2. Mobility at CERN 29/10/2013 HEPiX Fall 20132 Sebastien.Ceuterickx@cern.ch IT/Communication Systems HEPiX Fall 2013

3. Agenda Evolution of Wi-Fi at CERN BYOD impact Special Wi-Fi deployments Eduroam@CERN 29/10/2013 HEPiX Fall 20133

4. Development of the CERN Wi-Fi 29/10/2013 HEPiX Fall 20134 4,000 simultaneous users 1,400 Access points 280,000m2 covered 7,000 unique devices per day 7 Gbps of traffic Early 2007 x 6 Devices in 6 years

5. Wi-Fi is complex 29/10/2013 HEPiX Fall 20135 The challenges: - client related issues - infrastructure issues: -deployment challenges -sources of interference - (high) density issues - a combination of all factors - expected QoS from the user’s point of view

6. Challenges: client issues 29/10/2013 HEPiX Fall 20136

7. Challenges: a diverse infrastructure 29/10/2013 HEPiX Fall 20137

8. Challenges: A large and dynamic environment 600,000m 2 indoor area (+20% in 6 years) 650 surface buildings (+15% in 6 years) 2,100,000m 2 outside area (stable) New experiments Building refurbishment HEPiX Fall 20138 29/10/2013

9. Challenges: intensive usage From an extension of the structured cabling to fundamental service HEPiX Fall 20139 29/10/2013 The primary connection for an increasing number of devices

10. How do we address this? HEPiX Fall 201310 29/10/2013

11. Optimizing RF spectrum! Migration from 802.11bg to 802.11n 5GHz Up to 240Mbps half-duplex shared From 200m2 per AP to 120m2 (-40% ) Increase the density of APs HEPiX Fall 201311 Avoid the 2.4GHz Band where possible 29/10/2013

12. Turning ON is not enough Band steering Load balancing Auto-channel assignment Auto-power tuning HEPiX Fall 201312 Might not work out of the box RF planning and site survey still required Wi-Fi tuning necessary 29/10/2013

13. Automation for scalability HEPiX Fall 201313 Automated RF configuration Simplify Save resources Increase reliability Data Base Network Management System 29/10/2013 Integrated within global NMS

14. Control, act and support HEPiX Fall 201314 Efficient monitoring and analysis system deployed Remote operation Proactive optimization Efficient end-user support 29/10/2013

15. Ban them ?? BYOD: The impact HEPiX Fall 201315 802.11n compliant BUT… 1 spatial stream (75Mbps max) Reduced Wi-Fi performance Ban (very) poor connectivity Optimize RF planning Increase AP density 29/10/2013

16. Special deployments HEPiX Fall 2013 16 29/10/2013

17. Conference rooms HEPiX Fall 201317 Efficient RF planning for Minimizing interference Optimizing load sharing Capacity is the key concern. Reduce Tx Power Ban slow stations & low data rates Enable band steering and airtime fairness Use external antennas 29/10/2013

18. Underground caverns HEPiX Fall 201318 Efficient RF planning for Minimizing co-channel interference Maximizing coverage Coverage is the key concern. Disable band steering Enable RTS/CTS Use external antennas and power dividers Use a leaky feeder 29/10/2013

19. eduroam@CERN HEPiX Fall 201319 29/10/2013

20. Travelling? Take Internet access with you! A secure international roaming service Based on a federation of RADIUS servers HEPiX Fall 201320 Home Institute 29/10/2013

21. How do we deploy it? freeRADIUS certificate based for CERN user (EAP-TLS ) No additional hardware Fully automated Pilot version running end 2013 : 80% of the infrastructure HEPiX Fall 201321 29/10/2013

22. Conclusion WLAN at CERN will continue to grow. Wi-Fi has became a (highly) popular and fundamental service which requires a significant investment to work properly in a professional environment. 802.11ac will bring new opportunities --- and new challenges. HEPiX Fall 201322 29/10/2013

23. Thank you! Question HEPiX Fall 201323 29/10/2013

24. Future HEPiX Fall 201324 29/10/2013

25. 802.11ac 5 GHz only New higher rate modulation Will be release in 2 “waves” HEPiX Fall 201325 Wave 1 (2013)Wave 2 (2015) Up to 80MHzUp to 160MHz Up to 3 spatial streamsUp to 4 spatial streams Single-User MIMOMulti-User MIMO Up to 650MbpsUp to 1732Mbps 29/10/2013

26. New opportunities… …new challenges Higher throughput Better performance at the same range Impact on infrastructure ? Impact on RF planning ? Higher rate only at short range (-55dBm = same room) HEPiX Fall 2013 26 29/10/2013