2016 Tyrrhenian International Workshop on Digital ...tyrr2016.cnit.it/tyrr-content/uploads/Open-C-RAN-Lab-Testbed_Olive... · 2016 Tyrrhenian International Workshop on Digital Communications

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Arnaldo S. R. Oliveira

FLEXICELL - Open C-RAN Lab

Testbed

2016 Tyrrhenian International Workshop on Digital Communications

Livorno, Italy - September 11-14, 2016

2

Summary

• FLEXICELL (IT-Aveiro flexible and open C-RAN

LTE lab demonstrator/testbed based on

OpenAirInterface)

• Complete C-RAN LTE compliant base station for

experimentation and evaluation of next generation

wireless communication systems

• Outline of this talk

• Motivation

• Architecture

• Implementation

• Demonstration video

• Concluding remarks


| Livorno, Italy - September 11-14, 2016

3

5G Communication Scenarios



Emergency communication

Large-scale events Aeronautical

communication

M2M communication

New train guidance

4K/8Kdigital signage

Multi-angle real-time

communication

B2Bcommunication

Remote control

Network appliances

High-speed railway communication Automatic

operation

Car telematics

High bandwidth IoT/M2M Low latency

4

Cloud Radio Access Networks



Source: White Paper - “Fronthaul & Cloud RAN Evolutions” (Orange, PT, NTT, Swisscom)

Node density

Number of cells

Bandwidth and throughput

Power efficiency

Latency

Cell size

CAPEX and OPEX

5

Cloud Radio Access Networks

• Remote Radio Heads (RRHs) / Remote Antenna Units (RAUs)

transparently connected to a Base Band Unit (BBU) or Central Unit (CU)

• Processing functionalities transferred to the BBU

• Co-located processing of the radio signals from multiple antenna sites

• Facilitate the implementation of cooperation techniques

• Ease vertical handover



• Reliable, simple, transparent and

inexpensive (optical) networks

are required to interconnect the

RRHs with the BBU

6

Base OpenAirInterface FLEXICELL C-RAN Platform



COTS UEsOAI Soft EPC OAI Soft eNB

Internet

App Server

SGi

S11

HSSMME

S1-C

GPP

ExpressMIMO2S+PDN-GW

OAI Soft EPC OAI/FLEXICELL C-RAN Soft eNB

COTS UEs

S11

HSSMME

S1-C

GPP XilinxKC705/VC707

S+PDN-GW

FLEXICELL CPE/RRH

Xilinx KC705

7

CPRI 20 km optical fiber

Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem

Centralized Base Band Unit (BBU)

Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.

Remote Radio Head (RRH)

S1

UE #2

FLEXICELL C-RAN Testbed Architecture @ IT-Aveiro

• Cloud RAN compliant

• 20 km fronthaul

• CPRI-based transport

• Digital radio compression

• Multi-band Software Defined Radio front-end (RRH)

• OAI eNodeB and EPC (LTE)

• Interoperability with commercial UEs



8

Base Band Unit



DDR

Data Interconnect

Embedded Processor

(MicroBlaze)DMA Controllers

Control Interconnect

PCIe Gen2Interface

Compression

E-UTRA

Ethernet MAC

Decompression

CPRICore

UART

Local Memory

OAI SoftmodemComputer

(standard x64 PC

running OAI softmodem

with IT device drivers)

SFP+ Fronthaul

External(master)

ClockReference

Debug Manager

Interrupt Controller

CPRI Clock DomainPCIe Clock Domain Xilinx VC707/KC705 Dev Kit

CPRIReference

Clock


Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem


Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.


S1

UE #2

9

Remote Radio Head



RF Frontend Data

Interface

Embedded Processor

(MicroBlaze)

Control Interconnect

FMC

Compression

E-UTRA

Ethernet MAC

Decompression

CPRICore

UART

Local Memory

ADFMCOMMS3

(AD9361)+

Analog RFFrontend

SFP+Fronthaul

Debug Manager

Interrupt Controller

RF FrontendControl Interface

Clock Recovery

CPRI Clock Domain Frontend Clock DomainXilinx KC705 Dev Kit


Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem


Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.


S1

UE #2

10

AFE

Xilinx KC705 Evaluation Board

FPGA Kintex-7

CompressionSFP

AD9361Digital

Interface

ADFMCOMMS3 with AD9361 RF

Transceiver

PA

LNA

PLLs

Low Jitter PLLRecovered Clock External Clock Reference

ADCADC

DACDAC

Embedded Controller

Decompression

CPRIInterface

FronthaulInterface

Remote Radio Head




Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem


Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.


S1

UE #2

Tx/Rx 1

Driver

ADFMCOMMS3

AD9361

ADL5606

Bands 1, 3

Band 7

SP5T

SP5T

LNA

LNA

LNA

Bands 8, 20

Bands 1, 3

Band 7

Switch and PA ON/OFF Control (FPGA GPIOs)

ADL5523

ADL5523

ADL5523

AP561-F

AP561-F

AP561-FADL5606

ADL5605

SP3T SP5TSP3T

SKY13415-485LF

DuplexersTDK-B8633 (Band 20)ACMD-7606 (Band 8)ACMD-6103 (Band 3)ACMD-7614(?) (Band 1)

