1. 802.11 Wireless Local Area Networks Bruce Kraemer Chair 802.11 V03
IEEE
802.11
Wireless Local Area Networks
Bruce Kraemer
Chair
V03

2. 3/27/2017
Disclaimer…
“At lectures, symposia, seminars, or educational courses, an individual presenting information on IEEE standards shall make it clear that his or her views should be considered the personal views of that individual rather than the formal position, explanation, or interpretation of the IEEE.”
IEEE-SA Standards Board Operation Manual (subclause 5.9.3) 2
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3. Introduction and Agenda
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Introduction and Agenda
Presentation
Context
History
Market
Science Challenges
Standard Baseline
Extensions
Further Information
Amendment Project details
References 3
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4. Context

5. Standards Activities Board Local and Metropolitan Area Networks
IEEE 802 Organization
Standards Activities Board
IEEE Standards Association
802.3
CSMA/CD
Ethernet
802.5
Token
Passing
Ring
802.11
Wireless
WLAN
802.15
Personal
Area
Networks
802.20
Mobile
Broadband
Access
802.19
Co-existence
TAG
Sponsor
IEEE 802
Local and Metropolitan Area Networks
(LMSC)
802.17
Resilient
Packet
802.18
Radio
Regulatory
802.16
802.21
Media
Independent
Handoff
802.1
Higher
Layer
LAN
Protocols
802.22
Regional
IEEE : ~500 Participants
Voting Members ~300

6. History

7. Activity History 1997: IEEE 802.11 standard approved (2.4GHz – 1Mbps)
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Activity History
Feb 14, 1876: Bell files telephone patent
June 1897: Marconi work- “Signaling through Space without Wires”
1970: ALOHAnet operational (Abramson, 9600 baud)
1976: Metcalf & Boggs: “Ethernet: Distributed Packet-Switching for Local Computer Networks”
1980: Project 802 formed (1 Mbps initially, revised to 20 Mbps 1982) (Feb 1980 , 125+ attendees)
1980: Ethernet Bluebook published (September , Digital. Intel, Xerox)
1981: FCC issues NOI for unlicensed spectrum
1983: First version of Base5 spec completed
1985: FCC opens ISM Band- spread spectrum allowed
1985: First version of published (10 Mbps)
1987: Project 802.4L – Wireless Token Bus begins
1989: ISM frequency Bands 900MHz, 2.4GHz and 5GHz allowed
1990: IEEE 802 drops 802.4L starts project
1990: BASE-T (802.3i) released
1997: IEEE standard approved (2.4GHz – 1Mbps)
1999: Apple IBook introduced with integrated (AirPort) 7
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8. Activity History 1994: 1st wireless radios - Inventory control
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Activity History
1994: 1st wireless radios - Inventory control
1997: IEEE standard approved (2.4GHz – 1Mbps)
1998: UNII (Unlicensed National Information Infrastructure) Band - 5 GHz
1999: IEEE standard achieved ISO/IEC approval
1999: IEEE a (5GHz – 54Mbps) - approved IEEE b (2.4GHz- 11Mbps)- approved
1999: Formation of WECA (now Wi-Fi Alliance)
2001: IEEE d Regulatory Domains - approved
2003: IEEE g (Higher rate 2.4GHz PHY) – approved IEEE i (Security) - approved IEEE h (Spectrum Mgmt) - approved IEEE f (interaccess point protocol) – approved
2005: IEEE e (MAC enhancements – QoS) – approved 8
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9. Market Acceptance

10. Market Size and Trends Market segment diversity continues to increase
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Market Size and Trends
Market segment diversity continues to increase
1 million
Units
per day 10
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11. Wi-Fi Hotspot Public Access
280K+ hot spots in 132 countries
Source: JiWire (2009)
1.2 Billion connects
Source: In-Stat
87% of US hotels offer Wi-Fi
Source: American Hotel & Lodging Assn

12. Expanding Uses - Airline Examples
American Airlines
Lufthansa
Virgin America
Google
Aircell GoGo Inflight Internet
Smart Grid 12
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13. Science Challenge

14. Air is a Poor Substitute for Wire or Fiber
Large Scale fading
Attenuation (distance, obstructions)
Delay
Small scale fading
Multipath (Reflections)
Doppler
Frequency selective fading
Shared
Regulatory considerations
Interference 14
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15. Wireless Constraints Shannon-Hartley Friis path loss
BW= channel bandwidth (Hz)
S = Signal
N = Noise
watts (not dB)
C= channel capacity (bits/sec)
C = BW x log2 1+S N
Friis path loss
GtxGrx c2 1
Prx = x
Ptx
(4pd)2 fc2
s Nf

