IEEE 802.16 (Wire less MAN)
Name: Ehsan Rohani
Master: Dr. S.M.Fakhraeii
E-mail: e.rohani@ece.ut.ac.ir
Figure Ref. http://www.ieee802.org/16/
Out line:
Abstract
802.16 Features
802.16 PHY Block Diagram
802.16a Features
802.16a – 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 videoservicend es
Broadband access currently dominated byDSL and cable modem technologies
Why BWA?
Advantages of BWA
Ease of deployment and installation
Much higher data rates can besupported
Capacity can be increased byinstalling more base stations
Challenges for BWA
Price
Performance
Interoperability issues
Fixed Broadband WirelessChannels
Cells are less than 10 km in radius
Rooftop or window installed omni-directionalantennas (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 in
October 2001 and published on 8 April 2002
It now has a standard for second generationwireless metropolitan area networks
USA specification designed to provide the"firstmile/last-mile" connection in wirelessmetropolitan 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 ontype 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 January29, 2003, published on April 1, 2003
Roger Marks) The chairman of the 802.16a working group:(
The new IEEE 802.16a standard reshapes the broadbandlandscape. It closes the first-mile gap, giving users aneasily installable, wire-free method to access corenetworks for multimedia applications
802.16 PHY Block Diagram
ErrorControlEncoding
DataSource
OFDMModulator
WirelessChannel
BERTester
ErrorControlDecoding
ChannelEstimator
ChannelEqualizer
OFDMDemodulator
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 addressmultiple access
802.16a – A Viable BWA Solution
2 – 11 GHz range, allows non LoS operation
Licensed and unlicensed spectrum
Key companies manufacturing 802.16aproducts: Soma Networks, IP Wireless, FlarionTechnologies
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 Mesharchitectures 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 ofthe number of subcarriers
References
“Singapore Project DVB-RCT” Israel Koffmann – V.P. MarketingRuncom 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 WirelessMAN™ Air Interface for Broadband Wireless Access” CarlEklund, Nokia Research Center