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Transcript of WIMAX © 2005 H. H’mimyLecture 11, Slide 1SMU EE 8315 Advanced Topics in Wireless Communications -...
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 1SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Southern Methodist University
EETS 8315 / TC752-N
Advanced Topics in Wireless Communications
Spring2005
http://engr.smu.edu/eets/8315
Lecture 11: WIMAX
Instructor: Dr. Hossam H’mimy, Ericsson [email protected]
(972) 583-0155
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 2SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Announcement
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 3SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMAX forum
• The WiMAX mission is to make the 802.16 interoperable. Just like WiFi did for 802.11.
• No WiMAX compliant products today, foreseen during 2005. The first WiMAX products will be based on 802.16d.
• Intel is the most powerful player in WiMAX forum• Architecture specification work initiated in a new sub-
group
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 4SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMAX forum ..
• FDD as well as TDD
• Licensed as well as unlicensed spectrum – Licensed needed to guarantee wide area service
• No single global spectrum assigned, possibilites:– 5.8 GHz
– 3.5 GHz
– 2.5 GHz, (IMT-2000 more likely in this band)
– 2.3 GHz
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 5SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
38% of US households are interested in a Portable Broadband Service...
7%9% 8%
37%
20%
13%
5%
0%
10%
20%
30%
40%
50%
Definitely
would
not
2 3 Neutral 5 6 Definitely
would
Interest in Portable Broadband Services(n = 3,370 U.S. Broadband Households)
Source: Unlicensed Broadband Wireless: Solutions and Applications© 2004 Parks Associates
38%
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 6SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Broadband Technologies
3G Evolved802.16DSL/Fiber
• Fixed
• Triple Play (Video)• IP Telephony• Internet
• Fixed• Nomadic
• IP Telephony• Internet
• Full mobility• Full roaming• All over the world• POMS• IP Telephony• Internet
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 7SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMAX Standards Roadmap
10 – 66 GHzLOS
Sep 2000
802.16
Some Mobility 2005 ?
802.16e
NOTE: IEEE 802.16 specifies only layer 1 & 2
2 – 11 GHzNLOS
Jan 2003
802.16a
WiMAX = interoperable subset of this (< 6 GHz)
Similar to .16aErrata
Jul 2004
802.16d
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 8SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 9SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
• DSL complement DSL is not available, e.g. poor copper infrastructure DSL OPEX too high, e.g. low population density Central Office is too far away for DSL CLEC bypassing incumbent
• DSL competition If DSL is available, hard to beat
•
802.16
802.16 for Broadband Wireless Access
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 10SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMAX segments, High level pros and cons
• Backhaul, Fixed, point to point – LOS– High Bitrate
– Low Interference
– Clear Signal – No multipath fading
– Relatively Low Cost
• DSL, Fixed up to portable, Point to point, point to multipoint – NLOS– Relative high bitrate, but lower
– One cell
– Still relative cheap
– Low to moderate interference-> Static radio environment • WAN and Mobile environment
– Significantly lower bitrate– High interference. More multipath fading and dopplershift effects
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 11SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
IEEE 802.16 Standard
802.16 802.16d/HiperMAN 802.16e
Completed December 2001 June 2004 (802.16d) Estimate 2005
Spectrum 10 - 66 GHz < 11 GHz < 6 GHz
Channel Conditions
Line of Sight Only Non Line of Sight Non Line of Sight
Bit Rate 32 – 134 Mbps in 28MHz channel bandwidth
Up to 75 Mbps in 20MHz channel bandwidth
Up to 15 Mbps in 5MHz channel bandwidth
Modulation QPSK, 16QAM and 64QAM
OFDM 256 FFT
QPSK, 16QAM, 64QAM
Scalable OFDMA
128 to 2048 FFT
Mobility Fixed Fixed Portable
Channel Bandwidths
20, 25 and 28 MHz 1.75 to 20 MHz 1.75 to 20 MHz
WiMAX
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 12SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WIMAX Features
Feature Benefit
256 point FFT OFDM waveform
Built in support for addressing multipath in outdoor LOS and NLOS environments
Adaptive Modulation and variable error correction encoding per RF burst
Ensures a robust RF link while maximizing the number of bits/second for each subscriber unit
TDD and FDD duplexing support
Address varying worldwide regulations where one or both may be allowed
Flexible Channel sizes (such as 3.5 MHz, 5 MHz, 10 MHz, and so on)
Provides the flexibility necessary to operate in many different frequency bands with varying channel requirements around the world
Designed to support smart antenna systems
Smart antennas are fast becoming more affordable, and as these costs come down their ability to suppress interference and increase system gain will become important to BWA deployments
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 13SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMAX Modulation and Coding
The further the subscriber is from the base station, the greater the likelihood of a lower form of modulation and a higher amount of coding and thus a lower bit-rate
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 14SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Fit with Other Technologies
• Whether 802.16a will complement or clash with certain other technologies remains to be seen. For a while, at least, it will certainly be complementary to 802.11a, enabling Wi-Fi users to dramatically extend their distance from wired networks.