ACMD-6007(Band 7)SKY13392-359LF

SKY13415-485LF

SP3T

Bands 8, 20

PA

Driver PA

PA

Power Monitoring Circuit

SP5T

ADC

ADCInternal

LNA

DAC

DAC

12b c2 I1

12b c2 Q1

70MHz … 6GHz Tx LO 0⁰ 90⁰

70MHz … 6GHz Rx LO 90⁰

0⁰

12b c2 I2

12b c2 Q2

SPI Slave

Control RegistersF

MC

Co

nn

ect

or

– F

PG

A I

nte

rfa

ce

BBPLL

RFPLL

Attenuation AP561-F

AP561-F

PA

PA

SKY13415-485LF

Driver

π3dB

π3dB• Bands: 1 (2100MHz), 3 (1800MHz), 7

(2600MHz), 8 (900MHz), 20 (800MHz)

• Modes: SISO 1x1 and MIMO 2x2

• Output power up to 20 dBm

11

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10

1000

2000

3000

4000

5000

6000

Fronthaul Interface with Digital Radio Compression

• High-bandwidth CPRI-based optical fronthaul

supporting line rates up to 10 Gbps

• Compression of the digital radio samples (to save

fronthaul bandwidth)

• Non-linear quantization technique based on m-law

• Accounts for the statistical distribution of LTE

waveforms

• Matched Compression and Decompression blocks for

Downlink and Uplink

• Simple encoding and decoding tables (LUTs) 50% line rate savings with negligible EVM degradation



No Compression Non-Linear

Quantization

Compression

LTE Uplink Signal SC-FDMA 20MHz 4UE

Resolution (bits) 12 7

Rx Power (dBm) -30 -30

EVM (%) 0.92 1.19

LTE Downlink - OFDM

LTE Uplink – SC-FDMA

BBU

Downlink IQ Compression

Uplink IQ De-Compression

CPRIInterface

RRH

Uplink IQ Compression

Downlink IQ De-Compression

CPRIInterface

BasebandProcessing

Radio Front-EndFronthaul

Original

I/Q

n bits

I/Q codeword

n bits

I/Q

non-linear

decoded

n bits

EncoderLUT

DecoderLUT

. . .

. . .

a0

an-1

b0b1

bn-1

. . .

c0c1

cn-1

. . .


Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem


Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.


S1

UE #2

12

User Equipments/Terminals

• Interoperability with COTS UEs

• Custom SIM cards provisioning

• Smartphone (Samsung GT-I9295)

• Huawei 4G modem (E398)

• Utilization scenarios

• General data traffic (browsing, streaming, VoIP and video Skype call



Core Network

• OAI EPC running on

• Xeon-based virtual machine (6 vCPU; RAM 10Gb; Disk 250GB)


Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem


Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.


S1

UE #2

13

SIM cards information

• Algorithm: Milenage

• Ki: 00112233445566778899aabbccddeeff

• OP: 01020304050607080910111213141516

• OPc: 0ed47545168eafe2c39c075829a7b61f

• SPN: OpenAirInterface MCC: 268 (PT) MNC: 08 (new MNO/MNC)

• IMSI: 268080000000001 (MCC|MNC|id),

• SQN: 000000000001



SIM card configuration and provisioning

• USIM cards

• SMAOT100NFC - 4G/LTE UICC Open Card

• Card reader/programmer and software

• Gemalto IDBridge K30 USB token

• Card Admin tool


Fronthaul

UE #1

LTE Network Core

OAI EPCMobile

BackhaulInternet

Fronthaul Interface

RadioCompress.

OAI Soft Modem


Multi-bandRF

Frontend

Fronthaul Interface

RadioCompress.


S1

UE #2

14

Deployment Scenario – PON supported Fronthaul



Residential(2Play and 3Play services)

Local Community (Schools, Police Stations,…)

OLT NG-PON2

Tx, Rx

1, 5

OLT XG-PON

2, 6

3, 7

4, 8

Business and Enterprise (VPN L3, Access to the internet)

NG-PON2 ONU

GPON ONU

WM

OTDR

Copper Last Mile (MSAN and DSLAM aggregation)

Mobile BackhaulCommon Public Radio Interface (CPRI)

NG-PON2 ONU

GPON ONU

OAI Virtualized BBU

CPRI 1

CPRI n

Common Public Radio Interface (CPRI)

CO / OLT

Splitter

ODN / Fronthaul CPE / RRH

DL/UL

CPRI Compression & Port Expansion

MU

X

MU

X

Flexicell CPE / RRH n

Mobile Devices

BasebandProcessing

IP/M

PLS

bac

khau

lO

AI E

PC

/LT

E

RF Video HE

OLT GPON

CEx

CoexistenceElement

Flexicell CPE / RRH 1

PON is a distributed network with inherently centralized control

15

Demonstration

Video



16

Concluding Remarks

• OAI-based flexible C-RAN LTE lab demonstrator

• To the best of our knowledge it is the first, open and fully

operational C-RAN compliant implementation

• Exceeding 20 km tested fronthaul

• BBU and RRH digital components implemented on COTS FPGA

kits (Xilinx VC707 and KC705)

• Custom design of the RRH RF multi-band front-end

• Interoperability with commercial UEs

• Convenient testbed to evaluate

• Digital radio compression algorithms to save fronthaul bandwidth

• Latency vs. fronthaul length

• Throughput requirements

• New fronthaul protocols and interfaces

• Next generation waveforms



17

Thank you very much for your attention



[email protected]

Project team members: Arnaldo Oliveira, Jorge Santos, Paulo Monteiro, Nuno Carvalho + Altice Labs engineers

Documents

2016 Tyrrhenian International Workshop on Digital ...tyrr2016.cnit.it/tyrr-content/uploads/Open-C-RAN-Lab-Testbed_Olive... · 2016 Tyrrhenian International Workshop on Digital Communications