16. Standard Baseline

17. Basic Service Protocol - Listen Before Talk 1Mbps example
1500 Byte User DATA
PPDU
1500 Byte User DATA
PPDU
12192 ms
12192 ms
DIFS
(listen)
DIFS
(listen)
50 ms
50 ms
SIFS
ACK
PPDU
SIFS
ACK
PPDU
10 ms
304 ms
10 ms
304 ms

18. The 802 LAN Architecture (Higher Layers) (Higher Layers) LLC LLC MAC
OSI reference model
End station
End station 7 6 5 4 3 2 1
Application
(Higher
Layers)
(Higher
Layers)
Presentation
Session
LLC sublayer
Transport
MAC Bridge
Network
MAC service
user
Link
LLC
LLC
MAC
MAC
RELAY
MAC
MAC
MAC service provider
MAC sublayer
Physical
Phy
Phy
Phy
Phy
Physical layer
LAN
LAN
Medium

19. Project Scope (cont.)

20. Standard Extensions

21. Technology Solutions PHY Multiple Antennas Forward Error coding
Modulation
Media access
MAC
Quality of Service
Network measurement & Management
Security 21
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22. Summary of Major PHY Projects
A - 20 MHz BW, 5GHz
B - 20 MHz BW, 2.4 GHz
G - 20 & 40 MHz BW, 2.4 GHz
N - 20 & 40 MHz BW, 2.4 & 5GHz
AC – 20 to 160 MHz BW, 5GHz
AD – 2 GHz BW, 60 GHz
AF – TV White Space Spectrum
AH – Unlicensed spectrum below 1 Gz

23. PHY Project Sequence 100 Gbps 10 year yardstick 10 Gbps ad ac 1 Gbps
802.3
milestones n
100 Mbps a g
10 Mbps b
802.11
milestones
Original
1 Mbps
100 Kbps 80 85 90 95 00 05 10 15

24. IEEE 802.11 – Key Technical Attributes
Specifications for the Physical and MAC Layers
Backward compatibility with legacy standard
Maximize spectral efficiency and performance
Co-existence with other device sharing the 2.4GHz and 5Ghz frequency bands
Physical layer
Data Rates – Mbps 24
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25. Standard Revision Process
528 pages
Amendments a b d e g h i j
1220 pages

26. Standard Revision Process - underway
1220 pages
Amendments
k (223 p)
n (560 p) D11.0
p ( 45 p) D11.0
r (116 p)
y ( 84 p) D11.0
w (114 p) D10.0
v (428 p) D16.0
revision
D pages

27. Standard Revision Process - underway
D pages
Amendments
u (218 p) D13.0
s (361 p) D9.0
~3000 pages

28. Standard Revision Process
~3000 pages
Amendments
aa (126 p) D3.0
ac (193 p) D0.1
ad (406 p) D1.1
ae ( 49 p) D2.0
af ( 159 p) D1.0
ah ( ??? p) D1.0
ai ( ??? p) D1.0
Publication ~ 4000

29. 802.11 Architecture Overview
Multiple Over the Air PHY options
One common MAC a b g n ac ad af ah
MAC

30. Unlicensed Frequency Bands
<700 MHz
900 MHz
2.4 GHz
5 Ghz
60 GHz

31. Spectrum for current PHY Amendments
6 GHz
802.11 b a g n j y
5 GHz
4 GHz
3 GHz
2 GHz
1997
1999
2001
2003
2005
2007
2009
Calendar Time

32. Spectrum – Forward Looking
100 GHz
802.11 b a g n j y ad xx
10 GHz
1 GHz
.1 GHz
1997
1999
2001
2003
2005
2007
2009
2011
2013

33. Overview of Project Objectives
PHY (.11, a, b, g, j, n, ac, ad)
Change data rate options
Change spectrum
Project examples (.11, a, b, g, j, n, y, ac, ad, af, S1G)
MAC
Security (i, w)
Measurement and Management (k, v)
Flow control and QoS (e, aa, ae)
Time required to establish connection (p, r, FIA)
Spectral Efficiency
Regulatory behavior (d, h)
Radio node connection topology (s, z)
Connection with other networks (u)

