Examining the Fronthaul Network Segment on the 5G Road Why Hybrid Optical WDM Access and Wireless Technologies are required? Philippe Chanclou, Sebastien Randazzo, 18th Annual Next Generation Optical Networking Congress 29th June – 1st July 2016 Day Three, Friday 1st July Nice Acropolis France

The Radio Access Network architecture : state of art The current mobile architecture with distributed RAN equipment. Backhaul aggregation Standard BS Antenna Radio unit CPRI Base band units Backhaul cell site Ethernet / Fiber Central office Backhaul access

Optical Ethernet backhaul The backhaul cell site is an aggregator of BBUs for data traffic based on 1Gbit/s Ethernet interface with synchronization (SyncE, IEEE 1588). European benchmark of Ethernet leased line: Incumbent reference Offer Ethernet leased line charges for a local access – 5km – 24 months source: November 2014, Wik-consult repport Considering the market for the provision of ‘high quality’ services for business use (Mobile), this benchmark analysis describes the availability, standard prices for Ethernet leased lines supplied by former incumbent operators in the EU. A wide variation in charges can be seen especially at speeds of 100M and above, which are typically provided via a fibre connection.

The Radio Access Network architecture : state of art « Cloud RAN » The current mobile architecture with centralized RAN equipment: Phase1 : BBU centralisation (BBU-RU link based on CPRI/OBSAI) Phase 2 : BBU pooling Optimal architecture for CoMP RAN features (intra and inter-cell sites). Down sizing the form factor of equipement at the cell site Backhaul aggregation Antenna BBU Remoted BBU Centralised Radio unit Base band units CPRI/OBSAI over Fiber Central office Fronthaul access

The Radio Access Network architecture : state of art « Cloud RAN » Reach between cell sites and Central office: For urban area (high &middle density) : 75% links have length < 4km 95% links have length < 8km 99% links have length < 20km The existing network infrastructure is “compatible” with the fronthaul timing limitation (RTT < 150µs) Backhaul aggregation Cell site to Central office reach km Hits Central office Fronthaul access

Optical fronthaul (CPRI, OBSAI, ORI) Passive Active & Semi Active Fiber-rich network to shared fiber

Wireless fronthaul (CPRI, OBSAI, ORI) Native wireless with spectral efficiency From Small cell or 4th sector to Macro cell With wireless fronthaul, turn existing macro site into local C-RAN Easier and faster deployment, same network architecture than short reach fiber network

Radio evolutions from 4G Adv to 5G+ 100Gbps The ultimate 5G 25Gbps Mm Waves High bandwidth Full Massive MIMO 5G+ Expected peak cell site throughput 2Gbps 700MHz (wide range of coverage) 3.5GHz with Massive MIMO Ultra Low latency First 5G 1Gbps More Carrier Aggregation 256 QAM MIMO 4*4 300Mbps 4G Adv Time

The Radio Access Network architecture : the coming « 5G » The target step of RAN architecture is the virtual RAN where a reconfigurable hardware is used. This architecture facilitates the dynamic adaptation of processing resources to the traffic request of available Radio Access Technology. Open functional splits with L2 or L1interfaces BBU & RRH partitioning BBU L3 & L2… …L2 & L1 RRH CPU & real time constants vBBU L3 L2 L1 RF CPRI OBSAI PDCP RLC MAC FEC QAM FFT ressource mapping OAM X2 S1 RRC Service PDCP RLC RLC MAC MAC MAC PHY Split PHY CPRI OBSAI Fronthaul bandwidth Low High CoMP capability DPS, CS, CB, … … JT/JR CoMP: Coordinated Multi-Point DPS: Dynamic Point Selection CS: Coordinated Scheduling CB: Coordinated Beamforming JT: Joint Transmission JR: Joint Reception

The Radio Access Network architecture : the coming « 5G » The low part of the BBU (L1 and potentially a part of L2) cannot be virtualized due to CPU and real time constraints The high part can be virtualized (L3 and a part of L2) The virtualization is explicitly assumed to be part of the 5G architecture and design principles vRAN is a prerequisite of the network slicing vBBU L3&L2 Antenna Load balancer & switch Radio unit Cell site aggregator L1&L2 Ring Aggregation Network Master central office (Data center) Ethernet / Fiber Access Network

The Radio Access Network architecture : the coming « 5G » L2 & L3 virtualisation The optimal architecture for CoMP inter cell sites should request: L1 & L2 Centralisation Pool of cell site aggregators : still CPRI/OBSAI network segments vBBU L3&L2 Antenna Ethernet / Fiber Pool of cell site aggregators L1&L2 Radio unit Ring Aggregation Network Master central office (Data center) CPRIs over Fiber Access Network

The Radio Access Network architecture : the coming « 5G » Backhaul & Fronthaul architecture evolution: Aggregation Network Access Network Cell site 3 sectors 20 MHz – MIMO4x4 BBU Ethernet Backhaul 300 Mbit/s (1GEth) Additional data rate vs. backhaul dimensioning: minimum +20% maximum x3 BBU pool CPRI : 3 x 5Gbit/s (3 ) ≈ 100µs / 20 km vBBU Ethernet New Functional Split 360 Mbit/s < ? < 900 Mbit/s Cell site gateway ≈ 2ms / 400 km

Mobile Backhaul and Fronthaul line rate CPRI/OBSAI rate per RRH Eth. cell site gateway (new functional split) Gbit/s Compressed CPRI rate per RRH 100 25 Eth. Backhaul per BBU pool 10 Transmission line rate 5 2 1 Eth. Backhaul per cell site 0.1 2G Radio Access Technologies 3G 4G to 4G++ 5G to 5G+

Mobile backhaul and fronthaul optical technologies for last miles Aggregation Network Access Network (last mile network segment) Cell site BBU BBU pool vBBU Cell site gateway

Mobile backhaul and fronthaul optical technologies for last miles Aggregation Network Access Network (last mile network segment) Cell site Ethernet backhaul PtP switch (1G10G 40G 100G) PtP router G/XGS-PON (synergy with FTTH roll out) BBU Switch FTTH ONT BBU pool vBBU Cell site gateway

Mobile backhaul and fronthaul optical technologies for last miles Aggregation Network Access Network (last mile network segment) Cell site BBU BBU pool CPRI/OBSAI/ORI fronthaul Transceivers Mux/DeMUX  WDM technology : CWDM, DWDM, PtP WDM Potential synergy with FTTH roll out (supernumenary fiber, sharing infrastructure with wavelength overlay) vBBU Cell site gateway

Mobile backhaul and fronthaul optical technologies for last miles Aggregation Network Access Network (last mile network segment) Cell site BBU BBU pool Transceivers New backhaul for new functional split vBBU PtP router (1G40G 100G) XGS-PON, NG-PON2 TWDM or PtP WDM (synergy with FTTH roll out) Switch FTTH ONT Cell site gateway

Optical access trends for Mobile application Last-mile mobile backhaul context-synthesis: Mobile backhaul is done by DSL or fiber PtP with Switch/Router. Fiber will the enabler medium of backhauling Mobile backhaul is already supported by G-PON (with synchronisation feature) Tomorrow, more antenna sites & more data rate (5G) require: synergy with FTTx roll out new PON generation : XGS-PON, NG-PON2 (TWDM & WDM-PON) FTTH context-synthesis: What G-PON offers in term of bit rate, is enough for the backhaul 2G/3G/4G. XGS-PON will be soon available to support 5G WDM in access is in progress by NG-PON2 to support PtP WDM or TWDM (100G) Data rate capacity of FTTx - PON system (Down-/Up-stream) Timeline 2006 2010 2015 2,5/1,25 Gbit/s XGS-PON XG-PON 1 G-PON 10/2,5 Gbit/s 10/10 Gbit/s the potential 25G-PON 25/10 Gbit/s 25/25 Gbit/s 40/10 Gbit/s 80/80 Gbit/s TWDM-PON & PtP WDM PON grey optics WDM optics ITU-T G.984 ITU-T G.987 ITU-T G.9807 ITU-T G.989 2018 – 2020 ? 100G-PON 100 Gbit/s presentation title 18

Optical access trends for Mobile application presentation title 19

1 2 3 4 4 keys points Conclusion CPRI fronthaul experimentations in France in opportunist mode Fibber has the preferred medium of “X”-hauling 3 4 New functional split based on Ethernet is coming for 5G Heterogeneous last-mile: -PtP Ethernet (switch/router), -PON for FTTx synergy, -WDM for efficient sharing presentation title

Thank You. Acknowledgment: