Wi-Fi Design 1. Primary Coverage Goal 3. Capacity Plan CRITICAL DESIGN ASPECTS RF DESIGN PROCESS HIGH PERFORMANCE WI-FI TIPS & TRICKS OBJECTIVES 4 Provide Wi-Fi service in all required locations 4 High quality signal strength 4 Maintain high data rates RESULTS 4 Improve airtime efficiency 4 Improve density handling RESULTS 4 Optimal number of APs 4 Proper client distribution between 5 GHz and 2.4 GHz 4 Leave idle airtime for growth CONSIDERATIONS 4 More spectrum in 5 GHz provides up to 8x the capacity of 2.4 GHz 4 Understand client mix 4 Client offered load / SLA 4 Model airtime demand 4 Understand airtime saturation limits (80% BE, 50% BE/VO/VI, 35% VO) Client Device Efficiency 2. Secondary Coverage Goal 4. Minimize Interference 3. POST INSTALLATION VALIDATION 4 RF site survey (passive / active / spectrum) 4 RF tuning channel and power plans 4 Association and authentication tests 4 Roaming tests 4 Spectrum analysis 1. GATHER REQUIREMENTS 4 Blueprints / CAD drawings 4 Coverage areas 4 Facility layouts & construction materials 4 Client number and mix 4 Client density distribution 4 Critical applications / business process 2. PRE – INSTALLATION DESIGN 4 Predictive modeling 4 Wall alternation measurements 4 “AP on a stick” measurement 4 Wired network integration OBJECTIVE 4 Provide coverage for 2 APs in each location RESULTS 4 Improve client roaming 4 Low latency roaming for real-time application 4 Redundancy for AP failure OBJECTIVES 4 Isolate APs on same channel 4 Reduce shared airtime 4 Limit contention domains 4 Eliminate external interference RESULTS 4 Minimize co-channel interference (CCI) and adjacent channel interference (ACI) between APs on the same or overlapping channels 4 Ideally, only one AP audible on each channel in a physical location 4 Ideally, remove sources of external RF interference or avoid impacted channels if they cannot be removed LOW MED HIGH Low Client Density 1. Design for 5 GHz as Primary 4 The 5 GHz band provides 8 times the capacity of 2.4 GHz 2. Define Coverage Goal(s) 4 Too aggressive can lead to co-channel interference 4 Too conservative can lead to poor client performance 3. Place APs Where Users Are Located 4 In-room placement is best for client performance 4 Avoid hallways, if possible, unless required for voice roaming 4. Tailor Coverage to the Facility 4 Leverage RF obstructions for frequency re-use 4 Consider proper antennas and orientation for signal propagation 5. Fine Tune AP Power Levels 4 Align with on-site signal measurements of RF propagation 4 Align with AP density and frequency re-use requirements 6. Disable 2.4 GHz Radios if Necessary 4 There are fewer available channels in 2.4 GHz 4 Disabling radios can prevent co-channel interference and shared capacity between clients 4 Some APs allow switching 2.4GHz radio to 5GHz 7. Design and Validate with Representative Client Devices 4 Spot-check with actual client devices to ensure the design matches actual client performance 4 Alternatively, measure with a standard RF site survey adapter and compensate the signal based on actual client device characteristics 8. Higher AP Density Requires Smaller Channel Widths 4 Reduces co-channel interference and shared capacity between clients 4 Reduces client contention and improves network stability 9. Disable Low Data Rates to Improve Performance 4 802.11b clients can significantly impact network performance 4 Reduces overhead from management frames and broadcast/multicast traffic 10. Minimize the Number of SSIDs 4 Network overhead increases with each SSID defined CLIENT HEARS PRIMARY AP CLIENT HEARS PRIMARY AND SECONDARY APS Ch 1 Ch 1 Ch 1 Ch 1 High Client Density 1 2 3 MICROWAVE OVEN INTERFERES WITH WI-FI DEVICES RESULTS IN CCI BOTH APS ON CHANNEL 1 Content provided by