1. Evolution of mobile telephony and data at CERN
Rodrigo Sierra
Communication Systems group, IT Department, CERN

2. Agenda CERN mobile services Mobile services evolution
Mobile network migration
Department challenges
Advanced services
Migration process & planning
Mobile data evolution
Conclusions

3. CERN mobile services Mobile services: Infrastructure Technologies
Single contract with a Swiss operator
Closed VPN comprising > 5800 mobiles
Voice and data services (including UMTS/3G and LTE/4G)
Mobile calls from Switzerland routed via the CERN telephone exchange
Dedicated access to CERN’s Intranet
To allow secured and controlled access to CERN intranet servers
Roaming worldwide
Infrastructure
> 50 km of leaky feeder cable covering underground facilities
CERN’s own infrastructure to cover LHC tunnel
68 radio/transmission sites at CERN
Technologies
GSM, UMTS (3G) and LTE (4G)

4. Evolution - Déjà vu! UPS for mobile sites - 2010
SIM cards replacement
3G in LHC (UMTS900) – 2012
3G in the injector chain – 2013
Mobile network SWAP – 2013
Sunrise network evolution
LTE pilot in LHCb (L800)

5. Evolution - Déjà vu? 3G & LTE in all underground facilities
3G & LTE on surface in… France
> 100Mbps DL in the caverns
Having very interesting tariffs?

6. Mobile network migration
What?
Swisscom will replace Sunrise the 1st of July 2015
Why?
Swisscom has won the call for tender for mobile services
When?
Installation started in January
All services should be ready in June
The operator will be swapped the 1st of July
How?
Swisscom’s network is being installed while Sunrise’s one is still in operation
Sunrise will be decommission once Swisscom is operational

7. Mobile network migration
Mobile services will be improved:
LTE (4G) in the Swiss part
UMTS (3G) and LTE (4G) in the French part (authorization pending from French regulator)
UMTS (3G) and LTE (4G) in the underground facilities
LTE-Advanced in the LHC experiments: 150Mbps DL
Reminder: No Wi-Fi in the tunnels after LS1
New tariffs:
Very interesting tariffs negotiated (~ 50% reduction in average)
New operator:
New SIM card and new number

8. Mobile network migration
Network deployment
The network must be installed while operating the current one:
New space, fibers & power supplies required in all sites
New mast/antennae for outdoor coverage
Network complexity:
2G, 3G and 4G in all sites
14 outdoor sites
37 indoor sites: LHC & injector chain covered
17 CERN indoor sites in the LHC (REs & TI8)
Advanced services must be integrated:
CERN APN, roaming control, PBX interconnection…
French and Swiss regulation:
Radio emission
Construction permits
The new network must be ready in 6 months

9. Architecture

10. Architecture Underground facilities > 50 km of leaky feeder cable
2G, 3G, 4G, TETRA & TETRAPOL
Signal overlap for redundancy and capacity
Frequency and technology planning

11. Departments collaboration
Contract – FP
Legal permits & authorizations - DG
Integration of racks and cabling – EN & GS
Power supplies for all sites - EN
100s of fibers to be pulled - EN
Civil work to build outdoor sites - GS
Temporary storage & transport- GS
SIM card distribution – Secretaries
CERN administrative tools & billing - GS

12. IT department challenges
Deployment in 6 months
Coordination
Regulators and legal entities
New numbering plan
Fixed-line network moved to Swisscom
Infrastructure compatibility with LTE
Advanced services
SIM card migration
‘Seamless’ operator migration

13. Advanced services CERN intranet connection CERN voice VPN
CERN PBX interconnection
2SMS gateways
Roaming cost control
Automatic billing
User provisioning

14. CERN intranet connection
CERN intranet connection (CERN APN):
Fixed IP address related to the phone number (16abcd -> ab.1cd)
Internet APN by default:
Swisscom IP address

15. CERN voice VPN

16. SIM cards migration ALL SIM cards must be changed (~6000)
Sunrise SIM cards will stop working in July
Distribution of Swisscom SIM cards in June via secretariats and Labo Telecom
Special procedures:
Modems
Users not at CERN in June
Planning, FAQ, procedures…
To be published in

17. Seamless migration Number change (16xxx won’t change)
All subscriptions activated simultaneously
Surface:
Negotiating some days of overlap
Underground facilities:
Only one operator available at the same time
Sunrise subscription will stop the 1st of July:
Sunrise numbers redirected to a voic in July

18. Mobile data evolution

19. Mobile data evolution Cake (throughput): Shannon’s:
Baking sheet (bandwidth)
Thickness (power – S/N)
Slices (time)
Ingredients (technologies)
Density (latency)
Shannon’s:
𝐶 =𝐵𝑊× 𝐿𝑜𝑔 2 (1+ 𝑆 𝑁 )
Time
Power
Bandwidth

20. Frequency Division Duplex
Downlink and Uplink separated in frequency
Uplink limited by terminal power (battery) & Noise
Downlink
Uplink