34. Summary of Major MAC Projects
D – Country information
E - QoS
F – Inter AP communication
H – DFS,TPC Spectrum sharing with radars in 5GHz
J – Japan 4.9 GHz
K – Radio Measurement
P – Vehicular Environments
R – Fast roaming
S – MESH Networking
U – Inter-Networking
V – Network Management
W – Secure Management Frames
Z – Tunneled Direct Link
AA – Video Transport
AE – QoS for Management Frames
AI – Fast Initial Link Setup

35. IEEE 802.11 Standards Pipeline
802.11z
TDLS
802.11s
Mesh
MAC
802.11r
Fast Roam e
QoS
802.11u
WIEN
802.11k
RRM h
DFS & TPC
802.11aa
Video Transport
802.11V
Network
Management
802.11Y
Contention
Based
Protocol
802.11ai
FILS i
Security
Smart Grid f
Inter AP
802.11ae
QoS Mgmt Frm
802.11p
WAVE
802.11mb
Revision ah
a 54 Mbps
5GHz
802.11n
High
Throughput
(>100 Mbps)
802.11af
TVWS g
54 Mbps
2.4GHz
802.11ac
VHT 5GHz
802.11W
Management
Frame
Security
PHY
802.11ad
VHT 60GHz
802.11b (’99)
11 Mbps
2.4GHz
Published
Amendment
Discussion Topics
Study
groups
TG without draft WG
Letter Ballot
Sponsor
Ballot
Published
Standard

36. Further Information

37. Further Details Follow
802.11z
TDLS
802.11s
Mesh
MAC
802.11r
Fast Roam e
QoS
802.11u
WIEN
802.11k
RRM h
DFS & TPC
802.11aa
Video Transport
802.11V
Network
Management
802.11Y
Contention
Based
Protocol
802.11ai
FILS i
Security
Smart Grid f
Inter AP
802.11ae
QoS Mgmt Frm
802.11p
WAVE
802.11mb
Revision ah
a 54 Mbps
5GHz
802.11n
High
Throughput
(>100 Mbps)
802.11af
TVWS g
54 Mbps
2.4GHz
802.11ac
VHT 5GHz
802.11W
Management
Frame
Security
PHY
802.11ad
VHT 60GHz
802.11b (’99)
11 Mbps
2.4GHz
Published
Amendment
Discussion Topics
Study
groups
TG without draft WG
Letter Ballot
Sponsor
Ballot
Published
Standard

38. 802.11n - High Throughput Overall project goals Much higher data rates
20 & 40 MHz channelization
1 to 4 spatial streams
1 stream for Client (Mandatory)
2 stream for Access Point (Mandatory)
½ Guard Interval
56 tones (in 20MHz)
5/6 coding
Green Field preamble
Block aggregation
Maximum PHY throughput of 600Mbps
Better Range
Beam Steering
Status: Published 2009

39. TGn Throughput

40. 802.11n - 20MHz Channel Mask New 20MHz spectral mask
Same as IEEE a Mask
Modified signal floor at 30MHz
From -40dBr to -45dBr

41. 802.11P Wireless Access in Vehicular Environments (WAVE)
Defines enhancements to support data exchange between high-speed vehicles and between these vehicles and the roadside infrastructure in the licensed ITS band of 5.9 GHz.
Applications planned within the ITS domain (ITS services), including:
collision avoidance
traveller information
toll collection
commercial vehicle operations
transit operations
traffic management
connecting the vehicle to the Internet.
Status: Published 2010

42. 802.11s MESH
An amendment to create a Wireless Distribution System with automatic topology learning and dynamic wireless path configuration.
Target number of packet forwarding nodes: ~32
Support unicast and broadcast/multicast traffic
Use i security or an extension thereof
Extensible routing to allow for alternative forwarding path selection metrics and/or protocols
Use the four-address frame format or an extension
Interface with higher layers and connect with other networks using higher layer protocols
Status: Produced draft 4.0 – preparing to go to Sponsor Ballot
Publication expected fall 2011

43. Classic 802.11 Wireless LAN Wired InfrastructureAP AP AP
STA
BSS = Basic Service Set
STA
STA AP
STA
STA
STA
STA
STA
ESS = Extended Service Set ≈ SSID
= radio link
Wireless Paradox: WLAN Access Points are Typically Wired

44. Unwire the WLAN with Mesh
Wired Infrastructure
Mesh AP
Mesh AP
Mesh
Point
Mesh AP
STA
STA
STA
Mesh AP
STA
STA
STA
STA
STA
ESS = Extended Service Set ≈ SSID
= mesh radio link

46. Tgu – Wireless Interworking
Background
As IEEE hotspot deployment has become more widespread throughout the world, several problem areas have emerged with the way in which the hotspot behaves regarding its connection to external networks (e.g. the internet, cellular networks) which could be solved by standardization.
As the diversity of hotspots have proliferated, users have started to become frustrated with the non uniformity of interworking systems (e.g. poor service definition, disparate registration procedures, non-ubiquitous roaming).
Within the IEEE community it was felt that an amendment to the IEEE standard would be in order to address these problem areas. Generically these issues have been referred to as interworking, which refers to the functionality and interface between an IEEE access network and any external network.

