Wimax

WiMAx

Presented by Nadar sarita rajalingam

f.y.it a28

WHAT IS WiMAX?A fourth generation (4G) Wireless Technology

WiMAX stands for Worldwide Interoperability for Microwave Access

A Broadband Wireless Access (BWA) technique offering fast broadband connections

Founded by Ensemble, Cross Span, Harris & Nokia

A standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL.

The technology is specified by the Institute of Electrical and Electronics Engineers Inc., as the IEEE 802.16 standard subgroup that originally covered the Wireless Local Loop technologies with radio spectrum from 10 to 66 GHz.

WIRELESS NETWORKS Wireless PANs (Bluetooth – IEEE 802.15)

very low range wireless connection to printers etc

Wireless LANs (WiFi – IEEE 802.11) infrastructure as well as ad-hoc networks

possible home/office networking

Multihop Ad hoc Networks useful when infrastructure not available,

impractical, or expensive military applications, emergencies

Wireless MANs (WiMAX-802.16) Similar to cellular networks traditional base station infrastructure systems

MAIN NETWORK ELEMENTS FOR WiMAX

Subscriber Station (SS) , Mobile Subscriber Station(MSS) , Customer Premises Equipment(CPE) , Terminal Equipment (TE) Mobile terminals Portable terminals Fixed terminals

Base-Transceiver Station Access Service Network Gateway(ASN-GW)

Routing the user plane traffic Mobility procedures between BTSs Paging for the subscribers MSSs Performs charging function

Connectivity Service Network Home Agent(CSNHA) Mobile IPv4 Home Agent is the user plane element in the CSN

network that interfaces the Wimax network to other IP networks and services

Manages the hand-overs or relocations between the ASN-GWs Connectivity Service Network Policy & Control Function

Wimax authentication, authorization and charging functionalities at the core network level

IEEE 802.16 -- INTRODUCTION

♣ IEEE 802.16 (2001)♣ Air Interface for Fixed Broadband Wireless Access System MAC and

PHY Specifications for 10 – 66 GHZ (LoS)♣ One PHY: Single Carrier♣ Connection-oriented, TDM/TDMA MAC, QoS, Privacy

♣ IEEE 802.16a (January 2003)♣ Amendment to 802.16, MAC Modifications and Additional PHY

Specifications for 2 – 11 GHz (NLoS)♣ Three PHYs: OFDM, OFDMA, Single Carrier♣ Additional MAC functions: OFDM and OFDMA PHY support, Mesh

topology support, ARQ

♣ IEEE 802.16d (July 2004)♣ Combines both IEEE 802.16 and 802.16a♣ Some modifications to the MAC and PHY

♣ IEEE 802.16e (2005)♣ Amendment to 802.16-2004 ♣ MAC Modifications for limited mobility

802.16 802.16a 802.16-2004

802.16e-2005

Date Completed

December 2001

January 2003

June 2004

December 2005

Spectrum

10-66 GHz

< 11 GHz < 11 GHz < 6 GHz

Operation

LOS Non-LOS Non-LOS Non-LOS and Mobile

Bit Rate 32-134 Mbps

Up to 75 Mbps

Up to 75 Mbps

Up to 15 Mbps

Cell Radius

1-3 miles 3-5 miles 3-5 miles 1-3 miles

IEEE 802.16 STANDARDS

WiMAX TECHNOLOGY

҉�WiMAX is expected to provide fixed, nomadic, portable and, eventually, mobile wireless broadband connectivity without the need for direct LOS(Line Of Sight) with a base station(BS).

҉�In a typical cell radius deployment of three to ten kilometers, WiMAX Forum Certified™ systems can be expected to deliver capacity of up to 40 Mbps per channel, for fixed and portable access applications.

҉�Mobile network deployments are expected to provide up to 15 Mbps of capacity within a typical cell radius deployment of up to three kilometers.

WiMAX ARCHITECTURE & DESIGN☼ Types of WiMAX

☼Fixed WiMAX☼Mobile WiMAX

☼ Wireless Architectural Deployment ☼Point to Point☼Point to Multipoint

WHAT WiMAX WILL OFFER ◙WiMAX based Mobile VoIP handsets are likely to

be priced at around $30 to $50.

◙Reduced tariffs for voice, data, video etc.

◙Reduced maintenance costs.