21. GSM (2G) FDMA -> Low bandwidth (200KHz)
TDMA -> Channel divided in 8 slots
Ingredients:
Old technology (early 90s)
Designed for voice
High latency
1 slice of a cookie difficult to digest
9.6 kbps DL & UL
Latency: ~ seconds

22. GPRS (2.5G) FDMA -> Low bandwidth (200KHz)
TDMA -> Up to 4 slots DL and 2 UL
Ingredients:
GSM technology
New coding scheme
Several slices of a cookie difficult to digest
80 Kbps DL & 40 Kbps UL
Latency: ~ 1s

23. EDGE (2.75G) FDMA -> Low bandwidth (200KHz)
TDMA -> Up to 5 slots DL and 3 UL
Ingredients:
GSM technology
8PSK modulation
New coding scheme
Several slices of a healthy cookie
296Kbps DL & 177.6Kbps UL
Latency: ~ 150ms

24. UMTS (3G) WCDMA: Ingredients: One cake easy to digest
High bandwidth (5MHz)
Code division -> No more time slots
Ingredients:
Code control
Power/noise control
Computational power
One cake easy to digest
384 Kbps DL & UL
Latency: ~ 150ms

25. UMTS evolution (3.5G) Powerful devices: Smartphones
More ingredients Downlink:
Modulation (16QAM, 64QAM) -> x2, x3
Number of codes (10, 15) -> x2, x3
Multi-carrier -> x2, 4…
MIMO -> x2, 4…
One healthy big cake
21/42/84… Mbps DL & 5.6/12/23/70… Mbps UL
Latency: < 50 ms

26. CERN ‘allergies’ Ingredients: Antihistaminic: Current cake (HSPA+):
Modulation (16QAM, 64QAM)
Number of codes (10, 15)
Multi-carrier
Double, triple… operator infrastructure + terminals evolution
MIMO
2nd leaky feeder study + terminals evolution
Antihistaminic:
Current cake (HSPA+):
21Mbps DL & 5.6 Mbps UL
Latency: < 50 ms

27. LTE (3.9G) OFDMA (DL) & SC-FDMA (UL) Ingredients:
Higher spectrum efficiency
Ingredients:
Huge cake but careful with allergies
Downlink
Uplink
SISO
10 MHz
44.7 Mbps
QPSK
7.2 Mbps
20 MHz
89.7 Mbps
14.4 Mbps
2x2 MIMO
Mbps
16QAM
57.6 Mbps
4x4 MIMO
325 Mbps
64QAM
86.4 Mbps

28. LTE Advanced (4G) Smartphones evolution (real computers) Ingredients:
Carrier aggregation (Up to 100 MHz)
MIMO (8x8 DL, 4x4 UL)
Small cells (128QAM…)
Coordinate transmissions (several cells into one)
3* Michelin cake: Bon appétit!

29. Conclusions Mobile migration: Mobile data evolution:
Challenging project with high visibility
Mobile services improved
CERN monthly bill reduced
SIM card and number changed
Mobile data evolution:
HSPA+ and LTE in the tunnels (no Wi-Fi)
LTE Advanced in LHC experiments (>100Mbps)
LTE/Wi-Fi integration for a technical forum?

30. Why I can’t keep my current number?
We can transfer only active numbers (6,000 of the 10,000 range).
As soon as a number becomes inactive (i.e. someone leaves) the number reverts to Sunrise
CERN should pay 10,000 subscriptions per month to keep all numbers active for the duration of the contract with Swisscom so none will be reverted to Sunrise
In Switzerland, the capacity for moving numbers between operators is 500/day (12 days to move our current active numbers)

31. Transition period What happens in case of delay ?
Sunrise contract ends on the 31st of June.
One month of delay will cost ~100 KCHF
Provided that Sunrise is willing to maintain the service
Why such a short transition period ?
7 months and half is long period to keep the “motivation” of the current operator
During this period any changes are frozen
The new operator needs to start as soon as possible to start generating revenues

32. Sites Outdoor (14 sites): Meyrin (3 sites): Prevessin (2 sites):
Building 60
Water tower
Building 361 (PS)
Prevessin (2 sites):
Building 866
Building 887
SPS (1 site):
BB4
LHC (8 sites)
SD2, 4, 5, 6, 7, 8
SZ33
SDX1

33. Sites Indoor (37 Swisscom sites + 17 CERN sites) LHC: Transfer lines :
9 sites on the surface covering the lifts and caverns
16 CERN sites in the REs covering the tunnel
SCX5
Transfer lines :
1 sites covering TI2 and 1 CERN site covering TI8
SPS (8 sites)
Meyrin:
PS, AD, LINAC3, LINAC 4, N_TOF, CFT3, ISR, DIRAC, ISOLDE
Buildings 358, 2013, 839
Prevessin:
North area, building 911
SM18 (1 site)
Transmission:
Buildings 58, 513, 874

34. Planning Date Work Dec 14 – Feb 15 Site surveys and network design
Dec 14 – Mar 15
Regulators and construction permits
Feb 15 – Jun 15
Network deployment
15th June 2015
Fully operational services
June 2015
SIM cards distribution
1st July 2015
Operator swap