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 15SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Theoretical WiMAX Raw Bandwidth (Mbit/s)*
Modulation /Code rate
1,75 MHz
3,5 MHz
7,0MHz
14,0 MHz
20,0 MHz
1.45
2.91
5.82
11.64
16.26
QPSK 1/2 QPSK 3/4
2.18
4.36
8.73
17.45
24.40
4.36
8.73
17.45
34.91
48.79
16 QAM 3/416 QAM 1/2
2.91
5.82
11.64
23.27
32.53
64 QAM 2/3 64 QAM 3/4
5.82
11.64
23.27
46.55
65.05
6.55
13.09
26.18
52.36
73.19
*OFDM 256 FFT. Includes MAC and preamble overhead
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 16SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Theoretical Coverage (Km)*
Type of Area
Rural
Suburban
Urban
N/A
N/A
Rooftop Antenna
Window/FixedAntenna
<8 Km
Indoor/PortableAntenna
*Approximate distances only, depends heavily on geographical area
<4 Km
<2 Km
<4 Km
<2 Km
<1 Km
<20 Km usingNLOS**
**<50 Km is the theoretical maximum for LOS. Assumption is a NLOS base station and a rooftop antenna for better reception and maximum uplink power
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 17SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Portability (Mobility) in 802.16e
• New network reference model– New BS-BS interface (IB) and BS-server interface (A) defined– Authentication and service authorization (ASA) servers provide
authorization, authentication, billing, management, provisioning and other services. EAP is defined for SIM cards, and other means of Authentication.
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 18SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Enhancements for mobility in 802.16e – Layer 2
• Handover (HO) process defined in MAC including – cell reselection– target BS scanning– network re-entry– HO decision and initiation and HO cancellation.
• MAC messages for each of the handover functions defined.• Broadcast paging message defined.• Neighbor topology advertisement messages defined.• Option of using mobile IP provided. To be defined in May-05. WG
active.• Full QoS supported. All four GSM/WCDMA classes.
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 19SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Enhancements for mobility in 802.16e – Layer 1
• Sleep mode, paging enabled.• Fast time alignment (ranging) mechanism• Flexible FFT sizes depending on channel bandwidth to ensure
OFDM symbol duration is compatible with mobility requirements• Soft handover, i.e., transmit/receive from multiple BS• Fast channel feedback• Fast BSS handover involving maintenance of sync to multiple
BS’ while transmitting/receiving from anchor BS• New MIMO, STC modes
– MIMO soft-handoff based macro-diversity transmission– Space-time codes for 3 antenna configurations. Fixed version has
2 and 4 antenna modes.
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 20SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
some differences
• MAC– 802.11: Contention-based MAC (CSMA/CA), basically
wireless Ethernet.– 802.16: Dynamic TDMA-based MAC with on-demand
bandwidth allocation.• OFDM
– 802.11a: 64 FTTs– 802.16d: 256 FFTs
• Spectrum– 802.11: limited channels in Un-license spectrum– 802.16: multiple channels in licensed & Un-license spectrum
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 21SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
Comparison 802.11 and 802.16
802.11
< 300 feet
Optimized for indoor short range2.7 bps/Hz peak. <= 54Mbps in 20MHz
1-10 CPE CSMA/CA
No QOS
Technology
Range
Coverage
Data rate
Scalability
QOS
802.16
< 30 Mile ( typical 3~4)
Outdoor LOS & NLOS
5bps/Hz peak, <100Mbps in 20 MHz
1- hundreds CPE TDMA
On demand BW voiceVideo, data
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 22SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMAX• Wireless Broadband• Laptop centric• Fixed Portability• Line-of-Sight & Non Line-of-Sight• IEEE Layer 1 & 2 standard• Data optimized• Optimized for Fixed High data rate• Evolution towards mobility
Drivers: • Data optimized network (simple)• DSL complement
Broadband Wireless systems
3G Evolved• Mobile Broadband• Phone & laptop• Full mobility• Non line-of-sight• 3GPP and 3GPP2 standard• Voice/data optimized• Optimized for Mobility• Evolution towards Higher Data
Drivers: • Mobile Broadband for incremental
investment• National & global roaming networks
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 23SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
1xEV-DV
1xEV-DO
HSDPA
EDGE
GSM/GPRS
WCDMA
CDMA2000 1x
Flarion
IEEE 802.16d
Ch
ann
el
Ban
dw
idth
200KHz
5Mhz
1.25 MHz
1.25 MHz
Pea
kb
it-rateD
L
160 kbps
Pea
kB
it-rateU
L
FD
D/T
DD
-20 MHz
480 kbps
2 Mbps
14.4 Mbps
640 kbps
3.1 Mbps
3.1 Mbps
- 75 Mbps
3.2 Mbps
160 kbps
480 kbps
2 Mbps
7.68 Mbps
450 kbps
1.8 Mbps
1.8 Mbps
- 75 Mbps
900 kbps
FDD
FDD/TDD
FDD
FDD
FDD
FDD
FDD/TDD
FDD
FDD
Stan
dard
sco
mp
liant
3GPP
_
Peak Bit Rates Comparison
3GPP
3GPP
3GPP
3GPP2
3GPP2
3GPP2
IEEE
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 25SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
• Propagation difference between 1900MHz and other frequencies ( H-O Model)
• 2100MHz ( Delta = 1.1dB)• 2400MHz ( Delta = 2.6dB)• 3500MHz ( Delta = 7dB)• 850 MHz ( Delta = -12 dB)
WIMAX
© 2005 H. H’mimy Lecture 11, Slide 26SMU EE 8315 Advanced Topics in Wireless Communications - Spring’05
WiMax IEEE802.16a, e
• Understanding WiMax – http://www.intel.com/netcomms/technologies/downloads/305150.pdf– http://www.intel.com/netcomms/technologies/wimax/304471.pdf– http://www.wimaxforum.org/certification/White_Papers/
• OFDM– http://www.intel.com/netcomms/technologies/wimax/303787.pdf
• Adaptive modulation– http://www.intel.com/netcomms/technologies/wimax/303788.pdf