worldwide interoperability for microwave access wi max(ieee 802)
TRANSCRIPT
Worldwide Interoperability for Microwave Access
WiMAX(IEEE 802.16)
by
E. Kishore Kumar
Out line
• 1.History
• 2.Specification
• 3.Architectur
• 4.Physical layer
• 5.MAC layer
• 6.Opetation Network
• 7.Application
• 8.Advntage &Disadvantage
• 9.Conclusion
Why we need broadband wireless access?
• Fill the gap and high data rate wireless LAN and mobile cellular networks.
• Provide high-speed mobile data and telecommunications services
Wireless networks
• Wireless PANs (Bluetooth – IEEE 802.15)– very low range– wireless connection to printers etc
• Wireless LANs (WiFi – IEEE 802.11)– infrastructure range– home/office networking
• Wireless MANs (WiMAX-802.16)– Similar to cellular networks– traditional base station
infrastructure systems
Standards• 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, 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
Introduction
Coverage range up to 50km and speeds up to 70Mbps(shared among users).
Specification
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
Architecture
Physical Layer
• Five physical layer modes
802.16d
802.16e
Designation Applicability
WirelessMAN-SC 10 -66 GHz
WirelessMAN-SCa Below 11GHzLicensed bands
WirelessMAN-OFDM Below 11GHzLicensed bands
WirelessMAN-OFDMA Below 11GHzLicensed bands
WirelessHUMAN Below 11GHzLicensed-exempt bands
Orthogonal Frequency Division Multiplexing (OFDM)
• Multiplexing technique that divides the channel into multiple orthogonal sub channels
• Input data stream is divided into several sub streams of a lower data rate and each sub stream is modulated and simultaneously transmitted on a separate sub channel
• High spectral efficiency, resilient to interference, and low multi-path distortion
Conventional FDM and OFDM
Orthogonal Frequency Division Multiple Access (OFDMA)
• Multiple-access/multiplexing scheme– multiplexing operation of data streams from multiple users– Dynamically assign a subset of sub channels to individual
users• Wireless MAN-OFDMA based on scalable OFDMA
(SOFDMA) – Support scalable channel bandwidths from 1.25 to 20 MHz
MAC Layer
Service Specific Convergence Sublayer
MAC Common Part Sublayer
Privacy Sublayer
Interface to higher layer protocols, classifies incoming data, etc.
Core MAC functions (i.e., scheduling, connection maintenance, fragmentation), QoS control
Encryption, authentication, secure key exchange
Network Operation
Applications
• According to WiMax Forum it supports 4 classes of applications:
1. Multi-player Interactive Gaming.
2. Video Conference.
3. Web Browsing and Instant Messaging.
4. Media Content Downloads.
Advantage
• Low cast.• It can support: NLOS(non line of set)&LOS. Mesh Network. Point to Multipoint. Handoff Technique.• Coverage:50Km.• Max Data Rate:70Mpbs.
Disadvantage
• Interference issues.
• It is not work proper in weather.
Features
• Use wireless link with microwave or millimeter wave radios.
• Use licensed spectrum
• Use point-to-multipoint architecture, tower-mounted antennas
• Provide broadband and QoS, data transmissions.
Conclusions
• WiMax becomes the dominant Wireless MAN in the world market.
• The end-users will have to be extremely easy to install.
• Focus is too often on technologies – Subscribers pay for services, not
technologies – Broadband capabilities are important, but
bandwidth is not the only meter to assess service
Querries?
Thank u.
References
• IEEE802.16
• 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