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1 © 2012 XIRRUS :: All Rights Reserved © 2012 XIRRUS :: All Rights Reserved
DESIGNING FOR HIGH PERFORMANCE
MAY 2012
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MOBILITY IS #1 ISSUE FACING ENTERPRISE IT TODAY
• Organizations increasingly depend on wireless to transform their business Highly mobile workforce Business processes relying on wireless and cloud access Need for frequent, real-time interaction
• Redefining the way organizations interact with users Enhanced productivity is the primary benefit of wireless investment
• ‘Wireless First’ or ‘Wireless Only’ is the new reality Raises the bar for network Reliability, Performance and Scalability
• Most of today’s wireless networks are not appropriately designed for these new requirements – design approaches must change
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TIM ZIMMERMAN
“Without Proper Planning, Enterprises Deploying iPads Will Need 300% More Wi-Fi.”
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WHAT ARE THE KEY DESIGN PARAMETERS FOR A WI-FI NETWORK?
• Start by defining areas to covered with floor plans for all buildings/areas
• What type of clients will be supported? Laptops, tablets, smartphones, etc.
• What bands do the supported client devices operate in? 2.4G and/or 5G
• What areas have high density requirements? How many simultaneous clients in one area? Average bandwidth needed per client?
– 500Kbps for general Internet access – 1Mbps to add basic streaming video – More for instructional or coordinated activities
• What are the construction materials?
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HOW IS THE TYPE OF DEVICE IMPORTANT TO THE WI-FI DESIGN?
• Different Wi-Fi devices operate fundamentally distinct from each other on the wireless network.
• With tablets/smartphones showing up everywhere on the network, they are the lowest common denominator for most designs today
Device 2.4GHz 5GHz Max Rate Survey Criteria
POS scanner X X 54Mbps Varies Location tags X NA > -60dBm Media Players (iPod Touch) X 65Mbps > -65dBm Smartphones (iPhone) X Few 65Mbps > -65dBm Tablets – low end (Kindle) X 65Mbps > -65dBm Tablets – mid/high end (iPad) X X 65Mbps > -65dBm Netbooks X Some 300Mbps > -70dBm Laptops X X 300Mbps > -70dBm
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RF DESIGN APPROACHES
• Two types of RF site surveys 1. Predictive
• Based on floor plans and other information provide by customer • No equipment actually used • Can be performed remotely if appropriate information available
2. Active • Live survey with actual equipment • Conducted at the customer premise • Optional pre-install if a good predictive design can be done, but should
always be done after install to verify the implementation
• Xirrus Wi-Fi Designer application incorporates both types
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WHAT ARE THE MOST IMPORTANT RF DESIGN BEST PRACTICES?
• Determine signal criteria required based on device usage: Laptop usage = -70 dBm minimum RSSI Smartphone/Tablet/VoWiFi usage = -65dBm minimum RSSI
• Design for coverage in all areas for both 5GHz and 2.4GHz • All locations should see multiple radios
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HOW DO YOU DESIGN FOR WI-FI CAPACITY?
• Methodology Determine mix of 2.4G and 5G radios
• If primarily smartphones, maximize 2.4GHz, but also provide full 5GHz • If tablet and laptop use also, increase percentage of 5GHz radios
Determine per radio bandwidth by dividing max data rate by 3 • 20Mbps per radio for tablets and smartphones (65Mbps max rate) • 100-150Mbps per radio for laptops if 11n (300-450Mbps max rate)
Determine radio count per Wi-Fi band • Radios = (Devices * BW per Device) / BW per Radio
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HOW DO YOU DESIGN FOR WI-FI CAPACITY?
• General guidelines for device density per radio High performance = <5 (Ethernet replacement) Medium performance = <15 (General laptop & tablet support) Low performance = <40 (General Internet access)
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WHAT ARE BEST PRACTICES FOR ULTRA-HIGH DENSITY DESIGN?
1. Maximize 5GHz Band steer devices to 5GHz if they support, minimize 2.4G
2. Disable 11n bonding Maximizes number of 5GHz channels for the design
3. Limit SSID count Each adds significant overhead to the Wi-Fi channel
4. Turn off 11b Very few 11b only clients out there, negatively impacts performance
5. Filter traffic Keep peer-to-peer, broadcasts, netbios, Bonjour, etc. off the air
6. Rate limit clients 500Kbps cap for general browsing, higher if additional services (video)
7. IP addressing Ensure big enough space allocated and DHCP lease times limited
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WHO IS XIRRUS?
• Vision
Wireless replaces wired as the primary choice for network access.
• Mission
Lead the transformation from wired to wireless by providing the most powerful, scalable and trusted access solutions to organizations who increasingly depend on wireless.
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THANK YOU