4G Wireless Networks - AT&T Labs Research

4G Wireless Networks
Technology, Tele-Trends, and Tele-Prognosis
WWW2004 Emerging Applications for Wireless and Mobile Access (MobEA II)
R. R. Miller
Communications Technology Research
AT&T Labs - Shannon Laboratory
Florham Park, NJ
rrm@att.com
© AT&T 2004

Mobility Evolution – 1G
4G
3G
2.5G
2G
• Analog PHY
• Large Cells
• Incomplete Coverage
• Non-Uniform Quality
• Call Drops
© AT&T 2004

Mobility Evolution – 2G
4G
3G
2.5G
1G
• Digital PHY, Voice
• Mix of Large and Smaller Cells
• Nearly Ubiquitous Coverage
• Better Quality, but not Toll MOS
• Backward Compatible with 1G
© AT&T 2004

Mobility Evolution – 2.5G
4G
3G
2G
1G
• Digital PHY, Voice + Data
• Large, Smaller, and Microcells
• Ubiquitous Coverage + Capacity
• Slow Packet Data
• Backward Compatible with 1G, 2G
© AT&T 2004

Mobility Evolution – 3G
4G
2.5G
2G
1G
• Wideband Digital PHY
• Smaller Cells
• Packet + Circuit Operation
• Support of “Slow” Multimedia
• Backward Compatible to 2.5G
© AT&T 2004

Life Cycle Progression of Wireless Systems
Technology
Customer
Demands
Competition
Market
Size
Pre-Emergent Emergent Growth
Maturity Decline
Time
4G
Anticipated &
Emerging
Small Selective Base
of Early Adopters
Functionality
Substantial
3G
2G 1G
Critical decision point for 3rd
Generation Wireless standards
Technology
“Bandwagon”
Fragmented &
Knowledgeable
Flexibility and
Convenience
Shakeout in
Unstructured Market
Wide Usage &
Low-Cost
Sophisticated &
Entrenched
More for
Lower Price
Survival of the
Fittest
© AT&T 2004

Mobility Evolution – 4G
3G
2.5G
2G
1G
• Broadband Digital PHY
• Micro & Nanocellular
• “Viral” Coverage Model
• Wired-Like Multimedia Speed
• Computer Network Paradigm
© AT&T 2004

Techno-trends: Migration Drivers
Important Migration Drivers:
• Higher Capacity
• Better Communication Quality
• More Throughput / User
© AT&T 2004

Techno-trends: Info “Half-Life” & “Inconvenience Threshold”
© AT&T 2004

Techno-trends: Info “Half-Life” & “Inconvenience Threshold”
© AT&T 2004

Wireless System/Technology Evolution
© AT&T 2004

Blending Old and New Networks
User
Separate Voice and Packet
Networks
Switch/Router
& Transcoder
User
Voice
Network
Packet
Network
Circuit/Packet Network Unification
Switch/Router
& Transcoder
Broadband Network
User
Advanced
Network User
Access Transport
Core
Wireless
Metallic
Existing Network
Future Network
DISTRIBUTED
INTELLIGENCE
Circuit/Packet Gateway Interface
Coax
Fiber
Wireless
Metallic
Existing Network
Broadband Packet Network (Fiber)
Copper Pair
Wireless
Coax Copper Pair Wireless
Coax Copper Pair Wireless
Circuit Network
CENTRALIZED
INTELLIGENCE
© AT&T 2004
Core
Transport
Access
Premises

Moving IP Convergence into the Access Domain
DSL, Cable and Wireless Access frameworks will
migrate to full IP compatibility
Circuit-Switching
© AT&T 2004
Packet-
Switching,
QoS Controls,
and Virtual
Circuits

Expanding the Wireless Access “Pipe”
Narrow to Broadband Access Channels
Narrow Data/Voice-Rate Pipe
Wide All-Purpose Pipe
• More Bits
• Wider Channel Bandwidth
• Service Level Agreements
• Remote Quality
Monitoring
© AT&T 2004

Preventing “Road Kill” on the Broadband Wireless Highway
Impairments
DATA
Wireless Connectivity Equivalent to Wired
• Interference
• Noise
• Blocking
DATA
DATA
High-QoS
Capability
• Data In = Data Out
• Improved Error
Control
• Advanced QoS
Protocols
© AT&T 2004

“Flattening” the Wireless Network
Network
Distributed-Intelligence Wireless Networks
Circuit-based,
Centralized Control
Cellular Systems
MSC
Packet-based,
Distributed Control
4G WLAN Systems
© AT&T 2004

“Object-Oriented” Networking
Core
Network
“Instant Infrastructure” with Hybrid Wired-Wireless Networks
Transport
Network
Access
Network
Wireless at the “Last Link”
Net
Node
Net
Node
Net
Node
Net
Node
Net
Node
Net
Node
Flat, Mesh-Connected Network
with Arbitrary Wired/Wireless Links
© AT&T 2004

Direct Delivery and Location-Dependent Services
Info
Terminals
Don’t “Find-Me”, Instead “Know Where I Am”
Network
Answer? Answer? Answer?
1 2 3
User
Multiple Addresses, Multiple Terminals
Terminal
User
Registration,
GPS
Info
Network
Multiple Terminals, Single Address
© AT&T 2004

