WiMAX: 4G or Never ?
BeyondSpot Technology
April. 2005
page
1
BeyondSpot Proprietary
WiMAX Topic
Highlight

What is WiMAX? (or “Mobile WiMAX” more precisely)

WiMAX is a marketing term, a certification body, or an industry ad-hoc
forum to complete IEEE 802.16 standard (marketing, regulatory,
interoperability, test, certification, and high level protocol)
 IEEE 802.16 also known as BWA or WirelessMAN
 WiFi  IEEE 802.11 (WirelessLAN) = WiMAX  IEEE 802.16

Why chose such topic?

mobility extension started in late 2002
 WiMAX is recognized as one of the new
competitions to CDMA based 3G
 Other competitions are proprietary
technologies, WiFi, Mesh, or IEEE 802.20

CDMA?
OFDM?
Can WiMAX be 4G or Never?

OFDM/OFDMA based broadband mobile is
recognized as 4G (beyond 3G)
 This presentation shares our story
page
2
BeyondSpot Proprietary
WiMAX Topic
Drivers from Two Worlds

Broadband Access is a merging process

Legacy Cellular, led by 3GPP and 3GPP2, extends bandwidth to support
broadband data services, especially in IP format.
 Fixed Wireless, led by IEEE, enhances techniques to support mobility.
 3GPP (UMTS/WCDMA) and 3GPP2(CDMA2000) started from ITU IMT-2000.
Market Size
1 Billion
Subscriber
Broadband
Mobile
Access
300 Million
Subscriber
Data
Cellular
1 Billion
Users
Internet
1998
page
3
200 Million
Users
2010
BeyondSpot Proprietary
WiMAX Topic
Migration of WiMAX
Data Rate
SOC
Available
Standard
Maturing
Standard
Maturing
Fixed WiMAX
IEEE 802.16d
2005
Portable WiMAX
Nomadic WiMAX
IEEE 802.16d/e
2006?
Mobile WiMAX
IEEE 802.16e
2007?
Mobility
page
4
BeyondSpot Proprietary
WiMAX Topic
802.16e Compatibility with 16d

802.16e is the mobile extension from 802.16

Modification in PHY from OFDM to Scalable OFDMA
 Modification in MAC for security, handoff, roaming, & resource management
Convergence Sub Layer
IP
Ethernet
Packet
Classifier
ATM
Header
Suppression
MAC Layer
Net Entry
PDU
Generation
ARQ
PHY Burst
Scheduling
PDU
Reassembly
Security/Privacy
Key, AES, EAP
Connection
Management
Handoff
Bandwidth
Management
Power Mgnt
Sleep/Idle
PHY Layer
SC
10-66GHz
802.16d
page
5
SCa
2-11GHz
OFDM
2-11GHz 256FFT
802.16e
OFDMA
OFDMA 2-11GHz (PAR <6GHz)
128, 256, 512,1024, 2048
2-11GHz 2048FFT
WiMAX
BeyondSpot Proprietary
WiMAX Topic
Players in WiMAX Forum

WiMAX SOC/System Pairs (examples)
Intel  Proxim, Alvarion, ZTE, Alcatel,…
 Fujitsu  WiLAN, Aperto
 Wavesat  ATMEL
 LG Nortel… and more


WiMAX Forum has >200 members

Marketing, technical, interoperability and
spectrum
Alliance
Fixed/Nomadic
Portable/Mobile
IEEE802.16 2004 and TGe
And a lot more…..
Air Interface standard
page
6
BeyondSpot Proprietary
WiMAX Topic
A Million Dollar Question

Can WiMAX (16e) be the broadband candidate after 3G?


or just an idea that sounds great but never comes true?

page
WiMAX brings higher throughput and longer range, it is a growing threat to
the deployment of 3G and the promised ROI in every 3G business model
7
WiMAX inherits issues of 3G and has even more challenges in spectrum, the
following presentation provides a balanced view
BeyondSpot Proprietary
WiMAX Topic
Advantages in Multipath

OFDMA carries advantages in “Multipath”

