IEEE 802.16 (Wire less MAN)
description
Transcript of IEEE 802.16 (Wire less MAN)
IEEE 802.16 (Wire less MAN)
Name: Ehsan Rohani
Master: Dr. S.M.Fakhraeii
E-mail: [email protected]
Figure Ref. http://www.ieee802.org/16/
Out line:
Abstract
802.16 Features802.16 PHY Block Diagram
802.16a Features802.16a – A Viable BWA Solution
802.16a Technical Specifications
802.16b Features
Some details about PHY Layer
Abstract
Fixed Broadband Wireless Access (BWA)
Why BWA?
Fixed Broadband Wireless Channels
Combining TDMA and FDMA
TDMA operation
FDMA operation
IEEE 802.16
IEEE 802.16 Issues
Fixed Broadband Wireless Access (BWA)
New “last mile” access technology
Offers high speed voice, data and video servicend es
Broadband access currently dominated by DSL and cable modem technologies
Why BWA?
Advantages of BWA Ease of deployment and installation Much higher data rates can be
supported Capacity can be increased by installing
more base stations
Challenges for BWA Price Performance Interoperability issues
Fixed Broadband Wireless Channels
Cells are less than 10 km in radius
Rooftop or window installed omni-directional antennas (2-10m) at the receiver
15-40 m base station antennas
Variety of terrain and tree density types
TDMA operation
FDMA operation
Combining TDMA and FDMA
TDMA + FDMA operation = OFDMA
IEEE 802.16
IEEE Standard 802.16-2001 [1], completed inOctober 2001 and published on 8 April 2002
It now has a standard for second generation wireless metropolitan area networks
USA specification designed to provide the "firstmile/last-mile" connection in wireless
metropolitan area networks(MAN)
IEEE 802.16
10-66 GHz range, single carrier modulation 2 to 11 GHz region due to be added during 2002
LoS propagation Supports continuously varying traffic levels
54 Mbps data per channel Uses different modulation schemes
depending on type of data and error rates etc
IEEE 802.16 Issues:
LoS not feasible for residential applications
Significant multi path
Outdoor mounted antennas expensive
802.16 Features LMDS in 10 - 66GHz band Point to Multipoint Big block sizes Air Interface designated “WirelessMAN-SC”
SC = Single Carrier Modulation Usually QPSK 32 QAM No OFD
Uplink Access by Time Division Multiple Access (TDMA)
Burst design allows both Time Division Duplex (TDD) and Frequency Division Duplex (FDD)
IEEE 802.16a Features
802.16a approved as a standard on January 29, 2003, published on April 1,
2003Roger Marks) The chairman of the 802.16a working
group:(
The new IEEE 802.16a standard reshapes the broadband landscape. It closes the first-mile gap,
giving users an easily installable, wire-free method to access core networks for multimedia applications
802.16 PHY Block Diagram
Error Control
Encoding
Data Source
OFDM Modulator
Wireless
Channel
BER Tester
Error Control
Decoding
Channel Estimato
r
Channel Equalize
r
OFDM Demodulato
r
IEEE 802.16a Features Non-Line of Sight 6MHz bandwidth in 2 - 11GHZ band 10ms latency requirement 3 Modualtion schemes
WirelessMAN-SC2 Single Carrier modulation
WirelessMAN-OFDM OFDM with 256-point FFT TDMA access
WirelessMAN-OFDMA OFDM with 2048-point FFT Multiple carriers are assigned to multiple receivers to
address multiple access
802.16a – A Viable BWA Solution
2 – 11 GHz range, allows non LoS operation Licensed and unlicensed spectrum
Key companies manufacturing 802.16a products: Soma Networks, IP Wireless, Flarion Technologies
Some details about PHY Layer
802.16a Technical Specifications
Data rates: 4-70 Mbps Bandwidth: 10, 20, 25 MHz Physical layer
Single carrier OFDM with 256 point transform OFDMA with 2048 point transform, multiple
access
MAC: Point to multipoint and Mesh architectures supported
OFDM Receiver
OFDM Modulation Schemes
256 point FFT 200 used (56 guard carriers)
8 pilot carriers (192 data carriers)
Sampling rate: 8/7 of the RF bandwidth
QPSK, 16-QAM and 64-QAM
Cyclic prefix length 1/4, 1/8, 1/16, 1/32 of the number of subcarriers
References
“Singapore Project DVB-RCT” Israel Koffmann – V.P. Marketing Runcom Technologies
Xilinx Solutions for Broadband Technologies
IEEE 802.16 Presentation Submission Template (Rev. 8) 2000-11-08 ,Bob Heise
“IEEE Standard 802.16:A Technical Overview of the Wireless MAN™ Air Interface for Broadband Wireless Access” Carl Eklund, Nokia Research Center