Lowering Broadband Access Modem Cost
Digital
Wideband
Radio
Modem
Digital
Wideband
DSL
Modem
Digital
Wideband
Cable
Modem
Wireless
Copper
Coax
Digital
Wideband
Radio
Modem
Digital
Wideband
DSL
Modem
Digital
Wideband
Cable
Modem
Separate Processing Techniques
for Various Access Media
Digital
Broadband
Modem
Low Cost “Universal”
Moore’s Law VLSI for
High Volume Multiple-
Application Use
Multi-Format Broadband
Modem “Engines”
© AT&T 2004
Digital
Broadband
Modem

Techno-trends: Broadband/Narrowband Service Fusion
Separate Service
Environments
Voiceband
Devices
Wired Access
Devices
Data
Devices
Cellular
Devices
Wireless Access
Devices
WLAN
Devices
Voice
Data
Ethernet/
DSL/Coax
Data
Voice
Voice Data
Data
Voice
Graphics
Image
3G Wireless
Image
Image
Video
Video
Universal
Broadband
Access
Networks
Multimedia
IP-Phones
Global Mobility
Universal Directories
PDAs
PalmTops Collaboration
Multisession Wireless IP Phones
Personal Agents
© AT&T 2004

Techno-trends: A/V, Computing, Communication Fusion
4G can deliver compelling
multimedia content to users
with inexpensive clients,
intelligent “edge” wireless
edge switches and small
cells, a better value
proposition for consumers
Effective Bandwidth
1G, 2G, 3G Service Suite
1 2
4 5
7 8
0
Rcl Sto Clr
Pwr VolEnd
Slow Packet
Data
Paging
Messaging

Source Coding Unification: IP Convergence “Glue”
Voice
Data
Signaling
Video
Common
Multimedia
Source Coding
Uniform over All
Networks
Multimedia
Unification
© AT&T 2004

Emergence of the “Flat” IP Packet-Based Environment
Education
Services
Entertainment
Television
Internet
Service
Providers
Broadband
Wireless
Access
Networks
Information Services
Information
Services
Application Service Providers
Application
Platform
Service
Platform
Transport
Network
Software
Distribution
Broadband
Wired
Access
Networks
Information Appliances
Interactive
Games
Network
Service
Providers
© AT&T 2004
4
Electronic
Shopping
FoodMart FoodMart

Techno-trends: Broadband-Induced Information Exchange Growth
Information Form
Video/
Image
HQ Speech/
Audio
H/S Data
Telephone/Fax
Entertainment
Industry
Financial/Retail/
Manufacturing
Industry
Electronics
Industry
Medical
Industry
4G Wireless
Computing
Industry
Library/Info
Service
Industry
Telecom
Industry
Generation Process Store Transport
Information Management Sector
© AT&T 2004

Background: The IEEE Standards Organization
802.3
CSMA/CD
Ethernet
1-100 Mbps
Sponsor
IEEE Standards Association
Standards Activities Board
Sponsor
Local and Metropolitan Area Networks
(LMSC, IEEE 802)
802.5
Token Passing
Ring
802.11
Wireless
WLAN
802.15
Wireless
Personal
Area Networks
IEEE 802.11:
• ~500 Voting Members
• 300+ supporting companies
• www.ieee802.org/11
Sponsor
802.16
Wireless
Broadband
Access
802.19
Co-existence
TAG
802.18
Radio
Regulatory
TAG
© AT&T 2004
802.20
MBWA

AT&T’s MAC Enhancement Vision Presented to 802.11 in 1999
Present 802.11 MAC
Enhanced 802.11 MAC
“Migrate 802.11 from an Ethernet Cord Substitute
to a Common Air Interface (like Cellular)”
© AT&T 2004

Background: Project 802.11
Enhanced
Security
Mechanisms
MAC QoS
Enhancements
MAC
PHY
2.4 GHz
Frequency Hopped
Spread Spectrum
1 Mbps
2 Mbps (optional)
I
E
5 GHz
High Throughput
Radio Resource
Measurements
Japan
Extensions
5 GHz
Spectrum Managed
2.4GHz
High Rate >20Mbps
2.4 GHz
Direct Sequence
Spread Spectrum
1 Mbps
2 Mbps
Published as IEEE Standard 1997
IEEE Std. 802.11-1997
Initial capabilities in White
N
K
J
H
G
Infra-Red
1 Mbps
2 Mbps (opt)
Wireless NetworkSG
Management
ESS Mesh
Wireless Access SG
Vehicular Environment
Fast Roaming
SG
Wireless Performance
Prediction
5 GHz
802.11a
6, 12, 24 Mbps
9-54 Mbps (opt)
International Standard 1999
ISO/IEC 8802-11: 1999
Completed additions in Green
S
R
A B
2.4 GHz
802.11b
5.5 Mbps
11 Mbps
Wireless Next
Generation
Publicity
Inter-Access Port
Protocol
Regulatory
Updates
SC
F
SC
Maintenance M
D
C
Reaffirmed 802.11 2003
Completed work in yellow
Active 2004 work in red
© AT&T 2004

Device Presence: Unlocking the Value of e-Media
* From Larry Brilliant’s (Vice-Chair, Cometa) Keynote at 2003 Supercomm
© AT&T 2004

