IEEE 802.11n – High Throughput

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. Radio Radio channel DSP DSP Bits Radio Radio Bits Radio Radio TX RX • Compare to traditional Single Input Single Output Radio (with optional receive diversity) channel Bits DSP DSP Radio Radio Bits TX RX What is MIMO? • Multiple Input Multiple Output (MIMO) • Transmit and Receive with multiple radios simultaneously in same spectrum

4. Radio Radio DSP DSP More Bits Radio Radio More Bits Radio Radio TX RX • Cross-paths between antennas are automatically decoded by the receiver, assuming sufficient “richness” in the propagation environment 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 1H’2008 • 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. Interference from neighboring network 1 1 3 2 2 Microwave Avoiding Interference with Smart Antennas Bedroom Home office Ruckus AP Kitchen Family Room BeamFlex Powered Set Top Box

9. Ruckus 2900 AP to Ruckus 2501 Client Client Microwave 30 ft AP 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. BeamFlex over .11N 5 ft, LOS 5 ft, LOS 26 ft, 1 stucco wall 26 ft, 1 stucco wall 56 ft, 1 stucco & 1 granite walls 56 ft, 1 stucco & 1 granite walls 41 ft, 2 stucco & 2 exterior walls & bathroom 41 ft, 2 stucco & 2 exterior walls & bathroom 40 ft upstairs, 3 stucco walls and 1 floor 40 ft upstairs, 3 stucco walls and 1 floor Ruckus 2221AP & 2501 Adapter (Atheros 802.11b/g Chipset) Netgear RangeMax 240 Router & PC Card (Airgo Gen3 MIMO Chipset) Netgear RangeMax Next Gigabit Edition Router & PC Card (Marvell Draft-N Chipset) Giving 802.11n Stability Data GradePerformance (@ 50 Percentile of Throughput Distribution)* Video GradePerformance (@ 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