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

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

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)

Evolution - Déjà vu! UPS for mobile sites - 2010 SIM cards replacement - 2010 3G in LHC (UMTS900) – 2012 3G in the injector chain – 2013 Mobile network SWAP – 2013 Sunrise network evolution - 2014 LTE pilot in LHCb (L800) - 2014

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

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

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

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

Architecture

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

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

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

Advanced services CERN intranet connection CERN voice VPN CERN PBX interconnection Email2SMS gateways Roaming cost control Automatic billing User provisioning

CERN intranet connection CERN intranet connection (CERN APN): Fixed IP address related to the phone number (16abcd -> 10.14.1ab.1cd) Internet APN by default: Swisscom IP address

CERN voice VPN

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 https://cern.ch/gsm-migration

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 voicemail in July

Mobile data evolution

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

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

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

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

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

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

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

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

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

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!

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?

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)

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

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

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

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