Techno-trends: 4G Worldwide Spectrum Alignment
2.4 GHz
� 83.5MHz BW
� Usually Termed Industrial, Scientific & Medical (ISM)
� 3 DSSS/CCK Clear Channels
� Available almost worldwide; allocations being handled through
World Radio Congress (WRC)
� Most regulations support 802.11b, with some power and
indoor/outdoor usage caveats
5 GHz
� 300 MHz BW in U.S. (3 x 100)
� HiperLAN has harmonized with 802.11a, opening opportunity for
the first “world” WLAN access standard
� Increased band convergence anticipated at WRC-2003
� FCC seeking alignment of 255 MHz addl. for WLAN use (5-15-03)
Study
5000
1 Public consultation in progress
2 Exclusions in some countries
US/Canada (U-NII)
Japan 4 Study
Europe 2
US/Canada (ISM*)
Europe
Japan
Hong Kong
Australia
France 1
Spain
South America 2 , Caribbean 2
2400 2440 2480 2500
Study 3
5100 5200 5300 5400 5500 5600 5700 5800 5900
3 Per China MII #2001-653, #1998-178
4 National Frequency allocations are pending
(all by 2004)
China 4
U-NII
South America
Hong Kong
Australia
U-NII = Unlicensed - National Information Infrastructure (U.S. Terminology)
© AT&T 2004

Techno-trends: Moving from “Micro” to “Nano” Cells
Cell
Radius
(Feet)
1,000,000
100,000
10,000
1,000
100
MJ-MK
Mobile
Telephone
(~60 mi)
Maritime
Mobile
HF Radio
Service
(~300 mi)
Metroliner
Train
Telephone
(~15 mi)
1950 1960 1970
Year
Cell size reductions continue, driven by
availability of inexpensive distributed
computing and self-aggregating network
capabilities, resulting in full broadband
service with battery economy.
Advanced
Mobile Phone
Service (AMPS)
(~8 mi)
Cellular
MicroCells
(~2 mi)
PCS
Microcells
(~0.5 mi)
Cellular
Expanded
Service
(~4 mi)
The 3G
“Sweet
Spot”
WLAN
Nanocells
(~.06 mi)
1980 1990 2000 2010
100 Watts
10 Watts
1 Watt
100 mW
.01 mi 2
© AT&T 2004
30 mW
The 4G
“Sweet
Spot”
Mobile/
Portable
Maximum
Power
Output

A View of Small Cell/Large Cell Illumination
Path Loss, dB
40
60
80
100
120
140
160
Two-slope model, with steeper slope as propagation falls deeper into multipath environment
Typical Suburban
Environment
Slope transition breakpoint
moves in as base height is
reduced. (~500’ for 5m pole,
3200’ for 80’ tower)
180
0.01 0.1 1 10
Distance from Base, Km
Operation beyond transition point
requires disproportionately higher
power to overcome loss and to
sustain sufficient fade margin (QoS)
h = 5m Base Height
b
h = 25m Base Height
b
Median path loss, 5m
Median path loss, 25m
Client Antenna Height: 1.8m
Low base height mandated by aesthetic and siting concerns makes 1000’ cells a
“sweet spot” for coverage, transmit power, and link predictability/availability.
© AT&T 2004

Techno-trends: Capitalizing on Small-Cell Predictability
Path Loss, dB
40
60
80
100
120
140
160
180
0.01 0.1 1 10
Distance from Base, Km
Data set representing
measurements taken in
particular neighborhood
shown in overlay
h b = 5m Base Height
h b = 25m Base Height
Median path loss, 5m
Median path loss, 25m
Client Antenna Height: 1.8m
Takeaway: Small cells can be modeled with better accuracy
© AT&T 2004

A Perspective on 3G “Reach” vs. “Rate”
All things being equal, power will scale with channel bandwidth
PT = L90 -Gm -Gb -Isd + SNR0 + [ -174 dBm/Hz + NF + 10 log B ]
For a given distance, frequency and environment
PT - transmit power
L90 - maximum loss to achieve a given SNR0
Gm - mobile terminal antenna gain
Gb - base antenna gain
Isd - space diversity improvement
SNR0 - required signal to noise ratio
-174 dBm/Hz - thermal noise
NF - noise figure
10 log B - 10 x log of channel bandwidth (in Hz)
© AT&T 2004

Smaller Cells, Smaller Batteries
Rechargeable Battery Capacity Trends
Moore's Law
Device
Transmit Power
100 W
10 W
1 W
0.1 W
8-13
kbps
Impact of Current Rechargeable
Battery Capacity on Continuous
Transmission at Multimedia Rates
144
kbps
For multi-megabit rates, small
cell systems will remain a
more practical solution for
long battery life in portable
devices.
8-13
kbps
144
kbps
1.5
Mbps
Macrocellular Microcellular
Systems Systems
(~8 mi. cells) (~1/2 mi. cells)
11
Mbps
1.5
Mbps
144
8-13 kbps
kbps
Nanocellular
WLAN Systems
(300+ ft. cells)
© AT&T 2004
30 Sec
6 Min
1 Hr
10 Hr

Techno-trends: Centralized vs. Distributed Intelligence
Cellular
The availability of inexpensive computing platforms has allowed
intelligence to be pushed further toward the network edge...
802.11
…Resulting in networks with greater resiliency, faster
deployment and decreased labor to set up and maintain
© AT&T 2004

