designed to support Voice and Video ■

TDD/FDD – symmetric or asymmetric ■

Centrally-enforced QoS

■

High Quality of Service

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Range 802.11 Up to100 meters

■

Optimized for indoor performance ■

802.16a Up to 50 Km

■

Optimized for outdoor NLOS performance ■

802.16a is designed for distance 26/03/09

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Security 802.11 Existing standard is WPA + WEP ■

802.16a Triple-DES (128-bit) and RSA (1024-bit) ■

802.11i in process of addressing security ■

802.16a maintains fixed wireless security

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Thank you

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WiMAX Pricing   

PCMCIA WiFi cards - $39.95 CPE – Expect range from $200 to $1,000 Base Stations – Range from $3,000 to $10,000

S.No.

Particulars

1.

Access Point 10 Mbps

80,000

2

Subscriber Module

45,000

3

Cluster Module Management

4

Reflector

8,000

5

Power Over Ethernet

15000

60 Mbps OFDM Radio 26/03/09

Unit Price

1,65,000

8,96,000 35

The 802.16 Protocol Stack

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WIMAX: Physical Layer ■

Two duplex mode ◆ ◆ ◆

■

TDD: Time division duplex FDD: frequency division duplex (Different from TDMA and FDMA)

Support three kinds of physical layer technology ◆ ◆

Single carrier (one channel) OFDM with 256 carriers (IEEE 802.16-2004) ✦ ✦ ✦

◆

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55 (28 low and 27 high) subcarriers are used for guard band 8 subcarriers are used for pilot signal (for channel estimation) 192 subcarriers are for users (192 simultaneous data streams!)

OFDM with 2048 carriers

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IEEE 802.16 MAC layer function

■

Transmission scheduling ■

■

Admission control ■

■

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Provide various levels of bandwidth allocation, error rates, delay and jitter

Fragmentation ■

■

Scans for a channel, synchronizes the SS with the BS, performs registration, and various security issues.

Support for integrated voice/data connections ■

■

Ensures that resources to support QoS requirements of a new flow are available

Link initialization ■

■

Controls up and downlink transmissions so that different QoS can be provided to each user

Sequence number in the MAC header is used to reassemble at the receiver

Retransmission ◆ Implement an ARQ(Automatic Repeat Request)

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Potential Bands 700MHz Narrowband

Public Safety

700MHz

Licensed

900MHz

Unlicensed & Licensed

1.9GHz

Licensed

2.1/2.3GHz

Licensed

2.4GHz

Unlicensed

2.5GHz

Licensed

3.65 – 3.7GHz

Unlicensed

4.9GHz

Public Safety

5.3/5.8GHz

Unlicensed

12.2 – 12.7GHz

Licensed

6,11,18,23GHz

Licensed

38GHz

Licensed

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WiMAX APAC Road Trip ■

WiMAX has had interaction with many different regulatory bodies ◆ US ✦

◆

China ✦ ✦

◆

✦

✦

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Wireless Planning Commission (WPC), Ministry of Telecommunications – decides spectrum policy TRAI – recommends spectrum allocation

Australia ✦

◆

MII – Manages spectrum allocation CWTS – standards body

India ✦

◆

FCC

ACA – manages spectrum allocation Ministry – sets spectrum policy

New Zealand 40

Spectrum by Region

Expected ’05-’07 Deployment Bands

CANADA 2.3, 2.5, 3.5 & 5.8 GHz USA 2.5 & 5.8 GHz Speaker

Name Central & So America Title of Speaker 2.5, 3.5 & 5.8 GHz

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EUROPE 3.5 & 5.8 GHz Possible: 2.5 GHz

MIDDLE EAST AFRICA 3.5 & 5.8 GHz

RUSSIA 3.5 & 5.8 GHz Possible: 2.3, 2.5 GHz

ASIA PACIFIC 2.3, 2.5, 3.3, 3.5 & 5.8 GHz

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Evolution of Wireless Standards The Wi-Fi Alliance is a nonprofit international association formed to certify interoperability of WLAN products based on IEEE 802.11 specification. http://www.wi-fi.org The WiMAX Forum is a non-profit corporation with a goal of promoting deployment of broadband wireless access networks. Forum member companies support the industry-wide acceptance of the IEEE 802.16 standard. http://www.wimaxforum.org

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WiMAX Forum Frequency Allocation 2.5 – 2.6 GHz (Licensed)



The bands between 2.5 and 2.6 GHz have been allocated in the US (MMDS), Mexico, Brazil and some Southeast Asian countries.Also prevalent in Southeast Asia is the 2.3 GHz band, which the Forum expects to cover with the 2.5 GHz radio (in Europe).

3.4 – 3.6 GHz (Licensed)



Worldwide Available Band, some new allocations between 3.3–3.4 and 3.6–3.8 GHz .3.4-3.6 GHz has limited availability.

5.7 – 5.8 GHz (Un-Licensed)



5.25 and 5.85 GHz is mainly used for private Networks (Public Utilities and Municipalities)

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