CDMA uses the whole spectrum, wasting system resource to combat
frequency selective fading.
 CDMA also creates worse interference problem
 OFDMA only select subcarriers with less channel degradation, prevent
wasting system resource (power or throughput ) => achieving higher system
capacity.
Multipath
Signal Sent
Signal Received
page
8
BeyondSpot Proprietary
WiMAX Topic
Spectral Efficiency Wins

Spectrum efficiency is an important factor for data service

The scarce of available (or useful) spectrum makes efficiency a key
factor to approve spectrum and the success of business model.
 Regulatory bodies shall recycle spectrum for existing systems with low
spectral efficiency.
 Future systems with high spectrum re-use advantages or higher
spectral efficiency shall have favored allocation during application.


2.5G TDMA: Very
limited data rate and
low spectral efficiency
(1.0-1.5 bps/Hz)
3G WCDMA: Reasonable
data rate, range, and
mobility, improved
spectral efficiency
(1.5-2.5 bps/Hz)
5MHz
500kHz


WiFi: OFDM 64FFT,
Reasonable data rate,
limited range and
mobility, improved
spectral efficiency
(2-3 bps/Hz)
WiMAX:OFDMA, Up to
2048FFT much
improved range and
mobility, potential for
best spectral
efficiency (3-4 bps/Hz)
15 MHz
page
9
BeyondSpot Proprietary
20 MHz
WiMAX Topic
Global Harmonization

WiMAX has global harmonization

WiMAX forum pushes harmonization between IEEE and ETSI; there is only
one WiMAX standard (ETSI has not fully adopted Mobile WiMAX yet)
 WiMAX share one MAC for all, fixed, portable, and mobile

3G breaks into WCDMA (3GPP), CDMA2000 (3GPP2), and more

Among WCDMA, venders has their own proprietary modes.
 China has TDS-CDMA, US has UWC-136, and Japan has DoCoMo 3G…
WCDMA
page 10
CDMA2000
BeyondSpot Proprietary
WiMAX Topic
Local Optimization is Better

Future terminal can handover among multiple standards

Thanks to high integration of silicon, dual-/tri- mode terminals are practical.

Each standard is optimized for a specific environment, saving resource.

Avoid sacrificing power to support indoor users.
WiFi
WiMAX
page 11

802.11 covers indoor users

802.16d covers fixed outdoor

802.16e covers moving vehicles
BeyondSpot Proprietary
WiMAX Topic
VoIP Changes Telecomm

VoIP changes everything !

The growing popularity of VoIP triggers the demand for IP based access
and changes the landscape of telecomm
 3G products are compatible with traditional circuit based PSTN and
PSMN, while 4G may only need to support VoIP with gateway and
gatekeeper separately purchased
Cellular Phones
POTS Phones
Circuit Based
Voice Network
(PSTN)
Circ
u
Con it based
nect
ions
VoIP To
PSTN
Gateway
IP Based
Voice Network
VoIP
Fixed
Phones
Circuit Based
Cellular Network
(PSMN)
VoIP to
PSMN
Gateway
POTS
Phones
VoIP
Terminal
VoIP
Mobile
Phones
page 12
PC to Phones
BeyondSpot Proprietary
WiMAX Topic
Regulatory Difficulty

VoIP over WiMAX has no obligation to secure QoS

From architecture point of View VoIP challenges Traditional Telecom
Regulatory Model. Is it an application or a telecomm service?
 When voice is no longer consider as telecommunication service, it is not
bounded for availability, emergency service (911), or voice quality of service
 It is a pure low cost application, not a telecom service

VoIP Can Not
Address:
Application

99.999% availability
 The high quality of
voice support as 3G
 The same level of
robustness as
circuit
 The same level of
QoS as circuit
page 13
TCP/IP
Voice
Voice
Application
TCP/IP
Voice
Transport
Transport
BeyondSpot Proprietary
Transport
WiMAX Topic
Power and RF Constraint

Battery Life Challenge

WiMAX standard was targeted to long range (high power), fixed (nonbattery based), or portability (recharged daily), not mobility.
 Higher data rate demands higher power transmission; battery
technology show difficulty to catch up with the such demand.
 Power consumption of WiMAX device could be a major problem.