Techno-trends: “Coverage-First” Transitions to “Viral Growth”
2G/3G
Wide-Area
Macrocells
Microcells
Picocells
4G Self-Aggregating
Local Nanocellular
Networks
© AT&T 2004

Techno-trends: User Device/Service Expectations
• Wireless = Central Theme
• Telephone Handset + Radio
2G-2.5G
2.5G-3G
• Wireless = Part of Service “Bundle”
• Handset + 2-Way Pager + Internet
Browser + Data Bank + Media Player +
Remote Control + Geographic Locator +
Radio
3G-4G
• Voice = Part of the
Service “Bundle”:
VoIP Built-In
• Full Multimedia
Support and
Expanded User
Interface
• The “Anywhere,
Anytime
Appliance”
• Wireless Capability
is a “Given”
© AT&T 2004

Techno-trends: Traffic Management Evolution
ISDN
4G Wireless
Public WLAN
© AT&T 2004

Techno-trends: Service/Transmission System Maturation
UWB?
Wireless
“Generation”
1G
2G
2.5G
3G
4G
© AT&T 2004

Techno-trends: Deployment and Service Needs
F1
F1
F1
First-Generation Wireless LANs
• Peer/Peer and Client/Server
• Small User Population
• Isolated "Cells" and User Groups
• Non-Contiguous Coverage
• Indoor Operation
• Limited Mobility
• Mostly Asynchronous Traffic
• Slower than Ethernet
F1
F1
F1
Second-Generation Wireless LANs
• Data-Centric Internet/Intranet
• 10BT Ethernet-Compatible Speeds
• Multiple RF Band Interference Control
F2
Third-Generation Cellular
• Voice-Centric
• 1BT Equivalent
• Ubiquitous Coverage
• Sophisticated Resource Reuse
IEEE 802.11
Fourth-Generation
Wireless Communications
• Larger User Population
• 100BT Ethernet Speeds
• Full Roaming/Handoff Capability
• Contiguous Coverage in Dense Areas
• Wider Area Coverage
• Mobility (Follow-Me Service)
• Data, Voice, Multimedia
• Higher System Utilization/Reuse
• Enhanced Security
• Automatic Radio Resource Management
F1
F3
F2
F1
© AT&T 2004

Techno-trends: Increasing Reuse Dimensions
Spatial
Frequency /
Time
Reuse
1
2
3
2
1 1
2
3
1
2
3
2
3
1
2
3
1
2
3
1
2
3
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
QoS
1
1
2
3
1
2
QoS
2
QoS
3
Access Legacy
2
3
Time Domain
QOS-Based Protocol
1 = Freq 1
2 = Freq 2
3 = Freq 3
AP Time Interval 1
AP Time Interval 2
AP Time Interval 3
© AT&T 2004

Cognitive Radio and Automatic Resource Management
Automatic
Reciprocity
Measurements
G
F
B
A
E
C
Graph-Coloring Algorithm
D
H
-6
-6
-5
Channel/Time Assignment
Optimized for Minimum
Co-Channel Interference
Benefits:
• Reduced Installation Planning
• Improved Coverage
• Modular Capacity Additions
• Self-Healing Capability
F1
F6
F2
F3
F2
F4
F5
F1
© AT&T 2004

Techno-trends: “Smarter” Radios
Multi-Standard Access and Digital Radio Processing Technology
1 2 3
1 2 3
4 5 6
4 5 6
7 8 9
7 8 9
* 0 #
* 0 #
Rc l Sto Clr
Rc l Sto Clr
Pwr Vol End
Pwr Vol End
1 2 3
4 5 6
7 8 9
* 0 #
Rc l Sto Clr
Pwr Vol End
The Solution:
Front-End 1st IF 2nd IF Demodulator
Power Amp
Frequency Synthesizer
Buffer Amp
Modulator
Front-End 1st IF 2nd IF Demodulator
Power Amp
Frequency Synthesizer
Buffer Amp
Modulator
Front-End 1st IF 2nd IF Demodulator
Power Amp
Frequency Synthesizer
Buffer Amp
Modulator
Create Platforms for
Multi-Band, Multi-Mode
Devices and Radio
Ports by Utilizing
High-Performance DSP
Technology to Realize
"Software Radio"
1 2 3
4 5 6
7 8 9
* 0 #
Rc l Sto Clr
Pwr Vo l End
Channel
Processor
Channel
Processor
Channel
Processor
Broa dban d
Analog "Front-End"
Frf
uC
uC
uC
Voice
Process ing
Voice
Process ing
Voice
Process ing
2G
Radio
3G
Radio
4G
Radio
BB Front-End WB 1st IF A/D
BB Frequency Synthesizer
BB Power Am p
WB Buffer Amp
LO
Analog translation
to low I F
Fif
D/A
The Problem:
Multiple Standards
Threaten to Complicate
Spectrum Use and
Reinforce User
"Utility Belt" Device
Mentality
Digital IF Engine
Digital IF Engine
Digitization
at lower IF
Channel
Proces sor
RF Band
of Interest Digital EQ,
RAK E Engine
I
Q
DSP
Frequency
selection via
digital filterin g
Multimedia
Source
Coder
I
Q
DRP Radio
(e.g.TDMA,
WCDMA, WiFi)
Baseband
Information
DSP-based
extraction of
comp le x envelop e
components
© AT&T 2004