47. Tgu – Wireless Interworking
Objectives
The primary objective of IEEE u, is to create an amendment to address interworking issues between an IEEE access network and any external network to which it is connected.
Interworking, is actually a collection of different functionalities:
Online Enrolment
Network Selection
Security
Authorization from Subscriber Network
Media Independent Handover Support
Status: Last Draft balloted was D 13.0 – Published 2011

48. 802.11V Network Management
Explosive growth of wireless LANs emphasized the need to
Maintain network quality and security
Manage the RF environment
largely driven by interference from neighbouring wireless networks
Secure the network to maintain privacy and prevent unauthorized use.
Optimize the Network
improve the ability to shape the network
Status: Last Draft balloted was D 16.0 – Published Feb 2011

49. TGv Content – Increased Station Power Saving
Traffic Filtering Service
Enables the AP to filter traffic for the station, and deliver only frames of a specified type.
WNM-Sleep Mode
Provides an additional, extended power save mode.
When used with the Traffic Filtering Service, can provide significant station power savings, and provide a “Wake on WLAN” service.
Flexible Broadcast/Multicast service
Enables multicast frames to be sent at longer delivery intervals and higher data rates, improving performance of multicast applications, and reducing station “awake time”
Proxy ARP
Enables stations to remain in power save mode longer
TIM Broadcast – Enables stations to check for queued traffic without receiving a full Beacon frame.

50. Example TGv Based Applications
“Wake on WLAN” Service– Stations sleep and are “awakened” when specific frames are received
Example application: User leaves corporate desktop in “sleep mode”, goes home, uses VPN from home to corporate LAN, wakes up and uses desktop remotely
Reduces power consumption of end devices, even stationary ones
Improved client power saving
Proxy ARP, TIM Broadcast, FBMS, Sleep Mode, Traffic Filtering
“Wireless Speakers” – Use Location services timing measurements to support audio synchronization
Improved Multicast Performance
Network Diagnostic Analysis/Troubleshooting
Co-located Interference Reporting, Diagnostic Reporting, Event Reporting, Multicast Diagnostics Reporting

51. 802.11w – Protected Management Frames
One of the frame types defined in is “Action” sub-type “Management”
Management frames were previously less well protected than data frames.
The objective of this was to improve the security by providing data confidentiality of action management frames, deauthentication and disassociation frames
This standard protects networks from attack by malicious systems that forge disassociation requests that appear to be sent by valid equipment
Status: Last Draft balloted was D 10.0 – Published 2009

52. 802.11z Tunneled Direct Link
The purposes of this amendment are to create a new DLS mechanism which:
a) Does not require access point upgrades (i.e. supports DLS operation with the non-DLS capable access points),
b) Which supports power save mode (when associated with either DLS or non-DLS capable access points), and
c) Continues to allow operation of DLS in the presence of existing DLS capable access points
Status: Last Draft balloted was D 13.0 – Published 2010

53. P802.11z example
Access Point maintains control over network connection air times
However, device pairs can optimize their conversation and use modes not supported by the access point

54. 802.11 AA Video Transport Stream
Provides a set of enhancements to MAC to significantly improve video streaming performance while maintaining data and voice performance by improving Multicast/Broadcast video streams for link reliability with low delay and jitter.
Enhancements to the MAC for robust video streaming offer:
Interworking with relevant mechanisms including, but not limited to, 802.1Qat, 802.1Qav and 802.1AS
Graceful degradation of video streams when there is insufficient channel capacity.
Increasing robustness in overlapping BSS environments, without the requirement for a centralised management entity.
Modifying EDCA timing and parameter selection for video transport
Status: Just completed WG balloting of draft 3.0 – preparing to go to Sponsor Ballot

