IEEE 802.11n

1
IEEE 802.11n High Throughput

• Will enable new consumer, enterprise applications
• Video distribution, more bandwidth for QoS
  applications, greater range, throughput
• High Data rates (64-600Mbps)
• A typical 2 transmitter MIMO device will support
  a 300Mbps data rate when using 40MHz channel
• 144Mbps data rate when using 20MHz channel
• Legacy mode support
• Support for Legacy a/b/g, e.g. 802.11n AP and
  a/b/g STAs
• Support for Mixed Mode e.g. 802.11n AP and
  a/b/g/n STAs
• Green Field 802.11n-only

2
New components in IEEE 802.11n

• PHY Enhancements, applicable to both 2.4GHz and
  5GHz
• The new PHY supports OFDM modulation with
  additional coding methods, preambles, multiple
  streams and beam-forming
• Multiple Input Multiple Output (MIMO) Radio
  Technology With Spatial Multiplexing
• High throughput PHY 40 MHz channels Two
  adjacent 20 MHz channels are combined to create a
  single 40 MHz channel.
• MAC Enhancements
• Two MAC aggregation methods are supported to
  efficiently pack smaller packets into a single
  MPDU
• Block Acknowledgement A performance
  optimization in which an IEEE 802.11 ACK frame
  need not follow every unicast frame and combined
  acknowledgements may be sent at a later point in
  time.

3
What is MIMO?

• Multiple Input Multiple Output (MIMO)
• Transmit and Receive with multiple radios
  simultaneously in same spectrum

4
Spatial Division Multiplexing

• Multiple independent data streams are sent
  between the transmit and receive antennas to
  deliver more bits in the specified bandwidth

5
What Does this Mean to Education

• Pre-N Products will show up in your air
• Effective air monitoring WIDS tools
• Enterprise Draft-N products in 2007
• Start pilots for high bandwidth apps
• Draft-N clients start to show up in high-end
  laptops
• Mass adoption in 2008
• Standard ratification expected in 1H2008
• Price-performance targets will be met for mass
  adoption
• 802.11n clients will become ubiquitous
• What does this mean to you
• Wireless becomes the ONLY connection from PRIMARY
• Extending mobile security to legacy wired ports
• New high performance 802.11a/b/g/n Access Points
• Higher Performance Mobility Controllers
• Control and Data Plane Scaling Intelligence

6
Agenda

• Introduction to Aruba Networks
• 802.11n
• Smart Antennas
• How Dartmouth Implemented Voice, Video and Data
  over Wi-Fi

7
Smart Antennas for Wi-Fi Stability

• Applies MIMO-diversity techniques to standard
  Wi-Fi
• Intuitive antennas (continuous learning)
• 2 to 3X range and performance increase
• Active interference rejection
• Compatible with all 802.11 standards
• Compact internal antenna array
• Capable of 63 unique antenna patterns
• Increased range and better performance in any
  direction at any time
• Expert control software constantly ranks optimum
  antenna patterns for each receiving device

Six high-gain directional antenna elements
8
Avoiding Interference with Smart Antennas
Bedroom
Home office
Ruckus AP
Kitchen
Family Room
BeamFlex Powered Set Top Box
9
What Interference Avoidance Looks Like

• 3-minute throughput measurements per test
• Microwave on after 1st minute
  for 1-minute

Off-the-shelf 802.11 AP to Off-the-Shelf 802.11g
Client
Ruckus 2900 AP to Off-the-Shelf 802.11g Client
10
What About 802.11n?
More Wi-Fi Capacity is Good but Not Good Enough

• Spatial multiplexing improves top line bandwidth
• Critical for HD streaming (WMV-9 at 9-12 Mbps
  per stream)
• Multiple signals increase chance of experiencing
  interference, decreases the chance of Wi-Fi
  stability
• Streams take different paths making it harder to
  recover at receiving end
• No predictability - at the mercy of wild signal
  scattering
• No inherent QoS
• Smart Wi-Fi technology sits on top of 802.11n
  fixing these problems

11
Giving 802.11n Stability
Data Grade Performance
(_at_ 50 Percentile of Throughput Distribution)
Video Grade Performance
(_at_ 99.5 Percentile of Throughput Distribution)
BeamFlex on Standard .11G
MIMO, Draft-N

• Test Environment Methodology
• 3,000 sq-ft, 2-story US Residential House
• UDP echo test
• 5,000 measurements taken per AP per location at
  50ms intervals measurements sorted by
  distribution to report the throughput at 50th and
  99.5th percentiles
• Test Date May 08, 2006