“Computing a Radio” with Precision RF Selectivity
© AT&T 2004

Techno-trends: A DRP “Motherboard” Example
An AT&T Labs 3-Carrier DRP Cellular Base Station
16”
© AT&T 2004

Techno-trends: Smarter Antennas and “MIMO”
Utilize independent information from multiple antenna elements to extract spatial information.
Track desired signal "signature" allowing independent antenna arrivals to be correlated
while interferers remain uncorrelated.
Can optimize signal-to-noise ratio for a specific signal spatially-separated from interferers
Digital Radio Processing to simplify extraction of multiple antenna images
Multiple-Input, Multiple-Output (MIMO)
Macrocell Systems
Microcell Systems
(In-Building / Campus)
Omni or Sector Antennas in
Large Cells or In-Building
Distributed Antennas
Benefits:
Capacity enhancement
More effective than diversity
Can be used to combat fading, interference
Particularly attractive for fixed/nomadic wireless application
Dynamically-switched packets
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Graph 1
Graph 1
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Adaptive
Null Steering/
Interference
Cancellation
Switched
Multi-
Sector
Graph 1
Rcvr
Graph 1
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Adaptive Array
Antennas: “Beams”
Replace “Cells”
Graph 1
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Graph 1
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Antenna Processor
Full Adaptive
Array with
Per-User
Optimized
Beams
Graph 1
EasyLink Enabled...
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Graph 1
EasyLink Enabled...
Dial> 201 555 3000
Dialing...
Connected...
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© AT&T 2004

Techno-trends: Improved Error Correction Coding
Input
Stream
Input
Stream
Standard
Coding
Space-Time
Coding
Space-Time
Coding
Simplified Space-Time (S-T) Coding Concept
Copy A
Copy B
Coded
Stream A
Coded
Stream B
Fading,
Interference
Fading,
Interference
Standard
Coding
Space-Time
Decoding
Space-Time
Decoding
Benefits:
• Inherent Transmit and Receive Diversity
• Coding Gains over Conventional Diversity Systems
• Can be extended to Frequency Diversity Applications
© AT&T 2004
Recovered
Stream
Recovered
Stream

Techno-trends: Media Access Control
© AT&T 2004

A Broadband QOS Protocol Example
Benefits:
An AT&T Labs Research-Developed QOS “Toolbox”
for Premises and Local Access Systems
Multimedia Service Support (Time-Bound, Streaming, Data, etc. with Dynamic Sharing)
Multi-Transport PHY Support (Simplex/Duplex and/or Long Propagation Delay PHYs)
Statistical Multiplexing Support (Priority Grant, Flow Control, Traffic Adaptation)
Characteristics:
Unblocked Reservation/Transmission for Real-Time Traffic (No Dropped/Delayed Packets)
Scheduling Algorithm for Reservation and Servicing (BW Efficiency and QOS Guarantees)
Combined Unblocked and Contention Reservation for Streaming/Bursty Traffic
Application to 802.11 Wireless LAN QOS Management
Uses Current 802.11 Distributed Coordination Function and Control Set
Establishes New Point Coordination Features (Resource Mgmt/Disciplined Superframes)
Supports Current PCF Operation, Adds Contention-Free and Managed Contention Modes
Responds to Performance-Based and Media-Oriented QOS Declarations
Compatible with Emerging AT&T Packet Network QOS Signaling Formats
© AT&T 2004

Downstream
(to STA/Client)
Upstream
(to AP/Base)
MediaPlex in Action - Reservation, Scheduling, and Polling
Superframe
D1
+
Poll
Ack
+
Poll
CC
CC
+
Ack
CF-
End
U1
+
Ack
VS13 VS31 VS28
RR RR RR RR
Dly-
B
Multi-
Poll
D1
B
Ack
S4
(No-
Ack)
RR
U2
Traffic Interval
Access Interval
Traffic
Interval
Supplementary
Access Interval
Unused
Access
Slot
PCF Managed Contention Period
• Disciplined Timing
• Separation of Access and Bearer (and Legacy)
• Controlled Contention Slotted Access
• TSPECs
• Polling/Reservations
• Time Interval Protection
© AT&T 2004
(E]DCF
CSMA
Period

Controlling Time Resource and QoS via HCF (polling example)
Applications
Provides
Provides
Traffic
Traffic
Specification
Specification
(TSPEC)
(TSPEC)
Response
Response
and
and
Management
Management
:
:
•
•
QoS
QoS
based
based
Queuing
Queuing
•
•
TXOP
TXOP
bound
bound
•
•
Throughput
Throughput
allocation
allocation
•
•
Rate
Rate
fallback
fallback
algorithm
algorithm
•
•
Stream
Stream
Session
Session
management
management
•
•
CC/RR
CC/RR
process
process
•
•
Radio
Radio
Resource
Resource
Management
Management
Individual Streams/TSPEC Limited by:
• total number of packets limits

