WiMAXWiMAX

OutlineOutlineIntroductionWhy WiMax is developedTypical Network RangesWiMax Components.WiMax Network ArchitectureWorkingRelationship with other WirelessSecutiry Issues and UsesAdvantages and DisadvantagesFuture develpoment and IEEE

802.20

What is WiMAX ??

WiMAX (Worldwide Interoperability for Microwave Access) is a telecommunications protocol that

provides a fixed and a wireless Internet connection. It is also called as Broadband wireless Technology. It is

the Wireless alternative to DSL cable network.

WiMAX is a wireless Internet service designed to cover wide geographical areas serving large number of users at low cost.

WiMAX is the synonym given to the IEEE 802.16 standard defining wide area wireless data networking .

It is the possible economic model for wireless carriers, where it is not possible to other Technology. That is it can be deployed

in low cost compared to GSM and CDMA.

Why WIMAX is developed?

Wi-Fi is the best in the local area network. But it cannot be used in the Large Area Network such as MAN (Metropolitan Area Network). To overcome the disadvantage of the Wi-Fi the developers are concentrated to develop new technology. Finally they developed the WiMAX technology based on the Scalable Orthogonal Frequency-division Multiple Access (SOFDMA). The SOFDMA offers the services very cheaper, very effective and easy implementation.Now many devices are come with the WiMAX technology. Many mobile companies launch their Mobiles with this technology. Many ISP's also providing WiMAX USB internet Modem for Internet Connectivity.

Founder of technology:

The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL".[2] IEEE 802.16m or WirelessMAN-Advanced is a candidate for the 4G, in competition with the LTE Advanced standard. 

WAN IEEE 802.16eIMT-2000(3G)(Nationwide)

MANIEEE 802.16-2004

ETSI HiperMAN/WiMAX(50 Km)

LANIEEE 802.11 (a,b,g)

(150 m)

PANIEEE 802.15Bluetooth

(10m)

Typical Network RangesTypical Network Ranges

Wide Area Network

Metropolitan Area Network

Local Area Network

Personal Area Network

WiMax Base StationWiMax Base StationWimax base station consist of

wimax tower. The common range of wiMax base station is up to 10 km radius.while base station cover 50 km or 30 miles but in practice it is 10 km and 6 miles only.

Any code inside the coverage area would be capable to access the internet.

WiMax Receiver:WiMax Receiver:A WiMAX receiver may have a

separate antenna or could be a stand-alone box or a PCMCIA card sitting in your laptop or computer or any other device. This is also referred as customer premise equipment (CPE).

WiMAX base station is similar to accessing a wireless access point in a WiFi network, but the coverage is greater.

WiMax AnteenaWiMax AnteenaWimax anteena is also a

standalone box and sits on your laptop or computer.

Wimax anteena is just like a WiFi network wireless network.

Wimax anteena connected with the indoor unit via wire to make storage signal.

BackhaulBackhaulA WiMAX tower station can connect directly to the

Internet using a high-bandwidth, wired connection (for example, a T3 line). It can also connect to another WiMAX tower using a line-of-sight microwave link.

Backhaul refers both to the connection from the access point back to the base station and to the connection from the base station to the core network.

It is possible to connect several base stations to one another using high-speed backhaul microwave links. This would also allow for roaming by a WiMAX subscriber from one base station coverage area to another, similar to the roaming enabled by cell phones.

WiMAX

WiMAX

WiMAX

WIMAX network Architecture:

HOW DOES IT WORK ?HOW DOES IT WORK ?

• WiMAX uses microwave radio technology to connect computers to the internet in place of wired connections such as DSL or cable

modems.

• It works very much like cell phone technology in that reasonable proximity to a base station is required to establish a data link to the

Internet.

• Users within 3 to 5 miles of the base station will be able to establish a link using NLOS technology with data rates as high as 75 Mbps.

• Users up to 30 miles away from the base staion with an antenna mounted for LOS to the base station will be able to connect at data

rates approaching 280 Mbps.

Forms of Wireless Service

• NLOS (Non Line of Sight)Wi-Fi sort of service

• LOS ( Line of Sight)

WiMAX

Fixed WiMAX(IEEE 802.16-2004)Ex: ETSI HiperMAN

• Optimized for Fixed and nomadic applications

in LOS and NLOS environment

• 10-66 GHz licensed frequency bands (LOS)

• Licensed and license-exempt sub 11 GHz bands (LOS & NLOS)

Mobile WiMAX(IEEE 802.16e)

Ex: WiBro

• Optimized for Portable and mobile applications in NLOS

environment

• Sub 6 GHz bands

Customer Premise Equipment

Wireless PMP Access

Base Station

PtP WirelessBackhaul

Traffic Aggregation

Central Office,Network Management,VOIP Server etc.

System for 802.16 WiMAXSystem for 802.16 WiMAX

Internet Backbone

Telco core network orPrivate (fiber) network

Non-Line-of-sight, point-to-multipointOr point-to-point backhaul : 802.16aNon-line-of-sight,

Point-to-multipoint: 802.16a

Access Point

802.11

A TYPICAL WiMAX AND WiLAN DEPLOYMENT

ISP PoP

Wi-Fi Hotspots

WiMAX PTP backhaul

WiMAX Point-To-Point backhaul

ISP PoPWire line or Wireless backhaul

WiMAX Base Station

WiMAX point-to-multipoint

Homes with outdoor/indoorWiMAX receiver

Point to Multipoint application

WiMAX as the backbone of meshed networks

WiMAX may enjoy a complementary relationship with Wi-Fi due to differences in the reach of each of the networks . WiMAX connections can be used to provide backhaul

connections to Wi-Fi hotspots over longer distances. WiMAX could also play a key role in connecting Wi-Fi hotspots in a mesh-type network to quickly increase

coverage and capacity.