802.16’s Effort in
Power/RF
OFDM Symbol Power
Peak Power

Power-Saving mode
and Scalable OFDMA
are added to 802.16e
 But higher FFT has
more severe PAPR
(peak to average
power ratio)
 Challenge the RF
design for WiMAX
page 14
Average Power
Guard Interval
BeyondSpot Proprietary
IFFT Symbol Duration
Time
WiMAX Topic
Hi Layer Protocol Integration

High Layer mobility is a challenge

IEEE 802.16 by its mandate (PAR) only defines protocol stacks in the
PHY and MAC layer, 802.16e defines mobility support for MAC and PHY
only
 Lack of network layer mobility completion

WiMAX Forum is supposed to cover network mobility, but…

WiMAX forum has weak experience in end-to-end protocol stack
development
 WiMAX is a pure industry ad-hoc group, like WiFi, which may not be the
appropriate place to deal with Network Mobility standards
 Integration with legacy network requires support from the carriers
APPLICATION
WiMAX Based Network
WiMAX MAC/PHY
page 15
3G Based Network
WiMAX/3G Dual MAC/PHY
BeyondSpot Proprietary
3G MAC/PHY
WiMAX Topic
Market & Time Competition


Market takes time!

Markets takes time to mature;
most new services will follow the
letter “N” curve as below
 Fixed WiMAX technology is far
from mass adoption, mobile
WiMAX would take even longer
Steady Growth
WiMAX has risks too!

Mobile WiMAX market is squeezed by
both 3G, Flash OFDM, and WiFi.
 802.11e, 11r, and 11n are enhancing QoS,
handover, and throughput.
 HSDPA (of 3G) shorten the gap with
WiMAX in throughput.
 Flash OFDM (by Flarion) has
demonstrated end-to-end solution.
WiMAX Marketing Guy
Disappointment
Rebuild Business Model
Marketing Hype
page 16
BeyondSpot Proprietary
WiMAX Topic
Global Spectrum Availability

Lack of Spectrum

most licensed spectrum for broadband are either for fix services or for 3G;
 hard to use license-exempt band to provide QoS guarantee mobile services
 WiMAX Forum is working on regulatory drawbacks, but progress is slow
2.4 - 2.485 GHz (WLAN, Indoor Only)
3.5GHz (WLL) License bands
5.4 - 5.725 GHz (RLAN, Europe)
2.5-2.6GHz MDS, MMDS License bands )
page 17
BeyondSpot Proprietary
5.725 - 5.825 GHz (U-NII) or
5.725-5.850 GHz (ISM)
5.25 - 5.35 GHz (U-NII,
Outdoor/Indoor)
WiMAX Topic
Back to Square One

Recent Trend in IEEE Standard Body

More members notice the challenge of WiMAX for 4G, and recognize the
value to demonstrate success of WiMAX first in Fix services, shown below.
 Progress in maintenance group is slow
 Worst case, WiMAX is back to square one (day one) as a pure fix standard!
page 18
BeyondSpot Proprietary
WiMAX Topic
BeyondSpot White Papers

BeyondSpot Offers White Papers for Selected Customers

Fixed wireless based WiMAX and QoS
 Please find me to exchange business cards
page 19
BeyondSpot Proprietary
WiMAX Topic
Conclusions

Most information on WiMAX
comes from press releases or the
campaign of WiMAX forum, not
balanced.

It is equally important to see
through the marketing smoke and
understand the real challenges.

We provide view points from both
ends;

Almost equal weight in YES and
NO to become 4G by (Mobile)
WiMAX.

Service providers should not
make investment decision
without knowing the risks;

But can not afford not to know
about WiMAX.

WiMAX is a worth
watching topic !
page 20
Opportunity of
WiMAX for 4G
Yes
BeyondSpot Proprietary
No
WiMAX Topic