MediaPlex Delivers - Actual System Measurements
Throughput (MBps)
6
5
4
3
2
1
0
mediaplex
FTP Tests
4.730
4.860
ad-hoc
4.456
4.352
GET
PUT
operation
ad-hoc
mediaplex
When compared to current DCF
(ad-hoc) operation, MediaPlex
provides QoS with high system
throughputs---even under
overload conditions---and does so
with low protocol overhead.
Throughput
(Mbps)
Throughput
(Mbps )
6
5
4
3
2
1
0
6.000
5.000
4.000
3.000
2.000
1.000
0.000
mediaplex
ad-hoc vs. mediaplex
up -
media
plex
ad -h oc
TCP Tests
5.703
5.431 4.743
ad-hoc
4.841
UDP Tests
uplink downlink
1472
64 1282565121024
down - ad -h oc
media
plex
FROM STA TO AP
Data Direction
FROM AP TO STA
Packet size
© AT&T 2004
ad-hoc
mediaplex
MediaPlex
Ad-hoc

Comparing MAC QoS Protocol Approaches
Active QoS
Streams
Superframe
Entering
Packet &
Client
Access
Queues
QoS
Coordination
Legacy Support
Channel Access
Admission Control
SLA Mgmt.
Resource Reuse
DCF (Current) EDCF/EDCA (TGe) HCF/HCCA (TGe) MediaPlex
H M L H M L H M L H M L
No QoS Prioritized QoS
Parameterized QoS
(Mandatory)
(Mandatory)
Distributed Distributed
Distributed + Point Point
N/A
Parameterized QoS
HCCA + Optional Features
Yes Yes In DCF/EDCF Interval
CSMA CSMA
CSMA + Polled Access Polling & Controlled Contention
None TSPEC Acceptance/Denial TSPEC w / Admission
Control
CSMA CSMA
Possible Resource Reuse
in CC interval
TSPEC w / Point Admission
Control as QoS Class
No SLA Mgmt. No SLA Management
Possible SLA Mgmt SLA Management
Synchronized Reuse
Intervals
© AT&T 2004

TGk: The First Step in Managing the Radio Resource
Migrating Current MIBs…
802.11
– Configuration for STA and very limited proprietary RF measurements
– Widely implemented in APs, but not standardized
– Very simple monitoring of global AP statistics (proprietary implementations only)
802.1x
– Detailed auth state for individual 1x ports
– Also some per port statistics
– Not widely implemented in access points today
Bridge MIB
– Possible to get some info on which STAs are associated with an AP
– Implemented in some APs
– Not 802.11 specific, little MAC, and no PHY statistics
To…
NETWORK
LINK/MAC
PHY
Standardized RF Measurements and Methods
• Basic measurements available to upper layers from AP and Client
- Neighbor lists for AP’s
- Client association to AP lists
- Noise histograms
- Accurate power level measurements in dBm referenced at the antenna
• Better diagnostics
- Obtaining information in a standard form from all equipment
• Enable better frequency planning and network optimization and performance
- Automated signal/interference surveys
• Enable new services
- Location awareness capabilities for AP’s and Clients
Radio Resource Management Study Group begun by AT&T in 2003
© AT&T 2004

Porting CelluLAN Fundamentals to 802.11 WNM Task Group
Migrating Present Mechanisms…
• Radio Resource Management via CSMA and backoff
• Disorganized Reuse
• No Coordination (except proprietary methods)
• Interference growing
• Channels likely to be too noisy for QoS
To…
Disciplined Radio Radio Resource Management
••Reuse Reuse via via space, space, time, time, frequency frequency
••AP’s AP’s syncronized syncronizedfrom from common common backbone backbone
••AP’s/Clients AP’s/Clients communicate communicate across across RF RF channel channel
••Discovery Discovery process, process, followed followed by by self-organizing
self-organizing
••Enable Enable Auto-configuration Auto-configuration Processes Processes
••Enable Enable Cognitive Cognitive Radio Radio interference interference avoidance avoidance
NETWORK
LINK/MAC
PHY
Radio Radio Resource Management Study Study Group Group begun begun by by AT&T, AT&T, final final
approval in in March, March, 2004 2004 (Task (Task Group Group Anticipated in in May, May, 2004) 2004)
© AT&T 2004

A Generalized Multimedia WLAN Enterprise Architecture
Data
Client
Telephony
Client
Video
Client
100BaseT
Radio Port
Interport
Networking
100 BaseT
Radio Port
Radio Port
Radio Port
100 BaseT
100 BaseT
LOCAL
ETHERNET
NETWORK
T1, FR,
ATM, OC-3,
etc.
TCP/
IP
SYSTEM SERVER
NATIONAL PACKET
NETWORK (FR, ATM, SONET)
Network
Administration
Mobility
Management
Operations &
Record-Keeping
© AT&T 2004
Authentication
& Security

Next-Generation Services and Human Interfaces
1900-1920 1930-60
No Controlled Audio Interface
Short-Range User/Terminal
Separation
Defining the “Multimedia Modal Distance”
1920-30
Individual Mouth/Ear
Interfaces Separated
from Terminal
300/500/2500-Set Era --
Handset Establishes Modal Distance
Dialing Interface at Terminal
1960-80
Trimline Era --
Dial/Audio
Interfaces
Combined
Cordless Era --
Entire Human
Interface Untethered
via Radio
1980-90
Multimedia Modal Distance
Audio/Video Info Content
Anthropomorphic Interfaces
Fusion of Communication
and Information Management
The Challenge for Personal Wireless IP Terminals:
Create a user environment as intuitive, comfortable
and easy to use as today’s voice telephony model
1990-99
PCS/Videophone Era --
Yesterday revisited...
Flip-Phone Only
Approximates Modal
Operation using
Miniaturized Handset
Video with No Modal
Distance Conventions
1 2 3
4 5 6
7 8 9
* 0 #
Rc l Sto Clr
Pwr Vol End
21 st Century
Communicators
© AT&T 2004