Wi-Fi

WiMAX

How it is different from WI FI?

WiFiWi-Fi is based on IEEE 802.11 standard. Wi-Fi typically provides local network access for a few hundred feet with the speed of up to 54 Mbps.Wi-Fi works at 2.7 bps/Hz and can peak up to 54 Mbps in 20 MHz channel.Wi-Fi does not guarantee any QoS

WiMaxWiMAX is based on IEEE a single WiMAX antenna is expected to have a range of up to 40 miles with the speed of 70 Mbps or more.WiMAX works at 5 bps/Hz and can peak up to 100 Mbps in a 20 MHz channel.WiMax will provide your several level of QoS.

Reference Model

• Supports multiple services (e.g. IP, voice over IP, video)

simultaneously, with different QoS priorities

PHY LayerPHY Layer • Burst single-carrier modulation with adaptive data burst profiles – Transmission parameters (e.g. modulation and FEC settings)

can be modified on a frame-by-frame basis for each SS. – Profiles are identified by ”Interval Usage Code” (DIUC and UIUC) • On downlink, multiple SS's can associate the same DL burst • On uplink, SS transmits in an given time slot with a specific

burst • Allows use of directional antennas – Improves range • Allows use of two different duplexing schemes: – Frequency Division Duplexing (FDD) – Time Division Duplexing (TDD) • Support for both full and half duplex stations

Time Division Duplexing Time Division Duplexing (TDD)(TDD) In case of TDD both uplink and downlink transmissions share the same frequency but are separated on time ● A TDD frame has a fixed duration and also consists of one uplink and one downlink frame ● TDD framing is Adaptive

MAC LayerMAC LayerWireless MAN: Point-to-Multipoint andoptional mesh topology• Connection-oriented– Connection ID (CID), Service Flows

(FS)● MAC layer is further subdivided intothree layers– Convergence sub-layer (CS)– Common part sub-layer (CPS)– Privacy sub-layer

Factors affecting WiMAX performance (throughput and range)

• Frequency Band on which it is operating

• Channel Bandwidth

• Duplexing Scheme (TDD or FDD)

• Modulation (BPSK, QPSK, 16-QAM or 64-QAM) and Code Rate

• Antenna Types

• Whether LOS or NLOS

•Transmit Power

• Receiver Sensitivity

• The no. of users per base station sector.

Relationship with other Wireless Technologies

3G3G Mobile-FiMobile-Fi Wi-FiWi-Fi WiMAXWiMAX

Max. SpeedMax. Speed 2 Mbps2 Mbps 16 Mbps16 Mbps 54 Mbps54 Mbps 100 Mbps100 Mbps

CoverageCoverage Several MilesSeveral Miles Several MilesSeveral Miles 300 feet300 feet 50 miles50 miles

AirwaveAirwave LicensedLicensed LicensedLicensed UnlicensedUnlicensed EitherEither

AdvantagesAdvantages Range, Range, MobilityMobility

Speed, Speed, MobilityMobility

Speed, PriceSpeed, Price Speed, Speed, RangeRange

DisadvantagDisadvantageses

Slow, Slow, ExpensiveExpensive

High PriceHigh Price Short RangeShort Range Interference Interference issuesissues

Security Issue

• Every WiMAX traffic is encrypted using DES (Data Encryption Standard) or AES (Advanced Encryption Standard) for securing its transmission over the

air.

• The encryption keys are distributed from the BS to the SSs using PKM ( Privacy Key Management) protocol to ensure that only authorized SSs can

receive the keys.

• Every WiMAX user device is authenticated using a digital certificate or SIM ( Subscriber Identity Module).

This way, WiMAX keeps user traffic from eavesdropping and protects operator or service provider from becoming a victim of bandwidth theft by

unauthorized users.

USES

1) Connecting Wi-Fi hotspots with each other and to other parts of the internet.

2) Providing a wireless alternative to cable and DSL for last km broadband access.

3) Providing a high-speed mobile data and telecommunications services (4G).

4) Providing a diverse source of Internet connectivity as a part of business continuity plan.

5) Providing Nomadic connectivity.

What are the Advantages ?• A Single WiMAX main Station can serve hundreds of users.

• Endpoints install within days instead of the weeks required for wired connections.

• Data rates as high as 280 Mbps and distances of 30 miles are possible.• Users can operate mobile within 3-5 miles of a base station at

data rates up to 75 Mbps.• No FCC radio licensing is required.

• Less expensive than DSL or coaxial cable.

What are the disadvantages ?• Line-of-Sight is required for long distance (5-30 mile) connections.

• Heavy rains can disrupt the service.• Other wireless electronics in the vicinity can interfere with the WiMAX

connection and cause a reduction in data throughput or even a total disconnect.

Advantages over Wi-Fi

The WiMAX specification provides symmetrical bandwidth over many kilometers

and range with stronger encryption and typically less interference. Wi-Fi is short

range has WEP or WPA encryption and suffers from interference as in metropolitan areas there are many users.

The fastest Wi-Fi connection can transmit up to 54 Megabits per second under optimal conditions. WiMAX can handle up to 70 Megabits per second.

The biggest difference isn’t speed; its distance. WiMAX outdistances Wi-Fi by miles.Analysis

WiMAX is not competing other, it is wireless cable replacement technology, which

competes with wired operators.

Future developments and IEEE 802.20

MBWA is a technology developed by IEEE 802.20. It is the future technology standard for true wireless broadband or 4G and so far iBurst is the only pre-selected solution with over a dozen commercial deployments worldwide.