Wimax General

What is wimax How is it different from GSM or others WiMAX setup Wimax Parameters-ranges BW etc Applns Where is it Deployed Who is the operator

Introduction- What is WiMAX •

WiMAX -Worldwide Interoperability for Microwave Access also called as BWA (Broad band Wireless Access)

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WiMAX is one of the hottest broadband wireless technologies around today

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An alternative to wire technologies ( such as Cable Modems, DSL and T1/E1 links

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It operates similar to WiFi but at higher speeds, over greater distances and for a greater number of users

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Has the ability to provide service even in areas that are difficult for wired infrastructure to reach

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Overcomes the physical limitations of traditional wired infrastructure

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High Speed Internet Access

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Provides Wireless transmission of voice, video and data over Microwave RF Spectrum

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The name is given by WiMAX Forum-which promotes interoperability between vendors.

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Point to multipoint

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WiMAX embedded devices -such as mobile phones and WiMAXembedded laptops

Why WiMAX •

Supports very high bandwidth solutions

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Provides wide area coverage and Quality of service to applications l ranging from real-time delay-sensitive voice-over-IP (VoIP) to realtime streaming video and non-real-time downloads

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It is an IP-based wireless broadband technology which can be integrated into both wide-area third-generation (3G) mobile and wireless and wire line networks

WiMAX Network

IEEE 802.16 Standards

Applications •

Connecting Wi-Fi hotspots to the Internet.

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Has replaced cable and DSL

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Provides internet "last mile” broadband access.

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Providing portable connectivity.

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VoIP , e-mail and web browsing at the same time.

WiMAX Architecture

WiMAX Architecture-Reference Model •

IEEE 802.16e-2005 standard provides air interface for WiMAX but not end to end network.

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The WiMAX Forum's Network Working Group (NWG), is responsible for – –

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developing the end-to-end network requirements, architecture, and protocols for WiMAX, using IEEE 802.16e-2005 as the air interface.

NWG has developed a reference model which provides -

architecture framework for WiMAX Deployments

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Interoperability among WiMAX equipment and operators

Reference model/Architecture is IP based. -

Supports - Fixed - Nomadic - Mobile deployments

WiMAX Network ArchitectureExplanation WiMAX Network is logically divided into three parts : 1. 2.

3.

Mobile Stations (MS) used by the end user to access the network. The access service network (ASN), which comprises one or more base stations and one or more ASN gateways that form the radio access network at the edge. Connectivity service network (CSN), which provides IP connectivity and all the IP core network functions.

WiMAX Network

MS

ASN

CSN

Introduction WiMAX

Fixed WiMAX (802.16d)

Mobile WiMAX (802.16e)

• WiMAX system profiles refer to a set of parameters on which a WiMAX network will operate. They include frequency band, channel bandwidth, and duplexing scheme Fixed WiMAX is for fixed applications in LOS and NLOS environments 10 - 66 GHz licensed frequency OFDM/OFDMA OFDM with 256 carriers in licensed 3.5GHz band using channel BW of 3.5 MHz or 7 MHz • And in unlicensed 5.8 GHz band using a 10 MHz TDD channel. • • • •

Fixed WiMAX •

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The first release of Fixed WiMAX profiles has been published by the WiMAX Forum. They are listed in the following table.

Frequency band (MHz)

ChannelizationDuplexing (MHz)

3400 - 3600

3.5

TDD

3400 - 3600

7.0

TDD

The licensed 3.5 GHz band (3400 - 3600 MHz) is the most globally harmonized band for Fixed WiMAX

3400 - 3600

3.5

FDD

3400 - 3600

7.0

FDD

5725 - 5850

10

TDD

• Mobile WiMAX is for portable and mobile applications in NLOS environment. • Frequency selection will affect the quality and cost of the network • The lower frequency bands are generally of preference because they offer propagation advantage, i.e. lower attenuation and longer reach which leads to smaller number of cells required to provide a mobility coverage. • Mobile WiMAX operators are between 1.9 GHz and 2.1 GHz, but those bands have been assigned to 3G operators • WiBro (Wireless Broadband) which is the Korean implementation of IEEE 802.16e, is included as one of Mobile WiMAX profiles. WiBro operates in the 2.3 GHz band over an 8.75 MHz TDD-channel

Release-1 of Mobile WiMAX profiles has been published, as in the following table: Mobile WiMAX profiles cover 5, 7, 8.75, 10 MHz channel bandwidths for licensed spectrum in the 2.3 GHz, 2.5 GHz and 3.5 GHz bands Frequency Bands (GHz) Channelization (MHz)

2.3 - 2.4

2.305-2.32

2.345-2.36

2.496-2.69

3.3 - 3.4

3.4-3.8

5.0

TDD

TDD

TDD

TDD

TDD

TDD

TDD

TDD

TDD

TDD

7.0 8.75

TDD

10

TDD

TDD

TDD

TDD

Table. Mobile WiMAX Release-1 System Profiles (source: WiMAX Forum)

• NLOS Environment

• WiMAX Setup

Fixed and Mobile WiMAX CPE Outdoor CPE, indoor CPE, and PC card

Fixed WiMAX • •

Fixed WiMAX is an alternative to DSL or Cable broad band access. Setup: – Needs outdoor or indoor CPE which consists of antenna, RF interface, modem, and various interfaces for connecting user devices. – CPE with roof-mounted or wall-mounted outdoor antenna offers the best performance