Wireless IP Device Service Enablers
Candidate Features for Next Generation Wireless IP Terminals
© AT&T 2004

An Example “Combination” Device in Desktop Use
An Experimental Multimedia Terminal: Desktop Mode
© AT&T 2004

Using the “Combination” Device as a Portable Handset
An Experimental Multimedia Wireless Terminal: Handheld Mode
© AT&T 2004

WVoIP – The “New” Telephony
Nomadic
Transportable
Handhelds and
Dual-Mode Cellular/WiFi
(1Q04)
Pocketables
Multimedia
Infopads
Wearables
WiFi phones are becoming available now
• “Cellular” and “cordless” form factors
• Dual-mode cellular/WiFi phones announced (Motorola, Nokia..)
• Applications becoming available for PDAs
• Talk/listen time comparable to existing handsets
Improvements Underway at AT&T Labs - Research
• Carrier-Grade QoS
• Better Radio Channel Processing – New VLSI
• SIP VoIP protocol additions
• New services
Takeaway: WVoIP is being fueled currently by businesses
converting to broadband multimedia networks
© AT&T 2004

WiFi (In) Security
Who thinks it’s important now:
Enterprise premises WLANs
Businesses using teleworking/telecommuting, ROBOs and SOHOs
Government markets
Why it will become more important:
Increasing use of networked WiFi service will breed more hacking
Introduction of telephony, image and video content will increase public sensitivity
Increasing use of “hot spots” by corporate employees
Digital rights management and identity/location/data security
Three security schemes are available:
802.11 Wired Equivalent Privacy (usually paired with MAC address authentication)
Intended for privacy, not security
Part of original 802.11, based on RC4 encryption algorithm (used in packet cable)
Encrypts airlink to AP only
Protects user packets, not complete airlink
Requires user to know WEP key to associate (usually same key used for all network APs)
Already compromised – weak key management, but encryption algorithm still effective
802.11 TGi Security MAC Task Group
Interlocks with WiFi Protected Access (next page)
WEP RC4 with improved key administration and path to stronger encryption
Sets up airlink security to each AP, not whole network
Still no encryption of control frames (possible system vulnerability)
Complicates handoffs, since new link cannot use same key (transfer delay)
IPSEC
Encrypts user session over entire network end-to-end
Handles multiple tunnels simultaneously (needed for telephony control/speech)
Encapsulation allows handoffs without renegotiation
Allows “open” radio access network (don’t need keys to associate)
Requires device software “shim” or hardware in clients
© AT&T 2004

A Security Migration Plan
802.1x
802.11 TGi
Other Features
BSS
IBSS
Pre-authentication
Key hierarchy
Key management
Cipher & Authentication Negotiation
Data Privacy Protocols
TKIP*
CCMP +
* Temporal Key Integrity Protocol (TKIP) provides minimal level of data privacy for
pre-RSN hardware conforming to the 1999 issue of 802.11
+ Counter with Cipher Block Chaining Message Authentication Code Protocol
(CCMP), an AES-based protocol, provides robust data privacy. Any
implementation claiming to provide security shall implement CCMP
Wi-Fi Alliance WPA
(Wi-Fi Protected Access)
• Implement what is stable and
bring it to market
• Continue to upgrade to 802.11i
© AT&T 2004
Full 802.11i Standard Adherence

Secure WiFi Roaming – What’s the Problem?
• Fundamental difficulty: WiFi is a Local Area Network
– Compare with GSM cellphone (a single, precisely defined
Common Air Interface standard), where secure roaming was
built into original design.
– WiFi is not a CAI, only a substitute for Ethernet cord
– WiFi service solutions evolving as wide-area applications are
recognized
• Heterogeneous environment
– Employee’s premises vs. residential vs. other business vs.
public
– Overlapping service providers
– Free vs. for-pay
• Complex configuration profiles
– Network configuration: Fixed/DHCP
– Access authentication: 802.1x vs. Web vs. open
– Security settings: WEP on/off
– Multiple authentication steps
• Handoff between dissimilar systems; re-configuration
© AT&T 2004

Techno-trends: Security Moves Up the “Stack”
Application
Presentation
Session
Transport
Network
Data Link
Physical
Security Gate Example Hacker
PGP
Secure Shell Web Browser
IPSEC
IP Authentication
WEP
MAC Address Verification
Hop, Chip, and Jump
(Frequency, Modulation, Small Cells)
Info
Thieves
Virus
Breeders
Encryption
Specialists
Identity
Spoofers
Privacy
Busters
Access
Crackers
Sophisticated
Hardware Hackers
© AT&T 2004

“Hot Spots” and VPNs as a Wide-Area Roaming Substitute
Enterprise Semi-Public Public
Home
802.11√ 802.11 √ 802.11 √ 802.11√
Ethernet? Cellular? Cellular? Bluetooth?
Cellular? Payphone? Payphone? Powerline?
BB Kiosk? HPNA?
Ethernet?
VPN
VPN
VPN
VPN
VPN
© AT&T 2004

