Wireless System Operation (WiMAX, IEEE 802.16), Wi-Fi and ...

Wireless System Operation (WiMAX, IEEE 802.16),

Wi-Fi and IEEE 802.11

Dr. Md. Mostafizur Rahman

Professor

Department of Electronics and Communication Engineering

Khulna University of Engineering & Technology (KUET)

Worldwide Interoperability for Microwave Access (WiMAX)

Dr. Md. Mostafizur Rahman, ECE, KUET

Presentation

Application

Session

Transport

Network

Data Link

Physical

The Open System Interconnection(OSI) layers


11.1 Cordless Systems

11.2 Wireless Local Loop (WLL)

The Role of WLL

Advantages : - Cost

- Installation Time

- Selective Installation

- Wired Scheme Using existing installed cable

- Mobile Cellular Technology

Different WLL Applications :

- Orthogonal FDM (OFDM)

- Local Multipoint Distribution Service (LMDS)

- Multichannel Multipoint Distribution Service (MMDS)



11.3 WiMAX and IEEE 802.16

With the growing interest in LMDS WLL services, a need was recognized within the industry to

develop standards for tis service. In response to this need the IEEE 802 committee set up the 802.16

working group in 1999 to develop broadband wireless standards. The charter for the group is develop

standard that [MARK99].

Use wireless links with microwave or millimeter wave radios

Use licensed spectrum

Are Metropolitan in scale

Provide public network service to fee paying customers

Use point to multipoint architecture with stationary rooftop or tower-mounted antennas

Provide efficient transport of heterogeneous traffic supporting quality of service (QoS)

Are capable of broadband transmissions (>2 Mbps)


The acronym WiMAX stands for “Worldwide Interoperability for Microwave

Access”. It is based on IEEE 802.16 standard.

IEEE 802.16 is the IEEE standard for Wireless Metropolitan Area Network

(Wireless MAN).

It specifies the air interface for fixed, portable, and mobile broadband wireless

access (BWA) systems supporting multimedia services.

Introduction of WiMAX

WiMAX aims to provide wireless broadband services with a target range of up to31 miles at a transmission rate exceeding 100 Mbps.

It is also to provide a wireless alternative to cable, DSL and T1/E1 for last mileaccess.

The term IEEE 802.16 and WiMAX are used interchangeably.

WiMAX is to IEEE 802.16 what Wi-Fi is to IEEE 802.11


Standard Scope

IEEE 802.16 Medium Access Control (MAC) : One Common MAC for

Wireless Metropolitan Area Network (MAN) standards

Physical layer: 10 – 66 GHz

IEEE 802.16a MAC Modification to 802.16.1, Physical Layer : 2 to 11 GHZ

IEEE 802.16c Detailed system Profiles for 10-66 GHZ

IEEE 802.16e Physical and Medium Access Control Layers for Combined

Fixed and Mobile Operation in Licensed Bands.

IEEE 802.16.2 Coexistence of Fixed Broadband Wireless Access Systems

Table : IEEE 802.16 Standards


Subscriber

Terminal

SNI BNIAir

Interface

Provided

ServerRepeater

(Optional)

BTSSubscriber

Network

Core

NetworkSTS

End to End Delay

Transit Delay

MAC Delay

SNI STS Network Interface

STS Subscriber Transceiver Station

BTS Base Transceiver Station

BNI BTS Network Interface

IEEE 802.16 System Reference Points


IEEE 802.16 Protocol Architecture

The figure od protocol architecture relates the four protocol layers defined in the 802.16

protocol architecture to the Open system Interconnection (OSI) model. Working from the

bottom up, the lowest two layers of the 802.16 protocol model correspond to the physical

layer of the OSI model and include such functions as :

Encoding /Decoding of signals

Preamble generation/removal (for Synchronization)

Bit transmission/reception

Again Physical and transmission layers are the functions associated with providing service

to subscribers. These includes ;

On transmission, assemble data into a frame with address and error detection fields.

On reception, disassemble frame, and perform address recognition and error detection.

Govern access to the wireless transmission medium.

Provide an interface to higher layers and perform flow and error control.


Medium Access Control

Convergence

Transmission

Physical

Digital Audio /

Video Multicast

Digital

TelephonyATM IP

Bridged

LAN

Back

Haul

Virtual Point

to Point

Frame

Relay

OSI data

Link Layer

OSI Physical

Layer

Figure : IEEE 802.16 Protocol Architecture

IEEE 802.16 Protocol Architecture


Medium

Logical Link Control

Medium Access Control

Physical Layer Convergence

Procedure

Physical Medium Dependent

Upper Layer

Protocols

IEEE 802

Reference ModelPresentation

Application

Session

Transport

Network

Data Link

Physical

Medium

OSI Reference

Model

IEEE 802 Protocol Layers Compared to OSI Model




What is Wi-Fi


Wi-Fi Access Point


Wi-Fi Applications


Data Rate Comparison

UMTS: Universal Mobile

Telecommunications Service is a third-

generation (3G) broadband

HSPA: high speed packet access is a

third-generation (3G) mobile broadband


Wi-Fi vs WiMAX


BluetoothBluetooth can be accessed at a number of levels. Bluetooth is both a

communications technology and a communications strategy. As a communication

technology Bluetooth transforms data from an application to radio signals back again. As a

communication strategy Bluetooth is about discovering and linking to other Bluetooth

devices and accessing features on those devices such as audio communications.

This is when the end user will experiences Bluetooth technologies-linking to

headsets and sending data or audio signals between devices. Considerations such as

security and trust will be covered, as will elements such as profiles and classes.

The Bluetooth communications technology is generally handled automatically

by the Bluetooth devices. Unless one is actively designing Bluetooth chips the lower

communications layers will remain hidden from the most end users.


Bluetooth is designed for voice and higher data rate applications

It operates in the 2.4 GHz spectrum

It has a range of up to 10 meters.

It allows for three modes of security.

It has power requirements of about 40 to 100 MW per device.

It can work up to 8 devices.


ZigBeeZigBee is the name given to a specific suite of high level communication

protocols using low power digital radios, based on the IEEE 802.15.4 standard for

Wireless Personal Area Networks (WPANs)

It was formally adopted in December 2004.

It focuses on control applications in industry which do not requires high data rates but

must have low power demand, low cost and offer ease of use.

Offers data rates of 250 Kbits at 2.4 GHz, 40 Kbps at 915 MHz, and 20 Kbps at 868

MHz with a range of 10 - 100m.

It currently offers three levels of security, Costs around half that of Bluetoooth.

Can network up to 256 devices.

Power requirements must lower than Bluetooth.

It uses star, tree or mesh topology.


ZigBee Bluetooth 802.11a 802.11b 802.11g 802.11n UWB

Throughput in Mbps 0.03 1-3 54 11 54 200 200

Max Range (m) 30 10 45 60 60 150 10

Power (mW) 30 100 1500 750 1000 2000 400

Bandwidth (MHz) 0.3 1 20 22 20 40 500

Price (euro) 1 1.5 6 2.5 4.5 10 3.5

Comparison of Wireless Technology


References

Wireless Communications & Networks – William Stallings

Wireless Communications – T S Rappaport


Wireless System Operation (WiMAX, IEEE 802.16), Wi-Fi and ...

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