WiMAX IS WELL SUITED TO OFFER BOTH FIXED AND

MOBILE ACCESS

FIXED WiMAX FOR POINT TO POINT & POINT TO MULTIPOINT

PHYSICAL LAYER Allows use of directional antennas Allows use of two different duplexing

schemes: Frequency Division Duplexing Time Division Duplexing

Support for both full and half duplex stations

Adaptive Data Burst profiles Transmission parameters (e.g. Modulation, FEC)

can be modified on a frame-by-frame basis for each SS

Profiles are identified by ”Interval Usage Code”

HOW WiMAX WORKS͏ WiMax can provide 2 forms of wireless service:

͏ Non-LOS, Wi-Fi sort of service, where a small antenna on a computer connects to the tower. Uses lower frequency range (2 to 11 GHz).

͏ LOS, where a fixed antenna points straight at the WiMax tower from a rooftop or pole. The LOS connection is stronger and more stable, so it is able to send a lot of data with fewer errors. Uses higher frequencies, with ranges reaching a possible 66 GHz.

͏ Through stronger LOS antennas, WiMax transmitting stations would send data to WiMax enabled computers or routers set up within 30 (3,600 square miles of coverage) mile radius.

CHALLENGES TO OVERCOME IN WiMAX DEPLOYMENT

■ RF Interference: Disrupts a transmission and decreases performance. Common forms are multi-path interference and attenuation. Overlapping interference generate random noise.

■ Infrastructure Placement: The physical structure that houses or supports the base station must be RF friendly. A metal farm silo, for example, may distort signals, or a tree swaying in the wind may change signal strength. Obstacles such as trees and buildings frequently block signal paths. High RF activity in the area can cause interference.

SOLUTION FOR THAT CHALLENGES

* Proper network design and infrastructure placement are critical for solving the challenges.

* Subscriber Site Survey, Statistics Gathering, coordination of RF use with neighbouring providers.

* Antennas (Type, Tilt Angles, Array Gain, Diversity Gain)

* Proper design and deployment of the provider’s NOC.

* Well deployed base station or cells with 24/7 access, RF friendly structure, and shielding from weather elements.

IEEE 802.16 MAC – CPS-- MAC MANAGEMENT

CONNECTIONS Each SS(Subscriber station) has 3

management connections in each direction: Basic Connection:

short and time-urgent MAC management messages

MAC mgmt messages as MAC PDU payloads Primary Management connection:

longer and more delay tolerant MAC mgmt messages

MAC mgmt messages as MAC PDU payloads Secondary Management Connection:

Standard based mgmt messages, e.g., DHCP, SNMP, …etc

IP packets based CS PDU as MAC PDU payload

RELATION OF Wi-FI AND WiMAX

WiMax eliminates the constraints of Wi-Fi. Unlike Wi-Fi, WiMax is intended to work

outdoors over long distances. WiMax is a more complex technology and has to

handle issues of importance such as QoS (Quality of Service) guarantees, carrier-class reliability, NLOS.

WiMax is not intended to replace Wi-Fi. Instead, the two technologies complement each other.

USER LEVEL FEATURES• High peak rates• QoS Support• Robust Security• NLOS Capability• Support for any sort of residential or business

communication• Low equipment and subscription costs• Power Saving features• Wide Area Coverage

CONCLUSIONS It is expected that WiMax becomes the dominant

standard for Wireless MAN in the world market, at least, in fixed broadband networks.

WiMax products will have to be delivered to the market needs and those for the end-users will have to be extremely easy to install.

Focus is too often on technologies. Subscriber pay for services, not for

technologies. Technologies enable services, but should not be

a burden on users. Broadband capabilities are important, but

bandwidth is not the only meter to assess service.

REFERENCES IEEE802.16-2004 Alcatel White Paper: WiMAX,

making ubiquitous high-speed data services a reality

Intel White Paper: Understanding WiMAX and 3G for Portable/Mobile Broadband Wireless

WiMAX Forum: www.wimaxforum.com

http://en.wikipedia.org/wiki/WiMax

FOR MORE DETAILS IEEE 802.16-2001. “IEEE Standard for Local and

Metropolitan Area Networks - Part 16: Air Interface for Fixed Broadband Wireless Access Systems”. Apr. 8, 2002.

C. Eklund, R. B. Marks, K. L. Stanwood, and S. Wang, “IEEE Standard 802.16: A Technical Overview of the WirelessMANTM Air Interface for Broadband Wireless Access”, IEEE Communications Magazine, 40(6):98-107, June 2002.

Andrew S. Tanenbaum, Computer Networks, Prentice-Hall India, Fourth edition, 2003.

S. Keshav. An Engineering Approach to Computer Networking. Pearson Education, Sixth edition, 2003.

END OF PRESENTATION