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Uses: – Home or small office networking and Internet connection sharing – Fixed WiMAX also finds its application as backhaul for Wi-Fi hotspots, cellular base stations connection to base station controller

Mobile WiMAX • • •

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• •

Mobile WiMAX vision is to make broadband available everywhere (i.e. at home, in the office, on the street, on car, on train, on vessel). Services like: music/video streaming, live TV broadcast, voice/video chatting, Internet multiplayer game, large file download/upload from/to the Internet, remote access to office LAN via VPN Mobile WiMAX bring broadband access experience to stationary as well as walking users and those traveling at vehicular speed (up to about 120 km/hour) Using devices such as laptop, PDA, and smart phone Higher spectral efficiency

WiMAX Features •

A number of advanced techniques such as • • •

subchannelization, adaptive modulation and coding (AMC), AAS and MIMO

are also incorporated into WiMAX to make better in NLOS environment. •

Subchannelization allows WiMAX to concentrate transmit power on sub-channel(s), increasing the reach of a signal.

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AMC in both downlink and uplink enables WiMAX to adjust modulation and code rate dynamically based on each sub-channel condition and data rate requirement.

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AAS can focus the WiMAX Base Station sector beam to the direction of a user device.

• And MIMO can improve signal strength and throughput significantly with every additional antenna at the BS and the SS. • Uses Scheduling Algorithm: A method by which access is given to utilize a resource. • WiMAX uses a mechanism based on connections between the base station and the user device. Each connection is based on specific scheduling algorithms. • Higher frequencies would decrease the range of a Base Station to a few hundred meters in an urban environment • Uses Antenna or Space Diversity techniques to improve the quality and reliability of a wireless link • HARQ-Hybrid Automatic Repeat Request

Features

WiMAX

802.16d

Fixed WiMAX (the

802.16e

Mobile WiMAX

Data rate

3-70Mbps

Scheduling Algorithm

Yes

end user's wireless termination point is fixed in location)

Frequency Range (Mobile WiMAX) 2-11 GHz range Access Technology

SOFDMA

Multiple Antenna Input Support

MIMO

Access Technology

SOFDMA

Multiple Antenna Input Support

MIMO

Carrier Bandwidth-Fixed WiMAX

3.5 MHz, 5 MHz, 7 MHz and 10 MHz.

Carrier Bandwidth-Mobile WiMAX

5 MHz, 8.75 MHz and 10 MHz

Features

WiMAX

Antenna or Space Diversity Error controlled Methods

HARQ

Fixed WiMAX

512 kbps - 2 Mbps 128 kbps - 1 Mbps (PMP-

Upload rate

Download rate

NLOS)

• WiMAX performance (throughput and range) is determined by many factors: – – – – – – – – –

frequency band channel bandwidth duplexing scheme (TDD or FDD) modulation (whether BPSK, QPSK, 16-QAM, or 64QAM) and code rate antenna types –AAS and MIMO features LOS or NLOS transmit power receiver sensitivity and the number of users per base station sector.

Adaptive Modulation and Coding (AMC) • •

One of the techniques to increase the performance i.e. throughput, capacity, coverage or range, indoor penetration Users with better SNR (closer to the BS) get higher order modulation, those farther from the BS get lower order modulation, ensuring the best performance for each user within the BS coverage.

• Major Limitation: – A commonly-held misconception is that WiMAX will deliver 70 Mbps over 50 kilometers (~31 miles). In reality, WiMAX can either operate at higher bit rates or over longer distances but not both: operating at the maximum range of 50 km increases bit error rate and thus results in a much lower bit rate. Conversely, reducing the range (to <1 km) allows a device to operate at higher bit rates. There are no known examples of WiMAX services being delivered at bit rates over around 40 Mbit/s – Hybrid ARQ performs better than ordinary ARQ in poor signal conditions, but it comes at the expense of significantly lower throughput in good signal conditions

• Manufacturers: o Intel Corporation is a promoter and developer of WiMAX chipsets. o GCT Semiconductor, ApaceWave, Altair Semiconductor, Comsys, Motorola with TI, NextWave Wireless, Wavesat, Coresonic and SySDSoft. o Sequans and Wavesat manufacture products for both clients and network o Texas Instruments, DesignArt, and picoChip are focused on WiMAX chip sets for base stations.

WiMAX Base Station equipment with a sector antenna and wireless modem on top

WiMAX Promises •

The maximum values are 50km coverage under LOS and 8km under NLOS

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In Practice 7-10 km coverage is possible in fixed broad band accesses and 200m-1km in portable devices

• WiMAX 802.16d Indoor CPE

WiMAX Setup • WiMAX subscriber units Indoor and Outdoor versions are available from several manufacturers

Associations • WiMAX Forum -The WiMAX Forum is a non profit organization formed to promote the adoption of WiMAX compatible products and services

• WiMAX Spectrum Owners Alliance- WiSOA was the first global organization composed exclusively of owners of WiMAX spectrum with plans to deploy WiMAX technology in those bands.