Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

802.11n Technology - Presented by Meru Networks and DTC

1,535 views

Published on

This is the Webinar DTC and Meru Networks hosted on 8/25.

Discussed is 802.11n technology and How Meru Networks addresses of the problems seen in the market with other Wireless Network providers.

Published in: Technology, Business
  • Be the first to comment

802.11n Technology - Presented by Meru Networks and DTC

  1. 1. 802.11n – The New Edge NetworkAccess in a post-switching world<br />Matt Johnson, Technical Solutions Director, West Area<br />
  2. 2. Meru Networks Company Overview<br />Founded in 2002, Sunnyvale, CA, USA <br />Operations in North America, APAC, EMEA<br />NASDAQ Listed – “MERU”<br />Mission: Deliver Wireless-like-Wire™ experience to the enterprise <br />Virtualized Wireless LAN innovation<br />5,000+ customers in 55 countries worldwide<br />Category Leadership<br />Enterprise 802.11n solutions pioneer<br />Wireless VoIP, Video/HD video<br />Converged applications at scale<br />Device and user density, seamless mobility, QOS<br />Fixed Mobile Convergence<br />Enterprise WLAN service assurance<br />
  3. 3. The Network Edge Design TodayOptimized for Cubicles and Desktops<br />The Wiring Closet<br />The Office<br />AGGREGATION Services<br />CORE Services<br />
  4. 4. Mobility is THE Default Today’s edge networks were NOT designed for this!<br /><ul><li>Devices with NO Ethernet Port surpass those with Ethernet ports in 2011
  5. 5. Enterprise IT must adapt!</li></ul>Smart Devices Grow 4x<br />Source: Rohit Mehra - IDC<br />
  6. 6. Today’s Edge Is Dead!Network access is predominantly mobile!<br />The New Wiring Closet<br />The New Office<br />AGGREGATION Services<br />CORE Services<br />
  7. 7. The New Edge is Untethered<br />Mobile<br />Dense<br />Diverse<br />
  8. 8. The New Edge is Multi-Media<br />Video<br />Voice<br />Data<br />
  9. 9. The New Edge is Distributed<br />Campus<br />Branch<br />Telecommuter<br />
  10. 10. What makes wireless for the Edge possible?ANSWER: 802.11n<br />Definition<br />“IEEE 802.11n-2009 is an amendment to the IEEE 802.11-2007 wireless networking standard to improve network throughput over the two previous standards—802.11a and 802.11g—with a significant increase in the maximum raw data rate from 54 Mbit/s to 600 Mbit/s with the use of four spatial streams at a channel width of 40 MHz.”<br />Source: www.wikipedia.org<br />
  11. 11. Wireless connection speed nears wired speed<br />
  12. 12. Promise of 802.11n<br />Better coverage<br />Higher throughput<br />Improved coverage through multipath and MIMO; multiple transmit and receive paths<br />Over 6 times better than 802.11a/g *<br />Longer range<br />More reliable<br />Longer range: Over 2 times better than 802.11a/g *<br />More resistant to interference and loss due to multipath *<br />* Based on specifications in the standard.<br />
  13. 13. Multiple-In, Multiple-Out<br />Converts multipath into an advantage<br />Does the “impossible”: two transmissions at the same time<br />More Efficient Radio (PHY)<br />More OFDM carriers per stream<br />Faster coding rate per stream<br />Highest rate: 65Mbps; Lowest rate: 6.5Mbps<br />More Efficient MAC<br />Packet Aggregation<br />Bursting<br />Newer sleep modes<br />Double-wide Channels available<br />a<br />b<br />g<br />n<br />802.11n = 6x Throughput; 2x Range<br />
  14. 14. How Does 802.11n Work? Multiple Input Multiple Output<br />Radio<br />Radio<br />MIMO<br />Multiple “chains” per radio<br />Doubles Throughput<br />Radio<br /><ul><li>Multiple “spatial streams” at the same time
  15. 15. Advanced RF separates the streams and doubles throughput</li></li></ul><li>How Does 802.11n Work? Channel Bonding and Packet Aggregation<br />40MHz Channels<br />Adjacent channels “bonded” into one<br />Doubles Throughput (again)<br /><ul><li>Packet Aggregation
  16. 16. Multiple packets in one shot: Block ACKs</li></ul>More Efficient<br />A-MPDU<br />D<br />D<br />D<br />D<br />D<br />D<br />Block ACK<br />A<br />A<br />A<br />A<br />A<br />A<br />
  17. 17. <ul><li>Note:</li></ul>(Fundamental to 802.11n: the weakest link dominates)<br />More Range and Robustness<br />11abg Range<br />11n Range<br />Range Extension<br />More SNR  Better Robustness  Better Range<br />Throughput<br /><ul><li>Thus,
  18. 18. Different Ranges for Different Clients on the same AP</li></ul>Distance<br />
  19. 19. 2x2, 3x2, 2x3, 3x3, …<br />What does this mean?<br />Number of Chains = Number of Antennas used at any one time<br />NotNumber of Spatial Streams!<br />Number of Spatial Streams = 3 or less, always<br />3x_  _x3<br />3 Tx Antennas<br />3 Rx Antennas<br />
  20. 20. What does this mean?<br />Number of Chains = Number of Antennas used at any one time<br />NotNumber of Spatial Streams!<br />Number of Spatial Streams = 3 or less, always<br />2x2, 3x2, 2x3, 3x3, …<br />3x_  _x2<br />3 Tx Antennas<br />2 Rx Antennas<br />
  21. 21. What does this mean?<br />Number of Chains = Number of Antennas used at any one time<br />NotNumber of Spatial Streams!<br />Number of Spatial Streams = 3 or less, always<br />2x2, 3x2, 2x3, 3x3, …<br />2x_  _x3<br />2 Tx Antennas<br />3 Rx Antennas<br />
