This presentation provides and overview of deploying multipoint microwave to backhaul a small cell network and was presented bu Dr John Naylon, CTO at CBNL, at the Packet Microwave and Backhaul Forum 2012.

1. www.cbnl.com
Deploying multipoint microwave
to backhaul a small cell network
Small Cells in a Big City
Dr John Naylon, Chief Technology Officer,
Cambridge Broadband Networks Limited

2. Topics Covered
• Choosing from the famous
‘backhaul toolbox’
• Observations from a live small
cell deployment using
multipoint microwave
• Conclusions
www.cbnl.com Commercial in confidence 2

3. Backhaul Toolbox
Satellite
Bonded Copper
Multipoint Microwave
Fibre
P-P Microwave
WiFi / Unlicensed
P-P 60GHz
Free-Space Optical (E-Band)
Multipoint NLoS P-P 70/80GHz
www.cbnl.com Commercial in confidence 3

4. Backhaul Toolbox
Satellite
Bonded Copper
Multipoint Microwave
Fibre
P-P Microwave
WiFi / Unlicensed
P-P 60GHz
Free-Space Optical (E-Band)
Multipoint NLoS P-P 70/80GHz
www.cbnl.com Commercial in confidence 4

5. Choosing from the Toolbox
1. The solution has to work
− Not just today, but sustainably as the access network evolves
2. It has to be cost-effective to deploy en masse
www.cbnl.com Commercial in confidence 5

6. The Solution Has To Work: Spectrum Considerations
millimetre wave Unlicensed
18.3GHz Light licensed
Microwave:
16.4GHz for terrestrial Link licenced (PTP)
fixed links Area Licensed (PMP)
Sub 6GHz:
Area Licensed
1.54 GHz for licensed and
Unlicensed
unlicensed fixed & mobile
Source: "Frequency Band Review for Fixed
Wireless Service", for Ofcom, Nov 2011,
http://goo.gl/7S26p
www.cbnl.com Commercial in confidence 6

7. The Solution Has To Work: Spectrum Considerations
Sub 6GHz:
Area Licensed
1.54 GHz for licensed and
Unlicensed
unlicensed fixed & mobile
• Access share of < 6GHz has risen from 1% to 10% in 20
years
• Regulators are seeking to release 500MHz (~10%) more
• Backhaul gets economically squeezed out of < 6GHz
• Unlicensed could be a possibility today … but tomorrow?
www.cbnl.com Commercial in confidence 7

8. The Solution Has To Work: Spectrum Considerations
millimetre wave Unlicensed
18.3GHz Light licensed
Microwave:
16.4GHz for terrestrial Link licenced (PTP)
fixed links Area Licensed (PMP)
• Microwave and millimetre wave offer future-proof capacity
• Tried and tested backhaul technologies for macro network
www.cbnl.com Commercial in confidence 8

9. Backhaul Toolbox
Satellite
Bonded Copper
Multipoint Microwave
Fibre
P-P Microwave
WiFi / Unlicensed
P-P 60GHz
Free-Space Optical (E-Band)
Multipoint NLoS P-P 70/80GHz
www.cbnl.com Commercial in confidence 9

10. Backhaul Toolbox
Satellite
Bonded Copper
Multipoint Microwave
Fibre
P-P Microwave
WiFi / Unlicensed
P-P 60GHz
Free-Space Optical (E-Band)
Multipoint NLoS P-P 70/80GHz
www.cbnl.com Commercial in confidence 10

11. Cost Effective Deployment: What’s New About Small Cells?
Macro cells Small cells
Core
Core
Lots of aggregation in Little aggregation in Many more
the RAN the RAN sites
www.cbnl.com Commercial in confidence 11

12. Cost Effective Deployment: Coping with Many More Sites
Small cells • Three major determinants
of solution cost:
• Frequency
• Topology
Core
• Licensing
www.cbnl.com Commercial in confidence 12

13. Cost Effective Deployment: Cost versus Frequency
Volume Cost: RF Power Amplifier
$160 • RF parts get significantly
$140
$120 more expensive at high
$100
$80
frequencies
$60
$40 • e.g. 71—76GHz PA is 5×
$20
$0 the cost of a 16—33GHz PA
0 20 40 60 80 100
at the same volume
Volume Cost: Low Noise Amplifier
$160 • Low yield, demanding
$140
$120 device geometry, less
$100
$80
volume, awkward packages
$60
$40 • Reflected in equipment
$20
$0 costs!
0 20 40 60 80 100
Frequency (GHz) Sources: Hittite Microwave Corp, Digikey
www.cbnl.com Commercial in confidence 13

14. Cost Effective Deployment: Less is More
Point-to-point Topology • P-P topologies (star, ring,
tree) need 2 ODUs per link
• Multipoint needs a single
sectoral ODU and one
directional ODU per link
• Mean number of links per
Multipoint Topology multipoint sector is 4:
5 ODUs with multipoint
8 ODUs with P-P
• 40% fewer ODUs deployed:
significant cost saving
www.cbnl.com Commercial in confidence 14

