“Millimetre-Wave Radios: Challenges and Opportunities Joint ICT KTN and Radio Technology SIG Event 30th January 2014

Andy Sutton

Principal Network Architect

EE Network Strategy

Dr Tim Brown

5GIC/CCSR

University of Surrey

V-Band Radio Systems - Practical Deployment Considerations

Andy Sutton

Principal Network Architect

Network Strategy

30th January 2014

Contents

1. Introduction

2. Use of point to point radio systems

3. Focus on V-band (~60GHz)

4. Deployment scenarios

5. Observations to date

6. Hand over to Tim

7. Questions to both after Tim’s presentation…

Introduction

• Mobile networks are evolving to support the increasing demand for mobile data services

• This evolution requires higher capacity macro cells with multiple RATs, multiple frequency bands (particularly for LTE: 800/1800/2600 etc.), multiple cells sectors and optimisations to maximise link budget and spectral efficiency

• The macro network alone will not manage future demand, small cells as a component of an integrated heterogeneous network (Het-Net) will be essential

• Mobile backhaul must scale in terms of capacity and be optimised in terms of performance to support future Het-Nets and their associated traffic load

• many different types of data (including voice and huge volumes of video)

4

Use of point to point radio systems

5

• EE has over 20 years experience of deploying large volumes of microwave and millimetre wave radio systems to provide mobile backhaul connectivity

• Links have been deployed with capacity ranging from 2Mbps to 1000Mbps

• Frequency bands from 1.4GHz to 42GHz have been used to date

• Trials of radio systems operating in the new V-band and E-band spectrum are on-going in several locations around the UK

• These bands offer new opportunities…

Today’s focus is V-band (~60GHz)

6

Prototype

V-band systems are

maturing with an

increasing number of

live deployments

Some example deployment scenarios

7

s

s s

s

M

s

s s

s

M

s

s s

s

s

4 x radio units = 4 x Ethernet cables

Are there enough ports on the CSG?

What is the link capacity being shared between n x small cells?

What level of statistical

multiplexing gain can be realised at

each junction?

Same questions exist if macro is replaced with small cell backhaul PoP with fixed fibre connectivity

Small cell deployment environment

8

4

3

2

1

Photograph taken in front of lamppost but with short step right to enable view of other lampposts

Post # 2

Post #3

Post #4

Post #1

Connectivity requirements may not be

1 <-> 2, 2 <-> 3, 3 <-> 4 Could be 1 <-> 3 or 1<-> 4…

Small cell deployment environment

9

4

3

2

1

Photograph taken in front of lamppost but with short step right to enable view of other lampposts

Post #3

Post #2

Post #1

Will this clear all vehicles?

Some observations applicable to V-band backhaul radios

• Higher capacity V-band radio systems are required, ideally up to 1Gbps to support the necessary link topologies

• Latency must be very low however this doesn’t appear to be an issue with these point to point links

• Hub or nodal points present some challenges as multiple radio units are required for each direction/hop - compared with multipoint…

• Antenna alignment is a challenge due to narrow beam-width – some vendors have alignment mechanisms which are too coarse, other have very fine alignment mechanisms however some are possibly over engineered, with associated cost implications…

• Overall the technology is very promising for certain deployment scenarios, trials will continue through 2014, possibly some early deployments during H2, still in planning…

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www.surrey.ac.uk/CCSR

V-Band Radio Systems - Practical

Deployment Considerations

5GIC (5G Innovation Centre)

30th Jan 2014

Tim Brown

Lecturer in RF, Antennas and Propagation, University of Surrey

0.01

0.1

1

10

100

10 100

Loss

(d

B/k

m)

Frequency (GHz)

Not a technically ideal solution but licencing issues dictate it has to be done! Historically an unpopular band to use as has high atmospheric absorption and already high loss. Would be nice if it propagated 2-3km away, not just a few hundred metres – highly ambitious.

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What are the challenges in propagating at V-band?

13

Take a look back at the lamp post scenario

4

3

2

1

Photograph taken in front of lamppost but with short step right to enable view of other lampposts

Connectivity requirements may not be

1 <-> 2, 2 <-> 3, 3 <-> 4 Could be 1 <-> 3 or 1<-> 4…

14

Physical Propagation Scenario – What Problems do we have?

Node over or

at side of

lamp post?

Multipath from buildings and high vehicles (e.g. buses)

Antenna

alignment

critical.

Typical Distance < 1km

Within the Fresnel zone is the middle lamp

post, will be subject to diffraction loss.

The lamp posts are protruding a small part of the Fresnel zone, which is contrary to the majority of diffraction models and is not representative of a simple knife edge diffraction

15

Lamp Post Diffraction – Is it problematic?

Measurement carried out at 20m distance, half the typical distance of approximately 40m. Scaled measurement undertaken with smaller sized pole to represent the lamp post. Antennas aligned with pin hole technique Pole moved along the plane and normal to the plane to compare the diffraction loss vs pole position

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Scaled Measured Scenario

Tx Rx

y

x

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Results of Measurements – Does the loss matter?

Tx Rx

y

x

-10

-8

-6

-4

-2

0

2

4

6

8

10

0 1 2 3 4 5 6 7 8 9 10Loss

(dB

)

x Position (m)

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Results of Measurements – Does the loss matter?

Tx Rx

y

x

-10

-8

-6

-4

-2

0

2

4

6

8

10

0 50 100 150 200 250 300 350 400 450 500Loss

(d

B)

y Position (mm)-10

-8

-6

-4

-2

0

2

4

6

8

10

0 50 100 150 200 250 300 350 400 450 500Loss

(d

B)

x Position (mm)

Vertical Polarisation Horizontal Polarisation

Isolated Measurements of Diffraction in the anechoic chamber scaled with smaller pole.

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Scaled Diffraction Measurements – Anechoic Chamber

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Results of Measurements – Does the loss matter?

Tx Rx

y

x

-10

-8

-6

-4

-2

0

2

4

6

8

10

0 20 40 60 80 100 120Loss

(d

B)

y Position (mm)

Horizontal

Vertical

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What’s going on with the phase?

Wall

Wall

In reality there is more than lamp posts to deal with – e.g. decorations, narrow cluttered streets, signs and high vehicles.

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Propagation Scenarios

And what about when the builders come in?

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Propagation Scenarios

Streets do not always use lamp posts…

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Propagation Scenarios

Complex enclosures are very specific.

25

Propagation Scenarios

Mie scattering from rainfall could cause over to 10dB/km loss in extreme weather cases. Limits hold us in terms of the

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Rainfall Effects

0.01

0.1

1

10

100

1 10 100L (d

B/k

m)

Frequency (GHz)

R = 0.25

R = 1.25

R = 5

R = 25

R = 50

R = 100

R = 150

Storms Heavy Rain Drizzle

Precision – Accurate small scale modeling of the propagation phenomena for deployment. Reconfigurability - To conform to changing urban environments and capacity demands. Predictability of variable conditions – including weather, seasons road traffic density.

27

Summary of Challenges in mmWave Backhauls

Thank You Q&A

“Millimetre-Wave Radios: Challenges and Opportunities andy.sutton@ee.co.uk t.brown@surrey.ac.uk

Andy Sutton

Principal Network Architect

EE Network Strategy

Dr Tim Brown

5GIC/CCSR

University of Surrey