WiFi Case Studies Nadeem Akhtar Principal Wireless Architect

Wi-Fi Case Studies Nadeem Akhtar Principal Wireless Architect, Mojo Networks

Overview • Case Study 1 • Wi. Fi deployed in hostel of an educational institution • Focus on identifying cause(s) of poor performance • Case Study 2: Mall • Large scale Public Wi. Fi deployed • Focus on identifying KPIs to measure network quality 2 © Mojo Networks. Confidential Information.

Case Study 1: Educational Institution • 16 Floor Hostel • Each floor with 26 rooms, 2 students per room 3 © Mojo Networks. Confidential Information.

Issues Coverage Holes 4 © Mojo Networks. Confidential Information. Noisy Neighbours

Issues Legacy Clients 5 © Mojo Networks. Confidential Information. Misbehaving Users

Survey Data Interference 6 © Mojo Networks. Confidential Information. Client Protocol Distribution

Survey Data 7 © Mojo Networks. Confidential Information.

Proposed Solutions • RF Issues • Coverage enhancement by adding more APs per floor • To improve 5 GHz usage • • Provide dual-band Wi. Fi dongles for old laptops New students to procure laptops with 802. 11 a/b/g/n support • Enable band steering to offload dualband clients to 5 GHz band • Enable smart steering to reduce the number of sticky clients • Discuss with neighboring Wi. Fi owners to reduce signal leakage 8 © Mojo Networks. Confidential Information. • Fair and responsible usage • Per user BW restriction to prevent BW hogging • Prevent the creation of personal hotspots • Debar clients which are using static IP addresses

Case Study 2 1500+ sites • 8 k+ Operational Access Points Mixed set of sites • • 9 Retail Hotels Airports Schools/Colleges/Universities © Mojo Networks. Confidential Information.

Challenge How to determine the health of each AP and overall state of the network 10 © Mojo Networks. Confidential Information. Opportunity Availability of 100 s of performance metrics

Methodology Identify a basic set of parameters which affect the network performance 11 © Mojo Networks. Confidential Information. Isolate a small set of metrics to capture AP and Clients Health Generate a composite Health Index to indicate overall network state

Key Metrics • • • 12 Tx/Rx Data Rate Tx/Rx Utilization Client Count Session Count/Duration Tx/Rx Bytes Retry Rate RSSI SNR RF Quality … © Mojo Networks. Confidential Information.

Client Health 13 © Mojo Networks. Confidential Information.

Client Health SNR (d. B) 14 © Mojo Networks. Confidential Information. Ranking on Five Pointer Scale 1 Conclusion 2 Fair 3 Good 4 Very Good 5 Excellent Poor

AP Health 15 © Mojo Networks. Confidential Information.

AP Health Retry Error % 16 © Mojo Networks. Confidential Information. Ranking on Five Pointer Scale 1 Conclusion 2 Fair 3 Good 4 Very Good 5 Excellent Poor

Performance Health Index • For measuring the overall health of the system, we propose a Performance Health Index, ɸ = (α 1*x 1+ α 2*x 2) where, x 1 = SNR Rank, x 2= Retry Rate Rank α 1 and α 2 are weights which reflect the relative importance of each individual parameter on overall health of the system. α 1 and α 2 are positive numbers such that α 1 + α 2 = 1 17 © Mojo Networks. Confidential Information. PHI Value Conclusion Poor Fair Good Very Good Excellent

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