  22. 22. 2x2, 3x2, 2x3, 3x3, …<br />What does this mean?<br />Number of Chains = Number of Antennas used at any one time<br />NotNumber of Spatial Streams!<br />Number of Spatial Streams = 2 or less, always<br />2x_  _x2<br />2 Tx Antennas<br />2 Rx Antennas<br />
  23. 23. Why Meru for 802.11n<br />Meru was founded to solve common RF issues in order to allow coexistence of Voice, Video, and high volume of Data users across an 802.11 Network.<br />
  24. 24. Let’s review the problems with WiFi today<br />Problem #1 – Most wireless access points perform like old wired Ethernet hubs.<br />Problem #2 – Wireless devices make connection and roaming decisions.<br />
  25. 25. Fundamental Problem number 1: APs are hubs<br />Active Users Per AP<br />>100<br />11<br />Baseband + Protocol Overhead<br />8<br />5X<br />Total Bandwidth at Peak <br />(Mbps)<br />5<br />Contention<br />Loss<br />Today’s APPerformance<br />20-25<br />Today<br />Meru<br />20<br />1<br />3<br />Number of Active Users<br /><ul><li>Multiple clients contend for the same shared medium
  26. 26. While transmitting sender cannot listen for collisions
  27. 27. As number of calls goes up, collisions increase
  28. 28. Collisions cause clients to back off
  29. 29. Back off slows down network</li></li></ul><li>Frisky client: ping-pongs between APs<br />Fundamental Problem #2: WLAN Client makes decision<br />Client-initiated roaming<br />Clients must scan each channel for strongest signal<br />Connectivity depends on each client’s implementation of roaming algorithms <br />Risk of dropped calls, interrupted data sessions<br />Searching for signal wastes power, reduces battery life<br />Client has no knowledge of each AP’s load, may overburden one AP while another is free<br />Client may enter “dead zone” with no coverage at all<br />Sticky client:<br />remains connected to AP even when coverage is good<br />
  30. 30. This leads to…..<br />Lower than expected client counts per AP<br />Sticky clients<br />Clients that ping pong between APs<br />Dropped sessions when clients move around<br />Unequal distribution of client on APs<br />No fairness among users that are connected<br />Lack of QOS for real-time applications like voice<br />Interference among APs<br />Difficulty in trouble shooting issues<br />
  31. 31. Solution to the Problems:Meru Air Traffic Control<br />Patented control mechanism that times user transmissions resulting in:<br />Little to no contention loss so many more users possible<br />Fairness for all users even without QOS settings<br />Cleaner RF<br />APs coordinate activities:<br />No co-channel interference<br />Load balancing<br />No ping ponging<br />Seamless Roaming<br />A network of APs – Not islands<br />
  32. 32. Solution to the Problems:Virtualization of users<br />Multiple access points appear as one<br />One channel<br />One BSSID<br />Handoff eliminated<br />Network controlled<br />Connections load-balanced across APs<br />Network uses its awareness of traffic conditions to route packets over the air<br />Virtual Cell<br />Access Point<br />Access Point<br />Access Point<br />
  33. 33. Meru Virtualized WLAN DifferentiationVirtualize + Optimize the RF Resources<br />Legacy<br />Meru<br />Pooling<br />Virtualized<br />Microcell<br /><ul><li>Single channel – adding new AP’s simple as installing a light bulb
  34. 34. Harness every MHz everywhere
  35. 35. Seamless mobility</li></ul>Partitioning<br />Switch<br />Hub<br /><ul><li>Dedicated connection per device
  36. 36. Network guarantees each device its fair share of the air
  37. 37. Quality of service per application type</li></li></ul><li>Meru AP Performance<br />Meru: Wireless LAN VirtualizationVirtual Port™<br />Microcell functions as hub<br />Peak Aggregate Throughput <br />11<br />Baseband + Protocol Overhead<br />8<br />5<br />Total Bandwidth at Peak<br />(Mbps)<br />Contention<br />Loss<br />802.11 MACPerformance<br />1<br />20-25<br />3<br />Meru delivers switch-like predictability and performance<br />Number of Active Users<br /> Predictable throughput<br />Supports more clients<br />‘Wire like’ predictability<br />High quality Voice and Video<br />Delivers greater throughput<br />
  38. 38. Because of Air Traffic ControlTraffic Separation<br />Voice: Highest QoS, Admission Control<br />Video: Second QoS, Rate Limited<br />Application-Aware<br />Flow Detection<br />Data: Best Effort, Airtime Fairness<br />
  39. 39. CH 1<br />CH 11<br />CH 6<br />CH 1<br />Design Considerations<br />Lack of Site Planning Tools<br />Channel Planning Challenges <br />Migration of infrastructure from .11a/g to .11n<br />Two Different channel plans for 2.4 and 5 GHz using same AP chassis<br />Increase in interference with Increase in range <br />Power over Ethernet <br />"Site surveys will be of marginal use in 802.11n environments”<br />- Ken Dulaney, VP Distinguished Analyst, Gartner<br />30<br />
  40. 40. Summary of Meru Advantages<br />Predictable and reliable performance for all users<br />Fairness among all wireless devices<br />Highest density of users per radio vs other vendors<br />A wireless network that supports multimedia<br />Wireless network free of co-channel interference<br />Network is in control of the wireless client (seamless roaming)<br />Simplicity of design and ease of implementation<br />Advanced Troubleshooting tools<br />Better ROI and less OpEX<br />
  41. 41. Thank you<br />

×