15. Cost Effective Deployment: The Licensing Continuum
• Regulator ‘round-trip time’
Link Licensed
and high per-link license
fees mean that:
• Traditional, link-licensed
microwave is too expensive
Cost per Area Licensed
link and too slow for small cells
Light Licensed • Area licensed, light
licensed and unlicensed are
Unlicensed
all workable
• None is completely “free”
Bureaucracy per link due to internal coordination
www.cbnl.com Commercial in confidence 15

16. Cost Effective Deployment: Aggregation
Macro cells Small cells
Core
Core
Lots of aggregation in Little aggregation in Many more
the RAN the RAN sites
www.cbnl.com Commercial in confidence 16

17. Why Does Aggregation Matter?
• Mobile backhaul traffic is already quite bursty, because it is data dominated:
HSPA+ Macro Node B backhaul traffic
Peak: 23.31 Mbps
Mean: 5.54 Mbps
Ratio: 4.20 Mbps
Mbps
www.cbnl.com Commercial in confidence 17

18. Bursty Traffic is Hard to Carry Efficiently
mean channel utilisation 1
• Efficiency = = = 25% average
peak channel capacity peak to mean ratio
HSPA+ Macro Node B backhaul traffic
Peak: 23.31 Mbps
Mean: 5.54 Mbps
Ratio: 4.20 Mbps
Mbps
www.cbnl.com Commercial in confidence 18

19. Looking at Data… 60s Resolution
mean channel utilisation 1
• Efficiency = = = 25% average
peak channel capacity peak to mean ratio
HSPA+ Macro Node B backhaul traffic
Peak: 23.31 Mbps
Mean: 5.54 Mbps
Ratio: 4.20 Mbps
Mbps
www.cbnl.com Commercial in confidence 19

20. Looking at Data… 15m Resolution
mean channel utilisation 1
• Efficiency = = = 28% average
peak channel capacity peak to mean ratio
HSPA+ Macro Node B backhaul traffic
Peak: 20.03 Mbps
Mean: 5.54 Mbps
Ratio: 3.62 Mbps
Mbps
www.cbnl.com Commercial in confidence 20

21. Looking at Data… 1h Resolution
mean channel utilisation 1
• Efficiency = = = 37% average
peak channel capacity peak to mean ratio
HSPA+ Macro Node B backhaul traffic
Peak: 15.04 Mbps
Mean: 5.54 Mbps
Ratio: 2.71Mbps
Mbps
www.cbnl.com Commercial in confidence 21

22. Small Cell Backhaul Traffic
Live small cell network • Much higher peak-to-mean
(as expected)
Peak: 32.67 Mbps
Mean: 1.37 Mbps
Ratio: 23.85 Mbps
• A dedicated (point-to-point)
tail link in this example
would have 4% utilisation
• Does this matter if the
Mbps spectrum is unlicensed?
• Yes: this figure is the
utilisation of the expensive
box at each end as well!
www.cbnl.com Commercial in confidence 22

23. Multipoint Backhaul: Packet Switched not Circuit Switched
Mbps Mbps
• Point-to-point links are statically provisioned circuits
• Packet switching (multipoint) much more efficient for data
• Statistical multiplexing gain increases in small cell networks
www.cbnl.com Commercial in confidence 23

24. Multipoint Backhaul for Small Cells: Less Waste, More Gain
Statistical multiplexing gain
Peak-to-mean ratio of backhaul traffic
• Multipoint efficiency advantage increases as traffic
becomes more bursty (like in a small cell network)
www.cbnl.com Commercial in confidence 24

25. Multipoint Backhaul for Small Cells: Less Waste, More Gain
Statistical multiplexing gain
Nodes per multipoint backhaul sector
• Multipoint efficiency advantage increases as network gets
denser (like in a small cell network)
www.cbnl.com Commercial in confidence 25

26. Current CBNL Small Cell Activities
• Building on years of macro backhaul experience CBNL are deploying
and trialling small cell backhaul with numerous operators and vendors
LTE Picocell
Metro lightRadio
Antennas
WiFi
VectaStar
Backhaul
VectaStar
VectaStar Backhaul
Backhaul
www.cbnl.com Commercial in confidence 26

27. Conclusions
•Small cell backhaul is different: • Good end-user quality of
many more cells to backhaul, non- experience requires much more
traditional locations and even backhaul capacity than there is low
burstier data frequency backhaul spectrum
• Both microwave and millimetre • Multipoint microwave for small cell
wave, P-P and multipoint, can “do tail links offers significant cost
the job” for small cell backhaul savings through higher utilisation of
equipment and spectrum
VectaStar from Cambridge Broadband Networks is the market leader in multipoint microwave
cbnl.com/smallcells 27