55. 802.11AC Very High Throughput <6GHz
Goal: A multi-user BSS peak aggregated throughput of at least 1Gbps as measured at the MAC data service access point (SAP)
Robust and flexible bandwidth management: native support for simultaneous multiple bandwidth operation (within a given frequency band)
Add optional outdoor compatible delay spread resistance
Below 6GHz carrier frequency operation excluding 2.4GHz operation and ensuring backward compatibility with legacy IEEE802.11a/n devices in the 5GHz unlicensed band.
Status: 0.1 draft out for review – planning to begin balloting on D1.0 in March 2011

56. 802.11AD Very High Throughput
60 GHz PHY
2GHz channel bandwidth, 4Gbps data rates
Market drivers for Very High Throughput wireless LAN, include:
Never ending quest for higher performance computing drives higher processing power.
Media appliances are moving to HD content, driving 10X storage capacity and bandwidth requirements.
Mainstream Wired LAN products have shifted to Gigabit per second speeds. The trend for a purely wireless campus drives the need for wired equivalent multi-Gigabit per second wireless solutions.
Aggregate capacity increase using reduced cell sizes.
Status: Completed preparation of draft 1.0 – balloted in WG October Preparing comment resolutions for next draft revision and ballot.

57. 802.11ae QoS for Management Frames
This project will consider the classification and prioritization of management frames
All IEEE MAC management frames are transmitted at the highest priority.
Previous amendments ‘k’, ‘y’, ‘w’, ‘v’, and ‘u’ have introduced features that rely on management frames, which are essential for network operation.
In some cases, the management traffic will contend with network data traffic and reduce the performance of certain WLAN applications.
Providing a mechanism to prioritize management frames will enable improved performance of IEEE networks
This project will consider management frames that are used in both pre- and post- association.
Management frames of subtype Action will be considered. Other management frame types may be considered.
Status: Just completed ballot on 2nd draft.

58. 802.11af - Operation in the TV White Spaces
This project will make the necessary MAC and PHY changes to enable products to take advantage of this additional spectrum available due to the global transition to Digital TV (DTV) and lightly used sub-Gigahertz RF spectrum now becoming available, much of it for unlicensed, license exempt and/or lightly licensed use.
Example, On November 4, 2008, the United States FCC approved Report & Order , allowing unlicensed use of TV band spectrum, in accordance with Part 15. Subpart H of FCC rules. Ofcom (UK) is in the process of making this Digital Dividend band available, and the EU has conducted a consultation on the band. Other regulatory domains are expected to follow.
Status: Produced draft 1.0 – just completed first ballot in February 2011

59. TGah – Sub 1 GHz Project proposes to use spectrum below 1 GHz.
Lower frequency will increase range
Channel bandwidths have typically been 20 MHz or more, lower channel bandwidth will be required.
Status: New Task group November 2011– working on Use Cases and will begin to develop first draft

60. TG ai (FILS)
Fast Initial Link Setup goal is to reduce initial association time to allow fast connection and data transfer in situations where users are very dense and highly mobile.
Goal definition:
Build a secure, fast initial authentication that
a) is suitable for users experiencing a small dwell time in a cell (due to high mobility or small cell sizes users)
b) scales for large number of simultaneously occurring initial authentications
Status: New Task Group January 2011– describing Use Cases – will begin to develop first draft

61. Future Projects Security Low power consumption Higher speed
Longer range
Spectral efficiency
QoS
Spectrum Sharing/ Cognitive Radio/ SDR
Beamforming/ Smart Antennas

62. References

63. Publication Examples IEEE Wireless Communications IEEE Network
IEEE Communications Magazine
IEEE Transactions on Wireless Communications
IEEE Spectrum
Proceedings of the IEEE
IEEE Transactions on Mobile Computing

64. Recently Published Papers re 802.11
Selfishness in Mesh Networks
MAC Layer Misbehavior in Wireless Networks: Challenges and Solutions
Designing VoIP Session Management over Interworked WLAN-3G Networks
The need for Access Point Power Saving in Solar Powered WLAN MESH Networks
Interworking of WLAN-UMTS Networks
A Scalable Monitoring System for Wireless Networks
Toward Dependable Networking: Secure Location and Privacy at the Link Layer
Handover Management in Integrated WLAN and Mobile WiMAX Networks
Minimum Interference Channel Assignment in Multiradio Mesh Networks
An Equal-Spacing-Based Design for QoS Guarantee in e HCCA Wireless Networks
New MAC Scheme Supporting Voice/Data Traffic in Wireless Ad Hoc Networks
Improving Security of Real-Time Wireless Networks Through Packet Scheduling
A Cross-Layer Approach for Per-Station Fairness in TCP over WLANs
Revisiting the Hidden terminal Problem in a CSMA/CA Wireless Network