Fronthaul Field Trials and Future Trends

Zakaria TAYQ, Philippe CHANCLOU, Luiz ANET NETO

Orange Labs Networks – Lannion – France

zakaria.tayq@orange.com

EuCNC 2016, Workshop W04b

27th June, Athens, GREECE

2

Contents

1. Fronthaul trials drivers

2. Optical fronthaul trials

3. Wireless fronthaul trials

4. C-RAN future trends

5. Conclusion

3

Build new sites which are identified by operational teams, as

problematic in the regular process (Distributed RAN with backhaul)

Identify OPEX and CAPEX savings compared to existing Radio Access

architecture

Initialize the learning curve of fronthaul production: technologic

choice, vendors pre-selection, installation process, integration in the

Operation Support System

Measurements of Energy consumption

Measurements, in a second step, of Data traffic impact (CoMP release)

Fronthaul trials drivers

Drivers = co-construction with operational teams

4

RRH

IP/MPLS

network

S1

Central Office

BBU

Syste

m

module

BBU

Syste

m

module

BBU

Syste

m

module

Backhaul

Digital-RoF

Fronthaul : CPRI

Fronthaul interfaces: CPRI, OBSAI, ORI

Fronthaul medium: - Optical Fiber : Single Mode Fiber with or without color flavors

- Wireless : several RF bands possible with or without spectral efficiency

RRH

RRH

RRH

Wireless

Optical Fiber

BBU: BaseBand Unit or

RRH: Remote Radio Head

UE: User Equipment

UE

RRH RRH

Fronthaul: a new segment that comes

with Cloud Radio Access Network

5

Contents

1.Fronthaul trials drivers

2.Optical fronthaul trials

3.Wireless fronthaul trials

4.C-RAN future trends

5. Conclusion

6

Optical fronthaul (CPRI) 1/3

Passive Active & Semi Active

Fiber-rich

network

to

shared

fiber

7

Optical fronthaul (CPRI) 2/3 : coming technologies

Passive Active & Semi Active

-At antenna site:

Remote diagnostic function inside SFP

No active equipement

-At BBU hotel:

KPI per channel

visibility on optical layer performance

x3 more channels and still a passive

solution compatible for outdoor operation

and single fiber working

Re-used existing CWDM infrastructure

with plug&play new wavelength

multiplexers

8

Optical fronthaul (CPRI) 3/3

Passive Active & Semi Active

Fiber-rich

network

to

shared

fiber

Solution selected

for trials

9

What is a passive optical fronthaul solution?

RRH RRH RRH

FTTA & PTTA

hybrid cable

Low foot print

cabinet Energy and passive fiber

Passive CWDM

MUX & DeMUX

Passive CWDM

MUX & DeMUX BBU 4G

interface fronthaul

BBU 3G

interface backhaul

BBU hotel

BBU Hotel

Data center area

for a cells cluster

optical fiber

Backhaul

Hardware sharing

BBU 2G

10

Contents

1.Fronthaul trials drivers

2.Optical fronthaul trials

3.Wireless fronthaul trials

4.C-RAN future trends

5. Conclusion

11

Wireless fronthaul (CPRI)

Native wireless with spectral efficiency

With wireless fronthaul, it is possible to turn existing macro site into local C-RAN

Easy and fast deployment when it is hard do use fiber

From

Small cell

or 4th sector

to

Macro cell

12

Wireless fronthaul (CPRI)

Native wireless with spectral efficiency

From

Small cell

or 4th sector

to

Macro cell

Solution selected

for trials

(Mature solutions)

13

Wireless fronthaul: on Orange France network

BBU WFM WFM RRH

RRHDigital Interfaces

An

ten

na

An

ten

na

RF Interface

FrontLink™ 58 Product

RRH

An

ten

na

Wireless fronthaul on Orange commercial network with FrontLink™ solution from

Three sectors LTE 2600 MIMO 2x2 → 3x2.457Gbit/s CPRI on a wireless fronthaul link

→ In less than 70 MHz bandwidth

Fiber-based Fronthaul Wireless Fronthaul

14

Contents

1.Fronthaul trials drivers

2.Optical fronthaul trials

3.Wireless fronthaul trials

4.C-RAN future trends

5. Conclusion

15

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.

Different new functional splits are possible

The Radio Access Network architecture : the coming « 5G »

L2

L1

F

F

T

ressource

mapping

Q

A

M

F

E

C

R

L

C

M

A

C

P

D

C

P

L3

S

1

R

R

C

X

2

O

A

M

CPRI

OBSAI

CPU & real time constants

Fronthaul bandwidth

Service PDCP

RLC

RLC

MAC

MAC MAC

PHY

Low High

Split

PHY

CPRI

OBSAI

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

RF

BBU L3 & L2… …L2 & L1 RRH BBU & RRH partitioning

vBBU

16

vBBU L3&L2

Master

central

office

(Data center)

Load balancer

& switch Cell site

aggregator

L1&L2

The virtualization is explicitly assumed to be part of the 5G architecture

The low part of the BBU (L1 and potentially a part of L2) cannot be virtualized due

to CPU and real time constraints, it will be implemented in a cell site aggregator

The high part (L3 and a part of L2) will be virtualized and implemented in the vBBU

It is possible to have intra-site CoMP

The Radio Access Network architecture : the coming « 5G »

Antenna

Radio unit

Ring

Aggregation

Network

Ethernet / Fiber

Access

Network

17

vBBU L3&L2

Master

central

office

(Data center)

Inter site CoMP can be obtained if L1&L2 are moved higher in the network:

→ Pool of cell site aggregators

CPRI is used between the antenna site and the Pool of cell site aggregators

The Radio Access Network architecture : the coming « 5G »

Antenna

Radio unit

Ring

Aggregation

Network

Ethernet / Fiber

CPRIs over Fiber

Pool of cell

site aggregators

L1&L2

Access

Network

4 keys points

1 CPRI fronthaul experimentations in France in opportunist mode

3 Wireless fronthaul is used when fiber is hard to deploy

Conclusion

2 Fronthaul trials are mainly based on optical fiber

4 New functional split with RAN virtualization expected for 5G

Thank you

Merci

Gràcies

Danke

Grazie

Tack

谢谢

감사합니다

ありがとうございました

Acknowledgements: