Sharing experiences from small cell backhaul trials. Andy Sutton Principal Network Architect Network Strategy, Architecture & Design 31/01/13

Transcription

1 Sharing experiences from small cell backhaul trials Andy Sutton Principal Network Architect Network Strategy, Architecture & Design 31/01/13

2 Contents 1. Overview of EE 2G/3G/4G/WiFi Network 2. Understanding the Proposed Small Cell Use Cases in EE 3. Small Cell backhaul architecture 4. Review Fixed Backhaul Trials on Third Party Next Generation Access, Refers to FTTC/VDSL2 and FTTP 5. Discuss Results From Wireless Small Cell Backhaul Trials 6. Real World deployment environment 7. Summary Cambridge Wireless Small Cell SIG event, Let s Get Real!

3 EE 2G/3G/4G macro layer network architecture Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 3

4 What do we mean by small cells? Small cells could be interpreted as anything non-macrocell In our current strategy, we use this term to mean: Outdoor low power cells within urban clutter In traditional terminology, this could be regarded as a true microcell. Others refer to as Outdoor Femtocell Output powers in the range W Indoor picocells and femtocells are considered separately WiFi deployments are considered separately Timing of requirement suggests ~G technology, but evolution path to LTE Small cells have dedicated operator deployed backhaul Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 4

5 Small cell backhaul capacity requirements 3G use case: Voice and data or just data? - consider likely coverage enhancements from capacity cells HSPA, HSPA+, 21Mbps, 42Mbps Spectral efficiency, use of MIMO? Low 10s of Mbps LTE use case: Voice and data or just data? - consider likely coverage enhancements from capacity cells Channel bandwidth, 10MHz, 20MHz Spectral efficiency, use of extended MIMO schemes? High 10s of Mbps, 100Mbps+ in certain scenarios Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 5

6 QoS and performance requirements A small cell layer under a macro-cell will enhance capacity however it should be transparent to the end user Therefore key performance indicators should ideally be the same as the macro network Throughput, although this may be even higher on a small cell Latency, a challenge for the backhaul solution however it is achievable, less of an issue with 3G Availability, an interesting one, needs to be available when required from a capacity perspective Synchronisation, frequency alignment with macro and other small cells, seamless mobility between layers Phase comes into play if TDD or with specific features eg. CoMP Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 6

7 Small cell backhaul options applicable to EE Small Cell Backhaul Competitive Operator Incumbent operator Fixed Wireless Lease or build (product vs technology) Copper Fibre Wireless xdsl xpon Point-Point Next slide Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 7

8 Wireless small cell backhaul options Wireless NLoS TDD or FDD LoS TDD or FDD Traditional bands (10-42GHz) V-Band <6GHz spectrum Licensed or unlicensed Pt -Mpt or mesh >6GHz spectrum Licensed or unlicensed Pt-Pt or Pt/Mpt-Mpt E-Band 90GHz+ Pt/Mpt-Mpt 28/32/42GHz Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 8

9 Small cell backhaul architecture two options Backhaul could be fully integrated with the macro network or completely decoupled with an overlay (underlay) solution Integrated solution requires high-capacity macro layer backhaul however opens up future opportunities for coupling between layers Dedicated backhaul decouples the traffic load between macro and small cell backhaul solutions may limit future options for co-ordination Requirements will change as we evolve from 3G to LTE small cells Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 9

10 Small cell backhaul architectures - integrated or decoupled Macro backhaul not illustrated for clarity Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 10

11 Small cell backhaul architectures - integrated or decoupled or a hybrid of the two Macro backhaul not illustrated for clarity Macro backhaul not illustrated for clarity Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 11

12 Fixed PoPs for small cell backhaul - macro site or dedicated PoP Integrated architecture Multi-RAT macro sites have high capacity backhaul, scalable to 1Gbps and beyond point to point fibre and microwave are both valid technologies In many cases the macro backhaul could easily accommodate a number of small cells Dedicated architecture Dedicated small cells fixed PoP must scale appropriately 3G requirements can be met by VDSL2/FTTC or GPON/FTTP LTE requirements are likely to require GPON/FTTP Challenges: Suitable CPE Sync support QoS Opportunity to use these NGA technologies will increase geographic reach whilst reducing costs point to point fibre is valid if the cost point works Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 12

13 Wireless small cell backhaul EE thanks the following vendors for supporting practical radio technology trials Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 13

14 Wireless small cell backhaul trials Initial evaluation of technologies during 2011 selected the following options: Sub 6GHz n/nlos 60GHz V-band 70/80GHz E-band Trials organisation cross functional team Desktop study Vendor selection for technology trial (no agreement to purchase products) Demos and bench testing Installations on EE sites in Bristol, UK (spectrum licensing as appropriate) Evaluations, load testing, performance mapped against weather etc Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 14

15 Sub 6GHz n/nlos - Blinq Networks Full NLoS planned Trial deployed in the 3.5GHz band Extensive testing in Canada Field trial on-going in UK Reference link with LoS nlos link running 12 to 13dB lower RSSI than reference link bit still at the highest modulation 10MHz channel 256QAM 6/8 60Mbps throughput 50/50 go/return 65/35 planned Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 15

16 60GHz V-band NEC Extensive testing in NEC UK Labs Field trial on-going in UK License free spectrum 16 QAM (64QAM on roadmap) 56MHz channel (adjusted to 50MHz in near future) 183Mbps throughput Holding up better than expected in the presence of rainfall Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 16

17 70/80GHz E-band Bridgewave Extensive testing in EE UK Labs Field trial on-going in UK Lightly licensed spectrum 1Gbps throughput 2 links, one reference and one running parallel to wall to simulate street canyon -7dB from ref link Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 17

18 Conclusions to date Point to point fibre is perfect however not available everywhere at the correct price point Next Generation Access FTTC with VDSL2 can support 3G small cells however sync and QoS issues to be resolved + suitable CPE required to address all deployment scenarios GPON appears viable however testing of FTTP/GPON is scheduled during 2013 Near and Non line of sight radio systems have a role to play however we need alignment on spectrum band(s) to enable mass market solutions need to scale to support higher throughput 60GHz works well, we need to better understand the antenna alignment procedures and co-existence with other systems in dense urban environment 70/80GHz offer very high capacity however these radios are quite expensive at the moment, when compared with 6{GHz. Some price disruption started Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 18

19 Next steps Conclude testing VDSL2/FTTC solutions Conclude testing the three wireless technologies Introduce new trials based on more recent market analysis Point to multi-point and multi-point to multi-point (mesh) systems Based on technical evaluations, issue RFP(s) as appropriate Initiate trials with FTTP/GPON solutions Develop business case for all technologies (includes pt-pt fibre) Conduct live field trials with real small cells connected to selected backhaul solutions Model the architectures and apply network evolution scenarios Work with strategic partners to fully develop the small cell eco-system Work with regulators to ensure access to suitable spectrum Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 19

20 Let s go for a walk Small cell site survey in Birmingham, UK Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 20

21 Birmingham City centre LoS survey to macro sites Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 21

22 Birmingham City Centre (1) Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 22

23 Birmingham City Centre (2) Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 23

24 Birmingham City Centre (3) Many hotels in this area identified as hotspot suggests in-building usage Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 24

25 Birmingham City Centre (4) In some areas the street lighting is installed on buildings, no lampposts Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 25

26 Summary Small cells are part of an operators solutions tool kit to address several network optimisation challenges, mainly capacity and/or coverage related Small cells must have a very low TCO, we re targeting 10% of the TCO of a macro in the same area, 10% is target in a maturing eco-system Small cell backhaul solutions are potentially a huge market however there are too many solutions for all to succeed, we need to find best of breed whilst maintaining the flexibility of the backhaul toolkit Fixed and wireless solutions need to be deployed together in an optimised architecture Consider network evolution to LTE and LTE-A when selecting small cell backhaul architecture Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 26

27 THANK YOU Cambridge Wireless Small Cell SIG event, Let s Get Real! }{ ~ 27