WiMAX (802.16e)

“Worldwide Interoperability Of Microwave Access”

A Road to Mobile Life

BY: Atul Kumar R.n-18(cs-A) SOE ,CUSAT

“WiMAX-we belive it’s the next big thing in the wireless boardband arena”

By:- President of WiMAX group and intel manager[wallst journal,america]

What is Wimax ?

• WiMAX is a telecommunications protocol that provides fixed and fully mobile internet access. The current WiMAX revision provides up to 40 Mbit/s with the IEEE 802.16m update expected offer up to 1 Gbit/s fixed speeds.

Some Wireless Standards• Bluetooth • DECT (Digital Enhanced Cordless Telecommunications) • DSRC (Dedicated Short Range Communications) • HIPERLAN • HIPERMAN • IEEE 802.11 • IrDA • RFID (Radio Frequency Identification) • WiFi • WiMAX • xMax • ZigBee

802.16 Standards History

802.16a(Jan 2003)

• Extension for 2-11 GHz: Targeted for non-line-of-sight, Point-to-Multi-Point applications like “last mile” broadband access

802.16(Dec 2001)

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

802.16c(2002)

802.16 AmendmentWiMAX System Profiles

10 - 66 GHz

802.16REVd (802.16-2004)

(Oct 2004)

• Adds WiMAX System Profiles and Errata for 2-11 GHz

802.16e(802.16-2005)

(Dec 2005)

• MAC/PHY Enhancements to support subscribers moving at vehicular speeds

• First standard based on proprietary implementations of DOCSIS/HFC architecture in wireless domain

The IEEE 802.16 standard forms the basis of 'WiMAX' and is sometimes referred to colloquially as "WiMAX", "Fixed

WiMAX", "Mobile WiMAX", "802.16d" and "802.16e."Clarification of the formal names are as follow:

802.16-2004 ,is also known as 802.16d, which refers to the working party that has developed that standard. It is sometimes referred to as "Fixed WiMAX," since it has no support for mobility.

802.16e-2005, often abbreviated to 802.16e, is an amendment to 802.16-2004. It introduced support for mobility, among other things and is therefore also known as "Mobile WiMAX".

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ISP Network

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HOME LOCAL AREA NETWORK

WiMAX 802.10 transmitter

ISPNetwork

Non Line Of Sight Transmitter

HOW WiMAX WORK

TECHNICAL ASPECTS

Applications of 802.16 Standards

802.16 Network Architecture

Physical Layer SummaryDesignation Applicability MAC Duplexing

WirelessMAN-SC 10-66 GHz Licensed Basic TDD, FDD, HFDD

WirelessMAN-SC 2-11 GHz Licensed Basic, (ARQ), (STC), (AAS)

TDD, FDD

WirelessMAN-OFDM

2-11 GHz Licensed Basic, (ARQ), (STC), (AAS)

TDD, FDD

2-11 GHz License-exempt

Basic, (ARQ), (STC), (DFS), (MSH), (AAS)

TDD

WirelessMAN-OFDMA

2-11 GHz Licensed Basic, (ARQ), (STC), (AAS)

TDD, FDD

2-11 GHz License-exempt

Basic, (ARQ), (STC), (DFS), (MSH), (AAS)

TDD

Wireless Performance(as of 2003)

OFDMA Subchannels

• A subset of subcarriers is grouped together to form a subchannel• A transmitter is assigned one or more subchannels in DL direction (16 subchannels are supported in UL in OFDM PHY)• Subchannels provide interference averaging benefits for aggressive frequency reuse systems

OFDM Basics

Orthogonal Subcarriers

Cyclic Prefix in Frequency Domain Cyclic Prefix in Time Domain

Equalizers are avoided in OFDM

time

Cyclic Prefix Useful Symbol Time

time

Note: All signals & multipath over a useful symbol time are from the same symbol & add constructively (no ISI)

Note: dashed lines represent multipath

Narrow bandwidth long symbol times all significant multipaths arrive within a symbol time minimizing ISI no equalization low complexity

Tx Signal

Rx Signal

OFDMA Scalability

• Supports s wide range of frame sizes (2-20 ms)Source: Intel “Scalable OFDMA Physical Layer in IEEE 802.16 WirelessMAN”

Time Division Duplexing (TDD)

Connections

• 802.16/WiMAX is connection oriented• For each direction, a connection identified

with a 16 bit CID• Each CID is associated with a Service Flow ID

(SFID) that determines the QoS parameters for that CID

PDU Transmission

Source: R. Marks (NIST) IEEE Presentation

Advanced 802.16 Features

• Multiple Input and Multiple Output (MIMO)– MIMO channel capacity is given by C = B log2 det(I + SNR.HH*T/N) where H is MxN channel matrix with M and N are receive

and transmit antennas, resp.• Hybrid-ARQ

– For faster ARQ, combines error correction and detection and makes use of previously received versions of a frame

• Adaptive Antenna System (AAS)– Enables directed beams between BS and SSs

WiBro (Wireless Broadband)

• WiBro is an early large-scale deployment of 802.16 in South Korea (Dec 2005)

• Demonstrates 802.16 performance as compared to 3G/4G cellular alternatives

• 3 operators have been licensed by the government (each spending ~$1B)

APPLICATION

• Cellular backhaul• Boardband on-demand• Residential boardband• Underserverd area• Best connection service

Benefits

• Cost and Investment risk:• Goes where cable and fiber cannot:• Throughput• Scalability• Coverage• Quality of service• Security• interoperability

Conclusion

• WiMAX is not the technology of future; it is already something that being implemented in many area around globe. A good example being WiBRO which is an 802.16 implementation in south korea.

• WiMAX aim to make entire cities wireless