802.11 Reaches for Space
Command and Control of Space Assets Through Internet-Based Technologies Demonstrated
The NASA Glenn Research Center successfully demonstrated a transmission-control-protocol/ Internet-protocol- (TCP/IP) based approach
to the command and control of on-orbit assets over a secure network. This is a significant accomplishment because future NASA missions
will benefit by using Internet-standards-based protocols. Benefits of this Internet-based space command and control system architecture
include reduced mission costs and increased mission efficiency. The demonstration proved that this communications architecture is viable
for future NASA missions.
This demonstration was a significant feat involving multiple NASA organizations and industry. Phillip Paulsen, from Glenn's Project
Development and Integration Office, served as the overall project lead, and David Foltz, from Glenn's Satellite Networks and
Architectures Branch, provided the hybrid networking support for the required Internet connections. The goal was to build a network that
would emulate a connection between a space experiment on the International Space Station and a researcher accessing the experiment
from anywhere on the Internet, as shown in the figure.
The experiment was interfaced to a wireless
802.11 network inside the demonstration area.
The wireless link provided connectivity to the
Tracking and Data Relay Satellite System
(TDRSS) Internet Link Terminal (TILT) satellite
uplink terminal located 300 ft away in a parking
lot on top of a panel van. TILT provided a crucial
link in this demonstration. Leslie Ambrose, NASA
Goddard Space Flight Center, provided the
TILT/TDRSS support. The TILT unit transmitted the
signal to TDRS 6 and was received at the White Sands
Second TDRSS Ground Station. This station provided
the gateway to the Internet. Coordination also took
place at the White Sands station to install a Veridian
Firewall and automated security incident measurement
(ASIM) system to the Second TDRSS Ground Station
Internet gateway. The firewall provides a trusted
network for the simulated space experiment.
© AT&T 2004

The Current Fragmented Home Termination Model
Broadband
Narrowband
MODEM MODEM
-----------CABLES-------------
AV Net
PC Net
Phone Net
Home
Control
Net
-----------CABLES-------------
TV
VCR
Audio System
STB
Camcorder...
PC
Printer
Scanner...
Phone
Fax...
Environmental
Security
Medical
Domestic app…
© AT&T 2004

The Networked Home: The Premises Premises
• Broadband communication
services are made more valuable
if users can easily access them
• People who want broadband
connectivity want the service,
but not disruption of their homes
to get it
• Installation of home networks
can be a labor-intensive and
costly endeavor for service
providers and homeowners alike
© AT&T 2004

Home Gateway Termination Model
Wireless
Broadband
Narrowband
GATEWAY
IP Home QoS Networks
Legacy
Eqpt.
2005+ Vision
Entertainment
Productivity
Utility
Wireless
TV
VCR
Audio System
Remote Control
Camcorder...
PC
Printer
Scanner...
Phone
Fax
Environmental
Security
Medical
Domestic apps…
© AT&T 2004
Wireless
Audio
Video
Telematics
Vehicle
Monitoring
Etc…

Bringing Broadband Home: The Wireless IP Network Delivery Trial
Voice
Client
802.11
Data
Client
802.11
Video
Client
802.11
House 1
Cable
Modem
Access
Port
802.11
MediaPlex QoS
Customer
Premises
Houses 2-25
Cable
Network
Block
Converter CMTS
Voice Trunk
Gateway
PSTN
Cable Head End
Layer 2
Switch
Router
Internet
AT&T
Firewall
AT&T
Intranet
Call
Agent
Services
Platform
FP Network Lab
Server/
Database
Router
© AT&T 2004

Broadband 4G for The Campus and “The Burbs”: A Vision
Broadband
Backhaul
© AT&T 2004

Field of Use for Next-Generation Systems
Megabits per Second
Peak
Data
Rate
100
10
1
.1
Bluetooth
Higher Rate,
Less Mobility
Zigbee
PANs
2.4GHz
Zigbee (US)
Zigbee (Europe)
4G H/S Wireless LAN
5 GHz Unlicensed
4G Wireless LAN
2.4 GHz Unlicensed
3G Fixed or Pedestrian
3G Mobile
2.5G Mobile/Pedestrian
“The Right Tool
for the Right Job”
3G/802.16 Wireless
Various Bands
10 feet 100 feet 1 mile 10 miles
Wider Area,
More Mobility
2G Wireless
800 MHz, 2 GHz
© AT&T 2004
Range

A New Concept: Multi-Tier Diffuse-Field Wireless Networks
Backbone
MAN
Local
Prem
Metro Fiber (DS3)
H/S Metallic (VDSL,PON)
L/S Metallic (DSL,100BT)
Metallic (T/R, 10BT)
Cord (RS-232)
Core Fiber
``
``
``
``
802.16 PTMP
802.11 PTMP
802.11 WLAN
802.15/Zigbee
RFID
Backbone
WMANs
WLANs
WPANs
Wireless Now Supports Multi-Tier Architectures Like Wired Networks
– More Throughput, Higher Quality, Lower Cost, Edge Intelligence, QoS
– Each Layer Demultiplexes Throughput from Layer Above
– “Network of Networks” Approach, Like Internet
– “Mix and Match” Architectural Elements
– TCP/IP “Glue” Protocol Convergence Layer, Software Defined Interfaces
© AT&T 2004

Wrap Up…And Thanks!